54 research outputs found

    تطوير منهجية تعتمد على تنقيب الأنماط المتكررة المرنة للكشف عن الأحداث الهامة في المدونات العربية المصغرة

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    Recently, Microblogs have become the new communication medium between users. It allows millions of users to post and share content of their own activities, opinions about different topics. Posting about occurring real-world events has attracted people to follow events through microblogs instead of mainstream media. As a result, there is an urgent need to detect events from microblogs so that users can identify events quickly, also and more importantly to aid higher authorities to respond faster to occurring events by taking proper actions. While considerable researches have been conducted for event detection on the English language. Arabic context have not received much research even though there are millions of Arabic users. Also existing approaches rely on platform dependent features such as hashtags, mentions, retweets etc. which make their approaches fail when these features are not present in the process. In addition to that, approaches that depend on the presence of frequently used words only do not always detect real events because it cannot differentiate events and general viral topics. In this thesis, we propose an approach for Arabic event detection from microblogs. We first collect the data, then a preprocessing step is applied to enhance the data quality and reduce noise. The sentence text is analyzed and the part-of-speech tags are identified. Then a set of rules are used to extract event indicator keywords called event triggers. The frequency of each event triggers is calculated, where event triggers that have frequencies higher than the average are kept, or removed otherwise. We detect events by clustering similar event triggers together. An Adapted soft frequent pattern mining is applied to the remaining event triggers for clustering. We used a dataset called Evetar to evaluate the proposed approach. The dataset contains tweets that cover different types of Arabic events that occurred in a one month period. We split the dataset into different subsets using different time intervals, so that we can mimic the streaming behavior of microblogs. We used precision, recall and fmeasure as evaluation metrics. The highest average f-measure value achieved was 0.717. Our results were acceptable compared to three popular approaches applied to the same dataset.حديثا،ً أصبحت المدونات الصغيرة وسيلة إتصال جديدة بين المستخدمين. فقد سمحت لملايين المستخدمين من نشر ومشاركة محتويات متعلقة بأنشطتهم وأرائهم عن مواضيع مختلفة. إن نشر المحتوى المتعلق بالأحداث الجارية في العالم الحقيقي قد جذب الناس لمتابعة الأحداث من خلال المدونات الصغيرة بدلاً من وسائل الإعلام الرئيسية. نتيجة لذلك، أصبحت هناك حاجة طارئة لكشف الأحداث من الدونات الصغيرة حتى يتمكن المستخدمون من تحديد الأحداث الجارية بشكل أسرع، أيضا والأهم من ذلك، مساعدة السلطات العليا للإستجابة بشكل سريع في عمل اللازم عند حدوث حدثا ما. في حين أنه أجريت العديد من الأبحاث على كشف الأحداث باللغة الإنجليزية، إلا أن السياق العربي لم يأخذ نصيبا وفير ا في هذا المجال، على الرغم من وجود الملايين من المستخدمين العرب. ايضا،ً العديد من المناهج الموجودة حاليا تعتمد على خصائص معتمدة على المنصة المستخدمة في البحث مثل وسم الهاشتاق، وتأشيرة المستخدم، وإعادة التغريد، إلخ. مما يجعل النهج المستخدم يتأثر سلبا في حال لم تكن هذه الخصائص موجودة أثناء عملية الكشف عن الأحداث. بالإضافة الي ذلك، المناهج التي تعتمد فقط على وجود الكلمات الأكثر استخداما لا تكشف الاحداث الحقيقية دائما لانها لا تستطيع التفرقة بين الحدث والمواضيع العامة الشائعة. في هذه الأطروحة، نقترح نهج لكشف الأحداث العربية من المدونات الصغيرة. أولاً نقوم بجمع البيانات، ثم نقوم بتجهيزها من خلال تحسينها وتقليل الشوائب فيها. يتم تحليل نص الجملة لإستخراج الأوسمة الخاصة بأجزاء الكلام. بعدها نقوم بتطبيق مجموعة من القواعد لإستخراج الكلمات الدلالية التي تشير إلي الأحدات و تسمى مشغلات الأحداث. يتم حساب عدد تكرار كل مشغل حدث، بحيث يتم الإحتفاظ على المشغلات التي لها عدد تكراراكبر من المتوسط ويتم حذف عكس ذالك. يتم الكشف عن الحدث من خلال تجميع مشغلات الأحداث المتشابهة مع بعضها. حيث نقوم بتطبيق إصدار ملائم من خوارزمية "التنقيب الناعم عن الأنماط المتكررة" على مشغلات الأحداث التي تبقت لكي يتم تجميع المتشابه منها. قمنا بإستخدام قاعدة بيانات تسمى (Evetar) لتقييم النهج المقترح. حيث تحتوي قاعدة البيانات على تغريدات تغطى عدة انواع من الأحداث العربية التي حدثت خلال فترة شهر. لكي نقوم بمحاكاة طريقة تدفق البيانات في المدونات الصغيرة، قمنا بتقسييم البيانات إلي عدة مجموعات بناءاُ على فترات زمنية مختلفة. تم استخدام كل من (Precision)، (Recall)، (F-Measure) كمقياس للتقييم، حيث كانت أعلى متوسط قيمة لل (F-Measure) تم الحصول عليها هي 0.717 . تعتبر النتائج التي حصلنا عليها مقبولة مقارنة مع ثلاث مناهج مشهورة تم تطبيقها على نفس قاعدة البيانات

    Examining teachers' role in the promotion of child-friendly environments in Zimbabwean secondary schools : implications for teacher professional development

