Life Sciences Commons^™

Genetic Fingerprinting And Aflatoxin Production Of Aspergillus Section Flavi Associated With Groundnut In Eastern Ethiopia, Abdi Mohammed, Paola C. Faustinelli, Alemayehu Chala, Mashilla Dejene, Chemeda Fininsa, Amare Ayalew, Chris O. Ojiewo, David A. Hoisington, Victor S. Sobolev, Jaime Martínez-Castillo, Renee S. Arias

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Background: Aspergillus species cause aflatoxin contamination in groundnut kernels, being a health threat in agricultural products and leading to commodity rejection by domestic and international markets. Presence of Aspergillus flavus and A. parasiticus colonizing groundnut in eastern Ethiopia, as well as presence of aflatoxins have been reported, though in this region, no genetic studies have been done of these species in relation to their aflatoxin production. Results: In this study, 145 Aspergillus isolates obtained from groundnut kernels in eastern Ethiopia were genetically fingerprinted using 23 Insertion/Deletion (InDel) markers within the aflatoxin-biosynthesis gene cluster (ABC), identifying 133 ABC genotypes. Eighty-four isolates …

Development And Validation Of A Method For The Determination Of Designer Benzodiazepines In Hair By Liquid Chromatography Tandem Mass Spectrometry (Lc-Ms/Ms), Laura C. Defreitas

Student Theses

In recent years, new designer benzodiazepines have become a challenge in forensic toxicology. These substances are analogues of the classic benzodiazepines, but their pharmacology is not well known, and many of them have been associated with overdoses and deaths. As a result, there has been a surge in efforts to develop ways to accurately test for these compounds in different biological matrices. This study focused to develop and validate a method for determining 17 new designer benzodiazepines in hair by liquid chromatography tandem mass spectrometry (LC-MS/MS). Hair samples were decontaminated, pulverized, and 20 mg of the sample was incubated in …

Impact Of Blood Collection Tubes In Cannabinoid Quantitative Analysis, Tega E. Obruche-Akponah

Student Theses

In forensic toxicological cases, sample stability and storage are pivotal for obtaining adequate analytical results. Currently, limited information is available about the impact of different preservatives and anticoagulants present in the blood tubes used in the collection of blood samples containing cannabinoids. This study investigated the impact of sodium fluoride (gray top) and sodium citrate (blue top) blood collection tubes on the concentrations of tetrahydrocannabinol (THC), cannabidiol (CBD), cannabinol (CBN) and 5 THC metabolites (THC-OH, THC-COOH, THC-diOH, THC-glucuronide, THCCOOH-glucuronide) in whole blood samples, stored at room temperature, 4ºC and -20ºC for up to 3.5 months. The samples were extracted using …

Investigating Therapeutic Strategies To Target Metabolic Vulnerabilities Of Nsclc Tumors With Mutant Keap1 Gene, Pranavi Koppula

Dissertations and Theses (Open Access)

The metabolic vulnerability of cancers has long been envisaged as an attractive window to develop novel therapeutic strategies. Metabolic flexibility at the cellular level encompasses the efficient rerouting of anabolic and catabolic pathways in response to varying environmental stimuli to maintain cellular homeostasis and sustain proliferation. The primary objective of this study is to identify metabolic vulnerabilities bestowed by KEAP1/NRF2 signaling axis through SLC7A11. SLC7A11 is a transcriptional target of NRF2, an essential regulator of cellular anti-oxidant response. Under unstressed basal conditions, NRF2 interacts with KEAP1, a tumor suppressor gene and a substrate adaptor protein of the Cullin3-dependent ubiquitin ligase …

Stat3 Inhibits Type I Interferon Signaling In Type I Conventional Dendritic Cells, Taylor Chrisikos

Dissertations and Theses (Open Access)

