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.
2006
Forfattere
Liv Guri VelleSammendrag
Artikkel om kystlyngheiane og gjengroing. Artikkelen tek opp at over 80 % av det opphavlege kystlyngheiarealet har forsvunne, og at ein del av kulturarven vår gror att.
Forfattere
Tor Håkon Sivertsen Janis GailisSammendrag
A web-base system for administrating data from a network of agro meteorological stations is presented, especially the module containing the documentation of the instruments. The quality concept of meteorological data is presented. The system development practice is recently changing from a traditional in-house and vendor controlled system to the global software development in a highly distributed and heterogeneous environments. This can be highly challenging for system development practices related to specific domain activities like collection, control and correction of meteorological and biological data, since the number of involved actor-networks can become large and the interactions between actor-networks then tends to be complex. To utilize the meteorological and biological data in scientific models that has practical implications for the users, and to make the data accessible and representative in different contexts, a large set of actor-networks has to be considered. To illustrate the variety of interactions between actor-networks in the process of the development of a web-based system, the actor-network theory , ANT, (Law, 1992; Latour, 2005; Latour and Woolgar, 1986) is shortly introduced. The actor-network dealing with collection, administration, control, correction and presentation of values of both measured ( by sensors) and derived parameters, is described in a detailed manner. Also the role of the formal and informal specifications is discussed ( Frias et al., 2005) for the actor-networks involved in the process of development. A heterogeneous engineering approach is suggested for the further development of the web-based system, especially the control and correction of the meteorological and biological data. Some features of another system for documentation of instruments, called `Sensor Model Language" is didcussed and commented. We ask, if using ANT to describe the social patterns uncovered during the system development process, can this increase the usability and dynamical features for various actor-networks involved? References: Latour, B., & Woolgar, S.,(1986), Laboratory Life : The construction of scientific facts; Princeton; Princetn university Press. Fries, A. F., Lopez Pombo, C.G., Baum, G.A., Aguirre, N.M., & Maibaum, T.S.E., (2005), Reasoning about static and dynamic properties in alloy: A purely relational approach, ACM Transactions on software engineering and methology, Vol. 14., No 4, October 2005, p. 478-526 Law, J., (1992), Notes on the theory of the actor-network: Ordering, strategy, and heterogeneity, systemiv practice and action research,Springer Netherlands, ISSN: 1094-429x ( Paper) 1573-9295 ( online), D01: 10.1007/BF01059830, Issue: Volume 5, Number 4, August 1992, p. 379-393 Latour, B., (2005), Reassembling the social: An introduction to Actor-network theory; Oxford; Oxford University Press Sivertsen, T.H., 2005, Implementation of a General Documentation System for web-based administration and use of historical series of meteorological and biological data, Physics and Chemistry of the Earth Special Issue: Agrometeorology 2003, Vol 30/1-3 pp 217-222 Sivertsen, T.H., 2005, Discussing scientific methods and the quality of meteorological data, in `Use and Availability of Meteorological Information from Different Sources as Input in Agrometeorological Models", COST ACTIONS 718 `Meteorological Applications for Agriculture", Edited by G. Maracchi, A. Mestre, L. Toulios and B. Gozzini. Sivertsen, T.H, 2005, ", Reflections on the Theme of Classifying, Documenting and Exchanging Meteorological Data", Atmospheric Science Letters, Vol.6 , Issue 3, p 171-175, John Wiley & Son
Forfattere
Tor Håkon SivertsenSammendrag
