Organismal Biological Physiology Commons^™

Observing Antibiotic Resistance In Bacterial Co-Cultures Under Simulated Microgravity, Tyler Jenkins, Marina Vaden

Discovery Day - Daytona Beach

Bacteria grow in complex natural environments with multiple factors affecting their growth, metabolism, and physiology. While astronauts are still preparing to travel to Mars, scientists must learn how to simulate a more realistic Martian environment. While a small volume of publications investigates the independent effects of microgravity or Martian regolith on microorganisms (Liao et al., 2025; Allen et al., 2022; Naz et al., 2023; Duri et al., 2025), to our knowledge no current experiments exist on the joint effects of microgravity and Martian simulant on a co-culture. This experiment aims to investigate the effect of a microgravity analog on the …

Marine Heatwaves And Fish Reproduction: Endocrine Responses In The Eurythermal Sheepshead Minnow (Cyprinodon Variegatus), Isabel Villafuerte

Master's Theses

Marine heatwaves associated with climate change are increasing in frequency and severity, posing significant threats to fish populations in shallow habitats such as estuaries and salt marshes. Because temperature is a primary regulator of fish reproduction, understanding how heatwaves affect reproductive physiology is critical for anticipating the biological consequences of ongoing climate change for coastal fishes. Here we examined how simulated heatwave conditions affect the reproductive hypothalamic-pituitary-gonadal (HPG) endocrine axis in the estuarine sheepshead minnow (Cyprinodon variegatus), a eurythermal fish well suited to studying thermal stress responses in estuarine environments. Adult sheepshead minnows acclimated to a daily oscillating …

Degradation And Metabolic Analysis Of Synthesized Quorum-Sensing Signals By The Model Eukaryote Chlamydomonas Reinhardtii, Adam Josef Bach

Theses and Dissertations

Bacterial organisms can “talk” with one another on a colony-wide scale using a communication system known as quorum-sensing (QS) via chemical signals. These signals are produced at a basal rate throughout the life of the bacteria and are classified as autoinducers, which diffuse across the cell membrane. Once the critical concentration is reached, they begin to diffuse back into the cell and initiate a phenotypic change. As these signals exist outside the membrane of their producer, they are also accessible to other organisms. It has already been noted that some plant species uptake these compounds through their roots and break …

Imidacloprid Effects On The Survival And Cutaneous Microbiome Of Northern Leopard Frogs, Evelyn Margaret Osterloo

Honors Thesis

Amphibians are experiencing population declines due to habitat loss, climate change, and diseases, particularly chytridiomycosis caused by the fungus Batrachochytrium dendrobatidis. Protection from this fungal infection stems from the cutaneous microbiome. Pesticides have been shown to affect amphibians in a variety of ways, including reducing survival, locomotor performance, and accumulation in body tissues. Pesticides may also lead to changes in the cutaneous microbiome affecting amphibians who rely on these organisms as an anti-Bd defense mechanism. To investigate the effect of imidacloprid, a neonicotinoid insecticide, Northern Leopard frogs (Lithobates pipiens) were subjected to sublethal concentrations (control = …

Depemokimab: A Twice Yearly Anti-Il 5 Biologic For Chronic Rhinosinusitis With Nasal Polyps (Crswnp) - A Narrative Review, Marn Joon Park, Joseph K. Han, Kent K. Lam

Department of Otolaryngology (ENT) Faculty Publications

Depemokimab is a monoclonal antibody that targets interleukin-5 with enhanced binding affinity and an extended terminal elimination half‑life of 6-8 weeks. The unique pharmacodynamic features of depemokimab enable sustained suppression of type 2 inflammation with twice‑yearly subcutaneous dosing. This narrative review provides details of depemokimab's molecular profile, pharmacokinetics, and pharmacodynamics and results regarding the clinical efficacy and safety of depemokimab from recently published Phase 3 clinical trials for the treatment of chronic rhinosinusitis with nasal polyposis (CRSwNP). In 528 severe adult CRSwNP patients (ANCHOR‑1/‑2 trials), depemokimab achieved Δ total endoscopic nasal polyp score by -0.70 (p <  .001) and Δ nasal obstruction verbal response scale by -0.24 (p = .003) at week 52, compared to placebo. Twice‑yearly 100 mg depemokimab provides durable eosinophil suppression and with a safety profile comparable to placebo in Phase 3 trials for CRSwNP. Future work should refine biomarkers and assess comparative cost‑effectiveness and long‑term adherence, safety, and effectiveness.

