Reinert Korsnes

Korsnes Biocomputing (KoBio)

Fracturing and refreezing of sea ice in the Kara sea are investigated using complex network analysis. By going to the dual network, where the fractures are nodes and their intersections links, we gain access to topological features which are easy to measure and hence compare with modeled networks. Resulting network reveal statistical properties of...

Long-term video-based tracking of single A549 lung cancer cells exposed to three different concentrations of the marine toxin yessotoxin (YTX) reveals significant variation in cytotoxicity, and it confirms the potential genotoxic effects of this toxin. Tracking of single cells subject to various toxic exposure, constitutes a conceptually simple app...

Single-cell tracking throughout several cell cycles allows to trace kinships of cells in lineage trees and find correlations among phenotypes. It allows to utilize the fact that related cells bear information on the underlying mechanisms behind single cell phenotypes. Combined or contextual analyses can therefore help to extract more information fr...

Background Video recording of cells offers a straightforward way to gain valuable information from their response to treatments. An indispensable step in obtaining such information involves tracking individual cells from the recorded data. A subsequent step is reducing such data to represent essential biological information. This can help to compar...

Cancer cell clustering is a critical factor in metastasis, with cells often believed to migrate in groups as they establish themselves in new environments. This study presents preliminary findings from an in vitro experiment, suggesting that co-culturing cells provides an effective method for observing this phenomenon, even though the cells are gro...

The marine toxin yessotoxin (YTX) can cause various cytotoxic effects depending on cell type and cell line. It is well known to trigger distinct mechanisms for programmed cell death which may overlap or cross-talk. The present contribution provides the first evidence that YTX can cause genotoxicity and induce mitotic catastrophe which can lead to d...

An intention for this work is to lay out a case study to explore individual cell tracking as a tool in toxicological research. Individual cell tracking is a developing technology which can potentially provide fast diagnosis of changes in cell populations for example due to toxic insults. It can also help to guide hypothesis formulation in pilot stu...

This contribution demonstrates an example of experimental automatic image analysis to detect spores prepared on microscope slides derived from trapping. The application is to monitor aerial spore counts of the entomopathogenic fungus Pandora neoaphidis which may serve as a biological control agent for aphids. Automatic detection of such spores can...

The marine toxin yessotoxin (YTX) can induce programmed cell death through both caspase-dependent and -independent pathways in various cellular systems. It appears to stimulate different forms of cellular stress causing instability among cell death mechanisms and making them overlap and cross-talk. Autophagy is one of the key pathways that can be s...

This work shows examples of lifetime distributions for individual BC3H1 cells after start of exposure to the marine toxin yessotoxin (YTX) in an experimental dish. The present tracking of many single cells from time-lapse microscopy data demonstrates the complexity in individual cell fate and which can be masked in aggregate properties. This contri...

We propose evolutionary computation to estimate positions of nodes within a sensor network. The approach uses signal strength measurements between nodes and given positions for a subset of these nodes (anchor nodes). The signal strength measurements and routing requests take place simultaneously. A data collecting unit (sink node) receives distance...

This work illustrates potentials for recognition within {\em ad hoc} sensor networks if their nodes possess individual inter-related biologically inspired genetic codes. The work takes ideas from natural immune systems protecting organisms from infection. Nodes in the present proposal have individual gene sets fitting into a self organised phylogen...

This work shows potentials for rapid self-organisation of sensor networks where nodes collaborate to relay messages to a common data collecting unit (sink node). The study problem is, in the sense of graph theory, to find a shortest path tree spanning a weighted graph. This is a well-studied problem where for example Dijkstra's algorithm provides a...

The results of laboratory experiments performed with a prototype of a measuring device intended for monitoring the thickness and drift velocity of ice in Arctic seas are presented. This device is a system of hydrostatic-pressure sensors located inside a hollow flexible tube. Owing to the positive buoyancy, the system of sensors is pressed to the bo...

