The effects of oil contamination and cleaning on sea otters (Enhydra lutris). II. Metabolism, thermoregulation, and behavior

1988 ◽  
Vol 66 (12) ◽  
pp. 2782-2790 ◽  
Author(s):  
R. W. Davis ◽  
T. M. Williams ◽  
J. A. Thomas ◽  
R. A. Kastelein ◽  
L. H. Cornell

The purpose of this study was to develop a method to clean and rehabilitate sea otters (Enhydra lutris) that might become contaminated during an oil spill and to determine which physiological and behavioral factors were important in restoring the insulation provided by the fur. Tests were conducted on 12 sea otters captured in Alaska and brought to the Sea World Research Institute in San Diego. Measurements of average metabolic rate, core body temperature, behavior, and squalene (the major lipid of sebum) concentration on the fur were made under three conditions: (i) before oiling (base line), (ii) 1–3 days after 20% of the body surface area was covered with fresh crude oil, and (iii) after cleaning. Under base-line conditions in water at 13 °C, average metabolic rate was 8.0 W/kg, core body temperature was 38.9 °C, and whole body thermal conductance was 10.7 W/(m2∙ °C). Otters spent 35% of their time grooming, 45% resting, 10% swimming, and 10% feeding. The squalene concentration on the fur averaged 3.7 mg/g fur. Oiling increased thermal conductance 1.8 times. To compensate for the loss of insulation and maintain a normal core body temperature (39 °C), the otters increased average metabolic rate (1.9 times) through voluntary activity and shivering; the time spent grooming and swimming increased 1.7 times. Using Dawn detergent, we were able to clean the oiled fur during 40 min of washing and rinsing. Grooming activity by the otters was essential for restoring the water-repellent quality of the fur. Core body temperature, average metabolic rate, and thermal conductance returned to base-line levels 3–6 days after cleaning. Squalene was removed by cleaning and did not return to normal levels in the oiled area after 7 days. Veterinary care was important to keep the otters healthy. At least 1–2 weeks should be allowed for otters to restore the insulation of their fur and for recovery from the stress of oiling and cleaning.

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Robins T. Kalathil ◽  
Gavin A. D'Souza ◽  
Amit Bhattacharya ◽  
Rupak K. Banerjee

Heat stress experienced by firefighters is a common consequence of extreme firefighting activity. In order to avoid the adverse health conditions due to uncompensable heat stress, the prediction and monitoring of the thermal response of firefighters is critical. Tissue properties, among other parameters, are known to vary between individuals and influence the prediction of thermal response. Further, measurement of tissue properties of each firefighter is not practical. Therefore, in this study, we developed a whole body computational model to evaluate the effect of variability (uncertainty) in tissue parameters on the thermal response of a firefighter during firefighting. Modifications were made to an existing human whole body computational model, developed in our lab, for conducting transient thermal analysis for a firefighting scenario. In conjunction with nominal (baseline) tissue parameters obtained from literature, and physiologic conditions from a firefighting drill, the Pennes' bioheat and energy balance equations were solved to obtain the core body temperature of a firefighter. Subsequently, the uncertainty in core body temperature due to variability in the tissue parameters (input parameters), metabolic rate, specific heat, density, and thermal conductivity was computed using the sensitivity coefficient method. On comparing the individual effect of tissue parameters on the uncertainty in core body temperature, the metabolic rate had the highest contribution (within ±0.20 °C) followed by specific heat (within ±0.10 °C), density (within ±0.07 °C), and finally thermal conductivity (within ±0.01 °C). A maximum overall uncertainty of ±0.23 °C in the core body temperature was observed due to the combined uncertainty in the tissue parameters. Thus, the model results can be used to effectively predict a realistic range of thermal response of the firefighters during firefighting or similar activities.


Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2316
Author(s):  
Daniel Mota-Rojas ◽  
Dehua Wang ◽  
Cristiane Gonçalves Titto ◽  
Jocelyn Gómez-Prado ◽  
Verónica Carvajal-de la Fuente ◽  
...  

