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Sample records for body temperature rhythms

  1. Rhythms of mammalian body temperature can sustain peripheral circadian clocks.

    Science.gov (United States)

    Brown, Steven A; Zumbrunn, Gottlieb; Fleury-Olela, Fabienne; Preitner, Nicolas; Schibler, Ueli

    2002-09-17

    Low-amplitude temperature oscillations can entrain the phase of circadian rhythms in several unicellular and multicellular organisms, including Neurospora and Drosophila. Because mammalian body temperature is subject to circadian variations of 1 degrees C-4 degrees C, we wished to determine whether these temperature cycles could serve as a Zeitgeber for circadian gene expression in peripheral cell types. In RAT1 fibroblasts cultured in vitro, circadian gene expression could be established by a square wave temperature rhythm with a (Delta)T of 4 degrees C (12 hr 37 degrees C/12 hr 33 degrees C). To examine whether natural body temperature rhythms can also affect circadian gene expression, we first measured core body temperature cycles in the peritoneal cavities of mice by radiotelemetry. We then reproduced these rhythms with high precision in the liquid medium of cultured fibroblasts for several days by means of a homemade computer-driven incubator. While these "in vivo" temperature rhythms were incapable of establishing circadian gene expression de novo, they could maintain previously induced rhythms for multiple days; by contrast, the rhythms of control cells kept at constant temperature rapidly dampened. Moreover, circadian oscillations of environmental temperature could reentrain circadian clocks in the livers of mice, probably via the changes they imposed upon both body temperature and feeding behavior. Interestingly, these changes in ambient temperature did not affect the phase of the central circadian pacemaker in the suprachiasmatic nucleus (SCN) of the hypothalamus. We postulate that both endogenous and environmental temperature cycles can participate in the synchronization of peripheral clocks in mammals.

  2. Estimation of Circadian Body Temperature Rhythm Based on Heart Rate in Healthy, Ambulatory Subjects.

    Science.gov (United States)

    Sim, Soo Young; Joo, Kwang Min; Kim, Han Byul; Jang, Seungjin; Kim, Beomoh; Hong, Seungbum; Kim, Sungwan; Park, Kwang Suk

    2017-03-01

    Core body temperature is a reliable marker for circadian rhythm. As characteristics of the circadian body temperature rhythm change during diverse health problems, such as sleep disorder and depression, body temperature monitoring is often used in clinical diagnosis and treatment. However, the use of current thermometers in circadian rhythm monitoring is impractical in daily life. As heart rate is a physiological signal relevant to thermoregulation, we investigated the feasibility of heart rate monitoring in estimating circadian body temperature rhythm. Various heart rate parameters and core body temperature were simultaneously acquired in 21 healthy, ambulatory subjects during their routine life. The performance of regression analysis and the extended Kalman filter on daily body temperature and circadian indicator (mesor, amplitude, and acrophase) estimation were evaluated. For daily body temperature estimation, mean R-R interval (RRI), mean heart rate (MHR), or normalized MHR provided a mean root mean square error of approximately 0.40 °C in both techniques. The mesor estimation regression analysis showed better performance than the extended Kalman filter. However, the extended Kalman filter, combined with RRI or MHR, provided better accuracy in terms of amplitude and acrophase estimation. We suggest that this noninvasive and convenient method for estimating the circadian body temperature rhythm could reduce discomfort during body temperature monitoring in daily life. This, in turn, could facilitate more clinical studies based on circadian body temperature rhythm.

  3. Circadian rhythms of body temperature and locomotor activity in the antelope ground squirrel, Ammospermophilus leucurus.

    Science.gov (United States)

    Refinetti, Roberto; Kenagy, G J

    2018-02-01

    We studied circadian rhythms of body temperature and locomotor activity in antelope ground squirrels (Ammospermophilus leucurus) under laboratory conditions of a 12L:12D light-dark cycle and in constant darkness. Antelope ground squirrels are diurnally active and, exceptionally among ground squirrels and other closely related members of the squirrel family in general, they do not hibernate. Daily oscillations in body temperature consisted of a rise in temperature during the daytime activity phase of the circadian cycle and a decrease in temperature during the nighttime rest phase. The body temperature rhythms were robust (71% of maximal strength) with a daily range of oscillation of 4.6°C, a daytime mean of 38.7°C, and a nighttime mean of 34.1°C (24-h overall mean 36.4°C). The body temperature rhythm persisted in continuous darkness with a free-running period of 24.2h. This pattern is similar to that of hibernating species of ground squirrels but with a wave form more similar to that of non-hibernating rodents. Daily oscillations in body temperature were correlated with individual bouts of activity, but daytime temperatures were higher than nighttime temperatures even when comparing short episodes of nocturnal activity that were as intense as diurnal activity. This suggests that although muscular thermogenesis associated with locomotor activity can modify the level of body temperature, the circadian rhythm of body temperature is not simply a consequence of the circadian rhythm of activity. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Disturbances in melatonin, cortisol and core body temperature rhythms after major surgery.

    Science.gov (United States)

    Gögenur, Ismail; Ocak, Ubbat; Altunpinar, Omer; Middleton, Benita; Skene, Debra J; Rosenberg, Jacob

    2007-02-01

    It has been suggested that circadian rhythm disturbances are present after major surgery and that this may play a role in the development of postoperative sleep disturbances, fatigue, cognitive dysfunction and cardiovascular morbidity. The objective of this study was to examine the profile of melatonin, cortisol and core body temperature rhythms before and after major surgery. Blood samples (melatonin and cortisol) and core body temperature readings were collected every hour in the 24-h period prior to surgery and the 48 h after surgery from 11 patients undergoing major abdominal surgery. All patients had private rooms. Light exposure was controlled and monitored. Phase markers [50% dim light melatonin onset (DLMO 50%) and offset (DLMOff 50%), cortisol and core body temperature acrophase] for the three circadian rhythm profiles were calculated before and after surgery. The correlation between the melatonin rhythm and time of surgery, duration of surgery and opioid use was examined. A median delay in the onset of melatonin was seen on the first postoperative day [median DLMO 50% 22:46 hours (range: 21:15-01:08 hours) on the preoperative day compared with 23:54 hours (range: 19:09-02:46 hours) on the first postoperative day; P melatonin onset (r = 0.67, P melatonin immediately after surgery, with a subsequent significant increase in maximum melatonin values on the second postoperative night. A median delay of up to 4 h was seen in the timing of the peak of the temperature rhythm on the second postoperative day. Both cortisol secretion and core body temperature were increased after surgery and did not return to preoperative values in the 48 h of the postoperative study period. No significant correlation between opioid dose and the basal or maximum melatonin levels or the time of melatonin onset was found. We found disturbances in three circadian markers after major surgery. The clinical consequences of postoperative circadian disturbances should be investigated

  5. Acute dim light at night increases body mass, alters metabolism, and shifts core body temperature circadian rhythms.

    Science.gov (United States)

    Borniger, Jeremy C; Maurya, Santosh K; Periasamy, Muthu; Nelson, Randy J

    2014-10-01

    The circadian system is primarily entrained by the ambient light environment and is fundamentally linked to metabolism. Mounting evidence suggests a causal relationship among aberrant light exposure, shift work, and metabolic disease. Previous research has demonstrated deleterious metabolic phenotypes elicited by chronic (>4 weeks) exposure to dim light at night (DLAN) (∼ 5 lux). However, the metabolic effects of short-term (body mass, alter whole body metabolism, and display altered body temperature (Tb) and activity rhythms compared to mice maintained in dark nights. Our data largely support these predictions; DLAN mice gained significantly more mass, reduced whole body energy expenditure, increased carbohydrate over fat oxidation, and altered temperature circadian rhythms. Importantly, these alterations occurred despite similar activity locomotor levels (and rhythms) and total food intake between groups. Peripheral clocks are potently entrained by body temperature rhythms, and the deregulation of body temperature we observed may contribute to metabolic problems due to "internal desynchrony" between the central circadian oscillator and temperature sensitive peripheral clocks. We conclude that even relatively short-term exposure to low levels of nighttime light can influence metabolism to increase mass gain.

  6. Free-running circadian rhythms of muscle strength, reaction time, and body temperature in totally blind people

    OpenAIRE

    Squarcini, Camila Fabiana Rossi; Pires, Maria Laura Nogueira [UNESP; Lopes, Cleide; Benedito-silva, Ana AmÉlia; Esteves, Andrea Maculano; Cornelissen-guillaume, Germaine; Matarazzo, Carolina; Garcia, Danilo; Silva, Maria Stella Peccin; Tufik, Sergio; Mello, Marco TÚlio

    2013-01-01

    Light is the major synchronizer of circadian rhythms. In the absence of light, as for totally blind people, some variables, such as body temperature, have an endogenous period that is longer than 24 h and tend to be free running. However, the circadian rhythm of muscle strength and reaction time in totally blind people has not been defined in the literature. The objective of this study was to determine the period of the endogenous circadian rhythm of the isometric and isokinetic contraction s...

  7. Markets, Bodies, Rhythms

    DEFF Research Database (Denmark)

    Borch, Christian; Bondo Hansen, Kristian; Lange, Ann-Christina

    2015-01-01

    This article explores the relationship between bodily rhythms and market rhythms in two distinctly different financial market configurations, namely the open-outcry pit (prevalent especially in the early 20th century) and present-day high-frequency trading. Drawing on Henri Lefebvre's rhythmanaly......This article explores the relationship between bodily rhythms and market rhythms in two distinctly different financial market configurations, namely the open-outcry pit (prevalent especially in the early 20th century) and present-day high-frequency trading. Drawing on Henri Lefebvre...... of financial markets, it also suggests that high-frequency trading in particular might produce new types of market rhythms that, contra Lefebvre, do not revolve around traders' bodies....

  8. Simulated body temperature rhythms reveal the phase-shifting behavior and plasticity of mammalian circadian oscillators

    Science.gov (United States)

    Saini, Camille; Morf, Jörg; Stratmann, Markus; Gos, Pascal; Schibler, Ueli

    2012-01-01

    The circadian pacemaker in the suprachiasmatic nuclei (SCN) of the hypothalamus maintains phase coherence in peripheral cells through metabolic, neuronal, and humoral signaling pathways. Here, we investigated the role of daily body temperature fluctuations as possible systemic cues in the resetting of peripheral oscillators. Using precise temperature devices in conjunction with real-time monitoring of the bioluminescence produced by circadian luciferase reporter genes, we showed that simulated body temperature cycles of mice and even humans, with daily temperature differences of only 3°C and 1°C, respectively, could gradually synchronize circadian gene expression in cultured fibroblasts. The time required for establishing the new steady-state phase depended on the reporter gene, but after a few days, the expression of each gene oscillated with a precise phase relative to that of the temperature cycles. Smooth temperature oscillations with a very small amplitude could synchronize fibroblast clocks over a wide temperature range, and such temperature rhythms were also capable of entraining gene expression cycles to periods significantly longer or shorter than 24 h. As revealed by genetic loss-of-function experiments, heat-shock factor 1 (HSF1), but not HSF2, was required for the efficient synchronization of fibroblast oscillators to simulated body temperature cycles. PMID:22379191

  9. Simulated body temperature rhythms reveal the phase-shifting behavior and plasticity of mammalian circadian oscillators.

    Science.gov (United States)

    Saini, Camille; Morf, Jörg; Stratmann, Markus; Gos, Pascal; Schibler, Ueli

    2012-03-15

    The circadian pacemaker in the suprachiasmatic nuclei (SCN) of the hypothalamus maintains phase coherence in peripheral cells through metabolic, neuronal, and humoral signaling pathways. Here, we investigated the role of daily body temperature fluctuations as possible systemic cues in the resetting of peripheral oscillators. Using precise temperature devices in conjunction with real-time monitoring of the bioluminescence produced by circadian luciferase reporter genes, we showed that simulated body temperature cycles of mice and even humans, with daily temperature differences of only 3°C and 1°C, respectively, could gradually synchronize circadian gene expression in cultured fibroblasts. The time required for establishing the new steady-state phase depended on the reporter gene, but after a few days, the expression of each gene oscillated with a precise phase relative to that of the temperature cycles. Smooth temperature oscillations with a very small amplitude could synchronize fibroblast clocks over a wide temperature range, and such temperature rhythms were also capable of entraining gene expression cycles to periods significantly longer or shorter than 24 h. As revealed by genetic loss-of-function experiments, heat-shock factor 1 (HSF1), but not HSF2, was required for the efficient synchronization of fibroblast oscillators to simulated body temperature cycles.

  10. The circadian rhythm of core body temperature (Part I: The use of modern telemetry systems to monitor core body temperature variability

    Directory of Open Access Journals (Sweden)

    Słomko Joanna

    2016-06-01

    Full Text Available The best known daily rhythms in humans include: the sleep-wake rhythm, the circadian core body temperature variability, daily fluctuations in arterial blood pressure and heartbeat frequency, and daily changes in hormone secretion: e.g. melatonin, cortisol, growth hormone, prolactin. The core body temperature in humans has a characteristic sinusoidal course, with the maximum value occurring between 3:00-5:00 pm and the minimum between 3:00-5:00 am. Analysis of literature indicates that the obtained results concerning core body temperature are to a large extent influenced by the type of method applied in the measurement. Depending on test protocols, we may apply various methodologies to measuring core body temperature. One of the newest methods of measuring internal and external body temperature consists in the utilisation of remote temperature sensors transmitting the obtained value via a radio signal. The advantages of this method includes the ability to perform: continuous core temperature measurement, observe dynamic changes in core body temperature occurring in circadian rhythm and the repeatability and credibility of the obtained results, which is presented in numerous scientific reports.

  11. Effects of Resveratrol on Daily Rhythms of Locomotor Activity and Body Temperature in Young and Aged Grey Mouse Lemurs

    Directory of Open Access Journals (Sweden)

    Fabien Pifferi

    2013-01-01

    Full Text Available In several species, resveratrol, a polyphenolic compound, activates sirtuin proteins implicated in the regulation of energy balance and biological clock processes. To demonstrate the effect of resveratrol on clock function in an aged primate, young and aged mouse lemurs (Microcebus murinus were studied over a 4-week dietary supplementation with resveratrol. Spontaneous locomotor activity and daily variations in body temperature were continuously recorded. Reduction in locomotor activity onset and changes in body temperature rhythm in resveratrol-supplemented aged animals suggest an improved synchronisation on the light-dark cycle. Resveratrol could be a good candidate to restore the circadian rhythms in the elderly.

  12. Body temperature circadian rhythm variability corresponds to left ventricular systolic dysfunction in decompensated cardiomyopathic hamsters.

    Science.gov (United States)

    Ahmed, Amany; Gondi, Sreedevi; Cox, Casey; Zheng, Minjuan; Mohammed, Anwarullah; Stupin, Igor V; Wang, Suwei; Vela, Deborah; Brewer, Alan; Elayda, Macarthur A; Buja, L Maximilian; Ward Casscells, S; Wilson, James M

    2011-11-01

    A declining amplitude of body temperature circadian rhythm (BTCR) predicts decompensation or death in cardiomyopathic hamsters. We tested the hypothesis that changes in BTCR amplitude accompany significant changes in left ventricular (LV) size and function. Using intraperitoneal transmitters, we continuously monitored the temperature of 30 male BIO TO-2 Syrian dilated cardiomyopathic hamsters. Cosinor analysis was used to detect significant changes--defined as changes >1 standard deviation from the baseline amplitude for 3 consecutive days--in BTCR amplitude over each hamster's lifespan. The Student t-test was used to compare BTCR variability and LV size and function (as assessed by 2D echocardiography) between baseline and the time that BTCR amplitude declined. All hamsters received 10 mg/kg furosemide daily. At the time of BTCR amplitude decline, functional parameters had changed significantly (P < .0001) from baseline: ejection fraction (0.31 ± 0.09% vs. 0.52 ± 0.08%), LV end-systolic volume (0.11 ± 0.03 vs. 0.05 ± 0.02 cm(3)), and LV end-diastolic volume (0.16 ± 0.04 vs. 0.10 ± 0.03 cm(3)). In decompensated cardiomyopathic hamsters, a decline in BTCR amplitude was associated with progression of heart failure and cardiac decompensation. Variation in BTCR warrants further investigation because of its potential implications for the diagnosis and treatment of cardiovascular disorders. Published by Elsevier Inc.

  13. Body temperature variability (Part 1): a review of the history of body temperature and its variability due to site selection, biological rhythms, fitness, and aging.

    Science.gov (United States)

    Kelly, Greg

    2006-12-01

    Body temperature is a complex, non-linear data point, subject to many sources of internal and external variation. While these sources of variation significantly complicate interpretation of temperature data, disregarding knowledge in favor of oversimplifying complex issues would represent a significant departure from practicing evidence-based medicine. Part 1 of this review outlines the historical work of Wunderlich on temperature and the origins of the concept that a healthy normal temperature is 98.6 degrees F (37.0 degrees C). Wunderlich's findings and methodology are reviewed and his results are contrasted with findings from modern clinical thermometry. Endogenous sources of temperature variability, including variations caused by site of measurement, circadian, menstrual, and annual biological rhythms, fitness, and aging are discussed. Part 2 will review the effects of exogenous masking agents - external factors in the environment, diet, or lifestyle that can influence body temperature, as well as temperature findings in disease states.

  14. Remote long-term registrations of sleep-wake rhythms, core body temperature and activity in marmoset monkeys.

    Science.gov (United States)

    Hoffmann, Kerstin; Coolen, Alex; Schlumbohm, Christina; Meerlo, Peter; Fuchs, Eberhard

    2012-12-01

    Initial studies in the day active marmoset monkey (Callithrix jacchus) indicate that the sleep-wake cycle of these non-human primates resembles that of humans and therefore conceivably represent an appropriate model for human sleep. The methods currently employed for sleep studies in marmosets are limited. The objective of this study was to employ and validate the use of specific remote monitoring system technologies that enable accurate long-term recordings of sleep-wake rhythms and the closely related rhythms of core body temperature (CBT) and locomotor activity in unrestrained group-housed marmosets. Additionally, a pilot sleep deprivation (SD) study was performed to test the recording systems in an applied experimental setup. Our results show that marmosets typically exhibit a monophasic sleep pattern with cyclical alternations between NREM and REM sleep. CBT displays a pronounced daily rhythm and locomotor activity is primarily restricted to the light phase. SD caused an immediate increase in NREM sleep time and EEG slow-wave activity as well as a delayed REM sleep rebound that did not fully compensate for REM sleep that had been lost during SD. In conclusion, the combination of two innovative technical approaches allows for simultaneous measurements of CBT, sleep cycles and activity in multiple subjects. The employment of these systems represents a significant refinement in terms of animal welfare and will enable many future applications and longitudinal studies of circadian rhythms in marmosets. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Posttranscriptional mechanisms controlling diurnal gene expression cycles by body temperature rhythms.

    Science.gov (United States)

    Gotic, Ivana; Schibler, Ueli

    2017-10-03

    In mammals, body temperature oscillates in a daily fashion around a set point of 36°C-37°C. These fluctuations are controlled by the circadian master clock residing in the brain's suprachiasmatic nucleus and, despite their small amplitudes, contribute to the diurnal expression of genes throughout the organism. By focusing on the mechanisms underlying the temperature-dependent accumulation of the cold-inducible RNA-binding protein CIRBP - a factor involved in the tuning of amplitude and phase in circadian clocks of peripheral tissues - we have recently identified a novel mechanism governing temperature-dependent gene expression. This mechanism involves the differential spicing efficiency of primary RNA transcripts under different temperature conditions and thereby determines the fraction of Cirbp pre-mRNA processed into mature mRNA. A genome-wide transcriptome analysis revealed that this mechanism affects the output of hundreds of genes. Here we discuss our findings and future directions toward the identification of specific factors and parameters governing temperature-sensitive splicing efficacy.

  16. Cold exposure and/or fasting modulate the relationship between sleep and body temperature rhythms in mice.

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    Sato, Nobuo; Marui, Shuri; Ozaki, Makoto; Nagashima, Kei

    2015-10-01

    We assessed the relationship between core temperature (Tc) and sleep rhythms in mice, and examined the effects of ambient temperature and fasting. Tc, electroencephalograms (EEG), electromyograms (EMG), and spontaneous activity in male ICR mice (n=9) were measured by telemetry for 3 days under a 12:12h dark-light cycle. Mice were fed or fasted at an ambient temperature (Ta) of 27°C or 20°C for the final 30h of the experiment. The vigilance state was categorized into a wake state, rapid-eye movement (REM) sleep, and non-REM (NREM) sleep, and the total sleep time (TST) was assessed. Relationships between Tc and TST, NREM periods, and REM sleep were estimated using Pearson's correlation coefficient. During cold exposure, Tc decreased during the dark and light phases, and TST and the periods of NREM and REM sleep decreased during the dark phase. Throughout the fasting period, Tc also decreased during the dark and light phases. Furthermore, the decrease in Tc was augmented when fasting and cold were combined. TST and NREM sleep periods decreased in the light and dark phases, respectively, whereas REM sleep periods decreased in both phases. Negative linear correlations (r=-0.884 to -0.987) were observed between Tc and TST, NREM sleep periods, and REM sleep periods, except for Tc and REM sleep periods where fasting and cold conditions were combined. The correlations between sleep and Tc rhythms were well maintained during cold exposure and fasting. However, when cold and fasting were combined, REM sleep and Tc rhythms were desynchronized. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Rapid phase adjustment of melatonin and core body temperature rhythms following a 6-h advance of the light/dark cycle in the horse

    Directory of Open Access Journals (Sweden)

    Kennedy Erin L

    2007-08-01

    Full Text Available Abstract Background Rapid displacement across multiple time zones results in a conflict between the new cycle of light and dark and the previously entrained program of the internal circadian clock, a phenomenon known as jet lag. In humans, jet lag is often characterized by malaise, appetite loss, fatigue, disturbed sleep and performance deficit, the consequences of which are of particular concern to athletes hoping to perform optimally at an international destination. As a species renowned for its capacity for athletic performance, the consequences of jet lag are also relevant for the horse. However, the duration and severity of jet lag related circadian disruption is presently unknown in this species. We investigated the rates of re-entrainment of serum melatonin and core body temperature (BT rhythms following an abrupt 6-h phase advance of the LD cycle in the horse. Methods Six healthy, 2 yr old mares entrained to a 12 h light/12 h dark (LD 12:12 natural photoperiod were housed in a light-proofed barn under a lighting schedule that mimicked the external LD cycle. Following baseline sampling on Day 0, an advance shift of the LD cycle was accomplished by ending the subsequent dark period 6 h early. Blood sampling for serum melatonin analysis and BT readings were taken at 3-h intervals for 24 h on alternate days for 11 days. Disturbances to the subsequent melatonin and BT 24-h rhythms were assessed using repeated measures ANOVA and analysis of Cosine curve fitting parameters. Results We demonstrate that the equine melatonin rhythm re-entrains rapidly to a 6-h phase advance of an LD12:12 photocycle. The phase shift in melatonin was fully complete on the first day of the new schedule and rhythm phase and waveform were stable thereafter. In comparison, the advance in the BT rhythm was achieved by the third day, however BT rhythm waveform, especially its mesor, was altered for many days following the LD shift. Conclusion Aside from the temperature

  18. The validity, reliability, and utility of the iButton® for measurement of body temperature circadian rhythms in sleep/wake research.

    Science.gov (United States)

    Hasselberg, Michael J; McMahon, James; Parker, Kathy

    2013-01-01

    Changes in core body temperature due to heat transfer through the skin have a major influence on sleep regulation. Traditional measures of skin temperature are often complicated by extensive wiring and are not practical for use in normal living conditions. This review describes studies examining the reliability, validity and utility of the iButton®, a wireless peripheral thermometry device, in sleep/wake research. A review was conducted of English language literature on the iButton as a measure of circadian body temperature rhythms associated with the sleep/wake cycle. Seven studies of the iButtton as a measure of human body temperature were included. The iButton was found to be a reliable and valid measure of body temperature. Its application to human skin was shown to be comfortable and tolerable with no significant adverse reactions. Distal skin temperatures were negatively correlated with sleep/wake activity, and the temperature gradient between the distal and proximal skin (DPG) was identified as an accurate physiological correlate of sleep propensity. Methodological issues included site of data logger placement, temperature masking factors, and temperature data analysis. The iButton is an inexpensive, wireless data logger that can be used to obtain a valid measurement of human skin temperature. It is a practical alternative to traditional measures of circadian rhythms in sleep/wake research. Further research is needed to determine the utility of the iButton in vulnerable populations, including those with neurodegenerative disorders and memory impairment and pediatric populations. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Body temperature rhythm and control of the time of the best physical condition by performing physical labor.

    Science.gov (United States)

    Imafuku, Michio

    2016-01-01

    The initial examination of a male subject's body temperature revealed that it was highest during the evening. Based on this observation, I measured grasping power, calculation speed, performance time on a light sensory task and body temperature, all of which were highest or best during the evening. The time of this subject's best physical condition shifted from the evening to morning hours when the subject executed hard physical labor in the morning, and the shifted phase was maintained after the termination of the labor period.

  20. Circadian rhythm of temperature selection in a nocturnal lizard.

    Science.gov (United States)

    Refinetti, R; Susalka, S J

    1997-08-01

    We recorded body temperature and locomotor activity of Tokay geckos (Gekko gecko) with free access to a heat source under a 14:10 light-dark cycle and in constant darkness. Under the light-dark cycle, the lizards selected higher temperatures during the light phase, when locomotor activity was less intense. Rhythmicity in temperature selection was transiently disrupted but later resumed when the animals were placed in constant darkness. These results demonstrate the existence of a circadian rhythm of temperature selection in nocturnal ectotherms and extend previous findings of a temporal mismatch between the rhythms of locomotor activity and temperature selection in nocturnal rodents.

  1. Remote long-term registrations of sleep-wake rhythms, core body temperature and activity in marmoset monkeys

    OpenAIRE

    Hoffmann, Kerstin; Coolen, Alex; Schlumbohm, Christina; Meerlo, Peter; Fuchs, Eberhard

    2012-01-01

    Initial studies in the day active marmoset monkey (Callithrix jacchus) indicate that the sleep-wake cycle of these non-human primates resembles that of humans and therefore conceivably represent an appropriate model for human sleep. The methods currently employed for sleep studies in marmosets are limited. The objective of this study was to employ and validate the use of specific remote monitoring system technologies that enable accurate long-term recordings of sleep-wake rhythms and the clos...

  2. The timing of the human circadian clock is accurately represented by the core body temperature rhythm following phase shifts to a three-cycle light stimulus near the critical zone

    Science.gov (United States)

    Jewett, M. E.; Duffy, J. F.; Czeisler, C. A.

    2000-01-01

    A double-stimulus experiment was conducted to evaluate the phase of the underlying circadian clock following light-induced phase shifts of the human circadian system. Circadian phase was assayed by constant routine from the rhythm in core body temperature before and after a three-cycle bright-light stimulus applied near the estimated minimum of the core body temperature rhythm. An identical, consecutive three-cycle light stimulus was then applied, and phase was reassessed. Phase shifts to these consecutive stimuli were no different from those obtained in a previous study following light stimuli applied under steady-state conditions over a range of circadian phases similar to those at which the consecutive stimuli were applied. These data suggest that circadian phase shifts of the core body temperature rhythm in response to a three-cycle stimulus occur within 24 h following the end of the 3-day light stimulus and that this poststimulus temperature rhythm accurately reflects the timing of the underlying circadian clock.

  3. Impact of chronodisruption during primate pregnancy on the maternal and newborn temperature rhythms.

    Directory of Open Access Journals (Sweden)

    María Serón-Ferré

    Full Text Available Disruption of the maternal environment during pregnancy is a key contributor to offspring diseases that develop in adult life. To explore the impact of chronodisruption during pregnancy in primates, we exposed pregnant capuchin monkeys to constant light (eliminating the maternal melatonin rhythm from the last third of gestation to term. Maternal temperature and activity circadian rhythms were assessed as well as the newborn temperature rhythm. Additionally we studied the effect of daily maternal melatonin replacement during pregnancy on these rhythms. Ten pregnant capuchin monkeys were exposed to constant light from 60% of gestation to term. Five received a daily oral dose of melatonin (250 µg kg/body weight at 1800 h (LL+Mel and the other five a placebo (LL. Six additional pregnant females were maintained in a 14∶10 light:dark cycles and their newborns were used as controls (LD. Rhythms were recorded 96 h before delivery in the mother and at 4-6 days of age in the newborn. Exposure to constant light had no effect on the maternal body temperature rhythm however it delayed the acrophase of the activity rhythm. Neither rhythm was affected by melatonin replacement. In contrast, maternal exposure to constant light affected the newborn body temperature rhythm. This rhythm was entrained in control newborns whereas LL newborns showed a random distribution of the acrophases over 24-h. In addition, mean temperature was decreased (34.0±0.6 vs 36.1±0.2°C, in LL and control, respectively P<0.05. Maternal melatonin replacement during pregnancy re-synchronized the acrophases and restored mean temperature to the values in control newborns. Our findings demonstrate that prenatal melatonin is a Zeitgeber for the newborn temperature rhythm and supports normal body temperature maintenance. Altogether these prenatal melatonin effects highlight the physiological importance of the maternal melatonin rhythm during pregnancy for the newborn primate.

  4. Endogenous, photoperiodic and hormonal control of the body weight rhythm in the female European hamster, Cricetus cricetus.

    Science.gov (United States)

    Canguilhem, B; Masson-Pévet, M; Pévet, P; Bentz, I

    1992-03-01

    1. Body weight and hibernation rhythms were followed on normal and castrated female European hamsters raised in different conditions of photoperiod and ambient temperature. 2. In the normal females, the photoperiod was more effective than the ambient temperature regarding the control of the body weight rhythm. 3. In the castrated females, testosterone was more effective than oestradiol in suppressing both body weight and hibernation rhythms. 4. In short photoperiod conditions, the existence of endogenous rhythmicity depends upon prior photoperiodic exposure of the animals.

  5. Normalizing effect of bright light therapy on temperature circadian rhythm in patients with eating disorders.

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    Yamamotová, Anna; Papezová, Hana; Vevera, Jan

    2008-02-01

    Light and food are important synchronizers of circadian rhythmicity. In eating disorders, the circadian rhythms of food intake and temperature are abnormal. We analyzed the effect of the morning light application on the circadian rhythm of tympanic temperature and its association with hunger and mood changes in the sample of 25 female patients hospitalized with DSM-IV diagnosis of eating disorders (14 bulimia nervosa and 11 anorexia nervosa) and in 6 healthy women. Light therapy reduced interindividual variability of the temperature acrophase, synchronized the temperature and hunger rhythms and showed an antidepressant effect on patients with eating disorders. Bright light therapy normalized the circadian rhythm of body temperature in both anorexic and bulimic patients: phase advanced rhythm was delayed and phase delayed rhythm was advanced. In contrast with anorexic patients, the majority of bulimic patients had normal temperature rhythm before the therapy and this rhythm was not changed by the therapy. The light therapy normalized temperature circadian rhythm in patient with eating disorders. We hypothesize that the light therapy can also contribute to improvement of pathological eating pattern because of the functional connections between light and food entrained oscillators. The light may help to restore the irregular circadian rhythmicity induced by chaotic food intake.

  6. Altered energy intake and the amplitude of the body temperature rhythm are associated with changes in phase, but not amplitude, of clock gene expression in the rat suprachiasmatic nucleus in vivo.

    Science.gov (United States)

    Goh, Grace H; Mark, Peter J; Maloney, Shane K

    2016-01-01

    Circadian rhythms in mammals are driven by a central clock in the suprachiasmatic nucleus (SCN). In vitro, temperature cycles within the physiological range can act as potent entraining cues for biological clocks. We altered the body temperature (Tc) rhythm in rats by manipulating energy intake (EI) to determine whether EI-induced changes in Tc oscillations are associated with changes in SCN clock gene rhythms in vivo. Male Wistar rats (n = 16 per diet) were maintained on either an ad libitum diet (CON), a high energy cafeteria diet (CAF), or a calorie restricted diet (CR), and Tc was recorded every 30 min for 6-7 weeks. SCN tissue was harvested from rats at zeitgeber time (ZT) 0, ZT6, ZT12, or ZT18. Expression of the clock genes Bmal1, Per2, Cry1, and Rev-erbα, the heat shock transcription factor Hsf1, and the heat shock protein Hsp90aa1, were determined using qPCR. The circadian profile of gene expression for each gene was characterized using cosinor analysis. Compared to the CON rats, the amplitude of Tc was decreased in CAF rats by 0.1 °C (p  0.25). Compared to CON, phase advances of the Tc, Bmal1, and Per2 rhythms were observed with CR feeding (p < 0.05), but CAF feeding elicited no significant changes in phase. The present results indicate that in vivo, the SCN is largely resistant to entrainment by EI-induced changes in the Tc rhythm, although some phase entrainment may occur.

  7. The effects of gender on circadian rhythm of human physiological indexes in high temperature environment

    Science.gov (United States)

    Zheng, G. Z.; Li, K.; Bu, W. T.; Lu, Y. Z.; Wang, Y. J.

    2018-03-01

    In the context of frequent high temperature weather in recent years, peoples’ physical health is seriously threatened by the indoor high temperature. The physiological activities of human body show a certain changes of circadian rhythm. In this paper, the circadian rhythms of the physiological indexes in indoor high temperature environment were quantified and compared between the male subjects and female subjects. Ten subjects (five males and five females) were selected. The temperature conditions were set at 28°C, 32°C, 36°C and 38°C, respectively. The blood pressure, heart rate, rectal temperature, eardrum temperature, forehead temperature and mean skin temperature were measured for 24 hours continuously. The medians, amplitudes and acrophases of the circadian rhythms were obtained by the cosinor analysis method. Then the effects of gender on the circadian rhythm of the human body in high temperature environment were analyzed. The results indicate that, compared with the female subjects, the male medians of the systolic pressure and diastolic pressure were higher, and the male medians of heart rate and rectal temperature were lower, however, no significant differences were found between eardrum temperature, forehead temperature and mean skin temperature. This study can provide scientific basis for the health protection of the indoor relevant personnel.

  8. Body temperature variability (Part 2): masking influences of body temperature variability and a review of body temperature variability in disease.

    Science.gov (United States)

    Kelly, Gregory S

    2007-03-01

    This is the second of a two-part review on body temperature variability. Part 1 discussed historical and modern findings on average body temperatures. It also discussed endogenous sources of temperature variability, including variations caused by site of measurement; circadian, menstrual, and annual biological rhythms; fitness; and aging. Part 2 reviews the effects of exogenous masking agents - external factors in the environment, diet, or lifestyle that can be a significant source of body temperature variability. Body temperature variability findings in disease states are also reviewed.

  9. Uncovering different masking factors on wrist skin temperature rhythm in free-living subjects.

    Directory of Open Access Journals (Sweden)

    Antonio Martinez-Nicolas

    Full Text Available Most circadian rhythms are controlled by a major pacemaker located in the hypothalamic suprachiasmatic nucleus. Some of these rhythms, called marker rhythms, serve to characterize the timing of the internal temporal order. However, these variables are susceptible to masking effects as the result of activity, body position, light exposure, environmental temperature and sleep. Recently, wrist skin temperature (WT has been proposed as a new index for evaluating circadian system status. In light of previous evidence suggesting the important relationship between WT and core body temperature regulation, the aim of this work was to purify the WT pattern in order to obtain its endogenous rhythm with the application of multiple demasking procedures. To this end, 103 subjects (18-24 years old were recruited and their WT, activity, body position, light exposure, environmental temperature and sleep were recorded under free-living conditions for 1 week. WT demasking by categories or intercepts was applied to simulate a "constant routine" protocol (awakening, dim light, recumbent position, low activity and warm environmental temperature. Although the overall circadian pattern of WT was similar regardless of the masking effects, its amplitude was the rhythmic parameter most affected by environmental conditions. The acrophase and mesor were determined to be the most robust parameters for characterizing this rhythm. In addition, a circadian modulation of the masking effect was found for each masking variable. WT rhythm exhibits a strong endogenous component, despite the existence of multiple external influences. This was evidenced by simultaneously eliminating the influence of activity, body position, light exposure, environmental temperature and sleep. We therefore propose that it could be considered a valuable and minimally-invasive means of recording circadian physiology in ambulatory conditions.

  10. The relationship between insomnia and body temperatures

    NARCIS (Netherlands)

    Lack, L.C.; Gradisar, M.; van Someren, E.J.W.; Wright, H.R.; Lushington, K.

    2008-01-01

    Sleepiness and sleep propensity are strongly influenced by our circadian clock as indicated by many circadian rhythms, most commonly by that of core body temperature. Sleep is most conducive in the temperature minimum phase, but is inhibited in a "wake maintenance zone" before the minimum phase, and

  11. Body temperature norms

    Science.gov (United States)

    Normal body temperature; Temperature - normal ... Morrison SF. Regulation of body temperature. In: Boron WF, Boulpaep EL, eds. Medical Physiology . 3rd ed. Philadelphia, PA: Elsevier; 2017:chap 59. Sajadi MM, Mackowiak PA. ...

  12. Sleep, circadian rhythm and body weight: parallel developments.

    Science.gov (United States)

    Westerterp-Plantenga, Margriet S

    2016-11-01

    Circadian alignment is crucial for body-weight management, and for metabolic health. In this context, circadian alignment consists of alignment of sleep, meal patterns and physical activity. During puberty a significant reduction in sleep duration occurs, and pubertal status is inversely associated with sleep duration. A consistent inverse association between habitual sleep duration and body-weight development occurs, independent of possible confounders. Research on misalignment reveals that circadian misalignment affects sleep-architecture and subsequently disturbs glucose-insulin metabolism, substrate oxidation, leptin- and ghrelin concentrations, appetite, food reward, hypothalamic-pituitary-adrenal-axis activity and gut-peptide concentrations enhancing positive energy balance and metabolic disturbance. Not only aligning meals and sleep in a circadian way is crucial, also regular physical activity during the day strongly promotes the stability and amplitude of circadian rhythm, and thus may serve as an instrument to restore poor circadian rhythms. Endogenicity may play a role in interaction of these environmental variables with a genetic predisposition. In conclusion, notwithstanding the separate favourable effects of sufficient daily physical activity, regular meal patterns, sufficient sleep duration and quality sleep on energy balance, the overall effect of the amplitude and stability of the circadian rhythm, perhaps including genetic predisposition, may integrate the separate effects in an additive way.

  13. Disorders of body temperature.

    Science.gov (United States)

    Gomez, Camilo R

    2014-01-01

    The human body generates heat capable of raising body temperature by approximately 1°C per hour. Normally, this heat is dissipated by means of a thermoregulatory system. Disorders resulting from abnormally high or low body temperature result in neurologic dysfunction and pose a threat to life. In response to thermal stress, maintenance of normal body temperature is primarily maintained by convection and evaporation. Hyperthermia results from abnormal temperature regulation, leading to extremely elevated body temperature while fever results from a normal thermoregulatory mechanism operating at a higher set point. The former leads to specific clinical syndromes with inability of the thermoregulatory mechanism to maintain a constant body temperature. Heat related illness encompasses heat rash, heat cramps, heat exhaustion and heat stroke, in order of severity. In addition, drugs can induce hyperthermia and produce one of several specific clinical syndromes. Hypothermia is the reduction of body temperature to levels below 35°C from environmental exposure, metabolic disorders, or therapeutic intervention. Management of disorders of body temperature should be carried out decisively and expeditiously, in order to avoid secondary neurologic injury. © 2014 Elsevier B.V. All rights reserved.

  14. Thoracic surface temperature rhythms as circadian biomarkers for cancer chronotherapy

    Science.gov (United States)

    Roche, Véronique Pasquale; Mohamad-Djafari, Ali; Innominato, Pasquale Fabio; Karaboué, Abdoulaye; Gorbach, Alexander; Lévi, Francis Albert

    2014-01-01

    The disruption of the temperature circadian rhythm has been associated with cancer progression, while its amplification resulted in cancer inhibition in experimental tumor models. The current study investigated the relevance of skin surface temperature rhythms as biomarkers of the Circadian Timing System (CTS) in order to optimize chronotherapy timing in individual cancer patients. Baseline skin surface temperature at four sites and wrist accelerations were measured every minute for 4 days in 16 patients with metastatic gastro-intestinal cancer before chronotherapy administration. Temperature and rest-activity were recorded, respectively, with wireless skin surface temperature patches (Respironics, Phillips) and an actigraph (Ambulatory Monitoring). Both variables were further monitored in 10 of these patients during and after a 4-day course of a fixed chronotherapy protocol. Collected at baseline, during and after therapy longitudinal data sets were processed using Fast Fourier Transform Cosinor and Linear Discriminant Analyses methods. A circadian rhythm was statistically validated with a period of 24 h (p|0.7|; p<0.05). Individual circadian acrophases at baseline were scattered from 15:18 to 6:05 for skin surface temperature, and from 12:19 to 15:18 for rest-activity, with respective median values of 01:10 (25–75% quartiles, 22:35–3:07) and 14:12 (13:14–14:31). The circadian patterns in skin surface temperature and rest-activity persisted or were amplified during and after fixed chronotherapy delivery for 5/10 patients. In contrast, transient or sustained disruption of these biomarkers was found for the five other patients, as indicated by the lack of any statistically significant dominant period in the circadian range. No consistent correlation (r<|0.7|, p ≥ 0.05) was found between paired rest-activity and temperature time series during fixed chronotherapy delivery. In conclusion, large inter-patient differences in circadian amplitudes and acrophases of

  15. Circadian rhythm of rectal temperature during sleep deprivation with modafinil.

    Science.gov (United States)

    Launay, Jean-Claude; Savourey, Gustave; Guinet, Angélique; Lallement, Guy; Besnard, Yves; Bittel, Jacques

    2002-10-01

    Sleep deprivation (SD) induces many adverse psychological and physiological effects, particularly on vigilance and the thermoregulatory system. The drug modafinil appears to suppress or diminish the harmful effects on vigilance. However, the effects of modafinil combined with SD on the circadian rhythm of core temperature are not well established. We studied the circadian rhythm of rectal temperature (CRTre) during 62 h of SD alone or with three dosage levels of modafinil. Six men underwent repeated SD experiments lasting 7 d each, including a 24-h control period, 62 h of SD, and a 24-h recovery period. Experiments were repeated four times in mixed order for placebo and three levels of modafinil (50, 150, or 300 mg x 24 h(-1)). The Tre was recorded each minute throughout the experiment and the CRTre was studied by the single cosinor method. Independent of modafinil, SD increased the mesor (p modafinil, but not the higher doses, induced a lower mesor (p modafinil on core temperature. The hyperthermic effect reported in the literature for SD with modafinil may actually result from the sleep deprivation alone.

  16. Do rhythms exist in elbow flexor torque, oral temperature and muscle thickness during normal waking hours?

    Science.gov (United States)

    Buckner, Samuel L; Dankel, Scott J; Counts, Brittany R; Barnett, Brian E; Jessee, Matthew B; Mouser, J Grant; Halliday, Tanya M; Loenneke, Jeremy P

    2016-06-01

    The purpose of the current study was to examine the influence of "time" on isometric elbow flexion torque, body temperature and muscle size without interrupting the sleep wake cycle in college aged males. Two hours following the participants normal wake time, oral temperature was measured, followed by muscle thickness of the upper and lower body using ultrasound, as well as elbow flexor torque via a maximal voluntary contraction (MVC). Measurements were repeated every 2h for 12h (Time points 1-7). To examine the repeatability of the rhythm, participants returned and completed the same procedures as before within 14days of their first circadian visit (Circadian visit 2). There was no time×day interaction for body temperature (p=0.29), nor were there main effects for time (p=0.15) or day (p=0.74). For MVC, there was no time×day interaction (p=0.93) or main effect for day (p=0.50), however, there was a main effect for time (p=0.01). MVC at time points 1 (86.4±6.4Nm) and 2 (87.1±6.2Nm) was greater than time points 4 (84.2±6.6Nm) and 6 (83.4±6.8Nm, pmuscle thickness, there was no time×day interaction (p=0.34), nor was there a main effect for day (p=0.38), or time (p=0.06). For lower body muscle thickness, there was no time×day interaction (p=0.57), nor was there a main effect for day (p=0.75), or time (p=0.13). Cosinor analyses revealed no group level rhythms for oral temperature, muscle thickness or strength (p>0.05), however, there were some individual rhythms noted for muscle thickness and strength. Results suggest that, when accounting for an individuals normal wake time, circadian rhythms of strength, temperature and muscle thickness are not apparent in most individuals. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Biological rhythms

    Science.gov (United States)

    Halberg, F.

    1975-01-01

    An overview is given of basic features of biological rhythms. The classification of periodic behavior of physical and psychological characteristics as circadian, circannual, diurnal, and ultradian is discussed, and the notion of relativistic time as it applies in biology is examined. Special attention is given to circadian rhythms which are dependent on the adrenocortical cycle. The need for adequate understanding of circadian variations in the basic physiological indicators of an individual (heart rate, body temperature, systolic and diastolic blood pressure, etc.) to ensure the effectiveness of prophylactic and therapeutic measures is stressed.

  18. Temperature-amplitude coupling for stable biological rhythms at different temperatures.

    Science.gov (United States)

    Kurosawa, Gen; Fujioka, Atsuko; Koinuma, Satoshi; Mochizuki, Atsushi; Shigeyoshi, Yasufumi

    2017-06-01

    Most biological processes accelerate with temperature, for example cell division. In contrast, the circadian rhythm period is robust to temperature fluctuation, termed temperature compensation. Temperature compensation is peculiar because a system-level property (i.e., the circadian period) is stable under varying temperature while individual components of the system (i.e., biochemical reactions) are usually temperature-sensitive. To understand the mechanism for period stability, we measured the time series of circadian clock transcripts in cultured C6 glioma cells. The amplitudes of Cry1 and Dbp circadian expression increased significantly with temperature. In contrast, other clock transcripts demonstrated no significant change in amplitude. To understand these experimental results, we analyzed mathematical models with different network topologies. It was found that the geometric mean amplitude of gene expression must increase to maintain a stable period with increasing temperatures and reaction speeds for all models studied. To investigate the generality of this temperature-amplitude coupling mechanism for period stability, we revisited data on the yeast metabolic cycle (YMC) period, which is also stable under temperature variation. We confirmed that the YMC amplitude increased at higher temperatures, suggesting temperature-amplitude coupling as a common mechanism shared by circadian and 4 h-metabolic rhythms.

  19. Circadian Rhythms

    Indian Academy of Sciences (India)

    IAS Admin

    hunger and sleep at the same time as the body would not be in the right state to metabolise food efficiently. Thus, synchronization of internal rhythms is an essential aspect of physiology, and circadian rhythms benefit living beings by bringing about such temporal order. In other words, circadian rhythms are thought to.

  20. Dinosaur Fossils Predict Body Temperatures

    Science.gov (United States)

    Allen, Andrew P; Charnov, Eric L

    2006-01-01

    Perhaps the greatest mystery surrounding dinosaurs concerns whether they were endotherms, ectotherms, or some unique intermediate form. Here we present a model that yields estimates of dinosaur body temperature based on ontogenetic growth trajectories obtained from fossil bones. The model predicts that dinosaur body temperatures increased with body mass from approximately 25 °C at 12 kg to approximately 41 °C at 13,000 kg. The model also successfully predicts observed increases in body temperature with body mass for extant crocodiles. These results provide direct evidence that dinosaurs were reptiles that exhibited inertial homeothermy. PMID:16817695

  1. Dinosaur fossils predict body temperatures.

    Directory of Open Access Journals (Sweden)

    James F Gillooly

    2006-07-01

    Full Text Available Perhaps the greatest mystery surrounding dinosaurs concerns whether they were endotherms, ectotherms, or some unique intermediate form. Here we present a model that yields estimates of dinosaur body temperature based on ontogenetic growth trajectories obtained from fossil bones. The model predicts that dinosaur body temperatures increased with body mass from approximately 25 degrees C at 12 kg to approximately 41 degrees C at 13,000 kg. The model also successfully predicts observed increases in body temperature with body mass for extant crocodiles. These results provide direct evidence that dinosaurs were reptiles that exhibited inertial homeothermy.

  2. Central control of body temperature.

    Science.gov (United States)

    Morrison, Shaun F

    2016-01-01

    Central neural circuits orchestrate the behavioral and autonomic repertoire that maintains body temperature during environmental temperature challenges and alters body temperature during the inflammatory response and behavioral states and in response to declining energy homeostasis. This review summarizes the central nervous system circuit mechanisms controlling the principal thermoeffectors for body temperature regulation: cutaneous vasoconstriction regulating heat loss and shivering and brown adipose tissue for thermogenesis. The activation of these thermoeffectors is regulated by parallel but distinct efferent pathways within the central nervous system that share a common peripheral thermal sensory input. The model for the neural circuit mechanism underlying central thermoregulatory control provides a useful platform for further understanding of the functional organization of central thermoregulation, for elucidating the hypothalamic circuitry and neurotransmitters involved in body temperature regulation, and for the discovery of novel therapeutic approaches to modulating body temperature and energy homeostasis.

  3. Correlation of hippocampal theta rhythm with changes in cutaneous temperature. [evoked neuron response in thermoregulation

    Science.gov (United States)

    Horowitz, J. M.; Saleh, M. A.; Karem, R. D.

    1974-01-01

    A possible role for the hippocampus in alerting an animal to changes in cutaneous temperature was examined. Following local warming or cooling of the ears of unanesthetized, loosely restrained rabbits, theta waves (4-7 Hz EEG waves) were recorded from electrodes straddling the hippocampus. The onset of the hippocampal theta rhythm was correlated with changes in cutaneous temperature, an observation consistent with studies indicating that the theta rhythm is a nonspecific response evoked by stimulation of several sensory modalities. Additional data from cats and rabbits were correlated with specific neurons within the hippocampus, namely pyramidal cells. Post stimulus time histograms obtained by excitation of the dorsal fornix were interpreted in terms of excitatory and inhibitory inputs to pyramidal cells. Thus, the theta rhythm, which appears to be evoked by changes in cutaneous temperature, can be related to a specific type of hippocampal neuron which is in turn connected with other areas of the brain involved in temperature regulation.

  4. Portable Body Temperature Conditioner

    Science.gov (United States)

    2014-12-01

    patients become hypothermic after severe injury due to environmental exposure during transport. These patients also have decreased thermoregulation due to...based on the load demand to conserve power consumption 4 Requires glycol solution to prevent H20 freezing at cold ambient temperatures 3. Product...three days. To encompass the range of the temperature to be used during the Patient Simulation testing (15oC – 40oC); cold (15oC), neutral (25oC

  5. Core body temperature in obesity.

    Science.gov (United States)

    Heikens, Marc J; Gorbach, Alexander M; Eden, Henry S; Savastano, David M; Chen, Kong Y; Skarulis, Monica C; Yanovski, Jack A

    2011-05-01

    A lower core body temperature set point has been suggested to be a factor that could potentially predispose humans to develop obesity. We tested the hypothesis that obese individuals have lower core temperatures than those in normal-weight individuals. In study 1, nonobese [body mass index (BMI; in kg/m(2)) temperature-sensing capsules, and we measured core temperatures continuously for 24 h. In study 2, normal-weight (BMI of 18-25) and obese subjects swallowed temperature-sensing capsules to measure core temperatures continuously for ≥48 h and kept activity logs. We constructed daily, 24-h core temperature profiles for analysis. Mean (±SE) daily core body temperature did not differ significantly between the 35 nonobese and 46 obese subjects (36.92 ± 0.03°C compared with 36.89 ± 0.03°C; P = 0.44). Core temperature 24-h profiles did not differ significantly between 11 normal-weight and 19 obese subjects (P = 0.274). Women had a mean core body temperature ≈0.23°C greater than that of men (36.99 ± 0.03°C compared with 36.76 ± 0.03°C; P body temperature. It may be necessary to study individuals with function-altering mutations in core temperature-regulating genes to determine whether differences in the core body temperature set point affect the regulation of human body weight. These trials were registered at clinicaltrials.gov as NCT00428987 and NCT00266500.

  6. Locomotor Activity and Body Temperature Patterns over a Temperature Gradient in the Highveld Mole-Rat (Cryptomys hottentotus pretoriae).

    Science.gov (United States)

    Haupt, Meghan; Bennett, Nigel C; Oosthuizen, Maria K

    2017-01-01

    African mole-rats are strictly subterranean mammals that live in extensive burrow systems. High humidity levels in the burrows prevent mole-rats from thermoregulating using evaporative cooling. However, the relatively stable environment of the burrows promotes moderate temperatures and small daily temperature fluctuations. Mole-rats therefore display a relatively wide range of thermoregulation abilities. Some species cannot maintain their body temperatures at a constant level, whereas others employ behavioural thermoregulation. Here we test the effect of ambient temperature on locomotor activity and body temperature, and the relationship between the two parameters, in the highveld mole-rat. We exposed mole-rats to a 12L:12D and a DD light cycle at ambient temperatures of 30°C, 25°C and 20°C while locomotor activity and body temperature were measured simultaneously. In addition, we investigated the endogenous rhythms of locomotor activity and body temperature at different ambient temperatures. Mole-rats displayed nocturnal activity at all three ambient temperatures and were most active at 20°C, but least active at 30°C. Body temperature was highest at 30°C and lowest at 20°C, and the daily cycle was highly correlated with locomotor activity. We show that the mole-rats have endogenous rhythms for both locomotor activity and body temperature. However, the endogenous body temperature rhythm appears to be less robust compared to the locomotor activity rhythm. Female mole-rats appear to be more sensitive to temperature changes than males, increased heterothermy is evident at lower ambient temperatures, whilst males show smaller variation in their body temperatures with changing ambient temperatures. Mole-rats may rely more heavily on behavioural thermoregulation as it is more energy efficient in an already challenging environment.

  7. On the Mechanism of Reinitiation of Endogenous Crassulacean Acid Metabolism Rhythm by Temperature Changes.

    Science.gov (United States)

    Grams, TEE.; Borland, A. M.; Roberts, A.; Griffiths, H.; Beck, F.; Luttge, U.

    1997-01-01

    Under continuous light the endogenous Crassulacean acid metabolism (CAM) rhythm of Kalanchoe daigremontiana Hamet et Perrier de la Bathie disappears at high (>29.0[deg]C) or low (<8.0[deg]C) temperatures. We investigated the reinitiation of rhythmicity when temperature was reduced from above the upper and increased from below the lower threshold level via measurements of (a) short-term changes in carbon-isotope discrimination to illustrate shifts between C3 and C4 carboxylation in vivo, and (b) the malate sensitivity of phosphoenolpyruvate carboxylase (PEPC) in vitro. When the net CO2-exchange rhythm disappears at both temperatures, the instantaneous discrimination indicates low PEPC activity. Leaf malate concentration and osmolarity attain high and low values at low and high temperatures, respectively. After small temperature increases or reductions from the low and high temperatures, respectively, the rhythm is reinitiated, with phases shifted by 180[deg] relative to each other. This can be related to the contrasting low and high leaf malate concentrations due to direct inhibition of PEPC and possibly also of the phosphorylation of PEPC by malate. The experimental results were satisfactorily simulated by a mathematical CAM-cycle model, with temperature acting only on the passive efflux of malate from the vacuole. We stress the important role of the tonoplast in malate compartmentation and of malate itself for the reinitiation and generation of endogenous CAM rhythmicity. PMID:12223675

  8. The rhythms of life: what your body clock means to you!

    Science.gov (United States)

    Foster, Russell G; Kreitzman, Leon

    2014-04-01

    Until we turned our nights into days and began to travel in aircraft across multiple time zones, we were largely unaware that we possess a 'day within' driven by an internal body clock. Yet the striking impairment of our abilities in the early hours of the morning soon reminds us that we are slaves to our biology. Our ability to perform mathematical calculations or other intellectual tasks between 04.00 and 06.00 h is worse than if we had consumed several shots of whisky and would be classified as legally drunk. Biological clocks drive or alter our sleep patterns, alertness, mood, physical strength, blood pressure and every other aspect of our physiology and behaviour. Our emerging understanding of how these 24 h rhythms are generated and regulated is not only one of the great success stories of modern biology, but is also informing many areas of human health. Sleep and circadian rhythm disruption (SCRD) is a feature shared by some of the most challenging diseases of our time, including neuropsychiatric illness and serious disorders of the eye. Sleep and circadian rhythm disruption is also commonly seen across many sectors of society, from teenagers to shift workers. We also now appreciate that SCRD is far more than feeling sleepy at an inappropriate time. It promotes multiple illnesses ranging across abnormal metabolism, heart disease, reduced immunity, increased stress and abnormal cognition and mood states. This short review considers how 24 h rhythms are generated and regulated, the consequences of working against our body clock and the emerging relationship between SCRD and mental illness.

  9. Biological Rhythms and Temperature Regulation in Rhesus Monkeys During Spaceflight

    Science.gov (United States)

    Fuller, Charles A. (Principal Investigator)

    1996-01-01

    This program examined the influence of microgravity on temperature regulation and circadian timekeeping systems in Rhesus monkeys. Animals flown on the Soviet Biosatellite COSMOS 2229 were exposed to 11 2/3 days of microgravity. The circadian patterns temperature regulation, heart rate and activity were monitored constantly. This experiment has extended previous observations from COSMOS 1514 and 2044, as well as provided insights into the physiological mechanisms that produce these changes.

  10. Diurnal rhythm and effect of temperature on oxygen consumption in earthworms, Amynthas gracilis and Pontoscolex corethrurus.

    Science.gov (United States)

    Chuang, Shu Chun; Lee, Hsinyu; Chen, Jiun Hong

    2004-09-01

    Different species of earthworms show distinct patterns of oxygen consumption pattern. Amynthas gracilis has a diurnal rhythm of oxygen consumption, consuming more oxygen at night, whether being incubated at 20, 25, or 30 degrees C. The higher oxygen consumption of A. gracilis is directly related to its behavior, as it shows higher activity at night. In contrast, Pontoscolex corethrurus showed no obvious diurnal rhythms of oxygen consumption or behavior. In addition, its oxygen demand is not related to temperature. A. gracilis has higher oxygen consumption than P. corethrurus at 20 and 30 degrees C. The difference in temperature adaptation of oxygen consumption between these two species may be a strategy by which earthworms adapt to different temperatures. This might explain why A. gracilis disperses on the soil surface at night after a rain, in contrast to P. corethrurus for which such behavior was not been observed.

  11. A novel algorithm for detecting human circadian rhythms using a thoracic temperature sensor

    Directory of Open Access Journals (Sweden)

    Aly Chkeir

    2017-07-01

    Full Text Available Circadian rhythms undergo high perturbations due to cancer progression and worsening of metabolic diseases. This paper proposes an original method for detecting such perturbations using a novel thoracic temperature sensor. Such an infrared sensor records the skin temperature every five minutes, although some data might be missing. In this pilot study, five control subjects were evaluated over four days of recordings. In order to overcome the problem of missing data, first four different interpolation methods were compared. Using interpolation helps covering the gaps and extending the recordings frequency, subsequently prolonging sensor battery life. Afterwards, a Cosinor model was proposed to characterize circadian rhythms, and extract relevant parameters, with their confidence limits. A divergence study is then performed to detect changes in these parameters. The results are promising, supporting the enlargement of the sample size and warranting further assessment in cancer patients.

  12. Sleep-wake profiles and circadian rhythms of core temperature and melatonin in young people with affective disorders.

    Science.gov (United States)

    Carpenter, Joanne S; Robillard, Rébecca; Hermens, Daniel F; Naismith, Sharon L; Gordon, Christopher; Scott, Elizabeth M; Hickie, Ian B

    2017-11-01

    While disturbances of the sleep-wake cycle are common in people with affective disorders, the characteristics of these disturbances differ greatly between individuals. This heterogeneity is likely to reflect multiple underlying pathophysiologies, with different perturbations in circadian systems contributing to the variation in sleep-wake cycle disturbances. Such disturbances may be particularly relevant in adolescents and young adults with affective disorders as circadian rhythms undergo considerable change during this key developmental period. This study aimed to identify profiles of sleep-wake disturbance in young people with affective disorders and investigate associations with biological circadian rhythms. Fifty young people with affective disorders and 19 control participants (aged 16-31 years) underwent actigraphy monitoring for approximately two weeks to derive sleep-wake cycle parameters, and completed an in-laboratory assessment including evening dim-light saliva collection for melatonin assay and overnight continuous core body temperature measurement. Cluster analysis based on sleep-wake cycle parameters identified three distinct patient groups, characterised by 'delayed sleep-wake', 'disrupted sleep', and 'long sleep' respectively. The 'delayed sleep-wake' group had both delayed melatonin onset and core temperature nadir; whereas the other two cluster groups did not differ from controls on these circadian markers. The three groups did not differ on clinical characteristics. These results provide evidence that only some types of sleep-wake disturbance in young people with affective disorders are associated with fundamental circadian perturbations. Consequently, interventions targeting endogenous circadian rhythms to promote a phase shift may be particularly relevant in youth with affective disorders presenting with delayed sleep-wake cycles. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Circadian body temperature variability is an indicator of poor prognosis in cardiomyopathic hamsters.

    Science.gov (United States)

    Ahmed, Amany; Gondi, Sreedevi; Cox, Casey; Wang, Suwei; Stupin, Igor V; Shankar, K J; Munir, Shahzeb M; Sobash, Ed; Brewer, Alan; Ferguson, James J; Elayda, Macarthur A; Casscells, S Ward; Wilson, James M

    2010-03-01

    Low body temperature is an independent predictor of poor prognosis in patients with congestive heart failure. The cardiomyopathic hamster develops progressive biventricular dysfunction, resulting in heart failure death at 9 months to 1 year of life. Our goal was to use cardiomyopathic hamsters to examine the relationship between body temperature and heart failure decompensation and death. To this end, we implanted temperature and activity transducers with telemetry into the peritoneal space of 46 male Bio-TO-2 Syrian cardiomyopathic hamsters. Multiple techniques, including computing mean temperature, frequency domain analysis, and nonlinear analysis, were used to determine the most useful method for predicting poor prognosis. Data from 44 hamsters were included in our final analysis. We detected a decline in core body temperature in 98% of the hamsters 8+/-4 days before death (P temperature variation (ie, the circadian rhythm) by using cosinor analysis, which revealed a significant decrease in the amplitude of the body temperature circadian rhythm 8 weeks before death (0.28 degrees C; 95% CI, 0.26-0.31) compared to baseline (0.36 degrees C; 95% CI, 0.34-0.39; P=.005). The decline in the circadian temperature variation preceded all other evidence of decompensation. We conclude that a decrease in the amplitude of the body temperature circadian rhythm precedes fatal decompensation in cardiomyopathic hamsters. Continuous temperature monitoring may be useful in predicting preclinical decompensation in patients with heart failure and in identifying opportunities for therapeutic intervention. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  14. Relationship between body temperature and air temperature in ...

    African Journals Online (AJOL)

    Body temperatures of singing male Gryllus bimaculatus were measured for the first time. Body temperatures were strongly correlated with ambient temperature. This indicates that, unlike some other orthopterans, larger crickets are not dependent on an elevated body temperature for efficient calling. Our results confirm that it ...

  15. Circadian Melatonin and Temperature Taus in Delayed Sleep-wake Phase Disorder and Non-24-hour Sleep-wake Rhythm Disorder Patients: An Ultradian Constant Routine Study.

    Science.gov (United States)

    Micic, Gorica; Lovato, Nicole; Gradisar, Michael; Burgess, Helen J; Ferguson, Sally A; Lack, Leon

    2016-08-01

    Our objectives were to investigate the period lengths (i.e., taus) of the endogenous core body temperature rhythm and melatonin rhythm in delayed sleep-wake phase disorder patients (DSWPD) and non-24-h sleep-wake rhythm disorder patients (N24SWD) compared with normally entrained individuals. Circadian rhythms were measured during an 80-h ultradian modified constant routine consisting of 80 ultrashort 1-h "days" in which participants had 20-min sleep opportunities alternating with 40 min of enforced wakefulness. We recruited a community-based sample of 26 DSWPD patients who met diagnostic criteria (17 males, 9 females; age, 21.85 ± 4.97 years) and 18 healthy controls (10 males, 8 females; age, 23.72 ± 5.10 years). Additionally, 4 full-sighted patients (3 males, 1 female; age, 25.75 ± 4.99 years) were diagnosed with N24SWD and included as a discrete study group. Ingestible core temperature capsules were used to record minute temperatures that were averaged to obtain 80 hourly data points. Salivary melatonin concentration was assessed every half-hour to determine time of dim light melatonin onset at the beginning and end of the 80-h protocol. DSWPD patients had significantly longer melatonin rhythm taus (24 h 34 min ± 17 min) than controls (24 h 22 min ± 15 min, p = 0.03, d = 0.70). These results were further supported by longer temperature rhythm taus in DSWPD patients (24 h 34 min ± 26 min) relative to controls (24 h 13 min ± 15 min, p = 0.01, d = 0.80). N24SWD patients had even longer melatonin (25 h ± 19 min) and temperature (24 h 52 min ± 17 min) taus than both DSWPD (p = 0.007, p = 0.06) and control participants (p sleep timing could be explained by longer taus. This indicates that longer taus of circadian rhythms may contribute to the DSWPD patients' persistent tendency to delay, their frequent failure to respond to treatment, and their relapse following treatment. Additionally, other factors can contribute to misalignments in DSWPD and N24SWD

  16. Temporal phasing of locomotor activity, heart rate rhythmicity, and core body temperature is disrupted in VIP receptor 2-deficient mice

    DEFF Research Database (Denmark)

    Hannibal, Jens; Hsiung, Hansen M; Fahrenkrug, Jan

    2011-01-01

    Neurons of the brain's biological clock located in the hypothalamic suprachiasmatic nucleus (SCN) generate circadian rhythms of physiology (core body temperature, hormone secretion, locomotor activity, sleep/wake, and heart rate) with distinct temporal phasing when entrained by the light/dark (LD...... these observations with observations made from mice examined by wheel-running activity. The study demonstrates that VPAC2 signaling is necessary for a functional circadian clock driving locomotor activity, core body temperature, and heart rate rhythmicity, since VPAC2-deficient mice lose the rhythms in all three...... parameters when placed under constant conditions (of either light or darkness). Furthermore, although 24-h rhythms for three parameters are retained in VPAC2-deficient mice during the LD cycle, the temperature rhythm displays markedly altered time course and profile, rising earlier and peaking ~4-6 h prior...

  17. Environmental light and suprachiasmatic nucleus interact in the regulation of body temperature.

    NARCIS (Netherlands)

    Scheer, F.A.J.L.; Pirovano, C.; Someren, E.J.W. van; Buijs, R.M.

    2005-01-01

    The mammalian biological clock, located in the suprachiasmatic nucleus (SCN), is crucial for circadian rhythms in physiology and behavior. However, equivocal findings have been reported on its role in the circadian regulation of body temperature. The goal of the present studies was to investigate

  18. Relationship between body temperature and air temperature In ...

    African Journals Online (AJOL)

    1992-06-22

    Jun 22, 1992 ... Considering the fact that insect stridulation may be associated with elevated body temperature, it is most appropriate to investigate the correlation between ambient temperature and body tempera- ture of calling males of this species. This is the first time that the body temperatures of a grylline cricket species ...

  19. Circadian temperature and melatonin rhythms, sleep, and neurobehavioral function in humans living on a 20-h day

    Science.gov (United States)

    Wyatt, J. K.; Ritz-De Cecco, A.; Czeisler, C. A.; Dijk, D. J.

    1999-01-01

    The interaction of homeostatic and circadian processes in the regulation of waking neurobehavioral functions and sleep was studied in six healthy young subjects. Subjects were scheduled to 15-24 repetitions of a 20-h rest/activity cycle, resulting in desynchrony between the sleep-wake cycle and the circadian rhythms of body temperature and melatonin. The circadian components of cognitive throughput, short-term memory, alertness, psychomotor vigilance, and sleep disruption were at peak levels near the temperature maximum, shortly before melatonin secretion onset. These measures exhibited their circadian nadir at or shortly after the temperature minimum, which in turn was shortly after the melatonin maximum. Neurobehavioral measures showed impairment toward the end of the 13-h 20-min scheduled wake episodes. This wake-dependent deterioration of neurobehavioral functions can be offset by the circadian drive for wakefulness, which peaks in the latter half of the habitual waking day during entrainment. The data demonstrate the exquisite sensitivity of many neurobehavioral functions to circadian phase and the accumulation of homeostatic drive for sleep.

  20. Effects of Restricted Fructose Access on Body Weight and Blood Pressure Circadian Rhythms

    Directory of Open Access Journals (Sweden)

    Danielle Senador

    2012-01-01

    Full Text Available High-fructose diet is known to produce cardiovascular and metabolic pathologies. The objective was to determine whether the timing of high fructose (10% liquid solution intake affect the metabolic and cardiovascular outcomes. Male C57BL mice with radiotelemetric probes were divided into four groups: (1 24 h water (control; (2 24 h fructose (F24; (3 12 h fructose during the light phase (F12L; (4 12 h fructose during the dark phase (F12D. All fructose groups had higher fluid intake. Body weight was increased in mice on restricted access with no difference in total caloric intake. Fasting glycemia was higher in groups with restricted access. F24 mice showed a fructose-induced blood pressure increase during the dark period. Blood pressure circadian rhythms were absent in F12L mice. Results suggest that the timing of fructose intake is an important variable in the etiology of cardiovascular and metabolic pathologies produced by high fructose consumption.

