Is functional status better in U.S. patients with cardiac disease than in their Canadian counterparts?

The raw images (available on request) have been captured using a Canon 8-15mm fisheye lens and therefore they have a wide field of view, which results in a dark image boundary as the lights did not illuminate the outer sectors well. The images in this dataset have then been undistorted to virtual images that an ideal perspective camera with only 90 degrees horizontal field of view would have seen from the same position. To achieve this, the color of each pixel in the ideal image is obtained by - computing the ray in space associated with this virtual pixel (using rectilinear un-projection) - projecting this ray into the original fisheye image (using equidistant projection), yielding a sub-pixel position - interpolating the colors of the neighboring pixels Technically, the undistortion has been performed using the tool https://svn.geomar.de/dsm-general/trunk/src/BIAS/Tools/biasproject.cpp (at revision 418, and earlier, compatible revisions). Manual image annotation is available here: https://annotate.geomar.de/volumes/24

RV ALKOR Fahrtbericht / Cruise Report AL533 - Mutual Field Trials of the Manned Submersible JAGO and the Hover-AUVs ANTON and LUISE off the Aeolian Islands, Mediterranean Sea, Catania (Italy) – La Seyne-sur-mer (France) 05.02. – 18.02.2020

The tight program of scientific research cruises usually does not leave enough time for thorough tests of new research equipment and their system components, nor for extensive pilot and handling training. For this reason, ship time was requested for sea trials of two types of autonomous (not tethered) underwater vehicles owned by GEOMAR, the manned 400-meter submersible JAGO and the Hover-AUVs ANTON and LUISE, type Girona500. The aim was to test several technical and operational aspects with both vehicles at locations with differently structured terrain (from flat ground to steep rocky slopes) and to water depths of up to 500 meters. The Aeolian Islands in the Tyrrhenian Sea north of Sicily were chosen as test area. The volcanic islands offer sheltered sea conditions at their leeway, and bottom currents are usually weak or absent. Rocky and steep slopes are located in short distances to areas with flat underwater topography, providing ideal test conditions

DeepSurveyCam — A Deep Ocean Optical Mapping System

Underwater photogrammetry and in particular systematic visual surveys of the deep sea are by far less developed than similar techniques on land or in space. The main challenges are the rough conditions with extremely high pressure, the accessibility of target areas (container and ship deployment of robust sensors, then diving for hours to the ocean floor), and the limitations of localization technologies (no GPS). The absence of natural light complicates energy budget considerations for deep diving flash-equipped drones. Refraction effects influence geometric image formation considerations with respect to field of view and focus, while attenuation and scattering degrade the radiometric image quality and limit the effective visibility. As an improvement on the stated issues, we present an AUV-based optical system intended for autonomous visual mapping of large areas of the seafloor (square kilometers) in up to 6000 m water depth. We compare it to existing systems and discuss tradeoffs such as resolution vs. mapped area and show results from a recent deployment with 90,000 mapped square meters of deep ocean floor

Caracterización de grandes estructuras sismogénicas y tsunamogénicas del Golfo de Cádiz con tecnologías de muy alta resolución : Cruise Report INSIGHT-Leg 1

Cruise Report INSIGHT-Leg 1 R/V Sarmiento de Gamboa (SDG-68) 29th April - 18th May 2018.-- 139 pages, figures, tables, 2 annexesLarge earthquakes, submarine landslides and the tsunami they might originate are geohazards of great societal concern because they may impact world economies and struck coastal populations. Examples of these events are the 2004 northern Sumatra and 2011 Tohoku earthquakes and respective tsunamis. However, earthquakes of magnitude Mw > 8.0 in areas of relatively slow tectonic deformation and with long recurrence intervals, such as the external part of the Gulf of Cadiz, might also have a significant impact. The most relevant is the 1755 Lisbon earthquake, related submarine landslides and destructive tsunami. The occurrence of faults and landslides able to trigger a catastrophic tsunami reveals that the Gulf of Cadiz is one of the highest geohazard areas in Europe. Migration of sub-seafloor fluids has also been widely documented in the Gulf of Cadiz and such fluids are strongly related to the earthquake cycle and to the occurrence of submarine landslides. Understanding of these active processes can only be developed by using ultra-high-resolution tools able to map with unprecedented detail faults, submarine landslides and fluid escape structures. State-of-the-art techniques are used during INSIGHT-Leg 1, such as microbathymetry obtained from an autonomous underwater vehicle (AUV), sub-bottom profiles, HR multi-channel seismic data (MCS), and groundtruthing using sediment coresWe gratefully acknowledge financial support from Ministerio Economia y Competividad through national project INSIGHT “ImagiNg large SeismogenIc and tsunamiGenic structures of the Gulf of Cadiz with ultra-High resolution Technologies (INSIGHT-Leg1)” (CGL2011-30005-C02-02, PIs: Roger Urgeles and Eulàlia Gràcia) and Ocean Facilities Exchange Group (OFEG) for allowing us to use the AUVs “Abyss” from GEOMAR (Germany

Structural control, evolution, and accumulation rates of massive sulfides in the TAG hydrothermal field

