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IntroductionLa stigmatisation sociale liée au poids est corrélée à des résultats négatifs pour la santé. Les systèmes de soins de santé ne sont pas exempts de stigmatisation liée au poids, que ce soit des stéréotypes, des préjugés ou de la discrimination. Cette étude vise à examiner l’association entre la catégorie d’indice de masse corporelle (IMC) et le fait de subir ou non une discrimination dans un contexte de soins de santé. MéthodesNous avons utilisé les données de l’Enquête sur la santé dans les collectivités canadiennes de 2013, qui intègre pour la première fois à l’échelle nationale des mesures de la discrimination. Une analyse de régression logistique a été utilisée pour évaluer le risque de discrimination autodéclarée en matière de soins de santé chez les adultes (18 ans et plus) en fonction de différentes catégories de poids : non obèse (IMC inférieur à 30 kg/m²), obèse de classe I (IMC entre 30 et moins de 35 kg/m²) et obèse de classe II ou III (IMC de 35 kg/m² ou plus). RésultatsUn adulte sur 15 (6,4 %; intervalle de confiance [IC] à 95 % : 5,7 à 7,0 %) a déclaré avoir subi de la discrimination dans un établissement de soins de santé (cabinet de médecin, clinique, hôpital ou autre établissement). Par rapport aux personnes non obèses, le risque de discrimination dans des soins de santé était un peu plus élevé chez les personnes obèses de classe I (rapport de cotes [RC] = 1,20; IC à 95 % : 1,00 à 1,44) et significativement plus élevé parmi celles de classe II ou III (RC = 1,52; IC à 95 % : 1,21 à 1,91), après ajustement pour le sexe, l’âge et diverses caractéristiques socioéconomiques. ConclusionLes expériences quantifiées de discrimination liée au poids soulignent la nécessité de changer les attitudes et les pratiques des praticiens, ainsi que les politiques et les procédures des systèmes de soins de santé. Il est nécessaire d’approfondir la recherche sur les répercussions sociales et économiques de la stigmatisation liée au poids afin de guider des investissements ciblés visant à réduire la discrimination dans les systèmes de soins de santé, qui constituent des microcosmes de la société qu’ils reflètent.

IntroductionWeight-related social stigma is associated with adverse health outcomes. Health care systems are not exempt of weight stigma, which includes stereotyping, prejudice and discrimination. The objective of this study was to examine the association between body mass index (BMI) class and experiencing discrimination in health care. MethodsWe used data from the 2013 Canadian Community Health Survey, which included measurements of discrimination never collected previously on a national scale. Logistic regression analysis was used to assess the risk of self-reported discrimination in health care in adults (≥18 years) across weight categories: not obese (BMI $lt; 30 kg/m2), obese class I (BMI = 30–$lt; 35 kg/m2) and obese class II or III (BMI ≥ 35 kg/m2). ResultsOne in 15 (6.4%; 95% CI: 5.7–7.0%) of the adult population reported discrimination in a health care setting (e.g. physician’s office, clinic or hospital). Compared with those in the not obese group, the risk of discrimination in health care was somewhat higher among those in the class I obesity category (odds ratio [OR] = 1.20; 95% CI: 1.00–1.44) and significantly higher among those in class II/III (OR = 1.52; 95% CI: 1.21–1.91), after controlling for sex, age and other socioeconomic characteristics. ConclusionQuantified experiences of weight-related discrimination underscore the need to change practitioner attitudes and practices as well as the policies and procedures of the health care system. More research is needed on the social and economic impacts of weight stigma to inform focused investments for reducing discrimination in the health care system as a microcosm of the society it reflects.

