Energetic Cost And Physiological Trade-Offs,
2021
Florida International University
Energetic Cost And Physiological Trade-Offs, Heba A. Ali
FIU Electronic Theses and Dissertations
Understanding how organisms allocate limited resources across physiological systems is a major challenge in biology. This study revealed that high energetic demand of electric signals of male electric fish (Brachyhypopomus gauderio) is matched by a metabolic trade-off with other cellular functions. We used thyroxine (T4) to modulate the fish’s signal metabolism, partitioned the energy budget pharmacologically, and measured energy consumption using oxygen respirometry. In males, total energy consumption was unchanged pre- and post-T4 treatment, while signal metabolism rose and the standard metabolic rate fell in an even trade-off. Total metabolism in females did the opposite. Under T4, the …
Scaling Of Computed Tomography Body Composition To Height: Relevance Of Height-Normalized Indices In Patients With Colorectal Cancer,
2021
LSU Health Sciences Center - New Orleans
Scaling Of Computed Tomography Body Composition To Height: Relevance Of Height-Normalized Indices In Patients With Colorectal Cancer, Justin C. Brown, Steven B. Heymsfield, Bette J. Caan
School of Medicine Faculty Publications
Background: Body weight scales to height with a power of ≈2 (weight/height2), forming the basis of body mass index (BMI). The corresponding scaling of body composition measured by abdominal computed tomography (CT) to height has not been established. The objective of this analysis was to quantify the scaling of body composition measured by a single-slice axial abdominal CT image (skeletal muscle, and visceral, subcutaneous, and total adipose tissue) to height in patients with colorectal cancer (CRC). Methods: This cross-sectional study included non-Hispanic white males and females, aged 18–80 years, who were diagnosed with stage I–III CRC at an integrated health …
Exploring Β-Cell Function And Heterogeneity In Obese Sm/J Mice,
2021
Washington University in St. Louis
Exploring Β-Cell Function And Heterogeneity In Obese Sm/J Mice, Mario Alejandro Miranda
Arts & Sciences Electronic Theses and Dissertations
Pancreatic β-cells perform glucose-stimulated insulin secretion, a process required to maintain systemic glucose homeostasis. Obesity promotes glycemic and inflammatory stress, causing β-cell death and dysfunction, resulting in diabetes. Efforts to improve β-cell function in obesity have been hampered by observations that β-cells are highly heterogeneous, varying in morphology, function, and gene expression. There is great need to understand the breadth of β-cell heterogeneity in health and obesity to improve diabetic therapies.High fat-fed SM/J mice spontaneously transition from hyperglycemic-obese to normoglycemic-obese with age, providing a unique opportunity to study β-cell adaptation. Here, we show that as they resolve hyperglycemia, obese SM/J …
Modulation Of Glucose Homeostasis By Nucleotide P2y2 Receptor And Biological Sex,
2021
Missouri State University
Modulation Of Glucose Homeostasis By Nucleotide P2y2 Receptor And Biological Sex, Hailee Anne Marino
MSU Graduate Theses
Recent insights into the pathological role of Nucleotide P2Y2 receptor suggest P2Y2R involvement in high fat diet-induced obesity and potentiates insulin resistance. However, these recent insights do not demonstrate how P2Y2R modulates glucose homeostasis under physiological conditions. Further, it remains unknown how sex biological factors influence P2Y2R receptor signaling in the regulation of glucose homeostasis. The research objective for the present study is to elucidate the novel roles of P2Y2 in fasting blood glucose and glucose tolerance (basal insulin sensitivity) under resting conditions in males and females. We expected that under physiological …
Temperature-Induced Activation Of The Reproductive Axis Through Melatonin-Mediated Changes In Thyrotropin,
2021
Portland State University
Temperature-Induced Activation Of The Reproductive Axis Through Melatonin-Mediated Changes In Thyrotropin, Treven J. Winters
Dissertations and Theses
An animal's ability to synchronize life-history events or stages with optimal environmental conditions is paramount to successfully reproducing and maximizing fitness. Additional events including migration, foraging, rearing of young, and emergence from hibernation are all examples of processes under environmental control in one species or another. An exciting new mechanism involving neural thyroid hormone metabolism has been elucidated that links environmental control to the neuroendocrine reproductive axis. In birds and mammals with seasonal breeding cycles, this neuroendocrine pathway is activated by photoperiod-induced changes in thyroid stimulating hormone (TSH, also known as thyrotropin) production within the pars tuberalis region of the …
Computational Analysis Of Type 3 Iodothyronine Deiodinase: Potential Inhibitors, Substrate Binding, And Dimer Structure,
2021
Old Dominion University
Computational Analysis Of Type 3 Iodothyronine Deiodinase: Potential Inhibitors, Substrate Binding, And Dimer Structure, Eric Scott Marsan
Chemistry & Biochemistry Theses & Dissertations
Thyroid hormones (THs) in mammalian tissues are crucial for development and maintaining metabolic homeostasis. Iodothyronine deiodinases (Dios) remove iodines from THs by a selenocysteine (Sec) residue, which either activates or inactivates them. Halogen bonding (XB) has been proposed to describe the interaction between the Se and I atoms of the T4-Dio complex. Disruption of TH homeostasis by xenobiotics, such as polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) can cause deleterious effects on the endocrine system. Experimental studies have indicated that PBDEs and PCBs could disrupt TH homeostasis by inhibiting Dio through XB formation. However, no current quantitative study exists …
James Davidson Fawcett (1933–2020): Imbibing With The Kiwi.,
2021
University of Nebraska - Lincoln
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.
