What should an index of school segregation measure?

The article aims to make a methodological contribution to the education segregation literature, providing a critique of previous measures of segregation used in the literature, as well as suggesting an alternative approach to measuring segregation. Specifically, the paper examines Gorard, Fitz and Taylor's finding that social segregation between schools, as measured by free school meals (FSM) entitlement, fell significantly in the years following the 1988 Education Reform Act. Using Annual Schools Census data from 1989 to 2004, the paper challenges the magnitude of their findings, suggesting that the method used by Gorard et al. seriously overstates the size of the fall in segregation. We make the case for a segregation curve approach to measuring segregation, where comparisons of the level of segregation are possible regardless of the percentage FSM eligibility. Using this approach, we develop a new method for describing both the level and the location of school segregation

Higher education, career opportunities, and intergenerational inequality

The UK government has expressed a desire to increase social mobility, with policies to help achieve this aim focused on reducing inequalities in educational attainment. This paper draws together established and new information about the contribution that higher education can make to social mobility using a life-course approach, considering differences by family background in terms of university attendance and achievement, as well as occupation and earnings following graduation. We find substantial socio-economic differences at each stage. Young people from poorer backgrounds are, on average, less likely to go to university than their richer peers. Even among the selected group who do go to university, they are less likely to attend the highest status institutions, less likely to graduate, and less likely to achieve the highest degree classes. These differences in degree outcomes contribute to the lower average earnings of graduates from poorer families, but earnings differentials go well beyond those driven purely by degree attainment or institution attended. The evidence strongly suggests that, even after taking these factors into account, graduates from affluent families are more likely to obtain a professional job and to see higher earnings growth in the labour market. We discuss the implications of these findings for the prospects of higher education as a route to greater social mobility

Paramphistomum daubneyi : caractéristiques de l’infestation chez trois espèces de limnées

Experimental infections of two South American lymnaeids (Lymnaea neotropica and L. viatrix var. ventricosa) with Paramphistomum daubneyi were carried out to determine if these snail species could sustain larval development of this digenean and, if so, to specify their potential for cercarial production. A French population of Galba truncatula infected and raised according to the same protocol served as controls. In both experiments, prevalence of P. daubneyi infections in snails did not significantly differ from each other. In snail groups evaluated for cercarial shedding (first experiment), a significantly lower number of shed cercariae was noted for L. neotropica, while those from G. truncatula and L. v. ventricosa did not differ significantly from each other. Dissection of infected snails at day 65 post-exposure at 20°C (second experiment) found significantly lower burdens of P. daubneyi rediae and cercariae in the bodies of L. neotropica than in those of G. truncatula and L. v. ventricosa. Compared to total cercarial production observed in dissected snails, the percentage of cercariae which exited from snails was 75.6% for G. truncatula, 21.6% for L. neotropica, and 91.4% for L. v. ventricosa. This last species seems to be a good candidate for metacercarial production of P. daubneyi.Des infestations expérimentales de deux limnées sud-américaines (Lymnaea neotropica et L. viatrix var. ventricosa) avec Paramphistomum daubneyi ont été réalisées pour déterminer si ces espèces peuvent assurer le développement larvaire de ce Digène et, dans l’affirmative, pour préciser leur potentiel dans la production cercarienne. Les témoins sont constitués par une population française de Galba truncatula infestée et élevée selon le même protocole. Dans les deux expériences, les prévalences de l’infestation par P. daubneyi chez les mollusques sont proches les unes des autres. Chez les groupes suivis pour les émissions cercariennes (première expérience), le nombre de cercaires émises est significativement plus faible chez L. neotropica, tandis que les chiffres notés chez G. truncatula et L. v. ventricosa ne présentent pas de différence significative. Si les mollusques infestés sont disséqués au 65ème jour post-exposition à 20 °C (seconde expérience), les charges rédienne et cercarienne trouvées dans le corps des L. neotropica sont significativement plus faibles que celles notées chez G. truncatula et L. v. ventricosa. Par rapport à la production cercarienne totale chez les mollusques disséqués, le pourcentage de cercaires qui sont émises est de 75,6 % chez G. truncatula, 21,6 % chez L. neotropica et de 91,4 % chez L. v. ventricosa. Cette dernière espèce semble être un bon candidat pour la production métacercarienne de P. daubneyi.Centro de Diagnóstico e Investigaciones Veterinaria

