575 research outputs found

    Resultados de oito aplicações do Teste do Progresso na Faculdade de Medicina da Universidade de São Paulo

    Get PDF
    BACKGROUND: Progress testing is a longitudinal tool for evaluating knowledge gains during the medical school years. OBJECTIVES: (1) To implement progress testing as a form of routine evaluation; (2) to verify whether cognitive gain is a continuous variable or not; and (3) to evaluate whether there is loss of knowledge relating to basic sciences in the final years of medical school. METHODS: A progress test was applied twice a year to all students from 2001 to 2004. The mean percentage score was calculated for each school year, employing ANOVA with post hoc Bonferroni test evaluation for each test. RESULTS: Progress testing was implemented as a routine procedure over these 4 years. The results suggest a cognitive gain from first to sixth year in all eight tests, as a continuum (P for trend < .0001). Gain was found to be continuous for basic sciences (taught during the first 2 years), clinical sciences (P < .0001), and clerkship rotation (P < .0001). There was no difference between the performance of men and women. CONCLUSION: Progress testing was implemented as a routine, applied twice a year. Data suggest that cognitive gain during medical training appears to be a continuum, even for basic science issues.O Teste do Progresso foi introduzido na Faculdade de Medicina da Universidade de São Paulo em 2001. OBJETIVO: (1) Testar a viabilidade da aplicação rotineira do teste; (2) verificar se o ganho de conhecimentos era progressivo e contínuo durante a graduação; (3) determinar se esse ganho de conhecimento inclui também as disciplinas do curso básico. MÉTODOS: O teste foi aplicado duas vezes por ano entre 2001-2004. Em cada teste, calculou-se o escore médio de acertos por ano letivo usando-se ANOVA com correção de Bonferroni para múltiplas comparações. RESULTADOS: O Teste do Progresso foi implementado como rotina entre 2001-2004. Os resultados sugerem um ganho cognitivo contínuo e progressivo ao longo da graduação (P < 0,0001) nos oito testes aplicados até o momento. Esse ganho seria significativo mesmo para as disciplinas do curso básico (P < 0,05), curso clínico (P < 0.0001) e internato (P < 0.0001). Não houve diferença de performance em função do gênero. CONCLUSÃO: O Teste do Progresso foi implementado como rotina, sendo aplicado semestralmente. Os resultados sugerem que o ganho cognitivo parece ser contínuo e progressivo mesmo para as disciplinas do básico ao longo dos seis anos

    Interplay between pulsations and mass loss in the blue supergiant 55 Cygnus = HD 198478

    Get PDF
    Blue supergiant stars are known to display photometric and spectroscopic variability that is suggested to be linked to stellar pulsations. Pulsational activity in massive stars strongly depends on the star's evolutionary stage and is assumed to be connected with mass-loss episodes, the appearance of macroturbulent line broadening, and the formation of clumps in the wind. To investigate a possible interplay between pulsations and mass-loss, we carried out an observational campaign of the supergiant 55 Cyg over a period of five years to search for photospheric activity and cyclic mass-loss variability in the stellar wind. We modeled the H, He I, Si II and Si III lines using the nonlocal thermal equilibrium atmosphere code FASTWIND and derived the photospheric and wind parameters. In addition, we searched for variability in the intensity and radial velocity of photospheric lines and performed a moment analysis of the line profiles to derive frequencies and amplitudes of the variations. The Halpha line varies with time in both intensity and shape, displaying various types of profiles: P Cygni, pure emission, almost complete absence, and double or multiple peaked. The star undergoes episodes of variable mass-loss rates that change by a factor of 1.7-2 on different timescales. We also observe changes in the ionization rate of Si II and determine a multiperiodic oscillation in the He I absorption lines, with periods ranging from a few hours to 22.5 days. We interpret the photospheric line variations in terms of oscillations in p-, g-, and strange modes. We suggest that these pulsations can lead to phases of enhanced mass loss. Furthermore, they can mislead the determination of the stellar rotation. We classify the star as a post-red supergiant, belonging to the group of alpha Cyg variables.Comment: 20 pages, 18 figures, 3 tables, accepted to Astronomy & Astrophysic

