Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Brigham Young University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 7771 - 7800 of 10987

Full-Text Articles in Entire DC Network

Westward Expansion Of The Eastern Pipistrelle (Pipistrellus Subflavus) In The United States, Including New Records From New Mexico, South Dakota, And Texas, Keith Geluso, Tony R. Mollhagen, Joel M. Tigner, Michael A. Bogan Jul 2005

Westward Expansion Of The Eastern Pipistrelle (Pipistrellus Subflavus) In The United States, Including New Records From New Mexico, South Dakota, And Texas, Keith Geluso, Tony R. Mollhagen, Joel M. Tigner, Michael A. Bogan

Western North American Naturalist

No abstract provided.

Go to article

Evaluating Lek Occupancy Of Greater Sage-Grouse In Relation To Landscape Cultivation In The Dakotas, Joe T. Smith, Lester D. Flake, Kenneth F. Higgins, Gerald D. Kobriger, Collin G. Homer Jul 2005

Evaluating Lek Occupancy Of Greater Sage-Grouse In Relation To Landscape Cultivation In The Dakotas, Joe T. Smith, Lester D. Flake, Kenneth F. Higgins, Gerald D. Kobriger, Collin G. Homer

Western North American Naturalist

Greater Sage-Grouse (Centrocercus urophasianus) have been declining in many states and provinces of North America, and North and South Dakota hold no exception to these declines. We studied effects of cultivated land on Greater Sage-Grouse lek abandonment in North and South Dakota. Landscape-level data were assessed using satellite imagery within a geographic information system. Comparisons were made of 1972–1976 and 1999–2000 percent cultivated and noncultivated land. These comparisons were made between land uses surrounding active leks versus inactive leks, active leks versus random locations, and abandoned regions versus active regions. The 1999–2000 imagery illustrated that percent cultivated land …

Go to article

Archaeological Record Of Native Fishes Of The Lower Colorado River: How To Identify Their Remains, Kenneth W. Gobalet, Thomas A. Wake, Kalie L. Hardin Jul 2005

Archaeological Record Of Native Fishes Of The Lower Colorado River: How To Identify Their Remains, Kenneth W. Gobalet, Thomas A. Wake, Kalie L. Hardin

Western North American Naturalist

Archaeological sites in the Salton Basin of southeastern California and along the lower Colorado River provided opportunities to determine which fish species were present prior to extirpations, environmental degradation, and the recession of Lake Cahuilla. These remains also represent the fishes exploited by Native Americans. Bonytail (Gila elegans), razorback sucker (Xyrauchen texanus), Colorado pikeminnow (Ptychocheilus lucius), striped mullet (Mugil cephalus), and machete (Elops affinis) have been recovered from 117 sites in the Salton Basin, once filled by the Colorado River forming Lake Cahuilla. Bonytail and razorback sucker comprise nearly 99% …

Go to article

Modeling Global Warming Scenarios In Greenback Cutthroat Trout (Oncorhynchus Clarki Stomias) Streams: Implications For Species Recovery, Scott J. Cooney, Alan P. Covich, Paul M. Lukacs, Amy L. Harig, Kurt D. Fausch Jul 2005

Modeling Global Warming Scenarios In Greenback Cutthroat Trout (Oncorhynchus Clarki Stomias) Streams: Implications For Species Recovery, Scott J. Cooney, Alan P. Covich, Paul M. Lukacs, Amy L. Harig, Kurt D. Fausch

Western North American Naturalist

Changes in global climate may exacerbate other anthropogenic stressors, accelerating the decline in distribution and abundance of rare species throughout the world. We examined the potential effects of a warming climate on the greenback cutthroat trout (Oncorhynchus clarki stomias), a resident salmonid that inhabits headwater streams of the central Rocky Mountains. Greenbacks are outcompeted at lower elevations by nonnative species of trout and currently are restricted to upper-elevation habitats where barriers to upstream migration by nonnatives are or have been established. We used likelihood-based techniques and information theoretics to select models predicting stream temperature changes for 10 streams …

Go to article

Collection Of Asian Tapeworm (Bothriocephalus Acheilognathi) From The Yampa River, Colorado, David Ward Jul 2005

Collection Of Asian Tapeworm (Bothriocephalus Acheilognathi) From The Yampa River, Colorado, David Ward

Western North American Naturalist

No abstract provided.

