Routing protocols performance and intelligent quality of service applied to MANETs.

The wireless revolution prompted by the success of IEEE 802.11 standard has pressed the research community to deal with requirements of new wireless networks. In particular, wireless ad-hoc networks which are, specifically, a collection of wireless mobile nodes dynamically forming a temporary network without the use of any preexisting infrastructure or centralised administration. Routing protocols used in ad-hoc networks must automatically and continually adjust to environments. Most emerging network services require specialised Quality-of-Service (QoS) functionalities that cannot be provided by the current QoS-unaware routing protocols.Despite the large amount of research in these areas, several issues still need further investigation. The following points have become main concerns: i) traditional use of the hop count metric does not capture the very nature of wireless paths, resulting in poor performance of wireless networks; ii) the lack of comprehensive simulation methods to effectively observed performance of networks in various conditions and iii) the complexity of multi-constraint routing decisions, resulting in poor service quality in the end-user's point of view.This study takes an experimental approach to the evaluation of ad-hoc routing protocols and focuses on routing parameters as well as multimedia application QoS performance. In this thesis, we tackle the above mentioned issues and implement an efficient solution for the multi-constraint problem based on network measurements of valid experiments set-up. This study is exclusively based on simulations using NS-2 network simulator. In order to obtain an overview of the limitations of current conventional routing protocols, AODV and DSR protocols are used and their limitations in terms of QoS are measured and discussed. Operating conditions vary greatly from a static, lightly loaded network to constantly moving nodes with up to 10 simultaneous transmission connections. The results show that network performance degrades quickly and that QoS requirement was hardly met by any of these protocols.To evaluate the overall network performance, a new fuzzy logic assessment approach was developed taking into account the QoS parameters requirement of the transmitted application. Critical parameters were obtained through detailed simulation experiments under demanding operating conditions. These parameters were used as input to the fuzzy logic system to allow the computation of a single metric to represent the input variables (i.e. delay, jitter and throughput). The end results show that without a complicated mathematical model, a QoS value can be computed. This study addresses both theoretical aspects of QoS performance and routing progress in ad-hoc networks as well as practical issues in the set-up of simulation based studies.Finally, this study indicated that intelligent techniques can be effective for processing multiple QoS metrics to obtain an overall parameter that represents the application QoS. They can be adapted, not only to QoS routing, but to various aspects of QoS provisioning techniques

Key sectors in the Moroccan economy: an application of input-output analysis

The exploration of the structural features and sectoral interdependences of and in an economy is fundamental for the understanding of its modes of functioning and of its transformations over time. Input-output analysis is largely used to fulfill this objective. Furthermore, information provided by the Leontief inverse matrix is useful for the identification of key sectors. This identification may guide policy makers in setting an adequate industrial strategy. In this paper, the classification of productive sectors is performed by using the Unweighted Rassmussen Approach. The ordering of sectors depends on the intensity of their links with other sectors. Two results ought to be highlighted. First, key sectors of the Moroccan economy (sectors that are classified in category II) reduced to two sectors in 2007 instead of four sectors in 1998. Second, the ordering of sectors is highly sensitive to the precision of the data and to the year in which the classification is realized

Implementation of an Affordable Method for MPS Diagnosis from Urine Screening to Enzymatic Confirmation: Results of a Pilot Study in Morocco

Background: Rapid and accurate diagnosis of mucopolysaccharidoses (MPS) is still a challenge due to poor access to screening and diagnostic methods and to their extensive clinical heterogeneity. The aim of this work is to perform laboratory biochemical testing for confirming the diagnosis of mucopolysaccharidosis (MPS) for the first time in Morocco. Methods: Over a period of twelve months, 88 patients suspected of having Mucopolysaccharidosis (MPS) were referred to our laboratory. Quantitative and qualitative urine glycosaminoglycan (GAG) analyses were performed, and enzyme activity was assayed on dried blood spots (DBS) using fluorogenic substrates. Enzyme activity was measured as normal, low, or undetectable. Results: Of the 88 patients studied, 26 were confirmed to have MPS; 19 MPS I (Hurler syndrome; OMIM #607014/Hurler-Scheie syndrome; OMIM #607015), 2 MPS II (Hunter syndrome; OMIM #309900), 2 MPS IIIA (Sanfilippo syndrome; OMIM #252900), 1 MPS IIIB (Sanfilippo syndrome; OMIM #252920) and 2 MPS VI (Maroteaux-Lamy syndrome; OMIM #253200). Parental consanguinity was present in 80.76% of cases. Qualitative urinary glycosaminoglycan (uGAGs) assays showed abnormal profiles in 31 cases, and further quantitative urinary GAG evaluation and Thin Layer Chromatography (TLC) provided important additional information about the likely MPS diagnosis. The final diagnosis was confirmed by specific enzyme activity analysis in the DBS samples. Conclusions: The present study shows that the adoption of combined urinary substrate analysis and enzyme assays using dried blood spots can facilitate such diagnosis, offer an important tool for an appropriate supporting care, and a specific therapy, when available

