Physiology Commons^™

Enabling Real-Time Ultrasound Imaging Of Soft Tissue Mechanical Properties By Simplification Of The Shear Wave Motion Equation, Aaron J. Engel, Gregory R. Bashford

Biomedical Imaging and Biosignal Analysis Laboratory

Ultrasound based shear wave elastography (SWE) is a technique used for non-invasive characterization and imaging of soft tissue mechanical properties. Robust estimation of shear wave propagation speed is essential for imaging of soft tissue mechanical properties. In this study we propose to estimate shear wave speed by inversion of the firstorder wave equation following directional filtering. This approach relies on estimation of first-order derivatives which allows for accurate estimations using smaller smoothing filters than when estimating second-order derivatives. The performance was compared to three current methods used to estimate shear wave propagation speed: direct inversion of the wave equation (DIWE), …

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 …

Tradeoffs Of Warm Adaptation In Aquatic Ectotherms: Live Fast, Die Young?, Eloy Martinez, Anthony Porreca, Robert Colombo, Michael Menze

Faculty Research & Creative Activity

In the face of a changing climate, questions regarding sub-lethal effects of elevated habitat temperature on the physiology of ectotherms remain unanswered. In particular, long-term responses of ectotherms to the warming trend in tropical regions are unknown, and understudied due to the difficulties in specimen and community traceability. In freshwater lakes employed as cooling reservoirs for power plants, increased physiological stress from high water temperature can potentially alter the community structure of fishes. We employ this highly tractable system to assess how thermal regimes can alter the physiology and ecology of aquatic species. We documented a significantly reduced lifespan, growth …

Physiological Performance Of Warm-Adapted Marine Ectotherms: Thermal Limits Of Mitochondrial Energy Transduction Efficiency, Eloy Martinez, Eric Hendricks, Michael Menze, Joseph Torres

Faculty Research & Creative Activity

Thermal regimes in aquatic systems have profound implications for the physiology of ectotherms. In particular, the effect of elevated temperatures on mitochondrial energy transduction (i.e. energy from carbon substrates to ATP) in tropical and subtropical teleosts may have profound consequences on organismal performance and population viability. Upper and lower whole-organism critical temperatures for teleosts suggest that subtropical and tropical species are not susceptible to the warming trends associated with climate change, but sub-lethal effects on energy transduction efficiency and population dynamics remain unclear. The goal of the present study was to compare the thermal sensitivity of processes associated with mitochondrial …

'In' Or 'As' Space?: A Model Of Complexity, With Philosophical, Simulatory, And Empirical Ramifications, Charles H. Smith

DLPS Faculty Publications

A General Systems model based on ideas originating with the writings of Benedict de Spinoza is described, starting with its philosophical underpinnings, and proceeding on to its relation to modern systems concepts, including attempts to simulate the relationships posed, and measure real world structures. Central to the idea is the notion that spatial extension may not have a prior existence, but emerges only through an entropy maximization process in which information and energy exchange is balanced among some limited number of subsystems that in sum comprise any given functioning complex system. Related published empiricism concerning geographical/geological systems – the hypsometry …

Acute Toxicity Assessment Of N,N-Diethyl-M-Toluamide (Deet) On The Photosynthetic Activity Of The Dinoflagellate Gymnodinium Instriatum, Eloy Martinez, Sylvia Velez, Marietta Mayo, Miguel Sastre

Faculty Research & Creative Activity

Despite the ubiquitous occurrence of N, N-diethyl-m-toluamide (DEET) in aquatic systems, assessments evaluating the toxicity of DEET on phytoplankton species are summed to a single study on a unicellular green alga. In particular, the toxicological effects of DEET in dinoflagellates are unknown. In this study, we employed the mixotrophic dinoflagellate Gymnodinium instriatum as a study system to evaluate acute effects of DEET on the oxygen flux of laboratory cultures. This study reports an inhibitory reaction model of DEET described by the equation y = 4.99 x 0.54, where y represents the percent inhibition of oxygen flux and x represents DEET …

Correlations Between Sensory Encoding And Central Morphology Of Muscle Proprioceptors In The Rat, Hanna Marie Gabriel

Browse all Theses and Dissertations

Until now, observations regarding the central morphology and organization of Ia, group II and Ib Golgi tendon organ afferents have been confined to the cat model. As the use of rodents in the study of the development and organization of segmental spinal cord circuitry increases, a complete account of the peripheral encoding and central connectivity of rodent muscle proprioceptors is necessary. The data presented in this study establish the central morphology and spatial distribution of 12 (4 of each class) functionally phenotyped muscle proprioceptor afferents in the rat by intracellular labeling with Neurobiotin. Each afferent type showed a characteristic central …

