Now showing items 861-880 of 1515

    • Metabarcoding as a quantitative tool for estimating biodiversity and relative biomass of marine zooplankton 

      Ershova, Elizaveta; Wangensteen, Owen S.; Descoteaux, Raphaelle; Barth-Jensen, Coralie Marie Christine; Præbel, Kim (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-31)
      Although metabarcoding is a well-established tool for describing diversity of pelagic communities, its quantitative value is still controversial, with poor correlations previously reported between organism abundance/biomass and sequence reads. In this study, we explored an enhanced quantitative approach by metabarcoding whole zooplankton communities using a highly degenerate primer set for the ...
    • Metabolic and molecular analysis of white mutant Vaccinium berries show down-regulation of MYBPA1-type R2R3 MYB regulatory factor 

      Primetta, Anja; Karppinen, Katja; Riihinen, Kaisu; Jaakola, Laura (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-07-14)
      Main conclusion MYBPA1-type R2R3 MYB transcription factor shows down-regulation in white mutant berries of Vaccinium uliginosum deficient in anthocyanins but not proanthocyanidins suggesting a role in the regulation of anthocyanin biosynthesis. <p>Berries of the genus Vaccinium are among the best natural sources of flavonoids. In this study, the expression of structural and regulatory flavonoid ...
    • Metabolic and trophic interactions modulate methane production in response to warming 

      Tveit, Alexander Tøsdal; Urich, Tim; Frenzel, Peter; Svenning, Mette Marianne (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-04-27)
      Arctic permafrost soils store large amounts of soil organic carbon (SOC) that could be released into the atmosphere as methane (CH4) in a future warmer climate. How warming affects the complex microbial network decomposing SOC is not understood. We studied CH4 production of Arctic peat soil microbiota in anoxic microcosms over a temperature gradient from 1 to 30 °C, combining metatranscriptomic, ...
    • Metagenomic Survey for Viruses in Western Arctic Caribou, Alaska, through Iterative Assembly of Taxonomic Units 

      Schürch, Anita; Schipper, Debby; Bijl, Maarten; Dau, Jim; Beckmen, Kimberly; Schapendonk, Claudia M.E.; Raj, Stalin; Osterhaus, Albert D.M. E.; Haagmans, Bart L.; Tryland, Morten; Smits, Saskia L (Journal article; Tidsskriftartikkel; Peer reviewed, 2014)
    • Metagenomics of the Svalbard Reindeer Rumen Microbiome Reveals Abundance of Polysaccharide Utilization Loci 

      Pope, Phillip B; Mackenzie, Alasdair; Gregor, Ivan; Smith, Wendy; Sundset, Monica Alterskjær; McHardy, Alice; Morrison, Mark; Eijsink, Vincent (Journal article; Tidsskriftartikkel; Peer reviewed, 2012)
      Lignocellulosic biomass remains a largely untapped source of renewable energy predominantly due to its recalcitrance and an incomplete understanding of how this is overcome in nature. We present here a compositional and comparative analysis of metagenomic data pertaining to a natural biomass-converting ecosystem adapted to austere arctic nutritional conditions, namely the rumen microbiome of Svalbard ...
    • Metatranscriptomic Analysis of Arctic Peat Soil Microbiota 

      Tveit, Alexander Tøsdal; Tim, Urich; Svenning, Mette Marianne (Journal article; Tidsskriftartikkel; Peer reviewed, 2014-07-11)
      Recent advances in meta-omics and particularly metatranscriptomic approaches have enabled detailed studies of the structure and function of microbial communities in many ecosystems. Molecular analyses of peat soils, ecosystems important to the global carbon balance, are still challenging due to the presence of coextracted substances that inhibit enzymes used in downstream applications. We sampled ...
    • Methyl jasmonate: An alternative for improving the quality and health properties of fresh fruits 

      Reyes-Diaz, Marjorie; Lobos, Tomas; Cardemil, Liliana; Nunes-Nesi, Adriano; Retamales, Jorge B..; Jaakola, Laura; Alberdi, Miren; Ribera-Fonseca, Alejandra (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-05-31)
      Methyl jasmonate (MeJA) is a plant growth regulator belonging to the jasmonate family. It plays an important role as a possible airborne signaling molecule mediating intra- and inter-plant communications and modulating plant defense responses, including antioxidant systems. Most assessments of this compound have dealt with post-harvest fruit applications, demonstrating induced plant resistance ...
    • Methylmercury biomagnification in an Arctic pelagic food web 

