Life Sciences Commons^™

Documentation And Control Of Acetolactate Synthase-Resistant Barnyardgrass (Echinochloa Crus-Galli) In Arkansas Rice, Michael Joshua Wilson

Graduate Theses and Dissertations

Barnyardgrass, the most problematic grass weed of Arkansas rice, was found resistant to propanil in 1990, and since then, it has evolved resistance to quinclorac and clomazone. Barnyardgrass is now believed to have evolved resistance to acetolactate synthase (ALS)-inhibiting herbicides. The goal of this research was to confirm and determine the level of resistance of the putative resistant biotype to the ALS-inhibiting herbicides imazethapyr, bispyribac, and penoxsulam and to develop herbicide programs for controlling ALS-, propanil-, quinclorac-, and clomazone-resistant barnyardgrass. The lethal dose needed to kill 50% of the putative ALS-resistant plants was higher than that of the susceptible biotype …

Farmers' Perceptions Of Cotton Pests And Their Management In Western Kenya, Charles A.O. Midega, Isaac M. Nyang'au, Jimmy Pittchar, Michael A. Birkett, John A. Pickett, Miguel Borges, Zeyaur R. Khan

All Peer-Reviewed Publications

Cotton (Gossypium hirsutum L.) production in western Kenya is severely affected by insect pests, resulting in poor yields in spite of the growing demand for the commodity. One of the key constraints to establishing effective pest management approaches for smallholder farmers is the lack of adequate information about farmers' knowledge, perceptions and practices in pest management. This study was therefore conducted to (1) evaluate farmers' knowledge and perceptions of cotton pests; (2) examine farmers' current practices in managing cotton pests; (3) identify pest management challenges and intervention opportunities in order to develop efficient integrated pest management (IPM) approaches. A total …

Shock Attenuation In Landing, Bryon Christopher Applequist

UNLV Theses, Dissertations, Professional Papers, and Capstones

Shock attenuation (SA) has been well studied in activities such as walking and running (Chu, et al. 2004; Derrick, et al. 2004; Mercer, et al. 2003); however, there is a lack of research regarding SA during landing. Furthermore, there is lack of information regarding which structures attenuate shock. The purpose of this study was to examine SA among the leg-hip, hip-head, and leg-head segments during landing. Each subject (n=10, Age 26.3 ± 2.71 years, Height 1.68 ± 0.08 m, Mass 70.49 ± 16.03 kg) was instrumented with accelerometers at the leg, hip and forehead. Subjects then performed landings from three …

Evaluation Of The Tagelus® Ta 100d Sand Filter For Removing Quagga Mussel Veligers (Dreissena Rostriformis Bugensis) From Lake Water And The Effectiveness Of The Safeguard Ultraviolet Radiation System As A Biocide Against Veligers, Patricia Kathleen Delrose

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Lake Mead National Recreational Area was created by the construction of the Hoover Dam during the years 1931-1936. In January 2007, the quagga mussel (Dreissena rostriformis bugensis), was found in Lake Mead. This became the first known Dreissenid species in the southwest and the only time a large water system was first infested by the quagga mussel and not the zebra mussel (Dreissena polymorpha). This invasive species has quickly spread to Lake Mohave and further down the lower Colorado River drainage. The microscopic size (70 µm or larger) of the veliger life stage makes it impossible to see with …

Nitrite Oxidation In Geothermal Springs: Evidence Of An Upper Temperature Limit For Thermophilic Nitrite-Oxidizing Bacteria Of 60 - 65 °C, Tara Edwards

UNLV Theses, Dissertations, Professional Papers, and Capstones

Despite growing evidence of the importance of nitrification in terrestrial geothermal environments, little is known about nitrite oxidation in these environments. In order to further our knowledge, this study combined cultivation-dependent and -independent approaches with measurements of nitrogen speciation along the outflow channels of two Great Basin geothermal springs. Enrichment cultures were inoculated with sediment slurries from sites ranging in temperature from 42 - 87 °C at the sources and along the outflows of >15 hot springs. While attempts to enrich nitrite-oxidizing bacteria (NOB) from sites greater than or equal to 61 °C were unsuccessful, NOB were enriched from five …

