Fakultet for naturvitenskap og teknologi: Nye registreringer
Viser treff 4361-4380 av 5442
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Middle to late Holocene paleoproductivity reconstructions for the western Barents Sea: a model-data comparison
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-30)In this study we focus on late Holocene primary productivity (PP) variability in the western Barents Sea and its response to variable sea ice coverage by combining PP reconstructed from several sediment cores with regional PP trends simulated with a well-constrained organic facies model, OF-Mod 3D. We find that modern production rates reconstructed from buried marine organic matter ... -
Eastward-expanding auroral surges observed in the post-midnight sector during a multiple-onset substorm
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-09)We present three eastward-expanding auroral surge (EEAS) events that were observed intermittently at intervals of about 15 min in the post-midnight sector (01:55–02:40 MLT) by all-sky imagers and magnetometers in northern Europe. It was deduced that each surge occurred just after each onset of a multiple-onset substorm, which was small-scale and did not clearly expand westward, because they were ... -
The science case for the EISCAT_3D radar
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-07-29)The EISCAT (European Incoherent SCATer) Scientific Association has provided versatile incoherent scatter (IS) radar facilities on the mainland of northern Scandinavia (the EISCAT UHF and VHF radar systems) and on Svalbard (the electronically scanning radar ESR (EISCAT Svalbard Radar) for studies of the high-latitude ionised upper atmosphere (the ionosphere). The mainland radars were constructed ... -
Polarimetric SAR Change Detection with the Complex Hotelling-Lawley Trace Statistic
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-03-15)In this paper, we propose a new test statistic for unsupervised change detection in polarimetric radar images. We work with multilook complex covariance matrix data, whose underlying model is assumed to be the scaled complex Wishart distribution. We use the complex-kind Hotelling-Lawley trace statistic for measuring the similarity of two covariance matrices. The distribution of the Hotelling-Lawley ... -
The environment-induced cracking of as-annealed Ni3(Si,Ti) and Ni3(Si,Ti) with 2Mo in sodium chloride solutions
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-08-01)Background The environment-induced cracking (EIC) of as-annealed Ni3(Si,Ti) and Ni3(Si,Ti) with 2Mo has been researched as functions of applied stress, chloride ion concentration, test temperature, and pH. Methods The investigation of EIC was carried out by applying a constant method in NaCl solutions. Results The EIC susceptibility of both intermetallic compounds increased with ... -
Stem cell regulation: Implications when differentiated cells regulate symmetric stem cell division
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-05-19)We use a mathematical model to show that if symmetric stem cell division is regulated by differentiated cells, then changes in the population dynamics of the differentiated cells can lead to changes in the population dynamics of the stem cells. More precisely, the relative fitness of the stem cells can be affected by modifying the death rate of the differentiated cells. This result is interesting ... -
Evaluating Visual Saliency Algorithms: Past, Present and Future
(Tidsskriftartikkel; Journal article; Peer reviewed, 2015-09-01)With the introduction of compressed sensing (CS) theory, investigation into exploiting sparseness and optimizing compressive sensing performance has ensued. Compressed sensing is highly applicable to images, which naturally have sparse representations. Improvements in the area of image denoising have resulted from the combination of highly-directional transforms with shrinkage and thresholding ... -
Psoriasis pathogenesis – Pso p27 constitutes a compact structure forming large aggregates
(Journal article; Tidsskriftartikkel, 2015-07)Psoriasis is a chronic inflammatory skin disease. The absence of microbial organisms as potential causal agents has given rise to the hypothesis that the inflammation is due to an autoimmune reaction. The defined inflamed areas of the skin lesions argue for an immunological disease with a local production of a causal antigen. Pso p27 is a protein generated in mast cells in psoriatic plaques, but ... -
On the Application of Bio-Inspired Optimization Algorithms to Fuzzy C-Means Clustering of Time Series
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015)Fuzzy c-means clustering (FCM) is a clustering method which is based on the partial membership concept. As with the other clustering methods, FCM applies a distance to cluster the data. While the Euclidean distance is widely-used to perform the clustering task, other distances have been suggested in the literature. In this paper we study the use of a weighted combination of metrics in FCM clustering ... -
