Open Access. Powered by Scholars. Published by Universities.®

Physiology Commons™

Open Access. Powered by Scholars. Published by Universities.®

Physiology

Discipline
Institution
Publication Year
Publication
Publication Type
File Type

Articles 91 - 120 of 141

Full-Text Articles in Physiology

Time-Activity And Energy Budgets Of Eared Grebes (Podiceps Nigricollis) At Salton Sea, Samantha San Francisco May 2017

Time-Activity And Energy Budgets Of Eared Grebes (Podiceps Nigricollis) At Salton Sea, Samantha San Francisco

Theses

Time-activity budgets have been a widely accepted way of approximating the daily energy expenditure of many species, including waterbirds. For this study, focal animal sampling was used to study Eared Grebes (Podiceps nigricollis) at their post-wintering stopover site, Salton Sea. Daylight time-activity budgets were converted to energy budgets using energy equivalents for diving, preening, swimming, and resting on water developed for Eared Grebes previously by H. I. Ellis (1994). Post-wintering Eared Grebes arrive at Salton Sea in waves at differing times in the spring. As a result, there can be individuals in a variety of physiological states during …


Boosting Of Hiv Envelope Cd4 Binding Site Antibodies With Long Variable Heavy Third Complementarity Determining Region In The Randomized Double Blind Rv305 Hiv-1 Vaccine Trial, David Easterhoff, M. Anthony Moody, Daniela Fera, Hao Cheng, Margaret Ackerman Feb 2017

Boosting Of Hiv Envelope Cd4 Binding Site Antibodies With Long Variable Heavy Third Complementarity Determining Region In The Randomized Double Blind Rv305 Hiv-1 Vaccine Trial, David Easterhoff, M. Anthony Moody, Daniela Fera, Hao Cheng, Margaret Ackerman

Dartmouth Scholarship

The canary pox vector and gp120 vaccine (ALVAC-HIV and AIDSVAX B/E gp120) in the RV144 HIV-1 vaccine trial conferred an estimated 31% vaccine efficacy. Although the vaccine Env AE.A244 gp120 is antigenic for the unmutated common ancestor of V1V2 broadly neutralizing antibody (bnAbs), no plasma bnAb activity was induced. The RV305 (NCT01435135) HIV-1 clinical trial was a placebo-controlled randomized double-blinded study that assessed the safety and efficacy of vaccine boosting on B cell repertoires. HIV-1- uninfected RV144 vaccine recipients were reimmunized 6–8 years later with AIDSVAX B/E gp120 alone, ALVAC-HIV alone, or a combination of ALVAC-HIV and AIDSVAX B/E gp120 …


Is Mitochondrial Development Impaired In Hyperoxic Rats And Does This Underpin The Blunting Of The Acute Hypoxic Ventilatory Response?, Tariq Hasan Fayyad Jan 2017

Is Mitochondrial Development Impaired In Hyperoxic Rats And Does This Underpin The Blunting Of The Acute Hypoxic Ventilatory Response?, Tariq Hasan Fayyad

Browse all Theses and Dissertations

Carotid body (CB) responses to hypoxia are low at birth and increase over time to mature responses. Using an in vitro rat CB-carotid sinus nerve (CSN) preparation, Kholwadwala and Donnelly (1992) demonstrated that the CSN activity in response to hypoxia increased from low levels to robust adult responses after two weeks. This time course of maturation was paralleled by an increase in TASK channel sensitivity to hypoxia in the O2-sensing Type I cells (Kim et al, 2011). Previous studies have indicated that a fall in Type I cell mitochondrial volume and an increase in the rate of oxidative phosphorylation may …


Examining The Combined Effects Of Dissolved Oxygen, Temperature, And Body Size On The Physiological Responses Of A Model Macrobenthic Polychaete Species, Capitella Teleta, Kelsey Burns Gillam Dec 2016

Examining The Combined Effects Of Dissolved Oxygen, Temperature, And Body Size On The Physiological Responses Of A Model Macrobenthic Polychaete Species, Capitella Teleta, Kelsey Burns Gillam

Dissertations

While the scientific community is in consensus that coastal systems are threatened by climate change, few climate change studies test the effects of more than one variable directly related to climate change. The dissolved oxygen (DO) levels of the ocean are currently subject to both global warming and eutrophication; 94% of all hypoxia zones are expected to experience >2°C increase by 2035. This dissertation aims to examine how a model organism responds to simultaneous thermal and DO stress involving four levels of DO (100%, 70%, 50%, and 20%) saturation and three temperatures (15°C, 20°C, and 25°C).

