253 research outputs found

    Restructurations : Regard sur ses répercussions humaines et organisationnelles

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    International audienceThis study has been carried out in a multinational company and which is currently undergoing a restructuring. This analysis puts the emphasis on the human and organizational effects generated by this singular context. Drawing on three theoretical concepts, the aim of this study is to check if a degree of " stress perceived " as high associated with an " organizational support perceived " as weak questions the " affective commitment " of the employees leading to bad outcomes for the company in terms of productivity and efficiency. The results confirm our predictions. Indeed, a correlation between a stress perceived as " pathological " , an organizational support perceived as weak and a moderate affective commitment is to be found for the employees surveyed.Réalisée au sein d'une multinationale en restructuration, cette étude met l'accent sur les répercussions humaines et organisationnelles générées par ce contexte singulier. En conjuguant trois concepts théoriques, l'objectif de cette recherche est de vérifier si un " stress perçu " élevé associé à un faible " soutien organisationnel perçu " remet en question " l'implication organisationnelle affective " des salariés, engendrant fatalement des conséquences négatives en termes de productivité et d'efficacité de l'entreprise. Les résultats obtenus confirment nos prédictions, témoignant d'une corrélation entre un stress perçu dit " pathologique " , un faible soutien organisationnel perçu et une implication organisationnelle affective modérée des salariés sondés

    miRkwood: a tool for the reliable identification of microRNAs in plant genomes

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    International audienceBackground: MicroRNAs (miRNAs) play crucial roles in post-transcriptional regulation of eukaryotic gene expression and are involved in many aspects of plant development. Although several prediction tools are available for metazoan genomes, the number of tools dedicated to plants is relatively limited. Results: Here, we present miRkwood, a user-friendly tool for the identification of miRNAs in plant genomes using small RNA sequencing data. Deep-sequencing data of Argonaute associated small RNAs showed that miRkwood is able to identify a large diversity of plant miRNAs and limits false positive predictions. Moreover, it outperforms current tools such as ShortStack and contrary to ShortStack, miRkwood provides a quality score allowing users to rank miRNA predictions. Conclusion: miRkwood is a very efficient tool for the annotation of miRNAs in plant genomes. It is available as a web server, as a standalone version, as a docker image and as a Galaxy tool

    Exploiting the Richness of Environmental Waterborne Bacterial Species to Find Natural Legionella pneumophila Competitors

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    Legionella pneumophila is one of the most tracked waterborne pathogens and remains an important threat to human health. Despite the use of biocides, L. pneumophila is able to persist in engineered water systems with the help of multispecies biofilms and phagocytic protists. For few years now, high-throughput sequencing methods have enabled a better understanding of microbial communities in freshwater environments. Those unexplored and complex communities compete for nutrients using antagonistic molecules as war weapons. Up to now, few of these molecules were characterized in regards of L. pneumophila sensitivity. In this context, we established, from five freshwater environments, a vast collection of culturable bacteria and investigated their ability to inhibit the growth of L. pneumophila. All bacterial isolates were classified within 4 phyla, namely Proteobacteria (179/273), Bacteroidetes (48/273), Firmicutes (43/273), and Actinobacteria (3/273) according to 16S rRNA coding sequences. Aeromonas, Bacillus, Flavobacterium, and Pseudomonas were the most abundant genera (154/273). Among the 273 isolates, 178 (65.2%) were shown to be active against L. pneumophila including 137 isolates of the four previously cited main genera. Additionally, other less represented genera depicted anti-Legionella activity such as Acinetobacter, Kluyvera, Rahnella, or Sphingobacterium. Furthermore, various inhibition diameters were observed among active isolates, ranging from 0.4 to 9 cm. Such variability suggests the presence of numerous and diverse natural compounds in the microenvironment of L. pneumophila. These molecules include both diffusible secreted compounds and volatile organic compounds, the latter being mainly produced by Pseudomonas strains. Altogether, this work sheds light on unexplored freshwater bacterial communities that could be relevant for the biological control of L. pneumophila in manmade water systems

    Promouvoir l’intermodalitĂ© au quotidien - Les pĂŽles d’échanges en Wallonie

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    Ce vade-mecum s’inscrit dans la continuitĂ© de la recherche ‘Urbanisation des noeuds et mixitĂ© des fonctions’ (CPDT 2017-2018) Ă  laquelle Bianchet Bruno, Blaffart Maud, Claeys Dorian, Dupont Xavier, Maldague Hubert, Regnier-Sakamoto PĂ©nĂ©lope, Van Ngoc HĂ©lĂšne ont participĂ©. Les publications de la CPDT sont consultables et tĂ©lĂ©chargeables sur le site http://cpdt.wallonie.be

