Dissertations and Master's Theses (Campus Access)

The important of cognitive adaptability for communicative performance across cooperative interactions

Matthew H Roy — Wed, 22 May 2013 16:08:59 PDT

The concept of cognitive flexibility between the phenomenal self and the outside world, between conceptual realms, and between conscious and unconscious has long been identified in psychoanalytic literature. Recently, researchers in the field of communication have identified trust, anxiety, self-disclosure, and satisfaction as important variables which affect evaluations of communication competence. This study attempted to bring these seemingly unrelated streams of literature together through a third stream of literature--cooperative work environments. Recently, theoreticians and business practitioners alike have heightened their attention to such cooperative arrangements as collaboration, joint ventures, self-managed work teams, and virtual organizations. These relatively new organizational forms greatly depend on the clear communication of co-workers. This research involved the investigation of the relationship between individual flexibility, social interaction, task contexts, and communication competence with the hope of providing a clear picture of evaluations of communication competence in cooperative arrangements.^ Gudykunst's (1993) communication competence construct was used as a guiding framework. The general hypotheses that there is a relationship between cognitive flexibility, task contexts, and communication competence was tested using a multivariate analysis of variance. The results support the general hypotheses that both individual/group flexibility, and task environment significantly affect evaluations of communication competence and related variables. More specifically, significant differences were found with respect to the dependent variables of communication competence, trust, and satisfaction when respondents were interacting in a collaborative versus integrative context.^ The second part of this research involved an exploratory look at the cognitive schema individuals use when evaluating the competence of communicative behaviors. A Q-sort procedure was performed by 78 participants. Factor analysis resulted in the emergence of several distinct factors (groups of people). General conclusions drawn from these findings include: (1) communication competence is a complex phenomenon involving the utilization of multiple criteria in its evaluation; and (2) males and females differ on the criteria used to judge competent communication with females focusing more on the expressiveness/disclosiveness and males more on the assertiveness/aggressiveness of the communicator.^ Conclusions and directions for future research are discussed in light of the findings. ^

Individual resiliency and vulnerability in the Providence Longitudinal Study: A study of social competence and antisocial behavior

Lisa Creane Hayden — Wed, 22 May 2013 16:08:56 PDT

The Providence Longitudinal Study (PLS) was used to replicate findings of Werner & Smith (1989) of high-risk but resilient young adults within a normative birth cohort from Kauai, Hawaii. With a similarly sized population (n = 693) studied from birth to age 7 in the National Collaborative Perinatal Project (NCPP) but within different culture and decade and with different measures, replications results from the PLS were mixed. The overall pattern of interactions between risk factors, life and family stressors and social competence heightened the predictability of logistic regression models, but the most crucial variables to predicting antisocial behavior in this study were gender and school failure. Implications for early intervention and prevention are discussed. ^

Chr\'etien de Troyes' Perceval: Androgynous development of the hero

Michele F Cooper — Wed, 22 May 2013 16:08:54 PDT

Perceval is analyzed in connection with his chivalric and spiritual biography as he develops into an androgynous adult with the masculine and feminine aspects of his psyche in better balance than they are at the outset when he rejects the feminine for a militant and aggressive form of chivalry. This inner development is paralleled by Chretien's narration and writing techniques such as conjointure and entrelacement, which encompass multiple thematic and character polarities, contrasts, doubling, and parallels. Perceval must learn, like all his counterparts in medieval romance, that traditional chivalric practice with its emphasis on physical prowess, vanity, and marital reputation produces neither a good knight nor a successful life. The discussion demonstrates the relationship between Chretien's ideas, narrative techniques, and characterization as they support the hero's internal growth.^ The study begins with chapters that review prevailing gender influences on Chretien in late twelfth-century France and describe how the poem's organization, character distribution, and writing techniques reflect the poet's vision of duality within and around Perceval. Following this are chapters on how the female and male characters, respectively, interact with and affect the hero's development from an aggressive, thoughtless adolescent who cultivates only his masculine image and vaine gloire to a more mature adult who can express caritas. In Chapter V the wound metaphor is highlighted as a symbol of chivalric violence and singularity in comparison to ritual ceremonies which at the Grail Castle and the Hermitage signify duality as they encompass and reconcile opposites. Chapter VI discusses how Perceval is questing not only to solve the problems at the Grail Castle, but also to find his father (in the form of a sequence of father-figures) and his mother, both of whom were physically/spiritually lost to him before he became a knight. Only when he reconnects with them and expiates his soul can he become an androgynous adult free of sin and balanced in perspective. The scene with the Hermit ultimately makes this possible. ^

Ecology of the circumpolar Antarctic scallop, {\it Adamussium colbecki\/} (Smith, 1902)

Paul Arthur Berkman — Wed, 22 May 2013 16:08:52 PDT

The Antarctic scallop, Adamussium colbecki (Smith, 1902), is relevant to several areas of ecology. A. colbecki has a circumpolar distribution from 3 to nearly 1500 meters depth and can be used to compare nearshore and deep sea habitats. The Antarctic scallop has abundant nearshore populations which remain unexploited and are valuable in the development of living resource conservation strategies. At New Harbor, Antarctica, the size frequency distribution and biomass of A. colbecki have remained relatively unchanged during this decade and may provide a basis for assessing the stability of this population. Seasonal meltwater production from the sea ice and glaciers surrounding New Harbor can influence the growth, recruitment, movement and survival of A. colbecki during the austral summer. The relative zonation of A. colbecki populations along with other Antarctic nearshore benthic assemblages, may be related to changes in the volume of meltwater produced along the continental margin of Antarctica over time scales from hundreds to thousands of years. A. colbecki may be a relict species in the Southern Ocean and a window into the evolution of the Antarctic benthos. ^

A DYNAMIC STUDY OF A PILOT ECKEY HORIZONTAL FRACTIONATOR

ROBERT KINGSLEY ANDREN — Wed, 22 May 2013 16:08:47 PDT

AN INVESTIGATION INTO THE FEASIBILITY AND UTILITY OF GAS PERMEATION FOR THE PROTECTION OF OXYGEN SENSITIVE SYSTEMS

JOAN MARIE LAUSIER — Wed, 22 May 2013 16:08:46 PDT

Childhood maltreatment, posttraumatic cognitions, and health outcomes among young adults

Elizabeth Reichert — Wed, 22 May 2013 16:08:44 PDT

Childhood maltreatment is a significant public health issue that has been linked to a myriad of negative long-term mental and physical health consequences. While the devastating health outcomes have been well established in the literature, the potential mechanisms of this link are less understood. In an effort to elucidate this relationship, the present study examined maladaptive cognitions (i.e., posttraumatic cognitions related to the self and world) that can form as a result of experiencing the trauma of maltreatment. Specifically, this cross-sectional study investigated the association between childhood maltreatment and self-reported mental and physical health concerns among a sample of young adults. Participants were 287 undergraduate students (ages 18-29 years) recruited from a mid-sized northeastern university. Retrospective, self-report questionnaires were used to assess childhood maltreatment, posttraumatic cognitions and current mental and physical health functioning. Data were analyzed using structural equation modeling. Childhood maltreatment was found to be significantly associated with poorer mental and physical health functioning. Support was found for posttraumatic cognitions as mediators in this relationship. Findings provide support for childhood maltreatment as an important risk factor for adverse long-term health outcomes, with posttraumatic cognitions playing an important role in this relationship. Maladaptive cognitions that form as a result of experiencing the trauma of maltreatment may be particularly useful points of intervention in order to mitigate health concerns in adulthood.^

Professional development in historical inquiry: Exploring changes in two social studies teachers' knowledge, beliefs, and practices

Thalia Wood — Wed, 22 May 2013 16:08:43 PDT

Educators in the social studies content area have struggled for over a century with how to best instruct their students in critical thinking. A growing group of researchers in the discipline of history, one of the major components of social studies education, support teaching the domain-specific skills of historical thinking through the process of historical inquiry. Nevertheless, many social studies teachers lack the pedagogical content knowledge to instruct their students in historical thinking skills through historical inquiry. This multiple case study sought to examine how two social studies teachers might change their knowledge, beliefs and practices after engaging in a historical inquiry professional development. The professional development incorporated many of the characteristics of effective teacher learning opportunities. The theoretical frameworks for the study included social constructivist learning theory, expert/novice learning theory, and teacher change theory. Analysis of data from teacher and student interviews, teacher surveys, classroom observations, teacher reflective journals, artifact review, and audio recordings of the professional development sessions revealed significant patterns within and across the two case study participants. Changes observed in the teachers' knowledge, beliefs and practices indicated they were able to instruct their students in historical thinking skills through historical inquiry within their respective curriculums. However, both teachers faced the challenges of curriculum design, time constraints, as well as students' varied development and motivation levels. Findings from this study have implications for how to support social studies teachers as they develop pedagogical content knowledge in historical inquiry in order to teach their students historical thinking skills.^

Self-regulated learning and ethnic/racial variables: Predicting minority first-generation college students' persistence

John S. Moore — Wed, 22 May 2013 16:08:42 PDT

The purpose of this study was to investigate how self-regulated learning and ethnic/racial variables predict minority first-generation college student persistence and related constructs. Participants were drawn nationally from the U.S. Department of Education funded TRiO Student Support Services Programs. Additional participants from the Talent Development program and General Psychology classes from the University of Rhode Island were also included if they were first-generation college students. Preliminary analyses of group differences based on minority status revealed few significant differences in self-regulated learning, ethnic/racial, and college persistence variables. Hierarchical regression analyses indicated that academic self-efficacy, program use, and race rejection sensitivity were the strongest predictors of minority first-generation college students' persistence. Implications for practice, study limitations, and directions for future research are also discussed.^

Brain penetration of tolfenamic acid and its ability to enhance the cognitive functions and to lower amyloid pathology in animal mouse models of Alzheimer's disease

Gehad Mohammed Subaiea — Wed, 22 May 2013 16:08:41 PDT

Alzheimer's disease (AD) is a neurodegenerative disease that is responsible for up to 80% of all dementia cases. Hallmarks of AD include the presence of beta-amyloid (Aβ) deposits and twisted strands of abnormal hyperphosphorylated tau forming neurofibrillary tangles (NFTs), which ultimately lead to damage and death of nerve cells in the brain. Symptoms of the disease include impairments in cognitive and functional abilities that gradually worsen as the disease progress. Finally, in advanced AD, patients become unable to perform basic daily activities, become more susceptible to infections, and ultimately die. Only five drugs are FDA-approved for use in AD, which only provide temporary symptomatic relief without capabilities of modifying the progression of the disease. Tolfenamic acid is a non-steroidal anti-inflammatory drug that has the potential for slowing the progression of AD by inducing the degradation of the transcription factor specificity protein 1 (Sp1). Sp1 regulates the expression of several AD-related genes including amyloid precursor protein (APP), tau and beta-site APP-cleaving enzyme 1 (BACE1). ^ To investigate the ability of tolfenamic acid to cross the blood brain barrier (BBB), multiple approaches were utilized. In silico computational models to predict logBB and logPS for CNS penetration indicated that tolfenamic acid could transfer passively through the BBB. In addition, immobilized artificial membrane (IAM) chromatography using a phosphatidylcholine column was utilized for the in vitro determination of the brain penetration capacity factor [(K_IAM/MW⁴)x10¹⁰] of tolfenamic acid. The results showed that the [(K_IAM/MW⁴)x10¹⁰] for tolfenamic acid was 2.73 indicating its ability to cross the BBB and penetrate into the brain. Upon intravenous (IV) administration of tolfenamic acid to guinea pigs and mice, LC-MS analysis revealed the presence of tolfenamic acid in the extracted brain tissue. This in vivo approach was also used to estimate the brain-to-plasma ratio (Kp) for tolfenamic acid, which was 0.11. Thus, using in silico, in vitro and in vivo methods, we confirmed the ability of tolfenamic acid to cross the BBB. The study offers a guide of using multiple approaches to predict the ability of different compounds to penetrate the brain. ^ Next, we investigated the ability of tolfenamic acid to attenuate the cognitive deficits in a transgenic mouse model of AD, namely R1.40. First, we demonstrated that hemizygous R1.40 mouse model exhibits spatial working and long-term memory deficits when tested in the Morris water maze and Y-maze. We found that short-term administration of tolfenamic acid for 34 days was able to reverse the observed cognitive deficits in hemizygous R1.40 mice. These mnemonic improvements were parallel to reductions in SP1 protein, APP expression and protein, and soluble and insoluble Aβ_40-42 levels. These findings suggest that the reductions in the biochemical markers of AD were also accompanied by functional improvements in the treated mice. ^ We further examined the ability of tolfenamic acid to improve spatial learning and memory as well as to reduce Aβ plaque pathology in old homozygous R1.40. Homozygous R1.40 mice exhibit cognitive deficits that are accompanied by fibrillar Aβ deposition in different regions of the brain by the age of 14-15 months. Our immunohistochemical results indicated that short-term tolfenamic acid treatment for 34 days was able to produce a drastic reduction in Aβ plaque pathology. In addition, spatial working memory, assessed by the spontaneous alternations in the Y-maze, was improved by tolfenamic acid treatment. Further, we investigated if tolfenamic acid would improve the age-related learning and memory impairments in senescent C57BL/6 mice and we found that treatment with tolfenamic acid for 34 days resulted in improvements in the spatial reference memory functions as well. The major findings from these studies suggest that tolfenamic acid crosses the BBB into the brain, is able to decrease AD-related proteins including Aβ plaques, and is able to produce mnemonic functional improvements in AD transgenic mouse model and senescent wild type mice as well. Thus, tolfenamic acid could be proposed as a disease-modifying therapy for AD via its unique mechanism^

On the global behavior of some systems of difference equations

Evelina Giusti Lapierre — Wed, 22 May 2013 16:08:40 PDT

This dissertation is an exposition of systems of difference equations. I examine multiple examples of both piecewise and rational difference equations. ^ In the first two manuscripts, I share the published results of two members of the following family of 81 systems of piecewise linear difference equations: xn+1=xn +ayn+byn+1 =xn+cyn +d,n=0,1,&ldots; where the initial condition (x₀, y₀) ∈ R², and where the parameters a, b, c and d are integers between −1 and 1, inclusively. Since each parameter can be one of three values, there are 81 members. Each system is designated a number. The system's number N is given by N=27a+1+9 b+1+3c+1 +d+1+1. ^ The first manuscript is a study of System(2). System(2) results when a = b = c = −1 and d = 0. For System(2), I show that there exists a unique equilibrium solution and exactly two prime period-5 solutions, and that every solution of the system is eventually one of the two prime period-5 solutions or the unique equilibrium solution. ^ The second manuscript is a study of System(8). System(8) results when a = b = −1, c = 1 and d = 0. For System(8), I show that there exists a unique equilibrium solution and exactly two prime period-3 solutions, and that except for the equilibrium solution, every solution of the system is eventually one of the two prime period-3 solutions. ^ Of the 81 systems, 65 have been studies thoroughly. In Appendix .1, I give the unpublished results of the 21 systems that I studied. In Appendix .2, I list all 81 systems (studied by W. Tikjha, E. Grove, G. Ladas, and E. Lapierre) each with a theorem or conjecture about its global behavior. ^ In the third manuscript, I give the published results of the following system of rational difference equations: xn+1=a1 xn+yn yn+1=a2+b2 xn+ynyn ,n=0,1,&ldots; where the parameters and initial conditions are positive real values. I show that the system is permanent and has a unique positive equilibrium which is locally asymptotically stable. I also find sufficient conditions to insure that the unique positive equilibrium is globally asymptotically stable. ^ In Appendix .3, I give the unpublished results of the following system of rational difference equations: xn+1=a1 xn+yn yn+1=a2+b2 xn+ynB2xn +yn, n=0,1,&ldots; where the parameters and initial conditions are positive real values. I show that the system is permanent. I also find sufficient conditions to insure that the unique positive equilibrium is globally asymptotically stable.^

