Life Sciences Commons^™

The Potential For Dickeya Dianthicola To Be Vectored By Two Common Insect Pests Of Potatoes, Jonas K. Insinga

Electronic Theses and Dissertations

Dickeya dianthicola (Samson) causing blackleg and soft rot was first detected in potatoes grown in Maine in 2014. Previous work has suggested that insects, particularly aphids, may be able to vector bacteria in this genus between plants, but no conclusive work has been done to confirm this theory. In order to determine whether insect-mediated transmission is likely to occur in potato fields, two model potato pests common in Maine were used: the Colorado potato beetle (Leptinotarsa decimlineata Say) and the green peach aphids (Myzus persicae Sulzer). Olfactometry and recruitment experiments evaluated if either insect discriminates between infected and …

Genetic Relationships Using Mitochondrial Versus Nuclear Markers: Is The Catfish Rag1 Gene Suitable For Species Differentiation In The Family Pangasiidae?, Huong Thanh Hoang

Graduate Theses and Dissertations

The Mekong River located in Southeast Asia is a global “hotspot” for aquatic biodiversity. It includes an extensive variety of fish species second only to the Amazon River in South America. Recent studies have revealed the impacts of anthropogenic and climate factors on this river system. Such impacts can result in the formation of barriers, which divide a species population and impede gene flow between separated sub-populations. Barriers influence evolutionary trajectories resulting in the generation of geographic variants or subspecies from an ancestral population. Catfish (Teleostei: Siluriformes) are a key species of the Mekong River ecosystem and are an essential …

The Role Of Membrane Domains In Protein And Lipid Sorting During Endocytic Traffic, Blanca B. Diaz-Rohrer

Dissertations & Theses (Open Access)

The lipid and protein composition of the plasma membrane (PM) must be tightly controlled to maintain cellular functionality, despite constant, rapid endocytosis. Because de novo synthesis of proteins and lipids is energetically costly, the cell depends on active recycling to return endocytosed membrane components back to the PM. For most proteins, the mechanisms and pathways of their PM retention remain unknown. The work presented here shows that association with ordered membrane microdomains is fully sufficient for PM recycling and that abrogation of raft partitioning leads to their degradation in lysosomes. These findings support a model wherein ordered membrane domains mediate …

The Impact Of Anthropogenic Noise On Fish Behavior, Communication, And Development, Julie Butler

LSU Doctoral Dissertations

Noise pollution is pervasive to nearly all aquatic and terrestrial ecosystems and was labeled a pollutant of global concern by the World Health Organization in 2011. In the past few decades, underwater ambient noise levels have risen almost 30 dB SPL re: 1 µPa in the frequency range that most fish produce and detect acoustic stimuli due to rises in shipping, oil exploration, and pile driving. Changes to the natural soundscape can impact almost all aspects of an animal’s life. My dissertation research takes an integrative, whole-animal approach to examining how increased background noise impacts fish behavior, physiology, development, and …

Effects Of Intertidal Position On Metabolism And Behavior In The Acorn Barnacle, Balanus Glandula, Kali Horn

Master's Theses

The intertidal zone is characterized by persistent, tidally-driven fluctuations in both abiotic (e.g., temperature, [O₂], salinity) and biotic (e.g., food availability, predation) conditions, which makes this a very physiologically challenging habitat for resident organisms. The magnitude and degree of variability of these environmental stressors differs between intertidal zones, with the most extreme physiological stress often being experienced by organisms in the high intertidal. Given that many of the fluctuating conditions in this environment are primary drivers of metabolic rate (e.g., temperature, [O₂], food availability), we hypothesized that sessile conspecifics residing in different tidal zones would exhibit …

Systematics Of Carex Section Laxiflorae (Cyperaceae), Jenna Dorey

Dissertations, Theses, and Capstone Projects

Carex, with more than 2100 species, is the most species-rich genus of flowering plants in temperate regions of the world. Members of the family Cyperaceae are colloquially known as sedges, and members of the genus Carex are called “true sedges.” Carex occur on every continent except for Antarctica, they thrive in a panoply of habitats, and are ecologically important as a forage source for wildlife, carbon sequestration, prevention of soil erosion, and providing habitat for fresh water invertebrates. Despite their importance many sedges are still poorly known, such as the woodland sedges in Carex section Laxiflorae, which is …

Differential Vulnerability To Window Collision Mortality Among Migratory Songbird Species, Olivia M. Colling

