Life Sciences Commons^™

Effects Of The Sea Level Rise And Hurricanes In The Coastal Forest Of South Carolina, Siddhartha Regmi

All Theses

Accessing the mortality of the trees following any disturbances is of great interest to researchers in forestry science. This thesis project assessed topographic factors to explain the patterns of tree mortality after Hurricane Hugo in 1989 and investigated continuous tree mortality in relationship to important covariates using long-term data. Aerial photographs were taken one year after Hurricane Hugo, and long-term monitoring plots were set up five years after the hurricane to collect multi-year data. Analysis and visualization showed higher mortality in concave areas near the marsh at approximately 1-2m elevation and 120-180m far from streams after Hurricane Hugo. A model …

I’M A Forest, Not A Saltmarsh, Captain: Carbon And Sap Flow Dynamics In Coastal Forested Wetlands Of The Southeastern United States, Chris Shipway

All Theses

Coastal forested wetlands are identified as some of the highest-priority ecosystems for climate change mitigation. Here, we present two studies conducted in these unique ecosystems.

The first assessed changes in aboveground vegetative C stocks along the estuarine-riverine gradients of the Winyah Bay in South Carolina and the Savannah River in Georgia, using a space-for-time substitution to increase understanding of the impacts to upper estuarine forested wetlands from relative sea level rise. Standing C stocks on the Savannah River averaged 183.6 Mg C ha^-1, while sites on the Winyah system averaged 162.3 Mg C ha^-1. The largest …

Unraveling Wetland Ecology: The Effect Of Abiotic Heterogeneity And Habitat Size On Wetland Plant Diversity In The Piedmont, Gregory T. Gilmore

All Theses

Ecosystems around the world are seeing an unprecedented decline in biodiversity. However, to better prevent this decline we cannot only understand the drivers of biodiversity loss, but also the factors that support diversity. Traditional ecological hypotheses such as the Habitat Heterogeneity Hypothesis (HHH) and the Theory of Island Biogeography (TIB) have provided frameworks for understanding biodiversity drivers. However, recent research suggests a more nuanced relationship between heterogeneity, habitat size, and diversity than previously thought. This study looks to bridge existing research gaps by examining the ecologically and conservational important habitat of wetlands. Specifically, the study focuses on the plant diversity …

The Multi-Trophic Effects Of Buckthorn Removal, Amanda Jacobs

Great Lakes Center Masters Theses

European buckthorn (Rhamnus cathartica) is a non-native woody plant in North America that often grows in dense, monotypic stands, frequently displacing native plants and reducing species richness of invaded native communities. Given that plants are basal in most food webs, the homogenization of plant communities might be expected to cascade into homogenization at higher trophic levels (Hunter and Price, 1992). I investigated the multi-trophic effects of buckthorn removal at three levels: (1) ‘native,’ in which there were no buckthorn trees or shrubs, (2) ‘buckthorn trees,’ in which buckthorn was not removed and grew into spaced mature trees, and …

Employer's Perceptions Of The Agricultural Leadership Development Program At The University Of Arkansas, Samantha Jones

Graduate Theses and Dissertations

A review of the literature revealed a lack of peer-reviewed research on employer perceptions and expectations for agricultural leadership (AGLE) graduates. This study aimed to address this gap by identifying competencies necessary for effective education in AGLE programs. Utilizing a survey design, numerical data and qualitative responses, converted into numeric data to analyze frequency of concept occurrences were reported. A questionnaire, developed based on this study’s objectives and the Program System Model, was distributed to employers at the 2023 Dale Bumpers College of Agricultural, Food and Life Sciences Career Fair. The survey assessed employers’ perceptions of agricultural leadership programs, the …

Approaches To Controlling Palmer Amaranth And Its Interference In Furrow-Irrigated Rice, Tanner Austin King

Graduate Theses and Dissertations

Palmer amaranth (Amaranthus palmeri S. Wats) is the most troublesome and problematic weed in most mid-southern U.S. row crop production systems. With the increased adoption of furrow-irrigated rice (Oryza sativa L.), there is a greater occurrence of Palmer amaranth due to sustained moist conditions allowing continual emergence of the weed throughout the growing season. Palmer amaranth has previously been shown to negatively affect crop yields when left unmanaged. Therefore, there is a high potential for rice yield loss due to the weed’s ability to emerge over an extended period and interfere with crop development. However, there is a lack of …

Quantifying Physical Function: Moving Towards A New Definition And Better Assessment, Anthony Campitelli

