An Efficient Trim Structure for Rendering Large B-Rep Models

International audienceWe present a multiresolution trim structure for fast and accurate B-Rep model visualization. To get a good tradeoff between performance and visual accuracy, we propose to use a vectorial but approximated representation of the model that allows efficient, real-time GPU exploitation. Our structure, based on a quadtree, enables us to do shallow lookups for distant fragments. For closeups, we leverage hardware tessellation. We get interactive frame rates for models that consists of hundreds of thousands of B-Rep faces, regardless of the zoom level

Une structure de découpe efficace pour l'affichage de grands modèles B-Rep

National audienceNous présentons une structure de découpe multirésolution pour l'affichage rapide et précis de modèles B-Rep. Nous proposons d'utiliser une représentation de la découpe de face basée sur un quadtree, autorisant une gestion efficace par le GPU. Ce quadtree contient des références à des courbes de découpe qui sont utilisées dans un fragment shader pour effectuer la classification de point d'une manière implicite. La façon dont sont stockées les informations multirésolution dans le quadtree nous permet de réduire les accès à notre structure lorsque les fragments sont distants de la caméra. Pour les objets en avant plan, nous nous appuyons sur la tessellation matérielle pour améliorer les performances, en réduisant la quantité de calcul à effectuer pour chaque fragment. Nous obtenons un affichage intéractif pour de très gros modèles comprenant des centaines de milliers de faces B-Rep, quel que soit le niveau de zoom

Design and challenges of a large HIV prevention clinical study on mother-to-child transmission: ANRS 12397 PROMISE-EPI study in Zambia and Burkina Faso

Under embargo until: 2022-04-23Post-natal HIV infection through breastfeeding remains a challenge in many low and middle-income countries, particularly due to non-availability of alternative infant feeding options and the suboptimal Prevention of Mother to Child Transmission of HIV-1 (PMTCT) cascade implementation and monitoring. The PROMISE-EPI study aims to address the latter by identifying HIV infected mothers during an almost never-missed visit for their infant, the second extended program on immunization visit at 6–8 weeks of age (EPI-2). The study is divided into 3 components inclusive of an open-label randomized controlled trial aiming to assess the efficacy of a responsive preventive intervention compared to routine intervention based on the national PMTCT guidelines for HIV-1 uninfected exposed breastfeeding infants. The preventive intervention includes: a) Point of care testing for early infant HIV diagnosis and maternal viral load; b) infant, single-drug Pre-Exposure Prophylaxis (PrEP) (lamivudine) if mothers are virally unsuppressed. The primary outcome is HIV-transmission rate from EPI-2 to 12 months. The study targets to screen 37,000 mother/infant pairs in Zambia and Burkina Faso to identify 2000 mother/infant pairs for the clinical trial. The study design and challenges faced during study implementation are described, including the COVID-19 pandemic and the amended HIV guidelines in Zambia in 2020 (triple-drug PrEP in HIV exposed infants guided by quarterly maternal viral load). The changes in the Zambian guidelines raised several questions including the equipoise of PrEP options, the standard of care-triple-drug (control arm in Zambia) versus the study-single-drug (intervention arm).acceptedVersio

Renal Abnormalities among Sickle Cell Disease Patients in a Poor Management Setting: A Survey in the Democratic Republic of the Congo.

peer reviewed[en] Background and objective: Sickle cell disease (SCD) is now a well-established cause of renal damage. In the northeast of the Democratic Republic of Congo (DRC), SCD is common. However, sickle cell nephropathy remains unstudied in this region. Thus, this study aimed to assess renal abnormalities in SCD patients in Kisangani (northeastern DRC). Methods: This cross-sectional study included 98 sickle cell patients selected from six health facilities in Kisangani and 89 healthy non-sickle cell subjects as the control group. Based on a survey form, a clinical examination and biological tests were performed to collect data related to the sex, age, weight, height, pressure, serum creatinine, serum uric acid, urinary albumin/creatinine ratio, and hemoglobin phenotype. We used a spectrophotometer to measure serum creatinine and uricemia, the sickle SCAN® device for hemoglobin phenotype, and an automatic multifunction analyzer for urine albumin/creatinine ratio. Data were entered into an Excel file and analyzed on SPSS 20.0. Results: The mean urine albumin-to-creatinine ratio was 11.79±9.03 mg/mmol in SCD patients, significantly higher than in AA (1.69±1.89 mg/mmol) and AS (2.97±4.46 mg/mmol) subjects. The decrease in glomerular filtration rate was more observed in SCD patients with hyperuricemia compared to those with normal uric acid levels. A significantly elevated prevalence of chronic kidney disease was observed among SCD patients (87.8%) compared to 23.8% in AS and 7.7% in AA subjects. Conclusions: This study highlighted that albuminuria and chronic kidney disease are common in SCD patients in Kisangani. More studies are needed to further document these complications

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Découverte des bactéries phytopathogènes, il y a cent ans : controverses et polémiques transatlantiques

Découverte des bactéries phytopathogènes, il y a cent ans : controverses et polémiques transatlantiques. Journée commune Académie des sciences & Académie d'agriculture de Franc

Erwinia amylovora : general characteristics, biochemistry and serology

[i]Erwinia amylovora[/i] : general characteristics, biochemistry and serolog

Saint Pierre et Saint Paul dans l'église nestorienne

par M. l'Abbé MartinText teilw. in syr. Schr., syr

Les nouveautés issues de la loi Travail

International audienceDepuis 20 ans, rares sont les textes portant réforme du code du à avoir déclenché autant de crispations et de passions politiques, sociales et juridiques. La est finalement promulguée le 8 août 2016(1). Quels sont les impacts pour les associations