This article discusses methods for selecting criteria used for stopping iterative regularization methods applied to solving continuation of gravity observed at or outside the Earth's surface down to the geoid. This computational step is required for determination of the gravimetric geoid by the Stokes approach. For surface gravity data measured with spatial resolutions at the kilometer level and higher, their downward continuation becomes ill posed and its solution numerically unstable. Two iterative methods often used for solving this problem, namely the Landweber and conjugate gradient least-squares (CGLS) methods, are investigated using a sample of surface gravity data synthesized from a global gravitational model over a mountainous test area in Colorado, USA. Five different commonly used stopping criteria are applied to both iterative methods and neither of them, except L-curve, succeed to stop the iterative process at the reasonable solution. A simple approach is proposed to stop the iterative methods exploiting stochastic properties of surface gravity data. Results of numerical tests suggest that a rather simple stopping criterion based on stochastics parameters of surface gravity data estimated using a leave-one-out cross-validation procedure yields results superior to those based on the L-curve approach which is best performing among the five standard methods for selecting the stopping criterion. Results based on the Landweber method outperform those based on the CGLS method. Iterative methods based on optimum numbers of iterations represent an alternative to commonly used regularization techniques for solving ill-posed inverse problems, such as Tikhonov, that require optimal estimates of regularization parameters. L'article examine les approches de sélection de critères utilisés pour arrêter les méthodes de régularisation itératives appliquées à la résolution du prolongement jusqu'au géoïde de la gravité observée à la surface de la Terre ou en dehors de celle-ci. Cette étape computationnelle est nécessaire pour la détermination du géoïde gravimétrique par l'approche de Stokes. Pour les données de gravité de surface mesurées à des résolutions spatiales kilométriques ou supérieures, leur prolongement vers le bas devient mal posé et sa solution, numériquement instable. Deux méthodes itératives souvent utilisées pour résoudre ce problème, les méthodes de Landweber et des moindres carrées du gradient conjugué (MCGC), sont examinées en utilisant un échantillon de données de gravité de surface synthétisées à partir d'un modèle gravitationnel planétaire sur une région montagneuse expérimentale au Colorado (États-Unis). Cinq critères d'arrêt couramment utilisés sont appliqués aux deux méthodes itératives et aucun d'entre eux, sauf la << L-curve >>, n'arrive à arrêter le processus itératif sur une solution raisonnable. Une approche simple est proposée pour arrêter les méthodes itératives, qui exploite les propriétés stochastiques des données de gravité de surface. Les résultats d'essais numériques portent à croire qu'un critère d'arrêt assez simple reposant sur des paramètres stochastiques des données de gravité de surface estimés en utilisant une procédure de validation croisée de type << leave-one-out >> donne de meilleurs résultats que les critères basés sur l'approche L-curve, la méthode qui, des cinq méthodes standards, performe le mieux pour lasélection de critères d'arrêt. Les résultats basés sur la méthodede Landweber sont meilleurs que ceux basés sur la méthode MCGC. Les méthodes itératives reposant sur des nombres optimaux d'itérations représentent une solutionderechange aux techniquesde régularisation couramment employées pour résoudre des problèmes inverses mal posés, comme celle de Tikhonov, qui requièrent des estimations optimales des paramètres de régularisation. [Traduit par la Rédaction], 1. Introduction Stokes's solution of the gravimetric geoid from surface gravity data requires gravity anomalies to be known on the geoid. Thus, surface gravity values observed at the topography must [...]

This study exploits administrative data for neuroepidemiological research and examines associations between neighbourhood environments and risk of hospitalization among multiple sclerosis (MS) patients in New Brunswick, Canada. We created a provincial database of MS patients by linking administrative health records with geographic-based characteristics of local communities. Using Cox models, we found the risk of admission for cardiometabolic complications was lower among residents of ethnically homogeneous neighbourhoods (hazards ratio [HR]: 0.75 [95% confidence interval (CI): 0.60–0.95]); that for mental health disorders was higher in socioeconomically deprived (HR: 1.80 [95% CI: 1.06–3.05]) and residentially unstable (HR: 1.61 [95% CI: 1.05–2.46]) neighbourhoods. Results suggest that selected neighbourhood environments may be associated with differential hospital burden among MS patients. [ABSTRACT FROM AUTHOR]

Introduction: Weight-related social stigma is associated with adverse health outcomes. Health care systems are not exempt of weight stigma, which includes stereotyping, prejudice and discrimination. The objective of this study was to examine the association between body mass index (BMI) class and experiencing discrimination in health care. Methods: We used data from the 2013 Canadian Community Health Survey, which included measurements of discrimination never collected previously on a national scale. Logistic regression analysis was used to assess the risk of self-reported discrimination in health care in adults (≥18 years) across weight categories: not obese (BMI < 30 kg/m²), obese class I (BMI = 30-<35 kg/m²) and obese class II or III (BMI ≥ 35 kg/m²). Results: One in 15 (6.4%; 95% CI: 5.7-7.0%) of the adult population reported discrimination in a health care setting (e.g. physician's office, clinic or hospital). Compared with those in the not obese group, the risk of discrimination in health care was somewhat higher among those in the class I obesity category (odds ratio [OR] = 1.20; 95% CI: 1.00-1.44) and significantly higher among those in class II/III (OR = 1.52; 95% CI: 1.21-1.91), after controlling for sex, age and other socioeconomic characteristics. Conclusion: Quantified experiences of weight-related discrimination underscore the need to change practitioner attitudes and practices as well as the policies and procedures of the health care system. More research is needed on the social and economic impacts of weight stigma to inform focused investments for reducing discrimination in the health care system as a microcosm of the society it reflects. [ABSTRACT FROM AUTHOR]

