scholarly journals Winter huddling groups in the striped mouse

2006 ◽  
Vol 84 (5) ◽  
pp. 693-698 ◽  
Author(s):  
C. Schradin ◽  
M. Schubert ◽  
N. Pillay
Keyword(s):  
Heat Loss ◽  
Small Body ◽  
Group Living ◽  
High Heat ◽  
Severe Drought ◽  
Succulent Karoo ◽  
Winter Rainfall ◽  
Rhabdomys Pumilio ◽  
Save Energy ◽  
Family Groups

Huddling is a strategy to avoid heat loss and thus save energy and is often observed in birds and rodents, which, because of their small body size, are prone to relatively high heat loss. Huddling might thus explain group-living in some cases, such as the winter huddling groups described for several northern hemisphere rodents. Here we describe winter huddling groups in an African rodent, the striped mouse ( Rhabdomys pumilio (Sparrman, 1784)), from the Succulent Karoo of South Africa. Striped mice were radio-tracked and observed directly in the field. The importance of huddling in this species was demonstrated by comparing data collected over 2 years. The 2003 winter was characterized by a severe drought and 99% mortality. As a result, close kin were mainly unavailable and striped mice slept in non-kin huddling groups. In 2004, normal winter rainfall occurred, mortality was only 50%, and striped mice formed family groups that shared a nest at night. While family groups were stable in 2004, non-kin huddling groups in 2003 were highly flexible and often changed from night to night. Huddling groups are important for striped mice to save energy, and the instability of non-kin sleeping groups indicates that the potential for conflict is higher between non-kin than between kin and that there is a trade-off between thermoregulatory requirements and kin selection.

scholarly journals Identification of Quantitative Trait Loci Influencing Traits Related to Energy Balance in Selection and Inbred Lines of Mice

Genetics ◽  
1999 ◽  
Vol 152 (2) ◽  
pp. 699-711 ◽  
Author(s):  
D E Moody ◽  
D Pomp ◽  
M K Nielsen ◽  
L D Van Vleck
Keyword(s):  
Quantitative Trait Loci ◽  
Energy Balance ◽  
Heat Loss ◽  
Quantitative Trait ◽  
Subcutaneous Fat ◽  
High Heat ◽  
Chromosome 1 ◽  
Direct Calorimetry ◽  
Resource Population ◽  
Trait Loci

Abstract Energy balance is a complex trait with relevance to the study of human obesity and maintenance energy requirements of livestock. The objective of this study was to identify, using unique mouse models, quantitative trait loci (QTL) influencing traits that contribute to variation in energy balance. Two F2 resource populations were created from lines of mice differing in heat loss measured by direct calorimetry as an indicator of energy expenditure. The HB F2 resource population originated from a cross between a noninbred line selected for high heat loss and an inbred line with low heat loss. Evidence for significant QTL influencing heat loss was found on chromosomes 1, 2, 3, and 7. Significant QTL influencing body weight and percentage gonadal fat, brown fat, liver, and heart were also identified. The LH F2 resource population originated from noninbred lines of mice that had undergone divergent selection for heat loss. Chromosomes 1 and 3 were evaluated. The QTL for heat loss identified on chromosome 1 in the HB population was confirmed in the LH population, although the effect was smaller. The presence of a QTL influencing 6-wk weight was also confirmed. Suggestive evidence for additional QTL influencing heat loss, percentage subcutaneous fat, and percentage heart was found for chromosome 1.

scholarly journals Mejora del rendimiento térmico de los edificios históricos "difíciles de tratar" en el centro de Edimburgo = Improving The Thermal Performance of "Hard-to-Treat" Historic Buildings in Edinburgh’s New Town.

