56 research outputs found

    RETRATO DE JOVEN [Material grĂĄfico]

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    ADQUIRIDA POR EL COLECCIONISTA EN LAS PALMAS DE GRAN CANARIA.FOTO POSTAL DE RETRATO DE JOVEN (VISTA DE BUSTO)Copia digital. Madrid : Ministerio de EducaciĂłn, Cultura y Deporte. SubdirecciĂłn General de CoordinaciĂłn Bibliotecaria, 201

    Evaluation des Ă©missions de nitrate par les champs pour la conception de projets de territoire et l’accompagnement de la transition en aires d’alimentation de captage

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    Since the 2000’s the policy for the protection of catchment areas is based on territorial action plan, thesuccess of which is assessed by practices analysis. This assessment is mobilized to estimate pollutants emissions from fields (according to the cropping system) and the ability to maintain a good water quality. The methods for assessment of nitrate emissions was studied in territorial diagnosis of agricultural pressures in the catchment area of Saint Memmie (Marne) and in the setting up of the action plan in Brienon (Yonne).Nitrogen measurements in soil and the reporting of biomass and nitrogen quantities for crops are organized in an “observatory” of practices and cultivated fields’ states. They remain the most appropriate tool to estimate nitrates emissions and nitrogen dynamics but also to mobilize local actors. Simulation tools like Syst’N have a complementary role in extrapolating emissions from measurements to the whole territory, estimating nitrate leaching and expected water quality, like in a dashboard. They are also used to evaluate new cropping systems and scenarios for the territory.Depuis les annĂ©es 2000, la politique de protection des aires d'alimentation des captages (AAC) reposesur la rĂ©ussite de plans d’actions territoriaux, Ă©valuĂ©e par l’analyse des pratiques agricoles.Cette Ă©valuation est mobilisĂ©e lors des diagnostics et de la conception du plan d’action, pour estimer lesĂ©missions de polluants par les champs suivant leurs systĂšmes de culture, et la capacitĂ© du territoire Ă produire de l’eau de qualitĂ©. Les mĂ©thodes d’évaluation des Ă©missions de nitrate ont Ă©tĂ© Ă©tudiĂ©es dansle diagnostic territorial des pressions agricoles de l’AAC de Saint Memmie (Marne), puis dans laconstruction et la mise en oeuvre du plan d’action de l’AAC de Brienon (Yonne).OrganisĂ©es via un « observatoire » des pratiques et des Ă©tats des champs cultivĂ©s, les mesures d’azotedans le sol et les observations des biomasses et des quantitĂ©s d’azote qu’elles contiennent, restent lesoutils les plus pertinents pour estimer les Ă©missions de nitrates et la dynamique de l’azote comme pourmobiliser les agriculteurs et d’autres acteurs via des outils de mĂ©diation comme des « tours de plaine ».Les outils de simulation comme Syst’N ont un rĂŽle complĂ©mentaire pour extrapoler les Ă©missions denitrate au-delĂ  des quelques champs faisant l’objet de mesures, pour estimer le montant du lessivage etla qualitĂ© de l’eau Ă  attendre dans le territoire, par exemple dans un « tableau de bord » utile Ă l’apprentissage et Ă  l’aide Ă  la dĂ©cision des acteurs du territoire. Enfin ces simulations restent aussiessentielles pour Ă©valuer a priori les rĂ©sultats Ă  attendre de nouvelles façons de cultiver, ou d’unnouveau scĂ©nario de territoire

