scholarly journals Body mapping of sweating patterns of pre-pubertal children during intermittent exercise in a warm environment

2021 ◽  
Author(s):  
Leigh Arlegui ◽  
James W. Smallcombe ◽  
Damien Fournet ◽  
Keith Tolfrey ◽  
George Havenith
Keyword(s):  
Intermittent Exercise ◽  
Sweat Rate ◽  
The Body ◽  
Whole Body ◽  
Body Mapping ◽  
Warm Environment ◽  
The Mean ◽  
Lower Ratio ◽  
Hands And Feet ◽  
Sweating Patterns

Abstract Purpose To determine sweating responses of pre-pubertal children during intermittent exercise in a warm environment and create whole-body maps of regional sweat rate (RSRs) distribution across the body. Methods Thirteen pre-pubertal children; six girls and seven boys (8.1 ± 0.8 years) took part. Sweat was collected using the technical absorbent method in the last 5 min of a 30-min intermittent exercise protocol performed at 30 ℃, 40% relative humidity and 2 m·s−1 frontal wind. Results Mean gross sweat loss (GSL) was 126 ± 47 g·m−2·h−1 and metabolic heat production was 278 ± 50 W·m2. The lower anterior torso area had the lowest RSR with a median (IQR) sweat rate (SR) of 40 (32) g·m−2·h−1. The highest was the forehead with a median SR of 255 (163) g·m−2·h−1. Normalised sweat maps (the ratio of each region’s SR to the mean SR for all measured pad regions) showed girls displayed lower ratio values at the anterior and posterior torso, and higher ratios at the hands, feet and forehead compared to boys. Absolute SRs were similar at hands and feet, but girls sweated less in most other areas, even after correction for metabolic rate. Conclusion Pre-pubertal children have different RSRs across the body, also showing sex differences in sweat distribution. Distributions differ from adults. Hands and feet RSR remain stable, but SR across other body areas increase with maturation. These data can increase specificity of models of human thermoregulation, improve the measurement accuracy of child-sized thermal manikins, and aid companies during product design and communication.

scholarly journals A Multi-Channel Uncertainty-Aware Multi-Resolution Network for MR to CT Synthesis

2021 ◽  
Vol 11 (4) ◽  
pp. 1667
Author(s):  
Kerstin Klaser ◽  
Pedro Borges ◽  
Richard Shaw ◽  
Marta Ranzini ◽  
Marc Modat ◽  
...  
Keyword(s):  
Medical Image Analysis ◽  
Absolute Error ◽  
Magnetic Resonance Images ◽  
The Body ◽  
Whole Body ◽  
Image Size ◽  
Body Images ◽  
Image Translation ◽  
The Mean ◽  
Synthetic Ct

Synthesising computed tomography (CT) images from magnetic resonance images (MRI) plays an important role in the field of medical image analysis, both for quantification and diagnostic purposes. Convolutional neural networks (CNNs) have achieved state-of-the-art results in image-to-image translation for brain applications. However, synthesising whole-body images remains largely uncharted territory, involving many challenges, including large image size and limited field of view, complex spatial context, and anatomical differences between images acquired at different times. We propose the use of an uncertainty-aware multi-channel multi-resolution 3D cascade network specifically aiming for whole-body MR to CT synthesis. The Mean Absolute Error on the synthetic CT generated with the MultiResunc network (73.90 HU) is compared to multiple baseline CNNs like 3D U-Net (92.89 HU), HighRes3DNet (89.05 HU) and deep boosted regression (77.58 HU) and shows superior synthesis performance. We ultimately exploit the extrapolation properties of the MultiRes networks on sub-regions of the body.

