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Kuala Lumpur, Malaysia

The University of Malaya is a public research university located in Kuala Lumpur, Malaysia. It is the oldest and most esteemed university in Malaysia. The university's name was abbreviated as Malaya during the pre-independence period.The university was founded in 1949 as a public-funded tertiary institution. Today, it has more than 2,500 faculty members. In 2012, UM was granted autonomy status by the Ministry of Higher Education.In 2014, the QS World University Rankings has ranked UM at the 151st place of the world. Wikipedia.

Tamjidyamcholo A.,University of Malaya
Proceedings 2012 International Conference on Cyber Security, Cyber Warfare and Digital Forensic, CyberSec 2012 | Year: 2012

Nowadays, information systems comprise a crucial part of organizations; by losing security, these organizations will lose plenty of competitive advantages as well. The core point of information security (InfoSecu) is risk management. There are a great deal of research works and standards in security risk management (ISRM) including NIST 800-30 and ISO/IEC 27005. However, only few works of research focus on InfoSecu risk reduction, and while the standards explain general principles and guidelines, they do not provide any implementation details regarding ISRM. Reducing the InfoSecu risks in uncertain environments is painstaking. Thus, this paper applied a genetic algorithm (GA) for InfoSecu risk reduction in uncertainty. Finally, the effectiveness of the applied method was verified through an example. © 2012 IEEE.

Mohammed H.A.,University of Tenaga Nasional | Al-Aswadi A.A.,University of Tenaga Nasional | Shuaib N.H.,University of Tenaga Nasional | Saidur R.,University of Malaya
Renewable and Sustainable Energy Reviews | Year: 2011

Research in convective heat transfer on internal separated flows has been extensively conducted in the past decades. This review summarizes numerous researches on two topics. The first section focuses on studying the fluid flow and heat transfer behavior of different types of single-phase fluid flows over backward facing step (BFS) at different orientations. The second section concentrates on everything related to nanofluids; its preparation, properties, behavior, applications, and many others. The purpose of this article is to get a clear view and detailed summary of the influence of several parameters such as the geometrical specifications, boundary conditions, type of fluids, and inclination angle on the hydrodynamic and thermal characteristics using (BFS). The reattachment length and maximum Nusselt number are the main target of such research where correlation equations were developed and reported in experimental and numerical studies. The heat transfer enhancement of nanofluids along with the nanofluids preparation technique, types and shapes of nanoparticles, base fluids and additives, transport mechanisms, and stability of the suspension are also discussed. © 2011 Elsevier Ltd. All rights reserved.

Caracelli I.,Federal University of Sao Carlos | Zukerman-Schpector J.,Federal University of Sao Carlos | Tiekink E.R.T.,University of Malaya
Coordination Chemistry Reviews | Year: 2012

Consistent with macromolecular structures, Se(lone pair)...π(aryl) interactions are found in the crystal structures of molecular compounds. Supramolecular aggregation patterns based solely on these types of interactions were usually zero- or one-dimensional with a smaller number of examples of two- and three-dimensional architectures. The analysis proves that Se(lone pair)...π(aryl) interactions function as supramolecular synthons in the structural chemistry of selenium compounds. © 2011 Elsevier B.V.

Samuel V.B.,University of Malaya | Agamuthu P.,University of Kuala Lumpur | Hashim M.A.,University of Kuala Lumpur
Ecological Indicators | Year: 2013

The primary objective of this study was to provide an insight into sustainable production indicators used by the petrochemical industry in Malaysia to measure the sustainability of the industry's operations. In achieving the research objective, the case study method was employed. The petrochemical industry was selected because of its major contribution to the Malaysian economy (market share and total investment), its significant impacts to the environment and, high societal and occupational risks. The sector is also highly dependent on non-renewable fossil fuels such as natural gas, LPG and diesel; and is energy intensive. Utilising the five-tier framework developed by the Lowell Centre for Sustainable Production (LCSP) and indicators identified by the Global Reporting Initiative (GRI) Guidelines 3.1, an analysis of indicators used by the petrochemical sector was carried out. The LCSP framework was selected as it is an established framework and has been successfully used in similar case studies in other parts of the world. Furthermore, at present there is no common framework in Malaysia to assess sustainable production at the industrial level. Under the GRI guidelines, performance indicators have been grouped into six categories. The six categories include Environment (EN1-EN30), Economic (EC1-EC9), Society (SO1-SO8), Human Rights (HR1-HR9), Labour Practices and Decent Work (LA1-LA14) and Product Responsibility (PR1-PR9). The study was carried out using the questionnaire survey method and supplemented with semi-structured in-depth interviews. To ensure their suitability and applicability in the Malaysian context, the indicators selected for the study were based on feedback obtained from the participating companies. An analysis of the information obtained from the participating companies indicates the satisfactory performance of the petrochemical industry in employing most of the indicators identified within the GRI framework to advance towards sustainability. Results indicate that the majority of the indicators monitored are related to compliance (Level 1), performance (Level 2) and environmental impacts (Level 3). The single Level 4 indicator which relates to products and services was weakly monitored (38.5%). None of the indicators monitored fell within Level 5 category which addresses sustainability issues in terms of the ecological carrying capacity. The Level 5 indicators which assess sustainability in a community or regional context can only be effectively implemented once the necessary policies and regulations are in place; and with greater awareness and cooperation between the regulators and stakeholders. © 2012 Elsevier Ltd. All rights reserved.

Ismail Z.,University of Malaya | Karim R.,Petmel Resources Private Ltd
Safety Science | Year: 2013

The petroleum industry is most concerned about safety and one which has an effective safety culture. This study analyzed the accident cycle in the sea transportation activities of the industry. The analysis was based on published data over the past 44. years involving spills of 1000 tonnes and above. Total spill volume was 4.27 mil tonnes with a mean of 64,000 tonnes and a standard deviation of 86,6000 tonnes. Total cleanup cost was estimated to be 17.8546 bil Int$, with a mean of 955.075 mil Int$, a standard deviation of 698.376 mil Int$. It was observed over the study period there seemed to be a cycle of about 10. years. There was a decreasing trend of spill volume. Crude represented 99% and the rest involved final products. About 65% of the tankers finally broke up and about 35% was associated with fire and explosion. Navigation error caused 42.5% of the accidents, storms and hurricanes caused 31.8% of the accidents, mechanical and maintenance related factors caused 18.2% of the accidents, engine failure represented 4.5% and other causes with about 3%. The highest number of deaths was recorded from the Independenta with 43. © 2012 Elsevier Ltd.

A bibliographic review of the crystallographic literature has been conducted on gold(I) compounds bearing functional groups capable of forming conventional hydrogen bonding interactions, namely, primary amide, secondary amide and carboxylic acid. The clear majority of structures featured hydrogen bonding interactions leading to well defined zero- or one-dimensional supramolecular architectures; rarely were two-dimensional architectures formed. Conversely, aurophilic, Au⋯Au, were the exception rather than the rule. This observation is correlated with steric hindrance: small atoms associated via directional hydrogen bonding compared with encumbered gold-atom environments (due to bulky ligands). Amide-{⋯HNCO}2 and carboxylic acid-{⋯HOCO}2 synthons featured in significantly more of the gold(I) structures compared with all-organic systems, particularly for non-ionic structures where charged-assisted hydrogen bonding precluded the formation of these cyclic synthons. This suggests a crystal engineering strategy of functionalising metal complexes with hydrogen bonding potential to improve opportunities of rational design of crystal structures. © 2014.

Hakimi M.H.,Taiz University | Abdullah W.H.,University of Malaya
Marine and Petroleum Geology | Year: 2014

The Upper Cretaceous Mukalla coals and other organic-rich sediments which are widely exposed in the Jiza-Qamar Basin and believed to be a major source rocks, were analysed using organic geochemistry and petrology. The total organic carbon (TOC) contents of the Mukalla source rocks range from 0.72 to 79.90% with an average TOC value of 21.50%. The coals and coaly shale sediments are relatively higher in organic richness, consistent with source rocks generative potential. The samples analysed have vitrinite reflectance in the range of 0.84-1.10 %Ro and pyrolysis Tmax in the range of 432-454°C indicate that the Mukalla source rocks contain mature to late mature organic matter. Good oil-generating potential is anticipated from the coals and coaly shale sediments with high hydrogen indices (250-449mg HC/g TOC). This is supported by their significant amounts of oil-liptinite macerals are present in these coals and coaly shale sediments and Py-GC (S2) pyrograms with n-alkane/alkene doublets extending beyond nC30. The shales are dominated by Type III kerogen (HI<200mg HC/g TOC), and are thus considered to be gas-prone.One-dimensional basin modelling was performed to analysis the hydrocarbon generation and expulsion history of the Mukalla source rocks in the Jiza-Qamar Basin based on the reconstruction of the burial/thermal maturity histories in order to improve our understanding of the of hydrocarbon generation potential of the Mukalla source rocks. Calibration of the model with measured vitrinite reflectance (Ro) and borehole temperature data indicates that the present-day heat flow in the Jiza-Qamar Basin varies from 45.0mW/m2 to 70.0mW/m2 and the paleo-heat flow increased from 80Ma to 25Ma, reached a peak heat-flow values of approximately 70.0mW/m2 at 25Ma and then decreased exponentially from 25Ma to present-day. The peak paleo-heat flow is explained by the Gulf of Aden and Red Sea Tertiary rifting during Oligocene-Middle Miocene, which has a considerable influence on the thermal maturity of the Mukalla source rocks. The source rocks of the Mukalla Formation are presently in a stage of oil and condensate generation with maturity from 0.50% to 1.10% Ro. Oil generation (0.5% Ro) in the Mukalla source rocks began from about 61Ma to 54Ma and the peak hydrocarbon generation (1.0% Ro) occurred approximately from 25 Ma to 20Ma. The modelled hydrocarbon expulsion evolution suggested that the timing of hydrocarbon expulsion from the Mukalla source rocks began from 15Ma to present-day. © 2013 Elsevier Ltd.

Khan M.N.,University of Malaya
Advances in Colloid and Interface Science | Year: 2010

A new method, based upon semi-empirical kinetic approach, for the determination of ion exchange constant for ion exchange processes occurring between counterions at the cationic micellar surface is described in this review article. Basically, the method involves a reaction kinetic probe which gives observed pseudo-first-order rate constants (kobs) for a nucleophilic substitution reaction between the nonionic and anionic reactants (R and S) in the presence of a constant concentration of both reactants as well as cationic micelles and varying concentrations of an inert inorganic or organic salt (MX). The observed data (kobs, versus [MX]) fit satisfactorily (in terms of residual errors) to an empirical equation which could be derived from an equation explaining the mechanism of the reaction of the kinetic probe in terms of pseudophase micellar (PM) model coupled with another empirical equation. This (another) empirical equation explains the effect of [MX] on cationic micellar binding constant (KS) of the anionic reactant (say S) and gives an empirical constant, KX/S. The magnitude of KX/S is the measure of the ability of X- to expel S- from a cationic micellar pseudophase to the bulk aqueous phase through ion exchange X -/S-. The values of KX/S and KY/S (where Y- is another inert counterion) give the ion exchange constant, KX Y (= KX/KY where K X and KY represent cationic micellar binding constants of X- and Y-, respectively). The suitability of this method is demonstrated by the use of three different reaction kinetic probes and various MX. © 2010 Elsevier B.V. All rights reserved.

Fathilah A.R.,University of Malaya
Journal of Medicinal Plants Research | Year: 2011

The objective of the study was to seek for new agents from plant extracts for use in dental plaque control. The emphasis was directed at the initial stage of dental plaque formation, specifically the adherence of bacteria referred to as the early plaque colonisers, to the acquired pellicle on the supragingival tooth surface. Streptococcus sanguinis, Streptococcus mitis and Actinomyces sp., the predominant bacteria involved at this initial stage of plaque development were used as test organisms. The aqueous extracts of Piper betle and Psidium guajava exhibited antimicrobial activities with MIC values in the range of 2.61 to 4.69 mg/mL and toxicity values (LC 50 and EC 50) well above their toxic concentrations. P. betle and P. guajava extracts contained 9.25 and 11.5 ppm fluoride, respectively. Some aggregating activity was also displayed by the extract of the latter. Both extracts showed positive antiadherence activity and reduced the cell-surface hydrophobicity of the bacteria which might have rendered them less adherent and hence, minimising their adhesion to the tooth surface during the early stage of plaque development. Both extracts also suppressed the growth of these bacteria. Such an activity was reaffirmed and supported by SEM micrographs whereby the bacterial cells were unable to divide or grow successfully and hence suggesting bacteriostatic effect of the extracts. Extracts of P. betle and P. guajava may work by first preventing and reducing the adhesion of primary bacterial colonisers to the tooth surface and second, to prevent or inhibit the growth and proliferation of microorganisms adhering on to the tooth surface and may potentiate their antiplaque activities. © 2011 Academic Journals.

Mishima T.,Kobe University | Takami C.,Kobe University | Nakaoka M.,Kyungnam University | Nakaoka M.,University of Malaya | Nakaoka M.,Yamaguchi University
IEEE Transactions on Industrial Electronics | Year: 2014

A novel soft-switching high-frequency (HF) resonant (HF-R) inverter for induction heating (IH) applications is presented in this paper. By adopting the current phasor control of changing a phase shift (PS) angle between two half-bridge inverter units, the IH load resonant current can be regulated continuously under the condition of wide-range soft-switching operations. In addition to this, the dual-mode power regulation scheme-based PS angle control and asymmetrical pulsewidth modulation in one inverter unit is proposed for improving the efficiency in low output power settings. The essential performances on the output power regulation and soft-switching operations are demonstrated in an experiment using its 1-kW 60-kHz HF-R inverter prototype, and then, the topological validity is evaluated from a practical point of view. © 2013 IEEE.

Polgar G.,University of Malaya | Bartolino V.,Institute of Marine Research
Marine Ecology Progress Series | Year: 2010

Reduction in size from sea to land is a common trend of many fish species and communities, at both the intraspecific and interspecific level. Within the intertidal zone, similar trends have been described at the intraspecific level in several transient and resident fish species. Oxudercines are a group of intertidal gobies (Gobiidae: Oxudercinae) including several species, which exhibit extreme adaptations to an amphibious lifestyle. Ecomorphological and ecophysiological considerations suggest that size reduction in this group may have facilitated the adaptation to semi-terrestrial conditions. To test this hypothesis, the spatial ecology and the presence of an intra- and interspecific size gradient was investigated in an oxudercine community of a Malayan intertidal ecosystem (6 species included in 3 genera). A random stratified sampling design was adopted, and ANOVA and cluster analysis performed to describe this variation. Multivariate analyses of the quantity of environmental water were also conducted to investigate the correspondence between size and habitat terrestriality. Larger species were found in more aquatic conditions at lower topographical levels along the vertical intertidal gradient, supporting the hypothesis of an adaptive value of smaller size in more terrestrial habitats. Intraspecific variation showed more complex patterns, even if in several species smaller individuals were found in more terrestrial conditions. © Inter-Research 2010.

Shahbaz M.,COMSATS Institute of Information Technology | Tang C.F.,University of Malaya | Shahbaz Shabbir M.,University of Illinois at Urbana - Champaign
Energy Policy | Year: 2011

The aim of this paper is to re-examine the relationship between electricity consumption, economic growth, and employment in Portugal using the cointegration and Granger causality frameworks. This study covers the sample period from 1971 to 2009. We examine the presence of a long-run equilibrium relationship using the bounds testing approach to cointegration within the Unrestricted Error-Correction Model (UECM). Moreover, we examine the direction of causality between electricity consumption, economic growth, and employment in Portugal using the Granger causality test within the Vector Error-Correction Model (VECM). As a summary of the empirical findings, we find that electricity consumption, economic growth, and employment in Portugal are cointegrated and there is bi-directional Granger causality between the three variables in the long-run. With the exception of the Granger causality between electricity consumption and economic growth, the rest of the variables are also bi-directional Granger causality in the short-run. Furthermore, we find that there is unidirectional Granger causality running from economic growth to electricity consumption, but no evidence of reversal causality. © 2011 Elsevier Ltd.

Beyrer C.,Center for Public Health and Human Rights | Malinowska-Sempruch K.,Open Society Institute | Kamarulzaman A.,University of Malaya | Kazatchkine M.,The Global Fund | And 2 more authors.
The Lancet | Year: 2010

The published work on HIV in people who use drugs shows that the global burden of HIV infection in this group can be reduced. Concerted action by governments, multilateral organisations, health systems, and individuals could lead to enormous benefits for families, communities, and societies. We review the evidence and identify synergies between biomedical science, public health, and human rights. Cost-effective interventions, including needle and syringe exchange programmes, opioid substitution therapy, and expanded access to HIV treatment and care, are supported on public health and human rights grounds; however, only around 10 of people who use drugs worldwide are being reached, and far too many are imprisoned for minor offences or detained without trial. To change this situation will take commitment, advocacy, and political courage to advance the action agenda. Failure to do so will exacerbate the spread of HIV infection, undermine treatment programmes, and continue to expand prison populations with patients in need of care. © 2010 Elsevier Ltd.

Jones E.B.G.,University of Malaya
Botanica Marina | Year: 2011

The diversity of marine fungi is reviewed based on new data on their occurrence on various substrata, unexplored habitats especially in the tropics, undescribed species, endophytic and cryptic taxa. Various estimates have been proposed for the number of marine fungi and this depends on whether the taxa are obligate, facultative or marine derived by isolation from various substrata or from seawater by culture methods. The current number of obligate marine fungi (537 species) is a gross underestimate. So where can further species be found? In this review, several fungal groups are identified that have been poorly surveyed for marine representatives and therefore a potential source of more marine species; these are marine derived fungi isolated from soils, sand, and water, planktonic fungi, deep-sea fungi, unculturable fungi, and cryptic species or taxa with similar morphology. In accounting for these potential sources the number of marine fungi might be in excess of 10,000 taxa. © 2011 by Walter de Gruyter Berlin Boston.

Liam C.-K.,University of Malaya | Wahid M.I.A.,Beacon International Specialist Center | Rajadurai P.,Monash University | Cheah Y.-K.,University Putra Malaysia | Ng T.S.-Y.,University Putra Malaysia
Journal of Thoracic Oncology | Year: 2013

Introduction: Despite available data from other Asian countries, the prevalence of epidermal growth factor receptor (EGFR) mutations among lung adenocarcinoma patients has not been reported in Malaysia. This study sought to determine the frequency of EGFR mutations among multiethnic Malaysian patients diagnosed with lung adenocarcinoma. Methods: Demographic and clinical information of patients whose lung adenocarcinoma biopsy specimens were submitted for EGFR mutation testing at Sime Darby Medical Center from 2009 to 2011 were analyzed. EGFR mutations at exons 18, 19, 20, and 21 were detected either through bidirectional sequencing or real-time polymerase chain reaction. Results: Among 812 patients in the study, 49% were female, 63.7% were ethnic Chinese, 29.4% Malay, 4.8% Indian, and 2.1% other ethnic groups. Mutations were present in the tumors of 321 patients (39.5%), with mutations at exons 19 (23.5%) and 21 (14.9%) being the most common. Mutations were significantly more frequent among women than in men (52.5% versus 27.8%, p < 0.001). Although mutations were more common among Chinese (40.8%) compared with Malay (37.2%) or Indian (33.3%) patients, the difference was not statistically significant (p = 0.591). Of 211 patients with smoking history records, never-smokers had a higher mutation rate compared with ever-smokers (54.8% versus 20.7%, p < 0.001). Conclusion: EGFR mutations were present in 39.5% of patients. Mutations were more common in women and never-smokers with no differences in mutation frequency between different ethnicities. Because of the high mutation rates, reflex testing for EGFR mutation should be a routine practice for advanced lung adenocarcinoma patients in Malaysia. Copyright ©2013 by the International Association for the Study of Lung Cancer.

Sun Z.,Curtin University Australia | Ng K.H.,University of Malaya
Singapore Medical Journal | Year: 2010

Multislice computed tomography (CT) angiography represents a technological evolution in cardiac imaging due to improved spatial and temporal resolution. Rapid improvements in multislice CT scanners over the last decade have allowed this technique to become a viable and effective alternative to invasive coronary angiography in selected patients. Multislice CT angiography has demonstrated high sensitivity and specificity, and in particular, a very high negative predictive value, which makes it a valuable imaging modality for screening patients suspected of coronary artery disease. In addition, multislice CT angiography demonstrates accuracy in the detection and characterisation of coronary plaques, and it has been reported to play an important role in predicting disease progression and cardiac events. The aim of this review was to present an overview of the clinical applications of multislice CT angiography in coronary artery disease, with regard to its diagnostic accuracy and predictive value in coronary artery disease. Emerging areas of multislice CT, including dual-energy CT and CT myocardial perfusion, are also discussed. Limitations of multislice CT angiography and future directions of cardiac multislice CT are highlighted.

Shahid S.,University of Malaya
Theoretical and Applied Climatology | Year: 2011

A study of the variability of the extreme rainfall events in Bangladesh during the time period 1958-2007 has been carried out in this paper. Quality-controlled homogeneous daily precipitation records of nine stations distributed over Bangladesh are used for the study. A total of 15 annual and seasonal indices of rainfall are examined. Variability of annual and seasonal rainfall trends is also assessed. The Mann-Kendall statistic and Sen's Slope model are used to reveal the trends and estimate the magnitude of change, respectively. A significant increase of annual and pre-monsoon rainfall in Bangladesh is observed. In general, an increasing trend in heavy precipitation days and decreasing trends in consecutive dry days are observed. Significant change in most of the extreme rainfall indices are observed in Northwest Bangladesh. © 2010 Springer-Verlag.

