Brans-Dicke-type theories and avoidance of the cosmological singularity

We tudy flat Friedmann-Robertson-Walker cosmology in Brans-Dicke-type theories of gravitation with minimal coupling between the scalar field and the matter fields in the Einstein frame (general relativity with an extra scalar field) for arbitrary values of the Brans-Dicke parameter $\omega>-{3/2}$. It is shown that the cosmological singularity occuring in the Einstein frame formulation of this theory is removed in the Jordan frame in the range $-{3/2}<\omega<\leq-{4/3}$. This result is interpreted in the ligth of a viewpoint (first presented in reference gr-qc/9905071) asserting that both Jordan frame and Einstein frame formulations of general relativity are physically equivalent. The implications of the obtained result for string theory are outlined.Comment: 9 pages, LaTeX, no figures. Improved version accepted for publication in PR

Evaluación de la competencia clínica de tutores de residentes de medicina familiar y comunitaria

ObjetivoDescribir la primera experiencia de una evaluación clínica objetiva y estructurada (ECOE) a tutores de residentes realizada en la comunidad autónoma de AndalucíaDiseñoObservacional descriptivoEmplazamientoUnidad Docente de Medicina Familiar y Comunitaria de HuelvaParticipantesTutores de residentes de medicina familiar y comunitariaMediciones principalesLos componentes competenciales que se consensuaron y ponderaron fueron los siguientes: anamnesis, exploración física, comunicación,habilidades técnicas, manejo, atención a la familia y actividades preventivas. La selección de las 10 situaciones clínicas de las que constaba la prueba se realizó utilizando unos criterios de priorización según la prevalencia, gravedad clínica, importancia de la prevención y del diagnóstico precoz, complejidad del caso, evaluación de la capacidad resolutiva del médico y simplicidad evaluativaResultadosRealizaron la ECOE 13 tutores. La edad media ± desviación estándar de los participantes fue de 42,8 ± 3,64 años. La prueba tuvo un coeficiente de fiabilidad (alfa de Cronbach) de 0,73. Por lo que se refiere a los resultados por participantes, la media global fue de 73 ± 6,2. Al analizar los resultados para los diferentes componentes competenciales, los mejores resultados se obtuvieron en la atención a la familia, la comunicación y las habilidades técnicasConclusionesLas pruebas de evaluación clínica objetiva y estructurada pueden ser útiles para la valoración de los tutores, con el objetivo de orientar su formación en los puntos débiles e incluso para, en un futuro no muy lejano, servir como instrumento para acreditar y reacreditar a los tutores de residentes de medicina familiar y comunitariaObjectivesWe show the first experience of the application of an objetive and structured clinical evaluation (OSCE) procedure to family medicine trainers, that has been carried out in Andalucia. The objective is to use a competence evaluation instrument that, in the short term, will be used not only for trainer accreditation but also for other public sanitary professionalsParticipantsTutors of family and commnity medicine residentsDesignObservational descriptiveSettingEducational unity of family medicinePrincipal measurementsThe competencial components to be assessed are the following: anamnesis, physical exploration, communication, technical skill, management, family attention y preventive activities. The clinical situations were selected using the following priority criteria: prevalence, clinical gravity, prevention and early diagnosis importance, case complexity, doctor's capacity of evaluation and simplicityResultsThirteen family medicine trainers took part in the OSCE. Their average age was 42.8±3.6 years. The test had an overall reliability coefficient (Cronbach's alpha) of 0.73. The overall mean score of the participants was 73±6.2. The best results about the competencial components were family attention, communication and technical skillConclusionsThe OSCE can be a convenient tool for family medical trainer evaluation, helping to orientate their education in the weak points and, in the near future, it can also be used as an instrument do accredit family medicine trainer

La estrategia Educativa 2020 o las limitaciones del Banco Mundial para promover el "aprendizaje para todos"

La nueva Estrategia Educativa 2020 del Banco Mundial establece las prioridades de reforma educativa en paises en vias de desarrollo para la decada siguiente. El titulo explicito de la estrategia, Aprendizaje para Todos, es un claro reconocimiento de que, mas alla de politicas centradas en el acceso, se debe hacer algo mas para asegurar que la educacion derive en experiencias positivas de aprendizaje. Sin embargo, como este articulo sostiene, las opciones de politicas explicitas y latentes en la Estrategia 2020 no son las mas adecuadas para lograr el Aprendizaje para Todos. El articulo desarrolla tres tipos de argumentos al respecto. El primero se refiere al fuerte apego del Banco a un conocimiento disciplinario y un enfoque metodológico que es insufi ciente para entender lo que aprenden los niños en la escuela y por que. El segundo argumento se refiere al sesgo pro-mercado de la Estrategia por lo que respecta a la reforma del sector publico y a nuevas formas de oferta educativa. En tercer lugar, el articulo senala las principales ausencias de la Estrategia, con especial atencion a las omisiones relacionadas con la compleja relación entre educación y pobreza.The World Bank's 2020 Education Strategy establishes the new education priorities in developing countries for the next decade. Its title, Learning for All, clearly recognizes that, beyond policies focusing on access, something else must be done to ensure that schooling involves positive learning experiences. However, as this paper argues, the 2020 Strategy explicit and latent policy options might not be adequate to achieve Learning for All. This paper develops three arguments on that matter. The fi rst one refers to the Bank's strong attachment to a disciplinary knowledge and a methodological approach that do not suffi ce to understand what children learn at school and why. The second one addresses its pro-market bias when it approaches the public sector reforms and the new forms of providing education. The last argument points out the main omissions of this Strategy, especially in what regards the complex relation between education and poverty

Is the New Mayo Clinic Quadratic Equation Useful for the Estimation of Glomerular Filtration Rate in Type 2 Diabetic Patients?

