Life Sciences Commons^™

Conservation Of Open-Canopy-Associated Wildlife: Multi-Scale Management Impacts On Imperiled Herpetofauna, Ethan Joseph Royal

Graduate Theses and Dissertations

The loss of open-canopy ecosystems throughout North America has precipitated declines in reptile and amphibian species associated with these habitat types. Current efforts to restore open-canopy ecosystems are underway in many areas, but the local distributions of, habitat characteristics required by and the effects of management actions on many herpetofauna species are poorly understood or entirely unknown. Research examining relationships among herpetofauna and their environments is often complicated by the extremely low detectability seen in many studies. We used landscape-scale, assemblage-level surveys to investigate the occupancy patterns and habitat associations of open-canopy-associated herpetofauna in two regions, as well as gain …

The Relationship Between Psychosocial Factors And Food Waste-Related Behaviors Among College Students, Kacy Raquel Wright

Graduate Theses and Dissertations

Food waste is a significant environmental, economic, and social issue, with younger consumers as the most significant contributors. Specific behaviors, like over-purchasing food and misusing date labels, result from a complex interaction between social and psychological factors, which influence food waste among this demographic. The purpose of this study was to identify the psychosocial factors influencing food waste behaviors among college students at the University of Arkansas. Guided by the Theory of Planned Behavior, this study utilized online and face-to-face quantitative surveys, distributed to students enrolled at the University of Arkansas in the spring of 2022. Demographics, attitudes, subjective norms, …

Evaluating Flavor And Aroma Attributes Of Arkansas-Grown Horticultural Crops, Jordan Chenier

Graduate Theses and Dissertations

Arkansas has a climate and geography that allows for the production of unique horticultural crops, including hops (Humulus lupulus L.), blackberries (Rubus subgenus Rubus), and muscadine grapes (Vitis rotundifolia). These crops not only have potential for growers in Arkansas but have unique flavor and aroma attributes that impact marketability. Volatile compounds present in many different agricultural plants are the primary source of biologically-derived aromas and flavors. Therefore, the volatile and other quality attributes of hops, blackberries, and muscadine grapes were evaluated at the University of Arkansas (UA System) Division of Agriculture. The quality, volatile, and sensory attributes of four hops …

Modeling The Impact And Accelerating The Process Of Transitioning To A Sustainable Healthy Diet Through Decision Support Systems, Prince Agyemang

Graduate Theses and Dissertations

Food production and consumption are essential in human existence, yet they are implicated in the high occurrences of preventable chronic diseases and environmental degradation. Although healthy food may not necessarily be sustainable and vice versa, there is an opportunity to make our food both healthy and sustainable. Attempts have been made to conceptualize how sustainable healthy food may be produced and consumed; however, available data suggest a rise in the prevalence of health-related and negative environmental consequences of our food supply. Thus, the transition from conceptual frameworks to implementing these concepts has not always been effective. This paper explores the …

Characterization Of Blueberry (Poly)Phenolics In Foods, Their Metabolites In Human Biological Samples And Anti-Inflammatory Effects Of Phytochemicals In Vitro, Laura Felgus-Lavefve

Graduate Theses and Dissertations

Blueberries’ popularity is in part supported by the health benefits associated with their consumption. Research has strongly focused on their polyphenol and anthocyanin concentration, one of the highest amongst commonly consumed foods. Polyphenols have demonstrated antioxidant effects in vitro, and consuming polyphenol-rich foods is associated with protective effects towards non-communicable diseases, but their direct bioactivity in the human body remains to be fully understood. It is estimated that about 90 to 95% of the initial polyphenol intake reaches the colon without being absorbed. Instead, phenolic compounds go through extensive biotransformations, consisting of catabolism into smaller compounds mostly carried out by …

Using Condensed Tannin To Mitigate Tall Fescue Toxicosis, Ally Jo Grote

Graduate Theses and Dissertations

Endophyte-infected (Neotyphodium coenophialum) tall fescue, [Schedonorus arundinaceus (Shreb.)] produces ergot alkaloids. Condensed tannins could bind to ergot alkaloids and render them ineffective. The first objective was to improve the health of sheep offered endophyte-infected tall fescue by binding toxins in the rumen with condensed tannins. Non-toxic novel-endophyte infected tall fescue (NE) or toxic endophyte-infected tall fescue forage was harvested, baled at targeted moisture of 55%, wrapped within 8 hours of baling with 2 layers of net wrap and 20 layers of plastic, and ensiled for at least 60 days. Prior to feeding, forages were chopped and packed into plastic trash …

