Viser treff 1-20 av 2021

    • Seroprevalence and risk factors of brucellosis in pastoralists and their livestock in Central Equatoria State, South Sudan 

      Lita, Emmanuel P.; Ochi, Erneo B.; Misinzo, Gerald; van Heerden, Henriette; Katani, Robab; Godfroid, Jacques Xavier Leon; Mathew, Coletha (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-12-19)
      Background Brucellosis poses serious public health implications and substantial economic losses in pastoral rural settings in South Sudan. In humans, brucellosis is almost always originating from animals. Current literature provides scant data regarding the seroprevalence of brucellosis in South Sudan. This cross-sectional study investigates the seroprevalence of brucellosis among the pastoral ...
    • Contrasting two major Arctic coastal polynyas: the role of sea ice in driving diel vertical migrations of zooplankton in the Laptev and Beaufort seas 

      Dmitrenko, Igor A.; Petrusevich, Vladislav; Preußer, Andreas; Kosobokova, Ksenia; Bouchard, Caroline; Geoffroy, Maxime; Komarov, Alexander S.; Babb, David G.; Kirillov, Sergei A.; Barber, David G. (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-12-17)
      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. Previously thought to be hampered by the extreme light regime prevailing in the Arctic Ocean, observations have revealed that DVM does occur in ice-covered Arctic waters and suggest the decline in Arctic sea ice may thereby ...
    • Seasonal changes in the feeding aggregation structure of male sperm whales (Physeter macrocephalus) in Northern Norway 

      Morange, Zoë Luccia Juliette; Similä, Tiu; Rikardsen, Audun H.; Blanchet, Marie-Anne (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-12-25)
      The sperm whale (Physeter macrocephalus) is one of the most widely distributed cetaceans. Adult males commonly occupy high latitudes, whereas females and juveniles occupy lower latitudes. In Northern Norway, previous studies focused on the summer period limiting our understanding of the seasonal dynamics of male foraging aggregations. We used year-round capture–mark–recapture data based on photo ...
    • Takvatnprosjektet – vellykket samarbeid mellom forskere og fiskeentusiaster 

      Amundsen, Per-Arne; Knudsen, Rune; Kristoffersen, Roar; Henriksen, Eirik H.; Smalås, Aslak; Primicerio, Raul; Johannessen, Karin Strand; Bye, Cesilie; DalsbØ, laina h; Klemetsen, Anders (Journal article; Tidsskriftartikkel; Peer reviewed, 2024)
      Overbefolka fiskebestander er et stort problem i mange innsjøer, særlig for røye, ørret, abbor og sik. Kjennetegnet er småvokst og mager fisk, gjerne med høy infeksjon av parasitter. Som et potensielt botemiddel ble et storstilt uttynningsfiske med teiner iverksatt i Takvatn (15 km2), Troms, på 1980-tallet. I nært samarbeid mellom forskere, grunneiere og fiskere ble 700.000 smårøye (31.3 tonn) tatt ...
    • Extreme mismatch between phytoplankton and grazers during Arctic spring blooms and consequences for the pelagic food-web 

      Renaud, Paul Eric; Daase, Malin Hildegard Elisabeth; Leu, Eva Susanne; Geoffroy, Maxime; Basedow, Sünnje Linnéa; Inall, Mark; Campbell, Karley Lynn; Trudnowska, Emilia; Sandbank, Einat; Cnossen, Frida Anneke; Dunn, Muriel Barbara; Camus, Lionel; Porter, Marie; Aune, Magnus; Gradinger, Rolf Rudolf (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-10-13)
      Food-web structure determines the cycling pathways and fate of new production in marine ecosystems. Herbivorous zooplankton populations are usually seasonally coupled with pelagic primary producers. Synchrony of phytoplankton blooms with reproduction, recruitment and seasonal ascent of their main grazers ensures efficient transfer of organic carbon to higher trophic levels, including commercially ...
    • One organ to infect them all: the Cuscuta haustorium 

      Balios, Vasili Alexander; Fischer, Karsten; Bawin, Thomas Georges A; Krause, Kirsten (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-12-02)
      Background - Research on the parasitic plant genus Cuscuta has flourished since the genomes of several of its species were published. Most of the research revolves around the iconic infection organ that secures the parasite’s sustenance: the haustorium. Interest in understanding the structure–function–regulation relationship of the haustorium is based as much on the wish to find ways to keep the ...
    • Macroecological patterns of rodent population dynamics shaped by bioclimatic gradients 