Electronic Thesis and Dissertation Repository

Millions of birds die annually in North America by colliding with windows. I investigated differential vulnerability to window collision among migratory songbird species using long-term citizen science datasets from two bird banding stations and the fatal light awareness program. I used negative binomial regressions to model species-specific catch ratios, a mixed-effects negative binomial regression to model trophic guild-specific catch ratios and mixed-effects logistic regressions to model the odds of catching different age classes. Species-specific vulnerability varied significantly. Blue-headed Vireos, Yellow-rumped Warblers and Ruby-crowned Kinglets were least vulnerable, while Ovenbirds, Common Yellowthroats, Fox Sparrows and Bay-breasted Warblers were most vulnerable. Foraging …

Methodological Advances For Understanding Social Connectivity And Environmental Implications In Multi-Use Landscapes, Matthew Clark

Boise State University Theses and Dissertations

Integrated social-ecological systems research is challenging; complicated feedback and interactions across scales in multi-use landscapes are difficult to decouple. Novel methods and innovative data sources are needed to advance social-ecological systems research. In this thesis, we use network science as a means of explicitly assessing feedback between social and ecological systems, and internet search data to better predict visitation in protected areas. This thesis seeks to provide empirical examples of emerging social-ecological systems science methods as a precedent for resource managers on-the-ground, as well as extending the line of scientific inquiry on the subject

In the first chapter of this …

Does Thermotolerance In Daphnia Depend On The Mitochondrial Function?, Rajib Hasan

Electronic Theses and Dissertations

Thermotolerance limit in aquatic organism is set by the ability to sustain aerobic scope to sudden temperature shifts. This study tested the genetic and plastic differences in thermotolerance of Daphnia that can be explained by the differences in the ability to retain mitochondrial integrity at high temperatures. Five genotypes with different biogeographic origins were acclimated to 18^ᵒC and 25^ᵒC. We developed a rhodamine 123 in-vivo assay to measure mitochondrial membrane potential and observed higher fluorescent in heat damaged tissues as the disruption of the mitochondrial membrane potential. Significant effects on temperature tolerance were observed with CCCP …

Obscurin Mediates Ankyrin Complex Formation In The Heart, Janani Subramaniam

Dissertations & Theses (Open Access)

Distinctly organized domains of receptors, ion channels, transporters, signaling molecules, cell adhesion molecules, and contractile proteins are crucial to cardiac function. Interactions between adaptor proteins such as ankyrins and cytoskeletal proteins such as obscurin play a pivotal role in organizing these functional domains in cardiomyocytes. Therefore, dysfunction of both ankyrin as well as obscurin lead to a host of cardiovascular diseases such as arrhythmias and cardiomyopathies. Alternative splicing of ankyrin yields numerous isoforms that interact with obscurin at various sub-cellular domains. And while some of these obscurin-ankyrin complexes have been studied, many others have not been characterized. Further, previous studies …

Analyzing Physiological Stress Response Using Dermal Swabs In Plethodon Montanus, John Tester

Undergraduate Honors Theses

Upon exposure to environmental stressors, amphibians such as Plethodon montanus will release corticosterone (CORT) thus causing a behavioral and physiological response to cope with the stress. Currently, there are several invasive ways of collecting CORT in salamanders. However, these techniques typically require euthanasia of the organism. We hypothesized that exposure of P. montanus to stressful handling conditions will result in elevations of CORT that can be detected through dermal swabbing. To test this, two experiments were conducted which involved swabbing the dorsal side of the trunk before and immediately after exposing P. montanus to two different environmental stressors. The first …

The Functional Conservation Of Frazzled In Insects, Benjamin Wadsworth

Graduate Theses and Dissertations

Axons in the developing embryo receive and react to signals that direct their growth to reach target tissues at specified locations. The signal pathways that direct midline crossing of axons during embryonic development have been comprehensively examined in the past years using the Drosophila ventral nerve cord or the spinal cord as a model system. A number of these signaling mechanisms are conserved, however disparities have been found between species in general strategy or the molecular signals controlling the response of axons to guidance cues.

