Toktrapport fra det norsk/russiske økotoktet i Barentshavet og nærliggende områder

The aim of the joint Norwegian/Russian ecosystem survey in the Barents Sea and adjacent waters, August-October (BESS) is to monitor the status and changes in the Barents Sea ecosystem and provide data to support stock advice and research. The survey has since 2004 been conducted annually in the autumn, as a collaboration between the Institute of Marine Research (IMR) in Norway and the Polar branch of the VNIRO (PINRO) in Russia. The general survey plan and tasks were agreed upon at the annual IMR-PINRO Meeting in March 2022. Ship routes and other technical details are agreed on by correspondence between the survey coordinators. BESS aims at covering the entire Barents Sea. Ecosystem stations are distributed in a 35×35 nautical mile regular grid, and the ship tracks follow this design. Exceptions are the area around Svalbard (Spitsbergen), some additional bottom trawl hauls for demersal fish survey indices estimation, and additional acoustic transects for the capelin stock size estimation. Survey start for the Russian vessel was significantly delayed, resulting in REEZ being covered two-three months later than NEEZ. This resulted in reduced area coverage, decrease in the numbers of trawl hauls, and lack of standard pelagic trawl sampling. In NEEZ, RV “Kronprins Haakon” was cancelled due to difficult economic situation, making it necessary to allocate one of the two remaining vessels to the area west and north of Svalbard (Spitsbergen). This resulted in low coverage in this area, and problems with synoptic coverage in north-east of Svalbard (Spitsbergen) and thus increased uncertainty in assessment of demersal fish (e.g. Greenland halibut) and capelin. The 19-th joint Barents Sea autumn Ecosystem Survey (BESS) was carried out in two periods. The Norwegian research vessels “G.O. Sars” and “Johan Hjort” covered NEEZ in the period 16-th August to 03-th October, providing data to stock assessment, 0-group fish abundance indices, and state and changes descriptions which is comparable with earlier survey years in NEEZ. The Russian research vessel “Vilnyus” covered REEZ in the periods 20-th to 30-th September and 22-th October to 3-rd December. Survey coordinators in 2022 were Dmitry Prozorkevich (PINRO) and Geir Odd Johansen (IMR). Exchange of Russian and Norwegian experts between each country’s respective vessels did not take place in 2022. We would like to express our sincere gratitude to all the crew and scientific personnel onboard RVs “Vilnyus”, “G.O. Sars” and “Johan Hjort” for their dedicated work, as well as all the people involved in planning and reporting of BESS 2022. This report is a summary of observations and status assessment based on the survey data. Even though the survey was not well completed, the data obtained are the main source of knowledge about the ecosystem of the Barents Sea.Survey report from the joint Norwegian/Russian Ecosystem Survey in the Barents Sea and the adjacent waters August- December 2022publishedVersio

Forurensning i de norske havområdene - Barentshavet, Norskehavet og Nordsjøen - Rapport fra Overvåkingsgruppen 2021

Denne rapporten sammenstiller kunnskap om forurensningstilstanden i forvaltningsplanområdene Barentshavet, Norskehavet og Nordsjøen/Skagerrak, med hovedvekt på miljøgifter og radioaktiv forurensning. Rapporten oppsummerer resultater fra overvåkning av Overvåkingsgruppens indikatorsett, som publiseres på miljostatus.no, det vil si 43 indikatorer for forurensning og fire indikatorer for potensielt forurensende menneskelig aktivitet i havområdene. Rapporten inneholder også annen relevant kunnskap. Det er også gjort en evaluering av indikatorsettet og de ulike indikatorenes egnethet til å vurdere tilstand, utvikling og effekter på mattrygghet og miljøkvalitet.publishedVersio

