90 research outputs found

    Un cadre méthodologique pour évaluer l'équivalence entre pertes et gains de biodiversité induits par les projets d'aménagement et leurs mesures compensatoires

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    In France, the Mitigation hierarchy aims to achieve the "no net loss" (NNL) of biodiversity at the development projects scale. One of the key issues to achieve this goal is to demonstrate the ecological equivalence between the gains associated with offsets and the losses caused by the impacts. Despite regulatory improvements, the French law does not include a method to follow for determining equivalence, and none is unanimously recognized. This leads to heterogeneous practices and difficulty in reaching the NNL. In this context, we have developed a methodological framework for assessing equivalence adapted to the French regulatory and ecological context and combining three challenges: operationality, scientific basis and comprehensiveness. This methodological framework makes it possible 1 / to evaluate the biodiversity found on impacted and compensating sites by taking into account ordinary biodiversity and the one of interest, with a focus on functionalities; 2 / to estimate the value of the indicators after impact and MC, in the short and long term, taking into account associated uncertainties; and 3 / calculating losses and gains leading to a quantitative and transparent equivalence assessment. The use of the methodological framework favors dialogue between actors and also allows monitoring of offsets over time.En France, la séquence « Eviter Réduire Compenser » (ERC) a pour objectif d'atteindre « l'absence de perte nette (APN) » de biodiversité à l'échelle des projets d'aménagement. Un des enjeux clé pour y arriver consiste à démontrer l'équivalence écologique entre les gains associés aux mesures compensatoire (MC) et les pertes occasionnées par les impacts. Malgré les avancées règlementaires, le cadre français n'inclut pas de méthode à suivre pour déterminer l'équivalence et aucune n'est unanimement reconnue. Cela amène à des pratiques hétérogènes et une difficulté d'atteindre l'APN. Dans ce contexte, nous avons développé un cadre méthodologique d'évaluation de l'équivalence adapté au contexte règlementaire et écologique français, répondant à trois défis : opérationnalité, bases scientifiques et exhaustivité. Ce cadre méthodologique permet 1/ d'évaluer la biodiversité des sites impactés et compensatoires en tenant compte de la biodiversité ordinaire et à enjeu en insistant sur les fonctionnalités, 2/ d'estimer la valeur des indicateurs après impact et MC à court et long terme, en prenant en compte les incertitudes associées et 3/ de calculer les pertes et des gains, aboutissant ainsi à une évaluation quantitative et transparente de l'équivalence. L'utilisation du cadre méthodologique favorise la concertation entre acteurs et permet également un suivi des MC dans le temps

    Gut microbiota and its diet-related activity in children with intestinal failure receiving long-term parenteral nutrition

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    Background This study characterized gut microbiota and its diet-related activity in children with intestinal failure (IF) receiving parenteral nutrition (PN) compared with those of healthy controls (HC) and in relation to disease characteristics. Methods The fecal microbiota and short-chain fatty acids (SCFAs) were measured in 15 IF patients (n = 68) and 25 HC (n = 25). Results Patients with IF had a lower bacterial load (P = .003), diversity (P < .001), evenness (P < .001) and richness (P = 0.006) than HC. Patients with surgical IF had lower diversity (P < .039) than those with functional IF. Propionic acid and butyric acid (p < .001) were lower and d-lactate and l-lactate were higher (p < 0.001) in IF patients than in HC. The energy supplied by PN (%PN) was negatively associated with microbiota diversity and SCFA profile. IF patients had more Escherichia-Shigella (P = .006), Cronobacter (P = .001), and Staphylococcus (Operational Taxonomic Unit 14, P < .001) and less Faecalibacterium (P < 0.001) and Ruminococcus 1 and 2 (P < .001). Duration of PN (P = .005), %PN (P = .005), and fiber intake (P = .011) were predictive of microbiota structure. Higher intake of enteral nutrition was associated with microbiota structure and function closer to those of HC. Conclusions Microbiota composition and its diet-related function are altered in IF, with depletion of beneficial SCFAs and species and supraphysiological increase of potentially harmful pathobionts. The influence of this compositional and functional microbial dysbiosis on patients' outcomes and management warrants further exploration.Transplantation and immunomodulatio