Application Of Microwave-Assisted Technology For Single-Pass Drying Of Rough Rice, Rebecca Mawusi Bruce

Graduate Theses and Dissertations

The 915 MHz industrial microwave is a novel technology that has the potential to achieve one-pass drying of rice within a short drying duration and reduce rice drying losses. However, processing recommendations for the commercialization of this technology for rice drying is lacking. The goal of this research is to provide processing conditions that are useful for the commercialization of the 915 MHz industrial microwave technology for rice drying. This was achieved by studying the impact of microwave specific energy and processing conditions such as harvest moisture content, milling duration, and aging on the physicochemical properties of a 915 MHz …

Allelopathic Effect Of Cereal Straw Extracts On Growth Of Raphidocelis Subcapitata And Microcystis Aeruginosa, Holly Wren

Graduate Theses and Dissertations

Harmful algal blooms are increasing in size, duration, and intensity around the globe. For several decades, cereal straws have been recognized as a viable algal control method, though the mechanisms by which cereal straws inhibit algae remain a topic of research. The objectives of this study were to evaluate the effectiveness of decomposing cereal straw extract, particularly rice (Oryza sativa) and barley (Hordeum vulgare) straw extract, to inhibit the green alga Raphidocelis subcapitata or cyanobacteria Microcystis aeruginosa in bioassays and to determine if the effectiveness of decomposing rice straw extract is altered by the presence of natural organic matter or …

Chondronecrosis With Osteomyelitis In Broilers: Bacterial Species Involvement And Influence Of Probiotics And Synbiotics, Amer Abdullah Hasan

Graduate Theses and Dissertations

Since 1945, the market for broiler production has evolved from a collection of smallholder poultry farms into an industry worth billions of dollars. Poultry production has not gone without challenges. Lameness in young broilers is presently a serious issue in the poultry industry for reasons of animal health and welfare, as well as significant lost production and revenue. Bacterial chondronecrosis with osteomyelitis (BCO) is a major form of lameness in broilers. This dissertation contains information about (i) the influence of Staphylococcus agnetis, Staphylococcus saprophyticus, Staphylococcus epidermidis and Enterococcus faecalis on inducing BCO lameness, (ii) evaluation of of probiotics for reducing …

The Effect Of Water Management And Ratoon Rice Cropping On Methane Emissions And Harvest Yield In Arkansas, Marguerita Leavitt

Graduate Theses and Dissertations

Sustainable intensification of rice farming is crucial to meeting human food needs while reducing environmental impacts. Rice produces 8% of all anthropogenic CH4, which is a potent greenhouse gas. CH4 emissions can potentially be reduced by cultivation practices that minimize the number of days the fields are saturated, such as dry-seeding instead of water-seeding and irrigation using the alternate wetting and drying (AWD) technique instead of delayed, continuous flooding (DF). Ratoon cropping, wherein a second crop of rice is grown from the harvested stubble of the first crop, can be used to produce additional yield with minimal labor, but may …

Effects Of An Injectable Zinc Solution At Weaning As An Alternative Castration Method In Beef Cattle, Reagan Nicole Cauble

