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.
2008
Forfattere
Peter Simon Erik JonerSammendrag
In this paper, we made an attempt to assess the conceivable interactions of insoluble, persistent nanoparticles with food matrix and living systems following from their physicochemical properties and to outline the analytical methods for the nanoparticles determination in food matrix. It is reasoned that adsorption of species and agglomeration and ageing of nanoparticles are phenomena originating in the relaxation of surface free energy. Further it has been deduced that nanoscale materials have a unique aility to interact with proteins and other biopolymers. The deductions also underline the catalytic activity of nanoparticles, primarily in oxodative reactions which may lead to the formation of reactive oxygen species and to the oxidative stress. The ability of nanoparticles to act as nuclei or germs in the induced heterogeneous crystallization is also considered.
Forfattere
H Dupré de Boulois Erik Joner C Leyval I Jakobsen B.D. Chen P Roos Y Thiry G Rufyikiri B Delvaux S DeclerckSammendrag
This review summarizes current knowledge on the contribution of mycorrhizal fungi to radiocesium immobilization and plant accumulation. These root symbionts develop extended hyphae in soils and readily contribute to the soil-to-plant transfer of some nutrients. Available data show that ecto-mycorrhizal (ECM) fungi can accumulate high concentration of radiocesium in their extraradical phase while radiocesium uptake and accumulation by arbuscular mycorrhizal (AM) fungi is limited. Yet, both ECM and AM fungi can transport radiocesium to their host plants, but this transport is low. In addition, mycorrhizal fungi could thus either store radiocesium in their intraradical phase or limit its root-to-shoot translocation. The review discusses the impact of soil characteristics, and fungal and plant transporters on radiocesium uptake and accumulation in plants, as well as the potential role of mycorrhizal fungi in phytoremediation strategies.
Forfattere
Matias Pasquali Erik Lysøe Andrew Breakspear Kyeyong Seong Jon Menke Jin-Rong Xu H. Corby KistlerSammendrag
To understand mycotoxin accumulation and the infection cycle of the wheat head blight pathogen Fusarium graminearum sensu stricto,fungal gene expression profiles were monitored during plant infection. Strains containing mutations in genes for three transcription factors were found to control deoxynivalenol (DON) accumulation in planta and pathogenicity. Expression profiles were compared between wildtype and these mutants during infection of wheat. Mutants deleted for the StuA gene were greatly decreased in sporulation and produced no perithecia in culture. Unlike "stuA mutants in F. oxysporum, F. graminearum "stuA mutants were greatly reduced in pathogenicity. Reduced pathogenicity may be due to decreased DON levels in planta, which in the mutant were
Forfattere
Eivind Vangdal Sigrid Flatland Ingvill Kristine MehlSammendrag
Det er gjennomført forsøk med bladgjødsling i plomme i Vest-Norge. I eit forsøk vart moglege effektar av ekstra magnesium, kalium og kombinasjonen av både magnesium og kalium på avling og fruktkvalitet studert og samanlikna med eit standard bladgjødslingsprogram. I eit anna eksperiment vart verknaden av eit bladgjødslingsprogram samanlikna med berre gjødsling på bakken. Avling, fruktstorleik og viktige fruktkvalitetsfaktorar vart målt. Innhaldet av viktige næringsemne vart analysert i blad og frukter. Ingen sterke effektar av bladgjødsling med magnesium og/eller kalium vart påvist. Bladgjødslingane påverka ikkje innhaldet av næringsemne i blad og frukter så mykje at ein kunne venta signifikante utslag på fruktkvaliteten. Bladgjødslinga syntest å utsetja mogninga sidan det var tenmdensar til at fruktene var grønare og med mindre dekkfarge, var fastare og med mindre oppløyst turrstoff og meir titrerbar syre. Tendensen for kvar einskild faktor var ikkje signifikant. Dei bladgjødsla trea syntest ha høgare innhald av nitrogen og mindre av dei andre næringsemna samanlikna med kontrolltre.
Forfattere
Eivind Vangdal Sigrid FlatlandSammendrag
Norske plommedyrkarar og omsetjarar arbeider for å heva statusen til norske plommer i friskfruktmarknaden. For å sikra at berre plommer med einsarta høg kvalitet vert marknadsførde, har ein teke i bruk sorteringsmaskiner på fruktlagra. Men plommeplukkarane må øvast opp i vurdering av mogningstid ved hausting. Metodar og hjelpemiddel for å gje plukkarar og omsetjarar ei felles forståing av mogningsgrad har vorte prøvd. Ein har utarbeidd fargekart og bilete som viser mogningsgraden i dei viktigaste plommesortane som vert dyrka i Norge. Men for plommesorten "Jubileum" er den beste måten å vurdera rett haustetid fastleik. Den bærbare franske fastleiksmålaren Durofel er nyttig i slik opplæringav plukkarar til å vurdera mogningsgrad i "Jubileum". Grenseverdiar for fastleik (målt med Durofel) for ulike mogningsgrader er fastlagde.
