Life Sciences Commons^™

Substantial Carbon Loss Respired From A Corn-Soybean Agroecosystem Highlights The Importance Of Careful Management As We Adapt To Changing Climate, Caitlin E. Moore, Christy D. Gibson, Guofang Miao, Evan C. Dracup, Nuria Gomez-Casanovas, Michael D. Masters, Jesse Miller, Adam C Von Haden, Tilden Meyers, Evan H. Delucia, Carl J. Bernacchi

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

Understanding agroecosystem carbon (C) cycle response to climate change and management is vital for maintaining their long-term C storage. We demonstrate this importance through an in-depth examination of a ten-year eddy covariance dataset from a corn-corn-soybean crop rotation grown in the Midwest United States. Ten-year average annual net ecosystem exchange (NEE) showed a net C sink of -0.39 Mg C ha-1 yr-1. However, NEE in 2014 and 2015 from the corn ecosystem was 3.58 and 2.56 Mg C ha-1 yr-1, respectively. Most C loss occurred during the growing season, when photosynthesis should dominate and C fluxes should reflect a net …

Patterning Ecological Restoration After Weeds, Stephen L. Young, Erik P. Hamerlynck

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

The United Nations Decade on Ecosystem Restoration aims to prevent, halt, and reverse the degradation of ecosystems on every continent. Disturbances stemming from anthropogenic or natural causes make plant community restoration challenging. The introduction of fast-growing weeds that generate high biomass and produce copious seed is most threatening to plant communities. A paradigm shift in ecosystem restoration is needed that emphasizes traits and affected ecological processes similar to weeds. The repeated introduction of seed from native plants with weedy characteristics follows the propagule pressure and evolution of invasiveness hypotheses. In targeting areas with heavy weed populations, native plants could establish …

Corn Nitrogen Nutrition Index Prediction Improved By Integrating Genetic, Environmental, And Management Factors With Active Canopy Sensing Using Machine Learning, Dan Li, Yuxin Miao, Curtis J. Ransom, Gregory Mac Bean, Newell R. Kitchen, Fabián G. Fernández, John E. Sawyer, James J. Camberato, Paul R. Carter, Richard B. Ferguson, David W. Franzen, Carrie A.M. Laboski, Emerson D. Nafziger, John F. Shanahan

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

Accurate nitrogen (N) diagnosis early in the growing season across diverse soil, weather, and management conditions is challenging. Strategies using multi-source data are hypothesized to perform significantly better than approaches using crop sensing information alone. The objective of this study was to evaluate, across diverse environments, the potential for integrating genetic (e.g., comparative relative maturity and growing degree units to key developmental growth stages), environmental (e.g., soil and weather), and management (e.g., seeding rate, irrigation, previous crop, and preplant N rate) information with active canopy sensor data for improved corn N nutrition index (NNI) prediction using machine learning methods. Thirteen …

Investigating The Bactericidal Activity Of Lactobacillus Crispatus Cell-Free-Supernatant, Omar Majed Abdul-Rahim

Dissertations

Antimicrobial-resistant (AMR) microorganisms are an increasingly seriousproblem worldwide, accounting for thousands of fatalities annually. The current literature on combating AMR pathogens often centers on commensal microbes such as Lactobacillus species, which are most frequently found in asymptomatic ‘healthy’ patients and are believed to elicit protective effects. In this dissertation, I sought to investigate the protective effect of Lactobacillus crispatus, utilizing our vast collection of clinical isolates. Previous work from our lab had found that cell-free-supernatant (CFS) of L. crispatus is robustly bactericidal, and that this killing activity does not depend on hydrogen peroxide or lactic acid. We identified phenyl-lactic acid …

Mechanisms Of Programmed Nutrition In Finishing Cattle In Vivo And Ruminal Parameters Of Amaize Supplementation In Vitro, Amanda Pesqueira Schiff

Theses and Dissertations--Animal and Food Sciences

Programmed Nutrition Beef Program (Alltech Inc.) is a dietary supplement that contains Aspergillus oryzae fermentation extract with α-amylase activity that could reduce the use of feed additives such as monensin and tylosin in conventional feedlot diets. This study examines the changes in rumen fermentation resulting from feeding monensin/tylosin and Programmed Nutrition Beef Finisher. The goal was to determine if these shifts in rumen fermentation contribute to the Programmed Nutrition response observed in vivo. This study also analyzes how different levels of α-amylase (Amaize)supplementation impacts feedstuff degradation and utilization in vitro. In vivo experiment used eight steers in a replicated …

Management Plan For Reducing Wolverine (Gulo Gulo) Habitat Fragmentation In Canada: Travel Corridors Between Tonsa Peak And Stuart Knob, Alison Keister

Research Awards

No abstract provided.

