3,495 research outputs found

    Depth Estimation Through a Generative Model of Light Field Synthesis

    Full text link
    Light field photography captures rich structural information that may facilitate a number of traditional image processing and computer vision tasks. A crucial ingredient in such endeavors is accurate depth recovery. We present a novel framework that allows the recovery of a high quality continuous depth map from light field data. To this end we propose a generative model of a light field that is fully parametrized by its corresponding depth map. The model allows for the integration of powerful regularization techniques such as a non-local means prior, facilitating accurate depth map estimation.Comment: German Conference on Pattern Recognition (GCPR) 201

    Gender and cycling: Gendering cycling subjects and forming bikes, practices and spaces as gendered objects

    Get PDF
    Jennifer Bonham, Carol Bacchi and Thomas Wanne

    NEUROIMÁGENES EN ENFERMEDAD DE PARKINSON: ROL DE LA RESONANCIA MAGNÉTICA, EL SPECT Y EL PET

    Get PDF
    RESUMENLa enfermedad de Parkinson (EP) es un trastorno neurodegenerativo, caracterizado por la pérdida progresiva de neuronas monoaminérgicas, en especial dopaminérgicas. En las últimas décadas, se han desarrollado diversos biomarcadores para el estudio de los pacientes con EP. Un grupo de estos biomarcadores son las neuroimágenes, como la resonancia magnética cerebral y las imágenes moleculares, en particular, la tomografía por emisión de positrones (PET) y la tomografía por emisión de fotón único (SPECT). Estas técnicas, se han empleado en el diagnóstico temprano de la EP, así como para mejorar el diagnóstico diferencial entre EP y otros parkinsonismos y para monitorizar la progresión de la enfermedad. Con estos fines, se ha utilizado la capacidad de estas técnicas para evaluar la pérdida de la actividad dopaminérgica y de otras vías monoaminérgicas, al igual que la posibilidad de valorar la inflamación y el metabolismo a nivel cerebral. Recientemente, los nuevos criterios para el diagnóstico de la EP reconocen al PET y SPECT como herramientas valiosas en el diagnóstico de esta enfermedad. En este artículo, se analiza la utilidad actual de las técnicas de imagen en pacientes con EP y otros parkinsonismos y sus potenciales aplicaciones futuras.SUMMARYParkinson's disease (PD) is a neurodegenerative disorder characterized by a progressive loss of monoaminergic neurons, particularly dopaminergic cell groups. Biomarkers have been developed in the last decades for the study of PD patients. Neuroimages, including Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography are part of these biomarkers evaluated in PD. These techniques had been used for the early diagnosis of PD, for the differential diagnosis between PD and other parkinsonisms and to monitor the progression of these disorders. The ability of these images to evaluate loss of monoaminergic activity and their capacity to estimate inflammatory and metabolic changes in the brain has been used. Recently the new criteria for diagnosis of PD have incorporated to PET and SPECT as useful tools in the diagnosis of this disorder. In this article, we review the utility of the neuroimages in patients with PD and some of their potential future applications

    Winter precipitation trends for two selected European regions over the last 500 years and their possible dynamical background

    Get PDF
    Summary: We analyse winter (DJF) precipitation over the last 500 years on trends using a spatially and temporally highly resolved gridded multi-proxy reconstruction over European land areas. The trends are detected applying trend matrices, and the significance is assessed with the Mann-Kendall-trend test. Results are presented for southwestern Norway and southern Spain/northern Morocco, two regions that show high reconstruction skill over the entire period. The absolute trend values found in the second part of the 20th century are unprecedented over the last 500 years in both regions. During the period 1715-1765, the precipitation trends were most pronounced in southwestern Norway as well as southern Spain/northern Morocco, with first a distinct negative trend followed by a positive countertrend of similar strength. Relating the precipitation time series to variations of the North Atlantic Oscillation Index (NAOI) and the solar irradiance using running correlations revealed a couple of instationarities. Nevertheless, it appears that the NAO is responsible in both regions for most of the significant winter precipitation trends during the earlier centuries as well as during recent decades. Some of the significant winter precipitation trends over southwestern Norway and southern Spain/northern Morocco might be related to changes in the solar irradianc

    From WEDA to EDTA to ERA: 60 years of supporting European nephrology and counting

