Now showing items 1321-1340 of 1636

    • Using Ordinary Digital Cameras in Place of Near-Infrared Sensors to Derive Vegetation Indices for Phenology Studies of High Arctic Vegetation 

      Anderson, Helen; Nilsen, Lennart; Tømmervik, Hans; Karlsen, Stein Rune; Nagai, Shin; Cooper, Elisabeth J. (Journal article; Tidsskriftartikkel; Peer reviewed, 2016)
      To remotely monitor vegetation at temporal and spatial resolutions unobtainable with satellite-based systems, near remote sensing systems must be employed. To this extent we used Normalized Difference Vegetation Index NDVI sensors and normal digital cameras to monitor the greenness of six different but common and widespread High Arctic plant species/groups (graminoid/Salix polaris; Cassiope tetragona; ...
    • Seasonal vertical strategies in a high-Arctic coastal zooplankton community 

      Bandara, Kanchana; Varpe, Øystein; Søreide, Janne; Wallenschus, Jago; Berge, Jørgen; Eiane, Ketil (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-08-18)
      We studied the larger (>1000 µm) size fraction of zooplankton in an Arctic coastal water community in Billefjorden, Svalbard (78°40’ N), Norway, in order to describe seasonal vertical distributions of the dominant taxa in relation to environmental variability. Calanus spp. numerically dominated the herbivores; Aglantha digitale, Mertensia ovum, Beroë cucumis, and Parasagitta elegans were the ...
    • Development and evaluation of internet-based PPGIS 

      Hausner, Vera Helene; Lægreid, Eiliv Jenssen; Pietrzyk-Kaszyńska, Agata; Olszańska, Agnieszka; Grodzińska-Jurczak, Malgorzata; Brown, Greg (Research report; Forskningsrapport, 2014-10-15)
    • Effects of chronic dietary petroleum exposure on reproductive development in polar cod (Boreogadus saida) 

      Bender, Morgan Lizabeth; Frantzen, Marianne; Vieweg, Ireen; Falk-Petersen, Inger-Britt; Johnsen, Helge Kreutzer; Rudolfsen, Geir; Tollefsen, Knut Erik; Dubourg, Paul; Nahrgang, Jasmine (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-10-04)
      Increasing human activities in the Arctic raise the risk of petroleum pollution, thus posing an elevated risk for Arctic organisms to be chronically exposed to petroleum compounds. The endocrine disrupting properties of some of these compounds (i.e. polycyclic aromatic hydrocarbons [PAHs]) present in crude oil may have negative effects on the long and energy intensive reproductive development of ...
    • An empirical evaluation of spatial value transfer methods for identifying cultural ecosystem services 

      Brown, Greg; Pullar, David; Hausner, Vera Helene (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-04-09)
      A significant barrier to the assessment of ecosystem services is a lack of primary data, especially for cultural ecosystem services. Spatial value transfer, also known as benefits transfer, is a method to identify the probable locations of ecosystem services based on empirical spatial associations found in other geographic locations. To date, there has been no systematic evaluation of spatial value ...
    • Rumen and Cecum Microbiomes in Reindeer (Rangifer tarandus tarandus) Are Changed in Response to a Lichen Diet and May Affect Enteric Methane Emissions 

      Salgado, Alejandro Flores; Hagen, Live Heldal; Ishaq, Suzanne L.; Zamanzadeh, Mirzaman; Wright, Andre-Denis G.; Pope, Phillip; Sundset, Monica Alterskjær (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-05-09)
      Reindeer (Rangifer tarandus tarandus) are large Holarctic herbivores whose heterogeneous diet has led to the development of a unique gastrointestinal microbiota, essential for the digestion of arctic flora, which may include a large proportion of lichens during winter. Lichens are rich in plant secondary metabolites, which may affect members of the gut microbial consortium, such as the methane-producing ...
    • A first insight into the fecal microbiota of the high Arctic muskoxen (Ovibos moschatus) 

