Central and peripheral factors in thermal, neuromuscular, and perceptual adaptation of the hand to repeated cold exposures

2006 ◽  
Vol 31 (2) ◽  
pp. 110-117 ◽  
Author(s):  
Carla L.M Geurts ◽  
Gordon G Sleivert ◽  
Stephen S Cheung
Keyword(s):  
Cold Water ◽  
Thermal Sensation ◽  
Cardiovascular Response ◽  
Temperature Response ◽  
Neuromuscular Function ◽  
Finger Temperature ◽  
Left Hand ◽  
Control Right ◽  
And Control ◽  
Over Time

We investigated the role of central and peripheral factors in repeated cold exposure of the hand and their effects on temperature response, neuromuscular function, and subjective thermal sensation. Eleven subjects immersed their left hand repeatedly in 8 °C cold water for 30 min, 5 d/week, for 2 weeks. Before and following the 2 weeks of exposure, neuromuscular function, blood markers, thermal sensation, and temperature responses of both acclimated (left) and control (right) hands were tested. Minimum index finger temperature pre-acclimation was 10.9 ± 3.4 °C and 10.0 ± 2.0 °C in the left and right hand, respectively, and did not change significantly post-acclimation (left, 12.8 ± 4.2 °C; right, 10.2 ± 1.1 °C). Neuromuscular function was impaired with cooling, but this was significantly different neither between the hands nor over time. Central factors, measured by catecholamines and changes in temperature and cardiovascular response over time, did not change and there were no differences in responses between the exposed and non-exposed hand over time (peripheral adaptation) nor were there any differences in local factors endothelian-1 and nitric oxide. Subjective thermal comfort was improved and the discepancy that was found between the change in actual and perceived temperature may increase the risk of cold injury in partially acclimatized individuals, owing to an adjustment in behavioural thermoregulation.Key words: hand, skin temperature, cold-induced vasodilatation, neuromuscular function, manual dexterity.

Effect of cold acclimation on neuromuscular function of the hand

2006 ◽  
Vol 31 (4) ◽  
pp. 480-481
Author(s):  
Carla L.M. Geurts
Keyword(s):  
Cold Stress ◽  
Cold Acclimation ◽  
Cold Exposure ◽  
Force Control ◽  
Cold Water ◽  
Water Immersion ◽  
Temperature Response ◽  
Neuromuscular Function ◽  
Cold Water Immersion ◽  
Hand Temperature

The research in this thesis investigated the effects of cold stress on neuromuscular function with the main focus on cold acclimation. In total, 6 studies, 1 field study and 5 experiments, were conducted. The field study showed that during manual work in cold weather, finger and hand temperature can drop to levels that may impair manual function. The first 2 experiments were conducted to investigate the effect of acute local cold stress on force control and to investigate the effect of cold-induced vasodilatation (CIVD) on neuromuscular function. In experiment 1, it was found that cooling of the hand in 10 °C cold water for 10 min did not improve force control, although neuromuscular function was significantly impaired after cooling. In experiment 2, cold-induced vasodilatation, occurring after 20 min of 8 °C cold-water immersion of the hand, was confined to the finger tip and had no effect on the temperature of the first dorsal interosseus (FDI) muscle or its neuromuscular function. A series of cold acclimation studies was conducted to investigate the effect of repeated cold-water hand immersions on neuromuscular function. In these experiments, neuromuscular function was tested before and after 2–3 weeks of daily hand immersion in 8 °C cold water for 30 min. In experiment 3, it was found that 3 weeks of cold-water immersion resulted in a decrease in minimum and mean index finger temperature and CIVD was attenuated. Neuromuscular function was not affected by this change in temperature response. In experiment 4, one hand was exposed daily to cold water and compared with the opposite control hand. Blood plasma catecholamine concentrations were increased after 2 weeks in the cold-exposed hand, but no changes in temperature response or neuromuscular function were found after repeated cold exposure. Thermal comfort after 30 min of cold-water immersion significantly improved after repeated cold exposure causing a discrepancy between actual and perceived temperature and it was suggested that this may impose a greater risk of cold injury owing to a change in behavioural thermoregulation. In the last experiment, core temperature was elevated by bicycling at a submaximal level during the cold hand immersion. Exercise had a direct effect on the temperature response during cold-water immersion, decreasing the minimum FDI temperature and slowing down the deteriorating effect of cold on neuromuscular function; however, exercise showed was no effect on local cold acclimation. It is concluded that local repeated cold exposures may improve finger and hand temperature and subjective thermal ratings, but that these changes are too small to improve neuromuscular function. The best remedy to maintain manual function is to limit or avoid cold stress as much as possible. If sufficient protection of the hands is impossible, core heating through exercise or passive heating may be a solution.

