Viser treff 189-208 av 1515

    • Characterizing cytotoxic and estrogenic activity of Arctic char tissue extracts in primary Arctic char hepatocytes 

      Petersen, Karina; Hultman, Maria Thérése; Bytingsvik, Jenny; Harju, Mikael; Evenset, Anita; Tollefsen, Knut Erik (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-09-01)
      Contaminants from various anthropogenic activities are detected in the Arctic due to long-range atmospheric transport, ocean currents, and living organisms such as migrating fish or seabirds. Although levels of persistent organic pollutants (POPs) in Arctic fish are generally low, local hot spots of contamination were found in freshwater systems such as Lake Ellasjøen at Bjørnøya (Bear Island, ...
    • Chemical Diversity as a Function of Temperature in Six Northern Diatom Species 

      Huseby, Siv; Degerlund, Maria; Eriksen, Gunilla Kristina; Ingebrigtsen, Richard Andre; Eilertsen, Hans Christian; Hansen, Espen (Journal article; Tidsskriftartikkel; Peer reviewed, 2013)
      In this study, we investigate how metabolic fingerprints are related to temperature. Six common northern temperate diatoms (Attheya longicornis, Chaetoceros socialis, Chaetoceros furcellatus, Porosira glacialis, Skeletonema marinoi, and Thalassiosira gravida) were cultivated at two different temperatures, 0.5 and 8.5 °C. To exclude metabolic variations due to differences in growth rates, the growth ...
    • Chemosynthetic and photosynthetic trophic support from cold seeps in Arctic benthic communities 

      Åström, Emmelie; Bluhm, Bodil; Rasmussen, Tine Lander (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-08-17)
      Benthic communities below the photic zone are largely reliant on the export of surface-water primary production and the flux of partially degraded organic matter to the seabed, i.e. pelagic−benthic coupling. Over the past decades, however, the role of chemosynthetically produced carbon in food webs has been recognized in various habitats. Cold seeps are now known to be widespread across circumpolar ...
    • The Chloroplast Ribonucleoprotein CP33B Quantitatively Binds the psbA mRNA 

      Teubner, Marlene; Lenzen, Benjamin; Espenberger, Lucas Bernal; Fuss, Janina; Nickelsen, Jörg; Krause, Kirsten; Ruwe, Hannes; Schmitz-Linneweber, Christian (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-17)
      Chloroplast RNAs are stabilized and processed by a multitude of nuclear-encoded RNA-binding proteins, often in response to external stimuli like light and temperature. A particularly interesting RNA-based regulation occurs with the <i>psbA</i> mRNA, which shows light-dependent translation. Recently, the chloroplast ribonucleoprotein CP33B was identified as a ligand of the <i>psbA</i> mRNA. We here ...
    • Choose your poison – Space-use strategy influences pollutant exposure in Barents Sea polar bears 

      Tartu, Sabrina; Aars, Jon; Andersen, Magnus; Polder, Anuschka; Bourgeon, Sophie; Merkel, Benjamin; Lowther, Andrew D.; Bytingsvik, Jenny; Welker, Jeffrey Martin; Derocher, Andrew E.; Jenssen, Bjørn Munro; Routti, Heli (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-01-24)
      Variation in space-use is common within mammal populations. In polar bears, Ursus maritimus, some individuals follow the sea ice (offshore bears) whereas others remain nearshore yearlong (coastal bears). We studied pollutant exposure in relation to space-use patterns (offshore vs coastal) in adult female polar bears from the Barents Sea equipped with satellite collars (2000–2014, n = 152). First, ...
    • Chronological changes in soil biogeochemical properties of the glacier foreland of Midtre Lovénbreen, Svalbard, attributed to soil-forming factors 

      Kim, You Jin; Laffly, Dominique; Kim, Se-eun; Nilsen, Lennart; Chi, Junhwa; Nam, Sungjin; Lee, Yong Bok; Jeong, Sujeong; Mishra, Umakant; Lee, Yoo Kyung; Jung, Ji Young (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-21)
      Glacier forelands provide an excellent opportunity to investigate vegetation succession and soil development along the chronosequence; however, there are few studies on soil biogeochemical changes from environmental factors, aside from time. This study aimed to investigate soil development and biogeochemical changes in the glacier foreland of Midtre Lov ́enbreen, Svalbard, by considering various ...
    • Cicadas in Japanese video games and anime 

