546 research outputs found
A Natural Seismic Isolating System: The Buried Mangrove Effects
The Belleplaine test site, located in the island of Guadeloupe (French Lesser
Antilles) includes a three-accelerometer vertical array, designed for liquefac-
tion studies. The seismic response of the soil column at the test site is
computed using three methods: the spectral ratio method using the vertical
array data, a numerical method using the geotechnical properties of the soil
column, and an operative fre- quency domain decomposition (FDD) modal analysis
method. The Belleplaine test site is characterized by a mangrove layer overlaid
by a stiff sandy deposit. This con- figuration is widely found at the border
coast of the Caribbean region, which is exposed to high seismic hazard. We show
that the buried mangrove layer plays the role of an isolation system equivalent
to those usually employed in earthquake engineering aimed at reducing the
seismic shear forces by reducing the internal stress within the structure. In
our case, the flexibility of the mangrove layer reduces the distortion and the
stress in the sandy upper layer, and consequently reduces the potential of
liquefaction of the site
New articulated asteroids (Echinodermata, Asteroidea) and ophiuroids (Echinodermata, Ophiuroidea) from the Late Jurassic (Volgianâ/âTithonian) of central Spitsbergen
The Late JurassicâEarly Cretaceous SlottsmĂžya Member of the Agardhfjellet Formation in central Spitsbergen has yielded two new species of asteroids and two species of ophiuroids, one of which is described as new. Polarasterias janusensis Rousseau & Gale gen. et sp. nov. is a forcipulatid neoasteroid with elongated arms, small disc and very broad ambulacral grooves with narrow adambulacrals. Savignaster septemtrionalis Rousseau & Gale sp. nov. is a pterasterid with well-developed interradial chevrons. The Spitsbergen specimens are the first described articulated material of Savignaster and reveal the overall arrangement of the ambulacral groove ossicles. Ophiogaleus sp. is an ophiacanthid with relatively long jaws and lateral arm plates, with a coarsely reticulate outer surface. Here again, we report the first articulated skeletons of this genus, providing unprecedented insights into the disc morphology. Ophioculina hoybergia Rousseau & Thuy gen. et sp. nov. is an ophiopyrgid with a well-developed arm comb and tentacle pores reduced to within-plate perforations starting at median arm segments. These new finds are important additions to the asterozoan fossil record with regard to their good degree of articulation and the high latitudinal position of the localities. They significantly add to the set of exhaustively known fossil asterozoan taxa which play a key role in the phylogenetic analysis and reconstruction of evolutionary history
Les polymorphismes des gÚnes encodant les protéines apoptotiques Bim et Bax : leur rÎle dans la réponse thérapeutique chez les enfants ayant la leucémie lymphoblastique aiguë
INTRODUCTION Des rĂ©ponses thĂ©rapeutiques variables aux glucocorticoĂŻdes (GCs) sont observĂ©es parmi les patients atteints de la leucĂ©mie lymphoblastique aiguĂ« (LLA). Les protĂ©ines Bax et Bim ont dĂ©jĂ montrĂ© un rĂŽle important dans lâapoptose des cellules leucĂ©miques. Lâexpression de Bax Ă©tait plus basse chez les patients leucĂ©miques rĂ©sistants au mĂ©dicament, de mĂȘme une sensibilitĂ© diminuĂ©e aux GCs a Ă©tĂ© associĂ©e avec une expression rĂ©duite de Bim. La diffĂ©rence dans lâexpression pourrait ĂȘtre due Ă des polymorphismes prĂ©sents dans ces gĂšnes et donc ĂȘtre associĂ©s avec la rĂ©sistance aux GCs. MĂTHODE Dix-huit polymorphismes en rĂ©gions rĂ©gulatrices, 2 polymorphismes exoniques et 7 polymorphismes en rĂ©gion 3âUTR de ces gĂšnes ont Ă©tĂ© analysĂ©s chez les tĂ©moins (n=50) et ont permis de dĂ©terminer un nombre minimal de polymorphismes suffisants pour dĂ©finir les haplotypes (tagSNPs). Ces 8 polymorphismes ont ensuite Ă©tĂ© gĂ©notypĂ©s chez 286 enfants atteints de la LLA et ont Ă©tĂ© testĂ©s pour lâissue de la maladie par lâanalyse de survie. RĂSULTATS Une survie sans Ă©vĂšnement et une survie sans rechute diminuĂ©es ont Ă©tĂ© observĂ©es pour lâhaplotype 3 (p=0,03 et p=0,02). Une survie globale diminuĂ©e a Ă©tĂ© associĂ©e avec lâhomozygotie pour lâallĂšle exonique T298C>T (p=0,03), de mĂȘme que pour les haplotypes 1 et 4 (p=0,04 et p=0,02) du gĂšne Bim. CONCLUSION Les polymorphismes ont Ă©tĂ© associĂ©s avec une survie diminuĂ©e chez des enfants atteints de LLA. Il reste Ă tester dâautres polymorphismes prĂ©sents dans ces deux gĂšnes ainsi quâĂ dĂ©finir leurs fonctions afin de comprendre leurs rĂŽles dans la rĂ©ponse aux GCs.INTRODUCTION Variable therapeutic responses to glucocorticoids (GCs) are observed for acute lymphoblastic leukemia (ALL) patients. Proteins Bax and Bim have already shown to play a major role in mediating GC-induced apoptosis in leukemia cells. Bax expression was lower in drug-resistant leukemia samples; likewise lower sensitivity to GC was associated with reduced Bim expression. The difference in the expression can be due to polymorphisms in these genes and therefore associated to GC resistance. METHOD Eighteen polymorphisms in the regulatory region, two exonic polymorphisms and seven polymorphisms in 3âUTR of these genes were analysed in controls (n=50) and have permitted to determine a minimal number of polymorphisms sufficient to define haplotypes (tagSNPs). These 8 single nucleotide polymorphisms (SNPs) were then genotyped in 286 LLA children and were tested for disease outcome by survival analysis. RESULTS A diminished event free survival and a diminished relapse free survival were observed for haplotype 3 (p=0,03 and p=0,02). A diminished overall survival was associated with the exonic T298C>T allele (p=0,03) and with haplotypes 1 and 4 (p=004 and p=0,02) of Bim gene. CONCLUSION Bax and Bim were associated with a diminished survival in LLA children. We still have to test other polymorphisms located in these genes and to define their functions in order to understand their roles in GC response
Lâaccompagnement parental dans lâapprentissage en lecture des Ă©lĂšves canadiens
Parmi lâensemble des facteurs ayant une influence sur le niveau dâapprentissage des Ă©lĂšves, le statut socio-Ă©conomique familial est celui qui retient souvent lâattention des milieux scientifiques et politiques. Par ailleurs, bon nombre de recherches soulignent que les caractĂ©ristiques familiales ont un impact moindre sur les rĂ©sultats scolaires que les variables du processus familial. Plus spĂ©cifiquement, le soutien affectif des parents semble ĂȘtre la dimension la plus probante en matiĂšre de facteur de protection dans le contexte de la rĂ©ussite scolaire. Nous nous avons voulu savoir : (1) Quelle est la relation entre chacun des modes dâaccompagnement parental Ă©valuĂ© par le Programme international de lâOCDE pour le suivi des aquis des Ă©lĂšves (Pisa 2000) et le rendement en lecture de lâensemble des Ă©lĂšves canadiens? (2) La relation entre chacun de ces modes dâaccompagnement parental et la rĂ©ussite acadĂ©mique est-elle plus importante que celle du niveau socioĂ©conomique familial et dans quelle mesure ces relations sont-elles liĂ©es? La communication culturelle semble ĂȘtre le mode dâaccompagnement parental le plus important. En outre, lâeffet de la communication culturelle et de la communication sociale semblent ĂȘtre en partie expliquĂ© par le niveau socioĂ©conomique familial mĂȘme si lâeffet du mode dâaccompagnement parental est relativement indĂ©pendant de celui-ci.Among the factors that influence studentsâ level of learning, the familyâs socio-economic status often receives attention from scientists and politicians. Many studies suggest that family characteristics have less of an impact on success in school than family process variables. More specifically, the emotional support of parents seems to be the most conclusive dimension with regard to protection factors for success at school. We wanted to find out: (1) what is the relationship between each of the methods of parental guidance assessed by the OECDâs Programme for International Student Assessment (PISA 2000) and the reading performance of Canadian children; (2) whether the relationship between each of these methods of parental guidance and academic success is more important than the familyâs socio-economic level and to what extent these relationships are connected. Cultural communication seems to be the most important method of parental support. Furthermore, the effect of cultural communication and social communication seems to be in part explained by the socio-economic level of the family, even if the effect of the method of parental guidance is relatively independent of this sort of communication
