197 research outputs found

    Evaluation of social personalized adaptive E-Learning environments : end-user point of view

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    The use of adaptations, along with the social affordances of collaboration and networking, carries a great potential for improving e-learning experiences. However, the review of the previous work indicates current e-learning systems have only marginally explored the integration of social features and adaptation techniques. The overall aim of this research, therefore, is to address this gap by evaluating a system developed to foster social personalized adaptive e-learning experiences. We have developed our first prototype system, Topolor, based on the concepts of Adaptive Educational Hypermedia and Social E-Learning. We have also conducted an experimental case study for the evaluation of the prototype system from different perspectives. The results show a considerably high satisfaction of the end users. This paper reports the evaluation results from end user point of view, and generalizes our method to a component-based evaluation framework

    The Effect of the Pairing Interaction on the Energies of Isobar Analog Resonances in 112124^{112-124}Sb and Isospin Admixture in 100124^{100-124}Sn Isotopes

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    In the present study, the effect of the pairing interaction and the isovector correlation between nucleons on the properties of the isobar analog resonances (IAR) in 112124^{112-124}Sb isotopes and the isospin admixture in 100124^{100-124}Sn isotopes is investigated within the framework of the quasiparticle random phase approximation (QRPA). The form of the interaction strength parameter is related to the shell model potential by restoring the isotopic invariance of the nuclear part of the total Hamiltonian. In this respect, the isospin admixtures in the 100124^{100-124}Sn isotopes are calculated, and the dependence of the differential cross section and the volume integral JFJ_{F} for the Sn(3^{3}He,t)Sb reactions at E(3^{3}He)=200=200 MeV occurring by the excitation of IAR on mass number A is examined. Our results show that the calculated value for the isospin mixing in the 100^{100}Sn isotope is in good agreement with Colo et al.'s estimates (45(4-5%), and the obtained values for the volume integral change within the error range of the value reported by Fujiwara et al. (53±\pm5 MeV fm3^{3}). Moreover, it is concluded that although the differential cross section of the isobar analog resonance for the (3^{3}He,t) reactions is not sensitive to pairing correlations between nucleons, a considerable effect on the isospin admixtures in NZN\approx Z isotopes can be seen with the presence of these correlations.Comment: 16 pages, 5 EPS figures and 2 tables, Late

    Ascites as an initial presentation of spontaneously ruptured hydatid cyst

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    We describe the diagnosis of a 77-year-old woman admitted toour outpatient department with a 3-month history of abdominalbloating and distension. Abdominal computed tomographyrevealed a large cystic lesion in the posterior segment of the righthepatic lobe, with a separated germinal layer and widespreadascites with dense internal echoes and septal appearance. Theresult of a serum Echinococcus indirect haemagglutination testwas positive and findings were indicative of the spontaneousrupture of a hydatid cyst into the peritoneal cavity withouttrauma. Ascites is rarely seen in the course of hydatid disease,but can result from cyst rupture into the peritoneal cavity. Thisshould be considered in the differential diagnosis of ascites,especially in areas such as Turkey, where hydatid disease inendemic

    A review of inorganic photoelectrode developments and reactor scale-up challenges for solar hydrogen production

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    Green hydrogen, produced using solar energy, is a promising means of reducing greenhouse gas emissions. Photoelectrochemical (PEC) water splitting devices can produce hydrogen using sunlight and integrate the distinct functions of photovoltaics and electrolyzers in a single device. There is flexibility in the degree of integration between these electrical and chemical energy generating components, and so a plethora of archetypal PEC device designs has emerged. Although some materials have effectively been ruled out for use in commercial PEC devices, many principles of material design and synthesis have been learned. Here, the fundamental requirements of PEC materials, the top performances of the most widely studied inorganic photoelectrode materials, and reactor structures reported for unassisted solar water splitting are revisited. The main phenomena limiting the performance of up‐scaled PEC devices are discussed, showing that engineering must be considered in parallel with material development for the future piloting of PEC water splitting systems. To establish the future commercial viability of this technology, more accurate techno‐economic analyses should be carried out using data from larger scale demonstrations, and hence more durable and efficient PEC systems need to be developed that meet the challenges imposed from both material and engineering perspectives

    Blind Deconvolution via Lower-Bounded Logarithmic Image Priors

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    In this work we devise two novel algorithms for blind deconvolution based on a family of logarithmic image priors. In contrast to recent approaches, we consider a minimalistic formulation of the blind deconvolution problem where there are only two energy terms: a least-squares term for the data fidelity and an image prior based on a lower-bounded logarithm of the norm of the image gradients. We show that this energy formulation is sufficient to achieve the state of the art in blind deconvolution with a good margin over previous methods. Much of the performance is due to the chosen prior. On the one hand, this prior is very effective in favoring sparsity of the image gradients. On the other hand, this prior is non convex. Therefore, solutions that can deal effectively with local minima of the energy become necessary. We devise two iterative minimization algorithms that at each iteration solve convex problems: one obtained via the primal-dual approach and one via majorization-minimization. While the former is computationally efficient, the latter achieves state-of-the-art performance on a public dataset

    Visualizing Escherichia coli Sub-Cellular Structure Using Sparse Deconvolution Spatial Light Interference Tomography

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    Studying the 3D sub-cellular structure of living cells is essential to our understanding of biological function. However, tomographic imaging of live cells is challenging mainly because they are transparent, i.e., weakly scattering structures. Therefore, this type of imaging has been implemented largely using fluorescence techniques. While confocal fluorescence imaging is a common approach to achieve sectioning, it requires fluorescence probes that are often harmful to the living specimen. On the other hand, by using the intrinsic contrast of the structures it is possible to study living cells in a non-invasive manner. One method that provides high-resolution quantitative information about nanoscale structures is a broadband interferometric technique known as Spatial Light Interference Microscopy (SLIM). In addition to rendering quantitative phase information, when combined with a high numerical aperture objective, SLIM also provides excellent depth sectioning capabilities. However, like in all linear optical systems, SLIM's resolution is limited by diffraction. Here we present a novel 3D field deconvolution algorithm that exploits the sparsity of phase images and renders images with resolution beyond the diffraction limit. We employ this label-free method, called deconvolution Spatial Light Interference Tomography (dSLIT), to visualize coiled sub-cellular structures in E. coli cells which are most likely the cytoskeletal MreB protein and the division site regulating MinCDE proteins. Previously these structures have only been observed using specialized strains and plasmids and fluorescence techniques. Our results indicate that dSLIT can be employed to study such structures in a practical and non-invasive manner

    Neoliberal anti-racism: Responding to ‘everywhere but different’ racism

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    © 2016, © The Author(s) 2016. Racism cannot be treated as a spatially homogeneous phenomenon. This review reports on the merits of a localized approach to anti-racism, and delivers a frank assessment of the challenges faced when developing local responses to racism in a neoliberal era. Under neoliberalism, local actors are responsibilized, and for anti-racism this means action can potentially be closely aligned to local inflexions of racism. But localized responses to racism under neoliberalism are associated with deracialized and depoliticized policies on interethnic community relations. Neoliberal anti-racism promotes competition among local agencies rather than coalition building, and is associated with spatially uneven and non-strategic action
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