Graduate Theses and Dissertations

Two experiments were conducted to investigate a 1 mL intratesticular zinc (100 mg Zn) injection administered into each testicle at weaning (Z) and its effects on growth, health, behavior and testosterone. In the first experiment, beef bulls were assigned randomly to treatment at birth: 1) surgically castrated at birth (S; n = 37) or 2) Z (n = 37). Testicular thickness differed by day (P < 0.01) for Z. Testosterone concentrations were greater in Z by d 77 and remained so through d 280 (P = 0.02) compared to S. Zinc injected calves were heavier at the trail’s conclusion (P ≤ 0.04), had greater ADG overall (P < 0.01), heavier hot carcass weight (P = 0.01), and greater lean muscle area (P = 0.01) compared to S; but a lower marbling score (P < 0.01). Yield Grade, dressed carcass yield and fat thickness were similar (P ≥ 0.14). Zinc injected calves had greater haptoglobin (Hp) concentrations (P < 0.01). Zinc injected calves had greater concentrations of white blood cells on d 1 and 2 and greater concentrations and proportions of neutrophils on d 1, 2 and 3 (P < 0.01). Conversely, S had a greater percentage of lymphocytes on d 1, 2 and 3 and a lower ratio of neutrophils to lymphocytes during that same time (P < 0.01). Zinc injected calves spent more time on their side or sternum on d 1 and more time on their side on d 2 while S spend more time standing during that time (P < 0.01). During d 3, 4, 5, and 6, Z stood more while S laid on their sternum (P < 0.01). In trail 2, beef bulls were allocated randomly to treatment one week post weaning: 1) banded (B; n = 42) or 2) Z (n = 39). Body weights were similar (P ≥ 0.39) but ADG improved for Z compared to B (P = 0.05). Testosterone concentrations were greater in Z compared to B (P ≤ 0.02). Testicular width in Z differed by d (P < 0.01). Zinc castrated calves spent more time on their side compared to B one day post castration (P = 0.03) until d 3 and 4 where B spent more time on their side (P ≤ 0.02). Banded calves stood more the first two days (P ≤ 0.01). On days 3, 4, 5, and 6, Z stood more (P ≤ 0.01) while B were on their sternum (P ≤ 0.03). Banded calves had lower Hp concentrations compared to Z (P ≤ 0.01). Total white blood cell concentrations, proportions and concentrations of neutrophils, and proportion of lymphocytes were greater in Z compared to B on d 1, 2, and 3 (P ≤ 0.01). There was no interaction between treatments over time for IL1β, IL6, and TNFα expression (P ≥ 0.83). The findings in both studies indicate that intratesticular Zn injections at weaning can improve growth performance and some carcass attributes but produce a heightened inflammatory and immune response and cause discomfort. Injecting zinc, as formulated and administered in these trails, does not result in complete castration of beef calves at this age and therefore cannot be considered a true castration alternative.

Competing Behaviors Of Thermoregulation And Ambush Foraging In The Timber Rattlesnake (Crotalus Horridus Horridus): A Mechanistic Assessment Of Thermal Conduction, Larry K. Kamees

Graduate Theses and Dissertations

The interaction between the biophysical environment and ectotherm morphology elicits behaviors designed to maintain internal body temperature (Tb) within a range that promotes physiological functions. The short-term requirements of mass (energy requirements) and heat balance are subject to tradeoffs imposed by the organisms current physiological (heat and mass budgets) and environmental (biophysical, demographic, social, and predation) constraints and available resources. In temperate forests, extreme temperatures are common in summer even with intermittent sun exposure due to dense canopy cover. In Spring and Fall, temperatures can range from below freezing to 35 ℃ in 24 hrs. An ambush predator like the …

Clostridioides Difficile Biofilm And Spore Production In Response To Antibiotics And Immune Stress, Adenrele M. Oludiran

Chemistry & Biochemistry Theses & Dissertations

The development of new therapeutic options against Clostridioides difficile (C. difficile) infection is a critical public health concern, as the causative bacterium is highly resistant to multiple classes of antibiotics. C. difficile, an anaerobic spore-forming Gram-positive pathogenic bacterium, is a major cause of hospital-acquired infections. C. difficile persists in the environment and spreads the infection to new hosts in the form of dormant spores and can persist within hosts as surface-attached biofilms. These studies investigate bacterial vegetative cell survival, biofilm formation, and sporulation in response to stress. Antimicrobial host-defense peptides (HDPs) are highly effective at simultaneously modulating …

Investigating The Biorisk Of Genetically Engineered Thermosynechococcus Elongatus Bp1, Cherrelle Leah Barnes

Chemistry & Biochemistry Theses & Dissertations

Cyanobacteria, also known as blue-green algae, are an ancient group of microorganisms that use simple materials, such as sunlight, carbon dioxide and water, to produce energy while providing oxygen to the atmosphere by performing photosynthesis. Synthetic biology approaches have been employed with cyanobacteria as a platform to produce a range of products, such as biofuels, by inserting a series of genes into the cyanobacterial genome that will allow the conversion of metabolic intermediates to such desired products. Although these methods are promising, it is important to understand any potential bio-risk they pose. This research evaluates the potential bio-risk of genetically …

