12 research outputs found
Operating a full tungsten actively cooled tokamak: overview of WEST first phase of operation
WEST is an MA class superconducting, actively cooled, full tungsten (W) tokamak, designed to operate in long pulses up to 1000 s. In support of ITER operation and DEMO conceptual activities, key missions of WEST are: (i) qualification of high heat flux plasma-facing components in integrating both technological and physics aspects in relevant heat and particle exhaust conditions, particularly for the tungsten monoblocks foreseen in ITER divertor; (ii) integrated steady-state operation at high confinement, with a focus on power exhaust issues. During the phase 1 of operation (2017â2020), a set of actively cooled ITER-grade plasma facing unit prototypes was integrated into the inertially cooled W coated startup lower divertor. Up to 8.8 MW of RF power has been coupled to the plasma and divertor heat flux of up to 6 MW mâ2 were reached. Long pulse operation was started, using the upper actively cooled divertor, with a discharge of about 1 min achieved. This paper gives an overview of the results achieved in phase 1. Perspectives for phase 2, operating with the full capability of the device with the complete ITER-grade actively cooled lower divertor, are also described
Periodontal approach of impacted and retained maxillary anterior teeth
Treatment of the impacted and retained teeth is a multidisciplinary approach involving close cooperation between periodontist and orthodontist.
Clinical and radiographic examination leading subsequently to diagnosis, remain the most important prerequisites permitting appropriate treatment.
Several surgical techniques are available to uncover impacted/retained tooth according to their position within the osseous and dental environment.
Moreover, to access to the tooth and to bond an orthodontic anchorage, the surgical techniques used during the surgical exposure must preserve the periodontium integrity. These surgical techniques are based on tissue manipulations derived from periodontal plastic surgery, permitting to establish and maintain long-term periodontal health
Abord parodontal des dents maxillaires antérieures incluses et retenues
Le traitement des dents incluses et retenues est une dĂ©marche pluridisciplinaire impliquant une coopĂ©ration Ă©troite entre parodontiste et orthodontiste. Le temps le plus important de la gestion de ces cas reste le diagnostic et par consĂ©quent lâexamen clinique et radiologique qui le permettent. En fonction de la position de la dent, au sein des structures osseuses et dentaires environnantes, diverses techniques chirurgicales permettront le dĂ©gagement. Outre lâaccĂšs Ă la dent et la possibilitĂ© de coller un ancrage orthodontique, les techniques opĂ©ratoires mises en place lors du dĂ©gagement chirurgical doivent respecter lâintĂ©gritĂ© du parodonte de la dent dĂ©gagĂ©e, ainsi que le parodonte des dents adjacentes. Lâensemble de ces techniques fait rĂ©fĂ©rence Ă la chirurgie plastique parodontale pour favoriser le maintien de la santĂ© parodontale Ă long terme
The andromonoecious sex determination gene predates the separation of Cucumis and Citrullus genera
PubMedID: 27171236Understanding the evolution of sex determination in plants requires the cloning and the characterization of sex determination genes. Monoecy is characterized by the presence of both male and female flowers on the same plant. Andromonoecy is characterized by plants carrying both male and bisexual flowers. In watermelon, the transition between these two sexual forms is controlled by the identity of the alleles at the A locus. We previously showed, in two Cucumis species, melon and cucumber, that the transition from monoecy to andromonoecy results from mutations in 1-aminocyclopropane-1-carboxylic acid synthase (ACS) gene, ACS-7/ACS2. To test whether the ACS-7/ACS2 function is conserved in cucurbits, we cloned and characterized ClACS7 in watermelon. We demonstrated co-segregation of ClACS7, the homolog of CmACS-7/CsACS2, with the A locus. Sequence analysis of ClACS7 in watermelon accessions identified three ClACS7 isoforms, two in andromonoecious and one in monoecious lines. To determine whether the andromonoecious phenotype is due to a loss of ACS enzymatic activity, we expressed and assayed the activity of the three protein isoforms. Like in melon and cucumber, the isoforms from the andromonoecious lines showed reduced to no enzymatic activity and the isoform from the monoecious line was active. Consistent with this, the mutations leading andromonoecy were clustered in the active site of the enzyme. Based on this, we concluded that active ClACS7 enzyme leads to the development of female flowers in monoecious lines, whereas a reduction of enzymatic activity yields hermaphrodite flowers. ClACS7, like CmACS-7/CsACS2 in melon and cucumber, is highly expressed in carpel primordia of buds determined to develop carpels and not in male flowers. Based on this finding and previous investigations, we concluded that the monoecy gene, ACS7, likely predated the separation of the Cucumis and Citrullus genera. © 2016 Boualem et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.European Research Council Agence Nationale de la Recherche Saudi Pharmaceutical Society: ANR-10-LABX-40 ANR-11-BSV7-0024This work was supported by BAP department in INRA, the grant Program Saclay Plant Sciences (SPS, ANR-10-LABX-40) for ABo and ABe, the Agence Nationale de la Recherche grant MELODY (ANR-11-BSV7-0024) for ABo, ABe and CD and the European Research Council grant (ERC-SEXYPARTH) for ABe. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. We thank P. Audigier and N. Giovinazzo for plant care and V. Rittener for technical assistance. We thank M. Chatterjee for helpful discussions on the manuscript. We thank J. Fauve for providing watermelon andromonoecious accessions. This work was supported by BAP department in INRA, the grants Program Saclay Plant Sciences (SPS, ANR-10-LABX-40), ANR MELODY (ANR-11-BSV7-0024) and the European Research Council (ERC-SEXYPARTH)