Utilization of prickly pear waste for baker's yeast production

The feasibility of baker's yeast production using fruits and peels of Opuntia ficus indica (OFI) as carbohydrate feedstock was investigated. Two response surface methodologies involving central composite face centered design (CCFD) were successfully applied. The effects of four independent variables on baker's yeast production from OFI fruit juice was evaluated using the first CCFD. The best results were obtained with 24 H of inoculum age, 30 degrees C temperature, 200 rpm of agitation, and 10% inoculum size. At the maximum point, the biomass concentration reached 9.29 g/L. A second CCFD was performed to optimize the sugar extraction from OFI fruit peels. The potential of these latter as a fermentation substrate was determined. From the experimental results, the OFI fruit peel is an appropriate carbon source for the production of baker's yeast. The maximum biomass concentration was 12.51 g/L. Different nitrogen supplements were added to promote the yields of baker's yeast. Corn steep liquor was found to be the best alternative nutrient source of casein hydrolysate and yeast extract for baker's yeast production.info:eu-repo/semantics/publishedVersio

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

Prescription des statines par les médecins généralistes français (impact de la recommandation de pratique clinique 2005)

PARIS6-Bibl. St Antoine CHU (751122104) / SudocSudocFranceF

The effects of the COVID-19 pandemic on economic growth in West Africa: the case of ECOWAS: Les effets de la pandémie COVID-19 sur les puissances économiques en Afrique de l’Ouest : cas de la CEDEAO

Résumé Parallèlement aux préoccupations relatives aux coûts sanitaires, l'impact que COVID-19 pourrait avoir sur les aspects socio-économiques est une préoccupation mondiale. Les pays de l’Afrique de l’Ouest, comme le reste des pays d'Afrique subsaharienne peuvent être particulièrement vulnérables aux chocs externes associés à la pandémie. L’objectif principal de cet article est de mettre en lumière les répercussions économiques de la pandémie COVID19 sur les économies de la zone CEDEAO et ce à travers une analyse descriptive des indicateurs Macroéconomiques des cinq puissances économiques membres de l’espace CEDEAO. Nous avons choisi le Nigéria, le Ghana, la Côte d’Ivoire, le Sénégal et le Burkina Faso. Ces cinq pays assurent 89,54 % du Produit Intérieur Brute de la communauté économique Ouest Africaine. Les résultats de la présente étude montrent que la covid-19 a influencé négativement sur la croissance économique de l’espace CEDEAO. Au cours de cet article, nous avons présenté, dans un premier temps, un cadre général sur la propagation de la Covid-19 et son impact sur l’économie mondiale, ce qui nous a permis, dans un deuxième temps, de ressentir l’ampleur de l’impact de la pandémie sur les cinq puissances économiques, locomotives de développement dans la zone CEDEAO. Mots clés : COVID-19, CEDEAO, Nigéria, Ghana, Côte d’Ivoire, Sénégal, Burkina Faso   Abstract In addition to concerns about health costs, the impact that COVID-19 may have on socioeconomic aspects is a global concern. West African countries, like the rest of subSaharan Africa, may be particularly vulnerable to external shocks associated with the pandemic. The main objective of this paper is to highlight the economic impact of the COVID19 pandemic on the economies of the ECOWAS zone through a descriptive analysis of the macroeconomic indicators of five member economies of the ECOWAS zone. We chose Nigeria, Ghana, Côte d'Ivoire, Senegal and Burkina Faso. These five countries account for 89.54% of the Gross Domestic Product of the West African Economic Community. The results of this study show that the pandemic has had a negative impact on economic growth in the ECOWAS region. In the course of this article, we first presented a general framework on the spread of Covid-19 and its impact on the world economy, which allowed us, in a second step, to feel the magnitude of the impact of the pandemic on the five economic powers, locomotives of development in the ECOWAS zone. Keywords: COVID-19, ECOWAS, Nigeria, Ghana, Ivory Coast, Senegal, Burkina Fas

