A Simple Grand Unified Relation between Neutrino Mixing and Quark Mixing

It is proposed that all flavor mixing is caused by the mixing of the three quark and lepton families with vectorlike fermions in 5 + 5-bar multiplets of SU(5). This simple assumption implies that both V_{CKM} and U_{MNS} are generated by a single matrix. The entire 3-by-3 complex mass matrix of the neutrinos M_{nu} is then found to have a simple expression in terms of two complex parameters and an overall scale. Thus, all the presently unknown neutrino parameters are predicted. The best fits are for theta_{atm} less than or approximately 40 degrees. The leptonic Dirac CP phase is found to be somewhat greater than pi radians.Comment: 10 pages, 4 figures, one table. Typos correcte

Cost-effectiveness of an outpatient cardiac rehabilitation programme for patients after myocardial infarction and coronary angioplasty

published_or_final_versio

Risks for heart disease and lung cancer from passive smoking by workers in the catering industry

Workers in the catering industry are at greater risk of exposure to secondhand smoke (SHS) when smoke-free workplace policies are not in force. We determined the exposure of catering workers to SHS in Hong Kong and their risk of death from heart disease and lung cancer. Nonsmoking catering workers were provided with screening at their workplaces and at a central clinic. Participants reported workplace, home, and leisure time exposure to SHS. Urinary cotinine was estimated by enzyme immunoassay. Catering facilities were classified into three types: nonsmoking, partially restricted smoking (with nonsmoking areas), and unrestricted smoking. Mean urinary cotinine levels ranged from 3.3 ng/ml in a control group of 16 university staff through 6.4 ng/ml (nonsmoking), 6.1 ng/ml (partially restricted), and 15.9 ng/ml (unrestricted smoking) in 104 workers who had no exposures outside of work. Workers in nonsmoking facilities had exposures to other smoking staff. We modeled workers' mortality risks using average cotinine levels, estimates of workplace respirable particulates, risk data for cancer and heart disease from cohort studies, and national (US) and regional (Hong Kong) mortality for heart disease and lung cancer. We estimated that deaths in the Hong Kong catering workforce of 200,000 occur at the rate of 150 per year for a 40-year working-lifetime exposure to SHS. When compared with the current outdoor air quality standards for particulates in Hong Kong, 30% of workers exceeded the 24-h and 98% exceeded the annual air quality objectives due to workplace SHS exposures. © 2006 Oxford University Press.postprin

Risk factors for race-day fatality in flat racing Thoroughbreds in Great Britain (2000 to 2013)

A key focus of the racing industry is to reduce the number of race-day events where horses die suddenly or are euthanased due to catastrophic injury. The objective of this study was therefore to determine risk factors for race-day fatalities in Thoroughbred racehorses, using a cohort of all horses participating in flat racing in Great Britain between 2000 and 2013. Horse-, race- and course-level data were collected and combined with all race-day fatalities, recorded by racecourse veterinarians in a central database. Associations between exposure variables and fatality were assessed using logistic regression analyses for (1) all starts in the dataset and (2) starts made on turf surfaces only. There were 806,764 starts in total, of which 548,571 were on turf surfaces. A total of 610 fatalities were recorded; 377 (61.8%) on turf. In both regression models, increased firmness of the going, increasing racing distance, increasing average horse performance, first year of racing and wearing eye cover for the first time all increased the odds of fatality. Generally, the odds of fatality also increased with increasing horse age whereas increasing number of previous starts reduced fatality odds. In the ‘all starts’ model, horses racing in an auction race were at 1.46 (95% confidence interval (CI) 1.06–2.01) times the odds of fatality compared with horses not racing in this race type. In the turf starts model, horses racing in Group 1 races were at 3.19 (95% CI 1.71–5.93) times the odds of fatality compared with horses not racing in this race type. Identification of novel risk factors including wearing eye cover and race type will help to inform strategies to further reduce the rate of fatality in flat racing horses, enhancing horse and jockey welfare and safety

Dementia Trends: Impact of the Ageing Population and Societal Implications for Hong Kong

published_or_final_versio

Normative data and psychometric properties of the Connor–Davidson Resilience Scale (CD-RISC) and the abbreviated version (CD-RISC2) among the general population in Hong Kong

postprin

Geometric phase outside a Schwarzschild black hole and the Hawking effect

We study the Hawking effect in terms of the geometric phase acquired by a two-level atom as a result of coupling to vacuum fluctuations outside a Schwarzschild black hole in a gedanken experiment. We treat the atom in interaction with a bath of fluctuating quantized massless scalar fields as an open quantum system, whose dynamics is governed by a master equation obtained by tracing over the field degrees of freedom. The nonunitary effects of this system are examined by analyzing the geometric phase for the Boulware, Unruh and Hartle-Hawking vacua respectively. We find, for all the three cases, that the geometric phase of the atom turns out to be affected by the space-time curvature which backscatters the vacuum field modes. In both the Unruh and Hartle-Hawking vacua, the geometric phase exhibits similar behaviors as if there were thermal radiation at the Hawking temperature from the black hole. So, a measurement of the change of the geometric phase as opposed to that in a flat space-time can in principle reveal the existence of the Hawking radiation.Comment: 14 pages, no figures, a typo in the References corrected, version to appear in JHEP. arXiv admin note: text overlap with arXiv:1109.033

Trends of Disease Burden Consequent to Stroke in Older Persons in Hong Kong: Implications of Population Ageing

published_or_final_versio

The economic burden of influenza-associated outpatient visits and hospitalizations in China: a retrospective survey

published_or_final_versio