Physiology Commons^™

Using Biometrics, Behavioral Observations, And Multiple Molecular Techniques To Assess The Impacts Of Changes In Temperature And Salinity On The Common Bay Mussel (Mytilus Trossulus), Casey Martin

Dissertations and Theses

The intertidal zone is a place of rapid and frequent change that is home to a variety of creatures who are essential to the integrity of the habitat. Mussels are robust sessile bivalves that anchor to the rocks of the intertidal. The prominent species on the Oregon Coast, the Common Bay Mussel (Mytilus trossulus), plays an essential role as a coastal food source, water column filter, and barrier to prevent erosion due to wave action. Mytilus trossulus withstands daily shifts in temperature, salinity, and tide, as well as seasonal changes. Global climate change due to excess carbon emissions …

Resistance Training And Running Performance And Economy: A Literature Review, James Bottrill

University Honors Theses

Running performance is largely determined by maximal oxygen uptake (VO₂ max), velocity at VO₂ max, fractional utilisation of VO₂ max and running economy. Running economy is relatively under-researched and could be improved by resistance training because of its neuromuscular underpinnings. However, existing research on this topic is quite unorganised and inconclusive and is yet to prove a direct linkage between resistance training, running economy and performance. This literature review aimed to provide an organised overview of the existing literature, identify and address confounding variables and provide recommendations for future research. A search for studies was conducted via …

A Multi-Species Study On Several Types Of Visitor Effects On The Behavior And Physiology Of Animals At The Oregon Zoo, Laurel Berylline Fink

Dissertations and Theses

The visitor effect on zoo animals is one of the expanding research topics in zoo animal research. As visitors are a mandatory feature of zoological institutions, understanding their effects on zoo animals is imperative for maximizing zoo animal welfare. Zoo animals are subject to many anthropogenic influences: visual, olfactory, and audible, for example. This dissertation investigates several of the effects of visitor presence and its relative influence on six mammalian species: cheetahs (Acinonyx jubatus), African painted dogs (Lycaon pictus), Asian elephants (Elephas maximus indicus & Elephas maximus borneensis), giraffes (Giraffa camelopardalis reticulata & …

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 …

Control Of Blood Volume Following Hypovolemic Challenge In Vertebrates: Transcapillary Versus Lymphatic Mechanisms., Stanley S. Hillman, Robert C. Drewes, Michael S. Hedrick

Biology Faculty Publications and Presentations

Anurans have an exceptional capacity for maintaining vascular volume compared with other groups of vertebrates. They can mobilize interstitial fluids via lymphatic return at rates that are ten-fold higher than mammals. This extraordinary capacity is the result of coordination of specialized skeletal muscles and pulmonary ventilation that vary volume and pressure of subcutaneous lymph sacs, thus moving lymph to dorsally located lymph hearts that return lymph to the vascular space. Variation in the capacity to mobilize lymph within anurans varies with the degree of terrestriality, development of skeletal muscles, lung volume and lung compliance, and lymph heart pressure development. This …

Assessing Well-Being Of Asian Elephants (Elephas Maximus) Through Major Events And Transitions, With Development And Aging, And Husbandry Changes, Sharon Stuart Glaeser

Dissertations and Theses

In this body of research, reproductive and adrenal hormones and behavior were used to evaluate individual and group responses to physiological, social, and environmental changes in zoo-housed Asian elephants, considering factors of sex, age, and life stage. Animals experience physiological, social, and environmental changes as part of their natural history and individual life experience. Measures of both positive and negative states are needed to assess the impact of these changes at the individual and group level. Such measures can help us better understand how animals cope with a changing environment, and can help inform management decisions. Through longitudinal analyses of …

Energy Stores And Life-History Transitions In Red-Sided Garter Snakes (Thamnophis Sirtalis Parietalis), Rachel Catharine Wilson

Dissertations and Theses

All organisms must prioritize investment in either reproductive or self-maintenance activities. Despite this established paradigm, our understanding of how organisms choose to prioritize certain behaviors and physiologies over others remains limited. It is likely that an organism's energy status not only influences variation in reproductive effort, but also transitions to and from reproductive activities. My dissertation aims to investigate how energy metrics (body condition index, adipocyte follicle size, and liver glycogen) relate to reproduction and associated life-history stages in red-sided garter snakes (Thamnophis sirtalis parietalis). Chapter two examines if energy metrics differ with migratory status and sex in …