  1. Effects of temperature and photoperiod on daily activity rhythms of Lutzomyia longipalpis (Diptera: Psychodidae).

    Science.gov (United States)

    Rivas, Gustavo B S; de Souza, Nataly Araujo; Peixoto, Alexandre A; Bruno, Rafaela V

    2014-06-19

    Insect vectors have been established as models in Chronobiology for many decades, and recent studies have demonstrated a close relationship between the circadian clock machinery, daily rhythms of activity and vectorial capacity. Lutzomyia longipalpis, the primary vector of Leishmania (Leishmania) infantum in the New World, is reported to have crepuscular/nocturnal activity in the wild. However, most of these studies applied hourly CDC trap captures, which is a good indicative of L. longipalpis behaviour, but has limited accuracy due to the inability to record the daily activity of a single insect during consecutive days. In addition, very little is known about the activity pattern of L. longipalpis under seasonal variations of average temperature and day length in controlled laboratory conditions. We recorded the locomotor activity of L. longipalpis males under different artificial regimes of temperature and photoperiod. First, in order to test the effects of temperature on the activity, sandflies were submitted to regimes of light/dark cycles similar to the equinox photoperiod (LD 12:12) combined with different constant temperatures (20°C, 25°C and 30°C). In addition, we recorded sandfly locomotor activity under a mild constant temperature (25°C with different day length regimes: 8 hours, 12 hours and 16 hours). L. longipalpis exhibited more activity at night, initiating dusk-related activity (onset time) at higher rather than lower temperatures. In parallel, changes of photoperiod affected anticipation as well as all the patterns of activity (onset, peak and offset time). However, under LD 16:08, sandflies presented the earliest values of maximum peak and offset times, contrary to other regimes. Herein, we showed that light and temperature modulate L. longipalpis behaviour under controlled laboratory conditions, suggesting that sandflies might use environmental information to sustain their crepuscular/nocturnal activity, as well as other important aspects as

  2. Body Temperature Regulation in Hot Environments.

    Science.gov (United States)

    Nilsson, Jan-Åke; Molokwu, Mary Ngozi; Olsson, Ola

    2016-01-01

    Organisms in hot environments will not be able to passively dissipate metabolically generated heat. Instead, they have to revert to evaporative cooling, a process that is energetically expensive and promotes excessive water loss. To alleviate these costs, birds in captivity let their body temperature increase, thereby entering a state of hyperthermia. Here we explore the use of hyperthermia in wild birds captured during the hot and dry season in central Nigeria. We found pronounced hyperthermia in several species with the highest body temperatures close to predicted lethal levels. Furthermore, birds let their body temperature increase in direct relation to ambient temperatures, increasing body temperature by 0.22°C for each degree of increased ambient temperature. Thus to offset the costs of thermoregulation in ambient temperatures above the upper critical temperature, birds are willing to let their body temperatures increase by up to 5°C above normal temperatures. This flexibility in body temperature may be an important mechanism for birds to adjust to predicted increasing ambient temperatures in the future.

  3. Chronotype differences in circadian rhythms of temperature, melatonin, and sleepiness as measured in a modified constant routine protocol

    Directory of Open Access Journals (Sweden)

    Leon Lack

    2009-11-01

    Full Text Available Leon Lack, Michelle Bailey, Nicole Lovato, Helen WrightSchool of Psychology, Flinders University, Adelaide, South Australia, AustraliaAbstract: Evening chronotypes typically have sleep patterns timed 2–3 hours later than morning chronotypes. Ambulatory studies have suggested that differences in the timing of underlying circadian rhythms as a cause of the sleep period differences. However, differences in endogenous circadian rhythms are best explored in laboratory protocols such as the constant routine. We used a 27-hour modified constant routine to measure the endogenous core temperature and melatonin circadian rhythms as well as subjective and objective sleepiness from hourly 15-minute sleep opportunities. Ten (8f morning type individuals were compared with 12 (8f evening types. All were young, healthy, good sleepers. The typical sleep onset, arising times, circadian phase markers for temperature and melatonin and objective sleepiness were all 2–3 hours later for the evening types than morning types. However, consistent with past studies the differences for the subjective sleepiness rhythms were much greater (5–9 hours. Therefore, the present study supports the important role of subjective alertness/sleepiness in determining the sleep period differences between morning and evening types and the possible vulnerability of evening types to delayed sleep phase disorder.Keywords: chronotype, constant routine, circadian rhythms, sleep propensity, subjective sleepiness

  4. The relationship between body and ambient temperature and corneal temperature

    DEFF Research Database (Denmark)

    Kessel, Line; Johnson, Leif; Arvidsson, Henrik Sven

    2010-01-01

    Exposure to elevated ambient temperatures has been mentioned as a risk factor for common eye diseases, primarily presbyopia and cataract. The aim of the present study was to examine the relationship among ambient, cornea, and body core temperature.......Exposure to elevated ambient temperatures has been mentioned as a risk factor for common eye diseases, primarily presbyopia and cataract. The aim of the present study was to examine the relationship among ambient, cornea, and body core temperature....

  5. Astronaut James Lovell checks body temperature with oral temperature probe

    Science.gov (United States)

    1965-01-01

    Gemini 7 pilot Astronaut James A. Lovell Jr. has temperature check with oral temperature probe attached to his space suit during final preflight preparations for the Gemini 7 space mission. The temperature probe allows doctors to monitor astronauts body temperature at any time during the mission.

  6. Temporal phasing of locomotor activity, heart rate rhythmicity, and core body temperature is disrupted in VIP receptor 2-deficient mice

    DEFF Research Database (Denmark)

    Hannibal, Jens; Hsiung, Hansen M; Fahrenkrug, Jan

    2011-01-01

    Neurons of the brain's biological clock located in the hypothalamic suprachiasmatic nucleus (SCN) generate circadian rhythms of physiology (core body temperature, hormone secretion, locomotor activity, sleep/wake, and heart rate) with distinct temporal phasing when entrained by the light/dark (LD...... these observations with observations made from mice examined by wheel-running activity. The study demonstrates that VPAC2 signaling is necessary for a functional circadian clock driving locomotor activity, core body temperature, and heart rate rhythmicity, since VPAC2-deficient mice lose the rhythms in all three...

  7. Predicting body temperature of endotherms during shuttling

    NARCIS (Netherlands)

    Rodriguez-Girones, M.A.

    2002-01-01

    This paper presents two models that can be used to predict the temporal dynamics of body temperature in endotherms. A first-order model is based on the assumption that body temperature is uniform at all times, while a second-order model is based on the assumption that animals can be divided in a

  8. Assessment of body temperature measurement options.

    Science.gov (United States)

    Sund-Levander, Märtha; Grodzinsky, Ewa

    Assessment of body temperature is important for decisions in nursing care, medical diagnosis, treatment and the need of laboratory tests. The definition of normal body temperature as 37°C was established in the middle of the 19th century. Since then the technical design and the accuracy of thermometers has been much improved. Knowledge of physical influence on the individual body temperature, such as thermoregulation and hormones, are still not taken into consideration in body temperature assessment. It is time for a change; the unadjusted mode should be used, without adjusting to another site and the same site of measurement should be used as far as possible. Peripheral sites, such as the axillary and the forehead site, are not recommended as an assessment of core body temperature in adults. Frail elderly individuals might have a low normal body temperature and therefore be at risk of being assessed as non-febrile. As the ear site is close to the hypothalamus and quickly responds to changes in the set point temperature, it is a preferable and recommendable site for measurement of body temperature.

  9. Psychology of the Embrace: How Body Rhythms Communicate the Need to Indulge or Separate.

    Science.gov (United States)

    Koch, Sabine C; Rautner, Helena

    2017-11-29

    In the context of embodiment research, there has been a growing interest in phenomena of interpersonal resonance. Given that haptic communication is particularly under-researched, we focused on the phenomenon of embracing. When we embrace a dear friend to say good-bye at the end of a great evening, we typically first employ smooth and yielding movements with round transitions between muscular tensing and relaxing ( smooth , indulging rhythms ), and when the embrace is getting too long, we start to use slight patting ( sharp , fighting rhythms with sharp transitions) on the back or the shoulders of the partner in order to indicate that we now want to end the embrace. On the ground of interpersonal resonance, most persons (per-sonare, latin = to sound through) understand these implicit nonverbal signals, expressed in haptic tension-flow changes, and will react accordingly. To experimentally test the hypothesis that smooth, indulgent rhythms signal the wish to continue, and sharp, fighting rhythms signal the wish to separate from an embrace, we randomly assigned 64 participants, all students at the University of Heidelberg, to two differently sequenced embrace conditions: (a) with the fighting rhythm at the end of the sequence of two indulgent rhythms (Sequence A: smooth-smooth-sharp); and (b) with the fighting rhythm between two indulgent rhythms (Sequence B: smooth-sharp-smooth). Participants were embraced for 30 s by a female confe-derate with their eyes blindfolded to focus on haptic and kinesthetic cues without being distracted by visual cues. They were instructed to let go of a handkerchief that they held between the fingers of their dominant hand during the embrace, when they felt that the embracer signaled the wish to finish the embrace. Participants significantly more often dropped the handkerchief in the phase of the fighting rhythm, no matter in which location it occurred in the embrace sequence. We assume that we learn such rhythmic behaviors and their

  10. Psychology of the Embrace: How Body Rhythms Communicate the Need to Indulge or Separate

    Directory of Open Access Journals (Sweden)

    Sabine C. Koch

    2017-11-01

    Full Text Available In the context of embodiment research, there has been a growing interest in phenomena of interpersonal resonance. Given that haptic communication is particularly under-researched, we focused on the phenomenon of embracing. When we embrace a dear friend to say good-bye at the end of a great evening, we typically first employ smooth and yielding movements with round transitions between muscular tensing and relaxing (smooth, indulging rhythms, and when the embrace is getting too long, we start to use slight patting (sharp, fighting rhythms with sharp transitions on the back or the shoulders of the partner in order to indicate that we now want to end the embrace. On the ground of interpersonal resonance, most persons (per-sonare, latin = to sound through understand these implicit nonverbal signals, expressed in haptic tension-flow changes, and will react accordingly. To experimentally test the hypothesis that smooth, indulgent rhythms signal the wish to continue, and sharp, fighting rhythms signal the wish to separate from an embrace, we randomly assigned 64 participants, all students at the University of Heidelberg, to two differently sequenced embrace conditions: (a with the fighting rhythm at the end of the sequence of two indulgent rhythms (Sequence A: smooth-smooth-sharp; and (b with the fighting rhythm between two indulgent rhythms (Sequence B: smooth-sharp-smooth. Participants were embraced for 30 s by a female confe­derate with their eyes blindfolded to focus on haptic and kinesthetic cues without being distracted by visual cues. They were instructed to let go of a handkerchief that they held between the fingers of their dominant hand during the embrace, when they felt that the embracer signaled the wish to finish the embrace. Participants significantly more often dropped the handkerchief in the phase of the fighting rhythm, no matter in which location it occurred in the embrace sequence. We assume that we learn such rhythmic behaviors and

  11. Core body temperature in obesity123

    Science.gov (United States)

    Heikens, Marc J; Gorbach, Alexander M; Eden, Henry S; Savastano, David M; Chen, Kong Y; Skarulis, Monica C

    2011-01-01

    Background: A lower core body temperature set point has been suggested to be a factor that could potentially predispose humans to develop obesity. Objective: We tested the hypothesis that obese individuals have lower core temperatures than those in normal-weight individuals. Design: In study 1, nonobese [body mass index (BMI; in kg/m2) <30] and obese (BMI ≥30) adults swallowed wireless core temperature–sensing capsules, and we measured core temperatures continuously for 24 h. In study 2, normal-weight (BMI of 18–25) and obese subjects swallowed temperature-sensing capsules to measure core temperatures continuously for ≥48 h and kept activity logs. We constructed daily, 24-h core temperature profiles for analysis. Results: Mean (±SE) daily core body temperature did not differ significantly between the 35 nonobese and 46 obese subjects (36.92 ± 0.03°C compared with 36.89 ± 0.03°C; P = 0.44). Core temperature 24-h profiles did not differ significantly between 11 normal-weight and 19 obese subjects (P = 0.274). Women had a mean core body temperature ≈0.23°C greater than that of men (36.99 ± 0.03°C compared with 36.76 ± 0.03°C; P < 0.0001). Conclusions: Obesity is not generally associated with a reduced core body temperature. It may be necessary to study individuals with function-altering mutations in core temperature–regulating genes to determine whether differences in the core body temperature set point affect the regulation of human body weight. These trials were registered at clinicaltrials.gov as NCT00428987 and NCT00266500. PMID:21367952

  12. Effect of body fat and gender on body temperature distribution.

    Science.gov (United States)

    Neves, Eduardo Borba; Salamunes, Ana Carla Chierighini; de Oliveira, Rafael Melo; Stadnik, Adriana Maria Wan

    2017-12-01

    It is well known that body composition can influence peripheral heat loss and skin temperature. That the distribution of body fat is affected by gender is well known; however, there is little information on how body composition and gender influences the measure of skin temperature. This study evaluated skin temperature distribution according to body fat percentage (BF%) and gender. A sample of 94 apparently healthy volunteers (47 women and 47 men) was assessed with Dual-Energy X-Ray Absorptiometry (DXA) and infrared thermography (mean, maximum and minimum temperatures - T Mean , T Max and T Min ). The sample was divided into groups, according to health risk classification, based on BF%, as proposed by the American College of Sports Medicine: Average (n = 58), Elevated (n = 16) or High (n = 20). Women had lower T Mean in most regions of interest (ROI). In both genders, group High had lower temperature values than Average and Elevated in the trunk, upper and lower limbs. In men, palms and posterior hands had a tendency (p temperature along with increased BF%. T Mean , T Max and T Min of trunk, upper and lower limbs were negatively correlated with BF% and the fat percentage of each segment (upper limbs, lower limbs and trunk). The highest correlations found in women were between posterior trunk and BF% (rho = -0.564, p temperature than men, which was related with higher BF%. Facial temperature seems not to be influenced by body fat. With the future collection of data on the relationship between BF% and skin temperature while taking into account factors such as body morphology, gender, and ethnicity, we conclude that measurement of BF may be reliably estimated with the use of thermal imaging technology. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Biomarkers for circadian rhythm disruption independent of time of day

    NARCIS (Netherlands)

    K.C.G. van Dycke (Kirsten); J.L.A. Pennings (Jeroen L.A.); C.T.M. van Oostrom (Conny); L.W.M. Van Kerkhof (Linda W.M.); H. van Steeg (Harry); G.T.J. van der Horst (Gijsbertus); W. Rodenburg (Wendy)

    2015-01-01

    textabstractFrequent shift work causes disruption of the circadian rhythm and might on the long-term result in increased health risk. Current biomarkers evaluating the presence of circadian rhythm disturbance (CRD), including melatonin, cortisol and body temperature, require 24-hr ("around the

  14. Disruption of the circadian period of body temperature by the anesthetic propofol.

    Science.gov (United States)

    Touitou, Yvan; Mauvieux, Benoit; Reinberg, Alain; Dispersyn, Garance

    2016-01-01

    The circadian time structure of an organism can be desynchronized in a large number of instances, including the intake of specific drugs. We have previously found that propofol, which is a general anesthetic, induces a desynchronization of the circadian time structure in rats, with a 60-80 min significant phase advance of body temperature circadian rhythm. We thus deemed it worthwhile to examine whether this phase shift of body temperature was related to a modification of the circadian period Tau. Propofol was administered at three different Zeitgeber Times (ZTs): ZT6 (middle of the rest period), ZT10 (2 h prior to the beginning of activity period), ZT16 (4 h after the beginning of the activity period), with ZT0 being the beginning of the rest period (light onset) and ZT12 being the beginning of the activity period (light offset). Control rats (n = 20) were injected at the same ZTs with 10% intralipid, which is a control lipidic solution. Whereas no modification of the circadian period of body temperature was observed in the control rats, propofol administration resulted in a significant shortening of the period by 96 and 180 min at ZT6 and ZT10, respectively. By contrast, the period was significantly lengthened by 90 min at ZT16. We also found differences in the time it took for the rats to readjust their body temperature to the original 24-h rhythm. At ZT16, the speed of readjustment was more rapid than at the two other ZTs that we investigated. This study hence shows (i) the disruptive effects of the anesthetic propofol on the body temperature circadian rhythm, and it points out that (ii) the period Tau for body temperature responds to this anesthetic drug according to a Tau-response curve. By sustaining postoperative sleep-wake disorders, the disruptive effects of propofol on circadian time structure might have important implications for the use of this drug in humans.

  15. Temporal phasing of locomotor activity, heart rate rhythmicity, and core body temperature is disrupted in VIP receptor 2-deficient mice

    DEFF Research Database (Denmark)

    Hannibal, Jens; Hsiung, Hansen M; Fahrenkrug, Jan

    2011-01-01

    to that of wild-type mice. The use of telemetric devices to measure circadian locomotor activity, temperature, and heart rate, together with the classical determination of circadian rhythms of wheel-running activity, raises questions about how representative wheel-running activity may be of other behavioral...... these observations with observations made from mice examined by wheel-running activity. The study demonstrates that VPAC2 signaling is necessary for a functional circadian clock driving locomotor activity, core body temperature, and heart rate rhythmicity, since VPAC2-deficient mice lose the rhythms in all three...

  16. CLOCK 3111T/C genetic variant influences the daily rhythm of autonomic nervous function: relevance to body weight control.

    Science.gov (United States)

    Lo, M-T; Bandin, C; Yang, H-W; Scheer, F A J L; Hu, K; Garaulet, M

    2018-02-01

    Humans carrying the genetic risk variant C at the circadian CLOCK (Circadian Locomotor Output Cycles Kaput) 3111T/C have been shown to have more difficulties to achieve desired weight loss than TT carriers. We tested the hypothesis that the daily rhythm of autonomic nervous function differs in CLOCK 3111C carriers, leading to reduced effectiveness in weight control. We recruited 40 overweight/obese Caucasian women (body mass index>25), 20 carrying CLOCK 3111C (CC and TC) and 20 non-carriers with matched age and body mass index who participated in a dietary obesity treatment program of up to 30 weeks. Following the treatment, ambulatory electrocardiography was continuously monitored for up to 3.5 days when subjects underwent their normal daily activities. To assess autonomic function, heart rate variability analysis (HRV) was performed hourly to obtain mean inter-beat interval between two consecutive R waves (mean RR) and s.d. of normal-to-normal heartbeat intervals (SDNN), and two parasympathetic measures, namely, proportion of differences between adjacent NN intervals that are >50 ms (pNN50), and high-frequency (HF: 0.15-0.4 Hz) power. In the TT carriers, all tested HRV indices showed significant daily rhythms (all P-values CLOCK variation on body weight control.

  17. Psychology of the Embrace: How Body Rhythms Communicate the Need to Indulge or Separate

    OpenAIRE

    Sabine C. Koch; Helena Rautner

    2017-01-01

    In the context of embodiment research, there has been a growing interest in phenomena of interpersonal resonance. Given that haptic communication is particularly under-researched, we focused on the phenomenon of embracing. When we embrace a dear friend to say good-bye at the end of a great evening, we typically first employ smooth and yielding movements with round transitions between muscular tensing and relaxing (smooth, indulging rhythms), and when the embrace is getting too long, we start ...

  18. Elevated body temperature during sleep in orexin knockout mice

    Science.gov (United States)

    Mochizuki, Takatoshi; Klerman, Elizabeth B.; Sakurai, Takeshi; Scammell, Thomas E.

    2008-01-01

    Core body temperature (Tb) is influenced by many physiological factors, including behavioral state, locomotor activity, and biological rhythms. To determine the relative roles of these factors, we examined Tb in orexin knockout (KO) mice, which have a narcolepsy-like phenotype with severe sleep-wake fragmentation. Because orexin is thought to promote heat production during wakefulness, we hypothesized that orexin KO mice would have lower Tb while awake. Surprisingly, the Tb of orexin KO mice was 0.4°C higher than wild-type (WT) littermates during the dark period. Orexin KO mice had normal diurnal variations in Tb, but the ultradian rhythms of Tb, locomotor activity, and wakefulness were markedly reduced. During sustained wakefulness, Tb was the same in both groups. During the first 15 min of spontaneous sleep, the Tb of WT mice decreased by 1.0°C, but Tb in orexin KO mice decreased only 0.4°C. Even during intense recovery sleep after 8 hr of sleep deprivation, the Tb of orexin KO mice remained 0.7°C higher than in WT mice. This blunted fall in Tb during sleep may be due to inadequate activation of heat loss mechanisms or sustained activity in heat-generating systems. These observations reveal an unexpected role for orexin in thermoregulation. In addition, because heat loss is an essential aspect of sleep, the blunted fall in Tb of orexin KO mice may provide an explanation for the fragmented sleep of narcolepsy. PMID:16556901

  19. Accuracy of the Estimated Core Temperature (ECTemp) Algorithm in Estimating Circadian Rhythm Indicators

    Science.gov (United States)

    2017-04-12

    optimization and heat illness prevention when training or in combat in stressful environments [9]. However, most methods of measuring CT are invasive...performance: implications for hormonal and muscular adaptation. J Sports Sci Med, 2011. 10(4): p. 600-6. 3. Halberg, F., G. Cornelissen, Z. Wang, C...ingestible telemetric body core temperature sensor: a review of validity and exercise applications. Br J Sports Med, 2007. 41(3): p. 126-33. 21

  20. Structural transition temperature of hemoglobins correlates with species' body temperature.

    Science.gov (United States)

    Zerlin, Kay Frank Thorsten; Kasischke, Nicole; Digel, Ilya; Maggakis-Kelemen, Christina; Temiz Artmann, Aysegül; Porst, Dariusz; Kayser, Peter; Linder, Peter; Artmann, Gerhard Michael

    2007-12-01

    Human red blood cells (RBCs) exhibit sudden changes in their biophysical properties at body temperature (T (B)). RBCs were seen to undergo a spontaneous transition from blockage to passage at T (C) = 36.4 +/- 0.3 degrees C, when the temperature dependency of RBC-passages through 1.3 mum narrow micropipettes was observed. Moreover, concentrated hemoglobin solutions (45 g/dl) showed a viscosity breakdown between 36 and 37 degrees C. With human hemoglobin, a structural transition was observed at T (B) as circular dichroism (CD) experiments revealed. This leads to the assumption that a species' body temperature occupies a unique position on the temperature scale and may even be imprinted in the structure of certain proteins. In this study, it was investigated whether hemoglobins of species with a T (B) different from those of human show temperature transitions and whether those were also linked to the species' T (B). The main conclusion was drawn from dynamic light scattering (DLS) and CD experiments. It was observed that such structural temperature transitions did occur in hemoglobins from all studied species and were correlated linearly (slope 0.81, r = 0.95) with the species' body temperature. We presumed that alpha-helices of hemoglobin were able to unfold more readily around T (B). alpha-helical unfolding would initiate molecular aggregation causing RBC passage and viscosity breakdown as mentioned above. Thus, structural molecular changes of hemoglobin could determine biophysical effects visible on a macroscopic scale. It is hypothesized that the species' body temperature was imprinted into the structure of hemoglobins.

  1. Relationship between body temperature and air temperature In ...

    African Journals Online (AJOL)

    1992-06-22

    Jun 22, 1992 ... Body temperatures of singing male Gryllus bimaculatus were measured for the first time. ... this can create special problems for the female, since the ... each male. Each cricket was cooled to 4°C and the thermo- couple was glued to the exoskeleton with cyano-acrylic glue. The thermocouple was connected ...

  2. A hypothalamic circuit that controls body temperature.

    Science.gov (United States)

    Zhao, Zheng-Dong; Yang, Wen Z; Gao, Cuicui; Fu, Xin; Zhang, Wen; Zhou, Qian; Chen, Wanpeng; Ni, Xinyan; Lin, Jun-Kai; Yang, Juan; Xu, Xiao-Hong; Shen, Wei L

    2017-02-21

    The homeostatic control of body temperature is essential for survival in mammals and is known to be regulated in part by temperature-sensitive neurons in the hypothalamus. However, the specific neural pathways and corresponding neural populations have not been fully elucidated. To identify these pathways, we used cFos staining to identify neurons that are activated by a thermal challenge and found induced expression in subsets of neurons within the ventral part of the lateral preoptic nucleus (vLPO) and the dorsal part of the dorsomedial hypothalamus (DMD). Activation of GABAergic neurons in the vLPO using optogenetics reduced body temperature, along with a decrease in physical activity. Optogenetic inhibition of these neurons resulted in fever-level hyperthermia. These GABAergic neurons project from the vLPO to the DMD and optogenetic stimulation of the nerve terminals in the DMD also reduced body temperature and activity. Electrophysiological recording revealed that the vLPO GABAergic neurons suppressed neural activity in DMD neurons, and fiber photometry of calcium transients revealed that DMD neurons were activated by cold. Accordingly, activation of DMD neurons using designer receptors exclusively activated by designer drugs (DREADDs) or optogenetics increased body temperature with a strong increase in energy expenditure and activity. Finally, optogenetic inhibition of DMD neurons triggered hypothermia, similar to stimulation of the GABAergic neurons in the vLPO. Thus, vLPO GABAergic neurons suppressed the thermogenic effect of DMD neurons. In aggregate, our data identify vLPO→DMD neural pathways that reduce core temperature in response to a thermal challenge, and we show that outputs from the DMD can induce activity-induced thermogenesis.

  3. Mindfulness starts with the body: Somatosensory attention and top-down modulation of cortical alpha rhythms in mindfulness meditation

    Directory of Open Access Journals (Sweden)

    Catherine E Kerr

    2013-02-01

    Full Text Available Mindfulness Based Stress Reduction (MBSR and Mindfulness Based Cognitive Therapy (MBCT use a common set of exercises to reduce distress in chronic pain and decrease risk of depression relapse. These standardized mindfulness (ST-Mindfulness practices predominantly require attending to breath and body sensations. Here, we offer a novel view of ST-Mindfulness’s somatic focus as a form of training for optimizing attentional modulation of 7-14 Hz alpha rhythms that play a key role in filtering inputs to primary sensory neocortex and organizing the flow of sensory information. In support of the framework, we describe our previous finding (Kerr et al, 2011 that ST-Mindfulness enhanced attentional regulation of alpha in primary somatosensory cortex (SI. The framework allows us to make several predictions. In chronic pain, we predict somatic attention in ST-Mindfulness de-biases alpha in SI, freeing up pain-focused attentional resources. In depression relapse, we predict ST-Mindfulness’s somatic attention competes with internally focused rumination, as internally focused cognitive processes (e.g., working and short term memory rely on alpha filtering of sensory input. Our computational model (Jones et al, 2009 predicts ST-Mindfulness enhances top-down modulation of alpha by facilitating precise alterations in timing and efficacy of SI thalamocortical inputs. We conclude by considering how the proposed framework aligns with Buddhist teachings that mindfulness starts with mindfulness of the body. Translating this theory into neurophysiology, we hypothesize that with its somatic focus, mindfulness’ top-down alpha rhythm modulation in SI enhances gain control which, in turn, sensitizes practitioners to better detect and regulate when the mind wanders from its somatic focus. This enhanced regulation of somatic mind-wandering may be an early stage of mindfulness training, leading to cognitive regulation and metacognition.

  4. Biological Rhythms in the Skin

    Directory of Open Access Journals (Sweden)

    Mary S. Matsui

    2016-05-01

    Full Text Available Circadian rhythms, ≈24 h oscillations in behavior and physiology, are reflected in all cells of the body and function to optimize cellular functions and meet environmental challenges associated with the solar day. This multi-oscillatory network is entrained by the master pacemaker located in the suprachiasmatic nucleus (SCN of the hypothalamus, which directs an organism’s rhythmic expression of physiological functions and behavior via a hierarchical system. This system has been highly conserved throughout evolution and uses transcriptional–translational autoregulatory loops. This master clock, following environmental cues, regulates an organism’s sleep pattern, body temperature, cardiac activity and blood pressure, hormone secretion, oxygen consumption and metabolic rate. Mammalian peripheral clocks and clock gene expression have recently been discovered and are present in all nucleated cells in our body. Like other essential organ of the body, the skin also has cycles that are informed by this master regulator. In addition, skin cells have peripheral clocks that can function autonomously. First described in 2000 for skin, this review summarizes some important aspects of a rapidly growing body of research in circadian and ultradian (an oscillation that repeats multiple times during a 24 h period cutaneous rhythms, including clock mechanisms, functional manifestations, and stimuli that entrain or disrupt normal cycling. Some specific relationships between disrupted clock signaling and consequences to skin health are discussed in more depth in the other invited articles in this IJMS issue on Sleep, Circadian Rhythm and Skin.

  5. Biological Rhythms in the Skin.

    Science.gov (United States)

    Matsui, Mary S; Pelle, Edward; Dong, Kelly; Pernodet, Nadine

    2016-05-24

    Circadian rhythms, ≈24 h oscillations in behavior and physiology, are reflected in all cells of the body and function to optimize cellular functions and meet environmental challenges associated with the solar day. This multi-oscillatory network is entrained by the master pacemaker located in the suprachiasmatic nucleus (SCN) of the hypothalamus, which directs an organism's rhythmic expression of physiological functions and behavior via a hierarchical system. This system has been highly conserved throughout evolution and uses transcriptional-translational autoregulatory loops. This master clock, following environmental cues, regulates an organism's sleep pattern, body temperature, cardiac activity and blood pressure, hormone secretion, oxygen consumption and metabolic rate. Mammalian peripheral clocks and clock gene expression have recently been discovered and are present in all nucleated cells in our body. Like other essential organ of the body, the skin also has cycles that are informed by this master regulator. In addition, skin cells have peripheral clocks that can function autonomously. First described in 2000 for skin, this review summarizes some important aspects of a rapidly growing body of research in circadian and ultradian (an oscillation that repeats multiple times during a 24 h period) cutaneous rhythms, including clock mechanisms, functional manifestations, and stimuli that entrain or disrupt normal cycling. Some specific relationships between disrupted clock signaling and consequences to skin health are discussed in more depth in the other invited articles in this IJMS issue on Sleep, Circadian Rhythm and Skin.

  6. EFFECTS OF CIRCADIAN RHYTHM ON BALANCE PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Karagul Osman

    2017-09-01

    Full Text Available Introduction. The aim of the study was to examine the effect of circadian rhythm on dynamic balance performance and to determine the role of physical activity level, body temperature, chronotype, and gender in this possible effect. Material and

  7. Circadian Impairment of Distal Skin Temperature Rhythm in Patients With Sleep-Disordered Breathing: The Effect of CPAP.

    Science.gov (United States)

    Martinez-Nicolas, Antonio; Guaita, Marc; Santamaría, Joan; Montserrat, Josep M; Rol, María Ángeles; Madrid, Juan Antonio

    2017-06-01

    Our aim was to evaluate the circadian rhythm of distal skin temperature (DST) in sleep-disordered breathing (SDB), its relation to excessive daytime sleepiness and the effect of continuous positive airway pressure (CPAP) on DST. Eighty SDB patients (53.1 ± 1.2 years old, 27.6% women) and 67 healthy participants (52.3 ± 1.6 years old, 26.9% women) wore a temperature data logger for 1 week. On the last day of that week, SDB patients underwent a polysomnography followed by a Maintenance of Wakefulness Test (MWT), Multiple Sleep Latency Test, and Sustained Attention to Response Task protocol to objectively quantify daytime sleepiness. A subset of 21 moderate to severe SDB patients were treated with CPAP during at least 3 months and revaluated with the same procedure. A nonparametric analysis was performed to characterize DST to assess differences between groups and associations among DST, polysomnography, and daytime sleepiness measures. SDB patients showed an unstable, fragmented, flattened, phase-advanced, and less robust DST rhythm as compared to healthy participants. The more severe the SDB, the worse the DST pattern was, as indicated by the correlation coefficient. Sleepiness, according to MWT sleep latencies, was also associated with the higher fragmentation, lower amplitude, and less robustness of the DST rhythm. Treatment with CPAP improved DST pattern regularity and robustness. DST is altered in SDB, exhibiting a direct relationship to the severity of this condition, and improves with CPAP treatment. DST independently correlates with sleepiness, thus, its measurement may contribute to the understanding of the pathophysiology of sleepiness in these patients. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

  8. Effect of programmed diurnal temperature cycles on plasma thyroxine level, body temperature, and feed intake of holstein dairy cows

    Science.gov (United States)

    Scott, I. M.; Johnson, H. D.; Hahn, G. L.

    1983-03-01

    Holstein cows exposed to simulated summer diurnal ambient temperature cycles of Phoenix, Arizona and Atlanta, Georgia and diurnal modifications of these climates displayed daily cycles fluctuations in plasma thyroxine (T4) and rectal temperatures (Tre). There were daily diurnal changes in T4 and Tre under all simulated climate conditions. Maximal values generally occurred in the evening hours and minimum values in the morning. Although the diurnal rhythm was influenced by the various simulated climates (diurnal modifications) a diurnal rhythm was very evident even under constant conditions at thermoneutral (Tnc) and at cyclic thermoneutral conditions (TN). The major significance of the study is that the initiation of night cooling of the animals at a time when their Tre was highest was most beneficial to maintenance of a TN plasma T4 level. There was a highly significant negative relationship of average T4 and average Tre. There was also a significant negative relationship of feed consumption and average temperature-humidity index (THI). These data suggest that night cooling may be a most effective method to alleviate thermoregulatory limitations of a hot climate on optimal animal performance. Decreasing the night time air temperature (Ta) or THI or increasing the diurnal range allows the cows to more easily dissipate excess body heat accumulated during the day and minimize the thermal inhibition on feed intake, and alterations in plasma T4 and Tre.

  9. Mice Lacking EGR1 Have Impaired Clock Gene (BMAL1) Oscillation, Locomotor Activity, and Body Temperature.

    Science.gov (United States)

    Riedel, Casper Schwartz; Georg, Birgitte; Jørgensen, Henrik L; Hannibal, Jens; Fahrenkrug, Jan

    2018-01-01

    Early growth response transcription factor 1 (EGR1) is expressed in the suprachiasmatic nucleus (SCN) after light stimulation. We used EGR1-deficient mice to address the role of EGR1 in the clock function and light-induced resetting of the clock. The diurnal rhythms of expression of the clock genes BMAL1 and PER1 in the SCN were evaluated by semi-quantitative in situ hybridization. We found no difference in the expression of PER1 mRNA between wildtype and EGR1-deficient mice; however, the daily rhythm of BMAL1 mRNA was completely abolished in the EGR1-deficient mice. In addition, we evaluated the circadian running wheel activity, telemetric locomotor activity, and core body temperature of the mice. Loss of EGR1 neither altered light-induced phase shifts at subjective night nor affected negative masking. Overall, circadian light entrainment was found in EGR1-deficient mice but they displayed a reduced locomotor activity and an altered temperature regulation compared to wild type mice. When placed in running wheels, a subpopulation of EGR1-deficient mice displayed a more disrupted activity rhythm with no measurable endogenous period length (tau). In conclusion, the present study provides the first evidence that the circadian clock in the SCN is disturbed in mice deficient of EGR1.

  10. Circadian rhythms in human performance and mood under constant conditions

    Science.gov (United States)

    Monk, T. H.; Buysse, D. J.; Reynolds, C. F. 3rd; Berga, S. L.; Jarrett, D. B.; Begley, A. E.; Kupfer, D. J.

    1997-01-01

    This study explored the relationship between circadian performance rhythms and rhythms in rectal temperature, plasma cortisol, plasma melatonin, subjective alertness and well-being. Seventeen healthy young adults were studied under 36 h of 'unmasking' conditions (constant wakeful bedrest, temporal isolation, homogenized 'meals') during which rectal temperatures were measured every minute, and plasma cortisol and plasma melatonin measured every 20 min. Hourly subjective ratings of global vigour (alertness) and affect (well-being) were obtained followed by one of two performance batteries. On odd-numbered hours performance (speed and accuracy) of serial search, verbal reasoning and manual dexterity tasks was assessed. On even-numbered hours, performance (% hits, response speed) was measured at a 25-30 min visual vigilance task. Performance of all tasks (except search accuracy) showed a significant time of day variation usually with a nocturnal trough close to the trough in rectal temperature. Performance rhythms appeared not to reliably differ with working memory load. Within subjects, predominantly positive correlations emerged between good performance and higher temperatures and better subjective alertness; predominantly negative correlations between good performance and higher plasma levels of cortisol and melatonin. Temperature and cortisol rhythms correlated with slightly more performance measures (5/7) than did melatonin rhythms (4/7). Global vigour correlated about as well with performance (5/7) as did temperature, and considerably better than global affect (1/7). In conclusion: (1) between-task heterogeneity in circadian performance rhythms appeared to be absent when the sleep/wake cycle was suspended; (2) temperature (positively), cortisol and melatonin (negatively) appeared equally good as circadian correlates of performance, and (3) subjective alertness correlated with performance rhythms as well as (but not better than) body temperature, suggesting that

  11. Impairment of endogenous melatonin rhythm is related to the degree of chronic kidney disease (CREAM study)

    NARCIS (Netherlands)

    Koch, B.C.P.; van der Putten, K.; van Someren, E.J.W.; Wielders, J.P.M.; ter Wee, P.M.; Nagtegaal, J.E.; Gaillard, C.A.J.M.

    2010-01-01

    Background. The nocturnal endogenous melatonin rise, which is associated with the onset of sleep propensity, is absent in haemodialysis patients. Information on melatonin rhythms in chronic kidney disease (CKD) is limited. Clear relationships exist between melatonin, core body temperature and

  12. Circadian Rhythms

    Indian Academy of Sciences (India)

    IAS Admin

    Keywords. Circadian rhythms, biological clocks, geophysical cycles, en- trainment. Living organisms ranging from bacteria to human beings exhibit 24-h rhythms in various behaviours and physiological processes. Matching of the period of such rhythms with that of the daily environmental cycles gives an impression that.

  13. Circadian Rhythms

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 18; Issue 7. Circadian Rhythms - From Daily Rhythms to Biological Clocks. Koustubh M Vaze Vijay Kumar Sharma. Series Article Volume 18 Issue 7 July 2013 pp 662- ... Keywords. Circadian rhythms; biological clocks; geophysical cycles; entrainment.

  14. Energetic consequences of field body temperatures in the green iguana

    NARCIS (Netherlands)

    Lichtenbelt, WDVM; Wesselingh, RA

    We investigated body temperatures of free-ranging green iguanas (Iguana iguana) on Curacao (Netherlands Antilles), and how metabolic costs and benefits of food processing affect body temperatures. Body temperatures of free-living iguanas were measured by radio telemetry. We also used a model, with

  15. Orbital bleeding in rats while under diethylether anaesthesia does not influence telemetrically determined heart rate, body temperature, locomotor and eating activity when compared with anaesthesia alone

    NARCIS (Netherlands)

    vanHerck, H; DeBoer, SF; Hesp, APM; VanLith, HA; Baumans, [No Value; Beynen, AC; Herck, H. van; Lith, H.A. van

    The question addressed was whether orbital bleeding in rats, while under diethylether anaesthesia, affects their locomotor activity, body core temperature, heart rate rhythm and eating pattern. Roman High Avoidance (RHA) and Roman Low Avoidance (RLA) rats were used to enhance generalization of the

  16. Effect of modafinil on plasma melatonin, cortisol and growth hormone rhythms, rectal temperature and performance in healthy subjects during a 36 h sleep deprivation.

    Science.gov (United States)

    Brun, J; Chamba, G; Khalfallah, Y; Girard, P; Boissy, I; Bastuji, H; Sassolas, G; Claustrat, B

    1998-06-01

    Modafinil is an alerting substance which has been used successfully to treat narcolepsy. Nothing is known about its effect on hormone secretions. For this purpose, eight healthy young men were enrolled in a double blind trial to test the effects of modafinil on daily plasma melatonin, cortisol and growth hormone (GH) rhythms. Blood was sampled for hormone assays, every hour during the daytime and every 30 min during the nighttime. In addition, rectal temperature and mental performances were determined during the study which comprised 3 sessions, two weeks apart: a 24 h control session including a night with sleep (S1) and two 48 h sessions S2 and S3 with a sleep-deprived night (N1) followed by a recovery night (N2). Modafinil (300 mg x 2) or placebo were randomly attributed during N1 at 22 h and 8 h. As expected, performance was improved after modafinil administration and body temperature was maintained or increased. Plasma melatonin and cortisol profiles were similar after modafinil and placebo administration. The levels observed during the recovery and the control nights (N2) displayed no difference. For GH, during both sleep deprived nights, secretion was dramatically reduced compared with the control one, although the number of secretory episodes was unchanged. These data show that the alerting property of modafinil is not related to an alteration of hormone profiles and suggest that the acute modafinil administration is devoid of short-term side-effects.

  17. Circalunar Rhythms Induced Changes in the Body Functions and Reproductive Performance in Pregnant Ewes

    International Nuclear Information System (INIS)

    El-Darawany, A.A.; El-Tarabany, A.A.; Teama, F.E.I.

    2014-01-01

    A total number of 136 pregnant ewes with the same age and parity were used in the present study. The experimental ewes reared during Arabic months or lunar months, from the 1st Gomady to Zol-hega, 1432 AH. The available data for each animal were obtained from the records of Sheep Farm, Project of Experimental Farms. Lambing season started at months, Shawal to Zol-hega. After lambing, the ewes were divided into three groups according to moon phases. Ewes in the 1st group laboured in new moon phase period. The ewes in the 2nd and the 3rd groups laboured in full and old moon phases, respectively. The study was conducted to determine the changes in the body functions and reproductive of pregnant ewes due to the effect of lunar cycle which causes the increase of births by up to 72% in the full moon phase. The results showed that, a significant increase in feed and water consumption, the activity of liver enzymes, concentration of cholesterol, triglyceride, kidney functions and also the hormone thyroxine and triiodothyronine was recorded during full moon, on the contrary, there was a significant decrease in the concentration of total protein, albumin, glucose, calcium, phosphorus and cortisol in the blood of pregnant ewes was recorded during full moon phases followed by new and old moon. On the other hand, reproductive traits including litter size at birth and weaning and mortality rate were recorded during different moon phases.

  18. A telemetry study on the chronic effects of microdialyis probe implantation on the activity pattern and temperature rhythm of the rat

    NARCIS (Netherlands)

    Drijfhout, W.J.; Kemper, R.H.A.; Meerlo, P.; Koolhaas, J.M.; Grol, C.J.; Westerink, B.H.C.

    1995-01-01

    The present study describes the effects of implantation of microdialysis probes on temperature and activity rhythms of the rat, measured with a telemetry system. For comparison two widely used types of microdialysis probes were investigated, a transcerebral probe, inserted into the pineal gland and

  19. Impairment of endogenous melatonin rhythm is related to the degree of chronic kidney disease (CREAM study).

    Science.gov (United States)

    Koch, Birgit C P; van der Putten, Karien; Van Someren, Eus J W; Wielders, Jos P M; Ter Wee, Piet M; Nagtegaal, J Elsbeth; Gaillard, Carlo A J M

    2010-02-01

    The nocturnal endogenous melatonin rise, which is associated with the onset of sleep propensity, is absent in haemodialysis patients. Information on melatonin rhythms in chronic kidney disease (CKD) is limited. Clear relationships exist between melatonin, core body temperature and cortisol in healthy subjects. In CKD, no data are available on these relationships. The objective of the study was to characterize the rhythms of melatonin, cortisol and temperature in relation to renal function in patients with CKD. From 28 patients (mean age 71 years) with various degrees of renal function, over a 24-h period, blood samples were collected every 2 h. An intestinal telemetric sensor was used to measure core temperature. The presence of diurnal rhythms was examined for melatonin, temperature and cortisol. Correlation analysis was performed between Cockcroft-Gault GFR (GFR), melatonin, cortisol and temperature parameters. The mean GFR was 57 +/- 30 ml/min. The subjects exhibited melatonin (n = 24) and cortisol (n = 22) rhythms. GFR was significantly correlated to melatonin amplitude (r = 0.59, P = 0.003) and total melatonin production (r = 0.51, P = 0.01), but not to temperature or cortisol rhythms. Interestingly, no associations were found between the rhythms of temperature, melatonin and cortisol. As melatonin amplitude and melatonin rhythm decreased with advancing renal dysfunction, follow-up research into circadian rhythms in patients with CKD is warranted.

  20. Body Temperature Measurements for Metabolic Phenotyping in Mice

    Directory of Open Access Journals (Sweden)

    Carola W. Meyer

    2017-07-01

    Full Text Available Endothermic organisms rely on tightly balanced energy budgets to maintain a regulated body temperature and body mass. Metabolic phenotyping of mice, therefore, often includes the recording of body temperature. Thermometry in mice is conducted at various sites, using various devices and measurement practices, ranging from single-time probing to continuous temperature imaging. Whilst there is broad agreement that body temperature data is of value, procedural considerations of body temperature measurements in the context of metabolic phenotyping are missing. Here, we provide an overview of the various methods currently available for gathering body temperature data from mice. We explore the scope and limitations of thermometry in mice, with the hope of assisting researchers in the selection of appropriate approaches, and conditions, for comprehensive mouse phenotypic analyses.

  1. Body Temperature Measurements for Metabolic Phenotyping in Mice

    Science.gov (United States)

    Meyer, Carola W.; Ootsuka, Youichirou; Romanovsky, Andrej A.

    2017-01-01

    Endothermic organisms rely on tightly balanced energy budgets to maintain a regulated body temperature and body mass. Metabolic phenotyping of mice, therefore, often includes the recording of body temperature. Thermometry in mice is conducted at various sites, using various devices and measurement practices, ranging from single-time probing to continuous temperature imaging. Whilst there is broad agreement that body temperature data is of value, procedural considerations of body temperature measurements in the context of metabolic phenotyping are missing. Here, we provide an overview of the various methods currently available for gathering body temperature data from mice. We explore the scope and limitations of thermometry in mice, with the hope of assisting researchers in the selection of appropriate approaches, and conditions, for comprehensive mouse phenotypic analyses. PMID:28824441

  2. Circadian Rhythms

    Indian Academy of Sciences (India)

    IAS Admin

    rhythms especially their endogenous, self-sustained nature, ability to entrain to environmental cycles and. PRCs, greatly resemble those of self-sustained physical oscillators; which led them to propose that circadian rhythms function like physical oscillators and named such biological oscillators as 'endogenous self- ...

  3. Protein restriction does not affect body temperature pattern in female mice.

    Science.gov (United States)

    Kato, Goro A; Shichijo, Hiroki; Takahashi, Toshihiro; Shinohara, Akio; Morita, Tetsuo; Koshimoto, Chihiro

    2017-10-30

    Daily torpor is a physiological adaptation in mammals and birds characterized by a controlled reduction of metabolic rate and body temperature during the resting phase of circadian rhythms. In laboratory mice, daily torpor is induced by dietary caloric restriction. However, it is not known which nutrients are related to daily torpor expression. To determine whether dietary protein is a key factor in inducing daily torpor in mice, we fed mice a protein-restricted (PR) diet that included only one-quarter of the amount of protein but the same caloric level as a control (C) diet. We assigned six non-pregnant female ICR mice to each group and recorded their body weights and core body temperatures for 4 weeks. Body weights in the C group increased, but those in the PR group remained steady or decreased. Mice in both groups did not show daily torpor, but most mice in a food-restricted group (n=6) supplied with 80% of the calories given to the C group exhibited decreased body weights and frequently displayed daily torpor. This suggests that protein restriction is not a trigger of daily torpor; torpid animals can conserve their internal energy, but torpor may not play a significant role in conserving internal protein. Thus, opportunistic daily torpor in mice may function in energy conservation rather than protein saving.

  4. Relationship between alertness, performance, and body temperature in humans

    Science.gov (United States)

    Wright, Kenneth P Jr; Hull, Joseph T.; Czeisler, Charles A.

    2002-01-01

    Body temperature has been reported to influence human performance. Performance is reported to be better when body temperature is high/near its circadian peak and worse when body temperature is low/near its circadian minimum. We assessed whether this relationship between performance and body temperature reflects the regulation of both the internal biological timekeeping system and/or the influence of body temperature on performance independent of circadian phase. Fourteen subjects participated in a forced desynchrony protocol allowing assessment of the relationship between body temperature and performance while controlling for circadian phase and hours awake. Most neurobehavioral measures varied as a function of internal biological time and duration of wakefulness. A number of performance measures were better when body temperature was elevated, including working memory, subjective alertness, visual attention, and the slowest 10% of reaction times. These findings demonstrate that an increased body temperature, associated with and independent of internal biological time, is correlated with improved performance and alertness. These results support the hypothesis that body temperature modulates neurobehavioral function in humans.

  5. Assessment of the use of temperature-sensitive microchips to determine core body temperature in goats.

    Science.gov (United States)

    Torrao, N A; Hetem, R S; Meyer, L C R; Fick, L G

    2011-03-26

    Body temperature was measured at five different body sites (retroperitoneum, groin, semimembranosus muscle, flank and shoulder) using temperature-sensitive microchips implanted in five female goats, and compared with the core body and rectal temperatures. Body temperature was measured while the goats were kept in different ambient temperatures, with and without radiant heat, as well as during a fever induced experimentally by injection of bacterial lipopolysaccharide. Bland-Altman limit of agreement analysis was used to compare the temperature measurements at the different body sites during the different interventions. Temperatures measured by the microchip implanted in the retroperitoneum showed the closest agreement (mean 0.2 °C lower) with core and rectal temperatures during all interventions, whereas temperatures measured by the microchips implanted in the groin, muscle, flank and shoulder differed from core body temperature by up to 3.5 °C during the various interventions.

  6. Body/bone-marrow differential-temperature sensor

    Science.gov (United States)

    Anselmo, V. J.; Berdahl, C. M.

    1978-01-01

    Differential-temperature sensor developed to compare bone-marrow and body temperature in leukemia patients uses single stable amplifier to monitor temperature difference recorded by thermocouples. Errors are reduced by referencing temperatures to each other, not to separate calibration points.

  7. Effect of irrigation fluid temperature on body temperature during ...

    African Journals Online (AJOL)

    ... of dogs were hypothermic (<37oC). The addition of warmed irrigation fluids to a temperature management protocol in dogs undergoing elbow arthroscopy during general anaesthesia did not lead to decreased temperature losses. Keywords: Arthroscopy, Hypothermia, Irrigation fluid temperature, Thermoregulation.

  8. Surgical implantation of temperature-sensitive transmitters and data-loggers to record body temperature in koalas (Phascolarctos cinereus).

    Science.gov (United States)

    Adam, D; Johnston, S D; Beard, L; Nicholson, V; Lisle, A; Gaughan, J; Larkin, R; Theilemann, P; Mckinnon, A; Ellis, W

    2016-01-01

    Under predicted climate change scenarios, koala distribution in Australia is expected to be adversely affected. Recent studies have attempted to identify suitable habitat, based on models of bioclimatic regions, but to more accurately reflect the thermal tolerance and behavioural adaptations of the various regional populations, the koala's response to periods of heat stress will need to be investigated at the individual animal level. To explore the safety and suitability of temperature-sensitive intra-abdominal implants for monitoring core body temperature in the koala. A temperature-sensitive radio transmitter and thermal iButton data-logger, waxed together as a package, were surgically implanted into the abdominal cavity of four captive koalas. In one animal the implant was tethered and in the other three, it was left free-floating. After 3 months, the implants were removed and all four koalas recovered without complications. The tethering of the package in the one koala resulted in minor inflammation and adhesion, so this practice was subsequently abandoned. The free-floating deployments were complication-free and revealed a diurnal body temperature rhythm, with daily ranges of 0.4-2.8°C. The minimum recorded body temperature was 34.2°C and the maximum was 37.7°C. The difference in the readings obtained from the transmitters and iButtons never exceeded 0.3°C. The suitability of the surgical approach was confirmed, from both the animal welfare and data collection points of view. © 2016 Australian Veterinary Association.

  9. The influence of body temperature on sprint speed and anti ...

    African Journals Online (AJOL)

    ... increases as body temperature is further reduced. This monitor lives in the savanna regions of northern Nigeria where the vegetation is low and hiding places are rare. The lizard might have evolved this antipredatory mechanism at low body temperatures as its last resort to survive since there is no place to take refuge in a ...

  10. Microchip-based body temperature measurements in pigs

    DEFF Research Database (Denmark)

    Nielsen, Jens; Lohse, Louise

    In the present study, we tested whether an electronic identification and body temperature monitorring technology presently applied in small experimental animals could be transferred for use in pigs.......In the present study, we tested whether an electronic identification and body temperature monitorring technology presently applied in small experimental animals could be transferred for use in pigs....

  11. Miniature ingestible telemeter devices to measure deep-body temperature

    Science.gov (United States)

    Pope, J. M.; Fryer, T. B. (Inventor)

    1976-01-01

    A telemetry device comprised of a pill-size ingestible transmitter developed to obtain deep body temperature measurements of a human is described. The device has particular utility in the medical field where deep body temperatures provide an indication of general health.

  12. Air temperature investigation in microenvironment around a human body

    DEFF Research Database (Denmark)

    Licina, Dusan; Melikov, Arsen Krikor; Sekhar, Chandra

    2015-01-01

    The aim of this study is to investigate the temperature boundary layer around a human body in a quiescent indoor environment. The air temperature, mean in time and standard deviation of the temperature fluctuations around a breathing thermal manikin are examined in relation to the room temperature......, body posture and human respiratory flow. To determine to what extent the experiments represent the realistic scenario, the additional experiments were performed with a real human subject. The results show that at a lower room air temperature (20°C), the fluctuations of air temperature increased close...... to the surface of the body. The large standard deviation of air temperature fluctuations, up to 1.2°C, was recorded in the region of the chest, and up to 2.9°C when the exhalation was applied. The manikin leaned backwards increased the air temperature in the breathing zone, which was opposite from the forward...

  13. Protein-energy malnutrition induces an aberrant acute-phase response and modifies the circadian rhythm of core temperature.

    Science.gov (United States)

    Smith, Shari E; Ramos, Rafaela Andrade; Refinetti, Roberto; Farthing, Jonathan P; Paterson, Phyllis G

    2013-08-01

    Protein-energy malnutrition (PEM), present in 12%-19% of stroke patients upon hospital admission, appears to be a detrimental comorbidity factor that impairs functional outcome, but the mechanisms are not fully elucidated. Because ischemic brain injury is highly temperature-sensitive, the objectives of this study were to investigate whether PEM causes sustained changes in temperature that are associated with an inflammatory response. Activity levels were recorded as a possible explanation for the immediate elevation in temperature upon introduction to a low protein diet. Male, Sprague-Dawley rats (7 weeks old) were fed a control diet (18% protein) or a low protein diet (PEM, 2% protein) for either 7 or 28 days. Continuous core temperature recordings from bioelectrical sensor transmitters demonstrated a rapid increase in temperature amplitude, sustained over 28 days, in response to a low protein diet. Daily mean temperature rose transiently by day 2 (p = 0.01), falling to normal by day 4 (p = 0.08), after which mean temperature continually declined as malnutrition progressed. There were no alterations in activity mean (p = 0.3) or amplitude (p = 0.2) that were associated with the early rise in mean temperature. Increased serum alpha-2-macroglobulin (p protein diet had no effect on the signaling pathway of the pro-inflammatory transcription factor, NFκB, in the hippocampus. In conclusion, PEM induces an aberrant and sustained acute-phase response coupled with long-lasting effects on body temperature.

  14. Circadian Rhythms

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 18; Issue 11. Circadian Rhythms - Circadian Timing Systems: How are they Organized? Koustubh M Vaze Vijay Kumar Sharma. Series Article Volume 18 Issue 11 November 2013 pp 1032-1050 ...

  15. Body Temperature Cycles Control Rhythmic Alternative Splicing in Mammals.

    Science.gov (United States)

    Preußner, Marco; Goldammer, Gesine; Neumann, Alexander; Haltenhof, Tom; Rautenstrauch, Pia; Müller-McNicoll, Michaela; Heyd, Florian

    2017-08-03

    The core body temperature of all mammals oscillates with the time of the day. However, direct molecular consequences of small, physiological changes in body temperature remain largely elusive. Here we show that body temperature cycles drive rhythmic SR protein phosphorylation to control an alternative splicing (AS) program. A temperature change of 1°C is sufficient to induce a concerted splicing switch in a large group of functionally related genes, rendering this splicing-based thermometer much more sensitive than previously described temperature-sensing mechanisms. AS of two exons in the 5' UTR of the TATA-box binding protein (Tbp) highlights the general impact of this mechanism, as it results in rhythmic TBP protein levels with implications for global gene expression in vivo. Together our data establish body temperature-driven AS as a core clock-independent oscillator in mammalian peripheral clocks. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Mapping the body surface temperature of cattle by infrared thermography.

    Science.gov (United States)

    Salles, Marcia Saladini Vieira; da Silva, Suelen Corrêa; Salles, Fernando André; Roma, Luiz Carlos; El Faro, Lenira; Bustos Mac Lean, Priscilla Ayleen; Lins de Oliveira, Celso Eduardo; Martello, Luciane Silva

    2016-12-01

    Infrared thermography (IRT) is an alternative non-invasive method that has been studied as a tool for identifying many physiological and pathological processes related to changes in body temperature. The objective of the present study was to evaluate the body surface temperature of Jersey dairy cattle in a thermoneutral environment in order to contribute to the determination of a body surface temperature pattern for animals of this breed in a situation of thermal comfort. Twenty-four Jersey heifers were used over a period of 35 days at APTA Brazil. Measurements were performed on all animals, starting with the physiological parameters. Body surface temperature was measured by IRT collecting images in different body regions: left and right eye area, right and left eye, caudal left foreleg, cranial left foreleg, right and left flank, and forehead. High correlations were observed between temperature and humidity index (THI) and right flank, left flank and forehead temperatures (0.85, 0.81, and 0.81, respectively). The IRT variables that exhibited the five highest correlation coefficients in principal component 1 were, in decreasing order: forehead (0.90), right flank (0.87), left flank (0.84), marker 1 caudal left foreleg (0.83), marker 2 caudal left foreleg (0.74). The THI showed a high correlation coefficient (0.88) and moderate to low correlations were observed for the physiological variables rectal temperature (0.43), and respiratory frequency (0.42). The thermal profile obtained indicates a surface temperature pattern for each region studied in a situation of thermal comfort and may contribute to studies investigating body surface temperature. Among the body regions studied, IRT forehead temperature showed the highest association with rectal temperature, and forehead and right and left flank temperatures are strongly associated with THI and may be adopted in future studies on thermoregulation and body heat production. Copyright © 2016 Elsevier Ltd. All rights

  17. Implanted telemeter for electrocardiogram and body temperature

    Science.gov (United States)

    Barrows, W. F.

    1972-01-01

    Measuring system requiring one blocking oscillator to generate modulated pulse repetition rate is implantable in the bodies of small animals. Device has life of two years and transmission range of about three feet. EKG sensing unit also is used to sense electromyogram or electrooculogram of laboratory animals.

  18. Patterns of Body Temperature During Feeding in Rats Under Varying Ambient Temperatures

    NARCIS (Netherlands)

    de Vries, Jan; Strubbe, Jan H.; Wildering, Wic C.; Gorter, Jan A.; Prins, Ab J.A.

    Relationships between feeding and body temperature of rats were investigated at three ambient temperatures during the whole light/dark cycle. Basal liver temperature was negatively correlated with ambient temperature. Only at 29-degrees-C liver temperature indicated activation of autonomic and

  19. Neurotropin®inhibits calpain activity upregulated by specific alternation of rhythm in temperature in the mesencephalon of rats.

    Science.gov (United States)

    Fujisawa, Hiroki; Numazawa, Takumi; Kawamura, Minoru; Naiki, Mitsuru

    2017-02-15

    Neurotropin® (NTP), an analgesic for chronic pain, has antihyperalgesic effects in specific alternation of rhythm in temperature (SART)-stressed rats. Previous studies have shown that SART stress induces hyperalgesia, as well as post-translational modification of proteins (including substrates for calpain, a calcium-dependent cysteine protease) in the mesencephalon of rats. To better understand the mechanism of action of NTP, we investigated whether SART stress activates calpain in the mesencephalon of rats and whether NTP inhibits this activation. Wistar rats were exposed to SART stress for 5days. NTP (200NU/kg/day) was administered intraperitoneally every day from the onset of SART stress. The mechanical pain threshold was measured using the Randall-Selitto test on the 6th day. Thereafter, the rat mesencephalon was immediately collected and calpain activity was examined using western blot analysis with a calpain cleavage site-specific antibody. SART stress induced hyperalgesia and increased the calpain activity in the mesencephalon of rats. In contrast, NTP treatment attenuated the hyperalgesia and prevented the increase in calpain activity in the mesencephalon of SART-stressed rats. Interestingly, a negative correlation was identified between calpain activity and mechanical pain threshold in SART-stressed rats treated with or without NTP. Furthermore, NTP inhibited calpain activity on mammalian uncoordinated-18 in rat mesencephalon homogenate and Ac-LLY-AFC as substrates in an in vitro cell-free system. Our data demonstrate that NTP treatment prevents SART stress-induced calpain activation in the mesencephalon of rats and suggests that NTP-mediated antihyperalgesia is associated with an inhibition of calpain activity in the mesencephalon. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Sleep, circadian rhythms, and athletic performance.

    Science.gov (United States)

    Thun, Eirunn; Bjorvatn, Bjørn; Flo, Elisabeth; Harris, Anette; Pallesen, Ståle

    2015-10-01

    Sleep deprivation and time of day are both known to influence performance. A growing body of research has focused on how sleep and circadian rhythms impact athletic performance. This review provides a systematic overview of this research. We searched three different databases for articles on these issues and inspected relevant reference lists. In all, 113 articles met our inclusion criteria. The most robust result is that athletic performance seems to be best in the evening around the time when the core body temperature typically is at its peak. Sleep deprivation was negatively associated with performance whereas sleep extension seems to improve performance. The effects of desynchronization of circadian rhythms depend on the local time at which performance occurs. The review includes a discussion of differences regarding types of skills involved as well as methodological issues. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Body temperature stability achieved by the large body mass of sea turtles.

    Science.gov (United States)

    Sato, Katsufumi

    2014-10-15

    To investigate the thermal characteristics of large reptiles living in water, temperature data were continuously recorded from 16 free-ranging loggerhead turtles, Caretta caretta, during internesting periods using data loggers. Core body temperatures were 0.7-1.7°C higher than ambient water temperatures and were kept relatively constant. Unsteady numerical simulations using a spherical thermodynamic model provided mechanistic explanations for these phenomena, and the body temperature responses to fluctuating water temperature can be simply explained by a large body mass with a constant thermal diffusivity and a heat production rate rather than physiological thermoregulation. By contrast, body temperatures increased 2.6-5.1°C in 107-152 min during their emergences to nest on land. The estimated heat production rates on land were 7.4-10.5 times the calculated values in the sea. The theoretical prediction that temperature difference between body and water temperatures would increase according to the body size was confirmed by empirical data recorded from several species of sea turtles. Comparing previously reported data, the internesting intervals of leatherback, green and loggerhead turtles were shorter when the body temperatures were higher. Sea turtles seem to benefit from a passive thermoregulatory strategy, which depends primarily on the physical attributes of their large body masses. © 2014. Published by The Company of Biologists Ltd.

  2. Circadian variation of EEG power spectra in NREM and REM sleep in humans: dissociation from body temperature

    Science.gov (United States)

    Dijk, D. J.

    1999-01-01

    In humans, EEG power spectra in REM and NREM sleep, as well as characteristics of sleep spindles such as their duration, amplitude, frequency and incidence, vary with circadian phase. Recently it has been hypothesized that circadian variations in EEG spectra in humans are caused by variations in brain or body temperature and may not represent phenomena relevant to sleep regulatory processes. To test this directly, a further analysis of EEG power spectra - collected in a forced desynchrony protocol in which sleep episodes were scheduled to a 28-h period while the rhythms of body temperature and plasma melatonin were oscillating at their near 24-h period - was carried out. EEG power spectra were computed for NREM and REM sleep occurring between 90-120 and 270-300 degrees of the circadian melatonin rhythm, i.e. just after the clearance of melatonin from plasma in the 'morning' and just after the 'evening' increase in melatonin secretion. Average body temperatures during scheduled sleep at these two circadian phases were identical (36.72 degrees C). Despite identical body temperatures, the power spectra in NREM sleep were very different at these two circadian phases. EEG activity in the low frequency spindle range was significantly and markedly enhanced after the evening increase in plasma melatonin as compared to the morning phase. For REM sleep, significant differences in power spectra during these two circadian phases, in particular in the alpha range, were also observed. The results confirm that EEG power spectra in NREM and REM sleep vary with circadian phase, suggesting that the direct contribution of temperature to the circadian variation in EEG power spectra is absent or only minor, and are at variance with the hypothesis that circadian variations in EEG power spectra are caused by variations in temperature.

  3. A nonintrusive temperature measuring system for estimating deep body temperature in bed.

    Science.gov (United States)

    Sim, S Y; Lee, W K; Baek, H J; Park, K S

    2012-01-01

    Deep body temperature is an important indicator that reflects human being's overall physiological states. Existing deep body temperature monitoring systems are too invasive to apply to awake patients for a long time. Therefore, we proposed a nonintrusive deep body temperature measuring system. To estimate deep body temperature nonintrusively, a dual-heat-flux probe and double-sensor probes were embedded in a neck pillow. When a patient uses the neck pillow to rest, the deep body temperature can be assessed using one of the thermometer probes embedded in the neck pillow. We could estimate deep body temperature in 3 different sleep positions. Also, to reduce the initial response time of dual-heat-flux thermometer which measures body temperature in supine position, we employed the curve-fitting method to one subject. And thereby, we could obtain the deep body temperature in a minute. This result shows the possibility that the system can be used as practical temperature monitoring system with appropriate curve-fitting model. In the next study, we would try to establish a general fitting model that can be applied to all of the subjects. In addition, we are planning to extract meaningful health information such as sleep structure analysis from deep body temperature data which are acquired from this system.

  4. Target temperature management of 33°C and 36°C in patients with out-of-hospital cardiac arrest with initial non-shockable rhythm

    DEFF Research Database (Denmark)

    Frydland, Martin; Kjaergaard, Jesper; Erlinge, David

    2015-01-01

    PURPOSE: Despite a lack of randomized trials in comatose survivors of out-of-hospital cardiac arrest (OHCA) with an initial non-shockable rhythm (NSR), guidelines recommend induced hypothermia to be considered in these patients. We assessed the effect on outcome of two levels of induced hypothermia...... in comatose patient resuscitated from NSR. METHODS: Hundred and seventy-eight patients out of 950 in the TTM trial with an initial NSR were randomly assigned to targeted temperature management at either 33°C (TTM33, n=96) or 36°C (TTM36, n=82). We assessed mortality, neurologic function (Cerebral Performance...... Score (CPC) and modified Rankin Scale (mRS)), and organ dysfunction (Sequential Organ Failure Assessment (SOFA) score). RESULTS: Patients with NSR were older, had longer time to ROSC, less frequently had bystander CPR and had higher lactate levels at admission compared to patients with shockable rhythm...

  5. Twenty-four-hour rhythms in relation to the natural photoperiod: a field study in humans.

    Science.gov (United States)

    Laakso, M L; Porkka-Heiskanen, T; Alila, A; Stenberg, D; Johansson, G

    1994-01-01

    The daily rhythms of salivary melatonin, salivary cortisol, and axillary body temperature were measured in nine healthy volunteers in midsummer, around the autumn equinox, and in midwinter, at a latitude of 60 degrees N. The aim was to find out whether these rhythms were dependent on variations of the natural daylength. The samples were collected every 2 hr during 24-hr periods in everyday conditions. The individual rhythms were characterized with the acrophase estimates of the best-fitting cosine curve models and with the half-rise and half-decline times calculated from the raw data. The melatonin and cortisol rhythms were delayed significantly (about 1 hr) in midwinter as compared with summer and autumn. The most advanced rhythms were found in autumn. The shifts of the melatonin and cortisol rhythms could be explained as a result of the changes of natural illumination. The overt temperature rhythms did not differ significantly among the sampling months. The lack of seasonal patterns in temperature rhythms probably primarily reflected the socially determined rest-activity cycles of the subjects.

  6. Daily rhythm of cerebral blood flow velocity

    Directory of Open Access Journals (Sweden)

    Spielman Arthur J

    2005-03-01

    Full Text Available Abstract Background CBFV (cerebral blood flow velocity is lower in the morning than in the afternoon and evening. Two hypotheses have been proposed to explain the time of day changes in CBFV: 1 CBFV changes are due to sleep-associated processes or 2 time of day changes in CBFV are due to an endogenous circadian rhythm independent of sleep. The aim of this study was to examine CBFV over 30 hours of sustained wakefulness to determine whether CBFV exhibits fluctuations associated with time of day. Methods Eleven subjects underwent a modified constant routine protocol. CBFV from the middle cerebral artery was monitored by chronic recording of Transcranial Doppler (TCD ultrasonography. Other variables included core body temperature (CBT, end-tidal carbon dioxide (EtCO2, blood pressure, and heart rate. Salivary dim light melatonin onset (DLMO served as a measure of endogenous circadian phase position. Results A non-linear multiple regression, cosine fit analysis revealed that both the CBT and CBFV rhythm fit a 24 hour rhythm (R2 = 0.62 and R2 = 0.68, respectively. Circadian phase position of CBT occurred at 6:05 am while CBFV occurred at 12:02 pm, revealing a six hour, or 90 degree difference between these two rhythms (t = 4.9, df = 10, p Conclusion In conclusion, time of day variations in CBFV have an approximately 24 hour rhythm under constant conditions, suggesting regulation by a circadian oscillator. The 90 degree-phase angle difference between the CBT and CBFV rhythms may help explain previous findings of lower CBFV values in the morning. The phase difference occurs at a time period during which cognitive performance decrements have been observed and when both cardiovascular and cerebrovascular events occur more frequently. The mechanisms underlying this phase angle difference require further exploration.