The Trans‐Atlantic Geotraverse (TAG) hydrothermal field on the Mid‐Atlantic Ridge is one of the best‐studied hydrothermal systems to date. However, high‐resolution bathymetric data obtained in 2016 by an autonomous underwater vehicle (AUV) reveal new information about the distribution of active and inactive hydrothermal deposits, and their relation to structural features. The discovery of previously undocumented inactive vent sites contributes to a better understanding of the accumulation rates and the resource potential of seafloor massive sulfide deposits at slow‐spreading ridges. The interpretation of ship‐based and high‐resolution AUV‐based data sets allowed for the determination of the main tectonic stress regimes that have a first‐order control on the location and distribution of past and present hydrothermal activity. The data reveal the importance of cross‐cutting lineament populations and temporal variations in the prevalent stress regime. A dozen sulfide mounds contribute to a substantial accumulation of hydrothermal material (~29 Mt). The accumulation rate of ~1,500 t/yr is comparable to those of other modern seafloor vent fields. However, our observations suggest that the TAG segment is different from many other slow‐spreading ridge segments in its tectonic complexity, which confines sulfide formation into a relatively small area and is responsible for the longevity of the hydrothermal system and substantial mineral accumulation. The inactive and weakly active mounds contain almost 10 times the amount of material as the active high‐temperature mound, providing an important indication of the global resource potential for inactive seafloor massive sulfide deposits

AUV Abyss workflow: autonomous deep sea exploration for ocean research

Autonomous underwater vehicles (AUVs) equipped with multibeam echosounders (MBES) are essential for collecting high-resolution bathymetric data in the deep sea. Navigation of AUVs and accuracy of acquired MBES data is challenging, especially in deep water or rough terrain. Here, we present the AUV Abyss operational workflow that uses mission planning together with a long baseline (LBL) positioning network, and systematic post-processing of the MBES data using feature matching. The workflow enables autonomous exploration even in difficult terrain, makes ultrashort baseline navigation during the AUV survey obsolete and with this, increases the efficiency of ship time. It provides an efficient workflow for multi-survey mapping campaigns to produce high-resolution, large-coverage seafloor maps. Automated documentation of post-processing steps enhances the archiving of produced results, facilitates knowledge transfer, adaptation to other systems and management of large datasets. Comprehensive documentation allows developing routines that provide a first step towards automatization of AUV operations and MBES data processing

Potential contribution of surface-dwelling Sargassum algae to deep-sea ecosystems in the southern North Atlantic

Deep-sea ecosystems, limited by their inability to use primary production as a source of carbon, rely on other sources to maintain life. Sedimentation of organic carbon into the deep sea has been previously studied, however, the high biomass of sedimented Sargassum algae discovered during the VEMA Transit expedition in 2014/2015 to the southern North Atlantic, and its potential as a regular carbon input, has been an underestimated phenomenon. To determine the potential for this carbon flux, a literature survey of previous studies that estimated the abundance of surface water Sargassum was conducted. We compared these estimates with quantitative analyses of sedimented Sargassum appearing on photos taken with an autonomous underwater vehicle (AUV) directly above the abyssal sediment during the expedition. Organismal communities associated to Sargassum fluitans from surface waters were investigated and Sargassum samples collected from surface waters and the deep sea were biochemically analyzed (fatty acids, stable isotopes, C:N ratios) to determine degradation potential and the trophic significance within deep-sea communities. The estimated Sargassum biomass (fresh weight) in the deep sea (0.07 − 3.75 g/m2) was several times higher than that estimated from surface waters in the North Atlantic (0.024 – 0.84 g/m2). Biochemical analysis showed degradation of Sargassum occurring during sedimentation or in the deep sea, however, fatty acid and stable isotope analysis did not indicate direct trophic interactions between the algae and benthic organisms. Thus, it is assumed that components of the deep-sea microbial food web form an important link between the macroalgae and larger benthic organisms. Evaluation of the epifauna showed a diverse nano- micro-, meio, and macrofauna on surface Sargassum and maybe transported across the Atlantic, but we had no evidence for a vertical exchange of fauna components. The large-scale sedimentation of Sargassum forms an important trophic link between surface and benthic production and has to be further considered in the future as a regular carbon input to the deep-sea floor in the North Atlantic

Detailed Mapping and Sampling of the Reykjanes Ridge, Cruise No. MSM75, 29 June 2018 - 8 August 2018, Reykjavik - Reykjavik, REYKJANES

Hotspot-influenced spreading axes are characterized by a shallow axis, thickened crust, and possibly by higher-than-normal eruption frequency, all signs of an excess of magma and heat being supplied to such ridges by the hotspot. Despite this, these ridges are also characterized by an apparently lower-than-average incidence of high-temperature hydrothermal venting, raising questions about their thermal budget. The type example for hotspot-ridge interaction is the Reykjanes Ridge south of Iceland, which shows abnormally shallow bathymetry between the Reykjanes Peninsula at ca. 63°N and the Charlie Gibbs Fracture Zone at 53°N.The seafloor surrounding the present spreading axis is also characterized by V-shaped bathymetric ridges, thoughtto be produced by regions of excess melting migrating along the axis through time. Cruise MSM75aimed to produce geological maps of four key areas along the ridge -one with thickened crust where a V-shaped ridge intersects the present-day axis, one with thickened crust but no on-axis V-shaped ridge anomaly, a third with more normal crustal thickness and an axial valley and a fourth at the only known, but up to present unsampled, Reykjanes hydrothermal site Steinaholl. This geological mapping is to be usedto investigate questions of variations in eruption size or frequency away from Iceland, the interplay between magmatism and tectonism, the axial volcanology of V-shaped ridges and how thick crust is cooled in the apparent paucity of high-temperature vent fields