    Rapid Dissemination of SIV Follows Multisite Entry after Rectal Inoculation

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    Receptive ano-rectal intercourse is a major cause of HIV infection in men having sex with men and in heterosexuals. Current knowledge of the mechanisms of entry and dissemination during HIV rectal transmission is scarce and does not allow the development of preventive strategies. We investigated the early steps of rectal infection in rhesus macaques inoculated with the pathogenic isolate SIVmac251 and necropsied four hours to nine days later. All macaques were positive for SIV. Control macaques inoculated with heat-inactivated virus were consistently negative for SIV. SIV DNA was detected in the rectum as early as four hours post infection by nested PCR for gag in many laser-microdissected samples of lymphoid aggregates and lamina propria but never in follicle-associated epithelium. Scarce SIV antigen positive cells were observed by immunohistofluorescence in the rectum, among intraepithelial and lamina propria cells as well as in clusters in lymphoid aggregates, four hours post infection and onwards. These cells were T cells and non-T cells that were not epithelial cells, CD68+ macrophages, DC-SIGN+ cells or fascin+ dendritic cells. DC-SIGN+ cells carried infectious virus. Detection of Env singly spliced mRNA in the mucosa by nested RT-PCR indicated ongoing viral replication. Strikingly, four hours post infection colic lymph nodes were also infected in all macaques as either SIV DNA or infectious virus was recovered. Rapid SIV entry and dissemination is consistent with trans-epithelial transport. Virions appear to cross the follicle-associated epithelium, and also the digestive epithelium. Viral replication could however be more efficient in lymphoid aggregates. The initial sequence of events differs from both vaginal and oral infections, which implies that prevention strategies for rectal transmission will have to be specific. Microbicides will need to protect both digestive and follicle-associated epithelia. Vaccines will need to induce immunity in lymph nodes as well as in the rectum

    Les Ă©changes entre professionnels de l'Ă©ducation : entre soutien psychologique et acquisition de connaissances sur la pratique

