2,285 research outputs found

    Why lose weight? Reasons for seeking weight loss by overweight but otherwise healthy men

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    OBJECTIVE: To identify the reasons for seeking weight loss in overweight or obese but otherwise healthy men. DESIGN: Interviews, prior to intervention, with subjects who had volunteered to participate in a work-site-based weight loss study. SUBJECTS: Ninety-one overweight=obese male workers. Mean age 41, range 18 – 55 y, mean body mass index (BMI) 31.0, range 26.2 – 41.6 kg=m2. MEASUREMENTS: Anthropometric measurements; body weight and height. Body mass index calculated. A short interview using open questions to determine the individuals reason for seeking weight loss. RESULTS: The message that weight loss is beneficial to health for the overweight was recognized by all subjects regardless of BMI, and was reported as the main factor for attempting weight loss. Improved fitness and effects on appearance and well-being were reported half as often as the primary reason for weight loss. CONCLUSION: Overweight lay members of the public have accepted the health education message that weight loss can improve health. Overweight but otherwise healthy men who responded, of their own accord, to an electronic mail message offering help to lose weight did not regard obesity and overweight as primarily a cosmetic issue. This is still, however, important, especially to younger people

    Accretion disc winds in tidal disruption events: Ultraviolet spectral lines as orientation indicators

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    ABSTRACT Some tidal disruption events (TDEs) exhibit blueshifted broad absorption lines (BALs) in their rest-frame ultraviolet (UV) spectra, while others display broad emission lines (BELs). Similar phenomenology is observed in quasars and accreting white dwarfs, where it can be interpreted as an orientation effect associated with line formation in an accretion disc wind. We propose and explore a similar unification scheme for TDEs. We present synthetic UV spectra for disc and wind-hosting TDEs, produced by a state-of-the-art Monte Carlo ionization and radiative transfer code. Our models cover a wide range of disc wind geometries and kinematics. Such winds naturally reproduce both BALs and BELs. In general, sightlines looking into the wind cone preferentially produce BALs, while other orientations preferentially produce BELs. We also study the effect of wind clumping and CNO-processed abundances on the observed spectra. Clumpy winds tend to produce stronger UV emission and absorption lines, because clumping increases both the emission measure and the abundances of the relevant ionic species, the latter by reducing the ionization state of the outflow. The main effect of adopting CNO-processed abundances is a weakening of C iv 1550 Å  and an enhancement of N v 1240 Å  in the spectra. We conclude that line formation in an accretion disc wind is a promising mechanism for explaining the diverse UV spectra of TDEs. If this is correct, the relative number of BAL and BEL TDEs can be used to estimate the covering factor of the outflow. The models in this work are publicly available online and upon request.</jats:p

    Flecainide exerts paradoxical effects on sodium currents and atrial arrhythmia in murine RyR2-P2328S hearts.

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    AIMS: Cardiac ryanodine receptor mutations are associated with catecholaminergic polymorphic ventricular tachycardia (CPVT), and some, including RyR2-P2328S, also predispose to atrial fibrillation. Recent work associates reduced atrial Nav 1.5 currents in homozygous RyR2-P2328S (RyR2(S/S) ) mice with slowed conduction and increased arrhythmogenicity. Yet clinically, and in murine models, the Nav 1.5 blocker flecainide reduces ventricular arrhythmogenicity in CPVT. We aimed to determine whether, and how, flecainide influences atrial arrhythmogenicity in RyR2(S/S) mice and their wild-type (WT) littermates. METHODS: We explored effects of 1 μm flecainide on WT and RyR2(S/S) atria. Arrhythmic incidence, action potential (AP) conduction velocity (CV), atrial effective refractory period (AERP) and AP wavelength (λ = CV × AERP) were measured using multi-electrode array recordings in Langendorff-perfused hearts; Na(+) currents (INa ) were recorded using loose patch clamping of superfused atria. RESULTS: RyR2(S/S) showed more frequent atrial arrhythmias, slower CV, reduced INa and unchanged AERP compared to WT. Flecainide was anti-arrhythmic in RyR2(S/S) but pro-arrhythmic in WT. It increased INa in RyR2(S/S) atria, whereas it reduced INa as expected in WT. It increased AERP while sparing CV in RyR2(S/S) , but reduced CV while sparing AERP in WT. Thus, RyR2(S/S) hearts have low λ relative to WT; flecainide then increases λ in RyR2(S/S) but decreases λ in WT. CONCLUSIONS: Flecainide (1 μm) rescues the RyR2-P2328S atrial arrhythmogenic phenotype by restoring compromised INa and λ, changes recently attributed to increased sarcoplasmic reticular Ca(2+) release. This contrasts with the increased arrhythmic incidence and reduced INa and λ with flecainide in WT.This work was supported by the Biotechnology and Biological Sciences Research Council (BBSRC, UK) under a David Phillips Fellowship held by JAF (BB/FO23863/1) and by the Isaac Newton Trust/Wellcome Trust ISSF/University of Cambridge Joint Research Grants Scheme.This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1111/apha.1250

