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

Life Sciences Commons

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

PDF

2013

University of Arkansas, Fayetteville

Discipline
Keyword
Publication
Publication Type

Articles 1 - 30 of 159

Full-Text Articles in Life Sciences

Arkansas Soybean Performance Tests 2013, R. D. Bond, D. G. Dombek, J. A. Still, R. M. Pryor Dec 2013

Arkansas Soybean Performance Tests 2013, R. D. Bond, D. G. Dombek, J. A. Still, R. M. Pryor

Research Series

Soybean variety and strain performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture Arkansas Crop Variety Improvement Program. The tests provide information to companies developing varieties and/or marketing seed within the State, and aid the Arkansas Cooperative Extension Service in formulating variety recommendations for soybean producers.


Arkansas Animal Science Department Report 2013, David L. Kreider, Paul Beck Dec 2013

Arkansas Animal Science Department Report 2013, David L. Kreider, Paul Beck

Research Series

No abstract provided.


Relationships Between Landscape Factors And Crayfish Density And The Interacting Effects Of Grazing And Increased Sedimentation On Algal Biomass, Katheryn Haley Rose Dec 2013

Relationships Between Landscape Factors And Crayfish Density And The Interacting Effects Of Grazing And Increased Sedimentation On Algal Biomass, Katheryn Haley Rose

Theses and Dissertations

In recent years in the United States there has been a rapid expansion in anthropogenic sources of sediment in streams including construction, agriculture, and drilling for natural gas. Potential effects land disturbance associated with activities from natural gas development on aquatic biota in surrounding streams have not yet been well documented. An increase in inorganic sediment in streams can be detrimental to organisms through a variety of mechanisms including alteration of dominant substrate type, higher turbidity resulting in lower visibility, and burial of food resources such as algae and detritus. Increasing sedimentation in stream environments through anthropogenic disturbance is a ...


Molecular And Biochemical Mechanisms Of Pathogenesis In The Maize Foliar Pathogen Cercospora Zeae-Maydis, Winfred-Peck Dorleku Dec 2013

Molecular And Biochemical Mechanisms Of Pathogenesis In The Maize Foliar Pathogen Cercospora Zeae-Maydis, Winfred-Peck Dorleku

Theses and Dissertations

GLS is a serious foliar disease of maize, a major staple crop grown commercially in the USA for both human and animal feed production, and increasingly, for ethanol production. The disease is caused by two Cercospora species, C. zeae-maydis and C. zeina, both of which infect maize in the USA and in other parts of the world, with yield losses potentially greater than 50%, depending on local conditions. In culture, C. zeae-maydis produces a phytotoxic, host non-specific perylenequinone, cercosporin, and abscisic acid (ABA), for which there is no known pathological or physiological function in the fungus. Experimental evidence indicates that ...


Effect Of Modified Starch On Bake-Only Chicken Nuggets, Sarah Purcell Dec 2013

Effect Of Modified Starch On Bake-Only Chicken Nuggets, Sarah Purcell

Theses and Dissertations

The food industry has become increasingly focused on healthier items. Fried foods especially are actively pursuing non-fried alternatives to attract health conscience consumers. This study investigated the bake-only chicken nugget formulation in attempts to provide characteristics of fried items. Starch was hydrolyzed by amyloglucosidase to create a porous structure that had the ability to absorb oil. Oil was plated into the enzyme-treated starch and blended into nugget formulation, and the coated nuggets were steam-baked until fully cooked. The enzyme-treated starches showed a decrease in gelatinization range and pasting viscosities for all starch types. The addition of oil-plated enzyme modified starch ...


Effects Of Rain And Simulated Rain On Deoxynivalenol Levels In Grain And Chaff Of Winter Wheat With Fusarium Head Blight, Manoj Kumar Pun Dec 2013

Effects Of Rain And Simulated Rain On Deoxynivalenol Levels In Grain And Chaff Of Winter Wheat With Fusarium Head Blight, Manoj Kumar Pun

Theses and Dissertations

Wheat grain affected by Fusarium head blight (FHB) contains the mycotoxin deoxynivalenol (DON) that is harmful to humans and animals. Reducing the amount of DON in grain is the goal of management practices for FHB so it is important to understand the factors affecting DON in grain. Some studies on the effects of late-season moisture found increases in DON while others found decreases due to leaching. The objectives of this study were to determine effects of late-season rain and misting on DON concentration in wheat spike tissues and to quantify the amount of DON leached from spikes. Field experiments were ...