  7. Body mass modulates huddling dynamics and body temperature profiles in rabbit pups.

    Science.gov (United States)

    Bautista, Amando; Zepeda, José Alfredo; Reyes-Meza, Verónica; Féron, Christophe; Rödel, Heiko G; Hudson, Robyn

    2017-10-01

    Altricial mammals typically lack the physiological capacity to thermoregulate independently during the early postnatal period, and in litter-bearing species the young benefit strongly from huddling together with their litter siblings. Such litter huddles are highly dynamic systems, often characterized by competition for energetically favorable, central positions. In the present study, carried out in domestic rabbits Oryctolagus cuniculus, we asked whether individual differences in body mass affect changes in body temperature during changes in the position within the huddle. We predicted that pups with relatively lower body mass should be more affected by such changes arising from huddle dynamics in comparison to heavier ones. Changes in pups' maximum body surface temperature (determined by infrared thermography) were significantly affected by changes in the number of their neighbors in the litter huddle, and indeed these temperature changes largely depended on the pups' body mass relative to their litter siblings. Lighter pups showed significant increases in their maximum body surface temperature when their number of huddling partners increased by one or two siblings whereas pups with intermediate or heavier body mass did not show such significant increases in maximum body temperature when experiencing such changes. A similar pattern was found with respect to average body surface temperature. This strong link between changes in the number of huddling partners and body surface temperature in lighter pups might, on the one hand, arise from a higher vulnerability of such pups due to their less favorable body surface area-to-volume ratio. On the other hand, as lighter pups generally had fewer neighbors than heavier ones and thus typically a comparatively smaller body surface in contact with siblings, they potentially had more to gain from increasing their number of neighbors. The present findings might help to understand how individual differences in body mass within a

  8. The Effects of the Heat and Moisture Exchanger on Humidity, Airway Temperature, and Core Body Temperature

    National Research Council Canada - National Science Library

    Delventhal, Mary

    1999-01-01

    Findings from several studies have demonstrated that the use of a heat and moisture exchanger increases airway humidity, which in turn increases mean airway temperature and prevents decreases in core body temperature...

  9. Hypercoagulability in response to elevated body temperature and central hypovolemia

    DEFF Research Database (Denmark)

    Meyer, Martin; Ostrowski, Sisse R; Overgaard, Flemming Anders

    2013-01-01

    Coagulation abnormalities contribute to poor outcomes in critically ill patients. In trauma patients exposed to a hot environment, a systemic inflammatory response syndrome, elevated body temperature, and reduced central blood volume occur in parallel with changes in hemostasis and endothelial...... damage. The objective of this study was to evaluate whether experimentally elevated body temperature and reduced central blood volume (CBV) per se affects hemostasis and endothelial activation....

  10. Elevated body temperature in ischemic stroke associated with neurological improvement.

    Science.gov (United States)

    Khanevski, A N; Naess, H; Thomassen, L; Waje-Andreassen, U; Nacu, A; Kvistad, C E

    2017-11-01

    Some studies suggest that high body temperature within the first few hours of ischemic stroke onset is associated with improved outcome. We hypothesized an association between high body temperature on admission and detectable improvement within 6-9 hours of stroke onset. Consecutive ischemic stroke patients with NIHSS scores obtained within 3 hours and in the interval 6-9 hours after stroke onset were included. Body temperature was measured on admission. A total of 315 patients with ischemic stroke were included. Median NIHSS score on admission was 6. Linear regression showed that NIHSS score 6-9 hours after stroke onset was inversely associated with body temperature on admission after adjusting for confounders including NIHSS score body temperature and neurological improvement within few hours after admission. This finding may be limited to patients with documented proximal middle cerebral artery occlusion on admission and suggests a beneficial effect of higher body temperature on clot lysis within the first three hours. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. The pupal body temperature and inner space temperature of cocoon under microwave irradiation

    International Nuclear Information System (INIS)

    Kagawa, T.

    1996-01-01

    The temperature of pupal surface,body and inner space of cocoon on cocoon drying of microwave irradiation was investigated to make clear the effect of temperature with pupa and cocoon shell. After pupal surface temperature and body temperature were risen rapidly in early irradiation and slowly thereafter, these were done fast again. Then these rising degrees fell. The variation of inner space temperature consists three terms: as the first stage of rapidly rising on early irradiation, the second stage of slowly doing and the third stage of fast doing again in temperature. In the first stage and the second stage, the higher the temperature of sending air during irradiation was, the shorter the term was and the higher the reached temperature was. The surface, pupal body and inner space have reached higher temperature than the sending air before cocoon drying was over

  12. Metabolic rate and body temperature of an African sun bird ...

    African Journals Online (AJOL)

    The oxygen consumption (VO2) of the lesser double-collared sunbird, Nectarinia chalybea, was measured at ambient temperatures (Ta) from 7 to 35°C. The diel variation in body temperature (Tb) and wet thermal conductance (C) was also determined. The sunbirds (mean mass 8.36 g ± S.E. 0.21 g) showed a pronounced ...

  13. Diagnostic accuracy of routine postoperative body temperature measurements

    NARCIS (Netherlands)

    Vermeulen, Hester; Storm-Versloot, Marja N.; Goossens, Astrid; Speelman, Peter; Legemate, Dink A.

    2005-01-01

    BACKGROUND: On surgical wards, body temperature is routinely measured, but there is no proof that this is useful for detecting postoperative infection. The aim of this study was to compare temperature measurements (the test) with the confirmed absence or presence of a postoperative infection (the

  14. Body temperature of the loggerhead sea turtle Caretta caretta and ...

    African Journals Online (AJOL)

    Lepidochelys olivacea L respectively, after emerging from water of 27,SoC to nest. (Mrosovsky &. Pritchard 1971). Smaller but significant temperature differentials have been reported for green and hawksbill turtles by Hirth (1962). Records of body temperatures of free-ranging animals are scarce; the only record being.

  15. Estimation of temperature change in human body using MRI

    International Nuclear Information System (INIS)

    Nikawa, Yoshio; Nakamura, Suguru

    2016-01-01

    In the field of traditional oriental medicine, two types of treatment style, which are an acupuncture treatment and a moxibustion treatment have been performed. These treatments are used and effected by doctor or acupuncturist in their clinic or hospital and are widely spread. In spite of such a general treatment, it is not deeply discussed about mechanism of heat transfer modality and about temperature distribution in the treatment of moxibustion. Also, it is not discussed about temperature distribution deep inside human tissue during acupuncture treatment. It comes from the difficulty of noninvasive measurement of temperature deep inside human body. In this study, a temperature distribution for acupuncture and moxibustion treatment is measured and analyzed using thermograph and MRI by measuring the phase of longitudinal relaxation time of protons. The experimental results of measured temperature distribution under the human legs have been demonstrated. The result of temperature analysis in the human body is also reported. (author)

  16. Circadian Rhythms

    Indian Academy of Sciences (India)

    IAS Admin

    We all experience robust cycles of light and darkness, occurring as a consequence of continuous rotation of the earth about its axis and we call such a twenty-four hour cycle, 'a day'. Almost all living beings are exposed to such daily environmental cycles and they too exhibit daily rhythms in various biological processes.

  17. Circadian Rhythms

    Indian Academy of Sciences (India)

    IAS Admin

    internal/physiological (endogenous) mechanism that drives them? Such questions have intrigued scientists for several decades and paved the way for the exploration of biological timing systems and their underlying mechanisms. Research on a wide variety of organisms has established that these rhythms are generated by.

  18. Circadian Rhythms

    Indian Academy of Sciences (India)

    IAS Admin

    significance. (right) Vijay Kumar Sharma is a Professor at the. Evolutionary and. Organismal Biology Unit,. JNCASR, Bangalore. His major research interests presently are in understand- ing circadian organization of fruit flies and ants, adaptive significance of circadian clocks, neurogenetics of circadian egg-laying rhythm.

  19. Circadian Rhythms

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 2. Circadian Rhythms: Why do Living Organisms Have Them? Koustubh M Vaze K L Nikhil Vijay Kumar Sharma. Series Article Volume 19 Issue 2 February 2014 pp 175-189 ...

  20. Assessment of body surface temperature in cetaceans: an iterative approach

    Directory of Open Access Journals (Sweden)

    R. G. Silva

    Full Text Available Heat transfer from skin surface to ambient water is probably the most important aspect of thermal balance in marine mammals, but the respective calculations depend on knowing the surface temperature (T S, the direct measurement of which in free animals is very difficult. An indirect iterative method is proposed for T S prediction in free cetaceans from deep body temperature, swimming speed, and temperature and thermodynamic properties of the water.

  1. Patterns of activity and body temperature of Aldabra giant tortoises in relation to environmental temperature.

    Science.gov (United States)

    Falcón, Wilfredo; Baxter, Rich P; Furrer, Samuel; Bauert, Martin; Hatt, Jean-Michel; Schaepman-Strub, Gabriela; Ozgul, Arpat; Bunbury, Nancy; Clauss, Marcus; Hansen, Dennis M

    2018-02-01

    We studied the temperature relations of wild and zoo Aldabra giant tortoises ( Aldabrachelys gigantea ) focusing on (1) the relationship between environmental temperature and tortoise activity patterns ( n  = 8 wild individuals) and (2) on tortoise body temperature fluctuations, including how their core and external body temperatures vary in relation to different environmental temperature ranges (seasons; n  = 4 wild and n  = 5 zoo individuals). In addition, we surveyed the literature to review the effect of body mass on core body temperature range in relation to environmental temperature in the Testudinidae. Diurnal activity of tortoises was bimodally distributed and influenced by environmental temperature and season. The mean air temperature at which activity is maximized was 27.9°C, with a range of 25.8-31.7°C. Furthermore, air temperature explained changes in the core body temperature better than did mass, and only during the coldest trial, did tortoises with higher mass show more stable temperatures. Our results, together with the overall Testudinidae overview, suggest that, once variation in environmental temperature has been taken into account, there is little effect of mass on the temperature stability of tortoises. Moreover, the presence of thermal inertia in an individual tortoise depends on the environmental temperatures, and we found no evidence for inertial homeothermy. Finally, patterns of core and external body temperatures in comparison with environmental temperatures suggest that Aldabra giant tortoises act as mixed conformer-regulators. Our study provides a baseline to manage the thermal environment of wild and rewilded populations of an important island ecosystem engineer species in an era of climate change.

  2. Effects of MDMA on body temperature in humans

    Science.gov (United States)

    Liechti, Matthias E

    2014-01-01

    Hyperthermia is a severe complication associated with the recreational use of 3,4-methylenedioxymethamphetamine (MDMA, Ecstasy). In this review, the clinical laboratory studies that tested the effects of MDMA on body temperature are summarized. The mechanisms that underlie the hyperthermic effects of MDMA in humans and treatment of severe hyperthermia are presented. The data show that MDMA produces an acute and dose-dependent rise in core body temperature in healthy subjects. The increase in body temperature is in the range of 0.2-0.8°C and does not result in hyperpyrexia (>40°C) in a controlled laboratory setting. However, moderately hyperthermic body temperatures >38.0°C occur frequently at higher doses, even in the absence of physical activity and at room temperature. MDMA primarily releases serotonin and norepinephrine. Mechanistic clinical studies indicate that the MDMA-induced elevations in body temperature in humans partially depend on the MDMA-induced release of norepinephrine and involve enhanced metabolic heat generation and cutaneous vasoconstriction, resulting in impaired heat dissipation. The mediating role of serotonin is unclear. The management of sympathomimetic toxicity and associated hyperthermia mainly includes sedation with benzodiazepines and intravenous fluid replacement. Severe hyperthermia should primarily be treated with additional cooling and mechanical ventilation. PMID:27626046

  3. Full body illusion is associated with widespread skin temperature reduction

    Directory of Open Access Journals (Sweden)

    Roy eSalomon

    2013-07-01

    Full Text Available A central feature of our consciousness is the experience of the self as a unified entity residing in a physical body, termed bodily self-consciousness. This phenomenon includes aspects such as the sense of owning a body (also known as body ownership and has been suggested to arise from the integration of sensory and motor signals from the body. Several studies have shown that temporally synchronous tactile stimulation of the real body and visual stimulation of a fake or virtual body can induce changes in bodily self-consciousness, typically resulting in a sense of illusory ownership over the fake body. The present study assessed the effect of anatomical congruency of visuo-tactile stimulation on bodily self-consciousness. A virtual body was presented and temporally synchronous visuo-tactile stroking was applied simultaneously the participants’ body and to the virtual body. We manipulated the anatomical locations of the visuo-tactile stroking (i.e. on the back, on the leg, resulting in congruent stroking (stroking was felt and seen on the back or the leg or incongruent stroking (i.e. stroking was felt on the leg and seen on the back. We measured self-identification with the virtual body and self-location as well as skin temperature. Illusory self-identification with the avatar as well as changes in self-localization were experienced in the congruent stroking conditions. Participants showed a decrease in skin temperature across several body locations during congruent stimulation. These data establish that the full-body illusion alters bodily self-consciousness and instigates widespread physiological changes in the participant’s body.

  4. Wall temperature control of low-speed body drag

    Science.gov (United States)

    Lin, J. C.; Ash, R. L.

    1986-01-01

    The use of thermal means to control drag under turbulent boundary layer conditions is examined. Numerical calculations are presented for both skin friction and (unseparated) pressure drag for turbulent boundary-layer flows over a fuselage-like body with wall heat transfer. In addition, thermal control of separation on a bluff body is investigated. It is shown that a total drag reduction of up to 20 percent can be achieved for wall heating with a wall-to-total-freestream temperature ratio of 2. For streamlined slender bodies, partial wall heating of the forebody can produce almost the same order of total drag reduction as the full body heating case. For bluff bodies, the separation delay from partial wall cooling of the afterbody is approximately the same as for the fully cooled body.

  5. Core body temperature control by total liquid ventilation using a virtual lung temperature sensor.

    Science.gov (United States)

    Nadeau, Mathieu; Micheau, Philippe; Robert, Raymond; Avoine, Olivier; Tissier, Renaud; Germim, Pamela Samanta; Vandamme, Jonathan; Praud, Jean-Paul; Walti, Herve

    2014-12-01

    In total liquid ventilation (TLV), the lungs are filled with a breathable liquid perfluorocarbon (PFC) while a liquid ventilator ensures proper gas exchange by renewal of a tidal volume of oxygenated and temperature-controlled PFC. Given the rapid changes in core body temperature generated by TLV using the lung has a heat exchanger, it is crucial to have accurate and reliable core body temperature monitoring and control. This study presents the design of a virtual lung temperature sensor to control core temperature. In the first step, the virtual sensor, using expired PFC to estimate lung temperature noninvasively, was validated both in vitro and in vivo. The virtual lung temperature was then used to rapidly and automatically control core temperature. Experimentations were performed using the Inolivent-5.0 liquid ventilator with a feedback controller to modulate inspired PFC temperature thereby controlling lung temperature. The in vivo experimental protocol was conducted on seven newborn lambs instrumented with temperature sensors at the femoral artery, pulmonary artery, oesophagus, right ear drum, and rectum. After stabilization in conventional mechanical ventilation, TLV was initiated with fast hypothermia induction, followed by slow posthypothermic rewarming for 1 h, then by fast rewarming to normothermia and finally a second fast hypothermia induction phase. Results showed that the virtual lung temperature was able to provide an accurate estimation of systemic arterial temperature. Results also demonstrate that TLV can precisely control core body temperature and can be favorably compared to extracorporeal circulation in terms of speed.

  6. The impact of morning light intensity and environmental temperature on body temperatures and alertness.

    Science.gov (United States)

    Te Kulve, Marije; Schlangen, Luc J M; Schellen, Lisje; Frijns, Arjan J H; van Marken Lichtenbelt, Wouter D

    2017-06-01

    Indoor temperature and light exposure are known to affect body temperature, productivity and alertness of building occupants. However, not much is known about the interaction between light and temperature exposure and the relationship between morning light induced alertness and its effect on body temperature. Light intensity and room temperature during morning office hours were investigated under strictly controlled conditions. In a randomized crossover study, two white light conditions (4000K, either bright 1200lx or dim 5lx) under three different room temperatures (26, 29 and 32°C) were investigated. A lower room temperature increased the core body temperature (CBT) and lowered skin temperature and the distal-proximal temperature gradient (DPG). Moreover, a lower room temperature reduced the subjective sleepiness and reaction time on an auditory psychomotor vigilance task (PVT), irrespective of the light condition. Interestingly, the morning bright light exposure did affect thermophysiological parameters, i.e. it decreased plasma cortisol, CBT and proximal skin temperature and increased the DPG, irrespective of the room temperature. During the bright light session, subjective sleepiness decreased irrespective of the room temperature. However, the change in sleepiness due to the light exposure was not related to these physiological changes. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Circadian rhythms of women with fibromyalgia

    Science.gov (United States)

    Klerman, E. B.; Goldenberg, D. L.; Brown, E. N.; Maliszewski, A. M.; Adler, G. K.

    2001-01-01

    Fibromyalgia syndrome is a chronic and debilitating disorder characterized by widespread nonarticular musculoskeletal pain whose etiology is unknown. Many of the symptoms of this syndrome, including difficulty sleeping, fatigue, malaise, myalgias, gastrointestinal complaints, and decreased cognitive function, are similar to those observed in individuals whose circadian pacemaker is abnormally aligned with their sleep-wake schedule or with local environmental time. Abnormalities in melatonin and cortisol, two hormones whose secretion is strongly influenced by the circadian pacemaker, have been reported in women with fibromyalgia. We studied the circadian rhythms of 10 women with fibromyalgia and 12 control healthy women. The protocol controlled factors known to affect markers of the circadian system, including light levels, posture, sleep-wake state, meals, and activity. The timing of the events in the protocol were calculated relative to the habitual sleep-wake schedule of each individual subject. Under these conditions, we found no significant difference between the women with fibromyalgia and control women in the circadian amplitude or phase of rhythms of melatonin, cortisol, and core body temperature. The average circadian phases expressed in hours posthabitual bedtime for women with and without fibromyalgia were 3:43 +/- 0:19 and 3:46 +/- 0:13, respectively, for melatonin; 10:13 +/- 0:23 and 10:32 +/- 0:20, respectively for cortisol; and 5:19 +/- 0:19 and 4:57 +/- 0:33, respectively, for core body temperature phases. Both groups of women had similar circadian rhythms in self-reported alertness. Although pain and stiffness were significantly increased in women with fibromyalgia compared with healthy women, there were no circadian rhythms in either parameter. We suggest that abnormalities in circadian rhythmicity are not a primary cause of fibromyalgia or its symptoms.

  8. Regulation of body temperature by some Mesozoic marine reptiles.

    Science.gov (United States)

    Bernard, Aurélien; Lécuyer, Christophe; Vincent, Peggy; Amiot, Romain; Bardet, Nathalie; Buffetaut, Eric; Cuny, Gilles; Fourel, François; Martineau, François; Mazin, Jean-Michel; Prieur, Abel

    2010-06-11

    What the body temperature and thermoregulation processes of extinct vertebrates were are central questions for understanding their ecology and evolution. The thermophysiologic status of the great marine reptiles is still unknown, even though some studies have suggested that thermoregulation may have contributed to their exceptional evolutionary success as apex predators of Mesozoic aquatic ecosystems. We tested the thermal status of ichthyosaurs, plesiosaurs, and mosasaurs by comparing the oxygen isotope compositions of their tooth phosphate to those of coexisting fish. Data distribution reveals that these large marine reptiles were able to maintain a constant and high body temperature in oceanic environments ranging from tropical to cold temperate. Their estimated body temperatures, in the range from 35 degrees +/- 2 degrees C to 39 degrees +/- 2 degrees C, suggest high metabolic rates required for predation and fast swimming over large distances offshore.

  9. Circadian variability of body temperature responses to methamphetamine.

    Science.gov (United States)

    Behrouzvaziri, Abolhassan; Zaretskaia, Maria V; Rusyniak, Daniel E; Zaretsky, Dmitry V; Molkov, Yaroslav I

    2018-01-01

    Vital parameters of living organisms exhibit circadian rhythmicity. Although rats are nocturnal animals, most of the studies involving rats are performed during the day. The objective of this study was to examine the circadian variability of the body temperature responses to methamphetamine. Body temperature was recorded in male Sprague-Dawley rats that received intraperitoneal injections of methamphetamine (Meth, 1 or 5 mg/kg) or saline at 10 AM or at 10 PM. The baseline body temperature at night was 0.8°C higher than during the day. Both during the day and at night, 1 mg/kg of Meth induced monophasic hyperthermia. However, the maximal temperature increase at night was 50% smaller than during the daytime. Injection of 5 mg/kg of Meth during the daytime caused a delayed hyperthermic response. In contrast, the same dose at night produced responses with a tendency toward a decrease of body temperature. Using mathematical modeling, we previously showed that the complex dose dependence of the daytime temperature responses to Meth results from an interplay between inhibitory and excitatory drives. In this study, using our model, we explain the suppression of the hyperthermia in response to Meth at night. First, we found that the baseline activity of the excitatory drive is greater at night. It appears partially saturated and thus is additionally activated by Meth to a lesser extent. Therefore, the excitatory component causes less hyperthermia or becomes overpowered by the inhibitory drive in response to the higher dose. Second, at night the injection of Meth results in reduction of the equilibrium body temperature, leading to gradual cooling counteracting hyperthermia.

  10. Circadian rhythms in Macaca mulatta monkeys during Bion 11 flight

    Science.gov (United States)

    Alpatov, A. M.; Hoban-Higgins, T. M.; Klimovitsky, V. Y.; Tumurova, E. G.; Fuller, C. A.

    2000-01-01

    Circadian rhythms of primate brain temperature, head and ankle skin temperature, motor activity, and heart rate were studied during spaceflight and on the ground. In space, the circadian rhythms of all the parameters were synchronized with diurnal Zeitgebers. However, in space the brain temperature rhythm showed a significantly more delayed phase angle, which may be ascribed to an increase of the endogenous circadian period.

  11. Responses of antennal campaniform sensilla to rapid temperature changes in ground beetles of the tribe platynini with different habitat preferences and daily activity rhythms.

    Science.gov (United States)

    Must, Anne; Merivee, Enno; Luik, Anne; Mänd, Marika; Heidemaa, Mikk

    2006-05-01

    Responses of temperature sensitive (cold) cells from the antenna of ground beetles (tribe Platynini) were compared in species with different ecological preferences and daily activity rhythms. Action potential rates were characterized at various temperatures (ranges 23-39 degrees C) and during rapid changes in it (Deltat=0.5-15 degrees C). The stationary firing frequencies were nearly twice as high in eurythermic open field ground beetles Agonum muelleri and Anchomenus dorsalis (firing rates ranging from 22 to 47imp/s) than in a stenothermic forest species Platynus assimilis. In the eurythermic species, the firing rate did not significantly depend on temperature (Anchomenus dorsalis range of 23-27 degrees C and Agonum muelleri range of 23-33 degrees C) but plots of firing rate versus temperature showed rapid declines when lethally high temperatures were approached. In contrast, a nearly linear decline of the firing rate/temperature curve was observed in Platynus assimilis. Responses to rapid temperature decreases were also considerably higher in eurythermic species. Both the peak frequency of the initial burst (maximum 420-650Hz) as well as the sustained discharge in the first 4s of the response were higher than in Platynus assimilis. Long silent periods, lasting up to several seconds, that occurred at the beginning of the response to rapid warming were significantly shorter in Agonum muelleri and Anchomenus dorsalis compared to Platynus assimilis. These findings suggest that the responses of thermoreceptors to temperature changes may be correlated with specific ecological preferences.

  12. Decreases in body temperature and body mass constitute pre-hibernation remodelling in the Syrian golden hamster, a facultative mammalian hibernator

    Science.gov (United States)

    Chayama, Yuichi; Ando, Lisa; Tamura, Yutaka; Miura, Masayuki

    2016-01-01

    Hibernation is an adaptive strategy for surviving during periods with little or no food availability, by profoundly reducing the metabolic rate and the core body temperature (Tb). Obligate hibernators (e.g. bears, ground squirrels, etc.) hibernate every winter under the strict regulation of endogenous circannual rhythms, and they are assumed to undergo adaptive remodelling in autumn, the pre-hibernation period, prior to hibernation. However, little is known about the nature of pre-hibernation remodelling. Syrian hamsters (Mesocricetus auratus) are facultative hibernators that can hibernate irrespective of seasons when exposed to prolonged short photoperiod and cold ambient temperature (SD-Cold) conditions. Their Tb set point reduced by the first deep torpor (DT) and then increased gradually after repeated cycles of DT and periodic arousal (PA), and finally recovered to the level observed before the prolonged SD-Cold in the post-hibernation period. We also found that, before the initiation of hibernation, the body mass of animals decreased below a threshold, indicating that hibernation in this species depends on body condition. These observations suggest that Syrian hamsters undergo pre-hibernation remodelling and that Tb and body mass can be useful physiological markers to monitor the remodelling process during the pre-hibernation period. PMID:27152216

  13. Body lengths and temperatures of the crabeater seal Lobodon ...

    African Journals Online (AJOL)

    BODY LENGTHS AND TEMPERATURES OF THE CRABEA'I..ER SEAL. LOBO DON CARCINOPHAGUS. I. A. I. NEL. Department of Zoology, University of Pretoria. The following data were collected en route to the South African National Antarctic Expedition base (S.A.N.A.E.) in Queen Maud Land, Antarctica, during the early ...

  14. Environmental stressors during space flight: potential effects on body temperature

    Science.gov (United States)

    Jauchem, J. R.

    1988-01-01

    1. Organisms may be affected by many environmental factors during space flight, e.g., acceleration, weightlessness, decreased pressure, changes in oxygen tension, radiofrequency radiation and vibration. 2. Previous studies of change in body temperature--one response to these environmental factors--are reviewed. 3. Conditions leading to heat stress and hypothermia are discussed.

  15. [Biological rhythms for anaesthesia and intensive care].

    Science.gov (United States)

    Dispersyn, G; Chassard, D; Pain, L

    2010-06-01

    Knowledge of biological rhythms has led to better understanding of the time-of-day dependent effects of anaesthetic drugs. These chronopharmacological effects are currently explained by the biological rhythms modulating the pharmacokinetic, toxic and pharmacodynamic parameters of these substances. Such effect has been described for general anesthetics, local anaesthetics, analgesics as well as for antibiotics. But recent data also highlight that general anaesthetics, probably part of their brain effects, also alter the regulation of biological rhythms, including the sleep-wake or the endogenous circadian temperature rhythms. This desynchronization of biological rhythms can led to disturbance of the circadian secretion of many substances, including hormones. Finally, biological rhythms have been also described with regard to physiology of pain and cardiovascular physiopathology. The concept of biological rhythm should be present in mind not only for the clinical management of patients but also for setting studies in the field of anaesthesia, pain and intensive care. 2010. Published by Elsevier SAS.

  16. Diet-independent remodeling of cellular membranes precedes seasonally changing body temperature in a hibernator.

    Directory of Open Access Journals (Sweden)

    Walter Arnold

    Full Text Available Polyunsaturated fatty acids (PUFA have a multitude of health effects. Their incorporation into membrane phospholipids (PL is generally believed to depend directly on dietary influx. PL influence transmembrane protein activity and thus can compensate temperature effects; e.g. PL n-6 PUFA are thought to stabilize heart function at low body temperature (T(b, whereas long chain (>C18 n-3 PUFA may boost oxidative capacity. We found substantial remodeling of membranes in free-living alpine marmots which was largely independent of direct dietary supply. Organ PL n-6 PUFA and n-6 to n-3 ratios were highest at onset and end of hibernation after rapid increases during a brief transitional period prior to hibernation. In contrast, longer chain PL n-3 PUFA content was low at end of summer but maximal at end of hibernation. After termination of hibernation in spring, these changes in PL composition were rapidly reversed. Our results demonstrate selective trafficking of PUFA within the body, probably governed by a circannual endogenous rhythm, as hibernating marmots were in winter burrows isolated for seven months from food and external cues signaling the approaching spring. High concentrations of PL n-6 PUFA throughout hibernation are in line with their hypothesized function of boosting SERCA 2a activity at low T(b. Furthermore, we found increasing rate of rewarming from torpor during winter indicating increasing oxidative capacity that could be explained by the accumulation of long-chain PL n-3 PUFA. It may serve to minimize the time necessary for rewarming despite the increasing temperature range to be covered, because rewarming is a period of highest metabolic rate and hence production of reactive oxygen species. Considering the importance of PUFA for health our results may have important biomedical implications, as seasonal changes of T(b and associated remodeling of membranes are not restricted to hibernators but presumably common among endothermic

  17. Heat Shock Factor 1 Deficiency Affects Systemic Body Temperature Regulation.

    Science.gov (United States)

    Ingenwerth, Marc; Noichl, Erik; Stahr, Anna; Korf, Horst-Werner; Reinke, Hans; von Gall, Charlotte

    2016-01-01

    Heat shock factor 1 (HSF1) is a ubiquitous heat-sensitive transcription factor that mediates heat shock protein transcription in response to cellular stress, such as increased temperature, in order to protect the organism against misfolded proteins. In this study, we analysed the effect of HSF1 deficiency on core body temperature regulation. Body temperature, locomotor activity, and food consumption of wild-type mice and HSF1-deficient mice were recorded. Prolactin and thyroid-stimulating hormone levels were measured by ELISA. Gene expression in brown adipose tissue was analysed by quantitative real-time PCR. Hypothalamic HSF1 and its co-localisation with tyrosine hydroxylase was analysed using confocal laser scanning microscopy. HSF1-deficient mice showed an increase in core body temperature (hyperthermia), decreased overall locomotor activity, and decreased levels of prolactin in pituitary and blood plasma reminiscent of cold adaptation. HSF1 could be detected in various hypothalamic regions involved in temperature regulation, suggesting a potential role of HSF1 in hypothalamic thermoregulation. Moreover, HSF1 co-localises with tyrosine hydroxylase, the rate-limiting enzyme in dopamine synthesis, suggesting a potential role of HSF1 in the hypothalamic control of prolactin release. In brown adipose tissue, levels of prolactin receptor and uncoupled protein 1 were increased in HSF1-deficient mice, consistent with an up-regulation of heat production. Our data suggest a role of HSF1 in systemic thermoregulation. © 2015 S. Karger AG, Basel.

  18. Human biological rhythm in traditional Chinese medicine

    Directory of Open Access Journals (Sweden)

    Tianxing Zhang

    2016-10-01

    Full Text Available Traditional Chinese medicine (TCM has a comprehensive and thorough understanding of biological rhythm. Biological rhythm is an inherent connotation of “harmony between human and nature”, one of the thoughts in TCM. TCM discusses emphatically circadian rhythm, syzygial rhythm and seasonal rhythm, and particularly circadian and seasonal rhythms. Theories of Yin Yang and Five Elements are the principles and methods, with which TCM understands biological rhythms. Based on theories in TCM, biological rhythm in essence is a continuous variation of the human body state synchronized with natural rhythms, and theories of Yin Yang and Five Elements are both language tools to describe this continuous variation and theoretical tools for its investigation and application. The understandings of biological rhythm in TCM can be applied to etiology, health care, disease control and treatment. Many understandings in TCM have been confirmed by modern research and clinical reports, but there are still some pending issues. TCM is distinguished for its holistic viewpoint on biological rhythms.

  19. Implantable microchip transponders for body temperature measurements in pigs

    DEFF Research Database (Denmark)

    Lohse, Louise; Uttenthal, Åse; Enøe, Claes

    body temperature was tested, in order to evaluate the utility and reliability of this tool, in domestic pigs. The system is presently used and well optimized in small laboratory animals [1, 2]. We tested the microchip transponders during experimental infection of pigs with classical swine fever virus...... (CSFV), a viral infection, which can cause high fever in infected animals. Materials and Methods Implantable, programmable temperature transponders (IPTT-300TM) from Bio Medic Data System (Plexx, the Netherlands), designed for non-surgical implantation into animals, was tested in 30 weaner pigs. One...... methods showed that the peripheral subcutaneous body temperature recorded by a microchip transponder may be interesting as a monitoring tool in the clinical surveillance of the health status of domestic pigs. This technology has not at present the power to monitor individually sick pigs, where accurate...

  20. Impact of nesting material on mouse body temperature and physiology.

    Science.gov (United States)

    Gaskill, Brianna N; Gordon, Christopher J; Pajor, Edmond A; Lucas, Jeffrey R; Davis, Jerry K; Garner, Joseph P

    2013-02-17

    In laboratories, mice are housed at 20-24 °C, which is below their lower critical temperature (≈30 °C). Thus, mice are potentially cold stressed, which can alter metabolism, immune function, and reproduction. These physiological changes reflect impaired wellbeing, and affect scientific outcomes. We hypothesized that nesting material would allow mice to alleviate cold stress by controlling their thermal microenvironment, thus insulating them, reducing heat loss and thermogenic processes. Naïve C57BL/6, CD-1, and BALB/c mice (24 male and 24 female/strain in groups of 3) were housed in standard cages at 20 °C either with or without 8 g nesting material for 4 weeks. Core body temperature was followed using intraperitoneal radio telemetry. The thermal properties of the nests were assessed using a thermal imaging camera, and related to nest quality. Higher scoring nests were negatively correlated with the mean radiated temperature and were thus more insulating. No effects of nesting material on body temperature were found. CD-1 mice with nesting material had higher end body weights than controls. No effect was seen in the other two strains. Mice with the telemetry implant had larger spleens than controls, possibly indicating an immune response to the implant or low level infection from the surgery. BALB/c mice express less mRNA for the UCP1 protein than mice without nesting material. This indicates that BALB/c's with nesting material do not utilize their brown fat to create heat as readily as controls. Nests can alleviate thermal discomfort by decreasing the amount of radiated heat and reduce the need for non-shivering thermogenesis. However, different strains appear to use different behavioral (through different primary modes of behavioral thermoregulation) and physiological strategies (utilizing thermogenesis to different degrees) to maintain a constant body temperature under cool standard laboratory ambient temperatures. Copyright © 2013 Elsevier Inc. All

  1. Temperature dependence of three-body ion-molecule reactions

    International Nuclear Information System (INIS)

    Boehringer, H.; Arnold, F.

    1983-01-01

    The temperature dependence of the ion-molecule association reactions (i) N 2 + + N 2 + M → N 4 + + M (M=N 2 , He), (ii) O 2 + + O 2 + M → O 4 + + M (M=O 2 , He) and (iii) He + + 2He → He 2 + + He have been studied over an extended temperature range to temperatures as low as 30K with a recently constructed liquid helium-cooled ion drift tube. Over most of the temperature range the threebody reaction rate coefficients show an inverse temperature dependence proportional to Tsup(-n) with n in the range 0.6 to 2.9. This temperature dependence is quite consistent with current theories of ion molecule association. At low temperatures, however, a deviation from the Tsup(-n) dependence was observed for the association reactions (ii). For reactions (i) different temperature dependences were obtained for N 2 and He third bodies indicating an additional temperature dependence of the collisional stabilisation process. (Authors)

  2. Validation of temperature-sensitive radio transmitters for measurement of body temperature in small animals

    NARCIS (Netherlands)

    Williams, Joseph B.; Tieleman, B. I.; Shobrak, Mohammed

    2009-01-01

    As part of a study on the core body temperature (T(b)) of desert birds, we purposed to use temperature-sensitive implantable radio transmitters. Because of the difficulty in recapturing these birds, we needed to know if these electronic devices held their calibration over the duration of normal

  3. Is Oral Temperature an Accurate Measurement of Deep Body Temperature? A Systematic Review

    Science.gov (United States)

    Mazerolle, Stephanie M.; Ganio, Matthew S.; Casa, Douglas J.; Vingren, Jakob; Klau, Jennifer

    2011-01-01

    Context: Oral temperature might not be a valid method to assess core body temperature. However, many clinicians, including athletic trainers, use it rather than criterion standard methods, such as rectal thermometry. Objective: To critically evaluate original research addressing the validity of using oral temperature as a measurement of core body temperature during periods of rest and changing core temperature. Data Sources: In July 2010, we searched the electronic databases PubMed, Scopus, Cumulative Index to Nursing and Allied Health Literature (CINAHL), SPORTDiscus, Academic Search Premier, and the Cochrane Library for the following concepts: core body temperature, oral, and thermometers. Controlled vocabulary was used, when available, as well as key words and variations of those key words. The search was limited to articles focusing on temperature readings and studies involving human participants. Data Synthesis: Original research was reviewed using the Physiotherapy Evidence Database (PEDro). Sixteen studies met the inclusion criteria and subsequently were evaluated by 2 independent reviewers. All 16 were included in the review because they met the minimal PEDro score of 4 points (of 10 possible points), with all but 2 scoring 5 points. A critical review of these studies indicated a disparity between oral and criterion standard temperature methods (eg, rectal and esophageal) specifically as the temperature increased. The difference was −0.50°C ± 0.31°C at rest and −0.58°C ± 0.75°C during a nonsteady state. Conclusions: Evidence suggests that, regardless of whether the assessment is recorded at rest or during periods of changing core temperature, oral temperature is an unsuitable diagnostic tool for determining body temperature because many measures demonstrated differences greater than the predetermined validity threshold of 0.27°C (0.5°F). In addition, the differences were greatest at the highest rectal temperatures. Oral temperature cannot

  4. Warm Body Temperature Facilitates Energy Efficient Cortical Action Potentials

    Science.gov (United States)

    Yu, Yuguo; Hill, Adam P.; McCormick, David A.

    2012-01-01

    The energy efficiency of neural signal transmission is important not only as a limiting factor in brain architecture, but it also influences the interpretation of functional brain imaging signals. Action potential generation in mammalian, versus invertebrate, axons is remarkably energy efficient. Here we demonstrate that this increase in energy efficiency is due largely to a warmer body temperature. Increases in temperature result in an exponential increase in energy efficiency for single action potentials by increasing the rate of Na+ channel inactivation, resulting in a marked reduction in overlap of the inward Na+, and outward K+, currents and a shortening of action potential duration. This increase in single spike efficiency is, however, counterbalanced by a temperature-dependent decrease in the amplitude and duration of the spike afterhyperpolarization, resulting in a nonlinear increase in the spike firing rate, particularly at temperatures above approximately 35°C. Interestingly, the total energy cost, as measured by the multiplication of total Na+ entry per spike and average firing rate in response to a constant input, reaches a global minimum between 37–42°C. Our results indicate that increases in temperature result in an unexpected increase in energy efficiency, especially near normal body temperature, thus allowing the brain to utilize an energy efficient neural code. PMID:22511855

  5. Feeding period restriction alters the expression of peripheral circadian rhythm genes without changing body weight in mice.

    Directory of Open Access Journals (Sweden)

    Hagoon Jang

    Full Text Available Accumulating evidence suggests that the circadian clock is closely associated with metabolic regulation. However, whether an impaired circadian clock is a direct cause of metabolic dysregulation such as body weight gain is not clearly understood. In this study, we demonstrate that body weight gain in mice is not significantly changed by restricting feeding period to daytime or nighttime. The expression of peripheral circadian clock genes was altered by feeding period restriction, while the expression of light-regulated hypothalamic circadian clock genes was unaffected by either a normal chow diet (NCD or a high-fat diet (HFD. In the liver, the expression pattern of circadian clock genes, including Bmal1, Clock, and Per2, was changed by different feeding period restrictions. Moreover, the expression of lipogenic genes, gluconeogenic genes, and fatty acid oxidation-related genes in the liver was also altered by feeding period restriction. Given that feeding period restriction does not affect body weight gain with a NCD or HFD, it is likely that the amount of food consumed might be a crucial factor in determining body weight. Collectively, these data suggest that feeding period restriction modulates the expression of peripheral circadian clock genes, which is uncoupled from light-sensitive hypothalamic circadian clock genes.

  6. Seasonal variability and influence of outdoor temperature on body temperature of cardiac arrest victims.

    Science.gov (United States)

    Stratil, Peter; Wallmueller, Christian; Schober, Andreas; Stoeckl, Mathias; Hoerburger, David; Weiser, Christoph; Testori, Christoph; Krizanac, Danica; Spiel, Alexander; Uray, Thomas; Sterz, Fritz; Haugk, Moritz

    2013-05-01

    Mild therapeutic hypothermia is a major advance in post-resuscitation-care. Some questions remain unclear regarding the time to initiate cooling and the time to achieve target temperature below 34 °C. We examined whether seasonal variability of outside temperature influences the body temperature of cardiac arrest victims, and if this might have an effect on outcome. Patients with witnessed out-of-hospital cardiac arrests were enrolled retrospectively. Temperature variables from 4 climatic stations in Vienna were provided from the Central Institute for Meteorology and Geodynamics. Depending on the outside temperature at the scene the study participants were assigned to a seasonal group. To compare the seasonal groups a Student's t-test or Mann-Whitney U test was performed as appropriate. Of 134 patients, 61 suffered their cardiac arrest during winter, with an outside temperature below 10 °C; in 39 patients the event occurred during summer, with an outside temperature above 20 °C. Comparing the tympanic temperature recorded at hospital admission, the median of 36 °C (IQR 35.3-36.3) during summer differed significantly to winter with a median of 34.9 °C (IQR 34-35.6) (ptemperature had no impact on the time-to-target-temperature, survival rate or neurologic recovery. The seasonal variability of outside temperature influences body temperature of out-of-hospital cardiac arrest victims. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  7. Whole-body cryostimulation increases parasympathetic outflow and decreases core body temperature.

    Science.gov (United States)

    Zalewski, Pawel; Bitner, Anna; Słomko, Joanna; Szrajda, Justyna; Klawe, Jacek J; Tafil-Klawe, Malgorzata; Newton, Julia L

    2014-10-01

    The cardiovascular, autonomic and thermal response to whole-body cryostimulation exposure are not completely known. Thus the aim of this study was to evaluate objectively and noninvasively autonomic and thermal reactions observed after short exposure to very low temperatures. We examined 25 healthy men with mean age 30.1 ± 3.7 years and comparable anthropomorphical characteristic. Each subject was exposed to cryotherapeutic temperatures in a cryogenic chamber for 3 min (approx. -120 °C). The cardiovascular and autonomic parameters were measured noninvasively with Task Force Monitor. The changes in core body temperature were determined with the Vital Sense telemetric measurement system. Results show that 3 min to cryotherapeutic temperatures causes significant changes in autonomic balance which are induced by peripheral and central blood volume changes. Cryostimulation also induced changes in core body temperature, maximum drop of core temperature was observed 50-60 min after the stimulation. Autonomic and thermal reactions to cryostimulation were observed up to 6 h after the exposure and were not harmful for examined subjects. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Black-body anomaly: analysis of temperature offsets

    International Nuclear Information System (INIS)

    Szopa, M.; Hofmann, R.; Schwarz, M.; Giacosa, F.

    2008-01-01

    Based on the postulate that photon propagation is governed by a dynamically broken SU(2) gauge symmetry (scale ∝10 -4 eV) we make predictions for temperature offsets due to a low-temperature (a few times the present CMB temperature) spectral anomaly at low frequencies. Temperature offsets are extracted from least-square fits of the anomalous black-body spectra to their conventional counterparts. We discuss statistical errors, compare our results with those obtained from calibration data of the FIRAS instrument, and point out that our predicted offsets are screened by experimental errors given the frequency range used by FIRAS to perform their spectral fits. We also make contact with the WMAP observation by blueshifting their frequency bands. Although our results hint towards a strong dynamical component in the CMB dipole and an explanation of low-l suppression, it is important in view of its particle-physics implications that the above postulate be verified/falsified by an independent low-temperature black-body precision experiment. (orig.)

  9. Black Body Detector Temperature from Gall and Planck Perspectives

    Science.gov (United States)

    Gall, Clarence A.

    2009-05-01

    The laws of Gall (http://sites.google.com/site/purefieldphysics) and Planck are generally defined with zero intensity at 0 K. However actual measurements involve detectors above absolute zero. These detectors must also be treated as approximate black body radiators. The zero intensity reference point is thus defined by the radiated intensity at the detector temperature. Planck's law thus becomes ( IP=c1λ^51e^c2λT;-1-c1λ^51e^c2λTd;-1) where Td is the detector temperature. Provided that T>Td;;;IP;is;always>0. Thus from a Planck perspective, wavelength increase should not be a factor in defining detector temperature. The corresponding expression for Gall's law is ( IG=σT^6b^2λe^-λTb-σTd^6b^2λe^-λTdb) . Above the crossover wavelength (http://absimage.aps.org/image/MWSMAR09-2008-000004.pdf), even though T>Td;;;IG<0. From a Gall perspective, this sets a limit on the long wavelength range for a given detector temperature. Longer wavelength measurements require lower detector temperatures. For a 6000 K black body radiator, the long wavelength crossover limits for detectors at 300 K, 100 K and 4 K are 9.138, 12.066 and 21.206 microns respectively.

  10. Clock-dependent and system-driven oscillators interact in the suprachiasmatic nuclei to pace mammalian circadian rhythms.

    Directory of Open Access Journals (Sweden)

    Karine Abitbol

    Full Text Available Circadian clocks drive biological rhythms with a period of approximately 24 hours and keep in time with the outside world through daily resetting by environmental cues. While this external entrainment has been extensively investigated in the suprachiasmatic nuclei (SCN, the role of internal systemic rhythms, including daily fluctuations in core temperature or circulating hormones remains debated. Here, we show that lactating mice, which exhibit dampened systemic rhythms, possess normal molecular clockwork but impaired rhythms in both heat shock response gene expression and electrophysiological output in their SCN. This suggests that body rhythms regulate SCN activity downstream of the clock. Mathematical modeling predicts that systemic feedback upon the SCN functions as an internal oscillator that accounts for in vivo and ex vivo observations. Thus we are able to propose a new bottom-up hierarchical organization of circadian timekeeping in mammals, based on the interaction in the SCN between clock-dependent and system-driven oscillators.

  11. Influence of photoperiod and running wheel access on the entrainment of split circadian rhythms in hamsters

    Directory of Open Access Journals (Sweden)

    Elliott Jeffrey A

    2005-06-01

    Full Text Available Abstract Background In the laboratory, behavioral and physiological states of nocturnal rodents alternate, with a period near 24 h, between those appropriate for the night (e.g., elevated wheel-running activity and high melatonin secretion and for the day (e.g., rest and low melatonin secretion. Under appropriate 24 h light:dark:light:dark conditions, however, rodents may be readily induced to express bimodal rest/activity cycles that reflect a global temporal reorganization of the central neural pacemaker in the hypothalamus. We examine here how the relative length of the light and dark phases of the environmental cycle influences this rhythm splitting and the necessity of a running wheel for expression of this entrainment condition. Results Rhythm splitting was observed in wheel-running and general locomotion of Siberian and Syrian hamsters. The latter also manifest split rhythms in body temperature. Access to a running wheel was necessary neither for the induction nor maintenance of this entrainment pattern. While rhythms were only transiently split in many animals with two 5 h nights, the incidence of splitting was greater with twice daily nights of shorter duration. Removal of running wheels altered the body temperature rhythm but did not eliminate its clear bimodality. Conclusion The expression of entrained, split circadian rhythms exhibits no strict dependence on access to a running wheel, but can be facilitated by manipulation of ambient lighting conditions. These circadian entrainment patterns may be of therapeutic value to human shift-workers and others facing chronobiological challenges.

  12. Early changes of cortical blood flow, brain temperature and electrical activity after whole-body irradiation of the monkey (Macaca fascicularis) (dose range: 3-20 Gy)

    International Nuclear Information System (INIS)

    Court, L.; Gourmelon, P.; Mestries, J.C.

    1987-02-01

    A polyparametric investigation was carried out on 31 monkeys chronically wearing bioinstrumentation allowing to get and process simultaneously local brain blood flow, cerebral temperature, and energies in various frequency bands of the brain electrical activity. This method, which supplied data during several consecutive days, made it possible to study both the biological rhythms at the level of the various parameters, and their fast variations. The effects of whole-body gamma or neutron-gamma irradiation were studied in the 3-20 Gy dose range. Immediate changes after exposure demonstrated different radiosensitivities at the level of the rhythms of the various parameters, and/or their recovery, as well as dose-effect relationships [fr

  13. The effect of anesthesia on body temperature control.

    Science.gov (United States)

    Lenhardt, Rainer

    2010-06-01

    The human thermoregulatory system usually maintains core body temperature near 37 degrees C. This homeostasis is accomplished by thermoregulatory defense mechanisms such as vasoconstriction and shivering or sweating and vasodilatation. Thermoregulation is impaired during general anesthesia. Suppression of thermoregulatory defense mechanisms during general anesthesia is dose dependant and mostly results in perioperative hypothermia. Several adverse effects of hypothermia have been identified, including an increase in postoperative wound infection, perioperative coagulopathy and an increase of postoperative morbid cardiac events. Perioperative hypothermia can be avoided by warming patients actively during general anesthesia. Fever is a controlled increase of core body temperature. Various causes of perioperative fever are given. Fever is usually attenuated by general anesthesia. Typically, patients develop a fever of greater magnitude in the postoperative phase. Postoperative fever is fairly common. The incidence of fever varies with type and duration of surgery, patient's age, surgical site and preoperative inflammation.

  14. Body temperatures in dinosaurs: what can growth curves tell us?

    Directory of Open Access Journals (Sweden)

    Eva Maria Griebeler

    Full Text Available To estimate the body temperature (BT of seven dinosaurs Gillooly, Alleen, and Charnov (2006 used an equation that predicts BT from the body mass and maximum growth rate (MGR with the latter preserved in ontogenetic growth trajectories (BT-equation. The results of these authors evidence inertial homeothermy in Dinosauria and suggest that, due to overheating, the maximum body size in Dinosauria was ultimately limited by BT. In this paper, I revisit this hypothesis of Gillooly, Alleen, and Charnov (2006. I first studied whether BTs derived from the BT-equation of today's crocodiles, birds and mammals are consistent with core temperatures of animals. Second, I applied the BT-equation to a larger number of dinosaurs than Gillooly, Alleen, and Charnov (2006 did. In particular, I estimated BT of Archaeopteryx (from two MGRs, ornithischians (two, theropods (three, prosauropods (three, and sauropods (nine. For extant species, the BT value estimated from the BT-equation was a poor estimate of an animal's core temperature. For birds, BT was always strongly overestimated and for crocodiles underestimated; for mammals the accuracy of BT was moderate. I argue that taxon-specific differences in the scaling of MGR (intercept and exponent of the regression line, log-log-transformed and in the parameterization of the Arrhenius model both used in the BT-equation as well as ecological and evolutionary adaptations of species cause these inaccuracies. Irrespective of the found inaccuracy of BTs estimated from the BT-equation and contrary to the results of Gillooly, Alleen, and Charnov (2006 I found no increase in BT with increasing body mass across all dinosaurs (Sauropodomorpha, Sauropoda studied. This observation questions that, due to overheating, the maximum size in Dinosauria was ultimately limited by BT. However, the general high inaccuracy of dinosaurian BTs derived from the BT-equation makes a reliable test of whether body size in dinosaurs was ultimately

  15. Body temperatures in dinosaurs: what can growth curves tell us?

    Science.gov (United States)

    Griebeler, Eva Maria

    2013-01-01

    To estimate the body temperature (BT) of seven dinosaurs Gillooly, Alleen, and Charnov (2006) used an equation that predicts BT from the body mass and maximum growth rate (MGR) with the latter preserved in ontogenetic growth trajectories (BT-equation). The results of these authors evidence inertial homeothermy in Dinosauria and suggest that, due to overheating, the maximum body size in Dinosauria was ultimately limited by BT. In this paper, I revisit this hypothesis of Gillooly, Alleen, and Charnov (2006). I first studied whether BTs derived from the BT-equation of today's crocodiles, birds and mammals are consistent with core temperatures of animals. Second, I applied the BT-equation to a larger number of dinosaurs than Gillooly, Alleen, and Charnov (2006) did. In particular, I estimated BT of Archaeopteryx (from two MGRs), ornithischians (two), theropods (three), prosauropods (three), and sauropods (nine). For extant species, the BT value estimated from the BT-equation was a poor estimate of an animal's core temperature. For birds, BT was always strongly overestimated and for crocodiles underestimated; for mammals the accuracy of BT was moderate. I argue that taxon-specific differences in the scaling of MGR (intercept and exponent of the regression line, log-log-transformed) and in the parameterization of the Arrhenius model both used in the BT-equation as well as ecological and evolutionary adaptations of species cause these inaccuracies. Irrespective of the found inaccuracy of BTs estimated from the BT-equation and contrary to the results of Gillooly, Alleen, and Charnov (2006) I found no increase in BT with increasing body mass across all dinosaurs (Sauropodomorpha, Sauropoda) studied. This observation questions that, due to overheating, the maximum size in Dinosauria was ultimately limited by BT. However, the general high inaccuracy of dinosaurian BTs derived from the BT-equation makes a reliable test of whether body size in dinosaurs was ultimately limited

  16. Genetic variablilities of body temperature and resting behaviour in ...

    African Journals Online (AJOL)

    This implies that neither progeny nor generation had effect on body temperature. The Alpha strain exhibited more resting behaviour than did the exotic and the pure native types. Majority of the birds rested in the afternoon at 2.00 pm. This could be attributed to the fact that at 2.00 pm the weather is hot and birds search for a ...

  17. Alterations in core body temperature, locomotor activity, and corticosterone following acute and repeated social defeat of male NMRI mice.

    Science.gov (United States)

    Keeney, A J; Hogg, S; Marsden, C A

    Repeated social defeat of male NMRI mice, coupled with the stress of continuously living opposite a dominant animal, induces a citalopram-reversible increase in anxiety. The experiments reported in the present paper were performed in an attempt to further validate this paradigm by studying the effects of acute and repeated social defeat on corticosterone and the circadian rhythms of core body temperature and locomotor activity, measured by telemetry. Acute social defeat induced a large (controls: 37.14+/-0.29 degrees C; subordinates: 39.79+/-0.33 degrees C) increase in core body temperature and corticosterone (controls: 30.14+/-2.70 ng/ml; subordinates: 89.62+/-9.25 ng/ml). Repeated social defeat (24 defeats) induced a chronic elevation in core body temperature across 24-h (controls: 36.62+/-0.04 degrees C; subordinates: 37.11+/-0.16 degrees C) in subordinate animals and a very large increase in corticosterone (controls: 28.60+/-1.27 ng/ml; subordinates: 441.52+/-8.86 ng/ml). These results illustrate that the chronic social defeat procedure described in this paper induces a state of chronic stress in the subordinate animals. Further studies are warranted to ascertain if the chronic hyperthermia and increases in corticosterone observed in the subordinate animals could be attenuated by chronic antidepressant treatment, thus further extending the predictive validity of this model.

  18. Basal body temperature as a biomarker of healthy aging.

    Science.gov (United States)

    Simonsick, Eleanor M; Meier, Helen C S; Shaffer, Nancy Chiles; Studenski, Stephanie A; Ferrucci, Luigi

    2016-12-01

    Scattered evidence indicates that a lower basal body temperature may be associated with prolonged health span, yet few studies have directly evaluated this relationship. We examined cross-sectional and longitudinal associations between early morning oral temperature (95.0-98.6 °F) and usual gait speed, endurance walk performance, fatigability, and grip strength in 762 non-frail men (52 %) and women aged 65-89 years participating in the Baltimore Longitudinal Study of Aging. Since excessive adiposity (body mass index ≥35 kg/m 2 or waist-to-height ratio ≥0.62) may alter temperature set point, associations were also examined within adiposity strata. Overall, controlling for age, race, sex, height, exercise, and adiposity, lower temperature was associated with faster gait speed, less time to walk 400 m quickly, and lower perceived exertion following 5-min of walking at 0.67 m/s (all p ≤ 0.02). In the non-adipose (N = 662), these associations were more robust (all p ≤ 0.006). Direction of association was reversed in the adipose (N = 100), but none attained significance (all p > 0.22). Over 2.2 years, basal temperature was not associated with functional change in the overall population or non-adipose. Among the adipose, lower baseline temperature was associated with greater decline in endurance walking performance (p = 0.006). In longitudinal analyses predicting future functional performance, low temperature in the non-adipose was associated with faster gait speed (p = 0.021) and less time to walk 400 m quickly (p = 0.003), whereas in the adipose, lower temperature was associated with slower gait speed (p = 0.05) and more time to walk 400 m (p = 0.008). In older adults, lower basal body temperature appears to be associated with healthy aging in the absence of excessive adiposity.

  19. Thermometry, calorimetry, and mean body temperature during heat stress.

    Science.gov (United States)

    Kenny, Glen P; Jay, Ollie

    2013-10-01

    Heat balance in humans is maintained at near constant levels through the adjustment of physiological mechanisms that attain a balance between the heat produced within the body and the heat lost to the environment. Heat balance is easily disturbed during changes in metabolic heat production due to physical activity and/or exposure to a warmer environment. Under such conditions, elevations of skin blood flow and sweating occur via a hypothalamic negative feedback loop to maintain an enhanced rate of dry and evaporative heat loss. Body heat storage and changes in core temperature are a direct result of a thermal imbalance between the rate of heat production and the rate of total heat dissipation to the surrounding environment. The derivation of the change in body heat content is of fundamental importance to the physiologist assessing the exposure of the human body to environmental conditions that result in thermal imbalance. It is generally accepted that the concurrent measurement of the total heat generated by the body and the total heat dissipated to the ambient environment is the most accurate means whereby the change in body heat content can be attained. However, in the absence of calorimetric methods, thermometry is often used to estimate the change in body heat content. This review examines heat exchange during challenges to heat balance associated with progressive elevations in environmental heat load and metabolic rate during exercise. Further, we evaluate the physiological responses associated with heat stress and discuss the thermal and nonthermal influences on the body's ability to dissipate heat from a heat balance perspective.

  20. A Wearable Thermometry for Core Body Temperature Measurement and Its Experimental Verification.

    Science.gov (United States)

    Huang, Ming; Tamura, Toshiyo; Tang, Zunyi; Chen, Wenxi; Kanaya, Shigehiko

    2017-05-01

    A wearable thermometry for core body temperature (CBT) measurement has both healthcare and clinical applications. On the basis of the mechanism of bioheat transfer, we earlier designed and improved a wearable thermometry using the dual-heat-flux method for CBT measurement. In this study, this thermometry is examined experimentally. We studied a fast-changing CBT measurement (FCCM, 55 min, 12 subjects) inside a thermostatic chamber and performed long-term monitoring of CBT (LTM, 24 h, six subjects). When compared with a reference, the CoreTemp CM-210 by Terumo, FCCM shows 0.07 °C average difference and a 95% CI of [-0.27, 0.12] °C. LTM shows no significant difference in parameters for the inference of circadian rhythm. The FCCM and LTM both simulated scenarios in which this thermometry could be used for intensive monitoring and daily healthcare, respectively. The results suggest that because of its convenient design, this thermometry may be an ideal choice for conventional CBT measurements.

  1. Integration of biological clocks and rhythms.

    Science.gov (United States)

    Refinetti, Roberto

    2012-04-01

    Animals, plants, and microorganisms exhibit numerous biological rhythms that are generated by numerous biological clocks. This article summarizes experimental data pertinent to the often-ignored issue of integration of multiple rhythms. Five contexts of integration are discussed: (i) integration of circadian rhythms of multiple processes within an individual organism, (ii) integration of biological rhythms operating in different time scales (such as tidal, daily, and seasonal), (iii) integration of rhythms across multiple species, (iv) integration of rhythms of different members of a species, and (v) integration of rhythmicity and physiological homeostasis. Understanding of these multiple rhythmic interactions is an important first step in the eventual thorough understanding of how organisms arrange their vital functions temporally within and without their bodies. © 2012 American Physiological Society. Compr Physiol 2:1213-1239, 2012.

  2. Circadian Rhythms in Cyanobacteria

    Science.gov (United States)

    Golden, Susan S.

    2015-01-01

    SUMMARY Life on earth is subject to daily and predictable fluctuations in light intensity, temperature, and humidity created by rotation of the earth. Circadian rhythms, generated by a circadian clock, control temporal programs of cellular physiology to facilitate adaptation to daily environmental changes. Circadian rhythms are nearly ubiquitous and are found in both prokaryotic and eukaryotic organisms. Here we introduce the molecular mechanism of the circadian clock in the model cyanobacterium Synechococcus elongatus PCC 7942. We review the current understanding of the cyanobacterial clock, emphasizing recent work that has generated a more comprehensive understanding of how the circadian oscillator becomes synchronized with the external environment and how information from the oscillator is transmitted to generate rhythms of biological activity. These results have changed how we think about the clock, shifting away from a linear model to one in which the clock is viewed as an interactive network of multifunctional components that are integrated into the context of the cell in order to pace and reset the oscillator. We conclude with a discussion of how this basic timekeeping mechanism differs in other cyanobacterial species and how information gleaned from work in cyanobacteria can be translated to understanding rhythmic phenomena in other prokaryotic systems. PMID:26335718

  3. Lower core body temperature and greater body fat are components of a human thrifty phenotype.

    Science.gov (United States)

    Reinhardt, M; Schlögl, M; Bonfiglio, S; Votruba, S B; Krakoff, J; Thearle, M S

    2016-05-01

    In small studies, a thrifty human phenotype, defined by a greater 24-hour energy expenditure (EE) decrease with fasting, is associated with less weight loss during caloric restriction. In rodents, models of diet-induced obesity often have a phenotype including a reduced EE and decreased core body temperature. We assessed whether a thrifty human phenotype associates with differences in core body temperature or body composition. Data for this cross-sectional analysis were obtained from 77 individuals participating in one of two normal physiology studies while housed on our clinical research unit. Twenty-four-hour EE using a whole-room indirect calorimeter and 24-h core body temperature were measured during 24 h each of fasting and 200% overfeeding with a diet consisting of 50% carbohydrates, 20% protein and 30% fat. Body composition was measured by dual X-ray absorptiometry. To account for the effects of body size on EE, changes in EE were expressed as a percentage change from 24-hour EE (%EE) during energy balance. A greater %EE decrease with fasting correlated with a smaller %EE increase with overfeeding (r=0.27, P=0.02). The %EE decrease with fasting was associated with both fat mass and abdominal fat mass, even after accounting for covariates (β=-0.16 (95% CI: -0.26, -0.06) %EE per kg fat mass, P=0.003; β=-0.0004 (-0.0007, -0.00004) %EE kg(-1) abdominal fat mass, P=0.03). In men, a greater %EE decrease in response to fasting was associated with a lower 24- h core body temperature, even after adjusting for covariates (β=1.43 (0.72, 2.15) %EE per 0.1 °C, P=0.0003). Thrifty individuals, as defined by a larger EE decrease with fasting, were more likely to have greater overall and abdominal adiposity as well as lower core body temperature consistent with a more efficient metabolism.

  4. Lithium and bipolar disorder: Impacts from molecular to behavioural circadian rhythms.

    Science.gov (United States)

    Moreira, Jeverson; Geoffroy, Pierre Alexis

    2016-01-01

    Bipolar disorder (BD) is a severe and common psychiatric disorder. BD pathogenesis, clinical manifestations and relapses are associated with numerous circadian rhythm abnormalities. Lithium (Li) is the first-line treatment in BD, and its therapeutic action has been related to its ability to alter circadian rhythms. We systematically searched the PubMed database until January 2016, aiming to critically examine published studies investigating direct and indirect effects of Li on circadian rhythms. The results, from the 95 retained studies, indicated that Li: acts directly on the molecular clocks; delays the phase of sleep-wakefulness rhythms and the peak elevation of diurnal cycle body temperature; reduces the amplitude and shortens the duration of activity rhythms and lengthens free-running rhythms. Chronic Li treatment stabilizes free-running activity rhythms, by improving day-to-day rhythmicity of the activity, with effects that appear to be dose related. Pharmacogenetics demonstrate several associations of Li's response with circadian genes (NR1D1, GSK3β, CRY1, ARNTL, TIM, PER2). Finally, Li acts on the retinal-hypothalamic pineal pathway, influencing light sensitivity and melatonin secretion. Li is a highly investigated chronobiologic agent, and although its chronobiological effects are not completely understood, it seems highly likely that they constitute an inherent component of its therapeutic action in the treatment of mood disorders.

  5. Influence of MR imaging on the central body temperature and peripheral temperature in humans

    International Nuclear Information System (INIS)

    Vogl, T.; Krimmel, K.; Dopmeier, D.; Seiderer, M.; Lissner, J.

    1986-01-01

    Thermal effects of in vitro and in vivo MR imaging were studied at different field strengths (0.35 T, 1.5 T) and radio frequency power, using a modified fluoroptical technique. A fiber optic probe that measures with an accuracy of up to 0.1 0 C was inserted via esophageal and rectal tubes in 20 test subjects to measure central body temperature. In another ten subjects the temperature was measured subcutaneously and by an intravenous catheter system. No significant temperature change was measurable in the central parts of the body (rectum, esophagus) within the static magnetic field and during MR imaging. Subcutaneous and intravenous measurements of the superficial temperature of the arm led to the same conclusions. Theoretical calculations of the absorbed energy confirm these findings

  6. Primate body temperature and sleep responses to lower body positive pressure

    Science.gov (United States)

    Edgar, D. M.; Fuller, C. A.

    1984-01-01

    Cephalic fluid shifts, induced by lower body positive pressure (LBPP) are known to influence various physiological systems (i.e., cardiovascular and renal). In earlier experiments, an apparent change in the arousal state of primates in such LBPP conditions was observed. This study was designed to examine the effects of LBPP on arousal state and body temperature level which is normally correlated with sleep. Chair-restrained male squirrel monkeys were exposed to 40 mmHg LBPP for 90-100 minutes between the daytime hours of 13:00-15:00. Each monkey was placed in a specially modified restraint chair to which they were highly trained. Deep body temperature (DBT) was collected from 10 animals. Sleep parameters were obtained from six animals chronically implanted for sleep recording. A video camera was used to observe each animal's apparent state of arousal. LBPP resulted in an approximate 0.9 C decrease in DBT. During video observation, some animals appeared drowsy during LBPP; however, sleep recording revealed no significant changes in the state of arousal. Thus, LBPP is capable of inducing a mild hyperthermia. Further, the mechanisms underlying the observed lowering of body temperature appear to be independent of arousal state.

  7. Temperature Evaluation of Heat Transferring Body while Preparing Temperature Chart of Heating Technologies and Metal Thermal Treatment

    Directory of Open Access Journals (Sweden)

    A. P. Nesenchuk

    2011-01-01

    Full Text Available The paper considers problems pertaining to temperature evaluation of a heat transferring body in the operational space of high temperature installations. A formula for evaluation of this temperature has been written down in the paper. Calculation of a heating transferring body (furnace makes it possible to realize temperature chart parameters in the plant heating technologies and steel thermal treatment.

  8. Measuring core body temperature with a non-invasive sensor.

    Science.gov (United States)

    Mazgaoker, Savyon; Ketko, Itay; Yanovich, Ran; Heled, Yuval; Epstein, Yoram

    2017-05-01

    In various occupations, workers may be exposed to extreme environmental conditions and physical activities. Under these conditions the ability to follow the workers' body temperature may protect them from overheating that may lead to heat related injuries. The "Dräger" Double Sensor (DS) is a novel device for assessing body-core temperature (T c ). The purpose of this study was to evaluate the accuracy of the DS in measuring T c under heat stress. Seventeen male participants performed a three stage protocol: 30min rest in a thermal comfort environment (20-22°C, 50% relative humidity), followed by an exposure to a hot environment of 40°C, 40% relative humidity -30min at rest and 60min of exercise (walking on a treadmill at 5km/h and 2% elevation). Simultaneously temperatures measured by the DS (T DS ) and by rectal temperature (T re ) (YSI-401 thermistor) were recorded and then compared. During the three stages of the study the average temperature obtained by the DS was within±0.3°C of rectal measurement. The correlation between T DS and T re was significantly better during the heat exposures phases than during resting under comfort conditions. These preliminary results are promising for potential use of the DS by workers under field conditions and especially under environmental heat stress or when dressed in protective garments. For this goal, further investigations are required to validate the accuracy of the DS under various levels of heat stress, clothing and working levels. Copyright © 2017. Published by Elsevier Ltd.

  9. Age-related changes in core body temperature and activity in triple-transgenic Alzheimer’s disease (3xTgAD mice

    Directory of Open Access Journals (Sweden)

    Elysse M. Knight

    2013-01-01

    Alzheimer’s disease (AD is characterised, not only by cognitive deficits and neuropathological changes, but also by several non-cognitive behavioural symptoms that can lead to a poorer quality of life. Circadian disturbances in core body temperature and physical activity are reported in AD patients, although the cause and consequences of these changes are unknown. We therefore characterised circadian patterns of body temperature and activity in male triple transgenic AD mice (3xTgAD and non-transgenic (Non-Tg control mice by remote radiotelemetry. At 4 months of age, daily temperature rhythms were phase advanced and by 6 months of age an increase in mean core body temperature and amplitude of temperature rhythms were observed in 3xTgAD mice. No differences in daily activity rhythms were seen in 4- to 9-month-old 3xTgAD mice, but by 10 months of age an increase in mean daily activity and the amplitude of activity profiles for 3xTgAD mice were detected. At all ages (4–10 months, 3xTgAD mice exhibited greater food intake compared with Non-Tg mice. The changes in temperature did not appear to be solely due to increased food intake and were not cyclooxygenase dependent because the temperature rise was not abolished by chronic ibuprofen treatment. No β-amyloid (Aβ plaques or neurofibrillary tangles were noted in the hypothalamus of 3xTgAD mice, a key area involved in temperature regulation, although these pathological features were observed in the hippocampus and amygdala of 3xTgAD mice from 10 months of age. These data demonstrate age-dependent changes in core body temperature and activity in 3xTgAD mice that are present before significant AD-related neuropathology and are analogous to those observed in AD patients. The 3xTgAD mouse might therefore be an appropriate model for studying the underlying mechanisms involved in non-cognitive behavioural changes in AD.

  10. Age-related changes in core body temperature and activity in triple-transgenic Alzheimer’s disease (3xTgAD) mice

    Science.gov (United States)

    Knight, Elysse M.; Brown, Timothy M.; Gümüsgöz, Sarah; Smith, Jennifer C. M.; Waters, Elizabeth J.; Allan, Stuart M.; Lawrence, Catherine B.

