2,297 research outputs found

    Handbook for the estimation of microwave propagation effects: Link calculations for earth-space paths (path loss and noise estimation)

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    A single model for a standard of comparison for other models when dealing with rain attenuation problems in system design and experimentation is proposed. Refinements to the Global Rain Production Model are incorporated. Path loss and noise estimation procedures as the basic input to systems design for earth-to-space microwave links operating at frequencies from 1 to 300 GHz are provided. Topics covered include gaseous absorption, attenuation by rain, ionospheric and tropospheric scintillation, low elevation angle effects, radome attenuation, diversity schemes, link calculation, and receiver noise emission by atmospheric gases, rain, and antenna contributions

    Laboratory guide to early life history stages of northeast Pacific fishes

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    This laboratory guide presents taxonomic information on eggs and larvae of fishes of the Northeast Pacific Ocean (north of California) and the eastern Bering Sea. Included are early-life-history series, illustrations, and comparative descriptions of 232 species expected to spawn here, out of a total 627 species known to occur in marine waters of this area. Meristic and general life-history data are included, as well as diagnostic characters to help identify eggs and larvae. Most of this information has been gleaned from literature, with the addition of 200 previously unpublished illustrations. (PDF file contains 654 pages.

    Can we see defects in capacitance measurements of thin-film solar cells?

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    Thermal admittance spectroscopy and capacitance-voltage measurements are well established techniques to study recombination-active deep defect levels and determine the shallow dopant concentration in photovoltaic absorbers. Applied to thin-film solar cells or any device stack consisting of multiple layers, interpretation of these capacitance-based techniques is ambiguous at best. We demonstrate how to assess electrical measurements of thin-film devices and develop a range of criteria that allow to estimate whether deep defects could consistently explain a given capacitance measurement. We show that a broad parameter space, achieved by exploiting bias voltage, time, and illumination as additional experimental parameters in admittance spectroscopy, helps to distinguish between deep defects and capacitive contributions from transport barriers or additional layers in the device stack. On the example of Cu(In,Ga)Se2 thin-film solar cells, we show that slow trap states are indeed present but cannot be resolved in typical admittance spectra. We explain the common N1 signature by the presence of a capacitive barrier layer and show that the shallow net dopant concentration is not distributed uniformly within the depth of the absorber

    Adult Social Work and High Risk Domestic Violence Cases

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    Summary This article focuses on adult social work’s response in England to high-risk domestic violence cases and the role of adult social workers in Multi-Agency Risk and Assessment Conferences. (MARACs). The research was undertaken between 2013-2014 and focused on one city in England and involved the research team attending MARACs, Interviews with 20 adult social workers, 24 MARAC attendees, 14 adult service users at time T1 (including follow up interviews after six months, T2), focus groups with IDVAs and Women’s Aid and an interview with a Women’s Aid service user. Findings The findings suggest that although adult social workers accept the need to be involved in domestic violence cases they are uncertain of what their role is and are confused with the need to operate a parallel domestic violence and adult safeguarding approach, which is further, complicated by issues of mental capacity. MARACS are identified as overburdened, under-represented meetings staffed by committed managers. However, they are in danger of becoming managerial processes neglecting the service users they are meant to protect. Applications The article argues for a re-engagement of adult social workers with domestic violence that has increasingly become over identified with child protection. It also raises the issue whether MARACS remain fit for purpose and whether they still represent the best possible response to multi-agency coordination and practice in domestic violence

    Curvature-coupling dependence of membrane protein diffusion coefficients

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    We consider the lateral diffusion of a protein interacting with the curvature of the membrane. The interaction energy is minimized if the particle is at a membrane position with a certain curvature that agrees with the spontaneous curvature of the particle. We employ stochastic simulations that take into account both the thermal fluctuations of the membrane and the diffusive behavior of the particle. In this study we neglect the influence of the particle on the membrane dynamics, thus the membrane dynamics agrees with that of a freely fluctuating membrane. Overall, we find that this curvature-coupling substantially enhances the diffusion coefficient. We compare the ratio of the projected or measured diffusion coefficient and the free intramembrane diffusion coefficient, which is a parameter of the simulations, with analytical results that rely on several approximations. We find that the simulations always lead to a somewhat smaller diffusion coefficient than our analytical approach. A detailed study of the correlations of the forces acting on the particle indicates that the diffusing inclusion tries to follow favorable positions on the membrane, such that forces along the trajectory are on average smaller than they would be for random particle positions.Comment: 16 pages, 8 figure

    A cross-sectional study of vascular risk factors in a rural South African population : data from the Southern African Stroke Prevention Initiative (SASPI)

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    Background: Rural sub-Saharan Africa is at an early stage of economic and health transition. It is predicted that the 21st century will see a serious added economic burden from non-communicable disease including vascular disease in low-income countries as they progress through the transition. The stage of vascular disease in a population is thought to result from the prevalence of vascular risk factors. Already hypertension and stroke are common in adults in sub-Saharan Africa. Using a multidisciplinary approach we aimed to assess the prevalence of several vascular risk factors in Agincourt, a rural demographic surveillance site in South Africa. Methods: We performed a cross sectional random sample survey of adults aged over 35 in Agincourt (population ≈ 70 000). Participants were visited at home by a trained nurse who administered a questionnaire, carried out clinical measurements and took a blood sample. From this we assessed participants' history of vascular risk, blood pressure using an OMRON 705 CP monitor, waist circumference, body mass index (BMI), ankle brachial index (ABI), and total and HDL cholesterol. Results: 402 people (24% men) participated. There was a high prevalence of smoking in men, but the number of cigarettes smoked was small. There was a striking difference in mean BMI between men and women (22.8 kg/m2 versus 27.2 kg/m2), but levels of blood pressure were very similar. 43% of participants had a blood pressure greater than 140/90 or were on anti-hypertensive treatment and 37% of participants identified with measured high blood pressure were on pharmacological treatment. 12% of participants had an ABI of < 0.9, sugesting the presence of sub-clinical atheroma. 25.6% of participants had a total cholesterol level > 5 mmol/l. Conclusion: We found a high prevalence of hypertension, obesity in women, and a suggestion of subclinical atheroma despite relatively favourable cholesterol levels in a rural South African population. South Africa is facing the challenge of an emerging epidemic of vascular disease. Research to establish the social determinates of these risk factors and interventions to reduce both individual and population risk are required

    DrinkWise, enjoy responsibly: News frames, branding and alcohol

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    This article examines the communicative activities and press coverage of the alcohol industry-funded social-change organisation DrinkWise. Established in 2005, DrinkWise funds health research in universities, runs public health campaigns and engages in public relations activities. We use a framing analysis to examine the way DrinkWise frames problems, judgements and solutions related to alcohol consumption and policy. The aim of this analysis is to examine how journalistic practice legitimises DrinkWise and facilitates the organisation’s communicative activities. In addition, we consider how DrinkWise’s representation in the press works alongside the organisation’s array of communicative activities to facilitate the commercial objectives of the alcohol industry. We draw on the implications of this analysis to conceptualise how distinct forms of communicative work – such as academic research, policy-making, journalism and marketing, advertising and public relations – are interconnected
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