The Netrin-Frazzled pathway has been shown to aid in midline crossing of axons in the …

Ecology Of Upland Snake Communities In Managed Montane Longleaf Pine Habitats Of Georgia, Miranda Gulsby

Master of Science in Integrative Biology Theses

Longleaf pine ecosystem decline in the Southeast United States has led to intensive land management implementation with the goal to benefit both the ecosystem and at-risk species. Addressing at-risk snake populations in these longleaf pine ecosystems, for instance, requires understanding both community and species level ecology of snakes in these managed forests. Data for snakes in the montane (mountain) longleaf pine habitats remains unclear since management practice implementation. Currently, intensive restoration of montane longleaf pine habitats is taking place within two Wildlife Management Areas (WMA) in the Raccoon Creek Watershed of Northwest Georgia, Sheffield and Paulding Forest. These areas differ …

Assessment Of Culverts And Bridges As Roosting Habitat For Perimyotis Subflavus (Tri-Colored Bat) And Disease Transmission Corridors For Pseudogymnoascus Destructans, Kelly Lutsch

Master of Science in Integrative Biology Theses

Pseudogymnoascus destructans is an emerging fungal pathogen causing precipitous declines in North American bats due to the development of white-nose syndrome. Since 2006, 34 U.S. states and 7 Canadian provinces have confirmed the presence of P. destructans. Due to the rapid spread of P. destructans across the eastern United States, habitat characterization and disease monitoring has become vital to conserving remnant populations. Bats have been observed in multiple states using non-traditional habitat, such as interstate culverts, for roosting. To investigate their use of anthropogenic structures in coastal Georgia, an area where P. destructans has yet-to-be detected, comprehensive bridge and …

Using Instream Stationary Antennas To Monitor The Movements Of Warm Water Fishes In A Reach Of Stream Bisected By A Culvert, William Commins

Master of Science in Integrative Biology Theses

In this study I investigated the differences in the non-migratory movement patterns of six fish species in a 280m reach of stream bisected by a culvert (impeded), and a 300m reach of stream with no movement barriers (unimpeded). This study took place between July 1, 2018 and November 14, 2018 in Raccoon Creek, Paulding County, Georgia. I used 12mm passive integrated transponder tags and four instream stationary antennas to monitor the movements 429 fishes. The antennas redetected 262 of the 429 individuals (61.1%), and 48% of fishes were redetected more than 10 times. The proportion of tagged individuals detected by …

Unraveling The Neurogenin/Ngn-1 Gene Regulatory Network Of C. Elegans Using Classical Genetics And Comparative Transcriptomics, Elyse Christensen

Master of Science in Integrative Biology Theses

Proper nervous system development is required for an organism’s survival and function. Defects in neurogenesis have been linked to neurodevelopmental disorders such as schizophrenia and autism spectrum disorders. Understanding the gene regulatory networks that orchestrate neural development, specifically cascades of proneural transcription factors, can better elucidate which genes are most essential in governing early neurogenesis. Neurogenins are a family of such factors that are both sufficient and necessary for the development of neural sub-types in mice, primarily through the regulation of other factors, particularly NeuroD. The objective of this study was to evaluate previously established regulatory targets of neurogenin(ngn-1 …

Neural Development To Neurodegeneration Through The Mind Of A Worm, Miranda Arnold

Master of Science in Integrative Biology Theses

Defects in the nervous system can impact the normal function of an organism. By examining mutations during neuronal development, we can better understand the significance of specific pathways. The EphR/ephrin pathway is crucial for axonal guidance during development. The simple organism, C. elegans, allow us to study the impact of EphR/ephrin genes on neuronal morphology, synapse connections, and basic behavior. In specific EphR/ephrin mutants, we see change in morphology and loss of synapses in a thermosensory and also a chemosensory circuit. These mutations can also lead to defects in food searching behaviors. These observations lead us to conclude that …

Molecular Detection Of Pathogenic Leptospira Throughout The Caribbean, Zamara R. Garcia Truitt

Biology Theses

Leptospirosis is a common widespread zoonotic disease found throughout the Caribbean. The infection is produced by a pathogenic Leptospira species found in tropical and subtropical regions. The severity of the disease ranges from a mild asymptomatic infection to death. Leptospirosis is a neglected tropical disease due to the lack of public awareness and health approaches. Therefore, misdiagnosis is common because the symptoms are similar to that of other tropical endemic diseases. The aim of the study was to determine the presence of pathogenic Leptospira in water samples collected from Puerto Rico and Trinidad. Sixty-four environmental water samples were collected throughout …

The Developmental And Behavioral Effects Of Δ9-Tetrahydrocannabinol On A Spastic Mutant, Victoria Mendiola

