Physiology Commons^™

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 …

Sleep Patterns In Collegiate Dancers, Beth Nicks, Jacque Price

e-Research: A Journal of Undergraduate Work

As college dance majors, the investigators have witnessed firsthand the effects that sleep and the lack thereof can have on the performance quality of University level dancing. It has been shown that lack of sleep can compromise nearly every physiological process such as memory, coordination, metabolism, and new learning (Wozny 2008). Studies on disruptions of the human circadian rhythms have shown that athletes involved in endeavors where sleep is restricted or totally deprived have severe consequences on behavior and performance. (Edwards 2007). However, the environment of college dance programs is different than athletics due to there being no off season. …

Mistranslation Of The Genetic Code, Adil Moghal, Kyle Mohler, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

During mRNA decoding at the ribosome, deviations from stringent codon identity, or “mistranslation,” are generally deleterious and infrequent. Observations of organisms that decode some codons ambiguously, and the discovery of a compensatory increase in mistranslation frequency to combat environmental stress have changed the way we view “errors” in decoding. Modern tools for the study of the frequency and phenotypic effects of mistranslation can provide quantitative and sensitive measurements of decoding errors that were previously inaccessible. Mistranslation with non‐protein amino acids, in particular, is an enticing prospect for new drug therapies and the study of molecular evolution.

Relaxed Substrate Specificity Leads To Extensive Trna Mischarging By Streptococcus Pneumoniae Class I And Class Ii Aminoacyl-Trna Synthetases, Jennifer Shepherd, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Aminoacyl-tRNA synthetases provide the first step in protein synthesis quality control by discriminating cognate from noncognate amino acid and tRNA substrates. While substrate specificity is enhanced in many instances by cis- and trans-editing pathways, it has been revealed that in organisms such as Streptococcus pneumoniae some aminoacyl-tRNA synthetases display significant tRNA mischarging activity. To investigate the extent of tRNA mischarging in this pathogen, the aminoacylation profiles of class I isoleucyl-tRNA synthetase (IleRS) and class II lysyl-tRNA synthetase (LysRS) were determined. Pneumococcal IleRS mischarged tRNA^Ile with both Val, as demonstrated in other bacteria, and Leu in a tRNA sequence-dependent …

An Intronic Picalm Polymorphism, Rs588076, Is Associated With Allelic Expression Of A Picalm Isoform, Ishita Parikh, Christopher Medway, Steven Younkin, David Fardo, Steven Estus

Physiology Faculty Publications

BACKGROUND: Although genome wide studies have associated single nucleotide polymorphisms (SNP)s near PICALM with Alzheimer's disease (AD), the mechanism underlying this association is unclear. PICALM is involved in clathrin-mediated endocytosis and modulates Aß clearance in vitro. Comparing allelic expression provides the means to detect cis-acting regulatory polymorphisms. Thus, we evaluated whether PICALM showed allele expression imbalance (AEI) and whether this imbalance was associated with the AD-associated polymorphism, rs3851179.

RESULTS: We measured PICALM allelic expression in 42 human brain samples by using next-generation sequencing. Overall, PICALM demonstrated equal allelic expression with no detectable influence by rs3851179. A single sample demonstrated …

Translation Initiation Rate Determines The Impact Of Ribosome Stalling On Bacterial Protein Synthesis, Steven J. Hersch, Sara Elgamal, Assaf Katz, Michael Ibba, William Wiley Navarre

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Ribosome stalling during translation can be caused by a number of characterized mechanisms. However, the impact of elongation stalls on protein levels is variable, and the reasons for this are often unclear. To investigate this relationship, we examined the bacterial translation elongation factor P (EF-P), which plays a critical role in rescuing ribosomes stalled at specific amino acid sequences including polyproline motifs. In previous proteomic analyses of both Salmonella and Escherichia coli efp mutants, it was evident that not all proteins containing a polyproline motif were dependent on EF-P for efficient expression in vivo . The α- and β-subunits of …

Ef-P Dependent Pauses Integrate Proximal And Distal Signals During Translation, Sara Elgamal, Assaf Katz, Steven J. Hersch, David Newsom, Peter White, William Wiley Navarre, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Elongation factor P (EF-P) is required for the efficient synthesis of proteins with stretches of consecutive prolines and other motifs that would otherwise lead to ribosome pausing. However, previous reports also demonstrated that levels of most diprolyl-containing proteins are not altered by the deletion of efp. To define the particular sequences that trigger ribosome stalling at diprolyl (PPX) motifs, we used ribosome profiling to monitor global ribosome occupancy in Escherichia coli strains lacking EF-P. Only 2.8% of PPX motifs caused significant ribosomal pausing in the Δefp strain, with up to a 45-fold increase in ribosome density observed at …

The Effect Of Maternal Aldosterone Levels On The Expression Of 11b-Hsd Isoenzymes In Normal And Hypertensive Rat Placentae, Nicole Jorissen