      Ruus, Anders; Øverjordet, Ida Beathe; Braaten, Hans Fredrik Veiteberg; Evenset, Anita; Christensen, Guttorm N.; Heimstad, Eldbjørg Sofie; Gabrielsen, Geir W.; Borgå, Katrine (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-08-14)
      Mercury (Hg) is a toxic element that enters the biosphere from natural and anthropogenic sources, and emitted gaseous Hg enters the Arctic from lower latitudes by long-range transport. In aquatic systems, anoxic conditions favor the bacterial transformation of inorganic Hg to methylmercury (MeHg), which has a greater potential for bioaccumulation than inorganic Hg and is the most toxic form of Hg. ...
    • Micro- and macro-habitat selection of Atlantic salmon, (Salmo salar), post-smolts in relation to marine environmental cues 

      Jensen, Jenny Lovisa Alexandra; Strøm, John Fredrik; Nikolopoulos, Anna; Primicerio, Raul; Skardhamar, Jofrid; Atencio, Benjamin J.; Strand, Jo Espen Tau; Bjørn, Pål Arne; Bøhn, Thomas (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-04-20)
      Atlantic salmon is an economically and culturally important species. The species encounters several natural and man-made threats during its migration between fresh water and the ocean, which in combination may explain its ongoing decline. With the aim to better understand whether post-smolt behaviour is influenced by physical oceanographic conditions, the migratory behaviour of 173 post-smolts in a ...
    • Microbial carbon use and associated changes in microbial community structure in high-Arctic tundra soils under elevated temperature 

      Frossard, Aline; De Maeyer, Lotte; Adamczyk, Magdalene; Svenning, Mette Marianne; Verleyen, Elie; Frey, Beat (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-08)
      In the high-Arctic, increased temperature results in permafrost thawing and increased primary production. This fresh plant-derived material is predicted to prime microbial consortia for degradation of the organic matter stored in tundra soils. However, the effects of warming and plant input on the microbial community structure is hardly known. We assessed the use of glycine, a readily available C ...
    • Microbial eukaryotes in an arctic under-ice spring bloom north of Svalbard 

      Meshram Rao, Archana; Vader, Anna; Kristiansen, Svein; Gabrielsen, Tove M. (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06-28)
      Microbial eukaryotes can play prominent roles in the Arctic marine ecosystem, but their diversity and variability is not well known in the ice-covered ecosystems. We determined the community composition of microbial eukaryotes in an Arctic under-ice spring bloom north of Svalbard using metabarcoding of DNA and RNA from the hypervariable V4 region of 18S nrDNA. At the two stations studied, the ...
    • Microbial processes in a high-latitude fjord (Kongsfjorden, Svalbard) : II. Ciliates and dinoflagellates 

      Seuthe, Lena; Iversen, Kriss Wenche Rokkan (Journal article; Tidsskriftartikkel; Peer reviewed, 2011)
      The composition and ecological role of ciliates and dinoflagellates were investigated at one station in Kongsfjorden, Svalbard, during six consecutive field campaigns between March and December 2006. Total ciliate and dinoflagellate abundance mirrored the seasonal progression of phytoplankton, peaking with 5.8 9 104 cells l-1 in April at an average chlorophyll a concentration of 10 lg l-1. ...
    • Microbial responses to herbivory-induced vegetation changes in a high-Arctic peatland 

      Bender, Kathrin Marina; Svenning, Mette Marianne; Hu, Yuntao; Richter, Andreas; Schückel, Julia; Jørgensen, Bodil; Liebner, Susanne; Tveit, Alexander Tøsdal (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-03-30)
      Herbivory by barnacle geese (<i>Branta leucopsis</i>) alters the vegetation cover and reduces ecosystem productivity in high-Arctic peatlands, limiting the carbon sink strength of these ecosystems. Here we investigate how herbivory-induced vegetation changes affect the activities of peat soil microbiota using metagenomics, metatranscriptomics and targeted metabolomics in a comparison of fenced ...
    • Mid-summer vertical behavior of a high-latitude oceanic zooplankton community 

      Bandara, Kanchana; Basedow, Sünnje Linnéa; Pedersen, Geir; Tverberg, Vigdis (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-18)
      Vertical behavior, such as diel vertical migration (DVM) and swarming are widespread among zooplankton. At higher latitudes, synchronized DVM is mostly absent during summer and predominantly herbivorous copepods tend to form large near-surface swarms. This behavior is risky because it can make them vulnerable to visual predators. Here, we used ca. 12 days of mid-summer (28 June to 10 July 2018) ...
    • Midnight Sun to Polar Night: A Model of Seasonal Light in the Barents Sea 

