Now showing items 1141-1160 of 2050

    • The radiation exposure of fish in the period of the Techa river peak contamination 

      Shishkina, Elena A.; Pryakhin, Evgeny A.; Sharagin, Pavel A.; Osipov, D.I.; Tryapitsina, Galina A.; Atamanyuk, Natalia I.; Egoreichenkov, E.A.; Trapeznikov, A.V.; Rudolfsen, G.; Teien, H.C.; Sneve, M.K. (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-10)
      Waterborne radioactive releases into the Techa River from the Mayak Production Association in Russia during 1949–1956 resulted in downstream contamination of the river ecosystem. The discharged liquid waste contained both short-lived isotopes (95Zr, 95Nb, 103,106Ru, 141,144Ce, 91Y, 89Sr and 140Ba with half-life from 3 days to 1.02 years) and the long-lived 90Sr and 137Cs (half-life - 28.79 y and ...
    • Sticky mucilages and exudates of plants – putative microenvironmental design elements with biotechnological value 

      Galloway, Andrew; Knox, Paul; Krause, Kirsten (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-24)
      Plants produce a wide array of secretions both above and below ground. Known as mucilages or exudates, they are secreted by seeds, roots, leaves and stems and fulfil a variety of functions including adhesion, protection, nutrient acquisition and infection. Mucilages are generally polysaccharide‐rich and often occur in the form of viscoelastic gels and in many cases have adhesive properties. In some ...
    • Assessing the effect of predator control on an endangered goose population subjected to predator-mediated food web dynamics 

      Marolla, Filippo; Aarvak, Tomas; Øien, Ingar Jostein; Mellard, Jarad Pope; Henden, John-André; Hamel, Sandra; Stien, Audun; Tveraa, Torkild; Yoccoz, Nigel Gilles; Ims, Rolf Anker (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-01-29)
      <ol> <li>Assessing the effectiveness of conservation actions to halt population declines is challenging when confounded by other factors. We assessed whether culling of red fox, a predator currently increasing in number in the sub‐Arctic, contributed to recent recovery of the critically endangered Fennoscandian population of Lesser White‐fronted Goose <i>Anser erythropus</i>, while controlling for ...
    • High resistance to climatic variability in a dominant tundra shrub species 

      Gonzalez, Victoria; Moriana Armendariz, Mikel; Hagen, Snorre; Lindgård, Bente; Reiersen, Rigmor; Bråthen, Kari Anne (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-05)
      Climate change is modifying temperature and precipitation regimes across all seasons in northern ecosystems. Summer temperatures are higher, growing seasons extend into spring and fall and snow cover conditions are more variable during winter. The resistance of dominant tundra species to these season-specific changes, with each season potentially having contrasting effects on their growth and survival, ...
    • Arctic greening and bird nest predation risk across tundra ecotones 

      Ims, Rolf Anker; Henden, John-André; Strømeng, Marita Anti; Thingnes, Anders Voss; Garmo, Mari; Jepsen, Jane Uhd (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-01)
      Alarming global-scale declines of bird numbers are occurring under the changing climate, and species belonging to alpine and Arctic tundra are particularly affected. Increased nest predation appears to be involved4, but the mechanisms linking predation to climate change remain to be shown. Here we test the prediction from food web theory that increased primary productivity (greening of tundra) in a ...
    • Spatial synchrony in sub-arctic geometrid moth outbreaks reflects dispersal in larval and adult life cycle stages 

      Vindstad, Ole Petter Laksforsmo; Jepsen, Jane Uhd; Yoccoz, Nigel Gilles; Bjørnstad, Ottar Nordal; Mesquita, Michel d. S.; Ims, Rolf Anker (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-08)
      <OL> <LI>Spatial synchrony in population dynamics can be caused by dispersal or spatially correlated variation in environmental factors like weather (Moran effect). Distinguishing between these mechanisms is challenging for natural populations, and the study of dispersal‐induced synchrony in particular has been dominated by theoretical modelling and laboratory experiments. <LI>The goal of the ...
    • Growth and metabolism of adult polar cod (Boreogadus saida) in response to dietary crude oil 