scholarly journals Reproducibility of the cold-induced vasodilation response in the human finger

2005 ◽  
Vol 98 (4) ◽  
pp. 1334-1340 ◽  
Author(s):  
Catherine O'Brien
Keyword(s):  
Blood Flow ◽  
Time Course ◽  
Cold Water ◽  
Temperature Response ◽  
Onset Time ◽  
Middle Finger ◽  
Warm Water ◽  
Finger Temperature ◽  
Nail Bed ◽  
Human Finger

Cold-induced vasodilation (CIVD) is a cyclic oscillation in blood flow that occurs in the extremities on cold exposure and that is likely associated with reduced risk of cold injury (e.g., frostbite) as well as improved manual dexterity and less pain while working in the cold. The CIVD response varies between individuals, but the within-subject reproducibility has not been adequately described. The purpose of this study was to quantify the within-subject variability in the CIVD response under standardized conditions. Twenty-one volunteers resting in a controlled environment (27°C) immersed the middle finger in warm water (42°C) for 15 min to standardize initial finger temperature and then in cold water (4°C; CWI) for 30 min, on five separate occasions. Skin temperature (Tf) and blood flow (laser-Doppler; expressed as percent change from warm-water peak) responses that describe CIVD were identified, including initial nadir reached during CWI, onset time of CIVD, initial apex during CIVD, time of that apex, and overall mean during CWI. Within-subject coefficient of variation for Tfacross the five tests for the nail bed and pad, respectively, were as follows: nadir, 9 and 21%; onset, 18 and 19%; apex, 12 and 17%; apex time, 23 and 24%; mean 10 and 15%. For blood flow, these values were as follows: nadir 52 and 64%; onset, 6 and 5%; apex, 33 and 31%; apex time 9 and 8%; and mean 43 and 34%. Greater variability was found in the temperature response of the finger pad than the nail bed, but for blood flow the variability was similar between locations. Variability in onset and apex time between sites was similar for both temperature and blood flow responses. The reproducibility of the time course of CIVD suggests this methodology may be of value for further studies examining the mechanism of the response.

Tolerance of Gaspé fishermen to cold water

1960 ◽  
Vol 15 (6) ◽  
pp. 1031-1034 ◽  
Author(s):  
Jacques LeBlanc ◽  
J. A. Hildes ◽  
O. Héroux
Keyword(s):  
Cold Water ◽  
Pressor Response ◽  
Water Immersion ◽  
Cold Water Immersion ◽  
Control Group ◽  
Skin Thickness ◽  
Finger Temperature ◽  
Control Subjects ◽  
Skin Biopsies ◽  
And Control

A group of Gaspé fishermen used to cold water immersion and control subjects from the same vicinity were studied to determine if the fishermen's hands were adapted to cold. With one hand immersed in cold water, the pressor response was greater in the control subjects; the fishermen maintained a higher finger temperature and complained less of pain; heat flow from the fishermen's hands was greater than in the control group; finger numbness as measured by a modification of Mackworth's V-test was variable and not significantly different in the two groups. Skin biopsies showed no difference in skin thickness or cell size but there was a significantly greater number of mast cells in the fishermen's skin. The differences between the fishermen and the control subjects may be related to repeated cold exposure. Submitted on June 7, 1960