First results from the L3+C experiment at CERN

The L3+C experiment combines the high-precision spectrometer of the L3 detector at LEP, CERN, with a small air shower array. The momenta of cosmic ray induced muons can be measured from 20 to 2000 GeV/c. During the 1999 data taking period 5 billion muon events were recorded in the spectrometer. From April until mid Summer 2000 an additional 3 billion muon events have been recorded as well as 25 million air shower events. Here the first results on the muon momentum spectrum and charge ratio will be presented

Status for miljøet i norske havområder - Rapport fra Overvåkingsgruppen 2023

I denne rapporten gir Overvåkingsgruppen, for første gang, en felles vurdering av miljøtilstanden i Barentshavet og havområdene utenfor Lofoten, Norskehavet og Nordsjøen med Skagerrak. Det er også første rapport som bruker resultater fra det nylig utviklede fagsystemet for vurdering av økologisk tilstand. I denne rapporten dekkes to hovedtemaer: (1) Dominerende trekk i status og utvikling i økosystemet i alle tre havområdene, basert på vurderingene av økologisk tilstand, Overvåkingsgruppens rapport om forurensning fra 2022, indikatorer fra Overvåkingsgruppen som ikke er dekket under vurdering av økologisk tilstand, samt rapporter og annen relevant informasjon fra forskning, og (2) en vurdering av karbonbinding i marint plankton, marine vegetasjonstyper og marine sedimenter. I tillegg er det gitt en oppsummering for endringer i ytre påvirkning, vurdering av kunnskapsbehov samt en vurdering av indikatorverdier i forhold til referanseverdier og tiltaksgrenser. Vurderingen av dominerende trekk i utvikling og tilstand av miljøet som er gitt i kapittel 2, utgjør Overvåkingsgruppens bidrag til Faglig forums samlerapport om det faglige grunnlaget for revisjon og oppdatering av de helhetlige forvaltningsplanene for norske havområder.Status for miljøet i norske havområder - Rapport fra Overvåkingsgruppen 2023publishedVersio

Alexeeva, M., Moen, M.N., Grøsvik, K. et al (2018) Excision of uracil from DNA by hSMUG1 includes strand incision and processing.

Uracil arises in DNA by hydrolytic deamination of cytosine (C) and by erroneous incorporation of deoxyuridine monophosphate opposite adenine, where the former event is devastating by generation of C → thymine transitions. The base excision repair (BER) pathway replaces uracil by the correct base. In human cells two uracil-DNA glycosylases (UDGs) initiate BER by excising uracil from DNA; one is hSMUG1 (human single-strand-selective mono-functional UDG). We report that repair initiation by hSMUG1 involves strand incision at the uracil site resulting in a 3′-α,β-unsaturated aldehyde designated uracil-DNA incision product (UIP), and a 5′-phosphate. UIP is removed from the 3′-end by human apurinic/apyrimidinic (AP) endonuclease 1 preparing for single-nucleotide insertion. hSMUG1 also incises DNA or processes UIP to a 3′-phosphate designated uracil-DNA processing product (UPP). UIP and UPP were indirectly identified and quantified by polyacrylamide gel electrophoresis and chemically characterised by matrix-assisted laser desorption/ionisation time-of-flight mass-spectrometric analysis of DNA from enzyme reactions using 18O- or 16O-water. The formation of UIP accords with an elimination (E2) reaction where deprotonation of C2′ occurs via the formation of a C1′ enolate intermediate. A three-phase kinetic model explains rapid uracil excision in phase 1, slow unspecific enzyme adsorption/desorption to DNA in phase 2 and enzyme-dependent AP site incision in phase 3.publishedVersio

The Hyperthermophilic Euryarchaeon Archaeoglobus fulgidus Repairs Uracil by Single-Nucleotide Replacement ▿