Framing The Needs Of School-Based Agricultural Education Teachers To Meet Twenty-First Century Programs Demands, Kayla Marsh

All Theses

Teacher attrition is a historic problem that globally is considered to be an educational crisis. SBAE is not exempt from this crisis with teacher shortages dating back to the passing of the Smith-Hughes Act in 1917. For the past three decades, researchers have studied this phenomenon to better understand the needs of SBAE teachers in order to increase recruitment and retention as well as improve work-life balance.

While several needs are recurring current efforts are not resulting in actionable change for SBAE teachers. To gain perspectives on the problem, qualitative interviews were conducted with SBAE teachers as well as an …

Characterization Of Colletotrichum Nymphaeae Isolates, Causal Pathogen Of Apple Bitter Rot, With Reduced Sensitivity To Fluazinam And Tebuconazole, Rulyu Meng

All Theses

Apple bitter rot is caused by Colletotrichum nymphaeae and other Colletotrichum species and management relies primarily on synthetic pesticides. Very few fungicides are effective against the disease and resistance has further limited their usefulness. A recent study indicated a relatively low range of EC₅₀ values (the concentration required to inhibit 50% of mycelial growth in vitro) of C. nymphaeae isolates from Brazilian apples to fluazinam and tebuconazole, two fungicides that are not routinely used for bitter rot control. Isolates on opposite sides of the range were designated either sensitive (lowest EC₅₀ values) and reduced sensitive (highest EC_{50 …}

Investigations Into Avian Skeletal Adaptations And Spine Fusion Events, Tori Huey

All Theses

Avian dinosaurs evolved skeletal adaptations resulting in numerous fused spinal structures, like the synsacrum, present in extant birds. The synsacrum is a highly fused region necessary for stiffening the spine, and it fuses the spine to the pelvic ilium. Conventional wisdom suggests that fusion occurred in ovo during embryonic development via the cartilage matrix that patterns the future vertebrae. We show that post hatch birds have intervertebral discs separating all vertebrae of the spine, leading us to re-examine this notion in chickens up to 10 weeks of age. Intervertebral discs undergo constant remodeling, then degenerate and undergo tissue clearance, followed …

The Presence And Distribution Of Crotoxin In The Rock Rattlesnake (Crotalus Lepidus), Jade Mellor

All Theses

Crotoxin and its homologs (hereafter all referred to as CTx) is a highly lethal heterodimeric beta-neurotoxin found in pitvipers (Crotalinae) and is the main driver of neurotoxic venom phenotypes (Type II). In contrast, hemorrhagic venom phenotypes (Type I) are characterized by high snake venom metalloproteinase expression and low toxicity. Although many rattlesnake species have been classified as either Type I or Type II, population level variation in venom phenotype has also been documented in several species. The presence or absence of CTx is the main component of this variation in venom phenotype and has been most widely studied in large-bodied …

Ecological And Phenotypic Diversification After A Continental Invasion In Neotropical Freshwater Stingrays, Matthew Kolmann, Fernando Pl Marques, James C. Weaver, Mason N. Dean, Joao Pedro Fontenelle, Nathan R. Lovejoy

Faculty and Staff Scholarship

Habitat transitions are key potential explanations for why some lineages have diversified and others have not—from Anolis lizards to Darwin's finches. The ecological ramifications of marine-to-freshwater transitions for fishes suggest evolutionary contingency: some lineages maintain their ancestral niches in novel habitats (niche conservatism), whereas others alter their ecological role. However, few studies have considered phenotypic, ecological, and lineage diversification concurrently to explore this issue. Here, we investigated the macroevolutionary history of the taxonomically and ecologically diverse Neotropical freshwater river rays (subfamily Potamotrygoninae), which invaded and diversified in the Amazon and other South American rivers during the late Oligocene to early …