Hypothermic facilitation of retrograde V-A conduction

1960 ◽  
Vol 15 (6) ◽  
pp. 1035-1040 ◽  
Author(s):  
Carolyn K. Francis ◽  
Carol A. Campbell ◽  
H. E. Hoff
Keyword(s):  
Cold Water ◽  
Pressor Response ◽  
Water Immersion ◽  
Cold Water Immersion ◽  
Control Group ◽  
Skin Thickness ◽  
Finger Temperature ◽  
Control Subjects ◽  
Skin Biopsies ◽  
And Control

A group of Gaspé fishermen used to cold water immersion and control subjects from the same vicinity were studied to determine if the fishermen's hands were adapted to cold. With one hand immersed in cold water, the pressor response was greater in the control subjects; the fishermen maintained a higher finger temperature and complained less of pain; heat flow from the fishermen's hands was greater than in the control group; finger numbness as measured by a modification of Mackworth' V-test was variable and not significantly different in the two groups. Skin biopsies showed no difference in skin thickness or cell size but there was a significantly greater number of mast cells in the fishermen's skin. The differences between the fishermen and the control subjects may be related to repeated cold exposure. Submitted on June 7, 1960

Israel’s Ground Forces in the Occupied Territories

2020 ◽  
Vol 35 (2) ◽  
pp. 37-57
Author(s):  
Eyal Ben-Ari ◽  
Uzi Ben-Shalom
Keyword(s):  
High Intensity ◽  
Force Generation ◽  
Institutional Autonomy ◽  
Multiple Forms ◽  
The West ◽  
Occupied Territories ◽  
Media Monitoring ◽  
Israel Defense Forces ◽  
And Control ◽  
Over Time

The Israel Defense Forces (IDF) routinely rotate ground forces in and out of the Occupied Territories in the West Bank. While these troops are trained for soldiering in high-intensity wars, in the Territories they have long had to carry out a variety of policing activities. These activities often exist in tension with their soldierly training and ethos, both of which center on violent encounters. IDF ground forces have adapted to this situation by maintaining a hierarchy of ‘logics of action’, in which handling potentially hostile encounters takes precedence over other forms of policing. Over time, this hierarchy has been adapted to the changed nature of contemporary conflict, in which soldiering is increasingly exposed to multiple forms of media, monitoring, and juridification. To maintain its public legitimacy and institutional autonomy, the IDF has had to adapt to the changes imposed on it by creating multiple mechanisms of force generation and control of soldierly action.

Domains of Socialization

2019 ◽  
pp. 72-90
Author(s):  
Joan E. Grusec
Keyword(s):  
Young Adults ◽  
Zone Of Proximal Development ◽  
Proximal Development ◽  
Group Participation ◽  
Guided Learning ◽  
Positive Action ◽  
Affect And Cognition ◽  
And Control ◽  
Value Learning ◽  
Over Time

This chapter surveys how behavior, affect, and cognition with respect to parenting and moral development have been conceptualized over time. It moves to a discussion of domains of socialization; that is, different contexts in which socialization occurs and where different mechanisms operate. Domains include protection where the child is experiencing negative affect, reciprocity where there is an exchange of favors, group participation or learning through observing others and engaging with them in positive action, guided learning where values are taught in the child’s zone of proximal development, and control where values are learned through discipline and reward. Research using narratives of young adults about value-learning events suggests that inhibition of antisocial behavior is more likely learned in the control domain, and prosocial behavior more likely in the group participation domain. Internalization of values, measured by narrative meaningfulness, is most likely in the group participation domain.

scholarly journals Clinical characterization of dysautonomia in long COVID-19 patients

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nicolas Barizien ◽  
Morgan Le Guen ◽  
Stéphanie Russel ◽  
Pauline Touche ◽  
Florent Huang ◽  
...  
Keyword(s):  
Mixed Models ◽  
Repeated Measures ◽  
Physical Medicine ◽  
Persistent Symptoms ◽  
Index Changes ◽  
Changes Over Time ◽  
And Control ◽  
Testing Group ◽  
Over Time

