Construct validity of the French version of the PRWE (Patient Rated Wrist Evaluation) with the French version of the DASH (Disabilities Arm Shoulder and Hand) is good to very good in a population of patients with wrist injuries in an inpatient rehabilitation unit

Objective.- The Patient-Rated Wrist Evaluation is a specific questionnaire for the wrist [1]. It consists of 15 questions with a total score of 100. It was recently translated into French [2]. However, its validity has not been tested in this language. The Disabilities Arm Shoulder and Hand (DASH), with well-established psychometric properties, is considered as the reference questionnaire for the evaluation of upper extremities. The objective of this study is to measure the construct validity of the PRWE-F with the DASH-F in patients with wrist pathology.Patients and methods.- Fifty-one patients (40 m, 11 w, mean age 42 years), 25 fractures of the radius and 26 lesions of the carpus.Questionnaires PRWE-F and DASH-F at entry and at discharge (0 to 100). Calculation of the construct validity of the PRWE-F comparing with the DASH-F with Pearson correlation coefficients (r) at entry and at discharge. Level of significance (alpha) was set at 5%.Results.- Correlation DASH/PRWE at entry: r = 0.799 (95% CI 0.671 to 0.881), P < 0.0001. Correlation DASH/PRWE at discharge: r = 0.847 (95% CI: 0.745 to 0.910), P < 0.0001.Discussion.- The construct validity of the two instruments indicates that they measure the same concept. Our correlation between DASH-F and PRWE-F, going from 0.799 to 0.847, are comparable to those published in different languages (0.71 to 0.84) [3,4]. The questionnaires PRWE-F can thus be used in rehabilitation patients presenting with wrist pathologies; it is comparable to the DASH but described by MacDermid [1] to be more specific. Compared to the DASH it has the advantage of consisting of two dimensions. Its construct validity is excellent. This questionnaire should be evaluated in other populations, and it should be compared with hand questionnaires more specific than the DASH.

Recommendations to reduce hand exposure for standard nuclear medicine procedures

The optimization of the extremity dosimetry of medical staff in nuclear medicine was the aim of the Work Package 4 (WP4) of the ORAMED project, a Collaborative Project (2008-2011) supported by the European Commission within its 7th Framework Programme. Hand doses and dose distributions across the hands of medical staff working in nuclear medicine departments were evaluated through an extensive measurement program involving 32 hospitals in Europe and 139 monitored workers. The study included the most frequently used radionuclides, (99m)Tc- and (18)F-labelled radiopharmaceuticals for diagnostic and (90)Y-labelled Zevalin (R) and DOTATOC for therapy. Furthermore, Monte Carlo simulations were performed in different predefined scenarios to evaluate separately the efficacy of different radiation protection measures by comparing hand dose distributions according to various parameters. The present work gives recommendations based on results obtained with both measurements and simulations. This results in nine practical recommendations regarding the positioning of the dosemeters for an appropriate skin dose monitoring and the best protection means to reduce the personnel exposure.

A tennis player with hand claudication.

The case of a professional tennis player presenting exercise-induced hand pain with late appearance of digital blanching is reported. A bilateral hypothenar hammer syndrome and stenosis of the common palmar digital arteries close to the head of the metacarpals where the racket handle exerts its maximal force was observed with arteriography. As the patient decided to stop tennis practice, the condition improved without any medication. Six months after stopping tennis he was symptom free. Three conclusions can be drawn from this case report: 1) arteries of both hands can be injured by intense tennis practice, 2) pain in the dominant hand during tennis practice can be due to arterial insufficiency even in the absence of digital blanching which is a sign of severity, 3) hypothenar hammer syndrome is the main cause but stenosis of the common palmar digital arteries can possibly contribute to the ischemic phenomenon. Early recognition is important to avoid ineffective treatment and permanent symptoms. Therefore, we recommend an arterial examination in tennis players suffering from exercise-induced hand pain even in the absence of digital blanching which can be only a late manifestation.

Higher-order colored-noise effects in multivariable systems

We extend the partial resummation technique of Fokker-Planck terms for multivariable stochastic differential equations with colored noise. As an example, a model system of a Brownian particle with colored noise is studied. We prove that the asymmetric behavior found in analog simulations is due to higher-order terms which are left out in that technique. On the contrary, the systematic ¿-expansion approach can explain the analog results.

Escape over a potential barrier driven by colored noise: Large but finite correlation times

The recent theory of Tsironis and Grigolini for the mean first-passage time from one metastable state to another of a bistable potential for long correlation times of the noise is extended to large but finite correlation times.