      Salgado, Alejandro Flores; Bockwoldt, Mathias; Hagen, Live Heldal; Pope, Phillip; Sundset, Monica Alterskjær (Journal article; Tidsskriftartikkel, 2016-07-11)
      The faecal microbiota of muskoxen (n=3) pasturing on Ryøya (69° 33′ N 18° 43′ E), Norway, in late September was characterized using high-throughput sequencing of partial 16S rRNA gene regions. A total of 16 209 high-quality sequence reads from bacterial domains and 19 462 from archaea were generated. Preliminary taxonomic classifications of 806 bacterial operational taxonomic units (OTUs) resulted ...
    • Changing Arctic snow cover: A review of recent developments and assessment of future needs for observations, modelling, and impacts 

      Bokhorst, Stef; Pedersen, Stine Højlund; Brucker, Ludovic; Anisimov, Oleg; Bjerke, Jarle W.; Brown, Ross D.; Ehrich, Dorothee (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-03-17)
      Snow is a critically important and rapidly changing feature of the Arctic. However, snow-cover and snowpack conditions change through time pose challenges for measuring and prediction of snow. Plausible scenarios of how Arctic snow cover will respond to changing Arctic climate are important for impact assessments and adaptation strategies. Although much progress has been made in understanding ...
    • Herding conditions related to infectious keratoconjunctivitis in semi-domesticated reindeer: a questionnaire-based survey among reindeer herders 

      Tryland, Morten; Stubsjøen, Solveig Marie; Ågren, Erik Olof; Johansen, Bernt; Kielland, Camilla (Journal article; Peer reviewed; Tidsskriftartikkel, 2016-04-12)
      Background: Infectious keratoconjunctivitis (IKC) in Eurasian semi-domesticated reindeer (Rangifer tarandus tarandus) is a multifactorial disease, associated to infectious agents such as Cervid herpesvirus 2 (CvHV2) and various species of bacteria, but environmental factors may also be necessary to initiate the disease. Little effort seems to have been invested in addressing the herder`s experience ...
    • Marine Mammal Brucella Reference Strains Are Attenuated in a BALB/c Mouse Model 

      Nymo, Ingebjørg Helena; Arias, Maykel; Pardo, Julian; Álvarez, María Pilar; Alcaraz, Ana; Godfroid, Jacques; Jiménez de Bagüés, María Pilar (Journal article; Peer reviewed; Tidsskriftartikkel, 2016-03-09)
      Brucellosis is a zoonosis of worldwide distribution with numerous animal host species. Since the novel isolation of Brucella spp. from marine mammals in 1994 the bacteria have been isolated from various marine mammal hosts. The marine mammal reference strains Brucella pinnipedialis 12890 (harbour seal, Phoca vitulina) and Brucella ceti 12891 (harbour porpoise, Phocoena phocoena) were included in ...
    • Under the snow: a new camera trap opens the white box of subnivean ecology 

      Soininen, Eeva M; Jensvoll, Ingrid; Killengreen, Siw Turid; Ims, Rolf Anker (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-05-14)
      Snow covers the ground over large parts of the world for a substantial portion of the year. Yet very few methods are available to quantify biotic variables below the snow, with most studies of subnivean ecological processes relying on comparisons of data before and after the snow cover season. We developed a camera trap prototype to quantify subnivean small mammal activity. The trap consists of a ...
    • Breeding persistence of Slavonian Grebe (Podiceps auritus) at long-term monitoring sites: predictors of a steep decline at the northern European range limit 

      Stien, Jenny; Strann, Karl Birger; Jepsen, Jane Uhd; Frivoll, Vigdis Irene; Ims, Rolf Anker (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-06-10)
      The Slavonian Grebe (Podiceps auritus) has its European northern range limit in northern Norway, and is a species of national conservation concern due to its small population size and unknown population trend. Long-term monitoring at the range limit suggests breeding site use is in decline. We used annual occupancy data from 104 breeding lakes monitored since 1991 in northern Norway to investigate ...
    • Reindeer and tundra in a changing world: threats and opportunities (språk: engelsk og samisk) 