Phenotypic, Physiological And Growth Interactions Among Salmonella Serovars, Juliany Rivera Calo Dec 2013

Phenotypic, Physiological And Growth Interactions Among Salmonella Serovars, Juliany Rivera Calo

Theses and Dissertations

This thesis consists of four research parts: a literature review that covers Salmonella spp., one of the more prominent foodborne pathogens that represents a major risk to humans (chapter 1). Understanding the growth of Salmonella serovars and strains is an important basis for more in depth research. In this case we studied a) the aerobic and anaerobic growth responses of multiple strains from six different serovars, b) how the spent media from different serovars, more importantly S. Heidelberg, affect the growth of S. Typhimurium, and c) determined whether or not two different serovars undergo competitive interactions when they were grown ...


Effect Of Functional Starch In Brown Rice And Grain Sorghum On Plasma Glucose And Insulin Responses In Humans, Nicole Marie Poquette Dec 2013

Effect Of Functional Starch In Brown Rice And Grain Sorghum On Plasma Glucose And Insulin Responses In Humans, Nicole Marie Poquette

Theses and Dissertations

Diabetes and obesity are chronic illnesses increasing at dramatic rates in the U.S. and around the world. Research has looked to prevent or control diabetes and obesity through functional ingredients such as healthy-dietary carbohydrates to control blood glucose levels. Starch is a principle carbohydrate, which influences blood glucose levels, and measuring starch digestibility fractions can help predict the glucose response in the body. The objectives of this study were to investigate the functional starch content of parboiled brown rice flour and grain sorghum flour, and measure the effects on postprandial plasma glucose and insulin levels of 14 and 10 ...


The Effects Of Salinity On Pythium Disease Of Rice And Soybean, Terea Jeanette Stetina Dec 2013

The Effects Of Salinity On Pythium Disease Of Rice And Soybean, Terea Jeanette Stetina

Theses and Dissertations

Increasing salinity is an important factor limiting agricultural productivity worldwide. In addition to direct effects on growth and yield, diseases also may be affected. This study characterized the effects of soil salinity on seedling disease of soybean and rice caused by Pythium spp. Controlled environment experiments on soybean used two cultivars which differed in chloride tolerance and soil treated with a CaCl2 solution to create a range of electrical conductivity (EC) levels. For soybean, soil was either not infested or infested with Pythium sylvaticum or P. aphanidermatum (pathogenic to soybean), or P. oligandrum (not pathogenic to soybean). Twenty-one days ...


Effect Of Electrostatic Spraying Of Food-Grade Organic And Inorganic Acids, And Grape Seed Extract On Salmonella Typhimurium And Escherichia Coli O157:H7 On Spinach And Iceberg Lettuce, Vijayalakshmi Ganesh Dec 2013

Effect Of Electrostatic Spraying Of Food-Grade Organic And Inorganic Acids, And Grape Seed Extract On Salmonella Typhimurium And Escherichia Coli O157:H7 On Spinach And Iceberg Lettuce, Vijayalakshmi Ganesh

Theses and Dissertations

The safety of fresh produce is often challenged by the sporadic incidences of outbreaks owing to Salmonella Typhimurium (S.T.) and Escherichia coli O157:H7 (E.c.). Washing and current disinfection strategies do not completely decontaminate leafy greens such as spinach and iceberg lettuce. Therefore, more effective treatments are essential to ensure the microbial safety of the produce at the selling point. Here, a multiple hurdle approach was applied: (1) Natural antimicrobials - organic acids (malic, lactic and tartaric acids; MA, LA, TA, respectively) and plant extract (grape seed extract, GSE) and (2) Application method - Electrostatic spraying, was examined as a ...


