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.

Extending contingency: the impact of strategy, technology, size and business environment on the organisational form of small Chinese firms

This paper is inspired by articles in the last decade or so that have argued for more attention to theory, and to empirical analysis, within the well-known, and long-lasting, contingency framework for explaining the organisational form of the firm. Its contribution is to extend contingency analysis in three ways: (a) by empirically testing it, using explicit econometric modelling (rather than case study evidence) involving estimation by ordered probit analysis; (b) by extending its scope from large firms to SMEs; (c) by extending its applications from Western economic contexts, to an emerging economy context, using field work evidence from China. It calibrates organizational form in a new way, as an ordinal dependent variable, and also utilises new measures of familiar contingency factors from the literature (i.e. Environment, Strategy, Size and Technology) as the independent variables. An ordered probit model of contingency was constructed, and estimated by maximum likelihood, using a cross section of 83 private Chinese firms. The probit was found to be a good fit to the data, and displayed significant coefficients with plausible interpretations for key variables under all the four categories of contingency analysis, namely Environment, Strategy, Size and Technology. Thus we have generalised the contingency model, in terms of specification, interpretation and applications area.

An axiomatization of difference-form contest success functions

This paper presents an axiomatic characterization of difference-form group contests, that is, contests fought among groups and where their probability of victory depends on the difference of their effective efforts. This axiomatization rests on the property of Equalizing Consistency, stating that the difference between winning probabilities in the grand contest and in the smaller contest should be identical across all participants in the smaller contest. This property overcomes some of the drawbacks of the widely-used ratio-form contest success functions. Our characterization shows that the criticisms commonly-held against difference-form contests success functions, such as lack of scale invariance and zero elasticity of augmentation, are unfounded.By clarifying the properties of this family of contest success functions, this axiomatization can help researchers to find the functional form better suited to their application of interest.

Some progress on the chemistry of natural bioactive terpenoids form Chinese medicinal plants

(1) Pseudolaric acids - Novel diterpenes, Pseudolaric acid A, B, C and D were isolated from Pseudolarix kaempferi Gorden (pinaceae). Their structures were assigned by spectroscopic data and chemical correlations. In the contineous studies, the absolute configurations, the conformations in the solutions, the framentation mechanisms of MS and assigments of all NMR spectral signals were also reported. They showed the antifungal and cytotoxic activities. (2) Daphnane diterpenes - In the further studies on the plants of Thymelaeaceae, besides 10 known diterpenes, 16 new daphnane diterpenes were isolated from Daphne genkwa, D. tangutica, D. giraldii, Wikstroemie chamaedaphne. They showed the antifertilities activities. (3) Tripterygium diterpenes 14 new diterpenes were isolated from Triperygium wilfordii, T. regeli and T. hypoglaucum. Some of them showed the antitumor activities. The CD spectra showed that A/B ring of all compoundshave trans configuration as same as tripdiolide and triptolide determined by X-ray diffraction (4) Pregnane glycosides from Marsdenia koi - Two new pregnane glycosides marsdenikoiside A and marsdenikoiside B which can terminate the early pregnancy were isolated from Marsdeia koi. Their structures were elucidated by hydrolysis and spectroscopic methods.

A medium for inducing conversion of Histoplasma capsulatum var. capsulatum into its yeast-like form

Histoplasma capsulatum var. capsulatum is a dimorphic fungus that, under special conditions, converts from its more common mycelial form to a yeast-like form. Achieving this conversion, however, has been problematical for researchers. The present study tested conversion rates in ten Histoplasma capsulatum var. capsulatum strains using seven culture media, four of wich were conventional and three novel. One of our novel media, MLGema, induced complete conversion, of two strains within five days of incubation at 35 degrees centigrades, and of all strains that eventually converted by the time of the second subculturing transfer, under defined experimental conditions. MLGema is also inexpensive and easy to produce.

A Modulated Closed Form solution for Quantitative Susceptibility Mapping - A thorough evaluation and comparison to iterative methods based on edge prior knowledge.

