Digital Commons Network^™

Investigation Of Proline Utilization A: Kinetic Analysis Of Substrate Channel-Blocking Mutants And Creation Of A Trifunctional Chimera Enzyme, Benjamin W. Arentson

Department of Biochemistry: Dissertations, Theses, and Student Research

Proline metabolism is known to be involved in many cellular processes such as cell signaling, cellular redox balance, and cell survival. One of the enzymes involved in proline catabolism, proline utilization A, plays a role in oxidizing proline to glutamate in a two-step oxidation pathway involving enzymes proline dehydrogenase (PRODH) and Δ¹-pyrroline-5-carboxylate dehydrogenase (P5CDH).

Intermediate P5C/GSA has been shown to use an intramolecular channel to move from the PRODH active site to the P5CDH active site in a phenomenon called substrate channeling. In this work, one of the main objectives was to learn more about the channel usage. …

Alginate Hydrogel As A Three-Dimensional Extracellular Matrix For In Vitro Models Of Development, Catherine Sargus-Patino

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Tissue engineering, involving the use of three-dimensional (3-D) scaffolds for cell and tissue culture, is a promising technique for establishing in vitro culture models that mimic in vivo environments. In vitro models present ethical and cost advantages over in vivo models, and allow for controlled, mechanistic studies on factors that regulate normal and abnormal tissue development. Alginate, a linear polysaccharide derived from brown algae, has properties that make it a favorable material as a 3-D extracellular matrix for in vitro cell and tissue models. After demonstrating alginate’s tunable physical and chemical properties with respect to gel formation, stiffness, and cellular …

Walleye And White Bass Recruitment In Southwest Nebraska Irrigation Reservoirs, Jason Andrew Deboer

School of Natural Resources: Dissertations, Theses, and Student Research

Walleye Sander vitreus and white bass Morone chrysops are among the most popular sportfish in the reservoirs of the Great Plains. Despite considerable effort by the Nebraska Game and Parks Commission stocking walleye and managing reservoirs for walleye and white bass, populations of walleye and white bass in southwest Nebraska reservoirs are dynamic, as erratic recruitment has led to “boom and bust” fisheries for these two species. We investigated 1) factors regulating walleye and white bass recruitment during an 18-year period at five reservoirs, and 2) walleye spawning ecology at two reservoirs that differ in their degree of environmental variability. …

Dna Barcoding Distinguishes Pest Species Of The Black Fly Genus Cnephia (Diptera: Simuliidae), I. M. Confitti, K. P. Pruess, A. Cywinska, T. O. Powers, D. C. Currie

Department of Entomology: Faculty Publications

Accurate species identification is essential for cost-effective pest control strategies. We tested the utility of COI barcodes for identifying members of the black fly genus Cnephia Enderlein (Diptera: Simuliidae). Our efforts focus on four Nearctic Cnephia species—Cnephia dacotensis (Dyar & Shannon), Cnephia eremities Shewell, Cnephia ornithophilia (Davies, Peterson & Wood), and Cnephia pecuarum (Riley)—the latter two being current or potential targets of biological control programs. We also analyzed one Palearctic species, Cnephia pallipes (Fries). Although Cnephia adults can be identified anatomically to species, control programs target the larval stage, which is difficult or impossible to distinguish morphologically. By using …

Relationships Between Body Roundness With Body Fat And Visceral Adipose Tissue Emerging From A New Geometrical Model, Diana M. Thomas, Carl Bredlau, Anja Bosy-Westphal, Manfred Mueller, Wei Shen, Dympna Gallagher, Yuna Maeda, Andrew Mcdougall, Courtney M. Peterson, Eric Ravussin, Steven B. Heymsfield

Department of Mathematics Faculty Scholarship and Creative Works

Objective To develop a new geometrical index that combines height, waist circumference (WC), and hip circumference (HC) and relate this index to total and visceral body fat. Design and Methods Subject data were pooled from three databases that contained demographic, anthropometric, dual energy X-ray absorptiometry (DXA) measured fat mass, and magnetic resonance imaging measured visceral adipose tissue (VAT) volume. Two elliptical models of the human body were developed. Body roundness was calculated from the model using a well-established constant arising from the theory. Regression models based on eccentricity and other variables were used to predict %body fat and %VAT. Results …

