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 Degree Level: Master's
Ab Initio and Density Functional Investigation of the Conformer Manifold of Melatonin and a Proposal for a Simple Dft-based Diagnostic for Nondynamical Correlation

Ab Initio and Density Functional Investigation of the Conformer Manifold of Melatonin and a Proposal for a Simple Dft-based Diagnostic for Nondynamical Correlation

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Date: August 2013
Creator: Fogueri, Uma
Description: In this work we address two problems in computational chemistry relevant to biomolecular modeling. In the first project, we consider the conformer space of melatonin as a a representative example of “real-life” flexible biomolecules. Geometries for all 52 unique conformers are optimized using spin-component scaled MP2, and then relative energies are obtained at the CCSD (T) level near the complete basis set limit. These are then used to validate a variety of DFT methods with and without empirical dispersion corrections, as well as some lower-level ab initio methods. Basis set convergence is found to be relatively slow due to internal C-H…O and C-H…N contacts. Absent dispersion corrections, many DFT functionals will transpose the two lowest conformers. Dispersion corrections resolve the problem for most functionals. Double hybrids yield particularly good performance, as does MP2.5. In the second project, we propose a simple DFT-based diagnostic for nondynamical correlation effects. Aλ= (1-TAE [ΧλC]/TAE[XC])/λ where TAE is the total atomization energy, XC the “pure” DFT exchange-correlation functional, and ΧλC the corresponding hybrid with 100λ% HF-type exchange. The diagnostic is a good predictor for sensitivity of energetics to the level of theory, unlike most of the wavefunction-based diagnostics. For GGA functionals, Aλ values approaching unity ...
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The Academic Steroid: Nonmedical Use of Prescription Stimulants at a North Texas University

The Academic Steroid: Nonmedical Use of Prescription Stimulants at a North Texas University

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Date: December 2014
Creator: Pennington, Cody W
Description: The goal of this study was to determine the extent, motivations, and justifications of nonmedical prescription stimulant use among the population at a large public university in the North Texas region. Participants consisted of 526 undergraduate students enrolled at the studied university during the spring and summer 2014 semesters. The findings of the study suggest that the nonmedical use by students was higher than the findings in much of the current literature, but was within the parameters established in the literature. The primary motivation for nonmedical use was academic in nature and was justified by moderation of nonmedical use to strategic academic times.
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Accuracy of Self-Reported Height, Weight, and Calculated BMI and Resulting FITNESSGRAM® Healthy Fitness Zone Classification

Accuracy of Self-Reported Height, Weight, and Calculated BMI and Resulting FITNESSGRAM® Healthy Fitness Zone Classification

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Date: May 2006
Creator: Rowell, Chelsie Joyce
Description: The determination of adiposity in adolescents is often assessed with calculations of body mass indices (BMI). Researchers often obtain these measurements from self-reported (SR) values. The purpose of this study was to determine the accuracy of SR height, weight, and calculated BMI (from height and weight). SR and actual measured (ME) BMI values were compared with standards from the FITNESSGRAM® Healthy Fitness Zone (HFZ) classifications. SR height and calculated BMI were found to be accurate while SR weight was, on average, underreported by 4.77 lbs. Because of these errors in SR height and weight, accuracy of classification into the FITNESSGRAM® HFZ was compromised. Consequently, it is important that researchers ascertain actual values of height and weight when measuring adolescents rather than use those from self-reports.
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Accuracy Variations in Human Facial Identification Based on Time of Exposure.

Accuracy Variations in Human Facial Identification Based on Time of Exposure.

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Date: December 2006
Creator: Cowle, Kenneth M.
Description: This study examined the relationship between time of exposure to the human face and accurate subsequent photo line-up identification. A volunteer group of 124 undergraduate students was divided into three approximately equal sized subgroups. The three groups were then exposed to a video or a portion of a video depicting a theft. Exposure times ranged from two minutes to 30 seconds. The subjects were then given a questionnaire and shown a photo line-up of the mock perpetrator and five foils. Subjects were asked to identify the perpetrator and mark that identification on the questionnaire. Results of the experiment indicated that the longer a subject was exposed the greater the possibility of an accurate identification.
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Acute Effects of the Antibiotic Streptomycin on Neural Network Activity and Pharmacological Responses

Acute Effects of the Antibiotic Streptomycin on Neural Network Activity and Pharmacological Responses

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Date: December 2014
Creator: Zeng, Wei Rong
Description: The purpose of this study is to find out that if antibiotic streptomycin decreases neuronal network activity or affects the pharmacological responses. The experiments in this study were conducted via MEA (multi-electrode array) technology which records neuronal activity from devices that have multiple small electrodes, serve as neural interfaces connecting neurons to electronic circuitry. The result of this study shows that streptomycin lowered the spike production of neuronal network, and also, sensitization was seen when neuronal network pre-exposed to streptomycin.
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Adherence and Haemagglutination of Moraxella Catarrhalis.