    Le gisement paléolithique multistratifié « les Bossats » à Ormesson (Seine-et-Marne, France) : palethnographie ou pùle ethnographie ? Une synthÚse des huit premiÚres années de fouille (2009-2016)

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    editorial reviewedÀ l'Ă©vidence, ces vingt derniĂšres annĂ©es ont vu en France, notamment, se dĂ©velopper en parallĂšle deux nouvelles façons de traiter le PalĂ©olithique supĂ©rieur ancien qui ne sont pas antagonistes d'ailleurs. L'une consiste en une reprise des stratigraphies anciennes dans le Centre et le Sud-Ouest de la France plus spĂ©cifiquement et est associĂ©e Ă  une meilleure redĂ©finition des entitĂ©s culturelles par l'analyse dĂ©taillĂ©e des diffĂ©rentes composantes des systĂšmes techniques. L'autre s'efforce d'appliquer Ă  cette pĂ©riode la dĂ©marche palethnographique, infĂ©odĂ©e historiquement au MagdalĂ©nien du Bassin parisien. Il est vrai que peu de gisements autorisaient ce type d'approche, en raison d'une surface fouillĂ©e insuffisante ou d'un Ă©tat de conservation mĂ©diocre, mais mĂȘme lorsque les dĂ©couvertes s'y prĂȘtaient, le manque de temps et d'investissement freinait Ă©galement toute vellĂ©itĂ© d'une Ă©tude approfondie des sites en question, qui aurait alors dĂ©bouchĂ© sur une lecture palethnographique des lieux et des artefacts. À l'issue d'un PCR menĂ© entre 1999 et 2005, nous pouvions ainsi lĂ©gitimement nous demander si nous Ă©tions capables de jouer les ethnologues du passĂ© pour le PalĂ©olithique supĂ©rieur ancien dans le Bassin parisien. Les sites identifiĂ©s dans le cadre de ce programme de recherche Ă©taient certes nombreux mais reprĂ©sentĂ©s surtout par des dĂ©couvertes de surface, ils ne garantissaient pas un niveau d'analyse digne de ce qui a pu se faire depuis plus de 50 ans Ă  Pincevent ou Ă  Étiolles par exemple (Bodu et al., 2013). Il aura fallu attendre la dĂ©couverte fortuite du gisement de plein-air d'Ormesson « les Bossats » (Seine-et-Marne, prĂšs de Nemours) au dĂ©but des annĂ©es 2000 pour que cette question trouve une rĂ©ponse positive. Concernant, au dĂ©part, presqu'exclusivement des vestiges lithiques et osseux attribuĂ©s au Gravettien, les premiĂšres fouilles menĂ©es en 2009 permirent d'identifier rapidement un second niveau d'occupation, d'attribution moustĂ©rienne. Les campagnes suivantes amenĂšrent Ă  la dĂ©couverte de cinq autres niveaux d'occupation palĂ©olithiques, inĂ©gaux tant pour la surface couverte que pour l'Ă©tat de conservation : un second niveau moustĂ©rien rĂ©sultant vraisemblablement de palimpsestes, un ensemble chĂątelperronien, un autre solutrĂ©en, un quatriĂšme badegoulien et enfin entre ChĂątelperronien et Gravettien, un foyer isolĂ© sans vestiges archĂ©ologiques associĂ©s. Cette stratigraphie palĂ©olithique de plein-air dilatĂ©e est le tĂ©moignage d'une forte occupation du lieu pendant prĂšs de 30 000 ans, ce qui s'explique notamment par la configuration particuliĂšre de la vallĂ©e Ă  cet endroit. À la diversitĂ© chronologique des occupations prĂ©historiques rĂ©pond une diversitĂ© des comportements Ă©conomiques et techniques au sein des diffĂ©rentes sphĂšres d'activitĂ©s mais Ă©galement des habitudes spatiales diffĂ©rentes. À l'issue des huit premiĂšres annĂ©es de fouille (2009-2016), le site d'Ormesson « les Bossats » permet ainsi de dĂ©velopper une approche dĂ©taillĂ©e des comportements techniques, Ă©conomiques, spatiaux de groupes culturels distincts ayant vĂ©cu durant 30 000 ans dans un cadre gĂ©omorphologique et plus globalement naturel, relativement identique. DĂ©passant le jeu de mot facile « palethnographie ou pĂąle ethnographie ? » Ă  Ormesson « les Bossats », nous proposons ici quelques Ă©lĂ©ments de rĂ©ponse

