81 research outputs found

    Analyse du cycle de vie d'un système bioélectrochimique en tant que plate-forme technologique innovante pour la production d'acide succinique à partir de déchets

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    International audienceWaste management is a key environmental and socio-economic issue. Environmental concerns are encouraging the use of alternative resources and lower emissions to air, water and soil. Innovative technologies to deal with waste recovery that produce marketable bioproducts are emerging. Bioelectrochemical synthesis systems (BESs) are based on the primary principle of transforming organic waste into added-value products using microorganisms to catalyse chemical reactions. This technology is at the core of a research project called BIORARE (BIoelectrosynthesis for ORganic wAste bioREfinery), an interdisciplinary project that aims to use anaerobic digestion as a supply chain to feed a BES and produce target biomolecules. This technology needs to be driven by environmental strategies. Life Cycle Assessment (LCA) was used to evaluate the BIORARE concept based on expert opinion and prior experiments for the production of biosuccinic acid and waste management. A multidisciplinary approach based on biochemistry and process engineering expertise was used to collect the inventory data. The BES design and the two-step anaerobic digestion process have many potential impacts on air pollution or ecotoxicity-related categories. The comparison of the BIORARE concept with conventional fermentation processes and a water-fed BES technology demonstrated the environmental benefit resulting from the use of both the BES technology and a waste-based substrate as input thus supporting the BIORARE concept. Some trade-offs among the impact categories were identified but led to options to improve the concept. BES design and synergy management may improve the environmental performance of the BIORARE concep

    Morphometrics as an Insight Into Processes Beyond Tooth Shape Variation in a Bank Vole Population

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    Phenotype variation is a key feature in evolution, being produced by development and the target of the screening by selection. We focus here on a variable morphological feature: the third upper molar (UM3) of the bank vole, aiming at identifying the sources of this variation. Size and shape of the UM3 occlusal surface was quantified in successive samples of a bank vole population. The first source of variation was the season of trapping, due to differences in the age structure of the population in turn affecting the wear of the teeth. The second direction of variation corresponded to the occurrence, or not, of an additional triangle on the tooth. This intra-specific variation was attributed to the space available at the posterior end of the UM3, allowing or not the addition of a further triangle.This size variation triggering the shape polymorphism is not controlled by the developmental cascade along the molar row. This suggests that other sources of size variation, possibly epigenetic, might be involved. They would trigger an important shape variation as side-effect by affecting the termination of the sequential addition of triangles on the tooth

    Factors associated with diversity, quantity and zoonotic potential of ectoparasites on urban mice and voles

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    Wild rodents are important hosts for tick larvae but co-infestations with other mites and insects are largely neglected. Small rodents were trapped at four study sites in Berlin, Germany, to quantify their ectoparasite diversity. Host-specific, spatial and temporal occurrence of ectoparasites was determined to assess their influence on direct and indirect zoonotic risk due to mice and voles in an urban agglomeration. Rodent-associated arthropods were diverse, including 63 species observed on six host species with an overall prevalence of 99%. The tick Ixodes ricinus was the most prevalent species, found on 56% of the rodents. The trapping location clearly affected the presence of different rodent species and, therefore, the occurrence of particular host-specific parasites. In Berlin, fewer temporary and periodic parasite species as well as non-parasitic species (fleas, chiggers and nidicolous Gamasina) were detected than reported from rural areas. In addition, abundance of parasites with low host-specificity (ticks, fleas and chiggers) apparently decreased with increasing landscape fragmentation associated with a gradient of urbanisation. In contrast, stationary ectoparasites, closely adapted to the rodent host, such as the fur mites Myobiidae and Listrophoridae, were most abundant at the two urban sites. A direct zoonotic risk of infection for people may only be posed by Nosopsyllus fasciatus fleas, which were prevalent even in the city centre. More importantly, peridomestic rodents clearly supported the life cycle of ticks in the city as hosts for their subadult stages. In addition to trapping location, season, host species, body condition and host sex, infestation with fleas, gamasid Laelapidae mites and prostigmatic Myobiidae mites were associated with significantly altered abundance of I. ricinus larvae on mice and voles. Whether this is caused by predation, grooming behaviour or interaction with the host immune system is unclear. The present study constitutes a basis to identify interactions and vector function of rodent-associated arthropods and their potential impact on zoonotic diseases

    What did we achieve with VALITEST an EU project on validation in plant pest diagnostics?

