Fission track dating of detrital zircons from the Scotland Sandstones, Barbados, West Indies

Results of fission track dating of detrital zircons from the Scotland sandstones, Barbados, yield a mixture of ages with several strong groupings from 20-80 Ma, 200-350 Ma, and greater than 500 Ma. Metamict grains were assumed to fall into the greater than 500 Ma population. The youngest population indicates that the Scotland beds, previously dated by paleontologic methods as Eocene, may actually be as young as late Oligocene. These ages better constrain the timing of deposition for these sediments and support the proposal that the late middle Eocene - early Oligocene Oceanic Fm has overthrust the Scotland beds. This population (20-80 Ma) may reflect material derived from the adjacent arc, the Netherland-Venezuelan Antilles arc, and the Caribbean Mountains of Venezuela. The 200-350 Ma population may reflect partially annealed cratonic material, an Andean component, and/or material associated with a Triassic rifting event. The oldest population (\u3e500 Ma) and metamict zircons were very likely derived from the South American craton. 40Ar/39Ar age spectrum analysis of detrital feldspar from sample 22 provides additional evidence of a cratonic source for these sediments. Based on results from this study, distribution of glaucophane, and paleogeographical constraints it is proposed that the source area for the Scotland sediments of Barbados was an area of the Guayana shield which was drained by the Unare (proto-Orinoco?) river system and deposited in a submarine fan north of the Unare depression

Fission track dating of detrital zircons from the Scotland Sandstones, Barbados, West Indies

Results of fission track dating of detrital zircons from the Scotland sandstones, Barbados, yield a mixture of ages with several strong groupings from 20-80 Ma, 200-350 Ma, and greater than 500 Ma. Metamict grains were assumed to fall into the greater than 500 Ma population. The youngest population indicates that the Scotland beds, previously dated by paleontologic methods as Eocene, may actually be as young as late Oligocene. These ages better constrain the timing of deposition for these sediments and support the proposal that the late middle Eocene - early Oligocene Oceanic Fm has overthrust the Scotland beds. This population (20-80 Ma) may reflect material derived from the adjacent arc, the Netherland-Venezuelan Antilles arc, and the Caribbean Mountains of Venezuela. The 200-350 Ma population may reflect partially annealed cratonic material, an Andean component, and/or material associated with a Triassic rifting event. The oldest population (\u3e500 Ma) and metamict zircons were very likely derived from the South American craton. 40Ar/39Ar age spectrum analysis of detrital feldspar from sample 22 provides additional evidence of a cratonic source for these sediments. Based on results from this study, distribution of glaucophane, and paleogeographical constraints it is proposed that the source area for the Scotland sediments of Barbados was an area of the Guayana shield which was drained by the Unare (proto-Orinoco?) river system and deposited in a submarine fan north of the Unare depression

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Antenatal risk factors for child maltreatment : linkage of data from a birth cohort study to child welfare records

Background Understanding the risk factors for child maltreatment is critical to efforts to reduce its prevalence. Objective This study investigated the association between characteristics and circumstances of mothers during pregnancy and the subsequent identification of concerns about child maltreatment. Participants and setting The study drew on two data sets: (i) data from questionnaires administered to the expectant mothers of 11,332 children born in a deprived multi-ethnic local authority in England between 2007 and 2011, for a birth cohort study, and (ii) administrative data on children referred to child welfare services. Methods The linkage of these two pre-existing data sets enabled the prospective study of risk factors for child maltreatment. Results A range of factors captured during the antenatal period were associated with an increased likelihood of subsequent recorded child maltreatment concerns, including: younger maternal age (HR=0.96; p < .001), lower maternal education level (HR=1.36; p < .001), maternal mental illness (HR=1.17; p = .001), maternal smoking in pregnancy (HR=1.69; p < .001), single motherhood (HR=1.41; p = .022), larger family size (HR=1.13; p < .001), multiple deprivation (HR=1.01; p = .011), social housing (HR=1.72; p < .001), paternal unemployment (HR=1.79; p < .001), and the receipt of means-tested welfare benefits (HR=1.43; p < .001). A greater total number of risk factors during pregnancy also increased the risk of subsequent maltreatment concerns (HR=1.45; p < .001). Conclusions The identification of multiple risk factors in this study supports claims that single targeted interventions are unlikely to be successful in preventing or reducing child maltreatment due to its multifactorial nature, and that multidimensional interventions are required