32 research outputs found

    Constraint-based probabilistic learning of metabolic pathways from tomato volatiles

    Get PDF
    Clustering and correlation analysis techniques have become popular tools for the analysis of data produced by metabolomics experiments. The results obtained from these approaches provide an overview of the interactions between objects of interest. Often in these experiments, one is more interested in information about the nature of these relationships, e.g., cause-effect relationships, than in the actual strength of the interactions. Finding such relationships is of crucial importance as most biological processes can only be understood in this way. Bayesian networks allow representation of these cause-effect relationships among variables of interest in terms of whether and how they influence each other given that a third, possibly empty, group of variables is known. This technique also allows the incorporation of prior knowledge as established from the literature or from biologists. The representation as a directed graph of these relationship is highly intuitive and helps to understand these processes. This paper describes how constraint-based Bayesian networks can be applied to metabolomics data and can be used to uncover the important pathways which play a significant role in the ripening of fresh tomatoes. We also show here how this methods of reconstructing pathways is intuitive and performs better than classical techniques. Methods for learning Bayesian network models are powerful tools for the analysis of data of the magnitude as generated by metabolomics experiments. It allows one to model cause-effect relationships and helps in understanding the underlying processes

    Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

    Get PDF
    The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference

    Pauvreté, (non-) recours aux droits sociaux et représentations sociales

    Full text link
    More and more, French society is faced with the necessity and/or possibility to resort to the social welfare system because of increasing social inequality and poverty. At the same time, an opposing phenomenon baffles authorities: no take-up of social rights (Warin, 2010). Our doctoral thesis focused on understanding this phenomenon in relation to poverty, from the perspective of social representations (Moscovici, 2013; Jodelet, 2015). Through methodological triangulation (Apostolidis, 2006), combining qualitative and quantitative methods, we observed and collected social representations that describe, explain and organize these legal practices and what makes them difficult.Several themata in particular contribute to the interpretation of experiences and guide action. First, the complex-simple themata describes and explains legal practices, referring to the objectification process specific to the operation of social thought. The simplification of access to rights and their familiarization, which are necessary to be able to benefit from them, are possible because of knowledge gained through the experience of poverty and law, and through shared experiential, scholarly, cultural and expert knowledge.These experiences also bring out the strength-weakness themata. As a social virtue linked to courage and will-power, strength prevents weakness, which is associated with collapse and “letting oneself go”, and helps to cope with socioeconomic difficulties and accessing social rights. Paradoxically, weakness is also a way to be recognized legally, putting pressure on the search for recognition. Hence, both aspects of the anchoring process are present simultaneously: recognition and stigmatization.These experiences also fit into the social representations of Justice and into dynamics of loyalty or defiance regarding law and instituted justice. Hence, they shape different uses of the social welfare system and contribute to weakening the social representations of justice. We show that the latter are part of the donation/counter-donation exchange and take different forms depending on who is identified as the donor and the recipient.Finally, through these three themata (simple-complex, weakness-strength, justice-injustice) and in social contexts, we highlighted the pervasiveness of social representations that organize individuals’ experiences, views of the world and of themselves, their reliance on social benefits and their social participations. In each themata, the issue of recognition (symbolization) and non-recognition (stigmatization) structures the social representations and practices of relatively poor subjects who benefit from social welfare rights.Une part de plus en plus importante de la sociĂ©tĂ© française est confrontĂ©e Ă  la nĂ©cessitĂ© et/ou Ă  la possibilitĂ© de recourir au systĂšme de protection sociale du fait de l’augmentation des inĂ©galitĂ©s sociales et des situations de pauvretĂ©. ParallĂšlement, un phĂ©nomĂšne antinomique interroge les pouvoirs publics : le non-recours aux droits sociaux (Warin, 2010). Notre thĂšse de doctorat s’est focalisĂ©e sur la comprĂ©hension de ce phĂ©nomĂšne en lien avec celui de la pauvretĂ©, du point de vue de la psychologie des reprĂ©sentations sociales (Moscovici, 2013 ; Jodelet, 2015). Une dĂ©marche de triangulation mĂ©thodologique (Apostolidis, 2006), mĂȘlant mĂ©thodes qualitatives et quantitatives, nous a permis d’observer et de recueillir en contextes les reprĂ©sentations sociales dĂ©crivant, expliquant et organisant ces pratiques de droit et ce qui les rend difficiles. Plusieurs thĂȘmata participent particuliĂšrement Ă  l’interprĂ©tation des expĂ©riences vĂ©cues et Ă  l’orientation des actions. D’abord le thĂȘmata complexe-simple permet de dĂ©crire et d’expliquer les pratiques de droits, renvoyant au processus d’objectivation propre au fonctionnement de la pensĂ©e sociale. La simplification de l’accĂšs aux droits et sa familiarisation, nĂ©cessaire aux recours, sont rendues possibles grĂące aux savoirs acquis dans l’expĂ©rience passĂ©e de la pauvretĂ© et du droit, et grĂące aux autres partageant leurs savoirs expĂ©rientiels, scolaires, culturels et experts. Ces expĂ©riences vĂ©cues font aussi Ă©merger le thĂȘmata force-faiblesse. La force comme vertu sociale, liĂ©e au courage et Ă  la volontĂ©, permet de ne pas faiblir, associĂ© l’image de la chute et des corps qui se « laissent aller », et de s’activer pour faire face aux difficultĂ©s socio-Ă©conomiques et d’accĂšs aux droits. Mais la faiblesse apparaĂźt paradoxalement comme un moyen d’ĂȘtre reconnu dans la sphĂšre du droit, mettant en tension la demande de reconnaissance. Cette demande fait cohabiter simultanĂ©ment les deux mouvements caractĂ©risant le processus d’ancrage : la reconnaissance et la stigmatisation. Ces expĂ©riences vĂ©cues s’inscrivent encore dans les reprĂ©sentations sociales de la justice et dans des rapports d’allĂ©geance ou de dĂ©fiance envers le droit et la justice instituĂ©e, façonnant des usages diffĂ©renciĂ©s du systĂšme de protection sociale et des formes de fragilisation des reprĂ©sentations sociales de la justice. Nous montrons que ces derniĂšres s’inscrivent dans l’échange don/contre-don et façonnent diffĂ©remment le recours en fonction de qui est identifiĂ© comme donateur et donataire. Finalement, Ă  travers ces trois thĂȘmata (simple-complexe, force-faiblesse, justice-injustice) nous avons montrĂ© la prĂ©gnance, dans ces contextes sociaux, de reprĂ©sentations sociales totales autour desquelles s’organise l’expĂ©rience des sujets, leur rapport au monde et Ă  eux-mĂȘmes, leurs recours aux droits sociaux et leurs participations sociales. A travers chacun de ces thĂȘmata se joue l’enjeu de la reconnaissance (symbolisation) ou de la non-reconnaissance (stigmatisation) structurant l’ensemble de la construction des reprĂ©sentations et des pratiques sociales des sujets sociaux recourant aux droits sociaux en situation de pauvretĂ© relative

