Life Sciences Commons^™

Tree Canopy Types Constrain Plant Distributions In Ponderosa Pine- Gambel Oak Forests, Northern Arizona, Scott R. Abella

Public Policy and Leadership Faculty Publications

Trees in many forests affect the soils and plants below their canopies. In current high-density southwestern ponderosa pine (Pinus ponderosa) forests, managers have opportunities to enhance multiple ecosystem values by manipulating tree density, distribution, and canopy cover through tree thinning. I performed a study in northern Arizona ponderosa pine-Gambel oak (Quercus gambelii) forests to measure the influences of tree canopy types on understory plant communities and soil properties. On ten 2.5-acre (1-ha) sites, I sampled five 43-ft2 (4-m2) plots below each of the following five canopy types: openings; single ponderosa pine; and Gambel oak single stems, dispersed clumps, and thickets. …

Keeping Fountain Grass Out Of The Mojave Desert, Curt Deuser

Lake Mead Science Symposium

Fountain Grass (Pennisetum setaceum) is an escaped ornamental perennial bunchgrass from Africa that has invaded parts of Hawaii and the Sonoran Desert. It is adapted to fire and increases hazardous fuels causing wildfires in areas that may not have historically occurred. It was detected in the late 1990’s within the Mojave Desert at Joshua Tree NP and along the Colorado River corridor on the shores of Lake Mohave. The extent of these populations was limited and a rapid response was necessary to keep it from spreading out of control. If no action is taken then fountain grass would spread by …

Athel (Tamarix Aphylla) And Athel Hybrid (Tamarix Aphyllax Tamarix Ramosissima)Establishment And Control At Lake Mead National Recreation Area, Carrie Norman, Curt Deuser, Joshua Hoines

Lake Mead Science Symposium

Athel is a large evergreen ornamental tree that has been planted throughout the Southwest since the 1950’s. Athel was considered benign because it was thought to produce non-viable seed unlike its invasive relative, tamarisk. However, athel began establishing in the wild from seed on Lake Mead in 1983. Lake Mead NRA has been actively controlling athel since November 2004 along the high water mark of Lake Mead shoreline (439 miles) to prevent it from spreading throughout the Colorado River Drainage. The NPS contracts Nevada Conservation Corp crews and the Lake Mead Exotic Plant Management Team to implement the control efforts …

Diversity Of Estrogen Degrading Microorganisms In Las Vegas Wash And Lake Mead, Nevada, Usa, Susanna Blunt, Jim Bruckner, Jenny C. Fisher, Duane P. Moser

Lake Mead Science Symposium

Endocrine disrupting chemicals (EDCs) are a subject of intense research as more studies reveal their persistence in the environment and detrimental effects on wildlife. Steroid hormones, including the natural and synthetic estrogens estrone (E1), 17-beta-estradiol (E2) and 17- alpha-ethinyl estradiol (EE2), are among the most bioactive and have been detected at low concentrations in waterways downstream from wastewater treatment plants. Las Vegas Wash, a stream flowing into Lake Mead and fed primarily by treated wastewater, provides a unique experimental system in which to study the role microorganisms play in the fate and dispersal of these compounds in surface waters.

Assessment Of Endocrine And Gonadal Condition Of Male Largemouth Bass From Lake Mead, Nevada, Reynaldo Patino, Steven L. Goodbred, Erik Orsak, Jill A. Jenkins, Michael R. Rosen

Lake Mead Science Symposium

Las Vegas Bay (LVB) of Lake Mead receives combined flows of tertiary treated wastewater effluent, urban runoff, and groundwater from the Las Vegas metropolitan area. This study examined the potential for endocrine disrupting effects of these anthropogenic inputs on male largemouth bass (Micropterus salmoides). Adult male bass were collected at two sites within Lake Mead: Overton Arm (OA, reference site), and Las Vegas Bay (LVB). Post-spawn fish were collected in July 2007 (n = 6-10 per site) and pre-spawn fish in March 2008 (n = 13 per site). Post-spawn fish were characterized by regressed testes whereas pre-spawn bass had full-grown …

Protection Of Macrophages J774a.1 By Purine Nucleoside Analogues From Bacillus Anthracis Mediated Necrosis, Zadkiel R. Alvarez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Eight years after the lamentable anthrax attacks, major scientific effort continues to be done, in order to stop imminent acts of bioterrorism. Innovative ways of therapy against the anthrax disease are being investigated. B. anthracis, the etiological agent of the infection, has a dormant stage in its life cycle known as the endospore. When conditions become favorable spores germinate, transforming into vegetative bacteria. In inhalational anthrax, the most fatal manifestation of the disease, spores enter the organism through the respiratory track, and are phagocytosized by alveolar macrophages of the lungs. Spores are able to sense nutrient availability, activating their germination …

2009- 2010 Unlv Mcnair Journal, Kathleen Bell, Danetta Bradley, Vacheral M. Carter, Nydia Diaz, Kathryn E. English, Sarah Harrison, Michelle Israel, Christina Macke, Erica Orozco, Pilar Palos, Sandra Ramos, Soraya A. Silverman, Susan Taylor, Sajar Camara, William Mccurdy, Yvonne C. Morris, Maxym V. Myroshnychenko, Ricardo Rios, Monique Sulls, Bremen Vance, Barbara Wallen

