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Articles 1 - 26 of 26
Full-Text Articles in Endocrinology
The Energetics Of Seasonality In Wild Diademed Sifaka (Propithecus Diadema): A Technical And Biological Validation Of Fecal Triiodothyronine Radioimmunassay, Casey Farmer
Graduate Research Theses & Dissertations
The energetic state of an animal has vital consequences for its fitness, but it can be difficult to detect through behavioral observations. The development of techniques to determine an animals’ energetic state non-invasively would allow conservation planners to rapidly assess the energy balance and conservation potential of individuals, groups, and populations. Thyroid hormones like triiodothyronine (T3) regulate and reflect metabolic state in mammals. T3 is a non-invasive biomarker that can be detected in feces and could potentially be used for this purpose. I perform the first validation of a commercially available T3 radioimmunoassay designed for humans on a wild strepsirrhine …
An Argument For The Utilization Of Amphibian Stress As An Indicator Of Wetland Condition, Andrew W. Sisson
An Argument For The Utilization Of Amphibian Stress As An Indicator Of Wetland Condition, Andrew W. Sisson
Honors College Theses
Traditional forms of rapid wetland condition assessments focus on foliage health, nutrient enrichment, chemical contamination, and surrounding land usage, often overlooking an evaluation of the animals living in the wetland. More intense assessments include the National Wetland Condition Assessment (NWCA) and indices of biotic integrity, which focus on community composition (e.g., diversity and species richness) and abundances. These indices require expertise in species identification and do not provide information about the animal’s fitness. Animal stress physiology, which generally correlates with measures used to quantify animal fitness (e.g., survival, reproduction, and body condition), may provide a complementary rapid assessment method aimed …
Unveiling The Ancestral Function Of A Neuroendocrine Regulator, Pou-I/Pit1: Insights From Gene Expression Analysis In The Sea Anemone Nematostella Vectensis, Miguel Agostinho Pina Da Silva
Unveiling The Ancestral Function Of A Neuroendocrine Regulator, Pou-I/Pit1: Insights From Gene Expression Analysis In The Sea Anemone Nematostella Vectensis, Miguel Agostinho Pina Da Silva
Graduate Theses and Dissertations
Cnidaria (i.e., sea anemones, jellyfish, corals) and Bilateria (i.e., vertebrates, sea stars, fruit flies), are sister groups that diverged around 600 million years ago. Despite the long evolutionary time, many cellular differentiation mechanisms, cell types, tissues and behaviors are conserved. Such as neurons, mechanosensory hair cells, feeding behaviors, peristaltic movements, and sleep. Recent advances in genomics, molecular biology and microscopy have fueled an increased interest in understanding cnidarian nervous and neuroendocrine systems. Understanding the developmental mechanisms and the mode of operation of Cnidarian nervous systems helps to reconstruct the ancestral nervous system of the last common ancestor of Cnidaria and …
Does Stress Physiology Mediate Disease Resistance In The Arizona Tiger Salamander (Ambystoma Mavortium Nebulosum)?, Megan Zerger
Does Stress Physiology Mediate Disease Resistance In The Arizona Tiger Salamander (Ambystoma Mavortium Nebulosum)?, Megan Zerger
2023 Midwest Ecology & Evolution Conference
Amphibian biodiversity has greatly diminished in recent years due to disease. Panzootic pathogenic fungi Batrachochytrium dendrobatidis (Bd) causes the deadly disease chytridiomycosis (chytrid), a primary driver of catastrophic global amphibian declines and extinctions. The pathogenesis of chytrid is still unclear, as certain species and individuals within a species are differentially affected. Susceptibility and mortality of Bd are influenced by prolonged chronic stress. Prolonged glucocorticoid activity deleteriously affects many of the same physiological processes as Bd infections, and corticosterone is the primary glucocorticoid released by amphibians in response to stress. Thus, the objective of our study is to assess …
The Use Of A Habitat Quality Stress Index To Evaluate Stress As An Analog For Proximate Fitness In The American Crow Within A Matrix Of Landcover Characteristics To Assess Its Potential Contribution To Disease Etiologies, Theodore Lee Grabarz
Antioch University Dissertations & Theses
