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International audience; Alien species can be a major threat to ecological communities, but we do not know why some community types allow the entry of many more alien species than do others. Here, for the first time, we suggest that evolutionary diversity inherent to the constituent species of a community may determine its present receptiveness to alien species. Using recent large databases from observational studies, we find robust evidence that assemblage of plant community types from few phylogenetic lineages (in plots without aliens) corresponds to higher receptiveness to aliens. Establishment of aliens in phylogenetically poor communities corresponds to increased phylogenetic dispersion of recipient communities and to coexistence with rather than replacement of natives. This coexistence between natives and distantly related aliens in recipient communities of low phylogenetic dispersion may reflect patterns of trait assembly. In communities without aliens, low phylogenetic dispersion corresponds to increased dispersion of most traits, and establishment of aliens corresponds to increased trait concentration.We conclude that if quantified across the tree of life, high biodiversity correlates with decreasing receptiveness to aliens. Low phylogenetic biodiversity, in contrast, facilitates coexistence between natives and aliens even if they share similar trait states.

International audience; In literature about missionary activities in western Siberia in the 19th – early 20th century, the natives are seen as passive recipients of the missionaries’ initiative, as victims of their endeavours. This article intends to present another view of the encounter, showing firstly why this erroneous vision developed and secondly how the Khanty and the Nenets are actually active in the interaction. It shows how in both cases, either by accepting or by refusing, the natives follow their own interests and their own decisions without submitting to stronger constraint against their will. While those who refused to accept the missionaries’ endeavours clearly expressed their independence, those who chose to convert did it sincerely, although their understanding of Christianity did not match the missionaries’ expectations. They did it for conscious reasons, not just yielding to the missionaries’ wishes but often being themselves the initiators. For them, Christianity is integrated in a worldview that is not based on dual oppositions. Therefore, while representatives of official Christianity do not see these natives as real Christians, they consider themselves to be so.; Dans la littérature sur les activités missionnaires en Sibérie Occidentale au tournant des XIXe et XXe siècles, les autochtones sont vus en général comme les destinataires de l'initiative des missionnaires et comme des victimes de ceux-ci. Cet article entend présenter une autre vision de la rencontre: il montre d'abord pourquoi cette vision erronée a été développée et deuxièmement que les Khantys et les Nénetses sont en fait actifs dans cette interaction. Il montre que quelle que soit l'issue de la rencontre, qu'ils acceptent ou qu'ils refusent, les autochtones suivent leurs propres intérêts et leurs décisions à eux et ne se soumettent pas à une volonté qui serait plus forte que la leur. Alors que ceux qui refusent les propositions des missionnaires expriment clairement leur indépendance, ceux qui se convertissent le font sincèrement, même si leur compréhension du christianisme ne correspond pas aux attentes des missionnaires. Ils le font pour des raisons conscientes et ne se limitent pas à accepter des offres. Souvent, ils sont eux-mêmes initiateurs. Pour eux, le christianisme est intégré dans une vision du monde qui ne repose pas sur des oppositions binaires. C'est pourquoi les représentants du christianisme official ne les reconnaissent pas comme de vrais chrétiens, alors qu'eux se voient comme tels.

International audience; Bolbozoid and cypridinid myodocope ostracods from France, the Czech Republic and Sardinia consist of four genera (one new: Silurocypridina) and at least ten species (eight new: Bolbozoe acuta, B. rugosa, B. parvafraga, Para-bolbozoe armoricana, Silurocypridina retroreticulata, S. vario-striata, S. calva and Calocaria robusta). They have a functional design, palaeogeographical distribution, depositional setting and faunal associates that suggest that they were swimmers in the water column, living in dim light, relatively deep environments, above near bottom dysoxic/anoxic conditions. These myodocope faunas include some possible pelagic species sensu stricto, with widespread palaeogeographical (transoceanic) distribution, and some species that occupied hyperbenthic niches and were capable of making short incursions to the sediment to scavenge on carrion. These data support the model that Silurian myodocopes were pioneer pelagic ostracods.

