95 research outputs found

    L'intention du consommateur de s'immerger dans les mondes virtuels : l'influence de la présence d'interactions sociales, de la persistance et de l'avatar

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    The object of this research is to study the antecedents of the consumer’s intention of MMO/MMORPG by supporting the definition of Bell (2008), which is offering a consensus on the definition of the virtual worlds. By this definition, all the virtual worlds have three concepts which are inherent to them: the presence of social interactions, persistence and avatar. We adapted the model of technological acceptance by representing these three concepts by social identity at which we distinguished the MMO community and the Guild community, perception of the flow and avatar. Our work follows a hypothetico-deductive method, which was formalized by the development of a qualitative and a quantitative analysis, using structural equations method. The results showed that the motivational factors (Yee 2007) of achievement and immersion influence significantly and positively the personalization of the determinants of the avatar (physique, clothing and attitudes), a contrario of the factor of sociability which influences it negatively. The three concepts which are inherent to virtual worlds have a positive influence on the attitude which, itself, influences positively the intention. Our adaptation of the model of technological acceptance, by jointly integrating the three concepts of the MMO/MMORPG which are social identity, perception of the flow and personalization of the criteria of the avatar, explains to 27,4% the consumer’s intention of virtual worlds.L’objet de cette recherche est d’étudier les antécédents de l’intention du consommateur de MMO/MMORPG en nous appuyant sur la définition de Bell (2008), qui propose un consensus quant à la définition des mondes virtuels. Par cette définition, tous les mondes virtuels possèdent trois concepts qui leur sont inhérents : la présence d’interactions sociales, la persistance et l’avatar. Nous avons adapté le modèle de l’acceptation technologique en représentant ces trois concepts par l’identité sociale pour laquelle nous distinguons la communauté du MMO et la communauté de la guilde, la perception du flow et l’avatar. Notre travail suit une démarche hypothético-déductive, qui s’est formalisée par l’élaboration d’une analyse qualitative et d’une analyse quantitative, en utilisant les équations structurelles.Les résultats ont montré que les facteurs motivationnels (Yee 2007) d’accomplissement et d’immersion influencent significativement et positivement la personnalisation des déterminants de l’avatar (le physique, l’habillement et les attitudes), a contrario du facteur de sociabilité qui l’influence négativement. Les trois concepts inhérents aux mondes virtuels ont une influence positive sur l’attitude qui, elle-même, influence positivement l’intention. Notre adaptation du modèle de l’acceptation technologique, en intégrant conjointement les trois concepts des MMO/MMORPG que sont l’identité sociale, la perception du flow et la personnalisation des critères de l’avatar, explique à 27,4 % l’intention du consommateur de mondes virtuels

    Arabidopsis CSP41 proteins form multimeric complexes that bind and stabilize distinct plastid transcripts

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    The spinach CSP41 protein has been shown to bind and cleave chloroplast RNA in vitro. Arabidopsis thaliana, like other photosynthetic eukaryotes, encodes two copies of this protein. Several functions have been described for CSP41 proteins in Arabidopsis, including roles in chloroplast rRNA metabolism and transcription. CSP41a and CSP41b interact physically, but it is not clear whether they have distinct functions. It is shown here that CSP41b, but not CSP41a, is an essential and major component of a specific subset of RNA-binding complexes that form in the dark and disassemble in the light. RNA immunoprecipitation and hybridization to gene chips (RIP-chip) experiments indicated that CSP41 complexes can contain chloroplast mRNAs coding for photosynthetic proteins and rRNAs (16S and 23S), but no tRNAs or mRNAs for ribosomal proteins. Leaves of plants lacking CSP41b showed decreased steady-state levels of CSP41 target RNAs, as well as decreased plastid transcription and translation rates. Representative target RNAs were less stable when incubated with broken chloroplasts devoid of CSP41 complexes, indicating that CSP41 proteins can stabilize target RNAs. Therefore, it is proposed that (i) CSP41 complexes may serve to stabilize non-translated target mRNAs and precursor rRNAs during the night when the translational machinery is less active in a manner responsive to the redox state of the chloroplast, and (ii) that the defects in translation and transcription in CSP41 protein-less mutants are secondary effects of the decreased transcript stability

