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 7291 - 7320 of 10987

Full-Text Articles in Entire DC Network

Potential Contribution Of Respiration By Anabrus Simplex (Mormon Crickets) To Net Co2 Exchange In Three Great Basin Ecosystems, A. Joshua Leffler, Michael S. Peek, Larry Hipps, Sasha Ivans, Ronald J. Ryel, Martyn M. Caldwell Mar 2007

Potential Contribution Of Respiration By Anabrus Simplex (Mormon Crickets) To Net Co2 Exchange In Three Great Basin Ecosystems, A. Joshua Leffler, Michael S. Peek, Larry Hipps, Sasha Ivans, Ronald J. Ryel, Martyn M. Caldwell

Western North American Naturalist

Disturbance events can significantly influence net CO2 exchange (NCE) in ecosystems. High densities of Anabrus simplex (Mormon crickets) periodically afflict large areas of the western USA; their sheer numbers could make them a significant source of CO2. We modeled cricket respiration at the ecosystem level using air and body temperatures and insect gas exchange measurements. Cricket CO2 efflux values were compared to ecosystem CO2 flux from eddy covariance measurements in 3 Great Basin ecosystems: a juniper woodland, a sagebrush shrubland, and a crested wheatgrass pasture. Mean respiration from Mormon crickets was 0.96 g CO2 …

Go to article

Dispersal And Extraterritorial Movements Of Swift Foxes (Vulpes Velox) In Northwestern Texas, Kerry L. Nicholson, Warren B. Ballard, Brady K. Mcgee, Heather A. Whitlaw Mar 2007

Dispersal And Extraterritorial Movements Of Swift Foxes (Vulpes Velox) In Northwestern Texas, Kerry L. Nicholson, Warren B. Ballard, Brady K. Mcgee, Heather A. Whitlaw

Western North American Naturalist

Dispersal plays an important role in the population dynamics of many carnivores, yet little information exists about the dispersal and movement patterns of swift foxes (Vulpes velox). We radio-collared and monitored 68 swift foxes for dispersal at 2 study sites in northwestern Texas from January 2002 to April 2004. Dispersal distance for juveniles (13.1 ± 0.3 km, s), adults (10 ± 4.7 km) and transients (25.4 ± 9.1 km) did not differ by age class (F = 1.49, df = 2, P = 0.24) or sex (F = 0.23, df = 1, P = 0.63) …

Go to article

Genetic Analysis Of A Recently Discovered Population Of The Least Chub (Iotichthys Phlegethontis), Karen E. Mock, Lee S. Bjerregaard Mar 2007

Genetic Analysis Of A Recently Discovered Population Of The Least Chub (Iotichthys Phlegethontis), Karen E. Mock, Lee S. Bjerregaard

Western North American Naturalist

No abstract provided.

Go to article

Anthropogenic Threat To The Desert Tortoise (Gopherus Agassizii): Litter In The Mojave Desert, Andrew D. Walde, Meagan L. Harless, David K. Delaney, Larry L. Pater Mar 2007

Anthropogenic Threat To The Desert Tortoise (Gopherus Agassizii): Litter In The Mojave Desert, Andrew D. Walde, Meagan L. Harless, David K. Delaney, Larry L. Pater

Western North American Naturalist

No abstract provided.

Go to article

Noteworthy Record Of The Tayra (Carnivora: Mustelidae: Eira Barbara) In The Sierra Gorda Biosphere Reserve, Querétaro, México, Carlos A. López González, Daniel R. Aceves Lara Mar 2007

Noteworthy Record Of The Tayra (Carnivora: Mustelidae: Eira Barbara) In The Sierra Gorda Biosphere Reserve, Querétaro, México, Carlos A. López González, Daniel R. Aceves Lara

Western North American Naturalist

No abstract provided.

Go to article

Characteristics Of Columbia Spotted Frog (Rana Luteiventris) Oviposition Sites In Northeastern Oregon, Usa, Christopher A. Pearl, Michael J. Adams, Wendy H. Wente Mar 2007

Characteristics Of Columbia Spotted Frog (Rana Luteiventris) Oviposition Sites In Northeastern Oregon, Usa, Christopher A. Pearl, Michael J. Adams, Wendy H. Wente

Western North American Naturalist

Several western ranid frogs possess a unique strategy of breeding communally over a short temporal window and reusing oviposition sites between years. However, little is published on the characteristics of oviposition sites selected by these explosive breeders. The Columbia spotted frog (Rana luteiventris) is native to northwestern North America and is of conservation concern in the southern portions of its range. As part of a study examining relationships between livestock grazing and R. luteiventris habitat, we assessed characteristics of the species' oviposition sites in 25 fishless ponds in northeastern Oregon. Oviposition sites were generally in shallow water (<25 cm) close to shore and tended to be in the northeastern portion of ponds. Oviposition sites were found more frequently over heavily vegetated substrates and in areas of less substrate slope and shade than random points in littoral zones. We did not quantify temperature differences within ponds, but the patterns we documented are consistent with preferential use of warmer microhabitats for oviposition.

