Le récit littéraire comme savoir alternatif : l’expérience magnétique dans "Louis Lambert", "Avatar" et "Claire Lenoir"

Cet article s’intéresse à la mise en texte des théories magnétiques, à partir de trois œuvres de Balzac, Gautier et Villiers. L’enjeu est de montrer que ces récits, qui semblent faire la part belle aux exposés théoriques, proposent en réalité une véritable mise en fiction des savoirs qu’ils exhibent. Par des procédés proprement littéraires (la spécularité, l’intertextualité, l’ironie), ces récits magnétiques mettent en place un savoir des correspondances proprement littéraire, lui-même alternatif, à l’image du magnétisme, mais en dépit de son armature théorique

Naissance du fantastique clinique

Cet ouvrage porte sur le lien entre « imaginaire clinique » et « fantastique fin-de-siècle ». Il s’agit, notamment à partir de la définition que donne Michel Foucault de la clinique, de relire un certain nombre d’œuvres fantastiques de la fin du siècle (Maupassant, Lorrain, Lermina, Villiers, mais aussi Zola), en interrogeant ce qui permet de les cataloguer comme « fantastiques », dès lors qu’elles utilisent des thèmes et des ressorts relevant de la clinique. L’interrogation qui sous-tend une telle démarche est donc celle de la spécificité de l’optique fantastique par rapport à l’esthétique réaliste, qui puise abondamment dans la clinique pour y trouver une méthode, un objet (la pathologie), et un système d’explication. L’hypothèse avancée est alors que le fantastique fin-de-siècle relève, justement, d’une optique (ce qu’Edmond Picard appelle le « fantastique réel »), mais d’une optique très différente de celle qu’a étudiée Max Milner ("La Fantasmagorie") à propos du fantastique romantique du début du siècle. L’analyse de cette optique dégage ensuite un certain nombre de principes poétiques issus de la clinique, comme le principe de Broussais (la continuité du normal et du pathologique), le principe de Baillarger (la pathologie comme conséquence d’un déséquilibre entre volontaire et involontaire), et le rôle de l’analyse (qui n’est plus un principe herméneutique, comme dans la clinique, mais un principe morbide de déliaison, voire d’aliénation). Le corpus analysé fait dialoguer textes célèbres et moins connus, en relation avec les faits divers et les « cas » ayant défrayé la chronique à la fin du siècle. Il fait également une large place à l’influence d’Edgar Poe, ou plus exactement à sa réception « clinique » par les écrivains de la fin du siècle (son démon de la perversité est perçu comme une « trouvaille cérébrale adéquate à un rapport de médecin légiste »). Chaque partie est construite autour de l’analyse d’un « cas » littéraire emblématique (le « fantastique dans l’étude du vrai » de "La Faustin" d’Edmond de Goncourt ; « l’expérience » cérébrale qui ouvre "Le Grand Dieu Pan" d’Arthur Machen ; le « démon de l’examen » mis en œuvre dans "La Deux fois morte" de Jules Lermina, version fin-de-siècle du « démon de la perversité »)

Alteration of pathogenicity-linked life-history traits by resistance of its host Solanum tuberosum impacts sexual reproduction of the plant pathogenic oomycete Phytophthora infestans.

International audienceAlthough sexual reproduction implies a cost, it represents an evolutionary advantage for the adaptation and survival of facultative sexual pathogens. Understanding the maintenance of sex in pathogens requires to analyse how host resistance will impact their sexual reproduction through the alteration of their life-history traits. We explored this experimentally using potato (Solanum tuberosum) and one of its pathogens, the heterothallic oomycete Phytophthora infestans. Sexual reproduction was highest on hosts favouring asexual multiplication of the pathogen, suggesting similar nutritional requirements for both sexual and asexual sporulation. Sexual reproduction was also highest on hosts decreasing the latent period, probably because of a trade-off between growth and reproduction. Distinguishing host effects on each pathogenic trait remains however uneasy, as most life-history traits linked to pathogenicity were not independent of each other. We argue that sexual reproduction of P. infestans is an adaptation to survive when the host is susceptible and rapidly destroyed

Modeling past human-induced vegetation change is a challenge – the case of Europe