    Get PDF
    Nephrology has evolved from treating kidney failure, first with dialysis and then with kidney transplantation, to identifying and treating early stages of kidney disease and eventually to prevent kidney disease from occurring. Similarly, the name of the European scientific society caring for people with kidney disease has evolved from the West European Dialysis Society Association to the European Dialysis and Transplant Association to the European Renal Association. These name changes reflect a deeper change in the mission of the society to the current mission of leading European nephrology by promoting kidney health for all, improving kidney care for patients, and strengthen the kidney community and the vision of a Europe where kidney health is prioritized, kidney health is accessible and the kidney community is thriving. We now review the major changes in the society over the years and present its current structure and focus as we face the largest projected increase to date in the global burden of kidney diseases

    On the use of Li isotopes as a proxy for water–rock interaction in fractured crystalline rocks: a case study from the Gotthard rail base tunnel

    Get PDF
    We present Li isotope measurements of groundwater samples collected during drilling of the 57 km long Gotthard rail base tunnel in Switzerland, to explore the use of Li isotope measurements for tracking water–rock interactions in fractured crystalline rocks at temperatures of up to 43 °C. The 17 groundwater samples originate from water-conducting fractures within two specific crystalline rock units, which are characterized by a similar rock mineralogy, but significantly different fluid composition. In particular, the aqueous Li concentrations observed in samples from the two units vary from 1–4 mg/L to 0.01–0.02 mg/L. Whereas δ7Li values from the unit with high Li concentrations are basically constant (δ7Li = 8.5–9.1‰), prominent variations are recorded for the samples from the unit with low Li concentrations (δ7Li = 10–41‰). This observation demonstrates that Li isotope fractionation can be highly sensitive to aqueous Li concentrations. Moreover, δ7Li values from the unit with low Li concentrations correlate well with reaction progress parameters such as pH and [Li]/[Na] ratios, suggesting that δ7Li values are mainly controlled by the residence time of the fracture groundwater. Consequently, 1D reactive transport modeling was performed to simulate mineral reactions and associated Li isotope fractionation along a water-conducting fracture system using the code TOUGHREACT. Modeling results confirm the residence time hypothesis and demonstrate that the absence of δ7Li variation at high Li concentrations can be well explained by limitation of the amount of Li that is incorporated into secondary minerals. Modeling results also suggest that Li uptake by kaolinite forms the key process to cause Li isotope fractionation in the investigated alkaline system (pH >9), and that under slow flow conditions (<10 m/year), this process is associated with a very large Li isotope fractionation factor (ε ≈ −50‰). Moreover, our simulations demonstrate that for simple and well-defined systems with known residence times and low Li concentrations, δ7Li values may help to quantify mineral reaction rates if more thermodynamic data about the temperature-dependent incorporation of Li in secondary minerals as well as corresponding fractionation factors become available in the future. In conclusion, δ7Li values may be a powerful tool to track water–rock interaction in fractured crystalline rocks at temperature higher than those at the Earth’s surface, although their use is restricted to low Li concentrations and well defined flow systems

    Synthesis and biological evaluation of α- and β-hydroxy substituted amino acid derivatives as potential mGAT1-4 inhibitors

    Get PDF
    &lt;jats:title&gt;Abstract&lt;/jats:title&gt;&lt;jats:p&gt;In this study, we report the synthesis and biological evaluation of a variety of α- and β-hydroxy substituted amino acid derivatives as potential amino acid subunits in inhibitors of GABA uptake transporters (GATs). In order to ensure that the test compounds adopt a binding pose similar to that presumed for related larger GAT inhibitors, lipophilic residues were introduced either at the amino nitrogen atom or at the alcohol function. Several of the synthesized compounds were found to exhibit similar inhibitory activity at the GAT subtypes mGAT2, mGAT3, and mGAT4, respectively, as compared with the reference N-butylnipecotic acid. Hence, these compounds might serve as starting point for future developments of more complex GAT inhibitors.&lt;/jats:p&gt

    The calcar screw in angular stable plate fixation of proximal humeral fractures - a case study

