32 research outputs found

    Maximum Likelihood Estimation of Head Motion Using Epipolar Consistency

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    Open gantry C-arm systems that are placed within the interventional room enable 3-D imaging and guidance for stroke therapy without patient transfer. This can profit in drastically reduced time-totherapy, however, due to the interventional setting, the data acquisition is comparatively slow. Thus, involuntary patient motion needs to be estimated and compensated to achieve high image quality. Patient motion results in a misalignment of the geometry and the acquired image data. Consistency measures can be used to restore the correct mapping to compensate the motion. They describe constraints on an idealized imaging process which makes them also sensitive to beam hardening, scatter, truncation or overexposure. We propose a probabilistic approach based on the Student’s t-distribution to model image artifacts that affect the consistency measure without sourcing from motion

    Hydrolysis of tannic acid catalyzed by immobilized-stabilized derivatives of tannase from Lactobacillus plantarum

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    A recombinant tannase from Lactobacillus plantarum, overexpressed in Escherichia coli, was purified in a single step by metal chelate affinity chromatography on poorly activated nickel supports. It was possible to obtain 0.9 g of a pure enzyme by using only 20 mL of chromatographic support. The pure enzyme was immobilized and stabilized by multipoint covalent immobilization on highly activated glyoxyl agarose. Derivatives obtained by multipoint and multisubunit immobilization were 500- and 1000-fold more stable than both the soluble enzyme and the one-point-immobilized enzyme in experiments of thermal and cosolvent inactivation, respectively. In addition, up to 70 mg of pure enzyme was immobilized on 1 g of wet support. The hydrolysis of tannic acid was optimized by using the new immobilized tannase derivative. The optimal reaction conditions were 30% diglyme at pH 5.0 and 4 C. Under these conditions, it was possible to obtain 47.5 mM gallic acid from 5 mM tannic acid as substrate. The product was pure as proved by HPLC. On the other hand, the immobilized biocatalyst preserved >95% of its initial activity after 1 month of incubation under the optimal reaction conditionsThis work was supported by Grants AGL2008-01052, AGL-2009-07625, Consolider INGENIO 2010 CSD2007-00063 FUN-C-FOOD(CICYT),RM2008-00002 (INIA), and S-0505/AGR/000153 (CAM). J.A.C. is the recipient of a predoctoral fellowship from the I3P-CSIC Program and FPI-MEC, and G.F.-L. and L.B. are recipients of Ramon y Cajal postdoctoral contracts.Peer reviewe

    Биогеохимические исследования урбанизированных ландшафтов восточной Финляндии

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    Объектом исследования являются урбанизированные ландшафты трех городов Восточной Финляндии г. Юука, г. Оутокумпу, г. Миккели. Цель работы - биогеохимические исследования урбанизированных ландшафтов восточной Финляндии по результатам исследования проб почв, листьев и стеблей черники, лишайника, листьев древесных растений. В процессе исследования проводились обзор и анализ ранее проведенных работ, анализы литературных, нормативных и фондовых источников, анализировались статистических данные и элементный состав комплекса природных сред. В результате исследования была изучена геоэкологическая обстановка урбанизированных территорий Восточной Финляндии Степень внедрения результатов: полученный анализ эколого-геохимической ситуации урбанизированных территорий Финляндии является составной частью комплексного эколого-геохимического мониторинга территорий, проводимого кафедрой ГЭГХ ТПУ. Аналитический материал будет использован в учебном процессе. Область применения: результаты эколого-геохимического мониторинга урбанизированных территорий Финляндии могут быть использованы природоохранными организациями для ориентировочных данных по содержанию химических элементов в почвах и живых объектах городских агломераций.Object of research are urban landscapes of the three cities in the Eastern Finland city of Juuka, in Outokumpu, the city of Mikkeli. Purpose - biogeochemical studies of the urban landscape of Eastern Finland the results of the research of samples of soil, leaves and stems of bilberry, lichen, leaves of woody plants. In the process of investigation the review and analysis of earlier conducted works, literary analyses, regulatory and archival sources, analyzed statistical data and elemental composition of complex natural environments. The study was studied geo-ecological situation in the urbanized territories of Eastern Finland level of implementation of results: the analysis of environmental and geochemical situation in the urbanized territories of Finland is part of an integrated ecological-geochemical monitoring of the territories held by the Department GEGH TPU. Analytical material will be used in the educational process. Application field: the results of ecological-geochemical monitoring in the urbanized territories of Finland can be used by conservation organizations for estimates on the content of chemical elements in the soils and the living facilities of urban agglomerations

    Organizzazione e flessibilità dell'impresa edile: evoluzione dei modelli in tre paesi europei. Francia, Italia, Repubblica Federale Tedesca

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    Il libro tratta della flessibilità delle imprese di costruzione in Francia, Italia e Germania e dei vari modelli organizzativi adottati. Il libro esamina poi le dimaniche di settore nei tre paesi

    Towards in vivo X ray nanoscopy The effect of motion on image quality

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    Novel X Ray Microscopy XRM systems allow to study the internal structure of a specimen on nanoscale. A possible use of this non destructive technology is motivated in the medical research area. In Vivo investigation of medication over a period of time and its effects on perfusion and bony structure might lead to a better understanding of drug mechanisms and diseases like Osteoporosis and could lead to new approaches to their treatment. The first step towards in vivo XRM imaging is to investigate the suitability of recent XRM systems for this task and subsequently to determine the system parameters. In this context, the impact of mice motion on the image quality is studied in this work. This paper aims to simulate the effects of breathing motion and muscle relaxation of the mice on the reconstructed images, which already effects the projection images. We therefore assume a mouse s respiration motion pattern, which happens four time during a single projection acquisitions, and the muscle relaxation movement due to anesthesia and simulate its impacts on image quality. Additionally, we show that a frame rate of at least 16 fps is needed to capture in vivo movements in order to apply state of the art motion correction method

    Pålagt delt fast bosted: En analyse av lagmannsrettspraksis - hvilke momenter vektlegges og hvilken vekt har de?

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    Labelling data is expensive and time consuming especially for domains such as medical imaging that contain volumetric imaging data and require expert knowledge. Exploiting a larger pool of labeled data available across multiple centers, such as in federated learning, has also seen limited success since current deep learning approaches do not generalize well to images acquired with scanners from different manufacturers. We aim to address these problems in a common, learning-based image simulation framework which we refer to as Federated Simulation. We introduce a physics-driven generative approach that consists of two learnable neural modules: 1) a module that synthesizes 3D cardiac shapes along with their materials, and 2) a CT simulator that renders these into realistic 3D CT Volumes, with annotations. Since the model of geometry and material is disentangled from the imaging sensor, it can effectively be trained across multiple medical centers. We show that our data synthesis framework improves the downstream segmentation performance on several datasets. Project Page: https://nv-tlabs.github.io/fed-sim/ .Comment: MICCAI 2020 (Early Accept
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