Viser treff 3521-3540 av 5440

    • High-resolution optical nanoscopy of placental cells 

      Ahluwalia, Balpreet Singh (Journal article; Tidsskriftartikkel; Peer reviewed, 2017)
      <i>Introduction</i>: The invention of fluorescence based super-resolution optical microscopy, commonly referred to as optical nanoscopy, has provided a glimpse of its future impacts on life science and medical care. Optical nanoscopy enables study of sub-cellular nanoscale biological systems in living cells, which in past was limited to electron microscopy (in fixed cells). Optical nanoscopy provide ...
    • Stepwise Deoxygenation of Nitrite as a Route to Two Families of Ruthenium Corroles: Group 8 Periodic Trends and Relativistic Effects 

      Alemayehu, Abraham; Vazquez Lima, Hugo; Gagnon, Kevin J.; Ghosh, Abhik (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-19)
      Given the many applications of ruthenium porphyrins, the rarity of ruthenium corroles and the underdeveloped state of their chemistry are clearly indicative of an area ripe for significant breakthroughs. The tendency of ruthenium corroles to form unreactive metal–metal-bonded dimers has been recognized as a key impediment in this area. Herein, by exposing free-base meso-tris(p-X-phenyl)corroles, ...
    • Exploring the role of L209 residue in the active site of NDM-1 a metallo-β-lactamase 

      Marcoccia, Francesca; Leiros, Hanna-Kirsti S.; Aschi, Massimiliano; Amicosante, Gianfranco; Perilli, Mariagrazia (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-01-02)
      Background:<br> New Delhi Metallo-β-Lactamase (NDM-1) is one of the most recent additions to the β-lactamases family. Since its discovery in 2009, NDM-1 producing Enterobacteriaceae have disseminated globally. With few effective antibiotics against NDM-1 producers, there is an urgent need to design new drug inhibitors through the help of structural and mechanistic information available from ...
    • Flexible Devices for Arctic Ecosystems Observations 

      Michalik, Lukasz Sergiusz; Anshus, Otto; Bjørndalen, John Markus (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-26)
      <p>Devices for observing the environment range from basic sensor systems, like step-counters, through wild-life cameras, with limited processing capabilities, to more capable devices with significant processing, memory and storage resources. Individual usage domains can benefit from a range of functionalities in these devices including flexibility in prototyping, on- device analytics, network roaming, ...
    • Scaling of global temperatures explained by linear energy balance models 

      Rypdal, Kristoffer; Fredriksen, Hege-Beate (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-12)
      <i>Introduction</i>: Scale invariance of natural variability of global surface temperatures is often interpreted as a signature of nonlinear dynamics. However, the observed scaling can be adequately explained by linear energy balance involving subsystems with different response times.
    • Surface Meltwater Impounded by Seasonal Englacial Storage in West Greenland 

      Kendrick, A.K.; Schroeder, D.M.; Chu, W.; Young, T.J.; Christoffersen, P.; Todd, J.; Doyle, S.H.; Box, J.E.; Hubbard, A.; Hubbard, B.; Brennan, P.V.; Nicholls, K. W.; Lok, L.B. (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-24)
      The delivery of surface meltwater through englacial drainage systems to the bed of the Greenland Ice Sheet modulates ice flow through basal lubrication. Recent studies in Southeast Greenland have identified a perennial firn aquifer; however, there are few observations quantifying the input or residence time of water within the englacial system and it remains unknown whether water can be stored within ...
    • Impact of natural (waves and currents) and anthropogenic (trawl) resuspension on the export of particulate matter to the open ocean: Application to the Gulf of Lion (NW Mediterranean) 

      Ferré, Bénédicte; Durrieu de Madron, X.; Estournel, C.; Ulses, G.; Le Corre, G. (Journal article; Tidsskriftartikkel; Peer reviewed, 2008-02-17)
      <p>Modern sediment deposits on continental margins form a vast reservoir of particulate matter that is regularly affected by resuspension processes. Resuspension by bottom trawling on shelves with strong fishing activity can modify the scale of natural disturbance by waves and currents. Recent field data show that the impact of bottom trawls on fine sediment resuspension per unit surface is comparable ...
    • Temperature observations from northernmost Greenland, 2006-2010 

