Digital Commons Network^™

Disaster Resilience As Communication Practice: Remembering And Forgetting Lessons From Past Disasters Through Practices That Prepare For The Next One, Rebecca M. Rice, Jody L. S. Jahn

Communication Studies Faculty Publications

Communities learn important lessons about their vulnerabilities from disasters. A crucial aspect of resilience is how communities apply past lessons to prepare for future events. We use a practice lens to examine how communities remember and forget lessons through everyday communication surrounding their preparedness activities. We analyze two cases of disaster preparedness in one community. The first site, a local Office of Emergency Management, adapted national policies to the community while also keeping local disaster lessons in mind (i.e. remembering lessons). The second site represented an intractable conflict between the U.S. Forest Service and a community group that inhibited the …

First-Principles Study Of High-Pressure Phase Stability And Superconductivity Of Bi4i4, Shiyu Deng, Xianqi Song, Quan Li, Yu Xie, Changfeng Chen, Yanming Ma

Physics & Astronomy Faculty Research

Bismuth iodide Bi4I4 exhibits intricate crystal structures and topological insulating states that are highly susceptible to influence by environments, making its physical properties highly tunable by external conditions. In this work, we study the evolution of structural and electronic properties of Bi4I4 at high pressure using an advanced structure search method in conjunction with first-principles calculations. Our results indicate that the most stable ambient-pressure monoclinic α−Bi4I4 phase in C2/m symmetry transforms to a trigonal P31c structure (ɛ−Bi4I4) at 8.4 GPa, then to a tetragonal P4/mmm structure (ζ−Bi4I4) above 16.6 GPa. In contrast to the semiconducting nature of ambient-pressure Bi4I4, the …

Cognitively Normal Women With Alzheimer’S Disease Proteinopathy Show Relative Preservation Of Memory But Not Of Hippocampal Volume, Jessica Z.K. Caldwell, Jeffrey L. Cummings, Sarah J. Banks, Sebastian Palmqvist, Oskar Hansson

School of Medicine Faculty Publications

Background: We examined interactive effects of sex, diagnosis, and cerebrospinal fluid (CSF) amyloid beta/phosphorylated tau ratio (Aβ/P-tau) on verbal memory and hippocampal volumes. Methods: We assessed 682 participants (350 women) from BioFINDER (250 cognitively normal [CN]; and 432 symptomatic: 186 subjective cognitive decline [SCD], 246 mild cognitive impairment [MCI]). General linear models evaluated effects of Alzheimer’s disease (AD) proteinopathy (CSF Aß/p-tau ratio), diagnosis, and sex on verbal memory (ADAS-cog 10-word recall), semantic fluency (animal naming fluency), visuospatial skills (cube copy), processing speed/attention functions (Symbol Digit Modalities Test and Trail Making Part A), and hippocampal volumes. Results: Amyloid-positive (Aβ/P-tau+) CN women …

Robust Cullin-Ring Ligase Function Is Established By A Multiplicity Of Poly-Ubiquitylation Pathways, Spencer Hill, Kurt Reichermeier, Daniel C. Scott, Lorena Samentar, Jasmin Coulombe-Huntington, Luisa Izzi, Xiaojing Tang, Rebeca Ibarra, Thierry Bertomeu, Annie Moridian, Michael J. Sweredoski, Nora Caberoy, Brenda A. Schulman, Frank Sicheri, Mike Tyers, Gary Kleiger

Life Sciences Faculty Research

The cullin-RING ligases (CRLs) form the major family of E3 ubiquitin ligases. The prototypic CRLs in yeast, called SCF enzymes, employ a single E2 enzyme, Cdc34, to build poly-ubiquitin chains required for degradation. In contrast, six different human E2 and E3 enzyme activities, including Cdc34 orthologs UBE2R1 and UBE2R2, appear to mediate SCF-catalyzed substrate polyubiquitylation in vitro. The combinatorial interplay of these enzymes raises questions about genetic buffering of SCFs in human cells and challenges the dogma that E3s alone determine substrate specificity. To enable the quantitative comparisons of SCF-dependent ubiquitylation reactions with physiological enzyme concentrations, mass spectrometry was employed …

