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Results 451 - 500 of 1144
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Butler Patrick J - - 2002
To enable the use of heart rate (fH) for estimating field metabolic rate (FMR) in free-ranging Galapagos marine iguanas Amblyrhynchus cristatus, we determined the relationships between fH and mass-specific rate of oxygen consumption (sVO2) in seven iguanas before and during exercise on a treadmill and during the post-exercise period. The ...
Nybo Lars - - 2002
The development of hyperthermia during prolonged exercise in humans is associated with various changes in the brain, but it is not known whether the cerebral metabolism or the global cerebral blood flow (gCBF) is affected. Eight endurance-trained subjects completed two exercise bouts on a cycle ergometer. The gCBF and cerebral ...
Binzoni Tiziano - - 2002
The present work was aimed at measuring intramuscular oxygen consumption (O(2)) as a function of temperature (T), in human forearm, during rest and aerobic isometric exercise (4% of the maximal voluntary contraction, MVC). Based upon results from in vitro experiments performed on isolated mitochondria of animal species, it was hypothesised ...
Yamazaki Fumio - - 2002
PURPOSE: To test whether vasomotor responses to dynamic exercise differ in glabrous and nonglabrous human skin, we determined the phase response and amplitude response of cutaneous vascular conductance in the forearm (CVCforearm), dorsal hand (CVCdorsal hand), and palm (CVCpalm) to sinusoidal exercise. METHODS: Nine healthy subjects exercised on a cycle ...
Layden Joseph D - - 2002
PURPOSE: The influence of cold air exposure on fuel utilization during prolonged cycle exercise was investigated. METHODS: Nine male subjects cycled for 90 min in ambient temperatures of -10 degrees C, 0 degrees C, 10 degrees C, and 20 degrees C. External work performed between conditions was constant. Mean oxygen ...
Lee Stuart M C - - 2002
Two potential mechanisms, reduced skin blood flow (SBF) and sweating rate (SR), may be responsible for elevated intestinal temperature (T(in)) during exercise after bed rest and spaceflight. Seven men underwent 13 days of 6 degrees head-down bed rest. Pre- and post-bed rest, subjects completed supine submaximal cycle ergometry (20 min ...
Wang Yuan - - 2002
Lesions of the lateral parabrachial nucleus (lPBN) disrupt acquisition of LiCl-induced conditioned taste avoidance. Animals with lesions in this area also fail to exhibit taste neophobia. This raises the possibility that an inability of rats to recognize the taste solution as novel contributes to the deficit in taste avoidance learning. ...
Kim K H - - 2002
Optical spectroscopy was used to investigate the optical gap ( 2 Delta) due to charge ordering (CO) and related pseudogap developments with x and temperature ( T) in La(1-x)Ca(x)MnO(3) ( 0.48< or =x< or =0.67). Surprisingly, we found 2 Delta/k(B)T(CO) is as large as 30 for x approximately 0.5, and ...
Lang Manfred - - 2002
Perioperative-induced hypothermia is a common means of reducing ischemic injury in neurosurgical procedures and cardiac surgery, and it may occur accidentally. Somatosensory evoked potentials (SSEPs) are used frequently for neurophysiologic monitoring of these procedures. The effects of hypothermia on SSEPs have been studied widely in humans with cardiopulmonary bypass (CPB) ...
Ferguson Richard A - - 2002
The effect of elevated human muscle temperature on energy turnover was investigated during cycling exercise (at 85 % of (VO(2)max)) at a contraction frequency of 60 revs min(-1). Muscle temperature was passively elevated prior to exercise by immersion of the legs in a hot water bath (42 degrees C). During ...
Urbaneja Alberto - - 2002
Cirrospilus vittatus is a generalist parasitoid detected on the invading Phyllocnistis citrella 1 yr after the introduction of this pest into Spain in 1993. In this study, the influence of temperature on parasitoid development, survival, and some selected life history parameters was determined. Development times shortened as the temperature increased ...
