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Ultrafast Laser Sampling of a Plant Tissue and ion Conductivity Measurement for Investigation of Light Stress Generation Mechanisms (open access)

Ultrafast Laser Sampling of a Plant Tissue and ion Conductivity Measurement for Investigation of Light Stress Generation Mechanisms

In this study we applied ultra-short laser pulses on a biological sample (Arabidopsis), in order to cut it precisely in a square pattern and subsequently use it for studying stress generation mechanisms. For this purpose, we utilized femtosecond laser pulses at 100 fs pulse width and 80 MHz repetition rate. We took two processing parameters into consideration such as laser power, laser exposure time which is related to the stage speed. Therefore, we were able to find the laser optimum conditions for ablation of biological tissues. The mutant and wildtype (control) obtained from laser cutting with a size of 500 µm × 500 µm were directly transferred (in-situ with laser cutting) into a microfabricated chamber containing ~500 nanoliters deionized water for measuring ion conductivity. The ion conductivity is a signature of cell-death mechanisms caused by various stresses. A light with intensity of 100 µmol was exposed to the samples for 2 hours and 20 minutes as a source of stress. A quantitative electrical analysis with high accuracy was assured by utilizing a microchamber, which enables a measurement in nanoliter volume. We measured the impedance which is reciprocal of conductivity using a lock-in amplifier and a precise current source at frequency …
Date: August 2010
Creator: Abtahi, Seyed Ali
System: The UNT Digital Library
Photoactivatable Quantum Dots in Super-Resolution Microscopy of Muscle (open access)

Photoactivatable Quantum Dots in Super-Resolution Microscopy of Muscle

Super-resolution 3D imaging was achieved using newly synthesized photoactivatable quantum dot (PAQ dot) probes. Quantum dots were modified with a novel quencher system to make them photoactivatable. The unique properties of these PAQ dots enable single-fluorophore localization in three dimensions using a confocal microscopy optical sectioning method. Myosin and tropomyosin of rabbit myofibrilar bundles were specifically labeled with the newly synthesized PAQ dot. A sufficient number of single quantum dots were photoactivated, localized and reduced to their centroid and then reconstructed to a super-resolution image. The acquired super-resolution image shows a lateral and an axial sub-diffraction resolution and demonstrates ultrafine striations with widths less than 70 nm that are not evident by conventional confocal microscopy. The striations appear to be related to nebulin thin filament binding protein. This newly developed imaging system is cutting edge for its high resolution and localization as well its simplicity and convenience.
Date: December 2010
Creator: Akel, Amal
System: The UNT Digital Library
Determination of the Optimal Number of Strata for Bias Reduction in Propensity Score Matching. (open access)

Determination of the Optimal Number of Strata for Bias Reduction in Propensity Score Matching.

Previous research implementing stratification on the propensity score has generally relied on using five strata, based on prior theoretical groundwork and minimal empirical evidence as to the suitability of quintiles to adequately reduce bias in all cases and across all sample sizes. This study investigates bias reduction across varying number of strata and sample sizes via a large-scale simulation to determine the adequacy of quintiles for bias reduction under all conditions. Sample sizes ranged from 100 to 50,000 and strata from 3 to 20. Both the percentage of bias reduction and the standardized selection bias were examined. The results show that while the particular covariates in the simulation met certain criteria with five strata that greater bias reduction could be achieved by increasing the number of strata, especially with larger sample sizes. Simulation code written in R is included.
Date: May 2010
Creator: Akers, Allen
System: The UNT Digital Library
Routine Leisure Activities and Adolescent Marijuana Use: Moderating Effects of Family Structure (open access)

Routine Leisure Activities and Adolescent Marijuana Use: Moderating Effects of Family Structure

How adolescents spend their time is a crucial predictor of their engagement in delinquency. Activities with peers away from direct supervision of adults are of concern as more opportunities and motivation to use marijuana exist in such situations. However, adolescents may vary in their propensity to use marijuana when faced the opportunity. Especially adolescents living with a single parent may have a higher propensity compared to those from two-parent households to use marijuana due to reduced parental monitoring and increased peer attachment. This thesis investigates the moderating effects of family structure on the routine leisure activities and adolescent marijuana use relationship, using data from Monitoring the Future Study 2007, 12th Grade Survey. The results provide partial support for the moderating effects.
Date: May 2010
Creator: Aksu, Gokhan
System: The UNT Digital Library
L'emploi variable des signes diacritiques dans le français tchaté : une étude variationniste en temps apparent . (open access)

L'emploi variable des signes diacritiques dans le français tchaté : une étude variationniste en temps apparent .

