Analyse des systèmes agroforestiers du territoire de Vavatenina à Madagascar : stratégies de mise en valeur, perceptions paysannes et résilience

A Vavatenina (Madagascar), la comparaison de la situation entre 1966 et 2016 a montré une forte évolution (0 à 20 % du territoire) des systèmes agroforestiers complexes. Issus de cultures pérennes en monoculture (café), la tendance est à la diversification (giroflier, litchi, vanille, autres fruitiers et arbres à bois de chauffe ou d'oeuvre, plantes médicinales). Le contexte agro-écologique et économique (accès aux marchés) et social influent fortement sur la structure des SAF et sur les stratégies paysannes. Ces SAF jouent un rôle croissant en termes de résilience des systèmes productifs face à des risques économiques croissants (volatilité des prix). On est globalement passé d'une résilience "apparente" directe (autoconsommation du riz produit) à une résilience "économique" indirecte basée sur plusieurs cultures de rente avec une profitabilité largement supérieure ce qui constitue une stratégie originale dans le contexte malgache d'incertitudes multiples

The Use of the Operand-Recognition Paradigm for the Study of Mental Addition in Older Adults

Objectives. Determining how individuals solve arithmetic problems is crucial for our understanding of human cognitive architecture. Elderly adults are supposed to use memory retrieval more often than younger ones. However, they might backup their retrieval by reconstructive strategies. In order to investigate this issue, we used the operand-recognition paradigm, which capitalizes on the fact that algorithmic procedures degrade the memory traces of the operands. Method. Twenty-three older adults (M = 70.4) and 23 younger adults (M = 20.0) solved easy, difficult, and medium-difficulty addition and comparison problems and were then presented with a recognition task of the operands. Results. When one-digit numbers with sums larger than 10 were involved (medium-difficulty problem), it was more difficult for younger adults to recognize the operands after addition than comparison. In contrast, in older adults, recognition times of the operands were the same after addition and comparison. Discussion. Older adults, in contrast with younger adults, are able to retrieve the results of addition problems of medium difficulty. Contrary to what was suggested, older participants do not seem to resort to backup strategies for such problems. Finally, older adults' reliance on the more efficient retrieval strategy allowed them to catch up to younger adults in terms of solution time

De la vitupération. Le pamphlet et les régimes du « dire vrai » en politique

Cet article s’efforce de présenter une généalogie du pamphlet en l’inscrivant dans une filiation à la fois philosophique et discursive de la prise de parole risquée. En sollicitant plus particulièrement la notion de parrêsia travaillée par Michel Foucault, on peut analyser le pamphlet comme l’avatar historique, et quelque peu dévoyé, d’un exercice de franc-parler porté par une figure solitaire et missionnaire. Dès lors, la question se pose des évolutions du genre pamphlétaire au prisme des mutations sociologiques des sociétés démocratiques contemporaines.This article seeks to draw up a genealogy for the pamphlet by means of fitting the latter within both a philosophical and discursive lineage of the risky speech. Relying widely on Michel Foucault’s notion of parrêsia, the article defines the pamphlet as a slightly depraved historical manifestation of an act of outspokenness performed by a solitary missionary figure. Hence the genre is unlikely to evolve without being affected by the changing sociological trends in contemporary democratic societies.Este artículo se esfuerza de presentar una genealogía del panfleto inscribiéndolo en una trayectoria a la vez filosófica y discursiva de la toma de la palabra arriesgada. Tomando en cuenta más particularmente la noción de parrêsia elaborada por Michel Foucault, se puede analizar el panfleto como el avatar histórico, ya un poco degenerado, de un ejercicio de la franqueza elaborado por una figura solitaria y misionaria. Se plantea pués la temática de las evoluciones del género panfletario a través de las mutaciones sociológicas de las sociedades democráticas contemporaneas

