Elaboration of belite cement with low environment impact

The objective of this work is to valorise the discharges (rejections) of the Boukhedra iron ore mine (east of Algeria) as raw materials for the elaboration of the cement raw. The study concerns the development of different types of low impact environmental belite cements whose raw are exclusively mine rejections. The use of a low CaO / SiO2 ratio and the combination of quick cooling of clinker with adequate NaF and LiF mineralization in association with CaSO4, has led to the production of belite cement with high hydraulic reactivity comparable to that of ordinary Portland cements. The used mineralization plays also a positive role in improving performance in terms of firing of the raw, by lowering the clinker process temperatures of these cements, thus, enabling an additional gain in terms of environmental impact and energy consumption. This mineralization and the low LSF of these cements allows obtaining them at low burning temperatures 1150 °C and 1100 °C for the cement with 2%LiF. This is 350 °C lower to ordinary Portland cement. The addition of CaSO4, NaF and LiF to the clinkers makes the improvement of its clinkering possible. The effect of LiF seems to be the most significant followed by NaF and finally, CaSO

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

Étude numérique par la méthode de Boltzmann sur réseau (MRT-LBM) des transferts thermiques couplés

International audienceA two dimensional numerical analysis of natural and double diffusive convection in the presence of volumetricradiation within a differentially heated square cavity containing a semitransparent gray and scattering gas wasconducted. The simulation of flow and heat transfer is achieved by adopting a hybrid scheme with the latticeBoltzmann method (LBM-MRT) to compute velocities and the finite difference method (FDM) for temperatureand concentration calculation, this scheme is coupled with the discrete ordinate method (DOM) to perform theinformation necessary for the radiative energy equation (RTE). Various parameters such as the Rayleigh numberRa, the emissivity of the walls εi, Planck number Pl and the Albedo ω have been studied numerically to assesstheir impact on the flow structure and temperature distribution.Une modélisation bi-dimensionnelle est effectuée pour la convection naturelle en présence de rayonnementvolumique dans une cavité carrée dont les deux parois verticales sont différentiellement chauffées contenant unmilieu gris semi transparent et diffusant. La simulation de l'écoulement et du transfert de chaleur est réalisée enadoptant un schéma hybride entre la méthode de Boltzmann sur réseau (LBM-MRT) pour la détermination desvitesses et la méthode aux différences finies (FDM) pour les températures. Ce schéma est couplé avec laméthode des ordonnées discrètes (DOM) pour le calcul de l’information radiative nécessaire à l’équationd’énergie. L’influence de plusieurs paramètres tels que le nombre de Rayleigh Ra, l'émissivité des parois εi, lenombre Planck Pl et l'albédo de diffusion ω, a été étudiée numériquement

One‐stage combined approach en bloc vertebrectomy for primary Ewing's sarcoma of mobile spine in an adult patient: 3 years following aggressive surgery for a rare entity

Key Clinical Message Currently, there is no consensus on the optimal management of nonmetastatic Ewing's sarcoma of the mobile spine. However, associated to chemotherapy, aggressive surgery with en bloc wide resection seems to improve local control and survival. Abstract Primary Ewing's sarcoma (EWS) of non‐sacral spine is extremely rare, especially in middle‐age. Therapeutic strategy aims: to large tumor resection, to provide spine stability and to avoid recurrence through chemo and radiotherapy. We report a case of thoracic spine EWS in an adult treated by combined approach en bloc vertebrectomy

Mutation Screening of the BRCA1 Gene in Early Onset and Familial Breast/Ovarian Cancer in Moroccan Population

Worldwide variation in the distribution of BRCA mutations is well recognised, and for the Moroccan population no comprehensive studies about BRCA mutation spectra or frequencies have been published. We therefore performed mutation analysis of the BRCA1 gene in 121 Moroccan women diagnosed with breast cancer. All cases completed epidemiology and family history questionnaires and provided a DNA sample for BRCA testing. Mutation analysis was performed by direct DNA sequencing of all coding exons and flanking intron sequences of the BRCA1 gene. 31.6 % (6/19) of familial cases and 1 % (1/102) of early-onset sporadic (&#60; 45 years) were found to be associated with BRCA1 mutations. The pathogenic mutations included two frame-shift mutations (c.798_799delTT, c.1016dupA), one missense mutation (c.5095C&#62;T), and one nonsense mutation (c.4942A&#62;T). The c.798_799delTT mutation was also observed in Algerian and Tunisian BC families, suggesting the first non-Jewish founder mutation to be described in Northern Africa. In addition, ten different unclassified variants were detected in BRCA1, none of which were predicted to affect splicing. Most unclassified variants were placed in Align-GVGD classes suggesting neutrality. c.5117G&#62;C involves a highly conserved amino acid suggestive of interfering with function (Align-GVGD class C55), but has been observed in conjunction with a deleterious mutation in a Tunisian family. These findings reflect the genetic heterogeneity of the Moroccan population and are relevant to genetic counselling and clinical management. The role of BRCA2 in BC is also under study.</p