The polychaete, Capitella teleta …


Human Anatomy & Physiology Society ( Haps ) Southern Regional Meeting 2016, Cheryl Purvis Oct 2016

Human Anatomy & Physiology Society ( Haps ) Southern Regional Meeting 2016, Cheryl Purvis

Faculty Proceedings, Presentations, Speeches and Lectures

No abstract provided.


The Effect Of Metronome Use On Heart Rates And Rpe For Drum Corps Percussionists, Danielle Dye, Vaughn Barry Oct 2016

The Effect Of Metronome Use On Heart Rates And Rpe For Drum Corps Percussionists, Danielle Dye, Vaughn Barry

International Journal of Exercise Science

International Journal of Exercise Science 9(4): 412-418, 2016. The purpose was to evaluate if playing a musical selection without a metronome would affect the heart rates and rate of perceived exertion for drum corps percussionists. Heart rate and RPE values were collected from 11 battery and 12 front ensemble members from one drum corps. The music consisted of two portions of the show at different tempos of 96 and 176 beats per minute. The music was performed at "standstill" with the battery members lined up behind the front ensemble marching, but not moving around or carrying their instruments. The participants …


Escape Strategy Of The Cockroach (Gromphadorhina Portentosa) To Heat And Looming Stimuli, Jiangda Ou May 2016

Escape Strategy Of The Cockroach (Gromphadorhina Portentosa) To Heat And Looming Stimuli, Jiangda Ou

Senior Honors Projects, 2010-2019

Escape responses to aversive stimuli have been observed in insects, including species of cricket, fly, locust, and cockroach. The goal of this study was to investigate the escape strategy of the Madagascar cockroach, Gromphadorhina portentosa. In regard to this species, Erickson and colleagues (2015) showed that electrical stimulation of both cerci and antennae together could generate an escape response. However, in other reports (Olsen and Triblehorn, 2014), it was observed that wind could not elicit the escape response. In this study, G. portentosa was stimulated by looming and heat stimuli. A 2.5’’ black ball approaching at 1 m/s was used …


Bleeding Keaney Blue: An Analysis Of Sports Fandom And The Supporters Of Uri Basketball, Lia M. Moceri May 2016

Bleeding Keaney Blue: An Analysis Of Sports Fandom And The Supporters Of Uri Basketball, Lia M. Moceri

Senior Honors Projects

In the United States, sports are so prevalent on the national, state, and local level that researchers assert they have become a major component of everyday life. In fact, millions of Americans consider themselves sports fans. Studying sports fandom offers an interesting insight into the human condition.

This paper begins by looking at sports fans on a psychological level by examining socialization, the process of becoming a sports fan. It also examines the reasons people become fans and the degree to which people identify as a fan. An important psychological aspect when studying sports fans is identity and how a …


Development Of Vip-Sst Interneuron Associations In Mouse Neocortex And Entorhinal Cortex, Aayushi A. Mehta May 2016

Development Of Vip-Sst Interneuron Associations In Mouse Neocortex And Entorhinal Cortex, Aayushi A. Mehta

Honors Scholar Theses

Cortical networks depend upon inhibition through the neurotransmitter GABA to control and coordinate specific spatiotemporal circuit patterns, underlying the exquisite complexity of neural signaling. Disinhibition, a form of inhibition where inhibitory neurons inhibit other inhibitory cells, further aids in amplifying local neural processing in a selective, organized manner. A subset of GABAergic interneurons, vasoactive intestinal peptide-expressing (VIP) cells, preferentially inhibit somatostatin interneurons, which provide inhibitory input onto pyramidal cells, thus creating an archetypal circuit illustrating disinhibition in the cortex. The aim of this anatomical study was to investigate variations in GABAergic VIP synapses onto somatostatin-expressing inhibitory interneurons in mice at …