Elements of the physical background of the phenomenon of internal gravity waves in the atmosphere are discussed , and the classical two-dimensional description of stationary waves is presented. Then the classical linearized system of equations is presented and discussed. The equation of wave energy of stationary waves of Eliassen & Palm (1961) is presented, as well as their statement of the conservation of the vertical flux of wave energy in a large class of systems. The special situation of a vertical layered atmospheric system with a discontinuity ( in the vertical direction) in the temperature of the air, the density of the air or the main stream) is considered. It is shown that the boundary conditions used by Eliassen & Palm (1961) sometimes violate their statement of conservation of the vertical flux of wave energy. References: Eliassen, A., & Palm, E., (1961), On the transfer of energy in stationary mountain waves, Geofysiske Publikasjoner, Oslo Sivertsen, T., (1976), On the transfer of energy in stationary mountain waves in an atmosphere with didcontinous parameters, Meteorologiske annaler Vol. 7 No. 3, Det Norske Meteorologiske Institutt Sivertsen T.H., 2005, Discussing the scientific method and a documentation systems of meteorological and biological parameters, Physics and Chemistry of the Earth Special Issue: Agrometeorology 2003, Vol 30/1-3 pp 35-43
Forfattere
Tor Håkon SivertsenSammendrag
The concept of classification of meteorological and agro meteorological / biological phenomena is defined as merely giving names to observed phenomena. Examples of certain phenomena are shortly presented, and then a rather unusual statement connected to the concept of classification is presented: Any physical and biological phenomenon contains a totality that includes time, space and consciousness. The concept of parameterization is used in the following manner: We connect measurable / quantitative entities to each phenomenon. The concept of parameter is then discussed as well as the ideas of constructing models containing the macro physics of the air or the micro-physics of the air. A few ideas connected to statistical mechanics are mentioned. And some of the ideas of the `physical laws" used in meteorology are discussed. References: Sivertsen T.H., 2005, Discussing the scientific method and a documentation systems of meteorological and biological parameters, Physics and Chemistry of the Earth Special Issue: Agrometeorology 2003, Vol 30/1-3 pp 35-43 Sivertsen, T.H., 2005, Implementation of a General Documentation System for web-based administration and use of historical series of meteorological and biological data, Physics and Chemistry of the Earth Special Issue: Agrometeorology 2003, Vol 30/1-3 pp 217-222 Sivertsen, T.H., 2005, Discussing scientific methods and the quality of meteorological data, in `Use and Availability of Meteorological Information from Different Sources as Input in Agrometeorological Models", COST ACTIONS 718 `Meteorological Applications for Agriculture", Edited by G. Maracchi, A. Mestre, L. Toulios and B. Gozzini. Sivertsen, T.H, 2005, ", Reflections on the Theme of Classifying, Documenting and Exchanging Meteorological Data", Atmospheric Science Letters, Vol.6 , Issue 3, p 171-175, John Wiley & Son
Forfattere
Tor Håkon SivertsenSammendrag
An interpretation of the scientific principle is presented and shortly discussed, containing the concepts of classification of physical phenomena, parameterization, `physical laws", construction of hypotheses and testing. Then the concept of continuity of the real number system ispresented. The Navier-Stokes equations , the equation of continuity, and the energy equations are interpreted , looking at the concepts of molecular diffusion and convective flow, and the physical content of the `physical laws" of conservation of mass, conservation of momentum and conservation of energy. The construction of the Reynolds equation is discussed by looking at the parameterization in time and space of fluid flow of different temporal and spatial scale. Turbulence is then interpreted as phenomena of fluid dynamics on a smaller scale than the scale of the system for making measurements in each operational situation. The discussion is completed by looking once more at the content of the `physical laws" of of conservation of mass, conservation of momentum and conservation of energy. References: Tennekes, H., & Lumley, J.J., (1972). A first course of turbulence. The MIT Press, Cambridge, Massachusets, and London, England. Yaglom, A.M., & Monin, A.S., (1987), statistical Fluid Mechanics, The MIT Press, , Cambridge, Massachusets, and London, England. Siveertsen, T.H.,(2004) Invitation to Conceptual Discussions Concerning the Scope of the Scientific Method and Classification of Meteorological Phenomena and Meteorological Parameters, P 185-190, Selected Papers of the International Conference `Fluxes and Structures in Fluids", St. Petersburg, Russia, June 23-26, 2003, Moscow, IPM RAS, 2004 