Transcription factors link mouse WAP-T mammary tumors with human breast cancer.

Mouse models are important tools to decipher the molecular mechanisms of mammary carcinogenesis and to mimic the respective human disease. Despite sharing common phenotypic and genetic features, the proper translation of murine models to human breast cancer remains a challenging task. In a previous study we showed that in the SV40 transgenic WAP-T mice an active Met-pathway and epithelial-mesenchymal characteristics distinguish low- and high-grade mammary carcinoma. To assign these murine tumors to corresponding human tumors we here incorporated the analysis of expression of transcription factor (TF) coding genes and show that thereby a more accurate interspecies translation can be achieved. We describe a novel cross-species translation procedure and demonstrate that expression of unsupervised selected TFs, such as ELF5, HOXA5 and TFCP2L1, can clearly distinguish between the human molecular breast cancer subtypes-or as, for example, expression of TFAP2B between yet unclassified subgroups. By integrating different levels of information like histology, gene set enrichment, expression of differentiation markers and TFs we conclude that tumors in WAP-T mice exhibit similarities to both, human basal-like and non-basal-like subtypes. We furthermore suggest that the low- and high-grade WAP-T tumor phenotypes might arise from distinct cells of tumor origin. Our results underscore the importance of TFs as common cross-species denominators in the regulatory networks underlying mammary carcinogenesis.

