334 research outputs found

    A Multi Hidden Recurrent Neural Network with a Modified Grey Wolf Optimizer

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    Identifying university students' weaknesses results in better learning and can function as an early warning system to enable students to improve. However, the satisfaction level of existing systems is not promising. New and dynamic hybrid systems are needed to imitate this mechanism. A hybrid system (a modified Recurrent Neural Network with an adapted Grey Wolf Optimizer) is used to forecast students' outcomes. This proposed system would improve instruction by the faculty and enhance the students' learning experiences. The results show that a modified recurrent neural network with an adapted Grey Wolf Optimizer has the best accuracy when compared with other models.Comment: 34 pages, published in PLoS ON

    A new approach to search result clustering and labeling

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    Search engines present query results as a long ordered list of web snippets divided into several pages. Post-processing of retrieval results for easier access of desired information is an important research problem. In this paper, we present a novel search result clustering approach to split the long list of documents returned by search engines into meaningfully grouped and labeled clusters. Our method emphasizes clustering quality by using cover coefficient-based and sequential k-means clustering algorithms. A cluster labeling method based on term weighting is also introduced for reflecting cluster contents. In addition, we present a new metric that employs precision and recall to assess the success of cluster labeling. We adopt a comparative strategy to derive the relative performance of the proposed method with respect to two prominent search result clustering methods: Suffix Tree Clustering and Lingo. Experimental results in the publicly available AMBIENT and ODP-239 datasets show that our method can successfully achieve both clustering and labeling tasks. © 2011 Springer-Verlag Berlin Heidelberg

    Spectroscopic Evidence for Multiple Order Parameter Components in the Heavy Fermion Superconductor CeCoIn_5

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    Point-contact spectroscopy was performed on single crystals of the heavy-fermion superconductor CeCoIn_5 between 150 mK and 2.5 K. A pulsed measurement technique ensured minimal Joule heating over a wide voltage range. The spectra show Andreev-reflection characteristics with multiple structures which depend on junction impedance. Spectral analysis using the generalized Blonder-Tinkham-Klapwijk formalism for d-wave pairing revealed two coexisting order parameter components, with amplitudes Delta_1 = 0.95 +/- 0.15 meV and Delta_2 = 2.4 +/- 0.3 meV, which evolve differently with temperature. Our observations indicate a highly unconventional pairing mechanism, possibly involving multiple bands.Comment: 4 pages, 3 figure

    A new class of platinum(II) complexes with the phosphine ligand pta which show potent anticancer activity

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    The anticancer potential of sixteen platinum(II) complexes with general formulae [PtCl(hq)(S-dmso)] (1a-8a) and [PtCl(hq)(pta)] (1b-8b) (where hq is 5-chloro-7-iodo-8-quinolinol (clioquinol; cqH) (1a, 1b), 8-hydroxy-5-nitroquinoline (nitroxoline; nxH) (2a, 2b), 5,7-dichloro-8-quinolinol (3a, 3b), 5,7-diiodo-8-quinolinol (4a, 4b), 5,7-dibromo-8-quinolinol (5a, 5b), 5,7-dichloro-8-hydroxy-2-methyl-quinoline (6a, 6b), 8-hydroxyquinoline (7a, 7b) and 8-quinolinethiol (8a, 8b); dmso is dimethyl sulfoxide and pta is 1,3,5triaza- 7-phosphaadamantane) was determined through in vitro cytotoxicity assay in human fibroblasts (MRC5) and two carcinoma cell lines (A375 and A549) and embryotoxicity assay in a zebrafish model. Interactions with double stranded DNA through in vitro assay and a molecular docking study were examined. All complexes, except 6a, exhibited a high cytotoxic effect on MRC5 cells at a concentration of 10 mu g mL(-1) while 1b, 5a, 6a and 3b showed selective toxicity towards carcinoma cell lines. In general, pta-based complexes (series b) were more toxic according to the results of a MTT screen and the LC50 values obtained in zebrafish (Danio rerio) assay; they also induced higher oxidative stress in this model. Successful cellular uptake of complexes was shown by the ICP-MS methodology. The binding propensity of the complex with DNA obtained in in silico studies can be correlated with those from the experimental investigation. Compounds with the highest binding potential, according to the interaction energy value, were 1b, 3b, 6b and 5b. From observations of the DNA interaction ability and of the in silico assessment, no apparent DNA fragmentation was observed either on DNA extracted from the treated cancer cell line or from the zebrafish embryos.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3144

    The Extended Lateral Supraorbital Approach and Extradural Anterior Clinoidectomy Through a Frontopterio-Orbital Window : Technical Note and Pilot Surgical Series

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    BACKGROUND: Lateral approaches to treat anterior cranial fossa lesions have evolved since the first frontotemporal approach described by Dandy in 1918. We describe a less invasive approach to perform extradural anterior clinoidectomy through a lateral supraorbital (LSO) approach for anterior circulation aneurysms and anterolateral skull base lesions. METHODS: The extended LSO approach involves performing a standard lateral supraorbital craniotomy followed by drilling of the sphenoid wing and lateral wall of the orbit through the frontal bony opening of the LSO approach, without any temporal extension of the craniotomy. This creates a frontopterio-orbital window exposing the periorbita; superior, medial, and anterior aspect of the temporal dura mater; and superior orbital fissure. After unroofing the superior orbital fissure, the meningo- orbital fold is cut, and the temporal dura mater is peeled from the lateral wall of the cavernous sinus to expose the anterior clinoid process allowing a standard opening of the optic canal and anterior clinoidectomy. RESULTS: The extended LSO approach and extradural anterior clinoidectomy allowed access to 4 sphenoid wing/anterior clinoidal meningiomas, 5 anterior circulation aneurysms, 2 temporomesial lesions, and 1 orbital/cavernous sinus abscess. Postoperatively, 2 patients had transient hemiparesis, 2 patients had transient third nerve palsy, and 1 patient had minimal visual field deterioration. All patients had a modified Rankin Scale score CONCLUSION: The extended LSO approach opens a new route (frontopterio-orbital window) to perform extradural anterior clinoidectomy safely and increases surgical exposure, angles, and operability of a less invasive keyhole craniotomy (LSO approach) to treat anterior cranial fossa lesions.Peer reviewe

