Life Sciences Commons^™

Growth Differentiation Factor 5 Is A Paracrine Regulator Of Sarcopenic Obesity, Landen W. Saling

Graduate Theses and Dissertations

Sarcopenic obesity attributes to skeletal muscle loss more than sarcopenia and obesity alone. Individuals with SO suffer from the comorbidity of excess body fat and concurrent muscle mass loss due to aging. Growth differentiation factors (Gdfs) have never been recognized as playing a role in skeletal muscle maintenance in those with SO. Specifically, Gdf5, has been recognized as playing a part in Bone Morphogenic Protein signaling to activate protein synthesis and deactivate protein degradation via SMAD 1/5/8 and SMAD 4 complex. Using RNA sequencing, Gdf5 was identified as being significantly upregulated in SO mice. Purpose: To determine the cellular role …

Evaluation Of The Effect Of A Lippia Organoides Essential Oil Extract On Clostridium Perfringens Proliferation In Vitro And Necrotic Enteritis In Broiler Chickens, Makenly E. Coles

Graduate Theses and Dissertations

The purpose of the present research was to assess the effects of essential oils derived from the plant Lippia organoides on performance parameters, intestinal integrity, and necrotic enteritis (NE) in broiler chickens. To do this, a previously established challenge model for NE was utilized which included challenging with Salmonella Typhimurium on day 0, Eimeria maxima on day 18, and Clostridium perfringens on days 22 and 23. Treatment groups included a 1) non-challenged, negative control, 2) challenged control, and 3) challenged, Lippia origanoides (37ppm in the diet). Group 1 (negative control) had significantly (P < 0.05) higher body weight gain from d8-25 and d0-25 compared to both challenged groups. Feed intake was significantly different for all three groups (P < 0.05) at 8-25 days and 0-25 days with group 1 having the highest feed intake for both time periods. Total mortality was greater in the positive control when compared to both the negative and treatment groups. NE lesion scores were significantly different between all groups with the positive control having the highest mean lesion scores and the negative control having a mean lesion score of 0. The positive control group had the highest FITC-d amounts detected in the sera, being statistically higher than both the treatment group and negative group which were both statistically different from each other. At the present inclusion rate for the essential oil (37 ppm), there was an overall reduction in the negative impact from the NE infection. Further studies should be conducted to reach more significant conclusions.

Essential Amino Acid (Eaa) Regulation Of Skeletal Muscle Protein Turnover With Age, Mary Komp

Graduate Theses and Dissertations

Skeletal muscle (SM) is vital for both long term health and quality of life. Recent research suggests an increase in catabolic signals with age triggers pathologic conditions, such as sarcopenia. Although results from in vitro studies model how EAA can regulate muscle protein synthesis (MPS), the relevance of these models to muscle protein breakdown (MPB) and the presence of physiological EAA concentrations remains to be established. Therefore, the objective of this study was to determine the effects of a low, normal, and supra physiological dose of EAA (0.2, 1.0, and 3.0 x EAA) in a young (passages 2-10) and aging …

A Mixed Methods Approach To Context Specific Curriculum Design For Very Small And Small Strawberry Growers In The Southeastern United States, Thomas A. Yeargin

Graduate Theses and Dissertations

Outbreaks of foodborne illness due to fresh produce are a continued threat to both the publichealth and the economy in the United States. Though there are many factors which influence the perpetuation of foodborne pathogens, the inability of the food industry to curtail this issue indicates systemic failure of interventions aimed at improving food safety practices. In this dissertation, we detail the efforts made over the past few decades to provide training to food producers and food handlers as well as recommendations that have been made for improvement based on these studies. By borrowing from more advanced fields of study …

Breeding Soybean [Glycine Max (L) Merr.] Under Reduced Irrigation, Francia Seconde Ravelombola

Graduate Theses and Dissertations

Soybean [Glycine max (L) Merr.], a legume species native to East Asia in the Fabaceae family, ranks among the most important food crops in the world. It is widely grown and known for its high protein and oil concentration. Soybean is valuable because its seeds have multiple applications in food, feed, pharmaceutical, and industrial enterprises. Even though seed yield is the most important trait, breeders have recently given a significant attention to quality traits, such as high protein or modified oil concentration. Soybean seed protein inheritance has been extensively studied; however, genetics of high-protein ‘BARC-7’ soybean are still unknown.On the …

The Effects Of Metronomic And Maximum-Tolerated Dose Chemotherapy In Colorectal Cancer Angiogenesis: A Combined Approach Using Endoscopic Diffuse Reflectance Spectroscopy And Mrna Expression, Ariel Isaac Mundo Ortiz

Graduate Theses and Dissertations

Colorectal cancer (CRC) continues to be one of the most incident and deadliest types of cancer worldwide. Chemotherapy has proven effective to reduce tumor burden for CRC patients, but there are several disadvantages associated with the use of mainstay maximtolerated dose (MTD) chemotherapeutic strategies. Metronomic chemotherapy (MET) has been developed as an alternative that addresses the shortcomings of maximum-tolerated dose chemotherapy but so far its effectiveness as a neoadjuvant strategy for CRC has not been explored.

