60 research outputs found

    Biological flora of Central Europe: Cyperus esculentus L

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    This paper presents information on all aspects of the biology of Cyperus esculentus L. (yellow nutsedge) and deals with its taxonomy, morphology, genetic diversity, distribution, habitat requirements, ecology and life cycle, with special emphasis on uses and cultivation, history of introduction, impact and management in Europe. C. esculentus is a tuber geophyte and most likely originates from the Mediterranean and Southwest Asia. It is a variable plant and four wild-type varieties are presently recognized, in addition to a cultivated form. C. esculentus reproduces primarily by its underground tubers, although abundant seeds are produced. In temperate climates, tubers usually sprout in late spring and the plant withers at the beginning of the winter. C. esculentus is only cultivated in the ValĂšncia region in Spain. Invasion foci emerged across Europe at the beginning of the 1980s and at present, C. esculentus is most abundant on arable land and in ruderal habitats, followed by riverine vegetation. In heavily infested regions of Europe, C. esculentus causes substantial yield losses in field crops and although different management strategies are available, C. esculentus remains difficult to control.Follak, S.; Belz, R.; Bohren, C.; Castro, OD.; Guacchio, ED.; Pascual-Seva, N.; Schwarz, M.... (2016). Biological flora of Central Europe: Cyperus esculentus L. Perspectives in Plant Ecology, Evolution and Systematics. 23:33-51. doi:10.1016/j.ppees.2016.09.003S33512

    Biological flora of Central europe: Baldellia ranunculoides (Alismataceae)

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    Baldellia ranunculoides (L.) Parl. (Alismataceae) is a taxonomically problematic aquatic plant with an historically ill-defined distribution and global conservation status. This paper finds morphological, ecological and molecular evidence for two distinct taxa, probably best described as subspecies: (1) B. ranunculoides subsp. ranunculoides and (2) B. ranunculoides subsp. repens and provides detailed distribution data on their overlapping range, in different habitats, across the cool, high rainfall areas of western Europe and west Mediterranean. The two subspecies are amongst the relatively large number of threatened European and north Africa aquatic plants and this paper provides a systematic review of their relative conservation pressures and management needs, with particular emphasis on the status of both taxa in central Europe. Other observations indicate probable evolutionary relationships within B. ranunculoides s.l. and its associated taxa and the review points out where these and other research topics could potentially be pursued

    Identification of additional risk loci for stroke and small vessel disease: a meta-analysis of genome-wide association studies

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    BACKGROUND: Genetic determinants of stroke, the leading neurological cause of death and disability, are poorly understood and have seldom been explored in the general population. Our aim was to identify additional loci for stroke by doing a meta-analysis of genome-wide association studies. METHODS: For the discovery sample, we did a genome-wide analysis of common genetic variants associated with incident stroke risk in 18 population-based cohorts comprising 84 961 participants, of whom 4348 had stroke. Stroke diagnosis was ascertained and validated by the study investigators. Mean age at stroke ranged from 45·8 years to 76·4 years, and data collection in the studies took place between 1948 and 2013. We did validation analyses for variants yielding a significant association (at p<5 × 10(-6)) with all-stroke, ischaemic stroke, cardioembolic ischaemic stroke, or non-cardioembolic ischaemic stroke in the largest available cross-sectional studies (70 804 participants, of whom 19 816 had stroke). Summary-level results of discovery and follow-up stages were combined using inverse-variance weighted fixed-effects meta-analysis, and in-silico lookups were done in stroke subtypes. For genome-wide significant findings (at p<5 × 10(-8)), we explored associations with additional cerebrovascular phenotypes and did functional experiments using conditional (inducible) deletion of the probable causal gene in mice. We also studied the expression of orthologs of this probable causal gene and its effects on cerebral vasculature in zebrafish mutants. FINDINGS: We replicated seven of eight known loci associated with risk for ischaemic stroke, and identified a novel locus at chromosome 6p25 (rs12204590, near FOXF2) associated with risk of all-stroke (odds ratio [OR] 1·08, 95% CI 1·05-1·12, p=1·48 × 10(-8); minor allele frequency 21%). The rs12204590 stroke risk allele was also associated with increased MRI-defined burden of white matter hyperintensity-a marker of cerebral small vessel disease-in stroke-free adults (n=21 079; p=0·0025). Consistently, young patients (aged 2-32 years) with segmental deletions of FOXF2 showed an extensive burden of white matter hyperintensity. Deletion of Foxf2 in adult mice resulted in cerebral infarction, reactive gliosis, and microhaemorrhage. The orthologs of FOXF2 in zebrafish (foxf2b and foxf2a) are expressed in brain pericytes and mutant foxf2b(-/-) cerebral vessels show decreased smooth muscle cell and pericyte coverage. INTERPRETATION: We identified common variants near FOXF2 that are associated with increased stroke susceptibility. Epidemiological and experimental data suggest that FOXF2 mediates this association, potentially via differentiation defects of cerebral vascular mural cells. Further expression studies in appropriate human tissues, and further functional experiments with long follow-up periods are needed to fully understand the underlying mechanisms

