Physical Sciences and Mathematics Commons^™

Alamethicin In Lipid Bilayers: Combined Use Of X-Ray Scattering And Md Simulations, Jianjun Pan, D. Peter Tieleman, John F. Nagle, Norbert Kučerka, Prof. Stephanie Tristram-Nagle Ph.D.

John Copeland Nagle

We study fully hydrated bilayers of two di-monounsaturated phospholipids diC18:1PC (DOPC) and diC22:1PC with varying amounts of alamethicin (Alm). We combine the use of X-ray diffuse scattering and molecular dynamics simulations to determine the orientation of alamethicin in model lipids. Comparison of the experimental and simulated form factors shows that Alm helices are inserted transmembrane at high humidity and high concentrations, in agreement with earlier results. The X-ray scattering data and the MD simulations agree that membrane thickness changes very little up to 1/10 Alm/ DOPC. In contrast, the X-ray data indicate that the thicker diC22:1PC membrane thins with added …

Baby, This World Is Cruel, Nytesia S. Ross

Journal of Multicultural Affairs

This poem is about a woman's fear of bringing a child into this world.

Left And Right Ventricular Dyssynchrony And Strains From Cardiovascular Magnetic Resonance Feature Tracking Do Not Predict Deterioration Of Ventricular Function In Patients With Repaired Tetralogy Of Fallot, Linyuan Jing, Gregory J. Wehner, Jonathan D. Suever, Richard Charnigo, Sudad Alhadad, Evan Stearns, Dimitri Mojsejenko, Christopher M. Haggerty, Kelsey Hickey, Anne Marie Valente, Tal Geva, Andrew J. Powell, Brandon K. Fornwalt

Saha Cardiovascular Research Center Faculty Publications

Background: Patients with repaired tetralogy of Fallot (rTOF) suffer from progressive ventricular dysfunction decades after their surgical repair. We hypothesized that measures of ventricular strain and dyssynchrony would predict deterioration of ventricular function in patients with rTOF.

Methods: A database search identified all patients at a single institution with rTOF who underwent cardiovascular magnetic resonance (CMR) at least twice, > 6 months apart, without intervening surgical or catheter procedures. Seven primary predictors were derived from the first CMR using a custom feature tracking algorithm: left (LV), right (RV) and inter-ventricular dyssynchrony, LV and RV peak global circumferential strains, and LV and …

Stability And Kinetics Of Dna Pseudoknots: Formation Of T∗A•T Base-Triplets And Their Targeting Reactions, Calliste Steffensmeier

Theses & Dissertations

Pseudoknots have been found to play important roles in the biology of RNA. These stem-loop motifs are considered to be very compact and the targeting of their loops with complementary strands is accompanied with lower favorable free energy terms. We used a combination of spectroscopic (UV, CD and fluorescence), calorimetric (DSC, PPC and ITC) and kinetic (SPR) techniques to investigate: 1) Local base-triplet formation in pseudoknots; 2) energetic contributions for the association of pseudoknots with their complementary strands; and 3) the kinetic rates as a function of targeting strand length.

We investigated a set of DNA pseudoknots with sequence: d(TCTCT …

Institutional Animal Care And Use Committees: A Flawed Paradigm Or Work In Progress?, John P. Gluck, F. Barbara Orlans

John P. Gluck, PhD

In his challenging article, Steneck (1997) criticized the creation of the Institutional Animal Care and Use Committee (IACUC) system established by the 1985 amendments to the Animal Welfare Act. He saw the IACUC review and approval of biomedical and behavioral research with animals as an unnecessary "reassignment" of duties from existing animal care programs to IACUC committees. He argued that the committees are unable to do the work expected of them for basically three reasons: (a) the membership lacks the expertise in matters relevant to animal research and care, (b) there exists an inherent and disabling conflict of interest, and …

Quef And Quef-Like: Diverse Chemistries In A Common Fold, Adriana Bon Ramos

Dissertations and Theses

The tunneling fold (T-Fold) superfamily is a small superfamily of enzymes found in organisms encompassing all kingdoms of life. Seven members have been identified thus far. Despite sharing a common three-dimensional structure these enzymes perform very diverse chemistries.