    2013-01-01

    SUMMARY Alzheimer’s disease (AD) is characterised, not only by cognitive deficits and neuropathological changes, but also by several non-cognitive behavioural symptoms that can lead to a poorer quality of life. Circadian disturbances in core body temperature and physical activity are reported in AD patients, although the cause and consequences of these changes are unknown. We therefore characterised circadian patterns of body temperature and activity in male triple transgenic AD mice (3xTgAD) and non-transgenic (Non-Tg) control mice by remote radiotelemetry. At 4 months of age, daily temperature rhythms were phase advanced and by 6 months of age an increase in mean core body temperature and amplitude of temperature rhythms were observed in 3xTgAD mice. No differences in daily activity rhythms were seen in 4- to 9-month-old 3xTgAD mice, but by 10 months of age an increase in mean daily activity and the amplitude of activity profiles for 3xTgAD mice were detected. At all ages (4–10 months), 3xTgAD mice exhibited greater food intake compared with Non-Tg mice. The changes in temperature did not appear to be solely due to increased food intake and were not cyclooxygenase dependent because the temperature rise was not abolished by chronic ibuprofen treatment. No β-amyloid (Aβ) plaques or neurofibrillary tangles were noted in the hypothalamus of 3xTgAD mice, a key area involved in temperature regulation, although these pathological features were observed in the hippocampus and amygdala of 3xTgAD mice from 10 months of age. These data demonstrate age-dependent changes in core body temperature and activity in 3xTgAD mice that are present before significant AD-related neuropathology and are analogous to those observed in AD patients. The 3xTgAD mouse might therefore be an appropriate model for studying the underlying mechanisms involved in non-cognitive behavioural changes in AD. PMID:22864021

  11. Age-related changes in core body temperature and activity in triple-transgenic Alzheimer's disease (3xTgAD) mice.

    Science.gov (United States)

    Knight, Elysse M; Brown, Timothy M; Gümüsgöz, Sarah; Smith, Jennifer C M; Waters, Elizabeth J; Allan, Stuart M; Lawrence, Catherine B

    2013-01-01

    Alzheimer's disease (AD) is characterised, not only by cognitive deficits and neuropathological changes, but also by several non-cognitive behavioural symptoms that can lead to a poorer quality of life. Circadian disturbances in core body temperature and physical activity are reported in AD patients, although the cause and consequences of these changes are unknown. We therefore characterised circadian patterns of body temperature and activity in male triple transgenic AD mice (3xTgAD) and non-transgenic (Non-Tg) control mice by remote radiotelemetry. At 4 months of age, daily temperature rhythms were phase advanced and by 6 months of age an increase in mean core body temperature and amplitude of temperature rhythms were observed in 3xTgAD mice. No differences in daily activity rhythms were seen in 4- to 9-month-old 3xTgAD mice, but by 10 months of age an increase in mean daily activity and the amplitude of activity profiles for 3xTgAD mice were detected. At all ages (4-10 months), 3xTgAD mice exhibited greater food intake compared with Non-Tg mice. The changes in temperature did not appear to be solely due to increased food intake and were not cyclooxygenase dependent because the temperature rise was not abolished by chronic ibuprofen treatment. No β-amyloid (Aβ) plaques or neurofibrillary tangles were noted in the hypothalamus of 3xTgAD mice, a key area involved in temperature regulation, although these pathological features were observed in the hippocampus and amygdala of 3xTgAD mice from 10 months of age. These data demonstrate age-dependent changes in core body temperature and activity in 3xTgAD mice that are present before significant AD-related neuropathology and are analogous to those observed in AD patients. The 3xTgAD mouse might therefore be an appropriate model for studying the underlying mechanisms involved in non-cognitive behavioural changes in AD.

  12. Body temperature patterns before, during, and after semi-natural hibernation in the European ground squirrel

    NARCIS (Netherlands)

    Hut, R.A.; Barnes, B.M.; Daan, S.; Heldmaier, G.

    Ground squirrels undergo extreme body temperature fluctuations during hibernation. The effect of low body temperatures on the mammalian circadian system is still under debate. Using implanted temperature loggers, we recorded body temperature patterns in European ground squirrels kept in an enclosure

  13. Significance of circadian rhythms in severely brain-injured patients: A clue to consciousness?

    Science.gov (United States)

    Blume, Christine; Lechinger, Julia; Santhi, Nayantara; del Giudice, Renata; Gnjezda, Maria-Teresa; Pichler, Gerald; Scarpatetti, Monika; Donis, Johann; Michitsch, Gabriele; Schabus, Manuel

    2017-05-16

    To investigate the relationship between the presence of a circadian body temperature rhythm and behaviorally assessed consciousness levels in patients with disorders of consciousness (DOC; i.e., vegetative state/unresponsive wakefulness syndrome or minimally conscious state). In a cross-sectional study, we investigated the presence of circadian temperature rhythms across 6 to 7 days using external skin temperature sensors in 18 patients with DOC. Beyond this, we examined the relationship between behaviorally assessed consciousness levels and circadian rhythmicity. Analyses with Lomb-Scargle periodograms revealed significant circadian rhythmicity in all patients (range 23.5-26.3 hours). We found that especially scores on the arousal subscale of the Coma Recovery Scale-Revised were closely linked to the integrity of circadian variations in body temperature. Finally, we piloted whether bright light stimulation could boost circadian rhythmicity and found positive evidence in 2 out of 8 patients. The study provides evidence for an association between circadian body temperature rhythms and arousal as a necessary precondition for consciousness. Our findings also make a case for circadian rhythms as a target for treatment as well as the application of diagnostic and therapeutic means at times when cognitive performance is expected to peak. Copyright © 2017 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.

  14. Demonstration of a day-night rhythm in human skeletal muscle oxidative capacity.

    Science.gov (United States)

    van Moorsel, Dirk; Hansen, Jan; Havekes, Bas; Scheer, Frank A J L; Jörgensen, Johanna A; Hoeks, Joris; Schrauwen-Hinderling, Vera B; Duez, Helene; Lefebvre, Philippe; Schaper, Nicolaas C; Hesselink, Matthijs K C; Staels, Bart; Schrauwen, Patrick

    2016-08-01

    A disturbed day-night rhythm is associated with metabolic perturbations that can lead to obesity and type 2 diabetes mellitus (T2DM). In skeletal muscle, a reduced oxidative capacity is also associated with the development of T2DM. However, whether oxidative capacity in skeletal muscle displays a day-night rhythm in humans has so far not been investigated. Lean, healthy subjects were enrolled in a standardized living protocol with regular meals, physical activity and sleep to reflect our everyday lifestyle. Mitochondrial oxidative capacity was examined in skeletal muscle biopsies taken at five time points within a 24-hour period. Core-body temperature was lower during the early night, confirming a normal day-night rhythm. Skeletal muscle oxidative capacity demonstrated a robust day-night rhythm, with a significant time effect in ADP-stimulated respiration (state 3 MO, state 3 MOG and state 3 MOGS, p body energy expenditure, with peak energy expenditure at 11 PM and lowest energy expenditure at 4 AM (p < 0.001). In addition, we demonstrate rhythmicity in mRNA expression of molecular clock genes in human skeletal muscle. Our results suggest that the biological clock drives robust rhythms in human skeletal muscle oxidative metabolism. It is tempting to speculate that disruption of these rhythms contribute to the deterioration of metabolic health associated with circadian misalignment.

  15. Gap in the black-body spectrum at low temperature

    International Nuclear Information System (INIS)

    Schwarz, Markus; Hofmann, Ralf; Giacosa, Francesco

    2007-01-01

    We postulate that the U(1) Y factor of the Standard Model is an effective manifestation of SU(2) gauge dynamics being dynamically broken by nonperturbative effects. The modified propagation properties of the photon at low temperatures and momenta are computed. As a result of strong screening, the presence of a sizable gap in the spectral power of a black body at temperatures T = 5...20 K and for low frequencies is predicted: A table-top experiment should be able to discover this gap. If the gap is observed then the Standard Model's mechanism for electroweak symmetry-breaking is endangered by a contradiction with Big-Bang nucleosynthesis. Based on our results, we propose an explanation for the stability of cold, old, dilute, and large clouds of atomic hydrogen in between spiral arms of the outer galaxy

  16. Systems Modeling for Crew Core Body Temperature Prediction Postlanding

    Science.gov (United States)

    Cross, Cynthia; Ochoa, Dustin

    2010-01-01

    The Orion Crew Exploration Vehicle, NASA s latest crewed spacecraft project, presents many challenges to its designers including ensuring crew survivability during nominal and off nominal landing conditions. With a nominal water landing planned off the coast of San Clemente, California, off nominal water landings could range from the far North Atlantic Ocean to the middle of the equatorial Pacific Ocean. For all of these conditions, the vehicle must provide sufficient life support resources to ensure that the crew member s core body temperatures are maintained at a safe level prior to crew rescue. This paper will examine the natural environments, environments created inside the cabin and constraints associated with post landing operations that affect the temperature of the crew member. Models of the capsule and the crew members are examined and analysis results are compared to the requirement for safe human exposure. Further, recommendations for updated modeling techniques and operational limits are included.

  17. Evidence for time-of-day dependent effect of neurotoxic dorsomedial hypothalamic lesions on food anticipatory circadian rhythms in rats.

    Directory of Open Access Journals (Sweden)

    Glenn J Landry

    Full Text Available The dorsomedial hypothalamus (DMH is a site of circadian clock gene and immediate early gene expression inducible by daytime restricted feeding schedules that entrain food anticipatory circadian rhythms in rats and mice. The role of the DMH in the expression of anticipatory rhythms has been evaluated using different lesion methods. Partial lesions created with the neurotoxin ibotenic acid (IBO have been reported to attenuate food anticipatory rhythms, while complete lesions made with radiofrequency current leave anticipatory rhythms largely intact. We tested a hypothesis that the DMH and fibers of passage spared by IBO lesions play a time-of-day dependent role in the expression of food anticipatory rhythms. Rats received intra-DMH microinjections of IBO and activity and body temperature (T(b rhythms were recorded by telemetry during ad-lib food access, total food deprivation and scheduled feeding, with food provided for 4-h/day for 20 days in the middle of the light period and then for 20 days late in the dark period. During ad-lib food access, rats with DMH lesions exhibited a lower amplitude and mean level of light-dark entrained activity and T(b rhythms. During the daytime feeding schedule, all rats exhibited food anticipatory activity and T(b rhythms that persisted during 2 days without food in constant dark. In some rats with partial or total DMH ablation, the magnitude of the anticipatory rhythm was weak relative to most intact rats. When mealtime was shifted to the late night, the magnitude of the food anticipatory activity rhythms in these cases was restored to levels characteristic of intact rats. These results confirm that rats can anticipate scheduled daytime or nighttime meals without the DMH. Improved anticipation at night suggests a modulatory role for the DMH in the expression of food anticipatory activity rhythms during the daily light period, when nocturnal rodents normally sleep.

  18. The effect of body temperature on the hunting response of the middle finger skin temperature.

    Science.gov (United States)

    Daanen, H A; Van de Linde, F J; Romet, T T; Ducharme, M B

    1997-01-01

    The relationship between body temperature and the hunting response (intermittent supply of warm blood to cold exposed extremities) was quantified for nine subjects by immersing one hand in 8 degree C water while their body was either warm, cool or comfortable. Core and skin temperatures were manipulated by exposing the subjects to different ambient temperatures (30, 22, or 15 degrees C), by adjusting their clothing insulation (moderate, light, or none), and by drinking beverages at different temperatures (43, 37 and 0 degrees C). The middle finger temperature (Tfi) response was recorded, together with ear canal (Tear), rectal (Tre), and mean skin temperature (Tsk). The induced mean Tear changes were -0.34 (0.08) and +0.29 (0.03) degrees C following consumption of the cold and hot beverage, respectively. Tsk ranged from 26.7 to 34.5 degrees C during the tests. In the warm environment after a hot drink, the initial finger temperature (T(fi,base)) was 35.3 (0.4) degrees C, the minimum finger temperature during immersion (T(fi,min)) was 11.3 (0.5) degrees C, and 2.6 (0.4) hunting waves occurred in the 30-min immersion period. In the neutral condition (thermoneutral room and beverage) T(fi,base) was 32.1 (1.0) degrees C, T(fi,min) was 9.6 (0.3) degrees C, and 1.6 (0.2) waves occurred. In the cold environment after a cold drink, these values were 19.3 (0.9) degrees C, 8.7 (0.2) degrees C, and 0.8 (0.2) waves, respectively. A colder body induced a decrease in the magnitude and frequency of the hunting response. The total heat transferred from the hand to the water, as estimated by the area under the middle finger temperature curve, was also dependent upon the induced increase or decrease in Tear and Tsk. We conclude that the characteristics of the hunting temperature response curve of the finger are in part determined by core temperature and Tsk. Both T(fi,min) and the maximal finger temperature during immersion were higher when the core temperature was elevated; Tsk

  19. Human body temperature and new approaches to constructing temperature-sensitive bacterial vaccines.

    Science.gov (United States)

    White, Matthew D; Bosio, Catharine M; Duplantis, Barry N; Nano, Francis E

    2011-09-01

    Many of the live human and animal vaccines that are currently in use are attenuated by virtue of their temperature-sensitive (TS) replication. These vaccines are able to function because they can take advantage of sites in mammalian bodies that are cooler than the core temperature, where TS vaccines fail to replicate. In this article, we discuss the distribution of temperature in the human body, and relate how the temperature differential can be exploited for designing and using TS vaccines. We also examine how one of the coolest organs of the body, the skin, contains antigen-processing cells that can be targeted to provoke the desired immune response from a TS vaccine. We describe traditional approaches to making TS vaccines, and highlight new information and technologies that are being used to create a new generation of engineered TS vaccines. We pay particular attention to the recently described technology of substituting essential genes from Arctic bacteria for their homologues in mammalian pathogens as a way of creating TS vaccines.

  20. Correlated colour temperature of morning light influences alertness and body temperature.

    Science.gov (United States)

    Te Kulve, Marije; Schlangen, Luc; Schellen, Lisje; Souman, Jan L; van Marken Lichtenbelt, Wouter

    2018-03-01

    Though several studies have reported human alertness to be affected by the intensity and spectral composition of ambient light, the mechanism behind this effect is still largely unclear, especially for daytime exposure. Alerting effects of nocturnal light exposure are correlated with melatonin suppression, but melatonin levels are generally low during the day. The aim of this study was to explore the alerting effect of light in the morning for different correlated colour temperature (CCT) values, as well as its interaction with ambient temperature. Body temperature and perceived comfort were included in the study as possible mediating factors. In a randomized crossover design, 16 healthy females participated in two sessions, once under 2700K and once under 6500K light (both 55lx). Each session consisted of a baseline, a cool, a neutral and a warm thermal environment. Alertness as measured in a reaction time task was lower for the 6500K exposure, while subjective sleepiness was not affected by CCT. Also, core body temperature was higher under 6500K. Skin temperature parameters and perceived comfort were positively correlated with subjective sleepiness. Reaction time correlated with heat loss, but this association did not explain why the reaction time was improved for 2700K. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Body temperature increases during pediatric full mouth rehabilitation surgery under general anesthesia

    Directory of Open Access Journals (Sweden)

    Yi-Shan Chuang

    2015-12-01

    Conclusion: Body temperature transiently increased during pediatric full mouth rehabilitation surgery. The increase in body temperature was associated with operation duration. The etiology is uncertain. Continuous body temperature monitoring and the application of both heating and cooling devices during pediatric full mouth rehabilitation surgery should be mandatory.

  2. Pregnancy Suppresses the Daily Rhythmicity of Core Body Temperature and Adipose Metabolic Gene Expression in the Mouse.

    Science.gov (United States)

    Wharfe, Michaela D; Wyrwoll, Caitlin S; Waddell, Brendan J; Mark, Peter J

    2016-09-01

    Maternal adaptations in lipid metabolism are crucial for pregnancy success due to the role of white adipose tissue as an energy store and the dynamic nature of energy needs across gestation. Because lipid metabolism is regulated by the rhythmic expression of clock genes, it was hypothesized that maternal metabolic adaptations involve changes in both adipose clock gene expression and the rhythmic expression of downstream metabolic genes. Maternal core body temperature (Tc) was investigated as a possible mechanism driving pregnancy-induced changes in clock gene expression. Gonadal adipose tissue and plasma were collected from C57BL/6J mice before and on days 6, 10, 14, and 18 of pregnancy (term 19 d) at 4-hour intervals across a 24-hour period. Adipose expression of clock genes and downstream metabolic genes were determined by quantitative RT-PCR, and Tc was measured by intraperitoneal temperature loggers. Adipose clock gene expression showed robust rhythmicity throughout pregnancy, but absolute levels varied substantially across gestation. Rhythmic expression of the metabolic genes Lipe, Pnpla2, and Lpl was clearly evident before pregnancy; however, this rhythmicity was lost with the onset of pregnancy. Tc rhythm was significantly altered by pregnancy, with a 65% decrease in amplitude by term and a 0.61°C decrease in mesor between days 6 and 18. These changes in Tc, however, did not appear to be linked to adipose clock gene expression across pregnancy. Overall, our data show marked adaptations in the adipose clock in pregnancy, with an apparent decoupling of adipose clock and lipolytic/lipogenic gene rhythms from early in gestation.

  3. Visible Battle Rhythm

    National Research Council Canada - National Science Library

    Cort, Brian; Bouchard, Alain; Gouin, Denis; Proulx, Pascale; Wright, William

    2006-01-01

    .... Visual Battle Rhythm (VBR) is a software prototype which updates the battle rhythm process with modern technology and careful information design to improve the synchronization, situational awareness and decision making ability of commanders...

  4. The effect of body fat percentage and body fat distribution on skin surface temperature with infrared thermography.

    Science.gov (United States)

    Salamunes, Ana Carla Chierighini; Stadnik, Adriana Maria Wan; Neves, Eduardo Borba

    2017-05-01

    This study aimed to search for relations between body fat percentage and skin temperature and to describe possible effects on skin temperature as a result of fat percentage in each anatomical site. Women (26.11±4.41 years old) (n =123) were tested for: body circumferences; skin temperatures (thermal camera); fat percentage and lean mass from trunk, upper and lower limbs; and body fat percentage (Dual-Energy X-Ray Absorptiometry). Values of minimum (T Mi ), maximum (T Ma ), and mean temperatures (T Me ) were acquired in 30 regions of interest. Pearson's correlation was estimated for body circumferences and skin temperature variables with body fat percentage. Participants were divided into groups of high and low fat percentage of each body segment, of which T Me values were compared with Student's t-test. Linear regression models for predicting body fat percentage were tested. Body fat percentage was positively correlated with body circumferences and palm temperatures, while it was negatively correlated with most temperatures, such as T Ma and T Me of posterior thighs (r =-0.495 and -0.432), T Me of posterior lower limbs (r =-0.488), T Ma of anterior thighs (r =-0.406) and T Mi and T Me of posterior arms (r =-0.447 and -0.430). Higher fat percentages in the specific anatomical sites tended to decrease T Me , especially in posterior thighs, shanks and arms. Skin temperatures and body circumferences predicted body fat percentage with 58.3% accuracy (R =0.764 and R 2 =0.583). This study clarifies that skin temperature distribution is influenced by the fat percentage of each body segment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Effect of peritoneal lavage solution temperature on body temperature in anaesthetised cats and small dogs.

    Science.gov (United States)

    Barnes, D C; Leece, E A; Trimble, T A; Demetriou, J L

    2017-05-20

    A prospective, randomised, non-blinded, clinical study to assess the effect of peritoneal lavage using warmed fluid on body temperature in anesthetised cats and dogs of less than 10 kg body mass undergoing coeliotomy. A standardised anaesthetic protocol was used. Oesophageal and rectal temperatures were measured at various time points. At the end of surgery, group 1 patients (n=10) were lavaged with 200 ml/kg sterile isotonic saline at 34±1°C and group 2 (n=10) at 40±1°C. Groups were similar with respect to age, mass, body condition and surgical incision length. Duration of anaesthesia, surgical procedures and peritoneal lavage was similar between groups. Linear regression showed no significant change in oesophageal temperature during the lavage period for group 1 (P=0.64), but a significant increase for group 2 patients (Ptemperature changes of -0.5°C (from (36.3°C to 35.9°C) and +0.9°C (from 35.4°C to 36.3°C), respectively. Similar results were found for rectal temperature, with mean changes of -0.5°C and +0.8°C (P=0.922 and 0.045), respectively. The use of isotonic crystalloid solution for peritoneal lavage at a temperature of 40±1°C significantly warms small animal patients, when applied in a clinical setting, compared with lavage solution at 34±1°C. British Veterinary Association.

  6. Body temperature regulation: Sasang typology-based perspective

    Directory of Open Access Journals (Sweden)

    Duong Duc Pham

    2015-12-01

    Full Text Available Global warming induces a dramatic elevation of heat-related morbidity and mortality worldwide. Individual variation of heat stress vulnerability depends on various factors such as age, gender, living area and conditions, health status, and individual innate characteristics. Sasang typology is a unique form of Korean traditional medicine, which is based on the hypothesis that constitution-specific traits of an individual determine the particular distinctive tendency in various aspects, including responses to the external environment. Recent scientific evidence shows that Sasang types differ in body composition, metabolic profile, susceptibility to certain disease patterns, and perspiration. This review aims to interpret these findings under the context of heat balance consisting of heat production (Hprod, heat loss (Hloss, and heat load (Hload. Based on the published data, at a given body mass, the TaeEum type tended to have a lower Hprod at rest and at the exhaustion state, which may indicate the lower metabolic efficiency of this type. Meanwhile, the surface-to-mass ratio and heat capacity of the TaeEum type appear to be lower, implying a lower heat dissipation capacity and heat storage tolerance. Thus, because of these characteristics, the TaeEum type seems to be more vulnerable to heat stress than the other constitutions. Differences in temperature regulation across constitutional types should be taken into account in daily physical activity, health management, and medical research.

  7. The Utility of the Swine Model to Assess Biological Rhythms and Their Characteristics during Different Stages of Residence in a Simulated Intensive Care Unit: A Pilot Study.

    Science.gov (United States)

    Leyden, Katrina N; Hanneman, Sandra K; Padhye, Nikhil S; Smolensky, Michael H; Kang, Duck-Hee; Chow, Diana Shu-Lian

    2015-01-01

    The purpose of this pilot study was to explore the utility of the mammalian swine model under simulated intensive care unit (sICU) conditions and mechanical ventilation (MV) for assessment of the trajectory of circadian rhythms of sedation requirement, core body temperature (CBT), pulmonary mechanics (PM) and gas exchange (GE). Data were collected prospectively with an observational time-series design to describe and compare circadian rhythms of selected study variables in four swine mechanically ventilated for up to seven consecutive days. We derived the circadian (total variance explained by rhythms of τ between 20 and 28 h)/ultradian (total variance explained by rhythms of τ between 1 and rhythms, and compare findings between the early (first 3 days) and late (subsequent days) sICU stay. All pigs exhibited statistically significant circadian rhythms (τ between 20 and 28 h) in CBT, respiratory rate and peripheral oxygen saturation, but circadian rhythms were detected less frequently for sedation requirement, spontaneous minute volume, arterial oxygen tension, arterial carbon dioxide tension and arterial pH. Sedation did not appear to mask the circadian rhythms of CBT, PM and GE. Individual subject observations were more informative than group data, and provided preliminary evidence that (a) circadian rhythms of multiple variables are lost or desynchronized in mechanically ventilated subjects, (b) robustness of circadian rhythm varies with subject morbidity and (c) healthier pigs develop more robust circadian rhythm profiles over time in the sICU. Comparison of biological rhythm profiles among sICU subjects with similar severity of illness is needed to determine if the results of this pilot study are reproducible. Identification of consistent patterns may provide insight into subject morbidity and timing of such therapeutic interventions as weaning from MV.

  8. Effect of irrigation fluid temperature on core body temperature and inflammatory response during arthroscopic shoulder surgery.

    Science.gov (United States)

    Pan, Xiaoyun; Ye, Luyou; Liu, Zhongtang; Wen, Hong; Hu, Yuezheng; Xu, Xinxian

    2015-08-01

    This study was designed to evaluate the influence of irrigation fluid on the patients' physiological response to arthroscopic shoulder surgery. Patients who were scheduled for arthroscopic shoulder surgery were prospectively included in this study. They were randomly assigned to receive warm arthroscopic irrigation fluid (Group W, n = 33) or room temperature irrigation fluid (Group RT, n = 33) intraoperatively. Core body temperature was measured at regular intervals. The proinflammatory cytokines TNF-α, IL-1, IL-6, and IL-10 were measured in drainage fluid and serum. The changes of core body temperatures in Group RT were similar with those in Group W within 15 min after induction of anesthesia, but the decreases in Group RT were significantly greater after then. The lowest temperature was 35.1 ± 0.4 °C in Group RT and 35.9 ± 0.3 °C in Group W, the difference was statistically different (P irrigation fluid compared with warm irrigation fluid. And local inflammatory response is significantly reduced by using warm irrigation fluid. It seems that warm irrigation fluid is more recommendable for arthroscopic shoulder surgery.

  9. Warm-Sensitive Neurons that Control Body Temperature.

    Science.gov (United States)

    Tan, Chan Lek; Cooke, Elizabeth K; Leib, David E; Lin, Yen-Chu; Daly, Gwendolyn E; Zimmerman, Christopher A; Knight, Zachary A

    2016-09-22

    Thermoregulation is one of the most vital functions of the brain, but how temperature information is converted into homeostatic responses remains unknown. Here, we use an unbiased approach for activity-dependent RNA sequencing to identify warm-sensitive neurons (WSNs) within the preoptic hypothalamus that orchestrate the homeostatic response to heat. We show that these WSNs are molecularly defined by co-expression of the neuropeptides BDNF and PACAP. Optical recordings in awake, behaving mice reveal that these neurons are selectively activated by environmental warmth. Optogenetic excitation of WSNs triggers rapid hypothermia, mediated by reciprocal changes in heat production and loss, as well as dramatic cold-seeking behavior. Projection-specific manipulations demonstrate that these distinct effectors are controlled by anatomically segregated pathways. These findings reveal a molecularly defined cell type that coordinates the diverse behavioral and autonomic responses to heat. Identification of these warm-sensitive cells provides genetic access to the core neural circuit regulating the body temperature of mammals. PAPERCLIP. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Effects of the TRPV1 antagonist ABT-102 on body temperature in healthy volunteers: pharmacokinetic/ pharmacodynamic analysis of three phase 1 trials.

    Science.gov (United States)

    Othman, Ahmed A; Nothaft, Wolfram; Awni, Walid M; Dutta, Sandeep

    2013-04-01

    To characterize quantitatively the relationship between ABT-102, a potent and selective TRPV1 antagonist, exposure and its effects on body temperature in humans using a population pharmacokinetic/pharmacodynamic modelling approach. Serial pharmacokinetic and body temperature (oral or core) measurements from three double-blind, randomized, placebo-controlled studies [single dose (2, 6, 18, 30 and 40 mg, solution formulation), multiple dose (2, 4 and 8 mg twice daily for 7 days, solution formulation) and multiple-dose (1, 2 and 4 mg twice daily for 7 days, solid dispersion formulation)] were analyzed. NONMEM was used for model development and the model building steps were guided by pre-specified diagnostic and statistical criteria. The final model was qualified using non-parametric bootstrap and visual predictive check. The developed body temperature model included additive components of baseline, circadian rhythm (cosine function of time) and ABT-102 effect (Emax function of plasma concentration) with tolerance development (decrease in ABT-102 Emax over time). Type of body temperature measurement (oral vs. core) was included as a fixed effect on baseline, amplitude of circadian rhythm and residual error. The model estimates (95% bootstrap confidence interval) were: baseline oral body temperature, 36.3 (36.3, 36.4)°C; baseline core body temperature, 37.0 (37.0, 37.1)°C; oral circadian amplitude, 0.25 (0.22, 0.28)°C; core circadian amplitude, 0.31 (0.28, 0.34)°C; circadian phase shift, 7.6 (7.3, 7.9) h; ABT-102 Emax , 2.2 (1.9, 2.7)°C; ABT-102 EC50 , 20 (15, 28) ng ml(-1) ; tolerance T50 , 28 (20, 43) h. At exposures predicted to exert analgesic activity in humans, the effect of ABT-102 on body temperature is estimated to be 0.6 to 0.8°C. This effect attenuates within 2 to 3 days of dosing. © 2012 Abbott Laboratories. British Journal of Clinical Pharmacology © 2012 The British Pharmacological Society.

  11. Deviation from goal pace, body temperature and body mass loss as predictors of road race performance.

    Science.gov (United States)

    Adams, William M; Hosokawa, Yuri; Belval, Luke N; Huggins, Robert A; Stearns, Rebecca L; Casa, Douglas J

    2017-03-01

    The purpose of this study was to examine the relationship between pacing, gastrointestinal temperature (T GI ), and percent body mass loss (%BML) on relative race performance during a warm weather 11.3km road race. Observational study of a sample of active runners competing in the 2014 Falmouth Road Race. Participants ingested a T GI pill and donned a GPS enabled watch with heart rate monitoring capabilities prior to the start of the race. Percent off predicted pace (% OFF ) was calculated for seven segments of the race. Separate linear regression analyses were used to assess the relationship between pace, T ​GI , and %BML on relative race performance. One-way ANOVA was used to analyse post race T GI (≥40°C vs Body temperature (pre race T GI and post race T GI ) was not predictive of overall finish time (p>0.05). There was a trend in a slower pace (p=0.055) and greater % OFF (p=0.056) in runners finishing the race with a T GI >40°C. Overall, finish time was influenced by greater variations in pace during the first two miles of the race. In addition, runners who minimized fluid losses and had lower T GI were associated with meeting self-predicted goals. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  12. Relationship between body temperature, weight, and hematological parameters of black tufted-ear marmosets (Callithrix penicillata).

    Science.gov (United States)

    Pereira, Lucas Cardoso; Barros, Marilia

    2016-06-01

    Basal thermal values of captive adult black tufted-ear marmosets (Callithrix penicillata) in a thermoneutral environment were measured via different methods, along with body weight and hematological parameters. Body temperatures were recorded with rectal (RC), subcutaneous (SC) microchip transponder and infrared (left and right) tympanic membrane (TM) thermometries. Thermal values were correlated with body mass and some hematological data. Similar RC and SC temperatures were observed, these being significantly higher than the left and right TM values. SC temperature was positively correlated and in close agreement with RC measurements. Although body temperatures were not influenced by gender, capture time, or body weight, they were correlated with hematological parameters. Thus, body temperatures in this species seem to reflect some of the characteristics of the assessments' location, with SC microchip transponders being a less invasive method to assess body temperature in these small-bodied non-human primates. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. P2X7 receptors in body temperature, locomotor activity, and brain mRNA and lncRNA responses to sleep deprivation.

    Science.gov (United States)

    Davis, Christopher J; Taishi, Ping; Honn, Kimberly A; Koberstein, John N; Krueger, James M

    2016-12-01

    The ionotropic purine type 2X7 receptor (P2X7R) is a nonspecific cation channel implicated in sleep regulation and brain cytokine release. Many endogenous rhythms covary with sleep, including locomotor activity and core body temperature. Furthermore, brain-hypothalamic cytokines and purines play a role in the regulation of these physiological parameters as well as sleep. We hypothesized that these parameters are also affected by the absence of the P2X7 receptor. Herein, we determine spontaneous expression of body temperature and locomotor activity in wild-type (WT) and P2X7R knockout (KO) mice and how they are affected by sleep deprivation (SD). We also compare hypothalamic, hippocampal, and cortical cytokine- and purine-related receptor and enzyme mRNA expressions before and after SD in WT and P2X7RKO mice. Next, in a hypothesis-generating survey of hypothalamic long noncoding (lnc) RNAs, we compare lncRNA expression levels between strains and after SD. During baseline conditions, P2X7RKO mice had attenuated temperature rhythms compared with WT mice, although locomotor activity patterns were similar in both strains. After 6 h of SD, body temperature and locomotion were enhanced to a greater extent in P2X7RKO mice than in WT mice during the initial 2-3 h after SD. Baseline mRNA levels of cortical TNF-α and P2X4R were higher in the KO mice than WT mice. In response to SD, the KO mice failed to increase hypothalamic adenosine deaminase and P2X4R mRNAs. Further, hypothalamic lncRNA expressions varied by strain, and with SD. Current data are consistent with a role for the P2X7R in thermoregulation and lncRNA involvement in purinergic signaling. Copyright © 2016 the American Physiological Society.

  14. [The reaction of human surface and inside body temperature to extreme hypothermia].

    Science.gov (United States)

    Panchenko, O A; Onishchenko, V O; Liakh, Iu Ie

    2011-01-01

    The dynamics of changes in the parameters of the surface and core body temperature under the systematic impact of ultra-low temperature is described in this article. As a source of ultra-low temperature was used (Cryo Therapy Chamber) Zimmer Medizin Systeme firm Zimmer Electromedizin (Germany) (-110 degrees C). Surface and internal body temperature was measured by infrared thermometer immediately before visiting cryochamber and immediately after exiting. In the study conducted 47,464 measurements of body temperature. It was established that the internal temperature of the human body under the influence of ultra-low temperatures in the proposed mode of exposure remains constant, and the surface temperature of the body reduces by an average of 11.57 degrees C. The time frame stabilization of adaptive processes of thermoregulation under the systematic impact of ultra-low temperature was defined in the study.

  15. Body temperatures of fish feeding in the Point Beach thermal discharge

    International Nuclear Information System (INIS)

    Spigarelli, S.A.; Thommes, M.M.

    1974-01-01

    Between April and November, 1973, measurements of internal body temperature were made on 1310 fish caught by fishermen at the Point Beach Nuclear Plant. Records were also made of fish weight, length, and sex and intake and discharge temperatures. A table is presented to show mean monthly body temperatures and numbers of each species. Approximately 76 percent of the measurements were made on rainbow and brown trout, since these species accounted for 74 percent of the catch. Body temperatures of most fish were intermediate between intake and discharge temperatures. Results suggested that each species has rather specific seasonal temperature requirements and that the maximum discharge temperature was normally avoided by feeding fish

  16. AMPK regulates circadian rhythms in a tissue- and isoform-specific manner.

    Directory of Open Access Journals (Sweden)

    Jee-Hyun Um

    2011-03-01

    Full Text Available AMP protein kinase (AMPK plays an important role in food intake and energy metabolism, which are synchronized to the light-dark cycle. In vitro, AMPK affects the circadian rhythm by regulating at least two clock components, CKIα and CRY1, via direct phosphorylation. However, it is not known whether the catalytic activity of AMPK actually regulates circadian rhythm in vivo.THE CATALYTIC SUBUNIT OF AMPK HAS TWO ISOFORMS: α1 and α2. We investigate the circadian rhythm of behavior, physiology and gene expression in AMPKα1-/- and AMPKα2-/- mice. We found that both α1-/- and α2-/- mice are able to maintain a circadian rhythm of activity in dark-dark (DD cycle, but α1-/- mice have a shorter circadian period whereas α2-/- mice showed a tendency toward a slightly longer circadian period. Furthermore, the circadian rhythm of body temperature was dampened in α1-/- mice, but not in α2-/- mice. The circadian pattern of core clock gene expression was severely disrupted in fat in α1-/- mice, but it was severely disrupted in the heart and skeletal muscle of α2-/- mice. Interestingly, other genes that showed circadian pattern of expression were dysreguated in both α1-/- and α2-/- mice. The circadian rhythm of nicotinamide phosphoryl-transferase (NAMPT activity, which converts nicotinamide (NAM to NAD+, is an important regulator of the circadian clock. We found that the NAMPT rhythm was absent in AMPK-deficient tissues and cells.This study demonstrates that the catalytic activity of AMPK regulates circadian rhythm of behavior, energy metabolism and gene expression in isoform- and tissue-specific manners.

  17. The effect of stress on core and peripheral body temperature in humans.

    Science.gov (United States)

    Vinkers, Christiaan H; Penning, Renske; Hellhammer, Juliane; Verster, Joris C; Klaessens, John H G M; Olivier, Berend; Kalkman, Cor J

    2013-09-01

    Even though there are indications that stress influences body temperature in humans, no study has systematically investigated the effects of stress on core and peripheral body temperature. The present study therefore aimed to investigate the effects of acute psychosocial stress on body temperature using different readout measurements. In two independent studies, male and female participants were exposed to a standardized laboratory stress task (the Trier Social Stress Test, TSST) or a non-stressful control task. Core temperature (intestinal and temporal artery) and peripheral temperature (facial and body skin temperature) were measured. Compared to the control condition, stress exposure decreased intestinal temperature but did not affect temporal artery temperature. Stress exposure resulted in changes in skin temperature that followed a gradient-like pattern, with decreases at distal skin locations such as the fingertip and finger base and unchanged skin temperature at proximal regions such as the infra-clavicular area. Stress-induced effects on facial temperature displayed a sex-specific pattern, with decreased nasal skin temperature in females and increased cheek temperature in males. In conclusion, the amplitude and direction of stress-induced temperature changes depend on the site of temperature measurement in humans. This precludes a direct translation of the preclinical stress-induced hyperthermia paradigm, in which core temperature uniformly rises in response to stress to the human situation. Nevertheless, the effects of stress result in consistent temperature changes. Therefore, the present study supports the inclusion of body temperature as a physiological readout parameter of stress in future studies.

  18. Voluntary Running Aids to Maintain High Body Temperature in Rats Bred for High Aerobic Capacity

    Science.gov (United States)

    Karvinen, Sira M.; Silvennoinen, Mika; Ma, Hongqiang; Törmäkangas, Timo; Rantalainen, Timo; Rinnankoski-Tuikka, Rita; Lensu, Sanna; Koch, Lauren G.; Britton, Steven L.; Kainulainen, Heikki

    2016-01-01

    The production of heat, i.e., thermogenesis, is a significant component of the metabolic rate, which in turn affects weight gain and health. Thermogenesis is linked to physical activity (PA) level. However, it is not known whether intrinsic exercise capacity, aging, and long-term voluntary running affect core body temperature. Here we use rat models selectively bred to differ in maximal treadmill endurance running capacity (Low capacity runners, LCR and High capacity Runners, HCR), that as adults are divergent for aerobic exercise capacity, aging, and metabolic disease risk to study the connection between PA and body temperature. Ten high capacity runner (HCR) and ten low capacity runner (LCR) female rats were studied between 9 and 21 months of age. Rectal body temperature of HCR and LCR rats was measured before and after 1-year voluntary running/control intervention to explore the effects of aging and PA. Also, we determined whether injected glucose and spontaneous activity affect the body temperature differently between LCR and HCR rats at 9 vs. 21 months of age. HCRs had on average 1.3°C higher body temperature than LCRs (p body temperature level of HCRs to similar levels with LCRs. The opportunity to run voluntarily had a significant impact on the body temperature of HCRs (p body temperature at a similar level as when at younger age. Compared to LCRs, HCRs were spontaneously more active, had higher relative gastrocnemius muscle mass and higher UCP2, PGC-1α, cyt c, and OXPHOS levels in the skeletal muscle (p body temperature of LCRs. However, glucose injection resulted in a lowering of the body temperature of LCRs (p body temperature compared to rats born with low exercise capacity and disease risk. Voluntary running allowed HCRs to maintain high body temperature during aging, which suggests that high PA level was crucial in maintaining the high body temperature of HCRs. PMID:27504097

  19. Validity of Devices That Assess Body Temperature During Outdoor Exercise in the Heat

    OpenAIRE

    Casa, Douglas J; Becker, Shannon M; Ganio, Matthew S; Brown, Christopher M; Yeargin, Susan W; Roti, Melissa W; Siegler, Jason; Blowers, Julie A; Glaviano, Neal R; Huggins, Robert A; Armstrong, Lawrence E; Maresh, Carl M

    2007-01-01

    Context: Rectal temperature is recommended by the National Athletic Trainers' Association as the criterion standard for recognizing exertional heat stroke, but other body sites commonly are used to measure temperature. Few authors have assessed the validity of the thermometers that measure body temperature at these sites in athletic settings.

  20. Remote long-term registrations of sleep-wake rhythms, core body temperature and activity in marmoset monkeys

    NARCIS (Netherlands)

    Hoffmann, Kerstin; Coolen, Alex; Schlumbohm, Christina; Meerlo, Peter; Fuchs, Eberhard

    2012-01-01

    Initial studies in the day active marmoset monkey (Callithrix jacchus) indicate that the sleep-wake cycle of these non-human primates resembles that of humans and therefore conceivably represent an appropriate model for human sleep. The methods currently employed for sleep studies in marmosets are

  1. Clinical review: Brain-body temperature differences in adults with severe traumatic brain injury

    Science.gov (United States)

    2013-01-01

    Surrogate or 'proxy' measures of brain temperature are used in the routine management of patients with brain damage. The prevailing view is that the brain is 'hotter' than the body. The polarity and magnitude of temperature differences between brain and body, however, remains unclear after severe traumatic brain injury (TBI). The focus of this systematic review is on the adult patient admitted to intensive/neurocritical care with a diagnosis of severe TBI (Glasgow Coma Scale score of less than 8). The review considered studies that measured brain temperature and core body temperature. Articles published in English from the years 1980 to 2012 were searched in databases, CINAHL, PubMed, Scopus, Web of Science, Science Direct, Ovid SP, Mednar and ProQuest Dissertations & Theses Database. For the review, publications of randomised controlled trials, non-randomised controlled trials, before and after studies, cohort studies, case-control studies and descriptive studies were considered for inclusion. Of 2,391 records identified via the search strategies, 37 were retrieved for detailed examination (including two via hand searching). Fifteen were reviewed and assessed for methodological quality. Eleven studies were included in the systematic review providing 15 brain-core body temperature comparisons. The direction of mean brain-body temperature differences was positive (brain higher than body temperature) and negative (brain lower than body temperature). Hypothermia is associated with large brain-body temperature differences. Brain temperature cannot be predicted reliably from core body temperature. Concurrent monitoring of brain and body temperature is recommended in patients where risk of temperature-related neuronal damage is a cause for clinical concern and when deliberate induction of below-normal body temperature is instituted. PMID:23680353

  2. Diet-induced obesity reduces core body temperature across the estrous cycle and pregnancy in the rat.

    Science.gov (United States)

    Crew, Rachael C; Waddell, Brendan J; Maloney, Shane K; Mark, Peter J

    2018-04-16

    Obesity during pregnancy causes adverse maternal and fetal health outcomes and programs offspring for adult-onset diseases, including cardiovascular disease. Obesity also disrupts core body temperature (T c ) regulation in nonpregnant rodents; however, it is unknown whether obesity alters normal maternal T c adaptations to pregnancy. Since T c is influenced by the circadian system, and both obesity and pregnancy alter circadian biology, it was hypothesized that obesity disrupts the normal rhythmic patterns of T c before and during gestation. Obesity was induced by cafeteria (CAF) feeding in female Wistar rats for 8 weeks prior to and during gestation, whereas control (CON) animals had free access to chow. Intraperitoneal temperature loggers measured daily T c profiles throughout the study, while maternal body composition and leptin levels were assessed near term. Daily temperature profiles were examined for rhythmic features (mesor, amplitude and acrophase) by cosine regression analysis. CAF animals exhibited increased fat mass (93%) and associated hyperleptinemia (3.2-fold increase) compared to CON animals. CAF consumption reduced the average T c (by up to 0.29°C) across the estrous cycle and most of pregnancy; however, T c for CAF and CON animals converged toward the end of gestation. Obesity reduced the amplitude of T c rhythms at estrus and proestrus and on day 8 of pregnancy, but increased the amplitude at day 20 of pregnancy. Photoperiod analysis revealed that obesity reduced T c exclusively in the light period during pre-pregnancy but only during the dark period in late gestation. In conclusion, obesity alters rhythmic T c profiles and reduces the magnitude of the T c decline late in rat gestation, which may have implications for maternal health and fetal development.

  3. Circadian Rhythm Sleep Disorders

    Directory of Open Access Journals (Sweden)

    Erhan Akinci

    2016-06-01

    Full Text Available The circadian rhythm sleep disorders define the clinical conditions where sleep and ndash;wake rhythm is disrupted despite optimum environmental and social conditions. They occur as a result of the changes in endogenous circadian hours or non-compatibility of environmental factors or social life with endogenous circadian rhythm. The sleep and ndash;wake rhythm is disrupted continuously or in repeating phases depending on lack of balance between internal and external cycles. This condition leads to functional impairments which cause insomnia, excessive sleepiness or both in people. Application of detailed sleep anamnesis and sleep diary with actigraphy record, if possible, will be sufficient for diagnosis. The treatment aims to align endogenous circadian rhythm with environmental conditions. The purpose of this article is to review pathology, clinical characteristics, diagnosis and treatment of circadian rhythm disorder. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2016; 8(2: 178-189

  4. Body temperature changes of newborns under fluorescent versus LED phototherapy.

    Science.gov (United States)

    Aydemir, Ozge; Soysaldı, Emel; Kale, Yusuf; Kavurt, Sumru; Bas, Ahmet Yagmur; Demirel, Nihal

    2014-08-01

    To determine changes in body temperature (BT) of hyperbilirubinemic newborns under conventional phototherapy with fluorescent lamps and light emitting diodes (LED) at different irradiances. Otherwise healthy newborn infants >34 wk gestational age (GA) hospitalized for indirect hyperbilirubinemia, requiring phototherapy in the first 10 d of life were enrolled. Infants who received conventional phototherapy with fluorescent lamps (10-15 μW/cm(2)/nm irradiance) were defined as group 1, LED phototherapy of 26-60 μW/cm(2)/nm irradiance as group 2, and LED phototherapy of 60-120 μW/cm(2)/nm irradiance as group 3. Primary outcome measure was mean BT which was defined as arithmetical mean of axillary BT measured at 2 h intervals during the first day of phototherapy. Thirty patients were enroled in each group. Mean birth weight and GA of the total cohort was 2800 ± 530 g and 36.6 ± 2 wk, respectively. Baseline demographic variables and serum total bilirubin levels were similar among groups. Mean BT was 36.7 ± 0.1 °C in group 1, 36.6 ± 0.2 °C in group 2, 37.7 ± 0.2 °C in group 3. Mean BT was higher in group 3 compared to group 1 (p phototherapy all the patients in group 3 had at least one BT measurement ≥ 37.5 °C and 77 % had BT ≥ 38 °C. Only one patient in group 2 had BT ≥ 37.5 °C which was also ≥ 38 °C. During phototherapy all BT measurements were LED phototherapy of ≥ 60 μW/cm(2)/nm intensity significantly increases BT in hyperbilirubinemic newborns.

  5. Article comprising a garment or other textile structure for use in controlling body temperature

    Science.gov (United States)

    Butzer, Melissa J.

    2000-01-01

    There is disclosed an article for use in cooling body temperature which comprises a garment having a coat and pant, with each having a body section adapted to receive a portion of the torso of the wearer and extensions from the body section to receive the wearer's limbs. The garment includes a system for circulating temperature controlling fluid from a suitable source through patches removably received in pockets in each of body section and extensions.

  6. The impact of high temperatures on foraging behaviour and body ...

    African Journals Online (AJOL)

    High temperatures can pose significant thermoregulation challenges for endotherms, and determining how individual species respond to high temperatures will be important for predicting the impact of global warming on wild populations. Animals can adjust their behaviour or physiology to cope with higher temperatures, ...

  7. Temperature distribution in the human body under various conditions of induced hyperthermia

    Science.gov (United States)

    Korobko, O. V.; Perelman, T. L.; Fradkin, S. Z.

    1977-01-01

    A mathematical model based on heat balance equations was developed for studying temperature distribution in the human body under deep hyperthermia which is often induced in the treatment of malignant tumors. The model yields results which are in satisfactory agreement with experimental data. The distribution of temperature under various conditions of induced hyperthermia, i.e. as a function of water temperature and supply rate, is examined on the basis of temperature distribution curves in various body zones.

  8. Influence of elevated body temperature on circulating immunoglobulin-secreting cells

    DEFF Research Database (Denmark)

    Kappel, M; Barington, T; Gyhrs, A

    1995-01-01

    This work was designed to investigate the effect of in vivo hyperthermia in man on circulating immunoglobulin-secreting cells. Eight healthy male volunteers were immersed into a hot waterbath (WI) (water temperature 39.5 degrees C) for 2 h, whereby their body temperature rose to 39.5 degrees C....... On another occasion they served as their own controls, being immersed into thermoneutral water (water temperature 34.5 degrees C) for 2 h. Blood samples were drawn before immersion, at body temperatures of 38, 39 and 39.5 degrees C, as well as 2 h after WI when their body temperatures were normalized...

  9. Voluntary Running Aids to Maintain High Body Temperature in Rats Bred for High Aerobic Capacity.

    Science.gov (United States)

    Karvinen, Sira M; Silvennoinen, Mika; Ma, Hongqiang; Törmäkangas, Timo; Rantalainen, Timo; Rinnankoski-Tuikka, Rita; Lensu, Sanna; Koch, Lauren G; Britton, Steven L; Kainulainen, Heikki

    2016-01-01

    The production of heat, i.e., thermogenesis, is a significant component of the metabolic rate, which in turn affects weight gain and health. Thermogenesis is linked to physical activity (PA) level. However, it is not known whether intrinsic exercise capacity, aging, and long-term voluntary running affect core body temperature. Here we use rat models selectively bred to differ in maximal treadmill endurance running capacity (Low capacity runners, LCR and High capacity Runners, HCR), that as adults are divergent for aerobic exercise capacity, aging, and metabolic disease risk to study the connection between PA and body temperature. Ten high capacity runner (HCR) and ten low capacity runner (LCR) female rats were studied between 9 and 21 months of age. Rectal body temperature of HCR and LCR rats was measured before and after 1-year voluntary running/control intervention to explore the effects of aging and PA. Also, we determined whether injected glucose and spontaneous activity affect the body temperature differently between LCR and HCR rats at 9 vs. 21 months of age. HCRs had on average 1.3°C higher body temperature than LCRs (p temperature level of HCRs to similar levels with LCRs. The opportunity to run voluntarily had a significant impact on the body temperature of HCRs (p temperature at a similar level as when at younger age. Compared to LCRs, HCRs were spontaneously more active, had higher relative gastrocnemius muscle mass and higher UCP2, PGC-1α, cyt c, and OXPHOS levels in the skeletal muscle (p temperature of LCRs. However, glucose injection resulted in a lowering of the body temperature of LCRs (p high intrinsic capacity for aerobic exercise and better health have higher body temperature compared to rats born with low exercise capacity and disease risk. Voluntary running allowed HCRs to maintain high body temperature during aging, which suggests that high PA level was crucial in maintaining the high body temperature of HCRs.

  10. FDTD analysis of body-core temperature elevation in children and adults for whole-body exposure

    Science.gov (United States)

    Hirata, Akimasa; Asano, Takayuki; Fujiwara, Osamu

    2008-09-01

    The temperature elevations in anatomically based human phantoms of an adult and a 3-year-old child were calculated for radio-frequency whole-body exposure. Thermoregulation in children, however, has not yet been clarified. In the present study, we developed a computational thermal model of a child that is reasonable for simulating body-core temperature elevation. Comparison of measured and simulated temperatures revealed thermoregulation in children to be similar to that of adults. Based on this finding, we calculated the body-core temperature elevation in a 3-year-old child and an adult for plane-wave exposure at the basic restriction in the international guidelines. The body-core temperature elevation in the 3-year-old child phantom was 0.03 °C at a whole-body-averaged specific absorption rate of 0.08 W kg-1, which was 35% smaller than in the adult female. This difference is attributed to the child's higher body surface area-to-mass ratio.

  11. FDTD analysis of body-core temperature elevation in children and adults for whole-body exposure

    International Nuclear Information System (INIS)

    Hirata, Akimasa; Asano, Takayuki; Fujiwara, Osamu

    2008-01-01

    The temperature elevations in anatomically based human phantoms of an adult and a 3-year-old child were calculated for radio-frequency whole-body exposure. Thermoregulation in children, however, has not yet been clarified. In the present study, we developed a computational thermal model of a child that is reasonable for simulating body-core temperature elevation. Comparison of measured and simulated temperatures revealed thermoregulation in children to be similar to that of adults. Based on this finding, we calculated the body-core temperature elevation in a 3-year-old child and an adult for plane-wave exposure at the basic restriction in the international guidelines. The body-core temperature elevation in the 3-year-old child phantom was 0.03 deg. C at a whole-body-averaged specific absorption rate of 0.08 W kg -1 , which was 35% smaller than in the adult female. This difference is attributed to the child's higher body surface area-to-mass ratio

  12. FDTD analysis of body-core temperature elevation in children and adults for whole-body exposure

    Energy Technology Data Exchange (ETDEWEB)

    Hirata, Akimasa; Asano, Takayuki; Fujiwara, Osamu [Department of Computer Science and Engineering, Nagoya Institute of Technology (Japan)], E-mail: ahirata@nitech.ac.jp

    2008-09-21

    The temperature elevations in anatomically based human phantoms of an adult and a 3-year-old child were calculated for radio-frequency whole-body exposure. Thermoregulation in children, however, has not yet been clarified. In the present study, we developed a computational thermal model of a child that is reasonable for simulating body-core temperature elevation. Comparison of measured and simulated temperatures revealed thermoregulation in children to be similar to that of adults. Based on this finding, we calculated the body-core temperature elevation in a 3-year-old child and an adult for plane-wave exposure at the basic restriction in the international guidelines. The body-core temperature elevation in the 3-year-old child phantom was 0.03 deg. C at a whole-body-averaged specific absorption rate of 0.08 W kg{sup -1}, which was 35% smaller than in the adult female. This difference is attributed to the child's higher body surface area-to-mass ratio.

  13. Ambient Light Intensity, Actigraphy, Sleep and Respiration, Circadian Temperature and Melatonin Rhythms and Daytime Performance of Crew Members During Space Flight on STS-90 and STS-95 Missions

    Science.gov (United States)

    Czeisler, Charles A.; Dijk, D.-J.; Neri, D. F.; Hughes, R. J.; Ronda, J. M.; Wyatt, J. K.; West, J. B.; Prisk, G. K.; Elliott, A. R.; Young, L. R.

    1999-01-01

    Sleep disruption and associated waking sleepiness and fatigue are common during space flight. A survey of 58 crew members from nine space shuttle missions revealed that most suffered from sleep disruption, and reportedly slept an average of only 6.1 hours per day of flight as compared to an average of 7.9 hours per day on the ground. Nineteen percent of crewmembers on single shift missions and 50 percent of the crewmembers in dual shift operations reported sleeping pill usage (benzodiazepines) during their missions. Benzodiazepines are effective as hypnotics, however, not without adverse side effects including carryover sedation and performance impairment, anterograde amnesia, and alterations in sleep EEG. Our preliminary ground-based data suggest that pre-sleep administration of 0.3 mg of the pineal hormone melatonin may have the acute hypnotic properties needed for treating the sleep disruption of space flight without producing the adverse side effects associated with benzodiazepines. We hypothesize that pre-sleep administration of melatonin will result in decreased sleep latency, reduced nocturnal sleep disruption, improved sleep efficiency, and enhanced next-day alertness and cognitive performance both in ground-based simulations and during the space shuttle missions. Specifically, we have carried out experiments in which: (1) ambient light intensity aboard the space shuttle is assessed during flight; (2) the impact of space flight on sleep (assessed polysomnographically and actigraphically), respiration during sleep, circadian temperature and melatonin rhythms, waking neurobehavioral alertness and performance is assessed in crew members of the Neurolab and STS-95 missions; (3) the effectiveness of melatonin as a hypnotic is assessed independently of its effects on the phase of the endogenous circadian pacemaker in ground-based studies, using a powerful experimental model of the dyssomnia of space flight; (4) the effectiveness of melatonin as a hypnotic is

  14. THERMAL COMFORT FOR REQUIRED BODY TEMPERATURES AND AMBIENT CONDITIONS

    OpenAIRE

    KAYNAKLI, Ömer; YAMANKARADENİZ, Recep

    2010-01-01

    ABSTRACTIn industrialized countries about 90 % of the time is spent indoors. The environmental parameters affecting indoor thermal comfort are air temperature, humidity, air velocity and mean radiant temperature. In assessing thermal environment, besides these environmental parameters, we should also consider some personal parameters such as clothing and human activity. In this study, we tried to determine the thermal comfort factors with reference to required skin temperature (tsk,req) and s...

  15. Isotopic ordering in eggshells reflects body temperatures and suggests differing thermophysiology in two Cretaceous dinosaurs

    Science.gov (United States)

    Eagle, Robert A.; Enriquez, Marcus; Grellet-Tinner, Gerald; Pérez-Huerta, Alberto; Hu, David; Tütken, Thomas; Montanari, Shaena; Loyd, Sean J.; Ramirez, Pedro; Tripati, Aradhna K.; Kohn, Matthew J.; Cerling, Thure E.; Chiappe, Luis M.; Eiler, John M.

    2015-10-01

    Our understanding of the evolutionary transitions leading to the modern endothermic state of birds and mammals is incomplete, partly because tools available to study the thermophysiology of extinct vertebrates are limited. Here we show that clumped isotope analysis of eggshells can be used to determine body temperatures of females during periods of ovulation. Late Cretaceous titanosaurid eggshells yield temperatures similar to large modern endotherms. In contrast, oviraptorid eggshells yield temperatures lower than most modern endotherms but ~6 °C higher than co-occurring abiogenic carbonates, implying that this taxon did not have thermoregulation comparable to modern birds, but was able to elevate its body temperature above environmental temperatures. Therefore, we observe no strong evidence for end-member ectothermy or endothermy in the species examined. Body temperatures for these two species indicate that variable thermoregulation likely existed among the non-avian dinosaurs and that not all dinosaurs had body temperatures in the range of that seen in modern birds.

  16. Influence of the Environment on Body Temperature of Racing Greyhounds.

    Science.gov (United States)

    McNicholl, Jane; Howarth, Gordon S; Hazel, Susan J

    2016-01-01

    Heat strain is a potential risk factor for racing greyhounds in hot climates. However, there have been limited studies into the incidence of heat strain (when excess heat causes physiological or pathological effects) in racing greyhounds. The aim of this study was to determine if heat strain occurs in racing greyhounds, and, if so, whether environmental factors (e.g., ambient temperature and relative humidity) or dog-related factors (e.g., sex, bodyweight, color) are associated with the risk of heat strain. A total of 229 greyhounds were included in over 46 race meetings and seven different race venues in South Australia, Australia. Rectal temperatures of dogs were measured pre- and postrace and urine samples collected for analysis of myoglobinuria. Ambient temperature at race times ranged between 11.0 and 40.8°C and relative humidity ranged from 17 to 92%. There was a mean increase in greyhound rectal temperature of 2.1°C (range 1.1-3.1°C). A small but significant association was present between ambient temperature and increase in rectal temperature (r (2) = 0.033, P = 0.007). The mean ambient temperature at race time, of dogs with postrace rectal temperature of or exceeding 41.5°C, was significantly greater than at race time of dogs with a postrace rectal temperature ≤41.5°C (31.2 vs. 27.3°C, respectively, P = 0.004). When the ambient temperature reached 38(o)C, over one-third (39%) of dogs had a rectal temperature >41.5°C. Over half of postrace urine samples were positive by Dipstick reading for hemoglobin/myoglobin, and of 77 urine samples positive for Dipstick readings, 95% were positive for myoglobin. However, urinary myoglobin levels were not associated with ambient temperature or postrace rectal temperatures. The mean increase in rectal temperature was greater in dark (black, blue, brindle) than light (fawn and white) colored greyhounds. The results suggest heat strain occurs in racing greyhounds, evidenced by postrace rectal

  17. DISTURBANCES OF BIOLOGICAL RHYTHMS IN A RAT CHRONIC MILD STRESS MODEL OF DEPRESSION

    DEFF Research Database (Denmark)

    Christiansen, Sofie; Wiborg, Ove; Bouzinova, Elena

    Aim: The focus of this project is to identify biomarkers related to circadian disturbances in major depressive disorder. Background: A large body of clinical data from depressed individuals showed that sleep, temperature, hormones, physiological states and moodchanges are consistent with disturba......Aim: The focus of this project is to identify biomarkers related to circadian disturbances in major depressive disorder. Background: A large body of clinical data from depressed individuals showed that sleep, temperature, hormones, physiological states and moodchanges are consistent...... with disturbances in circadian related processes. The suprachiasmatic nucleus (SCN) is well known for its function as the master clock and regulates several circadian systems by clock genes expression. In addition to central expression, peripheral clock genes have been found. Methods: The study is based on a highly...... rhythm. Conclusion: Abnormalities in circadian rhythms, both centrally and peripherally, are related to depression-like state in the CMS model. Research support: This study is supported by Aarhus University and Illum fondet...

  18. Is there an association between body temperature and serum lactate levels in hip fracture patients?

    Science.gov (United States)

    Murtuza, F; Farrier, A J; Venkatesan, M; Smith, R; Khan, A; Uzoigwe, C E; Chami, G

    2015-10-01

    Introduction Hyperlactataemia is associated with adverse outcomes in trauma cases. It is thought to be the result of anaerobic respiration during hypoperfusion. This produces much less energy than complete aerobic glycolysis. Low body temperature in the injured patient carries an equally poor prognosis. Significant amounts of energy are expended in maintaining euthermia. Consequently, there may be a link between lactate levels and dysthermia. Hyperlactataemia may be indicative of inefficient energy production and therefore insufficient energy to maintain euthermia. Alternatively, significant amounts of available oxygen may be sequestered in thermoregulation, resulting in anaerobic respiration and lactate production. Our study investigated whether there is an association between lactate levels and admission body temperature in hip fracture patients. Furthermore, it looked at whether there is a difference in the mean lactate levels between hip fracture patients with low (37.5°C) body temperature on admission, and for patients who have low body temperature, whether there is a progressive rise in serum lactate levels as body temperature falls. Methods The admission temperature and serum lactate of 1,162 patients presenting with hip fracture were recorded. Patients were divided into the euthermic (body temperature 36.5-37.5°C), the pyrexial (>37.5°C) and those with low body temperature (body temperature were compared. Results There was a significant difference in age between the three body temperature groups (p=0.007). The pyrexial cohort was younger than the low body temperature group (mean: 78 vs 82 years). Those with low body temperature had a higher mean lactate level than the euthermic (2.2mmol/l vs 2.0mmol/l, p=0.03). However, there was no progressive rise in serum lactate level as admission temperature fell. Conclusions The findings suggest that in hip fracture patients, the body attempts initially to maintain euthermia, incurring an oxygen debt. This would

  19. Decreases in beetle body size linked to climate change and warming temperatures.

    Science.gov (United States)

    Tseng, Michelle; Kaur, Katrina M; Soleimani Pari, Sina; Sarai, Karnjit; Chan, Denessa; Yao, Christine H; Porto, Paula; Toor, Anmol; Toor, Harpawantaj S; Fograscher, Katrina

    2018-01-30

    Body size is a fundamental ecological trait and is correlated with population dynamics, community structure and function, and ecosystem fluxes. Laboratory data from broad taxonomic groups suggest that a widespread response to a warming world may be an overall decrease in organism body size. However, given the myriad of biotic and abiotic factors that can also influence organism body size in the wild, it is unclear whether results from these laboratory assays hold in nature. Here we use datasets spanning 30 to 100 years to examine whether the body size of wild-caught beetles has changed over time, whether body size changes are correlated with increased temperatures, and we frame these results using predictions derived from a quantitative review of laboratory responses of 22 beetle species to temperature. We found that 95% of laboratory-reared beetles decreased in size with increased rearing temperature, with larger-bodied species shrinking disproportionately more than smaller-bodied beetles. In addition, the museum datasets revealed that larger-bodied beetle species have decreased in size over time, that mean beetle body size explains much of the interspecific variation in beetle responses to temperature, and that long-term beetle size changes are explained by increases in autumn temperature and decreases in spring temperature in this region. Our data demonstrate that the relationship between body size and temperature of wild-caught beetles matches relatively well with results from laboratory studies, and that variation in this relationship is largely explained by interspecific variation in mean beetle body size. This long-term beetle dataset is one of the most comprehensive arthropod body size datasets compiled to date, it improves predictions regarding the shrinking of organisms with global climate change, and together with the meta-analysis data, call for new hypotheses to explain why larger-bodied organisms may be more sensitive to temperature. © 2018 The

  20. The effects of a tranquilizer on body temperature.

    Science.gov (United States)

    1963-10-01

    Four young adult mongrel dogs were exposed twice untranquilized to each of three environmental temperatures: 4.4C, 23.9C, and 37.8C and exposed twice tranquilized with 2.2 mg/Kg propiopromazine hydrochloride. Rectal temperatures were monitored ...

  1. Temporal profile of body temperature in acute ischemic stroke: Relation to infarct size and outcome

    NARCIS (Netherlands)

    M. Geurts (Marjolein); Scheijmans, F.E.V. (Féline E.V.); T. van Seeters (Tom); G.J. Biessels; L.J. Kappelle (Jaap); B.K. Velthuis (Birgitta K.); H.B. van der Worp (Bart); C.B. Majoie (Charles); Y.B.W.E.M. Roos (Yvo); L.E.M. Duijm (Lucien); K. Keizer (Koos); A. van der Lugt (Aad); D.W.J. Dippel (Diederik); Greve, D. (Droogh-de); H.P. Bienfait (Henri); M.A.A. van Walderveen (Marianne); M.J.H. Wermer (Marieke); G.J. Lycklama à Nijeholt (Geert); J. Boiten (Jelis); A. Duyndam (Anita); V.I.H. Kwa; F.J. Meijer (F.); E.J. van Dijk (Ewoud); A.M. Kesselring (Anouk); J. Hofmeijer; J.A. Vos (Jan Albert); W.J. Schonewille (Wouter); W.J. van Rooij (W.); P.L.M. de Kort (Paul); C.C. Pleiter (C.); S.L.M. Bakker (Stef); Bot, J.; M.C. Visser (Marieke); B.K. Velthuis (Birgitta); I.C. van der Schaaf (Irene); J.W. Dankbaar (Jan); W.P. Mali (Willem); van Seeters, T.; A.D. Horsch (Alexander D.); J.M. Niesten (Joris); G.J. Biessels (Geert Jan); L.J. Kappelle (Jaap); J.S.K. Luitse; Y. van der Graaf (Yolanda)

    2016-01-01

    textabstractBackground: High body temperatures after ischemic stroke have been associated with larger infarct size, but the temporal profile of this relation is unknown. We assess the relation between temporal profile of body temperature and infarct size and functional outcome in patients with acute

  2. Admission body temperature predicts long-term mortality after acute stroke

    DEFF Research Database (Denmark)

    Kammersgaard, L P; Jørgensen, H S; Rungby, Jørgen

    2002-01-01

    Body temperature is considered crucial in the management of acute stroke patients. Recently hypothermia applied as a therapy for stroke has been demonstrated to be feasible and safe in acute stroke patients. In the present study, we investigated the predictive role of admission body temperature...

  3. The effect of a change in sleep-wakefulness timing, bright light and physical exercise interventions on 24-hour patterns of performance, mood and body temperature.

    Science.gov (United States)

    Iskra-Golec, I; Fafrowicz, M; Marek, T; Costa, G; Folkard, S; Foret, J; Kundi, M; Smith, L

    2001-12-01

    Experiments consisting of baseline, bright light and physical exercise studies were carried out to compare the effect of a 9-hour delay in sleep-wakefulness timing, and the effects of bright light and physical exercise interventions on 24-hour patterns of performance, mood and body temperature were examined. Each study comprised a 24-hour constant routine at the beginning followed by 3 night shifts and 24-hour constant routine at the end. Performance on tasks differing in cognitive load, mood and body temperature was measured during each constant routine and the interventions were applied during the night shifts. The 24-hour pattern of alertness and performance on the tasks with low cognitive load in post-treatment conditions followed the change in sleep-wakefulness timing while more cognitively loaded tasks tended to show a reverse trend when compared to pre-treatment conditions. There was a phase delay around 4 hours in circadian rhythms of body temperature in post-treatment conditions.

  4. Regulation of the peripheral body temperature by foods: a temperature decrease induced by the Japanese persimmon (kaki, Diospyros kaki).

    Science.gov (United States)

    Hibino, Gaku; Nadamoto, Tomonori; Fujisawa, Fumiko; Fushiki, Tohru

    2003-01-01

    We investigated whether the ingestion of the Japanese persimmon (kaki, Diospyros kaki) could lower the human peripheral body temperature. It was found that the temperatures recorded at the foot and wrist were depressed after kaki consumption compared to after the same amount of water consumption. The effects of ingesting freeze-dried kaki and eating a cookie (as its nutritional counterpart) containing the same amount of carbohydrate, protein, fat, and water were compared. A similar temperature-reducing effect of kaki was observed. The recovery of finger temperature after soaking the finger in ice-cooled water was also studied. The temperature recovery was delayed after kaki consumption. It was thus quantitatively demonstrated that ingesting kaki indeed had the effect of lowering (or repressing the rise) of the peripheral human body temperature, as has been traditionally believed in China for many hundreds of years.

  5. Skin sites to predict deep-body temperature while wearing firefighters' personal protective equipment during periodical changes in air temperature.

    Science.gov (United States)

    Kim, Siyeon; Lee, Joo-Young

    2016-04-01

    The aim of this study was to investigate stable and valid measurement sites of skin temperatures as a non-invasive variable to predict deep-body temperature while wearing firefighters' personal protective equipment (PPE) during air temperature changes. Eight male firefighters participated in an experiment which consisted of 60-min exercise and 10-min recovery while wearing PPE without self-contained breathing apparatus (7.75 kg in total PPE mass). Air temperature was periodically fluctuated from 29.5 to 35.5 °C with an amplitude of 6 °C. Rectal temperature was chosen as a deep-body temperature, and 12 skin temperatures were recorded. The results showed that the forehead and chest were identified as the most valid sites to predict rectal temperature (R(2) = 0.826 and 0.824, respectively) in an environment with periodically fluctuated air temperatures. This study suggests that particular skin temperatures are valid as a non-invasive variable when predicting rectal temperature of an individual wearing PPE in changing ambient temperatures. Practitioner Summary: This study should offer assistance for developing a more reliable indirect indicating system of individual heat strain for firefighters in real time, which can be used practically as a precaution of firefighters' heat-related illness and utilised along with physiological monitoring.

