74 research outputs found

    Automatic Generation of Correlation Rules to Detect Complex Attack Scenarios

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    International audienceIn large distributed information systems, alert correlation systems are necessary to handle the huge amount of elementary security alerts and to identify complex multi-step attacks within the flow of low level events and alerts. In this paper, we show that, once a human expert has provided an action tree derived from an attack tree, a fully automated transformation process can generate exhaustive correlation rules that would be tedious and error prone to enumerate by hand. The transformation relies on a detailed description of various aspects of the real execution environment (topology of the system, deployed services, etc.). Consequently, the generated correlation rules are tightly linked to the characteristics of the monitored information system. The proposed transformation process has been implemented in a prototype that generates correlation rules expressed in an attack description language

    : Anticiper les Ă©volutions pour les accompagner et les maĂźtriser

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    Cette recherche comprend quatre volets.Le premier prĂ©sente le fonctionnement d’outils numĂ©riques existants d’analyse mathĂ©matique du droit. L’intelligence artificielle permet de modĂ©liser certains aspects de l’activitĂ© juridique. En appliquant une mĂ©thodologie rigoureuse, on peut en particulier prĂ©senter l’éventail des dĂ©cisions qui seraient prises par une juridiction donnĂ©e sur un dossier caractĂ©risĂ© par quelques dizaines de critĂšres. Cette quantification fine de l’alĂ©a judiciaire, qui va bien au-delĂ  de simples statistiques, permet de comprendre et d’analyser les pratiques et, le cas Ă©chĂ©ant, de les faire Ă©voluer.Le deuxiĂšme volet est consacrĂ© Ă  l’encadrement juridique de ces Modes Algorithmiques d’Analyse des DĂ©cisions (MAAD).Leur domaine de compĂ©tence identifiĂ© - les contentieux juridiquement analogues – leur cadre juridique s’articule principalement autour de quatre points :- les rĂ©utilisations des donnĂ©es judiciaires- l’éthique avec un principe de transparence qui s’applique aux mĂ©thodes et aux rĂ©sultats- les responsabilitĂ©s que le fait gĂ©nĂ©rateur soit constituĂ© par une faute prĂ©sumĂ©e ou qu’il provienne de l’autonomie de l’algorithme- l’intĂ©gration des MAAD Ă  des procĂ©dures dĂ©matĂ©rialisĂ©es de rĂšglement judiciaire et extra-judiciaire des litigesDans le troisiĂšme volet, une enquĂȘte a Ă©tĂ© menĂ©e auprĂšs des prĂ©sidents des tribunaux de grande instance et des Cours d’appel de mĂ©tropole et d’outre-mer ainsi que de la Cour de cassation dans l’objectif de connaĂźtre leur perception de ces outils, leurs attentes et leurs suggestions quant Ă  leur emploi. Elle a permis de recueillir les avis de magistrats intĂ©ressĂ©s par ces outils. Les magistrats soulignent la nĂ©cessitĂ© de rĂ©guler leur conception et d’accompagner leurs usages.Le quatriĂšme volet, sociologique, montre que les dynamiques internes au champ juridique, qui se traduisent par l’« appropriation des nouveaux outils par les acteurs du droit », seront dĂ©terminantes dans le processus de changement qui devrait se traduire par une montĂ©e en puissance des algorithmes au sein de l’institution qu’est la Justice Si d’importantes forces de changement sont dĂ©jĂ  Ă  l’Ɠuvre, elles reposent sur la mobilisation d’acteurs aux caractĂ©ristiques spĂ©cifiques plutĂŽt « subalternes » dans lechamp juridique voire, s’agissant des dirigeants de start up , clairement pĂ©riphĂ©riques. Ces derniers apparaissent atypiques par l eur trajectoire, qu’elle soit professionnelle ou profane, et leur attitude rĂ©formatrice plus ou moins « radicale » relativement au monde du droit et de la justice

    Results from 2 cohort studies in central Africa show that clearance of Wuchereria bancrofti infection after repeated rounds of mass drug administration with albendazole alone is closely linked to individual adherence

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    BACKGROUND: Two community trials conducted from 2012 to 2018 in the Republic of Congo and the Democratic Republic of the Congo demonstrated the efficacy of semiannual mass drug administration (MDA) with albendazole (ALB) alone on lymphatic filariasis (LF). However, a high interindividual heterogeneity in the clearance of infection was observed. METHODS: We analyzed trial data to assess the effect of individual adherence to ALB MDA on clearance of circulating filarial antigenemia (CFA) and microfilaremia. Community residents were offered a single dose of ALB every 6 months and tested for LF with a rapid test for CFA at baseline and then annually. CFA test results were scored on a semiquantitative scale. At each round, microfilaremia was assessed in CFA-positive individuals. All CFA-positive individuals for whom at least 1 follow-up measure was available were included in the analyses. Parametric survival models were used to assess the influence of treatment adherence on LF infection indicators. RESULTS: Of 2658 individuals enrolled in the trials, 394 and 129 were eligible for analysis of CFA and microfilaremia clearance, respectively. After adjusting for age, sex, and initial CFA score, the predicted mean time for clearing CFA was shorter in persons who had taken 2 doses of ALB per year (3.9 years) than in persons who had taken 1 or 0 dose (4.4 and 5.3 years; P \u3c .001 for both). A similar pattern was observed for microfilaremia clearance. CONCLUSIONS: These results demonstrate a clear dose-response relationship for the effect of ALB on clearance of CFA and microfilaremia