Functional Transcranial Doppler Ultrasound For High Temporal Resolution Measurement Of Lateralization In Visual Memory And Visual Search Cognitive Tasks, B. Hage, M. Alwatban, E. Barney, M. Mills, M. Dodd, E. Truemper, Gregory R. Bashford

Biomedical Imaging and Biosignal Analysis Laboratory

Functional transcranial Doppler ultrasound (fTCD) is a noninvasive sensing modality that measures blood flow velocities in cerebral arteries (CBFV) with high temporal resolution. Few studies have examined the relationship of CBFV change during visual search and visual memory cognitive tasks. Here a protocol to compare lateralization between these two similar tasks using fTCD is demonstrated. Thirteen healthy volunteers were shown visual scenes on a computer and performed visual search and visual memory tasks while CBFV in the bilateral middle cerebral arteries was monitored with fTCD. Each subject completed 40 trials, consisting of baseline, calibration, instruction, and task periods. Lateralization was …

Effect Of The Acute Stress Response On Foraging Behavior In Mountain White-Crowned Sparrows, Zonotrichia Leucophrys, Sarah C. Osborne

Scripps Senior Theses

Free-living vertebrates likely encounter many stressors throughout their lifetime, from fighting off a predator to coping with unpredictable weather. As a result, vertebrates will mount an acute response to the stressors. Here, we outline previous research conducted in behavioral endocrinology and stress physiology as it relates to our research. We then discuss our study with white-crowned sparrows (Zonotrichia leucophrys) in Tioga Pass Meadow, in which we examined how the acute stress response affects foraging behavior 24 hours after a stressor. In birds that underwent a stress series, we found there to be a significant 57% decrease in foraging …

Awareness Of Diabetes Risk Associated With Individuals 18 And Older, Rebecca Jane Boone

Walden Dissertations and Doctoral Studies

The risk of developing Type 2 diabetes is increasing at epidemic proportions, and is 12-17% higher in Marion County Florida than it is across the state, based on Florida Department of Health statistics. The purpose of this DNP project was to determine if awareness of individual risk of developing Type 2 diabetes through a questionnaire would result in high-risk participants agreeing to attend a diabetes prevention program (DPP) at a local medical clinic. The health belief model and Rosswurm and Larrabee's model for change were used as frameworks. The review of the literature showed that prevention programs were highly effective …

Mechanisms Of Estrogen Receptor Alternative Splicing And The Consequences For Aging In The Female Brain, Cody Lee Shults

Dissertations

The advances in healthcare and scientific knowledge have resulted in longer life expectancies in women. These advanced ages in women now means that they are experiencing the effects of age-related changes in the body for much longer periods of time, mainly reproductive senescence, resulting in the loss of circulating ovarian hormones. The age at which menopause occurs has not changed, resulting in women now living over a third of their lives in a postmenopausal state.

The major circulating estrogen produced by the ovaries, 17β-estradiol (E2), has many homeostatic effects in the body like neuroprotection and cardioprotection. Hormone replacement therapy (HT) …

The Effects On Acute Power Production Enhancement And Maintenance Due To Pre-Workout Supplementation In Recreationally Trained College Aged Males., Mark Travis Byrd

Online Theses and Dissertations

Introduction: The current research in power production has shown the use of pre-workout supplements to increase peak power production, but the current research has not yet been able to delve in to the effectiveness of pre-workout supplementation on maintaining power production.

Purpose: The purpose of this study was to examine the effects on acute power production enhancement and maintenance due to supplementation in recreationally trained college aged individuals.

Methods: Data was collected from 13 recreationally trained, college-aged males in a double-blind crossover study. After a familiarization sessions subjects participated in three testing sessions utilizing a cross over double blind design …

Effects Of A Six-Week Functional Training Program On Fitness And Body Composition Of Fire Science Majors, Kristen Anne Lebrun

Online Theses and Dissertations

Introduction: The leading cause of on duty death of firefighters is sudden cardiac events. Current research has shown the effects of fire physical training programs on firefighters, but has not researched fire specific physical training programs for the fire science major population. Purpose: The purpose of this study was to examine the effects of a six-week functional program on fitness and body composition of fire science majors. Methods: Fire science college students (N = 16) volunteered to take part in a six-week fire specific fitness program. The subjects that fully completed the study (N = 12) were randomly assigned to …

