Life Sciences Commons^™

Quantifying Species Traits Related To Oviposition Behavior And Offspring Survival In Two Important Disease Vectors, Donald A. Yee, William C. Glasgow, Nnaemeka F. Ezeakacha

Faculty Publications

Animals with complex life cycles have traits related to oviposition and juvenile survival that can respond to environmental factors in similar or dissimilar ways. We examined the preference-performance hypothesis (PPH), which states that females lacking parental care select juvenile habitats that maximize fitness, for two ubiquitous mosquito species, Aedes albopictus and Culex quinquefasciatus. Specifically, we examined if environmental factors known to affect larval abundance patterns in the field played a role in the PPH for these species. We first identified important environmental factors from a field survey that predicted larvae across different spatial scales. We then performed two experiments, …

Tick-Borne Pathogens Shape The Native Microbiome Within Tick Vectors, Abdulsalam Adegoke, Deepak Kumar, Cailyn Bobo, Muhammad Imran Rashid, Aneela Zameer Durrani, Muhammad Sohail Sajid, Shahid Karim

Faculty Publications

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Ticks are blood-feeding arthropods and transmit a variety of medically important viral, bacterial, protozoan pathogens to animals and humans. Ticks also harbor a diverse community of microbes linked to their biological processes, such as hematophagy, and hence affect vector competence. The interactions between bacterial and/or protozoan pathogens and the tick microbiome is a black-box, and therefore we tested the hypothesis that the presence of a protozoan or bacterial pathogen will alter the microbial composition within a tick. Hence, this study was designed to define the microbial composition of two tick species, …

Draft Genome Sequences Of Six Strains Isolated From The Rhizosphere Of Wheat Grown In Cadmium-Contaminated Soil, Vira Hovorukha, Ankita Bhattacharyya, Olga Iungin, Hanna Tashyreva, Victoria Romanovska, Olesia Havyrliuk, Olena Bielikova, Claire Blackwell, Brian Burks, Cara Cothern, Jakia Elliott, Jonathan Hoover, Alexis Jones, Christian Leise, Linda Lowmiller, Ahmed Mohamed, Tiffany Mullen, Ethan Nettleton, Karshanda Polk, Benny Tran, Teresa Tran, Manuel Vega, Landon Ware, Emily Welch, Leandra Williams, Madison Woodward, Kaylin Young, Olga Mavrodi, Oleksandr Tashyrev, Dmitri Mavrodi

Faculty Publications

This study presents high-quality draft genome assemblies of six bacterial strains isolated from the roots of wheat grown in soil contaminated with cadmium. The results of this study will help to elucidate at the molecular level how heavy metals affect interactions between beneficial rhizobacteria and crop plants.

Exploiting Somatic Pirnas In Bemisia Tabaci Enables Novel Gene Silencing Through Rna Feeding, Mosharrof Mondal, Judith K. Brown, Alex Flynt

Faculty Publications

© This article is available under a Creative Commons License (Attribution 4.0 International, as described at https://creativecommons.org/licenses/by/4.0/). RNAi promises to reshape pest control by being nontoxic, biodegradable, and species specific. However, due to the plastic nature of RNAi, there is a significant variability in responses. In this study, we investigate small RNA pathways and processing of ingested RNAi trigger molecules in a hemipteran plant pest, the whitefly Bemisia tabaci. Unlike Drosophila, where the paradigm for insect RNAi technology was established, whitefly has abundant somatic piwi-associated RNAs (piRNAs). Long regarded as germline restricted, piRNAs are common in the …

The "Challenge" Of Depletion: Why The Oyster Fishery Is Not Self-Regulating, Eric N. Powell, John M. Klinck, Leanne M. Poussard

Faculty Publications

© 2020 National Shellfisheries Association. All rights reserved. The possibility that the economics of the oyster fishery impose a self-limitation on overharvesting has been proffered on occasion. The inefficiency of harvesting by the fishery has been evaluated and estimates of the exploitation rate permissible under conditions of maximum sustainable yield have been obtained in previous studies. The question becomes to what extent does the inefficiency of harvest interact with the economics of the fishery to compromise ready detection of overfishing? This study explores the possibility that the constraint of economics on the fishery occurs at oyster exploitation rates that are …