Conventional dendritic cells (cDCs) are an essential immune population, responsible for controlling adaptive immunity and tolerance. Recently, type I cDCs (cDC1s) have been delineated as a distinct cDC subset, uniquely responsible for coordinating T cell-mediated immunity against pathogens and tumors. Although the importance of cDC1s is now well established, the mechanisms that regulate cDC1 function remain largely unknown. Signal Transducer and Activator of Transcription 3 (STAT3) mediates the intracellular signaling of interleukin 10 (IL-10), an immunosuppressive cytokine. Therefore, we hypothesized that STAT3 and IL-10 inhibit cDC1 function and induction of T cell-mediated immunity. Herein, we show that IL-10 inhibits polyinosinic:polycytidylic …

Modulation Of The Receptor Gating Mechanism And Allosteric Communication In Ionotropic Glutamate Receptors, Nabina Paudyal, Nabina Paudyal

Dissertations and Theses (Open Access)

Ionotropic glutamate receptors (iGluRs) found in mammalian brain are primarily known to mediate excitatory synaptic transmission crucial for learning and memory formation. The family of iGluRs consists of AMPA receptors, NMDA receptors and kainate receptors with each member having distinct physiological role. In the recent years, significant progress has been made in understanding the biophysical, and functional properties of iGluRs. The development of Cryo-EM and X-Ray crystallography techniques have further facilitated in the structural understanding of these receptors. However, the multidomain nature, large size of the protein, complex gating mechanism and inadequate knowledge regarding the conformational dynamics of the receptors …

Mutant Kras Alters Extracellular Vesicle Microrna Sorting In Pancreatic Cystic Neoplasms, Rachel L. Dittmar

Dissertations and Theses (Open Access)

Pancreatic ductal adenocarcinoma (PDAC) is among the deadliest cancers by organ site with a 5-year survival rate of just 10.8%. This is largely because most patients do not experience symptoms until the disease has already metastasized. The best hope to cure PDAC is surgery, which can only be done with a curative intent at an early stage when the disease is localized. There are no reliable circulating, body-fluid-based biomarkers to detect early stage PDAC or its precursor lesions in a timely manner for effective surgical intervention. When potential PDAC precursor lesions, such as mucinous pancreatic cysts are found, there are …

Enhancing Adoptive Cell Therapy By Augmenting Fitness And Anti-Tumor Function Of Tumor-Infiltrating Lymphocytes, Parin Shah

Dissertations and Theses (Open Access)

The success of immune checkpoint inhibitors (ICIs) has established the importance of cancer immunotherapy in solid cancers, where it has been adopted as one of the standards of care for advanced melanoma and lung cancer. It is currently being investigated to treat other solid cancers. However, a large fraction of patients do not respond to ICIs and relapse. ICI therapy offers an in vivo approach to activate tumor-specific T cells, albeit in some cases, this modality does not create a sufficiently robust anti-tumor response. Thus, ex vivo approaches employing manipulation of immune cells, such as Adoptive Cell Therapy (ACT) using …

Deciphering The Role Of Hsp110 Chaperones In Diseases Of Protein Misfolding, Unekwu M. Yakubu

Dissertations and Theses (Open Access)

Molecular chaperones maintain protein homeostasis (proteostasis) by ensuring the proper folding of polypeptides. Loss of proteostasis has been linked to the onset of numerous neurodegenerative disorders including Alzheimer’s, Parkinson’s, and Huntington’s disease. Hsp110 is a member of the Hsp70 class of molecular chaperones and acts as a nucleotide exchange factor (NEF) for Hsp70, the preeminent Hsp70-family protein folding chaperone. Hsp110 promotes rapid cycling of ADP for ATP, allowing Hsp70 to properly fold nascent or unfolded polypeptides in iterative cycles. In addition to its NEF activity, Hsp110 possesses an Hsp70-like substrate binding domain (SBD) whose biological roles are undefined. Previous work …

Agonist-Induced Conformational Changes In The Nmda Receptor, Ryan Durham, Ryan Durham

Dissertations and Theses (Open Access)