After providing an historical overview of the French spelling system and orthographic variation, this study analyzes selected internal (i.e., linguistic) factors and one external (i.e., social) factor that can influence the use of diacritics in online French-language chat sessions. From a corpus of synchronous computer-mediated communication, 3,855 tokens of graphemes capable of bearing diacritics were coded with the following scheme: Letter, Diacritic, Grapheme (i.e., Letter and Diacritic combined), Date of Participation, and Age Group of Participant. A multivariate (VARBRUL) analysis determined that Grapheme exerts the most influence on variation.
Date: May 2010
Creator: Al-Rashdan, Omar
System: The UNT Digital Library
Faculty Members' Readiness for E-learning in the College of Basic Education in Kuwait (open access)

Faculty Members' Readiness for E-learning in the College of Basic Education in Kuwait

E-learning exposes students and instructors to different learning models such as constructivism rather than the traditional learning. E-learning as a part of today's technology has proven that it is appropriate for most students' mentalities and is a mind tool which promotes different learning models, such as problem solving strategy, collaborative learning, and critical thinking. The Public Authority for Applied Education and Training (PAAET) in Kuwait consists of more than 10 academic colleges with a total number of 120 faculty members. The College of Basic Education (CBE) is one of them. The implementation of e-learning at the College of Basic Education requires that all the learning community members, instructors and students, understand that an e-learning course is like a learning community with the privilege of sharing knowledge, opinions, experiences related to class subject, and productive outcomes that are beneficial to this learning community. This study indentified the statistically significant differences in demographic characteristics of e-learning adopters and non-adopters among faculty members at CBE, examining faculty members' attitudes and skills toward e-learning readiness. The study will explore perceived barriers that face e-learning at CBE. Applying the Rogers diffusion of innovation theory, the influence of 4 factors was examined regarding faculty readiness for …
Date: August 2010
Creator: Alajmi, Mohammed
System: The UNT Digital Library
Measurement of Single Spin Asymmetries in Semi-Inclusive Deep Inelastic Scattering Reaction n↑ ( e,e' pi{sup +}) X at Jefferson Lab (open access)

Measurement of Single Spin Asymmetries in Semi-Inclusive Deep Inelastic Scattering Reaction n↑ ( e,e' pi{sup +}) X at Jefferson Lab

What constitutes the spin of the nucleon? The answer to this question is still not completely understood. Although we know the longitudinal quark spin content very well, the data on the transverse quark spin content of the nucleon is still very sparse. Semi-inclusive Deep Inelastic Scattering (SIDIS) using transversely polarized targets provide crucial information on this aspect. The data that is currently available was taken with proton and deuteron targets. The E06-010 experiment was performed at Jefferson Lab in Hall-A to measure the single spin asymmetries in the SIDIS reaction n↑(e, e′π{sup ±}/K{sup ±})X using transversely polarized {sup 3}He target. The experiment used the continuous electron beam provided by the CEBAF accelerator with a beam energy of 5.9 GeV. Hadrons were detected in a high-resolution spectrometer in coincidence with the scattered electrons detected by the BigBite spectrometer. The kinematic coverage focuses on the valence quark region, x = 0.19 to 0.34, at Q{sup 2} = 1.77 to 2.73 (GeV/c){sup 2}. This is the first measurement on a neutron target. The data from this experiment, when combined with the world data on the proton and the deuteron, will provide constraints on the transversity and Sivers distribution functions on both the u …
Date: June 1, 2010
Creator: Allada, Kalyan
System: The UNT Digital Library
Family Sex Talk: Analyzing the Influence of Family Communication Patterns on Parent and Late Adolescent's Sex Conversations (open access)

Family Sex Talk: Analyzing the Influence of Family Communication Patterns on Parent and Late Adolescent's Sex Conversations

