396 research outputs found
Cytisus scoparius : a genetic and historical analysis of introduction history in Norway
Cytisus scoparius is an invasive species threatening the local flora where the shrub is introduced. Studies show that the shrub spreads rapidly and has damaging effects in areas where the plant is considered invasive. Cytisus scoparius has been considered native in Norway but may threaten vulnerable habitats such as coastal heathlands, calling for a regulation of the shrub’s expansion. This study uses molecular and historical analysis to investigate if in fact C. scoparius is native to the Norwegian flora or if it is introduced through human actions. 28 Norwegian C. scoparius populations were sampled and compared with 27 non-Norwegian samples and 22 Norwegian herbaria samples. The samples were grouped into nine haplotypes and analyzed to find if there is a genetically distinct variation of C. scoparius in Norway, and to decide whether there has been a single or multiple introductions to Norway, and if there is a traceable introduction path. My results reveal high genetic variation among all samples. The nine haplotypes identified are scattered over a large area, which indicates multiple introductions to Norway and makes it difficult to trace possible introduction routes.M-BIO
Cytisus scoparius : a genetic and historical analysis of introduction history in Norway
Cytisus scoparius is an invasive species threatening the local flora where the shrub is introduced. Studies show that the shrub spreads rapidly and has damaging effects in areas where the plant is considered invasive. Cytisus scoparius has been considered native in Norway but may threaten vulnerable habitats such as coastal heathlands, calling for a regulation of the shrub’s expansion. This study uses molecular and historical analysis to investigate if in fact C. scoparius is native to the Norwegian flora or if it is introduced through human actions. 28 Norwegian C. scoparius populations were sampled and compared with 27 non-Norwegian samples and 22 Norwegian herbaria samples. The samples were grouped into nine haplotypes and analyzed to find if there is a genetically distinct variation of C. scoparius in Norway, and to decide whether there has been a single or multiple introductions to Norway, and if there is a traceable introduction path. My results reveal high genetic variation among all samples. The nine haplotypes identified are scattered over a large area, which indicates multiple introductions to Norway and makes it difficult to trace possible introduction routes.M-BIO
Full scale fishing trials for tusk (Brosme brosme) and cod (Gadus morhua) with a collapsible fish trap
A collapsible fish trap with low weight and low stacking
volume has been developed and tested in full scale fishing
operations. The catch rates of tusk were promising, while the
catches of cod were too low and variable to commercial
fishing operation
Experimental characterization of the marine atmospheric boundary layer in the Havsul area, Norway
Offshore wind energy applications depend strongly on an improved knowledge of the physical processes taking place in marine atmospheric boundary layer (MABL). In particular the better understanding of the complex interactions between wind shear, atmospheric stability and turbulence and the effects of wind-wave interactions on offshore vertical wind profiles are essential for the development of offshore wind projects. This paper presents an analysis of the relation between turbulence parameters, such as horizontal and vertical turbulence intensity, and turbulence kinetic energy and average vertical wind profiles and wind shear. The investigations are based on 4 years of wind lidar measurements on the small island of Storholmen in the Havsul area about 8 km off the coast of the Norwegian mainland. The results show systematic dep endencies between the investigated turbulence parameters, both with respect to average wind speeds and average wind shear. The results indicate that in particular the horizontal turbulence intensity has the potential to act as a proxy for atmospheric stability in cases where corresponding temperature profiles are not available.publishedVersio
Francisella philomiragia subsp. noatunensis i torskeleukocytter