Go to article

Forest-Floor Treatments In Arizona Ponderosa Pine Restoration Ecosystems: No Short-Term Effects On Plant Communities, Scott R. Abella, W. Wallace Covington Mar 2007

Forest-Floor Treatments In Arizona Ponderosa Pine Restoration Ecosystems: No Short-Term Effects On Plant Communities, Scott R. Abella, W. Wallace Covington

Western North American Naturalist

Leaf litter accumulation during fire exclusion and increases in tree density in postsettlement southwestern Pinus ponderosa forests may limit the establishment of understory vegetation. We performed an experiment in P. ponderosa forests of northern Arizona to ascertain plant community responses to forest-floor scarification and Oi removal on thirty-six 100-m2 plots overlaid on an existing ecological restoration experiment that involved tree thinning and prescribed burning. Constrasting with findings from many other forest types, forest-floor treatments had no effect on community diversity or composition during the 2-year experiment. Sørensen similarities were as high as 97% between posttreatment years within treatments; and …

Go to article

Sex And The Lonely Atriplex, D. Carl Freeman, E. Durant Mcarthur, Kathleen J. Miglia, Michelle J. Nilson, Michelle L. Brown Mar 2007

Sex And The Lonely Atriplex, D. Carl Freeman, E. Durant Mcarthur, Kathleen J. Miglia, Michelle J. Nilson, Michelle L. Brown

Western North American Naturalist

No abstract provided.

Go to article

A Comparison Of Mosquito Consumption And Prey Selection Between Least Chub (Iotichthys Phlegethontis) And Western Mosquitofish (Gambusia Affinis), Eric J. Billman, Eric J. Wagner, Ronney E. Arndt Mar 2007

A Comparison Of Mosquito Consumption And Prey Selection Between Least Chub (Iotichthys Phlegethontis) And Western Mosquitofish (Gambusia Affinis), Eric J. Billman, Eric J. Wagner, Ronney E. Arndt

Western North American Naturalist

We compared mosquito consumption and prey selection between least chub (Iotichthys phlegethontis) and western mosquitofish (Gambusia affinis) to determine the potential of least chub as an indigenous replacement for mosquito control in Utah. Mosquito consumption was compared between the 2 species in 2 experiments. The first tested consumption at 3 ratios of pupae and larvae (Culex sp.; 1:3, 3:4, and 1:1), and the second tested consumption at varying densities of larvae (967 larvae · m−3, 1354 larvae · m−3, and 2258 larvae · m−3 [30, 42, and 70 larvae per …

Go to article

Grit Size Preferences And Confirmation Of Ingested Lead Pellets In Chukars (Alectoris Chukar), Randy T. Larsen, Jerran T. Flinders, Dean L. Mitchell, Ernest R. Perkins Mar 2007

Grit Size Preferences And Confirmation Of Ingested Lead Pellets In Chukars (Alectoris Chukar), Randy T. Larsen, Jerran T. Flinders, Dean L. Mitchell, Ernest R. Perkins

Western North American Naturalist

No abstract provided.

Go to article

The Niemann-Pick Type C2 Protein Loads Isoglobotrihexosylceramide Onto Cd1d Molecules And Contributes To The Thymic Selection Of Nkt Cells, Paul B. Savage, Nicolas Schrantz, Yuval Sagiv, Yang Liu, Albert Bendelac, Luc Teyton Mar 2007

The Niemann-Pick Type C2 Protein Loads Isoglobotrihexosylceramide Onto Cd1d Molecules And Contributes To The Thymic Selection Of Nkt Cells, Paul B. Savage, Nicolas Schrantz, Yuval Sagiv, Yang Liu, Albert Bendelac, Luc Teyton

