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Full-Text Articles in Physical Sciences and Mathematics

Logistic Regression Analysis To Determine Factors Contributing To Summer Feedlot Deaths, J. Clausen, A. M. Parkhurst, T. L. Mader May 2011

Logistic Regression Analysis To Determine Factors Contributing To Summer Feedlot Deaths, J. Clausen, A. M. Parkhurst, T. L. Mader

Conference on Applied Statistics in Agriculture

Summer heat has already been identified as a major factor for cattle deaths in the feedlot. This study attempts to assess what other factors contribute to and/or influence cattle deaths. Identifying multiple factors that contribute to summer feedlot deaths could aid feedlot managers in implementation of mitigation strategies and minimize the loss of nearly finished cattle. Daily pen, cattle, and nutritional characteristics were recorded and included in this generalized linear mixed model analysis. Cattle data were obtained from cattle pens at a single location from July 1, 2010 to July 31, 2010. Hourly weather data were acquired from this feed …


Confidence Intervals For Variance Components Using Non-Normal Distributions, Brent D. Burch May 2011

Confidence Intervals For Variance Components Using Non-Normal Distributions, Brent D. Burch

Conference on Applied Statistics in Agriculture

Simulation studies are conducted to evaluate the performance of confidence intervals for variance components under non-normal distribution assumptions. Confidence intervals based on the pivotal quantity (PQ) method and the large-sample properties of the restricted maximum likelihood (REML) estimator are considered. Of particular interest is the actual coverage value of nominal 95% confidence intervals for a ratio of variance components. In the context of unbalanced one-way random effects models, simulation results and an empirical example involving arsenic concentrations in oyster tissue suggest that the REML-based confidence interval is preferred.


Ordinary Least Squares Regression Of Ordered Categorical Data: Inferential Implications For Practice, Beth Larrabee, H. Morgan Scott, Nora M. Bello May 2011

Ordinary Least Squares Regression Of Ordered Categorical Data: Inferential Implications For Practice, Beth Larrabee, H. Morgan Scott, Nora M. Bello

Conference on Applied Statistics in Agriculture

Ordered categorical responses (OCRs) are frequently encountered in many disciplines. Examples of interest in agriculture include quality assessments, such as for soil or food products, and evaluation of lesion severity, such as teat ends status in dairy cattle. OCRs are characterized by multiple categories recorded on a ranked scale that, while apprising relative order, is not informative of absolute magnitude of or proportionality between the categories. A number of statistically sound models for OCRs are available in the statistical literature, such as logistic regression and probit models, but these are commonly underutilized in practice. Instead, the ordinary least squares linear …


Issues In Testing Dna Methylation Using Next-Generation Sequencing, Douglas Baumann, R. W. Doerge May 2011

Issues In Testing Dna Methylation Using Next-Generation Sequencing, Douglas Baumann, R. W. Doerge

Conference on Applied Statistics in Agriculture

DNA methylation is an epigenetic modification known to affect gene expression, cellular differentiation, as well as phenotypes. Recent advancements in next-generation sequencing technologies have provided unparalleled insight into the location and function of DNA methylation in a variety of organisms. These data require vastly different statistical procedures than data from previous genomic-based technologies. We outline the biological and chemical processes involved in several approaches for gaining DNA methylation data. The implications of the differences between the approaches are discussed relative to the statistical methodology, and the use of genome annotation is explored for the purpose of improving the statistical power …


Editor's Preface And Table Of Contents, Weixin Yao May 2011

Editor's Preface And Table Of Contents, Weixin Yao

Conference on Applied Statistics in Agriculture

These proceedings contain papers presented in the twenty-third annual Kansas State University Conference on Applied Statistics in Agriculture, held in Manhattan, Kansas, May 01 - May 03, 2011.