An assurance-based model to holistically assess the information security posture

EXECUTIVE SUMMARY : Evaluating Information Security Posture within an organization is becoming a very complex task. Currently, the evaluation and assessment of Information Security are commonly performed using frameworks, methodologies and standards which often consider the various aspects of security independently. Unfortunately this is ineffective because it does not take into consideration the necessity of having a global and systemic multidimensional approach to Information Security evaluation. At the same time the overall security level is globally considered to be only as strong as its weakest link. This thesis proposes a model aiming to holistically assess all dimensions of security in order to minimize the likelihood that a given threat will exploit the weakest link. A formalized structure taking into account all security elements is presented; this is based on a methodological evaluation framework in which Information Security is evaluated from a global perspective. This dissertation is divided into three parts. Part One: Information Security Evaluation issues consists of four chapters. Chapter 1 is an introduction to the purpose of this research purpose and the Model that will be proposed. In this chapter we raise some questions with respect to "traditional evaluation methods" as well as identifying the principal elements to be addressed in this direction. Then we introduce the baseline attributes of our model and set out the expected result of evaluations according to our model. Chapter 2 is focused on the definition of Information Security to be used as a reference point for our evaluation model. The inherent concepts of the contents of a holistic and baseline Information Security Program are defined. Based on this, the most common roots-of-trust in Information Security are identified. Chapter 3 focuses on an analysis of the difference and the relationship between the concepts of Information Risk and Security Management. Comparing these two concepts allows us to identify the most relevant elements to be included within our evaluation model, while clearing situating these two notions within a defined framework is of the utmost importance for the results that will be obtained from the evaluation process. Chapter 4 sets out our evaluation model and the way it addresses issues relating to the evaluation of Information Security. Within this Chapter the underlying concepts of assurance and trust are discussed. Based on these two concepts, the structure of the model is developed in order to provide an assurance related platform as well as three evaluation attributes: "assurance structure", "quality issues", and "requirements achievement". Issues relating to each of these evaluation attributes are analysed with reference to sources such as methodologies, standards and published research papers. Then the operation of the model is discussed. Assurance levels, quality levels and maturity levels are defined in order to perform the evaluation according to the model. Part Two: Implementation of the Information Security Assurance Assessment Model (ISAAM) according to the Information Security Domains consists of four chapters. This is the section where our evaluation model is put into a welldefined context with respect to the four pre-defined Information Security dimensions: the Organizational dimension, Functional dimension, Human dimension, and Legal dimension. Each Information Security dimension is discussed in a separate chapter. For each dimension, the following two-phase evaluation path is followed. The first phase concerns the identification of the elements which will constitute the basis of the evaluation: ? Identification of the key elements within the dimension; ? Identification of the Focus Areas for each dimension, consisting of the security issues identified for each dimension; ? Identification of the Specific Factors for each dimension, consisting of the security measures or control addressing the security issues identified for each dimension. The second phase concerns the evaluation of each Information Security dimension by: ? The implementation of the evaluation model, based on the elements identified for each dimension within the first phase, by identifying the security tasks, processes, procedures, and actions that should have been performed by the organization to reach the desired level of protection; ? The maturity model for each dimension as a basis for reliance on security. For each dimension we propose a generic maturity model that could be used by every organization in order to define its own security requirements. Part three of this dissertation contains the Final Remarks, Supporting Resources and Annexes. With reference to the objectives of our thesis, the Final Remarks briefly analyse whether these objectives were achieved and suggest directions for future related research. Supporting resources comprise the bibliographic resources that were used to elaborate and justify our approach. Annexes include all the relevant topics identified within the literature to illustrate certain aspects of our approach. Our Information Security evaluation model is based on and integrates different Information Security best practices, standards, methodologies and research expertise which can be combined in order to define an reliable categorization of Information Security. After the definition of terms and requirements, an evaluation process should be performed in order to obtain evidence that the Information Security within the organization in question is adequately managed. We have specifically integrated into our model the most useful elements of these sources of information in order to provide a generic model able to be implemented in all kinds of organizations. The value added by our evaluation model is that it is easy to implement and operate and answers concrete needs in terms of reliance upon an efficient and dynamic evaluation tool through a coherent evaluation system. On that basis, our model could be implemented internally within organizations, allowing them to govern better their Information Security. RÉSUMÉ : Contexte général de la thèse L'évaluation de la sécurité en général, et plus particulièrement, celle de la sécurité de l'information, est devenue pour les organisations non seulement une mission cruciale à réaliser, mais aussi de plus en plus complexe. A l'heure actuelle, cette évaluation se base principalement sur des méthodologies, des bonnes pratiques, des normes ou des standards qui appréhendent séparément les différents aspects qui composent la sécurité de l'information. Nous pensons que cette manière d'évaluer la sécurité est inefficiente, car elle ne tient pas compte de l'interaction des différentes dimensions et composantes de la sécurité entre elles, bien qu'il soit admis depuis longtemps que le niveau de sécurité globale d'une organisation est toujours celui du maillon le plus faible de la chaîne sécuritaire. Nous avons identifié le besoin d'une approche globale, intégrée, systémique et multidimensionnelle de l'évaluation de la sécurité de l'information. En effet, et c'est le point de départ de notre thèse, nous démontrons que seule une prise en compte globale de la sécurité permettra de répondre aux exigences de sécurité optimale ainsi qu'aux besoins de protection spécifiques d'une organisation. Ainsi, notre