4,438 research outputs found

    Relations entre contrôle de la source en mémoire épisodique et fonctionnement exécutif dans le vieillissement normal

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    Les travaux sur le vieillissement cognitif normal suggèrent l\u27existence de difficultés pour le contrôle de la source en mémoire épisodique, en lien avec une diminution du contrôle exécutif. Néanmoins, les approches utilisées dans la littérature ne permettent pas de savoir si toutes les dimensions du contrôle de la source se dégradent avec l\u27âge, ni de savoir si certains processus exécutifs sont plus impliqués que d\u27autres dans la diminution du contrôle de la source. Dans ce travail, nous avons étudié l\u27effet de l\u27âge sur le contrôle de la source à partir de tâches simples et originales évaluant le contrôle interne, le contrôle externe et le contrôle de la réalité. Plusieurs mécanismes exécutifs ont aussi été évalués. Les tâches ont été proposées à 24 participants jeunes et 22 participants âgés en bonne santé appariés par le sexe et le niveau de vocabulaire au Mill Hill. Les résultats ont montré une détérioration du contrôle de la source en mémoire épisodique, surtout pour le contrôle externe, chez les participants âgés. Ce déclin était très lié à la diminution des performances au test de Stroop. Il semblerait donc que le vieillissement normal s\u27accompagne d\u27une baisse assez globale du contrôle de la source en mémoire épisodique et que cette baisse s\u27expliquerait principalement par l\u27altération des compétences inhibitrices

    Arabic dialect identification in the context of bivalency and code-switching

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    In this paper we use a novel approach towards Arabic dialect identification using language bivalency and written code-switching. Bivalency between languages or dialects is where a word or element is treated by language users as having a fundamentally similar semantic content in more than one language or dialect. Arabic dialect identification in writing is a difficult task even for humans due to the fact that words are used interchangeably between dialects. The task of automatically identifying dialect is harder and classifiers trained using only n-grams will perform poorly when tested on unseen data. Such approaches require significant amounts of annotated training data which is costly and time consuming to produce. Currently available Arabic dialect datasets do not exceed a few hundred thousand sentences, thus we need to extract features other than word and character n-grams. In our work we present experimental results from automatically identifying dialects from the four main Arabic dialect regions (Egypt, North Africa, Gulf and Levant) in addition to Standard Arabic. We extend previous work by incorporating additional grammatical and stylistic features and define a subtractive bivalency profiling approach to address issues of bivalent words across the examined Arabic dialects. The results show that our new methods classification accuracy can reach more than 76% and score well (66%) when tested on completely unseen data

    University of Essex at the TAC 2011 Multilingual Summarisation Pilot

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    We present the results of our Arabic and English runs at the TAC 2011 Multilingual summarisation (MultiLing) task. We partic- ipated with centroid-based clustering for multi- document summarisation. The automatically generated Arabic and English summaries were evaluated by human participants and by two automatic evaluation metrics, ROUGE and Au- toSummENG. The results are compared with the other systems that participated in the same track on both Arabic and English languages. Our Arabic summariser performed particularly well in the human evaluation

    The interplay between tissue growth and scaffold degradation in engineered tissue constructs

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    In vitro tissue engineering is emerging as a potential tool to meet the high demand for replacement tissue, caused by the increased incidence of tissue degeneration and damage. A key challenge in this field is ensuring that the mechanical properties of the engineered tissue are appropriate for the in vivo environment. Achieving this goal will require detailed understanding of the interplay between cell proliferation, extracellular matrix (ECM) deposition and scaffold degradation.\ud \ud In this paper, we use a mathematical model (based upon a multiphase continuum framework) to investigate the interplay between tissue growth and scaffold degradation during tissue construct evolution in vitro. Our model accommodates a cell population and culture medium, modelled as viscous fluids, together with a porous scaffold and ECM deposited by the cells, represented as rigid porous materials. We focus on tissue growth within a perfusion bioreactor system, and investigate how the predicted tissue composition is altered under the influence of (i) differential interactions between cells and the supporting scaffold and their associated ECM, (ii) scaffold degradation, and (iii) mechanotransduction-regulated cell proliferation and ECM deposition.\ud \ud Numerical simulation of the model equations reveals that scaffold heterogeneity typical of that obtained from ÎĽCT scans of tissue engineering scaffolds can lead to significant variation in the flow-induced mechanical stimuli experienced by cells seeded in the scaffold. This leads to strong heterogeneity in the deposition of ECM. Furthermore, preferential adherence of cells to the ECM in favour of the artificial scaffold appears to have no significant influence on the eventual construct composition; adherence of cells to these supporting structures does, however, lead to cell and ECM distributions which mimic and exaggerate the heterogeneity of the underlying scaffold. Such phenomena have important ramifications for the mechanical integrity of engineered tissue constructs and their suitability for implantation in vivo