    Non-Invasive Exploration of Neonatal Gastric Epithelium by Using Exfoliated Epithelial Cells

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    Background & Aims: In preterm infants, exfoliated gastric epithelial cells can be retrieved from aspirates sampled through the naso-gastric feeding tube. Our aims were to determine (1) whether the recovery of exfoliated cells is feasible at any time from birth through the removal of the nasogastric tube, (2) whether they can be grown in culture in vitro, and (3) whether the physiological state of exfoliated cells expressing H+/K+-ATPases reflects that of their counterparts remaining in situ at the surface of the gastric epithelium in neonatal rat pups. Methods: In infants, gastric fluid aspirates were collected weekly after birth or every 3 hours over 24-h periods, and related to clinical parameters (Biocollection PROG/09/18). In rat pups submitted to a single fasting/refeeding cycle, we explored circadian exfoliation with the cellular counter-parts in the gland. All samples were analyzed by confocal imaging and Enzyme-Linked Immunosorbent Assay. Results: Epithelial cells were identified by microscopy using membrane-bound anti-H+/K+ ATPases antibody, assessed for nucleus integrity, and the expression of selected proteins (autophagy, circadian clock). On 34 infants, the H+/K+-ATPasepositive cells were consistently found quiescent, regardless of gestational age and feeding schedule from day-5 of life to the day of removal of the naso-gastric tube. By logistic regression analysis, we did find a positive correlation between the intensity of exfoliation (cellular loss per sample) and the postnatal age (p,0.001). The H+/K+ ATPase-positive cell

    Kinetics and persistence of the cellular and humoral immune responses to BNT162b2 mRNA vaccine in SARS-CoV-2-naive and -experienced subjects

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    Background: Understanding and measuring the individual level of immune protection and its persistence at both humoral and cellular levels after SARS-CoV-2 vaccination is mandatory for the management of the vaccination booster campaign. Our prospective study was designed to assess the immunogenicity of the BNT162b2 mRNA vaccine in triggering the humoral and the cellular immune response in healthcare workers up to 6 months after two doses vaccination. Methods: This prospective study enrolled 208 healthcare workers from the LiĂšge University Hospital (CHU) of LiĂšge in Belgium. All participants received two doses of BioNTech/Pfizer COVID-19 vaccine (BNT162b2). Fifty participants were SARS-CoV-2 experienced (self-reported SARS-CoV-2 infection) and 158 were naĂŻve (no reported SARS-CoV-2 infection) before the vaccination. Blood sampling was performed at the day of the first (T0) and second (T1) vaccine doses administration, then at 2 weeks (T2), 4 weeks (T3) and 6 months (T4) after the 1st vaccine dose administration. A total of 1024 blood samples were collected. All samples were tested for the presence of anti-Spike antibodies using DiaSorin LIAISON SARS-CoV-2 TrimericS IgG assay. Neutralizing antibodies against the SARS-CoV-2 Wuhan-like variant strain were quantified in all samples using a Vero E6 cell-based neutralization-based assay. Cell-mediated immune response was evaluated at T4 on 80 participants by measuring the secretion of IFN- on peripheral blood lymphocytes using the QuantiFERON Human IFN- SARS-CoV-2, Qiagen. All participants were monitored on weekly-basis for the novo SARS-COV-2 infection for 4 weeks after the 1st vaccine dose administration. We analyzed separately the naĂŻve and experienced participants. Findings: We found that anti-spike antibodies and neutralization capacity levels were significantly higher in SARS-CoV-2 experienced healthcare workers (HCWs) compared to naĂŻve HCWs at all time points analyzed. Cellular immune response was similar in the two groups six months following 2nd dose of the vaccine. Reassuringly, most participants had a detectable cellular immune response to SARS-CoV-2 six months after vaccination. Besides the impact of SARS-CoV-2 infection history on immune response to BNT162b2 mRNA vaccine, we observed a significant negative correlation between age and persistence of humoral response. Cellular immune response was, however, not significantly correlated to age, although a trend towards a negative impact of age was observed. Conclusions: Our data strengthen previous findings demonstrating that immunization through vaccination combined with natural infection is better than 2 vaccine doses immunization or natural infection alone. It may have implications for personalizing mRNA vaccination regimens used to prevent severe COVID-19 and reduce the impact of the pandemic on the healthcare system. More specifically, it may help prioritizing vaccination, including for the deployment of booster doses

    Construction and characterization of two BAC libraries representing a deep-coverage of the genome of chicory (Cichorium intybus L., Asteraceae)

