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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.
111

THE E-T SCALE: INDIVIDUAL DIFFERENCES IN PREFERENCES FOR EPISTEMIC VERSUS TELEOLOGIC TACTICS OF DELIBERATE SELF-PERSUASION

Taylor, Cheryl 03 May 2011 (has links)
Maio and Thomas (2007) reviewed two types of tactics for changing one's own attitudes without additional information: epistemic and teleologic. Epistemic tactics involve interpreting negative characteristics more positively whereas teleologic tactics involve directing attention away from negative characteristics. In their extensive review, Maio and Thomas (2007) described situations in which people may prefer using either epistemic or teleologic tactics. Although they did not create a psychological scale to measure these preferences, they noted the importance of measuring individual differences. A psychological scale (i.e., the E-T Scale) was developed to measure preferences for epistemic versus teleologic tactics (Experiment 1). Reliability measure analyses and discriminant validity analyses with 11 other individual difference measures were also conducted (Experiment 2). Finally, a third experiment tested the proposed scale's construct validity with participants' memory recall for negative life characteristics. These experiments' results suggested that the E-T Scale reflects differences in the cognitive processes employed during attempts to change one's one attitudes.
112

MERCURY CONCENTRATIONS IN LARGEMOUTH BASS (MICROPTERUS SALMOIDES), WHITE BASS (MORONE CHRYSOPS), AND WHITE CRAPPIE (POMOXIS ANNULARIS) FROM SIX DALLAS-FORT WORTH AREA RESERVOIRS

Wadlington, Jacob Michael 03 May 2011 (has links)
Largemouth bass (Micropterus salmoides) are routinely monitored for mercury (Hg) in Texas reservoirs. Other piscivorous game-fish that may have high concentrations of Hg, such as white bass (Morone chrysops) and white crappie (Pomoxis annularis), are monitored less frequently because they are difficult to capture. Hg concentrations in largemouth bass, white bass, and white crappie from six Dallas-Fort Worth area reservoirs: Benbrook Lake, Eagle Mountain Lake, Grapevine Lake, Lake Lewisville, Joe Pool Lake, and Lake Ray Hubbard were examined. Fish were collected using electroshocking, trap nets and hook and line. For all species Hg concentrations were positively correlated with total length. Hg concentrations of each species were significantly different between reservoirs, indicating that some reservoirs were more contaminated with Hg than others. In the majority of reservoirs Hg concentrations in largemouth bass did not differ from Hg concentrations in white bass and white crappie. These data suggest that Hg concentrations in largemouth bass may be representative of Hg concentration in other piscivorous game-fish and is an appropriate indicator species for monitoring studies.
113

Evaluation Of A Cognitive Tool For Enhanced Problem-Solving And Coping

Kreitler, Crystal Mata 04 May 2011 (has links)
Many individuals have difficulty with problem-solving and coping, a phenomenon often exacerbated by excessive rumination over past trauma, and worry about the future. The present study examined the impact of a "fill-in-the-node" spatial display that guides participants through a systematic written examination of alternatives and action plans for managing difficult experiences in the future. The use of this cognitive tool will be combined with a session of problem-based writing (Pennebaker, 1996), a method commonly used to cope with past traumatic experiences. A group given the combination of one session of problem-based writing followed by a second session using the cognitive tool ACED IT was compared with a group receiving two sessions of past-oriented problem-based writing, a group given an initial session of past-oriented problem-based writing followed by a session of future-oriented problem-based writing, and with a group given no treatment. The results revealed that participants that completed two sessions of past-oriented problem-based writing reported less rumination and avoidant behavior than participants that completed future-oriented problem-based writing or control questionnaires. Additionally, participants in the past-oriented problem-based writing were also less likely to report a tendency to re-experience trauma than those who completed a future-oriented session or control questionnaires. Finally, participants that completed ACED IT reported a greater likelihood to revise their future coping strategies and include others in future coping than participants in all other groups.
114

