Impact de la fabrication de charbon de bois sur la production et la disponibilité fourragère de pâturage en zone subaride, cas de la commune de Soalara-Sud, Toliara ll: Rapport final

Ce projet a pour objectif de (1) décrire la filière charbon dans un terroir de la commune de Soalara, (2) d’identifier les effets des activités de fabrication de charbon de bois sur la végétation des pâturages qui est un fourré épineux et (3) d’estimer la quantité maximale de charbon pouvant être produite sans causer sa dégradation irréversible. Pour ce faire, des enquêtes auprès de la population locale et des relevés écologiques ont été entrepris. La majorité des ménages enquêtés (>80% ; N=56) pratiquent la fabrication de charbon de bois. Environ 41 000 sacs de charbons ont été produits dans le terroir en 2009. L’impact socio-économique de la filière charbon est positif puisqu’elle génère des revenus importants pour ses agents (producteur, transporteur et collecteur). Par contre, l’impact écologique est plutôt négatif puisque les activités charbonnières contribuent à réduire la densité d’arbres et d’arbustes de la végétation des fourrés épineux et sa richesse spécifique même si elles n’affectent pas trop sa disponibilité fourragère. De plus, la quantité de charbon produite (environ 820 t en 2009) dépasse la productivité de la végétation, estimée à 218 t.an-1. Par conséquent, une dégradation du site de production actuel, se traduisant par la disparition des espèces charbonnières, arriverait dans 17 ans au plus tard, si le rythme de production actuel continue. Des mesures de réduction des pressions sur la végétation (professionnalisation des éleveurs, amélioration des rendements de carbonisation et réglementation et contrôle plus strict de la filière charbon) et d’augmentation de sa production et productivité (restauration) doivent être prises pour éviter cette dégradation irréversible qui à terme pourrait être dommageable à l’élevage de petits ruminants même si ce n’est pas encore le cas actuellement.

The M-theory origin of global properties of gauge theories

We show that global properties of gauge groups can be understood as geometric properties in M-theory. Different wrappings of a system of N M5-branes on a torus reduce to four-dimensional theories with AN−1 gauge algebra and different unitary groups. The classical properties of the wrappings determine the global properties of the gauge theories without the need to impose any quantum conditions. We count the inequivalent wrappings as they fall into orbits of the modular group of the torus, which correspond to the S-duality orbits of the gauge theories.

Glucagonlike peptide-1 receptor: an example of translational research in insulinomas: a review

Glucagonlike peptide-1 receptors (GLP-1R) play an increasingly important role in endocrine gastrointestinal tumor management. In particular, virtually all benign insulinomas express GLP-1R in high density. Exendin-4 is a GLP-1 analog that has a longer half-life than GLP-1. Targeting GLP-1R by (111)In-DOTA-exendin-4 or (111)In-DPTA-exendin-4 offers a new approach that permits the successful localization of small benign insulinomas. It is likely that this new noninvasive technique has the potential to replace the invasive localization by selective arterial stimulation and venous sampling.

The effects of PTK787/ZK222584, an inhibitor of VEGFR and PDGFR? pathways, on intussusceptive angiogenesis and glomerular recovery from Thy1.1 nephritis

The aim of our study was to investigate the phenomenon of intussusceptive angiogenesis with a focus on its molecular regulation by vascular endothelial growth factor receptor (VEGFR)/platelet-derived growth factor receptor β (PDGFRβ) pathways and biological significance for glomerular recovery after acute injury. Glomerular healing by intussusception was examined in a particular setting of Thy1.1 nephritis, where the lysis of mesangial cells results in an initial collapse and successive rebuilding of glomerular capillary structure. Restoration of capillary structure after induction of Thy1.1 nephritis occurred by intussusceptive angiogenesis resulting in i) rapid expansion of the capillary plexus with reinstatement of the glomerular filtration surface and ii) restoration of the archetypical glomerular vascular pattern. Glomerular capillaries of nephritic rats after combined VEGFR2 and PDGFRβ inhibition by PTK787/ZK222584 (PTK/ZK) were tortuous and irregular. However, the onset of intussusceptive angiogenesis was influenced only after long-term PTK/ZK treatment, providing an important insight into differential molecular regulation between sprouting and intussusceptive angiogenesis. PTK/ZK treatment abolished α-smooth muscle actin and tensin expression by injured mesangial cells, impaired glomerular filtration of microspheres, and led to the reduction of glomerular volume and the presence of multiple hemorrhages detectable in the tubular system. Collectively, treatment of nephritic patients with PTK/ZK compound is not recommended.

