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High-density cultivation of terrestrial Nostoc strains leads to reprogramming of secondary metabolome
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-09-22)
Terrestrial symbiotic cyanobacteria of the genus <i>Nostoc</i> exhibit a large potential for the production of bioactive natural products of the nonribosomal peptide, polyketide, and ribosomal peptide classes, and yet most of the biosynthetic gene clusters are silent under conventional cultivation conditions. In the present study, we utilized a high-density cultivation approach recently developed ...
Eukaryotic microbial richness increases with latitude and decreasing temperature in the Pacific Subarctic domain in late winter
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06-06)
The Bering Sea has some of the highest concentrations of inorganic nutrients of any marine system. In the Bering Sea, eukaryotic microbes interface inorganic nutrient sequestration and cycling processes that drive one of the most productive ecosystems globally. Historical surveys of eukaryotic microbial diversity in the Bering Sea have relied on microscopy and culturing-dependent analyses to assess ...
A framework for categorizing social media posts
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-03-10)
Abstract: Brand posts are concise and recurrent updates created by brands and
sent out to their followers on social media. Brand posts play a crucial linking role by
connecting brands to their customers and fans on a daily basis. Brand posts represent
a rich form of communication that convey various brand meaning and experiences
using multiple media formats. Despite this, however, brand posts ...
Transitions of social-ecological subsistence systems in the Arctic
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-04)
Transitions of social-ecological systems (SES) expose governance systems
to new challenges. This is particularly so in the Arctic where resource systems
are increasingly subjected to global warming, industrial development and globalization
which subsequently alter the local SES dynamics. Based on common-pool
resource theory, we developed a dynamic conceptual model explaining how exogenous
drivers ...
Arctic greening from warming promotes declines in caribou populations
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-26)
The migratory tundra caribou herds in North America follow decadal population cycles, and browsing from abundant
caribou could be expected to counteract the current climate-driven expansion of shrubs in the circumpolar tundra
biome. We demonstrate that the sea ice cover in the Arctic Ocean has provided a strong signal for climate-induced
changes on the adjacent caribou summer ranges, outperforming ...
A Novel Brominated Alkaloid Securidine A, Isolated from the Marine Bryozoan Securiflustra securifrons
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-07-23)
A novel brominated alkaloid, Securidine A, was isolated from the cold water marine bryozoan Securiflustra securifrons. Securidine A was isolated using semi-preparative HPLC, and the structure was elucidated by spectroscopic methods. The isolated Securidine A was tested for cytotoxic, antibacterial, and anti-diabetic activities as well as for its potential for inhibition of biofilm formation. No ...
Elevationally biased avian predation as a contributor to the spatial distribution of geometrid moth outbreaks in sub-arctic mountain birch forest
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-04-03)
1. Population dynamics and interactions that vary over a species’ range are
of particular importance in the context of latitudinal clines in biological diversity.Winter
moth (Operophtera brumata) and autumnal moth (Epirrita autumnata) are two species
of eruptive geometrids that vary widely in outbreak tendency over their range, which
generally increases from south to north and with elevation.
2. ...
Upward nitrate flux and downward particulate organic carbon flux under contrasting situations of stratification and turbulent mixing in an Arctic shelf sea
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-08-02)
Increased sea ice melt alters vertical surface-mixing processes in Arctic seas. More melt water strengthens the stratification, but an absent ice cover also exposes the uppermost part of the water column to wind-induced mixing processes. We conducted a field study in the Barents Sea, an Arctic shelf sea, to examine the effects of stratification and vertical mixing processes on 1) the upward nitrate ...
Turbulent heat and momentum fluxes in the upper ocean under Arctic sea ice
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-02-25)
We report observations of heat and momentum fluxes measured in the ice-ocean boundary layer from four drift stations between January and June 2015, covering from the typical Arctic basin conditions in the Nansen Basin to energetic spots of interaction with the warm Atlantic Water branches near the Yermak Plateau and over the North Spitsbergen slope. A wide range of oceanic turbulent heat flux values ...
Carbon, Nitrogen and Sulphur isotopic fractionation in captive juvenile hooded seal (Cystophora cristata): application for diet analysis
(Journal article; Tidsskriftartikkel; Peer reviewed, 2017-08-15)
<p><i>Rationale</i>: Intrinsic biogeochemical markers, such as stable isotope ratios of carbon, nitrogen and sulphur, are increasingly used to trace the trophic ecology of marine top predators. However, insufficient knowledge of fractionation processes in tissues continues to hamper the use of these markers.</p>
<p><i>Methods</i>: We performed a controlled feeding experiment with eight juvenile ...