      Salvador, Rodrigo Brincalepe (Journal article; Tidsskriftartikkel; Peer reviewed, 2022)
      If you ever watched an anime, chances are at some point you have heard an incessant buzzing sound in the background. Those are cicadas, the sound of summer in Japan. Summer only truly arrives when the cicadas start singing (Kendall, 2014).<p> <p>Whenever it is summer in an anime, TV series, movie, or game, you can be almost sure to hear cicadas on the background. Their sound is an easy and ...
    • Circadian clock mechanism driving mammalian photoperiodism 

      Wood, Shona Hiedi; Hindle, Matthew; Mizoro, Yasutaka; Cheng, Y; Saer, Ben; Miedzinska, K; Christian, Helen; Begley, Nicola; McNeilly, Judy; McNeilly, Alan; Meddle, Simone; Burt, Dave; Loudon, Andrew S.I. (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-27)
      The annual photoperiod cycle provides the critical environmental cue synchronizing rhythms of life in seasonal habitats. In 1936, Bünning proposed a circadian-based coincidence timer for photoperiodic synchronization in plants. Formal studies support the universality of this so-called coincidence timer, but we lack understanding of the mechanisms involved. Here we show in mammals that long photoperiods ...
    • Circuit-level analysis identifies target genes of sex steroids in ewe seasonal breeding 

      Lomet, Didier; Druart, Xavier; Hazlerigg, David; Beltramo, Massimiliano; Dardente, Hugues (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05-15)
      Thyroid hormone (TH) and estradiol (E2) direct seasonal switches in ovine reproductive physiology. In sheep, as in other mammals and birds, control of thyrotropin (TSH) production by the pars tuberalis (PT) links photoperiod responsiveness to seasonal breeding. PT-derived TSH governs opposite seasonal patterns of the TH deiodinases Dio2/Dio3 expression in tanycytes of the neighboring medio-basal ...
    • Circum-Arctic distribution of chemical anti-herbivore compounds suggests biome-wide trade-off in defence strategies in Arctic shrubs 

      Lindén, Elin; te Beest, Mariska; Aubreu, Ilka; Moritz, Thomas; Sundqvist, Maja K.; Barrio, Isabel C.; Boike, Julia; Bryant, John P.; Bråthen, Kari Anne; Buchwal, Agata; Bueno, C. Guillermo; Currier, Alain; Egelkraut, Dagmar Dorothea; Forbes, Bruce C.; Hallinger, Martin; Heijmans, Monique; Hermanutz, Luise; Hik, David S.; Hofgaard, Annika; Holmgren, Milena; Huebner, Diane C.; Høye, Toke T.; Jónsdóttir, Ingibjörg S.; Kaarlejärvi, Elina; Kissler, Emilie; Kumpula, Timo; Limpens, Juul; Myers-Smith, Isla H.; Normand, Signe; Post, Eric; Rocha, Adrian V.; Schmidt, Niels Martin; Skarin, Anna; Soininen, Eeva M; Sokolov, Aleksandr; Sokolova, Natalia; Speed, James David Mervyn; Street, Lorna E.; Tananaev, Nikita; Tremblay, Jean-Pierre; Urbanowicz, Christine; Watts, David A.; Zimmermann, Heike H.; Olofsson, Johan (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-08-30)
      Spatial variation in plant chemical defence towards herbivores can help us understand variation in herbivore top–down control of shrubs in the Arctic and possibly also shrub responses to global warming. Less defended, non-resinous shrubs could be more influenced by herbivores than more defended, resinous shrubs. However, sparse field measurements limit our current understanding of how much of the ...
    • Circumpolar dynamics of a marine top-predator track ocean warming rates. 