Stance- and Locomotion-Dependent Processing of Vibration-Induced Proprioceptive Inflow From Multiple Muscles in Humans

2007 ◽  
Vol 97 (1) ◽  
pp. 772-779 ◽  
Author(s):  
Grégoire Courtine ◽  
Alessandro Marco De Nunzio ◽  
Micaela Schmid ◽  
Maria Vittoria Beretta ◽  
Marco Schieppati
Keyword(s):  
Lower Limb ◽  
The Body ◽  
Whole Body ◽  
Neck Muscle ◽  
Muscle Vibration ◽  
Mapping Study ◽  
Body Mapping ◽  
Neck Muscle Vibration ◽  
Postural Changes ◽  
Postural Orientation

We performed a whole-body mapping study of the effect of unilateral muscle vibration, eliciting spindle Ia firing, on the control of standing and walking in humans. During quiet stance, vibration applied to various muscles of the trunk-neck system and of the lower limb elicited a significant tilt in whole body postural orientation. The direction of vibration-induced postural tilt was consistent with a response compensatory for the illusory lengthening of the stimulated muscles. During walking, trunk-neck muscle vibration induced ample deviations of the locomotor trajectory toward the side opposite to the stimulation site. In contrast, no significant modifications of the locomotor trajectory could be detected when vibrating various muscles of the lower as well as upper limb. The absence of correlation between the effects of muscle vibration during walking and standing dismisses the possibility that vibration-induced postural changes can account for the observed deviations of the locomotor trajectory during walking. We conclude that the dissimilar effects of trunk-neck and lower limb muscle vibration during walking and standing reflect a general sensory-motor plan, whereby muscle Ia input is processed according to both the performed task and the body segment from which the sensory inflow arises.

scholarly journals Structural Organization of the Optic Lobe of Grey Breasted Helmeted Guinea Fowl (*Numida meleagris galeata*) at Pre-Hatch Study

2016 ◽  
Vol 7 (2) ◽  
pp. 26
Author(s):  
Wanmi Nathaniel ◽  
Onyeanusi I. Barth ◽  
Nzalak J. Oliver ◽  
Aluwong Tanang
Keyword(s):  
Body Weight ◽  
Structural Organization ◽  
Optic Lobe ◽  
Guinea Fowl ◽  
The Body ◽  
Whole Body ◽  
Steady Increase ◽  
Numida Meleagris ◽  
The Mean ◽  
Immature Cells

<p class="jbls-body"><span lang="EN-GB">A total of one hundred and seventy-three fertilized eggs were used for morphometry, gross and histological studies. At day 4 of incubation, the mean body weight of the helmeted guinea fowl embryo was 0.6401 ± 0.0211 g. It was at day 10 of incubation that there was an increase in the whole body weight of the embryo to be 0.8650 ± 0.676 g. The whole brain weight indicated relative increased at day 4 as compared to that of the whole body weight. Graphically, there were steady increase in the body, brain and optic lobe weights. Histologically, cells and neurones that make up the optic lobe is probably as a result of the migration of immature cells from the ventricular neuroepithelium. </span></p>

Humid heat acclimation does not elicit a preferential sweat redistribution toward the limbs

2004 ◽  
Vol 286 (3) ◽  
pp. R512-R518 ◽  
Author(s):  
Mark J. Patterson ◽  
Jodie M. Stocks ◽  
Nigel A. S. Taylor
Keyword(s):  
Relative Humidity ◽  
Sweat Rate ◽  
Heat Acclimation ◽  
Relative Increase ◽  
Work Rate ◽  
Whole Body ◽  
Stress Tests ◽  
Work Intensity ◽  
Mean Body Temperature ◽  
The Mean

