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.
2010
Forfattere
Espen Govasmark Anicke Brandt-Kjelsen Brit SalbuSammendrag
The diet is the major source of Se to man and intake of this essential element depends on the Se concentration in food and the amount of food consumed. Since the levels of Se in agricultural products in Northern Europe are generally low, Se deficiency to man and animal is a significant problem in many countries. Agronomic Se-fortification of plant products is one strategy to increase the human Se intake. Estimation of diets for Se adequacy requires information not only on the total Se, but also on Se-species, accessibility, bioavailability of Se-species in food. Therefore, the present work focuses on the distribution and speciation of Se in Se enriched wheat grains and its accessibility estimated from extraction with human gastro intestinal juices (HGIJ) and Se bioavailability to chicken determined as the bioconcentration factor (BCF); breast muscle/feed intake Se concentration. In the present work, wheat grains were Se-selenate enriched by soil or foliar fertilisation in a greenhouse experiment at seeding or tillering with or without a spilt nitrogen fertilisation strategy to investigate (1) if the Se-species distribution in grains were affected. Then, field grown Se-enriched wheat grains were used (2) to estimate the total and Se-species distribution in the flour and bran and its accessibility, as chicken feed (3) to estimate the Se BCF and as ingredience in bread (4) to investigate Se-transformation and estimate the Se-accessibility from wheat flour to bakery product. Se-speciation was performed using an anion exchange-HPLC-ICP/MS system with 25-250 mM NH4Ac, pH 5.1 gradient elution. The Se fertilisation with selenate at tillering is more efficient than at seedling and additional N-fertilisation at tillering increases the Se-uptake and re-translocation from leaf to grains. Selenomethionine (SeMet) was the dominant Se-species in the grains, but an unidentified Se-species (Se-cysteine?) is to be investigated. Selenate fertilization closest to grain filing period had a higher proportion of selenate and a lower ratio between SeMet and the unidentified Se species, than Se fertilization at seeding. N fertilisation did not affect the Se-species distribution. The Se concentration in field grown wheat grains was 1.2 mg Se kg-1, while the concentrations in flour and bran were 1.1 and 1.6 mg Se kg-1, respectively. The main Se-species in the bran and flour was SeMet. The flour and bran HGIJ extraction showed that Se in the flour was more accessible than in the bran, but since the bran has a higher Se concentration, the amount of Se accessible was about the same for flour and bran. The BCF in chicken breast muscle increased from 0.6 to 1.9 by changing from selenite to Se-enriched whole wheat as dietary Se source, thus Se-enriched wheat was more efficient in increasing the chicken meat Se concentration. The bread making procedure did not influence the Se-species distribution when compared to unprocessed flour. The Se-accessibility was higher in the bread kernel compared to the crust, most probably due to high temperature during roasting. High content of bran in the bread decreased the Se-accessibility Thus, agronomic Se-fortification of Se to wheat is a good strategy to increase the human dietary intake and potentially also the human population Se status.
