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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.
141

Social-Cognitive Determinants of Success in Online Communities for Weight Management

Lane, Ilana Beth January 2016 (has links)
<p>Background: Online communities may be an effective, convenient, and relatively inexpensive intervention platform for individuals seeking assistance with weight management. Recent research suggests that these communities may be as effective as in-person treatments for weight management; however, very little is known about the characteristics that predict weight loss amongst those using an online community. Methods: Within a social-cognitive framework, we sought to identify the psychosocial characteristics that are associated with successful weight management for users of MyFitnessPal, a popular online community for weight management. We recruited participants who were new to the online community and asked them to complete 2 surveys (one at baseline and one 3 months later) that assessed various psychosocial constructs as well as self-reported height and weight. Results: Participants in our sample reported losing, on average, 4.55 kg during the 3-month time period. We found that engaging in weight control behaviors (e.g., monitoring food intake, weighing oneself, etc.) fully mediated the relationship between several of our variables of interest (i.e., baseline self-efficacy and perceived social support within the community) and weight loss. We also found that participants who expected to lose more weight at baseline were significantly more likely to have lost more weight at follow-up. Conclusions: On average, participants in our study lost a clinically meaningful amount of weight. Predictors of weight loss within this community included perceived support within the community (mediated by weight control behaviors), baseline self-efficacy (mediated by weight control behaviors), and baseline outcome expectations. Results of this study can ultimately serve to inform the design of future eHealth interventions for weight management.</p> / Dissertation
142

The Multidimensional Bullying Victimization Scale: Development and Validation

Harbin, Shannon Marie 30 June 2017 (has links)
One in three middle and high school students are victims of bullying (National Educational Association, 2012). The prevalence of bullying has increased over the past 10 years by approximately 25% (Nation Center of Education Statistics, 2013) and is now considered a public health concern. Published measures of bullying lack breadth and/or psychometric support. The present study created a psychometrically sound measure assessing bully victimization in adolescents. This measure examines three dimensions of bullying: direct, indirect, and evaluative. Items were generated based on information collected from student focus groups, as well as previously published measures and themes within recently published literature. Items were reviewed for inclusion and clarity. The measure was administered to children/adolescents between the ages of 11 and 18 within the public and private school system. This study resulted in a psychometrically sound, valid measure of bully victimization for use with adolescents. This measure includes three subscales (indirect, direct, and evaluative) and one composite score. These dimensions are positively correlated with internalizing and externalizing behavior problems.
143

Psychological and Environmental Predictors of Test Anxiety: A Structural Equation Model

Harris, Meredith Taylor 30 June 2017 (has links)
Test anxiety is a construct that includes cognitive, physiological, and behavioral symptoms occurring in response to anxiety prior to, during, or following examinations. The current literature on test anxiety has evaluated a number of possible predictors, including demographic variables, academic indicators, and self-perceptions. The movement toward school accountability and higher academic expectations of students has increased the severity of consequences occurring as a result of poor academic achievement. Thus, test anxiety is a critical concern that may impact student academic success. The current study evaluated a structural equation model to determine the strength of associations between trait anxiety, academic achievement, academic self-efficacy, and parental pressure, as well as how each of these variables predicted test anxiety among college undergraduates. The results indicated that trait anxiety and academic achievement predicted academic self-efficacy, and trait anxiety and academic self-efficacy predicted test anxiety. Factors that may have influenced the need for modifications to the structural model will be discussed, including psychometric concerns and theoretical implications.
144

Comparing Generic and Passage-Specific Assessments of Vocabulary and Fluency as Predictors of Reading Comprehension in Narrative and Expository Passages