We tested the hypothesis that local sweat rates would not display a systematic postadaptation redistribution toward the limbs after humid heat acclimation. Eleven nonadapted males were acclimated over 3 wk (16 exposures), cycling 90 min/day, 6 days/wk (40°C, 60% relative humidity), using the controlled-hyperthermia acclimation technique, in which work rate was modified to achieve and maintain a target core temperature (38.5°C). Local sudomotor adaptation (forehead, chest, scapula, forearm, thigh) and onset thresholds were studied during constant work intensity heat stress tests (39.8°C, 59.2% relative humidity) conducted on days 1, 8, and 22 of acclimation. The mean body temperature (T̄b) at which sweating commenced (threshold) was reduced on days 8 and 22 ( P < 0.05), and these displacements paralleled the resting thermoneutral T̄b shift, such that the T̄b change to elicit sweating remained constant from days 1 to 22. Whole body sweat rate increased significantly from 0.87 ± 0.06 l/h on day 1 to 1.09 ± 0.08 and 1.16 ± 0.11 l/h on days 8 and 22, respectively. However, not all skin regions exhibited equivalent relative sweat rate elevations from day 1 to day 22. The relative increase in forearm sweat rate (117 ± 31%) exceeded that at the forehead (47 ± 18%; P < 0.05) and thigh (42 ± 16%; P < 0.05), while the chest sweat rate elevation (106 ± 29%) also exceeded the thigh ( P < 0.05). Two unique postacclimation observations arose from this project. First, reduced sweat thresholds appeared to be primarily related to a lower resting T̄b, and more dependent on T̄b change. Second, our data did not support the hypothesis of a generalized and preferential trunk-to-limb sweat redistribution after heat acclimation.

scholarly journals Model of metameric locomotion in smooth active directional filaments with curvature fluctuations

2021 ◽  
Author(s):  
Guangle Du ◽  
Sunita Kumari ◽  
Fangfu Ye ◽  
Rudolf Podgornik
Keyword(s):  
Theoretical Model ◽  
Planck Equation ◽  
The Body ◽  
Whole Body ◽  
Langevin Equations ◽  
Mean Square ◽  
Fokker Planck Equation ◽  
Directional Motion ◽  
The Mean ◽  
Fokker Planck

Abstract Locomotion in segmented animals, such as annelids and myriapods (centipedes and millipedes), is generated by a coordinated movement known as metameric locomotion, which can be also implemented in robots designed to perform specific tasks. We introduce a theoretical model, based on an active directional motion of the head segment and a passive trailing of the rest of the body segments, in order to formalize and study the metameric locomotion. The model is specifically formulated as a steered Ornstein-Uhlenbeck curvature process, preserving the continuity of the curvature along the whole body filament, and thus supersedes the simple active Brownian model, which would be inapplicable in this case. We obtain the probability density by analytically solving the Fokker-Planck equation pertinent to the model. We also calculate explicitly the correlators, such as the mean-square orientational fluctuations, the orientational correlation function and the mean-square separation between the head and tail segments, both analytically either via the Fokker-Planck equation or directly by either solving analytically or implementing it numerically from the Langevin equations. The analytical and numerical results coincide. Our theoretical model can help understand the locomotion of metameric animals and instruct the design of metameric robots.

Exercise-rest cycles do not alter local and whole body heat loss responses

2011 ◽  
Vol 300 (4) ◽  
pp. R958-R968 ◽  
Author(s):  
Daniel Gagnon ◽  
Glen P. Kenny
Keyword(s):  
Heat Loss ◽  
Core Temperature ◽  
Intermittent Exercise ◽  
Sweat Rate ◽  
Heat Content ◽  
Whole Body ◽  
Evaporative Heat Loss ◽  
Esophageal Temperature ◽  
Direct Calorimetry ◽  
Body Heat

