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    <title>HAL : Dernières publications</title>
    <description>HAL : Dernières publications</description>
    <pubDate>Wed, 27 Jun 2018 17:51:39 +0200</pubDate>
    <generator>HAL 3 (https://hal.archives-ouvertes.fr/)</generator>
    <link>https://hal.archives-ouvertes.fr/search/univ-montpellier/?omitHeader=true&amp;q=%2A&amp;fq=collCode_s%3AUNIV-MONTPELLIER&amp;fq=NOT+status_i%3A111&amp;fq=%7B%21tag%3Dtag0__submitType_s%7DsubmitType_s%3A%28%22file%22%29&amp;defType=edismax&amp;rows=50</link>
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    <item>
      <title>[hal-00757107] Le climat, un facteur de risque pour la santé en Afrique de l'Ouest.</title>
      <description><![CDATA[Cet article fait le point sur certaines connaissances acquises dans le cadre du programme AMMA (phase 1) au sujet des impacts de la variabilité climatique sur la santé en Afrique de l'Ouest. Les auteurs ont travaillé d'une part sur les maladies sévissant majoritairement en saison des pluies, à vecteur tel que le paludisme à Plasmodium falciparum, ou non comme le choléra, et d'autre part sur les maladies respiratoires et non vectorielles, telles que les méningites bactériennes à méningocoques à Neisseira Meningitidis, qui sévissent en plein coeur de la saison sèche. Le paludisme est connu pour sa relation à l'eau et à la température, indispensable pour le développement de son vecteur et son parasite. Le choléra, bien que lié à l'eau, peut aussi être observé en saison sèche : le lien entre choléra et environnement mérite donc un état des lieux éclairé par les nouveaux paramètres et outils disponibles aujourd'hui du côté du climat. L'intensité de la saison de la méningite est très liée aux conditions de vent et d'humidité prédominants en octobre-novembre de l'année précédente. Son démarrage est en phase avec le maximum de l'hiver et l'arrivée des grands événements de poussières dans les basses couches atmosphériques. Enfin, son arrêt est très lié à l'arrivée de la mousson. Ces résultats marquent une étape importante dans la mise en place de systèmes d'alerte précoce.]]></description>
      <pubDate>Wed, 27 Jun 2018 16:46:19 +0000</pubDate>
      <link>https://hal.archives-ouvertes.fr/hal-00757107</link>
      <guid>https://hal.archives-ouvertes.fr/hal-00757107</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Nadège Martiny)</author>
      <dc:creator>Nadège Martiny</dc:creator>
      <content:encoded><![CDATA[Cet article fait le point sur certaines connaissances acquises dans le cadre du programme AMMA (phase 1) au sujet des impacts de la variabilité climatique sur la santé en Afrique de l'Ouest. Les auteurs ont travaillé d'une part sur les maladies sévissant majoritairement en saison des pluies, à vecteur tel que le paludisme à Plasmodium falciparum, ou non comme le choléra, et d'autre part sur les maladies respiratoires et non vectorielles, telles que les méningites bactériennes à méningocoques à Neisseira Meningitidis, qui sévissent en plein coeur de la saison sèche. Le paludisme est connu pour sa relation à l'eau et à la température, indispensable pour le développement de son vecteur et son parasite. Le choléra, bien que lié à l'eau, peut aussi être observé en saison sèche : le lien entre choléra et environnement mérite donc un état des lieux éclairé par les nouveaux paramètres et outils disponibles aujourd'hui du côté du climat. L'intensité de la saison de la méningite est très liée aux conditions de vent et d'humidité prédominants en octobre-novembre de l'année précédente. Son démarrage est en phase avec le maximum de l'hiver et l'arrivée des grands événements de poussières dans les basses couches atmosphériques. Enfin, son arrêt est très lié à l'arrivée de la mousson. Ces résultats marquent une étape importante dans la mise en place de systèmes d'alerte précoce.]]></content:encoded>
    </item>
    <item>
      <title>[hal-01715818] Des formateurs d'enseignants à l'épreuve d'une réforme : crise(s) et reconfigurations potentielles</title>
      <description><![CDATA[En France, la période de mise en oeuvre d’une réforme de la formation des enseignants, initiée à la rentrée 2010, engage une redéfinition plus ou moins importante du travail des formateurs au sein des IUFM. Le recrutement des enseignants à un niveau Master nécessite la prise en compte de logiques multiples et parfois concurrentes. En mai 2011, un questionnaire en ligne a été proposé à l’ensemble des IUFM du territoire national. Les 584 réponses soulignent un brouillage identitaire et une crise de sens pour de nombreux formateurs en prise avec une réalité à laquelle ils sont contraints de s’adapter. Par ailleurs, des signes de souffrance au travail émergent. Ils indiquent dans quelle mesure les remaniements de la sphère du travail semblent intimement liés au système de valeurs de chaque professionnel mais aussi aux dynamiques locales et collectives dans lesquelles ce dernier inscrit son action au quotidien.]]></description>
      <pubDate>Wed, 27 Jun 2018 16:10:02 +0000</pubDate>
      <link>https://hal.umontpellier.fr/hal-01715818</link>
      <guid>https://hal.umontpellier.fr/hal-01715818</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Thérèse Perez-Roux)</author>
      <dc:creator>Thérèse Perez-Roux</dc:creator>
      <content:encoded><![CDATA[En France, la période de mise en oeuvre d’une réforme de la formation des enseignants, initiée à la rentrée 2010, engage une redéfinition plus ou moins importante du travail des formateurs au sein des IUFM. Le recrutement des enseignants à un niveau Master nécessite la prise en compte de logiques multiples et parfois concurrentes. En mai 2011, un questionnaire en ligne a été proposé à l’ensemble des IUFM du territoire national. Les 584 réponses soulignent un brouillage identitaire et une crise de sens pour de nombreux formateurs en prise avec une réalité à laquelle ils sont contraints de s’adapter. Par ailleurs, des signes de souffrance au travail émergent. Ils indiquent dans quelle mesure les remaniements de la sphère du travail semblent intimement liés au système de valeurs de chaque professionnel mais aussi aux dynamiques locales et collectives dans lesquelles ce dernier inscrit son action au quotidien.]]></content:encoded>
    </item>
    <item>
      <title>[hal-01715819] Place des élèves et de leur réussite scolaire dans la construction de la professionnalité chez les futurs enseignants de lycée professionnel</title>
      <description><![CDATA[Included in a comprehensive approach of the professional identity of teachers in vocational schools, this article deals more particularly with the kind of relations these teachers build with their pupils. The study is based on questionnaires followed by semi-directive interviews of five groups of teachers in a teachers’ training college. (IUFM) The results highlight the teachers’ ethics as regards education including a specific attention to the relation to learning and knowledge which the pupils have built, notably during their previous experience of school. Having to deal with a tension between the curiculum and how receptive the pupils are to learning, the vocational school teachers insist on how important the relation they have with their pupils is in their work. Concerned both by the necessity to prepare the pupils for the world of work and their desire to help them learn step by step, they endeavour to act consistently and undertake their mission of education and vocational/technical training.]]></description>
      <pubDate>Wed, 27 Jun 2018 16:10:02 +0000</pubDate>
      <link>https://hal.umontpellier.fr/hal-01715819</link>
      <guid>https://hal.umontpellier.fr/hal-01715819</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Thérèse Perez-Roux)</author>
      <dc:creator>Thérèse Perez-Roux</dc:creator>
      <content:encoded><![CDATA[Included in a comprehensive approach of the professional identity of teachers in vocational schools, this article deals more particularly with the kind of relations these teachers build with their pupils. The study is based on questionnaires followed by semi-directive interviews of five groups of teachers in a teachers’ training college. (IUFM) The results highlight the teachers’ ethics as regards education including a specific attention to the relation to learning and knowledge which the pupils have built, notably during their previous experience of school. Having to deal with a tension between the curiculum and how receptive the pupils are to learning, the vocational school teachers insist on how important the relation they have with their pupils is in their work. Concerned both by the necessity to prepare the pupils for the world of work and their desire to help them learn step by step, they endeavour to act consistently and undertake their mission of education and vocational/technical training.]]></content:encoded>
    </item>
    <item>
      <title>[hal-01715821] La démocratisation de l'accès aux grandes écoles Vers une nouvelle professionnalité enseignante ?</title>
      <description><![CDATA[Dans le cadre d'une recherche sur les disparités d'accès aux classes préparatoires aux grandes écoles, nous analysons la manière dont les enseignants investissent leur travail auprès des élèves et répondent de façon différenciée aux principes de justice et d'efficacité auxquels ils sont simultanément confrontés. Les résultats témoignent d'une adaptation face à l'élargissement du recrutement des élèves et à la diversification des filières. L'ancrage disciplinaire, l'exigence des contenus et le rapport aux élèves fondent le sens donné à l'activité professionnelle esquissant les contours d'une nouvelle professionnalité enseignante.]]></description>
      <pubDate>Wed, 27 Jun 2018 16:10:02 +0000</pubDate>
      <link>https://hal.umontpellier.fr/hal-01715821</link>
      <guid>https://hal.umontpellier.fr/hal-01715821</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Yves Dutercq)</author>
      <dc:creator>Yves Dutercq</dc:creator>
      <content:encoded><![CDATA[Dans le cadre d'une recherche sur les disparités d'accès aux classes préparatoires aux grandes écoles, nous analysons la manière dont les enseignants investissent leur travail auprès des élèves et répondent de façon différenciée aux principes de justice et d'efficacité auxquels ils sont simultanément confrontés. Les résultats témoignent d'une adaptation face à l'élargissement du recrutement des élèves et à la diversification des filières. L'ancrage disciplinaire, l'exigence des contenus et le rapport aux élèves fondent le sens donné à l'activité professionnelle esquissant les contours d'une nouvelle professionnalité enseignante.]]></content:encoded>
    </item>
    <item>
      <title>[hal-01716638] Les enseignants débutants en lycées professionnels et le rapport au savoir de leurs élèves.</title>
      <description><![CDATA[[...]]]></description>
      <pubDate>Wed, 27 Jun 2018 16:10:02 +0000</pubDate>
      <link>https://hal.archives-ouvertes.fr/hal-01716638</link>
      <guid>https://hal.archives-ouvertes.fr/hal-01716638</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Thérèse Perez-Roux)</author>
      <dc:creator>Thérèse Perez-Roux</dc:creator>
      <content:encoded><![CDATA[[...]]]></content:encoded>
    </item>
    <item>
      <title>[hal-01716660] Des dispositifs d'analyse de pratiques aux recherches collaboratives : quelle dynamique de déplacement des professionnels ?</title>
      <description><![CDATA[[...]]]></description>
      <pubDate>Wed, 27 Jun 2018 16:10:02 +0000</pubDate>
      <link>https://hal.archives-ouvertes.fr/hal-01716660</link>
      <guid>https://hal.archives-ouvertes.fr/hal-01716660</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Thérèse Perez-Roux)</author>
      <dc:creator>Thérèse Perez-Roux</dc:creator>
      <content:encoded><![CDATA[[...]]]></content:encoded>
    </item>
    <item>
      <title>[hal-01715702] Entrée dans le métier des enseignants et transition professionnelle : impact des contextes de professionnalisation et dynamiques d'acteurs</title>
      <description><![CDATA[À partir d'une entrée sociologique portant sur les processus de professionnalisation dans la formation des enseignants en France, l'article s'attache à comprendre les transitions professionnelles liées à l'entrée dans le métier des enseignants débutants. Il s'intéresse à la phase d'insertion professionnelle et aux modes d'ajustement vis-à-vis de soi-même, des autres acteurs, contextes locaux et plus largement de l'institution. Deux enquêtes par entretiens compréhensifs semi-directifs sont mobilisées : la première, réalisée avant la réforme de la formation de 2010 (28 néo-titulaires), la seconde en 2013 (12 fonctionnaires stagiaires). Les résultats montrent l'importance des contextes de professionnalisation et mettent en avant les positionnements et les stratégies des acteurs pour s'adapter à un métier complexe et exigeant.]]></description>
      <pubDate>Wed, 27 Jun 2018 16:10:02 +0000</pubDate>
      <link>https://hal.umontpellier.fr/hal-01715702</link>
      <guid>https://hal.umontpellier.fr/hal-01715702</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (XaviÈre LanÉelle)</author>
      <dc:creator>XaviÈre LanÉelle</dc:creator>
      <content:encoded><![CDATA[À partir d'une entrée sociologique portant sur les processus de professionnalisation dans la formation des enseignants en France, l'article s'attache à comprendre les transitions professionnelles liées à l'entrée dans le métier des enseignants débutants. Il s'intéresse à la phase d'insertion professionnelle et aux modes d'ajustement vis-à-vis de soi-même, des autres acteurs, contextes locaux et plus largement de l'institution. Deux enquêtes par entretiens compréhensifs semi-directifs sont mobilisées : la première, réalisée avant la réforme de la formation de 2010 (28 néo-titulaires), la seconde en 2013 (12 fonctionnaires stagiaires). Les résultats montrent l'importance des contextes de professionnalisation et mettent en avant les positionnements et les stratégies des acteurs pour s'adapter à un métier complexe et exigeant.]]></content:encoded>
    </item>
    <item>
      <title>[hal-01715806] Entrer dans le métier sans formation professionnelle : quels processus identitaires pour les enseignants du secondaire ?</title>
      <description><![CDATA[Les néo-enseignants du second degré ont été nommés à la rentrée 2010 sans formation professionnelle préalable. Les enquêtés, aux prises avec des contextes variés, évoquent une « crise de temps » pour s'approprier les injonctions institutionnelles, faire face aux classes, s'intégrer dans un établissement et se former. Les obstacles qui jalonnent les parcours interrogent le continuum entre formation initiale et formation continue. Ils mettent en évidence d'éventuels leviers pouvant faciliter la construction d'une professionnalité enseignante et l'émergence d'une identité professionnelle.]]></description>
      <pubDate>Wed, 27 Jun 2018 16:10:02 +0000</pubDate>
      <link>https://hal.umontpellier.fr/hal-01715806</link>
      <guid>https://hal.umontpellier.fr/hal-01715806</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Thérèse Perez-Roux)</author>
      <dc:creator>Thérèse Perez-Roux</dc:creator>
      <content:encoded><![CDATA[Les néo-enseignants du second degré ont été nommés à la rentrée 2010 sans formation professionnelle préalable. Les enquêtés, aux prises avec des contextes variés, évoquent une « crise de temps » pour s'approprier les injonctions institutionnelles, faire face aux classes, s'intégrer dans un établissement et se former. Les obstacles qui jalonnent les parcours interrogent le continuum entre formation initiale et formation continue. Ils mettent en évidence d'éventuels leviers pouvant faciliter la construction d'une professionnalité enseignante et l'émergence d'une identité professionnelle.]]></content:encoded>
    </item>
    <item>
      <title>[hal-01715812] LA INSERCIÓN PROFESIONAL DE LOS DOCENTES EN FRANCIA: PREOCUPACIONES DOMINANTES Y TRANSFORMACIONES IDENTITARIAS</title>
      <description><![CDATA[Apoyándose sobre otras investigaciones llevadas a cabo en España o en América del Sur, el estudio trata de las principales preocupaciones de los profesores principiantes en Francia, durante la fase de inserción profesional. Señala la problemática y las formas de adaptación a las nuevas condiciones de trabajo. La recopilación de datos abarca 28 entrevistas con profesores de primaria y secundaria. El análisis del corpus pone de manifiesto cuatro universos de significado que organizan la relación con la profesión de estos docentes. Los resultados destacan una serie de habilidades a confirmar o a (re)construir y ponen de manifiesto de la formación inicial. Muestran la heterogeneidad de las formas de socialización profesional y su impacto en el proceso de construcción de la identidad profesional de los docentes]]></description>
      <pubDate>Wed, 27 Jun 2018 16:10:02 +0000</pubDate>
      <link>https://hal.umontpellier.fr/hal-01715812</link>
      <guid>https://hal.umontpellier.fr/hal-01715812</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Thérèse Perez-Roux)</author>
      <dc:creator>Thérèse Perez-Roux</dc:creator>
      <content:encoded><![CDATA[Apoyándose sobre otras investigaciones llevadas a cabo en España o en América del Sur, el estudio trata de las principales preocupaciones de los profesores principiantes en Francia, durante la fase de inserción profesional. Señala la problemática y las formas de adaptación a las nuevas condiciones de trabajo. La recopilación de datos abarca 28 entrevistas con profesores de primaria y secundaria. El análisis del corpus pone de manifiesto cuatro universos de significado que organizan la relación con la profesión de estos docentes. Los resultados destacan una serie de habilidades a confirmar o a (re)construir y ponen de manifiesto de la formación inicial. Muestran la heterogeneidad de las formas de socialización profesional y su impacto en el proceso de construcción de la identidad profesional de los docentes]]></content:encoded>
    </item>
    <item>
      <title>[hal-01715816] Mutations institutionnelles et remaniements identitaires : enseignants et formateurs face aux réformes</title>
      <description><![CDATA[[...]]]></description>
      <pubDate>Wed, 27 Jun 2018 16:10:02 +0000</pubDate>
      <link>https://hal.umontpellier.fr/hal-01715816</link>
      <guid>https://hal.umontpellier.fr/hal-01715816</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Thérèse Perez-Roux)</author>
      <dc:creator>Thérèse Perez-Roux</dc:creator>
      <content:encoded><![CDATA[[...]]]></content:encoded>
    </item>
    <item>
      <title>[hal-01518479] Pluralité des ressources pour l’action dans les processus de transition formation-emploi chez les enseignants du secondaire</title>
