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Full-Text Articles in Life Sciences

Life On The Edge: Insights Into The Neural And Behavioral Algorithms Of Plume Tracking, Andrew Siliciano Jan 2023

Life On The Edge: Insights Into The Neural And Behavioral Algorithms Of Plume Tracking, Andrew Siliciano

Student Theses and Dissertations

Animals use turbulent odor plumes as chemical beacons to navigate long distances. What are the neural and behavioral algorithms that underlie such a navigational feat? While plume navigation has been conventionally described as a simple sensory reflex, animals may instead rely on their memories of past plume encounters and current assessment of the wind direction to pursue a dynamic odor source. Differentiating between these strategies has been challenging due to the fact that plumes are invisible and spatially complex, precluding an understanding of the exact sensory experience of an animal. We have been leveraging the concise architecture of the Drosophila …

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Dissecting Host-Viral Interactons Through Focused Or Unbiased High-Throughput Genetic Approaches, Daniel Poston Jan 2023

Dissecting Host-Viral Interactons Through Focused Or Unbiased High-Throughput Genetic Approaches, Daniel Poston

Student Theses and Dissertations

In the world around us, viruses surround and vastly outnumber us. Indeed, there are roughly 1 sextillion—or one thousand million million million—times as many viral particles as humans on earth (1). While most of these viruses do not cause disease in humans, those that do present a grave and increasing threat to human health. Fundamental studies in host-viral interactions are thus critical to further our understanding of the parameters of viral infection and elucidate potential new treatments. Since, as obligate intracellular parasites, viruses rely on host resources at every step of the viral lifecycle, in-depth knowledge of how viruses hijack …

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Structural And Functional Analysis Of Substrate Recognition And Inhibition Of The Multidrug Transporters Mrp1 And Mrp2, Harlan Linver Pietz Jan 2023

Structural And Functional Analysis Of Substrate Recognition And Inhibition Of The Multidrug Transporters Mrp1 And Mrp2, Harlan Linver Pietz

Student Theses and Dissertations

Neuroblastoma is the most common extracranial tumor of young children, and the five-year overall survival of children with high-risk disease is less than 50%. Overexpression of multidrug resistance protein 1 (MRP1), a plasma membrane ATP-binding cassette (ABC) transporter, is associated with high-risk neuroblastoma. While it is known that MRP1 transports multiple neuroblastoma chemotherapeutic agents out of the cell in a glutathione (GSH)-dependent manner, the mechanism of GSH-dependent MRP1 substrate transport has previously not been understood. Additionally, over the past three decades, multiple small-molecule inhibitors of MRP1 transport have also been identified, with the activity of several inhibitors also determined to …

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Antibody-Effector Functions In Antiviral Response, Kevin Shuolong Kao Jan 2023

Antibody-Effector Functions In Antiviral Response, Kevin Shuolong Kao

Student Theses and Dissertations

Antibodies are a fundamental component of the adaptive arm of the immune system. Interactions of the antibody's fragment crystallizable (Fc) domain with Fc receptors (FcR) on effector leukocytes is essential for proper immunological function and bridges the humoral with the cellular components of immunity. While the Fc domain of immunoglobulin G (IgG) has historically been considered to be relatively constant, recent studies have demonstrated that in conjunction with IgG subclasses, the single conserved N-linked glycan present on the CH2 domain imparts a considerable amount of heterogeneity in the molecule. Given the stepwise construction of this N-glycan structures, families of highly …

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Structures, Functions, And Druggability Of The Sars-Cov-2 Replication–Transcription Complex, Brandon F. Malone Jan 2023

Structures, Functions, And Druggability Of The Sars-Cov-2 Replication–Transcription Complex, Brandon F. Malone

Student Theses and Dissertations

Since its emergence in late 2019, the COVID-19 pandemic continues to devastate communities worldwide. Despite the successes in both identifying new therapeutics and immunization strategies that have alleviated the toll on livelihoods, the threat of novel coronavirus (CoV) variants triggering future pandemics necessitates research into the lifecycle of the causative agent, SARS-CoV-2, and more broadly related CoVs. An essential aspect of viral propagation is the replication process in which viral enzymes orchestrate the production of nascent viral RNA genomes. CoV RNA synthesis is mediated by the RNA-dependent RNA polymerase (RdRp) which requires a coterie of viral nucleic acid-metabolizing enzymes to …