NMDA receptors are ligand-gated ion channels that mediate a number of physiological and pathological phenomena within the mammalian central nervous system. Under the typical course of activation, these receptors bind to glycine and glutamate molecules and undergo a series of conformational changes that results in the opening of a cation-permeable pore in the neuronal plasma membrane. Various aspects of NMDA receptor function are not fully understood, including the phenomenon of negative cooperativity between the glycine- and glutamate-binding sites of the receptor and the mechanism controlling partial agonism. Past studies utilizing static structural snapshots of the receptor or isolated domains of …

Atrx Inactivation And Idh1-R132h Drive Preferential Sensitivity To Proton Vs. X-Ray Radiotherapy In Glioma Stem Cells, Ángel Adrián Garcés

Dissertations and Theses (Open Access)

Background: Glioma Stem Cells (GSCs) are self-renewable, treatment resistant cells in the glioma tumor mass known to promote tumor development. In contrast to traditional photon-based radiation therapy (XRT), proton radiation therapy (PRT) may induce more complex DNA damage and therefore might have the potential to eliminate GSCs. Although previous studies have individually linked IDH mutations, specifically IDH1^R132H, and ATRX inactivating mutations to improved patient outcomes and suppressed DNA damage repair compared to their respective wild-types, the mechanisms by which these two genetic alterations interact in GSCs treated with PRT compared to XRT are currently unknown. We hypothesize that …

Quantifying Planarian Behavior As An Introduction To Object Tracking And Signal Processing, Nicole C. Stowell, T. Goel, Vir Shetty , '22, Jocelyne Noveral, Eva-Maria S. Collins

Biology Faculty Works

Answers to mechanistic questions about biological phenomena require fluency in a variety of molecular biology techniques and physical concepts. Here, we present an interdisciplinary approach to introducing undergraduate students to an important problem in the areas of animal behavior and neuroscience—the neuronal control of animal behavior. In this lab module, students explore planarian behavior by quantitative image and data analysis with freely available software and low-cost resources. Planarians are ∼1–2-cm-long aquatic free-living flatworms famous for their regeneration abilities. They are inexpensive and easy to maintain, handle, and perturb, and their fairly large size allows for image acquisition with a webcam, …

Effects Of Nitrogen Management And Cultivar On Strawberry Production Under Disease Pressure, Kamille A. Garcia-Brucher

Master's Theses

Effects of nitrogen management and cultivar on strawberry production under disease pressure

Kamille Garcia-Brucher

California strawberry growers face increasing regulatory pressures to manage nitrogen (N) applications in their production system. Standard practice in the California strawberry industry is to apply a synthetic pre-plant controlled release fertilizer (CRF) to ensure the crop has sufficient N during winter establishment. Some research from the UC Cooperative Extension suggests this practice is not efficient at delivering N to the crop since most of the N is released from CRF before strawberry crop N uptake is significant. Another concern for California strawberry growers is loss …

Ecological Outcomes Of Movement Behavior In Brown Pelicans From The South Atlantic Bight, Bradley Wilkinson

All Dissertations

Vagile organisms are expected to display movement behaviors that respond to a wide variety of both intrinsic and extrinsic factors. Identifying drivers of movement is fundamental to understanding the ecology of species, as well as implementing effective conservation measures. Technological advancements have allowed for the collection of fine-scale positional data at rapid temporal scales, which can be a powerful tool for assessing the movement behavior of tracked species and for understanding the potential fitness implications resulting from variations in animal space use. The goal of this dissertation was to identify important drivers of movement behavior and to describe the ecological …

An Assessment Of The Needs Of School-Based Agricultural Educators And Other Professionals In Agricultural Service Agencies For A Professional Online Master’S Degree In Agricultural Education, Maria Mercedes Rossi

All Dissertations

Online learning is one form of distance education mediated through information and communications technology such as the Internet or other technologies. The teaching content is delivered online, and instructors develop teaching modules that enhance their learning and interactivity (student-student, teacher-student, and content-student). Using social cognitive theory (SCT) concepts, the research team developed and validated a multidimensional instrument tool to assess the needs for a professional online master’s degree in agricultural education. The study aimed to assess participants’ readiness and motivations to learn online and identify participants’ needs and experience with online learning. Participants’ perceptions of online learning were assessed 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 …

Relative Success Of Native Plants In Curb Cut Rain Gardens, Ana Singh, Rachel Warners, Jonathan Walt, Patrick Jonker, David P. Warners

Faculty and Professional Research

No abstract provided.

