26 research outputs found

    A Tale of Four Stories: Soil Ecology, Theory, Evolution and the Publication System

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    International audienceBACKGROUND: Soil ecology has produced a huge corpus of results on relations between soil organisms, ecosystem processes controlled by these organisms and links between belowground and aboveground processes. However, some soil scientists think that soil ecology is short of modelling and evolutionary approaches and has developed too independently from general ecology. We have tested quantitatively these hypotheses through a bibliographic study (about 23000 articles) comparing soil ecology journals, generalist ecology journals, evolutionary ecology journals and theoretical ecology journals. FINDINGS: We have shown that soil ecology is not well represented in generalist ecology journals and that soil ecologists poorly use modelling and evolutionary approaches. Moreover, the articles published by a typical soil ecology journal (Soil Biology and Biochemistry) are cited by and cite low percentages of articles published in generalist ecology journals, evolutionary ecology journals and theoretical ecology journals. CONCLUSION: This confirms our hypotheses and suggests that soil ecology would benefit from an effort towards modelling and evolutionary approaches. This effort should promote the building of a general conceptual framework for soil ecology and bridges between soil ecology and general ecology. We give some historical reasons for the parsimonious use of modelling and evolutionary approaches by soil ecologists. We finally suggest that a publication system that classifies journals according to their Impact Factors and their level of generality is probably inadequate to integrate "particularity" (empirical observations) and "generality" (general theories), which is the goal of all natural sciences. Such a system might also be particularly detrimental to the development of a science such as ecology that is intrinsically multidisciplinary

    Global Analysis of Proline-Rich Tandem Repeat Proteins Reveals Broad Phylogenetic Diversity in Plant Secretomes

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    Cell walls, constructed by precisely choreographed changes in the plant secretome, play critical roles in plant cell physiology and development. Along with structural polysaccharides, secreted proline-rich Tandem Repeat Proteins (TRPs) are important for cell wall function, yet the evolutionary diversity of these structural TRPs remains virtually unexplored. Using a systems-level computational approach to analyze taxonomically diverse plant sequence data, we identified 31 distinct Pro-rich TRP classes targeted for secretion. This analysis expands upon the known phylogenetic diversity of extensins, the most widely studied class of wall structural proteins, and demonstrates that extensins evolved before plant vascularization. Our results also show that most Pro-rich TRP classes have unexpectedly restricted evolutionary distributions, revealing considerable differences in plant secretome signatures that define unexplored diversity

    The binding of Varp to VAMP7 traps VAMP7 in a closed, fusogenically inactive conformation.

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    SNAREs provide energy and specificity to membrane fusion events. Fusogenic trans-SNARE complexes are assembled from glutamine-contributing SNAREs (Q-SNAREs) embedded in one membrane and an arginine-contributing SNARE (R-SNARE) embedded in the other. Regulation of membrane fusion events is crucial for intracellular trafficking. We identify the endosomal protein Varp as an R-SNARE-binding regulator of SNARE complex formation. Varp colocalizes with and binds to VAMP7, an R-SNARE that is involved in both endocytic and secretory pathways. We present the structure of the second ankyrin repeat domain of mammalian Varp in complex with the cytosolic portion of VAMP7. The VAMP7-SNARE motif is trapped between Varp and the VAMP7 longin domain, and hence Varp kinetically inhibits the ability of VAMP7 to form SNARE complexes. This inhibition will be increased when Varp can also bind to other proteins present on the same membrane as VAMP7, such as Rab32-GTP

    Histoire des rapports hommes/nature et Ă©ducation

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    ÂżUn capitalismo verdoso?

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    Associations for the Preservation of Small-Scale Farming and Related Organisations

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    During the 2000s in France, the rapid development of “AMAP” (Associations for the Preservation of Paysan [Small-scale] Farming)— which are a sort of appropriation/adaptation of the North American Community Supported Agriculture (CSA) initiatives—can be seen as part of a wider trend towards consumers’ growing awareness of and reaction to the environmental and health risks linked to the drive for productivity in agriculture. This case study shows the strength but also the limits of these kinds of collective action. On the one hand, the emergence of AMAPs can be seen as an immediate and concrete response to this fundamental shared concern, and a very coherent one insofar as it can combine not only the protection of environment with that of health, but also the defence of small-scale farming with the interests of consumers, fair-trade with local production, activism with conviviality, and so on. But on the other hand, it can also provoke tensions and encounter limits, such as the definition of this action as solidarity versus charity, the relative absence of the lower classes, the lack of land and of local organic food producers, and the need to construct a supra-local movement in order to influence national or European policies
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