Energy partitioning in torpor-sensitive and torpor-resistant deer mice (Peromyscus maniculatus)

1996 ◽  
Vol 74 (7) ◽  
pp. 1179-1186 ◽  
Author(s):  
Brandon A. Sheafor ◽  
Gregory K. Snyder

We examined metabolic rates in 25 deer mice, Peromyscus maniculatus nebrascensis, held at an ambient temperature of 10 °C and found that all of them had the ability to enter torpor. However, we found a gradation between the most torpor-sensitive and the most torpor-resistant animals, suggesting that the expression of torpor is more than a simple all-or-nothing phenomenon. On a daily basis, the most torpor-sensitive and torpor-resistant mice partition energy similarly when food is not restricted. On restricted food, both groups of mice decrease the amount of time spent active and increase the amount of time spent at rest and in torpor. In addition, both groups of mice decrease oxygen-consumption rates and body temperatures during rest and the most torpor-sensitive mice further decrease energy costs by entering longer and deeper bouts of torpor. However, the overall energy saving due to torpor is only about 6%. Thus, the widely held view that the adaptive advantage of daily torpor is a large energy saving may be open to question. Alternatively, daily torpor may be important for reducing the rate of energy turnover when these small rodents must rely on body fat reserves.

1974 ◽  
Vol 52 (11) ◽  
pp. 1311-1315 ◽  
Author(s):  
J. Harling ◽  
R. M. F. S. Sadleir

The frequency distribution of over 600 stomach weights of deer mice showed considerable variation and was highly skewed. Because of the difficulty of defining a "full" stomach, it was not possible to use the weights of stomachs sampled to estimate consumption rates. There were no significant seasonal changes in mean stomach weights over a 3-year study and no relationship between stomach weights and sexual condition was found.


1997 ◽  
Vol 70 (1) ◽  
pp. 61-67 ◽  
Author(s):  
James R. Nestler ◽  
Stacy J. Peterson ◽  
B. David Smith ◽  
R. Brian Heathcock ◽  
Christina R. Johanson ◽  
...  

2000 ◽  
pp. 347-353 ◽  
Author(s):  
James Nestler ◽  
Tiffany Lingenfelter ◽  
Gary Gonthier ◽  
Jenee Gifford ◽  
Stacy Peterson

2018 ◽  
Vol 131 (3) ◽  
pp. 238-245 ◽  
Author(s):  
Karen J. Vanderwolf ◽  
David Malloch ◽  
Donald F. McAlpine

With the exception of recent work on bats, no reports on the fungi present on live mammals in underground habitats have been published. We cultured psychrotolerant fungi from the external surface and faeces of live Deer Mice (Peromyscus maniculatus), and from the intestinal contents of a single freshly killed P. maniculatus, overwintering in a white-nose syndrome positive bat hibernaculum and from adjacent summer forest in eastern Canada. A low diversity of psychrotolerant fungi was cultured from P. maniculatus compared with that found in previous studies of the mycoflora of bats and arthropods occupying bat hibernacula in the region. Although the grooming habits of P. maniculatus may reduce the accumulation of a diverse psychrotolerant fungal assemblage on their external surface, we demonstrate that active euthermic mammals in underground habitats can carry viable spores of psychrotolerant fungi, both externally and internally. Small rodents using cave habitats may also play a role in dispersing psychrotolerant fungi between caves and suitable low-temperature habitats (i.e., burrows) in adjacent forest.


1996 ◽  
Vol 77 (1) ◽  
pp. 147-154 ◽  
Author(s):  
J. R. Nestler ◽  
G. R. Dieter ◽  
B. G. Klokeid

Author(s):  
Marat R. Lukmanov ◽  
◽  
Sergey L. Semin ◽  
Pavel V. Fedorov ◽  
◽  
...  

The challenges of increasing the energy efficiency of the economy as a whole and of certain production sectors in particular are a priority both in our country and abroad. As part of the energy policy of the Russian Federation to reduce the specific energy intensity of enterprises in the oil transportation system, Transneft PJSC developed and implements the energy saving and energy efficiency improvement Program. The application of energy-saving technologies allowed the company to significantly reduce operating costs and emissions of harmful substances. At the same time, further reduction of energy costs is complicated for objective reasons. The objective of this article is to present additional methods to improve the energy efficiency of oil transportation by the example of the organizational structure of Transneft. Possibilities to reduce energy costs in the organization of the operating services, planning and execution of work to eliminate defects and preparatory work for the scheduled shutdown of the pipeline, the use of pumping equipment, including pumps with variable speed drive, the use of various pipelines layouts, changing the volume of oil entering the pipeline system and increase its viscosity.


1989 ◽  
Vol 264 (10) ◽  
pp. 5593-5597
Author(s):  
C Norsten ◽  
T Cronholm ◽  
G Ekström ◽  
J A Handler ◽  
R G Thurman ◽  
...  

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