The Influence Of Canine Aggression And Behavioral Treatment On Heart Rate Variability, Lydia Craig Apr 2016

The Influence Of Canine Aggression And Behavioral Treatment On Heart Rate Variability, Lydia Craig

Psychology Honors Projects

Dog aggression affects many, with nearly 5 million dog bites reported yearly in the United States alone. With the physical, emotional, and monetary costs of bites, it is of considerable interest to identify dogs that are likely to bite. One physiological measure that might serve as an index of aggression is heart rate variability (HRV), which refers to vagally mediated beat-to-beat change in heart rate. Low HRV has been associated with impaired emotional and behavioral regulation and stress in both humans and animals. To assess whether this measure corresponds with aggression in dogs, resting HRV was measured for dogs with …


Factors Affecting The Immune System Of The Ornate Box Turtle (Errapene Ornata), Michelle W. Mcquinn, Abigail A. Neyer, Gwendolyn C. Bachman Apr 2016

Factors Affecting The Immune System Of The Ornate Box Turtle (Errapene Ornata), Michelle W. Mcquinn, Abigail A. Neyer, Gwendolyn C. Bachman

UCARE: Research Products

While many studies have detailed the complex intricacies of the endothermic immune system, relatively little is known about the immune system of ectotherms--specifically, reptiles. In an attempt to gain more knowledge about the factors affecting reptilian immune function, ornate box turtles (Terrapene ornata) were subjected to chronic stress in the form of high ambient temperatures in a semi-natural environment. It was hypothesized that chronic stress would lead to elevated levels of corticosterone in the blood, which would, in turn, suppress immune activity. It was found that body temperature and body mass in particular were significantly affected by chronic heat stress. …


The Glucose Model Of Mediation: Physiological Bases Of Willpower As Important Explanations For Common Mediation Behavior, Roy F. Baumeister, W. Scott Simpson, Stephen J. Ware, Daniel S. Weber Feb 2016

The Glucose Model Of Mediation: Physiological Bases Of Willpower As Important Explanations For Common Mediation Behavior, Roy F. Baumeister, W. Scott Simpson, Stephen J. Ware, Daniel S. Weber

Pepperdine Dispute Resolution Law Journal

Success in life requires the ability to resist urges and control behavior. This ability is commonly called “willpower,” the capacity to overcome impulses and engage in conscious acts of self-control. Social psychologists believe willpower is a finite resource dependent on physiological bases including glucose (from food and drink), sleep and other forms of rest, and the absence of stress. In short, people who are hungry, exhausted, or highly stressed tend to have less willpower than those who are well-fed, well-rested, and relatively stress-free. In addition, a person who exerts self-control (uses willpower) tends to reduce temporarily the amount of willpower …


Toddlers’ Word Learning From Contingent And Non-Contingent Video On Touchscreens, Heather L. Kirkorian, Koeun Choi, Tiffany A. Pempek Jan 2016

Toddlers’ Word Learning From Contingent And Non-Contingent Video On Touchscreens, Heather L. Kirkorian, Koeun Choi, Tiffany A. Pempek

Psychology Faculty Scholarship

Researchers examined whether contingent experience using a touchscreen increased toddlers’ ability to learn a word from video. One-hundred-sixteen children (24-36 mos) watched an on-screen actress label an object: (1) without interacting, (2) with instructions to touch anywhere on the screen, or (3) with instructions to touch a specific spot (location of labeled object). The youngest children learned from contingent video in the absence of reciprocal interactions with a live social partner, but only when contingent video required specific responses that emphasized important information on the screen. Conversely, this condition appeared to disrupt learning by slightly older children who were otherwise …