Characterization Of Beryllium As A Novel Agent To Study Cell Cycle Arrest And Cellular Senescence, Priyatham Gorjala

UNLV Theses, Dissertations, Professional Papers, and Capstones

Cancer cells evade senescence, apoptosis, and other constraints on proliferation, often via mutation of the p53 tumor suppressor gene (TP53). Normal human lung fibroblasts have been shown to enter premature senescence upon exposure to beryllium. In these cells, BeSO₄ stabilizes p53 protein, increases p21 gene expression, induces senescence-associated β-galactosidase activity and causes cell proliferation arrest. In the present study, we have investigated whether BeSO₄ is able to induce similar effects in cancer cells that have wildtype p53. We have demonstrated that beryllium salt at low concentration can induce molecular changes in the p53 signaling pathway leading to cell …

Dreissena Rostiformis Bugensis: Desiccation Of Adult Quagga Mussels Found In Lake Mead As A Preventive Measure Against Overland Dispersal In The Western United States, Matthew Kappel

UNLV Theses, Dissertations, Professional Papers, and Capstones

The expansion of civilization across all borders of the world has proven to affect major components of ecosystems. Since the introduction and establishment of the aquatic invasive species (AIS),Dreissena rostiformis bugensis, commonly known as the quagga mussel, into the United States there has been an extensive amount of time and money spent on controlling and preventing their expansion across the United States. The quagga mussel is of major concern because of its ability to disrupt the ecological communities in previously non-infested bodies of water, which may cause a loss in biodiversity and effect environmental health. The quagga mussel has spread …

The Impact Of Creosote Bush (Larrea Tridentata) And Biological Soil Crust On Ca Distribution In Arid Soils Of The Mojave Desert, Brittany Myers

UNLV Theses, Dissertations, Professional Papers, and Capstones

Ca is an important nutrient that plays a role in membrane stability and cell repair in plant life. This study examines the impact of creosote bush (Larrea tridentata) and biological soil crust on calcium cycling and distribution in desert soils in order to explore the use of Ca as a biosignature. Samples of creosote bush, biological soil crust and eolian dust were taken at two field sites in the Mojave Desert. The first site is located in Eldorado Valley, NV, a soil formed on a young (800-1200 years) alluvial fan deposit; the second site is located on a late Holocene-aged …

Frictional Forces Of A Fixed, Esthetic Orthodontic Appliance System, Brady Michael Nance

UNLV Theses, Dissertations, Professional Papers, and Capstones

Purpose: The demands of an all esthetic fixed orthodontic appliance system are ever increasing in today's world. Frictional values of an esthetic, fixed orthodontic appliance system are needed to evaluate their clinical effectiveness for orthodontic treatment. The aim of this study is to evaluate the frictional values of various esthetic orthodontic archwires ligated to an esthetic orthodontic bracket.

Methods: Three types of stainless steel and nickel titanium alloy (niti) esthetic orthodontic archwires (epoxy, poly, plastic) in four sizes (.016, .018, .017 x .025, .019 x .025 inches) were ligated to both a stainless steel bracket system and a ceramic (esthetic) …

Rickettsia Felis In Cat Fleas, Ctenocephalides Felis Parasitizing Opossums, San Bernardino County, California, Kyle F. Abramowicz, J. W. Wekesa, C. N. Nwadike, Maria L. Zambrano, Sandor E. Karpathy, D. Cecil, J. Burns, R. Hu, Marina E. Eremeeva

Environmental Health Sciences: Faculty Publications

Los Angeles and Orange Counties are known endemic areas for murine typhus in California; however, no recent reports of flea-borne rickettsioses are known from adjacent San Bernardino County. Sixty-five opossums (Didelphis virginiana) were trapped in the suburban residential and industrial zones of the southwestern part of San Bernardino County in 2007. Sixty out of 65 opossums were infested with fleas, primarily cat fleas, Ctenocephalides felis (Bouché, 1835). The flea minimum infection rate with Rickettsia felis was 13.3% in pooled samples and the prevalence was 23.7% in single fleas, with two gltA genotypes detected. In spite of historic records of murine …