    Strukturna i elektronska svojstva bbc selena pod visokim tlakom

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    Full-potential linearized augmented plane-wave method (FP-LAPW) within the density functional theory is applied to study the structural and electronic properties of selenium in the bcc phase at high pressures. We used local density approximation with and without generalized gradient correction based on exchange-correlation energy optimization. We have determined the full set of first-order elastic constants, which have not been established earlier experimentally or theoretically. The elastic moduli show linear dependence on pressure. The calculated energy allowed us to investigate several structural properties such as lattice parameter, bulk modulus and its pressure derivative. Our calculated lattice parameter is found to be in reasonable agreement with experimental result. The electronic band structure and the density of states at various pressures are also calculated to show that there is a possibility for these compounds to become metallic at high pressures. Further, we have calculated the electronic specific heat coefficient, which decreases with the increase of pressure.Primjenom metode lineariziranih proširenih ravnih valova s potpunim potencijalom, u okviru teorije funkcionala gustoće, proučavali smo strukturna i elektronska svojstva selena u bcc fazi na visokim tlakovima. Primijenili smo približenje lokalne gustoće sa i bez poopćene gradijentne popravke primjenom optimizacije energije korelacije i izmjene. Odredili smo potpun skup elestičnih konstanti prvog reda koje ranije nisu bile određene ni eksperimentalno ni teorijski. Moduli eleastičnosti pokazuju linearnu ovisnost o tlaku. Na osnovi izračunatih energija mogli smo istražiti više strukturnih svojstava, kao što su parametar rešetke, volumni modul stlačivosti i njegova derivacija po tlaku. Naš izračunat parametar rešetke je u dobrom slaganju s eksperimentalnim rezultatom. Također smo izračunali strukturu elekronskih vrpci i gustoće stanja da bismo ukazali na mogućnost da na visokim tlakovima selen u fazi bcc može postati metal. Nadalje, izračunali smo koeficijent elektronske specifične topline koji se smanjuje s porastom tlaka

    THE IMPACT OF TRUS IN DETECTION OF PROSTATE CANCER IN GEZIRA, SUDAN

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    Introduction:  Prostate cancer (P ca) is the most commonly diagnosed visceral cancer worldwide. It is the second cause of cancer death in men. Objective: To study the impact of introducing transrectal ultrasound (TRUS)-guided biopsy in detection of Prostate cancer in Central Sudan. Methods: This was a retrospective hospital based study. A review was done for data of prostate cancer patients treated in the Institute of Nuclear Medicine and Oncology & Gezira Hospital of Renal Diseases & Surgery (GHRD&S), Wad Medani, Sudan during the years 2002-2007. Comparison was done between the data available before and after introduction of trans rectal ultrasound biopsy, TRUS in 2005. Results: Prostate cancer cases were contributing for only 8% of all cancers during the time period before TRUS introduction. During the year 2007 the figure increased to 14%. The leading cancer in males now is the P ca. previously it was the third registered cancer before TRUS was introduced. The detection of new cases per year increased dramatically after the introduction of TRUS service. Conclusion and recommendation: Prostate cancer was found to be the most common cancer in Sudanese males. TRUS guided biopsy contributed significantly in early detection of prostate cancer in this region. Distribution of this facility with adequate training of the staff optimizes a proper and early detection of prostate cancer

    Lexical, cultural and grammatical translation problems encountered by senior Palestinian EFL learners at the Islamic University of Gaza, Palestine

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    The purpose of this study is to investigate, analyze and classify the lexical, cultural and grammatical problems encountered by senior Palestinian EFL university learners in their English-Arabic translations and to find out any gender differences regarding their translation problems. The translation test used in this empirical study consisted of 18 texts covering three types: descriptive, argumentative and instructional. These texts were translated by 28 students chosen randomly from the Department of English at the Islamic University of Gaza. The students also responded to a questionnaire regarding the level of difficulty of each translated text. The analysis of students’ translations was based on the linguistic judgments of a group of Arabic specialists including the researcher’s assessment, a rater’s assessment, the target readership assessment and the work of a professional translator. The results showed that Palestinian EFL student translators committed errors on three levels: lexical, cultural and grammatical. The most frequent errors were grammatical errors, followed by lexical errors and cultural errors. Grammatical errors were mainly attributed to linguistic differences between English and Arabic as well as students’ lack of linguistic competence. Lexical errors were mainly attributed to students’ tendency to adopt literal translation and their total dependence on existing bilingual dictionaries. Cultural errors on the other hand resulted from students’ unfamiliarity with the source language culture and lack of knowledge of the target culture. The study also revealed that male students committed more errors than female students at lexical and grammatical levels. However, male students committed fewer errors than female students at the cultural level. The results of the questionnaire showed that argumentative texts were regarded by students as the most difficult, followed by instructional and finally descriptive texts
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