    Le jardinage-habitant et la transition Ă©cologique des petites villes sous influence mĂ©tropolitaine : le cas de Magny-en-Vexin, Île-de-France, France

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    International audienceSituĂ©e Ă  une heure de Paris et Ă  seulement 25 kilomĂštres de Cergy, Magny-en-Vexin est une commune du Val-d’Oise comptant prĂšs de 5 600 habitants. EnvironnĂ© de grandes cultures et de forĂȘts, Magny s’inscrit dans un Parc naturel rĂ©gional et est traversĂ© par l’Aubette, une riviĂšre autrefois amĂ©nagĂ©e pour les besoins domestiques et Ă©conomiques de la ville, Ă  la base du dĂ©veloppement de son artisanat et de sa petite industrie (moulins, tanneries, chaiseries, sucrerie). Du faisceau d’activitĂ©s humaines jadis rassemblĂ©es au fil de l’eau, les jardins sont parmi les derniers usages. Ils permettent de recrĂ©er un dialogue avec les habitants et leurs Ă©lus pas seulement prĂ©occupĂ©s par le risque d’inondation d’une riviĂšre dont on a voulu trop artificialiser le cours et les paysages. Les jardiniers sont les acteurs de nouvelles pratiques qui contribuent Ă  redĂ©finir un sens mais aussi un rapport intime Ă  ces espaces rivulaires dont on cherche Ă  reconnaĂźtre « la valeur des lieux ». Au-delĂ  de la clĂŽture et de l’objet qui sĂ©pare, les jardins semblent constituer aujourd’hui un nouveau levier d’appropriation et de renouvellement d’un paysage historique ; ils participent Ă  revitaliser un centre bourg et Ă  mettre Ă  jour une diversitĂ© de formes et de pratiques socio-spatiales induisant de nouveaux regards ainsi que de nouveaux agissements individuels et collectifs.À partir d’enquĂȘtes et d’observations in situ rĂ©alisĂ©es dans le cadre du programme de recherche action Popsu Territoires « Magny-en-Vexin, une petite ville sous influence mĂ©tropolitaine
 Ă  la recherche de son territoire perdu », cette proposition entend dĂ©montrer que les jardins reprĂ©sentent une opportunitĂ© pour repenser les bases d’un projet urbain oĂč l’avenir se dessine en commun

    Le jardinage-habitant et la transition Ă©cologique des petites villes sous influence mĂ©tropolitaine : le cas de Magny-en-Vexin, Île-de-France, France