Gregson W A - - 2002
To determine the effects of pre-warming on the human metabolic and thermoregulatory responses to prolonged steady-rate exercise in moderate ambient temperatures and relative humidities [means (SD) 21.7 (2.1) degrees C and 36.7 (5.4)%, respectively], six healthy men each ran at a steady-rate (70% maximal oxygen uptake) on a treadmill until ...
Laird I S - - 2002
Twelve New Zealand workers from a range of occupations were studied to investigate the effect of wearing air-filtering respiratory protection on heart rate (HR) and facial skin temperature (Tlip and Tcheek) whilst working. All variables were measured continuously during simulated and actual work. The former allowed physiological measurements to be ...
Gracenea M - - 2002
Factors influencing the transmission of Cryptosporidium in primates and herbivores housed at the Barcelona zoo have been analyzed. The relationship between continuous and discontinuous oocyst shedding, both animal housing conditions and abiotic factors (seasonality, humidity, temperature) was examined to explain the epizootiology of the protozoan. Thirty six fecal samples from ...
Kolkhorst Fred W - - 2002
Our interest was to quantify the role of sweat gland activation on the maintenance of skin temperature during mild exercise in the heat. Seven days of tap-water iontophoresis decreased the number of active sweat glands by 72% which significantly increased forearm skin temperature and blood flow during mild exercise (70 ...
Kenny Glen P - - 2002
On 2 separate days, nine volunteers aged 23.8 (2.0) years performed 15-min bouts of treadmill running in a temperature-controlled chamber at 29 degrees C at a power output that elicited either 70% (moderate) or 93% (intense) of maximum oxygen consumption. Exercise was followed by a 45-min recovery period. End-exercise esophageal ...
Laburn Helen P - - 2002
We exposed Dorper-cross ewes at approximately 120-135 days of gestation to a hot (40 degrees C, 60% relative humidity) and a cold (4 degrees C, 90% relative humidity) environment and to treadmill exercise (2.1 km/h, 5 degrees gradient) and measured fetal lamb and ewe body temperatures using previously implanted abdominal ...
Aoki Ken - - 2002
To investigate the influence of nonthermal factors in the time-of-day effect on the sweating response to maintained static exercise, eight healthy male subjects performed handgrip exercise at 20%, 35% and 50% maximal voluntary contraction (MVC) for 60 s at 0600 hours (morning) and at 1800 hours (evening). Oesophageal temperature ( ...
Youngstedt Shawn D - - 2002
In a within-subjects (n = 18), counterbalanced design, the circadian phase-shifting effects of 3 h of 1) bright light (3,000 lx) alone 2) and bright light combined with vigorous exercise were compared. For each treatment, volunteers spent 3 nights and 2 days in the laboratory, typically receiving the treatment from ...
Moura M A - - 2002
The effects of exercise and water replacement on intraocular pressure (IOP) have not been well established. Furthermore, it is not known whether the temperature of the fluid ingested influences the IOP response. In the present study we determined the effect of water ingestion at three temperatures (10, 24 and 38 ...
Yanagimoto S - - 2002
To investigate the effects of physical training on heat loss response to sustained handgrip exercise (non-thermal factors), we compared the sweating response during isometric handgrip exercise to mild hyperthermia in physically trained and untrained subjects. Seven trained and untrained male subjects (maximal oxygen uptake 62.7 +/- 2.4 and 42.7 +/- ...
Walsh Jennifer - - 2002
PURPOSE: The purpose of this study was to determine and compare the thermoregulatory and hemodynamic responses to moderate intensity exercise (60% of peak oxygen consumption [.VO(2peak)]) in warm (35 degrees C, 45% relative humidity) and cool (18 degrees C, 65% relative humidity) environments in men who had previously undergone coronary ...
Richardson J E - - 2001
Firefighters in Queensland are exposed to hot, humid weather conditions that contribute to the overall workload encountered during emergency operations. Responding to certain hazardous material incidents requires firefighters to wear fully encapsulated chemical protective suits for a maximum period of 20 minutes. The nature of these suits, combined with workload ...
Gavin T P - - 2001
PURPOSE: We investigated whether temperature regulation is improved during exercise in moderate heat by the use of clothing constructed from fabric that was purported to promote sweat evaporation compared with traditional fabrics. METHODS: Eight well-trained, euhydrated males performed three exercise bouts wearing garments made from an evaporative polyester fabric (SYN), ...
