9 research outputs found
Chapter 9. Universal DVB-3GPP broadcast layer, an enabler for new business in mobile broadcasting landscape
This chapter aims at promoting the tremendous asset a cooperation of broadband and broadcast deliveries could provide to cope with the data tsunami announced for the mobile access networks. A clever blend of state-of-the-art 3GPP and DVB standards has been designed to provide a broadcast overlay optimized for mobile and operated in conjunction with a broadband unicast access. This chapter highlights the win-win situation for each actor of the multimedia value chain, which should result from such broadband/broadcast cooperation
Occupation des sols et évolution des paysages sur un bassin versant karstique du territoire Pyrénées-Garonne depuis le milieu du 20Úme siÚcle : rÎle potentiel sur la pCO2 des sols et de la qualité des eaux.
National audienceLes hydrosystĂšmes karstiques sont des milieux sensibles aux variations climatiques et aux pressions anthropiques ; ils sont doc dâexcellents modĂšles pour Ă©tudier leurs impacts sur les ressources en eau et sur les cycles biogĂ©ochimiques du carbone et de lâazote, aujourdâhui fortement perturbĂ©s par les changements dâoccupation des terres. Ainsi, la recolonisation par la forĂȘt de terres abandonnĂ©es suite Ă la dĂ©prise agricole favorise la production de matiĂšres organiques dans les sols. Ces changements induisent une augmentation de la pression partielle en CO2 (pCO2) dans les sols et dans les rĂ©seaux karstiques qui favorisent la dissolution des carbonates, mais aussi la production de carbone organique dissous (COD) dans les eaux. Ainsi, une augmentation de la pCO2 dans les cavitĂ©s karstiques (Ek & Godissart, 2014) et une Ă©volution significative de la composition chimique des eaux de drainage ont pu ĂȘtre observĂ©es sur les bassins versants karstiques français (Binet et al., 2020 ; Ulloa-Cedamanos et al., 2020), grĂące aux donnĂ©es collectĂ©es depuis parfois prĂšs de 50 ans dans le cadre du SNO Karst (IR OZCAR). ParallĂšlement Ă ces Ă©volutions, on observe des tendances Ă long terme dans les fluctuations hydroclimatiques (notamment une augmentation de la tempĂ©rature de lâair) et dans lâĂ©volution des paysages avec un abandon progressif des terres cultivĂ©es au profit des friches (Houet et al., 2012). Dans le cadre de la ZA PYGAR, le bassin versant karstique du Baget (13 km2), observatoire du SNO Karst (prĂšs de Moulis, PyrĂ©nĂ©es ariĂ©geoises, entre 500 et 1500 m), a Ă©tĂ© retenu comme site pilote pour dĂ©velopper une mĂ©thode de reconstitution dans le temps de lâĂ©volution des paysagesqui sera mise au regard de lâĂ©volution des dĂ©bits et de la qualitĂ© des eaux, suivis depuis prĂšs de 50 ans. Pour mettre au point la mĂ©thode, nous avons reconstituĂ© lâĂ©volution de lâoccupation des sols depuis 1948, Ă intervalles de 8 ans (Ă lâexception de la pĂ©riode 1947-1963), Ă partir des images satellites depuis les annĂ©es 2000 (SPOT 2 et 4, Sentinel 2) et des photographies aĂ©riennes pour les pĂ©riodes plus anciennes. Cette mĂ©thode a consistĂ© Ă (i) utiliser les donnĂ©es de lâinventaire forestier et de photo-interprĂ©tation (google earth ) pour dĂ©velopper une procĂ©dure de classification de lâoccupation du sol Ă partir dâimages satellites (SPOT, Sentinel) et primitives associĂ©es (texture), (ii) appliquer cette mĂ©thode de classification de lâoccupation du sol au traitement des photos aĂ©riennes anciennes gĂ©o-rĂ©fĂ©rencĂ©es, (iii) dĂ©velopper un indicateur multicritĂšre dâouverture/fermeture du milieu, et (iv) Ă©valuer lâintensitĂ© du changement dâoccupation du sol en termes de surfaces relatives et dâouverture des milieux, de fragmentation et de localisation. Pour la reconstitution dans les temps anciens, les formations vĂ©gĂ©tales ont Ă©tĂ© in fine regroupĂ©es en 3 grands groupes, en fonction de leur couverture au sol, de la densitĂ© de biomasse et de leur rĂŽle dans lâouverture des milieux. Les rĂ©sultats prĂ©senteront la dĂ©marche et la mĂ©thodologie misesen oeuvre, ainsi que lâĂ©volution spatio-temporelle des surfaces occupĂ©es par chaque formation, quantifiĂ©es Ă partir de lâindicateur multicritĂšre dĂ©veloppĂ©
Geomagnetic-assisted stratigraphy and sea surface temperature changes in core MD94-103 (Southern Indian Ocean): possible implications for North-South climatic relationships around H4
International audienceNew records of past sea surface temperatures (SSTs) were derived in the 30-50 kyr B.P. time interval from a core located at 45degreesS in the Southern Indian Ocean, MD94-103. To investigate the climatic phasing between the Southern Indian Ocean, the Greenland and the Antarctic ice, the magnetic signal of core MD94-103 was synchronized at better than millennial accuracy in the vicinity of the Laschamp geomagnetic to a reference record, NAPIS-75, already placed on the GISP2 age model. Coccolithophorid and diatom species abundances both point to a cooling of surface waters during H4. Specific diatoms also indicate lower salinity waters during the same time interval. These observations do not support the idea that the South hemisphere warmed 1.5-2 kyr before the North hemisphere (Nature 394 (1998) 739). Rather, alkenone-derived SSTs suggest that cold conditions have characterized the surface waters in the south latitudes during H4 and H5, and that temperature at evaporation sites contributed to the isotopic events A1 and A2 visible in the isotopic records of central Antarctica (Earth Planet. Sci. Lett. 177 (2000) 219). SSTs obtained from foraminifera assemblages depict somewhat different temperature patterns, possibly indicative of water stratification. (C) 2002 Elsevier Science B.V. All rights reserved
