76 research outputs found

    Multi-camera analysis of soccer sequences

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    The automatic detection of meaningful phases in a soccer game depends on the accurate localization of players and the ball at each moment. However, the automatic analysis of soccer sequences is a challenging task due to the presence of fast moving multiple objects. For this purpose, we present a multi-camera analysis system that yields the position of the ball and players on a common ground plane. The detection in each camera is based on a code-book algorithm and different features are used to classify the detected blobs. The detection results of each camera are transformed using homography to a virtual top-view of the playing field. Within this virtual top-view we merge trajectory information of the different cameras allowing to refine the found positions. In this paper, we evaluate the system on a public SOCCER dataset and end with a discussion of possible improvements of the dataset

    Immersive video conferencing architecture using game engine technology

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    This paper introduces the use of gaming technology for the creation of immersive video conferencing systems. The system integrates virtual meeting rooms with avatars and life video feeds, shared across different clients. Video analysis is used to create a sense of immersiveness by introducing aspects of the real world in the virtual environment. This architecture will ease and stimulate the development of immersive and intelligent telepresence systems

    Intelligent pre-processing for fast-moving object detection

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    Detection and segmentation of objects of interest in image sequences is the first major processing step in visual surveillance applications. The outcome is used for further processing, such as object tracking, interpretation, and classification of objects and their trajectories. To speed up the algorithms for moving object detection, many applications use techniques such as frame rate reduction. However, temporal consistency is an important feature in the analysis of surveillance video, especially for tracking objects. Another technique is the downscaling of the images before analysis, after which the images are up-sampled to regain the original size. This method, however, increases the effect of false detections. We propose a different pre-processing step in which we use a checkerboard-like mask to decide which pixels to process. For each frame the mask is inverted to avoid that certain pixel positions are never analyzed. In a post-processing step we use spatial interpolation to predict the detection results for the pixels which were not analyzed. To evaluate our system we have combined it with a background subtraction technique based on a mixture of Gaussian models. Results show that the models do not get corrupted by using our mask and we can reduce the processing time with over 45% while achieving similar detection results as the conventional technique

    Severe hepatopathy and neurological deterioration after start of valproate treatment in a 6-year-old child with mitochondrial tryptophanyl-tRNA synthetase deficiency

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    Background: The first subjects with deficiency of mitochondrial tryptophanyl-tRNA synthetase (WARS2) were reported in 2017. Their clinical characteristics can be subdivided into three phenotypes (neonatal phenotype, severe infantile onset phenotype, Parkinson-like phenotype). Results: Here, we report on a subject who presented with early developmental delay, motor weakness and intellectual disability and who was considered during several years as having a non-progressive encephalopathy. At the age of six years, she had an epileptic seizure which was treated with sodium valproate. In the months after treatment was started, she developed acute liver failure and severe progressive encephalopathy. Although valproate was discontinued, she died six months later. Spectrophotometric analysis of the oxidative phosphorylation complexes in liver revealed a deficient activity of complex III and low normal activities of the complexes I and IV. Activity staining in the BN-PAGE gel confirmed the low activities of complex I, III and IV and, in addition, showed the presence of a subcomplex of complex V. Histochemically, a mosaic pattern was seen in hepatocytes after cytochrome c oxidase staining. Using Whole Exome Sequencing two known pathogenic variants were detected in WARS2 (c. 797delC, p. Pro266ArgfsTer10/c. 938 A > T, p. Lys313Met). Conclusion: This is the first report of severe hepatopathy in a subject with WARS2 deficiency. The hepatopathy occurred soon after start of sodium valproate treatment. In the literature, valproate-induced hepatotoxicity was reported in the subjects with pathogenic mutations in POLG and TWNK. This case report illustrates that the course of the disease in the subjects with a mitochondrial defect can be non-progressive during several years. The subject reported here was first diagnosed as having cerebral palsy. Only after a mitochondriotoxic medication was started, the disease became progressive, and the diagnosis of a mitochondrial defect was made

    Format-independent and metadata-driven media resource adaptation using semantic web technologies

