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 2251 - 2280 of 11004

Full-Text Articles in Entire DC Network

End Matter, Vol. 79 No. 2 Jul 2019

End Matter, Vol. 79 No. 2

Western North American Naturalist

No abstract provided.

Go to article

Do Cytotypes Of Black Flies Of The Simulium Arcticum Complex (Diptera: Simuliidae) Arise From Sibling Species?, Gerald F. Shields, D. Grant Hokit Jul 2019

Do Cytotypes Of Black Flies Of The Simulium Arcticum Complex (Diptera: Simuliidae) Arise From Sibling Species?, Gerald F. Shields, D. Grant Hokit

Western North American Naturalist

To better understand the evolutionary radiation of the Simulium arcticum complex of black flies (Diptera: Simuliidae), we compared the geographic distributions of present-day larvae to their sex-chromosome diversity. We used the 5 known data sets including collections and sex-chromosome analysis from 307 geographic locations of 31 taxa of approximately 20,000 larvae from throughout the geographic range of distribution of the complex, from Alaska, western Canada, and the western United States to southern California, Arizona, and New Mexico. Siblings (reproductively isolated in sympatry) have considerably larger geographic distributions than do cytotypes (not reproductively isolated in sympatry), suggesting that the former may …

Go to article

Front Matter, Vol. 79 No. 2 Jul 2019

Front Matter, Vol. 79 No. 2

Western North American Naturalist

No abstract provided.

Go to article

Effects Of Broadcasting Calls On Detection Probability In Occupancy Analyses Of Multiple Raptor Species, Jeremy A. Baumgardt, Michael L. Morrison, Leonard A. Brennan, Tyler A. Campbell Jul 2019

Effects Of Broadcasting Calls On Detection Probability In Occupancy Analyses Of Multiple Raptor Species, Jeremy A. Baumgardt, Michael L. Morrison, Leonard A. Brennan, Tyler A. Campbell

Western North American Naturalist

For population studies that rely on aural or visual observations of individuals, methods that induce a detectable response can greatly improve sample sizes and reduce costs. Numerous authors have reported improved detections using broadcast surveys in forested areas for various species of raptors; however, to our knowledge, none have attempted to quantify the effects of broadcast surveys on the detection probability (p) in the context of an occupancy study for multiple species. Our objective was to determine whether broadcasting conspecific and heterospecific calls (broadcast surveys) would increase p of raptor species compared to passive surveys. This comparison was …

Go to article

A Comparison Of Diurnal Resting Sites Used By Sylvilagus Audubonii And Lepus Californicus In The Chihuahuan Desert, Robert L. Harrison Jul 2019

A Comparison Of Diurnal Resting Sites Used By Sylvilagus Audubonii And Lepus Californicus In The Chihuahuan Desert, Robert L. Harrison

Western North American Naturalist

Sylvilagus audubonii (desert cottontail) and Lepus californicus (black-tailed jackrabbit) occur in sympatry in the southwestern United States and northern Mexico. During the daytime, both species occupy shallow excavations under shrubs known as forms. Comparisons of form and shrub characteristics between the 2 species can provide insights into connections between body size, physiology, and behavior. I examined forms of the 2 species in the Chihuahuan Desert in southern New Mexico, USA, from 2014 to 2016. In response to temperature, S. audubonii varied the structure of its forms and dug burrows, whereas L. californicus did not. Sylvilagus audubonii forms were most commonly …

Go to article

Seedling Emergence Patterns Of Six Restoration Species In Soils From Two Big Sagebrush Plant Communities, Lacey Wilder, Kari E. Veblen, Eugene W. Schupp, Thomas A. Monaco Jul 2019

Seedling Emergence Patterns Of Six Restoration Species In Soils From Two Big Sagebrush Plant Communities, Lacey Wilder, Kari E. Veblen, Eugene W. Schupp, Thomas A. Monaco