Faculty Publications

The Niemann-Pick type C2 (NPC2) protein is a small, soluble, lysosomal protein important for cholesterol and sphingolipid transport in the lysosome. The immunological phenotype of NPC2-deficient mice was limited to an impaired thymic selection of Valpha 14 natural killer T cells (NKT cells) and a subsequent reduction of NKT cells in the periphery. The remaining NKT cells failed to produce measurable quantities of interferon-gamma in vivo and in vitro after activation with alpha-galactosylceramide. In addition, thymocytes and splenocytes from NPC2-deficient mice were poor presenters of endogenous and exogenous lipids to CD1d-restricted Valpha 14 hybridoma cells. Importantly, we determined that similar …

Go to article

The Role Of Stat And The Jak/Stat Pathway In Mediating The Effects Of Interleukin-6 On Star Expression, Janae Strickland Mar 2007

The Role Of Stat And The Jak/Stat Pathway In Mediating The Effects Of Interleukin-6 On Star Expression, Janae Strickland

Theses and Dissertations

Cortisol, a hormone produced by a hormone produced by the adrenal gland, is responsible for many regulatory functions in the body. Cortisol release is mediated by adrenocorticotrophic hormone, or ACTH, through the hypothalamus-pituitary-adrenal or HPA axis. This HPA axis is the major release pathway used during acute stress, during which the levels of ACTH parallel those of cortisol. However, in states of chronic stress, the level of ACTH drops dramatically, while cortisol remains high. This study focuses on the pathway of cortisol release during these chronic stress states, specifically examining the role of IL-6 with respect to STATs and the …

Go to article

Fresh Water Ecology Unit For Secondary Education Science Courses, Eric L. Hyer Mar 2007

Fresh Water Ecology Unit For Secondary Education Science Courses, Eric L. Hyer

Theses and Dissertations

Science means “to know", a process for gaining knowledge and an understanding of the natural world. Students need to be involved in active learning. In other words, they must do science, not just hear about it. Good science encourages students to gain knowledge by doing science: observing, questioning, exploring, making and testing hypotheses, comparing predictions, evaluating data, and communicating conclusions. This unit plan is designed to incorporate the components of fresh water, ecology, water quality, and a class-wide science project. Each lesson addresses selected standards from the state core curriculum and has specific objectives that are tied to the learning …

Go to article

Analyses Of Greater Sage-Grouse (Centrocercus Urophasianus) Translocation Release Methods And Chick Survival In Strawberry Valley, Utah, Jordan P. Hennefer Mar 2007

Analyses Of Greater Sage-Grouse (Centrocercus Urophasianus) Translocation Release Methods And Chick Survival In Strawberry Valley, Utah, Jordan P. Hennefer

Theses and Dissertations

Manuscript No. 1 Recent research has indicated that low nest success and juvenile survival of Greater Sage-Grouse may be responsible for population declines. Recent technological advances in micro-transmitters have made radio-telemetry studies on Sage-Grouse chicks more common. Radio-telemetry enables monitoring of individual chicks and broods during a critical period of their life history. The exact cause of low chick recruitment in Strawberry Valley has not been well understood. In 2006, a chick mortality study using micro-transmitters was initiated to (1) determine the causes of chick mortality, (2) calculate overall chick survival, (3) compare chick survival in the Strawberry Valley population …

Go to article

Modeling Dissolved Oxygen In Lake Powell Using Ce-Qual-W2, Nicholas Trevor Williams Mar 2007

Modeling Dissolved Oxygen In Lake Powell Using Ce-Qual-W2, Nicholas Trevor Williams

Theses and Dissertations

Water quality models in the Colorado River Basin have been developed for the basin, river, and individual reservoirs. They are used to support water quality programs within the basin. The models are periodically reviewed and updated to improve the accuracy of simulations. Improving the usefulness of the Lake Powell model, one of the key reservoirs in the basin, is the subject of this study. Lake Powell is simulated using a hydrodynamic and water quality model, CE-QUAL-W2. Previously the model has been used at Lake Powell to simulate hydrodynamics, temperature, and total dissolved solids with a reasonable degree of accuracy. An …

Go to article

No. 28 Mormon Pacific Historical Society Mar 2007

No. 28 Mormon Pacific Historical Society

Mormon Pacific Historical Society

No abstract provided.

Go to article

Kaingalotu: Tongan Saints In The Diaspora Mar 2007

Kaingalotu: Tongan Saints In The Diaspora

Mormon Pacific Historical Society

No abstract provided.

Go to article

Abraham Kaleimahoe Fernandez: Hawaiian Saint And Royalist, 1857-1915 Mar 2007

Abraham Kaleimahoe Fernandez: Hawaiian Saint And Royalist, 1857-1915

Mormon Pacific Historical Society

No abstract provided.