Comparing visual and statistical analysis in single-subject studies

Magdalena A Harrington — Wed, 22 May 2013 16:08:39 PDT

Objective. There has been an ongoing scientific debate regarding the most reliable and valid method of single-subject data evaluation in the applied behavior analysis area among the advocates of the visual analysis and proponents of the interrupted time-series analysis (ITSA). To address this debate, a head-to-head comparison of both methods was performed, as well as an overview of serial dependency, effect sizes and sample sizes. ^ Method. The comparison of both methods was conducted in two independent studies. In the first study, conclusions drawn from visual analysis of the graphs published in the Journal of Applied Behavior Analysis (2010) were compared with the findings based on the ITSA of the same data; in the second study, conclusions drawn from visual analysis of the graphs obtained from the textbook by Alan E. Kazdin (2011) were used. These comparisons were made possible by the development of software, called UnGraph^® which permits the recovery of the raw data from the graphs, allowing the application of ITSA. ^ Results. In both studies, ITSA was successfully applied to over 90% of the examined time-series data with numbers of observations ranging from 8 to 136. Over 60% of the data had moderate to high level first order autocorrelations (> .40). A large effects size (≥ .80) was found for over 70% of eligible studies. Comparison of the conclusions drawn from visual analysis and ITSA revealed an overall low level of agreement (Kappa = .14) in the first study and moderate level of agreement (Kappa = .44) in the second study. ^ Conclusions. These findings show that ITSA can be broadly implemented in applied behavior analysis research and can facilitate evaluation of the intervention effect, particularly when specific characteristics of single-subject data limit the reliability and validity of visual analysis. Comparison of the two methods revealed low to moderate agreement between visual analysis and ITSA. Overall, the two methods should be viewed as complimentary and used concurrently.^

Unboundedness results for rational difference equations

Gabriel Lugo — Wed, 22 May 2013 16:08:38 PDT

We present a collection of techniques for demonstrating the existence of unbounded solutions. We then use these techniques to determine the boundedness character of rational difference equations and systems of rational difference equations.^ We study the rational difference equation xn=a+xn-1Cx n-2+xn-3,n∈ N. Particularly, we show that for nonnegative &agr; and C, whenever C&agr; = 0 and C + &agr; > 0, unbounded solutions exist for some choice of nonnegative initial conditions. Moreover, we study the rational difference equation xn=a+bxn-1+x n-2xn-3,n ∈N. Particularly, we show that whenever 0 < β < ⅓ and &agr; ∈ [0,1], unbounded solutions exist for some choice of nonnegative initial conditions.^ Following these two results, we then present some new results regarding the boundedness character of the k^th order rational difference equation xn=a+i=1

kbixn-iA +j=1

kBjx n-j,n∈N. When applied to the general fourth order rational difference equation, these results prove the existence of unbounded solutions for 49 special cases of the fourth order rational difference equation, where the boundedness character has not been established yet. This resolves 49 conjectures posed by E. Camouzis and G. Ladas. ^ Finally, we study k^th order systems of two rational difference equations xn=a+i=1

kbixn-i+ i=1

kgiyn-i A+j=1

kBj xn-j+j=1

k Cjyn-j,n∈ N, yn=p+i=1

k dixn-i+i=1

keiyn-iq +j=1

kDjx n-j+j=1

kEj yn-j,n∈N . In particular, we assume non-negative parameters and non-negative initial conditions. We develop several approaches, which allow us to prove that unbounded solutions exist for certain initial conditions in a range of the parameters.^

The impact of predator-prey relationships on the formation of harmful algal blooms in Heterosigma akashiwo

Elizabeth L Harvey — Wed, 22 May 2013 16:08:37 PDT

Heterotrophic protists are the primary grazers of phytoplankton in the marine environment, and changes in the rates of consumption will influence phytoplankton abundance, community composition, and ecological function. The objective of this research was to investigate the influence of predators on the formation and promotion of harmful algal blooms (HABs), specifically blooms of the toxic raphidophyte alga, Heterosigma akashiwo. To observe microscopic predator-prey interactions and their macroscopic distributions, video and image analysis were used to simultaneously quantify population distributions and individual 3D movements of both protistan predators and prey cells in laboratory tanks with realistic salinity structures. In behavioral experiments, the ciliate predator, Favella ehrenbergii did not avoid a layer of H. akashiwo, leading to high ciliate mortality (Harvey and Menden-Deuer, 2011). Contrary to our hypotheses, the presence of Favella sp. caused H. akashiwo to significantly alter its swimming behavior, resulting in avoidance of the predator (Harvey and Menden-Deuer, 2012). This is the first report of predator-induced shifts in the population distribution of a phytoplankton species. Chemical cues were shown to be important in driving predator-prey behavioral shifts. Both predators and prey were shown to shift their movement behavior in response to the presence of only chemical cues, however there was a high level of species-specific responses of both predator and prey (Harvey et al. accepted). Additionally, predator-induced avoidance behaviors in H. akashiwo were also observed in these experiments. The results presented here suggests that H. akashiwo has multiple mechanisms, including toxicity, predator-induced avoidance behaviors, and the use of chemical cues that will result in a reduction in grazing pressure, leading to increased survival and potential for accumulation in this HAB alga. These findings highlight the importance of quantifying the mechanistic basis of organism interactions in addition to bulk growth/loss rates in understanding phytoplankton population dynamics and ultimately the fate of material and energy in the marine food web.^

Teachers developing exemplary inquiry practices: Three longitudinal case studies

Sara Berry Sweetman — Wed, 22 May 2013 16:08:36 PDT

If students are to be successful in the ever-changing scientific world they need to be taught how to think critically, to manipulate materials, and to gather evidence to build knowledge. Most teachers fall short in providing students the inquiry instruction described in the Next Generation Science Frameworks (National Research Council, 2011). This study examined three elementary science teachers' processes as they developed inquiry practices over time. The Electronic Quality of Inquiry Protocol (EQUIP) was used to gather quantitative and qualitative evidence of the teachers' inquiry practices in terms of four factors, Curriculum, Instruction, Discourse, and Assessment. A chronological analysis was used to examine the teachers' professional development and curriculum experiences in relation to their teaching practices. The results showed that all three teachers did change their practice, although the changes varied among cases. For each case, multiple factors influenced the teacher's development. There was a strong positive correlation between the quality of the teachers' inquiry practices and the time spent in curriculum-contextualized professional development. This research indicates that when teachers are supported with curriculum and professional development over extended periods, they develop exemplary inquiry practices. Three recommendations are provided for those interested in implementing science education reform.^

Teacher attitudes: The effects of teacher beliefs on teaching practices and achievement of students with disabilities

Mary Klehm — Wed, 22 May 2013 16:08:35 PDT

Many students with disabilities are not meeting proficiency in the general education setting and achievement scores disaggregated by disability status show that students with disabilities are often not meeting adequate yearly progress targets established by states. A survey was developed to collect data from 218 general and special educators at the middle school level to describe and analyze trends in teacher attitudes and practices that may be affecting the educational experience and achievement of many students with disabilities. The results of these analyses provide information regarding the attitudes of teachers toward the ability of SWD and the fairness and validity of high-stakes testing. Significant differences were found between general and special education teachers' expectations for students with disabilities to benefit from inclusive instruction. Teacher attitude toward the ability of students with disabilities to benefit from inclusive instruction, teacher classification, and the amount of teacher training were all found to be predictors of the use of evidence-based practice. The attitude of teachers toward the ability of students with disabilities to learn and achieve higher level thinking was found to predict proficient achievement scores for students with disabilities on the New England Common Assessment Program (NECAP) achievement test. Finally, differences were found in teacher attitudes toward the ability of students with disabilities to learn and achieve higher level thinking and teacher use of evidence-based practice by content domain.^

Application of the transtheoretical model to behavioral health professionals' readiness to practice integrated primary care

Cerissa Blaney — Wed, 22 May 2013 16:08:35 PDT

Integrated primary care (IPC) has received substantial support with its demonstrated ability to improve access to care, quality of care and health outcomes. Although the benefits of IPC are clear, the integration process has met barriers. One barrier is limited understanding of behavioral health professionals' (BHP) attitudes towards IPC. Better understanding could allow us to improve BHP training and motivation for IPC practice. This study aimed to develop Transtheoretical Model (TTM) measures to assess BHP attitudes toward and readiness to practice IPC using split-half cross-validation procedures. The sample consisted of 319 licensed and practicing BHPs with a stage distribution of Precontemplation 50.6%, Contemplation 2.8%, Preparation 1.6%, Action 6.0%, and Maintenance 39.0%. Exploratory principal components analyses yielded a 2-factor (Pros α=.90; Cons α=.83) 16-item scale for the decisional balance (DCBL) measure, a 1-factor 5-item scale for the self-efficacy (SE) measure (α=.93) and a 2-factor 12-item scale for the IPC Behavior measure (Consultation/Practice Management α=.915; Intervention/Knowledge α=.891). Confirmatory analyses replicated the hypothesized scale structures for DCBL(CFI=.89, AASR=.05, loadings.51-.81), SE (CFI=.90, AASR=.03, loadings .60-.90) and IPC Behavior (CFI=.934, AASR= .04, loadings .63-.91). MANOVA results by stage of change replicated hypothesized patterns for each construct Wilk's Λ= .55, F(15, 834.09)= 13.55, p<.001, multivariate η²=.18. Follow-up tests found significant stage group differences, accounting for between 7% and 41% of the variance. This study demonstrated the applicability of the TTM to this new and increasingly important area; both measures demonstrated good internal and external validity. Future research should explore these measures longitudinally and investigate methods to improve training to increase BHP readiness to practice IPC.^

Effects of Ciona intestinalis Distal-less-B nonexpression and overexpression on phenotype and downstream targets

Matthew David Blanchette — Wed, 22 May 2013 16:08:34 PDT

Ciona intestinalis can serve as a useful model for developmental studies in the chordate lineage due to its basal position in the chordate phylogeny. It shows a simplified chordate body plan during its development, during which important genetic pathways are conserved with vertebrates, and its developmental gene regulation can be manipulated through the insertion of transgenic DNA by electroporation. The Distal-less ( Dll) genes are a family of homeobox genes in chordates that are homologous to the single Dll gene of other metazoan animal groups and code for developmental factors that play a role in determining multiple developmental cell fates. These include broadly conserved roles in appendage development and sensory functions of the central nervous system, as well as more novel roles such as differentiation of the epidermis in chordates. In C. intestinalis, Dll-B transcripts are expressed throughout the prospective epidermis during gastrulation. To study the role of Ci-Dll-B in development, I have produced a transgenic dominant negative form of Ci-Dll-B by making use of the Drosophila engrailed repressor domain (EnR). I then examined its effects on development. Embryos electroporated with this construct showed defects in adhesion of cells in the epidermis. Whole mount in situ hybridization analysis of known Ci-Dll-B downstream targets showed changes in gene expression only in certain targets, suggesting a degree of redundancy in the regulation of the epidermal development program. Phenotypic analysis and immunofluorescent staining of epidermal markers suggest that Ci-Dll-B has a role in the regulation of cell adhesion or differentiation, since Ci-Dll-B knock-down alters the expression pattern of collagen and laminin. I also attempted to identify Ci-Dll-B gene targets through suppression subtractive hybridization, but was unsuccessful. These results are consistent with earlier reports that Dll genes could have a role inducing final differentiation in the epidermis. This work characterizing a key gene in epidermal development may have implications for epidermal development in other chordates, such as mammals.^

Chemical reactions of explosive molecules for detection applications

Christopher A Latendresse — Wed, 22 May 2013 16:08:33 PDT

Explosive analytes and their decomposition products are of great interest to the scientific community, in large part due to events of international terrorism and warfare, but also as environmental pollutants. Chapter 1 of this dissertation shows for the first time that the hydroxide adducts of trinitrobenzene (TNB) and trinitrotoluene (TNT), TNB-OH^- and TNT-OH^-, are emissive while TNT^- is not. This has great impact on pre-existing sensors, which may be affected negatively by an increase in emission competing with the observation of a quench. Additionally, we described a competing reaction with the solvent, N,N-dimethylformamide (DMF), which is also capable of nucleophilic attack upon TNT and observable due to its overwhelming quantity. ^ Chapter 2 of this dissertation shows the similarities of TNT products formed by OH^- exposure and amine exposure, covering a wide variety of amines. ¹H NMR and rapid absorbance measurements showed formation of TNT^- or TNT adducts, the relative rates of which are observed to be strongly dependent on solvation. Intrinsic rate constants in methanol implied that all amine reactions were forming the same adduct (TNT-OCH₃^-). The credibility of amine adduct formation was further explored in Chapter 3 through computational approaches. High level ab initio calculations were performed to obtain models of reactants and products of the investigated reactions, and their relative energies and thermodynamic quantities were computed. The data showed a striking disparity in the calculated thermodynamics, with OH^- and OCH₃^- adduct formation being much more favorable than amine adduct formation. Charge transfer (CT) complexes between TNT and the explored amines were converged and also found to be of higher energy than alkoxide adducts. ^ In Chapter 4, a sensing array based on highly fluorescent reporter molecules in DMF solution is described. Eight xanthene-based fluorophores were chosen based on their high quantum yields, and their interactions with twelve relevant explosive analytes were interpreted through absorbance and emission data. The resulting array showed promise in observing an identifying "fingerprint" response to each class of analyte, with the largest responses coming from the formation of TNB and TNT products. In addition, these products were observed to be involved in an electron transfer (ET) mechanism where they donated energy to cationic fluorophores, enhancing the fluorophores' emission. ^ The findings of this dissertation indicate the need for caution in TNT sensor development, as trace water provides OH^- and common solvents are capable of competing for TNT reactivity. Trace water should be monitored and minimized for appropriate sensor testing and subsequent use, and solution based sensors require an understanding of solvent competition. Amines are not capable of direct deprotonation of TNT, and do not compete significantly with OH^- or alkoxides in forming a sigma adduct with TNT. Rather, the formation of colorful complexes that has been attributed to a TNT-NR₃ adduct in the literature is due to the deprotonation of ambient water or solvent molecules, which in turn react with TNT. Finally, xanthene-based fluorophores may selectively interact with explosive analytes, with trinitroaromatic products capable of electron transfer to fluorescent reporters leading to emission enhancement.^

Nrf2 as a nutrient sensitive transcription factor

Supriya Raghavendra Kulkarni — Wed, 22 May 2013 16:08:32 PDT

The purpose of study performed in MANUSCRIPT I is to elucidate the effect of fasting pathways on Nrf2-Keap1/ARE pathway. Few studies exist regarding how fasting affects transporter or the nuclear receptor-regulated pathways which regulation expression. Fasting effects on the Nrf2-Keap1 signaling pathway, which is responsive to oxidative stress and altered redox status have not been elucidated. The observations presented in this study prove that 1) fasting increases Abcc expression through Nrf2- and Sirt1-dependent mechanisms, 2) cAMP/PKA activators increase ARE activation via Nrf2- and Sirt1-dependent mechanisms in vitro, 3) Nrf2 expression is co-ordinately regulated with Pgc-1&agr; and Sirt1 expression and 4) obesity/steatosis diminishes fasting-mediated Abcc induction. ^ The purpose of study performed in MANUSCRIPT II hypothesized that CR would reverse the NR and drug transporter expression changes previously observed in obesity-induced hepatic steatosis. Given the well-defined association of Nrf2 with Abcc transporter induction, emphasis was placed on the Nrf2 pathway, but other NRs that have been described to regulate transporter expression were also evaluated. Our data herein illustrate that CR differentially regulates NR, biotransformation enzyme, and transporter expression in livers from C57Bl/6 (WT) and Lepob/ob (OB) mice. Furthermore, AMPK and Sirt1 activators differentially modulated transporter and NR expression in lean and steatotic hepatocytes. ^ In MANUSCRIPT III we demonstrate differential susceptibility of a mouse model, constitutively overexpressing Nrf2 (Keap1-KD mice) to CR. We attribute these changes to novel changes in the miRNA regulatory circuit. We demonstrate that the enhanced susceptibility to CR in Nrf2 overexpressing mice could be partly associated with differential changes in miRNA expression such as miR34a, miR370, miR122 and miR144, especially those known to be involved in regulation of lipogenic as well as fatty acid oxidation genes. ^ In summary, the studies presented herein demonstrate Nrf2-ARE pathway is a nutrient sensitive pathway that is: (a) activated upon fasting via Sirt1-Pgc-1&agr; dependent mechanisms, (b) negatively regulated upon CR and AMPK pathway, (c) plays a role in development of obesity, and (d) regulates expression of miRNA regulatory circuit thereby changing susceptibility to weight loss and fatty acid metabolism, (e) is a potential target to alleviate metabolic syndrome. (Abstract shortened by UMI.)^

Impact of metabolic and liver disease on cytosolic sulfotransferase expression and activity