Det er velkjent at en rekke intracellulære bakterier, inkludert flere arter innen slekten Francisella, har evne til å oppholde seg og formere seg i immuncellene. I dette studiet ble det utført smitteforsøk in vitro der det ved hjelp av spesifikke antistoffer ble vist at Francisella philomiragia subsp. noatunensis oppholder seg i fagocyttiske celler av myeloid opphav i tillegg til B-lymfocytter hos Atlantisk torsk (Gadus morhua L.). Dette kan være en effektiv strategi ved at bakterien unngår vertens humorale forsvarsmekanismer. Det er også verdt å merke seg at disse vertscellene er sentrale i det medfødte immunforsvarets bekjempelse av patogener. Tilstedeværelse av bakterier i nøytrofile granulocytter og B-lymfocytter indikerer at disse cellene kan infiseres av F. philomiragia subsp. noatunensis, men forekomsten av smittede nøytrofile granulocytter og B-lymfocytter var lav. Høy forekomst av intracellulære bakterier i adherente leukocytter tyder på at bakterien har preferanse for andre celletyper. Resultatene indikerte at F. philomiragia subsp. noatunensis formerer seg intracellulært i adherente leukocytter, men flere studier bør gjøres for å kunne stadfeste dette. Smitteforsøkene ble utført med F. philomiragia subsp. noatunensis som var sent i den eksponentiell vekstfase, og en vekstkurve ble utarbeidet for å fastslå tidspunkt for bakteriens ulike vekstfaser. Prosedyre for phalloidinmerking av adherente leukocyttpopulasjoner ble utprøvd, og merkingen var et godt egnet hjelpemiddel for å studere adherente leukocytters kvalitet på preparatene for å optimalisere dyrkningsforholdene i brønner. Phalloidin var også godt egnet til å merke leukocyttpopulasjoner etter smitteforsøk for å påvise og lokalisere intracellulære bakterier i adherente leukocytter ved fluorescens- og konfokalmikroskopi. Antiserumet mot Francisella som ble brukt til å merke bakteriene i forsøkene var spesifikt og reagerte med flere komponenter av antigenet i immunoblott. Ved merking med antiserumet kanin anti-Francisella og fluorokrom-konjugert sekundært antistoff kunne bakterien tydelig observeres i preparatene. Påvisning av bakterien intracellulært og kartlegging av hvilke leukocytter som smittes av bakterien kan bidra til økt kunnskap av sykdomsforløpet ved francisellose i tillegg til å fremskaffe nyttig kunnskap for bekjempelse av sykdommen.Master i FiskehelseMAMN-FISKFISK
Reduced bycatch of red king crab (Paralithodes camtschatica) in the cod gillnet fisheries in northern Norway: Fishing trials with norsel mounted gillnets
Bycatch of red king crab (Paralithodes camtschatica) in stationary fishing gears, q&ally
gillnets, is an increasing problem to the inshore fishermen in the northern part of Norway
(Finnmark county). The results are large bycatches of king crabs together with the crabs’
damages on the gear and catch. In the cod gillnet fisheries, the problem might be solved by
using specially made gillnets (“norsel-mounted” nets) where the net itself is floated 0.5 meters
above the seabed. The norsel-mounted nets were compared with standard nets in the
Varangerfjord (eastern Finnmark) in the period 17 March - 28 May 1999. The trials showed
that norsel nets needed more floats than the standard nets to get the net to stand properly in
the sea (to get the norsels stretched out suitably). By using extra float (rings) on the norsel
mounted nets the bycatches of king crab were reduced to an acceptable level with an average
of 0.6 crabs/net, compared with 3.3 crabs/net on standard and 6.7 crabs/net on nor-se1 nets
without extra float. Norse1 nets caught only about l/3 as many fish as standard nets.
The catch results indicated that the gear configuration functioned in order to reduce the
bycatch of red king crab. Loss of fish up to 65% is, however not satisfying. Further work is
needed to find a solution that gives a minimal loss of fish. Knowledge about the different
species’ behaviour is of importance in the further development of a more selective gear
Forsøk på fangst av levende vanlig uer: Tokt med F/F "Fjordfangst" på Nordlandskysten, august 1996
Modulation of the Pacific Decadal Oscillation on the summer precipitation over East China: a comparison of observations to 600-years control run of Bergen Climate Model
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