      Nahrgang, Jasmine; Bender, Morgan Lizabeth; Meier, Sonnich; Nechev, Jordan; Berge, Jørgen; Frantzen, marianne (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-05-06)
      The increasing human presence in the Arctic shelf seas, with the expansion of oil and gas industries and maritime shipping, poses a risk for Arctic marine organisms such as the key species polar cod (<i>Boreogadus saida</i>). The impact of dietary crude oil on growth and metabolism of polar cod was investigated in the early spring (March–April) when individuals are expected to be in a vulnerable ...
    • Comparative effects of two temperatures (0 & 3 °C) on Polar cod embryonic and larval development 

      Jones, Connie (Master thesis; Mastergradsoppgave, 2019-11-14)
      Polar cod (Boreogadus saida) are particularly vulnerable to climate change. Increasing our knowledge of polar cod development will help improve our understanding of the impact of climate change and the impacts this might have on the population. This study aimed at characterizing the development of Polar cod from fertilisation to 86 days post fertilisation (dpf) at two temperatures within their ...
    • Recreational fisheries target declining populations of brown trout (Salmo trutta L.) in Northern Norway as revealed by a genome wide array of SNP markers 

      Schmidt, Simon Nordblad (Master thesis; Mastergradsoppgave, 2019-11-15)
      Marine recreational and commercial exploitation of salmonids often target a mixed stock consisting of genetically distinct and independent populations with varying abundances, life histories, standing genetic variation, and conservation status. In this study we use SNP markers to investigate the genetic population structure of juvenile brown trout (Salmo trutta L.) from five distinct watercourses ...
    • Keeping the balance in NAD metabolism 

      Strømland, Øyvind; Niere, Marc; Nikiforov, Andrey; Van Linden, Magali R; Heiland, Ines; Ziegler, Mathias (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-01-09)
      Research over the last few decades has extended our understanding of nicotinamide adenine dinucleotide (NAD) from a vital redox carrier to an important signalling molecule that is involved in the regulation of a multitude of fundamental cellular processes. This includes DNA repair, cell cycle regulation, gene expression and calcium signalling, in which NAD is a substrate for several families of ...
    • Effect of incubation temperature on eggs and larvae of lumpfish (Cyclopterus lumpus) 

      Imsland, Albert; Danielsen, Mathias; Jonassen, Thor Magne; Hangstad, Thor Arne; Falk-Petersen, Inger-Britt (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-08-24)
      Two batches of lumpfish eggs were incubated at three temperature regimes; 1-Ambient seawater 4–6 °C (cold), 2-Ambient seawater for 10 days followed by a gradual increase to 10 °C (gradient), 3-Constant 10 °C seawater (warm). The eggs incubated in cold water had the highest egg mortality (38.5% ± 15.7) and lowest hatching success (46.1% ± 7.2), while the gradient group regime showed highest hatching ...
    • Mesopelagic sound scattering layers of the high Arctic: Seasonal variations in biomass, species assemblage, and trophic relationships 

      Geoffroy, Maxime; Daase, Malin; Cusa, Marine Lure Joana; Darnis, Gérald; Graeve, Martin; Santana Hernadez, Nestor; Berge, Jørgen; Renaud, Paul Eric; Cottier, Finlo Robert; Falk-Petersen, Stig (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-12)
      Mesopelagic sound scattering layers (SSL) are ubiquitous in all oceans. Pelagic organisms within the SSL play important roles as prey for higher trophic levels and in climate regulation through the biological carbon pump. Yet, the biomass and species composition of SSL in the Arctic Ocean remain poorly documented, particularly in winter. A multifrequency echosounder detected a SSL north of Svalbard, ...
    • Ambient temperature effects on stress-induced hyperthermia in Svalbard ptarmigan 

      Nord, Andreas; Folkow, Lars (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-20)
      Stress-induced hyperthermia (SIH) is commonly observed during handling in homeotherms. However, in birds, handling in cold environments typically elicits hypothermia. It is unclear whether this indicates that SIH is differently regulated in this taxon or if it is due to size, because body temperature changes during handling in low temperatures have only been measured in small birds <0.03 kg (that ...
    • Terrestrial locomotion of the Svalbard rock ptarmigan: comparing field and laboratory treadmill studies 

      Marmol-Guijarro, Andres C; Nudds, Robert L.; Marrin, John C; Folkow, Lars; Codd, Jonathan R (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-08-07)
      Research into the terrestrial locomotion of birds is often based upon laboratory treadmill experiments. However, it is unclear how transposable these results are for birds moving in the wild. Here, using video recordings, we compared the kinematics of locomotion (stride frequency, stride length, stance phase, swing phase, duty factor) and speed range of Svalbard rock ptarmigan (<i>Lagopus muta ...
    • The epidemiology of zoonotic brucellosis in Bahr el Ghazal region of South Sudan 

