Body size, activity, employment and wages in Europe: A first approach

This paper examines the associations between obesity, employment status and wages for several European countries. Our results provide weak evidence that obese workers are more likely to be unemployed or tend to be more segregated in self-employment jobs than their non-obese counterparts. We also find difficult to detect statistically significant relationships between obesity and wages. As previously reported in the literature, the association between obesity, unemployment and wages seems to be different for men and women. Moreover, heterogeneity is also found across countries. Such heterogeneity can be somewhat explained by some labor market institutions, such as the collective bargaining coverage and the employer-provided health insurance.

Openness, government size and the terms of trade

This paper investigates the relationship between trade openness and the size of government, both theoretically and empirically. We show that openness can increase the size of governments through two channels: (1) a terms of trade externality, whereby trade lowers the domestic cost of taxation and (2) the demand for insurance, whereby trade raises risk and public transfers. We provide a unified framework for studying and testing these two mechanisms. First, we show how their relative strength depends on a key parameter, the elasticity of substitution between domestic and foreign goods. Second, while the terms of trade externality leads to inefficiently large governments, the increase in public spending due to the demand for insurance is optimal. We show that large volumes of trade may result in welfare losses if the terms of trade externality is strong enough while small volumes of trade are always beneficial. Third, we provide new evidence on the positive association between openness and the size of government and test whether it is consistent with the terms of trade externality or the demand for insurance. Our findings suggest that the positive relationship is remarkably robust and that the terms of trade externality may be the driving force behind it, thus raising warnings that globalization may have led to inefficiently large governments.

How different are returns to education? Evidence from German school choices

This study presents estimates of returns to post-secondary educationand wage differentials among graduates fromdifferent secondary schoolsin Germany. I use an empirical model that captures the basic features ofthe German education system. It controls for selection into post-secondaryeducation and treats latter as endogenous in the wage equation. Myresults show that OLS estimates are severely biased. The direction ofthe bias depends on the secondary school type. Annual returns topost-secondary education differ significantly: they are eight timeshigher for graduates from the highest secondary school than for graduatesfrom the lowest secondary school.

A finite-population revenue management model and a risk-ratio procedure for the joint estimation of population size and parameters

Many dynamic revenue management models divide the sale period into a finite number of periods T and assume, invoking a fine-enough grid of time, that each period sees at most one booking request. These Poisson-type assumptions restrict the variability of the demand in the model, but researchers and practitioners were willing to overlook this for the benefit of tractability of the models. In this paper, we criticize this model from another angle. Estimating the discrete finite-period model poses problems of indeterminacy and non-robustness: Arbitrarily fixing T leads to arbitrary control values and on the other hand estimating T from data adds an additional layer of indeterminacy. To counter this, we first propose an alternate finite-population model that avoids this problem of fixing T and allows a wider range of demand distributions, while retaining the useful marginal-value properties of the finite-period model. The finite-population model still requires jointly estimating market size and the parameters of the customer purchase model without observing no-purchases. Estimation of market-size when no-purchases are unobservable has rarely been attempted in the marketing or revenue management literature. Indeed, we point out that it is akin to the classical statistical problem of estimating the parameters of a binomial distribution with unknown population size and success probability, and hence likely to be challenging. However, when the purchase probabilities are given by a functional form such as a multinomial-logit model, we propose an estimation heuristic that exploits the specification of the functional form, the variety of the offer sets in a typical RM setting, and qualitative knowledge of arrival rates. Finally we perform simulations to show that the estimator is very promising in obtaining unbiased estimates of population size and the model parameters.

The size and distribution of donations: Effects of numbers of potential recipients

Whereas much literature exists on choice overload, little is known about effects of numbers of alternatives in donation decisions. How do these affect both the size and distribution of donations? We hypothesize that donations are affected by the reputation of recipients and increase with their number, albeit at a decreasing rate. Allocations to recipients reflect different concepts of fairness equity and equality. Both may be employed but, since they differ in cognitive and emotional costs, numbers of recipients are important. Using a cognitive (emotional) argument, distributions become more uniform (skewed) as numbers increase. In a survey, respondents indicated how they would donate lottery winnings of 50 Euros. Results indicated that more was donated to NGO s that respondents knew better. Second, total donations increased with the number of recipients albeit at a decreasing rate. Third, distributions of donations became more skewed as numbers increased. We comment on theoretical and practical implications.

