Work ability meetings-a survey of Finnish occupational physicians

Background Work ability meetings (WAMs) are planned discussions between an employee, a manager and an occupational physician (OP) to support work ability and return to work (RTW). During the last decade, WAMs become a popular intervention in Finnish occupational healthcare, although research on their content is lacking. Aims To describe the practice of WAMs in Finland. Methods We sent an internet survey by e-mail to members of the Finnish Society of Occupational Health Physicians in August 2014. We asked them to describe the last WAM they had attended, the employee the meeting concerned, the reason why it was convened, the content of the meeting and the action plan developed. Results A total of 303 of 1304 OPs responded (24%) to the survey. The meetings were most often arranged for employees in manual or clerical work (71%). There were several overlapping reasons for convening a WAM, including a worker's reduced work ability (57%), functional ability (42%) or long-term sickness absence (38%). The meetings consisted of RTW planning, clarification of the situation and a dialogue between the three parties. In half of the cases, the action plans dealt with modifications of work tasks. A third of cases were forwarded to vocational rehabilitation, while permanent disability pension was considered in 6% of cases. Conclusions The focus of WAMs was on workplace adjustments to support workers to remain at work. The WAMs dealt mostly with early interventions for RTW: work modifications, adjustments and vocational rehabilitation.Peer reviewe

Reaction, Levy Flights, and Quenched Disorder

We consider the A + A --> emptyset reaction, where the transport of the particles is given by Levy flights in a quenched random potential. With a common literature model of the disorder, the random potential can only increase the rate of reaction. With a model of the disorder that obeys detailed balance, however, the rate of reaction initially increases and then decreases as a function of the disorder strength. The physical behavior obtained with this second model is in accord with that for reactive turbulent flow, indicating that Levy flight statistics can model aspects of turbulent fluid transport.Comment: 6 pages, 5 pages. Phys. Rev. E. 65 (2002) 011109--1-

Effects of turbulent mixing on critical behaviour in the presence of compressibility: Renormalization group analysis of two models

Critical behaviour of two systems, subjected to the turbulent mixing, is studied by means of the field theoretic renormalization group. The first system, described by the equilibrium model A, corresponds to relaxational dynamics of a non-conserved order parameter. The second one is the strongly non-equilibrium reaction-diffusion system, known as Gribov process and equivalent to the Reggeon field theory. The turbulent mixing is modelled by the Kazantsev-Kraichnan "rapid-change" ensemble: time-decorrelated Gaussian velocity field with the power-like spectrum k^{-d-\xi}. Effects of compressibility of the fluid are studied. It is shown that, depending on the relation between the exponent \xi and the spatial dimension d, the both systems exhibit four different types of critical behaviour, associated with four possible fixed points of the renormalization group equations. The most interesting point corresponds to a new type of critical behaviour, in which the nonlinearity and turbulent mixing are both relevant, and the critical exponents depend on d, \xi and the degree of compressibility. For the both models, compressibility enhances the role of the nonlinear terms in the dynamical equations: the region in the d-\xi plane, where the new nontrivial regime is stable, is getting much wider as the degree of compressibility increases. In its turn, turbulent transfer becomes more efficient due to combined effects of the mixing and the nonlinear terms.Comment: 25 pages, 4 figure

An improved \eps expansion for three-dimensional turbulence: summation of nearest dimensional singularities

An improved \eps expansion in the $d$-dimensional ($d > 2$) stochastic theory of turbulence is constructed by taking into account pole singularities at $d \to 2$ in coefficients of the \eps expansion of universal quantities. Effectiveness of the method is illustrated by a two-loop calculation of the Kolmogorov constant in three dimensions.Comment: 4 page

An improved \eps expansion for three-dimensional turbulence: two-loop renormalization near two dimensions

An improved \eps expansion in the $d$-dimensional ($d > 2$) stochastic theory of turbulence is constructed at two-loop order which incorporates the effect of pole singularities at $d \to 2$ in coefficients of the \eps expansion of universal quantities. For a proper account of the effect of these singularities two different approaches to the renormalization of the powerlike correlation function of the random force are analyzed near two dimensions. By direct calculation it is shown that the approach based on the mere renormalization of the nonlocal correlation function leads to contradictions at two-loop order. On the other hand, a two-loop calculation in the renormalization scheme with the addition to the force correlation function of a local term to be renormalized instead of the nonlocal one yields consistent results in accordance with the UV renormalization theory. The latter renormalization prescription is used for the two-loop renormalization-group analysis amended with partial resummation of the pole singularities near two dimensions leading to a significant improvement of the agreement with experimental results for the Kolmogorov constant.Comment: 23 pages, 2 figure

Anomalous scaling of a passive scalar advected by the Navier--Stokes velocity field: Two-loop approximation

The field theoretic renormalization group and operator product expansion are applied to the model of a passive scalar quantity advected by a non-Gaussian velocity field with finite correlation time. The velocity is governed by the Navier--Stokes equation, subject to an external random stirring force with the correlation function $\propto \delta(t-t') k^{4-d-2\epsilon}$. It is shown that the scalar field is intermittent already for small $\epsilon$, its structure functions display anomalous scaling behavior, and the corresponding exponents can be systematically calculated as series in $\epsilon$. The practical calculation is accomplished to order $\epsilon^{2}$ (two-loop approximation), including anisotropic sectors. Like for the well-known Kraichnan's rapid-change model, the anomalous scaling results from the existence in the model of composite fields (operators) with negative scaling dimensions, identified with the anomalous exponents. Thus the mechanism of the origin of anomalous scaling appears similar for the Gaussian model with zero correlation time and non-Gaussian model with finite correlation time. It should be emphasized that, in contrast to Gaussian velocity ensembles with finite correlation time, the model and the perturbation theory discussed here are manifestly Galilean covariant. The relevance of these results for the real passive advection, comparison with the Gaussian models and experiments are briefly discussed.Comment: 25 pages, 1 figur