      Oksanen, Lauri Kalervo (Conference object; Konferansebidrag, 2015-10-15)
    • Mapping species distributions: a comparison of skilled naturalist and lay citizen science recording 

      van der Wal, René; Anderson, Helen; Robinson, Annie; Sharma, Nirwan; Mellish, Chris; Roberts, Stuart; Darvill, Ben; Siddharthan, Advaith (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-10-27)
      To assess the ability of traditional biological recording schemes and lay citizen science approaches to gather data on species distributions and changes therein, we examined bumblebee records from the UK’s national repository (National Biodiversity Network) and from BeeWatch. The two recording approaches revealed similar relative abundances of bumblebee species but different geographical distributions. ...
    • Anthocyanin Profile in Berries of Wild and Cultivated Vaccinium spp. along Altitudinal Gradients in the Alps 

      Zoratti, Laura; Jaakola, Laura; Häggman, Hely; Giongo, Lara (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-09-16)
      Vaccinium spp. berries provide some of the best natural sources of anthocyanins. In the wild bilberry (Vaccinium myrtillus L.), a clear increasing trend in anthocyanin biosynthesis has been reported toward northern latitudes of Europe, but studies related to altitude have given contradictory results. The present study focused on the anthocyanin composition in wild bilberries and highbush blueberry ...
    • Adaptive flexibility in the feeding behaviour of brown trout: optimal prey size 

      Sanchez-Hernandez, Javier; Cobo, Fernando (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-02-18)
      Background Brown trout, Salmo trutta Linnaeus, 1758, is a species of significant conservation and socio-economic importance. A consequence of this importance is the enormous amount of literature that has been published on the species in the last few decades. In general terms, brown trout has been considered as a size-selective predator, even though it is able to feed on a wide range of prey sizes. ...
    • Genetic diversity and population structure of an important wild berry crop 

      Zoratti, Laura; Palmieri, Luisa; Jaakola, Laura; Häggman, Hely (Journal article; Tidsskriftartikkel; Peer reviewed, 2015)
      The success of plant breeding in the coming years will be associated with access to new sources of variation, which will include landraces and wild relatives of crop species. In order to access the reservoir of favourable alleles within wild germplasm, knowledge about the genetic diversity and the population structure of wild species is needed. Bilberry (Vaccinium myrtillus) is one of the most ...
    • Light and temperature effects on bioactivity in diatoms 

      Ingebrigtsen, Richard Andre; Hansen, Espen; Andersen, Jeanette hammer; Eilertsen, Hans Christian (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-06-05)
      Isolates of five pelagic North Atlantic marine diatoms (Bacillariophyceae): Attheya longicornis, Chaetoceros socialis, Chaetoceros furcellatus, Skeletonema marinoi and Porosira glacialis were cultivated in large photobioreactors at two light and two temperature regimes to test if this affected bioactivity. We screened for bioactivity in assays representing five different therapeutic areas: ...
    • Superb Winter fur insulation in small Siberian musk deer (Moschus moschiferus) 

      Blix, Arnoldus S; Kvadsheim, Petter Helgevold; Kholodova, Marina V.; Sokolov, Vladimir E.; Messelt, Edward B.; Tyler, N. J. C. (Journal article; Tidsskriftartikkel, 2015)
    • Muscle growth of triploid Atlantic cod juveniles (Gadus morhua) 

      Vargas, Cecilia Campos; Peruzzi, Stefano; Palihawadana, Anjana; Ottesen, Oddvar; Hagen, Ørjan (Journal article; Tidsskriftartikkel; Peer reviewed, 2015)
      This study has investigated the muscle growth of diploid and triploid Atlantic cod (Gadus morhua) juveniles raised in replicate tanks over a period of 29 weeks and analysed at three sampling points (February, June and September). Data for weight, length, condition factor (K), muscle fibre growth and myogenic progenitor cells (MPCs) number were collected and results were analysed in relation ...