578 research outputs found

    Herz-Type Hardy Spaces for the Dunkl Operator on the Real Line

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    2000 Mathematics Subject Classification: Primary 46F12, Secondary 44A15, 44A35We introduce some new weighted Herz spaces associated with the Dunkl operator on R. Also we characterize by atomic decompositions the corresponding Herz-type Hardy spaces. As applications we investigate the Dunkl transform on these spaces and establish a version of Hardy inequality for this transform.* The authors are supported by the DGRST research project 04/UR/15-02

    An investigation of the impact of flipped instruction on EFL students’ engagement in academic writing classes: A case study of foundation students in Oman

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    Developing adequate English as a Foreign Language (EFL) academic writing skills is of paramount importance for students’ success in higher education in Oman. The traditional teaching approaches adopted in writing courses often lead to students’ disengagement, however. Although several studies have examined students and teachers’ perceptions of flipped instruction in various EFL courses, no study has examined the impact of flipping on students’ engagement in writing courses. This practice-based research project, where the instructor was the researcher, explored the impact of flipped teaching on 57 General Foundation Program (GFP) EFL learners’ behavioural, cognitive, emotional and agentic engagement in academic writing in a higher education institution in Oman, and the variations that exist in students’ engagement according to gender, age, English language proficiency and technology skills. The study adopted a mixed-methods design and used a student engagement questionnaire, focus group interviews and participant observations to collect data. Descriptive and inferential statistics and deductive and inductive analytical procedures were used to analyse the quantitative and qualitative data respectively. The study presents new practicable knowledge about the implementation and implications of flipped instruction for Omani EFL students’ engagement in academic writing at the GFP level. It proposes flipping as an instructional approach which helps to address GFP students’ lack of 4 behavioural, cognitive, emotional and agentic engagement in writing courses in the Omani context. Behaviourally, students in the flipped classroom experience increased effort, improved concentration levels, persistence, communication and collaboration, and amelioration in their attitude to class attendance. It is reasonable to conclude that learners undergo cognitive growth and develop self-regulatory strategies and meta-cognitive awareness. At the level of emotional engagement, learners initially experience negative emotions such as anger and frustration, and then more positive emotions such as contentment and increased interest in the subject as they adapt to the flipped teaching-learning model. Flipping also seems to influence students’ autonomy and ability to ask questions and express opinions. It appears, however, that this approach does not influence students’ capacity to contribute to their own learning resources and activities. This study makes a valuable contribution to knowledge about students’ engagement in EFL writing courses. It revealed that a strong positive correlation exists between students’ behavioural, cognitive and emotional engagement, and that a positive correlation exists between students’ technology skills and linguistic proficiency and several aspects of their engagement. The study demonstrated, however, that no correlation exists between gender and age and students’ engagement in the flipped classroom. Furthermore, this practice-based research indicated that although flipped instruction helps to address the problem of students’ disengagement in writing courses in our context, factors such as students’ linguistic proficiency and technology skills should be taken into consideration before implementing this instructional approach in the current setting

    Information extraction of cybersecurity concepts: An LSTM approach

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    Extracting cybersecurity entities and the relationships between them from online textual resources such as articles, bulletins, and blogs and converting these resources into more structured and formal representations has important applications in cybersecurity research and is valuable for professional practitioners. Previous works to accomplish this task were mainly based on utilizing feature-based models. Feature-based models are time-consuming and need labor-intensive feature engineering to describe the properties of entities, domain knowledge, entity context, and linguistic characteristics. Therefore, to alleviate the need for feature engineering, we propose the usage of neural network models, specifically the long short-term memory (LSTM) models to accomplish the tasks of Named Entity Recognition (NER) and Relation Extraction (RE).We evaluated the proposed models on two tasks. The first task is performing NER and evaluating the results against the state-of-the-art Conditional Random Fields (CRFs) method. The second task is performing RE using three LSTM models and comparing their results to assess which model is more suitable for the domain of cybersecurity. The proposed models achieved competitive performance with less feature-engineering work. We demonstrate that exploiting neural network models in cybersecurity text mining is effective and practical. - 2019 by the authors.This publication was made possible by the support of Qatar University and DISP laboratory (Lumi?re University Lyon 2, France).Scopu

    Approaches in topical ocular drug delivery and developments in the use of contact lenses as drug-delivery devices

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    The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Drug-delivery approaches have diversified over the last two decades with the emergence of nanotechnologies, smart polymeric systems and multimodal functionalities. The intended target for specific treatment of disease is the key defining developing parameter. One such area which has undergone significant advancements relates to ocular delivery. This has been expedited by the development of material advancement, mechanistic concepts and through the deployment of advanced process technologies. This review will focus on the developments within lens-based drug delivery while touching on conventional and current methods of topical ocular drug delivery. A summary table will provide quick reference to note the key findings in this area. In addition, the review also elucidates current theranostic and diagnostic approaches based on ocular lenses

    Convolution Operators and Bochner-Riesz Means on Herz-Type Hardy Spaces in the Dunkl Setting

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    We study the Dunkl convolution operators on Herz-type Hardy spaces ℋα,2p and we establish a version of multiplier theorem for the maximal Bochner-Riesz operators on the Herz-type Hardy spaces ℋα,∞p