    Poverty, (no) take-up of social rights and social representation

    Full text link
    Une part de plus en plus importante de la sociĂ©tĂ© française est confrontĂ©e Ă  la nĂ©cessitĂ© et/ou Ă  la possibilitĂ© de recourir au systĂšme de protection sociale du fait de l’augmentation des inĂ©galitĂ©s sociales et des situations de pauvretĂ©. ParallĂšlement, un phĂ©nomĂšne antinomique interroge les pouvoirs publics : le non-recours aux droits sociaux (Warin, 2010). Notre thĂšse de doctorat s’est focalisĂ©e sur la comprĂ©hension de ce phĂ©nomĂšne en lien avec celui de la pauvretĂ©, du point de vue de la psychologie des reprĂ©sentations sociales (Moscovici, 2013 ; Jodelet, 2015). Une dĂ©marche de triangulation mĂ©thodologique (Apostolidis, 2006), mĂȘlant mĂ©thodes qualitatives et quantitatives, nous a permis d’observer et de recueillir en contextes les reprĂ©sentations sociales dĂ©crivant, expliquant et organisant ces pratiques de droit et ce qui les rend difficiles. Plusieurs thĂȘmata participent particuliĂšrement Ă  l’interprĂ©tation des expĂ©riences vĂ©cues et Ă  l’orientation des actions. D’abord le thĂȘmata complexe-simple permet de dĂ©crire et d’expliquer les pratiques de droits, renvoyant au processus d’objectivation propre au fonctionnement de la pensĂ©e sociale. La simplification de l’accĂšs aux droits et sa familiarisation, nĂ©cessaire aux recours, sont rendues possibles grĂące aux savoirs acquis dans l’expĂ©rience passĂ©e de la pauvretĂ© et du droit, et grĂące aux autres partageant leurs savoirs expĂ©rientiels, scolaires, culturels et experts. Ces expĂ©riences vĂ©cues font aussi Ă©merger le thĂȘmata force-faiblesse. La force comme vertu sociale, liĂ©e au courage et Ă  la volontĂ©, permet de ne pas faiblir, associĂ© l’image de la chute et des corps qui se « laissent aller », et de s’activer pour faire face aux difficultĂ©s socio-Ă©conomiques et d’accĂšs aux droits. Mais la faiblesse apparaĂźt paradoxalement comme un moyen d’ĂȘtre reconnu dans la sphĂšre du droit, mettant en tension la demande de reconnaissance. Cette demande fait cohabiter simultanĂ©ment les deux mouvements caractĂ©risant le processus d’ancrage : la reconnaissance et la stigmatisation. Ces expĂ©riences vĂ©cues s’inscrivent encore dans les reprĂ©sentations sociales de la justice et dans des rapports d’allĂ©geance ou de dĂ©fiance envers le droit et la justice instituĂ©e, façonnant des usages diffĂ©renciĂ©s du systĂšme de protection sociale et des formes de fragilisation des reprĂ©sentations sociales de la justice. Nous montrons que ces derniĂšres s’inscrivent dans l’échange don/contre-don et façonnent diffĂ©remment le recours en fonction de qui est identifiĂ© comme donateur et donataire. Finalement, Ă  travers ces trois thĂȘmata (simple-complexe, force-faiblesse, justice-injustice) nous avons montrĂ© la prĂ©gnance, dans ces contextes sociaux, de reprĂ©sentations sociales totales autour desquelles s’organise l’expĂ©rience des sujets, leur rapport au monde et Ă  eux-mĂȘmes, leurs recours aux droits sociaux et leurs participations sociales. A travers chacun de ces thĂȘmata se joue l’enjeu de la reconnaissance (symbolisation) ou de la non-reconnaissance (stigmatisation) structurant l’ensemble de la construction des reprĂ©sentations et des pratiques sociales des sujets sociaux recourant aux droits sociaux en situation de pauvretĂ© relative.More and more, French society is faced with the necessity and/or possibility to resort to the social welfare system because of increasing social inequality and poverty. At the same time, an opposing phenomenon baffles authorities: no take-up of social rights (Warin, 2010). Our doctoral thesis focused on understanding this phenomenon in relation to poverty, from the perspective of social representations (Moscovici, 2013; Jodelet, 2015). Through methodological triangulation (Apostolidis, 2006), combining qualitative and quantitative methods, we observed and collected social representations that describe, explain and organize these legal