Field trials reveal ecotype-specific responses to mycorrhizal inoculation in rice
The overuse of agricultural chemicals such as fertilizer and pesticides aimed at increasing crop yield results in environmental damage, particularly in the Sahelian zone where soils are fragile. Crop inoculation with beneficial soil microbes appears as a good alternative for reducing agricultural chemical needs, especially for small farmers. This, however, requires selecting optimal combinations of crop varieties and beneficial microbes tested in field conditions. In this study, we investigated the response of rice plants to inoculation with arbuscular mycorrhizal fungi (AMF) and plant growth promoting bacteria (PGPB) under screenhouse and field conditions in two consecutive seasons in Senegal. Evaluation of single and mixed inoculations with AMF and PGPB was conducted on rice (Oryza sativa) variety Sahel 202, on sterile soil under screenhouse conditions. We observed that inoculated plants, especially plants treated with AMF, grew taller, matured earlier and had higher grain yield than the non-inoculated plants. Mixed inoculation trials with two AMF strains were then conducted under irrigated field conditions with four O. sativa varieties, two O. glaberrima varieties and two interspecific NERICA varieties, belonging to 3 ecotypes (upland, irrigated, and rainfed lowland). We observed that the upland varieties had the best responses to inoculation, especially with regards to grain yield, harvest index and spikelet fertility. These results show the potential of using AMF to improve rice production with less chemical fertilizers and present new opportunities for the genetic improvement in rice to transfer the ability of forming beneficial rice-microbe associations into high yielding varieties in order to increase further rice yield potentials
Actinorhizal signaling molecules : Frankia root hair deforming factor shares properties with NIN inducing factor
Actinorhizal plants are able to establish a symbiotic relationship with Frankia bacteria leading to the formation of root nodules. The symbiotic interaction starts with the exchange of symbiotic signals in the soil between the plant and the bacteria. This molecular dialog involves signaling molecules that are responsible for the specific recognition of the plant host and its endosymbiont. Here we studied two factors potentially involved in signaling between Frankia casuarinae and its actinorhizal host Casuarina glauca: (1) the Root Hair Deforming Factor (CgRHDF) detected using a test based on the characteristic deformation of C. glauca root hairs inoculated with F. casuarinae and (2) a NIN activating factor (CgNINA) which is able to activate the expression of CgNIN, a symbiotic gene expressed during preinfection stages of root hair development. We showed that CgRHDF and CgNINA corresponded to small thermoresistant molecules. Both factors were also hydrophilic and resistant to a chitinase digestion indicating structural differences from rhizobial Nod factors (NFs) or mycorrhizal Myc-LCOs. We also investigated the presence of CgNINA and CgRHDF in 16 Frankia strains representative of Frankia diversity. High levels of root hair deformation (RHD) and activation of ProCgNIN were detected for Casuarina-infective strains from clade Ic and closely related strains from clade Ia unable to nodulate C. glauca. Lower levels were present for distantly related strains belonging to clade III. No CgRHDF or CgNINA could be detected for Frankia coriariae (Clade II) or for uninfective strains from clade IV
Operating a full tungsten actively cooled tokamak: overview of WEST first phase of operation
International audienceAbstract WEST is an MA class superconducting, actively cooled, full tungsten (W) tokamak, designed to operate in long pulses up to 1000 s. In support of ITER operation and DEMO conceptual activities, key missions of WEST are: (i) qualification of high heat flux plasma-facing components in integrating both technological and physics aspects in relevant heat and particle exhaust conditions, particularly for the tungsten monoblocks foreseen in ITER divertor; (ii) integrated steady-state operation at high confinement, with a focus on power exhaust issues. During the phase 1 of operation (2017â2020), a set of actively cooled ITER-grade plasma facing unit prototypes was integrated into the inertially cooled W coated startup lower divertor. Up to 8.8 MW of RF power has been coupled to the plasma and divertor heat flux of up to 6 MW m â2 were reached. Long pulse operation was started, using the upper actively cooled divertor, with a discharge of about 1 min achieved. This paper gives an overview of the results achieved in phase 1. Perspectives for phase 2, operating with the full capability of the device with the complete ITER-grade actively cooled lower divertor, are also described