525 research outputs found
The Reference Elevation Model of Antarctica
The Reference Elevation Model of Antarctica (REMA) is the
first continental-scale digital elevation model (DEM) at a resolution of
less than 10 m. REMA is created from stereophotogrammetry with submeter
resolution optical, commercial satellite imagery. The higher spatial and
radiometric resolutions of this imagery enable high-quality surface
extraction over the low-contrast ice sheet surface. The DEMs are registered
to satellite radar and laser altimetry and are mosaicked to provide a
continuous surface covering nearly 95 % the entire continent. The mosaic
includes an error estimate and a time stamp, enabling change measurement.
Typical elevation errors are less than 1 m, as validated by the
comparison to airborne laser altimetry. REMA provides a powerful new
resource for Antarctic science and provides a proof of concept for
generating accurate high-resolution repeat topography at continental
scales.</p
Християнство і європейська духовно-культурна ідентичність
Стаття присвячена з’ясуванню ролі і місця християнства у формуванні європейської ідентичності в
умовах ціннісної дезорієнтації, дегуманізації людини і суспільства, морального та релігійного хаосу.Статья посвящена выяснению роли и места христианства в формировании европейской идентичности в
условиях ценностной дезориентации, дегуманизации человека и общества, морального и религиозного хаоса.The article is devoted to finding out the role and place of christianity in forming of the European identity in the
conditions of the valued disorientation, dehumanizing of man and society, moral and religious chaos
A marine plasmid hitchhiking vast phylogenetic and geographic distances
Horizontal gene transfer (HGT) plays an important role in bacterial evolution and serves as a driving force for bacterial diversity and versatility. HGT events often involve mobile genetic elements like plasmids, which can promote their own dissemination by associating with adaptive traits in the gene pool of the so-called mobilome. Novel traits that evolve through HGT can therefore lead to the exploitation of new ecological niches, prompting an adaptive radiation of bacterial species. In this study, we present phylogenetic, biogeographic, and functional analyses of a previously unrecognized RepL-type plasmid found in diverse members of the marine Roseobacter group across the globe. Noteworthy, 100% identical plasmids were detected in phylogenetically and geographically distant bacteria, revealing a so-far overlooked, but environmentally highly relevant vector for HGT. The genomic and functional characterization of this plasmid showed a completely conserved backbone dedicated to replication, stability, and mobilization as well as an interchangeable gene cassette with highly diverse, but recurring motifs. The majority of the latter appear to be involved in mechanisms coping with toxins and/or pollutants in the marine environment. Furthermore, we provide experimental evidence that the plasmid has the potential to be transmitted across bacterial orders, thereby increasing our understanding of evolution and microbial niche adaptation in the environment
Graphomotor skills in children with prenatal alcohol exposure and fetal alcohol spectrum disorder: A population-based study in remote Australia
Background/aim: Few studies have examined graphomotor skills in children with prenatal alcohol exposure (PAE) or fetal alcohol spectrum disorder (FASD). Methods: Graphomotor skills were assessed in 108 predominantly Australian Aboriginal children aged 7.5-9.6 years in remote Western Australia using clinical observations (pencil grasp; writing pressure) and standardised assessment tools (the Evaluation Tool of Children's Handwriting; and the Miller Function and Participation Scales - The Draw-a-Kid Game). Skills were compared between children (i) without PAE, (ii) PAE but not FASD and (iii) FASD. Results: Most children used a transitional pencil grasp and exerted heavy handwriting pressure (83.3% and 30.6% of the cohort). The percentage of letters (M = 62.9%) and words (M = 73.3%) written legibly was low. Children with FASD were more likely than children without PAE to use a cross-thumb grasp (P = 0.027), apply heavy writing pressure (P = 0.036), be unable to write a sentence (P = 0.041) and show poorer word legibility (P = 0.041). There were no significant differences between groups for drawing outcomes, although some children with FASD drew pictures that appeared delayed for their age. There were no significant differences between children without PAE and those with PAE but who were not diagnosed with FASD. Conclusions: Overall, graphomotor skills were poor in this cohort, but children with FASD performed significantly worse than children without PAE. Findings suggest the need for improved occupational therapy services for children in remote regions and evaluation of graphomotor skills in children with PAE. © 2016 Occupational Therapy Australia
Winter mass balance of Drangajökull ice cap (NW Iceland) derived from satellite sub-meter stereo images
Sub-meter resolution, stereoscopic satellite images allow for the generation of accurate and high-resolution digital elevation models (DEMs) over glaciers and ice caps. Here, repeated stereo images of Drangajökull ice cap (NW Iceland) from Pléiades and WorldView2 (WV2) are combined with in situ estimates of snow density and densification of firn and fresh snow to provide the first estimates of the glacier-wide geodetic winter mass balance obtained from satellite imagery. Statistics in snow- and ice-free areas reveal similar vertical relative accuracy (< 0.5 m) with and without ground control points (GCPs), demonstrating the capability for measuring seasonal snow accumulation. The calculated winter (14 October 2014 to 22 May 2015) mass balance of Drangajökull was 3.33 ± 0.23 m w.e. (meter water equivalent), with ∼ 60 % of the accumulation occurring by February, which is in good agreement with nearby ground observations. On average, the repeated DEMs yield 22 % less elevation change than the length of eight winter snow cores due to (1) the time difference between in situ and satellite observations, (2) firn densification and (3) elevation changes due to ice dynamics. The contributions of these three factors were of similar magnitude. This study demonstrates that seasonal geodetic mass balance can, in many areas, be estimated from sub-meter resolution satellite stereo images.This study was funded by the University of Iceland (UI) Research Fund. Pleiades images were acquired at research price thanks to the CNES ISIS program (http://www.isis-cnes.fr). The WV2 DEM was obtained through the ArcticDEM project. This work is a contribution to the Rannis grant of excellence project, ANATILS. Collaboration and travels between IES and LEGOS were funded by the Jules Verne research fund and the TOSCA program from the French Space Agency, CNES. This study used the recent lidar mapping of the glaciers in Iceland that was funded by the Icelandic Research Fund, the Landsvirkjun research fund, the Icelandic Road Administration, the Reykjavik Energy Environmental and Energy Research Fund, the Klima-og Luftgruppen (KoL) research fund of the Nordic Council of Ministers, the Vatnajokull National Park, the organization Friends of Vatnajokull, the National Land Survey of Iceland, the Icelandic Meteorological Office and the UI research fund. The ground-based mass balance measurements on Drangajokull have been jointly funded by Orkubu Vestfjarda (Westfjord Power Company), the National Energy Authority (2004-2009) and the Icelandic Meteorological Office (2009-2015).Peer Reviewe
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