2,538 research outputs found
La politique de santĂ© publique et les aspects sociaux de la santĂ©Â : vers un management techno-scientifique de lâĂtat providence quĂ©bĂ©cois ?
Lâadoption au QuĂ©bec de la Loi sur la santĂ© publique de 2001 est souvent considĂ©rĂ©e comme une victoire de la santĂ© publique. Lâarticle 54 de cette loi accorde au ministre de la SantĂ© un droit de regard sur lâactivitĂ© des autres secteurs. Toutefois, lâoriginalitĂ© de la politique quĂ©bĂ©coise (consolidĂ©e rĂ©cemment) tient au fait quâelle se caractĂ©rise par un ensemble intĂ©grĂ© et Ă jour dâinstruments administratifs, programmatiques et lĂ©gislatifs. Ce dispositif, qui assure les fonctions essentielles de la santĂ© publique, reflĂšte aussi une prĂ©occupation pour les aspects sociaux de la santĂ©; de ce fait, il institutionnalise une vision technoscientifique des problĂšmes sociaux qui se rĂ©percute dans les autres politiques de lâĂtat providence quĂ©bĂ©cois. Lâauteur prĂ©sente les orientations rĂ©centes et explore la portĂ©e et les limites de la politique de santĂ© publique.The adoption of Quebecâs Public Health Act in 2001 is often seen as a victory for a public health perspective. Its Section 54 gives the Minister of Health the right to assess actions in other policy domains. The real originality, however, of Quebecâs policy (recently consolidated) is its integration and continuous up-dating of administrative, programmatic and legislative instruments. This legislation, intended to secure basic public health, also reflects a policy concern for the social dimensions of health, causing it to institutionalise a techno-scientific understanding of social problems, which then spills over onto other policies of the welfare state in Quebec. The article provides an overview of recent developments and explores the reach as well as the limits of public health policy
Design study for LANDSAT D attitude control system
A design and performance evaluation is presented for the LANDSAT D attitude control system (ACS). Control and configuration of the gimballed Ku-band antenna system for communication with the tracking and data relay satellite (TDRS). Control of the solar array drive considered part of the ACS is also addressed
Structural relationships among vegetation, soil fauna and humus form in a subalpine forest ecosystem: a Hierarchical Multiple Factor Analysis (HMFA)
International audienceAboveground vegetation, four belowground fauna groups and humus composition have been analyzed in order to investigate the links between autotrophic and heterotrophic communities in a Norway-spruce mountain forest in Tours-en-Savoie (France). The aboveground plant community was recorded in small patches corresponding to contrasting microhabitats. Animal communities and humus layers were sampled within the same patches. The relationships between humus profile, faunistic and floristic compositional gradients were investigated by Multiple Factor Analysis (MFA) and, for the first time in ecology, a Hierarchical Multiple Factor Analysis (HMFA) was used to interpret differences among humus layers. The analysis revealed a pattern with three main groups of microhabitats. The thorough study of separate humus layers could explain this result. The interplay of plant-animal-soil interactions is likely to drive the ecosystem toward three alternative states supporting humus traditional classification between mull-mor-moder. HMFA revealed the importance of depth to explain this contrast among humus forms, using humus layers as diagnostic tools in both inert and living components. HMFA also showed contrast between unexploited and exploited parts of the forest, but the study of soil and vegetation indicate that this contrast does not only hold in forest management but also in geomorphology. RV-coefficients among the six groups of variables showed significant fauna-fauna relationships in almost all humus layers except Actinedida. Plant-soil interactions are not as strong as expected and are even weaker when the soil in question is deep. In addition, HMFA failed to show direct interactions between plant and soil fauna but, paradoxically, HMFA does suggest that indirect plant-fauna interactions are at the focus of the ecosystem strategy that leads to the differentiation of ecological niches within the forest mosaic
Quantum order by disorder in frustrated diamond lattice antiferromagnets
We present a quantum theory of frustrated diamond lattice antiferromagnets.