Systematic study of the static electrical properties of the CO molecule: influence of the basis set size and correlation energy

The influence of the basis set size and the correlation energy in the static electrical properties of the CO molecule is assessed. In particular, we have studied both the nuclear relaxation and the vibrational contributions to the static molecular electrical properties, the vibrational Stark effect (VSE) and the vibrational intensity effect (VIE). From a mathematical point of view, when a static and uniform electric field is applied to a molecule, the energy of this system can be expressed in terms of a double power series with respect to the bond length and to the field strength. From the power series expansion of the potential energy, field-dependent expressions for the equilibrium geometry, for the potential energy and for the force constant are obtained. The nuclear relaxation and vibrational contributions to the molecular electrical properties are analyzed in terms of the derivatives of the electronic molecular properties. In general, the results presented show that accurate inclusion of the correlation energy and large basis sets are needed to calculate the molecular electrical properties and their derivatives with respect to either nuclear displacements or/and field strength. With respect to experimental data, the calculated power series coefficients are overestimated by the SCF, CISD, and QCISD methods. On the contrary, perturbation methods (MP2 and MP4) tend to underestimate them. In average and using the 6-311 + G(3df) basis set and for the CO molecule, the nuclear relaxation and the vibrational contributions to the molecular electrical properties amount to 11.7%, 3.3%, and 69.7% of the purely electronic μ, α, and β values, respectively

Characterization and Application of Educational Virtual Environments for Science Teaching in Secondary School

This work describes the characteristics of a representative set of seven different virtual laboratories (VLs) aimed for science teaching in secondary school. For this purpose, a 27-item evaluation model that facilitates the characterization of the VLs was prepared. The model takes into account the gaming features, the overall usability, and also the potential to induce scientific literacy. Five of the seven VLs were then tested with two larger and highly heterogenic groups of students, and in two different contexts – biotechnology and physics, respectively. It is described how the VLs were received by the students, taking into account both their motivation and their self-reported learning outcome. In some cases, students’ approach to work with the VLs was recorded digitally, and analyzed qualitatively. In general, the students enjoyed the VL activities, and claimed that they learned from them. Yet, more investigation is required to address the effectiveness of these tools for significant learning.

Efectos de la presencia social de las lenguas escolares en el desarrollo lingüístico del alumnado extranjero. Un estudio empírico en Cataluña = The Social Presence of School Languages and Their Effects on the Development of Immigrant Students’ Linguistic Proficiency. An Empirical Study in Catalonia

El estudio de las variables relacionadas con la adquisición de las lenguas escolares en contextos bilingües y multilingües ha resurgido a raíz de la incorporación de alumnado extranjero al sistema educativo español. En este sentido, y gracias a su peculiar situación sociolingüística, Cataluña se ha convertido en un observatorio perfecto para estudiar el proceso de adquisición de lenguas del alumnado extranjero. En este artículo presentamos una parte de los datos obtenidos en la evaluación del conocimiento de catalán y del castellano de 668 alumnos extranjeros de sexto de Primaria escolarizados en 57 centros de Cataluña. Con ello pretendemos estudiar los efectos de la presencia y del uso social de las lenguas escolares en el conocimiento lingüístico de este alumnado. La hipótesis principal es que el desarrollo de buenos niveles de conocimiento escrito de las lenguas escolares por parte de los alumnos extranjeros depende, en buena medida, de las oportunidades que haya en el entorno social para que ellos puedan utilizar estas lenguas en los intercambios comunicativos informales con sus compañeros o con otros adultos. Las conclusiones del trabajo señalan las relaciones existentes entre el desarrollo de habilidades lingüísticas conversacionales y el de habilidades lingüísticas cognitivo-académicas (Cummins, 1979b), en el sentido de que tanto el conocimiento escrito de catalán como el de castellano que tiene el alumnado extranjero están condicionados por el nivel de desarrollo conversacional previo en ambas lenguas. Además, apuntan a que la transferencia de habilidades lingüísticas cognitivo-académicas no se produce directamente entre el catalán y el castellano, sino que depende fundamentalmente de la presencia social que tengan estas lenguas y de sus usos informales. Así, en la medida en que un buen número de estudiantes extranjeros no desarrolla suficiente competencia lingüística conversacional ni en catalán ni en castellano, el proceso de adquisición de las lenguas escolares se alarga más allá de los seis años