    Ultrahigh energy cosmic rays from shocks in the lobes of powerful radio galaxies

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    The origin of ultrahigh energy cosmic rays (UHECRs) has been an open question for decades. Here, we use a combination of hydrodynamic simulations and general physical arguments to demonstrate that UHECRs can in principle be produced by diffusive shock acceleration (DSA) in shocks in the backflowing material of radio galaxy lobes. These shocks occur after the jet material has passed through the relativistic termination shock. Recently, several authors have demonstrated that highly relativistic shocks are not effective in accelerating UHECRs. The shocks in our proposed model have a range of non-relativistic or mildly relativistic shock velocities more conducive to UHECR acceleration, with shock sizes in the range 1-10 kpc. Approximately 10 per cent of jet's energy flux is focused through a shock in the backflow of M > 3. Although the shock velocities can be low enough that acceleration to high energy via DSA is still efficient, they are also high enough for the Hillas energy to approach 1019-20 eV, particularly for heavier CR composition and in cases where fluid elements pass through multiple shocks. We discuss some of the more general considerations for acceleration of particles to ultrahigh energy with reference to giant-lobed radio galaxies such as Centaurus A and Fornax A, a class of sources which may be responsible for the observed anisotropies from UHECR observatories

    Disturbed families or families disturbed: a reconsideration.

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    BACKGROUND: The relationship between anorexia nervosa (AN) and family disturbance has been a subject of debate since its first description. What began as a clear view of the pathologically disturbed family causing AN has become ever more complex over the decades. OBJECTIVE: The aim of this review is to explore the literature to examine the changes and evolution of clinical opinion around family dysfunction and AN over the last 20 years. METHODS: A narrative review of heterogeneous studies in peer-reviewed publications sourced from the major databases, including PubMed and ScienceDirect, to illuminate the topic of family distress and AN by highlighting the conflicting and complementary ways it has been studied. RESULTS: This review has highlighted the complexity of the relationship between anorectic sufferers and their families. It has explored the literature about parental burden, emotions and cognitive mechanisms together with parental attitudes about weight and shape. It is clear that there is no consistent psycho-social pathology in families which has been shown to be causative. However, over the last twenty years, research has highlighted the distress and family dysfunction caused by having to look after an anoretic child with poor mentalisation skills, insecure attachment and emotion dysregulation. CONCLUSION: The area has become clearer over the last 20 years; research suggests a bi-directional relationship between AN and family dysfunction, with difficult dynamics becoming entrenched within the family. This is best addressed, the consensus suggests, by specialist family therapy and carer skills interventions. Longitudinal research is needed to definitively answer the question with rigorous scientific certainty. EMB RATING: Level V. LEVEL OF EVIDENCE: Level I: Evidence obtained from: at least one properly designed randomized controlled trials; systematic reviews and meta-analyses; experimental studies. Level II: Evidence obtained from well-designed controlled trials without randomization. Level III: Evidence obtained from well-designed cohort or case-control analytic studies. Level IV: Evidence obtained from with multiple time series analysis such as case studies. Dramatic results in uncontrolled trials might also be regarded as this type of evidence. Level V: Opinions of respected authorities, based on descriptive studies, narrative reviews, clinical experience, or reports of expert committees

    Improving Performance Estimation for FPGA-based Accelerators for Convolutional Neural Networks

