12,937 research outputs found

    Beyond the rainbow: effects from pion back-coupling

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    We investigate hadronic unquenching effects in light quarks and mesons. To this end we take into account the back-coupling of the pion onto the quark propagator within the non-perturbative continuum framework of Schwinger-Dyson equations (SDE) and Bethe-Salpeter equations (BSE). We improve on a previous approach by explicitly solving both the coupled system of DSEs and BSEs in the complex plane and the normalisation problem for Bethe-Salpeter kernels depending on the total momentum of the meson. As a result of our study we find considerable unquenching effects in the spectrum of light pseudoscalar, vector and axial-vector mesons.Comment: 9 pages, 5 figures. Minor typos corrected. Version to appear in PR

    Probing the gluon self-interaction in light mesons

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    We investigate masses and decay constants of light mesons from a coupled system of Dyson--Schwinger and Bethe--Salpeter equations. We explicitly take into account dominant non-Abelian contributions to the dressed quark-gluon vertex stemming from the gluon self-interaction. We construct the corresponding Bethe-Salpeter kernel that satisfies the axial-vector Ward-Takahashi identity. Our numerical treatment fully includes all momentum dependencies with all equations solved completely in the complex plane. This approach goes well beyond the rainbow-ladder approximation and permits us to investigate the influence of the gluon self-interaction on the properties of mesons. As a first result we find indications of a nonperturbative cancellation of the gluon self-interaction contributions and pion cloud effects in the mass of the rho-meson.Comment: 4 pages, 5 figures. Matches published version in PR

    The sexual health needs of looked after young people; findings from qualitative interviews led through public health and health psychology.

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    Background - Looked after young people (LAYP) have poorer sexual health outcomes than their peers. However, research seldom examines the health needs of, or intervenes with, this group. The aim of the current study was to identify LAYP's perceived sexual health needs and explore sources of sexual health information, knowledge levels, concerns and service preferences. Methods - Looked after young people within Fife, Scotland, were recruited through their workers and carers to participate in qualitative semi-structured interviews. Those aged 12–19 years were targeted for recruitment. National Health Services ethics approval was granted. Thematic analysis was conducted using NVivo. Results - Interviews were conducted with 10 LAYP. Key themes included gaps in knowledge, and gaps between knowledge and behaviour. Being ‘looked after’ may have negative consequences on knowledge, sources of support and safer sex. A flexible, one-to-one service, aimed at several lifestyle issues, not solely sexual health, was preferred by respondents. Conclusion - Looked after young people require support to bridge the gap between knowledge and behaviour and several theories relevant to the findings have been identified. Participants desired more support around a range of health issues, which may come from school, workers and carers, as well as health professionals. Further research examining effective interventions with this group is crucial to improve outcomes

    A qualitative study of primary care professionals’ views of case finding for depression in patients with diabetes or coronary heart disease in the UK

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    <p>Background Routinely conducting case finding (also commonly referred to as screening) in patients with chronic illness for depression in primary care appears to have little impact. We explored the views and experiences of primary care nurses, doctors and managers to understand how the implementation of case finding/screening might impact on its effectiveness.</p> <p>Methods Two complementary qualitative focus group studies of primary care professionals including nurses, doctors and managers, in five primary care practices and five Community Health Partnerships, were conducted in Scotland.</p> <p>Results We identified several features of the way case finding/screening was implemented that may lead to systematic under-detection of depression. These included obstacles to incorporating case finding/screening into a clinical review consultation; a perception of replacing individualised care with mechanistic assessment, and a disconnection for nurses between management of physical and mental health. Far from being a standardised process that encouraged detection of depression, participants described case finding/screening as being conducted in a way which biased it towards negative responses, and for nurses, it was an uncomfortable task for which they lacked the necessary skills to provide immediate support to patients at the time of diagnosis.</p> <p>Conclusion The introduction of case finding/screening for depression into routine chronic illness management is not straightforward. Routinized case finding/screening for depression can be implemented in ways that may be counterproductive to engagement (particularly by nurses), with the mental health needs of patients living with long term conditions. If case finding/screening or engagement with mental health problems is to be promoted, primary care nurses require more training to increase their confidence in raising and dealing with mental health issues and GPs and nurses need to work collectively to develop the relational work required to promote cognitive participation in case finding/screening.</p&gt

    The cutting edge - Micro-CT for quantitative toolmark analysis of sharp force trauma to bone

