Continuous radio telemetry of hypothalamic temperatures from unrestrained animals

1965 ◽  
Vol 20 (2) ◽  
pp. 321-325 ◽  
Author(s):  
Robert O. Rawson ◽  
Jan A. J. Stolwijk ◽  
Hans Graichen ◽  
Robert Abrams
Keyword(s):  
Motor Activity ◽  
Radio Telemetry ◽  
Temperature Cycle ◽  
Body Temperatures ◽  
Night Temperature ◽  
Hypothalamic Temperature ◽  
Temperature Variations ◽  
Free Running ◽  
Hot Environments

A system of radio telemetry has been designed which continuously records body temperatures of unrestrained animals with a resolution of 0.05 C over transmission distances of 100ˑ1,000 ft, permitting observations on free-running animals for indefinite periods of time. Continuous 24-hr recordings were made of hypothalamic temperatures telemetered from cold-acclimatized and unacclimatized dogs living in cold, neutral, and hot environments. During night hours, dogs usually exhibited a decrease in hypothalamic temperature of 0.5ˑ.0 C below daylight levels. Superimposed on the day-night temperature cycle are marked fluctuations of 0.1ˑ0.5 C at a rate of 0.1 C/min. These variations are associated with the level of motor activity, arousal, and with periods of dozing. Shivering in the cold is exhibited even though hypothalamic temperature may be elevated above a level at which no shivering occurs in a neutral environment. spontaneous hypothalamic temperature variations; cold-acclimatized dogs; day-night temperature cycle Submitted on June 3, 1964

Diurnal body temperature variations and hibernation in the birchmouse, Sicista betulina

1959 ◽  
Vol 196 (6) ◽  
pp. 1200-1204 ◽  
Author(s):  
Kjell Johansen ◽  
John Krog
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Respiratory Rate ◽  
Maximal Activity ◽  
Temperature Cycle ◽  
Body Temperatures ◽  
Temperature Variations ◽  
Ambient Temperatures ◽  
The Awakening ◽  
Compensatory Increase

Body temperatures, oxygen consumption and electrocardiograms were recorded in the birchmouse. The diurnal body temperature cycle ranged from 5° to 18°C during a regular 24-hour sequence. The highest body temperatures (37–38°C) are present around midnight, coinciding with the time of maximal activity. Body temperatures and oxygen consumption were studied at various ambient temperatures. With decreasing temperature the oxygen consumption commonly followed two successive patterns: first, a period of compensatory increase after which body temperature and oxygen consumption decreased; the compensation lasted from 5 minutes to 4 hours. At low ambient temperatures the animals went into a state of dormancy similar to seasonal hibernation in other mammals. The reduction in heart and respiratory rate as well as in oxygen consumption and body temperature confirmed those values reported earlier. Arousal from hibernation in the birchmouse is unique in the great speed of reaction with which the awakening takes place. Body temperature may increase as much as 1°C/min. and, within a period of 30 minutes, the oxygen consumption may increase 25 times.

scholarly journals Body Temperatures in Some Australian Mammals II.Peramelidae

1962 ◽  
Vol 15 (2) ◽  
pp. 386 ◽  
Author(s):  
PR Morrison
Keyword(s):  
Body Temperature ◽  
Ambient Temperature ◽  
Active Phase ◽  
Temperature Measurements ◽  
Temperature Cycle ◽  
Body Temperatures ◽  
Ambient Temperatures ◽  
Diurnal Temperature

Body temperature measurements on the short-nosed bandicoot (Thylacis obeaulus) have shown a nocturnal cycle with a range of 1� 2�C and a short active phase at 2200-0400 hr. The bilby or rabbit bandicoot (Macrotis lagoti8) had a sharply defined temperature cycle, with a range of almost 3�C after several months of captivity, during which the day-time resting temperature was progressively lowered from 36� 4 to 34� 2�C. Forced activity raised the diurnal temperature substantially but not to the nocturnal level. Forced activity did not raise the nocturnal level which was similar in the two species (37' O�C). Both species could regulate effectively at an ambient temperature of 5�C, but only Thylaci8 showed regulation at ambient temperatures of between 30 and 40�C.

Experimental Investigation on Aerosol-Particle Sustaining Characteristics of a Porous-Walled Tube

2018 ◽  
Vol 765 ◽  
pp. 131-135
Author(s):  
Kyung Won Kim ◽  
Brandon Y. Boeur ◽  
Sin Jae Hyun ◽  
Cheol Woo Park
Keyword(s):  
Aerosol Particle ◽  
Tube Wall ◽  
Porous Wall ◽  
Working Fluid ◽  
Particle Sizes ◽  
Tube Model ◽  
Body Temperatures ◽  
Temperature Variations ◽  
Significance Level ◽  
Wall Condition

In the present study, we experimentally investigated the aerosol-particle sustaining features of a porous-walled rubber foam tube model according to outlet humidity and temperature variations. An oleic acid aerosol is used as the inlet working fluid and the embedded particle diameters are in the range of 6–10 μm. To analyze particle size distribution, a wide-ranging particle spectrometer is employed, and particle sizes are measured at the inlet and outlet of the tube. Variance analysis is performed to evaluate the significance level of various tube-wall conditions, including dry and moist aerosol conditions at room and body temperatures. For the cases of larger particle sizes, the sustaining rates are increased when the porous wall condition is moist and at body temperature.

