Factors affecting body temperatures of toads

Factors influencing levels and rates of variation of body temperature ( T b ) in montane Bufo boreas boreas and in lowland Bufo boreas halophilus were investigated as an initial step toward understanding the role of natural thermal variation in the physiology and energetics of these ectothermic animals. Body temperatures of boreas can vary 25–30° C over 24-h periods. Such variation is primarily due to both nocturnal and diurnal activity and the physical characteristics of the montane environment. Bufo boreas halophilus are primarily nocturnal except during breeding and are voluntarily active at body temperatures ranging between 10 and 25° C. Despite variation in T b encountered in the field, boreas select a narrow range of T b in a thermal gradient, averaging 23.5 and 26.2° C for fasted individuals maintained under field conditions or acclimated to 20° C, respectively. In a thermal gradient the mean T b of fasted halophilus acclimated to 20° C is 23.9° C. Skin color of boreas varies in the field from very dark to light. The dark skins absorb approximately 4% more radiation than the light ones. Light colored boreas should absorb approximately 5% more radiation than similarly colored halophilus . Evaporative water losses increase directly with skin temperatures and vapor pressure deficit in both subspecies. Larger individuals heat and cool more slowly than smaller ones. Calculation of an enery budget for boreal toads suggests that they could sit in direct sunlight for long periods without fatally overheating, providing the skin was continually moist.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47722/1/442_2004_Article_BF00344732.pd

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Dehydration and drinking behavior in true sea snakes (Elapidae: Hydrophiinae: Hydrophiini))

Water is an essential resource affecting behavior and the acquisition of energy, especially in environments where water is spatially or temporally restricted or unavailable. Recent investigations have shown that several species of marine snakes dehydrate at sea and are dependent on environmental sources of fresh water to maintain water balance. However, in this context, little is known concerning the majority of 'true' sea snakes (Hydrophiini). We investigated the dehydration and drinking responses of five species of hydrophiin sea snakes collected during the dry season in northern Australia. None of these snakes drank sea water, even when dehydrated. Dehydrated individuals of Hydrophis curtus, H. elegans and H. zweifeli drank fresh water, and the mean threshold levels of dehydration that first elicited drinking were deficits of −26, −29 and −27% of body mass, respectively. Individuals of Aipysurus mosaicus and H. peronii did not drink fresh water when similarly dehydrated. Few snakes that we collected following >4 months of drought drank fresh water immediately after capture. Hydrophiin species appear to have a high resistance to dehydration, which they evidently tolerate in marine habitats for extended periods during drought. Thirst in these species is significantly less sensitive than in other species, suggesting that marine snakes have variable requirements for drinking fresh water. These data illustrate that sea snakes are characterized by diverse responses to dehydration and likely have different osmoregulatory strategies for survival, with implications for better understanding the evolutionary success of secondarily marine vertebrates and their potential responses to future changes in tropical precipitation