Sedimentundersøkelser i forbindelse med tiltaksplan for forurensede sedimenter i Arendal: Fase 2

Årsliste 2005I Norge utarbeides det nå tiltaksplaner mot forurensede sedimenter i havner og fjordområdet, deriblant Arendalsområdet. Det er begrunnet i at tidligere undersøkelser av sedimenter, fisk og skalldyr har vist høye konsentrasjoner av miljøgifter i området ved Arendal. Myndighetene har derfor utstedt kostholdsråd for området. I forbindelse med tiltaksplanene for Arendal er sedimentene prøvetatt på nytt og det er gjennomført en risikovurdering i hht SFTs veileder. Risikovurderingene er knyttet til fare for spredning, risiko for økosystemet og human risiko (i hovedsak ved inntak av fisk og skalldyr fra området). Generelt var det relativt lave konsentrasjoner av tungmetallene kadmium, krom, kobber og bly i hele tiltaksområdet. Det var høye verdier av kvikksølv i området rundt Pollen og Kittelsbukt. Det var generelt høye verdier av TBT og PAH på alle stasjonene i hele tiltaksområdet, mens det var høye verdier av PCB i området rundt Pollen og Kittelsbukt. På alle stasjoner var det en overskridelse i varierende grad av akseptabel risiko. Det eksisterer imidlertid ikke grenseverdier som kan bedømme overskridelsene nærmere. Risikoen som de forurensede sedimentene representerer, er i hovedsak knyttes til innholdet av PCB, til dels også PAH-forbindelsen benzo(a)pyren. Særlig gjelder det området rundt Pollen og Kittelsbukt hvor resultatene kan tyde på mulige aktive kilder. På grunnlag av risikovurderingene er tiltaksområdet delt inn i delområder. Ut fra risikovurderingene og miljømål er det foreslått at eventuelle tiltak konsentreres til et bynært område på ca. 2 km2. Det bør utvikles et program som overvåker forurensningsutviklingen i området. Det bør dekke både områder hvor fysiske tiltak gjennomføres og områder hvor endringen drives av naturlig forbedring.Fylkesmannen i Aust-Agder

Undersøkelser for å styrke modeller knyttet til beslutningsstøtte for tiltak mot forurensede sedimenter i Grenlandsfjordene

Årsliste 2009I forbindelse med problemstillingene om sedimenttiltak i Grenlandsfjordene, er undersøkelser utført for å styrke beslutningsgrunnlaget for eventuelle tiltak mot dioksinforurensede sedimenter i fjordområdet. Dette arbeidet har bestått i en avansert kalibrering av den såkalte SedFlex-modellen for å styrke usikkerhetsestimatene i modellsimuleringene. Betydningen av skipsoppvirvling ved Herøya for dioksinutviklingen i Frierfjorden er modellert. Videre er tykkelsen på det aktive, bioturberte overflatelaget på 39 stasjoner i Grenlandsfjordene bestemt ved hjelp av SPI-sedimentkameraet. Tre stasjoner for ”overvåket naturlig forbedring” er blitt opprettet hvor den feltmessige variansen er beskrevet og utsagnskraften i et overvåkingsprogram beregnet. Transport av dioksiner fra Frierfjorden til fjordområdet utenfor er beregnet både gjennom direkte målinger ved bruk av passive prøvetakere og ved simuleringer i SedFlex-modellen.Norsk Hydr

Market conditions, trader types and price–volume relation in energy futures markets

We investigate the asymmetric relations between trading volume and price changes, and trading volume and price volatility of energy futures contracts across maturities and under different market conditions. Using a relatively long sample of daily observations, we examine whether the impact of trading volume on returns and volatility of futures contracts can be time-varying and dependent on the market condition. We differentiate the market condition based on the slope of the forward curve into backwardation and contango. The results indicate that trading volume and returns are positively related when the market is in backwardation and negatively related when the market is in contango. In addition, the positive relation between changes in trading volume and volatility of futures contracts seem to be stronger when the market is in backwardation than when it is in contango. Finally, the results indicate that, to a certain extent, trade participation and trading activities of agents in energy futures markets can be explained by the slope of the forward curve which reflects the market condition and sentiment

A spectroscopy approach to the study of virus infection in the endophytic fungus Epichloë festucae