    Elimination of a group II intron from a plastid gene causes a mutant phenotype

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    Group II introns are found in bacteria and cell organelles (plastids, mitochondria) and are thought to represent the evolutionary ancestors of spliceosomal introns. It is generally believed that group II introns are selfish genetic elements that do not have any function. Here, we have scrutinized this assumption by analyzing two group II introns that interrupt a plastid gene (ycf3) involved in photosystem assembly. Using stable transformation of the plastid genome, we have generated mutant plants that lack either intron 1 or intron 2 or both. Interestingly, the deletion of intron 1 caused a strong mutant phenotype. We show that the mutants are deficient in photosystem I and that this deficiency is directly related to impaired ycf3 function. We further show that, upon deletion of intron 1, the splicing of intron 2 is strongly inhibited. Our data demonstrate that (i) the loss of a group II intron is not necessarily phenotypically neutral and (ii) the splicing of one intron can depend on the presence of another

    The intention of consumer to immerse himself in virtual worlds : the influence of the presence of social interactions, persistence and the avatar.

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    L’objet de cette recherche est d’étudier les antécédents de l’intention du consommateur de MMO/MMORPG en nous appuyant sur la définition de Bell (2008), qui propose un consensus quant à la définition des mondes virtuels. Par cette définition, tous les mondes virtuels possèdent trois concepts qui leur sont inhérents : la présence d’interactions sociales, la persistance et l’avatar. Nous avons adapté le modèle de l’acceptation technologique en représentant ces trois concepts par l’identité sociale pour laquelle nous distinguons la communauté du MMO et la communauté de la guilde, la perception du flow et l’avatar. Notre travail suit une démarche hypothético-déductive, qui s’est formalisée par l’élaboration d’une analyse qualitative et d’une analyse quantitative, en utilisant les équations structurelles.Les résultats ont montré que les facteurs motivationnels (Yee 2007) d’accomplissement et d’immersion influencent significativement et positivement la personnalisation des déterminants de l’avatar (le physique, l’habillement et les attitudes), a contrario du facteur de sociabilité qui l’influence négativement. Les trois concepts inhérents aux mondes virtuels ont une influence positive sur l’attitude qui, elle-même, influence positivement l’intention. Notre adaptation du modèle de l’acceptation technologique, en intégrant conjointement les trois concepts des MMO/MMORPG que sont l’identité sociale, la perception du flow et la personnalisation des critères de l’avatar, explique à 27,4 % l’intention du consommateur de mondes virtuels.The object of this research is to study the antecedents of the consumer’s intention of MMO/MMORPG by supporting the definition of Bell (2008), which is offering a consensus on the definition of the virtual worlds. By this definition, all the virtual worlds have three concepts which are inherent to them: the presence of social interactions, persistence and avatar. We adapted the model of technological acceptance by representing these three concepts by social identity at which we distinguished the MMO community and the Guild community, perception of the flow and avatar. Our work follows a hypothetico-deductive method, which was formalized by the development of a qualitative and a quantitative analysis, using structural equations method. The results showed that the motivational factors (Yee 2007) of achievement and immersion influence significantly and positively the personalization of the determinants of the avatar (physique, clothing and attitudes), a contrario of the factor of sociability which influences it negatively. The three concepts which are inherent to virtual worlds have a positive influence on the attitude which, itself, influences positively the intention. Our adaptation of the model of technological acceptance, by jointly integrating the three concepts of the MMO/MMORPG which are social identity, perception of the flow and personalization of the criteria of the avatar, explains to 27,4% the consumer’s intention of virtual worlds
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