Analyse par diffraction neutrons de la texture d’un acier industriel à faible pourcentage en carbone avant et après emboutissage

Résumé : Dans ce travail, une analyse de texture par diffraction neutrons avant et après déformation mécanique par le procédé d’emboutissage d’un acier faiblement allié et à faible pourcentage en carbone (0,19%) à été étudié, cet acier est destiné à la fabrication des réservoirs à gaz.          Pour réaliser notre objectif deux types de spécimens ont été investis, le premier concerne le métal de base à son état de livraison et le second après son passage à la presse sous une force de 200 tonnes soit après le procédé d’emboutissage. La fibre α et la fibre γ ont été clairement  identifiés ainsi que leurs composantes.           Ce travail représente une contribution quantitative dans l’étude de ce type d’acier industriel par l’usage de la caractérisation des diffractions neutrons et l’analyse ODF des neutrons.Mots clés : Diffraction Neutrons- aciers à faible pourcentage en carbone- texture- emboutissage

Evaluation of the Krio Language Version of the London Measure of Unplanned Pregnancy in Western Area, Sierra Leone

New ways of measuring pregnancy planning/intention such as the London  Measure of Unplanned Pregnancy (LMUP), which recognise the complexity of the construct, are being adopted worldwide. The aim of this study was to evaluate the psychometric properties of the Krio version of the LMUP in Sierra Leone. An interviewer-administered version of the LMUP was  translated into Krio and pre-tested with 12 pregnant women. Field testing involved 172 pregnant women aged 15–42, with 87 completing a re-test. Completion rates of LMUP items were 100%. LMUP scores 1-12 were captured. Reliability: the scale was internally consistent (Cronbach‘s alpha 0.84) and stable (weighted Kappa 0.93). Construct validity: all hypotheses were confirmed. Principal components analysis revealed five items (items 2-6) related to one construct. Mokken scaling procedure selected the same five items. Removal of item 1 (which had 97% endorsement of the ‗no contraception‘ response option) brought about only a very slight  improvement in LMUP performance, therefore we recommend retaining all six items. The Krio LMUP is reliable, valid and suitable to use in Sierra Leone.Keywords: Pregnancy, psychometric validation, Sierra Leone, unplanned pregnancy, KrioDe nouvelles façons de mesurer la planification / l'intention de la grossesse telles que la Mesure de Londres de la grossesse non planifiée (MLGNP), qui reconnaissent la complexité de la construction, sont adoptées dans le monde entier. Le but de cette étude était d'évaluer les propriétés psychométriques de la version Krio de la MLGNP en Sierra Leone. Une version de la MLGNP administrée par un intervieweur a été traduite en Krio et pré-testée auprès de 12 femmes enceintes. Les tests sur le terrain ont impliqué 172 femmes enceintes âgées de 15 à 42 ans, dont 87 ont effectué un nouveau test. Les taux d'achèvement des articles MLGNP étaient de 100%. Les scores MLGNP 1-12 ont été capturés. Fiabilité: l'échelle était cohérente en interne (alpha 0,84 de Cronbach) et stable (Kappa pondéré 0,93). Validité de construction: toutes les hypothèses ont été confirmées. L'analyse des composantes principales a révélé cinq éléments (éléments 2 à 6) liés à une construction. La procédure de mise à l'échelle Mokken a sélectionné les cinq mêmes éléments. La suppression du point 1 (qui avait approuvé à 97% l'option de réponse «sans contraception») n'a entraîné qu'une très légère amélioration des  performances de la MLGNP, nous recommandons donc de conserver les six points. La version Krio de la MLGNP est fiable, valide et adaptée à une utilisation en Sierra Leone.Mots-clés: Grossesse, validation psychométrique, Sierra Leone, grossesse non planifiée, Kri

Dietary flexibility of western red colobus in two protected areas with contrasting anthropogenic pressure

Food distribution and abundance can affect intra- and inter-dietary variation in non-human primates, influencing feeding ecology and altering behaviour. Natural and/or human-induced actions can influence the dynamics between primates and the environment, with associated impacts on socio-ecology and demography. This relationship in anthropogenic landscapes, however, is poorly understood. Here, we use DNA metabarcoding to obtain high resolution dietary diversity data, and multivariate generalised linear models to investigate variation in the diet of this threatened primate. We characterise the diet of the western red colobus (Piliocolobus badius) in both the better preserved Gola Rainforest National Park (GRNP, Sierra Leone), and in the fragmented forests of Cantanhez National Park (CNP, Guinea-Bissau), and evaluate biological, ecological and temporal differences. Dietary plant species richness was high in both protected areas, and the type of plants consumed varied significantly across seasons, space, and time. Although we identify dependence on a few key plants, red colobus in CNP consumed a higher average number of plant taxa than in GRNP, and 11% of the diet consisted of cultivated foods (e.g. mango). This is the first time a molecular approach has been used to investigate red colobus diet, and reveal dietary flexibility in degraded forests. Predicting the consequences of dietary change on long-term population persistence, however, remains a significant knowledge gap. Nevertheless, our results provide critical information to inform targeted regional conservation planning and implementation