thèse propose un nouveau paradigme d'évaluation de la sécurité afin de satisfaire aux besoins d'efficacité et d'efficience d'une organisation donnée. Nous proposons alors un modèle qui vise à évaluer d'une manière holistique toutes les dimensions de la sécurité, afin de minimiser la probabilité qu'une menace potentielle puisse exploiter des vulnérabilités et engendrer des dommages directs ou indirects. Ce modèle se base sur une structure formalisée qui prend en compte tous les éléments d'un système ou programme de sécurité. Ainsi, nous proposons un cadre méthodologique d'évaluation qui considère la sécurité de l'information à partir d'une perspective globale. Structure de la thèse et thèmes abordés Notre document est structuré en trois parties. La première intitulée : « La problématique de l'évaluation de la sécurité de l'information » est composée de quatre chapitres. Le chapitre 1 introduit l'objet de la recherche ainsi que les concepts de base du modèle d'évaluation proposé. La maniéré traditionnelle de l'évaluation de la sécurité fait l'objet d'une analyse critique pour identifier les éléments principaux et invariants à prendre en compte dans notre approche holistique. Les éléments de base de notre modèle d'évaluation ainsi que son fonctionnement attendu sont ensuite présentés pour pouvoir tracer les résultats attendus de ce modèle. Le chapitre 2 se focalise sur la définition de la notion de Sécurité de l'Information. Il ne s'agit pas d'une redéfinition de la notion de la sécurité, mais d'une mise en perspectives des dimensions, critères, indicateurs à utiliser comme base de référence, afin de déterminer l'objet de l'évaluation qui sera utilisé tout au long de notre travail. Les concepts inhérents de ce qui constitue le caractère holistique de la sécurité ainsi que les éléments constitutifs d'un niveau de référence de sécurité sont définis en conséquence. Ceci permet d'identifier ceux que nous avons dénommés « les racines de confiance ». Le chapitre 3 présente et analyse la différence et les relations qui existent entre les processus de la Gestion des Risques et de la Gestion de la Sécurité, afin d'identifier les éléments constitutifs du cadre de protection à inclure dans notre modèle d'évaluation. Le chapitre 4 est consacré à la présentation de notre modèle d'évaluation Information Security Assurance Assessment Model (ISAAM) et la manière dont il répond aux exigences de l'évaluation telle que nous les avons préalablement présentées. Dans ce chapitre les concepts sous-jacents relatifs aux notions d'assurance et de confiance sont analysés. En se basant sur ces deux concepts, la structure du modèle d'évaluation est développée pour obtenir une plateforme qui offre un certain niveau de garantie en s'appuyant sur trois attributs d'évaluation, à savoir : « la structure de confiance », « la qualité du processus », et « la réalisation des exigences et des objectifs ». Les problématiques liées à chacun de ces attributs d'évaluation sont analysées en se basant sur l'état de l'art de la recherche et de la littérature, sur les différentes méthodes existantes ainsi que sur les normes et les standards les plus courants dans le domaine de la sécurité. Sur cette base, trois différents niveaux d'évaluation sont construits, à savoir : le niveau d'assurance, le niveau de qualité et le niveau de maturité qui constituent la base de l'évaluation de l'état global de la sécurité d'une organisation. La deuxième partie: « L'application du Modèle d'évaluation de l'assurance de la sécurité de l'information par domaine de sécurité » est elle aussi composée de quatre chapitres. Le modèle d'évaluation déjà construit et analysé est, dans cette partie, mis dans un contexte spécifique selon les quatre dimensions prédéfinies de sécurité qui sont: la dimension Organisationnelle, la dimension Fonctionnelle, la dimension Humaine, et la dimension Légale. Chacune de ces dimensions et son évaluation spécifique fait l'objet d'un chapitre distinct. Pour chacune des dimensions, une évaluation en deux phases est construite comme suit. La première phase concerne l'identification des éléments qui constituent la base de l'évaluation: ? Identification des éléments clés de l'évaluation ; ? Identification des « Focus Area » pour chaque dimension qui représentent les problématiques se trouvant dans la dimension ; ? Identification des « Specific Factors » pour chaque Focus Area qui représentent les mesures de sécurité et de contrôle qui contribuent à résoudre ou à diminuer les impacts des risques. La deuxième phase concerne l'évaluation de chaque dimension précédemment présentées. Elle est constituée d'une part, de l'implémentation du modèle général d'évaluation à la dimension concernée en : ? Se basant sur les éléments spécifiés lors de la première phase ; ? Identifiant les taches sécuritaires spécifiques, les processus, les procédures qui auraient dû être effectués pour atteindre le niveau de protection souhaité. D'autre part, l'évaluation de chaque dimension est complétée par la proposition d'un modèle de maturité spécifique à chaque dimension, qui est à considérer comme une base de référence pour le niveau global de sécurité. Pour chaque dimension nous proposons un modèle de maturité générique qui peut être utilisé par chaque organisation, afin de spécifier ses propres exigences en matière de sécurité. Cela constitue une innovation dans le domaine de l'évaluation, que nous justifions pour chaque dimension et dont nous mettons systématiquement en avant la plus value apportée. La troisième partie de notre document est relative à la validation globale de notre proposition et contient en guise de conclusion, une mise en perspective critique de notre travail et des remarques finales. Cette dernière partie est complétée par une bibliographie et des annexes. Notre modèle d'évaluation de la sécurité intègre et se base sur de nombreuses sources d'expertise, telles que les bonnes pratiques, les normes, les standards, les méthodes et l'expertise de la recherche scientifique du domaine. Notre proposition constructive répond à un véritable problème non encore résolu, auquel doivent faire face toutes les organisations, indépendamment de la taille et du profil. Cela permettrait à ces dernières de spécifier leurs exigences particulières en matière du niveau de sécurité à satisfaire, d'instancier un processus d'évaluation spécifique à leurs besoins afin qu'elles puissent s'assurer que leur sécurité de l'information soit gérée d'une manière appropriée, offrant ainsi un certain niveau de confiance dans le degré de protection fourni. Nous avons intégré dans notre modèle le meilleur du savoir faire, de l'expérience et de l'expertise disponible actuellement au niveau international, dans le but de fournir un modèle d'évaluation simple, générique et applicable à un grand nombre d'organisations publiques ou privées. La valeur ajoutée de notre modèle d'évaluation réside précisément dans le fait qu'il est suffisamment générique et facile à implémenter tout en apportant des réponses sur les besoins concrets des organisations. Ainsi notre proposition constitue un outil d'évaluation fiable, efficient et dynamique découlant d'une approche d'évaluation cohérente. De ce fait, notre système d'évaluation peut être implémenté à l'interne par l'entreprise elle-même, sans recourir à des ressources supplémentaires et lui donne également ainsi la possibilité de mieux gouverner sa sécurité de l'information.

