Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “COLD CLIMATE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,495 records · Page 83Linked to original sources
PubMed1980

Na+ and Ca2+ ingestion: plasma volume-electrolyte distribution at rest and exercise.

Plasma volume (PV), protein, and electrolyte shifts were measured in two groups of five men in the supine position during rest, exercise (40-47% VO2max), and recovery in cool (Ta = 26.5 degrees C) and hot (Ta = 39.4 degrees C) environments. They drank 16-17 ml/kg hypertonic (1.5%) NaCl, isotonic (0.9%) NaCl, or hypertonic (1.5%) calcium gluconate solutions during the preexercise rest period. Hyper-Na consumption retarded the rise in PV (hypervolemia) at rest in the cool but not in the heat. Ingestion of iso-Na and hyper-Na resulted in twofold greater hypervolemia at rest in the heat. During exercise and recovery, PV was highest with hyper-Na in the heat. Hyper-Ca prevented the normal hypervolemic response at rest in both environments. The normal hypervolemic responses during exercise were not influenced by any drink composition. The results suggest hypertonic drinks may be better for maintaining PV levels during exercise in heat; but calcium must be used with care.

Adult↗
PubMed1991

Quantification of conservative endurance times in thermally insulated cold-stressed digits.

The estimation of endurance times of the digits exposed to cold weather is performed by an analytical, one-dimensional cylindrical model. Blood perfusion effects are lumped into a volumetric heat-generation term. Cold-induced vasodilatation (CIVD) effects are not included in the present analysis. Endurance times, defined by a drop in cylinder tip temperature to 5 degrees C, were evaluated. Parameters included in this evaluation were 1) environmental temperatures, 2) thermal insulation applied on the cylinder, 3) length of the cylinder, and 4) diameter of the cylinder. It was found that the lower the ambient temperature, the longer the finger, and the smaller its diameter, then the shorter the endurance time for the same thermal insulation. Results of the model were compared with measured data for a subject not exhibiting CIVD response to cold stress. Conformity of results calculated for an adjusted value of the volumetric heat-generation term and measured data was very good, with a maximum deviation of less than 10% at only one particular point in time. This model facilitates the conservative estimation of lower bounds to thermally insulated fingers and toes exposed to cold stress.

Body Temperature Regulation↗
PubMed1992

Physiological characterization of lateral line function in the Antarctic fish Trematomus bernacchii.

The Antarctic notothenioids are a monophyletic radiation of fishes that have evolved under conditions of low light and cold, where non-visual sensory systems, such as the mechanosensory lateral line system, would be of importance. As part of a study of the structure and function of the mechanosensory lateral line system in these fishes we systematically characterized the function of the anterior lateral line system in one of the common benthic species, Trematomus bernacchii. Frequency-response and threshold-tuning curve methods yield similar functional characterizations of single afferent fibre responses to vibrational stimulation. Curve fitting of generalized transfer function to frequency-response curves allows an objective splitting of responses into velocity and acceleration sensitive populations thought to correspond to superficial and canal neuromasts, respectively. Both response types are characterized by a low-pass frequency-response curve, with a relatively low upper frequency cut-off when compared with data from temperate species. The sensitivity of the lateral line system of T. bernacchii is comparable to that of the mottled sculpin Cottus bairdi.

Acceleration↗
PubMed1992

Fibers innervating different parts of the lateral line system of an Antarctic notothenioid, Trematomus bernacchii, have similar frequency responses, despite large variation in the peripheral morphology.

Regional differences in the architecture and size of lateral line canals and neuromasts were measured in an Antarctic fish, Trematomus bernacchii, and the data were used in models of canal and cupular mechanics to predict the frequency response of these two peripheral structures. These modeled predictions were then compared to frequency response functions measured with single unit recording techniques from anterior and posterior lateral line fibers innervating different canals on the head and trunk of fish of various sizes. Despite large variations in the peripheral morphology of head and trunk canals in fish of different sizes, lateral line fibers were relatively homogeneous in their frequency response properties. In response to stimuli of equal pk-pk acceleration levels, all canal neuromast fibers responded with equal and maximum responsiveness in the 10-45 Hz range, after which responsiveness fell off at about 18 dB/octave. Whereas the biomechanical models of cupular and canal responsiveness predicted the region of equal and maximum responsiveness in the 10-45 Hz range, they did not predict the high frequency cutoff nor the slope. Rather, these models predicted responsiveness out to at least 540 Hz, and a high frequency slope of 12 dB/octave. In terms of the frequency response of peripheral fibers, we conclude that (1) there can be considerable morphological variability, with little consequence for function, as long as some minimum standards for maintaining constant acceleration responsiveness in the 10-45 Hz range are met, and (2) there must be additional filters between the cupula and primary afferent fibers.

Acceleration↗
PubMed1982

Winter range utilization of a Japanese macaque troop in a snowy habitat.

The winter range utilization pattern of a Japanese macaque troop in a snowy habitat was studied. The vegetation areas essential for subsistence were found to be relatively undisturbed mixed and deciduous forests. The concept of essential resource area (ERA) is defined. Our comparison among three troops in the same habitat in the past and present with different population densities indicated that the per capita ERA is quite important in determining the range area. This implies that the population and range area are resource-correlated.

Animals↗
PubMed1988

Falls, elderly women and the cold.

In a prospective study of falls in 761 subjects 70 years and over an increase in the rate of falls in winter was observed in women but not men. When the daily minimum temperature fell to 1 degrees C or less the relative risk of falling in women increased to 1.53 (95% confidence intervals 1.21-1.84). We discuss measures to decrease this seasonal increase in the rate of falls.

Accidental Falls↗
PubMed1987

Psychological and interpersonal issues in space.

As future manned space missions become longer, and as crews become more heterogeneous, psychological and interpersonal factors will take on increasing importance in assuring mission success. On the basis of a review of more than 60 American and Soviet space simulation studies on Earth, along with reports from U.S. and Soviet space missions, the author identifies nine psychological and seven interpersonal issues, which are discussed along with pertinent research findings and examples from manned spaceflights. He concludes that more psychological and interpersonal research should be done under actual spaceflight conditions and offers suggestions.

Adaptation, Psychological↗
PubMed1994

Effect of prostaglandin E1 analogue administration on peripheral skin temperature at high altitude.

The effect of prostaglandin E1 analogue on peripheral skin temperature was examined at high altitude, where local cold injuries are common owing to severe environmental conditions. The peripheral skin temperature at rest was significantly lower at higher altitudes. Oral administration of the prostaglandin E1 analogue limaprost reversed this temperature decrease, probably by enhancement of peripheral circulation. The temperature recovery rate after a cold water challenge was also improved after the administration of limaprost. This oral type of prostaglandin E1 analogue is strongly recommended as an effective prophylactic and therapeutic vasodilator for local cold injuries at high altitudes.

Adult↗