Effects Of Supplemental Hydration On Physiology And Behavior Of Northern Pacific Rattlesnakes (Crotalus Oreganus Oreganus), Griffin D. Capehart Oct 2015

Effects Of Supplemental Hydration On Physiology And Behavior Of Northern Pacific Rattlesnakes (Crotalus Oreganus Oreganus), Griffin D. Capehart

Master's Theses

Hydration is a critical element for many physiological processes in vertebrates, such as protein production, innate immunity, and behavioral processes such as daily activity and thermoregulation. Few studies have directly assessed the effect of hydration on these animals in nature. While it seems intuitive that drought is stressful to animals, studies examining drought are typically observational and fail to assess how the hydration state of these animals influences their physiology and behavior. We tested for an effect of hydration on several physiological and behavioral parameters in Northern Pacific rattlesnakes (Crotalus oreganus oreganus) by experimentally manipulating hydration levels in …


Assessing Computer Vision Syndrome Risk For Pilots, Curt Mowry, David C. Ison Jan 2015

Assessing Computer Vision Syndrome Risk For Pilots, Curt Mowry, David C. Ison

Journal of Aviation/Aerospace Education & Research

The purpose of this study was to determine if pilots are at risk for computer vision syndrome (CVS) as computer display technology becomes commonplace in modern cockpits and simulators. A review of computer vision syndrome respect to causes and effects is provided. Display technology used in aircraft and simulators are outlined. Ergonomics and human factors for pilots in aircraft and in simulators are discussed in relation to video displays. A survey of 178 individuals was conducted to determine if there is a statistically significant link between exposure to computer displays and three categories of symptoms of CVS on the flight …


Human Anatomy And Physiology Preparatory Course (1st Edition), Carlos Liachovitzky Jan 2015

Human Anatomy And Physiology Preparatory Course (1st Edition), Carlos Liachovitzky

Open Educational Resources

The overall purpose of this preparatory course textbook is to help students familiarize with some terms and some basic concepts they will find later in the Human Anatomy and Physiology I course.

The organization and functioning of the human organism generally is discussed in terms of different levels of increasing complexity, from the smallest building blocks to the entire body. This Anatomy and Physiology preparatory course covers the foundations on the chemical level, and a basic introduction to cellular level, organ level, and organ system levels. There is also an introduction to homeostasis at the beginning.


Understanding The Physiological Effects Of Suspended Material On Rainbow Trout (Oncorhynchus Mykiss), Tyler J. Weinhardt Jan 2015

Understanding The Physiological Effects Of Suspended Material On Rainbow Trout (Oncorhynchus Mykiss), Tyler J. Weinhardt

Theses and Dissertations (Comprehensive)

The effect of global warming on northern environments is becoming increasingly evident. Melting of underlying permafrost is associated with widespread impacts in these environments. The loss of permafrost results in a destabilizing of underlying sedimentary layers resulting in thermokarst slumping. When this occurs on a large scale (mega-slumping) soil material becomes mobilized and is carried into local streams and rivers. The purpose of this study is to examine the sub-lethal physiological effects that suspended material has on rainbow trout (Oncorhynchus mykiss) in the context of the Peel River Plateau. Juvenile rainbow trout were exposed (following Environment Canada exposure …


Color Updating On The Apparent Motion Path, Edmund Chong, Sang Wook Hong, Won Mok Shim Dec 2014

Color Updating On The Apparent Motion Path, Edmund Chong, Sang Wook Hong, Won Mok Shim

Dartmouth Scholarship

When a static stimulus appears successively at two distant locations, we perceive illusory motion of the stimulus across them–long-range apparent motion (AM). Previous studies have shown that when the apparent motion stimuli differ in shape, interpolation between the two shapes is perceived across the AM path. In contrast, the perceived color during AM has been shown to abruptly change from the color of the first stimulus into that of the second, suggesting interpolation does not occur for color during AM. Here, we report the first evidence to our knowledge, that an interpolated color, distinct from the colors of either apparent …


