Orbits and masses in the young triple system TWA 5

We aim to improve the orbital elements and determine the individual masses of the components in the triple system TWA 5. Five new relative astrometric positions in the H band were recorded with the adaptive optics system at the Very Large Telescope (VLT). We combine them with data from the literature and a measurement in the Ks band. We derive an improved fit for the orbit of TWA 5Aa-b around each other. Furthermore, we use the third component, TWA 5B, as an astrometric reference to determine the motion of Aa and Ab around their center of mass and compute their mass ratio. We find an orbital period of 6.03+/-0.01 years and a semi-major axis of 63.7+/-0.2 mas (3.2+/-0.1 AU). With the trigonometric distance of 50.1+/-1.8 pc, this yields a system mass of 0.9+/-0.1 Msun, where the error is dominated by the error of the distance. The dynamical mass agrees with the system mass predicted by a number of theoretical models if we assume that TWA5 is at the young end of the age range of the TW Hydrae association. We find a mass ratio of M_Ab / M_Aa = 1.3 +0.6/-0.4, where the less luminous component Ab is more massive. This result is likely to be a consequence of the large uncertainties due to the limited orbital coverage of the observations.Comment: 9 pages, 8 figures, accepted by Astronomy and Astrophysic

Transdisciplinary vision of digital architecture through computational methods of mapping, analysis and visualization

Architectural practice is changing not only with computers but also with the use of other disciplines. It is important to establish how architecture started to change. This research aims to draw a historic perspective of transdisciplinary digital architecture through the work of key personalities by establishing links between them and their relevance to nowadays architecture.info:eu-repo/semantics/publishedVersio

The roots of 4IR in architecture: a military drawing machine used for space perception in architecture

This paper analyses how architecture became a pioneer discipline in digital interactivity research. It describes how that pioneer research derives from a lineage of researchers whose work spans more than two decades beginning in the early fifties. Military funds enabled the creation of the first computer graphic interfaces that evolved into a - drawing machine", the first interactive CAD, that made possible the role of architecture as a pioneering discipline in interactivity research. It is expected to demonstrate that the same architecture that nowadays uses mainly interactive digital design was one of first disciplines to research interactivity addressing a gap in the study of the link between architecture and interactivity.info:eu-repo/semantics/publishedVersio

The possible importance of synchrotron/inverse Compton losses to explain fast mm-wave and hard X-ray emission of a solar event

The solar burst of 21 May 1984, presented a number of unique features. The time profile consisted of seven major structures (seconds), with a turnover frequency of greater than or approximately 90 GHz, well correlated in time to hard X-ray emission. Each structure consisted of multiple fast pulses (0.1 seconds), which were analyzed in detail. A proportionality between the repetition rate of the pulses and the burst fluxes at 90 GHz and greater than or approximately 100 keV hard X-rays, and an inverse proportionality between repetition rates and hard X-ray power law indices were found. A synchrotron/inverse Compton model was applied to explain the emission of the fast burst structures, which appear to be possible for the first three or four structures