      Soininen, Eeva M; Magnusson, Magnus; Jepsen, Jane Uhd; Eide, Nina Elisabeth; Yoccoz, Nigel Gilles; Angerbjörn, Anders; Breisjøberget, Jo Inge; Ecke, Frauke; Ehrich, Dorothee; Framstad, Erik; Henttonen, Heikki; Hörnfeldt, Birger; Killengreen, Siw Turid; Olofsson, Johan; Oksanen, Lauri; Oksanen, Tarja Maarit; Tveito, Ole Einar Ellingbø (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-12-27)
      Long-term studies of cyclic rodent populations have contributed fundamentally to the development of population ecology. Pioneering rodent studies have shown macroecological patterns of population dynamics in relation to latitude and have inspired similar studies in several other taxa. Nevertheless, such studies have not been able to disentangle the role of different environmental variables in shaping ...
    • Goose grubbing and warming suppress summer net ecosystem CO2 uptake differentially across high-Arctic tundra habitats 

      Petit Bon, Matteo; Beard, Karen H.; Braathen, Kari Anne; Lee, Hanna; Jonsdottir, Ingibjørg (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-12-09)
      Environmental changes, such as climate warming and higher herbivory pressure, are altering the carbon balance of Arctic ecosystems; yet, how these drivers modify the carbon balance among different habitats remains uncertain. This hampers our ability to predict changes in the carbon sink strength of tundra ecosystems. We investigated how spring goose grubbing and summer warming—two key environmental-change ...
    • Hydrochemical characterization and sustainability assessment of Ismailia canal water, Eastern Nile Delta, Egypt: implications for human health and environmental safety 

      El-Said Salem, Zenhom; Attiah, Abdullah Muhammad; Abu Alam, Tamer Sabry Zaki (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-11-11)
      Surface freshwater systems globally face severe stresses due to overpopulation and associated waste. The Ismailia Canal, a crucial freshwater source in the eastern Nile Delta, Egypt, serves multiple purposes and is endangered by various environmental activities. This study characterizes the canal’s water using physicochemical parameters to evaluate its suitability for different uses. Water samples ...
    • Transcriptomic profiling of gill biopsies to define predictive markers for seawater survival in farmed Atlantic salmon 

      Grønvold, Lars; van Dalum, Mattis J.; Striberny, Anja; Manous, Domniki; Ytrestøyl, Trine; Mørkøre, Turid; Boison, Solomon Antwi; Gjerde, Bjarne; Jørgensen, Even; Sandve, Simen Rød; Hazlerigg, David Grey (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-12-16)
      Wild Atlantic salmon migrate to sea following completion of a developmental process known as parr-smolt transformation (PST), which establishes a seawater (SW) tolerant phenotype. Effective imitation of this aspect of anadromous life history is a crucial aspect of commercial salmon production, with current industry practice being marred by significant losses during transition from the freshwater ...
    • Loss of pelagic fish and zooplankton density associated with subglacial upwelling in high Arctic estuaries may be mitigated by benthic habitat expansion following tidewater glacier retreat 

      Gonzalez Triginer, Victor; Sen, Arunima; Geoffroy, Maxime; Damsgård, Børge (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-10-23)
      Glacier fronts are hotspots of pelagic productivity due to upwelling of nutrient-rich water. As tidewater glaciers retreat into land, this subglacial circulation will disappear and sedimentation from terrestrial runoff will increase, leading to a decrease in pelagic productivity with a decline in the abundance of fish and zooplankton. We used Billefjorden, a high Arctic fjord with a glacier recently ...
    • Bycatch of northern fulmar (Fulmarus glacialis) in Norwegian longline fisheries: Assessing spatiotemporal variations in scale and risk to improve management 

      Clegg, Tom L.; Christensen-Dalsgaard, Signe; Bråthen, Vegard Sandøy; Tarroux, Arnaud; Danielsen, Jóhannis; Descamps, Sebastien; Follestad, Arne; Hallgrimsson, Gunnar Thor; Helberg, Morten; Helgason, Hálfdán H.; Jónsson, Jón Einar; Kolbeinsson, Yann; Strøm, Hallvard; Thompson, Paul; Thórarinsson, Thorkell Lindberg; Williams, Tom; Bærum, Kim Magnus (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-12-09)
      Seabirds are vulnerable to bycatch in longline fisheries but for most species the impacts are largely unknown. To address this knowledge gap, studies can estimate bycatch directly using observations or calculate the theoretical risk of bycatch using overlap indexes. Here we quantify the scale and risk of bycatch of northern fulmar (Fulmarus glacialis) in the Norwegian offshore longline fishery using ...
    • Taking the beat of the Arctic: are lemming population cycles changing due to winter climate? 

