457 research outputs found
Geotechnical properties of Antarctic deep sea sediments
Sedimentological and geotechnical analyses were carried out on two undisturbed large diameter deep sea cores from the Antarctic sector of the Atlantic ocean. One core, from a silled basin within the Bransfield Strait is characterized by fine grained hemipelagic material and turbidite layers. The other core, from the continental slope of the Weddell Sea represents a typical glacial marine environment. The variations of physical properties as related to both an increasing overburden pressure (or depth below top of core) and/or to lithological changes are discussed. With increasing overburden pressure only small variations of physical properties were observed. In core 14882-2 the porosity decreases 0.7% per meter, the natural water content 6% per meter. The wet bulk density and the shear strength increase with rates of 0.015 g/cm3 and 0.5 KPa per meter. Compared to small variations in consolidation, the changes of the lithology cause more extreme variations of physical properties: e.g. decreases the natural water content by 100%, the porosity by 14%, and the wet bulk density increases by 0.23 g/cm3 due to a turbidite layer in the core from the Bransfield Strait (core 14882-2). In the core from the continental slope of the Weddell Sea (core 14875-1) two major unconformities have been detected. The ice-rafted debris of this core causes a generally lower porosity (64%), a lower natural water content (75%), a higher wet bulk density (1.55 g/cm3) and specific grain density (2.62 g/cm3), compared to the core from the Bransfield Strait (porosity 77% , natural water content 151% , wet bulk density 1.34 g/cm3, specific grain density 2.47 g/cm3)
Electrophysiological and kinematic correlates of communicative intent in the planning and production of pointing gestures and speech
Acknowledgements We thank Albert Russel for assistance in setting up the experiments, and Charlotte Paulisse for help in data collection.Peer reviewedPublisher PD
AL520-2 Cruise summary report [AL520/2]
Cruise period: 20.3.2019 - 4.4.2019
Alkor cruise 520-2 was part of the project ASKAWZ (Acoustic Seafloor Classification of the German EEZ) funded by the Federal Maritime and Hydrographic Agency (BSH) and the Feral Agency for Nature Conservation (BfN). The main goal of the cruise was the full area acoustic mapping of the westernmost part of the German EEZ (so called âduck billâ) by sidescan sonar and the detection of natural and man-made structures (trawl marks) on the seafloor. The full area mapping was achieved by 61 sidescan sonar profiles, covering an area of ca. 640 kmÂČ. A single-beam echosounder with automatic seafloor classification (QTC 5.5) was run simultaneously to the sidescan sonar. The acoustic backscatter data was âground truthedâ using Shipek grab and Box-corer (Reineck-Type) samples. In addition an underwater video camera was used to gather further seabed information.
Aditionally sidescan data was recorded in the Helgoland-Reef pockmark area. Here 13 lines were surveyed (ca. 10 kmÂČ) by sidescan sonar in order to document the development of the pockmark field
Decentralized Infrastructure for Reproducible and Replicable Geographical Science
The I-GUIDE cyberinfrastructure project for convergence science is a leading example of the possibilities the geospatial data revolution holds for scientific discovery. However, rapidly expanding access to increasingly complex data sources and methods of computational analysis also presents a challenge to the research community. With more data and more potential analyses, researchers face the possibility of jeopardizing the inferential power of convergence research with selection bias. Well-designed infrastructure that can flexibly guide researchers as they record and track decisions in their research designs opens a path to mitigating this problem, while also expanding the reproducibility and replicability of research. Much of the infrastructure needed for convergence research can be borrowed and adapted from other disciplines, but geographic convergence research confronts at least five novel challenges. These are the need for geographically-explicit project metadata, managing diverse and complex data inputs, handling restricted data, specifying and reproducing computational environments, and disclosing researcher decisions and threats to validity that are unique to geographic research. We introduce a template research compendium and analysis plan for study preregistration to address these novel challenges
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Election campaigns, agenda setting and electoral outcomes
Framing effects and bounded rationality imply that election campaigns may be an important determinant of election outcomes. This paper uses a two-party setting and simple game theoretic models to analyse the strategic interaction between the partiesâ campaign decisions. Alternations of power emerge naturally, even if both electoral preferences and party positions remain constant
Validation of an automated enzyme immunoassay for interleukin-6 for routine clinical use
Serum levels of Interleukin-6 (IL-6), a proinflammatory cytokine, are increased in early stages of inflammatory diseases such as infection and sepsis. Assay systems which permit its measurement within a few hours and as a single measurement have not been reported so far. We therefore evaluated a now commercially available automated method for IL-6 measurement on the Cobas Core(R) immunological analyzer (Roche Diagnostic Systems) which enables single IL-6 measurement within about 1 hour. The automated assay correlates well with an established, manual microtiter plate assay (Biosource GmbH) which uses the same antibodies and reagents (r=0.98). Accuracy of the automated method was established by adding known amounts of IL-6 international reference preparation. Recovery of the international standard was in the range of 92-104%. The automated assay had a precision of singletons below 6% and was linear up to 2800 pg/ml. This automated assay provides a suitable, convenient and time saving method for measurement of IL-6 serum levels in the routine clinical laboratory
High energy astroparticle physics for high school students
The questions about the origin and type of cosmic particles are not only
fascinating for scientists in astrophysics, but also for young enthusiastic
high school students. To familiarize them with research in astroparticle
physics, the Pierre Auger Collaboration agreed to make 1% of its data publicly
available. The Pierre Auger Observatory investigates cosmic rays at the highest
energies and consists of more than 1600 water Cherenkov detectors, located near
Malarg\"{u}e, Argentina. With publicly available data from the experiment,
students can perform their own hands-on analysis. In the framework of a
so-called Astroparticle Masterclass organized alongside the context of the
German outreach network Netzwerk Teilchenwelt, students get a valuable insight
into cosmic ray physics and scientific research concepts. We present the
project and experiences with students.Comment: 8 pages, 5 figures, Proceedings of the 34th International Cosmic Ray
Conference (ICRC2015), The Hague, The Netherlands, PoS(ICRC2015)30
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