Considering quantum fluctuations as the predominant mechanism relieving spin
frustration, we find a rich phase diagram comprising of six phases with
coplanar spiral ordering in addition to the N\'eel phase. By computing the
specific heat of these ordered phases, we obtain a remarkable agreement between
-spiral ordering and the experimental specific heat data for the
diamond lattice spinel compounds MnScS, CoO and CoRhO,
i.e. specific heat data is a strong evidence for -spiral ordering in
all of these materials. This prediction can be tested in future neutron
scattering experiments on CoO and CoRhO, and is consistent with
existing neutron scattering data on MnScS. Based on this agreement we
infer a monotonically increasing relationship between frustration and the
strength of quantum fluctuations.Comment: 4 pages, 2 figures, version published in PR
Expanded retina territory by midbrain transformation upon overexpression of Six6 (Optx2) in Xenopus embryos.
Une méthodologie générale de comparaison de modÚles d'estimation régionale de crue
L'estimation du dĂ©bit QT de pĂ©riode de retour T en un site est gĂ©nĂ©ralement effectuĂ©e par ajustement d'une distribution statistique aux donnĂ©es de dĂ©bit maximum annuel de ce site. Cependant, l'estimation en un site oĂč l'on dispose de peu ou d'aucune donnĂ©es hydrologiques doit ĂȘtre effectuĂ©e par des mĂ©thodes rĂ©gionales qui consistent Ă utiliser l'information existante en des sites hydrologiquement semblables au site cible. Cette procĂ©dure est effectuĂ©e en deux Ă©tapes: (a) dĂ©termination des sites hydrologiquemcnt semblables(b) estimation rĂ©gionalePour un dĂ©coupage donnĂ© (Ă©tape a), nous proposons trois approches mĂ©thodologiques pour comparer les diffĂ©rentes mĂ©thodes d'estimation rĂ©gionale. Ces approches sont dĂ©crites en dĂ©tail dans ce travail. Plus particuliĂšrement il s'agit de- simulation par la mĂ©thode du bootstrap - analyse de rĂ©gression ou Bayes empirique - mĂ©thode bayĂ©sienne hiĂ©rarchiqueEstimation of design flows with a given return period is a common problem in hydrologic practice. At sites where data have been recorded during a number of years, such an estimation can be accomplished by fitting a statistical distribution to the series of annual maximum floods and then computing the (1-1/T) -quantile in the estimated distribution. However, frequently there are no, or only few, data available at the site of interest, and flood estimation must then be based on regional information. In general, regional flood frequency analysis involves two major steps:- determination of a set of gauging stations that are assumed to contain information pertinent to the site of interest. This is referred to as delineation of homogeneous regions.- estimation of the design flood at the target site based on information from the sites ofthe homogeneous region.The merits of regional flood frequency analysis, at ungauged sites as well as at sites where some local information is available, are increasingly being acknowledged, and many research papers have addressed the issue. New methods for delitneating regions and for estimating floods based on regional information have been proposed in the last decade, but scientists tend to focus on the development of new techniques rather than on testing existing ones. The aim ofthis paper is to suggest methodologies for comparing different regional estimation alternatives.The concept of homogeneous regions has been employed for a long time in hydrology, but a rigorous detinition of it has never been given. Usually, the homogeneity concerns dimensionless statistical characteristics of hydrological variables such as the coefficient of variation (Cv) and the coefficient of skewness (Cs) of annual flood series. A homogeneous region can then be thought of as a collection of stations with flood series whose statistical properties, except forscale, are not significantly different from the regional mean values. Tests based on L-moments are at present much applied for validating the homogeneity of a given region. Early approaches to regional flood frequency analysis were based on geographical regions, but recent tendencies are to deline homogeneous regions from the similarity of basins in the space of catchment characteristics which are related to hydrologic characteristics. Cluster analysis can be used to group similar sites, but has the disadvantage that a site in the vicinity ofthe cluster border may be closer to sites in other clusters than to those ofits ovm group. Burn (1990a, b) has recently suggested a method where each site has its owm homogeneous region (or region of influence) in which it is located at the centre of gravity.Once a homogeneous region has been delineated, a regional estimation method must be selected. The index flood method, proposed by Dalrymple (1960), and the direct regression method are among the most commonly used procedures. Cunnane (1988) provides an overview of several other methods. The general performance of a regional estimation method depends on the amount of regional information (hydrological as well as physiographical and climatic), and the size and homogeneity of the region considered relevant to the target site. Being strongly data-dependent, comparisons