Us Consumers' Perceptions Of Raw And Cooked Broken Rice, Matthew G. Richardson, Philip Glen Crandall, Han-Seok Seo, Corliss A. O'Bryan

Food Science Faculty Publications and Presentations

Rice supplies about 20% of the calories to the world’s consumers. Milling removes the outer husk and bran, breaking about 20% of the rice kernels during the milling process that equates to almost 100,000,000 tons of rice annually. Broken rice is discounted in price by almost half or relegated to non-human consumption. This study seeks to understand why this large percentage of rice production is discounted for human consumption. Consumers who routinely consume rice evaluated raw and cooked rice with 5%, 10%, 20%, 30% and 40% levels of brokens. Sensory analysis indicated the appearance of raw rice with high levels …

Potential Use For Serosurveillance Of Feral Swine To Map Risk For Anthrax Exposure, Texas, Usa, Rachel M. Maison, Courtney F. Pierce, Izabela K. Ragan, Vienna R. Brown, Michael J. Bodenchuk, Richard A. Bowen, Angela M. Bosco-Lauth

United States Department of Agriculture Wildlife Services: Staff Publications

Anthrax is a disease of concern in many mammals, including humans. Management primarily consists of prevention through vaccination and tracking clinical-level observations because environmental isolation is laborious and bacterial distribution across large geographic areas diffi cult to confi rm. Feral swine (Sus scrofa) are an invasive species with an extensive range in the southern United States that rarely succumbs to anthrax. We present evidence that feral swine might serve as biosentinels based on comparative seroprevalence in swine from historically defi ned anthrax-endemic and non–anthraxendemic regions of Texas. Overall seropositivity was 43.7% (n = 478), and logistic regression revealed county endemicity …

Boxed In: Hinge Closing Performance Of Ornate Box Turtles (Terrapene Ornata), Gina L. Buelow

Graduate Theses/Dissertations

Turtles are perhaps best known for the bony shells that encase them, a unique morphological trait that provides protection against predators. Many taxa have even evolved the ability to enclose themselves using hinges that can be used to create a seal between the carapace and plastron. I measured the hinge closing force of Ornate Box Turtles (Terrapene ornata) to assess the performance of this unusual yet ecologically important trait. I sampled head-started turtles from Thomson Sand Prairie in the Upper Mississippi River National Wildlife and Fish Refuge and wild turtles collected in northern Oklahoma. To assess the effects of head-starting …

Effects Of "Lemongrass Factor" On Galleria Mellonella Hemocytes, Jennifer C. Rice

Graduate Theses/Dissertations

The use of conventional chemical insecticides to control agricultural pest has become problematic as they may have a negative impact towards human health and the environment, resulting in a need to research alternative methods to insect pest control. Plant derived substances like essential oils have been used for generations as toxicants, repellants, and anti-feedants to control agricultural pest. More research is needed to understand how insect immune systems react to essential oils and if cellular immune responses of phagocytosis, encapsulation, and nodulation can be inhibited by such. Subjecting Galleria mellonella to various concentrations of “lemongrass factor” lets the researcher/scientist know …

Severe Acute Respiratory Syndrome Coronavirus 2 (Sars-Cov-2) Implications On Pregnancy Outcomes. What Obstetrician Should Know?, Mahmoud Mansour, Mohamed Taman, Ashraf Shoma