All organisms occur within spatial and temporal environments to maximize proximate fitness (health) and thus life history outcomes. Previous work has examined the temporal and behavioral aspects of proximate fitness on life history outcomes particularly regarding highly perturbed environments (i.e., climate and land use change, resource extraction, agricultural erosion, etc.). My work focuses on the less examined spatial aspect of these perturbed environments. More specifically, this dissertation examines habitat selection and quality as the basis for understanding stress response (negative and positive feedback mechanisms) to environmental stressors within the larger context of regional or gamma (ɣ) biodiversity. Through the lens …
Effects Of Social Context On Salivary Cortisol And Attention In Tufted Capuchins (Cebus [Sapajus] Apella), Andrew Desana
Effects Of Social Context On Salivary Cortisol And Attention In Tufted Capuchins (Cebus [Sapajus] Apella), Andrew Desana
Master’s Theses
Social context alters cognitive performance, but the mechanisms for this remain unclear. One possibility is that stressors associated with social contexts mediate changes in cognitive performance by influencing attention. We conducted two experiments to investigate how social context affects performance on an attention task in capuchin monkeys (Cebus [Sapajus] apella). We additionally validated and measured physiological stress through salivary cortisol. In experiment one, capuchins were exposed to three conditions where they were either isolated or paired with an affiliative or agonistic social partner separated by a barrier. In experiment two, subjects received affiliative and agonistic conditions without barriers to allow …
Relationships Between Behavior, Energy Metabolites, And Corticosterone In Black-Legged Kittiwake (Rissa Tridactyla) Nestlings, Sierra Pete
Master’s Theses
Birds can cope with energy-shifting challenges by redirecting energy and behavior to maintain energetic homeostasis. Nestlings allocate energy to support their rapid growth and developmental period; thus, their challenges and the subsequent energetic demands can be much different than an adult. At a baseline level, energy is constantly shifting in response to regularly occurring challenges; however, more substantial challenges can initiate the production of glucocorticoid hormones. In birds, the main glucocorticoid is corticosterone. Corticosterone is believed to aid in energy homeostasis by redirecting energy metabolite mobilization. Energy metabolites are intermediaries or end products of cellular metabolism, thus, metabolites like glucose …
Importance Of The Microhabitat And Microclimate Conditions In The Northern Gray-Cheeked Salamander (Plethodon Montanus) Across An Elevation Gradient, Trevor Chapman
Electronic Theses and Dissertations
The southern Appalachian Mountains have among the highest salamander diversity in the world, largely due to local speciation in the family Plethodontidae. Plethodontid salamanders (i.e., lungless salamanders) are particularly sensitive to habitat climate conditions due to their reliance on cutaneous respiration, and their immediate environmental conditions (microhabitat) likely influence their dispersion and activity more than the large-scale atmospheric conditions. The Northern Gray-cheeked salamander (Plethodon montanus) is restricted to high elevations in the Appalachian Mountains. Our goal was to investigate the relationship between P. montanus and its microhabitat by examining behavioral preference for climatic conditions, characterizing the microclimate with …
Effects Of Melatonin Implantation On The Activity Levels Of Captive Snow Buntings (Plectrophenax Nivalis), Zoë Ward
Mahurin Honors College Capstone Experience/Thesis Projects
In vertebrates, melatonin regulates many components of the circadian rhythm; depending on the organism’s location and time of year, the pineal gland will produce melatonin accordingly, controlling the sleep-wake cycle and breeding physiologies. However, locations at the poles in which the sun is above the horizon for multiple days at a time pose unique challenges for the organisms living there. The goal of this study was to examine how the implantation of melatonin in an arctic-breeding songbird affects its activity levels and circadian rhythm. The subject of this study, the snow bunting (Plectrophenax nivalis), is a small songbird …
James Davidson Fawcett (1933–2020): Imbibing With The Kiwi, Louis A. Somma
James Davidson Fawcett (1933–2020): Imbibing With The Kiwi, Louis A. Somma
Papers in Herpetology
An obituary and summary of the life of James D. Fawcett (1933-2020), herpetologist and instructor and professor of Biology at University of Nebraska at Omaha, 1972-2015. Includes bibliography of his works, list of master's theses chaired, and recollections of former students.
