1,300 research outputs found

    The effects of aetiology on outcome in patients treated with cardiac resynchronization therapy in the CARE-HF trial

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    Aims: Cardiac dyssynchrony is common in patients with heart failure, whether or not they have ischaemic heart disease (IHD). The effect of the underlying cause of cardiac dysfunction on the response to cardiac resynchronization therapy (CRT) is unknown. This issue was addressed using data from the CARE-HF trial.Methods and resultsPatients (n = 813) were grouped by heart failure aetiology (IHD n = 339 vs. non-IHD n = 473), and the primary composite (all-cause mortality or unplanned hospitalization for a major cardiovascular event) and principal secondary (all-cause mortality) endpoints analysed. Heart failure severity and the degree of dyssynchrony were compared between the groups by analysing baseline clinical and echocardiographic variables. Patients with IHD were more likely to be in NYHA class IV (7.5 vs. 4.0; P = 0.03) and to have higher NT-proBNP levels (2182 vs. 1725 pg/L), indicating more advanced heart failure. The degree of dyssynchrony was more pronounced in patients without IHD (assessed using mean QRS duration, interventricular mechanical delay, and aorta-pulmonary pre-ejection time). Left ventricular ejection fraction and left ventricular end-systolic volume improved to a lesser extent in the IHD group (4.53 vs. 8.50 and -35.68 vs. -58.52 cm 3). Despite these differences, CRT improved all-cause mortality, NYHA class, and hospitalization rates to a similar extent in patients with or without IHD.ConclusionThe benefits of CRT in patients with or without IHD were similar in relative terms in the CARE-HF study but as patients with IHD had a worse prognosis, the benefit in absolute terms may be greater

    Mitochondrial precursor proteins are imported through a hydrophilic membrane environment

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    We have analyzed how translocation intermediates of imported mitochondrial precursor proteins, which span contact sites, interact with the mitochondrial membranes. F1-ATPase subunit β(F1β) was trapped at contact sites by importing it into Neurospora mitochondria in the presence of low levels of nucleoside triphosphates. This F1β translocation intermediate could be extracted from the membranes by treatment with protein denaturants such as alkaline pH or urea. By performing import at low temperatures, the ADP/ATP carrier was accumulated in contact sites of Neurospora mitochondria and cytochrome b2 in contact sites of yeast mitochondria. These translocation intermediates were also extractable from the membranes at alkaline pH. Thus, translocation of precursor proteins across mitochondrial membranes seems to occur through an environment which is accessible to aqueous perturbants. We propose that proteinaceous structures are essential components of a translocation apparatus present in contact sites

    Annihilation vs. Decay: Constraining dark matter properties from a gamma-ray detection

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    Most proposed dark matter candidates are stable and are produced thermally in the early Universe. However, there is also the possibility of unstable (but long-lived) dark matter, produced thermally or otherwise. We propose a strategy to distinguish between dark matter annihilation and/or decay in the case that a clear signal is detected in gamma-ray observations of Milky Way dwarf spheroidal galaxies with gamma-ray experiments. The sole measurement of the energy spectrum of an indirect signal would render the discrimination between these cases impossible. We show that by examining the dependence of the intensity and energy spectrum on the angular distribution of the emission, the origin could be identified as decay, annihilation, or both. In addition, once the type of signal is established, we show how these measurements could help to extract information about the dark matter properties, including mass, annihilation cross section, lifetime, dominant annihilation and decay channels, and the presence of substructure. Although an application of the approach presented here would likely be feasible with current experiments only for very optimistic dark matter scenarios, the improved sensitivity of upcoming experiments could enable this technique to be used to study a wider range of dark matter models.Comment: 29 pp, 8 figs; replaced to match published version (minor changes and some new references

    Young people, crime and school exclusion: a case of some surprises

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    During the 1990s the number of young people being permanently excluded from schools in England and Wales increased dramatically from 2,910 (1990/91) to a peak of 12,700 (1996/97). Coinciding with this rise was a resurgence of the debate centring on lawless and delinquent youth. With the publication of Young People and Crime (Graham and Bowling 1995) and Misspent Youth (Audit Commission 1996) the 'common sense assumption' that exclusion from school inexorably promoted crime received wide support, with the school excludee portrayed as another latter day 'folk devil'. This article explores the link between school exclusion and juvenile crime, and offers some key findings from a research study undertaken with 56 young people who had experience of being excluded from school. Self-report interview questions reveal that whilst 40 of the young people had offended, 90% (36) reported that the onset of their offending commenced prior to their first exclusion. Moreover, 50 (89.2% of the total number of young people in the sample), stated that they were no more likely to offend subsequent to being excluded and 31 (55.4%) stated that they were less likely to offend during their exclusion period. Often, this was because on being excluded, they were 'grounded' by their parents

    The politics of the digital single market:Culture vs. competition vs. copyright

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    This paper examines the implications for European music culture of the European Union’s Digital Single Market strategy. It focuses on the regulatory framework being created for the management of copyright policy, and in particular the role played by Collective Management Organisations (or Collecting Societies). One of the many new opportunities created by digitalization has been the music streaming services. These depend on consumers being able to access music wherever they are, but such a system runs counter to the management of rights on a national basis and through collecting organisations who act as monopolies within their own territories. The result has been ‘geo-blocking’. The EU has attempted to resolve this problem in a variety of ways, most recently in a Directive designed to reform the CMOs. In this paper, we document these various efforts, showing them to be motivated by a deep-seated and persisting belief in the capacity of ‘competition’ to resolve problems that, we argue, actually lie elsewhere - in copyright policy itself. The result is that the EU’s intervention fails to address its core concern and threatens the diversity of European music culture by rewarding those who are already commercially successful

