3D RECONSTRUCTION ACCURACY OF TWO MOVING MOTION ANALYSIS SYSTEMS: PRELIMINARY RESULTS

The purpose of this study was to compare the 3D reconstruction accuracy, through a rigid bar test, provided by two moving systems, optoelectronic cameras (MOCAP) and action sport cameras (ASC). The cameras were fixed in the same rolling rigid structure (4.4 × 4.0 × 2.5 m) and the data were acquired simultaneously by the two motion analysis systems. Algorithms were previously developed to perform the roto-translation of the global coordinate system from reference points arranged on the floor, while the cameras and the structure were moving (40 m, antero-posterior direction). The mean inter-markers distance was 598.93 mm and 585.27 mm, and the standard deviation was 6.20 mm and 2.23 mm, by ASC and MOCAP. Despite the ASC had a performance almost 3 times worse than the MOCAP, the ASC is a more portable system and less expensive

REQUIRED COEFFICIENT OF FRICTION ANALYSES IN RUNNING

The purpose of this study was to analyze the possible alterations in the required coefficient of friction (RCOF) in running under the following conditions: a) barefoot against shod; b) self-selected velocity and cadence versus imposed cadence and c) along three running phases (initial contact, mid-stance and propulsion). Two Kistler force plates were used to measure the horizontal and vertical components of ground reaction forces in order to calculate the RCOF. Statistical differences were found for cadence and phase factors. Barefoot-Shod conditions did not present statistical differences. An interaction between velocity and phase of cycle was found. At propulsion phase, an increased RCOF were revealed, especially with the interaction of an imposed cadence. In conclusion, the present study supports the relevance of RCOF as a variable affecting and being affected during running to be taken into consideration at many experimental conditions

Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy

We review HB stars in a broad astrophysical context, including both variable and non-variable stars. A reassessment of the Oosterhoff dichotomy is presented, which provides unprecedented detail regarding its origin and systematics. We show that the Oosterhoff dichotomy and the distribution of globular clusters (GCs) in the HB morphology-metallicity plane both exclude, with high statistical significance, the possibility that the Galactic halo may have formed from the accretion of dwarf galaxies resembling present-day Milky Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the second-parameter problem is presented. A technique is proposed to estimate the HB types of extragalactic GCs on the basis of integrated far-UV photometry. The relationship between the absolute V magnitude of the HB at the RR Lyrae level and metallicity, as obtained on the basis of trigonometric parallax measurements for the star RR Lyrae, is also revisited, giving a distance modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are studied. Finally, the conductive opacities used in evolutionary calculations of low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and Space Scienc

Solar Coronal Plumes

Polar plumes are thin long ray-like structures that project beyond the limb of the Sun polar regions, maintaining their identity over distances of several solar radii. Plumes have been first observed in white-light (WL) images of the Sun, but, with the advent of the space era, they have been identified also in X-ray and UV wavelengths (XUV) and, possibly, even in in situ data. This review traces the history of plumes, from the time they have been first imaged, to the complex means by which nowadays we attempt to reconstruct their 3-D structure. Spectroscopic techniques allowed us also to infer the physical parameters of plumes and estimate their electron and kinetic temperatures and their densities. However, perhaps the most interesting problem we need to solve is the role they cover in the solar wind origin and acceleration: Does the solar wind emanate from plumes or from the ambient coronal hole wherein they are embedded? Do plumes have a role in solar wind acceleration and mass loading? Answers to these questions are still somewhat ambiguous and theoretical modeling does not provide definite answers either. Recent data, with an unprecedented high spatial and temporal resolution, provide new information on the fine structure of plumes, their temporal evolution and relationship with other transient phenomena that may shed further light on these elusive features

Sementes contra a varíola: Joaquim Vás e a tradução científica das pevides de bananeira brava em Goa, Índia (1894-1930) Seeds against smallpox: Joaquim Vás and the scientific translation of bananeira brava seeds in Goa, India (1894-1930)

Em 1914, em Goa, antiga colônia portuguesa na Índia, o médico António Joaquim Vás anunciou a descoberta de um fabuloso tratamento contra a varíola: a aplicação clínica das pevides, ou sementes, de bananeira brava, medicamento de origem vegetal extraído das práticas médicas indianas. Este artigo investiga as circunstâncias do sucesso e insucesso dessa descoberta. A constituição das pevides de bananeira brava como medicamento contra a varíola, no início do século XX, é interpretada com base no conceito de tradução científica. Argumenta-se que a tradução das pevides - de atividade indígena a terapêutica científica - constitui um caso de criação de quasi-medicamentos, uma tradução média. Embora habitando um lugar problemático no programa de tradução científica, as pevides circularam ativamente no interior da própria ciência, persistindo contra a varíola nas práticas médicas.<br>In 1914, in the former Portuguese colony of Goa, India, the physician António Joaquim Vás announced the discovery of a wonderful treatment for smallpox, entailing clinical application of seeds from the bananeira brava (Heliconia biahi Sw.m.), a plant remedy allegedly derived from Indian medical practices. The present article explores the circumstances surrounding the successes and failures of this discovery. The concept of scientific translation is used to interpret the transformation of bananeira bravaseeds into an early twentieth-century remedy for smallpox. This transfer from indigenous use to scientific therapeutics constitutes the creation of a quasi-medicine, that is, a case of 'medium translation'. Although these seeds occupy a problematic place within the program of scientific translation, they enjoyed active circulation within science and remained a part of medical practices for combating smallpox