Body-temperature elevations are multifactorial in origin and classified as hyperthermia as a rise in temperature due to alterations in the thermoregulation mechanism; the body loses the ability to control or regulate body temperature. In contrast, fever is a controlled state, since the body adjusts its stable temperature range to increase body temperature without losing the thermoregulation capacity. Fever refers to an acute phase response that confers a survival benefit on the body, raising core body temperature during infection or systemic inflammation processes to reduce the survival and proliferation of infectious pathogens by altering temperature, restriction of essential nutrients, and the activation of an immune reaction. However, once the infection resolves, the febrile response must be tightly regulated to avoid excessive tissue damage. During fever, neurological, endocrine, immunological, and metabolic changes occur that cause an increase in the stable temperature range, which allows the core body temperature to be considerably increased to stop the invasion of the offending agent and restrict the damage to the organism. There are different metabolic mechanisms of thermoregulation in the febrile response at the central and peripheral levels and cellular events. In response to cold or heat, the brain triggers thermoregulatory responses to coping with changes in body temperature, including autonomic effectors, such as thermogenesis, vasodilation, sweating, and behavioral mechanisms, that trigger flexible, goal-oriented actions, such as seeking heat or cold, nest building, and postural extension. Infrared thermography (IRT) has proven to be a reliable method for the early detection of pathologies affecting animal health and welfare that represent economic losses for farmers. However, the standardization of protocols for IRT use is still needed. Together with the complete understanding of the physiological and behavioral responses involved in the febrile process, it is possible to have timely solutions to serious problem situations. For this reason, the present review aims to analyze the new findings in pathophysiological mechanisms of the febrile process, the heat-loss mechanisms in an animal with fever, thermoregulation, the adverse effects of fever, and recent scientific findings related to different pathologies in farm animals through the use of IRT.


2015 ◽  
Vol 16 ◽  
pp. S186-S187 ◽  
Author(s):  
I. Park ◽  
M. Kayaba ◽  
K. Iwayama ◽  
H. Ogata ◽  
Y. Sengoku ◽  
...  

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Dikmen S ◽  
Davila KMS ◽  
Rodriquez E ◽  
Scheffler TL ◽  
Oltenacu PA ◽  
...  

In cattle, core body temperature can be used as an important indicator of heat stress level. However, accurately recording core body temperature can be difficult and labor intensive. The objectives of the current study were 1) to compare the recorded tympanic and tail body temperature measurements in steers and 2) to determine the body temperature change of Angus and Brahman steers in a hot and humid environment. Data was analyzed using a repeated measure model where repeated measures were hourly tympanic and tail temperatures and their difference for individual steers during the day of the experiment. There was a significant breed effect (P=0.01), hour (P<0.0001) and breed by hour interaction (P<0.0001) for the tympanic temperature. Brahman steers, which are known to have superior thermotolerance, maintained a lower body temperature than the Angus steers during the afternoon under grazing conditions. In the Brahman steers there was only a minimal increase in the body temperature throughout the day, an evidence of the thermotolerance ability of the breed. In the Angus steers, which experienced an increase in their body temperature from hour to hour with a peak around 1600 hour; there was a significant difference between the tympanic and tail temperature during the times when the body temperature as measured by the tympanic recordings was the highest (1300 to 1700 hour). Our results indicate that the tympanic temperature can be used to accurately and continuously monitor core body temperature in a natural environment for up to several days and without disturbing the animal.


Author(s):  
Rajnandini Singha ◽  
Amazing Grace Siangshai ◽  
Jashlyn Lijo

Hypothermia, described as a core body temperature of < 95%, is associated with ECG alteration abnormalities. Sinus bradycardia occurs when the body temperature drops below 90°F, and is correlated with gradual prolongation of the PR interval, QRS complex, QT interval. It can progress to ventricular and atrial fibrillation at a temperature reaching 89°F, which can lead to left ventricular dysfunction. Hypothermia is connected to the osborn waves, which at the end of the QRS complex consist of additional deflection. The inferior and lateral precordial leads are seen by Osborn waves, also known as J waves, Camel hump waves and hypothermic waves. As the body temperature decreases, it becomes more pronounced and a gradual expansion of the QRS complex raises the likelihood of ventricular fibrillation causing ventricle dysfunction.


2017 ◽  
Vol 60 (3) ◽  
pp. 19-25
Author(s):  
Sławomir Kujawski ◽  
Joanna Słomko ◽  
Monika Zawadka-Kunikowska ◽  
Mariusz Kozakiewicz ◽  
Jacek J. Klawe ◽  
...  

Abstract Changes observed in the core body temperature of divers are the result of a multifaceted response from the body to the change of the external environment. In response to repeated activities, there may be a chronic, physiological adaptation of the body’s response system. This is observed in the physiology of experienced divers while diving. The purpose of this study is to determine the immediate and delayed effects of hyperbaric exposure on core temperature, as well as its circadian changes in a group of three experienced divers. During compression at 30 and 60 meters, deep body temperature values tended to increase. Subsequently, deep body temperature values showed a tendency to decrease during decompression. All differences in core temperature values obtained by the group of divers at individual time points in this study were not statistically significant.