    Faecalibacterium prausnitzii Skews Human DC to Prime IL10-Producing T Cells Through TLR2/6/JNK Signaling and IL-10, IL-27, CD39, and IDO-1 Induction

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    The human colonic mucosa contains regulatory type 1-like (Tr1-like, i.e., IL-10-secreting and Foxp3-negative) T cells specific for the gut Clostridium Faecalibacterium prausnitzii (F. prausnitzii), which are both decreased in Crohn's disease patients. These data, together with the demonstration, in mice, that colonic regulatory T cells (Treg) induced by Clostridium bacteria are key players in colon homeostasis, support a similar role for F. prausnitzii-specific Treg in the human colon. Here we assessed the mechanisms whereby F. prausnitzii induces human colonic Treg. We demonstrated that F. prausnitzii, but not related Clostridia, skewed human dendritic cells to prime IL-10-secreting T cells. Accordingly, F. prausnitzii induced dendritic cells to express a unique array of potent Tr1/Treg polarizing molecules: IL-10, IL-27, CD39, IDO-1, and PDL-1 and, following TLR4 stimulation, inhibited their up-regulation of costimulation molecules as well as their production of pro-inflammatory cytokines IL-12 (p35 and p40) and TNFα. We further showed that these potent tolerogenic effects relied on F. prausnitzii-induced TLR2/6 triggering, JNK signaling and CD39 ectonucleotidase activity, which was induced by IDO-1 and IL-27. These data, together with the presence of F. prausnitzii-specific Tr1-like Treg in the human colon, point out to dendritic cells polarization by F. prausnitzii as the first described cellular mechanism whereby the microbiota composition may affect human colon homeostasis. Identification of F. prausnitzii-induced mediators involved in Tr1-like Treg induction by dendritic cells opens therapeutic avenues for the treatment of inflammatory bowel diseases

    Conditions of malaria transmission in Dakar from 2007 to 2010

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    Background: Previous studies in Dakar have highlighted the spatial and temporal heterogeneity of Anopheles gambiae s.l. biting rates. In order to improve the knowledge of the determinants of malaria transmission in this city, the present study reports the results of an extensive entomological survey that was conducted in 45 areas in Dakar from 2007 to 2010. Methods: Water collections were monitored for the presence of anopheline larvae. Adult mosquitoes were sampled by human landing collection. Plasmodium falciparum circumsporozoite (CSP) protein indexes were measured by ELISA (enzyme-linked immunosorbent assay), and the entomological inoculation rates were calculated. Results: The presence of anopheline larvae were recorded in 1,015 out of 2,683 observations made from 325 water collections. A water pH of equal to or above 8.0, a water temperature that was equal to or above 30 degrees C, the absence of larvivorous fishes, the wet season, the presence of surface vegetation, the persistence of water and location in a slightly urbanised area were significantly associated with the presence of anopheline larvae and/or with a higher density of anopheline larvae. Most of the larval habitats were observed in public areas, i.e., freely accessible. A total of 496,310 adult mosquitoes were caught during 3096 person-nights, and 44967 of these specimens were identified as An. gambiae s.l. The mean An. gambiae s.l. human-biting rate ranged from 0.1 to 248.9 bites per person per night during the rainy season. Anopheles arabiensis (93.14%), Anopheles melas (6.83%) and An. gambiae s.s. M form (0.03%) were the three members of the An. gambiae complex. Fifty-two An. arabiensis and two An. melas specimens were CSP-positive, and the annual CSP index was 0.64% in 2007, 0.09% in 2008-2009 and 0.12% in 2009-2010. In the studied areas, the average EIR ranged from 0 to 17.6 infected bites per person during the entire transmission season. Conclusion: The spatial and temporal heterogeneity of An. gambiae s.l. larval density, adult human-biting rate (HBR) and malaria transmission in Dakar has been confirmed, and the environmental factors associated with this heterogeneity have been identified. These results pave the way for the creation of malaria risk maps and for a focused anti-vectorial control strategy

    Evaluation de l'intĂ©rĂȘt du dĂ©pistage nĂ©onatal de l'hyperplasie congĂ©nitale des surrĂ©nales chez le nouveau-nĂ© prĂ©maturĂ©

