11 research outputs found

    Acoustic micronektonic distribution and density is structured by macroscale oceanographic processes across 17–48° N latitudes in the North Atlantic Ocean

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    This study investigates the large-scale distribution patterns of the acoustic scattering layers and micronekton density across the Northeast Atlantic Ocean during daylight hours. A research cruise on board R/V “Kronprins Haakon” was conducted during May 2019 from Cape Verde to Bay of Biscay. Hydrological data were obtained at 20 conductivity-temperature-depth sensor (CTD) stations. To estimate the micronekton densities in front of the trawl, an autonomous echo sounder (120 or 200 kHz) on the headrope of the macroplankton trawl was used. Acoustic data were also collected along the cruise track using ship-mounted multi-frequency echo sounders (backscatter at 18 and 38 kHz was analyzed). Acoustic observations (both at 18, 38 and 120/200 kHz) showed clear patterns in the horizontal distribution of the micronekton during daytime with higher backscatter and echo densities in the south of the study area (from 17 to 37° N), and the absence of high backscatter in the surface from 37 to 45° N. Backscatter and echo densities were found to be significantly influenced by: temperature, salinity, and oxygen, as well as depth and time of the day.publishedVersio

    Pelagiske økosystem i De nordiske hav - grunnlagsstudie knyttet til åpningsprosess for utforskning og utvinning av havbunnsmineraler på norsk kontinentalsokkel

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    Denne rapporten er en leveranse til bestillingen «Grunnlagsstudie: Pelagisk økosystem» fra Oljedirektoratet til Havforskningsinstituttet. Studien er bestilt i forbindelse med at regjeringen har igangsatt en prosess for åpning av norsk sokkel for havbunnsmineralvirksomhet. Rapporten sammenstiller vår nåværende kunnskap om de pelagiske økosystemenes struktur og funksjon og belyser viktige kunnskapshull. Det er lagt særlig vekt på å beskrive økosystemkomponenter og prosesser som er essensielle for arbeidet med planprogram for konsekvensutredning av havbunnsmineralvirksomhet i norske havområder, og fokus vil derfor tidvis være litt annerledes enn det man vil finne i en generell beskrivelse av Norskehavet, Islandshavet og Grønlandshavet. Vi har lagt mer vekt på eksisterende kunnskapshull, og fokusert mer på utredningsområdet og på økologi og prosesser i pelagisk sone i dyphavet, enn det som kan forventes i for eksempel en lærebok om plankton-, fisk eller sjøpattedyrøkologi. Selv om formålet dermed har farget fokuset for beskrivelsene, beskriver kapitlene generell fordeling og økologi i de pelagiske systemene i Norskehavet, Islandshavet og Grønlandshavet.publishedVersio

    Pre-radiotherapy plasma carotenoids and markers of oxidative stress are associated with survival in head and neck squamous cell carcinoma patients: a prospective study

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    <p>Abstract</p> <p>Background</p> <p>The purpose of this study was to compare plasma levels of antioxidants and oxidative stress biomarkers in head and neck squamous cell carcinoma (HNSCC) patients with healthy controls. Furthermore, the effect of radiotherapy on these biomarkers and their association with survival in HNSCC patients were investigated.</p> <p>Methods</p> <p>Seventy-eight HNSCC patients and 100 healthy controls were included in this study. Follow-up samples at the end of radiotherapy were obtained in 60 patients. Fifteen antioxidant biomarkers (6 carotenoids, 4 tocopherols, ascorbic acid, total antioxidant capacity, glutathione redox potential, total glutathione and total cysteine) and four oxidative stress biomarkers (total hydroperoxides, γ-glutamyl transpeptidase, 8-isoprostagladin F<sub>2α </sub>and ratio of oxidized/total ascorbic acid) were measured in plasma samples. Analysis of Covariance was used to compare biomarkers between patients and healthy controls. Kaplan-Meier plots and Cox' proportional hazards models were used to study survival among patients.</p> <p>Results</p> <p>Dietary antioxidants (carotenoids, tocopherols and ascorbic acid), ferric reducing antioxidant power (FRAP) and modified FRAP were lower in HNSCC patients compared to controls and dietary antioxidants decreased during radiotherapy. Total hydroperoxides (d-ROMs), a marker for oxidative stress, were higher in HNSCC patients compared to controls and increased during radiotherapy. Among the biomarkers analyzed, high levels of plasma carotenoids before radiotherapy are associated with a prolonged progression-free survival (hazard rate ratio: 0.42, 95% CI: 0.20-0.91, p = 0.03). Additionally, high relative increase in plasma levels of d-ROMs (hazard rate ratio: 0.31, 95% CI: 0.13-0.76, p = 0.01) and high relative decrease in FRAP (hazard rate ratio: 0.42, 95% CI: 0.17-0.998, p = 0.05) during radiotherapy are also positively associated with survival.</p> <p>Conclusions</p> <p>Biomarkers of antioxidants and oxidative stress are unfavourable in HNSCC patients compared to healthy controls, and radiotherapy affects many of these biomarkers. Increasing levels of antioxidant biomarkers before radiotherapy and increasing oxidative stress during radiotherapy may improve survival indicating that different factors/mechanisms may be important for survival before and during radiotherapy in HNSCC patients. Thus, the therapeutic potential of optimizing antioxidant status and oxidative stress should be explored further in these patients.</p
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