Hydrolytic deamination of cytosine to uracil in cellular DNA is a major source of C-to-T transition mutations if uracil is not repaired by the DNA base excision repair (BER) pathway. Since deamination increases rapidly with temperature, hyperthermophiles, in particular, are expected to succumb to such damage. There has been only one report of crenarchaeotic BER showing strong similarities to that in most eukaryotes and bacteria for hyperthermophilic Archaea. Here we report a different type of BER performed by extract prepared from cells of the euryarchaeon Archaeoglobus fulgidus. Although immunodepletion showed that the monofunctional family 4 type of uracil-DNA glycosylase (UDG) is the principal and probably only UDG in this organism, a β-elimination mechanism rather than a hydrolytic mechanism is employed for incision of the abasic site following uracil removal. The resulting 3′ remnant is removed by efficient 3′-phosphodiesterase activity followed by single-nucleotide insertion and ligation. The finding that repair product formation is stimulated similarly by ATP and ADP in vitro raises the question of whether ADP is more important in vivo because of its higher heat stability

The escherichia coli alkA gene is activated to alleviate mutagenesis by an oxidized deoxynucleoside

The cellular methyl donor S-adenosylmethionine (SAM) and other endo/exogenous agents methylate DNA bases non-enzymatically into products interfering with replication and transcription. An important product is 3-methyladenine (m3A), which in Escherichia coli is removed by m3A-DNA glycosylase I (Tag) and II (AlkA). The tag gene is constitutively expressed, while alkA is induced by sub-lethal concentrations of methylating agents. We previously found that AlkA exhibits activity for the reactive oxygen-induced thymine (T) lesion 5-formyluracil (fU) in vitro. Here, we provide evidence for AlkA involvement in the repair of oxidized bases by showing that the adenine (A) ⋅ T → guanine (G) ⋅ cytosine (C) mutation rate increased 10-fold in E. coli wild-type and alkA– cells exposed to 0.1 mM 5-formyl-2′-deoxyuridine (fdU) compared to a wild-type specific reduction of the mutation rate at 0.2 mM fdU, which correlated with alkA gene induction. G⋅C → A⋅T alleviation occurred without alkA induction (at 0.1 mM fdU), correlating with a much higher AlkA efficiency for fU opposite to G than for that to A. The common keto form of fU is the AlkA substrate. Mispairing with G by ionized fU is favored by its exclusion from the AlkA active site

Forurensning i de norske havområdene - Barentshavet, Norskehavet og Nordsjøen - Rapport fra Overvåkingsgruppen 2021

Denne rapporten sammenstiller kunnskap om forurensningstilstanden i forvaltningsplanområdene Barentshavet, Norskehavet og Nordsjøen/Skagerrak, med hovedvekt på miljøgifter og radioaktiv forurensning. Rapporten oppsummerer resultater fra overvåkning av Overvåkingsgruppens indikatorsett, som publiseres på miljostatus.no, det vil si 43 indikatorer for forurensning og fire indikatorer for potensielt forurensende menneskelig aktivitet i havområdene. Rapporten inneholder også annen relevant kunnskap. Det er også gjort en evaluering av indikatorsettet og de ulike indikatorenes egnethet til å vurdere tilstand, utvikling og effekter på mattrygghet og miljøkvalitet

Structural basis for enzymatic excision of N(1)-methyladenine and N(3)-methylcytosine from DNA

N(1)-methyladenine (m(1)A) and N(3)-methylcytosine (m(3)C) are major toxic and mutagenic lesions induced by alkylation in single-stranded DNA. In bacteria and mammals, m(1)A and m(3)C were recently shown to be repaired by AlkB-mediated oxidative demethylation, a direct DNA damage reversal mechanism. No AlkB gene homologues have been identified in Archaea. We report that m(1)A and m(3)C are repaired by the AfAlkA base excision repair glycosylase of Archaeoglobus fulgidus, suggesting a different repair mechanism for these lesions in the third domain of life. In addition, AfAlkA was found to effect a robust excision of 1,N(6)-ethenoadenine. We present a high-resolution crystal structure of AfAlkA, which, together with the characterization of several site-directed mutants, forms a molecular rationalization for the newly discovered base excision activity