The Aboriginal rock paintings of the Churchill River

This study is a comparative examination of the age, authorship and interpretation of aboriginal rock painting sites situated on the shores of the Churchill River of northern Saskatchewan and Manitoba. The twenty presently known sites were recorded in the years 1965, 1966, 1967 and 1969 by the author.The study combines written descriptions of the sites and their settings with reproductions of the symbols found at each site. Techniques for recording and reproducing rock paintings, developed during the course of the field studies, are described. Geographical and stylistic relationships of the paintings to other rock painting occurrences in the Canadian Shield are examined. Data derived both directly and indirectly from native Indian residents of the area is incorporated, along with historical observations on the occurrence and interpretation of the paintings. Several sets of the Churchill River paintings are at least 150 to 200 years old, while others may be considerably more recent. Specific dates of origin cannot presently be assigned to most of the sites; the potential applicability of various dating techniques is discussed. Evidence given supports an Algonkian (undoubtedly Cree) inspiration and authorship for these rock paintings, with religious observance being the basic motivation for their creation

Strong and weak lensing united III: Measuring the mass distribution of the merging galaxy cluster 1E0657-56

The galaxy cluster 1E0657-56 (z = 0.296) is remarkably well-suited for addressing outstanding issues in both galaxy evolution and fundamental physics. We present a reconstruction of the mass distribution from both strong and weak gravitational lensing data. Multi-color, high-resolution HST ACS images allow detection of many more arc candidates than were previously known, especially around the subcluster. Using the known redshift of one of the multiply imaged systems, we determine the remaining source redshifts using the predictive power of the strong lens model. Combining this information with shape measurements of "weakly" lensed sources, we derive a high-resolution, absolutely-calibrated mass map, using no assumptions regarding the physical properties of the underlying cluster potential. This map provides the best available quantification of the total mass of the central part of the cluster. We also confirm the result from Clowe et al. (2004,2006a).Comment: Accepted for publication in ApJ; Version with full-resolution figures available at http://www.slac.stanford.edu/~marusa/Work/bradac_strong_weak_III.pd

Contrasting vulnerability of drained tropical and high-latitude peatlands to fluvial loss of stored carbon

Carbon sequestration and storage in peatlands rely on consistently highwater tables. Anthropogenic pressures including drainage, burning, land conversion for agriculture, timber, and biofuel production, cause loss of peat-forming vegetation and exposure of previously anaerobic peat to aerobic decomposition. This can shift peatlands from net CO2 sinks to large CO2 sources, releasing carbon held for millennia. Peatlands also export significant quantities of carbon via fluvial pathways, mainly as dissolved organic carbon (DOC). We analyzed radiocarbon (14C) levels of DOC in drainage water from multiple peatlands in Europe and Southeast Asia, to infer differences in the age of carbon lost from intact and drained systems. In most cases, drainage led to increased release of older carbon from the peat profile but withmarked differences related to peat type. Very low DOC-14C levels in runoff from drained tropical peatlands indicate loss of very old (centuries to millennia) stored peat carbon. High-latitude peatlands appear more resilient to drainage; 14C measurements from UK blanket bogs suggest that exported DOC remains young (500 year) carbon in high-latitude systems. Rewetting at least partially offsets drainage effects on DOC age

Varenicline Versus Nicotine Replacement Therapy for Long-Term Smoking Cessation:An Observational Study Using the Clinical Practice Research Datalink

