Life Sciences Commons^™

Toxicity Of Different Insecticides To Sitophilus Oryzae, Tribolium Castaeneum And Tribolium Confusum Infesting Corn, Amina Twaibu

Graduate Theses and Dissertations

Corn is an important cereal crop cultivated across various countries, including the United States. Corn serves multiple purposes such as human and livestock food and raw material for industrial processes. Despite being an important crop, corn production faces challenges due to factors such as weather fluctuations and the presence of insect pests and diseases, both in the field and during storage. Among these challenges, insect infestation poses a major threat, as the insect damage not only reduces the quantity and quality of the grain but also renders it unfit for human and animal consumption, leading to a decrease in market …

The Effects Of Pesticide Exposure And Diet On The Health, Reproduction, And Behavior Of Mason Bees (Osmia Spp.), Olivia Mae Kline

Graduate Theses and Dissertations

Several mason bees (Osmia spp.), such as Osmia lignaria and Osmia cornifrons, are efficient and valuable pollinators in orchards. They can be used to supplement honey bee (Apis mellifera) pollination, to improve yields and reduce costs compared to A. mellifera alone. Osmia spp. encounter many stressors in their environment, which can negatively impact their health and pollination ability. These stressors include pesticide use and habitat loss due to agricultural expansion. Apis mellifera are often used as surrogates for pesticide risk assessment, but different bee species can vary widely in their response to stressors. Therefore, research into the impact of stressors …

Generation Z’S Perceptions Of Hunting And Conservation Efforts In Arkansas, Hannah Ferguson

Graduate Theses and Dissertations

Hunting participation numbers have steadily declined since the 1980s and Generation Z is not engaging in hunting. Hunting is one of the most effective tools for managing wildlife populations and ensuring the success and local ecosystem conservation. Many wildlife stewardship institutions, such as Arkansas Game and Fish Commission in Arkansas, are funded by sales taxes imposed on firearms, ammo, and archery equipment. With a decline in hunting participation, it is imperative state-run wildlife stewardship organizations and other hunting institutions learn the best practices for communicating with younger generations. This study sought to understand Generation Z’s perceptions of hunting and conservation …

Effects Of Supplemental Trace Minerals As Amino Acid Complexed Or Inorganic Sources For Beef Cattle From Receiving Through Finishing, Robin Ashley Cheek

Graduate Theses and Dissertations

The objective of experiments was to investigate the effects of inorganic or amino acid-complexed sources of trace minerals on health, gain performance, liver mineral concentrations, and carcass characteristics of beef heifers from receiving through finishing. To investigate the effects of inorganic or amino acid-complexed sources of trace minerals (zinc, copper, manganese, and cobalt) on performance and morbidity of beef heifers during the receiving period, crossbred beef heifer calves arriving on 3 delivery dates were used in a 42-day receiving trial. Treatments consisted of supplemental zinc (360 mg/d), copper (125 mg/d), manganese (200 mg/d), and cobalt (12 mg/d) from complexed (Availa-4, …

How Does Increasing The Darkness Of A Plate Affect The Perception Of Both Bitter And Sweet Flavors?, Jessica Williams

Food Science Undergraduate Honors Theses

Extrinsic cues like plate color have been shown to effect taste perception. Previous studies conducted show a consensus that plate colors can modulate taste perception (Piqueras-Fizman et al., 2012, Stewart & Gross, 2013). No studies, however, have investigated varying color hues and their effect on taste perception. This study aims to determine whether the change in the black to white ratio of plate color can affect consumer perception of sweetness or bitterness.