Hydrophobic Surfactant Proteins Strongly Induce Negative Curvature, Mariya Chavarha, Ryan W. Loney, Shankar B. Rananavare, Stephen B. Hall

Chemistry Faculty Publications and Presentations

The hydrophobic surfactant proteins SP-B and SP-C greatly accelerate the adsorption of vesicles containing the surfactant lipids to form a film that lowers the surface tension of the air/water interface in the lungs. Pulmonary surfactant enters the interface by a process analogous to the fusion of two vesicles. As with fusion, several factors affect adsorption according to how they alter the curvature of lipid leaflets, suggesting that adsorption proceeds via a rate-limiting structure with negative curvature, in which the hydrophilic face of the phospholipid leaflets is concave. In the studies reported here, we tested whether the surfactant proteins might promote …

Health And Well-Being Of Young Adults With Cerebral Palsy, Susan Elizabeth Sienko

Dissertations and Theses

Health is a multidimensional, holistic, concept integrating physical and mental health. In childhood, the most common cause of physical disability is Cerebral Palsy (CP). For individuals with CP, health and well-being is impacted by the complex interactions among their physical impairments, activity, participation and environmental barriers. Although CP is considered non-progressive, secondary conditions (pain and fatigue) and their functional consequences have been found to worsen as the individual with CP ages. While preliminary evidence shows that many of the physical impairments (pain, fatigue, depression) reported in adults with CP begin during late adolescence, there is little information about the role …

The Effects Of Hypoxia And Temperature On Developing Embryos Of The Annual Killifish Austrofundulus Limnaeus, Skye N. Anderson

Dissertations and Theses

Little is known about the physiology or biochemistry of hypoxia (reduced levels of oxygen) tolerance during development in vertebrate embryos. In most species, relatively brief bouts of severe hypoxia are lethal or teratogenic. An exception to such hypoxia intolerance is the annual killifish Austrofundulus limnaeus, in which populations persist in hypoxic environments. This species inhabits seasonal ponds in Venezuela, surviving through the dry season in the form of diapausing embryos. Embedded in the pond sediment, embryos of A. limnaeus are routinely exposed to hypoxia and anoxia (lack of oxygen) as part of their normal development. Here, we exposed embryos to …

Metabolic Support Of Anaerobiosis In Embryos Of The Annual Killifish Austrofundulus Limnaeus, Andrew Mccracken

Dissertations and Theses

Embryos of the annual killifish Austrofundulus limnaeus display a remarkable tolerance to anoxia during development, most notably during embryonic diapause. Little is known about the metabolic or enzymatic changes that accompany this state of anoxia tolerance. This study examined the metabolic changes associated with exposure to anoxia by measuring the activity of the enzyme phosphoenolpyruvate carboxykinase (PEPCK), and by profiling the concentration of 31 metabolites ranging from amino acids to citric cycle intermediates at 4 different developmental stages, diapause 2 (DII), 4 days post diapause (dpd), 12 and 22 dpd. Embryos of A. limnaeus showed stage specific changes in concentrations …

Cell Cycle Arrest Associated With Anoxia-Induced Quiescence, Anoxic Preconditioning, And Embryonic Diapause In Embryos Of The Annual Killifish Austrofundulus Limnaeus, Camie Lynn Meller, Robert Meller, Roger P. Simon, Kristin M. Culpepper, Jason E. Podrabsky

Biology Faculty Publications and Presentations

Embryos of the annual killifish Austrofundulus limnaeus can enter into dormancy associated with diapause and anoxia-induced quiescence. Dormant embryos are composed primarily of cells arrested in the G1/G0 phase of the cell cycle based on flow cytometry analysis of DNA content. In fact, most cells in developing embryos contain only a diploid complement of DNA, with very few cells found in the S, G2, or M phases of the cell cycle. Diapause II embryos appear to be in a G0-like state with low levels of cyclin D1 and p53. However, the active form of pAKT is high during diapause II. …

Mitochondrial Physiology Of Diapausing And Developing Embryos Of The Annual Killifish Austrofundulus Limnaeus: Implications For Extreme Anoxia Tolerance, Jeffrey M. Duerr, Jason E. Podrabsky

