3,355 research outputs found

    Sprouty1 and Sprouty2 gene function in mouse lung development

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    Almost ten years after the political closing of the neoliberal cycle that framed educational reforms in Latin America in the 90s, this paper assesses their success in three countries – Argentina, Brazil and Chile. The analysis is supported by the theoretical framework developed by Martin Carnoy in his text ‘Are educational reforms working in Latin America? New perspectives’ (2002) and spin-off texts, as an alternative model to classical analysis of educational reforms and quality assurance of its various educational systems. As regards methodology, several indicators, weighted by Carnoy for consideration of success of Latin American reforms, will be used to analyze educational systems of Argentina, Brazil and Chile: (a) expansion of system access, (b) performance of the most disadvantaged intake and (c) improvement of factors associated to educational achievement. Data focus, mainly, on secondary school education since it is at this stage that the greatest difficulty is encountered. Primary education coverage is practically universal and diminishes rapidly when secondary education is considered.  In its analysis, this study compares not only the impact of reforms within and across the countries mentioned above but also on Carnoy’s proposal for analysis and traditional models of reform assessment (basically, through the study of changes in effectiveness –learning results- and internal efficiency of systems – repeat students and drop-outs). Finally, this paper raises questions about the true capacity for improvement that reform processes have had for the population of those countries –specially for Argentina- not just in educational terms but also with respect to its democratization and, considering the Conference theme: decrease in vulnerability, injustice and inequity.A casi diez años del cierre político del ciclo neoliberal que enmarcó las reformas educativas en América Latina de los años ’90, este trabajo evalúa su éxito en tres países latinoamericanos –Argentina, Brasil y Chile-. El análisis se apoya en el planteo teórico-conceptual desarrollado por Martin Carnoy en su texto “¿Están funcionando las reformas educativas en Latinoamérica? Nuevas perspectivas” y en otros derivados de aquél, como modelo alternativo a los análisis clásicos de las reformas educativas y de evaluación la calidad de sus sistemas educativos. Metodológicamente, se utilizarán diversos indicadores, ponderados por Carnoy para la consideración del éxito de las reformas latinoamericanas: (a) la expansión del acceso al sistema, (b) el desempeño de los sectores más desfavorecidos y (c) el mejoramiento de factores asociados a logros educativos. Los datos se centran, principalmente, en el nivel de educación secundaria, el nivel en donde se presenta la mayor dificultad. La cobertura del nivel primario es prácticamente total y disminuye, rápidamente, cuando se considera el nivel medio. Analíticamente, el estudio compara el impacto de las reformas en los países mencionados, y entre la propuesta de análisis de Carnoy y los modelos tradicionales de evaluación de reformas. Finalmente, interroga acerca de la verdadera capacidad de mejoramiento que los procesos de reforma han tenido para la población de esos países -especialmente para Argentina- no sólo en términos educativos sino también respecto de su democratización y, en función de la temática de la Conferencia: la disminución de la vulnerabilidad, injusticia e inequidad social.Há quase 10 anos do fechamento político do ciclo neoliberal, que teve como marco as reformas educacionais dos anos 90. Este trabalho avalia seu êxito em três países latino americanos - Argentina, Brasil e Chile. Esta análise se fundamenta no plano teórico conceitual desenvolvido por Martin Carnoy em seu texto: "Estão Funcionando as reformas educacionais na América Latina? Novas Perspectivas", e outros derivados que, como modelo alternativo para uma análise clássica das reformas educacionais e avaliação da qualidade do Sistema Educacional.Metodologiamente, se utilizaram diversos indicadores, poderados por Carnoy para a consideração do êxito das reformas latino americanas: (a) A expansão do acesso ao Sistema, (b) O desempenho dos setores mais desfavorecidos e (c) O melhoramento de fatores associados a realizações educacionais. Os dados se concentram, principalmente, no nível da educação secundária, o nível onde se apresenta a maior dificuldade. A Cobertura do nível primário é praticamente total e reduz, rapidamente, quando se considera o nível médio. Analiticamente, o estudo compara o impacto das reformas nos países mencionados, entre a proposta de análise de Carnoy e dos modelos tradicionais de avaliação das reformas. Finalmente, questiona acerca da verdadeira capacidade de melhorias que os processos da reforma tiveram para a população destes países, especialmente para Argentina, não só em termos educacionais como também a respeito de sua democratização, e em função da temática da conferência: A redução da vulnerabilidade, injustiça e desigualdade social