  6. Extracellular hyperosmolality and body temperature during physical exercise in dogs

    Science.gov (United States)

    Kozlowski, S.; Greenleaf, J. E.; Turlejska, E.; Nazar, K.

    1980-01-01

    The purpose of this study was to test the hypothesis that thermoregulation during exercise can be affected by extracellular fluid hyperosmolality without changing the plasma Na(+) concentration. The effects of preexercise venous infusions of hypertonic mannitol and NaCl solutions on rectal temperature responses were compared in dogs running at moderate intensity for 60 min on a treadmill. Plasma Na(+) concentration was increased by 12 meq after NaCl infusion, and decreased by 9 meq after mannitol infusion. Both infusions increased plasma by 15 mosmol/kg. After both infusions, rectal temperature was essentially constant during 60 min rest. However, compared with the noninfusion exercise increase in osmolality of 1.3 C, rectal temperature increased by 1.9 C after both postinfusion exercise experiments. It was concluded that inducing extracellular hyperosmolality, without elevating plasma, can induce excessive increases in rectal temperature during exericse but not at rest.

  7. Gravity and thermoregulation: metabolic changes and circadian rhythms

    Science.gov (United States)

    Robinson, E. L.; Fuller, C. A.

    2000-01-01

    Gravity appears to alter thermoregulation through changes in both the regulated level of body temperature and the rhythmic organization of temperature regulation. Gravity has been hypothesized to have an associated metabolic cost. Increased resting energy expenditure and dietary intake have been observed in animals during centrifuge experiments at hypergravity. Thus far, only animals have shown a corresponding reduction in metabolism in microgravity. Altered heat loss has been proposed as a response to altered gravitational environments, but remains documented only as changes in skin temperature. Changes in circadian timing, including the body temperature rhythm, have been shown in both hypergravity and microgravity, and probably contribute to alterations in sleep and performance. Changes in body temperature regulation may result from circadian disturbance, from the direct or indirect actions of gravity on the regulated temperature, or from changes in thermoregulatory effectors (heat production and heat loss) due to altered gravitational load and convective changes. To date, however, we have little data on the underlying thermoregulatory changes in altered gravity, and thus the precise mechanisms by which gravity alters temperature regulation remain largely unknown.

  8. Reduced one-body density matrix of Tonks–Girardeau gas at finite temperature

    International Nuclear Information System (INIS)

    Fu Xiao-Chen; Hao Ya-Jiang

    2015-01-01

    With thermal Bose–Fermi mapping method, we investigate the Tonks–Girardeau gas at finite temperature. It is shown that at low temperature, the Tonks gas displays the Fermi-like density profiles, and with the increase in temperature, the Tonks gas distributes in wider region. The reduced one-body density matrix is diagonal dominant in the whole temperature region, and the off-diagonal elements shall vanish rapidly with the deviation from the diagonal part at high temperature. (paper)

  9. Effect of Chronic Hypercapnia on Body Temperature Regulation

    Science.gov (United States)

    1974-08-01

    temperature in rats at ambient room temperatures of 24 - 28° C. Similar effects have been demon- strated in cats, mice, dogs and rabbits6»7󈨍... glycolysis was found to be reduced 55% during maximal extra- cellular acidosis and showed a partial recovery during the later phase of ex- posure to...as demonstrated by Nahas-and Poyart^T" They observed that adrenalin-induced lipolysis and calorigenesis is inhibited in dogs when breathing a

  10. Effects of meal size, meal type, and body temperature on the specific dynamic action of anurans.

    Science.gov (United States)

    Secor, Stephen M; Wooten, Jessica A; Cox, Christian L

    2007-02-01

    Specific dynamic action (SDA), the increase in metabolism stemming from meal digestion and assimilation, varies as a function of meal size, meal type, and body temperature. To test predictions of these three determinants of SDA, we quantified and compared the SDA responses of nine species of anurans, Bombina orientalis, Bufo cognatus, Ceratophrys ornata, Dyscophus antongilli, Hyla cinerea, Kassina maculata, Kassina senegalensis, Pyxicephalus adspersus, and Rana catesbeiana subjected to meal size, meal type, and body temperature treatments. Over a three to seven-fold increase in meal size, anurans experienced predicted increases in postprandial rates of oxygen consumption (VO(2)) the duration of elevated VO(2) and SDA. Meal type had a significant influence on the SDA response, as the digestion and assimilation of hard-bodied, chitinous crickets, mealworms, and superworms required 76% more energy than the digestion and assimilation of soft-bodied earthworms, waxworms, and neonate rodents. Body temperature largely effected the shape of the postprandial metabolic profile; peak VO(2) increased and the duration of the response decreased with an increase in body temperature. Variation in body temperature did not significantly alter SDA for four species, whereas both H. cinerea and R. catesbeiana experienced significant increases in SDA with body temperature. For 13 or 15 species of anurans ranging in mass from 2.4 to 270 g, SMR, postprandial peak VO(2) and SDA scaled with body mass (log-log) with mass exponents of 0.79, 0.93, and 1.05, respectively.

  11. Integration of body temperature into the analysis of energy expenditure in the mouse.

    Science.gov (United States)

    Abreu-Vieira, Gustavo; Xiao, Cuiying; Gavrilova, Oksana; Reitman, Marc L

    2015-06-01

    We quantified the effect of environmental temperature on mouse energy homeostasis and body temperature. The effect of environmental temperature (4-33 °C) on body temperature, energy expenditure, physical activity, and food intake in various mice (chow diet, high-fat diet, Brs3 (-/y) , lipodystrophic) was measured using continuous monitoring. Body temperature depended most on circadian phase and physical activity, but also on environmental temperature. The amounts of energy expenditure due to basal metabolic rate (calculated via a novel method), thermic effect of food, physical activity, and cold-induced thermogenesis were determined as a function of environmental temperature. The measured resting defended body temperature matched that calculated from the energy expenditure using Fourier's law of heat conduction. Mice defended a higher body temperature during physical activity. The cost of the warmer body temperature during the active phase is 4-16% of total daily energy expenditure. Parameters measured in diet-induced obese and Brs3 (-/y) mice were similar to controls. The high post-mortem heat conductance demonstrates that most insulation in mice is via physiological mechanisms. At 22 °C, cold-induced thermogenesis is ∼120% of basal metabolic rate. The higher body temperature during physical activity is due to a higher set point, not simply increased heat generation during exercise. Most insulation in mice is via physiological mechanisms, with little from fur or fat. Our analysis suggests that the definition of the upper limit of the thermoneutral zone should be re-considered. Measuring body temperature informs interpretation of energy expenditure data and improves the predictiveness and utility of the mouse to model human energy homeostasis.

  12. [The temperature and temperature gradients distribution in the rabbit body thermophysical model with evaporation of moisture from its surface].

    Science.gov (United States)

    Rumiantsev, G V

    2004-04-01

    On created in laboratory heat-physical model of a rabbit body reflecting basic heat-physical parameters of the body such as: weight, size of a relative surface, heat absorption and heat conduction, heat capacity etc., a change of radial distribution of temperature and size was found across a superficial layer of evaporation of water from its surface, that simulates sweating, with various ratio of environmental temperature and capacity of electrical heater simulating heat production in animal. The experiments have shown that with evaporation of moisture from a surface of model in all investigated cases, there is an increase of superficial layer of body of a temperature gradient and simultaneous decrease of temperature of a model inside and on the surface. It seems that, with evaporation of a moisture from a surface of a body, the size of a temperature gradient in a thin superficial layer dependent in our experiments on capacity for heat production and environmental temperature, is increased and can be used in a live organism for definition of change in general heat content of the body with the purpose of maintenance of its thermal balance with environment.

  13. Thermal equilibrium and temperature differences among body regions in European plethodontid salamanders.

    Science.gov (United States)

    Lunghi, Enrico; Manenti, Raoul; Canciani, Giancarlo; Scarì, Giorgio; Pennati, Roberta; Ficetola, Gentile Francesco

    2016-08-01

    Information on species thermal physiology is extremely important to understand species responses to environmental heterogeneity and changes. Thermography is an emerging technology that allows high resolution and accurate measurement of body temperature, but until now it has not been used to study thermal physiology of amphibians in the wild. Hydromantes terrestrial salamanders are strongly depending on ambient temperature for their activity and gas exchanges, but information on their body temperature is extremely limited. In this study we tested if Hydromantes salamanders are thermoconform, we assessed whether there are temperature differences among body regions, and evaluated the time required to reach the thermal equilibrium. During summers of 2014 and 2015 we analysed 56 salamanders (Hydromantes ambrosii and Hydromantes italicus) using infrared thermocamera. We photographed salamanders at the moment in which we found them and 1, 2, 3, 4, 5 and 15min after having kept them in the hands. Body temperature was equal to air temperature; salamanders attained the equilibrium with air temperature in about 8min, the time required to reach equilibrium was longer in individuals with large body size. We detected small temperature differences between body parts, the head being slightly warmer than the body and the tail (mean difference: 0.05°C). These salamanders quickly reach the equilibrium with the environment, thus microhabitat measurement allows obtaining accurate information on their tolerance limits. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Rhythm in language acquisition.

    Science.gov (United States)

    Langus, Alan; Mehler, Jacques; Nespor, Marina

    2017-10-01

    Spoken language is governed by rhythm. Linguistic rhythm is hierarchical and the rhythmic hierarchy partially mimics the prosodic as well as the morpho-syntactic hierarchy of spoken language. It can thus provide learners with cues about the structure of the language they are acquiring. We identify three universal levels of linguistic rhythm - the segmental level, the level of the metrical feet and the phonological phrase level - and discuss why primary lexical stress is not rhythmic. We survey experimental evidence on rhythm perception in young infants and native speakers of various languages to determine the properties of linguistic rhythm that are present at birth, those that mature during the first year of life and those that are shaped by the linguistic environment of language learners. We conclude with a discussion of the major gaps in current knowledge on linguistic rhythm and highlight areas of interest for future research that are most likely to yield significant insights into the nature, the perception, and the usefulness of linguistic rhythm. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Rats with minimal hepatic encephalopathy show reduced cGMP-dependent protein kinase activity in hypothalamus correlating with circadian rhythms alterations.

    Science.gov (United States)

    Felipo, Vicente; Piedrafita, Blanca; Barios, Juan A; Agustí, Ana; Ahabrach, Hanan; Romero-Vives, María; Barrio, Luis C; Rey, Beatriz; Gaztelu, Jose M; Llansola, Marta

    2015-01-01

    Patients with liver cirrhosis show disturbances in sleep and in its circadian rhythms which are an early sign of minimal hepatic encephalopathy (MHE). The mechanisms of these disturbances are poorly understood. Rats with porta-caval shunt (PCS), a model of MHE, show sleep disturbances reproducing those of cirrhotic patients. The aims of this work were to characterize the alterations in circadian rhythms in PCS rats and analyze the underlying mechanisms. To reach these aims, we analyzed in control and PCS rats: (a) daily rhythms of spontaneous and rewarding activity and of temperature, (b) timing of the onset of activity following turning-off the light, (c) synchronization to light after a phase advance and (d) the molecular mechanisms contributing to these alterations in circadian rhythms. PCS rats show altered circadian rhythms of spontaneous and rewarding activities (wheel running). PCS rats show more rest bouts during the active phase, more errors in the onset of motor activity and need less time to re-synchronize after a phase advance than control rats. Circadian rhythm of body temperature is also slightly altered in PCS rats. The internal period length (tau) of circadian rhythm of motor activity is longer in PCS rats. We analyzed some mechanisms by which hypothalamus modulate circadian rhythms. PCS rats show increased content of cGMP in hypothalamus while the activity of cGMP-dependent protein kinase was reduced by 41% compared to control rats. Altered cGMP-PKG pathway in hypothalamus would contribute to altered circadian rhythms and synchronization to light.

  16. Prediction of human core body temperature using non-invasive measurement methods

    Science.gov (United States)

    Niedermann, Reto; Wyss, Eva; Annaheim, Simon; Psikuta, Agnes; Davey, Sarah; Rossi, René Michel

    2014-01-01

    The measurement of core body temperature is an efficient method for monitoring heat stress amongst workers in hot conditions. However, invasive measurement of core body temperature (e.g. rectal, intestinal, oesophageal temperature) is impractical for such applications. Therefore, the aim of this study was to define relevant non-invasive measures to predict core body temperature under various conditions. We conducted two human subject studies with different experimental protocols, different environmental temperatures (10 °C, 30 °C) and different subjects. In both studies the same non-invasive measurement methods (skin temperature, skin heat flux, heart rate) were applied. A principle component analysis was conducted to extract independent factors, which were then used in a linear regression model. We identified six parameters (three skin temperatures, two skin heat fluxes and heart rate), which were included for the calculation of two factors. The predictive value of these factors for core body temperature was evaluated by a multiple regression analysis. The calculated root mean square deviation (rmsd) was in the range from 0.28 °C to 0.34 °C for all environmental conditions. These errors are similar to previous models using non-invasive measures to predict core body temperature. The results from this study illustrate that multiple physiological parameters (e.g. skin temperature and skin heat fluxes) are needed to predict core body temperature. In addition, the physiological measurements chosen in this study and the algorithm defined in this work are potentially applicable as real-time core body temperature monitoring to assess health risk in broad range of working conditions.

  17. Prediction of human core body temperature using non-invasive measurement methods.

    Science.gov (United States)

    Niedermann, Reto; Wyss, Eva; Annaheim, Simon; Psikuta, Agnes; Davey, Sarah; Rossi, René Michel

    2014-01-01

    The measurement of core body temperature is an efficient method for monitoring heat stress amongst workers in hot conditions. However, invasive measurement of core body temperature (e.g. rectal, intestinal, oesophageal temperature) is impractical for such applications. Therefore, the aim of this study was to define relevant non-invasive measures to predict core body temperature under various conditions. We conducted two human subject studies with different experimental protocols, different environmental temperatures (10 °C, 30 °C) and different subjects. In both studies the same non-invasive measurement methods (skin temperature, skin heat flux, heart rate) were applied. A principle component analysis was conducted to extract independent factors, which were then used in a linear regression model. We identified six parameters (three skin temperatures, two skin heat fluxes and heart rate), which were included for the calculation of two factors. The predictive value of these factors for core body temperature was evaluated by a multiple regression analysis. The calculated root mean square deviation (rmsd) was in the range from 0.28 °C to 0.34 °C for all environmental conditions. These errors are similar to previous models using non-invasive measures to predict core body temperature. The results from this study illustrate that multiple physiological parameters (e.g. skin temperature and skin heat fluxes) are needed to predict core body temperature. In addition, the physiological measurements chosen in this study and the algorithm defined in this work are potentially applicable as real-time core body temperature monitoring to assess health risk in broad range of working conditions.

  18. P2X(3) receptor gating near normal body temperature

    Czech Academy of Sciences Publication Activity Database

    Kmyhz, V.; Maximyuk, O.; Teslenko, V.; Verkhratsky, Alexei; Krishtal, O.

    2008-01-01

    Roč. 456, č. 12 (2008), s. 339-347 ISSN 0031-6768 Institutional research plan: CEZ:AV0Z50390703 Keywords : P2X3 receptors * Temperature-sensitivity * Gating Subject RIV: FH - Neurology Impact factor: 3.526, year: 2008

  19. Monitoring the body temperature of cows and calves using video recordings from an infrared thermography camera.

    Science.gov (United States)

    Hoffmann, Gundula; Schmidt, Mariana; Ammon, Christian; Rose-Meierhöfer, Sandra; Burfeind, Onno; Heuwieser, Wolfgang; Berg, Werner

    2013-06-01

    The aim of this study was to assess the variability of temperatures measured by a video-based infrared camera (IRC) in comparison to rectal and vaginal temperatures. The body surface temperatures of cows and calves were measured contactless at different body regions using videos from the IRC. Altogether, 22 cows and 9 calves were examined. The differences of the measured IRC temperatures among the body regions, i.e. eye (mean: 37.0 °C), back of the ear (35.6 °C), shoulder (34.9 °C) and vulva (37.2 °C), were significant (P infrared thermography videos has the advantage to analyze more than 1 picture per animal in a short period of time, and shows potential as a monitoring system for body temperatures in cattle.

  20. A study on the applicability of implantable microchip transponders for body temperature measurements in pigs

    DEFF Research Database (Denmark)

    Lohse, Louise; Uttenthal, Åse; Enøe, Claes

    2010-01-01

    Background The applicability of an electronic monitoring system using microchip transponders for measurement of body temperatures was tested in 6-week-old conventional Danish weaners infected with classical swine fever virus (CSFV). Subcutaneous tissue temperatures obtained by the implantable...... transponders were compared with rectal temperatures, recorded by a conventional digital thermometer. Methods In a preliminary study, transponders were inserted subcutaneously at 6 different positions of the body of 5 pigs. The transponders positioned by the ear base provided the best correlation to rectal......C lower than the rectal temperature. However, a simple linear relationship between the measures of the two methods was found. Conclusions Our study showed that the tested body monitoring system may represent a promising tool to obtain an approximate correlate of body temperatures in groups of pigs...

  1. Increased benefit of alteplase in patients with ischemic stroke and a high body temperature.

    Science.gov (United States)

    de Ridder, Inger; den Hertog, Heleen; van Gemert, Maarten; Dippel, Diederik; van der Worp, Bart

    2013-01-01

    In observational studies, a high body temperature has been associated with unfavorable outcome. In in vitro studies, the fibrinolytic activity of alteplase decreased 5% per degree Celsius reduction in temperature. The modifying effect of body temperature on treatment with alteplase in patients with acute ischemic stroke is unclear. We assessed the influence of baseline body temperature on the effect of alteplase on functional outcome in patients with acute ischemic stroke, included in the Paracetamol (Acetaminophen) in Stroke (PAIS) trial. PAIS was a randomized, double-blind clinical trial to assess the effect of high-dose paracetamol on functional outcome in patients with acute stroke. For this study, we selected all patients with ischemic stroke and randomization within 6 h of symptom onset. We estimated the effect of treatment with alteplase on the modified Rankin Scale score at 3 months with ordinal logistic regression, stratified by baseline body temperature. We made adjustments for confounding factors and expressed associations as adjusted odds ratios (aOR) with 95% confidence intervals (CI). We also tested for interaction between treatment with alteplase and body temperature. We included 647 of the 1,400 patients in PAIS in our study. Treatment with alteplase was associated with improved functional outcome at 3 months (aOR 1.51, 95% CI 1.09-2.08). In the 286 patients (44%) with a baseline body temperature of 37.0°C or higher, alteplase was associated with a larger effect (aOR 2.13, 95% CI 1.28-3.45) than in patients with a temperature below 37.0°C (aOR 1.11, 95% CI 0.71-1.69). A test for interaction between body temperature and alteplase did not reach statistical significance (p = 0.18). Patients with ischemic stroke and a high body temperature may have a larger benefit of treatment with alteplase than patients with lower body temperatures. These findings are in line with those from in vitro studies, in which lowering temperature decreased the fibrinolytic

  2. Body temperature and major neurological improvement in tPA-treated stroke patients.

    Science.gov (United States)

    Kvistad, C E; Thomassen, L; Waje-Andreassen, U; Logallo, N; Naess, H

    2014-05-01

    Major neurological improvement (MNI) at 24 hours represents a marker of early recanalization in ischaemic stroke. Although low body temperature is considered neuroprotective in cerebral ischaemia, some studies have suggested that higher body temperature may promote clot lysis in the acute phase of ischaemic stroke. We hypothesized that higher body temperature was associated with MNI in severe stroke patients treated with tPA, suggesting a beneficial effect of higher body temperature on clot lysis and recanalization. Patients with ischaemic stroke or transient ischaemic attack (TIA) treated with tPA between February 2006 and August 2012 were prospectively included and retrospectively analysed. Body temperature was measured upon admission. MNI was defined by a ≥8 point improvement in NIHSS score at 24 hours as compared to NIHSS score on admission. No significant improvement (no-MNI) was defined by either an increase in NIHSS score or a decrease of ≤2 points at 24 hours in patients with an admission NIHSS score of ≥8. Of the 2351 patients admitted with ischaemic stroke or TIA, 347 patients (14.8%) were treated with tPA. A total of 32 patients (9.2%) had MNI and 56 patients (16.1%) had no-MNI. Patients with MNI had higher body temperatures compared with patients with no-MNI (36.7°C vs 36.3°C, P = 0.004). Higher body temperature was independently associated with MNI when adjusted for confounders (OR 5.16, P = 0.003). Higher body temperature was independently associated with MNI in severe ischaemic stroke patients treated with tPA. This may suggest a beneficial effect of higher body temperature on clot lysis and recanalization. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Plasticity of Performance Curves Can Buffer Reaction Rates from Body Temperature Variation in Active Endotherms

    Directory of Open Access Journals (Sweden)

    Frank Seebacher

    2017-08-01

    Full Text Available Endotherms regulate their core body temperature by adjusting metabolic heat production and insulation. Endothermic body temperatures are therefore relatively stable compared to external temperatures. The thermal sensitivity of biochemical reaction rates is thought to have co-evolved with body temperature regulation so that optimal reaction rates occur at the regulated body temperature. However, recent data show that core body temperatures even of non-torpid endotherms fluctuate considerably. Additionally, peripheral temperatures can be considerably lower and more variable than core body temperatures. Here we discuss whether published data support the hypothesis that thermal performance curves of physiological reaction rates are plastic so that performance is maintained despite variable body temperatures within active (non-torpid endotherms, and we explore mechanisms that confer plasticity. There is evidence that thermal performance curves in tissues that experience thermal fluctuations can be plastic, although this question remains relatively unexplored for endotherms. Mechanisms that alter thermal responses locally at the tissue level include transient potential receptor ion channels (TRPV and TRPM and the AMP-activated protein kinase (AMPK both of which can influence metabolism and energy expenditure. Additionally, the thermal sensitivity of processes that cause post-transcriptional RNA degradation can promote the relative expression of cold-responsive genes. Endotherms can respond to environmental fluctuations similarly to ectotherms, and thermal plasticity complements core body temperature regulation to increase whole-organism performance. Thermal plasticity is ancestral to endothermic thermoregulation, but it has not lost its selective advantage so that modern endotherms are a physiological composite of ancestral ectothermic and derived endothermic traits.

  4. Plasticity of Performance Curves Can Buffer Reaction Rates from Body Temperature Variation in Active Endotherms

    Science.gov (United States)

    Seebacher, Frank; Little, Alexander G.

    2017-01-01

    Endotherms regulate their core body temperature by adjusting metabolic heat production and insulation. Endothermic body temperatures are therefore relatively stable compared to external temperatures. The thermal sensitivity of biochemical reaction rates is thought to have co-evolved with body temperature regulation so that optimal reaction rates occur at the regulated body temperature. However, recent data show that core body temperatures even of non-torpid endotherms fluctuate considerably. Additionally, peripheral temperatures can be considerably lower and more variable than core body temperatures. Here we discuss whether published data support the hypothesis that thermal performance curves of physiological reaction rates are plastic so that performance is maintained despite variable body temperatures within active (non-torpid) endotherms, and we explore mechanisms that confer plasticity. There is evidence that thermal performance curves in tissues that experience thermal fluctuations can be plastic, although this question remains relatively unexplored for endotherms. Mechanisms that alter thermal responses locally at the tissue level include transient potential receptor ion channels (TRPV and TRPM) and the AMP-activated protein kinase (AMPK) both of which can influence metabolism and energy expenditure. Additionally, the thermal sensitivity of processes that cause post-transcriptional RNA degradation can promote the relative expression of cold-responsive genes. Endotherms can respond to environmental fluctuations similarly to ectotherms, and thermal plasticity complements core body temperature regulation to increase whole-organism performance. Thermal plasticity is ancestral to endothermic thermoregulation, but it has not lost its selective advantage so that modern endotherms are a physiological composite of ancestral ectothermic and derived endothermic traits. PMID:28824463

  5. Plasticity of Performance Curves Can Buffer Reaction Rates from Body Temperature Variation in Active Endotherms.

    Science.gov (United States)

    Seebacher, Frank; Little, Alexander G

    2017-01-01

    Endotherms regulate their core body temperature by adjusting metabolic heat production and insulation. Endothermic body temperatures are therefore relatively stable compared to external temperatures. The thermal sensitivity of biochemical reaction rates is thought to have co-evolved with body temperature regulation so that optimal reaction rates occur at the regulated body temperature. However, recent data show that core body temperatures even of non-torpid endotherms fluctuate considerably. Additionally, peripheral temperatures can be considerably lower and more variable than core body temperatures. Here we discuss whether published data support the hypothesis that thermal performance curves of physiological reaction rates are plastic so that performance is maintained despite variable body temperatures within active (non-torpid) endotherms, and we explore mechanisms that confer plasticity. There is evidence that thermal performance curves in tissues that experience thermal fluctuations can be plastic, although this question remains relatively unexplored for endotherms. Mechanisms that alter thermal responses locally at the tissue level include transient potential receptor ion channels (TRPV and TRPM) and the AMP-activated protein kinase (AMPK) both of which can influence metabolism and energy expenditure. Additionally, the thermal sensitivity of processes that cause post-transcriptional RNA degradation can promote the relative expression of cold-responsive genes. Endotherms can respond to environmental fluctuations similarly to ectotherms, and thermal plasticity complements core body temperature regulation to increase whole-organism performance. Thermal plasticity is ancestral to endothermic thermoregulation, but it has not lost its selective advantage so that modern endotherms are a physiological composite of ancestral ectothermic and derived endothermic traits.

  6. Microchip transponder thermometry for monitoring core body temperature of antelope during capture.

    Science.gov (United States)

    Rey, Benjamin; Fuller, Andrea; Hetem, Robyn S; Lease, Hilary M; Mitchell, Duncan; Meyer, Leith C R

    2016-01-01

    Hyperthermia is described as the major cause of morbidity and mortality associated with capture, immobilization and restraint of wild animals. Therefore, accurately determining the core body temperature of wild animals during capture is crucial for monitoring hyperthermia and the efficacy of cooling procedures. We investigated if microchip thermometry can accurately reflect core body temperature changes during capture and cooling interventions in the springbok (Antidorcas marsupialis), a medium-sized antelope. Subcutaneous temperature measured with a temperature-sensitive microchip was a weak predictor of core body temperature measured by temperature-sensitive data loggers in the abdominal cavity (R(2)=0.32, bias >2 °C). Temperature-sensitive microchips in the gluteus muscle, however, provided an accurate estimate of core body temperature (R(2)=0.76, bias=0.012 °C). Microchips inserted into muscle therefore provide a convenient and accurate method to measure body temperature continuously in captured antelope, allowing detection of hyperthermia and the efficacy of cooling procedures. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Data logging of body temperatures provides precise information on phenology of reproductive events in a free-living arctic hibernator

    Science.gov (United States)

    Williams, C.T.; Sheriff, M.J.; Schmutz, J.A.; Kohl, F.; Toien, O.; Buck, C.L.; Barnes, B.M.

    2011-01-01

    Precise measures of phenology are critical to understanding how animals organize their annual cycles and how individuals and populations respond to climate-induced changes in physical and ecological stressors. We show that patterns of core body temperature (T b) can be used to precisely determine the timing of key seasonal events including hibernation, mating and parturition, and immergence and emergence from the hibernacula in free-living arctic ground squirrels (Urocitellus parryii). Using temperature loggers that recorded T b every 20 min for up to 18 months, we monitored core T b from three females that subsequently gave birth in captivity and from 66 female and 57 male ground squirrels free-living in the northern foothills of the Brooks Range Alaska. In addition, dates of emergence from hibernation were visually confirmed for four free-living male squirrels. Average T b in captive females decreased by 0.5–1.0°C during gestation and abruptly increased by 1–1.5°C on the day of parturition. In free-living females, similar shifts in T b were observed in 78% (n = 9) of yearlings and 94% (n = 31) of adults; females without the shift are assumed not to have given birth. Three of four ground squirrels for which dates of emergence from hibernation were visually confirmed did not exhibit obvious diurnal rhythms in T b until they first emerged onto the surface when T b patterns became diurnal. In free-living males undergoing reproductive maturation, this pre-emergence euthermic interval averaged 20.4 days (n = 56). T b-loggers represent a cost-effective and logistically feasible method to precisely investigate the phenology of reproduction and hibernation in ground squirrels.

  8. Deeply torpid bats can change position without elevation of body temperature.

    Science.gov (United States)

    Bartonička, Tomáš; Bandouchova, Hana; Berková, Hana; Blažek, Ján; Lučan, Radek; Horáček, Ivan; Martínková, Natália; Pikula, Jiri; Řehák, Zdeněk; Zukal, Jan

    2017-01-01

    Because body temperature is tightly coupled to physiological function, hibernating animals entering deep torpor are typically immobile. We analysed thermal behaviour and locomotory activity of hibernating greater mouse-eared bats Myotis myotis and found two types of movement behaviour related to body temperature, i.e. movement at high fur temperature and at low fur temperatures (Tflow; body temperature. Distance travelled, flight duration and speed of locomotion during Tflow events was lower than in high fur temperature events. Such behaviour could allow bats to save energy long-term and prolong torpor bouts. Tflow movement in torpid bats significantly changes our understanding of basic hibernation principles and we strongly recommend further studies on the subject. Copyright © 2016. Published by Elsevier Ltd.

  9. Profound and rapid reduction in body temperature induced by the melanocortin receptor agonists.

    Science.gov (United States)

    Xu, Yuanzhong; Kim, Eun Ran; Fan, Shengjie; Xia, Yan; Xu, Yong; Huang, Cheng; Tong, Qingchun

    2014-08-22

    The melanocortin receptor 4 (MC4R) plays a major role in body weight regulation and its agonist MTII has been widely used to study the role of MC4Rs in energy expenditure promotion and feeding reduction. Unexpectedly, we observed that intraperitoneal (i.p.) administration of MTII induced a rapid reduction in both body temperature and energy expenditure, which was independent of its effect on feeding and followed by a prolonged increase in energy expenditure. The rapid reduction was at least partly mediated by brain neurons since intracerebroventricular (icv) administration of alpha melanocyte-stimulating hormone, an endogenous melanocortin receptor agonist, produced a similar response. In addition, the body temperature-lowering effect of MTII was independent of the presence of MC4Rs, but in a similar fashion to the previously shown effect on body temperature by 5'AMP. Moreover, β-adrenergic receptors (β-ARs) were required for the recovery from low body temperature induced by MTII and further pharmacological studies showed that the MTII's effect on body temperature may be partially mediated by the vasopressin V1a receptors. Collectively, our results reveal a previously unappreciated role for the melanocortin pathway in rapidly lowering body temperature. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Temporal profile of body temperature in acute ischemic stroke: relation to infarct size and outcome.

    Science.gov (United States)

    Geurts, Marjolein; Scheijmans, Féline E V; van Seeters, Tom; Biessels, Geert J; Kappelle, L Jaap; Velthuis, Birgitta K; van der Worp, H Bart

    2016-11-21

    High body temperatures after ischemic stroke have been associated with larger infarct size, but the temporal profile of this relation is unknown. We assess the relation between temporal profile of body temperature and infarct size and functional outcome in patients with acute ischemic stroke. In 419 patients with acute ischemic stroke we assessed the relation between body temperature on admission and during the first 3 days with both infarct size and functional outcome. Infarct size was measured in milliliters on CT or MRI after 3 days. Poor functional outcome was defined as a modified Rankin Scale score ≥3 at 3 months. Body temperature on admission was not associated with infarct size or poor outcome in adjusted analyses. By contrast, each additional 1.0 °C in body temperature on day 1 was associated with 0.31 ml larger infarct size (95% confidence interval (CI) 0.04-0.59), on day 2 with 1.13 ml larger infarct size(95% CI, 0.83-1.43), and on day 3 with 0.80 ml larger infarct size (95% CI, 0.48-1.12), in adjusted linear regression analyses. Higher peak body temperatures on days two and three were also associated with poor outcome (adjusted relative risks per additional 1.0 °C in body temperature, 1.52 (95% CI, 1.17-1.99) and 1.47 (95% CI, 1.22-1.77), respectively). Higher peak body temperatures during the first days after ischemic stroke, rather than on admission, are associated with larger infarct size and poor functional outcome. This suggests that prevention of high temperatures may improve outcome if continued for at least 3 days.

  11. Changes in body core temperatures and heat balance after an abrupt release of lower body negative pressure in humans

    Science.gov (United States)

    Tanabe, Minoru; Shido, Osamu

    1994-03-01

    Changes in body core temperature ( T cor) and heat balance after an abrupt release of lower body negative pressure (LBNP) were investigated in 5 volunteers under the following conditions: (1) an ambient temperature ( T a) of 20 °C or (2) 35 °C, and (3) T a of 25 °C with a leg skin temperature of 30°C or (4) 35°C. The leg skin temperature was controlled with water perfusion devices wound around the legs. Rectal ( T re), tympanic ( T ty) and esophageal ( T es) temperatures, skin temperatures (7 sites) and oxygen consumption were measured. The intensity of LBNP was adjusted so that the amount of blood pooled in the legs was the same under all conditions. When a thermal balance was attained during LBNP, application of LBNP was suddenly halted. The skin temperatures increased significantly after the release of LBNP under all conditions, while oxygen consumption hardly changed. The release of LBNP caused significant falls in T cor s under conditions (1) and (3), but lowered T cor s very slightly under conditions (2) and (4). The changes in T es were always more rapid and greater than those of T ty and T re. The falls in T ty and T re appeared to be explained by changes in heat balance, whereas the sharp drop of T es could not be explained especially during the first 8 min after the release of LBNP. The results suggest that a fall in T cor after a release of LBNP is attributed to an increase in heat loss due to reflexive skin vasodilation and is dependent on the temperature of venous blood returning from the lower body. It is presumed that T es may not be an appropriate indicator for T cor when venous return changes rapidly.

  12. Relationships between brain and body temperature, clinical and imaging outcomes after ischemic stroke

    Science.gov (United States)

    Karaszewski, Bartosz; Carpenter, Trevor K; Thomas, Ralph G R; Armitage, Paul A; Lymer, Georgina Katherine S; Marshall, Ian; Dennis, Martin S; Wardlaw, Joanna M

    2013-01-01

    Pyrexia soon after stroke is associated with severe stroke and poor functional outcome. Few studies have assessed brain temperature after stroke in patients, so little is known of its associations with body temperature, stroke severity, or outcome. We measured temperatures in ischemic and normal-appearing brain using 1H-magnetic resonance spectroscopy and its correlations with body (tympanic) temperature measured four-hourly, infarct growth by 5 days, early neurologic (National Institute of Health Stroke Scale, NIHSS) and late functional outcome (death or dependency). Among 40 patients (mean age 73 years, median NIHSS 7, imaged at median 17 hours), temperature in ischemic brain was higher than in normal-appearing brain on admission (38.6°C-core, 37.9°C-contralateral hemisphere, P=0.03) but both were equally elevated by 5 days; both were higher than tympanic temperature. Ischemic lesion temperature was not associated with NIHSS or 3-month functional outcome; in contrast, higher contralateral normal-appearing brain temperature was associated with worse NIHSS, infarct expansion and poor functional outcome, similar to associations for tympanic temperature. We conclude that brain temperature is higher than body temperature; that elevated temperature in ischemic brain reflects a local tissue response to ischemia, whereas pyrexia reflects the systemic response to stroke, occurs later, and is associated with adverse outcomes. PMID:23571281

  13. Using Three-Body Recombination to Extract Electron Temperatures of Ultracold Plasmas

    International Nuclear Information System (INIS)

    Fletcher, R. S.; Zhang, X. L.; Rolston, S. L.

    2007-01-01

    Three-body recombination, an important collisional process in plasmas, increases dramatically at low electron temperatures, with an accepted scaling of T e -9/2 . We measure three-body recombination in an ultracold neutral xenon plasma by detecting recombination-created Rydberg atoms using a microwave-ionization technique. With the accepted theory (expected to be applicable for weakly coupled plasmas) and our measured rates, we extract the plasma temperatures, which are in reasonable agreement with previous measurements early in the plasma lifetime. The resulting electron temperatures indicate that the plasma continues to cool to temperatures below 1 K

  14. Intraoperative body temperature control: esophageal thermometer versus infrared tympanic thermometer.

    Science.gov (United States)

    Poveda, Vanessa de Brito; Nascimento, Ariane de Souza

    2016-01-01

    To verify the correlation between temperature measurements performed using an infrared tympanic thermometer and an esophageal thermometer during the intraoperative period. A longitudinal study of repeated measures was performed including subjects aged 18 years or older undergoing elective oncologic surgery of the digestive system, with anesthesia duration of at least 1 hour. Temperature measurements were performed simultaneously by a calibrated esophageal thermometer and by a calibrated infrared tympanic thermometer, with laboratory reading precision of ±0.2ºC. The operating room temperature remained between 19 and 21ºC. The study included 51 patients, mostly men (51%), white (80.4%). All patients were kept warm by a forced-air heating system, for an average of 264.14 minutes (SD = 87.7). The two temperature measurements showed no different behavior over time (p = 0.2205), however, tympanic measurements were consistently 1.24°C lower (pde temperatura realizadas por meio de um termômetro timpânico por infravermelho e por um termômetro esofágico, durante o período intraoperatório. Realizou-se um estudo longitudinal, de medidas repetidas, incluindo sujeitos com idade igual ou superior a 18 anos, submetidos à cirurgia oncológica eletiva do sistema digestório, com duração da anestesia de, no mínimo, 1 hora. As medidas de temperatura eram realizadas, ao mesmo tempo, por meio de um termômetro esofágico calibrado e por termômetro timpânico por infravermelho calibrado, com precisão de leitura em laboratório de ±0,2ºC. A temperatura da sala operatória permaneceu entre 19 e 21ºC. Foram incluídos 51 pacientes, em sua maioria homens (51%), brancos (80,4%). Todos os pacientes foram aquecidos com o sistema de ar forçado aquecido, em média por 264,14 minutos (DP = 87,7). As duas medidas de temperatura não tiveram comportamento diferente ao longo do tempo (p = 0,2205), mas a medida timpânica foi consistentemente menor em 1,24°C (p < 0,0001). O term

  15. Emperor penguin body surfaces cool below air temperature.

    Science.gov (United States)

    McCafferty, D J; Gilbert, C; Thierry, A-M; Currie, J; Le Maho, Y; Ancel, A

    2013-06-23

    Emperor penguins Aptenodytes forsteri are able to survive the harsh Antarctic climate because of specialized anatomical, physiological and behavioural adaptations for minimizing heat loss. Heat transfer theory predicts that metabolic heat loss in this species will mostly depend on radiative and convective cooling. To examine this, thermal imaging of emperor penguins was undertaken at the breeding colony of Pointe Géologie in Terre Adélie (66°40' S 140° 01' E), Antarctica in June 2008. During clear sky conditions, most outer surfaces of the body were colder than surrounding sub-zero air owing to radiative cooling. In these conditions, the feather surface will paradoxically gain heat by convection from surrounding air. However, owing to the low thermal conductivity of plumage any heat transfer to the skin surface will be negligible. Future thermal imaging studies are likely to yield further insights into the adaptations of this species to the Antarctic climate.

  16. Hibernation in black bears: independence of metabolic suppression from body temperature.

    Science.gov (United States)

    Tøien, Øivind; Blake, John; Edgar, Dale M; Grahn, Dennis A; Heller, H Craig; Barnes, Brian M

    2011-02-18

    Black bears hibernate for 5 to 7 months a year and, during this time, do not eat, drink, urinate, or defecate. We measured metabolic rate and body temperature in hibernating black bears and found that they suppress metabolism to 25% of basal rates while regulating body temperature from 30° to 36°C, in multiday cycles. Heart rates were reduced from 55 to as few as 9 beats per minute, with profound sinus arrhythmia. After returning to normal body temperature and emerging from dens, bears maintained a reduced metabolic rate for up to 3 weeks. The pronounced reduction and delayed recovery of metabolic rate in hibernating bears suggest that the majority of metabolic suppression during hibernation is independent of lowered body temperature.

  17. Wearable sensors in intelligent clothing for measuring human body temperature based on optical fiber Bragg grating.

    Science.gov (United States)

    Li, Hongqiang; Yang, Haijing; Li, Enbang; Liu, Zhihui; Wei, Kejia

    2012-05-21

    Measuring body temperature is considerably important to physiological studies as well as clinical investigations. In recent years, numerous observations have been reported and various methods of measurement have been employed. The present paper introduces a novel wearable sensor in intelligent clothing for human body temperature measurement. The objective is the integration of optical fiber Bragg grating (FBG)-based sensors into functional textiles to extend the capabilities of wearable solutions for body temperature monitoring. In addition, the temperature sensitivity is 150 pm/°C, which is almost 15 times higher than that of a bare FBG. This study combines large and small pipes during fabrication to implant FBG sensors into the fabric. The law of energy conservation of the human body is considered in determining heat transfer between the body and its clothing. The mathematical model of heat transmission between the body and clothed FBG sensors is studied, and the steady-state thermal analysis is presented. The simulation results show the capability of the material to correct the actual body temperature. Based on the skin temperature obtained by the weighted average method, this paper presents the five points weighted coefficients model using both sides of the chest, armpits, and the upper back for the intelligent clothing. The weighted coefficients of 0.0826 for the left chest, 0.3706 for the left armpit, 0.3706 for the right armpit, 0.0936 for the upper back, and 0.0826 for the right chest were obtained using Cramer's Rule. Using the weighting coefficient, the deviation of the experimental result was ± 0.18 °C, which favors the use for clinical armpit temperature monitoring. Moreover, in special cases when several FBG sensors are broken, the weighted coefficients of the other sensors could be changed to obtain accurate body temperature.

  18. Resetting of circadian melatonin and cortisol rhythms in humans by ordinary room light

    Science.gov (United States)

    Boivin, D. B.; Czeisler, C. A.

    1998-01-01

    The present study was designed to investigate whether a weak photic stimulus can reset the endogenous circadian rhythms of plasma melatonin and plasma cortisol in human subjects. A stimulus consisting of three cycles of 5 h exposures to ordinary room light (approximately 180 lux), centered 1.5 h after the endogenous temperature nadir, significantly phase-advanced the plasma melatonin rhythm in eight healthy young men compared with the phase delays observed in eight control subjects who underwent the same protocol but were exposed to darkness (p melatonin and plasma cortisol maintained stable temporal relationships with the endogenous core body temperature cycle, consistent with the conclusion that exposure to ordinary indoor room light had shifted a master circadian pacemaker.

  19. Continuous exposure to a novel stressor based on water aversion induces abnormal circadian locomotor rhythms and sleep-wake cycles in mice.

    Science.gov (United States)

    Miyazaki, Koyomi; Itoh, Nanako; Ohyama, Sumika; Kadota, Koji; Oishi, Katsutaka

    2013-01-01

    Psychological stressors prominently affect diurnal rhythms, including locomotor activity, sleep, blood pressure, and body temperature, in humans. Here, we found that a novel continuous stress imposed by the perpetual avoidance of water on a wheel (PAWW) affected several physiological diurnal rhythms in mice. One week of PAWW stress decayed robust circadian locomotor rhythmicity, while locomotor activity was evident even during the light period when the mice are normally asleep. Daytime activity was significantly upregulated, whereas nighttime activity was downregulated, resulting in a low amplitude of activity. Total daily activity gradually decreased with increasing exposure to PAWW stress. The mice could be exposed to PAWW stress for over 3 weeks without adaptation. Furthermore, continuous PAWW stress enhanced food intake, but decreased body weight and plasma leptin levels, indicating that sleep loss and PAWW stress altered the energy balance in these mice. The diurnal rhythm of corticosterone levels was not severely affected. The body temperature rhythm was diurnal in the stressed mice, but significantly dysregulated during the dark period. Plasma catecholamines were elevated in the stressed mice. Continuous PAWW stress reduced the duration of daytime sleep, especially during the first half of the light period, and increased nighttime sleepiness. Continuous PAWW stress also simultaneously obscured sleep/wake and locomotor activity rhythms compared with control mice. These sleep architecture phenotypes under stress are similar to those of patients with insomnia. The stressed mice could be entrained to the light/dark cycle, and when they were transferred to constant darkness, they exhibited a free-running circadian rhythm with a timing of activity onset predicted by the phase of their entrained rhythms. Circadian gene expression in the liver and muscle was unaltered, indicating that the peripheral clocks in these tissues remained intact.

  20. Continuous exposure to a novel stressor based on water aversion induces abnormal circadian locomotor rhythms and sleep-wake cycles in mice.

    Directory of Open Access Journals (Sweden)

    Koyomi Miyazaki

    Full Text Available Psychological stressors prominently affect diurnal rhythms, including locomotor activity, sleep, blood pressure, and body temperature, in humans. Here, we found that a novel continuous stress imposed by the perpetual avoidance of water on a wheel (PAWW affected several physiological diurnal rhythms in mice. One week of PAWW stress decayed robust circadian locomotor rhythmicity, while locomotor activity was evident even during the light period when the mice are normally asleep. Daytime activity was significantly upregulated, whereas nighttime activity was downregulated, resulting in a low amplitude of activity. Total daily activity gradually decreased with increasing exposure to PAWW stress. The mice could be exposed to PAWW stress for over 3 weeks without adaptation. Furthermore, continuous PAWW stress enhanced food intake, but decreased body weight and plasma leptin levels, indicating that sleep loss and PAWW stress altered the energy balance in these mice. The diurnal rhythm of corticosterone levels was not severely affected. The body temperature rhythm was diurnal in the stressed mice, but significantly dysregulated during the dark period. Plasma catecholamines were elevated in the stressed mice. Continuous PAWW stress reduced the duration of daytime sleep, especially during the first half of the light period, and increased nighttime sleepiness. Continuous PAWW stress also simultaneously obscured sleep/wake and locomotor activity rhythms compared with control mice. These sleep architecture phenotypes under stress are similar to those of patients with insomnia. The stressed mice could be entrained to the light/dark cycle, and when they were transferred to constant darkness, they exhibited a free-running circadian rhythm with a timing of activity onset predicted by the phase of their entrained rhythms. Circadian gene expression in the liver and muscle was unaltered, indicating that the peripheral clocks in these tissues remained intact.

  1. Use of extremity insulation during whole body hyperthermia to reduce temperature nonuniformity

    International Nuclear Information System (INIS)

    Thrall, D.E.; Page, R.L.

    1987-01-01

    The author previously documented during whole body hyperthermia in dogs using a radiant heating device that temperature at superficial sites, including tibial bone marrow, falls below systemic arterial temperature during the plateau phase of heating. This may be due to direct heat loss to the environment. Sites where temperature is lower than systemic arterial temperature during the plateau phase may become sanctuary sites where tumor deposits are spared because they do not receive the prescribed thermal dose. In an attempt to decrease temperature nonuniformity and increase thermal dose delivered to such superficial sites, extremity insulation has been employed during whole body hyperthermia in dogs. The author measured temperature at cutaneous and subcutaneous sites and within tibial bone marrow in insulated and noninsulated extremities of dogs undergoing whole body hyperthermia in the radiant heating device. The author found that extremity insulation is effective in reducing extremity temperature nonuniformity. Specific results are presented. Extremity insulation may be necessary during whole body hyperthermia to assure that extremity tumor deposits receive a thermal dose similar to that prescribed for the entire body

  2. Changes in body temperature and water intake following intracerebral implantation of carbachol in rats

    NARCIS (Netherlands)

    Hulst, S.G.T.; Wied, D. de

    1967-01-01

    Intracerebral carbachol produced a fall in core temperature in the rat when implanted in the area preoptica, the nucleus lateralis septi and the area between the thalamic nuclei and the nucleus ruber. Cholinergic stimulation of the anterohypothalamic region did not affect body temperature, while

  3. Variations of body temperature and metabolism during entrance into cold lethargy in the bat Myotis myotis

    NARCIS (Netherlands)

    Heldmaier, Gerhard

    1970-01-01

    Bats of temperate zones which hibernate during winter become cold-lethargic during their diurnal rest time even in summer. At the end of their nocturnal activity period they show a drop in body temperature close to ambient temperature (M. myotis, cf. Pohl, 1961). This takes place periodically even

  4. No effects of huddling on core body temperature in rock hyrax ...

    African Journals Online (AJOL)

    Huddling is a behavioural energy conservation mechanism that is widely used by many small endotherms at low ambient temperatures. Huddling has many benefits, including decreasing the metabolic cost of maintaining body temperature (Tb), reducing the amount of heat lost to the environment, and increasing the local ...

  5. Improvements in X-band transmitter phase stability through Klystron body temperature regulation

    Science.gov (United States)

    Perez, R. M.

    1992-01-01

    This article describes the techniques used and experimental results obtained in improving transmitter stability by control of the klystron body temperature. Related work in the measurement of klystron phase control parameters (pushing factors) is also discussed. The contribution of wave guide temperature excursions to uplink phase stability is presented. Suggestions are made as to the direction of future work in this area.

  6. Dedicated tool to assess the impact of a rhetorical task on human body temperature.

    Science.gov (United States)

    Koprowski, Robert; Wilczyński, Sławomir; Martowska, Katarzyna; Gołuch, Dominik; Wrocławska-Warchala, Emilia

    2017-10-01

    Functional infrared thermal imaging is a method widely used in medicine, including analysis of the mechanisms related to the effect of emotions on physiological processes. The article shows how the body temperature may change during stress associated with performing a rhetorical task and proposes new parameters useful for dynamic thermal imaging measurements MATERIALS AND METHODS: 29 healthy male subjects were examined. They were given a rhetorical task that induced stress. Analysis and processing of collected body temperature data in a spatial resolution of 256×512pixels and a temperature resolution of 0.1°C enabled to show the dynamics of temperature changes. This analysis was preceded by dedicated image analysis and processing methods RESULTS: The presented dedicated algorithm for image analysis and processing allows for fully automated, reproducible and quantitative assessment of temperature changes and time constants in a sequence of thermal images of the patient. When performing the rhetorical task, the temperature rose by 0.47±0.19°C in 72.41% of the subjects, including 20.69% in whom the temperature decreased by 0.49±0.14°C after 237±141s. For 20.69% of the subjects only a drop in temperature was registered. For the remaining 6.89% of the cases, no temperature changes were registered CONCLUSIONS: The performance of the rhetorical task by the subjects causes body temperature changes. The ambiguous temperature response to the given stress factor indicates the complex mechanisms responsible for regulating stressful situations. Stress associated with the examination itself induces body temperature changes. These changes should always be taken into account in the analysis of infrared data. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Dynamics and complexity of body temperature in preterm infants nursed in incubators.

    Directory of Open Access Journals (Sweden)

    Kerstin Jost

    Full Text Available Poor control of body temperature is associated with mortality and major morbidity in preterm infants. We aimed to quantify its dynamics and complexity to evaluate whether indices from fluctuation analyses of temperature time series obtained within the first five days of life are associated with gestational age (GA and body size at birth, and presence and severity of typical comorbidities of preterm birth.We recorded 3h-time series of body temperature using a skin electrode in incubator-nursed preterm infants. We calculated mean and coefficient of variation of body temperature, scaling exponent alpha (Talpha derived from detrended fluctuation analysis, and sample entropy (TSampEn of temperature fluctuations. Data were analysed by multilevel multivariable linear regression.Data of satisfactory technical quality were obtained from 285/357 measurements (80% in 73/90 infants (81% with a mean (range GA of 30.1 (24.0-34.0 weeks. We found a positive association of Talpha with increasing levels of respiratory support after adjusting for GA and birth weight z-score (p<0.001; R2 = 0.38.Dynamics and complexity of body temperature in incubator-nursed preterm infants show considerable associations with GA and respiratory morbidity. Talpha may be a useful marker of autonomic maturity and severity of disease in preterm infants.

  8. Novel energy-saving strategies to multiple stressors in birds: the ultradian regulation of body temperature.

    Science.gov (United States)

    Tattersall, Glenn J; Roussel, Damien; Voituron, Yann; Teulier, Loïc

    2016-09-28

    This study aimed to examine thermoregulatory responses in birds facing two commonly experienced stressors, cold and fasting. Logging devices allowing long-term and precise access to internal body temperature were placed within the gizzards of ducklings acclimated to cold (CA) (5°C) or thermoneutrality (TN) (25°C). The animals were then examined under three equal 4-day periods: ad libitum feeding, fasting and re-feeding. Through the analysis of daily as well as short-term, or ultradian, variations of body temperature, we showed that while ducklings at TN show only a modest decline in daily thermoregulatory parameters when fasted, they exhibit reduced surface temperatures from key sites of vascular heat exchange during fasting. The CA birds, on the other hand, significantly reduced their short-term variations of body temperature while increasing long-term variability when fasting. This phenomenon would allow the CA birds to reduce the energetic cost of body temperature maintenance under fasting. By analysing ultradian regulation of body temperature, we describe a means by which an endotherm appears to lower thermoregulatory costs in response to the combined stressors of cold and fasting. © 2016 The Author(s).

  9. Body temperature changes induced by huddling in breeding male emperor penguins.

    Science.gov (United States)

    Gilbert, Caroline; Maho, Yvon Le; Perret, Martine; Ancel, André

    2007-01-01

    Huddling is the key energy-saving mechanism for emperor penguins to endure their 4-mo incubation fast during the Antarctic winter, but the underlying physiological mechanisms of this energy saving have remained elusive. The question is whether their deep body (core) temperature may drop in association with energy sparing, taking into account that successful egg incubation requires a temperature of about 36 degrees C and that ambient temperatures of up to 37.5 degrees C may be reached within tight huddles. Using data loggers implanted into five unrestrained breeding males, we present here the first data on body temperature changes throughout the breeding cycle of emperor penguins, with particular emphasis on huddling bouts. During the pairing period, core temperature decreased progressively from 37.5 +/- 0.4 degrees C to 36.5 +/- 0.3 degrees C, associated with a significant temperature drop of 0.5 +/- 0.3 degrees C during huddling. In case of egg loss, body temperature continued to decrease to 35.5 +/- 0.4 degrees C, with a further 0.9 degrees C decrease during huddling. By contrast, a constant core temperature of 36.9 +/- 0.2 degrees C was maintained during successful incubation, even during huddling, suggesting a trade-off between the demands for successful egg incubation and energy saving. However, such a limited drop in body temperature cannot explain the observed energy savings of breeding emperor penguins. Furthermore, we never observed any signs of hyperthermia in huddling birds that were exposed to ambient temperatures as high as above 35 degrees C. We suggest that the energy savings of huddling birds is due to a metabolic depression, the extent of which depends on a reduction of body surface areas exposed to cold.

  10. An intertidal sea star adjusts thermal inertia to avoid extreme body temperatures.

    Science.gov (United States)

    Pincebourde, Sylvain; Sanford, Eric; Helmuth, Brian

    2009-12-01

    The body temperature of ectotherms is influenced by the interaction of abiotic conditions, morphology, and behavior. Although organisms living in different thermal habitats may exhibit morphological plasticity or move from unfavorable locations, there are few examples of animals adjusting their thermal properties in response to short-term changes in local conditions. Here, we show that the intertidal sea star Pisaster ochraceus modulates its thermal inertia in response to prior thermal exposure. After exposure to high body temperature at low tide, sea stars increase the amount of colder-than-air fluid in their coelomic cavity when submerged during high tide, resulting in a lower body temperature during the subsequent low tide. Moreover, this buffering capacity is more effective when seawater is cold during the previous high tide. This ability to modify the volume of coelomic fluid provides sea stars with a novel thermoregulatory "backup" when faced with prolonged exposure to elevated aerial temperatures.

  11. Impacts of exhalation flow on the microenvironment around the human body under different room temperatures

    Science.gov (United States)

    Jafari, Mohammad Javad; Gharari, Noradin; Azari, Mansour Rezazade; Ashrafi, Khosro

    2018-04-01

    Exhalation flow and room temperature can have a considerable effect on the microenvironment in the vicinity of human body. In this study, impacts of exhalation flow and room temperature on the microenvironment around a human body were investigated using a numerical simulation. For this purpose, a computational fluid dynamic program was applied to study thermal plume around a sitting human body at different room temperatures of a calm indoor room by considering the exhalation flow. The simulation was supported by some experimental measurements. Six different room temperatures (18 to 28 °C) with two nose exhalation modes (exhalation and non-exhalation) were investigated. Overhead and breathing zone velocities and temperatures were simulated in different scenarios. This study finds out that the exhalation through the nose has a significant impact on both quantitative and qualitative features of the human microenvironment in different room temperatures. At a given temperature, the exhalation through the nose can change the location and size of maximum velocity at the top of the head. In the breathing zone, the effect of exhalation through the nose on velocity and temperature distribution was pronounced for the point close to mouth. Also, the exhalation through the nose strongly influences the thermal boundary layer on the breathing zone while it only minimally influences the convective boundary layer on the breathing zone. Overall results demonstrate that it is important to take the exhalation flow into consideration in all areas, especially at a quiescent flow condition with low temperature.

  12. Investigation of Factors Affecting Body Temperature Changes During Routine Clinical Head Magnetic Resonance Imaging

    Science.gov (United States)

    Kim, Myeong Seong

    2016-01-01

    Background Pulsed radiofrequency (RF) magnetic fields, required to produce magnetic resonance imaging (MRI) signals from tissue during the MRI procedure have been shown to heat tissues. Objectives To investigate the relationship between body temperature rise and the RF power deposited during routine clinical MRI procedures, and to determine the correlation between this effect and the body’s physiological response. Patients and Methods We investigated 69 patients from the Korean national cancer center to identify the main factors that contribute to an increase in body temperature (external factors and the body’s response) during a clinical brain MRI. A routine protocol sequence of MRI scans (1.5 T and 3.0 T) was performed. The patient’s tympanic temperature was recorded before and immediately after the MRI procedure and compared with changes in variables related to the body’s physiological response to heat. Results Our investigation of the physiological response to RF heating indicated a link between increasing age and body temperature. A higher increase in body temperature was observed in older patients after a 3.0-T MRI (r = 0.07, P = 0.29 for 1.5-T MRI; r = 0.45, P = 0.002 for 3.0-T MRI). The relationship between age and body heat was related to the heart rate (HR) and changes in HR during the MRI procedure; a higher RF power combined with a reduction in HR resulted in an increase in body temperature. Conclusion A higher magnetic field strength and a decrease in the HR resulted in an increase in body temperature during the MRI procedure. PMID:27895872

  13. Isotopic ordering in eggshells reflects body temperatures and suggests differing thermophysiology in two Cretaceous dinosaurs.

    Science.gov (United States)

    Eagle, Robert A; Enriquez, Marcus; Grellet-Tinner, Gerald; Pérez-Huerta, Alberto; Hu, David; Tütken, Thomas; Montanari, Shaena; Loyd, Sean J; Ramirez, Pedro; Tripati, Aradhna K; Kohn, Matthew J; Cerling, Thure E; Chiappe, Luis M; Eiler, John M

    2015-10-13

    Our understanding of the evolutionary transitions leading to the modern endothermic state of birds and mammals is incomplete, partly because tools available to study the thermophysiology of extinct vertebrates are limited. Here we show that clumped isotope analysis of eggshells can be used to determine body temperatures of females during periods of ovulation. Late Cretaceous titanosaurid eggshells yield temperatures similar to large modern endotherms. In contrast, oviraptorid eggshells yield temperatures lower than most modern endotherms but ∼ 6 °C higher than co-occurring abiogenic carbonates, implying that this taxon did not have thermoregulation comparable to modern birds, but was able to elevate its body temperature above environmental temperatures. Therefore, we observe no strong evidence for end-member ectothermy or endothermy in the species examined. Body temperatures for these two species indicate that variable thermoregulation likely existed among the non-avian dinosaurs and that not all dinosaurs had body temperatures in the range of that seen in modern birds.

  14. Theoretical study on the inverse modeling of deep body temperature measurement

    International Nuclear Information System (INIS)

    Huang, Ming; Chen, Wenxi

    2012-01-01

    We evaluated the theoretical aspects of monitoring the deep body temperature distribution with the inverse modeling method. A two-dimensional model was built based on anatomical structure to simulate the human abdomen. By integrating biophysical and physiological information, the deep body temperature distribution was estimated from cutaneous surface temperature measurements using an inverse quasilinear method. Simulations were conducted with and without the heat effect of blood perfusion in the muscle and skin layers. The results of the simulations showed consistently that the noise characteristics and arrangement of the temperature sensors were the major factors affecting the accuracy of the inverse solution. With temperature sensors of 0.05 °C systematic error and an optimized 16-sensor arrangement, the inverse method could estimate the deep body temperature distribution with an average absolute error of less than 0.20 °C. The results of this theoretical study suggest that it is possible to reconstruct the deep body temperature distribution with the inverse method and that this approach merits further investigation. (paper)

  15. Body temperature responses to handling stress in wintering Black-capped Chickadees (Poecile atricapillus L.).

    Science.gov (United States)

    Lewden, Agnès; Nord, Andreas; Petit, Magali; Vézina, François

    2017-10-01

    Body temperature variation in response to acute stress is typically characterized by peripheral vasoconstriction and a concomitant increase in core body temperature (stress-induced hyperthermia). It is poorly understood how this response differs between species and within individuals of the same species, and how it is affected by the environment. We therefore investigated stress-induced body temperature changes in a non-model species, the Black-capped Chickadee, in two environmental conditions: outdoors in low ambient temperature (mean: -6.6°C), and indoors, in milder ambient temperature close to thermoneutrality (mean: 18.7°C). Our results show that the change in body temperature in response to the same handling stressor differs in these conditions. In cold environments, we noted a significant decrease in core body temperature (-2.9°C), whereas the response in mild indoor conditions was weak and non-significant (-0.6°C). Heat loss in outdoor birds was exacerbated when birds were handled for longer time. This may highlight the role of behavioral thermoregulation and heat substitution from activity to body temperature maintenance in harsh condition. Importantly, our work also indicates that changes in the physical properties of the bird during handling (conductive cooling from cold hands, decreased insulation from compression of plumage and prevention of ptiloerection) may have large consequences for thermoregulation. This might explain why females, the smaller sex, lost more heat than males in the experiment. Because physiological and physical changes during handling may carry over to affect predation risk and maintenance of energy balance during short winter days, we advice caution when designing experimental protocols entailing prolonged handling of small birds in cold conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Melatonin in sleepless children : everything has a rhythm?

    NARCIS (Netherlands)

    van Geijlswijk, I.M.

    2011-01-01

    Every living organism has an biological clock regulating endogenous melatonin production, synchronized by exogenous impulses like daylight, temperature and feeding. Inappropriately applied bright light disturbs this melatonin rhythm. Some large swine producers apply artificial light three times a

  17. RHYTHM STRUCTURE IN NEWS READING

    Directory of Open Access Journals (Sweden)

    Lluís Mas Manchón

    2013-06-01

    Full Text Available Rhythm is central to news reading in radio and television programs. This paper proposes a three level structure for rhythm in news discourse. It gives a comprehensive definition of rhythm and types of rhythm. Firstly, the Base Rhythm Structure consists of semantic and pragmatic rhythmic accents, coincident with very specific words. Secondly, these accents are grouped together according to type, frequency and order, thereby configuring three types of “rhythmic units” (the Internal Rhythm Structure: starting, main and end units. A last structure level presents four discursive factors that are very important in integrating the overall time structure of news announcing (the Melodic Rhythm Structure. This integral structure for news announcing rhythm should be further tested in acoustic-experimental studies under the criterion of information transmission efficacy.

  18. Rhythm information represented in the fronto-parieto-cerebellar motor system.

    Science.gov (United States)

    Konoike, Naho; Kotozaki, Yuka; Miyachi, Shigehiro; Miyauchi, Carlos Makoto; Yomogida, Yukihito; Akimoto, Yoritaka; Kuraoka, Koji; Sugiura, Motoaki; Kawashima, Ryuta; Nakamura, Katsuki

    2012-10-15

    Rhythm is an essential element of human culture, particularly in language and music. To acquire language or music, we have to perceive the sensory inputs, organize them into structured sequences as rhythms, actively hold the rhythm information in mind, and use the information when we reproduce or mimic the same rhythm. Previous brain imaging studies have elucidated brain regions related to the perception and production of rhythms. However, the neural substrates involved in the working memory of rhythm remain unclear. In addition, little is known about the processing of rhythm information from non-auditory inputs (visual or tactile). Therefore, we measured brain activity by functional magnetic resonance imaging while healthy subjects memorized and reproduced auditory and visual rhythmic information. The inferior parietal lobule, inferior frontal gyrus, supplementary motor area, and cerebellum exhibited significant activations during both encoding and retrieving rhythm information. In addition, most of these areas exhibited significant activation also during the maintenance of rhythm information. All of these regions functioned in the processing of auditory and visual rhythms. The bilateral inferior parietal lobule, inferior frontal gyrus, supplementary motor area, and cerebellum are thought to be essential for motor control. When we listen to a certain rhythm, we are often stimulated to move our body, which suggests the existence of a strong interaction between rhythm processing and the motor system. Here, we propose that rhythm information may be represented and retained as information about bodily movements in the supra-modal motor brain system. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Is body temperature an independent predictor of mortality in hip fracture patients?

    Science.gov (United States)

    Faizi, Murtuza; Farrier, Adam J; Venkatesan, Murali; Thomas, Christopher; Uzoigwe, Chika Edward; Balasubramanian, Siva; Smith, Robert P

    2014-12-01

    Admission body temperature is a critical parameter in all trauma patients. Low admission temperature is strongly associated with adverse outcomes. We have previously shown, in a prospective study that low admission body temperature is common and associated with high mortality in hip fracture patients (Uzoigwe et al., 2014). However, no previous studies have evaluated whether admission temperature is an independent predictor of mortality in hip fracture patients after adjustment for the 7 recognised independent prognostic indicators (Maxwell et al., 2008). We retrospectively collated data on all patients presenting to our institution between June 2011 and February 2013 with a hip fracture. This included patients involved in the original prospective study (Uzoigwe et al., 2014). Admission tympanic temperature, measured on initial presentation at triage, was recorded. The prognosticators of age, gender, source of admission, abbreviated mental test score, haemoglobin, co-morbid disease and the presence or absence of malignancy were also recorded. Using multiple logistic regression, adjustment was made for these potentially confounding prognostic indicators of 30-day mortality, to determine if admission low body temperature were independently linked to mortality. 1066 patients were included. 781 patients, involved in the original prospective study (Uzoigwe et al., 2014), presented in the relevant time frame and were included in the retrospective study. The mean age was 81. There were 273 (26%) men and 793 (74%) women. 407 (38%) had low body temperature (temperature had an adjusted odds ratio of 30-day mortality that was 2.1 times that of the euthermic (36.5–37.5 °C). Low body temperature is strongly and independently associated with 30-day mortality in hip fracture patients.

  20. Sleep, performance, circadian rhythms, and light-dark cycles during two space shuttle flights

    Science.gov (United States)

    Dijk, D. J.; Neri, D. F.; Wyatt, J. K.; Ronda, J. M.; Riel, E.; Ritz-De Cecco, A.; Hughes, R. J.; Elliott, A. R.; Prisk, G. K.; West, J. B.; hide

    2001-01-01

    Sleep, circadian rhythm, and neurobehavioral performance measures were obtained in five astronauts before, during, and after 16-day or 10-day space missions. In space, scheduled rest-activity cycles were 20-35 min shorter than 24 h. Light-dark cycles were highly variable on the flight deck, and daytime illuminances in other compartments of the spacecraft were very low (5.0-79.4 lx). In space, the amplitude of the body temperature rhythm was reduced and the circadian rhythm of urinary cortisol appeared misaligned relative to the imposed non-24-h sleep-wake schedule. Neurobehavioral performance decrements were observed. Sleep duration, assessed by questionnaires and actigraphy, was only approximately 6.5 h/day. Subjective sleep quality diminished. Polysomnography revealed more wakefulness and less slow-wave sleep during the final third of sleep episodes. Administration of melatonin (0.3 mg) on alternate nights did not improve sleep. After return to earth, rapid eye movement (REM) sleep was markedly increased. Crewmembers on these flights experienced circadian rhythm disturbances, sleep loss, decrements in neurobehavioral performance, and postflight changes in REM sleep.

  1. Wheel running improves REM sleep and attenuates stress-induced flattening of diurnal rhythms in F344 rats.

    Science.gov (United States)

    Thompson, Robert S; Roller, Rachel; Greenwood, Benjamin N; Fleshner, Monika

    2016-05-01

    Regular physical activity produces resistance to the negative health consequences of stressor exposure. One way that exercise may confer stress resistance is by reducing the impact of stress on diurnal rhythms and sleep; disruptions of which contribute to stress-related disease including mood disorders. Given the link between diurnal rhythm disruptions and stress-related disorders and that exercise both promotes stress resistance and is a powerful non-photic biological entrainment cue, we tested if wheel running could reduce stress-induced disruptions of sleep/wake behavior and diurnal rhythms. Adult, male F344 rats with or without access to running wheels were instrumented for biotelemetric recording of diurnal rhythms of locomotor activity, heart rate, core body temperature (CBT), and sleep (i.e. REM, NREM, and WAKE) in the presence of a 12 h light/dark cycle. Following 6 weeks of sedentary or exercise conditions, rats were exposed to an acute stressor known to disrupt diurnal rhythms and produce behaviors associated with mood disorders. Prior to stressor exposure, exercise rats had higher CBT, more locomotor activity during the dark cycle, and greater %REM during the light cycle relative to sedentary rats. NREM and REM sleep were consolidated immediately following peak running to a greater extent in exercise, compared to sedentary rats. In response to stressor exposure, exercise rats expressed higher stress-induced hyperthermia than sedentary rats. Stressor exposure disrupted diurnal rhythms in sedentary rats; and wheel running reduced these effects. Improvements in sleep and reduced diurnal rhythm disruptions following stress could contribute to the health promoting and stress protective effects of exercise.

