53 research outputs found

    A model for uranium mobility in groundwater in the Grand Pré region, Nova Scotia, Canada

    Get PDF
    Elevated levels of uranium that surpass maximum allowable concentrations have been recognized in some well water samples throughout Nova Scotia. In this study we examine the influence of redox conditions and regional geology on the mobility of uranium in groundwater in the Grand PrĂ© region, located in the eastern end of the Annapolis-Cornwallis Valley in southwestern Nova Scotia. The study site is underlain by carbon-rich shale and arkosic sandstone of the Late Mississippian Horton BluïŹ€ Formation and the arenaceous sandstone of the Triassic Wolfville Formation. Water samples from drilled wells were analyzed on site for various water quality parameters (pH, conductivity, temperature, dissolved oxygen) and in the laboratory to determine alkalinity and cation (72) and major anion (9) concentrations. Several samples exceeded Health Canada (2011) limits for uranium (20 ÎŒg/L) with values up to 50.8 ÎŒg/L and aesthetic objectives (AO) for iron (up to 605 ÎŒg/L), manganese (up to 2.28 mg/L) and other cations. Data show that diïŹ€erent redox conditions occur in the study area. The geospatial arrangement of the chemical data suggests that the lithology of the underlying aquifer strongly influences the availability of uranium in groundwater. Reduced groundwater in Horton BluïŹ€ sandstone typically contains elevated concentrations of Fe 2+ and Mn 2+ , whereas groundwater containing high concentrations of U is found primary in oxidizing environments in quartz arenite sandstone units in the Wolfville Formation. Consumption of groundwater in the Grand PrĂ© region may pose a health risk; however, the level of risk remains unknown. This study emphasizes that in the area of Grand PrĂ©, water that is considered aesthetically undesirable (containing high Fe and Mn) may pose less of a health risk (low U) than waters that are aesthetically pleasing.Des niveaux Ă©levĂ©s d’uranium qui dĂ©passent les concentrations maximales admises ont Ă©tĂ© dĂ©tectĂ©s dans certains Ă©chantillons d’eau de puits en Nouvelle Écosse. Dans cette Ă©tude, nous examinons les eïŹ€ets de la rĂ©duction-oxydation et de la gĂ©ologie rĂ©gionale sur la mobilitĂ© de l’uranium dans l’eau souterraine de la rĂ©gion de Grand PrĂ©, dans l’extrĂ©mitĂ© est de la vallĂ©e d’Annapolis-Cornwallis, dans le sud ouest de la Nouvelle Écosse. Le site Ă©tudiĂ© repose sur du schiste charbonneux et du grĂšs arkosique de la Formation de Horton BluïŹ€, du Mississippien tardif, et sur du grĂšs arĂ©nacĂ© de la Formation de Wolfville, du Trias. Les Ă©chantillons d’eau de puits creusĂ©s ont Ă©tĂ© analysĂ©s sur place pour ce qui est de divers paramĂštres de qualitĂ© de l’eau (pH, conductivitĂ©, tempĂ©rature, oxygĂšne dissous) et des analyses ont eu lieu en laboratoire pour Ă©tablir l’alcalinitĂ© et les concentrations de cations (72) et de principaux anions (9). Plusieurs Ă©chantillons dĂ©passaient les limites permises par SantĂ© Canada (2011), en ce qui concerne la teneur en uranium (20 ÎŒg/L), certaines teneurs ayant atteint 50,8 ÎŒg/L. Il en allait de mĂȘme en ce qui concerne les critĂšres esthĂ©tiques pour le fer (des teneurs ayant atteint 605 ÎŒg/L), le manganĂšse (des teneurs ayant atteint 2,28 mg/L) et d’autres cations. Les donnĂ©es indiquent que divers phĂ©nomĂšnes de rĂ©duction-oxydation surviennent dans le secteur Ă©tudiĂ©. Le contexte gĂ©ospatial des donnĂ©es chimiques porte Ă  croire que la lithologie de la couche aquifĂšre sous jacente exerce une forte influence sur la disponibilitĂ© de l’uranium dans l’eau souterraine. L’eau souterraine qui a subi une rĂ©duction dans le grĂšs de Horton BluïŹ€ contient gĂ©nĂ©ralement des concentrations Ă©levĂ©es de Fe 2+ et de Mn 2+ , tandis que l’eau souterraine Ă  forte concentration d’uranium est surtout observĂ©e dans les milieux oxydants de grĂšs de quartz-arĂ©nite de la Formation de Wolfville. La consommation de l’eau souterraine dans la rĂ©gion de Grand PrĂ© peut poser un risque pour la santĂ©, mais le degrĂ© de risque demeure inconnu. Cette Ă©tude met en lumiĂšre le risque moindre pour la santĂ© (faible teneur en U) de l’eau dans la rĂ©gion de Grand PrĂ©, qui a une apparence pouvant laisse Ă  dĂ©sirer (elle a une forte teneur en Fe et en Mn), comparativement Ă  d’autres sources d’eau d’apparence plus agrĂ©able. [Traduit par la redaction

