High-latitude dust in the Earth system

Natural dust is often associated with hot, subtropical deserts, but significant dust events have been reported from cold, high latitudes. This review synthesizes current understanding of high-latitude (≥50°N and ≥40°S) dust source geography and dynamics and provides a prospectus for future research on the topic. Although the fundamental processes controlling aeolian dust emissions in high latitudes are essentially the same as in temperate regions, there are additional processes specific to or enhanced in cold regions. These include low temperatures, humidity, strong winds, permafrost and niveo-aeolian processes all of which can affect the efficiency of dust emission and distribution of sediments. Dust deposition at high latitudes can provide nutrients to the marine system, specifically by contributing iron to high-nutrient, low-chlorophyll oceans; it also affects ice albedo and melt rates. There have been no attempts to quantify systematically the expanse, characteristics, or dynamics of high-latitude dust sources. To address this, we identify and compare the main sources and drivers of dust emissions in the Northern (Alaska, Canada, Greenland, and Iceland) and Southern (Antarctica, New Zealand, and Patagonia) Hemispheres. The scarcity of year-round observations and limitations of satellite remote sensing data at high latitudes are discussed. It is estimated that under contemporary conditions high-latitude sources cover >500,000 km2 and contribute at least 80–100 Tg yr−1 of dust to the Earth system (~5% of the global dust budget); both are projected to increase under future climate change scenarios

The development and validation of a scoring tool to predict the operative duration of elective laparoscopic cholecystectomy

Background: The ability to accurately predict operative duration has the potential to optimise theatre efficiency and utilisation, thus reducing costs and increasing staff and patient satisfaction. With laparoscopic cholecystectomy being one of the most commonly performed procedures worldwide, a tool to predict operative duration could be extremely beneficial to healthcare organisations. Methods: Data collected from the CholeS study on patients undergoing cholecystectomy in UK and Irish hospitals between 04/2014 and 05/2014 were used to study operative duration. A multivariable binary logistic regression model was produced in order to identify significant independent predictors of long (> 90 min) operations. The resulting model was converted to a risk score, which was subsequently validated on second cohort of patients using ROC curves. Results: After exclusions, data were available for 7227 patients in the derivation (CholeS) cohort. The median operative duration was 60 min (interquartile range 45–85), with 17.7% of operations lasting longer than 90 min. Ten factors were found to be significant independent predictors of operative durations > 90 min, including ASA, age, previous surgical admissions, BMI, gallbladder wall thickness and CBD diameter. A risk score was then produced from these factors, and applied to a cohort of 2405 patients from a tertiary centre for external validation. This returned an area under the ROC curve of 0.708 (SE = 0.013, p  90 min increasing more than eightfold from 5.1 to 41.8% in the extremes of the score. Conclusion: The scoring tool produced in this study was found to be significantly predictive of long operative durations on validation in an external cohort. As such, the tool may have the potential to enable organisations to better organise theatre lists and deliver greater efficiencies in care

Ecology of a Recently Discovered Population Segment of Blanding’s Turtles, Emydoidea blandingii, in Barren Meadow and Keddy Brooks, Nova Scotia

Blanding’s Turtles in Barren Meadow Brook and Keddy Brook are part of the Pleasant River population, the easternmost population currently recognized in Nova Scotia. Previous genetic analysis demonstrated restricted gene flow among the populations of Nova Scotia. The conservation of this genetic diversity is important to reduce genetic drift and bottleneck effects in these populations. Between 2006 and 2008, the population in Barren Meadow Brook and Keddy Brook was estimated using visual surveys, trapping, and radio-tracking. Over the three years, surveys yielded 69 individuals (14 females, 22 males, 29 juveniles, 4 undetermined). Capture-mark-recapture analysis using the Chapman variation of Petersen formulas for bi-census yielded population estimates of 88 Blanding’s Turtles. The sex ratio did not deviate significantly from 1:1. Applying minimum convex polygon (MCP) and kernel methods to radio-tracking data yielded preliminary estimates of home range size and location for males and females. Females had larger homes ranges, probably because of the limited availability of nesting sites in Barren Meadow and Keddy Brooks. New overwintering sites and three new nesting sites were identified. Home ranges of males did not overlap, and males seemed to show territorial behaviour. An expanded sample, particularly of males, is needed to improve the assessment of home ranges, movements, and behaviour. To date, conservation efforts in this population have focused on females. If home ranges of males in an expanded sample also do not overlap, then conservation of this population requires closer scrutiny of males and their population genetic structure

