scholarly journals Trapped in the darkness of the night: thermal and energetic constraints of daylight flight in bats

2011 ◽  
Vol 278 (1716) ◽  
pp. 2311-2317 ◽  
Author(s):  
Christian C. Voigt ◽  
Daniel Lewanzik
Keyword(s):  
Body Temperature ◽  
Solar Radiation ◽  
Core Body Temperature ◽  
Short Wave ◽  
Relative Energy ◽  
Night Time ◽  
Fruit Bat ◽  
Flight Costs ◽  
Risk Of Predation ◽  
The Hours

Bats are one of the most successful mammalian groups, even though their foraging activities are restricted to the hours of twilight and night-time. Some studies suggested that bats became nocturnal because of overheating when flying in daylight. This is because—in contrast to feathered wings of birds—dark and naked wing membranes of bats efficiently absorb short-wave solar radiation. We hypothesized that bats face elevated flight costs during daylight flights, since we expected them to alter wing-beat kinematics to reduce heat load by solar radiation. To test this assumption, we measured metabolic rate and body temperature during short flights in the tropical short-tailed fruit bat Carollia perspicillata at night and during the day. Core body temperature of flying bats differed by no more than 2°C between night and daytime flights, whereas mass-specific CO 2 production rates were higher by 15 per cent during daytime. We conclude that increased flight costs only render diurnal bat flights profitable when the relative energy gain during daytime is high and risk of predation is low. Ancestral bats possibly have evolved dark-skinned wing membranes to reduce nocturnal predation, but a low degree of reflectance of wing membranes made them also prone to overheating and elevated energy costs during daylight flights. In consequence, bats may have become trapped in the darkness of the night once dark-skinned wing membranes had evolved.

Efficacy Comparison of Korean Ginseng and American Ginseng on Body Temperature and Metabolic Parameters

2014 ◽  
Vol 42 (01) ◽  
pp. 173-187 ◽  
Author(s):  
Eun-Young Park ◽  
Mi-Hwi Kim ◽  
Eung-Hwi Kim ◽  
Eun-Kyu Lee ◽  
In-Sun Park ◽  
...  
Keyword(s):  
Food Intake ◽  
Body Temperature ◽  
Core Body Temperature ◽  
Serum Levels ◽  
American Ginseng ◽  
Metabolic Parameters ◽  
High Dose ◽  
Night Time ◽  
Related Factors ◽  
Korean Ginseng

Ginseng has beneficial effects in cancer, diabetes and aging. There are two main varieties of ginseng: Panax ginseng (Korean ginseng) and Panax quinquefolius (American ginseng). There are anecdotal reports that American ginseng helps reduce body temperature, whereas Korean ginseng improves blood circulation and increases body temperature; however, their respective effects on body temperature and metabolic parameters have not been studied. We investigated body temperature and metabolic parameters in mice using a metabolic cage. After administering ginseng extracts acutely (single dose of 1000 mg/kg) or chronically (200 mg/kg/day for four weeks), core body temperature, food intake, oxygen consumption and activity were measured, as well as serum levels of pyrogen-related factors and mRNA expression of metabolic genes. Acute treatment with American ginseng reduced body temperature compared with PBS-treated mice during the night; however, there was no significant effect of ginseng treatment on body temperature after four weeks of treatment. VO 2, VCO 2, food intake, activity and energy expenditure were unchanged after both acute and chronic ginseng treatment compared with PBS treatment. In acutely treated mice, serum thyroxin levels were reduced by red and American ginseng, and the serum prostaglandin E2 level was reduced by American ginseng. In chronically treated mice, red and white ginseng reduced thyroxin levels. We conclude that Korean ginseng does not stimulate metabolism in mice, whereas a high dose of American ginseng may reduce night-time body temperature and pyrogen-related factors.

Effect of wind and solar radiation on metabolic heat production in a small desert rodent, Spermophilus tereticaudus

2000 ◽  
Vol 203 (5) ◽  
pp. 879-888 ◽  
Author(s):  
K.M. Wooden ◽  
G.E. Walsberg
Keyword(s):  
Wind Speed ◽  
Body Temperature ◽  
Solar Radiation ◽  
Heat Production ◽  
Tissue Level ◽  
Short Wave ◽  
Metabolic Heat Production ◽  
Metabolic Heat ◽  
Simulated Solar Radiation ◽  
Solar Radiation Exposure