Background Smoking is the leading avoidable cause of illness and premature mortality. The first-line treatments for smoking cessation are nicotine replacement therapy and varenicline. Meta-analyses of experimental studies have shown that participants allocated to the varenicline group were 1.57 times (95% confidence interval 1.29 to 1.91 times) as likely to be abstinent 6 months after treatment as those allocated to the nicotine replacement therapy group. However, there is limited evidence about the effectiveness of varenicline when prescribed in primary care. We investigated the effectiveness and rate of adverse events of these medicines in the general population. Objective To estimate the effect of prescribing varenicline on smoking cessation rates and health outcomes. Data sources Clinical Practice Research Datalink. Methods We conducted an observational cohort study using electronic medical records from the Clinical Practice Research Datalink. We extracted data on all patients who were prescribed varenicline or nicotine replacement therapy after 1 September 2006 who were aged ≥ 18 years. We investigated the effects of varenicline on smoking cessation, all-cause mortality and cause-specific mortality and hospitalisation for: (1) chronic lung disease, (2) lung cancer, (3) coronary heart disease, (4) pneumonia, (5) cerebrovascular disease, (6) diabetes, and (7) external causes; primary care diagnosis of myocardial infarction, chronic obstructive pulmonary disease, depression, or prescription for anxiety; weight in kg; general practitioner and hospital attendance. Our primary outcome was smoking cessation 2 years after the first prescription. We investigated the baseline differences between patients prescribed varenicline and patients prescribed nicotine replacement therapy. We report results using multivariable-adjusted, propensity score and instrumental variable regression. Finally, we developed methods to assess the relative bias of the different statistical methods we used. Results People prescribed varenicline were healthier at baseline than those prescribed nicotine replacement therapy in almost all characteristics, which highlighted the potential for residual confounding. Our instrumental variable analysis results found little evidence that patients prescribed varenicline had lower mortality 2 years after their first prescription (risk difference 0.67, 95% confidence interval –0.11 to 1.46) than those prescribed nicotine replacement therapy. They had similar rates of all-cause hospitalisation, incident primary care diagnoses of myocardial infarction and chronic obstructive pulmonary disease. People prescribed varenicline subsequently attended primary care less frequently. Patients prescribed varenicline were more likely (odds ratio 1.46, 95% confidence interval 1.42 to 1.50) to be abstinent 6 months after treatment than those prescribed nicotine replacement therapy when estimated using multivariable-adjusted for baseline covariates. Patients from more deprived areas were less likely to be prescribed varenicline. However, varenicline had similar effectiveness for these groups. Conclusion Patients prescribed varenicline in primary care were more likely to quit smoking than those prescribed nicotine replacement therapy, but there was little evidence that they had lower rates of mortality or morbidity in the 4 years following the first prescription. There was little evidence of heterogeneity in effectiveness across the population

Prescription of bite-wing and panoramic radiographs in pediatric dental patients: An assessment of current trends and provider compliance

BACKGROUND: The aim of the authors was to evaluate prescription patterns for bite-wing and panoramic radiographs (PRs) for pediatric and adolescent dental patients after the implementation of the most recent guidelines from the American Dental Association and US Food and Drug Administration. METHODS: The authors accessed paid insurance claims data for all 50 states from January 1, 2013, through June 30, 2019, for patients 18 years and younger and extracted a 5% random sample population. The authors performed statistical analyses to evaluate various imaging metrics for pediatric dentists (PDs) and general practitioners (GPs). RESULTS: A total of 2,123,735 bite-wing images were ordered during 4,734,249 office visits. The average (standard deviation [SD]) time interval between bite-wing examinations ordered by GPs was 13.9 (7.4) months, and for PDs the average (SD) was 13.0 (6.7) months (P < .0001). When divided by age group, 3.5% of all bite-wings were obtained from patients aged 0 through 4 years. For PRs, the authors included 286,824 images in this study. The average (SD) time interval between PRs ordered for the same patient was 3.4 (1.3) years for PDs and 3.3 (1.4) years for GPs. One percent of all PRs were ordered for patients aged 0 through 4 years, with 403 images attributed to PDs and 2,348 to GPs. CONCLUSIONS: PDs were more likely to comply with the guidelines on radiograph prescriptions for pediatric and adolescent patients than GPs. PRACTICAL IMPLICATIONS: Inclusion of patient caries risk with insurance claims data could be considered for more appropriate administration of dental radiography. Future guidelines should be developed to include more explicit recommendations for prescribing PRs

Accuracy of UK Rapid Test Consortium (UK-RTC) "AbC-19 Rapid Test" for detection of previous SARS-CoV-2 infection in key workers: test accuracy study.