Tang C.F.,University of Malaya | Shahbaz M.,COMSATS Institute of Information Technology | Arouri M.,EDHEC Business School
Energy Policy | Year: 2013

In the previous decades, a number of studies have been conducted to analyse the causal relationship between electricity consumption and economic growth in the Portuguese economy. However, the evidence remains controversial because the previous studies do not provide clear causality evidence. This might be attributed to the omitted variables bias because most previous studies only focus on the relationship between electricity consumption and economic growth in a bi-variate model. This paper attempts to re-investigate the relationship between electricity consumption and economic growth in Portugal using a multivariate model. Based on the bounds testing approach to cointegration and the Granger causality test within the vector error-correction model (VECM), our empirical results confirm the presence of cointegration among the variables. Moreover, there is evidence of bi-directional causality between electricity consumption and economic growth in the short- and long-run. This suggests that energy is an important source of economic growth in Portugal. Therefore, energy conservation policies should not be implemented because it would deteriorate the process of economic growth and development of the Portuguese economy. © 2013 Elsevier Ltd.

Alahmadi S.M.,University of Malaya
Asian Journal of Chemistry | Year: 2011

Organotin compounds have been used on a global scale for many decades now and thus have become global environmental contaminants. These compounds are highly toxic and deleterious effects on numerous organisms have been demonstrated. Several analytical methods for the determination of organotin compound in environmental (e.g., water, sediment and shellfish) have been developed. Analysis of organotin species in the environment needs highly selective and sensitive methods. This paper reviews the organotin speciation analysis based on liquid or gas chromatography.

Al-Matary A.,King Fahad Medical City Riyadh | Ali J.,University of Malaya
BMC Medical Ethics | Year: 2014

Background: Approximately one-fourth of all the inhabitants on earth are Muslims. Due to unprecedented migration, physicians are often confronted with cultures other than their own that adhere to different pdigms. Discussion. In Islam, and most religions, abortion is forbidden. Islam is considerably liberal concerning abortion, which is dependent on (i) the threat of harm to mothers, (ii) the status of the pregnancy before or after ensoulment (on the 120§ssup§th§esup§ day of gestation), and (iii) the presence of foetal anomalies that are incompatible with life. Considerable variation in religious edicts exists, but most Islamic scholars agree that the termination of a pregnancy for foetal anomalies is allowed before ensoulment, after which abortion becomes totally forbidden, even in the presence of foetal abnormalities; the exception being a risk to the mother's life or confirmed intrauterine death. Summary. The authors urge Muslim law makers to also consider abortion post ensoulment if it is certain that the malformed foetus will decease soon after birth or will be severely malformed and physically and mentally incapacitated after birth to avoid substantial hardship that may continue for years for mothers and family members. The authors recommend that an institutional committee governed and monitored by a national committee make decisions pertaining to abortion to ensure that ethics are preserved and mistakes are prevented. Anomalous foetuses must be detected at the earliest possible time to enable an appropriate medical intervention prior to the 120th day. © 2014 Al-Matary and Ali; licensee BioMed Central Ltd.

Yazdi H.A.M.,Islamic Azad University at Maybod | Sulong N.H.R.,University of Malaya
Journal of Constructional Steel Research | Year: 2011

In this paper, a method based on genetic algorithm is proposed for determining the optimum connection point with the highest lateral buckling load in the Off-Centre bracing system. This type of bracing system is mostly used in seismic areas and it allows architects to have more openings in the panel area. In this system, the non-straight diagonal member introduces eccentricity to the system and is connected to the corner of the frame by a third member. In designing this system, designers often use "trial and error" to locate the connection point of the brace elements considering various parameters affecting the design such as opening and frame dimensions, cross sectional areas of brace elements and the location of the brace element connection. Hence, finding the best connection point with maximum lateral buckling load can be problematic by the conventional methods. To demonstrate the effectiveness of the proposed GA method, examples with different frame specifications were presented. © 2011 Elsevier Ltd. All rights reserved.

Tang O.,Linkoping University | Tang O.,Tongji University | Nurmaya Musa S.,Linkoping University | Nurmaya Musa S.,University of Malaya
International Journal of Production Economics | Year: 2011

The purpose of this paper is to investigate the research development in supply chain risk management (SCRM), which has shown an increasing global attention in recent years. Literature survey and citation/co-citation analysis are used to fulfil the research task. Literature survey has undertaken a thorough search of articles on selected journals relevant to supply chain operations management. Meanwhile, citation/co-citation analysis uses Web of Sciences database to disclose SCRM development between 1995 and 2009. Both the approaches show similar trends of rising publications over the past 15 years. This review has piloted us to identify and classify the potential risk associated with different flows, namely material, cash and information flows. Consequently, we identify some research gaps. Even though there is a pressing need and awareness of SCRM from industrial aspect, quantitative models in the field are relatively lacking and information flow risk has received less attention. It is also interesting to observe the evolutions and advancements of SCRM discipline. One finding is that the intellectual structure of the field made statistically significant increase during 20002005 and evolved from passively reacting to vague general issues of disruptions towards more proactively managing supply chain risk from system perspectives. © 2010 Elsevier B.V. All rights reserved.

Lee W.S.,University of Malaya
Journal of Health and Translational Medicine | Year: 2010

The liver is an important organ of the human body, playing a major role in the metabolism and storage of nutrients, synthesis of protein and other nutrients, as well as detoxifying many metabolic by-products. The response of the foetal and newborn liver to external insult and injury is limited. This is because the ability of the closely interdependent structures of a developing liver of expressing in the face of a variety of insults is limited as well. Thus most infants with insults to the liver present as cholestatic jaundice with variable degree of pale stools, enlarged liver and conjugated hyperbilirubinaemia. Biliary atresia, an idiopathic condition characterized by progressive fibrosing obliteration of both intra- and extrahepatic bile ducts, is the most important cause of neonatal cholestasis worldwide, including Malaysia. It is also the most important indication for childhood liver transplantation the world over. Challenges facing infants with biliary atresia include a delay in the diagnosis and late surgery, leading to a poor outcome. This often results from a failure to recognise the potential serious nature of an infant with prolonged cholestatic jaundice and pale stools among health care professionals.

Yap B.W.,University Technology of MARA | Ong S.H.,University of Malaya | Husain N.H.M.,University Technology of MARA
Expert Systems with Applications | Year: 2011

Credit scoring model have been developed by banks and researchers to improve the process of assessing credit worthiness during the credit evaluation process. The objective of credit scoring models is to assign credit risk to either a "good risk" group that is likely to repay financial obligation or a "bad risk" group who has high possibility of defaulting on the financial obligation. Construction of credit scoring models requires data mining techniques. Using historical data on payments, demographic characteristics and statistical techniques, credit scoring models can help identify the important demographic characteristics related to credit risk and provide a score for each customer. This paper illustrates using data mining to improve assessment of credit worthiness using credit scoring models. Due to privacy concerns and unavailability of real financial data from banks this study applies the credit scoring techniques using data of payment history of members from a recreational club. The club has been facing a problem of rising number in defaulters in their monthly club subscription payments. The management would like to have a model which they can deploy to identify potential defaulters. The classification performance of credit scorecard model, logistic regression model and decision tree model were compared. The classification error rates for credit scorecard model, logistic regression and decision tree were 27.9%, 28.8% and 28.1%, respectively. Although no model outperforms the other, scorecards are relatively much easier to deploy in practical applications. © 2010 Elsevier Ltd. All rights reserved.

Ngeow W.C.,University of Malaya | Nair R.,American International Assurance Company
Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontology | Year: 2010

This article illustrates a case of persistent trigeminal neuralgia in a medically compromised 65-year-old female who did not respond to pharmacotherapy. She had undergone several peripheral neurectomies as well as a failed right posterior fossa exploration that resulted in a cerebrospinal fluid leak. Persistent pain over the right external nasal area and right mental region was relieved for several hours after daily injections of bupivacaine. A trial of a single dose of 100 units of botulinum toxin type A (BOTOX) diluted in 2.5 mL saline was injected into the external nasal trigger zone (60 units) and to the mental nerve region (40 units). She achieved complete pain relief in the external nasal region for 5 months. Pain recurred and the site was again injected with 100 units of botulinum toxin type A (BOTOX). Pain relief at the mental region was partial. This was finally controlled with peripheral neurectomy. The patient was pain free with a maintenance dose of 200 mg carbamazepine daily for about 1 year, after which she elected to undergo stereotactic gamma knife radiosurgery when pain recurred at the external nasal region. © 2010 Mosby, Inc. All rights reserved.

Loh S.Y.,University of Malaya
Journal of Health and Translational Medicine | Year: 2010

As women with breast cancer are living longer, issues beyond survivorship like the much neglected sexual functioning and issue of quality of life have become increasingly important. Experiences of significant alterations in sexual functioning need to be addressed. However, these sexual issues are often not acknowledged in our traditional medical model of health care delivery. This paper briefly reviews the changes in sexual functioning after a diagnosis of breast cancer, with implication for clinical practice and medical curicula.

Shabaruddin F.H.,University of Malaya | Chen L.-C.,University of Nottingham | Elliott R.A.,University of Nottingham | Payne K.,University of Manchester
PharmacoEconomics | Year: 2013

Background: Chemotherapy offers cancer patients the potential benefits of improved mortality and morbidity but may cause detrimental outcomes due to adverse drug events (ADEs), some of which requiring time-consuming, resource-intensive and costly clinical management. To appropriately assess chemotherapy agents in an economic evaluation, ADE-related parameters such as the incidence, (dis)utility and cost of ADEs should be reflected within the model parameters. To date, there has been no systematic summary of the existing literature that quantifies the utilities of ADEs due to healthcare interventions in general and chemotherapy treatments in particular. Objective: This review aimed to summarize the current evidence base of reported utility values for chemotherapy-related ADEs. Methods: A structured electronic search combining terms for utility, utility valuation methods and generic terms for cancer treatment was conducted in MEDLINE and EMBASE in June 2011. Inclusion criteria were: (1) elicitation of utility values for chemotherapy-related ADEs and (2) primary data. Two reviewers identified studies and extracted data independently. Any disagreements were resolved by a third reviewer. Results: Eighteen studies met the inclusion criteria from the 853 abstracts initially identified, collectively reporting 218 utility values for chemotherapy-related ADEs. All 18 studies used short descriptions (vignettes) to obtain the utility values, with nine studies presenting the vignettes used in the valuation exercises. Of the 218 utility values, 178 were elicited using standard gamble (SG) or time trade-off (TTO) approaches, while 40 were elicited using visual analogue scales (VAS). There were 169 utility values of specific chemotherapy-related ADEs (with the top ten being anaemia [34 values], nausea and/or vomiting [32 values], neuropathy [21 values], neutropenia [12 values], diarrhoea [12 values], stomatitis [10 values], fatigue [8 values], alopecia [7 values], hand-foot syndrome [5 values] and skin reaction [5 values]) and 49 of non-specific chemotherapy-related adverse events. In most cases, it was difficult to directly compare the utility values as various definitions and study-specific vignettes were used for the ADEs of interest. Limitations: This review was designed to provide an overall description of existing literature reporting utility values for chemotherapy-related ADEs. The findings were not exhaustive and were limited to publications that could be identified using the search strategy employed and those reported in the English language. Conclusions: This review identified wide ranges in the utility values reported for broad categories of specific chemotherapy-related ADEs. There were difficulties in comparing the values directly as various study-specific definitions were used for these ADEs and most studies did not make the vignettes used in the valuation exercises available. It is recommended that a basic minimum requirement be developed for the transparent reporting of study designs eliciting utility values, incorporating key criteria such as reporting how the vignettes were developed and presenting the vignettes used in the valuation tasks as well as valuing and reporting the utility values of the ADE-free base states. It is also recommended, in the future, for studies valuing the utilities of chemotherapy-related ADEs to define the ADEs according to the National Cancer Institute (NCI) definitions for chemotherapy-related ADEs as the use of the same definition across studies would ease the comparison and selection of utility values and make the overall inclusion of adverse events within economic models of chemotherapy agents much more straightforward. © 2013 Springer International Publishing Switzerland.

Chung P.Y.,Monash University | Navaratnam P.,Monash University | Chung L.Y.,University of Malaya
Annals of Clinical Microbiology and Antimicrobials | Year: 2011

Background: There has been considerable effort to discover plant-derived antibacterials against methicillin-resistant strains of Staphylococcus aureus (MRSA) which have developed resistance to most existing antibiotics, including the last line of defence, vancomycin. Pentacyclic triterpenoid, a biologically diverse plant-derived natural product, has been reported to show anti-staphylococcal activities. The objective of this study is to evaluate the interaction between three pentacyclic triterpenoid and standard antibiotics (methicillin and vancomycin) against reference strains of Staphylococcus aureus.Methods and Results: The activity of the standard antibiotics and compounds on reference methicillin-sensitive and resistant strains of S. aureus were determined using the macrodilution broth method. The minimum inhibitory concentration (MIC) of the compounds was compared with that of the standard antibiotics. The interaction between any two antimicrobial agents was estimated by calculating the fractional inhibitory concentration (FIC index) of the combination. The various combinations of antibiotics and compounds reduced the MIC to a range of 0.05 to 50%.Conclusion: Pentacyclic triterpenoids have shown anti-staphylococcal activities and although individually weaker than common antibiotics produced from bacteria and fungi, synergistically these compounds may use different mechanism of action or pathways to exert their antimicrobial effects, as implicated in the lowered MICs. Therefore, the use of current antibiotics could be maintained in their combination with plant-derived antibacterial agents as a therapeutic option in the treatment of S. aureus infections. © 2011 Chung et al; licensee BioMed Central Ltd.

Saidur R.,University of Malaya
Energy Education Science and Technology Part A: Energy Science and Research | Year: 2010

Chillers consume a major share of total air conditioning energy use in commercial and industrial buildings for space conditioning to get thermal comfort for a country. In this paper, energy consumption by chillers has been estimated using data collected by walkthrough energy audit for Malaysian office buildings. It has been found that chillers use about 42,285MWh and 84,569MWh of electric energy for 50% and 100% loadings in an institutional buildings. As chillers are major energy users, energy savings measure such as use of energy efficient chillers and VSDs in chillers cooling load reductions have been applied to reduce their energy consumptions. It has been found that 90MWh-896MWh of energy can be saved for using energy efficient chillers for different percentage of loadings. Along with energy savings, US$57,314 as a bill savings can be achieved for high efficient chillers for 50% chillers loading. Study found that 35,975 MWh energy and US$2,302,431 bill can be saved for 60% of speed reductions using VSD. It was also found that payback periods for this energy saving option for chillers are economically viable. Along with energy savings, emission reductions and cost of avoided carbon associated with energy savings have been estimated and presented in this paper. © Sila Science.

Kumar S.,University of Malaya
Electronic Library | Year: 2016

Purpose ? This study aims to find the level of gender-based assortativity in the association of researchers and investigate if gender has influence over social capital of researchers and their research performance in the context of a multi-ethnic nation, such as Malaysia. Design/methodology/approach ? Social network analysis is used as a primary research method to analyse the associations between the authors. Mann-Whitney test is used for testing the significant differences in research performance and social capital based on gender. Findings ? The assortative mixing patterns of 187 researchers revealed positive assortativity, meaning that more authors preferred to co-author with authors of their gender. No influence of gender was seen on the social capital of authors. However, gender did significantly influence the research productivity of authors. Originality/value ? This is one of the first studies that attempts to find the influence of gender on collaborative associations of researchers in Malaysia. © 2016 Emerald Group Publishing Limited.

Zolkepli I.A.,Universiti Sains Malaysia | Kamarulzaman Y.,University of Malaya
Computers in Human Behavior | Year: 2015

This research is designed to empirically investigate how social media needs and innovation influence the adoption of social media amongst Internet users. The theoretical perspective of the uses and gratifications, and Rogers' five characteristics of innovation are reviewed and extended to explain the needs and motivations of the consumer. The study is conducted by testing and quantifying the relationship between the uses and gratifications of social media, while taking into consideration the mediating effect of social media technology innovation. This research applies a two-phase, multimethod strategy in the context of Malaysia. The strategy comprises the qualitative approach via focus group discussions (FGDs) with 48 respondents and the quantitative approach via online survey questionnaires with 428 respondents. Overall, the findings suggest that social media adoption is significantly driven by three types of need category - personal (consisting of enjoyment and entertainment), social (consisting of social influence and interaction) and tension release (consisting of belongingness, companionship, playfulness). In turn, these needs are motivated by the social media innovation characteristics (relative advantage, observability, compatibility) that increase the likelihood of the adoption. The research makes a significant contribution in the area of media and technology adoption, which can be used to help marketers understand the factors that motivate social media usage, particularly the UXDs in designing human-computer interaction strategies. © 2014 Elsevier Ltd. All rights reserved.

Balakrishnan V.,University of Malaya
Computers in Human Behavior | Year: 2015

This study investigated the extent of young adults' (N = 393; 17-30 years old) experience of cyberbullying, from the perspectives of cyberbullies and cyber-victims using an online questionnaire survey. The overall prevalence rate shows cyberbullying is still present after the schooling years. No significant gender differences were noted, however females outnumbered males as cyberbullies and cyber-victims. Overall no significant differences were noted for age, but younger participants were found to engage more in cyberbullying activities (i.e. victims and perpetrators) than the older participants. Significant differences were noted for Internet frequency with those spending 2-5 h online daily reported being more victimized and engage in cyberbullying than those who spend less than an hour daily. Internet frequency was also found to significantly predict cyber-victimization and cyberbullying, indicating that as the time spent on Internet increases, so does the chances to be bullied and to bully someone. Finally, a positive significant association was observed between cyber-victims and cyberbullies indicating that there is a tendency for cyber-victims to become cyberbullies, and vice versa. Overall it can be concluded that cyberbullying incidences are still taking place, even though they are not as rampant as observed among the younger users. © 2015 Elsevier Ltd.

Meyer J.P.,Yale University | Cepeda J.,Yale University | Wu J.,University of Connecticut | Trestman R.L.,University of Connecticut | And 3 more authors.
JAMA Internal Medicine | Year: 2014

IMPORTANCE Human immunodeficiency virus (HIV) management in correctional settings is logistically feasible, but HIV-related outcomes before release have not been recently systematically examined. OBJECTIVE To evaluate HIV treatment outcomes throughout incarceration, including jail and prison. DESIGN, SETTING, AND PARTICIPANTS Retrospective cohort study of longitudinally linked demographic, pharmacy, and laboratory data on 882 prisoners within the Connecticut Department of Correction (2005-2012) with confirmed HIV infection, who were continually incarcerated 90 days or more, had at least 2 HIV-1 RNA and CD4 lymphocyte measurements, and were prescribed antiretroviral therapy. MAIN OUTCOMES AND MEASURES Three electronic databases (correctional, laboratory, and pharmacy) were integrated to assess HIV viral suppression (HIV-1 RNA levels, <400 copies/mL) on intake and release. Secondary outcomes were mean change in log-transformed HIV-1 RNA levels and mean change in CD4 lymphocyte count during incarceration. Demographic characteristics, prescribed pharmacotherapies, receipt of directly observed therapy, and duration of incarceration were analyzed as possible explanatory variables for HIV viral suppression in logistic regression models. RESULTS Among 882 HIV-infected prisoners with 1185 incarceration periods, mean HIV-1 RNA level decreased by 1.1 log10 and CD4 lymphocyte count increased by 98 cells/μL over time, with a higher proportion achieving viral suppression by release compared with entry (70.0% vs 29.8%; P < .001); 36.9%of antiretroviral therapy (ART) regimens were changed during incarceration. After adjusting for baseline HIV-1 RNA level, prerelease viral suppression correlated with female sex (adjusted odds ratio, 1.81; 95%CI, 1.26-2.59) and psychiatric disorder severity below the sample median (adjusted odds ratio, 1.50; 95%CI, 1.12-1.99), but not race/ethnicity, incarceration duration, ART regimen or dosing strategy, or directly observed therapy. CONCLUSIONS AND RELEVANCE Though just one-third of HIV-infected prisoners receiving ART entered correctional facilities with viral suppression, HIV treatment was optimized during incarceration, resulting in the majority achieving viral suppression by release. Treatment for HIV within prison is facilitated by a highly structured environment and, when combined with simple well-tolerated ART regimens, can result in viral suppression during incarceration. In the absence of important and effective community-based resources, incarceration can be an opportunity of last resort to initiate continuous ART for individual health and, following the "treatment as prevention" paradigm, potentially reduce the likelihood of HIV transmission to others after release if continuity of HIV care is sustained. © 2014 American Medical Association. All rights reserved.

Mathiharan K.,University of Malaya
Medicine, Science and the Law | Year: 2011

In 1994, the Government of India enacted the Transplantation of Human Organs Act (THOA) to prevent commercial dealings in human organs. However, a greater number of scandals involving medical practitioners and others in the kidney trade has surfaced periodically in every state in India. The present regulatory system has failed mainly due to the misuse of Section 9(3) of the THOA, which approves the consent given by a live unrelated donor for the removal of organs for the reason of affection or attachment towards the recipient or for any other special reason. Currently in India, approximately 3500-4000 kidney transplants and 150-200 liver transplants are performed annually. However, the availability of organs from brain-dead persons is very low. As a result, live related or unrelated donors form the main source of organ transplantation. Therefore, physicians and policy-makers should re-examine the value of introducing regulated incentive-based organ donation to increase the supply of organs for transplantation and to end unlawful financial transaction.