Assessing Protein Conformational Sampling Methods Based On Bivariate Lag-Distributions Of Backbone Angles, Mehdi Maadooliat, Xin Gao, Jianhua Z. Huang

Mathematics, Statistics and Computer Science Faculty Research and Publications

Despite considerable progress in the past decades, protein structure prediction remains one of the major unsolved problems in computational biology. Angular-sampling-based methods have been extensively studied recently due to their ability to capture the continuous conformational space of protein structures. The literature has focused on using a variety of parametric models of the sequential dependencies between angle pairs along the protein chains. In this article, we present a thorough review of angular-sampling-based methods by assessing three main questions: What is the best distribution type to model the protein angles? What is a reasonable number of components in a mixture model …

The Added Complications Of Climate Change: Understanding And Managing Biodiversity, Ecosystems, And Ecosystem Services Under Multiple Stressors., Amanda Staudt, Allison K. Leidner, Jennifer Howard, Kate A. Brauman, Jeffrey Dukes, Lara J. Hansen, Craig Paukert, John Sabo, Luis A. Solórzano

Department of Forestry & Natural Resources Faculty Publications

Ecosystems around the world are already threatened by land-use and land-cover change, extraction of natural resources, biological disturbances, and pollution. These environmental stressors have been the primary source of ecosystem degradation to date, and climate change is now exacerbating some of their effects. Ecosystems already under stress are likely to have more rapid and acute reactions to climate change; it is therefore useful to understand how multiple stresses will interact, especially as the magnitude of climate change increases. Understanding these interactions could be critically important in the design of climate adaptation strategies, especially because actions taken by other sectors (eg …

Another Look At Browzine, Angela Flenner

Against the Grain

No abstract provided.

Rheological Investigation Of The Shear Strength, Durability, And Recovery Of Alginate Rafts Formed By Antacid Medication In Varying Ph Environments, Brooke M. Elliott, Kathleen E. Steckbeck, Lisa R. Murray, Kendra Erk

School of Materials Engineering Faculty Publications

The mechanical response of alginate rafts formed by mixing liquid alginate antacid medication (Gaviscon® Extra Strength Liquid Antacid) with acidic solutions was investigated by deforming isolated rafts in a shear rheometer. As rafts were deformed to varying magnitudes of applied strain, rheological parameters were identified and related to the overall strength, durability, and recoverability of rafts formed at different pH (1.1 – 1.7) and aging conditions (0.5 – 4 hr). Rafts formed in the lowest acidity solutions (pH 1.4, 1.7) were elastically weak (G₀’ = 60, 42 Pa for un-aged raft) yet maintained their elasticity during applied …

Analysis Of Carbohydrate Storage Granules In The Diazotrophic Cyanobacterium Cyanothece Sp. Pcc 7822., David G. Welkie, Debby Sherman, William B. Chrisler, Galya Orr, Louis A. Sherman

Department of Biological Sciences Faculty Publications

The unicellular diazotrophic cyanobacteria of the genus Cyanothece demonstrate oscillations in nitrogenase activity and H2 production when grown under 12 h light–12 h dark cycles. We established that Cyanothece sp. PCC 7822 allows for the construction of knock-out mutants and our objective was to improve the growth characteristics of this strain and to identify the nature of the intracellular storage granules. We report the physiological and morphological effects of reduction in nitrate and phosphate concentrations in BG-11 media on this strain. We developed a series of BG-11-derived growth media and monitored batch culture growth, nitrogenase activity and nitrogenase-mediated hydrogen production, …

From The Reference Desk-Reviews Of Reference Titles, Tom Gilson

Against the Grain

No abstract provided.

