Porting TELEMAC-MASCARET to OPENPOWER and experimenting GPU offloading to accelerate the TOMAWAC module

Hydrodynamic

Hepatitis B screening practices and viral control among persons living with HIV in urban Senegal.

Chronic hepatitis B virus (HBV) infection affects >10% of the general population and is the leading cause of liver cirrhosis and cancer in West Africa. Despite current recommendations, HBV is often not tested for in clinical routine in the region. We included all people living with HIV (PLWH) in care between March and July 2019 at Fann University Hospital in Dakar (Senegal) and proposed hepatitis B surface antigen (HBsAg) test to those never tested. All HBsAg-positive underwent HIV and HBV viral load (VL) and liver stiffness measurement. We evaluated, using logistic regression, potential associations between patient characteristics and (a) HBV testing uptake; (b) HIV/HBV co-infection among individual HBsAg tested. We determined the proportion of co-infected who had HBV DNA >20 IU/ml on ART and sequenced HBV polymerase in those with HBV replication.of 1076 PLWH in care, 689 (64.0%) had never had an HBsAg test prior to our HBV testing intervention. Women and individuals >40 years old were less likely to have been previously tested. After HBV testing intervention,107/884 (12.1%) PLWH were HBsAg-positive. Seven of 58 (12.1%) individuals newly diagnosed with HIV/HBV co-infection had a detectable HBV VL, of whom five were HIV-suppressed. Two patients on ART including 3TC and AZT as backbone showed the presence of the triple resistance mutation 180M/204I/80V. In this Senegalese urban HIV clinic, the majority of patients on ART had never been tested for HBV infection. One in ten co-infected individuals had a detectable HBV VL despite HIV suppression, and 8% were not receiving a TDF-containing regimen

Willow short-rotation production systems in Canada and Northern United States: A review

Willow short rotation coppice (SRC) systems are becoming an attractive practice because they are a sustainable system fulfilling multiple ecological objectives with significant environmental benefits. A sustainable supply of bioenergy feedstock can be produced by willow on marginal land using well-adapted or tolerant cultivars. Across Canada and northern U.S.A., there are millions of hectares of available degraded land that have the potential for willow SRC biomass production, with a C sequestration potential capable of offsetting appreciable amount of anthropogenic green-house gas emissions. A fundamental question concerning 1 sustainable SRC willow yields was whether long-term soil productivity is maintained within a multi-rotation SRC system, given the rapid growth rate and associated nutrient exports offsite when harvesting the willow biomass after repeated short rotations. Based on early results from the first willow SRC rotation, it was found willow systems are relatively low nutrient-demanding, with minimal nutrient output other than in harvested biomass. The overall aim of this manuscript is to summarize the literature and present findings and data from ongoing research trials across Canada and northern U.S.A. examining willow SRC system establishment and viability. The research areas of interest presented here are the crop production of willow SRC systems, above- and below-ground biomass dynamics and the C budget, comprehensive soil-willow system nutrient budget, and soil nutrient amendments (via fertilization) in willow SRC systems. Areas of existing research gaps were also identified for the Canadian context

Collective radical oligomerisation induced by an STM tip on a silicon surface

International audience<p&gtOver the two past decades, on-surface covalent synthesis of organic nanostructures, has been widely investigated in the aim of fabrication of molecular electronic components and functional nanomaterials, owning to the Scanning Tunneling Microscopy monitoring which enhanced the synthesis comprehension at the atomic-scale size precision. 1 Here, we introduce a new strategy to obtain alkyl oligomers in a controlled manner using on-surface radical oligomerisations that are triggered by electrons between the tip of a scanning tunnelling microscope and the Si(111)-B surface (Figure). 2 This electron transfer event only occurs when the bias voltage is below-4.5 V and allows access to reactive radical species under exceptionally mild conditions. This transfer can effectively 'switch on' a sequence leading to the formation of oligomers of defined size distribution due to onsurface confinement of the reactive species. Our approach enables new way to initiate and control radical oligomerisations with tunnelling electrons, leading to molecularly precise nanofabrication. Figure: a) Representative schemes of the new strategy showing the subsequent steps of stm tip induced olygomerisations on Si(111)-B surface. b) STM image (25x25 nm2, Vs =-1.3 V, It = 7 pA, T = 110 K) representing an nano-pore inside the supramolecular network. c) The same nano-pore fully filled with rod-like structure released by STM tip during scanning.</p&g