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Replaying Life's Tape With Intraclonal Germinal Center Evolution, Tatsuya Araki Jan 2023

Replaying Life's Tape With Intraclonal Germinal Center Evolution, Tatsuya Araki

Student Theses and Dissertations

Because high-affinity antibodies produced by germinal centers (GCs) are critical in protecting against the ever-increasing array of pathogens, understanding how GC response allows our immune system to recognize a variety of pathogens and develop specific and effective immunity against each pathogen encounters are important. We gained insight into how GCs modulate clonal diversity in recent years, including a discovery that individual B cells clones can occasionally undergo "clonal bursts" that eliminate clonal diversity through massive proliferation. However, it remains unclear what are the factors driving such bursts, or whether GCs respond reproducibly to similar magnitude increases in affinity, mainly because …

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Neotelomere Formation By Telomerase In Human Cells, Charles Gunnar Kinzig Jan 2023

Neotelomere Formation By Telomerase In Human Cells, Charles Gunnar Kinzig

Student Theses and Dissertations

Telomeres define and protect the ends of linear chromosomes. Genome stability requires that cells differentiate telomeres from DNA double-strand breaks (DSBs), which humans accomplish with the shelterin complex. The reverse transcriptase telomerase counteracts the shortening of telomeres that occurs with cell division due to incomplete DNA replication and nucleolytic resection. During human development, the expression of the reverse transcriptase component of telomerase (TERT) is restricted to the germ line and select stem cell pools, causing telomeres to shorten in most somatic cells. After a certain number of divisions, one or a few telomeres become too short to adequately suppress DNA …

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Cortical Control Of Naturalistic Facial Expression Production In Primates, Geena Rose Ianni Jan 2023

Cortical Control Of Naturalistic Facial Expression Production In Primates, Geena Rose Ianni

Student Theses and Dissertations

Facial expressions constitute a fundamental class of social communication signals in primates. Nonverbal expressions shared between individuals can instantly and effortlessly communicate endogenous affective state, the valence of external stimuli, as well as more complex concepts such as intentions, social rank, and receptivity to future social interactions. All of this information is transmitted through the fine, dynamic arrangement of dozens of small facial expression muscles. Commiserate with their importance, the muscles of facial expression are under direct cortical control from descending projections to the facial nucleus. These direct corticomotoneuron projections are unique to primates and originate in multiple distinct cortical …

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Deep Molecular Characterization Of Human Cortical Cell-Types, Christina Pressl Jan 2023

Deep Molecular Characterization Of Human Cortical Cell-Types, Christina Pressl

Student Theses and Dissertations

Human cortical cytoarchitecture is as beautiful as it is complex. Harboring dozens of morphologically, functionally, and molecularly distinct cell-types, the neocortex is organized into cytoarchitectonically and functionally diverse regions. In concert, the diverse cell-types that are found within the diverse cortical regions build the center of all higher cognitive functions, including but not limited to sensory processing, instruction and execution of motor movements, abstract thinking, perception, as well as speech processing and production. Over the past decades, detailed knowledge on the molecular characteristics of cortical cell-types has been obtained from genetically engineered animal models. These deep insights into the molecular …

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Life On A Ball: Multi-Week Tethered Behavior In Drosophila, Jazz Weisman Jan 2023

Life On A Ball: Multi-Week Tethered Behavior In Drosophila, Jazz Weisman

Student Theses and Dissertations

By studying head-fixed or rigidly tethered animals, neuroscientists have been able to make high-resolution neurophysiological and behavioral measurements during naturalistic tasks. Tethered paradigms have a particularly rich history in the study of insect behavior and in this thesis I describe technology that extends by one-hundred fold—from hours to weeks—the timescale over which individual Drosophila can be routinely studied while tethered in place. Specifically, I designed and constructed a new experimental rig that allows a rigidly tethered fly to live for at least two weeks within a virtual reality environment. The fly stands (and is free to walk) on an airsupported …

