The effect of X-ray dust-scattering on a bright burst from the magnetar 1E 1547.0-5408

A bright burst, followed by an X-ray tail lasting ~10 ks, was detected during an XMM-Newton observation of the magnetar 1E 1547.0-5408 carried out on 2009 February 3. The burst, also observed by SWIFT/BAT, had a spectrum well fit by the sum of two blackbodies with temperatures of ~4 keV and 10 keV and a fluence in the 0.3-150 keV energy range of ~1e-5 erg/cm2. The X-ray tail had a fluence of ~4e-8 erg/cm2. Thanks to the knowledge of the distances and relative optical depths of three dust clouds between us and 1E 1547.0-5408, we show that most of the X-rays in the tail can be explained by dust scattering of the burst emission, except for the first ~20-30 s. We point out that other X-ray tails observed after strong magnetar bursts may contain a non-negligible contribution due to dust scattering.Comment: 8 pages, 2 tables and 10 figures; accepted to publication in MNRA

It Obliges You to Do Things You Normally Wouldn't: Organizing and Consuming Private Life in the Age of Airbnb

In what ways do everyday life and private spaces become productive elements for platform organizations? Referring to a research on Airbnb (a platform-based company and current leader at the global level in the online hospitality industry) recently conducted in a touristic north-eastern Italian province, this paper critically explores to what degree and how Airbnb pervades, changes and controls the Hosts' domestic space and spare time. To do so, first we will concentrate on the elements that regulate the relationship between the user and the platform and on some of the processes and mechanisms implied by the platform architecture. Then, by describing the everyday practices of "house-management" enacted by the Hosts, we will highlight the invisible work involved in 'performing the platform'. From this point of view, it is worth noticing how, although Airbnb does not aim to create a parallel labour market, it produces 'platform workers' anyway, in that it implies the active engagement of its users in concrete activities. Airbnb is thus a perfect case to look at the ways in which platform organizations engage users in forms of production previously unknown, turning private goods and time into productive elements

Pulsed homodyne Gaussian quantum tomography with low detection efficiency

Pulsed homodyne quantum tomography usually requires a high detection efficiency limiting its applicability in quantum optics. Here, it is shown that the presence of low detection efficiency ($<50\%$) does not prevent the tomographic reconstruction of quantum states of light, specifically, of Gaussian type. This result is obtained by applying the so-called "minimax" adaptive reconstruction of the Wigner function to pulsed homodyne detection. In particular, we prove, by both numerical and real experiments, that an effective discrimination of different Gaussian quantum states can be achieved. Our finding paves the way to a more extensive use of quantum tomographic methods, even in physical situations in which high detection efficiency is unattainable

La otra cara de Jano

[La otra cara de Jano. Una mirada crítica sobre el libro y la edición. Buenos Aires: Ampersand, 2015, 353 páginas.

Discovery of spin-up in the X-ray pulsar companion of the hot subdwarf HD 49798

The hot subdwarf HD 49798 has an X-ray emitting compact companion with a spin-period of 13.2 s and a dynamically measured mass of 1.28+/-0.05 M_sun, consistent with either a neutron star or a white dwarf. Using all the available XMM-Newton and Swift observations of this source, we could perform a phase-connected timing analysis extending back to the ROSAT data obtained in 1992. We found that the pulsar is spinning up at a rate of (2.15+/-0.05)x10^{-15} s/s. This result is best interpreted in terms of a neutron star accreting from the wind of its subdwarf companion, although the remarkably steady period derivative over more than 20 years is unusual in wind-accreting neutron stars. The possibility that the compact object is a massive white dwarf accreting through a disk cannot be excluded, but it requires a larger distance and/or properties of the stellar wind of HD 49798 different from those derived from the modelling of its optical/UV spectra.Comment: Accepted for publication in MNRA

Buenos Aires 1920-1940. La emergencia de un centro editorial periférico

Este trabajo analiza las redes intelectuales, políticas, comerciales, estéticas y migrantes que se establecen en el período de emergencia de un campo editorial en Argentina, en el período de entreguerras. Desde la formación de las primeras colecciones de libros baratos de los inmigrantes judíos y españoles (Glusberg, Zamora, Torrendell) hasta la formación de las primeras editoriales modernas a cargo de los editores del exilio español (EMECE, Sudamericana, Losada, Espasa Calpe Argentina) en la década de 1940.This paper analyzes the intellectual, political, commercial, aesthetic and migratory networks that were established during the emergence of an editorial field in Argentina, in the interwar years. From the creation of the first collections of cheap books of Jewish and Spanish immigrants (Glusberg, Zamora, Torrendell) after the Great War, to the foundation of the first modern publishing houses by the editors of the Spanish exile (EMECE, Sudamericana, Losada, Espasa Calpe Argentina) in the 1940s.Fil: Esposito, Fabio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones en Humanidades y Ciencias Sociales. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación. Instituto de Investigaciones en Humanidades y Ciencias Sociales; Argentin

Genetic variants of Y chromosome are associated with a protective lipid profile in black men

Objective— Gender and ethnicity modulate the phenotypic expression of cardiovascular risk factors. In particular, men are at higher risk of developing cardiovascular diseases compared to women, whereas black populations of African origin display reduced mortality from coronary heart disease (CHD) as compared to both whites and South Asians. Because the male-specific region (MSY) of the human Y chromosome is an obvious candidate for gender-related differences in the development of cardiovascular diseases, we aimed to identify genetic variants of MSY influencing cardiovascular risk profile in different ethnic groups. Methods and Results— We genotyped 4 polymorphisms of MSY (HindIII±, rs768983 of TBL1Y, rs3212292 of USP9Y, and rs9341273 of UTY genes) in 579 men of different ethnic groups (blacks, South Asians, and whites) from UK and in 301 whites in Italy. We found that the TBL1YA USP9YA haplotype, present only in blacks in whom it represents the most frequent allelic combinations (AA: n=125; all other combinations: n=45), was associated with lower levels of triglycerides (P=0.025) and higher levels of HDL-cholesterol (P=0.005) as compared to the other haplotypes. Conclusion— The TBL1YA USP9YA haplotype of the Y chromosome, present only in black people of African origin, attributes a favorable lipoprotein pattern, likely to contribute to their reduced susceptibility to coronary heart disease. The study evaluated the association of genetic variants of the male-specific region of the Y chromosome with cardiovascular risk factors in different ethnic groups. The most frequently observed haplotype in black people was associated with a favorable lipoprotein pattern, thus contributing to the lower rate of cardiovascular diseases in blacks

Pro-Resolving FPR2 Agonists Regulate NADPH Oxidase-Dependent Phosphorylation of HSP27, OSR1, and MARCKS and Activation of the Respective Upstream Kinases

Formyl peptide receptor 2 (FPR2) is involved in the pathogenesis of chronic inflammatory diseases, being activated either by pro-resolving or proinflammatory ligands. FPR2-associated signal transduction pathways result in phosphorylation of several proteins and in NADPH oxidase activation. We, herein, investigated molecular mechanisms underlying phosphorylation of heat shock protein 27 (HSP27), oxidative stress responsive kinase 1 (OSR1), and myristolated alanine-rich C-kinase substrate (MARCKS) elicited by the pro-resolving FPR2 agonists WKYMVm and annexin A1 (ANXA1)