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.
2009
Authors
Dugassa N. Feyissa Trond Karsten Løvdal Kristine Marie Olsen Rune Slimestad Cathrine LilloAbstract
The bHLH transcription factors EGL3 (ENHANCER OF GLABRA3) and its close homologue GL3 (GLABRA3) are important regulators of the anthocyanin pathway in Arabidopsis thaliana, and together with TTG1 (a WD40 repeat protein) and MYB transcription factors regulate specific genes in the pathway. In response to nitrogen depletion, the MYB genes PAP1/PAP2 (production of anthocyanin pigment 1/2) and GL3 are strongly induced, and anthocyanin synthesis is activated in seedlings and rosette stage plants. In this study we show that anthocyanins accumulate in both wild type and egl3, but not in gl3 loss-of-function mutants when depleted of nitrogen. Several structural genes of flavonoid metabolism including CHS (chalcone synthase), FLS1 (flavonol synthase 1) and ANS (anthocyanidin synthase) were induced in response to nitrogen depletion in wild type as well as in the egl3 and gl3 mutants. Strikingly, in the gl3 mutant DFR (dihydroflavonol-4-reductase) transcript level was only 2% of the levels in wild type or egl3 mutant. Hence, low expression of DFR appears to be the bottleneck preventing anthocyanin synthesis in the gl3 mutant. The specific effect on DFR, but not ANS is compatible with involvement of the MYBL2 inhibitor.
Authors
Jan Inge Jenssen Erlend NybakkAbstract
This paper examines the relationship between external relations and innovation in small, knowledge-intensive Norwegian firms. Our findings indicate that external relations are beneficial for innovation. The analysis shows that it is necessary to treat innovation as more than a concept. Our independent variables related differently to product innovation, process innovation, and market innovation. We found that market participation in product development has a positive impact on product, process and market innovation. We also found that top management interaction with other firms had a positive effect on market innovation and that top management interaction with external R&D had a positive effect on product innovation. This finding probably indicates that access to R&D resources is vital for product development in the context of knowledge-intensive products. The results also show that participation in conferences and courses positively influences process and market innovation and that systematic environmental scanning positively influences product innovation.
Authors
Subal C. Kumbhakar Gudbrand LienAbstract
No abstract has been registered
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No abstract has been registered
Authors
Miklós Tóth Ferenc Szentkirályi József Vuts Agostino Letardi Maria Rosaria Tabilio Gunnhild Jaastad Geir Kjølberg KnudsenAbstract
No abstract has been registered
Authors
Aksel DøvingAbstract
No abstract has been registered
Authors
Randi Therese Garmo Adam Dunstan Martin Adam Dunstan Martin Erling Thuen Øystein Havrevoll Håvard Steinshamn Egil Prestløkken Åshild T. Randby Åshild T. Randby Margrete Eknæs Andres Waldmann Olav ReksenAbstract
Progesterone profiles in Norwegian Red cows were categorized, and associations between the occurrence of irregularities in the profiles and the commencement of luteal activity were investigated. The cows were managed in 3 feeding trials from 1994 to 2001 and from 2005 to 2008 at the Norwegian University of Life Sciences. The cows were followed from calving, and the milk samples collected represented 502 lactations from 302 cows. Milk samples for progesterone analysis were taken 3 times weekly from 1994 throughout 1998 and from 2005 to 2008 and 2 times weekly from 1999 to 2001. Commencement of luteal activity was defined as the first day of 2 consecutive measurements of progesterone concentration >= 3 ng/mL not earlier than 10 d after calving. Delayed ovulation type I was defined as consistently low progesterone concentration, <3 ng/mL for >= 50 d postpartum. Delayed ovulation type II was defined as prolonged interluteal interval with milk progesterone measurements <3 ng/mL for >= 12 d between 2 luteal phases. Persistent corpus luteum (PCL) type I was defined as delayed luteolysis with milk progesterone >= 3 ng/mL for >= 19 d during the first estrous cycle postpartum. Persistent corpus luteum type II was defined as delayed luteolysis with milk progesterone >= 3 ng/mL for >= 19 d during subsequent estrous cycles before first artificial insemination. Delayed ovulation type I was present in 14.7%, delayed ovulation type II in 2.8%, PCL type I in 6.7%, and PCL type II in 3.3% of the profiles. Commencement of luteal activity was related to milk yield, parity, PCL type I, and the summated occurrence of PCL type I and II. The least squares means for the interval to commencement of luteal activity were 24.2 d when PCL type I and II were present and 29.5 d when PCL type I and II were absent. The likelihood of pregnancy to first service was not affected in cows with a history of PCL when artificial insemination was carried out at progesterone concentrations <3 ng/mL (i.e., during estrus); however, cows that had experienced PCL were more likely to be inseminated during a luteal phase. The occurrence of delayed ovulation and PCL in Norwegian Red cows was less than that reported in most other dairy populations.
Authors
Knut Hovstad Harry WaldelandAbstract
No abstract has been registered
Authors
Randi Therese Garmo Erik Ropstad Øystein Havrevoll Erling Thuen Håvard Steinshamn Andres Waldmann Olav ReksenAbstract
Relationships among commencement of luteal activity (C-LA), milk yield, and energy balance (EB) were investigated in 3 selection lines of Norwegian Red cows at the Norwegian University of Life Sciences from 1994 through 2001. The cows were selected for low genetic merit for milk yield (LMP), high genetic merit for milk yield (HMP), and a combination of high indices for milk yield and fertility (HI). Breeding values for fertility were based on 56-d nonreturn rate. The material included 268 lactations from 147 cows. Milk samples for progesterone analysis were drawn 3 times weekly from 1994 through 1998, and 2 times weekly from 1999 to 2001. Commencement of luteal activity was defined as the first 2 consecutive measurements of progesterone concentration > 3 ng/mL not earlier than 10 d after calving. Selection line was significantly related to C-LA, so that the least squares mean days from calving to C-LA were 22.5, 30.4, and 27.2 d for LMP, HMP, and HI cows, respectively. The HMP cows produced more milk than the LMP cows. The average milk yield in the sixth week of lactation was 24.0, 27.1, and 25.3 kg for LMP, HMP, and HI cows, respectively. The interval to C-LA decreased for the HMP and HI cows after phenotypic adjustment for EB in the model. Least squares means for the interval to C-LA were 23.2, 29.7, and 25.6 d for the LMP, HMP, and HI cows, respectively, in a model that included parity, selection lines, and EB as covariates. Cumulated EB during the first 4 wk of lactation, which itself differed between selection lines, did not fully account for differences in interval to C-LA between selection lines. Thus, the results of the present investigation indicate that selection for milk yield negatively affects C-LA over and above the effects caused by concurrent changes in EB. The increase in days to C-LA caused by selection for high yields can be reduced if selection for milk yield is combined with fertility in the breeding program.
Abstract
No abstract has been registered