of regional models will be valid on a local scale only. Hence, one cannot expect to reach a general conclusion regarding the relative performance of different models, although some insight may be gained from case studies.Here, we present methodologies for comparing regional flood frequency procedures (combination of homogeneous regions and estimation methods) for ungauged sites. Hydrological, physiographical and climatic data are assumed to be available at a large number of sites, because a comparison of regional models must be based on real data. The premises of these methodologies are that at each gauged site in the collection of stations considered, one can obtain an unbiased atsite estimate of a given flood quantile, and that the variance of this estimate is known. Regional estimators, obtained by ignoring the hydrological data at the target site, are then compared to the at-site estimate. Three difrerent methodologies are considered in this study:A) Bootstrap simulation of hydrologic dataIn order to preserve spatial correlation of hydrologic data (which may have an important impact on regional flood frequency procedures), we suggest performing bootstrap simulation of vectors rather than scalar values. Each vector corresponds to a year for which data are available at one or more sites in the considered selection of stations; the elements ofthe vectors are the different sites. For a given generated data scenario, an at-site estimate and a regional estimate at each site considered can be calculated. As a performance index for a given regional model, one can use, for example, the average (over sites and bootstrap scenarios) relative deviation ofthe regional estimator from the at-site estimator.B) Regression analysisThe key idea in this methodology is to perform a regression analysis with a regional estimator as an explanatory variable and the unknown quantile, estimated by the at-site method, as the dependent variable. It is reasonable to assume a linear relation between the true quantiles and the regional estimators. The estimated regression coeflicients express the systematic error, or bias, of a given regional procedure, and the model error, estimated for instance by the method of moments, is a measure of its variance. It is preferable that the bias and the variance be as small as possible, suggesting that these quantities be used to order different regional procedures.C) Hierarchical Bayes analysisThe regression method employed in (B) can also be regarded as the resultfrom an empirical Bayes analysis in which point estimates of regression coeflicients and model error are obtained. For several reasons, it may be advantageous to proceed with a complete Bayesian analysis in which bias and model error are considered as uncertain quantities, described by a non-informative prior distribution. Combination of the prior distribution and the likelihood function yields through Bayes, theorem the posterior distribution of bias and model error. In order to compare different regional models, one can then calculate for example the mean or the mode of this distribution and use these values as perfonnance indices, or one can compute the posterior loss
Design study for LANDSAT-D attitude control system
The gimballed Ku-band antenna system for communication with TDRS was studied. By means of an error analysis it was demonstrated that the antenna cannot be open loop pointed to TDRS by an onboard programmer, but that an autotrack system was required. After some tradeoffs, a two-axis, azimuth-elevation type gimbal configuration was recommended for the antenna. It is shown that gimbal lock only occurs when LANDSAT-D is over water where a temporary loss of the communication link to TDRS is of no consequence. A preliminary gimbal control system design is also presented. A digital computer program was written that computes antenna gimbal angle profiles, assesses percent antenna beam interference with the solar array, and determines whether the spacecraft is over land or water, a lighted earth or a dark earth, and whether the spacecraft is in eclipse
The Crystal Structure and Molecular Conformation of 3,7-Dichlorophenoselenazine
The crystal structure of SeC12NCI2H7 has been solved by Patterson and Fourier methods and refined to
an R of 7-5 % by full-matrix least-squares methods. The unit cell is orthorhombic, with a-- 7-995 (3),
b = 23.808 (1), c = 6.028 (2)/~, and four molecules in the cell. The space group is Pnma. The structure
contains layers of molecules centred on the mirror planes at b/4 and 3b/4
The Structure of l-Phenyl-4,5-(l,2-D-glucofurano)imidazolidin-2-one
The crystal structure of Cl3Ht6N20 5 has been solved
by direct methods. Crystal data are a -- 9.033 (1), b --
10.097 (1), c -- 7.155 (1)A, fl= 105.92 (1) °, Z -- 2,
space group P21 (from statistics). The final R value for
1246 independent reflexions was 0.068. The glucofurano-
imidazolidine group adopts a cis form of
coupling with a dihedral angle of 70.2 (6) °. The phenyl substituent forms a dihedral angle of 15.1 (6) ° with the
imidazolidine ring plane. Intermolecular hydrogen
bonds link molecules related by a screw axis to give
helical chains parallel to b
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