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.
2020
Forfattere
Hye-Seon Kim Jessica M. Lohmar Mark Busman Daren W. Brown Todd A. Naumann Hege Hvattum Divon Erik Lysøe Silvio Uhlig Robert H. ProctorSammendrag
Background Sphingolipids are structural components and signaling molecules in eukaryotic membranes, and many organisms produce compounds that inhibit sphingolipid metabolism. Some of the inhibitors are structurally similar to the sphingolipid biosynthetic intermediate sphinganine and are referred to as sphinganine-analog metabolites (SAMs). The mycotoxins fumonisins, which are frequent contaminants in maize, are one family of SAMs. Due to food and feed safety concerns, fumonisin biosynthesis has been investigated extensively, including characterization of the fumonisin biosynthetic gene cluster in the agriculturally important fungi Aspergillus and Fusarium. Production of several other SAMs has also been reported in fungi, but there is almost no information on their biosynthesis. There is also little information on how widely SAM production occurs in fungi or on the extent of structural variation of fungal SAMs. Results Using fumonisin biosynthesis as a model, we predicted that SAM biosynthetic gene clusters in fungi should include a polyketide synthase (PKS), an aminotransferase and a dehydrogenase gene. Surveys of genome sequences identified five putative clusters with this three-gene combination in 92 of 186 Fusarium species examined. Collectively, the putative SAM clusters were distributed widely but discontinuously among the species. We propose that the SAM5 cluster confers production of a previously reported Fusarium SAM, 2-amino-14,16-dimethyloctadecan-3-ol (AOD), based on the occurrence of AOD production only in species with the cluster and on deletion analysis of the SAM5 cluster PKS gene. We also identified SAM clusters in 24 species of other fungal genera, and propose that one of the clusters confers production of sphingofungin, a previously reported Aspergillus SAM. Conclusion Our results provide a genomics approach to identify novel SAM biosynthetic gene clusters in fungi, which should in turn contribute to identification of novel SAMs with applications in medicine and other fields. Information about novel SAMs could also provide insights into the role of SAMs in the ecology of fungi. Such insights have potential to contribute to strategies to reduce fumonisin contamination in crops and to control crop diseases caused by SAM-producing fungi.
Sammendrag
Laser scanning data from unmanned aerial vehicles (UAV-LS) offer new opportunities to estimate forest growing stock volume ( V ) exclusively based on the UAV-LS data. We propose a method to measure tree attributes and using these measurements to estimate V without the use of field data for calibration. The method consists of five steps: i) Using UAV-LS data, tree crowns are automatically identified and segmented wall-to-wall. ii) From all detected tree crowns, a sample is taken where diameter at breast height (DBH) can be recorded reliably as determined by visual assessment in the UAV-LS data. iii) Another sample of crowns is taken where tree species were identifiable from UAV image data. iv) DBH and tree species models are fit using the samples and applied to all detected tree crowns. v) Single tree volumes are predicted with existing allometric models using predicted species and DBH, and height directly obtained from UAV-LS. The method was applied to a Riegl-VUX data set with an average density of 1130 points m−2 and 3 cm orthomosaic acquired over an 8.8 ha managed boreal forest. The volumes of the identified trees were aggregated to estimate plot-, stand-, and forest-level volumes which were validated using 58 independently measured field plots. The root-mean-square deviance ( RMSD% ) decreased when increasing the spatial scale from the plot (32.2%) to stand (27.1%) and forest level (3.5%). The accuracy of the UAV-LS estimates varied given forest structure and was highest in open pine stands and lowest in dense birch or spruce stands. On the forest level, the estimates based on UAV-LS data were well within the 95% confidence interval of the intense field survey estimate, and both estimates had a similar precision. While the results are encouraging for further use of UAV-LS in the context of fully airborne forest inventories, future studies should confirm our findings in a variety of forest types and conditions.
Forfattere
Melesse Eshetu Moges Arve Heistad Thorsten HeidornSammendrag
The blackwater stream of domestic wastewater contains energy and the majority of nutrients that can contribute to a circular economy. Hygienically safe and odor-free nutrient solution produced from anaerobically treated source-separated blackwater through an integrated post-treatment unit can be used as a source of liquid fertilizer. However, the high water content in the liquid fertilizer represents a storage or transportation challenge when utilized on agricultural areas, which are often situated far from the urban areas. Integration of microalgae into treated source-separated blackwater (BW) has been shown to effectively assimilate and recover phosphorus (P) and nitrogen (N) in the form of green biomass to be used as slow release biofertilizer and hence close the nutrient loop. With this objective, a lab-scale flat panel photobioreactor was used to cultivate Chlorella sorokiniana strain NIVA CHL 176 in a chemostat mode of operation. The growth of C. sorokiniana on treated source-separated blackwater as a substrate was monitored by measuring dry biomass concentration at a dilution rate of 1.38 d−1, temperature of 37 °C and pH of 7. The results indicate that the N and P recovery rates of C. sorokiniana were 99 mg N L−1d−1 and 8 mg P L−1d−1 for 10% treated BW and reached 213 mg N L−1d−1 and 35 mg P L−1d−1, respectively when using 20% treated BW as a substrate. The corresponding biomass yield on light, N and P on the 20% treated BW substrate were 0.37 g (mol photon)−1, 9.1 g g−1 and 54.1 g g−1, respectively, and up to 99% of N and P were removed from the blackwater.