Shahrizaila N.,University of Malaya | Yuki N.,National University of Singapore
Expert Review of Neurotherapeutics | Year: 2011

Guillain-Barré syndrome (GBS) is typically classified into two major subtypes: acute inflammatory demyelinating neuropathy and acute motor axonal neuropathy. Its most recognizable variant is Fisher syndrome. The last two decades have seen considerable advances in our understanding of GBS. Of note, various autoantibodies against ganglioside antigens have been identified and found to have significant associations with the axonal forms of GBS and Fisher syndrome. In this article, we discuss the different clinical presentations in GBS and the role of antiganglioside antibodies in their underlying pathogenesis. We also discuss the impact that antiganglioside antibodies have had in the development of experimental models and treatment modalities in GBS. © 2011 Expert Reviews Ltd.

Tan H.M.,Sime Darby Medical Center | Tan H.M.,University of Malaya | Tong S.F.,National University of Malaysia | Ho C.C.,National University of Malaysia
Journal of Sexual Medicine | Year: 2012

Introduction. Sexual dysfunction in men, such as erectile dysfunction, hypogonadism, and premature ejaculation, generates considerable attention. Its association with physical and psychological health is an issue which should be addressed seriously. Aim. A review of the literature pertaining to the correlation between sexual dysfunction and physical and psychological health. Methods. PubMed search for relevant publications on the association between sexual dysfunction in men and physical and psychological health. Main Outcome Measure. Clinical and epidemiological evidence that demonstrates the association between sexual dysfunction in men and physical and psychological health. Results. Sexual dysfunction, i.e., erectile dysfunction, hypogonadism, and premature ejaculation, has been shown to be associated with physical and psychological health. There is a strong correlation between sexual dysfunction and cardiovascular disease, metabolic syndrome, quality of life, and depression. Conclusion. The association between men's sexual dysfunction and physical and psychological health is real and proven. Therefore, it should not be taken lightly but instead treated as a life-threatening medical problem. © 2011 International Society for Sexual Medicine.

Jalab H.A.,University of Malaya
Information Technology Journal | Year: 2012

This study presents a novel algorithm to recognize a set of static hand gestures for the Human-Computer Interaction (HCI), based on hand segmentation using both wavelet network for images feature extraction, and supervised feed-forward neural network with back propagation training algorithm for recognition. One hundred and twenty hand gesture images were used for training and 60 for testing. The best classification rate of 97% was obtained for the testing set. © 2012 Asian Network for Scientific Information.

Kaur J.,University of Malaya
Journal of Pragmatics | Year: 2011

A key feature of interaction in English as a lingua franca (ELF) is diversity - in the varieties of English spoken, the levels of proficiency displayed and the cultural norms and communicative styles of the participants - which can pose challenges to the process of achieving shared understanding in talk. Research into ELF, however, shows that participants make adept use of interactional practices to both pre-empt and resolve problems of understanding. Additionally, speakers use various " explicitness strategies" (Mauranen, 2007) to enhance the clarity of utterances and promote the comprehensibility of speech. This paper examines further the notion of raising explicitness of expression by looking at some of the self-repair practices of speakers using ELF. Using conversation analysis procedures, 15. h of audio-recorded naturally occurring ELF conversations of international graduate students were analyzed for this purpose. Instances of self-initiated repair were examined to identify the types of repair performed and the kinds of trouble addressed. The results show that in addition to correcting, the participants employ a variety of self-repair practices that make utterances explicit and improve communicative clarity. The speakers' meticulous attention to clarity and explicitness possibly stems from an awareness of the precarious nature of the ELF situation. © 2011 Elsevier B.V.

Shahbaz M.,COMSATS Institute of Information Technology | Salah Uddin G.,Linkoping University | Ur Rehman I.,University of Malaya | Imran K.,Institute of Business Management
Renewable and Sustainable Energy Reviews | Year: 2014

This paper investigates the relationship between industrialization, electricity consumption and CO2 emissions in case of Bangladesh using quarter frequency data over the period of 1975-2010. The ARDL bounds testing approach is applied to examine cointegration in the presence of structural breaks stemming in the series. The causal relationship among the variables is explored by applying the innovative accounting approach (IAA). Our results indicate that the variables are cointegrated for a long run relationship. We find that financial development adds in energy pollutants. Electricity consumption contributes to CO2 emissions. Trade openness also has a positive impact on energy pollutants. The results unveil that EKC is existed between industrial development and CO2 emissions in case of Bangladesh. Our causality analysis shows that electricity consumption Granger causes energy pollutants, industrial growth and financial development. The unidirectional causality exists running from financial development to trade openness and trade openness Granger causes industrial development. This study opens up new insights for policy makers in formulating a comprehensive economic, financial and trade policy to sustain industrialization by improving the environmental quality. © 2014 Elsevier Ltd.

Hutchison C.S.,University of Malaya
Tectonophysics | Year: 2010

Oroclinal bending of Borneo is interpreted to result from indentation and collision by the continental promontory of the Miri Zone-Central Luconia Province of northern Sundaland into southern Sundaland. The collision caused strong compression and uplift of the intervening Sibu Zone Upper Cretaceous-Eocene Rajang-Embaluh Group turbidite basin that was floored by oceanic crust of the Proto South China Sea. Timing of the collision is indicated by uplift of turbidite formations to be overlain by Upper Eocene-Lower Oligocene carbonates and intrusion of tin-mineralised granites into the turbidites at the south-east maximum inflexion of the orocline, a region complicated by juxtaposition of both shallow and deep water formations. The oroclinal model, requiring clockwise rotation of the north-west limb, is given no support from the paleomagnetic data that instead demonstrate about 50° of Cenozoic anti-clockwise rotation. Unfortunately not a single outcrop of the strongly oroclinally bent Sibu Zone rocks was measured for paleomagnetism in the north-west limb. Limited support was given for the required anti-clockwise rotation in the north-east limb. Previous syntheses emphasised anti-clockwise rotation, or stable non-rotation of the greater Borneo region as a coherent entity, without any internal deformation. Such models have ignored the oroclinal shape defined by the areal geology of the island, known since early Dutch publications. The northern Thailand-Myanmar north-south-trending geology fabric results from indentation by a promontory of continental India at the Assam-Yunnan oroclinal syntaxis, resulting in paleomagnetically-determined clockwise rotation. The bend of Peninsular Malaysia and Sumatra, from north-south changing to west-east towards Borneo in the south, remains difficult to model because of widespread remagnetisation. © 2010 Elsevier B.V.

Ooi C.H.R.,University of Malaya | Gong Q.,Peking University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2012

We study the quantum correlation of photon pairs from a double Raman particle driven by laser fields in a modified photon density of states such as a cavity or a defect in a photonic crystal. We obtain an exact semianalytical expression for the photon correlation, which is characterized by two complex decay functions associated with the levels splitting (effective Rabi frequencies) that depend on the control laser field. The position and width of the cavity density of state with respect to the anti-Stokes transition determine the features in the two-photon correlation profile. © 2012 American Physical Society.

Yacob N.A.,University Technology of MARA | Ishak A.,National University of Malaysia | Ishak A.,University of Malaya | Pop I.,Technical University of Cluj Napoca
International Journal of Thermal Sciences | Year: 2011

The steady two-dimensional boundary layer flow past a static or a moving wedge immersed in nanofluids is investigated numerically. An implicit finite difference scheme known as the Keller-box method and the NAG routine DO2HAF are used to obtain the numerical solutions. Three different types of nanoparticles, namely copper Cu, alumina Al2O3 and titania TiO 2 with water as the base fluid are considered. The effects of the governing parameters on the fluid flow and heat transfer characteristics are analyzed and discussed. It is found that Cu-water has the highest skin friction coefficient and the heat transfer rate at the surface compared with the others. The effect of the solid volume fraction of nanoparticles on the fluid flow and heat transfer characteristics is found to be more pronounced compared to the type of the nanoparticles. © 2010 Elsevier Masson SAS. All rights reserved.

Freeman M.A.,University of Malaya | Shinn A.P.,University of Stirling
Parasites and Vectors | Year: 2011

Background: Myxosporeans are known from aquatic annelids but parasitism of platyhelminths by myxosporeans has not been widely reported. Hyperparasitism of gill monogeneans by Myxidium giardi has been reported from the European eel and Myxidium-like hyperparasites have also been observed during studies of gill monogeneans from Malaysia and Japan. The present study aimed to collect new hyperparasite material from Malaysia for morphological and molecular descriptions. In addition, PCR screening of host fish was undertaken to determine whether they are also hosts for the myxosporean. Results: Heavy myxosporean infections were observed in monogeneans from two out of 14 fish and were detected from a further five fish using specific PCRs and pooled monogenean DNA. Positive DNA isolates were sequenced and were from a single species of myxosporean. Myxospore morphology was consistent with Myxidium with histozoic development in the parenchymal tissues of the monogenean. Simultaneous infections in the fish could not be confirmed microscopically; however, identical myxosporean DNA could be amplified from kidney, spleen and intestinal tract tissues using the specific PCR. Small subunit (SSU) rDNA for the myxosporean was amplified and was found to be most similar (92%) to that of another hyperparasitic myxosporean from a gill monogenean from Japan and to numerous multivalvulidan myxosporeans from the genus Kudoa (89-91%). Phylogenetic analyses placed the hyperparasite sequence basally to clades containing Kudoa, Unicapsula and Sphaerospora. Conclusions: The myxosporean infecting the gill monogenean, Diplectanocotyla gracilis, from the Indo-Pacific tarpon, Megalops cyprinoides, is described as a new species, Myxidium incomptavermi, based on a histozoic development in the monogenean host and its phylogenetic placement. We have demonstrated for the first time that a myxosporean hyperparasite of gill monogeneans is detectable in the fish host. However, myxospores could not be isolated from the fish and confirmation was by PCR alone. The relationship between the myxosporean infection in gill monogeneans and the presence of parasitic DNA in fish is not yet fully understood. Nonetheless, myxospores with a Myxidium-like morphology, two of which we have shown to be phylogenetically related, have now been reported to develop in three different gill monogeneans, indicating that myxosporeans are true parasites of monogeneans. © 2011 Freeman and Shinn; licensee BioMed Central Ltd.

Lock J.H.-J.,Royal Perth Hospital | Fong K.C.S.,University of Malaya
Clinical and Experimental Optometry | Year: 2011

Since its discovery in the 1940s, retinal photocoagulation has evolved immensely. Although the first photocoagulators used incandescent light, it was the invention of the laser that instigated the widespread use of photocoagulation for treatment of retinal diseases. Laser permits selection of electromagnetic wavelength, energy levels, spot size and pulse duration. These variables are crucial for accurate targeting of retinal tissue and prevention of detrimental side-effects such as central blind spots. There is ongoing clinical research dedicated to optimising such parameters and many innovative modes of laser delivery are now being offered. Laser photocoagulation is the mainstay of treatment for various retinal and macular diseases. Considering the escalating prevalence of such conditions and widespread use of photocoagulation, it is important for optometrists to grasp the basic principles and be aware of new developments in retinal laser therapy. © 2010 The Authors. Clinical and Experimental Optometry © 2010 Optometrists Association Australia.

Hutchison C.S.,University of Malaya
Marine Geology | Year: 2010

The North-West Borneo Trough is bordered along its south-east margin by a mélange wedge that has been the subject of disagreement with insufficient discussion. Offshore Palawan it has been interpreted as an accretionary prism that has been preserved in place when subduction ceased in the Middle Miocene. It is unconformably overlain by undeformed Upper Miocene to Holocene draping strata. Farther south-west along the Trough, the seismically identical mélange wedge has been named a Major Thrust Sheet System, which was assumed to have been thrust as a nappe north-westwards over the autochthonous Dangerous Grounds terrane of attenuated continental crust of the South China Sea passive margin. The accretionary prism model is the simplest, resulting in interpretation of the North-West Borneo Trough as a fossil trench. Subduction was halted by the rifted and attenuated continental crust arriving at the Benioff Zone, choking subduction and causing isostatic uplift of the Western Cordillera of Sabah. The subduction system therefore became a collision zone resulting in the term 'foredeep', in which case the actual trench position remains obscure and somewhere towards the south-east, but shown in unrestrained geological cartoons. Enigmas remain in the Palawan area of the Philippines. The Trough position is bathymetrically obscure in places and its given position makes it impossible to derive the Calamian micro-continent from continental Asia as required from its stratigraphy. In the south-west, the Trough terminates abruptly at the West Baram Line. The Trough contains several spectacular edifices, formerly suggested to be volcanoes or mud volcanoes but herein shown to be carbonate build-ups that were drowned, indicating that the Trough subsided too fast for build-up continuation, whereas post-rift thermal subsidence of the Dangerous Grounds was slower, allowing the Spratly Islands build-ups to continue active. © 2010 Elsevier B.V. All rights reserved.

Shahrizaila N.,University of Malaya | Yuki N.,National University of Singapore
Expert Opinion on Pharmacotherapy | Year: 2011

Introduction: Guillain-Barré syndrome (GBS) is the most frequent cause of acute flaccid paralysis and, despite treatment, there continues to be an associated mortality and severe disability ranging from 9 to 17%. This article reviews the rationale behind the existing immunotherapy in GBS and discusses the future direction that work in this area should follow. Areas covered: The pathogenesis of GBS and the current evidence for the different forms of immunotherapy in GBS are reviewed. The proposed mechanism of action of each treatment (steroids, plasma exchange and intravenous immunoglobulin (IVIG)) in GBS are discussed. Expert opinion: Both plasma exchange and IVIG are equally effective in GBS although the latter is preferred in view of its ease of access and lower rates of complications. Although not clinically established, there may be a role for the concomitant use of steroids with IVIG and, in patients with severe disease and poor prognostic scores, plasma exchange followed by IVIG or two successive IVIG may prove beneficial. © Informa UK, Ltd.

Islam M.A.,University of Malaya
Journal of the Geological Society of India | Year: 2010

The present study has been carried out for core and log based petrophysical evaluation of subsurface reservoir sandstones considering at least one well from each of the Kailas Tila, Titas, Bakhrabad and Shahbazpur gas fields of Bangladesh. Core analysis results show that average core porosity, permeability and pore throat values are 20%, 209 mD and 44020 Å, respectively. These measured values support that the sandstone reservoirs are categorized as good quality reservoirs. Core porosity values usually exceed thin section porosity. Different cross-plots indicate that permeability is largely dependent on porosity. Permeability and porosity are also dependent on textural parameters that include size, shape, sorting and matrix of the reservoir sandstones. It reveals from both thin section study and different cross plots that diagenetic cements are the main controlling factors of the reservoirs. Quantitative determination of the volume of cements shows that cements have inverse correlation with porosity and permeability. Log based petrophysical parameters include shale volume, porosity, water and hydrocarbon saturation, permeability, moveability index and bulk volume of water. The average values of the mentioned parameters are 20%, 22%, 26%, 74%, 110 mD, 0.28 and 0.05, respectively. The most important parameters are porosity and permeability, which indicate that log porosity exceeds core porosity and log permeability significantly lags behind core permeability. The study also reveals that 23 gas zones covering total thickness of 385 m sandstones mostly posses good quality reservoirs except few moderate quality reservoirs. © 2010 Geological Society of India.

Shahid S.,University of Malaya
International Journal of Climatology | Year: 2010

Spatial patterns of annual and seasonal rainfall trends of Bangladesh over the time period 1958-2007 has been assessed using rainfall data recorded at 17 stations distributed over the country. Mann-Kendall trend test and the Sen's slope method are used to detect the significance and the magnitude of rainfall change, respectively. Historical dry and wet months are identified by using standardised precipitation index method and their trends are analysed to assess the possible change in wet and dry events in Bangladesh. The result shows a significant increase in the average annual and pre-monsoon rainfall of Bangladesh. The number of wet months is found to increase and the dry months to decrease in most parts of the country. Seasonal analysis of wet and dry months shows a significant decrease of dry months in monsoon and pre-monsoon. © 2009 Royal Meteorological Society.

Tan S.H.,University of Malaya
Health and Social Care in the Community | Year: 2016

Disability in a child not only affects the child but also presents socioeconomic and psychological impacts to the child's family. This study aims to describe the service needs of caregivers of children with disabilities in the state of Penang, Malaysia, and to determine the child and family characteristics predisposing to having more caregiver needs. A cross-sectional survey was conducted between February and June 2013 among caregivers of children aged 0-12 years with disabilities registered with the Penang Department of Social Welfare. Caregivers completed a self-administered mailed questionnaire containing a 20-item Caregiver Needs Scale (CNS). Each item in the CNS was rated on a 5-point Likert scale ranging from 'help not at all needed' to 'help extremely needed'. A total of 273 surveys were available for analysis (response rate 34.0%). The CNS contained four domains. The 'Help getting Information and Services for child' domain had the highest mean score (3.61, 95% CI: 3.46, 3.77) followed by 'Help with Finances' (3.29, 95% CI: 3.13, 3.45) and 'Help Coping with child' (3.11, 95% CI: 2.97, 3.25), while the 'Help getting Childcare' domain had the lowest mean score (2.30, 95% CI: 2.13, 2.47). Multivariate regression analysis identified caregivers of younger children and with more severe disability as having more caregiver needs in all domains. Besides that, caregivers of children with learning disability needed more help getting information and help with coping. Caregivers of children with learning and multiple disabilities needed more help getting childcare compared to children with other disability. Caregivers of Indian ethnicity, who had less than a tertiary education and who themselves had medical problems needed more help with finances. The findings on caregiver needs in this study can help inform planning of family support services for children with disabilities in Penang, Malaysia. © 2016 John Wiley & Sons Ltd.

Ooi C.H.R.,University of Malaya
Progress in Electromagnetics Research | Year: 2011

Nonlinear optical processes have been used for sensitive detection of chemicals, optical imaging and spectral analysis of small particles. We have developed an exact theoretical framework to study the angular dependence of coherent anti-Stokes Raman scattering (CARS) intensity in the near field and far field for nanoparticle and microparticle. We obtain exact analytical solution for the CARS signal valid for arbitrary detection distance. Interesting angular dependence is found for nanoparticle, especially with near field detection. The study includes the effects of focused lasers and particle size on the CARS intensity distribution. We find that the detection distance and particle size do not affect the spectroscopic peaks of CARS. However, interference of reflected waves in nanoparticle can produce a dip in the backscattered spectrum.

Wong L.P.,University of Malaya
Australian Journal of Rural Health | Year: 2011

Objective: Study aimed to determine the prevalence of dysmenorrhoea, its impact, and treatment-seeking behaviour of rural adolescent girls in Malaysia. Participants and setting: Large cross-sectional study on 1295 adolescent girls (aged 13-19years) from 16 public secondary schools in rural districts of Kelantan, Malaysia conducted between February 2009 and April 2009. Results: Dysmenorrhoea was reported in 76.0% of the participants. Concentration at school (59.9%) and participation in social events (58.6%) have been most affected. Multivariate analysis shows that being in upper secondary level was the strongest predictor for poor concentration, absenteeism, and poor school grade due to dysmenorrhoea. In spite of its high prevalence and enormous impact on their lives, 76.1% believed that dysmenorrhoea is a normal part of the female menstrual cycle and only 14.8% sought medical treatment. The majority of adolescents obtained information from their mothers (62.3%) and peers (52.9%). Conclusion: The findings imply the need for educating adolescent girls on effective management of dysmenorrhoea. Education should be extended to parents and school peer leaders to address the reproductive health needs of adolescents. © 2011 The Author. Australian Journal of Rural Health © National Rural Health Alliance Inc.

Ramesh S.,University of Malaya | Shanti R.,University Tunku Abdul Rahman | Morris E.,University Tunku Abdul Rahman
Carbohydrate Polymers | Year: 2012

A series of polymer electrolytes composed of corn starch (CS), lithium bis(trifluoromethanesulfonyl)imide (LITFSI) and deep eutectic solvent (DES) were fabricated by solution casting technique. The DES was synthesized from a mixture of choline chloride and urea at a molar ratio of 1:2. The addition of DES is crucial in enhancing the room temperature ionic conductivity by increasing the amorphous elastomeric phase in CS:LITFSI matrix. The ionic transport mechanism is improved and appreciable amount of ion conducting polymer electrolytes is produced. The highest ionic conductivity achieved for the polymer electrolyte composition CS:LiTFSI:DES (14 wt.%:6 wt.%:80 wt.%) is 1.04 × 10-3 S cm-1. The anomalies that were observed with the addition of DES upon formation of neutral ion multiples were visually revealed by the SEM micrographs. The possible dipole-dipole interaction between the constituents was visualized by the FTIR spectroscopy upon change in cage peaks. © 2011 Elsevier Ltd. All Rights Reserved.