The Bernese Hypothermia Algorithm: a consensus paper on in-hospital decision-making and treatment of patients in hypothermic cardiac arrest at an alpine level 1 trauma centre

INTRODUCTION: Guidelines for the treatment of patients in severe hypothermia and mainly in hypothermic cardiac arrest recommend the rewarming using the extracorporeal circulation (ECC). However,guidelines for the further in-hospital diagnostic and therapeutic approach of these patients, who often suffer from additional injuries—especially in avalanche casualties, are lacking. Lack of such algorithms may relevantly delay treatment and put patients at further risk. Together with a multidisciplinary team, the Emergency Department at the University Hospital in Bern, a level I trauma centre, created an algorithm for the in-hospital treatment of patients with hypothermic cardiac arrest. This algorithm primarily focuses on the decision-making process for the administration of ECC. THE BERNESE HYPOTHERMIA ALGORITHM: The major difference between the traditional approach, where all hypothermic patients are primarily admitted to the emergency centre, and our new algorithm is that hypothermic cardiac arrest patients without obvious signs of severe trauma are taken to the operating theatre without delay. Subsequently, the interdisciplinary team decides whether to rewarm the patient using ECC based on a standard clinical trauma assessment, serum potassium levels, core body temperature, sonographic examinations of the abdomen, pleural space, and pericardium, as well as a pelvic X-ray, if needed. During ECC, sonography is repeated and haemodynamic function as well as haemoglobin levels are regularly monitored. Standard radiological investigations according to the local multiple trauma protocol are performed only after ECC. Transfer to the intensive care unit, where mild therapeutic hypothermia is maintained for another 12 h, should not be delayed by additional X-rays for minor injuries. DISCUSSION: The presented algorithm is intended to facilitate in-hospital decision-making and shorten the door-to-reperfusion time for patients with hypothermic cardiac arrest. It was the result of intensive collaboration between different specialties and highlights the importance of high-quality teamwork for rare cases of severe accidental hypothermia. Information derived from the new International Hypothermia Registry will help to answer open questions and further optimize the algorithm.

Redox-Switching in a Viologen-type Adlayer: An Electrochemical Shell-Isolated Nanoparticle Enhanced Raman Spectroscopy Study on Au(111)-(1 x 1) Single Crystal Electrodes

We reported the first application of in situ shell-isolated nanoparticle enhanced Raman spectroscopy (SHINERS) to an interfacial redox reaction under electrochemical conditions. We construct gap-mode sandwich structures composed of a thiol-terminated HS-6V6H viologen adlayer immobilized on a single crystal Au(111)-(1x1) electrode and covered by Au(60 nm)@SlO(2) core shell nanoparticles acting as plasmonic antennas. We observed high-quality, potential-dependent Raman spectra of the three viologen species V(2+),V(+center dot) and V(0) on a well-defined Au(111) substrate surface and could map their potential-dependent evolution. Comparison with experiments on powder samples revealed an enhancement factor of the nonresonant Raman modes of similar to 3 x 10(5), and up to 9 x 10(7) for the resonance modes. The study illustrates the unique capability of SHINERS and its potential in the entire field of electrochemical surface science to explore structures and reaction pathways on well-defined substrate surfaces, such as single crystals, for molecular, (electro-)- catalytic, bioelectrochemical systems up to fundamental double layer studies at electrified solid/liquid interfaces.

An Actor-Critic based controller for glucose regulation in type 1 diabetes

A novel adaptive approach for glucose control in individuals with type 1 diabetes under sensor-augmented pump therapy is proposed. The controller, is based on Actor-Critic (AC) learning and is inspired by the principles of reinforcement learning and optimal control theory. The main characteristics of the proposed controller are (i) simultaneous adjustment of both the insulin basal rate and the bolus dose, (ii) initialization based on clinical procedures, and (iii) real-time personalization. The effectiveness of the proposed algorithm in terms of glycemic control has been investigated in silico in adults, adolescents and children under open-loop and closed-loop approaches, using announced meals with uncertainties in the order of ±25% in the estimation of carbohydrates. The results show that glucose regulation is efficient in all three groups of patients, even with uncertainties in the level of carbohydrates in the meal. The percentages in the A+B zones of the Control Variability Grid Analysis (CVGA) were 100% for adults, and 93% for both adolescents and children. The AC based controller seems to be a promising approach for the automatic adjustment of insulin infusion in order to improve glycemic control. After optimization of the algorithm, the controller will be tested in a clinical trial.