Natural Selection On Thermal Performance In A Novel Thermal Environment, Michael L. Logan, Robert M. Cox, Ryan Calsbeek Sep 2014

Natural Selection On Thermal Performance In A Novel Thermal Environment, Michael L. Logan, Robert M. Cox, Ryan Calsbeek

Dartmouth Scholarship

Tropical ectotherms are thought to be especially vulnerable to climate change because they are adapted to relatively stable temperature regimes, such that even small increases in environmental temperature may lead to large decreases in physiological performance. One way in which tropical organisms may mitigate the detrimental effects of warming is through evolutionary change in thermal physiology. The speed and magnitude of this response depend, in part, on the strength of climate-driven selection. However, many ectotherms use behavioral adjustments to maintain preferred body temperatures in the face of environmental variation. These behaviors may shelter individuals from natural selection, preventing evolutionary adaptation …


Primate Energy Eexpenditure And Life History, Herman Pontzer, David A. Raichlen, Adam D. Gordon, Kara K. Schroepfer-Walker, Brian Hare, Matthew C. O’Neill, Kathleen M. Muldoon Jan 2014

Primate Energy Eexpenditure And Life History, Herman Pontzer, David A. Raichlen, Adam D. Gordon, Kara K. Schroepfer-Walker, Brian Hare, Matthew C. O’Neill, Kathleen M. Muldoon

Dartmouth Scholarship

Humans and other primates are distinct among placental mammals in having exceptionally slow rates of growth, reproduction, and aging. Primates’ slow life history schedules are generally thought to reflect an evolved strategy of allocating energy away from growth and reproduction and toward somatic investment, particularly to the development and maintenance of large brains. Here we examine an alternative explanation: that primates’ slow life histories reflect low total energy expenditure (TEE) (kilocalories per day) relative to other placental mammals. We compared doubly labeled water measurements of TEE among 17 primate species with similar measures for other placental mammals. We found that …


Wii, Kinect, & Move. Heart Rate, Oxygen Consumption, Energy Expenditure, And Ventilation Due To Different Physically Active Video Game Systems In College Students., Krista C. Scheer, Sarah M. Siebrandt, Gregory A. Brown, Brandon S. Shaw, Ina Shaw Jan 2014

Wii, Kinect, & Move. Heart Rate, Oxygen Consumption, Energy Expenditure, And Ventilation Due To Different Physically Active Video Game Systems In College Students., Krista C. Scheer, Sarah M. Siebrandt, Gregory A. Brown, Brandon S. Shaw, Ina Shaw

International Journal of Exercise Science

International Journal of Exercise Science 7(1) : 22-32, 2014. Nintendo Wii, Sony Playstation Move, and Microsoft XBOX Kinect are home video gaming systems that involve player movement to control on-screen game play. Numerous investigations have demonstrated that playing Wii is moderate physical activity at best, but Move and Kinect have not been as thoroughly investigated. The purpose of this study was to compare heart rate, oxygen consumption, and ventilation while playing the games Wii Boxing, Kinect Boxing, and Move Gladiatorial Combat. Heart rate, oxygen consumption, and ventilation were measured at rest and during a graded exercise test in 10 …


Backward Position Shift In Apparent Motion, Hsin-Hung Li, Won Mok Shim, Patrick Cavanagh Jan 2014

Backward Position Shift In Apparent Motion, Hsin-Hung Li, Won Mok Shim, Patrick Cavanagh

Dartmouth Scholarship

We investigated the perceived position of visual targets in apparent motion. A disc moved horizontally through three positions from -10° to +10° in the far periphery (20° above fixation), generating a compelling impression of apparent motion. In the first experiment, observers compared the position of the middle of the three discs to a subsequently presented reference. Unexpectedly, observers judged its position to be shifted backward, in the direction opposite that of the motion. We then tested the middle disc in sequences of 3, 5, and 7 discs, each covering the same spatial and temporal extents (similar speeds). The backwards shift …


Contrast Negation Differentiates Visual Pathways Underlying Dynamic And Invariant Facial Processing, Pamela M. Pallett, Ming Meng Dec 2013

