Count-based imaging model for the Spectrometer/Telescope for Imaging X-rays (STIX) in Solar Orbiter

The Spectrometer/Telescope for Imaging X-rays (STIX) will study solar flares across the hard X-ray window provided by the Solar Orbiter cluster. Similarly to the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI), STIX is a visibility-based imaging instrument that will require Fourier-based image reconstruction methods. However, in this paper we show that as for RHESSI, count-based imaging is also possible for STIX. Specifically, we introduce and illustrate a mathematical model that mimics the STIX data formation process as a projection from the incoming photon flux into a vector consisting of 120 count components. Then we test the reliability of expectation maximization for image reconstruction in the case of several simulated configurations that are typical of flare morphology

The Hough Transform and the Impact of Chronic Leukemia on the Compact Bone Tissue from CT-Images Analysis

Computational analysis of X-ray Computed Tomography (CT) images allows the assessment of alteration of bone structure in adult patients with Advanced Chronic Lymphocytic Leukemia (ACLL), and may even offer a powerful tool to assess the development of the disease (prognostic potential). The crucial requirement for this kind of analysis is the application of a pattern recognition method able to accurately segment the intra-bone space in clinical CT images of the human skeleton. Our purpose is to show how this task can be accomplished by a procedure based on the use of the Hough transform technique for special families of algebraic curves. The dataset used for this study is composed of sixteen subjects including eight control subjects, one ACLL survivor, and seven ACLL victims. We apply the Hough transform approach to the set of CT images of appendicular bones for detecting the compact and trabecular bone contours by using ellipses, and we use the computed semi-axes values to infer information on bone alterations in the population affected by ACLL. The effectiveness of this method is proved against ground truth comparison. We show that features depending on the semi-axes values detect a statistically significant difference between the class of control subjects plus the ACLL survivor and the class of ACLL victims

SIMMER extension for multigroup energy structure search using genetic algorithm with different fitness functions

The multigroup transport theory is the basis for many neutronics modules. A significant point of the cross-section (XS) generation procedure is the choice of the energy groups\u27 boundaries in the XS libraries, which must be carefully selected as an unsuitable energy meshing can easily lead to inaccurate results. This decision can require considerable effort and is particularly difficult for the common user, especially if not well-versed in reactor physics. This work investigates a genetic algorithm-based tool which selects an appropriate XS energy structure (ES) specific for the considered problem, to be used for the condensation of a fine multigroup library. The procedure is accelerated by results storage and fitness calculation speedup and can be easily parallelized. The extension is applied to the coupled code SIMMER and tested on the European Sustainable Nuclear Industrial Initiative (ESNIIþ) Advanced Sodium Technological Reactor for Industrial Demonstration (ASTRID)-like reactor system with different fitness functions. The results show that, when the libraries are condensed based on the ESs suggested by the algorithm, the code actually returns the correct multiplication factor, in both reference and voided conditions. The computational effort reduction obtained by using the condensed library rather than the fine one is assessed and is much higher than the time required for the ES search

Compressed sensing and Sequential Monte Carlo for solar hard X-ray imaging

We describe two inversion methods for the reconstruction of hard Xray solar images. The methods are tested against experimental visibilities recorded by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) and synthetic visibilities based on the design of the Spectrometer/Telescope for Imaging X-rays (STIX)

Avaliação algimétrica e sinérgica em cães tratados pela levomepromazina, induzidos pelo tiopental e mantidos pelo sevofluorano, pré-tratados ou não pelo butorfanol

O artigo não apresenta resumo

Compton Scattering by the Proton using a Large-Acceptance Arrangement

Compton scattering by the proton has been measured using the tagged-photon facility at MAMI (Mainz) and the large-acceptance arrangement LARA. The new data are interpreted in terms of dispersion theory based on the SAID-SM99K parameterization of photo-meson amplitudes. It is found that two-pion exchange in the t-channel is needed for a description of the data in the second resonance region. The data are well represented if this channel is modeled by a single pole with mass parameter m(sigma)=600 MeV. The asymptotic part of the spin dependent amplitude is found to be well represented by pi-0-exchange in the t-channel. A backward spin-polarizability of gamma(pi)=(-37.1+-0.6(stat+syst)+-3.0(model))x10^{-4}fm^4 has been determined from data of the first resonance region below 455 MeV. This value is in a good agreement with predictions of dispersion relations and chiral pertubation theory. From a subset of data between 280 and 360 MeV the resonance pion-photoproduction amplitudes were evaluated leading to a E2/M1 multipole ratio of the p-to-Delta radiative transition of EMR(340 MeV)=(-1.7+-0.4(stat+syst)+-0.2(model))%. It was found that this number is dependent on the parameterization of photo-meson amplitudes. With the MAID2K parameterization an E2/M1 multipole ratio of EMR(340 MeV)=(-2.0+-0.4(stat+syst)+-0.2(model))% is obtained

Gastric nodules with Neospora caninum zooites in a confirmed clinical Neospora caninum infection in a dog

Generalized neosporosis was diagnosed in a two year old rottweiler. The dog had a history of tetraparesis, muscle atrophy, regurgitation and vomiting. Serological analysis by indirect fluorescent antibody test was 1/400 for Neospora caninum. Contrasted radiological surveys showed megaesophagus and during ultrasonografic examination an 8.2 mm diameter mural nodule was observed at the pyloric region. Citologic evaluation revealed highly number of zooites. Microscopically, severe myositis were observed in histologic muscle sections and several groups of tachyzoites and tissue cysts were associated with these lesions. The result of the immunhistochemical staining was: protozoa in muscle sections of the dog stained strongly using 5.2.15 monoclonal antibodies against N. caninum tachyzoites. This paper describes a clinical case of canine neosporosis with vomiting associated to Neospora gastric nodule.Se realizó el diagnóstico de neosporosis generalizada en un canino rottweiler de dos años de edad. El paciente presentaba las siguientes alteraciones: tetraparesia, atrofia muscular, regurgitación y vómito. El resultado del análisis serológico por prueba de inmunofluoresencia indirecta fue 1/400 para Neospora caninum. Los estudios radiológicos contrastados mostraron megaesófago y durante el examen ultrasonográfico se observó un nódulo mural de 8,2 mm de diámetro en la región pilórica. La evaluación citológica reveló numerosos zooítos. En las secciones histológicas de músculo se observaron varios grupos de taquizoitos y quistes asociados a miositis severa. El resultado de las técnicas de immunohistoquímica fue: protozoos en secciones de músculo que se tiñeron fuertemente con 5.2.15 anticuerpos monoclonales contra taquizoitos de N. caninum. Este reporte describe un caso clínico de neosporosis canina con vómitos asociados a nódulo gástrico de Neospora