Routing appears to be the most well studied aspect in ad hoc networking. However, existing routing protocols usually do not take link lifetime into account for route establishment or maintenance. In this paper, assuming that nodes are moving independently in a mobile ad hoc network, we first illustrate that the expected remaining link lifetime incr...

1] Frequencies of observed occurrences of shore-fast ice in the northeastern Kara Sea for each month during 1953–1990 reveal a multimodality of shore-fast ice extent in late winter and spring. The fast ice extent exhibits mainly three different configurations (modes) associated with the regional topography of coasts and islands. These modes show fa...

Military commanders require timely and accurate understanding of the situation in their respective area of responsibility as well as a prediction of the likely intentions and capabilities of supposed or potential adversaries. To achieve this, intelligence cells have to process and evaluate information from all kinds of sources. Particularly in the...

The present study of temporal and spatial variations of shore-fast ice in the Kara Sea includes utilization of aircraft observations by the Arctic and Antarctic Research Institute (AARI) from 1953 to 1990, and surface brightness temperature from SSM/I from 1987 to 2001. Analyses of a time series of spatially distributed SSM/I brightness temperature...

Using satellite ice drift and ice concentration data, observed sea surface temperature and sea level pressure data we have developed a statistical sea ice model (ISMO) and computed the vectors of ice velocity for the period 1899–2000 and ice concentration for the period 1966–2000. On the basis of the ISMO results, we estimate the sea ice fluxes thr...

The present study shows by example the potential amount of information available in a set of observations of targets where there are known relations between these targets. Known relations between objects significantly reduces the set of possible explanations behind a set of observations. The application here is classification of military targets. C...

Remote sensing of the ice cover in Storfjorden (Svalbard) revealed the persistence and evolution of latent heat polynyas during the winter of 1997/98. Latent heat polynyas open mechanically under wind stress or ocean currents that transport the ice cover away. In the present work we used mathematical modelling to simulate the Storfjorden polynya si...

Remote sensing of the ice cover in Storfjorden (Svalbard) revealed the persistence and evolution of latent heat polynyas during the winter of 1997/98. Latent heat polynyas open mechanically under wind stress or ocean currents that transport the ice cover away. In the present work we used mathematical modelling to simulate the Storfjorden polynya si...

Sea ice breaks up and regenerates rapidly during winter conditions in the Arctic. Analyzing satellite data from the Kara Sea, we find that the average ice floe size depends on weather conditions. Nevertheless, the frequency of floes of size A is a power law, N∼A−τ, where τ=1.6±0.2, for A less than approximately . This scale-invariant behavior sugge...

This work investigates the temporal and spatial variation of shore-fast ice extent in the north-eastern part of the Kara Sea during 1953-1990 and its sensitivity to interannual variability of the regional climate. The area of fast ice in spring months shows a bimodal distribution. This indicates the existence of two different regimes of fast ice fo...

This work investigates the temporal and spatial variation of shore-fast ice extent in the north-eastern part of the Kara Sea during 1953–1990 and its sensitivity to interannual variability of the regional climate. The area of fast ice in spring months shows a bimodal distribution. This indicates the existence of two different regimes of fast ice fo...

Remote sensing observations of Storfjorden ice cover described the persistence and evolution of latent heat polynyas during winter 1997/1998. The induced important ice production was quantitatively estimated by simple modeling of the sea ice dynamics and growth. In the present work we used mathematical modeling to qualitatively simulate the polynya...

The present estimates of ice drift in the Arctic include utilization of satellite imagery data (special sensor microwave/imager) and a reconstruction of air pressure for the period 1899-1998. A significant part of the sea ice in the Arctic Ocean has its origin in the Kara Sea and melts in the Greenland and the Barents Sea (BS). Consequently there m...

The mechanical stresses caused by wind and ocean currents play an important role in ice cover break up. In our work we focus on the fast (attached to a shore) ice development in the Kara and Laptev Sea basins. During winter, these areas are partly covered by ice, whose destruction and development is subjected to strong offshore winds. The geomechan...

