Solutions to the relativistic precession model

The relativistic precession model (RPM) can be used to obtain a precise measurement of the mass and spin of a black hole when the appropriate set of quasi periodic oscillations is detected in the power-density spectrum of an accreting black hole. However, in previous studies the solution of the RPM equations could be obtained only through numerical methods at a price of an intensive computational effort. Here we demonstrate that the RPM system of equations can be solved analytically, drastically reducing the computational load, now limited to the Monte-Carlo simulation necessary to estimate the uncertainties. The analytical method not only provides an easy solution to the RPM system when three oscillations are detected, but in all the cases where the detection of two simultaneous oscillations is coupled with an independent mass measurement. We also present a computationally inexpensive method to place limits on the black hole mass and spin when only two oscillations are observed.Comment: Accepted to MNRAS; 8 pages, 3 figure

Editorial: Feminism, women’s movements and women in movement

Introduction to Special Issue that engages with the increasingly important, separate yet interrelated themes of feminism, women’s movements and women in movement in the context of global neoliberalism

Black-hole binaries: life begins at 40 keV

In the study of black-hole transients, an important problem that still needs to be answered is how the high-energy part of the spectrum evolves from the low-hard to the high-soft state, given that they have very different properties. Recent results obtained with RXTE and INTEGRAL have given inconsistent results. With RXTE, we have found that the high-energy cutoff in GX 339-4 during the transition first decreases (during the low-hard state), then increases again across the Hard-Intermediate state, to become unmeasurable in the soft states (possibly because of statistical limitations). We show Simbol-X will be able to determine the spectral shape with superb accuracy. As the high-energy part of the spectrum is relatively less known than the one below 20 keV, Simbol-X will provide important results that will help out understanding of the extreme physical conditions in the vicinity of a stellar-mass black hole.Comment: Proc. "Simbol-X: Focusing on the Hard X-Ray Universe", Paris, 2-5 Dec. 2008, ed. J. Rodriguez and P. Ferrando; 4 pages, 3 figure

Feminism, women’s movements and women in movement

Non peer reviewedPublisher PD

On the modulation of low frequency Quasi-Periodic Oscillations in black-hole transients

We studied the properties of the low-frequency quasi-periodic oscillations detected in a sample of six black hole candidates (XTE J1550-564, H 1743-322, XTE J1859+226, 4U 1630-47,GX 339-4, XTE J1650-500) observed by the Rossi XTE satellite. We analyzed the relation between the full width half maximum and the frequency of all the narrow peaks detected in power density spectra where a type-C QPO is observed. Our goal was to understand the nature of the modulation of the signal by comparing the properties of different harmonic peaks in the power density spectrum. We find that for the sources in our sample the width of the fundamental and of the first harmonic are compatible with a frequency modulation, while that of the sub-harmonic is independent of frequency, possibly indicating the presence of an additional modulation in amplitude. We compare our results with those obtained earlier from GRS 1915+105 and XTE J1550-564.Comment: 8 pages, 3 figures, accepted for publication in Monthly Notices of the Royal Astronomical Society Main Journa

Variability in Low Mass X-ray binaries from milliseconds to years

MISSIN

Interactions between firms and universities in an immature system of innovation: a survey of industrial R&D-performers firms in Minas Gerais, Brazil

This paper presents preliminary results from a survey of R&D-performer industrial firms located in the state of Minas Gerais, Brazil. The inspiration for this research comes from the Yale Survey (Klevorick et all, 1995) and from the Carnegie Mellon Survey (Cohen et all, 2002), for these Surveys are groundwork for the study of interactions between universities and firms. The objective of this Minas Gerais Survey (MG Survey, henceforth) is the investigation of specific characteristics of the interaction between universities and firms in an 'immature national system of innovation'. The first section summarizes the theoretical questions putted forward by this investigation, specially the role of universities in immature NSIs. The second section investigates the Brazilian NSI using data from the IBGE’s PINTEC, focusing the R&D performer firms in Brazil and the importance of universities and public research institutes as source of knowledge for industrial innovation. This second section presents data that highlight the position of Minas Gerais in the Brazilian NSI and helps to define the MG Survey research universe. The third section summarizes the issues involved in the adaptation of the Yale and the Carnegie Mellon questionnaires to the Brazilian reality and in the identification of the R&D-performer firms in Minas Gerais. The fourth section presents the MG Survey results. The fifth section concludes the paper.systems of innovations, interactions between science and technologies

Combination of metabolomic and proteomic analysis revealed different features among Lactobacillus delbrueckii subspecies bulgaricus and lactis strains while in vivo testing in the model organism Caenorhabditis elegans highlighted probiotic properties

Lactobacillus delbrueckii represents a technologically relevant member of lactic acid bacteria, since the two subspecies bulgaricus and lactis are widely associated with fermented dairy products. In the present work, we report the characterization of two commercial strains belonging to L. delbrueckii subspecies bulgaricus, lactis and a novel strain previously isolated from a traditional fermented fresh cheese. A phenomic approach was performed by combining metabolomic and proteomic analysis of the three strains, which were subsequently supplemented as food source to the model organism Caenorhabditis elegans, with the final aim to evaluate their possible probiotic effects. Restriction analysis of 16S ribosomal DNA revealed that the novel foodborne strain belonged to L. delbrueckii subspecies lactis. Proteomic and metabolomic approaches showed differences in folate, aminoacid and sugar metabolic pathways among the three strains. Moreover, evaluation of C. elegans lifespan, larval development, brood size, and bacterial colonization capacity demonstrated that L. delbrueckii subsp. bulgaricus diet exerted beneficial effects on nematodes. On the other hand, both L. delbrueckii subsp. lactis strains affected lifespan and larval development. We have characterized three strains belonging to L. delbrueckii subspecies bulgaricus and lactis highlighting their divergent origin. In particular, the two closely related isolates L. delbrueckii subspecies lactis display different galactose metabolic capabilities. Moreover, the L. delbrueckii subspecies bulgaricus strain demonstrated potential probiotic features. Combination of omic platforms coupled with in vivo screening in the simple model organism C. elegans is a powerful tool to characterize industrially relevant bacterial isolates