Go to article

A Modified Poisson–Boltzmann Analysis Of The Capacitance Behavior Of The Electric Double Layer At Low Temperatures, Douglas Henderson, L. B. Bhuiyan, C. W. Outhwaite Jul 2005

A Modified Poisson–Boltzmann Analysis Of The Capacitance Behavior Of The Electric Double Layer At Low Temperatures, Douglas Henderson, L. B. Bhuiyan, C. W. Outhwaite

Faculty Publications

The modified Poisson–Boltzmann theory is used to analyze the anomalous behavior of the electric double layer capacitance for small surface charge at low temperatures and densities. Good agreement is found with simulation and recent density-functional theory results. Negative adsorption is also found in line with theory and simulation. An unsatisfactory feature is the relatively poor structure in this region due to the inherent approximations in the theory. This feature is unimportant in relation to the capacitance results but has implications when calculating adsorption properties.

Go to article

Nesting Automated Design Modules In An Interconnected Framework, Jared Matthew Young Jul 2005

Nesting Automated Design Modules In An Interconnected Framework, Jared Matthew Young

Theses and Dissertations

This thesis seeks to extend the PDG methodology by developing a generalized formal method for nesting PDGs in an interconnected system. A procedure for decomposing an individual PDG into reusable modules will be defined and a software architecture will be presented which takes advantage of these reusable modules. This method breaks the PDG structure into discrete elements known as PDG objects, PDG modules and PDG services. Each of these elements forms a distinct unit of reuse and each can be seen as a "little" PDG. Two different industrial implementations of this method are presented. These examples show that it is …

Go to article

Effects Of Long-Term Storage On Quality Of Retail-Packaged Pinto Beans, C. M. Larson, A. R. Sloan, Lynn V. Ogden, Oscar A. Pike Jul 2005

Effects Of Long-Term Storage On Quality Of Retail-Packaged Pinto Beans, C. M. Larson, A. R. Sloan, Lynn V. Ogden, Oscar A. Pike

Faculty Publications

There is interest in storing low-moisture foods for long periods of time for uses such as personal preparedness, disaster relief efforts and space travel. Pinto beans in restaurant-sized No. 10 cans are available in the retail market, but work is needed to determine the effects of long-term storage on quality. The objective of this research was to investigate the quality of retail-packaged pinto beans held at ambient temperatures up to 32 years. Fifteen samples of pinto beans packaged in No. 10 cans, which were treated to remove oxygen, were obtained from donors. Samples ranged from <1 to 32 years in age. Prior to cooking, pinto bean samples were soaked in water containing varying levels of baking soda to standardize textural attributes.

Go to article

Hard-Sphere Radial Distribution Function Again, Andrij Trokhymchuk, Douglas Henderson, Ivo Nezbeda, Jan Jirsak Jul 2005

Hard-Sphere Radial Distribution Function Again, Andrij Trokhymchuk, Douglas Henderson, Ivo Nezbeda, Jan Jirsak

Faculty Publications

A theoretically based closed-form analytical equation for the radial distribution function, g(r), of a fluid of hard spheres is presented and used to obtain an accurate analytic representation. The method makes use of an analytic expression for the short- and long-range behaviors of g(r), both obtained from the Percus-Yevick equation, in combination with the thermodynamic consistency constraint. Physical arguments then leave only three parameters in the equation of g(r) that are to be solved numerically, whereas all remaining ones are taken from the analytical solution of the Percus-Yevick equation.

