Les parcs agraires - reflet de l’histoire du peuplement

En général, les recherches sur l’histoire du peuplement en Afrique occidentale sont basées sur des traditions orales et les différents archives. Mais les recherches archéobotaniques montrent que la végétation peut également fournir des informations précieuses. Se servir de la végétation actuelle pour mieux comprendre l’histoire du peuplement d’une région est une nouvelle approche non-narrative. Le sujet de cette présentation sont les populations d'arbres utiles sur des terrains soit actuellement, soit récemment exploités: les parcs agraires ou agroforestiers

Das Überweidungsproblem in der westafrikanischen Savanne : neue Ansätze und Perspektiven

Die weidewirtschaftliche Nutzung beeinflußt seit Jahrtausenden den Natur- und Kulturraum der westafrikanischen Savanne. Die Beweidung durch die verschiedenen domestizierten Tierarten hat in diesem Zeitraum einen wesentlichen Einfluß auf die Entwicklung der Vegetationszusammensetzung gehabt und das vor allem in der Krautschicht. Übermäßige Beweidung kann - wie zahlreiche Untersuchungen zeigen - zu einschneidenden Veränderungen in der Pflanzendecke führen, die letztlich in einer völligen Zerstörung der Vegetation gipfeln können. Dieser Prozess wird landläufig als Überweidung bezeichnet und gilt als eine der wesentlichen Ursachen für Landschaftsschäden. Die in den letzten Dekaden ständig anwachsenden Tierbestände in Afrika südlich der Sahara haben die Situation weiter verschärft. Folgerichtig konzentrieren sich Meliorationsvorschläge auf eine Verringerung der Besatzdichte auf ein tragfähiges Maß. Angestrebt wird ein geregeltes Weidemanagement, das eine nachhaltige Bewirtschaftung der natürlichen Ressourcen ermöglicht. Trotz teilweise jahrzehntelanger Bestrebungen konnte dieses Ziel bis dato nicht erreicht werden, so daß in jüngerer Zeit Fachwissenschaftler zu der Überzeugung gekommen sind, daß diese Mißerfolge bereits auf Fehler in den grundlegenden Überlegungen zurückzuführen sind. Die aus diesen neuen Überlegungen resultierenden Modellvorstellungen in der Weideökologie sollen an dieser Stelle vorgestellt werden. Dabei wird vor allem auf die Problematik der Beurteilung und Bewertung des Überweidungsprozesses eingegangen

Natural environment and land use in the Chad Basin, NE-Nigeria : preliminary results of an interdisciplinary research

The objective of this paper is to combine the environmental conception of the Kanuri with detailed findings of pedological and botanical field investigations. Interpretation of multitemporal satellite data and aerial photographs should provide land cover and land use information for an extended area. The area of investigation was outlined within the transitional zone from the clay plains to the sandy areas by interpretation of satellite images. The presented subset of a SPOT-XS-satellite image shows part of the Marte Local Government Area with its capital Old Marte in the north-eastern part of the image. The darker colours represent the clay plains while the lighter parts are related to the sandy areas. Almost half of the research area is covered by clay but all settlements are located on the slightly elevated sandy areas. Within these sandy areas different gray shades demonstrate the pattern of the rainy season farming area. Differences in colour within the clay plains are mainly due to variances in soil, water content and vegetation cover. In the north-eastern part of the image irrigation channels of the South Chad Irrigation Project are visible. The main attention, especially of the pedological and botanical research, was directed towards the south-western part of the subset in the vicinity of the villages of Wulwa, Dura, Kajere and Ngubdori

Étapes de l'histoire du peuplement dans la région de l'Atakora

Pendants les années 1997 et 1998, un groupe des chercheurs de SFB 268 a effectué, dans la région de l’Atakora, des recherches botaniques, ethnologiques et géographiques concernant l’histoire du peuplement. Les travaux étaient concentrés sur la partie ouest de la région, c’est-à-dire le triangle Boukombé, Natitingou, Toucountouna. En résultat, il est possible aujourd’hui de faire une chronologie relative à l’histoire du peuplement dans cette région. En contraire, il manque toujours une chronologie absolue, pour cela il faut encore des recherches approfondies. Pourtant nous allons proposer, dans le cours de cette contribution, des hypothèses montrant le cadre, dans lequel une périodisation peut être possible

Les terroirs et la végétation : paradigmes d’exploitation du sol chez les Mosi et les Bisa dans la province de Boulgou

Le sujet principal des recherches interdisciplinaire G3 est la comparaison des stratégies d’exploitation du sol de deux différentes ethnies, dans un environnement identique ou presque identique. La province de Boulgou au sud-est du Burkina Faso semble être qualifiée pour ce type de recherches. Ici deux représentants des deux groupes linguistiques et culturels les plus importants - les groupes des Gur et Mande - sont directement avoisinants. Il s’agit des Mosi et des Bisa

Counteracting incentive sensitization in severe alcohol dependence using deep brain stimulation of the nucleus accumbens: clinical and basic science aspects