  2. Speed over efficiency: locusts select body temperatures that favour growth rate over efficient nutrient utilization

    DEFF Research Database (Denmark)

    Miller, Gabriel A; Clissold, Fiona J; Mayntz, David

    2009-01-01

    Ectotherms have evolved preferences for particular body temperatures, but the nutritional and life-history consequences of such temperature preferences are not well understood. We measured thermal preferences in Locusta migratoria (migratory locusts) and used a multi-factorial experimental design...... to investigate relationships between growth/development and macronutrient utilization (conversion of ingesta to body mass) as a function of temperature. A range of macronutrient intake values for insects at 26, 32 and 38°C was achieved by offering individuals high-protein diets, high-carbohydrate diets...... or a choice between both. Locusts placed in a thermal gradient selected temperatures near 38°C, maximizing rates of weight gain; however, this enhanced growth rate came at the cost of poor protein and carbohydrate utilization. Protein and carbohydrate were equally digested across temperature treatments...

  3. Locatable-body temperature monitoring based on semi-active UHF RFID tags.

    Science.gov (United States)

    Liu, Guangwei; Mao, Luhong; Chen, Liying; Xie, Sheng

    2014-03-26

    This paper presents the use of radio-frequency identification (RFID) technology for the real-time remote monitoring of body temperature, while an associated program can determine the location of the body carrying the respective sensor. The RFID chip's internal integrated temperature sensor is used for both the human-body temperature detection and as a measurement device, while using radio-frequency communication to broadcast the temperature information. The adopted RFID location technology makes use of reference tags together with a nearest neighbor localization algorithm and a multiple-antenna time-division multiplexing location system. A graphical user interface (GUI) was developed for collecting temperature and location data for the data fusion by using RFID protocols. With a puppy as test object, temperature detection and localization experiments were carried out. The measured results show that the applied method, when using a mercury thermometer for comparison in terms of measuring the temperature of the dog, has a good consistency, with an average temperature error of 0.283 °C. When using the associated program over the area of 12.25 m2, the average location error is of 0.461 m, which verifies the feasibility of the sensor-carrier location by using the proposed program.

  4. Locatable-Body Temperature Monitoring Based on Semi-Active UHF RFID Tags

    Directory of Open Access Journals (Sweden)

    Guangwei Liu

    2014-03-01

    Full Text Available This paper presents the use of radio-frequency identification (RFID technology for the real-time remote monitoring of body temperature, while an associated program can determine the location of the body carrying the respective sensor. The RFID chip’s internal integrated temperature sensor is used for both the human-body temperature detection and as a measurement device, while using radio-frequency communication to broadcast the temperature information. The adopted RFID location technology makes use of reference tags together with a nearest neighbor localization algorithm and a multiple-antenna time-division multiplexing location system. A graphical user interface (GUI was developed for collecting temperature and location data for the data fusion by using RFID protocols. With a puppy as test object, temperature detection and localization experiments were carried out. The measured results show that the applied method, when using a mercury thermometer for comparison in terms of measuring the temperature of the dog, has a good consistency, with an average temperature error of 0.283 °C. When using the associated program over the area of 12.25 m2, the average location error is of 0.461 m, which verifies the feasibility of the sensor-carrier location by using the proposed program.

  5. What do foraging wasps optimize in a variable environment, energy investment or body temperature?

    Science.gov (United States)

    Kovac, Helmut; Stabentheiner, Anton; Brodschneider, Robert

    2015-11-01

    Vespine wasps (Vespula sp.) are endowed with a pronounced ability of endothermic heat production. To show how they balance energetics and thermoregulation under variable environmental conditions, we measured the body temperature and respiration of sucrose foragers (1.5 M, unlimited flow) under variable ambient temperature (T a = 20-35 °C) and solar radiation (20-570 W m(-2)). Results revealed a graduated balancing of metabolic efforts with thermoregulatory needs. The thoracic temperature in the shade depended on ambient temperature, increasing from ~37 to 39 °C. However, wasps used solar heat gain to regulate their thorax temperature at a rather high level at low T a (mean T thorax ~ 39 °C). Only at high T a they used solar heat to reduce their metabolic rate remarkably. A high body temperature accelerated the suction speed and shortened foraging time. As the costs of foraging strongly depended on duration, the efficiency could be significantly increased with a high body temperature. Heat gain from solar radiation enabled the wasps to enhance foraging efficiency at high ambient temperature (T a = 30 °C) by up to 63 %. The well-balanced change of economic strategies in response to environmental conditions minimized costs of foraging and optimized energetic efficiency.

  6. Detection of Successful and Unsuccessful Pregnancies in Mice within Hours of Pairing through Frequency Analysis of High Temporal Resolution Core Body Temperature Data.

    Science.gov (United States)

    Smarr, Benjamin L; Zucker, Irving; Kriegsfeld, Lance J

    2016-01-01

    Many controllable factors negatively impact fetal development, underscoring the importance of early pregnancy detection and identification of events that reliably predict potential complications. Clinically, core body temperature (CBT) is used to aid family planning and pregnancy detection. However, such temperature data typically are gathered in single, daily measurements. In animal studies, interventions or cell/tissue harvesting at defined stages of fetal development are arduous, requiring timed mating by trained observers. The value of continuous temperature measurements remains largely unexplored, but the advent of small, inexpensive, and increasingly ubiquitous, accurate sensor devices makes continuous measures feasible. Here, using a mouse model, we show that continuous, 1-min resolution CBT measurements reliably allow for the earliest and most accurate detection of pregnancy (100%, within 14 h of initial pairing), without requiring interaction with the animal for data collection. This method also reveals a subset of females that exhibit a pregnancy-like response following pairing that persists for a variable number of days. Application of wavelet analysis that permits frequency analysis while preserving temporal resolution, uncovers significant differences in ultradian frequencies of CBT; these rhythms are significantly increased in the 12 h after the day of pairing for pregnancies carried to term compared to apparent pregnancies that failed. High temporal resolution CBT and wavelet analysis permit strikingly early detection and separation of successful pregnancies and pregnancy-like events.

  7. Long-term calorie restriction, but not endurance exercise, lowers core body temperature in humans

    Science.gov (United States)

    Soare, Andreea; Cangemi, Roberto; Omodei, Daniela; Holloszy, John O.; Fontana, Luigi

    2011-01-01

    Reduction of body temperature has been proposed to contribute to the increased lifespan in calorie restricted animals and mice overexpressing the uncoupling protein-2 in hypocretin neurons. However, nothing is known regarding the long-term effects of calorie restriction (CR) with adequate nutrition on body temperature in humans. In this study, 24-hour core body temperature was measured every minute by using ingested telemetric capsules in 24 men and women (mean age 53.7±9.4 yrs) consuming a CR diet for an average of 6 years, 24 age- and sex-matched sedentary (WD) and 24 body fat-matched exercise-trained (EX) volunteers, who were eating Western diets. The CR and EX groups were significantly leaner than the WD group. Energy intake was lower in the CR group (1769±348 kcal/d) than in the WD (2302±668 kcal/d) and EX (2798±760 kcal/d) groups (Pbody temperatures were all significantly lower in the CR group than in the WD and EX groups (P≤0.01). Long-term CR with adequate nutrition in lean and weight-stable healthy humans is associated with a sustained reduction in core body temperature, similar to that found in CR rodents and monkeys. This adaptation is likely due to CR itself, rather than to leanness, and may be involved in slowing the rate of aging. PMID:21483032

  8. Infrared thermoimages display of body surface temperature reaction in experimental cholecystitis

    Science.gov (United States)

    Zhang, Dong; Zhu, Yuan-Gen; Wang, Shu-You; Ma, Hui-Min; Ye, Yan-Yan; Fu, Wei-Xing; Hu, Wei-Guo

    2002-01-01

    AIM: To display the thermoimages of the body surface in experimental cholecystitis, to observe the body surface temperature reaction in visceral disorders, and to study if the theory of body surface-viscera correlation is true and the mechanism of temperature changes along the meridians. METHODS: By injecting bacteria suspension into the stricture bile duct and gallbladder, 21 rabbits were prepared as acute pyogenic cholangiocholecystitis models, with another 8 rabbits prepared by the same process except without injection of bacteria suspension as control. The body surface infrared thermoimages were continuously observed on the hair shaven rabbit skin with AGA-782 thermovision 24 h before, 1-11 d after and (2, 3 wk) 4 wk after the operation with a total of over 10 records of thermoimages. RESULTS: Twelve cases out of 21 rabbits with cholecystitis revealed bi-lateral longitudinal high temperature lines in its trunk; with negative findings in the control group. The high-temperature line appeared on d1-d2, first in the right trunk, after the preparation of the model, about 7 d after the model preparation, the lines appeared at the left side too, persisting for 4 wk. The hyper-temperature line revealed 1.1-2.7 °C higher than before the model preparation, 0.7-2.5 °C higher than the surrounding skin. The length of the high temperature line might reach a half length of the body trunk, or as long as the whole body itself. CONCLUSION: The appearance of the longitudinal high temperature lines at the lateral aspects of the trunk in the experimental group is directly bound up with the experimental animals pyogenic cholecystitis, with its running course quite similar to that of the Gallbladder Channel of Foot Shaoyang, but different to the zones of hyperalgesia and site of referred pain in cholecystitis. PMID:11925617

  9. Body temperature and mortality in patients with acute respiratory distress syndrome.

    Science.gov (United States)

    Schell-Chaple, Hildy M; Puntillo, Kathleen A; Matthay, Michael A; Liu, Kathleen D

    2015-01-01

    Little is known about the relationship between body temperature and outcomes in patients with acute respiratory distress syndrome (ARDS). A better understanding of this relationship may provide evidence for fever suppression or warming interventions, which are commonly applied in practice. To examine the relationship between body temperature and mortality in patients with ARDS. Secondary analysis of body temperature and mortality using data from the ARDS Network Fluid and Catheter Treatment Trial (n = 969). Body temperature at baseline and on study day 2, primary cause of ARDS, severity of illness, and 90-day mortality were analyzed by using multiple logistic regression. Mean baseline temperature was 37.5°C (SD, 1.1°C; range, 27.2°C-40.7°C). At baseline, fever (≥ 38.3°C) was present in 23% and hypothermia (temperature was a significant predictor of 90-day mortality after primary cause of ARDS and score on the Acute Physiology and Chronic Health Evaluation III were adjusted for. Higher temperature was associated with decreased mortality: for every 1°C increase in baseline temperature, the odds of death decreased by 15% (odds ratio, 0.85; 95% CI, 0.73-0.98, P = .03). When patients were divided into 5 temperature groups, mortality was lower with higher temperature (P for trend = .02). Early in ARDS, fever is associated with improved survival rates. Fever in the acute phase response to lung injury and its relationship to recovery may be an important factor in determining patients' outcome and warrants further study. ©2015 American Association of Critical-Care Nurses.

  10. Biological Clocks & Circadian Rhythms

    Science.gov (United States)

    Robertson, Laura; Jones, M. Gail

    2009-01-01

    The study of biological clocks and circadian rhythms is an excellent way to address the inquiry strand in the National Science Education Standards (NSES) (NRC 1996). Students can study these everyday phenomena by designing experiments, gathering and analyzing data, and generating new experiments. As students explore biological clocks and circadian…

  11. Biological and physiological rhythms

    Science.gov (United States)

    Strughold, H.; Hale, H. B.

    1975-01-01

    Circadian rhythms, particularly that of sleep and wakefulness, are discussed. The sleep-wakefulness experiences of astronauts during several space missions are described, and predictions are made for future space activities, including Mars missions, interstellar flight, and life on permanent space stations.

  12. Light Rhythms in Architecture

    DEFF Research Database (Denmark)

    Bülow, Katja

    2013-01-01

    formation and rhythm. When integrated into an architectural concept, electrical lighting non-intended for poetic composition has the ability to contribute to place, time, and function-telling aspects of places in urban contexts. Urban environments are information wise challenging to pre-historic human...

  13. Dynamics and complexity of body temperature in preterm infants nursed in incubators.

    Science.gov (United States)

    Jost, Kerstin; Pramana, Isabelle; Delgado-Eckert, Edgar; Kumar, Nitin; Datta, Alexandre N; Frey, Urs; Schulzke, Sven M

    2017-01-01

    Poor control of body temperature is associated with mortality and major morbidity in preterm infants. We aimed to quantify its dynamics and complexity to evaluate whether indices from fluctuation analyses of temperature time series obtained within the first five days of life are associated with gestational age (GA) and body size at birth, and presence and severity of typical comorbidities of preterm birth. We recorded 3h-time series of body temperature using a skin electrode in incubator-nursed preterm infants. We calculated mean and coefficient of variation of body temperature, scaling exponent alpha (Talpha) derived from detrended fluctuation analysis, and sample entropy (TSampEn) of temperature fluctuations. Data were analysed by multilevel multivariable linear regression. Data of satisfactory technical quality were obtained from 285/357 measurements (80%) in 73/90 infants (81%) with a mean (range) GA of 30.1 (24.0-34.0) weeks. We found a positive association of Talpha with increasing levels of respiratory support after adjusting for GA and birth weight z-score (pbody temperature in incubator-nursed preterm infants show considerable associations with GA and respiratory morbidity. Talpha may be a useful marker of autonomic maturity and severity of disease in preterm infants.

  14. Review Article Clockworks in the Central and Peripheral Organs: from Clock-related Genes to the Physiological and Pathological Rhythms

    OpenAIRE

    Moriya, Takahiro; Shinohara, Kazuyuki

    2003-01-01

    Daily rhythms such as sleep-wake, feeding, and the core body temperature, persist with a period of approximately 24 hr even in the absence of environmental time cues, suggesting the existence of an endogenous time-keeping system, the circadian clock. In mammals, the circadian clock is located in the suprachiasmatic nucleus of the hypothalamus (SCN). Recently, a number of studies have revealed that circadian oscillations in the SCN are driven by the intracellular transcriptional and post-trans...

  15. Validity of Devices That Assess Body Temperature During Outdoor Exercise in the Heat

    Science.gov (United States)

    Casa, Douglas J; Becker, Shannon M; Ganio, Matthew S; Brown, Christopher M; Yeargin, Susan W; Roti, Melissa W; Siegler, Jason; Blowers, Julie A; Glaviano, Neal R; Huggins, Robert A; Armstrong, Lawrence E; Maresh, Carl M

    2007-01-01

    Context: Rectal temperature is recommended by the National Athletic Trainers' Association as the criterion standard for recognizing exertional heat stroke, but other body sites commonly are used to measure temperature. Few authors have assessed the validity of the thermometers that measure body temperature at these sites in athletic settings. Objective: To assess the validity of commonly used temperature devices at various body sites during outdoor exercise in the heat. Design: Observational field study. Setting: Outdoor athletic facilities. Patients or Other Participants: Fifteen men and 10 women (age = 26.5 ± 5.3 years, height = 174.3 ± 11.1 cm, mass = 72.73 ± 15.95 kg, body fat = 16.2 ± 5.5%). Intervention(s): We simultaneously tested inexpensive and expensive devices orally and in the axillary region, along with measures of aural, gastrointestinal, forehead, temporal, and rectal temperatures. Temporal temperature was measured according to the instruction manual and a modified method observed in medical tents at local road races. We also measured forehead temperatures directly on the athletic field (other measures occurred in a covered pavilion) where solar radiation was greater. Rectal temperature was the criterion standard used to assess the validity of all other devices. Subjects' temperatures were measured before exercise, every 60 minutes during 180 minutes of exercise, and every 20 minutes for 60 minutes of postexercise recovery. Temperature devices were considered invalid if the mean bias (average difference between rectal temperature and device temperature) was greater than ±0.27°C (±0.5°F). Main Outcome Measure(s): Temperature from each device at each site and time point. Results: Mean bias for the following temperatures was greater than the allowed limit of ±0.27°C (±0.5°F): temperature obtained via expensive oral device (−1.20°C [−2.17°F]), inexpensive oral device (−1.67°C [−3.00°F]), expensive axillary device (−2.58°C [−4

  16. Headset Bluetooth and cell phone based continuous central body temperature measurement system.

    Science.gov (United States)

    Sanches, J Miguel; Pereira, Bruno; Paiva, Teresa

    2010-01-01

    The accurate measure of the central temperature is a very important physiologic indicator in several clinical applications, namely, in the characterization and diagnosis of sleep disorders. In this paper a simple system is described to continuously measure the body temperature at the ear. An electronic temperature sensor is coupled to the microphone of a common commercial auricular Bluetooth device that sends the temperature measurements to a mobile phone to which is paired. The measurements are stored at the mobile phone and periodically sent to a medical facility by email or SMS (short messaging service).

  17. Analyzing biological rhythms in clinical trials.

    Science.gov (United States)

    Elkum, Naser B; Myles, James D; Kumar, Pranesh

    2008-09-01

    The human body exhibits a variety of biological rhythms. There are patterns that correspond, among others, to the daily wake / sleep cycle, a yearly seasonal cycle and, in women, the menstrual cycle. Sine/cosine functions are often used to model biological patterns for continuous data, but this model is not appropriate for analysis of biological rhythms in failure time data. We consider a method appropriate for analysis of biological rhythms in clinical trials. We present a method to provide an estimate and confidence interval of the time when the minimum hazard is achieved. A motivating example from a clinical trial of adjuvant of pre-menopausal breast cancer patients provides an important illustration of the methodology in practice. Adapting the Cosinor method to the Weibull proportional hazards model is proposed as useful way of modeling the biological rhythm data. It presents a method to estimate the time that achieves the minimum hazard along with its associated confidence interval. The application of this technique to the breast cancer data revealed that the optimal day for pre-resection incisional or excisional biopsy of 28-day cycle (i.e. the day associated with the lowest recurrence rate) is day 8 with 95% CI 5-10. We found that older age, fewer positive nodes, smaller tumor size, and experimental treatment are important prognostic factors of longer relapse-free survival. The analysis of biological/circadian rhythms is usually handled by Cosinor rhythmometry method. However, in FTD this is simply not possible. In this case, we propose to adapt the Cosinor method to the Weibull proportional hazard model. The advantage of the proposed method is its ability to model survival data. This method is not limited to breast cancer data, and may be applied to any biological rhythms linked to right censored data.

  18. Individual differences in normal body temperature: longitudinal big data analysis of patient records.

    Science.gov (United States)

    Obermeyer, Ziad; Samra, Jasmeet K; Mullainathan, Sendhil

    2017-12-13

    To estimate individual level body temperature and to correlate it with other measures of physiology and health. Observational cohort study. Outpatient clinics of a large academic hospital, 2009-14. 35 488 patients who neither received a diagnosis for infections nor were prescribed antibiotics, in whom temperature was expected to be within normal limits. Baseline temperatures at individual level, estimated using random effects regression and controlling for ambient conditions at the time of measurement, body site, and time factors. Baseline temperatures were correlated with demographics, medical comorbidities, vital signs, and subsequent one year mortality. In a diverse cohort of 35 488 patients (mean age 52.9 years, 64% women, 41% non-white race) with 243 506 temperature measurements, mean temperature was 36.6°C (95% range 35.7-37.3°C, 99% range 35.3-37.7°C). Several demographic factors were linked to individual level temperature, with older people the coolest (-0.021°C for every decade, Ptemperature (eg, hypothyroidism: -0.013°C, P=0.01) or higher temperature (eg, cancer: 0.020, Ptemperature variation. Despite this, unexplained temperature variation was a significant predictor of subsequent mortality: controlling for all measured factors, an increase of 0.149°C (1 SD of individual temperature in the data) was linked to 8.4% higher one year mortality (P=0.014). Individuals' baseline temperatures showed meaningful variation that was not due solely to measurement error or environmental factors. Baseline temperatures correlated with demographics, comorbid conditions, and physiology, but these factors explained only a small part of individual temperature variation. Unexplained variation in baseline temperature, however, strongly predicted mortality. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  19. Individual differences in normal body temperature: longitudinal big data analysis of patient records

    Science.gov (United States)

    Samra, Jasmeet K; Mullainathan, Sendhil

    2017-01-01

    Abstract Objective To estimate individual level body temperature and to correlate it with other measures of physiology and health. Design Observational cohort study. Setting Outpatient clinics of a large academic hospital, 2009-14. Participants 35 488 patients who neither received a diagnosis for infections nor were prescribed antibiotics, in whom temperature was expected to be within normal limits. Main outcome measures Baseline temperatures at individual level, estimated using random effects regression and controlling for ambient conditions at the time of measurement, body site, and time factors. Baseline temperatures were correlated with demographics, medical comorbidities, vital signs, and subsequent one year mortality. Results In a diverse cohort of 35 488 patients (mean age 52.9 years, 64% women, 41% non-white race) with 243 506 temperature measurements, mean temperature was 36.6°C (95% range 35.7-37.3°C, 99% range 35.3-37.7°C). Several demographic factors were linked to individual level temperature, with older people the coolest (–0.021°C for every decade, Ptemperature (eg, hypothyroidism: –0.013°C, P=0.01) or higher temperature (eg, cancer: 0.020, Pbody mass index: 0.002 per m/kg2, Ptemperature variation. Despite this, unexplained temperature variation was a significant predictor of subsequent mortality: controlling for all measured factors, an increase of 0.149°C (1 SD of individual temperature in the data) was linked to 8.4% higher one year mortality (P=0.014). Conclusions Individuals’ baseline temperatures showed meaningful variation that was not due solely to measurement error or environmental factors. Baseline temperatures correlated with demographics, comorbid conditions, and physiology, but these factors explained only a small part of individual temperature variation. Unexplained variation in baseline temperature, however, strongly predicted mortality. PMID:29237616

  20. Standing down Straight: Jump Rhythm Technique's Rhythm-Driven, Community-Directed Approach to Dance Education

    Science.gov (United States)

    Siegenfeld, Billy

    2009-01-01

    "Standing down straight" means to stand on two feet with both stability and relaxation. Using standing down straight as the foundation of class work, Jump Rhythm Technique offers a fresh alternative to conventional systems of dance study. It bases its pedagogy on three behaviors: grounding the body so that it can move with power and efficiency,…

  1. Novel Zero-Heat-Flux Deep Body Temperature Measurement in Lower Extremity Vascular and Cardiac Surgery.

    Science.gov (United States)

    Mäkinen, Marja-Tellervo; Pesonen, Anne; Jousela, Irma; Päivärinta, Janne; Poikajärvi, Satu; Albäck, Anders; Salminen, Ulla-Stina; Pesonen, Eero

    2016-08-01

    The aim of this study was to compare deep body temperature obtained using a novel noninvasive continuous zero-heat-flux temperature measurement system with core temperatures obtained using conventional methods. A prospective, observational study. Operating room of a university hospital. The study comprised 15 patients undergoing vascular surgery of the lower extremities and 15 patients undergoing cardiac surgery with cardiopulmonary bypass. Zero-heat-flux thermometry on the forehead and standard core temperature measurements. Body temperature was measured using a new thermometry system (SpotOn; 3M, St. Paul, MN) on the forehead and with conventional methods in the esophagus during vascular surgery (n = 15), and in the nasopharynx and pulmonary artery during cardiac surgery (n = 15). The agreement between SpotOn and the conventional methods was assessed using the Bland-Altman random-effects approach for repeated measures. The mean difference between SpotOn and the esophageal temperature during vascular surgery was+0.08°C (95% limit of agreement -0.25 to+0.40°C). During cardiac surgery, during off CPB, the mean difference between SpotOn and the pulmonary arterial temperature was -0.05°C (95% limits of agreement -0.56 to+0.47°C). Throughout cardiac surgery (on and off CPB), the mean difference between SpotOn and the nasopharyngeal temperature was -0.12°C (95% limits of agreement -0.94 to+0.71°C). Poor agreement between the SpotOn and nasopharyngeal temperatures was detected in hypothermia below approximately 32°C. According to this preliminary study, the deep body temperature measured using the zero-heat-flux system was in good agreement with standard core temperatures during lower extremity vascular and cardiac surgery. However, agreement was questionable during hypothermia below 32°C. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Deep-body temperature changes in rats exposed to chronic centrifugation.

    Science.gov (United States)

    Oyama, J.; Platt, W. T.; Holland, V. B.

    1971-01-01

    Deep-body temperature was monitored continuously by implant biotelemetry in unrestrained rats before, during, and after exposure to prolonged and almost continuous centrifugation. Rats subjected to centrifugation for the first time at various G loads ranging up to 2.5 G show a rapid and significant fall in temperature which is sustained below normal levels for periods as long as 3 days. The magnitude of the temperature fall and the recovery time were generally proportional to the G load imposed. The initial fall and recovery of body temperature closely parallels the decrease in food consumption and to a lesser degree the decrease in body mass experienced by centrifuged rats. After exposure to 2 weeks of centrifugation, rats show either no change or only a small transient increase in temperature when decelerated to a lower G level or when returned to normal gravity. Rats repeatedly exposed to centrifugation consistently showed a smaller temperature response compared to the initial exposure. Implant temperature biotelemetry has been found to be a sensitive, reliable, and extremely useful technique for assessing the initial stress of centrifugation and in monitoring the time course of recovery and acclimation of rats to increase as well as*decrease G.

  3. Effect of the temperature-humidity index on body temperature and conception rate of lactating dairy cows in southwestern Japan.

    Science.gov (United States)

    Nabenishi, Hisashi; Ohta, Hiroshi; Nishimoto, Toshihumi; Morita, Tetsuo; Ashizawa, Koji; Tsuzuki, Yasuhiro

    2011-09-01

    In the present study, we investigated the relationship between the temperature-humidity index (THI) and the conception rate of lactating dairy cows in southwestern Japan, one of the hottest areas of the country. We also investigated the relationship between measurement of the vaginal temperature of lactating dairy cows as their core body temperature at one-hour intervals for 25 consecutive days in hot (August-September, n=6) and cool (January-February, n=5) periods and their THI. Furthermore, we discussed the above relationship using these vaginal temperatures, the conception rates and the THI. As a result, when the conception rates from day 2 to 0 before AI were classified into day 2, 1 and 0 groups by the six maximum THI values in each group (mTHI; 80), only the conception rate for the mTHI over 80 at 1 day before AI group was significantly lower (Pconception rate for days 15 to 17, but not days 19 to 22 and 30 to 35, after AI in the cows that experienced average mTHI over 80 (amTHI>80) was significantly lower (P80. There was a significant positive correlation (Pconception rates and vaginal temperatures for all mTHI classes, in the mTHI>80 at 1 day before AI group, the vaginal temperature increased by 0.6 C from 38.7 C, resulting in a reduction of 11.6% in the conception rate from 40.5%. In conclusion, these results suggest that one of the causes of the fall in conception rate of lactating dairy cows during the summer season in southwestern Japan may be an increase in their core body temperature with a higher mTHI than the critical mTHI of 69 at 1 day before AI.

  4. Light pollution modifies the expression of daily rhythms and behavior patterns in a nocturnal primate.

    Science.gov (United States)

    Le Tallec, Thomas; Perret, Martine; Théry, Marc

    2013-01-01

    Among anthropogenic pressures, light pollution altering light/dark cycles and changing the nocturnal component of the environment constitutes a threat for biodiversity. Light pollution is widely spread across the world and continuously growing. However, despite the efforts realized to describe and understand the effects of artificial lighting on fauna, few studies have documented its consequences on biological rhythms, behavioral and physiological functions in nocturnal mammals. To determine the impacts of light pollution on nocturnal mammals an experimental study was conducted on a nocturnal primate, the grey mouse lemur Microcebus murinus. Male mouse lemurs (N = 8) were exposed 14 nights to moonlight treatment and then exposed 14 nights to light pollution treatment. For both treatments, chronobiological parameters related to locomotor activity and core temperature were recorded using telemetric transmitters. In addition, at the end of each treatment, the 14(th) night, nocturnal and feeding behaviors were explored using an infrared camera. Finally, throughout the study, body mass and daily caloric food intake were recorded. For the first time in a nocturnal primate, light pollution was demonstrated to modify daily rhythms of locomotor activity and core temperature especially through phase delays and increases in core temperature. Moreover, nocturnal activity and feeding behaviors patterns were modified negatively. This study suggests that light pollution induces daily desynchronization of biological rhythms and could lead to seasonal desynchronization with potential deleterious consequences for animals in terms of adaptation and anticipation of environmental changes.

  5. Light Pollution Modifies the Expression of Daily Rhythms and Behavior Patterns in a Nocturnal Primate

    Science.gov (United States)

    Le Tallec, Thomas; Perret, Martine; Théry, Marc

    2013-01-01

    Among anthropogenic pressures, light pollution altering light/dark cycles and changing the nocturnal component of the environment constitutes a threat for biodiversity. Light pollution is widely spread across the world and continuously growing. However, despite the efforts realized to describe and understand the effects of artificial lighting on fauna, few studies have documented its consequences on biological rhythms, behavioral and physiological functions in nocturnal mammals. To determine the impacts of light pollution on nocturnal mammals an experimental study was conducted on a nocturnal primate, the grey mouse lemur Microcebus murinus. Male mouse lemurs (N = 8) were exposed 14 nights to moonlight treatment and then exposed 14 nights to light pollution treatment. For both treatments, chronobiological parameters related to locomotor activity and core temperature were recorded using telemetric transmitters. In addition, at the end of each treatment, the 14th night, nocturnal and feeding behaviors were explored using an infrared camera. Finally, throughout the study, body mass and daily caloric food intake were recorded. For the first time in a nocturnal primate, light pollution was demonstrated to modify daily rhythms of locomotor activity and core temperature especially through phase delays and increases in core temperature. Moreover, nocturnal activity and feeding behaviors patterns were modified negatively. This study suggests that light pollution induces daily desynchronization of biological rhythms and could lead to seasonal desynchronization with potential deleterious consequences for animals in terms of adaptation and anticipation of environmental changes. PMID:24236115

  6. Light pollution modifies the expression of daily rhythms and behavior patterns in a nocturnal primate.

    Directory of Open Access Journals (Sweden)

    Thomas Le Tallec

    Full Text Available Among anthropogenic pressures, light pollution altering light/dark cycles and changing the nocturnal component of the environment constitutes a threat for biodiversity. Light pollution is widely spread across the world and continuously growing. However, despite the efforts realized to describe and understand the effects of artificial lighting on fauna, few studies have documented its consequences on biological rhythms, behavioral and physiological functions in nocturnal mammals. To determine the impacts of light pollution on nocturnal mammals an experimental study was conducted on a nocturnal primate, the grey mouse lemur Microcebus murinus. Male mouse lemurs (N = 8 were exposed 14 nights to moonlight treatment and then exposed 14 nights to light pollution treatment. For both treatments, chronobiological parameters related to locomotor activity and core temperature were recorded using telemetric transmitters. In addition, at the end of each treatment, the 14(th night, nocturnal and feeding behaviors were explored using an infrared camera. Finally, throughout the study, body mass and daily caloric food intake were recorded. For the first time in a nocturnal primate, light pollution was demonstrated to modify daily rhythms of locomotor activity and core temperature especially through phase delays and increases in core temperature. Moreover, nocturnal activity and feeding behaviors patterns were modified negatively. This study suggests that light pollution induces daily desynchronization of biological rhythms and could lead to seasonal desynchronization with potential deleterious consequences for animals in terms of adaptation and anticipation of environmental changes.

  7. Integration of body temperature into the analysis of energy expenditure in the mouse

    Directory of Open Access Journals (Sweden)

    Gustavo Abreu-Vieira

    2015-06-01

    Conclusions: At 22 °C, cold-induced thermogenesis is ∼120% of basal metabolic rate. The higher body temperature during physical activity is due to a higher set point, not simply increased heat generation during exercise. Most insulation in mice is via physiological mechanisms, with little from fur or fat. Our analysis suggests that the definition of the upper limit of the thermoneutral zone should be re-considered. Measuring body temperature informs interpretation of energy expenditure data and improves the predictiveness and utility of the mouse to model human energy homeostasis.

  8. Comparison of estimated core body temperature measured with the BioHarness and rectal temperature under several heat stress conditions.

    Science.gov (United States)

    Seo, Yongsuk; DiLeo, Travis; Powell, Jeffrey B; Kim, Jung-Hyun; Roberge, Raymond J; Coca, Aitor

    2016-08-01

    Monitoring and measuring core body temperature is important to prevent or minimize physiological strain and cognitive dysfunction for workers such as first responders (e.g., firefighters) and military personnel. The purpose of this study is to compare estimated core body temperature (Tco-est), determined by heart rate (HR) data from a wearable chest strap physiology monitor, to standard rectal thermometry (Tre) under different conditions.  Tco-est and Tre measurements were obtained in thermoneutral and heat stress conditions (high temperature and relative humidity) during four different experiments including treadmill exercise, cycling exercise, passive heat stress, and treadmill exercise while wearing personal protective equipment (PPE).  Overall, the mean Tco-est did not differ significantly from Tre across the four conditions. During exercise at low-moderate work rates under heat stress conditions, Tco-est was consistently higher than Tre at all-time points. Tco-est underestimated temperature compared to Tre at rest in heat stress conditions and at a low work rate under heat stress while wearing PPE. The mean differences between the two measurements ranged from -0.1 ± 0.4 to 0.3 ± 0.4°C and Tco-est correlated well with HR (r = 0.795 - 0.849) and mean body temperature (r = 0.637 - 0.861).  These results indicate that, the comparison of Tco-est to Tre may result in over- or underestimation which could possibly lead to heat-related illness during monitoring in certain conditions. Modifications to the current algorithm should be considered to address such issues.

  9. A circadian rhythm regulating hyphal melanization in Cercospora kikuchii.

    Science.gov (United States)

    Bluhm, Burton H; Burnham, A Michele; Dunkle, Larry D

    2010-01-01

    Many metabolic and developmental processes in fungi are controlled by biological rhythms. Circadian rhythms approximate a daily (24 h) cycle and have been thoroughly studied in the model fungus, Neurospora crassa. However relatively few examples of true circadian rhythms have been documented among other filamentous fungi. In this study we describe a circadian rhythm underlying hyphal melanization in Cercospora kikuchii, an important pathogen of soybean. After growth in light or light : dark cycles, colonies transferred to darkness produced zonate bands of melanized hyphae interspersed with bands of hyaline hyphae. Rhythmic production of bands was remarkably persistent in the absence of external cues, lasting at least 7 d after transfer to darkness, and was compensated over a range of temperatures. As in N. crassa, blue light but not red light was sufficient to entrain the circadian rhythm in C. kikuchii, and a putative ortholog of white collar-1, one of the genes required for light responses in N. crassa, was identified in C. kikuchii. Circadian regulation of melanization is conserved in other members of the genus: Similar rhythms were identified in another field isolate of C. kikuchii as well as field isolates of C. beticola and C. sorghi, but not in wild-type strains of C. zeae-maydis or C. zeina. This report represents the first documented circadian rhythm among Dothideomycete fungi and provides a new opportunity to dissect the molecular basis of circadian rhythms among filamentous fungi.

  10. A pilot study to examine maturation of body temperature control in preterm infants.

    Science.gov (United States)

    Knobel, Robin B; Levy, Janet; Katz, Laurence; Guenther, Bob; Holditch-Davis, Diane

    2013-01-01

    To test instrumentation and develop analytic models to use in a larger study to examine developmental trajectories of body temperature and peripheral perfusion from birth in extremely low-birth-weight (EBLW) infants. A case study design. The study took place in a Level 4 neonatal intensive care unit (NICU) in North Carolina. Four ELBW infants, fewer than 29 weeks gestational age at birth. Physiologic data were measured every minute for the first 5 days of life: peripheral perfusion using perfusion index by Masimo and body temperature using thermistors. Body temperature was also measured using infrared thermal imaging. Stimulation and care events were recorded over the first 5 days using video which was coded with Noldus Observer software. Novel analytical models using the state space approach to time-series analysis were developed to explore maturation of neural control over central and peripheral body temperature. Results from this pilot study confirmed the feasibility of using multiple instruments to measure temperature and perfusion in ELBW infants. This approach added rich data to our case study design and set a clinical context with which to interpret longitudinal physiological data. © 2013 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses.

  11. Human thermoregulation and measurement of body temperature in exercise and clinical settings.

    Science.gov (United States)

    Lim, Chin Leong; Byrne, Chris; Lee, Jason Kw

    2008-04-01

    This review discusses human thermoregulation during exercise and the measurement of body temperature in clinical and exercise settings. The thermoregulatory mechanisms play important roles in maintaining physiological homeostasis during rest and physical exercise. Physical exertion poses a challenge to thermoregulation by causing a substantial increase in metabolic heat production. However, within a non-thermolytic range, the thermoregulatory mechanisms are capable of adapting to sustain physiological functions under these conditions. The central nervous system may also rely on hyperthermia to protect the body from "overheating." Hyperthermia may serve as a self-limiting signal that triggers central inhibition of exercise performance when a temperature threshold is achieved. Exposure to sub-lethal heat stress may also confer tolerance against higher doses of heat stress by inducing the production of heat shock proteins, which protect cells against the thermolytic effects of heat. Advances in body temperature measurement also contribute to research in thermoregulation. Current evidence supports the use of oral temperature measurement in the clinical setting, although it may not be as convenient as tympanic temperature measurement using the infrared temperature scanner. Rectal and oesophagus temperatures are widely accepted surrogate measurements of core temperature (Tc), but they cause discomfort and are less likely to be accepted by users. Gastrointestinal temperature measurement using the ingestible temperature sensor provides an acceptable level of accuracy as a surrogate measure of Tc without causing discomfort to the user. This form of Tc measurement also allows Tc to be measured continuously in the field and has gained wider acceptance in the last decade.

  12. Effects of body temperature on post-anoxic oxidative stress from the perspective of postnatal physiological adaptive processes in rats.

    Science.gov (United States)

    Kletkiewicz, H; Rogalska, J; Nowakowska, A; Wozniak, A; Mila-Kierzenkowska, C; Caputa, M

    2016-04-01

    It is well known that decrease in body temperature provides protection to newborns subjected to anoxia/ischemia. We hypothesized that the normal body temperature of 33°C in neonatal rats (4°C below normal body temperature in adults) is in fact a preadaptation to protect CNS from anoxia and further reductions as well as elevations in temperature may be counterproductive. Our experiments aimed to examine the effect of changes in body temperature on oxidative stress development in newborn rats exposed to anoxia. Two-day-old Wistar rats were divided into 4 temperature groups: i. hypothermic at body temperature of 31°C, ii. maintaining physiological neonatal body temperature of 33°C, iii. forced to maintain hyperthermic temperature of 37°C, and i.v. forced to maintain hyperthermic temperature of 39°C. The temperature was controlled starting 15 minutes before and afterword during 10 minutes of anoxia as well as for 2 hours post-anoxia. Cerebral concentrations of lipid peroxidation products malondialdehyde (MDA) and conjugated dienes (CD) and the activities of antioxidant enzymes had been determined post mortem: immediately after anoxia was finished and 3, 7, and 14 days later. There were no post-anoxic changes in the concentration of MDA, CD and in antioxidant enzymes activity in newborn rats kept at their physiological body temperature of 33°C. In contrast, perinatal anoxia at body temperature elevated to 37°C or 39°C as well as under hypothermic conditions (31°C) intensified post-anoxic oxidative stress and depleted the antioxidant pool. Overall, these findings suggest that elevated body temperature (hyperthermia or fever), as well as exceeding cooling beyond the physiological level of body temperature of newborn rats, may extend perinatal anoxia-induced brain lesions. Our findings provide new insights into the role of body temperature in anoxic insult in vivo.

  13. Core Temperature and Surface Heat Flux During Exercise in Heat While Wearing Body Armor

    Science.gov (United States)

    2015-10-26

    other was used as a suppository (Tc2). Other data included height, weight, HF and Ts from 6 locations (forehead, sternum, pectoral muscle , scapula...from the changes in clothed weights. Instrumentation for Chamber Testing Heart rate (including ECG waveform), skin temperature, respiration ...rate (including respiration effort waveform), activity level using accelerometry data, and body core temperature were measured every 15 s by a chest

  14. Method for solving the problem of nonlinear heating a cylindrical body with unknown initial temperature

    Science.gov (United States)

    Yaparova, N.

    2017-10-01

    We consider the problem of heating a cylindrical body with an internal thermal source when the main characteristics of the material such as specific heat, thermal conductivity and material density depend on the temperature at each point of the body. We can control the surface temperature and the heat flow from the surface inside the cylinder, but it is impossible to measure the temperature on axis and the initial temperature in the entire body. This problem is associated with the temperature measurement challenge and appears in non-destructive testing, in thermal monitoring of heat treatment and technical diagnostics of operating equipment. The mathematical model of heating is represented as nonlinear parabolic PDE with the unknown initial condition. In this problem, both the Dirichlet and Neumann boundary conditions are given and it is required to calculate the temperature values at the internal points of the body. To solve this problem, we propose the numerical method based on using of finite-difference equations and a regularization technique. The computational scheme involves solving the problem at each spatial step. As a result, we obtain the temperature function at each internal point of the cylinder beginning from the surface down to the axis. The application of the regularization technique ensures the stability of the scheme and allows us to significantly simplify the computational procedure. We investigate the stability of the computational scheme and prove the dependence of the stability on the discretization steps and error level of the measurement results. To obtain the experimental temperature error estimates, computational experiments were carried out. The computational results are consistent with the theoretical error estimates and confirm the efficiency and reliability of the proposed computational scheme.

  15. Thermal conditions influence changes in body temperature induced by intragastric administration of capsaicin in mice.

    Science.gov (United States)

    Mori, Noriyuki; Urata, Tomomi; Fukuwatari, Tsutomu

    2016-08-01

    Capsaicin has been reported to have unique thermoregulatory actions. However, changes in core temperature after the administration of capsaicin are a controversial point. Therefore, we investigated the effects of environmental thermal conditions on changes in body temperature caused by capsaicin in mice. We showed that intragastric administration of 10 and 15 mg/kg capsaicin increased tail temperature and decreased colonic temperatures in the core temperature (CT)-constant and CT-decreasing conditions. In the CT-increasing condition, 15 mg/kg capsaicin increased tail temperature and decreased colonic temperature. However, 10 mg/kg capsaicin increased colonic temperature. Furthermore, the amount of increase in tail temperature was greater in the CT-decreasing condition and lower in the CT-increasing condition, compared with that of the CT-constant condition. These findings suggest that the changes in core temperature were affected by the environmental thermal conditions and that preliminary thermoregulation state might be more important than the constancy of temperature to evaluate the effects of heat diffusion and thermogensis.

  16. Mechanically Enhanced Liquid Interfaces at Human Body Temperature Using Thermosensitive Methylated Nanocrystalline Cellulose.

    Science.gov (United States)

    Scheuble, N; Geue, T; Kuster, S; Adamcik, J; Mezzenga, R; Windhab, E J; Fischer, P

    2016-02-09

    The mechanical performance of materials at oil/water interfaces after consumption is a key factor affecting hydrophobic drug release. In this study, we methylated the surface of nanocrystalline cellulose (NCC) by mercerization and dimethyl sulfate exposure to produce thermosensitive biopolymers. These methylated NCC (metNCC) were used to investigate interfacial thermogelation at air/water and medium-chain triglyceride (MCT)/water interfaces at body temperature. In contrast to bulk fluid dynamics, elastic layers were formed at room temperature, and elasticity increased significantly at body temperature, which was measured by interfacial shear and dilatational rheology in situ. This unique phenomenon depends on solvent quality, temperature, and polymer concentration at interfaces. Thus, by adjusting the degree of hydrophobicity of metNCC, the interfacial elasticity and thermogelation of the interfaces could be varied. In general, these new materials (metNCC) formed more brittle interfacial layers compared to commercial methylcellulose (MC A15). Thermogelation of methylcellulose promotes attractive intermolecular forces, which were reflected in a change in self-assembly of metNCC at the interface. As a consequence, layer thickness and density increased as a function of temperature. These effects were measured by atomic force microscopy (AFM) images of the displaced interface and confirmed by neutron reflection. The substantial structural and mechanical change of methylcellulose interfaces at body temperature represents a controllable encapsulation parameter allowing optimization of lipid-based drug formulations.

  17. Effect of paracetamol (acetaminophen) on body temperature in acute stroke: A meta-analysis.

    Science.gov (United States)

    Fang, Junjie; Chen, Chensong; Cheng, Hongsen; Wang, Ren; Ma, Linhao

    2017-10-01

    The objective of this study was to assess the efficacy of paracetamol (acetaminophen) on body temperature in acute stroke. Medline, Cochrane Central Register of Controlled Trials, EMBASE, Chinese BioMedical Literature Database, China National Knowledge Infrastructure, and the World Health Organization (WHO) International Clinical Trials Registry Platform were searched electronically. Relevant journals and references of studies included were hand-searched for randomized controlled trials (RCT) and controlled clinical trials (CCT) regarding the efficacy of paracetamol (acetaminophen) on body temperature in acute stroke. Two reviewers independently performed data extraction and quality assessment. Data were analyzed using RevMan 5.3 software by the Cochrane Collaboration. Five studies were included. To compare the efficacy of paracetamol (acetaminophen) in acute stroke, the pooled RR (Risk Ratio) and its 95% CI of body temperature reduction at 24h from the start of treatment were -0.3 (95% CI: -0.52 to -0.08), with statistical significance (P=0.007). Consistently, the pooled RR (Risk Ratio) and its 95% CI of body temperature at 24h from the start of treatment were -0.22 (-0.29, -0.15), with statistical significance (Pbody temperature reduction after 5days from the start of treatment, the pooled RR (Risk Ratio) and its 95% CI were 0.04 (95% CI: -0.20 to 0.29), with no statistical significance (P=0.73). For functional outcome (mRS≤2) analysis, the pooled RR and its 95% CI were 1.08 (0.88, 1.32), with no statistical significance (P=0.45). In addition, the difference of serious adverse events between acetaminophen and placebo was 0.86 (95% CI: 0.62 to 1.2), with no statistical significance (P=0.27). Acetaminophen was revealed to have some favorable influence in body temperature reduction in acute stroke, but showed no important effect on improving functional outcome and reducing adverse events of patients. What is already known on this subject? Paracetamol

  18. Circadian rhythm and menopause.

    Science.gov (United States)

    Pines, A

    2016-12-01

    Circadian rhythm is an internal biological clock which initiates and monitors various physiological processes with a fixed time-related schedule. The master circadian pacemaker is located in the suprachiasmatic nucleus in the hypothalamus. The circadian clock undergoes significant changes throughout the life span, at both the physiological and molecular levels. This cyclical physiological process, which is very complex and multifactorial, may be associated with metabolic alterations, atherosclerosis, impaired cognition, mood disturbances and even development of cancer. Sex differences do exist, and the well-known sleep disturbances associated with menopause are a good example. Circadian rhythm was detected in the daily pattern of hot flushes, with a peak in the afternoons. Endogenous secretion of melatonin decreases with aging across genders, and, among women, menopause is associated with a significant reduction of melatonin levels, affecting sleep. Although it might seem that hot flushes and melatonin secretion are likely related, there are not enough data to support such a hypothesis.

  19. Biomarkers for circadian rhythm disruption independent of time of day.

    Directory of Open Access Journals (Sweden)

    Kirsten C G Van Dycke

    Full Text Available Frequent shift work causes disruption of the circadian rhythm and might on the long-term result in increased health risk. Current biomarkers evaluating the presence of circadian rhythm disturbance (CRD, including melatonin, cortisol and body temperature, require 24-hr ("around the clock" measurements, which is tedious. Therefore, these markers are not eligible to be used in large-scale (human studies. The aim of the present study was to identify universal biomarkers for CRD independent of time of day using a transcriptomics approach. Female FVB mice were exposed to six shifts in a clockwise (CW and counterclockwise (CCW CRD protocol and sacrificed at baseline and after 1 shift, 6 shifts, 5 days recovery and 14 days recovery, respectively. At six time-points during the day, livers were collected for mRNA microarray analysis. Using a classification approach, we identified a set of biomarkers able to classify samples into either CRD or non-disrupted based on the hepatic gene expression. Furthermore, we identified differentially expressed genes 14 days after the last shift compared to baseline for both CRD protocols. Non-circadian genes differentially expressed upon both CW and CCW protocol were considered useful, universal markers for CRD. One candidate marker i.e. CD36 was evaluated in serum samples of the CRD animals versus controls. These biomarkers might be useful to measure CRD and can be used later on for monitoring the effectiveness of intervention strategies aiming to prevent or minimize chronic adverse health effects.

  20. Circadian rhythms on skin function of hairless rats: light and thermic influences.

    Science.gov (United States)

    Flo, Ana; Díez-Noguera, Antoni; Calpena, Ana C; Cambras, Trinitat

    2014-03-01

    Circadian rhythms are present in most functions of living beings. We have demonstrated the presence of circadian rhythms in skin variables (transepidermal water loss, TEWL; stratum corneum hydration, SCH; and skin temperature) in hairless rats under different environmental conditions of light and temperature. Circadian rhythms in TEWL and SCH showed mean amplitudes of about 20% and 14% around the mean, respectively, and appeared under light-dark cycles as well as under constant darkness. Environmental temperature was able to override TEWL, but not SCH rhythm, evidencing the dependency of TEWL on the temperature. Mean daily values of TEWL and SCH, and also the amplitude of TEWL rhythm, increased with the age of the animal. Under constant light, situation that induces arrhythmicity in rats, SCH and TEWL were inversely correlated. The results suggest the importance to take into account the functional skin rhythms in research in dermatological sciences. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. The relationship of normal body temperature, end-expired breath temperature, and BAC/BrAC ratio in 98 physically fit human test subjects.

    Science.gov (United States)

    Cowan, J Mack; Burris, James M; Hughes, James R; Cunningham, Margaret P

    2010-06-01

    The relationship between normal body temperature, end-expired breath temperature, and blood alcohol concentration (BAC)/breath alcohol concentration (BrAC) ratio was studied in 98 subjects (84 men, 14 women). Subjects consumed alcohol sufficient to produce a BrAC of at least 0.06 g/210 L 45-75 min after drinking. Breath samples were analyzed using an Intoxilyzer 8000 specially equipped to measure breath temperature. Venous blood samples and body temperatures were then taken. The mean body temperature of the men (36.6 degrees C) was lower than the women (37.0 degrees C); however, their mean breath temperatures were virtually identical (men: 34.5 degrees C; women: 34.6 degrees C). The BAC exceeded the BrAC for every subject. BAC/BrAC ratios were calculated from the BAC and BrAC analytical results. There was no difference in the BAC/BrAC ratios for men (1:2379) and women (1:2385). The correlation between BAC and BrAC was high (r = 0.938, p body temperature and end-expired breath temperature, body temperature and BAC/BrAC ratio, and breath temperature and BAC/BrAC ratio were much lower. Neither normal body temperature nor end-expired breath temperature was strongly associated with BAC/BrAC ratio.

  2. Effects of pregnancy on body temperature and locomotor performance of velvet geckos.

    Science.gov (United States)

    Dayananda, Buddhi; Ibargüengoytía, Nora; Whiting, Martin J; Webb, Jonathan K

    2017-04-01

    Pregnancy is a challenging period for egg laying squamates. Carrying eggs can encumber females and decrease their locomotor performance, potentially increasing their risk of predation. Pregnant females can potentially reduce this handicap by selecting higher temperatures to increase their sprint speed and ability to escape from predators, or to speed up embryonic development and reduce the period during which they are burdened with eggs ('selfish mother' hypothesis). Alternatively, females might select more stable body temperatures during pregnancy to enhance offspring fitness ('maternal manipulation hypothesis'), even if the maintenance of such temperatures compromises a female's locomotor performance. We investigated whether pregnancy affects the preferred body temperatures and locomotor performance of female velvet geckos Amalosia lesueurii. We measured running speed of females during late pregnancy, and one week after they laid eggs at four temperatures (20°, 25°, 30° and 35°C). Preferred body temperatures of females were measured in a cost-free thermal gradient during late pregnancy and one week after egg-laying. Females selected higher and more stable set-point temperatures when they were pregnant (mean =29.0°C, T set =27.8-30.5°C) than when they were non-pregnant (mean =26.2°C, T set =23.7-28.7°C). Pregnancy was also associated with impaired performance; females sprinted more slowly at all four test temperatures when burdened with eggs. Although females selected higher body temperatures during late pregnancy, this increase in temperature did not compensate for their impaired running performance. Hence, our results suggest that females select higher temperatures during pregnancy to speed up embryogenesis and reduce the period during which they have reduced performance. This strategy may decrease a female's probability of encountering predatory snakes that use the same microhabitats for thermoregulation. Selection of stable temperatures by pregnant

  3. Increased core body temperature in astronauts during long-duration space missions

    Czech Academy of Sciences Publication Activity Database

    Stahn, A. C.; Werner, A.; Opatz, O.; Maggioni, M. A.; Steinach, M.; von Ahlefeld, V. W.; Moore, A.; Crucian, B. E.; Smith, S. M.; Zwart, S. R.; Schlabs, T.; Mendt, S.; Trippel, T.; Koralewski, E.; Koch, J.; Chouker, A.; Reitz, Guenther; Shang, P.; Rocker, L.; Kirsch, K. A.; Gunga, H-C.

    2017-01-01

    Roč. 7, č. 11 (2017), č. článku 16180. ISSN 2045-2322 Institutional support: RVO:61389005 Keywords : core body temperature * astonauts' CBT * spaceflights Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering OBOR OECD: Electrical and electronic engineering Impact factor: 4.259, year: 2016

  4. A Quantitative Risk Evaluation Model for Network Security Based on Body Temperature

    Directory of Open Access Journals (Sweden)

    Y. P. Jiang

    2016-01-01

    Full Text Available These days, in allusion to the traditional network security risk evaluation model, which have certain limitations for real-time, accuracy, characterization. This paper proposed a quantitative risk evaluation model for network security based on body temperature (QREM-BT, which refers to the mechanism of biological immune system and the imbalance of immune system which can result in body temperature changes, firstly, through the r-contiguous bits nonconstant matching rate algorithm to improve the detection quality of detector and reduce missing rate or false detection rate. Then the dynamic evolution process of the detector was described in detail. And the mechanism of increased antibody concentration, which is made up of activating mature detector and cloning memory detector, is mainly used to assess network risk caused by various species of attacks. Based on these reasons, this paper not only established the equation of antibody concentration increase factor but also put forward the antibody concentration quantitative calculation model. Finally, because the mechanism of antibody concentration change is reasonable and effective, which can effectively reflect the network risk, thus body temperature evaluation model was established in this paper. The simulation results showed that, according to body temperature value, the proposed model has more effective, real time to assess network security risk.

  5. Software tools for data modelling and processing of human body temperature circadian dynamics.

    Science.gov (United States)

    Petrova, Elena S; Afanasova, Anastasia I

    2015-01-01

    This paper is presenting a software development for simulating and processing thermometry data. The motivation of this research is the miniaturization of actuators attached to human body which allow frequent temperature measurements and improve the medical diagnosis procedures related to circadian dynamics.

  6. Deeply torpid bats can change position without elevation of body temperature

    Czech Academy of Sciences Publication Activity Database

    Bartonička, T.; Banďouchová, H.; Berková, Hana; Blažek, J.; Lučan, R.; Horáček, I.; Martínková, Natália; Pikula, J.; Řehák, Z.; Zukal, Jan

    2017-01-01

    Roč. 63, January (2017), s. 119-123 ISSN 0306-4565 R&D Projects: GA ČR(CZ) GAP506/12/1064 Institutional support: RVO:68081766 Keywords : Body temperature * Hibernation * Locomotor performance * Chiroptera * Flight Subject RIV: EG - Zoology OBOR OECD: Zoology Impact factor: 2.157, year: 2016

  7. The correlation between the amplitude of Osborn wave and core body temperature.

    Science.gov (United States)

    Omar, Hesham R; Camporesi, Enrico M

    2015-08-01

    Several reports illustrate an inverse correlation between the Osborn wave (J wave) amplitude and core body temperature. We attempted to study the strength of this correlation. We reviewed all articles reporting hypothermic J waves from 1950-2014 for patient demographics, core body temperature in Celsius (°C), amplitude of the J wave in millimeters (mm), lead with the highest amplitude of J wave, presence of acidosis, PO2, electrolytes and outcome. In cases with more than one electrocardiogram (ECG), the respective core body temperature and J wave amplitude of each ECG were recorded. The main study outcome is to evaluate the correlation between the J wave amplitude and core body temperature in the admission ECG. We have also examined the strength of this relationship in cases with more than one ECG. We attempted to find the most frequent lead that recorded the highest amplitude of the J wave in addition to the correlation between the amplitude of J wave and pH. We found 64 articles comprising a total of 68 cases. When analyzing only cases with more than one reported ECG, there was a strong inverse correlation (r = - 0.682, ptemperature: however, when analyzing admission ECG of all cases, the correlation was only moderate (r = - 0.410, ptemperature. © The European Society of Cardiology 2014.

  8. A body temperature model for lizards as estimated from the thermal environment

    NARCIS (Netherlands)

    Fei, T.; Skidmore, A.K.; Venus, V.; Wang, T.; Schlerf, M.; Toxopeus, A.G.; Overjijk, van S.; Bian, B.M.; Liu, Y.

    2012-01-01

    A physically based model was built to predict the transient body temperature of lizards in a thermally heterogeneous environment. Six heat transfer terms were taken into account in this model: solar radiation, convective heat flow, longwave radiation, conductive heat flow, metabolic heat gain and

  9. Intracerebral implantation of carbachol in the rat: Its effect on water intake and body temperature

    NARCIS (Netherlands)

    Hulst, S.G.Th.

    Intracerebral carbachol produces a fall in body temperature as well as drinking in the rat when implanted in various subcortical structures, related to the emotion-motivation limbic circuit. These effects are due to a central cholinergic stimulation since they can be prevented by the systemic

  10. Endogenous and exogenous components in the circadian variation of core body temperature in humans

    NARCIS (Netherlands)

    Hiddinga, AE; Beersma, DGM; VandenHoofdakker, RH

    Core body temperature is predominantly modulated by endogenous and exogenous components. In the present study we tested whether these two components can be reliably assessed in a protocol which lasts for only 120 h. In this so-called forced desynchrony protocol, 12 healthy male subjects (age 23.7

  11. Selective SWS suppression does not affect the time course of core body temperature in men

    NARCIS (Netherlands)

    Beersma, Domien G.M.; Dijk, Derk-Jan

    1992-01-01

    In eight healthy middle-aged men, sleep and core body temperature were recorded under baseline conditions, during all-night SWS suppression by acoustic stimulation, and during undisturbed recovery sleep. SWS suppression resulted in a marked reduction of sleep stages 3 and 4 but did not affect the

  12. An IR Sensor Based Smart System to Approximate Core Body Temperature.

    Science.gov (United States)

    Ray, Partha Pratim

    2017-08-01

    Herein demonstrated experiment studies two methods, namely convection and body resistance, to approximate human core body temperature. The proposed system is highly energy efficient that consumes only 165 mW power and runs on 5 VDC source. The implemented solution employs an IR thermographic sensor of industry grade along with AT Mega 328 breakout board. Ordinarily, the IR sensor is placed 1.5-30 cm away from human forehead (i.e., non-invasive) and measured the raw data in terms of skin and ambient temperature which is then converted using appropriate approximation formula to find out core body temperature. The raw data is plotted, visualized, and stored instantaneously in a local machine by means of two tools such as Makerplot, and JAVA-JAR. The test is performed when human object is in complete rest and after 10 min of walk. Achieved results are compared with the CoreTemp CM-210 sensor (by Terumo, Japan) which is calculated to be 0.7 °F different from the average value of BCT, obtained by the proposed IR sensor system. Upon a slight modification, the presented model can be connected with a remotely placed Internet of Things cloud service, which may be useful to inform and predict the user's core body temperature through a probabilistic view. It is also comprehended that such system can be useful as wearable device to be worn on at the hat attachable way.

  13. Differences in oral temperature and body shape in two populations with different propensities for obesity

    DEFF Research Database (Denmark)

    Vozarova, B; Weyer, C; Bogardus, C

    2002-01-01

    Body temperature is a function of heat production and heat dissipation. Substantial interindividual variability has been reported in healthy humans. We hypothesized that Pima Indians, a population with a high prevalence of abdominal obesity, may have a lower surface area relative to volume, that ...

  14. Circadian Rhythm Disturbances in Patients with Alzheimer's Disease: A Review

    Directory of Open Access Journals (Sweden)

    Dawit A. Weldemichael

    2010-01-01

    Full Text Available Circadian Rhythm Disturbances (CRDs affect as many as a quarter of Alzheimer's disease (AD patients during some stage of their illness. Alterations in the suprachiasmatic nucleus and melatonin secretion are the major factors linked with the cause of CRDs. As a result, the normal physiology of sleep, the biological clock, and core body temperature are affected. This paper systematically discusses some of the causative factors, typical symptoms, and treatment options for CRDs in patients with AD. This paper also emphasizes the implementation of behavioral and environmental therapies before embarking on medications to treat CRDs. Pharmacotherapeutic options are summarized to provide symptomatic benefits for the patient and relieve stress on their families and professional care providers. As of today, there are few studies relative to CRDs in AD. Large randomized trials are warranted to evaluate the effects of treatments such as bright light therapy and engaging activities in the reduction of CRDs in AD patients.

  15. A survey on temperature-aware routing protocols in wireless body sensor networks.

    Science.gov (United States)

    Oey, Christian Henry Wijaya; Moh, Sangman

    2013-08-02

    The rapid growth of the elderly population in the world and the rising cost of healthcare impose big issues for healthcare and medical monitoring. A Wireless Body Sensor Network (WBSN) is comprised of small sensor nodes attached inside, on or around a human body, the main purpose of which is to monitor the functions and surroundings of the human body. However, the heat generated by the node's circuitry and antenna could cause damage to the human tissue. Therefore, in designing a routing protocol for WBSNs, it is important to reduce the heat by incorporating temperature into the routing metric. The main contribution of this paper is to survey existing temperature-aware routing protocols that have been proposed for WBSNs. In this paper, we present a brief overview of WBSNs, review the existing routing protocols comparatively and discuss challenging open issues in the design of routing protocols.

  16. A Survey on Temperature-Aware Routing Protocols in Wireless Body Sensor Networks

    Directory of Open Access Journals (Sweden)

    Sangman Moh

    2013-08-01

    Full Text Available The rapid growth of the elderly population in the world and the rising cost of healthcare impose big issues for healthcare and medical monitoring. A Wireless Body Sensor Network (WBSN is comprised of small sensor nodes attached inside, on or around a human body, the main purpose of which is to monitor the functions and surroundings of the human body. However, the heat generated by the node’s circuitry and antenna could cause damage to the human tissue. Therefore, in designing a routing protocol for WBSNs, it is important to reduce the heat by incorporating temperature into the routing metric. The main contribution of this paper is to survey existing temperature-aware routing protocols that have been proposed for WBSNs. In this paper, we present a brief overview of WBSNs, review the existing routing protocols comparatively and discuss challenging open issues in the design of routing protocols.

  17. Performance, Body Temperature and Egg Quality of Laying Hens Fed Vitamins D and C Under Three Environmental Temperatures

    Directory of Open Access Journals (Sweden)

    Faria DE

    2001-01-01

    Full Text Available Three experiments were conducted in a climatic chamber to determine the effects of vitamins D3 and C supplementation on performance, body temperature, and egg quality under thermoneutral temperature (24.8º to 27.0º C, a cyclic heat stress (26.2º C for 16 h and 32.1º C for 8 h and a constant heat stress (30.0º to 32.0º C for three weeks in each temperature. One hundred forty-four White Leghorn hens aged 31 weeks were used in a completely randomized design with a factorial arrangement of 3 x 3: vitamin D3 (2,500, 3,000, and 3,500 IU/kg and vitamin C (0, 200, and 400 ppm, with a total of nine treatments with four replicates of four hens each. Parameters measured included feed intake (FI, feed:gain (FG, egg production (EP, egg weight (EW, egg mass (EM, rectal (RT and dorsal temperatures (DT, percentages of albumen (AP and yolk (YP, Haugh units (HU, yolk index (YI, shell percent (SP, shell thickness (ST and egg specific gravity (ESG. Vitamin D3 influenced the parameters SP, ST, ESG and DT; vitamin C influenced YI, SP and ESG. There was no influence of environmental temperature only on HU. It was concluded that higher levels of vitamin D3 and 200 or 400 ppm of vitamin C can be improve eggshell quality and that heat stress impaired the main characteristics evaluated.

  18. Water temperature, body mass and fasting heat production of pacu (Piaractus mesopotamicus

    Directory of Open Access Journals (Sweden)

    FREDY A.A. AGUILAR

    Full Text Available ABSTRACT Knowledge on fasting heat production (HEf of fish is key to develop bioenergetics models thus improving feeding management of farmed species. The core of knowledge on HEf of farmed, neotropical fish is scarce. This study assessed the effect of body mass and water temperature on standard metabolism and fasting heat production of pacu, Piaractus mesopotamicus, an omnivore, Neotropical fresh water characin important for farming and fisheries industries all through South American continent. An automated, intermittent flow respirometry system was used to measure standard metabolic rate (SMR of pacu (17 - 1,050 g at five water temperatures: 19, 23, 26, 29 and 33 °C. Mass specific SMR increased with increasing water temperature but decreased as function of body mass. The allometric exponent for scaling HEf was 0.788, and lied in the range recorded for all studied warm-water fish. The recorded van't Hoff factor (Q10 for pacu (2.06 shows the species low response to temperature increases. The model HEf = 0.04643×W0.7882×T1.837 allows to predict HEf (kJ d-1 from body mass (W, kg and water temperature (T, °C, and can be used in bioenergetical models for the species.

  19. Assessing the reliability of thermography to infer internal body temperatures of lizards.

    Science.gov (United States)

    Barroso, Frederico M; Carretero, Miguel A; Silva, Francisco; Sannolo, Marco

    2016-12-01

    For many years lizard thermal ecology studies have relied on the use of contact thermometry to obtain internal body temperature (T b ) of the animals. However, with progressing technology, an interest grew in using new, less invasive methods, such as InfraRed (IR) pyrometry and thermography, to infer T b of reptiles. Nonetheless few studies have tested the reliability of these new tools. The present study tested the use of IR cameras as a non-invasive tool to infer T b of lizards, using three differently body-sized lacertid species (Podarcis virescens, Lacerta schreiberi and Timon lepidus). Given the occurrence of regional heterothermy, we pairwise compared thermography readings of six body parts (snout, eye, head, dorsal, hind limb, tail base) to cloacal temperature (measured by a thermometer-associated thermocouple probe) commonly employed to measure T b in field and lab studies. The results showed moderate to strong correlations (R 2 =0.84-0.99) between all body parts and cloacal temperature. However, despite the readings on the tail base showed the strongest correlation in all three species, it was the eye where the absolute values and pattern of temperature change most consistently followed the cloacal measurements. Hence, we concluded that the eye would be the body location whose IR camera readings more closely approximate that of the animal's internal environment. Alternatively, other body parts can be used, provided that a careful calibration is carried out. We provide guidelines for future research using thermography to infer Tb of lizards. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Are the surface areas of the gills and body involved with changing metabolic scaling with temperature?

    Science.gov (United States)

    Li, Ge; Lv, Xiao; Zhou, Jing; Shen, Cong; Xia, Danyang; Xie, Hang; Luo, Yiping

    2018-03-20

    The metabolic-level boundaries (MLB) hypothesis proposes that metabolic level mediates the relative influence of surface area (SA) vs volume related metabolic processes on the body-mass scaling of metabolic rate in organisms. The variation in the scaling of SA may affect how metabolic level affects the metabolic scaling exponent. This study aimed to determine the influence of increasing metabolic level at a higher temperature on the metabolic scaling exponent of the crucian carp and determine the link between metabolic scaling exponents and SA parameters of both gills and body. The SA of gills and body and the resting metabolic rate (RMR) of the crucian carp were assessed at 15 o C and 25 o C, and their mass scaling exponents were analyzed. The results showed a significantly higher RMR, with a lower scaling exponent, in the crucian carp at a higher temperature. The gills SA and the total SA of the fish (TSA) are reduced with the increasing temperature. The b RMR tends to be close to that of the TSA at a higher temperature. This suggests that temperature positively affects metabolic level but negatively affects the scaling exponent of RMR ( b RMR ). The findings support the MLB hypothesis. The lower scaling exponent at a higher temperature can be alternatively explained as that the higher viscosity of cold water impedes respiratory ventilation and oxygen uptake and reduces MR more in smaller individuals than in larger individuals at lower temperature, thus resulting in a negative association between temperature and b RMR . © 2018. Published by The Company of Biologists Ltd.

  1. In Search of Circasemidian Rhythms

    National Research Council Canada - National Science Library

    Miller, James C

    2006-01-01

    .... To help us quantify the effects of fatigue, we hypothesized that body temperature, subjective sleepiness, simple response time and working memory speed would oscillate with a period of 12 hours...