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Bioorthogonal Tethering Of Drug Fragments To Engineered G Protein-Coupled Receptors, Jordan M. Mattheisen Jan 2023

Bioorthogonal Tethering Of Drug Fragments To Engineered G Protein-Coupled Receptors, Jordan M. Mattheisen

Student Theses and Dissertations

G protein-coupled receptors (GPCRs) modulate diverse cellular signaling pathways and are important drug targets. Despite the availability of high-resolution structures for nearly 100 discrete GPCRs in complex with various ligands, discovering allosteric drugs that can modulate receptor signaling remains challenging. In principle, allosteric ligands have certain advantages because they bind to pockets on the receptor that do not directly impact the orthosteric site for agonist ligands, but still tune downstream signaling pathways. But identifying and validating allosteric ligands remains difficult partly due to the dynamic nature of GPCRs in native membranes. Of the more than 3700 distinct FDA-approved drugs, there …

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Development Of Improved Genetic Methods For Enterococcus Faecium, Victor Chen Jan 2023

Development Of Improved Genetic Methods For Enterococcus Faecium, Victor Chen

Student Theses and Dissertations

Enterococcus faecium is a ubiquitous Gram-positive bacterium that has been recovered from the environment, food, and microbiota of mammals. Enterococcus faecium is widely recognized as an emerging public health threat with the rise of drug resistance and nosocomial infections. Antibiotic usage has afforded antibiotic-resistant and pathogenic isolates from livestock and humans. Nevertheless, commensal Enterococcus strains possess beneficial health functions in mammals to upregulate host immunity and prevent microbial infections. However, the dissection of E. faecium functions and mechanisms has been restricted by inefficient genetic methods. Current genetic engineering methods in E. faecium still require passive homologous recombination from plasmid DNA. …

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The Search For Regulatory Mutations In Gitelman Syndrome, Renan Eduardo Aparicio Jan 2023

The Search For Regulatory Mutations In Gitelman Syndrome, Renan Eduardo Aparicio

Student Theses and Dissertations

The development of whole exome and whole genome sequencing technologies has allowed geneticists to gradually uncover a wide spectrum of rare, deleterious mutations with large effect sizes, which are responsible for Mendelian diseases. Roughly 70% of human genes are single copy and have orthologs across the vertebrate lineage, suggesting that they are under purifying selection. This suggests that at least 10,000 genes will have Mendelian phenotypes when mutated but have yet to be discovered1. Exhaustive research efforts have been directed at finely categorizing the coding, and more recently noncoding, genome. The actual number of large effect noncoding mutations, and of …

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A Chemical-Genetic Map Of Drug Resistance In Mycobacterium Tuberculosis, Nicholas Poulton Jan 2023

A Chemical-Genetic Map Of Drug Resistance In Mycobacterium Tuberculosis, Nicholas Poulton

Student Theses and Dissertations

Tuberculosis (TB) is the leading cause of death from any single infectious disease, killing over 1.5 million people each year. Treatment of TB is extraordinarily difficult, requiring at least 6 months of combination antibiotic therapy to cure patients. Even with this prolonged treatment, 5 to 10% of patients are not fully cured and experience disease relapse. Mycobacterium tuberculosis (Mtb), the causative agent of TB, is intrinsically resistant to most antibiotics and can acquire an additional level of antibiotic resistance through specific chromosomal mutations. A better understanding of intrinsic and acquired drug resistance in Mtb is essential to develop faster treatments …

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Multiplexed Mapping Of The Interactome Of G Protein-Coupled Receptors And Receptor Activity-Modifying Proteins, Ilana Beth Kotliar Jan 2023

Multiplexed Mapping Of The Interactome Of G Protein-Coupled Receptors And Receptor Activity-Modifying Proteins, Ilana Beth Kotliar

Student Theses and Dissertations

Receptor activity-modifying proteins (RAMPs) have emerged as modulators of many aspects of G protein-coupled receptor (GPCR) biology and pharmacology. The RAMP family was discovered more than two decades ago and GPCR-RAMP interactions and their functional consequences on receptor trafficking and ligand selectivity have been documented for several GPCRs, mostly belonging to the secretin family. However, the pervasiveness of GPCR-RAMP interactions and the mechanisms of their effects are not well understood. Recent bioinformatics and experimental studies suggest that GPCR-RAMP interactions might be much more widespread than previously anticipated. However, potential direct interactions among the three known RAMPs (RAMP1, RAMP2 and RAMP3) …