Master of Science in Integrative Biology Theses

Hyperekplexia is a neurological disorder affecting infants and can be characterized by excessive startle reactions in response to unexpected stimuli. This disease can be modeled in zebrafish in the bandoneon (beo) mutant, where the glrbbmutation results in glycine receptor (GLYR) loss of function glycine receptors and ultimately, improper inhibitory signaling. Though hyperekplexia is a glycinergic-based signaling disorder, disease symptoms are often alleviated with GABA-agonistic benzodiazepines. Exogenous cannabinoids also modulate GABAergic signaling, and THC, one of the natural compounds that prompted the discovery of the endocannabinoid system mimics the effects of endogenous cannabinoids at endocannabinoid and non-cannabinoid sites in the …

Delivering Signal-Altering Bacterial Effector Proteins To Mammalian Cells Using Cell-Penetrating Peptide Technology, Robert Dickson

Master of Science in Integrative Biology Theses

A major role of the mitogen activated protein kinase (MAPK) pathway in eukaryotes is to activate the bacterial pathogen defense response upon the detection of bacterial products in the environment. This defensive signaling results in the induction of inflammation, the transcription of antimicrobial peptides, the modulation of the cell cycle and cell survival. Some Gram-negative bacteria have evolved needle-like structures called Type III Secretion Systems (T3SS) that secrete signal-altering molecules into the host cell to interrupt signaling pathways that would otherwise lead to the elimination of the bacterial infection. These signal-altering molecules are known as bacterial effector proteins (BEPs). Bacterial …

The Development Of Diving Capabilities In Weddell Seal (Leptonychotes Weddellii) Pups Throughout Early Ontogeny, Emma Weitzner

Master's Theses

Weddell seals (Leptonychotes weddellii) are among the deepest diving pinnipeds (i.e., seals, sea lions, and walrus) and one of the best studied marine mammals in the world; as such, these seals are considered a model species for the study of diving physiology and behavior. Adult Weddell seal dive physiology is rather comprehensively understood, yet previous research has excluded an examination of pups’ initial independent diving attempts, beginning instead with the diving capabilities of near-weaning individuals at four to five weeks of age. This is beyond the point many pups have attempted their first independent dives; pups begin to …

Understanding How Map Kinases Influence Endothelial Nitric-Oxide Synthase Activity, Xzaviar Solone

Master of Science in Integrative Biology Theses

Mitogen activated protein kinases (MAPK) p38 and ERK have both been reported to bind endothelial nitric oxide synthase (eNOS) with submicromolar affinity via proposed interactions with a pentabasic non-canonical MAPK binding sequence in the autoinhibitory insertion of eNOS. The neuronal isoform, which lacks the pentabasic motif, did not bind either MAPK significantly. In the present study, the pentabasic motif was validated using predictive modeling programming, and eNOS phosphorylation by MAPKs (P38, ERK and JNK) was examined using in vitro kinase assays and immunoblotting. JNK phosphorylation at Ser¹¹⁴ contrasts with ERK, which phosphorylated Ser⁶⁰⁰, and p38, which phosphorylated …

Play Behavior And The Development Of Boldness And Caution In Juvenile Belding’S Ground Squirrels (Urocitellus Beldingi), Madelene Shehan

Master's Theses

The ubiquity of play among juvenile mammals suggests it provides adaptive benefits, potentially through influences on the development of temperament in young animals. Juvenile Belding’s ground squirrels (Urocitellus beldingi) must balance competing demands for boldness and caution imposed by the fundamental trade-off between their short active season and their vulnerability to predation. In this study, I evaluated whether play helps to facilitate the development of an appropriate balance between boldness and caution in juvenile U. beldingi.I observed the play behavior of juvenile U. beldingiand conducted flight-initiation distance tests to measure boldness-caution at the beginning and toward …

Stress And Body Composition Of Juvenile Alligator Snapping Turtles (Macrochelys Temminckii), Brandon Scott Tappmeyer

MSU Graduate Theses

The alligator snapping turtle (Macrochelys temminckii), is a species of conservation concern that is the subject of multiple head-start and reintroduction efforts across its range. In captive propagation programs, producing offspring that are in optimal physiological condition maximizes the likelihood of success after release. The purpose of my study was to compare stress and body composition between one free-ranging reintroduced population and two captive populations. The two captive populations were both housed in southern Oklahoma, but one group was reared indoors whereas the other inhabited outdoor ponds at a national fish hatchery. I used circulating glucocorticoid (corticosterone) concentrations as an …

The Role Of Reactive Oxygen Species In Crotalus Atrox Venom-Induced Cell Death, Lindsay Brown