Insertion dans les soins après une première hospitalisation dans un secteur pour psychose [Linkage to care after first hospitalisation for psychosis]

BACKGROUND: First hospitalisation for a psychotic episode causes intense distress to patients and families, but offers an opportunity to make a diagnosis and start treatment. However, linkage to outpatient psychiatric care remains a notoriously difficult step for young psychotic patients, who frequently interrupt treatment after hospitalisation. Persistence of symptoms, and untreated psychosis may therefore remain a problem despite hospitalisation and proper diagnosis. With persisting psychotic symptoms, numerous complications may arise: breakdown in relationships, loss of family and social support, loss of employment or study interruption, denial of disease, depression, suicide, substance abuse and violence. Understanding mechanisms that might promote linkage to outpatient psychiatric care is therefore a critical issue, especially in early intervention in psychotic disorders. OBJECTIVE: To study which factors hinder or promote linkage of young psychotic patients to outpatient psychiatric care after a first hospitalisation, in the absence of a vertically integrated program for early psychosis. Method. File audit study of all patients aged 18 to 30 who were admitted for the first time to the psychiatric University Hospital of Lausanne in the year 2000. For statistical analysis, chi2 tests were used for categorical variables and t-test for dimensional variables; p<0.05 was considered as statistically significant. RESULTS: 230 patients aged 18 to 30 were admitted to the Lausanne University psychiatric hospital for the first time during the year 2000, 52 of them with a diagnosis of psychosis (23%). Patients with psychosis were mostly male (83%) when compared with non-psychosis patients (49%). Furthermore, they had (1) 10 days longer mean duration of stay (24 vs 14 days), (2) a higher rate of compulsory admissions (53% vs 22%) and (3) were more often hospitalised by a psychiatrist rather than by a general practitioner (83% vs 53%). Other socio-demographic and clinical features at admission were similar in the two groups. Among the 52 psychotic patients, 10 did not stay in the catchment area for subsequent treatment. Among the 42 psychotic patients who remained in the catchment area after discharge, 20 (48%) did not attend the scheduled or rescheduled outpatient appointment. None of the socio demographic characteristics were associated with attendance to outpatient appointments. On the other hand, voluntary admission and suicidal ideation before admission were significantly related to attending the initial appointment. Moreover, some elements of treatment seemed to be associated with higher likelihood to attend outpatient treatment: (1) provision of information to the patient regarding diagnosis, (2) discussion about the treatment plan between in- and outpatient staff, (3) involvement of outpatient team during hospitalisation, and (4) elaboration of concrete strategies to face basic needs, organise daily activities or education and reach for help in case of need. CONCLUSION: As in other studies, half of the patients admitted for a first psychotic episode failed to link to outpatient psychiatric care. Our study suggests that treatment rather than patient's characteristics play a critical role in this phenomenon. Development of a partnership and involvement of patients in the decision process, provision of good information regarding the illness, clear definition of the treatment plan, development of concrete strategies to cope with the illness and its potential complications, and involvement of the outpatient treating team already during hospitalisation, all came out as critical strategies to facilitate adherence to outpatient care. While the current rate of disengagement after admission is highly concerning, our finding are encouraging since they constitute strategies that can easily be implemented. An open approach to psychosis, the development of partnership with patients and a better coordination between inpatient and outpatient teams should therefore be among the targets of early intervention programs. These observations might help setting up priorities when conceptualising new programs and facilitate the implementation of services that facilitate engagement of patients in treatment during the critical initial phase of psychotic disorders.

