A continuous set of echelle spectra of TW Hya, taken with the MIKE spectrograph on the Magellan2/Clay telescope at Las Campanas Observatory in April 2006 reveals systematic variations in the flux, ...velocity, and profile of the H-alpha emission line which appear to be consistent with the photometric period of 2.8 days. Absorption features recur at high outflow velocities in the wind. This behavior suggests that: (a) accretion is not uniformly distributed over the stellar hemisphere in view; (b) stable structures are present in the chromosphere, most likely due to the stellar magnetic field configuration. Semi-empirical models of the atmosphere are constructed to reproduce line profiles of H-alpha and He I, 10830A and to define the wind structure. These preliminary calculations suggest the mass loss rate is variable and comparable to H-alpha mass accretion rates in the literature, requiring a very efficient mechanism if the wind is powered only by accretion.
The toxicologic problems of today frequently require long-term, multidisciplinary experimentation involving large numbers of animals. In order to provide the extensive safety evaluation necessary to ...produce data that can be reasonably extrapolated to humans, automated research support systems have transcended the position of useful tools and have become an integral part of the total design of experimental protocols. For an automated information system to fully represent the reality of the experiment, it must be able to assure integrity, as well as provide for the storage, calculation, and retrieval of data values of the quality and quantity necessary for fulfilling protocol requirements. Guarantees against error and loss of data, in addition to flexibility and easy access, must be an inherent part of the system if the acceptance and confidence of the investigator are to be obtained. This paper discusses the criteria, philosophies, and benefits of integrated data systems that ensure integrity of toxicologic research support.