Interpretable Deep Neural Network For Cancer Survival Analysis By Integrating Genomic And Clinical Data, Jie Hao, Youngsoon Kim, Tejaswini Mallavarapu, Jung Hun Oh, Mingon Kang

Computer Science Faculty Research

Background: Understanding the complex biological mechanisms of cancer patient survival using genomic and clinical data is vital, not only to develop new treatments for patients, but also to improve survival prediction. However, highly nonlinear and high-dimension, low-sample size (HDLSS) data cause computational challenges to applying conventional survival analysis. Results: We propose a novel biologically interpretable pathway-based sparse deep neural network, named Cox-PASNet, which integrates high-dimensional gene expression data and clinical data on a simple neural network architecture for survival analysis. Cox-PASNet is biologically interpretable where nodes in the neural network correspond to biological genes and pathways, while capturing the nonlinear …

An Analysis Of Energy Consumption And The Use Of Renewables For A Small Drinking Water Treatment Plant, Saria Bukhary, Jacimara Batista, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

One of the pressing issues currently faced by the water industry is incorporating sustainability considerations into design practice and reducing the carbon emissions of energy-intensive processes. Water treatment, an indispensable step for safeguarding public health, is an energy-intensive process. The purpose of this study was to analyze the energy consumption of an existing drinking water treatment plant (DWTP), then conduct a modeling study for using photovoltaics (PVs) to offset that energy consumption, and thus reduce emissions. The selected plant, located in southwestern United States, treats 0.425 m3 of groundwater per second by utilizing the processes of coagulation, filtration, and disinfection. …

Subglacial Meltwater Supported Aerobic Marine Habitats During Snowball Earth, Maxwell A. Lechte, Malcolm W. Wallace, Ashleig Van Smeerdijk Hooda, Weiqiang Li, Ganqing Jiang, Galen P. Halverson, Dan Asael, Stephanie L. Mccoll, Noah J. Planavsky

Geoscience Faculty Publications

The Earth’s most severe ice ages interrupted a crucial interval in eukaryotic evolution with widespread ice coverage during the Cryogenian Period (720 to 635 Ma). Aerobic eukaryotes must have survived the “Snowball Earth” glaciations, requiring the persistence of oxygenated marine habitats, yet evidence for these environments is lacking. We examine iron formations within globally distributed Cryogenian glacial successions to reconstruct the redox state of the synglacial oceans. Iron isotope ratios and cerium anomalies from a range of glaciomarine environments reveal pervasive anoxia in the ice-covered oceans but increasing oxidation with proximity to the ice shelf grounding line. We propose that …

Isolation Of Metrosideros (`Ohi`A) Taxa On O`Ahu Increases With Elevation And Extreme Environments, Elizabeth A. Stacy, Tomoko Sakishima, Heaven Tharp, Neil Snow

Life Sciences Faculty Research

Species radiations should be facilitated by short generation times and limited dispersal among discontinuous populations. Hawaii’s hyper-diverse, landscape-dominant tree, Metrosideros, is unique among the islands’ radiations for its massive populations that occur continuously over space and time within islands, its exceptional capacity for gene flow by both pollen and seed, and its extended life span (ca. >650 years). Metrosideros shows the greatest phenotypic and microsatellite DNA diversity on O`ahu, where taxa occur in tight sympatry or parapatry in mesic and montane wet forest on 2 volcanoes. We document the nonrandom distributions of 12 taxa (including unnamed morphotypes) along elevation gradients, …

An Assessment Of Generation Z’S Preferences For Guest-Facing Hotel Technologies, Jennifer Jaimes, Mehmet Erdem, Chih Chien Chen, Bill Doyle