Biology Faculty Publications and Presentations

Diapausing embryos of the annual killifish Austrofundulus limnaeus have the highest reported anoxia tolerance of any vertebrate and previous studies indicate modified mitochondrial physiology likely supports anoxic metabolism. Functional mitochondria isolated from diapausing and developing embryos of the annual killifish exhibited VO2, respiratory control ratios (RCR), and P:O ratios consistent with those obtained from other ectothermic vertebrate species. Reduced oxygen consumption associated with dormancy in whole animal respiration rates are correlated with maximal respiration rates of mitochondria isolated from diapausing versus developing embryos. P:O ratios for developing embryos were similar to those obtained from adult liver, but were diminished in …

Whole Body I=In Vivo Vascular Compliance In Two Amphibians, Bufo Marinus And Rana Cate, Todd Micheal Hoagland

Dissertations and Theses

The mean circulatory filling pressure (MCFP), vascular compliance (C) and unstressed volume (USV) were measured in Bufo marinus and Rana catesbeiana, using an in vivo preparation. Capacitance curves were constructed by varying total vascular volume and then measuring MCFP. These capacitance curves enable the extrapolation of USV and the measurement of vascular compliance. The MCFP, C, and USV were 8.6 ± 0.2 (mmHg), 3.7 (ml· mmHg-1 · kg- 1 ) and 2.5 (ml), respectively, in B. marinus. The MCFP, C, and USV were 9.5 ± 0.1 (mmHg), 2.2 (ml· mmHg-1 · kg- 1 ) and 14.2 (ml), respectively, …

Brainstem Auditory Evoked Potentials In Anuran Amphibians, Marc Brandon Carey

Dissertations and Theses

In this study, I looked at the effects of sound level, temperature and dehydration/hypernatremia on the brainstem auditory evoked potential (BAEP) of four species of anuran amphibians (Rana pipiens, Rana catesbeiana, Bufo americanus and Bufo terrestris). The BAEP was used because it allowed me to monitor both the peripheral and central aspects of auditory nervous function simultaneously and over a long period of time.

A Comparison Of Circadian Rhythms In Day And Night Shift Workers, Mary Lee Blood

Dissertations and Theses

The present study examined whether and to what extent physiological rhythms of long-term night workers become adapted to their unconventionally scheduled hours of work and sleep and how the degree of adaptation would be reflected in ratings of sleep quality, mood, anxiety, energy and satisfaction.

Determinants Of 2000 Meter Rowing Ergometer Performance, Jeff C. Young

Dissertations and Theses

Lean body weight and aerobic and anaerobic factors have long been recognized as important determinants of performance in the 2000 meter (M) race distance for rowing. Current research with noninvasive techniques has important implications for training and performance but is inconclusive. The purpose of this study was to investigate the relationship between a 2000 M rowing ergometer performance test (PT) and lean body weight (LBW), velocity at heart rate deflection (Vd), and anaerobic capacity (AC) in experienced rowers. Vd was used as an estimate of aerobic function. Thirteen trained male rowers (mean age 38.5 ± 8 years) were studied. Hydrostatic …

Hourly Fluctuation Of Middle Ear Pressure As A Function Of Age In School-Age Children, Susan Hogue Henry

Dissertations and Theses

Tympanometry is a useful means of evaluating the status of the middle ear. For the pediatric population, tympanometry is particularly valuable for determining the presence of middle ear effusion. The test has been incorporated in many school hearing conservation programs because of its ease of administration, objectivity, and diagnostic value.

In a study by deJonge and Cummings (1985), the hourly fluctuation of middle ear pressure was reported in a group of kindergarten-age children. The variability of middle ear pressure for that group of children averaged 150 daPa. In the present study, a maturational effect of this hourly fluctuation was observed …

Nitrogen And Iron Interactions In Filamentous Cyanobacteria, David Allen Hutchins

Dissertations and Theses

The investigations described in this paper are an attempt to further define and quantify the interrelationship of nitrogen fixation and iron nutritional physiology in these two species. Chapter II will present and compare data on nutritional ratios of field collected Trichodesmium colonies and laboratory Anabaena cultures, with the intent of examining possible correlations between observed iron levels and protein nitrogen and chlorophyll concentrations, as well as nitrogen fixation rates. Chapter Ill is an examination of nitrogen fixation and siderophore production in Anabaena with emphasis on the possible implications of hypothesized synergistic effects of these two physiological capabilities on cyanobacterial dominance …