International audience; Cell penetrating peptides constitute a potent approach to overcome the limitations of in vivo siRNA delivery. We recently proposed a peptide-based nanoparticle system, CADY, for efficient delivery of siRNA into numerous cell lines. CADY is a secondary amphipathic peptide that forms stable complexes with siRNA thereby improving both their cellular uptake and biological response. With the aim of understanding the cellular uptake mechanism of CADY:siRNA complexes, we have combined biochemical, confocal and electron microscopy approaches. In the present work, we provide evidence that the major route for CADY:siRNA cellular uptake involves direct translocation through the membrane but not the endosomal pathway. We have demonstrated that CADY:siRNA complexes do not colocalize with most endosomal markers and remain fully active in the presence of inhibitors of the endosomal pathway. Moreover, neither electrostatic interactions with cell surface heparan sulphates nor membrane potential are essential for CADY:siRNA cell entry. In contrast, we have shown that CADY:siRNA complexes clearly induce a transient cell membrane permeabilization, which is rapidly restored by cell membrane fluidity. Therefore, we propose that direct translocation is the major gate for cell entry of CADY:siRNA complexes. Membrane perturbation and uptake are driven mainly by the ability of CADY to interact with phospholipids within the cell membrane, followed by rapid localization of the complex in the cytoplasm, without affecting cell integrity or viability.

International audience; ABSTRACT: BACKGROUND: Late onset neonatal sepsis (LOS) with the mortality of 17 to 27% is still a serious disease. Meropenem is an antibiotic with wide antibacterial coverage. The advantage of it over standard of care could be its wider antibacterial coverage and thus the use of mono- instead of combination therapy. METHODS: NeoMero1, an open label, randomised, comparator controlled, superiority trial aims to compare the efficacy of meropenem with a predefined standard of care (ampicillin plus gentamicin or cefotaxime plus gentamicin) in the treatment of LOS in neonates and infants aged less than 90 days admitted to a neonatal intensive care unit. A total of 550 subjects will be recruited following a 1:1 randomisation scheme. The trial includes patients with culture confirmed (at least one positive culture from normally sterile site except coagulase negative staphylococci in addition to one clinical or laboratory criterion) or clinical sepsis (at least two laboratory and two clinical criteria suggestive of LOS in subjects with postmenstrual age less than 44 weeks or fulfilment of criteria established by the International Pediatric Sepsis Consensus Conference in subjects with postmenstrual age [greater than or equal to] 44 weeks). Meropenem will be given at a dose of 20 mg/kg q12h or q8h depending on the gestational- and postnatal age. Comparator agents are administered as indicated in British National Formulary for Children. The primary endpoint measured at the test of cure visit (2 days after end of study therapy) and is graded to success (all baseline symptoms and laboratory parameters are resolved or improved with no need to continue antibiotics and the baseline microorganisms are eradicated and no new microorganisms are identified and the patient has received allocated treatment for 11 plus/minus 3 days with no modification) or a failure (all remaining cases). Secondary outcome measures include comparison of survival, relapse rates or new infections by Day 28, clinical response at Day 3 and end of therapy, duration of hospitalisation, population pharmacokinetic analysis of meropenem and effect of antibiotics on mucosal colonisation and development of antibacterial resistance. The study will start recruitment in September 2011; the total duration is of 24 months. Trial registration: EudraCT 2011-001515-31.

Wikipedia has been hailed as one of the most prominent peer projects that led to the rise of the concept of peer governance. However, criticism has been levelled against Wikipedia's mode of governance. This paper, using the Wikipedia case as a point of departure and building upon the conflict between inclusionists and deletionists, tries to identify and draw some conclusions on the problematic issue of peer governance.