Tang C.F.,University of Malaya | Shahbaz M.,COMSATS Institute of Information Technology | Shahbaz M.,College of Economy and Administration
Energy Policy | Year: 2013

This study uses the annual data from 1972 to 2010 to assess the causal relationship between electricity consumption and real output at the aggregate and sectoral levels in Pakistan. This study covers three main economic sectors in Pakistan namely agricultural, manufacturing and services sectors. Our cointegration results reveal that the variables are cointegrated at the aggregate and sectoral levels. At the aggregate level, we find that there is uni-directional Granger causality running from electricity consumption to real output in Pakistan. At the sectoral level, we find that electricity consumption Granger-causes real output in the manufacturing and services sectors. However, there is no causal relationship between electricity consumption and real output in the agricultural sector. The policy implication of these results is that electricity conservation policies in general would deteriorate the process of economic growth as well as the real output in the manufacturing and services sectors in Pakistan. Nevertheless, we suggest the Pakistani government to implement the electricity conservation policies merely to the agricultural sector because such policies may have less or no adverse impact on its real output. © 2013 Elsevier Ltd.

Aziz S.B.,University of Sulaimani | Abidin Z.H.Z.,University of Malaya
Materials Chemistry and Physics | Year: 2014

Solution cast technique is employed to prepare solid polymer electrolyte films based on chitosan (host polymer) and silver triflate (AgCF 3SO3, doping salt) using (1%) acetic acid as a common solvent. The effect of salt concentration on both EP and bulk materials dielectric properties has been analyzed. Physically the original relationship between the bulk dielectric constant and DC conductivity has been interpreted. It is demonstrated that the dielectric constant and dielectric loss values decrease at higher temperatures due to the reduction of silver ions. Scanning electron microscopy (SEM) and energy dispersive analysis of X-ray (EDAX) indicate the presence of metallic silver particles. The ac conductivity spectra shows three distinct regions and obeys the Jonscher's power law at high frequency regions. The temperature dependence of frequency exponent (s) shows the crossover from CBH model to SP model. © 2014 Elsevier B.V. All rights reserved.

Shrivastava K.N.,University of Malaya
AIP Conference Proceedings | Year: 2010

In 1961 Byers and Yang have discovered a theorem of periodicity of energy levels in units of a flux quantum. In superconductors, the quantum unit is hc/2e. In the semiconductors, the pairing does not occur so that the flux quantum is hc/e. We show that Byers and Yang's flux quantization is applicable to the fractional charge, experimentally observed in the quantum Hall effect. It particularly explains the observation of 1/3 charge. The flux quantization also occurs for spin other than 1/2. We find that for spin 3/2 unusual series of large charges are predicted. The charge becomes very large such as 10e, 14e, etc. For example, for S=3/2, (1/2)g=(1/2)+s=2, i.e., g=4 so that (5/2)g=10 and due to flux quantization, the effective charge becomes 10e. The flux quantization gives rise to plateaus and energies become independent of magnetic field. Apparently, the problem becomes independent of charge and the plateaus are then quantized in units of h 2/m, the square of the Planck's constant divided by the mass of the electron. © 2010 American Institute of Physics.

Shrivastava K.N.,University of Malaya
AIP Conference Proceedings | Year: 2010

The Hall Effect has only one e and h/e comes from the flux quantization. At the plateau, the number of electrons is one or a small number. As the field is increased, the number of electrons increases to form a cluster. The increase in the number of electrons can be described by the exponent of the coherence length because the length in the plateau is determined by the flux quantization. This flux quantization is determined by our spin dependent expression. As the field is increased to go out of the area restricted by the flux quantization, length increases which is described by the variation of Hall resistivity as a function of magnetic field, ∂R xy/∂B≈T -0.4 The exponent of 0.4 is 1/ν where ν is the exponent of the coherence length. As the field is further increased the flux quantization interferes again and the cluster breaks down to form another plateau which has either one or a small number of electrons. At the plateau the electrons are Anderson localized (Anderson 1961) except that the charge is determined by our spin-dependent formula. We calculate the reduced mass of a vortex and an electron and from that we determine the size and hence the Hall effect of an electron-vortex two particle state. © 2010 American Institute of Physics.

Natarajan S.,University of Malaya
Genetics and Molecular Biology | Year: 2010

The development of novel therapeutic agents is essential for combating the increasing number of cases of dengue fever in endemic countries and among a large number of travelers from non-endemic countries. The dengue virus has three structural proteins and seven non-structural (NS) proteins. NS3 is a multifunctional protein with an N-terminal protease domain (NS3pro) that is responsible for proteolytic processing of the viral polyprotein, and a C-terminal region that contains an RNA triphosphatase, RNA helicase and RNA-stimulated NTPase domain that are essential for RNA replication. The serine protease domain of NS3 plays a central role in the replicative cycle of dengue virus. This review discusses the recent structural and biological studies on the NS2B-NS3 protease-helicase and considers the prospects for the development of small molecules as antiviral drugs to target this fascinating, multifunctional protein. © 2010, Sociedade Brasileira de Genética.

Wong L.P.,University of Malaya
Journal of pediatric and adolescent gynecology | Year: 2011

Attitudes toward menarche and menstruation are largely influenced by sociological, cultural, and family environmental factors. Recognizing the influential effects that these factors might have on shaping adolescents' attitudes is crucial in designing a more effective means of transmitting health information. This study aimed to gather an in-depth understanding of perceptions, impacts, and treatment seeking on menstruation-related issues from an ethnically mixed group of rural and urban girls. In total, 27 focus group discussions (172 participants) were conducted between November 2008 and April 2009. Participants were adolescent girls aged 13-19 years, recruited from 7 public secondary schools in the Federal Territory of Kuala Lumpur and 4 public secondary schools from the rural districts of Kelantan, in Malaysia. Many participants revealed that they were not given or had not received detailed information about the mechanism or physiology of menstruation prior to its onset. Thus, many described the onset of menarche as shocking, an event for which they were unprepared, and which has had a tremendous impact on their emotions. More positive acceptance of menarche was reported in the urban than with the rural groups. Despite the high prevalence of premenstrual syndrome and dysmenorrhea, participants across urban-rural and ethnic groups perceived the problems as completely normal, hence they relied on self-care methods and did not want to seek professional treatment. More rural girls compared to urban girls were embarrassed to talk to their mothers or consult their physicians regarding menstruation-related problems. Menstruation-related education would have a positive impact in improving adolescent girls' knowledge and in nurturing a positive attitude toward menstruation-related matters at home, at school, and in the community. Copyright © 2011 North American Society for Pediatric and Adolescent Gynecology. Published by Elsevier Inc. All rights reserved.

Yuki N.,National University of Singapore | Shahrizaila N.,University of Malaya
Journal of Biomedicine and Biotechnology | Year: 2011

Molecular mimicry between self and microbial components has been proposed as the pathogenic mechanism of autoimmune diseases, and this hypothesis is proven in Guillain-Barré syndrome. Guillain-Barré syndrome, the most frequent cause of acute neuromuscular paralysis, sometimes occurs after Campylobacter jejuni enteritis. Gangliosides are predominantly cell-surface glycolipids highly expressed in nervous tissue, whilst lipo-oligosaccharides are major components of the Gram-negative bacterium C. jejuni outer membrane. IgG autoantibodies to GM1 ganglioside were found in the sera from patients with Guillain-Barré syndrome. Molecular mimicry was demonstrated between GM1 and lipo-oligosaccharide of C. jejuni isolated from the patients. Disease models by sensitization of rabbits with GM1 and C. jejuni lipo-oligosaccharide were established. Guillain-Barré syndrome provided the first verification that an autoimmune disease is triggered by molecular mimicry. Its disease models are helpful to further understand the molecular pathogenesis as well as to develop new treatments in Guillain-Barré syndrome. Copyright © 2011 Nortina Shahrizaila and Nobuhiro Yuki.

Wong L.P.,University of Malaya | Sam I.-C.,Tropical Infectious Diseases Research and Education Center
European Journal of Obstetrics Gynecology and Reproductive Biology | Year: 2010

Objective: Cervical HPV is the most common sexually transmitted disease among college-age women. This study aimed to assess knowledge and attitudes towards HPV infection, HPV vaccination and cervical cancer among female university students, to provide insight into development of HPV educational information. Study design: A cross-sectional survey using a convenience sample. A total of 1083 ethnically diverse female students attending a public university were approached and 650 were interviewed. Results: Knowledge regarding HPV, HPV vaccination, cervical screening and cervical cancer risk factors was remarkably poor. Across the sample, the mean total knowledge score (14-item) was only 3.25 (S.D. ±2.41; 95% CI 3.07-3.44). Only 10.3% had heard of the newly released HPV vaccine. Approximately 48% of participants indicated an intention to receive an HPV vaccine. Intention to receive an HPV vaccine was significantly associated with knowledge of HPV and genital warts (OR 1.53; 95% CI 1.25-1.88), and knowledge of cervical screening and cervical cancer risk factors (OR 1.21; 95% CI 1.11-1.33). Of those who refused HPV vaccination, 50.9% doubted the safety and efficacy of the new vaccine, and 41.5% perceived themselves as not at risk of HPV infection. Conclusion: The findings suggest that providing education about the etiology of cervical cancer and the HPV link is an essential component to enhance HPV vaccine uptake. © 2009 Elsevier Ireland Ltd. All rights reserved.

Samberkar P.N.,University of Malaya
American Journal of Forensic Medicine and Pathology | Year: 2012

The victim, a 63-year-old prosperous businessman from Labasa, of the Northern Island (Vanua Levu) of Fiji Islands, was found completely decapitated in the early hours of morning in 2004. Initial police investigation did not reveal any history of any medical or family calamity. Further inquiry by the police revealed that on the previous day the deceased had visited all his friends and relatives, and his behavior was not out of the ordinary. The police suspected it to be a case of homicide. On visit to the scene, a completely decapitated body was found in a van on a downhill road. Tire marks were found on the road. A nylon rope was used for ligature strangulation. At autopsy, the decapitation wound of the head and the torso articulated well. The face was congested, and there was tongue bite. Wound margins were clear-cut, with well-demarcated abrasion and multiple imprints of the nylon rope on the neck. The upper one third of the larynx was attached to the head. No other injuries were found on the body. From the findings, it was obvious that asphyxiation was involved in the death before decapitation. Copyright © 2012 Lippincott Williams & Wilkins.

Lee Y.Y.,Universiti Sains Malaysia | Tee H.-P.,Hospital Tengku Ampuan Afzan | Mahadeva S.,University of Malaya
World Journal of Gastroenterology | Year: 2014

Bacterial infections are common in cirrhotic patients with acute variceal bleeding, occurring in 20% within 48 h. Outcomes including early rebleeding and failure to control bleeding are strongly associated with bacterial infection. However, mortality from variceal bleeding is largely determined by the severity of liver disease. Besides a higher Child-Pugh score, patients with hepatocellular carcinoma are particularly susceptible to infections. Despite several hypotheses that include increased use of instruments, greater risk of aspiration pneumonia and higher bacterial translocation, it remains debatable whether variceal bleeding results in infection or vice versa but studies suggest that antibiotic prophylaxis prior to endoscopy and up to 8 h is useful in reducing bacteremia and spontaneous bacterial peritonitis. Aerobic gram negative bacilli of enteric origin are most commonly isolated from cultures, but more recently, gram positives and quinolone-resistant organisms are increasingly seen, even though their clinical significance is unclear. Fluoroquinolones (including ciprofloxacin and norfloxacin) used for short term (7 d) have the most robust evidence and are recommended in most expert guidelines. Short term intravenous cephalosporin (especially ceftriaxone), given in a hospital setting with prevalent quinolone-resistant organisms, has been shown in studies to be beneficial, particularly in high risk patients with advanced cirrhosis. © 2014 Baishideng Publishing Group Co., Limited. All rights reserved.

Shahid S.,University of Malaya | Hazarika M.K.,Asian Institute of Technology
Water Resources Management | Year: 2010

Prolonged absence of groundwater within the operating range of shallow tube-wells during dry season is a common problem in the northwestern districts of Bangladesh in the recent years. In this paper, groundwater scarcity and drought in three northwestern districts of Bangladesh have been investigated. The Cumulative Deficit approach from a threshold groundwater level has been used for the computation of severity of groundwater droughts. Monthly groundwater fluctuation data collected from 85 sites is used for the study. The study shows that groundwater scarcity in 42% area is an every year phenomenon in the region. Analysis of groundwater hydrographs and rainfall time-series reveals that ever increasing groundwater extraction for irrigation in the dry season and recurrent droughts are the causes of groundwater level drop in the region. © 2009 Springer Science+Business Media B.V.

Tiekink E.R.T.,University of Malaya | Zukerman-Schpector J.,Federal University of Sao Carlos
Chemical Communications | Year: 2011

Crystal structures of transition and main group element 1,1-dithiolates are shown to be partially sustained by C-H⋯π(chelate) interactions. For the planar binary bisdithiocarbamates, C-H⋯π(MS2C) interactions lead to aggregation patterns ranging from a 0-D four molecule aggregate to a 3-D architecture but with the majority of structures featuring 1-D or 2-D supramolecular assemblies. © 2011 The Royal Society of Chemistry.

Yee A.,University of Malaya
Expert Review of Neurotherapeutics | Year: 2016

Brexpiprazole (OPC-34712) is a novel serotonin-dopamine activity modulator, which has recently been approved by the U.S Food and Drug Administration for the treatment of schizophrenia. The aim of this paper is to systematically synthesize all data of the efficacy, safety and tolerability of Brexpiprazole in treating schizophrenia. The terms 'Brexpiprazole', 'OPC-34712' and 'schizophrenia' were searched. A total of 12 clinical trials with 7 available data records were found. The pooled effect size of Brexpiprazole 1 mg, 2 mg and 4 mg were all superior to placebo in terms of the change from baseline in positive and negative syndrome scale (PANSS) total score at week 6 (weighted mean difference = -3.74, p = 0.044; weighted mean difference = -5.76, p < 0.01 and weighted mean difference = -7.03, p < 0.01, respectively) when compared to that of the placebo in treating acute schizophrenia. Brexpiprazole displays a good safety and tolerability profile. The incidence of akathisia, headache, insomnia, sedation, agitation, diarrhea, weight gained, nausea, and dyspepsia are comparable to placebo. © 2016 Taylor & Francis.

Zukerman-Schpector J.,Federal University of Sao Carlos | Otero-De-La-Roza A.,University of Oviedo | Luana V.,University of Oviedo | Tiekink E.R.T.,University of Malaya
Chemical Communications | Year: 2011

As(lone pair)⋯π interactions provide stability to their crystal structures often leading to supramolecular chains and prevailing over As⋯X secondary contacts. The interaction (ca 8 kJ mol-1) arises from polarisation induced in the aryl ring by the As-lone pair plus the weak sharing of these electrons with the ring-C atoms. © 2011 The Royal Society of Chemistry.

Thabit H.,University of Cambridge | Thabit H.,University of Malaya | Hovorka R.,University of Cambridge
Endocrinology and Metabolism Clinics of North America | Year: 2012

Advances in diabetes technology have led to significant improvements in the quality of life and care received by individuals with diabetes. Despite this, achieving tight glycemic control through intensive insulin therapy and modern insulin regimens is challenging because of the barrier of hypoglycemia, the most feared complication of insulin therapy as reported by patients, caregivers, and physicians. This article outlines the individual components of the closed-loop system together with the existing clinical evidence. The artificial pancreas prototypes currently used in clinical studies are reviewed as well as obstacles and limitations facing the technology. © 2012 Elsevier Inc.

Sun Z.,Curtin University Australia | Ng K.-H.,University of Malaya
European Journal of Radiology | Year: 2012

Purpose: To perform a systematic review of the radiation dose and diagnostic accuracy of prospective versus retrospective ECG-gated multislice CT coronary angiography. Materials and methods: A search of Pubmed/Medline and Sciencedirect databases for English literature was performed to identify studies comparing prospective and retrospective ECG-gated multislice CT angiography in the diagnosis of coronary artery disease. Effective dose, dose length product, image quality and diagnostic value were compared between two groups of studies. Results: 22 studies were included for analysis. The mean effective dose of prospective ECG-gated scans was 4.5 mSv (95% CI: 3.6, 5.3 mSv), which is significantly lower than that of retrospective scans, which is 13.8 mSv (95% CI: 11.5, 16.0 mSv) (p < 0.001). The mean dose length product was 225 mGy cm (95% CI: 188, 262 mGy cm) and 822 mGy cm (95% CI: 630, 1013 mGy cm) for the prospective and retrospective ECG-gated scans, respectively, indicating a statistically significant difference between these two protocols (p < 0.0001). The mean sensitivity and specificity of multislice CT angiography in the diagnosis of coronary artery disease was 97.7% (95% CI: 93.7%, 100%) and 92.1% (95% CI: 87.2%, 97%) for prospective ECG-gated scans; 95.2% (95% CI: 91%, 99.5%) and 94.4% (95% CI: 88.5%, 100%) for retrospective ECG-gated scans, respectively, with no significant difference for sensitivity but significant difference for specificity (p = 0.047). Conclusion: Multislice CT coronary angiography with prospective ECG-gating leads to a significant reduction of radiation dose when compared to that of retrospective ECG-gating, while offering comparable image quality and diagnostic value. © 2011 Elsevier Ireland Ltd. All rights reserved.

Zainal Abidin N.I.,University of Queensland | Zainal Abidin N.I.,University of Malaya | Martin D.,University of Queensland | Atrens A.,University of Queensland
Corrosion Science | Year: 2011

This work compared the corrosion of typical Mg alloys (AZ91, ZE41 and Mg2Zn0.2Mn) and high purity (HP) Mg in Hank's solution at room temperature and in 3% NaCl saturated with Mg(OH)2. Corrosion was characterised by the evolved hydrogen and the surfaces after immersion. Corrosion in Hank's solution was weakly influenced by microstructure in contrast to corrosion in the 3% NaCl solution. This is attributed to the formation of a more protective surface film in Hank's solution, causing extra resistance between the α-Mg matrix and the second phase. The alloys with substantial Zn contents had a shorter incubation period in Hank's solution. © 2010 Elsevier Ltd.

Wong Y.M.,Laboratory of Advanced Catalysis and Environmental Technology | Wu T.Y.,University of Selangor | Juan J.C.,Laboratory of Advanced Catalysis and Environmental Technology | Juan J.C.,University of Malaya
Renewable and Sustainable Energy Reviews | Year: 2014

In recent years, the production of hydrogen (H2) via dark fermentation has become increasingly popular because it is a sustainable approach to produce clean energy. This review presents an overview with a critical analysis of the technical challenges in obtaining high H2 yield through dark fermentation. Particular focus is given to the pretreatment methods that affect H2 production. We observed that heat pretreatment is the most frequently applied and the most effective method of eliminating H2-consuming bacteria (HCB) while preserving H2-producing bacteria (HPB). The pre-dominant HPB species after pretreatment belongs to the genus Clostridium and hence the fermentation conditions are optimized according to their preference for H2 production. Besides, we also reviewed fermentation conditions such as substrate, pH, temperature, oxidation-reduction potential (ORP), types of nutrient and inhibitor substrate, to obtain clearer insight on the influences of critical parameters in H2 production. © 2014 Elsevier Ltd.

The genus Pongo has a relatively richer Quaternary fossil record than those of the African great apes. Fossil materials are patchy in terms of anatomical parts represented, limited almost exclusively to isolated teeth, jaw and bone fragments. Fossil evidence indicates that the genus Pongo had a broadly continuous distribution across the southern part of the Indomalayan biogeographic region, ranging in time from Early Pleistocene to Holocene: southern China (77 fossil sites), Vietnam (15), Laos (6), Cambodia (2), Thailand (4), Peninsular Malaysia (6), Sumatra (4), Borneo (6) and Java (4). Within this distribution range, there are major geographical gaps with no known orangutan fossils, notably central and southern Indochina, central and southern Thailand, eastern Peninsular Malaysia, northern and southern Sumatra, and Kalimantan. The geological time and place of origin of the genus remain unresolved. Fossil orangutan assemblages usually show greater extent of dental metrical variation than those of modern-day populations. Such variability shown in prehistoric populations has partially contributed to confusion regarding past taxonomic diversity and systematic relationships among extinct and living forms. To date, no fewer than 14 distinct taxa have been identified and named for Pleistocene orangutans. Clear cases suggestive of predation by prehistoric human are few in number, and limited to terminal Pleistocene–Early Holocene sites in Borneo and a Late Pleistocene site in Vietnam. © 2015, Japan Monkey Centre and Springer Japan.

Mohd Zain S.N.,University of Malaya | Behnke J.M.,University of Nottingham | Lewis J.W.,Royal Holloway, University of London
Parasites and Vectors | Year: 2012

Background: The prevalence of parasitic infections among commensal animals such as black and brown rats in many tropical countries is high and in comparison with studies on rodents in temperate climates, little is known about the community structure of their parasites. Rodent borne parasites pose threats to human health since people living in close proximity to rodent populations can be exposed to infection. Methods. The helminth community structures of two urban rat populations in Kuala Lumpur, Malaysia were investigated. The rats were from two contrasting sites in the city caught over a period of 21 months in 2000-2002. Results: Eleven species of helminth parasites comprising seven nematodes (Heterakis spumosum, Mastophorus muris, Nippostrongylus brasiliensis, Syphacia muris, Pterygodermatites tani/whartoni, Gongylonema neoplasticum, Angiostrongylus malaysiensis), three cestodes (Hymenolepis (Rodentolepis) nana, H. diminuta and Taenia taeniaeformis) and one acanthocephalan (Moniliformis moniliformis) were recovered from 346 Rattus rattus and 104 R. norvegicus from two urban sites, Bangsar and Chow Kit, during 2000-2002. Rattus rattus harboured over 60% of all helminths compared with R. norvegicus, although both host species played a dominant role in the different sites with, for example R. norvegicus at Bangsar and R. rattus at Chow Kit accounting for most of the nematodes. Overall 80% of rats carried at least one species of helminth, with the highest prevalences being shown by H. diminuta (35%), H. spumosum (29.8%) and H. nana (28.4%). Nevertheless, there were marked differences in prevalence rates between sites and hosts. The influence of extrinsic (year, season and site) and intrinsic (species, sex and age) factors affecting infracommunity structure (abundance and prevalence of infection) and measures of component community structure were analyzed. Conclusions: Since at least two species of rat borne helminths in Kuala Lumpur have the potential to infect humans, and these showed high prevalences in the rats, the assessment and regular monitoring of infections carried by wild rodents have important roles to play in public health. © 2012 Mohd Zain et al; licensee BioMed Central Ltd.

