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

EXONEST: The Bayesian Exoplanetary Explorer

The fields of astronomy and astrophysics are currently engaged in an unprecedented era of discovery as recent missions have revealed thousands of exoplanets orbiting other stars. While the Kepler Space Telescope mission has enabled most of these exoplanets to be detected by identifying transiting events, exoplanets often exhibit additional photometric effects that can be used to improve the characterization of exoplanets. The EXONEST Exoplanetary Explorer is a Bayesian exoplanet inference engine based on nested sampling and originally designed to analyze archived Kepler Space Telescope and CoRoT (Convection Rotation et Transits plan\'etaires) exoplanet mission data. We discuss the EXONEST software package and describe how it accommodates plug-and-play models of exoplanet-associated photometric effects for the purpose of exoplanet detection, characterization and scientific hypothesis testing. The current suite of models allows for both circular and eccentric orbits in conjunction with photometric effects, such as the primary transit and secondary eclipse, reflected light, thermal emissions, ellipsoidal variations, Doppler beaming and superrotation. We discuss our new efforts to expand the capabilities of the software to include more subtle photometric effects involving reflected and refracted light. We discuss the EXONEST inference engine design and introduce our plans to port the current MATLAB-based EXONEST software package over to the next generation Exoplanetary Explorer, which will be a Python-based open source project with the capability to employ third-party plug-and-play models of exoplanet-related photometric effects.Comment: 30 pages, 8 figures, 5 tables. Presented at the 37th International Workshop on Bayesian Inference and Maximum Entropy Methods in Science and Engineering (MaxEnt 2017) in Jarinu/SP Brasi

Gallium Containing Glass Polyalkenoate Bone Cements: Glass Characterization and Physical Properties

Gallium (Ga) glasses were developed to formulate a Glass Polyalkenoate Cement (GPC) series with both E9 and E11 polyacrylic acid (PAA) at 50, 55 and 60wt% additions. Working times (T w), setting times (T s), compression (σ c), and biaxial flexural (σ f) strength testing were evaluated to determine the GPCs potential use in orthopedics. © 2012 IEEE

Gallium Containing Glass Polyalkenoate Bone Cements: Ion Release and E. Coli Inhibition

The Glass Polyalkenoate Cement (GPC) series (LCon., LGa-1 and LGa-2) containing gallium (Ga) and a 50 wt% addition of E11 polyacrylic acid (PAA), previously developed, was evaluated for ion release, specifically Si, Ca, Zn and Ga, and E. coli inhibition. The maximum inhibition was observed in the t = 0 samples and was 0.35 mm for LCon. and 0.65 mm for LGa-1 and LGa-2. © 2013 IEEE

Gallium Containing Glass Polyalkenoate Anti-Cancerous Bone Cements: Glass Characterization and Physical Properties

A gallium (Ga) glass series (0.48SiO2-0.40ZnO-0.12CaO, with 0.08 mol% substitution for ZnO) was developed to formulate a Ga-containing Glass Polyalkenoate Cement (GPC) series. Network connectivity (NC) and X-ray Photoelectron Spectroscopy (XPS) was employed to investigate the role of Ga3+ in the glass, where it is assumed to act as a network modifier. Ga-GPC series was formulated with E9 and E11 polyacrylic acid (PAA) at 50, 55 and 60 wt% additions. E11 working times (Tw) ranged from 68 to 96 s (Lcon.) and 106 s for the Ga-GPCs (LGa-1 and LGa-2). Setting times (Ts) ranged from 104 to 226 s (Lcon.) and 211 s for LGa-1 and LGa-2. Compression (δc) and biaxial flexural (δf) testing were conducted where Lcon. increased from 62 to 68 MPa, LGa-1 from 14 to 42 MPa and LGa-2 from 20 to 47 MPa in δc over 1-30 days. δf testing revealed that Lcon. increased from 29 to 42 MPa, LGa-1 from 7 to 32 MPa and LGa-2 from 12 to 36 MPa over 1-30 days. © 2012 Springer Science+Business Media, LLC

Relating Ion Release and PH to in Vitro Cell Viability for Gallium-Inclusive Bioactive Glasses

A bioactive glass (BG) in which Ga was substituted for Zn was formulated to investigate whether the ionic form of Ga can elicit effects similar to gallium nitrate. The ion release and pH of BG extracts were evaluated, as well as the in vitro cytocompatibility of extracts in contact with mouse fibroblasts and human osteoblasts. After incubation times of 1 year, the glass (TGa-1) containing the smaller Ga-addition (8 mol%) released the most sodium (Na) (1420 mg/L), silicon (Si) (221 mg/L), and Ga (1295 mg/L), while the glass (TGa-2) containing the larger Ga-addition (16 mol%), exhibited release levels between TGa-1, and the 0 mol% Ga (Control) glass. The pH of all 3 glass extracts steadily increased over time, with maximums observed after 365 days for Control (10.0), TGa-1 (12.2), and TGa-2 (9.7). Cell viability analysis suggested that Ga-release produced toxic effects in L-929 fibroblasts, with less than 3 % viability for both TGa-1 and TGa-2 extracts after 90, 180, and 365 days; however, no significant decrease in MC-3T3 osteoblast viability was observed for TGa-1 extracts after any time period, despite the higher ion release and pH values, and a significant decrease to 51 % viability was only observed for TGa-2 extracts after 365 days. These results suggest that tailoring the release of Ga from BG is not only possible, but also beneficial to the host, thus rendering such glasses useful in bone void-filling applications