This dissertation uses a combined optics and molecular biology approach (using diffuse reflectance spectroscopy and mRNA expression) to study the changes in angiogenesis and …

Studies Of Avian Nasal Mites (Acari: Rhinonyssidae And Ereynetidae) And Their Interaction With The Brood Parasite Brown-Headed Cowbird (Molothrus Ater: Icteridae) And Phylogenetic Inferences Of The Genus Ptilonyssus (Rhinonyssidae) On Different Passerine Hosts Associated To Three States In The Us, Alexis D. Hilario Perez

Graduate Theses and Dissertations

Nasal mites are endoparasites that spend their entire life cycle inside the nasal cavities and respiratory passages of birds. The Brown-Headed cowbird (Molothrus ater) (BHCO) is an icterid bird that uses brood parasitism as a reproductive strategy in which it lays an egg in the nest of a different bird species and allows the host to raise its young. Interestingly, nasal mites reported from cowbirds represent the same species found infesting other icterids and other common host groups. In the first study, I examined how diversity and host prevalence might change in a large sample size of BHCO associated with …

Examining Risks To Honey Bee Pollinators Foraging In Agricultural Landscapes, Jon Zawislak

Graduate Theses and Dissertations

Bee pollinators provide essential ecological services to wild plant communities, and addtremendous economic value to agriculture by improving both the quality and quantity of crop yield. Beekeepers are often contracted by growers to provide colonies of honey bees for pollination of high-value produce (fruits, vegetables and nuts). Many of the major commodity crops produced in the central and mid-southern United States are wind-pollinated (rice, corn, grain sorghum, wheat), or are sufficiently self-fertile (soybeans, cotton), and so do not require bee pollination in order to produce yield. Beekeepers still rely on these agricultural landscapes to support honey bee colonies when not …

Habitat Assessment Of Ozark Glades Using Selected Epigeal Predatory Arthropods, Austin Key Jones

Graduate Theses and Dissertations

Epigeal predatory arthropods were collected with pitfall-style traps in nine sandstone glades of varying ecological stages, and management histories, in the Ozarks of Northern Arkansas over three years. These sites were categorized into three Site Types; Intact, high quality glades; Degraded, forest-encroached glades, and Restored glades which had received woody vegetation removal and burning. Collections of ground spiders (Gnaphosidae), predatory ground beetles (Carabidae), and the sole species of scorpion present in the Ozarks, Centruroides vittatus, were reported on as well as the applicability of arthropod collection methods for glade habitat assessment. Habitat characteristics were recorded for each site and analyzed …

Field Evaluation Of Struvite As A Phosphorus Source, Niyi Sunday Omidire

Graduate Theses and Dissertations

Phosphorus (P) is an element that is crucial in many biological processes in all forms of life and is not substitutable. Excess P in wastewaters leading to the degradation of receiving waters or eutrophication once released is a major environmental concern. Removal of excess P from wastewater as the mineral struvite (MgNH4PO4·6H2O) could be a promising solution to reduce P discharge into receiving waters and can potentially provide a valuable fertilizer-P source for agricultural production. The objectives of this project were to evaluate the effects of: 1) chemically precipitated struvite (CPST), compared to triple superphosphate (TSP) and an unamended control …

Canine Microwear In Relation To Diet In Sumatran Primates And African Great Apes, Putu Pujiantari

Graduate Theses and Dissertations

This thesis considers canine microwear in relation to diet in five Sumatran primates (Pongo abelii, Hylobates lar, Hylobates agilis, Presbytis thomasi, and Macaca fascicularis) and two African great apes (Pan paniscus and Pan troglodytes schweinfurthii) using both microwear texture analysis and microwear feature analysis techniques. Statistical results for texture analysis show that there are significant differences in scale of maximum and heterogeneity. This indicates that some species have large pits on their canine surfaces, having these dominated by deep features at coarse scale yet have a slight microwear heterogeneity. For feature analysis, all variables show statistically significant variation. Variance in …

Use Patterns And Influencing Factors Of Irrigation Best Management Practices In The Lower Mississippi River Basin, Merri E. Day