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The Internal Orchestration Of A Courtship Ritual In Drosophila, Tom Anton Hindmarsh Sten Jan 2023

The Internal Orchestration Of A Courtship Ritual In Drosophila, Tom Anton Hindmarsh Sten

Student Theses and Dissertations

The diversity of behaviors exhibited by animals is astounding. Even within a species, members constantly select between a myriad of ways to interact with their environment, ranging from foraging to fighting. Yet, why an individual behaves as it does in each moment of time typically remains nebulous to us as observers. In this thesis, I explore the possibility that these seemingly idiosyncratic behavioral decisions can be understood by accessing the hidden internal motivations that spur an animal to do one thing in lieu of another. By leveraging the compact brain architecture and rich social behaviors of the fruit fly Drosophila …

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On The High-Dimensional Geometry Of Neuronal Population Dynamics, Jason M. Manley Jan 2023

On The High-Dimensional Geometry Of Neuronal Population Dynamics, Jason M. Manley

Student Theses and Dissertations

The brain's remarkable computational properties arise from the collective activity of up to billions of densely interconnected neurons. Neurotechnologies to simultaneously measure the activity of many neurons have been steadily developed over the past decades, with mesoscopic optical imaging now reaching tens of thousands or more neurons in a single experiment. These data have only opened up additional fundamental questions on how the neuronal population code enables robust yet flexible computation from the highly variable activities of single neurons. Here, we utilized large-scale optical imaging to investigate how neuronal population dynamics are structured across diverse brain regions during spontaneous and …

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New Insights Into The Roles Of Fan1 Nuclease In Genome Maintenance And Disease, Christian S. Saffran Jan 2023

New Insights Into The Roles Of Fan1 Nuclease In Genome Maintenance And Disease, Christian S. Saffran

Student Theses and Dissertations

Exogenous and endogenous insults to genomic integrity are an existential threat to every species, and therefore robust DNA damage repair mechanisms have evolved to protect against genotoxic threats. FANCD2 and FANCI associated nuclease 1 (FAN1) has roles in protection against two major threats to genomic stability: DNA interstrand crosslinks (ICLs), and the expansion of trinucleotide repeats. ICLs are highly deleterious lesions that disrupt replication, are destructive to dividing cells, and are extremely toxic to the hematopoietic system. The replication-dependent Fanconi anemia (FA) pathway defends against ICL toxicity in rapidly dividing cells. However, while it is critical for protecting the bone …

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Sex Differences And The Evolution Of Gene Expression, Samuel Khodursky Jan 2023

Sex Differences And The Evolution Of Gene Expression, Samuel Khodursky

Student Theses and Dissertations

Phenotypic sex differences are essential byproducts and drivers of evolution in sexually reproducing species. Knowing how sex differences arise and how they influence evolution is central to our understanding of evolution. Although many facets of sex differences have been explored, many remain unknown. Here I focus on sex differences and the evolution of gene expression in three parts. First, I examine the evolutionary properties of genes with sex differences in mean expression levels in the Drosophila brain – a surprisingly understudied organ in this context. Second, I identify and characterize genes with sex differences in gene expression variability in human …

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Converting An Allocentric Goal Direction Into An Egocentric Steering Signal In Drosophila, Peter Mussells Pires Jan 2023

Converting An Allocentric Goal Direction Into An Egocentric Steering Signal In Drosophila, Peter Mussells Pires

Student Theses and Dissertations

Neuronal signals relevant for spatial navigation have been described in many species, however, a circuit-level understanding of how such signals interact to guide behaviour is lacking. In this thesis, I characterize a neuronal circuit in the Drosophila central complex that compares internally generated estimates of the fly's heading and goal angles––both encoded in world-centred, or allocentric, coordinates––to generate a body-centred, or egocentric, steering signal. Past work has argued that the activity of EPG cells, or "compass neurons", represents the fly's moment-to-moment angular orientation, or heading angle, during navigation. An animal's heading angle, however, is not always aligned with its goal …