Iskra-Golec I - - 2001
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 ...
Martin L - - 2001
The aim of this study was to assess the effect of time of day on physiological responses to running at the speed at the lactate threshold. After determination of the lactate threshold, using a standard incremental protocol, nine male runners (age 26.3 +/- 5.7 years, height 1.77 +/- 0.07 m, ...
Higham T E - - 2001
Although the maximal speeds of straight-ahead running are well-documented for many species of Anolis and other lizards, no previous study has experimentally determined the effects of turning on the locomotor performance of a lizard. Anolis lizards are a diverse group of arboreal species, and the discrete paths created by networks ...
Cheuvront S N - - 2001
Ad libitum fluid intakes and thermoregulatory responses were compared in eight female marathon runners during a 30 km treadmill run at individual best marathon race pace (range = 2.45-4.07 m x s(-1)) under three wet bulb globe temperature conditions (25 degrees C, 17 degrees C and 12 degrees C, corresponding ...
Callard D - - 2001
Circadian rhythms have formed the subject of many researches in man during bed rest or usual routine, but have been little studied during continuous and sustained physical exercise. This study deals with the influence of time of day on biological markers in competitive cyclists during continuous physical exercise versus continuous ...
Nybo L - - 2001
The present study tested the hypothesis that perceived exertion during prolonged exercise in hot environments is associated with changes in cerebral electrical activity rather than changes in the electromyogram (EMG) of the exercising muscles. Therefore, electroencephalogram (EEG) in three positions (frontal, central, and occipital cortex), EMG, rating of perceived exertion ...
Brugger H - - 2001
The median annual mortality from snow avalanches registered in Europe and North America 1981-1998 was 146 (range 82-226); trend stable in Alpine countries (r=-0.29; P=0.24), increasing in North America (r=0.68; P=0.002). Swiss data over the same period document 1886 avalanche victims, with an overall mortality rate of 52.4% in completely-buried, ...
Stebbins C L - - 2001
Caffeine can enhance mean arterial blood pressure (MAP) and attenuate forearm blood flow (FBF) and forearm vascular conductance (FVC) during exercise in thermal neutral conditions without altering body temperature. During exercise at higher ambient temperatures, where a greater transfer of heat from the body core to skin would be expected, ...
Gray S - - 2001
The aim of this study was to determine the influence of type of warm-up on metabolism and performance during high-intensity exercise. Eight males performed 30 s of intense exercise at 120% of their maximal power output followed, 1 min later, by a performance cycle to exhaustion, again at 120% of ...
Vanuxem P - - 2001
Muscle energy metabolism was studied in 30 subjects after recovery from exercise hyperthermia syndrome (EHTS subjects) and 15 healthy men with identical physical activities. Blood lactate, free fatty acid (FFA), serum creatine kinase activity (CK), and glycerol and the temperature in the auditory duct (T(c)) and on the thumb pad ...
Yamasaki M - - 2001
The purpose of this investigation was to clarify the characteristics of body temperature regulation in paraplegics due to spinal cord injury (SCI) during an arm cranking exercise in a hot environment. Twelve paraplegics with lesions located between Th3 and L1,2 and seven able-bodied subjects (AB) participated in this study. The ...
Nybo L - - 2001
1. In the present study we examined the effect of hyperthermia on the middle cerebral artery mean blood velocity (MCA V(mean)) during prolonged exercise. We predicted that the cerebral circulation would be impaired when hyperthermia is present during exercise and assumed that this could be observed as a reduced MCA ...
Clapp A J - - 2001
This study examined subjects that exercised on three occasions in a heated environment (WBGT = 39 degrees C] until they experienced heat strain. Since morbidity and mortality due to heat injury increase with the duration of elevated core temperature, it is important that techniques to lower core temperature be evaluated. ...
Booth J - - 2001
Muscle metabolism was investigated in seven men during two 35 min cycling trials at 60% peak oxygen uptake, at 35 degrees C and 50% relative humidity. On one occasion, exercise was preceded by whole-body cooling achieved by immersion in water during a reduction in temperature from 29 to 24 degrees ...