Graduate Theses and Dissertations

This study uses the 2016 Irrigation Survey from Arkansas, Louisiana, and Mississippi to document the use of irrigation best management practices (IBMPs), analyze use patterns, and use quantitative methods to determine factors that influence producers’ decisions regarding IBMPs. IBMPs included in the survey can be grouped as: field management practices (zero-grade leveling, precision-grade leveling, end blocking, warped surface, and deep tillage), water flow control practices (computerized pipe-hole selection, multiple-inlet irrigation, surge irrigation, alternate wetting and drying, cutback irrigation, flow meters, and pump timers), water recovery/storage practices (tail-water recovery system and on-farm storage reservoir), and advanced irrigation scheduling practices (soil moisture …

Integrated Weed Management Strategies For Palmer Amaranth (Amaranthus Palmeri) In Cotton And Soybean Production Systems, Rodger Bruce Farr

Graduate Theses and Dissertations

Management of Palmer amaranth [Amaranthus palmeri (S.) Wats.] in the Midsouth in soybean [Glycine max (L.)] and cotton (Gossypium hirsutum L.) production systems has become increasingly troublesome due to resistance to many of the commonly utilized herbicides in these systems. Developments have been made to utilize new chemistries as well as incorporate integrated weed management strategies to control Palmer amaranth, but questions have risen given the economic feasibility or effectiveness of these new strategies. Additionally, regulation has limited producers’ abilities to utilize some herbicide chemistries. As a result, experiments were conducted to 1) understand the utility of isoxaflutole in isoxaflutole-tolerant …

Efficacy Of Spirulina (Arthrospira Platensis) Utilization In Broiler Diets, Garrett James Mullenix

Graduate Theses and Dissertations

Spirulina (Arthrospira platensis) is a cyanobacteria microalgae that has potential as an animal feed ingredient. Five experiments were conducted to further assess its ability to serve as a protein source in broiler diets. Experiment 1 consisted of an amino acid digestibility and apparent metabolizable energy assay. The results indicated that the standardized ileal amino acid levels of spirulina are comparable with typical soybean meal. Experiment 2 assessed the performance and processing parameters of broilers fed 10% spirulina in low crude protein diets, using published digestibility coefficients. Spirulina inclusion improved footpad quality and increased redness and yellowness of the breast, skin …

Engineering Fluorescently Labeled Human Fibroblast Growth Factor One Mutants And Characterizing Their Photophysics Properties Towards Designing Fret Assays, Mamello Mohale

Graduate Theses and Dissertations

Human fibroblast growth factor one (hFGF1) belongs to a family of 22 FGF members produced by fibroblast cells. Cell signaling during physiological processes of angiogenesis and wound healing occurs when hFGF1 binds to its receptor (FGFR). However, when heterogenous homeostasis is not maintained, fibroblast cells exhibit excessive proliferation which can lead to a myriad of cancers. smFRET is an ultrasensitive distant dependent (1-10 nm) technique capable of resolving such heterogeneity in structural dynamics and binding affinities (Kd). Therefore, we successfully designed and characterized fluorescently labeled hFGF1 tracers which span the visible light region of the electromagnetic spectrum for use in …

Evaluation Of Nitrous Oxide Emissions From Furrow-Irrigated Rice On A Silt-Loam Soil In Arkansas, Jordan M. Slayden

Graduate Theses and Dissertations

As the number one rice (Oryza sativa)-producing state in the United States, Arkansas also ranks fourth as the largest user of groundwater. Recently, due to the development of drought- resistant hybrid cultivars, the furrow-irrigated rice production system has become an increasingly popular alternative to traditional flood-irrigated production with respect to conserving groundwater and maintaining yield. However, other environmental parameters, like greenhouse gas emissions, specifically nitrous oxide (N2O), have yet to be evaluated under furrow-irrigated rice. The objectives of this study were to i) evaluate the effects of site position (i.e., up-, mid-, and down-slope) and tillage treatment [i.e., conventional tillage …

Dollar Stores And Supermarket Survivability In Non-Metropolitan Us Communities, Cami Farmer

Graduate Theses and Dissertations

With the growing popularity of dollar stores, concerns have surfaced over the potential relationship between dollar stores and the closures of grocery stores. Healthy food accessibility for consumers, particularly those in rural areas, has additionally become of great interest. This thesis aims to investigate the potential relationship of dollar store presence and grocery store closures. Data used included County Business Patterns, Rural Urban Continuum Codes, American Community Survey, and authorized SNAP retailer data. The spatial distance between grocery stores and the number of dollar stores at various radii were calculated. Following the computation of the number of dollar stores surrounding …

