Life Sciences Commons^™

Impedance Sensing Of Cancer Cells Directly On Sensory Bioscaffolds Of Bioceramics Nanofibers, Hanan Alismail

Graduate Theses and Dissertations

Cancer cell research has been growing for decades. In the field of cancer pathology, there is an increasing and long-unmet need to develop a new technology for low-cost, rapid, sensitive, selective, label-free (i.e. direct), simple and reliable screening, diagnosis, and monitoring of live cancer and normal cells in same shape and size from the same anatomic region. For the first time on using an impedance signal, the breast cancer and normal cells have been thus screened, diagnosed and monitored on a smart bioscaffold of entangled nanowires of bioceramics titanate grown directly on the surface of implantable Ti-metal and characterized by …

Genetic And Genomic Analyses Of Bacterial Responses To Different Stress Environments, Sakshi Rampal

Graduate Theses and Dissertations

Bacteria encounter a plethora of environmental stresses and have evolved different mechanisms to recognize and respond to various harmful conditions. Understanding and elucidating common themes as well as unique aspects of the molecular mechanisms underlying stress adaptation is important and can provide valuable strategies for applications. This study focuses on stress responses in three different bacteria, namely, Acidothermus cellulolyticus, Mycobacterium smegmatis and Escherichia coli. The thermophilic and acidophilic organism A. cellulolyticus was used as a model system to understand the effects of lignin phenolic acids on cellulolytic bacteria. Lignin phenolic acids pose a significant challenge to microbial deconstruction of lignocellulosic …

Assessing Rice Consumers’ Preferences And Willingness To Pay In Haiti, Cleeford Pavilus

Graduate Theses and Dissertations

In the last 30 years, rice has become the number one food staple in Haiti, and rice imports have outpaced domestic production to supply the country’s increasing rice demand. Policy makers support the claim that increasing local rice supply will not only reduce the dependency on imported rice but also upheave the national economy. However, there is a lack of information on Haitian consumers’ preferences for rice to aid the development of the local rice supply chain. This research aims to bridge that gap by assessing Haitian consumer preferences and willingness to pay for selected rice quality characteristics. The results …

Synthesis Of Dicamba Glucosides For The Study Of Environmental Dicamba Drift Effects On Soybeans, Holly Wallace

Graduate Theses and Dissertations

The most popular herbicide used for weed control has been glyphosate for many years in the Midwestern United States. Plants have begun to develop a resistance to glyphosate due to over use of the herbicide. This herbicide resistance has pushed farmers to turn to alternative herbicides such as dicamba and 2,4-D. Recently agrochemical companies have developed genetically modified crops that are resistant to herbicides such as dicamba. These modified crops allow farmers to spray their fields with dicamba without fear of crop damage. Farmers of non-genetically modified crops, however, suffer damage and loss of yield from herbicide drift effects of …

Study Of Three Potential Variables That May Impact The Maximum Shear Force And Shear Variation During The Growth And Transport Of Mixed Sex Broilers Grown In Commercial Poultry Houses, Mark Christie

Graduate Theses and Dissertations

Temperature conditions during the transportation to the processing facility of commercial broilers have a direct impact on the meat texture, specifically maximum shear force and shear variation of cooked breast meat. Analysis of a calendar year of flock data (N=346), reveals that the largest impact of transport conditions, specifically temperature, is on the standard deviation of the flocks range of cooked shear values. The optimal transport temperature that yields broiler breast meat with average flock minimum shear and standard deviation values is approximately 60°F. The shear values for flocks at or near 60°F are on average 1 kg less than …

The Effect Of Dehydration On Metabolism And Energy Substrate Utilization, Zachary Robert Lewis

Graduate Theses and Dissertations

The purpose of this study was to measure hormonal and metabolic markers in humans to see if simulating dehydration would emulate measures that are seen in prediabetic humans. 60 volunteers were divided into equal categories by sex and body mass index of normal or overweight. Participants completed two oral glucose tolerance tests (OGTT) after being intravenously infused with a isotonic or hypertonic saline solution for 120 minutes in a counter balanced order. All trials began with a euhydrated subject with a urine specific gravity (USG)

Vegetation Characteristics And Bird Communities Associated With Singing Painted Buntings In Northwest Arkansas, Lauren Kristina Thead