Western North American Naturalist

Despite the critical need to improve degraded herbaceous understory conditions in many semiarid ecosystems, the influence of soil properties on seedling emergence of species seeded in shrubland plant communities is largely unexplored. We evaluated emergence patterns of 6 restoration species in soils from wyomingensis (i.e., Wyoming big sagebrush, Artemisia tridentata ssp. wyomingensis [Beetle & A. Young] S.L. Welsh) and vaseyana (i.e., mountain big sagebrush, A. t. ssp. vaseyana [Rydb.] Beetle) plant communities that differed in soil texture, soil organic matter content, and soil water-holding capacity. We conducted 2 separate experiments that regularly wetted soils to standardized soil water potentials (i.e., …

Go to article

Do Genetic Differences Explain The Ability Of An Alkaline Shrub To Grow In Both Uplands And Wetlands?, Carol A. Rowe, Paul G. Wolf, Robert W. Lichvar Jul 2019

Do Genetic Differences Explain The Ability Of An Alkaline Shrub To Grow In Both Uplands And Wetlands?, Carol A. Rowe, Paul G. Wolf, Robert W. Lichvar

Western North American Naturalist

The hydrophyte Allenrolfea occidentalis (S. Watson) Kuntze (iodinebush) is a halophytic shrub of the arid southwest that is listed as a facultative wetland species on the National Wetland Plant List. This rating means that the species is usually a hydrophyte but occasionally is found in uplands. We tested for genetic (ecotypic) differences between plants sampled from wetlands versus uplands. We used the technique of genotyping by sequencing to generate data from 132 plants from 30 locations representing both wetland and upland occurrences for over 1300 loci. Analyses indicated that the strongest genetic signal is from differences in geographic distribution: samples …

Go to article

Shying Away From Sex: Examining Fear Of Negative Evaluation And Body Esteem As Mediators In The Associations Between Shyness And Sexuality, Carlie Grace Palmer Jul 2019

Shying Away From Sex: Examining Fear Of Negative Evaluation And Body Esteem As Mediators In The Associations Between Shyness And Sexuality, Carlie Grace Palmer

Theses and Dissertations

Researchers have examined how shyness influences broad aspects of relationships (i.e., quality, satisfaction); however, little is known about how shyness impacts sexuality, specifically, within committed relationships. This study examined associations between shyness and sexual frequency and sexual satisfaction within committed young adult relationships. Potential explanations for these associations (i.e., fear of negative evaluation and body esteem, consecutively) were also examined. Participants included 3,670 individuals (61.6% female) ages 30-35 from the United States who were in committed dating or marital relationships. Results revealed that shyness was negatively associated with sexual frequency and satisfaction among men and women. In addition, fear of …

Go to article

Measuring Influence On Linear Dynamical Networks, Jaekob Chenina Jul 2019

Measuring Influence On Linear Dynamical Networks, Jaekob Chenina

Theses and Dissertations

Influence has been studied across many different domains including sociology, statistics, marketing, network theory, psychology, social media, politics, and web search. In each of these domains, being able to measure and rank various degrees of influence has useful applications. For example, measuring influence in web search allows internet users to discover useful content more quickly. However, many of these algorithms measure influence across networks and graphs that are mathematically static. This project explores influence measurement within the context of linear time invariant (LTI) systems. While dynamical networks do have mathematical models for quantifying influence on a node-to-node basis, to the …

Go to article

Hydrologic And Biologic Responses Of Anthropogenically Altered Lentic Springs To Restoration In The Great Basin, Leah Nicole Knighton Jul 2019

Hydrologic And Biologic Responses Of Anthropogenically Altered Lentic Springs To Restoration In The Great Basin, Leah Nicole Knighton

