348 research outputs found
CaractĂ©ristiques et spĂ©cificitĂ©s du karst de la Montagne de Reims ; comparaison avec les autres karsts de contact lithostratigraphique de lâest du Bassin parisien
La Montagne de Reims est affectĂ©e par un karst de contact lithostratigraphique Ă lâimage des autres karsts de lâest du Bassin parisien. Comme eux, il est Ă©galement Ă©tagĂ© et sous couverture forestiĂšre. Cependant, il prĂ©sente certaines spĂ©cificitĂ©s : câest un karst de front de cĂŽte qui sâinscrit en milieu crayeux et se trouve perchĂ© au-dessus de la nappe de la craie. Il est Ă©galement accompagnĂ© par des mouvements de terrain de type rotationnel qui conditionnent son Ă©volution.The âMontagne de Reimsâ karst is a karst of lithostratigraphic contact as are others of the eastern Paris Basin. Like them, this karst also occurs at different levels beneath forest cover. However, it has certain specialities: it is a karst of the scarp face developed in Middle Chalk and is perched above the Chalk water table.âIt is also affected by the movements of rotational landslides which condition its evolution.Der Karst der Montagne de Reims ist ein vom lithostratigraphischer Kontaktkarst wie die anderen Karstgebiete des östlichen Pariser Beckens. Wie sie ist er gestuft und unter Waldbedeckung.âDoch zeigt er gewisse Besonderheiten.âEs ist ein Karst der Stufenstirn im Bereich der Kreide ĂŒber dem Grundwasser-spiegel.âEs haben sich aus Rotationsbewegungen im Boden ausgewirkt, welche die Entwicklung des Karsts bedingen
On a species complex, Afzelia, in African forests of economic and ecological interest. A review
The purpose of this review is to provide a knowledge update and a comprehensive literature review of the genus Afzelia, a complex of sister species exploited for their timber in Central Africa. The distribution of Afzelia species in Africa suggests that the tree has made various
adaptations due to ecological factors. However, on the basis of only vegetative criteria, it is difficult to distinguish species in forest inventory, and this could compromise the sustainable management approach promoted by the populations of Central African countries. We show that the genus remains generally understudied, although some of its species are considered by the IUCN as being under threat. Therefore, the ecological and genetic aspects of our investigations should prove relevant to the future cultivation of Afzelia
Identification of Genes Differentially Expressed in Response to Cold in Pisum sativum Using RNA Sequencing Analyses
International audienceLow temperature stress affects growth and development in pea (Pisum sativum L.) and decreases yield. In this study, RNA sequencing time series analyses performed on lines, Champagne frost-tolerant and TĂ©rĂšse frost-sensitive, during a low temperature treatment versus a control condition, led us to identify 4981 differentially expressed genes. Thanks to our experimental design and statistical analyses, we were able to classify these genes into three sets. The first one was composed of 2487 genes that could be related to the constitutive differences between the two lines and were not regulated during cold treatment. The second gathered 1403 genes that could be related to the chilling response. The third set contained 1091 genes, including genes that could be related to freezing tolerance. The identification of differentially expressed genes related to cold, oxidative stress, and dehydration responses, including some transcription factors and kinases, confirmed the soundness of our analyses. In addition, we identified about one hundred genes, whose expression has not yet been linked to cold stress. Overall, our findings showed that both lines have different characteristics for their cold response (chilling response and/or freezing tolerance), as more than 90% of differentially expressed genes were specific to each of them
Les phases dâincision de la vallĂ©e de la Marne entre Joinville et Vitry-le-François(Est du bassin parisien / France)