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In many European countries, normal heights referred to the quasi-geoid as introduced by Molodenskij in the mid-20th century are preferred to the classical height system that consists of orthometric heights and the geoid as a reference surface for these heights. The rationale for this choice is supposed to be that in the classical height system, neither the geoid, nor the orthometric height can be ever known with centimetre level accuracy because one would need to know the topographical mass density to a level that can never be achieved. The aim of this paper is to question the validity of this rationale. The common way of assessing the congruency of a local geoid model and the orthometric heights is to compare the geoid heights with the difference between orthometric heights provided by leveling and geodetic heights provided by GNSS. On the other hand, testing the congruency of a quasi-geoidal model with normal height a similar procedure is used, except that instead of orthometric heights, normal heights are employed. For the area of Auvergne, France, which is now a more or less standard choice for precise geoid or quasi-geoid testing, only the normal heights are supplied by the Institute Geographic National, the provider of the data. This is clearly the consequence of the European preference for the Molodenskij system. The quality of the height system is to be judged by the congruency of the difference of the geoid/quasi-geoid heights subtracted from the geodetic heights and orthometric/normal heights. To assess the congruency of the classical height system, the Helmert approximation of orthometric heights is typically used as the transformation between normal and Helmert's heights is easily done. However, the evaluation of the differences between Helmert's and the rigorous orthometric heights is somewhat more involved as will be seen from the review in this paper. For the area of interest, the differences between normal and Helmert's heights at the control leveling points range between -9.5 and 0 cm, differences between Helmert's and the rigorous orthometric heights vary between -3.6 and 1.1 cm. The local gravimetric geoid model of Auvergne, computed by the Stokes-Helmert technique, is used here to illustrate the accuracy of the classical height system. Results show a very reasonable standard deviation (STD) of 3.2 cm of the differences between geoid values, derived from control leveling points, and gravimetric geoid heights when Helmert's heights are employed and even a smaller STD of 2.9 cm when rigorous orthometric heights are used. A corresponding comparison of a quasi-geoid model, computed by Least-Squares Modification of Stokes method, with normal heights show an STD of 3.4 cm. [ABSTRACT FROM AUTHOR]

The aim of this paper is to show a present state-of-the-art precise gravimetric geoid determination using the UNB Stokes-Helmert's technique in a simple schematic way. A detailed description of a practical application of this technique in the Auvergne test area is also provided. In this paper, we discuss the most problematic parts of the solution: correct application of topographic and atmospheric effects including the lateral topographical density variations, downward continuation of gravity anomalies from the Earth surface to the geoid, and the optimal incorporation of the global gravity field into the final geoid model. The final model is tested on 75 GNSS/levelling points supplied with normal Molodenskij heights, which for this investigation are transformed to rigorous orthometric heights. The standard deviation of the computed geoid model is 3.3 cm without applying any artificial improvement which is the same as that of the most accurate quasigeoid. [ABSTRACT FROM AUTHOR]

In Molodensky's definition of the normal height, the mean normal gravity is computed explicitly. In definition of the orthometric height, however, the actual mean gravity along the plumbline within the topography could only be estimated approximately, because our knowledge about the actual topographic density distribution is still restricted. This practical limitation resulted in implementing various approximations to the orthometric height based on adopting a particular density hypothesis. Helmert's orthometric heights are the most commonly used for a vertical datum realization, because of their simple definition by assuming a planar topography of uniform density. To improve the accuracy, several different numerical models have been proposed by taking into consideration the terrain geometry, topographic density heterogeneities and implicitly also the mass density distributed below the geoid surface. Consequently, different formulae have been derived for conversion from the normal to orthometric heights (or vice versa), practically realized by computing the geoid-to-quasi-geoid separation (i.e. the difference between the geoid and the quasi-geoid). In this study, we review these methods and apply them at the regional study area of Himalaya and Tibet, characterized by the largest vertical displacement between the geoid and the quasi-geoid. We show that the maximum geoid-to-quasi-geoid separation reaches -4.06 m, when computed with a spectral resolution complete to the spherical harmonic degree of 2160. We further investigate the dependence of the geoid-to-quasi-geoid separation on the spectral resolution of used gravity and topographic models, showing that a higher degree harmonic spectrum (from 360 to 2160) modifies the geoid-to-quasi-geoid separation 2 m or even more, especially at the foothills of Himalaya. Our results also reveal that the topographic density variations within sediments and bedrock modify the geoid-to-quasi-geoid separation typically less than 5 per cent. This aspect is however still open for further analysis, because the upper continental crustal density models currently available have a low resolution and accuracy. We also discuss some aspects associated with the orthometric height definition, particularly addressing numerical schemes applied for computing the contribution of terrain geometry. We demonstrate that the mean spherical terrain correction has to be applied instead of a planar one (used in Mader, Niethammer, or Wirth's methods) for an accurate conversion between the normal and orthometric heights. [ABSTRACT FROM AUTHOR]

