Digital Commons Network^™

Gamma And Generalized Gamma Distributions, Victor Hugo Jiménez Nava

Open Access Theses & Dissertations

We present the Generalized Gamma Distribution, study its properties and derive the estimators of the parameters. This distribution includes many standard forms, like: Gamma, Exponential, Weibull, Half Normal and others. Sum and ratios of independent generalized gamma lead to intractable forms. However approximation works well. In particular two-moment gamma and three moment normal approximations are shown to approximate the sum of k independent gamma as well as generalized gamma distributions.

Phospholipid Analysis In Trypanosoma Cruzi, Melissa Rashonda Harris

Open Access Theses & Dissertations

Chagas disease, caused by the flagellate protozoan Trypanosoma cruzi is one of the most endemic and deadly infectious diseases. T.cruzi is distributed throughout most of South and Central America, where it infects 12 to 19 million people, with an annual incidence of 561,000. Another 35 million are exposed to infection, 2 to 3 million people have clinical symptoms of chronic Chagas disease, and about 45,000 of these may die every year due to cardiac failure. In addition to the growing number of incidences in other countries the disease is an emerging infectious disease in the U.S due to the migration …

Ecology Of The Rock Rattlesnake, Crotalus Lepidus, In The Northern Chihuahuan Desert, Vicente Mata Silva

Open Access Theses & Dissertations

The Rock Rattlesnake, Crotalus lepidus is a small species that is found from southern Arizona, southern New Mexico, and southern Texas, in the U.S., into northern Mexico. To date, little is known about the ecology of this species. Ecological information is becoming desperately needed for supporting the conservation and protection of species living in fragile environments such as the Chihuahuan Desert amid current local and global threats (e.g., habitat destruction and modification, urban development, and climate change). Although rattlesnakes spend a significant amount of time underground while overwintering, little is known about the physiology and behavior of these organisms during …

Development And Evaluation Of A Personalized Normative Feedback Intervention For Hispanic Youth At High Risk Of Smoking, Holly Mata

Open Access Theses & Dissertations

Despite reductions in overall smoking rates, data show that adolescents continue to smoke at higher rates than adults and that adolescents living in the Texas-Mexico border area are more likely than their counterparts living elsewhere in Texas to smoke. While adult smoking in the Paso del Norte Region has decreased significantly over the past decade, area youth smoking rates exceed both state and national averages. Recent estimates report cigarette smoking among El Paso youth in the past month to be slightly more than 28% as compared with 21% among Texas youth participating in the 2009 statewide Youth Risk Behavior Survey …

Free Radical Stress-Induced Parkinsonian Lewy-Like Aggregation Prevented Through Polyphenolic Phytochemical Analog Intervention: Implications For Subcellular Trafficking And Neurodegenerative Disorders, Rituraj Pal

Open Access Theses & Dissertations

Protein disulfide isomerase (PDI), the chief endoplasmic reticulum (ER)-resident oxidoreductase chaperone, is known to catalyze the maturation of disulfide-bond-containing proteins primarily through oxidation-reduction and isomerization functions. The rate-determining step in the oxidative regeneration path of disulfide-bond-containing proteins generally couples chemical thiol-disulfide-exchange reactions to a physical conformational folding reaction. I have determined the impact of PDI and its subdomains on the rate-determining step in ribonuclease A folding and on the physical structure-forming step of select ER-processed proteins including RNase A. This was facilitated through application of a novel chemical tool to exclusively populate native-disulfide-containing intermediates in unstructured forms. The described biochemical …

Mixed-Signal Distributed Feature Extraction For Classification Of Wide-Band Acoustic Signals On Sensor Networks, Humberto Santacruz

Open Access Theses & Dissertations

This thesis proposes a distributed/collaborative scheme for the classification of wide-band acoustic events within the context wireless sensor networks (WSNs). The proposed method is characterized by a mixed-signal processing scheme for the extraction of feature vectors which reduces the processing, memory allocation, and power requirements of the sensor nodes. The mixed-signal scheme assumes that nodes have an analog frontend consisting of a microphone, a bandpass filter, a squaring element and an integrator. This chain of components produces an estimate of the energy over the frequency subband extracted by the filter. The WSN has the ability to form a distributed filter …

