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.
2023
Forfattere
Amos Samkumar Rajan Premkumar Katja Hannele Karppinen Inger Martinussen Richard V. Espley Laura Elina JaakolaSammendrag
Wild berries are abundant in health-beneficial bioactive compounds, such as flavonoids, carotenoids, vitamins, and polyphenolic compounds, which accumulate during the fruit ripening process. Interestingly, wild Vaccinium berries from northern latitudes are found to contain more bioactive compounds compared to southern clones. The genetic adaptation is most likely favoured by environmental conditions, such as extended day length, cool temperatures and light spectral qualities. The molecular mechanisms underlying the regulation of secondary metabolite biosynthesis in response to light quality have been scarcely explored in Vaccinium berries. The present study is focused on gaining knowledge on the regulatory process under supplemental red and blue light in non-climacteric wild bilberry (Vaccinium myrtillus L.). Controlled experiments were carried out in phytotrons with local Norwegian ecotypes of bilberry, which were subjected from early to late ripening stages to continuous exposure to specific red and blue wavelengths provided by light-emitting diodes (LEDs). Berry samples from mid-ripening stage were utilized for the gene expression analysis based on RNA-seq transcriptome profiling. Our recent analyses from the transcriptome data set have shown that light wavelengths induce the anthocyanin biosynthetic genes, resulting in higher delphinidin accumulation in ripe bilberries. The enhanced secondary metabolic pathways influenced by such light qualities and the differential expression patterns in light-reaction centers as observed in various subunit complexes of photosystem I and II in the photosynthetic apparatus are briefly discussed in this study. This is crucial in order to study how plants acclimatize to modified light environment in terms of photosynthesis. The differences in expression of hormone signal transduction pathway genes were also discussed. The results will contribute to a better understanding of the light-mediated biosynthesis of phytochemicals in Vaccinium berries.
Sammendrag
Lignosulphonates are water-soluble polymeric by-products from wood pulp production using sulphite pulping and can be used as soil amendments in agriculture, amongst other uses. Here, we review effects of lignosulphonates as biostimulants and in enhancing the action of fertilizers. In soils, they affect the nitrogen and phosphorous cycles, as well as acting as transporters of micronutrients. The action of tree-associated fungi can be improved, and plant growth and yield can be increased. The beneficial effects of lignosulphonates in agriculture mean that there is likely to be a market for commercial specialty lignosulphonate products.
Forfattere
Michael Altgen Michael Fröba Julius Gurr Andreas Krause Martin Ohlmeyer Uta Sazama Wim Willems Martin NopensSammendrag
Water-sorption studies and certain organic chemistry reactions require water removal from cellulosic samples. This is hindered by the strong interaction of cellulosic materials with water, and it remains uncertain if a completely anhydrous state can be reached under common drying conditions. Here, different drying conditions were applied to wood and cellulose, and the residual moisture contents were quantified either gravimetrically or by coulometric Karl-Fischer titration. Vacuum-drying at 103 °C and ≤ 1 mbar for at least 360 min decreased the moisture content to ≤ 0.04%. However, in automated sorption balances, drying at atmospheric pressure under dry air or nitrogen flow left some samples with more than 1% moisture content. The residual moisture content obtained under dry gas flow was temperature dependent. Increasing the temperature up to 55 °C decreased the residual moisture content and cooling resulted in a moisture re-uptake, presumably due to small quantities of water vapor in the surrounding atmosphere. These effects must be considered in fundamental studies on water interactions of cellulosic materials.
Forfattere
Paul Eric Aspholm Simo Maduna Juho Vuolteenaho Cornelya Klutsch Hallvard Jensen Ida Marie Luna Fløystad Ingrid Helle Søvik Ane-Sofie Bednarczyk Hansen Runar Kjær David Kniha Josefine Bergs Snorre HagenSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er behov for en bedre forståelse av hvordan veitrafikkstøy påvirker dyreliv langs vei til bruk i planlegging av veiprosjekter og vurdering av effekten av ulike tiltak for å redusere støybelastning. Vi gjennomførte en kunnskapssammenstilling for Statens Vegvesen der vi trakk ut hovedeffekter av veitrafikkstøy for et utvalg artsgrupper og pekte på noen sentrale kunnskapshull. Dokumentasjonen av negative effekter av veitrafikkstøy på dyreliv er omfattende, men med et sterkt fokus på korttidseffekter på enkeltindividers funksjon og lite på langtidseffektene på reproduksjon og overlevelse. Dette er avgjørende for dynamikken i populasjoner og samfunn. Studier antyder komplekse effekter av veitrafikkstøy alt etter hvordan de direkte og indirekte effektene påvirker artene i et system, men det er ikke godt dokumentert. Hovedvekten av studiene er på noen få artsgrupper som bruker lyd i kommunikasjon eller fødesøk (fugler, flaggermus og frosk), mens det er få studier på andre artsgrupper. Det gjelder også hvordan effekten av veitrafikkstøy samspiller med andre stressfaktorer, landskapsutforming og urbanisering.