CARACTERIZAÇÃO E PROGNÓSTICO A CURTO PRAZO DOS UTILIZADORES DA VIA VERDE DO AVC NO NORTE DE PORTUGAL

CARACTERIZAÇÃO E PROGNÓSTICO A CURTO PRAZO DOS UTILIZADORES DA VIA VERDE DO AVC NO NORTE DE PORTUGAL Mariana Moutinho1, Rui Magalhães2, Maria Carolina Silva2, Manuel Correia3 1Curso de Mestrado Integrado em Medicina, ICBAS/UP. 2Departamento de Estudo de Populações, ICBAS/UP. 3Serviço de Neurologia, HSA/CHP e ICBAS/UP. Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto (ICBAS/UP), Porto. Hospital de Santo António, Centro Hospitalar do Porto (HSA/CHP), Porto. Introdução Em 2002 Portugal detinha ainda uma das mais altas taxas de mortalidade por doenças cerebrovasculares de entre os países europeus. Várias estratégias foram adoptadas para melhorar quer a prevenção da doença quer o seu tratamento, e de entre estas últimas pode salientar-se a criação da Via Verde do AVC. O objectivo deste trabalho é descrever a utilização e resultados desta estratégia no contexto de um registo prospectivo comunitário de acidentes neurológicos. Metodologia Foram registados todos os AVCs ocorridos entre 1 de Outubro de 2009 e 30 de Setembro de 2010 nos utentes inscritos no agrupamento de centros de saúde do Porto Ocidental e nos centros de saúde de Mirandela e Vila Pouca de Aguiar. Para a detecção de casos utilizaram-se múltiplas fontes de informação: notificação via plataforma WEB, e-mail e Alerta P1 e pesquisas sistemáticas em registos disponibilizados pelas entidades envolvidas no estudo - urgências hospitalares, listas de altas, procedimentos de diagnóstico, óbitos, Via Verde do AVC e serviço de atendimento em situações de urgência (SASU). Resultados Ocorreram 600 AVCs em 241.000 habitantes (taxa de ataque de 2,5/1.000) e 434 primeiros na vida (taxa de incidência de 1,8/1.000). Foram registados 72 acessos à VV nesta população, dos quais 48 (66,7%) foram diagnosticados como AVC. Considerando os quatro critérios de activação da VV (idade≤80 anos, independência funcional, um de três sinais e tempo após episódio≤3 horas), só 95 (15,9%) doentes a poderiam utilizar, e dos actuais utilizadores, apenas 56,3% satisfaziam esses critérios. A janela terapêutica (19,5%) ou a idade> 80 anos (7,3%) só por si impediriam 154 (26,8%) doentes de accionar a VV. Nos doentes com critérios de activação (n=95), foram internados 96,3% pela VV externa, 83,3% pela VV intra-hospitalar e 64,0% dos restantes; a fibrinólise foi realizada em 77,3%, 36,4% e 17,4% dos doentes com enfarte cerebral, respectivamente. O Rankin pós-AVC é mais grave (4/5) nos utilizadores da VV externa (70,3% vs. 35,3%), mas estes apresentam mais assiduamente os três sinais de AVC (44,4% vs. 16,2%). Ajustando para a idade, sexo e número de sinais, o risco de incapacidade grave pós-AVC não é significativamente diferente no acesso pela VV externa (RP=2,9; IC 95%: 0,8-10,2), bem como a taxa de letalidade. Conclusões Os critérios de activação da VV do AVC são muito restritivos. Embora seja accionada mais frequentemente nas situações clínicas mais graves, impedindo a eventual realização de fibrinólise, a proporção de doentes que a realizou é relativamente alta em comparação com outros estudos. Apresentador: Mariana Moutinho, Aluna do Curso de Mestrado Integrado em Medicina, ICBAS/UP

Short-lived solar burst spectral component at f approximately 100 GHz

A new kind of burst emission component was discovered, exhibiting fast and distinct pulses (approx. 60 ms durations), with spectral peak emission at f approx. 100 GHz, and onset time coincident to hard X-rays to within approx. 128 ms. These features pose serious constraints for the interpretation using current models. One suggestion assumes the f approx. 100 GHz pulses emission by synchrotron mechanism of electrons accelerated to ultrarelativistic energies. The hard X-rays originate from inverse Compton scattering of the electrons on the synchrotron photons. Several crucial observational tests are needed for the understanding of the phenomenon, requiring high sensitivity and high time resolution (approx. 1 ms) simultaneous to high spatial resolution (0.1 arcsec) at f approx. 110 GHz and hard X-rays

The possible importance of synchrotron/inverse Compton losses to explain fast MM-wave and hard X-ray emission of a solar event

The solar burst of 21 May 1984 presented a number of unique features. The time profile consisted of seven major structures (seconds), with a turnover frequency or approx. 90 GHz, well correlated in time to hard X-ray emission. Each structure consisted of multiple fast pulses (.1 seconds), which were analyzed in detail. A proportionality between the repetition rate of the pulses and the burst fluxes at 90 GHz and or approx. 100 keV hard X-rays, and an inverse proportionality between repetition rates and hard X-rays power law indices have been found. A synchrotron/inverse Compton model has been applied to explain the emission of the fast burst structures, which appear to be possible for the first three or four structures

A video object generation tool allowing friendly user interaction

In this paper we describe an interactive video object segmentation tool developed in the framework of the ACTS-AC098 MOMUSYS project. The Video Object Generator with User Environment (VOGUE) combines three different sets of automatic and semi-automatic-tool (spatial segmentation, object tracking and temporal segmentation) with general purpose tools for user interaction. The result is an integrated environment allowing the user-assisted segmentation of any sort of video sequences in a friendly and efficient manner.Peer ReviewedPostprint (published version

A new class of solar burst with MM-wave emission but only at the highest frequency (90 GHz)

High sensitivity and high time resolution solar observations at 90 GHz (lambda = 3.3 mm) have identified a unique impulsive burst on May 21, 1984 with emission that was more intense at this frequency than at lower frequencies. The first major time structure of the burst was over 10 times more intense at 90 GHz than at 30 GHz, 7 GHz, or 2.8 GHz.Only 6 seconds later, the 30 GHz impulsive structures started to be observed but still with lower intensity than at 90 GHz. Hard X-ray time structures at energies above 25 keV were almost identical to the 90 GHZ structures (to better than one second). All 90 GHz major time structures consisted of trains of multiple subsecond pulses with rise times as short as 0.03 sec and amplitudes large compared to the mean flux. When detectable, the 30 GHz subsecond pulses had smaller relative amplitude and were in phase with the corresponding 90 GHz pulses