Sivertsen, T.H.,(2004), Discussing the Concept of Continuity of Continuum Mechanics, P 190-193, Selected Papers of the International Conference `Fluxes and Structures in Fluids", St. Petersburg, Russia, June 23-26, 2003, Moscow, IPM RAS, 2004 Sivertsen, T.H., (2004), Discussing the Concept of Turbulence and a Proposal of a Classification System of Fluid Dynamical Parameters, P 193-196, Selected Papers of the International Conference `Fluxes and Structures in Fluids", St. Petersburg, Russia, June 23-26, 2003, Moscow, IPM RAS, 2004 Sivertsen T.H., 2005, Discussing the scientific method and a documentation systems of meteorological and biological parameters, Physics and Chemistry of the Earth Special Issue: Agrometeorology 2003, Vol 30/1-3 pp 35-43 Sivertsen, T.H, 2005, ", Reflections on the Theme of Classifying, Documenting and Exchanging Meteorological Data", Atmospheric Science Letters, Vol.6 , Issue 3, p 171-175, John Wiley & Sons
Forfattere
Tor Håkon SivertsenSammendrag
An interpretation of the scientific principle ( as this is used in the context of agro meteorology ) is presented and discussed, containing the concepts of classification of meteorological and biological phenomena, parameterization, testing and use of models. The ideas of pure and applied science are presented, and then the concept of scope of the scientific principle is discussed. Both the use of science for understanding nature, the use of science for implementing applications, and the use of science for understanding the consequences of the use of applications are contained in this discussion. The views and discussion are also extended towards society, and what should be the content of sustainable agricultural production. The concept of the relations of human beings to othe biological organisms and to past and future generations is a part of this discussion. References: Philip, J.R, (1991), Soils, natural science, and models, Soil science. 151:91-98 Addiscott, T.M., (1993), Simulation modelling and soil behaviour, Geoderma, 60: 15-40 Sivertsen, T.H.,(2004) Invitation to Conceptual Discussions Concerning the Scope of the Scientific Method and Classification of Meteorological Phenomena and Meteorological Parameters, P 185-190, Selected Papers of the International Conference `Fluxes and Structures in Fluids", St. Petersburg, Russia, June 23-26, 2003, Moscow, IPM RAS, 2004 Sivertsen T.H., 2005, Discussing the scientific method and a documentation systems of meteorological and biological parameters, Physics and Chemistry of the Earth Special Issue: Agrometeorology 2003, Vol 30/1-3 pp 35-43 Sivertsen, T.H., 2005, Discussing scientific methods and the quality of meteorological data, in `Use and Availability of Meteorological Information from Different Sources as Input in Agrometeorological Models", COST ACTIONS 718 `Meteorological Applications for Agriculture", Edited by G. Maracchi, A. Mestre, L. Toulios and B. Gozzini. Sivertsen, T.H, 2005, ", Reflections on the Theme of Classifying, Documenting and Exchanging Meteorological Data", Atmospheric Science Letters, Vol.6 , Issue 3, p 171-175, John Wiley & Sons
Forfattere
Tor Håkon SivertsenSammendrag
`Norwegian Institute for Agricultural and Environmental Research" is the owner of a network of meteorological stations, established in 1987. 45 of the stations are measuring global radiation, hourly values. These time series are to be used as one of the input parameters for modelling UV-radiation. Also several other meteorological parameters of relevance for modelling UV-radiation are measured in this station network and discussed below. A discussion on quality of these data contains general considerations on the concept of quality, considerations on the methods for making measurements at the specific series from a few sites as well as specific quality considerations on several other available time series of meteorological parameters, like the albedo, precipitation, relative humidity of the air, temperature of the air etc. from the sites. Elements describing the sites are mentioned, like information on the horizon, the geographical coordinates etc. The availability of independent time series of measurements of ozone, cloudiness, precipitation, content of aerosol and vertical distributions of humidity to be used in models are also discussed. Modelling UV-radiation at the ground is defined as a complex problem of data integration using data from different sources. The main part of this contribution contains discussion complex data integration.