Go to article

A Simulation-Based Approach For Evaluating Gene Expression Analyses, Carly Ruth Pendleton Mar 2007

A Simulation-Based Approach For Evaluating Gene Expression Analyses, Carly Ruth Pendleton

Theses and Dissertations

Microarrays enable biologists to measure differences in gene expression in thousands of genes simultaneously. The data produced by microarrays present a statistical challenge, one which has been met both by new modifications of existing methods and by completely new approaches. One of the difficulties with a new approach to microarray analysis is validating the method's power and sensitivity. A simulation study could provide such validation by simulating gene expression data and investigating the method's response to changes in the data; however, due to the complex dependencies and interactions found in gene expression data, such a simulation would be complicated and …

Go to article

Calibration Procedure For A Microscopic Traffic Simulation Model, Carole Turley Mar 2007

Calibration Procedure For A Microscopic Traffic Simulation Model, Carole Turley

Theses and Dissertations

The inputs to a microscopic traffic simulation model generally include quantitative, but immeasurable data describing driver behavior and vehicle performance characteristics. Engineers often use default values for parameters such as car-following sensitivity and gap acceptance because it can be difficult to obtain accurate estimates for these parameters. While recent research has indicated that the accuracy of a simulation model can significantly improve if driver behavior parameters are calibrated to local data, this is not a typical practice. Manual calibration of these parameters is often too time-consuming to be cost-effective. Researchers have applied automated calibration procedures using genetic algorithms to these …

Go to article

Ecology Of Culturable Organisms At Rozel Point, Great Salt Lake, Utah, Emily Sarah Haws Mar 2007

Ecology Of Culturable Organisms At Rozel Point, Great Salt Lake, Utah, Emily Sarah Haws

Theses and Dissertations

The study of organisms from extreme environments is an emerging field of research with applications to multiple scientific areas. One of these extreme environments is Great Salt Lake (GSL), whose microbiology has yet to be extensively studied. This dynamic and unique environment offers an excellent opportunity to increase understanding of hypersaline ecology. Cultivation of microorganisms remains an important part of ecology research, as it is essential for understanding microbial physiology. We report here the culturing and characterization of isolates from Rozel Point, located on the northeastern shore of Great Salt Lake. This site was chosen because of the presence of …

Go to article

Parameter Importance Of An Analytical Model For Transport In The Vadose Zone, Tanner Hans Bushnell Mar 2007

Parameter Importance Of An Analytical Model For Transport In The Vadose Zone, Tanner Hans Bushnell

Theses and Dissertations

The American Society of Testing and Materials (ASTM) has established a three tier risk-based corrective action (RBCA) program for cleaning up petroleum release sites, which is supported by the Environmental Protection Agency. RBCA programs make the cleanup of spill sites more efficient by requiring additional site information only when a more accurate risk assessment is needed. For spill sites that do not pass the first tier general assessment, a Tier 2 evaluation involving site specific information and screening level models to assess the potential risk must be conducted. Screening level models generally require site specific input parameters. To increase efficiency …

Go to article

A High-Resolution Microscopic Electrical Impedance Imaging Modality: Scanning Impedance Imaging, Hongze Liu Mar 2007

A High-Resolution Microscopic Electrical Impedance Imaging Modality: Scanning Impedance Imaging, Hongze Liu

Theses and Dissertations

Electrical impedance imaging is an imaging technique which has the capability of revealing the spatial distribution of the electrical impedance inside biological tissues. Classical electrical impedance imaging including Electrical Impedance Tomography (EIT) typically has low resolution. Advances in electrical impedance imaging typically involve methods that either increase image resolution or image contrast. This study investigates the possibility of the resolution improvement for electrical impedance imaging using motion, and presents a novel high-resolution and calibrated impedance imaging method called Scanning electrical Impedance Imaging (SII). SII uses an electrical probe held at a known voltage and scanned over a thin sample immersed …

Go to article

Pyridinium Bis-Retinoids: Extraction, Synthesis, And Folate Coupling, Mary Allison Alvarez Mar 2007

Pyridinium Bis-Retinoids: Extraction, Synthesis, And Folate Coupling, Mary Allison Alvarez

Theses and Dissertations

This thesis is divided into two parts.Part I describes the organic extraction, separation, and liquid chromatographic-mass spectrometric analysis of chromophores from human and bovine retinal pigment epithelium. Flurorophores in the retinal pigment epithelium have been implicated in age related macular degeneration. In addition, the synthesis and characterization of a number of bis-retinoid type compounds that may potentially be found in such extracts, or that may be used for insight into pyridinium bis-retinoid reactivity, was accomplished.Part II describes a study of pyridinium bis-retinoid-folic acid coupling with respect to linker type, linker length, and nature of the linkage. Folic acid has been …

