Sex differences in habitat use (habitat segregation) are widespread in sexually dimorphic ungulates. A possible cause is that males are more sensitive to weather than females, leading to sex differences in sheltering behaviour (the ‘weather sensitivity hypothesis’). However, this hypothesis has never been tested. We considered the allometric rates of net energy gain during times of cold weather and food shortage in a model. We argue that the higher absolute heat losses relative to intake rates of larger ungulates should indeed lead to higher weather sensitivity in males than in females. Furthermore, we tested the weather sensitivity hypothesis empirically in red deer, Cervus elaphus, on the Isle of Rum, U.K. We predicted that (1) use of relatively exposed, high-quality forage habitat should be negatively influenced by bad weather; and (2) this influence should be stronger in males. We found that bad weather (strong wind, low temperature, heavy rain) in winter and spring influenced use of high-quality forage habitat negatively in all deer; that adult males responded more strongly to low temperature and strong wind than did females; and that adult males foraged on windy days at better sheltered sites than did females. Thus, the weather sensitivity hypothesis is supported both theoretically and empirically. We suggest that the weather sensitivity hypothesis can potentially explain winter habitat segregation in a large number of ungulate species.
Maciej F. Boni and colleagues propose deploying multiple first-line combination therapies against malaria within a community to delay drug-resistance evolution.
This review examines whether the comprehensive programme recommended by the Global Initiative for Chronic Obstructive Lung Disease (GOLD), developed mostly by physicians in industrialised countries, can be applied in developing countries. In developing countries, there are several major limitations to the implementation of the programme. First, management of chronic obstructive pulmonary disease (COPD) patients is not a priority in competing for health care resources. Second, only major medical centres in developing countries have spirometers; the reliance on spirometric testing for diagnosis, staging and treatment options, as recommended by the GOLD guidelines, makes it almost impossible for the programme to be implemented. Third, in many Asian and African countries, regular monitoring is often restricted to patients with severe COPD who have frequent hospitalisations or clinic visits for exacerbations and complications. Fourth, the choice of therapy usually depends on the availability and cost of drugs. Finally, given the aetiological role of sequelae of lung infections, including tuberculosis, the appropriateness and safety of using intermittent courses of oral steroids during acute exacerbations and of long-term, high-dose inhaled corticosteroids for moderate to severe COPD in developing countries has not been evaluated. Developing countries in Asia and Africa may need to adapt the GOLD guidelines according to varying aetiology, local health care resources, socio-economic and cultural factors and development of health services. Prevention programmes, especially for tobacco control, are of paramount importance. National and international efforts must be directed towards controlling the tobacco epidemic in developing countries to reduce the burden of COPD and other tobacco-induced diseases.
In a survey of all 2069 in-patients at 14 geriatric centres, 249 patients were found to have received drugs for the treatment of parkinsonism. There was a wide variation in point prevalence which varied from 4.6% to 22.6% between centres. Levodopa, usually in combination with a.decarboxy lase inhibitor, was the most frequently prescribed drug. Compared with the recommendations for its use in Parkinson's disease, over 75% of patients received inadequate and widely spaced doses.Furthermore, dopamine antagonists were concurrently prescribed to one-third of patients who received levodopa. There was a high incidence of treatment failure (30%), and a low incidence of drug-induced dyskinesia (3%). Dementia was closely associated with the onset of parkinsonism. These findings suggest that many of these patients did not have Parkinson's disease but rather rigid-akinetic syndromes associated with degenerative brain disease. The treatment of parkinson ism in the elderly requires revaluation.
Deletions of chromosome 20q are associated with myeloid malignancies and have been previously shown to arise in a multipotent progenitor of both myeloid and B cells. However, B‐cell differentiation from the abnormal progenitor was impaired. The CD40 antigen is a surface glycoprotein which is expressed in B cells and haemopoietic stem cells and is important for B‐cell growth and development. Following the recent mapping of CD40 to chromosome 20q we sought to determine its position relative to 20q deletions. Analysis of lymphoblastoid cell lines carrying 20q deletions placed CD40 within a 19–21 cM interval which is almost coincidental with the common deleted region defined by previous analysis of patient samples. Our results raise the possibility that genetic alteration of this locus may contribute to the pathogenesis of myeloid disorders associated with 20q deletions.