Family communication has the potential to affect a variety of youth behavioral outcomes including adolescent sexual risk behavior. Within chapter 1, I present past literature on adolescent sexual risk behaviors, family communication patterns, and the gaps associated with those areas. In chapter 2, I review previous literature on adolescent sexual risk behavior, parent-child communication and family communication patterns. In chapter 3, I present the method which includes a description of the participants, procedures, measures, and data analysis used. In Chapter 4, I present the results of the study. According to the results of the study, father-child communication is not a better predictor of adolescent sexual risk behavior. A higher quantity of parent-child communication does not lead to less adolescent sexual risk behavior. Participants with a pluralistic family type do significantly differ from laissez-faire and protective family types in regards to levels of parent-child communication. Participants with a consensual family type do have significantly higher levels of parent-child communication in comparison to laissez-faire family types, but not protective family types. Finally, in chapter 5, I present the discussion with a review of previous research (consistent or inconsistent with the current findings), limitations and conclusions for the current study.
Date: August 2010
Creator: Allen, Evette L.
System: The UNT Digital Library
The Works for Clarinet Commissioned by the Concours International d'Exécution Musicale de Genève: A Critical Survey and Performance Guide (open access)

The Works for Clarinet Commissioned by the Concours International d'Exécution Musicale de Genève: A Critical Survey and Performance Guide

Beginning in 1939, the Concours International d'Exécution Musicale de Genève (CIEM; Geneva International Music Competition) is unique among international music competitions in its multidisciplinary approach. To date, fifteen works have been commissioned for clarinet for the years in which the clarinet was involved. The most well-known of these works is the unaccompanied work by Heinrich Sutermeister, Capriccio for Solo Clarinet in A, written in 1946 for the 1947 competition. This work is a staple in the unaccompanied clarinet repertoire. However, the other fourteen works commissioned for the competition are little known and to date no document has been prepared that examines each of these works in the context of the competition and clarinet literature. While perhaps less notable, works were also commissioned for a sight reading portion of the competition for many of the years in which the clarinet was a discipline chosen for the competition, two of which were published. These works are examined as well. This survey provides a critical, analytical, historical, performance-related and biographical review of the published and unpublished works commissioned for the clarinet by CIEM. The composers, competitors and the significance of these works and winners in the clarinet literature and history are included. A …
Date: August 2010
Creator: Allgeier, Anthony Joseph, III
System: The UNT Digital Library
Effects of Suspended Multi-Walled Carbon Nanotubes on Daphnid Growth and Reproduction (open access)

Effects of Suspended Multi-Walled Carbon Nanotubes on Daphnid Growth and Reproduction

Multi-walled carbon nanotube aggregates can be suspended in the aqueous phase by natural organic matter. These aggregates are ingested by filter feeding zooplankton. Ingested aggregates result in decreased growth and decreased reproduction. These effects may be caused by reduction in energy input from normal feeding behavior. pH alters natural organic matter structure through changes in electrostatic repulsion. Altered natural organic matter structure changes multi-walled carbon nanotube aggregate size. This size variation with variation in pH is significant, but not large enough a change in size to alter toxicity, as the aggregate size range remains well within the particle size selection of the organisms.
Date: May 2010
Creator: Alloy, Matthew Michael
System: The UNT Digital Library
Overgeneral Memory and Posttraumatic Stress Disorder in Adults Exposed to Family Violence (open access)

Overgeneral Memory and Posttraumatic Stress Disorder in Adults Exposed to Family Violence

Childhood exposure to familial violence increases risk for adult pathology, namely posttraumatic stress disorder (PTSD) and depression. Primary PTSD symptoms of hyperarousal and avoidance are implicated in overgeneral memory (OGM) theory in prior research. Individuals with trauma history tend to report OGMs, or non-specific autobiographical memories, perhaps to avoid unpleasant arousal elicited by recalling specific events. OGM, PTSD, depression, and arousal were assessed in adults with and without familial violence history. Arousal was measured via galvanic skin response (GSR) during an autobiographical memory task (AMT), requiring memory recall in response to emotionally-valenced cue words. Familial violence history was linked to higher incidence of PTSD symptoms. Childhood psychological violence was predictive of adult PTSD. Rates of depression, OGM, and arousal did not significantly vary by violence history. Significant gender differences were found relating to type of violence exposure and adult functioning. Research limitations, clinical implications, and future research suggestions are discussed.
Date: May 2010
Creator: Amador, Amy R.
System: The UNT Digital Library
A search for $ZH\rightarrow \mu\mu b \bar{b}$ production at the Tevatron (open access)