Emine Bihter Yalcin — Wed, 22 May 2013 16:08:31 PDT

The rise in metabolic syndrome is one of the main growing concerns in the developing world since it is estimated to be diagnosed in one third of adults (20 years of age and over) in the United States. Metabolic syndrome has been identified as a factor that may increase the risk of cardiovascular disease and requires having three or more risk factors in an adult including abdominal obesity, high triglyceride, low HDL cholesterol, high blood pressure, and high fasting glucose levels. Nonalcoholic fatty liver disease (NAFLD) is the hepatic compartment of metabolic syndrome, thus characterized as the accumulation of fat in liver in the absence of excessive alcohol intake. The pathology of metabolic syndrome accommodates a complex network including multiple signaling pathways eventually leading to alterations in hepatic gene expression at mRNA and protein levels thus causing altered activity and function in animal models. ^ Drug-metabolizing enzymes play a vital role in the elimination of xenobiotics such as drugs or environmental compounds. In addition, they are involved in the homeostasis of endogenous molecules such as hormones, bile acids or neurotransmitters. Liver is the major organ involved in the metabolism of these exogenous and endogenous molecules. The alterations in drug metabolizing enzyme activity due to metabolic syndrome may affect the clearance of therapeutic drugs, potentially resulting in adverse drug interactions. Due to the increased retention time of the potentially harmful compound,individuals may have a longer exposure to the compound, which may lead to toxicity. The homeostasis of endogenous chemicals also has been found to be affected by the altered levels of metabolism enzymes during metabolic syndrome. The physiological concentrations of steroid hormones, neurotransmitters, bile acids have been detected to be altered in diseased livers. Sulfotransferases are one of the main regulators involved in the biotransformation of these exogenous and endogenous molecules. Our aim is to characterize the hepatic expression and sulfonation capability of this phase II metabolism enzyme family in livers diagnosed with a component of metabolic disease. ^ The initial study reported in chapter three investigates the impact of nonalcoholic fatty liver disease (NAFLD) and alcohol cirrhosis on hepatic sulfotransferases in humans. Sulfotransferase expression and activity decreased significantly with severity of liver disease from steatosis to cirrhosis. SULT1A1 and SULT1A3 activities were progressively lower in disease states relative to non-fatty tissues. Alcoholic cirrhotic tissues further contained lower SULT1A1 and 1A3 activities than either of the two other disease states. SULT2A1, on the other hand, was only reduced in alcoholic cirrhotic tissues. SULT1E1 was reduced in both diabetic cirrhosis and alcoholic cirrhosis tissues, relative to nonfatty liver tissues. ^ The second study presented in the second chapter determined the expression levels and sulfonation capability of major hepatic sulfotransferases in wild type and genetically modified obese mouse models under fed ad libitum,fasted, or calorie restricted conditions. Obesity induced Sult2a1 and Sult1e1, while suppressing Sult1a1 levels. Fasting showed inductive effects on Sult1a1 and Sult1d1. ^ The third study presented in chapter four includes the sulfonation of bisphenol A (BPA), a widely used industrial chemical known as an endocrine disruptor to which humans are regularly exposed. Through glucuronidation and sulfonation, liver metabolizes and facilitates excretion of BPA. Sulfonation of BPA has been reported in primary hepatocytes; several SULT-enzymes efficiently catalyze BPA-sulfate, and BPA-sulfate is a human urinary metabolite of BPA. Therefore, even though being a minor pathway, BPA sulfonation is also expected to efficiently detoxify BPA. We found a dramatic decrease in BPA sulfonation in individuals diagnosed with steatosis, diabetes, and cirrhosis as compared to nonfatty livers indicating that BPA clearance may be decreased in diseased livers. ^ As detected in BPA metabolism, the altered levels of sulfotransferase expression and activity in diseased versus non-diseased liver tissue may affect the metabolism and disposition of many other xenobiotics and homeostasis of endobiotics. This might be a consequence of damaged tissue, but may lead to other cellular events such as xenobiotic accumulation and toxicity due to diminished SULT1A1, alteration in androgen synthesis and metabolism due to modified SULT2A1, alteration in estrogen metabolism due to modified SULT1E1, or accumulation of catecholamines due to diminished SULT1A3 levels in diseased liver.^

Measuring coastal organizations' effectiveness: A small island developing state example

Leslie E Straker — Wed, 22 May 2013 16:08:30 PDT

This study examines effectiveness of coastal organizations in St. Vincent and the Grenadines (SVG), and the relationships among effectiveness and several factors from the organization and management literature known to influence effectiveness, including regional context, demographic and social variables, and type of organization. Perceptions of the general public and those of staff members of coastal organizations in SVG are used for measuring organizational effectiveness. It is posited that as this small state, and others like it in the Caribbean and elsewhere, shift to more holistic management approaches, like Integrated Coastal Management and Ecosystem-Based Management, it becomes necessary to assess how effective the state's sector-based coastal organizations have been in delivering their mandates. Information on sector-based effectiveness can assist in formulating coastal zone management policies that will better serve the needs of small island states, like St. Vincent and the Grenadines. ^ Assessment of coastal organization effectiveness is seen as necessary since existing organizations will still form the basic management units in more holistic management initiatives. The assumption is that careful and transparent consideration of the ways different stakeholders understand management problems is essential to informative and effective dialogue. Also, it is argued that the focus of research on coastal management effectiveness has been on identifying uni-dimensional indicators of success of a program (or project), rather than measuring effectiveness of organizations as the unit responsible for carrying out various programs. This study uses a multi-dimensional approach to evaluate organizational effectiveness. ^ Perception surveys were used to gather data about five coastal zone organizations in St. Vincent and the Grenadines from two stakeholder groups: management staff and the general public. Most of the coastal zone management of the state falls under the mandate of these five organizations: the Central Water and Sewage Authority (a quasi-government organization) and the departments of Fisheries, Forestry, Environment and Planning (government organizations). The community survey was conducted in five communities of the state encompassing two main regions, the Grenadines and the Mainland. In total, 956 community questionnaires from the five communities and 96 staff questionnaires were completed. Mann-Whitney, Kruskal-Wallis, and Spearman Rho tests were the main statistical methods used to investigate relationships among variables. ^ The study found that organizational effectiveness varied among organizations, with the Central Water and Sewerage Authority having greater organizational capacity than other organizations. Also, perceptions of organizational effectiveness varied among stakeholder groups, with management staff more likely than the general public to think organizations were more effective. Certain factors, including region and type of organizations, were found to be related to organizational effectiveness. Demographic characteristics of age and level of education, normally found to be related to environmental attitudes and perceptions, were not related to organizational effectiveness in this study. However, gender showed some relationship with perceptions of organizational effectiveness in the staff survey. ^ The study has a number of implications for coastal zone management in St. Vincent and the Grenadines, and other small island states in the Caribbean and elsewhere. In particular, the study can inform integrated coastal management and ecosystem-based management efforts in St. Vincent and the Grenadines. The study highlights the need for regional considerations in setting coastal zone policies within the state. From a strategic and adaptive perspective, organizations can learn from the experiences of each other to create integrative and ecosystem policies conducive to St. Vincent and the Grenadines. The integration among views of staff and the general public can also play a significant role in facilitating appropriate coastal zone management strategies in St. Vincent and the Grenadines.^

Testing the mechanisms of change for sun protection behavior

Marimer Santiago Rivas — Wed, 22 May 2013 16:08:29 PDT

This study integrates constructs of the Transtheoretical Model of Behavior Change for the examination of sun protection behavior (sun avoidance and sunscreen use) applying a mediation approach using three time points of longitudinal data from individuals in the precontemplation (N=964) and preparation (N=463) stages of change at baseline. The sample used in this study is a portion of a larger sample collected for four multiple-behavior intervention studies. Assessments were collected at baseline, 6-, and 12-month intervals. ^ Structural equation modeling was used to examine longitudinal mediation models. Processes of change were used as independent variables, the pros, cons, and self-efficacy variables were used as mediators, and the sun avoidance and the sunscreen use subscales from the Sun Protection Behavior Scale were used as outcomes. This project involves a series of manuscripts: Study 1-Mechanisms of mediation were explored with participants in the precontemplation stage of sun protection; Study 2-Mechanisms of mediation were explored with participants in the preparation stage of sun protection; Study 3- Model invariance was tested across gender, age, and skin tone groups (precontemplation and preparation); and Study 4 – Model invariance was tested across two stages of change: precontemplation and preparation. ^ There was a strong support for the TTM when model fit, specific paths, and model invariance were evaluated.^

Pharmaceutical cocrystals and amorphous spray-dried dispersions of tenoxicam: Solubility and dissolution enhancement approaches

Jagdishwar R Patel — Wed, 22 May 2013 16:08:28 PDT

In the present work, crystal engineering and spray drying approaches are applied to tenoxicam Form III, a sparingly soluble active pharmaceutical ingredient (API) (<0.1 ug/ml aqueous solubility) within the oxicam class of non-steroidal anti-inflammatory drugs (NSAID). The primary objectives of the study were to investigate the feasibility of applying crystal engineering and spray drying techniques to identify and characterize cocrystals, and generate a stabilized amorphous dispersions of tenoxicam respectively; and determine whether or not the identified cocrystals or generated amorphous dispersions have impact, if any, on the solubility and/or dissolution and stability of a sparingly soluble model drug, tenoxicam. ^ An attempt was made to summarize the relevant widespread current literature to understanding the design strategy of cocrystals, preparation techniques and their limitations, cocrystal formation pathways, crystal engineering strategies evaluation and the potential impact of these strategies on the physicochemical properties of an API in question. Recent advances made in the crystal engineering strategies and the innumerable possibilities for designing cocrystals of pharmaceutical and clinical relevance have been exemplified by several cocrystal case studies. ^ Tenoxicam is a molecule that contains a number of groups capable of hydrogen bonding including amide, pyridyl, phenolic hydroxyl, sulfone, and thiophene functional groups. Therefore, the evaluation of cocrystal design strategy in this study included various carboxylic acids as cocrystal formers representing a wide range of hydrogen bond donors and acceptors. Cocrystals of tenoxicam, were screened, prepared, and characterized using various techniques. Nine phase pure cocrystals of tenoxicam were identified using solvent-drop grinding (SDG) techniques. Structural characterization was performed using powder X-ray diffraction (PXRD), differential scanning calorimetry, and multinuclear solid-state NMR (SSNMR). Solvates and phase mixtures encountered in SDG cocrystal screening were detected using Thermal analysis, PXRD, and 1D SSNMR techniques. Cocrystals formation was confirmed and the structural aspects for the selected cocrystals formed with saccharin, salicylic acid, succinic acid, and glycolic acid are determined using 2D SSNMR methods. Molecular association was demonstrated using cross-polarization heteronuclear dipolar correlation (CP-HETCOR) methods involving ¹H and ¹³C nuclei. The local aspects of the cocrystal structure were revealed by Short-range ¹H-¹³C CP-HETCOR and ¹H-¹H double-quantum interactions between atoms of interest, including those engaged in hydrogen bonding. The ionization state and the potential for zwitterionization in the selected cocrystals were assessed by ¹⁵N SSNMR. The tenoxicam saccharin cocrystal was found to be similar in structure to a previously-reported cocrystal of piroxicam and saccharin. Comparative evaluation studies on dissolution for four selected cocrystals yielded intrinsic dissolution rates similar or reduced relative to tenoxicam Form III. ^ Amorphous spray dried dispersions were prepared using L-arginine as a solubilizer. The physical properties of these dispersions were improved by adding Polyvinylpyrrolidone (PVP) as a stabilizer. Results of the study indicated that dispersions containing a 1:2 ratio of tenoxicam:L-arginine with 10% to 50% w/w PVP provided a twofold increase over equilibrium solubility of Tenoxicam at the same pH. Accelerated stability studies performed at accelerated conditions for one month demonstrated that the dispersions exhibit acceptable physical properties with only a minor decrease in chemical stability. In conclusion, for amorphous SDD study, SDDs prepared with tenoxicam, L-arginine and PVP exhibited greatly enhanced dissolution, acceptable physical properties, and sufficient stability for development. SSNMR methods are useful in elucidating structural properties, molecular association, and the formation of a glass solution between tenoxicam, L-arginine and PVP. (Abstract shortened by UMI.) ^

Relationships between gender, socioeconomic status, math attitudes, and math achievement: An international investigation

Sunny R Duerr — Wed, 22 May 2013 16:08:27 PDT

The relationships between gender, math attitude, and math achievement have traditionally been studied within individual countries, despite the existence of large international data sets available for analysis. This dissertation investigated the relationships between gender, math attitude, and math achievement based on information from 50 participating countries in the Trends in International Mathematics and Science Study (TIMSS). Countries were first grouped into clusters using hierarchical cluster analysis, and these clusters were validated on separate samples using discriminant function analysis. Multiple-group latent variable modeling was employed between clusters and within clusters to assess the nature and strength of the relationships between gender, math attitude, and math achievement. ^ The findings suggest that math self-confidence has a particularly strong relationship with math achievement, and that value of math has a particularly weak relationship with math achievement. Additionally, gender differences in math achievement appear to have disappeared or now favor female students, but male students report generally higher levels of math self-confidence. Implications are discussed, along with limitations and suggestions for future research.^

An investigation of the physico-mechanical properties of pharmaceutical compounds by compaction simulator and nano-indentation

Mangesh Bordawekar — Wed, 22 May 2013 16:08:26 PDT

In early development, pharmaceutical formulation scientists are often faced with challenges of developing robust and scalable formulations in extremely stringent timelines based on limited API quantities. Hence, tablet formulation development would benefit significantly from tools that enable predictive analysis based on limited quantities of API to enable selection of excipients with appropriate physico-mechanical properties that would result in robust and scalable formulations. ^ With the recent technological advances, especially in sensor technologies, tools such as the compaction simulator, and instrumented nanoindentation offer hitherto unavailable means of assessing material properties with limited quantities. The goal of this work was to evaluate the physico-mechanical properties of selected pharmaceutical excipients and active pharmaceutical ingredients using a macro-scale analysis technique (compaction simulator), and a micro-scale analysis technique (nanoindentation tester) and compare the results obtained from these techniques in order to determine whether a rank order correlation exists between the two. Excipients representing diverse physic-mechanical properties, and a group of APIs were selected for the study. ^ For the compaction simulator studies, tablets were uniaxially compressed using a flat faced 11.28mm round tooling on the STYLCAM^® 200R compaction simulator, to a target final porosity at two different cam speeds (5 rpm and 25 rpm). The force displacement profiles, plastic, elastic, and total compression energies, plasticity index, energy density and the Heckel plots were determined for each compact. These compacts were further analyzed with a Berkovich geometry indenter. The plasticity index, hardness, elastic modulus, as well as creep and relaxation were determined from the force-displacement profiles. The nature of force-displacement curves was studied to differentiate compounds based on predominant mechanisms of deformation. Compaction simulator was able to rank order the selected compounds based upon their established physic-mechanical properties. Further, the nanoindentation analysis suggests that characterization of excipients and compounds correlated well with their known mechanisms of deformation and with the process parameters (e.g. compression dwell time). These results demonstrate that nanoindentation can be potentially employed in early formulation development, to understand the physico-mechanical properties of active pharmaceutical ingredients and predict their compaction behavior. Lastly, a rank-order correlation was observed between the two techniques suggesting that either technique can be employed to get valuable insights into the properties of APIs, to help speed up the development process. ^

Three essays on the credit enhancement of corporate bonds and firm value

Fang Chen — Wed, 22 May 2013 16:08:26 PDT

This dissertation consists of three essays on credit enhancement (CE) of corporate bonds and firm value. The first essay presents the evidence that CE use is negatively associated with firm value and firms issuing debt with CEs underperform those without. Further evidence suggests that better investment opportunities and more debt use help alleviate the negative CE effect. The second essay examines the financial cost of using CE on corporate bonds. It shows that for investment grade bonds, CE on average inflates the bond yield spread by 23 basis points. In a sharp contrast, for speculative bonds, CE on average lowers the bond yield spread by 60 basis points. Further investigation reveals that the effect of CE is a joint effect of credit rating enhancement and increased expected equity idiosyncratic volatility. Finally, the third essay reports that the underperformance of a special type of credit enhancer, credit risk insurers (CRIs), during the 2007-2009 financial crisis is mainly attributed to the greater systemic risk of CRIs. It also shows the credit spreads of insured bonds increase significantly after their insurers are downgraded or put in the negative watch list.^

