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51.
Ines Ben Chobba Amine Elleuch Imen Ayadi Lamia Khannous Ahmed Namsi Frederique Cerqueira Noureddine Drira Néji Gharsallah Tatiana Vallaeys 《Journal of Zhejiang University. Science. B》2013,14(12):1084-1099
Endophytic flora plays a vital role in the colonization and survival of host plants, especially in harsh environments, such as arid regions. This flora may, however, contain pathogenic species responsible for various troublesome host diseases. The present study is aimed at investigating the diversity of both cultivable and non-cultivable endophytic fungal floras in the internal tissues (roots and leaves) of Tunisian date palm trees (Phoenix dactylifera). Accordingly, 13 isolates from both root and leaf samples, exhibiting distinct colony morphology, were selected from potato dextrose agar (PDA) medium and identified by a sequence match search wherein their 18S–28S internal transcribed spacer (ITS) sequences were compared to those available in public databases. These findings revealed that the cultivable root and leaf isolates fell into two groups, namely Nectriaceae and Pleosporaceae. Additionally, total DNA from palm roots and leaves was further extracted and ITS fragments were amplified. Restriction fragment length polymorphism (RFLP) analysis of the ITS from 200 fungal clones (leaves: 100; roots: 100) using HaeIII restriction enzyme revealed 13 distinct patterns that were further sequenced and led to the identification of Alternaria, Cladosporium, Davidiella (Cladosporium teleomorph), Pythium, Curvularia, and uncharacterized fungal endophytes. Both approaches confirmed that while the roots were predominantly colonized by Fusaria (members of the Nectriaceae family), the leaves were essentially colonized by Alternaria (members of the Pleosporaceae family). Overall, the findings of the present study constitute, to the authors’ knowledge, the first extensive report on the diversity of endophytic fungal flora associated with date palm trees (P. dactylifera). 相似文献
52.
Mohamed Taher Amin Ahmed Khan Muhammed Burhanuddin 《International Information and Library Review》2013,45(4):337-345
This paper relates to the difficulty in retrieving precise information from big repositories of magazine articles in full text, and proposes an Extended Markup Language (XML) vocabulary for improving retrieval rates. The hypothesis tested was as follows: Magazine articles marked up with an XML vocabulary, indexed only by selected parts, give more precise search results than the same search using full text index.The study was exploratory with the following characteristics: 29 magazine articles were tested for results, 8 scholars were interviewed for defining 23 search strategies and evaluating results. The data showed that precision improved from 40.72% with full text search to 62.84% using XML markup and searching only in specific labels.Revision of the vocabulary and more testing has to be done by the library and information science community in order to obtain a valid vocabulary and provide more research results. Cultural characteristics and politics of librarians and information managers’ community are as important as technical issues in order to consider any technical proposal to be implemented successfully to achieve interoperability. 相似文献
53.
Extensive use of social networking sites by students and teachers makes educators and researchers to think whether they can be incorporated in instructional process to facilitate students’ learning. This survey-based study records and examines Pakistani pre-service teachers’ and teacher-educators’ current uses of Facebook, and their attitudes toward using Facebook for collaborative learning, and to see if there is a significant relationship between participants’ intensity of Facebook use and their attitude toward instructional use of Facebook. Results of the study indicated that pre-service teachers’ and teacher-educators’ motives for their current Facebook use are mainly limited for social purposes. Pre-service teachers’ use of Facebook is more intensified than the use of Facebook by teacher-educators. Further, pre-service teachers showed more positive attitudes toward using Facebook for collaborative learning than the attitudes of their faculty. Findings also indicated a positive relationship between participants’ Facebook intensity and their attitudes toward its use for collaborative learning. 相似文献
54.