Genome Architecture And Diverged Selection Shaping Pattern Of Genomic Differentiation In Wild Barley, Wenying Zhang, Cong Tan, Haifei Hu, Rui Pan, Yuhui Xiao, Kai Ouyang, Gaofeng Zhou, Yong Jia, Xiao-Qi Zhang, Camilla Beate Hill, Penghao Wang, Brett Chapman, Yong Han, Le Xu, Yanhao Xu, Tefera Angessa, Hao Luo, Sharon Westcott, Darshan Sharma, Eviatar Nevo, Roberto A. Barrero, Matthew I. Bellgard, Tianhua He, Xiaohai Tian, Chengdao Li

Grain and Other Field Crops Research Articles

Summary

Divergent selection of populations in contrasting environments leads to functional genomic divergence. However, the genomic architecture underlying heterogeneous genomic differentiation remains poorly understood. Here, we de novo assembled two high-quality wild barley (Hordeum spontaneum K. Koch) genomes and examined genomic differentiation andgene expression patterns under abiotic stress in two populations. These two populations had a shared ancestry and originated in close geographic proximity but experienced different selective pressures due to their contrasting micro-environments. We identified structural variants that may have played significant roles in affecting genes potentially associated with well-differentiated phenotypes such as flowering time and drought response between …

Metal Accumulation In Soils, Invertebrates, And Whiptail Lizards In The Northern Chihuahuan Desert, Allyson Benson-Pedraza

Open Access Theses & Dissertations

Smelting activities by the American Smelting and Refining Company (ASARCO) lead to the substantial release of metal pollution into the El Paso, Texas, and border cities region. To-date few studies have examined metal accumulation within vertebrate taxa in these areas. As reptiles are currently experiencing population declines globally for a variety of reasons including pollution, lizards were chosen to be evaluated for trace element (As, Cu, Cr, Cd, Pb, and Zn) concentrations. These metals were measured within soils, invertebrate prey items, and the livers of three species of whiptail lizards (Aspidoscelis) from the un-remediated University of Texas at El Paso …

Eluication Of Lipid Metabolic Pathways In Differentiating Giardia Lamblia Using High Resolution Mass Spectrometry, Cameron Ellis

Open Access Theses & Dissertations

Giardia lamblia is an intestinal protozoan found worldwide, including the U.S. This parasite exists in two morphologic stages - a replicative trophozoite and a relatively dormant yet viable cyst. While exposures of cysts to gastric acid during passage through the human stomach induces excystation, factors in the small intestine, where trophozoites colonize trigger encystation or cyst formation. Transformation into cyst stage is essential for Giardia to survive in the environment for months before infecting new hosts. Because of its small genome size (11.7 Mb), metabolic pathways in Giardia are highly reduced. As far as lipid metabolism is concerned, only limited …

Characterization Of Esxa/Esxb Heterodimer Membrane Interaction With A Novel Popc/Popg Liposome Model, Salvador Vazquez Vazquez Reyes

Open Access Theses & Dissertations

EsxA and EsxB are co-secreted as a heterodimer and have been shown to play critical roles in phagosome rupture and translocation of Mycobacterium tuberculosis into the cytosol. Current in vitro studies support a model in which the EsxA:EsxB heterodimer is dissociated upon acidification, which might allow EsxA insertion into liposome membranes. While the membrane permeabilizing activity (MPA) of EsxA has been well characterized in liposomes composed of di-oleoyl-phosphatidylcholine (DOPC), the MPA of EsxA:EsxB heterodimer has not been detected with the DOPC liposome. In this study, we established a new in vitro membrane assay to test the MPA of EsxA and …

Population Genetics Of Two Sympatric Species, The Round-Tailed Horned Lizard (Phrynosoma Modestum) And The Greater Earless Lizard (Cophosaurus Texanus), In The Indio Mountains Of West Texas, Logan Miles Horne

Open Access Theses & Dissertations

Population genetics of two sympatric species, the round-tailed horned lizard (phrynosoma modestum) and the greater earless lizard (cophosaurus texanus), in the Indio mountains of West Texas.

Environmental Weed Risk Assessment Protocol For Growing Non-Indigenous Plants In The Western Australian Rangelands, Geoff A. Moore Mr, Christine Munday Ms, Papori Barua Dr

Bulletins 4000 -

This bulletin is a post-border environmental weed risk assessment (WRA) protocol which is based on the Environmental WRA Protocol developed for the Future Farm Industries Co-operative Research Centre (FFI CRC), but with some changes to reflect the different environment and objectives.