A search for $ZH\rightarrow \mu\mu b \bar{b}$ production at the Tevatron

The Standard Model describes with a very good accuracy all interactions of the, so far, known elementary particles. However the Higgs mechanism, which gives rise to the observed mass of these particles, has not yet been confirmed. The Higgs particle has not yet been observed, and the observation or exclusion is an important test of the Standard Model. The Standard Model does not predict the mass of the Higgs particle, however it does impose some limits on the range in which this mass can lie. In direct searches a Higgs with a mass smaller than 114.4 GeV and within 162 GeV and 166 GeV has been excluded at 95% CL at the LEP and the Tevatron colliders. The analysis presented in this thesis is aimed to search for the ZH → μμb$\bar{b}$ events in 3.1 fb<sup>-1</sup> of data collected with the DØ detector in p$\bar{p}$ collisions at √s = 1.96 TeV.
Date: April 20, 2010
Creator: Ancu, Lucian-Stefan
System: The UNT Digital Library
Comparing Indices of Happiness during Teaching Interactions (open access)

Comparing Indices of Happiness during Teaching Interactions

The measurement of happiness has received increasing attention in behavior analytic literature. Happiness in individuals with developmental disabilities has been assessed by 1) counting a specific behavior, or 2) sampling constellations of behaviors. The purpose of this study was to examine the two approaches while observing nine child and teacher dyads at an autism treatment center. Results showed that, overall, a constellation of behaviors can yield similar patterns when compared to a specific behavior count. However, the affect of one person did not predict the affect of the other and similar instructional conditions did not predict affect either. The implications of these results and future directions are discussed.
Date: May 2010
Creator: Anderson, Claire Therese
System: The UNT Digital Library
Measurement of muon neutrino and antineutrino induced single neutral pion production cross sections (open access)

Measurement of muon neutrino and antineutrino induced single neutral pion production cross sections

Elucidating the nature of neutrino oscillation continues to be a goal in the vanguard of the efforts of physics experiment. As neutrino oscillation searches seek an increasingly elusive signal, a thorough understanding of the possible backgrounds becomes ever more important. Measurements of neutrino-nucleus interaction cross sections are key to this understanding. Searches for {nu}{sub {mu}} {yields} {nu}{sub e} oscillation - a channel that may yield insight into the vanishingly small mixing parameter {theta}{sub 13}, CP violation, and the neutrino mass hierarchy - are particularly susceptible to contamination from neutral current single {pi}{sup 0} (NC 1{pi}{sup 0}) production. Unfortunately, the available data concerning NC 1{pi}{sup 0} production are limited in scope and statistics. Without satisfactory constraints, theoretical models of NC 1{pi}{sup 0} production yield substantially differing predictions in the critical E{sub {nu}} {approx} 1 GeV regime. Additional investigation of this interaction can ameliorate the current deficiencies. The Mini Booster Neutrino Experiment (MiniBooNE) is a short-baseline neutrino oscillation search operating at the Fermi National Accelerator Laboratory (Fermilab). While the oscillation search is the principal charge of the MiniBooNE collaboration, the extensive data ({approx} 10{sup 6} neutrino events) offer a rich resource with which to conduct neutrino cross section measurements. This work concerns …
Date: December 1, 2010
Creator: Anderson, Colin & U., /Yale
System: The UNT Digital Library
The Creative Process in Cross-Influential Composition (open access)