Ecological Importance Of Ectomycorrhizal Linkages In The Ozark Mountains And The Fernow Experimental Forests, Shelly Kendra Bursick Dec 2013

Ecological Importance Of Ectomycorrhizal Linkages In The Ozark Mountains And The Fernow Experimental Forests, Shelly Kendra Bursick

Theses and Dissertations

Underground stem-to-stem linkages involving ectomycorrhizal (ECM) fungi are probably important in forest ecosystems, since these linkages could assist in the survival of established trees as well as increasing the growth and development of seedlings and saplings. This study compared forest communities of the Ozark Mountains of northwest Arkansas and the Fernow Experimental Forest in West Virginia by examining species richness, diversity, relative abundance, and the potential for stems to exhibit spatial distribution and clustering patterns that reflected the existence of linkages by ECM fungi. Data on forest communities in the Ozarks were obtained from eight plot locations in Devil's ...


Electrostatic Spray Application Of Food-Grade Organic Acids And Plant Extracts To Decrease Escherichia Coli O157:H7 And Salmonella Typhimurium On Select Produce, Leighanna Maeree Massey Dec 2013

Electrostatic Spray Application Of Food-Grade Organic Acids And Plant Extracts To Decrease Escherichia Coli O157:H7 And Salmonella Typhimurium On Select Produce, Leighanna Maeree Massey

Theses and Dissertations

Both consumers and suppliers have been negatively affected by an increase in foodborne pathogens contaminating fruits. Consequently, there is a need for the development of more efficient antimicrobials and application techniques to decrease contamination. Natural preservatives such as organic acids and plant extracts have demonstrated promising results in decontaminating produce. In addition, the effectiveness of such preservatives may be enhanced by the use of an electrostatic sprayer. The objective of this research was to determine the combinations and concentrations of organic acids and plant extract that were able to reduce Salmonella Typhimurium (ST) and Escherichia coli O157:H7 (EC) inoculated ...


The Development Of A Traumatic Brain Injury Bioreactor, Zachery Heller Dec 2013

The Development Of A Traumatic Brain Injury Bioreactor, Zachery Heller

Theses and Dissertations

Approximately 1.7 million Americans experience a traumatic brain injury (TBI) each year. Concussive injuries are a subset of TBI in which blows to the head cause the brain to collide against the interior of the skull. Damage to the neurons, supporting cells, and surrounding extra cellular matrix resulting from these collisions can lead to permanent physical, cognitive, and psychological impairment. We believe the prevalence and clinical significance of concussive injures warrants research investment. To study brain injury following TBI, in vivo models have been the gold standard for TBI experiments. Although a valuable research alternative, animals are expensive, raise ...


Development Of Novel Antifungal Peptides Based On A Natural Model Of Histatin-5 Peptide, Duy Tu Nguyen Dec 2013

Development Of Novel Antifungal Peptides Based On A Natural Model Of Histatin-5 Peptide, Duy Tu Nguyen

Theses and Dissertations

Our research group is working toward the development of novel antifungal peptides based on a natural model of peptide histatin-5. Histatin-5 is found in human saliva and known to protect our body against oral infections by Candida species. Candidiasis, or an infection caused by Candida species, is considered one of the most medically important fungal infections worldwide. Blood stream infections caused by Candida species are the fourth leading cause of hospital-acquired fungal infections that is associated with high mortality rates and high costs of treatment. This study investigated the modes of action of histatin-5 with the use of one 16-mer ...


Northwest Arkansas Consumer Perceptions Of Poultry Production, Stuart Estes Dec 2013

Northwest Arkansas Consumer Perceptions Of Poultry Production, Stuart Estes

Agricultural Education, Communications and Technology Undergraduate Honors Theses

Poultry production holds an important place in Arkansas economically and as a food source. The importance of poultry production ultimately hinges on the demands of the consumers and the perceptions that drive their purchases. With this in mind, this study surveyed consumers to assess their perceptions of poultry production in Arkansas. The instrument used to survey consumers was created by the researcher and an expert committee at the University of Arkansas. Consumers were interviewed through direct communication at grocery stores in northwest Arkansas. Data gathered from the study were analyzed for descriptive and correlational statistics. Data showed that consumers were ...


A Comparison Of Milled Rice Fissuring Kinetics Of Hybrid And Pureline Cultivars, Semehar Haile Tesfaye Dec 2013

A Comparison Of Milled Rice Fissuring Kinetics Of Hybrid And Pureline Cultivars, Semehar Haile Tesfaye

Theses and Dissertations

Over the past decade, the use of hybrid rice cultivars has greatly increased, and this has led to questions about the processing behavior of hybrid cultivars. This study compares the milled rice fissuring kinetics of hybrid and pureline cultivars. Also, this study elucidates the effects of kernel type (long-grain vs. medium-grain rice cultivars), surface lipid content (SLC), and kernel thickness on fissuring rates.