  2. Temporal thermometry fails to track body core temperature during heat stress.

    Science.gov (United States)

    Low, David A; Vu, Albert; Brown, Marilee; Davis, Scott L; Keller, David M; Levine, Benjamin D; Crandall, Craig G

    2007-07-01

    The aim of this study was to assess the accuracy of temporal scanning thermometry in monitoring internal temperature increases during passive heating. Sixteen subjects (5 males and 11 females) underwent a whole-body passive heat stress (water-perfused suit) to increase internal temperature. Temperatures were obtained with a temporal scanner and with an ingestible-pill telemetry system that tracks intestinal temperature. Temperatures were recorded while subjects were normothermic (34 degrees C water-perfusing suit) and every 10 min during passive heating (48 degrees C water-perfusing suit). Heart rate (ECG), mean skin temperature (weighted six-site average), skin blood flow (laser Doppler flowmetry), and sweat rate (capacitance hygrometry) were all significantly elevated at the end of heating (all P heat stress temporal-derived temperature was not different from intestinal temperature (36.98 +/- 0.09 vs 37.01 +/- 0.09 degrees C, respectively, P = 0.76). However, after 30 min of heating (the greatest duration of heating completed by all subjects), temporal-derived temperature decreased to below the pre-heat stress baseline (-0.22 +/- 0.11), whereas intestinal temperature increased by 0.39 +/- 0.07 degrees C (P heating (N = 11), intestinal-derived internal temperature increased by 0.70 +/- 0.09 degrees C, whereas temporal-derived temperature decreased by 0.29 +/- 0.10 degrees C (P heating. Given these findings, it is recommended that this technique not be used to assess temperature in hyperthermic diaphoretic subjects.

  3. IMPACT OF THE LOCATION OF THE DAIRY COWS IN THE BARN ON THEIR BODY SURFACE TEMPERATURE

    Directory of Open Access Journals (Sweden)

    Martin Slachta

    2013-09-01

    Full Text Available The objective of the study was to determine skin surface temperature of dairy cows housed in tie stalls, according to their location in the barn. A total of 52 healthy cows were investigated, 31 of which were kept in cold stalls by the entrance to the barn and 21 in warm stalls located in the centre of the barn. Skin surface temperature was measured in 8 different body parts using a non-contact thermometer Fluke 572 pyrometer. The results showed that skin temperature of the cows varied according to their location. It was significantly lower in the cows housed in cold stalls compared to those kept in warm stalls P lt; 0.05. The difference was particularly evident for the udder, reaching 1.1C P lt, 0.01. Skin temperature of the cows varied between different measurement points. In both cold and warm stalls, skin temperature was highest on the udder and lowest at the hock joint P lt, 0.01. Time of day and air temperature outside the barn had a highly significant effect on the skin temperature of the cows. The lower the air temperature was, the lower was the skin temperature at all points of measurement P lt, 0.01. It was found that the skin surface of housed cows subjected to increased air movement is at a greater risk of becoming hypothermic.

  4. Work related injuries; impact of circadian rhythm

    Directory of Open Access Journals (Sweden)

    Mostafa Hosseini

    2017-04-01

    Full Text Available Work related injuries make up a major part of traumatic injuries, which inflict a financial burden and huge costs on the family and society. Work related injuries result in loss of a work force of a country on one hand and cause the family to lose its financial support on the other. Therefore, this type of injury has attracted much attention. Although numerous variables play a role in occurrence of these accidents, the effect of physiologic factors cannot be overlooked in this regard. For example interference of night working shifts with the natural circadian rhythm of the body is among these factors. Age, decreased physical strength, tiredness and extent of light are among other factors that affect the level of consciousness in an individual and may lead to work related traumas. In recent years, the role of circadian rhythm in occurrence of work related traumas has been widely considered. Circadian rhythm is formed as a result of a number of clock genes in suprachiasmatic nucleus and other organs of the body. Circadian rhythm is associated with significant changes in hormone secretion and level of consciousness in an individual. Rhythms desynchrony is a phenomenon seen in those that work during the night and sleep during the day and is accompanied by increased risk of work related accidents. For example in a systematic review assessing 13 studies, it was revealed that working night shifts is associated with increased risk of work related accidents. However, there is still controversy regarding the net effect of night shifts in incidence of work related accidents. One question that has not been answered yet is that if an individual works night shifts for a long time, is their circadian rhythm affected or not? On the other hand, can using strategies that improve level of consciousness (such as using blue light in the work place decrease the incidence of these accidents? Are changes in sleep and wake conditions alone able to alter the expression

  5. Telemetric Evaluation of Body Temperature and Physical Activity as Predictors of Mortality in a Murine Model of Staphylococcal Enterotoxic Shock

    National Research Council Canada - National Science Library

    Vlach, Kim

    2000-01-01

    .... This study determined whether body temperature and physical activity, monitored telemetrically, could predict impending death and provide an earlier, more humane experimental endpoint. Methods...

  6. [Affective disorders and biological rhythms].

    Science.gov (United States)

    Le Strat, Y; Ramoz, N; Gorwood, P

    2008-06-01

    Disruptions of circadian rhythms are described in affective disorders, including unipolar and bipolar disorder, but also seasonal affective disorder. Sleep-wake and hormone circadian rhythms are among the most quoted examples. Depression could be conceptualized as a desynchronization between the endogenous circadian pacemaker and the exogenous stimuli, such as sunlight and social rhythms. Accordingly, Clock genes have been studied and the literature suggests that variants in these genes confer a higher risk of relapse, more sleep disturbances associated with depression, as well as incomplete treatment response. Most of therapeutic interventions in depression have an impact on biological rhythms. Some of them exclusively act via a biological pathway, such as sleep deprivation or light therapy. Some psychosocial interventions are specifically focusing on social rhythms, particularly in bipolar disorder, in which the promotion of stabilization is emphasized. Finally, all antidepressant medications could improve biological rhythms, but some new agents are now totally focusing this novel approach for the treatment of depression.

  7. No Relation between Body Temperature and Arterial Recanalization at Three Days in Patients with Acute Ischaemic Stroke

    NARCIS (Netherlands)

    Geurts, Marjolein; van der Worp, HB; Horsch, Alexander D.; Kappelle, L. Jaap; Biessels, Geert J.; Velthuis, BK

    2015-01-01

    Background Recanalization of an occluded intracranial artery is influenced by temperature-dependent enzymes, including alteplase. We assessed the relation between body temperature on admission and recanalization. Methods We included 278 patients with acute ischaemic stroke within nine hours after

  8. No relation between body temperature and arterial recanalization at three days in patients with acute ischaemic stroke

    NARCIS (Netherlands)

    M. Geurts (Marjolein); H.B. Van Der Worp (H. Bart); A.D. Horsch (Alexander D.); L.J. Kappelle (Jaap); G.J. Biessels (Geert Jan); B.K. Velthuis (Birgitta); C.B. Majoie (Charles); Y.B.W.E.M. Roos; L.E.M. Duijm (Lucien); K. Keizer (Koos); A. van der Lugt (Aad); D.W.J. Dippel (Diederik); K.E. Droogh-De Greve; H.P. Bienfait (Henri); M.A.A. van Walderveen (Marianne); M.J.H. Wermer (Marieke); G.J. Lycklama à Nijeholt (Geert); J. Boiten (Jelis); A. Duyndam (Anita); V.I.H. Kwa; F.J. Meijer (F.); E.J. van Dijk (Ewoud); A.M. Kesselring (Anouk); J. Hofmeijer; J.A. Vos (Jan Albert); W.J. Schonewille (Wouter); W.J. van Rooij (W.); P.L.M. de Kort (Paul); C.C. Pleiter (C.); S.L.M. Bakker (Stef); J. Bot (Joseph); M.C. Visser (Marieke); I.C. van der Schaaf (Irene); J.W. Dankbaar (Jan); W.P. Mali (Willem); T. van Seeters (Tom); A.D. Horsch (Alexander D.); J.M. Niesten (Joris); G.J. Biessels; L.J. Kappelle; J.S.K. Luitse; Y. van der Graaf (Yolanda)

    2015-01-01

    textabstractBackground: Recanalization of an occluded intracranial artery is influenced by temperature-dependent enzymes, including alteplase. We assessed the relation between body temperature on admission and recanalization. Methods: We included 278 patients with acute ischaemic stroke within nine

  9. Exoskeleton may influence the internal body temperatures of Neotropical dung beetles (Col. Scarabaeinae

    Directory of Open Access Journals (Sweden)

    Valentina Amore

    2017-05-01

    Full Text Available The insect exoskeleton is a multifunctional coat with a continuum of mechanical and structural properties constituting the barrier between electromagnetic waves and the internal body parts. This paper examines the ability of beetle exoskeleton to regulate internal body temperature considering its thermal permeability or isolation to simulated solar irradiance and infrared radiation. Seven Neotropical species of dung beetles (Coleoptera, Scarabaeinae differing in colour, surface sculptures, size, sexual dimorphism, period of activity, guild category and altitudinal distribution were studied. Specimens were repeatedly subjected to heating trials under simulated solar irradiance and infrared radiation using a halogen neodymium bulb light with a balanced daylight spectrum and a ceramic infrared heat emitter. The volume of exoskeleton and its weight per volume unit were significantly more important for the heating rate at the beginning of the heating process than for the asymptotic maximum temperature reached at the end of the trials: larger beetles with relatively thicker exoskeletons heated more slowly. The source of radiation greatly influences the asymptotic temperature reached, but has a negligible effect in determining the rate of heat gain by beetles: they reached higher temperatures under artificial sunlight than under infrared radiation. Interspecific differences were negligible in the heating rate but had a large magnitude effect on the asymptotic temperature, only detectable under simulated sun irradiance. The fact that sun irradiance is differentially absorbed dorsally and transformed into heat among species opens the possibility that differences in dorsal exoskeleton would facilitate the heat gain under restrictive environmental temperatures below the preferred ones. The findings provided by this study support the important role played by the exoskeleton in the heating process of beetles, a cuticle able to act passively in the thermal

  10. Mitigation of Temperature Induced Single Event Crosstalk Noise by Applying Adaptive Forward Body Bias

    Science.gov (United States)

    Bhowmik, Pankaj

    Soft Errors due to Single Event (SE) Transients is one of the important reliability issues, which is becoming very prominent in advanced technology and in space applications. Increasing coupling effects among interconnects, on the other hand, can cause SE Transients to contaminate electronically unrelated circuit paths, which in turn can increase circuit sensitivity to radiation. Coupling capacitance increases due to reducing distances between interconnect lines making crosstalk noise more important. On the other hand, chips now experience higher temperatures due to environmental factors and high performance of chips. High-performance VLSI circuits consume more power and hence experience higher temperature due to high utilization factor. The increased temperature affects both interconnect resistance and driving strength of interconnect buffers. This work shows that thermal effects increase the amount of crosstalk noise observed on the victim line at nominal supply voltages. With thermally induced crosstalk contribution, total crosstalk noise may exceed the noise margin of the subsequent gate causing a wrong value to be propagated. The crosstalk prevention measures taken such as victim driver sizing may not be sufficient if thermal effects are not properly considered. This work aims to provide a mitigation method for thermally induced crosstalk noise using adaptive forward body bias. At high temperature, drain current reduces, and adaptive body biasing makes the CMOS recover the lost the drain current. A temperature sensor is proposed here to generate a necessary voltage at the CMOS body. A good temperature sensitivity is achieved with the tiny sensors that keep constant driving strength. Interconnect is modeled in using 10-pi modeling and 45nm technology was use for this simulation. Our proposed method mitigates 90% of temperature induced crosstalk contribution.

  11. Exoskeleton may influence the internal body temperatures of Neotropical dung beetles (Col. Scarabaeinae).

    Science.gov (United States)

    Amore, Valentina; Hernández, Malva I M; Carrascal, Luis M; Lobo, Jorge M

    2017-01-01

    The insect exoskeleton is a multifunctional coat with a continuum of mechanical and structural properties constituting the barrier between electromagnetic waves and the internal body parts. This paper examines the ability of beetle exoskeleton to regulate internal body temperature considering its thermal permeability or isolation to simulated solar irradiance and infrared radiation. Seven Neotropical species of dung beetles (Coleoptera, Scarabaeinae) differing in colour, surface sculptures, size, sexual dimorphism, period of activity, guild category and altitudinal distribution were studied. Specimens were repeatedly subjected to heating trials under simulated solar irradiance and infrared radiation using a halogen neodymium bulb light with a balanced daylight spectrum and a ceramic infrared heat emitter. The volume of exoskeleton and its weight per volume unit were significantly more important for the heating rate at the beginning of the heating process than for the asymptotic maximum temperature reached at the end of the trials: larger beetles with relatively thicker exoskeletons heated more slowly. The source of radiation greatly influences the asymptotic temperature reached, but has a negligible effect in determining the rate of heat gain by beetles: they reached higher temperatures under artificial sunlight than under infrared radiation. Interspecific differences were negligible in the heating rate but had a large magnitude effect on the asymptotic temperature, only detectable under simulated sun irradiance. The fact that sun irradiance is differentially absorbed dorsally and transformed into heat among species opens the possibility that differences in dorsal exoskeleton would facilitate the heat gain under restrictive environmental temperatures below the preferred ones. The findings provided by this study support the important role played by the exoskeleton in the heating process of beetles, a cuticle able to act passively in the thermal control of body

  12. Heat balance model for a human body in the form of wet bulb globe temperature indices.

    Science.gov (United States)

    Sakoi, Tomonori; Mochida, Tohru; Kurazumi, Yoshihito; Kuwabara, Kohei; Horiba, Yosuke; Sawada, Shin-Ichi

    2018-01-01

    The purpose of this study is to expand the empirically derived wet bulb globe temperature (WBGT) index to a rational thermal index based on the heat balance for a human body. We derive the heat balance model in the same form as the WBGT for a human engaged in moderate intensity work with a metabolic heat production of 174W/m 2 while wearing typical vapor-permeable clothing under shady and sunny conditions. Two important relationships are revealed based on this derivation: (1) the natural wet bulb and black globe temperature coefficients in the WBGT coincide with the heat balance equation for a human body with a fixed skin wettedness of approximately 0.45 at a fixed skin temperature; and (2) the WBGT can be interpreted as the environmental potential to increase skin temperature rather than the heat storage rate of a human body. We propose an adjustment factor calculation method that supports the application of WBGT for humans dressed in various clothing types and working under various air velocity conditions. Concurrently, we note difficulties in adjusting the WBGT by using a single factor for humans wearing vapor-impermeable protective clothing. The WBGT for shady conditions does not need adjustment depending on the positive radiant field (i.e., when a radiant heat source exists), whereas that for the sunny condition requires adjustments because it underestimates heat stress, which may result in insufficient human protection measures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. The Effects of Increased Body Temperature on Motor Control during Golf Putting.

    Science.gov (United States)

    Mathers, John F; Grealy, Madeleine A

    2016-01-01

    This study investigated the effect of increased core temperature on the performance outcome and movement kinematics of elite golfers during a golf putting task. The study aimed to examine individual differences in the extent to which increased temperature influenced the rate of putting success, whether increased temperature speeded up the timing of the putting downswing and whether elite golfers changed their movement kinematics during times of thermal stress. Six participants performed 20 putts to each of four putt distances (1, 2, 3, and 4 m) under normal temperature conditions and when core body temperature was increased. There was no significant difference in the number of successful putts between the two temperature conditions, but there was an increase in putterhead velocity at ball impact on successful putts to distances of 1 and 4 m when temperature was elevated. This reflected an increase in swing amplitude rather than a reduction in swing duration as hypothesized. There were individual differences in the motor control response to thermal stress as three of the golfers changed the kinematic parameters used to scale their putting movements to achieve putts of different distances at elevated temperatures. Theoretical implications for these findings and the practical implications for elite golfers and future research are discussed.

  14. Short communication: Changes in body temperature of calves up to 2 months of age as affected by time of day, age, and ambient temperature.

    Science.gov (United States)

    Hill, T M; Bateman, H G; Suarez-Mena, F X; Dennis, T S; Schlotterbeck, R L

    2016-11-01

    Extensive measurements of calf body temperature are limited in the literature. In this study, body temperatures were collected by taping a data logger to the skin over the tail vein opposing the rectum of Holstein calves between 4 and 60d of age during 3 different periods of the summer and fall. The summer period was separated into moderate (21-33°C average low to high) and hot (25-37°C) periods, whereas the fall exhibited cool (11-19°C) ambient temperatures. Tail temperatures were compared in a mixed model ANOVA using ambient temperature, age of calf, and time of day (10-min increments) as fixed effects and calf as a random effect. Measures within calf were modeled as repeated effects of type autoregressive 1. Calf temperature increased 0.0325°C (±0.00035) per 1°C increase in ambient temperature. Body temperature varied in a distinct, diurnal pattern with time of day, with body temperatures being lowest around 0800h and highest between 1700 and 2200h. During periods of hot weather, the highest calf temperature was later in the day (~2200h). Calf minimum, maximum, and average body temperatures were all higher in hot than in moderate periods and higher in moderate than in cool periods. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  15. The Inability to Screen Exhibition Swine for Influenza A Virus Using Body Temperature.

    Science.gov (United States)

    Bowman, A S; Nolting, J M; Workman, J D; Cooper, M; Fisher, A E; Marsh, B; Forshey, T

    2016-02-01

    Agricultural fairs create an unconventional animal-human interface that has been associated with swine-to-human transmission of influenza A virus (IAV) in recent years. Early detection of IAV-infected pigs at agricultural fairs would allow veterinarians to better protect swine and human health during these swine exhibitions. This study assessed the use of swine body temperature measurement, recorded by infrared and rectal thermometers, as a practical method to detect IAV-infected swine at agricultural fairs. In our first objective, infrared thermometers were used to record the body surface temperature of 1,092 pigs at the time of IAV nasal swab collection at the end of the exhibition period of 55 agricultural fairs. IAV was recovered from 212 (19.4%) pigs, and the difference in mean infrared body temperature measurement of IAV-positive and IAV-negative pigs was 0.83°C. In a second objective, snout wipes were collected from 1,948 pigs immediately prior to the unloading of the animals at a single large swine exhibition. Concurrent to the snout wipe collection, owners took the rectal temperatures of his/her pigs. In this case, 47 (2.4%) pigs tested positive for IAV before they entered the swine barn. The mean rectal temperatures differed by only 0.19°C between IAV-positive and IAV-negative pigs. The low prevalence of IAV among the pigs upon entry to the fair in the second objective provides evidence that limiting intraspecies spread of IAV during the fairs will likely have significant impacts on the zoonotic transmission. However, in both objectives, the high degree of similarity in the body temperature measurements between the IAV-positive and IAV-negative pigs made it impossible to set a diagnostically meaningful cut point to differentiate IAV status of the individual animals. Unfortunately, body temperature measurement cannot be used to accurately screen exhibition swine for IAV. © 2015 Blackwell Verlag GmbH.

  16. Temporal and spatial dispersion of human body temperature during deep hypothermia.

    Science.gov (United States)

    Opatz, O; Trippel, T; Lochner, A; Werner, A; Stahn, A; Steinach, M; Lenk, J; Kuppe, H; Gunga, H C

    2013-11-01

    Clinical temperature management remains challenging. Choosing the right sensor location to determine the core body temperature is a particular matter of academic and clinical debate. This study aimed to investigate the relationship of measured temperatures at different sites during surgery in deep hypothermic patients. In this prospective single-centre study, we studied 24 patients undergoing cardiothoracic surgery: 12 in normothermia, 3 in mild, and 9 in deep hypothermia. Temperature recordings of a non-invasive heat flux sensor at the forehead were compared with the arterial outlet temperature of a heart-lung machine, with the temperature on a conventional vesical bladder thermistor and, for patients undergoing deep hypothermia, with oesophageal temperature. Using a linear model for sensor comparison, the arterial outlet sensor showed a difference among the other sensor positions between -0.54 and -1.12°C. The 95% confidence interval ranged between 7.06 and 8.82°C for the upper limit and -8.14 and -10.62°C for the lower limit. Because of the hysteretic shape, the curves were divided into phases and fitted into a non-linear model according to time and placement of the sensors. During cooling and warming phases, a quadratic relationship could be observed among arterial, oesophageal, vesical, and cranial temperature recordings, with coefficients of determination ranging between 0.95 and 0.98 (standard errors of the estimate 0.69-1.12°C). We suggest that measured surrogate temperatures as indices of the cerebral temperature (e.g. vesical bladder temperature) should be interpreted with respect to the temporal and spatial dispersion during cooling and rewarming phases.

  17. Computational model for calculating body-core temperature elevation in rabbits due to whole-body exposure at 2.45 GHz

    Science.gov (United States)

    Hirata, Akimasa; Sugiyama, Hironori; Kojima, Masami; Kawai, Hiroki; Yamashiro, Yoko; Fujiwara, Osamu; Watanabe, Soichi; Sasaki, Kazuyuki

    2008-06-01

    In the current international guidelines and standards with regard to human exposure to electromagnetic waves, the basic restriction is defined in terms of the whole-body average-specific absorption rate. The rationale for the guidelines is that the characteristic pattern of thermoregulatory response is observed for the whole-body average SAR above a certain level. However, the relationship between energy absorption and temperature elevation was not well quantified. In this study, we improved our thermal computation model for rabbits, which was developed for localized exposure on eye, in order to investigate the body-core temperature elevation due to whole-body exposure at 2.45 GHz. The effect of anesthesia on the body-core temperature elevation was also discussed in comparison with measured results. For the whole-body average SAR of 3.0 W kg-1, the body-core temperature in rabbits elevates with time, without becoming saturated. The administration of anesthesia suppressed body-core temperature elevation, which is attributed to the reduced basal metabolic rate.

  18. Temporal profile of body temperature in acute ischemic stroke: relation to stroke severity and outcome

    Science.gov (United States)

    2012-01-01

    Background Pyrexia after stroke (temperature ≥37.5°C) is associated with poor prognosis, but information on timing of body temperature changes and relationship to stroke severity and subtypes varies. Methods We recruited patients with acute ischemic stroke, measured stroke severity, stroke subtype and recorded four-hourly tympanic (body) temperature readings from admission to 120 hours after stroke. We sought causes of pyrexia and measured functional outcome at 90 days. We systematically summarised all relevant previous studies. Results Amongst 44 patients (21 males, mean age 72 years SD 11) with median National Institute of Health Stroke Score (NIHSS) 7 (range 0–28), 14 had total anterior circulation strokes (TACS). On admission all patients, both TACS and non-TACS, were normothermic (median 36.3°C vs 36.5°C, p=0.382 respectively) at median 4 hours (interquartile range, IQR, 2–8) after stroke; admission temperature and NIHSS were not associated (r2=0.0, p=0.353). Peak temperature, occurring at 35.5 (IQR 19.0 to 53.8) hours after stroke, was higher in TACS (37.7°C) than non-TACS (37.1°C, ptemperatures. Sixteen (36%) patients became pyrexial, in seven (44%) of whom we found no cause other than the stroke. Conclusions Normothermia is usual within the first 4 hours of stroke. Peak temperature occurs at 1.5 to 2 days after stroke, and is related to stroke severity/subtype and more closely associated with poor outcome than admission temperature. Temperature-outcome associations after stroke are complex, but normothermia on admission should not preclude randomisation of patients into trials of therapeutic hypothermia. PMID:23075282

  19. Light Rhythms in Architecture

    DEFF Research Database (Denmark)

    Bülow, Katja

    2013-01-01

    On one hand, urban lighting expresses itself in a complex visual environment made by the interplay by between many separate lighting schemes, as street lighting, shop lighting, luminous commercials etc. On the other, a noticeable order of patterns occurs, when lighting is observed as luminous...... formation and rhythm. When integrated into an architectural concept, electrical lighting non-intended for poetic composition has the ability to contribute to place, time, and function-telling aspects of places in urban contexts. Urban environments are information wise challenging to pre-historic human...... instincts, but they can be met by careful selection and adjustment of existing light situations....

  20. A Causal Rhythm Grouping

    DEFF Research Database (Denmark)

    Jensen, Karl Kristoffer

    2005-01-01

    This paper presents a method to identify segment boundaries in music. The method is based on a multi-step model; first a features is measured from the audio, then a measure of rhythm is calculated from the feature, the diagonal of a self-similarity matrix is calculated, and finally the segment...... boundaries are found on a smoothed novelty measure, calculated from the self-similarity matrix. All the steps of the model have been accompanied with an informal evaluation, and the final system is tested on a variety of rhythmic songs with good results. The paper introduces a new feature that is shown...

  1. Light Rhythms in Architecture

    DEFF Research Database (Denmark)

    Bülow, Katja

    2013-01-01

    formation and rhythm. When integrated into an architectural concept, electrical lighting non-intended for poetic composition has the ability to contribute to place, time, and function-telling aspects of places in urban contexts. Urban environments are information wise challenging to pre-historic human......On one hand, urban lighting expresses itself in a complex visual environment made by the interplay by between many separate lighting schemes, as street lighting, shop lighting, luminous commercials etc. On the other, a noticeable order of patterns occurs, when lighting is observed as luminous...... instincts, but they can be met by careful selection and adjustment of existing light situations....

  2. Amplitude reduction and phase shifts of melatonin, cortisol and other circadian rhythms after a gradual advance of sleep and light exposure in humans.

    Science.gov (United States)

    Dijk, Derk-Jan; Duffy, Jeanne F; Silva, Edward J; Shanahan, Theresa L; Boivin, Diane B; Czeisler, Charles A

    2012-01-01

    The phase and amplitude of rhythms in physiology and behavior are generated by circadian oscillators and entrained to the 24-h day by exposure to the light-dark cycle and feedback from the sleep-wake cycle. The extent to which the phase and amplitude of multiple rhythms are similarly affected during altered timing of light exposure and the sleep-wake cycle has not been fully characterized. We assessed the phase and amplitude of the rhythms of melatonin, core body temperature, cortisol, alertness, performance and sleep after a perturbation of entrainment by a gradual advance of the sleep-wake schedule (10 h in 5 days) and associated light-dark cycle in 14 healthy men. The light-dark cycle consisted either of moderate intensity 'room' light (∼90-150 lux) or moderate light supplemented with bright light (∼10,000 lux) for 5 to 8 hours following sleep. After the advance of the sleep-wake schedule in moderate light, no significant advance of the melatonin rhythm was observed whereas, after bright light supplementation the phase advance was 8.1 h (SEM 0.7 h). Individual differences in phase shifts correlated across variables. The amplitude of the melatonin rhythm assessed under constant conditions was reduced after moderate light by 54% (17-94%) and after bright light by 52% (range 12-84%), as compared to the amplitude at baseline in the presence of a sleep-wake cycle. Individual differences in amplitude reduction of the melatonin rhythm correlated with the amplitude of body temperature, cortisol and alertness. Alterations in the timing of the sleep-wake cycle and associated bright or moderate light exposure can lead to changes in phase and reduction of circadian amplitude which are consistent across multiple variables but differ between individuals. These data have implications for our understanding of circadian organization and the negative health outcomes associated with shift-work, jet-lag and exposure to artificial light.

  3. Technical note: Assessment of an alternative technique for measuring body temperature in pigs.

    Science.gov (United States)

    Petry, A; McGilvray, W; Rakhshandeh, A R; Rakhshandeh, A

    2017-07-01

    Core body temperature (CBT) is one of the main vital signs that is used to evaluate the health status of pigs. The most common and feasible method for assessing CBT in pigs is rectal temperature (RT). Obtaining RT is stressful for animals, may generate inaccurate results, and has the risk of spreading disease. Infrared imaging (IR) thermography of the body of pigs may be a safer and less stressful alternative to RT. The objective of the current study was to evaluate the efficacy of using IR as an alternative for monitoring CBT in pigs. Twenty-three gilts (30.5 ± 5.62 kg BW) were housed in metabolism crates in an environmentally controlled facility and fed an 860 g/d grower diet. After 4 d of adaptation, the febrile response was induced by intramuscular injection of lipopolysaccharide (LPS; 25 µg/kg BW). Each pig's body temperature was recorded at 0, 2, 4, 6, 8, 10, and 24 h after LPS challenge using the following 3 methods: 1) RT, 2) IR of the eye and ear, and 3) CBT using an orally administered digital temperature sensor. Statistical analysis was performed in a completely randomized design in SAS using Mixed, Correlation, and Regression procedures. Relative to time 0 h, LPS increased the eye temperature, CBT, and RT by 0.92, 1.32, and 1.48°C, respectively ( temperature. Eye temperature, RT, and CBT, but not ear temperature, were highly correlated ( ≥ 0.96) during the course of the study ( temperature were -28.2 ± 8.70 and 1.76 ± 0.221, respectively, and for RT were -24.5 ± 7.69 and 1.65 ± 0.196, respectively ( ≥ 0.96; 95% confidence interval). Collectively, these results indicated a strong relationship between eye temperature, RT, and CBT in pigs. Therefore, IR of the eye can be used as a precise, noncontact alternative to RT measurements for monitoring CBT in swine.

  4. Analysis of Long-Term Temperature Variations in the Human Body.

    Science.gov (United States)

    Dakappa, Pradeepa Hoskeri; Mahabala, Chakrapani

    2015-01-01

    Body temperature is a continuous physiological variable. In normal healthy adults, oral temperature is estimated to vary between 36.1°C and 37.2°C. Fever is a complex host response to many external and internal agents and is a potential contributor to many clinical conditions. Despite being one of the foremost vital signs, temperature and its analysis and variations during many pathological conditions has yet to be examined in detail using mathematical techniques. Classical fever patterns based on recordings obtained every 8-12 h have been developed. However, such patterns do not provide meaningful information in diagnosing diseases. Because fever is a host response, it is likely that there could be a unique response to specific etiologies. Continuous long-term temperature monitoring and pattern analysis using specific analytical methods developed in engineering and physics could aid in revealing unique fever responses of hosts and in different clinical conditions. Furthermore, such analysis can potentially be used as a novel diagnostic tool and to study the effect of pharmaceutical agents and other therapeutic protocols. Thus, the goal of our article is to present a comprehensive review of the recent relevant literature and analyze the current state of research regarding temperature variations in the human body.

  5. Effects of alpha-glucosylhesperidin on the peripheral body temperature and autonomic nervous system.

    Science.gov (United States)

    Takumi, Hiroko; Fujishima, Noboru; Shiraishi, Koso; Mori, Yuka; Ariyama, Ai; Kometani, Takashi; Hashimoto, Shinichi; Nadamoto, Tomonori

    2010-01-01

    We studied the effects of alpha-glucosylhesperidin (G-Hsp) on the peripheral body temperature and autonomic nervous system in humans. We first conducted a survey of 97 female university students about excessive sensitivity to the cold; 74% of them replied that they were susceptible or somewhat susceptible to the cold. We subsequently conducted a three-step experiment. In the first experiment, G-Hsp (500 mg) was proven to prevent a decrease in the peripheral body temperature under an ambient temperature of 24 degrees C. In the second experiment, a warm beverage containing G-Hsp promoted blood circulation and kept the finger temperature higher for a longer time. We finally used a heart-rate variability analysis to study whether G-Hsp changed the autonomic nervous activity. The high-frequency (HF) component tended to be higher, while the ratio of the low-frequency (LF)/HF components tended to be lower after the G-Hsp administration. These results suggest that the mechanism for temperature control by G-Hsp might involve an effect on the autonomic nervous system.

  6. Effects of dehydration and rehydration on body temperatures in the black bedouin goat.

    Science.gov (United States)

    Jessen, C; Dmi'el, R; Choshniak, I; Ezra, D; Kuhnen, G

    1998-10-01

    The temperatures of the arterial blood and the brain in black Bedouin goats were measured continuously by miniature data loggers. The animals were either euhydrated or dehydrated to 75-80% of the initial body mass by withholding water for 3-4 days during exposure to intense solar radiation. The daily blood temperature means and maxima of were significantly higher in dehydration than in euhydration, but 40 degreesC was rarely exceeded even during the hot hours of the day. Selective brain cooling occurred in euhydration, but its extent was small when blood temperature was below 39.5 degreesC. In dehydration, however, selective brain cooling was frequent and the standard response when blood temperature exceeded 39 degreesC. We believe that selective brain cooling contributes to the inhibition of evaporative heat loss, which is the primary cause of the higher blood temperature in dehydration. Rapid rehydration with cold water induced long-lasting depression of blood temperature. No evidence was found for mechanisms attenuating the subsequent decrease of brain temperature which occurred a few minutes after the uptake of cold water.

  7. Cross-sectional area of the murine aorta linearly increases with increasing core body temperature.

    Science.gov (United States)

    Crouch, A Colleen; Manders, Adam B; Cao, Amos A; Scheven, Ulrich M; Greve, Joan M

    2017-11-06

    The cardiovascular (CV) system plays a vital role in thermoregulation. To date, the response of core vasculature to increasing core temperature has not been adequately studied in vivo. Our objective was to non-invasively quantify the arterial response in murine models due to increases in body temperature, with a focus on core vessels of the torso and investigate whether responses were dependent on sex or age. Male and female, adult and aged mice were anaesthetised and underwent magnetic resonance imaging (MRI). Data were acquired from the circle of Willis (CoW), heart, infrarenal aorta and peripheral arteries at core temperatures of 35, 36, 37 and 38 °C (±0.2 °C). Vessels in the CoW did not change. Ejection fraction decreased and cardiac output (CO) increased with increasing temperature in adult female mice. Cross-sectional area of the aorta increased significantly and linearly with temperature for all groups, but at a diminished rate for aged animals (p temperature are biologically important because they may affect conductive and convective heat transfer. Leveraging non-invasive methodology to quantify sex and age dependent vascular responses due to increasing core temperature could be combined with bioheat modelling in order to improve understanding of thermoregulation.

  8. Effect of short-term decrease in water temperature on body temperature and involvement of testosterone in steelhead and rainbow trout, Oncorhynchus mykiss.

    Science.gov (United States)

    Miura, Go; Munakata, Arimune; Yada, Takashi; Schreck, Carl B; Noakes, David L G; Matsuda, Hiroyuki

    2013-09-01

    The Pacific salmonid species Oncorhynchus mykiss is separated into a migratory form (steelhead trout) and a non-migratory form (rainbow trout). A decrease in water temperature is likely a cue triggering downstream behavior in the migratory form, and testosterone inhibits onset of this behavior. To elucidate differences in sensitivity to water temperature decreases between the migratory and non-migratory forms and effect of testosterone on the sensitivity, we examined two experiments. In experiment 1, we compared changes in body temperature during a short-term decrease in water temperature between both live and dead steelhead and rainbow trout. In experiment 2, we investigated effects of testosterone on body temperature decrease in steelhead trout. Water temperature was decreased by 3°C in 30min. The body temperature of the steelhead decreased faster than that of the rainbow trout. In contrast, there was no significant difference in the decrease in body temperature between dead steelhead and rainbow trout specimens. The body temperature of the testosterone-treated steelhead trout decreased more slowly than that of control fish. Our results suggest that the migratory form is more sensitive to decreases in water temperature than the non-migratory form. Moreover, testosterone might play an inhibitory role in sensitivity to such decreases. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Body temperature changes during simulated bacterial infection in a songbird: fever at night and hypothermia during the day.

    Science.gov (United States)

    Sköld-Chiriac, Sandra; Nord, Andreas; Tobler, Michael; Nilsson, Jan-Åke; Hasselquist, Dennis

    2015-09-01

    Although fever (a closely regulated increase in body temperature in response to infection) typically is beneficial, it is energetically costly and may induce detrimentally high body temperatures. This can increase the susceptibility to energetic bottlenecks and risks of overheating in some organisms. Accordingly, it could be particularly interesting to study fever in small birds, which have comparatively high metabolic rates and high, variable body temperatures. We therefore investigated two aspects of fever and other sickness behaviours (circadian variation, dose dependence) in a small songbird, the zebra finch. We injected lipopolysaccharide (LPS) at the beginning of either the day or the night, and subsequently monitored body temperature, body mass change and food intake for the duration of the response. We found pronounced circadian variation in the body temperature response to LPS injection, manifested by (dose-dependent) hypothermia during the day but fever at night. This resulted in body temperature during the peak response being relatively similar during the day and night. Day-to-night differences might be explained in the context of circadian variation in body temperature: songbirds have a high daytime body temperature that is augmented by substantial heat production peaks during activity. This might require a trade-off between the benefit of fever and the risk of overheating. In contrast, at night, when body temperature is typically lower and less variable, fever can be used to mitigate infection. We suggest that the change in body temperature during infection in small songbirds is context dependent and regulated to promote survival according to individual demands at the time of infection. © 2015. Published by The Company of Biologists Ltd.

  10. Measurement of the body surface temperature by the method of laser photothermal radiometry

    International Nuclear Information System (INIS)

    Skvortsov, L A; Kirillov, V M

    2003-01-01

    The specific features of contactless measurements of the body surface temperature by the method of repetitively pulsed laser photothermal radiometry are considered and the requirements to the parameters of the laser and measurement scheme are formulated. The sensitivity of the method is estimated. The advantages of laser photothermal radiometry over the conventional passive radiometric method are discussed. (laser applications and other topics in quantum electronics)

  11. Effects of peripheral cold application on core body temperature and haemodynamic parameters in febrile patients.

    Science.gov (United States)

    Asgar Pour, Hossein; Yavuz, Meryem

    2014-04-01

    This study designed to assess the effects of peripheral cold application (PCA) on core body temperature and haemodynamic parameters in febrile patients. This study was an experimental, repeated-measures performed in the neurosurgical intensive-care unit. The research sample included all patients with fever in postoperative period. PCA was performed for 20 min. During fever, systolic blood pressure, mean arterial blood pressure and arterial oxygen saturation (O2 Sat) decreased by 5.07 ± 7.89 mm Hg, 0.191 ± 6.00 mm Hg and 0.742% ± 0.97%, respectively, whereas the pulse rate and diastolic blood pressure increased by 8.528 ± 4.42 beats/ min and 1.842 ± 6.9 mmHg, respectively. Immediately after PCA, core body temperature and pulse rate decreased by 0.3°C, 3.3 beats/min, respectively, whereas systolic, diastolic, mean arterial blood pressure and O2 Sat increased by, 1.40 mm Hg, 1.87 mm Hg, 0.98 mmHg and 0.27%, respectively. Thirty minutes after the end of PCA, core body temperature, diastolic, mean arterial blood pressure and pulse rate decreased by 0.57°C, 0.34 mm Hg, 0.60 mm Hg and 4.5 beats/min, respectively, whereas systolic blood pressure and O2 Sat increased by 0.98 mm Hg and 0.04%, respectively. The present results showed that PCA increases systolic, diastolic, mean arterial blood pressure and O2 Sat, and decreases core body temperature and pulse rate. © 2013 Wiley Publishing Asia Pty Ltd.

  12. Animal physiology. Summer declines in activity and body temperature offer polar bears limited energy savings.

    Science.gov (United States)

    Whiteman, J P; Harlow, H J; Durner, G M; Anderson-Sprecher, R; Albeke, S E; Regehr, E V; Amstrup, S C; Ben-David, M

    2015-07-17

    Polar bears (Ursus maritimus) summer on the sea ice or, where it melts, on shore. Although the physiology of "ice" bears in summer is unknown, "shore" bears purportedly minimize energy losses by entering a hibernation-like state when deprived of food. Such a strategy could partially compensate for the loss of on-ice foraging opportunities caused by climate change. However, here we report gradual, moderate declines in activity and body temperature of both shore and ice bears in summer, resembling energy expenditures typical of fasting, nonhibernating mammals. Also, we found that to avoid unsustainable heat loss while swimming, bears employed unusual heterothermy of the body core. Thus, although well adapted to seasonal ice melt, polar bears appear susceptible to deleterious declines in body condition during the lengthening period of summer food deprivation. Copyright © 2015, American Association for the Advancement of Science.

  13. Summer declines in activity and body temperature offer polar bears limited energy savings

    Science.gov (United States)

    Whiteman, J.P.; Harlow, H.J.; Durner, George M.; Anderson-Sprecher, R.; Albeke, Shannon E.; Regehr, Eric V.; Amstrup, Steven C.; Ben-David, M.

    2015-01-01

    Polar bears (Ursus maritimus) summer on the sea ice or, where it melts, on shore. Although the physiology of “ice” bears in summer is unknown, “shore” bears purportedly minimize energy losses by entering a hibernation-like state when deprived of food. Such a strategy could partially compensate for the loss of on-ice foraging opportunities caused by climate change. However, here we report gradual, moderate declines in activity and body temperature of both shore and ice bears in summer, resembling energy expenditures typical of fasting, nonhibernating mammals. Also, we found that to avoid unsustainable heat loss while swimming, bears employed unusual heterothermy of the body core. Thus, although well adapted to seasonal ice melt, polar bears appear susceptible to deleterious declines in body condition during the lengthening period of summer food deprivation.

  14. Central inhibitory effect of α-methyldopa on blood pressure, heart rate and body temperature of renal hypertensive rats

    NARCIS (Netherlands)

    Nijkamp, F.P.; Ezer, Joseph; Jong, Wybren de

    The central inhibitory effect of α-methyldopa on blood pressure, heart rate and body temperature was studied in conscious renal hypertensive rats. Systemic administration of α-methyldopa decreased mean arterial blood pressure and body temperature and caused a short lasting increase in heart rate

  15. Effects of Chronic Social Defeat Stress on Sleep and Circadian Rhythms Are Mitigated by Kappa-Opioid Receptor Antagonism.

    Science.gov (United States)

    Wells, Audrey M; Ridener, Elysia; Bourbonais, Clinton A; Kim, Woori; Pantazopoulos, Harry; Carroll, F Ivy; Kim, Kwang-Soo; Cohen, Bruce M; Carlezon, William A

    2017-08-09

    Stress plays a critical role in the neurobiology of mood and anxiety disorders. Sleep and circadian rhythms are affected in many of these conditions. Here we examined the effects of chronic social defeat stress (CSDS), an ethological form of stress, on sleep and circadian rhythms. We exposed male mice implanted with wireless telemetry transmitters to a 10 day CSDS regimen known to produce anhedonia (a depressive-like effect) and social avoidance (an anxiety-like effect). EEG, EMG, body temperature, and locomotor activity data were collected continuously during the CSDS regimen and a 5 day recovery period. CSDS affected numerous endpoints, including paradoxical sleep (PS) and slow-wave sleep (SWS), as well as the circadian rhythmicity of body temperature and locomotor activity. The magnitude of the effects increased with repeated stress, and some changes (PS bouts, SWS time, body temperature, locomotor activity) persisted after the CSDS regimen had ended. CSDS also altered mRNA levels of the circadian rhythm-related gene mPer2 within brain areas that regulate motivation and emotion. Administration of the κ-opioid receptor (KOR) antagonist JDTic (30 mg/kg, i.p.) before CSDS reduced stress effects on both sleep and circadian rhythms, or hastened their recovery, and attenuated changes in mPer2 Our findings show that CSDS produces persistent disruptions in sleep and circadian rhythmicity, mimicking attributes of stress-related conditions as they appear in humans. The ability of KOR antagonists to mitigate these disruptions is consistent with previously reported antistress effects. Studying homologous endpoints across species may facilitate the development of improved treatments for psychiatric illness. SIGNIFICANCE STATEMENT Stress plays a critical role in the neurobiology of mood and anxiety disorders. We show that chronic social defeat stress in mice produces progressive alterations in sleep and circadian rhythms that resemble features of depression as it appears in

  16. Forced-Air Warming Provides Better Control of Body Temperature in Porcine Surgical Patients.

    Science.gov (United States)

    Dent, Brian T; Stevens, Karla A; Clymer, Jeffrey W

    2016-09-09

    Background: Maintaining normothermia during porcine surgery is critical in ensuring subject welfare and recovery, reducing the risk of immune system compromise and surgical-site infection that can result from hypothermia. In humans, various methods of patient heating have been demonstrated to be useful, but less evaluation has been performed in techniques to prevent hypothermia perioperatively in pigs. Methods: We compared body temperature regulation during surgery before and after modification of the ambient temperature of the operating laboratories. Three different methods of heating were then compared; a standard circulating water mattress, a resistive fabric blanket, and a forced hot air system. The primary measure was percentage of temperature readings outside a specification range of 36.7-40.0 °C. Results: Tighter control of the ambient temperature while using a circulating water mattress reduced the occurrence of out-of-specification body temperature readings from 20.8% to 5.0%, with most of these the result of hypothermia. Use of a resistive fabric blanket further reduced out-of-specification readings to 1.5%, with a slight increase in the occurrence of hyperthermia. Use of a forced air system reduced out-of-specification readings to less 0.1%. Conclusions: Maintenance of normothermia perioperatively in pig can be improved by tightly controlling ambient temperatures. Use of a resistive blanket or a forced air system can lead to better control than a circulating water mattress, with the forced air system providing a faster response to temperature variations and less chance of hyperthermia.

  17. Forced-Air Warming Provides Better Control of Body Temperature in Porcine Surgical Patients

    Directory of Open Access Journals (Sweden)

    Brian T. Dent

    2016-09-01

    Full Text Available Background: Maintaining normothermia during porcine surgery is critical in ensuring subject welfare and recovery, reducing the risk of immune system compromise and surgical-site infection that can result from hypothermia. In humans, various methods of patient heating have been demonstrated to be useful, but less evaluation has been performed in techniques to prevent hypothermia perioperatively in pigs. Methods: We compared body temperature regulation during surgery before and after modification of the ambient temperature of the operating laboratories. Three different methods of heating were then compared; a standard circulating water mattress, a resistive fabric blanket, and a forced hot air system. The primary measure was percentage of temperature readings outside a specification range of 36.7–40.0 °C. Results: Tighter control of the ambient temperature while using a circulating water mattress reduced the occurrence of out-of-specification body temperature readings from 20.8% to 5.0%, with most of these the result of hypothermia. Use of a resistive fabric blanket further reduced out-of-specification readings to 1.5%, with a slight increase in the occurrence of hyperthermia. Use of a forced air system reduced out-of-specification readings to less 0.1%. Conclusions: Maintenance of normothermia perioperatively in pig can be improved by tightly controlling ambient temperatures. Use of a resistive blanket or a forced air system can lead to better control than a circulating water mattress, with the forced air system providing a faster response to temperature variations and less chance of hyperthermia.

  18. Evidence for Reduced Fatigue Resistance of Contemporary Rotary Instruments Exposed to Body Temperature.

    Science.gov (United States)

    de Vasconcelos, Rafaela Andrade; Murphy, Sarah; Carvalho, Claudio Antonio Talge; Govindjee, Rajiv G; Govindjee, Sanjay; Peters, Ove A

    2016-05-01

    The purpose of this study was to evaluate the effect of 2 different temperatures (20°C and 37°C) on the cyclic fatigue life of rotary instruments and correlate the results with martensitic transformation temperatures. Contemporary nickel-titanium rotary instruments (n = 20 each and tip size #25, including Hyflex CM [Coltene, Cuyahoga Falls, OH], TRUShape [Dentsply Tulsa Dental Specialties, Tulsa, OK], Vortex Blue [Dentsply Tulsa Dental Specialties], and ProTaper Universal [Dentsply Tulsa Dental Specialties]) were tested for cyclic fatigue at room temperature (20°C ± 1°C) and at body temperature (37°C ± 1°C). Instruments were rotated until fracture occurred in a simulated canal with an angle curvature of about 60° and a radius curvature of 3 mm; the center of the curvature was 4.5 mm from the instrument tip. The number of cycles to fracture was measured. Phase transformation temperatures for 2 instruments of each brand were analyzed by differential scanning calorimetry. Data were analyzed using the t test and 1-way analysis of variance with the significance level set at 0.05. For the tested size and at 20°C, Hyflex CM showed the highest resistance to fracture; no significant difference was found between TRUShape and Vortex Blue, whereas ProTaper Universal showed the lowest resistance to fracture. At 37°C, resistance to fatigue fracture was significantly reduced, up to 85%, for the tested instruments (P temperature, Hyflex CM and Vortex Blue had similar and higher fatigue resistance compared with TRUShape and ProTaper Universal. Under the conditions of this study, using a novel testing design, immersion in water at simulated body temperature was associated with a marked decrease in the fatigue life of all rotary instruments tested. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  19. Design, development and implementation of the IR signaling techniques for monitoring ambient and body temperature

    International Nuclear Information System (INIS)

    Baqai, A.

    2014-01-01

    Healthcare systems such as hospitals, homecare, telemedicine, and physical rehabilitation are expected to be revolutionized by WBAN (Wireless Body Area Networks). This research work aims to investigate, design, optimize, and demonstrate the applications of IR (Infra-Red) communication systems in WBAN. It is aimed to establish a prototype WBAN system capable of measuring Ambient and Body Temperature using LM35 as temperature sensor and transmitting and receiving the data using optical signals. The corresponding technical challenges that have to be faced are also discussed in this paper. Investigations are carried out to efficiently design the hardware using low-cost and low power optical transceivers. The experimental results reveal the successful transmission and reception of Ambient and Body Temperatures over short ranges i.e. up to 3-4 meters. A simple IR transceiver with an LED (Light Emitting Diodes), TV remote control IC and Arduino microcontroller is designed to perform the transmission with sufficient accuracy and ease. Experiments are also performed to avoid interference from other sources like AC and TV remote control signals by implementing IR tags. (author)

  20. Anaphylaxis Imaging: Non-Invasive Measurement of Surface Body Temperature and Physical Activity in Small Animals.

    Directory of Open Access Journals (Sweden)

    Krisztina Manzano-Szalai

    Full Text Available In highly sensitized patients, the encounter with a specific allergen from food, insect stings or medications may rapidly induce systemic anaphylaxis with potentially lethal symptoms. Countless animal models of anaphylaxis, most often in BALB/c mice, were established to understand the pathophysiology and to prove the safety of different treatments. The most common symptoms during anaphylactic shock are drop of body temperature and reduced physical activity. To refine, improve and objectify the currently applied manual monitoring methods, we developed an imaging method for the automated, non-invasive measurement of the whole-body surface temperature and, at the same time, of the horizontal and vertical movement activity of small animals. We tested the anaphylaxis imaging in three in vivo allergy mouse models for i milk allergy, ii peanut allergy and iii egg allergy. These proof-of-principle experiments suggest that the imaging technology represents a reliable non-invasive method for the objective monitoring of small animals during anaphylaxis over time. We propose that the method will be useful for monitoring diseases associated with both, changes in body temperature and in physical behaviour.

  1. [Comparison of body temperatures in children measured using 3 different thermometers: tympanic, skin and digital axillary].

    Science.gov (United States)

    Padilla-Raygoza, Nicolás; Ruiz-Paloalto, M Laura; Díaz-Guerrero, Rosalina; Olvera-Villanueva, Georgina; Maldonado, Angélica; Raygoza-Mendoza, María Del Pilar

    2014-01-01

    To compare body temperature measurements using tympanic, skin and digital axillary thermometers. Hospitalized or outpatient children from the General Hospital Celaya, ISSSTE Hospital Clinic and General Hospital No. 4 IMSS, and the pediatric private service in Celaya, Guanajuato, from 1 day of life until 16 years old, were recruited over a one month period, after their parents signed the consent form. The order of each institution was selected by simple randomization. Body temperatures were measured in triplicate using tympanic, skin and digital axillary thermometers. The sample consisted of 554 children. The Pearson r between the tympanic and digital axillary thermometers was 0.57 to 0.65, with a positive linear relationship (P<.05); between the skin and the digital axillary thermometers, it was between 0.47 and 0.52 with a positive linearrelationship (P<.05). The intra-observer Kappa for the tympanic thermometer was 0.86, and for the inter-observer was 0.77; for the skin thermometer it was 0.82 and 0.67, respectively, and for the digital axillary thermometer it was 0.86 for intra-observer reliability and 0.78 for inter -observer reliability. Tympanic and axillary thermometers showed better precision in measuring the body temperature in children than skin thermometers. Copyright © 2013 Elsevier España, S.L. All rights reserved.

  2. Conservatism of lizard thermal tolerances and body temperatures across evolutionary history and geography.

    Science.gov (United States)

    Grigg, Joseph W; Buckley, Lauren B

    2013-04-23

    Species may exhibit similar thermal tolerances via either common ancestry or environmental filtering and local adaptation, if the species inhabit similar environments. We ask whether upper and lower thermal limits (critical thermal maxima and minima) and body temperatures are more strongly conserved across evolutionary history or geography for lizard populations distributed globally. We find that critical thermal maxima are highly conserved with location accounting for a higher proportion of the variation than phylogeny. Notably, thermal tolerance breadth is conserved across the phylogeny despite critical thermal minima showing little niche conservatism. Body temperatures observed during activity in the field show the greatest degree of conservatism, with phylogeny accounting for most of the variation. This suggests that propensities for thermoregulatory behaviour, which can buffer body temperatures from environmental variation, are similar within lineages. Phylogeny and geography constrain thermal tolerances similarly within continents, but variably within clades. Conservatism of thermal tolerances across lineages suggests that the potential for local adaptation to alleviate the impacts of climate change on lizards may be limited.

  3. Effect of body size and temperature on respiration of Galaxias maculatus (Pisces: Galaxiidae)

    Science.gov (United States)

    Milano, D.; Vigliano, P.H.; Beauchamp, David A.

    2017-01-01

    Body mass and temperature are primary determinants of metabolic rate in ectothermic animals. Oxygen consumption of post-larval Galaxias maculatus was measured in respirometry trials under different temperatures (5–21°C) and varying body masses (0.1–>1.5 g) spanning a relevant range of thermal conditions and sizes. Specific respiration rates (R in g O2 g−1 d−1) declined as a power function of body mass and increased exponentially with temperature and was expressed as: R = 0.0007 * W −0.31 * e 0.13 * T. The ability of this model to predict specific respiration rate was evaluated by comparing observed values with those predicted by the model. Our findings suggest that the respiration rate of G. maculatus is the result of multiple interactive processes (intrinsic and extrinsic factors) that modulate each other in ‘meta-mechanistic’ ways; this would help to explain the species’ ability to undergo the complex ontogenetic habitat shifts observed in the lakes of the Andean Patagonic range.

  4. Autonomic control of body temperature and blood pressure: influences of female sex hormones.

    Science.gov (United States)

    Charkoudian, Nisha; Hart, Emma C J; Barnes, Jill N; Joyner, Michael J

    2017-06-01

    Female reproductive hormones exert important non-reproductive influences on autonomic regulation of body temperature and blood pressure. Estradiol and progesterone influence thermoregulation both centrally and peripherally, where estradiol tends to promote heat dissipation, and progesterone tends to promote heat conservation and higher body temperatures. Changes in thermoregulation over the course of the menstrual cycle and with hot flashes at menopause are mediated by hormonal influences on neural control of skin blood flow and sweating. The influence of estradiol is to promote vasodilation, which, in the skin, results in greater heat dissipation. In the context of blood pressure regulation, both central and peripheral hormonal influences are important as well. Peripherally, the vasodilator influence of estradiol contributes to the lower blood pressures and smaller risk of hypertension seen in young women compared to young men. This is in part due to a mechanism by which estradiol augments beta-adrenergic receptor mediated vasodilation, offsetting alpha-adrenergic vasoconstriction, and resulting in a weak relationship between muscle sympathetic nerve activity and total peripheral resistance, and between muscle sympathetic nerve activity and blood pressure. After menopause, with the loss of reproductive hormones, sympathetic nerve activity, peripheral resistance and blood pressure become more strongly related, and sympathetic nerve activity (which increases with age) becomes a more important contributor to the prevailing level of blood pressure. Continuing to increase our understanding of sex hormone influences on body temperature and blood pressure regulation will provide important insight for optimization of individualized health care for future generations of women.

  5. Development of a new method for the noninvasive measurement of deep body temperature without a heater.

    Science.gov (United States)

    Kitamura, Kei-Ichiro; Zhu, Xin; Chen, Wenxi; Nemoto, Tetsu

    2010-01-01

    The conventional zero-heat-flow thermometer, which measures the deep body temperature from the skin surface, is widely used at present. However, this thermometer requires considerable electricity to power the electric heater that compensates for heat loss from the probe; thus, AC power is indispensable for its use. Therefore, this conventional thermometer is inconvenient for unconstrained monitoring. We have developed a new dual-heat-flux method that can measure the deep body temperature from the skin surface without a heater. Our method is convenient for unconstrained and long-term measurement because the instrument is driven by a battery and its design promotes energy conservation. Its probe consists of dual-heat-flow channels with different thermal resistances, and each heat-flow-channel has a pair of IC sensors attached on its top and bottom. The average deep body temperature measurements taken using both the dual-heat-flux and then the zero-heat-flow thermometers from the foreheads of 17 healthy subjects were 37.08 degrees C and 37.02 degrees C, respectively. In addition, the correlation coefficient between the values obtained by the 2 methods was 0.970 (ppower supply. (c) 2009 IPEM. Published by Elsevier Ltd. All rights reserved.

  6. The Rhetorical Nature of Rhythm

    NARCIS (Netherlands)

    Balint, Mihaela; Dascalu, Mihai; Trausan-Matu, Stefan

    2017-01-01

    Up to date, linguistic rhythm has been studied for speech, but the rhythm of written texts has been merely recognized, and not analyzed or interpreted in connection to natural language tasks. We provide an extension of the textual rhythmic features we proposed in previous work, and

  7. Soil phosphorous and endogenous rhythms exert a larger impact than CO2 or temperature on nocturnal stomatal conductance in Eucalyptus tereticornis.

    Science.gov (United States)

    de Dios, Víctor Resco; Turnbull, Matthew H; Barbour, Margaret M; Ontedhu, Josephine; Ghannoum, Oula; Tissue, David T

    2013-11-01

    High nocturnal transpiration rates (5-15% of total water loss in terrestrial plants) may be adaptive under limited fertility, by increasing nutrient uptake or transport via transpiration-induced mass flow, but the response of stomata in the dark to environmental variables is poorly understood. Here we tested the impact of soil phosphorous (P) concentration, atmospheric CO2 concentration and air temperature on stomatal conductance (gs) during early and late periods in the night, as well as at midday in naturally, sun-lit glasshouse-grown Eucalyptus tereticornis Sm. seedlings. Soil P was the main driver of nocturnal gs, which was consistently higher in low soil P (37.3-79.9 mmol m(-2) s(-1)) than in high soil P (17.7-49.3 mmol m(-2)(-1)). Elevated temperature had only a marginal (P = 0.07) effect on gs early in the night (gs decreased from 34.7 to 25.8 mmol m(-2) s(-1) with an increase in temperature of 4 °C). The effect of CO2 depended on its interaction with temperature. Stomatal conductance responses to soil P were apparently driven by indirect effects of soil P on plant anatomy, since gs was significantly and negatively correlated with wood density. However, the relationship of gs with environmental factors became weaker late in the night, relative to early in the night, likely due to apparent endogenous processes; gs late in the night was two times larger than gs observed early in the night. Time-dependent controls over nocturnal gs suggest that daytime stomatal models may not apply during the night, and that different types of regulation may occur even within a single night. We conclude that the enhancement of nocturnal gs under low soil P availability is unlikely to be adaptive in our species because of the relatively small amount of transpiration-induced mass flow that can be achieved through rates of nocturnal water loss (3-6% of daytime mass flow).

  8. Theoretical and Experimental Studies of Epidermal Heat Flux Sensors for Measurements of Core Body Temperature.

    Science.gov (United States)

    Zhang, Yihui; Webb, Richard Chad; Luo, Hongying; Xue, Yeguang; Kurniawan, Jonas; Cho, Nam Heon; Krishnan, Siddharth; Li, Yuhang; Huang, Yonggang; Rogers, John A

    2016-01-07

    Long-term, continuous measurement of core body temperature is of high interest, due to the widespread use of this parameter as a key biomedical signal for clinical judgment and patient management. Traditional approaches rely on devices or instruments in rigid and planar forms, not readily amenable to intimate or conformable integration with soft, curvilinear, time-dynamic, surfaces of the skin. Here, materials and mechanics designs for differential temperature sensors are presented which can attach softly and reversibly onto the skin surface, and also sustain high levels of deformation (e.g., bending, twisting, and stretching). A theoretical approach, together with a modeling algorithm, yields core body temperature from multiple differential measurements from temperature sensors separated by different effective distances from the skin. The sensitivity, accuracy, and response time are analyzed by finite element analyses (FEA) to provide guidelines for relationships between sensor design and performance. Four sets of experiments on multiple devices with different dimensions and under different convection conditions illustrate the key features of the technology and the analysis approach. Finally, results indicate that thermally insulating materials with cellular structures offer advantages in reducing the response time and increasing the accuracy, while improving the mechanics and breathability. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Theoretical and Experimental Studies of Epidermal Heat Flux Sensors for Measurements of Core Body Temperature

    Science.gov (United States)

    Zhang, Yihui; Webb, Richard Chad; Luo, Hongying; Xue, Yeguang; Kurniawan, Jonas; Cho, Nam Heon; Krishnan, Siddharth; Li, Yuhang; Huang, Yonggang

    2016-01-01

    Long-term, continuous measurement of core body temperature is of high interest, due to the widespread use of this parameter as a key biomedical signal for clinical judgment and patient management. Traditional approaches rely on devices or instruments in rigid and planar forms, not readily amenable to intimate or conformable integration with soft, curvilinear, time-dynamic, surfaces of the skin. Here, materials and mechanics designs for differential temperature sensors are presented which can attach softly and reversibly onto the skin surface, and also sustain high levels of deformation (e.g., bending, twisting, and stretching). A theoretical approach, together with a modeling algorithm, yields core body temperature from multiple differential measurements from temperature sensors separated by different effective distances from the skin. The sensitivity, accuracy, and response time are analyzed by finite element analyses (FEA) to provide guidelines for relationships between sensor design and performance. Four sets of experiments on multiple devices with different dimensions and under different convection conditions illustrate the key features of the technology and the analysis approach. Finally, results indicate that thermally insulating materials with cellular structures offer advantages in reducing the response time and increasing the accuracy, while improving the mechanics and breathability. PMID:25953120

  10. Color of hot soup modulates postprandial satiety, thermal sensation, and body temperature in young women.

    Science.gov (United States)

    Suzuki, Maki; Kimura, Rie; Kido, Yasue; Inoue, Tomoko; Moritani, Toshio; Nagai, Narumi

    2017-07-01

    The color of food is known to modulate not only consumers' motivation to eat, but also thermal perception. Here we investigated whether the colors of hot soup can influence thermal sensations and body temperature, in addition to the food acceptability and appetite. Twelve young female participants consumed commercial white potage soup, modified to yellow or blue by adding food dyes, at 9 a.m. on 3 separated days. During the test, visual impression (willingness to eat, palatability, comfort, warmth, and anxiety) and thermal sensations were self-reported using visual analog scales. Core (intra-aural) and peripheral (toe) temperatures were continuously recorded 10 min before and 60 min after ingestion. Blue soup significantly decreased willingness to eat, palatability, comfort, and warmth ratings, and significantly increased anxiety feelings compared to the white and yellow soups. After ingestion, the blue soup showed significantly smaller satiety ratings and the tendency of lower thermal sensation scores of the whole body compared to the white and yellow soups. Moreover, a significantly greater increase in toe temperature was found with the yellow soup than the white or blue soup. In conclusion, this study provides new evidence that the colors of hot food may modulate postprandial satiety, thermal sensations and peripheral temperature. Such effects of color may be useful for dietary strategies for individuals who need to control their appetite. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Effects of temperature and body size on radiocaesium retention in brown trout, Salmo trutta

    International Nuclear Information System (INIS)

    Ugedal, O.; Jonsson, B.; Njastad, O.; Naeumann, R.

    1992-01-01

    The elimination rate of radiocaesium in brown trout Salmo trutta L. was determined in the laboratory at four water temperatures (range 4.4 -15.6 0 C). In the experiments three or four homogeneous size-groups of fish (mean weights 23-496g) were studied at each temperature. The brown trout received acute oral doses of 134 Cs and were killed at intervals for radioactivity counting. The retention versus time curves were composed of two distinct exponential components. The long-lived component was quantitatively the most important for retention of radiocaesium. Elimination rate increased with increasing water temperature and decreased with increasing body weight. The biological half-life of 134 Cs (T b , days) was related to fresh body weight (W, g) and water temperature (t, 0 C) by the equation: T b = 290 x W 0.176 x e -0.106 x t . The elimination rate of Cs could be predicted from weight-specific metabolic rate as given by Elliott's equations for brown trout. (author)

  12. Central and peripheral des-acyl ghrelin regulates body temperature in rats.

    Science.gov (United States)

    Inoue, Yoshiyuki; Nakahara, Keiko; Maruyama, Keisuke; Suzuki, Yoshiharu; Hayashi, Yujiro; Kangawa, Kenji; Murakami, Noboru

    2013-01-04

    In the present study using rats, we demonstrated that central and peripheral administration of des-acyl ghrelin induced a decrease in the surface temperature of the back, and an increase in the surface temperature of the tail, although the effect of peripheral administration was less marked than that of central administration. Furthermore, these effects of centrally administered des-acyl ghrelin could not be prevented by pretreatment with [D-Lys3]-GHRP-6 GH secretagogue receptor 1a (GHS-R1a) antagonists. Moreover, these actions of des-acyl ghrelin on body temperature were inhibited by the parasympathetic nerve blocker methylscopolamine but not by the sympathetic nerve blocker timolol. Using immunohistochemistry, we confirmed that des-acyl ghrelin induced an increase of cFos expression in the median preoptic nucleus (MnPO). Additionally, we found that des-acyl ghrelin dilated the aorta and tail artery in vitro. These results indicate that centrally administered des-acyl ghrelin regulates body temperature via the parasympathetic nervous system by activating neurons in the MnPO through interactions with a specific receptor distinct from the GHS-R1a, and that peripherally administered des-acyl ghrelin acts on the central nervous system by passing through the blood-brain barrier, whereas it exerts a direct action on the peripheral vascular system. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. Systems biology of cellular rhythms.

    Science.gov (United States)

    Goldbeter, A; Gérard, C; Gonze, D; Leloup, J-C; Dupont, G

    2012-08-31

    Rhythms abound in biological systems, particularly at the cellular level where they originate from the feedback loops present in regulatory networks. Cellular rhythms can be investigated both by experimental and modeling approaches, and thus represent a prototypic field of research for systems biology. They have also become a major topic in synthetic biology. We review advances in the study of cellular rhythms of biochemical rather than electrical origin by considering a variety of oscillatory processes such as Ca++ oscillations, circadian rhythms, the segmentation clock, oscillations in p53 and NF-κB, synthetic oscillators, and the oscillatory dynamics of cyclin-dependent kinases driving the cell cycle. Finally we discuss the coupling between cellular rhythms and their robustness with respect to molecular noise.

  14. [Circadian rhythms and systems biology].

    Science.gov (United States)

    Goldbeter, Albert; Gérard, Claude; Leloup, Jean-Christophe

    2010-01-01

    Cellular rhythms represent a field of choice for studies in system biology. The examples of circadian rhythms and of the cell cycle show how the experimental and modeling approaches contribute to clarify the conditions in which periodic behavior spontaneously arises in regulatory networks at the cellular level. Circadian rhythms originate from intertwined positive and negative feedback loops controlling the expression of several clock genes. Models can be used to address the dynamical bases of physiological disorders related to dysfunctions of the mammalian circadian clock. The cell cycle is driven by a network of cyclin-dependent kinases (Cdks). Modeled in the form of four modules coupled through multiple regulatory interactions, the Cdk network operates in an oscillatory manner in the presence of sufficient amounts of growth factor. For circadian rhythms and the cell cycle, as for other recently observed cellular rhythms, periodic behavior represents an emergent property of biological systems related to their regulatory structure.

  15. The influence of body temperature on image contrast in post mortem MRI.

    Science.gov (United States)

    Ruder, Thomas D; Hatch, Gary M; Siegenthaler, Lea; Ampanozi, Garyfalia; Mathier, Sandra; Thali, Michael J; Weber, Oliver M

    2012-06-01

    To assess the temperature dependency of tissue contrast on post mortem magnetic resonance (PMMR) images both objectively and subjectively; and to visually demonstrate the changes of image contrast at various temperatures. The study was approved by the responsible justice department and the ethics committee. The contrast of water, fat, and muscle was measured using regions of interest (ROI) in the orbit of 41 human corpses to assess how body temperature (range 2.1-39.8 °C) relates to image contrast of T1-weighted (T1W) and T2-weighted (T2W) sequences on PMMR. Regressions were calculated using the method of least squares. Three readers judged visible changes of image contrast subjectively by consensus. There was a positive relationship between temperature and contrast on T1-weighted (T1W) images and between temperature and the contrast of fat/muscle on T2-weighted (T2W) images. There was a negative relationship between temperature and the contrast of water/fat and water/muscle on T2W images. Subjectively, the influence of temperature became visible below 20 °C on T2W images, and below 10 °C on T1W images. Image contrast on PMMR depends on the temperature of a corpse. Radiologists involved in post mortem imaging must be aware of temperature-related changes in MR image contrast. To preserve technical quality, scanning corpses below 10 °C should be avoided. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  16. The influence of body temperature on image contrast in post mortem MRI

    International Nuclear Information System (INIS)

    Ruder, Thomas D.; Hatch, Gary M.; Siegenthaler, Lea; Ampanozi, Garyfalia; Mathier, Sandra; Thali, Michael J.; Weber, Oliver M.

    2012-01-01

    Objective: To assess the temperature dependency of tissue contrast on post mortem magnetic resonance (PMMR) images both objectively and subjectively; and to visually demonstrate the changes of image contrast at various temperatures. Materials and methods: The study was approved by the responsible justice department and the ethics committee. The contrast of water, fat, and muscle was measured using regions of interest (ROI) in the orbit of 41 human corpses to assess how body temperature (range 2.1–39.8 °C) relates to image contrast of T1-weighted (T1W) and T2-weighted (T2W) sequences on PMMR. Regressions were calculated using the method of least squares. Three readers judged visible changes of image contrast subjectively by consensus. Results: There was a positive relationship between temperature and contrast on T1-weighted (T1W) images and between temperature and the contrast of fat/muscle on T2-weighted (T2W) images. There was a negative relationship between temperature and the contrast of water/fat and water/muscle on T2W images. Subjectively, the influence of temperature became visible below 20 °C on T2W images, and below 10 °C on T1W images. Conclusion: Image contrast on PMMR depends on the temperature of a corpse. Radiologists involved in post mortem imaging must be aware of temperature-related changes in MR image contrast. To preserve technical quality, scanning corpses below 10 °C should be avoided.