OBJECTIVE: To assess the accuracy of the AbC-19 Rapid Test lateral flow immunoassay for the detection of previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. DESIGN: Test accuracy study. SETTING: Laboratory based evaluation. PARTICIPANTS: 2847 key workers (healthcare staff, fire and rescue officers, and police officers) in England in June 2020 (268 with a previous polymerase chain reaction (PCR) positive result (median 63 days previously), 2579 with unknown previous infection status); and 1995 pre-pandemic blood donors. MAIN OUTCOME MEASURES: AbC-19 sensitivity and specificity, estimated using known negative (pre-pandemic) and known positive (PCR confirmed) samples as reference standards and secondly using the Roche Elecsys anti-nucleoprotein assay, a highly sensitive laboratory immunoassay, as a reference standard in samples from key workers. RESULTS: Test result bands were often weak, with positive/negative discordance by three trained laboratory staff for 3.9% of devices. Using consensus readings, for known positive and negative samples sensitivity was 92.5% (95% confidence interval 88.8% to 95.1%) and specificity was 97.9% (97.2% to 98.4%). Using an immunoassay reference standard, sensitivity was 94.2% (90.7% to 96.5%) among PCR confirmed cases but 84.7% (80.6% to 88.1%) among other people with antibodies. This is consistent with AbC-19 being more sensitive when antibody concentrations are higher, as people with PCR confirmation tended to have more severe disease whereas only 62% (218/354) of seropositive participants had had symptoms. If 1 million key workers were tested with AbC-19 and 10% had actually been previously infected, 84 700 true positive and 18 900 false positive results would be projected. The probability that a positive result was correct would be 81.7% (76.8% to 85.8%). CONCLUSIONS: AbC-19 sensitivity was lower among unselected populations than among PCR confirmed cases of SARS-CoV-2, highlighting the scope for overestimation of assay performance in studies involving only PCR confirmed cases, owing to "spectrum bias." Assuming that 10% of the tested population have had SARS-CoV-2 infection, around one in five key workers testing positive with AbC-19 would be false positives. STUDY REGISTRATION: ISRCTN 56609224.The study was commissioned by the UK Government’s Department of Health and Social Care. It was funded and implemented by Public Health England, supported by the NIHR Clinical Research Network (CRN) Portfolio. The Department of Health and Social Care received a report containing these data on 10/9/2020, but had no role in the study design, data collection, analysis, interpretation of results, writing of the manuscript, or the decision to publish. DW acknowledges support from the NIHR Health Protection Research Unit in Genomics and Data Enabling at the University of Warwick. HEJ, AEA, MH and IO acknowledge support from the NIHR Health Protection Research Unit in Behavioural Science and Evaluation at University of Bristol. STP is supported by an NIHR Career Development Fellowship (CDF-2016-09-018). Participants in the COMPARE study were recruited with the active collaboration of NHS Blood and Transplant (NHSBT) England (www.nhsbt.nhs.uk). Funding for COMPARE was provided by NHSBT and the NIHR Blood and Transplant Research Unit (BTRU) in Donor Health and Genomics (NIHR BTRU-2014-10024). The academic coordinating centre for COMPARE was supported by core funding from: NIHR BTRU, UK Medical Research Council (MR/L003120/1), British Heart Foundation (RG/13/13/30194) and the NIHR [Cambridge Biomedical Research Centre at the Cambridge University Hospitals NHS Foundation Trust]. This work was supported by Health Data Research UK, which is funded by the UK Medical Research Council, Engineering and Physical Sciences Research Council, Economic and Social Research Council, Department of Health and Social Care (England), Chief Scientist Office of the Scottish Government Health and Social Care Directorates, Health and Social Care Research and Development Division (Welsh Division), Public Health Agency (Northern Ireland), British Heart Foundation and Wellcome. JD holds a British Heart Foundation Professorship and a National Institute for Health Research Senior Investigator Award. The views expressed are those of the author(s) and not necessarily those of the NHS, NIHR or the Department of Health and Social Care