Evaluation et amélioration du comportement de Atriplex lentiformis (Torr.) S. Watson en milieux salés au Sénégal

La salinisation des sols constitue l’une des principales menaces à la  productivité agricole dans les zones estuariennes du Sénégal. La mycorhization pourrait améliorer l’efficacité de la méthode biologique de désalinisation des sols. Atriplex lentiformis associé ou non au champignon Rhizophagus irregulare a été observé en milieu réel, et en serre dans un dispositif bi-factoriel (mycorhization et salinité) en blocs complets randomisés avec 3 répétitions. Les variables mesurées sont la hauteur, le diamètre, la litière, la teneur en eau, en sodium des plants, la salinité et l’acidité du sol. Les résultats montrent un taux de mortalité supérieur à 90% en milieu réel. Les individus plantés sur ados ont développé un enracinement superficiel alors que les semis naturels ont présenté un système racinaire pivotant et profond. La mycorhization a entraîné une réduction de la mortalité de 5,56%, une importante persistance des feuilles, une teneur en eau plus élevée dans les tiges et racines que dans les feuilles et enfin un stockage de sodium plus élevé dans les feuilles. La dose de sel 186 g.l-1 a été létale pour Atriplex lentiformis, mycorhizé ou non. La symbiose endomycorhizienne améliore ainsi le comportement de Atriplex lentiformis en milieu salé.Mots clés : Atriplex lentiformis, mycorhization, salinité, stress, Sénégal

Dépistage du VIH en salle d’accouchement à la maternité du Centre de Santé de Référence de la commune V Bamako

Objectifs : Evaluer l’impact du counseling pour le dépistage VIH en salle de travail chez les patientes n’ayant pas bénéficié de cette activité lors des CPN. Méthodes et matériels : L’étude s’est déroulée au CSRéf de la commune v de Bamako du 1er janvier au 31décembre 2014. L’échantillonnage était systématique, portait sur toutes les parturientes admises en salle de travail avec une dilatation cervicale à 4cm ou plus et dans le post- partum immédiat avec un âge gestationnel ≥ 28SA ou un poids fœtal ≥1000g. Le test par bandelette a été utilisé après consentement éclairé des patientes .La confirmation a été faite avec l’immunocomb II VIH1 et 2 Bi spot. Résultats :L’étude a rapporté que 4,34% (380) des parturientes n’ont pas fait le dépistage VIH lors du suivi prénatal. En salle d’accouchement, ces 380 parturientes ont bénéficié toutes d’un conseil dépistage volontaire au VIH. Nous avons enregistré 11 cas de refus. Sur les 369 parturientes ayant fait le test, 37 étaient positifs au VIH soit 10%. L’âge moyen était de 27ans ±07 ; non instruite (58,9%) vivant dans un régime polygamique (65,9) ; un suivi prénatal fait (95,12%) ; 93% suivi dans les structures citées PTME. Les antirétroviraux ont été administrés à toutes les mères et aux nouveau- nés vivants. Conclusion : Au regard de la fréquence élevée (10%) des cas positifs dans notre étude, il est nécessaire de poursuivre les activités de Conseil et Dépistage Volontaire en salle d’accouchement pour permettre à l’ensemble des femmes enceintes qui accouchent dans nos structures sanitaires de bénéficier des interventions de la PTM

Disrupted structural connectivity of fronto-deep gray matter pathways in progressive supranuclear palsy

