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Genoprotection and Cytotoxicity of Cassia surattensis Seed Extract on Vero Cell Evaluated by Comet and Cytotoxicity Assays
No full textCassia (C.) surattensis Burm. f. (Leguminosae) is a flowering plant that has been traditionally used in many countries for food and medicinal purposes. The present study was conducted to determine in vitro cytotoxicity and anti-genotoxic activity of the seed extract of C. surattensis. The cytotoxic and anti-genotoxic activities were evaluated against Vero cell line using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and comet assays. In vitro cytotoxicity evaluation demonstrated that seed extract of C. surattensis was non-cytotoxic against the Vero cells. The 50 % cytotoxic concentration (CC50) value from MTT cytotoxicity assay was 332.87 µg/ml. The seed extract of C. surattensis exhibited strong inhibitory effects against H2O2-mediated DNA damage in Vero cells as observed in Comet assay. The presence of antioxidant activity in the seed extract was associated with the antigenotoxic property of C. surattensis. In summary, the present study demonstrated an efficient antigenotoxic property of C. surattensis, which is significant for future investigation for human applications
An experimental study of PCM based finned and un-finned heat sinks for passive cooling of electronics
No full textThis experimental study determines and compares the thermal performance of unfinned and finned PCM based heat sinks. For the analysis considering pin-fins as thermal conductivity enhancer (TCE), triangular configuration is considered. It is further classified into inline and staggered pin-fin arrangements. Three popular variants of paraffin namely paraffin wax, RT-44 and RT-35HC are incorporated as phase change materials (PCMs) inside the heat sink. The volume fraction of pin-fins and PCMs are kept constant at 9% and 90% respectively. The heat input at the base of heat sinks ranges from 5 W to 8 W. The results are presented in two different cases, charging and discharging, and the analysis of temperature variation and comparison of fin arrangements in three different heat sinks with and without PCM. Further the enhancement ratios are determined to quantify the thermal performance in operation time of heat sink for passive cooling with the influence of PCMs and TCEs. The results suggest triangular inline pin-fin as the dominant heat sink geometry and RT-44 as the most efficient PCM for passive thermal management of electronic devices
Pathological Internet Use and Psychosocial Risk Factors among ASEAN University Students
No full textBackground: Pathological internet use may lead to serious psychosocial problems and dysfunction. Objectives: The purpose of the study was to investigate the prevalence of pathological internet use among undergraduate university students in five ASEAN countries in relation to sociodemographics, internet use variables, psychosocial factors, and comorbid symptoms. Methods: In a cross-sectional survey in 2015 in Indonesia (Yogyakarta), Malaysia (Kuala Lumpur), Myanmar (Yangon), Thailand (MahaSarakham), and Vietnam (Hanoi), 3240 undergraduate university students (Mean age = 20.5 years, SD = 1.6), who were randomly selected, responded to a questionnaire including the "Young Diagnostic Questionnaire for Internet Addiction" (YDQ) and other measures. Results: Overall, the prevalences of pathological internet use were 35.9% (ranging from 16.1% in Myanmar to 52.4% in Thailand), maladaptive use 34.8% and adjusted Internet users 29.9%. In multivariate logistic regression analysis, internet use variables (heavy overall Internet use, heavy Internet use for recreational purposes, and heavy smartphone use), psychosocial factors (the experience of childhood physical abuse, childhood sexual abuse, lack of social support, and poor academic performance), and comorbid symptoms (having a self-classified gambling problem, hazardous or harmful alcohol use, past 12-month drug use, severe depression, sleeping problems, having attempted a suicide, and PTSD symptoms) were found to be associated with pathological internet use. Conclusions: The study found a very high prevalence of pathological internet use; those students lacking psychosocial support and having comorbid symptoms were at the highest risk
Organizational learning: Prospective on employees readiness using information system supported learning
