Regulating Campylobacter jejuni flagellar gene expression: transcriptional and post-transcriptional mechanisms of control

The bacterial pathogen Campylobacter jejuni is the leading cause of foodborne gastroenteritis in the developed world. C. jejuni flagella are crucial virulence determinants, but the regulation of these complex organelles within different environments is not fully understood. Moreover, regulatory RNAs are important for virulence and flagellar gene expression in many prokaryotes, but their role in C. jejuni biology is unknown. The first aim was to understand flagellar regulation in acidic conditions and what effect this has on virulence. The most acidic pH C. jejuni was able to survive was pH 3.6 and acid-shock at this pH and pH 5 increased expression of a subset of flagellar genes and increased invasion of intestinal epithelial cells. The second aim of this study was to characterise the function of two paralogous small non-coding RNAs (less than 50 nucleotides), NC1 and NC4, which were identified in the C. jejuni NCTC11168 transcriptome and are predicted to regulate flagella gene expression. NC1 and NC4 expression was dependent on the flagellar sigma factor, sigma28, and post-transcriptionally regulated expression of predicted sigma54-dependent C. jejuni flagellar gene targets in an E. coli based GFP reporter system. However, microarray and phenotypic analysis showed no clear differences in gene expression between NC1/NC4 deletion and over-expression mutants compared to the wild-type strain. The conclusions are that flagellar gene expression is regulated by acidic conditions and C. jejuni invasion of intestinal epithelial cells may be primed in response to acid. In addition, the transcription of NC1 and NC4 is linked to flagella expression and they may function to post-transcriptionally regulate sigma54-dependent flagella genes in C. jejuni. Although the biological significance of NC1 and NC4 remains unknown, this is the first study to show that non-coding RNAs are potential regulators of gene expression in Campylobacter

Ensemble learning for software fault prediction problem with imbalanced data

Fault prediction problem has a crucial role in the software development process because it contributes to reducing defects and assisting the testing process towards fault-free software components. Therefore, there are a lot of efforts aiming to address this type of issues, in which static code characteristics are usually adopted to construct fault classification models.  One of the challenging problems influencing the performance of predictive classifiers is the high imbalance among patterns belonging to different classes. This paper aims to integrate the sampling techniques and common classification techniques to form a useful ensemble model for the software defect prediction problem. The empirical results conducted on the benchmark datasets of software projects have shown the promising performance of our proposal in comparison with individual classifiers

Survey on Mutation-based Test Data Generation

The critical activity of testing is the systematic selection of suitable test cases, which be able to reveal highly the faults. Therefore, mutation coverage is an effective criterion for generating test data. Since the test data generation process is very labor intensive, time-consuming and error-prone when done manually, the automation of this process is highly aspired. The researches about automatic test data generation contributed a set of tools, approaches, development and empirical results. In this paper, we will analyse and conduct a comprehensive survey on generating test data based on mutation. The paper also analyses the trends in this field

Travel Intention and Travel Behaviour in the Post-Pandemic Era: Evidence from Vietnam

Tourism is on the pathway of returning and contributes to the economic development of many countries. Understanding the decision-making process of tourism customers in the post-pandemic context is crucial for a strong recovery of the tourism sector. The paper aims to identify the determinants of travel intention and the link between travel intention and travel behaviour in the post-COVID-19 pandemic period. A total number of 431 questionnaires regarding the individual behaviour of Vietnamese travellers were collected. The empirical results reveal that electronic word of mouth, crisis management, and destination image in COVID have positive relationships with travel intention. Besides, travel intention is positively linked with the customers’ travel behaviour during the post-pandemic era. By contrast, the results do not support the conclusion regarding the relationship between risk communication, the healthcare system, non-pharmaceutical interventions and the travel intention of customers. Finally, the practical implications are included for enhancing a faster recovery process of the tourism sector

EFL LEARNERS’ PERCEPTION ABOUT PREFIXES AND SUFFIXES IN ENGLISH MORPHOLOGY

Affix knowledge is crucial for enhancing word knowledge in English morphology. Understanding the meaning of affixes not only helps develop knowledge of words but also helps master grammar. This study uses a questionnaire to assess the knowledge of prefixes and affixes and determine students' awareness of affixes. The 21 students participating in the study were all students of the 45th course, majoring in high-quality English. A survey about affix identification was given to participants, to determine their definitions and perceptions of prefixes and suffixes in English morphology. The results show that students can identify a common affix but have difficulty with strange affixes. However, to understand affixes well and be good at morphological awareness, students need to cultivate and understand the theoretical aspects of this knowledge. Another inference of these findings is favorable in the discussion part.  Article visualizations

EFFICACY OF Ageratum LEAF EXTRACT ON POSTHARVEST ROT CAUSED BY Aspergillus niger AND Colletotrichum sp. ON CHILLI FRUITS

