ОБЗОР И СОСТОЯНИЕ ГОРНОЙ ОТРАСЛИ АЛЮМИНИЯ В МИРЕ И В РЕСПУБЛИКЕ ГВИНЕЕ

Aluminum is one of the most common metals in the earth’s crust. The mass concentration of aluminum in the earth’s crust according to various researchers is from 7,45 to 8,14%. Today, aluminum ranks is second in the world in terms of consumption among all metals, second only to steel, and the demand for it is constantly increasing. The main raw materials for processing aluminum plants are bauxites and nephelines. According to preliminary data of the International Institute of Aluminum, the world production of primary aluminum increased by 0,5% in 2016 and reached 58,167 million tons. The growth of the world’s population, the economic recovery, and the active urbanization of developing countries provide a stable demand for aluminum. Aluminum is widely used in construction, automotive, packaging and other areas. The growth in aluminum consumption is closely related to the growth in aluminum production. China is the leader of this metal producer. The company by the aluminum producer is Hongqiao. The pricing of metals on the world market is the London Metal Exchange LME, and aluminum prices will rise. The localization of the bauxite deposit on land is unevenly distributed; huge resources are concentrated in the tropical and subtropical areas. Among lateritic deposits, objects of the bowal type are of greatest industrial importance, and are widely distributed in Guinea, India. Brazil. In perspective, the Republic of Guinea can become a leader in the production of the world market. Bauxite in the territory of Guinea was first discovered by the A.Lacroix islands of the Loos archipelago at the beginning of the 20th century. Guinea has a very high quality inventory of bauxite more than half of the world’s resources. Given the pace of exploitation of bauxite in other countries, and in the coming decades, Guinea will become the main center for the production of alumina and even aluminum.Алюминий один из самых распространенных металлов земной коры. Массовая концентрация алюминия в земной коре по данным различных исследователей составляет от 7,45 до 8,14%. На сегодняшний день алюминий занимает второе место в мире по объемам потребления среди всех металлов, уступая лишь стали, и спрос на него постоянно увеличивается. Главным сырьем для перерабатывающих алюминиевых заводов служат бокситы и нефелины. Согласно предварительным данным Международного института алюминия, мировое производство первичного алюминия по итогам 2016 года увеличилось на 0,5% и достигло 58,167 млн т. Рост населения планеты, экономический подъем, и активная урбанизация развивающихся стран обеспечивают стабильный спроса на алюминий.Алюминий широко используется в строительстве, автомобилестроении, производстве упаковки и других сферах. Рост потребления алюминия тесно связан с ростом производства алюминия. Китай является лидером производителя этот металла. Географически месторождения бокситов на земле распределены очень неравномерно, огромные ресурсы сосредоточены в тропических и субтропических областях. Среди латеритных месторождений наибольшее промышленное значение имеют объекты бовального типа, широко распространенные в Гвинее, в Индии и Бразилии. В перспективе Республика Гвинея может стать лидером по добыче бокситов на мировом рынке. Бокситы на территории Гвинеи впервые были обнаружены А.Лакроикс (A.Lacroix) на островах архипелага Лоос (Loos) в начале XX века. Гвинея обладает очень качественным инвентаризационным запасом бокситов более чем половины мировых ресурсов. С учетом темпов эксплуатации бокситов в других странах, в ближайшие десятилетия Гвинея станет основным центром производства глинозема и даже алюминия

Rapid Molecular Assays for Specific Detection and Quantitation of Loa loa Microfilaremia

Loa loa is a filarial nematode that infects over 10 million people in Africa. Most infections cause no symptoms, but individuals with large numbers of blood-stage microfilariae are at risk for fatal reactions to ivermectin, an antiparasitic agent used to treat and prevent infections with Onchocerca volvulus, a related filarial parasite that may occur alongside L. loa. To address the urgent need for a point-of-care L. loa diagnostic assay, we screened a Loa microfilaria gene expression library and identified 18 Loa-specific DNA targets. From two targets, we developed a novel, rapid quantitative PCR assay for estimating L. loa microfilaria burden. The assay is highly sensitive (detects a single microfilaria in 20 µL of blood) and correlates well with microfilaria counts obtained with conventional microscopic techniques. The assay is species-specific for L. loa compared with related filarial parasites (including O. volvulus) and can be used in its current form in resource-rich areas as a diagnostic tool for L. loa infection. Although modifications will be required to make point-of-care use feasible, our assay provides a proof of concept for a potentially valuable tool to identify individuals at risk for adverse reactions to ivermectin and to facilitate the implementation of filarial control programs

Etude de la cinétique de l’hémolyse dans les poches de concentrés érythrocytaires des donneurs de sanghétérozygotes AS et son implication transfusionnelle

