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Full-Text Articles in Life Sciences
Review: Using Physiologically Based Models To Predict Population Responses To Phytochemicals By Wild Vertebrate Herbivores, J. S. Forbey, T. T. Caughlin
Review: Using Physiologically Based Models To Predict Population Responses To Phytochemicals By Wild Vertebrate Herbivores, J. S. Forbey, T. T. Caughlin
Biology Faculty Publications and Presentations
To understand how foraging decisions impact individual fitness of herbivores, nutritional ecologists must consider the complex in vivo dynamics of nutrient–nutrient interactions and nutrient–toxin interactions associated with foraging. Mathematical modeling has long been used to make foraging predictions (e.g. optimal foraging theory) but has largely been restricted to a single currency (e.g. energy) or using simple indices of nutrition (e.g. fecal nitrogen) without full consideration of physiologically based interactions among numerous co-ingested phytochemicals. Here, we describe a physiologically based model (PBM) that provides a mechanistic link between foraging decisions and demographic consequences. Including physiological mechanisms of absorption, digestion and metabolism …
Species-Specific Means And Within-Species Variance In Glucocorticoid Hormones And Speciation Rates In Birds, L. Z. Garamszegi, Jeremy W. Donald, C. D. Francis, M. J. Fuxjager, W. Goymann, M. Hau, Jerry F. Husak, Michele A. Johnson, Bonnie K. Kircher, R. Knapp, L. B. Martin, E. T. Miller, L. A. Schoenle, Maren N. Vitousek, T. D. Williams
Species-Specific Means And Within-Species Variance In Glucocorticoid Hormones And Speciation Rates In Birds, L. Z. Garamszegi, Jeremy W. Donald, C. D. Francis, M. J. Fuxjager, W. Goymann, M. Hau, Jerry F. Husak, Michele A. Johnson, Bonnie K. Kircher, R. Knapp, L. B. Martin, E. T. Miller, L. A. Schoenle, Maren N. Vitousek, T. D. Williams
Biology Faculty Research
At macroevolutionary scales, stress physiology may have consequences for species diversification and subspecies richness. Populations that exploit new resources or undergo range expansion should cope with new environmental challenges, which could favor higher mean stress responses. Within-species variation in the stress response may also play a role in mediating the speciation process: in species with broad variation, there will always be some individuals that can tolerate an unpredictable environment, whereas in species with narrow variation there will be fewer individuals that are able to thrive in a new ecological niche. We tested for the evolutionary relationship between stress response, speciation …
Standing Variation And The Capacity For Change: Are Endocrine Phenotypes More Variable That Other Traits?, M. C. Miles, Maren N. Vitousek, Jerry F. Husak, Michele A. Johnson, L. B. Martin, C. C. Taff, C. Zimmer, M. B. Lovern, M. J. Fuxjager
Standing Variation And The Capacity For Change: Are Endocrine Phenotypes More Variable That Other Traits?, M. C. Miles, Maren N. Vitousek, Jerry F. Husak, Michele A. Johnson, L. B. Martin, C. C. Taff, C. Zimmer, M. B. Lovern, M. J. Fuxjager
Biology Faculty Research
Circulating steroid hormone levels exhibit high variation both within and between individuals, leading some to hypothesize that these phenotypes are more variable than other morphological, physiological, and behavioral traits. This should have profound implications for the evolution of steroid signaling systems, but few studies have examined how endocrine variation compares to that of other traits or differs among populations. Here we provide such an analysis by first exploring how variation in three measures of corticosterone (CORT)—baseline, stress-induced, and post-dexamethasone injection—compares to variation in key traits characterizing morphology (wing length, mass), physiology (reactive oxygen metabolite concentration [d-ROMs] and antioxidant capacity), and …
