807 research outputs found

    Women drug users in North Cumbria: what are the influences upon their problem drug use?

    Get PDF
    The predominant impression of women's problem drug use has been that they are encouraged or oppressed into addiction by male counterparts, and a stereotype has emerged of passive companions. More recently this has been challenged by research which has proposed that women may be active players in the decision to try illegal drugs, and that they may even use substances as an articulation of their emancipation. Most sociological research has tended to focus on male drug users who remain the majority population, but there is increasing evidence that gendered patterns of drug use are converging. The overarching aim of this study was to provide a descriptive account of influences on women's problem drug use in North Cumbria, and to contribute to knowledge about their initiation into heroin use, as well as the pattern and progression of developing drug dependence. North Cumbria is a relatively isolated area and encompasses more than two thirds of the second most sparsely populated county in England. Cumbria contains some of the most spectacular countryside, juxtaposed with areas of multiple disadvantage, particularly along the coastal fringe. Despite its relatively remote location. North Cumbria experiences the effects of problem drug use, with heroin often identified as the drug of choice: recent data confirm that this is particularly evident within its more disadvantaged communities. Qualitative methods were selected for this study because of its exploratory nature and intention to account for the influences on local women's drug use, which comprised the research question. It has previously been found that women drug users tend to be 'hard to reach', and there were significant difficulties experienced in contacting participants, apparently because many women fear identification as addicts, particularly if they are mothers. Interviewees were therefore mainly contacted through sponsors in health and social care agencies in both the statutory and voluntary sector. Semi-structured interviews were carried out with thirty women drug users, over a period of two years, using a prepared topic guide. This guide facilitated the setting out of the women's experiences and therefore broad topics of interest, derived from a review of the literature, were selected to allow the inductive process to develop. Women were encouraged to tell the story of their drug use, often describing specific instances of using heroin within social settings, and they put forward opinions about any influences on their behaviour. Interviewees were also willing to share ideas for improvements in services for women drug users, which were derived from their own lived experience. Themes and concepts were accounted for by describing any variations between women's experiences, and sampling ceased when 'theoretical saturation' was reached because nothing new continued to emerge (Glaser & Strauss, 1957). Interviewees' responses underlined the heterogeneity of women drug users and their experiences, but consistent themes were identified and analysed. The key findings from this study have been identified as the need to acknowledge: interviewees' declared agency in the decision to use heroin; their intention to seek pleasure from the heroin-using experience; their claims that certain predisposing factors might have made them susceptible to initiation; and their belief that the introduction of a peer-mentor intervention in North Cumbria could benefit other women drug users. In conclusion, this study has expanded the argument which has queried previous castings of women addicts as merely compliant in their involvement in problem drug use. Indeed, it seems that it is erroneous to view women drug users as mere victims of the drug culture, since interviewees denied coercion and often said that they had chosen to use heroin from curiosity, or to seek new experiences. The women's assertion that certain predisposing factors might have made them susceptible to problem drug use, and that these issues had sometimes remained unresolved, implies that gender-sensitivity in assessments is important, recognizing difference but avoiding stereotypical gender assumptions. Finally, many interviewees believed that a peer mentor support project could influence and promote recovery from addiction in North Cumbria, and it is both imperative and pragmatic that women drug users themselves are involved in the shaping of their local services

    Optical Spectra of SNR Candidates in NGC 300

    Full text link
    We present moderate-resolution (<5A) long-slit optical spectra of 51 nebular objects in the nearby Sculptor Group galaxy NGC 300 obtained with the 2.3 meter Advanced Technology Telescope at Siding Spring Observatory, Australia. Adopting the criterion of [SII]/Ha>=0.4 to confirm supernova remnants (SNRs) from optical spectra, we find that of 28 objects previously proposed as SNRs from optical observations, 22 meet this criterion with six showing [SII]/Ha of less than 0.4. Of 27 objects suggested as SNRs from radio data, four are associated with the 28 previously proposed SNRs. Of these four, three (included in the 22 above) meet the criterion. In all, 22 of the 51 nebular objects meet the [SII]/Ha criterion as SNRs while the nature of the remaining 29 objects remains undetermined by these observations.Comment: Accepted for publication in Astrophysics & Space Scienc

    A census of fishes and everything they eat: how the Census of Marine Life advanced fisheries science

    Get PDF
    The Census of Marine Life was a 10-year, international research effort to explore poorly known ocean habitats and conduct large-scale experimentation with new technology. The goal of Census 2010 in its mission statement was to describe what did live in the oceans, what does live in the oceans, and what will live in the ocean. Many of the findings and techniques from census research may prove valuable in making a transition, which many governments have publicly endorsed, from single-species fisheries management to more holistic ecosystem management. Census researchers sampled continental margins, mid-Atlantic ridges, ocean floor vents and seeps, and abyssal plains and polar seas and organized massive amounts of past and new information in a public online database called the Ocean Biogeographic Information System (www.iobis.org). The census described and categorized seamount biology worldwide for its vulnerability to fishing, advanced large-scale animal tracking with acoustic arrays and satellite archival tags, and accelerated species identification, including nearshore, coral reef, and zooplankton sampling using genetic barcoding and pyrotag sequencing for microbes and helped to launch the exciting new field of marine environmental history. Above all, the census showed the value of investing in large-scale, collaborative projects and sharing results publicly