Validation Of A Novel Trpm8 Knockout Mouse Model,
2021
University of Southern Maine
Validation Of A Novel Trpm8 Knockout Mouse Model, Bilan Mohamed
Thinking Matters Symposium
Recent studies suggest that the use of thermoregulatory treatments that affect brown fat may help curb obesity. However it is unknown how these treatments may affect bone homeostasis. Our work has focused on the transient receptor potential melastatin (TRPM8) protein, which is responsible for detecting colder temperatures in sensory neurons. Previous work within the Motyl laboratory has found that Trpm8 plays a role in bone acquisition. Mice with a global deletion of the Trpm8 gene have reduced trabecular bone volume fraction due to reduced bone formation by osteoblasts. However, it is unclear whether sensory neuron or osteoblast-mediated expression of Trpm8 …
Morph- And Sex-Specific Differences In Corticosterone Of The Arizona Tiger Salamander (Ambystoma Mavortium Nebulosum),
2021
Murray State University
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 …
Role Of Na/K-Atpase Non-Enzymatic Signaling In Renal Proximal Tubule Sodium Transport,
2021
Marshall University
Role Of Na/K-Atpase Non-Enzymatic Signaling In Renal Proximal Tubule Sodium Transport, Shreya Tapan Mukherji
Theses, Dissertations and Capstones
The renal proximal tubule (RPT) is the center stage for renal handling of Na+ , a potent determinant of systemic Na+ and volume homeostasis in health and disease. In the RPT, through its classic ion-pumping function, Na + /K+ -ATPase (NKA) generates the Na+ gradient that drives apical Na+ absorption, mostly through Na+ /H+ exchanger (NHE3). In contrast, pharmacological evidence suggests that the activation of the NKA non-enzymatic signaling function, through Src and other signaling partners, triggers a cellular redistribution of NKA and NHE3 that decreases transcellular Na+ flux in cultured RPT cells. However, the physiological relevance of the nonenzymatic …
Effect Of Acute Sleep Fragmentation Upon Inflammatory Response Of Brown And White Adipose Tissue In Male Mice,
2021
Western Kentucky University
Effect Of Acute Sleep Fragmentation Upon Inflammatory Response Of Brown And White Adipose Tissue In Male Mice, Zach Wriedt
Mahurin Honors College Capstone Experience/Thesis Projects
Sleep is an important process required for vertebrates, including humans, to function. When sleep is disrupted, it leads to deleterious effects such as inflammatory responses throughout the body. Past studies have shown that acute (24 h) sleep fragmentation (SF) leads to an inflammatory response in white adipose tissue. However, whether brown adipose tissue responds in a similar fashion is unknown. Male adult (>8 weeks of age) C57BL/6j mice were subjected to SF for 24 h using a cage outfitted with a bar that moves horizontally across the cage every 2 min to periodically awaken mice (N =10). Controls were …
Estrogen Disruption Of Hypothalamic Neural Activity,
2021
Cal Poly Humboldt
Estrogen Disruption Of Hypothalamic Neural Activity, Princess Dickson
Cal Poly Humboldt theses and projects
The brain is highly dependent on the endocrine system for proper neurodevelopment, as it plays a key role in many biological processes. Bisphenol A is a chemical found in plastics that has the potential to mimic the effects of Estrogen in the body, at least weakly. People interact with plastic that contains BPA regularly, and people are at risk for exposure even before being born. The abundance of BPA, along with other exogenous estrogens, makes examining the relationship between early exposure and changes in brain activity imperative. The current study aims to establish a relationship between disrupted estrogen function and …
Characterization Of The Whale Shark (Rhincodon Typus) Melanocortin-2 Receptor,
2021
University of Denver
Characterization Of The Whale Shark (Rhincodon Typus) Melanocortin-2 Receptor, Brianne Hoglin
Electronic Theses and Dissertations
