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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
771

Memory Patterns: Differentiated between Environmental Sensitive Patients and Psychiatric Patients

Lockart, Esther 08 1900 (has links)
The purpose of the present study was to ascertain if environmentally sensitive patients would demonstrate different memory deficit patterns than psychiatric patients on objectively measurable memory tasks. One-hundred sixteen patients were surveyed; 56 environmentally sensitive patients were compared to 60 psychiatric patients. All subjects were administered a Wechsler Adult Intelligence Scale-Revised screen, the Wechsler Memory Scale-Revised and the Harrell-Butler Comprehensive Neurocognitive Screen after history of head injury was ruled out. Results indicate a significantly different pattern of memory dysfunction between the environmental patients and the psychiatric patients, indicating two different etiologies. A screening device derived from the coefficients from a Canonical Analysis is proposed to distinguish between the two populations in the absence of blood serum levels of environmental toxins or poisons. The detrimental effects of misdiagnosis and the beneficial effects of accurate diagnosis of environmental illness are discussed.
772

Leadership Styles and Cultural Sensitivity of Department Chairs at Texas Public Universities

Hernandez-Katz, Melissa 05 1900 (has links)
As the U.S. population diversifies, so do its higher education institutions. Leadership at these institutions should be prepared for this diversification of students, faculty, and staff. The purpose of this study was to gain greater knowledge about the leadership styles and cultural sensitivity of department chairs. Survey research was used to determine if department chairs’ leadership styles correlated with their cultural sensitivity. The target population was department chairs from public universities in the state of Texas. The survey was distributed to 406 randomly selected department chairs. The participants completed three measures: Leadership Behavior Description Questionnaire (LDBQ) for leadership style, the Intercultural Sensitivity Scale (ISS) for cultural sensitivity, and a demographic questionnaire (gender, age range, race/ethnicity, and years of service as department chair). The sample included 165 usable surveys (40% return rate). The department chairs were primarily male (72%), White (78%), and over 50 (71%) years of age. First, a statistically significant negative correlation (r = -.431, p < .0001) occurred between LBDQ overall scores and overall ISS scores: As chairs scored higher on leadership ability, they scored lower on intercultural sensitivity. Second, leadership style by demographic variable displayed mixed results. No significant difference was found for leadership style by age, gender, years of service, or region of service. For ethnicity, White participants scored significantly lower than Minority participants on the LBDQ scales of consideration (t [162] = -2.021, p = .045), structure (t [162] = -2.705, p = .008), and overall (t [162] = -2.864, p = .005). Minority participants might work more diligently to increase their leadership abilities based on their higher LDBQ scores. Third, findings on intercultural sensitivity by demographic variable were mixed. No statistical significance was observed between any of the ISS scales and age, gender, years of service, and region. For ethnicity, Minority participants’ scores showed significantly lower intercultural sensitivity than White participants scores on two of six ISS subscales: interaction enjoyment (t = -2.46, p = .015) and respect (t = 2.107, p = .037). It was concluded that the Minority and White department chairs’ leadership style and intercultural sensitivity differences could be due in part to differences in the chairs’ ethnic affiliations, associated cultural backgrounds, and views of dominant versus non-dominant cultures. Recommendations for study are included.
773

Susceptibility to Peer Influence for Engagement in Relational Aggression and Prosocial Behavior: The Roles of Popular Peers, Stress Physiology, and Gender

Lafko, Nicole Lin 01 January 2015 (has links)
The overall goal of the current study was to determine if perceptions of popular peers' relationally aggressive (PPSRA) and prosocial behaviors (PPSP) were related to engagement in these behaviors in a sample of emerging adults. This study also investigated if these associations were moderated by sympathetic nervous system (SNS) and parasympathetic nervous system (PNS) reactivity to peer stress and gender. Although a significant amount of research suggests that aggressive behaviors can be socialized by peers (e.g., Molano, Jones, Brown, & Aber, 2013), there is a dearth of work that has examined relational forms of aggression that tend to be more salient for females and more positive, prosocial behaviors. Further, given that some research suggests that perceptions about how peers behave, regardless of peers' actual behavior, influences individual behavior (e.g., Song et al., 2012), the current study investigated the impact of perceptions of peer behavior. Additionally, research suggests that some individuals are more susceptible to peer influence than others (e.g., Steinberg & Monahan, 2007). Biological Sensitivity to Context (BSC) has been offered as a potential explanation for this differential susceptibility to peer influence (e.g., Boyce & Ellis, 2005). BSC theory postulates that individuals with a heightened stress response are more malleable to environmental influence, for better or worse; therefore, the interaction between PNS reactivity to stress (measured by respiratory sinus arrhythmia [RSA-R]) and SNS reactivity (measured by skin conductance level [SCL-R]) to a relational stressor was examined as a moderator in the current study. Gender was also examined as a moderator. 200 emerging adults aged 18-23 years (70% female; Mage= 19.04) were recruited from introductory psychology courses at a Northeastern public university. Participants' SCL-R and RSA-R were assessed during a laboratory stress protocol during which they recounted an experience of relational stress. PPSRA, PPSP, and gender were gathered via self-report. Findings suggest that PPSRA was positively related to self-reported engagement in relational aggression and, similarly, PPSP was positively associated with self-reported engagement in prosocial behavior. However, neither interactions between RSA-R and SCL-R nor gender significantly moderated these relationships. Follow-up analyses indicated PPSP was significantly, negatively related to engagement in relational aggression for males only. Findings suggest that perceptions about the behavior of popular peers do have an important influence on college students' behavior and highlight future directions for research into the factors that may modify this relationship.
774