    Symmetry and Topology in Superconductors - Odd-frequency pairing and edge states -

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    Superconductivity is a phenomenon where the macroscopic quantum coherence appears due to the pairing of electrons. This offers a fascinating arena to study the physics of broken gauge symmetry. However, the important symmetries in superconductors are not only the gauge invariance. Especially, the symmetry properties of the pairing, i.e., the parity and spin-singlet/spin-triplet, determine the physical properties of the superconducting state. Recently it has been recognized that there is the important third symmetry of the pair amplitude, i.e., even or odd parity with respect to the frequency. The conventional uniform superconducting states correspond to the even-frequency pairing, but the recent finding is that the odd-frequency pair amplitude arises in the spatially non-uniform situation quite ubiquitously. Especially, this is the case in the Andreev bound state (ABS) appearing at the surface/interface of the sample. The other important recent development is on the nontrivial topological aspects of superconductors. As the band insulators are classified by topological indices into (i) conventional insulator, (ii) quantum Hall insulator, and (iii) topological insulator, also are the gapped superconductors. The influence of the nontrivial topology of the bulk states appears as the edge or surface of the sample. In the superconductors, this leads to the formation of zero energy ABS (ZEABS). Therefore, the ABSs of the superconductors are the place where the symmetry and topology meet each other which offer the stage of rich physics. In this review, we discuss the physics of ABS from the viewpoint of the odd-frequency pairing, the topological bulk-edge correspondence, and the interplay of these two issues. It is described how the symmetry of the pairing and topological indices determines the absence/presence of the ZEABS, its energy dispersion, and properties as the Majorana fermions.Comment: 91 pages, 38 figures, Review article, references adde

    Diseño del Módulo de Salidas Gráficas de la Carta Geoquímica

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    Fil: Marquínez García, Jorge. INDUROT: Instituto de Recursos Naturales y Ordenación del Territorio – Universidad de Oviedo; España.Fil: García Manteca, Pilar. INDUROT: Instituto de Recursos Naturales y Ordenación del Territorio – Universidad de Oviedo; España.Fil: Colina, A. INDUROT: Instituto de Recursos Naturales y Ordenación del Territorio – Universidad de Oviedo; España.Fil: Turel, Andrea Vilma. SEGEMAR: Servicio Geológico Minero Argentino; Argentina.Fil: Moser, Leda Cecilia. SEGEMAR: Servicio Geológico Minero Argentino; Argentina.Fil: Candaosa, Norberto Gabriel. SEGEMAR: Servicio Geológico Minero Argentino; Argentina.Fil: Ferpozzi, Federico Javier. SEGEMAR: Servicio Geológico Minero Argentino; Argentina.Fil: Chavez, Silvia Beatríz. SEGEMAR: Servicio Geológico Minero Argentino; Argentina

    Problematic Facebook use and problematic video gaming as mediators of relationship between impulsivity and life satisfaction among female and male gamers

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    Over the past few decades, many new technologies have emerged, such as portable computers, the internet and smartphones, which have contributed to improving the lives of individuals. While the benefits of these new technologies are overwhelmingly positive, negative consequences are experienced by a minority of individuals. One possible negative aspect of new technologies is their problematic use due to impulsive use which may lead to lower life satisfaction. The present study investigated the mediating role of problematic video gaming (PVG) and problematic Facebook use (PFU) in the relationship between impulsivity dimensions and life satisfaction as well as the relationship between impulsivity dimensions and problematic behaviors. Additionally, the potential impact of gender differences was also examined. The study comprised 673 gamers (391 females) aged 17–38 years (M = 21.25 years, SD = 2.67) selected from 1365 individuals who completed an offline survey. PFU was assessed using the Facebook Intrusion Scale, and PVG was assessed using the nine-item Internet Gaming Disorder Scale–Short-Form (IGDS9-SF). Impulsivity dimensions such as attention, cognitive instability, motor, perseverance, self-control, and cognitive complexity were assessed using the Barratt Impulsiveness Scale (BIS-11), and life satisfaction was assessed using the Satisfaction With Life Scale (SWLS). Depending on the specific impulsivity dimension, findings showed both positive and negative relationships between impulsivity and life satisfaction. Attention and perseverance subtypes of impulsivity were primarily associated with problematic behaviors. Additionally, cognitive complexity was associated with PFU among female gamers, whereas cognitive instability was associated with PVG among male gamers. Additionally, PVG was primarily associated with lower life satisfaction. However, there was no mediation effects between impulsivity dimensions and life satisfaction via PFU or PVG. These findings provide a better understanding of the relationship between problematic behaviors, life satisfaction, and impulsivity among gamers and the differences between male and female gamers
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