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    Our research work takes its place in a psycho-ergonomic approach, and focuses on the wellbeing of people at work. Online discussion forums may provide a view of elements that endanger the personal balance of professionals. The study focuses on interactions on online forums involving professionals faced with issues in their work, and aims to understand what it is that forums may provide to their participants. The thesis we defend here is that these interactions aim both to provide psychological support to professionals, and to help these professionals acquire knowledge. Our work is based on three studies, carried out on two discussion forums intended for professionals in the field of education. The first study provides some elements to understand the inner workings of discussion forums, particularly concerning the motivational aspects of participant involvement. One hundred and ten users from two forums took part in an online survey. We observed eight types of motivation for getting involved in a forum for professionals. The second study aimed (1) to identify the nature of interactions in these communities and (2) to study the dynamics of interactions. We analysed thirteen discussions. Results showed that (1) self-disclosure is a characteristic present in the first message of discussion initiators, and that reacting participants rely on typical supportive behaviours (i.e. accounts of personal experiences, expressions of emotion, opinions, advice, search for concrete solutions, and explicit emotional support; (2) empathy manifests through the sharing of similar experiences. A study of the evolution of these online interactions highlights three key dynamics: making sense of the situation, searching for concrete solutions, and providing emotional support. These results suggest that these online communities aim to provide professionals with psychological support and to help them construct their professional practice. The third study aims to explore the subjective experience of participants during exchanges on the forum. We carried out auto-confrontation interviews followed by elicitation interviews with nine participants from the discussions we had analysed previously, based on written traces of these discussions. We observed discrepancies between what the participants share in their messages and the experiences expressed in interviews. Participants tend to conceal specific emotional states that are difficult to communicate, and sometimes disguise requests for emotional support as requests for advice. The interviews also revealed that the perception of support depends on three factors: (a) participants rely on various processes to assess other speakers' understanding of their situation; (b) participants construct representations of a speaker's competence; (c) sharing experiences is the most satisfying kind of support because it carries out several functions. Finally, our results show that participants are concerned with their anonymity and censor some information regarding antagonistic relationships with their colleagues and/or hierarchy in order to avoid potential repercussions. An overall analysis suggests that the motivations of participants taking part in an online forum are complex, multidimensional, and tangled. Secondly, interactions between professionals in an online forum may be viewed as a new means to cope with detrimental situations, making it easier to re-evaluate a situation and to solve problems. We discuss the results of this thesis from the points of view of the construction of knowledge on practice, of wellbeing at work, and of the interactional dynamics of supportive activities.Notre travail de recherche s'inscrit dans une visĂ©e psycho-ergonomique et s'intĂ©resse au bien-ĂȘtre des individus au travail. Les forums de discussion peuvent ĂȘtre le reflet de ce qui met en pĂ©ril l'Ă©quilibre des professionnels. L'Ă©tude s'intĂ©resse aux Ă©changes entre professionnels en difficultĂ© sur les forums et cherche Ă  comprendre ce qu'ils peuvent apporter aux participants. La thĂšse principale dĂ©fendue est que ces Ă©changes ont Ă  la fois une fonction de soutien psychologique et d'acquisition de connaissances. Le travail s'articule autour de trois Ă©tudes rĂ©alisĂ©es sur deux forums de discussion pour professionnels de l'Ă©ducation. La premiĂšre Ă©tude apporte des Ă©lĂ©ments de comprĂ©hension des forums de discussion notamment sur les aspects motivationnels des participants. Cent dix personnes rĂ©parties sur les deux forums ont rĂ©pondu Ă  une enquĂȘte en ligne. On observe huit types de motivations Ă  s'engager sur un forum de professionnels. La deuxiĂšme Ă©tude vise (1) Ă  identifier la nature des interactions dans ces communautĂ©s et (2) Ă  Ă©tudier la dynamique des Ă©changes. Treize discussions ont Ă©tĂ© analysĂ©es. Les rĂ©sultats ont mis en Ă©vidence (1) que le dĂ©voilement de soi est une caractĂ©ristique propre au premier message des initiateurs et que les rĂ©actants ont recours Ă  six comportements de soutien typiques (i.e. rĂ©cit d'expĂ©rience, expressions Ă©motionnelles, opinions, conseils, connaissances, soutien Ă©motionnel explicite). (2) l'empathie est traduite par du partage d'expĂ©rience similaire. L'Ă©tude de l'Ă©volution des Ă©changes a rĂ©vĂ©lĂ© trois dynamiques : l'Ă©laboration de sens, de recherche de solutions concrĂštes et de soutien Ă©motionnel. Ces rĂ©sultats montrent que ces communautĂ©s de professionnels en ligne ont une visĂ©e de soutien psychologique et de construction de sa pratique. La troisiĂšme Ă©tude cherche Ă  explorer le vĂ©cu subjectif des participants au moment des Ă©changes sur le forum. Des entretiens d'auto-confrontations avec relances d'entretien d'explicitation ont Ă©tĂ© menĂ©s avec neuf participants aux discussions analysĂ©es prĂ©cĂ©demment, Ă  partir des traces Ă©crites des discussions. On peut observer des dĂ©calages entre ce que les participants partagent dans leurs messages et ce qu'ils expriment avoir vĂ©cu (en entretien). Les participants masquent certains Ă©tats Ă©motionnels difficilement communicables ainsi que leurs attentes de soutien Ă©motionnel qu'ils dĂ©guisent parfois en demande de conseils. Les entretiens ont Ă©galement rĂ©vĂ©lĂ© que la perception du soutien est dĂ©pendante de trois facteurs : (a) le participant Ă©value la comprĂ©hension de son interlocuteur Ă  travers plusieurs processus; (b) le participant se construit une reprĂ©sentation des compĂ©tences de l'interlocuteur ; (c) Le partage d'expĂ©rience est le type de soutien le plus satisfaisant au sens oĂč il remplit de multiples fonctions. Enfin, les rĂ©sultats rĂ©vĂšlent que les participants craignent que leur anonymat soit levĂ© et censurent certaines informations sur eux-mĂȘmes, sur les relations conflictuelles avec leurs collĂšgues et leur hiĂ©rarchie afin d'Ă©viter d'Ă©ventuelles rĂ©percussions. L'analyse globale montre que les motivations des participants Ă  s'engager sur le forum sont complexes, multidimensionnelles et enchevĂȘtrĂ©es. D'autre part, les Ă©changes entre professionnels sur le forum peuvent ĂȘtre considĂ©rĂ©s comme un nouveau mode de coping qui favorise la rĂ©Ă©valuation de la situation et la rĂ©solution de problĂšme. Les rĂ©sultats de cette thĂšse sont discutĂ©s au regard des processus de construction de connaissances sur la pratique, du bien-ĂȘtre au travail et de la dynamique interactionnelle du soutien