Theses and Dissertations

Water is a limited and highly valued resource in the semi-arid Great Basin. Surface water sources are often small and widely spaced apart, comprising only 1-3% of the surface area of the overall landscape. Despite their small size, these springs and surrounding wet meadows have a substantial effect on the surrounding environment. Springs provide drinking water, forage and cover for livestock and wildlife, habitat for diversity of plant species and a resource for human-related activities. In recent years, many of these springs have become dewatered due to diversions of groundwater for municipal water and agriculture, and climatic shifts in precipitation …

Go to article

Bioaerosols Associated With Evaporative Cooler Use In Low-Income Homes In Semi-Arid Climates, Ashlin Elaine Cowger Jul 2019

Bioaerosols Associated With Evaporative Cooler Use In Low-Income Homes In Semi-Arid Climates, Ashlin Elaine Cowger

Theses and Dissertations

Asthma is the leading chronic illness in children in the United States. Since children in the U.S. spend a majority of their time indoors there is an increased need to understand key sources of daily asthma triggers in the home. Bacterial endotoxin, dust mite allergens and β-D-glucan have been shown to be potent inducers of asthma attacks, and high levels of these allergens in homes can trigger attacks in those with asthma. We aim to better understand the risks to those with asthma that might be associated with evaporative cooler (EC) use in low-income homes. ECs are often promoted because …

Go to article

Full Issue Jul 2019

Full Issue

BYU Studies

No abstract provided.

Go to article

Of Fire, Mammals, And Rain: Mechanisms Of Plant Invasions, Tara Boyce Bishop Jul 2019

Of Fire, Mammals, And Rain: Mechanisms Of Plant Invasions, Tara Boyce Bishop

Theses and Dissertations

Biological invasions are driving environmental state changes on a global scale. Exotic plant species must be successful at passing several abiotic and biotic filters to establish and disrupt the native plant community assembly. Understanding where exotic plants are on a regional scale and being able to characterize how exotic plants are generally interacting with their environment is crucial information for exotic species management (chapter 1). In the western United States human-related activities are augmenting the spread of exotic plant species by increasing the ignitions of wildfire. Wildfire can lead to nutrient pulses through the removal of intact native communities and …

Go to article

Characterizing Novel Pathways For Regulation And Function Of Ataxin-2, Elise Spencer Melhado Jul 2019

Characterizing Novel Pathways For Regulation And Function Of Ataxin-2, Elise Spencer Melhado

Theses and Dissertations

Ataxin-2 is an RNA-binding protein that is involved in many crucial cellular processes such as R-loop regulation, mRNA stability, TOR signaling regulation, and stress granule formation. Ataxin-2 is highly conserved, found in organisms ranging from Saccharomyces cerevisiae to Caenorhabditis elegans and Homo sapiens. Recently, ataxin-2 has been linked to the neurodegenerative disease Amyotrophic Lateral Sclerosis (ALS). ALS is a fatal disease that causes loss of motor neurons. In addition to ataxin-2 interacting with known ALS risk factor proteins, research into the relationship between ataxin-2 and ALS shows that polyglutamine expansions in ataxin-2 are gain-of-function mutations that lead to overactivity of …

Go to article

3d Printed Microfluidic Devices For Bioanalysis, Michael J. Beauchamp Jul 2019

3d Printed Microfluidic Devices For Bioanalysis, Michael J. Beauchamp

Theses and Dissertations

This work presents the development of 3D printed microfluidic devices and their application to microchip analysis. Initial work was focused on the development of the printer resin as well as the development of the general rules for resolution that can be achieved with stereolithographic 3D printing. The next stage of this work involved the characterization of the printer with a variety of interior and exterior resolution features. I found that the minimum positive and negative feature sizes were about 20 μm in either case. Additionally, micropillar arrays were printed with pillar diameters as small as 16 μm. To demonstrate one …

Go to article

Personality Inventory Dsm-5: A Spanish Translation For Hispanics In The United States, Jessica Abigail Carmona Jul 2019

Personality Inventory Dsm-5: A Spanish Translation For Hispanics In The United States, Jessica Abigail Carmona

