Quantitative structure-activity relationship for antimalarial activity of artemisinin

The increase in resistance to older drugs and the emergence of new types of infection have created an urgent need for discovery and development of new compounds with antimalarial activity. Quantitative-Structure Activity Relationship (QSAR) methodology has been performed to develop models that correlate antimalarial activity of artemisinin analogs and their molecular structures. In this study, the data set consisted of 197 compounds with their activities expressed as log RA (relative activity). These compounds were randomly divided into training set (n=157) and test set (n=40). The initial stage of the study was the generation of a series of descriptors from three-dimensional representations of the compounds in the data set. Several types of descriptors which include topological, connectivity indices, geometrical, physical properties and charge descriptors have been generated. The number of descriptors was then reduced to a set of relevant descriptors by performing a systematic variable selection procedure which includes zero test, pairwise correlation analysis and genetic algorithm (GA). Several models were developed using different combinations of modelling techniques such as multiple linear regression (MLR) and partial least square (PLS) regression. Statistical significance of the final model was characterized by correlation coefficient, r2 and root-mean-square error calibration, RMSEC. The results obtained were comparable to those from previous study on the same data set with r2 values greater than 0.8. Both internal and external validations were carried out to verify that the models have good stability, robustness and predictive ability. The cross-validated regression coefficient (r2 cv) and prediction regression coefficient (r2 test) for the external test set were consistently greater than 0.7. The QSAR models developed in this study should facilitate the search for new compounds with antimalarial activity

Satu Kajian Kes Tentang Masalah Remaja Sekolah dan Kaitannya dengan Pencapaian Akademik

Kajian ini cuba meninjau masalah-masalah yang dihadapi oleh para remaja sekolah dan kaitannya dengan pencapaian akademik. Kajian ini juga cuba memastikan sama ada terdapat perbezaan masalah yang dihadapi berdasarkan jantina, bangsa dan status sosio-ekonomi. Kajian ini juga cuba mengenalpasti pola rujukan pembimbing kalangan remaja apabila mereka menghadapi masalah. Penyelidikan ini merupakan kajian kes terhadap 230 orang pelajar Tingkatan Empat Sekolah Menengah Taman Selayang (1), Batu Caves, Selangor. Data dikumpulkan melalui soal selidik latar belakang pelajar, soal selidik pola rujukan pembimbing dan Senarai Semak Masalah Mooney. Kaedah statistik yang digunakan dalam analisis data ialah analisis frekuansi, min dan peratusan, ujian-t, ujian ANOVA, Ujian Post Hoc Multiple Comparison LSD, dan ujian korelasi Pearson. Untuk semua ujian statistik, nilai alpha yang digunakan ialah .05. Hasil kajian mendapati bahawa masalah utama yang dihadapi oleh para pelajar remaja ialah masalah akademik dan kerjaya. Analisis ujian-t menunjukkan bahawa terdapat perbezaan signifikan masalah yang dihadapi berdasarkan jantina. Analisis ujian ANOVA menunjukkan bahawa, pada keseluruhannya terdapat perbezaan yang signifikan masalah yang dihadapi berdasarkan bangsa dan status sosio-ekonomi. Analisis ujian Post Hoc Multiple Comparison LSD menjelaskan bahawa perbezaan min yang signifikan lebih ketara antara pelajar Melayu dengan pelajar Cina, pelajar Melayu dengan pelajar India dan pelajar status sosio-ekonomi tinggi dengan pelajar status sosio-ekonomi rendah. Analisis ujian korelasi Pearson menjelaskan pada keseluruhannya terdapat hubungan yang sederhana antara masalah yang dihadapi dengan pencapaian akademik. Akhir sekali hasil kajian ini juga menjelaskan bahawa rakan merupakan pembimbing utama bagi pelajar remaja apabila mereka menghadapi masalah

Molecular Characterization of Vibrio Alginolyticus Isolated From Orbicularia Orbiculata and Corbiculla Moktiana

Bivalves are prone to bacterial contamination and can be health risk to the consumers. Antibiotic resistance, plasmid profiling and randomly amplified polymorphic DNA analysis (RAPD-PCR) were used to characterize and to detect the clonal relatedness of a total of 60 strains of Vibrio alginolyticus isolated from bivalve (Orbicularia orbiculata) obtained from Tanjung Karang, Selangor, Malaysia and bivalve (Corbiculla moktiana) from Lake Sangkarak, Padang, Indonesia. Antibiotic susceptibility testing to 13 antibiotics showed that all (60) strains were 100% susceptible to gentamicin. All V. alginolyticus isolated from O. orbiculata were 100% resistant to penicillin G. In contrast, there was variability of resistance for C. moktiana isolates towards antibiotic tested. The common resistant patterns for the isolates were resistant to three antibiotics but they did not share the same type of multiple antibiotic resistance. 46.7% and 76.7% of the plasmid occurrence rates were observed among V. alginolyticus isolated from bivalve O. orbiculata (Malaysia) and C. moktiana (Indonesia), respectively. The plasmid sizes ranged between 3.4 to 27.8 kbp with 18 plasmid patterns. A large number of strains (38.3%) were devoid of plasmid but were resistant to penicillin G, nalidixic acid and chloramphenicol. No correlation could be established between the presence of plasmids and antibiotic resistant because many resistant strains were without plasmid. For RAPD-PCR analysis, ten 10-mer primers were screened for both samples and only one primer – primer 3 (Gold - Oligo OPAR 3- 5’ GTGAGGCGCA 3’) showed reproducible and clear banding patterns. Gold-Oligo OPAR 3 produced 59 RAPD patterns. Dendrogram was constructed and analyzed. Four clusters with four untypeable strains were generated. There were similar clones isolated from O. Orbiculata (Malaysia) and C. moktiana (Indonesia) and also clones specific to either O. Orbiculata or C. moktiana. The high level of genomic diversity among these isolates irrespective of geographic origin was confirmed by this technique. It was suggested that strains of V. alginolyticus from both bivalve species were closely related to each other although they were isolated from different geographical areas. The aquatic environment including the bivalves is implicated as the reservoirs for V. alginolyticus and consequently they are responsible for transmission to human. The findings stressed the importance of this bacteria to food safety, public health an even economic