2016 ◽  
Vol 2 (1) ◽  
pp. 26 ◽  
Author(s):  
Julio Bros Williamson ◽  
Jon Stinson ◽  
Alasdair Reid ◽  
John Currie
Keyword(s):  
Heat Loss ◽  
Energy Efficient ◽  
Solid Wall ◽  
Housing Association ◽  
High Heat ◽  
World Heritage Site ◽  
Low Carbon ◽  
New Town ◽  
Heritage Site ◽  
Unesco World Heritage Site

Resumen Compuestos alternativos en el sector de la envolvente se obtienen por extrusión de estirado de secciones y perfiles de panel de enclavamiento estrechas. Estos elementos estructurales, resistentes al impacto, tienen la ventaja de una instalación más rápida y segura, y su diseño modular les hace idóneos para muchos edificios y otras aplicaciones. Un desarrollo adicional en esta área puede ser la obtención de una alternativa sostenible a los perfiles compuestos actuales. Estudios anteriores han demostrado que los compuestos fabricados a partir de materiales naturales tales como fibras y polímeros bio-derivados, ofrecen una alternativa sostenible a los polímeros y materiales compuestos tradicionales. El objetivo de este desarrollo es reemplazar el típico perfil de acero ligero. Los perfiles de acabado también se pueden utilizar para terminar tabiques de mampostería existentes, revestimiento de ejes mecánicos y de extracción y revestimiento de la columna. Los perfiles se han diseñado utilizando bio-polímeros, reforzados con fibras naturales. Se han establecido los parámetros de procesamiento y las formulaciones apropiadas de bioresina y fibras naturales. También se ha evaluado la adaptación de las técnicas de procesamiento de pultrusión existentes a las características concretas de los nuevos biomateriales y fibras naturales. Como resultado, los perfiles de pultrusión adaptados a la construcción se han desarrollado con la incorporación de nuevos materiales y biomateriales basados en resina. Abstract This paper documents an innovative partnership project between Historic Scotland, the Scottish Energy Centre at Edinburgh Napier University and Castle Rock Edinvar Housing Association in which five Category B Listed, traditional pre-1919, solid wall ‘hard-to-treat’ residential tenement properties located within Edinburgh’s historic UNESCO World Heritage site each received energy efficient upgrades to walls and windows. A variety of measures were tested, achieving significant reductions in fabric heat loss without impacting upon the character and appearance of the buildings. The project is significant in that the energy-efficient upgrades all met with strict conservation requirements on alterations to Listed Buildings and have the potential to be replicated in similar properties throughout Scotland. The project won the award for best refurbishment project at the Carbon Trust’s Low Carbon Building Awards in 2012. All of the properties featured in this study are occupied by tenants within the social-rented sector who prior to the study had indicated some thermal discomfort due to poor window conditions and high heat loss through walls causing increase fuel consumption. The occupants all remained in their homes during the refurbishment activities. 

Temperature regulation in the new-born lamb. V. Summit metabolism

1962 ◽  
Vol 13 (1) ◽  
pp. 100 ◽  
Author(s):  
G Alexander
Keyword(s):  
Metabolic Rate ◽  
Heat Loss ◽  
Rectal Temperature ◽  
Prolonged Exposure ◽  
High Heat ◽  
Practical Significance ◽  
Body Temperatures ◽  
Prolonged Fasting ◽  
Body Weights ◽  
Summit Metabolic Rate

"Summit metabolism" was estimated by measuring respiratory exchange during a 20 min period of falling rectal temperature. The rate of fall was controlled at about 1°C per 20 min, by varying the wind velocity while the lamb was exposed to conditions of high heat loss. At body temperatures near normal, summit metabolism was not predictable from rectal temperature. Below 36°C the metabolic rate was proportional to rectal temperature. When expressed as kilocalories per kilogram per hour, summit metabolism in young lambs was approximately constant at all body weights, and hence summit, metabolism per unit of surface area increased with increasing body weight. Heavy lambs are therefore able to maintain homeothermy under conditions of higher heat loss than light lambs. Summit metabolism was usually established at about 17 kcal kg-1 hr-1 within half an hour of birth, i.e. heat production increased rapidly to 15 times foetal levels or five times "basal" levels. There was no increase after ingestion of milk, and the summit metabolic rate appeared to decline slowly with advancing age. It also declined during prolonged exposure to cold and during prolonged fasting, particularly in very young lambs. Blood analyses indicated a great mobilization of fat and carbohydrate during exposure to conditions which evoked a summit response. The practical significance of these results is discussed.