Graduate Theses and Dissertations

It has been shown that bird communities are affected by the species composition and physical structure of plant communities. Within avian communities, the bird species that are the most localized in distribution tend to be the most affected by habitat changes. My research analyzed plant and bird communities found with the Painted Bunting (Passerina ciris Linnaeus), a locally common but declining species throughout much of its range. First, I describe vegetation characteristics associated with singing male Painted Buntings in northwest Arkansas. I categorized field sites with singing male Painted Buntings as either managed for wildlife or unmanaged, based on land-use …

Weed Control And Management For Vegetable Soybeans In Arkansas, Seth Bernard Abugho

Graduate Theses and Dissertations

Vegetable soybean [Glycine max (L.) Merr.], known as edamame, needs weed management tools. Releasing locally adapted edamame soybean varieties and registering herbicides are necessary for successful production and expanding the edamame industry. This research aimed to 1) identify herbicides labeled for grain soybean for potential use on edamame; 2) evaluate differential tolerance of edamame soybean varieties to selected grain soybean herbicides; and 3) identify a feasible edamame-based crop rotation system. For objective 1, 26 herbicide treatments were tested on AVS-4002 edamame including preplant (PPL), preemergence (PRE) and postemergence (POST) herbicides labeled for grain soybean. Preplant herbicides caused 9 to 28% …

Aqueous Ozone Inactivation Of Viruses And Bacteria On Biotic And Abiotic Surfaces, Cailin Dawley

Graduate Theses and Dissertations

Produce is susceptible to contamination by foodborne pathogens. Food service establishments utilize sanitizing agents to reduce microbes on produce surfaces. The research objectives were to evaluate the efficacy of aqueous ozone 1) on the inactivation of viruses and bacteria on produce; 2) on the inactivation of viruses on stainless steel; and 3) against viruses in association with bacteria on produce surfaces. For objective 1, Boston bibb lettuce and cherry tomatoes were spot inoculated with a cocktail of viruses (murine norovirus (MNV) and MS2 bacteriophage) or bacteria (Enterobacter cloacae and Bacillus cereus) and washed for 40 min with samples taken every …

Responsiveness Of Cobb Mv × 700 Broilers To Dietary Amino Acid And Energy Density, Craig William Maynard

Graduate Theses and Dissertations

As new broiler crosses are introduced to the industry, it is of paramount importance to understand their nutritional digressions from previous and other modern broilers. In particular, amino acids (AA) and dietary energy have been identified as key drivers of live performance and carcass composition. In addition, increased nutrient density in broiler diets have been linked to an increase in breast muscle myopathies such as white striping and woody breast. Therefore, a series of trials were conducted to determine the responsiveness of live performance, carcass characteristics, and breast muscle myopathies of Cobb MV × 700 broilers to dietary AA and …

Fall Migration And Winter Habitat Use Of Northern Saw-Whet Owls (Aegolius Acadicus) In The Ozark Highlands, Mitchell L. Pruitt

Graduate Theses and Dissertations

Studying movement ecology is important not only in understanding the distribution of a species, but in understanding the magnitude of migration through certain regions, as well as explaining regional differences in demographics. The Northern Saw-whet Owl (Aegolius acadicus) is a small, migratory forest owl found throughout much of North America. Despite being captured widely during fall migration, the species’ movement ecology is poorly understood. Exploratory studies outside the saw-whet owl’s normal range have successfully captured the species during fall migration. In the Ozark Highlands ecoregion of the central United States, their status has been considered vagrant during fall and winter. …

Effect Of Macrograzers (Campostoma Spp. And Faxonius Spp.) On Periphyton In Ozark Streams With Considerations Given To Macrograzer Biomass, Phosphorus, And Season: Mensurative And Manipulative Studies, Kayla R. Sayre

Graduate Theses and Dissertations

Nutrient and benthic algal biomass relationships can guide numeric nutrient criteria development in lotic systems. However, herbivorous macrograzers may confound this relationship by reducing the slope of the positive relationship between nutrients and periphyton biomass in streams. I conducted a mensurative field study to determine if stoneroller and crayfish abundance related to algal biomass at varying nutrient concentrations and manipulated macrograzer presence with electrical exclosures in streams to examine macrograzer effects on algal biomass and understand whether these effects on periphyton varied with total phosphorus (TP) or season. Macrograzer density was quantified across a TP gradient (n=15 streams; range = …

The Evaluation Of Genetic And Phenotypic Differences Associated With Short Term Selection Of Four Different Feed Efficiency Strategies In Japanese Quail, Alex David Gilley