Unknown Date (has links)
Previous research has investigated vocabulary and fluency as predictors of reading comprehension, most of it concentrating on younger school-age readers. The present study compared both passage-specific and generic assessments of vocabulary and fluency as predictors of reading comprehension in college-age readers. The comparison was done for both standardized tasks and experimental tasks and for expository and narrative text types. The study also investigated the effect of text type and question type (inferential and non-inferential) on reading comprehension. Seventy eight college-age readers completed a battery of reading comprehension, vocabulary and fluency tests. The results of the study reveal an interaction between passage type and question type on comprehension performance with students performing better on inferential questions for narrative texts, and on non-inferential questions for expository texts. Furthermore, vocabulary was found to be a better predictor of reading comprehension than fluency for both standardized and experimental tasks. / A Thesis submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Master of Science. / Degree Awarded: Fall Semester, 2006. / Date of Defense: July 28, 2006. / Inference Making / Includes bibliographical references. / Richard K. Wagner, Professor Directing Thesis; Colleen Kelly, Committee Member; Gretchen Sunderman, Committee Member.
145

Intentional Binding of Negative Items in Memory

Unknown Date (has links)
Memory for individual negative items, such as words and pictures, is consistently superior to memory for individual neutral items; however, recent research has found that relational memory for pairs of negative items is not enhanced relative to their neutral counterparts. The current experiments investigated the boundary conditions for this lack of negative associative memory enhancement and repeatedly found that memory for negative word pairs was not better than memory for neutral word pairs. In fact, cued recall of negative stimuli exceeded that of neutral stimuli only when word pairs were encoded holistically, as in the case of adjective-noun pairs. Findings are discussed in terms of the important dissociation between item and associative memory, and the implications of this distinction for theories of emotional memory in general. Finally, a discrete-emotion approach to emotional memory is introduced as one fruitful avenue for exploration. / A Dissertation submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Degree Awarded: Summer Semester, 2010. / Date of Defense: June 17, 2010. / Emotion, Cued Recall, Paired Associates, Associative Memory, Relational Memory / Includes bibliographical references. / Colleen Kelley, Professor Directing Dissertation; Robert Eklund, University Representative; Neil Charness, Committee Member; Michael Kaschak, Committee Member; Ashby Plant, Committee Member.
146

An Item-Specific and Relational Processing Account of Emotional Memory Enhancement

Unknown Date (has links)
Two experiments tested the competing item-specific and semantic cohesion hypotheses of emotional memory enhancement. The item-specific hypothesis predicts that emotional words receive more item-specific and less relational processing than neutral words, whereas the semantic cohesion hypothesis posits more relational processing of emotional words. In both experiments, emotional words were better remembered than neutral words. However, Experiment 1 found no support for either hypothesis; emotional and neutral words did not differ in the amount of either item-specific or relational processing, as measured by item gains and losses across repeated tests. Experiment 2 found that the memory advantage of emotional over neutral words did not differ as a function of the type of orienting task in which participants engaged. Several methodological explanations for the absence of the hypothesized findings are discussed along with future directions for research. / A Thesis submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Master of Science. / Degree Awarded: Summer Semester, 2008. / Date of Defense: April 30, 2008. / Recall / Includes bibliographical references. / Colleen M. Kelley, Professor Directing Thesis; Michael Kaschak, Committee Member; E. Ashby Plant, Committee Member.
147

Informal Number-Related Mathematics Skills: An Examination of the Structure of and Relations Between These Skills in Preschool

Unknown Date (has links)
Validating the structure of early numeracy skills is critical to understanding the developmental trajectories of mathematics skills at early ages. However, little research has been devoted to construct evaluation of the Counting, Numerical Relations, and Arithmetic Reasoning domains. This study was designed to address this gap in the literature by (a) developing a broad and deep measure of Counting skills, Numerical Relations skills, and Arithmetic Reasoning skills, (b) examining the structure of these three skill domains, and (c) examining the relations between these three domains. In Phase 1 of this study, measure development was conducted using a sample of 306 children (50.5% girls; 46.9% White, 41.0% African American, and 12.1% other). In Phase 2, further measure development was conducted as well as evaluation of the structure of and relations between the three domains using Confirmatory Factor Analysis. Three hundred ninety-three children from the Tallahassee and Panama City areas in Florida participated in Phase 2 (51.7% girls, 55.7% White, 33.8% African American, and 10.5% other). Results indicated that the relations between the early numeracy skills were best explained by a three-factor model of Counting, Numerical Relations, and Arithmetic Reasoning. The findings from this study provide a strong foundation upon which to build future research in early numeracy skills. / A Dissertation submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Degree Awarded: Summer Semester, 2010. / Date of Defense: October 30, 2009. / Informal Mathematics, Numbers, Numeracy, Education, Preschool, Mathematics / Includes bibliographical references. / Christopher J. Lonigan, Professor Directing Dissertation; Barbara Foorman, University Representative; Janet Kistner, Committee Member; Christopher Schatschneider, Committee Member; Jesse Cougle, Committee Member.
148