We presented a group of volunteers two different brownies on plates varying from 100% white to 0% white in 25% increments. A 30:70 male to female gender ratio …

Modeling The Egyptian Goose (Alopochen Aegyptiaca) Invasion; And Future Concerns, Percival Matzinger Marshall

Graduate Theses and Dissertations

In an increasingly interconnected world, the ecological and financial cost of invasive species is expected to continue to climb through the movement of exotic biota. Understanding the driving forces behind how a species invades, what environments promote their establishment, and what impacts they are likely to have on the invaded environment are all critical for management. Waterfowl, order Anseriformes, are one such category of invasive species of concern due to their popularity of accidental introduction, ease of movement, and propensity to affect both terrestrial and aquatic ecosystems. The Egyptian Goose (Alopochen aegyptiaca) is a native to the African continent that …

Evaluation Of Biochar Rate And Hemp Cultivar For The Phytoremediation Of Heavy-Metal-Contaminated Soil From The Tar Creek Superfund Site, Dietrich Thurston

Graduate Theses and Dissertations

Soil contamination by cadmium (Cd), lead (Pb), and zinc (Zn) at the Tar Creek Superfund site in Northeast Oklahoma remains a threat to the environment and local ecosystem. Phytoremediation by industrial hemp (Cannabis sativa L.) and the use of biochar (BC) have been independently shown to be effective methods to remediate heavy-metal-contaminated soils. The objective of this greenhouse study was to evaluate the effects of industrial hemp cultivar (‘Carmagnola’ and ‘Jinma’), BC rate (0, 2, 5, and 10% by volume), soil contamination level (low, medium, and high), and their interactions on above- and belowground (AG and BG, respectively) plant dry …

Shedding In The Timber Rattlesnake: Natural Patterns, Endocrinological Underpinnings, Temporal And Energetic Effort, And Integration As A Reptilian Life History Trait, Maxwell D. Carnes-Mason

Graduate Theses and Dissertations

The semi-frequent replacement of the epidermis (ecdysis) is a characteristic trait of reptiles. Whereas all reptiles regularly engage in some degree of skin shedding, skin morphology in snakes necessitates the synchronous replacement of the entire epidermis and facilitates the subsequent removal of the old layer as a single sheet. To date, the ubiquitous process has garnered little attention from researchers because snakes shed with unpredictable timing and frequency and are exceedingly cryptic during ecdytic cycles; previously impeding detailed physiological or ecological investigations of the process in the clade. Because of the lack of study, ecdysis is often viewed as a …

Runoff Water Quality And Crop Growth As Affected By Wastewater-Derived Struvite, Machaela Morrison

Graduate Theses and Dissertations

Mined phosphate rock, used to produce phosphorus (P) fertilizers, is a finite resource. Struvite (MgNH4PO4 • 6H2O) that has been synthetically produced from a stock solution of known P and nitrogen (N) concentrations has been shown to be an effective, alternative fertilizer-P source for various crops. However, little is known about the runoff-water-quality implications from and the crop response to soil application of struvite created from an actual municipal wastewater source. This study consisted of two objectives: i) to evaluate the effects of soil [i.e., Creldon (Oxyaquic Fragiudalf), Dapue (Fluventic Hapludoll), Roxana (Typic Udifluvent), and Calloway (Aquic Fraglossudalf) series], fertilizer-P …

Investigation Of Consumer Freezing Practices, Condition And Duration On Palatability Of Beef, Elizabeth Sue Neal