Three hybrid (CL XL745, CL XL729 and XL753) and five pureline (Wells, CL151, Cheniere, Jupiter and CL261) cultivar lots were procured. Jupiter and CL261 are medium-grain cultivars, whereas the rest are long-grain cultivars. Two experiments were conducted ...


The Development Of An In Vivo Microdialysis Collection Method Of Cytokines From Brain Tissue, Anthony W. Herbaugh Dec 2013

The Development Of An In Vivo Microdialysis Collection Method Of Cytokines From Brain Tissue, Anthony W. Herbaugh

Theses and Dissertations

In this thesis, different methods to improve the microdialysis collection procedure for cytokines from brain tissue are presented. The first method was based on stopped flow and results indicating that no significant difference in relative recovery between stopped flow and continuous flow are shown. The second method is an antibody bead-based enhancement method. With the antibody bead-based method, a 3.5 fold increase in the collected concentrations of Chemokine (C-C motif) Ligand 2 (CCL2) were observed. However, there was no significant increase in the in vivo collection efficiency of Interleukin-6 (IL-6) using the antibody enhancement. Finally the development of an ...


Greater Sage-Grouse (Centrocercus Urophasianus) Habitat Selection In Northwestern Wyoming And Stable Isotope Analysis Of Fecal Material, Andrea Renee Green Dec 2013

Greater Sage-Grouse (Centrocercus Urophasianus) Habitat Selection In Northwestern Wyoming And Stable Isotope Analysis Of Fecal Material, Andrea Renee Green

Theses and Dissertations

Dramatic range-wide declines in Greater Sage-Grouse populations have prompted efforts to determine habitat characteristics that are selected by sage-grouse for foraging, nesting and brood-rearing areas in an effort to conserve this species. Managers at Heart Mountain and Y U Bench in northwestern Wyoming expressed the need to quantify various habitat characteristics and to determine key use areas at both study sites. Data were collected on a variety of habitat variables in spots selected by grouse for foraging, nesting, and brood-rearing activities. These variables were compared to the same variables measured at random points at both study sites. Significant differences existed ...


Identification Of Biomarkers Associated With Ascites Incidence In Broilers, Kaylee Rowland Dec 2013

Identification Of Biomarkers Associated With Ascites Incidence In Broilers, Kaylee Rowland

Theses and Dissertations

Poultry is key in genetic research due to breeding feasibility, relatively short generation interval, and distinct phenotypes. It is estimated that 8% of broiler deaths annually can be attributed to ascites, an economically important disease that has been challenging the industry for the past 2 decades. Genetically selected ascites resistant (RES) and susceptible (SUS) chicken lines have been established and maintained by the University of Arkansas, Fayetteville. Intensive research efforts have been made to reveal physiological and biochemical characteristics for the incidence of ascites. Since the whole genome of the major ancestral chicken, the Red Jungle Fowl, has been sequenced ...


Physical And Biochemical Factors Affecting Breast Fillet Tenderness In Broilers Reared For Divergent Market Demands, Valerie Belle Brewer Dec 2013

Physical And Biochemical Factors Affecting Breast Fillet Tenderness In Broilers Reared For Divergent Market Demands, Valerie Belle Brewer

Theses and Dissertations

Market trends have dictated that broilers be reared for divergent market demands for decades. Also, broiler genetic strains have been adapted to meet market demands which include: genetic selection for improved breast meat, the practice of growing birds to older ages and greater market weights to meet demands, and decreasing postmortem (PM) aging time to improve processing efficiency and fillet yield. These production practices can also affect product quality, specifically boneless breast fillet tenderness and water-holding capacity. To address these factors, a series of experiments were conducted to determine the effect of strain and slaughter age on meat quality parameters ...


