47 research outputs found
Contour dynamics for vortex-induced advection
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Two truncating variants in FANCC and breast cancer risk
Fanconi anemia (FA) is a genetically heterogeneous disorder with 22 disease-causing genes reported to date. In some FA genes, monoallelic mutations have been found to be associated with breast cancer risk, while the risk associations of others remain unknown. The gene for FA type C, FANCC, has been proposed as a breast cancer susceptibility gene based on epidemiological and sequencing studies. We used the Oncoarray project to genotype two truncating FANCC variants (p.R185X and p.R548X) in 64,760 breast cancer cases and 49,793 controls of European descent. FANCC mutations were observed in 25 cases (14 with p.R185X, 11 with p.R548X) and 26 controls (18 with p.R185X, 8 with p.R548X). There was no evidence of an association with the risk of breast cancer, neither overall (odds ratio 0.77, 95% CI 0.44-1.33, p = 0.4) nor by histology, hormone receptor status, age or family history. We conclude that the breast cancer risk association of these two FANCC variants, if any, is much smaller than for BRCA1, BRCA2 or PALB2 mutations. If this applies to all truncating variants in FANCC it would suggest there are differences between FA genes in their roles on breast cancer risk and demonstrates the merit of large consortia for clarifying risk associations of rare variants.Peer reviewe
Satellite retrieved aerosol properties for battlespace characterization and sensor performance
Sea basing operations in coastal environments require a rapid and accurate description of the physical conditions in the region. Battlespace characterization and sensor performance assist in optimizing the efficiency and safety of operations, of which the detection of targets at low level above the sea surface is all-important. The environmental conditions of the marine boundary layer (MBL) – due to weather and atmospheric effects – change continuously in space and time, which certainly holds for the aerosol make-up. Models have been developed to describe the electrooptical propagation in the boundary layer as a function of meteorological parameters. EOSTAR is such an end-toend model suite for EO sensor performance in which the Advanced Navy Aerosol Model (ANAM) is embedded for computing the aerosol extinction. While ANAM provides favourable results in open ocean conditions, in coastal zones the model lacks accuracy due to the presence of aerosols from a variety of sources that need to be assessed. In offshore wind conditions continental aerosols of anthropogenic and natural origin mix with marine aerosols produced in the surf zone and by wave breaking further offshore. Radiometers on satellites can be used to retrieve the spatial variation over an extended area determined by the swath width, with a resolution determined by the radiometer pixel size. In this contribution we explore the potential of satellite measurements to provide information on the aerosol properties over the range of interest in order to correctly handle their influence on transmission characteristics in the coastal zone. Results from measurements of the multidisciplinary Maritime REA/Battlespace Preparation 2007 trial, held during 20 April and 5 May 2007 near the vicinity of the island Elba along the west coast of Italy, are presented in this analysis. For one particular day, the satellite retrieved aerosol optical thickness (AOT) is to be compared with hand-held sun photometer measurements for quality assessment. The AOT values are converted into aerosol extinction coefficients for a pre-defined path. For one visible wavelength channel the transmission loss is computed with these coefficients and is compared with the computed transmission loss for the path in case of a) a single extinction coefficient obtained from measurements and b) a modeled extinction coefficient obtained from ANAM
Aerosol optical depth over Europe -Retrieval from ATSR-2 data for the year 2000
Aerosol properties are retrieved from ATSR-2 data (ERS-2 satellite) by utilizing the dual view for application over land and the single view for application over water. These two algorithms have been merged into a fast and efficient algorithm that allows for near real-time processing and which is suitable for operational use. It includes corrections for surface and atmospheric effects including fully automated cloud screening procedures. The algorithm can be applied to retrieve aerosol optical depth (AOD), Ångström parameter and aerosol types. The application to data for the year 2000 over Europe is presented. The retrieved AOD over land compares favorably with collocated sun-photometer data from the Aerosol Robotic Network (AERONET)
Evaluation tools for the effectiveness of infrared countermeasures and signature reduction for ships
The protection of ships against infrared guided missiles is a concern for modern naval forces. The vulnerability of ships can be reduced by applying countermeasures such as infrared decoys and infrared signature reduction. This paper will present a set of simulation tools which can be used for assessing the effectiveness of these measures. The toolset consists of a chain of models which calculate the infrared signature of a ship (EOSM), generate an infrared image of the ship in a realistic sea and sky background (EOSTAR) and determine the behaviour of an infrared missile seeker against these images and simulate the complete missile fly-out including countermeasure deployment (EWM). All model components will be briefly discussed. Typical simulation runs will be shown. © 2010 Copyright SPIE - The International Society for Optical Engineering
Intelligent route surveillance
Intelligence on abnormal and suspicious behaviour along roads in operational domains is extremely valuable for countering the IED (Improvised Explosive Device) threat. Local sensor networks at strategic spots can gather data for continuous monitoring of daily vehicle activity. Unattended intelligent ground sensor networks use simple sensing nodes, e.g. seismic, magnetic, radar, or acoustic, or combinations of these in one housing. The nodes deliver rudimentary data at any time to be processed with software that filters out the required information. At TNO (Netherlands Organisation for Applied Scientific Research) research has started on how to equip a sensor network with data analysis software to determine whether behaviour is suspicious or not. Furthermore, the nodes should be expendable, if necessary, and be small in size such that they are hard to detect by adversaries. The network should be self-configuring and self-sustaining and should be reliable, efficient, and effective during operational tasks - especially route surveillance - as well as robust in time and space. If data from these networks are combined with data from other remote sensing devices (e.g. UAVs (Unmanned Aerial Vehicles)/aerostats), an even more accurate assessment of the tactical situation is possible. This paper shall focus on the concepts of operation towards a working intelligent route surveillance (IRS) research demonstrator network for monitoring suspicious behaviour in IED sensitive domains
Stability and transport properties of multiple-patch quasi-equilibria
A novel subclass of exact solutions to the Euler equations in two dimensions has been put forward recently [D. Crowdy, "A class of exact multipolar vortices," Phys. Fluids 11, 2556 (1999)]. The solutions show vortical equilibria which can be described by only two parameters. The first one designates the multipolar aspect of these equilibria, i.e., the number of point vortices involved, while the other parameter signatures the shape of the finite area of uniform vorticity in which the point vortices are embedded. The main aspect of these equilibria is that the vortical configuration is static, meaning that the velocity induced at the patch edge, outside the vortical area, and also at the locations of the point vortices is zero. We show with numerical experiments that quite remarkably the linearly stable equilibria of Crowdy seem to mix very efficiently in contrast to the unstable vortex solutions. In the second part of this paper we report on the dynamics, stability, and mixing properties of similar vortex systems where the point vortices are regularized to vortex patches (with uniform vorticity). Several of these multiple-patch vortices turn out to be remarkably stable, although the regularization itself should be considered as a (symmetric) perturbation of Crowdy's multipolar solutions
Segmentation and wake removal of seafaring vessels in optical satellite images
This paper aims at the segmentation of seafaring vessels in optical satellite images, which allows an accurate length estimation. In maritime situation awareness, vessel length is an important parameter to classify a vessel. The proposed segmentation system consists of robust foreground-background separation, wake detection and ship-wake separation, simultaneous position and profile clustering and a special module for small vessel segmentation. We compared our system with a baseline implementation on 53 vessels that were observed with GeoEye-1. The results show that the relative L1 error in the length estimation is reduced from 3.9 to 0.5, which is an improvement of 87%. We learned that the wake removal is an important element for the accurate segmentation and length estimation of ships