Engineered, Harnessed, And Hijacked: Synthetic Uses For Cytoskeletal Systems, Brian S. Goodman, Nathan D. Derr, Samara L. Reck-Peterson

Biological Sciences: Faculty Publications

Synthetic biology re-imagines existing biological systems by designing and constructing new biological parts, devices, and systems. In the arena of cytoskeleton-based transport, synthetic approaches are currently used in two broad ways. First, molecular motors are harnessed for non-physiological functions in cells. Second, transport systems are engineered in vitro to determine the biophysical rules that govern motility. These rules are then applied to synthetic nanotechnological systems. We review recent advances in both of these areas and conclude by discussing future directions in engineering the cytoskeleton and its motors for transport.

Semiochemicals From Herbivory Induced Cotton Plants Enhance The Foraging Behavior Of The Cotton Boll Weevil, Anthonomus Grandis, D. M. Magalhães, M. Borges, R. A. Laumann, E. R. Sujii, P. Mayon, J. C. Caulfield, C. A.O. Midega, Z. R. Khan, J. A. Pickett, M. A. Birkett, M. C. Blassioli-Moraes

All Peer-Reviewed Publications

The boll weevil, Anthonomus grandis, has been monitored through deployment of traps baited with aggregation pheromone components. However, field studies have shown that the number of insects caught in these traps is significantly reduced during cotton squaring, suggesting that volatiles produced by plants at this phenological stage may be involved in attraction. Here, we evaluated the chemical profile of volatile organic compounds (VOCs) emitted by undamaged or damaged cotton plants at different phenological stages, under different infestation conditions, and determined the attractiveness of these VOCs to adults of A. grandis. In addition, we investigated whether or not VOCs released by …

Role Of Polymeric Excipients On Controlled Release Profile Of Glipizide From Plga And Eudragit Rs 100 Nanoparticles, Pratap Naha, Hugh Byrne, Amulya Panda

Articles

Polylactic-co-glycolic acid (PLGA) 50:50 and Eudragit RS 100 nanoparticles entrapping glipizide along with excipients were prepared using single emulsion solvent evaporation method. The objective was to develop single oral dose glipizide nano particles for reducing blood sugar level in diabetes induced experimental animals. Incorporation of Polyethylene glycol (PEG) (0.5%), Hydroxypropyl methylcellulose (HPMC) (0.5%) and Tween 20 (0.5%) in the organic phase during particle formulation improved release profile of glipizide from the polymer particles. Entrapment efficiency of glipizide in all the polymeric formulations was around ~70 %. Around 80 % of glipizide was released from both PLGA and Eudragit …

Effects Of Salinity On The Toxicity Of Ionic Silver And Ag-Pvp Nanoparticles To Tisbe Battagliai And Ceramium Tenuicorne, Ailbhe Macken, Hugh Byrne, Kevin Thomas

Articles

The toxic effects of polyvinylpyrrolidone (PVP) coated silver nanoparticles (Ag-NP_PVP) and ionic Ag, to Tisbe battagliai (Tb) and Ceramium tenuicorne (Ct) were investigated and the usefulness of standardised marine guidelines for ENP risk assessment were assessed. The toxicity of Ag-NP_PVP [CtEC₅₀ = 26.6 µg/L, TbEC₅₀ = 7.9 µg/L] and Ag⁺ [CtEC₅₀ = 2312.2µg/L, Tb EC₅₀ = 90.9 µg/L] to both test species differed, with the silver ENPs being more toxic. In contrast to Ag⁺ the toxicity of Ag-NP_PVP increased significantly with increasing salinity, however, after thorough characterisation it was not …