Journal of Undergraduate Research at Minnesota State University, Mankato

In this project, we developed a Western blotting procedure to semi-quantitate levels of 11β-HSD1 and 11β-HSD2 in whole cell extracts. Then, we applied this technique to analyze the effect of reduced maternal aldosterone levels on the expression of 11β-HSD1 and 11β-HSD2 isoenzymes in the placental tissue in both normal and hypertensive rats. These enzymes control levels of glucocorticoids which compete for aldosterone’s mineralocorticoid receptor. Overstimulation of this receptor results in hypertension. If aldosterone levels decrease, levels of the enzymes controlling active glucocorticoid concentrations might change to compensate for the lowered aldosterone levels. Decreased placental 11β-HSD2 expression could affect hypertension in …

Cryopreservation Of Hepatocyte (Hepg2) Cell Monolayers: Impact Of Trehalose, Blake Stokich, Quinn Osgood, David Grimm, Shhyam Moorthy, Nilay Chakraborty, Michael A. Menze

Faculty Research & Creative Activity

A simple method to cryogenically preserve hepatocyte monolayers is currently not available but such a technique would facilitate numerous applications in the field of biomedical engineering, cell line development, and drug screening. We investigated the effect of trehalose and dimethyl sulfoxide (Me2SO) in cryopreservation of human hepatocellular carcinoma (HepG2) cells in suspension and monolayer formats. HepG2 cell monolayers were incubated for 24 h at varying concentrations of trehalose (50–150 mM) prior to cryopreservation to identify the optimum concentration for such preincubation. When trehalose alone was used as the cryoprotective agent (CPA), cells in monolayer format did not survive freezing while …

Cryopreservation Of Hepatocyte (Hepg2) Cell Monolayers: Impact Of Trehalose, Blake Stokich, Quinn Osgood, David Grimm, Shhyam Moorthy, Nilay Chakraborty, Michael Menze

Faculty and Staff Scholarship

A simple method to cryogenically preserve hepatocyte monolayers is currently not available but such a technique would facilitate numerous applications in the field of biomedical engineering, cell line development, and drug screening. We investigated the effect of trehalose and dimethyl sulfoxide (Me2SO) in cryopreservation of human hepatocellular carcinoma (HepG2) cells in suspension and monolayer formats. HepG2 cell monolayers were incubated for 24 h at varying concentrations of trehalose (50–150 mM) prior to cryopreservation to identify the optimum concentration for such preincubation. When trehalose alone was used as the cryoprotective agent (CPA), cells in monolayer format did not survive freezing while …

Melanin As An Oto-Protective Pigment In Two Fish Species: Poecilia Latipinna And Cyprinus Carpio , Bethany N. Coffey

Masters Theses & Specialist Projects

Melanin is the dark pigment found in most organisms that gives color to the skin, hair, feathers, and eyes of vertebrates. While melanin is known to also be present in the stria vascularis of the mammalian cochlea, its function in the inner ear is still unknown. Some previous studies have indicated that melanin may serve to protect the mammalian ear from hearing loss. Minimal previous research on melanin within the inner ears of fishes has been conducted. In this study, the melanin levels in the inner ears of different color morphs of two fish species (Poecilia latipinna and Cyprinus …

Physiological Effects Of A Kettlebell Workout Versus A High-Resistance Circuit Workout, Brett Schreiber

Graduate Theses and Dissertations

Purpose: To compare the physiological effects of a single kettlebell workout to a high-resistance circuit workout in resistance-trained males. Methods: 12 resistance trained healthy males (age: 24 ± 2.97 years; height: 1.75 ± 0.064 m; body mass: 75.99 ± 8.46 kg) participated in this study. Participants had a familiarization visit and two subsequent experimental visits (kettlebell workout; circuit workout). The kettlebell workout consisted of 12-minutes of standardized kettlebell swings. The circuit workout consisted of three sets of 6 repetitions of smith machine squats, bench press, leg curl, and lat pulldown. Heart rate, rectal temperature, skin temperature, blood lactate, rating of …

Mirna-21 Has Anti-Inflammatory Effects In The Macrophage Response To Peritonitis., Rebecca Elise Barnett

Electronic Theses and Dissertations

This project investigated the role of miRNA-21 in the macrophage response to peritonitis; with the goal of understanding whether the associated mechanism has potential benefits in the clinical treatment of peritonitis. A novel therapeutic intervention in the treatment of peritonitis could modulate the host immune response to decrease an exaggerated pro-inflammatory innate response and then prevent or ameliorate the development of sepsis and organ failure. We found the following: 1. MiRNA-21 expression increases in peritoneal macrophages after lipopolysaccharide (LPS) stimulation. 2. Over expression of miRNA-21 decreases TNF-a secretion from macrophages after LPS stimulation. Suppression of miRNA-21 expression results in increased …

Balance And Power In Older Adults With And Without A History Of Falls, Stephanie Michelle Gray

