Viser treff 1136-1155 av 5067

    • Drivers of an unexpected unimodal vertical pattern in size distribution of intertidal blue mussels (Mytilus spp.) 

      Sellæg, Victoria Eggen (Master thesis; Mastergradsoppgave, 2023-11-14)
      Blue mussels (Mytilus spp.) are important ecosystem bioengineers and provide numerous of ecosystem services. They are found worldwide, but face a global population decline for unclear reasons in many regions. A pilot study in the subarctic rocky intertidal shore in Northern Norway revealed an unexpected unimodal pattern in the body size of blue mussels along a vertical transect from low to high ...
    • Drivers of Atmosphere-Ocean CO2 Flux in Northern Norwegian Fjords 

      Aalto, Nerea Johanna; Campbell, Karley; Eilertsen, Hans Christian; Bernstein, Hans Christopher (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-07)
      High-latitude fjords and continental shelves are shown to be sinks for atmospheric CO2, yet large spatial-temporal variability and poor regional coverage of sea-air CO2 flux data, especially from fjord systems, makes it difficult to scale our knowledge on how they contribute to atmospheric carbon regulation. The magnitude and seasonal variability of atmosphere-sea CO2 flux was investigated in ...
    • Drivers of behavioural transition in foraging adult female southern elephant seals (Mirounga leonina) tracked from Bouvetøya 

      Hannén, Rebecca (Master thesis; Mastergradsoppgave, 2022-10-18)
      Southern elephant seals are abundant top trophic predators with a circumpolar distribution in the Southern Ocean. They spend up to 80% of their life at sea on long-ranging migrations to remote foraging grounds. During breeding and moulting they haulout on subantarctic islands. During these migrations they dive continuously to great depth, encountering various environmental conditions. They ...
    • Drivers of diet patterns in a globally distributed freshwater fish species 

      Sánchez-Hernández, Javier; Finstad, Anders Gravbrøt; Arnekleiv, Jo Vegar; Kjærstad, Gaute; Amundsen, Per-Arne (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-24)
      We analysed data of a globally distributed model organism (brown trout) in an attempt to understand relationships among biogeography, prey communities and climate on diet composition at regional spatial scales (Scandinavia), and thereafter explored whether diet patterns remained the same at global scales. At regional scales, we uncovered comprehensive patterns in diet composition among neighbouring ...
    • Drivers of mercury accumulation over the ontogeny of perch (Perca fluviatilis) in the subarctic Pasvik watercourse 

      Fredriksen, Julie (Master thesis; Mastergradsoppgave, 2023-11-15)
      Understanding drivers of mercury (Hg) accumulation in freshwater food webs is vital due to its ability to accumulate in organisms and magnify in food webs to potent levels, potentially impacting wildlife and human health. This is of particular concern in regions where fish serve as an important food source. This study explores drivers of Hg accumulation in European perch (Perca fluviatilis) across ...
    • Driving Business Models Toward Sustainability in Arctic Nature Tourism 

      Sahebalzamani, Samira (Journal article; Tidsskriftartikkel; Peer reviewed, 2020)
      <i>Context</i>: research into sustainability as a highly debated concept has become widespread and given rise to a diverse and interesting arena in the management literature in which the relevance of business models is extensively acknowledged. <p> <p><i>Objective</i>: by integrating sustainability into the business model concept, this study attempts to determine how business models are ...
    • Driving through dense fog: a study of the effects and control of sustainable public procurement of electric cars 

      Langseth, Marius; Moe, Helene Tronstad (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-04-21)
      Governments are large buyers of vehicles, thus contributing to pollution. To promote sustainability, policies have been shaped to replace government-owned fossil fuel cars with electric cars. Public procurement is seen as a strategic tool for the government to transition. This study identifies a research gap due to a lack of studies on how stakeholders at different levels identify and calculate the ...
    • Drones and marine mammals in Svalbard 