QueF is a bacterial NADPH-dependent oxidoreductase that catalyzes the reduction of the nitrile group of 7-cyano-7-deazaguanine (preQ₀) to a primary amine (preQ₁) in the queuosine biosynthetic pathway. Previous work on this enzyme has revealed the mechanism of reaction but the cofactor binding residues remain unknown. The experiments discussed herein aim to elucidate the role of residues lysine 80, …

Developing Hyperpolarized Silicon Particles For In Vivo Mri Targeting Of Ovarian Cancer, Nicholas Whiting, Jingzhe Hu, Niki M. Zacharias, Ganesh L. R. Lokesh, David E. Volk, David G. Menter, Rajesha Rupaimoole, Rebecca Previs, Anil K. Sood, Pratip Bhattacharya

Nicholas Whiting

Inhibiting Androgen Receptor Nuclear Entry In Castration-Resistant Prostate Cancer, Julie A. Pollock, Suzanne E. Wardell, Alexander A. Parent, David B. Stagg, Stephanie J. Ellison, Holly M. Alley, Christina A. Chao, Scott A. Lawrence, James P. Stice, Ivan Spasojevic, Jennifer G. Baker, Sung Hoon Kim, Donald P. Mcdonnell, John A. Katzenellenbogen, John D. Norris

Chemistry Faculty Publications

Clinical resistance to the second-generation antiandrogen enzalutamide in castration resistant prostate cancer (CRPC), despite persistent androgen receptor (AR) activity in tumors, highlights the unmet medical need for next generation antagonists. We have identified and characterized tetra-aryl cyclobutanes (CBs) as a new class of competitive AR antagonists that exhibit a unique mechanism of action. These CBs are structurally distinct from current antiandrogens (hydroxyflutamide, bicalutamide, and enzalutamide), and inhibit AR-mediated gene expression, cell proliferation, and tumor growth in several models of CRPC. Conformational profiling revealed that CBs stabilize an AR conformation resembling an unliganded receptor. Using a variety of techniques, it was …

Analyzing Sports Training Data With Machine Learning Techniques, Rehana Mahfuz, Zeinab Mourad, Aly El Gamal

The Summer Undergraduate Research Fellowship (SURF) Symposium

In the sports industry, there has not been enough effort in analyzing the personalized monitoring data of athletes collected during training sessions. This research is an attempt to find meaningful patterns in the Purdue Women’s Soccer training data that could help the coach design more efficient training sessions. We are specifically interested in studying this problem as an unsupervised learning problem. Our initial attempt is to cluster the players as well as drills into groups using k-means, c-means and spectral clustering algorithms, combined with feature transformation and reduction steps. These basic algorithms serve as a benchmark to measure performance improvements …

Assembly Of Nucleic Acid-Based Nanoparticles By Gas-Liquid Segmented Flow Microfluidics, Matthew L. Capek, Ross Verheul, David H. Thompson

The Summer Undergraduate Research Fellowship (SURF) Symposium

The development of novel and efficient mixing methods is important for optimizing the efficiency of many biological and chemical processes. Tuning the physical and performance properties of nucleic acid-based nanoparticles is one such example known to be strongly affected by mixing efficiency. The characteristics of DNA nanoparticles (such as size, polydispersity, ζ-potential, and gel shift) are important to ensure their therapeutic potency, and new methods to optimize these characteristics are of significant importance to achieve the highest efficacy. In the present study, a simple segmented flow microfluidics system has been developed to augment mixing of pDNA/bPEI nanoparticles. This DNA and …

Diabetes Is Associated With Cerebrovascular But Not Alzheimer's Disease Neuropathology, Erin L. Abner, Peter T. Nelson, Richard J. Kryscio, Frederick A. Schmitt, David W. Fardo, Randall L. Woltjer, Nigel J. Cairns, Lei Yu, Hiroko H. Dodge, Chengjie Xiong, Kamal Masaki, Suzanne L. Tyas, David A. Bennett, Julie A. Schneider, Zoe Arvanitakis

Sanders-Brown Center on Aging Faculty Publications

INTRODUCTION: The relationship of diabetes to specific neuropathologic causes of dementia is incompletely understood.