Go to article

Facing The Caree/Family Dichotomy: Traditional College Women's Perspectives, Lisa Michelle Leavitt Jul 2005

Facing The Caree/Family Dichotomy: Traditional College Women's Perspectives, Lisa Michelle Leavitt

Theses and Dissertations

This qualitative study explored the experience of 32 traditional college freshmen women as they sought to choose a career with the idea of balancing career and family in the future. A traditional woman was defined as a woman whose central value system and cultural mores emphasize homemaking and childrearing as their primary role. Guided interviews were conducted to obtain in-depth descriptions of participants' experience. The interviews were transcribed and interpreted using a synthesis of qualitative methods based on Kvale's method. The six themes were as follows: 1. The concept of balancing careers and family life is not being discussed or …

Go to article

Biofilm Removal Using Bubbles And Sound, Michael R. Parini Jul 2005

Biofilm Removal Using Bubbles And Sound, Michael R. Parini

Theses and Dissertations

Bacteria in biofilms adhere well to surfaces and are quite difficult to remove. Oral plaque is one example of a biofilm. Many researchers have studied ways to remove plaque and bacteria from surfaces. It has been found that the passage of a bubble across a surface to which bacteria has adhered can remove the bacteria from the surface. Biofilms of Streptococcus mutans were grown on glass coverslips as a simple model for oral plaque. The coverslips were mounted in a Plexiglas chamber filled with artificial saliva. A bubble stream was directed at the mounted biofilm. The velocity, gas fraction, median …

Go to article

Land Grabbers, Toadstool Worshippers, And The Sagebrush Rebellion In Utah, 1979-1981, Jedediah S. Rogers Jul 2005

Land Grabbers, Toadstool Worshippers, And The Sagebrush Rebellion In Utah, 1979-1981, Jedediah S. Rogers

Theses and Dissertations

In 1979, a handful of Nevada state officials sparked a movement to transfer the large unappropriated domain to the western states. For two years what became known as the Sagebrush Rebellion swept across the American West like brushfire, engaging westerners of all stripes in a heated dispute over the question of the public lands. In Utah, as elsewhere in the West, public officials, rural ranchers, miners, developers, academics, environmentalists, and concerned citizens joined the debate and staked sides. This episode underscored western relationships between people and nature and featured contests over competing ideologies in the West. But it probably did …

Go to article

Angiotensin Ii-Mediated Regulation Of The Human Angiotensin Ii Type 1 Receptor Gene, Xylophone Vijai Aasee Victor Jul 2005

Angiotensin Ii-Mediated Regulation Of The Human Angiotensin Ii Type 1 Receptor Gene, Xylophone Vijai Aasee Victor

Theses and Dissertations

The physiological responses of angiotensin II (Ang II) are mediated across the cell membrane through the angiotensin II type 1 receptor (AT1R), a heptahelical membrane protein coupled to trimeric G-proteins on the cytosolic side. AT1R on binding its ligand, Ang II, leads to downregulation of cell-surface receptor and also its mRNA. We have investigated whether the 3'- and 5'-untranslated regions of the human AT1R mRNA mediate the degradation of hAT1R mRNA by post-transcriptional mechanisms in human adrenocortical carcinoma cell line (H295R cells). Protein kinase C (PKC) activator, phorbol-12-myristate-13-acetate (PMA), showed that the downregulation of hAT1R mRNA is mediated by the …

Go to article

Is The Party Over? Unmarried Fatherhood And Drug And Alcohol Use, Jonathan A. Jarvis Jul 2005

Is The Party Over? Unmarried Fatherhood And Drug And Alcohol Use, Jonathan A. Jarvis

Theses and Dissertations

Using waves two and three of the National Survey of Adolescent Males (1990 and 1995) I examine the effects of marriage, paternity and father involvement on the use of drugs and alcohol by young men. Despite the importance of fatherhood as an adult role, I argue that commitment to the role of fatherhood and not paternity itself is what alters behavior. I hypothesize that young men who assume responsibility for fathering their children are more likely to reduce their drug and alcohol use over time than young men who father children but do not assume the role of parent. Results …

Go to article

Visualizing And Interacting With Externally Coupled Engineering Analysis Results, Paul Frederick Nelson Jul 2005

