scholarly journals The Adaptability of Mice to High Environmental Temperatures

1958 ◽  
Vol 35 (4) ◽  
pp. 892-901
Author(s):  
G. AINSWORTH HARRISON
Keyword(s):  
Survival Time ◽  
Heat Tolerance ◽  
Opposite Direction ◽  
Environmental Temperature ◽  
Lethal Temperature ◽  
F1 Hybrid ◽  
Hot Environment ◽  
Lower Heat ◽  
Environmental Temperatures ◽  
Hybrid Mice

1. C57xRIII F1 hybrid mice reared at 32° C. D.B., 29° C. W.B., from 3 to 8 weeks of age, survive longer at 41·7° C. D.B., 29·4° C. W.B., than litter-mates reared at 20° C. D.B., 16° C. W.B. 2. The transference of animals from the hot environment to the cooler one 48 hr. before they are exposed to the lethal temperature has little or no effect on their heat tolerance; but transference in the opposite direction greatly increases survival time. 3. Mice whose tails have been amputated 5 weeks before they are exposed to the lethal temperature have a lower heat tolerance than normal animals. 4. The total loss in weight of an animal exposed to the lethal temperature is independent of the environmental temperature at which it has been reared; but heat-acclimatized animals lose weight less rapidly than control ones. 5. It is concluded that at least some of the changes, both physiological and morphological, which occur when mice are reared at high temperatures, are in their over-all effect adaptive.

Upper lethal temperatures of the pelecypod Modiolus demissus in relation to declining environmental temperatures

1972 ◽  
Vol 50 (5) ◽  
pp. 523-527 ◽  
Author(s):  
D. L. Waugh
Keyword(s):  
Ambient Temperature ◽  
Environmental Temperature ◽  
Lethal Temperature ◽  
Winter Habitat ◽  
Lethal Temperatures ◽  
Thermal Acclimatization ◽  
Autumn And Winter ◽  
Environmental Temperatures ◽  
Accurate Reflection ◽  
Ribbed Mussel

Determinations of 24-h upper lethal temperatures of the ribbed mussel Modiolus demissus (Dillwyn) in relation to declining autumn and winter habitat temperatures show effective thermal acclimatization. Upper lethal temperatures ranged from 39.48 ± 0.33C to 37.67 ± 0.08C and the descending range of mean monthly environmental temperature was from 25C to −1.1C. Environmental and test salinity ranged from 28 to 30‰.The regression of lethal temperature on acclimatization temperature is significant when a direct correlation (concomitant) is made between ambient temperature and lethal temperature. Thus, current ambient temperature is an accurate reflection of acclimatization in this species.

Shorn and unshorn Awassi sheep I. Body temperature

1963 ◽  
Vol 60 (2) ◽  
pp. 159-168 ◽  
Author(s):  
E. Eyal
Keyword(s):  
Body Temperature ◽  
Relative Humidity ◽  
Heat Tolerance ◽  
Environmental Temperature ◽  
The Body ◽  
The Sun ◽  
Direct Sunlight ◽  
Ambient Temperatures ◽  
Awassi Sheep ◽  
Environmental Temperatures

1. The rectal temperatures of shorn and unshorn Awassi sheep were measured at various hours of the day and during various seasons of the year in two different locations in Israel.2. An increase in body temperature accompanied an increase in environmental temperature. A steeper temperature increase was noted in shorn sheep kept in the shade. When ambient temperatures were below 30° C. the body temperature of shorn sheep was lower than that of the unshorn sheep by an average of 0·16° C.3. When ambient temperatures were above 30° C. the body temperature of shorn sheep was equal to or higher than that of unshorn ones.4. Upon exposure to direct sunlight, the body temperature of shorn sheep exceeded that of unshorn animals. However, when the animals were transferred to the shade, or after sunset, the shorn sheep cooled at a faster rate. Their body temperature fell below that of the unshorn sheep during the cool hours of the day.5. Wind velocity, both in the shade and in the sun, had a greater effect on shorn than on unshorn sheep.6. A rise in the relative humidity of ambient temperatures above 25° C. caused body temperature to rise, particularly in unshorn animals. The body temperature of shorn sheep exceeded that of unshorn ones when the animals were maintained in a hot and dry environment.7. While the body of the shorn sheep was entirely affected by the macroclimate, the unshorn sheep were greatly influenced by the microclimate existing in the fleece. Fleece temperatures always lagged behind and were rarely equal to environmental temperatures. Since it was postulated that heat tolerance of certain animals was related to their ability to exploit cool hours of the day, it is suggested that in certain ‘tolerance tests’ records should be taken not only during exposure to heat but also during cool hours of the day.