Molecular Mechanisms Of Poly [Adp-Ribose] Polymerase-1 In Hiv-1 Infection, Daniel Reyes

Open Access Theses & Dissertations

Poly (ADP-ribose) polymerase-1 (PARP-1) is a cellular enzyme involved in genome stability and transcriptional regulation. The role of this protein in HIV-1 infection is largely controversial. Some reports indicated a fundamental role of PARP-1 in HIV-1 DNA integration and results from other laboratories do not support these conclusions. An important characteristic in all these experiments is that the HIV-1 target cells that were used express, in addition to PARP-1, the functional homologue PARP-2. We evaluated the role of PARP-1 in the chicken B lymphoblastoid cell line DT40. These cells naturally lack PARP-2 and support the early steps of HIV infection. …

Relationships Between Central Obesity, Fructose Intake, And Non-Alcoholic Fatty Liver Disease In Overweight Hispanic Adolescents, Hector Reyes

Open Access Theses & Dissertations

Introduction: The purpose of this study was to evaluate whether central (visceral) fat measured as waist circumference and daily fructose intake were associated with measures of non-alcoholic fatty liver disease (NAFLD) in Hispanic overweight adolescents.

Methodology: Thirty four obese boys (n=15) and girls (n=19) between the ages of 13 and 18 years were measured for body composition, waist circumference, and dietary fructose intake. Fasting alanine (ALT) and aspartate (AST) aminotransferase levels in blood, ALT/AST ratio, and hepatic fat fraction (HFF) by magnetic resonance imaging were measured and used as surrogates for NAFLD. Pearson Product-Moment correlation analyses were used …

An Evolutionary Approach Based On Viral Replication For Solving Combinatorial Optimization Problems, Claudia Evangelina Valles Sosa

Open Access Theses & Dissertations

A new multi-objective evolutionary algorithm that mimics the way viruses replicate is presented. The purpose of viral replication is to allow the reproduction and survival of its kind. The algorithm is able to produce a large number of solutions to be evaluated by imitating the way viral replication and the infection process work. The well-known multi-objective redundancy allocation problem is used to show the performance of this new viral-based evolutionary approach. The algorithm considers the maximization of system reliability, the minimization of system cost, and the minimization of system weight to be optimized simultaneously. The solution to the multi-objective optimization …

Assessing The Measurement Invariance Of The Modern Homonegativity Scale, Daniel Hugo Romero

Open Access Theses & Dissertations

Lesbians and gay men experience psychological distress due to sexual prejudice. Variables that predict negative attitudes toward gay men and lesbians are masculinity, religious background, conservative political affiliation, lack of contact with gay men and lesbians, age, and the belief that homosexuality is a choice. However, one important variable that has demonstrated inconsistent results is the sex of the person holding the attitude. Many studies have examined and proposed reasons why there are sex differences related to attitudes toward gay men and lesbians, but none has taken into account whether attitude scales measure the same construct equally between males and …

Craving Effect Of Unintentional Smoking Cues In Antismoking Images In Light Smokers, Francisco Isaac Salgado-Garcia

Open Access Theses & Dissertations

Tobacco use is considered the single most preventable cause of disease, disability, and death in the nation. According to cue-reactivity models, environmental stimuli associated with smoking may elicit cravings in smokers. Antismoking advertisements, may also elicit cravings in smokers because of unintentional use of smoking cues, which may promote smoking maintenance and hinder quitting attempts. The purpose of this study is to assess if cue-reactivity elicits cravings in light and intermittent smokers and if impulsivity serves as a moderator. Data from 155 participants who reported smoking at least once in the past week to 10 cigarettes per day were collected. …

Perceptions Of Disabilities Amongst The Tarahumara In Northern Mexico, Carolyn Raynor Trussell

Open Access Theses & Dissertations

This research focuses on the perceptions of disability amongst the Tarahumara, known amongst themselves as the Rarámuri, in the Sierra Madre region of Northern Chihuahua. This population of individuals has typically lived in isolated areas in communities in the Sierra Madre where medical and specialized educational services were rare. The purpose of this study was to explore the perceptions, knowledge and beliefs related to disabilities, as well as the access and beliefs related to educational and medical services.