Lâarticle porte sur lâanalyse de lâincision de la vallĂ©e de la Marne, notamment sur la recherche et lâanalyse des stades dâincision entre Joinville et Vitry-le-François, dans la traversĂ©e du plateau calcaire du Barrois et la dĂ©pression alluviale du Perthois. Le levĂ© de la carte gĂ©omorphologique a permis de mettre en Ă©vidence sept niveaux dâincision visibles aujourdâhui dans le paysage par des formes de versants et/ou de terrasses. Ces sept niveaux peuvent ĂȘtre regroupĂ©s en trois familles de formes dont la construction sâĂ©tale sur la pĂ©riode « plio-quaternaire ». Lâincision totale est de lâordre de 200 m. Par ailleurs, un passage de la Marne vers le nord, en direction de la vallĂ©e de lâAisne via les palĂ©o-vallĂ©es de la Saulx et de lâOrnain, avait Ă©tĂ© envisagĂ© par le fossĂ© tectonique de Cousance et par la ForĂȘt de Trois-Fontaines dĂšs la fin du XIXe siĂšcle. Les levĂ©s effectuĂ©s montrent que dĂšs la fin de la pĂ©riode de construction de la premiĂšre famille de formes, la Marne avait un tracĂ© suivant sa vallĂ©e actuelle en amont deSaint-Dizier. Le fossĂ© de Cousancea donc Ă©tĂ© creusĂ© par le jeu de lâĂ©rosion diffĂ©rentielle. LâhypothĂšse dâun palĂ©o-tracĂ© de la Marne par ce passage paraĂźt donc devoir ĂȘtre abandonnĂ©e.The paper focuses on the analysis of the incision of the valley of the Marne, in particular on research and analysis of incision stages between Joinville and Vitry-le-François, where it traverses the Barrois limestone plateau and the alluvial plain of Perthois. Geomorphological mapping of slopes and/or terrace forms has revealed seven incision levels visible today in the landscape. These seven levels can be subdivised into three groups, the construction of which extends across the âPlio-Quaternaryâ period, with a total amount of incision in the order of 200 m. By the end of the nineteenth century, a northward passage of the Marne, in the direction of the Aisne valley via the palaeovalleys of the Saulx and the Ornain, had been envisaged through the Cousance trough and the « ForĂȘt de Trois Fontaines ». The surveys carried out for this study show that, from the end of the period of construction of the first group of forms, the Marne followed a route along its present valley upstream of Saint-Dizier. The Cousance trough has therefore been cut by the action of differential erosion. The hypothesis of a palaeo-route of the Marne via this passage must therefore be abandoned.Der Artikel handelt von der Analyse der Eintiefung des Marnetals, insbesondere von der Untersuchung und Analyse der Eintiefungsstadien zwischen Joinville und Vitry-le-François im Ăbergang vom Kalkplateau des Barrois zur Alluvial-depression des Perthois. Die Aufnahme der geomorphologischen Karte hat sieben Eintiefungsniveaus deutlich gemacht, die heute in der Landschaft durch Hang- und Terrassenformen sichtbar sind. Diese sieben Niveaus können in drei Formfamilien gruppiert werden, deren Bildung sich ĂŒber die Plio-QuartĂ€r-Periode erstreckt. Die gesamte Eintiefung betrĂ€gt etwa 200 m in der Region. Zudem wurde seit Ende des 19. Jahrhunderts ein Ăbergang der Marne nach Norden in Richtung des Aisnetals ĂŒber die PalĂ€otĂ€ler der Saulx und des Ornain in Betracht gezogen â durch den tektonischen Graben von Cousance und die ForĂȘt des Trois Fontaines. Die Erhebungen zeigen, dass seit dem Ende der Ausbildungsperiode der ersten Formengeneration die Marne einen Verlauf hatte, der dem aktuellen des Tales flussaufwĂ€rts von Saint-Dizier folgt. Der Graben von Cousance wurde also durch das differenzierte Spiel der Erosion eingeschnitten. Die Hypothese von einem alten Verlauf der Marne durch diese Passage muss somit wohl verlassen werden
Les phases dâincision de la vallĂ©e de la Marne entre Joinville et Vitry-le-François(Est du bassin parisien / France)
Lâarticle porte sur lâanalyse de lâincision de la vallĂ©e de la Marne, notamment sur la recherche et lâanalyse des stades dâincision entre Joinville et Vitry-le-François, dans la traversĂ©e du plateau calcaire du Barrois et la dĂ©pression alluviale du Perthois. Le levĂ© de la carte gĂ©omorphologique a permis de mettre en Ă©vidence sept niveaux dâincision visibles aujourdâhui dans le paysage par des formes de versants et/ou de terrasses. Ces sept niveaux peuvent ĂȘtre regroupĂ©s en trois familles de formes dont la construction sâĂ©tale sur la pĂ©riode « plio-quaternaire ». Lâincision totale est de lâordre de 200 m. Par ailleurs, un passage de la Marne vers le nord, en direction de la vallĂ©e de lâAisne via les palĂ©o-vallĂ©es de la Saulx et de lâOrnain, avait Ă©tĂ© envisagĂ© par le fossĂ© tectonique de Cousance et par la ForĂȘt de Trois-Fontaines dĂšs la fin du XIXe siĂšcle. Les levĂ©s effectuĂ©s montrent que dĂšs la fin de la pĂ©riode de construction de la premiĂšre famille de formes, la Marne avait un tracĂ© suivant sa vallĂ©e actuelle en amont deSaint-Dizier. Le fossĂ© de Cousancea donc Ă©tĂ© creusĂ© par le jeu de lâĂ©rosion diffĂ©rentielle. LâhypothĂšse dâun palĂ©o-tracĂ© de la Marne par ce passage paraĂźt donc devoir ĂȘtre abandonnĂ©e.The paper focuses on the analysis of the incision of the valley of the