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    SituĂ©e Ă  une heure de Paris et Ă  seulement 25 kilomĂštres de Cergy, Magny-en-Vexin est une commune du Val-d’Oise comptant prĂšs de 5 600 habitants. EnvironnĂ© de grandes cultures et de forĂȘts, Magny s’inscrit dans un Parc naturel rĂ©gional et est traversĂ© par l’Aubette, une riviĂšre autrefois amĂ©nagĂ©e pour les besoins domestiques et Ă©conomiques de la ville, Ă  la base du dĂ©veloppement de son artisanat et de sa petite industrie (moulins, tanneries, chaiseries, sucrerie). Du faisceau d’activitĂ©s humaines jadis rassemblĂ©es au fil de l’eau, les jardins sont parmi les derniers usages. Ils permettent de recrĂ©er un dialogue avec les habitants et leurs Ă©lus pas seulement prĂ©occupĂ©s par le risque d’inondation d’une riviĂšre dont on a voulu trop artificialiser le cours et les paysages. Les jardiniers sont les acteurs de nouvelles pratiques qui contribuent Ă  redĂ©finir un sens mais aussi un rapport intime Ă  ces espaces rivulaires dont on cherche Ă  reconnaĂźtre « la valeur des lieux ». Au-delĂ  de la clĂŽture et de l’objet qui sĂ©pare, les jardins semblent constituer aujourd’hui un nouveau levier d’appropriation et de renouvellement d’un paysage historique ; ils participent Ă  revitaliser un centre bourg et Ă  mettre Ă  jour une diversitĂ© de formes et de pratiques socio-spatiales induisant de nouveaux regards ainsi que de nouveaux agissements individuels et collectifs.À partir d’enquĂȘtes et d’observations in situ rĂ©alisĂ©es dans le cadre du programme de recherche action Popsu Territoires « Magny-en-Vexin, une petite ville sous influence mĂ©tropolitaine... Ă  la recherche de son territoire perdu », cette proposition entend dĂ©montrer que les jardins reprĂ©sentent une opportunitĂ© pour repenser les bases d’un projet urbain oĂč l’avenir se dessine en commun.Located one hour from Paris and only 25 kilometers from Cergy, Magny-en-Vexin is a commune in the Val-d’Oise department (France) with a population of nearly 5,600. Surrounded by fields and forests, Magny is part of a regional nature park and is crossed by the Aubette, a river that was once used for the town’s domestic and economic needs, and was the basis for the development of its crafts and small-scale industry (mills, tanneries, chairs factory, sugar mills). Of the bundle of human activities once gathered along the water, the gardens are among the last uses. They enable a dialogue to be recreated with the inhabitants and their elected representatives, who are not only concerned about the risk of flooding from a river whose course and landscapes have been overly artificialized. The gardeners are the actors of new practices that contribute to redefining a meaning but also an intimate relationship with these river spaces for which we are trying to recognize “the value of the place”. Beyond the fence and the object that separates, the gardens seem to constitute today a new lever of appropriation and renewal of a historical landscape; they participate in the revitalization of a town center and bring to light a diversity of socio-spatial forms and practices inducing new looks as well as new individual and collective actions.Based on surveys and in situ observations carried out as part of the Popsu Territoires action research program “Magny-en-Vexin, a small town under metropolitan influence... in search of its lost territory”, this proposal aims to demonstrate that gardens represent an opportunity to rethink the foundations of an urban project where the future is drawn in common

    Trajectoire paysagÚre des digues fluviales confrontées aux risques cÎtiers : le cas des marais de la Dives (Calvados, France)

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    International audienceEn territoire cĂŽtier, les espaces agricoles endiguĂ©s sont aujourd’hui menacĂ©s par une conjonction de facteurs, qui en compromettent l’existence parfois millĂ©naire. Dans les marais de la Dives (Calvados, France), le transfert de la compĂ©tence Gestion des milieux aquatiques et prĂ©vention des inondations (GEMAPI) ainsi que le changement climatique, ajoutent Ă  l’incertitude du devenir de digues dĂ©jĂ  en mauvais Ă©tat. À partir d’une analyse gĂ©ohistorique et d’une enquĂȘte menĂ©e auprĂšs des habitants dans le cadre du programme de recherche ANR DIGUES, cette contribution interroge les scĂ©narios d’évolution possibles des digues, au regard de la trajectoire paysagĂšre du marais. Les rĂ©sultats amĂšnent Ă  nuancer le seul critĂšre du coĂ»t Ă©conomique du maintien des ouvrages, en montrant que l’abandon des digues des marais pourrait en rĂ©alitĂ© accentuer la vulnĂ©rabilitĂ© du littoral urbanisĂ©

    Trajectoire paysagÚre des digues fluviales confrontées aux risques cÎtiers : le cas des marais de la Dives (Calvados, France)

    No full text
    International audienceEn territoire cĂŽtier, les espaces agricoles endiguĂ©s sont aujourd’hui menacĂ©s par une conjonction de facteurs, qui en compromettent l’existence parfois millĂ©naire. Dans les marais de la Dives (Calvados, France), le transfert de la compĂ©tence Gestion des milieux aquatiques et prĂ©vention des inondations (GEMAPI) ainsi que le changement climatique, ajoutent Ă  l’incertitude du devenir de digues dĂ©jĂ  en mauvais Ă©tat. À partir d’une analyse gĂ©ohistorique et d’une enquĂȘte menĂ©e auprĂšs des habitants dans le cadre du programme de recherche ANR DIGUES, cette contribution interroge les scĂ©narios d’évolution possibles des digues, au regard de la trajectoire paysagĂšre du marais. Les rĂ©sultats amĂšnent Ă  nuancer le seul critĂšre du coĂ»t Ă©conomique du maintien des ouvrages, en montrant que l’abandon des digues des marais pourrait en rĂ©alitĂ© accentuer la vulnĂ©rabilitĂ© du littoral urbanisĂ©
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