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    Hostile school environments are a cause of concern and a perennial international educational problem. The UNICEF’s Child-Friendly Schools (CFS) approach is an international intervention meant to safeguard learners against hostile school environments. The CFS approach mandates schools to offer learners environments and conditions that uphold children’s rights and enhance their development to full potential. The purpose of this mixed methods research study, employing a concurrent triangulation design, was to explore the role of teachers in the promotion of CFS environments. Holsti’s (1970) role theory formed the theoretical framework of this study. The research questions focused on teachers’ understanding of the CFS concept, support offered, strategies employed, challenges encountered, and the implications for teacher professional development. The data collection methods were questionnaires, in-depth interviews, and document analysis with school heads, teachers and learners in the seven government urban secondary schools in Mutare district of Manicaland province in Zimbabwe. Quantitative and qualitative data were independently analysed and merged at the interpretation stage through triangulation of results. Major findings reveal that teachers have poor understanding of the CFS concept, are offered moderate support, occasionally employ viable strategies, and are hindered by various factors in the process of promoting CFS environments. The study’s implications for teacher professional development are rooted in identifying sustainable approaches that adequately equip teachers with relevant information, skills and attitudes that ensure the promotion of CFS environments

    Isolation, Purification and Structure Elucidation of New Secondary Metabolites from Terrestrial, Marine, and Ruminal Microorganisms

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    Diese Arbeit passt somit in der biologischen Bekämpfung in der Landwirtschaft gegen die Kryptogamen Krankheiten. Tatsächlich ist die Verwendung von Mikroorganismen, um gegen phytopathogene Pilze zu bekämpfen viel besser für die Umwelt und die Gesundheit des Menschen ist als der Einsatz von Pestiziden. Es vermeidet die Verschmutzung von Boden, Wasser und Nahrung. Es passt auch in den Kampf gegen die multiresistenten Bakterien und Pilze. Sechzehn Bakterien (sieben ruminale, sechs terrestrisch, zwei Marine- und ein aus dem Krankenhaus-Bereich) und zwei Pilze wurden ausgewählt und züchten den Kulturen in großem Maßstab. Die Aufarbeitung und Isolierung ihrer metabolischen Bestandteile wurden beschrieben

    Mounier-Kuhn syndrome and tracheopathia osteoplastica in the same patient with respiratory insufficiency

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    SummaryMounier-Kuhn syndrome (MKS) or tracheobronchomegaly, and tracheopathia osteoplastica (TO) are rare diseases. MKS is a clinical entity characterized by abnormal dilatation of the trachea and main bronchi. TO is a clinical and pathologic condition characterized by multiple submucosal cartilaginous and osseous nodules lining the upper respiratory tract. Some people with MKS manifest recurrent pneumonia or chronic cough with sputum production, hemoptysis or dyspnea. Occasionally, it is found in asymptomatic individuals. CT scan imaging is the key tool for the diagnosis when showing a dilatation of the trachea and main bronchi. TO is usually benign and asymptomatic, frequently diagnosed incidentally during intubation. Flexible fiberoptic bronchoscopy and laryngoscopy are the key diagnostic tools which typically demonstrate irregular spicules of submucosal bone and cartilage projecting into the tracheobronchial lumen and causing various degrees of airway obstruction. When this aspect is found bronchial biopsy is not mandatory. We report the case of a 26-year-old man with features of both MKS and TO who presented a previous history of productive cough, recurrent pneumonia and dyspnea; admitted for pulmonary infection resulting in a respiratory insufficiency. MKS was diagnosed by CT scan and TO by fiberoptic bronchoscopy. To our knowledge, this is the first time these pathologies are reported in the same patient, and our patient is the second one having MKS who presented with respiratory insufficiency

    Draft genome sequence of Streptomyces tunisialbus DSM 105760T.

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    Ayed A, Wibberg D, Zendah El Euch I, Frese M, Limam F, Sewald N. Draft genome sequence of Streptomyces tunisialbus DSM 105760T. Archives of microbiology. 2020;202:2013-2017.Streptomyces strains are well known as promising source of bioactive secondary metabolites, important in ecology, biotechnology and medicine. In this study, we present the draft genome of the new type strain Streptomyces tunisialbus DSM 105760T (=JCM 32165T), a rhizospheric bacterium with antimicrobial activity. The genome is 6,880,753bp in size (average GC content, 71.85%) and encodes 5802 protein-coding genes. Preliminary analysis with antiSMASH 5.1.2. reveals 34 predicted gene clusters for the synthesis of potential secondary metabolites, which was compared with those of Streptomyces varsoviensis NRRL ISP-5346

    Bioactive secondary metabolites from new endophytic fungus Curvularia. sp isolated from Rauwolfia macrophylla.

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    Kaaniche F, Hamed A, Abdel-Razek AS, et al. Bioactive secondary metabolites from new endophytic fungus Curvularia. sp isolated from Rauwolfia macrophylla. PLoS ONE. 2019;14(6): E0217627.Over the last decades, endophytic fungi represent a new source of pharmacologically active secondary metabolites based on the underlying assumption that they live symbiotically within their plant host. In the present study, a new endophytic fungus was isolated from Rauwolfia macrophylla, a medicinal plant from Cameroon. The fungus showed a highest homology to Curvularia sp. based on complete nucleotide sequence data generated from the internal transcribed spacer (ITS) of ribosomal DNA region. Large scale fermentation, working-up and separation of the strain extract using different chromatographic techniques afforded three bioactive compounds: 2'-deoxyribolactone (1), hexylitaconic acid (2) and ergosterol (3). The chemical structures of compounds 1-3 were confirmed by 1 and 2D NMR spectroscopy and mass spectrometry, and comparison with corresponding literature data. Biologically, the antimicrobial, antioxidant activities and the acetylcholinesterase inhibitory of the isolated compounds were studied
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