Kristmundsson A.,University of Iceland | Freeman M.A.,University of Malaya
Parasites and Vectors | Year: 2013

Background: Approximately 40 species of Sphaeromyxa have been described, all of which are coelozoic parasites from gall bladders of marine fish. They are unique amongst the myxosporeans as they have polar filaments that are flat and folded instead of being tubular and spirally wound. This unusual feature was used as a subordinal character to erect the suborder Sphaeromyxina, which contains one family, the Sphaeromyxidae, and a single genus Sphaeromyxa. Methods. In the present study, we examine eelpout from the genus Lycodes from Iceland for the presence of myxosporean parasites in the gall bladder and perform morphological and DNA studies. Results: A novel myxosporean, Sphaeromyxa lycodi n. sp., was identified in the gall bladders of five of the six species of Lycodes examined, with a prevalence ranging from 29 - 100%. The coelozoic plasmodia are large, polysporous and contain disporic pansporoblasts and mature spores which are arcuate. The pyriform polar capsules encase long and irregularly folded ribbon-like polar filaments. Each spore valve has two distinct ends and an almost 180°twist along the relatively indistinct suture line. The single sporoplasm is granular with two nuclei. Sphaeromyxa lycodi is phylogenetically related to other arcuate sphaeromyxids and is reproducibly placed with all known sphaeromyxids and forms part of a robustly supported clade of numerous myxosporean genera which infect the hepatic biliary systems of a wide range of hosts. Conclusions: Sphaeromyxa lycodi is a common gall bladder myxosporean in eelpout of the genus Lycodes from Northern Iceland. It has characteristics typical of the genus and develops arcuate spores. Molecular phylogenetic analyses confirm that sphaeromyxids form a monophyletic group, subdivided into straight and arcuate spore forms, within the hepatic biliary clade that infect a wide range of freshwater associated animals. The ancestral spore form for the hepatic biliary clade was probably a Chloromyxum morphotype; however, sphaeromyxids have more recently evolved from an ancestor with a spindle-shaped Myxidium spore form. We recommend that the suborder Sphaeromyxina is suppressed; however, we retain the family Sphaeromyxidae and place it in the suborder Variisporina. © 2013 Kristmundsson and Freeman; licensee BioMed Central Ltd.

Cheah Y.K.,University of Malaya
Malaysian Journal of Medical Sciences | Year: 2013

Background: In light of the fact that chronic diseases were becoming more prevalent recently, the primary objective of the study was to examine the socio-demographic, health, and lifestyle determinants of the use of preventive medical care in Penang, Malaysia. Methods: The study used the primary survey data in Penang which had a total of 398 respondents. Respondents were chosen based on convenient sampling, and the survey was carried out in various locations in Penang. During the survey, the designed questionnaires were distributed for self-administration by the respondents between August and October, 2010. The binary logistic regression model was employed for statistical analysis. Results: Socio-demographic and health factors like income, marital status, education, history of serious family illnesses and self-perceived health status were statistically significant in affecting the likelihood of using preventive medical care. Specifically, being married (OR: 1.94; 95% CI: 1.13, 3.32), the presence of a history of serious family illnesses (OR: 2.14; 95% CI: 1.37, 3.36), having high income (OR: 8.71; 95% CI: 1.03, 73.59) and self-perceived poor health status (OR: 4.78; 95% CI: 1.09, 21.00) were positively related with using preventive medical care. However, having low educational background (OR: 0.23; 95% CI: 0.06, 0.95) were inversely related to the probability of using such medical care. Conclusion: In view of the findings, the individuals' socio-demographic and health profiles were suggested to be given attention by the public health authorities if the goals of increasing the use of preventive medical care in the community were to be achieved. © Penerbit Universiti Sains Malaysia, 2013.

Wong L.P.,University of Malaya
Transplantation Proceedings | Year: 2010

Background: In-depth understanding of cultural and religious factors limiting organ donation of three ethnic populations (Malay, Chinese, and Indian) in Southeast Asia is lacking. Identification of factors limiting organ donation among these three ethnic groups will provide insights into culturally appropriate strategies to promote acceptance of organ donation in a multiethnic Asian community. Methods: A total of 17 focus group discussions (105 participants) were conducted between September and December 2008. Participants were members of the general public aged 18 to 60 years, recruited through convenient sampling around the Klang Valley area of Malaysia. Results: Although the majority had favorable attitudes toward deceased organ donation and transplantation, a diversity of myths and misinformation were unearthed from the discussions across the ethnic groups. These include perceived religious prohibition, cultural myths and misperceptions, fear of disfigurement, fear of surgery, distrust of the medical system, and family disapproval. Culture and religious beliefs played important prohibitive roles among those opposed to organ donations. There were distinctive ethnic differences in cultural and religious concerns regarding organ donation. Less-educated and rural groups appeared to have more misconceptions than the well-educated and the urban groups. Conclusion: Our findings may assist organ donation and transplantation organizations to reach diverse sociodemographic and ethnic communities with culture-specific information about organ donation. The involvement of community and religious leaders is critical in organ donation requests. © 2010 Elsevier Inc. All rights reserved.

Arulsamy A.D.,University of Malaya
Indian Journal of Physics | Year: 2014

We systematically explore and show the existence of finite-temperature continuous quantum phase transition (T C QPT) at a critical point, namely, during solidification or melting such that the first-order thermal phase transition is a special case withinT C QPT. In fact,T C QPT is related to chemical reaction where quantum fluctuation (due to wavefunction transformation) is caused by thermal energy and it can occur maximally for temperatures much higher than 0 K. To extract the quantity related toT C QPT, we use the ionization energy theory and the energy-level spacing renormalization group method to derive the energy-level spacing entropy, renormalized Bose-Einstein distribution and the time-dependent specific heat capacity. This work unambiguously shows that the quantum phase transition applies for any finite temperatures. © 2014 Indian Association for the Cultivation of Science.

Zaharan N.L.,University of Malaya | Williams D.,Royal College of Surgeons in Ireland | Bennett K.,St Jamess Hospital
British Journal of Clinical Pharmacology | Year: 2013

Aims: (i) To examine the incidence of new onset treated diabetes in patients treated with different types of statins and (ii) the relationship between the duration and dose of statins and the subsequent development of new onset treated diabetes. Methods: A retrospective cohort study was performed using the Irish Health Services Executive Primary Care Reimbursement Services national pharmacy claims database. Individuals who received any medicines were identified from January 2001 to January 2009 (n = 1235671). Patients newly treated with statins from 1 January 2002 to 31 December 2007 were identified (n = 239628). Cases were identified as individuals newly treated with antidiabetic medication (n = 38503). Adjusted hazards ratios (HR) with 95% confidence intervals (CI) were calculated to examine the association between statins (any vs. none) and time to new onset treated diabetes using Cox proportional hazard regression. The dose and duration response relationship between statins and new onset treated diabetes was examined using restricted spline functions to assess the linearity of the relationship. Results: Statin use was associated with an increased risk of new onset treated diabetes (HR = 1.18, 95% CI 1.15, 1.22). Increased risk of new onset treated diabetes was found with rosuvastatin (HR = 1.41, 95% CI 1.31, 1.52), atorvastatin (HR = 1.23, 95% CI 1.19, 1.27) and simvastatin (HR = 1.15, 95% CI 1.05, 1.25). There were statistically significant overall dose and duration effects for all statins, excepting fluvastatin, which only demonstrated a duration effect. Conclusion: An increased risk of new onset treated diabetes was found in those treated with statins showing significant duration and dose effect. Further study is required to confirm this association. © 2012 The British Pharmacological Society.

Tee M.Y.,University of Malaya | Karney D.,University of Kansas
International Journal of Computer-Supported Collaborative Learning | Year: 2010

Research on knowledge cultivation often focuses on explicit forms of knowledge. However, knowledge can also take a tacit form-a form that is often difficult or impossible to tease out, even when it is considered critical in an educational context. A review of the literature revealed that few studies have examined tacit knowledge issues in online learning environments. The purpose of this study was to develop a greater understanding of the conditions and processes that help promote the sharing or cultivation of tacit knowledge in a formal online course setting. Using naturalistic inquiry as the methodology of this study, an online graduate business course offered at a private, non-profit United States-based university was purposively selected as the research site. The study found that the online course encouraged processes and created conditions consistent with Nonaka's model of knowledge creation and the concept of ba (or shared context)-encouraging students to share, and to construct knowledge through socialization, externalization, combination, and internalization. The results suggest that purposefully developing a ba-like environment may be a useful approach to facilitating online learning, creating a strong potential to support learning processes necessary for students to cultivate tacit knowledge. © 2010 International Society of the Learning Sciences, Inc.; Springer Science + Business Media, LLC.

Keshavarz Moraveji M.,Arak University | Mohammadi Ardehali R.,Arak University | Ijam A.,University of Malaya
International Communications in Heat and Mass Transfer | Year: 2013

For improvement in information technology (IT), removing heat from electrical devices is an important factor, and current activities try to investigate (numerically, experimentally) new methods of thermal load managing. Mini-channel liquid cooling is one of the candidates for this purpose. Nanofluid as an innovative heat-transfer fluid was used in mini-channel heat sink. Modeling analyzed in this study is a mini-channel heat sink with 20×20mm bottom. For this purpose, five nanoparticle volume fractions namely 0.8, 1.6, 2.4, 3.2 and 4% in five inlet velocities for both types of nanoparticle containing TiO2 and SiC were used. Furthermore, effect of a nanoparticle volume fraction on the convective heat transfer coefficient was investigated in different Reynolds numbers. Modeling results were compared with reference analytical calculations. In addition according to the modeling results, correlated equations were obtained for Nusselt number and friction factor, and its accuracies were acceptable. © 2012 Elsevier Ltd.

Moradiya Y.,SUNY Downstate Medical Center | Janjua N.,University of Malaya
Journal of Stroke and Cerebrovascular Diseases | Year: 2013

Background: Recent studies comparing the outcomes of wake-up stroke (WUS) and stroke while awake (SWA) patients reveal better outcomes among SWA patients, attributable in part to their higher rates of thrombolysis. Patients with WUS are largely excluded from therapy. Earlier analyses, conducted before the approval of alteplase for acute stroke, show the true divergence of natural histories between these 2 groups. Methods: We analyzed 17,398 patients with ischemic stroke from the International Stroke Trial and compared both presentations and outcomes between the WUS and SWA groups. Severity was assessed by level of consciousness, Oxfordshire Community Stroke Project (OCSP) stroke classification, number of neurologic deficits, and predicted probability of dependency or death. Outcomes were assessed at day 14 and at 6 months. Outcome assessments were controlled for potential confounders. Results: WUS represented 29.6% of all ischemic strokes. More severe OSCP stroke type (total anterior circulation syndrome) was less common in WUS. Although more patients with WUS were alert at presentation with a lower predicted probability of dependency, the 14-day mortality rates and rates of poor outcome at 6 months were similar between the 2 groups. Conclusions: WUS patients comprise one quarter to one third of ischemic stroke patients. Despite their more benign presentations, they deteriorate to outcome rates similar to SWA. Although they are typically excluded from time-dependent acute interventions, patients with WUS may benefit from acute intervention to prevent this worsening natural history. © 2013 Elsevier B.V. All rights reserved.

Zainal N.Z.,University of Malaya | Zainal N.Z.,University of Cambridge | Booth S.,University of Cambridge | Huppert F.A.,University of Cambridge
Psycho-Oncology | Year: 2013

Objective This study aims to investigate the evidence of the efficacy of mindfulness-based stress reduction (MBSR) in improving stress, depression and anxiety in breast cancer patients. Methods An extensive systematic electronic review (PubMed, Embase, CINAHL, PsyArticles, PsycINFO, Scopus, Ovid, Web of Science and The Cochrane Library) and a hand search were carried out from 15 October 2011 to 30 November 2011 to retrieve relevant articles using 'mindfulness' or 'mindfulness-based stress reduction' and 'breast cancer' as keywords. Information about the baseline characteristics of the participants, interventions and findings on perceived stress, depression and anxiety was extracted from each study. Results Nine published studies (two randomised controlled trials, one quasi-experimental case-control study and six one-group, pre-intervention and post-intervention studies) up to November 2011 that fulfilled the inclusion criteria were analysed. The pooled effect size (95% CI) for MBSR on stress was 0.710 (0.511-0.909), on depression was 0.575 (0.429-0.722) and on anxiety was 0.733 (0.450-1.017). Conclusion On the basis of these findings, MBSR shows a moderate to large positive effect size on the mental health of breast cancer patients and warrants further systematic investigation because it has a potential to make a significant improvement on mental health for women in this group. Copyright © 2012 John Wiley & Sons, Ltd. Copyright © 2012 John Wiley & Sons, Ltd.

Siddiqui K.A.,University of Lucknow | Tiekink E.R.T.,University of Malaya
Chemical Communications | Year: 2013

Hydrogen bonding in the form of eight-membered {⋯HCNM}2 synthons is identified in the crystal structures of nickel and copper complexes. These C-H⋯M interactions lead to the formation of well-defined zero-, one- and even two-dimensional supramolecular aggregation patterns. © The Royal Society of Chemistry 2013.

Wong L.P.,University of Malaya
Journal of Community Health | Year: 2011

The study was conducted to investigate issues surrounding human papillomavirus (HPV) vaccine delivery in a multi-ethnic, multi-religious and multi-cultural society. A qualitative in-depth interview study was conducted with a sample of 20 physicians. Physicians described the success of HPV vaccines recommendation as very poor. Many expressed reluctance to offer the vaccine to preadolescents. The most notable barrier to vaccination was the vaccine's high cost. Parents of eligible vaccinees were concerned about the efficacy and side effects of the new vaccine, while adult women have low risk perception for HPV infection. Promoters and inhibitors of HPV vaccination in our multi-ethnic, multi-religious and multi-cultural community were identified. This study suggests the need to strengthen the infrastructure necessary for HPV vaccine delivery and to specifically target poor underserved women. © 2010 Springer Science+Business Media, LLC.

Anantharaj R.,University of Malaya | Banerjee T.,Indian Institute of Technology Guwahati
Journal of Chemical and Engineering Data | Year: 2013

1-Ethyl-3-methylimidazolium-based ionic liquid with acetate [OAc], ethylsulfate [EtSO4], and methyl sulfonate [MeSO3] anions was used to generate the liquid-liquid equilibrium (LLE) data for the quaternary mixture of IL (1)-thiophene (2)-pyridine (3)-pentane (4). The selectivity and distribution coefficient values were calculated to evaluate the effectiveness of the simultaneous extraction of thiophene and pyridine from pentane at ambient conditions. The experimental tie-line data were successfully validated by the nonrandom two liquid (NRTL) and universal quasi-chemical (UNIQUAC) models, giving root mean square deviation (RMSD) values less than 1 % for all the systems. The novelty of the work was that a conductor like screening model for real solvents (COSMO-RS) model was used to predict compositions of quaternary systems. However, it failed to reproduce the slope of the tie-lines at high solute concentration, especially for the ionic liquid rich phase. The COSMO-RS predictions gave a RMSD of 4.62 % ([EMIM][OAc]), 5.3 % ([EMIM][EtSO 4]), and 6.07 % ([EMIM][MeSO3]). © 2013 American Chemical Society.

Varkkey H.,University of Malaya
Environmental Hazards | Year: 2013

Since 1982, haze pollution has become an almost annual occurrence in Southeast Asia, with the worst episodes being in the period of 1997-1998 and in 2006-2007. Haze originates from peat and forest fires, mostly in Indonesia. The negative effects of haze can be observed at the global level, with increased carbon emissions exacerbating climate change, and more importantly at the regional level, with serious environmental and socioeconomic effects in Indonesia and its neighbouring countries. Most of these fires are manmade, and can be traced back to land-clearing activities of commercial oil palm plantations. This article questions why these companies have been able to burn with such impunity, even though using fire for land clearing is against Indonesian law. It argues that local and foreign plantation companies have cultivated strong patronage linkages with key patrons among the ruling elite. Hence, patrons are encouraged to protect their clients from the repercussions of their actions. This weakens the power of the state in terms of law enforcement, where national laws against the use of fire are thus rendered useless in the face of powerful economic interests. Well-connected companies therefore continue to use fire as a cost-efficient way to clear land while disregarding its serious environmental and socioeconomic implications. © 2013 Taylor & Francis.

Anantharaj R.,University of Malaya | Banerjee T.,Indian Institute of Technology Guwahati
AIChE Journal | Year: 2013

The tie-line composition of three quaternary system namely 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc]) ([EMIM][OAc]) (1)+thiophene (2)+pyridine (3)+toluene (4), 1-ethyl-3-methylimidazolium ethylsulphate ([EMIM][EtSO4]) (1)+thiophene (2)+pyridine (3)+toluene (4), 1-ethyl-3-methylimidazolium methylsulphonate ([EMIM][MeSO3]) (1)+thiophene (2)+pyridine (3)+toluene (4) were experimentally determined at 298.15 K. The measured tie-line data were successfully correlated with the nonrandom two liquid and UNIversal QUAsiChemical model prediction which gave less than 1% root mean square deviation (RMSD). [EMIM][MeSO3] looks to be a promising solvent for the simultaneous separation having distribution ratios less than unity for both thiophene and pyridine. The quantum chemical-based conductor like screening model for real solvent (COSMO-RS) model was then used to predict the tie-line composition of quaternary systems. COSMO-RS gave the RMSD for the studied systems to be 8.41, 8.74, and 6.53% for the ionic liquids, respectively. © 2013 American Institute of Chemical Engineers.

Chan S.P.,University of Malaya | Colagiuri S.,University of Sydney
Diabetes Research and Clinical Practice | Year: 2015

Aims: Sulfonylureas are well positioned in treating type 2 diabetes, after lifestyle modification and metformin. The sulfonylurea gliclazide was given preference over glibenclamide in older people with type 2 diabetes in the World Health Organization model list of essential medicines. Consequently, a systematic review and meta-analysis of randomized controlled trials of the efficacy and safety of gliclazide versus other oral insulinotropic agents (sulfonylureas, dipeptidyl peptidase-4 inhibitors, and glinides) was performed. Methods: Two reviewers searched MEDLINE for studies of ≥12 weeks duration in adults with type 2 diabetes. The key search word was "gliclazide", filtered with "randomized controlled trial", "human" and "19+ years". Differences were explored in mean change in glycated hemoglobin (HbA1c) from baseline (primary outcome) and risk of hypoglycemia (secondary outcome) between gliclazide and other oral insulinotropic agents; and other sulfonylureas. Results: Nine out of 181 references reported primary outcomes, of which 7 reported secondary outcomes. Gliclazide lowered HbA1c more than other oral insulinotropic agents, with a weighted mean difference of -0.11% (95%, CI -0.19 to -0.03%, P = 0.008, I2 = 60%), though not more than other sulfonylureas (-0.12%; 95%, CI -0.25 to 0.01%, P = 0.07, I2 = 77%). Risk of hypoglycemia with gliclazide was not different to other insulinotropic agents (RR 0.85; 95%, CI 0.66 to 1.09, P = 0.20, I2 = 61%) but significantly lower than other sulfonylureas (RR 0.47; 95%, CI 0.27 to 0.79, P = 0.004, I2 = 0%). Conclusion: Compared with other oral insulinotropic agents, gliclazide significantly reduced HbA1c with no difference regarding hypoglycemia risk. Compared with other sulfonylureas, HbA1c reduction with gliclazide was not significantly different, but hypoglycemia risk was significantly lower. © 2015 Elsevier Ireland Ltd.

Chong H.-Y.,University Tunku Abdul Rahman | Lam W.-H.,University of Malaya
Renewable and Sustainable Energy Reviews | Year: 2013

The need for renewable energy is a global demand due to both the economic factors and the environmental concerns. Malaysian government has been supportive on the research and development in the renewable energies. Renewable Energy Act (2011) and Sustainable Energy Development Authority Act (2011) have been enacted to boost the industry of renewable energy. This paper presents the current status and future prospects of renewable energy in Malaysia with particular focus on the ocean renewable energy. Five types of ocean renewable energy were reviewed including tidal barrage, tidal current energy, wave energy, Ocean Thermal Energy Conversion (OTEC) and salinity gradient power. The comparison of various types of ocean renewable energy has been made to present their recent technologies in electricity generation. Tidal current energy is identified as a preferable option particularly in the Straits of Malacca. © 2013 Elsevier Ltd.