      Schomacker, Anders; Larsen, Nicolaj K.; Bjørk, Anders A.; Kjær, Kurt H. (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-03-31)
      Air-, surface-, and subsurface temperatures were recorded by automatic weather stations in Bliss Bugt and Moore Gletscher, Johannes V. Jensen Land, North coast of Greenland from 2006-2010. The mean annual surface temperature is -12.1 ℃ in Bliss Bugt and -13.8 ℃ at Moore Gletscher. In 20 cm depth below the surface at Moore Gletscher, the mean annual temperature is -13.2 ℃ (2007-2008). High-amplitude ...
    • Contour current driven continental slope-situated sandwaves with effects from secondary current processes on the Barents Sea margin offshore Norway 

      King, Edward L.; Bøe, Reidulv; Bellec, Valérie K.; Rise, Leif Christian; Skardhamar, Jofrid; Ferré, Bénédicte; Dolan, Margaret F.J. (Journal article; Tidsskriftartikkel; Peer reviewed, 2014-04-15)
      Seabed data acquired from the southern Barents Sea continental margin offshore Norway reveal detailed morphology of large sandwave fields. Multibeam echosounder bathymetry and backscatter, shallow seismic, sediment samples and seabed video data collected by the MAREANO program have been used to describe and interpret the morphology, distribution and transport of the sandwaves. The bedforms lie on a ...
    • The Hotelling-Lawley trace statistic for change detection in polarimetric SAR data under the complex Wishart distribution 

      Akbari, Vahid; Anfinsen, Stian Normann; Doulgeris, Anthony Paul; Eltoft, Torbjørn (Journal article; Tidsskriftartikkel; Peer reviewed, 2014-01-27)
      In this paper we propose a new test statistic for unsupervised changedetectioninpolarimetricsyntheticapertureradar(PolSAR) data. We work with multilook complex (MLC) covariance matrix data, whose underlying model is assumed to be the scaled complex Wishart distribution. We use the complex kind Hotelling-Lawley (HL) trace statistic for measuring the similarity of two covariance matrices. The sampling ...
    • A change detector for polarimetric SAR data based on the relaxed Wishart distribution 

      Akbari, Vahid; Anfinsen, Stian Normann; Doulgeris, Anthony Paul; Eltoft, Torbjørn (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-12)
      In this paper, we present an unsupervised change detection method for polarimetric synthetic aperture radar (PolSAR) images based on the relaxed Wishart distribution. Most polarimetric change detectors assume the Gaussian-based complex Wishart model for multilook covariance matrices, which is only satisfied for homogeneous areas with fully developed speckle and no texture. Liu et al. recently proposed ...
    • Methane seepage at Vestnesa Ridge (NW Svalbard) since the Last Glacial Maximum 

      Schneider, Andrea; Panieri, Giuliana; Lepland, Aivo; Consolaro, Chiara; Crémière, Antoine; Forwick, Matthias; Johnson, J.E.; Plaza-Faverola, Andreia; Sauer, Simone; Knies, Jochen (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-06-21)
      <p>Multiple proxies in the geological record offshore NW Svalbard track shallow subseafloor diagenesis and seafloor methane seepage during the Last Glacial Maximum (LGM) extent and the disintegration of the Svalbard Barents Sea Ice Sheet (SBIS). Vestnesa Ridge, located at 79°N and in 1200 m water depth, is one of the northernmost known active methane seep sites and is characterised by a subseafloor ...
    • Comparative conformational analyses and molecular dynamics studies of glycylglycine methyl ester and glycylglycine N -methylamide 

      Thakkar, Balmukund S.; Engh, Richard Alan (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-01-24)
      Compared to their amide analogs, peptidic esters have a lower propensity for intramolecular hydrogen bonding, and thus most likely quite different stable geometries. On the other hand, their similarity and facile conversion to peptides has led to their broad use in synthetic and biological applications. This dichotomy creates a need to understand their conformational properties. Here, we study the ...
    • Distribution of living benthic foraminifera in the northern Chukchi Sea 