International audience; The mechanisms of regulation of respiration and energy fluxes in the cells are analyzed based on the concepts of systems biology, non-equilibrium steady state kinetics and applications of Wiener's cybernetic principles of feedback regulation. Under physiological conditions cardiac function is governed by the Frank-Starling law and the main metabolic characteristic of cardiac muscle cells is metabolic homeostasis, when both workload and respiration rate can be changed manifold at constant intracellular level of phosphocreatine and ATP in the cells. This is not observed in skeletal muscles. Controversies in theoretical explanations of these observations are analyzed. Experimental studies of permeabilized fibers from human skeletal muscle vastus lateralis and adult rat cardiomyocytes showed that the respiration rate is always an apparent hyperbolic but not a sigmoid function of ADP concentration. It is our conclusion that realistic explanations of regulation of energy fluxes in muscle cells require systemic approaches including application of the feedback theory of Wiener's cybernetics in combination with detailed experimental research. Such an analysis reveals the importance of limited permeability of mitochondrial outer membrane for ADP due to interactions of mitochondria with cytoskeleton resulting in quasi-linear dependence of respiration rate on amplitude of cyclic changes in cytoplasmic ADP concentrations. The system of compartmentalized creatine kinase (CK) isoenzymes functionally coupled to ANT and ATPases, and mitochondrial-cytoskeletal interactions separate energy fluxes (mass and energy transfer) from signalling (information transfer) within dissipative metabolic structures - intracellular energetic units (ICEU). Due to the non-equilibrium state of CK reactions, intracellular ATP utilization and mitochondrial ATP regeneration are interconnected by the PCr flux from mitochondria. The feedback regulation of respiration occurring via cyclic fluctuations of cytosolic ADP, Pi and Cr/PCr ensures metabolic stability necessary for normal function of cardiac cells.

International audience; In mammals, plasma amino acid concentrations are markedly affected by dietary or pathological conditions. It has been well established that amino acids are involved in the control of gene expression. Up to now, all the information concerning the molecular mechanisms involved in the regulation of gene transcription by amino acid availability has been obtained in cultured cell lines. The present study aims to investigate the mechanisms involved in transcriptional activation of the TRB3 gene following amino acid limitation in mice liver. The results show that TRB3 is up-regulated in the liver of mice fed a leucine-deficient diet and that this induction is quickly reversible. Using transient transfection and chromatin immunoprecipitation approaches in hepatoma cells, we report the characterization of a functional Amino Acid Response Element (AARE) in the TRB3 promoter and the binding of ATF4, ATF2 and C/EBP beta to this AARE sequence. We also provide evidence that only the binding of ATF4 to the AARE plays a crucial role in the amino acid-regulated transcription of TRB3. In mouse liver, we demonstrate that the GCN2/eIF2 alpha/ATF4 pathway is essential for the induction of the TRB3 gene transcription in response to a leucine-deficient diet. Therefore, this work establishes for the first time that the molecular mechanisms involved in the regulation of gene transcription by amino acid availability are functional in mouse liver.

International audience; This article analyses the films made by the Estonian National Museum in the 1970s and the 1980s both from the point of view of the filming activity and of the content of these films. Although the Museum's director, Aleksei Peterson, who developed this activity, was mainly interested in strictly ethnographic film, the legacy from this period consists mainly, but not only, of film monographs made both in Estonia and in the Finno-Ugric regions. These films encompass the ethnographers' knowledge of the reconstructed period, the beginning of the 20th century. Nonetheless, the films made in Udmurtia contain several shots that reflect skills and practices still active at the end of that century. Other films are totally shot spontaneously, and there is also an example of comparative material. These forgotten films deserve to be remembered.; Cet article analyse les films réalisés par le Musée national estonien dans les années 1970 et 1980 aussi bien du point de vue de l'activité filmique que du contenu des films. Bien que le directeur du musée de l'époque, Aleksei Peterson, qui développa cette activité, ne fût intéressé qu'à produire des films strictement ethnographiques, l'héritage de cette période rient surtout à des monographies filmiques tournées en Estonie et dans les régions finno-ougriennes. Ces films couvrent la connaissance des ethnographes sur une période reconstruite, celle du début du XXe siècle. Pourtant, les films réalisés en Oudmourtie contiennent bien des cadres qui reflètent des pratiques et des savoir-faire encore actifs à la fin du siècle. D'autres films ont été tournés spontanément, et il y a même un exemple de matériau comparatifs. Ces films méritent d'être sortis de l'oubli.