Graduate Theses and Dissertations

The objective of these studies was to determine: the impact of extended periods of frozen storage duration and packaging type on palatability traits of cooked beef steaks from two muscles and the impact of freezing type and storage duration on objective and subjective measures of ground beef palatability traits. In study 1, no differences were elicited from any of the possible interactions (P= 0.95) for SSF or CL: package × muscle × freezing duration, package × muscle, package × duration or muscle × duration. However, freezing duration did impact both SSF (P < 0.01) and CL (P < 0.001). Generally, for both SSF and CL steaks that were frozen for 9-months elicited both the highest SSF values as well as the greatest percentage of CL among all treatments. In comparison, EM was impacted by the interaction (P = 0.059) of packaging type  muscle  freezing duration. Samples from OW GM stored for 9-months elicited the highest percentage of EM while fresh OW LL samples resulted in the lowest. Additionally, expressible moisture was impacted by the interaction (P = 0.047) of muscle  freezing duration. Among all treatments, GM steaks that were frozen for 9-months elicited the highest EM values and fresh LL samples the lowest EM values. Contrastingly, there was no significant difference observed in expressible moisture for the interaction (P  0.18) of package type  freezing duration or for the interaction (P = 0.70) of package type  muscle. Generally, fresh OW GM steaks resulted in the greatest concentration of lipid derived volatile compounds such as aldehydes, hydrocarbons and alcohols which contrasted sensory ratings of trained panelists that indicated oxidized and refrigerator-stale ratings increased as storage time increased for OW steaks. In study 2, The interaction of freezer treatment × storage duration impacted gumminess (P = 0.05), a TPA attribute. In greater detail, samples stored in RF for 6-months resulted in the greatest gumminess values (P < 0.001), while those stored in the CF for 12-months elicited the lowest (P < 0.001). Similarly, flavor development was also impacted by the interaction (P = 0.05) of freezer treatment × storage duration. Three lipid derived compounds were of greatest concentration among RF patties stored for 1-month. In contrast, the interaction of freezer treatment × storage duration elicited no impact on consumer ratings, SF or TBARS. Nonetheless, frozen storage duration impacted TPA, flavor development, consumer ratings, SF and TBARS as a main effect (P < 0.05), especially in regard to tenderness and juiciness. Moreover, beef flavor development, tenderness and juiciness are impacted by freezing duration, muscle, freezer type and packaging, however these factors are not necessarily independent of one another. Furthermore, the retail display period is a critical period for fresh beef steaks, especially when packaged in aerobic conditions. For optimal eating experience, beef products should be stored for extended periods in a vacuum packaging, in a designated freezer that is not opened frequently to allow for optimal air flow regulation and minimize freezer burn to improve tenderness and juiciness.

Securing Rice Safety Through Innovative Radiative Heat Treatment And Proper Storage, Faith Achieng Ouma

Graduate Theses and Dissertations

Securing the microbial safety of rice is a rising priority within the food industry, especially when used as an ingredient to manufacture ready-to-eat, minimally-processed products. Mold contamination is typically the most problematic for rice because certain species of Aspergillus produce toxic secondary metabolites known as aflatoxins, rendering the grain unfit for human and animal consumption. The objectives of this study are to: (1) investigate the effectiveness of using high-power (915 MHz frequency), short-duration microwaves (MWs) to inactivate microbes on rough rice; (2) use a three-level screening design to determine which storage factors, such as temperature, relative humidity (RH), storage duration, …

Assessment Of Dicamba And 2,4-D Residues In Palmer Amaranth And Soybean, Maria Leticia Zaccaro-Gruener, Jason K. Norsworthy, Leonard B. Piveta, L. Tom Barber, Andronikos Mauromostakos

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Off-target movement of 2,4-D and dicamba is sometimes to blame as the cause of symptoms observed in weeds growing in production fields. Pesticide regulatory authorities routinely sample tissues of weeds or crops from fields under investigation for potential illegal use of auxin herbicides. This research aimed to determine if analytical tests of herbicide residue on soybean or Palmer amaranth vegetation treated with dicamba or 2,4-D could be used to differentiate between rates applied and how the residue levels decay over a 1-mo interval. Four rates of each herbicide (1X, 0.1X, 0.01X, and 0.001X) were applied, with a 1X rate of …

Investigating And Characterizing Septin Cellular Regulators During Infection Related Development In M. Oryzae, Rinalda Proko

Graduate Theses and Dissertations

The fungus Magnaporthe oryzae causes a devastating disease of rice and wheat, called blast, which poses a major threat to food security across the planet. To enter plant tissue, M. oryzae produces a remarkable pressure-generating infection cell called an appressorium, which mechanically ruptures the tough cuticle of host leaves through the application of enormous physical force directed onto a narrow penetration structure emerging from its base. Importantly, appressorium form and functionality depends on the regulated assembly of a toroidal ring-like structure, composed of septins, which forms within its base. Septins are a family of membrane-associated GTP-binding proteins that polymerize into …

Screening A Set Of Tomato Genotypes For Resistance To Bacterial Wilt And A Genomic Wide Association Study And Genomic Prediction For Yield-Related Traits In ‘Lcp 85-384’. I. Sugarcane, Theresa Makawa Phiri