      Palomino Gonzalez, Albert (Master thesis; Mastergradsoppgave, 2019-07-15)
      The impact of Remote Piloted Aircraft Systems (RPAS, or drones) on marine mammals remains poorly documented despite their increasing use by hobbyists and scientists. In the High-Arctic Archipelago of Svalbard, where marine mammals are facing increasing pressure from the coupled effects of climate modification and an expanding tourism industry, the use of RPAS remains largely unregulated to date. In ...
    • Drones and marine mammals in Svalbard, Norway 

      Palomino-González, Albert; Kovacs, Kit M.; Lydersen, Christian; Ims, Rolf Anker; Lowther, Andrew D. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-03-14)
      The impact of remotely piloted aircraft systems (RPAS) on marine mammals remains poorly documented despite their increasing use. In the high-Arctic Archipelago of Svalbard, where marine mammals face increasing pressure from climate change and expanding tourism, the use of RPAS remains largely unregulated. In this study we assessed the impacts of RPAS across a range of species to provide ...
    • Drones as a tool to monitor human impacts and vegetation changes in parks and protected areas 

      Ancin-Murguzur, Francisco Javier; Munoz, Lorena; Monz, Christopher; Hausner, Vera H. (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-04)
      Increased visitation to protected areas could have adverse impacts on the conservation values in the protected areas, and therefore effective visitor monitoring methods are needed to meet the complex management challenges that arise. Collecting data on human impacts is highly time consuming, thus requiring more effective tools that allow for high-quality and long-term measurements. In this study, ...
    • A dual process of shopping well-being across shopping contexts: The role of shopping values and impulse buying 

      Nghia, Ho Trong; Olsen, Svein Ottar; Trang, Nguyen Thi Mai (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-07-01)
      <p><i>Purpose:</i> Adopting the duality approach, this study aims to examine cognitive and affective associations between shopping values, impulse buying tendencies and consumer shopping well-being. In addition, the study also aims to test the moderating role of self-control and compare the proposed relationships across the offline and online shopping contexts. <p><i>Design/methodology/approach:</i> ...
    • Dual Targeting and Retrograde Translocation: Regulators of Plant Nuclear Gene Expression Can Be Sequestered by Plastids 

      Krause, Kirsten; Oetke, Svenja; Krupinska, Karin (Journal article; Tidsskriftartikkel; Peer reviewed, 2012)
      Changes in the developmental or metabolic state of plastids can trigger profound changes in the transcript profiles of nuclear genes. Many nuclear transcription factors were shown to be controlled by signals generated in the organelles. In addition to the many different compounds for which an involvement in retrograde signaling is discussed, accumulating evidence suggests a role for proteins in ...
    • The dually targeted transcription factor TF1 and its role in the expression of plastid- and nuclear-encoded photosynthesis genes 

      Olsen, Stian (Master thesis; Mastergradsoppgave, 2012-09-05)
      In plant cells, the distribution of genes on three spatially separated subgenomes calls for the necessity of maintaining a coordinated regulation of gene expression between these DNA-containing compartments. Especially, the translocation of nuclear-encoded gene products to plastids and mitochondria, which is crucial for the development and metabolic operation of these semi-autonomous organelles, ...
    • A Dynamic Occupancy Model for Interacting Species with Two Spatial Scales 

      Kleiven, Eivind Flittie; Barraquand, Frédéric; Gimenez, Olivier; Henden, John-André; Ims, Rolf Anker; Soininen, Eeva M; Yoccoz, Nigel (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-04-10)
      Occupancy models have been extended to account for either multiple spatial scales or species interactions in a dynamic setting. However, as interacting species (e.g., predators and prey) often operate at different spatial scales, including nested spatial structure might be especially relevant to models of interacting species. Here we bridge these two model frameworks by developing a multi-scale, ...
    • Dynamical Controls of the Eastward Transport of Overwintering Calanus finmarchicus From the Lofoten Basin to the Continental Slope 

