We quantify the locomotor capacity of the round-tailed ground squirrel (Spermophilus tereticaudus), a mammal that can lower energetic costs by relaxing thermoregulatory limits without becoming inactive. We measured maximum sprint speed, maximum limb cycling frequency and maximum force production in animals at body temperatures ranging from 31 degrees C to 41 degrees C. We found no thermal dependence in any of these parameters of locomotion.
View Article and Find Full Text PDFThis study quantifies the thermoregulatory ability and energetics of a mammal, the round-tailed ground squirrel Spermophilus tereticaudus, that can relax thermoregulatory limits without becoming inactive. We measured body temperature and metabolic rate in animals exposed for short periods (1 h) to air temperatures ranging from 10 to 45 degrees C and for long periods (8 h) to air temperatures ranging from 10 to 30 degrees C. Within 45 min of exposure to air temperatures ranging from 10 to 45 degrees C, the mean body temperatures of alert and responsive animals ranged from 32.
View Article and Find Full Text PDFTo understand better how complex interactions between environmental variables affect the energy balance of small diurnal animals, we studied the effects of the absence and presence of 950 W m(-)(2) simulated solar radiation combined with wind speeds ranging from 0. 25 to 1.00 m s(-)(1) on the metabolic rate and body temperature of the round-tailed ground squirrel Spermophilus tereticaudus.
View Article and Find Full Text PDFThe energy budgets of small endotherms are profoundly affected by characteristics of the physical environment such as wind speed, air temperature and solar radiation. Among these, solar radiation represents a potentially very large heat load to small animals and may have an important influence on their thermoregulatory metabolism and heat balance. In this investigation, we examined the interactive effects of wind speed and irradiance on body temperature, thermoregulatory metabolism and heat balance in the white-crowned sparrow (Zonotrichia leucophrys gambelii).
View Article and Find Full Text PDFThe present work demonstrates utilization of electron beam irradiation for the treatment of Kaposi's sarcoma when the full circumference of the lower calf is involved, and when the deep lymphatics are negative for disease. The finite penetration of the electron beam spares deep tissue, preventing the edema associated with photon total limb irradiation. The number of fields with fall-off required to produce a uniform dose to a cylindrical anatomic structure was studied by calculating dose distributions resulting from two-, four-, and six-field techniques for a 5-MeV electron beam and a 9 cm diameter cylinder.
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