Remote Measurements of Tides and River Slope Using an Airborne Lidar Instrument

Tides and river slope are fundamental characteristics of estuaries, but they are usually undersampled due to deficiencies in the spatial coverage of water level measurements. This study aims to address this issue by investigating the use of airborne lidar measurements to study tidal statistics and river slope in the Columbia River estuary. Eight plane transects over a 12-h period yield at least eight independent measurements of water level at 2.5-km increments over a 65-km stretch of the estuary. These data are fit to a sinusoidal curve and the results are compared to seven in situ gauges. In situ– and lidar-based tide curves agree to within a root-mean-square error of 0.21 m, and the lidar-based river slope estimate of 1.8 × 10−5 agrees well with the in situ–based estimate of 1.4 × 10−5 (4 mm km−1 difference). Lidar-based amplitude and phase estimates are within 10% and 8°, respectively, of their in situ counterparts throughout most of the estuary. Error analysis suggests that increased measurement accuracy and more transects are required to reduce the errors in estimates of tidal amplitude and phase. However, the results validate the use of airborne remote sensing to measure tides and suggest this approach can be used to systematically study water levels at a spatial density not possible with in situ gauges

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

Genomic investigations of unexplained acute hepatitis in children

Since its first identification in Scotland, over 1,000 cases of unexplained paediatric hepatitis in children have been reported worldwide, including 278 cases in the UK1. Here we report an investigation of 38 cases, 66 age-matched immunocompetent controls and 21 immunocompromised comparator participants, using a combination of genomic, transcriptomic, proteomic and immunohistochemical methods. We detected high levels of adeno-associated virus 2 (AAV2) DNA in the liver, blood, plasma or stool from 27 of 28 cases. We found low levels of adenovirus (HAdV) and human herpesvirus 6B (HHV-6B) in 23 of 31 and 16 of 23, respectively, of the cases tested. By contrast, AAV2 was infrequently detected and at low titre in the blood or the liver from control children with HAdV, even when profoundly immunosuppressed. AAV2, HAdV and HHV-6 phylogeny excluded the emergence of novel strains in cases. Histological analyses of explanted livers showed enrichment for T cells and B lineage cells. Proteomic comparison of liver tissue from cases and healthy controls identified increased expression of HLA class 2, immunoglobulin variable regions and complement proteins. HAdV and AAV2 proteins were not detected in the livers. Instead, we identified AAV2 DNA complexes reflecting both HAdV-mediated and HHV-6B-mediated replication. We hypothesize that high levels of abnormal AAV2 replication products aided by HAdV and, in severe cases, HHV-6B may have triggered immune-mediated hepatic disease in genetically and immunologically predisposed children

Remote Sensing of Water Surface Variability Near River Mouths

Thesis (Ph.D.)--University of Washington, 2020Rivers discharge approximately 1,000,000 cubic meters per second of freshwater to the oceans yet less than 60% of this discharge is measured at the river mouth. The standard method of measuring river discharge is to use in-situ current meters that are expensive to deploy and not easily used at remote locations. Remote sensing of river discharge could address the problem of global coverage and is becoming an active area of research due to the recent and upcoming improvements of the resolution of satellite altimeters, including the Surface Water and Ocean Topography (SWOT) altimeter. Remote measurements of river discharge have been made from altimeter type water surface elevation data before but only far upstream where the flow is uniform. In order to accurately quantify the amount of freshwater being discharged into the ocean the discharge measurement must be made at the river mouth where the flow is not uniform and the relationship between water surface elevation and discharge is not well understood. This dissertation uses airborne Lidar data, numerical model output, and new analytical expressions to characterize the relationships between river discharge, water surface elevation, tides, and bathymetry at and near the river mouth. It is found that the slope of the water surface elevation at the mouth of the Columbia River changes sign over the tidal period and that wave amplification increases with river flow velocity. Numerical model output of an idealized river discharge describes the shape of the water surface elevation near the river mouth under both low and high discharge conditions. During high discharge conditions an offshore ridge develops on the water surface whose location and height are related to river discharge. Equations are derived to calculate the location and height of the ridge and relate these signatures to the river discharge. These relationships are then used to predict whether the upcoming SWOT altimeter will be able to detect the ridge for flow from the Mississippi, Connecticut, and Columbia Rivers. This research provides an understanding of how water surface elevation changes at the river mouth are related to tides, waves, and discharge and quantifies which of these signals will be observable by SWOT. Finally, remotely sensed infrared videos of the surface are used to infer the bottom drag coefficient in a river. The surface turbulent kinetic energy is extracted from the videos and an equation is derived to calculate the river bottom drag coefficient from the turbulent kinetic energy. The equation is tested with field data from six locations in the Snohomish River and the drag coefficients calculated compare well with drag coefficients calculated from in situ velocity data. In the future, the turbulent kinetic energy equation for the drag coefficient and remote sensing techniques presented here could be applied to data from unmanned aerial vehicles and used in the surf zone