Traineesâ views of physician workforce policy in Quebec and their impact on career intentions
Background: The physician workforce in Quebec is regulated by a government-controlled plan. Many specialty trainees expressed concerns about securing a position. Our objective was to analyze physiciansâ employment issues in Quebec and their impact on residentsâ training in specialty programs.Methods: We distributed a web-based self-administrated survey to all Quebec residents training in specialty programs to capture data about residentsâ ability to find employment, career plans and perceptions regarding the workforce policy. Three groups were considered: graduates, non-graduating senior residents, and junior residents.Results: The overall response rate was 41.5% (985/2372). 47.3% of graduates did not have a position two months before finishing their training. Among residents without a position, 27.1% of graduates intend to leave Quebec, and 19.6% to complete a fellowship to postpone their start in practice. Overall, 77.9% of respondents believed there are not enough job opportunities for the number of trainees.Conclusion: Quebec specialty residents experience significant difficulties obtaining a position in the province and perceive that there are not enough job opportunities, which impacts their career plans and could drive them to complete a fellowship or plan to practice outside the province. Trainees' experience in finding employment needs to be considered in planning the physician workforce
Traineesâ views of physician workforce policy in Quebec and their impact on career intentions
Background: The physician workforce in Quebec is regulated by a government-controlled plan. Many specialty trainees expressed concerns about securing a position. Our objective was to analyze physiciansâ employment issues in Quebec and their impact on residentsâ training in specialty programs.Methods: We distributed a web-based self-administrated survey to all Quebec residents training in specialty programs to capture data about residentsâ ability to find employment, career plans and perceptions regarding the workforce policy. Three groups were considered: graduates, non-graduating senior residents, and junior residents.Results: The overall response rate was 41.5% (985/2372). 47.3% of graduates did not have a position two months before finishing their training. Among residents without a position, 27.1% of graduates intend to leave Quebec, and 19.6% to complete a fellowship to postpone their start in practice. Overall, 77.9% of respondents believed there are not enough job opportunities for the number of trainees.Conclusion: Quebec specialty residents experience significant difficulties obtaining a position in the province and perceive that there are not enough job opportunities, which impacts their career plans and could drive them to complete a fellowship or plan to practice outside the province. Trainees' experience in finding employment needs to be considered in planning the physician workforce
Divisibility of polynomials and degeneracy of integral points
We prove several statements about arithmetic hyperbolicity of certain blow-up
varieties. As a corollary we obtain multiple examples of simply connected
quasi-projective varieties that are pseudo-arithmetically hyperbolic. This
generalizes results of Corvaja and Zannier obtained in dimension 2 to arbitrary
dimension. The key input is an application of the Ru-Vojta's strategy. We also
obtain the analogue results for function fields and Nevanlinna theory with the
goal to apply them in a future paper in the context of Campana's conjectures.Comment: 26 pages. Comments welcom
Dosimetry and characterization of a 25âMeV proton beam line for preclinical radiobiology research
International audienc
Anatomic features underlying wood density, in 110 rainforest tree species from central Congo basin
Investigate the influence of fiber thickness and vessel diameter on the wood density in 110 rainforest tree species, and the relationships between wood density, wood water content and shrinking ratio.COBIMF
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