Chlorella vulgaris triggers apoptosis in hepatocarcinogenesis-induced rats

Chlorella vulgaris (CV) has been reported to have antioxidant and anticancer properties. We evaluated the effect of CV on apoptotic regulator protein expression in liver cancer-induced rats. Male Wistar rats (200∼250 g) were divided into eight groups: control group (normal diet), CDE group (choline deficient diet supplemented with ethionine in drinking water to induce hepatocarcinogenesis), CV groups with three different doses of CV (50, 150, and 300 mg/kg body weight), and CDE groups treated with different doses of CV (50, 150, and 300 mg/kg body weight). Rats were sacrificed at various weeks and liver tissues were embedded in paraffin blocks for immunohistochemistry studies. CV, at increasing doses, decreased the expression of anti-apoptotic protein, Bcl-2, but increased the expression of pro-apoptotic protein, caspase 8, in CDE rats, which was correlated with decreased hepatoctyes proliferation and increased apoptosis as determined by bromodeoxy-uridine (BrdU) labeling and terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL) assay, respectively. Our study shows that CV has definite chemopreventive effect by inducing apoptosis via decreasing the expression of Bcl-2 and increasing the expression of caspase 8 in hepatocarcinogenesis-induced rats. Project supported by Department of Biochemistry, Faculty of Medicine, UKM Medical Center, Universiti Kebangsaan Malaysia, and the Malaysian Ministry of Science and Technological Innovation (MOSTI)     

建立知识社会

人类社会正经历着向知识社会的转变;知识正日益成为经济发展和社会进步的核心因素.身处全球迈向知识社会的进程之中,我们目睹和亲历着世界性的合作、竞争、流动和创新.技术变革无疑是这一进程的强大驱动力之一;而在技术不断取得极大进步,知识与信息以空前的数量产生和极快的速度传播的同时,也存在着知识鸿沟或数字鸿沟现象.     

E-print depositing behavior of physicists and astronomers: An intradisciplinary study

This article investigates the e-print depositing behavior of physicists and astronomers. Fifty-six PhD students and staff at the Department of Physics and Astronomy at the University College London were interviewed. A survey was also carried out (47.1% response rate). The study investigates the relation between variables such as research area, type of research (theoretical, experimental and so on), and the amount of reading on the patterns of e-print depositing. The findings showed that clear intradisciplinary differences exist among different subfields of physics and astronomy.     

Distributed cruise control of high-speed trains

In this work, the cruise control problem of high-speed trains’ movements is investigated. Both cases of a single high-speed train and multiple high-speed trains are under consideration. Different with most existing studies where the centralized control or the decentralized control methods are adopted based on a single point mass model of the train, in this paper, a distributed control mechanism is proposed by virtue of the graph theory, and the high-speed train’s model is built as a cascade of point masses connected by flexible couplers. For a single high-speed train, the neighboring cars interact through the coupling force with each other, which can be described by a connected topological graph by regarding each car as a node. Besides, the speed information communication among the cars is considered to be described by another directed topological graph. A distributed control strategy is then developed, with which all the cars of a train track a desired speed asymptotically and the neighboring cars keep a safety distance from each other. For the multiple high-speed trains running on a railway line, the in-train force interaction topology and the speed information communication topology of all the trains are more complex than those of a single train. A new cluster consensus technique is developed, by which a distributed control law is designed. Under the control law, the trains can track the desired speeds asymptotically, the headway distance between adjacent trains and the distance between the neighboring cars of a train can be kept in appropriate ranges. Finally, simulations are provided to illustrate the effectiveness of the obtained theoretical results.     