The Impact Of Maternal Age On The Expression Of Transgenerational Plasticity In Daphnia Pulicaria, Calvin Nguyen

2025 Spring Honors Capstone Projects - Archive

Transgenerational plasticity refers to heritable, non-genetic changes in phenotype that persist across multiple generations and can enhance offspring survivability in variable environments. In Daphnia, increasing maternal age has been associated with maladaptive plasticity. To investigate this relationship, six clones were collected from two Wisconsin lakes and acclimated to laboratory conditions through a common garden rearing process. For each clone, ten replicates were generated and evenly divided between young (clutches 2–4) and old (clutches 5–8) maternal age groups. Offspring were exposed to three dietary treatments for three experimental generations: one fed only green algae, one fed only cyanobacteria (a nutritionally …

Investigating The Effects Of Prenatal E-Cigarette Exposure On Postnatal Liver Histology, Emma Mcclellan

College of Arts & Sciences Senior Theses

The electronic cigarette (e-cigarette) entered the American market in the mid-2000s and quickly became popular. This product poses a significant threat to youth with 1.63 million students reporting use in 2024. Adverse health effects to different organs are well known. The liver is less studied, and despite its role in detoxification of e-cigarette chemicals, is a target of injury. Unlike the known effects of cigarettes and nicotine on the liver from adult or prenatal exposure, effects of prenatal exposure to e-cigarettes on liver remain to be defined. The current study investigated the effects of prenatal exposure of e-cigarettes on liver …

Genetic Analysis Of Methionine Restriction-Associated Mitochondrial Unfolded Protein Response Signaling., Josh D. Dodge

Biology Dissertations - Archive

The lifespan of an organism is dictated by various genetic and environmental factors. One such determinant is the health of mitochondria which are organelles that mediate various critical cell functions including a significant role in generating the vast supply of cellular energy. Indeed, the gradual decline of mitochondrial function is believed to be a hallmark and possible cause of aging. Paradoxically, mild mitochondrial dysfunction early in life extends lifespan in various model organisms. Cells use diverse approaches to promote mitochondrial homeostasis, including the transcriptional reprogramming of cells by mitochondrial unfolded protein response (UPRmt) to mitigate mitochondrial stress. Consistently, UPRmt activation …

Assessing The Role Of Daily Thermal Fluctuations In The Performance Of Mitochondrial Energy Transduction Of The Centrarchid, Lepomis Cyanellus, Grayson Hofmann

Masters Theses

Freshwater systems are affected by current climate extremes, forcing species found in these systems to withstand drastic changes in temperature. Temperature changes affect these organisms by altering their metabolic rate and energy balance. Increases in temperature can lead to an increase in oxygen consumption, which ultimately increases the need for more energy production. Mitochondrial energy transduction of green sunfish (Lepomis cyanellus) and many other fish species after a thermal insult, has hardly been explored. This study complements the limited research available on mitochondrial function in similar species, as they ignore the possibility of consecutive thermal events, which are …

Development Of A Proposed Selective Medium For The Isolation And Differentiation Of P. Sordellii, Dimyana Bottros

Honors Undergraduate Theses

Clostridium, a genus of anaerobic, spore-forming bacteria, includes clinically and ecologically significant species like Clostridium difficile and Paeniclostridium sordellii. C. difficile causes antibiotic-associated colitis, while P. sordellii is linked to fatal infections and spontaneous abortions. Recent studies found both species in marine sediments, suggesting their role in environmental and wildlife health disturbances, including the 2013 mass mortality of over 300 manatees in the Indian River Lagoon. However, isolating and differentiating P. sordellii is challenging due to the lack of selective media optimized for its growth. This thesis proposes a novel selective medium tailored to P. sordellii’s physiological …