Forfattere
Victoria Stornes MoenSammendrag
Ålegrasenger er svært artsrike økosystemer som er i sterk tilbakegang. På grunn av dette har det blitt et økende fokus på å utvikle restaureringsteknikker som inkluderer planting/spredning og oppformeringsarbeid av ålegras. Tradisjonelt var det hovedsakelig dykkere som utførte dette arbeidet, noe som gjør det svært kostbart og økonomisk utfordrende å restaurere ålegrasenger i stor skala. Naturvernforbundet i Østfold ønsket derfor å utføre en litteraturstudie for å finne metoder og resultater fra forsøk på oppformering og planting/ spredning av ålegras uten behov for dykkere. Vår litteraturstudie viser at det er beskrevet flere plante- og spredningsteknikker som har gitt gode restaureringsresultater. Det kan lønne seg å bruke en kombinasjon av ulike teknikker i samme eng da ulike sprednings- og planteteknikker kan være fordelaktige i ulike dybder av enga og under ulike hydrodynamiske forhold. Oppformering av ålegras i akvakultursystemer er en relativt ny metode og det finnes få publiserte studier på dette. Det presenteres imidlertid en svært lovende metodikk som viste at kultiverte ålegrasplanter hadde høyere grad av overlevelse, høyere skudd og større grad av vegetativ reproduksjon enn ålegrasplanter som ble transplantert fra naturlige enger.
Forfattere
Arne BardalenSammendrag
Det er ikke registrert sammendrag
Forfattere
Juliana D. Klein Simo Maduna Matthew L. Dicken Charlene Da Silva Michelle Soekoe Meaghen E. McCord Warren M. Potts Snorre Hagen Aletta E Bester-van der MerweSammendrag
Adaptive divergence in response to environmental clines are expected to be common in species occupying heterogeneous environments. Despite numerous advances in techniques appropriate for non-model species, gene–environment association studies in elasmobranchs are still scarce. The bronze whaler or copper shark (Carcharhinus brachyurus) is a large coastal shark with a wide distribution and one of the most exploited elasmobranchs in southern Africa. Here, we assessed the distribution of neutral and adaptive genomic diversity in C. brachyurus across a highly heterogeneous environment in southern Africa based on genome-wide SNPs obtained through a restriction site-associated DNA method (3RAD). A combination of differentiation-based genome-scan (outflank) and genotype–environment analyses (redundancy analysis, latent factor mixed models) identified a total of 234 differentiation-based outlier and candidate SNPs associated with bioclimatic variables. Analysis of 26,299 putatively neutral SNPs revealed moderate and evenly distributed levels of genomic diversity across sites from the east coast of South Africa to Angola. Multivariate and clustering analyses demonstrated a high degree of gene flow with no significant population structuring among or within ocean basins. In contrast, the putatively adaptive SNPs demonstrated the presence of two clusters and deep divergence between Angola and all other individuals from Namibia and South Africa. These results provide evidence for adaptive divergence in response to a heterogeneous seascape in a large, mobile shark despite high levels of gene flow. These results are expected to inform management strategies and policy at the national and regional level for conservation of C. brachyurus populations.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Subal Chandra Kumbhakar Jingfang Zhang Gudbrand LienSammendrag
In this study, we leverage geographical coordinates and firm-level panel data to uncover variations in production across different locations. Our approach involves using a semiparametric proxy variable regression estimator, which allows us to define and estimate a customized production function for each firm and its corresponding location. By employing kernel methods, we estimate the nonparametric functions that determine the model’s parameters based on latitude and longitude. Furthermore, our model incorporates productivity components that consider various factors that influence production. Unlike spatially autoregressive-type production functions that assume a uniform technology across all locations, our approach estimates technology and productivity at both the firm and location levels, taking into account their specific characteristics. To handle endogenous regressors, we incorporate a proxy variable identification technique, distinguishing our method from geographically weighted semiparametric regressions. To investigate the heterogeneity in production technology and productivity among Norwegian grain farmers, we apply our model to a sample of farms using panel data spanning from 2001 to 2020. Through this analysis, we provide empirical evidence of regional variations in both technology and productivity among Norwegian grain farmers. Finally, we discuss the suitability of our approach for addressing the heterogeneity in this industry.