58 research outputs found
Nuclear Magnetohydrodynamic EMP, Solar Storms, and Substorms
In addition to a fast electromagnetic pulse (EMP), a high altitude nuclear
burst produces a relatively slow magnetohydrodynarnic EMP (MHD EMP), whose
effects are like those from solar storm geomagnetically induced currents (SS
GIC). The MHD EMP electric field E < 10^-1 V/m and lasts < 10^2 sec, whereas
for solar storms E > 10^-2 V/m and lasts >10^3 sec. Although the solar storm
electric field is lower than MHD EMP, the solar storm effects are generally
greater due to their much longer duration. Substorms produce much smaller
effects than SS GIC, but occur much more frequently. This paper describes the
physics of such geomagnetic disturbances and analyzes their effects.Comment: 29 pages, 14 figures, 5 table
A case study investigating the impact of the London 2012 Olympic and Paralympic Games on participation in two non-traditional English sports, Judo and Fencing.
The hosting of the London 2012 Olympic and Paralympic Games (LOPG)
brought with it detailed legacy plans aiming to âInspire a Generationâ. The idea
that hosting a sports mega-event will encourage the host population to engage in
more physical activity is commonly used by governments to justify the large
investments they make. The aim of this research paper was to investigate the
impact that hosting the 2012 Games had on grass-root sports participation within
the host nation. This paper focuses on two non-traditional English sports, Fencing
and Judo and investigated the changes in mass sports participation. The
membership rate analysis of our sample highlighted an overall increase in participation
between 2007 and 2013, in both Judo and Fencing. The data gathered
from the interviews with the head office staff at the National Governing Bodies
(NGBs) and local club coaches suggested that the grass-root participation programmes
were the most effective way of increasing participation, rather than the
reliance, solely on the inspiration effect from hosting the LOPG itself. The study
highlighted the importance of strengthening communication between local voluntary
clubs and the NGB, to ensure sports could promote themselves and capitalise
on this global sporting phenomenon, which provided unprecedented media
coverage and opportunities for these non-traditional sports. This case study provides
initial results relating to the effect that a major international multi-sport
event can have in the development of non-traditional sports in the host population,
in terms of membership variations, participation programmes and organisational
dynamics
Quality of the Physical Education Teacher's Instruction in the Perspective of Self-Determination.
The teacher's instructions in physical education class have important implications for the psychological well-being of their students. The aim of this study was to analyze, under the postulates of the Self-Determination Theory (SDT), a model with the following sequence: the perception of the quality of the instructions (task presentation, amount of corrective feedback, and its legitimate perception) generated by the physical education teacher, the satisfaction of the three basic psychological needs and the subjective vitality in young students. The participants were 890 students (462 males and 428 females) of primary level from the metropolitan area of Monterrey, Mexico, between ages 11 and 13 (M = 11.36; SD = 0.49). The structural equation modeling showed positive and significant associations in all model interrelations, that is, task presentation and the amount of corrective feedback (B = 0.88, p < 0.001), and this in turn with legitimate perception (B = 0.81, p < 0.001); the legitimate perception of feedback and the satisfaction of the need for autonomy, competence, and relatedness (B = 0.63, p < 0.001; B = 0.90, p < 0.001; B = 1.01, p < 0.001, respectively); finally, the satisfaction of the three psychological needs and the subjective vitality (B = 0.12, p < 0.01; B = 0.43, p < 0.001; B = 0.24, p < 0.001, respectively). Therefore, the importance of a quality task presentation, as well as providing corrective feedback based on support for autonomy, is evident, so that students perceive it legitimately and thus facilitate the satisfaction of their basic psychological needs and in consequence, indicators of psychological well-being such as subjective vitality
The organisational performance of National Disability Sport Organisations during a time of austerity: A resource dependence theory perspective
Austerity measures implemented by the UK Coalition government have had a negative impact on disabled people (Cross 2013). This article utilises the resource dependence theory to explore the challenges national disability sport organisations (NDSOs) have faced in their attempts to achieve growth, whilst discussing some of the tactics used to overcome these challenges. Secondary quantitative data from the 2011-2015 NDSO accounts was analysed, which suggests increased income has been accompanied by increased cost, with fluctuations between surpluses and deficits across the financial years. Funding from Sport England, the government body for grassroots sport in England, was either awarded for the first time or increased. Nine in-depth interviews were conducted with senior managers from seven NDSOs, the English Federation of Disability Sport, and Sport England. It was found austerity presented challenges for the NDSOs in accessing charitable grants and funding, and that some disabled people were fearful of losing their disability benefits if they were seen to be active. The management of relationships with national governing bodies and county sport partnerships was also a challenge. The formation of alliances, the building up of financial reserves, and the generation of knowledge, have been some of the tactics used by the NDSOs in the management of their resources. This research highlights how some NDSOs have achieved growth amid an uncertain economic backdrop, and how these organisations have managed their scarce resources
Systematic, early rhythm control strategy for atrial fibrillation in patients with or without symptoms:the EAST-AFNET 4 trial