OBJECTIVE—To test the Mayo Clinic Quadratic (MCQ) equation against isotopic glomerular filtration rate, compared with the Modification of Diet in Renal Disease (MDRD) and the Cockcroft-Gault formulas, in type 2 diabetes

A divergent heritage for complex organics in Isheyevo lithic clasts

Primitive meteorites are samples of asteroidal bodies that contain a high proportion of chemically complex organic matter (COM) including prebiotic molecules such as amino acids, which are thought to have been delivered to Earth via impacts during the early history of the Solar System. Thus, understanding the origin of COM, including their formation pathway(s) and environment(s), is critical to elucidate the origin of life on Earth as well as assessing the potential habitability of exoplanetary systems. The Isheyevo CH/CBb carbonaceous chondrite contains chondritic lithic clasts with variable enrichments in 15N believed to be of outer Solar System origin. Using transmission electron microscopy (TEM-EELS) and in situ isotope analyses (SIMS and NanoSIMS), we report on the structure of the organic matter as well as the bulk H and N isotope composition of Isheyevo lithic clasts. These data are complemented by electron microprobe analyses of the clast mineral chemistry and bulk Mg and Cr isotopes obtained by inductively coupled plasma and thermal ionization mass spectrometry, respectively (MC-ICPMS and TIMS). Weakly hydrated (A) clasts largely consist of Mg-rich anhydrous silicates with local hydrated veins composed of phyllosilicates, magnetite and globular and diffuse organic matter. Extensively hydrated clasts (H) are thoroughly hydrated and contain Fe-sulfides, sometimes clustered with organic matter, as well as magnetite and carbonates embedded in a phyllosilicate matrix. The A-clasts are characterized by a more 15N-rich bulk nitrogen isotope composition (δ15N = 200–650‰) relative to H-clasts (δ15N = 50–180‰) and contain extremely 15N-rich domains with δ15N 15N-rich domains show that the lithic clast diffuse organic matter is typically more 15N-rich than globular organic matter. The correlated δ15N values and C/N ratios of nanoglobules require the existence of multiple organic components, in agreement with the H isotope data. The combined H and N isotope data suggest that the organic precursors of the lithic clasts are defined by an extremely 15N-poor (similar to solar) and D-rich component for H-clasts, and a moderately 15N-rich and D-rich component for A-clasts. In contrast, the composition of the putative fluids is inferred to include D-poor but moderately to extremely 15N-rich H- and N-bearing components. The variable 15N enrichments in H- and A-clasts are associated with structural differences in the N bonding environments of their diffuse organic matter, which are dominated by amine groups in H-clasts and nitrile functional groups in A-clasts. We suggest that the isotopically divergent organic precursors in Isheyevo clasts may be similar to organic moieties in carbonaceous chondrites (CI, CM, CR) and thermally recalcitrant organic compounds in ordinary chondrites, respectively. The altering fluids, which are inferred to cause the 15N enrichments observed in the clasts, may be the result of accretion of variable abundances of NH3 and HCN ices. Finally, using bulk Mg and Cr isotope composition of clasts, we speculate on the accretion regions of the various primitive chondrites and components and the origin of the Solar System’s N and H isotope variability

ASIME 2018 White Paper. In-Space Utilisation of Asteroids: Asteroid Composition -- Answers to Questions from the Asteroid Miners

In keeping with the Luxembourg government's initiative to support the future use of space resources, ASIME 2018 was held in Belval, Luxembourg on April 16-17, 2018. The goal of ASIME 2018: Asteroid Intersections with Mine Engineering, was to focus on asteroid composition for advancing the asteroid in-space resource utilisation domain. What do we know about asteroid composition from remote-sensing observations? What are the potential caveats in the interpretation of Earth-based spectral observations? What are the next steps to improve our knowledge on asteroid composition by means of ground-based and space-based observations and asteroid rendez-vous and sample return missions? How can asteroid mining companies use this knowledge? ASIME 2018 was a two-day workshop of almost 70 scientists and engineers in the context of the engineering needs of space missions with in-space asteroid utilisation. The 21 Questions from the asteroid mining companies were sorted into the four asteroid science themes: 1) Potential Targets, 2) Asteroid-Meteorite Links, 3) In-Situ Measurements and 4) Laboratory Measurements. The Answers to those Questions were provided by the scientists with their conference presentations and collected by A. Graps or edited directly into an open-access collaborative Google document or inserted by A. Graps using additional reference materials. During the ASIME 2018, first day and second day Wrap-Ups, the answers to the questions were discussed further. New readers to the asteroid mining topic may find the Conversation boxes and the Mission Design discussions especially interesting.Comment: Outcome from the ASIME 2018: Asteroid Intersections with Mine Engineering, Luxembourg. April 16-17, 2018. 65 Pages. arXiv admin note: substantial text overlap with arXiv:1612.0070

Factors that hinder access to and persistence in post-compulsory education: a challenge for vulnerable groups in Spain

Post-compulsory education constitutes a stage of heightened vulnerability for certain young people who face conditions of inequality. Young people with disabilities or from socio-economically disadvantaged backgrounds, immigrants, Romani, and women are the primary vulnerable groups in Spain. In addition, other circumstances may present a challenge to gaining admission to, persisting in and successfully graduating from post-compulsory education. Although belonging to one of these groups does not present an obstacle for certain young people in the continuation of their studies, for others, being a member of a vulnerable group poses a challenge on a daily basis. This article seeks to identify the factors that render it difficult for young people belonging to vulnerable groups to continue their post-compulsory studies in Spain. This study has identified familial, personal, institutional, and systemic factors that may explain why certain young people do not have access to post-compulsory schooling or drop out before completing their studies