METHODS: We used logistic regression to evaluate the association between diabetes and infarcts, Braak neurofibrillary tangle stage, and neuritic plaque score in 2365 autopsied persons. In a subset of >1300 persons with available cognitive data, we examined the association between diabetes and cognition using Poisson regression.

RESULTS: Diabetes increased odds of brain infarcts (odds ratio [OR] = 1.57, P < .0001), specifically lacunes (OR = 1.71, P < .0001), but not Alzheimer's disease neuropathology. Diabetes plus infarcts was associated with lower cognitive scores at end of life than infarcts or diabetes alone, and diabetes plus high level of Alzheimer's neuropathologic changes was associated with lower mini-mental state examination scores than the pathology alone.

DISCUSSION: This study supports the conclusions that diabetes increases the risk of cerebrovascular but not Alzheimer's disease pathology, and at least some of diabetes' relationship to …

Point Of Use Biosand Filters Of The Rural Dominican Republic, Kurtis Quamme

Theses and Dissertations

The point of use biosand filter (BSF) is used globally as a drinking water treatment solution. In this research, point of use BSFs were inoculated with active biosand from the Linnwood Drinking Water Treatment plant slow sand filter beds (Milwaukee, Wisconsin) and with sands collected from point of use filters operating in the Dominican Republic. These filters were maintained with varying source waters (surface water, groundwater, or tap water to simulate chlorination encountered in the field). The microbial community of filters with varied influents and biosand inoculum were analyzed quantitatively by sequencing and qPCR. Filter efficacy and microbial community were …

A Dose Distribution Study Of Uranyl Nitrate In Zebrafish Using Liquid Scintillation And Passivated Implanted Planar Silicon Detectors, Lee A. Alleman

Open Access Theses

Standard curves for a Perkin Elmer TriCarb 2800 liquid scintillation detector (LSC) and a Ludlum 3030p Passivated Implanted Planar Silicon detector have been developed and utilized for studying the dose distribution of depleted uranium (DU) within zebrafish. The DU source was crystallized uranyl nitrate (N2O8U•6H2O) solution, normally used for staining in electron microscopy with a manufactured average specific activity of 0.3 uCi/g. Zebrafish, both larvae and adults, were exposed to three different mass concentrations, dissected, dissolved and counted using an LSC. The counts were compared to the standard curve correlating the measured activity to that of the mass absorbed. It …

Manufacturer Perspectives On Content Transparency And Material Health In The Us Building Products Industry, Alexandra A. Muller

Open Access Theses

Flawed U.S. federal regulation of chemicals has resulted in a materials market that undervalues human and environmental health in favor of the more traditional attributes of price, performance and aesthetics. In the building products industry, global, dynamic supply chains and proprietary information concerns further complicate the task of assessing the material health of products.

Voluntary material health programs in the green building industry are intended to incentivize the manufacture and selection of safer products by getting companies to gather and assess ingredient, hazard and risk information from their supply chain. Building product manufacturers considered early adopters of the main material …

Pyrogenic Fuels Produced By Savanna Trees Can Engineer Humid Savannas, William J. Platt, Darin P. Ellair, Jean M. Huffman, Stephen E. Potts, Brian Beckage