practices and what makes them difficult.Several themata in particular contribute to the interpretation of experiences and guide action. First, the complex-simple themata describes and explains legal practices, referring to the objectification process specific to the operation of social thought. The simplification of access to rights and their familiarization, which are necessary to be able to benefit from them, are possible because of knowledge gained through the experience of poverty and law, and through shared experiential, scholarly, cultural and expert knowledge.These experiences also bring out the strength-weakness themata. As a social virtue linked to courage and will-power, strength prevents weakness, which is associated with collapse and “letting oneself go”, and helps to cope with socioeconomic difficulties and accessing social rights. Paradoxically, weakness is also a way to be recognized legally, putting pressure on the search for recognition. Hence, both aspects of the anchoring process are present simultaneously: recognition and stigmatization.These experiences also fit into the social representations of Justice and into dynamics of loyalty or defiance regarding law and instituted justice. Hence, they shape different uses of the social welfare system and contribute to weakening the social representations of justice. We show that the latter are part of the donation/counter-donation exchange and take different forms depending on who is identified as the donor and the recipient.Finally, through these three themata (simple-complex, weakness-strength, justice-injustice) and in social contexts, we highlighted the pervasiveness of social representations that organize individuals’ experiences, views of the world and of themselves, their reliance on social benefits and their social participations. In each themata, the issue of recognition (symbolization) and non-recognition (stigmatization) structures the social representations and practices of relatively poor subjects who benefit from social welfare rights

    Ressentis stigmatiques et résistances de certains jeunes hommes « indésirables »

    Full text link
    In this article, we look at a urban renewal program, targeting social diversity in public housing neighborhoods. We explore the impact of these types of programs. The analysis focuses on the socio-spatial attributions and also on the feelings of young men, often seen as “undesirables” - a perception shared by a lot of policymakers and inhabitants. These young men carrying a sense of inequity, are driven through resignation, accusation, fatalism, and call-out to officials. They experience a conflicting relationship to physical and social spaces, traditionally gendered and ruffled by urban renewal - cafĂ©, food shops, building hallway, new limited-access equipments, or old equipments. Facing this tangible ostracization, new re-categorization strategies appear also among old-comers inhabitants.Cet article explore les effets d’une rĂ©novation urbaine visant la mixitĂ© sociale dans un quartier d’habitat social sur l’assignation sociospatiale et les ressentis de jeunes hommes perçus comme « indĂ©sirables » par nombre de dĂ©cideurs politiques et d’habitants. Oscillant entre rĂ©signation et dĂ©nonciation, fatalisme et interpellation, les ressentis d’injustice – par inĂ©quitĂ© – de ces jeunes hommes s’expriment dans leurs rapports contrariĂ©s aux espaces physiques et sociaux classiquement genrĂ©s et bousculĂ©s par le renouvellement urbain : cafĂ©s et commerces de bouche, halls d’immeubles, nouvel Ă©quipement en accĂšs restreint ou encore anciens Ă©quipements en perte de centralitĂ©. Face Ă  cette ostracisation perçue, des modes de recatĂ©gorisation stratĂ©giques s’opĂšrent aussi chez des habitants « dĂ©jĂ -lĂ  ».Vinet Élise, Cadel Cynthia, Beal Arnaud. Ressentis stigmatiques et rĂ©sistances de certains jeunes hommes « indĂ©sirables ». In: Les Annales de la recherche urbaine, N°112, 2017. Le genre urbain. pp. 60-71
    corecore