    Magnetic Determination of Hc2H_{c2} under Accurate Alignment in (TMTSF)2_2ClO4_4

    Full text link
    Cantilever magnetometry has been used to measure the upper critical magnetic field Hc2H_{c2} of the quasi-one dimensional molecular organic superconductor (TMTSF)2_2ClO4_4. From simultaneous resistivity and torque magnetization experiments conducted under precise field alignment, Hc2H_{c2} at low temperature is shown to reach 5T, nearly twice the Pauli paramagnetic limit imposed on spin singlet superconductors. These results constitute the first thermodynamic evidence for a large Hc2H_{c2} in this system and provide support for spin triplet pairing in this unconventional superconductorComment: Submitted July 1, 2003, Accepted December 9, 2003, Physical Review Letter

    SO(4) Theory of Competition between Triplet Superconductivity and Antiferromagnetism in Bechgaard Salts

    Full text link
    Motivated by recent experiments with Bechgaard salts, we investigate the competition between antiferromagnetism and triplet superconductivity in quasi one-dimensional electron systems. We unify the two orders in an SO(4) symmetric framework, and demonstrate the existence of such symmetry in one-dimensional Luttinger liquids. SO(4) symmetry, which strongly constrains the phase diagram, can explain coexistence regions between antiferromagnetic, superconducting, and normal phases, as observed in (TMTSF)2_2PF6_6. We predict a sharp neutron scattering resonance in superconducting samples.Comment: 5 pages, 3 figures; Added discussion of applicability of SO(4) symmetry for strongly anisotropic Fermi liquids; Added reference

    Possible Triplet Electron Pairing and an Anisotropic Spin Susceptibility in Organic Superconductors (TMTSF)_2 X

    Full text link
    We argue that (TMTSF)_2 PF_6 compound under pressure is likely a triplet superconductor with a vector order parameter d(k) \equiv (d_a(k) \neq 0, d_c(k) = ?, d_{b'}(k) = 0); |d_a(k)| > |d_c(k)|. It corresponds to an anisotropic spin susceptibility at T=0: \chi_{b'} = \chi_0, \chi_a \ll \chi_0, where \chi_0 is its value in a metallic phase. [The spin quantization axis, z, is parallel to a so-called b'-axis]. We show that the suggested order parameter explains why the upper critical field along the b'-axis exceeds all paramagnetic limiting fields, including that for a nonuniform superconducting state, whereas the upper critical field along the a-axis (a \perp b') is limited by the Pauli paramagnetic effects [I. J. Lee, M. J. Naughton, G. M. Danner and P. M. Chaikin, Phys. Rev. Lett. 78, 3555 (1997)]. The triplet order parameter is in agreement with the recent Knight shift measurements by I. J. Lee et al. as well as with the early results on a destruction of superconductivity by nonmagnetic impurities and on the absence of the Hebel-Slichter peak in the NMR relaxation rate.Comment: 4 pages, 1 eps figur

    Superconductivity and Antiferromagnetism in Quasi-one-dimensional Organic Conductors

    Get PDF
    We review the current understanding of superconductivity in the quasi-one-dimensional organic conductors of the Bechgaard and Fabre salt families. We discuss the interplay between superconductivity, antiferromagnetism, and charge-density-wave fluctuations. The connection to recent experimental observations supporting unconventional pairing and the possibility of a triplet-spin order parameter for the superconducting phase is also presented.Comment: (v1) 30 pages, 13 figures; Review article for the 20th anniversary of high-Tc superconductivity, to appear in J. Low Temp. Phys. (v2) 1 Ref. adde

    Molecular characterization of old local grapevine varieties from South East European countries

    Get PDF
    South East European (SEE) viticulture partially relies on native grapevine varieties, previously scarcely described. In order to characterize old local grapevine varieties and assess the level of synonymy and genetic diversity from SEE countries, we described and genotyped 122 accessions from Albania, Federation of Bosnia and Herzegovina (B&amp;H), Croatia, Macedonia, Moldova, Montenegro, Republika Srpska (Bosnia and Herzegovina) and Romania on nine most commonly used microsatellite loci. As a result of the study a total of 86 different genotypes were identified. All loci were very polymorphic and a total of 96 alleles were detected, ranging from 8 to 14 alleles per locus, with an average allele number of 10.67. Overall observed heterozygosity was 0.759 and slightly lower than expected (0.789) while gene diversity per locus varied between 0.600 (VVMD27) and 0.906 (VVMD28). Eleven cases of synonymy and three of homonymy have been recorded for samples harvested from different countries. Cultivars with identical genotypes were mostly detected between neighboring countries. No clear differentiation between countries was detected although several specific alleles were detected. The integration of the obtained genetic data with ampelographic ones is very important for accurate identification of the SEE cultivars and provides a significant tool in cultivar preservation and utilization.
    corecore