      Dong, Huizi; Zhou, Meng; Smith, Walker O.; Li, Baosheng; Hu, Ziyuan; Basedow, Sünnje Linnéa; Gaardsted, Frank; Zhang, Zhaoru; Zhong, Yisen (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-09-06)
      Diapausing populations of Calanus finmarchicus at depth in the Lofoten Basin (LB) return to the continental shelf and slope off the Lofoten-Vesterålen Islands during the phytoplankton spring bloom to feed and spawn, forming surface swarms with a great abundance. To study how overwintering populations of C. finmarchicus move with the deep currents and return to the shelf, Lagrangian transport ...
    • Dynamics of bacterial community exposed to hydrocarbons and oleophilic fertilizer in high-Arctic intertidal beach 

      RØberg, stian; Østerhus, Jan ivar; Landfald, Bjarne (Journal article; Tidsskriftartikkel; Peer reviewed, 2011)
      Exposure of pristine microbial environments to hydrocarbon contamination stimulates growth of the initially small fraction of indigenous hydrocarbon-degrading bacteria. Custom-made oleophilic fertilizers have been demonstrated to promote oil bioremediation by boosting this proliferation. In the present study, the temporal dynamics of the bacterial community structure and the individual influences ...
    • The Dynamics of Pasture–Herbivores–Carnivores with Sigmoidal Density Dependent Harvesting 

      Bergland, Harald; Burlakov, Evgenii; Wyller, John Andreas (Journal article; Tidsskriftartikkel, 2023-09-19)
      We investigate biomass–herbivore–carnivore (top predator) interactions in terms of a tritrophic dynamical systems model. The harvesting rates of the herbivores and the top predators are described by means of a sigmoidal function of the herbivores density and the top predator density, respectively. The main focus in this study is on the dynamics as a function of the natural mortality and the maximal ...
    • Dynamikken i nedbrytningen av ATP i post mortem torskemuskel (Gadus morhua L.) og K-verdi som ferskhetsindikator 

      Lillevoll, Ragnar (Master thesis; Mastergradsoppgave, 2007-06-20)
      En forsøksgruppe av oppdrettet atlantisk torsk (Gadus morhua L.) ble i forkant av slakting utsatt for stressende aktivitet ved hjelp av O2-sjokk, mens en kontrollgruppe ble avlivet direkte med med slag mot hodet. Fra begge grupper ble foretatt prøver gjennom en fullstendig fersklagringsperiode, fra tidspunkt 0 (umiddelbart post mortem) og fram til 10 døgn. Særlig vekt ble lagt på den tidligste ...
    • Dypvannsrunddorg – Potensial for effektivt nytt redskap for den norske kystflåten 

      Nordheim, Torgeir (Master thesis; Mastergradsoppgave, 2015-02-15)
      I denne oppgaven vil jeg presentere utviklingsprosessen av og mulighetene for et nytt redskap for kyst- og fjordflåten, dypvannsrunddorg. Dypvannsrunddorgen som redskap er basert på den tradisjonelle runddorgen. Forskjellen er at med en dypvannsrunddorg kan en styre dybden fritt og dermed ha bedre tilgang til fisk som står dypt. Systemet muliggjør også at en kan benytte større bruk sammenlignet med ...
    • Dyrking av makroalger. En ny vekstnæring? 

      Kjørsvik, Audun Grøntoft (Master thesis; Mastergradsoppgave, 2017-05-15)
      Målet med denne studien er å skaffe et overblikk over hvordan statusen er for den norske næringen innenfor dyrking av makroalger. Makroalger som også kalles for tang og tare er den nyeste satsingen innenfor norsk akvakultur. Dette er akvatiske plantelignende organismer som deles inn i tre hovedgrupper: Grønne, røde og brune makroalger. Historiske sett er makroalger en ressurs som er blitt utnyttet ...