Molecular studies of the synaptic protein otoferlin

Müller, Alexandra 08 April 2016 (has links)
No description available.
775

From Linkage to GWAS: A Multifaceted Exploration of the Genetic Risk for Alcohol Dependence

Adkins, Amy 10 December 2012 (has links)
Family, twin and adoption studies consistently suggest that genetic factors strongly influence the risk for alcohol dependence (AD). Although the literature supports the role of genetics in AD, identification of specific genes contributing to the etiology of AD has proven difficult. These difficulties are due in part to the complex set of risk factors contributing to the development of AD. These risk factors include comorbidities with other clinical diagnoses and behavioral phenotypes (e.g., major depression), physiological differences that contribute to the differences between people in their level of response to ethanol (e.g., initial sensitivity) and finally the large number of biological pathways targeted by and involved in the processing of ethanol. These complexities have probably contributed to the limited success of linkage and candidate gene association studies in finding genes underlying AD. The powerful and unbiased genome-wide association study (GWAS) offers promise in the study of complex diseases. However, due to the complexities of known risk factors, GWAS data has yet to provide consistent, replicable results. In light of these difficulties, this dissertation has five specific aims which attempt to investigate genetic risk loci for AD and related phenotypes through improved methods for candidate gene selection, analysis of a pooled genome-wide association study, genome-wide analyses of initial sensitivity and maximum alcohol consumption in a twenty-four hour period and finally, creation of a multivariate AD/internalizing phenotype.
776

Genetic Analysis of Ethanol Sensitivity and Tolerance in Drosophila

Chan, Robin 10 July 2013 (has links)
The genetic pathways influencing alcohol abuse and dependence are poorly characterized. Many critical discoveries about the interactions between ethanol-related behaviors and genetics have been made in the fruit fly Drosophila melanogaster. Coupling the statistical power of model organism studies to human association studies bolsters the analytical efficacy of these genomic approaches. A variety of behavioral assays are available for assessing behavioral responses to ethanol in Drosophila. However, we find our previously described eRING assay is influenced by the commonly used transgenic marker mini-white. We developed a Simple Sedation Assay (SSA) that is insensitive to the effects of white and mini-white. In SSAs, expression of endogenous wild-type white was not necessary for normal responses to ethanol. Neither expression nor RNAi-mediated knockdown of the transgenic mini-white influenced the effects of ethanol in flies. Critically, mini-white expression did not affect the phenotypes of flies with known alterations in ethanol sensitivity. Also, loss of function mutations in Clic show decreased sensitivity to ethanol in both eRING assays (as previously reported) and SSAs. Therefore, we explored the role of the known Clic interactors, TGF-β and ryanodine receptors. These studies were inconclusive but do not exclude the need for future work. Finally, using bioinformatic tools we constructed a mutli-species network of genes predicted to interact with Clic. Our RNAi screen against the Clic network serves as an important proof-of-concept and holds great potential for uncovering important therapeutic targets for alcohol use disorders.
777

Effectiveness of Sensory Integration and Behavioral Interventions on Nonengagement in Preschool Aged Children

