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.
2009
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
The molecular composition of plant residues is suspected to largely govern the fate of their constitutive carbon (C) in soils. Labile compounds, such as metabolic carbohydrates, are affected differently from recalcitrant and structural compounds by soil-C stabilisation mechanisms. Producing 13C-enriched plant residues with specifically labeled fractions would help us to investigate the fate in soils of the constitutive C of these compounds. The objective of the present research was to test 13C pulse chase labeling as a method for specifically enriching the metabolic carbohydrate components of plant residues, i.e. soluble sugars and starch. Bean plants were exposed to a 13CO2-enriched atmosphere for 0.5, 1, 2, 3 and 21 h. The major soluble sugars were then determined on watersoluble extracts, and starch on HCl-hydrolysable extracts. The results show a quick differential labeling between water-soluble and water-insoluble compounds. For both groups, 13C-labeling increased linearly with time. The difference in δ13C signature between water-soluble and insoluble fractions was 7% after 0.5 h and 70% after 21 h. However, this clear isotopic contrast masked a substantial labeling variability within each fraction. By contrast, metabolic carbohydrates on the one hand (i.e. soluble sugarsRstarch) and other fractions (essentially cell wall components) on the other hand displayed quite homogeneous signatures within fractions, and a significant difference in labeling between fractions: δ13C=414±3.7% and 56±5.5%, respectively. Thus, the technique generates labeled plant residues displaying contrasting 13C-isotopic signatures between metabolic carbohydrates and other compounds, with homogenous signatures within each group. Metabolic carbohydrates being labile compounds, our findings suggest that the technique is particularly appropriate for investigating the effect of compound lability on the long-term storage of their constitutive C in soils.
Forfattere
Tove Maria Østensvik Kaj Bo Veiersted Petter Dahl NilsenSammendrag
Aim The purpose of this paper was to describe and evaluate different aspects of muscle activity patterns associated with musculoskeletal discomfort/pain. Method Surface electromyography (sEMG) of the right upper trapezius and the right extensor digitorum muscles was conducted continuously during one working day in 19 male forest machine operators driving harvesters, 20 driving forwarders and 20 researchers at the Forest Research Institute. Perceived discomfort/pain in the right side of the neck and the right forearm was rated morning, noon and afternoon with Borg’s CR-10 scale. Static, median and peak levels of muscle activity were analyzed and the number and total duration of EMG gaps (muscular rest) were calculated. Sustained low-level muscle activity (SULMA) was defined as continuous muscle activity above 0.5% of the maximal EMG activity quantified into 10 periods of predetermined duration intervals from 1.6 to 5 s up to above 20 min. The number of SULMA periods is presented within each interval and as cumulative periods above the already determined levels. The operators handled control levers seated in a fixed position while the researchers performed mainly PC work and other varied tasks. Results A positive correlation was found between discomfort/pain in the right upper trapezius muscle region in the afternoon and cumulative SULMA periods above 10 min duration, and a negative correlation to cumulative SULMA periods also including the short durations. No specified patterns were found for discomfort/pain in the right extensor digitorum or for the other EMG measurements. All EMG measurements distinguished to some extent between the occupational groups, especially between machine operators driving harvesters and researchers. Conclusions Number of SULMA periods longer than 10 min per hour was positively correlated, and predominantly short periods were negatively correlated, to complaints in the neck region. This seems promising in order to find duration limits for sustained low-level muscle activity as a risk factor for musculoskeletal disorders.
Forfattere
Lars NesheimSammendrag
The challenges of grassland management are not quite the same in different European countries. I have always been of the opinion that there is a lot to learn by visiting other countries and by participating in international conferences. I have on two occasions stayed a year at research institutes in Europe. My first stay was in Switzerland, where I had the opportunity to work on a specific subject; biological nitrogen fixation in white clover. On my second stay, at North Wyke in 1997-98, I had a much broader approach. I wished to work with several of the research groups at the Station in order to learn about research methods and results. All members of the staff had a positive attitude to me as a visiting scientist, and they were helpful and did not seem to be tired of all my questions on research issues, or on social and political conditions in Great Britain.
Forfattere
N. Abrantes Randi Bolli Gro Hege Ludvigsen Olav Lode F. Goncalves Ole Martin Eklo Lillian Øygarden J.J. KeizerSammendrag
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Forfattere
Oleif ElenSammendrag
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Forfattere
A. Lehtinen B. Andersson Vinh Hong Le Ragnhild Nærstad M. Rastas E. Ketoja A. O. Hannukkala Arne Hermansen B. Nielsen J. G. Hansen J. YuenSammendrag
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Forfattere
Håkon BorchSammendrag
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Forfattere
Håkon BorchSammendrag
AgriCat-P er en nyutviklet modell for beregning av fosfortap fra jordbruk. Modellen er særlig egnet til å teste forventet effekt av endret landbruksdrift og gjennomføring av tiltak. AgriCat–P er brukt i forbindelse med EUs vanndirektiv i vannområdene Morsa, Lysakerelva, Haldenvassdraget, og Bunnefjorden, samt i Halden og Fredrikstad kommune.
Forfattere
Lampros LamprinakisSammendrag
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