The Creative Process in Cross-Influential Composition

This dissertation describes a compositional model rooted in cross-influential methodology between complementary musical compositions that share generative source material. In their simultaneous construction, two composition pairs presented challenges that influenced and mediated the other's development with respect to timbre, transposition, pitch material, effects processing, and form. A working prototype first provides a model that is later developed. The first work Thema is for piano alone, and the companion piece Am3ht is for piano and live computer processing via the graphical programming environment Max/MSP. Compositional processes used in the prototype solidify the cross-influential model, demanding flexibility and a dialectic approach. Ideas set forth in the prototype are then explored through a second pair of compositions rooted in cross-influential methodology. The first work Lusmore is scored for solo contrabass and Max/MSP. The second composition Knockgrafton is scored for string orchestra. The flexibility of the cross-influential model is revealed more fully through a discussion of each work's musical development. The utility of the cross-influential compositional model is discussed, particularly within higher academia.
Date: May 2010
Creator: Anderson, Jonathan Douglas
System: The UNT Digital Library
You are what you wear: The examination of fashion leadership and general leadership among African American and Caucasian American college students. (open access)

You are what you wear: The examination of fashion leadership and general leadership among African American and Caucasian American college students.

The purpose of this study was twofold. First, the study compared fashion personality characteristics and shopping behaviors of African-American and Caucasian-American college students. Secondly, this study examined characteristics of leadership in general, and fashion leadership specifically, on fashion personality characteristics. The fashion personality characteristics studied included fashion leadership, fashion involvement, shopping enjoyment, and fashion consciousness. The participants consisted of 268 African Americans and 239 Caucasian Americans from two universities in the United States. Ethnicity was found to be an influence on fashion personality characteristics and shopping behaviors in this study. African Americans in the sample were found to have higher levels of fashion personality characteristics and shopping behaviors than Caucasian Americans. Fashion leadership was found to be positively related to general leadership, fashion involvement, shopping enjoyment and fashion consciousness. General leadership was found to be positively related to fashion involvement, shopping enjoyment, fashion consciousness, academic classification level. However, there was no significant difference found between general leadership and age.
Date: May 2010
Creator: Angelo, Davette
System: The UNT Digital Library
Sensitization of Lanthanides and Organic-Based Phosphorescence via Energy Transfer and Heavy-Atom Effects (open access)

Sensitization of Lanthanides and Organic-Based Phosphorescence via Energy Transfer and Heavy-Atom Effects

The major topics discussed are the phosphorescence sensitization in the lanthanides via energy transfer and in the organics by heavy atom effects. The f-f transitions in lanthanides are parity forbidden and have weak molar extinction coefficients. Upon complexation with the ligand, ttrpy (4'-p-Tolyl-[2,2':6',2"]-terpyridine) the absorption takes place through the ligand and the excitation is transferred to the lanthanides, which in turn emit. This process is known as "sensitized luminescence." Bright red emission from europium and bright green emission from terbium complexes were observed. There is ongoing work on the making of OLEDs with neutral complexes of lanthanide hexafluoroacetyl acetonate/ttrpy, studied in this dissertation. Attempts to observe analogous energy transfer from the inorganic donor complexes of Au(I) thiocyanates were unsuccessful due to poor overlap of the emissions of these systems with the absorptions of Eu(III) and Tb(III). Photophysics of silver-aromatic complexes deals with the enhancement of phosphorescence in the aromatics. The heavy atom effect of the silver is responsible for this enhancement in phosphorescence. Aromatics such as naphthalene, perylene, anthracene and pyrene were involved in this study. Stern Volmer plots were studied by performing the quenching studies. The quenchers employed were both heavy metals such as silver and thallium and lighter …
Date: May 2010
Creator: Arvapally, Ravi K.
System: The UNT Digital Library
EEG, Alpha Waves and Coherence (open access)

EEG, Alpha Waves and Coherence

This thesis addresses some theoretical issues generated by the results of recent analysis of EEG time series proving the brain dynamics are driven by abrupt changes making them depart from the ordinary Poisson condition. These changes are renewal, unpredictable and non-ergodic. We refer to them as crucial events. How is it possible that this form of randomness be compatible with the generation of waves, for instance alpha waves, whose observation seems to suggest the opposite view the brain is characterized by surprisingly extended coherence? To shed light into this apparently irretrievable contradiction we propose a model based on a generalized form of Langevin equation under the influence of a periodic stimulus. We assume that there exist two different forms of time, a subjective form compatible with Poisson statistical physical and an objective form that is accessible to experimental observation. The transition from the former to the latter form is determined by the brain dynamics interpreted as emerging from the cooperative interaction among many units that, in the absence of cooperation would generate Poisson fluctuations. We call natural time the brain internal time and we make the assumption that in the natural time representation the time evolution of the EEG variable …
Date: May 2010
Creator: Ascolani, Gianluca
System: The UNT Digital Library
Measurement of the absolute v<sub>μ</sub>-CCQE cross section at the SciBooNE experiment (open access)

