Dynamical Backreaction in Robertson-Walker Spacetime

The treatment of a quantized field in a curved spacetime requires the study of backreaction of the field on the spacetime via the semiclassical Einstein equation. We consider a free scalar field in spatially flat Robertson-Walker space time. We require the state of the field to allow for a renormalized semiclassical stress tensor. We calculate the sigularities of the stress tensor restricted to equal times in agreement with the usual renormalization prescription for Hadamard states to perform an explicit renormalization. The dynamical system for the Robertson Walker scale parameter $a(t)$ coupled to the scalar field is finally derived for the case of conformal and also general coupling.Comment: Obtained equation of motion for non-conformal coupling, not just counter terms as in previous version. Typos fixed, renormalization term proportional to R adde

The Cape Triage Score - a triage system for South Africa

The Cape Triage Score (CTS) has been derived by the Cape Triage Group (CTG) for use in emergency units throughout South Africa. It can also be used in the pre-hospital setting, although it is not designed for mass casualty situations. The CTS comprises a physiologically based scoring system and a list of discriminators, designed to triage patients into one of five priority groups for medical attention. Three versions have been developed, for adults, children and infants. As part of the ongoing assessment process the CTG would value feedback from the readers of this Journal

Changes in specific metabolic pathways are essential steps in the early apoptotic process in the liver

the immunosuppressant Cyclosporine A (CsA), we used multinuclear NMR spectroscopy and molecular studies to characterize metabolic pathways in mice liver during anti-Fas-induced apoptosis. An upregulation of specific metabolic pathways of glucose was the earliest indicator of the effect of Fas on the liver. CsA prevented apoptosis and energy failure at late stages, while the reversal of Fas-induced metabolic upregulation at early stages preceded the protective effect of EGF on programmed cell death. These phenomena provide useful hints for the understanding of early mechanisms controlling apoptotic cell death

Recovery of phenolic compouns by solid-state fermentation from grape pomace and wheat bran.

The grape pomace and wheat bran is rich in bioactive compounds that may be conjugated to the plant cell wall, making it difficult to recover. The objective of this study was to produce an enzymatic complex concomitant to the release of phenolics from grape pomace and wheat bran, by solid-state fermentation (SSF), using the mutant strain Aspergillus niger 3T5B8. Both substrates showed potential for the production of hydrolytic enzymes, mainly for xylanase and ?-glucosidase enzymes with grape pomace and wheat bran, respectively. In addition, SSF showed a more than 50% increase in the phenolic release of the substrates.SINAFERM; SHEB. 3 a 6 de setembro. Seção Trabalhos. Ref. 56515

Beam Test of BTeV Pixel Detectors

The silicon pixel vertex detector is one of the key elements of the BTeV spectrometer. Detector prototypes were tested in a beam at Fermilab. We report here on the measured spatial resolution as a function of the incident angles for different sensor-readout electronics combinations. We compare the results with predictions from our Monte Carlo simulation.Comment: 7 pages, 5 figures, Invited talk given by J.C. Wang at "Vertex 2000, 9th International Workshop on Vertex Detectors", Michigan, Sept 10-15, 2000. To be published in NIM

Flexible and reusable parylene C mask technology for applications in cascade impactor air quality monitoring systems

The development of traceable new methodologies to quantify elemental air pollutants in particulate matter (PM) supports modernization of methods used in air quality monitoring networks in Europe. In the framework of the EURAMET EMPIR AEROMET II project, the combination of cascade impactor aerosol sampling and total reflection X-ray fluorescence elemental spectroscopy (TXRF) was investigated. This technique requires a traceable calibration based on reference samples. This paper describes a new, simple and effective method to produce such reference samples using flexible, reusable, and low-cost parylene C shadow masks, fabricated by photolithographic steps. These shadow masks can be used to produce reference samples that mimic the Dekati cascade impactor's deposition patterns by applying as-prepared micro stencils to 30 mm acrylic substrates and evaporating a reference material (Ti) in arrangements of thin circular dots. The highly flexible direct patterning of acrylic discs with reference material, otherwise impossible with conventional photolithography, allows multiple reusing of the same micro stencils. The aspect ratios of the dots could be repeated with an error less than 4%. A first set of standard reference samples for the 13 stages of the Dekati cascade impactor was produced and preliminary TXRF measurements of the deposited Ti masses were performed. The centricity of the deposition patterns turned out to be an important parameter for the quality of the TXRF results. The parylene mask technology for the production of reference samples turns out to be a promising new approach for the traceable calibration of TXRF spectrometers for the quantification of element concentrations in environmental aerosol samples but, due to its great versatility, it could be used for several other micropatterning applications on conventional and unconventional substrates