Ebola virus epidemiology, transmission, and evolution during seven months in Sierra Leone

The 2013-2015 Ebola virus disease (EVD) epidemic is caused by the Makona variant of Ebola virus (EBOV). Early in the epidemic, genome sequencing provided insights into virus evolution and transmission and offered important information for outbreak response. Here, we analyze sequences from 232 patients sampled over 7 months in Sierra Leone, along with 86 previously released genomes from earlier in the epidemic. We confirm sustained human-to-human transmission within Sierra Leone and find no evidence for import or export of EBOV across national borders after its initial introduction. Using high-depth replicate sequencing, we observe both host-to-host transmission and recurrent emergence of intrahost genetic variants. We trace the increasing impact of purifying selection in suppressing the accumulation of nonsynonymous mutations over time. Finally, we note changes in the mucin-like domain of EBOV glycoprotein that merit further investigation. These findings clarify the movement of EBOV within the region and describe viral evolution during prolonged human-to-human transmission

Applicability of non-invasively collected matrices for human biomonitoring

With its inclusion under Action 3 in the Environment and Health Action Plan 2004–2010 of the European Commission, human biomonitoring is currently receiving an increasing amount of attention from the scientific community as a tool to better quantify human exposure to, and health effects of, environmental stressors. Despite the policy support, however, there are still several issues that restrict the routine application of human biomonitoring data in environmental health impact assessment. One of the main issues is the obvious need to routinely collect human samples for large-scale surveys. Particularly the collection of invasive samples from susceptible populations may suffer from ethical and practical limitations. Children, pregnant women, elderly, or chronically-ill people are among those that would benefit the most from non-invasive, repeated or routine sampling. Therefore, the use of non-invasively collected matrices for human biomonitoring should be promoted as an ethically appropriate, cost-efficient and toxicologically relevant alternative for many biomarkers that are currently determined in invasively collected matrices. This review illustrates that several non-invasively collected matrices are widely used that can be an valuable addition to, or alternative for, invasively collected matrices such as peripheral blood sampling. Moreover, a well-informed choice of matrix can provide an added value for human biomonitoring, as different non-invasively collected matrices can offer opportunities to study additional aspects of exposure to and effects from environmental contaminants, such as repeated sampling, historical overview of exposure, mother-child transfer of substances, or monitoring of substances with short biological half-lives

HIV-1 drug resistance mutations emerging on darunavir therapy in PI-naive and -experienced patients in the UK

\ua9 The Author 2016. Background: Darunavir is considered to have a high genetic barrier to resistance. Most darunavir-associated drug resistance mutations (DRMs) have been identified through correlation of baseline genotype with virological response in clinical trials. However, there is little information on DRMs that are directly selected by darunavir in clinical settings. Objectives: We examined darunavir DRMs emerging in clinical practice in the UK. Patients and methods: Baseline and post-exposure protease genotypes were compared for individuals in the UK Collaborative HIV Cohort Study who had received darunavir; analyses were stratified for PI history. A selection analysis was used to compare the evolution of subtype B proteases in darunavir recipients and matched PInaive controls. Results: Of 6918 people who had received darunavir, 386 had resistance tests pre- and post-exposure. Overall, 2.8% (11/386) of these participants developed emergent darunavir DRMs. The prevalence of baseline DRMs was 1.0% (2/198) among PI-naive participants and 13.8% (26/188) among PI-experienced participants. Emergent DRMs developed in 2.0% of the PI-naive group (4 mutations) and 3.7% of the PI-experienced group (12 mutations). Codon 77 was positively selected in the PI-naive darunavir cases, but not in the control group. Conclusions: Our findings suggest that although emergent darunavir resistance is rare, it may be more common among PI-experienced patients than those who are PI-naive. Further investigation is required to explore whether codon 77 is a novel site involved in darunavir susceptibility

South African Ebola diagnostic response in Sierra Leone : a modular high biosafety field laboratory

BACKGROUND : In August 2014, the National Institute for Communicable Diseases (NICD) in South Africa established a modular high-biosafety field Ebola diagnostic laboratory (SA FEDL) near Freetown, Sierra Leone in response to the rapidly increasing number of Ebola virus disease (EVD) cases. METHODS AND FINDINGS : The SA FEDL operated in the Western Area of Sierra Leone, which remained a ªhotspotº of the EVD epidemic for months. The FEDL was the only diagnostic capacity available to respond to the overwhelming demand for rapid EVD laboratory diagnosis for several weeks in the initial stages of the EVD crisis in the capital of Sierra Leone. Furthermore, the NICD set out to establish local capacity amongst Sierra Leonean nationals in all aspects of the FEDL functions from the outset. This led to the successful hand-over of the FEDL to the Sierra Leone Ministry of Health and Sanitation in March 2015. Between 25 August 2014 and 22 June 2016, the laboratory tested 11,250 specimens mostly from the Western Urban and Western Rural regions of Sierra Leone, of which 2,379 (21.14%) tested positive for Ebola virus RNA. CONCLUSIONS : he bio-safety standards and the portability of the SA FEDL, offered a cost-effective and practical alternative for the rapid deployment of a field-operated high biocontainment facility. The SA FEDL teams demonstrated that it is highly beneficial to train the national staff in the course of formidable disease outbreak and accomplished their full integration into all operational and diagnostic aspects of the laboratory. This initiative contributed to the international efforts in bringing the EVD outbreak under control in Sierra Leone, as well as capacitating local African scientists and technologists to respond to diagnostic needs that might be required in future outbreaks of highly contagious pathogens.S1 Video. ªHotº processing of Ebola clinical specimens, PPE and decontamination procedures in South African modular, field-operated biocontainment facility in Sierra Leone.Janusz T Paweska was supported by funding from National Research Foundation and the Global Disease Detection Programmehttp://www.plosntds.orgam2017Microbiology and Plant Patholog