Reactive Oxygen Species Mediated Dna Damage In Human Lung Alveolar Epithelial (A549) Cells From Exposure To Non-Cytotoxic Mfi-Type Zeolite Nanoparticles, Kunal Bhattacharya, Pratap Naha, Izabela Naydenova, Svetlana Mintova, Hugh Byrne

Articles

Increasing utilization of engineered nanoparticles in the field of electronics and biomedical applications demands an assessment of risk associated with deliberate or accidental exposure. Metal based nanoparticles are potentially most important of all the nanoparticles in terms of health risks. Microporousalumino-silicates and pure silicates named as zeolites and zeo-type materials with variety of structures, chemical compositions, particle sizes and morphologies have a significant number of industrial uses such as in catalysis, sorption and ion-exchange processes. In particular, the nanosized particles due to their unique properties are used in hybrid organic-inorganic materials for photography, photonics, electronics, labeling, imaging, and sensing. The …

Immunoproteomics: The Key To Discovery Of New Vaccine Antigens Against Bacterial Respiratory Infections, Ruth Dennehy, Siobhan Mcclean

Articles

The increase in antibiotic resistance and the shortage of new antimicrobials to prevent difficult bacterial infections underlines the importance of prophylactic therapies to prevent infection by bacterial pathogens. Vaccination has reduced the incidence of many serious diseases, including respiratory bacterial infections. However, there are many pathogens for which no vaccine is available and some vaccines are not effective among all age groups or among immunocompromised individuals. Immunoproteomics is a powerful technique which has been used to identify potential vaccine candidates to protect against pathogenic bacteria. The combination of proteomics with the detection of immunoreactive antigens using serum highlights immunogenic proteins …

Laboratory And Field Performance Of The Biosand Point Of Use Water Filtration System In The Artibonite Valley, Haiti, Andrew John Sisson

Masters Theses

The research presented here is summary two years of studying the Biosand filter (BSF) both in Haiti during March 2011 and in the laboratory. In Chapter 2, we examined the long term use and sustainability 55 BSF systems near Deschapelles, Haiti and 47% were found to be no longer in use. Interviews with BSF owners revealed problems related to intermittent filter use. A review of 17 BSF field studies also was included to compare and substantiate observations made in Haiti. Together, previous field studies and our observations point toward the importance of providing culturally appropriate technologies and education materials explaining …

Anti-Germinants As A New Strategy To Prevent Clostridium Difficile Infections, Amber Janece Howerton

UNLV Theses, Dissertations, Professional Papers, and Capstones

Clostridium difficileinfections (CDI) have emerged as a leading cause of hospital-associated complications. CDI is the major cause of antibiotic-related cases of diarrhea and nearly all cases of pseudomembranous colitis. The infective form of C. difficileis the spore, a dormant and hardy structure that forms under stress. Germination of C. difficile spores into toxin producing bacteria in the GI tract of susceptible patients is the first step in CDI establishment. Patient susceptibility occurs with a disruption of the natural gut microbiota by broad-spectrum antibiotics. Antibiotic treatments usually resolve CDI but refractory cases are on the rise. Of great concern is the …

Natural And Lignocellulose-Enriched Microbial Communities In Great Boiling Spring, Nv, Jessica Cole

UNLV Theses, Dissertations, Professional Papers, and Capstones

The natural microbial communities present in Great Boiling Spring were investigated and contrasted against those present after in situ enrichment with lignocellulose. High-throughput cultivation-independent DNA sequencing of the V8 region of the small subunit (SSU) rRNA gene generated a total of 274,119 quality-filtered pyrosequencing fragments. Twelve natural spring samples were analyzed, including four high-temperature water samples and eight sediment samples ranging from 87 - 62 °C. Eight lignocellulosic enrichments incubated in the spring sediment and water at two high-temperature sites were analyzed. The natural water communities were found to be extremely uneven but relatively constant throughout time. The natural sediment …

A Genetic, Transgenic, And Transcriptomic Analysis Of Larval Salivary Gland Physiology In Drosophila Melanogaster, Elana A. Paladino

