A formal method for identifying distinct states of variability in time-varying sources: SgrA* as an example

Continuously time variable sources are often characterized by their power spectral density and flux distribution. These quantities can undergo dramatic changes over time if the underlying physical processes change. However, some changes can be subtle and not distinguishable using standard statistical approaches. Here, we report a methodology that aims to identify distinct but similar states of time variability. We apply this method to the Galactic supermassive black hole, where 2.2 um flux is observed from a source associated with SgrA*, and where two distinct states have recently been suggested. Our approach is taken from mathematical finance and works with conditional flux density distributions that depend on the previous flux value. The discrete, unobserved (hidden) state variable is modeled as a stochastic process and the transition probabilities are inferred from the flux density time series. Using the most comprehensive data set to date, in which all Keck and a majority of the publicly available VLT data have been merged, we show that SgrA* is sufficiently described by a single intrinsic state. However the observed flux densities exhibit two states: a noise-dominated and a source-dominated one. Our methodology reported here will prove extremely useful to assess the effects of the putative gas cloud G2 that is on its way toward the black hole and might create a new state of variability.Comment: Submitted to ApJ; 33 pages, 4 figures; comments welcom

Alien Registration- Longstaff, James L. (Limestone, Aroostook County)

https://digitalmaine.com/alien_docs/34179/thumbnail.jp

National quality and performance system for Divisions of General Practice: early reflections on a system under development

Governments are increasingly introducing performance management systems to improve the quality and outcomes of health care. Two types of approaches have been described: assurance systems that use summative information for external accountability and internally driven systems that use formative information for continuous quality improvement. Australia recently introduced a National Quality and Performance System (NQPS) for Divisions of General Practice that has the dual purposes of increasing accountability and improving performance. In this article, we ask whether the framework can deliver on its objectives for achieving accountability and fostering performance improvement. We examine the system in terms of four factors identified in a recent systematic review of indicator systems known to improve their use. These are: involving stakeholders in development; having clear objectives; approach to data collection and analysis including using 'soft data' to aid interpretation; and feeding back information. RESULTS: We found that early consultative processes influenced system development. The system promotes the collection of performance information against defined program objectives. Data includes a mix of qualitative and quantitative indicators that are fitted to a conceptual framework that facilitates an approach to performance assessment that could underpin continuous quality improvement at the Division level. Feedback of information to support the development of quality improvement activities has not been fully developed. CONCLUSION: The system currently has elements that, with further development, could support a more continuous quality improvement or assurance based approach. Careful consideration needs to be given to the development of methods for analysis and review of performance indicators, performance assessment and engagement with consumers. The partnership arrangement that supported early development could be expected to serve as an important vehicle for further development

Inhibition of Malignant Cell Invasion in vitro by a Proteinase Inhibitor

The inhibitory effect of the protease inhibitor aprotinin (Trasylol) on the invasion of mouse kidney explants by polyoma virus transformed BHK21 cells was investigated using a mixed cell/organ culture technique. The extent of invasion was monitored by following the changes in LDH isoenzyme pattern in the explants and by histological assessment. The kidney explants containing aprotinin were found to maintain a normal kidney LDH pattern and to suffer considerably less invasion than the explants not containing the drug. These results support the idea that proteolytic enzymes are associated with invasion and that inhibitors of protease activity could possibly be useful in the management of clinical cancer

Note and Comment

Constitutionality of the LA Follette Amendment to the Internal Revenue Law of 1921 - The United States Senate on November 5, 1921, inserted in the Revenue Act, then before the Senate, a provision that taxpayers in their income tax returns must specify what state and municipal bonds they hold, or else be subject to a penalty of five per cent. That provision was dropped out in conference, but it will come up again, and it is well to look at its constitutionality under the Fourth Amendment to the Constitution prohibiting unreasonable searches