Seasonal and decadal variability of dust observations in the Kangerlussuaq area, west Greenland

Dust emissions from high-latitude, cold-climate environments have started receiving more attention in the past decade. This is because emission frequency and magnitudes are expected to increase with rising global temperatures, leading to a reduction in terrestrial ice masses and increases in suitable sediment for the aeolian system. Of the identified high-latitude dust source regions, Greenland has received relatively little attention. Using World Meteorological Organization (WMO) dust-code analysis, this study presents a seventy-year record of dust events and preferential dust transport pathways from Kangerlussuaq, west Greenland. A clear seasonal pattern of dust emissions shows increases in dust events in spring and autumn driven by effective winds and sediment supply. The decadal record suggests an increase in the magnitude, but not frequency, of dust events since the early 1990s. Pathways analysis suggests that dust is preferentially transported away from the Greenland Ice Sheet (GrIS) toward the Davis Strait and Labrador Sea. When dust is transported toward the GrIS, it is more likely to be deposited in the ice-marginal ablation zone than on the higher altitude areas of the ice sheet. The impact of dust deposition on terrestrial, cryospheric, and aquatic environments is also discussed

Biodiversity inventories in high gear: DNA barcoding facilitates a rapid biotic survey of a temperate nature reserve

International audienc

Biodiversity inventories in high gear:DNA barcoding facilitates a rapid biotic survey of a temperate nature reserve

Abstract Background: Comprehensive biotic surveys, or ‘all taxon biodiversity inventories’ (ATBI), have traditionally been limited in scale or scope due to the complications surrounding specimen sorting and species identification. To circumvent these issues, several ATBI projects have successfully integrated DNA barcoding into their identification procedures and witnessed acceleration in their surveys and subsequent increase in project scope and scale. The Biodiversity Institute of Ontario partnered with the rare Charitable Research Reserve and delegates of the 6th International Barcode of Life Conference to complete its own rapid, barcode-assisted ATBI of an established land trust in Cambridge, Ontario, Canada. New information: The existing species inventory for the rare Charitable Research Reserve was rapidly expanded by integrating a DNA barcoding workflow with two surveying strategies — a comprehensive sampling scheme over four months, followed by a one-day bioblitz involving international taxonomic experts. The two surveys resulted in 25,287 and 3,502 specimens barcoded, respectively, as well as 127 human observations. This barcoded material, all vouchered at the Biodiversity Institute of Ontario collection, covers 14 phyla, 29 classes, 117 orders, and 531 families of animals, plants, fungi, and lichens. Overall, the ATBI documented 1,102 new species records for the nature reserve, expanding the existing long-term inventory by 49%. In addition, 2,793 distinct Barcode Index Numbers (BINs) were assigned to genus or higher level taxonomy, and represent additional species that will be added once their taxonomy is resolved. For the 3,502 specimens, the collection, sequence analysis, taxonomic assignment, data release and manuscript submission by 100+ co-authors all occurred in less than one week. This demonstrates the speed at which barcode-assisted inventories can be completed and the utility that barcoding provides in minimizing and guiding valuable taxonomic specialist time. The final product is more than a comprehensive biotic inventory — it is also a rich dataset of fine-scale occurrence and sequence data, all archived and cross-linked in the major biodiversity data repositories. This model of rapid generation and dissemination of essential biodiversity data could be followed to conduct regional assessments of biodiversity status and change, and potentially be employed for evaluating progress towards the Aichi Targets of the Strategic Plan for Biodiversity 2011–2020