    Exchanges between professionals on educational forums : between psychological support and skills acquisition on practice

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    La thĂšse s’inscrit dans une visĂ©e psycho-ergonomique et s’intĂ©resse au bien-ĂȘtre des individus au travail. L’étude s’intĂ©resse aux Ă©changes entre professionnels en difficultĂ© sur les forums et cherche Ă  comprendre ce qu’ils peuvent apporter aux participants. La thĂšse principale dĂ©fendue est que ces Ă©changes ont Ă  la fois une fonction de soutien psychologique et d’acquisition de connaissances. Trois Ă©tudes ont Ă©tĂ© rĂ©alisĂ©es sur deux forums pour professionnels de l’éducation. La premiĂšre Ă©tude met en Ă©vidence, Ă  l’aide d’une enquĂȘte en ligne, huit types de motivations Ă  s’engager sur un forum de professionnels. La deuxiĂšme Ă©tude vise Ă  identifier la nature des interactions et la dynamique des Ă©changes. Treize discussions ont Ă©tĂ© finement analysĂ©es. Les rĂ©sultats mettent en Ă©vidence des caractĂ©ristiques propres aux messages des initiateurs et des rĂ©actants. L’étude de l’évolution des Ă©changes rĂ©vĂšle trois dynamiques : l’élaboration de sens, de recherche de solutions concrĂštes et de soutien Ă©motionnel. La troisiĂšme Ă©tude cherche Ă  explorer le vĂ©cu subjectif des participants au moment des Ă©changes sur le forum. Des entretiens d’auto-confrontations avec relances d’entretien d’explicitation ont Ă©tĂ© menĂ©s avec neuf participants aux discussions analysĂ©es prĂ©cĂ©demment, Ă  partir des traces Ă©crites des discussions. On peut observer des dĂ©calages entre ce que les participants partagent dans leurs messages et ce qu’ils expriment avoir vĂ©cu (en entretien) notamment au niveau des Ă©motions, des attentes et des Ă©valuations du soutien. De plus, les participants craignent que leur anonymat soit levĂ© et censurent certaines informations afin d’éviter d’éventuelles rĂ©percussions.The study focuses on interactions on online forums involving professionals faced with issues in their work, and aims to understand what it is that forums may provide to their participants. The thesis we defend here is that these interactions aim both to provide psychological support to professionals, and to help these professionals acquire knowledge. Three studies were carried out on two discussion forums intended for professionals in the field of education.The first study highlights eight types of motivation for getting involved in a forum for professionals with an online survey. The second study aimed to identify the nature of interactions and the dynamics of interactions. We analysed thirteen discussions. The results highlight the specific characteristics of messages initiators and reactants. The study of the evolution of the interactions highlights three key dynamics: making sense of the situation, searching for concrete solutions, and providing emotional support. The third study aims to explore the subjective experience of participants during exchanges on the forum. We carried out auto-confrontation interviews followed by elicitation interviews with nine participants from the discussions we had analysed previously, based on written traces of these discussions. We observed discrepancies between what the participants share in their messages and the experiences expressed in interviews especially the emotional states, the request for emotional support and the perception of support. Finally, the participants are concerned with their anonymity and censor some information in order to avoid potential repercussions

    Les Ă©changes entre professionnels de l'Ă©ducation sur les forums de discussion entre soutien psychologique et acquisition de connaissances sur la pratique : entre soutien psychologique et acquisition de connaissances sur la pratique