The study focused on the individual and the society to examine how bodily conceptions influence perceptions of others. The target group for …

Analysis Of Indoor And Outdoor Particulate Matter At Various Residences In The El Paso Region, Joseph Christopher Pinon

Open Access Theses & Dissertations

This thesis is a presentation of particulate matter data collected from February 2007 to June 2008. Personal environment monitors (PEM), which measured 7-day PM2.5 concentrations, had been deployed at 14 homes during the 2007 year and deployed in 16 different homes during the 2008 sampling year. Within each sampling year, sampling occurred for two one-week (7-day) periods during each season. In addition to PEM sampling, a tapered element oscillating microbalance (TEOM) continuous sampler had been deployed in both indoors and outdoors at one pre-selected household per week. Gravimetric, chemical, and black carbon analysis had been performed on the PEM PM2.5 …

Distributional Properties Of Inversions And Segmentation Algorithms For Rna Sequences, Sameera Dhananjaya Viswakula

Open Access Theses & Dissertations

Ribonucleic acid (RNA) is a long single stranded molecule made up of four types of nucleotide bases: Adenine (A), Cytosine(C), Guanine (G) and Uracil (U). It folds back on itself and forms C-G and A-U complementary base pairs. The set of such hydrogen-bonded pairs in an RNA molecule is called its secondary structure. Knowing the secondary structure of RNA is useful for understanding its biological function. Prediction of RNA secondary structure from the nucleotide sequence has been an important bioinformatics problem for over two decades.

The work in this thesis is motivated by the need to improve the secondary structure …

Computational Tool For Automated Large-Scale Gpiomic Analysis, Juan Clemente Aguilar

Open Access Theses & Dissertations

Liquid chromatography-tandem mass spectrometry (LC-MS/MS or MS/MS) is the most efficient tool today for the identification of glycosylphosphatidylinositol (GPI) molecules. The amount of data produced in each MS/MS experiment is a major bottleneck in high-throughput GPIomic (the entire collection of free and protein-linked GPIs) projects. Efficient computational tools can significantly reduce the amount of time analyzing MS/MS data; however, at present the automatic interpretation of these data to annotate GPI structures is absent. We propose a library-based tool to identify GPI structures by matching fragment peaks in the spectra with data derived from a theoretical database of GPI structures that …

Drowning In The Depths Of Climate Change: An Exploration Of Polar Bear Rhetoric, Gloria Leticia Bebber

Open Access Theses & Dissertations

This study explored campaigns that used polar bears to bring awareness to the issue climate change. The study analyzed three environmental campaigns, two major corporations, and one non-profit organization. The campaigns were examined using a rhetorical criticism method. Findings show that although polar bears are symbolically a good representation of the effects of climate change, it is imperative to address the entire issue. The limitations that occurred during the study are addressed.

X-Ray Diffraction Studies Of Room And Intermediate Tempertaure Phases Of Phosphate Based Solid Acids, Kiran Vajrapu

Open Access Theses & Dissertations

In this work, the MH2PO4-type solid acids (where M= Cs, K, Rb) structure and properties are studied and their contribution towards fuel cell industry is understood. Some research groups have shown that, CsH2PO4 (CDP) and RbH2PO4 (RDP) shows sudden, several order of magnitude jumps in their proton conductivity at certain high temperatures.(31, 32) This so called superprotonic behavior of these compounds makes them a fuel cell electrolyte at elevated temperatures. (33) Most of the research groups working on two possible causes to get the reliable information for the high proton conductivity: polymorphic phase transition (Botez et al.,) and thermal dehydration …

Novel Photovoltaic Device For Targeted Drug Delivery, Sunny S. Ambure

Open Access Theses & Dissertations

Despite decades of research, progress in targeted drug delivery is relatively slow, hampered, in part, by the lack of appropriate mechanisms to deliver anticancer drugs selectively to tumor tissues. Systemic or oral administration can cause severe toxicity, which limits the therapeutic potential of anticancer drugs [1]. Therefore, the most important goal of drug delivery is to minimize the exposure of normal tissues to these drugs while maintaining their therapeutic concentration in tumors.