Kuyper, Tiffany 01 January 2012 (has links)
Abstract EFFECTIVENESS OF SENSORY INTEGRATION AND BEHAVIORAL INTERVENTIONS ON NONENGAGEMENT IN PRESCHOOL AGED CHILDREN By Tiffany Ann Kuyper, OTR/L A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Occupational Therapy at Virginia Commonwealth University Virginia Commonwealth University, 2012 Director: Marie Anzalone ScD, OTR, FAOTA This single subject pilot study explored a combination of sensory-based interventions and behavioral interventions in a preschool aged child identified with Sensory Over-Responsivity (SOR). Children often display nonengagement associated with escaping and avoiding tactile and/or vestibular information because they perceive sensory input as negative or aversive. The subject was a 3-year old child who engaged in alternating treatments over the course of six weeks of occupational therapy. The first condition was a sensory-based intervention (SB), a widely used intervention approach for sensory over-responsivity. The alternating condition was a sensory-based intervention combined with behavioral interventions (SBB). The behavioral intervention used tangible reinforcement as the primary technique to facilitate engagement in sensory intensive play that was part of the sensory-based interventions. It was hypothesized that nonengagement behaviors would decrease during the SBB condition and play engagement behaviors would increase during the SBB condition. It was also hypothesized that the subject would demonstrate an improvement in perceived performance and satisfaction of daily living activities. The outcomes of this study included frequencies of nonengagement, play engagement and the family’s perceived performance and satisfaction of a child’s performance of occupations. The frequency of nonengagement behaviors was assessed when the subject was presented with sensory intensive play that was part of sensory-based interventions in each condition. The frequencies of nonengagement and play engagement were coded over each session to determine if there was any change between and within conditions. Also, performance and satisfaction with occupations were compared from the initial evaluation and the last intervention session. Results of this study revealed that the subject’s nonengagement behaviors actually increased throughout the interventions. This finding did not support the first hypothesis that nonengagement behaviors would decrease in the condition using a combination of sensory-based interventions and behavioral interventions. It was also found that the subject’s number of play engagement behaviors decreased within both conditions. This finding did not support the second hypothesis that play engagement behaviors would improve as result of participating in a combination of sensory-based interventions and behavioral interventions over time. However, the qualitative improvements as identified by the subject’s mother when using the Canadian Occupational Performance Measure (COPM; Law, Baptiste, McColl, Polatajko, & Pollock, 2005) improved significantly across both interventions in the home and community settings. As a result of participation in this study, the subject made improvements with regard to all occupational performance areas as initially collaborated upon in the initial evaluation.
778

Analyse de sensibilité de modèles spatialisés : application à l'analyse coût-bénéfice de projets de prévention du risque d'inondation / Variance-based sensitivity analysis for spatially distributed models : application to cost-benefit analysis of flood risk management plansSpatially distributed model; Sensitivity analysis; Uncertainty; Scale; Geostatistics;CBA; Flood; Damage.

Saint-Geours, Nathalie 29 November 2012 (has links)
L'analyse de sensibilité globale basée sur la variance permet de hiérarchiser les sources d'incertitude présentes dans un modèle numérique et d'identifier celles qui contribuent le plus à la variabilité de la sortie du modèle. Ce type d'analyse peine à se développer dans les sciences de la Terre et de l'Environnement, en partie à cause de la dimension spatiale de nombreux modèles numériques, dont les variables d'entrée et/ou de sortie peuvent être des données distribuées dans l'espace. Le travail de thèse réalisé a pour ambition de montrer comment l'analyse de sensibilité globale peut être adaptée pour tenir compte des spécificités de ces modèles numériques spatialisés, notamment la dépendance spatiale dans les données d'entrée et les questions liées au changement d'échelle spatiale. Ce travail s'appuie sur une étude de cas approfondie du code NOE, qui est un modèle numérique spatialisé d'analyse coût-bénéfice de projets de prévention du risque d'inondation. On s'intéresse dans un premier temps à l'estimation d'indices de sensibilité associés à des variables d'entrée spatialisées. L'approche retenue du « map labelling » permet de rendre compte de l'auto-corrélation spatiale de ces variables et d'étudier son impact sur la sortie du modèle. On explore ensuite le lien entre la notion d'« échelle » et l'analyse de sensibilité de modèles spatialisés. On propose de définir les indices de sensibilité « zonaux » et « ponctuels » pour mettre en évidence l'impact du support spatial de la sortie d'un modèle sur la hiérarchisation des sources d'incertitude. On établit ensuite, sous certaines conditions, des propriétés formelles de ces indices de sensibilité. Ces résultats montrent notamment que l'indice de sensibilité zonal d'une variable d'entrée spatialisée diminue à mesure que s'agrandit le support spatial sur lequel est agrégée la sortie du modèle. L'application au modèle NOE des méthodologies développées se révèle riche en enseignements pour une meilleure prise en compte des incertitudes dans les modèles d'analyse coût-bénéfice des projets de prévention du risque d'inondation. / Variance-based global sensitivity analysis is used to study how the variability of the output of a numerical model can be apportioned to different sources of uncertainty in its inputs. It is an essential component of model building as it helps to identify model inputs that account for most of the model output variance. However, this approach is seldom applied in Earth and Environmental Sciences, partly because most of the numerical models developed in this field include spatially distributed inputs or outputs . Our research work aims to show how global sensitivity analysis can be adapted to such spatial models, and more precisely how to cope with the following two issues: i) the presence of spatial auto-correlation in the model inputs, and ii) the scaling issues. We base our research on the detailed study of the numerical code NOE, which is a spatial model for cost-benefit analysis of flood risk management plans. We first investigate how variance-based sensitivity indices can be computed for spatially distributed model inputs. We focus on the “map labelling” approach, which allows to handle any complex spatial structure of uncertainty in the modelinputs and to assess its effect on the model output. Next, we offer to explore how scaling issues interact with the sensitivity analysis of a spatial model. We define “block sensitivity indices” and “site sensitivity indices” to account for the role of the spatial support of model output. We establish the properties of these sensitivity indices under some specific conditions. In particular, we show that the relative contribution of an uncertain spatially distributed model input to the variance of the model output increases with its correlation length and decreases with the size of the spatial support considered for model output aggregation. By applying our results to the NOE modelling chain, we also draw a number of lessons to better deal with uncertainties in flood damage modelling and cost-benefit analysis of flood riskmanagement plans.
779