The Physiology And Biochemistry Of Isolated Skeletal Muscle Mitochondria : A Comparative Study, Mark Lowell Wagner

Dissertations and Theses

The physiological limit to maximum aerobic capacity (VO₂max) in vertebrates has been attributed to cardiovascular oxygen delivery, to the ability of the muscle cells to consume oxygen, or to a fine-tuned development of all components of the respiratory system such that no single component can be shown to limit VO₂max. The above hypotheses have each been developed using different experiments with different animals. The comparative studies uniting these animals and methods are limited. In order to further our knowledge of the cellular limit to VO₂max, skeletal muscle mitochondria were isolated from species representing four …

Effects Of Graded And Steady Exercise And Self-Confidence On Stress, Kristine M. Clarke

Dissertations and Theses

This study examined the effects of steady, graded, and no exercise on stress reduction, and the effects of self-confidence on stress reduction through exercise. Seventy-two male and female volunteers from the Portland area, ranging in age from 19-49 years, served as subjects. Subjects completed pre and post measures of the Tennessee Self-Concept Scale and the state portion of the Spielberger State-Trait Anxiety Inventory. Subjects were divided into two experimental and one control group matched according to age and exercise history. The control group kept its exercise at a minimum for eight weeks. Exercise programs for the two experimental groups consisted …

The Effect Of Cold Acclimation On The Temperature Preference Of The Goldfish, Carassius Auratus, And The Brown Bullhead, Ictalurus Nebulosus, Alfred Lord

Dissertations and Theses

Two species of fish, Carassius auratus and Ictalurus nebulosus, were subjected to cold acclimation regimes. Acclimation temperatures were slowly lowered to 3°C, then held for a period of time. At various times during this regime, fish were taken out and allowed to spend time in a temperature gradient to determine their preferred temperatures. Carassius were left in the gradient just long enough to determine a measure of the acute temperature preference, while Ictalurus were left in the temperature gradient for longer periods of time to observe any changes that might occur as the fish adjusted to selected temperatures. In …

Decrease In Selected Temperature After Intracranial Dopamine Injections In Goldfish, Hercules Theodore Panayiotides-Djaferis

Dissertations and Theses

Goldfish (Carassius auratus) (40-80g) were injected with dopamine into the forebrain to study the possible involvement of this amine in central temperature regulation in these fish. Dopamine caused a decrease in selected temperature after injection into the rostral nucleus preopticus periventricularis (NPP). This effect was dependent on the dose of dopamine administered. Doses of 25, 50, 100 and 250 ng were used, injected in a volume of 0.2μ1. Injections in regions adjacent to the NPP elicited hypothermic effects only at the higher dosages. These effects were not consistent. Injections in caudal regions of the NPP elicited no effect. …

The Effect Of Body Temperature On Arteriovenous Oxygen Difference During Rest And Activity In The Toad, Bufo Marinus, Wayne Bryant Palioca

Dissertations and Theses

The relative contribution of arteriovenous oxygen (A-V O₂) difference to thermally-induced and activity-induced changes in metabolic rate (VO₂) were delineated in the toad, B. marinus. In conjunction, the influence of rest and activity, temperature, and removal of the pericardial sac on separation efficiency (Es) in the anuran ventricle was determined by direct measurement of arterial and venous percent oxygen saturation (% saturation), using a microsampling technique.

Norepinephrine And Temperature Regulation In Goldfish, Lonnie Paul Wollmuth

Dissertations and Theses

Cannulae were implanted into forebrain loci of goldfish (Carassius auratus; 45-90 g) to determine (i) the effects and site of action of intracranial norepinephrine (NE) injections on behavioral thermoregulation and (ii) the mechanism and the types of adrenoreceptors involved in the thermoregulatory effect of NE. After 30 min in a thermal gradient, implanted fish were injected with norepinephrinebitartrate salt (2.5-500 ng NE) in a total volume of 0.2 ul (carrier was 0.7% NaCl). Injections of 5, 10, 25, and 50 ng NE into the anterior aspect of the nucleus preopticus periventricularis (NPP1 Peter and Gill 1975) led to consistent, dose-dependent …