The Psychological Presence of Family Improves Self-Control

Unknown Date (has links)
Three studies supported the hypothesis that the psychological presence of family provides a temporary increase in self-control in three experiments. In Study 1, participants subliminally primed with the names of their family members subsequently performed better at an open-ended language task relative to participants primed with neutral words. Study 2 addressed two alternative ways of interpreting the results of Study 1. Participants in Study 2 who wrote a short essay about a family member with whom they had a good relationship demonstrated more self-control than those who wrote about a humorous episode or an enemy relationship, as measured by their performance on a simple but tedious math test. Study 3 was designed to demonstrate that self-control, rather than motivation, was affected by thoughts of the family. Participants primed with a visual cue of a family member ate fewer cookies than those not primed—when individual differences in eating restraint were controlled. / A Thesis submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Master of Science. / Degree Awarded: Fall Semester, 2007. / Date of Defense: June 21, 2007. / Family, Self-control / Includes bibliographical references. / Dianne M. Tice, Professor Directing Thesis; Charles Madsen, Committee Member; Roy F. Baumeister, Committee Member.
149

Guilty, Free and Wise: Determinism and Psychopathy Diminish Learning from Negative Emotions

Unknown Date (has links)
Emotional experiences can bring about personal growth. For instance, feeling guilty may prompt one to learn from a mistake, and this learning can bring about different and better future behavior. Four studies (N = 570) found that belief in free will facilitated learning from emotional experiences, as deterministic beliefs were associated with reduced learning. Studies included both correlational (Study 1) and experimental (Studies 2-4) designs. Emotional responsiveness, as defined by low psychopathy scores, also facilitated learning from emotional experiences (Studies 3 and 4). The degree of learning associated with emotional experiences was measured by self-rating (Studies 1 and 2), independent evaluations of lessons learned (Study 3), and whether participants joined a campus recycling program (after being made to feel guilty about an environmental transgression; Study 4). / A Dissertation submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Doctor of Psychology. / Degree Awarded: Summer Semester, 2009. / Date of Defense: July 7, 2009. / Determinism, Free Will, Psychopathy, Emotion, Guilt / Includes bibliographical references. / Roy Baumeister, Professor Directing Dissertation; Al Mele, Outside Committee Member; Dianne Tice, Committee Member; Frank Fincham, Committee Member; Thomas Joiner, Committee Member.
150

Cannabinoid Signaling in the Auditory Brain Stem of the Chick (Gallus Domesticus)