College of Agriculture and Life Sciences Faculty Publications

Natural fires ignited by lightning strikes following droughts frequently are posited as the ecological mechanism maintaining discontinuous tree cover and grass-dominated ground layers in savannas. Such fires, however, may not reliably maintain humid savannas. We propose that savanna trees producing pyrogenic shed leaves might engineer fire characteristics, affecting ground-layer plants in ways that maintain humid savannas. We explored our hypothesis in a high-rainfall, frequently burned pine savanna in which the dominant tree, longleaf pine (Pinus palustris), produces resinous needles that become highly flammable when shed and dried. We postulated that pyrogenic needles should have much greater influence on fire characteristics …

Identifying Treatment Planning System Errors In Iroc-Houston Head And Neck Phantom Irradiations, James Kerns

Dissertations & Theses (Open Access)

Treatment Planning System (TPS) errors can affect large numbers of cancer patients receiving radiation therapy. Using an independent recalculation system, the Imaging and Radiation Oncology Core-Houston (IROC-H) can identify institutions that have not sufficiently modelled their linear accelerators in their TPS model. Linear accelerator point measurement data from IROC-H’s site visits was aggregated and analyzed from over 30 linear accelerator models. Dosimetrically similar models were combined to create “classes”. The class data was used to construct customized beam models in an independent treatment dose verification system (TVS). Approximately 200 head and neck phantom plans from 2012 to 2015 were recalculated …

Measurement Of The Electron Return Effect Using Presage Dosimeter, Gye Won Choi

Dissertations & Theses (Open Access)

MR-guided radiation therapy (MRgRT) provides benefits such as superior soft tissue contrast, no imaging dose, and functional imaging capacities, but it also has concerns to be addressed. The electron return effect (ERE) refers to dose enhancement at the interface between different media, caused when radiation is delivered in the magnetic field. The ERE poses clinical concerns in MRgRT because it significantly enhances the dose at interfaces, and the intensity and pattern of the dose enhancement depends on many factors. The ERE results in a complex pattern of dose enhancement over a three-dimensional (3D) volume around tissue interfaces inside the patient …

Evaluating The Risk To Ostomy Patients Working With Uranium Using The Icrp Biokinetic Model For The Gastrointestinal Tract, Sara Taylor

UNLV Theses, Dissertations, Professional Papers, and Capstones

The ICRP has published two biokinetic models providing a basis for radiation dose assessment due toradionuclides incorporated inside the gastrointestinal tract. These models are a sufficient tool to assess the committed dose equivalent for occupational exposures to workers assuming normal anatomy. The colostomy is becoming a more prevalent procedure. A colostomy permanently or temporarily bypasses a portion of colon to allow rest and healing. There are four different colostomies; ascending, transverse, descending and sigmoid and an ileostomy. As a patient’s strength returns, they can return to normal daily activities, including returning to work. Therefore, as an ostomy patient returns to …

Measurement Of Neutron Activation From A High Energy Varian Linear Accelerator, Timothy Thatcher

UNLV Theses, Dissertations, Professional Papers, and Capstones

Linear accelerators producing photons above 10 MeV may induce photonuclear reactions in high Z components of the accelerator. These liberated neutrons can then activate the structural components of the accelerator and other materials in the beam path through neutron capture reactions. The induced activity within the accelerator may contribute to additional dose to both patients and personnel. This project seeks to determine the total activity and activity per activated isotope following irradiation from a Varian medical linear accelerator at energies above 10 MeV. A Varian 21iX accelerator was used to irradiate a 30 cm x 30 cm x 20 cm …

Analysis Of The Intricacies Of Substrate Recognition Of High Mobility Group Proteins And Aminoacyl-Trna Synthetases Using Non-Cognate Substrates, Douglas Van Iverson Ii

Dissertations

The studies presented in section 1 (Chapters I-IV) focus on the design and development of nucleic acid four-way junctions (4WJs) to target a member of the high mobility group (HMG) proteins, the proinflammatory cytokine high mobility group box 1 protein (HMGB1). In the present study, hybrid PNA-DNA 4WJs based on a model DNA 4WJ were constructed to improve the thermal stability of 4WJs while maintaining strong binding affinity toward HMGB1. An electrophoretic mobility shift assay (EMSA) was used to examine the binding affinity of an isolated DNA binding domain of HMGB1, the HMGB1 b-box (HMGB1b), toward a set of PNA-DNA …