Outils, rĂ©fĂ©rences et mĂ©thodes pour la construction dâun simulateur pour la prĂ©vision du rendement et de la qualitĂ© du tournesol Ă lâĂ©chelle territoriale mobilisant la tĂ©lĂ©dĂ©tection satellitaire
Lâobjectif du projet est de proposer des mĂ©thodes permettant Ă terme de construire un outil de prĂ©vision du rendement et de la qualitĂ© (teneur en huile et teneur en acide olĂ©ique) du tournesol quelques semaines avant sa rĂ©colte, Ă lâĂ©chelle dâun bassin de collecte, Ă lâaide de modĂšles plus ou moins complexes associĂ©s Ă des observations dâĂ©tats de culture (GAI: green area index) acquises par voie satellitaire et supposĂ©es amĂ©liorer la qualitĂ© de prĂ©diction des modĂšles. Il sâagit donc dâidentifier les types de modĂšles les mieux adaptĂ©s Ă la prĂ©vision Ă lâĂ©chelle territoriale parmi une gamme de modĂšles allant des modĂšles corrĂ©latifs les plus simples (Ă une ou deux variables explicatives) aux modĂšles de cultures dynamiques plus ou moins spĂ©cifiques (SUNFLO, SAFY). LâintĂ©rĂȘt des techniques dâassimilation de donnĂ©es de GAI acquises par tĂ©lĂ©dĂ©tection dans les modĂšles dynamiques de culture pour en amĂ©liorer la qualitĂ© de prĂ©diction est Ă©galement Ă©valuĂ©. Des sujets pĂ©riphĂ©riques Ă ces problĂ©matiques, mais incontournables dans lâobjectif dâĂ©laborer les modĂšles et de construire un outil de prĂ©vision opĂ©rationnel, sont Ă©tudiĂ©s: (i) dĂ©termination de mĂ©thodes simples et rapides dâestimation du GAI au sol afin de faciliter la constitution de rĂ©seaux de dispositifs de «vĂ©ritĂ© terrain» nĂ©cessaires Ă la calibration des modĂšles biophysiques, (ii) constitution dâune base de donnĂ©es dâitinĂ©raires techniques, de contextes de culture (donnĂ©es dâentrĂ©e des modĂšles de culture), de production (rendement, teneurs en huile et en acide olĂ©ique: donnĂ©es indispensables pour construire et Ă©valuer les modĂšles de prĂ©diction) et dâimages satellitaires sur plusieurs centaines de parcelles agricoles, (iii) estimation de la date de levĂ©e de la culture (rarement disponible, mais indispensable pour certains modĂšles de culture) par voie satellitaire et (iv) localisation de toutes les parcelles de tournesol dâun territoire en cours de campagne, Ă lâaide de la tĂ©lĂ©dĂ©tection.Le principal rĂ©sultat est que les modĂšles corrĂ©latifs simples Ă une ou deux variables explicatives (GAI maximal au cours du cycle et persistance du GAI pendant la phase reproductive du cycle) paraissent les plus pertinents pour prĂ©dire le rendement Ă lâĂ©chelle de parcelles au sein dâun territoire
Familial predisposition to TP53/complex karyotype MDS and leukemia in DNA repair-deficient xeroderma pigmentosum
International audienc
Aplastic anemia in the elderly: a nationwide survey on behalf of the French Reference Center for Aplastic Anemia
International audienceAplastic anemia is a rare but potentially life-threatening disease that may affect older patients. Data regarding the treatment of aplastic anemia in this ageing population remains scarce. We conducted a retrospective nationwide multicenter study in France to examine current treatments for aplastic anemia patients over 60 years old. Our aims were to evaluate efficacy and tolerance, and to analyze predictive factors for response and survival. Over the course of a decade, 88 patients (median age 68.5 years) were identified in 19 centers, with a median follow up of 2.7 years; 21% had very severe and 36% severe aplastic anemia. We analyzed 184 treatment lines, mostly involving the standard combination of anti-thymocyte globulin and cyclosporine-A (33%), which was also the most frequent first-line treatment (50%). After first-line therapy, 32% of patients achieved a complete response, and 15% a partial response. Responses were significantly better in first line and in patients with good performance status, as well as in those that had followed an anti-thyrnocyte globulin and cyclosporine-A regimen (overall response rate of 70% after first-line treatment). All treatments were well tolerated by patients, including over the age of 70. Three-year survival was 74.7% (median 7.36 years). Age, Charlson comorbidity index and very severe aplastic anemia were independently associated with mortality. Age, per se, is not a limiting factor to aplastic anemia treatment with anti-thymocyte globulin and cyclosporine-A; this regimen should be used as a first-line treatment in elderly patients if they have a good performance status and low comorbidity index score