IFN stimulated gene expression in the liver is a better predictor of treatment response in chronic hepatitis c than the IL28b (IFN lambda 3) genotype

Background: Therapy of chronic hepatitis C (CHC) with pegIFNa/ribavirin achieves sustained virologic response (SVR) in ~55%. Pre-activation of the endogenous interferon system in the liver is associated non-response (NR). Recently, genome-wide association studies described associations of allelic variants near the IL28B (IFNλ3) gene with treatment response and with spontaneous clearance of the virus. We investigated if the IL28B genotype determines the constitutive expression of IFN stimulated genes (ISGs) in the liver of patients with CHC. Methods: We genotyped 93 patients with CHC for 3 IL28B single nucleotide polymorphisms (SNPs, rs12979860, rs8099917, rs12980275), extracted RNA from their liver biopsies and quantified the expression of IL28B and of 8 previously identified classifier genes which discriminate between SVR and NR (IFI44L, RSAD2, ISG15, IFI22, LAMP3, OAS3, LGALS3BP and HTATIP2). Decision tree ensembles in the form of a random forest classifier were used to calculate the relative predictive power of these different variables in a multivariate analysis. Results: The minor IL28B allele (bad risk for treatment response) was significantly associated with increased expression of ISGs, and, unexpectedly, with decreased expression of IL28B. Stratification of the patients into SVR and NR revealed that ISG expression was conditionally independent from the IL28B genotype, i.e. there was an increased expression of ISGs in NR compared to SVR irrespective of the IL28B genotype. The random forest feature score (RFFS) identified IFI27 (RFFS = 2.93), RSAD2 (1.88) and HTATIP2 (1.50) expression and the HCV genotype (1.62) as the strongest predictors of treatment response. ROC curves of the IL28B SNPs showed an AUC of 0.66 with an error rate (ERR) of 0.38. A classifier with the 3 best classifying genes showed an excellent test performance with an AUC of 0.94 and ERR of 0.15. The addition of IL28B genotype information did not improve the predictive power of the 3-gene classifier. Conclusions: IL28B genotype and hepatic ISG expression are conditionally independent predictors of treatment response in CHC. There is no direct link between altered IFNλ3 expression and pre-activation of the endogenous system in the liver. Hepatic ISG expression is by far the better predictor for treatment response than IL28B genotype.

Transforming scientific information with everyday thinking: A social representations perspective

Cette thèse examine la circulation et l'intégration des informations scientifiques dans la pensée quotidienne d'après la théorie des représentations sociales (TRS). En tant qu'alternative aux approches traditionnelles de la communication de la science, les transformations survenant entre le discours scientifique et le discours de sens commun sont considérées comme adaptatives. Deux études sur la circulation des informations dans les media (études 1 et 2) montrent des variations dans les thèmes de discours exposés aux profanes, et parmi les discours de ceux-ci, en fonction de différentes sources. Ensuite, le processus d'ancrage dans le positionnement préalable envers la science est étudié, pour l'explication qu'il fournit de la réception et de la transmission d'informations scientifiques dans le sens commun. Les effets d'ancrage dans les attitudes et croyances préexistants sont reportés dans différents contextes de circulation des informations scientifiques (études 3 à 7), incluant des études de type corrélationnel, experimental et de terrain. Globalement, cette thèse procure des arguments en faveur de la pertinence de la TRS pour la recherche sur la communication de la science, et suggère des développements théoriques et méthodologiques pour ces deux domaines de recherche. Drawing on the social representations theory (SRT), this thesis examines the circulation and integration of scientific information into everyday thinking. As an alternative to the traditional approaches of science communication, it considers transformations between scientific and common-sense discourses as adaptive. Two studies, focused on the spreading of information into the media (Studies 1 and 2), show variations in the themes of discourses introduced to laypersons and in the themes among laypersons' discourses, according to different sources. Anchoring in prior positioning toward science is then studied for the explanation it provides on the reception and transmission of scientific information into common sense. Anchoring effects in prior attitudes and beliefs are reported in different contexts of circulation of scientific information (Studies 3 to 7) by using results from correlational, field, and experimental studies. Overall, this thesis provides arguments for the relevance of SRT in science communication research and suggests theoretical and methodological developments for both domains of research.