Identidad nacional, lengua y escuela = National identity, language and school

La globalización cuestiona la existencia de una relación mimética entre ciudadanía y Estado-nación. Las identidades homogéneas, sustentadas ideológicamente en nociones como «lengua nacional», plantean problemas en sociedades en las que ha crecido espectacularmente la diversidad lingüística e identitaria. Cataluña es un territorio en el que una parte de la población afirma una identidad catalana distinta a la española y viceversa. Además, se ha teorizado que la identidad catalana y la lengua catalana coexisten mutuamente. Por eso, se suceden voces que defienden la presencia del catalán en la educación escolar como fuente de la identidad nacional catalana, mientras que otras voces defienden su presencia simplemente como una buena manera de aprender el catalán cuando no se puede aprender en el medio social y familiar. En los últimos años, Cataluña ha recibido casi un millón de personas extranjeras que han modificado notablemente su situación sociolingüística. Las últimas encuestas manifiestan que un 6,3% de la población utiliza habitualmente una lengua distinta del catalán y del castellano. En este marco, mostramos las construcciones identitarias de un grupo de adolescentes de origen extranjero que están en el segundo ciclo de la ESO. Los datos fueron recogidos mediante dos grupos de discusión de seis-siete estudiantes de distinto origen, lengua propia y tiempo de residencia en Cataluña. Los resultados muestran la importancia del lugar de origen en la construcción de la identidad. Además, los participantes que afirman sentimientos catalanes o españoles no los relacionan con la lengua sino con los intercambios sociales que han establecido con sus iguales de origen naciona. Las intervenciones muestran también las dificultades para promover identidades múltiples desde el contexto escolar que eviten actitudes racistas y xenófobas y sirvan para promover proyectos colectivos de futuro en los que se pueda vivir desde una cierta diferencia

Bringing Funds of Family Knowledge to school. The Living Morocco Project (“برغملا شيعلا”)

The purpose of the study, grounded in sociocultural theory, is to describe the funds of knowledge of a Moroccan family living in Catalonia (Spain) in order to document how teachers can use these funds of knowledge to make direct links between students' lives and classroom teaching. The funds of knowledge approach is based on a simple premise: regardless of any socio-economical and sociocultural "deficit" that people may or may not have all families accumulate bodies of beliefs, ideas, skills and abilities based on their experiences (in areas such as their occupation or their religion). The challenge consists in connecting these bodies of educational resources with teaching practice in order to connect the curriculum with students' lives. In doing so, qualitative research can be carried out using several techniques such as self portraits, self-definition tasks, assessment of family artefacts, documenting routines through photographs, or the analysis of a person's significant circle. The results in terms of teaching practices illustrate the variety of ways teachers can make connections between home and school in ways that assist learners in their academic development. In this article, we propose using the term funds of identity to complement the concept of funds of knowledge

Lengua familiar y conocimiento de la lengua escolar en Cataluña al finalizar la Educación Infantil = Home Language and Knowledge of the School Language in Catalonia at the end of Nursery School