Understanding Caribou Population Cycles, Jack R. St. John

Undergraduate Theses, Professional Papers, and Capstone Artifacts

The complex population dynamics of caribou (Rangifer tarandus) were studied to determine the patterns of their population cycles and the processes driving them. It is well established, via previous archaeological research and Indigenous knowledge, that large migrating caribou herds found in and around the tundra at northern latitudes experience population boom and busts roughly every several decades. However, the processes driving the dynamics of these cycles are relatively unknown, which makes managing caribou herds for recreational and subsistence harvests difficult. It has been hypothesized that a combination of intrinsic and extrinsic factors shape these cycles, with density-dependence, predation, …

Relating Habitat Use To Survival Of Oncorhynchus In Rock Creek And The Clark Fork River, Brett D. Traxler

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Westslope Cutthroat Trout Oncorhynchus clarkii lewisi (WCT) is a native trout species of conservation concern in Montana. Both migratory and resident life histories can be found in cutthroat from the same natal stream. Habitat degradation and hybridization with rainbow trout O. mykiss (RBT) have resulted in few genetically pure, migratory WCT populations persisting in large river systems. These WCT conservation populations are occurring more and more as isolated, resident populations in headwater streams. Rock Creek in Western MT has retained a unique population of migratory, non-hybridized WCT, and is of special conservation and ecological interest. As we work to protect …

Adult Female Grizzly Bear (Ursus Arctos Horribillis) Abundance And Distribution In Montana Fish, Wildlife, And Parks Region 2, Emily E. Ruta

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Grizzly bears (Ursus arctos horribilis) are currently listed as threatened under the Endangered Species Act. Their status makes it crucial to understand the population status and trends of grizzly bears in Western Montana. The question we aimed to answer was: How many adult female grizzlies were there in Montana Fish, Wildlife, and Parks (FWP) Region 2 during 2021? To answer this, we conducted an estimate of adult female grizzly bears in Montana Fish, Wildlife and Parks Region 2 in 2021 using photos and confirmed reports. Our study focused on females because they are readily identifiable and are an important indicator …

Comparing Physiological Responses To Hot And Cold Stress In A Cnidarian–Algal Holobiont, Exaiptasia Diaphana, Nicole Capozzi, Eyananda Ahmed, Ezra Curtis, Olivia Grandbois, Dominique Kelly, Kadin Kristjansson, Natalie Morgan, Louis Schlecker, Rachel M. Wright

Other Student Projects

Coral bleaching—the breakdown of the cnidarian–algal symbiosis—is a major cause of reef decline. The sea anemone Exaiptasia diaphana, commonly known as Aiptasia, is used as a model to study cnidarian-algal symbiosis in laboratory settings. Aiptasia can live with or without symbionts, which allows scientists to study the host combined and separate from the influence of the symbionts. Scientists are able to trigger the breakdown of the symbiosis using heat or cold stress. Cold stress is more commonly used to render aposymbiotic Aiptasia because it seems to be less harmful to the host than bleaching under heat stress. Is cold …

A Gene-Based Capture Assay For Surveying Patterns Of Genetic Diversity And Insecticide Resistance In A Worldwide Group Of Invasive Mosquitoes, Matthew L. Aardema, Michael G. Campana, Nicole E. Wagner, Francisco C. Ferreira, Dina M. Fonseca

Department of Biology Faculty Scholarship and Creative Works

Understanding patterns of diversification, genetic exchange, and pesticide resistance in arthropod disease vectors is necessary for effective population management. With the availability of next-generation sequencing technologies, one of the best approaches for surveying such patterns involves the simultaneous genotyping of many samples for a large number of genetic markers. To this end, the targeting of gene sequences of known function can be a cost-effective strategy. One insect group of substantial health concern are the mosquito taxa that make up the Culex pipiens complex. Members of this complex transmit damaging arboviruses and filariae worms to humans, as well as other pathogens …

Three-Dimensional Mesenchymal Stem Cell Laden Scaffold Of Icariin Sustained-Release For Bone Regeneration, Yanbing Liu, Yan Fang

Turkish Journal of Biology

Background/aim: Icariin (ICA)-loaded zein/PLGA nanofiber membrane combined with MSCs was prepared by coaxial electrospinning and bioelectrospraying. Materials and methods: SEM and TEM were used to evaluate the surface morphology and microstructure of the fiber membrane. Ultraviolet spectrophotometry was used to detect drug release. A LIVE/DEAD Viability/Cytotoxicity Kit and fluorescence staining were used to detect cell morphology and activity. Alkaline phosphatase and calcium mineralization deposition were used to evaluate the osteoinductive activity of the scaffold. Dynamic mechanical analysis was used to determine the Young's modulus, maximum load, and maximum elongation of the prepared scaffold. Western blot was used to detect the …

