142 research outputs found
Refusal strategies in L1 and L2 among undergraduate Egyptian students
The current study investigated the refusal strategies realized by young adult Egyptian students in their L1 (Egyptian Arabic) and L2 (English). The study also explored the socio-pragmatic features of Egyptian refusals in terms of power and distance as well as the pragmatic transfer in the students’ L2 refusals. 2270 cases of refusal were collected by means of a Discourse Completion Task (DCT) and field notes. The sample consisted of 200 DCTs (collected from 100 students in L1 and L2) and 60 instances of refusals extracted from field notes collected by the researcher. The data were analyzed according to an adaptation of the taxonomy of refusal strategies by Beebe, Takahashi and Uliss-Weltz (1990). The findings reflected a great amount of positive pragmatic transfer as most of the students refusals were indirect refusals. The strategies that were mainly used by students were statements of explanations, statements of alternatives, and statements of regret. In addition, adjuncts to refusals such as gratitude and positive opinion were used to refuse the requests and offers of higher and equal power. Furthermore, the results also showed an amount of negative pragmatic transfer in students’ L2 refusals as a result of both pragma-linguistic and socio-pragmatic failures. Implications and recommendations for future research were suggested based on the given results
Guidelines for a short course on Egyptian marine officers\u27 responsibilities for the marine environment
Egypt has a strategic geographical location straddling both the Mediterranean and the Red Seas that constitute two of the major enclosed coastal seas in the world. Egyptian coasts have a total length of about 1630 Ian in the Mediterranean and Red Seas. A large part of the coastal areas in Egypt is contaminated with oil from various sources. Shipping activity contributes significantly to the current situation regarding oil pollution of the country\u27s territorial waters. The reasons for oil pollution in Egyptian waters are many, and Egyptian marine officers play a significant role in contributing to the pollution of the marine environment. This research examined the causes behind the prevailing lack of knowledge among Egyptian marine officers regarding oil pollution matters. The methodology adopted was the development of a questionnaire that was distributed to a sample of marine officers represented the overall situation among Egyptian marine officers. Through an analysis of the completed responses, a better understanding of the causes of oil pollution in Egyptian water was revealed. The analysis revealed that the lack of knowledge relating to international conventions, especially MARPOL 73/78, reflected the area of greatest ignorance. The potential damage resulting from oil spills holds the second position of greatest ignorance. The significance of ship/shore safety check lists and the existence of oil spill contingency plans occupy the third and forth positions respectively. This research has also focused on explaining the importance of each subject area identified for inclusion in the short course. It concludes with a recommended model for a short course curriculum aiming to assist those marine officers to have a greater appreciation for the importance of protecting the marine environment from oil pollution from ships
Building Secure and Fast Cryptographic Hash Functions Using Programmable Cellular Automata
Cryptographic hash functions have recently brought an exceptional research interest. With the increasing number of attacks against the widely used functions as MD5, SHA-1 and RIPEMD, the need to consider new hash functions design and conception strategies becomes crucial. In this paper, we propose a fast and efficient hash function using programmable cellular automata that are very suitable for cryptographic applications due to their chaotic and complex behavior derived from simple rules interaction. The proposed function is evaluated using several statistical tests, while obtained results demonstrate very admissible cryptographic properties such as confusion/diffusion capability and high sensitivity to input changes. Furthermore, the hashing scheme can be easily implemented through software or hardware, so it provides very competitive running performances
Dynamic Detection of Software Defects Using Supervised Learning Techniques
Software testing is the main step of detecting the faults in Software through executing it. Therefore, it is substantial to predict the faults that may happen while executing the software to maintain the existence of the software. There are different techniques of artificial intelligence that are utilized to predict future defects. The Machine learning is one of the most significant technique that used to build predicting models. In this paper, conducted a systematic review of the supervised machine learning techniques which are used for software defect prediction and evaluated the performance. Thus, using five state-of-the-art supervised machine learning (classifiers), for the evaluation, several of the data are used to predict software fault. In addition to, compared the performance of these classifiers with various parameters. After that, proceeds many experiments to improve the efficiency of the prediction of the defect through modifying the default parameters of the classifier. The results showed the ability of supervised machine learning algorithms to classify classes as bugs or not bugs. Thus, using supervised machine learning models for predicting software bugs is better than the traditional statistical models. Additionally, using PCA never noticeable impact on prediction systems performance while modifying the default parameters positively impact classifier values, especially with Artificial Neural Network (ANN).The main finding of this paper is gained through the application of Ensemble Learning methods, whereas Bagging achieves 95.1% accuracy with Mozilla dataset and Voting achieves 93.79% accuracy with kc1 dataset
SECONDARY METABOLITES FROM RICE CULTURE OF ASPERGILLUS SP. ISOLATED FROM MELALEUCA SUBULATA (CHEEL) CRAVEN LEAVES AND THEIR ANTICANCER ACTIVITY
Objective: Aspergillus fungus is a rich source of natural products with broad biological activities. This study was conducted to identify secondary metabolites from the rice culture of Aspergillus species isolated from Melaleuca subulata leaves and evaluated their anticancer activity.