Virological failure and development of new resistance mutations according to CD4 count at combination antiretroviral therapy initiation

Objectives: No randomized controlled trials have yet reported an individual patient benefit of initiating combination antiretroviral therapy (cART) at CD4 counts > 350 cells/μL. It is hypothesized that earlier initiation of cART in asymptomatic and otherwise healthy individuals may lead to poorer adherence and subsequently higher rates of resistance development. Methods: In a large cohort of HIV-positive individuals, we investigated the emergence of new resistance mutations upon virological treatment failure according to the CD4 count at the initiation of cART. Results: Of 7918 included individuals, 6514 (82.3%), 996 (12.6%) and 408 (5.2%) started cART with a CD4 count ≤ 350, 351-499 and ≥ 500 cells/μL, respectively. Virological rebound occurred while on cART in 488 (7.5%), 46 (4.6%) and 30 (7.4%) with a baseline CD4 count ≤ 350, 351-499 and ≥ 500 cells/μL, respectively. Only four (13.0%) individuals with a baseline CD4 count > 350 cells/μL in receipt of a resistance test at viral load rebound were found to have developed new resistance mutations. This compared to 107 (41.2%) of those with virological failure who had initiated cART with a CD4 count < 350 cells/μL. Conclusions: We found no evidence of increased rates of resistance development when cART was initiated at CD4 counts above 350 cells/μL. HIV Medicin

Safety and efficacy of single dose versus multiple doses of AmBisome for treatment of visceral leishmaniasis in eastern Africa: a randomised trial.

BACKGROUND: Anti-leishmanial drug regimens that include a single dose AmBisome could be suitable for eastern African patients with symptomatic visceral leishmaniasis (VL) but the appropriate single dose is unknown. METHODOLOGY: A multi-centre, open-label, non-inferiority, randomized controlled trial with an adaptive design, was conducted to compare the efficacy and safety of a single dose and multiple doses of AmBisome for the treatment of VL in eastern Africa. The primary efficacy endpoint was definitive cure (DC) at 6 months. Symptomatic patients with parasitologically-confirmed, non-severe VL, received a single dose of AmBisome 7.5 mg/kg body weight or multiple doses, 7 times 3 mg/kg on days 1-5, 14, and 21. If interim analyses, evaluated 30 days after the start of treatment following 40 or 80 patients, showed the single dose gave significantly poorer parasite clearance than multiple doses at the 5% significance level, the single dose was increased by 2·5 mg/kg. In a sub-set of patients, parasite clearance was measured by quantitative reverse transcriptase (qRT) PCR. PRINCIPAL FINDINGS: The trial was terminated after the third interim analysis because of low efficacy of both regimens. Based on the intention-to-treat population, DC was 85% (95%CI 73-93%), 40% (95%CI 19-64%), and 58% (95%CI 41-73%) in patients treated with multiple doses (n = 63), and single doses of 7·5 (n = 21) or 10 mg/kg (n = 40), respectively. qRT-PCR suggested superior parasite clearance with multiple doses as early as day 3. Safety data accorded with the drug label. CONCLUSIONS: The tested AmBisome regimens would not be suitable for VL treatment across eastern Africa. An optimal single dose regimen was not identified. TRIALS REGISTRATION: www.clinicaltrials.govNCT00832208

Most neutralizing human monoclonal antibodies target novel epitopes requiring both Lassa virus glycoprotein subunits

Lassa fever is a severe multisystem disease that often has haemorrhagic manifestations. The epitopes of the Lassa virus (LASV) surface glycoproteins recognized by naturally infected human hosts have not been identified or characterized. Here we have cloned 113 human monoclonal antibodies (mAbs) specific for LASV glycoproteins from memory B cells of Lassa fever survivors from West Africa. One-half bind the GP2 fusion subunit, one-fourth recognize the GP1 receptor-binding subunit and the remaining fourth are specific for the assembled glycoprotein complex, requiring both GP1 and GP2 subunits for recognition. Notably, of the 16 mAbs that neutralize LASV, 13 require the assembled glycoprotein complex for binding, while the remaining 3 require GP1 only. Compared with non-neutralizing mAbs, neutralizing mAbs have higher binding affinities and greater divergence from germline progenitors. Some mAbs potently neutralize all four LASV lineages. These insights from LASV human mAb characterization will guide strategies for immunotherapeutic development and vaccine design