UNLV Theses, Dissertations, Professional Papers, and Capstones

Cholesterol is the precursor to a unique class of lipophilic signaling molecules called steroid hormones that initiate the development of sexual characteristics, reactions to stress, and maintenance of metabolism, among many other functions. Although much progress has been made in understanding the function of these signaling hormones, we do not fully understand how a single steroid can cause many distinct, tissue-specific responses. Drosophila melanogaster is an effective model for understanding steroid hormone action because of its simplicity. The steroid molting hormone 20-hydroxyecdysone (hereafter, 20E) is the primary active steroid in Drosophila and mediates not only larval molts and the emergence …

Species Richness And Nest Dispersion Of Some Tropical Meliponine Bees (Apidae: Meliponinae) In Six Habitat Types In The Kakamega Forest, Western Kenya, Kiatoko Nkoba, Suresh Kumar Raina, Elluid Muli, Klaus Mithofer, Jones Mueke

All Peer-Reviewed Publications

A study to determine the species richness and spatial distribution of five meliponine bee species in three different habitats in the Kakamega forest was undertaken for the first time. Two forest (indigenous and mixed indigenous) and two grassland (with Eucalyptus spp. trees and indigenous trees) types, along with homesteads (in the vicinity of mixed indigenous forest and indigenous forest, respectively), were surveyed. Line transect methods were used in the nest survey in each habitat. The highest number of species was recorded in the indigenous forest, while no nest was discovered in the grassland with Eucalyptus spp. trees. The mean number …

Disentangling Dispersal, Vicariance And Adaptive Radiation Patterns: A Case Study Using Armyworms In The Pest Genus Spodoptera (Lepidoptera: Noctuidae), Gael J. Kergoat, Dorothy P. Prowell, Bruno P. Le Ru, Andrew Mitchell, Pascaline Dumas, Anne Laure Clamens, Fabien L. Condamine, Jean François Silvain

All Peer-Reviewed Publications

Thanks to the recent development of integrative approaches that combine dated phylogenies with models of biogeographic evolution, it is becoming more feasible to assess the roles of dispersal and vicariance in creating complex patterns of geographical distribution. However, the historical biogeography of taxa with good dispersal abilities, like birds or flying insects, still remains largely unknown because of the lack of complete phylogenies accompanied by robust estimates of divergence times. In this study, we investigate the evolution and historical biogeography of the globally distributed pest genus Spodoptera (Lepidoptera: Noctuidae) using complete taxon sampling and an extensive set of analyses. Through …

Bacteriophage Ecology In A Commercial Cucumber Fermentation, Jean Lu, Ilenys M. Perez-Diaz, Janet S. Hayes, Fred Bredit Jr.

Faculty Articles

To reduce high-salt waste from cucumber fermentations, low-salt fermentations are under development. These fermentations may require the use of starter cultures to ensure normal fermentations. Because potential phage infection can cause starter culture failure, it is important to understand phage ecology in the fermentations. This study investigated the phage ecology in a commercial cucumber fermentation. Brine samples taken from a fermentation tank over a 90-day period were plated onto deMan-Rogosa-Sharpe agar plates. A total of 576 lactic acid bacterial isolates were randomly selected to serve as potential hosts for phage isolation. Filtered brine served as a phage source. Fifty-seven independent …

A Review Of Cover Crops For Eastern Nebraska, Tyler Williams

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

The focus of this project is two fold, first to provide a short literature review of cover crops (CC) and then discuss the results from a field experiment that was designed to evaluate the nitrogen contribution from cover crop mixes to the subsequent corn crop. The literature review will focus on the aspects of CC that are related to the field of study. Cover crops, as defined by the United States Department of Agriculture (USDA) are crops that are agronomically sound and grown for the purpose of erosion control or other objectives related to conservation or soil improvement. Cover crops …

Nitrous Oxide Emissions From Smooth Bromegrass Pasture Under Nitrogen Fertilizer And Ruminant Urine Application In Eastern Nebraska, Laura K. Snell

