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
Forfattere
Nina JohansenSammendrag
Continuous light is a promising method to reduce the problems with rose powderymildew in greenhouse rose production. The effects of such a light regime on the performance of insect pests on roses have so far not been investigated. In the present study, survival, developmental time, and reproduction during one generation of the greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae), were characterized on roses, Rosa x hybrida cv. Passion, grown in climate chambers with long-day conditions (L20:D4) or continuous light (L24:D0) at 21 oC and fluctuating relative humidity (mean 74%, range 47–96%). Whiteflies reared under continuous light had lower immature survival and fecundity and shorter female longevity than whiteflies reared under long-day conditions, but immature developmental time was only slightly affected. Life-table analysis showed that the net reproductive rate (Ro) and intrinsic rate of natural increase (rm) were reduced by 85 and 76%, respectively, and the time for the population to double its size (D) was 4.2 times longer under continuous light. Thismean that the whitefly population growth under continuous light was strongly reduced compared with the traditional light regime used in rose production.
Forfattere
Nils Vagstad Helen French H.E. Andersen H. Behrendt B. Grizzetti P. Groenendijk A. Lo Porto H. Reisser C. Siderius J. Stromquist J. Hejzlar Johannes DeelstraSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Rune Slimestad Eivind Vangdal Cato BredeSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Svein Solberg Mathias Dobbertin Gert Jan Reinds Holger Lange Kjell Andreassen Paloma Garcia Fernandez Anders Hildingsson Wim de VriesSammendrag
Det er ikke registrert sammendrag
Forfattere
Håkan Broman Mikael Frisk Mikael RönnqvistSammendrag
Det er ikke registrert sammendrag
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
Det er ikke registrert sammendrag
Forfattere
Mauritz ÅssveenSammendrag
Det er ikke registrert sammendrag
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.