  17. Effect of Body Temperature on the Radionuclide Evaluation of Cerebral Blood Flow

    International Nuclear Information System (INIS)

    Mustafa, S. . E- mail: seham@hsc.edu.kw; Elgazzar, A.H.; Gopinath, S.; Mathew, M.; Khalil, M.

    2006-01-01

    Changes in regional cerebral blood flow (rCBF) may reflect physiological correlates of the disease state. In neuro-imaging studies, some diseases have frequently been reported to be associated with reduced or increased rCBF. In a previous study we had shown evidence of heat induced vasoconstriction of the carotid artery, which is the main vessel supplying blood to the brain. This vasoconstriction may lead to a decrease in cerebral blood flow in hyperthermic patients. Most radionuclide studies used to assess cerebral blood flow are routinely performed without taking into consideration patients' body temperature. In this regard it may be noted that results of radionuclide cerebral perfusion studies may be affected by hyperthermia, which could lead to false positive studies or misinterpretation of results when they are performed on patients suffering from various cerebrovascular diseases. The objective of the present study was to investigate the importance of body temperature and its effect on the results of radionuclide cerebral perfusion studies. Cerebral blood flow was assessed using Tc-99m hexamethylpropyleneamineoxime (Tc-99m HMPAO) imaging. Baseline scintigraphic images of the brain were obtained in 10 rabbits using a gamma camera equipped with a low energy parallel hole and high resolution collimator interfaced with a computer. Repeat brain studies were performed on the same rabbits at 3 and 6 days after raising the body temperature by 2 deg. C and 4 deg. C respectively using the same imaging protocol. The counts per pixel were determined on control and hyperthermia images. The uptake of Tc-99m HMPAO in the brain was found to be significantly reduced following hyperthermia implying reduction in blood flow. This decrease in cerebral perfusion appears to be variable from region to region, being more in the cerebral hemispheres, frontal areas (olfactory lobes) than in the cerebellum. Based on the results, the authors conclude that a rise in body temperature might

  18. Body temperature change in live and dead gizzard shad, Dorosoma Cepedianum

    Energy Technology Data Exchange (ETDEWEB)

    Beitinger, T. L.; Thommes, M. M.; Spigarelli, S. A.; Rowland, R. E.

    1975-01-01

    Temperature change kinetics were determined for a sample of 22 gizzard shad, ranging in weight from 13.2 to 467.5 grams. Tests consisted of monitoring the intestinal temperatures of shad transferred between two well aerated water baths held at 9.2 +- 0.13 C (mean and standard error) and 18.7 +- 0.08 C. None of the 22 live shad subjected to the +- ..delta..T of 9.5 C died during exposure. The similarity of double logarithmic regressions of body weight and half-time (Table 1) indicate that neither the direction of exposure nor the state of the test fish greatly influenced temperature change kinetics.

  19. A study on changes in body surface temperature and thermal effect according to ultrasound mode

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Sung Hee [Dept. of Radiology, Ilsin Christian Hospital, Busan (Korea, Republic of); Lee, Jin Soo [Dept. of Radiology, University Haeundae Paik Hospital, Busan (Korea, Republic of)

    2017-06-15

    Recently, as the number of high-risk pregnancies increases, the use of new techniques such as Doppler, which have higher acoustic power than in the past, has been increasingly used in prenatal diagnosis and guidelines have been set up by various organizations to prevent excessive exposure. Therefore, in this study, we tried to investigate the temperature change of the body surface for each test mode according to the long time ultrasound examination and to examine the exposure time which is not influenced by the thermal effect. B mode, C mode, and PD mode according to time, and the temperature difference between exposed and unexposed sites were compared. As a result, the B mode showed a significant difference in the temperature change from 10 minutes, 50 minutes after exposed, 20 minutes from the C mode, and 30 minutes from the PD mode (p<0.01). In all three modes, the temperature difference was different(p<0.000), and PD mode was the most sensitive to temperature change. Also, it was found that the temperature rise time was shortened with the increase of the ultrasonic exposure time. Therefore, it is recommended that ultrasonography to observe the embryo or fetus should be used only for diagnostic purposes, avoiding excessive test time.

  20. The effect of lower body cooling on the changes in three core temperature indices

    International Nuclear Information System (INIS)

    Basset, F A; Cahill, F; Handrigan, G; DuCharme, M B; Cheung, S S

    2011-01-01

    Rectal (T re ), ear canal (T ear ) and esophageal (T es ) temperatures have been used in the literature as core temperature indices in humans. The aim of the study was to investigate if localized lower body cooling would have a different effect on each of these measurements. We hypothesized that prolonged lower body surface cooling will result in a localized cooling effect for the rectal temperature not reflected in the other core measurement sites. Twelve participants (mean ± SD; 26.8 ± 6.0 years; 82.6 ± 13.9 kg; 179 ± 10 cm, BSA = 2.00 ± 0.21 m 2 ) attended one experimental session consisting of sitting on a rubberized raft floor surface suspended in 5 °C water in a thermoneutral air environment (∼21.5 ± 0.5 °C). Experimental conditions were (a) a baseline phase during which participants were seated for 15 min in an upright position on an insulated pad (1.408 K . m 2 . W −1 ); (b) a cooling phase during which participants were exposed to the cooling surface for 2 h, and (c) an insulation phase during which the baseline condition was repeated for 1 h. Temperature data were collected at 1 Hz, reduced to 1 min averages, and transformed from absolute values to a change in temperature from baseline (15 min average). Metabolic data were collected breath-by-breath and integrated over the same temperature epoch. Within the baseline phase no significant change was found between the three indices of core temperature. By the end of the cooling phase, T re was significantly lower (Δ = −1.0 ± 0.4 °C) from baseline values than from T ear (Δ = −0.3 ± 0.3 °C) and T es (Δ = −0.1 ± 0.3 °C). T re continued to decrease during the insulation phase from Δ −1.0 ± 0.4 °C to as low as Δ −1.4 ± 0.5 °C. By the end of the insulation phase T re had slightly risen back to Δ −1.3 ± 0.4 °C but remained significantly different from baseline values and from the other two core measures. Metabolic data showed no variation throughout the experiment. In

  1. Hepatic mTORC1 controls locomotor activity, body temperature, and lipid metabolism through FGF21

    Science.gov (United States)

    Cornu, Marion; Oppliger, Wolfgang; Albert, Verena; Robitaille, Aaron M.; Trapani, Francesca; Quagliata, Luca; Fuhrer, Tobias; Sauer, Uwe; Terracciano, Luigi; Hall, Michael N.

    2014-01-01

    The liver is a key metabolic organ that controls whole-body physiology in response to nutrient availability. Mammalian target of rapamycin (mTOR) is a nutrient-activated kinase and central controller of growth and metabolism that is negatively regulated by the tumor suppressor tuberous sclerosis complex 1 (TSC1). To investigate the role of hepatic mTOR complex 1 (mTORC1) in whole-body physiology, we generated liver-specific Tsc1 (L-Tsc1 KO) knockout mice. L-Tsc1 KO mice displayed reduced locomotor activity, body temperature, and hepatic triglyceride content in a rapamycin-sensitive manner. Ectopic activation of mTORC1 also caused depletion of hepatic and plasma glutamine, leading to peroxisome proliferator–activated receptor γ coactivator-1α (PGC-1α)–dependent fibroblast growth factor 21 (FGF21) expression in the liver. Injection of glutamine or knockdown of PGC-1α or FGF21 in the liver suppressed the behavioral and metabolic defects due to mTORC1 activation. Thus, mTORC1 in the liver controls whole-body physiology through PGC-1α and FGF21. Finally, mTORC1 signaling correlated with FGF21 expression in human liver tumors, suggesting that treatment of glutamine-addicted cancers with mTOR inhibitors might have beneficial effects at both the tumor and whole-body level. PMID:25082895

  2. Extremely Low Birth Weight Preterm Infants Lack Vasomotor Response in Relationship to Cold Body Temperatures at Birth

    OpenAIRE

    Knobel, Robin B.; Holditch-Davis, Diane; Schwartz, Todd A.; Wimmer, John E.

    2009-01-01

    Objective This study evaluated peripheral vasoconstriction in ELBW infants when body temperature decreased during the first 12-hours of life. Design An exploratory, within-subjects design with 10 ELBW infants. Abdominal and foot temperatures were measured every minute. Peripheral vasoconstriction (abdominal > peripheral temperature by 2? C) and abdominal-peripheral temperature difference were also evaluated. Results Abdominal and peripheral temperatures were significantly correlated within ea...

  3. Diurnal variation in the control of ventilation in response to rising body temperature during exercise in the heat.

    Science.gov (United States)

    Tsuji, Bun; Honda, Yasushi; Kondo, Narihiko; Nishiyasu, Takeshi

    2016-08-01

    We investigated whether heat-induced hyperventilation during exercise is affected by time of day, as diurnal variation leads to higher core temperatures in the evening. Nineteen male subjects were divided into two experiments (protocol 1, n = 10 and protocol 2, n = 9). In protocol 1, subjects performed cycle exercise at 50% peak oxygen uptake in the heat (37°C and 50% RH) in the morning (0600) and evening (1800). Results showed that baseline resting and exercising esophageal temperature (Tes) were significantly (0.5°C) higher in the evening than morning. Minute ventilation (V̇e) increased from 54.3 ± 7.9 and 54.9 ± 6.8 l/min at 10 min to 71.4 ± 8.1 and 76.5 ± 11.8 l/min at 48.5 min in the morning and evening, respectively (both P temperature is smaller in the evening. In protocol 2, the circadian rhythm-related higher resting Tes seen in the evening was adjusted down to the same temperature seen in the morning by immersing the subject in cold water. Importantly, the time course of changes in V̇e during exercise were smaller in the evening, but the threshold for V̇e remained higher in the evening than morning (P temperatures in the evening. This is likely due to diurnal variation in the control of ventilation in response to rising core temperature. Copyright © 2016 the American Physiological Society.

  4. Measurement of bovine body and scrotal temperature using implanted temperature sensitive radio transmitters, data loggers and infrared thermography.

    Science.gov (United States)

    Wallage, A L; Gaughan, J B; Lisle, A T; Beard, L; Collins, C W; Johnston, S D

    2017-07-01

    Synchronous and continuous measurement of body (BT) and scrotal temperature (ST) without adverse welfare or behavioural interference is essential for understanding thermoregulation of the bull testis. This study compared three technologies for their efficacy for long-term measurement of the relationship between BT and ST by means of (1) temperature sensitive radio transmitters (RT), (2) data loggers (DL) and (3) infrared imaging (IRI). After an initial pilot study on two bulls to establish a surgical protocol, RTs and DLs were implanted into the flank and mid-scrotum of six Wagyu bulls for between 29 and 49 days. RT frequencies were scanned every 15 min, whilst DLs logged every 30 min. Infrared imaging of the body (flank) and scrotum of each bull was recorded hourly for one 24-h period and compared to RT and DL data. After a series of subsequent heat stress studies, bulls were castrated and testicular tissue samples processed for evidence of histopathology. Radio transmitters were less reliable than DLs; RTs lost >11 % of data, whilst 11 of the 12 DLs had 0 % data loss. IRI was only interpretable in 35.8 % of images recorded. Pearson correlations between DL and RT were strong for both BT (r > 0.94, P  0.80, P < 0.001). Surgery produced temporary minor inflammation and scrotal hematoma in two animals post-surgery. Whilst scar tissue was observed at all surgical sutured sites when bulls were castrated, there was no evidence of testicular adhesion and normal active spermatogenesis was observed in six of the eight implanted testicles. There was no significant correlation of IRI with either DL or RT. We conclude that DLs provided to be a reliable continuous source of data for synchronous measurement of BT and ST.

  5. Measurement of bovine body and scrotal temperature using implanted temperature sensitive radio transmitters, data loggers and infrared thermography

    Science.gov (United States)

    Wallage, A. L.; Gaughan, J. B.; Lisle, A. T.; Beard, L.; Collins, C. W.; Johnston, S. D.

    2017-07-01

    Synchronous and continuous measurement of body (BT) and scrotal temperature (ST) without adverse welfare or behavioural interference is essential for understanding thermoregulation of the bull testis. This study compared three technologies for their efficacy for long-term measurement of the relationship between BT and ST by means of (1) temperature sensitive radio transmitters (RT), (2) data loggers (DL) and (3) infrared imaging (IRI). After an initial pilot study on two bulls to establish a surgical protocol, RTs and DLs were implanted into the flank and mid-scrotum of six Wagyu bulls for between 29 and 49 days. RT frequencies were scanned every 15 min, whilst DLs logged every 30 min. Infrared imaging of the body (flank) and scrotum of each bull was recorded hourly for one 24-h period and compared to RT and DL data. After a series of subsequent heat stress studies, bulls were castrated and testicular tissue samples processed for evidence of histopathology. Radio transmitters were less reliable than DLs; RTs lost >11 % of data, whilst 11 of the 12 DLs had 0 % data loss. IRI was only interpretable in 35.8 % of images recorded. Pearson correlations between DL and RT were strong for both BT ( r > 0.94, P 0.80, P animals post-surgery. Whilst scar tissue was observed at all surgical sutured sites when bulls were castrated, there was no evidence of testicular adhesion and normal active spermatogenesis was observed in six of the eight implanted testicles. There was no significant correlation of IRI with either DL or RT. We conclude that DLs provided to be a reliable continuous source of data for synchronous measurement of BT and ST.

  6. Body temperature control in patients with refractory septic shock: too much may be harmful.

    Science.gov (United States)

    Yang, Yan-Li; Liu, Da-Wei; Wang, Xiao-Ting; Long, Yun; Zhou, Xiang; Chai, Wen-Zao

    2013-01-01

    The lowering of body temperature is a common, almost reflexive step in the daily care of septic shock patient. However, the effect of different magnitudes of fever control on the outcome of refractory septic patients with a very poor outcome is controversial and has yet to be explored. This prospective trial examined sixty-five refractory septic shock patients with a core temperature higher than 38.5°C. Patients were randomly assigned to a group achieving a "low temperature" range (LT group: 36.0 - 37.5°C) or to a group achieving a "high temperature" range (HT group: 37.5 - 38.3°C) by physical methods including a water-flow cooling blanket and ice packs. A target core temperature was achieved in 1 - 2 hours post-treatment, and maintained for 72 hours. Averaged values of core temperature as well as hemodynamic, respiratory, and laboratory variables were analyzed at baseline and during the first 72 hours after fever control. Thirty-four (52.31%) patients were assigned to the LT group and thirty-one (47.69%) patients were assigned to the HT group. The mean core temperature was significantly lower in the LT group than in the HT group (36.61 vs. 37.85°C, respectively; P temperature during the 72 h period was an independent predictor of 28 days mortality (odds ratio (OR) = 0.42, 95%CI 0.25, 0.6; P = 0.001). Controlling fever to a lower range (36.0 - 37.5°C) may be harmful to patients with refractory septic shock by worsening tissue perfusion, compared to controlling it within a higher range (37.5 - 38.3°C). An understanding of the mechanisms responsible for these observations requires further investigation.

  7. Orchestrating intensities and rhythms

    DEFF Research Database (Denmark)

    Staunæs, Dorthe; Juelskjær, Malou

    2016-01-01

    The aim of this article is to trace how contemporary (post)psychologies, when used as psy-leadership tools in order to reach new standards, may create new work around the standards and may also create new subjectivities. It is well known that education is a field in which standardization and the ......The aim of this article is to trace how contemporary (post)psychologies, when used as psy-leadership tools in order to reach new standards, may create new work around the standards and may also create new subjectivities. It is well known that education is a field in which standardization...... environmentality and learning-centered governance standards has dramatic and performative effects for the production of (educational) subjectivities. This implies a shift from governing identities, categories and structures towards orchestrating affective intensities and rhythms. Finally, the article discusses...... possible new worries and vulnerabilities when school goes post-psychological....

  8. Weak 24-h periodicity of body temperature and increased plasma vasopressin in melancholic depression.

    NARCIS (Netherlands)

    van Londen, L.; Goekoop, J.G.; Kerkhof, G.A.; Zwindeman, K.H.; Wiegant, V.M.; de Wied, D.

    2001-01-01

    Earlier work has shown that plasma vasopressin levels of depressed patients were higher than those of healthy controls. The aim of the present study was to determine whether plasma vasopressin levels were correlated to parameters of the circadian rhythm. 41 patients with major depression (aged 22-77

  9. Wet Belly in Reindeer (Rangifer tarandus tarandus in Relation to Body Condition, Body Temperature and Blood Constituents

    Directory of Open Access Journals (Sweden)

    Olsson K

    2002-06-01

    Full Text Available Wet belly, when the reindeer becomes wet over the lower parts of the thorax and abdomen, sometimes occurs in reindeer during feeding. In a feeding experiment, 11 out of 69 reindeer were affected by wet belly. The problem was first observed in 7 animals during a period of restricted feed intake. When the animals were then fed standard rations, 3 additional animals fed only silage, and 1 fed pellets and silage, became wet. Four animals died and 1 had to be euthanised. To investigate why reindeer developed wet belly, we compared data from healthy reindeer and reindeer affected by wet belly. Urea, plasma protein, glucose, insulin and cortisol were affected by restricted feed intake or by diet but did not generally differ between healthy reindeer and those with wet belly. The wet animals had low body temperature and the deaths occurred during a period of especially cold weather. Animals that died were emaciated and showed different signs of infections and stress. In a second experiment, with 20 reindeer, the feeding procedure of the most affected group in the first experiment was repeated, but none of the reindeer showed any signs of wet belly. The study shows that wet belly is not induced by any specific diet and may affect also lichen-fed reindeer. The fluid making the fur wet was proven to be of internal origin. Mortality was caused by emaciation, probably secondary to reduced energy intake caused by diseases and/or unsuitable feed.

  10. Internal and external cooling methods and their effect on body temperature, thermal perception and dexterity.

    Directory of Open Access Journals (Sweden)

    Matthew J Maley

    Full Text Available The present study aimed to compare a range of cooling methods possibly utilised by occupational workers, focusing on their effect on body temperature, perception and manual dexterity.Ten male participants completed eight trials involving 30 min of seated rest followed by 30 min of cooling or control of no cooling (CON (34°C, 58% relative humidity. The cooling methods utilised were: ice cooling vest (CV0, phase change cooling vest melting at 14°C (CV14, evaporative cooling vest (CVEV, arm immersion in 10°C water (AI, portable water-perfused suit (WPS, heliox inhalation (HE and ice slushy ingestion (SL. Immediately before and after cooling, participants were assessed for fine (Purdue pegboard task and gross (grip and pinch strength manual dexterity. Rectal and skin temperature, as well as thermal sensation and comfort, were monitored throughout.Compared with CON, SL was the only method to reduce rectal temperature (P = 0.012. All externally applied cooling methods reduced skin temperature (P0.05.The present study observed that ice ingestion or ice applied to the skin produced the greatest effect on rectal and skin temperature, respectively. AI should not be utilised if workers require subsequent fine manual dexterity. These results will help inform future studies investigating appropriate pre-cooling methods for the occupational worker.

  11. Internal and external cooling methods and their effect on body temperature, thermal perception and dexterity

    Science.gov (United States)

    Minett, Geoffrey M.; Bach, Aaron J. E.; Zietek, Stephanie A.; Stewart, Kelly L.; Stewart, Ian B.

    2018-01-01

    Objective The present study aimed to compare a range of cooling methods possibly utilised by occupational workers, focusing on their effect on body temperature, perception and manual dexterity. Methods Ten male participants completed eight trials involving 30 min of seated rest followed by 30 min of cooling or control of no cooling (CON) (34°C, 58% relative humidity). The cooling methods utilised were: ice cooling vest (CV0), phase change cooling vest melting at 14°C (CV14), evaporative cooling vest (CVEV), arm immersion in 10°C water (AI), portable water-perfused suit (WPS), heliox inhalation (HE) and ice slushy ingestion (SL). Immediately before and after cooling, participants were assessed for fine (Purdue pegboard task) and gross (grip and pinch strength) manual dexterity. Rectal and skin temperature, as well as thermal sensation and comfort, were monitored throughout. Results Compared with CON, SL was the only method to reduce rectal temperature (P = 0.012). All externally applied cooling methods reduced skin temperature (Ptemperature versus other cooling methods. Participants felt cooler with CV0, CV14, WPS, AI and SL (P0.05). Conclusion The present study observed that ice ingestion or ice applied to the skin produced the greatest effect on rectal and skin temperature, respectively. AI should not be utilised if workers require subsequent fine manual dexterity. These results will help inform future studies investigating appropriate pre-cooling methods for the occupational worker. PMID:29357373

  12. Aminophylline partially prevents the decrease of body temperature during laparoscopic abdominal surgery.

    Science.gov (United States)

    Kim, Dae Woo; Lee, Jung Ah; Jung, Hong Soo; Joo, Jin Deok; In, Jang Hyeok; Jeon, Yeon Soo; Chun, Ga Young; Choi, Jin Woo

    2014-08-01

    Aminophylline can elicit thermogenesis in rats or increase metabolic rate during cold stress in lambs. We tested the hypothesis that aminophylline would reduce the change in core body temperature during laparoscopic abdominal surgery requiring pneumoperitoneum. Fifty patients were randomly divided into an aminophylline group (n=25) and a saline control group (n=25). Esophageal temperature, index finger temperature, and hemodynamic variables, such as mean blood pressure and heart rate, were measured every 15 min during sevoflurane anesthesia. In the aminophylline group, esophageal temperatures at T45 (36.1±0.38 vs. 35.7±0.29, P=0.024), T60 (36.0±0.39 vs. 35.6±0.28, P=0.053), T75 (35.9±0.34 vs. 35.5±0.28, P=0.025), T90 (35.8±0.35 vs. 35.3±0.33, P=0.011), and T105 (35.8±0.36 vs. 35.1±0.53, P=0.017) and index finger temperatures at T15 (35.8±0.46 vs. 34.9±0.33, Ptemperature through a thermogenic effect, despite reduced peripheral thermoregulatory vasoconstriction.

  13. Individualized estimation of human core body temperature using non-invasive measurements.

    Science.gov (United States)

    Laxminarayan, Srinivas; Rakesh, Vineet; Oyama, Tatsuya; Kazman, Josh B; Yanovich, Ran; Ketko, Itay; Epstein, Yoram; Morrison, Shawnda A; Reifman, Jaques

    2018-02-08

    A rising core body temperature (Tc) during strenuous physical activity is a leading indicator of heat-injury risk. Hence, a system that can estimate Tc in real time and provide early warning of an impending temperature rise may enable proactive interventions to reduce the risk of heat injuries. However, real-time field assessment of Tc requires impractical invasive technologies. To address this problem, we developed a mathematical model that describes the relationships between Tc and non-invasive measurements of an individual's physical activity, heart rate, and skin temperature, and two environmental variables (ambient temperature and relative humidity). A Kalman filter adapts the model parameters to each individual and provides real-time personalized Tc estimates. Using data from three distinct studies, comprising 166 subjects who performed treadmill and cycle ergometer tasks under different experimental conditions, we assessed model performance via the root mean squared error (RMSE). The individualized model yielded an overall average RMSE of 0.33{degree sign}C [standard deviation (SD) = 0.18], allowing us to reach the same conclusions in each study as those obtained using the Tc measurements. Furthermore, for 22 unique subjects whose Tc exceeded 38.5{degree sign}C, a potential lower core body temperature limit of clinical relevance, the average RMSE decreased to 0.25{degree sign}C (SD = 0.20). Importantly, these results remained robust in the presence of simulated real-world operational conditions, yielding no more than 16% worse RMSEs when measurements were missing (40%) or laden with added noise. Hence, the individualized model provides a practical means to develop an early warning system for reducing heat-injury risk.

  14. Effects of reproductive status and high ambient temperatures on the body temperature of a free-ranging basoendotherm.

    Science.gov (United States)

    Levesque, Danielle L; Lobban, Kerileigh D; Lovegrove, Barry G

    2014-12-01

    Tenrecs (Order Afrosoricida) exhibit some of the lowest body temperatures (T b) of any eutherian mammal. They also have a high level of variability in both active and resting T bs and, at least in cool temperatures in captivity, frequently employ both short- and long-term torpor. The use of heterothermy by captive animals is, however, generally reduced during gestation and lactation. We present data long-term T b recordings collected from free-ranging S. setosus over the course of two reproductive seasons. In general, reproductive females had slightly higher (~32 °C) and less variable T b, whereas non-reproductive females and males showed both a higher propensity for torpor as well as lower (~30.5 °C) and more variable rest-phase T bs. Torpor expression defined using traditional means (using a threshold or cut-off T b) was much lower than predicted based on the high degree of heterothermy in captive tenrecs. However, torpor defined in this manner is likely to be underestimated in habitats where ambient temperature is close to T b. Our results caution against inferring metabolic states from T b alone and lend support to the recent call to define torpor in free-ranging animals based on mechanistic and not descriptive variables. In addition, lower variability in T b observed during gestation and lactation confirms that homeothermy is essential for reproduction in this species and probably for basoendothermic mammals in general. The relatively low costs of maintaining homeothermy in a sub-tropical environment might help shed light on how homeothermy could have evolved incrementally from an ancestral heterothermic condition.

  15. Daily rhythms in glucose metabolism: suprachiasmatic nucleus output to peripheral tissue

    NARCIS (Netherlands)

    La Fleur, S. E.

    2003-01-01

    The body has developed several control mechanisms to maintain plasma glucose concentrations within strict boundaries. Within those physiological boundaries, a clear daily rhythm in plasma glucose concentrations is present; this rhythm depends on the biological clock, which is located in the

  16. Sleep deprivation and its impact on circadian rhythms and glucose metabolism

    NARCIS (Netherlands)

    Jha, P.K.

    2016-01-01

    The mammalian master pacemaker is located in the hypothalamic suprachiasmatic nucleus (SCN). The SCN generates rhythms of behavioural and metabolic processes throughout the body via both endocrine and neuronal outputs. For example, daily rhythms of sleep-wake, fasting-feeding, plasma glucose,

  17. Transcriptome analysis of Pseudomonas aeruginosa PAO1 grown at both body and elevated temperatures

    Directory of Open Access Journals (Sweden)

    Kok-Gan Chan

    2016-07-01

    Full Text Available Functional genomics research can give us valuable insights into bacterial gene function. RNA Sequencing (RNA-seq can generate information on transcript abundance in bacteria following abiotic stress treatments. In this study, we used the RNA-seq technique to study the transcriptomes of the opportunistic nosocomial pathogen Pseudomonas aeruginosa PAO1 following heat shock. Samples were grown at both the human body temperature (37 °C and an arbitrarily-selected temperature of 46 °C. In this work using RNA-seq, we identified 133 genes that are differentially expressed at 46 °C compared to the human body temperature. Our work identifies some key P. aeruginosa PAO1 genes whose products have importance in both environmental adaptation as well as in vivo infection in febrile hosts. More importantly, our transcriptomic results show that many genes are only expressed when subjected to heat shock. Because the RNA-seq can generate high throughput gene expression profiles, our work reveals many unanticipated genes with further work to be done exploring such genes products.

  18. Hilbert-Glass Transition: New Universality of Temperature-Tuned Many-Body Dynamical Quantum Criticality

    Directory of Open Access Journals (Sweden)

    David Pekker

    2014-03-01

    Full Text Available We study a new class of unconventional critical phenomena that is characterized by singularities only in dynamical quantities and has no thermodynamic signatures. One example of such a transition is the recently proposed many-body localization-delocalization transition, in which transport coefficients vanish at a critical temperature with no singularities in thermodynamic observables. Describing this purely dynamical quantum criticality is technically challenging as understanding the finite-temperature dynamics necessarily requires averaging over a large number of matrix elements between many-body eigenstates. Here, we develop a real-space renormalization group method for excited states that allows us to overcome this challenge in a large class of models. We characterize a specific example: the 1 D disordered transverse-field Ising model with generic interactions. While thermodynamic phase transitions are generally forbidden in this model, using the real-space renormalization group method for excited states we find a finite-temperature dynamical transition between two localized phases. The transition is characterized by nonanalyticities in the low-frequency heat conductivity and in the long-time (dynamic spin correlation function. The latter is a consequence of an up-down spin symmetry that results in the appearance of an Edwards-Anderson-like order parameter in one of the localized phases.

  19. The Effect of Tub Bathing on Body Temperature in Preterm Infants: Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Mahnaz Jabraeili

    2015-06-01

    Full Text Available Background: Bathing of a premature newborn is important in care giving, but due to inadequate evidences, infant caregivers are not sure about bathing being safe in terms of not causing hypothermia and are not systematically considered in the infants’ care giving programs. Aim: To determine the effect of tub bathing on body temperature of preterm infants”. Methods: This study is a randomized controlled clinical trial which was conducted in 1392 in neonatal unit of Al-zahra hospital. 118 preterm infants were randomly divided into intervention and control groups. The infants in the control group received routine skin care only. The intervention group was bathed three times every other day inside the bathtub. In both group, the infants’ body temperature was measured at the same times by the researcher. Data were analyzed with SPSS software version 14 using independent T-test, Chi-square and repeated measurements tests. Results: In both groups, boys outnumbered girls. At the time of inclusion, the infants' age was 5.8 ± 8.6 days and their weight was 320.6 ± 1660.0 grams. In both groups, the mean temperature of premature infants after bath was dropped in all three times. Which was statistically significant in the first and second baths (P

  20. Optimization of a pain model: effects of body temperature and anesthesia on bladder nociception in mice.

    Directory of Open Access Journals (Sweden)

    Katelyn E Sadler

    Full Text Available Interstitial cystitis/bladder pain syndrome (IC/BPS is a debilitating urological condition that is resistant to treatment and poorly understood. To determine novel molecular treatment targets and to elucidate the contribution of the nervous system to IC/BPS, many rodent bladder pain models have been developed. In this study we evaluated the effects of anesthesia induction and temperature variation in a mouse model of bladder pain known as urinary bladder distension (UBD. In this model compressed air is used to distend the bladder to distinct pressures while electrodes record the reflexive visceromotor response (VMR from the overlying abdominal muscle. Two isoflurane induction models are commonly used before UBD: a short method lasting approximately 30 minutes and a long method lasting approximately 90 minutes. Animals were anesthetized with one of the methods then put through three sets of graded bladder distensions. Distensions performed following the short anesthesia protocol were significantly different from one another despite identical testing parameters; this same effect was not observed when the long anesthesia protocol was used. In order to determine the effect of temperature on VMRs, animals were put through three graded distension sets at 37.5 (normal mouse body temperature, 35.5, and 33.5°C. Distensions performed at 33.5 and 35.5°C were significantly lower than those performed at 37.5°C. Additionally, Western blot analysis revealed significantly smaller increases in spinal levels of phosphorylated extracellular-signal regulated kinase 2 (pERK2 following bladder distension in animals whose body temperature was maintained at 33.5°C as opposed to 37.5°C. These results highlight the significance of the dynamic effects of anesthesia on pain-like changes and the importance of close monitoring of temperature while performing UBD. For successful interpretation of VMRs and translation to human disease, body temperature should be

  1. Optimization of a Pain Model: Effects of Body Temperature and Anesthesia on Bladder Nociception in Mice

    Science.gov (United States)

    Sadler, Katelyn E.; Stratton, Jarred M.; DeBerry, Jennifer J.; Kolber, Benedict J.

    2013-01-01

    Interstitial cystitis/bladder pain syndrome (IC/BPS) is a debilitating urological condition that is resistant to treatment and poorly understood. To determine novel molecular treatment targets and to elucidate the contribution of the nervous system to IC/BPS, many rodent bladder pain models have been developed. In this study we evaluated the effects of anesthesia induction and temperature variation in a mouse model of bladder pain known as urinary bladder distension (UBD). In this model compressed air is used to distend the bladder to distinct pressures while electrodes record the reflexive visceromotor response (VMR) from the overlying abdominal muscle. Two isoflurane induction models are commonly used before UBD: a short method lasting approximately 30 minutes and a long method lasting approximately 90 minutes. Animals were anesthetized with one of the methods then put through three sets of graded bladder distensions. Distensions performed following the short anesthesia protocol were significantly different from one another despite identical testing parameters; this same effect was not observed when the long anesthesia protocol was used. In order to determine the effect of temperature on VMRs, animals were put through three graded distension sets at 37.5 (normal mouse body temperature), 35.5, and 33.5°C. Distensions performed at 33.5 and 35.5°C were significantly lower than those performed at 37.5°C. Additionally, Western blot analysis revealed significantly smaller increases in spinal levels of phosphorylated extracellular-signal regulated kinase 2 (pERK2) following bladder distension in animals whose body temperature was maintained at 33.5°C as opposed to 37.5°C. These results highlight the significance of the dynamic effects of anesthesia on pain-like changes and the importance of close monitoring of temperature while performing UBD. For successful interpretation of VMRs and translation to human disease, body temperature should be maintained at 37.5

  2. Dissipative structures and biological rhythms

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    Goldbeter, Albert

    2017-10-01

    Sustained oscillations abound in biological systems. They occur at all levels of biological organization over a wide range of periods, from a fraction of a second to years, and with a variety of underlying mechanisms. They control major physiological functions, and their dysfunction is associated with a variety of physiological disorders. The goal of this review is (i) to give an overview of the main rhythms observed at the cellular and supracellular levels, (ii) to briefly describe how the study of biological rhythms unfolded in the course of time, in parallel with studies on chemical oscillations, (iii) to present the major roles of biological rhythms in the control of physiological functions, and (iv) the pathologies associated with the alteration, disappearance, or spurious occurrence of biological rhythms. Two tables present the main examples of cellular and supracellular rhythms ordered according to their period, and their role in physiology and pathophysiology. Among the rhythms discussed are neural and cardiac rhythms, metabolic oscillations such as those occurring in glycolysis in yeast, intracellular Ca++ oscillations, cyclic AMP oscillations in Dictyostelium amoebae, the segmentation clock that controls somitogenesis, pulsatile hormone secretion, circadian rhythms which occur in all eukaryotes and some bacteria with a period close to 24 h, the oscillatory dynamics of the enzymatic network driving the cell cycle, and oscillations in transcription factors such as NF-ΚB and tumor suppressors such as p53. Ilya Prigogine's concept of dissipative structures applies to temporal oscillations and allows us to unify within a common framework the various rhythms observed at different levels of biological organization, regardless of their period and underlying mechanism.

  3. Mitochondrial Impairment in Cerebrovascular Endothelial Cells is Involved in the Correlation between Body Temperature and Stroke Severity

    Science.gov (United States)

    Hu, Heng; Doll, Danielle N.; Sun, Jiahong; Lewis, Sara E.; Wimsatt, Jeffrey H.; Kessler, Matthew J.; Simpkins, James W.; Ren, Xuefang

    2016-01-01

    Stroke is the second leading cause of death worldwide. The prognostic influence of body temperature on acute stroke in patients has been recently reported; however, hypothermia has confounded experimental results in animal stroke models. This work aimed to investigate how body temperature could prognose stroke severity as well as reveal a possible mitochondrial mechanism in the association of body temperature and stroke severity. Lipopolysaccharide (LPS) compromises mitochondrial oxidative phosphorylation in cerebrovascular endothelial cells (CVECs) and worsens murine experimental stroke. In this study, we report that LPS (0.1 mg/kg) exacerbates stroke infarction and neurological deficits, in the mean time LPS causes temporary hypothermia in the hyperacute stage during 6 hours post-stroke. Lower body temperature is associated with worse infarction and higher neurological deficit score in the LPS-stroke study. However, warming of the LPS-stroke mice compromises animal survival. Furthermore, a high dose of LPS (2 mg/kg) worsens neurological deficits, but causes persistent severe hypothermia that conceals the LPS exacerbation of stroke infarction. Mitochondrial respiratory chain complex I inhibitor, rotenone, replicates the data profile of the LPS-stroke study. Moreover, we have confirmed that rotenone compromises mitochondrial oxidative phosphorylation in CVECs. Lastly, the pooled data analyses of a large sample size (n=353) demonstrate that stroke mice have lower body temperature compared to sham mice within 6 hours post-surgery; the body temperature is significantly correlated with stroke outcomes; linear regression shows that lower body temperature is significantly associated with higher neurological scores and larger infarct volume. We conclude that post-stroke body temperature predicts stroke severity and mitochondrial impairment in CVECs plays a pivotal role in this hypothermic response. These novel findings suggest that body temperature is prognostic for

  4. Heat production and body temperature during cooling and rewarming in overweight and lean men.

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    Claessens-van Ooijen, Anne M J; Westerterp, Klaas R; Wouters, Loek; Schoffelen, Paul F M; van Steenhoven, Anton A; van Marken Lichtenbelt, Wouter D

    2006-11-01

    To compare overweight and lean subjects with respect to thermogenesis and physiological insulation in response to mild cold and rewarming. Ten overweight men (mean BMI, 29.2 +/- 2.8 kg/m(2)) and 10 lean men (mean BMI, 21.1 +/- 2.0 kg/m(2)) were exposed to cold air for 1 hour, followed by 1 hour of rewarming. Body composition was determined by hydrodensitometry and deuterium dilution. Heat production and body temperatures were measured continuously by indirect calorimetry and thermistors, respectively. Muscle activity was recorded using electromyography. In both groups, heat production increased significantly during cooling (lean, p = 0.004; overweight, p = 0.006). The increase was larger in the lean group compared with the overweight group (p = 0.04). During rewarming, heat production returned to baseline in the overweight group and stayed higher compared with baseline in the lean group (p = 0.003). The difference in heat production between rewarming and baseline was larger in the lean (p = 0.01) than in the overweight subjects. Weighted body temperature of both groups decreased during cold exposure (lean, p = 0.002; overweight, p < 0.001) and did not return to baseline during rewarming. Overweight subjects showed a blunted mild cold-induced thermogenesis. The insulative cold response was not different among the groups. The energy-efficient response of the overweight subjects can have consequences for energy balance in the long term. The results support the concept of a dynamic heat regulation model instead of temperature regulation around a fixed set point.

  5. Elevational variation in body-temperature response to immune challenge in a lizard

    Directory of Open Access Journals (Sweden)

    Francisco Javier Zamora-Camacho

    2016-04-01

    Full Text Available Immunocompetence benefits animal fitness by combating pathogens, but also entails some costs. One of its main components is fever, which in ectotherms involves two main types of costs: energy expenditure and predation risk. Whenever those costs of fever outweigh its benefits, ectotherms are expected not to develop fever, or even to show hypothermia, reducing costs of thermoregulation and diverting the energy saved to other components of the immune system. Environmental thermal quality, and therefore the thermoregulation cost/benefit balance, varies geographically. Hence, we hypothesize that, in alpine habitats, immune-challenged ectotherms should show no thermal response, given that (1 hypothermia would be very costly, as the temporal window for reproduction is extremely small, and (2 fever would have a prohibitive cost, as heat acquisition is limited in such habitat. However, in temperate habitats, immune-challenged ectotherms might show a febrile response, due to lower cost/benefit balance as a consequence of a more suitable thermal environment. We tested this hypothesis in Psammodromus algirus lizards from Sierra Nevada (SE Spain, by testing body temperature preferred by alpine and non-alpine lizards, before and after activating their immune system with a typical innocuous pyrogen. Surprisingly, non-alpine lizards responded to immune challenge by decreasing preferential body-temperature, presumably allowing them to save energy and reduce exposure to predators. On the contrary, as predicted, immune-challenged alpine lizards maintained their body-temperature preferences. These results match with increased costs of no thermoregulation with elevation, due to the reduced window of time for reproduction in alpine environment.

  6. Synthetic cannabinoids found in "spice" products alter body temperature and cardiovascular parameters in conscious male rats.

    Science.gov (United States)

    Schindler, Charles W; Gramling, Benjamin R; Justinova, Zuzana; Thorndike, Eric B; Baumann, Michael H

    2017-10-01

    The misuse of synthetic cannabinoids is a persistent public health concern. Because these drugs target the same cannabinoid receptors as the active ingredient of marijuana, Δ 9 -tetrahydrocannabinol (THC), we compared the effects of synthetic cannabinoids and THC on body temperature and cardiovascular parameters. Biotelemetry transmitters for the measurement of body temperature or blood pressure (BP) were surgically implanted into separate groups of male rats. THC and the synthetic cannabinoids CP55,940, JWH-018, AM2201 and XLR-11 were injected s.c., and rats were placed into isolation cubicles for 3h. THC and synthetic cannabinoids produced dose-related decreases in body temperature that were most prominent in the final 2h of the session. The rank order of potency was CP55,940>AM2201=JWH-018>THC=XLR-11. The cannabinoid inverse agonist rimonabant antagonized the hypothermic effect of all compounds. Synthetic cannabinoids elevated BP in comparison to vehicle treatment during the first h of the session, while heart rate was unaffected. The rank order of potency for BP increases was similar to that seen for hypothermia. Hypertensive effects of CP55,940 and JWH-018 were not antagonized by rimonabant or the neutral antagonist AM4113. However, the BP responses to both drugs were antagonized by pretreatment with either the ganglionic blocker hexamethonium or the α 1 adrenergic antagonist prazosin. Our results show that synthetic cannabinoids produce hypothermia in rats by a mechanism involving cannabinoid receptors, while they increase BP by a mechanism independent of these sites. The hypertensive effect appears to involve central sympathetic outflow. Published by Elsevier B.V.

  7. Specific dynamic action of ambystomatid salamanders and the effects of meal size, meal type, and body temperature.

    Science.gov (United States)

    Secor, Stephen M; Boehm, Matthew

    2006-01-01

    The past decade has witnessed a dramatic increase in studies of amphibian and reptile specific dynamic action (SDA). These studies have demonstrated that SDA, the summed energy expended on meal digestion and assimilation, is affected significantly by meal size, meal type, and body size and to some extent by body temperature. While much of this attention has been directed at anuran and reptile SDA, we investigated the effects of meal size, meal type, and body temperature on the postprandial metabolic responses and the SDA of the tiger salamander (Ambystoma tigrinum tigrinum). We also compared the SDA responses among six species of Ambystoma salamanders representing the breadth of Ambystoma phylogeny. Postprandial peaks in VO(2) and VO(2), duration of elevated metabolism, and SDA of tiger salamanders increased with the size of cricket meals (2.5%-12.5% of body mass). For A. tigrinum, as for other ectotherms, a doubling of meal size results in an approximate doubling of SDA, a function of equal increases in peak VO(2) and duration. For nine meal types of equivalent size (5% of body mass), the digestion of hard-bodied prey (crickets, superworms, mealworms, beetles) generated larger SDA responses than the digestion of soft-bodied prey (redworms, beetle larvae). Body temperature affected the profile of postprandial metabolism, increasing the peak and shortening the duration of the profile as body temperature increased. SDA was equivalent among three body temperatures (20 degrees, 25 degrees, and 30 degrees C) but decreased significantly at 15 degrees C. Comparatively, the postprandial metabolic responses and SDA of Ambystoma jeffersonianum, Ambystoma maculatum, Ambystoma opacum, Ambystoma talpoideum, Ambystoma texanum, and the conspecific Ambystoma tigrinum mavortium digesting cricket meals that were 5% of their body mass were similar (independent of body mass) to those of A. t. tigrinum. Among the six species, standard metabolic rate, peak postprandial VO(2), and SDA

  8. Evaluation of the relationship between motion sickness symptomatology and blood pressure, heart rate, and body temperature

    Science.gov (United States)

    Graybiel, A.; Lackner, J. R.

    1980-01-01

    This study investigated the relationship between the development of symptoms of motion sickness and changes in blood pressure, heart rate, and body temperature. Twelve subjects were each evaluated four times using the vestibular-visual interaction test (Graybiel and Lackner, 1980). The results were analyzed both within and across individual subjects. Neither a systematic group nor consistent individual relationship was found between the physiological parameters and the appearance of symptoms of motion sickness. These findings suggest that biofeedback control of the physiological variables studied is not likely to prevent the expression of motion sickness symptomatology.

  9. The effect of direct heating and cooling of heat regulation centers on body temperature

    Science.gov (United States)

    Barbour, H. G.

    1978-01-01

    Experiments were done on 28 rabbits in which puncture instruments were left in the brain for 1-2 days until the calori-puncture hyperthermia had passed and the body temperature was again normal. The instrument remaining in the brain was then used as a galvanic electrode and a second fever was produced, this time due to the electrical stimulus. It was concluded that heat is a centrally acting antipyretic and that cold is a centrally acting stimulus which produces hyperpyrexia cold-induced fever.

  10. Influence of heating rate and temperature firing on the properties of bodies of red ceramic

    International Nuclear Information System (INIS)

    Silva, B.J. da; Goncalves, W.P.; Cartaxo, J.M.; Macedo, R.S.; Neves, G.A.; Santana, L.N.L.; Menezes, R.R.

    2011-01-01

    In the red ceramic industry, the firing is one of the main stages of the production process. There are two heating rates prevailing at this stage: the slow (traditional ceramics) and fast. The slow rate more used in Brazil, is considered delayed. This study aims to evaluate the influence of particle size and chemical composition of three mixture of clay, used in the manufacture of red ceramic products and to study the influence of the firing temperature on their technological properties. When subjected to heating rates slow and fast. Initially, the mixtures were characterized subsequently were extruded, dried and subjected to firing at temperatures of 900 and 1000 ° C with heating rates of 5, 20 and 30 °C/min. The results indicated that the chemical composition and particle size influenced significantly the technological properties and that the bodies obtained with the paste that had lower levels of flux showed better stability. (author)

  11. New standards for devices used for the measurement of human body temperature.

    Science.gov (United States)

    Ring, E F J; McEvoy, H; Jung, A; Zuber, J; Machin, G

    2010-05-01

    Significant changes in recording of human body temperature have been taking place worldwide in recent years. The clinical thermometer introduced in the mid-19th century by Wunderlich has been replaced by digital thermometers or radiometer devices for recording tympanic membrane temperature. More recently the use of infrared thermal imaging for fever screening has become more widespread following the SARS infection, and particularly during the pandemic H1N1 outbreak. Important new standards that have now reached international acceptance will affect clinical and fever screening applications. This paper draws attention to these new standard documents. They are designed to improve the standardization of both performance and practical use of these key techniques in clinical medicine, especially necessary in a pandemic influenza situation.

  12. Drosophila DH31 Neuropeptide and PDF Receptor Regulate Night-Onset Temperature Preference.

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    Goda, Tadahiro; Tang, Xin; Umezaki, Yujiro; Chu, Michelle L; Hamada, Fumika N

    2016-11-16

    Body temperature exhibits rhythmic fluctuations over a 24 h period (Refinetti and Menaker, 1992) and decreases during the night, which is associated with sleep initiation (Gilbert et al., 2004; Kräuchi, 2007a,b). However, the underlying mechanism of this temperature decrease is largely unknown. We have previously shown that Drosophila exhibit a daily temperature preference rhythm (TPR), in which their preferred temperatures increase during the daytime and then decrease at the transition from day to night (night-onset) (Kaneko et al., 2012). Because Drosophila are small ectotherms, their body temperature is very close to that of the ambient temperature (Stevenson, 1985), suggesting that their TPR generates their body temperature rhythm. Here, we demonstrate that the neuropeptide diuretic hormone 31 (DH31) and pigment-dispersing factor receptor (PDFR) contribute to regulate the preferred temperature decrease at night-onset. We show that PDFR and tethered-DH31 expression in dorsal neurons 2 (DN2s) restore the preferred temperature decrease at night-onset, suggesting that DH31 acts on PDFR in DN2s. Notably, we previously showed that the molecular clock in DN2s is important for TPR. Although PDF (another ligand of PDFR) is a critical factor for locomotor activity rhythms, Pdf mutants exhibit normal preferred temperature decreases at night-onset. This suggests that DH31-PDFR signaling specifically regulates a preferred temperature decrease at night-onset. Thus, we propose that night-onset TPR and locomotor activity rhythms are differentially controlled not only by clock neurons but also by neuropeptide signaling in the brain. Body temperature rhythm (BTR) is fundamental for the maintenance of functions essential for homeostasis, such as generating metabolic energy and sleep. One major unsolved question is how body temperature decreases dramatically during the night. Previously, we demonstrated that a BTR-like mechanism, referred to as temperature preference rhythm (TPR

  13. Effects of meal size, meal type, body temperature, and body size on the specific dynamic action of the marine toad, Bufo marinus.

    Science.gov (United States)

    Secor, Stephen M; Faulkner, Angela C

    2002-01-01

    Specific dynamic action (SDA), the accumulated energy expended on all physiological processes associated with meal digestion, is strongly influenced by features of both the meal and the organism. We assessed the effects of meal size, meal type, body temperature, and body size on the postprandial metabolic response and calculated SDA of the marine toad, Bufo marinus. Peak postprandial rates of O(2) consumption (.V(O2)) and CO(2) production (.V(CO2)) and SDA increased with meal size (5%-20% of body mass). Postprandial metabolism was impacted by meal type; the digestion of hard-bodied superworms (Zophobas larva) and crickets was more costly than the digestion of soft-bodied earthworms and juvenile rats. An increase in body temperature (from 20 degrees to 35 degrees C) altered the postprandial metabolic profile, decreasing its duration and increasing its magnitude, but did not effect SDA, with the cost of meal digestion remaining constant across body temperatures. Allometric mass exponents were 0.69 for standard metabolic rate, 0.85 for peak postprandial .V(O2), and 1.02 for SDA; therefore, the factorial scope of peak postprandial .V(O2) increased with body mass. The mass of nutritive organs (stomach, liver, intestines, and kidneys) accounted for 38% and 20% of the variation in peak postprandial .V(O2) and SDA, respectively. Toads forced to exercise experienced 25-fold increases in .V(O2) much greater than the 5.5-fold increase experience during digestion. Controlling for meal size, meal type, and body temperature, the specific dynamic responses of B. marinus are similar to those of the congeneric Bufo alvarius, Bufo boreas, Bufo terrestris, and Bufo woodhouseii.

  14. Critical temperature of liquid-gas phase transition for hot nuclear matter and three-body force effect

    International Nuclear Information System (INIS)

    Zuo Wei; Lu Guangcheng; Li Zenghua; Luo Peiyan; Chinese Academy of Sciences, Beijing

    2005-01-01

    The finite temperature Brueckner-Hartree-Fock (FTBHF) approach is extended by introducing a microscopic three-body force. Within the extended approach, the three-body force effects on the equation of state of hot nuclear matter and its temperature dependence have been investigated. The critical properties of the liquid-gas phase transition of hot nuclear matter have been calculated. It is shown that the three-body force provides a repulsive contribution to the equation of state of hot nuclear matter. The repulsive effect of the three-body force becomes more pronounced as the density and temperature increase and consequently inclusion of the three-body force contribution in the calculation reduces the predicted critical temperature from about 16 MeV to about 13 MeV. By separating the contribution originated from the 2σ-exchange process coupled to the virtual excitation of a nucleon-antinucleon pair from the full three-body force, the connection between the three-body force effect and the relativistic correction from the Dirac-Brueckner-Hartree-Fock has been explored. It turns out that the contribution of the 2σ-N(N-bar) part is more repulsive than that of the full three-body force and the calculated critical temperature is about 11 MeV if only the 2σ-N(N-bar) component of the three-body force is included which is lower than the value obtained in the case of including the full three-body force and is close to the value predicted by the Dirac-Brueckner-Hartree-Fock (DBHF) approach. Our result provides a reasonable explanation for the discrepancy between the values of critical temperature predicted from the FTBHF approach including the three-body force and the DBHF approach. (authors)

  15. Transient receptor potential melastatin 8 (TRPM8) channels are involved in body temperature regulation.

    Science.gov (United States)

    Gavva, Narender R; Davis, Carl; Lehto, Sonya G; Rao, Sara; Wang, Weiya; Zhu, Dawn X D

    2012-05-09

    Transient receptor potential cation channel subfamily M member 8 (TRPM8) is activated by cold temperature in vitro and has been demonstrated to act as a 'cold temperature sensor' in vivo. Although it is known that agonists of this 'cold temperature sensor', such as menthol and icilin, cause a transient increase in body temperature (Tb), it is not known if TRPM8 plays a role in Tb regulation. Since TRPM8 has been considered as a potential target for chronic pain therapeutics, we have investigated the role of TRPM8 in Tb regulation. We characterized five chemically distinct compounds (AMG0635, AMG2850, AMG8788, AMG9678, and Compound 496) as potent and selective antagonists of TRPM8 and tested their effects on Tb in rats and mice implanted with radiotelemetry probes. All five antagonists used in the study caused a transient decrease in Tb (maximum decrease of 0.98°C). Since thermoregulation is a homeostatic process that maintains Tb about 37°C, we further evaluated whether repeated administration of an antagonist attenuated the decrease in Tb. Indeed, repeated daily administration of AMG9678 for four consecutive days showed a reduction in the magnitude of the Tb decrease Day 2 onwards. The data reported here demonstrate that TRPM8 channels play a role in Tb regulation. Further, a reduction of magnitude in Tb decrease after repeated dosing of an antagonist suggests that TRPM8's role in Tb maintenance may not pose an issue for developing TRPM8 antagonists as therapeutics.

  16. Antipyretic Therapy in Critically Ill Patients with Sepsis: An Interaction with Body Temperature

    Science.gov (United States)

    Zhang, Zhongheng; Chen, Lin; Ni, Hongying

    2015-01-01

    Background and Objective The effect of antipyretic therapy on mortality in patients with sepsis remains undetermined. The present study aimed to investigate the role of antipyretic therapy in ICU patients with sepsis by using a large clinical database. Methods The multiparameter intelligent monitoring in intensive care II (MIMIC- II) database was employed for the study. Adult patients with sepsis were included for analysis. Antipyretic therapy included antipyretic medication and external cooling. Multivariable model with interaction terms were employed to explore the association of antipyretic therapy and mortality risk. Main Results A total of 15,268 patients fulfilled inclusion criteria and were included in the study. In multivariable model by treating temperature as a continuous variable, there was significant interaction between antipyretic therapy and the maximum temperature (Tmax). While antipyretic therapy had no significant effect on mortality in low temperature quintiles, antipyretic therapy was associated with increased risk of death in the quintile with body temperature >39°C (OR: 1.29, 95% CI: 1.04–1.61). Conclusion Our study shows that there is no beneficial effect on reducing mortality risk with the use of antipyretic therapy in ICU patients with sepsis. External cooling may even be harmful in patients with sepsis. PMID:25822614

  17. Too hot to sleep? Sleep behaviour and surface body temperature of Wahlberg's Epauletted Fruit Bat.

    Science.gov (United States)

    Downs, Colleen T; Awuah, Adwoa; Jordaan, Maryna; Magagula, Londiwe; Mkhize, Truth; Paine, Christine; Raymond-Bourret, Esmaella; Hart, Lorinda A

    2015-01-01

    The significance of sleep and factors that affect it have been well documented, however, in light of global climate change the effect of temperature on sleep patterns has only recently gained attention. Unlike many mammals, bats (order: Chiroptera) are nocturnal and little is known about their sleep and the effects of ambient temperature (Ta) on their sleep. Consequently we investigated seasonal temperature effects on sleep behaviour and surface body temperature of free-ranging Wahlberg's epauletted fruit bat, Epomophorus wahlbergi, at a tree roost. Sleep behaviours of E. wahlbergi were recorded, including: sleep duration and sleep incidences (i.e. one eye open and both eyes closed). Sleep differed significantly across all the individuals in terms of sleep duration and sleep incidences. Individuals generally spent more time awake than sleeping. The percentage of each day bats spent asleep was significantly higher during winter (27.6%), compared with summer (15.6%). In summer, 20.7% of the sleeping bats used one eye open sleep, and this is possibly the first evidence of one-eye-sleep in non-marine mammals. Sleep duration decreased with extreme heat as bats spent significantly more time trying to cool by licking their fur, spreading their wings and panting. Skin temperatures of E. wahlbergi were significantly higher when Ta was ≥35°C and no bats slept at these high temperatures. Consequently extremely hot days negatively impact roosting fruit bats, as they were forced to be awake to cool themselves. This has implications for these bats given predicted climate change scenarios.

  18. Elevated body temperature is linked to fatigue in an Italian sample of relapsing-remitting multiple sclerosis patients.

    Science.gov (United States)

    Leavitt, V M; De Meo, E; Riccitelli, G; Rocca, M A; Comi, G; Filippi, M; Sumowski, J F

    2015-11-01

    Elevated body temperature was recently reported for the first time in patients with relapsing-remitting multiple sclerosis (RRMS) relative to healthy controls. In addition, warmer body temperature was associated with worse fatigue. These findings are highly novel, may indicate a novel pathophysiology for MS fatigue, and therefore warrant replication in a geographically separate sample. Here, we investigated body temperature and its association to fatigue in an Italian sample of 44 RRMS patients and 44 age- and sex-matched healthy controls. Consistent with our original report, we found elevated body temperature in the RRMS sample compared to healthy controls. Warmer body temperature was associated with worse fatigue, thereby supporting the notion of endogenous temperature elevations in patients with RRMS as a novel pathophysiological factor underlying fatigue. Our findings highlight a paradigm shift in our understanding of the effect of heat in RRMS, from exogenous (i.e., Uhthoff's phenomenon) to endogenous. Although randomized controlled trials of cooling treatments (i.e., aspirin, cooling garments) to reduce fatigue in RRMS have been successful, consideration of endogenously elevated body temperature as the underlying target will enhance our development of novel treatments.

  19. A simple and inexpensive system for controlling body temperature in small animal experiments using MRI and the effect of body temperature on the hepatic kinetics of Gd-EOB-DTPA.

    Science.gov (United States)

    Murase, Kenya; Assanai, Purapan; Takata, Hiroshige; Saito, Shigeyoshi; Nishiura, Motoko

    2013-12-01

    The purpose of this study was to develop a simple and inexpensive system for controlling body temperature in small animal experiments using magnetic resonance imaging (MRI) and to investigate the effect of body temperature on the kinetic behavior of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) in the liver. In our temperature-control system, body temperature was controlled using a feedback-regulated heated or cooled air flow generated by two Futon dryers. The switches of the two Futon dryers were controlled using a digital temperature controller, in which the rectal temperature of a mouse measured by an optical fiber thermometer was used as the input. In experimental studies, male ICR mice aged 8weeks old were used and allocated into 5 groups (39-, 36-, 33-, 30-, and 27-degree groups, n=10), in which the body temperature was maintained at 39 °C, 36 °C, 33 °C, 30 °C, and 27 °C, respectively, using our system. The dynamic contrast-enhanced MRI (DCE-MRI) data were acquired with an MRI system for animal experiments equipped with a 1.5-Tesla permanent magnet, for approximately 43min, after the injection of Gd-EOB-DTPA into the tail vein. After correction of the image shift due to the temperature-dependent drift of the Larmor frequency using the gradient-based image registration method with robust estimation of displacement parameters, the kinetic behavior of Gd-EOB-DTPA was analyzed using an empirical mathematical model. With the use of this approach, the upper limit of the relative enhancement (A), the rates of contrast uptake (α) and washout (β), the parameter related to the slope of early uptake (q), the area under the curve (AUC), the maximum relative enhancement (REmax), the time to REmax (Tmax), and the elimination half-life of the contrast agent (T1/2) were calculated. The body temperature of mice could be controlled well by use of our system. Although there were no significant differences in α, AUC, and q among groups, there

  20. Circadian Rhythm Management System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The value of measuring sleep-wake cycles is significantly enhanced by measuring other physiological signals that depend on circadian rhythms (such as heart rate and...

  1. COMBINATION OF COLD PACK, WATER SPRAY, AND FAN COOLING ON BODY TEMPERATURE REDUCTION AND LEVEL OF SUCCESS TO REACH NORMAL TEMPERATURE IN CRITICALLY ILL PATIENTS WITH HYPERTHERMIA

    Directory of Open Access Journals (Sweden)

    Nur Eka Dzulfaijah

    2017-12-01

    Full Text Available Objective: To examine the effect of the combination of cold pack, water spray, and fan cooling on body temperature reduction and level of success to reach normal temperature in critically ill patients with hyperthermia. Methods: This was a randomized control trial (RCT with pretest postest control group design and repeated measurement, conducted on December 2016 – January 2017. There were 32 respondents selected using total sampling, with 16 respondents randomly assigned in the experiment and control group. A digital thermometer was used to measure hyperthermia. Paired t-test, Repeated Anova with post hoc, and Mann Whitney were used for data analysis. Results: Findings showed that the mean of body temperature in the experiment group in pretest was 38.762oC and decreased to 37.3oC after given intervention for 60 minutes. The mean difference of body temperature was 1.4625, with p-value 0.000 (<0.05. In control group, the mean of body temperature in pretest was 38.669oC and decreased to 38.188oC given intervention for 60 minutes. The mean difference of body temperature was 0.4812, with p-value 0.000 (<0.05. Conclusion: There was a significant effect of the combination of cold pack, water spray, and fan cooling on body temperature reduction and level of success to reach normal temperature in critically ill patients with hyperthermia. This combination is more effective than water compress alone.

  2. Effects of ambient temperature on adaptive thermogenesis during maintenance of reduced body weight in mice

    Science.gov (United States)

    Ravussin, Yann; LeDuc, Charles A.; Watanabe, Kazuhisa

    2012-01-01

    We showed previously that, at ambient room temperature (22°C), mice maintained at 20% below their initial body weight by calorie restriction expend energy at a rate below that which can be accounted for by the decrease of fat and fat-free mass. Food-restricted rodents may become torpid at subthermoneutral temperatures, a possible confounding factor when using mice as human models in obesity research. We examined the bioenergetic, hormonal, and behavioral responses to maintenance of a 20% body weight reduction in singly housed C57BL/6J +/+ and Lepob mice housed at both 22°C and 30°C. Weight-reduced high-fat-fed diet mice (HFD-WR) showed similar quantitative reductions in energy expenditure—adjusted for body mass and composition—at both 22°C and 30°C: −1.4 kcal/24 h and −1.6 kcal/24 h below predicted, respectively, and neither group entered torpor. In contrast, weight-reduced Lepob mice (OB-WR) housed at 22°C became torpid in the late lights-off period (0200–0500) but did not when housed at 30°C. These studies indicate that mice with an intact leptin axis display similar decreases in “absolute” energy expenditure in response to weight reduction at both 22°C and 30°C ambient temperature. More importantly, the “percent” decrease in total energy expenditure observed in the HFD-WR compared with AL mice is much greater at 30°C (−19%) than at 22°C (−10%). Basal energy expenditure demands are ∼45% lower in mice housed at 30°C vs. 22°C, since the mice housed at thermoneutrality do not allocate extra energy for heat production. The higher total energy expenditure of mice housed at 22°C due to these increased thermogenic demands may mask physiologically relevant changes in energy expenditure showing that ambient temperature must be carefully considered when quantifying energy metabolism in both rodents and humans. PMID:22761182

  3. Short communication: calf body temperature following chemical disbudding with sedation: effects of milk allowance and supplemental heat.

    Science.gov (United States)

    Vasseur, E; Rushen, J; de Passillé, A M

    2014-01-01

    The use of caustic paste combined with a sedative is one of the least painful methods for disbudding. It is recommended to disbud at as early as 5d of age. However, the sedative xylazine reportedly causes a decrease in core temperature. Furthermore, young calves do not thermoregulate efficiently. We investigated the effects of disbudding calves at 5d of age using caustic paste and xylazine sedation on body temperature, activity, and milk intake of 46 individually housed 5-d-old calves in a 2×2 factorial design, with milk fed at 4.5L/d (low-fed calves) versus 9L/d (high-fed calves), with or without a heat lamp. Body temperature, calf activity (standing time), and barn temperature were monitored continuously using automatic data loggers on the day of, before the day of, and the day after disbudding. All calves were injected intramuscularly with 0.25mL of 2mg/mL xylazine 20min before disbudding (dose: 0.12±0.003mL/kg of BW). We found that the body temperature of 5-d-old calves decreased immediately after the injection of the sedative xylazine. The body temperature of calves decreased 0.9±0.09°C and it took 3.8±0.32h to climb back to the preinjection body temperature. Calves that were fed the lower amount of milk, received a higher dose of xylazine (mL/kg BW), or were disbudded in a colder environment were more affected by body temperature variations (lower and longest decrease in body temperature and higher magnitude). Calf activity recovery followed the pattern of body temperature recovery. Milk allowance and supplemental heat did not help enhance recovery during the 6h following the procedure. The disbudding procedure did not affect milk intake but calves with less body temperature decrease or kept in a warmer environment drank more milk following disbudding. Low-fed calves were overall more affected by the procedure than high-fed calves during the disbudding day and the following day (greater decrease in body temperature and drank less in the colder

  4. Assessment of axillary temperature for the evaluation of normal body temperature of healthy young adults at rest in a thermoneutral environment.

    Science.gov (United States)

    Marui, Shuri; Misawa, Ayaka; Tanaka, Yuki; Nagashima, Kei

    2017-02-22

    The aims of this study were to (1) evaluate whether recently introduced methods of measuring axillary temperature are reliable, (2) examine if individuals know their baseline body temperature based on an actual measurement, and (3) assess the factors affecting axillary temperature and reevaluate the meaning of the axillary temperature. Subjects were healthy young men and women (n = 76 and n = 65, respectively). Three measurements were obtained: (1) axillary temperature using a digital thermometer in a predictive mode requiring 10 s (T ax-10 s ), (2) axillary temperature using a digital thermometer in a standard mode requiring 10 min (T ax-10 min ), and (3) tympanic membrane temperature continuously measured by infrared thermometry (T ty ). The subjects answered questions about eating and exercise habits, sleep and menstrual cycles, and thermoregulation and reported what they believed their regular body temperature to be (T reg ). T reg , T ax-10 s , T ax-10 min , and T ty were 36.2 ± 0.4, 36.4 ± 0.5, 36.5 ± 0.4, and 36.8 ± 0.3 °C (mean ± SD), respectively. There were correlations between T ty and T ax-10 min , T ty and T ax-10 s , and T ax-10 min and T ax-10 s (r = .62, r = .46, and r = .59, respectively, P body mass indices and irregular menstrual cycles. Modern devices for measuring axillary temperature may have changed the range of body temperature that is recognized as normal. Core body temperature variations estimated by tympanic measurements were smaller than those estimated by axillary measurements. This variation of axillary temperature may be due to changes in the measurement methods introduced by modern devices and techniques. However, axillary temperature values correlated well with those of tympanic measurements, suggesting that the technique may reliably report an individual's state of health. It is important for individuals to know their baseline axillary temperature to evaluate subsequent

  5. Zero-Heat-Flux Thermometry for Non-Invasive Measurement of Core Body Temperature in Pigs.

    Science.gov (United States)

    Guschlbauer, Maria; Maul, Alexandra C; Yan, Xiaowei; Herff, Holger; Annecke, Thorsten; Sterner-Kock, Anja; Böttiger, Bernd W; Schroeder, Daniel C

    2016-01-01

    Hypothermia is a severe, unpleasant side effect during general anesthesia. Thus, temperature surveillance is a prerequisite in general anesthesia settings during experimental surgeries. The gold standard to measure the core body temperature (Tcore) is placement of a Swan-Ganz catheter in the pulmonary artery, which is a highly invasive procedure. Therefore, Tcore is commonly examined in the urine bladder and rectum. However, these procedures are known for their inaccuracy and delayed record of temperatures. Zero-heat-flux (ZHF) thermometry is an alternative, non-invasive method quantifying Tcore in human patients by applying a thermosensoric patch to the lateral forehead. Since the porcine cranial anatomy is different to the human's, the optimal location of the patch remains unclear to date. The aim was to compare three different patch locations of ZHF thermometry in a porcine hypothermia model. Hypothermia (33.0 °C Tcore) was conducted in 11 anesthetized female pigs (26-30 kg). Tcore was measured continuously by an invasive Swan-Ganz catheter in the pulmonary artery (Tpulm). A ZHF thermometry device was mounted on three different defined locations. The smallest average difference between Tpulm and TZHF during stable temperatures was 0.21 ± 0.16 °C at location A, where the patch was placed directly behind the eye. Also during rapidly changing temperatures location A showed the smallest bias with 0.48 ± 0.29 °C. Location A provided the most reliable data for Tcore. Therefore, the ZHF thermometry patch should be placed directly behind the left temporal corner of the eye to provide a non-invasive method for accurate measurement of Tcore in pigs.

  6. Is higher body temperature beneficial in ischemic stroke patients with normal admission CT angiography of the cerebral arteries?

    Science.gov (United States)

    Kvistad, Christopher Elnan; Khanevski, Andrej; Nacu, Aliona; Thomassen, Lars; Waje-Andreassen, Ulrike; Naess, Halvor

    2014-01-01

    Low body temperature is considered beneficial in ischemic stroke due to neuroprotective mechanisms, yet some studies suggest that higher temperatures may improve clot lysis and outcomes in stroke patients treated with tissue plasminogen activator (tPA). The effect of increased body temperature in stroke patients treated with tPA and with normal computed tomography angiography (CTA) on admission is unknown. We hypothesized a beneficial effect of higher body temperature in the absence of visible clots on CTA, possibly due to enhanced lysis of small, peripheral clots. Patients with ischemic stroke admitted to our Stroke Unit between February 2006 and April 2013 were prospectively registered in a database (Bergen NORSTROKE Registry). Ischemic stroke patients treated with tPA with normal CTA of the cerebral arteries were included. Outcomes were assessed by the modified Rankin Scale (mRS) after 1 week. An excellent outcome was defined as mRS=0, and a favorable outcome as mRS=0-1. A total of 172 patients were included, of which 48 (27.9%) had an admission body temperature ≥37.0°C, and 124 (72.1%) had a body temperature temperature ≥37.0°C was independently associated with excellent outcomes (odds ratio [OR]: 2.8; 95% confidence interval [CI]: 1.24-6.46; P=0.014) and favorable outcomes (OR: 2.8; 95% CI: 1.13-4.98; P=0.015) when adjusted for confounders. We found an association between higher admission body temperature and improved outcome in tPA-treated stroke patients with normal admission CTA of the cerebral arteries. This may sug