2003 ◽  
Vol 51 (6) ◽  
pp. 603 ◽  
Author(s):  
M. P. Ikonomopoulou ◽  
R. W. Rose

We investigated the metabolic rate, thermoneutral zone and thermal conductance of the eastern barred bandicoot in Tasmania. Five adult eastern barred bandicoots (two males, three non-reproductive females) were tested at temperatures of 3, 10, 15, 20, 25, 30, 35 and 40°C. The thermoneutral zone was calculated from oxygen consumption and body temperature, measured during the daytime: their normal resting phase. It was found that the thermoneutral zone lies between 25°C and 30°C, with a minimum metabolic rate of 0.51 mL g–1 h–1 and body temperature of 35.8°C. At cooler ambient temperatures (3–20°C) the body temperature decreased to approximately 34.0°C while the metabolic rate increased from 0.7 to 1.3 mL g–1�h–1. At high temperatures (35°C and 40°C) both body temperature (36.9–38.7°C) and metabolic rate (1.0–1.5 mL g–1 h–1) rose. Thermal conductance was low below an ambient temperature of 30°C but increased significantly at higher temperatures. The low thermal conductance (due, in part, to good insulation, a reduced body temperature at lower ambient temperatures, combined with a relatively high metabolic rate) suggests that this species is well adapted to cooler environments but it could not thermoregulate easily at temperatures above 30°C.


2010 ◽  
Vol 299 (6) ◽  
pp. R1478-R1488 ◽  
Author(s):  
Marshall Hampton ◽  
Bethany T. Nelson ◽  
Matthew T. Andrews

Small hibernating mammals show regular oscillations in their heart rate and body temperature throughout the winter. Long periods of torpor are abruptly interrupted by arousals with heart rates that rapidly increase from 5 beats/min to over 400 beats/min and body temperatures that increase by ∼30°C only to drop back into the hypothermic torpid state within hours. Surgically implanted transmitters were used to obtain high-resolution electrocardiogram and body temperature data from hibernating thirteen-lined ground squirrels ( Spermophilus tridecemlineatus ). These data were used to construct a model of the circulatory system to gain greater understanding of these rapid and extreme changes in physiology. Our model provides estimates of metabolic rates during the torpor-arousal cycles in different model compartments that would be difficult to measure directly. In the compartment that models the more metabolically active tissues and organs (heart, brain, liver, and brown adipose tissue) the peak metabolic rate occurs at a core body temperature of 19°C approximately midway through an arousal. The peak metabolic rate of the active tissues is nine times the normothermic rate after the arousal is complete. For the overall metabolic rate in all tissues, the peak-to-resting ratio is five. This value is high for a rodent, which provides evidence for the hypothesis that the arousal from torpor is limited by the capabilities of the cardiovascular system.


Author(s):  
Swarup A. Zachariah ◽  
Anup K. Paul ◽  
Rupak K. Banerjee ◽  
Liang Zhu

Predicting thermal responses of the human body accurately during different exercise conditions is of increasing importance. Computing changes in the core body temperature (T c) during exercise require detailed modeling of both the body tissue temperature and the time-dependent blood temperature. Predicting changes in T c is challenging because the model needs to respond effectively to the changes in perfusion or sweating. Our study was to demonstrate the ability of a recently developed whole body heat transfer model. It simulates the tissue-blood interaction to predict the thermal response of the human body under different exercise intensities. The cases simulated were of a human being walking on a treadmill at 0.9, 1.2 and 1.8 m/s for 30 minutes. It was shown that T c was effectively regulated within 0.17 °C of the steady state value of 37.23 °C for the three cases by means of adjusting the cardiac output; varying between 15 to 25 liters per minute.


2002 ◽  
Vol 227 (6) ◽  
pp. 382-388 ◽  
Author(s):  
Fernando Catalina ◽  
Leon Milewich ◽  
William Frawley ◽  
Vinay Kumar ◽  
Michael Bennett

Dietary dehydroepiandrosterone (DHEA) reduces food intake in mice, and this response is under genetic control. Moreover, both food restriction and DHEA can prevent or ameliorate certain diseases and mediate other biological effects. Mice fed DHEA (0.45% w/w of food) and mice pair-fed to these mice (food restricted) for 8 weeks were tested for changes in body temperature. DHEA was more efficient than food restriction alone in causing hypothermia. DHEA injected intraperitoneally also induced hypothermia that reached a nadir at 1 to 2 hr, and slowly recovered by 20 to 24 hr. This effect was dose dependent (0.5–50 mg). Each mouse strain tested (four) was susceptible to this effect, suggesting that the genetics differ for induction of hypophagia and induction of hypothermia. Because serotonin and dopamine can regulate (decrease) body temperature, we treated mice with haloperidol (dopamine receptor antagonist), 5,7-dihydroxytryptamine (serotonin production inhibitor), or ritanserin (serotonin receptor antagonist) prior to injection of DHEA. All of these agents increased rather than decreased the hypothermic effects of DHEA. DHEA metabolites that are proximate (5-androstene-3β, 17β-diol and androstenedione) or further downstream (estradiol-17β) were much less effective than DHEA in inducing hypothermia. However, the DHEA analog, 16α-chloroepiandrosterone, was as active as DHEA. Thus, DHEA administered parentally seems to act directly on temperature-regulating sites in the body. These results suggest that DHEA induces hypothermia independent of its ability to cause food restriction, to affect serotonin or dopamine functions, or to act via its downstream steroid metabolites.


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