The ventral striatum / nucleus accumbens has been implicated in the craving for drugs and alcohol which is a major reason for relapse of addicted people. Craving might be induced by drug-related cues. This suggests that disruption of craving-related neural activity in the nucleus accumbens may significantly reduce craving in alcohol-dependent patients. Here we report on preliminary clinical and neurophysiological evidence in three male patients who were treated with high frequency deep brain stimulation of the nucleus accumbens bilaterally. All three had been alcohol dependent for many years, unable to abstain from drinking, and had experienced repeated relapses prior to the stimulation. After the operation, craving was greatly reduced and all three patients were able to abstain from drinking for extended periods of time. Immediately after the operation but prior to connection of the stimulation electrodes to the stimulator, local field potentials were obtained from the externalized cables in two patients while they performed cognitive tasks addressing action monitoring and incentive salience of drug related cues. LFPs in the action monitoring task provided further evidence for a role of the nucleus accumbens in goal-directed behaviors. Importantly, alcohol related cue stimuli in the incentive salience task modulated LFPs even though these cues were presented outside of the attentional focus. This implies that cue-related craving involves the nucleus accumbens and is highly automatic

The Higgs as a Portal to Plasmon-like Unparticle Excitations

12 LaTeX pages, 2 figures.-- Published in: JHEP04(2008)028.-- Final full-text version available at: http://dx.doi.org/10.1088/1126-6708/2008/04/028.A renormalizable coupling between the Higgs and a scalar unparticle operator O_U of non-integer dimension d_U<2 triggers, after electroweak symmetry breaking, an infrared divergent vacuum expectation value for O_U. Such IR divergence should be tamed before any phenomenological implications of the Higgs-unparticle interplay can be drawn. In this paper we present a novel mechanism to cure that IR divergence through (scale-invariant) unparticle self-interactions, which has properties qualitatively different from the mechanism considered previously. Besides finding a mass gap in the unparticle continuum we also find an unparticle pole reminiscent of a plasmon resonance. Such unparticle features could be explored experimentally through their mixing with the Higgs boson.Work supported in part by the European Commission under the European Union through the Marie Curie Research and Training Networks “Quest for Unification” (MRTN-CT- 2004-503369) and “UniverseNet” (MRTN-CT-2006-035863); by the Spanish Consolider- Ingenio 2010 Programme CPAN (CSD2007-0042); by a Comunidad de Madrid project (P-ESP-00346) and by CICYT, Spain, under contracts FPA 2007-60252 and FPA 2005-02211

DNA methylation-based classification of central nervous system tumours.

Accurate pathological diagnosis is crucial for optimal management of patients with cancer. For the approximately 100 known tumour types of the central nervous system, standardization of the diagnostic process has been shown to be particularly challenging-with substantial inter-observer variability in the histopathological diagnosis of many tumour types. Here we present a comprehensive approach for the DNA methylation-based classification of central nervous system tumours across all entities and age groups, and demonstrate its application in a routine diagnostic setting. We show that the availability of this method may have a substantial impact on diagnostic precision compared to standard methods, resulting in a change of diagnosis in up to 12% of prospective cases. For broader accessibility, we have designed a free online classifier tool, the use of which does not require any additional onsite data processing. Our results provide a blueprint for the generation of machine-learning-based tumour classifiers across other cancer entities, with the potential to fundamentally transform tumour pathology

Research needs in allergy: an EAACI position paper, in collaboration with EFA

Abstract In less than half a century, allergy, originally perceived as a rare disease, has become a major public health threat, today affecting the lives of more than 60 million people in Europe, and probably close to one billion worldwide, thereby heavily impacting the budgets of public health systems. More disturbingly, its prevalence and impact are on the rise, a development that has been associated with environmental and lifestyle changes accompanying the continuous process of urbanization and globalization. Therefore, there is an urgent need to prioritize and concert research efforts in the field of allergy, in order to achieve sustainable results on prevention, diagnosis and treatment of this most prevalent chronic disease of the 21 st century. The European Academy of Allergy and Clinical Immunology (EAACI) is the leading professional organization in the field of allergy, promoting excellence in clinical care, education, training and basic and translational research, all with the ultimate goal of improving the health of allergic patients. The European Federation of Allergy and Airways Diseases Patients&apos; Associations (EFA) is a non-profit network of allergy, asthma and Chronic Obstructive Pulmonary Disorder (COPD) patients&apos; organizations. In support of their missions, the present EAACI Position Paper, in collaboration with EFA, highlights the most important research needs in the field of allergy to serve as key recommendations for future research funding at the national and European levels. Although allergies may involve almost every organ of the body and an array of diverse external factors act as triggers, there are several common themes that need to be prioritized in research efforts. As in many other chronic diseases, effective prevention, curative treatment and accurate, rapid diagnosis represent major unmet needs. Detailed phenotyping/endotyping stands out as widely required in order to arrange or re-categorize clinical syndromes into more coherent, uniform and treatment-responsive groups. Research efforts to unveil the basic pathophysiologic pathways and mechanisms, thus leading to the comprehension and resolution of the pathophysiologic complexity of allergies will allow for the design of novel patient-oriented diagnostic and treatment protocols. Several allergic diseases require well-controlled epidemiological description and surveillance, using disease registries, pharmacoeconomic evaluation, as well as large biobanks. Additionally, there is a need for extensive studies to bring promising new biotechnological innovations, such as biological agents, vaccines of modified allergen molecules and engineered components for allergy diagnosis, closer to clinical practice. Finally, particular attention should be paid to the difficult-to-manage, precarious and costly severe disease forms and/or exacerbations. Nonetheless, currently arising treatments, mainly in the fields of immunotherapy and biologicals, hold great promise for targeted and causal management of allergic conditions. Active involvement of all stakeholders, including Patient Organizations and policy makers are necessary to achieve the aims emphasized herein