Hormonebase, A Population-Level Database Of Steroid Hormone Levels Across Vertebrates, Maren N. Vitousek, Michele A. Johnson, Jeremy W. Donald, C. D. Francis, M. J. Fuxjager, W. Goymann, M. Hau, Jerry F. Husak, Bonnie K. Kircher, R. Knapp, L. B. Martin, E. T. Miller, L. A. Schoenle, J. J. Uehling, T. D. Williams
Hormonebase, A Population-Level Database Of Steroid Hormone Levels Across Vertebrates, Maren N. Vitousek, Michele A. Johnson, Jeremy W. Donald, C. D. Francis, M. J. Fuxjager, W. Goymann, M. Hau, Jerry F. Husak, Bonnie K. Kircher, R. Knapp, L. B. Martin, E. T. Miller, L. A. Schoenle, J. J. Uehling, T. D. Williams
Biology Faculty Research
Hormones are central regulators of organismal function and flexibility that mediate a diversity of phenotypic traits from early development through senescence. Yet despite these important roles, basic questions about how and why hormone systems vary within and across species remain unanswered. Here we describe HormoneBase, a database of circulating steroid hormone levels and their variation across vertebrates. This database aims to provide all available data on the mean, variation, and range of plasma glucocorticoids (both baseline and stress-induced) and androgens in free-living and un-manipulated adult vertebrates. HormoneBase (www.HormoneBase.org) currently includes >6,580 entries from 476 species, reported in 648 publications from …
Do Seasonal Glucocorticoid Changes Depend On Reproductive Investment? A Comparative Approach In Birds, S. Casagrande, L. Z. Garamszegi, W. Goymann, Jeremy W. Donald, C. D. Francis, M. J. Fuxjager, Jerry F. Husak, Michele A. Johnson, Bonnie K. Kircher, R. Knapp, L. B. Martin, E. T. Miller, L. A. Schoenle, Maren N. Vitousek, T. D. Williams, M. Hau
Do Seasonal Glucocorticoid Changes Depend On Reproductive Investment? A Comparative Approach In Birds, S. Casagrande, L. Z. Garamszegi, W. Goymann, Jeremy W. Donald, C. D. Francis, M. J. Fuxjager, Jerry F. Husak, Michele A. Johnson, Bonnie K. Kircher, R. Knapp, L. B. Martin, E. T. Miller, L. A. Schoenle, Maren N. Vitousek, T. D. Williams, M. Hau
Biology Faculty Research
Animals go through different life history stages such as reproduction, moult, or migration, of which some are more energy-demanding than others. Baseline concentrations of glucocorticoid hormones increase during moderate, predictable challenges and thus are expected to be higher when seasonal energy demands increase, such as during reproduction. By contrast, stress-induced glucocorticoids prioritize a survival mode that includes reproductive inhibition. Thus, many species down-regulate stress-induced glucocorticoid concentrations during the breeding season. Interspecific variation in glucocorticoid levels during reproduction has been successfully mapped onto reproductive investment, with species investing strongly in current reproduction (fast pace of life) showing higher baseline and lower …
Breaking Out From Tradition: Redesign Of Large Physiology Lecture Increases Engagement, Inclusion, And Student Outcomes, Jordyn Dickey, John Redden, Kristen Kimball
Breaking Out From Tradition: Redesign Of Large Physiology Lecture Increases Engagement, Inclusion, And Student Outcomes, Jordyn Dickey, John Redden, Kristen Kimball
Honors Scholar Theses
The human digestive system is a diverse network of cells, tissues, and organs that is regulated by intrinsic (e.g. nervous and endocrine systems) and extrinsic factors (e.g. secretions, pH, and the microbiome). Given the volume of content and the dense physiology involved, this system is difficult for instructors to teach and equally challenging for students to understand. This is especially true in our two-semester Human Anatomy and Physiology course for pre-health students at the University of Connecticut. In the Spring 2017 semester, we developed and implemented an active learning based approach when teaching the histology and regulation of gastric secretions …
The Mechanism Of Biotremor Production In The Veiled Chameleon (Chamaeleo Calyptratus), Samuel Tegge