AIMS: Clinical practice guidelines restrict rhythm control therapy to patients with symptomatic atrial fibrillation (AF). The EAST-AFNET 4 trial demonstrated that early, systematic rhythm control improves clinical outcomes compared to symptom-directed rhythm control. METHODS AND RESULTS: This prespecified EAST-AFNET 4 analysis compared the effect of early rhythm control therapy in asymptomatic patients (EHRA score I) to symptomatic patients. Primary outcome was a composite of death from cardiovascular causes, stroke, or hospitalization with worsening of heart failure or acute coronary syndrome, analyzed in a time-to-event analysis. At baseline, 801/2633 (30.4%) patients were asymptomatic [mean age 71.3 years, 37.5% women, mean CHA(2)DS(2)-VASc score 3.4, 169/801 (21.1%) heart failure]. Asymptomatic patients randomized to early rhythm control (395/801) received similar rhythm control therapies compared to symptomatic patients [e.g. AF ablation at 24 months: 75/395 (19.0%) in asymptomatic; 176/910 (19.3%) symptomatic patients, P = 0.672]. Anticoagulation and treatment of concomitant cardiovascular conditions was not different between symptomatic and asymptomatic patients. The primary outcome occurred in 79/395 asymptomatic patients randomized to early rhythm control and in 97/406 patients randomized to usual care (hazard ratio 0.76, 95% confidence interval [0.6; 1.03]), almost identical to symptomatic patients. At 24 months follow-up, change in symptom status was not different between randomized groups (P = 0.19). CONCLUSION: The clinical benefit of early, systematic rhythm control was not different between asymptomatic and symptomatic patients in EAST-AFNET 4. These results call for a shared decision discussing the benefits of rhythm control therapy in all patients with recently diagnosed AF and concomitant cardiovascular conditions (EAST-AFNET 4; ISRCTN04708680; NCT01288352; EudraCT2010-021258-20)
Changes in quality of life, cognition and functional status following catheter ablation of atrial fibrillation
Objective To investigate changes in quality of life (QoL), cognition and functional status according to arrhythmia recurrence after atrial fibrillation (AF) ablation. Methods We compared QoL, cognition and functional status in patients with recurrent atrial tachycardia (AT)/AF versus those without recurrent AT/AF in the AXAFA-AFNET 5 clinical trial. We also sought to identify factors associated with improvement in QoL and functional status following AF ablation by overall change scores with and without analysis of covariance (ANCOVA). Results Among 518 patients who underwent AF ablation, 154 (29.7%) experienced recurrent AT/AF at 3 months. Patients with recurrent AT/AF had higher mean CHA(2)DS(2)-VASc scores (2.8 vs 2.3, p Conclusions Patients without recurrent AT/AF appear to experience greater improvement in functional status but similar QoL as those with recurrent AT/AF after AF ablation
The Role of Voluntary Sport Organisations in Leveraging the London 2012 Sport Participation Legacy
This study aimed to understand the perceptions of national Voluntary Sport Organisations (VSOs) managers towards a mega sports event and identify the components they felt enhanced or inhibited their organisations capacity to implement a sport participation legacy. London 2012 was the first Olympic Games to explicitly attempt to deliver this type of legacy, and an exploratory, online mixed-method survey examined the perceptions of 105 senior managers from 37 VSOs, post-event. Principal Component Analysis identified four distinct factors: âobjectives, standards & resourcesâ, âevent capitalisation & opportunitiesâ, âmonitoring & evaluationâ and âclub engagement & implementationâ, explaining 51.5% of the variance. Also, relevant organisational characteristics such as sport type, funding and sport size were examined to investigate the influence this had on their capacity. From these findings, the main recommendations are that future mega sport event hosts should: 1) Engage and consult with multiple stakeholders to engender sustained sport participation. 2) Set clear and monitorable objectives. 3) Establish funding and support mechanisms relevant to each sport. 4) Engage non-competing sports in the leveraging process. 5) Finally, event organisers should try to ensure personnel consistency
Ablation Versus Amiodarone for Treatment of Persistent Atrial Fibrillation in Patients With Congestive Heart Failure and an Implanted Device: Results From the AATAC Multicenter Randomized Trial
Background - Whether catheter ablation (CA) is superior to amiodarone (AMIO) for the treatment of persistent atrial fibrillation (AF) in patients with heart failure is unknown. Methods and Results - This was an open-label, randomized, parallel-group, multicenter study. Patients with persistent AF, dual-chamber implantable cardioverter defibrillator or cardiac resynchronization therapy defibrillator, New York Heart Association II to III, and left ventricular ejection fraction <40% within the past 6 months were randomly assigned (1:1 ratio) to undergo CA for AF (group 1, n=102) or receive AMIO (group 2, n=101). Recurrence of AF was the primary end point. All-cause mortality and unplanned hospitalization were the secondary end points. Patients were followed up for a minimum of 24 months. At the end of follow-up, 71 (70%; 95% confidence interval, 60%-78%) patients in group 1 were recurrence free after an average of 1.4\uc2\ub10.6 procedures in comparison with 34 (34%; 95% confidence interval, 25%-44%) in group 2 (log-rank P<0.001). The success rate of CA in the different centers after a single procedure ranged from 29% to 61%. After adjusting for covariates in the multivariable model, AMIO therapy was found to be significantly more likely to fail (hazard ratio, 2.5; 95% confidence interval, 1.5-4.3; P<0.001) than CA. Over the 2-year follow-up, the unplanned hospitalization rate was (32 [31%] in group 1 and 58 [57%] in group 2; P<0.001), showing 45% relative risk reduction (relative risk, 0.55; 95% confidence interval, 0.39-0.76). A significantly lower mortality was observed in CA (8 [8%] versus AMIO (18 [18%]; P=0.037). Conclusions - This multicenter randomized study shows that CA of AF is superior to AMIO in achieving freedom from AF at long-term follow-up and reducing unplanned hospitalization and mortality in patients with heart failure and persistent AF
Reply: A Prima Vista Ablation of Ventricular Tachycardia: Should We Abandon the Mapping of VT?
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