Enzymatic Degradation Of Microcystin-Lr By Microcystinase (Mlra), Faisal Alqhtani

Graduate Theses and Dissertations

Microcystin-LR (MC-LR) is affecting the water supply worldwide. Hence, a way to eliminate this toxin is an essential target. In this study, successful cloning of the mlrA gene and producing MlrA enzyme that can degrade the cyclic MC-LR to linearized MC-LR was done. MlrA protein was expressed in Escherichia coli BL-21 (E. coli). Also, enhancing the MlrA yield by adding nickel to LB media was a success in producing more MlrA enzyme from the same volume. Even though the enzyme showed no activity after adding Ni, the enzyme was expressed at a higher yield. Furthermore, it was to investigate adding …

Winter Cover Crop Mixes: Effects On Strip-Tilled Plasticulture And No-Till Watermelon Production In Arkansas, Alden Neil Hotz

Graduate Theses and Dissertations

Watermelon, Citrullus lanatus (Thunb.) Matsum. & Nakai, producers in Arkansas grow watermelons in either plasticulture or bare-ground systems. Both systems can benefit from the use of winter cover crops for weed control and to supply nitrogen (N) to the watermelon crop. Currently, the use of cover crops in watermelon production in AR is mostly limited to either cereal rye (Secale cereale L.) or winter wheat (Triticum aestivum L). The objective of this research is to evaluate the potential benefits of growing a mix of a legume and grass cover crops before watermelon production in both a strip-till plasticulture and a …

Effects Of Extrinsic And Intrinsic Factors On Meat Quality And Muscle Biology Of Livestock, Yongjie Wang

Graduate Theses and Dissertations

In order to improve the meat quality of livestock, intrinsic and extrinsic factors that impact meat quality have been studied for a long time to optimize production quality. Nutrition, breed, and environment are the three most common factors to improve meat quality and muscle growth. The objective of this thesis is to perform a horizontal comparison of the effects of crude protein levels, breeds, and topsoil on the growth performance, muscle development, and meat quality of livestock, and also a longitudinal analysis using RNA-seq, RT-qPCR, and Western-blot to investigate the changes in genes and proteins related to muscle growth, and …

Comparing Organic And Conventional Yield Responses To Climate Variations, Joost Wilken Meyer

Graduate Theses and Dissertations

This thesis compares the responses of organic yields and conventional yields towards climate variations. To achieve this objective, weather variables such as growing season weather conditions (average temperature, precipitation, cloud cover, relative humidity, drought index), weather anomalies, the occurrence of severe or extreme droughts and excessive rainfalls, are combined with 23 data sets gathered from previous studies that compare organic and conventional yields from the same location and time periods. To narrow the scope, the thesis focuses on soybean, maize, and wheat production in Europe and North America. Study-level fixed-effects models are used to control for any time-invariant factors such …

Nutrient Uptake And Management Strategies In Recirculating Hydroponic Systems, Lauren Leigh Houston

Graduate Theses and Dissertations

Nutrient management in recirculating hydroponic systems requires the periodic replenishment of water and nutrients to the nutrient solution reservoir. Common nutrient management strategies, such as replenishing the reservoir with fresh solution and maintaining a constant solution electrical conductivity (EC), can lead to ion accumulation and nutrient imbalances since nutrients are taken up by roots and depleted from solution at different rates. To avoid nutritional disorders, commercial growers typically dump and replace the hydroponic solution periodically, which is wasteful and has an economic cost. A potential alternative is to specially formulate the nutrient replenishment solution to balance the supply of nutrients …

Genetic Control Of Sweetness, Acidity, And Seediness In Blackberry, Carly Elizabeth Godwin

Graduate Theses and Dissertations

The global blackberry (Rubus L. subgenus Rubus Watson) industry has experienced rapid growth during the past 15 years. Even so, many industry stakeholders report complaints from consumers and grocers stating blackberries are often too tart, too seedy, or not sweet enough for their liking. The development of molecular markers for high sweetness, low acidity, and reduced seediness would allow breeding programs to expeditiously make selection and crossing decisions in the early stages of the breeding pipeline. The objective of this study was to use a Genome-Wide Association Study (GWAS) to identify marker-trait associations, locate quantitative trait loci (QTL), and find …

Crispr Gene Editing Drivers, Barriers And Prospects: A Comparative Study Among Plant Scientists Globally, Adriaan Johannes De Lange

Graduate Theses and Dissertations

The introduction of CRISPR gene editing into food crops has potential to contribute to food security and sustainable food production globally. To date, most scientific studies have focused on consumer perception of CRISPR gene edited foods or the potential benefits and risks of the CRISPR technology and none have focused on the perceptions of plant scientists concerning CRISPR gene editing. This study aimed to explore the investments, functions, barriers, benefits for specific crops and beneficiaries of CRISPR gene editing according to plant scientists, by distributing an online survey in which 1,040 plant scientists active across six continents and in both …