Using information from telephone panel surveys to predict reasons for refusal

One of the key problems in conducting surveys is convincing people to participate.¦However, it is often difficult or impossible to determine why people refuse. Panel surveys¦provide information from previous waves that can offer valuable clues as to why people¦refuse to participate. If we are able to anticipate the reasons for refusal, then we¦may be able to take appropriate measures to encourage potential respondents to participate¦in the survey. For example, special training could be provided for interviewers¦on how to convince potential participants to participate.¦This study examines different influences, as determined from the previous wave,¦on refusal reasons that were given by the respondents in the subsequent wave of the¦telephone Swiss Household Panel. These influences include socio-demography, social¦inclusion, answer quality, and interviewer assessment of question understanding and¦of future participation. Generally, coefficients are similar across reasons, and¦between-respondents effects rather than within-respondents effects are significant.¦While 'No interest' reasons are easier to predict, the other reasons are more situational. Survey-specific issues are able to distinguish¦different reasons to some extent.

A follow-up study on the quality of alcohol dependence-related information on the web.

ABSTRACT: In order to evaluate the one-year evolution of web-based information on alcohol dependence, we re-assessed alcohol-related sites in July 2007 with the same evaluating tool that had been used to assess these sites in June 2006. Websites were assessed with a standardized form designed to rate sites on the basis of accountability, presentation, interactivity, readability, and content quality. The DISCERN scale was also used, which aimed to assist persons without content expertise in assessing the quality of written health publications. Scores were highly stable for all components of the form one year later (r = .77 to .95, p &lt; .01). Analysis of variance for repeated measures showed no time effect, no interaction between time and scale, no interaction between time and group (affiliation categories), and no interaction between time, group, and scale. The study highlights lack of change of alcohol-dependence-related web pages across one year.

"MIATA"-minimal information about T cell assays.

Immunotherapy, especially therapeutic vaccination, has a great deal of potential in the treatment of cancer and certain infectious diseases such as HIV (Allison et al., 2006; Fauci et al., 2008; Feldmann and Steinman, 2005). Numerous vaccine candidates have been tested in patients with a variety of tumor types and chronic viral diseases. Often, the best way to assess the clinical potential of these vaccines is to monitor the induced T cell response, and yet there are currently no standards for reporting these results. This letter is an effort to address this problem.

Relations intergroupes : attribution à la discrimination et perception d'hostilité chez autrui