    Analysing co-evolution among artificial 3D creatures

    Get PDF
    This paper is concerned with the analysis of coevolutionary dynamics among 3D artificial creatures, similar to those introduced by Sims (1). Coevolution is subject to complex dynamics which are notoriously difficult to analyse. We introduce an improved analysis method based on Master Tournament matrices [2], which we argue is both less costly to compute and more informative than the original method. Based on visible features of the resulting graphs, we can identify particular trends and incidents in the dynamics of coevolution and look for their causes. Finally, considering that coevolutionary progress is not necessarily identical to global overall progress, we extend this analysis by cross-validating individuals from different evolutionary runs, which we argue is more appropriate than single-record analysis method for evaluating the global performance of individuals

    Transcriptional profiles predict treatment outcome in patients with tuberculosis and diabetes at diagnosis and at two weeks after initiation of anti-tuberculosis treatment.

    Get PDF
    BACKGROUND: Globally, the tuberculosis (TB) treatment success rate is approximately 85%, with treatment failure, relapse and death occurring in a significant proportion of pulmonary TB patients. Treatment success is lower among people with diabetes mellitus (DM). Predicting treatment outcome early after diagnosis, especially in TB-DM patients, would allow early treatment adaptation for individuals and may improve global TB control. METHODS: Samples were collected in a longitudinal cohort study of adult TB patients from South Africa (n  =  94) and Indonesia (n  =  81), who had concomitant DM (n  =  59), intermediate hyperglycaemia (n  =  79) or normal glycaemia/no DM (n  =  37). Treatment outcome was monitored, and patients were categorized as having a good (cured) or poor (failed, recurrence, died) outcome during treatment and 12 months follow-up. Whole blood transcriptional profiles before, during and at the end of TB treatment were characterized using unbiased RNA-Seq and targeted gene dcRT-MLPA. FINDINGS: We report differences in whole blood transcriptome profiles, which were observed before initiation of treatment and throughout treatment, between patients with a good versus poor TB treatment outcome. An eight-gene and a 22-gene blood transcriptional signature distinguished patients with a good TB treatment outcome from patients with a poor TB treatment outcome at diagnosis (AUC = 0·815) or two weeks (AUC = 0·834) after initiation of TB treatment, respectively. High accuracy was obtained by cross-validating this signature in an external cohort (AUC = 0·749). INTERPRETATION: These findings suggest that transcriptional profiles can be used as a prognostic biomarker for treatment failure and success, even in patients with concomitant DM. FUNDING: The research leading to these results, as part of the TANDEM Consortium, received funding from the European Community's Seventh Framework Programme (FP7/2007-2013 Grant Agreement No. 305279) and the Netherlands Organization for Scientific Research (NWO-TOP Grant Agreement No. 91214038). The research leading to the results presented in the Indian validation cohort was supported by Research Council of Norway Global Health and Vaccination Research (GLOBVAC) projects: RCN 179342, 192534, and 248042, the University of Bergen (Norway)

    Impaired resolution of blood transcriptomes through tuberculosis treatment with diabetes comorbidity

    Get PDF
    Background People with diabetes are more likely to develop tuberculosis (TB) and to have poor TB-treatment outcomes than those without. We previously showed that blood transcriptomes in people with TB-diabetes (TB-DM) co-morbidity have excessive inflammatory and reduced interferon responses at diagnosis. It is unknown whether this persists through treatment and contributes to the adverse outcomes. Methods Pulmonary TB patients recruited in South Africa, Indonesia and Romania were classified as having TB-DM, TB with prediabetes, TB-related hyperglycaemia or TB-only, based on glycated haemoglobin concentration at TB diagnosis and after 6 months of TB treatment. Gene expression in blood at diagnosis and intervals throughout treatment was measured by unbiased RNA-Seq and targeted Multiplex Ligation-dependent Probe Amplification. Transcriptomic data were analysed by longitudinal mixed-model regression to identify whether genes were differentially expressed between clinical groups through time. Predictive models of TB-treatment response across groups were developed and cross-tested. Results Gene expression differed between TB and TB-DM patients at diagnosis and was modulated by TB treatment in all clinical groups but to different extents, such that differences remained in TB-DM relative to TB-only throughout. Expression of some genes increased through TB treatment, whereas others decreased: some were persistently more highly expressed in TB-DM and others in TB-only patients. Genes involved in innate immune responses, anti-microbial immunity and inflammation were significantly upregulated in people with TB-DM throughout treatment. The overall pattern of change was similar across clinical groups irrespective of diabetes status, permitting models predictive of TB treatment to be developed. Conclusions Exacerbated transcriptome changes in TB-DM take longer to resolve during TB treatment, meaning they remain different from those in uncomplicated TB after treatment completion. This may indicate a prolonged inflammatory response in TB-DM, requiring prolonged treatment or host-directed therapy for complete cure. Development of transcriptome-based biomarker signatures of TB-treatment response should include people with diabetes for use across populations