      <description><![CDATA[La recherche s’inscrit dans une perspective sociologique à visée compréhensive. Elle s’intéresse aux processus de construction de la professionnalité enseignante, aux dynamiques d’insertion professionnelle et aux ressources plurielles mobilisées par les néo-enseignants du secondaire. La méthodologie de l’enquête est double : quantitative avec un questionnaire mis en ligne entre février et avril 2013 (n=160), qualitative avec 12 entretiens semi-directifs conduits avec des fonctionnaires-stagiaires de différentes disciplines. Les résultats mettent en lumière un système de ressources mobilisant normes institutionnelles relayées par la formation initiale et continue, cultures professionnelles plus ou moins partagées et formes de soutien dans lesquelles le rapport au tuteur prend une place essentielle. On constate que « l’idéal du métier » sert à orienter l’activité. Les élèves, bien que parfois déroutants, constituent aussi une ressource essentielle.]]></description>
      <pubDate>Wed, 27 Jun 2018 16:10:02 +0000</pubDate>
      <link>https://hal.archives-ouvertes.fr/hal-01518479</link>
      <guid>https://hal.archives-ouvertes.fr/hal-01518479</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Thérèse Perez-Roux)</author>
      <dc:creator>Thérèse Perez-Roux</dc:creator>
      <content:encoded><![CDATA[La recherche s’inscrit dans une perspective sociologique à visée compréhensive. Elle s’intéresse aux processus de construction de la professionnalité enseignante, aux dynamiques d’insertion professionnelle et aux ressources plurielles mobilisées par les néo-enseignants du secondaire. La méthodologie de l’enquête est double : quantitative avec un questionnaire mis en ligne entre février et avril 2013 (n=160), qualitative avec 12 entretiens semi-directifs conduits avec des fonctionnaires-stagiaires de différentes disciplines. Les résultats mettent en lumière un système de ressources mobilisant normes institutionnelles relayées par la formation initiale et continue, cultures professionnelles plus ou moins partagées et formes de soutien dans lesquelles le rapport au tuteur prend une place essentielle. On constate que « l’idéal du métier » sert à orienter l’activité. Les élèves, bien que parfois déroutants, constituent aussi une ressource essentielle.]]></content:encoded>
    </item>
    <item>
      <title>[hal-01215916] L’accompagnement des enseignants à l’heure des réformes : stratégies des formateurs de terrain face à de nouvelles formes de (dé)professionnalisation</title>
      <description><![CDATA[En France, la « masterisation » de la formation des enseignants (2010) a modifié la place et le rôle des formateurs de terrain. L’étude s’intéresse à la manière dont certains d’entre eux (Professeurs des Écoles Maîtres Formateurs) ont vécu la mise en oeuvre de cette réforme. Elle cherche à montrer les compromis et arrangements déployés par les acteurs pour faire face à ces changements. Les données d’une enquête par questionnaire ont initié ce travail. Des entretiens ont été conduits avec 9 PEMF. Les résultats montrent un sentiment dominant de déprofessionnalisation chez les acteurs. On repère à la fois un mouvement de résistance au sein du groupe et des stratégies individuelles en continuité ou en rupture avec les modèles de professionnalisation antérieurs. Au-delà de ces transformations, l’étude interroge les effets de l’universitarisation de la formation.]]></description>
      <pubDate>Wed, 27 Jun 2018 16:10:01 +0000</pubDate>
      <link>https://hal.archives-ouvertes.fr/hal-01215916</link>
      <guid>https://hal.archives-ouvertes.fr/hal-01215916</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Thérèse Perez-Roux)</author>
      <dc:creator>Thérèse Perez-Roux</dc:creator>
      <content:encoded><![CDATA[En France, la « masterisation » de la formation des enseignants (2010) a modifié la place et le rôle des formateurs de terrain. L’étude s’intéresse à la manière dont certains d’entre eux (Professeurs des Écoles Maîtres Formateurs) ont vécu la mise en oeuvre de cette réforme. Elle cherche à montrer les compromis et arrangements déployés par les acteurs pour faire face à ces changements. Les données d’une enquête par questionnaire ont initié ce travail. Des entretiens ont été conduits avec 9 PEMF. Les résultats montrent un sentiment dominant de déprofessionnalisation chez les acteurs. On repère à la fois un mouvement de résistance au sein du groupe et des stratégies individuelles en continuité ou en rupture avec les modèles de professionnalisation antérieurs. Au-delà de ces transformations, l’étude interroge les effets de l’universitarisation de la formation.]]></content:encoded>
    </item>
    <item>
      <title>[hal-00998494] Integration of Social Media in Recruitment: A Delphi Study</title>
      <description><![CDATA[Purpose -- The development of social media provides new opportunities for recruitment and raises various questions. This chapter aims to clarify areas of agreement and disagreement regarding the integration of social media in recruitment strategies. Methodology/approach -- A Delphi study was conducted among a panel of 34 French experts composed of 26 practitioners and 8 academics. Findings -- Three quantitative results and five qualitative results are presented. Social media appear as an opportunity to raise the strategic role of HR professionals through employer branding strategy, internal skills development, and a greater involvement of managers within the sourcing process. Practical implications -- This study points out several barriers and limits regarding the integration of social media in recruitment strategies and encourage HR professionals to take up the challenge. Multiple recommendations are addressed to HR professionals. Originality/value of chapter -- This chapter is based on an innovative application of the Delphi method. Moreover, it offers a more comprehensive and critical look on the integration of social media in recruitment strategies.]]></description>
      <pubDate>Wed, 27 Jun 2018 16:08:01 +0000</pubDate>
      <link>https://hal.archives-ouvertes.fr/hal-00998494</link>
      <guid>https://hal.archives-ouvertes.fr/hal-00998494</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Aurélie Girard)</author>
      <dc:creator>Aurélie Girard</dc:creator>
      <content:encoded><![CDATA[Purpose -- The development of social media provides new opportunities for recruitment and raises various questions. This chapter aims to clarify areas of agreement and disagreement regarding the integration of social media in recruitment strategies. Methodology/approach -- A Delphi study was conducted among a panel of 34 French experts composed of 26 practitioners and 8 academics. Findings -- Three quantitative results and five qualitative results are presented. Social media appear as an opportunity to raise the strategic role of HR professionals through employer branding strategy, internal skills development, and a greater involvement of managers within the sourcing process. Practical implications -- This study points out several barriers and limits regarding the integration of social media in recruitment strategies and encourage HR professionals to take up the challenge. Multiple recommendations are addressed to HR professionals. Originality/value of chapter -- This chapter is based on an innovative application of the Delphi method. Moreover, it offers a more comprehensive and critical look on the integration of social media in recruitment strategies.]]></content:encoded>
    </item>
    <item>
      <title>[cel-00343873] Paramètres S - Antennes</title>
      <description><![CDATA[[...]]]></description>
      <pubDate>Wed, 27 Jun 2018 16:07:32 +0000</pubDate>
      <link>https://cel.archives-ouvertes.fr/cel-00343873</link>
      <guid>https://cel.archives-ouvertes.fr/cel-00343873</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Laurent Chusseau)</author>
      <dc:creator>Laurent Chusseau</dc:creator>
      <content:encoded><![CDATA[[...]]]></content:encoded>
    </item>
    <item>
      <title>[hal-01185766] A Natural Resource-Systems approach: Targeting the Ecological Transition at the Regional Scale</title>
      <description><![CDATA[Human history can be mirrored in a geo-history of natural resources. Humans, by over-exploiting resources (“forcing”), have produced extensive land use changes and have altered complex food webs, ecosystems, and habitats with as a consequence systematic natural biocapacity erosion, biodiversity loss, energy crises, pollution, climate deregulation. In other terms, a global resources “rush” has led to chronic socio-ecosystemic deficits, thus creating the conditions for local and global state shifts within the biosphere and / or society. Therefore, research must serve to increase human understanding of those resources and how best to use them for the public good.]]></description>
      <pubDate>Wed, 27 Jun 2018 16:02:01 +0000</pubDate>
      <link>https://hal.archives-ouvertes.fr/hal-01185766</link>
      <guid>https://hal.archives-ouvertes.fr/hal-01185766</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Jean-Louis Weber)</author>
      <dc:creator>Jean-Louis Weber</dc:creator>
      <content:encoded><![CDATA[Human history can be mirrored in a geo-history of natural resources. Humans, by over-exploiting resources (“forcing”), have produced extensive land use changes and have altered complex food webs, ecosystems, and habitats with as a consequence systematic natural biocapacity erosion, biodiversity loss, energy crises, pollution, climate deregulation. In other terms, a global resources “rush” has led to chronic socio-ecosystemic deficits, thus creating the conditions for local and global state shifts within the biosphere and / or society. Therefore, research must serve to increase human understanding of those resources and how best to use them for the public good.]]></content:encoded>
    </item>
    <item>
      <title>[hal-01084564] Les Ressources – le grand enjeu de la transition sociétale et écologique</title>
      <description><![CDATA[A travers la problématique des ressources, ce travail questionne la finalité des activités économiques et des modes de production. Il propose une démarche socio-environnementale intégrée et pluri-disciplinaire pour, à travers les droits et les devoirs de l’homme, préserver les fonctions et les services écosystémiques, satisfaire aux besoins vitaux des humains et construire un projet culturel et politique cohérent reliant, pour l’ensemble des secteurs d’activité et pour l’ensemble de la société, l’alimentation, la santé, l’environnement, l’éducation/la culture. Ces conditions étant posées, deux aspects sont approfondies : identifier des concepts et des outils nécessaires pour répondre à ces trois contraintes et, sur cette base, définir comment construire des programmes de recherche multi-acteurs pour analyser et quantifier les changements attendus au niveau territorial.]]></description>
      <pubDate>Wed, 27 Jun 2018 16:02:01 +0000</pubDate>
      <link>https://hal.archives-ouvertes.fr/hal-01084564</link>
      <guid>https://hal.archives-ouvertes.fr/hal-01084564</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Ioan Negrutiu)</author>
      <dc:creator>Ioan Negrutiu</dc:creator>
      <content:encoded><![CDATA[A travers la problématique des ressources, ce travail questionne la finalité des activités économiques et des modes de production. Il propose une démarche socio-environnementale intégrée et pluri-disciplinaire pour, à travers les droits et les devoirs de l’homme, préserver les fonctions et les services écosystémiques, satisfaire aux besoins vitaux des humains et construire un projet culturel et politique cohérent reliant, pour l’ensemble des secteurs d’activité et pour l’ensemble de la société, l’alimentation, la santé, l’environnement, l’éducation/la culture. Ces conditions étant posées, deux aspects sont approfondies : identifier des concepts et des outils nécessaires pour répondre à ces trois contraintes et, sur cette base, définir comment construire des programmes de recherche multi-acteurs pour analyser et quantifier les changements attendus au niveau territorial.]]></content:encoded>
    </item>
    <item>
      <title>[hal-01824390] Transmural stretch-dependent regulation of contractile properties in rat heart and its alteration after myocardial infarction</title>
      <description><![CDATA[The &quot; stretch-sensitization &quot; response is essential to the regulation of heart contractility. An increase in diastolic volume improves systolic contraction. The cellular mechanisms of this modulation, the Frank-Starling law, are still uncertain. Moreover, their alterations in heart failure remains controversial. Here, using left ventricular skinned rat myocytes, we show a nonuniform stretch-sensitization of myofilament activation across the ventricular wall. Stretch-dependent Ca 2+ sensitization of myofilaments increases from sub-epicardium to sub-endocardium and is correlated with an increase in passive tension. This passive tension-dependent component of myofibrillar activation is not associated with expression of titin isoforms, changes in troponin I level, and phosphorylation status. Instead, we observe that stretch induces phosphorylation of ventricular myosin light chain 2 isoform (VLC2b) in sub-endocardium specifically. Thus, VLC2b phosphorylation could act as a stretch-dependent modulator of activation tuned within normal heart. Moreover, in postmyocardial infarcted rat, the gradient of stretch-dependent Ca 2+ sensitization disappears associated with a lack of VLC2b phosphorylation in sub-endocardium. In conclusion, nonuniformity is a major characteristic of the normal adult left ventricle (LV). The heterogeneous myocardial deformation pattern might be caused not only by the morphological heterogeneity of the tissue in the LV wall, but also by the nonuniform contractile properties of the myocytes across the wall. The loss of a contractile transmural gradient after myocardial infarction should contribute to the impaired LV function. Key words: Ca 2+ sensitization • Frank-Starling law • ventricular myocytes • myosin light chain 2 • heart failure eart muscle has the property to develop positive inotropism in response to an increase in end-diastolic ventricular volume. This phenomenon, known as the Frank-Starling law, originates from cell adaptation to stretch involving a sarcomere length (SL) dependence of the Ca 2+ sensitivity of myofilament activation (1). The mechanisms that underlie this intrinsic property may involve a length-dependent increase in the affinity of the regulatory site of troponin H]]></description>
      <pubDate>Wed, 27 Jun 2018 15:59:38 +0000</pubDate>
      <link>https://hal.umontpellier.fr/hal-01824390</link>
      <guid>https://hal.umontpellier.fr/hal-01824390</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Olivier Cazorla)</author>
      <dc:creator>Olivier Cazorla</dc:creator>
      <content:encoded><![CDATA[The &quot; stretch-sensitization &quot; response is essential to the regulation of heart contractility. An increase in diastolic volume improves systolic contraction. The cellular mechanisms of this modulation, the Frank-Starling law, are still uncertain. Moreover, their alterations in heart failure remains controversial. Here, using left ventricular skinned rat myocytes, we show a nonuniform stretch-sensitization of myofilament activation across the ventricular wall. Stretch-dependent Ca 2+ sensitization of myofilaments increases from sub-epicardium to sub-endocardium and is correlated with an increase in passive tension. This passive tension-dependent component of myofibrillar activation is not associated with expression of titin isoforms, changes in troponin I level, and phosphorylation status. Instead, we observe that stretch induces phosphorylation of ventricular myosin light chain 2 isoform (VLC2b) in sub-endocardium specifically. Thus, VLC2b phosphorylation could act as a stretch-dependent modulator of activation tuned within normal heart. Moreover, in postmyocardial infarcted rat, the gradient of stretch-dependent Ca 2+ sensitization disappears associated with a lack of VLC2b phosphorylation in sub-endocardium. In conclusion, nonuniformity is a major characteristic of the normal adult left ventricle (LV). The heterogeneous myocardial deformation pattern might be caused not only by the morphological heterogeneity of the tissue in the LV wall, but also by the nonuniform contractile properties of the myocytes across the wall. The loss of a contractile transmural gradient after myocardial infarction should contribute to the impaired LV function. Key words: Ca 2+ sensitization • Frank-Starling law • ventricular myocytes • myosin light chain 2 • heart failure eart muscle has the property to develop positive inotropism in response to an increase in end-diastolic ventricular volume. This phenomenon, known as the Frank-Starling law, originates from cell adaptation to stretch involving a sarcomere length (SL) dependence of the Ca 2+ sensitivity of myofilament activation (1). The mechanisms that underlie this intrinsic property may involve a length-dependent increase in the affinity of the regulatory site of troponin H]]></content:encoded>
    </item>
    <item>
      <title>[hal-01824386] Effects of high-altitude exercise training on contractile function of rat skinned cardiomyocyte</title>
      <description><![CDATA[Objective: Previous studies have questioned whether there is an improved cardiac function after high-altitude training. Accordingly, the present study was designed specifically to test whether this apparent blunted response of the whole heart to training can be accounted for by altered mechanical properties at the cellular level. Methods: Adult rats were trained for 5 weeks under normoxic (N, NT for sedentary and trained animals, respectively) or hypobaric hypoxic (H, HT) conditions. Cardiac morphology and function were evaluated by echocardiography. Calcium Ca 2+ sensitivity of the contractile machinery was estimated in skinned cardiomyocytes isolated from the left ventricular (LV) sub-epicardium (Epi) and sub-endocardium (Endo) at short and long sarcomere lengths (SL). Results: Cardiac remodelling was harmonious (increase in wall thickness with chamber dilatation) in NT rats and disharmonious (hypertrophy without chamber dilatation) in HT rats. Contrary to NT rats, HT rats did not exhibit enhancement in global cardiac performance evaluated by echocardiography. Stretch-dependent Ca 2+ sensitization of the myofilaments (cellular index of the Frank-Starling mechanism) increased from Epi to Endo in N rats. Training in normoxic conditions further increased this stretch-dependent Ca 2+ sensitization. Chronic hypoxia did not significantly affect myofibrilar Ca 2+ sensitivity. In contrast, high-altitude training decreased Ca 2+ sensitivity of the myofilaments at both SL, mostly in Endo cells, resulting in a loss of the transmural gradient of the stretch-dependent Ca 2+ sensitization. Expression of myosin heavy chain isoforms was affected both by training and chronic hypoxia but did not correlate with mechanical data. Conclusions: Training at sea level increased the transmural gradient of stretch-dependent Ca 2+ sensitization of the myofilaments, accounting for an improved Frank-Starling mechanism. High-altitude training depressed myofilament response to Ca 2+ , especially in the Endo layer. This led to a reduction in this transmural gradient that may contribute to the lack of improvement in LV function via the Frank-Starling mechanism.]]></description>
