A New Method of Current Switching for Linear Wide-Range Measurement Systems

This new and general method here called overflow current switching allows a fast, continuous, and smooth transition between scales in wide-range current measurement systems, like electrometers. This is achieved, using a hydraulic analogy, by diverting only the overflow current, such that no slow element is forced to change its state during the switching. As a result, this approach practically eliminates the long dead time in low-current (picoamperes) switching. Similar to a logarithmic scale, a composition of n adjacent linear scales, like a segmented ruler, measures the current. The use of a linear wide-range system based on this technique assures fast and continuous measurement in the entire range, without blind regions during transitions and still holding suitable accuracy for many applications. A full mathematical development of the method is given. Several computer realistic simulations demonstrated the viability of the technique.

New constraints on H-0 and Omega(m) from SZE/X-ray data and baryon acoustic oscillations

The Hubble constant, H-0, sets the scale of the size and age of the Universe and its determination from independent methods is still worthwhile to be investigated. In this article, by using the Sunyaev-Zeldovich effect and X-ray surface brightness data from 38 galaxy clusters observed by Bonamente et al. (Astrophys J 647:25, 2006), we obtain a new estimate of H-0 in the context of a flat Lambda CDM model. There is a degeneracy on the mass density parameter (Omega(m)) which is broken by applying a joint analysis involving the baryon acoustic oscillations (BAO) as given by Sloan Digital Sky Survey. This happens because the BAO signature does not depend on H-0. Our basic finding is that a joint analysis involving these tests yield H-0 = 76.5(-3.33)(+3.35) km/s/mpc and Omega(m) = 0.27(-0.02)(+0.03). Since the hypothesis of spherical geometry assumed by Bonamente et al. is questionable, we have also compared the above results to a recent work where a sample of galaxy clusters described by an elliptical profile was used in analysis.

Cardiovascular risk factors in patients with first-episode psychosis in Sao Paulo, Brazil

Objective: The objective was to evaluate the cardiovascular profile of first-episode psychosis patients in Sao Paulo, Brazil, an issue that has not been sufficiently explored in low-/middle-income countries. Method: A cross-sectional study was performed 1 to 3 years after an initial, larger survey that assessed first-episode psychosis in sao Paulo. We evaluated cardiovascular risk factors and lifestyle habits using standard clinical examination and laboratory evaluation. Results: Of 151 contacted patients, 82 agreed to participate (mean age=35 years; 54% female). The following diagnoses were found: 20.7% were obese, 29.3% had hypertension, 39.0% had dyslipidemia, 19.5% had metabolic syndrome, and 1.2% had a >20% 10-year risk of coronary heart disease based on Framingham score. Also, 72% were sedentary, 25.6% were current smokers, and 7.3% reported a heavy alcohol intake. Conclusion: Compared to other samples, ours presented a distinct profile of higher rates of hypertension and diabetes (possibly due to dietary habits) and lower rates of smoking and alcohol intake (possibly due to higher dependence on social support). Indirect comparison vs. healthy, age-matched Brazilians revealed that our sample had higher frequencies of hypertension, diabetes and metabolic syndrome. Therefore, we confirmed a high cardiovascular risk in first-episode psychosis in Brazil. Transcultural studies are needed to investigate to which extent lifestyle contributes to such increased risk. (C) 2012 Elsevier Inc. All rights reserved.

Consistency of the mass variation formula for black holes accreting cosmological fluids

We address the spherical accretion of generic fluids onto black holes. We show that, if the black hole metric satisfies certain conditions, in the presence of a test fluid it is possible to derive a fully relativistic prescription for the black hole mass variation. Although the resulting equation may seem obvious due to a form of it appearing as a step in the derivation of the Schwarzschild metric, this geometrical argument is necessary to fix the added degree of freedom one gets for allowing the mass to vary with time. This result has applications on cosmological accretion models and provides a derivation from first principles to serve as a basis to the accretion equations already in use in the literature.