Abstract: The damage of chilli, an important spice fruit, comes from fungal diseases caused mainly by Aspergillus niger and Colletotrichum sp. The fungi on chilli fruits would directly harm consumers’ health. Plant extracts containing bio-active compounds with antimicrobial properties could be a good possible solution to deal with the fungi. This study aims to evaluate the in vitro and in vivo efficacy of aqueous extracts from the leaves of Ageratum plants against A. niger and Colletotrichum sp. The results show that the optimal efficacy of the treatment of Ageratum leaf extract is at a concentration of 6%, with the efficacy of Ageratum leaf extract on colonial diameter at approximately 43–44% for the two fungi at 96 hours after inoculation. The 6% Ageratum leaf extract has a high efficacy (~54.23%) on limiting the development of Aspergillus rot lesions on chilli fruits 4 days after inoculation. Meanwhile, the efficacy of the extract on Colletotrichum lesions is 11.34%, lower than that of Aspergillus rot.Keywords: Ageratum leaf extract, chilli fruit, rot lesio

Influences of employees’ perceptions of corporate social responsibility on job satisfaction – A study in Ho Chi Minh City

The present study aims to explore the influences of employees’ perceptions of corporate social responsibility (CSR) on their satisfaction in different sectors. The results of the literature review show that there are three components in employees’ perceptions of CSR, including Philanthropic CSR, Ethical CSR, and Environmental CSR; and it is impacted by Perceived CSR capability, Ethical program, and Perceived fit between corporate culture and CSR activities. The research findings have confirmed the proposed hypotheses; and it is obvious that Employees’ perceptions of CSR have a significant impact on Employees’ satisfaction. From the research findings, there are some crucial points to note. Firstly, firms should design their own ethical programs. Secondly, firms should communicate their CSR practices to improve employees’ perceived CSR capabilities. These points are quite important to increase employee satisfaction

TÍNH HIỆU QUẢ CỦA MÔ HÌNH CARHART CHO CÁC CỔ PHIẾU THUỘC NHÓM NGÀNH TÀI CHÍNH, BẢO HIỂM VÀ NGÂN HÀNG – TIẾP CẬN VỚI PHƯƠNG PHÁP HỒI QUY PHÂN VỊ

Quantile regression is a very powerful tool for financial research and risk analysis when a market encounters shocks. In this paper, we use the quantile regression method to assess the parameters of the Carhart model for four factors: market return, equity size, value size, and momentum and test the validity of this model for shares in the financial, banking and insurance businesses when shocking news appears in the financial market. The results show that when the financial market is unstable, the firm capitalization (size), the book-to-market ratio, and the momentum affect the stock returns.Hồi quy phân vị là một công cụ hiệu quả trong nghiên cứu tài chính và phân tích rủi ro khi thị trường có các cú sốc. Nghiên cứu này đánh giá tác động của các nhân tố thị trường, quy mô, giá trị và xu hướng sinh lợi trong quá khứ (momentum) đến lợi suất của các cổ phiếu thuộc nhóm ngành tài chính, bảo hiểm và ngân hàng niêm yết trên sàn giao dịch chứng khoán Thành phố Hồ Chí Minh (HOSE) khi thị trường có các cú sốc bằng phương pháp hồi quy phân vị. Kết quả cho thấy khi thị trường tài chính bất ổn  chỉ có các nhân tố như chỉ số quy mô công ty, chỉ số giá trị của công ty và xu hướng sinh lợi trong quá khứ tác động tới lợi suất cổ phiếu

Parallel Mutant Execution Techniques in Mutation Testing Process for Simulink Models, Journal of Telecommunications and Information Technology, 2017, nr 4

Mutation testing – a fault-based technique for software testing – is a computationally expensive approach. One of the powerful methods to improve the performance of mutation without reducing effectiveness is to employ parallel processing, where mutants and tests are executed in parallel. This approach reduces the total time needed to accomplish the mutation analysis. This paper proposes three strategies for parallel execution of mutants on multicore machines using the Parallel Computing Toolbox (PCT) with the Matlab Distributed Computing Server. It aims to demonstrate that the computationally intensive software testing schemes, such as mutation, can be facilitated by using parallel processing. The experiments were carried out on eight different Simulink models. The results represented the efficiency of the proposed approaches in terms of execution time during the testing process

Effects of plant essential oils and their constituents on Helicobacter pylori : A Review

Essential oils (EOs) obtained from different medicinal and aromatic plant families by steam distillation have been used in the pharmaceutical, food, and fragrance industries. The plant EOs and their broad diversity of chemical components have attracted researchers worldwide due to their human health benefits and antibacterial properties, especially their treatment of Helicobacter pylori infection. Since H. pylori has been known to be responsible for various gastric and duodenal diseases such as atrophic gastritis, peptic ulcer, gastric adenocarcinoma, and mucosa-associated lymphoid tissue lymphoma, several combination antibiotic therapies have been increasingly used to enhance the eradication rate of the bacterial infection. However, in the last decades, the efficacy of the therapies has decreased significantly due to widespread emergence of multidrug resistant strains of H. pylori. In addition, side-effects from commonly used antibiotics and recurrence of the bacterial infection have drawn public health concern globally.Therefore, this review focuses on in vitro effects of plant EOs and their bioactive constituents on the growth, cell morphology and integrity, biofilm formation, motility, adhesion, and urease activity of H. pylori. Their inhibitory effects on expression of genes necessary for growth and virulence factor productions of the bacterial pathogen are also discussed. Further in vivo and clinical evaluations are required so that plant EOs and their bioactive constituents can be possibly applicable in pharmacy or as adjuvants to the current therapies of H. pylori infection