Graduate Theses and Dissertations

The concept of feed efficiency (FE), one unit of feed required to improve one unit of desired output, is relatively simple. However multiple outputs are desired in a commercial poultry breeding program, resulting in the need for nutrients to be partitioned in a particular manner. At the broadest level, nutrients are partitioned between production and maintenance requirements. The requirements for production and maintenance varies between birds. It is the poultry breeder’s responsibility to select individuals most aligned with the breeding objective. Irrespective of the breeding objective, various related and non-related traits influence a bird’s FE. To effectively improve FE, the …

Evaluation Of Rice Stink Bug, Oebalus Pugnax (F.), Damage And Monitoring Techniques In Rice, Oryza Sativa L., And Grain Sorghum, Sorghum Bicolor (L.), Aaron Joseph Cato

Graduate Theses and Dissertations

Rice stink bug, Oebalus pugnax (F.), is a serious pest of headed rice, Oryza sativa L. and an occasional pest of heading grain sorghum in the Mid-south. Work from this dissertation focuses on resolving gaps in and knowledge of rice stink bug sampling and management, and attempts to create a basis for rice stink bug damage assessment in future studies.

Field experiments were conducted from 2016-2018 to asses variation in sweep net sampling by observing producers, researchers, extension personnel, consultants and their workers. Large levels of variation were found in sweep lengths between observed sweepers and reliability of smaller sweep …

Importance Of Forests Outside Protected Area Networks For Large-Seeded Tree Species And Their Large-Bodied Avian Frugivores--A Study In Vazhachal Reserve Forest, India, Aditi Achyut Lele

Graduate Theses and Dissertations

Western Ghats, the mountain chain running along the west coast of India, is one of eight global hotspots of biodiversity and is particularly notable for its endemic flora and fauna. Yet only 10% of this land enjoys the protected status. Vast forested lands exist outside the protected network of national parks and wildlife sanctuaries in the form of reserve forests, community forests, and private lands. The present study sought to understand the role of such forests in the context of ecological system involving large-seeded tree species that depend on large-bodied avian frugivores for seed dispersal. I conducted a study over …

Evaluation And Characterization Of Fitness Costs In Multiple Herbicide Resistant Echinochloa In Arkansas, Teal Marie Penka

Graduate Theses and Dissertations

Echinochloa spp. are major weed problems for rice (Oryza sativa L.) on a global scale. In the southern rice belt of the U.S.A., Echinochloa colona (L.) Link (junglerice) and E. crus-galli (L.) P. Beauv (barnyardgrass) are the most troublesome weeds. These species are morphologically diverse, and its high ploidy level augurs high genetic diversity, which favors high adaptability to stress, including herbicide selection pressure. The objectives of these studies were to 1) isolate resistant (R) and sensitive (S) biotypes from eight accessions of E. colona with different resistance profiles; 2) determine the resistance levels of selected R and S biotypes …

Optimizing Methods To Determine Metabolizable Energy Values Of Feed Ingredients For Broilers, Skyler P. West

Graduate Theses and Dissertations

Determination of metabolizable energy (ME) and amino acid (AA) digestibility values of single feed indigents continues to be two of the most important aspects for successful least-cost poultry feed formulation. It would be advantageous if a common diet type could be utilized to determine both ME and AA digestibility values of feed ingredients within a single assay. Two experiments were conducted to evaluate the effect of basal diet type and excreta collection method on the ME value of single feed ingredients determined in broiler chicks using the regression method. In experiment 1, the objective was to investigate the influence of …

Development Of A Methodology For Predicting Consumer Acceptance And Preference Toward Beverages, Shilpa Shailesh Samant

Graduate Theses and Dissertations

Consumer behavior toward food/beverages is influenced by multisensory attribute perceptions as well as emotional experiences. Traditional methods of sensory testing lack the ability to capture emotional responses and as a result, measuring food/beverage-evoked emotions remains a research challenge. There were three objectives of this dissertation study. Firstly, this study aimed to develop prediction models of acceptance of and preference for basic taste solutions using sensory attribute intensities and emotional responses. Secondly, this study aimed to extend the findings of the first objective to develop prediction models of commercially-available vegetable juice products in terms of (a) acceptance and preference under blind-tasting …

Evaluation Of Soybean Maturity Group And Planting Date In A Soybean-Rice Rotation On Overall Crop Productivity, Carrie Ortel