Morph- And Sex-Specific Differences In Corticosterone Of The Arizona Tiger Salamander (Ambystoma Mavortium Nebulosum), Megan Zerger
Morph- And Sex-Specific Differences In Corticosterone Of The Arizona Tiger Salamander (Ambystoma Mavortium Nebulosum), Megan Zerger
Scholars Week
Life history morph, sex, and body condition are traits that may influence stress within salamander populations because of differences in physiology and environmental conditions. Given widespread declines and the effects chronic stress can have on amphibian health, it is important to understand within-population drivers of stress and how population level variation may influence population viability. Thus, the objective of our study was to assess how corticosterone varies within the Arizona tiger salamander (Ambystoma mavortium nebulosum) population at the Mexican Cut Nature Preserve. We used a non-invasive skin swabbing method to collect baseline and elevated corticosterone from paedomorph (aquatic …
Monitoring Relationships Between Corticosterone And Snake Fungal Disease In Timber Rattlesnakes (Crotalus Horridus) In Western Kentucky, John Bromley Hewlett
Monitoring Relationships Between Corticosterone And Snake Fungal Disease In Timber Rattlesnakes (Crotalus Horridus) In Western Kentucky, John Bromley Hewlett
Murray State Theses and Dissertations
Over the past four decades, emergent fungal diseases have been the most devastating relative to species declines and extinctions. While most research has focused on fungal diseases affecting amphibians and bats, less has focused on diseases like snake fungal disease (SFD), caused by Ophidiomyces ophiodiicola (Oo). SFD was first described in 2006 in North America within a Timber rattlesnake (Crotalus horridus) population in New Hampshire. Since then SFD has been documented in 19 US states, one US territory (Puerto Rico), and Europe. SFD causes high mortality in some species, including the Eastern Massasauga rattlesnakes (Sistrurus …
The Effects Of Food Supply On Reproductive Hormones And Timing Of Reproduction In An Income-Breeding Seabird, Shannon Whelan, Scott A. Hatch, Z. Morgan Benowitz-Fredericks, Charline Parenteau, Olivier Chastel, Kyle Elliott
The Effects Of Food Supply On Reproductive Hormones And Timing Of Reproduction In An Income-Breeding Seabird, Shannon Whelan, Scott A. Hatch, Z. Morgan Benowitz-Fredericks, Charline Parenteau, Olivier Chastel, Kyle Elliott
Faculty Journal Articles
Current food supply is a major driver of timing of breeding in income-breeding animals, likely because increased net energy balance directly increases reproductive hormones and advances breeding. In capital breeders, increased net energy balance increases energy reserves, which eventually leads to improved reproductive readiness and earlier breeding. To test the hypothesis that phenology of income-breeding birds is independent of energy reserves, we conducted an experiment on food-supplemented (“fed”) and control female black-legged kittiwakes (Rissa tridactyla). We temporarily increased energy costs (via weight handicap) in a 2 × 2 design (fed/unfed; handicapped/unhandicapped) during the pre-laying period and observed movement …
Influence Of Testosterone On Male-Male Competition In The Red-Sided Garter Snake, Thamnophis Sirtalis Parietalis, Isabella M. G. Bukovich
Influence Of Testosterone On Male-Male Competition In The Red-Sided Garter Snake, Thamnophis Sirtalis Parietalis, Isabella M. G. Bukovich
Senior Honors Projects, 2020-current
Female mimicry in the red-sided garter snake, Thamnophis sirtalis parietalis, is described in several well-studied evolutionary advantages, but an aspect that remains elusive is how reproductive traits are linked to the 3-fold higher circulating androgens in males with this phenotype. In this study, we implanted male garter snakes (n=15 per group) with either a blank implant (SHAM; control) or a T implant, the latter simulating the female mimic phenotype. Following simulated low-temperature dormancy, males were scored for courtship intensity over three days of behavioral trials with females housed in the same facility. Males were sacrificed, and sperm were collected …
The Effect Of Intensified Illuminance And Artificial Light At Night On Fitness And Susceptibility To Abiotic And Biotic Stressors, Grascen Shidemantle
The Effect Of Intensified Illuminance And Artificial Light At Night On Fitness And Susceptibility To Abiotic And Biotic Stressors, Grascen Shidemantle
Biological Sciences Student Scholarship
Changing light conditions due to human activities represents an important emerging environmental concern. Although changes to natural light conditions can be independently detrimental, in nature, organisms commonly face multiple stressors. To understand the consequences of altered light conditions, we exposed a model amphibian (wood frog; Lithobates sylvaticus) to a control and two anthropogenic light conditions: intensified daytime illuminance and artificial light at night - ALAN (intensified daytime illuminance + extended photoperiod). We measured (1) metrics of fitness (hatching success as well as survival to, size at, and time to metamorphosis) (2) susceptibility (time to death) to a commonly cooccurring anthropogenic …
Impact Of Nacl Tolerance On The Stress Physiology And Fitness Of Larval Wood Frogs (Rana Sylvatica), Grascen Shidemantle, Nicholas Buss, Jessica Hua
Impact Of Nacl Tolerance On The Stress Physiology And Fitness Of Larval Wood Frogs (Rana Sylvatica), Grascen Shidemantle, Nicholas Buss, Jessica Hua
Biological Sciences Student Scholarship
No abstract provided.