Theses and Dissertations

The Personality Inventory DSM-5 (PID-5) was created to measure personality pathology and help in the development of a dimensional conceptualization of personality disorders (Krueger, Derringer, Markon, Watson, & Skodol, 2012). It measures five maladaptive personality traits: Negative Affect, Detachment, Antagonism, Disinhibition and Psychoticism. The PID-5 has also garnered significant support for its hierarchical structure, five-factor structure across samples and translations, and its ability to predict variance in internalizing and externalizing disorders (Krueger & Markon, 2014). The current study builds on this literature by translating the PID-5 into Spanish spoken in Latin America and testing the replicability of the five-factor structure, …

Go to article

Use Of Plant Growth Regulators To Expand The Period Of Sagebrush Seed Germination And Reduce The Risk Of Restoration Failure: Laboratory Trials, Chelsea Elizabeth Keefer Jul 2019

Use Of Plant Growth Regulators To Expand The Period Of Sagebrush Seed Germination And Reduce The Risk Of Restoration Failure: Laboratory Trials, Chelsea Elizabeth Keefer

Theses and Dissertations

Seed germination during unhospitable environmental conditions can be a major barrier to direct seeding efforts in dryland systems. In the sagebrush steppe, Artemisia tridentata Nutt. ssp. wyomingensis and Artemisia arbuscula are important shrub species that are being used in restoration, but seeding success is highly sporadic due to inter-annual and intra-seasonal weather variability. Altering and expanding the period of germination, as a form of bet-hedging, may improve plant establishment. Our objective was to determine if we could expand the period of germination using plant growth regulators (PGRs) applied in a conglomerated seed coating treatment. In a laboratory study, the seed …

Go to article

Landsat Collections Reveal Long-Term Algal Bloom Hot Spots Of Utah Lake, Rachel Shanae Tate Jul 2019

Landsat Collections Reveal Long-Term Algal Bloom Hot Spots Of Utah Lake, Rachel Shanae Tate

Theses and Dissertations

Harmful algal blooms (HABs) and nuisance algal blooms (NABs) are a worldwide phenomenon with implications for human health and safety. HABs occur when algae or bacteria grow in high enough densities to harm animals and humans. A primary component of harmful algal blooms is cyanobacteria, which are aquatic, photosynthesizing microorganisms that produce toxins at high concentrations. Cyanobacterial biomass has increased worldwide in recent decades, raising concern about the future of fresh- and marine-water systems in a changing climate. Understanding the patterns and conditions of past algal blooms can provide useful insights for managing future blooms. Remote sensing can enhance our …

Go to article

Isolation, Genetic Characterization And Clinical Application Of Bacteriophages Of Pathogenic Bacterial Species, Trever Leon Thurgood Jul 2019

Isolation, Genetic Characterization And Clinical Application Of Bacteriophages Of Pathogenic Bacterial Species, Trever Leon Thurgood

Theses and Dissertations

Bacteriophages (phages) are the smallest biological entity on the planet. They provide vast amounts of valuable knowledge to biologists. Phage genomes are relatively simple compared to the organisms they infect (prokaryotes) and yet continually point to the complexity surrounding molecular- and microbiological mechanisms of life. By studying phages we can learn of the systems of gene expression, protein interaction and DNA organization. Phages are useful not only from an academic perspective, but may also have useful clinical applications. In the face of the rise of antibiotic-resistant bacterial “super pathogens”, scientists and researchers turn to phages as alternative treatments to these …

Go to article

Dna Capture Via Magnetic Beads In A Microfluidic Platformfor Rapid Detection Of Antibiotic Resistance Genes, David Hyrum Harris Jul 2019

Dna Capture Via Magnetic Beads In A Microfluidic Platformfor Rapid Detection Of Antibiotic Resistance Genes, David Hyrum Harris