BIOORGANIC STUDIES ON RECOGNITION OF SOLUBLE AMYLOID OLIGOMERS USING SMALL MOLECULES

Smith, Nicholas W. 04 May 2011 (has links)
Senile plaques composed of aggregates of amyloid peptides are the hallmark of Alzheimer's disease (Chapter 1). Recent studies indicated that soluble oligomers of the amyloid peptides are in fact the main neurotoxic species that impair neuronal function. The nature of these soluble oligomers still remains to be clarified, and spectroscopic detection of these soluble amyloid species using small molecular probes is currently an underdeveloped area of research. Dye-binding assays based on Congo red and thioflavin T dyes are the most widely used methods of assessing the aggregation of amyloid peptides. However, both dyes suffer from a number of disadvantages that often preclude the correct structural assessment of amyloid aggregates. In particular, when applied for the evaluation of the anti-aggregation ability of small molecules, these dyes often produce false-positive/negative results. Several recent accounts demonstrated that amphotericin B (AmB) could efficiently suppress amyloid aggregation. However, the inhibitory effect of AmB was established with one of the aforementioned dye-binding assays. Using circular dichroism spectroscopy as a dye-free tool, we were able to distinguish between the binding and inhibition of aggregation events (Chapter 2). It appeared that AmB could distinctly interact with both unordered and ordered Beta-structure-rich soluble amyloid oligomers, yet it had no measurable impact neither on the secondary structure nor on the time-dependent aggregation profile of the amyloid peptide. Thus, AmB could potentially be used as a CD-probe for studying conformational changes of soluble amyloid oligomers. In order to take advantage of the sensitivity of fluorescence-based techniques, we sought to develop novel small molecule probes that would not be subject to the limitations of the currently used dyes. Toward this end, we explored the ability of so-called BODIPY dyes to act as small molecule fluorescent probes for soluble amyloid oligomers. A straightforward functionalization of the BODIPY dyes via the incorporation of a triazole moiety produced fluorescent dyes that were capable of recognizing distinct conformations of soluble oligomeric species of amyloid peptides (Chapter 3). Subsequently, using the methodology developed in our laboratory, we prepared a series of iodo-triazole-containing BODIPY dyes that even further enhanced the sensitivity of these dyes towards various conformations of soluble amyloid oligomers (Chapter 4). Overall, our results demonstrate that these triazole-containing dyes could prove to be useful probes for monitoring conformational transitions of amyloid peptides in vitro.
115

Motivation, Misrepresentation, and Memory

Brady, Sara 04 May 2011 (has links)
Two experiments examined the hypothesis that misrepresentation of past attitudes and mating motives lead to reduced memory accuracy of past attitudes. In Experiment 1, participants told an attractive or unattractive member of the opposite sex their past attitude toward mandatory comprehensive exams. Participants told their partner their attitude either before or after learning that their partner was strongly in favor of mandatory exams. For participants who told their attitudes after learning their partner's attitude, participants who told an attractive partner recalled being more positive toward mandatory exams than participants who told an unattractive partner. Experiment 2 manipulated the target of telling the attitude (either to their partner or anonymously to the experimenter). The results from both experiments provide evidence that misrepresenting attitudes affects memory of initial attitudes. Mating motivation, furthermore, is one moderator that affects this relationship.
116

A POTENTIAL ROLE FOR LPS-INDUCED INFLAMMATION IN THE INDUCTION OF ALZHEIMER'S DISEASE-RELATED PATHOLOGY AND COGNITIVE DEFICITS

Kahn, Marielle Suzanne 04 May 2011 (has links)
Alzheimer's disease (AD) is characterized by neuronal cell death in regions of the adult brain, including the hippocampus, due to formation of amyloid-beta plaques and neurofibrillary tangles. Inflammation has been implicated in the onset and progression of these pathologies. Our study was designed to create an animal model of peripheral inflammation-induced AD-like pathologies using the bacterial endotoxin Lipopolysaccharide (LPS). C57BL/6J mice were given intraperitoneal injections of LPS or saline for 7 days. Hippocampal tissue from animals receiving LPS contained significantly higher levels of amyloid-beta 1-42 than did control animals. We also demonstrated that one injection of LPS leads to sickness behavior, but 7 days does not, implicating endotoxin tolerance. To determine if elevation in amyloid-beta 1-42 might inhibit learning, cognitive testing in both MWM and CFC, revealed learning deficits in LPS treated mice. In summary multiple injections of LPS resulted in increased amyloid-beta 1-42, in the hippocampus and cognitive deficits in mice.
117