Forfattere
Venche TalgøSammendrag
On the southwest coast of Norway there are natural stands of holly (Ilex aquifolium), but a number of different varieties of I. aquifolium and I. meserveae are also grown in bough production fields, private gardens and public parks. Except for conifers, holly is the only tree we have with green foliage during the winter in Norway. The leathery, dark green leaves with prickly spines and the red berries have made holly a popular plant for Christmas decorations. Leaf-drop/defoliation has become an increasing problem during the last decades both before and after harvest, and thus destroys the marketability. We suspect that reduced grazing has resulted in more overgrown/dense stands and hence created ideal microclimate for fungal growth. Wet foliage due to shade and restricted air movement gives the spores good conditions for germination. On investigated diseased plant material collected from holly in the period 2001-2006, a number of possible pathogenic fungi were isolated; Fusarium avenaceum, Vialaea insculpta, Nectria sp., Colletotrichum acutatum, Trochila ilicina and Diaporthe ilicis (Talgø et al. 2006). The fungi were identified morphologically mainly based on information given by Ellis & Ellis (1997). Colletotrichum was identified to species level by PCR. In the literature we find very little about what kind of damage these organisms may cause on holly. Benson & Jones (2000) say that leaf-spotting fungi on holly can cause heavy defoliation before new growth starts in the spring, but they do not mention any specific pathogen. Therefore we will run pathogenesis tests with all the fungi mentioned above to fulfil Koch"s postulate.
Forfattere
Ingrid HoltsmarkSammendrag
Lys ringråte på potet er forårsaket av den Gram-positive bakterien Clavibacter michiganensis subsp. sepedonicus (Cms). Lys ringråte er en utbredt plantesykdom, som forårsaker store økonomiske tap. En strategi som kan gi kontroll over sykdommen er utvikling av midler som spesifikt hemmer vekst av patogenet. I dette arbeidet har smalspektrede antimikrobielle stoffer som utskilles av den tomatpatogene slektningen, Clavibacter michiganensis subsp. michiganensis (Cmm), blitt renset og studert. Disse antimikrobielle stoffene hemmer vekst av Cms, og kan vise seg nyttige som midler i kampen mot ringråtepatogenet. De antimikrobielle stoffene omfatter et bakteriosin på 14 kDa, et lantibiotikum på 2145 Da og en rekke antibiotika med molekylmasser rundt 800-900 Da, som ser ut til å tilhøre tunicamycinfamilien. Det lantibiotiske peptidet, michiganin A, likner på actagardine, som er et type-B lantibiotikum produsert av actinomyceten Actinoplanes liguriae. Begge disse peptidene har likheter med mersacidin, som er et velkjent type-B lantibiotikum. Disse likhetene omfatter blant annet en konservert aminosyre som man tror er viktig for mersacidins antimikrobielle aktivitet. Det å oppnå større forståelse av mekanismene som styrer patogeniteten til Cms, er en vei mot bekjempelse av sykdommen. I tråd med dette ble det utført ekspresjonsanalyse av ni mulige virulensgener. Fem av de utvalgte genene er homologer av pat-1, et gen som antas å kode for en serin-protease som spiller en rolle i patogenitet hos Cmm, og gener som koder for celleveggnedbrytende enzymer (to cellulaser, en xylanase og en pektat-lyase). Genuttrykk ble målt med bruk av Real-Time PCR amplifisering av revers-transkribert RNA, fra celler fra kultur og fra infisert bladmateriale av potet. Genene som koder for de to cellulasene, xylanasen og to av Pat-1-homologene ble klart oppregulert under infeksjon. Uttrykket av pektat-lyasen ble kun svakt påvirket av infeksjon, mens de tre andre homologene av Pat-1 ble nedregulert. Den overbevisende oppreguleringen av de to cellulasene, xylanasen og to av homologene av Pat-1 under infeksjon, tyder på at disse proteinene er involvert i patogenitet, og avdekker dermed mål for videre studier av Cms.
Forfattere
Aksel DøvingSammendrag
Grunnlaget for jordbæravlinga vert lagt om hausten. Eit samspel mellom kortare dagar og fallande temperatur set i gang utviklinga av blomsteranlegg. Dette skjer i månadsskiftet august-september i Sør-Norge. Andre faktorar som tørke og knapp næringstilgang kan framskunde danninga av blomsteranlegg. Etter at utviklinga av blomsteranlegg først er komen i gang, er det som regel ein fordel med gode veksevilkår i september.