Many attempts to predict the biotic responses to climate change rely on the 'climate envelope' approach, in which the current distribution of a species is mapped in climate-space and then, if the position of that climate-space changes, the distribution of the species is predicted to shift accordingly. The flaw in this approach is that distributions of species also reflect the influence of interactions with other species, so predictions based on climate envelopes may be very misleading if the interactions between species are altered by climate change. An additional problem is that current distributions may be the result of sources and sinks, in which species appear to thrive in places where they really persist only because individuals disperse into them from elsewhere. Here we use microcosm experiments on simple but realistic assemblages to show how misleading the climate envelope approach can be. We show that dispersal and interactions, which are important elements of population dynamics, must be included in predictions of biotic responses to climate change.

No abstract

Address

A fifteen-month-old boy, born to consanguineously married couple, presented with asymptomatic hepatomegaly. Investigations revealed mildly deranged liver functions, necroinflammatory changes and cirrhosis on liver biopsy, a markedly raised alpha feto protein and tyrosine levels in plasma and a generalized aminoaciduria. His diagnosis of hereditary tyrosinemia was established on findings of raised serum and urine succinylacetone and a deficient activity of fumaryl acetoacetate hydroxylase enzyme. Prenatal diagnosis of hereditary tyrosinemia was performed in a subsequent pregnancy in this family from India.

— The impact of computer-assisted learning (CAL) packages on the use of animals in university teaching has been investigated in universities in the UK and abroad. The pilot study has focused on two issues: a) academic staff perceptions of the usability of CAL packages designed to offer an alternative to animal practicals in physiology and pharmacology; and b) whether the use of such programs has led to a reduction in the number of animals used. A questionnaire survey of purchasers of a minimum of three commercially available programs, which offer an alternative approach to traditional laboratory experiments, was conducted. The study found that in most departments the packages were used in a staff-supervised learning situation, to either replace or support a practical class. Their use saved academic and non-academic staff time, and they were considered to be less expensive and an effective and enjoyable mode of student learning. It was also clear that their use had contributed to a significant reduction in animal use.