Transfer Rna Comes Of Age, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

"The year the journal RNA was founded was slated by some in scientific publishing to be the year that one particular type of RNA's run in the spotlight would end. In 1995 I had recently started as a post-doc with Dieter Söll at Yale when he came into the lab to solemnly inform us all that an editor at a certain (S)cience journal had just told him “we won't be publishing any more tRNA papers.” For a post-doc who had migrated across the Atlantic for the sole purpose of furthering his career by working on tRNA this was not great …

Bracing Of The Trunk And Neck Has A Differential Effect On Head Control During Gait, S. Morrison, D. M. Russell, K. Kelleran, M. L. Walker

Rehabilitation Sciences Faculty Publications

During gait, the trunk and neck are believed to play an important role in dissipating the transmission of forces from the ground to the head. This attenuation process is important to ensure head control is maintained. The aim of the present study was to assess the impact of externally restricting the motion of the trunk and/or neck segments on acceleration patterns of the upper body and head and related trunk muscle activity. Twelve healthy adults performed three walking trials on a flat, straight 65-m walkway, under four different bracing conditions: 1) control-no brace; 2) neck-braced; 3) trunk-braced; and 4) neck-trunk …

The Reproductive Cycle Of The Guatemalan Beaded Lizard, Heloderma Charlesbogerti, Wade C. Carruth Iii

College of Graduate Studies: Theses & Dissertations

Reproductive information, including seasonality in behavior and physiology, is key to our ability to breed species for maintaining assurance colonies or for future introductions. Limited scientific data is available about the reproduction of Helodermatid lizards. Several species of helodermatid lizard are uncommon, rare, or simply exist at low population densities and in need of the development of conservation programs and management. Most helodermatid reproductive data collected to date has been done on deceased animals using histological techniques. Until this study, no hormones have been analyzed, and individual animals have not been followed through a complete cycle. The purpose of this …

The Physiological Stress Response Caused By Hypoxia And Reperfusion Injury In Striped Bass (Morone Saxatilis) And Nile Tilapia (Oreochromis Niloticus), Amanda C. Reynolds

College of Graduate Studies: Theses & Dissertations

Approximately five million people in the United States are affected by cardiovascular related diseases yearly contributing to 300,000 annual deaths, making CVD the leading cause of mortality worldwide. It has been suggested that apoptosis (programmed cell death) contributes to the pathogenesis of cardiovascular diseases. When blood flow is reduced or cut off from the heart, usually by a thrombus, this results in oxygen deprivation (hypoxia) to the cardiomyocytes (heart cells). In response to this hypoxic stress, cardiomyocytes will undergo apoptosis. Since many species of fish can survive levels of hypoxia that would be fatal to mammals, fish are an ideal …

Introduction To Fifth Special Issue On Electroporation-Based Technologies And Treatments, Damijan Miklavčič, Lluis M. Mir, P. Thomas Vernier

Bioelectrics Publications

This special issue of the Journal of Membrane Biology contains reports on recent developments in the field of electroporation by participants in the International Workshop and Postgraduate Course on Electroporation-Based Technologies and Treatments held in November 2014 in Ljubljana. This was the eighth session of what is now an annual event, first organized in 2003.

Gait Intervention For Improvements In Human Top Speed Running, Michelle Buechner

Graduate Student Theses, Dissertations, & Professional Papers

Between individuals faster sprinting speeds are achieved by applying greater stance average forces against the running surface. Recent evidence further indicates that elite level performers also strike the ground with leg kinematics that differ from those of non-elites and that these leg movements act to enhance the force transients occurring in the milliseconds following foot-ground impact. I investigated whether sprint performance could be enhanced through a short term gait intervention, consisting of 3 laboratory training sessions wherein subjects (n = 6) completed 5 high-speed runs on an instrumented force treadmill at 90% of their measured top sprint. The subjects received …

Picosecond To Terahertz Perturbation Of Interfacial Water And Electropermeabilization Of Biological Membranes, P. Thomas Vernier, Zachary A. Levine, Ming-Chak Ho, Shu Xiao, Iurii Semenov, Andrei G. Pakhomov

Bioelectrics Publications

Non-thermal probing and stimulation with subnanosecond electric pulses and terahertz electromagnetic radiation may lead to new, minimally invasive diagnostic and therapeutic procedures and to methods for remote monitoring and analysis of biological systems, including plants, animals, and humans. To effectively engineer these still-emerging tools, we need an understanding of the biophysical mechanisms underlying the responses that have been reported to these novel stimuli. We show here that subnanosecond (≤500 ps) electric pulses induce action potentials in neurons and cause calcium transients in neuroblastoma-glioma hybrid cells, and we report complementary molecular dynamics simulations of phospholipid bilayers in electric fields in which …