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Native Seed Germination Trials At The Rae Selling Berry Seed Bank, Garbiel E. Campbell, Roxy Olsson, April Hersey, Stephanie Meikle, Kris Freitag Jan 2023

Native Seed Germination Trials At The Rae Selling Berry Seed Bank, Garbiel E. Campbell, Roxy Olsson, April Hersey, Stephanie Meikle, Kris Freitag

Rae Selling Berry Seed Bank and Plant Conservation Program

This presentation is a summary of germination trials on seeds native to the Pacific Northwest.

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Application Of The Fine Sediment Biotic Index To Three Drain Tiled And Ditched Agricultural Systems In Southern Minnesota, Bailey Sanders Jan 2023

Application Of The Fine Sediment Biotic Index To Three Drain Tiled And Ditched Agricultural Systems In Southern Minnesota, Bailey Sanders

All Graduate Theses, Dissertations, and Other Capstone Projects

Artificial drainage is a common agricultural management technique in the United States used to remove excess water from poorly drained soils. Approximately 22.48 million hectares of crop land are drain-tiled in the United States, providing long-term economic benefits to farmers. However, artificial drainage increases sediment transport in agricultural watersheds, which can degrade aquatic systems, destroy habitats, and limit biological diversity. Biotic indices based on benthic macroinvertebrates are commonly used to assess surface water quality, but recent studies show potential in developing sediment biotic indices using benthic macroinvertebrates to estimate fine sediment in streams. The objective of this study was to …

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Examination Of Food Allergy Accommodations, Barriers, Improvements, And Food Service On College Campus Dining Services, Krista Stawarz Jan 2023

Examination Of Food Allergy Accommodations, Barriers, Improvements, And Food Service On College Campus Dining Services, Krista Stawarz

Graduate Research Theses & Dissertations

Background: Food allergies are an increasingly prevalent medical concern in college age students who live on campus and rely on campus dining services to accommodate them. The purpose of this study was to identify barriers along with current dining accommodation services that were available to students with food allergies at Northern Illinois University (NIU).Methods: Twenty-six students who had at least one food allergy and utilized the dining facilities were recruited to complete a cross-sectional survey. Descriptive statistics and thematic analysis were used in this study. Results: The two most common barriers faced were lack of information and communication. Additional barriers …

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Evaluation Of Plaster Creek Stewards: Results And Recommendations From Surveys, Interviews, And Education Event Feedback Forms, Laura Luchies, Jax Heil, Taylor E. Hartson Jan 2023

Evaluation Of Plaster Creek Stewards: Results And Recommendations From Surveys, Interviews, And Education Event Feedback Forms, Laura Luchies, Jax Heil, Taylor E. Hartson

Watershed Reports

No abstract provided.

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Seasonal Starch Allocation In Starry Stonewort (Nitellopsis Obtusa) Harvested From Lake Koronis, Mn, And Development Of Non-Chemical Management Recommendations, Alyssa M. Haram Jan 2023

Seasonal Starch Allocation In Starry Stonewort (Nitellopsis Obtusa) Harvested From Lake Koronis, Mn, And Development Of Non-Chemical Management Recommendations, Alyssa M. Haram

All Graduate Theses, Dissertations, and Other Capstone Projects

Starry stonewort (Nitellopsis obtusa) (Desvaux in Loiseleur) J. Groves is an invasive macro alga that can take over entire water columns and outcompete native species. Previous research has quantified seasonal life history and phenology but there is no research quantifying carbohydrate allocation which was the aim for Chapter II. Management efforts to control Nitellopsis obtusa have been limited to stressing the thalli and have not been able to directly target the reproductive bulbils on larger scales. Smaller scale efforts such as the use of hand pulling can be used but hand pulling is not realistic for larger infestations. Chapter III …

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Effect Of Initial Infestation Of Zebra Mussels On Freshwater Drum Diets In Red Lake, Mn, Marissa M. Pribyl Jan 2023