      Descamps, Sebastian; Anker-Nilssen, Tycho; Barrett, Robert T.; Irons, D.; Merkel, Flemming; Robertson, Gregory J.; Yoccoz, Nigel Gilles; Mallory, Mark L.; Montevecchi, William A.; Boertmann, D.; Artukhin, Yuri; Christensen-Dalsgaard, Signe; Erikstad, Kjell E.; Gilchrist, H. Grant; Labansen, Aili; Lorentsen, Svein Håkon; Mosbech, Anders; Olsen, Bergur; Petersen, Aevar; Rail, Jean-Francois; Renner, Heather M.; Strøm, H.; Systad, Geir Helge; Wilhelm, Sabina I.; Zelenskaya, Larisa (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-07)
      Global warming is a nonlinear process, and temperature may increase in a stepwise manner. Periods of abrupt warming can trigger persistent changes in the state of ecosystems, also called regime shifts. The responses of organisms to abrupt warming and associated regime shifts can be unlike responses to periods of slow or moderate change. Understanding of nonlinearity in the biological responses to ...
    • The circumpolar impacts of climate change and anthropogenic stressors on Arctic cod (Boreogadus saida) and its ecosystem 

      Geoffroy, Maxime; Bouchard, Caroline; Flores, Hauke; Robert, Dominique; Gjøsæter, Harald; Hoover, Carie; Hop, Haakon; Hussey, Nigel E.; Nahrgang, Jasmine; Steiner, Nadja; Bender, Morgan; Berge, Jørgen; Castellani, Giulina; Chernova, Natalia; Copeman, Louise; David, Carmen; Deary, Alison; Divoky, George; Dolgov, Andrey; Duffy-Anderson, Janet; Dupont, Nicolas; Durant, Joël M.; Elliott, Kyle; Gauthier, Stéphane; Goldstein, Esther D.; Rolf, Gradinger; Hedges, Kevin; Herbig, Jennifer; Laurel, Ben; Loseto, Lisa; Maes, Sarah; Mark, Felix; Mosbech, Anders; Pedro, Sara; Petitt-Wade, Harri; Prokopchuk, Irina; Paul E, Renaud; Schembri, Sarah; Vestfals, Cathleen; Walkusz, Wojciech (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-08)
      Arctic cod biomass are predicted. In most Arctic seas, the relative abundance of Arctic cod within the fish community will likely fluctuate in accordance with cold and warm periods. A reduced abundance of Arctic cod will negatively affect the abundance, distribution, and physiological condition of certain predators, whereas some predators will successfully adapt to a more boreal diet. Regional ...
    • Circumpolar patterns of Arctic freshwater fish biodiversity: A baseline for monitoring 

      Laske, Sarah M.; Amundsen, Per-Arne; Christoffersen, Kirsten Seestern; Erkinaro, Jaakko; Guðbergsson, Guðni; Hayden, Brian; Heino, Jani; Holmgren, Kerstin; Kahilainen, Kimmo Kalevi; Lento, Jennifer; Orell, Panu; Östergren, Jan; Power, Michael; Rafikov, Ruslan; Romakkaniemi, Atso; Svenning, Martin; Swanson, Heidi; Whitman, Matthew; Zimmerman, Christian E. (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-10-01)
      Climate change, biological invasions, and anthropogenic disturbance pose a threat to the biodiversity and function of Arctic freshwater ecosystems. Understanding potential changes in fish species distribution and richness is necessary, given the great importance of fish to the function of freshwater ecosystems and as a resource to humans. However, information gaps limit large‐scale studies and our ...
    • Climate change impacts on sea-ice ecosystems and associated ecosystem services 

      Steiner, Nadja S.; Bowman, Jeff; Campbell, Karley; Chierici, Melissa; Eronen-Rasimus, Eeva; Falardeau, Marianne; Flores, Hauke; Fransson, Agneta; Herr, Helena; Insley, Stephen J.; Kauko, Hanna M.; Lannuzel, Delphine; Loseto, Lisa; Lynnes, Amanda; Majewski, Andy; Meiners, Klaus M.; Miller, Lisa A.; Michel, Loïc N.; Moreau, Sebastien; Nacke, Melissa; Nomura, Daiki; Tedesco, Letizia; van Franeker, Jan Andries; van Leeuwe, Maria A.; Wongpan, Pat (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-13)
      A rigorous synthesis of the sea-ice ecosystem and linked ecosystem services highlights that the sea-ice ecosystem supports all 4 ecosystem service categories, that sea-ice ecosystems meet the criteria for ecologically or biologically significant marine areas, that global emissions driving climate change are directly linked to the demise of sea-ice ecosystems and its ecosystem services, and that the ...
    • Climate Events Synchronize the Dynamics of a Resident Vertebrate Community in the High Arctic 