No full textThis study examined the theoretical, historical, philosophical prospective, perceptions and readiness of employees for information system supported learning in a learning organization. In this study, a conceptual model based on the theory of planned behaviour is used which explains how employees in learning organization conceive organizational learning using information systems. Structural Equation Mdelling (SEM) was used to analyse data from 200 employees including knowledge employees, faculty members, postgraduate working employees (internees), administrators and internees at university using convenient sampling techniques. The results show that employees’ acceptance of an Information System for organizational learning is reasonably well, based on the theory of planned behaviour. More specifically, attitude and behavioural control positively influenced their intention to accept organizational learning through an information system. The research shows that perceived ease of use and perceived usefulness affects employees’ and working employees’ attitude towards adoption of an information system for organizational learning
Prevalence, Virulence Genes and Antimicrobial Resistance Profiles of Salmonella Serovars from Retail Beef in Selangor, Malaysia
No full textThe aim of the present study was to investigate the prevalence of Salmonella spp., Salmonella Enteritidis and Salmonella Typhimurium in retail beef from different retail markets of Selangor area, as well as, to assess their pathogenic potential and antimicrobial resistance. A total of 240 retail beef meat samples (chuck = 60; rib = 60; round = 60; sirloin = 60) were randomly collected. The multiplex polymerase chain reaction (mPCR) in combination with the most probable number (MPN) method was employed to detect Salmonella spp., S. Enteritidis and S. Typhimurium in the meat samples. The prevalence of Salmonella spp., S. Enteritidis and S. Typhimurium in 240 beef meat samples were 7.50, 1.25, and 0.83%, respectively. The microbial loads of total Salmonella was found in the range of < 3 to 15 MPN/g. Eight different serovars of Salmonella were identified among the 23 isolates, and S. Agona was the predominant serovar (26.09%). Interestingly, all the Salmonella isolates were resistant to penicillin, erythromycin and vancomycin, but the sensitivity was observed for tetracycline, gentamicin and amoxicillin/clavulanic acid. All 23 isolates were resistant to at least three antibiotics. Two S. Typhimurium isolates (8.70%) exhibited the highest multiple antibiotic resistance (MAR) index value of 0.56 which shown resistance to nine antibiotics. PCR analysis of virulence genes showed that all Salmonella isolates (100%) were positive for the invA gene. Meanwhile, pefA was only identified in S. Enteritidis and S. Typhimurium. The findings in this study indicate that retail beef products tested were widely contaminated with multi-drug resistant (MDR) Salmonella and various virulence genes are present among the isolated Salmonella serovars
Effect of two-stage injection dwell angle on engine combustion and performance characteristics of a common-rail diesel engine fueled with coconut oil methyl esters-diesel fuel blends
No full textDiesel engine is widely used as prime mover due to its high thermal efficiency. Usage of renewable biodiesel in diesel engine is also widely studied due to its potential in reducing emission and as a replacement of conventional diesel. Biodiesel performance could be improved by blending it with petroleum diesel besides introducing appropriate injection strategies. In this experiment, the effect of percentage of biodiesel blends and injection strategies such as variations in start of injection (SOI) timing and dwell angle on diesel engine performance were investigated. The test engine used is four-stroke turbocharged direct injection diesel engine. Results show that exhaust emissions, engine performance and combustion characteristics are substantially affected by biodiesel blending ratio and SOI timing but slightly influenced by two-stage injection dwell angle. Biodiesel blends percentage could be raised to improve NOx and smoke emissions. Even though SOI performed at a later timing could reduce NOx emission, smoke emission increased. Dwell angle between two successive injections could be prolonged to lower the effect of the increase in smoke emission. It could also be inferred that by setting a proper SOI timing and dwell angle under two-stage injection scheme when suitable biodiesel blend is used, the engine performance could be optimized
Seroprevalence of sarcocystosis in the local communities of Pangkor and Tioman Islands using recombinant surface antigens 3 (rSAG3) of Sarcocystis falcatula