Effect Of Initial Infestation Of Zebra Mussels On Freshwater Drum Diets In Red Lake, Mn, Marissa M. Pribyl

Journal of Earth and Life Science

Zebra mussel Dreissena polymorpha veligers were first found in the Red Lake system in Beltrami County in 2017, however no adult zebra mussels have been documented. When zebra mussels first invade a system, fish often switch their prey use to this new abundant resource. Freshwater drum Aplodinotus grunniens is one of these fish species known to consume physidae and bivalves, including zebra mussels, using pharyngeal teeth, the molar-like grinders in the back of their throats. This research aims to identify any presence of adult zebra mussels in the system and determine freshwater drum diet composition and feeding patterns by analyzing …

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Investigation Of A Recent Landslide In Fort Smith, Arkansas, D. Mayo, M.J. Thomas, A. Burns, J. Pruitt, P. Karr Jan 2023

Investigation Of A Recent Landslide In Fort Smith, Arkansas, D. Mayo, M.J. Thomas, A. Burns, J. Pruitt, P. Karr

Journal of the Arkansas Academy of Science

A morphologically youthful slope failure, herein referred to as the Landfill Landslide, was identified in a remote section of the City of Fort Smith Landfill, and permission was obtained to investigate. The slide on a deforested, NW-facing 27% slope beneath a linear head scarp about 200 meters long. One end of the head scarp curves abruptly downhill and transforms into a distinct lateral scarp greater than 100 meters long. The surface of the slide is about 24,000 m2 (6 acres) in area and is easily distinguished from adjacent intact slopes by its hummocky morphology and transverse ridges and valleys. The …

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Determination Of Fatty Acid Concentrations In Various Strains Of Freshwater Green Picoplankton Algae (Class Eustigmatophyceae), P. Ashcraft, R. Jacks, B. Martinez, J. Rodriguez, A.B. Burns, A. Gurnsey, L. Taylor, A. Teague, J. Totty, V.L. Fox, A. Williams Jan 2023

Determination Of Fatty Acid Concentrations In Various Strains Of Freshwater Green Picoplankton Algae (Class Eustigmatophyceae), P. Ashcraft, R. Jacks, B. Martinez, J. Rodriguez, A.B. Burns, A. Gurnsey, L. Taylor, A. Teague, J. Totty, V.L. Fox, A. Williams

Journal of the Arkansas Academy of Science

Algae are of scientific and commercial interest due to their ease of culture and high fatty acid content. The extracted fatty acids from these phytoplankton may potentially be used as an additional test for phylogenetic classification of new algal strains (Tonon et al. 2002), as well as in a supplement for human consumption and producing next-generation biofuels. Of interest is the fatty acid content contained within various algal isolates within the class Eustigmatophyceae. Algal strains were collected and isolated from locations in Lake Chicot in Arkansas, Tower Pond and Lake Itasca at Itasca State Park in Minnesota, and Thayer Lake …

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Journal Of The Arkansas Academy Of Science Volume 77, Academy Editors Jan 2023

Journal Of The Arkansas Academy Of Science Volume 77, Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

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Determining Mating Type And Species Of A Natural Isolate Of Dictyostelium Using Molecular Techniques And Sexual Crosses, S.N. Baviskar, C. Catron, H. Jenkins, M. Smith Jan 2023

Determining Mating Type And Species Of A Natural Isolate Of Dictyostelium Using Molecular Techniques And Sexual Crosses, S.N. Baviskar, C. Catron, H. Jenkins, M. Smith

Journal of the Arkansas Academy of Science

Cellular slime molds, Dictyostelium, are bactivorous, soil-dwelling amoebae. When food is available, cells reproduce asexually by binary fission. Under certain environmental conditions, such as darkness and humidity, Dictyostelium reproduces sexually. The sexual cycle is uniquely social and has unusual features. First, sexual reproduction in most eukaryotes usually involves fusion of two gametes. But, in Dictyostelium, triparental inheritance is observed (Bloomfield et al. 2019), in which gamete fusion involves more than two gametes. Second, most eukaryotic species have two sexes or mating types, but Dictyostelium species are known to have more than two mating types. Even though Dictyostelium species show variations …

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