Graduate Theses and Dissertations

Little is known about the effects of soybean (Glycine max L.) management techniques on soil-nitrogen (N) credit development and its impact on the subsequent rice (Oryza sativa L.) crop’s success. This study was conducted to determine how soybean maturity group (MG) and planting date effect overall soybean productivity and its influence on the following rice crop. Various soybean planting dates (optimum and late) and MGs (3.5, 4.7, 5.4, and 5.6) were grown and followed in rotation with a rice crop. Six rates of pre-flood fertilizer-N (0, 44, 89, 134, 179, 224 kg N ha-1) were applied to the rice crop. …

A Tale Of Two Butterflies: The Effect Of Larval Social Environment And Circadian Rhythms On Mating Behavior In Bicyclus Anynana And Heliconius Hewitsoni, Deonna Nicole Robertson

Graduate Theses and Dissertations

Two key components of mate choice research focus on: 1) who an organism mates with, which may be influenced by any number of factors from sexual ornamentation to male-male competition; and, 2) when an organism courts, be it daily, monthly, or seasonally. Both aspects are especially important for gregarious species as mistakes in either can incur high costs to overall fitness. My research focuses on using butterflies to explore kin recognition from the larval stage and its possible impacts on adult mate choice and if courtship is circadian in Heliconius hewitsoni. My first experiment concerned kin recognition. When inbred, Bicyclus …

Assessment Of Salmonella Enterica Biofilms And Expression Differences Among Serovars, Zhaohao Shi

Graduate Theses and Dissertations

Biofilms are communities of microorganisms associated by a matrix of extracellular polymers. In this state, microorganisms occupy an ecological niche distinct from their free-floating, planktonic counterparts. Also, biofilm bacteria become biologically unique as they form communities and lose motility. The acquisition of these physiological attributes enables the biofilm to persist through harsh environmental conditions, including antimicrobial induced stress and to resist sanitization efforts. Because of these features, biofilms can rapidly disseminate across numerous surfaces and as they establish, become challenging to remove. This is a particular issue for the food industry as processing plants offer favorable conditions for biofilm formation …

Revision Of The Genus Monatractides (Parasitengona, Torrenticolidae) Of The United States And Canada: New Species, Re-Descriptions, Phylogenetics, And A Key To Species, Whitney Anne Nelson

Graduate Theses and Dissertations

The full suite of known Monatractides (Parasitengona, Torrenticolidae) taxa of North America (north of Mexico) are investigated herein using integrative methods. Species hypotheses are supported with morphology, geography, and phylogenetic analysis of the barcoding region of COI for 154 individuals from over 100 localities. Relationships between species are examined with a combined analysis of COI and 28S rDNA for 55 specimens. Previously described species are examined and re-described with color images and updated information, where possible. Our results indicate the need to synonymize two species: M. californica (Marshall, 1943) is a junior synonym of M. geographica (Marshall, 1943). We describe …

Efficacy Of Natural Compounds With Novel Carrier Systems For Controlling Campylobacter Jejuni In Post-Harvest Poultry, Sandip Shrestha

Graduate Theses and Dissertations

Campylobacter jejuni, a leading cause of bacterial gastroenteritis worldwide, is strongly associated with the consumption and/or mishandling of raw contaminated poultry products. Thus, interventions aiming to reduce C. jejuni counts on poultry products could greatly reduce the incidence of human campylobacteriosis. In the first study, the efficacy of a generally recongnized as safe (GRAS) compound, carvacrol (CR; derived from oregano oil), as an antimicrobial wash treatment to reduce C. jejuni on chicken skin was evaluated. Three delivery systems of CR: suspension, emulsion and nanoemulsion were used. C. jejuni counts were reduced up to 4 log10 cfu/sample by 2% dose of …

Aiding Growers’ Decisions: Describing Arkansas Blackberry Growers’ Resources And Needs Regarding Blackberry Production, Lesley Marie Smith

Graduate Theses and Dissertations

This study was a census of blackberry growers who attended the Blackberry Growers Association informal interest meetings held throughout the state during the month of April. The purpose of this study was to describe blackberry operations in Arkansas, describe the ideal blackberry cultivar growers want to produce, describe resources they use to research production information, and describe what changes to current resources growers would like to have. Questionnaire responses regarding blackberry production of 18 blackberry growers in the state of Arkansas were analyzed. Three growers elected to not participate resulting in an 86% response rate. The researcher hopes that this …