Methods: Ethyl acetate extract was fractionated on silica gel and Sephadex columns. Structures of the compounds were established using physical and chemical methods. Cytotoxic activities of the extract and pure compounds against two human cancer cell lines (Mcf-7and Hep G2) were evaluated using microculture tetrazolium assay as well as the mode of the cytotoxicity was evaluated. Molecular docking studies have been performed using the Hsp 90 enzyme as an anticancer target.
Results: Methyl linoleate (1), arugosin C (2), ergosterol (3), sterigmatocystin (4), diorcinol (5), alternariol-5-O-methyl ether (6), averufin (7), averufanin (8), and alternariol (9) were identified from ethyl acetate extract. All tested compounds exhibit week activity against MCF-7 and Hep G2 cell lines but a mixture of compounds 7 and 8 is considered to be more active towards both MCF-7 and Hep G 2 in comparison to other compounds. Compound 4 exhibits moderate activity against Hep G2 only as well as the ethyl acetate extract exerts moderate activity against MCF-7 cell line Moreover, compound 4 and a mixture of 7 and 8 caused a decrease in the number of Hep G2 cancer cells due to apoptotic and necrotic processes. Most active anticancer candidates 7 and 8 showed binding to the active site similar to geldanamycin reference ligand.
Conclusion: Secondary metabolites identified from Aspergillus sp. and their anticancer activity were evaluated. Molecular docking suggested active candidates as Hsp 90 inhibitors
Risk Factors Associated With Hip Fractures among Adult People in Babylon City, Iraq
BACKGROUND: The fractures of hip joint considered as a serious problem in public health in the medical and socioeconomic issues, the incidence of the fracture neck femur is significantly increased with the increment of general population life span.
AIM: The goal of this study is to highlight and focus on the most important risk factor for the hip fractures in our Babylon society, and to improve our understanding of the medical and social aspects of these predisposing factors.
PATIENTS AND METHODS: A case-control study of older adults (above 60 years old). The study was done on tow samples. First, one consisting of 75 cases those having fracture neck femur considered as cases, and second sample as a control group, consisting of 150 people as a healthy control group having no fracture. A pre-tested questionnaire was prepared to collect data from both samples; the questionnaire included demographic data and information about potential risk factors of hip fracture.
RESULTS: Most of the people in the study samples in both groups were, married women, housekeepers, illiterate and from urban dwellers. There was highly significant association between case-control groups regarding, Continuous using of medication such as cortisone which was found to be a potential risk factor of hip fracture (Unadjusted OR = 3.636), low income was positively associated risk factor of hip fracture in this study (OR = 2.377), low milk intake, low sun exposure, tobacco smoking were positively associated with this health problem (OR = 1.794), while physical exercise was protective factor (OR = 0.489).