Dealing with hot rocky environments: Critical thermal maxima and locomotor performance in Leptodactylus lithonaetes (Anura: Leptodactylidae)

2019 ◽  
pp. 155-161 ◽  
Author(s):  
Ivan Beltran
Keyword(s):  
Environmental Temperature ◽  
Extreme Temperature ◽  
Effect Of Temperature ◽  
Maximum Speed ◽  
Locomotor Performance ◽  
Extreme Temperatures ◽  
Physiological Limits ◽  
Fitness Consequences ◽  
Thermal Maximum ◽  
Environmental Temperatures

Environmental temperature has fitness consequences on ectotherm development, ecology and behaviour. Amphibians are especially vulnerable because thermoregulation often trades with appropriate water balance. Although substantial research has evaluated the effect of temperature in amphibian locomotion and physiological limits, there is little information about amphibians living under extreme temperature conditions. Leptodactylus lithonaetes is a frog allegedly specialised to forage and breed on dark granitic outcrops and associated puddles, which reach environmental temperatures well above 40 ˚C. Adults can select thermally favourable microhabitats during the day while tadpoles are constrained to rock puddles and associated temperature fluctuations; we thus established microhabitat temperatures and tested whether the critical thermal maximum (CTmax) of L. lithonaetes is higher in tadpoles compared to adults. In addition, we evaluated the effect of water temperature on locomotor performance of tadpoles. Contrary to our expectations, puddle temperatures were comparable and even lower than those temperatures measured in the microhabitats used by adults in the daytime. Nonetheless, the CTmax was 42.3 ˚C for tadpoles and 39.7 ˚C for adults. Regarding locomotor performance, maximum speed and maximum distance travelled by tadpoles peaked around 34 ˚C, approximately 1 ˚C below the maximum puddle temperatures registered in the puddles. In conclusion, L. lithonaetes tadpoles have a higher CTmax compared to adults, suggesting a longer exposure to extreme temperatures that lead to maintain their physiological performance at high temperatures. We suggest that these conditions are adaptations to face the strong selection forces driven by this granitic habitat.

The effects of environmental temperature and method of feeding on the performance and carcass composition of bacon pigs

1967 ◽  
Vol 9 (2) ◽  
pp. 209-218 ◽  
Author(s):  
D. W. Holme ◽  
W. E. Coey
Keyword(s):  
Environmental Temperature ◽  
Average Daily Gain ◽  
Carcass Composition ◽  
Restricted Feeding ◽  
Feed Conversion ◽  
Feeding Method ◽  
Feeding Regimes ◽  
Higher Temperature ◽  
Ad Libitum ◽  
Environmental Temperatures

A trial designed to investigate the effects of two environmental temperatures, three feeding regimes and the interactions between them is described. A temperature of 72° F. was better than one of 54° F. for bacon pigs between 40 lb. and 200 lb. weight. The higher temperature resulted in faster growth, more efficient feed conversion and increased length of carcass. Other carcass characteristics were not significantly altered. Ad libitum feeding resulted in faster growth and fatter carcasses than restricted feeding, but did not have a significant effect on efficiency of feed conversion. When feed intake was restricted, feeding pigs once daily or twice daily resulted in similar performance and carcass composition.There was a significant interaction between environmental temperature and feeding method for average daily gain in that pigs fed ad libitum grew faster at the low temperature and pigs fed restricted amounts of feed grew faster at the high temperature. No other interaction reached significant levels.

Intrastrain recurrent idiotypes among anti-DNA antibodies of (NZB X NZW)F1 hybrid mice

1982 ◽  
Vol 12 (9) ◽  
pp. 761-766 ◽  
Author(s):  
François Tron ◽  
Christian Le Guern ◽  
Pierre-André Cazenave ◽  
Jean-François Bach
Keyword(s):  
F1 Hybrid ◽  
Dna Antibodies ◽  
Hybrid Mice
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