Visualizing And Interacting With Externally Coupled Engineering Analysis Results, Paul Frederick Nelson

Theses and Dissertations

Visualizing and interacting with engineering analysis results can provide valuable insights into a system's performance and aid in engineering decision-making. Currently, the majority of analysis codes are developed as isolated solutions focusing only on the most prominent physical influence to a system, such as thermal, structural, fluid, etc. Frequently, more than one of these physical influences combined to force engineers to evaluate complex, coupled systems. Coupled analysis codes are becoming more common place tools for engineers demanding high fidelity simulations of complex systems. External code coupling solutions are emerging to permit generic coupling of separate, world class CAE solvers thus …

Go to article

Development Of A Model For The Kinetics And Mechanism Of Nitrogenase, Phillip E. Wilson Jul 2005

Development Of A Model For The Kinetics And Mechanism Of Nitrogenase, Phillip E. Wilson

Theses and Dissertations

Nitrogenase has a central role in the global nitrogen cycle as the enzyme that catalyzes the reduction of atmospheric N2 to NH3. Fixed nitrogen is generally limiting in the environment and in agriculture, so nitrogenase has received much attention as an alternative to nitrogen fertilizers. Characterizing the mechanism of nitrogenase is the goal of this work. The molybdenum nitrogenase enzyme system is comprised of the MoFe protein and the Fe protein. Interactions between these proteins and nucleotides are crucial to catalysis. An important approach to characterize these interactions is to correlate the kinetics of nitrogenase catalysis to a mechanism based …

Go to article

Homologous Strand Exchange And Dna Helicase Activities In Plant Mitochondria, Daqing Song Jul 2005

Homologous Strand Exchange And Dna Helicase Activities In Plant Mitochondria, Daqing Song

Theses and Dissertations

Homologous recombination is critical for generating genetic variation in living organisms by exchange and rearrangement of DNA. Most of our knowledge about homologous recombination is limited to processes in bacteria or in eukaryotic nuclei. In E. coli, homologous recombination is dependent on the RecA protein. Higher plant chloroplasts have RecA-like strand exchange activity. However, little is known about these mechanisms in higher plant mitochondria. I have detected a RecA-like strand exchange activity in soybean mitochondria. This activity forms joint molecules in the presence of ATP, Mg2+, and homologous DNA substrates. In addition, the E. coli single-stranded DNA binding (SSB) protein …

Go to article

Genetic Analysis Of Conserved Residues In Phou Of Escherichia Coli, Stewart G. Gardner Jul 2005

Genetic Analysis Of Conserved Residues In Phou Of Escherichia Coli, Stewart G. Gardner

Theses and Dissertations

The Pho regulon is controlled by the PstSCAB transporter, PhoU, and the two-component proteins, PhoB and PhoR. PhoU is a negative regulator of the Pho regulon under phosphate-replete conditions. How PhoU functions is unknown. Many PhoU homologues are found widely throughout prokaryotic domains. There are several conserved amino acid residues in the PhoU protein. It is hypothesized that these residues play an important role in the function of PhoU. To test this hypothesis, several site directed mutations in the phoU gene have been produced with single amino acid changes in conserved residues. After testing these mutants, it was found that …

Go to article

Sibling Influence On Adolescent Cigarette, Alcohol, And Marijuana Use, Benjamin G. Gibbs Jul 2005

Sibling Influence On Adolescent Cigarette, Alcohol, And Marijuana Use, Benjamin G. Gibbs

Theses and Dissertations

The purpose of this study is to estimate the association between sibling drug use and adolescent alcohol, cigarette, and marijuana use. Research is conducted using survey data from a probability sample of 4,987 adolescents in grades 9–12 in Utah. To account for the limited frequency of drug use among respondents, Poisson regression is used to estimate models for each type of drug. In support of current literature, findings indicate that having a sibling who uses drugs increases the frequency of drug use substantially, even when peer influences are taken into account. Significant sibling associations with adolescent drug use found in …