To understand better how complex interactions between environmental variables affect the energy balance of small diurnal animals, we studied the effects of the absence and presence of 950 W m(−)(2) simulated solar radiation combined with wind speeds ranging from 0. 25 to 1.00 m s(−)(1) on the metabolic rate and body temperature of the round-tailed ground squirrel Spermophilus tereticaudus. As wind speed increased from 0.25 to 1.00 m s(−)(1), metabolic heat production increased by 0.94 W in the absence of solar radiation and by 0.98 W in the presence of 950 W m(−)(2) simulated solar radiation. Exposure to simulated solar radiation reduced metabolic heat production by 0.68 W at a wind speed of 0.25 m s(−)(1), by 0.64 W at 0.50 m s(−)(1) and by 0.64 W at 1.00 m s(−)(1). Body temperature was significantly affected by environmental conditions, ranging from 32. 5 degrees C at a wind speed of 1.0 m s(−)(1) and no irradiance to 35. 6 degrees C at a wind speed of 0.50 m s(−)(1) with 950 W m(−)(2)short-wave irradiance. In addition, several unusual findings resulted from this study. The coat of S. tereticaudus is very sparse, and the observed heat transfer of 5.68+/−0.37 W m(−)(2) degrees C(−)(1) (mean +/− s.e.m., N=11) is much higher than expected from either allometric equations or comparative studies with other rodents of similar mass. Solar heat gain was remarkably low, equalling only 10 % of intercepted radiation and suggesting a remarkably high regional thermal resistance at the tissue level. Animals remained normally active and alert at body temperatures as low as 32.5 degrees C. These findings suggest a unique combination of adaptations that allow S. tereticaudus to exploit a harsh desert environment.

Core body temperature changes after sauna exposition in healthy subjects

2012 ◽  
Vol 26 (2) ◽  
Author(s):  
Joanna Pawlak ◽  
Paweł Zalewski ◽  
Jacek J. Klawe ◽  
Monika Zawadka ◽  
Anna Bitner ◽  
...  
Keyword(s):  
Body Temperature ◽  
Healthy Subjects ◽  
Core Body Temperature ◽  
Temperature Changes ◽  
Core Body

scholarly journals Pathophysiology of Fever and Application of Infrared Thermography (IRT) in the Detection of Sick Domestic Animals: Recent Advances

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 ◽  
...  
Keyword(s):  
Body Temperature ◽  
Infrared Thermography ◽  
Core Body Temperature ◽  
The Body ◽  
Farm Animals ◽  
Economic Losses ◽  
Febrile Response ◽  
Temperature Range ◽  
Stable Temperature ◽  
Core Body

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.

scholarly journals A novel mouse model of heatstroke accounting for ambient temperature and relative humidity

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Kazuyuki Miyamoto ◽  
Keisuke Suzuki ◽  
Hirokazu Ohtaki ◽  
Motoyasu Nakamura ◽  
Hiroki Yamaga ◽  
...  
Keyword(s):  
Gene Expression ◽  
Body Temperature ◽  
Relative Humidity ◽  
Ambient Temperature ◽  
Core Body Temperature ◽  
Heat Exposure ◽  
Organ Damage ◽  
Core Body ◽  
The Impact ◽  
Treatment Water

Abstract Background Heatstroke is associated with exposure to high ambient temperature (AT) and relative humidity (RH), and an increased risk of organ damage or death. Previously proposed animal models of heatstroke disregard the impact of RH. Therefore, we aimed to establish and validate an animal model of heatstroke considering RH. To validate our model, we also examined the effect of hydration and investigated gene expression of cotransporter proteins in the intestinal membranes after heat exposure. Methods Mildly dehydrated adult male C57/BL6J mice were subjected to three AT conditions (37 °C, 41 °C, or 43 °C) at RH > 99% and monitored with WetBulb globe temperature (WBGT) for 1 h. The survival rate, body weight, core body temperature, blood parameters, and histologically confirmed tissue damage were evaluated to establish a mouse heatstroke model. Then, the mice received no treatment, water, or oral rehydration solution (ORS) before and after heat exposure; subsequent organ damage was compared using our model. Thereafter, we investigated cotransporter protein gene expressions in the intestinal membranes of mice that received no treatment, water, or ORS. Results The survival rates of mice exposed to ATs of 37 °C, 41 °C, and 43 °C were 100%, 83.3%, and 0%, respectively. From this result, we excluded AT43. Mice in the AT 41 °C group appeared to be more dehydrated than those in the AT 37 °C group. WBGT in the AT 41 °C group was > 44 °C; core body temperature in this group reached 41.3 ± 0.08 °C during heat exposure and decreased to 34.0 ± 0.18 °C, returning to baseline after 8 h which showed a biphasic thermal dysregulation response. The AT 41 °C group presented with greater hepatic, renal, and musculoskeletal damage than did the other groups. The impact of ORS on recovery was greater than that of water or no treatment. The administration of ORS with heat exposure increased cotransporter gene expression in the intestines and reduced heatstroke-related damage. Conclusions We developed a novel mouse heatstroke model that considered AT and RH. We found that ORS administration improved inadequate circulation and reduced tissue injury by increasing cotransporter gene expression in the intestines.

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