Graduate Theses and Dissertations

Though poor physical function (PF) and disability are two of the most impactful problems facing older adults today, the field of kinesiology has not yet devised a method of measuring PF, thus limiting investigations with the potential to lead to improved PF interventions and assessments. This dissertation aimed to develop a single, continuous measure of PF using a latent variable modeling approach, and then use the generated scores to evaluate the role of lower body muscular power in PF assessment and to construct an improved PF assessment battery for predicting overall PF. Each aim of this dissertation was addressed through …

Unveiling The Intercompartmental Signaling Axis: Mitochondrial To Er Stress Response (Mersr) And Its Impact On Proteostasis, Jeson Li

Dissertations and Theses (Open Access)

Maintaining protein homeostasis is essential for cellular health. During times of protein stress, cells deploy unique defense mechanisms to achieve resolution. Our previous research uncovered a cross-compartmental Mitochondrial to Cytosolic Stress Response (MCSR), a unique stress response activated by the perturbation of mitochondrial proteostasis, which ultimately results in the improvement of proteostasis in the cytosol. Here, we found that this signaling axis also influences the unfolded protein response of the endoplasmic reticulum (UPRER), suggesting the presence of a Mitochondria to ER Stress Response (MERSR). During MERSR, the IRE1 branch of UPRER is inhibited, introducing a previously unknown regulatory component of …

Virion Composition Of Wheat Streak Mosaic Virus (Wsmv) And Its Use As An Expression Vector, Sourav Pal

Department of Plant Pathology: Dissertations, Theses, and Student Research

Wheat (Triticum aestivum L.) is the principal cereal grown in the United States, whose production ranks third in the world. Bacterial leaf streak (BLS) disease caused by Xanthomonas translucens pv. undulosa (xtu) is an emerging threat to wheat production in the Great Plains region of the United States of America. In this study, we engineered sequences encoding several plant-based antimicrobial peptides (AMP) were engineered into the WSMV genome and examined their effect on BLS disease in wheat infected by WSMV harboring AMP sequences. Out of nine AMPs, wheat expressing Ace-AMP1, PDF13, TK-AMP-D1, and TK-AMP-D3 produced resistance against the …

Transforming Grassland Conservation: Challenges And Opportunities Across Law, Policy, And Human Dimensions, Conor D. Barnes

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Great Plains social-ecological systems are facing growing pressure from complex, ‘wicked’ problems. Addressing these problems will require integrating ecological resilience and complex systems thinking concepts into our legal framework in order to better reflect the changing ecological reality of the Great Plains and promote flexibility and adaptability in the face of that change. In this dissertation, I examine how past and present policy priorities have affected social-ecological systems on the Great Plains, and how ecological resilience and complex systems thinking might be applied to grassland management policy. In Chapter 2, I examine the rapid progress made in the adoption of …

Integrating Water And Nitrogen Management For Sustainable Agriculture: Optimizing Resource Use Efficiency And Maximizing Crop Productivity, Jiaming Duan

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Advisors: Derek Heeren and Daran Rudnick Maize, accounting for over 95% of national grain production in the United States, is highly sensitive to water and nitrogen (N) inputs. Conventional agricultural practices often lead to excessive application, causing groundwater contamination through nitrate leaching. Therefore, there is a demand for integrating water and nitrogen management with innovative scheduling methods for sustainable agricultural development.

This dissertation first reviewed two decades of U.S.-based research, highlighting the optimal management of water and N to enhance yield, water use efficiency (WUE), and nitrogen use efficiency (NUE). Findings indicate that maintaining optimal levels of N and water …

A Data-Driven Discovery System For Studying Extracellular Microrna Sorting And Rna-Protein Interactions, Sasan Azizian

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Interactions between microRNAs (miRNAs) and RNA-binding proteins (RBPs) are pivotal in miRNA-mediated sorting, yet the molecular mechanisms underlying these interactions remain largely understudied. Few miRNA-binding proteins have been verified, typically requiring extensive laboratory work. This study introduces DeepMiRBP, a novel hybrid deep learning model designed to predict microRNA-binding proteins. The model integrates Bidirectional Long Short-Term Memory (Bi-LSTM) networks with attention mechanisms, transfer learning, and cosine similarity to offer a robust computational approach for inferring miRNA-protein interactions.