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    Field-programmable gate array (FPGA) based accelerators are being widely used for acceleration of convolutional neural networks (CNNs) due to their potential in improving the performance and reconfigurability for specific application instances. To determine the optimal configuration of an FPGA-based accelerator, it is necessary to explore the design space and an accurate performance prediction plays an important role during the exploration. This work introduces a novel method for fast and accurate estimation of latency based on a Gaussian process parametrised by an analytic approximation and coupled with runtime data. The experiments conducted on three different CNNs on an FPGA-based accelerator on Intel Arria 10 GX 1150 demonstrated a 30.7% improvement in accuracy with respect to the mean absolute error in comparison to a standard analytic method in leave-one-out cross-validation.Comment: This article is accepted for publication at ARC'202

    Connecting radio emission to AGN wind properties with Broad Absorption Line Quasars

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    Broad Absorption Line Quasars (BALQSOs) show strong signatures of powerful outflows, with the potential to alter the cosmic history of their host galaxies. These signatures are only seen in ∼10% of optically selected quasars, although the fraction significantly increases in IR and radio selected samples. A proven physical explanation for this observed fraction has yet to be found, along with a determination of why this fraction increases at radio wavelengths. We present the largest sample of radio matched BALQSOs using the LOFAR Two-metre Sky Survey Data Release 2 and employ it to investigate radio properties of BALQSOs. Within the DR2 footprint, there are 3537 BALQSOs from Sloan Digital Sky Survey DR12 with continuum signal to noise ≥5. We find radio-detections for 1108 BALQSOs, with an important sub-population of 120 LoBALs, an unprecedented sample size for radio matched BALQSOs given the sky coverage to date. BALQSOs are a radio-quiet population that show an increase of × 1.50 radio-detection fraction compared to non-BALQSOs. LoBALs show an increase of × 2.22 that of non-BALQSO quasars. We show that this detection fraction correlates with wind-strength, reddening and C IV emission properties of BALQSOs and that these features may be connected, although no single property can fully explain the enhanced radio detection fraction. We create composite spectra for sub-classes of BALQSOs based on wind strength and colour, finding differences in the absorption profiles of radio-detected and radio-undetected sources, particularly for LoBALs. Overall, we favour a wind-ISM interaction explanation for the increased radio-detection fraction of BALQSOs

    Do Changes in the Pace of Events Affect One-Off Judgments of Duration?

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    Five experiments examined whether changes in the pace of external events influence people’s judgments of duration. In Experiments 1a–1c, participants heard pieces of music whose tempo accelerated, decelerated, or remained constant. In Experiment 2, participants completed a visuo-motor task in which the rate of stimulus presentation accelerated, decelerated, or remained constant. In Experiment 3, participants completed a reading task in which facts appeared on-screen at accelerating, decelerating, or constant rates. In all experiments, the physical duration of the to-be-judged interval was the same across conditions. We found no significant effects of temporal structure on duration judgments in any of the experiments, either when participants knew that a time estimate would be required (prospective judgments) or when they did not (retrospective judgments). These results provide a starting point for the investigation of how temporal structure affects one-off judgments of duration like those typically made in natural settings

    Self-esteem as a catalyst for change in adolescent inpatients with anorexia nervosa: a pilot randomised controlled trial.

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    PURPOSE: To determine the potential effectiveness of a six-session manualised self-esteem group using CBT approaches when given as an adjuvant to adolescent inpatients with Anorexia Nervosa (AN). METHODS: Using a randomised controlled design, 50 girls aged 12-17 years with AN were assigned to either self-esteem group with treatment as usual (TAU) (n = 25) or TAU alone (n = 25). 50/78 (64%) consented to be randomised. Both groups completed self-report measures of self-esteem and eating disorder psychopathology at three time points to measure the potential effectiveness of the treatment. Qualitative feedback was collected to assess acceptability. RESULTS: 29 participants completed the study: 15 self-esteem group with TAU, 14 TAU alone. Self-esteem group participants had greater improvement in all outcomes than TAU participants at all time points, the difference in self-report self-esteem at T2 is 1.12 (95% CI - 1.44-3.69; effect size = 0.21). Similar small effect sizes were found for the eating disorder psychopathology measure following completion of the intervention but not at four-week follow-up. Favourable qualitative feedback was gained. CONCLUSION: These findings demonstrate that the self-esteem group supplements an intensive treatment package which also addresses elements of low self-esteem. The self-esteem group was beneficial for addressing self-esteem and acted as a catalyst for change in eating disorder psychopathology. Positive qualitative feedback indicated the intervention was acceptable to users. Self-esteem group is a potential new adjuvant treatment for AN. EMB RATING: Level 1
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