    Full text link
    Background: With new minimally-invasive approaches for angular stable plate fixation of proximal humeral fractures, the need for the placement of oblique inferomedial screws ('calcar screw') has increasingly been discussed. The purpose of this study was to investigate the influence of calcar screws on secondary loss of reduction and on the occurrence of complications. Methods: Patients with a proximal humeral fracture who underwent angular stable plate fixation between 01/2007 and 07/2009 were included. On AP views of the shoulder, the difference in height between humeral head and the proximal end of the plate were determined postoperatively and at follow-up. Additionally, the occurrence of complications was documented. Patients with calcar screws were assigned to group C+, patients without to group C-. Results: Follow-up was possible in 60 patients (C+ 6.7 ± 5.6 M/C- 5.0 ± 2.8 M). Humeral head necrosis occurred in 6 (C+, 15.4%) and 3 (C-, 14.3%) cases. Cut-out of the proximal screws was observed in 3 (C+, 7.7%) and 1 (C-, 4.8%) cases. In each group, 1 patient showed delayed union. Implant failure or lesions of the axillary nerve were not observed. In 44 patients, true AP and Neer views were available to measure the head-plate distance. There was a significant loss of reduction in group C- (2.56 ± 2.65 mm) compared to C+ (0.77 ± 1.44 mm; p = 0.01). Conclusions: The placement of calcar screws in the angular stable plate fixation of proximal humeral fractures is associated with less secondary loss of reduction by providing inferomedial support. An increased risk for complications could not be shown

    Comparando Algoritmos Evolutivos Baseados em Decomposição para Problemas de Otimização Multiobjetivo e com Muitos Objetivos

    Get PDF
    Many real-world problems can be mathematically modeled as Multiobjective Optimization Problems (MOPs), as they involve multiple conflicting objective functions that must be minimized simultaneously. MOPs with more than 3 objective functions are called Many-objective Optimization Problems (MaOPs). MOPs are typically solved through Multiobjective Evolutionary Algorithms (MOEAs), which can obtain a set of non-dominated optimal solutions, known as a Pareto front, in a single run. The MOEA Based on Decomposition (MOEA/D) is one of the most efficient, dividing a MOP into several single-objective subproblems and optimizing them simultaneously. This study evaluated the performance of MOEA/D and four variants representing the state of the art in the literature (MOEA/DD, MOEA/D-DE, MOEA/D-DU, and MOEA/D-AWA) in MOPs and MaOPs. Computational experiments were conducted using benchmark MOPs and MaOPs from the DTLZ suite considering 3 and 5 objective functions. Additionally, a statistical analysis, including the Wilcoxon test, was performed to evaluate the results obtained in the IGD+ performance indicator. The Hypervolume performance indicator was also considered in the combined Pareto front, formed by all solutions obtained by each MOEA. The experiments revealed that MOEA/DD performed best in IGD+, and MOEA/D-AWA achieved the highest Hypervolume in the combined Pareto front, while MOEA/D-DE registered the worst result in this set of problems.Muitos problemas oriundos do mundo real podem ser modelados matematicamente como Problemas de Otimização Multiobjetivo (POMs), já que possuem diversas funções objetivo conflitantes entre si que devem ser minimizadas simultaneamente. POMs com mais de 3 funções objetivo recebem o nome de Problemas de Otimização com Muitos Objetivos (MaOPs, do inglês Many-objective Optimization Problems). Os POMs geralmente são resolvidos através de Algoritmos Evolutivos Multiobjetivos (MOEAs, do inglês Multiobjective Evolutionary Algorithms), os quais conseguem obter um conjunto de soluções ótimas não dominadas entre si, conhecidos como frente de Pareto, em uma única execução. O MOEA baseado em decomposição (MOEA/D) é um dos mais eficientes, o qual divide um POM em vários subproblemas monobjetivos otimizando-os ao mesmo tempo. Neste estudo foi realizada uma avaliação dos desempenhos do MOEA/D e quatro de suas variantes que representam o estado da arte da literatura (MOEA/DD, MOEA/D-DE, MOEA/D-DU e MOEA/D-AWA) em POMs e MaOPs. Foram conduzidos experimentos computacionais utilizando POMs e MaOPs benchmark do suite DTLZ considerando 3 e 5 funções objetivo. Além disso, foi realizada uma análise estatística que incluiu o teste de Wilcoxon para avaliar os resultados obtidos no indicador de desempenho IGD+. Também foi considerado o indicador de desempenho Hypervolume na frente de Pareto combinada, que é formada por todas as soluções obtidas por cada MOEA. Os experimentos revelaram que o MOEA/DD apresentou a melhor performance no IGD+ e o MOEA/D-AWA obteve o maior Hypervolume na frente de Pareto combinada, enquanto o MOEA/D-DE registrou o pior resultado nesse conjunto de problemas
    corecore