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    peer reviewedEnsuring the reliability of diagnostic activities is an essential cornerstone of Plant Health strategies to reduce the risk of entry and spread of plant pests in a region and ultimately their impacts. Diagnostic tests should be validated to ensure that they are fit for purpose. Validation is usually done by diagnostic laboratories although companies commercializing diagnostic kits also produce validation data for their products. Due to the high number of pest , matrix and method combinations and given the significant resources required to validate tests, it is essential that validation data are shared with the entire diagnostic community and produced in a harmonized way to facilitate their use by different stakeholders. Indeed, the selection of tests to be used in specific contexts is not the sole responsibility of diagnostic laboratories and also involve National Plant Protection Organizations. The VALITEST EU project (2018-2021) was established to tackle all these issues. New validation data for tests targeting important pests for the EPPO region were produced. Guidelines to improve and harmonize the validation framework were developed. Sharing of validation data and experience was ensured through the development of new or existing databases, the organization of training courses and the dissemination of the project outputs in scientific publications and Standards. Finally, the involvement of researchers, diagnosticians, policy makers, inspectors, industries etc. and the establishment of the European Plant Diagnostic Industry Association were important actions to strengthen the interactions between Plant Health stakeholders

    Evaluation of βLACTA™ test, a rapid test detecting resistance to third-generation cephalosporins in clinical strains of Enterobacteriaceae.

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    Since decades, third-generation cephalosporins (3GC) are major drugs to treat infections due to Enterobacteriaceae; growing resistance to these antibiotics makes important to rapidly detect such resistance. βLACTA™ test is a chromogenic test developed for detecting within 15 minutes 3GC-resistant isolates from cultures on solid media. A multi-center prospective study conducted in 5 French and Belgian hospitals evaluated the performances of this test on clinical isolates. Based on antibiotic susceptibility testing, strains resistant or intermediate to cefotaxime or ceftazidime were classified as 3GC-resistant and molecular characterization of this resistance was performed. The rate of 3GC-resistance was globally 13.9% (332/2387), 9.4% in Escherichia coli (132/1403), 25.6% in Klebsiella pneumoniae (84/328), 30.3% in species naturally producing inducible AmpC beta-lactamases (109/360), and 5.6% in Klebsiella oxytoca and Citrobacter koseri (7/124). The overall sensitivity and specificity of βLACTA™ test were 87.7% and 99.6% respectively, were 96 and 100% for E. coli and K. pneumoniae and were 67.4% and 99.6% for species naturally producing inducible AmpC beta-lactamase. False negative results were mainly related to 3GC-resistant strains producing AmpC beta-lactamase. Interestingly, the test was positive for all 3GC-resistant extended-spectrum beta-lactamase producing isolates (n=241). Positive predictive value was 97% and would remain ≥ 96% for prevalence of 3GC-resistance ranging between 10 and 30%. Negative predictive value was 99% for E. coli and K. pneumoniae and 89% for the species producing inducible AmpC beta-lactamase.In conclusion βLACTA™ test was found to be easy to use and efficient to predict resistance to third-generation cephalosporins, particularly in extended-spectrum beta-lactamase producing strains

    Q fever and Mediterranean spotted fever associated with hemophagocytic syndrome: case study and literature review

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    Hemophagocytosis during Q fever (QF) and Mediterranean spotted fever (MSF) is rare and only a few cases have been reported. We aimed to investigate the characteristics, outcome, and treatment of QF/MSF-associated hemophagocytosis

    Drop propulsion in tapered tubes

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    An Erratum for this article has been published in 2009 EPL 87 39901We present the results of a combined experimental and theoretical investigation of the motion of wetting droplets in tapered capillary tubes. We demonstrate that drops may move spontaneously towards the tapered end owing to the Laplace pressure gradient established along their length. The influence of gravity on this spontaneous motion is examined by studying drop motion along a tilted tube with its tapered end pointing upwards. Provided the tube taper varies, an equilibrium height may be achieved in which the capillary force is balanced by the drop's weight. We deduce the family of tube shapes that support a stable equilibrium
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