      <pubDate>Wed, 27 Jun 2018 15:54:18 +0000</pubDate>
      <link>https://hal.umontpellier.fr/hal-01824386</link>
      <guid>https://hal.umontpellier.fr/hal-01824386</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Olivier Cazorla)</author>
      <dc:creator>Olivier Cazorla</dc:creator>
      <content:encoded><![CDATA[Objective: Previous studies have questioned whether there is an improved cardiac function after high-altitude training. Accordingly, the present study was designed specifically to test whether this apparent blunted response of the whole heart to training can be accounted for by altered mechanical properties at the cellular level. Methods: Adult rats were trained for 5 weeks under normoxic (N, NT for sedentary and trained animals, respectively) or hypobaric hypoxic (H, HT) conditions. Cardiac morphology and function were evaluated by echocardiography. Calcium Ca 2+ sensitivity of the contractile machinery was estimated in skinned cardiomyocytes isolated from the left ventricular (LV) sub-epicardium (Epi) and sub-endocardium (Endo) at short and long sarcomere lengths (SL). Results: Cardiac remodelling was harmonious (increase in wall thickness with chamber dilatation) in NT rats and disharmonious (hypertrophy without chamber dilatation) in HT rats. Contrary to NT rats, HT rats did not exhibit enhancement in global cardiac performance evaluated by echocardiography. Stretch-dependent Ca 2+ sensitization of the myofilaments (cellular index of the Frank-Starling mechanism) increased from Epi to Endo in N rats. Training in normoxic conditions further increased this stretch-dependent Ca 2+ sensitization. Chronic hypoxia did not significantly affect myofibrilar Ca 2+ sensitivity. In contrast, high-altitude training decreased Ca 2+ sensitivity of the myofilaments at both SL, mostly in Endo cells, resulting in a loss of the transmural gradient of the stretch-dependent Ca 2+ sensitization. Expression of myosin heavy chain isoforms was affected both by training and chronic hypoxia but did not correlate with mechanical data. Conclusions: Training at sea level increased the transmural gradient of stretch-dependent Ca 2+ sensitization of the myofilaments, accounting for an improved Frank-Starling mechanism. High-altitude training depressed myofilament response to Ca 2+ , especially in the Endo layer. This led to a reduction in this transmural gradient that may contribute to the lack of improvement in LV function via the Frank-Starling mechanism.]]></content:encoded>
    </item>
    <item>
      <title>[hal-01824393] SR33805, a Ca 2+ antagonist with length-dependent Ca 2+ -sensitizing properties in cardiac myocytes</title>
      <description><![CDATA[This study examined the effects of SR33805, a fantofarone derivative with reported strong Ca2+ ‐antagonistic properties, on the contractile properties of intact and skinned rat ventricular myocytes. On intact cells loaded with the Ca2+‐fluorescent indicator Indo‐1, the application of low concentrations of SR33805 enhanced the amplitude of unloaded cell shortening and decreased the duration of cell shortening. Amplitude of the Ca2+ transient was also decreased. These effects were accompanied with a shortening of the action potential and a dose‐dependent blockade of L‐type calcium current (IC50=2.4 × 10−8 M). On skinned cardiac cells, the application of a low SR33805 concentration (10−8 M) induced a significant increase in maximal Ca2+‐activated force at the two‐tested sarcomere lengths (SLs), 1.9 and 2.3 μm. The application of a larger dose of SR33805 (10−6–10−5 M) induced a significant leftward shift of the tension–pCa relation that accounts for Ca2+‐sensitization of the myofilaments, particularly at 2.3 μm SL. In conclusion, despite its strong Ca2+‐antagonistic properties SR33805 increases cardiac cell contractile activity as a consequence of its Ca2+‐sensitizing effects. These effects are attributable to both an increase in the maximal Ca2+‐activated force and a length‐dependent Ca2+‐sensitization.]]></description>
      <pubDate>Wed, 27 Jun 2018 15:48:27 +0000</pubDate>
      <link>https://hal.umontpellier.fr/hal-01824393</link>
      <guid>https://hal.umontpellier.fr/hal-01824393</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Olivier Cazorla)</author>
      <dc:creator>Olivier Cazorla</dc:creator>
      <content:encoded><![CDATA[This study examined the effects of SR33805, a fantofarone derivative with reported strong Ca2+ ‐antagonistic properties, on the contractile properties of intact and skinned rat ventricular myocytes. On intact cells loaded with the Ca2+‐fluorescent indicator Indo‐1, the application of low concentrations of SR33805 enhanced the amplitude of unloaded cell shortening and decreased the duration of cell shortening. Amplitude of the Ca2+ transient was also decreased. These effects were accompanied with a shortening of the action potential and a dose‐dependent blockade of L‐type calcium current (IC50=2.4 × 10−8 M). On skinned cardiac cells, the application of a low SR33805 concentration (10−8 M) induced a significant increase in maximal Ca2+‐activated force at the two‐tested sarcomere lengths (SLs), 1.9 and 2.3 μm. The application of a larger dose of SR33805 (10−6–10−5 M) induced a significant leftward shift of the tension–pCa relation that accounts for Ca2+‐sensitization of the myofilaments, particularly at 2.3 μm SL. In conclusion, despite its strong Ca2+‐antagonistic properties SR33805 increases cardiac cell contractile activity as a consequence of its Ca2+‐sensitizing effects. These effects are attributable to both an increase in the maximal Ca2+‐activated force and a length‐dependent Ca2+‐sensitization.]]></content:encoded>
    </item>
    <item>
      <title>[tel-01760012] The KISS principle applied to the conception of sensors and to the bibliographic survey</title>
      <description><![CDATA[In this thesis, we report that a &quot;tree-like&quot; dendrigraft ofpoly-L-Lysine (DGL) is able to form a multi-ligand complex with afluorescently labelled peptide, leading to the almost complete extinction ofthe optical signal that can be restored upon the introduction of heparin. This simple system allows, for the first time, the turn-ON fluorescent sensing of the anticoagulant in human blood at clinically relevant levels. Then, we demonstrate that this sensing ensemble can evolve toward a sensorarray. Depending on the loading of the indicator on the receptor, negatively charged glycosaminoglycans (GAGs) induce a positive or negative variation of the fluorescent signal as they displace the indicators from the receptor or they compact the indicators on the receptor’s surface, respectively. This unique strategy allows not only the blind identification of pure GAGs with a level of accuracy of 100 %, but also the differentiation of mixtures.We also report an original and simple methodology for the construction of three-dimensional structures of DGLs, and the subsequent investigation of their structural features using molecular dynamics simulations. This methodology relies on the encoding of the polymers’ experimental characterizations (i.e. degrees of polymerization, branchingratios, charges) into alphanumeric strings that are &quot;readable&quot; by the Ambersimulation package. This work opens avenues toward the in silico exploration of dendrigrafts and hyperbranched polymers.Finally, we developed ChemBrows, an in-house software that will significantly help scientists/teachers/ students to tame the flood of publications.Working as an enhanced RSS reader that integrates keyword-based filters anda machine-learning-based recommendation engine, ChemBrows is available onmultiple platforms as a free and open-source software at www.chembrows.com.]]></description>
      <pubDate>Wed, 27 Jun 2018 15:39:05 +0000</pubDate>
      <link>https://tel.archives-ouvertes.fr/tel-01760012</link>
      <guid>https://tel.archives-ouvertes.fr/tel-01760012</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Jean-Patrick Francoïa)</author>
      <dc:creator>Jean-Patrick Francoïa</dc:creator>
      <content:encoded><![CDATA[In this thesis, we report that a &quot;tree-like&quot; dendrigraft ofpoly-L-Lysine (DGL) is able to form a multi-ligand complex with afluorescently labelled peptide, leading to the almost complete extinction ofthe optical signal that can be restored upon the introduction of heparin. This simple system allows, for the first time, the turn-ON fluorescent sensing of the anticoagulant in human blood at clinically relevant levels. Then, we demonstrate that this sensing ensemble can evolve toward a sensorarray. Depending on the loading of the indicator on the receptor, negatively charged glycosaminoglycans (GAGs) induce a positive or negative variation of the fluorescent signal as they displace the indicators from the receptor or they compact the indicators on the receptor’s surface, respectively. This unique strategy allows not only the blind identification of pure GAGs with a level of accuracy of 100 %, but also the differentiation of mixtures.We also report an original and simple methodology for the construction of three-dimensional structures of DGLs, and the subsequent investigation of their structural features using molecular dynamics simulations. This methodology relies on the encoding of the polymers’ experimental characterizations (i.e. degrees of polymerization, branchingratios, charges) into alphanumeric strings that are &quot;readable&quot; by the Ambersimulation package. This work opens avenues toward the in silico exploration of dendrigrafts and hyperbranched polymers.Finally, we developed ChemBrows, an in-house software that will significantly help scientists/teachers/ students to tame the flood of publications.Working as an enhanced RSS reader that integrates keyword-based filters anda machine-learning-based recommendation engine, ChemBrows is available onmultiple platforms as a free and open-source software at www.chembrows.com.]]></content:encoded>
    </item>
    <item>
      <title>[hal-01821977] Linking genomics and population genetics with R</title>
      <description><![CDATA[[...]]]></description>
      <pubDate>Wed, 27 Jun 2018 15:31:36 +0000</pubDate>
      <link>https://hal.umontpellier.fr/hal-01821977</link>
      <guid>https://hal.umontpellier.fr/hal-01821977</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Emmanuel Paradis)</author>
      <dc:creator>Emmanuel Paradis</dc:creator>
      <content:encoded><![CDATA[[...]]]></content:encoded>
    </item>
    <item>
      <title>[hal-01821952] The distribution of branch lengths in phylogenetic trees</title>
      <description><![CDATA[A lot of effort has been devoted to analyse the distribution of branching times observed in a phylogenetic tree. On the other hand, the distribution of branch lengths has not received similar attention. In this paper, the distribution of branch lengths is studied. It is shown that different types of branches within a tree have distinct distributions. Some equations to predict these distributions are derived with respect to diversification parameters and whether the size of the tree is known or not. A simulation study validated these predictions. The inferred distributions are used to develop graphical and statistical tools to assess the goodness-of-fit of diversification models. An application is presented on a recently published dated phylogeny of Carnivora. Some future developments are discussed.]]></description>
      <pubDate>Wed, 27 Jun 2018 15:29:48 +0000</pubDate>
      <link>https://hal.umontpellier.fr/hal-01821952</link>
      <guid>https://hal.umontpellier.fr/hal-01821952</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Emmanuel Paradis)</author>
      <dc:creator>Emmanuel Paradis</dc:creator>
      <content:encoded><![CDATA[A lot of effort has been devoted to analyse the distribution of branching times observed in a phylogenetic tree. On the other hand, the distribution of branch lengths has not received similar attention. In this paper, the distribution of branch lengths is studied. It is shown that different types of branches within a tree have distinct distributions. Some equations to predict these distributions are derived with respect to diversification parameters and whether the size of the tree is known or not. A simulation study validated these predictions. The inferred distributions are used to develop graphical and statistical tools to assess the goodness-of-fit of diversification models. An application is presented on a recently published dated phylogeny of Carnivora. Some future developments are discussed.]]></content:encoded>
    </item>
    <item>
      <title>[hal-01821944] Random phylogenies and the distribution of branching times</title>
      <description><![CDATA[Phylogenetic trees reconstructed without fossils have become an important source of information to study evolutionary processes. A widely used method to describe patterns of phylogenetic diversification is known as the lineages-through-time (LTT) plot. Recently, it has been shown that it is possible to predict the distribution of the branching times of a phylogeny, thus making possible to derive a theoretical LTT curve conditioned on diversification parameters. Here, I review some aspects related to this prediction showing how to derive it for any time-dependent model of diversification, as well as calculating a prediction interval around a theoretical LTT curve. The accuracy of the prediction interval was assessed with simulations using fixed or random tree sizes under constant-rate models as well as two models of time-dependent diversification. The prediction intervals were relatively narrower and more accurate for larger trees. The features of this approach are discussed as well as its potential applications.]]></description>
      <pubDate>Wed, 27 Jun 2018 15:28:12 +0000</pubDate>
      <link>https://hal.umontpellier.fr/hal-01821944</link>
      <guid>https://hal.umontpellier.fr/hal-01821944</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Emmanuel Paradis)</author>
      <dc:creator>Emmanuel Paradis</dc:creator>
      <content:encoded><![CDATA[Phylogenetic trees reconstructed without fossils have become an important source of information to study evolutionary processes. A widely used method to describe patterns of phylogenetic diversification is known as the lineages-through-time (LTT) plot. Recently, it has been shown that it is possible to predict the distribution of the branching times of a phylogeny, thus making possible to derive a theoretical LTT curve conditioned on diversification parameters. Here, I review some aspects related to this prediction showing how to derive it for any time-dependent model of diversification, as well as calculating a prediction interval around a theoretical LTT curve. The accuracy of the prediction interval was assessed with simulations using fixed or random tree sizes under constant-rate models as well as two models of time-dependent diversification. The prediction intervals were relatively narrower and more accurate for larger trees. The features of this approach are discussed as well as its potential applications.]]></content:encoded>
    </item>
    <item>
      <title>[hal-01821922] Quantifying Variation in Speciation and Extinction Rates With Clade Data</title>
      <description><![CDATA[[...]]]></description>
      <pubDate>Wed, 27 Jun 2018 15:26:37 +0000</pubDate>
      <link>https://hal.umontpellier.fr/hal-01821922</link>
      <guid>https://hal.umontpellier.fr/hal-01821922</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Emmanuel Paradis)</author>
      <dc:creator>Emmanuel Paradis</dc:creator>
      <content:encoded><![CDATA[[...]]]></content:encoded>
    </item>
    <item>
      <title>[tel-01759805] Modelling study of vanadium based metal alloys and crystalline porous materials for gas separation membranes</title>
      <description><![CDATA[In this study, we propose procedures based on computational calculations and theoretical models that can be used to predict the behaviour of some of the membrane materials of interest for gas separation applications. In particular, we focus on: i) body-centred cubic VNiTi alloys as novel materials for H2-selective dense membranes and ii) crystalline porous materials that are attractive media for separation of light gases such as H2, O2, CO, CO2, CH4 and N2. These two types of materials are treated using different methodologies, adapted to the needs of our research objectives associated to each material.In the case of dense metal membranes, the long-standing controversy over occupancy of interstitial hydrogen in V-based alloys is addressed. The V-Ni-Ti system is of particular interest here, exhibiting high H2 permeability and improved mechanical properties relative to pure V. This work intends to gain understanding of hydrogen-metal interactions as function of alloy composition and thereby to optimize these new materials and advance their development as novel membranes for H2 separation. We use a first-principles approach that gives insights into the sites preference of hydrogen and assesses the role of Ti and Ni substitutional solutes for the hydrogen absorption affinity. The method based on Density Functional Theory requires no experimental input except crystal structure information. Furthermore, it uses no empirical or fitting parameters in contrast to other computational techniques. Hence this approach provides an alternative way to explore new metal alloys for H2 separation membranes. The applied methodology can be used further in high-throughput calculations to screen various alloy compositions. The hereto-reported results will be used as guidance for tailoring the formulation of VNiTi solid solutions and preparation of low cost dense alloy membranes in the frame of other projects (e.g. European DEMCAMER project).Further, we explore how single-component inputs can be used to forecast the ideal selectivity towards light gases of crystalline porous materials, used for membrane preparation. Theoretical models for describing gas separation properties of zeotype materials as function of structural characteristics and operation conditions are proposed. The model parameters can be obtained as experimentally as well as computationally. To analyse the extent of validity and limitations of the models, ideal selectivities of few crystalline porous materials are evaluated, including widely used zeolites (NaA, CaA) and a metal organic framework structure (ZIF-8). The results verified that the theoretical expressions could be used for screening series of zeotype materials when reliable single gas adsorption data are available. However, since the models don’t take into account all parameters (namely related to the membrane design) and mechanisms involved in gas transport through porous membranes, their predictions should be considered as values referring to an ideal case.]]></description>