Caractérisation expérimentale et prédiction de la formabilité d'un alliage d'aluminium en fonction de la température et de la vitesse de déformation / Experimental characterization and prediction of the formability of an aluminium alloy considering temperature and strain rate effects

Chu, XingRong 20 February 2013 (has links)
Les procédés de mise en forme de tôles minces sont très largement répandus dans l’industrie. Néanmoins, l’utilisation de ces procédés est limitée par le niveau de formabilité du matériau formé, notamment dans le cas des alliages d’aluminium. Afin d’améliorer ces limites de formabilité, des procédés de mise en forme à chaud peuvent être envisagés. L’objectif de cette thèse est d’étudier à l’aide d’approches expérimentale et numérique l’effet de la température et de la vitesse de déformation sur la formabilité des tôles en alliage d’aluminium AA5086 et de proposer une modélisation capable de prédire ces effets. Une campagne d’essais a été réalisée sur ce matériau à partir d’un essai d’emboutissage de type Marciniak. Des courbes limites de formage (CLF) ont été établies sur une plage de température allant de l’ambiant jusqu’à 200°C et pour des vitesses de déformation allant du quasi-statique à 2s-1. Des effets, positif de la température et négatif de la vitesse de déformation sur la formabilité ont été mis en évidence. La prise en compte des effets de la température et de la vitesse de déformation dans les modèles prédictifs des CLF, qu’ils soient analytiques ou numériques, est à ce jour très limitée. Dans ce travail, un modèle numérique prédictif basé sur la simulation par éléments finis du modèle géométrique de Marciniak et Kuczynski (M-K) est proposé. Les déformations limites obtenues avec de ce modèle sont très sensibles à la description du comportement thermo-viscoplastique du matériau et à la calibration du défaut géométrique pilotant l’apparition de la striction dans le modèle M-K. Des essais de traction uniaxiale réalisés dans les mêmes conditions opératoires que les essais de mise en forme de Marciniak ont permis d’identifier des lois d’écrouissage de nature très différentes (rigidifiante, saturante ou mixte). Ces lois conduisent à des prédictions très différentes de la formabilité du matériau pour une valeur donnée du défaut géométrique du modèle EF M-K. Différentes stratégies de calibration de la taille de ce défaut initial ont été envisagées. L’utilisation du point expérimental de la CLF correspondant à des conditions de déformation plane permet de calibrer de manière satisfaisante la valeur de ce défaut. Cette procédure de calibration a été appliquée pour l’ensemble des lois identifiées. Les lois de nature rigidifiante de type Ludwick se sont montrées les plus effficaces alors que les lois saturante de type Voce se sont avérées incapables de prédire la formabilité du matériau pour certaines conditions opératoires. Finalement, il est démontré qu’une valeur constante du défaut géométrique ne peut être retenue pour l’ensemble des conditions opératoires étudiées même si le modèle M-K s’est avéré assez efficace pour représenter l’effet de la température plutôt que celui de la vitesse de déformation. / Sheet metal forming processes are widely used in industry. Nevertheless, the use of these processes is limited by the formability of the considered material, in particular in the case of the aluminium alloys. To improve the formability, warm forming processes can be considered. The objective of this work is to study by means of both experimental and numerical approaches, the effects of temperature and strain rate on the formability of AA5086 aluminium alloy sheets and to propose a modeling suitable to predict these effects. Experimental tests have been carried out on this material by means of the Marciniak stamping experimental device. Forming limit curves (FLCs) have been established on a temperature range going from ambient temperature to 200°C and on a strain rate range going from quasi-static up to 2s-1. A positive effect of the temperature and a negative effect of the strain rate on the formability limits were highlighted. To date, very few predictive models of the FLCs taking into account temperature and strain rate effects are proposed in the literature. In this work, in order to predict the experimental temperature and strain rate sensitivities, a predictive model based on the finite element simulation of the Marciniak and Kuczynski (M-K) geometrical model is proposed. The limit strains obtained with this model are very sensitive to the description of the thermo-viscoplastic behaviour modeling and to the calibration of the initial geometrical imperfection controlling the onset of the necking. Thanks to tensile tests carried out for the same operating conditions that those of Marciniak forming tests, several types (power law, saturation and mixed) of hardening laws have been identified. These hardening laws have been implemented in theFE M-K model to obtain numerical limit strains. Very different formability limits have been observed for a given value of the geometrical defect. Several strategies for the calibration of this initial imperfection size have been tested. The use of the experimental point of the FLC0 corresponding to plane strain condition allows a good calibration of the initial imperfection value. This calibration procedure was carried out for all hardening laws. It is shown that the power law type models such as Ludwick law are more efficient while saturation laws such as Voce law are unable to predict the material formability for some conditions. Finally, it is shown that a constant value of the geometrical defect cannot be used to the whole operating conditions studied even if FE M-K model is shown to be efficient to represent the temperature effect rather than strain rate one.
780