Passage times for the decay of an unstable state triggered by colored noise

We study the decay of an unstable state in the presence of colored noise by calculating the moment generating function of the passage-time distribution. The problems of the independence of the initial condition in this non-Markovian process and that of nonlinear effects are addressed. Our results are compared with recent analog simulations.

Transient and preparation colored-noise effects: The nonlinear relaxation-time approach

We develop a singular perturbation approach to the problem of the calculation of a characteristic time (the nonlinear relaxation time) for non-Markovian processes driven by Gaussian colored noise with small correlation time. Transient and initial preparation effects are discussed and explicit results for prototype situations are obtained. New effects on the relaxation of unstable states are predicted. The approach is compared with previous techniques.

First-passage time in a bistable potential with colored noise

A precise digital simulation of a bistable system under the effect of colored noise is carried out. A set of data for the mean first-passage time is obtained. The results are interpreted and compared with presently available theories, which are revisited following a new insight. Discrepancies that have been discussed in the literature are understood within our framework.

Decay of unstable states in the presence of colored noise and random initial conditions. I. Theory of nonlinear relaxation times

The general theory of nonlinear relaxation times is developed for the case of Gaussian colored noise. General expressions are obtained and applied to the study of the characteristic decay time of unstable states in different situations, including white and colored noise, with emphasis on the distributed initial conditions. Universal effects of the coupling between colored noise and random initial conditions are predicted.

Decay of unstable states in the presence of colored noise and random initial conditions. II. Analog experiments and digital simulations

The decay of an unstable state under the influence of external colored noise has been studied by means of analog experiments and digital simulations. For both fixed and random initial conditions, the time evolution of the second moment ¿x2(t)¿ of the system variable was determined and then used to evaluate the nonlinear relaxation time. The results obtained are found to be in excellent agreement with the theoretical predictions of the immediately preceding paper [Casademunt, Jiménez-Aquino, and Sancho, Phys. Rev. A 40, 5905 (1989)].

Colored noise in spatially extended systems

We study the effects of time and space correlations of an external additive colored noise on the steady-state behavior of a time-dependent Ginzburg-Landau model. Simulations show the existence of nonequilibrium phase transitions controlled by both the correlation time and length of the noise. A Fokker-Planck equation and the steady probability density of the process are obtained by means of a theoretical approximation.

Mean first-passage time of continuous non-Markovian processes driven by colored noise

An equation for mean first-passage times of non-Markovian processes driven by colored noise is derived through an appropriate backward integro-differential equation. The equation is solved in a Bourret-like approximation. In a weak-noise bistable situation, non-Markovian effects are taken into account by an effective diffusion coefficient. In this situation, our results compare satisfactorily with other approaches and experimental data.

First-passage times for a marginal state driven by colored noise

The dynamical process through a marginal state (saddle point) driven by colored noise is studied. For small correlation time of the noise, the mean first-passage time and its variance are calculated using standard methods. When the correlation time of the noise is finite or large, an alternative approach, based on simple physical arguments, is proposed. It will allow us to study also the passage times of an unstable state. The theoretical predictions are tested satisfactorily by the use of computer simulations.

Theory for correlation functions of processes driven by external colored noise

We study steady-state correlation functions of nonlinear stochastic processes driven by external colored noise. We present a methodology that provides explicit expressions of correlation functions approximating simultaneously short- and long-time regimes. The non-Markov nature is reduced to an effective Markovian formulation, and the nonlinearities are treated systematically by means of double expansions in high and low frequencies. We also derive some exact expressions for the coefficients of these expansions for arbitrary noise by means of a generalization of projection-operator techniques.

Intensity correlation functions of dye lasers: Comparison of colored-gain-noise and colored-loss-noise models

The intensity correlation functions C(t) for the colored-gain-noise model of dye lasers are analyzed and compared with those for the loss-noise model. For correlation times ¿ larger than the deterministic relaxation time td, we show with the use of the adiabatic approximation that C(t) values coincide for both models. For small correlation times we use a method that provides explicit expressions of non-Markovian correlation functions, approximating simultaneously short- and long-time behaviors. Comparison with numerical simulations shows excellent results simultaneously for short- and long-time regimes. It is found that, when the correlation time of the noise increases, differences between the gain- and loss-noise models tend to disappear. The decay of C(t) for both models can be described by a time scale that approaches the deterministic relaxation time. However, in contrast with the loss-noise model, a secondary time scale remains for large times for the gain-noise model, which could allow one to distinguish between both models.