A photovoltaic cell (PV) is a system that converts lights into electricity as well as induces charge transfer by photovoltaic effect. Motivated by such unique property, we have …

The Effects Of Tai Chi On Balance And Peripheral Somatosensation In Older Adults With Type 2 Diabetes, Elisabeth Inge Cavegn

Open Access Theses & Dissertations

The increasing prevalence of type 2 diabetes in older adults is a major health concern, as older adults with diabetes have a two- to threefold risk of injurious falls and physical disability. Although studies on the effects of Tai Chi on balance and fall prevention have increased over the last two decades, the benefits for older adults with diabetes, specifically for those with impaired somatosensation in the lower extremities, are limited. Therefore, the purpose of this study was to investigate the effects of Tai Chi exercise on balance, peripheral somatosensation, and fitness in older adults with type 2 diabetes. The …

Altered Leptin Signaling On Dendritic Cells As A Potential Mechanism For Cancer Immunotherapy, Lorena Y. De Los Santos

Open Access Theses & Dissertations

Leptin is a pleiotropic hormone synthesized primarily by white adipocytes and its receptors are expressed in a variety of tissues and cells such as in the hypothalamus and cells of the immune system. Multiple cell types can produce a considerable amount of leptin such as skeletal muscle, placenta, and osteoblasts to name a few and its synthesis has been shown to be regulated by sex hormones and a broad range of inflammatory mediators. Although leptin has been shown to directly affect immune response, we are interested in how leptin affects dendritic cell function and their ability to induce a proper …

An Analysis Of The Zone Of Proximal Development As A Practicable Learning Theory Of Organizational Culture In The Workplace, Patricia Ann Gonzalez

Open Access Theses & Dissertations

This study analyzes and tests Lev Vygotsky's theory of the Zone of Proximal Development (ZPD) as a practicable learning model of organizational culture in the workplace. The ZPD poses a possible clarifying theory of the individual internalization of organizational culture in the workplace that enhances current theories of organizational assimilation and learning. Qualitative methods were quantified to test this theory using five categories of organizational culture and a 4-stage model created by Roland Tharp and Ronald Gallimore presented in their book Rousing Minds to Life (1988) to organize a 30-question survey that was administered to a representative sample of employees …

Development Of A Web-Based Geographic Information System For Arctic Science, George Walker Johnson

Open Access Theses & Dissertations

Environmental science is a large field of study that requires the acquisition of data for decision making in solving environmental issues. Leveraging desktop geographic information systems (GIS) and web-based GIS (WebGIS) systems for assisting in the problem solving processes can benefit both the research community and policy makers for decision making activities. Ensuring interoperability between desktop, web, and server GIS is essential for maximizing access, sharing and manipulation of data. Interoperability is maximized through the adoption of best practices, use of open standards, and utilization of Spatial Data Infrastructures (SDI). While many of the interoperability challenges such as infrastructure, data …

Comparison Of Two Environmental Health Education Methods To Reduce Exposure To Residential Pesticides In Hispanic, Patricia M. Juarez-Carrillo

Open Access Theses & Dissertations

ABSTRACT

Exposure to pesticides is associated with adverse health outcomes including poisonings, short-term signs and symptoms, and long-term adverse health outcomes including developmental and cognitive impairments, certain types of cancer, and damages to the endocrine, nervous, and reproductive systems. This study tested two educational methods aimed to help Hispanic, Spanish-speaking mothers living in the U.S.-México border make informed decisions about pesticides applied in their homes. 230 women were randomly allocated to a) a small group talk, b) a graphic booklet, or c) a control group. The outcomes were the knowledge level about the risks of pesticides and the pest prevention …

Structural And Functional Investigation Of Φ-El-Chaperonin Mediated Protein Folding, Sudheer Kumar Molugu

Open Access Theses & Dissertations

Chaperonins are ubiquitous, sequence related protein complexes that aid in the folding of nascent and misfolded polypeptides in an ATP driven pathway. Recently a GroEL-like, 860 kilo Dalton chaperonin protein complex was identified and isolated from the bacteriophage EL, a virus that infects the Gram-negative bacterium Pseudomonas aeruginosa. The bacteriophage EL contains 201 predicted open reading frames and is the only known phage that encodes for its own chaperonin known as Φ-EL-chaperonin.

