Opin vísindi

Browsing Greinar- HÍ by Title

Browsing Greinar- HÍ by Title

Sort by: Order: Results:

  • Benediktsson, Bardi; Þórhallsson, Albert Þ.; Bjornsson, Ragnar (Royal Society of Chemistry (RSC), 2018)
    A new 1.2 Å crystal structure of vanadium nitrogenase, isolated under turnover conditions, recently revealed a light atom ligand (OH or NH) replacing the bridging S2B sulfide of the FeV cofactor. QM/MM calculations on the new structure now reveal the ...
  • Benediktsson, Bardi; Bjornsson, Ragnar (American Chemical Society (ACS), 2017-10-20)
    Nitrogenase is one of the most fascinating enzymes in nature, being responsible for all biological nitrogen reduction. Despite decades of research, it is among the enzymes in bioinorganic chemistry whose mechanism is the most poorly understood. The ...
  • Hempenius, Mirjam; Luijken, Kim; Boer, Anthonius; Klungel, Olaf; Groenwold, Rolf; Gardarsdottir, Helga (Wiley, 2020-05-11)
    Purpose: Exposure definitions vary across pharmacoepidemiological studies. Therefore, transparent reporting of exposure definitions is important for interpretation of published study results. We aimed to assess the quality of reporting of exposure to ...
  • Turmezei, Thomas; Treece, Graham; Gee, A. H.; Sigurðsson, Sigurður; Jonsson, Helgi; Aspelund, Thor; Gudnason, Vilmundur; Poole, Kenneth E.S. (Springer Science and Business Media LLC, 2020-03-05)
    Osteoarthritis is an increasingly important health problem for which the main treatment remains joint replacement. Therapy developments have been hampered by a lack of biomarkers that can reliably predict disease, while 2D radiographs interpreted by ...
  • Turchin, Peter; Currie, Thomas E.; Whitehouse, Harvey; François, Pieter; Feeney, Kevin; Mullins, Daniel; Hoyer, Daniel; Collins, Christina; Grohmann, Stephanie; Savage, Patrick; Mendel-Gleason, Gavin; Turner, Edward; Dupeyron, Agathe; Cioni, Enrico; Reddish, Jenny; Levine, Jill; Jordan, Greine; Brandl, Eva; Williams, Alice; Cesaretti, Rudolf; Krueger, Marta; Ceccarelli, Alessandro; Figliulo-Rosswurm, Joe; Tuan, Po-Ju; Peregrine, Peter; Marciniak, Arkadiusz; Preiser-Kapeller, Johannes; Kradin, Nikolay; Korotayev, Andrey; Palmisano, Alessio; Baker, David; Bidmead, Julye; Bol, Peter; Christian, David; Cook, Connie; Covey, Alan; Feinman, Gary; Júlíusson, Árni Daníel; Kristinsson, Axel; Miksic, John; Mostern, Ruth; Petrie, Cameron; Rudiak-Gould, Peter; ter Haar, Barend; Wallace, Vesna; Mair, Victor; Xie, Liye; Baines, John; Bridges, Elizabeth; Manning, Joseph; Lockhart, Bruce; Bogaard, Amy; Spencer, Charles (Proceedings of the National Academy of Sciences, 2017-12-21)
    Do human societies from around the world exhibit similarities in the way that they are structured, and show commonalities in the ways that they have evolved? These are long-standing questions that have proven difficult to answer. To test between competing ...
  • Ásgeirsson, Vilhjálmur; Bauer, Christoph A.; Grimme, Stefan (Royal Society of Chemistry (RSC), 2017)
    We introduce a fully stand-alone version of the Quantum Chemistry Electron Ionization Mass Spectra (QCEIMS) program [S. Grimme, Angew. Chem. Int. Ed., 2013, 52, 6306] allowing efficient simulations for molecules composed of elements with atomic numbers ...
  • Benediktsson, Bardi; Bjornsson, Ragnar (American Chemical Society (ACS), 2020-08-05)
    The nitrogenase enzymes are responsible for all biological nitrogen reduction. How this is accomplished at the atomic level, however, has still not been established. The molybdenum-dependent nitrogenase has been extensively studied and is the most ...
  • Kozin, Valerii; Iorsh, Ivan; Kibis, Oleg; Shelykh, Ivan (American Physical Society (APS), 2018-04-26)
    We developed the theory of electronic properties of semiconductor quantum rings with the Rashba spin-orbit interaction irradiated by an off-resonant high-frequency electromagnetic field (dressing field). Within the Floquet theory of periodically driven ...
  • Banerjee, Souvik; Engelsöy, Julius; Larana-Aragon, Jorge; Sundborg, Bo; Thorlacius, Larus; Wintergerst, Nico (Springer Science and Business Media LLC, 2019-08-01)
    A macroscopic version of Einstein-Podolsky-Rosen entanglement is obtained by quenching a quadratic coupling between two O(N) vector models. A quench of the mixed vacuum produces an excited entangled state, reminiscent of purified thermal equilibrium, ...
  • Jónasson, Jón Torfi; Óskarsdóttir, Gunnhildur (2015)
    Abstract This paper investigates the importance for pupils’ learning of being generally visibly active participant in a classroom discussion. A class of six year-old pupils was taught about the human skeletal system and other organs. To determine ...
  • Erlendsdóttir, Erla (Stofnun Vigdísar Finnbogadóttur í erlendum tungumálum, 2016)