In context of the vertical datum unification, the geoid-to-quasi-geoid separation has been of significant interest in recent years, because most of existing local vertical datums are realized in the system of either normal or orthometric heights. Nevertheless, the normal-orthometric heights are still used in many other countries where the normal gravity values along leveling lines were adopted instead of the observed gravity. Whereas the conversion between the orthometric and normal heights is defined by means of the mean gravity disturbances (i.e. differences between the mean values of the actual and normal gravity) along the plumbline within the topography, differences between the normal and normal-orthometric heights can be described by means of the surface gravity disturbances. Since the normal gravity field does not reflect the topographic masses and actual mass density distribution inside the Earth, the definition of gravity represents a principal aspect for a realization of particular vertical datum. To address this issue in this study, we investigate effects of the Earth's inner density structure on the surface and mean gravity disturbances, and discuss their impact on the vertical datum realization. These two gravity field quantities are computed globally with a spectral resolution complete to a spherical harmonic degree 2160 using the global gravity, terrain, ice-thickness, inland bathymetry and crustal structure models. Our results reveal that both, the surface and mean gravity disturbances mostly comprise the gravitational signal of topography and masses distributed below the geoid surface. Moreover, in polar areas, a significant contribution comes from large glaciers. In contrast, the contributions of anomalous density distribution within the topography attributed to major lakes, sediments and bedrock density variations are much less pronounced. We also demonstrate that the mean gravity disturbances within the topography are significantly modified compared to the corresponding surface values mainly due to topographic elevation and terrain geometry as well as the presence of large glaciers in polar regions. Changes of the vertical gravity gradient within the topography attributed to the masses distributed below the geoid (dominated mainly by the isostatic signature and the long-wavelength gravitational signature of deep mantle density heterogeneities) are, on the other hand, relatively small. Despite differences between the normal and normal-orthometric heights could directly be assessed from the surface gravity disturbances only when taken along leveling lines with information about the spirit leveling height differences, our results indicate that differences between these two height systems can be significant. [ABSTRACT FROM AUTHOR]

Local gravity field modelling demands high-quality gravity data as well as an appropriate mathematical model. Particularly in coastal areas, there may be different types of gravity observations available, for instance, terrestrial, aerial, marine gravity, and satellite altimetry data. Thus, it is important to develop a proper tool to merge the different data types for local gravity field modelling and determination of the geoid. In this study, radial basis functions, as a commonly useful tool for gravity data integration, are employed to model the gravity potential field of the southern part of Iran using terrestrial gravity anomalies, gravity anomalies derived from re-tracked satellite altimetry, marine gravity anomalies, and gravity anomalies synthesized from an Earth gravity model. Reference GNSS/levelling (geometric) geoidal heights are used to evaluate the accuracy of the estimated local gravity field model. The gravimetric geoidal heights are in acceptable agreement with the geometric ones in terms of the standard deviation and the mean value which are 4.1 and 12 cm, respectively. Besides, the reference benchmark of the national first-order levelling network of Iran is located in the study area. The derived gravity model was used to compute the gravity potential difference at this point and then transformed into a height difference which results in the value of the shift of this benchmark with respect to the geoid. The estimated shift shows a good agreement with previously published studies. [ABSTRACT FROM AUTHOR]

Geometric heights, defined with respect to a geometric reference surface, are the most commonly used in planetary studies, but the use of physical heights defined with respect to an equipotential surface (typically the geoid) has been also acknowledged for specific studies (such as gravity-driven mass movements). In terrestrial studies, the geoid is defined as an equipotential surface that best fits the mean sea surface and extends under continents. Since gravimetric geoid modelling under continents is limited by the knowledge of a topographic density distribution, alternative concepts have been proposed. Molodensky introduced the quasigeoid as a height reference surface that could be determined from observed gravity without adopting any hypothesis about the topographic density. This concept is widely used in geodetic applications because differences between the geoid and the quasigeoid are mostly up to a few centimeters, except for mountainous regions. Here we discuss the possible applicability of Molodensky’s concept in planetary studies. The motivation behind this is rationalized by two factors. Firstly, knowledge of the crustal densities of planetary bodies is insufficient. Secondly, large parts of planetary surfaces have negative heights, implying that density information is not required. Taking into consideration the various theoretical and practical aspects discussed in this article, we believe that the choice between the geoid and the quasigeoid is not strictly limited because both options have advantages and disadvantages. We also demonstrate differences between the geoid and the quasigeoid on Mercury, Venus, Mars and Moon, showing that they are larger than on Earth. [ABSTRACT FROM AUTHOR]