Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2003
Authors
Erlend Ystrøm Haartveit Dag FjeldAbstract
No abstract has been registered
Authors
Arne Sandnes Toril Drabløs EldhusetAbstract
No abstract has been registered
Authors
Arne Sandnes Toril Drabløs EldhusetAbstract
With small seedlings and dilute nutrient solutions, the use of glass beads as growth medium alters pH, conductivity and elemental composition of the solution to an extent that may affect the glass beads\" suitability as growth medium in plant cultivation experiments.
Authors
John DeromeAbstract
No abstract has been registered
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Bjørn ØklandAbstract
No abstract has been registered
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Knut Rydgren Rune H. Økland Tonje ØklandAbstract
No abstract has been registered
Authors
Lars Sandved Dalen J. Watkinson A.A. Sioson V. Singal D. Kumar N. Ramakrishnan L.S. Heath Carl Gunnar Fossdal R. GreneAbstract
Trees cover over one-third of the world\"s land area and carry out about two-thirds of global photosynthesis. Coniferous forests cover 1.2 billion hectares of Alaska, Canada, Scandinavia, and Russia, and comprise one-fourth of the world\"s boreal and temperate forests. More than 50% of Scandinavia\"s land area consists of forests, mostly coniferous. Information about the molecular responses in trees to biotic and abiotic factors is therefore of great importance - both scientifically and practically.Transcript regulation in response to drought stress was investigated for Norway spruce (Picea abies) with microarrays including 1,700 cDNAs from 5 EST libraries from Pinus taeda and analyzed using the Expresso Microarray Management System.In order to verify the level of drought stress, we measured the physiological status of the plants. After four days of drought, chlorophyll fluorescence was reduced by 6% and after eight days by over 40 %, compared to the control. Hybridizations of spruce RNA to microarray slides was used to probe for changes in transcripts from two to eight days after watering stopped.Monitoring of transcript levels was accomplished by hybridizing spruce cDNA to the 1700 element microarrays. After two days of drought, circa 2 % of the transcripts in Norway spruce were significantly upregulated and 7 % were downregulated. At the end of the experiment after eight days of drought needle chlorophyll fluorescence was reduced by 40 % compared to the control, and 6 % of the transcripts were upregulated and 12 % of the transcripts were downregulated. Results from inductive logic programming are also presented.
Abstract
Farmers in northern Norway have experienced severe winter damage on grassland rather frequently, especially on flat areas and peat soils in regions with an unstable winter climate around zero degrees Celsius. Traditional drainage with drainpipes is normally not sufficient to prevent such damage in these areas. During the past two decades the use of open ditches and surface grading has become the main method of reclaiming and draining peat land. A new heuristic stochastic dynamic analysis method for problems like this, combining simulation and optimisation, is used to explore the profitability of surface grading of peat soils. This analysis indicates that the year in which a ley should be reseeded depends on stage in the growth curve when eventually the winter damage happens as well as on the severity of the damage. Given the present acreage subsidy payment, surface grading is normally profitable from a farmers point of view.
Authors
J. Brian Hardaker Gudbrand LienAbstract
A method of stochastic dominance analysis with respect to a function (SDRF) is described and illustrated. The method, called stochastic efficiency with respect to a function (SERF), partitions a set of risky alternatives in terms of certainty equivalents for a specified range of attitudes to risk. It can be applied for any utility function with risk attitudes defined by corresponding ranges of absolute, relative or partial risk aversion coefficients. SERF involves comparing each alternative with all the other alternatives simultaneously, not pairwise as with conventional SDRF. Hence it yields a subset of the efficient set found by SDRF. Moreover, the method is readily implemented in a simple spreadsheet with no special software needed.
Authors
M. Persson J. Lönnquist Bo Långström Halvor Solheim M. Kyto Anna-Karin Borg-KarlsonAbstract
No abstract has been registered