The aim of this study is to perform a thorough comparison of quantitative susceptibility mapping (QSM) techniques and their dependence on the assumptions made. The compared methodologies were: two iterative single orientation methodologies minimizing the l2, l1TV norm of the prior knowledge of the edges of the object, one over-determined multiple orientation method (COSMOS) and anewly proposed modulated closed-form solution (MCF). The performance of these methods was compared using a numerical phantom and in-vivo high resolution (0.65mm isotropic) brain data acquired at 7T using a new coil combination method. For all QSM methods, the relevant regularization and prior-knowledge parameters were systematically changed in order to evaluate the optimal reconstruction in the presence and absence of a ground truth. Additionally, the QSM contrast was compared to conventional gradient recalled echo (GRE) magnitude and R2* maps obtained from the same dataset. The QSM reconstruction results of the single orientation methods show comparable performance. The MCF method has the highest correlation (corrMCF=0.95, r(2)MCF =0.97) with the state of the art method (COSMOS) with additional advantage of extreme fast computation time. The l-curve method gave the visually most satisfactory balance between reduction of streaking artifacts and over-regularization with the latter being overemphasized when the using the COSMOS susceptibility maps as ground-truth. R2* and susceptibility maps, when calculated from the same datasets, although based on distinct features of the data, have a comparable ability to distinguish deep gray matter structures.

Description of the adult form of Nybelinia (Syngenes) rougetcampanae Dollfus, 1960 and some new data on n. (n.) bisculata (Linton, 1889) (Trypanorhyncha: Tentaculariidae)

The adult form of Nybelinia (Syngenes) rougetcampanae Dollfus, 1960 is described, parasitizing one specimen of Sphyrna lewni (Griffith & Smith, 1834) out of the five ones necropsied and one out of six Nothorhynchus pectorosus (Garman, 1884) was found harbouring N. (N.) bisculata (Linton, 1889). The finding of these cestodes under Trypanorhyncha in sharks captured off the coast of Rio Grande do Sul State, Brazil, amplifies their known geographical distribution and adds new host records for these parasites.

Influence of the host related factors in the development of the hepatosplenic form of schistosomiasis mansoni

The frequency of hepatosplenomegaly in endemic areas is not proportional to the fecal ova count. This may be explained by epidemiological genetic. The occurrence of two or more cases of schistosomal hepatosplenomegaly in nuclear family is much higher than expected. The concentration is higher among siblings than it is among mothers and children of further and children. It is not significant between father and mother. If the mother, instead of the father has hepatosplenic schistosomiasis the relative risk for the child to acquire hepatosplenomegaly is at least five times (the maternal affect). The inbreeding is highler in the hepatosplenic than in the hepatointestinal patients. In some areas in Brazil the hepatosplenic form of the schistosomiasis mansoni occurs with much higher frequency in whites than in blacks. After treatment, reversion of hepatosplenic schistosomiasis occurs more frequently in non-whithers. It seems that the resistance of blacks to the hepatosplenic form of schistosomiasis may be related to the glyoxalase system , perhaps associated to another genetic marker. The hepatosplenic schistosomiasis is less frequent in longilineal individuals. In some areas the hepatosplenic form of schistosomiasis is more frequent in A blood group of ABO sistem. The family heredograms do not suggest a single mendelian inheritance, but probably a multifactorial and possibility poligenic one.

The Perception of the Elements in the Hindu Traditions

The essays in this volume, contributions to an international symposium at the University of Lausanne in June 1998, represent the perception of the elements as a framework for the history of religions (Maya Burger), exemplified by the Hindu traditions. Each element is treated by a specialist in a different academic field in order to bring out a variety of approaches important to the discipline of the history of religion. Ether (akasa) was assigned to philosophy (Wilhelm Halbfass), wind to the history of religion (Bettina Bäumer), fire to classical philology (Peter Schreiner), water to a specialist on Indian medicine (Arion Rosu) and earth to anthropology (Gabriella Eichinger Ferro-Luzzi, specializing on Tamil literature). Les articles du présent volume, issus d'un symposium international ayant eu lieu à l'Université de Lausanne en juin 1998, présentent la perception des éléments comme base de recherche de l'étude des religions (Maya Burger), exemplifiée à l'aide des traditions hindoues. Chaque élément est traité par un spécialiste d'une discipline académique particulière dans le but de souligner la variété des approches nécessaire à la discipline d'histoire des religions. L'éther (akasa) a été considéré sous l'angle de la philosophie (Wilhelm Halbfass), le vent sous celui de l'histoire des religions (Bettina Bäumer), le feu sous celui de la philologie classique (Peter Schreiner), l'eau par un spécialiste de la médecine indienne (Arion Rosu) et la terre sous l'angle de l'anthropologie (Gabriella Eichinger Ferro-Luzzi, se concentrant sur la littérature tamoule).