      Hansen, Brage Bremset; Grøtan, Vidar; Aanes, Ronny; Sæther, Bernt-Erik; Stien, Audun; Fuglei, Eva; Ims, Rolf Anker; Yoccoz, Nigel; Pedersen, Åshild Ønvik (Peer reviewed; Research report; Forskningsrapport, 2013-01-18)
      Recently accumulated evidence has documented a climate impact on the demography and dynamics of single species, yet the impact at the community level is poorly understood. Here, we show that in Svalbard in the high Arctic, extreme weather events synchronize population fluctuations across an entire community of resident vertebrate herbivores and cause lagged correlations with the secondary consumer, ...
    • Climate variability and density-dependent population dynamics: Lessons from a simple High Arctic ecosystem 

      Fauteux, Dominique; Stien, Audun; Yoccoz, Nigel; Fuglei, Eva; Ims, Rolf Anker (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-09-09)
      Ecologists are still puzzled by the diverse population dynamics of herbivorous small mammals that range from high-amplitude, multiannual cycles to stable dynamics. Theory predicts that this diversity results from combinations of climatic seasonality, weather stochasticity, and density-dependent food web interactions. The almost ubiquitous 3- to 5-y cycles in boreal and arctic climates may theoretically ...
    • Climate warming enhances polar cod recruitment, at least transiently 

      Bouchard, Caroline; Geoffroy, Maxime; LeBlanc, Mathieu; Majewski, Andrew; Gauthier, Stéphane; Walkusz, Wojciech; Reist, James D.; Fortier, Louis (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06-27)
      Polar cod (Boreogadus saida) is the dominant forage fish in Arctic seas and the main prey of the ringed seal (Pusa hispida), the beluga (Delphinapterus leucas) and several seabird species. Changes in the abundance of polar cod will have cascading effects on arctic marine ecosystems. We tested the hypothesis that an earlier sea ice breakup and warmer sea surface temperatures (SST) in spring-summer ...
    • Coastal Polynya Disrupts the Acoustic Backscatter Diurnal Signal Over the Eastern Laptev Sea Shelf 

      Dmitrenko, Igor A.; Petrusevich, Vladislav; Kosobokova, Ksenia; Komarov, Alexander S.; Bouchard, Caroline; Geoffroy, Maxime; Koldunov, Nikolay V.; Babb, David G.; Kirillov, Sergey A.; Barber, David G. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-12-16)
      The diel vertical migration (DVM) of zooplankton is one of the largest species migrations to occur globally and is a key driver of regional ecosystems and the marine carbon pump. The dramatic changes in the Arctic environment in recent years, mainly associated with sea-ice decline, may have wide significance for the Arctic shelf ecosystems including DVM. Observations have revealed the occurrence of ...
    • Cold acclimation in warmer extended autumns impairs freezing tolerance of perennial ryegrass (Lolium perenne) and timothy (Phleum pratense) 

      Dalmannsdottir, Sigridur; Jørgensen, Marit; Rapacz, Marcin; Østrem, Liv; Larsen, Arild; Rødven, Rolf; Rognli, Odd Arne (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-02-01)
      The effect of variable autumn temperatures in combination with decreasing irradiance and daylength on photosynthesis, growth cessation and freezing tolerance was investigated in northern- and southern3 adapted populations of perennial ryegrass (Lolium perenne L.) and timothy (Phleum pratense L.) intended for use in regions at northern high latitudes. Plants were subjected to three different acclimation ...
    • Cold Seeps in a Warming Arctic: Insights for Benthic Ecology 

      Åström, Emmelie; Sen, Arunima; Carroll, Michael Leslie; Carroll, JoLynn (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05-21)
      Cold-seep benthic communities in the Arctic exist at the nexus of two extreme environments; one reflecting the harsh physical extremes of the Arctic environment and another reflecting the chemical extremes and strong environmental gradients associated with seafloor seepage of methane and toxic sulfide-enriched sediments. Recent ecological investigations of cold seeps at numerous locations on the ...