A skyrmion-based spin-torque nano-oscillator

A model for a spin-torque nano-oscillator based on the self-sustained oscillation of a magnetic skyrmion is presented. The system involves a circular nanopillar geometry comprising an ultrathin film free magnetic layer with a strong Dzyaloshinkii-Moriya interaction and a polariser layer with a vortex-like spin configuration. It is shown that spin-transfer torques due to current flow perpendicular to the film plane leads to skyrmion gyration that arises from a competition between geometric confinement due to boundary edges and the vortex-like polarisation of the spin torques. A phenomenology for such oscillations is developed and quantitative analysis using micromagnetics simulations is presented. It is also shown that weak disorder due to random anisotropy variations does not influence the main characteristics of the steady-state gyration.Comment: 15 pages, 6 figure

New version of the Pediatric Evaluation of Disability Inventory (PEDI-CAT): translation, cultural adaptation to Brazil and analyses of psychometric properties

BACKGROUND: The Pediatric Evaluation of Disability Inventory-Computer Adaptive Test (PEDI-CAT), developed with innovative measurement methodologies, evaluates functioning of children and youth, from 0 to 21 years, with different health conditions. It is a revision of an earlier instrument (PEDI) that has been used in national and international clinical practice and research. It was felt to be necessary to make this new version (PEDI-CAT) available in Brazil. OBJECTIVES: Translate and culturally adapt the PEDI-CAT to the Brazilian-Portuguese language and test its psychometric properties. METHOD: This methodological study was developed through the following stages: (1) translation, (2) synthesis, (3) back-translation, (4) revision by an expert committee, (5) testing of the pre-final version, and (6) evaluation of the psychometric properties. The 276 translated PEDI-CAT items were divided into three age groups (0-7, 8-14, and 15-21 years). RESULTS: The PEDI-CAT translation followed all six stages. The adaptations incorporated cultural and socioeconomic class specificities. The PEDI-CAT/Brazil showed good indices of inter-examiner (intraclass correlation coefficient-ICC=0.83-0.89) and test-retest (ICC=0.96-0.97) reliability, good internal consistency (0.99) and small standard error of measurement in all three age groups (0.12-0.17). Factor analyses grouped the items from the three functional skills domains into one factor, and items from the responsibility scale into three factors, supporting the adequacy of these factor solutions to the conceptual structure of the instrument and the developmental model. CONCLUSION: The PEDI-CAT/Brazil is a theoretically consistent, culturally appropriate, and reliable instrument. Its availability in Brazil will contribute to the evaluation and measurement of functional outcomes from clinical interventions, longitudinal follow-up, and rehabilitation research

Seleção e avaliação de matrizes de guaranazeiro para produção de sementes (Paulinia cupana var. Sorbilis Mart. Duke).

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Avaliação de sistema de produção alternativo de milho em monocultivo.

O sistema de produção preconizado apresenta sérias limitações à obtenção de ganhos de produtividade da cultura, mesmo nas áreas de solos mais férteis, por apresentar poucas alternativas tecnológicas. Face impirismo que lhe é peculiar, o cultivo do milho em Porto Velho constitui-se num desafio ao produtor e uma atividade de alto risco. A tecnologia disponível pela pesquisa poderá melhorar o desempenho técnico e econômico da cultura, imprimindo algumas mudanças ao sistema proposto para as demais áreas do Estado. Com a finalidade de viabilizar a produção de milho em Porto Velho, algumas inferências foram feitas ao modelo preconizado, buscando novas opções de escolha ao produtor e menor margem de riscos econômicos.bitstream/item/57012/1/PA-1555-0001.pd

Basketball game-related statistics that discriminate between teams season-long success

The aim of the present study was to identify the game-related statistics that discriminate between season-long successful and unsuccessful basketball teams participating in the Spanish Basketball League (LEB1). The sample included all 145 average records per season from the 870 games played between the 2000-2001 and the 2005-2006 regular seasons. The following game-related statistics were gathered from the official box scores of the Spanish Basketball Federation: 2- and 3-point field-goal attempts (both successful and unsuccessful), free-throws (both successful and unsuccessful), defensive and offensive rebounds, assists, steals, turnovers, blocks (both made and received), and fouls (both committed and received). To control for season variability, all results were normalized to minutes played each season and then converted to z-scores. The results allowed discrimination between best and worst teams' performances through the following game-related statistics: assists (SC=0.47), steals (SC=0.34), and blocks (SC=0.30). The function obtained correctly classified 82.4% of the cases. In conclusion, season-long performance may be supported by players' and teams' passing skills and defensive preparation