Marne, in particular on research and analysis of incision stages between Joinville and Vitry-le-François, where it traverses the Barrois limestone plateau and the alluvial plain of Perthois. Geomorphological mapping of slopes and/or terrace forms has revealed seven incision levels visible today in the landscape. These seven levels can be subdivised into three groups, the construction of which extends across the âPlio-Quaternaryâ period, with a total amount of incision in the order of 200 m. By the end of the nineteenth century, a northward passage of the Marne, in the direction of the Aisne valley via the palaeovalleys of the Saulx and the Ornain, had been envisaged through the Cousance trough and the « ForĂȘt de Trois Fontaines ». The surveys carried out for this study show that, from the end of the period of construction of the first group of forms, the Marne followed a route along its present valley upstream of Saint-Dizier. The Cousance trough has therefore been cut by the action of differential erosion. The hypothesis of a palaeo-route of the Marne via this passage must therefore be abandoned.Der Artikel handelt von der Analyse der Eintiefung des Marnetals, insbesondere von der Untersuchung und Analyse der Eintiefungsstadien zwischen Joinville und Vitry-le-François im Ăbergang vom Kalkplateau des Barrois zur Alluvial-depression des Perthois. Die Aufnahme der geomorphologischen Karte hat sieben Eintiefungsniveaus deutlich gemacht, die heute in der Landschaft durch Hang- und Terrassenformen sichtbar sind. Diese sieben Niveaus können in drei Formfamilien gruppiert werden, deren Bildung sich ĂŒber die Plio-QuartĂ€r-Periode erstreckt. Die gesamte Eintiefung betrĂ€gt etwa 200 m in der Region. Zudem wurde seit Ende des 19. Jahrhunderts ein Ăbergang der Marne nach Norden in Richtung des Aisnetals ĂŒber die PalĂ€otĂ€ler der Saulx und des Ornain in Betracht gezogen â durch den tektonischen Graben von Cousance und die ForĂȘt des Trois Fontaines. Die Erhebungen zeigen, dass seit dem Ende der Ausbildungsperiode der ersten Formengeneration die Marne einen Verlauf hatte, der dem aktuellen des Tales flussaufwĂ€rts von Saint-Dizier folgt. Der Graben von Cousance wurde also durch das differenzierte Spiel der Erosion eingeschnitten. Die Hypothese von einem alten Verlauf der Marne durch diese Passage muss somit wohl verlassen werden
Handicap et amĂ©nagements raisonnables au travail. Importation et usages dâune catĂ©gorie juridique en France et en Belgique
Management of Epileptic Seizures in Disorders of Consciousness: An International Survey.
peer reviewedEpileptic seizures/post-traumatic epilepsy (ES/PTE) are frequent in persons with brain injuries, particularly for patients with more severe injuries including ones that result in disorders of consciousness (DoC). Surprisingly, there are currently no best practice guidelines for assessment or management of ES in persons with DoC. This study aimed to identify clinician attitudes toward epilepsy prophylaxis, diagnosis and treatment in patients with DoC as well as current practice in regards to the use of amantadine in these individuals. A cross-sectional online survey was sent to members of the International Brain Injury Association (IBIA). Fifty physician responses were included in the final analysis. Withdrawal of antiepileptic drug/anti-seizure medications (AED/ASM) therapy was guided by the absence of evidence of clinical seizure whether or not the AED/ASM was given prophylactically or for actual seizure/epilepsy treatment. Standard EEG was the most frequent diagnostic method utilized. The majority of respondents ordered an EEG if there were concerns regarding lack of neurological progress. AED/ASM prescription was reported to be triggered by the first clinically evident seizure with levetiracetam being the AED/ASM of choice. Amantadine was frequently prescribed although less so in patients with epilepsy and/or EEG based epileptic abnormalities. A minority of respondents reported an association between amantadine and seizure. Longitudinal studies on epilepsy management, epilepsy impact on neurologic prognosis, as well as potential drug effects on seizure risk in persons with DoC appear warranted with the goal of pushing guideline development forward and improving clinical assessment and management of seizures in this unique, albeit challenging, population
Tuning the aggregation behavior of pH-responsive micelles by copolymerization
