Contrôle et diagnostic décentralisés des systèmes à évènements discrets approche multi-décisionnelle

De nos jours, les systèmes technologiques sont devenus très complexes (matériel informatique, logiciel, système de télécommunication, usine manufacturière, etc.), et cette complexité croît continuellement de sorte que les anciennes techniques intuitives utilisées pour leur conception, leur étude et leur réalisation deviennent inadaptées. À cause de cette complexité croissante, la probabilité pour qu'une erreur (ou panne) inattendue survienne est de plus en plus grande. Plus encore, quelques erreurs peuvent provoquer des accidents très graves causant des pertes économiques ou humaines. C'est dans ce cadre que les méthodes formelles ont été développées pour l'analyse, la conception et la réalisation des systèmes logiciels et électroniques quelque [i.e. quelle que] soit leur complexité. Ainsi, l'étude des systèmes à événements discrets (SED) a été introduite avec l'objectif de développer des méthodes formelles pour répondre à des besoins pressants, tels que le contrôle, le diagnostic, le pronostic, le test et la vérification des comportements discrets des systèmes technologiques. Cette thèse considère et généralise les études du contrôle et du diagnostic décentralisés des SED. Le principe commun du contrôle et du diagnostic décentralisés des SED est la prise de décision décentralisée, qui est basée sur l'utilisation d'une architecture décentralisée. Cette dernière est constituée de plusieurs décideurs locaux qui observent partiellement un SED et prennent des décisions locales qui sont ensuite fusionnées par un module de fusion D. Ce dernier, en se basant sur une fonction de fusion, calcule à partir des décisions locales une décision globale. Le système englobant les décideurs locaux et le module de fusion s'appelle un décideur décentralisé. L'ensemble de tous les décideurs décentralisés ayant D comme module de fusion est appelé D-architecture. La principale contribution de cette thèse est de proposer une nouvelle approche de prise de décision décentralisée, appelée multi-décision et qualifiée de multi-décisionnelle. Le principe de la multi-décision est basé sur l'utilisation de plusieurs (disons p) décideurs décentralisés (DD[indice supérieur j)[indice inférieur j=1,...,p] qui fonctionnent simultanément et en parallèle. Chaque DD[indice supérieur J] a une architecture décentralisée parmi celles qu'on trouve dans la littérature. C'est-à-dire que chaque DD[indice supérieur J] est constitué d'un ensemble de décideurs locaux ([Dec[indice supérieur J][indice inférieur i])[indice inférieur i=1,...,n] dont les décisions locales sont fusionnées par un module de fusion D[indice supérieur j] afin d'obtenir une décision globale. Dans l'architecture multi-décisionnelle, les décisions globales des p (DD[indice supérieur j])[indice inférieur j=1,...,p] sont fusionnées par un module D afin d'obtenir une décision effective qui respecte une propriété désirée Pr. L'intérêt de la multi-décision est que l'architecture ((DD[indice supérieur j])[indice inférieur j=1,..., p], D) constituée des différents (DD[indice supérieur j])[indice inférieur j =1,...,p] et de D généralise chacune des architectures DD[indice supérieur j]. C'est-à-dire que l'ensemble des SED auxquels on peut appliquer ((DD[indice supérieur j])[indice inférieur j=1,...,p], D) englobe les différents SED auxquels on peut appliquer les différents DD[indice supérieur j] séparément. Nous avons étudié l'approche multi-décisionnelle sur deux exemples de prise de décision : le contrôle supervisé et le diagnostic. On obtient alors le contrôle et le diagnostic multi-décisionnels. Dans les deux cas, l'approche multi-décisionnelle nécessite une décomposition de langages infinis (c.-à-d., contenant un nombre infini de séquences), qui est connue comme étant un problème difficile. Pour résoudre ce problème, on a proposé, dans le cas particulier des langages réguliers, une méthode qui transforme la décomposition d'un langage infini X en une décomposition d'un ensemble fini d'états marqués. Pour arriver à cela, on a dû s'imposer une restriction en ne considérant que les décompositions de X qui respectent une condition spécifique. Cette condition présente l'avantage de rendre les conditions d'existence de solutions vérifiables. Nous avons ainsi développé des algorithmes pour vérifier les conditions d'existence de solutions pour le contrôle et le diagnostic multi-décisionnels. Ces algorithmes ont le même ordre de complexité que les algorithmes qui vérifient les conditions d'existence de solutions pour le contrôle et le diagnostic décentralisés. Il est important de noter que les conditions d'existence obtenues pour une architecture multi-décisionnelle ((DD[indice supérieur j])[indice inférieur j=1,..., p], D) sont moins contraignantes que celles obtenues pour chacune des architectures DD[indice supérieur j]

Health risk behaviours amongst school adolescents: protocol for a mixed methods study

Abstract Background Determining risky behaviours of adolescents provides valuable information for designing appropriate intervention programmes for advancing adolescent’s health. However, these behaviours are not fully addressed by researchers in a comprehensive approach. We report the protocol of a mixed methods study designed to investigate the health risk behaviours of Moroccan adolescents with the goal of identifying suitable strategies to address their health concerns. Methods We used a sequential two-phase explanatory mixed method study design. The approach begins with the collection of quantitative data, followed by the collection of qualitative data to explain and enrich the quantitative findings. In the first phase, the global school-based student health survey (GSHS) was administered to 800 students who were between 14 and 19 years of age. The second phase engaged adolescents, parents and teachers in focus groups and assessed education documents to explore the level of coverage of health education in the programme learnt in the middle school. To obtain opinions about strategies to reduce Moroccan adolescents’ health risk behaviours, a nominal group technique will be used. Discussion The findings of this mixed methods sequential explanatory study provide insights into the risk behaviours that need to be considered if intervention programmes and preventive strategies are to be designed to promote adolescent’s health in the Moroccan school