      <pubDate>Wed, 27 Jun 2018 15:25:07 +0000</pubDate>
      <link>https://tel.archives-ouvertes.fr/tel-01759805</link>
      <guid>https://tel.archives-ouvertes.fr/tel-01759805</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Jenny Borisova Evtimova)</author>
      <dc:creator>Jenny Borisova Evtimova</dc:creator>
      <content:encoded><![CDATA[In this study, we propose procedures based on computational calculations and theoretical models that can be used to predict the behaviour of some of the membrane materials of interest for gas separation applications. In particular, we focus on: i) body-centred cubic VNiTi alloys as novel materials for H2-selective dense membranes and ii) crystalline porous materials that are attractive media for separation of light gases such as H2, O2, CO, CO2, CH4 and N2. These two types of materials are treated using different methodologies, adapted to the needs of our research objectives associated to each material.In the case of dense metal membranes, the long-standing controversy over occupancy of interstitial hydrogen in V-based alloys is addressed. The V-Ni-Ti system is of particular interest here, exhibiting high H2 permeability and improved mechanical properties relative to pure V. This work intends to gain understanding of hydrogen-metal interactions as function of alloy composition and thereby to optimize these new materials and advance their development as novel membranes for H2 separation. We use a first-principles approach that gives insights into the sites preference of hydrogen and assesses the role of Ti and Ni substitutional solutes for the hydrogen absorption affinity. The method based on Density Functional Theory requires no experimental input except crystal structure information. Furthermore, it uses no empirical or fitting parameters in contrast to other computational techniques. Hence this approach provides an alternative way to explore new metal alloys for H2 separation membranes. The applied methodology can be used further in high-throughput calculations to screen various alloy compositions. The hereto-reported results will be used as guidance for tailoring the formulation of VNiTi solid solutions and preparation of low cost dense alloy membranes in the frame of other projects (e.g. European DEMCAMER project).Further, we explore how single-component inputs can be used to forecast the ideal selectivity towards light gases of crystalline porous materials, used for membrane preparation. Theoretical models for describing gas separation properties of zeotype materials as function of structural characteristics and operation conditions are proposed. The model parameters can be obtained as experimentally as well as computationally. To analyse the extent of validity and limitations of the models, ideal selectivities of few crystalline porous materials are evaluated, including widely used zeolites (NaA, CaA) and a metal organic framework structure (ZIF-8). The results verified that the theoretical expressions could be used for screening series of zeotype materials when reliable single gas adsorption data are available. However, since the models don’t take into account all parameters (namely related to the membrane design) and mechanisms involved in gas transport through porous membranes, their predictions should be considered as values referring to an ideal case.]]></content:encoded>
    </item>
    <item>
      <title>[tel-01759632] Phosphates de type NASICON comme matériaux d'électrode pour batteries sodium-ion à haute densité d'énergie</title>
      <description><![CDATA[Ce mémoire est consacré à l’étude des composites à base de phosphates de type NASICON comme matériaux d’électrode pour batteries sodium-ion : Na1+xFexTi2-x(PO4)3/C et Na1+xFexSn2-x(PO4)3/C avec 0 ≤ x ≤ 1. Ces composites ont été synthétisés par voie solide suivie d’une pyrolyse avec le saccharose. Ils sont constitués de particules ayant une porosité élevée et enrobées par du carbone conférant à l’électrode une bonne conductivité ionique et électronique. Les mécanismes réactionnels se produisant lors des cycles de charge-décharge ont été analysés en mode operando par diffraction des rayons X, spectroscopies Mössbauer du 57Fe et de 119Sn et spectroscopie d’absorption X. Pour les composites fer-titane, ces mécanismes sont essentiellement basés sur la diffusion des ions Na+ dans les canaux des phases cristallisées avec changements d’état d’oxydation des métaux. Pour les composites fer-étain, les mécanismes sont plus complexes incluant insertion, conversion conduisant à la destruction des phases NASICON, puis formation d’alliages NaxSn. Les meilleures performances électrochimiques ont été obtenues pour Na1,5Fe0,5Ti1,5(PO4)3/C avec un potentiel de fonctionnement de 2,2 V vs Na+/Na0. Même si ces deux familles de matériaux peuvent être utilisées à plus bas potentiel, les performances doivent être améliorées pour envisager leur application comme électrode négative.]]></description>
      <pubDate>Wed, 27 Jun 2018 15:12:14 +0000</pubDate>
      <link>https://tel.archives-ouvertes.fr/tel-01759632</link>
      <guid>https://tel.archives-ouvertes.fr/tel-01759632</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Siham Difi)</author>
      <dc:creator>Siham Difi</dc:creator>
      <content:encoded><![CDATA[Ce mémoire est consacré à l’étude des composites à base de phosphates de type NASICON comme matériaux d’électrode pour batteries sodium-ion : Na1+xFexTi2-x(PO4)3/C et Na1+xFexSn2-x(PO4)3/C avec 0 ≤ x ≤ 1. Ces composites ont été synthétisés par voie solide suivie d’une pyrolyse avec le saccharose. Ils sont constitués de particules ayant une porosité élevée et enrobées par du carbone conférant à l’électrode une bonne conductivité ionique et électronique. Les mécanismes réactionnels se produisant lors des cycles de charge-décharge ont été analysés en mode operando par diffraction des rayons X, spectroscopies Mössbauer du 57Fe et de 119Sn et spectroscopie d’absorption X. Pour les composites fer-titane, ces mécanismes sont essentiellement basés sur la diffusion des ions Na+ dans les canaux des phases cristallisées avec changements d’état d’oxydation des métaux. Pour les composites fer-étain, les mécanismes sont plus complexes incluant insertion, conversion conduisant à la destruction des phases NASICON, puis formation d’alliages NaxSn. Les meilleures performances électrochimiques ont été obtenues pour Na1,5Fe0,5Ti1,5(PO4)3/C avec un potentiel de fonctionnement de 2,2 V vs Na+/Na0. Même si ces deux familles de matériaux peuvent être utilisées à plus bas potentiel, les performances doivent être améliorées pour envisager leur application comme électrode négative.]]></content:encoded>
    </item>
    <item>
      <title>[tel-01758937] Synthesis, high-pressure study and dielectric characterization of two lead-free perovskite materials : SrTi1-xZrxO3 and KNb1-xTaxO3</title>
      <description><![CDATA[Perovskite materials whose general chemical formula is ABO3 are one of the most study ferroelectrics due to the interesting properties that they have for technological applications. However, their properties are directly related to structural phase transitions that could depend of temperature, composition and pressure. In the studies presented here, we first examined the high-pressure behavior of two perovskite materials SrTi1-xZrxO3 (STZ) and KNb1-XTaXO3 (KNT), and we later continued to investigate different sintering techniques in order to improve the densification, dielectric and ferroelectric properties of K(Nb0.40Ta0.60)O3 and (KxNa1-x)Nb0.6Ta0.4O3 ceramics.High-pressure Raman scattering and X-ray diffraction investigations of SrTi1-xZrxO3 (x= 0.3, 0.4, 0.5, 0.6, 0.7) and KNb1-XTaXO3 (x=0.4, 0.5, 0.6, 0.9) powders were conducted in diamond anvil cells. Raman scattering experiments showed and increased of Raman modes with pressure for the STZ samples, which indicates that pressure induced phase transitions towards lower symmetry for these compounds.Moreover, high pressure Raman spectroscopy experiments showed a decrease of the Raman modes as the pressure was increased for the KNT samples, showing that pressure induced phase transitions towards higher symmetries. The evolution of the main Raman modes for the orthorhombic and tetragonal phases were followed until the cubic phase was reach, and allowed us to propose a pressure-composition phase diagram for the KNT compounds.Three different sintering techniques, sintered aids, two step sintering and spark plasma sintering, were used on K(Nb0.4Ta0.6)O3 and (KxNa1-x)Nb0.6Ta0.4O3 ceramics. The use of KF as sintered aid and the two step sintering method showed an improvement of the dielectric constant and dielectric losses of these samples. SPS samples presented a fine microstructure with the highest density and the best ferroelectric behavior. We did not detect any changes on the Curie temperature due the amount of Na but and increase of the dielectric constant and the ferroelectric properties was observed due to the amount of Na.]]></description>
      <pubDate>Wed, 27 Jun 2018 14:33:25 +0000</pubDate>
      <link>https://tel.archives-ouvertes.fr/tel-01758937</link>
      <guid>https://tel.archives-ouvertes.fr/tel-01758937</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Elizabeth Carolina Di Geronimo Camacho)</author>
      <dc:creator>Elizabeth Carolina Di Geronimo Camacho</dc:creator>
      <content:encoded><![CDATA[Perovskite materials whose general chemical formula is ABO3 are one of the most study ferroelectrics due to the interesting properties that they have for technological applications. However, their properties are directly related to structural phase transitions that could depend of temperature, composition and pressure. In the studies presented here, we first examined the high-pressure behavior of two perovskite materials SrTi1-xZrxO3 (STZ) and KNb1-XTaXO3 (KNT), and we later continued to investigate different sintering techniques in order to improve the densification, dielectric and ferroelectric properties of K(Nb0.40Ta0.60)O3 and (KxNa1-x)Nb0.6Ta0.4O3 ceramics.High-pressure Raman scattering and X-ray diffraction investigations of SrTi1-xZrxO3 (x= 0.3, 0.4, 0.5, 0.6, 0.7) and KNb1-XTaXO3 (x=0.4, 0.5, 0.6, 0.9) powders were conducted in diamond anvil cells. Raman scattering experiments showed and increased of Raman modes with pressure for the STZ samples, which indicates that pressure induced phase transitions towards lower symmetry for these compounds.Moreover, high pressure Raman spectroscopy experiments showed a decrease of the Raman modes as the pressure was increased for the KNT samples, showing that pressure induced phase transitions towards higher symmetries. The evolution of the main Raman modes for the orthorhombic and tetragonal phases were followed until the cubic phase was reach, and allowed us to propose a pressure-composition phase diagram for the KNT compounds.Three different sintering techniques, sintered aids, two step sintering and spark plasma sintering, were used on K(Nb0.4Ta0.6)O3 and (KxNa1-x)Nb0.6Ta0.4O3 ceramics. The use of KF as sintered aid and the two step sintering method showed an improvement of the dielectric constant and dielectric losses of these samples. SPS samples presented a fine microstructure with the highest density and the best ferroelectric behavior. We did not detect any changes on the Curie temperature due the amount of Na but and increase of the dielectric constant and the ferroelectric properties was observed due to the amount of Na.]]></content:encoded>
    </item>
    <item>
      <title>[tel-01758933] Towards new π-conjugated systems for photovoltaic applications</title>
      <description><![CDATA[Among renewable energies, the sunlight has by far the highest theoretical potential to meet the worldwide need in energy. Photovoltaic devices are thus currently the subject of intense research for low-cost conversion of sunlight into electrical power. In particular, organic photovoltaics have emerged as an interesting alternative to produce electricity due to their low manufacturing cost compared to silicon solar cells, their mechanical flexibility and the versatility of the possible chemical structures. In this dissertation, we focused our research on the development of new organic pi-conjugated materials for organic solar cells applications. Two types of solar cells have been studied during this work: bulk heterojunction and dye-sensitized solar cells. The charge transfer leading to the photocurrent is usually based on (i) a polymer donor and a fullerene acceptor in BHJ solar cells, such as the widely studied poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) materials and (ii) a metal oxide (titanium oxide) sensitized with a dye and an electrolyte in DSSCs. Despite power conversion efficiencies have reached 5 and 13 % respectively for these two types of devices, they still display several drawbacks that limit their commercialization. P3HT displays a narrow absorption of the solar spectrum thus limiting the conversion efficiency. To overcome this limitation, we combined P3HT with chromophores, i.e. porphyrins, having an extending absorption. Then, to ensure better charge transfer and extraction within the device, a cathode interfacial layer based on cationic pi-conjugated polyelectrolytes was added. Finally, dyes extracted from the biomass (chlorophyll a derivatives) were synthesized to replace the expensive ruthenium dyes in DSSCs. Since liquid electrolytes are volatile and corrosive, which considerably limit the DSSCs stability, solid polymer electrolytes were also developed as an alternative.]]></description>
      <pubDate>Wed, 27 Jun 2018 14:32:05 +0000</pubDate>
      <link>https://tel.archives-ouvertes.fr/tel-01758933</link>
      <guid>https://tel.archives-ouvertes.fr/tel-01758933</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Michèle Chevrier)</author>
      <dc:creator>Michèle Chevrier</dc:creator>
      <content:encoded><![CDATA[Among renewable energies, the sunlight has by far the highest theoretical potential to meet the worldwide need in energy. Photovoltaic devices are thus currently the subject of intense research for low-cost conversion of sunlight into electrical power. In particular, organic photovoltaics have emerged as an interesting alternative to produce electricity due to their low manufacturing cost compared to silicon solar cells, their mechanical flexibility and the versatility of the possible chemical structures. In this dissertation, we focused our research on the development of new organic pi-conjugated materials for organic solar cells applications. Two types of solar cells have been studied during this work: bulk heterojunction and dye-sensitized solar cells. The charge transfer leading to the photocurrent is usually based on (i) a polymer donor and a fullerene acceptor in BHJ solar cells, such as the widely studied poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) materials and (ii) a metal oxide (titanium oxide) sensitized with a dye and an electrolyte in DSSCs. Despite power conversion efficiencies have reached 5 and 13 % respectively for these two types of devices, they still display several drawbacks that limit their commercialization. P3HT displays a narrow absorption of the solar spectrum thus limiting the conversion efficiency. To overcome this limitation, we combined P3HT with chromophores, i.e. porphyrins, having an extending absorption. Then, to ensure better charge transfer and extraction within the device, a cathode interfacial layer based on cationic pi-conjugated polyelectrolytes was added. Finally, dyes extracted from the biomass (chlorophyll a derivatives) were synthesized to replace the expensive ruthenium dyes in DSSCs. Since liquid electrolytes are volatile and corrosive, which considerably limit the DSSCs stability, solid polymer electrolytes were also developed as an alternative.]]></content:encoded>
    </item>
    <item>
      <title>[tel-01758931] Développement d'électrodes modifiées et d'un bioréacteur électrochimique à flux continu pour une application aux biopiles microbiennes</title>
      <description><![CDATA[Les biopiles microbiennes sont des sources d’énergies renouvelables utilisant des bactéries qui convertissent une énergie chimique en électricité. Pour cela, l’anode doit collecter les électrons issus des microorganismes. La sélection d’un matériau d’anode possédant de grandes performances est d’une importance cruciale dans la construction d’une biopile microbienne. Le graphène est considéré comme un matériau prometteur avec de grandes possibilités d’application dans de nombreux domaines tels que les batteries Li-ion, les cellules photovoltaïques et les super condensateurs électrochimiques en raison de sa structure nanométrique. Ainsi, la modification de surface par de l’oxyde de graphène réduit a été appliquée à la construction d’anodes pour biopiles microbiennes. La cathode abiotique a aussi été étudiée puisqu’elle présente souvent une limitation cinétique vis-à-vis de la réduction de l’oxygène. Les potentialités des complexes organométalliques, et en particulier les phthalocyanines de nickel, ont été étudiés et appliquées à la construction d’une cathode pour biopile. Ainsi, une biopile hybride à deux compartiments a été construite en combinant une bioanode en mousse d’acier inoxydable modifiée par de l’oxyde de graphène réduite et une cathode en feutre de carbone modifiée avec de la phthalocyanine de nickel. La biopile microbienne ainsi construite utilise du lixiviat de terreau, comme source de microorganismes, pour le développement d’un biofilm électroactif à l’anode et présente une bonne stabilité dans le temps. Le graphène a permis d’obtenir une densité de puissance stable pendant une période 40 jours (24.8 mW/m² en présence d’oxygène pur). La cathode présentée dans ce travail a permis d’obtenir une densité de puissance supérieure à une cathode de platine (7.5 fois supérieur). Par ailleurs, un nouveau design de biopile à deux compartiments a été construit, afin de produire de l’électricité à partir d’une souche pure : Pseudomonas aeruginosa qui est connu pour la formation de biofilm électroactive. Un nouveau design a été proposé, permettant de travailler à alimentation constante et non plus en batch comme cela se fait de manière classique. Cette configuration permet de ne plus avoir de diminution de courant liée à un manque d’apport en carburant. Différents paramètres ont ainsi été explorés tel que le débit d’alimentation, la consommation en glucose dans le compartiment anodique, la variation de pH au cours du temps ainsi que l’évolution de la biomasse. Une première approche d’étude de corrélation de ces différents paramètres est proposée.]]></description>