Theses and Dissertations

Antibiotic resistant infections are a growing health care concern, with many cases reported annually. Infections can cause irreversible bodily damage or death if they are not diagnosed in a timely matter. To rapidly diagnose antibiotic resistance in infections, it is important to be able to capture and isolate the DNA coding for the resistance genes. This is challenging because bacteria are present in blood in minute concentrations. To enrich the DNA to detectable levels, I modified magnetic microbeads with ssDNA sequences complementary to the target DNA to capture the DNA via hybridization. I compared DNA capture efficiency in three different …

Go to article

Role Of Transient Receptor Potential Channels In Epithelial Morphogenesis In Chick Embryo, Trinity Q. Waddell Jul 2019

Role Of Transient Receptor Potential Channels In Epithelial Morphogenesis In Chick Embryo, Trinity Q. Waddell

Theses and Dissertations

Transient Receptor Potential channels (TRP) are a superfamily of cationic specific ionchannels that are regulated by various stimuli such as temperature, pH, mechanical stress, ligandsand ion concentration. The role of TRP channels in disease states such as autosomal dominantpolycystic kidney disease, cancer metastasis, and developmental defects lend credence to thebelief that they play an important part in epithelial morphogenesis events. The development ofsomites, neural tube closure and migration of neural crest cells to form things such as the faceand heart is a good developmental model for the aforementioned cellular processes. We haveshown that TRP channels can be found in the …

Go to article

Mechanism Of Positive, Non-Additive Litter Decomposition, Na Yin Jul 2019

Mechanism Of Positive, Non-Additive Litter Decomposition, Na Yin

Theses and Dissertations

Litter decomposition is a fundamental ecosystem process. It is responsible for nutrient cycling and influences carbon (C) sequestration, and soil physical and chemical properties. In nature, litter is usually heterogeneous and may not decompose the way homogeneous litter does. For example, heterogeneous litter decomposition is frequently non-additive. This makes the rate of nutrient cycling as well as fluxes of C into and out of soil C pools impossible to predict. The most frequently proposed mechanisms for positive, non-additive decomposition include the supply of limiting mineral nutrients, the supply of available C (priming), and the improvement of micro-environmental conditions. However, all …

Go to article

Sequential Survival Analysis With Deep Learning, Seth William Glazier Jul 2019

Sequential Survival Analysis With Deep Learning, Seth William Glazier

Theses and Dissertations

Survival Analysis is the collection of statistical techniques used to model the time of occurrence, i.e. survival time, of an event of interest such as death, marriage, the lifespan of a consumer product or the onset of a disease. Traditional survival analysis methods rely on assumptions that make it difficult, if not impossible to learn complex non-linear relationships between the covariates and survival time that is inherent in many real world applications. We first demonstrate that a recurrent neural network (RNN) is better suited to model problems with non-linear dependencies in synthetic time-dependent and non-time-dependent experiments.

Go to article

Isolation, Characterization, And Genomic Comparison Of Bacteriophages Of Enterobacteriales Order, Ruchira Sharma Jul 2019

Isolation, Characterization, And Genomic Comparison Of Bacteriophages Of Enterobacteriales Order, Ruchira Sharma

Theses and Dissertations

According to CDC, every year at least 2 million people are affected and 23,000 dies as a result of antibiotic resistance in U.S. It is considered one of the biggest threats to global health. More and more bacterial infections are becoming harder to treat. One such infection is fire blight, one of the most destructive disease of apple and pear trees. It is caused by bacteria Erwinia amylovora and its outbreaks have been known to destroy entire orchards in a single season. The conventional method of treatments includes use of antibiotics like streptomycin and oxytetracycline but the incidences like presence …

Go to article

The Relationship Between Vascular Endothelial Function Andpeak Exercise Blood Flow, Brady Edward Hanson Jul 2019

The Relationship Between Vascular Endothelial Function Andpeak Exercise Blood Flow, Brady Edward Hanson