Using molecular techniques to examine iron limitation in Thalassiosiroid diatoms

LeAnn Pritchard Whitney — Wed, 22 May 2013 16:08:25 PDT

Large areas of the oceans have been characterized as having such low levels of iron (Fe) that the growth of diatoms in these regions is restricted. The persistence of diatoms in these nutritionally deficient waters indicates these organisms may have developed methods of coping with chronic Fe stress. Many studies have indeed shown that the response to Fe limitation differs among diatom species with some growing at maximal or near maximal rates in levels of Fe that severely restrict the growth of others. The molecular underpinnings driving these physiological differences are poorly understood. The goal of this dissertation was to characterize the diatom molecular response to Fe limitation and identify gene targets that can be used to assess the Fe nutritional health of natural diatom assemblages. Quantitative transcriptomic and proteomic methods were used to describe the molecular response to Fe limitation of the diatom Thalassiosira pseudonana. Comparing the changes induced in T. pseudonana to other diatoms revealed molecular and functional differences among species, including the gene encoding flavodoxin that is the non-Fe containing substitute for ferredoxin. T. pseudonana has a single copy of flavodoxin that is not regulated by Fe, while other diatoms can have two copies including the Fe responsive copy. These results suggest species-specific gene markers may be the best way to illuminate Fe limitation of diatoms in the field. Genes encoding flavodoxin and Fe-starvation induced protein (ISIP3) were tested as markers in Thalassioisira oceanica, an ecologically important diatom described as being highly tolerant to Fe stress. Their expression was strongly induced under Fe stress with nominal changes in other growth conditions. Flavodoxin and ISIP3 expression was measured in samples collected from the northeast Pacific Ocean that traversed through a range of Fe concentrations. Expression in wild T. oceanica cells was detected at all locations with changing levels responding to Fe availability. These results support the use of these species-specific markers to indicate the severity Fe limitation in T. oceanica that may be extrapolated to suggest the whole diatom community is Fe limited.^

Measuring the influences that affect technological literacy in Rhode Island high schools

Michael Walach — Wed, 22 May 2013 16:08:24 PDT

This study assessed the current state of technological literacy in Rhode Island high schools. Possible factors that lead to high levels of technological literacy were identified. Gender inequalities in technological literacy were discovered and possible causes and solutions are presented. This study suggests possible next steps for technology teachers, teacher educators, curriculum developers, and policy makers, to move technology education forward, and lays the groundwork for further studies of technological literacy. The International Technology and Engineering Education Association (ITEEA) Standards for Technological Literacy (ITEEA, 2000/2007) were used as the benchmarks measured in this study. ^

Gendered patterns in high achievement in mathematics for grades 4, 6, and 8

Laura J Falvey — Wed, 22 May 2013 16:08:23 PDT

The issue of underrepresentation of women in science, technology, engineering, and mathematics (STEM) careers is especially important to the future of the United States in current times when STEM careers play an increasingly important role in the global economy (Toulmin & Groome, 2007; United States Department of Labor, 2007). The pool of students who enter careers in science, technology, engineering, or mathematics first appear in elementary school and overwhelmingly come from those with high achievement in mathematics (Berryman, 1983; Tai, Liu, Maltese, & Fan, 2006). ^ This study examined mathematics achievement data from grades 4, 6, and 8 in one northeastern state to determine whether inequitable patterns exist along gendered lines. This study used quantile regression methodology to examine mathematics achievement as a function of gender and other student characteristics to reveal if differences exist in the top percentiles of achievement densities for this population. The use of a quantile model enabled the capture of any percentile of the distribution to reveal changes by student characteristics, allowing a more precise picture of achievement in mathematics than could be revealed by means-based methods. ^ Results of the analyses required a rejection of the null hypothesis there is no difference in mathematics achievement by gender in this population. Further, the point advantages and disadvantages revealed are potentially important for both males and females and may reflect impactful patterns of achievement at both the high and low ends of achievement in mathematics. Additionally, students with lower socioeconomic status, limited proficiency in English, and/or membership in a racial minority were also found to be negatively impacted in these data.^

Prednisolone pharmacokinetics and pharmacodynamics in diabetic and non-diabetic kidney transplant recipients

Ileana A Ionita — Wed, 22 May 2013 16:08:23 PDT

More than 50% of kidney transplant recipients have diabetes mellitus. The objective of this project was to characterize the effect of diabetes on the pharmacokinetic (PK) and pharmacodynamic (PD) of the immunosuppressive agent, prednisolone. The study included 20 diabetic and 18 demographically matched nondiabetic stable kidney transplant recipients. Two simple, sensitive and specific bioanalytical methods have been developed and validated to measure total and free corticosteroids concentrations in human plasma using LC-MS/MS. Measured analytes included prednisolone and its inactive pro-drug prednisone as well as endogenous cortisol and cortisone. Additionally, we have estimated the parameters of the pharmacodynamic profile of prednisolone through a population pharmacodynamic analysis using a nonlinear mixed effect model (NONMEM). Total and free prednisolone exposures were 27% and 23% higher, respectively and Tmax was 50% higher in diabetic subjects compared to nondiabetic subjects. Using NONMEM, the protein binding characteristics of prednisolone were determined by fitting free and bound concentrations of prednisolone with a nonlinear equation including the affinity constants of prednisolone and cortisol to corticosteroid binding globulin (KCBG,PL and KCBG,C) and a binding constant of prednisolone to albumin. KCBG,PL was 20% higher in diabetic and 22.5% higher in male patients, while KCBG,C was directly proportional with body mass index and glycated hemoglobin. The pharmacodynamic characteristics of prednisolone were estimated by combining the inhibitory effect of prednisolone on cortisol production with a biexponential decline of cortisol to describe cortisol concentrations in plasma. Diabetes, HDL-cholesterol (HDL-C) and the polymorphism of CYP3A5*3 gene were significant covariates. As the levels of HDL-C increase, the slope of cortisol decline is smaller. The intercept of cortisol concentration was lower in subjects carrying the wild type of CYP3A5 allele (nonexpressers). Moreover, production of cortisol was higher in subjects with diabetes. In conclusion, the body of this work demonstrates that both prednisolone pharmacokinetics and pharmacodynamics are different in diabetic stable kidney recipients. Prednisolone exposure and protein binding characteristics are significantly affected by diabetes so as the level of endogenous cortisol under chronic prednisolone therapy.^

Assessment of the success or failure of stormwater regulations through numerical analysis

Steven M Cabral — Wed, 22 May 2013 16:08:22 PDT

With the catastrophic flooding events of March 2010, the State of Rhode Island received a memorable reminder of its susceptibility to widespread flooding. A critical segment of the State's major interstate highway was under Pawtuxet River floodwaters and thousands of homes and businesses were damaged. The days preceding the major flood delivered a series of precipitation events, but no event created alarm that such historic river levels would occur. The event could be viewed as a consequence of a natural anomaly, past urbanization and other manmade actions. Independent of the primary cause, a factor which impacts past and future flooding of the State's river systems are the regulatory stormwater standards which dictate mitigation requirements for land alterations and development. ^ In recognition of the importance of design standards, the Rhode Island Department of Environmental Management (RIDEM) and the Coastal Resources Management Council (CRMC) completed a multi-year effort in 2010 of updating the State's stormwater standards. The stated goal was to implement the most current scientific theory and engineering practice in future stormwater systems. The published stormwater Manual deserves credit for providing significantly more design guidance than its predecessor, but it also provides flood mitigation design mandates with minimal to no protection of the State's major river systems. The effectiveness of the State's past and current stormwater regulations and their ability to safeguard major river systems from increased flooding have never been numerically evaluated and are the focus of this research project. ^ The evaluation will proceed through a review of current stormwater polices which are used nationwide to assess if the new standards are conventional, proven and/or the most current measures available. An historical assessment of hourly precipitation data and peak river flows of local rivers systems will also be performed to evaluate the region's actual climate patterns for comparison with the required design protocols, which in the past and today are embedded with a 24 hour NRCS Type III storm event and NRCS Runoff CN Methodologies. The study will proceed through a review of the State's mandated technical methods associated with flood protection. Hydrologic modeling of stormwater systems which were originally designed in accordance with either past or present standards will be performed followed by a numerical and sensitivity analysis of the methods. Impacts on the performance of stormwater systems due to potential climate changes will also be examined. The study presents a definitive conclusion that although the Manual provides improvements to past standards, in regards to flood protection it does not represent the most current scientific theory, possesses technical deficiencies and does not protect our major river systems from exacerbated flooding due to land alterations. The notable deficiencies include the mandated use of a synthetic design storm with an event duration which seldom coincides with severe river flows and mathematical and scientific shortfalls within the required design model, the NRCS Runoff CN Method. To have an effective stormwater protection strategy which has the greatest potential of protecting the State's major river systems, a long term goal is the development of validated hydrologic models of each of the State's major river systems which would be permanently managed and updated by one entity. The hydrologic model would then be utilized by designers to confidently address cumulative watershed consequences of land alterations and mitigation strategies. Interim short term recommendations which provide more effective design modeling in advance of comprehensive watershed modeling are also provided. Short term recommendations address amendments to the underlying basis of stormwater design related to flood mitigation and address the design storm event and technical aspects of the modeling requirements in addition to seasonal and climatic issues.^

Mechanisms of protection of probiotics against bacterial pathogens in oyster aquaculture

Murni Marlina Abd Karim — Wed, 22 May 2013 16:08:21 PDT

Oysters are filter feeders and thus continuously exposed to large numbers of microbes present in the marine environment. The Eastern oyster, Crassostrea virginica is one of the most recognized aquatic species in the United States. Two major bacterial pathogens that have a serious impact on this species are Roseovarius crassostreae and Vibrio tubiashii. Probiotics are an environmental friendly method of disease management that potentially can control the proliferation of pathogens in the hatchery or farm. However, little is known about the actual mechanisms of action of probiotics. The goals of this study were to isolate potential local probiotic species for the control of infectious diseases in C. virginica culture and to investigate the mechanisms of probiotic action. ^ The present study successfully isolated two candidate probionts able to protect larval oysters C. virginica against V. tubiashii (Relative Percent Survival, Bacillus pumilus RI06-95: 29 ± 3 % and Phaeobacter sp. S4: 55 ± 2 %) and R. crassostreae (RPS, B. pumilus RI06-95: 42 ± 3 % and Phaeobacter sp. S4: 49 ± 3 %). Phaeobacter sp. S4 was isolated from the inner shell of healthy oysters and was identified to produce the antibiotic compound trophoditietic acid (TDA). This probiont was able to inhibit the growth of pathogens in an in vitro assay as well as significantly increase the survival of larval oysters in an in vivo bacterial challenge assay. Candidate probiont B. pumilus RI06-95, previously isolated from a marine sponge from Narrow River, RI, is known to produce the antibiotic amicoumacin. This candidate probiont showed antibiotic activity against R. crassostreae in an in vitro assay and protection of larval oysters to bacterial challenge. ^ In order to determine the relative roles of biofilm formation and antibiotic production on probiotic activity, several mutants of Phaeobacter sp. S4 were created. Mutants tdaA^-, tdaB^- and tdbD^- no longer produce TDA and exhibit reduced biofilm formation; mutant clpX^- forms normal biofilms without TDA production, mutant exoP^- produces TDA but shows significantly decreased biofilm formation, and mutant rpoE- displays a similar phenotype to the wild type but shows a delay in TDA production. Our results shows the tdaA^-, tdaB^- and tdbD^- mutants conferred significantly decreased protection to oysters challenged with V. tubiashii (tdaA^- 24 ± 2 %, tdaB- 24 ± 4 %, tdbD^- 23 ± 2 %). Meanwhile, mutant clpX^- and exoP^- conferred partial protection (clpX^-: 33 ± 2 % and exoP-: 35 ± 8 %) and mutant rpoE^- conferred protection just slightly lower than the wild type (rpoE^- 54 ± 2 %). This study demonstrates that both TDA production and biofilm formation play a critical role in probiotic activity of Phaeobacter sp. S4. However, based on the fact that mutants with no ability to produce TDA and biofilm defective were still able to provide a small level of protection to bacterial challenge in larval oysters, we speculate that mechanisms other than antibiotic production and biofilm formation may be involved in the probiotic activity of Phaeobacter sp. S4. ^ In conclusion, probionts Phaeobacter sp. S4 and B. pumilus RI06-95 were able to protect oysters against bacterial challenge. The mechanism of actions of these probionts was proved to be complex, with production of the antibiotic TDA and an ability to form biofilms playing a major role in the probiotic activity of Phaeobacter sp. S4, and the ability to immune-modulate the responses of the host also providing a small contribution. Further research should be done in order to evaluate other potential mechanisms that may be involved in probiotic activity. (Abstract shortened by UMI.)^

Detection and quantification of dithiocarbamate pesticides by Surface Enhanced Raman Spectroscopy (SERS)

Benjamin Calvin Saute — Wed, 22 May 2013 16:08:21 PDT

Dithiocarbamates are a subclass of carbamate pesticides that are widely used as insecticidal agents on food crops in the US and abroad. Quantitative determination of trace quantities of dithiocarbamates is necessary in order to mitigate potential human exposure via pesticide residues left on inadequately washed food items as well as groundwater contamination from agricultural runoff. The focus of this research is on the development and optimization of a Surface Enhanced Raman Spectroscopy (SERS) based analytical technique for the quantitative determination of trace amounts of dithiocarbamate pesticides in different matrices. Gold nanoparticles of different shapes and sizes will be investigated to determine the suitability of these materials as SERS active substrates for the trace analysis of dithiocarbamate pesticides. Analytical sensitivity will be evaluated by determining the limits of detection using established statistical methods.^

Multiple behavior analytical techniques

Hisanori Kobayashi — Wed, 22 May 2013 16:08:20 PDT

To further progress in multiple health behavior theory and research, simultaneously investigating relationships across multiple behaviors is crucial. New methodology, including analytical methods, measurement foundations and composite outcome measures, require having a capability of simultaneously evaluating multiple behaviors. The main objective of these three studies was to demonstrate three multi-behavioral analytical strategies to further develop methodology for multiple health behavior research (MHBR). The first study examined measurement invariance across three behaviors: dietary fat reduction, smoking cessation, and physical activity for 784 adults who were at risk for all three behaviors. The results generally supported the measurement invariance of the decisional balance and self-efficacy constructs across all three behaviors (including factor loadings and correlations), as well as successfully demonstrated the application of measurement invariance for comparing different sets of items. As expected, item means invariance was not obtained. These results suggest that MHBR has a solid measurement foundation for at least these two constructs and three behaviors. The second study investigated underlying profiles of progression through the stages of change for three behaviors using Latent Class Analysis (LCA) for two different samples (N = 716 adults, N = 679 early adolescents). Two-class solutions appeared to provide the best fit, including a Progression Group and a Stable Group. The number and interpretation of the latent classes and class membership probabilities were generally similar for both samples. Significant intervention effects were found in both samples. These results demonstrate the potential LCA has as a new analytical framework for MHBR. The third study compared a set of multi-behavioral outcome measures that summarizes multiple independent behavioral outcomes for the same adults for the second study. The sum of residual scores consistently showed a higher sensitivity than sum of z scores for evaluating the treatment effects, and the count of progressed behaviors consistently showed a highest sensitivity in the stage-based composite outcome measures on an absolute basis. For successful MHBR, these two multi-behavioral outcome measurements have the potential to be standard outcome measures. These three studies addressed methodological issues to further the development of MHBR from different perspectives and have provided valuable insights.^

Modelling and analysis on smart grid against smart attacks

Jun Yan — Wed, 22 May 2013 16:07:38 PDT

Modern power systems worldwide are facing a rising appeal for the upgrade to a highly intelligent generation of electricity networks commonly known as the Smart Grid. Advanced monitoring and control systems like Supervisory Control And Data Acquisition (SCADA) and Advanced Metering Infrastructure (AMI) systems have been widely deployed and management based on them provides more flexible and achievable optimal control of power generation, transmission and distribution. However, the growing integration of power system with communication networks also brings increasing challenges to the security of the modern power grid, from both cyber and physical space. Malicious attackers can take advantage of the increased access to the monitoring and control of the system and exploit some of the inherent structural vulnerability of power grids. Motivated by these security challenges, the goal of this thesis is to facilitate the understanding of power grid outages and blackouts triggered by these attacks, to analyze the cascading process that leads to the impactful events, and to support the decision making in defense and protection for a reliable and secure Smart Grid around the corner. Simulation results from real-world power system benchmarks have been analytically discussed from both the spatial and temporal perspectives and important decision-support information have been revealed through several chapters of the thesis. This research is part of an ongoing National Science Foundation (NSF) funded Smart Grid security project led by Dr. Haibo He, Dr. Yan (Lindsay) Sun from the Electrical Engineering Department and Dr. Peter August from the Natural Resources Science Department, all at the University of Rhode Island.^