Graduate Theses and Dissertations

This thesis comprises two studies that focused on screening tomato genotypes for bacterial wilt resistance and a genome-wide association study and genomic prediction for yield-related traits in sugarcane with the aim of contributing to the breeding programs. In the first chapter, 40 tomato accessions from the USDA collection were evaluated for their resistance to Ralstonia solanacearum isolate P822 under controlled greenhouse conditions. The plants were inoculated, and disease symptoms were visually assessed. Disease severity was rated on a scale of 0 to 4, where 0 represented no wilting and 4 indicated complete leaf wilting. Among the tested accessions, five (PI …

B. R. Wells Arkansas Rice Research Studies 2022, J. Hardke, X. Sha, N. Bateman

Arkansas Agricultural Experiment Station Research Series

Arkansas is the leading rice producer in the United States. The state represents 50.1% of total U.S. rice production and 49.8% of the total acres planted to rice in 2022. Rice cultural practices vary across the state and across the U.S. However, these practices are also dynamic and continue to evolve in response to changing political, environmental, and economic times. This survey was initiated in 2002 to monitor and record changes in the way Arkansas rice producers approach their livelihood. The survey was conducted by polling county extension agents in each of the counties in Arkansas that produce rice. Questions …

Studying The Stability Of Collagen/Heparin Coatings To Be Used In Cell Therapy Applications, Gavin Mussino

Biological Sciences Undergraduate Honors Theses

This honors thesis aims to investigate the reusability and performance of cell coatings for cell therapy applications. Cell therapy, which involves the use of human cells to repair or replace damaged tissues, holds immense potential for medical advancements. However, ensuring the survival and functionality of transplanted cells remains a significant challenge. We focused on studying the effectiveness of coatings applied to cells for improved cell growth and viability. The research project involved the preparation of the coatings using a layer-by-layer method and the subsequent seeding of cells. The coated cells were then subjected to a series of experiments to assess …

The Future Of Public And Private Plant Breeding According To Plant Scientists, Lexie Burris

Graduate Theses and Dissertations

Plant breeding has been effective in addressing food insecurity by increasing agricultural yields and productivity. Historically, public plant breeding programs have long-term, integrated approaches to plant breeding research, germplasm enhancement, and variety development, but as funding is reduced the future is less certain as to areas of focus. This survey builds off those before it and asks the next logical question, if a divergence between private and public breeding is taking place, what aspects should each sector focus on? The impetus of this study was to ask opinions of plant breeders globally regarding the direction they believe the public and …

Factors Affecting Food Security And Participation In Food Pantries In The U.S., Alexis Jade Skinner

Graduate Theses and Dissertations

Given the rise in food inflation, reduction of SNAP benefits, and the increased demand for food pantry participation, a more holistic understanding of potential barriers to obtaining assistance from non-Federally regulated food pantries is warranted. In May of 2022, 625 surveys were administered to low-income participants in the United States who participated in food collection from a food pantry in the previous month. Those participants were asked to select what information they were asked to provide during their visit, including home address, place of employment, Social Security card, driver’s license, household size, blood test, or others. Some forms of the …

Evaluation Of Drought Tolerance In Usda Tomato Germplasm And Genome-Wide Association Study And Genomic Prediction Of Fusarium Wilt Resistance In Common Bean Core Collection, Kenani Edward Chiwina

Graduate Theses and Dissertations

Drought stress and Fusarium wilt disease present significant challenges to plant growth and agricultural productivity, particularly affecting crops such as tomato and common beans. To address these issues, researchers have extensively evaluated germplasm collections under field and greenhouse conditions to identify genotypes with drought tolerance and disease resistance. This study aimed to achieve two objectives. Firstly, we conducted a phenotypic evaluation of drought tolerance in USDA tomato germplasm to identify drought-tolerant accessions for future breeding programs targeting enhanced drought tolerance in tomato cultivars. Secondly, we conducted a genome-wide association study (GWAS) and genomic prediction (GP) on USDA common bean germplasm …

