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Aims: Experiments were designed to evaluate the potential of rumen-simulating conditions to reduce PrPSc levels. Methods and Results: Scrapie-positive brain material was incubated under rumen-simulating conditions. Time points were taken over a 24-h period and PrPSc levels were analysed by Western blot. No loss of PrPSc was observed over a 24-h time period. Conclusions: Our results indicate that a fully developed rumen fermentation does not provide significant protection against prion infection via the oral route. Developmental changes including senescence of immune system function or other developmental changes in the gastrointestinal tract are potential mechanisms by which relative bovine spongiform encephalopathy (BSE) susceptibility might vary with age. Significance and Impact of the Study: Epidemiology of the BSE outbreak in the United Kingdom indicates that younger animals were at higher risk of infection. The rumen undergoes pronounced developmental changes early in life, coinciding with the introduction of fibre into the diet. The timeframe of highest risk of infection overlaps the time in life prior to full rumen development. This work indicates that a fully developed rumen does not provide significant protection against prion infection via the oral route of infection. This result implicates other developmental changes that are responsible for the age-dependent susceptibility of cattle to BSE. [ABSTRACT FROM AUTHOR]

Birds and men impinged rather little on one another until recent times. I cannot, however, do more historically than very briefly note the key points which have brought ornithology to where it now stands, around the end of the second Millennium AD. This sets the immediate agenda for further development, to be conveniently considered under the nine main groupings using in our just completed compendious Birds of the Western Palearctic (Cramp 1977-1994). From this we pass on to review, equally summarily, the existing structure and institutions of ornithology, to learn what kinds of redevelopment are called for, nationally and internationally. The theme of this conference leads on to conservation. How can the advancing knowledge of birds best be applied to their effective conservation and to that of the biosphere and its biodiversity? Finally, how can we pursue our mission to communicate to the world our already rich knowledge of birds and their rewarding ways of life, so that the message is put to use in our too man-centred civilization? [ABSTRACT FROM AUTHOR]