Nature versus built

Nature is made up of various living and non-living things which is related to plants, animals and other features such as mountains, deserts and seas. They are connected and some of the relationships between members are direct and obvious and ecosystem occurred to balance the amount of living things. Built environment is referring to aspects of creature human-made surroundings. Human activities caused some environmental issues and disturbance the nature. However, the technologies introduce sustainability building and creature as conservation our nature. There also some ways can be practice at house to save the environment

Effect of strength and stiffness distributions on the displacement demands of asymmetric reinforced concrete buildings / Suhailah Mohamed Noor

Torsional response characteristics of forty building models of elastic and inelastic asymmetric reinforced concrete buildings were studied by analyzing the near-fault and far-fault ground motions recorded during seven-pairs of recent earthquakes. The strength and stiffness eccentricities are the main parameters used in the present study contributing to the strength and stiffness distributions of building models under five mainmodels and eight submodels, respectively. The displacement demands of all buildings under the stiff and flexible sides were obtained from the analysis due to different values of fundamental period of vibrations as well as behavior factors by using RUAUMOKO-3D program before raw data of lateral displacement at each node were extracted using FORTRAN program. All data were then summarized in accordance to the strength and stiffness distributions in order to determine the impact of either strength distribution or stiffness distribution to the torsional behavior of one-story asymmetric reinforced concrete buildings. The torsional behavior of all building models were presented in terms of the normalized displacements at the stiff and flexible sides by the ratio of the maximum lateral displacement at the stiff and flexible sides to the maximum lateral displacement at the center of the building models

Characterization Of Biochar Derived From Tapioca Wastes

The main objective of this study is to investigate the impacts of various pyrolysis parameters such as terminal temperature, heating rate, holding time and ash content of feedstock on the biochar yield and its characteristics. Objektif utama kajian ini adalah untuk menyiasat kesan pelbagai parameter pirolisis seperti suhu terminal, kadar pemanasan, masa tetapan dan kandungan abu bahan suapan terhadap hasil bioarang dan ciri-ciriny

The influence of social network in moderating the relationship between training transfer determinants and goal setting of Malay women owners of small businesses / Norlina Mohamed Noor

The main objective of this research is to investigate the moderating effect of social network in terms of the interaction between trainees and primary stakeholders to establish its influence on training transfer determinants and Malay women owners of small businesses’ goal setting. The majority of the studies on training transfer have focused on the individual and situational factors in contributing towards training transfer but a very small number concentrated on the role of social network especially among Malay women owners of small businesses. The instrument used for this research is a modification of Training Transfer Model by Baldwin and Ford (1988) and Model of Excellence by McLagan and Bedrick (1983). Three factors: training content, training delivery and opportunity to use as training transfer determinants were taken from the Model of Training Transfer and trainer competency, which was taken from Model of Excellence, formed the conceptual framework for this research. Social network as moderating variable was added in this framework. Interaction of Social Network before, during, after and four months after training between trainees with organizer, trainer and colleagues were included as part of the items asked in the questionnaire. Women attending basic training programs organized by INSKEN (National Institute of Entrepreneurs), MARA (Council of Trust for Bumiputera) and JPW (Department of Women Development) were selected as the respondents for this research. Multiple and hierarchical regressions were used to analyze the data

Factors influencing attrition among learners : Faculty of Applied Social Sciences in OUM

This study examined factors affecting the attrition rate among learners in Open and Distance Learning (ODL) institution. The main focus of the study is to explore what factors cause the attrition, and what are the best ways or strategies to prevent the attrition rate among adult learners. There were 15 adult learners from the Faculty of Applied and Social Sciences (FASS) at Open University Malaysia (OUM) were taken from the population of dormant learners which were not registered for three concurrent semesters. The study found that the main factor of attrition was learners were overextended with too many responsibilities. The three ways to prevent attrition among learners were learners’ communication, learners’ mentoring, and learners’ awareness. It is recommended that the best practice for prevention learners’ attrition was learner itself. This study offered two benefits, factors affecting the attrition rate among adult learners and offered some ways in preventing attrition among adult learners from learners’ own perspective. Therefore, this study can be used as a benchmark for the faculty to handle the attrition cases for adult learners in open and distance learning institutions. (Abstract by author

Leadership style in knowledge-based culture: The competitive advantage approach

In nowadays economy, knowledge becoming the primary bases of core competency and key to superior performance. Several reasons are advanced for the implementation of knowledge management (KM) within companies. These includes of the widespread digitalisation of business environments; the rise of time-based competition that require firms to learn as much as possible in very short periods; the globalization of operations; and the high incidence of mergers and takeovers. Thus, for these reasons, it is crucial for a company to explore any factors that can enhance the knowledge-based organization. The proper way in managing the knowledge will lead to firm’s competitive advantage achievement. In this paper, the leadership styles as important factors in enhance the practices of knowledge-based culture will be the main focused. Specifically, this paper is to address three main objectives. First objective is to discuss the important of leadership styles in association to organizational learning culture, the most excellent principal in order to manage and value knowledge. Secondly, this paper will explain the important of leadership styles in firm’s competitive advantage achievement. And lastly, this paper will further discuss the important of leadership role in inter-firm settings and it relationship to competitive advantage