A large-area, spatially continuous assessment of land cover map error and its impact on downstream analyses.

Land cover maps increasingly underlie research into socioeconomic and environmental patterns and processes, including global change. It is known that map errors impact our understanding of these phenomena, but quantifying these impacts is difficult because many areas lack adequate reference data. We used a highly accurate, high-resolution map of South African cropland to assess (1) the magnitude of error in several current generation land cover maps, and (2) how these errors propagate in downstream studies. We first quantified pixel-wise errors in the cropland classes of four widely used land cover maps at resolutions ranging from 1 to 100 km, and then calculated errors in several representative "downstream" (map-based) analyses, including assessments of vegetative carbon stocks, evapotranspiration, crop production, and household food security. We also evaluated maps' spatial accuracy based on how precisely they could be used to locate specific landscape features. We found that cropland maps can have substantial biases and poor accuracy at all resolutions (e.g., at 1 km resolution, up to ∼45% underestimates of cropland (bias) and nearly 50% mean absolute error (MAE, describing accuracy); at 100 km, up to 15% underestimates and nearly 20% MAE). National-scale maps derived from higher-resolution imagery were most accurate, followed by multi-map fusion products. Constraining mapped values to match survey statistics may be effective at minimizing bias (provided the statistics are accurate). Errors in downstream analyses could be substantially amplified or muted, depending on the values ascribed to cropland-adjacent covers (e.g., with forest as adjacent cover, carbon map error was 200%-500% greater than in input cropland maps, but ∼40% less for sparse cover types). The average locational error was 6 km (600%). These findings provide deeper insight into the causes and potential consequences of land cover map error, and suggest several recommendations for land cover map users.

Mobile Extracorporeal Membrane Oxygenation for Covid-19 Does Not Pose Extra Risk to Transport Team.

Previous experience has shown that transporting patients on extracorporeal membrane oxygenation (ECMO) is a safe and effective mode of transferring critically ill patients requiring maximum mechanical ventilator support to a quaternary care center. The coronavirus disease 2019 (COVID-19) pandemic posed new challenges. This is a multicenter, retrospective study of 113 patients with confirmed severe acute respiratory syndrome coronavirus 2, cannulated at an outside hospital and transported on ECMO to an ECMO center. This was performed by a multidisciplinary mobile ECMO team consisting of physicians for cannulation, critical care nurses, and an ECMO specialist or perfusionist, along with a driver or pilot. Teams practised strict airborne contact precautions with eyewear while caring for the patient and were in standard Personal Protective Equipment. The primary mode of transportation was ground. Ten patients were transported by air. The average distance traveled was 40 miles (SD ±56). The average duration of transport was 133 minutes (SD ±92). When stratified by mode of transport, the average distance traveled for ground transports was 36 miles (SD ±52) and duration was 136 minutes (SD ±93). For air, the average distance traveled was 66 miles (SD ±82) and duration was 104 minutes (SD ±70). There were no instances of transport-related adverse events including pump failures, cannulation complications at outside hospital, or accidental decannulations or dislodgements in transit. There were no instances of the transport team members contracting COVID-19 infection within 21 days after transport. By adhering to best practices and ACE precautions, patients with COVID-19 can be safely cannulated at an outside hospital and transported to a quaternary care center without increased risk to the transport team.

From Fad to Fact: Evaluating the Impact of Emerging Diets on the Prevention of Cardiovascular Disease.

Cardiovascular disease remains one of the most prevalent and preventable chronic conditions worldwide. Diet modification is the foundation of cardiovascular disease prevention. Several dietary approaches have emerged to promote better cardiovascular health. The rapid dissemination of anecdotal and observational data through the internet and social media has caused confusion amongst providers and patients. The aim of this comprehensive review is to present objective insights into 2 of today's most popular fad diets: ketogenic diet and intermittent fasting. We will evaluate the performance of these diets based on their impact on cardiovascular risk factors.