Survival of the blacktip shark, Carcharhinus limbatus

William A Swinsburg — Wed, 22 May 2013 16:07:37 PDT

Proportional survival (S) is a crucial life-history parameter in population dynamics, natural selection, and management of harvested stocks; variations in survival due to age, sex, or geographic region may have large effects on the success of managing fish stocks. The blacktip shark, Carcharhinus limbatus, is the most abundantly harvested shark species in American fisheries. Direct estimates of survival are preferred, but all current survival estimates for this species are either focused on young-of-the-year (YOY) or based on indirect methods. The objectives of this study were to determine whether age, sex, or geographic grouping affects survival and to generate direct survival estimates based on tag-recovery data. As a byproduct of this analysis, distribution maps and descriptive data summarizing captures were included. The U.S. National Marine Fisheries Service has been collecting tag-recovery data since 1962 through the Cooperative Shark Tagging Program (CSTP). Models were generated from this database with program MARK, ranked in order of parsimony according to Akaike's Information Criterion, and tested for significance of effects with likelihood ratio tests. No movement has been observed to date between the west Gulf of Mexico, east Gulf of Mexico, and U.S. Atlantic, but 2 sharks tagged in the U.S. Virgin Islands were recaptured off Florida and Georgia (displacement= 1049 and 1183 n. mi., respectively). Survival did not differ significantly for males vs. females (P=0.761), east vs. west Gulf of Mexico (P=0.654), or U.S. Atlantic vs. Gulf of Mexico (P=0.243). However, significant differences were found for survival of YOY (0.580) and post-YOY (0.725) within the Gulf of Mexico (P=0.0003). These results demonstrate that survival can be modeled effectively for species in the CSTP with relatively small sample sizes. Future analyses may benefit from a length-based model, due to the difficulty in assigning life stages based on size.^

Progress monitoring for prerequisite social skills: A generalizability study for measure development

Monica Mabe — Wed, 22 May 2013 16:07:36 PDT

Social skills are important components of social-emotional functioning that allow children to be successful in both the social and academic spheres of school. A review of social skills intervention literature is presented including issues influencing effectiveness. Concerns associated with assessing the effects of social skills interventions are discussed and a formative assessment tool for behavioral observation is presented. The use of generalizability theory is then examined as a psychometrically based approach to developing a measure for observing social skills. Four prerequisite social skill areas were identified: (a) Attending, (b), Raise Hand, (c) Hands to Self, and (d) Transition. Transition was divided into two components for a total of five observed skills. Students in an elementary school were observed during regular classroom activities on three different occasions for each skill. The reliability of this strategy was evaluated in order to assess the optimal number of occasions and observers needed in order to obtain adequate degrees of reliability. Results identified particular skills that can be observed more reliably than others, and what combination of parameters might lead to optimal reliability. Preliminary descriptive analyses suggest that ethnicity might play a role in student performance of specific skills. Results are discussed in terms of applied use for the measure in school settings for formative assessment and in terms of directions for future research.^

1891 AD submarine eruptive processes and geochemical studies of floating scoria at Foerstner volcano, Pantelleria

Joshua Kelly — Wed, 22 May 2013 16:07:35 PDT

On October 17, 1891 a submarine eruption occurred at Foerstner volcano in the Straits of Sicily 4 km northwest of the island of Pantelleria, Italy. The eruption produced floating scoria bombs, or balloons, that discharged gas at the surface and eventually sank to the seafloor. Activity occurred for a period of one week from an eruptive vent located within the Pantelleria Rift at a water depth of 250 m. ^ Remotely Operated Vehicle (ROV) video footage and high resolution multibeam mapping of the Foerstner vent site was used to create a geologic map of the 1891 AD deposits and conduct the first detailed study of the source area associated with this unusual type of submarine volcanism. The main Foerstner vent consists of two overlapping circular mounds with a total volume of 6.3 x 10⁵ m³ and relief of 60 m. It is dominantly constructed of clastic scoriaceous deposits with some interbedded effusive pillow flow deposits. Petrographic and geochemical analyses of Foerstner samples by X-ray fluorescence and inductively coupled plasma mass spectrometry reveal that the majority of the deposits are highly to extremely vesicular, hypocrystalline tephrite basanite scoria that display porphyritic, hyaloophitic, and vitrophyric textures. An intact scoria balloon recovered from the seafloor consists of an interior gas cavity surrounded by a thin lava shell comprised of two distinct layers; a thin, oxidized quenched crust surrounding the exterior of the balloon and a dark grey, tachylite layer lying beneath it. Ostwald ripening is determined to be the dominant bubble growth mechanism of four representative Foerstner scoria samples as determined by vesicle size distributions. ^ Characterization of the diversity of deposit facies observed at Foerstner in conjunction with quantitative rock texture analysis indicates that Strombolian-like activity is the most likely mechanism for the formation of buoyant scoria bombs. The deposit facies observed at the main Foerstner vent are very similar to those produced by other known submarine Strombolian eruptions (short pillow flow lobes, large scoriaceous clasts, spatter-like vent facies). Balloons were likely formed from the rapid cooling of extremely vesicular magma fragments as a result of a gas-rich frothy magma source. The exterior of these fragments hyperquenched forming a vesicular glassy shell that acted as an insulating layer preventing magmatic gas in its interior from escaping and thus allowing flotation as densities reached less than 1000 kg/m³. We believe that lava balloon eruptions are more common than previously thought, as the eruptive conditions required to generate these products are likely to be present in a variety of submarine volcanic environments. Additionally, the facies relationships observed at Foerstner may be used as a paleoenvironmental indicator for modern and ancient basaltic shallow submarine eruptions because of the relatively narrow depth range over which they likely occur (200-400 m).^

Eigenvalue pairing for direction finding with vector sensor arrays

Kyle T Martin — Wed, 22 May 2013 16:07:34 PDT

This thesis introduces a novel sorting pairing method for the azimuth-elevation estimates obtained from the Estimation of Signal Parameters via Rotational In- variance Techniques (ESPRIT) based closed-form source localization algorithm. The ESPRIT algorithm estimates Direction of Arrival (DOA) angles from a given source using arbitrarily spaced three-dimensional arrays of vector sensors, whose locations need not be known. In estimating the DOAs there can be miss-pairings of DOA azimuth and elevation direction cosines in certain cases. In such cases, the incident angles calculated can be permuted which produces miss matching of angles or misses. The sorting pairing method presented exploits the order of eigenvalues and thereby the DOAs estimated from the ESPRIT algorithm. The sorting pairing method is compared to two other pairing methods: the traditional pairing method, a method that is simplistic in nature when dealing with misses; and the exhaustive pairing method, a method that exhaustively attempts to find the eigenvalue pairing that yields the least amount of error. Simulation results provides strong evidence that the sorting pairing method gives good results over a much larger range of signal-to-noise ratios than the traditional method, and has an accuracy that is nearly co-linear with the exhaustive method.^

Psychometric validation of the four factor situational temptations for smoking inventory in adult smokers

Hui-Qing Yin — Wed, 22 May 2013 16:07:33 PDT

The situational temptations for smoking inventory assesses the degree of temptation a person might feel to smoke across a variety of situations found to be important for smoking cessation. The temptations measure with four subscales, Positive/Social (PS), Habit Strength (HS), Negative/Affective (NA), and Weight Concerns (WC), was previously validated among adolescent smokers. The measure that has been validated in adults includes only the PS, HS, and NA subscales, although weight concerns are also salient to adults who smoke and have been negatively associated with smoking cessation. This study examines the psychometric validity of the temptations measure with the addition of the WC subscale, including stability of the measurement model, using a population-based sample of adults who reported being current smokers (N = 2921, age range 18-82 years, 68.6% white, 55.3% female). Participants in the sample had complete data for the measure, and those with extreme response patterns were deleted. Confirmatory factor analyses (CFA) showed that theoretically based four-factor (PS, HS, NA, WC) models fit the measure well (CFI: .967, RMSEA: .052), with moderate to high internal consistency for all subscales (α .55 - .91). Multiple sample CFA established that the factor structure of the temptations measure was invariant across population subgroups defined by gender, age, racial identity, ethnicity, stage of change for smoking cessation, baseline smoking severity, and weight status. Measurement invariance testing using multiple sample analyses of mean and covariance structures showed that the invariance models fit well across stage of change, racial identity, ethnicity, and weight status at the level of strong measurement invariance. These results indicate a consistent relationship between the four factors (PS, HS, NA, WC) of the situational temptations for smoking measure, and the twelve items that serve as their measured indicators, confirming the internal validity of the measure in adult smokers. Multivariate analysis of variance revealed a small but significant effect of stage of change on the temptations subscale scores, demonstrating that the temptations measure can differentiate between adult smokers in the early stages of change for cessation. ^

Evaluating the efficacy of a nutrition education mini lesson series

Elizabeth B Patnode — Wed, 22 May 2013 16:07:32 PDT

Objective: To assess the impact of a nutrition education mini lesson series on children's knowledge and fruit and vegetable consumption. ^ Design: Quasi-experimental pre-/post-test design with two study conditions (experimental and control). Setting: Four (4) Boys & Girls Clubs in Providence, Rhode Island. ^ Participants: Eighty-four (84) children ages 5-11 years. Intervention: Participants in the experimental group received a 4-week fruit and vegetable nutrition education series. Subjects in the control condition received 2 lessons unrelated to fruits and vegetables. Children from both the experimental and control groups completed pre- and post-surveys one week before and after the intervention. ^ Main Outcome Measures: Knowledge of recommended fruit and vegetable intakes and fruit and vegetable consumption. ^ Results: The intervention group increased fruit and vegetable knowledge as compared to the control group (p<0.05). There were no differences between groups for fruit and vegetable consumption. No relation was found between attendance rate and consumption among participants in the experimental condition. ^ Conclusion and Implications: This intervention effectively increased fruit and vegetable knowledge of children ages 5-11 years in an afterschool care setting. Future research is needed to determine if adopting additional or alternate intervention techniques can improve the behaviors of children in this setting.^

College students' perceptions of professor bullying

Marisa E Marraccini — Wed, 22 May 2013 16:07:29 PDT

Although bullying research has burgeoned over the past two decades, only recently have studies begun to explore bullying of students by teachers. Preliminary findings suggest that teacher bullying and the maltreatment of students may result in loss of trust, feelings of hopelessness and depression, oppositional behavior and increased fighting amongst peers (Pottinger & Stair, 2009). To date, only one study (Chapell et al., 2004) has addressed the prevalence of teacher (professor/instructor) bullying in college student populations. Given the impact professor/instructor relations can have on college student outcomes (Wilson et al., 2010) and the severe consequences teacher bullying can have on primary and secondary students, it is important to identify whether college students report bullying by their professors/instructors. The present study examined the self-reported prevalence of instructor bullying among college students. Results revealed that 51% of students endorsed seeing another student being bullied by a professor/instructor at least once and 18% endorsed being bullied by a professor/instructor at least once. The findings also revealed a relationship between teacher bullying and professor/instructor bullying. Additional characteristics of student victims of teacher and professor/instructor bullying were explored; however, no significant differences were demonstrated between male and female students or between students with and without disabilities in their self-reported ratings of being bullied by teachers and professors/instructors. Finally, the psychometrics of a newly formed questionnaire addressing student perceptions of professor/instructor and teacher bullying were explored and established. Implications for universities and colleges are discussed and suggestions for future research are advanced.^

Metallic and ceramic thin film thermocouples

Ian M Tougas — Wed, 22 May 2013 16:07:29 PDT

Operating temperatures in the hot sections of modern gas turbine engines reach as high as 1500°C, making in situ monitoring of the severe temperature gradients on the surface of components rather difficult. Therefore, there is a need to develop thermocouples which can stably measure temperature in these harsh environments. Refractory metal and ceramic thin film thermocouples are well suited for this task since they have chemical and electrical stability at high temperatures in oxidizing atmospheres, they are compatible with thermal barrier coatings employed on engine components, have higher sensitivity than conventional wire thermocouples, and they are non-invasive to the engine environment. In this masters thesis, thin film combinatorial chemistry for materials discovery and characterization was the primary tool used to optimize thermo-element materials for thin film thermocouples. The resulting sensors based on ceramics, such as indium oxide and indium tin oxide, as well as others based on refractory metals, such as platinum and palladium, exhibited remarkable stability for many cycles at temperatures above 1000°C.^

Rhode Island aquaculturists' perceptions of eco-labeling certification programs

Nicole DeAngelis — Wed, 22 May 2013 16:07:28 PDT

Eco-labeling is a communication tool that allows producers to demonstrate to consumers that they comply with a set of environmental and social criteria by placing an eco-label on their product. Since global aquaculture production is increasing and bivalve mollusks comprise a large share of the world aquaculture production, eco-labeling certification has been suggested as a tool for creating a market for products that are produced with minimal negative environmental and social impacts. Because eco-labeling certification programs for bivalve aquaculture are currently voluntary in the United States, producers' opinions of these programs influence their current and future involvement in these programs. ^ Rhode Island (RI), where aquaculturists almost exclusively raise bivalves, provided a valuable case study for understanding aquaculturists' opinions of eco-labeling certification programs for shellfish aquaculture. The primary objective of this study was to investigate RI bivalve mollusk aquaculturists' perceptions of eco-labeling certification programs to explore the potential role of eco-labeling in RI aquaculture. To meet this objective, the study focused on four research areas to 1.) gather basic characteristics of RI aquaculture producers, farms and products; 2.) learn if RI aquaculturists participate or plan to participate in eco-labeling programs, and their perceptions of eco-labeling; 3.) discover perceived incentives and disincentives for participation in eco-labeling programs; and 4.) understand how RI aquaculturists feel about government regulations of aquaculture. To explore these research areas, the researcher interviewed twelve RI aquaculturists, in which participants were asked a combination of open- and closed-ended questions. Data in this study was summarized by descriptive statistics and open-ended questions were coded by themes that emerged. ^ Results showed that while nearly all respondents support eco-labeling programs, none of the respondents currently participate in eco-labeling certification programs, and only one aquaculturist plans to seek eco-labeling certification within the next five to ten years. This study found that most aquaculturists were unaware of the eco-labeling programs available for aquaculture and unsure about how they would choose between certification programs. Most aquaculturists would be more likely to certify their products with an eco-label if their competitors sought certification and most aquaculturists would be more likely to seek certification if they were involved in developing the certification standards. Obtaining a price premium from certification was the strongest incentive for participation in eco-labeling programs, while certification costs and additional recordkeeping required for certification were identified as the strongest disincentives. Management recommendations were provided for eco-labeling certification programs, aquaculturists, academics, and government regulators, as well as recommendations for future studies.^

Limited entry in Rhode Island: Tracing an idea from open access to license limitation to catch shares

Jonathon M Peros — Wed, 22 May 2013 16:07:26 PDT

For centuries fisheries institutions have shaped Rhode Island's storied fishing tradition, a hallmark of which has been access to marine resources by the residents of the state. In 2001, after a series of moratoriums on commercial fishing licenses, Rhode Island embarked on an extensive public process through the Coastal Institute at the University of Rhode Island to identify fishery management options based on the input of stakeholders. The outcome of that process was the passage of Senate Bill 2771 sub A—otherwise known as Rhode Island Gen. Law 20.2-1 (2002). The legislation ended a moratorium on the issuance of new commercial fishing licenses in the state, and called for the establishment of license limitation programs that accommodate new entry into state waters fisheries. In 2009, the state approved a catch share pilot program, effectively changing how access to the resource is constructed. ^ This research seeks to better understand the impetus for preserving access to the fishery in 2002, and determine if the catch share pilot program is consistent with the original intent of the Act. A Grounded Theory methodology is employed to illustrate the entire management situation leading up to the passage of Rhode Island Gen. Law 20.2-1 (2002). The results of this research indicate that while access has not been functionally compromised for new entrants through the enactment of a sector pilot program, a normative and cognitive disconnect exists between the intent of the legislation and the catch share pilot program. Moreover, the values and worldviews of fisheries stakeholders in Rhode Island are influenced by a range of regional and international institutions that did not inform the 2002 legislation.^

False ring formation in eastern hemlock (Tsuga canadensis) after hemlock woolly adelgid (Adelges tsugae) and elongate hemlock scale (Fiorinia externa) feeding