Unique Microbial Communities Persist In Individual Cystic Fibrosis Patients Throughout A Clinical Exacerbation, Katherine E. Price, Thomas H. Hampton, Alex H. Gifford, Emily L. Dolben, Deborah A. Hogan, Hilary G. Morrison, Mitchell L. Sogin, George A. O’Tooled

Dartmouth Scholarship

Cystic fibrosis (CF) is caused by inherited mutations in the cystic fibrosis transmembrane conductance regulator gene and results in a lung environment that is highly conducive to polymicrobial infection. Over a lifetime, decreasing bacterial diversity and the presence of Pseudomonas aeruginosa in the lung are correlated with worsening lung disease. However, to date, no change in community diversity, overall microbial load or individual microbes has been shown to correlate with the onset of an acute exacerbation in CF patients. We followed 17 adult CF patients throughout the course of clinical exacerbation, treatment and recovery, using deep sequencing and quantitative PCR …

Pcaanalyser: A 2d-Image Analysis Based Module For Effective Determination Of Prostate Cancer Progression In 3d Culture, Md Tamjidul Hoque, Louisa C. E. Windus, Carrie J. Lovitt, Vicky M. Avery

Computer Science Faculty Publications

Three-dimensional (3D) in vitro cell based assays for Prostate Cancer (PCa) research are rapidly becoming the preferred alternative to that of conventional 2D monolayer cultures. 3D assays more precisely mimic the microenvironment found in vivo, and thus are ideally suited to evaluate compounds and their suitability for progression in the drug discovery pipeline. To achieve the desired high throughput needed for most screening programs, automated quantification of 3D cultures is required. Towards this end, this paper reports on the development of a prototype analysis module for an automated high-content-analysis (HCA) system, which allows for accurate and fast investigation of …

Biz Of Acq-Student Attitudes Toward Academic Use Of Ebooks, Beth E. Jacoby, Michelle Flinchbaugh

Against the Grain

No abstract provided.

Op Ed-Random Ramblings-How Special Are Special Collections?, Bob Holley

Against the Grain

No abstract provided.

Reinventing The Methods Journal: Increasing Reproducibility With Video Journals, Kira Henderson

Against the Grain

No abstract provided.

Oregon Trails-Books To Alaska, Thomas W. Leonhardt

Against the Grain

No abstract provided.

A Comparison Of Site Fidelity And Habitat Use Of Red Snapper (Lutjanus Campechanus) To Evaluate The Performance Of Two Artificial Reefs In South Texas Utilizing Acoustic Telemetry, Andres Garcia

Theses and Dissertations - UTB/UTPA

Evaluation of artificial reefs is becoming an increasingly important component of fisheries management. This is particularly true for the northwestern Gulf of Mexico where natural hard substrate is limited and 359 petroleum platforms are scheduled for removal in 2013 due to the “idle iron” policy. This study compared the performance of two artificial reef configurations off the south Texas coast, the Texas Clipper and South Padre Island Near Shore Reefs that differ in material, depth, and distance from shore, with respect to behavior of red snapper, Lutjanus campechanus, an important recreational and commercial species. Red snapper were implanted with depth …

The Effects Of A Red Tide, Karenia Brevis Episode On The Benthic Macroinvertebrate Communities Of South Padre Island, Texas, Liana Lerma

Theses and Dissertations - UTB/UTPA

South Padre Island, Texas has experienced increasing frequency of harmful algal blooms (Karenia brevis) since the 1900’s, many of which resulted in massive fishes kills. In addition, shorebirds and other terrestrial wildlife deaths have been linked to K. brevis blooms prompting investigations of potential pathways by which brevetoxins may be transmitted to higher trophic levels. The benthic macrofanual community inhabiting the swash zone of sandy beaches consists primarily of filter feeding invertebrates which may serve as toxin bioaccumulators to secondary consumers of both marine and terrestrial food webs. The first reported mass mortality of swash zone benthic macrofauna on the …