Development Of Novel Subunit Vaccine Against H5n1 Influenza, Lu Zhang Dec 2013

Development Of Novel Subunit Vaccine Against H5n1 Influenza, Lu Zhang

Theses and Dissertations

Influenza is a common infectious disease resulting from a frequently mutated RNA virus. Vaccination is currently the most effective method to prevent people from seasonal or pandemic influenza. The production of traditional egg-based influenza vaccine is time-consuming and provides limited effect against new strains. Therefore, it is necessary to develop a rapid method to produce influenza vaccines. We proposed a novel influenza vaccine based on the E.coli expression system. Hemagglutinin (HA) is the major target surface protein of influenza virus for vaccine development. In this study, we sub-cloned the HAs encoding gene into an E. coli expression vector; the ...


The Role Of Histone H3 And H4 In Centromere Function And Genome Integrity, Payel Chaudhuri Dec 2013

The Role Of Histone H3 And H4 In Centromere Function And Genome Integrity, Payel Chaudhuri

Theses and Dissertations

Histone H2A plays an important role in chromosomal segregation among parent and daughter cells during mitosis. While it is established that this histone is important in maintaining chromosome number in cell, further work is carried out to explore the role of other histones like H3 and H4 for similar effects. A systematic study is initiated by screening a library based on mutation of different amino acid residues in these histones. This detailed screening identified specific regions within H3 and H4, which are critically important for centromeric function. These histones residing near the DNA entry/exit region of nucleosome effects the ...


The Color And Consistency Of Steaks And Ground Beef Produced From Mature Bulls, Jace Joseph Hollenbeck Dec 2013

The Color And Consistency Of Steaks And Ground Beef Produced From Mature Bulls, Jace Joseph Hollenbeck

Theses and Dissertations

Two experiments were conducted to compare the color and cooked attributes of steaks and ground beef produced from mature bulls. Beef from mature bulls was used to test the effects of lactic acid (LA) enhancement solution pH (2.5, 3.0, or 3.5; B25, B30, B35, respectively) on fresh (5 d of display) and cooked color and tenderness of strip loin steaks (Exp. 1) and the effect of high pH trim on precooked ground beef patties (Exp. 2). In experiment 1, mature bull strip steaks were enhanced to 111% with a LA, sodium bicarbonate, and tap water solution, in ...


In Vitro Analysis Of Short Chain Fatty Acids And Human Fecal Microbiota Stimulated By Pectin Sources, Byungjick Min Dec 2013

In Vitro Analysis Of Short Chain Fatty Acids And Human Fecal Microbiota Stimulated By Pectin Sources, Byungjick Min

Theses and Dissertations

As interest increases for colonic health, various studies have been conducted to investigate functional ingredients for host health and prevention of chronic disease in humans such as colon cancer and Type 2 diabetes. In particular dietary fiber has been reported to have beneficial effects on colonic health. More recently, dietary fiber has been categorized based on its characteristics and numerous studies have been conducted to determine correlations with chronic diseases. Pectin is a naturally occurring biopolymer that has been used in various applications for purposes of pharmaceutical and biotechnology. Pectin is a soluble dietary fiber and can be entirely fermented ...


Evaluation Of Shake Weight Protocol In Senior Populations, Isaac F. Cook Dec 2013

Evaluation Of Shake Weight Protocol In Senior Populations, Isaac F. Cook

Theses and Dissertations

The Shake Weight® (SW®) is designed to improve muscular fitness in a quick and inexpensive way. This study aimed to determine if the SW® was an effective tool at improving muscular fitness, body composition, and bone mineral density (BMD) in post-menopausal women. Participants were 17 healthy, post-menopausal women from aMidwestern University and divided into two training (SW® and HIT) interventions that lasted 10 weeks. HIT participants performed three sets of 8 repetitions at 80% of their estimated 1RM for the chest press, leg press, lat pulldown, and seated row. SW® participants performed the exercises prescribed by the SW® manufacturer. Changes ...


