Viser treff 2441-2460 av 5369

    • Facile Supramolecular Engineering of Porphyrin cis Tautomers: The Case of β-Octabromo-meso-tetraarylporphyrins 

      Thomas, Kolle E.; Slebodnick, Carla; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-04-02)
      A porphyrin cis tautomer, where the two central NH protons are on adjacent pyrrole rings, has long been invoked as an intermediate in porphyrin tautomerism. Only recently, however, has such a species been isolated and structurally characterized. Thus, single-crystal X-ray structure determinations of two highly saddled free-base porphyrins, β-heptakis(trifluoromethyl)-meso-tetrakis(p-fluorophenyl)porphyrin, ...
    • Nature of the copper-nitrosyl intermediates of copper nitrite reductases during catalysis 

      Hough, Michael A.; Conradie, Jeanet; Strange, Richard W.; Antonyuk, Svetlana V.; Eady, Robert R.; Ghosh, Abhik; Hasnain, S. Samar (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-20)
      The design and synthesis of copper complexes that can reduce nitrite to NO has attracted considerable interest. They have been guided by the structural information on the catalytic Cu centre of the widespread enzymes Cu nitrite reductases but the chemically novel side-on binding of NO observed in all crystallographic studies of these enzymes has been questioned in terms of its functional relevance. ...
    • X-ray absorption spectroscopy of archetypal chromium porphyrin and corrole derivatives 

      Cao, Rui; Thomas, Kolle E.; Ghosh, Abhik; Sarangi, Ritimukta (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05-29)
      A combination of Cr K-edge XAS and DFT calculations have been performed on archetypal chromium porphyrinoid complexes Cr<sup>IV</sup>[TMP]O (<b>2</b>) and Cr<sup>V</sup>[TPC]O (<b>3</b>), and the results have been compared to the reference compound Cr<sup>III</sup>[TPP]Cl (<b>1</b>), where TPP<sup>2−</sup>, TMP<sup>2−</sup>, and TPC<sup>3−</sup> are the anions of <i>meso</i>-tetraphenylporphyrin, ...
    • Properties and dynamics of mesoscale eddies in Fram Strait from a comparison between two high-resolution ocean-sea ice models 

      Wekerle, Claudia; Hattermann, Tore; Wang, Qiang; Crews, Laura; von Appen, Wilken-Jon; Danilov, Sergey (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-23)
      Fram Strait, the deepest gateway to the Arctic Ocean, is strongly influenced by eddy dynamics. Here we analyse the output from two eddy-resolving models (ROMS – Regional Ocean Modeling System; FESOM – Finite-Element Sea-ice Ocean Model) with around 1 km mesh resolution in Fram Strait, with a focus on their representation of eddy properties and dynamics. A comparison with mooring observations shows ...
    • GeneNet VR: Large Biological Networks in Virtual Reality Using Inexpensive Hardware 

      Martínez Fernández, Álvaro (Master thesis; Mastergradsoppgave, 2020-11-15)
      Biological data is often visualized using networks. However, these networks face problems such as information overload, high interconnectivity, and high dimensionality. Existing approaches try to solve these problems by reducing the interactivity in favor of presenting more information or by using expensive hardware. This thesis aims to solve them using Virtual Reality (VR) and the Oculus Quest, an ...
    • Improving the text compression ratio for ASCII text Using a combination of dictionary coding, ASCII compression, and Huffman coding 

      Haldar-Iversen, Sondre (Mastergradsoppgave; Master thesis, 2020-11-15)
      Data compression is a field that has been extensively researched. Many compression algorithms in use today have been around for several decades, like Huffman Coding and dictionary coding. These are general-purpose compression algorithms and can be used on anything from text data to images and video. There are, however, much fewer lossless algorithms that are customized for compressing certain types ...
    • Object detection at the edge 

      Mathiassen, Truls (Mastergradsoppgave; Master thesis, 2020-11-10)
      While monitoring rodents in the Arctic Tundra to evaluate if climate changes affect the ecosystem. The camera-traps of the coat project generates image data in large scale each year. To manually examine the data in regards to label- ing is a tedious and time-consuming job, and a more efficient and automated tool for the task is required. In this thesis we presents the architecture, design and ...
    • The high catalytic rate of the cold-active Vibrio alkaline phosphatase requires a hydrogen bonding network involving a large interface loop 

