Carbonyl sulfide (OCS): Large-scale distributions over North America during INTEX-NA and relationship to CO2

An extensive set of carbonyl sulfide (OCS) observations were made as part of the NASA Intercontinental Chemical Transport Experiment-North America (INTEX-NA) study, flown from 1 July to 14 August 2004 mostly over the eastern United States and Canada. These data show that summertime OCS mixing ratios at low altitude were dominated by surface drawdown and were highly correlated with CO2. Although local plumes were observed on some low-altitude flight legs, anthropogenic OCS sources were small compared to this sink. These INTEX-NA observations were in marked contrast to the early springtime 2001 Transport and Chemical Evolution over the Pacific experiment, which sampled Asian outflow dominated by anthropogenic OCS emissions. To test the gridded OCS fluxes used in past models, the INTEX-NA observations were combined with the sulfur transport Eulerian model (STEM) regional atmospheric chemistry model for a top-down assessment of bottom-up OCS surface fluxes for North America. Initial STEM results suggest that the modeled fluxes underestimate the OCS plant sink by more than 200%. Copyright 2008 by the American Geophysical Union

Electrical properties of InSb quantum wells remotely doped with Si

Two-dimensional electron systems were realized in InSb quantum wells with Al x In 1Ϫx Sb barrier layers ␦-doped with Si. Measured electron mobilities in multiple-quantum-well structures were as high as 41 000 cm 2 /V s at room temperature and 209 000 cm 2 /V s at 77 K. Simple models can be used to explain the observed dependencies of the electron density on the quantum-well-to-dopant distance and on the number of quantum wells. Characterization by atomic force microscopy indicates that layer morphology may be a factor limiting electron mobility

Quantum magneto-optics of graphite family

The optical conductivity of graphene, bilayer graphene, and graphite in quantizing magnetic fields is studied. Both dynamical conductivities, longitudinal and Hall's, are analytically evaluated. The conductivity peaks are explained in terms of electron transitions. We have shown that trigonal warping can be considered within the perturbation theory for strong magnetic fields larger than 1 T and in the semiclassical approach for weak fields when the Fermi energy is much larger than the cyclotron frequency. The main optical transitions obey the selection rule with \Deltan = 1 for the Landau number n, however the \Deltan = 2 transitions due to the trigonal warping are also possible. The Faraday/Kerr rotation and light transmission/reflection in the quantizing magnetic fields are calculated. Parameters of the Slonczewski-Weiss-McClure model are used in the fit taking into account the previous dHvA measurements and correcting some of them for the case of strong magnetic fields.Comment: 28 pages, 12 figures. arXiv admin note: text overlap with arXiv:1106.340

Deconstructing the lesbian, gay, bisexual, transgender victim of sex trafficking: Harm, exceptionality and religion–sexuality tensions

Contrary to widespread belief, sex trafficking also targets lesbian, gay, bisexual, transgender (LGBT) communities. Contemporary social and political constructions of victimhood lie at the heart of regulatory policies on sex trafficking. Led by the US Department of State, knowledge about LGBT victims of trafficking constitutes the newest frontier in the expansion of criminalization measures. These measures represent a crucial shift. From a burgeoning range of preemptive measures enacted to protect an amorphous class of ‘all potential victims’, now policies are heavily premised on the risk posed by traffickers to ‘victims of special interest’. These constructed identities, however, are at odds with established structures. Drawing on a range of literatures, the core task of this article is to confront some of the complexities and tensions surrounding constructions of LGBT trafficking victims. Specifically, the article argues that discourses of ‘exceptional vulnerability’ and the polarized notions of ‘innocence’ and ‘guilt’ inform hierarchies of victimhood. Based on these insights, the article argues for the need to move beyond monolithic understandings of victims, by reframing the politics of harm accordingly

Can rights stop the wrongs? Exploring the connections between framings of sex workers’ rights and sexual and reproductive health

<p>Abstract</p> <p>Background</p> <p>There is growing interest in the ways in which legal and human rights issues related to sex work affect sex workers’ vulnerability to HIV and abuses including human trafficking and sexual exploitation. International agencies, such as UNAIDS, have called for decriminalisation of sex work because the delivery of sexual and reproductive health services is affected by criminalisation and social exclusion as experienced by sex workers. The paper reflects on the connections in various actors’ framings between sex workers sexual and reproductive health and rights (SRHR) and the ways that international law is interpreted in policing and regulatory practices.</p> <p>Methods</p> <p>The literature review that informs this paper was carried out by the authors in the course of their work within the Paulo Longo Research Initiative. The review covered academic and grey literature such as resources generated by sex worker rights activists, UN policy positions and print and online media. The argument in this paper has been developed reflectively through long term involvement with key actors in the field of sex workers’ rights.</p> <p>Results</p> <p>International legislation characterises sex work in various ways which do not always accord with moves toward decriminalisation. Law, policy and regulation at national level and law enforcement vary between settings. The demands of sex worker rights activists do relate to sexual and reproductive health but they place greater emphasis on efforts to remove the structural barriers that limit sex workers’ ability to participate in society on an equal footing with other citizens.</p> <p>Discussion and conclusion</p> <p>There is a tension between those who wish to uphold the rights of sex workers in order to reduce vulnerability to ill-health and those who insist that sex work is itself a violation of rights. This is reflected in contemporary narratives about sex workers’ rights and the ways in which different actors interpret human rights law. The creation of regulatory frameworks around sex work that support health, safety and freedom from abuse requires a better understanding of the broad scope of laws, policies and enforcement practices in different cultural contexts and economic settings, alongside reviews of UN policies and human rights conventions.</p

Magnetic resonance imaging after most common form of concussion

<p>Abstract</p> <p>Background</p> <p>Until now there is a lack of carefully controlled studies with conventional MR imaging performed exclusively in concussion with short lasting loss of consciousness (LOC).</p> <p>Methods</p> <p>A MR investigation was performed within 24 hours and after 3 months in 20 patients who had suffered a concussion with a verified loss of consciousness of maximally 5 minutes. As a control group, 20 age- and gender matched patients with minor orthopaedic injuries had a MR investigation using the same protocol.</p> <p>Results</p> <p>In a concussion population with an average LOC duration of 1. 4 minutes no case with unequivocal intracranial traumatic pathology was detected.</p> <p>Conclusion</p> <p>An ordinary concussion with short lasting LOC does not or only seldom result in a degree of diffuse axonal injury (DAI) that is visualized by conventional MR with field strength of 1.0 Tesla (T). Analysis of earlier MR studies in concussion using field strength of 1.5 T as well as of studies with diffusion tensor MR imaging (MR DTI) reveal methodological shortcomings, in particular use of inadequate control groups. There is, therefore, a need for carefully controlled studies using MR of higher field strength and/or studies with MR DTI exclusively in common concussion with LOC of maximally 5 minutes.</p