      <pubDate>Wed, 27 Jun 2018 14:29:17 +0000</pubDate>
      <link>https://tel.archives-ouvertes.fr/tel-01758931</link>
      <guid>https://tel.archives-ouvertes.fr/tel-01758931</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Joffrey Champavert)</author>
      <dc:creator>Joffrey Champavert</dc:creator>
      <content:encoded><![CDATA[Les biopiles microbiennes sont des sources d’énergies renouvelables utilisant des bactéries qui convertissent une énergie chimique en électricité. Pour cela, l’anode doit collecter les électrons issus des microorganismes. La sélection d’un matériau d’anode possédant de grandes performances est d’une importance cruciale dans la construction d’une biopile microbienne. Le graphène est considéré comme un matériau prometteur avec de grandes possibilités d’application dans de nombreux domaines tels que les batteries Li-ion, les cellules photovoltaïques et les super condensateurs électrochimiques en raison de sa structure nanométrique. Ainsi, la modification de surface par de l’oxyde de graphène réduit a été appliquée à la construction d’anodes pour biopiles microbiennes. La cathode abiotique a aussi été étudiée puisqu’elle présente souvent une limitation cinétique vis-à-vis de la réduction de l’oxygène. Les potentialités des complexes organométalliques, et en particulier les phthalocyanines de nickel, ont été étudiés et appliquées à la construction d’une cathode pour biopile. Ainsi, une biopile hybride à deux compartiments a été construite en combinant une bioanode en mousse d’acier inoxydable modifiée par de l’oxyde de graphène réduite et une cathode en feutre de carbone modifiée avec de la phthalocyanine de nickel. La biopile microbienne ainsi construite utilise du lixiviat de terreau, comme source de microorganismes, pour le développement d’un biofilm électroactif à l’anode et présente une bonne stabilité dans le temps. Le graphène a permis d’obtenir une densité de puissance stable pendant une période 40 jours (24.8 mW/m² en présence d’oxygène pur). La cathode présentée dans ce travail a permis d’obtenir une densité de puissance supérieure à une cathode de platine (7.5 fois supérieur). Par ailleurs, un nouveau design de biopile à deux compartiments a été construit, afin de produire de l’électricité à partir d’une souche pure : Pseudomonas aeruginosa qui est connu pour la formation de biofilm électroactive. Un nouveau design a été proposé, permettant de travailler à alimentation constante et non plus en batch comme cela se fait de manière classique. Cette configuration permet de ne plus avoir de diminution de courant liée à un manque d’apport en carburant. Différents paramètres ont ainsi été explorés tel que le débit d’alimentation, la consommation en glucose dans le compartiment anodique, la variation de pH au cours du temps ainsi que l’évolution de la biomasse. Une première approche d’étude de corrélation de ces différents paramètres est proposée.]]></content:encoded>
    </item>
    <item>
      <title>[tel-01758936] Etude structurale de la synthèse de microsphères d’U1-xAmxO2±δ dédiées à la fabrication de couvertures chargées en américium</title>
      <description><![CDATA[Une des voies à l’étude permettant de réduire l’inventaire des déchets nucléaires, après recyclage du plutonium, est la transmutation hétérogène, en réacteurs à neutrons rapides, de l’américium (Am) en éléments chimiques à demi-vies courtes, voire stables. L’irradiation de l’Am nécessite la fabrication de pastilles d’U1-XAmXO2±δ. La voie CRMP (Calcined Resin Microsphere Pelletization) est actuellement privilégiée parmi les différents procédés envisagés. Elle se base, avant frittage, sur le pressage de microsphères d’oxyde mixte U1-XAmXO2±δ obtenues par conversion thermique de microsphères de résine échangeuse d’ions chargée en cations UO22+ et Am3+. Comparé à des voies de synthèse classique utilisant la métallurgie des poudres, le procédé CRMP permet de favoriser les étapes de mise en forme (forte coulabilité des microsphères) tout en limitant la dissémination de particules fines à base d’Am, hautement radioactives. Dans ce contexte, cette thèse s’attache à mener une caractérisation exhaustive des différentes étapes du procédé CRMP d’un point de vue mécanistique et structural. Ainsi, le mode de complexation des cations dans la résine a été déterminé, via la mise en évidence de groupements carboxyliques bidentés autour des éléments U et Am. L’étape de conversion thermique a également été suivie de manière in-situ, et les structures des différents composés oxydes formés, (U1-XAmX)3O8 et U1-XAmXO2±δ, ont été identifiées et caractérisées finement. La substitution de l’Am dans chacun des composés a été démontrée, ainsi que les déformations associées autour des cations. Finalement, le frittage des microsphères sous forme de pastilles d’U1-XAmXO2±δ a été caractérisé, révélant une densification en deux étapes. Ce comportement singulier est le résultat d’une réorganisation multi-échelle dans le matériau ayant lieu au cours du frittage, s’expliquant par la présence dans le cru de nanoparticules pré-frittant à basse température.]]></description>
      <pubDate>Wed, 27 Jun 2018 14:27:07 +0000</pubDate>
      <link>https://tel.archives-ouvertes.fr/tel-01758936</link>
      <guid>https://tel.archives-ouvertes.fr/tel-01758936</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Marie Caisso)</author>
      <dc:creator>Marie Caisso</dc:creator>
      <content:encoded><![CDATA[Une des voies à l’étude permettant de réduire l’inventaire des déchets nucléaires, après recyclage du plutonium, est la transmutation hétérogène, en réacteurs à neutrons rapides, de l’américium (Am) en éléments chimiques à demi-vies courtes, voire stables. L’irradiation de l’Am nécessite la fabrication de pastilles d’U1-XAmXO2±δ. La voie CRMP (Calcined Resin Microsphere Pelletization) est actuellement privilégiée parmi les différents procédés envisagés. Elle se base, avant frittage, sur le pressage de microsphères d’oxyde mixte U1-XAmXO2±δ obtenues par conversion thermique de microsphères de résine échangeuse d’ions chargée en cations UO22+ et Am3+. Comparé à des voies de synthèse classique utilisant la métallurgie des poudres, le procédé CRMP permet de favoriser les étapes de mise en forme (forte coulabilité des microsphères) tout en limitant la dissémination de particules fines à base d’Am, hautement radioactives. Dans ce contexte, cette thèse s’attache à mener une caractérisation exhaustive des différentes étapes du procédé CRMP d’un point de vue mécanistique et structural. Ainsi, le mode de complexation des cations dans la résine a été déterminé, via la mise en évidence de groupements carboxyliques bidentés autour des éléments U et Am. L’étape de conversion thermique a également été suivie de manière in-situ, et les structures des différents composés oxydes formés, (U1-XAmX)3O8 et U1-XAmXO2±δ, ont été identifiées et caractérisées finement. La substitution de l’Am dans chacun des composés a été démontrée, ainsi que les déformations associées autour des cations. Finalement, le frittage des microsphères sous forme de pastilles d’U1-XAmXO2±δ a été caractérisé, révélant une densification en deux étapes. Ce comportement singulier est le résultat d’une réorganisation multi-échelle dans le matériau ayant lieu au cours du frittage, s’expliquant par la présence dans le cru de nanoparticules pré-frittant à basse température.]]></content:encoded>
    </item>
    <item>
      <title>[hal-01824396] Titin-Based Modulation of Calcium Sensitivity of Active Tension in Mouse Skinned Cardiac Myocytes Materials and Methods Preparations and Solutions</title>
      <description><![CDATA[We studied the effect of titin-based passive force on the length dependence of activation of cardiac myocytes to explore whether titin may play a role in the generation of systolic force. Force-pCa relations were measured at sarcomere lengths (SLs) of 2.0 and 2.3 m. Passive tension at 2.3 m SL was varied from 1 to 10 mN/mm 2 by adjusting the characteristics of the stretch imposed on the passive cell before activation. Relative to 2.0 m SL, the force-pCa curve at 2.3 m SL and low passive tension showed a leftward shift (pCa 50 [change in pCa at half-maximal activation]) of 0.090.02 pCa units while at 2.3 m SL and high passive tension the shift was increased to 0.250.03 pCa units. Passive tension also increased pCa 50 at reduced interfilament lattice spacing achieved with dextran. We tested whether titin-based passive tension influences the interfilament lattice spacing by measuring the width of the myocyte and by using small-angle x-ray diffraction of mouse left ventricular wall muscle. Cell width and interfilament lattice spacing varied inversely with passive tension, in the presence and absence of dextran. The passive tension effect on length-dependent activation may therefore result from a radial titin-based force that modulates the interfilament lattice spacing. (Circ Res. 2001;88:1028-1035.)]]></description>
      <pubDate>Wed, 27 Jun 2018 14:26:25 +0000</pubDate>
      <link>https://hal.umontpellier.fr/hal-01824396</link>
      <guid>https://hal.umontpellier.fr/hal-01824396</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Olivier Cazorla)</author>
      <dc:creator>Olivier Cazorla</dc:creator>
      <content:encoded><![CDATA[We studied the effect of titin-based passive force on the length dependence of activation of cardiac myocytes to explore whether titin may play a role in the generation of systolic force. Force-pCa relations were measured at sarcomere lengths (SLs) of 2.0 and 2.3 m. Passive tension at 2.3 m SL was varied from 1 to 10 mN/mm 2 by adjusting the characteristics of the stretch imposed on the passive cell before activation. Relative to 2.0 m SL, the force-pCa curve at 2.3 m SL and low passive tension showed a leftward shift (pCa 50 [change in pCa at half-maximal activation]) of 0.090.02 pCa units while at 2.3 m SL and high passive tension the shift was increased to 0.250.03 pCa units. Passive tension also increased pCa 50 at reduced interfilament lattice spacing achieved with dextran. We tested whether titin-based passive tension influences the interfilament lattice spacing by measuring the width of the myocyte and by using small-angle x-ray diffraction of mouse left ventricular wall muscle. Cell width and interfilament lattice spacing varied inversely with passive tension, in the presence and absence of dextran. The passive tension effect on length-dependent activation may therefore result from a radial titin-based force that modulates the interfilament lattice spacing. (Circ Res. 2001;88:1028-1035.)]]></content:encoded>
    </item>
    <item>
      <title>[hal-00753335] An iterative approach to build relevant ontology-aware data-driven models</title>
      <description><![CDATA[In many fields involving complex environments or living organisms, data-driven models are useful to make simulations in order to extrapolate costly experiments and to design decision-support tools. Learning methods can be used to build interpretable models from data. However, to be really useful, such models must be trusted by their users. From this perspective, the domain expert knowledge can be collected and modelled to help guiding the learning process and to increase the confidence in the resulting models, as well as their relevance. Another issue is to design relevant ontologies to formalize complex knowledge. Interpretable predictive models can help in this matter. In this paper, we propose a generic iterative approach to design ontology-aware and relevant data-driven models. It is based upon an ontology to model the domain knowledge and a learning method to build the interpretable models (decision trees in this paper). Subjective and objective evaluations are both involved in the process. A case study in the domain of Food Industry demonstrates the interest of this approach.]]></description>
      <pubDate>Wed, 27 Jun 2018 14:16:04 +0000</pubDate>
      <link>https://hal.archives-ouvertes.fr/hal-00753335</link>
      <guid>https://hal.archives-ouvertes.fr/hal-00753335</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Rallou Thomopoulos)</author>
      <dc:creator>Rallou Thomopoulos</dc:creator>
      <content:encoded><![CDATA[In many fields involving complex environments or living organisms, data-driven models are useful to make simulations in order to extrapolate costly experiments and to design decision-support tools. Learning methods can be used to build interpretable models from data. However, to be really useful, such models must be trusted by their users. From this perspective, the domain expert knowledge can be collected and modelled to help guiding the learning process and to increase the confidence in the resulting models, as well as their relevance. Another issue is to design relevant ontologies to formalize complex knowledge. Interpretable predictive models can help in this matter. In this paper, we propose a generic iterative approach to design ontology-aware and relevant data-driven models. It is based upon an ontology to model the domain knowledge and a learning method to build the interpretable models (decision trees in this paper). Subjective and objective evaluations are both involved in the process. A case study in the domain of Food Industry demonstrates the interest of this approach.]]></content:encoded>
    </item>
    <item>
      <title>[hal-00669378] Parameters uncertainties and error propagation in modified atmosphere packaging modelling</title>
      <description><![CDATA[Mathematical models are instrumental tools to predict gas (O2 and CO2) evolution in headspaces of Modified Atmosphere Packaging (MAP). Such models simplify the package design steps as they allow engineers to estimate the optimal values of packaging permeability for maintaining the quality and safety of the packed food. However, these models typically require specifying several input parameter values (such as maximal respiration rates) that are obtained from experimental data and are characterized by high uncertainties due to biological variation. Although treating and modelling this uncertainty is essential to ensure the robustness of designed MAPs, this subject has seldom been considered in the literature. In this work, we describe an optimisation system based on a MAP mathematical model that determines optimal permeabilities of packaging, given certain food parameters. To integrate uncertainties in the model while keeping the optimisation computational burden relatively low, we propose to use an approach based on interval analysis rather than the more classical probabilistic approach. The approach has two advantages: it makes a minimal amount of unverified assumption concerning uncertainties, and it requires only a few evaluations of the model. The results of these uncertainty studies are optimal values of permeabilities described by fuzzy sets. This approach was conducted on three case studies: chicory, mushrooms and blueberry. Sensitivity analysis on input parameters in the model MAP was also performed in order to point out that parameter influences are dependent on the considered fruit or vegetable. A comparison of the interval analysis methodology with the probabilistic one (known as Monte Carlo) was then performed and discussed.]]></description>
      <pubDate>Wed, 27 Jun 2018 14:14:02 +0000</pubDate>
      <link>https://hal.archives-ouvertes.fr/hal-00669378</link>
      <guid>https://hal.archives-ouvertes.fr/hal-00669378</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Valérie Guillard)</author>
      <dc:creator>Valérie Guillard</dc:creator>
      <content:encoded><![CDATA[Mathematical models are instrumental tools to predict gas (O2 and CO2) evolution in headspaces of Modified Atmosphere Packaging (MAP). Such models simplify the package design steps as they allow engineers to estimate the optimal values of packaging permeability for maintaining the quality and safety of the packed food. However, these models typically require specifying several input parameter values (such as maximal respiration rates) that are obtained from experimental data and are characterized by high uncertainties due to biological variation. Although treating and modelling this uncertainty is essential to ensure the robustness of designed MAPs, this subject has seldom been considered in the literature. In this work, we describe an optimisation system based on a MAP mathematical model that determines optimal permeabilities of packaging, given certain food parameters. To integrate uncertainties in the model while keeping the optimisation computational burden relatively low, we propose to use an approach based on interval analysis rather than the more classical probabilistic approach. The approach has two advantages: it makes a minimal amount of unverified assumption concerning uncertainties, and it requires only a few evaluations of the model. The results of these uncertainty studies are optimal values of permeabilities described by fuzzy sets. This approach was conducted on three case studies: chicory, mushrooms and blueberry. Sensitivity analysis on input parameters in the model MAP was also performed in order to point out that parameter influences are dependent on the considered fruit or vegetable. A comparison of the interval analysis methodology with the probabilistic one (known as Monte Carlo) was then performed and discussed.]]></content:encoded>
    </item>
    <item>
      <title>[hal-01824408] Differential Expression of Cardiac Titin Isoforms and Modulation of Cellular Stiffness</title>
      <description><![CDATA[Extension of the I-band segment of titin gives rise to part of the diastolic force of cardiac muscle. Previous studies of human cardiac titin transcripts suggested a series of differential splicing events in the I-band segment of titin leading to the so-called N2A and N2B isoform transcripts. Here we investigated titin expression at the protein level in a wide range of mammalian species. Results indicate that the myocardium coexpresses 2 distinct titin isoforms: a smaller isoform containing the N2B element only (N2B titin) and a larger isoform with both the N2B and N2A elements (N2BA titin). The expression ratio of large N2BA to small N2B titin isoforms was found to vary greatly in different species; eg, in the left ventricle the ratio is 0.05 in mouse and 1.5 in pig. Differences in the expression ratio were also found between atria and ventricles and between different layers of the ventricular wall. Immunofluorescence experiments with isoform-specific antibodies suggest that coexpression of these isoforms takes place at the single-myocyte level. The diastolic properties of single cardiac myocytes isolated from various species expressing high levels of the small (rat and mouse) or large (pig) titin isoform were studied. On average, pig myocytes are significantly less stiff than mouse and rat myocytes. Gel analysis indicates that this result cannot be explained by varying amounts of titin in mouse and pig myocardium. Rather, low stiffness of pig myocytes can be explained by its high expression level of the large isoform: the longer extensible region of this isoform results in a lower fractional extension for a given sarcomere length and hence a lower force. Implications of our findings to cardiac function are discussed. (Circ Res. 2000;86:59-67.)]]></description>