The impact of N-3 pufa ingestion on metabolic, molecular and epigenetic responses to a short-term high-fat diet

Wardle, Sophie L. January 2015 (has links)
Obesity is widely considered a primary risk factor for type 2 diabetes (T2D). However, less is known about the early adaptive responses to short-term periods of high-fat energy excess (HFEE). Previous reports detailing whole-body adaptation to fat and energy oversupply are equivocal, perhaps, in part, owing to use of different experimental protocols, varying durations of dietary manipulation and participant cohorts with individuals of varying characteristics. In addition to use of different dietary protocols between studies, alterations in functional end-point measures due to the type of dietary fat consumed warrants consideration. Daily n-3 PUFA intake, commonly obtained from pelagic fish oil (FO) consumption, has been shown to positively associate with insulin sensitivity in epidemiological studies and thus may be a useful dietary strategy for slowing insulin resistance development. Chapter 2 of this thesis extends previous literature by demonstrating that 6 d HFEE (150 % habitual energy intake; 60 % of energy from fat) does not clearly alter whole- body insulin sensitivity, irrespective of FO consumption. However, investigation of metabolism at the tissue level, as presented in Chapter 3 of this thesis, offers insight into a potential tissue-specific level of regulation that precedes whole-body regulation. Skeletal muscle insulin signalling protein (e.g. protein kinase B (PKB)) activity, levels of certain ceramide species, and AMPK α2 activity were altered following HFEE and may explain the early maladaptive responses to short-term HFEE. Moreover, FO intake as 10 % of total fats mediated some of these molecular responses, including PKB and AMPK α2 activity, reflecting possible functional effects of FO at the subcellular level. Regulation of these metabolic / molecular responses at both the tissue and whole- body level can be explained, in part, by genetic predisposition, environmental influence and more recently epigenetics, including microRNAs (miRNAs). In Chapter 4, we characterised the plasma and skeletal muscle miRNA responses to HFEE and oral glucose ingestion. We demonstrate transient changes in levels of certain miRNAs following oral glucose ingestion in both tissue types and in response to HFEE in skeletal muscle. However, no significant correlations between basal plasma and skeletal muscle miRNA levels were observed, suggesting that our candidate plasma miRNAs may be co-ordinating functional changes in other tissue types. Plasma miR- 145-5p and skeletal muscle miR-204-5p predicted a significant proportion of the variance in mean whole-body insulin sensitivity change in response to HFEE. These data indicate that these miRNAs may be useful biomarkers of insulin resistance development following HFEE. A constraint of this thesis is that all conclusions are made within the context of statistically unaltered insulin sensitivity. Therefore, future investigations of diet-induced maladaptation should consider establishing a time course of insulin resistance development in response to HFEE, or use different study populations. Populations that are more susceptible to T2D development, e.g., overweight, sedentary individuals would be of particular interest. These data would aid development of a working model of diet-induced insulin resistance that has more direct application to T2D progression and extends the data presented herein.

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