The Physiological Significance Of Nitric Oxide Synthase In Staphylococci, Ryan M. Singh

Theses & Dissertations

Staphylococci, particularly Staphylococcus epidermidis, are common causes of implant-associated infections that may result in notable morbidity and mortality. One of the ways the innate immune system attempts to combat these invading pathogens is via the respiratory burst, in which free radical species such as nitric oxide (NO^•), toxic to bacterial respiration, are released in large quantities. Despite the toxicity of NO^•, some bacteria, including staphylococci, encode an endogenous bacterial nitric oxide synthase (bNOS), whose physiological role has been unclear until now. In this dissertation, we demonstrate that S. epidermidis is able to overcome the toxicity …

Growth Of Methanogens On Kaolinite, A Clay That Has Been Identified On Mars, Hailey Littrell

Biological Sciences Undergraduate Honors Theses

Methanogens have been studied as a model for life on Mars for 28 years now in the Kral lab. The discovery of methane in the Martian atmosphere by ground-based and orbital observations as well as Curiosity Rover (Formisano, V. et al., Krasnopolsky, V.A. et al., Mumma, M.J. et al.) has added relevance to these types of studies. Methanogens were chosen due to their ability to live in harsh environments, very similar to the Martian terrain. In addition to methane in the atmosphere, phyllosilicate clays have also been identified. One of those clays is kaolinite. Kaolinite has been found to not …

Genome-Scale Metabolic Modeling Of Chitin-Degrading Microbial Systems, Aimee Kristin Kessell

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

As a major component of fungal cell walls and exoskeletons of invertebrates, chitin is widespread in soils, constituting the second most abundant biopolymer in nature. Composed of N-acetyl-D-glucosamine chains, it serves as a vital source of nutrients, including both carbon and nitrogen, for the growth of microorganisms. A solid understanding of the microbial degradation of chitin is critical for predicting their impacts on biogeochemical cycling in soil ecosystems. Organisms that degrade biopolymers (degraders) produce energetically expensive extracellular enzymes to break down complex organic carbons into simpler labile forms that are sharable with other species, including those that do not contribute …

Investigation Of L-Serine Synthesis And Transport As Stabilizing Feedback Mechanisms Within The Tsetse-Wigglesworthia Symbiosis, Ryan Phillips

Graduate Theses, Dissertations, and Problem Reports (ETD)

Tsetse flies (Glossina morsitans), which are the obligate vectors of Old-World trypanosomes (Trypanosoma spp.) that cause African trypanosomiasis, have a bacteriome that houses the intracellular endosymbiont Wigglesworthia glossinidia. The ancient coevolution of these species has led to the integration of Wigglesworthia metabolism into tsetse physiology and a subsequent reliance on nutrient exchange for maintaining the fitness of both partners. The establishment of this obligate mutualism has facilitated the emergence of feedback mechanisms that stabilize the symbiosis, such as that which involves the exchange of L-serine and B vitamins. The Gammaproteobacteria Wigglesworthia supplement B vitamins lacking …

Mimicking Biofilms: Photosynthetic Assessments Of C. Reinhardtii In 3 Physical Forms, John Michael Roesgen

Biology ETDs

Oxygenic photosynthesis supports the majority of life on Earth through the capture of energy from sunlight and the assimilation of CO₂ into basic building blocks of cells. Microalgae are fast growing and account for about half of global photosynthesis. In addition, they can be cultivated and their metabolism can be redirected to generate additional useful products ranging from biofuels to pharmaceuticals. However, the efficiency of metabolite production is severely impacted by the slow diffusion of CO₂ through water and the high energetic costs of harvesting microalgae from liquid cultures. Microalgae grow in open water, but they also form …