Stress And Body Composition Of Juvenile Alligator Snapping Turtles (Macrochelys Temminckii), Brandon Scott Tappmeyer
Stress And Body Composition Of Juvenile Alligator Snapping Turtles (Macrochelys Temminckii), Brandon Scott Tappmeyer
Graduate Theses/Dissertations
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 …
Population Health Of Spotted Salamanders (Ambystoma Maculatum) In Created Vernal Pools: An Integrative Approach, Alice R. Millikin
Population Health Of Spotted Salamanders (Ambystoma Maculatum) In Created Vernal Pools: An Integrative Approach, Alice R. Millikin
Graduate Theses, Dissertations, and Problem Reports (ETD)
Habitat creation is an important tool for conservation to counteract habitat loss and degradation. Vernal pools are susceptible to destruction due to limited detection, protection, and regulation. These wetlands provide fishless breeding habitat for many amphibian species including spotted salamanders (Ambystoma maculatum) in eastern North America. Determining whether created vernal pool habitat is successful is often determined by demographic data of colonizing populations. I suggest that hormone levels, population genetics, and disease prevalence can improve our understanding of population health in created habitat. The goal of this dissertation was to assess the health of spotted salamander larvae in …
Consequences Of Porcine Zona Pellucida Immunocontraception To Feral Horses, Cassandra M.V. Nuñez
Consequences Of Porcine Zona Pellucida Immunocontraception To Feral Horses, Cassandra M.V. Nuñez
Human–Wildlife Interactions
Porcine zona pellucida (PZP) immunocontraception was developed to provide a more humane, effective, and inexpensive method of population regulation for wildlife species. It has been used to regulate populations of several species including white tailed deer (Odocoileus virginianus), elk (Cervus elaphus ), black bear (Ursus americanus ), and the feral horse (Equus ferus caballus) with varying levels of success. Early studies on Assateague Island National Seashore, Maryland, USA, suggested PZP was as an ideal form of fertility control because it reduced the likelihood of conception to
Organizational Effects Of Defeminizing Toxicants: Lessons Learned From An Environmental Sentinel Organism, The Fathead Minnow., Jonathan Ali
Organizational Effects Of Defeminizing Toxicants: Lessons Learned From An Environmental Sentinel Organism, The Fathead Minnow., Jonathan Ali
Theses & Dissertations
Endocrine disrupting compounds (EDCs) are chemicals that interfere with hormone function and are increasingly detected in aquatic environments, where they elicit adverse effects from exposed organisms. The toxicological effects of EDCs can be described as either activational (reversible) or organizational (irreversible), where the latter are associated with adverse outcomes in reproductive performance of adult fish. However, few studies have investigated the organizational impacts of anti-estrogenic or “defeminizing” EDCs, e.g. agrichemicals or pharmacological agents, in an environmentally-relevant or “sentinel” species. The objective of this study was to investigate the impacts of early-life EDC-initiated changes in estrogenic gene expression on organizational effects …
Acute Salivary Steroid Hormone Responses During Coalitional And Dyadic Competitions In Hong Kong Juvenile Children, Timothy Mchale
Acute Salivary Steroid Hormone Responses During Coalitional And Dyadic Competitions In Hong Kong Juvenile Children, Timothy Mchale
UNLV Theses, Dissertations, Professional Papers, and Capstones
A large body of research links testosterone and cortisol responses to competition during adulthood. Little psychoneuroendocrine research has explored salivary steroid hormone responses to competition during middle childhood. This project investigated the relationship between acute salivary steroid hormone change, performance, competitor type, and outcome effects in three different field studies, while controlling for Body Mass Index (BMI) and pubertal development, in a population of ethnically Chinese, Hong Kong juvenile children, 8-11 years of age. The relative dynamics of salivary steroid change were assessed during a 1) coalitional physical competition (soccer) in boys, 2) a non-physical mixed-sex coalitional competition (math contest), …
Glucocorticoids And Parental Effort In Tree Swallows (Tachycineta Bicolor), Mackenzie Prichard
Glucocorticoids And Parental Effort In Tree Swallows (Tachycineta Bicolor), Mackenzie Prichard
Undergraduate Theses, Professional Papers, and Capstone Artifacts
