Operator ordering and causality

It is shown that causality violations [M. de Haan, Physica 132A, 375, 397 (1985)], emerging when the conventional definition of the time-normal operator ordering [P.L.Kelley and W.H.Kleiner, Phys.Rev. 136, A316 (1964)] is taken outside the rotating wave approximation, disappear when the amended definition [L.P. and S.S., Annals of Physics, 323, 1989 (2008)] of this ordering is used.Comment: References update

Trajectories of self-rated health before and after retirement: evidence from two cohort studies

OBJECTIVES: Previous studies have produced conflicting findings on the health consequences of retirement. We aimed at identifying trajectories of self-rated health over retirement transition using repeated measurements and examined which preretirement factors predicted membership to each trajectory. METHODS: The study population consisted of Finnish public sector employees from two independent cohorts (Finnish Public Sector Study (FPS), n=5776 with a 4-year follow-up interval; and Finnish Retirement and Aging Study (FIREA), n=2796 with a 1-year follow-up interval). Both cohorts included assessment of self-rated health one to three times before and one to three times after retirement (average number of measurement points: 3.7 in FPS and 3.5 in FIREA). We used latent trajectory analysis to identify trajectories of self-rated health. RESULTS: In both cohorts four similar trajectories were identified: 'Sustained good health' (47% in FPS and 74% in FIREA), 'From good to suboptimal health' (19% and 6%), 'From suboptimal to good health' (14% and 8%) and 'Sustained suboptimal health' (20% and 12%). There were more women and persons in high occupational status in the 'From suboptimal to good health' trajectory group when compared with 'Sustained suboptimal health' trajectory group in FPS. Those in the trajectory 'From good to suboptimal health' had lower occupational status and higher job strain in comparison with those in the 'Sustained good health' trajectory in both cohorts. CONCLUSIONS: A large majority of public sector employees maintain their perceived health status during retirement transition. Adverse trajectory in self-rated health relate to low occupational status and work-related stressors

Gauss sum factorization with cold atoms

We report the first implementation of a Gauss sum factorization algorithm by an internal state Ramsey interferometer using cold atoms. A sequence of appropriately designed light pulses interacts with an ensemble of cold rubidium atoms. The final population in the involved atomic levels determines a Gauss sum. With this technique we factor the number N=263193.Comment: 4 pages, 5 figure

Diet quality as a predictor of cardiometabolic disease-free life expectancy: the Whitehall II cohort study

Background: Poor diet quality has been linked to increased risk of many chronic diseases and premature mortality. Less research has considered dietary habits in relation to disease-free life expectancy. Objectives: Our objective was to investigate the association of diet quality with cardiometabolic disease–free life expectancy between ages 50 and 85 y. Methods: Diet quality of 8041 participants of the Whitehall II cohort study was assessed with the Alternative Healthy Eating Index 2010 (AHEI-2010) in 1991–1994, 1997–1999, and 2002–2004. The measurement of diet quality closest to age 50 for each participant was used. We utilized repeat measures of cardiometabolic disease (coronary heart disease, stroke, and type 2 diabetes) from the first observation when participants were aged ≥50 y. Multistate life table models with covariates age, gender, occupational position, smoking, physical activity, and alcohol consumption were used to estimate total and sex-specific cardiometabolic disease–free life expectancy from age 50 to 85 y for each AHEI-2010 quintile, where the lowest quintile represents unhealthiest dietary habits and the highest quintile the healthiest habits. Results: The number of cardiometabolic disease–free life-years after age 50 was 23.9 y (95% CI: 23.0, 24.9 y) for participants with the healthiest diet, that is, a higher score on the AHEI-2010, and 21.4 y (95% CI: 20.6, 22.3 y) for participants with the unhealthiest diet. The association between diet quality and cardiometabolic disease–free life expectancy followed a dose–response pattern and was observed in subgroups of participants of different occupational position, BMI, physical activity level, and smoking habit, as well as when participants without cardiometabolic disease at baseline were excluded from analyses. Conclusions: Healthier dietary habits are associated with cardiometabolic disease–free life expectancy between ages 50 and 85

Change in Job Strain as a Predictor of Change in Insomnia Symptoms: Analyzing Observational Data as a Non-randomized Pseudo-Trial