DeepMiRBP is implemented through two distinct architectures. The first architecture employs a Y-shaped model that uses Bi-LSTM networks and transfer learning to extract contextual …

Role Of The Malate Dehydrogenase-Citrate Synthase Metabolon In Metabolic Flux Regulation, Joy John Omini

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The TCA cycle enzymes- malate dehydrogenase (MDH) and citrate synthase (CS)- interact to transfer oxaloacetate from the active site of MDH to the active site of CS, through an electropositive channel. The MDH-CS metabolon is highly conserved across different domains of life, and it has been associated with many advantages. Some of these advantages include protecting oxaloacetate from competing enzymes like aspartate aminotransferase, allowing the thermodynamically unfavorable MDH forward reaction to occur and increasing the local concentration of oxaloacetate within the active site of CS. These advantages and conservativeness of the MDH-CS metabolon indicate that it is highly important to …

Dynamics Of Soybean Seed Protein And Oil Content With Depth In The Canopy, Hafith Furqoni

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Understanding the physiological basis of variation in seed composition is critical for optimizing soybean seed composition. Also, studying dry matter accumulation and nitrogen uptake, partitioning, and redistribution in soybeans is crucial due to its direct impact on seed yield levels and overall plant productivity. This study aimed to test the primary proxy influencing seed protein and oil content, which is their accumulation rate determined by the assimilate supply per seed. The second objective was to comprehensively understand soybean dry matter (DM) accumulation and nitrogen (N) uptake, partitioning, and removal patterns within the canopy. Field experiments were conducted using two soybean …

The Effects Of Anchor Scheme On The Central And Peripheral Contributions To Performance Fatigability, Perceived Responses And Sensations, And Psychological Factors Following Sustained, Isometric Forearm Flexion Tasks To Failure, Robert Walker Smith

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The Effects of Anchor Scheme on the Central and Peripheral Contributions to Performance Fatigability, Perceived Responses and Sensations, and Psychological Factors Following Sustained, Isometric Forearm Flexion Tasks to Failure Robert W. Smith, Ph.D. University of Nebraska, 2024 Advisor: Terry J. Housh This study assessed time to task failure (TTF), performance fatigability (PF), neuromuscular responses, central and peripheral measures of fatigue, and perceived responses including sensations and psychological factors that contributed to task termination during sustained, isometric forearm flexion tasks anchored to ratings of perceived exertion (RPE) and the torque corresponding to RPE. Fifteen men (age = 21.5 ± 2.3 yrs; …

Impacts Of Invasive Carp And Their Population Dynamics On Fish Communities In The Missouri River, Joshua F. Kocik

School of Natural Resources: Dissertations, Theses, and Student Research

Invasive Carp species: Silver Carp Hypophthalmichthys molitrix, Bighead Carp Hypophthalmichthys nobilis, Grass Carp Ctenopharyngodon idella, and Black Carp Mylopharyngodon piceus have both potential and realized abilities to negatively impact native species. Specifically, Bighead Carp and Silver Carp as filter feeders have been theorized to be detrimental not only to adult filter-feeding species, but to many fish which rely on plankton and algae in their early-life stages. The impact of Invasive Carp on the overall fish community remains underexplored. The fish communities below Gavins Point Dam (Invasive Carp present) and Fort Randall Dam (Invasive Carp absent) afford the …

Spatiotemporal Plasticity In Reproductive Readiness And Recruitment Of Ichthyoplankton Of Invasive Silver Carp Along A Western Invasion Front, Jessi L. Urichich

School of Natural Resources: Dissertations, Theses, and Student Research

Individuals of invasive species at the edge of their invasion distribution may exhibit enhanced reproductive capacity and phenotypic plasticity leading to accelerated range expansion. Environmental conditions in highly fluctuating environments at distribution edges may either promote or hinder such reproductive readiness and phenotypic plasticity. Dynamic habitat conditions and periodic disturbances experienced in prairie streams, such as drought (e.g., low-flow, high water temperatures), may potentially reduce suitable spawning environments and ichthyoplankton recruitment of invasive Silver Carp, potentially slowing range expansion or enabling management strategies that reduce abundance in the absence of a reproducing population. Female Silver Carp batch fecundity, Gonadosomatic Index …

Assessing, Restoring, And Centering Social–Ecological Relationships For Advancing Social–Ecological Resilience In The Northern Great Plains Grasslands, Katia Pilar Carranza Bernal

School of Natural Resources: Dissertations, Theses, and Student Research

The Northern Great Plains grasslands are social-ecological systems that were shaped by evolutionary and Indigenous social-ecological relationships. European colonization disrupted many of these interactions, including the coupling of fire and grazing, and degraded social-ecological resilience, shifting these grasslands to a new state. For those reasons, my research focused on assessing, restoring, and centering evolutionary and Indigenous social-ecological relationships for advancing social-ecological resilience in the Northern Great Plains grasslands. I first performed a study in the Nebraska Sandhillls assessing the potential of patch-burn grazing to support grassland resilience by comparing its effects to those of rotational grazing. Through vegetation and bird …

