1,228 research outputs found

    137CS gamma-ray detection at Summit, Greenland

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    Global fall-out from atmospheric testing of thermonuclear weapons produced horizon markers corresponding to the initiation of testing in 1953 and the maximum fall-out in 1963. The radioactive isotope 137Cs associated with these events has a half-life of 30.2 years. Therefore, with the appropriate radiation detectors, this fall-out can be used as a long-term temporal indicator in glaciers and snowpack. A prototype Îł-ray detector system was successfully tested and was used to make in-situ measurements of the 137Cs marker in a borehole at Summit, Greenland. The system consisted of a 7.6 cm by 7.6 cm NaI (Tl) scintillation crystal/photomultiplier detector, commercial pre-amplifier, amplifier and power supplies, and a microcomputer-based pulse-height analyzer. The measurements were made in boreholes of 25.4 cm and 12.7 cm diameter to depths of 22 m. Based on the results reported here, the Îł-ray detection technique promises to be a powerful way to locate quickly horizon markers in the field. -Author

    When faces feel familiar: The role of affective signals in face recognition

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    Previous research has suggested that there may be an increase in positive affect and autonomic arousal in response to seeing a familiar face. These studies rarely distinguish between faces for which there is only a “feeling” of familiarity, and faces for which this feeling is accompanied by the retrieval of semantic knowledge about the individual. In the current study we aimed to make that distinction. Participants made recognition judgments on famous and non-famous faces while galvanic skin responses (GSR), zygomatic muscle activity, and heart rate (HR) were recorded. We found increases in GSR (autonomic arousal), and zygomatic muscle activity (positive affect) for faces that were accompanied by semantic-access. These results suggest that the positive affective signal may be generated as a result of retrieving semantic information about a face, rather than as a result of some other mechanism, such as processing fluency

    Feasibility randomised controlled trial comparing TRAK-ACL digital rehabilitation intervention plus treatment as usual versus treatment as usual for patients following anterior cruciate ligament reconstruction

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    Objectives: To evaluate the feasibility of trialling taxonomy for the rehabilitation of knee conditions-ACL (TRAK-ACL), a digital health intervention that provides health information, personalised exercise plans and remote clinical support combined with treatment as usual (TAU), for people following ACL reconstruction. Methods: The study design was a two-arm parallel randomised controlled trial (RCT). Eligible participants were English-speaking adults who had undergone ACL reconstruction within the last 12 weeks, had access to the internet and could provide informed consent. Recruitment took place at three sites in the UK. TRAK-ACL intervention was an interactive website informed by behaviour change technique combined with TAU. The comparator was TAU. Outcomes were: recruitment and retention; completeness of outcome measures at follow-up; fidelity of intervention delivery and engagement with the intervention. Individuals were randomised using a computer-generated random number sequence. Blinded assessors allocated groups and collected outcome measures. Results: Fifty-nine people were assessed for eligibility at two of the participating sites, and 51 were randomised; 26 were allocated to TRAK-ACL and 25 to TAU. Follow-up data were collected on 44 and 40 participants at 3 and 6 months, respectively. All outcome measures were completed fully at 6 months except the Client Service Receipt Inventory. Two patients in each arm did not receive the treatment they were randomised to. Engagement with TRAK-ACL intervention was a median of 5 logins (IQR 3-13 logins), over 18 weeks (SD 12.2 weeks). Conclusion: TRAK-ACL would be suitable for evaluation of effectiveness in a fully powered RCT

    Spectroscopy and Imaging Performance of the Liquid Xenon Gamma-Ray Imaging Telescope (LXeGRIT)

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    LXeGRIT is a balloon-borne Compton telescope based on a liquid xenon time projection chamber (LXeTPC) for imaging cosmic \g-rays in the energy band of 0.2-20 MeV. The detector, with 400 cm2^2 area and 7 cm drift gap, is filled with high purity LXe. Both ionization and scintillation light signals are detected to measure the energy deposits and the three spatial coordinates of individual \g -ray interactions within the sensitive volume. The TPC has been characterized with repeated measurements of its spectral and Compton imaging response to \g -rays from radioactive sources such as \na, \cs, \yt and Am-Be. The detector shows a linear response to \g -rays in the energy range 511 keV -4.4 MeV, with an energy resolution (FWHM) of \Delta E/E=8.8% \: \sqrt{1\MeV /E}. Compton imaging of \yt \g -ray events with two detected interactions is consistent with an angular resolution of ∌\sim 3 degrees (RMS) at 1.8 MeV.Comment: To appear in: Hard X-Ray, Gamma-Ray and Neutron Detector Physics XI, 2000; Proc. SPIE, vol. 4140; K.A. Flanagan & O.H. Siegmund, ed