Evaluating Mitochondrial Dynamics And Bioenergetics In Patient-Derived Human Induced Pluripotent Stem Cells And Differentiated Derivatives Modeling Leigh Syndrome, Fibi Meshrkey

Graduate Theses and Dissertations

Mitochondrial disorders are complex diseases that involve multiple systems and result from mutations and deletions in the mitochondrial genome. Leigh syndrome (LS) is a rare and devastating primary mitochondrial disorder characterized by progressive neuromuscular degeneration. Despite its severe consequences, the clinical genotype pathophysiological underlying LS remains elusive, posing significant challenges for the development of effective therapies. The current study aims to advance our understanding of the pathology and phenotype correlation of LS by evaluating mitochondrial dynamics and bioenergetics in patient-derived human induced pluripotent stem cells (hiPSCs) and their differentiated derivatives, which serve as a reliable model of the disease. Key …

Consumer Valuation Of Rice Quality In Colombia, Juliann Phillips

Graduate Theses and Dissertations

Rice is a crucial contributor to global food security and is an important staple for over half the world’s population. In Colombia, total rice consumption has grown by 25% in the last decade (2011-2021), reaching 1.9 MMT in 2021, yet in 2021 around 15.5 million Colombians were classified as food insecure. Colombia is the third largest rice producer in Latin America, producing 1.8 million metric tons (milled basis) in 2021. Increasing rice consumption coupled with high levels of food insecurity highlights the necessity that rice markets effectively price rice according to consumer preferences. Therefore, the goal of this study focuses …

The Roles Of Estrogen Receptor Alpha-Interacting Rnas And Exosomes In Breast Cancer, And E-Cadherin In Carcinomas, Brihget Catalina Sicairos-Meza

Graduate Theses and Dissertations

Carcinomas are malignancies of epithelial cells and account for >80% of cancer-related deaths. Approximately 75% of breast cancers express estrogen receptor alpha (ERα). ERα promotes breast cancer progression by enhancing cancer cell proliferation. Tamoxifen is commonly used to treat ERα-positive breast cancers but can result in endocrine therapy resistance. The mechanisms underlying endocrine therapy resistance remain elusive. The Du lab recently found that ERα is an RNA-binding protein. However, the significance of the ERα-RNA interaction is unknown. We fractionated ERα-positive MCF7 cells into cytoplasmic and nuclear fractions, followed by immunoprecipitation of ERα with associated RNAs and RNA-sequencing. We identified many …

Unraveling The Biogenesis And Roles Of Iron-Sulfur Proteins During Nitrogen Fixation By Methanosarcina Acetivorans, Jasleen Saini

Graduate Theses and Dissertations

Iron-sulfur (Fe-S) clusters, the ancient cofactors found in proteins across all life forms, play vital roles in numerous cellular processes. Fe-S clusters exhibit structural diversity, ranging from simple to complex forms. Methanogens are anaerobic archaea that produce methane as a metabolic by-product through methanogenesis, a process dependent on numerous Fe-S proteins. Notably, methanogens are capable of fixing nitrogen (diazotrophy) facilitated by the enzyme complex called nitrogenase, which contains both simple and complex Fe-S clusters. While methanogens possess the largest number of Fe-S proteins, the factors involved in Fe-S cluster biogenesis remain largely unknown. Bacteria possess three distinct and well-characterized Fe-S …

Evaluation Of Heat Stress And Dietary Amino Acid Density On Nutrient And Energy Partitioning In Broilers, Jean-Remi Teyssier

Graduate Theses and Dissertations

The simultaneous increase in the global demand for animal-based protein products and the rise in temperature associated with global warming pose important challenges to the poultry industry. Heat stress (HS) occurs when an animal’s heat production (HP) surpasses its capacity to dissipate heat into the surrounding environment, ultimately leading to reduced feed intake (FI) and negative impacts on performance. A better understanding of bird responses to elevated temperatures is required to propose effective nutritional strategies that mitigate the adverse effects of HS. Therefore, this dissertation aimed to characterize the nutritional and physiological mechanisms explaining the loss in performance and carcass …

A Pilot Study Of Students’ Ethical Decision Making And Emotional Intelligence, Casandra K. Cox