    A collaborative approach to adopting/adapting guidelines - the Australian 24-hour Movement Guidelines for the early years (birth to 5 years): an integration of physical activity, sedentary behavior, and sleep

    Get PDF
    BACKGROUND: In 2017, the Australian Government funded the update of the National Physical Activity Recommendations for Children 0-5 years, with the intention that they be an integration of movement behaviours across the 24-h period. The benefit for Australia was that it could leverage research in Canada in the development of their 24-h guidelines for the early years. Concurrently, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) working group published a model to produce guidelines based on adoption, adaption and/or de novo development using the GRADE evidence-to-decision framework. Referred to as the GRADE-ADOLOPMENT approach, it allows guideline developers to follow a structured and transparent process in a more efficient manner, potentially avoiding the need to unnecessarily repeat costly tasks such as conducting systematic reviews. The purpose of this paper is to outline the process and outcomes for adapting the Canadian 24-Hour Movement Guidelines for the Early Years to develop the Australian 24-Hour Movement Guidelines for the Early Years guided by the GRADE-ADOLOPMENT framework. METHODS: The development process was guided by the GRADE-ADOLOPMENT approach. A Leadership Group and Consensus Panel were formed and existing credible guidelines identified. The draft Canadian 24-h integrated movement guidelines for the early years best met the criteria established by the Panel. These were evaluated based on the evidence in the GRADE tables, summaries of findings tables and draft recommendations from the Canadian Draft Guidelines. Updates to each of the Canadian systematic reviews were conducted and the Consensus Panel reviewed the evidence for each behaviour separately and made a decision to adopt or adapt the Canadian recommendations for each behaviour or create de novo recommendations. An online survey was then conducted (n = 302) along with five focus groups (n = 30) and five key informant interviews (n = 5) to obtain feedback from stakeholders on the draft guidelines. RESULTS: Based on the evidence from the Canadian systematic reviews and the updated systematic reviews in Australia, the Consensus Panel agreed to adopt the Canadian recommendations and, apart from some minor changes to the wording of good practice statements, keep the wording of the guidelines, preamble and title of the Canadian Guidelines. The Australian Guidelines provide evidence-informed recommendations for a healthy day (24-h), integrating physical activity, sedentary behaviour (including limits to screen time), and sleep for infants (<1 year), toddlers (1-2 years) and preschoolers (3-5 years). CONCLUSIONS: To our knowledge, this is only the second time the GRADE-ADOLOPMENT approach has been used. Following this approach, the judgments of the Australian Consensus Panel did not differ sufficiently to change the directions and strength of the recommendations and as such, the Canadian recommendations were adopted with very minor alterations. This allowed the Guidelines to be developed much faster and at lower cost. As such, we would recommend the GRADE-ADOLOPMENT approach, especially if a credible set of guidelines, with all supporting materials and developed using a transparent process, is available. Other countries may consider using this approach when developing and/or revising national movement guidelines

    Spatial growth rate of emerging SARS-CoV-2 lineages in England, September 2020-December 2021

    Get PDF
    This paper uses a robust method of spatial epidemiological analysis to assess the spatial growth rate of multiple lineages of SARS-CoV-2 in the local authority areas of England, September 2020–December 2021. Using the genomic surveillance records of the COVID-19 Genomics UK (COG-UK) Consortium, the analysis identifies a substantial (7.6-fold) difference in the average rate of spatial growth of 37 sample lineages, from the slowest (Delta AY.4.3) to the fastest (Omicron BA.1). Spatial growth of the Omicron (B.1.1.529 and BA) variant was found to be 2.81× faster than the Delta (B.1.617.2 and AY) variant and 3.76× faster than the Alpha (B.1.1.7 and Q) variant. In addition to AY.4.2 (a designated variant under investigation, VUI-21OCT-01), three Delta sublineages (AY.43, AY.98 and AY.120) were found to display a statistically faster rate of spatial growth than the parent lineage and would seem to merit further investigation. We suggest that the monitoring of spatial growth rates is a potentially valuable adjunct to outbreak response procedures for emerging SARS-CoV-2 variants in a defined population
    • 

    corecore