Physiology Commons^™

Short Communication: Relationship Between Body Growth And Mammary Development In Dairy Heifers, L F. Silva, M J. Vandehaar, Brian K. Whitlock, R P. Radcliff, H A. Tucker

Faculty Publications and Other Works -- Large Animal Clinical Sciences

Our objective was to determine if prepubertal rate of body weight (BW) gain, independent of diet, was related to mammary development of dairy heifers. Data from two studies recently conducted at Michigan State University were used to identify factors, within a dietary treatment group, that would account for variation in first lactation milk production or amount of mammary parenchymal DNA at the time of puberty. Factors analyzed for variation in milk production during first lactation were: postpartum BW, prepubertal BW gain, gestational BW gain, postpartum BW gain, body condition score (BCS) at breeding, and BCS at calving. Factors analyzed for …

A Long Way From Home: Transatlantic Sea Star Migration, William Jaeckle, Paul Kehle

Scholarship

For a marine biologist strolling along the eastern coast of South America, finding some sea stars (popularly called starfish, and technically members of the class Asteroidea of the phylum Echinodermata) is not all that unusual. However, when closer inspection reveals the sea stars to be ones that are also found on the shores of the western coast of Africa, the marine biologist now faces an interesting question: How did these sea stars come to be so far from home?

Originally published in Consortiumand used with permission.

Effects Of Two Backpack Weight Distributions On Perceptual And Physiological Measures During Walking, Katelyn Wells-Fahling

Masters Theses & Specialist Projects

Backpack weight distribution may affect economy by conserving energy and thus potentially prolonging fatigue. Research has not however examined effects of backpack weight distribution on subjective measures of intensity and comfort. Heart rate (HR) and overall and differentiated Ratings of Perceived Exertion (RPE) were examined during simulated backpacking with differentially weighted backpacks. Volunteers (n=27) completed two simulated hiking trials on a treadmill. Trials consisted of 15 minutes walking at 0% grade followed by 15 minutes walking at 10% grade at 2.5 mph (males) or 2.0 mph (females). Subjects wore an internal frame backpack packed to contain 25% of their individual …

Effect Of Dietary Protein On Prepubertal Mammary Development In Rapidly Growing Dairy Heifers, Brian K. Whitlock, M J. Vandehaar, L F. Silva, H A. Tucker

Faculty Publications and Other Works -- Large Animal Clinical Sciences

The objective was to determine whether increased dietary protein would enhance mammary development in prepubertal heifers fed for rapid body growth (1.2 kg/d). Fifty-four Holstein heifers (weighing approximately 134 kg) were assigned to one of three treatments. Heifers were fed a total mixed ration with metabolizable energy at 2.85 Mcal/kg and metabolizable protein at low, standard, or high concentrations (37, 41, or 44 g/Mcal of metabolizable energy, respectively) from 3.5 mo of age until slaughter at approximately 46 d after puberty. Heifers fed low, standard, and high protein gained 1130, 1170, and 1180 g/d, respectively. Dietary protein did not affect …

Unilateral Gynaecomastia--An Unusual Presentation Of Thyrotoxicosis, S Tauheed, M N. Haque

Department of Biological & Biomedical Sciences

No abstract provided.

Direct And Indirect Excitation Of Laterodorsal Tegmental Neurons By Hypocretin/Orexin Peptides: Implications For Wakefulness And Narcolepsy, Sophie Burlet, Christopher Tyler, Christopher S. Leonard

NYMC Faculty Publications

Compelling evidence links the recently discovered hypothalamic peptides Hypocretin/Orexin (Hcrt/Orx) to rapid eye movement sleep (REM) control and the sleep disorder narcolepsy, yet how they influence sleep-related systems is not well understood. We investigated the action of Hcrt/Orx on mesopontine cholinergic (MPCh) neurons of the laterodorsal tegmental nucleus (LDT), a target group whose function is altered in canine narcolepsy and appears pivotal for normal REM and wakefulness. Extracellular recordings from mouse brainstem slices revealed that Hcrt/Orx evoked prolonged firing of LDT neurons. Whole-cell recordings revealed that Hcrt/Orx had actions on both presynaptic neurons and at postsynaptic sites. Hcrt/Orx produced an …

A Motor And A Brake: Two Leg Extensor Muscles Acting At The Same Joint Manage Energy Differently In A Running Insect, Anna N. Ahn, Robert J. Full

All HMC Faculty Publications and Research

The individual muscles of a multiple muscle group at a given joint are often assumed to function synergistically to share the load during locomotion. We examined two leg extensors of a running cockroach to test the hypothesis that leg muscles within an anatomical muscle group necessarily manage (i.e. produce, store, transmit or absorb) energy similarly during running. Using electromyographic and video motion-analysis techniques, we determined that muscles 177c and 179 are both active during the first half of the stance period during muscle shortening. Using the in vivo strain and stimulation patterns determined during running, we measured muscle power output. …

Energetics Of Free-Ranging Seabirds, Hugh I. Ellis, Geir Wing Gabrielsen

Biology: Faculty Scholarship

No abstract provided.

Dwarf Peppers: Evaluation Of ‘Triton’, Usu Crop Physiology Lab

Dwarf Crops

In November, 2001 through a connection with Mary Musgrave at University of Massachusetts, the sweet pepper ‘Triton’ was identified. ‘Triton’ is only 20-cm tall, flowers in 25 days, and produces large (~5 to 8 cm long) fruit. We are now characterizing the yield and environmental response of ‘Triton’. Additionally, seed will be collected from mature fruit and will be included in our dwarf seed outreach program run primarily though our web page. We are attempting to find the genetic origin of ‘Triton’.

The Impact Of Burnout On Human Physiology And On Operational Performance: A Prospective Study Of Soldiers Enrolled In The Combat Diver Qualification Course, Charles A. Morgan Iii, Tracey Cho, Gary Hazlett, Vladimir Coric, Jeff Morgan

National Security Faculty Publications

(from p. 201) "If little is known about the pathophysiology of burnout, even less is known about the actual impact of burnout on military operational performance. This is due to a lack of studies focused on military performance. Whether or not soldiers may feel symptoms of burnout is one thing - whether this state actually affects how they do their job is another. Within the current environment (reduced forces, increased training rates, increased deployment rates, extended tours) we believe that military personnel may be at significant risk for the development of burnout. Further, we wondered if there was a demonstrable …

Ethological Causes And Consequences Of The Stress Response, Neil Greenberg, James A. Carr, Cliff H. Summers

Faculty Publications and Other Works -- Ecology and Evolutionary Biology

Stress involves real or perceived changes within an organism or in the environment that activate an organism’s attempts to cope by means of evolutionarily ancient neural and endocrine mechanisms. Responses to acute stressors involve catecholamines released in varying proportion at different sites in the sympathetic and central nervous systems. These responses may interact with and be complemented by intrinsic rhythms and responses to chronic or intermittent stressors involving the hypothalamic-pituitary-adrenal axis. Varying patterns of responses to stressors are also affected by an animal=s assessment of their prospects for successful coping. Subsequent central and systemic consequences of the stress response include …