Short Chain Fatty Acid Combination Treatment Protects Against 6-Ohda And Wt Α-Synuclein Induced Decreases In Neurite Growth In In Vitro Models Of Parkinson’S Disease., Alex Morris

ORBioM (Open Research BioSciences Meeting)

Background

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by dopaminergic neuron degeneration. This degeneration is partly driven by over expression of α-synuclein (α-syn) and development of α-syn aggregates known as Lewy bodies throughout the substantia nigra. As well as motor dysfunction, PD presents with several chronic gastrointestinal comorbidities, which cause a decline of gut microbial diversity and microbially derived short chain fatty acids (SCFAs). Recent in vivo studies have shown SCFAs to be neuroprotective in various degenerative disease states, suggesting that SCFAs may protect against dopaminergic degeneration.

Methods

Human neuroblastoma SH-SY5Y cells were used as a model of human …

Bactericidal Effects Of Chlorine And Bacteriophages On Mycobacteria In Conventionally Treated Water., Max Kevane-Campbell

ORBioM (Open Research BioSciences Meeting)

Introduction

Mycobacteria are members of the order Actinomycetales and the only genus in the family Mycobacteriaceae. The distinguishing characteristics that are found in mycobacteria include acid-fastness and the presence of mycolic acids. Mycobacteria can be commonly classified as non-spore-forming, aerobic, slender rod-shaped, and are slow-growers. Natural reservoirs that mycobacteria can be found in are aquatic and terrestrial environments. Recent studies have shown that mycobacteria that can cause skin lesions, immune and/or pulmonary dysfunctions and chronic diseases, i.e., Mycobacterium avium subsp. Paratuberculosis, M. kansasii, and M. xenopi, can be isolated from common household tap water. Tap water can originate from …

Canine Testes Thin Sections Culture​, Nguyen Khoi Nguyen, Ramanpreet Singh

2023 Symposium

Canine testes thin section culture

Testes tissue culture systems would provide a tool to elucidate spermatogenesis mechanisms, with the aim of genetic preservation of mammals, especially endangered species. Our experiment aims to develop a culture system capable of producing viable mammalian sperm cells in vitro.

Dogs were chosen as the model organism because testes are readily available. Canine testes were obtained from a local veterinary clinic. Thin sections were generated using a commercial electric slicer. They then were cleaned using Dulbecco’s Phosphate-Buffered Saline (DPBS) supplemented with antibiotics then cultured in a modified Tissue Culture Medium 199 (TCM-199). Sections were …

Canine Testes Thin Sections Culture, Nguyen Khoi Nguyen, Ramanpreet Singh

2023 Symposium

Canine testes thin section culture

Testes tissue culture systems would provide a tool to elucidate spermatogenesis mechanisms, with the aim of genetic preservation of mammals, especially endangered species. Our experiment aims to develop a culture system capable of producing viable mammalian sperm cells in vitro.

Dogs were chosen as the model organism because testes are readily available. Canine testes were obtained from a local veterinary clinic. Thin sections were generated using a commercial electric slicer. They then were cleaned using Dulbecco’s Phosphate-Buffered Saline (DPBS) supplemented with antibiotics then cultured in a modified Tissue Culture Medium 199 (TCM-199). Sections were …

What Is Microbial Dormancy?, Mark D. Mcdonald, Carlos Owusu-Ansah, Jared B. Ellenbogen, Zachary D. Malone, Michael P. Ricketts, Steve E. Frolking, Jessica Gilman Ernakovich, Michael Ibba, Sarah C. Bagby, J. L. Weissman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Life can be stressful. One way to deal with stress is to simply wait it out. Microbes do this by entering a state of reduced activity and increased resistance commonly called ‘dormancy’. But what is dormancy? Different scientific disciplines emphasize distinct traits and phenotypic ranges in defining dormancy for their microbial species and system-specific questions of interest. Here, we propose a unified definition of microbial dormancy, using a broad framework to place earlier discipline-specific definitions in a new context. We then discuss how this new definition and framework may improve our ability to investigate dormancy using multi-omics tools. Finally, we …