Interrelationships Among Monorchiid Trematodes With Special Emphasis On Some Northwestern Atlantic Genera, Apryle Panyi

Master's Theses

The Monorchiidae Odhner, 1911 is a cosmopolitan family of flukes (Trematoda: Digenea) comprising species that parasitize the digestive tract of estuarine and marine fishes as adults. Compared with other oceans, recent morphological or molecular taxonomic work conducted on monorchiid species from the northwestern Atlantic Ocean has been sparse (Manter, 1931; Overstreet, 1969; Andres et al., 2018; Wee et al., 2018, 2019, 2020). Therefore, the present work investigated the interrelationships of some monorchiids from the northwestern Atlantic Ocean with emphasis on several genera and investigated if Lasiotocus minutus (Manter, 1931) Thomas, 1959 constitutes a complex of cryptic species. New morphological and …

Comparison Of Retention Rates Between Traditional On-Ground And Online Biology Laboratory Courses In The Community College Setting, Megan Davis Winborne

Dissertations

Community colleges provide vital educational resources to students across the nation. Online learning has become an integral part of the course offerings for community colleges. With regards to online learning, there is a lack of empirical evidence and research focused on community college offered biology laboratories, particularly concerning retention rates of these students. Means, Toyama, Murphy, and Bakia. (2013) found that even though there are copious amounts of studies dedicated to evaluation of evidence-based practices in online learning formats, many of them neglected to review retention rates associated with online educational courses.

The purpose of this study was to determine …

The Effect Of Constant Relative Growth Rate Versus Constant Specific Growth Rate On Oocystis Sp, Rachel Kriner

Master's Theses

In this study, a strain of Oocystis sp. (S002) was grown using two different growth strategies at three different temperatures (15°C, 20°C, 25°C). One strategy (GS1) kept a constant specific growth rate (µ) and the other (GS2) kept a constant relative growth rate (µ/µ_max). In both strategies, the cultures were grown following the protocols of a hybrid growth system. The Dilution Phase is an initial semi-continuous growth phase that involves daily dilutions until set growth criteria are met. Followed by a batch culture growth protocol where the cultures were diluted at the onset of the first day and …

Do Mosquito Pesticides Harm Their Natural Enemies? Ecological Impacts And Non-Target Effects Of Larvicides On Mosquito Predators, Joseph Nelsen

Master's Theses

Larvicides are chemicals used to kill juvenile mosquitoes. When applied to an area, other aquatic organisms are exposed to these chemicals. The removal or impairment of top insect predators could be beneficial to mosquito populations once harmful pesticide levels dissipate. Two common larvicides were examined: growth regulators (IGRs) and surface films (SFs). The goal of this project was to determine if larvicides harm mosquito predators common to southern Mississippi. I surveyed aquatic sites before and after IGR and SF treatments, and then compared changes in insect community structure. Community evenness was lower in SF treated habitats. When analyzing prey taxa …

Discovery Of Exosomes From Tick Saliva And Salivary Glands Reveals Therapeutic Roles For Cxcl12 And Il-8 In Wound Healing At The Tick–Human Skin Interface, Wenshuo Zhou, Faizan Tahir, Joseph Che Yen Wang, Michael Woodson, Michael B. Sherman, Shahid Karim, Girish Neelakanta, Hameeda Sultana

Faculty Publications

© Copyright © 2020 Zhou, Tahir, Wang, Woodson, Sherman, Karim, Neelakanta and Sultana.Ticks secrete various anti-coagulatory, anti-vasoconstrictory, anti-inflammatory, and anti-platelet aggregation factors in their saliva at the bite site during feeding to evade host immunological surveillance and responses. For the first time, we report successful isolation of exosomes (small membrane-bound extracellular signaling vesicles) from saliva and salivary glands of partially fed or unfed ixodid ticks. Our data showed a novel role of these in vivo exosomes in the inhibition of wound healing via downregulation of C-X-C motif chemokine ligand 12 (CXCL12) and upregulation of interleukin-8 (IL-8). Cryo-electron microscopy (cryo-EM) analysis …