      Connan-McGinty, Stacey; Banas, Neil S.; Berge, Jørgen; Cottier, Finlo Robert; Grant, Stephen; Johnsen, Geir; Kopec, Tomasz Piotr; Porter, Marie; Mckee, David (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-09-20)
      Arctic marine ecosystems are strongly influenced by the extreme seasonality of light in the region. Accurate determination of light is essential for building a comprehensive understanding of the dynamics of animal and aquatic algae populations. Current approaches to underwater light field parameterisations rely upon shortwave radiation (300–3000 nm) estimates from satellites or surface radiometry ...
    • Migration and habitat use of the landlocked riverine Atlantic salmon Salmo salar småblank 

      Davidsen, Jan Grimsrud; Eikås, Linda; Hedger, Richard David; Thorstad, Eva Bonsak; Rønning, Lars; Sjursen, Aslak Darre; Berg, Ole Kristian; Bremset, Gunnbjørn; Karlsson, Sten; Sundt-Hansen, Line Elisabeth Breivik (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-04-18)
      “Småblank” is the only population of Atlantic salmon in Europe living its entire life in the river habitat without performing migrations to the sea or lakes. Home range size and habitat use were compared between an unregulated tributary and hydro-power regulated parts of the main river during 2014–2017. In total, 140 småblank were tagged with radio transmitters and tracked for 4–5 months. Tagged ...
    • Migratory behaviour and survival rates of wild northern Atlantic salmon (Salmo salar) post-smolts: effects of environmental factors 

      Thorstad, EB; Davidsen, Jan Grimsrud; Økland, F.; Rikardsen, Audun H.; Halttunen, Elina; Letcher, B.H,; Skardhamar, Jofrid; Næsje, Tor (Journal article; Tidsskriftartikkel; Peer reviewed, 2009-12-03)
      To study smolt behaviour and survival of a northern Atlantic salmon (Salmo salar) population during river descent, sea entry and fjord migration, 120 wild S. salar were tagged with acoustic tags and registered at four automatic listening station arrays in the mouth of the North Norwegian River Alta and throughout the Alta Fjord. An estimated 75% of the post-smolts survived from the river mouth, ...
    • Migratory behaviour and survival rates of wild northern Atlantic salmon Salmo salar post-smolts: effects of environmental factors 

      Thorstad, EB; Davidsen, Jan Grimsrud; Økland, F.; Rikardsen, Audun H.; Halttunen, Elina; Letcher, B.H,; Næsje, Tor; Skardhamar, Jofrid (Conference object; Konferansebidrag, 2009-09-14)
    • Miljørisikovurdering av genmodifisert maishybrid Bt11 x MIR604 x GA21 til mat, fôr, import og prosessering under EU-forordning 1829/2003/EF (EFSA/GMO/UK/2008/56). Uttalelse fra Faggruppe for genmodifiserte organismer i Vitenskapskomiteen for mattrygghet 

      Nerland, Audun Helge; Andreassen, Åshild Kristine; Brandtzæg, Per; Holck, Askild Lorentz; Junttila, Olavi; Konestabo, Heidi Sjursen; Meadow, Richard; Nielsen, Kaare Magne; Sorteberg, Hilde-Gunn Opsahl; Vikse, Rose (Research report; Forskningsrapport, 2013-03-19)
      I forbindelse med forberedelse til implementering av EU-forordning 1829/2003 i norsk rett, er Vitenskapskomiteen for mattrygghet (VKM) bedt av Direktoratet for naturforvalting (DN) om å utarbeide endelige miljørisikovurderinger av alle genmodifiserte organismer (GMOer) og avledete produkter som inneholder eller består av GMOer som er godkjent i EU under forordning 1829/2003 eller direktiv ...
    • Mineral prospectivity mapping: a potential technique for sustainable mineral exploration and mining activities – a case study using the copper deposits of the Tagmout basin, Morocco 

      Echogdali, Fatima Zahra; Boutaleb, Said; Abia, El Hassan; Ouchchen, Mohammed; Dadi, Bouchra; Id-Belqas, Mouna; Abioui, Mohamed; Pham, Luan Thanh; Abu-Alam, Tamer; Mickus, Kevin L. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-22)
      Mineral prospectivity mapping (MPM) based on the principle of geometric mean was applied to stream sediment geochemical, fault density, and aeromagnetic data from Tagmout basin, Morocco to determine new areas for optimizing copper exploration. The application of a fuzzy operator using stream sediment data, factor analysis, and fault density map, allowed weights to be assigned to these parameters so ...