Hospitality Faculty Research

Generation Z, also commonly described as Digital Natives, is a notable emerging market for hoteliers. Given the ever-evolving nature of the consumers, existing marketing strategies may not always be effective for incoming generational cohorts. This exploratory study submits that examining Generation Z members’ perceptions on guest-facing hotel technologies could yield useful information for new marketing strategies. The findings establish that guest-facing technologies is an important consideration for the members of Generation Z when selecting a hotel accommodation and they are willing to pay more for a hotel property that offers them. However, the level of perceived importance of such technologies …

Safety Of Endoscopic Retrograde Cholangiopancreatography (Ercp) In Pregnancy: A Systematic Review And Meta-Analysis, Mohamed Azab, Shishira Bharadwaj, Mahendran Jayaraj, Annie S. Hong, Pejman Solaimani, Mohamad Mubder, Hyeyoung Yeom, Ji Won Yoo, Michael L. Volk

School of Medicine Faculty Publications

Background/Aims: Endoscopic retrograde cholangiopancreatography (ERCP) is a technically challenging procedure rarely associated with severe postprocedure complications. Hormonal changes during pregnancy promote cholelithiasis, but there are limited clinical data available on the outcomes of ERCP in pregnant women. ERCP techniques without irradiation were recently introduced as potential alternative. We performed a systematic review and meta-analysis to assess the safety of ERCP in pregnancy and to compare outcomes of radiation versus nonradiation ERCP. Materials and Methods: A systematic search of PubMed, Medline/Ovid, Web of Science, and Google Scholar through April 18th, 2018 using PRISMA and MOOSE guidelines identified 27 studies reporting the …

Trade-Offs Between Survival And Reproduction In Starvation-Selected Drosophila Melanogaster, Tammara Beeghly

UNLV Theses, Dissertations, Professional Papers, and Capstones

Evolutionary outcomes are demonstrated by traits that affect an organism’s schedule of reproduction and survival. These life history traits are reflected in an organism’s physiology, development and behavior. Environmental changes, such as availability of nutritional resources, can profoundly affect evolutionary outcomes of individuals and populations. When shortages arise, there will be trade-offs in the allocation of resources, where one trait prevails at the expense of another.

In the laboratory, we can mimic conditions in nature and study the specific effects of the conditions that we re-create. In our case, over 100 generations of Drosophila melanogaster have been selected for starvation …

A Retrospective Survey Of Exercise Habits In Low-Income Female Senior Citizens, Kelly L. Bumgarner

UNLV Theses, Dissertations, Professional Papers, and Capstones

American adults spend at least 50% of their time sedentary with the most inactive demographic being low-income women over 60. This is detrimental because routine physical activity benefits for senior women include balancing hormones, maintaining bone mineral density, and decreasing the risk of breast cancer. Statements like “good exercise habits begin during youth; children should play sports to establish healthy habits they’ll continue throughout their lives” are common, but not clearly supported by literature. Objective: The purpose of this retrospective, cross-sectional study was to identify whether physical activity/exercise habits during youth and young adulthood predict old age physical activity/exercise habits …

Arbitrary High Order Finite Difference Methods With Applications To Wave Propagation Modeled By Maxwell's Equations, Min Chen

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation investigates two different mathematical models based on the time-domain Maxwell's equations: the Drude model for metamaterials and an equivalent Berenger's perfectly matched layer (PML) model. We develop both an explicit high order finite difference scheme and a compact implicit scheme to solve both models. We develop a systematic technique to prove stability and error estimate for both schemes. Extensive numerical results supporting our analysis are presented. To our best knowledge, our convergence theory and stability results are novel and provide the first error estimate for the high-order finite difference methods for Maxwell's equations.