Go to article

Investigation Of The Mechanisms Of Ozone-Mediated Viral Inactivation, Seiga Ohmine Jul 2005

Investigation Of The Mechanisms Of Ozone-Mediated Viral Inactivation, Seiga Ohmine

Theses and Dissertations

Previous studies have established that ozone-oxygen mixtures can be used to inactivate a variety of microorganisms including bacteria, fungi and viruses. Ozone is a potent reactive oxygen species (ROS) that rapidly decays into a variety of additional short half-life ROS which have been shown to cause oxidative damage to biological molecules. I hypothesize that controlled ozone exposure and the subsequent generation of additional ROS would reduce viral infectivity by lipid and/or protein peroxidation. A proprietary ozone-oxygen delivery system was used to inactivate a series of enveloped [herpes simplex virus type-1 strain McIntyre (HSV-1), vaccinia strain Elstree (VAC), vesicular stomatitis virus …

Go to article

A Mathematical Model Of Adhesion Interactions Between Living Cells, Casey P. Johnson Jul 2005

A Mathematical Model Of Adhesion Interactions Between Living Cells, Casey P. Johnson

Theses and Dissertations

This thesis presents a simple force-based model of moving and interacting cells that incorporates a realistic description of cell adhesion and applies it to a system of spherical cells. In addition, several results in matrix theory are proved with the end of showing that the equations produced by the model uniquely determine the motion of the system or cells.

Go to article

500 Essential English Words For Esl Missionaries, Carrie A. Thompson Jul 2005

500 Essential English Words For Esl Missionaries, Carrie A. Thompson

Theses and Dissertations

In order to help ESL missionaries teach the gospel from their hearts using their own words, I have developed a 500-word list of core gospel vocabulary in English. To enhance the 500-word list, I included a lexicon with simple definitions, some grammatical information, and examples of the words in context. The resulting product complies with the standards for master's projects established by the Department of Linguistics and English Language. Published literature shows that the development of specialized corpora can be beneficial for students learning another language. Additionally, specialized corpora act as a catalyst for in-depth vocabulary analysis and the development …

Go to article

Microbial And Chemical Affects On Leachate From Calcareous Soils Treated With Wastewater Effluent, Craig M. Paul Jul 2005

Microbial And Chemical Affects On Leachate From Calcareous Soils Treated With Wastewater Effluent, Craig M. Paul

Theses and Dissertations

Increasing human populations are placing greater strain on water resources, prompting the use of treated wastewater effluent for irrigation in some areas, including the desert regions of the Western United States. To determine the potential effects of using secondary effluent for irrigation, we applied wastewater effluent and irrigation waters to natural and artificially constructed calcareous soils in greenhouse and field lysimeters, and in soil columns. The leachate from one field lysimeter contained increased fecal coliform counts than the effluent. Leachate coliform counts were decreased or not significantly changed in two field lysimeters. Electrical conductivity (EC), sodium adsorption ratio (SAR), chloride …

Go to article

Tauser Killed Both Dogs And Other Suburban American Family Folklore, Kristina Whitley Gashler Jul 2005

Tauser Killed Both Dogs And Other Suburban American Family Folklore, Kristina Whitley Gashler

Theses and Dissertations

This thesis attempts to answer the questions "What purposes do family pets and the narratives we tell about them serve in modern American society?" and "What do these stories tell us about what Americans value and about where we locate our ‘value center’?" In Chapter 1, I discuss how Americans define loyalty in our pets now that our animals generally no longer help us work. I conclude that since the shift from agricultural to suburban settings, animals prove their loyalty individually and in human-like ways, rather than as "good" members of their own species, but at the same time because …

Go to article

Effectively Using Recurrently-Connected Spiking Neural Networks, Eric Goodman, Dan A. Ventura Jul 2005

Effectively Using Recurrently-Connected Spiking Neural Networks, Eric Goodman, Dan A. Ventura

Faculty Publications

Recurrently-connected spiking neural networks are difficult to use and understand because of the complex nonlinear dynamics of the system. Through empirical studies of spiking networks, we deduce several principles which are critical to success. Network parameters such as synaptic time delays and time constants and the connection probabilities can be adjusted to have a significant impact on accuracy. We show how to adjust these parameters to fit the type of problem.

