Blar i tittel Fakultet for naturvitenskap og teknologi

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    • Two models of population genetics 

      Skancke, Jørgen (Master thesis; Mastergradsoppgave, 2008-06-02)
      The production of proteins in a cell is a regulated process. This means that the cell will only produce a type of protein when that type is needed. A fundamental step where this regulation occurs is at gene transcription. It is observed that transcription is regulated differently for different genes, and the question is therefore asked: why has evolution come up with different modes of transcriptional ...

    • Two SnRK2-Interacting Calcium Sensor Isoforms Negatively Regulate SnRK2 Activity by Different Mechanisms 

      Tarnowski, Krzysztof; Klimecka, Maria; Ciesielski, Arkadiusz; Goch, Grazyna; Kulik, Anna; Fedak, Halina; Poznanski, Jaroslaw; Lichocka, Malgorzata; Pierechod, Marcin Miroslaw; Engh, Richard Alan; Dadlez, Michal; Dobrowolska, Grazyna; Bucholc, Maria (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-11-07)
      SNF1-related protein kinases 2 (SnRK2s) are key signaling elements regulating abscisic acid-dependent plant development and responses to environmental stresses. Our previous data showed that the SnRK2-interacting Calcium Sensor (SCS) inhibits SnRK2 activity. Use of alternative transcription start sites located within the Arabidopsis (Arabidopsis thaliana) AtSCS gene results in two in-frame transcripts ...

    • Two-axis tracking solar irradiance measurements at Tromsø 

      Hansen, Jakob Holden (Master thesis; Mastergradsoppgave, 2020-06-29)
      The world is changing towards using more renewable, rather than fossil energy sources in order to reach the 1.5 degrees celsius goal of the Paris agreement (Merchant, 2018). This thesis’ main focus is to investigate the solar irradiance in Tromsø using 2-axis tracking measurements from May 2020. The reduction of global irradiance and direct irradiance is also compared against the values of the other ...

    • Two-billion-year-old evaporites capture Earth’s great oxidation 

      Blättler, C.L.; Claire, M.W.; Prave, A.R.; Kirsimäe, K.; Higgins, J.A.; Medvedev, P.V.; Romashkin, A.E; Rychanchik, D.V.; Zerkle, A.L.; Paiste, Kärt; Kreitsmann, T.; Millar, I.L.; Hayles, J.A.; Bao, H.; Turchyn, A.V.; Warke, M.R.; Lepland, Aivo (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-04-20)
      Major changes in atmospheric and ocean chemistry occurred in the Paleoproterozoic era (2.5 to 1.6 billion years ago). Increasing oxidation dramatically changed Earth’s surface, but few quantitative constraints exist on this important transition. This study describes the sedimentology, mineralogy, and geochemistry of a 2-billion-year-old, ~800-meter-thick evaporite succession from the Onega Basin in ...

    • A Two-Component Generalization of the Integrable rdDym Equation 

      Morozov, Oleg (Journal article; Tidsskriftartikkel; Peer reviewed, 2012)
      We find a two-component generalization of the integrable case of rdDym equation. The reductions of this system include the general rdDym equation, the Boyer-Finley equation, and the deformed Boyer-Finley equation. Also we find a Bäcklund transformation between our generalization and Bodganov's two-component generalization of the universal hierarchy equatio

    • Two-dimensional CNN-based distinction of human emotions from EEG channels selected by Multi-Objective evolutionary algorithm 

      Moctezuma, Luis Alfredo; Abe, Takashi; Molinas Cabrera, Maria Marta (Journal article; Tidsskriftartikkel; Peer reviewed, 2022)
      In this study we explore how different levels of emotional intensity (Arousal) and pleasantness (Valence) are reflected in Electroencephalographic (EEG) signals. We performed the experiments on EEG data of 32 subjects from the DEAP public dataset, where the subjects were stimulated using 60-second videos to elicitate different levels of Arousal/Valence and then self-reported the rating from 1-9 ...