    Orð af norrænum uppruna, einkum orð sem lúta að skipasmíði og siglingum, voru á sínum tíma tekin upp í normandísku þaðan sem þau bárust inn í frönsku sem miðlaði þeim aftur á móti til annara rómanskra tungumála, til að mynda spænsku. Má hér nefna ...
  • Abdullah, Nzar (Elsevier BV, 2019-12)
    The transport properties of a wire-dot system coupled to a quantized single photon with linear polarization in a 3D-cavity is theoretically studied using a quantum master equation. The system is also coupled to a photon reservoir, environment. We ...
  • Björnsson, Helgi; Pálsson, Finnur (Cambridge University Press (CUP), 2020-03-11)
    Since the mid-1970s radio-echo soundings have been conducted on Iceland's temperate glaciers. Since then, low-frequency radar technology has furthered the study of most of the island's ice caps. Their masses and volumes have been quantified and detailed ...
  • Einarsdóttir, Bergþóra F.; Björnsdóttir, Margrét Sigríður (Menntavísindastofnun, Menntavísindasvið, Háskóli Íslands, 2020-03-19)
    Í þessari grein er fjallað um samstarfsrannsókn sem fram fór í einum leikskóla á höfuðborgarsvæðinu. Þátttakendur í leikskólanum voru fimm ásamt meistaranema og kennara frá Menntavísindaviði Háskóla Íslands. Rannsóknin er hluti af samstarfsverkefni ...
  • Ásgeirsson, Árni; Kristjansson, Arni (Frontiers Media SA, 2014-04-10)
    Consistent financial reward of particular features influences the allocation of visual attention in many ways. More surprising are 1-trial reward priming effects on attention where reward schedules are random and reward on one trial influences attentional ...
  • Young, Susan; Emilsson, Brynjar; Sigurdsson, Jon Fridrik; Khondoker, Mizanur; Philipp-Wiegmann, Florence; Baldursson, Gísli; Ólafsdóttir, Halldóra; Gudjonsson, Gisli (Springer Nature, 2016-10-17)
    Studies assessing psychological treatment of attention deficit hyperactivity disorder (ADHD) in adults are increasingly reported. However, functional outcomes are often neglected in favour of symptom outcomes. We investigated functional outcomes in 95 ...
  • Pogge von Strandmann, Philip A. E.; Burton, Kevin W.; Snæbjörnsdóttir, Sandra Ósk; Sigfússon, Bergur; Aradóttir, Edda S.; Gunnarsson, Ingvi; Alfreðsson, Helgi A.; Mesfin, Kiflom G.; Oelkers, Eric H.; Gíslason, Sigurður Reynir (Springer Science and Business Media LLC, 2019-04-30)
    The engineered removal of atmospheric CO 2 is now considered a key component of mitigating climate warming below 1.5 °C. Mineral carbonation is a potential negative emissions technique that, in the case of Iceland’s CarbFix experiment, precipitates ...
  • Chetverikov, Andrey; Campana, Gianluca; Kristjansson, Arni (Association for Research in Vision and Ophthalmology (ARVO), 2017-02-28)
    We recently demonstrated that observers are capable of encoding not only summary statistics, such as mean and variance of stimulus ensembles, but also the shape of the ensembles. Here, for the first time, we show the learning dynamics of this process, ...
  • Smith, Dirk; Helgason, Hannes; sulem, patrick; Björnsdóttir, Unnur Steina; Lim, Ai Ching; Sveinbjornsson, Gardar; Hasegawa, Haruki; Brown, Michael; Ketchem, Randal R.; Gavala, Monica; Garrett, Logan; Jónasdóttir, Aðalbjörg; Jónasdóttir, Áslaug; Sigurðsson, Ásgeir; Magnússon, Ólafur T.; Eyjólfsson, Guðmundur I.; Ólafsson, Ísleifur; Önundarson, Páll Torfi; Sigurðardóttir, Ólöf; Gíslason, Davíð; Gislason, Thorarinn; Ludviksson, Bjorn; Lúðvíksdóttir, Dóra; Boezen, H. Marike; Heinzmann, Andrea; Krueger, Marcus; Porsbjerg, Celeste; Ahluwalia, Tarunveer S.; Waage, Johannes; Backer, Vibeke; Deichmann, Klaus A.; Koppelman, Gerard H.; Bønnelykke, Klaus; Bisgaard, Hans; Másson, Gísli; Thorsteinsdottir, Unnur; Gudbjartsson, Daniel; Johnston, James A.; Jonsdottir, Ingileif; Stefansson, Kari (Public Library of Science (PLoS), 2017-03-08)
    IL-33 is a tissue-derived cytokine that induces and amplifies eosinophilic inflammation and has emerged as a promising new drug target for asthma and allergic disease. Common variants at IL33 and IL1RL1, encoding the IL-33 receptor ST2, associate with ...
  • Björnsson, Þorsteinn; Þórólfsdóttir, Rósa B.; Sveinbjornsson, Gardar; sulem, patrick; Norðdahl, Guðmundur L.; Helgadóttir, Anna; Grétarsdóttir, Sólveig; Magnusdóttir, Auður; Danielsen, Ragnar; Sigurðsson, Emil Lárus; Adalsteinsdottir, Berglind; Gunnarsson, Sverrir I; Jonsdottir, Ingileif; Arnar, Davíð O.; Helgason, Hróðmar; Gudbjartsson, Tomas; Gudbjartsson, Daniel; Thorsteinsdottir, Unnur; Holm, Hilma; Stefansson, Kari (Oxford University Press (OUP), 2018-03-24)
    Aims Coarctation of the aorta (CoA) accounts for 4-8% of congenital heart defects (CHDs) and confers substantial morbidity despite treatment. It is increasingly recognized as a highly heritable condition. The aim of the study was to search for sequence ...