2,871 research outputs found

    Solution of a singular integral equation by a split-interval method

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    The article is available at http://www.math.ualberta.ca/ijnam/Volume-4-2007/No-1-07/2007-01-05.pdf. This article is not available through the Chester Digital RepositoryThis article discusses a new numerical method for the solution of a singular integral equation of Volterra type that has an infinite class of solutions. The split-interval method is discussed and examples demonstrate its effectiveness

    Automated grade classification of oral epithelial dysplasia using morphometric analysis of histology images

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    Oral dysplasia is a pre-malignant stage of oral epithelial carcinomas, e.g., oral squamous cell carcinoma, where significant changes in tissue layers and cells can be observed under the microscope. However, malignancy can be reverted or cured using proper medication or surgery if the grade of malignancy is assessed properly. The assessment of correct grade is therefore critical in patient management as it can change the treatment decisions and prognosis for the dysplastic lesion. This assessment is highly challenging due to considerable inter- and intraobserver variability in pathologists’ agreement, which highlights the need for an automated grading system that can predict more accurate and reliable grade. Recent advancements have made it possible for digital pathology (DP) and artificial intelligence (AI) to join forces from the digitization of tissue slides into images and using those images to train and predict more accurate grades using complex AI models. In this regard, we propose a novel morphometric approach exploiting the architectural features in dysplastic lesions i.e., irregular epithelial stratification where we measure the widths of different layers of the epithelium from the boundary layer i.e., keratin projecting inwards to the epithelium and basal layers to the rest of the tissue section from a clinically significant viewpoint

    Direct nucleonemission from hot and dense regions described in the hydrodynamical model of relativistic heavy ion collisions

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    The collision process is described by hydrodynamical equations. The escape of nucleons which do not take part in the thermal equilibrium is considered by including drain terms in these equations. The energy spectra of the escaped nucleons and of nucleons evaporated after the breakup of the fluid are compared. NUCLEAR REACTIONS Relativistic heavy ion reactions, nuclear hydrodynamics, nucleon spectra

    Driving in ZZ Ceti stars - Problem solved?

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    There is a fairly tight correlation between the pulsation periods and effective temperatures of ZZ Ceti stars (cooler stars have longer periods). This seems to fit the theoretical picture, where driving occurs in the partial ionization zone, which lies deeper and deeper within the star as it cools. It is reasonable to assume that the pulsation periods should be related to the thermal timescale in the region where driving occurs. As that region sinks further down below the surface, that thermal timescale increases. Assuming this connection, the pulsation periods could provide an additional way to determine effective temperatures, independent of spectroscopy. We explore this idea and find that in practice, things are not so simple.Comment: 4 pages, 3 figure

    PhyloDetect: a likelihood-based strategy for detecting microorganisms with diagnostic microarrays

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    Motivation: Detection and identification of microbes using diagnostic arrays is still subject of ongoing research. Existing significance-based algorithms consider an organism detected even if a significant number of the microarray probes that match the organism are called absent in a hybridization. Further, they do generate redundant results if the target organisms show high sequence similarity and the microarray probes cannot discriminate all of them. Results: We propose a new analysis strategy that considers organism similarities and calls organisms only present if the probes that match the organism but are absent in a hybridization can be explained by random events. In our strategy, we first identify the groups of target organisms that are actually distinguishable by the array. Subsequently, these organism groups are placed in a hierarchical tree such that groups matching only less specific probes are closer to the tree root, and groups that are discriminated only by few probes are close to each other. Finally, we compute for each group a likelihood score that is based on a hypothesis test with the null hypothesis that the group was actually present in the hybridized sample. We have validated our strategy using datasets from two different array types and implemented it as an easy-to-use web application. Availability: http://www.fgcz.ethz.ch/PhyloDetect Contact: [email protected] Supplementary information: Example data is available at http://www.fgcz.ethz.ch/PhyloDetec

    Risk evaluation using evolvable discriminate function

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    This essay proposes a new approach to risk evaluation using disease mathematical modeling. The mathematical model is an algebraic equation of the available database attributes and is used to evaluate the patient condition. If its value is greater than zero it means that the patient is ill (or in risk condition), otherwise healthy. In practice risk evaluation has been a very difficult problem mainly due its sporadic behavior (suddenly, the patient has a stroke, etc as a condition aggravation) and its database representation. The database contains, under the label of risk patient data, information of the patient condition that sometimes is in risk condition and sometimes is not, introducing errors in the algorithm training. The study was applied to Atherosclerosis database from Discovery Challenge 2003 - ECML/PKDD 2003 workshop

    On the congruent feature in NASTRAN

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    The congruent feature, which is a capability in NASTRAN that can contribute to significant increases in computational efficiencies, is discussed. The usage of the capability and the software design characteristics affecting it are explained. The factors affecting the efficiency of the feature are pointed out. The details pertaining to the software design of the congruent feature are presented; in particular, the congruent element table is described. Serveral examples employing the congruent feature are considered and comparisons of Element Matrix Generator module computer program update times with and without this feature are presented. The results clearly demonstrate the role of the congruent feature in increasing computational efficiencies and its applicability to large-size problems

    The Effects of Conflict on Fertility in Rwanda

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    The aim of this paper is to study the short and long-term fertility effects of mass violent conflict on different population sub-groups. The authors pool three nationally representative demographic and health surveys from before and after the genocide in Rwanda, identifying conflict exposure of the survivors in multiple ways. The analysis finds a robust effect of genocide on fertility, with a strong replacement effect for lost children. Having lost siblings reduces fertility only in the short term. Most interesting is the continued importance of the institution of marriage in determining fertility and in reducing fertility for the large group of widows in Rwanda.conflict, demography, fertility, gender, genocide, Rwanda
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