A Model For Relating Environmental Variation To Water Permit Violations At Thermoelectric Facilities, Seth Sheldon Apr 2011

A Model For Relating Environmental Variation To Water Permit Violations At Thermoelectric Facilities, Seth Sheldon

Interdisciplinary Perspectives: a Graduate Student Research Showcase

A regression model is presented which relates cooling water withdrawal rates and discharge temperatures at two mid-size thermoelectric facilities to electricity demand and ambient air temperature using historical data. Both facilities employ open-loop cooling systems, which have substantial water demands. Open-loop facilities comprise roughly one third of U.S. generation capacity. High water demands put facilities and downstream aquatic habitats at risk during heat waves and droughts, and put facility managers in a position to decide between reducing their power generation and violating their permit limits. National Pollutant Discharge Elimination System (NPDES) permits place limits on cooling water withdrawals and effluent …


Risk Auto Theft: Predicting Spatial Distributions Of Crime Events, Tana J. Gurule, Tamara D. Madensen Apr 2011

Risk Auto Theft: Predicting Spatial Distributions Of Crime Events, Tana J. Gurule, Tamara D. Madensen

Graduate Research Symposium (2010 - 2017)

Police typically rely on retrospective hotspot maps to informe prevention strategies aimed at reducing future crime. The current study reviews environmental crime theories that help to identify casual factors associated with rish of auto theft. Map layers are created from data that operationalize these risk factors. These layers are combined using spatial analysis techniques to produce a "risk density" map. Analysis of crime data are used to determing wheter our "risk density" map better predicts subsequetnt theft events than a traditional retrospective hotspot map.


Keynote Address: Community Health In Las Vegas, Camila H. Alvarez Apr 2011

Keynote Address: Community Health In Las Vegas, Camila H. Alvarez

Festival of Communities: UG Symposium (Posters)

New Urbanists present both a theory for strong community development and an architectural planning program for moving towards sustainable urban environments. They argue neighborhoods should be compact, pedestrian-friendly, with mixed-usage of housing and activities, and available public spaces. These design elements foster and encourage social interaction among residents which creates and enforces neighborhood community. I tested New Urbanism Theory by performing ethnographic fieldwork to assess the quality of neighborhoods in Las Vegas. Then I compared neighborhood qualities to residents’ responses to their neighborhood, neighbors, and quality of life from the Las Vegas Metropolitan Area Social Survey. My results confirmed New …


Relationship Between Perceived And Actual Quality Of Data Checking, Hunter Speich, Sophia Karas, Dan Erosa, Kelly Grob, Kimberly A. Barchard Apr 2011

Relationship Between Perceived And Actual Quality Of Data Checking, Hunter Speich, Sophia Karas, Dan Erosa, Kelly Grob, Kimberly A. Barchard

Festival of Communities: UG Symposium (Posters)

Data quality is critical to reaching correct research conclusions. Researchers attempt to ensure that they have accurate data by checking the data after it has been entered. Previous research has demonstrated that some methods of data checking are better than others, but not all researchers use the best methods. Perhaps researchers continue to use less optimal data checking methods because they mistakenly believe that they are highly accurate. The purpose of this study was to examine the relationship between perceived data quality and actual data quality. A total of 29 participants completed this study. Participants checked that letters and numbers …


Analysis Of Morris Water Maze Data With Bayesian Statistical Methods, Maxym V. Myroshnychenko, Anton Westveld, Jefferson Kinney Apr 2011

Analysis Of Morris Water Maze Data With Bayesian Statistical Methods, Maxym V. Myroshnychenko, Anton Westveld, Jefferson Kinney

Festival of Communities: UG Symposium (Posters)

Neuroscientists commonly use a Morris Water Maze to assess learning in rodents. In his kind of a maze, the subjects learn to swim toward a platform hidden in opaque water as they orient themselves according to the cues on the walls. This protocol presents a challenge to statistical analysis, because an artificial cut-off must be set for those experimental subjects that do not reach the platform so as they do not drown from exhaustion. This fact leads to the data being right censored. In our experimental data, which compares learning in rodents that have chemically induced symptoms of schizophrenia to …


Global Warming: At What Point Does Atmospheric Greenhouse Gas Release Become Unethical?, Luke Good, Gladys Lopez Apr 2011

Global Warming: At What Point Does Atmospheric Greenhouse Gas Release Become Unethical?, Luke Good, Gladys Lopez