Résumé: La thèse que nous présentons s'intéresse aux phénomènes d'attribution d'intentions hostiles. Dodge (1980) observe que les individus agressifs ont tendance, en situation ambiguë, à sur-attribuer des intentions hostiles à leurs pairs, ce qui induit des réponses agressives. Pour l'auteur, l'attribution d'intentions hostiles est un médiateur entre certaines caractéristiques personnelles (l'agressivité) des individus, et le type de réponses qu'ils apportent aux situations. Cependant, les informations concernant l'appartenance groupale des "pairs" ne sont jamais prises en compte dans leurs études. Si ce processus est perméable à l'influence des normes et croyances (Bègue et Muller, 2006), aucune étude ne met en évidence quel serait l'impact d'informations groupales sur l'élaboration des réponses aux situations, dans le cadre de ce modèle. L'objectif de cette thèse est de montrer que l'attribution d'intentions hostiles peut être envisagée comme un processus agissant également à un niveau intergroupes et donc prenant en compte des informations groupales sur les individus. En s'inspirant du modèle de Dodge, nous avons émis l'hypothèse que les logiques intergroupes intervenaient dans l'interprétation des intentions des acteurs impliqués dans les interactions, afin de produire une réponse adaptée aux logiques intergroupes. Afin de tester cette hypothèse, nous avons suivi trois axes de recherches: Dans le premier de ces axes, nous avons introduit, dans le paradigme de Dodge, des informations .sur l'appartenance groupale des protagonistes de l'interaction (endogroupe vs exogroupe). Nous avons montré que le type de situation (ambiguë vs hostile) est moins important que l'information groupale dans la production d'une réponse à la situation (Étude 1). En outre, nous avons mis en évidence des processus différents selon la position des individus dans leur groupe (Étude 2). Dans le second axe, nous avons montré que si les différences de statut entre groupes n'influençaient pas directement le modèle de Dodge, elles interagissaient avec l'appartenance groupale et la clarté de la situation au niveau de l'attribution d'intentions hostiles (étude 3) et des intentions comportementales (Ettide 4). Dans le troisième et deriúer axe, nous avons introduit l'attribution d'intentions hostiles dans un processus de dévalorisation d'une cible expliquant un échec par la discrimination (Kaiser et Miller, 2001; 2003). Nous avons alors montré que l'attribution d'intentions hostiles médiatisait le lien entre l'attribution mobilisée pour expliquer l'événement et l'évaluation de la cible (Étude 5), et que ce type d'attribution était spécifique, aux intentions comportementales agressives (Études 6). Nous avons alors conclu sur la dimension sociale de l'attribution d'intentions hostiles et sur le fait qu'il s'agissait d'un élément permettant la construction d'une représentation des interactions sociales. Abstract The present thesis focuses on the phenomena of hostile intents attribution. Dodge (1980) observes that in ambiguous situations, aggressive people tend to over attribute hostile intents to others. This attribution leads them to respond aggressively. According to the author, hostile intents attribution mediates the link between some personal characteristics (aggressiveness for example) of individuals and their responses to the situation. However information related to participants group membership is always neglected in these studies. Begue and Muller (2006) showed that some beliefs could moderate the interaction between aggressiveness and hostile intents attribution on behaviors, but no study exhibited evidence of a similar effect with social information. The aim of this thesis is to show that hostile intents attribution needs to be considered at an intergroup level by taking into account people's group ineinbership. Based on the Dodge model, we formulated the hypothesis that intergroup strategies had an impact on actors' intents interpretations which in return should lead to different but adapted reactions to the situation. To test this hypothesis, three lines of research were developed. In the first line, we introduced, in the Dodge's paradigm, some information about the participants group membership (ingroup vs outgroup). We showed that when elaborating a response to a specific situation its nature (ambiguous vs hostile) had less impact than group membership information (Study 1). In addition, we highlighted some different processes according to the position of individuals in their group (Study 2). In the second line, we showed that if the differences between groups status didn't influence the Dodge model, they interacted with group membership and situation nature to influence hostile intents attribution (Study 3) and behaviors intents (Study 4). In the last line of research, we introduced hostile intents attribution within the process of derogation of a target explaining its failure by discrimination (Kaiser and Miller, 2001; 2003). We showed that hostile intents attribution mediated the link between the attibution mobilized to explain the failure and the derogation of the target (Study 5), and that this attribution type was specifically linked to aggressive behavior intents (Study 6). We finally concluded that hostile intents attribution imply an important social dimension which needs to be taken into account because involved in the construction of a representation of social interactions.

PKS2: A link between phototropin signalling and auxin transport - a study on how plants sense and respond to light.

The blue light photoreceptors phototropins (phot1 and phot2 in Arabidopsis thaliana (L.)) carry out various light responses of great adaptive value that optimize plant growth. These processes include phototropism (the bending of an organ induced by unequal light distribution), chloroplast movements, stomatal opening, leaf flattening and solar tracking. The biochemical pathways controlling these important blue light responses are just starting to be elucidated. The PHYTOCHROME KINASE SUBSTRATE (PKS1-4) proteins - the subject of this research - have recently been identified as novel phototropism signalling components. PKS1 (the founding member of this family) interacts in a same complex in vivo with phot1 and the important phot1 signalling element NON-PHOTOTROPIC HYPOCOTYL 3 (NPH3). This suggested that the PKS may act as early components of phot signalling. This work further investigates the role of this protein family during phototropin signalling Genetic experiments clearly showed that the PKS do not control chloroplast movements or stomatal opening. However, PKS2 plays a critical role with NPH3 during leaf flattening and solar tracking. Epistasis data indicated that both proteins act in phot1 and phot2 pathways, which is consistent with their in vivo interaction with both phototropins. Because phototropism, leaf flattening and solar tracking are developmental processes regulated by the hormone auxin, the role of PKS2 and NPH3 during auxin homeostasis was also investigated. Interestingly, PKS2 loss-of-function restores leaf flattening in the auxin transporter mutant aux1. Moreover, PKS2 and NPH3 are found in a same complex with AUX1 in vivo. Taken together, these results suggest that PKS2 may act with NPH3 as a connecting point between phot signalling and auxin transport. Further experiments were performed to explore the molecular mode of action of PKS2 and NPH3 in this process. The significance of these results is discussed.