The Mechanism Of Biotremor Production In The Veiled Chameleon (Chamaeleo Calyptratus), Samuel Tegge
Masters Theses & Specialist Projects
Vibratory communication has evolved in numerous animal groups, including insects, spiders, fishes, mammals, and was recently discovered in veiled chameleons (Chamaeleo calyptratus). I examined the mechanism by which C. calyptratus produce these biotremors. Muscle activity data were gathered during simulated anti-predator responses via electromyography (EMG) with simultaneous recordings of biotremor production using an accelerometer. I correlated EMG data with the accelerometer data to implicate the muscles responsible for the production of the biotremors. Mixed-effect linear regression models described the mechanism, and a model selection framework determined which model fit the data best. I then used an analysis of variance to …
Iucn Conservation Status Does Not Predict Glucocortoid Concentrations In Reptiles And Birds, L. B. Martin, Maren N. Vitousek, Jeremy W. Donald, T. Flock, M. J. Fuxjager, W. Goymann, M. Hau, Jerry F. Husak, Michele A. Johnson, Bonnie K. Kircher, R. Knapp, E. T. Miller, L. A. Schoenle, T. D. Williams, C. D. Francis
Iucn Conservation Status Does Not Predict Glucocortoid Concentrations In Reptiles And Birds, L. B. Martin, Maren N. Vitousek, Jeremy W. Donald, T. Flock, M. J. Fuxjager, W. Goymann, M. Hau, Jerry F. Husak, Michele A. Johnson, Bonnie K. Kircher, R. Knapp, E. T. Miller, L. A. Schoenle, T. D. Williams, C. D. Francis
Biology Faculty Research
Circulating glucocorticoids (GCs) are the most commonly used biomarkers of stress in wildlife. However, their utility as a tool for identifying and/or managing at-risk species has varied. Here, we took a very broad approach to conservation physiology, asking whether International Union for the Conservation of Nature (IUCN) listing status (concern versus no obvious concern) and/or location within a geographic range (edge versus non-edge) predicted baseline and post-restraint concentrations of corticosterone (CORT) among many species of birds and reptiles. Even though such an approach can be viewed as coarse, we asked in this analysis whether CORT concentrations might be useful to …
Detecting Bias In Large-Scale Comparative Analyses: Methods For Expanding The Scope Of Hypothesis-Testing With Hormonebase, Michele A. Johnson, C. D. Francis, E. T. Miller, C. J. Downs, Maren N. Vitousek
Detecting Bias In Large-Scale Comparative Analyses: Methods For Expanding The Scope Of Hypothesis-Testing With Hormonebase, Michele A. Johnson, C. D. Francis, E. T. Miller, C. J. Downs, Maren N. Vitousek
Biology Faculty Research
To address large-scale questions in evolutionary biology, the compilation of data from a variety of sources is often required. This is a major challenge in the development of databases in organismal biology. Here, we describe the procedure we used to reconstruct the phylogeny of the 474 species represented in HormoneBase, including fish, amphibians, mammals, birds, and reptiles. We also provide the methodology used to compile vertebrate environmental, life history, and metabolic rate data for use in conjunction with the HormoneBase database to test hypotheses of the evolution of steroid hormone traits. We then report a series of analyses using these …
The Effects Of Aqueous Nitrate On Freshwater Crayfish, Erik Hartman
The Effects Of Aqueous Nitrate On Freshwater Crayfish, Erik Hartman
Williams Honors College, Honors Research Projects
Globalization and a rising need for greater production from the agricultural system have increased the use of fertilizer by farms across the entire country. The purpose of this experiment was to observe the effects of aqueous nitrate (commonly found in many fertilizers) on the metabolic rate and hemolymph lactate concentration of freshwater crayfish. After exposure, there was no observed change in metabolic rate, but there was a significant decrease in hemolymph lactate concentration in the groups exposed to nitrate.