To understand the importance of Φ-EL-chaperonin in phage EL life cycle, the recombinant Φ-EL-chaperonin protein was expressed in Escherichia coli (E. coli) purified to homogeneity and the structure …

Bioprinting Oxygen Releasing Microparticles For Improved Cell Tissue Viability, Daniel Reyna

Open Access Theses & Dissertations

A major challenge in regenerative medicine/tissue engineering is the difficulty of providing adequate oxygen to all cells within implanted engineered tissues before full vascularization is achieved. To overcome this limitation, a variety of oxygen-releasing particles have been developed to improve cell and tissue survival. However, most of these particles are used in random mixtures within scaffolding materials, which usually leads to an uneven distribution of oxygen in bioengineered tissues. An ideal oxygen supply requires a precise depositing control of oxygen-releasing particles in scaffolds. Cell bioprinting is a novel tissue fabrication approach, in which the bio-printer can be programmed to deposit …

The Role Of Perceptual Processes In The Use Of And Willingness To Use Professional Health Care Services, Luis Omar Rivera

Open Access Theses & Dissertations

To better address ethnic health disparities, it is imperative that we understand the psychological processes that shape people's use of and willingness to use professional health care services. The current research proposes and tests a model in which people's attentional orientation toward context discourages them from seeking professional health care services because (a) attentional orientation toward context encourages people to attribute symptoms of illness to external/environmental factors and (b) attributing symptoms of illness to external/environmental factors is associated with less use of professional health care services. The results of two studies show mixed support for the proposed model. Consistent with …

The Exploratory Value Of Agent-Based Models In Social Science, Ricardo Andress Rivera

Open Access Theses & Dissertations

N/A

Algorithms For Training Large-Scale Linear Programming Support Vector Regression And Classification, Pablo Rivas Perea

Open Access Theses & Dissertations

The main contribution of this dissertation is the development of a method to train a Support Vector Regression (SVR) model for the large-scale case where the number of training samples supersedes the computational resources. The proposed scheme consists of posing the SVR problem entirely as a Linear Programming (LP) problem and on the development of a sequential optimization method based on variables decomposition, constraints decomposition, and the use of primal-dual interior point methods. Experimental results demonstrate that the proposed approach has comparable performance with other SV-based classifiers. Particularly, experiments demonstrate that as the problem size increases, the sparser the solution …

Identification And Characterization Of Fkbp52-Specific Inhibitors For The Treatment Of Prostate Cancer, Johanny Tonos De Leon

Open Access Theses & Dissertations

Steroid hormone receptors require the ordered assembly of various chaperone and cochaperone proteins in order to reach a functional state. The final stage in the receptor maturation process requires the formation of a mutimeric complex consisting of Hsp90 dimer, p23, and one of several large immunophilins. Studies conducted previously demonstrated that the large immunophilin FKBP52 acts to potentiate glucocorticoid, androgen, and progesterone receptor signaling pathways. The aim of these studies was to identify and characterize FKBP52-specific inhibitors that would not only serve as tools for the pharmacological analysis of FKBP52-receptor interactions, but may also lead to novel drugs with significant …

Causes And Consequences Of Changes In Algal Community Structure Of Arctic Tundra Ponds From Barrow, Alaska, Mariana Vargas Medrano

Open Access Theses & Dissertations

Algal communities in the Arctic are highly sensitive to environmental change, such as longer growing seasons and changes in ice cover. On the north slope of Alaska, ponds and lakes cover large portions of the total land area. We surveyed the periphytic algal communities in tundra ponds from Barrow, Alaska to assess environmental effects on their populations. Samples were collected in August 2008-10 from two main study areas: the IBP (the International Biological Program), which was also studied in 1970-71 but now is located near to human settlements, and the BEO (Barrow Environmental Observatory), which is within a protected area. …