National and Regional Estimates of the Prevalence of Opiate and/or Crack Cocaine use 2008-09: A summary of key findings

<p>This report summarises the results of a follow-up study to a three year project to estimate the prevalence of ‘problem drug use’ (defined as use of opiates and/or crack cocaine) nationally (England only), regionally and locally. The follow-up was carried out two years after the final sweep of the original project, so could therefore be considered as ‘sweep 5’. An overview of the national and regional estimates are presented in this report, as are comparisons with the estimates produced by the third (2006-07) sweep of the study. Estimates for 2007-08 are not available as a study was not commissioned for that year.</p> <p>Information about the number of people who use illicit drugs such as heroin, other opiates or crack cocaine is key to formulating effective policies for tackling drug-related harm as these drugs are associated with the highest levels of harm. It also helps inform service provision at the local level and provides a context in which to understand the population impact of interventions to reduce drug-related harm.</p> <p>Direct enumeration of those engaged in a largely covert activity such as the use of class A drugs is difficult and standard household survey techniques tend to underestimate the extent of such activity. Indirect techniques making use of various data sources offer a more reliable way of calculating prevalence estimates for the use of opiates and/or crack cocaine. The estimates presented in this report are derived using two indirect measurement techniques: the capture-recapture method (CRC ); and the multiple indicator (MIM ) method. These methods are described in detail in Hay et al., 2006 and Hay et al., 2007a. Methodological developments throughout the course of the previous three sweeps are discussed elsewhere (Hay et al., 2007b, Hay et al., 2008). The individuals covered by this study were people aged 15 to 64 and resident in each DAT area, and known to be using heroin, methadone, other opiate drugs or crack cocaine.</p&gt

Sulphur-bearing molecules in AGB stars I: The occurrence of hydrogen sulfide

Through a survey of (sub-)millimetre emission lines of various sulphur-bearing molecules, we aim to determine which molecules are the primary carriers of sulphur in different types of AGB stars. In this paper, the first in a series, we investigate the occurrence of H$_2$S in AGB circumstellar envelopes and determine its abundance, where possible. We have surveyed 20 AGB stars with a range of mass-loss rates and of different chemical types using the APEX telescope to search for rotational transition lines of five key sulphur-bearing molecules: CS, SiS, SO, SO$_2$ and H$_2$S. Here we present our results for H$_2$S, including detections, non-detections and detailed radiative transfer modelling of the detected lines. We compare results based on different descriptions of the molecular excitation of H$_2$S and different abundance distributions, including those derived from chemical modelling results. We detected H$_2$S towards five AGB stars, all of which have high mass-loss rates of $\dot{M}\geq 5\times 10^{-6}M_\odot$ yr$^{-1}$ and are oxygen-rich. H$_2$S was not detected towards the carbon or S-type stars that fall in a similar mass-loss range. For the stars in our sample with detections, we find peak o-H$_2$S abundances relative to H$_2$ between $4\times 10^{-7}$ and $2.5\times 10^{-5}$. Overall, we conclude that H$_2$S can play a significant role in oxygen-rich AGB stars with higher mass-loss rates, but is unlikely to play a key role in stars of other chemical types or the lower mass-loss rate oxygen-rich stars. For two sources, V1300 Aql and GX Mon, H$_2$S is most likely the dominant sulphur-bearing molecule in the circumstellar envelope.Comment: 14 pages, 7 figures, accepted in A&

Parameter inference in mechanistic models of cellular regulation and signalling pathways using gradient matching

A challenging problem in systems biology is parameter inference in mechanistic models of signalling pathways. In the present article, we investigate an approach based on gradient matching and nonparametric Bayesian modelling with Gaussian processes. We evaluate the method on two biological systems, related to the regulation of PIF4/5 in Arabidopsis thaliana, and the JAK/STAT signal transduction pathway

Novel aspects of the activity and function of xanthine oxidase

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN032855 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Atomic Diagnostics of X-ray Irradiated Protoplanetary Disks

We study atomic line diagnostics of the inner regions of protoplanetary disks with our model of X-ray irradiated disk atmospheres which was previously used to predict observable levels of the NeII and NeIII fine-structure transitions at 12.81 and 15.55mum. We extend the X-ray ionization theory to sulfur and calculate the fraction of sulfur in S, S+, S2+ and sulfur molecules. For the D'Alessio generic T Tauri star disk, we find that the SI fine-structure line at 25.55mum is below the detection level of the Spitzer Infrared Spectrometer (IRS), in large part due to X-ray ionization of atomic S at the top of the atmosphere and to its incorporation into molecules close to the mid-plane. We predict that observable fluxes of the SII 6718/6732AA forbidden transitions are produced in the upper atmosphere at somewhat shallower depths and smaller radii than the neon fine-structure lines. This and other forbidden line transitions, such as the OI 6300/6363AA and the CI 9826/9852AA lines, serve as complementary diagnostics of X-ray irradiated disk atmospheres. We have also analyzed the potential role of the low-excitation fine-structure lines of CI, CII, and OI, which should be observable by SOFIA and Herschel.Comment: Accepted by Ap

The distribution of H13CN in the circumstellar envelope around IRC+10216

H13CN J=8-7 sub-millimetre line emission produced in the circumstellar envelope around the extreme carbon star IRC+10216 has been imaged at sub-arcsecond angular resolution using the SMA. Supplemented by a detailed excitation analysis the average fractional abundance of H13CN in the inner wind (< 5E15 cm) is estimated to be about 4E-7, translating into a total HCN fractional abundance of 2E-5 using the isotopic ratio 12C/13C=50. Multi-transitional single-dish observations further requires the H13CN fractional abundance to remain more or less constant in the envelope out to a radius of about 4E16 cm, where the HCN molecules are effectively destroyed, most probably, by photodissociation. The large amount of HCN present in the inner wind provides effective line cooling that can dominate over that generated from CO line emission. It is also shown that great care needs to be taken in the radiative transfer modelling where non-local, and non-LTE, effects are important and where the radiation field from thermal dust grains plays a major role in exciting the HCN molecules. The amount of HCN present in the circumstellar envelope around IRC+10216 is consistent with predicted photospheric values based on equilibrium chemical models and indicates that any non-equilibrium chemistry occurring in the extended pulsating atmosphere has no drastic net effect on the fractional abundance of HCN molecules that enters the outer envelope. It further suggests that few HCN molecules are incorporated into dust grains.Comment: Accepted for publication in ApJ. 20 pages, 7 figure

Atlas.txt : Exploring Lingusitic Grounding Techniques for Communicating Spatial Information to Blind Users

Peer reviewedPostprin