Go to article

“All Things Denote There Is A God”: Seeing Christ In The Creation, Bruce A. Roundy, Robert J. Norman Jul 2005

“All Things Denote There Is A God”: Seeing Christ In The Creation, Bruce A. Roundy, Robert J. Norman

Religious Educator: Perspectives on the Restored Gospel

No abstract provided.

Go to article

Time Invariance And Liquid State Machines, Eric Goodman, Dan A. Ventura Jul 2005

Time Invariance And Liquid State Machines, Eric Goodman, Dan A. Ventura

Faculty Publications

Time invariant recognition of spatiotemporal patterns is a common task of signal processing. Liquid state machines (LSMs) are a paradigm which robustly handle this type of classification. Using an artificial dataset with target pattern lengths ranging from 0.1 to 1.0 seconds, we train an LSM to find the start of the pattern with a mean absolute error of 0.18 seconds. Also, LSMs can be trained to identify spoken digits, 1-9, with an accuracy of 97.6%, even with scaling by factors ranging from 0.5 to 1.5.

Go to article

Phylogeny And Biogeography Of Ice Crawlers (Insecta: Grylloblattodea): Evidence From Six Molecular Loci, Karl J. Jarvis Jun 2005

Phylogeny And Biogeography Of Ice Crawlers (Insecta: Grylloblattodea): Evidence From Six Molecular Loci, Karl J. Jarvis

Theses and Dissertations

Ice crawlers (Insecta: Grylloblattodea) are rarely encountered insects that consist of five genera representing 26 species from North America and Asia. Asian grylloblattids are the most diverse, but North American ice crawlers (genus Grylloblatta) are known for their adaptation to cold conditions. Phylogenetic relationships among grylloblattid species and genera are not known. Late Pleistocene glaciations had a major effect on the current Grylloblatta distribution, because their specific habitat requirements restrict them to small geographical areas. Six genes were sampled in 37 individuals for 18S rRNA, 28S rRNA, histone 3, 12S rRNA, 16S rRNA, and cytochrome oxidase II (COII) from 27 …

Go to article

Crustacean Phylogenetic Systematics And Opsin Evolution, Megan L. Porter Jun 2005

Crustacean Phylogenetic Systematics And Opsin Evolution, Megan L. Porter

Theses and Dissertations

Composed of a chromophore bound to an integral membrane protein (opsin), visual pigments are phenotypically characterized by the wavelength of maximal absorption (λmax). The underlying molecular mechanism controlling λmax is the interaction between the opsin amino acid sequence and the chromophore. While a plethora of studies have looked at structure/function relationships in vertebrate opsins, fewer studies have investigated similar issues in invertebrates. Furthermore, those few studies undertaken in invertebrate systems suggest different mechanisms of spectral tuning and photoactivation compared to vertebrate systems. This dissertation research is focused on expanding our knowledge of opsin evolution in invertebrate systems, particularly from non-insect …

Go to article

Assessment Of Cell Death Parameters In Bovine Parvovirus-Infected Ebtr Cells, Lubna Salah Eldin Abdel Latif Jun 2005

Assessment Of Cell Death Parameters In Bovine Parvovirus-Infected Ebtr Cells, Lubna Salah Eldin Abdel Latif

Theses and Dissertations

Bovine parvovirus (BPV) is a helper-independent parvovirus. It has a small icosahedral capsid with a single stranded DNA genome. It is a highly stable virus with a narrow host range. It causes acute gastroenteritis in calves. It is considered to be a cytolytic virus because it kills the host cells. However, the mechanism by which the virus causes cell death is not known. The work described in this thesis assessed different parameters of cell death in BPV infected embryonic bovine tracheal (EBTr) cells. There are several ways for viruses to induce cell death. Viruses can induce apoptosis in the infected …

Go to article

First Prev Next Last