Quteishat A.,Al - Balqa Applied University | Lim C.P.,University of science | Tan K.S.,University of Malaya
IEEE Transactions on Systems, Man, and Cybernetics Part A:Systems and Humans | Year: 2010

In this paper, a two-stage pattern classification and rule extraction system is proposed. The first stage consists of a modified fuzzy minmax (FMM) neural-network-based pattern classifier, while the second stage consists of a genetic-algorithm (GA)-based rule extractor. Fuzzy ifthen rules are extracted from the modified FMM classifier, and a don't care approach is adopted by the GA rule extractor to minimize the number of features in the extracted rules. Five benchmark problems and a real medical diagnosis task are used to empirically evaluate the effectiveness of the proposed FMM-GA system. The results are analyzed and compared with other published results. In addition, the bootstrap hypothesis analysis is conducted to quantify the results of the medical diagnosis task statistically. The outcomes reveal the efficacy of FMM-GA in extracting a set of compact and yet easily comprehensible rules while maintaining a high classification performance for tackling pattern classification tasks. © 2006 IEEE.

The Carnot cycle and its deduction of maximum conversion efficiency of heat inputted and outputted isothermally at different temperatures necessitated the construction of isothermal and adiabatic pathways within the cycle that were mechanically "reversible", leading eventually to the Kelvin-Clausius development of the entropy function S with differential dS = dq/T such that ∮C dS = 0 where the heat absorption occurs at the isothermal paths of the elementary Carnot cycle. Another required condition is that the heat transfer processes take place infinitely slowly and "reversibly", implying that rates of transfer are not explicitly featured in the theory. The definition of 'heat' as that form of energy that is transferred as a result of a temperature difference suggests that the local mode of transfer of "heat" in the isothermal segments of the pathway implies a Fourier-like heat conduction mechanism which is apparently irreversible, leading to an increase in entropy of the combined reservoirs at either end of the conducting material, and which is deemed reversible mechanically. These paradoxes are circumvented here by first clarifying the terms used before modeling heat transfer as a thermodynamically reversible but mechanically irreversible process and applied to a one dimensional atomic lattice chain of interacting particles subjected to a temperature difference exemplifying Fourier heat conduction. The basis of a "recoverable trajectory" i.e. that which follows a zero entropy trajectory is identified. The Second Law is strictly maintained in this development. A corollary to this zero entropy trajectory is the generalization of the Zeroth law for steady state non-equilibrium systems with varying temperature, and thus to a statement about "equilibrium" in steady state non-thermostatic conditions. An energy transfer rate term is explicitly identified for each particle and agrees quantitatively (and independently) with the rate of heat absorbed at the reservoirs held at different temperatures and located at the two ends of the lattice chain in MD simulations, where all energy terms in the simulation refer to a single particle interacting with its neighbors. These results validate the theoretical model and provides the necessary boundary conditions (for instance with regard to temperature differentials and force fields) that thermodynamical variables must comply with to satisfy the conditions for a recoverable trajectory, and thus determines the solution of the differential and integral equations that are used to model these processes. These developments and results, if fully pursued would imply that not only can the Carnot cycle be viewed as describing a local process of energy-work conversion by a single interacting particle which feature rates of energy transfer and conversion not possible in the classical Carnot development, but that even irreversible local processes might be brought within the scope of this cycle, implying a unified treatment of thermodynamically (i) irreversible (ii) reversible (iii) isothermal and (iv) adiabatic processes by conflating the classically distinct concept of work and heat energy into a single particle interactional process. A resolution to the fundamental and long-standing conjecture of Benofy and Quay concerning the Fourier principle is one consequence of the analysis. © 2016 Christopher Gunaseelan Jesudason. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Wong K.T.,University of Malaya
Acta Neuropathologica | Year: 2010

In the last few decades, there is an increasing emergence and re-emergence of viruses, such as West Nile virus, Enterovirus 71 and henipaviruses that cause epidemic viral encephalitis and other central nervous system (CNS) manifestations. The mortality and morbidity associated with these outbreaks are significant and frequently severe. While aspects of epidemiology, basic virology, etc., may be known, the pathology and pathogenesis are often less so, partly due to a lack of interest among pathologists or because many of these infections are considered "third world" diseases. In the study of epidemic viral encephalitis, the pathologist's role in unravelling the pathology and pathogenesis is critical. The novel henipavirus infection is a good example. The newly created genus Henipavirus within the family Paramyxoviridae consists of two viruses, viz., Hendra virus and Nipah virus. These two viruses emerged in Australia and Asia, respectively, to cause severe encephalitides in humans and animals. Studies show that the pathological features of the acute encephalitis caused by henipaviruses are similar and a unique dual pathogenetic mechanism of vasculitis-induced microinfarction and parenchymal cell infection in the CNS (mainly neurons) and other organs causes severe tissue damage. Both viruses can cause relapsing encephalitis months and years after the acute infection due to a true recurrent infection as evidenced by the presence of virus in infected cells. Future emerging viral encephalitides will no doubt continue to pose considerable challenges to the neuropathologist, and as the West Nile virus outbreak demonstrates, even economically advanced nations are not spared. © 2010 Springer-Verlag.

Caracelli I.,Federal University of Sao Carlos | Haiduc I.,Babes - Bolyai University | Zukerman-Schpector J.,Federal University of Sao Carlos | Tiekink E.R.T.,University of Malaya
Coordination Chemistry Reviews | Year: 2013

A bibliographic review of the crystallographic literature reveals that Sb(lone pair), Bi(lone pair)...π(arene) interactions, where the lone pair of electrons is projected towards the centre of the arene ring, exist in the crystal structures of antimony(. III) and bismuth(. III) compounds and that, when operating in isolation of other supramolecular motifs, can stabilise clearly defined zero-, one- and two-supramolecular aggregates. Comparisons of closely related structures reveal systematic trends in the distance between the antimony(. III) and bismuth(. III) centre and the ring centroid of the interacting arene ring that are correlated with the Lewis acidity of the metal centre or the electronegativity of metal- or arene-bound substituents. © 2013 Elsevier B.V.

Poznanski R.R.,University of Malaya
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2010

An assumption commonly used in cable theory is revised by taking into account electrical amplification due to intracellular capacitive effects in passive dendritic cables. A generalized cable equation for a cylindrical volume representation of a dendritic segment is derived from Maxwell's equations under assumptions: (i) the electric-field polarization is restricted longitudinally along the cable length; (ii) extracellular isopotentiality; (iii) quasielectrostatic conditions; and (iv) homogeneous medium with constant conductivity and permittivity. The generalized cable equation is identical to Barenblatt's equation arising in the theory of infiltration in fissured strata with a known analytical solution expressed in terms of a definite integral involving a modified Bessel function and the solution to a linear one-dimensional classical cable equation. Its solution is used to determine the impact of thermal noise on voltage attenuation with distance at any particular time. A regular perturbation expansion for the membrane potential about the linear one-dimensional classical cable equation solution is derived in terms of a Green's function in order to describe the dynamics of free charge within the Debye layer of endogenous structures in passive dendritic cables. The asymptotic value of the first perturbative term is explicitly evaluated for small values of time to predict how the slowly fluctuating (in submillisecond range) electric field attributed to intracellular capacitive effects alters the amplitude of the membrane potential. It was found that capacitive effects are almost negligible for cables with electrotonic lengths L>0.5, contributes up to 10% of the signal for cables with electrotonic lengths in the range between 0.25

Mohammed Y.S.,University of Technology Malaysia | Mokhtar A.S.,University of Technology Malaysia | Bashir N.,University of Technology Malaysia | Saidur R.,University of Malaya
Renewable and Sustainable Energy Reviews | Year: 2013

Efforts to improve the quality of life in rural areas rely upon the provision of electrical energy services. Globally, the focus is on identifying and maintaining sustainable and environmentally friendly energy resources, by means of the clean development mechanism (CDM). Supplying electricity by extending the grid to rural domains is, in most cases, economically unproductive, taking into account other related factors that pertain, especially in developing countries. Furthermore, an unfolding energy crisis in the sub-Saharan Africa (SSA) region intensifies the need for decentralized bioenergy applications using modern conversion techniques. Biomass energy produced in rural areas provides a sustainable alternative to grid electricity. This paper presents an overview of the potential of agricultural biomass-based resources for decentralized energy in rural areas of Ghana. It emphasizes the strategic importance of biomass energy, especially in areas where it is economically attractive because of the ready availability of resources. Assimilation of past and current research reported in the literature on biomass resources and bioenergy technologies in the country underpins this study. A more detailed evaluation of agricultural biomass-based potential was carried out and 2010 was chosen as the base period for the assessment. The result suggests that Ghana has a suitable potential of bioenergy resources and this holds considerable promise for future energy delivery in the country. The paper concludes with discussion of various promising decentralized bioenergy technologies for the exploitation of resources in Ghana. © 2012 Elsevier Ltd.

Yau Y.H.,University of Malaya | Hasbi S.,National University of Malaysia
Renewable and Sustainable Energy Reviews | Year: 2013

Climate observations in recent years indicate that the effects of climate change events are apparently having an increasing impact on society. These impacts will likely also affect the building sector. Numerous studies have been conducted to assess future building energy consumption rates. However, these studies often do not take into account climatic variability and consumer reactions towards a temperature shift. A literature review on climate change impacts for commercial buildings and their technical services in the tropics was carried out. This review focuses on the buildings' contributions towards climate change as well as climate change impacts on building structures, changing patterns of energy use and peak demands, building heating and cooling requirements, thermal comfort and emissions impacts. In general, buildings in regions with a predicted increase in temperature will need more cooling and less heating loads. Thus, building energy consumption and carbon emissions are projected to rise during its operational phase. In addition, the erratic weather trends will also affect the building efficiency and sustainability, indoor air quality and thermal comfort. Even though the existing literature on this issue has increased substantially in recent years, there is still a need for further research in tropical climates as the climate change impacts vary with the different seasons, periods and regions. © 2012 Elsevier Ltd. All rights reserved.

Panwar N.L.,Maharana Pratap University of Agriculture and Technology | Kothari R.,Babasaheb Bhimrao Ambedkar University | Tyagi V.V.,University of Malaya
Renewable and Sustainable Energy Reviews | Year: 2012

Biomass is indirect source of solar energy and it is renewable in nature. It is one of the most important energy source in near future because of its extensive spread availability and promising potential to reduce global warming. Thermo chemical conversion of biomass yield variety of solid, liquid and gaseous fuels and have equal importance both at industrial and ecological point of views. Present review gives holistic view of various thermo-chemical conversion route of biomass. Gasification technology, pyrolysis options and scope of potential by product from there routes like hydrogen and charcoal production comprehensively reviewed with present context. © 2012 Elsevier Ltd. All rights reserved.

Tang C.F.,University of Malaya | Abosedra S.,Lebanese American University
Energy Policy | Year: 2014

Using panel data of 24 countries in the Middle East and North African (MENA) region from 2001 to 2009, the purpose of this study is to examine the impacts of tourism, energy consumption and political instability on economic growth within the neoclassical growth framework. To address the objective of this study, we utilise both the static panel data approach as well as the dynamic generalised method of moments (GMM) estimator to examine the impact of candidate variables. Our results show that energy consumption and tourism significantly contribute to the economic growth of countries in the MENA region. Hence, our study lends some support to the existence of the tourism-led growth and energy-led growth hypotheses in the region. In line with our expectation, our estimation results also reveal that political instability impedes the process of economic growth and development in the MENA region. Therefore, macroeconomic policies to promote expansion in tourism and energy consumption will directly stimulate economic growth. Additionally, efforts to help the region overcome its history of political instability would attract more international tourist arrivals and further invigorate economic growth. © 2014 Elsevier Ltd.

Xi Z.,Harvard University | Wang Y.,Fudan University | Bradley R.K.,Fred Hutchinson Cancer Research Center | Sugumaran M.,University of Malaya | And 3 more authors.
PLoS Genetics | Year: 2013

Recent studies have suggested that plant genomes have undergone potentially rampant horizontal gene transfer (HGT), especially in the mitochondrial genome. Parasitic plants have provided the strongest evidence of HGT, which appears to be facilitated by the intimate physical association between the parasites and their hosts. A recent phylogenomic study demonstrated that in the holoparasite Rafflesia cantleyi (Rafflesiaceae), whose close relatives possess the world's largest flowers, about 2.1% of nuclear gene transcripts were likely acquired from its obligate host. Here, we used next-generation sequencing to obtain the 38 protein-coding and ribosomal RNA genes common to the mitochondrial genomes of angiosperms from R. cantleyi and five additional species, including two of its closest relatives and two host species. Strikingly, our phylogenetic analyses conservatively indicate that 24%-41% of these gene sequences show evidence of HGT in Rafflesiaceae, depending on the species. Most of these transgenic sequences possess intact reading frames and are actively transcribed, indicating that they are potentially functional. Additionally, some of these transgenes maintain synteny with their donor and recipient lineages, suggesting that native genes have likely been displaced via homologous recombination. Our study is the first to comprehensively assess the magnitude of HGT in plants involving a genome (i.e., mitochondria) and a species interaction (i.e., parasitism) where it has been hypothesized to be potentially rampant. Our results establish for the first time that, although the magnitude of HGT involving nuclear genes is appreciable in these parasitic plants, HGT involving mitochondrial genes is substantially higher. This may represent a more general pattern for other parasitic plant clades and perhaps more broadly for angiosperms. © 2013 Xi et al.

Ramesh S.,University of Malaya | Lu S.-C.,University Tunku Abdul Rahman
Journal of Molecular Structure | Year: 2011

The X-ray Diffraction (XRD), Horizontal Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (HATR-FTIR) and Differential Scanning Calorimetry (DSC) have been employed to study the correlation between the concentration of lithium trifluoromethanesulfonate (LiTf) salt with the conversion of crystalline to amorphous nature in poly(vinylidene fluoride-co-hexafluoropropylene) [P(VdF-HFP)]. Results obtained from selected samples with low, intermediate and high concentrations of LiTf salt incorporated in P(VdF-HFP) suggest that the LiTf salt effectively reduces the degree of crystallinity in P(VdF-HFP)-based solid polymer electrolytes. The addition of LiTf to P(VdF-HFP) creates an interaction between cations and the fluorine atom of the copolymer. All the results corroborate each other and supported by impedance spectroscopy and photoluminescence studies (PL). This signifies that LiTf is well dissociated to complex with P(VdF-HFP). It effectively disrupts the crystalline domain and gives rise to new P(VdF-HFP)/LiTf amorphous phase. © 2011 Elsevier B.V. All rights reserved.

Laurance W.F.,James Cook University | Clements G.R.,James Cook University | Clements G.R.,University of Malaya | Sloan S.,James Cook University | And 9 more authors.
Nature | Year: 2014

The number and extent of roads will expand dramatically this century. Globally, at least 25 million kilometres of new roads are anticipated by 2050; a 60% increase in the total length of roads over that in 2010. Nine-tenths of all road construction is expected to occur in developing nations, including many regions that sustain exceptional biodiversity and vital ecosystem services. Roads penetrating into wilderness or frontier areas are a major proximate driver of habitat loss and fragmentation, wildfires, overhunting and other environmental degradation, often with irreversible impacts on ecosystems. Unfortunately, much road proliferation is chaotic or poorly planned, and the rate of expansion is so great that it often overwhelms the capacity of environmental planners and managers. Here we present a global scheme for prioritizing road building. This large-scale zoning plan seeks to limit the environmental costs of road expansion while maximizing its benefits for human development, by helping to increase agricultural production, which is an urgent priority given that global food demand could double by mid-century. Our analysis identifies areas with high environmental values where future road building should be avoided if possible, areas where strategic road improvements could promote agricultural development with relatively modest environmental costs, and 'conflict areas' where road building could have sizeable benefits for agriculture but with serious environmental damage. Our plan provides a template for proactively zoning and prioritizing roads during the most explosive era of road expansion in human history. ©2014 Macmillan Publishers Limited. All rights reserved.

Ghanbarisabagh M.,University of Malaya
IEEE Journal of Quantum Electronics | Year: 2013

In order to reduce the cyclic prefix (CP) length in direct-detection optical orthogonal frequency-division multiplexing (O-OFDM) over 1200 km of single-mode fiber (SMF), a low complexity decision feedback time-domain equalizer (LCDF-TEQ) is proposed. As a result, the residual inter symbol interference (ISI) and inter carrier interference (ICI) caused by both the group velocity dispersion (GVD) and the CP length being shorter than the channel impulse response (CIR) will be cancelled. The recursive calculation of channel matrix inverse reduces the computational complexity. Simulation results show that the performance of LCDF-TEQ is close to decision feedback time-domain equalizer (DF-TEQ) with a much lower complexity. © 1965-2012 IEEE.

Buzayan M.M.,University of Malaya
Prosthetics and Orthotics International | Year: 2014

Background and aim: Mid-facial defect is one of the most disfiguring and impairing defects. A design of prosthesis that is aesthetic and stable can be precious to a patient who has lost part of his face due to surgical excision. Prosthesis can restore the patients' self-esteem and confidence, which affects the patients and their life style. The aim of this case report is to describe a technique of mid-facial silicone prosthesis fabrication. Technique: To provide an aesthetic and stable facial prosthesis, the extra-oral prosthesis was fabricated using silicone material, while the intra-oral defect was restored with obturator prosthesis, and then both prostheses were connected and attached to each other using magnets. Discussion: This clinical report describes the rehabilitation of a large mid-facial defect with a two-piece prosthesis. The silicone facial prosthesis was made hollow and lighter by using an acrylic framework. Two acrylic channels were included within the facial prosthesis to provide the patient with clean and patent airways. © The International Society for Prosthetics and Orthotics 2013.

Balakrishnan V.,University of Malaya
Universal Access in the Information Society | Year: 2016

This study investigated the effects of students’ learning styles on intention to use a social media-enabled tool, entitled Book2U. The focus was on three learning styles, that is, collaborative, independent and participative. Book2U was developed using the Push–Pull–Mooring theory, whilst the questionnaire used for data collection was based on five factors: Academic Reasons, Social Networking, Convenience, Self-efficacy and Ease of Use. Multi-group path modelling was administered on each group of learning styles. Social Networking, Self-efficacy and Convenience were found to have significant direct effects on intention to use Book2U for learning, regardless of the learning styles. No significant differences were observed for Convenience between the groups; however, independent learners emphasized more on Social Networking and Self-efficacy than the rest of the groups. Academic Reasons were found to be significant only among the independent learners, whilst Ease of Use had insignificant impact on intention to use Book2U across all the groups. The findings show that varying learning styles have differing effects in using Book2U for learning, suggesting the need for tools or platforms that cater to diverse groups of students. Understanding the different driving factors of such tools for students with different learning styles will also be beneficial for educators to effectively use any social media tools to assist students in their academic endeavours. © 2016 Springer-Verlag Berlin Heidelberg

Kothari R.,Babasaheb Bhimrao Ambedkar University | Singh D.P.,Babasaheb Bhimrao Ambedkar University | Tyagi V.V.,University of Malaya | Tyagi S.K.,Sardar Swaran Singh National Institute of Renewable Energy
Renewable and Sustainable Energy Reviews | Year: 2012

Hydrogen generation from wastewater is one of the promising approaches through biological route. So, exploitation of wastewater as substrate for hydrogen production with concurrent wastewater treatment is an attractive and effective way of tapping clean energy from renewable resources in a sustainable approach. In this direction, considerable interest is observed on various biological routes of hydrogen production using bio-photolysis, photo fermentation and heterotrophic dark fermentation process or by a combination of these processes. Therefore, in this communication, utilizing industrial wastewater as primary substrate for dark fermentation process is reviewed and different parametric aspects associated with this sustainable approach for better energy production is discussed. The industrial wastewaters that could be the source for bio hydrogen generation, such as rice slurry wastewater, food and domestic wastewaters, citric acid wastewater and paper mill wastewater, are also discussed in this article. © 2012 Elsevier Ltd. All rights reserved.

Goh K.,University of Malaya
Journal of Gastroenterology and Hepatology (Australia) | Year: 2011

Gastroesophageal reflux disease (GERD), previously uncommon in Asia, has now become an important disease in the region. Although much variability exists between studies, most endoscopy-based studies show a prevalence of erosive esophagitis of more than 10%. Symptom-based studies also show a prevalence of 6-10%. Two longitudinal follow-up studies on GERD symptoms have shown an increase with time, and several endoscopy-based time trend studies have also shown a significant increase in erosive reflux esophagitis. Studies on Barrett's esophagus have been confounded by the description of short (SSBE) and long segment (LSBE) Barrett's esophagus. Great variation in prevalence rates has been reported. SSBE vary from 0.1% to more than 20% while LSBE vary from 1-2%. Of the putative causative factors, obesity has been the most important. Many studies have linked GERD-esophagitis as well as occurrence of reflux symptoms with an increase in body mass index (BMI), obesity, especially visceral or central obesity, and metabolic syndrome. A decline in Helicobacter pylori infection with growing affluence in Asia has been broadly thought to result in healthier stomachs and a higher gastric acid output resulting in reflux disease. However, variable results have been obtained from association and H. pylori eradication studies. © 2011 Journal of Gastroenterology and Hepatology Foundation and Blackwell Publishing Asia Pty Ltd.