Paramphistomum daubneyi : caractéristiques de l’infestation chez trois espèces de limnées

Experimental infections of two South American lymnaeids (Lymnaea neotropica and L. viatrix var. ventricosa) with Paramphistomum daubneyi were carried out to determine if these snail species could sustain larval development of this digenean and, if so, to specify their potential for cercarial production. A French population of Galba truncatula infected and raised according to the same protocol served as controls. In both experiments, prevalence of P. daubneyi infections in snails did not significantly differ from each other. In snail groups evaluated for cercarial shedding (first experiment), a significantly lower number of shed cercariae was noted for L. neotropica, while those from G. truncatula and L. v. ventricosa did not differ significantly from each other. Dissection of infected snails at day 65 post-exposure at 20°C (second experiment) found significantly lower burdens of P. daubneyi rediae and cercariae in the bodies of L. neotropica than in those of G. truncatula and L. v. ventricosa. Compared to total cercarial production observed in dissected snails, the percentage of cercariae which exited from snails was 75.6% for G. truncatula, 21.6% for L. neotropica, and 91.4% for L. v. ventricosa. This last species seems to be a good candidate for metacercarial production of P. daubneyi.Des infestations expérimentales de deux limnées sud-américaines (Lymnaea neotropica et L. viatrix var. ventricosa) avec Paramphistomum daubneyi ont été réalisées pour déterminer si ces espèces peuvent assurer le développement larvaire de ce Digène et, dans l’affirmative, pour préciser leur potentiel dans la production cercarienne. Les témoins sont constitués par une population française de Galba truncatula infestée et élevée selon le même protocole. Dans les deux expériences, les prévalences de l’infestation par P. daubneyi chez les mollusques sont proches les unes des autres. Chez les groupes suivis pour les émissions cercariennes (première expérience), le nombre de cercaires émises est significativement plus faible chez L. neotropica, tandis que les chiffres notés chez G. truncatula et L. v. ventricosa ne présentent pas de différence significative. Si les mollusques infestés sont disséqués au 65ème jour post-exposition à 20 °C (seconde expérience), les charges rédienne et cercarienne trouvées dans le corps des L. neotropica sont significativement plus faibles que celles notées chez G. truncatula et L. v. ventricosa. Par rapport à la production cercarienne totale chez les mollusques disséqués, le pourcentage de cercaires qui sont émises est de 75,6 % chez G. truncatula, 21,6 % chez L. neotropica et de 91,4 % chez L. v. ventricosa. Cette dernière espèce semble être un bon candidat pour la production métacercarienne de P. daubneyi.Centro de Diagnóstico e Investigaciones Veterinaria

Kinetic and gas-phase study of the chemical vapor deposition of silicon carbide from C2H3SiCl3/H2

The chemical vapor deposition (CVD) of silicon carbide from vinyltrichlorosilane (VTS) was studied to identify a range of conditions leading to pure crystalline SiC. The deposition rate was recorded to evidence the various deposition regimes. Gas phase, elemental analyses and infiltration tests were also performed. Three distinct chemical reaction regimes were identified. In CVD conditions, carbon is co-deposited at low temperature while VTS is only partially decomposed. In infiltration conditions, the composition switches to pure SiC inside the porous substrate because of a depletion of reactive hydrocarbon species. Competing heterogeneous reactions are responsible for a hysteresis versus temperature, in both deposition rate and composition of the deposit. The high temperature domain is the most suitable to deposit pure crystalline SiC in CVD conditions. Hydrogen dilution strongly accelerates the homogeneous decomposition of VTS as compared to argon. Assumptions on the reaction mechanism were proposed describing the chemistry of this precursor

Evaluation of SiC-particle connectivity in functionally graded Al/SiCp composites by synchrotron radiation holographic microtomography