Preservice Candidates' Rating Of Effectiveness In Agricultural Education Through Structured Communication With Cooperating Teachers, Christopher Lee Hunt Dec 2013

Preservice Candidates' Rating Of Effectiveness In Agricultural Education Through Structured Communication With Cooperating Teachers, Christopher Lee Hunt

Theses and Dissertations

The relationship between cooperating teacher and student has been found as one of the key elements that affect the overall teaching efficacy of student teachers and their decision to enter the teaching field after graduation (Edgar, 2007; Edgar, Roberts, & Murphy, 2011,2008; Kasperbauer et al., 2007a; Roberts, Greiman, Murphy, Ricketts, Harlin, & Briers 2009; Roberts, Harlin, & Briers, 2007, Roberts, Harlin, & Ricketts, 2006; Roberts Mowen, Edgar, Harlin & Briers, 2007, Stripling, Ricketts, Roberts & Harlin, 2008; Wolf, 2011; Wolf et al., 2010). Therefore, determining impacts towards teaching efficacy during the student teaching experience could play a vital role in future teachers' success. The purpose of this study was to assess teaching efficacy and the relationship between student teacher and cooperating teacher through ...


Biochemical And Biophysical Studies Of Novel Features Of Ras-Related Protein Interactions, Kyla Marie Morinini Morris Dec 2013

Biochemical And Biophysical Studies Of Novel Features Of Ras-Related Protein Interactions, Kyla Marie Morinini Morris

Theses and Dissertations

The Ras superfamily of G-proteins are of great research interest for structure-function relationships among proteins as they act as molecular switches in the regulation of various biochemical reactions in the cell. They are regulated by protein-protein interactions targeted to the highly flexible switch regions. Mutations in G-proteins or their effectors may cause alterations in structure and/or function that can lead to overactivity.

The Ras-related protein Cell division cycle 42 (Cdc42) is important in regulating cell-signaling processes. The T35A mutation in Cdc42 leads to a decrease in flexibility of the Switch I region responsible for effector binding. The kinetics of ...


Bacterially-Mediated Formation Of Rock Coatings In Kärkevagge, Swedish Lapland: A Mineralogical And Micro-Environmental Analog For Mars, Cassandra L. Marnocha Dec 2013

Bacterially-Mediated Formation Of Rock Coatings In Kärkevagge, Swedish Lapland: A Mineralogical And Micro-Environmental Analog For Mars, Cassandra L. Marnocha

Theses and Dissertations

The search for past or present life on Mars is, for now, limited to surface environments. An often neglected surface environment that could have served as an abode for life and could presently preserve evidence of that life is that of rock coatings. Rock coatings are mineral accretions on rock surfaces. On Earth, they are widespread and occur with considerable chemical diversity. There is growing evidence for a biotic role in their formation on Earth, particularly with respect to rock varnish. As a result, rock varnish has become a target of astrobiological interest on Mars, where varnish-like coatings have been ...


Sugar And Rice Trade Between The United States And Cuba Trade Potential And Welfare Analysis, Fabian Bloechl Dec 2013

Sugar And Rice Trade Between The United States And Cuba Trade Potential And Welfare Analysis, Fabian Bloechl

Theses and Dissertations

After the resignation of President Fidel Castro and forty-five years of the U.S.-trade embargo, the political environment between Cuba and the United States is expected to change. With the Trade Sanction Reform and Export Enhancement Act in 2000, trade sanctions were eased for a while. Future trade between both countries would increase the welfare in both countries. This Thesis has the approach to look at the impacts on the commodities of rice and sugar, and the trade sanctions between the United States and Cuba.

Cuba is a net importer of its food supply; therefore, agriculture and food trade ...


Long-Term Residue And Water Management Effects On Soil Respiration And Soil Aggregate Stability In A Wheat-Soybean, Double-Crop System In Eastern Arkansas, Sharon Faye Smith Dec 2013

Long-Term Residue And Water Management Effects On Soil Respiration And Soil Aggregate Stability In A Wheat-Soybean, Double-Crop System In Eastern Arkansas, Sharon Faye Smith

Theses and Dissertations

Sustainability in agriculture is paramount to assuring continued production from our most naturally fertile soils. Storing carbon (C) in soil as organic matter through sustainable agricultural management practices can both remove atmospheric C and improve soil quality. The objective of this study was to evaluate the long-term effects of water management (irrigation and dryland), residue management [burn and no-burn, conventional (CT) and no-tillage (NT)] and residue/fertility level (high and low) on soil respiration and aggregate stability in a wheat- (Triticum aestivum L.) soybean [Glycine max (L.) Merr.], double-crop system in a silt-loam soil (Aquic Fraglossudalf) in the Mississippi River ...