Forfattere
Espen Govasmark Anicke Brandt-Kjelsen Brit SalbuSammendrag
The diet is the major source of Se to man and intake of this essential element depends on the Se concentration in food and the amount of food consumed. Since the levels of Se in agricultural products in Northern Europe are generally low, Se deficiency to man and animal is a significant problem in many countries. Agronomic Se-fortification of plant products is one strategy to increase the human Se intake. Estimation of diets for Se adequacy requires information not only on the total Se, but also on Se-species, accessibility, bioavailability of Se-species in food. Therefore, the present work focuses on the distribution and speciation of Se in Se enriched wheat grains and its accessibility estimated from extraction with human gastro intestinal juices (HGIJ) and Se bioavailability to chicken determined as the bioconcentration factor (BCF); breast muscle/feed intake Se concentration. In the present work, wheat grains were Se-selenate enriched by soil or foliar fertilisation in a greenhouse experiment at seeding or tillering with or without a spilt nitrogen fertilisation strategy to investigate (1) if the Se-species distribution in grains were affected. Then, field grown Se-enriched wheat grains were used (2) to estimate the total and Se-species distribution in the flour and bran and its accessibility, as chicken feed (3) to estimate the Se BCF and as ingredience in bread (4) to investigate Se-transformation and estimate the Se-accessibility from wheat flour to bakery product. Se-speciation was performed using an anion exchange-HPLC-ICP/MS system with 25-250 mM NH4Ac, pH 5.1 gradient elution. The Se fertilisation with selenate at tillering is more efficient than at seedling and additional N-fertilisation at tillering increases the Se-uptake and re-translocation from leaf to grains. Selenomethionine (SeMet) was the dominant Se-species in the grains, but an unidentified Se-species (Se-cysteine?) is to be investigated. Selenate fertilization closest to grain filing period had a higher proportion of selenate and a lower ratio between SeMet and the unidentified Se species, than Se fertilization at seeding. N fertilisation did not affect the Se-species distribution. The Se concentration in field grown wheat grains was 1.2 mg Se kg-1, while the concentrations in flour and bran were 1.1 and 1.6 mg Se kg-1, respectively. The main Se-species in the bran and flour was SeMet. The flour and bran HGIJ extraction showed that Se in the flour was more accessible than in the bran, but since the bran has a higher Se concentration, the amount of Se accessible was about the same for flour and bran. The BCF in chicken breast muscle increased from 0.6 to 1.9 by changing from selenite to Se-enriched whole wheat as dietary Se source, thus Se-enriched wheat was more efficient in increasing the chicken meat Se concentration. The bread making procedure did not influence the Se-species distribution when compared to unprocessed flour. The Se-accessibility was higher in the bread kernel compared to the crust, most probably due to high temperature during roasting. High content of bran in the bread decreased the Se-accessibility Thus, agronomic Se-fortification of Se to wheat is a good strategy to increase the human dietary intake and potentially also the human population Se status.
Sammendrag
Seterdrifta former naturen Fra "Seterlandskapet - der skog og fjell møtes". Veilederen er utgitt av SABIMA (Samarbeidsrådet for biologisk mangfold) i samarbeid med Nordisk Kulturlandskap-Norge og Bioforsk, og med økonomisk støtte fra Finsefondet. Teksten er skrevet av Hanne Sickel og Ellen Svalheim, begge fra Nordisk Kulturlandskapsforbund-Norge og forskere i Bioforsk. Veilederen gir litt av den historiske bakgrunnen og en gjennomgang av generelle praktiske tips og råd for hvordan slik restaurering og skjøtsel kan foregå.
Forfattere
Erling Stubhaug Åsmund Erøy Sigbjørn Leidal Siri Abrahamsen Tor Anton Guren Ninni ChristiansenSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Side effects related to liming have been studied in four dimictic lakes (553-642 ma.s.l.; 59 degrees 57'N) in Finnemarka, a forested area in Southern Norway with poor catchment buffer capacity. Data series from lake profiles have been sampled two decades apart; 10 years prior to liming and after 10 years of liming. Water samples were collected during spring after ice breakup and during summer after the development of thermal stratification. Before liming, there were very low concentrations of bicarbonate (HCO3-; or alkalinity) in the lakes. After 10 years of liming, up to 90% of the ions in hypolimnion originate from lime products. Hence, liming strengthened the chemical stratification and increased the vertical stability. Differences in chemocline developments between lakes were explained by differences in physical properties, i.e. their depth/surface area ratio. The chemocline developments lead to increased concentrations of organic matter in the hypolimnion with a subsequent reduction in oxygen concentrations. Lime additions during late spring, as an alternative to early autumn, lead to pronounced anoxic conditions in the hypolimnion.