Assessment of the impact of export diversification on economic growth in Morocco: Econometric application: Evaluation d’impact de la diversification des exportations sur la croissance économique au Maroc : Application économétrique

Résumé Dans un contexte mondiale caractérisé par l’instabilité et la fluctuation des recettes d’exportations, les taux de croissance économique enregistrés récemment par le Royaume du Maroc mettent en question les dynamiques structurelles de l’économie marocaine. Une structure productive caractérisée essentiellement par une insuffisante diversification et un faible indice de sophistication des exportations. L’objectif principal de cet article est d’évaluer empiriquement l’impact de la diversification des exportations sur la croissance économique au Maroc à partir d’un modèle autorégressive vectoriel (VAR). Les résultats de la présente étude montrent qu’une augmentation de 1% de la diversification des exportations marocaines influence positivement la croissance économique au Maroc de 0,27%. Au cours de cet article, nous avons présenté, dans un premier temps, les outils de mesure de la diversification des exportations ainsi que notre approche méthodologique, ce qui nous a permis, dans un deuxième temps, d’analyser les résultats de notre étude économétrique. Mots clés : Economie, Structure, diversification, productivité, exportations, croissance   Abstract In a global context marked by instability and fluctuating export revenues, the economic growth rates recorded recently by the Kingdom of Morocco call into question the structural dynamics of the Moroccan economy. The Moroccan productive structure is characterized mainly by insufficient diversification and a low index of export sophistication. The main objective of this paper is to empirically estimate the impact of export diversification on economic growth in Morocco using a vector auto regression model (VAR). The results of this study show that an increase in the diversification of Moroccan exports by 1% has a positive effect on economic growth in Morocco by 0.27%. In this paper, we first present the tools for measuring export diversification and our methodological approach, which allows us to analyze the results of our econometric study. Keywords: Economy, structure, diversification, productivity, exports, growth

Antioxidant Activity of Myrtus communis L. and Myrtus nivellei Batt. & Trab. Extracts: A Brief Review

Myrtus communis L. (myrtle) and Myrtus nivellei Batt. & Trab. (Saharan myrtle) have been used in folk medicine for alleviating some ailments. M. communis is largely distributed in the Mediterranean Basin, whereas M. nivellei is confined in specific zones of the central Saharan mountains. The chemical composition and antioxidant activity of berry and leaf extracts isolated from myrtle are deeply documented, whereas those isolated from Saharan myrtle extracts are less studied. In both species, the major groups of constituents include gallic acid derivatives, flavonols, flavonol derivatives, and hydroxybenzoic acids. In coloured berries, anthocyanins are also present. In M. nivellei extracts are reported for some compounds not described in M. communis so far: 2-hydroxy-1,8-cineole-β-d-glucopyranoside, 2-hydroxy-1,8-cineole 2-O-α-l-arabinofuranosyl (1→6)-β-d-glucopyranoside, rugosin A, and rugosin B. Berries and leaves extracts of both species had antioxidant activity. Comparative studies of the antioxidant activity between leaf and berry myrtle extracts revealed that leaf extracts are best antioxidants, which can be assigned to the galloyl derivatives, flavonols, and flavonols derivatives, although the ratio of these groups of compounds might also have an important role in the antioxidant activity. The anthocyanins present in myrtle berries seem to possess weak antioxidant activity. The antioxidant activity of sample extracts depended on various factors: harvesting time, storage, extraction solvent, extraction type, and plant part used, among other factors. Leaf extracts of myrtle revealed to possess anti-inflammatory activity in several models used. This property has been attributed either to the flavonoids and/or hydrolysable tannins, nevertheless nonprenylated acylphloroglucinols (e.g., myrtucommulone and semimyrtucommulone) have also revealed a remarkable role in that activity. The biological activities of myrtle extracts found so far may direct its use towards for stabilizing complex lipid systems, as prebiotic in food formulations, and as novel therapeutic for the management of inflammation