    Compton Echoes from Gamma-ray Bursts

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    Recent observations of gamma-ray bursts (GRBs) have provided growing evidence for collimated outflows and emission, and strengthened the connection between GRBs and supernovae. If massive stars are the progenitors of GRBs, the hard photon pulse will propagate in the pre-burst, dense environment. Circumstellar material will Compton scatter the prompt GRB radiation and give rise to a reflection echo. We calculate luminosities, spectra, and light curves of such Compton echoes in a variety of emission geometries and ambient gas distributions, and show that the delayed hard X-ray flash from a pulse propagating into a red supergiant wind could be detectable by Swift out to z~0.2. Independently of the gamma-ray spectrum of the prompt burst, reflection echoes will typically show a high-energy cutoff between m_ec^2/2 and m_ec^2 because of Compton downscattering. At fixed burst energy per steradian, the luminosity of the reflected echo is proportional to the beaming solid angle, Omega_b, of the prompt pulse, while the number of bright echoes detectable in the sky above a fixed limiting flux increases as Omega_b^{1/2}, i.e. it is smaller in the case of more collimated jets. The lack of an X-ray echo at one month delay from the explosion poses severe constraints on the possible existence of a lateral GRB jet in SN 1987A. The late r-band afterglow observed in GRB990123 is fainter than the optical echo expected in a dense red supergiant environment from a isotropic prompt optical flash. Significant MeV delayed emission may be produced through the bulk Compton (or Compton drag) effect resulting from the interaction of the decelerating fireball with the scattered X-ray radiation.Comment: LaTeX, 18 pages, 4 figures, revised version accepted for publication in the Ap

    Hepatic Arterial Therapy with Drug-Eluting Beads in the Management of Metastatic Bronchogenic Carcinoma to the Liver: A Multi-Institutional Registry

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    Introduction. There has been limited information reported on the use of hepatic arterial therapy in liver dominant hepatic metastases arising from lung cancer. The aim of this study was to evaluate the safety and efficacy of hepatic arterial therapy in the treatment of liver dominant hepatic metastases arising from lung cancer. Methods. Thirteen patients underwent a total of 30 treatment sessions with Drug-Eluting Beads. Eight of the thirteen received only doxorubicin DEB (17 of the total treatments), and four patients received Irinotecan DEB (7 of the total treatments). Results. The planned preprocedural dosage was a median of 75 mg (range 19–200), with total hepatic dose exposure being a median of 150 mg (range 0–458), with a technical success rate of 97% in all 29 treatments. There were 4 adverse events related to treatment, but no evidence of hepatic insufficiency. Overall 6-month and 12-month response rates were 50%. After a median followup of 24 months, the median overall survival in this cohort was 14 months (range 7–48 months). Conclusion. Drug-eluting beads loaded with doxorubicin (DEBDOX) or irinotecan (DEBIRI) can be safely and effectively used in treatment of patients with liver predominant metastatic disease from lung cancer

    The effects of creatine pyruvate and creatine citrate on performance during high intensity exercise

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    <p>Abstract</p> <p>Background</p> <p>A double-blind, placebo-controlled, randomized study was performed to evaluate the effect of oral creatine pyruvate (Cr-Pyr) and creatine citrate (Cr-Cit) supplementation on exercise performance in healthy young athletes.</p> <p>Methods</p> <p>Performance during intermittent handgrip exercise of maximal intensity was evaluated before (pretest) and after (posttest) 28 days of Cr-Pyr (5 g/d, n = 16), Cr-Cit (5 g/d, n = 16) or placebo (pla, 5 g/d, n = 17) intake. Subjects performed ten 15-sec exercise intervals, each followed by 45 sec rest periods.</p> <p>Results</p> <p>Cr-Pyr (p < 0.001) and Cr-Cit (p < 0.01) significantly increased mean power over all intervals. Cr-Cit increased force during the first and second interval (p < 0.01) compared to placebo. The effect of Cr-Cit on force decreased over time and the improvement was not significant at the sixth and ninth interval, whereas Cr-Pyr significantly increased force during all intervals (p < 0.001). Cr-Pyr (p < 0.001) and Cr-Cit (p < 0.01) resulted in an increase in contraction velocity, whereas only Cr-Pyr intake significantly (p < 0.01) increased relaxation velocity. Oxygen consumption measured during rest periods significantly increased with Cr-Pyr (p < 0.05), whereas Cr-Cit and placebo intake did not result in significant improvements.</p> <p>Conclusion</p> <p>It is concluded that four weeks of Cr-Pyr and Cr-Cit intake significantly improves performance during intermittent handgrip exercise of maximal intensity and that Cr-Pyr might benefit endurance, due to enhanced activity of the aerobic metabolism.</p

    Data-Driven Regionalization of Decarbonized Energy Systems for Reflecting Their Changing Topologies in Planning and Optimization

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    The decarbonization of energy systems has led to a fundamental change in their topologysince generation is shifted to locations with favorable renewable conditions. In planning, this changeis reflected by applying optimization models to regions within a country to optimize the distributionof generation units and to evaluate the resulting impact on the grid topology. This paper proposesa globally applicable framework to find a suitable regionalization for energy system models witha data-driven approach. Based on a global, spatially resolved database of demand, generation,and renewable profiles, hierarchical clustering with fine-tuning is performed. This regionalizationapproach is applied by modeling the resulting regions in an optimization model including asynthesized grid. In an exemplary case study, South Africa’s energy system is examined. The resultsshow that the data-driven regionalization is beneficial compared to the common approach of usingpolitical regions. Furthermore, the results of a modeled 80% decarbonization until 2045 demonstratethat the integration of renewable energy sources fundamentally changes the role of regions withinSouth Africa’s energy system. Thereby, the electricity exchange between regions is also impacted,leading to a different grid topology. Using clustered regions improves the understanding and analysisof regional transformations in the decarbonization process
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