No full textObjective: To investigate the seroprevalence of Sarcocystosis in the local communities of Pangkor and Tioman islands, Malaysia, by using antigenic recombinant surface antigens 2 and 3 from Sarcocystis falcatula (rSfSAG2 and rSfSAG3) as the target proteins via Western blot and ELISA assays. Methods: SfSAG2 and SfSAG3 genes were isolated from S. falcatula and expressed in Escherichia coli expression system. A total of 348 serum samples [volunteers from both islands (n = 100), non-Sarcocystis parasitic infections patients (n = 50) and healthy donors (n = 100)] were collected and tested with purified SfSAGs in Western blot and ELISA assays to measure the seroprevalence of human sarcocystosis. Results: None of the sera in this study reacted with rSfSAG2 by Western blot and ELISA. For rSfSAG3, relatively high prevalence of sarcocystosis was observed in Tioman Island (75.5%) than in Pangkor Island (34%) by Western blot. In ELISA, the different prevalence rate was observed between Tioman Island (43.8%) and Pangkor Island (37%). The prevalence rate in other parasitic infections (amoebiasis, cysticercosis, filariasis, malaria, toxocariasis and toxoplasmosis) was 30% by Western blot and 26% by ELISA. Only 8% (by Western blot) and 10% (by ELISA) of healthy donors showed reactivity towards rSfSAG3. Conclusion: This is the first study reporting a seroprevalence of sarcocystosis in Pangkor and Tioman Islands, Malaysia. The combination of Western blot and ELISA is suitable to be used for serodiagnosis of sarcocystosis. With further evaluations, SfSAG3 can potentially be used to confirm infection, asymptomatic screening, surveillance and epidemiological studies
Recent advances on fatigue of rubber after the literature survey by Mars and Fatemi in 2002 and 2004
No full textSubjected to multiaxial mechanical loading and hostile environment, rubber experiences degradation over a period of time. Therefore, it is of utmost importance to prevent failure of rubber components during the service. As highlighted in Mars and Fatemi [Mars, W.V, Fatemi, A., 2002. A literature survey on fatigue analysis approaches of rubbers. Int. J. Fatigue 24, 949–961; Mars, W.V, Fatemi, A., 2004. Factors that affect the fatigue life of rubber: A literature survey. Rubber Chem. Technol. 77, 391–412], a large number of works focused on the durability of rubber. Furthermore, it has been expanding rapidly until today. For this reason, the present work focuses on collecting and analyzing the vast amount of works on fatigue of rubber conducted in the last 15 years since the review of Mars and Fatemi in 2002 and 2004. To this end, three bibliographic databases are consulted: Google Scholar, Scopus and Web of Science. The collected works are analyzed with the objective to identify the current and future trends and needs in the study of rubber fatigue
Marriage migration: Lived experience of foreign spouses married to Malaysian citizens
No full textMarriage migration has led to marriage migrants as a significant aspect of migration. While much of the literature on migration in the Malaysian context discusses labour migration, very little is documented on marriage migration in Malaysia, especially concerning foreign spouses’ viewpoint on their international marriage. Therefore, this paper sought to investigate and document the foreign spouses’ lived experience in several aspects of life from acquiring the spouse visa to employment to family and relationship with friends in Malaysia. Results obtained from data collected through in-depth interviews give the overview that foreign spouses experience difficulties due to their status as a ‘foreigner’. Foreign spouses’ experience of living in Malaysia is related to the idea that a ‘foreigner’ is considered socially excluded in the country, leading to difficulties. Overall, foreign spouses face many challenges living in Malaysia
Problem-solving strategies among culinary arts students in community colleges
No full textCulinary Arts is an area in Technical Vocational Education and Training (TVET) where students need to possess problem-solving skills besides having fundamental subject matter knowledge and hands-on skills required for the technical aspects of cooking. The key components for learning to solve problems are analogizing, modelling, reasoning causally, and arguing. The development of these strategies will assist students in completing numerous cognitive tasks. However, little research has been done which provide information on the level of these skills in the context of students at Community Colleges, particularly among Culinary Arts students. Drawing from a survey data, the paper examines problem-solving skills of 831 Culinary Arts students, most of whom were aged 18-24, from eleven Community Colleges offering Certificate in Culinary Arts Programme throughout Malaysia. The analysis results revealed that students had only medium level of problem-solving skills. The finding is of great significance as knowing the level of problem-solving skills of Culinary Arts students is essential before designing a suitable intervention for them. Specifically, the findings can be used to justify the design of new learning environments towards developing problem-solving skills more effectively