    Limits on the high-energy gamma and neutrino fluxes from the SGR 1806-20 giant flare of December 27th, 2004 with the AMANDA-II detector

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    On December 27th 2004, a giant gamma flare from the Soft Gamma-ray Repeater 1806-20 saturated many satellite gamma-ray detectors. This event was by more than two orders of magnitude the brightest cosmic transient ever observed. If the gamma emission extends up to TeV energies with a hard power law energy spectrum, photo-produced muons could be observed in surface and underground arrays. Moreover, high-energy neutrinos could have been produced during the SGR giant flare if there were substantial baryonic outflow from the magnetar. These high-energy neutrinos would have also produced muons in an underground array. AMANDA-II was used to search for downgoing muons indicative of high-energy gammas and/or neutrinos. The data revealed no significant signal. The upper limit on the gamma flux at 90% CL is dN/dE < 0.05 (0.5) TeV^-1 m^-2 s^-1 for gamma=-1.47 (-2). Similarly, we set limits on the normalization constant of the high-energy neutrino emission of 0.4 (6.1) TeV^-1 m^-2 s^-1 for gamma=-1.47 (-2).Comment: 14 pages, 3 figure

    Starting to Stop: Young Offenders' Desistance from Crime

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    This paper explores the complexities of the interplay between structural and agentic changes in 21 young offenders' lives as they start to stop offending. The young people's ability to desist from crime was dependent upon their engagement with a 'hook for change', their development of prosocial relationships and 'knifing off' of elements of their offending past, the extent of their identity change, and their confidence about desistance. Desistance was less likely in the absence of a 'hook' and where offenders were running a 'condemnation script'. The study challenges previous research that argues that desistance from crime in adolescence is unlikely

    Reliability of the tuck jump injury risk screening assessment in elite male youth soccer players

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    Altered neuromuscular control has been suggested as a mechanism for injury in soccer players. Ligamentous injuries most often occur during dynamic movements, such as decelerations from jump-landing maneuvers where high risk movement patterns are present. The assessment of kinematic variables during jump-landing tasks as part of a pre-participation screen is useful in the identification of injury risk. An example of a field-based screening tool is the repeated tuck jump assessment. The purpose of this study was to analyze the within-subject variation of the tuck jump screening assessment in elite male youth soccer players. 25 pre and 25 post-peak height velocity (PHV) elite male youth soccer players from the academy of a professional English soccer club completed the assessment. A test, re-test design was used to explore the within-subject inter-session reliability. Technique was graded retrospectively against the 10-point criteria set out in the screening protocol using two-dimensional video cameras. The typical error range reported for tuck jump total score (0.90 – 1.01 in pre and post-PHV players respectively) was considered acceptable. When each criteria was analyzed individually, Kappa coefficient determined that knee valgus was the only criterion to reach substantial agreement across the two test sessions for both groups. The results of this study suggest that although tuck jump total score may be reliably assessed in elite male youth soccer players, caution should be applied in solely interpreting the composite score due to the high within-subject variation in a number of the individual criteria. Knee valgus may be reliably used to screen elite youth male soccer players for this plyometric technique error and for test, re-test comparison

    Relationship between muscular extensibility, strength and stability and the transmission of impacts during fatigued running.

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    The aim was to analyse the relationship between isokinetic strength, dynamic stability, muscular extensibility and impacts transmission during fatigued running. Low- and high-frequency impacts related to body movements and the severity of impacts, respectively were assessed in 17 male recreational runners, before and after a treadmill running fatigue protocol, using a triaxial accelerometry system. High-frequency impacts in the tibia were negatively correlated to the knee angle at which the quadriceps peak torque was reached (p = 0.014), and also to the extensibility of the hamstrings and soleus (p = 0.001 and p = 0.023, respectively). The increases of high-frequency impacts in tibia caused by fatigue were positively related to the knee angle at which the hamstrings peak torque was reached (p = 0.001) and to stability after landing (p = 0.007). The attenuation of high-frequency impacts was positively related to hamstrings/quadriceps ratio of strength (p = 0.010) and to stability (p = 0.006). Limiting possible deficits in hamstring and soleus range of motion, improving stability after landing, developing hamstring and quadriceps strength in elongated muscle range, and maintaining a balanced ratio of hamstring/quadriceps strength could help to reduce the injury risk in running

    Cryogenic Insulation Systems

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    The results of a comparative study of cryogenic insulation systems performed are presented. The key aspects of thermal insulation relative to cryogenic system design, testing, manufacturing, and maintenance are discussed. An overview of insulation development from an energy conservation perspective is given. Conventional insulation materials for cryogenic applications provide three levels of thermal conductivity. Actual thermal performance of standard multilayer insulation (MLI) is several times less than laboratory performance and often 10 times worse than ideal performance. The cost-effectiveness of the insulation system depends on thermal performance; flexibility and durability; ease of use in handling, installation, and maintenance; and overall cost including operations, maintenance, and life cycle. Results of comprehensive testing of both conventional and novel materials such as aerogel composites using cryostat boil-off methods are given. The development of efficient, robust cryogenic insulation systems that operate at a soft vacuum level is the primary focus of this paper
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