Plant migration and plant communities at the time of the "Green Sahara"

Around 8500 cal years BP, at the time of the maximum of the African Humid Period, lakes and wetlands expanded in the present-day Sahara while large paleodrainages were formed or re-actived, in response to an orbitally-induced increase in monsoon rainfall. It has been suggested that the direct consequence of this increase in rainfall was the northward displacement of the Sahara/Sahel boundary, thought to have reached 23 degrees N in central and eastern Africa. Here, we show a more complex situation characterized by an increase in biodiversity as the desert accommodated more humid-adapted species from tropical forests and wooded grasslands: tropical plant species now found some 400 to 500 km to the south probably entered the desert as gallery-forest formations along rivers and lakes where they benefited from permanent fresh water. At the same time, Saharan trees and shrubs persisted, giving rise to a vegetation that has no analogue today. In this article, we present distribution maps of selected plant species to show both the amplitude of the vegetation change compared to the present and the composition of the past plant communities. We also estimate the migration rate of tropical plant taxa. to their northernmost position in the Sahara. This study is based on the use of several data sets: a data set of the modern plant distribution in northern Africa and a data set of modem and fossil pollen sites (from the African Pollen Database, http://fpd.mediasfrance.org/ and http://medias.obs-mip.fr/apd/). To cite this article: J. Watrin et al., C R. Geoscience 341 (2009). (C) 2009 Published by Elsevier Masson SAS on behalf of Academie des sciences

Recommandations sur la gestion du risque et la prise en charge urologique du patient adulte atteint de dysraphisme spinal (spina bifida)

International audienceIntroduction: Improved life expectancy and prenatal screening have changed the demographics of spina bifida (spinal dysraphism) which has presently become a disease of adulthood. Urinary disorders affect almost all patients with spinal dysraphism and are still the leading cause of mortality in these patients. The aim of this work was to establish recommendations for urological management that take into account the specificities of the spina bifida population. Materials and methods: National Diagnosis and Management Guidelines (PNDS) were drafted within the framework of the French Rare Diseases Plan at the initiative of the Centre de Référence Maladies Rares Spina Bifida - Dysraphismes of Rennes University Hospital. It is a collaborative work involving experts from different specialties, mainly urologists and rehabilitation physicians. We conducted a systematic search of the literature in French and English in the various fields covered by these recommendations in the MEDLINE database. In accordance with the methodology recommended by the authorities (Guide_methodologique_pnds.pdf, 2006), proposed recommendations were drafted on the basis of this literature review and then submitted to a review group until a consensus was reached. Results: Bladder dysfunctions induced by spinal dysraphism are multiple and varied and evolve over time. Management must be individually adapted and take into account all the patient's problems, and is therefore necessarily multi-disciplinary. Self-catheterisation is the appropriate micturition method for more than half of the patients and must sometimes be combined with treatments aimed at suppressing any neurogenic detrusor overactivity (NDO) or compliance alteration (anticholinergics, intra-detrusor botulinum toxin). Resort to surgery is sometimes necessary either after failure of non-invasive treatments (e.g. bladder augmentation in case of NDO resistant to pharmacological treatment), or as a first line treatment in the absence of other non-invasive alternatives (e.g. aponeurotic suburethral tape or artificial urinary sphincter for sphincter insufficiency; urinary diversion by ileal conduit if self-catheterisation is impossible). Conclusion: Spinal dysraphism is a complex pathology with multiple neurological, orthopedic, gastrointestinal and urological involvement. The management of bladder and bowel dysfunctions must continue throughout the life of these patients and must be integrated into a multidisciplinary context

African pollen database inventory of tree and shrub pollen types

African pollen data have been used in many empirical or quantitative palaeoenvironmental reconstructions. However, the pollen types used in these studies were not controlled and standardised, preventing the precise understanding of pollen-plant and pollen-climate relation that is necessary for the accurate quantification of continental scale climate change or ecological processes in the past. This paper presents a summary of the progress made with the African Pollen Database (APD) inventory of plant diversity from pollen data extracted from 276 fossil sites and more than 1500 modem samples, with a focus on tropical tree pollen types. This inventory (1145 taxa) gives, for each pollen taxon whose nomenclature is discussed, information on the habit, habitat and phytogeographical distribution of the plants they come from. Special attention has been paid to pollen types with similar morphology, which include several plant species or genera, whose biological or environmental parameters can differ considerably