Go to article

The Effect Of Birth Order On Infant Injury, Heather L. Van Duker Mar 2007

The Effect Of Birth Order On Infant Injury, Heather L. Van Duker

Theses and Dissertations

Pediatric injury is both common and expensive. Finding ways to prevent pediatric injury is a major public health concern. Many studies have investigated various aspects of pediatric injury, and some suggest that birth order may be an important risk factor for pediatric injury. This study further examined the relationship of birth order with pediatric injury, specifically studying the association of birth order with emergency department-attended infant injury while adjusting for other important family and individual covariates. Data for analysis included Utah birth certificate, death certificate, and hospital emergency department datasets, which were probabilistically linked to obtain complete demographic and injury …

Go to article

Hope For The Fatherless?: A Grounded Interpretive Approach, Anna Manja Larcher Mar 2007

Hope For The Fatherless?: A Grounded Interpretive Approach, Anna Manja Larcher

Theses and Dissertations

Psychology's literature regarding fatherlessness is not only grim, mainly pointing out the negative consequences of fatherlessness, but it also does not provide much specific information about fatherless individuals' experiences. A pilot study revealed that fatherless individuals do not always suffer from the loss of their father and that they also have the ability to overcome the negative consequences commonly associated with father loss. The research questions for this study presented themselves naturally after reviewing the literature and after considering the results of my pilot study, namely, “What do fatherless individuals actually experience in being fatherless, and what is the nature …

Go to article

The Role Of Prolactin In Ccl28 Regulation, Jennie Hyde Mar 2007

The Role Of Prolactin In Ccl28 Regulation, Jennie Hyde

Theses and Dissertations

Infants are born with naive immune systems, making them susceptible to a variety of infections. In order to protect the newborn infant it is important that mothers be able to pass protective IgA antibodies to their infants through breast milk. B cells that produce IgA enter the mammary tissue during lactation and secrete IgA into the milk. During pregnancy, the mammary tissue expresses high levels of chemokines, molecules that allow lymphocytes to selectively home to specific tissues. The chemokine CCL28 has been shown to be upregulated during both pregnancy and lactation, and is vital for the ability of IgA-producing B …

Go to article

Federated Searching: Do Undergraduates Prefer It And Does It Add Value?, C. Jeffrey Belliston, Jared L. Howland Mar 2007

Federated Searching: Do Undergraduates Prefer It And Does It Add Value?, C. Jeffrey Belliston, Jared L. Howland

Faculty Publications

PDF of Powerpoint Presentation on federated searching. This presentation was given at the National ACRL Virtual Conference in Baltimore, Maryland.

Go to article

A Coarse Grain Model For Dna, Thomas A. Knotts, Nitin Rathore, David C. Schwartz, Juan J. De Pablo Feb 2007

A Coarse Grain Model For Dna, Thomas A. Knotts, Nitin Rathore, David C. Schwartz, Juan J. De Pablo

Faculty Publications

Understanding the behavior of DNA at the molecular level is of considerable fundamental and engineering importance. While adequate representations of DNA exist at the atomic and continuum level, there is a relative lack of models capable of describing the behavior of DNA at mesoscopic length scales. We present a mesoscale model of DNA that reduces the complexity of a nucleotide to three interactions sites, one each for the phosphate, sugar, and base, thereby rendering the investigation of DNA up to a few microns in length computationally tractable. The charges on these sites are considered explicitly. The model is parametrized using …

Go to article

A Coarse Grain Model For Dna, Thomas A. Knotts Iv, Nitin Rathore, David C. Schwartz, Juan J. De Pablo Feb 2007

A Coarse Grain Model For Dna, Thomas A. Knotts Iv, Nitin Rathore, David C. Schwartz, Juan J. De Pablo

Faculty Publications

Understanding the behavior of DNA at the molecular level is of considerable fundamental and engineering importance. While adequate representations of DNA exist at the atomic and continuum level, there is a relative lack of models capable of describing the behavior of DNA at mesoscopic length scales. We present a mesoscale model of DNA that reduces the complexity of a nucleotide to three interactions sites, one each for the phosphate, sugar, and base, thereby rendering the investigation of DNA up to a few microns in length computationally tractable. The charges on these sites are considered explicitly. The model is parametrized using …

Go to article

First Prev Next Last