Contrast Negation Differentiates Visual Pathways Underlying Dynamic And Invariant Facial Processing, Pamela M. Pallett, Ming Meng

Dartmouth Scholarship

Abstract Bruce and Young (1986) proposed a model for face processing that begins with structural encoding, followed by a split into two processing streams: one for the dynamic aspects of the face (e.g., facial expressions of emotion) and the other for the invariant aspects of the face (e.g., gender, identity). Yet how this is accomplished remains unclear. Here, we took a psychophysical approach using contrast negation to test the Bruce and Young model. Previous research suggests that contrast negation impairs processing of invariant features (e.g., gender) but not dynamic features (e.g., expression). In our first experiment, participants discriminated differences in …


The Composite Effect For Inverted Faces Is Reliable At Large Sample Sizes And Requires The Basic Face Configuration, Tirta Susilo, Constantin Rezlescu, Bradley Duchaine Nov 2013

The Composite Effect For Inverted Faces Is Reliable At Large Sample Sizes And Requires The Basic Face Configuration, Tirta Susilo, Constantin Rezlescu, Bradley Duchaine

Dartmouth Scholarship

Abstract The absence of the face composite effect (FCE) for inverted faces is often considered evidence that holistic processing operates only on upright faces. However, such absence might be explained by power issues: Most studies that have failed to find the inverted FCE tested 24 participants or less. Here we find that the inverted FCE exists reliably when we tested at least 60 participants. The inverted FCE was ∼ 18% the size of the upright FCE, and it was unaffected by testing order: It did not matter whether participants did the upright condition first (Experiment 1, n = 64) or …


Dirigent Domain-Containing Protein Is Part Of The Machinery Required For Formation Of The Lignin-Based Casparian Strip In The Root, Prashant S. Hosmani, Takehiro Kamiya, John Danku, Sadaf Naseer, Niko Geldner, Mary Lou Guerinot, David Salt Aug 2013

Dirigent Domain-Containing Protein Is Part Of The Machinery Required For Formation Of The Lignin-Based Casparian Strip In The Root, Prashant S. Hosmani, Takehiro Kamiya, John Danku, Sadaf Naseer, Niko Geldner, Mary Lou Guerinot, David Salt

Dartmouth Scholarship

The endodermis acts as a "second skin" in plant roots by providing the cellular control necessary for the selective entry of water and solutes into the vascular system. To enable such control, Casparian strips span the cell wall of adjacent endodermal cells to form a tight junction that blocks extracellular diffusion across the endodermis. This junction is composed of lignin that is polymerized by oxidative coupling of monolignols through the action of a NADPH oxidase and peroxidases. Casparian strip domain proteins (CASPs) correctly position this biosynthetic machinery by forming a protein scaffold in the plasma membrane at the site where …


Colour And Odour Drive Fruit Selection And Seed Dispersal By Mouse Lemurs, Kim Valenta, Ryan J. Burke, Sarah A. Styler, Derek A. Jackson, Amanda D. Melin, Shawn M. Lehman Aug 2013

Colour And Odour Drive Fruit Selection And Seed Dispersal By Mouse Lemurs, Kim Valenta, Ryan J. Burke, Sarah A. Styler, Derek A. Jackson, Amanda D. Melin, Shawn M. Lehman

Dartmouth Scholarship

Animals and fruiting plants are involved in a complex set of interactions, with animals relying on fruiting trees as food resources, and fruiting trees relying on animals for seed dispersal. This interdependence shapes fruit signals such as colour and odour, to increase fruit detectability, and animal sensory systems, such as colour vision and olfaction to facilitate food identification and selection. Despite the ecological and evolutionary importance of plant-animal interactions for shaping animal sensory adaptations and plant characteristics, the details of the relationship are poorly understood. Here we examine the role of fruit chromaticity, luminance and odour on seed dispersal by …


Physiological Markers Of Phase Change In Heart Rate Response To Work, Ashleigh Welter, Cory Scott, Frank Wyatt Feb 2013