The WRA protocol was developed specifically as a post-border assessment of non-indigenous species that may have agricultural value in the WA rangelands and the risk that they may become environmental weeds. Weeds can occur in many land-use systems including agriculture, horticulture and forestry; however, the focus of this protocol is on the risk that non-indigenous agricultural plants may become …

Investigation Of Dead Ocean Quahogs (Arctica Islandica) Shells On The Mid-Atlantic Bight Continental Shelf, Alyssa Leclaire

Master's Theses

Ocean quahogs, Arctica islandica, are a long-lived, widely dispersed, biomass dominate in the Mid-Atlantic; therefore, quahog shells are valuable resources for studying climate change over time. Recently, dead ocean quahog shells were discovered south and inshore of the present biogeographic range of this animal. The presence of ocean quahog shells outside the current range is presumably a consequence of past regressions and transgressions of the Cold Pool, the bottom-trapped, cool body of water that allows boreal animals to live at lower latitudes. Dead ocean quahog shells were collected offshore of the DelMarVa Peninsula then radiocarbon-dated, evaluated for taphonomic condition, …

De Novo Transcriptome Analysis Of Orange Jasmine (Murraya Paniculata) Infected With Citrus Greening Disease, Jeffrey Aquino Gomez

Theses and Dissertations

Citrus greening disease, also known as Huanglongbing, is one of the most devastating citrus diseases in the world. Candidatus Liberibacter asiaticus (CLas) is a non-culturable, phloem-limited bacterium that serves as one of two vectors for the transmission of any of the three kinds of greening disease. In cooler climates, the African variant transmitted by the African citrus psyllid (Trioza erytreae) is more prevalent. The Asian form transmitted by the Asian citrus psyllid (Diaphorina citri) where is predominant in warmer conditions and recently discover the American form who is also transmit by Diaphorina citri, was discover in Brazil but has also …

A Review Of Heat Stress In Chickens. Part Ii: Insights Into Protein And Energy Utilization And Feeding, Jean-Remi Teyssier, Giorgio Brugaletta, Federico Sirri, Sami Dridi, Samuel J. Rochell

Poultry Science Faculty Publications and Presentations

With the growing global demand for animal protein and rising temperatures caused by climate change, heat stress (HS) is one of the main emerging environmental challenges for the poultry industry. Commercially-reared birds are particularly sensitive to hot temperatures, so adopting production systems that mitigate the adverse effects of HS on bird performance is essential and requires a holistic approach. Feeding and nutrition can play important roles in limiting the heat load on birds; therefore, this review aims to describe the effects of HS on feed intake (FI) and nutrient digestibility and to highlight feeding strategies and nutritional solutions to potentially …

Changes In The Expression Of Inflammatory And Epigenetic-Modulatory Genes After An Intensive Meditation Retreat, Maria Jesus Alvarez-Lopez, Quinn A. Conklin, Marta Cosin-Tomas, Grant S. Shields, Brandon G. King, Anthony P. Zanesco, Perla Kaliman, Clifford D. Saron

Psychological Science Faculty Publications and Presentations

Background

Method

Investigating The Role Of The Three N-Terminal Hamp Domains Of The Aer2 Chemoreceptor From Pseudomonas Aeruginosa, Selina Anaya

Loma Linda University Electronic Theses, Dissertations & Projects

Pseudomonas aeruginosa is a ubiquitous environmental bacterium and opportunistic human pathogen. It readily adapts to changing environmental conditions with the aid of 26 chemoreceptors that signal to four distinct chemosensory systems. The Aer2 chemoreceptor from P. aeruginosa is an O2 sensor implicated in stress responses, virulence and fine-tuning the chemotaxis (Che) system. Aer2 is the sole chemoreceptor of the Che2 chemosensory system, which forms complexes at the cell pole during stationary phase. Aer2 is soluble, yet membrane-associated and displays an unusual arrangement with its PAS sensing domain sandwiched between three N-terminal and two C-terminal HAMP domains. HAMP domains are widespread …