Background: Structural connectivity is a promising methodology to detect patterns of neural network dysfunction in neurodegenerative diseases. This approach has not been tested in progressive supranuclear palsy (PSP). Objectives: The aim of this study is reconstructing the structural connectome to characterize and detect the pathways of degeneration in PSP patients compared with healthy controls and their correlation with clinical features. The second objective is to assess the potential of structural connectivity measures to distinguish between PSP patients and healthy controls at the single-subject level. Methods: Twenty healthy controls and 19 PSP patients underwent diffusion-weighted MRI with a 3T scanner. Structural connectivity, represented by number of streamlines, was derived from probabilistic tractography. Global and local network metrics were calculated based on graph theory. Results: Reduced numbers of streamlines were predominantly found in connections between frontal areas and deep gray matter (DGM) structures in PSP compared with controls. Significant changes in structural connectivity correlated with clinical features in PSP patients. An abnormal small-world architecture was detected in the subnetwork comprising the frontal lobe and DGM structures in PSP patients. The classification procedure achieved an overall accuracy of 82.23% with 94.74% sensitivity and 70% specificity. Conclusion: Our findings suggest that modelling the brain as a structural connectome is a useful method to detect changes in the organization and topology of white matter tracts in PSP patients. Secondly, measures of structural connectivity have the potential to correctly discriminate between PSP patients and healthy controls

An Electrochemical Study of Frustrated Lewis Pairs: A Metal-free Route to Hydrogen Oxidation

[Image: see text] Frustrated Lewis pairs have found many applications in the heterolytic activation of H(2) and subsequent hydrogenation of small molecules through delivery of the resulting proton and hydride equivalents. Herein, we describe how H(2) can be preactivated using classical frustrated Lewis pair chemistry and combined with in situ nonaqueous electrochemical oxidation of the resulting borohydride. Our approach allows hydrogen to be cleanly converted into two protons and two electrons in situ, and reduces the potential (the required energetic driving force) for nonaqueous H(2) oxidation by 610 mV (117.7 kJ mol(–1)). This significant energy reduction opens routes to the development of nonaqueous hydrogen energy technology

Universal contributions to scalar masses from five dimensional supergravity

We compute the effective Kahler potential for matter fields in warped compactifications, starting from five dimensional gauged supergravity, as a function of the matter fields localization. We show that truncation to zero modes is inconsistent and the tree-level exchange of the massive gravitational multiplet is needed for consistency of the four-dimensional theory. In addition to the standard Kahler coming from dimensional reduction, we find the quartic correction coming from integrating out the gravity multiplet. We apply our result to the computation of scalar masses, by assuming that the SUSY breaking field is a bulk hypermultiplet. In the limit of extreme opposite localization of the matter and the spurion fields, we find zero scalar masses, consistent with sequestering arguments. Surprisingly enough, for all the other cases the scalar masses are tachyonic. This suggests the holographic interpretation that a CFT sector always generates operators contributing in a tachyonic way to scalar masses. Viability of warped su- persymmetric compactifications necessarily asks then for additional contributions. We discuss the case of additional bulk vector multiplets with mixed boundary conditions, which is a partic- ularly simple and attractive way to generate large positive scalar masses. We show that in this case successful fermion mass matrices implies highly degenerate scalar masses for the first two generations of squarks and sleptons.Comment: 23 pages. v2: References added, new section on effect of additional bulk vector multiplets and phenomenolog

Study of the electro-oxidation of a recreational drug GHB (gamma hydroxybutyric acid) on a platinum catalyst-type electrode through chronoamperometry and spectro-electrochemistry

The electro-oxidation of gamma-hydroxybutyric acid (GHB) on a polycrystalline platinum electrode in acidic medium has been studied using chronoamperometry. The study has been performed in a wide interval of potentials and at different concentrations. It was found that at longer times the density currents reached stationary values at more anodic potentials, whereas it is zero at lower potentials. These characteristics in the j-t curves suggest a different mechanism for the electro-oxidation of GHB, potential dependent, with a catalytic process at high potentials and an adsorption process controlled by mass transport at low potential. The change in the stationary current obtained at +0.9 V with variable GHB concentrations also suggests an oxidation mechanism catalysed by the platinum surface with platinum hydroxides acting as reaction intermediates to make the final oxidation product for GHB. The results obtained using chronoamperometry are in good agreement with those obtained using cyclic voltammetry where the alcohol group is oxidised at different potentials. In situ Surface Enhanced Raman Scattering (SERS) spectra corresponding to GHB intermediates and water adsorbed species being formed/consumed at the potentialdependent adsorption processes have been analyzed using spectro-electrochemistry. A peak at 1590 cm-1, corresponding to the asymmetric stretching of carboxylic group in a bridge configuration, increases with the potential. This supports the hypothesis of a mechanism of formation of the succinic acid on the platinum surface as reaction product under the experimental conditions studied