Liahna Gonda-King — Wed, 22 May 2013 16:07:26 PDT

Hemlock forests in the eastern United States are threatened by two sessile invasive herbivores: the elongate hemlock scale, Fiorinia externa Ferris (Hemiptera: Diaspididae; 'EHS') and the hemlock woolly adelgid Adelges tsugae Annand (Hemiptera: Adelgidae; 'HWA'). EHS and HWA occupy similar feeding guilds but have enormously different effects on tree health. EHS reduces hemlock growth and causes needle discoloration and loss, but only causes tree mortality under high EHS densities. In contrast, HWA has devastated stands of hemlocks on the east coast of the United States. Although EHS reduces fitness of the tree and can kill already stressed trees, HWA is known to kill hemlocks in as few as four years. The mechanism by which HWA and EHS kill trees is not yet elucidated and little is known as to the physiological effects each invasive has on hemlock. For the first part of my master's research, I focused on differences in abnormal wood production among uninfested trees, EHS-infested trees and HWA-infested trees at the branch level. Specifically, I measured false ring density, ring growth and earlywood:latewood ratios in the two most recently deposited growth rings. Branches from HWA-infested trees had 30% more false ring than branches from EHS-infested trees and 50% more than branches from uninfested trees. In contrast, growth and earlywood:latewood ratios did not differ among treatments. This result suggests that two invasive insects from similar feeding guilds have differing effects on false ring formation in eastern hemlock. These false rings may be the product of a systemic plant hypersensitive response to feeding by HWA on hemlock braches. If false rings are responsible for or symptomatic of hemlock water stress, this may provide a potential explanation for the relatively large effect of HWA infestations on tree health. ^ For the second part of my master's thesis I looked at the impact of HWA on eastern hemlock anatomy and physiology. Specifically, I looked at growth and production of new buds on terminal and side branches in hemlock infested with and without HWA. We found that trees infested with HWA have significantly less new growth and fewer new buds. Additionally, I measured water potential, photosynthesis and stomatal conductance in trees infested with and without HWA during diapause and immediately after HWA resumes feeding. HWA undergoes summer diapause while still attached to eastern hemlock and it is unknown if this 'inactive' period affects tree health. We found that actively feeding HWA exacerbate reductions in photosynthesis and stomatal conductance, but not water potential. The presence of HWA, irrespective of feeding activity, decreases eastern hemlock water potential, photosynthesis, and stomatal conductance. Additionally, water potential and stomatal conductance were negatively correlated with HWA density. These data indicate that HWA negatively impacts tree health even when not actively feeding and depleting carbon reserves. These results also suggest that HWA-infested trees are water stressed, shedding light on possible mechanisms behind HWA-induced death.^

Developing a method for enhanced explosive detection by Surface Enhanced Raman Scattering (SERS) and Metal Enhanced Fluorescence (MEF)

Meredith A Matoian — Wed, 22 May 2013 16:07:25 PDT

The first manuscript, "Fabrication of SERS Substrates for Explosive Detection," focuses on the development of a Surface Enhanced Raman Scattering (SERS) substrate for use in the area of explosive detection. The substrate was created by immersion plating of silver onto porous silicon, resulting in a Ag roughened surface with an average roughness of 135 nm as determined by AFM. When explosive solutions, such as trinitrotoluene (TNT) and dinitrotoluene (DNT) in ethanol, were applied directly to the substrate, detection of unique Raman bands was possible down to the 10^-9 − 10^-10 mol/cm² range. These results prove the technique is selective and shows promise for future work when vapor phase explosives will be investigated. ^ The second manuscript entitled "Light Trapping to Amplify Metal Enhanced Fluorescence with Application for Sensing TNT" focuses on the use of the previously mentioned substrate for Metal Enhanced Fluorescence (MEF). By using a polymer layer as a dielectric spacer in between the Ag layer and the fluorophore, enhancement of fluorescent emission was possible even though the spacer thicknesses was 10–20 times larger than typically reported. In experiments with rhodamine 6G, the fully assembled substrate resulted in a 1600-fold enhancement of emission. Compared to the usually reported 10¹ − 10² times enhancement, the large enhancement is suspected to occur due to numerous effects. As enhancements were observed with and without the roughened Ag layer, light trapping is suggested as a contributing factor in addition to MEF. While less effective in enhancing the emission of the conjugated polymer methoxy-ethylhexloxypolyphenylene-vinylene (MEH-PPV) that is known to interact with TNT vapor, the quench in fluorescent emission of MEH-PPV occurred more rapidly when the light trapping polymer was incorporated. Rapid detection and increased sensitivity are important features to the detection of trace explosives.^

Assessment of housing density impacts on groundwater quality: Integration of water quality data into a GIS-based model for estimating groundwater nitrate concentrations

Jessica L Donohue — Wed, 22 May 2013 16:07:24 PDT

Groundwater is the sole source of drinking water in the coastal community on the Quonochontaug headland in Charlestown, Rhode Island. Management and preservation of this water resource and the surrounding coastal ponds is of increasing importance as population increases and seasonal homes are converted to year-round residences. One of the main issues facing this groundwater system, addressed in this study, is the pollution of groundwater and the coastal salt ponds from anthropogenic sources of nitrate. Water samples were collected from 47 private wells, including shallow wells constructed in the stratified glacial material and deep wells drilled into the underlying fractured granitic bedrock. The sampling locations allow for analysis of spatial and depth related trends in water chemistry. This area has many seasonal residents, resulting in greater stress on the groundwater system in the summer. In order to evaluate temporal trends, samples were collected in three rounds; early summer, late summer, and fall. Nitrate concentrations were above background levels (0-1 mg/L NO₃-N) in 92% of samples collected, and 27% of samples reached 5 mg/L, indicating anthropogenic impact from septic systems, cesspools and fertilizers. The overall distribution of nitrate remained consistent throughout the three sampling rounds, indicating no temporal trend. Data analysis revealed a strong association between housing density and observed nitrate concentrations. This positive correlation was used to develop a GIS-based model for predicting nitrate concentrations throughout the salt pond region using current housing densities. The resulting model provides a management tool that can be used for targeting areas of concern and to better constrain the magnitude of groundwater-derived nitrogen loading to the nearby salt ponds. ^

Experimental and numerical study of a wave energy harvesting buoy

John Montgomery — Wed, 22 May 2013 16:07:23 PDT

Since 2006, as part of projects funded by the Office of Naval Research (SBIRs and STTRs) and the State of Rhode Island (STAC, RI Alliance), the Department of Ocean Engineering at the University of Rhode Island (OCE) and Electro Standard Laboratories (ESL) have worked on the design, modeling (both computer and laboratory), construction, and testing of a series of small point absorber, multi-directional buoys for wave energy conversion. At full scale, these systems target up to 1kW of power per unit, mostly to power ocean instrumentation systems. Initially 4 design concepts were proposed. From these, two design concepts were selected for further examination. Design concept 2 (DC2) has a spherical float, to which a cylindrical canister is rigidly attached, and which houses a Linear Electric Generator (LEG; made of a permanent magnet, suspended to a spring, oscillating within a (two-phase) coil). A rod, attached to the generator's magnetic armature, exits through the bottom of the canister and connects to a resistance platform. Differential movement between the float and the platform drives the generator oscillations. Design concept 3 (DC3) is comprised of a self-contained resonating multiple-spar buoy. A long central spar contains an LEG and is surrounded by four shallower satellite spars (satellite spars reduce draft, increase stability and help achieve proper resonance characteristics). The LEG has a large ballast attached to its bottom which oscillates as a result of buoy heave through coupled resonance. Hence, LEG oscillations are maximized by matching buoy heave and LEG natural periods to the targeted sea state peak spectral period. Successful prototype testing at the 1:10 scale (in the URI-OCE wavetank) and the 1:4 scale (in field tests performed in Narragansett Bay) have been performed for both buoys. These scale model experiments are used to calibrate parameters of a pre-existing numerical model (viscous drag coefficients) and select buoy characteristics to maximize energy production.^

On performance of GPU and DSP architectures for computationally intensive applications

John Faella — Wed, 22 May 2013 16:07:23 PDT

This thesis focuses on the implementations of a support vector machine (SVM) algorithm on digital signal processor (DSP), graphics processor unit (GPU), and a common Intel i7 core architecture. The purpose of this work is to identify which of the three is most suitable for SVM implementation. The performance is measured by looking at the time required by each of the architectures per prediction. This work also provides an analysis of possible alternatives to existing implementations of computationally intensive algorithms, such as SVM. Some performance improving methods were proposed and examined for the given DSP and GPU architectures. ^ The 4-class and 7-class implementations of the SVM algorithm were examined. On the system with an Intel i7-2720QM CPU at 2.2GHz, the execution times on a per prediction basis were 364µs for the 4-class implementation, and 410µs for the 7-class implementation. ^ On the Spectrum Digital TMS320C6713 DSP development board at 225MHz, the 4-class SVM implementation uses 125ms and the 7-class version needs 165ms. After careful examination of the DSP architecture, the following are implemented to improve the performance: (1) number of memory accesses is greatly reduced via programming technique, (2) the L2 cache is better utilized, and (3) the number of branch statements is reduced. As a result, the run time for 4-class SVM is improved from125ms to only 9ms, and from 165ms to 11ms for the 7-class implementation. ^ On the Nvidia Geforce GT 540m graphics card at 1334MHz, the 4-class SVM needs 798µs, and the 7-class implementation requires 845µs. Again, the GPU's architecture is investigated and the following are used to improve the performance: (1) eliminating excessive memory accesses, (2) taking advantage of memory coalescing, and (3) the use of the reduction method. The improvements resulted in a decrease in the execution time from 798µs to 175µs for the 4-class SVM implementation and from 845µs to 200µs for the 7-class implementation. ^ Because the three architectures studied here are incorporated in three very different systems, running at different clock speeds, a direct comparison of the run time is not possible. The DSP system runs at roughly 10 times slower clock speed than the Intel i7 core system, and achieved more than 20 times slower run times. We cannot directly extrapolate this result; however, we observed that DSP does have its drawbacks when implementing the SVM algorithm. The DSP processor was designed specifically to support computationally intensive DSP algorithms. However, SVM algorithm is somewhat different from traditional DSP algorithms and thus some DSP architectural features are not applicable. ^ From the experimental results, we may observe that GPU is most suitable for the SVM algorithm. Even though it runs at a lower clock speed, about 60% of that of Intel i7 core, with the performance improvement techniques, the GPU outperforms the i7 counterpart. This may be attributed to the GPU's architectural support for parallel computations and its flexibility to adapt to various computationally intensive algorithms.^

Generating recombinant antibody fragments to potential immunogenic biomarkers in the salivary gland homogenate of Ixodes scapularis

Bradford Christopher Lefoley — Wed, 22 May 2013 16:07:22 PDT

Arthropods serving as a major vector of disease are common throughout the world and are responsible for the transmission of several potentially serious pathogens. Existing diagnostic methods are not always the most accurate ways to identify the most at risk populations, leading to a misallocation of resources and potentially false diagnoses. This problem is especially critical in the developed world where proper medical resources are lacking and populations may be rural, leading to the need for developing a methodology implicating biomarkers of exposure to these organisms. Through this approach a mating is needed between existing entomological methods and modern biotechnology. Antibody phage display, a high-throughput method proven extremely reliable and versatile, is the technique of choice for isolating these potential biomarkers and developing them into a technology meeting clinical needs. In this study, several recombinant antibody libraries were constructed and screened again the salivary gland homogenates of the tick species Ixodes scapularis. Although recombinant antibody fragments were isolated, they were not verifiable. This study explains these results, highlighting several of the challenges involved in adapting antibody phage display for this new methodology and providing a plan of development to bring such a model into standards acceptable to clinical applications using the libraries previously constructed.^

Relationship violence and suicidality among high school students

Stephanie L Joyal — Wed, 22 May 2013 16:07:21 PDT

Youth involved in relationship violence are at a higher risk for negative outcomes such as behavior problems and suicidal tendencies than those who have not experienced such violence. Through examination of data from the National Youth Risk Behavior Survey, using cross tabulation statistics and logistic regression analysis, this study investigated the association between relationship violence and suicidality, controlling for demographic characteristics of the participants. The sample was made up of a nationally representative group of 16,410 students in grades 9-12. Of the population surveyed (n=16,410), 9.7% reported physical dating violence and 10.9% had been in a physical fight at school. These students showed significantly higher rates of reported suicidality. Of those reporting dating violence, significantly more students reported suicidality (34%) than those who did not report dating violence (15.3%). Among youth who had fought in school, 29.7% showed suicidality, compared to 15.4% of participants who had not been in a fight. With respect to demographics, it was found that females (20.6%) were more likely to report suicidality than boys (13.6%) were. In addition, findings differed between races with the lowest rate (16.1%) among white subjects. Variation in suicidality was present among grade levels with twelfth graders reporting the lowest rate (14.8%). After controlling for sex, grade level, and race, both dating violence and fighting in school were significantly associated with reported suicidality. Physical violence from a boyfriend/girlfriend correlated more strongly with suicidality (OR, 2.9; 95% CI, 2.5-3.2, p < .01), than did physical fighting in school (OR=2.3; 95% CI, 2.0-2.6, p < .01). For those students who reported involvement in both dating violence and fighting in school in the previous 12 months, suicidality rates were significantly higher (50.6%) than students who reported only one type of relationship violence (26%).^

Designing effective messages for increasing readiness to use alternative transportation

Jonathan M Drew — Wed, 22 May 2013 16:07:20 PDT

The use of single-occupancy vehicles (SOVs) has had a profound impact on human health and the environment. In order to change the impact our travel behavior has on both the environment and our health, change needs to occur at an individual level. The purpose of this study was to determine effective framing strategies that will encourage individuals to use alternative, or sustainable transportation (ST), i.e. commuting by means other than SOV, and to compare the efficacy of this intervention to that of a "green" eating (GE) intervention. Using the Transtheoretical model (TTM) and its key constructs, self-efficacy and decisional balance, data were collected from 134 undergraduate students at the University of Rhode Island measuring their attitudes towards ST and GE, respectively. The intervention consisted of a pretest survey, four educational modules, tailored messaging and finally, a posttest. Data from the pretest survey contained each participant's Stage of Change reflecting attitudes toward ST and GE. After the pretest, participants were randomized into the GE group or the ST group. Participants in the GE and ST groups received educational modules over the course of three weeks. Between each educational module, participants received motivational messages tailored to their respective stage, as determined in the pretest. Results from tests revealed that there were small positive shifts in stages in each of the treatment groups as well as small increases in decisional balance and self-efficacy as a result of the ST intervention.^

Pseudocalanus copepods in the Bering Sea: Species identification, intraspecific diversity and biogeography

Jennifer Bailey — Wed, 22 May 2013 16:07:20 PDT

The calanoid copepod genus, Pseudocalanus, is an important secondary producer and widespread throughout the northern hemisphere. While ecologically important, previous work with this genus has been limited due to difficulties in morphometric identification. Here, Pseudocalanus species composition and distribution were examined in the Bering Sea through sequencing of the mitochondrial CO1 gene of 642 individuals from 10 locations. Phylogentic trees of inter- and intra specific diversity demonstrated that in the spring of 2010 (March-June), four species of Pseudocalanus co-existed at various locations across the shelf. Species composition in the middle shelf (50-100 m depth) was significantly different from composition on outer shelf/slope (≥200 m depth). Correlation of species composition with salinity and the chlorophyll maximum depth indicated that environmental factors influence distribution and highlighted the importance of species-specific approaches to ecological research involving the Pseudocalanus genus. Differences between the middle shelf and outer shelf/slope populations extended to the intraspecific level in two of the four species. Although high haplotypic diversity was observed in all Pseudocalanus spp., a weak structure between the middle shelf domain and offshore stations was seen only in P. acuspes and P. minutus. This indicates that while there may currently or previously been some barriers, gene flow is possible across the shelf. Evidence of mixed intraspecific and divided interspecific variations, in addition to correlation with environmental conditions, highlighted the importance of a species-specific approach to future research of this genus and will assist in creating greater accuracy in the modeling of an ecosystem-wide response to climate change. ^

First principles, unstructured, dynamic model for regulating CO2 and pH in bicarbonate buffered perfusion bioreactor

Ashish Gaurav Airan — Wed, 22 May 2013 16:07:19 PDT

Since its inception, the biotechnology industry has faced the problem of pH control and CO₂ management. This research paper explores the challenges of developing a first principles, unstructured, dynamic, nonlinear mathematical model to maintain pH and control carbon dioxide levels in an aerobic Chinese hamster ovary (CHO) cell culture in a perfusion bioreactor. Perfusion bioreactor is an extremely complex bioreactor to model because the cells grow in a quasi-steady state system. Cell growth, feed, substrate consumption, by-product formation and product formation are all time dependent, equations for which can only be solved through numerical methods. Added complexity comes from presence of stiffness in solving the non-linear equations due to the different time scale of each set of equations. Equations related to pH that involve acid/base ionization have reaction rates on the order of nano- or pico-seconds. CO₂ or O₂ hydration and bubble dynamics involve the reaction rates on the order of seconds and cell growth equations are on the order of days. This research paper also presents a framework for software development to solve these equations without conducting experiments, except as a final trial before using the results of the model on the manufacturing floor.^

Feasibility and optimization of small-scale, clay-lined water retention structures in Kenya's lake region