Previous studies have suggested that greater core temperatures during intermittent exercise (Ex) are due to attenuated sweating [upper back sweat rate (SR)] and skin blood flow (SkBF) responses. We evaluated the hypothesis that heat loss is not altered during exercise-rest cycles (ER). Ten male participants randomly performed four 120-min trials: 1) 60-min Ex and 60-min recovery (60ER); 2) 3 × 20-min Ex separated by 20-min recoveries (20ER); 3) 6 × 10-min Ex separated by 10-min recoveries (10ER), or 4) 12 × 5-min Ex separated by 5-min recoveries (5ER). Exercise was performed at a workload of 130 W at 35°C. Whole body heat exchange was determined by direct calorimetry. Core temperature, SR (by ventilated capsule), and SkBF (by laser-doppler) were measured continuously. Evaporative heat loss (EHL) progressively increased with each ER, such that it was significantly greater ( P ≤ 0.05) at the end of the last compared with the first Ex for 5ER (299 ± 39 vs. 440 ± 41 W), 10ER (425 ± 51 vs. 519 ± 45 W), and 20ER (515 ± 63 vs. 575 ± 74 W). The slope of the EHL response against esophageal temperature significantly increased from the first to the last Ex within the 10ER (376 ± 56 vs. 445 ± 89 W/°C, P ≤ 0.05) and 20ER (535 ± 85 vs. 588 ± 28 W/°C, P ≤ 0.05) conditions, but not during 5ER (296 ± 96 W/°C vs. 278 ± 95 W/°C, P = 0.237). In contrast, the slope of the SkBF response against esophageal temperature did not significantly change from the first to the last Ex (5ER: 51 ± 23 vs. 54 ± 19%/°C, P = 0.848; 10ER: 53 ± 8 vs. 56 ± 21%/°C, P = 0.786; 20ER: 44 ± 20 vs. 50 ± 27%/°C, P = 0.432). Overall, no differences in body heat content and core temperature were observed. These results suggest that altered local and whole body heat loss responses do not explain the previously observed greater core temperatures during intermittent exercise.

scholarly journals Effect of Fourteen Days of Acclimatization on Athletic Performance in Tropical Climate

2002 ◽  
Vol 27 (6) ◽  
pp. 551-562 ◽  
Author(s):  
Bruno Voltaire ◽  
Olivier Galy ◽  
Olivier Coste ◽  
Sébastien Racinais ◽  
André Callis ◽  
...  
Keyword(s):  
Mass Loss ◽  
Body Mass ◽  
Sweat Rate ◽  
Tropical Climate ◽  
The Body ◽  
Tympanic Temperature ◽  
Body Mass Loss ◽  
Tropical Conditions ◽  
The Mean ◽  
And Performance

In order to study the acclimatization process over 14 days of exposure to tropical climate, 9 triathletes performed 4 outdoor indirect continuous multistage tests in both thermoneutral and tropical conditions. The thermoneutral test (TN, 14 °C, 45% rh) was performed before traveling to the tropical area (Martinique, FWI). The tropical tests were performed 2, 8, and 14 days after arrival (32.9 °C, 78% rh). During each trial, we measured tympanic temperature, sweat rate, body mass loss, heart rate (HR), and performance. The results showed that 1) the mean tympanic temperature was greater in T2 (P < .001), T8 (P < .01) and T14 (P < .01) than in TN and significantly lower in T14 than in T2 (P < .05); 2) the mean sweat rate was significantly greater (P < .001) in T2, T8 and T14 than in TN and significantly greater (P < .05) in T8 and T14 than in T2; 3) the body mass loss after trials was significantly greater (P < .001) in T2, T8 and T14 than in TN and significantly greater (P < .05) in T8 and T14 than in T2; 4) the mean HR and HR at rest were significantly higher (P < .005) in T2 than in TN, T8, T14 and the mean HR was significantly lower (P < .05) in T14 than in the other trials; and 5) the performance time was significantly lower in T2 (P < 0.02), T8 (P < 0.03) and T14 (P < 0.05) than in TN. We concluded that 14 days of exposure to tropical climate led to changes in physiological parameters but were still insufficient to ensure complete acclimatization in well-trained athletes. The hot/wet climate induced impairment of physiological responses and performance that were still evident on the 14th day. Keywords: triathletes, aerobic performance, jet lag, dehydration, hyperthermia

scholarly journals Body mapping of regional sweat distribution in young and older males

2020 ◽  
Author(s):  
Nicole A. Coull ◽  
Anna M. West ◽  
Simon G. Hodder ◽  
Patrick Wheeler ◽  
George Havenith
Keyword(s):  
Heat Production ◽  
Thermal Sensation ◽  
Sweat Rate ◽  
Whole Body ◽  
Body Region ◽  
Sweat Loss ◽  
Body Mapping ◽  
Body Regions ◽  
Age Related ◽  
Older Males