      <pubDate>Wed, 27 Jun 2018 13:25:15 +0000</pubDate>
      <link>https://hal.umontpellier.fr/hal-01824408</link>
      <guid>https://hal.umontpellier.fr/hal-01824408</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Olivier Cazorla)</author>
      <dc:creator>Olivier Cazorla</dc:creator>
      <content:encoded><![CDATA[Extension of the I-band segment of titin gives rise to part of the diastolic force of cardiac muscle. Previous studies of human cardiac titin transcripts suggested a series of differential splicing events in the I-band segment of titin leading to the so-called N2A and N2B isoform transcripts. Here we investigated titin expression at the protein level in a wide range of mammalian species. Results indicate that the myocardium coexpresses 2 distinct titin isoforms: a smaller isoform containing the N2B element only (N2B titin) and a larger isoform with both the N2B and N2A elements (N2BA titin). The expression ratio of large N2BA to small N2B titin isoforms was found to vary greatly in different species; eg, in the left ventricle the ratio is 0.05 in mouse and 1.5 in pig. Differences in the expression ratio were also found between atria and ventricles and between different layers of the ventricular wall. Immunofluorescence experiments with isoform-specific antibodies suggest that coexpression of these isoforms takes place at the single-myocyte level. The diastolic properties of single cardiac myocytes isolated from various species expressing high levels of the small (rat and mouse) or large (pig) titin isoform were studied. On average, pig myocytes are significantly less stiff than mouse and rat myocytes. Gel analysis indicates that this result cannot be explained by varying amounts of titin in mouse and pig myocardium. Rather, low stiffness of pig myocytes can be explained by its high expression level of the large isoform: the longer extensible region of this isoform results in a lower fractional extension for a given sarcomere length and hence a lower force. Implications of our findings to cardiac function are discussed. (Circ Res. 2000;86:59-67.)]]></content:encoded>
    </item>
    <item>
      <title>[halshs-01592836] Histoire du droit du travail dans les colonies françaises (1848-1960)</title>
      <description><![CDATA[[...]]]></description>
      <pubDate>Wed, 27 Jun 2018 12:54:02 +0000</pubDate>
      <link>https://halshs.archives-ouvertes.fr/halshs-01592836</link>
      <guid>https://halshs.archives-ouvertes.fr/halshs-01592836</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Jean-Pierre Le Crom)</author>
      <dc:creator>Jean-Pierre Le Crom</dc:creator>
      <content:encoded><![CDATA[[...]]]></content:encoded>
    </item>
    <item>
      <title>[hal-01824366] Late exercise training improves non-uniformity of transmural myocardial function in rats with ischaemic heart failure</title>
      <description><![CDATA[Aims The exercise-induced beneficial mechanisms after long-term myocardial infarction (MI) are incompletely understood. The present study evaluated the effect of treadmill exercise training (5 weeks), started at a late stage of heart failure (HF) (13 weeks post-MI), on rat left ventricle remodelling and dysfunction of the regional global and cellular contractile functions. Methods and results In vivo echocardiography confirmed that sub-endocardial (ENDO) layers contract more (þ86%) and faster (þ50%) than the sub-epicardial (EPI) layers. This gradient was lost in MI rats due to a predominant reduction in the ENDO layer contractility. Exercise partially restored the amplitude and velocity of ENDO contraction, resulting in a partial recovery of the pump function indexed by the aortic blood-flow velocity time integral. At the cellular level, MI impaired ENDO contractile properties by reducing cell shortening (10–7%), calcium transient, and myofilament Ca 2þ sensitivity. These alterations were normalized by exercise. Sarcoplasmic reticulum Ca 2þ-ATPase (SERCA)2a expression and myosin light chain (MLC)-2 phosphorylation in ENDO cells were significantly reduced after MI and were restored by exercise. The EPI layer was only slightly reduced in vivo without cellular alterations. Conclusion This study shows that exercise performed at a late stage after MI restored a transmural non-uniformity of myocardium lost during HF. Recoveries of Ca 2þ homeostasis and myofilament function of cardiomyocytes contribute to this beneficial effect.]]></description>
      <pubDate>Wed, 27 Jun 2018 12:46:34 +0000</pubDate>
      <link>https://hal.umontpellier.fr/hal-01824366</link>
      <guid>https://hal.umontpellier.fr/hal-01824366</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Younss Ait Mou)</author>
      <dc:creator>Younss Ait Mou</dc:creator>
      <content:encoded><![CDATA[Aims The exercise-induced beneficial mechanisms after long-term myocardial infarction (MI) are incompletely understood. The present study evaluated the effect of treadmill exercise training (5 weeks), started at a late stage of heart failure (HF) (13 weeks post-MI), on rat left ventricle remodelling and dysfunction of the regional global and cellular contractile functions. Methods and results In vivo echocardiography confirmed that sub-endocardial (ENDO) layers contract more (þ86%) and faster (þ50%) than the sub-epicardial (EPI) layers. This gradient was lost in MI rats due to a predominant reduction in the ENDO layer contractility. Exercise partially restored the amplitude and velocity of ENDO contraction, resulting in a partial recovery of the pump function indexed by the aortic blood-flow velocity time integral. At the cellular level, MI impaired ENDO contractile properties by reducing cell shortening (10–7%), calcium transient, and myofilament Ca 2þ sensitivity. These alterations were normalized by exercise. Sarcoplasmic reticulum Ca 2þ-ATPase (SERCA)2a expression and myosin light chain (MLC)-2 phosphorylation in ENDO cells were significantly reduced after MI and were restored by exercise. The EPI layer was only slightly reduced in vivo without cellular alterations. Conclusion This study shows that exercise performed at a late stage after MI restored a transmural non-uniformity of myocardium lost during HF. Recoveries of Ca 2þ homeostasis and myofilament function of cardiomyocytes contribute to this beneficial effect.]]></content:encoded>
    </item>
    <item>
      <title>[pasteur-01247037] Socio-economic and Climate Factors Associated with Dengue Fever Spatial Heterogeneity: A Worked Example in New Caledonia</title>
      <description><![CDATA[Understanding the factors underlying the spatio-temporal distribution of infectious diseases provides useful information regarding their prevention and control. Dengue fever spatio-temporal patterns result from complex interactions between the virus, the host, and the vector. These interactions can be influenced by environmental conditions. Our objectives were to analyse dengue fever spatial distribution over New Caledonia during epidemic years, to identify some of the main underlying factors, and to predict the spatial evolution of dengue fever under changing climatic conditions, at the 2100 horizon. We used principal component analysis and support vector machines to analyse and model the influence of climate and socio-economic variables on the mean spatial distribution of 24,272 dengue cases reported from 1995 to 2012 in thirty-three communes of New Caledonia. We then modelled and estimated the future evolution of dengue incidence rates using a regional downscaling of future climate projections. The spatial distribution of dengue fever cases is highly heterogeneous. The variables most associated with this observed heterogeneity are the mean temperature, the mean number of people per premise, and the mean percentage of unemployed people, a variable highly correlated with people's way of life. Rainfall does not seem to play an important role in the spatial distribution of dengue cases during epidemics. By the end of the 21st century, if temperature increases by approximately 3°C, mean incidence rates during epidemics could double. In New Caledonia, a subtropical insular environment, both temperature and socio-economic conditions are influencing the spatial spread of dengue fever. Extension of this study to other countries worldwide should improve the knowledge about climate influence on dengue burden and about the complex interplay between different factors. This study presents a methodology that can be used as a step by step guide to model dengue spatial heterogeneity in other countries.]]></description>
      <pubDate>Wed, 27 Jun 2018 12:14:02 +0000</pubDate>
      <link>https://hal-riip.archives-ouvertes.fr/pasteur-01247037</link>
      <guid>https://hal-riip.archives-ouvertes.fr/pasteur-01247037</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Magali Teurlai)</author>
      <dc:creator>Magali Teurlai</dc:creator>
      <content:encoded><![CDATA[Understanding the factors underlying the spatio-temporal distribution of infectious diseases provides useful information regarding their prevention and control. Dengue fever spatio-temporal patterns result from complex interactions between the virus, the host, and the vector. These interactions can be influenced by environmental conditions. Our objectives were to analyse dengue fever spatial distribution over New Caledonia during epidemic years, to identify some of the main underlying factors, and to predict the spatial evolution of dengue fever under changing climatic conditions, at the 2100 horizon. We used principal component analysis and support vector machines to analyse and model the influence of climate and socio-economic variables on the mean spatial distribution of 24,272 dengue cases reported from 1995 to 2012 in thirty-three communes of New Caledonia. We then modelled and estimated the future evolution of dengue incidence rates using a regional downscaling of future climate projections. The spatial distribution of dengue fever cases is highly heterogeneous. The variables most associated with this observed heterogeneity are the mean temperature, the mean number of people per premise, and the mean percentage of unemployed people, a variable highly correlated with people's way of life. Rainfall does not seem to play an important role in the spatial distribution of dengue cases during epidemics. By the end of the 21st century, if temperature increases by approximately 3°C, mean incidence rates during epidemics could double. In New Caledonia, a subtropical insular environment, both temperature and socio-economic conditions are influencing the spatial spread of dengue fever. Extension of this study to other countries worldwide should improve the knowledge about climate influence on dengue burden and about the complex interplay between different factors. This study presents a methodology that can be used as a step by step guide to model dengue spatial heterogeneity in other countries.]]></content:encoded>
    </item>
    <item>
      <title>[hal-00337060] West African Monsoon observed with ground-based GPS receivers during African Monsoon Multidisciplinary Analysis (AMMA)</title>
      <description><![CDATA[The impact of stratospheric ozone on the tropospheric general circulation of the Southern Hemisphere (SH) is examined with a set of chemistry‐climate models participating in the Stratospheric Processes and their Role in Climate (SPARC)/Chemistry‐Climate Model Validation project phase 2 (CCMVal‐2). Model integrations of both the past and future climates reveal the crucial role of stratospheric ozone in driving SH circulation change: stronger ozone depletion in late spring generally leads to greater poleward displacement and intensification of the tropospheric midlatitude jet, and greater expansion of the SH Hadley cell in the summer. These circulation changes are systematic as poleward displacement of the jet is typically accompanied by intensification of the jet and expansion of the Hadley cell. Overall results are compared with coupled models participating in the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4), and possible mechanisms are discussed. While the tropospheric circulation response appears quasi‐linearly related to stratospheric ozone changes, the quantitative response to a given forcing varies considerably from one model to another. This scatter partly results from differences in model climatology. It is shown that poleward intensification of the westerly jet is generally stronger in models whose climatological jet is biased toward lower latitudes. This result is discussed in the context of quasi‐geostrophic zonal mean dynamics.]]></description>
      <pubDate>Wed, 27 Jun 2018 11:54:50 +0000</pubDate>
      <link>https://hal.archives-ouvertes.fr/hal-00337060</link>
      <guid>https://hal.archives-ouvertes.fr/hal-00337060</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Olivier Bock)</author>
      <dc:creator>Olivier Bock</dc:creator>
      <content:encoded><![CDATA[The impact of stratospheric ozone on the tropospheric general circulation of the Southern Hemisphere (SH) is examined with a set of chemistry‐climate models participating in the Stratospheric Processes and their Role in Climate (SPARC)/Chemistry‐Climate Model Validation project phase 2 (CCMVal‐2). Model integrations of both the past and future climates reveal the crucial role of stratospheric ozone in driving SH circulation change: stronger ozone depletion in late spring generally leads to greater poleward displacement and intensification of the tropospheric midlatitude jet, and greater expansion of the SH Hadley cell in the summer. These circulation changes are systematic as poleward displacement of the jet is typically accompanied by intensification of the jet and expansion of the Hadley cell. Overall results are compared with coupled models participating in the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4), and possible mechanisms are discussed. While the tropospheric circulation response appears quasi‐linearly related to stratospheric ozone changes, the quantitative response to a given forcing varies considerably from one model to another. This scatter partly results from differences in model climatology. It is shown that poleward intensification of the westerly jet is generally stronger in models whose climatological jet is biased toward lower latitudes. This result is discussed in the context of quasi‐geostrophic zonal mean dynamics.]]></content:encoded>
    </item>
    <item>
      <title>[hal-01795621] Implementing ecological intensification in fish farming: definition and principles from contrasting experiences</title>
      <description><![CDATA[Ecological intensification is a new concept in agriculture that addresses the double challenge of maintaining a level of production sufficient to support needs of human populations and respecting the environment in order to conserve the natural world and human quality of life. This article adapts this concept to fish farming using agroecological principles and the ecosystem services framework. The method was developed from the study of published literature and applications at four study sites chosen for their differences in production intensity: polyculture ponds in France, integrated pig and pond polyculture in Brazil, the culture of striped catfish in Indonesia and a recirculating salmon aquaculture system in France. The study of stakeholders' perceptions of ecosystem services combined with environmental assessment through Life Cycle Assessment and Emergy accounting allowed development of an assessment tool that was used as a basis for co-building evolution scenarios. From this experience, ecological intensifica-tion of aquaculture was defined as the use of ecological processes and functions to increase productivity, strengthen ecosystem services and decrease disservices. It is based on aquaecosystem and biodiversity management and the use of local and traditional knowledge. Expected consequences for farming systems consist of greater autonomy, efficiency and better integration into their surrounding territories. Ecological intensification requires territorial governance and helps improve it from a sustainable development perspective.]]></description>
      <pubDate>Wed, 27 Jun 2018 11:12:16 +0000</pubDate>
      <link>https://hal.archives-ouvertes.fr/hal-01795621</link>
      <guid>https://hal.archives-ouvertes.fr/hal-01795621</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Joël Aubin)</author>
      <dc:creator>Joël Aubin</dc:creator>
      <content:encoded><![CDATA[Ecological intensification is a new concept in agriculture that addresses the double challenge of maintaining a level of production sufficient to support needs of human populations and respecting the environment in order to conserve the natural world and human quality of life. This article adapts this concept to fish farming using agroecological principles and the ecosystem services framework. The method was developed from the study of published literature and applications at four study sites chosen for their differences in production intensity: polyculture ponds in France, integrated pig and pond polyculture in Brazil, the culture of striped catfish in Indonesia and a recirculating salmon aquaculture system in France. The study of stakeholders' perceptions of ecosystem services combined with environmental assessment through Life Cycle Assessment and Emergy accounting allowed development of an assessment tool that was used as a basis for co-building evolution scenarios. From this experience, ecological intensifica-tion of aquaculture was defined as the use of ecological processes and functions to increase productivity, strengthen ecosystem services and decrease disservices. It is based on aquaecosystem and biodiversity management and the use of local and traditional knowledge. Expected consequences for farming systems consist of greater autonomy, efficiency and better integration into their surrounding territories. Ecological intensification requires territorial governance and helps improve it from a sustainable development perspective.]]></content:encoded>
    </item>
    <item>
      <title>[hal-01824286] Systems approach to the study of stretch and arrhythmias in right ventricular failure induced in rats by monocrotaline.</title>
