Probability of Causation for Lung Cancer After Exposure to Radon Progeny: A Comparison of Models and Data

The estimates of lung cancer risk due to the exposure to radon decay products are based on different data sets from underground mining and on different mathematical models that are used to fit the data. Diagrams of the excess relative rate per 100 working level months in its dependence on age at exposure and age attained are shown to be a useful tool to elucidate the influence that is due to the choice of the model, and to assess the differences between the data from the major western cohorts and those from the Czech uranium miners. It is seen that the influence of the choice of the model is minor compared to the difference between the data sets. The results are used to derive attributable lifetime risks and probabilities of causation for lung cancer following radon progeny exposures

A Survey of the Czechoslovak Follow-up of Lung Cancer Mortality in Uranium Miners

The major Czechoslovak cohort of uranium miners (S-cohort) is surveyed in terms of diagrams illustrating dependences on calendar year, age, and exposure to radon and radon progeny. An analysis of the dose dependence of lung cancer mortality is performed by nonparametric and, subsequently, by parametric methods. In the first step, two-dimensional isotonic regression is employed to derive the lung cancer mortality rate and the relative excess risk as functions of age attained and of lagged cumulated exposure. In a second step, analytical fits in terms of relative risk models are derived. The treatment is largely analogous to the methods applied by the BEIR IV Committee to other major cohorts of uranium miners. There is a marked dependence of the excess risk on age attained and on time since exposure. A specific characteristic of the Czechoslovak data is the nonlinearity of the dependence of the lung cancer excess risk on the cumulated exposure; exposures on the order of 100 working level months or less appear to be more effective per working level month than larger exposures but, in the absence of an internal control group, this cannot be excluded to be due to confounders such as smoking or environmental exposures. A further notable observation is the association of larger excess risks with longer protraction of the exposures

Insights into Pharmacotherapy Management for Parkinson's Disease Patients Using Wearables Activity Data.

We investigate what supervised classification models using clinical and wearables data are best suited to address two important questions about the management of Parkinson's Disease (PD) patients: 1) does a PD patient require pharmacotherapy or not, and 2) whether therapies are having an effect. Currently, patient management is suboptimal due to using subjective patient reported episodes to answer these questions. METHODOLOGY: Clinical and real environment sensor data (memory, tapping, walking) was provided by the mPower study (6805 participants). From the data, we derived relevant clinical scenarios: S1) before vs. after initiating pharmacotherapy, and S2) before vs. after taking medication. For each scenario we designed and tested 6 methods of supervised classification. Precision, Accuracy and Area Under the Curve (AUC) were computed using 10-fold cross-validation. RESULTS: The best classification models were: S1) Decision Trees on Tapping activity data (AUC 0.95, 95% CI 0.05); and S2) K-Nearest Neighbours on Gait data (mean AUC 0.70, 95% CI 0.07, 46% participants with AUC > 0.70). CONCLUSIONS: Automatic patient classification based on sensor activity data can objectively inform PD medication management, with significant potential for improving patient care

High Current Diffusion Type Diodes at Cryogenic Temperatures for the LHC Superconducting Magnet Protection

High-current by-pass diodes are required for the protection of the superconducting magnets for the Large Hadron Collider LHC at CERN . These diodes are at liquid helium tem-perature and will be exposed to irradiation. With the re-location of the by-pass diodes for the main dipoles underneath the iron yoke and of those for the quadrupoles at the bottom of the cryostat the new estimations for the irradiation dose amounts to about 30 Gy and a neutron fluence of about 1.5 x 1011 n/cm2 for the dipole di-odes and about 100 Gy and5 x 1011 n/cm2 for the quadrupole diodes during 10 years. These relatively low doses may allow the use of diffusion type diodes in-stead of epitaxial diodes. The electrical characteristics of several diodes were measured at temperatures in the range between 1.8K and 300K. Diffu-sion type diodes from three manufacturers were submitted to high current endurance tests in liquid helium. Electrical characteristics and temperatures were measured versus time and showed acceptable results. First irradiation tests show that modified diffusion diodes can be used at least for the dipole by-pass

Fermion sea along the sphaleron barrier

In this revised version we have improved the treatment of the top and bottom quark mass. This leads to slight changes of the numerical results, especially of those presented in Fig.4. The discussion of the numerical procedure and accuracy has been extended.Comment: 39 pages (LaTex) plus 5 figures (uuencoded postscript files); RUB-TPII-62/93, to appear in Phys.Rev.

Integrability and Ergodicity of Classical Billiards in a Magnetic Field

We consider classical billiards in plane, connected, but not necessarily bounded domains. The charged billiard ball is immersed in a homogeneous, stationary magnetic field perpendicular to the plane. The part of dynamics which is not trivially integrable can be described by a "bouncing map". We compute a general expression for the Jacobian matrix of this map, which allows to determine stability and bifurcation values of specific periodic orbits. In some cases, the bouncing map is a twist map and admits a generating function which is useful to do perturbative calculations and to classify periodic orbits. We prove that billiards in convex domains with sufficiently smooth boundaries possess invariant tori corresponding to skipping trajectories. Moreover, in strong field we construct adiabatic invariants over exponentially large times. On the other hand, we present evidence that the billiard in a square is ergodic for some large enough values of the magnetic field. A numerical study reveals that the scattering on two circles is essentially chaotic.Comment: Explanations added in Section 5, Section 6 enlarged, small errors corrected; Large figures have been bitmapped; 40 pages LaTeX, 15 figures, uuencoded tar.gz. file. To appear in J. Stat. Phys. 8

Study of 6^{6}He+12^{12}C Elastic Scattering Using a Microscopic Optical Potential

The $^6$He+$^{12}$C elastic scattering data at beam energies of 3, 38.3 and 41.6 MeV/nucleon are studied utilizing the microscopic optical potentials obtained by a double-folding procedure and also by using those inherent in the high-energy approximation. The calculated optical potentials are based on the neutron and proton density distributions of colliding nuclei established in an appropriate model for $^6$He and obtained from the electron scattering form factors for $^{12}$C. The depths of the real and imaginary parts of the microscopic optical potentials are considered as fitting parameters. At low energy the volume optical potentials reproduce sufficiently well the experimental data. At higher energies, generally, additional surface terms having form of a derivative of the imaginary part of the microscopic optical potential are needed. The problem of ambiguity of adjusted optical potentials is resolved requiring the respective volume integrals to obey the determined dependence on the collision energy. Estimations of the Pauli blocking effects on the optical potentials and cross sections are also given and discussed. Conclusions on the role of the aforesaid effects and on the mechanism of the considered processes are made.Comment: 12 pages, 9 figures, accepted for publication in Physical Review