Introduction: Le don de sang par le sujet drépanocytaire hétérozygote AS constitue un champ d’investigation peu exploré.Objectif: Contribuer à la définition des conditions du don de sang par les sujets AS.Methodologie: Il s’agissait d’une étude prospective horizontale qui s’est déroulée au Centre National de Transfusion Sanguine (CNTS) à Abidjan-Treichville sur une durée de 02 mois d’octobre 2010 à novembre 2010. Nous avons sélectionné 11 donneurs AS dans une population de donneurs de sang réguliers et 11 donneurs témoins AA. Tous répondaient aux critères d’ap tude au don. Une Numération Formule Sanguine (NFS) et un dosage de la kaliémie ont été réalisés à Jour 0 Jour 10 Jour 20 et Jour 30. Les dosages ont été faits de façon comparative.Resultats: Le taux d’hémoglobine moyen de nos donneurs avant le don était supérieur ou égal à 12g/dl. On observait une diminution du taux d’hémoglobine dans le temps à par r de Jour 10 chez les AS. Chez les AA, après une diminution brève à Jour 10, le taux restait stable dans le temps. Le poids moyen en hémoglobine des poches issues de donneurs AS était proche des normes de production des Concentrés de Globules Rouges à Jour 0 et Jour 10 mais le poids baissait à partir de Jour 20. Le poids en hémoglobine des poches AS était inférieur à celui des poches AA. La kaliémie augmentait dans le temps, ceci traduisait indirectement l’hémolyse. Cette augmentation de la kaliémie était paradoxalement plus importante chez les AA que les AS.Conclusion: Cette étude montre une cinétique de l’hémolyse plus importante dans les poches AS à partir de Jour 10.Mots Clés: Cinétique, Hémolyse, Trait drépanocytaireEnglish AbstractEnglish Title: Study of the kinetics of hemolysis in red cell concentrated blood units from heterogenous AS sickle cell blood donors and its transfusion implication.Introduction: Blood donation from heterogeneous AS sickle cell donors represents a little explored field of research.Objective: To contribute to define of blood donation conditions by AS subjects.Methodology: This was a prospective and cross-sectional study held at the National Blood Transfusion Center (CNTS) Abidjan-Treichville over a period of 02 months from October 2010 to November 2010. We selected 11 AS donors in a population of repeat blood donors and 11 AA donors who served as controls. All met the suitability criteria for donation. A full blood count (FBC) and a monitoring of serum potassium were done at Day 0, Day 10 Day 20 and Day 30. The results of assays were done compared.Results: The mean hemoglobin levels of our donors before donation was greater than or equal to 12g / dl. We observed a decrease in hemoglobin levels over the me from Day 10 in AS. In AA, after a brief decline at Day 10, the rate remained stable over the time. The average weight of hemoglobin AS donors in blood bags was close to those of standards of Red Cell Concentrates on Day 0 and Day 10 but the weight felt from Day 20. Weights of hemoglobin AS blood bags were lower than those of AA. Serum potassium levels increased over the time, it indirectly reflected hemolysis. The increase in serum potassium was paradoxically higher in the AA than in AS blood units.Conclusion: This study shows that hemolysis kinetic is more important in AS blood units from Day 10

Rice yields enhanced through integrated management of cover crops and phosphate rock in phosphorus-deficient ultisols in West Africa

The relatively low solubility and availability of phosphorus (P) from indigenous phosphate rock could be enhanced by legumes in the acid soils of humid forest agroecosystems. Crotalaria micans L. was grown in a screenhouse without P or with P from triple superphosphate (TSP) and Malian Tilemsi Rock P. The P response of 20 cover crops was field-evaluated using TSP and Rock P. In both experiments, the fertilized cover crops were followed by upland rice without mineral N or P application. Mean rice grain yield and agronomic residual P-use efficiency were similar for both P sources. In the field, 1-year fallow treatment of Canavalia ensiformis (velvet bean) supplied with Mali Rock P gave the highest rice grain yield of 3.1 Mg ha-1, more than 180% that of 2-year continuous unfertilized rice (cv. 'WAB 56-50'). Among continuous rice plots, 'NERICA 2' (interspecific rice) supplied with Rock P produced the highest yield (2.0 Mg ha-1), suggesting that 'NERICA 2' might have greater potential to solubilize rock P. Results indicate that when combined with an appropriate legume, indigenous rock-P can release sufficient P to meet the P requirement of the legume and a following upland rice crop in rotation

Simulating the impact of varying vegetation on West African monsoon surface fluxes using a regional convection‐permitting model

