Does Low Frequency X-ray QPO Behavior in GRS 1915+105 Influence Subsequent X-ray and Infrared Evolution?

Using observations with the Rossi X-ray Timing Explorer, we examine the behavior of 2-10 Hz quasi-periodic oscillations (QPOs) during spectrally-hard dips in the x-ray light curve of GRS 1915+105 that are accompanied by infrared flares. Of the twelve light-curves examined, nine are beta-class and three are alpha-class following the scheme of Belloni et al. (2000). In most cases, the QPO frequency is most strongly correlated to the power law flux, which partially contradicts some earlier claims that the strongest correlation is between QPO frequency and blackbody flux. Seven beta-class curves are highly correlated to blackbody features. In several cases, the QPO evolution appears to decouple from the spectral evolution. We find that beta-class light-curves with strong correlations can be distinguished from those without by their ``trigger spike'' morphology. We also show that the origin and strength of the subsequent infrared flare may be causally linked to the variations in QPO frequency evolution and not solely tied to the onset of soft x-ray flaring behavior. We divide the twelve alpha- and beta-class light-curves into three groups based on the evolution of the QPO, the morphology of the trigger spike, and the infrared flare strength. An apparent crossover case leads us to conclude that these groups are not unique modes but represent part of a continuum of accretion behaviors. We believe the QPO behavior at the initiation of the hard dip can ultimately be used to determine the terminating x-ray behavior, and the following infrared flaring behavior.Comment: 29 pages, 9 figures, to be published in Ap

Assessment of the risk of Hepatitis E virus occurrence in pork carcasses at slaughter in the UK

Hepatitis E virus (HEV) is a RNA virus of the genus Hepevirus. HEV genotype 3 is zoonotic and pigs are the main reservoir. This genotype has been identified in the United Kingdom, in sporadic locally-acquired cases without recent history of foreign travel to endemic countries. The number of HEV-confirmed human cases in the UK has increased significantly, from 124 cases in 2003 to 661 in 2013. Non-travel cases now account for the majority (69%) of cases observed annually in the UK. Our aim was to assess the risk of HEV occurrence in pork carcases at slaughter in the UK. We performed a quantitative exposure assessment using Monte Carlo simulation to estimate the number of carcasses contaminated with HEV produced in a high throughput porcine abattoir during one year. The input data used were: a) true prevalence in British pigs, b) probability of viral shedding in bile and faeces c) number of pig carcases with bile and/or faecal contamination detected during post-mortem inspection. The following assumptions were made when data were unavailable: a) sensitivity and specificity of the RP-PCR diagnostic test; b) meat from viraemic pigs was considered HEV-positive; c) visual faecal and bile contamination only considered since microscopic contamination would not be detected through visual inspection. We estimated through our model that 175,152 (2.4%) of carcases produced in high throughput abattoirs would be infected with HEV in one year period. The number of viraemic pigs slaughtered at the abattoir was the largest driver of the uncertainty in carcass contamination. Variations in this parameter would change the output from 62,982 carcasses up to 306,320. Mitigation strategies at farm level should be explored, as it appears that control at this level would likely result in a higher reduction in HEV contamination in pork meat

Epidemias: un nuevo objeto sociotécnico

This the final version. Available from Universidad autónoma del estado de México via the URL in this recordRecently, epidemics have become an important concern in social sciences. They currently have two important ways of conceptualizing epidemics: a) as a panic object; or b) as a bio-political situation. Nevertheless, these two perspectives disregard that epidemics basically are a way of transforming our daily life. In order to grasp this impact we put forward to conceptualize epidemics as a socio-technical object. Our paper will show this perspective. Analyzing mass media, information from academic journals, such as Science, or from Health Institutions we will explain how epidemics change the main borders of our everyday life. That is, the tension between animal-human, local-global, politics-nature and healthy-pathological. We will argue that after the aforementioned rupture appears a new redefinition of said limits with the following elements: a) medicine appears as the most relevant dimension in that redefinition; b) it is defined a kind of “biological emergency” as the way to understand the aforementioned process of redefinition; and c) a specific body regime is update

The crystal chemistry and reactivity of ternary Na2Fe3Cl8 from the NaCl-FeCl2 system and its potential application as coating layer for cathode in sodium ion batteries

This report explores theoretical and experimental methods to characterize the ternary phases arising from the NaCl + FeCl2 system at both low (150 °C) and high temperatures (550 °C), through milling and evaporation processing techniques. We found that Na2Fe3Cl8 is the only metastable ternary compound produced in either case and only at high temperatures, which is in good qualitative agreement with density functional theory calculations performed with the recent r2SCAN metaGGA functional. The elementary, crystallographic, and grain structure information on Na2Fe3Cl8 collected using a combination of x-ray diffraction, scanning electron microscopy, energy dispersive, and Mössbauer spectroscopy is described and discussed in detail. Na2Fe3Cl8 is determined to have a layered trigonal structure in the R3m space group. Other ternary stable or metastable ternary phases such as Na6FeCl8 and Na2FeCl4 were not observed, which is likely the result of decomposition occurring beyond 400 °C. While the structure of Na2Fe3Cl8 makes it inadequate as a potential cathode in Na-ion batteries, Na2Fe3Cl8 may operate as a suitable coating layer to regulate the passage of ions from electrolytes to active electrode materials without interfacial degradation

La desinstitucionalización y la crisis de las instituciones

.Hablar de instituciones se ha convertido en hablar de crisis de las instituciones. En este sentido, la noción de desinstitucionalización ocupa un lugar relevante en la reflexión institucional. Por este motivo, en este artículo se lleva a cabo una revisión del concepto de institución y de las principales críticas que ha recibido como paso previo al análisis más detallado del fenómeno desinstitucionalizador en la práctica psiquiátrica. Tal análisis lleva a la elaboración de una propuesta alternativa que cuestiona la pertinencia de seguir hablando de instituciones así como de procesos desinstitucionalizadores. Concretamente, se plantea que las especiales características de algunas prácticas psiquiátricas contemporáneas se ajustan mejor a la noción de ex-titución tomada de la obra de Serres

A photometricity and extinction monitor at the Apache Point Observatory

An unsupervised software ``robot'' that automatically and robustly reduces and analyzes CCD observations of photometric standard stars is described. The robot measures extinction coefficients and other photometric parameters in real time and, more carefully, on the next day. It also reduces and analyzes data from an all-sky $10 \mu m$ camera to detect clouds; photometric data taken during cloudy periods are automatically rejected. The robot reports its findings back to observers and data analysts via the World-Wide Web. It can be used to assess photometricity, and to build data on site conditions. The robot's automated and uniform site monitoring represents a minimum standard for any observing site with queue scheduling, a public data archive, or likely participation in any future National Virtual Observatory.Comment: accepted for publication in A