The Mediterranean region under climate change
This book has been published by Allenvi (French National Alliance for Environmental Research) to coincide with the 22nd Conference of Parties to the United Nations Framework Convention on Climate Change (COP22) in Marrakesh. It is the outcome of work by academic researchers on both sides of the Mediterranean and provides a remarkable scientific review of the mechanisms of climate change and its impacts on the environment, the economy, health and Mediterranean societies. It will also be valuable in developing responses that draw on âscientific evidenceâ to address the issues of adaptation, resource conservation, solutions and risk prevention. Reflecting the full complexity of the Mediterranean environment, the book is a major scientific contribution to the climate issue, where various scientific considerations converge to break down the boundaries between disciplines
Scedosporiosis/lomentosporiosis observational study (SOS): Clinical significance of Scedosporium species identification
International audienceScedosporiosis/lomentosporiosis is a devastating emerging fungal infection. Our objective was to describe the clinical pattern and to analyze whether taxonomic grouping of the species involved was supported by differences in terms of clinical presentations or outcomes. We retrospectively studied cases of invasive scedosporiosis in France from 2005 through 2017 based on isolates characterized by polyphasic approach. We recorded 90 cases, mainly related to Scedosporium apiospermum (n = 48), S. boydii/S. ellipsoideum (n = 20), and Lomentospora prolificans (n = 14). One-third of infections were disseminated, with unexpectedly high rates of cerebral (41%) and cardiovascular (31%) involvement. In light of recent Scedosporium taxonomic revisions, we aimed to study the clinical significance of Scedosporium species identification and report for the first time contrasting clinical presentations between infections caused S. apiospermum, which were associated with malignancies and cutaneous involvement in disseminated infections, and infections caused by S. boydii, which were associated with solid organ transplantation, cerebral infections, fungemia, and early death. The clinical presentation of L. prolificans also differed from that of other species, involving more neutropenic patients, breakthrough infections, fungemia, and disseminated infections. Neutropenia, dissemination, and lack of antifungal prescription were all associated with 3-month mortality. Our data support the distinction between S. apiospermum and S. boydii and between L. prolificans and Scedosporium sp. Our results also underline the importance of the workup to assess dissemination, including cardiovascular system and brain. Lay Summary Scedosporiosis/lomentosporiosis is a devastating emerging fungal infection. Our objective was to describe the clinical pattern and to analyze whether taxonomic grouping of the species involved was supported by differences in terms of clinical presentations or outcomes
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SEIS: Insightâs Seismic Experiment for Internal Structure of Mars
By the end of 2018, 42 years after the landing of the two Viking seismometers on Mars, InSight will deploy onto Marsâ surface the SEIS (Seismic Experiment for Internal Structure) instrument; a six-axes seismometer equipped with both a long-period three-axes Very Broad Band (VBB) instrument and a three-axes short-period (SP) instrument. These six sensors will cover a broad range of the seismic bandwidth, from 0.01 Hz to 50 Hz, with possible extension to longer periods. Data will be transmitted in the form of three continuous VBB components at 2 sample per second (sps), an estimation of the short period energy content from the SP at 1 sps and a continuous compound VBB/SP vertical axis at 10 sps. The continuous streams will be augmented by requested event data with sample rates from 20 to 100 sps. SEIS will improve upon the existing resolution of Vikingâs Mars seismic monitoring by a factor of âŒ2500 at 1 Hz and âŒ200000 at 0.1 Hz. An additional major improvement is that, contrary to Viking, the seismometers will be deployed via a robotic arm directly onto Marsâ surface and will be protected against temperature and wind by highly efficient thermal and wind shielding. Based on existing knowledge of Mars, it is reasonable to infer a moment magnitude detection threshold of âŒ3 at 40â epicentral distance and a potential to detect several tens of quakes and about five impacts per year. In this paper, we first describe the science goals of the experiment and the rationale used to define its requirements. We then provide a detailed description of the hardware, from the sensors to the deployment system and associated performance, including transfer functions of the seismic sensors and temperature sensors. We conclude by describing the experiment ground segment, including data processing services, outreach and education networks and provide a description of the format to be used for future data distribution