Reconciling Incongruencies: Examining The Meaning And Influencing Factors Of Oncology Nurses' Professional Quality Of Life, Rebecca Lynne Boni

UNLV Theses, Dissertations, Professional Papers, and Capstones

Nurses often witness suffering and loss. These experiences are intrinsic to the practice of nursing and can exert a strong, cumulative effect on nurses’ professional quality of life (QOL). Stamm (2010b) conceptualizes professional QOL as a composite of compassion fatigue and compassion satisfaction. Inferior professional QOL has been linked to numerous negative healthcare outcomes. Oncology nurses are particularly vulnerable to compassion fatigue. The Professional Quality of Life Scale (ProQOL), created by Stamm (2009), is the current survey used to measure professional QOL, but it may not be specific enough for oncology nurses.

The purpose of this grounded theory study was …

On Improving Performance Of The Binary Logistic Regression Classifier, Michael Chang

UNLV Theses, Dissertations, Professional Papers, and Capstones

Logistic Regression, being both a predictive and an explanatory method, is one of the most commonly used statistical and machine learning method in almost all disciplines. There are many situations, however, when the accuracies of the fitted model are low for predicting either the success event or the failure event. Several statistical and machine learning approaches exist in the literature to handle these situations. This thesis presents several new approaches to improve the performance of the fitted model, and the proposed methods have been applied to real datasets.

Transformations of predictors is a common approach in fitting multiple linear and …

Uncovering The Women In Ocean’S Eight: Understanding The Trends Of The Women’S Movement With The Portrayals Of Women In Film, Elyssa Michelle Day

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study seeks for a better understanding of the correlations between major milestones in the women’s movement and how that is reflected onto the silver screen. With the rise of sexual assault allegations against prominent figures in Hollywood, and the growth of the #MeToo movement, we in turn are beginning to see an influx of films being released, and older films being rebooted, with an all-female led cast. One of those all-female film reboots is Ocean’s Eight, a film coming from a male-dominated trilogy and genre. Because of this correlation, the question of whether the narratives within Ocean’s Eight reinforce …

Empirical Justification For Supportive Other Involvement In Collegiate Athletes’ Mental Health Intervention, Elena Gavrilova

UNLV Theses, Dissertations, Professional Papers, and Capstones

Student-athletes have been identified to evidence similar or higher rates of mental health difficulties and lower levels of mental health engagement as compared with non-athlete peers. Along these lines, sport-specific mental health intervention has been justified by researchers, yet only one randomized clinical trial has been conducted in collegiate student-athletes who have been formally assessed for mental health disorders (i.e., a family behavior therapy as compared with traditional campus counseling as usual; Donohue et al., 2018a). Results of this outcome study demonstrated greater improvements for participants who received the family-based intervention up to 8-months post-randomization. In this clinical trial, the …

Community Exposure To Particulate Matter And Its Impact For Students And Residents Near A Construction Asphalt Plant: A Case Study, Aman Gebremariam Gebreselassie

UNLV Theses, Dissertations, Professional Papers, and Capstones

Particulate matter (PM) consists of various small particles in the atmosphere that has been associated with environmental health risk factors for many deadly diseases. PM2.5 is particulate matter 2.5 micrometers or less in diameter, PM10 is particulate matter 10 micrometers or less in diameter and are both respirable particles that can penetrate the lungs and increase risk of cardiovascular problems and respiratory illness, among other health issues. Exposure to particulate pollution in the environment tends to cause lost income from work absence, students’ absences from school, hospital admissions as well as emergency and doctor room visits.

Although asphalt plants are …

Galena Creek Bridge Structural Health Monitoring Instrumentation And Modeling, Leopold Falkensammer

UNLV Theses, Dissertations, Professional Papers, and Capstones

Structural health monitoring (SHM) of an instrumented structure provides numerous benefits when assessing the long-term condition of the structure against degradation, or the short-term condition after an extreme event, such as an earthquake. The Nevada Department of Transportation (NDOT) has an interest in expanding the use of SHM for such assessments. Accordingly, the objective of the current study is to develop and implement a permanent SHM system for the Galena Creek Bridge, the largest concrete cathedral arch bridge in the world, to monitor its response to routine traffic and seismic activity. Completed in 2012, the bridge connects Reno and Carson …