The Impact Of Patient Navigation On The Delivery Of Diagnostic Breast Cancer Care In The National Patient Navigation Research Program: A Prospective Meta-Analysis., Tracy A Battaglia, Julie S Darnell, Naomi Ko, Fred Snyder, Electra D Paskett, Kristen J Wells, Elizabeth M Whitley, Jennifer J Griggs, Anand Karnad, Heather Young, Victoria Warren-Mears, Melissa A Simon, Elizabeth Calhoun

Epidemiology Faculty Publications

Patient navigation is emerging as a standard in breast cancer care delivery, yet multi-site data on the impact of navigation at reducing delays along the continuum of care are lacking. The purpose of this study was to determine the effect of navigation on reaching diagnostic resolution at specific time points after an abnormal breast cancer screening test among a national sample. A prospective meta-analysis estimated the adjusted odds of achieving timely diagnostic resolution at 60, 180, and 365 days. Exploratory analyses were conducted on the pooled sample to identify which groups had the most benefit from navigation. Clinics from six …

An Automated Syringe Pump System For Improving The Reproducibility Of Dynamic Hyperpolarized Mri Phantoms, Harlee G. Harrison

Dissertations & Theses (Open Access)

AN AUTOMATED SYRINGE PUMP SYSTEM FOR IMPROVING THE REPRODUCIBILITY OF DYNAMIC HYPERPOLARIZED MRI PHANTOMS

Harlee Grace Harrison, B.S.

Advisory Professor: James Bankson, Ph.D.

Magnetic Resonance Imaging (MRI) is a powerful tool in the diagnosis of cancer due to its ability to provide good soft tissue contrast and image resolution without the use of ionizing radiation. The use of hyperpolarized pyruvate as a contrast agent for tumor metabolism during MR scans has the potential to provide information about tumor metabolism in vivo that is not available from traditional imaging measurements or any other method. Hyperpolarization is achieved through dynamic nuclear polarization. …

The Precarious Health Of Young Mexican American Men In South Texas, Cameron County Hispanic Cohort, 2004–2015, Gordon P. Watt, Kristina Vatcheva, Derek M. Griffith, Belinda M. Reininger, Laura Beretta, Michael Fallon, Joseph B. Mccormick, Susan P. Fisher-Hoch

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

Introduction

Hispanic men have higher rates of illness and death from various chronic conditions than do non-Hispanic men. We aimed to characterize the health of Mexican American men living on the US–Mexico border in South Texas and elucidate indications of chronic disease in young men.

Methods

We sampled all male participants from the Cameron County Hispanic Cohort, an ongoing population-based cohort of Mexican Americans in Brownsville, Texas. We calculated descriptive statistics and stratified the sample into 3 age groups to estimate the prevalence of sociodemographic, behavioral, and clinical factors by age group and evaluated differences between age groups.

Results

Obesity …

Accuracy And Precision Of Occlusal Contacts Of Stereolithographic Casts Mounted By Digital Interocclusal Registrations, Jason T. Krahenbuhl, Seok-Hwan Cho, Jon Patrick Irelan, Naveen K. Bansal

Mathematics, Statistics and Computer Science Faculty Research and Publications

Statement of problem

Little peer-reviewed information is available regarding the accuracy and precision of the occlusal contact reproduction of digitally mounted stereolithographic casts.

Purpose

The purpose of this in vitro study was to evaluate the accuracy and precision of occlusal contacts among stereolithographic casts mounted by digital occlusal registrations.

