129 research outputs found
The Flux-integral Method for Multidimensional Convection and Diffusion
The flux-integral method is a procedure for constructing an explicit, single-step, forward-in-time, conservative, control volume update of the unsteady, multidimensional convection-diffusion equation. The convective plus diffusive flux at each face of a control-volume cell is estimated by integrating the transported variable and its face-normal derivative over the volume swept out by the convecting velocity field. This yields a unique description of the fluxes, whereas other conservative methods rely on nonunique, arbitrary pseudoflux-difference splitting procedures. The accuracy of the resulting scheme depends on the form of the subcell interpolation assumed, given cell-average data. Cellwise constant behavior results in a (very artificially diffusive) first-order convection scheme. Second-order convection-diffusion schemes correspond to cellwise linear (or bilinear) subcell interpolation. Cellwise quadratic subcell interpolants generate a highly accurate convection-diffusion scheme with excellent phase accuracy. Under constant-coefficient conditions, this is a uniformly third-order polynomial interpolation algorithm (UTOPIA)
ENSEMBLES: a new multi-model ensemble for seasonal-to-annual predictions: Skill and progress beyond DEMETER in forecasting tropical Pacific SSTs
A new 46-year hindcast dataset for seasonal-to-annual ensemble predictions has been created using a multi-model ensemble of 5 state-of-the-art coupled atmosphere-ocean circulation models. The multi-model outperforms any of the single-models in forecasting tropical Pacific SSTs because of reduced RMS errors and enhanced ensemble dispersion at all lead-times. Systematic errors are considerably reduced over the previous generation (DEMETER). Probabilistic skill scores show higher skill for the new multi-model ensemble than for DEMETER in the 4–6 month forecast range. However, substantially improved models would be required to achieve strongly statistical significant skill increases. The combination of ENSEMBLES and DEMETER into a grand multi-model ensemble does not improve the forecast skill further. Annual-range hindcasts show anomaly correlation skill of ∼0.5 up to 14 months ahead. A wide range of output from the multi-model simulations is becoming publicly available and the international community is invited to explore the full scientific potential of these data
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Progress on Cleaning Up the Only Commercial Nuclear Fuel Reprocessing Facility to Operate in the United States
This paper describes the progress on cleanup of the West Valley Demonstration Project (WVDP), an environmental management project located south of Buffalo, NY. The WVDP was the site of the only commercial nuclear fuel reprocessing facility to have operated in the United States (1966 to 1972). Former fuel reprocessing operations generated approximately 600,000 gallons of liquid high-level radioactive waste stored in underground tanks. The U.S. Congress passed the WVDP Act in 1980 (WVDP Act) to authorize cleanup of the 220-acre facility. The facility is unique in that it sits on the 3,345-acre Western New York Nuclear Service Center (WNYNSC), which is owned by New York State through the New York State Energy Research and Development Authority (NYSERDA). The U.S. Department of Energy (DOE) has overall responsibility for the cleanup that is authorized by the WVDP Act, paying 90 percent of the WVDP costs; NYSERDA pays 10 percent. West Valley Nuclear Services Company (WVNSCO) is the management contractor at the WVDP. This paper will provide a description of the many accomplishments at the WVDP, including the pretreatment and near completion of vitrification of all the site's liquid high-level radioactive waste, a demonstration of technologies to characterize the remaining material in the high-level waste tanks, the commencement of decontamination and decommissioning (D&D) activities to place the site in a safe configuration for long-term site management options, and achievement of several technological firsts. It will also include a discussion of the complexities involved in completing the WVDP due to the various agency interests that require integration for future cleanup decisions
Psychosocial adjustment in newly diagnosed prostate cancer
Objective: To examine the psychological and social adjustment of men with early or advanced stage prostate cancer and to compare them with a matched group of cancer-free community volunteers. Methods: A longitudinal observational study in which 367 men recently diagnosed with early (n =211) or advanced stage (n = 156), prostate cancer were compared to 169 cancer-free men from the community, of similar age and residential area, using self-report measures of psychosocial adjustment. Results: On the mental health subscales of the Short-Form 36-item Health Survey, men with advanced disease had lower vitality and social functioning than the other two groups, and lower mental health scores than the comparison group. Both patient groups had lower role-emotional scores than the comparison group. With regard to the Brief Symptom Inventory, the advanced disease group had higher somatization scores, and lower interpersonal sensitivity and paranoid ideation scores than the early stage group and the community comparison group. In terms of psychiatric morbidity, there were higher rates of anxiety disorders but not depressive disorders in both patient groups although overall diagnosis rates were low. No differences were found in terms of couple or family functioning. Conclusions: There is impairment in psychosocial function in men with prostate cancer, particularly those with advanced disease, but no increase in the rate of formal psychiatric disorder or adverse effects on the couples and families. This suggests directions for psychosocial interventions with these patient group