    Assessing the effectiveness of the Ramsar Convention in preserving wintering waterbirds in the Mediterranean

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    lthough biological conservation is based on international agreements, its effectiveness depends on how countries implement such recommendations as effective conservation tools. The Ramsar Convention is the oldest international treaty for wetland and waterbird conservation, establishing the world's largest network of protected areas. However, since it does not constitute any binding measure, its effectiveness in protecting wintering waterbird populations at an international scale has been questioned. Here, we use long-term (1991–2012) count data to assess the effectiveness of the Ramsar Convention in the Mediterranean Basin. We compared abundance and temporal trends of 114 waterbird species between 251 Ramsar wetlands and 3486 non-Ramsar wetlands. We found that the Ramsar network is critical for wintering waterbirds, concentrating nearly half of all waterbirds counted in the Mediterranean Basin in only 7% of monitored wetlands. Waterbird trends followed a northwestsoutheast gradient, with a population decrease in the East. A significant and positive Ramsar effect on population trends was only found for the species of higher conservation concern in the Maghreb, particularly when a management plan was implemented. The Ramsar Convention was previously used on very important wetlands for waterbirds in Southern Europe, but is now an underused conservation tool. Our study suggests weaknesses in the use of Ramsar as an effective conservation tool in most of the Mediterranean Basin. However, the Ramsar Convention effectiveness to enhance waterbird populations in the Maghreb should encourage strengthening the Ramsar Convention. It should be done particularly in countries with limited environmental agreements and by systematic implementation of management plans. Conservation measures International conventions Protected areas Protection status Monitoring WetlandsacceptedVersio

    SPG20 Protein Spartin Associates with Cardiolipin via Its Plant-Related Senescence Domain and Regulates Mitochondrial Ca2+ Homeostasis

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    Hereditary spastic paraplegias (HSPs) are a group of neurological disorders characterized clinically by spasticity of lower limbs and pathologically by degeneration of the corticospinal tract. Troyer syndrome is an autosomal recessive HSP caused by a frameshift mutation in the spartin (SPG20) gene. Previously, we established that this mutation results in a lack of expression of the truncated mutant spartin protein. Spartin is involved in many cellular processes and associates with several intracellular organelles, including mitochondria. Spartin contains a conserved plant-related senescence domain at its C-terminus. However, neither the function of this domain nor the roles of spartin in mitochondrial physiology are currently known. In this study, we determined that the plant-related senescence domain of spartin interacts with cardiolipin but not with two other major mitochondrial phospholipids, phosphatidylcholine and phosphatidylethanolamine. We also found that knockdown of spartin by small interfering RNA in a human neuroblastoma cell line resulted in depolarization of the mitochondrial membrane. In addition, depletion of spartin resulted in a significant decrease in both mitochondrial calcium uptake and mitochondrial membrane potential in cells treated with thapsigargin. Our results suggest that impairment of mitochondrial calcium uptake might contribute to the neurodegeneration of long corticospinal axons and the pathophysiology of Troyer syndrome

    Mechanisms of the noxious inflammatory cycle in cystic fibrosis

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    Multiple evidences indicate that inflammation is an event occurring prior to infection in patients with cystic fibrosis. The self-perpetuating inflammatory cycle may play a pathogenic part in this disease. The role of the NF-κB pathway in enhanced production of inflammatory mediators is well documented. The pathophysiologic mechanisms through which the intrinsic inflammatory response develops remain unclear. The unfolded mutated protein cystic fibrosis transmembrane conductance regulator (CFTRΔF508), accounting for this pathology, is retained in the endoplasmic reticulum (ER), induces a stress, and modifies calcium homeostasis. Furthermore, CFTR is implicated in the transport of glutathione, the major antioxidant element in cells. CFTR mutations can alter redox homeostasis and induce an oxidative stress. The disturbance of the redox balance may evoke NF-κB activation and, in addition, promote apoptosis. In this review, we examine the hypotheses of the integrated pathogenic processes leading to the intrinsic inflammatory response in cystic fibrosis