Joseph Dumont — Wed, 22 May 2013 16:07:18 PDT

Earthen-built retention ponds lined with local clays are a promising technology for providing accessible water security to subsistence farmers in Kenya's lake region. Combining data collected during a field campaign, laboratory results, previous multidisciplinary research and theoretical values, parameters of a local water budget were determined. The budget approximates the water available in storage by the summation of the following inputs and losses: stored rainfall runoff, direct precipitation, evaporative loss, seepage loss in the retention pond, and the volume of water removed for amaranth irrigation. A new method was developed to estimate clay-liner compaction through walking or stomping for the purpose of measuring permeability ranges in the laboratory. Numerical simulations were used to identify ranges of likely conditions where the retention ponds performed favorably. Simulations demonstrate the feasibility of successful field scale tests, and demonstrate numerical approaches to optimizing the sizing of these ponds for local conditions and clay performance.^ These simulations indicated that in about 9 out of 10 years growing amaranth between the long and short rains—June through September—supplemental irrigation will be required to meet estimates for high crop yields. Achieving a liner hydraulic conductivity less than 1e-8 cm/s exceeds minimum irrigation requirements for all simulated environmental and climate scenarios, for plots with 15 % of the farmland (0.4–1 ha) devoted to a retention pond, and supporting half the remaining arable land for rotation.^ The ability to extend the growing season, leverage drier-than-normal rainy seasons or add new harvests into the year supports local socioeconomic development through food security, improved health and increased economic power. This approach has the potential to be applied regionally at low risk and with little investment.^

Evaluating ocean model resolution and initialization under hurricane conditions

Melissa R. S Kaufman — Wed, 22 May 2013 16:07:17 PDT

Although hurricane models can now more accurately forecast storm track, they have not made significant improvement in forecasting hurricane intensity. Sea surface temperature and ocean heat content play an important role in regulating tropical cyclone intensity. The focus of this chapter is on ocean model resolution. The Princeton Ocean Model (POM) is used to calculate the temperature fields under a specified hurricane wind stress, utilizing an idealized storm structure. ^ This study examines ocean model response under idealized hurricane conditions for a range of horizontal resolutions spanning from ½° to 1/18°. Resolution sensitivity was examined for different storm speeds, different storm sizes, different model physics (3D or 1D) and different initial ocean conditions. The higher resolution experiments better represent the structure of the hurricane eye and the eyewall. It is found that the magnitude of sea surface temperature (SST) in the cold wake is less at coarser resolutions than at finer resolutions. Horizontal resolution is more important in experiments with 3D physics than 1D physics. Horizontal resolution has a larger impact in resolving slower moving storms than faster moving storms. Latent heat flux is also generally larger at higher resolutions than coarser resolutions. The values of SST, latent heat flux, and turbulent kinetic energy (TKE) converge in experiments with 1/12° and 1/18° grid spacing. Ocean heat uptake (OHU) increases as resolution increases. Vertical resolution also plays an important role in ocean heat loss and uptake estimations. Vertical grid spacing of at least 5 m in the mixed layer and at least 10 m in the upper thermocline are necessary for accurate calculations of ocean heat loss and uptake.^

Continuous multi-sensor data registration for an enhanced driver vision system

Xiaolong Zheng — Wed, 22 May 2013 16:07:17 PDT

This thesis is concerned with the registration in space and time of data from a radar system and a visible-range camera. Typical ground objects are buildings, trees and concrete road. The objects are placed in natural or urban areas where the background is unstructured and complex. The performance of enhanced vision systems is analyzed, to achieve models of the uncertainties in radar data.^ A registration method is presented. It handles general, noisy 3D point cloud data. The approach is based on the fact that man-made objects on a large scale can be considered be of rectangular shape or can be decomposed to a set of rectangles. This method falls within the iterative closest point framework. Registration when several similar models are available is discussed.^ The system covers the process from sensor data to the user interface, i.e., from low level image processing to high level situation analysis. In registration based on radar data, the range values accuracy is important. A time-of-flight estimation algorithms are analyzed: peak detection.^ The performance of a tool for synthetic generation of scanning radar data is evaluated. In the measurement system model, it is possible to add several design parameters, which makes it possible to test an estimation scheme under different types of system design (simulation data or Kinect data).^

The indirect effect of earthworms on methane flux in two temperate pasture soils

Edward J Avizinis — Wed, 22 May 2013 16:07:16 PDT

Methane, a potent greenhouse gas, is produced or consumed by microorganisms in soil, depending on soil conditions. In general, anaerobic conditions promote activity of methanogenic Archaea, whereas aerobic conditions promote methane consumption by methanotrophic bacteria. Earthworms may have an effect on methane flux in soil by altering soil pore space, aeration, moisture content, and organic carbon availability, all of which affect the activities of methanogens and methanotrophs. As the range of European and Asian earthworm species expands throughout the United States, their potential effects on methane flux may have global implications. ^ My research focused on the effects of earthworms on methane flux in temperate pastures and on the potential mechanisms involved. In November, 2009, I established 24 experimental plots each at Peckham Farm (PF), Kingston, and at the W. Alton Jones (WAJ) campus of the University of Rhode Island, West Greenwich, both in southern Rhode Island. Three treatments (n=8) were implemented: (i) earthworms removed (D−), (ii) earthworms removed, counted and returned to the plot (D+), and (iii) undisturbed (U). Weekly methane flux measurements were made from April to November, 2010. Soil moisture and temperature were continually recorded. Methane flux measurements were also made three times over a 24-h period at each site to quantify diurnal patterns. I also conducted a second experiment to examine the relationship between earthworm population size and soil properties, and methane flux that did not disturb the soil. I determined methane flux in these supplemental plots at seven randomly selected locations in an area of the field adjacent to the manipulated plot experiment. Once gas sampling was completed, I sampled the soil under each chamber for pH, organic matter content, NH₄ and NO₃ concentrations, soil moisture, and soil temperature. Earthworms were counted, weighed and identified. ^ I also examined the potential effects of earthworms on acetoclastic and hydrogenotrophic methanogenesis, and on methane oxidation, using cast, burrow, and bulk soil from soils inoculated with Anecic and epi-endogeic earthworms, the two most common earthworm ecological groups found at the research sites, and a control soil. Soil from bulk, burrow or casts was transferred to microcosms with conditions manipulated to favor only one of the three processes—methane oxidation, hydrogenotrophic methanogenesis, or acetoclastic methanogenesis. Microcosms were periodically sampled for methane concentration in the headspace to determine process rates. ^ In the manipulated plots field experiment the majority of the differences were found at the W. Alton Jones site. This is in agreement with the results of the microcosm experiments, which suggest that earthworms may affect methane flux specifically by increasing acetoclastic methanogenesis and decreasing oxidation, and that effects may be site-specific. At PF, the decrease in methane oxidation as found in the anecic casts treatment in the microcosms may have occurred in the field but to a minimal degree, that which was not enough to cause a measurable difference. However, at WAJ, the combination of lower methane oxidation in anecic cast soil, paired with an increased acetoclastic methanogenesis in the epi-endogeic burrow soil, may drive differences in flux. (Abstract shortened by UMI.)^

The hydrodynamic optimization of a cable-flying vehicle

Brian Amaral — Wed, 22 May 2013 16:07:15 PDT

Profiling the water column with high vertical and horizontal resolution in the deep ocean from a moving vessel is difficult with the current tools. Thus, a new wire-flying vehicle capable of higher resolution, called the WiFly, is being designed. The WiFly will profile the water column as it traverses up and down a ship-towed cable. Wings protruding from the sides of the vehicle body generate vertical lift which will propel it through the water. A control algorithm will alter the angle of attack of the wings and allow the vehicle to travel over a range of speeds and operational depths. ^ The goal of this thesis was to perform a design evaluation of the WiFly vehicle to optimize its profiling performance. The design was optimized by maximizing the potential wing lift and minimizing the vehicle drag in the direction of the most common incident flow angles while maintaining manufacturability and practical size constraints. The vehicle’s performance was measured by evaluating its feasible glide slopes (GSs) which are defined by the ratio of vertical to horizontal velocity along the cable. ^ The project was broken into three sections. First, the velocity and angle of common incident flows on the vehicle were determined through Simulink modeling. Second, the body and wings of the vehicle were designed to house all of the necessary components using computer aided design (CAD) and assessed in FlowSimulation for drag forces. Finally, the vehicle was evaluated in a performance simulation via its GSs. The second and third steps were iterated until an optimum vehicle design was reached. ^ The vehicle was numerically represented in the performance simulation by a set of parameters including the vehicle’s drag coefficients and projected cross-sectional areas. These parameters changed respective to the incident flow angle, surface area of the wings, various wing lift-to-drag ratios (LDRs), and the wings’ lift coefficient. The simulated drag and lift coefficients for both the body and wings were generated using FlowSimulation. By iterating between the performance simulation of the vehicle and its design, the vehicle’s design could be refined. ^ The final body design of the vehicle had the profile of a National Advisory Committee for Aeronautics (NACA) 0025, with a bulbous top and a curved trailing edge. It was approximately 0.9m in height, 1.5m in length, and 0.25m in width. The drag coefficients ranged from 0.023 to 0.085, over the range of incident flow angles. The wings were designed using a modified NACA 0018 profile with an aspect ratio of 3 and a combined lifting surface area of approximately 0.2m². The wing measured approximately 56cm in span and 20cm at the root chord. ^ The combination of the final body and wing design produced GSs from 3.75 to 5.2 between cable angles of 0 and 30 degrees. Glide slopes of this magnitude are significantly higher than the current water profiling tools as well as the initial goal of 1.0 for this project. This will lead to drastically improved efficiency in ocean water column profiling. ^

The effects of whey and soy protein supplementation on appetite and dietary quality in overweight and obese college-aged individuals

Kerri L Alexander — Wed, 22 May 2013 16:07:14 PDT

Background: Over one-third of the United States population is obese. Obesity is a complicated disorder associated with many chronic diseases such as coronary artery disease, diabetes, hypertension and stroke. Many college students are overweight or obese, which may be due to lack of physical activity and unhealthy diets. Both dietary quality and satiety are important factors that may help modify obesity and associated health conditions. The impact of various interventions on these factors has not been clarified. Protein supplementation may be able to improve satiety, but research regarding improvement in diet quality in relation to this supplementation is limited. ^ Objective: To determine the impact of an 8-week protein supplementation intervention on dietary quality and appetite by comparing groups supplemented with whey or soy protein with each other and with an assessment only control group. ^ Methods: In a randomized, control trial with pre-post testing, subjects were randomized to one of three groups, whey protein, soy protein or non-treatment control. Experimental group subjects participated in 8 weeks of protein supplementation, and the control group received no treatment. Dietary quality and appetite were assessed at week 0 and week 8. The primary dietary quality outcome was total Alternate Healthy Eating Index (AHEI) score. The primary appetite outcomes were lab-assessed fasting hunger and satiety. Subjects assigned to the supplement groups were asked to ingest either the whey or the soy protein supplement, providing 21.5 grams of protein per day, on a daily basis for 8-weeks. All laboratory visits were conducted at the University of Rhode Island. Analysis of variance was used to compare within-group and between-group differences in dietary quality and satiety for pre and post measurements. ^ Participants: Nine overweight and obese students (three per group) were recruited from the University of Rhode Island and surrounding areas through classroom announcements, fliers and mass emails. ^ Results: There were no significant differences between the groups at baseline, although, based on the visual analog scales, the control group tended to have higher fasting hunger levels (control: 54.1±27.7mm, experimental: 35.5±26.1mm) and lower fasting satiety levels (control: 35.5±19.3mm, experimental: 56.0±26.5mm). The control group also had lower energy intake (control: 2428.4±1266.9kcal, experimental: 2838.3±1182.5kcal) and lower protein intake (control: 77.3±13.3g, experimental: 99.3±24.4g) based on three day food diaries, as well as higher diet quality (control: 44.0±6.6, experimental: 35.7±6.5) based on the total AHEI scores. No significant time by group or within group differences were found for AHEI scores or visual analog scales for hunger, satiety or appetite. During supplementation, the experimental groups consumed significantly more protein than the control group (experimental: 115.3±25.5 grams, control: 73.7±10.6grams, p=.033). Measures of satiety and hunger were not significantly impacted by the intervention. ^ Conclusion: The addition of a protein supplement to the diet of overweight and obese young adults, with dietary counseling incorporated, did not improve diet quality or suppress fasting appetite. With a larger sample size, the effectiveness of this intervention may be measureable. Overall, this research gathered valuable information for use in interventions in the future. ^

A geophysical investigation of seafloor morphology and sediment dynamics on the Crimean Shelf: Implications on the early Holocene Black Sea inundation

Daniel P Whitesell — Wed, 22 May 2013 16:07:14 PDT

The transition of the Black Sea basin, from a lacustrine to a marine environment, has been accredited to either a catastrophic or an oscillatory inundation of Mediterranean seawater. The oscillatory interpretation is supported by seismic data that exhibits multiple transgression and regression events and a persistent outflow during the Holocene. Evidence supporting a catastrophic event is interpreted from a uniform, Holocene mud drape, truncated regression and preserved paleoshorelines seen in seismic data. We present the results of two geophysical surveys conducted along the Crimean Shelf in the northern Black Sea in 2006 and 2008, aboard the R/V Endeavor and the USNS Pathfinder. Using our seismic data processing model as a template, the data from these surveys were compared to previous research to further investigate the early Holocene flood and Crimean shelf sediment dynamics. Features such as a ubiquitous mud drape layer, paleoriver channels, truncated regression, bedforms and hummocks were identified in our seismic sections. Some of these features correspond to previous seismic data supporting the catastrophic model but no evidence of features supporting an oscillatory flood was recognized in either survey. Supplemental side-scan imagery and bathymetry data revealed a dynamic shelf including mass slumping, a hummocky channel system and shelf failure. While initial seismic evidence appears to indicate a catastrophic inundation, the presence of large-scale, active sediment transport, may signify that further features supporting either model no longer exist on the Crimean shelf. ^

An alternative to chromates using the titanate ion

Andrew Pierce — Wed, 22 May 2013 16:07:13 PDT

Chromate conversion coatings have been the most widely used technique to enhance the corrosion resistance of aluminum alloys. However, concerns over the highly toxic and carcinogenic nature of the hexavalent chromium ion have cast serious doubts on the future use of these coatings. The Department of Defense and industry is in the process of attempting to replace chromates, but has yet to find an alternative as inexpensive, easy to use, and most importantly as effective as chromates. ^ A potential replacement for chromate coating is a coating based on the titanate ion. Elemental titanium possesses a number of similarities to elemental chromium in that both have multiple valence states, good passive layer formation, and a low passivation potential; making it an ideal candidate for the titanate ion to replace the chromate ion. The similarity in the passive regions for chromium and titanium can be seen in their Pourbaix diagrams. For a different aluminum alloy, 2024-T3, titanate replacement of chromate has been shown to be effective. ^ This process has failed to be applied successfully to Al 6061-T6 and Al 7075-T6 in previous attempts. The main cause suspected for coating failure was the formation of fluoride precipitates. In an attempt to address the precipitation problem a post conversion treatment was added and the influence of rinse duration after conversion coating was examined. ^ For this study, on Al 6061-T6 successful coatings could be applied with the introducing of a post treatment step which not only imparted titanium on the surface but also significantly thickened the aluminum oxide layer. Whether this coating can be considered a conversion coating or a sealed anodized coating is unclear at present, however it is clear that the coating provides long duration protection from salt water and also includes a mechanism which allows for continued reactivity. The most likely cause for this reactivity is inclusion of titanate in the coating. Attempts to coat Al 7075-T6 were not successful and it is most likely due to cracking of the coatings formed. ^

The effect of goal setting on fruit and vegetable consumption and physical activity level in a web-based intervention

Stephanie O'Donnell — Wed, 22 May 2013 16:07:12 PDT

Background: Most people do not meet the recommendations for fruit and vegetable consumption and physical activity. Goal setting has been shown to increase health related behaviors such as these, but there has not been extensive research. ^ Objective: The purpose of this study was to further explore the relationship between goal setting and fruit and vegetable consumption and physical activity to see if it could have a positive impact as part of a web-based intervention for young adults. ^ Design: This study has a prospective, descriptive design. It is a secondary analysis of data from a previous research study with an experimental design. The intervention included ten online lessons that provided information about fruit and vegetable consumption and physical activity. ^ Participants/Setting: Participants were from the experimental group of the original study (n=830). The study took place at 8 universities across the nation. Participants were 18 to 24 years (19.16 ± 1.15), mostly female (64%) and mostly white (79%). ^ Main outcome measures: Intake of fruits and vegetables and physical activity completed were reported weekly along with weekly goal setting. ^ Statistical analyses performed: ANOVAs were used to determine effects of time. Paired t-tests were used to explore the relationship between goals set and actual fruit and vegetable intake and physical activity done. Goal attainment score was calculated and summation was used to determine goal group. ANCOVA was used to look at group effect. Chi squared was used to look at the association between group and whether or not participants met recommendations at the end of the intervention. ^ Results: There was a significant effect of goal setting on both fruit and vegetable consumption and physical activity. The effect was seen more clearly with fruit and vegetable consumption as the difference between goal and intake decreased over time, the correlation grew stronger, and the percent of subjects meeting or exceeding goals and percent of subjects meeting recommendations increased over time. For physical activity, the difference and correlation between goal and activity done remained consistent throughout, and the percent of subjects meeting or exceeding goals decreased over time with no significant change in percent of subjects meeting recommendations. There was a significant effect of goal group for both behaviors, which was again seen more clearly with fruit and vegetable consumption. ^ Conclusions: Goal setting as part of a web-based intervention was effective in increasing fruit and vegetable consumption among young adults. While this study did show a significant effect of goal setting on physical activity level, it did not show increases in physical activity level. Perhaps goal setting needs to look different when exploring its relationship to maintain versus change a behavior. There is a need for further research in this area, particularly with more reliable measures of intake and activity.^