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    <p>Abstract</p> <p>Background</p> <p>The Asteraceae represents an important plant family with respect to the numbers of species present in the wild and used by man. Nonetheless, genomic resources for Asteraceae species are relatively underdeveloped, hampering within species genetic studies as well as comparative genomics studies at the family level. So far, six BAC libraries have been described for the main crops of the family, <it>i.e</it>. lettuce and sunflower. Here we present the characterization of BAC libraries of chicory (<it>Cichorium intybus </it>L.) constructed from two genotypes differing in traits related to sexual and vegetative reproduction. Resolving the molecular mechanisms underlying traits controlling the reproductive system of chicory is a key determinant for hybrid development, and more generally will provide new insights into these traits, which are poorly investigated so far at the molecular level in Asteraceae.</p> <p>Findings</p> <p>Two bacterial artificial chromosome (BAC) libraries, CinS2S2 and CinS1S4, were constructed from <it>Hin</it>dIII-digested high molecular weight DNA of the contrasting genotypes C15 and C30.01, respectively. C15 was hermaphrodite, non-embryogenic, and <it>S</it><sub>2</sub><it>S</it><sub>2 </sub>for the <it>S</it>-locus implicated in self-incompatibility, whereas C30.01 was male sterile, embryogenic, and <it>S</it><sub>1</sub><it>S</it><sub>4</sub>. The CinS2S2 and CinS1S4 libraries contain 89,088 and 81,408 clones. Mean insert sizes of the CinS2S2 and CinS1S4 clones are 90 and 120 kb, respectively, and provide together a coverage of 12.3 haploid genome equivalents. Contamination with mitochondrial and chloroplast DNA sequences was evaluated with four mitochondrial and four chloroplast specific probes, and was estimated to be 0.024% and 1.00% for the CinS2S2 library, and 0.028% and 2.35% for the CinS1S4 library. Using two single copy genes putatively implicated in somatic embryogenesis, screening of both libraries resulted in detection of 12 and 13 positive clones for each gene, in accordance with expected numbers.</p> <p>Conclusions</p> <p>This indicated that both BAC libraries are valuable tools for molecular studies in chicory, one goal being the positional cloning of the <it>S</it>-locus in this Asteraceae species.</p

    Characterizing Atmospheric Transport Pathways to Antarctica and the Remote Southern Ocean Using Radon-222

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    We discuss remote terrestrial influences on boundary layer air over the Southern Ocean and Antarctica, and the mechanisms by which they arise, using atmospheric radon observations as a proxy. Our primary motivation was to enhance the scientific community’s ability to understand and quantify the potential effects of pollution, nutrient or pollen transport from distant land masses to these remote, sparsely instrumented regions. Seasonal radon characteristics are discussed at 6 stations (Macquarie Island, King Sejong, Neumayer, Dumont d’Urville, Jang Bogo and Dome Concordia) using 1–4 years of continuous observations. Context is provided for differences observed between these sites by Southern Ocean radon transects between 45 and 67°S made by the Research Vessel Investigator. Synoptic transport of continental air within the marine boundary layer (MBL) dominated radon seasonal cycles in the mid-Southern Ocean site (Macquarie Island). MBL synoptic transport, tropospheric injection, and Antarctic outflow all contributed to the seasonal cycle at the sub-Antarctic site (King Sejong). Tropospheric subsidence and injection events delivered terrestrially influenced air to the Southern Ocean MBL in the vicinity of the circumpolar trough (or “Polar Front”). Katabatic outflow events from Antarctica were observed to modify trace gas and aerosol characteristics of the MBL 100–200 km off the coast. Radon seasonal cycles at coastal Antarctic sites were dominated by a combination of local radon sources in summer and subsidence of terrestrially influenced tropospheric air, whereas those on the Antarctic Plateau were primarily controlled by tropospheric subsidence. Separate characterization of long-term marine and katabatic flow air masses at Dumont d’Urville revealed monthly mean differences in summer of up to 5 ppbv in ozone and 0.3 ng m-3 in gaseous elemental mercury. These differences were largely attributed to chemical processes on the Antarctic Plateau. A comparison of our observations with some Antarctic radon simulations by global climate models over the past two decades indicated that: (i) some models overestimate synoptic transport to Antarctica in the MBL, (ii) the seasonality of the Antarctic ice sheet needs to be better represented in models, (iii) coastal Antarctic radon sources need to be taken into account, and (iv) the underestimation of radon in subsiding tropospheric air needs to be investigated
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