4,885 research outputs found
Organisational downsizing, sickness absence, and mortality: 10-town prospective cohort study
Objective To examine whether downsizing, the reduction of personnel in organisations, is a predictor of increased sickness absence and mortality among employees.Design Prospective cohort study over 7.5 years of employees grouped into categories on the basis of reductions of personnel in their occupation and workplace: no downsizing ( 18%).Setting Four towns in Finland.Participants 5909 male and 16 521 female municipal employees, aged 19-62 years, who kept their jobs.Main outcome measures Annual sickness absence rate based on employers' records before and after downsizing by employment contract; all cause and cause specific mortality obtained from the national mortality register.Results Major downsizing was associated with an increase in sickness absence (P for trend < 0.001) in permanent employees but not in temporary employees. The extent of downsizing was also associated with cardiovascular deaths (P for trend < 0.01) but not with deaths from other causes. Cardiovascular mortality was 2.0 (95% confidence interval 1.0 to 3.9) times higher after major downsizing than after no downsizing. Splitting the follow up period into two halves showed a 5.1 (1.4 to 19.3) times increase in cardiovascular mortality for major downsizing during the first four years after downsizing. The corresponding hazard ratio was 1.4 (0.6 to 3.1) during the second half of follow up.Conclusion Organisational downsizing may increase sickness absence and the risk of death from cardiovascular disease in employees who keep their jobs
Stochastic Particle Acceleration in Parallel Relativistic Shocks
We present results of test-particle simulations on both the first- and the
second-order Fermi acceleration for relativistic parallel shock waves. Our
studies suggest that the role of the second-order mechanism in the turbulent
downstream of a relativistic shock may have been underestimated in the past,
and that the stochastic mechanism may have significant effects on the form of
the particle spectra and its time evolution.Comment: Poster at "The XXII Texas Symposium on Relativistic Astrophysics",
Stanford, USA, December 2004, (TSRA04), 6 pages, LaTeX, 5 ps/eps figure
Microflaring of a solar Bright point
A solar X-ray Bright point (BP) was observed with the SUMER-spectrograph of
the SOHO-observatory. The data consist of four far-UV spectral lines formed
between 2 10^4 - 6 10^5 K, with 2 arcsec spatial, 2.8 min temporal and 4 km/s
spectral resolution. A striking feature is the strong microflaring and
appearance of several short lived transients. Using simultaneous magnetic field
measurements the region observed seemed to lie above a cancelling flux region.
With respect to the filling factor and emission measure this particular BP was
similar to the average surface of a moderately active solar type star.Comment: 7 pages, 6 figures, in press Astronomy and Astrophysics; for Fig.3 it
is recommended to download separately the colour version h3653f3.pd
Stochastic Acceleration in Relativistic Parallel Shocks
(abridged) We present results of test-particle simulations on both the first
and the second order Fermi acceleration at relativistic parallel shock waves.
We consider two scenarios for particle injection: (i) particles injected at the
shock front, then accelerated at the shock by the first order mechanism and
subsequently by the stochastic process in the downstream region; and (ii)
particles injected uniformly throughout the downstream region to the stochastic
process. We show that regardless of the injection scenario, depending on the
magnetic field strength, plasma composition, and the employed turbulence model,
the stochastic mechanism can have considerable effects on the particle spectrum
on temporal and spatial scales too short to be resolved in extragalactic jets.
Stochastic acceleration is shown to be able to produce spectra that are
significantly flatter than the limiting case of particle energy spectral index
-1 of the first order mechanism. Our study also reveals a possibility of
re-acceleration of the stochastically accelerated spectrum at the shock, as
particles at high energies become more and more mobile as their mean free path
increases with energy. Our findings suggest that the role of the second order
mechanism in the turbulent downstream of a relativistic shock with respect to
the first order mechanism at the shock front has been underestimated in the
past, and that the second order mechanism may have significant effects on the
form of the particle spectra and its evolution.Comment: 14 pages, 11 figures (9 black/white and 2 color postscripts). To be
published in the ApJ (accepted 6 Nov 2004
Artists and Society in Modern Tibetan Literature
Peer reviewe
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