Rnai For Western Corn Rootworm Management: Lessons Learned, Challenges, And Future Directions, Molly Darlington, Jordan D. Reinders, Amit Sethi, Albert L. Lu, Partha Ramaseshadri, Joshua R. Fischer, Chad J. Boeckman, Jay S. Petrick, Jason M. Roper, Kenneth E. Narva, Ana M. Vélez

Department of Entomology: Faculty Publications

The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, is considered one of the most economically important pests of maize (Zea mays L.) in the United States (U.S.) Corn Belt with costs of management and yield losses exceeding USD ~1–2 billion annually. WCR management has proven challenging given the ability of this insect to evolve resistance to multiple management strategies including synthetic insecticides, cultural practices, and plant-incorporated protectants, generating a constant need to develop new management tools. One of the most recent developments is maize expressing double-stranded hairpin RNA structures targeting housekeeping genes, which triggers an RNA interference (RNAi) …

Developing And Evaluating A Pollination Systems Knowledge Assessment In A Multidisciplinary Course, P. Citlally Jimenez, Doug Golick, Brian A. Couch, Jenny Dauer

Department of Entomology: Faculty Publications

Background: Although pollinators play an integral role in human well-being, their continued global decline reflects the need to provide and evaluate general pollinator knowledge to promote their conservation. Enhancing learners’ understanding of the complexity inherent in pollination systems within the science classroom may help them make more informed decisions regarding pollinator conservation actions. By measuring conceptual understanding of pollination systems, science educators can identify learners’ knowledge needs and inform their teaching in science classrooms. Based on previously developed theoretical frameworks describing pollination systems knowledge, we created and evaluated a new instrument to assess pollination systems and conservation actions knowledge. The …

A Stillness In The Desert? Engaging The Public Through An Immersive Exploration Of Southwest Soundscapes, Julian Kilker, Thomas Bjelic

Creative Collaborations

The pandemic highlighted the anthropocentric nature of soundscapes, while the recent popularity of electric cars, quadcopters, and “noise cancellation” earbuds demonstrated how consumer products can rapidly change our awareness of sound. While light pollution is already extensively addressed in scholarly research, popular works such as The End of Night, and public engagement such as The International Dark Sky Association, the complex interplay of sound, natural resources, and public engagement is still emerging, particularly in creative fields.

Two UNLV scholars and artists are collaborating on this project: Julian Kilker, who specializes in visual and emerging technology research, and Tom Bjelic, who …

Assessment Of Digital Imaging Flow Cytometry In Its Application Of Harmful Algal Blooms Monitoring, Melissa Mazzaro

Theses, Dissertations and Culminating Projects

As harmful algal blooms (HABs) are becoming an increasing global threat to the health of people, animals, and aquatic ecosystems, finding ways to efficiently detect and manage blooms is critical. Traditional methods of identifying and enumerating phytoplankton cells involve light microscopy; however, this is a time-consuming and labor-intensive process. Meanwhile, digital imaging flow cytometry is a relatively novel and rapid method of enumerating and identifying particles within phytoplankton samples. Previous studies have documented comparable digital flow cytometry results to microscopy results; however, there are concerns relating to the underestimation of cells and misidentification of particles with their automated classification systems. …

All About The Prairie: Coloring Book Of Plants, Animals, And Insects Native To Iowa Prairies, Brianna Hull

Faculty Book Gallery

A coloring book with drawings of plants, animals, and insects that are native to Iowa. Includes the common and Latin names of the species as well as the Meskwaki names for some. -- Provided by the publisher

Disability In An American Indian Community : Prevalence, Distribution, And The Role Of Polychlorinated Biphenyls, Thoin Farzana Begum

Legacy Theses & Dissertations (2009 - 2024)

The Akwesasne reservation along the St. Lawrence River has experienced significant exposure to several persistent organic pollutants due to rapid industrialization. The Aluminum Company of America, General Motors, and Reynolds Metals operated aluminum foundries that used polychlorinated biphenyls (PCBs) as hydraulic fluids, which contaminated the community environment, the soil, air and water, and community food sources with PCBs. We administered the World Health Organization Disability Assessment Schedule II (WHODAS II) to 119 Akwesasne Mohawk adults residing along the St. Lawrence River in New York. We used exploratory factor analysis to summarize the 36- items comprising the WHODAS II. The 7 …

