5,465 research outputs found

    Putting the pieces of the puzzle together: Age and sex-specific estimates of migration amongst countries in the EU/EFTA, 2002-2007

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    Because of inconsistencies in reported flows and large amounts of missing data, our knowledge of international migration patterns in Europe is limited. Methods for overcoming data obstacles and harmonising international migration data, however, are improving. In this paper, we provide a methodology for integrating various pieces of incomplete information together, including a partial set of harmonised migration flows, to estimate a complete set of migration flows by origin, destination, age and sex for the 31 countries in the European Union and European Free Trade Association from 2002 to 2007. The results represent a synthetic data base that can be used to inform population projections, policy decisions and migration theory.Du fait d’incohĂ©rences dans l’enregistrement des flux migratoires et du grand nombre de donnĂ©es manquantes, notre connaissance des schĂ©mas de migrations internationales en Europe reste limitĂ©e. Cependant, les mĂ©thodes disponibles pour surmonter les obstacles liĂ©s aux donnĂ©es et pour harmoniser les donnĂ©es sur la migration internationale s’amĂ©liorent. Dans cet article, nous proposons une mĂ©thode pour combiner les diffĂ©rents Ă©lĂ©ments de ces informations incomplĂštes, incluant un ensemble partiel de donnĂ©es harmonisĂ©es sur les flux migratoires, afin d’estimer une sĂ©rie complĂšte de flux migratoires par pays d’origine, pays de destination, Ăąge et sexe pour les 31 pays de l’Union EuropĂ©enne et de l’Association EuropĂ©enne de Libre Echange de 2002 Ă  2007. Les rĂ©sultats constituent une base de donnĂ©es synthĂ©tique pouvant servir de base pour les projections de population, les dĂ©cisions politiques et les thĂ©ories relatives Ă  la migration

    Predicting pharmaceutical particle size distributions using kernel mean embedding

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    In the pharmaceutical industry, the transition to continuous manufacturing of solid dosage forms is adopted by more and more companies. For these continuous processes, high-quality process models are needed. In pharmaceutical wet granulation, a unit operation in the ConsiGmaTM-25 continuous powder-to-tablet system (GEA Pharma systems, Collette, Wommelgem, Belgium), the product under study presents itself as a collection of particles that differ in shape and size. The measurement of this collection results in a particle size distribution. However, the theoretical basis to describe the physical phenomena leading to changes in this particle size distribution is lacking. It is essential to understand how the particle size distribution changes as a function of the unit operation's process settings, as it has a profound effect on the behavior of the fluid bed dryer. Therefore, we suggest a data-driven modeling framework that links the machine settings of the wet granulation unit operation and the output distribution of granules. We do this without making any assumptions on the nature of the distributions under study. A simulation of the granule size distribution could act as a soft sensor when in-line measurements are challenging to perform. The method of this work is a two-step procedure: first, the measured distributions are transformed into a high-dimensional feature space, where the relation between the machine settings and the distributions can be learnt. Second, the inverse transformation is performed, allowing an interpretation of the results in the original measurement space. Further, a comparison is made with previous work, which employs a more mechanistic framework for describing the granules. A reliable prediction of the granule size is vital in the assurance of quality in the production line, and is needed in the assessment of upstream (feeding) and downstream (drying, milling, and tableting) issues. Now that a validated data-driven framework for predicting pharmaceutical particle size distributions is available, it can be applied in settings such as model-based experimental design and, due to its fast computation, there is potential in real-time model predictive control

    The Netherlands: Childbearing within the context of a "Poldermodel" society

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    The Netherlands has seen a considerable decline of the period total fertility rate and delayed childbearing, just like all other European countries. The drop in fertility, however, has not been as sharp as in many other regions of Europe. The period total fertility rate in the Netherlands has stabilized since the late 1970s at around 1.6 children per woman, and it has even risen slightly since 1995. In addition, although the Netherlands has one of the oldest first-time mothers, completed fertility is still rather high compared to other European countries, suggesting a strong ñ€Ɠcatching upñ€ of births by women in their thirties. This chapter provides a comprehensive overview of the main driving forces behind specific fertility trends in the Netherlands. Among other factors, it focuses on changing patterns of home leaving and union formation, declining partnership stability, and the growing acceptability and use of contraception. The chapter also looks at prolonged education, rising labor-force participation of women, economic uncertainties, the growing migrant population, and family policies. Data allowing, and to the extent possible, we examine the effects of these factors on decision-making about parenthood and the timing of childbearing.childbearing, Europe, fertility, Netherlands

    Impact of vacuum-induced surface freezing on inter- and intra-vial heterogeneity

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    This paper aims to study the impact of freezing on both within-batch (inter-vial) and within- product (intra-vial) heterogeneity. This analysis has been carried out using two freezing protocols, the conventional shelf-ramped method and the Vacuum Induced Surface Freezing, and placebo formulations containing both crystallizing (mannitol) and amorphous (lactose and sucrose) excipients. The freezing conditions (i.e., the temperature of freezing, the temperature and time of the equilibration phase, and the filling volume) were found to have a dramatic impact on both the within-batch and the within-product homogeneity. Overall, we observed that the control of freezing can effectively minimize the variability in product characteristics, and moisture content, within the same batch. In addition to more uniform production, the control of freezing was found to be fundamental to achieve a more uniform product than that produced by the shelf-ramped freezing method. The influence of the freezing protocol on the crystallization process of mannitol was also investigated, showing that the temperature of freezing plays a key role in the formation of the mannitol polymorphs

    Fine‐scale measurement of diffusivity in a microbial mat with nuclear magnetic resonance imaging

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    Noninvasive 1H‐nuclear magnetic resonance (NMR) imaging was used to investigate the diffusive properties of microbial mats in two dimensions. Pulsed field gradient NMR was used to acquire images of the H2O diffusion coefficient, Ds, and multiecho imaging NMR was used to obtain images of the water density in two structurally different microbial mats sampled from Solar Lake (Egypt). We found a pronounced lateral and vertical variability of both water density and water diffusion coefficient, correlated with the laminated and heterogeneous distribution of microbial cells and exopolymers within the mats. The average water density varied from 0.5 to 0.9, whereas the average water diffusion coefficient ranged from 0.4 to 0.9 relative to the values obtained in the stagnant water above the mat samples. The apparent water diffusivities estimated from NMR imaging compared well to apparent O2 diffusivities measured with a diffusivity microsensor. Analysis of measured O2 concentration profiles with a diffusion‐reaction model showed that both the magnitude of calculated rates and the depth distribution of calculated O2 consumption/production zones changed when the observed variations of diffusivity were taken into account. With NMR imaging, diffusivity can be determined at high spatial resolution, which can resolve inherent lateral and vertical heterogeneities found in most natural benthic systems

    Dramatic effect of fluid chemistry on cornstarch suspensions: linking particle interactions to macroscopic rheology

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    Suspensions of cornstarch in water exhibit strong dynamic shear-thickening. We show that partly replacing water by ethanol strongly alters the suspension rheology. We perform steady and non-steady rheology measurements combined with atomic force microscopy to investigate the role of fluid chemistry on the macroscopic rheology of the suspensions and its link with the interactions between cornstarch grains. Upon increasing the ethanol content, the suspension goes through a yield-stress fluid state and ultimately becomes a shear-thinning fluid. On the cornstarch grain scale, atomic force microscopy measurements reveal the presence of polymers on the cornstarch surface, which exhibit a co-solvency effect. At intermediate ethanol content, a maximum of polymer solubility induces high microscopic adhesion which we relate to the macroscopic yield stress
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