Unknown Date (has links)
Nucleus magnocellularis (NM) is a cochlear nucleus in the avian auditory brain stem which solely receives excitatory input from the auditory nerve fibers of cranial nerve VIII (cnVIII) and bilaterally innervates nucleus laminaris. The primary function of NM neurons is to code the temporal characteristics of acoustic stimuli and pass on this information to nucleus laminaris for use in coincidence detection and ultimately sound localization. Robust and dynamic stimuli could easily overwhelm many other synapses, but NM not only faithfully encodes important features of sounds, but can also enhance the information. Synaptic depression is one consequence of the large, rapid currents produced in NM in response to acoustic stimuli. The progressive decline in postsynaptic responses could lead to a failure in temporal coding. Therefore, depression must therefore be managed to allow coding not just at the onset, but throughout the duration of an ongoing stimulus. Many synaptic adaptations can be found at the cnVIII-NM synapse which act to dynamically adjust neuronal signaling in order to maintain consistent coding. GABAB receptors, in particular, present an interesting situation where activity-dependent inhibition can lead to an enhancement of neural signaling. The increase in synaptic reliability is presumably mediated through a conservation of neurotransmitter. The cannabinoid (CB) system represents another type of signaling that can mediate negative feedback, reducing neurotransmitter release. Furthermore the cannabinoid receptor one (CB1) is present in many sensory systems and is found throughout the brain of the chick. Relevant to auditory processing, the ganglion cells which form cnVIII produce CB1 mRNA. Immunohistochemical labeling of CB1 revealed that the calyceal terminals, not the cell bodies, of NM contain the functional receptor. Activation of these receptors with WIN 55,212-2 (WIN), a CB agonist, reduces excitatory postsynaptic currents, most likely through lowering of vesicle release probability. The high safety factor of neurotransmission at the calyx synapse means that a reduction in peak amplitude does not necessarily inhibit action potentials, but does appear to reduce the degree of observed synaptic depression. Endogenous CB production has been shown to occur in an activity-dependent manner, through either activation of metabotropic glutamate receptors or postsynaptic depolarization/intracellular Ca2+ rises. High frequency stimulation was able to induce an enhancement effect in current clamp which was blocked by pretreatment with a CB antagonist. The stimulation protocol was subsequently used under voltage clamp, but did not appear to initiate endogenous cannabinoid production as measured by paired-pulses. This finding suggests that metabotropic glutamate receptor activation is not sufficient to elicit cannabinoid production or paired-pulses are not a good measure in NM. If cannabinoids are produced endogenously at this synapse then the Ca2+-sensitive production pathway could be necessary as it require postsynaptic depolarization which does not occur under voltage clamp. A second way to measure CB effects is to measure the amplitude and frequency of spontaneous postsynaptic events. Picrotoxin, a GABAA antagonist, was used to isolate effects on glutamatergic signaling for study. In most cases picrotoxin had no effect; however, the drug was able to cause a near complete cessation of spontaneous postsynaptic currents in NM. A CB antagonist AM251 had an effect in the other direction and was able to preferentially increase the frequency, but not the amplitude of spontaneous events. These findings demonstrate that the vast majority of spontaneous depolarizing events are from random GABA release and there is a basal level of CB production even in an unstimulated slice. Another possibility is that the deafferentation-induced rise in intracellular Ca2+ caused this CB release. Unfortunately at this time we did not record from NM neurons with both picrotoxin and AM251 present in the bath. This limits our ability to interpret the data as it is not clear if the additional spontaneous events are from increased GABA or glutamate release. We did not detect any CB1 mRNA labeling of the superior olive which is responsible for the GABAergic input to NM. Also, WIN had an effect on depression even with picrotoxin present. This indirect evidence points to glutamate release as the underlying cause for the increased events. This study was by no means an exhaustive examination of CB signaling in the chick auditory brain stem. Rather, we made the first steps toward a new line of research as we now clearly know that CB1 is present and able to modulate signaling at the cnVIII-NM synapse. At this time we do not fully know how, to what degree, and when CB signaling is engaged. The functional purpose of CB would appear to enhance the coding of temporal events, however, we do not know at what scale. CB1 activation could function in a synapse-specific manner, complementary to GABAB activation, reducing synaptic depression at high rates of stimulation. Another, simpler role could be to maximize the signal to noise ratio by keeping the frequency of spontaneous glutamate release low. Further experiments will be needed to clarify these intriguing results. / A Dissertation submitted to the Department of Psychology in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Degree Awarded: Spring Semester, 2010. / Date of Defense: February 19, 2010. / Cannabinoid Electrophysiology Brain / Includes bibliographical references. / Richard Hyson, Professor Directing Dissertation; Timothy Logan, University Representative; Frank Johnson, Committee Member; Michael Meredith, Committee Member; Mark Licht, Committee Member.

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