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    Adaptation of media resources is an emerging field due to the growing amount of multimedia content on the one hand and an increasing diversity in usage environments on the other hand. Furthermore, to deal with a plethora of coding and metadata formats, format-independent adaptation systems are important. In this paper, we present a new format-independent adaptation system. The proposed adaptation system relies on a model that takes into account the structural metadata, semantic metadata, and scalability information of media bitstreams. The model is implemented using the web ontology language. Existing coding formats are mapped to the structural part of the model, while existing metadata standards can be linked to the semantic part of the model. Our new adaptation technique, which is called RDF-driven content adaptation, is based on executing SPARQL Protocol and RDF Query Language queries over instances of the model for media bitstreams. Using different criteria, RDF-driven content adaptation is compared to other adaptation techniques. Next to real-time execution times, RDF-driven content adaptation provides a high abstraction level for the definition of adaptations and allows a seamless integration with existing semantic metadata standards

    Early-onset primary antibody deficiency resembling common variable immunodeficiency challenges the diagnosis of Wiedeman-Steiner and Roifman syndromes

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    Syndromic primary immunodeficiencies are rare genetic disorders that affect both the immune system and other organ systems. More often, the immune defect is not the major clinical problem and is sometimes only recognized after a diagnosis has been made based on extra-immunological abnormalities. Here, we report two sibling pairs with syndromic primary immunodeficiencies that exceptionally presented with a phenotype resembling early-onset common variable immunodeficiency, while extra-immunological characteristics were not apparent at that time. Additional features not typically associated with common variable immunodeficiency were diagnosed only later, including skeletal and organ anomalies and mild facial dysmorphism. Whole exome sequencing revealed KMT2-Aassociated Wiedemann-Steiner syndrome in one sibling pair and their mother. In the other sibling pair, targeted testing of the known disease gene for Roifman syndrome (RNU4ATAC) provided a definite diagnosis. With this study, we underline the importance of an early-stage and thorough genetic assessment in paediatric patients with a common variable immunodeficiency phenotype, to establish a conclusive diagnosis and guide patient management. In addition, this study extends the mutational and immunophenotypical spectrum of Wiedemann-Steiner and Roifman syndromes and highlights potential directions for future pathophysiological research

    The Odor Specificities of a Subset of Olfactory Receptor Neurons Are Governed by Acj6, a POU-Domain Transcription Factor

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    AbstractLittle is known about how the odor specificities of olfactory neurons are generated, a process essential to olfactory coding. We have found that neuronal identity relies on the abnormal chemosensory jump 6 (acj6) gene, originally identified by a defect in olfactory behavior. Physiological analysis of individual olfactory neurons shows that in acj6 mutants, a subset of neurons acquires a different odorant response profile. Certain other neurons do not respond to any tested odors in acj6. Molecular analysis of acj6 shows that it encodes a POU-domain transcription factor expressed in olfactory neurons. Our data suggest that the odor response spectrum of an olfactory neuron, and perhaps the choice of receptor genes, is determined through a process requiring the action of Acj6

    Phenocopy of a heterozygous carrier of X-linked retinitis pigmentosa due to mosaicism for a RHO variant

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    We describe both phenotype and pathogenesis in two male siblings with typical retinitis pigmentosa (RP) and the potentially X-linked RP (XLRP) carrier phenotype in their mother. Two affected sons, two unaffected daughters, and their mother underwent detailed ophthalmological assessments including Goldmann perimetry, color vision testing, multimodal imaging and ISCEV-standard electroretinography. Genetic testing consisted of targeted next-generation sequencing (NGS) of known XLRP genes and whole exome sequencing (WES) of known inherited retinal disease genes (RetNet-WES). Variant validation and segregation analysis were performed by Sanger sequencing. The mutational load of the RHO variant in the mother was assessed in DNA from leucocytes, buccal cells and hair follicles using targeted NGS. Both affected sons showed signs of classical RP, while the mother displayed patches of hyperautofluorescence on blue light autofluorescence imaging and regional, intraretinal, spicular pigmentation, reminiscent of a carrier phenotype of XLRP. XLRP testing was negative. RetNet-WES testing revealed RHO variant c.404G>C p.(Arg135Pro) in a mosaic state (21% of the reads) in the mother and in a heterozygous state in both sons. Targeted NGQSS of the RHO variant in different maternal tissues showed a mutation load between 25.06% and 41.72%. We report for the first time that somatic mosaicism of RHO variant c.404G>C p.(Arg135Pro) mimics the phenotype of a female carrier of XLRP, in combination with heterozygosity for the variant in the two affected sons
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