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    Toolmark analysis involves examining marks created on an object to identify the likely tool responsible for creating those marks (e.g., a knife). Although a potentially powerful forensic tool, knife mark analysis is still in its infancy and the validation of imaging techniques as well as quantitative approaches is ongoing. This study builds on previous work by simulating real-world stabbings experimentally and statistically exploring quantitative toolmark properties, such as cut mark angle captured by micro-CT imaging, to predict the knife responsible. In Experiment 1 a mechanical stab rig and two knives were used to create 14 knife cut marks on dry pig ribs. The toolmarks were laser and micro-CT scanned to allow for quantitative measurements of numerous toolmark properties. The findings from Experiment 1 demonstrated that both knives produced statistically different cut mark widths, wall angle and shapes. Experiment 2 examined knife marks created on fleshed pig torsos with conditions designed to better simulate real-world stabbings. Eight knives were used to generate 64 incision cut marks that were also micro-CT scanned. Statistical exploration of these cut marks suggested that knife type, serrated or plain, can be predicted from cut mark width and wall angle. Preliminary results suggest that knives type can be predicted from cut mark width, and that knife edge thickness correlates with cut mark width. An additional 16 cut marks walls were imaged for striation marks using scanning electron microscopy with results suggesting that this approach might not be useful for knife mark analysis. Results also indicated that observer judgements of cut mark shape were more consistent when rated from micro-CT images than light microscopy images. The potential to combine micro-CT data, medical grade CT data and photographs to develop highly realistic virtual models for visualisation and 3D printing is also demonstrated. This is the first study to statistically explore simulated real-world knife marks imaged by micro-CT to demonstrate the potential of quantitative approaches in knife mark analysis. Findings and methods presented in this study are relevant to both forensic toolmark researchers as well as practitioners. Limitations of the experimental methodologies and imaging techniques are discussed, and further work is recommended

    Challenges in the delivery of e-government through kiosks

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    Kiosks are increasingly being heralded as a technology through which governments, government departments and local authorities or municipalities can engage with citizens. In particular, they have attractions in their potential to bridge the digital divide. There is some evidence to suggest that the citizen uptake of kiosks and indeed other channels for e-government, such as web sites, is slow, although studies on the use of kiosks for health information provision offer some interesting perspectives on user behaviour with kiosk technology. This article argues that the delivery of e-government through kiosks presents a number of strategic challenges, which will need to be negotiated over the next few years in order that kiosk applications are successful in enhancing accessibility to and engagement with e-government. The article suggests that this involves consideration of: the applications to be delivered through a kiosk; one stop shop service and knowledge architectures; mechanisms for citizen identification; and, the integration of kiosks within the total interface between public bodies and their communities. The article concludes by outlining development and research agendas in each of these areas.</p

    Modelling spatial and inter-annual variations of nitrous oxide emissions from UK cropland and grasslands using DailyDayCent

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    This work contributes to the Defra funded projects AC0116: ‘Improving the nitrous oxide inventory’, and AC0114: ‘Data Synthesis, Management and Modelling’. Funding for this work was provided by the UK Department for Environment, Food and Rural Affairs (Defra) AC0116 and AC0114, the Department of Agriculture, Environment and Rural Affairs for Northern Ireland, the Scottish Government and the Welsh Government. Rothamsted Research receives strategic funding from the Biotechnology and Biological Sciences Research Council. This study also contributes to the projects: N-Circle (BB/N013484/1), U-GRASS (NE/M016900/1) and GREENHOUSE (NE/K002589/1).Peer reviewedPublisher PD

    Near IR Spectroscopic monitoring of WR 140 during the 2001 periastron passage

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    We present new spectra of WR 140 (HD 193793) in the JHK bands with some covering the 1.083-micron He I emission line at higher resolution, observed between 2000 October and 2003 May to cover its 2001 periastron passage. The WC7 + O4-5 spectroscopic binary WR 140 is the prototype of colliding-wind, episodic dust-making Wolf-Rayet systems which also show strong variations in radio and X-ray emission. The JHK spectra showed changes in continuum and in the equivalent widths of the WC emission lines, consistent with formation of dust starting between 2001 January 3 and March 26 (orbital phases 0.989 and 0.017) and its subsequent fading and cooling. The 1.083-micron He I line has a P-Cygni profile which showed variations in both absorption and emission components as WR 140 went through periastron passage. The variation of the absorption component yielded tight constraints on the geometry of the wind-collision region, giving theta = 50 +/- 8 degrees for the opening semi-angle of the interaction `cone', indicating a wind-momentum ratio of the O to the WR star=0.1, about three times larger than previously believed. As the system approached periastron, the emission component showed the appearance of a significant sub-peak, movement of which across the profile was seen to be consistent with its formation in wind material flowing along the contact discontinuity between the two stellar winds and the changing orientation of the colliding wind region. The flux carried in the sub-peak exceeded the X-ray fluxes measured at previous periastron passages. This additional source of radiative cooling of the shock-heated gas probably causes it to depart from being adiabatic around periastron passage, thereby accounting for the departure of the X-ray flux from its previously expected 1/d1/d-dependency.Comment: Accepted for publication in MNRAS - 13 Pages, 10 figure
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