Seasonality of torpor patterns and physiological variables of a free-ranging subtropical bat

Seasonal changes in weather and food availability differ vastly between temperate and subtropical climates, yet knowledge on how free-ranging subtropical insectivorous bats cope with such changes is limited. We quantified ambient temperatures, torpor patterns and thermal physiology of subtropical insectivorous northern long-eared bats, Nyctophilus bifax, during summer (n=13) and winter (n=8) by temperature telemetry. As predicted, ambient conditions varied significantly between seasons, with warmer weather during summer. All bats used torpor on 85% of observation days during summer in comparison to 100% during winter. During summer, patterns of torpor varied and the duration of torpor bouts was not significantly affected by ambient temperature, whereas during winter torpor bout duration was negatively correlated with mean ambient temperature. Mean torpor bout duration in summer was 3.2+/-1.3 h and in winter was 26.8+/-11.3 h. Mean arousal time during summer was in the early afternoon and during winter in the late afternoon, and throughout both seasons arousals for possible foraging periods occurred near sunset. Skin temperature was positively correlated with ambient temperatures in both seasons, but the relationship differed between seasons. We show that torpor is used regularly throughout the year in a free-ranging subtropical bat and provide the first evidence demonstrating that torpor patterns and thermal physiology change with season.

Atypical presentation of childhood acquired immune deficiency syndrome mimicking Crohn's disease: nutritional considerations and management

A child with acquired immune deficiency syndrome became severely malnourished presumably as a result of multiple gastrointestinal infections, with numerous organisms including campylobacter, giardia, and cryptosporidium. These opportunistic infections preceded laboratory evidence of immune deficiency. Despite severe diarrhea and marked weight loss, there was no laboratory evidence of significant malabsorption. By using nasogastric feedings, we were successful in promoting a 60% weight gain, and a rise in serum albumin from 1.2 to 4.3 g/dl. While eventual outcome was not altered, this particular patient's clinical course was improved. We suggest that malnutrition should not be accepted as inevitable and that malabsorption should not be assumed in similar acquired immune deficiency syndrome patients. Appropriate studies for malabsorption should be done, and high caloric enteral feedings should be used whenever feasible.