Forfattere
Lars Nesheim Uffe JørgensenSammendrag
In Denmark, Finland and Sweden cultivation of energy crops has been commercial for several years. In Norway there is hardly any commercial growing of agricultural crops for energy purposes. Cereal straw is to some extent used as a solid biofuel. The objective of this chapter is to give a review of the current production of different energy crops in the Nordic countries, and to present some ideas on what may be the future biofuels in these countries. The most important bioenergy crop concerning the area of cultivation is wheat for bioethanol on about 27 000 hectares in Sweden. That constitutes about 7 % of total area of wheat. There is now one factory for bioethanol production in Sweden, and two or three more plants are planned. In Finland reed canary grass is now grown on 20 000 hectares, and the energy crop may be used in about 12 power plants in bales or as fuel-mix. This crop is well suited for Finland and Northern Sweden, where the winters are cold. There is also commercial growing of reed canary grass for biofuel in Sweden, but the area is much lower than in Finland. The Ministry of Agriculture and Forestry in Finland has set a target to increase the area of energy crops to 100 000 hectares before 2016. In Sweden willow (Salix) is grown on about 13 500 hectares of agricultural land. The area is not increasing any longer, mostly due to reduced subsidies. In Denmark there is a considerable production of oil seed rape for biodiesel, but there are no adequate statistics on the oil use. In addition to the mentioned crops there is some commercial cultivation of other bioenergy crops, such as hemp, miscanthus and crops for biogas production. Phasing out fossil fuel use in the Nordic countries is a clear political focus even though the path to the goal is not yet defined in all countries. However, it seems clear that biomass will play a very significant role at least in the medium term within the next fifty years. This will be for heat and power, but also the demands for increased biofuel use in the transport sector will increase the need for biomass dramatically. First choice should be sustainable utilization of biomass residues. Growing dedicated energy crops is an option for delivering increased amounts of biomass.
Sammendrag
In terrestrial ecotoxicology there is a serious lack of data for potential hazards posed by engineered nanoparticles (ENPs). This is partly due to complex interactions between ENPs and the soil matrix, but also to the lack of suitable toxicological end points in organisms that are exposed to ENPs in a relevant manner. Earthworms are key organisms in terrestrial ecosystems, but so far only physiological end points of low sensitivity have been used in ecotoxicity studies with ENPs. We exposed the earthworm Lumbricus terrestris to silver nanoparticles and measured their impact on apoptosis in different tissues. Increased apoptotic activity was detected in a range of tissues both at acute and sublethal concentrations (down to 4 mg/kg soil). Comparing exposure in water and soil showed reduced bioavailability in soil reflected in the apoptotic response. Apoptosis appears to be a sensitive end point and potentially a powerful tool for quantifying environmental hazards of ENPs.
Sammendrag
The aim of this study is to use airborne laser scanning (ALS) data to simulate synthetic aperture radar interferometry (InSAR) elevation data [digital elevation model (DEM)] from the spatial distribution of scatterers. A Shuttle Radar Topography Mission X-band DEM data set and an ALS data set from a spruce-dominated forest area are used. A 3-D grid of voxels is made from the spatial distribution of ALS first echoes. The slant angle penetration rate of the SAR microwaves (P-SAR) is simulated to be a function of the vertical ALS penetration rate (P-ALS), i.e., P-SAR = P-ALS(4). The InSAR DEM and heights above the ground are fairly well reproduced by the simulator. A total least squares regression model between the simulated and measured InSAR DEMs has an R-2 value of 0.99 and a slope of 1 : 1. By subtracting the ALS-based terrain heights (digital terrain model), we obtained InSAR heights, which were reproduced with an R-2 value of 0.78, a slope of 0.96, and a root-mean-square error of 2.3 m. With the simulator, it was demonstrated how a disturbance event would affect the InSAR height. Unfortunately, the relationship was curvilinear and concave, which means that the method is not very sensitive to weak disturbances. This might be partly overcome by using a more vertical incidence angle of the SAR microwaves. The simulator might be used for validation or ground truthing of the InSAR data, as well as gaining understanding of how vegetation changes affect the InSAR data.
Sammendrag
Det er ikke registrert sammendrag