Theses and Dissertations

Purpose The vascular endothelium is an influential contributor to vasodilation at rest, yet its role during peak exercise is relatively unknown. The purpose of this study is to determine if exercise leg blood flow during dynamic submaximal and maximal exercise is related to resting vascular endothelial function. Methods Nineteen subjects (aged 23 ± 0.57 yr) completed multiple assessments of vascular endothelial function including passive leg movement (PLM), rapid onset vasodilation, (ROV) and flow-mediated dilation (FMD). Peak muscle blood flow was assessed during single leg knee extension (KE) exercise. Doppler ultrasound of the femoral artery was utilized to assess muscle blood …

Go to article

Adversarial Deep Neural Networks Effectively Remove Nonlinear Batch Effects From Gene-Expression Data, Jonathan Bryan Dayton Jul 2019

Adversarial Deep Neural Networks Effectively Remove Nonlinear Batch Effects From Gene-Expression Data, Jonathan Bryan Dayton

Theses and Dissertations

Gene-expression profiling enables researchers to quantify transcription levels in cells, thus providing insight into functional mechanisms of diseases and other biological processes. However, because of the high dimensionality of these data and the sensitivity of measuring equipment, expression data often contains unwanted confounding effects that can skew analysis. For example, collecting data in multiple runs causes nontrivial differences in the data (known as batch effects), known covariates that are not of interest to the study may have strong effects, and there may be large systemic effects when integrating multiple expression datasets. Additionally, many of these confounding effects represent higher-order interactions …

Go to article

Sex And Death On The Western Emigrant Trail: The Biology Of Three American Tragedies, Melvin L. Bashore Jul 2019

Sex And Death On The Western Emigrant Trail: The Biology Of Three American Tragedies, Melvin L. Bashore

BYU Studies

Who would be more likely to survive in a wilderness setting, beset by starvation and extreme cold? Women or men? Single individuals or families? Would age make a difference? In Sex and Death on the Western Emigrant Trail, Donald Grayson looks at who died and who lived in three mid-nineteenth-century emigrant groups. An emeritus professor of anthropology at the University of Washington, Grayson began looking at patterns of death in the Donner Party, publishing his findings in 1990 and 1993. Curious if those same patterns of death were manifest in another emigrant group, Grayson began looking at the 1856 …

Go to article

Front Matter Jul 2019

Front Matter

BYU Studies

No abstract provided.

Go to article

The Effects Of Class-Wide Function-Related Intervention Teams In Two Middle School Art Classrooms, Kimberly Davis Monson Jul 2019

The Effects Of Class-Wide Function-Related Intervention Teams In Two Middle School Art Classrooms, Kimberly Davis Monson

Theses and Dissertations

Classroom management is a common challenge in middle schools. Class-wide Function-Related Intervention Teams (CW-FIT) is a multi-tiered intervention designed to decrease problem behaviors at the classroom level (Wills et al., 2010). It is comprised of evidence-based practices such as teaching classroom expectations, increasing teacher praise, and using positive reinforcement in an interdependent group contingency. CW-FIT has shown promise in a variety of school settings, but it has not been tested in middle school art classrooms. This was initial investigation examining the effects of CW-FIT using a single-subject ABAB design in two middle school art classrooms. Results indicated that class on-task …

Go to article

The Association Of Spirituality And Well-Being In South African And Ugandan Samples, Alicia Jane Doman Jul 2019

The Association Of Spirituality And Well-Being In South African And Ugandan Samples, Alicia Jane Doman

Theses and Dissertations

Literature has shown a correlation between spirituality and well-being, but this has not been thoroughly studied outside North America, with very few studies conducted in Africa. This study compared data from two sub-Saharan African nations, Uganda and South Africa, that differ markedly in terms of multiple factors that affect well-being, such as mortality rates and access to healthcare, as well as educational and personal growth opportunities. Survey data were collected using the measures of The Spiritual Involvement and Beliefs Scale and Ryff's Personal Well-Being Scale. There were four racial groups represented in the data: Black South Africans, Coloureds, White South …

Go to article

First Prev Next Last