Graduate Theses and Dissertations

Demand for ethical leaders in agriculture is high to meet 21st century goals, while ethics course offerings in land-grant institutions are limited. The purpose of this case study was to establish a baseline of current University of Arkansas Bumpers College of Agriculture, Food and Life Science (Bumpers College) agriculture and natural resource program students’ ethical decision making (EDM), as measured by the DIT-2, and emotional intelligence (EI), as measured by STEM-B and STEU-B, determine if EI mean scores predict EDM, and identify relationships between EDM or EI and demographic characteristics or lifespan experiences. An online survey design with probability sampling …

Do Fas Large Export Sales Reports Move Commodity Futures Markets?, William Johnson

Graduate Theses and Dissertations

This study sought to determine if the Large Export Reports from the USDA Foreign Agriculture Service have any discernible market-moving impact on particular commodity futures markets. The effect of the reports on futures markets is investigated using four different methods: the average return event study approach, the multiple regression with binary variables model, the autoregressive time series model, and the event spline model. The average returns showed that the FAS's Large Export Sales Reports had no influence on the pricing of wheat futures, but did have a considerable impact on the returns from days before and after the release of …

Determinants Of Market Participation Among Milk Producers In Kyrgyzstan, Akhmadjon Nurullaev

Graduate Theses and Dissertations

This study explores the key factors that drive milk producers to enter the milk market as sellers in Kyrgyzstan. The study utilizes the Life in Kyrgyzstan dataset, a nationally representative survey that tracks 3,000 households and 8,000 individuals throughout Kyrgyzstan. The results were analyzed with two different models: Heckman’s two-stage and the double hurdle models. The results show that regional location, ethnic group origin, risk awareness, dependency ratio, vehicle ownership, total value of assets, distance to agro market, and family shock occurrence significantly impact both market participation and the volume of milk sales. The findings hold great significance in establishing …

Understanding The Environmental And Genetic Influence On Fluctuating Asymmetry And Developmental Instability In Primates, Ashly N. Romero

Graduate Theses and Dissertations

This dissertation explored the impact of environmental factors on the development and perpetuation of fluctuating asymmetry (FA) and sought to understand the role evolution may play in the FA exhibited in two primate populations: the free-ranging Cayo Santiago rhesus macaques (Macaca mulatta) and the Southwest National Primate Research Center olive baboons (Papio hamadryas anubis). Demographic, ontogenetic, secular, external, and genetic factors were examined. Specifically, this dissertation investigated FA over all ontogenetic stages, across decades, between sexes, in association with ecological catastrophes, and with tooth pathology to try and tease apart factors that may influence FA and developmental instability. This dissertation …

Risk-Returns Of Forward Contracting Southern Row Crops With Crop Revenue Insurance, Chandan Bhattarai

Graduate Theses and Dissertations

This study evaluated the risk and return associated with various levels of forward contracting for southern row crops, specifically corn, soybean, and rice, in conjunction with different coverage levels of the Revenue Protection (RP) crop insurance program and government support plans. Forward contracting is a strategy to manage price risk by transferring ownership of physical grain from a seller to a buyer at a pre-agreed time. RP is a return-based crop insurance program offering coverage levels ranging from 50-85 percent in 5 percent increments, which allows producers to hedge against yield or price risks. Additionally, the study analyzed the effectiveness …

Functional Morphology Of The Platyrrhine Humerus And Talus: Implications For Inferring Locomotor Behavior In Extinct Primates, Liam Michael Zachary

Graduate Theses and Dissertations

Platyrrhines are a diverse radiation of primates that exhibit a range of locomotor adaptations. The relationships between extant primate locomotor behavior and variation in postcranial morphology are often used to make functional interpretations of skeletal anatomy in extinct primates. However, a comparative baseline of form-function relationships in the extant platyrrhine postcranium is lacking compared to other primates, which limits understanding of platyrrhine locomotor evolution. The humerus and talus are two of the best represented skeletal elements in the platyrrhine fossil record and are informative of locomotor behavior. Therefore, quantification of morphological variation in extant platyrrhine tali and humeri can provide …