      Hjörleifsson, Jens Guðmundur; Helland, Ronny; Magnusdottir, Manuela; Ásgeirsson, Bjarni (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-16)
      The role of surface loops in mediating communication through residue networks is still a relatively poorly understood part in the study of cold adaptation of enzymes, especially in terms of their quaternary interactions. Alkaline phosphatase (AP) from the psychrophilic marine bacterium <i>Vibrio splendidus</i> (VAP) is characterized by an analogous large surface loop in each monomer, referred to as ...
    • Features extraction of wind ramp events from a virtual wind park 

      Mishra, Sambeet; Oren, Esin; Bordin, Chiara; Wen, Fushuan; Palu, Ivo (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-26)
      In the European renewable energy portfolio, wind has a sizeable share in the total energy production. The Nordic and Baltic energy systems in particular are benefiting from wind energy to reach the greenhouse gas emissions reduction objectives set by the EU. The wind energy production varies with time, and this intermittent characteristic imposes a challenge for full utilization of renewable energy ...
    • Integrated analysis of multi-sensor datasets and oil drift simulations - a free floating oil experiment in the open ocean 

      Brekke, Camilla; Espeseth, Martine; Dagestad, Knut-Frode; Röhrs, Johannes; Hole, Lars Robert; Reigber, Andreas (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-01-20)
      A free‐floating oil spill experiment (two oil types) in the open ocean is described, and the results from slick characterization through integrated analysis of drift simulations with remote sensing and in situ data are discussed. We compare oil drift simulations (OpenOil), applying various configurations of wind, wave, and current information, with the observed slick positions and shape. We describe ...
    • Snow avalanche segmentation in SAR images with Fully Convolutional Neural Networks 

      Bianchi, Filippo Maria; Grahn, Jakob; Eckerstorfer, Markus; Malnes, Eirik; Vickers, Hannah (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-10)
      Knowledge about frequency and location of snow avalanche activity is essential for forecasting and mapping of snow avalanche hazard. Traditional field monitoring of avalanche activity has limitations, especially when surveying large and remote areas. In recent years, avalanche detection in Sentinel-1 radar satellite imagery has been developed to improve monitoring. However, the current state-of-the-art ...
    • 1H, 13C, 15N resonance assignment of the apo form of the small, chitin-active lytic polysaccharide monooxygenase JdLPMO10A from Jonesia denitrificans 

      Christensen, Idd Andrea; Eijsink, Vincent; Aachmann, Finn Lillelund; Courtade, Gaston (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-19)
      The lytic polysaccharide monooxygenase <i>Jd</i>LPMO10A is the N-terminal domain of the multimodular protein Jd1381. The isolated <i>Jd</i>LPMO10A domain is one of the smallest chitin-active lytic polysaccharide monooxygenases known to date with a size of only 15.5 kDa. <i>Jd</i>LPMO10A is a copper-dependent oxidative enzyme that depolymerizes chitin by hydroxylating the C1 carbon in the glycosidic ...
    • Artefact removal in ground truth deficient fluctuations-based nanoscopy images using deep learning 

      Jadhav, Suyog; Acuña Maldonado, Sebastian Andres; Opstad, Ida Sundvor; Ahluwalia, Balpreet Singh; Agarwal, Krishna; Prasad, Dilip K. (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-12-08)
      Image denoising or artefact removal using deep learning is possible in the availability of supervised training dataset acquired in real experiments or synthesized using known noise models. Neither of the conditions can be fulfilled for nanoscopy (super-resolution optical microscopy) images that are generated from microscopy videos through statistical analysis techniques. Due to several physical ...
    • nsroot: Minimalist process isolation tool implemented with Linux namespaces 

      Raknes, Inge Alexander; Fjukstad, Bjørn; Bongo, Lars Ailo Aslaksen (Journal article; Tidsskriftartikkel, 2017-11-26)
      Data analyses in the life sciences are moving from tools run on a personal computer to services run on large computing platforms. This creates a need to package tools and dependencies for easy installation, configuration and deployment on distributed platforms. In addition, for secure execution there is a need for process isolation on a shared platform. Existing virtual machine and container ...
    • Selecting technological alternatives for regulatory compliance towards emissions reduction from shipping: An integrated fuzzy multi-criteria decision-making approach under vague environment 

