The OH-streamer in Sgr A revisited: analysis of hydroxyl absorption within 10 pc from the Galactic centre

We study the structure and kinematics of the OH-streamer and the +80 km/s cloud and their interactions with the circumnuclear disk (CND) and with other molecular clouds in the vicinity of the Galactic centre (GC), and we map OH absorption at about 6" resolution at R $\le$ 10 pc from the GC, with about 9 km/s velocity resolution. The VLA was used to map OH line absorption at the 1665 and 1667 MHz lambda doublet main lines towards the Sagittarius A complex. Strong OH absorption was found in the OH-streamer, the southern streamer (SS), the +20, +50, and +80 km/s molecular clouds, the molecular belt, the CND, the expanding molecular ring (EMR), and the high negative velocity gas (HNVG). The OH-streamer was found to comprise three parts, head, middle, and tail, and to interact with the SS/+20, +80 km/s clouds and the CND. Optical depths and column densities have been calculated for the OH-streamer and the +80 km/s cloud. The OH-streamer, the SS, the +20 and +80 km/s clouds, and the CND are intimately related in position and velocity space. The OH-streamer was found to be a clumpy object stretching in projection from the inner radius of the CND at about 1.8 pc from Sgr A* towards and partly engulfing Sgr A*. As a side result of our data, a possible link between the near side of the EMR and the CND's southwest lobe was found. Additionally, we found OH absorption against all four of the previously known Compact HII Regions A-D, located east of Sgr A East, indicating their close association with the +50 km/s cloud.Comment: Accepted for publication in Astronomy & Astrophsyics and including maps of the 1665 and 1667 MHz data cubes. These data cubes are available in electronic form at the CDS at http://vizier.u-strasbg.fr/viz-bin/Vizie

La Bellesa de l'abisme

Paul Klee no sólo fue pintor, también fue músico. La música era, al parecer, una base para su sensibilidad pictórica. No sabemos qué puede hermanar pintura y música, un arte del espacio y un arte del tiempo. Pero si probamos de esclarecer este problema, quizá podamos considerar que cuando se produce una forma que representa alguna cosa aparece también, al mismo tiempo, una vía de sentido que nos lleva a a interpretarla como un signo. En este sentido un signo formal se nos muestra según una doble cara: en tanto que representa algo, figurativamente, es un icono, y en tanto que ha sido producido (o es interpretado) en el sentido, es un símbolo. Espacio para la representación, tiempo para la significación simbólica. Podemos decir que el valor estético, la belleza, es unainestabilidad perfecta, una oscilación continua entre estas dos caras del signo: icono, símbolo. Esto hace infinito el sentido de la forma. Y vivimos pasionalmente la belleza, es como un abismo del sentido. Frente a esta disposición dinámica del mundo fenoménico, quizá sea posible decir que mediante esa oscilación, o -inestabilidad perfecta), nuestra reacción frente a las formas artísticas es la misma que frente a la naturaleza. El arte de Klee tiene esta característica: lleva la percepción de un límite a otro, convierte el mundo simbólico (cultura) en un parecer o representación (naturaleza icónica), y así nos permite experimentar el arte realmente, igual que hacemos con la vida.Paul Klee was not only a painter but also a musician. Music, itseems, was a basis for his sensibility in painting. We do not know what can bring painting and music together, an art of space, and an art of time. Trying to resolve this problem, we can consider that when a form is produced representing sornething, there appears, at the carne time, a way of meaning which leads us to interpret this form as a sign. But in this sense a formal sign shows us two faces: in as much as it represents something, figuratively, it is an icon, and in as rnuch as it is produced (or interpreted) for meaning it is a syrnbol. Space forrepresentation, time for syrnbolistic rneaning. We could say that aesthetic value, or beauty, is perfect instability, a continuous balance between these two faces of the sign: icon and symbol. This is what makes the sense of form infinite. And we live beauty passionately, as an abyss of meaning. In the presence of this dynarnic arrangement of a phenornenic world, perhaps by such a balance, or perfect instability, our reaction to artistic forrns may be the same as to nature, Klee's art has this characteristic: it conveys perception from one lirnit to another, it changes a symbolic world (culture) into an appearance or representation (icone nature), and in this way permits us to experience art really, as we do with life

Occlusion prevents the use of vascular loops for blood sampling and dosing in minipigs

Continous blood sampling and intravenous dosing are difficult in pigs, especially minipigs. A skin loop containing the jugular vein or the carotid artery has been used for solving this problem in other species of animals, but it has never beenattempted in the pig. In this study eight such skin loops were made on minipigs, which technically caused only a few problems. Shortening the loop and widening the distance between the two parallel incisions reduced problems of necrosisand improper wound healing. A juvenile pig did not show such problems. However, in all loops excessive formation of fibrotie tissue occluded the vessel after approximately six days. We, therefore, conclude that although the surgical technique ispossible: further modification, e.g, by insertion of a rigid artificial vessel or an in-dwelling catheter, is necessary, before vascular loops can he used as a method for continuous sampling and dosing in minipigs