Inhibition Of Lysine Acetyltransferases Kat 3a/3b And Its Effect On Poliovirus Proliferation, Eduards Norkvests

Legacy Theses & Dissertations (2009 - 2024)

Ribosomes have been traditionally viewed as invariable machinery, but in recent years more and more evidence for their heterogeneity has emerged. Core ribosomal proteins, ribosomal-associated proteins, and post-translational modifications all contribute to the variations found within these crucial subcellular components.In our research, we focused on lysine acetylation – a post translational modification found on many ribosomal proteins. We used a chemical inhibitor of acetyltransferases KAT 3A and KAT 3B to observe the effect that inhibiting acetylation may have in the context of translation. By using poliovirus to shut off conventional cellular translation, we were able to look at a narrow …

Salivary Gland Stromal Heterogeneity And Epithelial Controls, Nicholas L. Moskwa

Legacy Theses & Dissertations (2009 - 2024)

Organogenesis is the process organs go through where cellular communications coordinate all a developing organ needs. What organs need are more cells, in the right place, doing the right job. In the salivary gland, we know that stromal cells are important for organogenesis and that they coordinate the epithelium’s form and functions. However, specific stromal contributions have focused on epithelial quantity and placement. There is less information about how the stroma directs the epithelium towards certain functions. Here we used organoids as a model for understanding what stromal signaling directs epithelial cell fate. We found that stromal cell state is …

Neural Correlates And Neuroanatomy Of Juvenile And Adult Contextual Fear Memory Retention, Natalie Odynocki

Legacy Theses & Dissertations (2009 - 2024)

AbstractFear is an evolutionarily conserved mechanism that allows an organism to discern potential harm and act accordingly by engaging in defensive behaviors. While fear is an adaptive response, dysregulation of fear by means of a traumatic event can lead to psychiatric conditions such as post-traumatic stress disorder (PTSD). Animal research using rodents in Pavlovian context fear conditioning experiments allows for the ability to study the underlying neural circuitry of threat-appropriate and aberrant fear learning and memory that may contribute to PTSD. However, despite reports that women are more than two times more likely to develop PTSD compared to men, the …

Evaluation Of Aquatic Plant Survey Methods For Efficacy In Invasive Species Detection, Izaac Cooper

Legacy Theses & Dissertations (2009 - 2024)

Aquatic invasive plants can often be ecologically devastating to ecosystems where they are introduced. This devastation has been widely apparent in the United States, including many locations in New York State over many decades, following anthropogenic transport of species from their native ranges. Due to the difficulty involved in eradicating these plants once they have become fully established, there is keen interest in strategies for early detection to assist with prevention and monitoring to mitigate future management costs. Invasive species detection research aims to find methods for detecting new invaders more effectively. I evaluated three detection methods for their effectiveness …

Mechanisms By Which Protective Human Outer Surface Protein A Antibodies Block Transmission Of Borrelia Burgdorferi, Amber M. Frye

Legacy Theses & Dissertations (2009 - 2024)

Borrelia burgdorferi (B. burgdorferi) is the causative agent of Lyme disease in the United States and Europe, which remains a major threat to public health. While currently no human Lyme disease vaccine is available, a previously licensed OspA-based vaccine was shown to effectively prevent transmission of B. burgdorferi from ticks to mammalian hosts. Concerning the vaccines mechanism of action, OspA antibodies enter the bloodmeal of a feeding tick and engage with B. burgdorferi producing OspA on their outer surface in a manner that impairs migration of the spirochete to the host; however exact antibody-spirochete interaction is unknown, despite the importance …

Mechanisms Underlying Pre- And Postnatal Development Of The Mouse Vomeronasal Organ, Raghu Ram Katreddi

Legacy Theses & Dissertations (2009 - 2024)

The Vomeronasal organ (VNO) is a specialized olfactory sensory organ located in the ventral region of the nasal cavity in rodents. The vomeronasal epithelium (VNE) of rodents is composed of 2 major types of vomeronasal sensory neurons (VSNs): 1) VSNs distributed in the apical VNE regions that express vomeronasal type-1 receptors (V1Rs) and the G protein subunit Gi2, and 2) VSNs in the basal territories of the VNE that express vomeronasal type-2 receptors (V2Rs) and the G subunit Go. Besides these two neuronal types, VNE also accommodate a third non-neuronal cell type called Sustentacular cells that lie anatomically above apical …

Ab42 Alters Glutamatergic Transmission In The Ca1 Region Of The Mouse Hippocampus, Patrick Harry Wehrle

Legacy Theses & Dissertations (2009 - 2024)