Amal Durou Ibrahim Aref Somaya Al-Maadeed Ahmed Bouridane Elhadj Benkhelifa 《Information processing & management》2019,56(2):354-366
Handwriter identification aims to simplify the task of forensic experts by providing them with semi-automated tools in order to enable them to narrow down the search to determine the final identification of an unknown handwritten sample. An identification algorithm aims to produce a list of predicted writers of the unknown handwritten sample ranked in terms of confidence measure metrics for use by the forensic expert will make the final decision.Most existing handwriter identification systems use either statistical or model-based approaches. To further improve the performances this paper proposes to deploy a combination of both approaches using Oriented Basic Image features and the concept of graphemes codebook. To reduce the resulting high dimensionality of the feature vector a Kernel Principal Component Analysis has been used. To gauge the effectiveness of the proposed method a performance analysis, using IAM dataset for English handwriting and ICFHR 2012 dataset for Arabic handwriting, has been carried out. The results obtained achieved an accuracy of 96% thus demonstrating its superiority when compared against similar techniques. 相似文献
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The present study carries out an impact analysis of a conditional cash transfer (CCT) program for secondary-school girls in seven districts of Khyber Pakhtunkhwa province in Pakistan, including Battagram, Bonair, Hangu, Kohistan, Shangla, Tank, and Upper Dir. In 2012 we collected household-level primary data and used a probit model for quantitative analysis. Further, we conducted various focus group discussions and key informant interviews in the target areas. Results show that the chances of female schooling decrease with a rise in family size. The chances of female education increase by 1.8 and by 3.3 % if household heads and their spouses have one additional year of schooling, respectively. Better educational services and rises in family income increase the chances of female ecucation by 11 and 0.3 %, respectively. Finally, socioeconomic awareness, improved economic conditions, and CCTs increase the chances of female education by 5.2, 4.7, and 0.03 %, respectively. Overall, the stipend program (CCTs) shows a pareto improvement. Our results indicate that 35 % of girls will drop out in the absence of a stipend program. The present study recommends that to increase program effectiveness, local-level monitoring and program evaluation may be improved, delays in stipend payments to female students should be reduced, a grievance redressal mechanism for parents and guardians should be introduced, and clear synergies should be developed with other transfer programs. 相似文献
58.
Ahmed A. Abd El-Latif Bassem Abd-El-Atty Irfan Mehmood Khan Muhammad Salvador E. Venegas-Andraca Jialiang Peng 《Information processing & management》2021,58(4):102549
Blockchain plays a vital task in cybersecurity. With the exerted efforts for realising large-scale quantum computers, most current cryptographic mechanisms may be hacked. Accordingly, we need a quantum tool utilised for designing blockchain frameworks to have the ability to be executed in the level of digital computers and resist the probable attacks from both digital and quantum computers. Quantum walks may be utilised as a quantum-inspired model for designing new cryptographic algorithms. In this paper, we present a new authentication and encryption protocol based on quantum-inspired quantum walks (QIQW). The proposed protocol is utilized to build a blockchain framework for secure data transmission among IoT devices. Instead of using classical cryptographic hash functions, quantum hash functions based on QIQW are employed for linking blocks of the chain. The main advantages of the presented framework are helping IoT nodes to effectively share their data with other nodes and full control of their records. Security analysis demonstrates that our proposed protocol can defend against message attack and impersonation attacks, thus ensuring secure transmission of data among IoT devices. 相似文献
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60.
Ahmed Hassanien 《Higher Education in Europe》2007,32(2-3):135-150
The importance of group learning has increased significantly in higher education in the past two decades (Houldsworth and Mathews, 2000). The primary focus of this study is to explore the feelings and experience of students regarding group work and group assessment in higher education. The study is exploratory based on a qualitative focus group approach. Interestingly, students felt that group work is a significant method to foster the development of critical thinking through discussion, clarification of ideas, and evaluation of others' ideas. Students consider “poor communication” and “poor attendance at group meetings” as the main challenges they face when working within a group. Also, students identified “dedicated assignment seminars” as the most effective tool, which could be used to enhance the effectiveness of group work. This study reinforces the findings of previous research into group work suggesting that the experience is a generally positive one for students. Results are discussed in the context of current theoretical and empirical work on group‐based learning, education implications and areas for further research are discussed. 相似文献