M³: a multiphase, multiconstituant and multiprocess code to model contaminated

70% of the contaminated sites in France are with organic compounds (hydrocarbons, chlorinated solvents,…). Modeling such contamination can be difficult as it is governed by numerous and highly coupled mechanisms (multiphase flow, dissolution and volatilization of Non Aqueous Phase Liquids(NAPL), sorption and biodegradation). Whereas many numerical codes include some of these mechanisms, none of them, to our knowledge, allows the modeling of the full set of mechanisms. A new code, called M3 for Multiphase, Multicomponent, Multiprocess, is then being developed to address this kind of modeling. The originality of the code stands both in the diversity of the mechanisms and in original formalisms such as non-local equilibrium dissolution of NAPL or biodegradation formalism dedicated to chlorinated solvents. After a short description of the numerical code, test cases will be presented to highlight the capacity of the code to model many situations that might be accoutered when dealing with contaminated sites (prediction of an accidental spill, temporal evolution of a source zone and its impact on aquifers, assessment of biodegradation…)

Les mutations du pamphlet dans la France contemporaine

Texte violent, et généralement court, attaquant les institutions ou un personnage connu, le pamphlet se présente comme une modalité particulière de littérarisation du politique et de politisation de la littérature, dont les formes et les supports sont apparus très variables au cours de l’histoire. Contre les usages relâchés du terme, Marc Angenot avait entrepris, dans un travail pionnier, de réserver le qualificatif de pamphlet à une configuration discursive spécifique, porteuse de symptômes idéologiques, qui aurait connu son âge d’or en France sous la Troisième République. Cet article, qui constitue une introduction générale au dossier « Que devient le pamphlet ? », s’inspire de cette étude pour analyser les recompositions contemporaines de la parole pamphlétaire. De fait, si notre époque ne méconnaît pas le pamphlet, ce dernier ne dessine plus nettement les frontières d’un espace critique autonome, bien identifiable par ses acteurs, ses lieux et ses interactions.A rather short, vehement text targeting either institutions or a public personality, the pamphlet can be defined as a peculiar modality of a literary-minded political writing as well as some kind of politicization of literature, whose forms and conventions have appeared in various ways throughout history. In a pioneer work intended to thwart the loose common uses of the word, Marc Angenot has established the term pamphlet exclusively as a specific discursive configuration thoroughly invested in the realm of ideology. He has located its rise to prominence in France in the Third Republic era. This article, which constitutes a general introduction to our issue « Whatever became of the pamphlet ? », draws its inspiration from Angenot’s study so as to analyse contemporary changes in pamphleteering. Actually, the reason why the pamphlet nowadays is not acknowledged as a proper genre is obviously linked to the fact that it no longer possesses a clear-cut framework for a self-contained critical space one can easily identify thanks to its own players, premises and interactions.Texto violento, y generalmente corto, que ataca las instituciones o un personaje conocido, el panfleto se presenta como una modalidad particular de literaturización de lo político y de politización de la literatura cuyas formas y soportes materiales se presentaron de diversas maneras en la historia. Contra los usos triviales de la expresión, Marc Angenot reservó en su obra pionera el calificativo de panfleto a una configuración discursiva específica, cargada de síntomas ideológicos que conoció su edead de oro en Francia bajo la Tercera República. Este artículo constituye una introducción general a la problemática « ¿ Qué se hizo del panfleto ? » inspirándose de este estudio para analizar las recomposiciónes contemporaneas de la palabra panfletaria. De facto, si nuestra época no desconoce el panfleto, este no desdibuja más de manera tan nítida, las fronteras de un espacio crítico autónomo, claramente identificable por sus actores, sus lugares e interacciones

Analysis of complex trophic networks reveals the signature of land-use intensification on soil communities in agroecosystems

Increasing evidence suggests that agricultural intensification is a threat to many groups of soil biota, but how the impacts of land-use intensity on soil organisms translate into changes in comprehensive soil interaction networks remains unclear. Here for the first time, we use environmental DNA to examine total soil multi-trophic diversity and food web structure for temperate agroecosystems along a gradient of land-use intensity. We tested for response patterns in key properties of the soil food webs in sixteen fields ranging from arable crops to grazed permanent grasslands as part of a long-term management experiment. We found that agricultural intensification drives reductions in trophic group diversity, although taxa richness remained unchanged. Intensification generally reduced the complexity and connectance of soil interaction networks and induced consistent changes in energy pathways, but the magnitude of management-induced changes depended on the variable considered. Average path length (an indicator of food web redundancy and resilience) did not respond to our management intensity gradient. Moreover, turnover of network structure showed little response to increasing management intensity. Our data demonstrates the importance of considering different facets of trophic networks for a clearer understanding of agriculture-biodiversity relationships, with implications for nature-based solutions and sustainable agriculture