Measurement of the absolute v<sub>μ</sub>-CCQE cross section at the SciBooNE experiment

This thesis presents the measurement of the charged current quasi-elastic (CCQE) neutrino-nucleon cross section at neutrino energies around 1 GeV. This measurement has two main physical motivations. On one hand, the neutrino-nucleon interactions at few GeV is a region where existing old data are sparse and with low statistics. The current measurement populates low energy regions with higher statistics and precision than previous experiments. On the other hand, the CCQE interaction is the most useful interaction in neutrino oscillation experiments. The CCQE channel is used to measure the initial and final neutrino fluxes in order to determine the neutrino fraction that disappeared. The neutrino oscillation experiments work at low neutrino energies, so precise measurement of CCQE interactions are essential for flux measurements. The main goal of this thesis is to measure the CCQE absolute neutrino cross section from the SciBooNE data. The SciBar Booster Neutrino Experiment (SciBooNE) is a neutrino and anti-neutrino scattering off experiment. The neutrino energy spectrum works at energies around 1 GeV. SciBooNE was running from June 8th 2007 to August 18th 2008. In that period, the experiment collected a total of 2.65 x 10<sup>20</sup> protons on target (POT). This thesis has used full data collection in …
Date: July 1, 2010
Creator: Aunion, Jose Luis Alcaraz
System: The UNT Digital Library
The Role of Attachment in the Intergenerational Transmission of Abuse: From Childhood Victimization to Adult Re-Victimization and Distress (open access)

The Role of Attachment in the Intergenerational Transmission of Abuse: From Childhood Victimization to Adult Re-Victimization and Distress

Research indicates that victims of childhood abuse are at increased risk for transmitting violence in adulthood-a phenomenon known as the intergenerational transmission of abuse (ITA). Adult survivors of childhood victimization (i.e., child abuse or witnessed parental violence) are at increased risk for becoming abusive parents, perpetrators of intimate partner violence, and victims of intimate partner violence. The current study examined the latter form of ITA, in which a survivor of childhood victimization is re-victimized in adulthood by intimate partner violence. Attachment theory has been used to explain the ITA by positing that abuse is transmitted across generations via insecure attachment. The purpose of this study was to use structural equation modeling to test the attachment theory of ITA by examining the role of childhood and adult attachment in predicting re-victimization and symptoms of distress in adulthood. In the hypothesized model, childhood victimization by one's parents was hypothesized to predict adult intimate partner violence victimization through insecure attachment relationships in childhood (with one's parents) and adulthood (with one's partner). Furthermore, adult romantic attachment anxiety and attachment avoidance were hypothesized to predict different symptoms of distress. Self-report measures from 59 adult woman seeking services for intimate partner victimization at a domestic violence …
Date: December 2010
Creator: Austin, Aubrey A.
System: The UNT Digital Library
Testing CPT conservation using the NuMI neutrino beam with the MINOS experiment (open access)