Study objectives: To examine whether change in job strain leads to change in insomnia symptoms. Methods: Among 24873 adults (82% women, mean age 44 years) who participated in a minimum of three consecutive study waves (2000–2012), job strain was assessed at the first and second wave and insomnia symptoms at all three waves. We analyzed observational data as a “pseudo-trial” including participants with no job strain in the first wave and no insomnia symptoms in the first and second wave (n = 7354) to examine whether the onset of job strain between the first and second waves predicted the onset of insomnia symptoms in the third wave. We used a corresponding approach, including those with job strain in the first wave and insomnia symptoms in the first and second wave (n = 2332), to examine whether the disappearance of job strain between the first two waves predicted remission of insomnia symptoms in the third wave. Results: The onset of job strain predicted the onset of subsequent insomnia symptoms after adjustment for sex, age, marital status, education, smoking, physical activity, alcohol consumption, body mass index, and comorbidities (odds ratio compared to no onset of job strain 1.32, 95% CI 1.16–1.51). The disappearance of job strain was associated with lower odds of repeated insomnia symptoms (odds ratio compared to no disappearance of job strain 0.78, 95% CI 0.65–0.94). Further adjustment for shift work or sleep apnea did not change these associations. Conclusions: These results suggest that job strain is a modifiable risk factor for insomnia symptoms

Social relationships as predictors of extended employment beyond the pensionable age: a cohort study

The aim is to examine whether characteristics of social relationships predict extended employment beyond the pensionable age among Finnish public sector workers. The study population consisted of 4014 participants (83% women, age 62.56 ± 1.21) of the Finnish Retirement and Aging Study followed between 2014 and 2019. Extended employment was defined as the difference between actual retirement date and individual age-related pensionable date and classified into three groups: no extension (retired on pensionable age or extended by < 3 months), short extension (3 months–< 1 year), and long extension (≥ 1 year) beyond the pensionable date. Characteristics of social relationships and engagement were assessed 18 months prior to the pensionable date. Social engagement was classified into consumptive social participation, formal social participation, informal social participation, and other social participation. Data were analyzed using multinomial regression analysis. Of total study participants, 17.8% belonged to short- and 16.5% belonged to long-extension group. Adjusted for age, occupational status, self-rated health and depression, and having a working spouse (OR 2.34, 95% CI 1.39–3.95) were associated with long extension of employment beyond the pensionable age when compared to no extension among men. Likewise, among women, living alone (OR 1.60, 95% CI 1.28–2.00), having a working spouse (1.85, 1.39–2.45), and high consumptive (1.32, 1.07–1.65), high formal (1.47, 1.17–1.85), and other social participation (0.79, 0.63–0.98) were associated with long extension. Having a working spouse, living alone, and high consumptive social participation were associated with short extension. Several characteristics of social relationships, such as having a working spouse, living alone, and high frequency of social engagement, predicted an extension of employment beyond the pensionable age

Effective-action approach to a trapped Bose gas

The effective-action formalism is applied to a gas of bosons. The equations describing the condensate and the excitations are obtained using the loop expansion for the effective action. For a homogeneous gas the Beliaev expansion in terms of the diluteness parameter is identified in terms of the loop expansion. The loop expansion and the limits of validity of the well-known Bogoliubov and Popov equations are examined analytically for a homogeneous dilute Bose gas and numerically for a gas trapped in a harmonic-oscillator potential. The expansion to one-loop order, and hence the Bogoliubov equation, is shown to be valid for the zero-temperature trapped gas as long as the characteristic length of the trapping potential exceeds the s-wave scattering length.Comment: 17 pages, 10 figures, accepted for publication in Phys. Rev.

Changes in physical activity by context and residential greenness among recent retirees : Longitudinal GPS and accelerometer study

This study examined the changes in accelerometer-measured physical activity by GPS-measured contexts among Finnish retirees (n = 45 (537 measurement days)) participating in a physical activity intervention. We also assessed whether residential greenness, measured with Normalized Difference Vegetation Index, moderated the changes. Moderate-to-vigorous physical activity (MVPA) increased at home by 7 min/day, (P < 0.001) and during active travel by 5 min/day (P = 0.03). The participants with the highest vs. lowest greenness had 25 min/ day greater increase in MVPA over the follow-up (P for Time*Greenness interaction = 0.04). In conclusion, retirees participating in the intervention increased their MVPA both at home and in active travel, and more so if they lived in a greener area.Peer reviewe