STM-tip induced C-C and C-O cleavage towards the formation of alkane oligomers

International audienceOver the past decade, on-surface fabrication of organic nanostructures has been widely investigated for the development of molecular electronic devices, nanomachines, and new Materials[1]. Here, we introduce a new strategy to obtain alkyl oligomers in a controlled manner using on-surface radical tandem reactions that are triggered by the electrons between the sample surface and the tip of a scanning tunnelling microscope[2]. The resulting radical mediated mechanism is substantiated by a detailed theoretical study. This single-electron transfer event allows access to reactive radical species under exceptionally mild conditions and can effectively ‘switch on’ a tandem sequence leading to formation of oligomers of defined size distribution due to the on-surface confinement of reactive species. Our approach enables new ways to initiate and control radical oligomerisations with tunnelling electrons, leading to molecularly precise nanofabrication

Origin, acquisition and diversification of heritable bacterial endosymbionts in louse flies and bat flies

International audienceThe γ-proteobacterium Arsenophonus and its close relatives (Arsenophonus and like organisms, ALOs) are emerging as a novel clade of endosymbionts, which are exceptionally widespread in insects. The biology of ALOs is, however, in most cases entirely unknown, and it is unclear how these endosymbionts spread across insect populations. Here, we investigate this aspect through the examination of the presence, the diversity and the evolutionary history of ALOs in 25 related species of blood-feeding flies: tsetse flies (Glossinidae), louse flies (Hippoboscidae) and bat flies (Nycteribiidae and Streblidae). While these endosymbionts were not found in tsetse flies, we identify louse flies and bat flies as harbouring the highest diversity of ALO strains reported to date, including a novel ALO clade, as well as Arsenophonus and the recently described Candidatus Aschnera chinzeii. We further show that the origin of ALO endosymbioses extends deep into the evolutionary past of louse flies and bat flies, and that it probably played a major role in the ecological specialization of their hosts. The evolutionary history of ALOs is notably complex and was shaped by both vertical transmission and horizontal transfers with frequent host turnover and apparent symbiont replacement in host lineages. In particular, ALOs have evolved repeatedly and independently close relationships with diverse groups of louse flies and bat flies, as well as phylogenetically more distant insect families, suggesting that ALO endosymbioses are exceptionally dynamic systems

Prevention and Care of Hepatitis B in Senegal; Awareness and Attitudes of Medical Practitioners.

In highly endemic settings for hepatitis B virus (HBV) infection such as Senegal, access to HBV prevention and care is rapidly evolving. In this context, all medical practitioners should have baseline knowledge on HBV infection and promote access to vaccination, screening, and care. A knowledge and attitudes survey on HBV infection was conducted among a randomly selected sample of medical practitioners in Senegal. Participants were asked to fill-out a questionnaire on the HBV epidemiology, prevention, and treatment. A 60-item knowledge score was computed; the lower quartile of the observed score was used to define poor knowledge. Factors associated with poor knowledge were assessed using a logistic regression model. A total of 127 medical practitioners completed the questionnaire. Only 14 (11.0%) participants knew that HBV vaccine could be safely administered to pregnant women and 65 (51.2%) to newborns. Older practitioners (> 40 years) as well as general practitioners (compared with specialists) were more likely to have a poor knowledge score with odds ratios (ORs) of 3.1 (95% confidence interval [CI] 1.0-9.2) and 2.6 (95% CI 1.0-7.3), respectively. Practitioners who declared not to recommend HBV screening frequently during their consultation were more likely to present a poor knowledge score [OR: 3.0; (95% CI 1.1-8.2)]. As universal HBV screening is being promoted in countries with endemic HBV infection, our finding that poor screening attitudes were associated with a poor knowledge is of concern. There is a need to raise awareness of medical practitioners in Senegal toward universal HBV screening and early vaccination of newborns