La végétation des mares temporaires au Sénégal oriental

La végétation de quelques dépressions temporairement inondées par des eaux pluviales, sur les plateaux mal drainés du Sénégal oriental, dont le sol présente un horizon ferrallitique concrétionné imperméable, est analysée selon la méthode phytosociologique de BRAUN-BLANQUET. Une association aquatique à #Dopatrium senegalense (tabl. 1) occupe les eaux libres à fond rocheux. Les mares sont envahies par les hélophytes de l'association à #Oryza brachyantha (tabl. 2 : relevés 1-3) et par ceux de l'association à #Echinochloa callopus (tabl. 2 : relevés 4-9). Les sols gravillonnaires inondés peu de temps portent une association à #Cyperus pulchellus et #Bacopa hamiltoniana (tabl. 3 : relevés 1-6); #Parahyparrhenia annua et #Rhytachne triaristata croissent en peuplements denses, considérés comme des faciès particuliers de cette association (tabl. 3 : relevés 7-10). La ceinture de végétation la plus externe est souvent dominée par #Andropogon pseudapricus (tabl. 3 : relevé 11). L'analyse chorologique des tableaux relevés met en évidence le caractère essentiellement soudanien de cette végétation aquatique et palustre. (Résumé d'auteur

Evidence for Composite Cost Functions in Arm Movement Planning: An Inverse Optimal Control Approach

An important issue in motor control is understanding the basic principles underlying the accomplishment of natural movements. According to optimal control theory, the problem can be stated in these terms: what cost function do we optimize to coordinate the many more degrees of freedom than necessary to fulfill a specific motor goal? This question has not received a final answer yet, since what is optimized partly depends on the requirements of the task. Many cost functions were proposed in the past, and most of them were found to be in agreement with experimental data. Therefore, the actual principles on which the brain relies to achieve a certain motor behavior are still unclear. Existing results might suggest that movements are not the results of the minimization of single but rather of composite cost functions. In order to better clarify this last point, we consider an innovative experimental paradigm characterized by arm reaching with target redundancy. Within this framework, we make use of an inverse optimal control technique to automatically infer the (combination of) optimality criteria that best fit the experimental data. Results show that the subjects exhibited a consistent behavior during each experimental condition, even though the target point was not prescribed in advance. Inverse and direct optimal control together reveal that the average arm trajectories were best replicated when optimizing the combination of two cost functions, nominally a mix between the absolute work of torques and the integrated squared joint acceleration. Our results thus support the cost combination hypothesis and demonstrate that the recorded movements were closely linked to the combination of two complementary functions related to mechanical energy expenditure and joint-level smoothness

Flemish network on rare connective tissue diseases (CTD): patient pathways in systemic sclerosis. First steps taken.

peer reviewedDespite the low prevalence of each rare disease, the total burden is high. Patients with rare diseases encounter numerous barriers, including delayed diagnosis and limited access to high-quality treatments. In order to tackle these challenges, the European Commission launched the European Reference Networks (ERNs), cross-border networks of healthcare providers and patients representatives. In parallel, the aims and structure of these ERNs were translated at the federal and regional levels, resulting in the creation of the Flemish Network of Rare Diseases. In line with the mission of the ERNs and to ensure equal access to care, we describe as first patient pathways for systemic sclerosis (SSc), as a pilot model for other rare connective and musculoskeletal diseases. Consensus was reached on following key messages: 1. Patients with SSc should have multidisciplinary clinical and investigational evaluations in a tertiary reference expert centre at baseline, and subsequently every three to 5 years. Intermediately, a yearly clinical evaluation should be provided in the reference centre, whilst SSc technical evaluations are permissionably executed in a centre that follows SSc-specific clinical practice guidelines. In between, monitoring can take place in secondary care units, under the condition that qualitative examinations and care including interactive multidisciplinary consultations can be provided. 2. Patients with early diffuse cutaneous SSc, (progressive) interstitial lung disease and/or pulmonary arterial hypertension should undergo regular evaluations in specialised tertiary care reference institutions. 3. Monitoring of patients with progressive interstitial lung disease and/or pulmonary (arterial) hypertension will be done in agreement with experts of ERN LUNG

L'extraction du sel en Basse-Casamance (Sénégal) et les effets de cette industrie traditionnelle sur la formation des paysages

Salt extraction in Lower Casamance (Southern Senegal) and the results of this traditional activity upon the landscape. — Salt extraction by ancestral process is described. Salty soil is first leached. Salt crystals are obtained by ebullition of the brackish extract. The result of this practice on soil and vegetation is quantitatively estimated.Description et fonctionnement des ateliers traditionnels d'extraction du sel, en Basse-Casamance, à partir de l'horizon superficiel des sols salés. Evaluation des effets, certainement importants, de cette activité artisanale sur la dénudation des terres salées en lisière de la mangrove.Vanden Berghen C. L'extraction du sel en Basse-Casamance (Sénégal) et les effets de cette industrie traditionnelle sur la formation des paysages. In: Journal d'agriculture traditionnelle et de botanique appliquée, 31ᵉ année, bulletin n°3-4, Juillet-décembre 1984. pp. 235-244