26 research outputs found
Using GPS telemetry to validate least-cost modeling of gray squirrel ( Sciurus carolinensis) movement within a fragmented landscape
In Britain, the population of native red squirrels Sciurus vulgaris has suffered population declines and local extinctions. Interspecific resource competition and disease spread by the invasive gray squirrel Sciurus carolinensis are the main factors behind the decline. Gray squirrels have adapted to the British landscape so efficiently that they are widely distributed. Knowledge on how gray squirrels are using the landscape matrix and being able to predict their movements will aid management. This study is the first to use global positioning system (GPS) collars on wild gray squirrels to accurately record movements and land cover use within the landscape matrix. This data were used to validate Geographical Information System (GIS) least-cost model predictions of movements and provided much needed information on gray squirrel movement pathways and network use. Buffered least-cost paths and least-cost corridors provide predictions of the most probable movements through the landscape and are seen to perform better than the more expansive least-cost networks which include all possible movements. Applying the knowledge and methodologies gained to current gray squirrel expansion areas, such as Scotland and in Italy, will aid in the prediction of potential movement areas and therefore management of the invasive gray squirrel. The methodologies presented in this study could potentially be used in any landscape and on numerous species
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A method for performance diagnosis and evaluation of video trackers
Several measures for evaluating multi-target video trackers exist that generally aim at providing ‘end performance.’ End performance is important particularly for ranking and comparing trackers. However, for a deeper insight into trackers’ performance it would also be desirable to analyze key contributory factors (false positives, false negatives, ID changes) that (implicitly or explicitly) lead to the attainment of a certain end performance. Specifically, this paper proposes a new approach to enable a diagnosis of the performance of multi-target trackers as well as providing a means to determine the end performance to still enable their comparison in a video sequence. Diagnosis involves analyzing probability density functions of false positives, false negatives and ID changes of trackers in a sequence. End performance is obtained in terms of the extracted performance scores related to false positives, false negatives and ID changes. In the experiments, we used four state-of-the-art trackers on challenging real-world public datasets to show the effectiveness of the proposed approach
Multi-resolution image analysis for vehicle detection
Proceeding of: Second Iberian Conference, IbPRIA 2005, Estoril, Portugal, June 7-9, 2005Computer Vision can provide a great deal of assistance to Intelligent Vehicles. In this paper an Advanced Driver Assistance Systems for Vehicle Detection is presented. A geometric model of the vehicle is defined where its energy function includes information of the shape and symmetry of the vehicle and the shadow it produces. A genetic algorithm finds the optimum parameter values. As the algorithm receives information from a road detection module some geometric restrictions can be applied. A multi-resolution approach is used to speed up the algorithm and work in realtime. Examples of real images are shown to validate the algorithm.Publicad
Characterisation of the Cullin-3 mutation that causes a severe form of familial hypertension and hyperkalaemia
Deletion of exon 9 from Cullin‐3 (CUL3, residues 403–459: CUL3Δ403–459) causes pseudohypoaldosteronism type IIE (PHA2E), a severe form of familial hyperkalaemia and hypertension (FHHt). CUL3 binds the RING protein RBX1 and various substrate adaptors to form Cullin‐RING‐ubiquitin‐ligase complexes. Bound to KLHL3, CUL3‐RBX1 ubiquitylates WNK kinases, promoting their ubiquitin‐mediated proteasomal degradation. Since WNK kinases activate Na/Cl co‐transporters to promote salt retention, CUL3 regulates blood pressure. Mutations in both KLHL3 and WNK kinases cause PHA2 by disrupting Cullin‐RING‐ligase formation. We report here that the PHA2E mutant, CUL3Δ403–459, is severely compromised in its ability to ubiquitylate WNKs, possibly due to altered structural flexibility. Instead, CUL3Δ403–459 auto‐ubiquitylates and loses interaction with two important Cullin regulators: the COP9‐signalosome and CAND1. A novel knock‐in mouse model of CUL3WT/Δ403–459 closely recapitulates the human PHA2E phenotype. These mice also show changes in the arterial pulse waveform, suggesting a vascular contribution to their hypertension not reported in previous FHHt models. These findings may explain the severity of the FHHt phenotype caused by CUL3 mutations compared to those reported in KLHL3 or WNK kinases
