810 research outputs found
Application of the Fisher-Rao metric to ellipse detection
The parameter space for the ellipses in a two dimensional image is a five dimensional manifold, where each point of the manifold corresponds to an ellipse in the image. The parameter space becomes a Riemannian manifold under a Fisher-Rao metric, which is derived from a Gaussian model for the blurring of ellipses in the image. Two points in the parameter space are close together under the Fisher-Rao metric if the corresponding ellipses are close together in the image. The Fisher-Rao metric is accurately approximated by a simpler metric under the assumption that the blurring is small compared with the sizes of the ellipses under consideration. It is shown that the parameter space for the ellipses in the image has a finite volume under the approximation to the Fisher-Rao metric. As a consequence the parameter space can be replaced, for the purpose of ellipse detection, by a finite set of points sampled from it. An efficient algorithm for sampling the parameter space is described. The algorithm uses the fact that the approximating metric is flat, and therefore locally Euclidean, on each three dimensional family of ellipses with a fixed orientation and a fixed eccentricity. Once the sample points have been obtained, ellipses are detected in a given image by checking each sample point in turn to see if the corresponding ellipse is supported by the nearby image pixel values. The resulting algorithm for ellipse detection is implemented. A multiresolution version of the algorithm is also implemented. The experimental results suggest that ellipses can be reliably detected in a given low resolution image and that the number of false detections
can be reduced using the multiresolution algorithm
Development of Single-station Early Warning Lightning Alarm System
Lightning is one of the spectacular natural phenomena which happen on the earth. More than 2000 people are killed worldwide by lightning each year. The lightning monitoring system is important as the early warning alarm system. In this paper,lightning warning alarm system which can
monitor and observe the lightning activity has been discussed. The system able to trigger the warning alarm whenever a lightning strikes at a particular area in 10 km radius from UMP Pekan, Pahang, Malaysia. The LabVIEW software was used as a data logger to measure, analyze and calculate the lightning distance. The accuracy of the system has been compared and validated by the Pekan Lightning Detection System (PLDS)
Identification of Recurrent Mutations in the microRNA-Binding Sites of B-Cell Lymphoma-Associated Genes in Follicular Lymphoma
Follicular lymphoma (FL) is a common indolent B-cell lymphoma that can transform into the more aggressive transformed FL (tFL). However, the molecular process driving this transformation is uncertain. In this work, we aimed to identify microRNA (miRNA)-binding sites recurrently mutated in follicular lymphoma patients, as well as in transformed FL patients. Using whole-genome sequencing data from FL tumors, we discovered 544 mutations located in bioinformatically predicted microRNA-binding sites. We then studied these specific regions using targeted sequencing in a cohort of 55 FL patients, found 16 recurrent mutations, and identified a further 69 variants. After filtering for QC, we identified 21 genes with mutated miRNA-binding sites that were also enriched for B-cell-associated genes by Gene Ontology. Over 40% of mutations identified in these genes were present exclusively in tFL patients. We validated the predicted miRNA-binding sites of five of the genes by luciferase assay and demonstrated that the identified mutations in BCL2 and EZH2 genes impaired the binding efficiency of miR-5008 and miR-144 and regulated the endogenous levels of messenger RNA (mRNA)
Children’s play and independent mobility in 2020: results from the British Children’s Play Survey
The British Children’s Play Survey was conducted in April 2020 with a nationally representative sample of 1919 parents/caregivers with a child aged 5–11 years. Respondents completed a range of measures focused on children’s play, independent mobility and adult tolerance of and attitudes towards risk in play. The results show that, averaged across the year, children play for around 3 h per day, with around half of children’s play happening outdoors. Away from home, the most common places for children to play are playgrounds and green spaces. The most adventurous places for play were green spaces and indoor play centres. A significant difference was found between the age that children were reported to be allowed out alone (10.74 years; SD = 2.20 years) and the age that their parents/caregivers reported they had been allowed out alone (8.91 years; SD = 2.31 years). A range of socio-demographic factors were associated with children’s play. There was little evidence that geographical location predicted children’s play, but it was more important for independent mobility. Further, when parents/caregivers had more positive attitudes around children’s risk-taking in play, children spent more time playing and were allowed to be out of the house independently at a younger age
New results on GP Com
We present high resolution optical and UV spectra of the 46 min orbital
period, helium binary, GP Com. Our data contains simultaneous photometric
correction which confirms the flaring behaviour observed in previous optical
and UV data. In this system all lines show a triple peaked structure where the
outer two peaks are associated with the accretion disc around the compact
object. The main aim of this paper is to constrain the origin of the central
peak, also called ``central spike''. We find that the central spike contributes
to the flare spectra indicating that its origin is probably the compact object.
We also detect that the central spike moves with orbital phase following an
S-wave pattern. The radial velocity semiamplitude of the S-wave is ~10 km/s
indicating that its origin is near the centre of mass of the system, which in
this case lies very close to the white dwarf. Our resolution is higher than
that of previous data which allows us to resolve structure in the central peak
of the line. The central spike in three of the HeI lines shows another peak
blueshifted with respect to the main peak. We propose that one of the peaks is
a neutral helium forbidden transition excited in a high electron density
region. This forbidden transition is associated with the permitted one (the
stronger peak in two of the lines). The presence of a high electron density
region again favours the white dwarf as their origin.Comment: 14 pages, 16 figures. Accepted for publication in A&
Identification of Recurrent Mutations in the microRNA-Binding Sites of B-Cell Lymphoma-Associated Genes in Follicular Lymphoma
Follicular lymphoma (FL) is a common indolent B-cell lymphoma that can transform into the more aggressive transformed FL (tFL). However, the molecular process driving this transformation is uncertain. In this work, we aimed to identify microRNA (miRNA)-binding sites recurrently mutated in follicular lymphoma patients, as well as in transformed FL patients. Using whole-genome sequencing data from FL tumors, we discovered 544 mutations located in bioinformatically predicted microRNA-binding sites. We then studied these specific regions using targeted sequencing in a cohort of 55 FL patients, found 16 recurrent mutations, and identified a further 69 variants. After filtering for QC, we identified 21 genes with mutated miRNA-binding sites that were also enriched for B-cell-associated genes by Gene Ontology. Over 40% of mutations identified in these genes were present exclusively in tFL patients. We validated the predicted miRNA-binding sites of five of the genes by luciferase assay and demonstrated that the identified mutations in BCL2 and EZH2 genes impaired the binding efficiency of miR-5008 and miR-144 and regulated the endogenous levels of messenger RNA (mRNA)
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