179 research outputs found
Complementary geometric and optical information for match-propagation-based 3D reconstruction
International audienceIn this work, we consider the problem of propagation-based matching for 3D reconstruction, which deals with expanding a limited set of correspondences towards a quasi-dense map across two views. In general, propagation based methods capture well the scene structure. However, the recovered geometry often presents an overall choppy na-ture which can be attributed to matching errors and abrupt variations in the estimated local affine transformations. We propose to control the reconstructed geometry by means of a local patch fitting which corrects both the matching locations and affine transformations throughout the propagation process. In this way, matchings that propagate from geo-metrically consolidated locations bring coherence to both positions and affine transformations. Results of our approach are not only more visu-ally appealing but also more accurate and complete as substantiated by results on standard benchmarks
The genome of Δ15, a serotype-converting, Group E1 Salmonella enterica-specific bacteriophage
AbstractThe genome sequence of the Salmonella enterica serovar Anatum-specific, serotype-converting bacteriophage Δ15 has been completed. The nonredundant genome contains 39,671 bp and 51 putative genes. It most closely resembles the genome of ÏV10, an Escherichia coli O157:H7-specific temperate phage, with which it shares 36 related genes. More distant relatives include the Burkholderia cepacia-specific phage, BcepC6B (8 similar genes), the Bordetella bronchiseptica-specific phage, BPP-1 (8 similar genes) and the Photobacterium profundum prophage, P PÏpr1 (6 similar genes).Δ15 gene identifications based on homologies with known gene families include the terminase small and large subunits, integrase, endolysin, two holins, two DNA methylase enzymes (one adenine-specific and one cytosine-specific) and a RecT-like enzyme. Genes identified experimentally include those coding for the serotype conversion proteins, the tail fiber, the major capsid protein and the major repressor. Δ15's attP site and the Salmonella attB site with which it interacts during lysogenization have also been determined
Anisotropy studies around the galactic centre at EeV energies with the Auger Observatory
Data from the Pierre Auger Observatory are analyzed to search for
anisotropies near the direction of the Galactic Centre at EeV energies. The
exposure of the surface array in this part of the sky is already significantly
larger than that of the fore-runner experiments. Our results do not support
previous findings of localized excesses in the AGASA and SUGAR data. We set an
upper bound on a point-like flux of cosmic rays arriving from the Galactic
Centre which excludes several scenarios predicting sources of EeV neutrons from
Sagittarius . Also the events detected simultaneously by the surface and
fluorescence detectors (the `hybrid' data set), which have better pointing
accuracy but are less numerous than those of the surface array alone, do not
show any significant localized excess from this direction.Comment: Matches published versio
Relationship between human tumour angiogenic profile and combretastatin-induced vascular shutdown: an exploratory study
Combretastatin-A4-phosphate (CA4P) acts most effectively against immature tumour vasculature. We investigated whether histological angiogenic profile can explain the differential sensitivity of human tumours to CA4P, by correlating the kinetic changes demonstrated by dynamic MRI (DCE-MRI) in response to CA4P, with tumour immunohistochemical angiogenic markers. Tissue was received from 24 patients (mean age 59, range 32â73, 18 women, 6 men). An angiogenic profile was performed using standard immunohistochemical techniques. Dynamic MRI data were obtained for the same patients before and 4âh after CA4P. Three patients showed a statistically significant fall in Ktrans following CA4P, and one a statistically significant fall in IAUGC60. No statistically significant correlations were seen between the continuous or categorical variables and the DCE-MRI kinetic parameters other than between ang-2 and Ktrans (P=0.044). In conclusion, we found no strong relationships between changes in DCE-MRI kinetic variables following CA4P and the immunohistochemical angiogenic profile
Memetic electromagnetism algorithm for surface reconstruction with rational bivariate Bernstein basis functions
Surface reconstruction is a very important issue with outstanding applications in fields such as medical imaging (computer tomography, magnetic resonance), biomedical engineering (customized prosthesis and medical implants), computer-aided design and manufacturing (reverse engineering for the automotive, aerospace and shipbuilding industries), rapid prototyping (scale models of physical parts from CAD data), computer animation and film industry (motion capture, character modeling), archaeology (digital representation and storage of archaeological sites and assets), virtual/augmented reality, and many others. In this paper we address the surface reconstruction problem by using rational BĂ©zier surfaces. This problem is by far more complex than the case for curves we solved in a previous paper. In addition, we deal with data points subjected to measurement noise and irregular sampling, replicating the usual conditions of real-world applications. Our method is based on a memetic approach combining a powerful metaheuristic method for global optimization (the electromagnetism algorithm) with a local search method. This method is applied to a benchmark of five illustrative examples exhibiting challenging features. Our experimental results show that the method performs very well, and it can recover the underlying shape of surfaces with very good accuracy.This research is kindly supported by the Computer Science National Program of the Spanish Ministry of Economy and Competitiveness, Project #TIN2012-30768, Toho University, and the University of Cantabria. The authors are particularly grateful to the Department of Information Science of Toho University for all the facilities given to carry out this work. We also thank the Editor and the two anonymous reviewers who helped us to improve our paper with several constructive comments and suggestions
Dermatologist-like explainable AI enhances trust and confidence in diagnosing melanoma
Although artificial intelligence (AI) systems have been shown to improve the
accuracy of initial melanoma diagnosis, the lack of transparency in how these
systems identify melanoma poses severe obstacles to user acceptance.
Explainable artificial intelligence (XAI) methods can help to increase
transparency, but most XAI methods are unable to produce precisely located
domain-specific explanations, making the explanations difficult to interpret.
Moreover, the impact of XAI methods on dermatologists has not yet been
evaluated. Extending on two existing classifiers, we developed an XAI system
that produces text and region based explanations that are easily interpretable
by dermatologists alongside its differential diagnoses of melanomas and nevi.
To evaluate this system, we conducted a three-part reader study to assess its
impact on clinicians' diagnostic accuracy, confidence, and trust in the
XAI-support. We showed that our XAI's explanations were highly aligned with
clinicians' explanations and that both the clinicians' trust in the support
system and their confidence in their diagnoses were significantly increased
when using our XAI compared to using a conventional AI system. The clinicians'
diagnostic accuracy was numerically, albeit not significantly, increased. This
work demonstrates that clinicians are willing to adopt such an XAI system,
motivating their future use in the clinic
Phase II trial of imatinib mesylate in patients with metastatic melanoma
Metastatic melanoma cells express a number of protein tyrosine kinases (PTKs) that are considered to be targets for imatinib. We conducted a phase II trial of imatinib in patients with metastatic melanoma expressing at least one of these PTKs. Twenty-one patients whose tumours expressed at least one PTK (c-kit, platelet-derived growth factor receptors, c-abl, or abl-related gene) were treated with 400âmg of imatinib twice daily. One patient with metastatic acral lentiginous melanoma, containing the highest c-kit expression among all patients, had dramatic improvement on positron emission tomographic scan at 6 weeks and had a partial response lasting 12.8 months. The responder had a substantial increase in tumour and endothelial cell apoptosis at 2 weeks of treatment. Imatinib was fairly well tolerated: no patient required treatment discontinuation because of toxicity. Fatigue and oedema were the only grade 3 or 4 toxicities that occurred in more than 10% of the patients. Imatinib at the studied dose had minimal clinical efficacy as a single-agent therapy for metastatic melanoma. However, based on the characteristics of the responding tumour in our study, clinical activity of imatinib, specifically in patients with melanoma with certain c-kit aberrations, should be examined
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