      Madut, Nuol Aywel; Muleme, James; Kankya, Clovice; Nasinyama, George William; Muma, John Bwalya; Godfroid, Jacques; Jubara, Ambrose Samuel; Muwonge, Adrian (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-26)
      <p><i>Background - </i>In this study, we focused on three zoonotic brucellosis risk groups; abattoir workers, febrile cases at Wau hospital and cattle herders, in Bahr el Ghazal region, South Sudan. Competitive c-ELISA was used to detect anti-<i>Brucella</i> antibodies in 725 individuals between December 2015 and May 2016. In addition, questionnaire metadata, focus group discussions and key informant ...
    • Phylogenetic Reclassification of Vertebrate Melatonin Receptors To Include Mel1d 

      Denker, Elsa; Ebbesson, Lars O.E.; Hazlerigg, David; Macqueen, Daniel J. (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-10-01)
      The circadian and seasonal actions of melatonin are mediated by high affinity G-protein coupled receptors (melatonin receptors, MTRs), classified into phylogenetically distinct subtypes based on sequence divergence and pharmacological characteristics. Three vertebrate MTR subtypes are currently described: MT1 (MTNR1A), MT2 (MTNR1B), and Mel1c (MTNR1C / GPR50), which exhibit distinct affinities, ...
    • Seasonal shifts in feeding patterns: Individual and population realized specialization in a high Arctic fish 

      Cusa, Marine Lure Joana; Berge, Jørgen; Varpe, Øystein (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-21)
      Species with a broad and flexible diet may be at an advantage in a rapidly changing environment such as in today's Arctic ecosystems. Polar cod (<i>Boreogadus saida</i>), an abundant and ecologically important circumpolar Arctic fish, is often described as a zooplankton generalist feeder, which suggests that it may cope successfully with changes in prey composition. This description is justified ...
    • The PI3K and MAPK/p38 pathways control stress granule assembly in a hierarchical manner 

      Heberle, Alexander Martin; Razquin Navas, Patricia; Langelaar-Makkinje, Miriam; Kasack, Katharina; Sadik, Ahmed; Faessler, Erik; Hahn, Udo; Marx-Stoelting, Philip; Opitz, Christiane A.; Sers, Christine; Heiland, Ines; Schaeuble, Sascha; Thedieck, Kathrin (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-03-28)
      All cells and organisms exhibit stress-coping mechanisms to ensure survival. Cytoplasmic protein-RNA assemblies termed stress granules are increasingly recognized to promote cellular survival under stress. Thus, they might represent tumor vulnerabilities that are currently poorly explored. The translation-inhibitory eIF2α kinases are established as main drivers of stress granule assembly. Using a ...
    • Multi-pathogen serological survey of migratory caribou herds: A snapshot in time 

      Carlsson, Anja M.; Curry, Patricia S.; Elkin, Brett T.; Russell, Donald E.; Veitch, Alasdair M.; Branigan, Marsha; Campbell, Mitch; Croft, Bruno; Cuyler, Christine; Côté, Steeve D.; Leclerc, Lise-Marie; Tryland, Morten; Nymo, Ingebjørg Helena; Kutz, Susan J. (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-31)
      Pathogens can impact host survival, fecundity, and population dynamics even when no obvious disease is observed. Few baseline data on pathogen prevalence and diversity of caribou are available, which hampers our ability to track changes over time and evaluate impacts on caribou health. Archived blood samples collected from ten migratory caribou herds in Canada and two in Greenland were used to test ...
    • The association between parasite infection and growth rates in Arctic charr: do fast growing fish have more parasites? 

      Henriksen, Eirik Haugstvedt; Smalås, Aslak; Strøm, John Fredrik; Knudsen, Rune (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-01-01)
      Trophically transmitted parasites are known to impair fish growth in experimental studies, but this is not well documented in natural populations. For Arctic charr [<i>Salvelinus alpinus</i> (L.)], individual growth is positively correlated with food consumption. However, increased food consumption will increase the exposure to trophically transmitted parasites. Using a correlative approach, we ...