The subclinical form of experimental visceral leishmaniasis in dogs

Pathological aspects of a subclinical form of experimental canine leishmaniasis is reported here for the first time. Fifteen mongrel dogs were used in the present study. Eight dogs were infected and seven were used as control. Four of the control dogs were inoculated with spleen cells from non-infected hamsters. The eight mongrel dogs inoculated intravenously with amastigotes forms of Leishmania chagasi envolved for periods as long as 25 months without any clinical characteristic sign of classical Visceral Leishmaniasis (VL). Most of the laboratory test results were compatible to those of the seven control animals but culture of bone marrow aspirated material and serologic testing (IIF) demonstrated or provided evidence that the animals were infected. The most important and predominant histopathological lesion in infected animals were epitheloid granulomas presented in the liver, spleen, adrenal gland and lung of some animals. Channels containing erythrocytes in some granulomas of the liver suggeste that these granulomas are formed inside sinusoidal capillaries. Despite the animals were proved to be infected and presented characteristic histologic lesions, they did not present external signs of disease. The granulomatous aspect of the lesions indicates a good immunologic reactivity and suggest that a host-parasite equilibrium does exist in the dog experimental model

Defining the site of light perception and initiation of phototropism in Arabidopsis.

Phototropism is an adaptive response allowing plants to optimize photosynthetic light capture. This is achieved by asymmetric growth between the shaded and lit sides of the stimulated organ. In grass seedlings, the site of phototropin-mediated light perception is distinct from the site of bending; however, in dicotyledonous plants (e.g., Arabidopsis), spatial aspects of perception remain debatable. We use morphological studies and genetics to show that phototropism can occur in the absence of the root, lower hypocotyl, hypocotyl apex, and cotyledons. Tissue-specific expression of the phototropin1 (phot1) photoreceptor demonstrates that light sensing occurs in the upper hypocotyl and that expression of phot1 in the hypocotyl elongation zone is sufficient to enable a normal phototropic response. Moreover, we show that efficient phototropism occurs when phot1 is expressed from endodermal, cortical, or epidermal cells and that its local activation rapidly leads to a global response throughout the seedling. We propose that spatial aspects in the steps leading from light perception to growth reorientation during phototropism differ between grasses and dicots. These results are important to properly interpret genetic experiments and establish a model connecting light perception to the growth response, including cellular and morphological aspects.

Expression of human estrogen receptor mutants in Xenopus oocytes: correlation between transcriptional activity and ability to form protein-DNA complexes.

The human estrogen receptor (hER) is a trans-acting regulatory protein composed of a series of discrete functional domains. We have microinjected an hER expression vector (HEO) into Xenopus oocyte nuclei and demonstrate, using Western blot assay, that the hER is synthesized. When nuclear extracts from oocytes were prepared and incubated in the presence of a 2.7 kb DNA fragment comprising the 5' end of the vitellogenin gene B2, formation of estrogen-dependent complexes could be visualized by electron microscopy over the estrogen responsive element (ERE). Of crucial importance is the observation that the complex formation is inhibited by the estrogen antagonist tamoxifen, is restored by the addition of the hormone and does not take place with extracts from control oocytes injected with the expression vector lacking the sequences encoding the receptor. The presence of the biologically active hER is confirmed in co-injection experiments, in which HEO is co-introduced with a CAT reporter gene under the control of a vitellogenin promoter containing or lacking the ERE. CAT assays and primer extensions analyses reveal that both the receptor and the ERE are essential for estrogen induced stimulation of transcription. The same approach was used to analyze selective hER mutants. We find that the DNA binding domain (region C) is essential for protein--DNA complex formation at the ERE but is not sufficient by itself to activate transcription from the reporter gene. In addition to region C, both the hormone binding (region E) and amino terminal (region A/B) domains are needed for an efficient transcription activation.(ABSTRACT TRUNCATED AT 250 WORDS)