Festival of Communities: UG Symposium (Posters)

In recent decades, the concept of global warming has developed increasing concern among the scientific community and general public alike. What was initially dismissed as little more than unlikely has now become a severe warning for global climate crisis threatening not only our way of life but ultimate future existence on this planet? Global warming is defined as the steady mean increase in atmospheric temperature, the primary asserted cause thereof being increased emissions and inherent atmospheric concentrations of “greenhouse gases” – carbon dioxide in particular. These gases contribute to the greenhouse effect by trapping radiation (from the sun) in the …


Unlv Enrollment Forecasting, Sabrina Beckman, Stefan Cline, Monika Neda Apr 2011

Unlv Enrollment Forecasting, Sabrina Beckman, Stefan Cline, Monika Neda

Festival of Communities: UG Symposium (Posters)

Our project investigates the future enrollment of undergraduates at UNLV in the entire university, the College of Science, and the Department of Mathematical Sciences. The method used for the forecast, is the well-known least-squares method, for which a mathematical description will be presented. Studies for the numerical error are pursued too. The study will include graphs that describe the past and future behavior for different parameter settings. Mathematical results obtained show that the university will continue to grow given the current trends of enrollment.


Entangling The Lattice Clock With Rydberg Gates, Frank J. Greenhalgh Apr 2011

Entangling The Lattice Clock With Rydberg Gates, Frank J. Greenhalgh

Festival of Communities: UG Symposium (Posters)

Knowledge of the exact time is critical to many engineers and planetary experts; unfortunately atomic clocks can't have infinite accuracy by Heisenberg's uncertainty principle. To attain accuracy past the limit we have achieved today, we will design a critical improvement of the atomic clock via the Rydberg gates method. Rydberg gates synchronize the atomic states so that they are more sensitive which will greatly increase the accuracy. This project will introduce fast acting Rydberg gates to an existing atomic clock layout. The Rydberg gates will allow the clock to entangle atoms in less time, thus decreasing decoherence effects on the …


Thin-Film Fabrication For High Pressure Thermoelectric And Electrical Resistivity Studies, Jorge L. Reynaga, Rama Venkat, Ravhi S. Kumar Apr 2011

Thin-Film Fabrication For High Pressure Thermoelectric And Electrical Resistivity Studies, Jorge L. Reynaga, Rama Venkat, Ravhi S. Kumar

Festival of Communities: UG Symposium (Posters)

Thermoelectric materials are of interest for application such as thermoelectric cooler in microprocessors and power generators in cars. High pressure plays an important role in understanding the changes in the figure of merit of thermoelectric thin films. To study the thermoelectric thin films a direct approach is to fabricate the thin film on the surface of a diamond anvil, so that the pressure dependence of structure and transport properties can be investigated easily. If we could successfully fabricate the electrical probes by depositing thin films, then it reduces the use of electrical wires as probes inside the diamond cell, as …


Exploring The Potential Of Agave As A Biofuel Crop On Arid Land, Rhea Conlu, Diana Ha, Jeffery Shen Apr 2011

Exploring The Potential Of Agave As A Biofuel Crop On Arid Land, Rhea Conlu, Diana Ha, Jeffery Shen

Festival of Communities: UG Symposium (Posters)

Worldwide awareness of global warming and depleting fossil fuel sources has made research into alternative resources, such as plant fuels imperative. Since groundwater irrigation is unsustainable, especially in desert climates, plants that are drought resistant or can utilize otherwise unusable water are more viable sources of future biofuel production. Agave nevadensis, a species belonging to the family Agavaceae are succulent plants native to Las Vegas. This experiment aims to expose A. nevadensis to both wastewater and drought conditions and observe its response. The results can help define Agave as a water-resourceful biofuel both tolerant of drought and capable of utilizing …


Mathematical Analysis And Applications Of Logistic Differential Equation, Eva Arnold, Monika Neda Apr 2011

Mathematical Analysis And Applications Of Logistic Differential Equation, Eva Arnold, Monika Neda

Festival of Communities: UG Symposium (Posters)

Logistic differential equation has a way to measure the proportionality of various resources with respect to time. This equation has been used in many research areas, such as, biology, medicine, psychology, economics, etc. A mathematical description, analysis and solution of the logistic type differential equation is studied. Besides the mathematical part, the poster will contain biological examples, graphs of the direction fields for different parameter settings and logistic plots for specific species population. The logistic growth function will also be applied to learning curves in area of psychology, as a rate at which performance improves.