Fehrenbach E - - 2001
Overexpression of the heat shock protein HSP72 provides thermotolerance. We asked if two consecutive endurance runs 1 week apart (CR1, CR2) and additional environmental heat stress affect HSP72-expression in leukocytes of nonheat-acclimated endurance athletes. Twelve subjects were allocated randomly into two groups. Group HH completed both runs at 28 degrees ...
Mitchell J B - - 2001
The purpose of this study was to determine the effect of different cooling methods on thermoregulation before and after intermittent anaerobic exercise in the heat (38 degrees C). On separate days, 10 men completed 4 conditions consisting of 2 sets of six 30-second sprints (with 30 seconds of rest) at ...
Cotter J D - - 2001
Body cooling before exercise (i.e. pre-cooling) reduces physiological strain in humans during endurance exercise in temperate and warm environments, usually improving performance. This study examined the effectiveness of pre-cooling humans by ice-vest and cold (3 degrees C) air, with (LC) and without (LW) leg cooling, in reducing heat strain and ...
Mäkinen T T - - 2001
The effects of exercise intensity on thermoregulatory responses in cold (-10 degrees C) in a 0.2 (still air, NoWi), 1.0 (Wi1), and 5.0 (Wi5) m x s(-1) wind were studied. Eight young and healthy men, preconditioned in thermoneutral (+20 degrees C) environment for 60 min, walked for 60 min on ...
Sleivert G G - - 2001
Little research has been reported examining the effects of pre-cooling on high-intensity exercise performance, particularly when combined with strategies to keep the working muscle warm. This study used nine active males to determine the effects of pre-cooling the torso and thighs (LC), pre-cooling the torso (ice-vest in 3 degrees C ...
Sawasaki N - - 2001
We studied how, sympathetic response to cold exposure determines thermoregulatory function. Three female and seven male volunteers (age, 23.2+/-1.9 years) were exposed to abrupt local cooling and gradual systemic cooling with recording of microneurographic skin sympathetic nerve activity tSSNA), skill temperatures (Ts), tympanic temperature (Tty), skin blood flow measured by ...
Cleary M - - 2001
In cases in which ovarian tissue is to be cryopreserved for tissue or gene banking it is important to maintain its integrity and viability. This study examined how delays between the death of an animal and the collection/cryopreservation of its ovarian tissue influenced follicle viability. Mouse ovaries were placed in ...
Holme E - - 2001
PURPOSE: The purpose of the study was to investigate the core temperature responses to the induction of electrical exercise and to clarify whether an increase in temperature could be responsible for some of the observed reactions to acute and repeated exposure to electrical muscle stimulation. METHODS: The paralyzed thigh and ...
Sawka M N - - 2001
PURPOSE: This study determined whether exercise (30 min)-rest (10 min) cycles alter physiologic tolerance to uncompensable heat stress (UCHS) when outdoors in the desert. In addition, the relationship between core temperature and exhaustion from heat strain previously established in laboratory studies was compared with field studies. METHODS: Twelve men completed ...
Tardif J - - 2001
In the 'Des Vieux Arbres' ecological reserve situated within northwestern Quebec, 40 band dendrometers were installed on 7 of the major boreal tree species. The late Spring-early Summer daily radial activity registered in 1997 was related to daily weather variables. For each tree species, the daily mean i) cumulative radial ...
Theisen D - - 2001
This study investigated whether a 60-minute arm-cranking exercise at 50% of the individual maximal power output would increase lower limb skin blood flow (laser Doppler flowmetry) in individuals with high-level (T5-T9; n = 6) and low-level paraplegia (T10-T12; n = 6), compared to 6 able-bodied controls. Significant (P < 0.05) ...
Moffatt L L Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón II Ciudad Universitaria (1428), Buenos Aires, Argentina. - - 2001
During honeybee foraging, the stabilization of thoracic temperature (Tth) at elevated values is necessary to meet the power requirements of flight at different air temperatures (T(a)). To understand how the bee achieves thermal stability at different reward rates, the metabolic rates of undisturbed foraging bees were measured at different T(a) ...
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