      Racine, Calypso; Bonnin, Jérôme; Nam, Seung-Il; Giraudeau, Jacques; Biguenet, Maude; Dessandier, Pierre-Antoine; Kim, Jung‑Hyun (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-27)
      Living (Rose Bengal stained) benthic foraminifera were studied in the topmost sediments of five multi- and box cores collected on the continental shelf, upper and lower slopes, of the Chukchi Sea to provide background information on modern benthic foraminiferal distribution, useful for future studies. Sediment cores were collected during August–September 2015, when the area is seasonally ice-free. ...
    • Density Functional Studies on Secondary Amides: Role of Steric Factors in Cis/Trans Isomerization 

      Thakkar, Balmukund; Svendsen, John Sigurd Mjøen; Engh, Richard Alan (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-25)
      Cis/trans isomerization of amide bonds is a key step in a wide range of biological and synthetic processes. Occurring through C-N amide bond rotation, it also coincides with the activation of amides in enzymatic hydrolysis. In recently described QM studies of cis/trans isomerization in secondary amides using density functional methods, we highlighted that a peptidic prototype, such as glycylglycine ...
    • Nordic Seas polynyas and their role in preconditioning marine productivity during the Last Glacial Maximum 

      Knies, Jochen; Koseoglu, Denizcan; Rise, Leif; Baeten, Nicole; Bellec, Valerie K; Bøe, Reidulv; Klug, Martin; Panieri, Giuliana; Jernas, Patrycja Ewa; Belt, Simon T. (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-27)
      Arctic and Antarctic polynyas are crucial sites for deep-water formation, which helps sustain global ocean circulation. During glacial times, the occurrence of polynyas proximal to expansive ice sheets in both hemispheres has been proposed to explain limited ocean ventilation and a habitat requirement for marine and higher-trophic terrestrial fauna. Nonetheless, their existence remains equivocal, ...
    • Spill som læringsverktøy. Algoritmisk tenking i klasserommet igjennom videospill 

      Kramvik, Jonas Ophaug (Master thesis; Mastergradsoppgave, 2018-08-13)
      I dette mastergradsprosjektet har jeg sett nærmere på hvordan bruk av TV-spill i klasserommet kan lære elever Algoritmisk tenking. Ettersom det nettopp ble vedtatt nye kjerneelementer i matematikk for ny læreplan i 2020 i henhold til fagfornyelsen anser jeg arbeidet som relevant og viktig for å sikre variert undervisning i skolen. Hensikten med undersøkelsen har vært å vise at algoritmisk ...
    • Multi-color imaging of sub-mitochondrial structures in living cells using structured illumination microscopy 

      Opstad, Ida Sundvor; Wolfson, Deanna; Øie, Cristina Ionica; Ahluwalia, Balpreet Singh (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-05-18)
      The dimensions of mitochondria are close to the diffraction limit of conventional light microscopy techniques, making the complex internal structures of mitochondria unresolvable. In recent years, new fluorescence-based optical imaging techniques have emerged, which allow for optical imaging below the conventional limit, enabling super-resolution (SR). Possibly the most promising SR and diffraction-limited ...
    • Shallow carbon storage in ancient buried thermokarst in the South Kara Sea 

      Portnov, Aleksei D; Mienert, Jürgen; Winsborrow, Monica; Andreassen, Karin; Vadakkepuliyambatta, Sunil; Semenov, Peter; Gataullin, Valery (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-25)
      Geophysical data from the South Kara Sea reveal U-shaped erosional structures buried beneath the 50–250 m deep seafloor of the continental shelf across an area of ~32 000 km<sup>2</sup>. These structures are interpreted as thermokarst, formed in ancient yedoma terrains during Quaternary interglacial periods. Based on comparison to modern yedoma terrains, we suggest that these thermokarst features ...
    • High-resolution 3D seismic exhibits new insights into the middle-late Pleistocene stratigraphic evolution and sedimentary processes of the Bear Island trough mouth fan 

      Waage, Malin; Bünz, Stefan; Bøe, Reidulv; Mienert, Jurgen (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-05-21)
      Arctic Ocean trough mouth fans (TMFs) represent a valuable archive of glacial-interglacial sedimentary processes that are especially important when reconstructing pre-Weichselian glaciations that may lack distinct imprints on the shelves. In 2011, we acquired the first high-resolution 3D seismic cube (~3 m vertical and 6 m horizontal resolution) on the continental slope of the SW Barents Sea by use ...