McNair Journal

Journal articles based on research conducted by undergraduate students in the McNair Scholars Program

Table of Contents

Biography of Dr. Ronald E. McNair

Statements:

Dr. Neal J. Smatresk, UNLV President

Dr. Juanita P. Fain, Vice President of Student Affairs

Dr. William W. Sullivan, Associate Vice President for Retention and Outreach

Mr. Keith Rogers, Deputy Executive Director of the Center for Academic Enrichment and Outreach

McNair Scholars Institute Staff

Mojave Applied Ecology Notes Winter 2009, Scott R. Abella, Lindsay P. Chiquoine, Alice C. Newton

Mojave Applied Ecology Notes

Chronology of forest structure and use in the Spring Mountains, Soil-Tech’s restoration work balancing construction with nature, species performance and treatment effectiveness for revegetation projects, and strategic research areas for Mojave conservation and management

In Step With Hiv Vaccines? A Content Analysis Of Local Recruitment Campaigns For An International Hiv Vaccine Study, Paula M. Frew, Wendy Macias, Kayshin Chan, Ashley Harding

Environmental & Occupational Health Faculty Publications

During the past two decades of the HIV/AIDS pandemic, several recruitment campaigns were designed to generate community involvement in preventive HIV vaccine clinical trials. These efforts utilized a blend of advertising and marketing strategies mixed with public relations and community education approaches to attract potential study participants to clinical trials (integrated marketing communications). Although more than 30,000 persons worldwide have participated in preventive HIV vaccine studies, no systematic analysis of recruitment campaigns exists. This content analysis study was conducted to examine several United States and Canadian recruitment campaigns for one of the largest-scale HIV vaccine trials to date (the “Step …

Early Post-Fire Plant Establishment On A Mojave Desert Burn, Scott R. Abella, E. Cayenne Engel, Christina L. Lund, Jessica E. Spencer

Public Policy and Leadership Faculty Publications

Fire has become more extensive in recent decades in southwestern United States arid lands. Burned areas pose management challenges and opportunities, and increasing our understanding of post-fire plant colonization may assist management decision-making. We examined plant communities, soils, and soil seed banks two years after the 2005 Loop Fire, located in a creosote-blackbrush community in Red Rock Canyon National Conservation Area in southern Nevada’s Mojave Desert. Based on a spring sampling of 20, 0.01-ha plots, live + dead cover of the exotic annual Bromus rubens averaged nine times lower on the burn than on a paired unburned area. Perennial species …

Progress In Strategic Research Areas, Scott R. Abella

Public Policy and Leadership Faculty Publications

Three years ago through conversations with resource managers, assessing the status of knowledge of the scientific literature, and our own interests, we set forth several strategic research areas that we believed would be timely for advancing Mojave Desert conservation and management.

Minimotif Miner 2nd Release: A Database And Web System For Motif Search, Sanguthevar Rajasekaran, Sudha Balla, Patrick R. Gradie, Michael R. Gryk, Krishna Kadaveru, Vamsi Kundeti, Mark W. Maciejewski, Tian Mi, Nicholas Rubino, Jay Vyas, Martin R. Schiller

Life Sciences Faculty Research

Minimotif Miner (MnM) consists of a minimotif database and a web-based application that enables prediction of motif-based functions in user-supplied protein queries. We have revised MnM by expanding the database more than 10-fold to approximately 5000 motifs and standardized the motif function definitions. The web-application user interface has been redeveloped with new features including improved navigation, screencast-driven help, support for alias names and expanded SNP analysis. A sample analysis of prion shows how MnM 2 can be used.

An Algorithm For Identifying Novel Targets Of Transcription Factor Families: Application To Hypoxia-Inducible Factor 1 Targets, Yue Jiang, Bojan Cukic, Donald A. Adjeroh, Heath D. Skinner, Jie Lin, Qingxi J. Shen, Bing-Hua Jiang

Electrical & Computer Engineering Faculty Research

Efficient and effective analysis of the growing genomic databases requires the development of adequate computational tools. We introduce a fast method based on the suffix tree data structure for predicting novel targets of hypoxia-inducible factor 1 (HIF-1) from huge genome databases. The suffix tree data structure has two powerful applications here: one is to extract unknown patterns from multiple strings/sequences in linear time; the other is to search multiple strings/sequences using multiple patterns in linear time. Using 15 known HIF-1 target gene sequences as a training set, we extracted 105 common patterns that all occur in the 15 training genes …

Experimental And Natural Variation In Hovering Flight Capacity In Bees, Hymenoptera: Apidae, Jason Thomas Vance

UNLV Theses, Dissertations, Professional Papers, and Capstones

In honey bees, the capacity for flight underlies many behaviors which impact fitness and longevity, such as the ability to forage or evade predators. However, flight capacity is not fixed across bees' lifespan, which is punctuated by a suite of physiological changes that accompany age and the transition from in-hive to foraging behaviors; thus, flight capacity may vary during periods of development, senescence, or in response to morphological damage such as wing wear. This dissertation describes the biomechanics and aerodynamics which contribute to the scope of honey bee flight performance, and investigates how age, behavioral development, and wing-wear affects flight …