Differences between pollen-based reconstructions and dynamic vegetation simulations of past vegetation change in Europe over the last seven millennia are interpreted as being due primarily to land-use change. Incorporating land use in climate and dynamic vegetation models requires new approaches

Tectonic interleaving along the Main Central Thrust, Sikkim Himalaya

Geochemical and geochronological analyses provide quantitative evidence about the origin, development and motion along ductile faults, where kinematic structures have been overprinted. The Main Central Thrust is a key structure in the Himalaya that accommodated substantial amounts of the India–Asia convergence. This structure juxtaposes two isotopically distinct rock packages across a zone of ductile deformation. Structural analysis, whole-rock Nd isotopes, and U–Pb zircon geochronology reveal that the hanging wall is characterized by detrital zircon peaks at c. 800–1000 Ma, 1500–1700 Ma and 2300–2500 Ma and an εNd(0) signature of –18.3 to –12.1, and is intruded by c. 800 Ma and c. 500–600 Ma granites. In contrast, the footwall has a prominent detrital zircon peak at c. 1800–1900 Ma, with older populations spanning 1900–3600 Ma, and an εNd(0) signature of –27.7 to –23.4, intruded by c. 1830 Ma granites. The data reveal a c. 5 km thick zone of tectonic imbrication, where isotopically out-of-sequence packages are interleaved. The rocks became imbricated as the once proximal and distal rocks of the Indian margin were juxtaposed by Cenozoic movement along the Main Central Thrust. Geochronological and isotopic characterization allows for correlation along the Himalayan orogen and could be applied to other cryptic ductile shear zones

Europe's lost forests: a pollen-based synthesis for the last 11,000 years

8000 years ago, prior to Neolithic agriculture, Europe was mostly a wooded continent. Since then, its forest cover has been progressively fragmented, so that today it covers less than half of Europe’s land area, in many cases having been cleared to make way for fields and pasture-land. Establishing the origin of Europe’s current, more open land-cover mosaic requires a long-term perspective, for which pollen analysis offers a key tool. In this study we utilise and compare three numerical approaches to transforming pollen data into past forest cover, drawing on >1000 14C-dated site records. All reconstructions highlight the different histories of the mixed temperate and the northern boreal forests, with the former declining progressively since ~6000 years ago, linked to forest clearance for agriculture in later prehistory (especially in northwest Europe) and early historic times (e.g. in north central Europe). In contrast, extensive human impact on the needle-leaf forests of northern Europe only becomes detectable in the last two millennia and has left a larger area of forest in place. Forest loss has been a dominant feature of Europe’s landscape ecology in the second half of the current interglacial, with consequences for carbon cycling, ecosystem functioning and biodiversity

Pollen-based quantitative reconstructions of Holocene regional vegetation cover (plant-functional types and land-cover types) in Europe suitable for climate modelling

We present quantitative reconstructions of regional vegetation cover in north-western Europe, western Europe north of the Alps, and eastern Europe for five time windows in the Holocene [around 6k, 3k, 0.5k, 0.2k, and 0.05k calendar years before present (bp)] at a 1 degrees x1 degrees spatial scale with the objective of producing vegetation descriptions suitable for climate modelling. The REVEALS model was applied on 636 pollen records from lakes and bogs to reconstruct the past cover of 25 plant taxa grouped into 10 plant-functional types and three land-cover types [evergreen trees, summer-green (deciduous) trees, and open land]. The model corrects for some of the biases in pollen percentages by using pollen productivity estimates and fall speeds of pollen, and by applying simple but robust models of pollen dispersal and deposition. The emerging patterns of tree migration and deforestation between 6k bp and modern time in the REVEALS estimates agree with our general understanding of the vegetation history of Europe based on pollen percentages. However, the degree of anthropogenic deforestation (i.e. cover of cultivated and grazing land) at 3k, 0.5k, and 0.2k bp is significantly higher than deduced from pollen percentages. This is also the case at 6k in some parts of Europe, in particular Britain and Ireland. Furthermore, the relationship between summer-green and evergreen trees, and between individual tree taxa, differs significantly when expressed as pollen percentages or as REVEALS estimates of tree cover. For instance, when Pinus is dominant over Picea as pollen percentages, Picea is dominant over Pinus as REVEALS estimates. These differences play a major role in the reconstruction of European landscapes and for the study of land cover-climate interactions, biodiversity and human resources.Peer reviewe