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    The study focuses on interactions on online forums involving professionals faced with issues in their work, and aims to understand what it is that forums may provide to their participants. The thesis we defend here is that these interactions aim both to provide psychological support to professionals, and to help these professionals acquire knowledge. Three studies were carried out on two discussion forums intended for professionals in the field of education.The first study highlights eight types of motivation for getting involved in a forum for professionals with an online survey. The second study aimed to identify the nature of interactions and the dynamics of interactions. We analysed thirteen discussions. The results highlight the specific characteristics of messages initiators and reactants. The study of the evolution of the interactions highlights three key dynamics: making sense of the situation, searching for concrete solutions, and providing emotional support. The third study aims to explore the subjective experience of participants during exchanges on the forum. We carried out auto-confrontation interviews followed by elicitation interviews with nine participants from the discussions we had analysed previously, based on written traces of these discussions. We observed discrepancies between what the participants share in their messages and the experiences expressed in interviews especially the emotional states, the request for emotional support and the perception of support. Finally, the participants are concerned with their anonymity and censor some information in order to avoid potential repercussions.La thĂšse s’inscrit dans une visĂ©e psycho-ergonomique et s’intĂ©resse au bien-ĂȘtre des individus au travail. L’étude s’intĂ©resse aux Ă©changes entre professionnels en difficultĂ© sur les forums et cherche Ă  comprendre ce qu’ils peuvent apporter aux participants. La thĂšse principale dĂ©fendue est que ces Ă©changes ont Ă  la fois une fonction de soutien psychologique et d’acquisition de connaissances. Trois Ă©tudes ont Ă©tĂ© rĂ©alisĂ©es sur deux forums pour professionnels de l’éducation. La premiĂšre Ă©tude met en Ă©vidence, Ă  l’aide d’une enquĂȘte en ligne, huit types de motivations Ă  s’engager sur un forum de professionnels. La deuxiĂšme Ă©tude vise Ă  identifier la nature des interactions et la dynamique des Ă©changes. Treize discussions ont Ă©tĂ© finement analysĂ©es. Les rĂ©sultats mettent en Ă©vidence des caractĂ©ristiques propres aux messages des initiateurs et des rĂ©actants. L’étude de l’évolution des Ă©changes rĂ©vĂšle trois dynamiques : l’élaboration de sens, de recherche de solutions concrĂštes et de soutien Ă©motionnel. La troisiĂšme Ă©tude cherche Ă  explorer le vĂ©cu subjectif des participants au moment des Ă©changes sur le forum. Des entretiens d’auto-confrontations avec relances d’entretien d’explicitation ont Ă©tĂ© menĂ©s avec neuf participants aux discussions analysĂ©es prĂ©cĂ©demment, Ă  partir des traces Ă©crites des discussions. On peut observer des dĂ©calages entre ce que les participants partagent dans leurs messages et ce qu’ils expriment avoir vĂ©cu (en entretien) notamment au niveau des Ă©motions, des attentes et des Ă©valuations du soutien. De plus, les participants craignent que leur anonymat soit levĂ© et censurent certaines informations afin d’éviter d’éventuelles rĂ©percussions

    How could social media support farmers concerned with sustainability issues?

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    International audienceThis article aims to contribute to building an understanding of how social media may support farmers in transition to a more sustainable agriculture

    Les Ă©changes virtuels entre agriculteurs: un soutien Ă  leurs transitions professionnelles?

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    Face aux pressions lĂ©gales, Ă©conomiques et sociĂ©tales, de nombreux agriculteurs se sont engagĂ©s dans une transition professionnelle en direction d’une agriculture biologique. BĂ©nĂ©ficiant de peu de soutien formel, des groupes se sont organisĂ©s sur internet notamment sous la forme de forums de discussion. Les auteures proposent une analyse des Ă©changes dans l’un de ces forums, rĂ©unissant un corpus de plus de trois-cents messages. Les rĂ©sultats montrent que les Ă©changes constituent de vĂ©ritables espaces de conception de solutions, qui sont proposĂ©es, testĂ©es et discutĂ©es
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