    Can podiatrists impact upon self-management for people with type 2 diabetes? A randomised controlled trial

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    Type diabetes has reached epidemic levels in the UK. It is the principle reason for lower limb amputation, renal failure and blindness as well as a major cause of fatal heart disease. Effective management of the condition inevitably means good self management by people living with diabetes on a daily basis. Dietary changes to improve blood sugar (HbA1c) control provide on-going challenges for both patients and health care professionals. Podiatrists are the most likely health profession to have regular consultations with diabetic patients, particularly once complications have developed. They are well placed to implement long-term support of self-management strategies based on a valid theoretical framework.sch_podpub2794pu

    PizzaBlock: Designing Artefacts and Roleplay to Understand Decentralised Identity Management Systems

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    This pictorial describes in detail the design, and multiple iterations, of PizzaBlock - a role-playing game and design workshop to introduce non-technical participants to decentralised identity management systems. We have so far played this game with six different audiences, with over one hundred participants - iterating the design of the artefacts and gameplay each time. In this pictorial, we reflect on this RtD project to unpack: a) How we designed artefacts and roleplay to explore decentralised technologies and networks; b) How we communicated the key challenges and parameters of a complex system, through the production of a playable, interactive, analogue representation of that technology; c) How we struck a balance between playful tangible gameplay and high-fidelity technical analogy; and d) How approaches like PizzaBlock invite engagement with complex infrastructures and can support more participatory approaches to their design

    Gamma-ray observations of the Crab Region using a coded-aperture telescope

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    The region of the Galactic anticenter, including the Crab Nebula, was observed during a balloon flight of the University of New Hampshire Directional Gamma-Ray Telescope employing the coded-aperture imaging technique to image celestial gamma-radiation between 160 keV and 9.3 MeV. The background systematics are treated with a simple and relatively straightforward correction procedure. The results demonstrate that the coded-aperture procedure is a viable approach for imaging not only point sources of radiation, but also extended sources of emission. The results for the Crab\u27s photon spectrum are consistent with a power-law spectrum. Upper limits on the flux levels of line emission at 405 keV and 1050 keV and on the flux from the X-ray binary source A0535 + 26 and diffuse Galactic emission from the anticenter region are derived

    Electronic Footprints in the Sand: Technologies for Assisting Domestic Violence Survivors

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    With the rapid growth and spread of Internet-based social support systems, the impact that these systems can make to society – be it good or bad – has become more significant and can make a real difference to people’s lives. As such, various aspects of these systems need to be carefully investigated and analysed, including their security/privacy issues. In this paper, we present our work in designing and implementing various technological features that can be used to assist domestic violence survivors in obtaining help without leaving traces which might lead to further violence from their abuser. This case study serves as the core of our paper, in which we outline our approach, various de- sign considerations – including difficulties in keeping browsing history private, our currently implemented solutions (single use URL, targeted history sanitita- tion agent, and secret graphical gateway), as well as novel ideas for future work (including location-based service advertising and deployment in the wild)

    Keeping an eye on decellularized corneas: a review of methods, characterization and applications

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    The worldwide limited availability of suitable corneal donor tissue has led to the development of alternatives, including keratoprostheses (Kpros) and tissue engineered (TE) constructs. Despite advances in bioscaffold design, there is yet to be a corneal equivalent that effectively mimics both the native tissue ultrastructure and biomechanical properties. Human decellularized corneas (DCs) could offer a safe, sustainable source of corneal tissue, increasing the donor pool and potentially reducing the risk of immune rejection after corneal graft surgery. Appropriate, human-specific, decellularization techniques and high-resolution, non-destructive analysis systems are required to ensure reproducible outputs can be achieved. If robust treatment and characterization processes can be developed, DCs could offer a supplement to the donor corneal pool, alongside superior cell culture systems for pharmacology, toxicology and drug discovery studies
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