Unsaturated zone moisture and vapor movement induced by temperature variations in asphalt barrier field lysimeters

Protective barriers are being considered for use at the Hanford Site to enhance the isolation of radioactive wastes from water, plant, and animal intrusion. Lysimeters were constructed to evaluate the performance of asphalt barrier formulations under natural environmental conditions. These lysimeters were constructed of 1.7-m lengths of PVC pipe that have a diameter of 30 cm. The lysimeters were filled with layers of gravel, coarse sand, and asphalt. The sand and gravel placed under the asphalt barrier were wet when installed. TOUGH was used to conduct simulations to assess the effect of temperature variations on moisture and vapor movement beneath the asphalt layer in field test lysimeters. All variables in TOUGH were converted to double precision so that simulations could be run on a Sun-4 UNIX workstation. A radially symmetric grid was used to simulate the lysimeter. 8 refs., 9 figs

Distinct germline genetic susceptibility profiles identified for common non-Hodgkin lymphoma subtypes

Lymphoma risk is elevated for relatives with common non-Hodgkin lymphoma (NHL) subtypes, suggesting shared genetic susceptibility across subtypes. To evaluate the extent of mutual heritability among NHL subtypes and discover novel loci shared among subtypes, we analyzed data from eight genome-wide association studies within the InterLymph Consortium, including 10,629 cases and 9505 controls. We utilized Association analysis based on SubSETs (ASSET) to discover loci for subsets of NHL subtypes and evaluated shared heritability across the genome using Genome-wide Complex Trait Analysis (GCTA) and polygenic risk scores. We discovered 17 genome-wide significant loci (P < 5 × 10−8) for subsets of NHL subtypes, including a novel locus at 10q23.33 (HHEX) (P = 3.27 × 10−9). Most subset associations were driven primarily by only one subtype. Genome-wide genetic correlations between pairs of subtypes varied broadly from 0.20 to 0.86, suggesting substantial heterogeneity in the extent of shared heritability among subtypes. Polygenic risk score analyses of established loci for different lymphoid malignancies identified strong associations with some NHL subtypes (P < 5 × 10−8), but weak or null associations with others. Although our analyses suggest partially shared heritability and biological pathways, they reveal substantial heterogeneity among NHL subtypes with each having its own distinct germline genetic architecture

Model assessment of protective barriers: Part 3

Radioactive waste exists at the US Department of Energy's (DOE's) Hanford Site in a variety of locations, including subsurface grout and tank farms, solid waste burial grounds, and contaminated soil sites. Some of these waste sites may need to be isolated from percolating water to minimize the potential for transport of the waste to the ground water, which eventually discharges to the Columbia River. Multilayer protective barriers have been proposed as a means of limiting the flow of water through the waste sites (DOE 1987). A multiyear research program (managed jointly by Pacific Northwest Laboratory (PNL) and Westinghouse Hanford Company for the DOE) is aimed at assessing the performance of these barriers. One aspect of this program involves the use of computer models to predict barrier performance. Three modeling studies have already been conducted and a test plan was produced. The simulation work reported here was conducted by PNL and extends the previous modeling work. The purpose of this report are to understand phenomena that have been observed in the field and to provide information that can be used to improve hydrologic modeling of the protective barrier. An improved modeling capability results in better estimates of barrier performance. Better estimates can be used to improve the design of barriers and the assessment of their long-term performance

Statistical uncertainty analysis of radon transport in nonisothermal, unsaturated soils

To accurately predict radon fluxes soils to the atmosphere, we must know more than the radium content of the soil. Radon flux from soil is affected not only by soil properties, but also by meteorological factors such as air pressure and temperature changes at the soil surface, as well as the infiltration of rainwater. Natural variations in meteorological factors and soil properties contribute to uncertainty in subsurface model predictions of radon flux, which, when coupled with a building transport model, will also add uncertainty to predictions of radon concentrations in homes. A statistical uncertainty analysis using our Rn3D finite-element numerical model was conducted to assess the relative importance of these meteorological factors and the soil properties affecting radon transport. 10 refs., 10 figs., 3 tabs

Radon transport from the subsurface: The roles of certain boundary conditions at subsurface/environment boundaries

The effects of wind on radon transport from its soil source to the environment are examined in two situations. In the first situation, the removal of radon from the soil-air interface was found to be partially rate limiting in conditions of nearly stagnant air (low wind). This gas-phase mass transfer limitation became especially important when high exhaling advective velocities or high diffusion fluxes to the air existed. A detailed mathematical formulation for one-dimensional steady-state radon transport from the soil to the air using an air side mass transfer coefficient was developed for this analysis. In the second situation, the Rn3D computer code was used to estimate radon concentration profiles in soils beneath a two-dimensional slab-on-grade dwelling subjected to wind pressures. Of five generic dry homogeneous soils studied (gravel, sand, silt, loam and clay), only gravel showed significant changes in subslab concentrations as a results of wind pressures. 7 refs., 6 figs., 4 tabs

‘The Living Death of Alzheimer’s’ Versus ‘Take a Walk to Keep Dementia at Bay’: Representations of Dementia in Print Media and Carer Discourse

Understanding dementia is a pressing social challenge. This paper draws on the ‘Dementia talking: care conversation and communication’ project which aims to understand how talk about, and to, people living with dementia is constructed. In this paper I draw on the construction of dementia manifest in two data-sets - a corpus of 350 recent UK national newspaper articles and qualitative data derived from in-depth interviews with informal carers. These data were analysed using a thematic discursive approach. A ‘panic-blame’ framework was evident in much of the print media coverage. Dementia was represented in catastrophic terms as a ‘tsunami’ and ‘worse than death’, juxtaposed with coverage of individualistic behavioural change and lifestyle recommendations to ‘stave off’ the condition. Contrary to this media discourse, in carers’ talk there was scant use of hyperbolic metaphor or reference to individual responsibility for dementia, and any corresponding blame and accountability. I argue that the presence of individualistic dementia ‘preventative’ behaviours in media discourse is problematic, especially in comparison to other more ‘controllable’ and treatable chronic conditions. Engagement with, and critique of, the nascent ‘panic-blame’ cultural context may be fruitful in enhancing positive social change for people diagnosed with dementia and their carers

Multilevel and latent variable modeling with composite links and exploded likelihoods

composite link, exploded likelihood, unfolding, multilevel model, generalized linear mixed model, latent variable model, item response model, factor model, frailty, zero-inflated Poisson model, gllamm,