Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2008
Sammendrag
Studies regarding the environmental impact of engineered nanoparticles (ENPs) are hampered by the lack of tools to localize and quantify ENPs in water, sediments, soils, and organisms. Neutron activation of mineral ENPs offers the possibility of labeling ENPs in a way that avoids surface modification and permits both localization and quantification within a matrix or an organism. Time-course experiments in vivo also may be conducted with small organisms to study metabolism and exposure, two aspects currently lacking in ecotoxicological knowledge about ENPs. The present report explains some of the prerequisites and advantages of neutron activation as a tool for studying ENPs in environmental samples and ecologically relevant organisms, and it demonstrates the suitability of neutron activation for Ag, Co/Co3O4, and CeO2 nanoparticles. In a preliminary experiment with the earthworm Eisenia fetida, the dietary uptake and excretion of a Co nanopowder (average particle size, 4 nm; surface area, 59 m(2)/g) were studied. Cobalt ENPs were taken up to a high extent during 7 d of exposure (concentration ratios of 0.16-0.20 relative to the ENP concentration in horse manure) and were largely retained within the worms for a period of eight weeks, with less than 20% of absorbed ENPs being excreted. Following dissection of the worms, Co-60 was detected in spermatogenic cells, cocoons, and blood using scintillation counting and autoradiography. The experimental opportunities that neutron activation of ENPs offer are discussed.
Sammendrag
The European pine sawfly Neodiprion sertifer is a widely distributed defoliator of pines that can cause substantial growth losses over extensive areas. It attacks most species of twoneedle pines in its distribution area, and have occasional short-lived outbreaks that may cover up to 200.000 ha. In Norway we have had outbreak populations in the eastern part of the country since 2004, and in an ongoing research project we are evaluating aerial application of the Neodiprion sertifer nuclear polyhedrosis virus (NsNPV) to control Neodiprion sertifer....
Forfattere
Tore Krogstad Anne Falk Øgaard Annbjørg Øverli KristoffersenSammendrag
Det er ikke registrert sammendrag
Forfattere
Tore Krogstad Anne Falk Øgaard Annbjørg Øverli KristoffersenSammendrag
The P norm for meadow, pasture, oil seeds and cereal crops is reduced by 25-30% to a balance level for input and output of P. A new correction system has a stronger reduction in P fertilization at high to very high soil P-AL levels than the old correction system, resulting in a faster decrease in the P-AL fraction over time when P-AL is high. No P fertilization is recommended at P-AL levels higher than 14. The combined effect of new P norms and correction system is expected to have a very marked effect on the use of P fertilizer as the reduction in P recommendations is about 50% or more at common P-AL levels (P-AL 10-15) in the soil.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Anne Falk ØgaardSammendrag
Det er ikke registrert sammendrag
Sammendrag
Skjemmande, gråbrune nåler etter angrep av soppen Herpotrichia parasitica er funnen på edelgran i juletrefelt i Rogaland.
Forfattere
Reidun PommerescheSammendrag
De norske normene for innhold av svovel (S) til grovfôrplanter og husdyr ser ut til å være for høye. De er i alle fall ikke tilpasset situasjonen ved økologisk produksjon. Undersøkelser viser at til tross for lavt innhold av svovel i jord og fôr var det ingen positiv effekt av svovelgjødsling. Les mer i artikkelen...
Forfattere
Thomas Hartnik John Jensen Joop L.M. HermensSammendrag
Det er ikke registrert sammendrag
Sammendrag
Chemical methods to assess bioavailability in soil and sediment often use synthetic polymers that mimic uptake of organic compounds in organisms or microbial degradation. In this paper we have assessed a biomimetic extraction method using hydroxyl-beta-cyclodextrin (HP-beta-CD) to estimate uptake of the two insecticides alpha-cypermethrin (alpha-CYP) and chlorfen-vinphos (CFVP) in the earthworm Eisenia fetida. Additionally, a novel approach was developed to estimate the efficiency of biomimetic extractions. The study revealed that HP-beta-CD is a suitable surrogate for estimating the bioaccessibility of hydrophobic chemicals in soil. If one uses a 3.5 times higher amount of HP-beta-CD than soil, effective and reproducible extractions can be achieved within 48h. At these conditions, inclusion of dissolved chemicals by HP-beta-CD mimics uptake of a given compound into earthworms and takes into account sorption-related aspects that control biological uptake. The data indicate that, with increasing hydrophobicity, the affinity of organic chemicals to HP-beta-CD does not increase to the same degree as to soil organic matter. Therefore, a high surplus of HP-beta-CD is necessary to provide a sufficient extraction capacity in biomimetic extractions.