All vertebrates respond to stressful situations through the release of hormones called glucocorticoids (CORT). These hormones alter processes within the body to prioritize long term survival over immediate reproduction. It is hypothesized that this is helps individuals survive until conditions become more favorable for successful reproduction. Historically, stress was hypothesized to primarily to pull organisms out of reproductive life history stages when unfavorable conditions made offspring survival slim (otherwise known as the “CORT-tradeoff hypothesis”). However, recent evidence suggests that birds actively feeding nestlings show elevated CORT levels, possibly due to the increased metabolic demands of parenthood. This relationship has been …
Sea Turtle Hatchling Sex Ratios Determined Via Hormone Assay: Implications Of Climate Change?, William A. Hilton, Matthew Godfrey, Camryn D. Allen
Sea Turtle Hatchling Sex Ratios Determined Via Hormone Assay: Implications Of Climate Change?, William A. Hilton, Matthew Godfrey, Camryn D. Allen
STAR Program Research Presentations
Currently all species of sea turtles are listed as threatened or endangered with extinction under the U.S. Endangered Species Act. Due to their status, sea turtle conservation is a high priority for the U.S. National Marine Fisheries Service and U.S. Fish and Wildlife Service. One major challenge conservationists face is the lack of a noninvasive, cost efficient method for determining the sex of hatchling sea turtles. Because secondary sex characteristics (i.e. males have longer tails) are not evident until turtles start to reach sexual maturity, the sex of hatchlings is not easily determined. The least invasive way to determine the …
Development Of Neuroendocrine Components Of The Thyroid Axis In The Direct-Developing Frog Eleutherodactylus Coqui: Formation Of The Median Eminence And Onset Of Pituitary Tsh Production., David H. Jennings, Bryce Evans, James Hanken
Development Of Neuroendocrine Components Of The Thyroid Axis In The Direct-Developing Frog Eleutherodactylus Coqui: Formation Of The Median Eminence And Onset Of Pituitary Tsh Production., David H. Jennings, Bryce Evans, James Hanken
SIUE Faculty Research, Scholarship, and Creative Activity
Direct-developing frogs lack, wholly or in part, a wide range of larval features found in metamorphosing species and form adult-specific features precociously, during embryogenesis. Most information on thyroid regulation of direct development relies on hormone manipulations; the ontogeny of many thyroid axis components has not been fully described. This analysis examines differentiation of the median eminence of the hypothalamus and production of thyroid-stimulating hormone (TSH) by the pituitary of the direct-developing frog Eleutherodactylus coqui. The median eminence is established two-thirds of the way through embryogenesis. Cells immunoreactive to human TSHb antibodies are first detected during embryogenesis and quantitative changes in …
The Relationship Between 11-Ketotestosterone, Cortisol, And Testosterone And Condition Index For Poecilia Reticulata, Shelly Gupta, Brandy G. Kalbach
The Relationship Between 11-Ketotestosterone, Cortisol, And Testosterone And Condition Index For Poecilia Reticulata, Shelly Gupta, Brandy G. Kalbach
Biological Sciences
The guppy, Poecilia reticulata, is a common study organism for behavioral and other ecological experiments (Houde, 1997). As far as we know, no previous data have been compiled regarding hormones and condition index of guppies. In this experiment we examined the relationship between circulating levels of three hormones (testosterone, 11-ketotestosterone and cortisol) and condition index in males and also made comparisons among the hormone levels, for three guppy sites from the northern range of Trinidad – Aripo River, Marianne River and Small Crayfish River. Hormone samples were obtained using non-invasive water borne techniques and quantified by our collaborator. The condition …
Immune-Endocrine Interactions In The Lizard Sceloporus Undulatus Hyacinthinus: Testing An Assumption Of The Immunocompetence Handicap Hypothesis, Mukta Chakraborty
Immune-Endocrine Interactions In The Lizard Sceloporus Undulatus Hyacinthinus: Testing An Assumption Of The Immunocompetence Handicap Hypothesis, Mukta Chakraborty
All-Inclusive List of Electronic Theses and Dissertations
The immunocompetence handicap hypothesis (IHH) was proposed by Folstad and Karter ( 1992) to describe the role of the endocrine system in ensuring honesty of sexual signaling. Numerous studies have investigated the assumptions of the IHH, but currently there is mixed evidential support in favor of the IHH. The first chapter of this thesis is a review examinining these studies, their limitations, and proposed alternative models and future directions. The second chapter of this thesis presents a study in which we experimentally assesss the testosterone immunosuppression assumption in adult male Sceloporus undulatus lizards. We manipulated circulating androgen levels (Day 0) …