Sustainable Alternative To Non-Biological Nitrogen Fixation To Nitrate For Fertilizers, Patrick Freeze, Glenn Miller Apr 2011

Sustainable Alternative To Non-Biological Nitrogen Fixation To Nitrate For Fertilizers, Patrick Freeze, Glenn Miller

Festival of Communities: UG Symposium (Posters)

Currently, the industrial method of nitrogen fixation for use in fertilizers (Haber- Bosch process [N2 (g) + 3 H2 (g) <--> 2 NH3 (g)]) is our main source of non-biological conversion of atmospheric nitrogen to ammonia. The proposed research experiment utilizes the catalytic mechanism of titanium dioxide which, in the presence of heat or sunlight, undergoes fixation of atmospheric nitrogen. This method of nitrate production could serve as a sustainable source of nitrogen for fertilizers. Variables in the experiment included the manipulation of thermal pressure, heat, and base addition to counteract hydrochloric acid production, a selflimiting byproduct.


Structure Studies On Lanthanide Technetium Pyrochlores As Prospective Host Phases To Immobilize 99- Technetium And Fission Lanthanides From Effluents Of Reprocessed Used Nuclear Fuels, Thomas Hartmann, Ariana Alaniz Apr 2011

Structure Studies On Lanthanide Technetium Pyrochlores As Prospective Host Phases To Immobilize 99- Technetium And Fission Lanthanides From Effluents Of Reprocessed Used Nuclear Fuels, Thomas Hartmann, Ariana Alaniz

Festival of Communities: UG Symposium (Posters)

We performed a systematic investigation of the incorporation of 99Tc into pyrochlore oxide structures, Ln2Tc2O7, where Ln represents trivalent lanthanide Ln3+ cations, while 99Tc is atetravalent, Tc4+, metal cation. Pyrochlore compounds are high-melting temperature oxides and are recognized for their durability. Our goal in this preliminary study is to characterize and quantify the range of stability of the lanthanum technetium pyrochlore oxide phase. Hereby, powder X-ray diffraction (XRD) and Rietveld analysis were used to determine and characterize the crystalline phase content with high accuracy, and scanning electron microscopy (SEM) was used to characterize the microstructure and homogeneity of the synthesized …


Predicting Homo And Lumo Energy Gaps For Organic Semi-Conductor: A Theoretical Study, Padtaya Pukpayat Apr 2011

Predicting Homo And Lumo Energy Gaps For Organic Semi-Conductor: A Theoretical Study, Padtaya Pukpayat

Festival of Communities: UG Symposium (Posters)

This poster presents a theoretical approach for characterizing the electronic properties of novel electron-deficient organic semiconductors containing variety of electron donor substituents. In treating these compounds, the following questions will be addressed: What effects to the bandgap will each substituent have? Will any of the substituents lower the band gap to the desired range for solar cell applications(<2.0eV)? Can we use the current, inexpensive and tractable computational methods as a predictive tool for guiding future experimental design of organic based solar cells, rather than depending solely on experimental procedures?


Accumulation Of Polonium-210 In Different Species Of Fish In Lake Mead, Suraj Ghevarghese John, Shungmugam Nallaperumal, Vernon Hodge Apr 2011

Accumulation Of Polonium-210 In Different Species Of Fish In Lake Mead, Suraj Ghevarghese John, Shungmugam Nallaperumal, Vernon Hodge

Festival of Communities: UG Symposium (Posters)

Discovered by Pierre Curie and Marie Skłodowska-Curie in 1898, polonium is a chemical element with an atomic number of 84. This rare naturally occurring radioactive element is chemically similar to bismuth and tellurium, and forms in uranium ores. Polonium-210 is an naturally occurring radioactive element with a half-life of 138.376 days(1). This element is found in trace amounts in most organisms. Our research is focused on the accumulation of polonium-210 in fish that occupy in Lake Mead.

