472 research outputs found

    Distinguishing Healthy Ageing from Dementia: A Biomechanical Simulation of Brain Atrophy Using Deep Networks

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    Biomechanical modeling of tissue deformation can be used to simulate different scenarios of longitudinal brain evolution. In this work, we present a deep learning framework for hyper-elastic strain modelling of brain atrophy, during healthy ageing and in Alzheimer’s Disease. The framework directly models the effects of age, disease status, and scan interval to regress regional patterns of atrophy, from which a strain-based model estimates deformations. This model is trained and validated using 3D structural magnetic resonance imaging data from the ADNI cohort. Results show that the framework can estimate realistic deformations, following the known course of Alzheimer’s disease, that clearly differentiate between healthy and demented patterns of ageing. This suggests the framework has potential to be incorporated into explainable models of disease, for the exploration of interventions and counterfactual examples

    Quasi-normal modes, area spectra and multi-horizon spacetimes

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    We suggest an interpretation for the highly damped QNM frequencies of the spherically symmetric multi-horizon spacetimes (Reissner-Nordstrom, Schwarzschild-deSitter, Reissner-Nordstrom-deSitter) following Maggiore's proposal about the link between the asymptotic QNM frequencies and the black hole thermodynamics. We show that the behavior of the asymptotic frequencies is easy to understand if one assumes that all of the horizons have the same equispaced area spectra. The QNM analysis is then consistent with the choice of the area spectra to be the one originally proposed for the black hole's horizon by Bekenstein: A=8\pi n (in Planck units). The interpretation of the highly damped QNM frequencies in the multi-horizon case is based on the similar grounds as in the single horizon (Schwarzschild) case, but it has some new features that are discussed in the paper.Comment: 8 pages, v2: no physics changed, some references added, few sentences added in the discussion part

    Mycobacterium bovis: polymerase chain reaction identification in bovine Lymphonode biopsies and genotyping in isolates from Southeast Brazil by spolygotyping and restriction fragment length polymorphism

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    Diagnosis of the Mycobacterium tuberculosis complex by direct PCR of mediastinal lymphnode DNA and microbiological tests were compared in cattle suspicious of bearing tuberculous-like lesions detected during slaughter. The PCR procedure applied on DNA samples (n=54) obtained by adding alpha -casein into the thiocyanate extraction mix was positive in 70% of the samples. PCR confirmed the identification of 23 samples (100%) that grew in culture, 9 samples (60%) that failed to grow in culture, plus 6 (37.5%) samples that resulted in growth of bacterial contaminants. Genotyping by IS6110-RFLP and DR-spoligotyping analysis of seven samples revealed the presence of several polimorphisms. Seven of the isolates contained multiple copies of IS6110, thus defining the existence of five singular genotypes.ICB Departamento de Bioquímica e Imunologia Laboratório de Biologia Molecular de Produtos NaturaisUniversidade Federal de Minas Gerais ICB Escola de VeterináriaUniversidade Federal de Minas Gerais ICB Departamento de FarmacologiaEscola Paulista de Medicina Departamento de Microbiologia e ParasitologiaLaboratório Central do Estado do Espírito SantoInstituto Biológico de São PauloCentro de Investigación en Ciencias Veterinarias Instituto de BiotecnologiaUNIFESP, EPM, Depto. de Microbiologia e ParasitologiaSciEL

    A specification-based QoS-aware design framework for service-based applications

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    Effective and accurate service discovery and composition rely on complete specifications of service behaviour, containing inputs and preconditions that are required before service execution, outputs, effects and ramifications of a successful execution and explanations for unsuccessful executions. The previously defined Web Service Specification Language (WSSL) relies on the fluent calculus formalism to produce such rich specifications for atomic and composite services. In this work, we propose further extensions that focus on the specification of QoS profiles, as well as partially observable service states. Additionally, a design framework for service-based applications is implemented based on WSSL, advancing state of the art by being the first service framework to simultaneously provide several desirable capabilities, such as supporting ramifications and partial observability, as well as non-determinism in composition schemas using heuristic encodings; providing explanations for unexpected behaviour; and QoS-awareness through goal-based techniques. These capabilities are illustrated through a comparative evaluation against prominent state-of-the-art approaches based on a typical SBA design scenario