Role Of Sex Differences On Cancer Cachexia Progression And Fibrosis During Cancer Cachexia Development, Wesley Haynie

Graduate Theses and Dissertations

Cancer cachexia is a multifactorial wasting syndrome characterized by losses in bodymass >5% and occurs in approximately 80% of all cancer patients. Chronic inflammation and fibrosis play roles in cancer cachexia and a greater understanding of these contributing pathways to this pathology will pave the way for potential therapeutic avenues. While inflammation and fibrosis have been researched in various models of cancer cachexia, little to no studies have been performed in both sexes as most previous studies focus on males. PURPOSE The purpose of these studies is to investigate the role of fibrosis on cancer cachexia development as well as …

Development And Evaluation Of Models For Hatchery-Mediated Infection Of Neonatal Broiler Chicks, Brittany Danielle Graham

Graduate Theses and Dissertations

Formaldehyde fumigation has been used to control the microbial load in commercial hatch cabinets. The hatch cabinet environment promotes replication and dissemination of both apathogenic and pathogenic microorganisms. As the microbial load increases during the hatching phase, formaldehyde eliminates airborne microorganisms circulating in the hatch cabinet environment. Due to the hazardous properties of formaldehyde, non-toxic alternatives to formaldehyde fumigation to control the microbial bloom in hatch cabinets are needed. The objectives of the present dissertation were to develop challenge models using singular or multiple microorganisms associated with the microbial bloom to simulate contamination that occurs in commercial hatch cabinets. Initially, …

How Are Agricultural Research Projects Conceiving Innovation? An Assessment Of The European Union Multi-Actor Projects, Samuel Brea Martinez-Collado

Graduate Theses and Dissertations

Horizon research programs are the European Union’s lighthouse for innovation and research concerning the agri-food chain, the management of natural resources, and the bioeconomy. Their innovation strategy approach is one that pursues the practical application of the research via the collaboration of all actors involved. Such strategy is the reflection of a Multi-Actor Approach as their procedure to enhance innovation. This paper presents the main trends and directions 101 Multi-Actor Projects (MAPs) are following on said approach towards innovation. The analysis is based on the use of well-defined “pathways” and “measures” proposed in the Guidelines for Evaluation of Innovation in …

New Titanate Bioceramic Nanomaterials For Drug Delivery And Controlled Release, Seaab Imad Sahib

Graduate Theses and Dissertations

Nanomaterials have attracted much attention for biomedical applications due to their unique characteristics that are proven to be potential in cell sensing, drug delivery, biological membrane penetration, biocompatibility, and tissue adhesion. The outcomes of this dissertation presented in chapter III-V mainly discuss new approaches in drug delivery, cellular uptake improvement, and neuronal regeneration and protection using a well-optimized titanium-based nanomaterial. In particular, Chapter III summarizes the impact of two different versions of the titanate nanowires on ameliorating the delivery of the antimicrobial and anticancer drug in vitro. Those drugs were loaded on the surface of the fabricated nanowires and characterized …

Economic Potash Fertilizer Rate Recommendations, Kimberly B. Oliver

Graduate Theses and Dissertations

This thesis is comprised of two studies that estimate profit-maximizing potassium (K) fertilizer application rates for various crops across different time periods. Estimation of profit-maximizing fertilizer-K rate (K*) for both studies considered the initial soil test level of K (STK) and yield response information, as traditional recommendations do, and added crop price and the cost of fertilizer. Profit maximum occurs where the marginal revenue from additional yield is equal to the marginal cost of applying an additional unit of fertilizer-K. The first study calculated K* for corn (Zea mays) and cotton (Gossypium hirsutum) and compared results to previous studies on …

Impact Of Planting Arrangement And Drill Row Spacing For Direct-Seeded, Delayed Flood Rice, Mary Jane Lytle

Graduate Theses and Dissertations

Direct-seeding is the most frequently utilized planting practice in Arkansas and Mid-South rice (Oryza sativa L.) production. Enhanced plant density and more rapid rice canopy formation may result from the implementation of innovative plant arrangements and spacings. Studies were initiated in 2019 and continued into 2020 to examine different cultural management practice experiments, including evaluating the impacts of planting arrangement, row spacing, and seeding rates on rice stand density, canopy coverage, grain yield, and milling yield. These small-plot trials were conducted at two locations, a silt loam site and a clay site, representative of soils produced to rice in eastern …