Laboratory Colonization By Dirofilaria Immitis Alters The Microbiome Of Female Aedes Aegypti Mosquitoes, Abdulsalam Adegoke, Erik Neff, Amie Geary, Montana Ciara Husser, Kevin Wilson, Shawn Michael Norris, Guha Dharmarajan, Shahid Karim

Faculty Publications

Background

The ability of blood-feeding arthropods to successfully acquire and transmit pathogens of medical and veterinary importance has been shown to be interfered with, or enhanced by, the arthropod’s native microbiome. Mosquitoes transmit viruses, protozoan and filarial nematodes, the majority of which contribute to the 17% of infectious disease cases worldwide. Dirofilaria immitis, a mosquito-transmitted filarial nematodes of dogs and cats, is vectored by several mosquito species including Aedes aegypti.

Methods

In this study, we investigated the impact of D. immitis colonization on the microbiome of laboratory reared female Ae. aegypti. Metagenomic analysis of the V3–V4 variable …

Quantifying Spatiotemporal Variability In Zooplankton Dynamics In The Gulf Of Mexico With A Physical-Biogeochemical Model, Taylor A. Shropshire, Steven L. Morey, Eric P. Chassignet, Alexandra Bozec, Victoria J. Coles, Michael R. Landry, Rasmus Swalethorp, Glenn Zapfe, Michael R. Stukel

Faculty Publications

© 2020. This work is distributed under the Creative Commons Attribution 4.0 License. Zooplankton play an important role in global biogeochemistry, and their secondary production supports valuable fisheries of the world's oceans. Currently, zooplankton standing stocks cannot be estimated using remote sensing techniques. Hence, coupled physical–biogeochemical models (PBMs) provide an important tool for studying zooplankton on regional and global scales. However, evaluating the accuracy of zooplankton biomass estimates from PBMs has been a major challenge due to sparse observations. In this study, we configure a PBM for the Gulf of Mexico (GoM) from 1993 to 2012 and validate the model …

Light And Temperature Mediate Algal Simulation Of Heterotrophic Activity On Decomposing Leaf Litter, Cody A. Pope, Halvor M. Halvorson, Robert H. Findlay, Steven N. Francoeur, Kevin A. Kuehn

Faculty Publications

1. Recent evidence suggests that periphytic algae stimulate plant litter heterotrophs (fungi and bacteria) in the presence of light, but few studies have tested whether this stimulation varies across gradients of light, which may covary with temperature.
2. We exposed field‐conditioned Typha domingensis litter to fully‐crossed, short‐term gradients of temperature (15, 20, 25, and 30°C) and light (0, 25, 53, 123, and 388 µmol quanta m⁻² s⁻¹) and measured responses of litter‐associated algal, fungal, and bacterial production rates and β‐glucosidase, β‐xylosidase, and phenol oxidase enzyme activities in the laboratory.
3. Increased light stimulated algal production rates, from immeasurable production under …

Temporal And Stoichiometric Patterns Of Algal Stimulation Of Litter-Associated Heterotrophic Microbial Activity, Steven N. Francoeur, Robert K. Neely, Savannah Underwood, Kevin A. Kuehn

Faculty Publications

1. Periphyton communities associated with submerged plant detritus contain interacting autotrophic and heterotrophic microbes, and are sites of extracellular enzymatic activity. The strength and nature of these interactions might be expected to change over time as microbial communities develop on plant litter. Microbial interactions and enzymatic activity can be altered by nutrient availability, suggesting that litter stoichiometry could also affect these phenomena.
2. We grew wetland plants under ambient and nutrient‐enriched conditions to generate plant litter of differing nutrient content. In two experiments, we investigated: (1) the influence of algal photosynthesis on fungal and bacterial production and the activities of four extracellular …