The S. pombe cdc16 gene is required both for maintenance of p34cdc2 kinase activity and regulation of septum formation: a link between mitosis and cytokinesis?

In the fission yeast Schizosaccharomyces pombe, septum formation and cytokinesis are dependent upon the initiation, though not the completion of mitosis. A number of cell cycle mutants which show phenotypes consistent with a defect in the regulation of septum formation have been isolated. A mutation in the S. pombe cdc16 gene leads to the formation of multiple septa without cytokinesis, suggesting that the normal mechanisms that limit the cell to the formation of a single septum in each cycle do not operate. Mutations in the S. pombe early septation mutants cdc7, cdc11, cdc14 and cdc15 lead to the formation of elongated, multinucleate cells, as a result of S phase and mitosis continuing in the absence of cytokinesis. This suggests that in these cells, the normal mechanisms which initiate cytokinesis are defective and that they are unable to respond to this by preventing further nuclear cycles. Genetic analysis has implied that the products of some of these genes may interact with that of the cdc16 gene. To understand how the processes of septation and cytokinesis are regulated and coordinated with mitosis we are studying the early septation mutants and cdc16. In this paper, we present the cloning and analysis of the cdc16 gene. Deletion of the gene shows that it is essential for cell proliferation: spores lacking a functional cdc16 gene germinate, complete mitosis and form multiple septa without undergoing cell cleavage.(ABSTRACT TRUNCATED AT 250 WORDS)

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Developing a predictive understanding of subsurface flow and transport is complicated by the disparity of scales across which controlling hydrological properties and processes span. Conventional techniques for characterizing hydrogeological properties (such as pumping, slug, and flowmeter tests) typically rely on borehole access to the subsurface. Because their spatial extent is commonly limited to the vicinity near the wellbores, these methods often cannot provide sufficient information to describe key controls on subsurface flow and transport. The field of hydrogeophysics has evolved in recent years to explore the potential that geophysical methods hold for improving the quantification of subsurface properties and processes relevant for hydrological investigations. This chapter is intended to familiarize hydrogeologists and water-resource professionals with the state of the art as well as existing challenges associated with hydrogeophysics. We provide a review of the key components of hydrogeophysical studies, which include: geophysical methods commonly used for shallow subsurface characterization; petrophysical relationships used to link the geophysical properties to hydrological properties and state variables; and estimation or inversion methods used to integrate hydrological and geophysical measurements in a consistent manner. We demonstrate the use of these different geophysical methods, petrophysical relationships, and estimation approaches through several field-scale case studies. Among other applications, the case studies illustrate the use of hydrogeophysical approaches to quantify subsurface architecture that influence flow (such as hydrostratigraphy and preferential pathways); delineate anomalous subsurface fluid bodies (such as contaminant plumes); monitor hydrological processes (such as infiltration, freshwater-seawater interface dynamics, and flow through fractures); and estimate hydrological properties (such as hydraulic conductivity) and state variables (such as water content). The case studies have been chosen to illustrate how hydrogeophysical approaches can yield insights about complex subsurface hydrological processes, provide input that improves flow and transport predictions, and provide quantitative information over field-relevant spatial scales. The chapter concludes by describing existing hydrogeophysical challenges and associated research needs. In particular, we identify the area of quantitative watershed hydrogeophysics as a frontier area, where significant effort is required to advance the estimation of hydrological properties and processes (and their uncertainties) over spatial scales relevant to the management of water resources and contaminants.