FUNCTIONALIZATION OF BODIPY-DYE SCAFFOLD USING CLICK-CHEMISTRY REACTIONS

Polenz, Bradley P. 04 May 2011 (has links)
The design, synthesis and uses of small fluorescent molecules are among most active areas of modern research especially with 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) dyes. The spectroscopic properties of the BODIPY dyes can be altered by structural modification of the dye. One of the leading synthetic tools with many numerous applications is the copper-promoted alkyne-azide cycloaddition, commonly known as `click-chemistry'. Knowing the modification of BODIPY dyes, the use of a single alkyne-containing BODIPY scaffold might be an interesting tool to create several structurally and functionally-diverse fluorescent dyes using `click chemistry'-type of reactions (Chapter 1). Earlier cycloaddition studies in the group found a small amount of 5-I-triazole-BODIPY as a side product. It was found that low concentrations of the alkyne and the use of DMAP led to the formation of 5-I-triazoles as the only cycloaddition products. This methodology was applied for the synthesis of the 5-iodo-triazole-containing BODIPY dyes (Chapter 2). Modification of a BODIPY scaffold via isoxazole tether was demonstrated for the first time. It was discovered that ZnBr2 is a viable general catalyst for the formation of the isoxazole moiety. Some of the isoxazole-click BODIPY dyes were tested for their ability to recognize distinct conformations of the soluble amyloid oligomers (Chapter 3). Using photochemistry to facilitate the tio-yne reaction it appeared that by simply switching solvents, it was possible to completely switch between cis and trans isomers of the BODIPY dyes (Chapter 4).
118

High Diversity and Lack of Genetic Structure in Eastern Red Bats (Lasiurus borealis)

Korstian, Jennifer 04 May 2012 (has links)
The purpose of our study was to characterize the genetic diversity and population genetic structure of eastern red bats (Lasiurus borealis) killed during fall migration at a wind farm in north-central Texas over a three-year period (2009-2011). Microsatellite loci and mitochondrial haplotypes showed high levels of genetic diversity in this species. The pattern of diversity observed in the haplotype network is consistent with what is seen in species that have undergone rapid population and range expansions since the last ice age. Both clustering analysis (i.e. grouping individuals by genetics alone) and partitioning analysis (i.e. grouping by specific characteristics such as year and fatality pulse) indicated that our samples represent a single population without genetically distinct subunits. The eastern red bats sampled from our study site, which includes a mix of migratory and resident individuals, likely represents one, large population of bats with high levels of gene flow among local populations.
119

SPATIAL PATTERNS OF MERCURY CONTAMINATION OF FISH IN THE SOUTH CENTRAL UNITED STATES

Jones, Christina Michelle 04 May 2012 (has links)
Mercury (Hg) is a toxic metal that is found in aquatic food webs and is hazardous to humans. An emerging conceptual model predicts areas with the potential to contain food webs with elevated concentrations of Hg receive high amounts of Hg and sulfate deposition, have high coverage of forests and wetlands and low coverage of agriculture. The objective of this study was to test this conceptual model using concentrations of Hg in fish in the south central United States. Coverage by evergreen forests explained 73 percent of the variance of average mercury concentrations in the 14 ecoregions. Over 70% of the water bodies in ecoregions with evergreen forest coverage of 20% or greater have Hg concentrations in largemouth bass above the EPA criterion level of 300 ng/g. Evergreen forests in states in the southern ecoregions may constitute a significant hazard to human health through increased exposure to Hg from fish.
120

AGE-RELATED CHANGES IN HEAT SHOCK PROTEIN EXPRESSION IN THE MOUSE HIPPOCAMPUS

Mitchel, Jeffrey Stewart 04 May 2012 (has links)
ABSTRACT AGE-RELATED CHANGES IN HEAT SHOCK PROTEIN EXPRESSION IN THE MOUSE HIPPOCAMPUS by Jeffrey Stewart Mitchel, Jr., M.S. 2012 Department of Biology Texas Christian University Thesis Advisor: Dr. Michael J. Chumley, Assistant Professor of Biology Heat shock proteins (Hsps) serve as the cell's natural mechanism for circumventing protein misfolding and aggregation often involved in cellular stress. These stressors can lead to neurodegenerative pathologies like Alzheimer's disease (AD). Research suggests that aged animals lose the ability to upregulate Hsps in response to an acute stress, and this disregulation may contribute to the onset of AD. We hypothesize that aged animals will show elevated Hsp levels due to the increase in cellular stress associated with aging. We further hypothesize that this increased level of Hsps will inhibit the aged animal from further expressing Hsps in the event of an acute stress. We compared basal and inducible brain hippocampus levels of four Hsps previously shown to stabilize two proteins commonly associated with AD, amyloid beta and tau. Our results support our hypothesis that Hsp expression changes with age and may be a contributing factor in AD.

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