AbstractIncreasing numbers of COVID-19 patients, continue to experience symptoms months after recovering from mild cases of COVID-19. Amongst these symptoms, several are related to neurological manifestations, including fatigue, anosmia, hypogeusia, headaches and hypoxia. However, the involvement of the autonomic nervous system, expressed by a dysautonomia, which can aggregate all these neurological symptoms has not been prominently reported. Here, we hypothesize that dysautonomia, could occur in secondary COVID-19 infection, also referred to as “long COVID” infection. 39 participants were included from December 2020 to January 2021 for assessment by the Department of physical medicine to enhance their physical capabilities: 12 participants with COVID-19 diagnosis and fatigue, 15 participants with COVID-19 diagnosis without fatigue and 12 control participants without COVID-19 diagnosis and without fatigue. Heart rate variability (HRV) during a change in position is commonly measured to diagnose autonomic dysregulation. In this cohort, to reflect HRV, parasympathetic/sympathetic balance was estimated using the NOL index, a multiparameter artificial intelligence-driven index calculated from extracted physiological signals by the PMD-200 pain monitoring system. Repeated-measures mixed-models testing group effect were performed to analyze NOL index changes over time between groups. A significant NOL index dissociation over time between long COVID-19 participants with fatigue and control participants was observed (p = 0.046). A trend towards significant NOL index dissociation over time was observed between long COVID-19 participants without fatigue and control participants (p = 0.109). No difference over time was observed between the two groups of long COVID-19 participants (p = 0.904). Long COVID-19 participants with fatigue may exhibit a dysautonomia characterized by dysregulation of the HRV, that is reflected by the NOL index measurements, compared to control participants. Dysautonomia may explain the persistent symptoms observed in long COVID-19 patients, such as fatigue and hypoxia. Trial registration: The study was approved by the Foch IRB: IRB00012437 (Approval Number: 20-12-02) on December 16, 2020.

scholarly journals Salmonella Bacterin Vaccination Decreases Shedding and Colonization of Salmonella Typhimurium in Pigs

2021 ◽  
Vol 9 (6) ◽  
pp. 1163
Author(s):  
Eduarda Alexandra Gonçalves de Oliveira Moura ◽  
Daniela Gomes da Silva ◽  
Caio Henrique Turco ◽  
Thainara Vitoria Carnevalli Sanches ◽  
Gabriel Yuri Storino ◽  
...  
Keyword(s):  
Salmonella Typhimurium ◽  
Blood Count ◽  
Control Strategies ◽  
Control Group ◽  
Blood Samples ◽  
Commercial Vaccine ◽  
Serum Igg ◽  
And Control ◽  
Experimental Group ◽  
Over Time

Since the occurrence of swine salmonellosis has increased over time and control strategies other than biosecurity are highly recommended, the present study aimed to evaluate the efficacy of vaccination with Salmonella Choleraesuis and Salmonella Typhimurium bacterins in pigs. Two experimental groups were formed: G1, animals immunized with two doses of a commercial vaccine (n = 20); G2, control group (n = 20). After vaccination, all pigs were orally challenged (D0) with 108 CFU of Salmonella Typhimurium and evaluated for 40 days. Every 10 days after D0, five piglets from each experimental group were euthanized and submitted to the necroscopic examination, when organ samples were collected. Blood samples and rectal swabs were collected before the first dose of the vaccine (D−42), before the second dose (D−21), before the challenge (D0), and thereafter, every three days until D39. Blood count, serum IgG measurement by ELISA, and the excretion of Salmonella Typhimurium in feces were evaluated. While the results from blood count and serum IgG concentration did not differ, the detection and excretion of Salmonella between G1 and G2 differed (p < 0.05). Therefore, it was observed that this vaccine partially protected the animals against experimental infection with Salmonella Typhimurium, reducing the excretion of bacteria in feces.