Among bony vertebrates, the melanocortin-2 receptor ortholog is unique among the family of five melanocortin receptors on the basis that it is dependent on its accessory protein, MRAP1, for trafficking and activation, and is selective for activation by ACTH alone. Previous studies on the MC2R orthologs of select cartilaginous fish, the elephant shark (Callorhinchus milii) and the red stingray (Dasyatis akajei), revealed divergent traits in a less obligatory relationship on MRAP1 and its ability to be activated by ACTH or the MSH-sized peptides. However, observed traits were not consistent between these two cartilaginous fish species, posing …
Monitoring Relationships Between Corticosterone And Snake Fungal Disease In Timber Rattlesnakes (Crotalus Horridus) In Western Kentucky,
2021
Murray State University
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,
2021
McGill University
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 …
Transcriptional Programming By Thyroid Hormone Receptor Beta Maintains Normal Cell Identity And Suppresses Tumor Growth,
2021
University of Vermont
Transcriptional Programming By Thyroid Hormone Receptor Beta Maintains Normal Cell Identity And Suppresses Tumor Growth, Noelle Elizabeth Gillis
Graduate College Dissertations and Theses
The overall incidence of thyroid cancer has more than tripled over the past several decades, as has aggressive disease and mortality. The direct relationship between thyroid disease, thyroid hormone levels, and development of thyroid cancer is incomplete. Recent meta-analyses have indicated a higher risk of thyroid cancer for patients with thyroid diseases that reflect an altered thyroid-pituitary signaling axis, which can have profound impacts on the physiology of the thyroid gland. These largely unanswered questions regarding altered thyroid hormone signaling and its consequences for thyroid tumor growth present a significant clinical challenge. This dilemma may come from a lack of …
Influence Of Testosterone On Male-Male Competition In The Red-Sided Garter Snake, Thamnophis Sirtalis Parietalis,
2020
James Madison University
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 …
Circadian Regulation Of The Timing Of Pre-Ovulatory Luteinizing Hormone Surge In Mice And Hamsters,
2020
University of Massachusetts Amherst
Circadian Regulation Of The Timing Of Pre-Ovulatory Luteinizing Hormone Surge In Mice And Hamsters, Ajay Kumar
Doctoral Dissertations
Endogenous daily (circadian) oscillators ensure the proper timing of physiological and behavioral processes that are essential to health. A set of core clock genes and their protein products function in transcriptional/translational feedback loops (TTFLs) that time and coordinate vital homeostatic, cognitive, and hormonal processes. A master pacemaker in the suprachiasmatic nucleus (SCN) coordinates circadian function throughout the organism. Investigating the causal role of genetically defined cell types in the suprachiasmatic nucleus for circadian rhythms is essential to understand how an animal’s physiology is temporally organized. This thesis explores the role of molecular clocks within particular cell types in regulating physiology. …
Sexually Dimorphic Oxytocin Receptor-Expressing Neurons In The Anteroventral Periventricular Nucleus Regulates Maternal Behavior,
2020
Louisiana State University and Agricultural and Mechanical College
Sexually Dimorphic Oxytocin Receptor-Expressing Neurons In The Anteroventral Periventricular Nucleus Regulates Maternal Behavior, Kaustubh Sharma
LSU Doctoral Dissertations
The neurohypophysial hormone oxytocin is involved in the regulation of social behaviors, including social recognition, pair bonding, and sex-specific parental behaviors in a variety of species. Oxytocin triggers these social behaviors by binding to oxytocin receptors (OXTR) in various parts of the brain. Oxytocin-induced sex-typical behavior, therefore, suggests a sexual dimorphic distribution of OXTR in the brain. In recent years, the oxytocin system in the brain received tremendous attention as a potential pharmacological target for treatment of many psychiatric disorders, such as anxiety, autism spectrum disorders, and even sex-specific psychiatric disorder like postpartum depression (PPD). An important problem and a …
Stochastic Modeling Of Ovarian Follicle Growth In Adult Female Rats,
2020
Illinois State University
Stochastic Modeling Of Ovarian Follicle Growth In Adult Female Rats, Zhaozhi Li
Annual Symposium on Biomathematics and Ecology Education and Research
No abstract provided.
