RESUMO
Recent lichen surveys in the foreland of The Syterbäcken glacier reveal that the crustose lichens, principally species of Rhizocarpon section Rhizocarpon, exhibit marginal bleaching, readily distinguishable from normal pigmented forms. The largest elliptical thallus of Rhizocarpon measured 290 mm maximum diameter on a bedrock outcrop beyond the margin of Little Ice Age moraines in the upper Syterbäcken Valley. Many small and large thalli of Rhizocarpon suffered damage to the periphery of individual thalli. We examine here some of the possible hypotheses explaining these occurrences. Among others, these are bedrock lithology, ice crystal blasting, long-term snowbank cover, ultraviolet exposure and acid rain. While at this time none of the possibilities can be ruled out entirely, acid rain would appear to be at least one of the factors involved. Acid rain, which is known to produce a soil pH as low as 3.3 in the field area, appears to provide a high input of H(+) ions that the lichen algal component cannot withstand. However, the lack of similar effects on associated foliose or fruticose forms raises the possibility that perhaps two or more factors specific to the environment of Rhizocarpon are operating.
RESUMO
This study reports a consecutive series of 220 children and adolescents who sustained traumatic brain injury (BI) and were admitted to a comprehensive paediatric rehabilitation programme. Progress in areas of mobility, activities of daily living, education and cognitive function were documented for up to 3 years after the injury. Physical recovery was most rapid in the first years and cognitive and language gains generally occurred later, even up to 3 years after the injury. Cognitive assessment at the time of admission proved helpful in predicting outcome; of those patients admitted in a conscious state only one remained dependent for any aspect of self care. Even for those admitted unconscious at a median of 62 days after injury there was good potential for recovery with 27-43 per cent achieving independence in the activities of daily living. For those still unconscious at 6 months, 72 per cent remained vegetative and none achieved the highest cognitive level. Overall, 14 per cent returned to regular education while 25 per cent remained incapable of any educational programme. In a well planned and multidisciplinary rehabilitation programme, patients with severe BI have potential for continued recovery and measurable improvement for at least 3 years. The emphasis should be targeted on differing areas of the therapy programme at different phases of recovery. A realistic appraisal of the ultimate potential for recovery can usually be made by 6 months.