    Buses, cars, bicycles and walkers the influence of the type of human transport on the flight responses of waterbirds

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    One way to manage disturbance to waterbirds in natural areas where humans require access is to promote the occurrence of stimuli for which birds tolerate closer approaches, and so cause fewer responses. We conducted 730 experimental approaches to 39 species of waterbird, using five stimulus types (single walker, three walkers, bicycle, car and bus) selected to mimic different human management options available for a controlled access, Ramsar-listed wetland. Across species, where differences existed (56% of 25 cases), motor vehicles always evoked shorter flight-initiation distances (FID) than humans on foot. The influence of stimulus type on FID varied across four species for which enough data were available for complete cross-stimulus analysis. All four varied FID in relation to stimuli, differing in 4 to 7 of 10 possible comparisons. Where differences occurred, the effect size was generally modest, suggesting that managing stimulus type (e.g. by requiring people to use vehicles) may have species-specific, modest benefits, at least for the waterbirds we studied. However, different stimulus types have different capacities to reduce the frequency of disturbance (i.e. by carrying more people) and vary in their capacity to travel around important habita

    Role of Interaction and Nucleoside Diphosphate Kinase B in Regulation of the Cystic Fibrosis Transmembrane Conductance Regulator Function by cAMP-Dependent Protein Kinase A

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    Cystic fibrosis results from mutations in the cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-dependent protein kinase A (PKA) and ATP-regulated chloride channel. Here, we demonstrate that nucleoside diphosphate kinase B (NDPK-B, NM23-H2) forms a functional complex with CFTR. In airway epithelia forskolin/IBMX significantly increases NDPK-B co-localisation with CFTR whereas PKA inhibitors attenuate complex formation. Furthermore, an NDPK-B derived peptide (but not its NDPK-A equivalent) disrupts the NDPK-B/CFTR complex in vitro (19-mers comprising amino acids 36-54 from NDPK-B or NDPK-A). Overlay (Far-Western) and Surface Plasmon Resonance (SPR) analysis both demonstrate that NDPK-B binds CFTR within its first nucleotide binding domain (NBD1, CFTR amino acids 351-727). Analysis of chloride currents reflective of CFTR or outwardly rectifying chloride channels (ORCC, DIDS-sensitive) showed that the 19-mer NDPK-B peptide (but not its NDPK-A equivalent) reduced both chloride conductances. Additionally, the NDPK-B (but not NDPK-A) peptide also attenuated acetylcholine-induced intestinal short circuit currents. In silico analysis of the NBD1/NDPK-B complex reveals an extended interaction surface between the two proteins. This binding zone is also target of the 19-mer NDPK-B peptide, thus confirming its capability to disrupt NDPK-B/CFTR complex. We propose that NDPK-B forms part of the complex that controls chloride currents in epithelia

    LE MARCHÉ DE LA CROISIÈRE EN EUROPE ET AU HAVRE

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    Le marché de la croisière est en plein développement ces dernières années. Il le doit principalement à la multiplication des offres de croisières bon marché. La croisière maritime est devenue accessible financièrement au plus grand nombre et elle contribue également au rayonnement international d’une ville portuaire en attirant des touristes venant du monde entier. En 2018, 28,2 millions de passagers ont réalisé une croisière soit une croissance de plus de 30% sur les 5 dernières années (source : CLIA, Cruise Lines International Association). La croisière maritime est relativement néfaste pour l’environnement (pollution de l’air, rejets en mer, ...) mais cette activité est très exposée en terme d’image et cherche donc à faire partie des bons élèves, avec par exemple le lancement en octobre 2019 de deux navires (l’Aida Nova et le Costa Smeralda) propulsés au GNL sur les 700 parcourant les mers. Cette fiche offre un apperçu du marché de la croisière en Europe, qui est le second marché mondial, après les caraïbes, avec 7 millions de passagers et un zoom sur le renouveau de la croisière au Havre
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