Five-Photon Absorption and Selective Enhancement of Multiphoton Absorption Processes
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-05-12)We study one-, two-, three-, four- and five-photon absorption of three centrosymmetric molecules using density functional theory. These calculations are the first ab initio calculations of five-photon absorption. Even- and odd-order absorption processes show different trends in the absorption cross sections. The behaviour of all even-and odd-photon absorption properties shows a semi-quantitative ... -
Chemo-inspired Genetic Algorithm for Optimizing the Piecewise Aggregate Approximation
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015)In a previous work we presented DEWPAA: an improved version of the piecewise aggregate approximation representation method of time series. DEWPAA uses differential evolution to set weights to different segments of the time series according to their information content. In this paper we use a hybrid of bacterial foraging and genetic algorithm (CGA) to set the weights of the different segments in our ... -
Screening of variable importance for optimizing electrodialytic remediation of heavy metals from polluted harbour sediments
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-04-15)Using multivariate design and modelling, optimal conditions for electrodialytic remediation (EDR) of heavy metals were determined for polluted harbour sediments from Hammerfest harbour located in the geographic Arctic region of Norway. The comparative importance of the variables; current density, remediation time, light/no light, the liquid-solid ratio and stirring rate of the sediment suspension ... -
Recombinant expression and purification of an ATP-dependent DNA ligase from Aliivibrio salmonicida
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014-05)The genome of the psychrophilic fish-pathogen Aliivibrio salmonicida encodes a putative ATP-dependent DNA ligase in addition to a housekeeping NAD-dependent enzyme. In order to study the structure and activity of the ATP dependent ligase in vitro we have undertaken its recombinant production and purification from an Escherichia coli based expression system. Expression and purification of this ... -
Lessons learned from 25 years with telemedicine in Northern Norway
(Book; Bok, 2015) -
Marine stewardship and complexity – How to enhance a better process of risk governance in the Norwegian area of the Arctic Ocean?
(Conference object; Konferansebidrag, 2016-01) -
Dørene lukkes for klimamålene
(Journal article; Tidsskriftartikkel, 2016)FNs klimapanel har utarbeidet en rekke prognoser for økningen i global middeltemperatur basert på ulike scenarier for utviklingen av utslipp av drivhusgasser og partikler fra menneskelig aktivitet. Disse prognosene er i hovedsak basert på en lang rekke svært komplekse modeller. De mest komplekse, såkalte jordsystemmodeller, omfatter sirkulasjonen i atmosfære og hav, men også isdynamikk, og kjemiske ... -
The Spot 42 RNA: A regulatory small RNA with roles in the central metabolism
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-09-01)The Spot 42 RNA is a 109 nucleotide long (in Escherichia coli) noncoding small regulatory RNA (sRNA) encoded by the spf (spot fourty-two) gene. spf is found in gamma-proteobacteria and the majority of experimental work on Spot 42 RNA has been performed using E. coli, and recently Aliivibrio salmonicida. In the cell Spot 42 RNA plays essential roles as a regulator in carbohydrate metabolism and uptake, ... -
Appendix E Telemedisinske løsninger i maritime operasjoner og redningstjeneste
(Research report; Forskningsrapport, 2016)Folk som jobber i maritime miljø har ikke enkel tilgang til sentrale helsetjenester, og det gjelder spesielt for sjøfolk som arbeider i arktiske områder. Selv om telemedisin har vært en suksess på land, har telemedisin kun i begrenset grad blitt tatt i bruk til havs. Dette skyldes blant annet fravær av gode kommunikasjonsløsninger, dårlige værforhold, store avstander og lange perioder utenfor ... -
A Haar Wavelet-based Multi-resolution Representation Method of Time Series Data
(Peer reviewed; Journal article; Tidsskriftartikkel, 2015-01-10)Similarity search of time series can be efficiently handled through a multi-resolution representation scheme which offers the possibility to use pre-computed distances that are calculated and stored at indexing time and then utilized at query time together with filters in the form of exclusion conditions which speed up the search. In this paper we introduce a new multi-resolution representation ... -
Chip-based optical microscopy for imaging membrane sieve plates of liver scavenger cells
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-08-26)The evanescent field on top of optical waveguides is used to image membrane network and sieve-plates of liver endothelial cells. In waveguide excitation, the evanescent field is dominant only near the surface (~100-150 nm) providing a default optical sectioning by illuminating fluorophores in close proximity to the surface and thus benefiting higher signal-to-noise ratio. The sieve plates of liver ...