      <description><![CDATA[We demonstrate the synergistic benefits of using multiple technologies to investigate complex multi-scale biological responses. The combination of reductionist and integrative methodologies can reveal novel insights into mechanisms of action by tracking changes of in vivo phenomena to alterations in protein activity (or vice versa). We have applied this approach to electrical and mechanical remodelling in right ventricular failure caused by monocrotaline-induced pulmonary artery hypertension in rats. We show arrhythmogenic T-wave alternans in the ECG of conscious heart failure animals. Optical mapping of isolated hearts revealed discordant action potential duration (APD) alternans. Potential causes of the arrhythmic substrate; structural remodelling and/or steep APD restitution and dispersion were observed, with specific remodelling of the Right Ventricular Outflow Tract. At the myocyte level, [Ca(2+)]i transient alternans were observed together with decreased activity, gene and protein expression of the sarcoplasmic reticulum Ca(2+)-ATPase (SERCA). Computer simulations of the electrical and structural remodelling suggest both contribute to a less stable substrate. Echocardiography was used to estimate increased wall stress in failure, in vivo. Stretch of intact and skinned single myocytes revealed no effect on the Frank-Starling mechanism in failing myocytes. In isolated hearts acute stretch-induced arrhythmias occurred in all preparations. Significant shortening of the early APD was seen in control but not failing hearts. These observations may be linked to changes in the gene expression of candidate mechanosensitive ion channels (MSCs) TREK-1 and TRPC1/6. Computer simulations incorporating MSCs and changes in ion channels with failure, based on altered gene expression, largely reproduced experimental observations.]]></description>
      <pubDate>Wed, 27 Jun 2018 09:59:59 +0000</pubDate>
      <link>https://hal.umontpellier.fr/hal-01824286</link>
      <guid>https://hal.umontpellier.fr/hal-01824286</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (David Benoist)</author>
      <dc:creator>David Benoist</dc:creator>
      <content:encoded><![CDATA[We demonstrate the synergistic benefits of using multiple technologies to investigate complex multi-scale biological responses. The combination of reductionist and integrative methodologies can reveal novel insights into mechanisms of action by tracking changes of in vivo phenomena to alterations in protein activity (or vice versa). We have applied this approach to electrical and mechanical remodelling in right ventricular failure caused by monocrotaline-induced pulmonary artery hypertension in rats. We show arrhythmogenic T-wave alternans in the ECG of conscious heart failure animals. Optical mapping of isolated hearts revealed discordant action potential duration (APD) alternans. Potential causes of the arrhythmic substrate; structural remodelling and/or steep APD restitution and dispersion were observed, with specific remodelling of the Right Ventricular Outflow Tract. At the myocyte level, [Ca(2+)]i transient alternans were observed together with decreased activity, gene and protein expression of the sarcoplasmic reticulum Ca(2+)-ATPase (SERCA). Computer simulations of the electrical and structural remodelling suggest both contribute to a less stable substrate. Echocardiography was used to estimate increased wall stress in failure, in vivo. Stretch of intact and skinned single myocytes revealed no effect on the Frank-Starling mechanism in failing myocytes. In isolated hearts acute stretch-induced arrhythmias occurred in all preparations. Significant shortening of the early APD was seen in control but not failing hearts. These observations may be linked to changes in the gene expression of candidate mechanosensitive ion channels (MSCs) TREK-1 and TRPC1/6. Computer simulations incorporating MSCs and changes in ion channels with failure, based on altered gene expression, largely reproduced experimental observations.]]></content:encoded>
    </item>
    <item>
      <title>[tel-01824094] Etude des régulations géniques impliquées dans le maintien de l’homéostasie du fer chez Arabidopsis thaliana.</title>
      <description><![CDATA[Le fer (Fe) est un élément indispensable à la vie. Sa capacité à perdre ou à gagner un électron lui permet d’être un cofacteur de choix pour de nombreuses réactions enzymatiques telles que la photosynthèse, la synthèse d’ADN ou la respiration. Cependant, le fer est très réactif et potentiellement toxique pour la cellule. Les plantes doivent donc strictement réguler leur homéostasie en fer afin d’éviter toute carence ou tout excès préjudiciable pour leur organisme. Parmi les acteurs du maintien de l’équilibre ferrique, les ferritines jouent un rôle majeur. Chez les végétaux, elles sont principalement régulées transcriptionnellement. Le gène modèle des ferritines, AtFER1, est régulé par au moins trois voies indépendantes (l’excès de fer, la carence en phosphate, et l’alternance jour/nuit). Toutefois, la façon dont ces signaux s’intègrent au niveau de son promoteur n’est pas formellement établie. Mon travail a consisté à mettre en place une étude fonctionnelle du promoteur d’AtFER1 en caractérisant des lignées stables d’Arabidopsis thaliana exprimant le gène rapporteur GUS (β-glucuronidase) sous le contrôle de différentes versions du promoteur d’AtFER1 (délétions en 5’ et en 3’, mutagenèse dirigée) selon différents traitements (e.g. disponibilité en fer). Cette approche a mis en évidence le rôle clef de certains éléments cis du promoteur. Des cribles simple hybride chez la levure sur ces éléments ont permis l’identification du facteur de transcription bHLH105/ILR3 comme régulateur potentiel d’AtFER1. Une caractérisation moléculaire et physiologique des mutants ilr3 a démontré l’implication de ce facteur dans la réponse des plantes à l’excès de fer. Elle a aussi mis en évidence qu’ILR3 avait un rôle central d’intégrateur dans l’homéostasie du fer chez les plantes. D’autre part, des données suggéraient qu’un long ARN non codant (At5g01595) pouvait potentiellement réguler AtFER1. Une caractérisation des mécanismes potentiellement impliqués a démontré que cette régulation n’était pas avérée.Les mécanismes moléculaires et physiologiques mis en place par les végétaux en réponse à une carence en fer sont relativement bien décrits. A l’inverse, peu d’informations sur la réponse des plantes à un « excès » de fer sont disponibles. Dans ce contexte, une expérience visant à décrypter, au niveau du transcriptome (puces à ADN), la dynamique de la réponse précoce (de quelques minutes à 2 heures) à un excès de fer a été mise en place. Une analyse de variance a été réalisée sur les données d’expression générées afin d’identifier les gènes dont l’expression est affectée par le traitement. Nous nous sommes plus particulièrement focalisés sur l’identification de facteurs de transcription, acteurs majeurs du maintien de l’homéostasie du fer. Parmi eux, WRKY33, WRKY40, ZAT10 et MYB51, tous liés à la réponse au ROS, semblent avoir un rôle clé dans la réponse précoce au fer.D’autre part, un mécanisme clé de l’homéostasie du fer est le prélèvement. Une précédente étude a montré que la nutrition en fer était facilitée par la synthèse et la sécrétion de composés phénoliques via le transporteur PDR9. Une caractérisation des mutants pdr9 a permis d’établir que d’une part (i) ses composés pouvaient être stockés dans les vacuoles des cellules racinaires, et d’autre part (ii) qu’ils permettaient l’entrée de fer via le système de prélèvement gouverné par le mécanisme FRO2/IRT1.Mes travaux de thèse ont permis d’apporter des éléments nouveaux sur les mécanismes moléculaires et physiologiques impliqués dans le contrôle de l’homéostasie du fer chez Arabidopsis.]]></description>
      <pubDate>Wed, 27 Jun 2018 09:47:17 +0000</pubDate>
      <link>https://tel.archives-ouvertes.fr/tel-01824094</link>
      <guid>https://tel.archives-ouvertes.fr/tel-01824094</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Nicolas Tissot)</author>
      <dc:creator>Nicolas Tissot</dc:creator>
      <content:encoded><![CDATA[Le fer (Fe) est un élément indispensable à la vie. Sa capacité à perdre ou à gagner un électron lui permet d’être un cofacteur de choix pour de nombreuses réactions enzymatiques telles que la photosynthèse, la synthèse d’ADN ou la respiration. Cependant, le fer est très réactif et potentiellement toxique pour la cellule. Les plantes doivent donc strictement réguler leur homéostasie en fer afin d’éviter toute carence ou tout excès préjudiciable pour leur organisme. Parmi les acteurs du maintien de l’équilibre ferrique, les ferritines jouent un rôle majeur. Chez les végétaux, elles sont principalement régulées transcriptionnellement. Le gène modèle des ferritines, AtFER1, est régulé par au moins trois voies indépendantes (l’excès de fer, la carence en phosphate, et l’alternance jour/nuit). Toutefois, la façon dont ces signaux s’intègrent au niveau de son promoteur n’est pas formellement établie. Mon travail a consisté à mettre en place une étude fonctionnelle du promoteur d’AtFER1 en caractérisant des lignées stables d’Arabidopsis thaliana exprimant le gène rapporteur GUS (β-glucuronidase) sous le contrôle de différentes versions du promoteur d’AtFER1 (délétions en 5’ et en 3’, mutagenèse dirigée) selon différents traitements (e.g. disponibilité en fer). Cette approche a mis en évidence le rôle clef de certains éléments cis du promoteur. Des cribles simple hybride chez la levure sur ces éléments ont permis l’identification du facteur de transcription bHLH105/ILR3 comme régulateur potentiel d’AtFER1. Une caractérisation moléculaire et physiologique des mutants ilr3 a démontré l’implication de ce facteur dans la réponse des plantes à l’excès de fer. Elle a aussi mis en évidence qu’ILR3 avait un rôle central d’intégrateur dans l’homéostasie du fer chez les plantes. D’autre part, des données suggéraient qu’un long ARN non codant (At5g01595) pouvait potentiellement réguler AtFER1. Une caractérisation des mécanismes potentiellement impliqués a démontré que cette régulation n’était pas avérée.Les mécanismes moléculaires et physiologiques mis en place par les végétaux en réponse à une carence en fer sont relativement bien décrits. A l’inverse, peu d’informations sur la réponse des plantes à un « excès » de fer sont disponibles. Dans ce contexte, une expérience visant à décrypter, au niveau du transcriptome (puces à ADN), la dynamique de la réponse précoce (de quelques minutes à 2 heures) à un excès de fer a été mise en place. Une analyse de variance a été réalisée sur les données d’expression générées afin d’identifier les gènes dont l’expression est affectée par le traitement. Nous nous sommes plus particulièrement focalisés sur l’identification de facteurs de transcription, acteurs majeurs du maintien de l’homéostasie du fer. Parmi eux, WRKY33, WRKY40, ZAT10 et MYB51, tous liés à la réponse au ROS, semblent avoir un rôle clé dans la réponse précoce au fer.D’autre part, un mécanisme clé de l’homéostasie du fer est le prélèvement. Une précédente étude a montré que la nutrition en fer était facilitée par la synthèse et la sécrétion de composés phénoliques via le transporteur PDR9. Une caractérisation des mutants pdr9 a permis d’établir que d’une part (i) ses composés pouvaient être stockés dans les vacuoles des cellules racinaires, et d’autre part (ii) qu’ils permettaient l’entrée de fer via le système de prélèvement gouverné par le mécanisme FRO2/IRT1.Mes travaux de thèse ont permis d’apporter des éléments nouveaux sur les mécanismes moléculaires et physiologiques impliqués dans le contrôle de l’homéostasie du fer chez Arabidopsis.]]></content:encoded>
    </item>
    <item>
      <title>[hal-01605402] Carbon monoxide pollution aggravates ischemic heart failure through oxidative stress pathway</title>
      <description><![CDATA[Risk of hospital readmission and cardiac mortality increases with atmospheric pollution for patients with heart failure. The underlying mechanisms are unclear. Carbon monoxide (CO) a ubiquitous environmental pollutant could be involved. We explored the effect of daily exposure of CO relevant to urban pollution on post-myocardial infarcted animals. Rats with ischemic heart failure were exposed 4 weeks to daily peaks of CO mimicking urban exposure or to standard filtered air. CO exposure worsened cardiac contractile dysfunction evaluated by echocardiography and at the cardiomyocyte level. In line with clinical reports, the animals exposed to CO also exhibited a severe arrhythmogenic phenotype with numerous sustained ventricular tachycardias as monitored by surface telemetric electrocardiograms. CO did not affect cardiac beta-adrenergic responsiveness. Instead, mitochondrial dysfunction was exacerbated leading to additional oxidative stress and Ca2+ cycling alterations. This was reversed following acute antioxidant treatment of cardiomyocytes with N-acetylcysteine confirming involvement of CO-induced oxidative stress. Exposure to daily peaks of CO pollution aggravated cardiac dysfunction in rats with ischemic heart failure by specifically targeting mitochondria and generating ROS-dependent alterations. This pathway may contribute to the high sensibility and vulnerability of individuals with cardiac disease to environmental outdoor air quality.]]></description>
      <pubDate>Wed, 27 Jun 2018 09:28:21 +0000</pubDate>
      <link>https://hal.archives-ouvertes.fr/hal-01605402</link>
      <guid>https://hal.archives-ouvertes.fr/hal-01605402</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Cyril Reboul)</author>
      <dc:creator>Cyril Reboul</dc:creator>
      <content:encoded><![CDATA[Risk of hospital readmission and cardiac mortality increases with atmospheric pollution for patients with heart failure. The underlying mechanisms are unclear. Carbon monoxide (CO) a ubiquitous environmental pollutant could be involved. We explored the effect of daily exposure of CO relevant to urban pollution on post-myocardial infarcted animals. Rats with ischemic heart failure were exposed 4 weeks to daily peaks of CO mimicking urban exposure or to standard filtered air. CO exposure worsened cardiac contractile dysfunction evaluated by echocardiography and at the cardiomyocyte level. In line with clinical reports, the animals exposed to CO also exhibited a severe arrhythmogenic phenotype with numerous sustained ventricular tachycardias as monitored by surface telemetric electrocardiograms. CO did not affect cardiac beta-adrenergic responsiveness. Instead, mitochondrial dysfunction was exacerbated leading to additional oxidative stress and Ca2+ cycling alterations. This was reversed following acute antioxidant treatment of cardiomyocytes with N-acetylcysteine confirming involvement of CO-induced oxidative stress. Exposure to daily peaks of CO pollution aggravated cardiac dysfunction in rats with ischemic heart failure by specifically targeting mitochondria and generating ROS-dependent alterations. This pathway may contribute to the high sensibility and vulnerability of individuals with cardiac disease to environmental outdoor air quality.]]></content:encoded>
    </item>
    <item>
      <title>[lirmm-01285152] Mutual information analysis: higher-order statistical moments, efficiency and efficacy</title>
      <description><![CDATA[The wide attention given to the Mutual Information Analysis (MIA) is often connected to its statistical genericity, denoted flexibility in this paper. Indeed , MIA is expected to lead to successful key recoveries with no reliance on a priori knowledge about the implementation (impacted by the error modeling made by the attacker. and with as minimum assumptions as possible about the leakage distribution (i.e. able to exploit information lying in any statistical moment and to detect all types of functional dependencies), up to the error modeling which impacts its efficiency (and even its effectiveness). However, emphasis is put on the powerful generality of the concept behind the MIA, as well as on the significance of adequate Probability Density Functions (PDF) estimation which seriously impacts its performance. By contrast to its theoretical advantages , MIA suffers from underperformance in practice limiting its usage. Considering that this underperfor-mance could be explained by suboptimal estimation procedures, we studied in-depth MIA by analyzing the link between the setting of tuning parameters involved in the commonly used nonparametric density estimation , namely Kernel Density Estimation (KDE) with respect to three criteria: the statistical moment where the leakage prevails, MIA's efficiency and its flexibility according to the classical Hamming weight model. The goal of this paper is therefore to cast some interesting light on the field of PDF estimation issues in MIA for which much work has been devoted to finding improved estimators having their pros and cons, while little attempt has been made to identify whether or not existing classical methods can be practically improved according to the degree of freedom offered by hyperpa-rameters (when available). We show that some 'opti-mal' estimation procedures following a problem-based approach rather than the systemic use of heuristics following a accuracy-based approach can make MIA more efficient and flexible and a practical guideline for tuning the hyperparameters involved in MIA should be designed. The results of this analysis allowed us defining a guideline based on a detailed comparison of MIA's results across various simulations and real-world datasets (including publicly available ones such as DPA contest V2 and V4.1).]]></description>
      <pubDate>Wed, 27 Jun 2018 09:00:37 +0000</pubDate>
      <link>https://hal-lirmm.ccsd.cnrs.fr/lirmm-01285152</link>
      <guid>https://hal-lirmm.ccsd.cnrs.fr/lirmm-01285152</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Mathieu Carbone)</author>
      <dc:creator>Mathieu Carbone</dc:creator>
      <content:encoded><![CDATA[The wide attention given to the Mutual Information Analysis (MIA) is often connected to its statistical genericity, denoted flexibility in this paper. Indeed , MIA is expected to lead to successful key recoveries with no reliance on a priori knowledge about the implementation (impacted by the error modeling made by the attacker. and with as minimum assumptions as possible about the leakage distribution (i.e. able to exploit information lying in any statistical moment and to detect all types of functional dependencies), up to the error modeling which impacts its efficiency (and even its effectiveness). However, emphasis is put on the powerful generality of the concept behind the MIA, as well as on the significance of adequate Probability Density Functions (PDF) estimation which seriously impacts its performance. By contrast to its theoretical advantages , MIA suffers from underperformance in practice limiting its usage. Considering that this underperfor-mance could be explained by suboptimal estimation procedures, we studied in-depth MIA by analyzing the link between the setting of tuning parameters involved in the commonly used nonparametric density estimation , namely Kernel Density Estimation (KDE) with respect to three criteria: the statistical moment where the leakage prevails, MIA's efficiency and its flexibility according to the classical Hamming weight model. The goal of this paper is therefore to cast some interesting light on the field of PDF estimation issues in MIA for which much work has been devoted to finding improved estimators having their pros and cons, while little attempt has been made to identify whether or not existing classical methods can be practically improved according to the degree of freedom offered by hyperpa-rameters (when available). We show that some 'opti-mal' estimation procedures following a problem-based approach rather than the systemic use of heuristics following a accuracy-based approach can make MIA more efficient and flexible and a practical guideline for tuning the hyperparameters involved in MIA should be designed. The results of this analysis allowed us defining a guideline based on a detailed comparison of MIA's results across various simulations and real-world datasets (including publicly available ones such as DPA contest V2 and V4.1).]]></content:encoded>