CONCLUSION: The highest risk factors associated with increased occurrence of hip fracture were using cortisone, Osteoporosis, tobacco smoking, consuming soft drinks, and less exposure to sunlight
Supervised Learning Algorithms in Educational Data Mining: A Systematic Review
The academic institutions always looking for tools that improve their performance and enhance individuals outcomes. Due to the huge ability of data mining to explore hidden patterns and trends in the data, many researchers paid attention to Educational Data Mining (EDM) in the last decade. This field explores different types of data using different algorithms to extract knowledge that supports decision-making and academic sector development. The researchers in the field of EDM have proposed and adopted different algorithms in various directions. In this review, we have explored the published papers between 2010-2020 in the libraries (IEEE, ACM, Science Direct, and Springer) in the field of EDM are to answer review questions. We aimed to find the most used algorithm by researchers in the field of supervised machine learning in the period of 2010-2020. Additionally, we explored the most direction in the EDM and the interest of the researchers. During our research and analysis, many limitations have been examined and in addition to answering the review questions, some future works have been presented
Assessment of Chronic Sublethal Effects of Imidacloprid on Honey Bee Colony Health
Funding for Open Access provided by the UMD Libraries Open Access Publishing Fund.Here we present results of a three-year study to determine the fate of imidacloprid residues in hive matrices and to assess chronic sublethal effects on whole honey bee colonies fed supplemental pollen diet containing imidacloprid at 5, 20 and 100 μg/kg over multiple brood cycles. Various endpoints of colony performance and foraging behavior were measured during and after exposure, including winter survival. Imidacloprid residues became diluted or non-detectable within colonies due to the processing of beebread and honey and the rapid metabolism of the chemical. Imidacloprid exposure doses up to 100 μg/kg had no significant effects on foraging activity or other colony performance indicators during and shortly after exposure. Diseases and pest species did not affect colony health but infestations of Varroa mites were significantly higher in exposed colonies. Honey stores indicated that exposed colonies may have avoided the contaminated food. Imidacloprid dose effects was delayed later in the summer, when colonies exposed to 20 and 100 μg/kg experienced higher rates of queen failure and broodless periods, which led to weaker colonies going into the winter. Pooled over two years, winter survival of colonies averaged 85.7, 72.4, 61.2 and 59.2% in the control, 5, 20 and 100 μg/kg treatment groups, respectively. Analysis of colony survival data showed a significant dose effect, and all contrast tests comparing survival between control and treatment groups were significant, except for colonies exposed to 5 μg/kg. Given the weight of evidence, chronic exposure to imidacloprid at the higher range of field doses (20 to 100 μg/kg) in pollen of certain treated crops could cause negative impacts on honey bee colony health and reduced overwintering success, but the most likely encountered high range of field doses relevant for seed-treated crops (5 μg/kg) had negligible effects on colony health and are unlikely a sole cause of colony declines
The Effect of use of Vaginal Lactobacillus Rhamnosus for Prevention of Recurrence of Vulvovaginal Candidiasis: A randomized controlled trial
Objectives:The study aims to investigate the role of vaginal administration of Lactobacillus Rhamnosus after vaginal miconazole for prevention of recurrence among women with vulvovaginal candidiasis (VVC).Materials and Methods:A randomized clinical study was done in Women Health Hospital–Assiut University–Egypt. All women presented with symptoms suggestive of VVC to the clinic had been examined and approached for participation. Eligible participants were randomly assigned to one of three groups: Group (A) received lactobacillus containing vaginal capsules daily for one week postmenstrual. Group (B) received vaginal miconazole 400 mg once daily for 3days at bedtime postmenstrual. Group (C) received vaginal miconazole 400 mg once daily for 3 days at bedtime postmenstrual followed by lactobacillus containing vaginal capsules twice daily for one week. The primary outcome was to study the rate of recurrence of symptoms after 1, 3, 6 months of treatment. Results:During the study period, 202 participants with recurrent VVC were approached to participate in this study. No significant differences were found between the three study groups with regards patients’ age, residence, parity. After 1 month, symptoms of VVC recurred in 68.4%, 24.6% and 17.2% of women in group A, B, C consecutively. The recurrence rate increases after 3 months to become 87.5%, 60% and 33.3% consecutively in the three groups. Finally after 6 months, 94.4%, 88.7%, and 44.6% of women in group A, B, C consecutively suffered from RVVC. The recurrence rate is lower in group C (combination group) with statistically significant difference (p=0.0001).Conclusions:Vaginal administration of Lactobacillus Rhamnosus twice daily for 1 week after vaginal miconazole leads to vaginal colonization and associated at 6 months follow up with decrease the recurrence rate of VVC
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