Sammendrag
Various studies investigated the fate of evaporation and the origin of precipitation. The more recent studies among them were often carried out with the help of numerical moisture tracking. Many research questions could be answered within this context, such as dependencies of atmospheric moisture transfers between different regions, impacts of land cover changes on the hydrological cycle, sustainability-related questions, and questions regarding the seasonal and interannual variability of precipitation. In order to facilitate future applications, global datasets on the fate of evaporation and the sources of precipitation are needed. Since most studies are on a regional level and focus more on the sources of precipitation, the goal of this study is to provide a readily available global dataset on the fate of evaporation for a fine-meshed grid of source and receptor cells. The dataset was created through a global run of the numerical moisture tracking model Water Accounting Model-2layers (WAM-2layers) and focused on the fate of land evaporation. The tracking was conducted on a 1.5∘×1.5∘ grid and was based on reanalysis data from the ERA-Interim database. Climatic input data were incorporated in 3- to 6-hourly time steps and represent the time period from 2001 to 2018. Atmospheric moisture was tracked forward in time and the geographical borders of the model were located at ±79.5∘ latitude. As a result of the model run, the annual, the monthly and the interannual average fate of evaporation were determined for 8684 land grid cells (all land cells except those located within Greenland and Antarctica) and provided via source–receptor matrices. The gained dataset was complemented via an aggregation to country and basin scales in order to highlight possible usages for areas of interest larger than grid cells. This resulted in data for 265 countries and 8223 basins. Finally, five types of source–receptor matrices for average moisture transfers were chosen to build the core of the dataset: land grid cell to grid cell, country to grid cell, basin to grid cell, country to country, basin to basin. The dataset is, to our knowledge, the first ready-to-download dataset providing the overall fate of evaporation for land cells of a global fine-meshed grid in monthly resolution. At the same time, information on the sources of precipitation can be extracted from it. It could be used for investigations into average annual, seasonal, and interannual sink and source regions of atmospheric moisture from land masses for most of the regions in the world and shows various application possibilities for studying interactions between people and water, such as land cover changes or human water consumption patterns. The dataset is accessible under https://doi.org/10.1594/PANGAEA.908705 (Link et al., 2019a) and comes along with example scripts for reading and plotting the data.
Sammendrag
The Norwegian coastal goat is a national and endangered breed. Coastal goat populations are mainly divided with a large mainland and two small island populations. The objective of this study is to describe genetic diversity in the feral Skorpa island population and its relationship to the mainland coastal goat population (Selje) using the Norwegian milk goat population as a reference. Analyses were based on 96 samples genotyped by the CaprineSNP50 Beadchip from three populations; 7 Skorpa (SK), 37 Selje (SE) and 52 Norwegian milk goats (MG). The SK population had significantly less genetic variation and higher levels of inbreeding than the two other populations. It was more distant from the two mainland populations than they were from each other. The marginal contribution of the SK population to genetic diversity was small. Means of introducing genetic diversity into the SK population should be considered if the population is prioritized for conservation.
Forfattere
Abdelhameed Elameen Vera M. Kosman Mette Thomsen Olga N. Pozharitskaya Alexander N. ShikovSammendrag
Rhodiola rosea L. (roseroot) is an adaptogen plant belonging to the Crassulaceae family. The broad spectrum of biological activity of R. rosea is attributed to its major phenyletanes and phenylpropanoids: rosavin, salidroside, rosin, cinnamyl alcohol, and tyrosol. In this study, we compared the content of phenyletanes and phenylpropanoids in rhizomes of R. rosea from the Norwegian germplasm collection collected in 2004 and in 2017. In general, the content of these bioactive compounds in 2017 was significantly higher than that observed in 2004. The freeze-drying method increased the concentration of all phenyletanes and phenylpropanoids in rhizomes compared with conventional drying at 70 °C. As far as we know, the content of salidroside (51.0 mg g−1) observed in this study is the highest ever detected in Rhodiola spp. Long-term vegetative propagation and high genetic diversity of R. rosea together with the freeze-drying method may have led to the high content of the bioactive compounds observed in the current study.