Assessment Of The Drivers Of Adoption Of Climate Smart Agriculture Practices Among Field Crop Farmers In Zambia, Faindani Nyirenda

Graduate Theses and Dissertations

Climate smart agriculture (CSA) practiced has been promoted in Zambia since the 1980s to address the declining crop productivity due to increased occurrence of drought or dry spells caused by climate change. Despite considerable research indicating that CSA practices have many potential benefits such as increased yield and income, the adoption rate in southern Africa is still low especially where farmers have stable off farm income. This might be because most of the research and promotion has been directed to the main staple crop maize and other context specific impacts related to agroecological and socioeconomic heterogeneity. In this study we …

B.R. Wells Arkansas Rice Research Studies 2023, 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 49.0% of total U.S. rice production and 49.6% of the total acres planted to rice in 2023. 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 …

Manipulation Of Cellular Proliferating Cell Nuclear Antigen (Pcna) During Herpes Simplex Virus Type 1 Infection, Jessica Packard, Jill A. Dembowski

Electronic Theses and Dissertations

Herpes simplex virus type 1 (HSV-1) is a double stranded DNA virus that replicates within the nucleus of host cells. Using accelerated native isolation of proteins on nascent DNA (aniPOND), cellular proteins were found to associate with HSV-1 replication forks. One host factor of interest is proliferating cell nuclear antigen (PCNA), the DNA sliding clamp that tethers DNA polymerases and DNA damage response proteins to replicating cellular DNA. Although HSV-1 encodes its own DNA polymerase processivity factor (UL42), PCNA plays a key role in HSV-1 infection. We used commercially available PCNA inhibitors and short hairpin RNAs (shRNA) to investigate how …

Biochar Impacts On Soil And Sagebrush Seedling Establishment Across A Natural Recovery Gradient In The Sagebrush Steppe, Ashley Leavell

Boise State University Theses and Dissertations

Large areas of the sagebrush steppe are destroyed by wildfire, which catalyzes invasive species growth, increases soil nitrogen availability, reduces soil water retention, and disrupts soil symbiont-plant interactions. These changes in biogeochemical properties may explain why restoration success remains limited. Biochar is a soil amendment created from pyrolyzed plant biomass that may reduce soil N availability and increase water retention. Our study aims to evaluate whether changing soil properties using biochar may enhance the survival of sagebrush seedlings. We installed an experiment south of Boise, Idaho at a site that burned in 1983. Nursery-grown sagebrush seedlings were hand-planted in November …

Challenges Of The Fentanyl Epidemic: Understanding The Crisis, Analyzing The Analogs, And Investigating The Detection Methods, Sophia Hontzas

Graduate Student Dissertations, Theses, Capstones, and Portfolios

The fentanyl epidemic has become a significant public health concern, identified by a rise in overdose deaths pertaining to the use of illicitly manufactured fentanyl (IMF). In 2021 alone, there were 70,601 overdose deaths attributed to fentanyl, emphasizing the severity of the crisis. This paper discusses the challenges posed by fentanyl and its analogs, investigating the origins, market dynamics, biological impacts, and the issues with detection and regulation. While fentanyl was initially created as a potent pain reliever, its misuse has grown due to the presence of new analogs. Case studies provide insight into how fentanyl rose in popularity and …

An Examination Of The Impact Of College Health And Wellness Courses On Mental Health – Two Paper Format: A Literature Review And A Comparison Of The Impact Of Two College Health And Wellness Courses On Affect, Perceived Stress, And Cognitive Distortions, Robin Phipps Woodall

Boise State University Theses and Dissertations

Objective: To compare the impact of two 15-week health and wellness courses on mental health measures in college students. Participants: College student volunteers were recruited after enrolling in one of two 15-week health and wellness courses. Methods: The control course (N=19) had an ethical emphasis, and the experimental course (N=21) had a cognitive behavioral emphasis. Participants completed a demographic questionnaire and pre- and post-tests of the Perceived Stress Scale, the Positive and Negative Affect Schedule-General Form, and the Cognitive Distortion Questionnaire. Pre- to Post-Changes were analyzed using a mixed model repeated measures ANOVA between the two courses. Results: Both courses …

