Thermalization and the chromo-Weibel instability

Despite the apparent success of ideal hydrodynamics in describing the elliptic flow data which have been produced at Brookhaven National Lab's Relativistic Heavy Ion Collider, one lingering question remains: is the use of ideal hydrodynamics at times t < 1 fm/c justified? In order to justify its use a method for rapidly producing isotropic thermal matter at RHIC energies is required. One of the chief obstacles to early isotropization/thermalization is the rapid longitudinal expansion of the matter during the earliest times after the initial nuclear impact. As a result of this expansion the parton distribution functions become locally anisotropic in momentum space. In contrast to locally isotropic plasmas anisotropic plasmas have a spectrum of soft unstable modes which are characterized by exponential growth of transverse chromo-magnetic/-electric fields at short times. This instability is the QCD analogue of the Weibel instability of QED. Parametrically the chromo-Weibel instability provides the fastest method for generation of soft background fields and dominates the short-time dynamics of the system.Comment: 8 pages, 4 figures, Invited plenary talk given at the 19th International Conference on Ultrarelativistic Nucleus-Nucleus Collisions: Quark Matter 2006 (QM 2006), Shanghai, China, 14-20 Nov 200

Psychosis in Azheimer\u27s Disease

Much of the basic science literature on Alzheimer\u27s Disease (AD) reflects ongoing research into pathophysiology and neuropathology. Yet, despite reports of the association between psychotic symptoms and Alzheimer\u27s disease, relatively little is known about why such symptoms develop in certain patients and not in others. Neuroimaging and genetic studies may provide greater understanding of this association and allow clinicians and researchers to prevent, predict and treat the onset of psychotic symptoms in the future. This paper will review the current literature on the topic of psychosis in Alzheimer\u27s disease and focus on current recommendations for interventions by clinicians and caregivers

Mobile Anesthesia Applications as Point-of-Care Tools for CRNAs in Clinical Practice

Background: The practice of anesthesia requires knowledge of procedures, patient conditions, comorbidities, and medications, as well as the ability to continually assess and respond to the patient’s status. The use of mobile anesthesia applications (apps) has become increasingly common among Certified Registered Nurse Anesthetists (CRNAs) to provide immediate access to current information regarding anesthesia administration and to support optimal patient care.The purpose of this study was to assess the use of mobile anesthesia apps used by CRNAs as point-of-care (POC) tools in their anesthesia practice.Methodology: We report data collected from a survey designed to sample CRNAs who have been in practice for three years or less (“recent” graduates) and who utilize mobile anesthesia apps. The survey was offered to members of a Facebook group called CRNAs and SRNAs.Results: A total of 160 CRNAs in practice three years or less completed the survey and reported the ways they currently use a mobile anesthesia app. In this report we quantify the various ways such apps are used and conclude that mobile apps are widely used among student and/or recent graduate CRNAs as point-of-care tools and who believe they improve the safety and efficacy of their anesthesia practice.Conclusions: The benefits to practice that users report should be encouraging to the developers of mobile health care apps and a motivating factor for more practitioners to utilize them

Bayesian Analysis of the Stochastic Conditional Duration Model

A Bayesian Markov Chain Monte Carlo methodology is developed for estimating the stochastic conditional duration model. The conditional mean of durations between trades is modelled as a latent stochastic process, with the conditional distribution of durations having positive support. The sampling scheme employed is a hybrid of the Gibbs and Metropolis Hastings algorithms, with the latent vector sampled in blocks. The suggested approach is shown to be preferable to the quasi-maximum likelihood approach, and its mixing speed faster than that of an alternative single-move algorithm. The methodology is illustrated with an application to Australian intraday stock market data.Transaction data, Latent factor model, Non-Gaussian state space model, Kalman filter and simulation smoother.

The quest for hot gas in the halo of NGC 1511

XMM-Newton observations of the starburst galaxy NGC 1511 reveal the presence of a previously unknown extended hot gaseous phase of its ISM, which partly extends out of the disk plane. The emission distribution is asymmetric, being brightest in the eastern half of the galaxy, where also radio continuum observations suggest the highest level of star formation. Spectral analysis of the integral 0.2-12 keV X-ray emission from NGC 1511 indicates a complex emission composition. A model comprising a power law plus thermal plasma component, both absorbed by foreground gas, cannot explain all details of the observed spectrum, requiring a third spectral component to be added. This component can be a second thermal plasma, but other spectral models can be fitted as well. Its X-ray properties characterize NGC 1511 as a starburst galaxy. The X-ray-to-infrared luminosity ratio is consistent with this result. Together with the X-ray data, XMM-Newton obtained UV images of NGC 1511, tracing massive stars heating the ambient gas, which is then seen in H\alpha emission. UV, H\alpha and near-infrared imagery suggest that NGC 1511 is disturbed, most likely by its two small companions, NGC 1511a and NGC 1511b.Comment: 7 pages, 7 figures, accepted for publication in A&