Mansoura Medical Journal

In less than a year, more than 60 million cases of COVID-19 were reported worldwide. Most of the data available still unclear. It affects vulnerable populations as those with lowered immunity, chronic diseases and pregnant females. Many questions have to be answered as during pregnancy care should be given to mother, fetus and neonate. Also, the obstetricians should follow the evidence-based recommendations during their routine antenatal care and during labor. We reviewed the recent and available online published researches since the outbreak of COVID-19 to know what we know about the impact of the recent pandemic on the pregnancy and …

Comparative Riverscape Genomics Of The Rainbow Darter (Etheostoma Caeruleum) In Glaciated And Unglaciated Environments, Jon M. Luiken, Tony Gamble, Peter B. Berendzen

Biological Sciences Faculty Research and Publications

Periodic glaciation during the Quaternary period shaped the contemporary riverscape and distribution of freshwater fishes in the Mississippi River drainage of central North America. The rainbow darter (Etheostoma caeruleum) is a member of this ichthyofauna and has a disjunct distribution in glaciated and unglaciated environments west of the Mississippi River. Based on glacial history of the region, there are different expectations on the observed spatial genetic structure of populations in these environments. The aim of this study was to utilize genome-wide SNP data to compare the population genomic structure of the rainbow darter in river networks with disparate …

Role Of Ataxia Telangiectasia Mutated Kinase In Western-Type Diet-Induced Cardiac Outcomes Under Basal And Ischemic Conditions, Mary Wingard

Electronic Theses and Dissertations

Ataxia-telangiectasia mutated kinase (ATM), a serine/threonine kinase, plays a role in DNA damage repair, redox sensing, and metabolism. In the heart, ATM contributes significantly in the myocardial infarction (MI)-induced cardiac remodeling with effects on fibrosis, hypertrophy, apoptosis and inflammation. This study investigates the role of ATM deficiency in 14 weeks Western-type diet (WD)-induced cardiac outcomes prior to and 1-day post-MI in a sex-specific manner using wild-type (WT) and ATM heterozygous knockout (hKO) mice. In male mice, ATM deficiency induced rapid body weight gain and preload-associated dysfunction, while WT mice displayed afterload-associated dysfunction 14 weeks post-WD. Myocyte apoptosis and hypertrophy were …

Trained Immunity Enhances The Immune Response And Maintains Microbiome Diversity In Aging And Sepsis, P. Spencer Gill

Electronic Theses and Dissertations

The global population is rapidly aging. It is estimated that over the next thirty years, the number of individuals >60 years of age will increase by over a billion, and the number of individuals over age 80 may increase by 300 million. As humans age, our immune system becomes progressively weaker through a process called immune senescence. This age-related decrease in immune function increases susceptibility to infection and chronic diseases. Sepsis is a leading cause of death worldwide. Over the past two decades, there has been an increased incidence of sepsis which is due, in part, to our aging population …

An Exploration Of The Role Of Farm Business Decisions In Addressing Financial Challenges For Missouri's Beginning Farmers, Lucas Paloschi

Graduate Theses/Dissertations

The next generation of farmers takes an important role in the food production for subsequent years. The American Farm Bureau Federation’s (2017) estimation that 70% increase of production will need to be achieved within the next 30 years set awareness across the globe. Researchers have been studying and trying to find means to aid beginning farmers in a variety of ways. This study measures farm decisions that affect financial performance of farmers aiming to facilitate beginning producers’ decision making. Three regressions were used to analyze how different variables affect farmers’ profitability and repayment capacity. Using a county-level data for the …

Is There Room In The United States Diet For Goat Meat? Analysis Of The 2019 National Goat Meat Survey, Everett Marcus Martin

Graduate Theses/Dissertations

Demand for goat meat has steadily increased in the past decade, but few studies have been conducted addressing goat meat attributes and demographic factors on consumers’ willingness to buy goat meat products. Analyzing a national consumer survey on goat meat preference, a logit modeling is used addressing factors affecting willingness to buy three goat meat products: grass-fed, locally grown, and organically raised. Results indicate that quality and freshness attribute characteristics significantly affect consumer willingness to buy grass-fed, organic, and locally grown goat meat.