Performance Modeling Of Supercritical Carbon Dioxide Zigzag-Channel Printed Circuit Heat Exchangers, Katrine Birgitte Bennett

UNLV Theses, Dissertations, Professional Papers, and Capstones

Supercritical carbon dioxide (sCO2) is currently being studied as the working fluid in power producing Brayton cycles due to its excellent physical and thermodynamic properties, especially near the critical point. Printed circuit heat exchangers (PCHEs) are being considered for use as condensers and recuperators for this purpose due to their high strength and compact designs. Many experimental and numerical studies are being conducted to characterize and optimize sCO2 PCHE operation and develop correlations to describe their thermal-hydraulic performance. Additionally, a few experimental and numerical structural assessments of these PCHEs have been conducted, but all have been somewhat limited due to …

Disparities In Administrative Pediatric Asthma Prevalence In Clark County, Aaliyah Goodie

UNLV Theses, Dissertations, Professional Papers, and Capstones

Objective: Asthma is one of the most common chronic diseases affecting young children nationally and globally. Asthma affects more than 25 million people in the nation, of which 6

million are children. Lifetime asthma prevalence for children in Nevada is 11.5% (CDC, 2016). This is likely an underestimate due to a large undocumented Hispanic population. In Clark County School District (CCSD) during the 2016-2017 school year, 20,235 students (8%) listed asthma in school records as a health concern. Asthma burden varies by sociodemographic group with highest rates documented among Black/African American, Hispanic/Latino, and pediatric populations. The Centers for Disease Control …

Treatment Of Perchlorate And Multiple Oxyanions: Chemical And Biological Investigations, Mark Elkouz

UNLV Theses, Dissertations, Professional Papers, and Capstones

Groundwater contamination with oxyanions is an issue that must be addressed for environmental, ecological and societal reasons. Chemical and biological treatment methods of reduction are already known and practiced, but the simultaneous presence of multiple oxyanions can add complicating effects to treatment sequence and efficacy. This research was concerned with the investigation of the chemical reductive treatment of Cr(VI) using both calcium polysulfide (CaSx) and ferrous sulfate (FeSO4), and the biological reductive treatment of chlorate, Cr(VI), nitrate and perchlorate using multiple organic substrates. The chemical treatment phase consisted of initial jar tests, using CaSx and FeSO4, followed by a laboratory …

Consequences Of Math Anxiety And Stereotype Threat: An Intersectional Perspective, Jennifer E. John Buck

UNLV Theses, Dissertations, Professional Papers, and Capstones

Individuals with science, technology, engineering, and math (STEM) skills are highly valued for their contribution to the U.S. workforce and society. However, women and some people of color enter STEM fields at lesser rates than do White men. Math anxiety and stereotype threat have been found to cause math performance decrements for women and some people of color. Presently, it is not clear how math anxiety and stereotype threat might work together to dually influence math performance and subsequent STEM participation. The current study focuses on a diverse sample of 295 undergraduate students who were randomly assigned to one of …

Evaluating Parents Sociodemographic Factors And Childhood Vaccine Decisions, Mehret Girmay

UNLV Theses, Dissertations, Professional Papers, and Capstones

Vaccination is considered one of the most successful public health achievements of the 20th century. However, with increasing vaccine skepticism emerging over the past decades, there is a threat to the ongoing sustainment of vaccine coverage within all US communities. This study evaluated and compared parents’ sociodemographic factors associated with childhood vaccine decisions. This study is a secondary analysis of 893 parents/guardians, age 18-55 years with child(ren) < 7 years living in the U.S.

