Past and future global transformation of terrestrial ecosystems under climate change.

Impacts of global climate change on terrestrial ecosystems are imperfectly constrained by ecosystem models and direct observations. Pervasive ecosystem transformations occurred in response to warming and associated climatic changes during the last glacial-to-interglacial transition, which was comparable in magnitude to warming projected for the next century under high-emission scenarios. We reviewed 594 published paleoecological records to examine compositional and structural changes in terrestrial vegetation since the last glacial period and to project the magnitudes of ecosystem transformations under alternative future emission scenarios.

Waxing and waning of forests: Late Quaternary biogeography of southeast Africa.

African ecosystems are at great risk. Despite their ecological and economic importance, long-standing ideas about African forest ecology and biogeography, such as the timing of changes in forest extent and the importance of disturbance, have been unable to be tested due to a lack of sufficiently long records. Here, we present the longest continuous terrestrial record of late Quaternary vegetation from southern Africa collected to date from a drill core from Lake Malawi covering the last ~600,000 years.

Vegetation controls on weathering intensity during the last deglacial transition in southeast Africa.

Tropical climate is rapidly changing, but the effects of these changes on the geosphere are unknown, despite a likelihood of climatically-induced changes on weathering and erosion. The lack of long, continuous paleo-records prevents an examination of terrestrial responses to climate change with sufficient detail to answer questions about how systems behaved in the past and may alter in the future. We use high-resolution records of pollen, clay mineralogy, and particle size from a drill core from Lake Malawi, southeast Africa, to examine atmosphere-biosphere-geosphere interactions during the last deglaciation (∼ 18-9 ka), a period of dramatic temperature and hydrologic changes.

[Complement factor I deficiency revealed by repeated systemic Streptococcus pneumoniae infection].

Recurrent and serious otitis media, and 2 Streptococcus pneumoniae bacteraemia episodes evoked an immune system deficiency in a 6-year-old girl. Upon investigation of the complement system, CH50 activity was moderately reduced and C4 antigen level was normal contrasting with low C3 antigen level. Factor 1 was undetectable.

[Ghosal haematodiaphyseal dysplasia: a new case].

Ghosal-type hematodiaphyseal dysplasia has been first described in 1986, as a steroid-dependent anemia with endosteal broadening of the long bone's diaphyses and metaphaphyses, which makes a distinction with the periosteal reaction in Camuratti-Engelmann's disease and with Caffey's disease. Extreme pallor is first noticed and leads to search for palpable thick long bones that are not always clinically obvious. The transmission of this rare entity seems to be autosomal recessive, with a common racial background from the Middle East and the Indian subcontinent.