Field measurements during the Barex-95 expedition in the marginal ice zone of the Barents Sea provided new data of solar radiation under different conditions of cloudiness and sea ice cover during the thawing. We found a strong dependence of angular and spectral redistribution of radiation on cloud optical thickness and surface albedo. We developed...

The main physical and ecological processes associated with the summer melt period in the marginal ice zone (MIZ) were investigated in a multidisciplinary research programme (ICE-BAR), which was carried out in the northern Barents Sea during June–August 1995–1996. This study provided simultaneous observations of a wide range of physical and chemical...

Arctic ice amphipods are part of the sympagic macrofauna in the Marginal Ice Zone of the northern Barents Sea and represent an important link from lower to higher trophic levels in some Arctic marine food chains. The species diversity in this area (1995/1996) consisted of four species: Gammarus wilkitzkii, Apherusa glacialis, Onisimus nanseni and O...

Large temporary rigid areas in the Arctic sea ice cover form and disintegrate in a few days during winter. When these rigid areas are shore-fast, they eliminate moment flux from air to water via wind forcing on the ice. Temporary shore-fast ice causes mixing of upper stratified waters below the ice in areas of strong tidal currents. Satellite data...

This paper describes concepts for an algorithm using pairs of satellite SAR imagery to estimate precisely rigid areas and deformations in polar ice fields. The idea is first to produce a sparse sampling of the ice displacement and then identify rigid subsets of this sparse sampling. The algorithm tunes the position parameters of the images using th...

A time series of ERS-1 SAR images is used to estimate ice drift in the Fram Strait January-March 1992 (the ERS-1 mission first ice phase). The images all cover the same area. The sampling interval is three days. The paper shows examples of estimation of ice drift and divergence from this image time series. Divergence is an important quantity in ord...

A time series of ERS-1 SAR images is used to estimate ice drift in the Fram Strait January-March 1992 (the ERS-1 mission first ice phase). The images all cover the same area. The sampling interval is three days. The paper shows examples of estimation of ice drift and divergence from this image time series. Divergence is an important quantity in ord...

This study concentrates on simple concepts for the mathematical modelling of the probability of an iceberg hitting a fixed offshore structure in regions like the Northern Barents Sea. It illustrates the sensitivity of the estimate to various physical assumptions. The study indicates that the iceberg collision risks for fixed offshore structures are...

This paper discusses basic mathematical formulations to clarify the problem of automatic segmentation of sea-ice remote sensing imagery. The work is illustrated with a SAR image. The main issue is a robust and automatic analysis of sea-ice conditions from remotely sensed data. The paper reveals some of the potential and essential features that are...

Mathematical morphology seems to provide a consistent framework for an automatic analysis and description of sea ice geometry that is accessible from remote sensing imagery. This paper reviews basic concepts of the actual theory used and illustrates it by several examples based on a digitized video image, a digitized aerial photograph and a SPOT im...

The SIZEX 91 field experiment, which was the first sea ice validation experiment for ERS-1 SAR data, was carried out in the Barents and Greenland seas in August 1991. This report presents in situ measurements of temperature and conductivity as well as visual observations of different ice types obtained during the Norwegian Polar Institute's cruise...

This study shows that iceberg collision-risks for fixed offshore structures in the Arctic are often heavily underestimated at present. The study concentrates on concepts for the mathematical modelling of the probability of an iceberg hitting a fixed offshore structure in the Arctic. Simple and verifiable assumptions provide extensive statements of...

Routing appears tobethemostwellstudied aspect inad hocnetworking. However, existing routing protocols usually donottake link lifetime into account forroute establishment ormaintenance. Inthis paper, assuming thatnodesare moving independently inamobile adhocnetwork, wefirst illustrate that theexpected remaining link lifetime increases withalready el...