    </item>
    <item>
      <title>[hal-01516082] Scientific workflows for computational reproducibility in the life sciences: Status, challenges and opportunities</title>
      <description><![CDATA[With the development of new experimental technologies, biologists are faced with an avalanche of data to be computationally analyzed for scientific advancements and discoveries to emerge. Faced with the complexity of analysis pipelines, the large number of computational tools, and the enormous amount of data to manage, there is compelling evidence that many if not most scientific discoveries will not stand the test of time: increasing the reproducibility of computed results is of paramount importance. The objective we set out in this paper is to place scientific workflows in the context of reproducibility. To do so, we define several kinds of repro-ducibility that can be reached when scientific workflows are used to perform experiments. We characterize and define the criteria that need to be catered for by reproducibility-friendly scientific workflow systems, and use such criteria to place several representative and widely used workflow systems and companion tools within such a framework. We also discuss the remaining challenges posed by reproducible scientific workflows in the life sciences. Our study was guided by three use cases from the life science domain involving in silico experiments.]]></description>
      <pubDate>Wed, 27 Jun 2018 08:24:02 +0000</pubDate>
      <link>https://hal.archives-ouvertes.fr/hal-01516082</link>
      <guid>https://hal.archives-ouvertes.fr/hal-01516082</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Sarah Cohen-Boulakia)</author>
      <dc:creator>Sarah Cohen-Boulakia</dc:creator>
      <content:encoded><![CDATA[With the development of new experimental technologies, biologists are faced with an avalanche of data to be computationally analyzed for scientific advancements and discoveries to emerge. Faced with the complexity of analysis pipelines, the large number of computational tools, and the enormous amount of data to manage, there is compelling evidence that many if not most scientific discoveries will not stand the test of time: increasing the reproducibility of computed results is of paramount importance. The objective we set out in this paper is to place scientific workflows in the context of reproducibility. To do so, we define several kinds of repro-ducibility that can be reached when scientific workflows are used to perform experiments. We characterize and define the criteria that need to be catered for by reproducibility-friendly scientific workflow systems, and use such criteria to place several representative and widely used workflow systems and companion tools within such a framework. We also discuss the remaining challenges posed by reproducible scientific workflows in the life sciences. Our study was guided by three use cases from the life science domain involving in silico experiments.]]></content:encoded>
    </item>
    <item>
      <title>[hal-01629188] Analysis of an optimal control problem related to anaerobic digestion process</title>
      <description><![CDATA[Our aim in this work is to synthesize optimal feeding strategies maximizing over a time period the biogas production in a continuously filled bioreactor controlled by its dilution rate. Following [5], such an anaerobic process is described by the so-called AM2 model which is a four-dimensional dynamical system. Instead of modeling the optimization of the biogas production as an optimal control problem of Lagrange type, we propose in this paper a slightly different optimal control approach : we study the minimal time control problem to reach a target point which is chosen in such a way that it maximizes the biogas production in the AM2 model at steady state. Thanks to the Pontryagin Maximum Principle and to geometric control theory, we provide an optimal feedback control for the minimal time control problem when initial conditions are taken on the invariant and attractive manifold of the system. The optimal synthesis exhibits turnpike and anti-turnpike singular arcs and a cut-locus.]]></description>
      <pubDate>Wed, 27 Jun 2018 08:12:05 +0000</pubDate>
      <link>https://hal.archives-ouvertes.fr/hal-01629188v2</link>
      <guid>https://hal.archives-ouvertes.fr/hal-01629188v2</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Térence Bayen)</author>
      <dc:creator>Térence Bayen</dc:creator>
      <content:encoded><![CDATA[Our aim in this work is to synthesize optimal feeding strategies maximizing over a time period the biogas production in a continuously filled bioreactor controlled by its dilution rate. Following [5], such an anaerobic process is described by the so-called AM2 model which is a four-dimensional dynamical system. Instead of modeling the optimization of the biogas production as an optimal control problem of Lagrange type, we propose in this paper a slightly different optimal control approach : we study the minimal time control problem to reach a target point which is chosen in such a way that it maximizes the biogas production in the AM2 model at steady state. Thanks to the Pontryagin Maximum Principle and to geometric control theory, we provide an optimal feedback control for the minimal time control problem when initial conditions are taken on the invariant and attractive manifold of the system. The optimal synthesis exhibits turnpike and anti-turnpike singular arcs and a cut-locus.]]></content:encoded>
    </item>
    <item>
      <title>[lirmm-01419132] Embedded memory hierarchy exploration based on magnetic RAM</title>
      <description><![CDATA[SRAM, DRAM and FLASH are the three main employed technologies in design of on-chip processor memories. However, manufacturing constraints for this technologies in the most advanced nodes compromises further evolution. MRAM (Magnetic memory) presents itself as an attractive alternative for these technologies, as it has reasonable timing and power characteristics. Last results in the state of the art demonstrate that MRAM access time is can be less than 5ns and read/write energy per bit in same order of magnitude as SRAM, also it can evolve with the manufacturing process. One important feature of MRAM is the non-volatility, allowing to define new instant on/off policies and mainly optimizing leakage current. In this paper we demonstrate how MRAM can be used into memory hierarchy of embedded systems. The main objective is to demonstrate the interest to use MRAM for Level-1 &amp; 2 cache and to better understand the architectural choice in order to minimize the impact of the higher write latency of MRAMs.]]></description>
      <pubDate>Wed, 27 Jun 2018 01:23:54 +0000</pubDate>
      <link>https://hal-lirmm.ccsd.cnrs.fr/lirmm-01419132</link>
      <guid>https://hal-lirmm.ccsd.cnrs.fr/lirmm-01419132</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Luís Vitório Cargnini)</author>
      <dc:creator>Luís Vitório Cargnini</dc:creator>
      <content:encoded><![CDATA[SRAM, DRAM and FLASH are the three main employed technologies in design of on-chip processor memories. However, manufacturing constraints for this technologies in the most advanced nodes compromises further evolution. MRAM (Magnetic memory) presents itself as an attractive alternative for these technologies, as it has reasonable timing and power characteristics. Last results in the state of the art demonstrate that MRAM access time is can be less than 5ns and read/write energy per bit in same order of magnitude as SRAM, also it can evolve with the manufacturing process. One important feature of MRAM is the non-volatility, allowing to define new instant on/off policies and mainly optimizing leakage current. In this paper we demonstrate how MRAM can be used into memory hierarchy of embedded systems. The main objective is to demonstrate the interest to use MRAM for Level-1 &amp; 2 cache and to better understand the architectural choice in order to minimize the impact of the higher write latency of MRAMs.]]></content:encoded>
    </item>
    <item>
      <title>[lirmm-01421006] Methodology for Power Mode selection in FD-SOI circuits with DVFS and Dynamic Body Biasing</title>
      <description><![CDATA[Embedded systems need ever increasing computational performances. Since they have limited energy resources, power consumption has to be minimized. Dynamic Voltage and Frequency Scaling (DVFS) techniques combined with Body Biasing techniques decrease the power consumption of a chip by providing just enough computational performance to the chip so as to finish the task at its deadline. A Power Mode (PM) is defined with the clock frequency F applied to the chip and the power P consumed by the chip. Executing tasks with the 2 neighbor frequencies of the target frequency should minimize the power consumption. Unfortunately, this choice is not always optimal since the set of available PMs may not fulfil the convexity property anymore when 3 actuators are considered. Here, a method is proposed to tackle this issue. PMs are selected to form a discretely convex subset. Results for a ring oscillator in FD-SOI exemplify that the proposed approach can save power consumption.]]></description>
      <pubDate>Wed, 27 Jun 2018 01:23:54 +0000</pubDate>
      <link>https://hal-lirmm.ccsd.cnrs.fr/lirmm-01421006</link>
      <guid>https://hal-lirmm.ccsd.cnrs.fr/lirmm-01421006</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Yeter Akgul)</author>
      <dc:creator>Yeter Akgul</dc:creator>
      <content:encoded><![CDATA[Embedded systems need ever increasing computational performances. Since they have limited energy resources, power consumption has to be minimized. Dynamic Voltage and Frequency Scaling (DVFS) techniques combined with Body Biasing techniques decrease the power consumption of a chip by providing just enough computational performance to the chip so as to finish the task at its deadline. A Power Mode (PM) is defined with the clock frequency F applied to the chip and the power P consumed by the chip. Executing tasks with the 2 neighbor frequencies of the target frequency should minimize the power consumption. Unfortunately, this choice is not always optimal since the set of available PMs may not fulfil the convexity property anymore when 3 actuators are considered. Here, a method is proposed to tackle this issue. PMs are selected to form a discretely convex subset. Results for a ring oscillator in FD-SOI exemplify that the proposed approach can save power consumption.]]></content:encoded>
    </item>
    <item>
      <title>[hal-00824225] Autonomic Management of Reconfigurable Embedded Systems using Discrete Control: Application to FPGA</title>
      <description><![CDATA[This paper targets the autonomic management of dynamically partially reconfigurable hardware architectures based on FPGAs. Such hardware-level autonomic computing has been less often studied than at software-level. We consider control techniques to model the considered behaviours of the computing system and derive a controller for the control objective enforcement. Discrete Control modelled with Labelled Transition Systems is employed in this paper. Such models are amenable to Discrete Controller Synthesis algorithms that can automatically generate a controller enforcing the correct behaviours of a controlled system. A general modelling framework is proposed for the control of FPGA based computing systems. We consider system application described as task graphs and FPGA as a set of reconfigurable areas that can be dynamically partially reconfigured to execute tasks. We encode the computation of an autonomic manager as a DCS problem w.r.t. multiple constraints and objectives e.g., mutual exclusion of resource uses, power cost minimization. We validate our models and manager computations by using the BZR language and an experimental demonstrator implemented on a Xilinx FPGA platform.]]></description>
      <pubDate>Wed, 27 Jun 2018 01:23:54 +0000</pubDate>
      <link>https://hal.inria.fr/hal-00824225v3</link>
      <guid>https://hal.inria.fr/hal-00824225v3</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Xin An)</author>
      <dc:creator>Xin An</dc:creator>
      <content:encoded><![CDATA[This paper targets the autonomic management of dynamically partially reconfigurable hardware architectures based on FPGAs. Such hardware-level autonomic computing has been less often studied than at software-level. We consider control techniques to model the considered behaviours of the computing system and derive a controller for the control objective enforcement. Discrete Control modelled with Labelled Transition Systems is employed in this paper. Such models are amenable to Discrete Controller Synthesis algorithms that can automatically generate a controller enforcing the correct behaviours of a controlled system. A general modelling framework is proposed for the control of FPGA based computing systems. We consider system application described as task graphs and FPGA as a set of reconfigurable areas that can be dynamically partially reconfigured to execute tasks. We encode the computation of an autonomic manager as a DCS problem w.r.t. multiple constraints and objectives e.g., mutual exclusion of resource uses, power cost minimization. We validate our models and manager computations by using the BZR language and an experimental demonstrator implemented on a Xilinx FPGA platform.]]></content:encoded>
    </item>
    <item>
      <title>[lirmm-00985447] Using electromagnetic emanations for variability characterization in Flash-based FPGAs</title>
      <description><![CDATA[An ElectroMagnetic analysis (EMA) technique is applied to Flash-based FPGA (Field Programmable Gate Arrays) ProASIC3E to measure the delay variability. Measurements show that delay variations can reach 40% according to the mapping, placement and routing used in the FPGA array, while the synthesis tool analysis show differences lower than 7%. Comparisons between the use of EMA technique in Flash and SRAM-based FPGAs are presented. The Flash-based FPGA configurable blocks and routing structures are modeled at the electrical level. Then, SPICE simulations are performed to compare the predictive variability to the measurements ones. Results obtained with EMA can support designers on selecting different parts of the FPGA array, such as distinct mapping, placements and routing wires according to application and provide a valuable feedback for the FPGA's manufacture company.]]></description>
      <pubDate>Wed, 27 Jun 2018 01:23:54 +0000</pubDate>
      <link>https://hal-lirmm.ccsd.cnrs.fr/lirmm-00985447</link>
      <guid>https://hal-lirmm.ccsd.cnrs.fr/lirmm-00985447</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Florent Bruguier)</author>
      <dc:creator>Florent Bruguier</dc:creator>
      <content:encoded><![CDATA[An ElectroMagnetic analysis (EMA) technique is applied to Flash-based FPGA (Field Programmable Gate Arrays) ProASIC3E to measure the delay variability. Measurements show that delay variations can reach 40% according to the mapping, placement and routing used in the FPGA array, while the synthesis tool analysis show differences lower than 7%. Comparisons between the use of EMA technique in Flash and SRAM-based FPGAs are presented. The Flash-based FPGA configurable blocks and routing structures are modeled at the electrical level. Then, SPICE simulations are performed to compare the predictive variability to the measurements ones. Results obtained with EMA can support designers on selecting different parts of the FPGA array, such as distinct mapping, placements and routing wires according to application and provide a valuable feedback for the FPGA's manufacture company.]]></content:encoded>
    </item>
    <item>
      <title>[lirmm-01096070] Practical Analysis of RSA Countermeasures Against Side-Channel Electromagnetic Attacks</title>
      <description><![CDATA[This paper analyzes the robustness of RSA countermeasures against electromagnetic analysis and collision attacks. The proposed RSA cryptosystem uses residue number systems (RNS) for fast executions of the modular calculi with large numbers. The parallel architecture is protected at arithmetic and algorithmic levels by using the Montgomery Ladder and the Leak Resistant Arithmetic countermeasures. Because the architecture can leak information through control and memory executions, the hardware RNS-RSA also relies on the randomization of RAM accesses. Experimental results, obtained with and without randomization of the RNS moduli sets, suggest that the RNS-based RSA with bases randomization and secured RAM accesses is protected.]]></description>
      <pubDate>Wed, 27 Jun 2018 01:23:54 +0000</pubDate>
      <link>https://hal-lirmm.ccsd.cnrs.fr/lirmm-01096070</link>
      <guid>https://hal-lirmm.ccsd.cnrs.fr/lirmm-01096070</guid>
      <author>ano.nymous@ccsd.cnrs.fr.invalid (Guilherme Perin)</author>
      <dc:creator>Guilherme Perin</dc:creator>
      <content:encoded><![CDATA[This paper analyzes the robustness of RSA countermeasures against electromagnetic analysis and collision attacks. The proposed RSA cryptosystem uses residue number systems (RNS) for fast executions of the modular calculi with large numbers. The parallel architecture is protected at arithmetic and algorithmic levels by using the Montgomery Ladder and the Leak Resistant Arithmetic countermeasures. Because the architecture can leak information through control and memory executions, the hardware RNS-RSA also relies on the randomization of RAM accesses. Experimental results, obtained with and without randomization of the RNS moduli sets, suggest that the RNS-based RSA with bases randomization and secured RAM accesses is protected.]]></content:encoded>
    </item>
  </channel>
</rss>