Characterization Of Aerobic Respiration In Great Basin Hot Springs, Caitlin N. Murphy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Despite a wide diversity of possible electron donors available to fuel chemolithotrophy, it has been proposed that hydrogen is the single most important electron donor in geothermal ecosystems. To directly test this hypothesis, a simple system was devised to determine whether microorganisms in hot spring water and sediment are capable of using hydrogen and other electron donors for aerobic respiration using microrespirometry. The protocol for these experiments was developed using pure cultures of Thermocrinis ruber to determine the effect of growth conditions on the rate of oxygen consumption following the addition of electron donors. For field experiments, samples were collected …

Ground Reaction Forces For Children Running In Different Shoes, Dana Forrest

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to determine whether certain ground reaction force parameters such as impact force (F1), second maximum force (F2), loading rate, stance time and average vertical ground reaction force (Fzavg) differ when 11-13 year old children run in a neutral shoe (Nike Air Pegasus+ 25) that is either a child or adult style.

Shoes were impact tested in an impact test instrument to determine any performance differences between the two shoes. Next, 10 healthy female subjects aged 12.03 ± 1.14 years with a height of 154.6 ± 4.90 cm and a mass of 46.18 ± 14.33 …

When Did The Ancestors Of Polynesia Begin To Migrate To Polynesia? The Mtdna Evidence, David Lesniewski

UNLV Theses, Dissertations, Professional Papers, and Capstones

The timing and nature of the migration of the ancestors of the Polynesian people is debated by two competing theories. The "Express Train" and "Slow Boat" theories assert that the migration of the Proto-Polynesian people began around 6,000 years before present (BP) or around 10,000 years BP respectively. Through the use of haplogroups and specific genetic mutations a direct relationship between the Proto-Polynesians and modern Polynesians was attempted to test which of these theories was correct. The ancient skeletal remains from the island of Borneo currently housed at UNLV were used in this study as their dates fall within both …

Neurocognitive Deficits And Functional Outcome In Bipolar Disorder, Danielle T. Bello

UNLV Theses, Dissertations, Professional Papers, and Capstones

Bipolar disorder affects approximately 1% of the population. It is a severe and debilitating illness, causing serious impairment of interpersonal, occupational and social functioning. The disorder is characterized by marked mood swings as well significant neurocognitive deficits. Based on work with other psychiatric and neurological disorders, neurocognitive deficits in bipolar disorder are expected to be strong predictors of functional capacity. However, few studies have evaluated the consequences of neurocognitive deficits in this disorder. Most available studies have focused on the clinical correlates of functional outcome, such as number of hospitalizations, age of disorder onset, and severity of symptoms. While useful, …

Integrated Responses Of Crustaceans Inhabiting Estuaries To The Challenges Of Feeding And Digestion In Low Salinity, Daniel Luke Curtis

UNLV Theses, Dissertations, Professional Papers, and Capstones

Estuaries are highly productive and serve as vital habitats for numerous decapod crustacean species. However, the environmental conditions within estuaries are often highly dynamic and subject to large changes in salinity and temperature that occur on seasonal and tidal scales. Not all of the species occupying these habitats are adept in coping with changes in these environmental conditions. This dissertation describes the influence of low salinity conditions on the 1) habitat preference, 2) feeding behaviour and 3) digestive physiology of crustaceans inhabiting estuaries. I have primarily focussed on a weak osmoregulator, the Dungeness crab, Cancer magister , but have also …

Effects Of Plant Uptake And Micro-Topography On Chloride Transport In Arid Soils, Wenming Nie

UNLV Theses, Dissertations, Professional Papers, and Capstones

Chloride concentration profiles to depths of 1 m were evaluated on a young alluvial fan in Eldorado Valley, NV. It was found that chloride beneath plant canopies were 11 to 222 times higher than adjacent (1 - 2 m away) bare soil locations. Two-dimensional numerical simulations using HYDRUS 2D/3D model were used to further explore the impact of plants on chloride transport. The simulation results indicated that lateral flow driven by root uptake concentrated chloride toward root zones, leading to the accumulation of chloride under plant canopies. Results also suggest that locally micro-topography can have a substantial impact on chloride …

Molecular Systematics And Phylogeography Of The Genus Richardsonius, Derek Dee Houston

UNLV Theses, Dissertations, Professional Papers, and Capstones

The complex geological and climatic events that significantly altered the landscape throughout the Cenozoic Era impacted the diversification of many North American taxa, including freshwater fishes. Here, I employ an array of phylogenetic analyses using a multiple gene tree approach to address several questions regarding the phylogenetic relationships of the North American cyprinid genus Richardsonius and two other closely related genera, Clinostomus and Iotichthys. I also use divergence time estimates generated using fossil calibrations to qualitatively assess the phylogeographic implications of evolution within and among these three genera. Mitochondrial and nuclear DNA sequences show a sister relationship between Iotichthys and …