Material and methods

Four complete anatomic dentoforms were arbitrarily mounted on a semi-adjustable articulator in maximal intercuspal position and served as the 4 different simulated patients (SP). A total of 60 digital impressions and digital interocclusal registrations were made with a digital intraoral scanner to fabricate 15 sets of mounted stereolithographic …

Multipurpose Tenofovir Disoproxil Fumarate Electrospun Fibers For The Prevention Of Hiv-1 And Hsv-2 Infections., Kevin Tyo

Electronic Theses and Dissertations

Sexually transmitted infections affect hundreds of millions of worldwide. Both human immunodeficiency virus (HIV-1 and -2) and herpes simplex virus-2 (HSV-2) remain incurable, urging the development of new prevention strategies. While current prophylactic technologies are dependent on strict user adherence to achieve efficacy, there is a dearth of delivery vehicles that provide discreet and convenient administration, combined with prolonged-delivery of active agents. To address these needs, we created electrospun fibers (EFs) comprised of FDA-approved polymers, poly(lactic-co-glycolic acid) (PLGA) and poly(DL-lactide-co-ε-caprolactone) (PLCL), to provide sustained-release and in vitro protection against HIV-1 and HSV-2. PLGA and PLCL EFs, incorporating the antiretroviral, tenofovir …

Preterm Birth And Air Pollution: Critical Windows Of Exposure For Women With Asthma, Pauline Mendola, Maeve Wallace, Beom Seuk Hwang, Danping Liu, Candace Robledo, Tuija Männistö

School of Medicine Publications and Presentations

Background: Ambient air pollutants may increase preterm birth (PTB) risk, but critical exposure windows are uncertain. The interaction of asthma and pollutant exposure is rarely studied.

Objective: We sought to assess the interaction of maternal asthma and air pollutant exposures in relation to PTB risk.

Methods: Electronic medical records for 223,502 US deliveries were linked with modified Community Multiscale Air Quality model outputs. Logistic regression with generalized estimating equations estimated the odds ratio and 95% CIs for PTB on the basis of the interaction of maternal asthma and particulate matter with aerodynamic diameter of less than 2.5 microns and particulate …

Fuzzy Logic In Health Care Settings: Moral Math For Value-Laden Choices, Sarah Voss

Journal of Humanistic Mathematics

This essay is intended as an example of “moral math”, i.e., ideas culled from mathematics which can positively impact social behavior. Specifically, it combines fuzzy logic with the ethical decisions which hospital staff and others are sometimes forced to make about health care (e.g., euthanasia issues following Hurricane Katrina). The assumption is that such decisions involve value-laden choices which lend themselves to “fuzzy” or “smart” protocols. The article discusses the history of fuzzy logic – what it is, how it is used, and how it might be even better-used as a support basis for making difficult choices …

In-Season N Fertilization Strategies Using Active Sensors, Daniel Barker, John Sawyer

John E. Sawyer

The objectives of this project were to measure corn yield response to applied nitrogen (N) fertilizer based on active canopy sensing during the mid-vegetative corn growth stage (V10) and compare yield and N use efficiency between pre-plant N (PP-N), pre-plant + sensor N (PP+S-N), split N strategy (SNS), and rescue N strategy (RNS).

In-Season N Fertilization Strategies Using Active Sensors, Daniel Barker, John Sawyer

John E. Sawyer

The objectives of this project were to measure corn yield response to applied nitrogen (N) fertilizer based on active canopy sensing during the mid-vegetative corn growth stage (V10) and compare yield and N use efficiency between pre-plant N (PP-N), pre-plant + sensor N (PP+S-N), split N strategy (SNS), and rescue N strategy (RNS).

In-Season N Fertilization Strategies Using Active Sensors, Daniel Barker, John Sawyer

John E. Sawyer

The objectives of this project were to measure corn yield response to applied nitrogen (N) fertilizer based on active canopy sensing during the mid-vegetative corn growth stage (V10) and compare yield and N use efficiency between pre-plant N (PP-N), pre-plant + sensor N (PP+S-N), split N strategy (SNS), and rescue N strategy (RNS).