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    MalgrĂ© la contribution du dĂ©pistage nĂ©onatal de l hyperplasie congĂ©nitale des surrĂ©nales Ă  la prĂ©vention des dĂ©cĂšs nĂ©onataux par perte de sel et des erreurs d assignation du sexe en cas d ambiguĂŻtĂ© sexuelle, la frĂ©quence des faux positifs chez les prĂ©maturĂ©s alimente une controverse quant Ă  sa rĂ©alisation systĂ©matique dans cette population. L objectif de notre travail Ă©tait donc d Ă©valuer l intĂ©rĂȘt de ce dĂ©pistage chez le nouveau-nĂ© prĂ©maturĂ©. Tous les nouveau-nĂ©s prĂ©maturĂ©s atteints d hyperplasie congĂ©nitale des surrĂ©nales, nĂ©s en France entre le 1er janvier 1995 et le 31 dĂ©cembre 2010 ont Ă©tĂ© inclus. Les critĂšres de jugement Ă©taient la symptomatologie liĂ©e Ă  la maladie, et la contribution du dĂ©pistage Ă  la mise en Ă©vidence du diagnostic. Au total, 54 nouveau-nĂ©s ont Ă©tĂ© inclus ; 68,5% d entre eux prĂ©sentaient une symptomatologie liĂ©e Ă  l hyperplasie congĂ©nitale des surrĂ©nales (37/54), dont 20% une forme sĂ©vĂšre. Le dĂ©pistage a permis de poser le diagnostic pour 40% des prĂ©maturĂ©s de plus de 34 semaines d amĂ©norrhĂ©e, mais pour seulement 18,7% de ceux nĂ©s entre 28 et 34 semaines d amĂ©norrhĂ©e, et pour aucun des extrĂȘmes prĂ©maturĂ©s. Ainsi, nous avons montrĂ© que chez les nouveau-nĂ©s de moins de 28 semaines d amĂ©norrhĂ©e, l intĂ©rĂȘt du dĂ©pistage de l hyperplasie congĂ©nitale des surrĂ©nales Ă©tait nul, et faible pour ceux nĂ©s entre 28 et 34 semaines d amĂ©norrhĂ©e. Dans cette population, le dĂ©pistage ne doit plus ĂȘtre rĂ©alisĂ©. En revanche, il reste contributif pour les prĂ©maturĂ©s de plus deDIJON-BU MĂ©decine Pharmacie (212312103) / SudocSudocFranceF

    Schweizer Ansichten

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    SCHWEIZER ANSICHTEN Schweizer Ansichten ( - ) Einband ( - ) Lithografie 1 "Thun" - Lithografie 10 "Vue D'une scierie sur le Lace de Brienz" (1) Lithografie 11 "Grande Chute du Giesbach" - Lithografie 20 "Chute de L'aar å la Handeck. Vallée D'Oberhasli" (11) Lithografie 21 "Chateau de Zwingen" - Lithografie 30 "Chemin Et Inscription Pres Du Pont De Court" (21) Lithografie 31 "Pierre Pertius" - Lithografie 40 "Vue D'Une Partie Du Village De St. Gervais (31) Lithografie 41 "Vue Du Mont-Blanc Prise De Servoz" - Lithografie 50 "Isola Pescatorina, prise de l'Isola Bella" (41) Lithografie 51 "Vue Prise A Lugano" - Lithografie 57 "Défilé Du Stretto Stalvedro prés Airolo" (51) Wasserzeichen 1 ([1]) Wasserzeichen 2 ([2]) Wasserzeichen 3 ([3]) Wasserzeichen 4 ([4]) Wasserzeichen 5 ([5]) Wasserzeichen 6 ([6]

    Simulation des SystĂšmes d'Information des Smart Grids - Une approche par points de vue

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    National audienceWe propose to simulate the Information Systems of Smart Grids to validate / criticize the modeling choices of domain experts. We propose a viewpoint based approach regarding two aspects : information and dynamics. We add an integration viewpoint to maintain consistency and we use Model Driven Engineering techniques. Finally, we experience our approach on a Smart Grid use case.Nous proposons de simuler les SystÚmes d'Information des Smart Grids afin de vali-der/critiquer les choix de modélisation des experts métier. Nous proposons une approche par points de vue selon deux aspects information et dynamique tout en ajoutant un point de vue inté-gration pour le maintien de cohérence. Nous mettons à contribution les techniques l'Ingénierie Dirigée par les ModÚles, en particulier la transformation de modÚle. Enfin, nous éprouvons notre démarche sur un cas métier Smart Grid

    Génération automatique de rÚgles de corrélation pour la détection d'attaques complexes

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    National audienceDans les systÚmes d'information répartis, des systÚmes de corrélation sont nécessaires pour traiter le grand nombre d'alertes de sécurité élémentaires et y identifier des motifs d'attaques complexes. Cependant, la complexité du systÚme rend difficile l'écriture de rÚgles de corrélation à la fois précises et correctes. Dans ce papier, on se propose de montrer qu'il est possible, à partir d'un arbre d'attaque construit par un expert, de générer automatique-ment des rÚgles de corrélation exhaustives qui seraient fastidieuses et difficiles à énumérer à la main. Les rÚgles de corrélation ainsi générées sont étroitement liées aux caractéristiques du systÚme surveillé (topologie, services déployés, etc.). Ce processus de transformation est implémenté dans un prototype générant des rÚgles de corrélation exprimées dans le langage de description d'attaque ADeLe
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