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

DECENTRALIZED SUPERVISORY CONTROL OF DISCRETE EVENT SYSTEMS: INVOLVING THE FUSION SYSTEM IN THE DECISION-MAKING

ABSTRACT In this paper, we propose a new architecture for decentralized control of discrete event systems, whose basic principle is as follows: for every event which is controllable by several supervisors, each of the latter takes an enabling/disabling decision only when it is sure that this is the right decision which can be applied to the plant. Otherwise, the supervisor transmits its local information to the fusion system which will thus be involved in the enabling/disabling decision-making. We compare our approach with the previous decentralized approaches

Piperazine-1,4-diium bis(3-carboxy-2,3-dihydroxypropanoate)

The asymmetric unit of the title salt, C4H12N22+·2C4H5O6−, comprises one half of the piperazine-1,4-diium dication lying on a twofold rotation axis and one 3-carboxy-2,3-dihydroxypropanoate anion. In the crystal, the ions are linked into a three-dimensional network by N—H...O, C—H...O and O—H...O hydrogen bonds

Investigation of antioxidant and antihemolytic properties of Thymus satureioides collected from Tafilalet Region, south-east of Morocco

Objective:: To examine the antioxidant and antihemolytic activities of the aqueous extract, total polyphenols and total flavonoids of Thymus satureioides (T. satureioides). Methods:: This plant was collected from Tafilalet Region of Morocco. The aqueous extract was obtained by cold maceration, and the components were obtained by Soxhlet extraction using solvents of varying polarity. The identification and quantification of phenol (caffeic and rosmarinic acids) and flavones (luteolin 7-glycoside and hesperetin) were carried out by high performance liquid chromatography analysis. Results:: Total polyphenol and flavonoids contents in the aqueous extract of T. satureioides were (456.73±6.94) mg caffeic acid equivalent/g of dry plant and (172.79±2.12) mg rutin equivalent/g of dry plant, respectively. Different extracts showed good antioxidant activity. IC50 for 1,1-diphenyl-2-picrylhydrazil radical scavenging activity was (0.480±0.010), (0.418±0.005), (43.891±2.467) and (0.510±0.010) mg/mL for the aqueous extract, total polyphenol, flavonoids and trolox, respectively. Also, the extracts showed ferric reducing antioxidant power and the values were (50.79±2.02), (117.51±6.46), (7.03±0.29) and (44.33±7.55) mmol trolox/g for the aqueous extract, total polyphenol, flavonoids and trolox, respectively. Serum levels of malondialdehyde was significantly decreased in comparison with the oxidized control (P<0.001). They showed good activity against 2,2,-azobis 2-amidinopropane dihydrochloride induced hemolysis in erythrocytes of rabbit blood. In addition, they ameliorate the half time of hemolysis. Conclusions:: Our results provide evidence that aqueous extract, total polyphenols and total flavonoids of T. satureioides exhibit marked antioxidant and antihemolytic activities, thus confirming and justifying the popular uses of this plant to relieve some pains

Stewart-Treves Syndrome Involving Chronic Lymphedema after Mastectomy of Breast Cancer

Steward-Treves syndrome is a cutaneous angiosarcoma that usually appears after long evolution of a lymphoedema after mastectomy for mammary neoplasia associated with an axillary dissection. This is a rare disease develop most of the time in upper arm and often confounded with cutaneous metastasis. Only the biopsy and immunohistochemical study confirm the diagnosis. The treatment is surgical and consists of large cutaneous excision, an amputation of the limb or even its disarticulation and will be followed by chemotherapy. Despite the treatment, the prognosis remains severe with poor survival. We report the case of a patient who had a Steward-Treves syndrome 20 years after lymphoedema following a left mastectomy with axillary dissection

Anti-inflammatory, anticoagulant and antioxidant effects of aqueous extracts from Moroccan thyme varieties

Objective: To evaluate the anti-inflammatory, anticoagulant and antioxidant effects of aqueous extracts of thyme varieties from Moroccan. Methods: The aqueous extracts of tree medicinal plants [Thymus atlanticus (T. atlanticus), Thymus satureioides and Thymus zygis (T. zygis)] were screened for their antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl radical-scavenging, ferric reducing antioxidant power assay, radical scavenging activity method, the inhibition of 2,2'-azobis (2-amidinopropane) dihydrochloride that induces oxidative erythrocyte hemolysis and thiobarbituric acid reactive substances assay. The anti-inflammatory activity of aqueous extracts was evaluated in vivo using croton oil-induced ear edema and carrageenan-induced paw edema in mice and rats, respectively. This extracts were evaluated in vitro for their anticoagulant activity at the different concentrations by partial thromboplastin time and prothrombin time activated. Results: All thyme varieties were found to possess considerable antioxidant activity and potent anti-inflammatory activity in the croton oil-induced edema. Administration of aqueous extracts of two varieties (50 mg/kg) (T. zygis and T. atlanticus) reduced significantly the carrageenan-induced paw edema similar to non-steroidal anti-inflammatory drug (indomethacin, 10 mg/kg). In partial thromboplastin time and prothrombin time tests, T. atlanticus and T. zygis extracts showed the strongest anticoagulant activity. In contrast, Thymus satureioides did not show the anticoagulant activity in these tests. Conclusions: All aqueous extracts possess considerable antioxidant activity and are rich in total polyphenol and flavonoid but they act differently in the process of inflammatory and coagulation studied. This study shows great variability of biological activities in thyme varieties