Master of Science in Integrative Biology Theses

Venomous snake bites impact humans all around the world. Anti-venom treatments mitigate systemic effects such as vascular hemorrhage, platelet aggregation inhibition, and the activation of inflammatory mediators. However, hemorrhagic snake venom also causes a loss of cellular adhesion to extracellular matrix components resulting in massive local tissue damage. To better understand the mechanism in which venom induces local tissue damage, human embryonic kidney cells (HEKS) were grown on PEI then stimulated with 500μg/ml Crotalus atrox (CA) venom for 4 and 10 hours. Alamar Blue assays were used to measure cell viability and results suggest a 15±8.6% (p<0.05) and 59±10.7% (p<0.05) reduction in cell viability at 4 and 10 hours, respectively. Cells stimulated with 500μg/ml venom for 10 hours stained 98±2.2% (p<0.05) positive for Trypan blue, suggesting the venom reduces membrane integrity. Identical treatment in the presence of 200 units PEG-catalase (PC) increased viability by 37±5.7% (p>0.001) compared to …

Landscape Pattern And Wild Bee Communities In Maine, Brianne Du Clos

Electronic Theses and Dissertations

Commercial production of lowbush blueberry (Vaccinium angustifolium Aiton) in Maine relies primarily on managed honeybee hives; however, naturally occurring wild bees are more efficient pollinators of the crop. Wild bees have short foraging distances and must nest near crop fields to provide pollination services. After crop bloom, the surrounding landscape must provide sufficient forage to maintain wild bee populations for the remainder of the growing season. Lowbush blueberries in Maine are produced in a mixed-use landscape with two distinct landscape contexts. Here, we document bee communities and habitat resources (nesting and floral) in power line rights-of-way and eight land …

Fungi In A Hot, Dry, Changing World, Miriam I. Hutchinson

Biology ETDs

My doctoral work focused on understanding the reciprocal relationship between fungi and their environment, namely how fungi respond to environmental flux, as well as how fungi can modify and structure their habitats, especially in the context of climate change. As such, I aimed my research on fungi with distinct adaptations to their environmental niches: endophytic fungi that inhabit plant tissue and thermophilic fungi that are capable of growing at the upper temperature limit for eukaryotic life. My research consisted of three studies. First, I investigated the thermophilic species Myceliophthora heterothallica to demonstrate its use as a model organism for efficient …

Development Of A Long-Acting Nanoformulation Of Dolutegravir For Prevention And Treatment Of Hiv-1 Infection, Brady Sillman

Theses & Dissertations

Dolutegravir (DTG) is a potent human immunodeficiency virus type 1 (HIV-1) integrase strand-transfer inhibitor (INSTI) with a high barrier to viral drug resistance. However, opportunities to improve its profile abound. These include extending the drug’s apparent half-life, increasing penetrance to “putative” viral reservoirs, and reducing inherent toxicities. These highlight, in part, the need for long-acting, slow effective release antiretroviral therapy (LASER ART) delivery schemes. A long-acting (LA) DTG was made by synthesizing a hydrophobic and lipophilic prodrug encased with poloxamer (P407) surfactant. This modified DTG (MDTG) reduced systemic metabolism and polarity, increased lipophilicity and membrane permeability, improved encapsulation, and formed …

Differentiating Black Bears (Ursus Americanus) And Brown Bears (U. Arctos) Using Linear Tooth Measurements And Identification Of Ursids From Oregon Caves National Monument, Emily Bogner

Electronic Theses and Dissertations

North American black bears and brown bears can be difficult to distinguish in the fossil record due to similar dental and skeletal morphologies. Challenges identifying ursid material from Oregon Caves National Monument (ORCA) called for an accurate tool to distinguish the species. This study utilized a large database of lower tooth lengths and ratios in an attempt to differentiate black and brown bears in North America. Further, this project examined how these linear measurements differ geographically. Analysis of variance (ANOVA) found significant differences between black and brown bears from across North America for every variable studied. Stepwise discriminant analyses (DA) …

Observations And Applications Of Husbandry Methodologies On A Backyard Poultry Farm In Dangriga, Belize, Bailey Carpenter

Animal Science Undergraduate Honors Theses

This study explores the husbandry methodologies on a backyard poultry farm in Dangriga, Belize, with the purpose of producing a set of guidelines for backyard poultry growers that have limited resources in similar regions. The majority of data collection occurred through survey questions approved by the IRB, necropsies approved by IACUC, and general observations. There has been a steady increase in poultry production in developing regions due to its positive effects on income and relative nutrition. However, due to a lack of accessible communication and education regarding effective and safe poultry production, these operators typically see poor productivity and/or profitability …