Students Learn about Documentation throughout Their Teacher Education Program

Study groups and learning circles can offer a systematic way for early childhood teachers to interact about their work and create a culture of professional development. This paper describes how faculty systematically followed a collaborative co-inquiry process in order to improve a new early childhood interdisciplinary teacher preparation program. The team met on a regular basis throughout one academic year, with the stated objective of infusing observation/documentation knowledge and skills in a coherent and systematic way throughout the students’ program of studies. The group created a template of the cycle of inquiry, which could apply to all courses, and analyzed the documentation process along a series of skill dimensions: (1) level that students are expected to achieve (awareness, application, refinement/integration); (2) focus of the students’ observations (who, what, where, when, how); (3) width of the lens of observation (e.g., focused narrowly on one dimension of behavior or widely on a whole classroom environment); (4) intended audience of the completed documentation (e.g., children, parents, professional colleagues); and (5) finished product of documentation (e.g., project panel, memory book, slide presentation). The co-inquiry process allowed the faculty to improve the ways that the program helps students move from an awareness level toward a practitioner level in using observation and documentation. The students’ reflections and finished work suggest how they learned to promote children’s learning, partner with parents, and come to think of themselves as “professionals” in their field

Laboratory Heat Flux Estimates of Seawater Foam for Low Wind Speeds

Laboratory experiments were conducted to measure the heat flux from seafoam continuously generated in natural seawater. Using a control volume technique, heat flux was calculated from foam and foam-free surfaces as a function of ambient humidity (ranged from 40% to 78%), air–water temperature difference (ranged from −9 °C to 0 °C), and wind speed (variable up to 3 m s−1). Water-surface skin temperature was imaged with a calibrated thermal infrared camera, and near-surface temperature profiles in the air, water, and foam were recorded. Net heat flux from foam surfaces increased with increasing wind speed and was shown to be up to four times greater than a foam-free surface. The fraction of the total heat flux due to the latent heat flux was observed for foam to be 0.75, with this value being relatively constant with wind speed. In contrast, for a foam-free surface the fraction of the total heat flux due to the latent heat flux decreased at higher wind speeds. Temperature profiles through foam are linear and have larger gradients, which increased with wind speed, while foam free surfaces show the expected logarithmic profile and show no variation with temperature. The radiometric surface temperatures show that foam is cooler and more variable than a foam-free surface, and bubble-resolving thermal images show that radiometrically transparent bubble caps and burst bubbles reveal warm foam below the cool surface layer, contributing to the enhanced variability

Tobacco consumption in Darwin, October 1994

This publication is largely based on the results of a survey conducted by the Australian Bureau of Statistics (ABS) in the Northern Territory as a supplement to the monthly population survey in October 1994. The ABS has previously conducted surveys on tobacco consumption in the Northern Territory in October 1986 and in October 1990. Results of the latest survey presented in this publication highlight the changes that have happened across this period. This report aims to present the findings in a way that is informative, easy to read and easy to understand. The relatively small and dispersed nature of the Territory's population and the small sample size (approximately 0.8 percent) have meant that the analysis has been limited to the Darwin urban statistical division. Further, tobacco consumption by Aboriginal people was not examined within this survey. Despite these restrictions, the results are worthwhile and give us a good understanding of tobacco consumption in Darwin