YesAmphiphilic diblock copolymers, poly(2-(diethylamino)ethyl methacrylate-co-2-(dimethylamino)ethyl methacrylate)-b-poly(2-(dimethylamino)ethyl methacrylate), P(DEAEMA-co-DMAEMA)-b-PDMAEMA with various amounts of DEAEMA have been synthesized by RAFT polymerization. Their micellization in water has been investigated by scattering measurements over a wide pH range. It appeared that the polymers self-assembled into pH sensitive star like micelles. For a given composition, when the pH is varied the extent of aggregation can be tuned reversibly by orders of magnitude. By varying the copolymer composition in the hydrophobic block, the onset and extent of aggregation were shifted with respect to pH. This class of diblock copolymer offers the possibility to select the range of stimuli-responsiveness that is useful for a given application, which can rarely be achieved with conventional diblock copolymers consisting of homopolymeric blocks.European Science Foundation (ESF), Engineering and Physical Sciences Research Council (EPSRC), BP (Firm), Birmingham Science City, Advantage West Midlands (AWM), European Regional Development Fund (ERDF
The R136 star cluster hosts several stars whose individual masses greatly exceed the accepted 150 Msun stellar mass limit
Spectroscopic analyses of H-rich WN5-6 stars within the young star clusters
NGC 3603 and R136 are presented, using archival HST & VLT spectroscopy, & high
spatial resolution near-IR photometry. We derive high T* for the WN stars in
NGC 3603 (T*~42+/-2 kK) & R136 (T*~53+/-3 kK) plus clumping-corrected dM/dt ~
2-5x10^-5 Msun/yr which closely agree with theoretical predictions. These stars
make a disproportionate contribution to the global budget of their host
clusters. R136a1 alone supplies ~7% of N(LyC) of the entire 30 Dor region.
Comparisons with stellar models calculated for the main-sequence evolution of
85-500 Msun suggest ages of ~1.5 Myr & M_init in the range 105 - 170 Msun for 3
systems in NGC 3603, plus 165-320 Msun for 4 stars in R136. Our high stellar
masses are supported by dynamical mass determinations for the components of NGC
3603 A1. We consider the predicted L_X of the R136 stars if they were close,
colliding wind binaries. R136c is consistent with a colliding wind binary
system. However, short period, colliding wind systems are excluded for R136a WN
stars if mass ratios are of order unity. Widely separated systems would have
been expected to harden owing to early dynamical encounters with other massive
stars in such a dense environment. From simulated star clusters, whose
constituents are randomly sampled from the Kroupa IMF, both clusters are
consistent with a tentative upper mass limit of ~300 Msun. The Arches cluster
is either too old, exhibits a deficiency of very massive stars, or more likely
stellar masses have been underestimated - M_init for the most luminous stars in
the Arches cluster approach 200 Msun according to contemporary stellar &
photometric results. The potential for stars greatly exceeding 150 Msun within
metal-poor galaxies suggests that such pair-instability SNe could occur within
the local universe, as has been claimed for SN 2007bi (abridged).Comment: 20 pages, 14 figures, accepted for MNRAS. Version with higher
resolution figures is available from
http://pacrowther.staff.shef.ac.uk/R136.pdf See also
http://www.eso.org/public/news/eso1030/ from Wed 21 from noon (CEST
The GenTree Dendroecological Collection, tree-ring and wood density data from seven tree species across Europe
The dataset presented here was collected by the GenTree project (EU-Horizon 2020), which aims to improve the use of forest genetic resources across Europe by better understanding how trees adapt to their local environment. This dataset of individual tree-core characteristics including ring-width series and whole-core wood density was collected for seven ecologically and economically important European tree species: silver birch (Betula pendula), European beech (Fagus sylvatica), Norway spruce (Picea abies), European black poplar (Populus nigra), maritime pine (Pinus pinaster), Scots pine (Pinus sylvestris), and sessile oak (Quercus petraea). Tree-ring width measurements were obtained from 3600 trees in 142 populations and whole-core wood density was measured for 3098 trees in 125 populations. This dataset covers most of the geographical and climatic range occupied by the selected species. The potential use of it will be highly valuable for assessing ecological and evolutionary responses to environmental conditions as well as for model development and parameterization, to predict adaptability under climate change scenarios
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