Effects of Face Mask Use on Objective and Subjective Measures of Thermoregulation During Exercise in the Heat

2021 ◽  
pp. 194173812110282
Author(s):  
Ayami Yoshihara ◽  
Erin E. Dierickx ◽  
Gabrielle J. Brewer ◽  
Yasuki Sekiguchi ◽  
Rebecca L. Stearns ◽  
...  
Keyword(s):  
Exercise Intensity ◽  
Thermal Sensation ◽  
Face Mask ◽  
Whole Body ◽  
Moderate Exercise ◽  
Physically Active ◽  
Time Points ◽  
The Face ◽  
And Control ◽  
Moderate Exercise Intensity

Background: While increased face mask use has helped reduce COVID-19 transmission, there have been concerns about its influence on thermoregulation during exercise in the heat, but consistent, evidence-based recommendations are lacking. Hypothesis: No physiological differences would exist during low-to-moderate exercise intensity in the heat between trials with and without face masks, but perceptual sensations could vary. Study Design: Crossover study. Level of Evidence: Level 2. Methods: Twelve physically active participants (8 male, 4 female; age = 24 ± 3 years) completed 4 face mask trials and 1 control trial (no mask) in the heat (32.3°C ± 0.04°C; 54.4% ± 0.7% relative humidity [RH]). The protocol was 60 minutes of walking and jogging between 35% and 60% of relative VO2max. Rectal temperature (Trec), heart rate (HR), temperature and humidity inside and outside of the face mask (Tmicro_in, Tmicro_out, RHmicro_in, RHmicro_out) and perceptual variables (rating of perceived exertion (RPE), thermal sensation, thirst sensation, fatigue level, and overall breathing discomfort) were monitored throughout all trials. Results: Mean Trec and HR increased at 30- and 60-minute time points compared with 0-minute time points, but no difference existed between face mask trials and control trials ( P > 0.05). Mean Tmicro_in, RHmicro_in, and humidity difference inside and outside of the face mask (ΔRHmicro) were significantly different between face mask trials ( P < 0.05). There was no significant difference in perceptual variables between face mask trials and control trials ( P > 0.05), except overall breathing discomfort ( P < 0.01). Higher RHmicro_in, RPE, and thermal sensation significantly predicted higher overall breathing discomfort ( r2 = 0.418; P < 0.01). Conclusion: Face mask use during 60 minutes of low-to-moderate exercise intensity in the heat did not significantly affect Trec or HR. Although face mask use may affect overall breathing discomfort due to the changes in the face mask microenvironment, face mask use itself did not cause an increase in whole body thermal stress. Clinical Relevance: Face mask use is feasible and safe during exercise in the heat, at low-to-moderate exercise intensities, for physically active, healthy individuals.

STUDIES ON HABITUATION TO COLD PAIN

1966 ◽  
Vol 44 (2) ◽  
pp. 287-293 ◽  
Author(s):  
Jacques LeBlanc ◽  
Pierre Potvin
Keyword(s):  
Cold Water ◽  
Mental Arithmetic ◽  
Blood Pressure Response ◽  
Human Subjects ◽  
Cold Pain ◽  
Left Hand ◽  
Water Test ◽  
The Difference ◽  
The Right ◽  
Habituation To Cold

It was possible to produce habituation to cold in a group of human subjects by immersing the left hand in cold water for [Formula: see text] minutes twice a day for 19 days. The right hand did not adapt. Another group of subjects was exposed similarly with the difference that an anxiety test (mental arithmetic test) was always given simultaneously with the cold-water test. In this second group the original blood pressure response, i.e. for the first day, was greater than in the first group because of the cumulative effects of the two tests. After 19 days definite evidence was obtained for adaptation to these two tests administered together. However, when these tests were given separately to the second group, no adaptation was evident; adaptation occurred only to both tests given simultaneously. These results indicate that no adaptation develops to cold per se if the subjects are distracted from cold discomfort. It was also found that adaptation of one hand to cold water not only failed to induce adaptation in the opposite hand but even reinforced responses of the unadapted hand. These findings suggest a participation of the central nervous system in adaptation to cold pain, and tend to minimize the importance of local peripheral changes.

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