    The use of an e-learning constructivist solution in workplace learning

    Get PDF
    We wished to investigate whether an e-learning approach which uses constructivist principles can be successfully applied to train employees in a highly specialised skill thought to require expert individuals and extensive prolonged training. The approach involved the development of an e-learning package which included simulations and interactivity, then experimental testing in a case study workplace environment with the collection of both quantitative and qualitative data to assess the effectiveness of the package. Our study shows that this e-learning strategy improved the skills of the inexperienced operator significantly. We therefore propose that such programmes could be used as a work based training aid and used as a model system for the training of employees in complex skilled tasks in the workplace. This research demonstrates that the e-learning can be applied outside the traditional learning environment to train unskilled employees to undertake complex practical tasks which traditionally would involve prohibitively expensive instruction. This work also illustrates that simulations and interactivity are powerful tools in the design of successful e-learning packages in preparing learners for real world practical situations. Finally this study shows that workplace learners can be better served by elearning environments rather than conventional training as they allow asynchronous learning and private study which are valued by employees who have other demands on their time and are more comfortable receiving tuition privately Relevance to industry: E-learning using constructivist principles, and incorporating simulations and interactivity can be used successfully in the training of highly specialised and skilled tasks required in the modern workplace

    Structural effects in UO2 thin films irradiated with U ions

    Get PDF
    This work presents the results of a detailed structural characterisation of irradiated and unirradiated single crystal thin films of UO2. Thin films of UO2 were produced by reactive magnetron sputtering onto (0 0 1), (1 1 0) and (1 1 1) single crystal yttria-stabilised zirconia (YSZ) substrates. Half of the samples were irradiated with 110 MeV 238U31+ ions to fluences of 5 Ă— 1010, 5 Ă— 1011 and 5 Ă— 1012 ions/cm2 to induce radiation damage, with the remainder kept for reference measurements. It was observed that as-produced UO2 films adopted the crystallographic orientation of their YSZ substrates. The irradiation fluences used in this study however, were not sufficient to cause any permanent change in the crystalline nature of UO2. It has been demonstrated that the effect of epitaxial re-crystallisation of the induced radiation damage can be quantified in terms of kernel average misorientation (KAM) and different crystallographic orientations of UO2 respond differently to ion irradiation

    Physiological temperatures reduce dimerization of dengue and Zika virus recombinant envelope proteins

    Get PDF
    The spread of dengue (DENV) and Zika virus (ZIKV) is a major public health concern. The primary target of antibodies that neutralize DENV and ZIKV is the envelope (E) glycoprotein, and there is interest in using soluble recombinant E (sRecE) proteins as subunit vaccines. However, the most potent neutralizing antibodies against DENV and ZIKV recognize epitopes on the virion surface that span two or more E proteins. Therefore, to create effective DENV and ZIKV vaccines, presentation of these quaternary epitopes may be necessary. The sRecE proteins from DENV and ZIKV crystallize as native-like dimers, but studies in solution suggest that these dimers are marginally stable. To better understand the challenges associated with creating stable sRecE dimers, we characterized the thermostability of sRecE proteins from ZIKV and three DENV serotypes, DENV2– 4. All four proteins irreversibly unfolded at moderate temperatures (46 –53 °C). At 23 °C and low micromolar concentrations, DENV2 and ZIKV were primarily dimeric, and DENV3– 4 were primarily monomeric, whereas at 37 °C, all four proteins were predominantly monomeric. We further show that the dissociation constant for DENV2 dimerization is very temperature-sensitive, ranging from <1 M at 25 °C to 50 M at 41 °C, due to a large exothermic enthalpy of binding of 79 kcal/mol. We also found that quaternary epitope antibody binding to DENV2– 4 and ZIKV sRecE is reduced at 37 °C. Our observation of reduced sRecE dimerization at physiological temperature highlights the need for stabilizing the dimer as part of its development as a subunit vaccine

    Ab initio and finite-temperature molecular dynamics studies of lattice resistance in tantalum

    Full text link
    This manuscript explores the apparent discrepancy between experimental data and theoretical calculations of the lattice resistance of bcc tantalum. We present the first results for the temperature dependence of the Peierls stress in this system and the first ab initio calculation of the zero-temperature Peierls stress to employ periodic boundary conditions, which are those best suited to the study of metallic systems at the electron-structure level. Our ab initio value for the Peierls stress is over five times larger than current extrapolations of experimental lattice resistance to zero-temperature. Although we do find that the common techniques for such extrapolation indeed tend to underestimate the zero-temperature limit, the amount of the underestimation which we observe is only 10-20%, leaving open the possibility that mechanisms other than the simple Peierls stress are important in controlling the process of low temperature slip.Comment: 12 pages and 9 figure