Alzheimer’s disease (AD) is a neurodegenerative disease affecting 4.5 million people in the US, a number expected to increase 3-fold over the next 30 years. One of the hallmarks of AD is the extracellular accumulation of the protein Aß₄₂ throughout in the brain, particularly in limbic structures like the temporal cortex and hippocampus, key regions for learning and memory. Currently available animal models for AD aim to reproduce key genetic traits of the familial variant of the disease, but >90% of AD patients are affected by idiopathic AD. To overcome this potential limitation, we use a different approach to study …

Synthesis Of Oligonucleotides Containing Unnatural Backbone And Regulation Of Crispr Activity Using Inverse Electron Demand Diels-Alder Chemistry, Alyssa Hoy

Legacy Theses & Dissertations (2009 - 2024)

This thesis describes the synthesis of an oligonucleotide containing an unnatural neutralbackbone. The backbone was constructed using bio-orthogonal inverse electron demand Diels- Alder chemistry between trans-cyclooctene (TCO) and tetrazine (Tz). A TCO phosphoramidite was synthesized and attached to solid support for strand propagation. Uridine monomers containing either bis-TCO or bis-Tz were also synthesized. The oligonucleotide strand was formed by sequential ligation of the bis-Tz and bis-TCO monomers. The oligonucleotide was analyzed using mass spectrometry. This thesis also describes the synthesis of sgRNAs containing non-canonical nucleobases, m1A, m6A, s2U and s4U using the ‘split-and-click’ methodology. The synthetic sgRNAs were assembled using …

Trace Elements In Nails And Anemia In Children Living Along The Interoceanic Highway, Madre De Dios, Peru / Narrative Competence And Cognitive Mapping As A Culturally Sustaining Pedagogy In The Education Of Emergent Bilinguals, Tia Marks

Legacy Theses & Dissertations (2009 - 2024)

Anthropogenic changes in the Peruvian Amazon, including deforestation, highway development, agriculture, and artisanal and small-scale gold mining (ASGM), have increased community concern about potential exposures toxic trace elements (TTE) including arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb). Such exposures can lead to detrimental health effects in children, such as developmental delays and anemia. The overarching goal of my dissertation was to understand exposure to both toxic and essential (manganese (Mn), selenium (Se), and zinc (Zn)) trace elements, anemia prevalence, and the associations between hemoglobin (Hb) levels and trace elements. To do this, I leveraged existing data from a …

Genetic Regulation Within Cellular Stress Response Pathways, Jhos M. Dufflart

Legacy Theses & Dissertations (2009 - 2024)

Cellular stress is something that a cell deals with on a regular basis. Fortunately, there are several different mechanisms that are set in place in order to deal with them. Depending on the stress present in the cell there will be different stress response pathways that are activated in order to mitigate the stress or initiate cellular death mechanisms. Transcription factors (TFs) are key components within these pathways, and this will be the focus of this thesis. TFs within mammalian stress response pathways are tasked with the essential regulation of multiple genes within these pathways and are oftentimes linked with …

Exploring The Roles Of Stress, Codon Usage, And Rna Modifications In Myotonic Dystrophy Type 1, Afrooz Golestanian

Legacy Theses & Dissertations (2009 - 2024)

Myotonic dystrophy (DM), the most common form of muscular dystrophy, is a neuromuscular disease caused by microsatellite repeat expansions. It can represent a multi-systemic autosomal dominant disease with DM1 and DM2 subtypes. A cytosine-thymine-guanine (CTG) triplet repeat in the 3’ untranslated region (3’UTR) of myotonic dystrophy protein kinase (DMPK) gene causes DM1 disease, which leads to the production of a longer, abnormal and toxic mRNA. The toxic DMPK mRNA sequester the splicing proteins such as Muscle blind-like (MBNL) and rbFOX which leads to gene expression alteration. Repeat associated non-AUG (RAN) translation also occurs in DM1. Mitochondrial dysregulation has also been …

Disability In An American Indian Community : Prevalence, Distribution, And The Role Of Polychlorinated Biphenyls, Thoin F. Begum

Legacy Theses & Dissertations (2009 - 2024)

Phthalates have been implicated as reproductive toxicants in animal models and in human populations. This study examined associations between potential exposure sources and urinary phthalate concentrations among couples undergoing infertility treatment. Women (n=56) and their male partners (n=43) undergoing in vitro fertilization (IVF) were enrolled in a prospective cohort investigation of environmental chemicals and IVF outcomes at an academic medical center. On the day of oocyte retrieval, participants provided urine samples and completed questionnaires detailing use of personal care products (PCPs), and consumption of medications, foods, and beverages in the preceding 24-hours. Urine was analyzed for MEP, MBP, MPP, MHxP, …