Anti-Inflammatory Activity Of Phenolic And Volatile Compounds In Cranberries (Vaccinium Macrocarpon L), Katherine Moore

Graduate Theses and Dissertations

The primary objective of this study was to compare the anti-inflammatory effects of phenolic and volatile compounds extracted from cranberries. The Griess Reagent System assay was used to measure the in vitro anti-inflammatory capabilities of cranberry phenolic and volatile extracts on RAW 264.7 mouse macrophage cells. This study tested the anti-inflammatory capabilities of the cranberry phenolic and volatile extracts before, as a preventative treatment, and after, as a means of treating pre-existing inflammation, inducing inflammation with lipopolysaccharide (LPS). All experiments were conducted in the following manner, varying only in whether treated with the extracts before or after LPS: 1 x …

Assessing A Peer Mentor Program In An Honors College Of Agriculture, Isabel Whitehead

Graduate Theses and Dissertations

The purpose of the study was to assess mentees’ experiences in a peer mentor program in an honors college of agriculture and to determine which factors impact mentees’ ability to relate to their peer mentor based on the theory of homophily and interpersonal attraction. Colleges of agriculture are encouraged to examine which determinants impact students’ decisions to enter agri-science programs, what draws students to postsecondary agricultural programs, and to try recruiting underserved individuals into higher education to fulfill open employment opportunities for diverse, skilled, and globally competent individuals (Goeker, et al., 2015; Stripling & Ricketts, 2017). Peer mentoring is often …

Social Interactions Occurring During An Introductory College Of Agriculture Course, Brittany Renea Leek

Graduate Theses and Dissertations

With the development of the internet, today’s students no longer are confined to the resources only found in their classrooms or public libraries and have been given the ability to gain access to virtually unlimited quantities of information on the topics or events they are discussing in their class rooms and with their peers. The use of technology for communication and education is rapidly changing, but the challenges of technology-driven learning opportunities rest on questions of access and use. There is a need to determine whether students use these methods (i.e., technology based) to more prevalently communicate today. The primary …

Investigating The Potential Of Plant-Derived Antimicrobials For Controlling Campylobacter Jejuni In Poultry And Poultry Products, Basanta Raj Wagle

Graduate Theses and Dissertations

Campylobacter jejuni infection in humans is strongly associated with the handling and consumption of contaminated poultry products. Interventions reducing C. jejuni contamination in poultry would reduce the risk of subsequent human infections. In the first study, the efficacy of a Generally Recognized as Safe (GRAS) compound, eugenol (EG; derived from cloves), as an antimicrobial dip treatment to reduce C. jejuni in postharvest poultry was evaluated. The antimicrobial efficacy of EG was studied in suspension, emulsion and nanoemulsion delivery systems. EG suspension reduced C. jejuni counts with the greatest reduction of >2.0 Log CFU/sample for the 2% dose of EG (P

Determining The Effect Of Locally Delivered Bioactive Modulators On Macrophage Activation At The Implantation Site Of Different Biomaterials In Rats, Kamel Alkhatib

Graduate Theses and Dissertations

Altering the foreign body reaction by targeting macrophages has been of interest in the biomaterials field to improve the integration of longevity of implanted biomedical devices. The objective of this dissertation was to study the effect of locally delivered bioactive modulators on macrophage activation at the implantation site of different biomaterials in rats. Iloprost, a prostacyclin analog, was tested for its ability to direct macrophages to their pro-wound healing phenotype after the implantation of microdialysis probe in the subcutaneous space of male Sprague Dawley rats. This study showed that iloprost can shift macrophage activation states in vivo to the pro-wound …

The Effects Of Consuming Eggs On The Physical And Cognitive Development Of Food-Insecure Haitian Children, Monica Elaine Stewart

Graduate Theses and Dissertations

Within Latin America and the Caribbean, severe food insecurity is highest in Haiti. Fifty-five percent of the population lives below the poverty line with approximately 50% of the population undernourished. Given the typical diet in the developing world is primarily plant-based, the two studies presented in this thesis examine how eggs, a locally available animal protein, impact physical growth, cognitive development, and motor skills of food-insecure children from a single orphanage in Leogane, Haiti when added to the diet.

In the first study, growth parameters in children ages 3-8 years old were measured at baseline, six months, and one year. …