      Bui, Khanh Q.; Ölçer, Aykut I.; Kitada, Momoko; Ballini, Fabio (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-01)
      Due to the increasing pressure from stricter environmental regulations to reduce emissions in shipping, the maritime industry has been striving for finding more effective measures. Existing measures are often not enough to comply with new regulations. Among various alternative measures, it is not easy for decision-makers (shipowners and operators) to choose the most suitable alternative measure as ...
    • Machine learning derived input-function in a dynamic 18F-FDG PET study of mice 

      Kuttner, Samuel; Wickstrøm, Kristoffer Knutsen; Kalda, Gustav; Dorraji, Seyed Esmaeil; Martin-Armas, Montserrat; Oteiza, Ana; Jenssen, Robert; Fenton, Kristin Andreassen; Sundset, Rune; Axelsson, Jan (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-13)
      Tracer kinetic modelling, based on dynamic <sup>18</sup>F-fluorodeoxyglucose (FDG) positron emission tomography (PET) is used to quantify glucose metabolism in humans and animals. Knowledge of the arterial input-function (AIF) is required for such measurements. Our aim was to explore two non-invasive machine learning-based models, for AIF prediction in a small-animal dynamic FDG PET study. 7 tissue ...
    • Photonic-chip based free space beam shaping and steering for advanced optical microscopy application 

      Lahrberg, Marcel; Dullo, Firehun Tsige; Ahluwalia, Balpreet Singh (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-02-12)
      Photonic-chip-based light illumination has recently found applications in optical microscopy and nanoscopy methodologies. The photonic chip removes the dependency on imaging objective lenses to generate the required illumination patterns for different microscopy methods. Until now, all the reported chip-based optical microscopy methods exploit the evanescent field present on top of a waveguide surface ...
    • HyperKvasir, a comprehensive multi-class image and video dataset for gastrointestinal endoscopy 

      Borgli, Hanna; Thambawita, Vajira; Smedsrud, Pia H; Hicks, Steven; Jha, Debesh; Eskeland, Sigrun Losada; Randel, Kristin Ranheim; Pogorelov, Konstantin; Lux, Mathias; Dang Nguyen, Duc Tien; Johansen, Dag; Griwodz, Carsten; Stensland, Håkon Kvale; Garcia-Ceja, Enrique; Schmidt, Peter T; Hammer, Hugo Lewi; Riegler, Michael; Halvorsen, Pål; de Lange, Thomas (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-28)
      Artificial intelligence is currently a hot topic in medicine. However, medical data is often sparse and hard to obtain due to legal restrictions and lack of medical personnel for the cumbersome and tedious process to manually label training data. These constraints make it difficult to develop systems for automatic analysis, like detecting disease or other lesions. In this respect, this article ...
    • Drone-Mounted UWB Snow Radar: Technical Improvements and Field Results 

      Jenssen, Rolf-Ole Rydeng; Jacobsen, Svein Ketil (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-04)
      Drone borne radar systems have seen considerable advances over recent years, and the application of drone-mounted continuous wave (CW) radars for remote sensing of snow properties has great potential. Regardless, major challenges remain in antenna design for which both low weight and small size combined with high gain and bandwidth are important design parameters. Additional limiting factors for CW ...
    • Synthesis and molecular structure of perhalogenated rhenium-oxo corroles 

      Alemayehu, Abraham B.; Einrem, Rune F.; McCormick‑McPherson, Laura J.; Settineri, Nicholas S.; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-12)
      As part of our efforts to develop rhenium-oxo corroles as photosensitizers for oxygen sensing and photodynamic therapy, we investigated the potential <i>β</i>-perhalogenation of five ReO <i>meso</i>-tris(<i>para</i>-X-phenyl)corroles, Re[T<i>p</i>XPC](O) (X = CF<sub>3</sub>, H, F, CH<sub>3</sub>, and OCH<sub>3</sub>), with elemental chlorine and bromine. With Cl<sub>2</sub>, <i>β</i>-octachlorinated ...