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Application of the risk-based strategy to the Hanford tank waste organic-nitrate safety issue
This report describes the results from application of the Risk-Based Decision Management Approach for Justifying Characterization of Hanford Tank Waste to the organic-nitrate safety issue in Hanford single-shell tanks (SSTs). Existing chemical and physical models were used, taking advantage of the most current (mid-1997) sampling and analysis data. The purpose of this study is to make specific recommendations for planning characterization to help ensure the safety of each SST as it relates to the organic-nitrate safety issue. An additional objective is to demonstrate the viability of the Risk-Based Strategy for addressing Hanford tank waste safety issues
Characterisation of the Cullin-3 mutation that causes a severe form of familial hypertension and hyperkalaemia
This is the final version of the article. Available from the publisher via the DOI in this record.Deletion of exon 9 from Cullin‐3 (CUL3, residues 403–459: CUL3Δ403–459) causes pseudohypoaldosteronism type IIE (PHA2E), a severe form of familial hyperkalaemia and hypertension (FHHt). CUL3 binds the RING protein RBX1 and various substrate adaptors to form Cullin‐RING‐ubiquitin‐ligase complexes. Bound to KLHL3, CUL3‐RBX1 ubiquitylates WNK kinases, promoting their ubiquitin‐mediated proteasomal degradation. Since WNK kinases activate Na/Cl co‐transporters to promote salt retention, CUL3 regulates blood pressure. Mutations in both KLHL3 and WNK kinases cause PHA2 by disrupting Cullin‐RING‐ligase formation. We report here that the PHA2E mutant, CUL3Δ403–459, is severely compromised in its ability to ubiquitylate WNKs, possibly due to altered structural flexibility. Instead, CUL3Δ403–459 auto‐ubiquitylates and loses interaction with two important Cullin regulators: the COP9‐signalosome and CAND1. A novel knock‐in mouse model of CUL3WT/Δ403–459 closely recapitulates the human PHA2E phenotype. These mice also show changes in the arterial pulse waveform, suggesting a vascular contribution to their hypertension not reported in previous FHHt models. These findings may explain the severity of the FHHt phenotype caused by CUL3 mutations compared to those reported in KLHL3 or WNK kinases.This work was supported by the British Heart Foundation (a PhD studentship
to KS and PG 13 89 30577), Medical Research Council, and an ERC Starting
Investigator Grant (to TK), as well as the pharmaceutical companies supporting
the Division of Signal Transduction Therapy Unit (AstraZeneca, Boehringer
Ingelheim, GlaxoSmithKline, Merck, Janssen Pharmaceutica and Pfizer). The
Human Research Tissue Bank is supported by the NIHR Cambridge Biomedical
Research Centre
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APMS SVD methodology and implementation
One of the main tasks within the Aviation Performance Measurement System (APMS) program uses statistical methodologies to find atypical flights. With thousands of flights a day and hundreds of parameters being recorded every second for each flight, the amount of data escalates and the ability to find atypical flights becomes more difficult. The purpose of this paper is to explain the method known as single value decomposition (SVD) employed to search for the atypical flights and display useful graphics that facilitate understanding the causes of atypicality for these flights. Other methods could also perform this search and some are planned for future implementation
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Methodology for uncertainty estimation of Hanford tank chemical and radionuclide inventories and concentrations
The exact physical and chemical nature of 55 million gallons of toxic waste held in 177 underground waste tanks at the Hanford Site is not known with sufficient detail to support the safety, retrieval, and immobilization missions presented to Hanford. The Hanford Best Basis team has made point estimates of the inventories in each tank. The purpose of this study is to estimate probability distributions for each of the 71 analytes and 177 tanks that the Hanford Best Basis team has made point estimates for. This will enable uncertainty intervals to be calculated for the Best Basis inventories and should facilitate the safety, retrieval, and immobilization missions. Section 2 of this document describes the overall approach used to estimate tank inventory uncertainties. Three major components are considered in this approach: chemical concentration, density, and waste volume. Section 2 also describes the two different methods used to evaluate the tank wastes in terms of sludges and in terms of supernatant or saltcakes. Sections 3 and 4 describe in detail the methodology to assess the probability distributions for each of the three components, as well as the data sources for implementation. The conclusions are given in Section 5