Reliability of functionally graded metal matrix composites (FGMMCs) for automotive components is still dependent on the detailed knowledge of the mechanisms of the microstructural build-up, for instance on the mechanisms leading to the distribution and relative positions of the reinforcing particles. In order to assess the influence of the SiC particle size on the 3-D inter-particle connectivity in functionally graded Al/SiCp composites produced by centrifugal casting, X-ray microtomography experiments were performed at the ID19 beamline in ESRF (European Synchrotron Radiation Facility). The FGMMCs consisted of an Al-10Si-2Mg alloy matrix, reinforced by an average SiC particle volume fraction of 0.10; two different average sizes were used: 37 μm and 12 μm. The holographic modification of the X-ray CMT (Computer Micro- Tomography) method allowed to obtain neatly contrasted images, as opposed to classical CMT.Good agreement was found between the particle size evaluated by CMT and by laser interferometry. Particle clustering has been evaluated in number and volume, showing that a lower mean particle size is related to more clustering. Such an adverse effect relies on the importance of particle/liquid alloy surface tension. Also, the mean particle size has been evaluated as a function of particle number within a cluster: as expected, the larger a cluster, the larger the particles inside it.(undefined

In search of a pan-European culture: European values, beliefs and models of selfhood in global perspective

What, if any, are the common cultural characteristics that distinguish European societies and groups when viewed against a backdrop of global cultural variation? We sought to identify any shared features of European cultures through secondary multilevel analyses of two large datasets that together provided measures of cultural values, beliefs and models of selfhood from samples in all inhabited continents. Although heterogeneous in many respects—including the value dimension of autonomy versus embeddedness—European samples shared two distinctive features: a decontextualized representation of personhood and a cultural model of selfhood emphasizing difference from others. Compared to samples from other regions, European samples on average also emphasized egalitarianism and harmony values, commitment to others in their models of selfhood, and an immutable concept of personhood, but not uniformly so. We interpret these findings in relation to a Durkheimian model of individualism

Economics of education research: a review and future prospects

In this paper we offer an appraisal of the economics of education research area, charting its history as a field and discussing the ways in which economists have contributed both to education research and to education policy-making. In particular, we highlight the theoretical and methodological contributions that economists have made to the field of education during the last 50 years. Despite the success of the economics of education as a field of inquiry, we argue that some of the contributions made by economists could be limited if the economics of education is seen as quite distinct from the other disciplines working in the field of education. In these areas of common interest, economists need to work side by side with the other major disciplines in the field of education if their contribution to the field is to be maximised, particularly in terms of applying improved methodology. We conclude that the study of education acquisition and its economic and social impact in the economics of education research area is very likely to remain a fertile research ground. Acknowledgement

Individualization as driving force of clustering phenomena in humans

One of the most intriguing dynamics in biological systems is the emergence of clustering, the self-organization into separated agglomerations of individuals. Several theories have been developed to explain clustering in, for instance, multi-cellular organisms, ant colonies, bee hives, flocks of birds, schools of fish, and animal herds. A persistent puzzle, however, is clustering of opinions in human populations. The puzzle is particularly pressing if opinions vary continuously, such as the degree to which citizens are in favor of or against a vaccination program. Existing opinion formation models suggest that "monoculture" is unavoidable in the long run, unless subsets of the population are perfectly separated from each other. Yet, social diversity is a robust empirical phenomenon, although perfect separation is hardly possible in an increasingly connected world. Considering randomness did not overcome the theoretical shortcomings so far. Small perturbations of individual opinions trigger social influence cascades that inevitably lead to monoculture, while larger noise disrupts opinion clusters and results in rampant individualism without any social structure. Our solution of the puzzle builds on recent empirical research, combining the integrative tendencies of social influence with the disintegrative effects of individualization. A key element of the new computational model is an adaptive kind of noise. We conduct simulation experiments to demonstrate that with this kind of noise, a third phase besides individualism and monoculture becomes possible, characterized by the formation of metastable clusters with diversity between and consensus within clusters. When clusters are small, individualization tendencies are too weak to prohibit a fusion of clusters. When clusters grow too large, however, individualization increases in strength, which promotes their splitting.Comment: 12 pages, 4 figure