Investigating Transcriptional Anomalies During Persistence In Chlamydia Trachomatis, Nathan D. Hatch

Theses & Dissertations

Chlamydia trachomatis (Ctr) is the leading cause of bacterial sexually transmitted infections. Ctr, a Gram-negative, obligate intracellular bacterium, develops within a membrane-bound vacuole termed an inclusion. This protective, nutrient rich, intracellular environment has allowed Ctr to undergo extensive reductive evolution – resulting in a streamlined genome of approximately 1 Mbp and the loss or fragmentation of several biosynthetic pathways, including the ability to synthesize tryptophan (Trp) de novo. During infection, the host immune system releases the cytokine IFNγ. Upon binding to a host cell, IFNγ stimulates the expression of indoleamine-2,3-dioxygenase, an enzyme capable of catabolizing cytosolic Trp, thereby starving …

The Stringent Response In Pseudomonas Aeruginosa Influences The Phenotypes Controlled By The Gac/Rsm System, Michael Shawn Hooker

Electronic Theses and Dissertations

Pseudomonas aeruginosa is a ubiquitous, opportunistic pathogen that causes acute and chronic infections. Infection is typically initiated via motile and virulent strains. After exposure to stressors, acute infections make both genotypic and phenotypic switches to a chronic, sessile strain. This is due to intricate regulatory networks directing gene expression in response to stressors. One network, GacA/GacS, has been established to control virulence factors. The stringent response of bacteria is mediated by alarmones produced primarily by RelA which responds to starvation.

To study the effect of the stringent response on the virulence switch. A series of experiments were run in both …

Rna Virus-Mediated Changes In Organismal Oxygen Consumption Rate In Young And Old Drosophila Melanogaster Males, Eli Hagedorn, Dean Bunnell, Beate Henschel, Daniel Smith Jr, Stephanie Dickinson, Andrew Brown, Maria De Luca, Ashley Turner, Stanislava Chtarbanova

Research, Publications & Creative Work

Aging is accompanied by increased susceptibility to infections including with viral pathogens resulting in higher morbidity and mortality among the elderly. Significant changes in host metabolism can take place following virus infection. Efficient immune responses are energetically costly, and viruses divert host molecular resources to promote their own replication. Virus-induced metabolic reprogramming could impact infection outcomes, however, how this is affected by aging and impacts organismal survival remains poorly understood. RNA virus infection of Drosophila melanogaster with Flock House virus (FHV) is an effective model to study antiviral responses with age, where older flies die faster than younger flies due …

Evaluation Of Some Toxic Trace Elements In Crocus Sativus L. And Soil Using Neutron Activation Analysis Technique, Ehsan Taghizadeh Tousi

The Philippine Agricultural Scientist

Neutron activation analysis was used in this research to measure the concentrations of aluminum (Al), bromine (Br), chlorine (Cl), mercury (Hg), arsenic (As), and thorium (Th) in soil and saffron plants as well as their contamination, enrichment, and translocation rates. The edible part of the saffron showed a higher Hg concentration than the WHO/FAO-permitted level in the urban area. The soil was not intoxicated and contaminated by Al, As, and Th except in the urban areas, which were slightly polluted by As. The calculated contamination degree and pollution load index indicated that the soil was almost uncontaminated. The enrichment factors …

Sex-Dependent Effects Of Induced Acute Inflammation On Glucose Homeostasis And Rna Editing Enzymes, Christian A. Rivas

Graduate Theses/Dissertations

The first line of defense against bodily insults, like pathogen invasion, is the innate immune system. Innate immunity sets in motion countless cascades that result in inflammation. Inflammation simultaneously affects multiple biological processes like metabolism and gene expression. Males and females react differently to inflammation. To understand both molecular and physiological sex differences in inflammation, we examined how inflammation affects gene expression and glucose metabolism. Adenosine deaminase acting on RNA (ADAR1) is upregulated by inflammation and catalyzes RNA editing, a process where nucleotides encoded by the genome are modified. ADAR1 also controls the innate immune reaction by decreasing activity of …

Editorial: New Frontiers In The Application Of Stable Isotopes To Ecological And Ecophysiological Research, Keith A. Hobson, John P. Whiteman, Seth D. Newsome

Biological Sciences Faculty Publications

No abstract provided.