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Nitrous oxide (N₂O) is a greenhouse gas primarily produced in soils by denitrifying and nitrifying organisms. Agricultural soils account for 70% of emissions in the United States, but little data is available for contributions from managed pasture ecosystems. This study focused on the production of N₂O in smooth bromegrass (Bromus inermis Leyss.) pastures established on silt loam soils in eastern Nebraska. Thirty smooth bromegrass plots (1.5m x 1.5m) were treated with five different fertilizer treatments (0, 45, 90, 135, and 180 kg N/ha) and two urine treatments (urine and no urine). Herbage sampling was taken …

Environmental Triggers Of Winter Annual Weed Emergence And Management To Reduce Soybean Cyst Nematode Reproduction On Winter Annual Weed Hosts, Rodrigo Werle

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Winter annual weeds are becoming more common in many row crop fields in the midwestern USA. The impact of winter annual weeds in cropping systems is often overlooked because these weeds complete their lifecycle near the time of crop sowing. However, delayed soil warming, competition for nutrients during initial establishment of the main crop, difficult planting operations, and yield loss are some of the problems caused by dense mats of winter annual weeds. Moreover, some of these weeds have been reported as alternative hosts for pests such as the soybean cyst nematode (Heterodera glycines, SCN), considered the most …

Ecology And Invasive Properties Of Musk Thistle (Carduus Nutans) In The Central Prairies Of Nebraska, Chengchou Han

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Musk thistle (Carduus nutans) is an herbaceous monocarpic herb introduced to the U. S. from Eurasia. The invasion of musk thistle can reduce forage area, soil stability, and reduce recreation and open areas for humans and wildlife.

Resistance of warm season and cool season perennial grass communities to musk thistle invasion is important for land managers to consider, especially where disturbance has made an area particularly susceptible. Our results show that disturbances, such as overgrazing can open up niches in canopies of warm season grass communities and facilitate invasion but not in cool season grass communities. The mechanism …

The Incentive And Benefits To Publish Research, Christopher N. Jacques

The Prairie Naturalist

In the northern Great Plains, December is a month marked by the end of the year and a period of much-needed rest and relaxation during the start of the winter season. Landscapes will soon be blanketed with snow and local floral and faunal species have adapted to the ensuing winter months ahead. Winter is a season that reminds you who you live in the Plains states, and as such, should expect bitter cold temperatures, strong winds, and blowing and drifting snow. However, December is a great time to enjoy the outdoors across the Great Plains, a time to reflect on …

Updated Manuscript Submission Guidelines For The Prairie Naturalist, Christopher N. Jacques, Troy W. Grovenburg, Jonathan A. Jenks

The Prairie Naturalist

These guidelines present updated policies and procedures for submitting scientific manuscripts for consideration for publication in The Prairie Naturalist (PNAT). These guidelines incorporate substantial changes that have occurred following a change in Editorial staff during January 2009, and update the online “Suggestions for Contributors” guidelines provided on the PNAT website (http://www.sdstate.edu/nrm/organizations/gpnss/tpn/index.cfm); these instructions supersede all previous guidelines.

Tables and appendices are included for common word expressions with superfluous wording (Table 1), examples of correct format and style guidelines for tables accompanying manuscripts (Table 2, Appendix A), guidance in properly preparing Research notes (Appendix B) and citing literature (Appendix …

Interior Least Tern Powerline Collision On The Lower Platte River, Lauren R. Dinan, Joel G. Jorgensen, Mary Bomberger Brown

The Prairie Naturalist

Collisions with electrical powerlines are a well-known documented cause of avian mortality (Avian Power Line Interaction Committee [APLIC] 1994, Savereno et al. 1996). Mortality caused by collisions with powerlines can be an important concern for many bird species, but is a serious conservation problem for threatened and endangered species because any mortality can have biological and legal ramifications (Janss 2000). Loss of individuals, particularly breeding adults, from an already small population may impede a species’ recovery by reducing reproduction and recruitment into the breeding population. The death of an individual from a threatened or endangered species as a result of …