International audience; Problems of quantitative investigation of intracellular diffusion and compartmentation of metabolites are analyzed. Principal controversies in recently published analyses of these problems for the living cells are discussed. It is shown that the formal theoretical analysis of diffusion of metabolites based on Fick's equation and using fixed diffusion coefficients for diluted homogenous aqueous solutions, but applied for biological systems in vivo without any comparison with experimental results, may lead to misleading conclusions, which are contradictory to most biological observations. However, if the same theoretical methods are used for analysis of actual experimental data, the apparent diffusion constants obtained are orders of magnitude lower than those in diluted aqueous solutions. Thus, it can be concluded that local restrictions of diffusion of metabolites in a cell are a system-level properties caused by complex structural organization of the cells, macromolecular crowding, cytoskeletal networks and organization of metabolic pathways into multienzyme complexes and metabolons. This results in microcompartmentation of metabolites, their channeling between enzymes and in modular organization of cellular metabolic networks. The perspectives of further studies of these complex intracellular interactions in the framework of Systems Biology are discussed.

Aim of study: The present study evaluates a set of competition indices including spatially explicit indices combined with different competitor selection approaches and non-spatially explicit competition indices. The aim was to quantify and describe the neighbouring effects on the tree diameter growth of silver birch trees.Area of study: Region throughout Estonia. Material and methods: Data from the Estonian Network of Forest Research Plots was used. After quantifying the selected indices, the best non-spatial indices and spatial indices (combined with neighbour selection methods) were separately devised into a growth model as a predictor variable to assess the ability of the diameter growth model before and after adding competition measures. To test the species-specific effect on the competition level, the superior indices were recalculated using Ellenberg’s light indicators and incorporated into the diameter growth model. Main results: Statistical analyses showed that the diameter growth is a function of neighbourhood interactions and spatial indices were better growth predictors than non-spatial indices. In addition, the best selections of competitive neighbours were acquired based on the influence zone and the competition elimination angle concepts, and using Ellenberg’s light values had no significant improvement in quantifying the competition effects. Research highlights: Although the best ranking spatial competition measures were superior to the best non-spatial indices, the differences were negligible.Keywords: Competition indices; zone of influence; stem diameter increment; Betula pendula Roth.

Summary • The relationships between foliar photosynthetic variables and monoterpene emission rates (E) are reported here for two sclerophylls, Quercus coccifera L. and Q. ilex L., which lack specialized foliar monoterpene-storage structures. • Photosynthesis rates and E were measured within a forest canopy, and in leaves of different exposure in a garrigue ecosystem. Leaf dry mass per unit area (LMA) was used as a proxy of long-term leaf light availability. • Maximum photosynthetic electron transport rate (Jmax), Rubisco carboxylase activity (Vcmax) and light-saturated E (Emax) per unit area increased strongly with increasing LMA. The positive effect of LMA on area-based Emax resulted from an accumulation of enzymes responsible for monoterpenoid synthesis per unit area. Positive relationships were observed between both area- and mass-based Emax and Jmax, but not with photosynthesis rates, suggesting a possible control of terpene synthesis by foliar electron transport rates. Results suggested that monoterpene volatility limitations at low temperatures might also constrain E. Nonspecific storage may explain bursts of monoterpene emission on warm days following cold days, and monoterpene emission in low quantities during night. • Although the correlations between Emax and Jmax do not necessarily give mechanistic insight into the physiology of monoterpene emission, they provide a basis for scaling up leaf emissions to a canopy level. However, both the leaf-to-leaf differences in monoterpene synthase activities, and monoterpene storage may perplex the relations between the electron transport rates and E.