Sammendrag
Søtkirsebærtre vart sprøyta med kalsiumoppløysing ei gong kvar veke frå krunbladfall til to veker før hausting. Frukt frå trea som hadde fått kalsiumtilførsel, hadde høgare innhald av oppløyst turrstoff. Det var ikkje signifikante skilnader i farge, fastleik og syreinnhald. Bladgjødsling med kalsium reduserte utviklinga av kutikulære frakturar på fruktene. Fruktene frå kalsiumsprøyta tre mista meir vekt under lagring enn frukter frå kontrolltre. Hjå kontrollfrukter med mange kutikulære frakturar var vekttapet større enn hjå tilsvarande frukter med få frakturar. Hjå frukter som var tilført kalsium som bladgjødsling, derimot, var det ingen skilnad i vekttapet mellom frukter med mange eller få kutikulære frakturar. Dette indikerer at dei kutikulære frakturane i kalsiumsprøyta frukt var mindre alvorlege (djupe). Innhaldet av fenoliske sambindingar var større i kalsiumsprøyta frukt enn i kontrollfrukt. Færre kutikulære frakturar, mindre alvorlege (djupe) frakturar og auka innhald av fenolar kan vera ulike mekanismar for reduksjonen i risikoen for soppsjukdomar som ein observerer i kalsiumsprøyta søtkirsebær.
Forfattere
M. Bagher Farmani Nils-Otto Kitterød Henk KeersSammendrag
A method is presented to estimate flow parameters and geological structure in the vadose zone by combining time-lapse Ground Penetrating Radar (GPR) traveltime tomography and inverse flow modeling. The traveltime tomography is used to determine the spatial electromagnetic velocity distribution in the vadose zone. These time-lapse velocity images are converted to time-lapse volumetric soil water content images using petrophysical relationships. Subsequently, the water content images are used as constraints in the flow inversion. The influence of the tomographic artifacts on the flow inversion is minimized by assigning weights that are proportional to the ray coverage. Our flow inversion algorithm estimates the flow parameters and calibrates the geological structure. The geological structure is defined using a set of control points, the positions of which can be modified during the inversion. After the inversion, the final geological and flow model are used to compute GPR traveltimes to check the consistency between these computed traveltimes and the observed traveltimes.The method is first tested on two synthetic models (a steady state and a transient flow models). Subsequently, the method is applied to characterize a real vadose zone at Oslo Airport Gardermoen, Norway, during the snowmelt in 2005. The flow inversion method is applied to locate and quantify the main geological layers at the site. In particular the inversion method identifies and estimates the location and properties of thin dipping layers with relatively lowpermeability. The flow model is cross validated using an independent infiltration event.
Forfattere
Flavio Da Ronch Line RosefSammendrag
Semi-natural grasslands are important component for the biodiversity and landscape diversity in Norway and Italy. Both regions have problems of abandonment or under-stocking of their grassland as a result of changes in livestock management during the last decades. Especially in semi-natural pastures, the grazing activity is fundamental to maintain biodiversity and landscape diversity. The effects of grazing restoration in abandoned or heavy under-stocked areas were therefore investigated in two different regions in Europe. These areas were Orkdal and Gaular in Norway and Prealpi venete in Italy. The objectives were 1: to see if the vegetation (plant functional traits) in response to grazing is the same in both regions, and 2: to see if the biodiversity response to the grazing is the same in both regions. Several pastures were investigated in both regions in order to value the effects of the grazing on the vegetation. Soil properties, plant functional traits, biodiversity and pastoral value were studied before and after the restarting of grazing in both areas. Grazing activities influence floristic composition in Italy more than in Norway. There were no significant changes in the soil properties in both regions. Shannon Index show an increase consequently to grazing restoration.
Sammendrag
In Central-Norway, Anthriscus sylvestris, Deschamspia cespitosa and Alnus incana are well known re-growth species in abandoned areas. They often dominate abandoned areas and reduce the species biodiversity. Objectives of these field-studies were to find proper management strategies that reduce the plant cover of A. sylvestris, D. cespitosa and A. incana in semi-natural grasslands and thereby conserve or increase the biodiversity. In road-verges dominated by A. sylvestris management studies by different mowing strategies was recorded during four years. The response of D. cespitosa, A. sylvestris and A. incana to four different grazing regimes was investigated in abandoned grasslands for four years. Results from the field studies show that areas dominated by these species request specific, extraordinary, intensive and long-term management strategies.
Sammendrag
This work clearly demonstrates that the farming practices affect the species composition in semi"natural grasslands, and differs from location to location. Therefore, the former management and succession phase have to be identified for each semi"natural grassland so that the correct farming practices can be used.