59 research outputs found
Stellar black holes: cosmic history and feedback at the dawn of the universe
Significant historic cosmic evolution for the formation rate of stellar black
holes is inferred from current theoretical models of the evolution of massive
stars, the multiple observations of compact stellar remnants in the near and
distant universe, and the cosmic chemical evolution. The mean mass of stellar
black holes, the fraction of black holes/neutron stars, and the fraction of
black hole high mass X-ray binaries (BH-HMXBs)/solitary black holes increase
with redshift. The energetic feedback from large populations of BH-HMXBs form
in the first generations of star burst galaxies has been overlooked in most
cosmological models of the reionization epoch of the universe. The powerful
radiation, jets, and winds from BH-HMXBs heat the intergalactic medium over
large volumes of space and keep it ionized until AGN take over. It is concluded
that stellar black holes constrained the properties of the faintest galaxies at
high redshifts. I present here the theoretical and observational grounds for
the historic cosmic evolution of stellar black holes. Detailed calculations on
their cosmic impact are presented elsewhere (Mirabel, Dijkstra, Laurent, Loeb,
Pritchard, 2011).Comment: 9 pages, 1 color figure. Invited talk at the IAU Symp. 275, Jets at
all scales. Held in Buenos Aires on 13-17 September 2010. To be published by
Cambridge University Press. Eds. G. Romero, R. Sunyaev and T. Bellon
The English City Riots of 2011, "Broken Britain" and the retreat into the present
The responses to the English city riots of 2011 bear a remarkable resemblance to those of historical urban disorders in terms of the way in which they are framed by concerns over "moral decline", "social malaise" and a "lack of self-restraint" among certain sections of the population. In this paper we draw on the work of Norbert Elias and take a long-term perspective in exploring historical precedents and parallels relating to urban disorder and anti-social behaviour. We reject the notion of "Broken Britain" and argue that a more "detached" perspective is necessary in order to appreciate that perceived crises of civilisation are ubiquitous to the urban condition. Through this historical analysis, framed by Elias' theory of involvement and detachment, we present three key arguments. Firstly, that a 'retreat into the present' is evident among both policy discourse and social science in responding to contemporary urban disorder, giving rise to ahistorical accounts and the romanticisation of previous eras; secondly, that particular moral panics have always arisen, specifically focused upon young and working class populations and urban disorder; and, thirdly, that previous techniques of governance to control these populations were often far more similar to contemporary mechanisms than many commentaries suggest. We conclude by advocating a long-term, detached perspective in discerning historical precedents and their direct linkages to the present; and in identifying what is particular about today's concerns and responses relating to urban disorder
Sequencing of Culex quinquefasciatus establishes a platform for mosquito comparative genomics
Culex quinquefasciatus (the southern house mosquito) is an important mosquito vector of viruses such as West Nile virus and St. Louis encephalitis virus, as well as of nematodes that cause lymphatic filariasis. C. quinquefasciatus is one species within the Culex pipiens species complex and can be found throughout tropical and temperate climates of the world. The ability of C. quinquefasciatus to take blood meals from birds, livestock, and humans contributes to its ability to vector pathogens between species. Here, we describe the genomic sequence of C. quinquefasciatus: Its repertoire of 18,883 protein-coding genes is 22% larger than that of Aedes aegypti and 52% larger than that of Anopheles gambiae with multiple gene-family expansions, including olfactory and gustatory receptors, salivary gland genes, and genes associated with xenobiotic detoxification
Exome-Derived Adiponectin-Associated Variants Implicate Obesity and Lipid Biology
Circulating levels of adiponectin, an adipocyte-secreted protein associated with cardiovascular and metabolic risk, are highly heritable. To gain insights into the biology that regulates adiponectin levels, we performed an exome array meta-analysis of 265,780 genetic variants in 67,739 individuals of European, Hispanic, African American, and East Asian ancestry. We identified 20 loci associated with adiponectin, including 11 that had been reported previously (p .60) spanning as much as 900 kb. To identify potential genes and mechanisms through which the previously unreported association signals act to affect adiponectin levels, we assessed cross-trait associations, expression quantitative trait loci in subcutaneous adipose, and biological pathways of nearby genes. Eight of the nine loci were also associated (p <1 x 10(-4)) with at least one obesity or lipid trait. Candidate genes include PRKAR2A, PTH1R, and HDAC9, which have been suggested to play roles in adipocyte differentiation or bone marrow adipose tissue. Taken together, these findings provide further insights into the processes that influence circulating adiponectin levels.Peer reviewe
The Provision of Interventional Radiology Services in Europe: CIRSE Recommendations
Interventional Radiology (IR) is an essential part of modern medicine, delivering minimally invasive patient-focused care, which has been proven to be safe and effective in both elective and emergency settings. The aim of this document is to outline the core requirements and standards for the provision of Interventional Radiological services, including training, certification, manpower, and accreditation. The ultimate challenge will be the adoption of these recommendations by different countries and health economies around the world, in turn ensuring equal access to IR treatments for all patients, the appropriate distribution of resources for IR service provision as well as the continued development of safe and high-quality IR services in Europe and beyond. © 2016, Springer Science+Business Media New York and the Cardiovascular and Interventional Radiological Society of Europe (CIRSE)
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