Sleep on a high heat capacity mattress increases conductive body heat loss and slow wave sleep

2018 ◽  
Vol 185 ◽  
pp. 23-30 ◽  
Author(s):  
Kurt Kräuchi ◽  
Elisa Fattori ◽  
Alessandra Giordano ◽  
Maria Falbo ◽  
Antonella Iadarola ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Heat Loss ◽  
Slow Wave ◽  
Slow Wave Sleep ◽  
High Heat ◽  
Conductive Body ◽  
High Heat Capacity ◽  
Body Heat

scholarly journals Ambient temperature effects on stress-induced hyperthermia in Svalbard ptarmigan

2019 ◽  
Author(s):  
Andreas Nord ◽  
Lars P. Folkow
Keyword(s):  
Skin Temperature ◽  
Heat Loss ◽  
Thermal Environment ◽  
Core Body Temperature ◽  
High Heat ◽  
Handling Stress ◽  
Induced Hyperthermia ◽  
Heat Loss Rate ◽  
Cold Environments ◽  
Lower Temperature

ABSTRACTStress-induced hyperthermia (SIH) is commonly observed during handling in homeotherms. However, in birds, handling in cold environments typically elicits hypothermia. It is unclear whether this indicates that SIH is differently regulated in this taxon or if it is due to size, because body temperatures changes during handling in low temperature have only been measured in small birds ≤ 0.03 kg (that are more likely to suffer high heat loss when handled). We have, therefore, studied thermal responses to handling stress in the intermediate-sized (0.5-1.0 kg) Svalbard ptarmigan (Lagopus muta hyperborea) in 0°C and −20°C, in winter and spring. Handling caused elevated core body temperature, and peripheral vasoconstriction that reduced back skin temperature. Core temperature increased less and back skin temperature decreased more in −20°C than in 0°C, probably because of higher heat loss rate at the lower temperature. Responses were qualitatively consistent between seasons, despite higher body condition/insulation in winter and dramatic seasonal changes in photoperiod, possibly affecting stress responsiveness. Our study supports the notion that SIH is a general thermoregulatory reaction to acute stressors in endotherms, but also suggests that body size and thermal environment should be taken into account when evaluating this response in birds.

Acoustic response function equation for a T- burner with high heat loss.

AIAA Journal ◽  
1968 ◽  
Vol 6 (4) ◽  
pp. 741-742 ◽  
Author(s):  
GEORGE L. DEHORITY ◽  
H. B. MATHES
Keyword(s):  
Heat Loss ◽  
Response Function ◽  
High Heat ◽  
Acoustic Response

Performance Study of New Energy-Saving Gas Stove and its Optimization

2012 ◽  
Vol 424-425 ◽  
pp. 1249-1252
Author(s):  
Jin Hong Zhang ◽  
Xue Wei Dai ◽  
Miao Yang ◽  
Ning Xie ◽  
Ru Xin Zhang ◽  
...  
Keyword(s):  
Heat Loss ◽  
The Other ◽  
Environment Pollution ◽  
Economic Returns ◽  
Performance Study ◽  
Heat Leakage ◽  
Reduce Heat Loss ◽  
New Energy ◽  
Save Energy ◽  
Gas Efficiency

A novel gas stove is developed by upgrading the general home use gas stove, it can absorb heat loss when heating food, through analysis of its performance and optimized, the result shows that it can not only solve the problem of heat leakage, but also reduce the unnecessary temperature rise of kitchen. This will improve the gas efficiency when boil water to cook, meanwhile it can save energy indirectly and achieve good economic returns. It can improve the utilization of its natural gas, on the other hand, it can reduce heat loss and environment pollution, environmental and economical benefits.

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