This study assessed the sensitivity of the West African climate to varying vegetation fractions. The assessment of a such relationship is critical in understanding the interactions between land surface and atmosphere. Two sets of convection-permitting simulations from the UK Met Office Unified Model at 12 km horizontal resolution covering the monsoon period May–September (MJJAS) were used, one with fixed vegetation fraction (MF-V) and the other with time-varying vegetation fraction (MV-V). Vegetation fractions are based on MODIS retrievals between May and September. We focused on three climatic zones over West Africa: Guinea Coast, Sudanian Sahel, and the Sahel while investigating heat fluxes, temperature, and evapotranspiration. Results reveal that latent heat fluxes are the most strongly affected by vegetation fraction over the Sahelian and Sudanian regions while sensible heat fluxes are more impacted over the Guinea Coast and Sudanian Sahel. Also, in MV-V simulation there is an increase in evapotranspiration mainly over the Sahel and some specific areas in Guinea Coast from June to September. Moreover, it is noticed that high near-surface temperature is associated with a weak vegetation fraction, especially during May and June. Finally, varying vegetation seems to improve the simulation of surface energy fluxes and in turn impact on climate parameters. This suggests that climate modelers should prioritize the use of varying vegetation options to improve the representation of the West African climate system

The Schistosomiasis Control Initiative (SCI): rationale, development and implementation from 2002-2008

Schistosomiasis remains one of the most prevalent parasitic diseases in developing countries. After malaria, schistosomiasis is the most important tropical disease in terms of human morbidity with significant economic and public health consequences. Although schistosomiasis has recently attracted increased focus and funding for control, it has been estimated that less than 20% of the funding needed to control the disease in Africa is currently available. In this article the following issues are discussed: the rationale, development and objectives of the Schistosomiasis Control Initiative (SCI)-supported programmes; the management approaches followed to achieve implementation by each country; mapping, monitoring and evaluation activities with quantifiable impact of control programmes; monitoring for any potential drug resistance; and finally exit strategies within each country. The results have demonstrated that morbidity due to schistosomiasis has been reduced by the control programmes. While challenges remain, the case for the control of schistosomiasis has been strengthened by research by SCI teams and the principle that a national programme using ‘preventive chemotherapy' can be successfully implemented in sub-Saharan Africa, whenever the resources are available. SCI and partners are now actively striving to raise further funds to expand the coverage of integrated control of neglected tropical diseases (NTDs) in sub-Saharan Afric

Improvement of Rice Production under Drought Conditions in West Africa: Application of QTLs in Breeding for Drought Resistance

Rice plays a paramount role in food and nutrition security in many West African countries. Despite the doubling of production during the last decade, rice consumption has grown faster, creating a deficit between the demand and supply. Although the West African sub-region remains the main rice-producing centre on the continent, production is severely hampered by biotic and abiotic stresses. Drought is one of the factors that most severely reduce grain yields of rice. Systems of production need to be established in order to mitigate yield loss as a result of drought. This review discusses the effects of drought on rice production in West Africa and its mitigation with an emphasis on the improvement of tolerance to drought stress. Yield stability can be achieved by developing drought-tolerant varieties through several processes encompassing profiling of known QTLs and identification of new ones, marker-assisted selection, genomic selection, and extensive multi-locational yield trials. We suggest a comprehensive strategy for breeding drought-tolerant rice varieties in West Africa

Metabolic Traits and Stroke Risk in Individuals of African Ancestry: Mendelian Randomization Analysis.

BACKGROUND AND PURPOSE: Metabolic traits affect ischemic stroke (IS) risk, but the degree to which this varies across different ethnic ancestries is not known. Our aim was to apply Mendelian randomization to investigate the causal effects of type 2 diabetes (T2D) liability and lipid traits on IS risk in African ancestry individuals, and to compare them to estimates obtained in European ancestry individuals. METHODS: For African ancestry individuals, genetic proxies for T2D liability and circulating lipids were obtained from a meta-analysis of the African Partnership for Chronic Disease Research study, the UK Biobank, and the Million Veteran Program (total N=77 061). Genetic association estimates for IS risk were obtained from the Consortium of Minority Population Genome-Wide Association Studies of Stroke (3734 cases and 18 317 controls). For European ancestry individuals, genetic proxies for the same metabolic traits were obtained from Million Veteran Program (lipids N=297 626, T2D N=148 726 cases, and 965 732 controls), and genetic association estimates for IS risk were obtained from the MEGASTROKE study (34 217 cases and 406 111 controls). Random-effects inverse-variance weighted Mendelian randomization was used as the main method, complemented with sensitivity analyses more robust to pleiotropy. RESULTS: Higher genetically proxied T2D liability, LDL-C (low-density lipoprotein cholesterol), total cholesterol and lower genetically proxied HDL-C (high-density lipoprotein cholesterol) were associated with increased risk of IS in African ancestry individuals (odds ratio per doubling the odds of T2D liability [95% CI], 1.09 [1.07-1.11]; per standard-deviation increase in LDL-C, 1.12 [1.04-1.21]; total cholesterol: 1.23 [1.06-1.43]; HDL-C, 0.93 [0.89-0.99]). There was no evidence for differences in these estimates when performing analyses in European ancestry individuals. CONCLUSIONS: Our analyses support a causal effect of T2D liability and lipid traits on IS risk in African ancestry individuals, with Mendelian randomization estimates similar to those obtained in European ancestry individuals