Feeding status and basking requirements of freshwater turtles in an invasion context.

Thermoregulatory behavior and feeding status are strongly related in ectotherms. A trade-off between maintenance of energy balance and digestion efficiency has been recently proposed to affect thermoregulation in these animals. On the other hand, competition for basking sites has been described between Iberian turtles and the introduced red-eared slider (Trachemys scripta elegans). T. scripta negatively interferes with basking behavior of native turtles and benefits from a greater capacity to retain body heat, which may likely result in thermoregulatory advantages for the introduced sliders. Consequently, complex effects and alterations in metabolic rates of native turtles might derive from a deficient basking behavior. We compared the basking requirements of the endangered native Spanish terrapin (Mauremys leprosa) and those of the introduced red-eared slider, analyzing the upper set point temperature (USP) (defined as the body temperature at which basking ceased) of both native and introduced turtles, under feeding and fasting conditions. We found higher values of USP in the native species, and a reduction of this temperature associated with food deprivation in the two turtle species. This adjustment of thermoregulatory behavior to the nutritional status found in freshwater turtles suggests that ectotherms benefit from metabolic depression as an adaptive mechanism to preserve energy during periods of fasting. However, a reduction in metabolic rates induced by competition with sliders might lead M. leprosa to a prolonged deficiency of their physiological functions, thus incurring increased predation risk and health costs, and ultimately favoring the recession of this native species in Mediterranean habitats.

Socioeconomic, environmental, and behavioural risk factors for leprosy in North-east Brazil: results of a case-control study.

BACKGROUND: Brazil reports almost 80% of all leprosy cases in the Americas. This study aimed to identify socioeconomic, environmental, and behavioural factors associated with risk of leprosy occurrence in the endemic North-eastern region. METHODS: A case-control study in four municipalities. CASES: cases of leprosy diagnosed in the previous 2 years, with no other known, current, or past case of leprosy in the household or in the neighbourhood. CONTROLS: individuals presenting for reasons other than skin problems to the health unit where the case was diagnosed and who lived in the same municipality as the case with whom it was matched. For each case four controls were selected. A semi-structured questionnaire was used to collect demographic, socioeconomic, environmental, and behavioural data. A multivariate hierarchical analysis was performed according to a previously defined framework. RESULTS: 226 cases and 857 controls were examined. Low education level, ever having experienced food shortage, bathing weekly in open water bodies (creek, river and/or lake) 10 years previously, and a low frequency of changing bed linen or hammock (>or=biweekly) currently were all significantly associated with leprosy. Having a BCG vaccination scar was found to be a highly significant protective factor. CONCLUSIONS: Except for BCG vaccination, variables that remained significant in the hierarchical analysis are cultural or linked to poverty. They may act on different levels of the transmission of Mycobacterium leprae and/or the progress from infection to disease. These findings give credit to the hypothesis that person-to-person is not the only form of M. leprae transmission, and that indirect transmission might occur, and other reservoirs should exist outside the human body.

Health and husbandry considerations of induced molting.

There have been many methods proposed to induce molting. Some worked very well in practice, but others were detrimental to the health and welfare of the hens. The most effective methods use some level of feed restriction and daylength manipulation to reduce body weight (Hansen, 1966; Ruszler, 1974, 1984, 1996; Swanson and Bell, 1974; Brake and Carey, 1983). Weight reduction is necessary for rest and rejuvenation of body tissues. Other methods evaluated incorporated dietary imbalances using either zinc, iodine, or sodium. Pharmaceuticals have been used but have not been cost effective. In recent years there have been those who question whether molting techniques are humane. Therefore, interest has been heightened in alternate methods to induce molting. Research reported to date has been inadequate to accurately determine which methods of induced molting are the least stressful, if they in fact, cause any more stress than that experienced by the hen during a natural molt. The three or four most highly refined methods being used commercially are not generally detrimental to the health and welfare of today's laying hen, provided that they are managed in accordance with proper husbandry practices.