Combined And Independent Effects On Hypoxia And Tributylin On Mrna Expression And Physiology Of The Eastern Oyster (Crassostrea Virginica), Ann Fairly Barnett, James H. Gledhill, Robert J. Griffitt, Marc Slattery, Deborah J. Gochfeld, Kristine L. Willett

Faculty Publications

Oyster reefs are vital to estuarine health, but they experience multiple stressors and globally declining populations. This study examined effects of hypoxia and tributyltin (TBT) on adult Eastern oysters (Crassostrea virginica) exposed either in the laboratory or the field following a natural hypoxic event. In the laboratory, oysters were exposed to either hypoxia followed by a recovery period, or to hypoxia combined with TBT. mRNA expression of HIF1-α and Tβ-4 along with hemocyte counts, biomarkers of hypoxic stress and immune health, respectively, were measured. In field-deployed oysters, HIF1-α and Tβ-4 expression increased, while no effect on hemocytes was …

Impact Of A Preschool Obesity Program (I-Pop) Program On Nutrition Knowledge Scores Of Head Start Parents And Teachers, Holly Huye, Carol Connell, Caroline Newkirk

Faculty Publications

Objectives: To determine the effectiveness of an evidence-based preschool obesity prevention intervention on rural, low-income parents’ and Head Start teachers’ nutrition knowledge relative to advice from experts, nutrient content of foods, and health benefits of foods.

Methods: Parent-child dyads were recruited from 9 randomized Head Start centers with 5 centers in the experimental group and 4 centers in the control. The intervention consisted of 8 weekly evidence-based nutrition education sessions for children delivered by the Head Start teachers; a teacher workshop on the use of Positive Behavior Interventions and Supports (PBIS) in the classroom; and 8 parent workshops …

Chemoenzymatic Study Of Coa-Linked Rna In Bacteria, Krishna Sapkota

Dissertations

The ability of RNA to store genetic information and to catalyze biochemical transformations led to the speculation of the existence of RNA world before the evolution of contemporary ribonucleoprotein (RNP) world. Recent discovery of RNA molecules containing metabolic cofactors including coenzyme A and its various thioesters at their 5’ end further supported the RNA world hypothesis as these CoA-linked RNA molecules could be the molecular fossils with very ancient origin. As both RNA and Coenzyme A are believed to have co-existed since last universal common ancestor (LUCA) or even before, the CoA-RNA conjugates in current biology may reveal fundamental molecular …

The Ecology And Evolutionary History Of Two Musk Turtles In The Southeastern United States, Grover Brown

Dissertations

Turtles are among one of the most imperiled vertebrate groups on the planet with more than half of all species worldwide listed as threatened, endangered or extinct by the International Union of the Conservation of Nature. The Southeastern United States is a global biodiversity hotspot for turtles, and it likely represents the last area on the planet of both high diversity and high abundance of turtle species. In the past century, there has been an exponential increase in the number of publications on turtles in the United States and Canada, however a recent review of the literature suggests that this …

Antibiotic Resistant Bacteria, Antibiotic Resistance Genes And Potential Drivers In The Aquatic Environments, Shuo Shen

Dissertations

As antibiotic resistance genes in aquatic environment have been increasing across the world, affecting water quality and public health, many studies documented concentrations of antibiotic resistance genes and some studies discussed their potential drivers. However, systematic and quantitative reviews that link antibiotic resistance genes (ARGs) to anthropogenic and environmental factors are limited. Nevertheless, this information will be important for developing regulation policy on controlling antibiotic use and therefore reducing potential risks to antibiotic resistance. I conducted meta-analysis of ARGs concentration at a global scale using Bayesian inference to explore climatic and socio-economic factors as drivers. I found local-scale climatic variables …