    • Two-dimensional TIRF-SIM–traction force microscopy (2D TIRF-SIM-TFM) 

      Barbieri, Liliana; Colin-York, Huw; Korobchevskaya, Kseniya; Li, Di; Wolfson, Deanna; Karedla, Narain; Schneider, Falk; Ahluwalia, Balpreet Singh; Seternes, Tore; Dalmo, Roy Ambli; Dustin, Michael L.; Li, Dong; Fritzsche, Marco (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-04-12)
      Quantifying small, rapidly evolving forces generated by cells is a major challenge for the understanding of biomechanics and mechanobiology in health and disease. Traction force microscopy remains one of the most broadly applied force probing technologies but typically restricts itself to slow events over seconds and micron-scale displacements. Here, we improve >2-fold spatially and >10-fold temporally ...

    • Two-Photon Absorption Cross-Sections in Fluorescent Proteins Containing Non-canonical Chromophores Using Polarizable QM/MM 

      Rossano-Tapia, Maria; Olsen, Jógvan Magnus Haugaard; Brown, Alex (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-12)
      Multi-photon absorption properties, particularly two-photon absorption (2PA), of fluorescent proteins (FPs) have made them attractive tools in deep-tissue clinical imaging. Although the diversity of photophysical properties for FPs is wide, there are some caveats predominant among the existing FP variants that need to be overcome, such as low quantum yields and small 2PA cross-sections. From a ...

    • Two-photon absorption in host-guest complexes 

      Alam, Mehboob; Ruud, Kenneth (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-17)
      We present an extensive analysis of one- and two-photon absorption processes in some organic host-guest (H-G) complexes using linear and quadratic response theory within the framework of time-dependent density functional theory. For this purpose, we have considered all possible 20 host-guest complexes constructed from 4 host and 5 guest molecules. We have analysed how the one- and two-photon activity ...

    • Two-stage exhumation of subducted Saxothuringian continental crust records underplating in the subduction channel and collisional forced folding (Krkonoše-Jizera Mts., Bohemian Massif) 

      Jerabek, Petr; Konopasek, Jiri; Žáčková, Eliška (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-08)
      The Krkonoše-Jizera Massif in the northern part of the Variscan Bohemian Massif provides insight into the exhumation mechanisms for subducted continental crust. The studied region exposes a relatively large portion of a flat-lying subduction-related complex that extends approximately 50 km away from the paleosuture. wide extent of HP-LT metamorphism has been confirmed by new P-T estimates indicating ...

    • Type-I ion outflow from the high latitude ionosphere 

      Argese, Chiara (Master thesis; Mastergradsoppgave, 2013-11-15)
      The aim of this thesis is to study type-I ion outflows in the high latitude ionosphere. Type-I ion outflows are characterized by strong perpendicular electric fields, enhanced and anisotropic ion temperatures and low electron densities below 300 km, indicating small amounts of hard particle precipitation. We scanned data from the EISCAT Madrigal database over a period of 10 years (January 2000 - ...

    • Typical hydrodynamic models for aquaculture nets: A comparative study under pure current conditions 

      Cheng, Hui; Li, Lin; Aarsæther, Karl Gunnar; Ong, Muk Chen (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-17)
      The net is regarded as the most critical component in marine aquaculture facilities as it is the only barrier which protects the environment from fish escapes. Accurate predictions of the net cage deformation and drag force on the nets are needed, both for ensuring fish welfare and for dimensioning of the mooring system. Thus, an appropriate hydrodynamic model is essential. In practice, two types ...

    • U-Pb geochronology of crustal evolution and orogeny Contributions from Caledonide Spitsbergen and the Precambrian West Troms Basement Complex, North Norway 

      Myhre, Per Inge (Doctoral thesis; Doktorgradsavhandling, 2011-09-23)

    • U-Pb zircon provenance of metamorphosed clastic sediments in the Brusque Metamorphic Complex, Dom Feliciano Belt, southeastern Brazil 

      Eiesland, Ragnhild (Master thesis; Mastergradsoppgave, 2018-05-15)
      The Brusque Metamorphic Complex is situated in the northern part of the Dom Feliciano Belt in the state of Santa Catarina, southeastern Brazil. The complex is composed of Neoproterozoic sequences of volcanic and sedimentary rocks, which were folded and metamorphosed at greenschist to low-amphibolite facies conditions. U-Pb dating of detrital zircon grains in five samples of clastic metasedimentary ...

