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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.

2012

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Sammendrag

The selective serotonin reuptake inhibitors citalopram, sertraline, paroxetine, fluvoxamine and fluoxetine have been investigated in 10 l anaerobic lab-scale digesters with continuous stirring and mesophilic conditions at 37 °C to investigate whether they would be reduced or accumulated in sewage sludge depending on whether the bacteria present were able to use the SSRIs as a carbon source or not. The total SSRI concentration had a significant reduction in concentration during the anaerobic treatment process from theoretically 0.58 mg/l to 0.21 mg/l after 17 days. However, large differences in the reduction of the different compounds were found. Paroxetine and citalopram were found to be almost completely reduced at day 24 with reductions of 85% (citalopram) and 98% (paroxetine). Reductions of 32% (fluoxetine), 53% (fluvoxamine) and 38% (sertraline) indicate that these three compounds have a higher potential for accumulation. None metabolites of these compounds were found in the samples.

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Sammendrag

The Norwegian Direct Payment Register (PTR) is a database covering all units that claim direct payments on the basis of eligible animals and acreage. As almost all farms apply for payments and as almost all animal and crop production activities are eligible for various kinds of direct payments, the database represents an unique tool to analyse farm structural change. This paper contains a detailed description of the database and presents some possible venues to conduct such research.

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Sammendrag

This study examines the comparative performance of the call and put implied volatility (IV) of at-the-money European-style SPX Index Options on the S&P 500 Price Index as a precursor to the ex-post realized volatility. The results confirm that implied volatility contains valuable information regarding the ex-post realized volatility during the last decade for the S&P 500 market. The empirical findings also indicate that the put implied volatility has a higher forecast performance. Furthermore, from the wavelet estimations it has been concluded that the long-run variation of the implied volatility is consistent and unbiased in explaining the long-run variations of the ex-post realized volatility. Wavelet estimations further reveal that in the long-run put and call implied volatility contain comparable information regarding the realized volatility of the market. However, in the short-run put implied volatility dynamics have better predictive ability.