Vegetative Community And Health Assessment Of A Constructed Juncus-Dominated Salt Marsh In The Northern Gulf Of Mexico, Nickolas R. Murphy

Master's Theses

Deer Island is a coastal habitat which provides a buffer from storm and flood damage as well as shore-line stabilization to the mainland of Biloxi, Mississippi. A third of the land has been lost since 1850, largely driven by tropical storm and hurricane impacts as well as sea level rise. The United States Army Corps of Engineers and Mississippi Department of Marine Resources have targeted the shores of the island as sites for restoration using beneficial use dredged material, and two sites of differing age have since been planted with Spartina alterniflora, Juncus roemerianus, Uniola paniculata, S. patens, and Panicum …

An Analysis Of Dredge Efficiency For Surfclam And Ocean Quahog Commercial Dredges, Leanne Poussard

Master's Theses

Between 1997 and 2011, The National Marine Fisheries Service conducted 50 depletion experiments to estimate survey gear efficiency and stock density for Atlantic surfclam (Spisula solidissima) and ocean quahog (Arctica islandica) populations using commercial hydraulic dredges. The Patch Model was formulated to estimate gear efficiency and organism density from the data. The range of efficiencies estimated is substantial, leading to uncertainty in the application of these estimates in stock assessment. Analysis of depletion experiment simulations showed that uncertainty in the estimates of gear efficiency from depletion experiments was reduced by higher numbers of dredge tows per experiment, more tow overlap …

Development Of An Attenuated Zika Virus By Editing The 5’ Untranslated Region, E. Ashley Thompson

Master's Theses

Zika Virus (ZIKV) is a mosquito-transmitted flavivirus that usually causes no symptoms to mild febrile in humans, and it has been regarded as an insignificant pathogen to public health. However, recent outbreaks of ZIKV infection have revealed that ZIKV can cause severe neurological effects in adults, such as Guillain-Barre Syndrome (GBS), and in infants whose mothers acquired the virus during pregnancy, causing Congenital Zika Syndrome (CZS). Currently, no approved vaccine is available and there is a critical need to develop an effective and safe vaccine. While most vaccine developmental strategies target the viral prM-E protein of ZIKV, we aimed to …

Amplification And Potential Transformation Of Human Syntaxin-17 Into Model E. Coli, Taylor H. Gore

Honors Theses

Membrane fusion is key to organism homeostasis and occurs when a transport vesicle fuses with a target compartment, merging the two membranes into one while releasing the contents of the transport vesicle into the target compartment. This process is controlled by SNARE proteins. Syntaxin-17 protein plays a crucial role in the fusion of the autophagosome membrane with the lysosome membrane, allowing for degradation of misfolded intracellular components and pathogens. Intriguingly, Syntaxin 17 has been identified as a target of herpesvirus tegument proteins, although the pathological significance of the Syntaxin 17 and tegument protein interaction is unclear. As a first step …

Regulation Of Weak Acid-Dependent Cell Death By The Msaabcr Operon During Biofilm Formation Of Staphylococcus Aureus, Sarah-Elizabeth M. Polley

Honors Theses

Staphylococcus aureus is a dangerous human pathogen and a leading cause of both nosocomial and community-associated infections. Infection by S. aureus is a growing health concern due to the emergence of antibiotic resistance and the capability to form robust biofilms. Major constituents of the biofilm extracellular matrix are demonstrated to be released via controlled autolysis of a subpopulation of the biofilm. As indicated in past studies, the programmed cell death (PCD) of S. aureus grown in a biofilm microenvironment is potentiated by the buildup of acetate, a byproduct of glucose metabolism, which causes cytoplasmic acidification. Furthermore, it has been shown …

Regional Differences In Wild North American River Otter (Lontra Canadensis) Behavior And Communication, Sarah Walkley

Dissertations

This study focuses on the vocalization repertoires of wild North American river otters (Lontra canadensis) in New York and California. Although they are the same species, these two established populations of river otters are separated by a significant distance and are distinct from one another. River otters are semi-aquatic social predators that can be found throughout North America. This is the first study to examine the vocalizations of wild river otters, and results are compared across field sites in the different regions. River otter vocalizations and behaviors in New York were recorded using Bushnell Aggressor trail cameras that …