La infancia extranjera se escolariza en Cataluña en un programa de cambio de lengua del hogar a la escuela. Las investigaciones afirman que este alumnado tarda un mínimo de seis años en equiparar sus habilidades lingüístico-cognitivas con sus pares autóctonos, no así las habilidades conversacionales, las cuales se adquieren antes de los dos años de residencia. Sin embargo, no existen estudios sobre los efectos de la escolarización en el parvulario del alumnado alófono, así como de su lengua familiar, en relación con la adquisición de la lengua escolar. El artículo es un estudio comparativo de la adquisición del catalán de 567 autóctonos y 434 alófonos, al final del parvulario, en 50 escuelas de Cataluña que escolarizan a alumnado de origen extranjero. Las lenguas del alumnado autóctono son el catalán, el castellano y el bilingüismo catalán-castellano y las lenguas del alumnado alófono son el árabe, el soninké y el castellano. Los factores utilizados más relevantes han sido el nivel socioprofesional y educativo de las familias, el tiempo de residencia y el momento de escolarización del alumnado, el porcentaje de alumnado catalanohablante y de alumnado alófono en el aula y el contexto sociolingüístico del centro escolar. Los resultados muestran que el alumnado autóctono sabe más catalán que el alumnado alófono, pero las diferencias desaparecen respecto a algunos factores, de los cuales los más relevantes son los relacionados con las características del alumnado de las aulas. La lengua familiar del alumnado alófono no incide en sus resultados

Crítical memory of three school debates

As reflection on the education in the Escola Elisava and of the design education in general, the intervention tries to treat the debates that for many years had existed tacitly between the different academic classes, showing the critical situation that it supposes - especially for the fragile design - that one any of these classes influences over the others. From middle of the 90s, the progressive adoption generalized in the higher education of the Anglo-Saxon model ¿with clear predominance of the institutional thing¿ has showed the indicative character of the critique that here is exhibited.

Size dependence of refractive index of Si nanoclusters embedded in SiO2

he complex refractive index of SiO2 layers containing Si nanoclusters (Si-nc) has been measured by spectroscopic ellipsometry in the range from 1.5 to 5.0 eV. It has been correlated with the amount of Si excess accurately measured by x-ray photoelectron spectroscopy and the nanocluster size determined by energy-filtered transmission electron microscopy. The Si-nc embedded in SiO2 have been produced by a fourfold Si+ ion implantation, providing uniform Si excess aimed at a reliable ellipsometric modeling. The complex refractive index of the Si-nc phase has been calculated by the application of the Bruggeman effective-medium approximation to the composite media. The characteristic resonances of the refractive index and extinction coefficient of bulk Si vanish out in Si-nc. In agreement with theoretical simulations, a significant reduction of the refractive index of Si-nc is observed, in comparison with bulk and amorphous silicon. The knowledge of the optical properties of these composite layers is crucial for the realization of Si-based waveguides and light-emitting devices.

Size-dependent recombination dynamics in ZnO nanowires.

A deep understanding of the recombination dynamics of ZnO nanowires NWs is a natural step for a precise design of on-demand nanostructures based on this material system. In this work we investigate the influence of finite-size on the recombination dynamics of the neutral bound exciton around 3.365 eV for ZnO NWs with different diameters. We demonstrate that the lifetime of this excitonic transition decreases with increasing the surface-to-volume ratio due to a surface induced recombination process. Furthermore, we have observed two broad transitions around 3.341 and 3.314 eV, which were identified as surface states by studying the dependence of their life time and intensitiy with the NWs dimensions.

Size effects in the magneto-optical response of Co nanoparticles

A study of the magneto-optical (MO) spectral response of Co nanoparticles embedded in MgO as a function of their size and concentration in the spectral range from 1.4 to 4.3 eV is presented. The nanoparticle layers were obtained by sputtering at different deposition temperatures. Transmission electron microscopy measurements show that the nanoparticles have a complex structure which consists of a crystalline core having a hexagonal close-packed structure and an amorphous crust. Using an effective-medium approximation we have obtained the MO constants of the Co nanoparticles. These MO constants are different from those of continuous Co layers and depend on the size of the crystalline core. We associate these changes with the size effect of the intraband contribution to the MO constants, related to a reduction of the relaxation time of the electrons into the nanoparticles.