      Gauthier, Gilles; Ehrich, Dorothee; Belke-Brea, Maria; Dominé, Florent; Alisauskas, Ray; Clark, Karin; Ecke, Frauke; Eide, Nina Elisabeth; Framstad, Erik; Frandsen, Jay; Gilg, Olivier; Henttonen, Heikki; Hörnfeldt, Birger; Kataev, Gennadiy D.; Menyushina, Irina E.; Oksanen, Lauri; Oksanen, Tarja Maarit; Olofsson, Johan; Samelius, Gustaf; Sittler, Benoit; Smith, Paul A.; Sokolov, Aleksandr A.; Sokolova, Natalia A.; Schmidt, Niels M. (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-02-14)
      Reports of fading vole and lemming population cycles and persisting low populations in some parts of the Arctic have raised concerns about the spread of these fundamental changes to tundra food web dynamics. By compiling 24 unique time series of lemming population fluctuations across the circumpolar region, we show that virtually all populations displayed alternating periods of cyclic/non-cyclic ...
    • Redescription of Proteocephalus fallax La Rue, 1911 (Cestoda) and a list of proteocephalid tapeworms of whitefish (Coregonus spp.) 

      Scholz, Tomáš; de Chambrier, Alain; Brabec, Jan; Knudsen, Rune; Costa, Isabel Blasco (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-10-22)
      Tapeworms of the genus Proteocephalus Weinland, 1858 (Cestoda: Proteocephalidae) are common and widespread intestinal parasites of whitefish (Coregonus spp., Salmonidae: Coregoninae). Previous taxonomic studies, based solely on morphology and inconsistently fixed specimens, concluded that all salmoniform fish, including whitefish, are parasitised by a single euryxenous and highly polymorphic ...
    • Determination of zooplankton absorption spectra and their potential contribution to ocean color 

      McCarry, Cait L.; Basedow, Sünnje Linnéa; Davies, Emlyn John; Last, Kim S.; McKee, David (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-10-29)
      Zooplankton are keystone organisms that provide a critical link between primary production and higher-order predators in the marine food web, as well as facilitating the sequestration of carbon within the ocean. In this context, there is considerable interest in the detection of zooplankton swarms from satellite ocean color signals. However, for this to be possible, accurate inherent optical ...
    • Advancing hyperspectral imaging techniques for root systems: a new pipeline for macro- and microscale image acquisition and classification 

      Faehn, Corine Alexis; Konert, Grzegorz; Keinänen, Markku; Karppinen, Katja Hannele; Krause, Kirsten (Journal article; Tidsskriftartikkel; Peer reviewed; Doctoral thesis, 2024-11-11)
      Background Understanding the environmental impacts on root growth and root health is essential for effective agricultural and environmental management. Hyperspectral imaging (HSI) technology provides a non-destructive method for detailed analysis and monitoring of plant tissues and organ development, but unfortunately examples for its application to root systems and the root-soil interface are ...
    • Analysis of Bacterial Communities associated with the Tidal Zone Grass Puccinellia in Response to Diesel Spills 

      Freyer, Judith Marie (Master thesis; Mastergradsoppgave, 2024-11-15)
      Contamination from petroleum products and hydrocarbons is one of the major sources of pollution worldwide. The use of plants or microbes to reduce pollution is called bioremediation and is a cheap and environmentally friendly alternative to mechanical or chemical clean-up. A good understanding of native plants and microbes is required to implement bioremediation. In this study, the common and ...
    • Physiological impact of waterborne crude oil exposure to reproducing polar cod (Boreogadus saida) 

      Cremer, Ricarda (Master thesis; Mastergradsoppgave, 2024-11-15)
      Climate change-driven sea ice decline is increasing access to Arctic oil reserves and shipping routes, raising the risk of oil spills. Harsh polar conditions of extreme cold, darkness, and unpredictable weather will exacerbate these risks. The polar cod (Boreogadus saida), a key species in the Arctic ecosystem, may be particularly affected. With its spawning window in January and February, an oil ...
    • Studier av opptak av fiskepatogene bakterier i keratocytter fra laks og «Atlantic salmon kidney» (ASK) celler 

      Elde, Christiane Lovise (Master thesis; Mastergradsoppgave, 2023-12-01)
      Hudsår har blitt mer utbredt i norsk lakseoppdrett de senere år, hvor årsakene kan være flere og sammensatte. Vintersår regnes som en av de største helseutfordringene, der klassiske vintersår knyttes til bakterien Moritella viscosa. Hudsår hos oppdrettsfisk kan også skyldes sammensatt infeksjon med flere bakterier hvor bakteriene Vibrio anguillarum, Vibrio salmonicida og Aeromonas salmonicida, som ...
    • Chemolithoautotrophic bacteria flourish at dark water–ice interfaces of an emerged Arctic cold seep 

      Delpech, Lisa-Marie; Tveit, Alexander Tøsdal; Hodson, Andrew; Hand, Kevin P.; Kalenitchenko, Dimitri Stanislas Desire (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-09-12)
      Below their ice shells, icy moons may offer a source of chemical energy that could support microbial life in the absence of light. In the Arctic, past and present glacial retreat leads to isostatic uplift of sediments through which cold and methane-saturated groundwater travels. This fluid reaches the surface and freezes as hill-shaped icings during winter, producing dark ice–water interfaces above ...