Assessing The Effect Of Bile And Oxygen Availability On The Redox Status Of Listeria Monocytogenes Strain F2365, Sukriti Bhattarai

Honors Theses

Although bile is a bactericidal agent able to disrupt membrane structure and cellular homeostasis, including the induction of oxidative stress, Listeria can tolerate bile and also utilize it as a signal to enhance infection and virulence. Preliminary findings showed that under anaerobic conditions, exposure to bile significantly lowered the amount of oxidative damage present in bile-resistant strain F2365 cells. Similarly, Listeria further elicits an adaptive immune response, wherein pre-exposure of the bacterium to stress during food processing or in the host prior to entry into the intestine increases bile tolerance. Based on these previous studies, we hypothesized that bile induces …

Alpha-Gal Syndrome: Molecular Characterization Of Amblyomma Americanum Α-D-Galactosidase In Α-Gal Metabolism And Onset Of Red Meat Allergy, Ahmed A. Mohamed

Honors Theses

Tick-borne red meat allergy is an IgE-mediated delayed hypersensitivity reaction, increasingly widespread in tick endemic areas in the United States of America, and worldwide. Bites from the lone-star tick (Amblyomma americanum) are believed to be involved as the source of the sensitization of humans to the oligosaccharide galactose-⍺-1,3-galactose (α-gal), which is found in most mammal-derived food products, including gelatin, broths, and red meat. The purpose of this study is to functionally characterize the lone-star tick α-D-galactosidase (AGS) enzyme and assess its role in α-gal metabolism. This enzyme cleaves terminal α-galactose moieties from glycoproteins and glycolipids. Hence, I hypothesized …

Determining The Association Between Religious Participation And Spirituality And Diet And Physical Activity Behaviors In African Americans Of Mississippi, Nidhi Shrestha

Honors Theses

According to CDC, African Americans experience higher rates of chronic diseases when compared to other ethnic groups. Focusing on religiosity and spirituality may benefit the health status of this minority group where advanced healthcare facilities are not easily assessable. The purpose of this research is to 1. Examine demographic factors related to religiosity/spirituality factors among a sample of African American Mississippians; and 2. Determine the correlation between their religiosity, spirituality, and health behaviors. The study uses the data collected by the Mississippi INBRE Telenutrition Center at The University of Southern Mississippi (USM). Participants for this study were recruited from May …

Cloning And Expression Of Human Synaptosome Associated Protein 29 In E. Coli, Logan M. Ryals

Honors Theses

Acting as the chief mediators of vesicular fusion, soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) play a role in many intracellular trafficking events by moving opposing membranes into close proximity. One such event takes place in the process of autophagy. A key SNARE involved in autophagy is Synaptosome Associated Protein 29 (SNAP-29), which acts on the autophagosome membrane to promote autophagosome and lysosome fusion. Kaposi’s Sarcoma Herpesvirus (KSHV) proteins ORF33 and ORF38 were demonstrated to interact with SNAP-29. The exact mechanism of this interaction is yet to be elucidated but it is hypothesized that these interactions allow KSHV to modulate …

Investigating Roles For Rna Turnover Processes In Cell Signaling Through Drosophila Melanogaster Genetic Mosaics, Sudiksha Rathan Kumar

Honors Theses

The process of cell signaling is vital in organisms for proper development as it determines the fate and function of cells. This process is highly regulated by myriad interactions between signaling pathway components and gene expression mechanisms. RNA turnover is a type of RNA processing that degrades RNA. It plays an essential role in homeostasis and environmental changes; however, its influence on signaling pathways is currently unknown. In the present study, the effect of RNA turnover processes on cell signaling was analyzed using the genetic mosaics in Drosophila melanogaster. Fly mosaics were created by breeding RNAi lines targeting cellular …