    Nematode and Arthropod Genomes Provide New Insights into the Evolution of Class 2 B1 GPCRs

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    Nematodes and arthropods are the most speciose animal groups and possess Class 2 B1 G-protein coupled receptors (GPCRs). Existing models of invertebrate Class 2 B1 GPCR evolution are mainly centered on Caenorhabditis elegans and Drosophila melanogaster and a few other nematode and arthropod representatives. The present study reevaluates the evolution of metazoan Class 2 B1 GPCRs and orthologues by exploring the receptors in several nematode and arthropod genomes and comparing them to the human receptors. Three novel receptor phylogenetic clusters were identified and designated cluster A, cluster B and PDF-R-related cluster. Clusters A and B were identified in several nematode and arthropod genomes but were absent from D. melanogaster and Culicidae genomes, whereas the majority of the members of the PDF-R-related cluster were from nematodes. Cluster A receptors were nematode and arthropod-specific but shared a conserved gene environment with human receptor loci. Cluster B members were orthologous to human GCGR, PTHR and Secretin members with which they probably shared a common origin. PDF-R and PDF-R related clusters were present in representatives of both nematodes and arthropods. The results of comparative analysis of GPCR evolution and diversity in protostomes confirm previous notions that C. elegans and D. melanogaster genomes are not good representatives of nematode and arthropod phyla. We hypothesize that at least four ancestral Class 2 B1 genes emerged early in the metazoan radiation, which after the protostome-deuterostome split underwent distinct selective pressures that resulted in duplication and deletion events that originated the current Class 2 B1 GPCRs in nematode and arthropod genomes.This work was supported by the Portuguese Foundation for Science and Technology (FCT) project PTDC/BIA-BCM/114395/2009, by the European Regional Development Fund through COMPETE and FCT under the project ‘‘PEst-C/MAR/LA0015/2011.’’ RCF is in receipt of an FCT grant (SFRH/BPD/89811/2012) and JCRC is supported by auxiliary research contract FCT Pluriannual funds attributed to CCMAR. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Children day care center: exposition or protection environment to intestinal parasites infestation in Aracaju, SE

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    Para avaliar se creches são ambientes protetores ou propiciadores de infestação intestinal, foi feito exame coproparasitológico de crianças de creche e grupo controle. Creche relacionou-se à maior prevalência de parasitoses (63% x 41,4 % ; p<0,01), com risco de infestação 1,5 vez maior

    MR imaging of overuse injuries in the skeletally immature gymnast: spectrum of soft-tissue and osseous lesions in the hand and wrist

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    In the pediatric gymnast, stress-related physeal injuries have been well described with characteristic imaging findings. However, a spectrum of overuse injuries, some rarely reported in the literature, can be encountered in the gymnast’s hand and wrist. To demonstrate the MR appearance of a spectrum of overuse injuries in the skeletally immature wrist and hand of pediatric gymnasts. A total of 125 MR exams of the hand and wrist in skeletally immature children were performed at our institution during a 2-year period. Clinical histories were reviewed for gymnastics participation. MR studies of that subpopulation were reviewed and abnormalities tabulated. Of the MR studies reviewed, ten gymnasts were identified, all girls age 12–16 years (mean age 14.2 years) who presented with wrist or hand pain. Three of these children had bilateral MR exams. Abnormalities included chronic physeal injuries in three children. Two girls exhibited focal lunate osteochondral defects. Triangular fibrocartilage tears were present in three girls, one of whom had a scapholunate ligament tear. Two girls manifested metacarpal head flattening and necrosis. A variety of soft-tissue and osseous lesions can be encountered in the skeletally immature gymnast. Familiarity with these stress-related injuries is important for accurate diagnosis
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