Within-host dynamics of the emergence of tomato yellow leaf curl virus recombinants

Tomato yellow leaf curl virus (TYLCV) is a highly damaging begomovirus native to the Middle East. TYLCV has recently spread worldwide, recombining with other begomoviruses. Recent analysis of mixed infections between TYLCV and Tomato leaf curl Comoros begomovirus (ToLCKMV) has shown that, although natural selection preserves certain co-evolved intra-genomic interactions, numerous and diverse recombinants are produced at 120 days post-inoculation (dpi), and recombinant populations from different tomato plants are very divergent. Here, we investigate the population dynamics that lead to such patterns in tomato plants co-infected with TYLCV and ToLCKMV either by agro-inoculation or using the natural whitefly vector Bemisia tabaci . We monitored the frequency of parental and recombinant genotypes independently in 35 plants between 18 and 330 dpi and identified 177 recombinants isolated at different times. Recombinants were detected from 18 dpi and their frequency increased over time to reach about 50% at 150 dpi regardless of the inoculation method. The distribution of breakpoints detected on 96 fully sequenced recombinants was consistent with a continuous generation of new recombinants as well as random and deterministic effects in their maintenance. A severe population bottleneck of around 10 genomes was estimated during early systemic infection-a phenomenon that could account partially for the heterogeneity in recombinant patterns observed among plants. The detection of the same recombinant genome in six of the thirteen plants analysed beyond 30 dpi supported the influence of selection on observed recombination patterns. Moreover, a highly virulent recombinant genotype dominating virus populations within one plant has, apparently, the potential to be maintained in the natural population according to its infectivity, within-host accumulation, and transmission efficiency - all of which were similar or intermediate to those of the parent genotypes. Our results anticipate the outcomes of natural encounters between TYLCV and ToLCKMV

Essais de fluage confinés et thermorégulés sur enrobés bitumineux : expérimentation et modélisation

Pour étudier les déformations permanentes des enrobés bitumineux, un essai triaxial thermorégulé à pression de confinement constante a été developpé. Des essais de fluage à contrainte imposée ont permis d'étudier l'influence des paramètres pression de confinement, déviateur de contraintes et température sur le comportement des enrobés. Ils ont aussi permis de valider le principe d'équivalence temps température en grandes déformations. Un modèle élasto-visco-plastique pouvant être intégré dans un calcul structurel, a été développé pour simuler les essais de fluage

Review of the current status of RAS mutation testing in patients with metastatic colorectal cancer (mCRC): Flash-RAS study

Présentation PosterInternational audienceOBJECTIVES: In 2013, it was shown that mutations in KRAS exons 3 and 4, or NRAS exons 2 to 4 had a similar effect. The primary objective was to assess the practices in conducting RAS testing in 2014. The secondary objectives were to describe the evolution of the RAS testing prescription rates from 2011, the process and time required to obtain the results, and to analyze their impact on the therapeutic strategy. METHODS: FLASH-RAS is an observational retrospective French multicenter study. RESULTS: 375 mCRC patients diagnosed and initiating a 1st line treatment (L1) between March and June 2014 were analyzed. For 90.1% of the patients (IC95%= [87.1%; 93.2%]), a genotyping request for RAS biomarkers was made in L1, i.e. a significantly increased rate compared to 2011 (81.1% in 2011, p<0.001). For 75% of the patients, the request was made before or at least one month after the diagnosis of the first metastases (1st M). No increase was observed in the median and mean times to obtain the test results between 2011 and 2014 despite the increased number of exons tested. CONCLUSIONS: In 2014, the rate of RAS genotyping requests has been increasing since 2011. For a majority of patients, the request is made before or at the latest one month after 1st M diagnosis. Nevertheless, for 24.5% of the patients, the request is made more than one month after 1st M diagnosis, which is not compatible with an informed treatment decision in L1