    Structural effects in UO<sub>2</sub> thin films irradiated with U ions

    Get PDF
    AbstractThis work presents the results of a detailed structural characterisation of irradiated and unirradiated single crystal thin films of UO2. Thin films of UO2 were produced by reactive magnetron sputtering onto (001), (110) and (111) single crystal yttria-stabilised zirconia (YSZ) substrates. Half of the samples were irradiated with 110MeV 238U31+ ions to fluences of 5Ă—1010, 5Ă—1011 and 5Ă—1012ions/cm2 to induce radiation damage, with the remainder kept for reference measurements. It was observed that as-produced UO2 films adopted the crystallographic orientation of their YSZ substrates. The irradiation fluences used in this study however, were not sufficient to cause any permanent change in the crystalline nature of UO2. It has been demonstrated that the effect of epitaxial re-crystallisation of the induced radiation damage can be quantified in terms of kernel average misorientation (KAM) and different crystallographic orientations of UO2 respond differently to ion irradiation

    Time-integrated luminosity recorded by the BABAR detector at the PEP-II e+e- collider

    Get PDF
    This article is the Preprint version of the final published artcile which can be accessed at the link below.We describe a measurement of the time-integrated luminosity of the data collected by the BABAR experiment at the PEP-II asymmetric-energy e+e- collider at the ϒ(4S), ϒ(3S), and ϒ(2S) resonances and in a continuum region below each resonance. We measure the time-integrated luminosity by counting e+e-→e+e- and (for the ϒ(4S) only) e+e-→μ+μ- candidate events, allowing additional photons in the final state. We use data-corrected simulation to determine the cross-sections and reconstruction efficiencies for these processes, as well as the major backgrounds. Due to the large cross-sections of e+e-→e+e- and e+e-→μ+μ-, the statistical uncertainties of the measurement are substantially smaller than the systematic uncertainties. The dominant systematic uncertainties are due to observed differences between data and simulation, as well as uncertainties on the cross-sections. For data collected on the ϒ(3S) and ϒ(2S) resonances, an additional uncertainty arises due to ϒ→e+e-X background. For data collected off the ϒ resonances, we estimate an additional uncertainty due to time dependent efficiency variations, which can affect the short off-resonance runs. The relative uncertainties on the luminosities of the on-resonance (off-resonance) samples are 0.43% (0.43%) for the ϒ(4S), 0.58% (0.72%) for the ϒ(3S), and 0.68% (0.88%) for the ϒ(2S).This work is supported by the US Department of Energy and National Science Foundation, the Natural Sciences and Engineering Research Council (Canada), the Commissariat à l’Energie Atomique and Institut National de Physique Nucléaire et de Physiquedes Particules (France), the Bundesministerium für Bildung und Forschung and Deutsche Forschungsgemeinschaft (Germany), the Istituto Nazionale di Fisica Nucleare (Italy), the Foundation for Fundamental Research on Matter (The Netherlands), the Research Council of Norway, the Ministry of Education and Science of the Russian Federation, Ministerio de Ciencia e Innovación (Spain), and the Science and Technology Facilities Council (United Kingdom). Individuals have received support from the Marie-Curie IEF program (European Union) and the A.P. Sloan Foundation (USA)

    Nuclear Alpha-Particle Condensates

    Full text link
    The α\alpha-particle condensate in nuclei is a novel state described by a product state of α\alpha's, all with their c.o.m. in the lowest 0S orbit. We demonstrate that a typical α\alpha-particle condensate is the Hoyle state (Ex=7.65E_{x}=7.65 MeV, 02+0^+_2 state in 12^{12}C), which plays a crucial role for the synthesis of 12^{12}C in the universe. The influence of antisymmentrization in the Hoyle state on the bosonic character of the α\alpha particle is discussed in detail. It is shown to be weak. The bosonic aspects in the Hoyle state, therefore, are predominant. It is conjectured that α\alpha-particle condensate states also exist in heavier nαn\alpha nuclei, like 16^{16}O, 20^{20}Ne, etc. For instance the 06+0^+_6 state of 16^{16}O at Ex=15.1E_{x}=15.1 MeV is identified from a theoretical analysis as being a strong candidate of a 4α4\alpha condensate. The calculated small width (34 keV) of 06+0^+_6, consistent with data, lends credit to the existence of heavier Hoyle-analogue states. In non-self-conjugated nuclei such as 11^{11}B and 13^{13}C, we discuss candidates for the product states of clusters, composed of α\alpha's, triton's, and neutrons etc. The relationship of α\alpha-particle condensation in finite nuclei to quartetting in symmetric nuclear matter is investigated with the help of an in-medium modified four-nucleon equation. A nonlinear order parameter equation for quartet condensation is derived and solved for α\alpha particle condensation in infinite nuclear matter. The strong qualitative difference with the pairing case is pointed out.Comment: 71 pages, 41 figures, review article, to be published in "Cluster in Nuclei (Lecture Notes in Physics) - Vol.2 -", ed. by C. Beck, (Springer-Verlag, Berlin, 2011
    • …
    corecore