Abstract Purpose Given the pressing impact of global warming and its detrimental effect on the health of older populations, understanding age-related changes in thermoregulatory function is essential. Age differences in regional sweat distribution have been observed previously, but given the typically small measurement areas assessed, the development of whole body sweat maps for older individuals is required. Therefore, this study investigated age-related differences in regional sweat distribution in a hot environment (32 °C/50%RH) in young and older adults, using a body mapping approach. Methods Technical absorbent pads were applied to the skin of 14 young (age 24 ± 2 years) and 14 older (68 ± 5 years) males to measure regional sweat rate (RSR) at rest (30 min) and during exercise (30 min), at a fixed heat production (200 W m−2). Gastrointestinal (Tgi) and skin temperature (Tsk), heart rate, thermal sensation, and thermal comfort were also measured. Results Whole body sweat maps showed that despite equal heat production, healthy older males had significantly lower gross sweat loss (GSL) than the young and significantly lower RSR at almost all body regions at rest and at the hands, legs, ankles, and feet during exercise. The lower sweat loss in the older group coincided with a greater increase in Tgi and a consistently higher Tsk at the legs, despite subjectively feeling slightly cooler than younger individuals. Conclusion These findings support the evidence of age-related deterioration in both autonomic and subjective responses in the heat and highlight the lower extremities as the most affected body region.

Experiments upon the heart of the dog with reference to the maximum volume of blood sent out by the left ventricle in a single beat, and the influence of variations in venous pressure, arterial pressure, and pulse rate upon the work done by the heart

1883 ◽  
Vol 35 (224-226) ◽  
pp. 271-274
Keyword(s):  
Left Ventricle ◽  
Axillary Artery ◽  
Venous Pressure ◽  
The Body ◽  
Whole Body ◽  
Average Weight ◽  
Mean Velocity ◽  
The Subject ◽  
The Mean ◽  
Work Done

Owing to the indirectness of the methods hitherto used for estimating the quantity of blood pumped out from the left ventricle at each systole, this important factor in all calculations of the work done by the heart has never been satisfactorily determined. Of the later physiologists who have investigated the subject, Volkmann and afterwards Vierordt, from calculations based upon the mean velocity of the stream of blood in the unbranched aorta, obtained the fraction 1/100 as representing the ratio of the average weight of blood ejected at each systole of the left ventricle to the weight of the whole body. Fick, from data obtained by placing the arm in a plethysmograph, and estimating the velocity of the stream of blood in the axillary artery from the increase in volume of the whole arm at each systole of the heart, arrived at a much smaller fraction, about 1/1000 for the ratio between the weight of blood thrown out at each systole and the body weight.

Iron Metabolism after Renal Transplantation

1973 ◽  
Vol 44 (1) ◽  
pp. 27-32 ◽  
Author(s):  
K. Boddy ◽  
G. Will ◽  
D. H. Lawson ◽  
Priscilla C. King ◽  
A. L. Linton
Keyword(s):  
Renal Failure ◽  
Renal Transplantation ◽  
Chronic Renal Failure ◽  
Iron Metabolism ◽  
Oral Absorption ◽  
Normal Subjects ◽  
The Body ◽  
Whole Body ◽  
The Mean

1. The oral absorption and the rate of loss from the body of radioactive iron were measured by whole-body monitoring in patients with functioning renal homografts. The incorporation of radioactive iron into erythrocytes was also measured. 2. The results were compared with corresponding values in normal subjects and in non-dialysed and dialysed patients with chronic renal failure. 3. The mean oral absorption and incorporation into erythrocytes of radioactive iron was intermediate between that of normal subjects and of both non-dialysed and dialysed patients with chronic renal failure. 4. The mean rate of loss from the body was not significantly different from that in normal subjects and non-dialysed patients with chronic renal failure but it was significantly less than that in dialysed patients.

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