The sample species is chosen based on varying lake stratification (layers of the lake). This gives us a good idea of the difference …


Adaptation Of The Nevada Climate Change Data Portal Web Interface To Small-Screen Mobile Devices, Tsvetan Komarov Apr 2011

Adaptation Of The Nevada Climate Change Data Portal Web Interface To Small-Screen Mobile Devices, Tsvetan Komarov

Festival of Communities: UG Symposium (Posters)

Robust and convenient access to the Nevada Climate Change Data Portal is vital for the project’s success, because of the researchers’ need to gather and analyze large volumes of data with minimal effort. However, the current version of the data portal web interface is not optimized for small-screen mobile devices such as mobile phones, PDAs, iPads, NetBooks, and others. The proposed research will address this issue by exploring the current methods for creating a client-aware web interface adaptable to the variety of small-screen devices, designing and implementing the most appropriate solution, and finally, user testing of the implemented solution.


The Effects Of Climate Change On Basic Animal Cell Functions, Michelle Fulbright, Andrew Andres Apr 2011

The Effects Of Climate Change On Basic Animal Cell Functions, Michelle Fulbright, Andrew Andres

Festival of Communities: UG Symposium (Posters)

Increasing global temperatures during the 21st century may have detrimental effects on basic cell functions within ectothermal animals. This project aims to systematically examine the effects of climate change on secretory cargo localization through the analysis of Rab Proteins found in the model organism Drosophila melanogaster. Rab Proteins play an essential role in vesicular transport within the cell and can be genetically manipulated to monitor the biological consequences of global warming.


Groundwater: Solution To The Las Vegas Water Problem?, Rosa Perez, Christopher Ruiz Apr 2011

Groundwater: Solution To The Las Vegas Water Problem?, Rosa Perez, Christopher Ruiz

Festival of Communities: UG Symposium (Posters)

A contentious debate is taking place in different sectors of the community on how to manage the states groundwater system. It is a battle whose outcome, regardless of who wins, will have a tremendous impact on the future of Las Vegas. Economic benefits always seem to downplay environmental considerations in the policy-making process often with serious consequences. This paper takes a look at the SNWAʼs Groundwater Development Project and provides a discussion of the issues for and against it. Groundwater is inexpensive, relatively abundant and accessible. However, over-pumping of groundwater can have significant environmental consequences, as well. It is our …


Energy Densification Via Hydrothermal Carbonization, Keri Noack Apr 2011

Energy Densification Via Hydrothermal Carbonization, Keri Noack

Festival of Communities: UG Symposium (Posters)

A process called hydrothermal carbonization (HTC), also known as wet torrefaction involves treatment of raw biomass in hot, pressurized water. HTC of woody biomass has been shown to significantly increase the energy density of the feedstock, producing a biochar, similar to coal, having up to 40% higher calorific energy content. Feedstocks investigated include Tahoe chips, Pinion/Juniper chips, Rice hulls, and Corn Stover pellets pre-treated at 215 °C, 255 °C, and 295 °C. Chemical analyses were conducted on the gaseous, aqueous, and solid HTC products. Energy contents of the solid biochar products were measured by calorimetry, and mass balances were determined.