Measurement Reliability For Intentions To Change Behavior, Emily Schlichtig

Graduate Theses and Dissertations

It is common for researchers to ask participants to associate probabilities with words, often using tools like the Likert scale to measure behavioral intentions and attitudes. However, it remains unclear what specific probabilities participants assign to the response options on a Likert scale, how much variation exists across these options, and whether these probabilities differ across various behaviors. The purpose of this paper is to explore the numeric probabilities that participants associate with different Likert scale points, to understand their perception of the variation at each point, and to compare these perceptions across three behaviors: eating more vegetables, exercising more, …

A Practical Guide To Data Management And Sharing For Biomedical Laboratory Researchers., K Fouad, R Vavrek, M C Surles-Zeigler, J R Huie, H L Radabaugh, G G Gurkoff, U Visser, J S Grethe, M E Martone, A R Ferguson, John C. Gensel, A Torres-Espin

Physiology Faculty Publications

Effective data management and sharing have become increasingly crucial in biomedical research; however, many laboratory researchers lack the necessary tools and knowledge to address this challenge. This article provides an introductory guide into research data management (RDM), and the importance of FAIR (Findable, Accessible, Interoperable, and Reusable) data-sharing principles for laboratory researchers produced by practicing scientists. We explore the advantages of implementing organized data management strategies and introduce key concepts such as data standards, data documentation, and the distinction between machine and human-readable data formats. Furthermore, we offer practical guidance for creating a data management plan and establishing efficient data …

Elucidating The Roles Of Septin Proteins In Thermotolerance And Cell Wall Integrity In Cryptococcus Neoformans, Stephani S. Martinez Barrera

All Dissertations

Cryptococcus neoformans is a globally distributed fungal pathogen responsible for causing cryptococcal meningitis in immunocompromised individuals. This pathogenic yeast must adapt to changes in temperature upon entering the human host. Septin proteins are conserved filament-forming GTPases that assemble as higher-order complexes at the cell cortex to support cytokinesis and morphogenesis in fungal and animal cells. In C. neoformans, four septin homologs (Cdc3, Cdc10, Cdc11, and Cdc12) assemble at the mother-bud neck, contributing to cytokinesis through poorly understood mechanisms. C. neoformans strains lacking the septins Cdc3 or Cdc12 are viable at 25°C, but fail to proliferate at 37°C, and are …

Investigating The Adaptive Potential Of Leaf Variegation In Two Dimorphic Hexastylis Species, Cierra N. Sullivan

All Dissertations

Variegated leaves with disjointed, patterned coloration of the leaf blade are often hypothesized to have decreased photosynthetic capacity in comparison to uniformly colored leaves. Yet, many forest understory plants in tropical, subtropical, and temperate climates possess leaf variegation. Moreover, mixed findings from previous research on the physiological impacts of leaf variegation suggest variegation is adaptative under certain environmental conditions despite decreased photosynthetic tissue area. I take an eco-physiological approach to investigate agents of selection maintaining a leaf variegation polymorphism in Hexastylis, which has both quantitative and qualitative variation in variegation. First, I conduct field surveys of morph frequencies, quantitative …

Me, Not-Me: Voice Note Use Predicts Self-Voice Recognition And Liking, Justin Thomas, Jigar Jogia, Mariapaola Barbato, Richard Bentall

All Works

Voice notes, spoken messages recorded and sent via smartphones, have become a widespread means of communication. A likely consequence of this situation is that voice note users become more frequently exposed to recordings of their own voices (self-voices). This correlational study examined if frequent exposure to recordings of the self-voice via voice note replay was associated with improved self-voice recognition (accuracy and response latency) and self-voice liking. Participants (N = 128), regular voice note users, reported voice note replay frequency. They also reported self-voice satisfaction/liking. Finally, participants completed a novel self-voice recognition task, where, across 20 trials, they identified whether …

Enzyme-Enhanced Ecf Bleaching: Improving Pulp Bleachability And Reducing Its Environmental Footprint, Bingyao Zhou

Dissertations

Enzymes have emerged as effective biocatalysts and environmentally friendly agents in pulp bleaching processes. Despite their potential, the fundamental chemistry underlying enzyme action on pulp fibers during bleaching remains poorly understood, limiting their widespread industrial application. This dissertation aims to investigate how enzymes interact with the chemical components of pulp fibers and their impact on elemental chlorine-free (ECF) bleaching in terms of pulp brightness, chemical consumption, and AOX generation.

Enzymatic pretreatment prior to ECF bleaching sequences was conducted on hardwood and softwood kraft pulp. Xylanase pretreatment significantly reduced chlorine dioxide consumption and enhanced pulp brightness in hardwood kraft pulp. Optimal …