Jesudason C.G.,University of Malaya
Journal of Mathematical Chemistry | Year: 2011

The primary emphasis of this work on kinetics is to illustrate the a posteriori approach to applied nonlinear analysis, where focus on data may also lead to novel outcomes, as may also be the case with the current a priori tendencies of applied analysis, which relies on axioms or constructs concerning the nature of the observable. Here, methods for the determination of chemical rate constants are developed and discussed utilizing nonlinear analysis which does not require exact knowledge of initial reactant concentrations. These methods are compared with those derived from standard methodology for known chemical reactions studied by eminent kineticists and in one case with a reaction whose initial reactant concentration was in doubt. These gradient methods are shown to be consistent with the standard methods on average, and could readily serve as alternatives for standard conditions and can be used for studies where there are limits or unknowns in the initial conditions, such as in the burgeoning fields of astrophysics and astrochemistry, forensics, archeology and biology where the standard methods are not applicable. All four reactions studied exhibited semi-sinusoidal-like change with reactant concentration change which standard integral methods have not highlighted, and which seems to constitute the observation of a new effect. Reasons based on two mechanisms are given for this observation, and experiments are suggested that can discriminate between these two factors. Although first and second order reactions were investigated here, the method applies to arbitrary fractional orders by polynomial expansion of the rate decay curves where closed form integrated expressions do not exist at present. Integral methods for the above will be investigated next. © 2011 Springer Science+Business Media, LLC.

Salleh N.,University of Malaya
The Scientific World Journal | Year: 2014

Prostaglandins (PGs), derivatives of arachidonic acid, play an indispensable role in embryo implantation. PGs have been reported to participate in the increase in vascular permeability, stromal decidualization, blastocyst growth and development, leukocyte recruitment, embryo transport, trophoblast invasion, and extracellular matrix remodeling during implantation. Deranged PGs syntheses and actions will result in implantation failure. This review summarizes up-to-date literatures on the role of PGs in blastocyst implantation which could provide a broad perspective to guide further research in this field. © 2014 Naguib Salleh.

Han N.C.,Universiti Malaysia Sabah | Muniandy S.V.,University of Malaya | Dayou J.,Universiti Malaysia Sabah
Applied Acoustics | Year: 2011

A new hybrid method for automated frog sound identification, using spectral centroid, Shannon entropy and Rényi entropy is proposed. The advantage of using entropy based information theoretic approach for analyzing complexity of bioacoustics signals in animal vocalization is discussed. Sound samples from nine species of Microhylidae frogs are first segmented into syllables. Fourier spectral centroid, Shannon entropy and Rényi entropy of the syllables are then determined. Finally, nonparametric k-th nearest neighbour (k-NN) classifier is used to recognize the frog species based on these three extracted features. Result shows that the k-NN classifier based on these selected features is capable to identify the species of the frogs with an average accuracy of 98%. It is found that the accuracy reduces significantly only when the noise levels higher than -20 dB. © 2011 Elsevier Ltd. All rights reserved.

Irfan M.F.,University of Malaya | Usman M.R.,University of Punjab | Kusakabe K.,Fukuoka Womens University
Energy | Year: 2011

Numerous coal gasification studies have been found in the literature those employed various kinds of gasifying agents such as steam and carbon dioxide. These studies are featured with wide variations in the parametric conditions and the usage of equipments. Steam is frequently employed as a gasifying agent, however, in several studies carbon dioxide has also been used as a gasifying agent either pure or in combination with other gasifying agents (H2O, O2, CO, H2). This paper is a brief review of the coal gasification with CO2 as a diluent. Different factors were studied over the coal gasification with CO2 such as coal rank, pressure, temperature, gas composition, catalyst and the minerals present inside the coal, heating rate, particle size, and diverse reactor types. It also deals with the application of the gas-solid models developed in the literature and the combustion and gasification mechanisms for O2/CO2 streams. Moreover, it reviews the kinetics and the reaction rate equations (Arrhenius and Langmuir-Hinshelwood types) for coal-char gasification both in the reaction kinetic control region (low temperature) and the diffusion control region (high temperature) and at both low and high pressures. © 2010 Elsevier Ltd.

Abbas H.F.,Sunway University | Baker I.F.,University of Malaya
International Journal of Hydrogen Energy | Year: 2011

The thermocatalytic decomposition of methane over activated carbon (AC) is proposed as a potential alternative for the production of hydrogen. The experiments were divided into two parts; the first part was conducted using thermogravimetric analyzer (TGA) while the second part was conducted in a bench-scale unit. For the first part, the research objective is to study the main and interaction effects of decomposition temperature (800-950 °C) and methane partial pressure (0.03-0.63 atm) on the initial specific rate of carbon formation by using statistical method. The experiments were carried out as a general full factorial design consisting of 20 experiments. Quadratic model was developed for initial specific rate of carbon formation in term of temperature and methane partial pressure using response surface methodology. The model's results show that not only the effects of the main parameters are important, but also the interaction effects between them are significant. For the second part, the main effects of decomposition temperature (775-850 °C) and AC weight (20-120 g) on the initial rate of methane decomposition by using the analysis of variance (ANOVA) were investigated. The results showed that AC weight has higher mean effects than decomposition temperature on the initial rate of methane decomposition. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Hoskin A.W.,University of Texas of the Permian Basin | Ellis L.,University of Malaya
Criminology | Year: 2015

Evolutionary neuroandrogenic (ENA) theory asserts that criminality is a crude form of competitive behavior over resources, status, and mating opportunities. Theoretically, males have been selected for resource acquisitiveness as a result of female preferences for mates who are successful at resource provisioning. ENA theory also asserts that brain exposure to both prenatal and postpubertal androgens (particularly testosterone) promotes all forms of competitiveness, including those that victimize others. The present study was undertaken to test ENA theory by correlating 14 self-reported measures of offending with a biomarker for fetal testosterone exposure based on the ratio of the 2nd and 4th digits of the right hand (r2D:4D), in a nonrepresentative sample of 445. Both Spearman correlations and negative binomial regressions produced results that largely supported the hypothesized connection between offending and high prenatal androgen exposure, even when findings were analyzed separately by sex. Also, offending was significantly associated with r2D:4D for both males and females. Overall, this study supports the view that exposing the brain to high levels of testosterone and other androgens prenatally elevates the probability of offending later in life. © 2014 American Society of Criminology.

Rajagopal K.K.,University of Malaya
Physica A: Statistical Mechanics and its Applications | Year: 2015

We study the dynamics of an atomic condensate loaded in two symmetric traps where one of the trap is coupled to a reservoir. Analytical solution of the population dynamics is given for the non-interacting two-mode Bose-Einstein condensate system in the Markovian limit. In our model dissipation is induced by the reservoir fluctuation in agreement with the Fluctuation-Dissipation theorem. For the interacting two-mode case however, we resort to numerical calculation to study the effect of damping on the population evolution. We have shown that dissipation acting concurrently with repulsion interaction drives the BEC self trapping state back to the quantum tunnelling state for the zero-temperature case. For the finite temperature case however much surprising dynamics were observed as the tunnelling between the traps is suppressed when the temperature of the system is increased. © 2015 Elsevier B.V. All rights reserved.

Background: Malaysia's organ and tissue donation rates are among the lowest in the world. The study aims to explore the knowledge, attitudes, practices and behaviors regarding deceased organ donation and transplantation in the diverse ethnic communities in the state of Selangor, Malaysia. Methods: A cross-sectional, population-based, computer-assisted telephone interview exploring multi-ethnic participants' knowledge, attitudes, practices and behavioral on deceased organ donation and transplantation was conducted from February to April 2009. Results: Although only 5.5% of the total participants (N=1174) reported that they have registered to be organ donor, a further 35.2% of those who have not register for organ donation indicated willingness to donate their own. Significant socio-demographic disparities with respect to knowledge and attitudes scores were observed. In particular, Malays (20.7%) indicated lower willingness to donate organs compared to the Chinese (36.6%) and Indians (51.4%) (p<0.001). In multivariate logistic regression analysis, willingness to donate one's own organ was associated with knowledge score (odds ratio [OR]=1.17, 95% confidence interval [CI]=1.13-1.22), attitude score (OR=1.17, 95% CI=1.05-1.31), secondary school education (OR=1.46, 95% CI=1.05-2.02), and Malay ethnicity (OR=0.18, 95% CI=0.03-0.94). Conclusion: Findings assist organ donation and transplantation organizations to reach out the diverse socio-demographic and ethnic communities with cultural-specific information about organ donation. © 2010 John Wiley & Sons A/S.

Tarlochan F.,University of Tenaga Nasional | Ramesh S.,University of Malaya
Composite Structures | Year: 2012

Polymer composite sandwich structures are promising candidate structures for reducing vehicle mass, thereby improving the fuel economics. Nonetheless, to fully explore this material as the primary structure and energy absorber in vehicles, it is important to understand the energy absorption capability of this material. Hence, in the present work, comprehensive experimental investigation on the response of composite sandwich structures to quasi-static compression has been carried out. The crashworthiness parameters, namely the peak force, absorbed crash energy, specific absorbed energy, average crushing force and crush force efficiency of various types of composite sandwich structures were investigated in a series of edgewise axial compression tests. The tested composite sandwich specimens were fabricated from glass and carbon fiber with epoxy resin. Four distinct modes of failure were observed and recorded. The primary mode of failure observed was progressive crushing with high energy absorption capability. The optimized design in this study had a specific energy absorption capability of 47.1. kJ/kg with a good crush force efficiency of 0.77, higher than conventional metals. © 2011 Elsevier Ltd.

Naganathan S.,University of Tenaga Nasional | Razak H.A.,University of Malaya | Hamid S.N.A.,Kualiti Alam Sdn Bhd
Materials and Design | Year: 2012

Industrial waste incineration bottom ash and quarry dust are waste materials which, if reused, will contribute to sustainability. One of the potential uses of these materials in bulk quantities is in controlled low-strength material (CLSM). This paper evaluates the properties of controlled low-strength material (CLSM) made using industrial waste incineration bottom ash and quarry dust. Various mix proportions of CLSM containing bottom ash and quarry dust were developed and the properties evaluated. Tests were performed on the CLSM in fresh and hardened states involving flowability, stability, setting time, segregation resistance, California bearing ratio (CBR), and corrosivity and the results discussed. Results indicated that the setting time of the CLSM mixtures tested ranged from 3.7 to 8h, the fresh density from 1539 to 2100kg/m3, strength values from 0.22 to 11.42MPa, mixtures were stable and no corrosivity. It is shown that addition of quarry dust enhanced the performance of CLSM made using bottom ash with regard to stability, strength, and CBR and hence both the industrial waste incineration bottom ash and quarry dust are potential materials for use in CLSM. © 2011 Elsevier Ltd.

Ramesh S.,University of Malaya | Lu S.-C.,Catholic University of Leuven
Journal of Molecular Liquids | Year: 2013

In the present work, we report a simple solid polymer electrolyte (SPE) system that is solely based on poly(vinylidene fluoride-co-hexafluoropropylene) [P(VdF-HFP)] and lithium trifluoromethanesulfonate (LiTf). The SPEs produced exhibit high ionic conductivity of ∼ 10- 4 S cm- 1 at ambient temperature when 40 wt.% of LiTf is incorporated. There is an anomaly when moderate amount of LiTf is added into the polymer. This can be related to formation of neutral ion pairs, and substantiated by calculation of activation energy and scanning electron micrographs. TGA thermograms also show that all the samples tested are thermally stable up to 400 °C, even with the incorporation of LiTf. The highest ionic conducting sample achieves highest onset temperature of decomposition. © 2012 Elsevier B.V. All rights reserved.

Ahmad M.Y.,University of Technology, Sydney | Ahmad M.Y.,University of Malaya | Mohan A.S.,University of Technology, Sydney
IEEE Transactions on Industrial Electronics | Year: 2014

We propose a novel method of positioning using a high-frequency radio-frequency identification (HF RFID) system for navigating autonomous vehicles when a sparse grid of floor tags is employed. For this, we propose a novel triangular multiloop-bridge reader antenna which generates an error signal in the form of bridge potential that is a function of the tags' location. The proposed positioning algorithm combines the information from the reader database with the error signals generated by the bridge loop and couples them with any available data from the wheel encoders of an autonomously moving object to deduce its position and orientation. The accuracy and efficacy of the proposed algorithm are evaluated using both simulations and experiments using an autonomous wheelchair. The results indicate that the proposed method offers a significant improvement over existing HF-RFID-based positioning methods for larger floor-tag-grid separation. © 1982-2012 IEEE.

Boey C.C.M.,University of Malaya
Journal of Health and Translational Medicine | Year: 2010

In the last three centuries, medicine has focused predominantly on the physical body as the source of disease, placing very little importance on the mind. However, the significance of mind-body interactions in medicine is now increasingly being recognised. True health must include both the physical body and the mind. This article traces our concepts of the relationship between mind and body since primitive times and explores its relevance to the maintenance of health.

Ibrahim R.W.,University of Malaya
Entropy | Year: 2013

In this work, we introduce a generalization of the differential polynomial neural network utilizing fractional calculus. Fractional calculus is taken in the sense of the Caputo differential operator. It approximates a multi-parametric function with particular polynomials characterizing its functional output as a generalization of input patterns. This method can be employed on data to describe modelling of complex systems. Furthermore, the total information is calculated by using the fractional Poisson process. ©2013 by the authors; licensee MDPI, Basel, Switzerland.

Tan H.-J.,Sunway Medical Center | Goh K.-L.,University of Malaya
Journal of Digestive Diseases | Year: 2012

Helicobacter pylori (H. pylori) infection is reported to be associated with many extragastrointestinal manifestations, such as hematological diseases [idiopathic thrombocytopenic purpura (ITP) and unexplained iron deficiency anemia (IDA)], cardiovascular diseases (ischemic heart diseases), neurological disorders (stroke, Parkinson's disease, Alzheimer's disease), obesity and skin disorders. Among these, the best evidence so far is in ITP and unexplained IDA, with high-quality studies showing the improvement of IDA and ITP after H. pylori eradication. The evidence of its association with coronary artery disease is weak and many of the results may be erroneous. The role of H. pylori infection in affecting serum leptin and ghrelin levels has attracted a lot of attention recently and available data to date have been conflicting. There have also been many uncontrolled, small sample studies suggesting an association between H. pylori infection and neurological disorders or chronic urticaria. However, more studies are required to clarify such proposed causal links. © 2012 The Authors. Journal of Digestive Diseases © 2012 Chinese Medical Association Shanghai Branch, Chinese Society of Gastroenterology, Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine and Blackwell Publishing Asia Pty Ltd.

Opportunistic observations for cetaceans were conducted during the 2009 Prime Scientific Sailing Expedition, onboard the Royal Malaysian Navy Hydrographic vessel, KD PERANTAU. A total of 21 days was spent conducting observations in the Malaysian waters of the South China, Sulu and Sulawesi Seas. The survey yielded a total of 27 sightings and comprised (in order of frequency) the spinner dolphin (Stenella longirostris), bottlenose dolphin (Tursiops sp.), pantropical spotted dolphin (S. attenuata), unidentified dolphins, and an unidentified species of whale. The depth range for spinner dolphins ranged from shallow continental shelf depths to deep waters beyond the shelf. Similarly, bottlenose dolphins were found both in inshore and offshore waters, and based on external morphology, were likely to be T. aduncus. Despite reported high cetacean diversity in neighbouring countries such as the Philippines and Indonesia, the diversity of cetaceans observed during the expedition was low, perhaps owing to seasonal oceanography. Although opportunistic in nature, the survey provided a rare opportunity to study the diversity and distribution of cetaceans in deeper offshore waters that are otherwise difficult to reach by smaller vessels. The results here emphasise the need for further dedicated cetacean research in the pelagic waters of the South China, Sulu and Sulawesi Seas. This paper also uses data from the opportunistic survey and other records collated by the author to construct an updated checklist of marine mammals in Malaysia as a means of providing the most comprehensive overview of confirmed species records in the country and to further assist future research and conservation plans. © National University of Singapore.

Herat S.,Griffith University | Agamuthu P.,University of Malaya
Waste Management and Research | Year: 2012

Safe management of electronic and electrical waste (e-waste/WEEE) is becoming a major problem for many countries around the world. In particular, developing countries face a number of issues with the generation, transboundary movement and management of e-waste. It is estimated that the world generates around 20-50 million tonnes of e-waste annually, most of it from Asian countries. Improper handling of e-waste can cause harm to the environment and human health because of its toxic components. Several countries around the world are now struggling to deal with this emerging threat. Although the current emphasis is on end-of-life management of e-waste activities, such as reuse, servicing, remanufacturing, recycling and disposal, upstream reduction of e-waste generation through green design and cleaner production is gaining much attention. Environmentally sound management (ESM) of e-waste in developing countries is absent or very limited. Transboundary movement of e-waste is a major issue throughout the region. Dealing with the informal recycling sector is a complex social and environmental issue. There are significant numbers of such challenges faced by these countries in achieving ESM of e-waste. This article aims to present a review of challenges and issues faced by Asian countries in managing their e-waste in a sustainable way. © The Author(s) 2012.

Lee H.V.,University of Malaya | Taufiq-Yap Y.H.,University Putra Malaysia
Process Safety and Environmental Protection | Year: 2015

The focus of this study is to produce biodiesel using non-edible feedstock (Jatropha curcas oil) via heterogeneous base catalyzed transesterification reaction. The solid base catalysts, binary metal oxide (CaO-ZnO and CaO-La2O3) were selected for the transesterification of high acid jatropha oil. Furthermore, the design of experiments was performed using 5-level-4 factor central composite design coupled with response surface methodology (RSM) in order to optimize the transesterification conditions. Four process factors were evaluated: (1) reaction time (1-5 h), (2) methanol/oil molar ratio (15:1-30:1), (3) reaction temperature (40-200 °C) and (4) catalyst loading (1-5 wt.%). Based on the quadratic model generated from RSM, reaction temperature rendered the most significant effect for both CaO-ZnO and CaO-La2O3 catalyzed reactions, followed by catalyst loading and reaction time. Besides, both reaction models showed that interaction between reaction temperature with reaction time and catalyst loading has positively influenced the biodiesel yield. The highest conversion predicted for CaO-ZnO and CaO-La2O3 catalyzed reactions was 97.03% and 96.27%, respectively, with reasonable predictability and sufficient accuracy data (small error: 0.33-0.34%). Furthermore, the physicochemical characteristics of produced biodiesel were tested with compliance to ASTM D7851 and EN 14124. © 2014 The Institution of Chemical Engineers.

De La Rue R.M.,University of Malaya | De La Rue R.M.,University of Glasgow | Seassal C.,Ecole Centrale Lyon
Laser and Photonics Reviews | Year: 2012

This review article is concerned with basic aspects and some selected topics in photonic crystal (PhC) devices. It starts with a significantly historical aspect of basic principles for photonic crystals that it is hoped will help the reader to develop a critical appreciation of the research literature. It continues by describing topics such as PhC beamsplitters, slow-light structures, micro-/nanoresonators, coupled resonator optical waveguides (CROWs) and PhC-based semiconductor lasers. Emphasis is placed on both the conceptual and the practical matters that need to be addressed in order to fulfill the tasks of designing and realizing devices that exploit photonic crystal principles. The review also addresses some of the problems encountered in the fabrication of photonic crystal devices using the planar technologies of integrated photonics, which are those that are most likely to be used in future commercial production. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Teh C.Y.,University of Selangor | Wu T.Y.,University of Selangor | Juan J.C.,University of Malaya
Ecological Engineering | Year: 2014

The present study investigated the use of starch to replace inorganic coagulants for the treatment of agro-industrial wastewater from palm oil mill, namely palm oil mill effluent (POME). Rice starch was found to be the best starch because it yielded similar total suspended solids (TSS) removal as alum, significantly shortened the settling time and produced flocs with higher resistance towards stronger shear force. The use of rice starch alone in room temperature enabled the removal of TSS up to 84.1% using the recommended values of dosage, initial pH, settling time and slow stirring speed at 2. g/L, pH 3, 5. min and 10. rpm, respectively. Higher TSS removal of 88.4% could still be achieved at lower dosage of rice starch (0.55. g/L) only when rice starch was used together with 0.2. g/L of alum during the treatment of POME. To gain further insights on the properties of coagulants and flocs produced from the treatment, characterization methods such as Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) were used. © 2014 Elsevier B.V.

Vanaki S.,University of Malaya | Mohammed H.A.,University of Technology Malaysia
International Communications in Heat and Mass Transfer | Year: 2015

A numerical investigation is performed to study the effects of different rib shapes and turbulent nanofluid flow on the thermal and flow fields through transversely roughened rectangular channels with Reynolds number ranging from 5000 to 20000 and uniform heat flux of 10kW/m2. Considering single-phase approach, the two-dimensional continuity, Navier-Stokes, and energy equations were solved by using the finite volume method (FVM). The optimization was carried out by using various rib shapes (rectangular shape, triangular shape, wedge pointing upstream, and wedge pointing downstream) in two arrangements (in-line and staggered) and three different aspect ratios (w/e=0.5, 2, and 4) to reach the optimal geometry with maximum performance evaluation criterion (PEC). The main aim of this study is to analyze the effects of nanoparticle types (Al2O3, CuO, SiO2, and ZnO), concentration (1-4%), and nanoparticle diameter (30-80nm), on the heat transfer and fluid flow characteristics. Simulation results show that the ribbed channels' performance was greatly influenced by rib shapes and their geometrical parameters. The highest PEC was obtained for the in-line triangular ribs with w/e=4 at Re=5000. It is found that the water-SiO2 shows the highest heat transfer enhancement compared with other tested nanofluids. The Nusselt number through the ribbed channels was enhanced with the increase of the particle volume fraction and Reynolds number, and with the decrease of nanoparticle diameter. © 2015 Elsevier Ltd.