Testing CPT conservation using the NuMI neutrino beam with the MINOS experiment

The MINOS experiment was designed to measure neutrino oscillation parameters with muon neutrinos. It achieves this by measuring the neutrino energy spectrum and flavor composition of the man-made NuMI neutrino beam 1km after the beam is formed and again after 735 km. By comparing the two spectra it is possible to measure the oscillation parameters. The NuMI beam is made up of 7.0%$\bar{v}$<sub>μ</sub>, which can be separated from the v<sub>μ</sub> because the MINOS detectors are magnetized. This makes it possible to study $\bar{v}$<sub>μ</sub> oscillations separately from those of muon neutrinos, and thereby test CPT invariance in the neutrino sector by determining the $\bar{v}$<sub>μ</sub> oscillation parameters and comparing them with those for v<sub>μ</sub>, although any unknown physics of the antineutrino would appear as a difference in oscillation parameters. Such a test has not been performed with beam $\bar{v}$<sub>μ</sub> before. It is also possible to produce an almost pure $\bar{v}$<sub>μ</sub> beam by reversing the current through the magnetic focusing horns of the NuMI beamline, thereby focusing negatively, instead of positively charged particles. This thesis describes the analysis of the 7% $\bar{v}$<sub>μ</sub> component of the forward horn current NuMI beam. The $\bar{v}$<sub>μ</sub> of a data sample of 3.2 x 10{sup 20} protons on …
Date: March 1, 2010
Creator: Auty, David John
System: The UNT Digital Library
A Spatially Explicit Environmental Health Surveillance Framework for Tick-Borne Diseases (open access)

A Spatially Explicit Environmental Health Surveillance Framework for Tick-Borne Diseases

In this paper, I will show how applying a spatially explicit context to an existing environmental health surveillance framework is vital for more complete surveillance of disease, and for disease prevention and intervention strategies. As a case study to test the viability of a spatial approach to this existing framework, the risk of human exposure to Lyme disease will be estimated. This spatially explicit framework divides the surveillance process into three components: hazard surveillance, exposure surveillance, and outcome surveillance. The components will be used both collectively and individually, to assess exposure risk to infected ticks. By utilizing all surveillance components, I will identify different areas of risk which would not have been identified otherwise. Hazard surveillance uses maximum entropy modeling and geographically weighted regression analysis to create spatial models that predict the geographic distribution of ticks in Texas. Exposure surveillance uses GIS methods to estimate the risk of human exposures to infected ticks, resulting in a map that predicts the likelihood of human-tick interactions across Texas, using LandScan 2008TM population data. Lastly, outcome surveillance uses kernel density estimation-based methods to describe and analyze the spatial patterns of tick-borne diseases, which results in a continuous map that reflects disease rates based …
Date: August 2010
Creator: Aviña, Aldo
System: The UNT Digital Library
Search for associated production of z and Higgs bosons in proton-antiproton collisions at 1.96 TeV (open access)

Search for associated production of z and Higgs bosons in proton-antiproton collisions at 1.96 TeV

We present a search for associated production of Z and Higgs bosons in 4.2 fb{sup -1} of {bar p}p collisions at {radical}s = 1.96 TeV, produced in RunII of the Tevatron and recorded by the D0 detector. The search is performed in events containing at least two muons and at least two jets. The ZH signal is distinguished from the expected backgrounds by means of multivariate classifiers known as random forests. Binned random forest output distributions are used in comparing the data to background-only and signal+background hypotheses. No excess is observed in the data, so we set upper limits on ZH production with a 95% confidence level.
Date: December 1, 2010
Creator: BackusMayes, John Alexander & /Washington U., Seattle
System: The UNT Digital Library
Comparing the Readability of Text Displays on Paper, E-Book Readers, and Small Screen Devices (open access)

Comparing the Readability of Text Displays on Paper, E-Book Readers, and Small Screen Devices

Science fiction has long promised the digitalization of books. Characters in films and television routinely check their palm-sized (or smaller) electronic displays for fast-scrolling information. However, this very technology, increasingly prevalent in today's world, has not been embraced universally. While the convenience of pocket-sized information pieces has the techno-savvy entranced, the general public still greets the advent of the e-book with a curious reluctance. This lack of enthusiasm seems strange in the face of the many advantages offered by the new medium - vastly superior storage capacity, searchability, portability, lower cost, and instantaneous access. This dissertation addresses the need for research examining the reading comprehension and the role emotional response plays in the perceived performance on e-document formats as compared to traditional paper format. This study compares the relative reading comprehension on three formats (Kindle, iTouch, and paper) and examines the relationship of subject's emotional response and relative technology exposure as factors that affect how the subject perceives they have performed on those formats. This study demonstrates that, for basic reading comprehension, the medium does not matter. Furthermore, it shows that, the more uncomfortable a person is with technology and expertise in the requested task (in this case, reading), the …
Date: May 2010
Creator: Baker, Rebecca Dawn
System: The UNT Digital Library