Physiological Markers Of Phase Change In Heart Rate Response To Work, Ashleigh Welter, Cory Scott, Frank Wyatt

International Journal of Exercise Science: Conference Proceedings

Heart rate response to increasing workload is accompanied by a series of physiologically marked stages, which can be identified through a linear and logarithmic regression line cross-over. These stages represent the withdrawal and activation of neural, hormonal and reflex mechanisms. However identification of physiological mechanisms associated with rate change is lacking in the literature. PURPOSE: The purpose of this study is to establish mathematical regression trend-lines for segmental changes in heart rate response to increased work, and identify the physiological mechanisms associated with said change. METHODS: Ten (n=10) male cyclists acted as subjects. Each signed a university approved …


A Novel Method For Comparative Analysis Of Retinal Specialization Traits From Topographic Maps, Bret A. Moore, Jason M. Kamilar, Shaun P. Collin, Olaf R. P. Bininda-Emonds, Nathaniel J. Dominy, Margaret I. Hall, Christopher P. Hessy, Sonke Johnsen, Thomas J. Lisney, Ellis R. Loew, Gillian Moritz Nov 2012

A Novel Method For Comparative Analysis Of Retinal Specialization Traits From Topographic Maps, Bret A. Moore, Jason M. Kamilar, Shaun P. Collin, Olaf R. P. Bininda-Emonds, Nathaniel J. Dominy, Margaret I. Hall, Christopher P. Hessy, Sonke Johnsen, Thomas J. Lisney, Ellis R. Loew, Gillian Moritz

Dartmouth Scholarship

Abstract Vertebrates possess different types of retinal specializations that vary in number, size, shape, and position in the retina. This diversity in retinal configuration has been revealed through topographic maps, which show variations in neuron density across the retina. Although topographic maps of about 300 vertebrates are available, there is no method for characterizing retinal traits quantitatively. Our goal is to present a novel method to standardize information on the position of the retinal specializations and changes in retinal ganglion cell (RGC) density across the retina from published topographic maps. We measured the position of the retinal specialization using two …


Salinity Preference Of Alaskan Threespine Stickleback: Test For Divergence In Halotaxis Between Ancestral And Landlocked Populations, David Fryxell, Eric T. Schultz Jan 2012

Salinity Preference Of Alaskan Threespine Stickleback: Test For Divergence In Halotaxis Between Ancestral And Landlocked Populations, David Fryxell, Eric T. Schultz

EEB Articles

Glacial retreat during the Pleistocene caused landlocking of anadromous Alaskan threespine stickleback, Gasterosteus aculeatus, furnishing a natural ‘experiment’ in osmoregulatory divergence. The objective of this study was to assess the effects of individual acclimation and population divergence on salinity preference. Full-sibling families of marine, anadromous, and freshwater-landlocked populations of stickleback were reared in common environments until 3 weeks post-hatch, then were split and acclimated to low or high salinity. At 6 to 8 weeks of age the six experimental groups were tested for salinity preference in a tank that offers fish a choice of compartments with different salinities arranged …


Minimum Cost Of Transport In Asian Elephants: Do We Really Need A Bigger Elephant?, V. A. Langman, M. F. Rowe, T. J. Roberts, N. V. Langman, C. R. Taylor Jan 2012

Minimum Cost Of Transport In Asian Elephants: Do We Really Need A Bigger Elephant?, V. A. Langman, M. F. Rowe, T. J. Roberts, N. V. Langman, C. R. Taylor

Dartmouth Scholarship

Body mass is the primary determinant of an animal’s energy requirements. At their optimum walking speed, large animals have lower mass-specific energy requirements for locomotion than small ones. In animals ranging in size from 0.8 g (roach) to 260 kg (zebu steer), the minimum cost of transport (COTmin) decreases with increasing body size roughly as COTmin∝body mass (Mb)–0.316±0.023 (95% CI). Typically, the variation of COTmin with body mass is weaker at the intraspecific level as a result of physiological and geometric similarity within closely related species. The interspecific relationship estimates that …