    Sequential versus combination chemotherapy for the treatment of advanced colorectal cancer (FFCD 2000-05): an open-label, randomised, phase 3 trial

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    BACKGROUND: The optimum use of cytotoxic drugs for advanced colorectal cancer has not been defined. Our aim was to investigate whether combination treatment is better than the sequential administration of the same drugs in patients with advanced colorectal cancer. METHODS: In this open-label, randomised, phase 3 trial, we randomly assigned patients (1:1 ratio) with advanced, measurable, non-resectable colorectal cancer and WHO performance status 0-2 to receive either first-line treatment with bolus (400 mg/m(2)) and infusional (2400 mg/m(2)) fluorouracil plus leucovorin (400 mg/m(2)) (simplified LV5FU2 regimen), second-line LV5FU2 plus oxaliplatin (100 mg/m(2)) (FOLFOX6), and third-line LV5FU2 plus irinotecan (180 mg/m(2)) (FOLFIRI) or first-line FOLFOX6 and second-line FOLFIRI. Chemotherapy was administered every 2 weeks. Randomisation was done centrally using minimisation (minimisation factors were WHO performance status, previous adjuvant chemotherapy, number of disease sites, and centre). The primary endpoint was progression-free survival after two lines of treatment. Analyses were by intention-to-treat. This trial is registered at ClinicalTrials.gov, NCT00126256. FINDINGS: 205 patients were randomly assigned to the sequential group and 205 to the combination group. 161 (79%) patients in the sequential group and 161 (79%) in the combination group died during the study. Median progression-free survival after two lines was 10·5 months (95% CI 9·6-11·5) in the sequential group and 10·3 months (9·0-11·9) in the combination group (hazard ratio 0·95, 95% CI 0·77-1·16; p=0·61). All six deaths caused by toxic effects of treatment occurred in the combination group. During first-line chemotherapy, significantly fewer severe (grade 3-4) haematological adverse events (12 events in 203 patients in sequential group vs 83 events in 203 patients in combination group; p<0·0001) and non-haematological adverse events (26 events vs 186 events; p<0·0001) occurred in the sequential group than in the combination group. INTERPRETATION: Upfront combination chemotherapy is more toxic and is not more effective than the sequential use of the same cytotoxic drugs in patients with advanced, non-resectable colorectal cancer. FUNDING: Sanofi-Aventis France

    The Bessel-Struve intertwining operator on ℂ

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    We give a description of all transmutation operators from the Bessel-Struve operator to the second-derivative operator. Next we define and characterize the mean-periodic functions on the space ℋ of entire functions and we characterize the continuous linear mappings from ℋ into itself which commute with Bessel-Struve operator

    400 ans d'exploration botanique en zone méditerranéenne algérienne Une histoire méconnue et inachevée

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    Cet article fait une mise au point quasi exhaustive de l'exploration botanique en Algérie. Exploration couronnée, en 1962, par la publication de la flore de Quézel et Santa, dont la révision reste toujours d'actualité

    Caractérisation des émergences du piémont de jbel Ayachi : contrôle structural et impact du changement climatique

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    Le massif calcaire de jbel Ayachi (Haute Atlas de Midelt), montre une structure complexe liée aux calcaires karstiques du Lias. Les nombreuses sources du relief indiquent l’existence d’importantes réserves d'eau. Dans le but de caractériser cet aquifère et de préciser les relations hydrodynamiques entre les zones de recharges et les sources de l’aquifères, une méthodologie a été utilisée. Elle comporte la synthèse des données géologiques, l’utilisation des techniques d’analyse structurale couplées aux études des débits et des chroniques de pluies. Les résultats de cette étude ont permis d’établir une comparaison des conditions d’émergence des deux sources (Ain Tatiouine, Ain Anzar Oufounès) et de l’évolution de leurs paramètres hydrodynamiques. Et une bonne corrélation entre les zones de recharges et les zones d’émergences. Elles permettront, à terme d’établir l’influence des changements climatiques sur les comportements hydrodynamiques de ces émergences.Mots-clés : sources, jbel Ayachi, Haute Atlas, lias, calcaire, karstique, débit, pluie, hydrodynamique, recharge, fissuration, fluctuations, émergence.Characterization of emergences piedmont of Jbel Ayachi. Structural control, and impact of climate changeThe calcareous solid mass of jbel Ayachi (High atlas of Midelt), shows a structure complex related to karstic limestones of Lias. The many sources of the relief indicate the existence of important water reserves. In order to characterize the aquifer and to clarify the relationship between hydrodynamic areas and springs of recharge of the aquifers, a methodology was used. It involves the synthesis of geological data, the use of structural analysis techniques coupled with studies of flow and chronic rain. The results of this study were used to compare the conditions of emergence of the two springs (Ain Tatiouine, Ain Anzar Oufounès) and changes in their hydrodynamic parameters. And good correlations between areas of recharge areas and emergences. They will eventually establish the influence of climate change on the hydrodynamic behavior of these emergences.Keywords : spring, Jbel Ayachi, High Atlas, lias, limestone, karst, flow, rain, hydrodynamics, recharge, cracking, fluctuations, emergence
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