<p>Abstract</p> <p>Background</p> <p>In this work we propose a rapid method based on visible and near-infrared (Vis-NIR) spectroscopy to determine the occurrence of double-stranded RNA (dsRNA) viruses in <it>Epichloë festucae </it>strains isolated from <it>Festuca rubra </it>plants. In addition, we examined the incidence of infections by <it>E. festucae </it>in populations of <it>F. rubra </it>collected in natural grasslands of Western Spain.</p> <p>Methods</p> <p>Vis-NIR spectra (400-2498 nm) from 124 virus-infected and virus-free <it>E. festucae </it>isolates were recorded directly from ground and freeze-dried mycelium. To estimate how well the spectra for uninfected and infected fungal samples could be differentiated, we used partial least-squares discriminant analysis (PLS1-DA) and several data pre-treatments to develop calibration models.</p> <p>Results</p> <p>Applying the best regression model, obtained with two sampling years and using standard normal variate (SNV) combined with first derivative transformation to a new validating data set (42 samples), we obtained a correct classification for 75% of the uninfected isolates and up to 86% of the infected isolates.</p> <p>Conclusions</p> <p>The results obtained suggest that Vis-NIR spectroscopy is a promising technology for detection of viral infections in fungal samples when an alternative faster approach is desirable. It provides a tool adequately exact and more time- and cost-saving than the conventional reference analysis.</p

Can information affect sensory perceptions? Evidence from a survey on Italian organic food consumers

This paper aims to investigate the influence of information on consumers’ preferences and sensory perceptions of organic food using a sample of 301 Italian organic food consumers. Consumers stated their preferences for “core organic” attributes, labels and information on food products and performed blind and informed tests on strawberry yoghurts and cookies. Data were analysed using descriptive analysis, Mann-Whitney U tests and Wilcoxon signed-rank test. Results revealed that consumers appreciate “core organic” attributes, like artisanal production and variability of sensory attributes. Comparing blind and informed tests, results showed that information affects the overall liking of products and consumers’ perception of product-specific sensory attributes. However, the influence of information on sensory perceptions depends on the product category, sensory attributes and the type of information provided

Synthetic Mimic of Antimicrobial Peptide with Nonmembrane-Disrupting Antibacterial Properties

Proteolysis in dairy lactic acid bacteria has been studied in great detail by genetic, biochemical and ultrastructural methods. From these studies the picture emerges that the proteolytic systems of lactococci and lactobacilli are remarkably similar in their components and mode of action. The proteolytic system consists of an extracellularly located serine-proteinase, transport systems specific for di-tripeptides and oligopeptides (> 3 residues), and a multitude of intracellular peptidases. This review describes the properties and regulation of individual components as well as studies that have led to identification of their cellular localization. Targeted mutational techniques developed in recent years have made it possible to investigate the role of individual and combinations of enzymes in vivo. Based on these results as well as in vitro studies of the enzymes and transporters, a model for the proteolytic pathway is proposed. The main features are: (i) proteinases have a broad specificity and are capable of releasing a large number of different oligopeptides, of which a large fraction falls in the range of 4 to 8 amino acid residues; (ii) oligopeptide transport is the main route for nitrogen entry into the cell; (iii) all peptidases are located intracellularly and concerted action of peptidases is required for complete degradation of accumulated peptides.

Measurement of Single Soybean Seed Attributes by Near-Infrared Technologies. A Comparative Study

Four near-infrared spectrophotometers, and their associated spectral collection methods, were tested and compared for measuring three soybean single-seed attributes: weight (g), protein (%), and oil (%). Using partial least-squares (PLS) and four preprocessing methods, the attribute that was significantly most easily predicted was seed weight (RPD > 3 on average) and protein the least. The performance of all instruments differed from each other. Performances for oil and protein predictions were correlated with the instrument sampling system, with the best predictions using spectra taken from more than one seed angle. This was facilitated by the seed spinning or tumbling during spectral collection as opposed to static sampling methods. From the preprocessing methods utilized, no single one gave the best overall performances but weight measurements were often more successful with raw spectra, whereas protein and oil predictions were often enhanced by SNV and SNV + detrending.Posted with permission from Journal of Agricultural and Food Chemistry 60 (2012): 8314–8322, doi:10.1021/jf3012807. Copyright 2012 American Chemical Society.</p