Sweating and body temperatures following abrupt changes in environmental temperature

1962 ◽  
Vol 17 (1) ◽  
pp. 103-106 ◽  
Author(s):  
H. S. Belding ◽  
B. A. Hertig
Keyword(s):  
Skin Temperature ◽  
Environmental Temperature ◽  
Sweat Rate ◽  
Human Subjects ◽  
Body Temperatures ◽  
Hypothalamic Temperature ◽  
Abrupt Changes ◽  
Consistent Change ◽  
Different Levels ◽  
Skin Receptors

Human subjects were transferred between environments imposing different levels of heat stress. Analyses of measurements obtained after a reasonably steady state had been achieved in each of several environments revealed equally good correlation between a) sweat rate and ear temperature (tympanic membrane), and b) sweat rate and calculated deep skin temperature (hypothetical). The correlations are consistent with adjustment of sweating in response to either hypothalamic temperature or temperature of skin receptors or some combination of the two. However, during the first 20 min after transfer, changes in sweat rate and skin temperature occurred together and in the same direction, but were not accompanied by any consistent change in ear temperature. Thus, to the extent that ear temperature represents hypothalamic temperature, an hypothesis of control of sweating based on hypothalamic temperature alone is not tenable. Alternative physiological explanations are given for data developed elsewhere and used in support of an hypothesis of sweat control solely from the hypothalamus. Submitted on August 14, 1961

Zur Beziehung zwischen Phasenlage und Spontanfrequenz bei der endogenen Tagesperiodik

1963 ◽  
Vol 18 (2) ◽  
pp. 154-157 ◽  
Author(s):  
Klaus Hoffmann
Keyword(s):  
Phase Angle ◽  
Diurnal Rhythm ◽  
Activity Rhythm ◽  
Sustained Oscillation ◽  
Temperature Cycle ◽  
Biological Processes ◽  
Experimental Demonstration ◽  
Free Running ◽  
Spontaneous Frequency ◽  
Free Running Period

The mechanism underlying the endogenous diurnal periodicity of biological processes can be considered a self-sustained oscillation, which can be entrained to an external cycle. In such oscillations the phase-angle of the entrained cycle depends upon the spontaneous frequency (free-running period) of the oscillator.The activity rhythm of lizards kept in constant light, and in a sinusoidal 24-hour temperature cycle, showed entrainment to this cycle. The phase of the entrained rhythm depended on the spontaneous frequency which was expressed in constant conditions occurring immediately before or after the exposure to the extraneous cycle. This is the first experimental demonstration showing the dependence of phase on the free-running period in an endogenous diurnal rhythm.

Limited behavioural thermoregulation by adult upriver-migrating sockeye salmon (Oncorhynchus nerka) in the Lower Fraser River, British Columbia

2009 ◽  
Vol 87 (6) ◽  
pp. 480-490 ◽  
Author(s):  
M. R. Donaldson ◽  
S. J. Cooke ◽  
D. A. Patterson ◽  
S. G. Hinch ◽  
D. Robichaud ◽  
...  
Keyword(s):  
British Columbia ◽  
Sockeye Salmon ◽  
Radio Telemetry ◽  
Oncorhynchus Nerka ◽  
Migration Route ◽  
Fraser River ◽  
Body Temperatures ◽  
Study Region ◽  
Ambient Temperatures ◽  
And Migration

The objective of this study was to combine radio telemetry with individual thermal loggers to assess the extent to which adult migrating sockeye salmon ( Oncorhynchus nerka (Walbaum in Artedi, 1792)) behaviourally thermoregulate during their migration through the Fraser River mainstem, British Columbia. The Fraser mainstem represents a region of the migration route that contains some of the highest mean temperatures encountered by sockeye salmon during their life history. We found that throughout the study area, individual sockeye salmon body temperatures occasionally deviated from ambient temperatures (ΔT), yet individuals maintained a ΔT of –1 °C or cooler for only 5% of their migration through the study region. There were moderate mean deviations of ΔT in two segments that are known to contain thermally stratified waters. In one of the study segments with the greatest ΔT, mean body temperatures decreased as river temperatures increased and ΔT became increasingly positive with higher river discharge rates, but these relationships were not observed in any of the other study segments. No relationship existed between ΔT and migration rate. While periodic associations with cool water were evident, mean body temperatures were not significantly different than mean river temperatures throughout the lower Fraser mainstem. This finding raises further conservation concerns for vulnerable Fraser River sockeye stocks that are predicted to encounter increasing peak summer river temperatures in the coming decades.

Motor activity correlates negatively with free-running period, while positively with serotonin contents in SCN in free-running rats

1991 ◽  
Vol 49 (4) ◽  
pp. 779-786 ◽  
Author(s):  
Toshiki Shioiri ◽  
Kiyohisa Takahashi ◽  
Yamada Naoto ◽  
Saburo Takahashi
Keyword(s):  
Motor Activity ◽  
Free Running ◽  
Free Running Period

scholarly journals An automatic system for determining the effects of temperature on the hysteresis curves of ion-selective electrodes

1997 ◽  
Vol 19 (2) ◽  
pp. 39-44 ◽  
Author(s):  
Júlia M. C. S. Magalhães ◽  
Adélio A. S. C. Machado
Keyword(s):  
Computer Program ◽  
Automatic System ◽  
Water Bath ◽  
Effect Of Temperature ◽  
Temperature Cycle ◽  
Ion Selective Electrodes ◽  
Temperature Stabilization ◽  
Temperature Variations ◽  
Hysteresis Curves ◽  
Effects Of Temperature

This paper describes an automatic system which measures the effect of temperature variations on the response of ion-selective electrodes (hysteresis curves). The system is managed by a computer program which plots hysteresis curves following a pre-established temperature cycle, from setting and controlling the temperature of the water-bath, to acquiring the response potentials of up to five electrodes after temperature stabilization.

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