Decomposition Patterns And Nitrogen Dynamics Of Black Mangrove (Avicennia Germinans)Leaf Litter In Disturbed Estuaries Linked To The Lower Laguna Madre, Texas, Mario Alberto Marquez

Theses and Dissertations - UTB/UTPA

Estuaries are among the most productive aquatic systems in the world but are subject to both anthropogenic and natural disturbances. With increasing environmental concerns, efforts have become commonplace in assessing the status and trends of environmental conditions. In this study, an assessment of ecosystem status of various estuaries affected by different disturbances, was attempted through the examination of key functional processes such as leaf litter decomposition and nutrient dynamics during decay. Three estuaries located along the Brownsville Ship Channel near the southern terminus of the Lower Laguna Madre in Texas were studied. The overlying goal of this study was to …

Design And Configuration Of Laser Tweezers Microscopy For Force Measurements On Single Dna Molecules, Carlos Jeziel Gonzalez Banuelos

Theses and Dissertations - UTB/UTPA

In this study, a detailed description of the optical tweezers microscopy technique is presented, as well as the methodologies used to prepare the DNA molecule for mechanical measurements at the nanoscale. The main objective is to initiate and extend the experimental biophysical studies on the DNA-proteins interactions at the University of Texas at Brownsville (UTB). DNA-binding proteins control almost all aspects of cellular function, such as transcription; chromosome maintenance, replication and DNA repair depend on the interaction of proteins with DNA. In view of such an important role played by DNA–protein interactions, various techniques have evolved over the years to …

Mental Health, Sleep Quality, Drinking Motives, And Alcohol-Related Consequences: A Path-Analytic Model, Shannon R. Kenney, Andrew Lac, Joseph W. Labrie, Justin F. Hummer, Andy Pham

Psychological Science Faculty Works

Objective: Poor mental health, sleep problems, drinking motivations, and high-risk drinking are prevalent among college students. However, research designed to explicate the interrelationships among these health risk behaviors is lacking. This study was designed to assess the direct and indirect influences of poor mental health (a latent factor consisting of depression, anxiety, and stress) to alcohol use and alcohol-related consequences through the mediators of global sleep quality and drinking motives in a comprehensive model.

Method: Participants were 1,044 heavy-drinking college students (66.3% female) who completed online surveys.

Results: A hybrid structural equation model tested hypotheses involving relations leading from poor …

Sensing Charges Of The Ciona Intestinalis Voltage-Sensing Phosphatase, Carlos A. Villalba-Galea, Ludivine Frezza, Walter Sandtner, Francisco Bezanilla

School of Pharmacy Faculty Articles

Voltage control over enzymatic activity in voltage-sensitive phosphatases (VSPs) is conferred by a voltage-sensing domain (VSD) located in the N terminus. These VSDs are constituted by four putative transmembrane segments (S1 to S4) resembling those found in voltage-gated ion channels. The putative fourth segment (S4) of the VSD contains positive residues that likely function as voltage-sensing elements. To study in detail how these residues sense the plasma membrane potential, we have focused on five arginines in the S4 segment of the Ciona intestinalis VSP (Ci-VSP). After implementing a histidine scan, here we show that four arginine-to-histidine mutants, namely R223H to …

Timoshenko Beam Effects In Lateral-Mode Microcantilever-Based Sensors In Liquids, Joshua A. Schultz, Stephen M. Heinrich, Fabien Josse, Nicholas J. Nigro, Isabelle Dufour, Luke A. Beardslee, Oliver Brand

Civil and Environmental Engineering Faculty Research and Publications

Recent experimental and analytical research has shown that higher in-fluid quality factors (Q) are achieved by actuating microcantilevers in the lateral flexural mode, especially for microcantilevers having larger width-to-length ratios. However, experimental results show that for these geometries the resonant characteristics predicted by the existing analytical models differ from the measurements. A recently developed analytical model to more accurately predict the resonant behaviour of these devices in viscous fluids is described. The model incorporates viscous fluid effects via a Stokes-type fluid resistance assumption and `Timoshenko beam' effects (shear deformation and rotatory inertia). Unlike predictions based on Euler-Bernoulli beam …

Wrl Newsletter November 2013, Rebecca Seipp

WRL Newsletters

No abstract provided.