Hepatoprotective effect of commercial herbal extracts on carbon tetrachloride-induced liver damage in Wistar rats

Background: The antioxidant and anti-inflammatory effects of arbutin protect against a number of diseases. Objectives: The present study evaluated the protective effect of arbutin against carbon tetrachloride (CCl4)-induced hepatotoxicity in rats. Methods: Sixty-three Wistar rats were divided into nine groups. Groups I and II were the normal control groups. Group III, the hepatotoxic group, was given CCl4. Groups IV, VI, and VIII received different dosages of arbutin along with CCl4. Groups V, VII, and IX were administered different dosages of arbutin. The albumin content, total protein, and bilirubin were assayed to determine their serum and antioxidant levels; lipid peroxidation was assessed in the serum and liver tissue. Histological studies were carried out to confirm the biochemical results. Results: Treatment with CCl4 for 28 d decreased the levels of total protein and albumin and increased the level of bilirubin and lipid peroxidation. Arbutin treatment raised the level of albumin and lowered the lipid peroxidation to normal levels. Necrosis and fibrosis were observed in the liver tissue of CCl4-injected rats, and the administration of arbutin had a protective effect on the liver tissue. Conclusions: The results of this study showed that arbutin may protect the liver against CCl4-induced oxidative damage in rats. This hepatoprotective effect might be correlated with the antioxidant and free radical scavenger effects of arbutin

Strong fisheries management and governance positively impact ecosystem status

Bundy, Alida ... et al.-- 28 pages, 6 figures, 8 tables, supporting information https://dx.doi.org/10.1111/faf.12184Fisheries have had major negative impacts on marine ecosystems, and effective fisheries management and governance are needed to achieve sustainable fisheries, biodiversity conservation goals and thus good ecosystem status. To date, the IndiSeas programme (Indicators for the Seas) has focussed on assessing the ecological impacts of fishing at the ecosystem scale using ecological indicators. Here, we explore fisheries ‘Management Effectiveness’ and ‘Governance Quality’ and relate this to ecosystem health and status. We developed a dedicated expert survey, focused at the ecosystem level, with a series of questions addressing aspects of management and governance, from an ecosystem-based perspective, using objective and evidence-based criteria. The survey was completed by ecosystem experts (managers and scientists) and results analysed using ranking and multivariate methods. Results were further examined for selected ecosystems, using expert knowledge, to explore the overall findings in greater depth. Higher scores for ‘Management Effectiveness’ and ‘Governance Quality’ were significantly and positively related to ecosystems with better ecological status. Key factors that point to success in delivering fisheries and conservation objectives were as follows: the use of reference points for management, frequent review of stock assessments, whether Illegal, Unreported and Unregulated (IUU) catches were being accounted for and addressed, and the inclusion of stakeholders. Additionally, we found that the implementation of a long-term management plan, including economic and social dimensions of fisheries in exploited ecosystems, was a key factor in successful, sustainable fisheries management. Our results support the thesis that good ecosystem-based management and governance, sustainable fisheries and healthy ecosystems go togetherThis is a contribution to the IndiSeas Working Group, which, by the time of the study, was cofunded by IOC-UNESCO (www.ioc-unesco.org), EuroMarine (http://www.euromarinenetwork.eu), the European FP7 MEECE research project, the European Network of Excellence Eur-Oceans and the FRB EMIBIOS project (contract n°212085)Peer Reviewe