Predictive analysis was conducted using multinomial logistic regression modeling was used to examine vaccine decisions (accept, hesitant, and refuse) in relation to parents’ sociodemographic factors. Overall, (66.6%) of parents accepted recommended vaccines, while …

Lifting The Veil: Do Health Care Price Transparency Laws Actually Lower Costs?, Nora Michelle Irene Langendorf

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this research is to determine whether or not health care transparency laws, in the form of price transparency, lower the rate of increase paid out in health care expenditures in those states that have enacted these laws compared to those states that have not. By controlling for factors such as poverty, age, chronic illnesses, and income that may play a part in lowering or raising health care costs, the primary explanatory variable – health care price transparency laws – can determine if there is a strong relationship with the dependent variable (the rate of increase on health …

Uncovering New Mechanisms Of Cdc34 And Cullin-Ring Activity, Spencer Hill

UNLV Theses, Dissertations, Professional Papers, and Capstones

Ubiquitylation is a cellular regulatory system found in all eukaryotic cells, which has managed to find a role in most pathways imaginable. The system works fundamentally through the ligation of a small protein known as ubiquitin onto a substrate. Depending on the context of the ubiquitin ligation, the substrate can be directed towards a number of cellular fates, the best-studied being degradation of the substrate. While originally thought of as a signal for cellular disposal units to degrade aberrant proteins, we now know that ubiquitin plays a highly nuanced role in cellular epistasis, controlling everything from the cell cycle to …

Alkali-Silica Reactivity Of Mortars Containing Natural Pozzolan, Arash Kian

UNLV Theses, Dissertations, Professional Papers, and Capstones

Alkali-silica reactivity is one of the most recognized deleterious phenomena in Portland cement concrete resulting in cracks, spalling, and other deleterious mechanisms.

The aim of this study was (i) to assess the extent of reactivity of the aggregates, quarried from seven different sources, suspected of being conducive to ASR, and (ii) to compare the effectiveness of industrial (Class F fly ash) and natural pozzolans in mitigation of alkali-silica reactivity of the studied aggregates. To this end, seven aggregate sources, four natural pozzolan sources, and one source of Class F fly ash were used. ASTM Type V Portland cement was replaced …

Moisture Dynamics Of A Near-Surface Desert Soil, Yuan Luo

UNLV Theses, Dissertations, Professional Papers, and Capstones

Desert soils cover about one third of the Earth’s land surface. Despite their large extent, however, our understanding of desert soil hydraulic processes and properties is still rather limited. In particularly with respect to the near-surface (top centimeters) of the soil profile, which play a critical role for infiltration, redistribution and evapotranspiration of rainwater, the limiting resource for life in desert environments, but also hosts most of the biologic activity and controls runoff, erosion as well as the emission of dust (Nannipieri et al.,2003; Bradford et al.,1987). Additionally, deserts are ideal locations for electricity generation with solar energy using large-scale …

Development Of Natural Perlite Based Concrete For Sustainable Construction, Seyedmahmoud Motaharikarein

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study aimed to partially replace Portland Cement (PC) with environmentally friendly binders capable of improving the longevity of concrete. The new binders consisted of different proportions of natural pozzolan (perlite) with various fineness and particle size distributions. A step-by-step research program was designed to: (1) discover the optimum fineness of perlite powder and its optimum replacement level with cement; (2) investigate the rheological properties of the perlite-containing mixtures, and examine whether this binder can be used in selfconsolidating concrete; and (3) assess the weaknesses of the new binder, and improve its deficiencies by using nanomaterials such as nano-silica. The …

Design Of Efficient Carbon-Based Adsorbents For The Removal Of Organic And Inorganic Water Contaminants, Sayedeh Soroosh Mortazavian Dehkordi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Granular activated carbon (AC) and biochar (BC) are two carbon-based adsorbents commonly used for water and wastewater treatment. However, these adsorbents have drawbacks that suppress their aqueous contaminants removal efficiency. Their major disadvantages are that AC has low selectivity and reusability potential, and BC has a hydrophobic nature.

The scope of this dissertation is to enhance the performance of commonly-used carbon-based adsorbents for the removal of organic and inorganic water contaminants and to understand the interactive mechanism of contaminants’ ions/molecules with adsorbents. Hexavalent chromium (Cr(VI)) and trichloroethylene (TCE) are two types of inorganic and organic water contaminants, respectively, which are …