Programme Quality Assessment by the Implication of Variable Entry Qualifications on Students' Performance

Since its inception 30 years ago, the then Department of Engineering Science, Institut Teknologi MARA (ITM) was given the responsibility of preparing all the students in the first year engineering programmes by giving enough knowledge in basic science and mathematics. The nation's vision to become a fully‐industrialised economy by the year 2020 required all institutes of higher learning (IHLs) in Malaysia to increase their intake of students in the science and technology courses, especially in engineering. However, at the upper secondary education level, students have the freedom to choose between the science‐based or non‐science combination of subjects. This has led to a dearth of science‐based students enrolling in IHLs. Because ITM believes that it is possible to educate individuals from various backgrounds, the engineering courses are open to students with a variety of academic qualifications. Special bridging courses were designed and created for such students since late 1996. The success or failure of the new courses can be assessed after the students have gone through the proper first year engineering courses which consist of Mathematics, Physics and Chemistry. This paper reports on a pilot study on the pioneer groups of students with variable entry qualifications to assess the effectiveness of the courses. The study involved the analysis of the students’ examination results as a performance indicator, and it was found that the bridging programme for non‐science students needed to be redesigned. It is also proposed that to improve the quality of the programme, and hence students’ performance, a regular review be conducted, student support activities be continued and to expand the use of self‐study materials.     

Subtractive Schooling and Identity: A Case Study of Ethnic Minority Students in Vietnam

This article examines the impact of subtractive schooling, including language use in education, on the identity of a group of ethnic minority students in Central Highlands of Vietnam. Drawing on semistructured interview data, a deeper look is taken into the ways in which these students identify themselves with their languages, cultures, and social relations. Findings reveal that the subtractive power of the school language and the institutional milieu profoundly influenced their identity construction by creating the conditions for (a) the devaluation of their language and cultural identity as a consequence of the invasion of their sociocultural territory by the dominant language and culture and (b) the segregation and disunity that affected their identity construction through social relations. Although subtractive schooling apparently facilitated students’ integration into the mainstream, its invisible power forced them not only to integrate but also to bear the full burden of constructing new identities to adjust to the school environment and the mainstream society.     

Review:Mycorrhizoremediation—an enhanced form of phytoremediation

INTRODUCTION Biosphere pollution by heavy metals and nu-cleotides was accelerated dramatically during the last few decades due to mining, smelting, manufacturing, treatment of agricultural soils with agro-chemicals and soil sludge, etc. Problems associated with the contamination of soil and water such as animal wel-fare, health, fatalities and disruptions of natural eco-systems are well documented (He et al., 2005). Heavy metals such as Pb, Cr, As, Cu, Cd, and Hg, being added to our so…     

Paulo Freire’s critical and dialogic pedagogy and its implications for the Bahraini educational context

Abstract

This paper is a conceptual analysis in methodology. The purpose it fulfils is that of analysing the critical and dialogic pedagogy of Paulo Freire, to arrive at implications of Freire’s philosophy and approach for the current educational context of the Kingdom of Bahrain. The Bahraini context is currently one of major economic, social, and educational reforms. Despite several reform initiatives, however, schools in Bahrain are still not advancing as they should be and deficiencies continue to exist in students’ development of higher-order thinking skills, such as critical thinking, problem-solving, and analysis. Among the implications made by this study are ones related to: teaching and learning practices within a classroom, cultivation of 21st Century skills, curriculum development and planning, and the role played by the teacher. The paper ends with a number of significant recommendations for teachers and policy-makers, which can enhance education in Bahrain and help it progress faster. These recommendations can also prove to be useful to other parallel contexts regionally and internationally.     

A comparative study of conventional and supercritical fluid extraction methods for the recovery of secondary metabolites from <Emphasis Type="Italic">Syzygium campanulatum</Emphasis> Korth

Syzygium campanulatum Korth is a plant, which is a rich source of secondary metabolites (especially flavanones, chalcone, and triterpenoids). In our present study, three conventional solvent extraction (CSE) techniques and supercritical fluid extraction (SFE) techniques were performed to achieve a maximum recovery of two flavanones, chalcone, and two triterpenoids from S. campanulatum leaves. Furthermore, a Box-Behnken design was constructed for the SFE technique using pressure, temperature, and particle size as independent variables, and yields of crude extract, individual and total secondary metabolites as the dependent variables. In the CSE procedure, twenty extracts were produced using ten different solvents and three techniques (maceration, soxhletion, and reflux). An enriched extract of five secondary metabolites was collected using n-hexane:methanol (1:1) soxhletion. Using food-grade ethanol as a modifier, the SFE methods produced a higher recovery (25.5%?84.9%) of selected secondary metabolites as compared to the CSE techniques (0.92%?66.00%).