Oral Presentation: The Universe In A Box, Jason Jaacks Apr 2011

Oral Presentation: The Universe In A Box, Jason Jaacks

Festival of Communities: UG Symposium (Posters)

When and how galaxies formed throughout the history of the Universe is one of the most fundamental questions of astronomy and astrophysics. As technology improves, astronomers are able to push the frontier of galaxy observation to a period when the Universe was less than 1 billion years old. This is when the first galaxies are beginning to form. However, beyond the limits of observational technology lies data fundamental to our complete understanding of these processes. Using state-of-the-art cosmological hydrodynamic computer codes combined with access to the nation’s largest and fastest supercomputers, we are able to simulate the formation and evolution …


Oral Presentation: Next Generation Nuclear Fuels, Douglas Hanks Apr 2011

Oral Presentation: Next Generation Nuclear Fuels, Douglas Hanks

Festival of Communities: UG Symposium (Posters)

Zirconium carbide has been proposed as a coating layer for next generation (“TRISO”) nuclear fuel, and is intended as a diffusion barrier to contain fission products (e.g., Pd). To study the chemical interaction between Pd and ZrC, their interface was investigated using X-ray Photoelectron Spectroscopy (XPS). Pd was step-wise deposited onto ZrC in ultra-high vacuum, and the chemical interaction at the interface was monitored, also as a function of temperature (up to 1000 C). In the presentation, details of the chemical interaction and changes in the chemical environment of Pd and their relevance for TRISO fuel will be discussed.


Graphene: Material That Will Change The Future, Jigar Desai, Darryl Reese Apr 2011

Graphene: Material That Will Change The Future, Jigar Desai, Darryl Reese

Festival of Communities: UG Symposium (Posters)

Graphene is the most recent material discovered by scientists and is a star on the horizon of materials science and condensed matter physics. The one atom thick, two dimensional materials is an amazing conductor of electricity. Although graphene was not discovered completely until 2004, it has already revealed potential applications and scientists have begun researching ways of developing graphene products for the market. Only two products have been successfully produced so far, but scientists have encountered amazing results. This material has many potential applications in the real world and is about to change the future in a positive way.


Luminescent Ionic Liquid Crystals Based On Stilbazolium Moieties, William Mccurdy, Pradip K. Bhowmik Apr 2011

Luminescent Ionic Liquid Crystals Based On Stilbazolium Moieties, William Mccurdy, Pradip K. Bhowmik

Festival of Communities: UG Symposium (Posters)

Liquid crystals have become pivotally important to a variety of image displaying technologies. They have drawn much attention due to their ability to confer luminescent properties to a wide spectrum of image based devices. The purpose of this research is to describe a new methodology for an efficient synthesis of luminescent ionic liquid crystals including a discussion of their applications in the biological/medicinal sciences.


Serpentinite Weathering And Implications For Mars, Valerie Tu, Julie Baumeister, Rodney Metcalf, A. Olsen, Elisabeth Hausrath Apr 2011

Serpentinite Weathering And Implications For Mars, Valerie Tu, Julie Baumeister, Rodney Metcalf, A. Olsen, Elisabeth Hausrath

Festival of Communities: UG Symposium (Posters)

In the search for life on Mars near-surface soil environments may be important habitats for life accessible to future missions. Serpentinite rocks have been documented on Mars, as well as other clay minerals including smectite and kaolinites. Previous studies of soils formed on serpentinites on Earth have documented the formation of extensive clays. Serpentinites are additionally of interest as habitats for life such as methanogens. Here we examine weathering of serpentinites from bedrock to soil surface, as a potential route for the formation of clay minerals on Mars from abundant ultramafic minerals. We additionally test for the presence of Fe-oxidizing …


Halo Occupation Of Lyman-Break Galaxies, Saju Varghese, Ken Nagamine, Jason Jaacks, Jun-Hwan Choi Apr 2011

Halo Occupation Of Lyman-Break Galaxies, Saju Varghese, Ken Nagamine, Jason Jaacks, Jun-Hwan Choi

Festival of Communities: UG Symposium (Posters)

Lyman-break galaxies (LBGs) are star-forming galaxies found at high redshift that provide large amounts of information on early star and galaxy formation. We use large-scale cosmological smoothed-particle hydrodynamical simulations to simulate the physical properties of LBGs, such as stellar mass, star-formation rate, and magnitude. In particular, we focus on the question of which dark matter (DM) halos host LBGs. Our simulation suggests that only 1.74% of all DM halos host LBGs, though among the massive DM halos with mass Mhalo >1011.5 Msun, the fraction is 51.93%. The occupation number of LBGs ranges from 1 to 17 per halo.