    • U-Th chronology and formation controls of methane-derived authigenic carbonates from the Hola trough seep area, northern Norway 

      Sauer, Simone; Knies, Jochen; Lepland, Aivo; Sahy, Diana; Martma, Tõnu; Noble, Stephen R.; Schönenbergerb, Jasmin; Klug, Martin; Schubert, Carsten J. (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-10-20)
      We investigated methane-derived authigenic carbonate (MDAC) crusts and nodules from a cold seep site on the northern Norwegian continental shelf in ca. 220 m water depth to determine the timing and mode of their formation. Gas bubbling observed during remotely operated vehicle (ROV)-assisted sampling of MDAC crusts revealed ongoing seep activity. Authigenic carbonates were present as crusts on the ...

    • UAV as an inspection tool for power lines in Troms: Assessment of UAVs as a viable alternative to already established methods for inspection of power lines. 

      Ubeda-Nordnes, Jonathan (Master thesis; Mastergradsoppgave, 2018-06-02)
      Power line inspection is one of the most important things in a modern society, and therefore it is important that it be kept in a functional state. Because of this, many methods are used to keep it that way. There are many factors to consider before using UAVs as a viable alternative to already established methods. Factors such as robustness against harsh weather, limits to its range and battery ...

    • UAV photogrammetry and structure from motion to assess calving dynamics at Store Glacier, a large outlet draining the Greenland ice sheet 

      Ryan, Johnny C.; Hubbard, Alun Lloyd; Box, Jason E.; Todd, Joe; Christoffersen, Poul; Carr, J. Rachel; Holt, Tom O.; Snooke, Neal A. (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-01-06)
      This study presents the application of a costeffective, unmanned aerial vehicle (UAV) to investigate calving dynamics at a major marine-terminating outlet glacier draining the western sector of the Greenland ice sheet. The UAV was flown over Store Glacier on three sorties during summer 2013 and acquired over 2000 overlapping, geotagged images of the calving front at an ∼ 40 cm ground sampling ...

    • UAV-BORNE UWB RADAR FOR SNOWPACK SURVEYS 

      Eckerstorfer, Markus; Jenssen, Rolf Ole Rydeng; Kjellstrup, Andre; Storvold, Rune; Malnes, Eirik; Jacobsen, Svein Ketil (Research report; Forskningsrapport, 2018)
      In this report we summarize the capabilities and technical characteristics of our UAV-borne UWB radar system, designed for conducting snow surveys. We developed an ultrawideband snow sounder that is capable of imaging snow stratigraphy with a 5 cm range resolution. The radar can be carried by an octocopter UAV in order to carry out airborne snowpack surveys. During a demonstration on Andøya, we ...

    • Ubiquitous digital health-related data: clarification of concepts 

      Johannessen, Erlend; Henriksen, André; Hartvigsen, Gunnar; Horsch, Alexander; Årsand, Eirik; Johansson, Jonas (Chapter; Bokkapittel, 2022-08-22)
      The increased development and use of ubiquitous digital services reinforce the trend where health-related data is generated everywhere. Data usage in different areas introduces different terms for the same or similar concepts. This adds to the confusion of what these terms represent. We aim to provide an overview of concepts and terms used in connection with digital twins and in a healthcare context.

    • Ultrasonic image denoising using machine learning in point contact excitation and detection method 

      Singh, Himanshu; Ahmed, Arif Sheikh; Melandsø, Frank; Habib, Anowarul (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-09-06)
      A point contact/Coulomb coupling technique is generally used for visualizing the ultrasonic waves in Lead Zirconate Titanate (PZT) ceramics. The point contact and delta pulse excitation produce a broadband frequency spectrum and wide directional wave vector. In ultrasonic, the signal is corrupted with several types of noises such as speckle, Gaussian, Poisson, and salt and pepper noise. Consequently, ...