Graduate Theses and Dissertations

The purpose of this study was to observe the differences between power and balance in older adults over the age of 65 with and without falls. A total of 62 community dwelling older adults between the ages of 65 and 92 participated in the study. Two groups consisted of 25 fallers and 37 non-fallers. No statistical differences were found between groups on age, height, weight, or BMI. Testing included the Berg Balance Scale (BBS) to test balance, the Tendo Weightlifting Analyzer (TWA) during a sit-to-stand to test lower body power, and the Physical Activity Scale for the Elderly (PASE) to …

The Effect Of Leucine Supplementation On Biomarkers Of Mitochondrial Biogenesis And Protein Synthesis In Soleus Muscle Of Rats Fed A High-Fat Diet, Gina Davis

Graduate Theses and Dissertations

Mitochondrial dysfunction is a contributing factor to the advancement of various diseases including obesity, diabetes, and cardiovascular disease. Impairment in mitochondria brings about a diminished mitochondrial number and oxidative capacity. Leucine is known to stimulate muscle protein synthesis through transcription and translation of nuclear DNA leading to increases in mitochondrial biogenesis and fatty acid oxidation. However, the effects of leucine on anabolic factors of the mitochondrial genome, during catabolic conditions are not known. PURPOSE: To determine if leucine supplementation alters the negative effects of a high fat (60%) diet (HFD) on the mitochondrial genome by measuring the gene expression of …

Effects Of Breathing Cool Air During Cycling Exercise In The Heat, Christian B. Ridings

Graduate Theses and Dissertations

INTRODUCTION: The purpose of this study was to establish the ability of the Core Cooler device to prevent rises in physiological heat strain of trained male cyclists during cycling exercise in the heat. METHODS: 15 healthy male cyclists cycled at 50-70% VO2max for 75 minutes in a heat chamber of 31°C & 55% RH while breathing through the Core Cooler device under three different conditions: 1:4 ratio without ice termed control (CN), 1:4 ratio with ice termed low intermittent (LI), and at 1:1 ratio with ice termed high intermittent (HI). Data collected every 15 minutes assessing intestinal temperature (TGI), heart …

A Comparison Of Fatigue During Cardiocerebral Resuscitation With Different Compression Rates Among Layperson And Professional Rescuers, Christopher Cassidy

Master's Theses

Quality chest compressions during Cardiopulmonary Resuscitation (CPR) are vital to maintaining adequate perfusion of oxygenated blood to the organs of the body to sustain life. Over the years, the compression rate recommended in Basic Life Support (BLS)/ Advanced Cardiac Life Support (ACLS) protocols for the best possible outcome has risen, and with that increase there are questions regarding rescuer fatigue and the effectiveness of compressions. Layperson and professional rescuers, answering to an emergency, both maintain continuous chest compressions until advanced life support arrives. Depending on the location, this arrival time would most likely be longer than the two minute standard …

Acute Testosterone Responses To Different Resistance Exercise Intensities, Robert Rietjens

UNLV Theses, Dissertations, Professional Papers, and Capstones

We investigated the acute testosterone response to four different resistance-training protocols. We observed testosterone levels pre-workout, immediately post-workout, and 60-minutes post-workout following a bout of upper body exercise at 70%,1 RM, 90% 1 RM, and lower body exercise at 70% 1 RM and 90% 1 RM. Total training volume was held constant but all amount of weight, sets, and reps were different. 10 healthy, male, resistance trained individuals volunteered for the study. The performed each exercise condition on separate days. Capillary blood was taken via finger prick at the time points specified above. Blood samples were analyzed via Accubind Testosterone …

Influence Of Steroids And Gonadotropins On Reproduction In Beef Cattle, Thomas L. Devine

Graduate Theses and Dissertations

The objective of this thesis was to evaluate the influence of steroids and gonadotropins on reproduction in beef cattle. In experiment 1, beef heifers were used to determine the influence of growth-promoting implants on growth, reproductive development, estrous behavior, and pregnancy rate. Heifers were assigned to 1 of 4 implant treatment groups: control (CON); trenbolone acetate (TBA); trenbolone acetate plus estradiol (TBA+E2) or zeranol (ZER). Heifers were implanted once, A.I. and exposed to bull during this experiment. Body weight, BCS, HH, RTS, estrous behavior and pregnancy data were collected throughout this experiment. Average daily gain of heifers was greater for …

Osteoblast Oncostatin M Signaling In Modeled Spaceflight, Jacob Goyden

Boise State University Theses and Dissertations

Bone deterioration is a challenge in long-term spaceflight with significant connections to terrestrial disuse bone loss. Prolonged unloading and radiation exposure, defining characteristics of space travel, have both been associated with changes in inflammatory signaling via IL-6 class cytokines in bone. While there is also some evidence for perturbed IL-6 class signaling in spaceflight, there has been scant examination of the connections between free fall, radiation, and inflammatory stimuli in bone. Our lab and others have shown that the IL-6 class cytokine oncostatin M (OSM) is an important regulator of bone remodeling. We hypothesize that spaceflight alters osteoblast OSM signaling, …