Psychosocial predictors of HPV vaccination among college women

Savannah Frazier — Wed, 22 May 2013 16:07:11 PDT

Human Papillomavirus (HPV) is the most common sexually transmitted infection in the U.S. Several studies have looked at predictors of HPV vaccination among women, yet many of these studies have described static variables that provide limited insight into creating interventions to increase vaccine adoption. To address this limitation the present study used multiple variables drawn from behavioral change theories to identify predictors of HPV vaccine completion in 215 college women. Participants completed measures based on the transtheoretcial model (decisional balance for HPV vaccination, self-efficacy for HPV vaccination, and an HPV knowledge scale), and the Multidimensional Health Locus of Control Scale (MHLC). These variables were used to predict the likelihood of falling into one of the two categories (vaccinated vs. unvaccinated). The vaccinated group was defined as having completed all three Gardasil^® shots. The mean age was 18.89 (SD=1.09), 84.7% were Caucasian, 91.6% were heterosexual, 74% had mothers that had completed at least some college, and 74.9% had completed all three Gardasil® shots. No significant differences in vaccine completion rate were found based on race/ethnicity or socioeconomic status. However, white women scored significantly higher on knowledge of HPV then their non-white peers, suggesting a disparity in the dissemination of HPV information. Logistic Regressions assessed the impact of predictor variables on the likelihood of vaccine series completion. Variables based on the transtheoretical model accounted for a significant proportion of variance in completion rate. Pros for vaccination was found to be the strongest predictor of vaccine completion. The findings indicate that the women reporting higher pros for vaccination were 13% more likely to have completed the Gardasil® series for each one unit increase the had in pros. These findings may inform future TTM-tailored interventions aimed at increasing HPV vaccine uptake among college women by focusing on increasing their perceived pros for vaccination.^

Locus of control, decision making, and economic stress

Stephen Favasuli — Wed, 22 May 2013 16:07:10 PDT

Economic stress is associated with a number of adverse psychological, academic and health outcomes. This study investigated the relationship between locus of control and decision making styles in accounting for variation in economic stress among low-income participants. Mothers of preschool children attending day care centers in low income areas completed surveys on locus of control, five decision making styles, and economic stress. It was hypothesized that more internal locus of control would be related to lower levels of economic stress and that the relation between stress and locus of control would be mediated by decision making styles, with dependent and avoidant styles being associated with more economic stress than rational and intuitive decision making styles. ^ As expected, a more external locus of control was associated with more economic stress as compared to more internal locus of control. There was no association between any decision making styles with locus of control or economic stress and no support for the hypothesis of decision making style as a mediator of this relationship. Results suggest that at times, perceived control over one's economic situation can be predictive of decreased economic stress among a generally low income population. Future research should address whether it may be possible to address economic stress and the detrimental effects it can have through policies that empower individuals to take control over their economic situations, even independent of income.^

The effects of whey and soy supplementation on flow-mediated dilation of the brachial artery

Jonathan Conca-Petit — Wed, 22 May 2013 16:07:09 PDT

Heart disease is a serious problem in America with no disease more prevalent or costly. Atherosclerosis is responsible for almost all cases of coronary heart disease. Endothelial dysfunction is a new precursor to atherosclerosis that starts long before traditional signs are seen. Whey and soy protein are just being investigated for their heart healthy effects on the vasculature. However, few studies have looked at both of their effects on at-risk college aged students. Subjects (n = 10) were college age (20.3 ± 1.95) individuals at risk for coronary heart disease (Framingham Risk Score) who completed an 8-week supplementation regiment (Whey, Soy, Control) and pre- and post-testing of flow-mediated dilation of the brachial artery. Outcomes for each group included lipid profiles, body composition, and flow-mediated dilation. There was no significance in velocity, diameter, or FMD(%) of the brachial artery between or within groups. ^ This study cannot prove or disprove the positive effects of whey and soy protein on flow-mediated dilation. However, with more participants trends are seen for positive affects within the vasculature.^

Comparison of the impact of a USDA nutrition & physical activity intervention versus a modified version in older adults

Sarah Arpino — Wed, 22 May 2013 16:07:08 PDT

Background: The United States Department of Agriculture developed an intervention to increase fruit and vegetable intake and participation in physical activity in older adults. The program was called Eat Smart Live Strong (ESLS) ^ Objectives: The overall purpose of this intervention was to determine the efficacy and behavioral impact of the ESLS program, and, further, to test the efficacy of an adaptation of the ESLS program based on a pilot of this program in Rhode Island. This adapted program was called Eat Smart Live Strong Rhode Island (ESLS-RI). ^ Setting and Design: This two (group) x two (occasion) quasi-experimental study was conducted over a four month period at two senior centers in Rhode Island. The ESLS program was a four week program for 60 minutes each session and the ESLS-RI was a six week program that was 40 minutes in length per session. The adaptations in ESLS-RI included shortening session times (six, 40 minute sessions compared to four, 60 minute sessions), increasing the didactic and experiential portion from 160 minutes to 180 minutes total, reducing the exercise from 80 minutes to 60 minutes total, and changing the timing of the exercise portion of the program (exercise occurs after the adapted lesson versus at the beginning and end in ESLS). ^ Participants: Subjects were women aged 55 years and older who had middle to low-income, were community-dwelling, and did not live in assisted living. A total of 23 women completed the pre and post survey (14 ESLS and nine ESLS-RI). ^ Results: There were no statistical differences between or within groups for fruit and vegetable intake or minutes walked per week. ^ Conclusion/Implications: This study was a step towards evaluating the effectiveness of the ESLS and modified ESLS-RI program. Nutrition educators can use this evaluation to help improve future nutrition education programs for older adults. ^

Manipulating quantum dot fluorescence by utilizing Brownian induced near-field interactions with plasmonic nanoparticles

Nola Palombo — Wed, 22 May 2013 16:07:07 PDT

Quantum dots (QDs) are semiconductor nanocrystals with size-dependent optical properties; thus making them supreme fluorophores. Plasmonic nanoparticles (PNPs), such as gold and silver nanoparticles, support localized surface plasmons on their surface. When the localized surface plasmons are excited, a highly concentrated electromagnetic field is formed near the particle. Therefore, if a QD is within the near-field of a PNP, the emission or excitation of the QD can be enhanced. However, due to Forster Resonance Energy Transfer (FRET), the QD fluorescence could instead be quenched by the proximity of PNPs. Whether enhancement or quenching occurs, is dependent upon the distance and geometry of the nanoparticles. Enhanced QD fluorescence would be helpful in biomedical sensing and imaging and solar energy conversion applications. In addition, quenched QD fluorescence caused by FRET could be applied to FRET-based sensing and imaging in medical diagnosis. ^ This master's thesis first theoretically models the stochastic movement of QDs and PNPs in an aqueous solution. The simulation is based upon the Direct Simulation Monte Carlo method coupled with Langevin equations. Using this simulation, we were able to predict the percentage of QDs in the near-field region of PNPs. The percentage of QDs in the near-field region of GNPs for a concentration of 1 × 10¹³ QDs/mL and 5 × 10⁸ GNPs/mL, is a very small percentage of 2 × 10^-5%. Yet, the concentration of QDs in the near-field region of GNPs was calculated to be 1,510,000 QDs mL-1. ^ In addition, this master's thesis experimentally explores the enhancement and quenching of QD emission for different concentrations and sizes of PNPs in aqueous solutions. The fluorescence spectra of two types of QD-PNP mixtures were measured. The first mixture was QDs and gold nanoparticles (GNPs) dispersed in distilled water, where the emission wavelength of the QDs matches the localized surface plasmon excitation wavelength of the GNPs. The second mixture was QDs and silver nanoparticles (SNPs) dispersed in distilled water, where localized surface plasmons affect the excitation of the QDs. For both experiments, the QD emission spectra were monitored while changing the concentration of the PNPs for a fixed concentration of QDs. At low PNP concentrations, the QD emission was enhanced by ∼ 20% for 30 nm GNPs and 80 nm SNPs; however, at high PNP concentrations, the QD emission was usually quenched. This research reveals the QD fluorescence is dependent upon the concentration and size of PNPs and concentration of QDs. Additionally, the enhancement factor was found to be dependent upon the QD concentration and independent upon temperature.^

Bloom formation of the toxic raphidophyte Heterosigma akashiwo in response to ocean acidification

Hyewon Kim — Wed, 22 May 2013 16:07:06 PDT

This master's thesis investigated the effects of acidified conditions on movement behaviors of the harmful algal bloom causing raphidophyte Heterosigma akashiwo. Individual movements of cells (i.e., swimming speed, turning rates, vertical velocity, declination, and diffusivity) were quantified using 3-D digital video analysis for a 6-h period and were compared among 3 pCO₂ treatments of 280, 380, and 750 ppm reflecting ocean carbonate chemistry in pre-industrial, current, and year 2100 at 2 different pH-acclimation conditions. We discovered that an abrupt decrease in pH levels significantly induced downward swimming of H. akashiwo (all p < 0.001), by exhibiting faster net vertical velocity (-31, -46, -66 µm s^-1 at 280, 380, 750 ppm, respectively) and an increase in downward moving fractions (68, 78, 87% at 280, 380, 750 ppm). However, pH-acclimation reduced this strong vertical downward bias, by increasing net vertical velocity (-23, -12, -47 µm s^-1 at 280, 380, 750 ppm) and decreased downward swimming populations (59, 56, 75% at 280, 380, 750 ppm) regardless of pCO₂ levels. Pre-acclimation significantly increased swimming speed (144 to 150 um s-1) at all pCO₂ levels (all p < 0.001) compared to swimming speed (110 to 119 um s-1) in pH-shock condition and resulted in 2.3 to 2.5 fold higher diffusivity (1.8×10⁵ to 2.2×10⁵ µm² s^-1) compared to diffusivity (8.0×10⁴ to 8.7×10⁵ µm² s^-1) in pH-shock. Either pCO₂ alteration or acclimation had no effects on turning rates (38.7 to 44.8 deg s^-1). Dispersal length of H. akashiwo bloom during 10-h implied a decreasing bloom dispersal in abrupt pH decreases but an increasing bloom dispersal in gradual pH decreases, emphasizing the importance of taking pH-acclimation status into account.^

Oxidative stress, antioxidants, and patterns of frugivory in migratory songbirds

Rebecca Rae Alan — Wed, 22 May 2013 16:07:05 PDT

Oxidative stress is an unavoidable consequence of metabolism and increases during intensive exercise. This may be especially problematic for migratory birds that metabolize fat to fuel long-distance flight. In order to mitigate this burden, birds can either increase endogenous antioxidant production (e.g. uric acid) or increase consumption of dietary antioxidants (e.g. tocopherol). During flight, birds may strategically increase protein catabolism of lean tissue, which may increase circulating uric acid and overall antioxidant capacity. In addition, many birds consume a primarily frugivorous diet during autumn migration and many fruits are excellent sources of dietary antioxidants. The goal of my research was to investigate the roles of endogenous antioxidants and dietary antioxidants in mitigating the negative effects of oxidative stress in migratory songbirds. In my first experiment, I evaluated three related hypotheses: (1) protein consumption is positively related to circulating antioxidants in a migratory passerine, (2) a dietary oxidative stressor [i.e. polyunsaturated fatty acid (PUFA)] influences both antioxidant capacity and oxidative damage, and (3) oxidative stress influences the dietary antioxidant preferences of captive songbirds. White-throated Sparrows consuming a high protein diet increased circulating uric acid as predicted; however, uric acid, antioxidant capacity, and oxidative stress did not differ between birds consuming a high PUFA versus a low PUFA diet, despite increased oxidative damage in high PUFA birds. Birds did not prefer antioxidant-rich diets even when fed high PUFA, low protein diets. ^ In a second experiment, I evaluated whether fruit selection by birds at a stopover site in southern New England was related to the antioxidant and macronutrient content of wild fruits from seven fall fruiting shrub species. My specific objectives were to: (1) quantify, for the first time, total hydrophilic and lipophilic antioxidants, as well as two specific types of lipophilic antioxidants (i.e. carotenoids and tocopherols) in these wild fruits, (2) determine how the antioxidant content of wild fruits during autumn migration is related to macronutrient composition, and (3) relate patterns of avian frugivory to antioxidant availability and macronutrient content of wild fruits during the fall. There were significant differences between fruits in lipophilic antioxidants, carotenoids, and tocopherols, but not in hydrophilic antioxidants. Arrowwood (Viburnum spp.) and northern bayberry (Myrica pennsylvanica ) had the most lipophilic antioxidants and tocopherols whereas Asiatic bittersweet (Celastrus orbiculatus) and multiflora rose (Rosa multiflora ) contained the most carotenoids. Carotenoid content was positively correlated with protein content but no significant relationships were evident between the other antioxidants and macronutrients. Fruit consumption was negatively correlated with carotenoid content and was not related to any other antioxidant measure. ^ Taken together, these data suggest that: (1) birds are capable of mounting an endogenous antioxidant response to oxidative damage that is independent of uric acid, other circulating antioxidants, and dietary antioxidants and (2) though a variety of factors influence avian fruit selection during autumn migration, birds may be able to alter the quantities and types of antioxidants they consume on the fruits they select at stopover during autumn migration. ^

Oxide materials discovery for high temperature sensing and energy harvesting applications

Matin Amani — Wed, 22 May 2013 16:07:05 PDT

The surfaces of turbine blades in modern gas turbine engines see temperatures as high as 1500°C, while simultaneously experiencing extremely high strain rates. Due to the harsh conditions, modeling of such systems has become incredibly complicated and does not provide sufficient accuracy. For these applications, sensors for characterization and energy harvesting devices for in-situ wireless diagnostics capable of operating in the turbine engine environment are of great interest. Multifunctional oxide semiconductors are ideally suited for such applications, since they can be easily engineered to operate in a variety of devices including thin lm thermocouples, strain gauges, and thermoelectric generators; they are also chemically stable at very high temperatures in oxidizing environments and exhibit excellent adhesion to the surfaces of thermal barrier coatings (TBCs) typically deposited on superalloy blades. In this dissertation combinatorial chemistry techniques are utilized to develop novel materials for these applications. ^

Coastal current effects on primary production rates and implications for ecosystem dynamics in Massachusetts Bay

M. Conor McManus — Wed, 22 May 2013 16:07:04 PDT

Primary production was measured from 1992-2010 in western Massachusetts Bay and Boston Harbor as part of the Massachusetts Water Resource Authority’s outfall monitoring program. In 2003, annual primary production rates decreased by 221-279 g C m^-2 year^-1 in both systems, with decreased rates continuing through 2010. Oceanographic and meteorological variables were analyzed with production rates to determine if concurrent changes in the environment were responsible for the reduced primary production rates in Massachusetts Bay. Zooplankton abundances and benthic flux rates were compared with production rates as well to determine if the decreased production rates had cascading effects on the ecosystem. ^ Based on a constructed conceptual model, results indicated that larger influxes of low saline water derived from the western Maine Coastal Current (WMCC) from 2003-2010 may have been responsible for the reduced production rates. Increased river discharge (particularly the Merrimack River) and intrusion of Labrador Subarctic Slope Water into the Gulf of Maine appear to have freshened the WMCC in recent years. More northeasterly winds over the last several years were favorable in penetrating WMCC waters into Massachusetts Bay. The correlations between primary production and stratification and surface salinities suggested an impact of the WMCC on production rates. I hypothesized in a conceptual model that increased stratification resulted in decreased vertical mixing and nutrient concentrations in the surface waters for phytoplankton growth, but there were no significant correlations between nutrient availability and stratification in available data. While the Massachusetts Bay primary production rates were influenced by changes in oceanography, rates in Boston Harbor were a result of nutrient removal from the Boston Harbor outfall diffuser relocation. Significant relationships between surface salinity and wind stress and river runoff in the Harbor suggests the system is more influenced by oceanographic variability than previously thought. The decline in Massachusetts Bay primary production appears to impact higher trophic levels and ecosystem processes in the summer. Zooplankton abundances, benthic ammonium fluxes and sediment oxygen demand with reduced primary production.^