Adherence and Haemagglutination of Moraxella Catarrhalis.

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Date: August 2000
Creator: Kosterman, Edward, III
Description: M. catarrhalis is a gram-negative diplococci frequently associated with infections of the upper respiratory tract. During the past decade, some preliminary studies have attempted to elucidate mechanisms of adherence and haemagglutination of M. catarrhalis. These studies have reported, in many cases, inconsistent results. There are two purposes of this research. First, identify mechanisms that may potentially be associated with the adherence and haemagglutination of M. catarrhalis. Second, suggest research directions that may be fruitful in clarifying these mechanisms.
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Adolescent Insomnia as a Predictor of Early Adulthood Outcomes

Adolescent Insomnia as a Predictor of Early Adulthood Outcomes

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Date: December 2006
Creator: Roane, Brandy Michelle
Description: Recent research found insomnia is a risk factor for psychiatric disorders in adults. To see if the same would be true in adolescents, the current study re-analyzed data from a national longitudinal study collected by ADDHealth that evaluated health behaviors in 4552 adolescents (mean age 14.9 years [SD 1.7]) at baseline and again 7-8 years later (n = 3489) during young adulthood. Insomnia was reported by 9.2% of the adolescents. Cross-sectionally, adolescent insomnia was associated with alcohol, cannabis, non-cannabis drugs, and tobacco use, and depression after controlling for gender and ethnicity. Prospectively, adolescent insomnia was a significant risk factor for depression diagnosis, suicidal ideation, and the use of depression and stress prescription medications in young adulthood after controlling for gender, ethnicity, and significant baseline variable. In addition, a trend was noted for suicidal attempts.
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An Analysis of Major American Riots: Issues in Riots and Riot Control

An Analysis of Major American Riots: Issues in Riots and Riot Control

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Date: August 2001
Creator: Cinoglu, Huseyin
Description: By conducting sound research to understand the concepts surrounding rioting and efficient riot response tactics, professionals, especially whose main job is to ensure the tranquility in the society, will be better prepared to deal with all kinds of civil movements. The purpose of this study, consequently, is to meet the growing need for educational materials in this area and to provide riot response case studies, which demonstrate the numerous administrative challenges faced by law enforcement decision makers. In this study, seven major riots from throughout the United States are discussed including the Hay Market Riot of 1886, the Watts Riot of 1965, and Los Angeles Riots of 1992. Each riot case is studied in five different and independent stages: the setting and pre-disturbance situation, basic causes of the event, the disturbance situation, the response to the riot, and the aftermath of the incident. The study of all of these stages is intended to help police administrators acquire a general perspective on collective violence, and help them prevent future occurrences in their jurisdictions. In this thesis a special reference is given to the deficiencies of American riot policing and some recommendations were formed accordingly. Therefore, the study concludes with a list ...
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An Analysis of Motivational Cues in Virtual Environments.

An Analysis of Motivational Cues in Virtual Environments.

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Date: December 2003
Creator: Voruganti, Lavanya
Description: Guiding navigation in virtual environments (VEs) is a challenging task. A key issue in the navigation of a virtual environment is to be able to strike a balance between the user's need to explore the environment freely and the designer's need to ensure that the user experiences all the important events in the VE. This thesis reports on a study aimed at comparing the effectiveness of various navigation cues that are used to motivate users towards a specific target location. The results of this study indicate some significant differences in how users responded to the various cues.
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An Analysis of the Composition Process of Bartók's Eight Improvisations on Hungarian Peasant Songs, Op. 20

An Analysis of the Composition Process of Bartók's Eight Improvisations on Hungarian Peasant Songs, Op. 20

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Date: May 2000
Creator: Kochbeck, Olivia M.
Description: This is a study of Bartók's compositional process as it relates to the Improvisations, Op. 20. The study, which focuses on the analysis of the draft manuscript 50PS1, compares the draft and other relevant sources with the final composition. Bartók's framework for the entire Improvisations is based on a compositional strategy of pairing individual improvisations combined with systematic revision of the draft copy by the introduction of tritones as tonal equivalents and movement by fifths from semitones, to achieve structural coherence in the individual improvisations. The tonic-dominant relationship is used to rearrange the individual improvisations in the draft and tritones as tonal equivalents are used to propel the movement between the improvisations to produce a coherent whole.
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