Submesoscale Instabilities in Mesoscale Eddies
Submesoscale processes have been extensively studied in observations and simulations of fronts. Recent idealized simulations show that submesoscale instabilities also occur in baroclinic mesoscale cyclones and anticyclones. The instabilities in the anticyclone grow faster and at coarser grid resolution than in the cyclone. The instabilities lead to larger restratification in the anticyclone than in the cyclone. The instabilities also lead to changes in the mean azimuthal jet around the anticyclone from 2-km resolution, but a similar effect only occurs in the cyclone at 0.25-km resolution. A numerical passive tracer experiment shows that submesoscale instabilities lead to deeper subduction in the interior of anticyclonic than cyclonic eddies because of outcropping isopycnals extending deeper into the thermocline in anticyclones. An energetic analysis suggests that both vertical shear production and vertical buoyancy fluxes are important in anticyclones but primarily vertical buoyancy fluxes occur in cyclones at these resolutions. The energy sources and sinks vary azimuthally around the eddies caused by the asymmetric effects of the Ekman buoyancy flux. Glider transects of a mesoscale anticyclone in the Tasman Sea show that water with low stratification and high oxygen concentrations is found in an anticyclone, in a manner that may be consistent with the model predictions for submesoscale subduction in mesoscale eddies
Identification of tumour-associated and germ line p53 mutations in canine mammary cancer
Mutations of the tumour suppressor p53 gene are found in a number of spontaneous canine cancers and may contribute to increased cytogenetic alterations and tumour formation. Using reverse transcription and DNA amplification, we isolated p53 cDNA from normal and tumour tissue of ten canine mammary cancer patients. DNA sequencing identified p53 mutations in three of the ten patients. These included tumour-associated p53 gene mutations within exons 2 and 5 and a germ line deletion of exons 3 to 7. These results support a role for p53 inactivation in canine mammary tumour formation and breed predisposition to cancer. Such information could prove invaluable in the successful outbreeding of inherited predisposition to cancer in the dog. A putative polymorphism was also identified at codon 69 in exon 4 and we discuss the possibility that similar polymorphisms may be associated with human breast cancer. © 1999 Cancer Research Campaig
Understanding the Importance of Context:A Qualitative Study of a Location-Based Exergame to Enhance School Childrens Physical Activity
Many public health interventions are less effective than expected in 'real life settings', yet little work is undertaken to understand the reasons why. The effectiveness of complex public health interventions can often be traced back to a robust programme theory (how and why an intervention brings about a change in outcome(s)) and assumptions that are made about the context in which it is implemented. Understanding whether effectiveness (or lack thereof) is due to the intervention or the context is hugely helpful in decisions about whether to a) modify the intervention; b) modify the context; c) stop providing the intervention. Exergames-also known as Active Video Games or AVGS-are video games which use the player's bodily movements as input and have potential to increase physical activity in children. However, the results of a recent pilot randomised controlled trial (RCT) of a location-based exergame (FitQuest) in a school setting were inconclusive; no significant effect was detected for any of the outcome measures. The aim of this study was to explore whether the programme theory for FitQuest was correct with respect to how and why it would change children's perceptions of physical activity (PA) and exercise self-efficacy in the school setting. A further aim was to investigate the features of the school setting (context) that may impact on FitQuest's implementation and effectiveness. Qualitative data (gathered during the RCT) were gathered from interviews with teachers and children, and observation of sessions using FitQuest. Thematic analysis indicated that whilst children enjoyed playing the game, engaged with goal setting within the game context and undertook low to vigorous physical activity, there were significant contextual factors that prevented it from being played as often as intended. These included environmental factors (e.g. size of the playground), school factors (cancellations due to other activities), school technology policy (rules relating to mobile phone usage) and teacher factors (engagement with the intervention). A revised logic model for the FitQuest intervention indicates how both the design of exergame technology (intervention) and features of the school environment (context) could be improved to increase chances of effectiveness in the future
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