Genocide, And Its Definition As The "Partial Elimination Of A National Group", Marcelo Ferreira

Genocide Studies and Prevention: An International Journal

This paper is primarily about the crimes committed by Argentina’s last military dictatorship and whether these deserve the legal qualification of crimes against humanity or “genocide.” This question has consequences which go beyond the field of law and affect society and collective psychology through the reconstruction of historical memory. From this perspective, this paper argues that the definition of Genocide set forth in international law is directly applicable in Argentine national law. It also examines the different problems with the use of this term. Finally, it aims to reconstruct the figure of Genocide from the original interpretation of the works …

Personality Disorders And Health Problems Distinguish Suicide Attempters From Completers In A Direct Comparison, Lucas Giner, Hilario Blasco-Fontecilla, M. Mercedes Perez-Rodriguez, Rebeca Garcia-Nieto, Jose Giner, Julio A. Guija, Antonio Rico, Enrique Barrero, Maria Angeles Luna, Jose De Leon, Maria A. Oquendo, Enrique Baca-Garcia

Psychiatry Faculty Publications

Background

Whether suicide attempters and completers represent the same population evaluated at different points along a progression towards suicide death, overlapping populations, or completely different populations is a problem still unresolved.

Methods

446 Adult suicide attempters and knowledgeable collateral informants for 190 adult suicide probands were interviewed. Sociodemographic and clinical data was collected for both groups using semi-structured interviews and structured assessments. Univariate analyses and logistic regression models were conducted to explore the similarities and differences between suicide attempters and completers.

Results

Univariate analyses yielded significant differences in sociodemographics, recent life events, impulsivity, suicide intent, and distribution of Axis I …

Notes And New Distributional Records Of Invasive Ants (Hymenoptera: Formicidae) In The Southeastern United States, Joe A. Macgown, Heath Richter, Richard L. Brown

Midsouth Entomologist

The spread and establishment of alien species into new regions is becoming commonplace with increased global trade and a warming climate. Ants are among the most successful of these species due to their relatively small size and adaptability. The southeastern United States has been particularly susceptible to the introduction of alien ant species as a result of its geographic location and large number of shipping ports. A subset of these alien species is considered invasive based on their overall negative impacts to natural ecosystems and to humans. During recent years, several of these species have shown marked dispersal in the …

Why, How, And Where We’Re Going Next: A Multi-Institution Look At Data Management Service, Kiyomi D. Deards

University of Nebraska-Lincoln Libraries: Faculty Publications

This study compares the relationship of four university libraries with their institutions’ data management policies, services, resources, and plans for the future. It combines an examination of public documentation and services advertised by the universities and their libraries with interviews of librarians involved with data management. Four members of the Association of Public and Land- Grant Universities of similar size were selected for comparison: Iowa State University, Oklahoma State University, Kansas State University, and the University of Nebraska–Lincoln. The study identifies how and why campus collaborations were created and describes possible next steps for expanding or refining existing data management …

The Biology And Taxonomy Of Head And Body Lice: Implications For Louse-Borne Disease Prevention, Denise L. Bonilla, Lance A. Durden, Marina E. Eremeeva, Gregory A. Dasch

Harold W. Manter Laboratory of Parasitology: Library Materials

Sucking lice (Phthiraptera: Anoplura) are obligate blood-feeding ectoparasites of placental mammals including humans. Worldwide, more than 550 species have been described and many are specific to a particular host species of mammal. Three taxa uniquely parasitize humans: the head louse, body louse, and crab (pubic) louse. The body louse, in particular, has epidemiological importance because it is a vector of the causative agents of three important human diseases: epidemic typhus, trench fever, and louse-borne relapsing fever. Since the advent of antibiotics and more effective body louse control measures in the 1940s, these diseases have markedly diminished in incidence. However, due …