Forfattere
Lars Rød-Eriksen Johanna Skrutvold Ivar Herfindal Henrik Jensen Nina Elisabeth EideSammendrag
1. Habitat fragmentation may affect species distributions through, for example, altered resource availability and shifts in species interactions. Fragmentation by roads has had negative impacts on Fennoscandian alpine ecosystems, with reduction of habitats and connectivity for alpine species. Concurrently, infrastructure development causes influx of subsidies through roadkills and litter, which may facilitate expansion of boreal scavenging species, such as the red fox Vulpes vulpes, which may intensify negative interactions with alpine species. Hence, understanding the impact of subsidies within marginal alpine areas is imperative for successful conservation and management of particularly vulnerable alpine species. 2. We used snow tracking and camera traps in three alpine tundra areas in Norway to investigate whether the presence of boreal scavengers was positively associated with highways during winter, and if this contrasted the pattern of a critically endangered alpine species, the Arctic fox Vulpes lagopus. In summer, artificial nests were used to assess whether predation risk was related to proximity to highways. 3. During winter, the occurrence of red foxes was higher close to highways and decreased with increasing distance to highways, while the arctic fox showed no discernible pattern. Red fox occurrence increased with the number of edible items of anthropogenic origin located along highways, whereas arctic fox occurrence decreased. 4. The overall predation risk of artificial nests during summer was high (>31.2%) and increased with proximity to the highway in the area with highest traffic volume. 5. Synthesis and applications. Highways crossing alpine areas may attract boreal scavengers, possibly connected to increased access to subsidies of anthropogenic origin. Litter and food waste dominated available subsidies along highways in our study, and prevailing mitigating measures directed at reducing roadkill and movement restrictions may not be applicable to reduce negative effects of littering. We recommend actions focusing on informational campaigns, improved garbage disposal facilities and routines, and imposing fines for littering, to reduce negative impacts on vulnerable species. This is likely needed to achieve goals of ‘no impact’ from the physical loss of habitats due to road development.
Forfattere
Ivar Pettersen Ingrid RomsaasSammendrag
The prevailing understanding on the use of temporary work contracts is that the situation is stable, that the great majority of employees work on long-term contracts. Extensive use of rented labour and irregular work relations is considered to be an issue primarily in the building and Construction sector. Our analysis shows that there is more variation in the use of temporary contracts through specialized work agencies than previously perceived. In the study, we employ microeconomic data from annual accounts to investigate the variability between subsectors of the food and beverages industry. Our analysis also includes some data for distributive trades for comparison.
Sammendrag
To support decision-makers considering adopting integrated pest management (IPM) cropping in Norway, we used stochastic efficiency analysis to compare the risk efficiency of IPM cropping and conventional cropping, using data from a long-term field experiment in southeastern Norway, along with data on recent prices, costs, and subsidies. Initial results were not definitive, so we applied stochastic efficiency with respect to a function, limiting the assumed risk aversion of farmers to a plausible range. We found that, for farmers who are risk-indifferent to moderately (hardly) risk averse, the conventional system was, compared to IPM, less (equally) preferred.
Sammendrag
Nydyrking skal bidra til å gjøre mer areal tilgjengelig til matproduksjon eller annen jordbruksproduksjon. Nydyrking av arealer går på bekostning av skog og utmark. Det er større næringsstoffavrenning fra jordbruksarealer enn fra skog og utmark, og når arealer nydyrkes og andelen jordbruksarealer øker i et område kan det også bli økt næringsstoffavrenning, økt risiko for eutrofiering og redusert vannkvalitet. Overvåkingsresultater viser at avrenningen av fosfor i gjennomsnitt er 56 ganger høyere fra jordbruksarealer enn fra skog og utmark, avrenningen av nitrogen i gjennomsnitt 17 ganger høyere og erosjonen hele 106 ganger høyere. Avrenningen av næringsstoffer fra jordbruksarealer avhenger blant annet av produksjonen. Nydyrkingsarealer med ekstensiv grasproduksjon har betraktelig lavere næringsstoffavrenning enn nydyrkingsarealer med korn, potet eller grønnsaker. Størrelsen på nydyrkingsarealet har betydning for hvor mye vannforekomsten påvirkes. Dessuten er noen vannforekomster mer følsomme for påvirkning enn andre. Det kan gjennomføres tiltak, f.eks. grasdekte kantsoner og fangdammer, som bidrar til å redusere næringsstoff-tilførslene til vannforekomster.