The Role Of Dha In The Impact Of Trem2 On Microglia Activation And Alzheimer’S Disease, Michael A. Palmieri Iii

Seton Hall University Dissertations and Theses (ETDs)

Alzheimer’s disease (AD) is a neurological disease that is associated with microglia activation. An important receptor involved in microglia activation is Triggering receptor expressed on myeloid cells 2 (TREM2). Recent studies suggest that docosahexaenoic acid (DHA) could reduce the neuroinflammation that is associated with microglia activation. We hypothesized that when DHA concentration was increased, TREM2 expression would decrease, microglia activity would be inhibited, and a resulting decrease in neuroinflammation would be observed. We examined peer-reviewed journal articles from 2017-2022 that investigated the relationship between TREM2 activation and severity of AD symptoms, the protective properties of DHA against AD, and the …

Optimization Of Clostridium Septicum Antigen Production And Evaluation Of Vaccine Administration Parameters For A Candidate Bacterin-Toxoid To Prevent Dermatitis In Commercial Turkeys, Aaron Forga

Graduate Theses and Dissertations

The objective of this thesis was to optimize the hemolytic activity of two isolates of Clostridium septicum to evaluate if hemolytic titer of C. septicum antigen at time of formalin inactivation corresponded to increased serum antibody titer to the C. septicum alpha-toxin of turkeys immunized with an experimental formalin inactivated bacterin-toxoid vaccine. Chapter 1 provides a brief overview of the thesis. Chapter 2 consists of a literature review focused on clostridial dermatitis, specifically C. septicum-associated dermatitis (cellulitis) that affects commercial turkeys. Chapter 3 outlines our attempts to optimize an experimental autogenous bacterin-toxoid vaccine as a potential strategy to mitigate clostridial …

Mutation Of Aspergillus Sp. Using Ultraviolet Light And Nitrous Acid For Amylase Production From Banana Peels, Cyprian Erumiseli Oshoma, Johnson Oche Akor, Beckley Ikhajiagbe, Marcel James Ikenebomeh

Makara Journal of Science

Strain improvement through mutagenesis is important in the commercial development of microbial fermentation. This study aimed to produce amylase from banana (Musa sapientum) peels by using mutant Aspergillus sp. strains obtained via ultraviolet (UV) radiation and nitrous acid-based mutagenesis. Results revealed that banana peels pretreated with 0.8 N HCl had a biomass yield of 3.02 g/L and amylase activity of 2.81 U/L. Of the UV mutants, strain AUV1 had the highest biomass and amylase activity of 4.50 ± 0.21 g/L and 3.46 ± 0.14 U/L, respectively. Subsequently, HNO₂ mutants showed that strain ANA6 had 30.64% and …

Identification And Characterization Of Genetic Elements That Regulate A C-Di-Gmp Mediated Multicellular Trait In Pseudomonas Fluorescens, Collin Kessler

Electronic Theses and Dissertations

Microbial communities contain densely packed cells where competition for space and resources are fierce. These communities are generally referred to as biofilms and provide advantages to individual cells against immunological and antimicrobial intervention, dehydration, and predation. High intracellular pools of cyclic diguanylate monophosphate (c-di-GMP) cause cells to aggregate during biofilm formation through the production of diverse extracellular polymers. Genes that encode c-di-GMP catalytic enzymes are commonly mutated during chronic infections where opportunists display enhanced resistance to phagocytosis and antibiotics. Our lab uses an emergent multicellular trait in the model organism Pseudomonas fluorescens Pf0-1 to study the emergence of c-di-GMP mutations …