Cold Exposure Effects On Cardiac Function And Synaptic Transmission At The Neuromuscular Junction In Invertebrates, Yuechen Zhu, Robin L. Cooper
Cold Exposure Effects On Cardiac Function And Synaptic Transmission At The Neuromuscular Junction In Invertebrates, Yuechen Zhu, Robin L. Cooper
Biology Faculty Publications
This review emphasizes how ectothermic animals respond physiologically to environmental temperature changes and cold stress. Generally ectothermic animals cannot generate heat to maintain their body temperature but they can still survive in various temperature zones. Various organisms have been analyzed anatomically and physiologically in the attempt to understand the underlying mechanisms of this temperature adaptation. A few of the changes in the metabolic and molecular function of proteins are discussed. The potential of how hormonal modulation of cardiac and nervous systems which influences responses during exposure cold exposure is also addressed. The focus of this review is on the effect …
Forensic Markers Of Lampricide Toxicity In Oncorhynchsus Mykiss, Chris White
Forensic Markers Of Lampricide Toxicity In Oncorhynchsus Mykiss, Chris White
Theses and Dissertations (Comprehensive)
The lampricide 3-trifluoromethyl-4-nitrophenol (TFM) has been used for decades to control invasive sea lamprey (Petromyzon marinus) populations in the Great Lakes, normally with little harm to other fish populations. However, due to the nature of lampricide treatments and the chemical properties of TFM, adverse effects to non-target fishes and non-target mortality occasionally occur. However, investigations of non-target mortality can be complex, particularly if fish deaths are not noticed immediately, due to decomposition of the carcasses. The objectives of this thesis were to expose rainbow trout (Oncorhynchsus mykiss) to TFM in order to: (i) identify forensic markers …
The Influence Of Physiological And Abiotic Factors On The Sensitivity Of The Sea Lamprey (Petromyzon Marinus) To The Lampricide 3-Trifluoromethyl-4-Nitrophenol (Tfm), Alexandra Muhametsafina
The Influence Of Physiological And Abiotic Factors On The Sensitivity Of The Sea Lamprey (Petromyzon Marinus) To The Lampricide 3-Trifluoromethyl-4-Nitrophenol (Tfm), Alexandra Muhametsafina
Theses and Dissertations (Comprehensive)
Invasive sea lamprey (Petromyzon marinus) in the Great Lakes are controlled using the pesticide (lampricide) 3-trifluoromethyl-4-nitrophenol (TFM), which is applied to nursery streams containing larval lamprey. The toxicity of TFM to lamprey is affected by various environmental and physiological factors, which can lead to residual lamprey that survive TFM treatment. The goal of this study was to investigate how abiotic (season and temperature) factors interacted with physiological parameters (whole body and tissue energy reserves) to influence TFM sensitivity in sea lamprey. Toxicity tests were conducted at different times of the year (spring, early and late summer, fall) and …
Fast Voltage-Gated Sodium Channel Currents And Action Potential Firing In R6/2 Skeletal Muscle, Eric Joshua Reed
Fast Voltage-Gated Sodium Channel Currents And Action Potential Firing In R6/2 Skeletal Muscle, Eric Joshua Reed
Browse all Theses and Dissertations
Huntington’s disease (HD) is a degenerative disorder caused by expanded CAG repeats in the Huntingtin gene, which results in cognitive problems as well as muscle weakness, chorea, rigidity, and dystonia. Most research in HD has focused on neurodegeneration, but recent studies have found peripheral defects that may help explain the debilitating motor symptoms of HD. We have shown that skeletal muscle from the R6/2 transgenic mouse model of HD is hyperexcitable due to decreases in resting chloride and potassium currents. Other groups have speculated that the fast voltage-gated sodium channels may be affected in Huntington’s disease as well. To fully …
Osmotic Activation Of Sperm Motility Via Water Flow Through Aquaporins In The Freeze-Tolerant Cope's Gray Treefrog, Dryophytes Chrysoscelis, Deja Miller
Browse all Theses and Dissertations
Gametes of gray treefrogs, Dryophytes chrysoscelis, are deposited into freshwater ponds. Sperm undergo spermatogenesis and maturation beginning in the seminiferous tubules and migrating to the lumen. In mammals and fishes, these cells are immotile within the isosmotic fluid of the testes and have motility activated by exposure to a hyper- or hypoosmotic medium. Water flows into or out of the sperm cell, altering intracellular ionic concentrations, and ultimately stimulates flagellar movement. We tested the hypothesis that exposure to a hypotonic environment activates motility of gray treefrog sperm. We also hypothesized that osmotic water uptake is facilitated by expression of water …