Atiquil Islam A.Y.M.,University of Malaya
International Journal of Technology and Human Interaction | Year: 2014

This project validates the Technology Satisfaction Model (TSM) developed. While Technology Acceptance Model (TAM) developed by Davis (1989) ignored the issue of computer self-efficacy and satisfaction. TSM incorporates both. While TAM is used for measuring the acceptance of technology in general; TSM examines the satisfaction on wireless internet usage with a particular focus to the students studying in Higher Education. To develop and validate the TSM, data gained through a survey conducted with 285 students studying in five faculties of a comprehensive public university in Malaysia. Quota sampling technique was used. Instrument reliability and validity were performed by Rasch analysis using Winsteps version 3.49. The results of the study were analyzed by Structural Equation Modeling (SEM) using AMOS version 18.0. The findings showed that perceived ease of use and perceived usefulness had a statistically significant positive direct influence on satisfaction. Subsequently, computer self-efficacy discovered a significant positive direct influence on perceived usefulness and perceived ease of use. Moreover, the results also demonstrated that computer self-efficacy had a significant indirect influence on satisfaction mediated by perceived usefulness. Eventually, computer self-efficacy also revealed a statistically significant indirect influence on satisfaction mediated by perceived ease of use of wireless internet. Copyright © 2014, IGI Global.

Jones E.B.G.,University of Malaya | Pang K.-L.,National Taiwan Ocean University
Biodiversity and Conservation | Year: 2012

This paper reports on the distribution of fungal communities in aquatic habitats in tropical regions and highlights differences in the taxa observed in freshwater and marine habitats. Ascomycetes are dominant on substrata in marine environments, with few basidiomycetes and discomycetes. Equally, few freshwater basidiomycetes and discomycetes have been reported from the tropics. In marine habitats, Dothideomycetes dominate on mangrove substrata, and halosphaeriaceous species are most numerous on submerged woody substrata in coastal waters, while yeasts are common in seawater and estuarine habitats. In freshwater, Ingoldian anamorphic fungi are most numerous on decaying leaves, while ascomycetes (Dothideomycetes, Sordariomycetes) are prevalent on submerged/exposed woody substrata. Unique fungi are found in tropical waters and differ from those in temperate locations. © 2011 Springer Science+Business Media B.V.

Hasima N.,University of Houston | Hasima N.,University of Malaya | Aggarwal B.B.,University of Houston
Current Medicinal Chemistry | Year: 2014

Curcumin, a major component of the golden spice turmeric (Curcuma longa), has been linked with the prevention and treatment of a wide variety of cancers through modulation of multiple cell signaling pathways. Since the first report from our laboratory in 1995 that curcumin can inhibit activation of the proinflammatory transcription factor NF-B by inhibiting the 26S proteasomal degradation of IB, an inhibitor of NF-B, this yellow pigment has been shown to inhibit the protease activities of the proteasome. The carbonyl carbons of the curcumin molecule directly interact with the hydroxyl group of the amino-terminal threonine residue of the proteasomal CT-L subunit of 20S proteasome and cellular 26S proteasome. Curcumin is also a potent inhibitor of COP9 signalosome and associated kinases, casein kinase 2 and protein kinase D, all linked to the ubiquitin-proteasomal system (UPS). Curcumin can also directly inhibit ubiquitin isopeptidases, a family of deubiquitinases (DUBs) that salvage ubiquitin for reuse by the 26S proteasome system. The inhibition of this enzyme by curcumin is mediated through ,-unsaturated ketone and two sterically accessible -carbons. Regulation of the UPS pathway by curcumin has been linked to regulation of cancer-linked inflammatory proteins (such as COX-2 and iNOS), transcription factors (NF-B, STAT3, Sp, AP-1, GADD153/CHOP, HIF-1), growth factors (VEGF, HER2), apoptotic proteins (p53, Bcl-2, survivin, DNA topoisomerase II, HDAC2, p300, hTERT) and cell cycle proteins (cyclin D1, cyclin E, cyclin B, p21, p27) associated with the prevention and therapy of cancer. Interestingly, the effect of curcumin on 26S proteasome appears to be dose-dependent, as low doses (1 M) increase proteasome activity whereas high doses (10 M) inhibit the proteasome activity. In this review, we discuss in detail how modulation of these targets by curcumin is linked to prevention and treatment of cancer. © 2014 Bentham Science Publishers.

Kumar A.,University of Malaya
Analog Integrated Circuits and Signal Processing | Year: 2013

A new analog cell, called floating gate split length MOSFET (FGSLM), has been presented. This cell is based on the popular self-cascode structure, and has been found suitable for use in low voltage design applications. The proposed cell has been characterized using 130 nm technology at supply voltage of 1.2 V. Simulation results are presented to demonstrate the utility of the proposed cell in low voltage self cascode structures. © 2012 Springer Science+Business Media New York.

Por L.Y.,University of Malaya
International Arab Journal of Information Technology | Year: 2013

This paper addresses a newly discovered security threat named Frequency of Occurrence Analysis (FOA) attack in searchmetics password authentication scheme. A countermeasure technique that utilises Metaheuristic Randomisation Algorithm (MRA) is proposed to address the FOA attack. The proposed Algorithm is presented and an offline FOA attack simulation tool is developed to verify the effectiveness of the proposed method. In addition, a shoulder surfing testing is conducted to evaluate the effectiveness of the proposed method in terms of mitigating shoulder surfing attack. The experiment results show that MRA is able to prevent FOA and mitigate shoulder surfing attacks. Moreover, the proposed method is able to provide larger password space compare to the benchmarking scheme.

Jenatabadi H.S.,University of Malaya
Contemporary Engineering Sciences | Year: 2014

The purpose of this research article is to give a conceptual model of innovation management in food production industry in east of Asia. The researchers create and propose a conceptual model rooted in past research on innovation management, performance and organization culture (OC). The data for the research were obtained by surveys given to 168 Chinese, Taiwanese and Malaysian companies. Structural equation modeling (SEM) methodology was used in this study. The results of the study show that in food production firms OC and organizational innovation (OI) have positively direct impacts on organizational performance (OP). These results have useful implications for the companies specially those involved in food production which tries to win competitions and also positively respond to the environmental changes through successful applications of innovation. Findings also stress that systems used and applied to stimulate and boost an organizational innovative culture would most probably make the processes of introducing, adopting, and diffusing innovation simpler which would by itself read to higher OP. © 2014 Hashem Salarzadeh Jenatabadi.

Sete E.A.,University of California at Riverside | Eleuch H.,McGill University | Ooi C.H.R.,University of Malaya
Journal of the Optical Society of America B: Optical Physics | Year: 2014

We analyze a scheme to entangle the movable mirrors of two spatially separated nanoresonators via a broadband squeezed light. We show that it is possible to transfer the Einstein-Podolsky-Rosen-type continuous-variable entanglement from the squeezed light to the mechanical motion of the movable mirrors. An optimal entanglement transfer is achieved when the nanoresonators are tuned at resonance with the vibrational frequencies of the movable mirrors and when strong optomechanical coupling is attained. Stationary entanglement of the states of the movable mirrors as strong as that of the input squeezed light can be obtained for sufficiently large optomechanical cooperativity, achievable in currently available optomechanical systems. The scheme can be used to implement long-distance quantum-state transfer provided that the squeezed light interacts with the nanoresonators. © 2014 Optical Society of America.

Lai C.W.,University of Malaya
The Scientific World Journal | Year: 2014

Tungsten trioxide (WO3) possesses a small band gap energy of 2.4-2.8 eV and is responsive to both ultraviolet and visible light irradiation including strong absorption of the solar spectrum and stable physicochemical properties. Thus, controlled growth of one-dimensional (1D) WO3 nanotubular structures with desired length, diameter, and wall thickness has gained significant interest. In the present study, 1D WO3 nanotubes were successfully synthesized via electrochemical anodization of tungsten (W) foil in an electrolyte composed of 1 M of sodium sulphate (Na2SO 4) and ammonium fluoride (NH4F). The influence of NH 4F content on the formation mechanism of anodic WO3 nanotubular structure was investigated in detail. An optimization of fluoride ions played a critical role in controlling the chemical dissolution reaction in the interface of W/WO3. Based on the results obtained, a minimum of 0.7 wt% of NH4F content was required for completing transformation from W foil to WO3 nanotubular structure with an average diameter of 85 nm and length of 250 nm within 15 min of anodization time. In this case, high aspect ratio of WO3 nanotubular structure is preferred because larger active surface area will be provided for better photocatalytic and photoelectrochemical (PEC) reactions. © 2014 Chin Wei Lai.

Piaw Chua Y.,University of Malaya
Computers in Human Behavior | Year: 2012

Computer-based testing (CBT) is a green computing strategies used to reduce paper consumption. However, some scholars have questioned the effectiveness of CBT and suggested for conducting systematic studies on CBT to carefully check its reliability and validity before opting for it. Recently, some studies have evaluated the effectiveness of CBT by comparing it with paper-pencil testing (PPT), and the findings were inconsistent. Besides this, most of these studies have been conducted using quasi or basic experimental designs without identifying testing effects on test takers. The limitation of these design is testing effects might occur when a participant in the control or treatment group is tested at least twice on a same test, and it influences the outcomes of taking a posttest, therefore, the findings might be misinterpreted. This study employed a Solomon four-group experimental design (2 × 3 factorial design) on a group of student teachers (n = 140) to compare CBT and PPT on test performance (test scores), testing time and testing motivation. Results indicated that the CBT mode is more reliable in terms of internal and external validity. The CBT significantly reduced testing time and developed stronger self-efficacy, intrinsic and social testing motivation in the participants. © 2012 Elsevier Ltd. All rights reserved.

Cheah Y.K.,University of Malaya
Malaysian Journal of Nutrition | Year: 2011

Introduction: Given the importance of physical activity to health, this study investigated the socio-demographic determinants of physical activity participation in a sample of adults in Penang. Methods: Through convenience sampling, a total of 398 adults agreed to answer a prepared questionnaire on their socio-demographic background and physical activity participation. The data were analysed using the binary logit model. Frequent physical activity participation is defined as taking part more than 11 times in leisure-time physical activity such as swimming and jogging, each time lasting more than 15 minutes in a typical month, whereas participation that is less than the frequency and time duration specified above is referred to as infrequent physical activity. Results: Age, male, being Chinese, high educational attainment, self-rated excellent health status and presence of family illnesses are positively associated with the likelihood of frequent participation in physical activity. On the contrary, being married, having low income and residing in rural areas are inversely related with the propensity of frequent physical activity participation. Conclusion: The majority in this sample of adults do not participate in physical activity frequently, and the reasons given include lack of health awareness, limited leisure time, budget constraints, and lack of sports amenities.

Zahari Z.,Universiti Sains Malaysia | Ismail R.,Universiti Sains Malaysia | Ismail R.,University of Malaya
Drug Metabolism and Pharmacokinetics | Year: 2014

CYP2D6 polymorphisms show large geographical and interethnic differences. Variations in CYP2D6 activity may impact upon a patient ' s pain level and may contribute to interindividual variations in the response to opioids. This paper reviews the evidence on how CYP2D6 polymorphisms might influence pain sensitivity and clinical response to codeine and tramadol. For example, it is shown that (1) CYP2D6 poor metabolizers (PMs) may be less ef fi cient at synthesizing endogenous morphine compared with other metabolizers. In contrast, ultra-rapid metabolizers (UMs) may be more ef fi cient than other metabolizers at synthesizing endogenous morphine, thus strengthening endogenous pain modulation. Additionally, for codeine and tramadol that are bioactivated by CYP2D6, PMs may undergo no metabolite formation, leading to inadequate analgesia. Conversely, UMs may experience quicker analgesic effects but be prone to higher mu-opioid-related toxicity. The literature suggested the potential usefulness of the determination of CYP2D6 polymorphisms in elucidating serious adverse events and in preventing subsequent inappropriate selection or doses of codeine and tramadol. Notably, even though many studies investigated a possible role of the CYP2D6 polymorphisms on pain sensitivity, pharmacokinetics and pharmacodynamics of these drugs, the results of analgesia and adverse effects are con fl icting. More studies are required to demonstrate genetically determined unresponsiveness and risk of developing serious adverse events for patients with pain and these should involve larger numbers of patients in different population types. Copyright © 2014 by the Japanese Society for the Study of Xenobiotics (JSSX).

Cardiovascular Disease (CVD) is the leading cause of death in both developed and developing countries. While it is relatively easy to identify those who are obviously at high risk and those at the lowest risk for CVD, it is often the large group of individuals with what appears to be modestly abnormal risk factors who contributes most to the burden of CVD. This is where estimation of CVD risk is necessary. Many tools for risk assessment have been devised. All these risk scores have their own inherent advantages and disadvantages. Furthermore, they may also not be directly applicable to a local population. Ideally, each country should have its own risk score that takes into account other factors as well. In the interim, it is worthwhile to be familiar with one of these scores, select one that is most appropriate for your patient and discuss treatment options based on the estimated risk.

Majid S.R.,University of Malaya
Electrochimica Acta | Year: 2015

A simple and easy galvanostatic electrodeposition method is used to synthesise a composite electrode consisting of manganese oxide (Mn3O4), nickel oxide (NiO) and cobalt oxide (Co3O4). The influence of Co3O4 on the morphology of fixed Mn3O4-NiO particles is investigated with a field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM). The nature and elemental of the composite are examined by means of X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX). The electrochemical performances of an Mn3O4-NiO-Co3O4 nanostructure/SS composite electrode are studied by cyclic voltammetry (CV) and galvanostatic charge-discharge (CD) in various electrolytes, i.e. 0.5 M Na2SO4, 0.5 M KOH, 0.5 M Na2SO4/0.04 M K3Fe(CN)6 and 0.5 M KOH/0.04 M K3Fe(CN)6 electrolytes. The composite electrode prepared from 0.15 M Co deposition solution exhibits the optimum specific capacitance of 7404 F g-1 with high energy and power density of 1028 Wh kg-1 and 99 kW kg-1 at 20 A g-1 in mix KOH/0.04 M K3Fe(CN)6 electrolyte, respectively. The results show that the incorporation of K3Fe(CN)6 in KOH electrolyte influences the capacitance of Mn3O4-NiO-Co3O4 composite electrodes. © 2015 Elsevier Ltd. All rights reserved.

Tiekink E.R.T.,University of Malaya
Dalton Transactions | Year: 2012

Despite being disparaged for their malodorous and toxic demeanour, compounds of selenium, a bio-essential element, and tellurium, offer possibilities as therapeutic agents. Herein, their potential use as drugs, for example, as anti-viral, anti-microbial, anti-inflammatory agents, etc., will be surveyed along with a summary of the established biological functions of selenium. The natural biological functions of tellurium remain to be discovered. © 2012 The Royal Society of Chemistry.

Wong S.-M.,University of Malaya | Baba R.,Hospital Kuala Lumpur
International Journal of Dermatology | Year: 2012

Background Vitiligo is a chronic disease and can have significant impairment on patients' quality of life (QoL). Studies have shown that limitations in QoL are similar in magnitude to patients with other chronic skin diseases like psoriasis. The objective of this study was to assess the quality of life (QoL) of patients with vitiligo attending the dermatology clinic of a tertiary hospital in Malaysia. Methods All patients with a clinical diagnosis of vitiligo who were seen at our dermatology clinic and phototherapy daycare center from September 15 to November 20, 2009 were invited to participate. Results A total of 102 patients with vitiligo were included in this survey (56.9% females, 43.1% males; mean age 43.6). The mean DLQI score±SD was 6.40±5.17. The highest mean DLQI score was seen in the patient group aged 30-59 years (mean score 7.05). Malays had significantly higher DLQI scores compared with Indians (P=0.026). Conclusion Patients in our cohort showed a moderate limitation of QoL, comparable to that of other chronic skin diseases. Management should focus not only on medical treatment but also psychological aspects, hence better QoL and treatment outcomes. © 2012 The International Society of Dermatology.

Inspired by Dryobalanops aromatica seed, a new biomimicry marine current turbine is proposed. Hydrodynamic performance and wake properties are two key factors determining whether a new marine current turbine design is practical or not. Thus, a study of hydrodynamic performance and wake of the proposed biomimicry turbine is conducted. The computational fluid dynamics (CFD) software, OpenFOAM is used to generate the required results for the mentioned study. The hydrodynamic performance and wake properties of the proposed biomimicry turbine is compared to two conventional turbines of Bahaj et al. and Pinon et al. respectively. The simulation results showed that the proposed biomimicry marine current turbine gives optimum power output with its power coefficient, Cp ≈ 0.376 at the tip speed ratio (TSR) of 1.5. Under the same boundary conditions, the maximum torque pro- duced by the proposed biomimicry turbine at zero rotational speed is 38.71 Nm which is 1110% greater than the torque generated by the turbine of Bahaj et al. The recovery distance for the wake of the biomimicry turbine is predicted to be 10.6% shorter than that of IFREMER-LOMC turbine. The above-mentioned results confirm the potential application of the proposed biomimicry marine curre- nt turbine in the renewable energy industry. © 2016 Publishing House for Journal of Hydrodynamics.

Tan C.-T.,University of Malaya
Neurology | Year: 2015

Asia is important as it accounts for more than half of the world population. The majority of Asian countries fall into the middle income category. As for cultural traditions, Asia is highly varied, with many languages spoken. The pattern of neurologic diseases in Asia is largely similar to the West, with some disease features being specific to Asia. Whereas Asia constitutes 60% of the world's population, it contains only 20% of the world's neurologists. This disparity is particularly evident in South and South East Asia. As for neurologic care, it is highly variable depending on whether it is an urban or rural setting, the level of economic development, and the system of health care financing. To help remedy the shortage of neurologists, most counties with larger populations have established training programs in neurology. These programs are diverse, with many areas of concern. There are regional organizations serving as a vehicle for networking in neurology and various subspecialties, as well as an official journal (Neurology Asia). The Asian Epilepsy Academy, with its emphasis on workshops in various locations, EEG certification examination, and fellowships, may provide a template of effective regional networking for improving neurology care in the region. © 2015 American Academy of Neurology.

Yusoff N.M.,Multimedia University | Salim S.S.,University of Malaya
Computers and Education | Year: 2012

E-learning storyboards have been a useful approach in distance learning development to support interaction between instructional designers and subject-matter experts. Current works show that researchers are focusing on different approaches for use in storyboards, and there is less emphasis on the effect of design and process difficulties faced by instructional designers and subject-matter experts. This study explores problem aspects of the cognitive task and the skills required of subject-matter experts by applying a cognitive task analysis approach from the expert point of view. The result shows that subject-matter experts face difficulties in making decisions on three elements during e-learning course development. The three elements are storyboard templates, prescriptive interactive components, and review process. It is found that the representation skills and decision making of the three elements allows subject-matter experts to decide on alternatives of the task process. The result also indicates that it is important to leverage the design and process skills of subject-matter experts as it affects their interaction with instructional designers. Three recommendations are made: training development, prescriptive interactive components development, and interaction design document development. A new framework can be recommended to train subject-matter experts as e-learning storyboard users, and in turn provide for effective interaction between them and instructional designers. © 2011 Elsevier Ltd. All rights reserved.

Freeman M.A.,University of Malaya | Ogawa K.,University of Tokyo
International Journal for Parasitology | Year: 2010

Numerous global reports of the species Udonella caligorum, currently thought to be a species complex, suggests that the group may be species-rich. Herein we describe Udonella fugu n. sp., previously described as U. caligorum, found on the parasitic copepod Pseudocaligus fugu infecting Takifugu spp. from Japan. Using morphological data U. fugu can be distinguished from the current valid species by at least one of the traditionally used characters in udonellid taxonomy, and phylogenetic analyses of ssrDNA sequence data for U. fugu and other udonellids confirm that U. fugu forms a distinct clade from other udonellids including U. caligorum. Variable regions in the ssrDNA demonstrated a range of between 2.75 and 5.5% difference between currently recognized species of Udonella. These differences in ssrDNA sequences are phylogenetically useful when distinguishing between morphologically similar udonellids and can be used in conjunction with other data (morphology, phylogeography and fish host) to help clarify udonellid systematics. Udonella fugu was also found to cause significant damage to farmed tiger puffers through their feeding activities. Individual skin lesions were round in shape but merged with adjoining lesions to form more extensive lacerations. In some of the specimens from P. fugu infecting Takifugu niphobles, the protozoan ciliate Trichodina was found on the udonellid body surface and in their intestinal contents. We conclude that the udonellids are a more species-rich group than currently recognized, that early descriptions of new species may have been synonymized with U. caligorum in error and that the frequent global reports of U. caligorum may actually represent new species. This has led to a wide range of morphological descriptions for U. caligorum, blurring the usefulness of morphological data for the group. © 2009 Australian Society for Parasitology Inc.

Yau Y.,University of Malaya
Building Services Engineering Research and Technology | Year: 2010

The air-conditioning system is the major electricity consumption for the non-domestic buildings. A significant part of energy savings can be achieved if heat recovery technologies such as run-around coils, plate-to-plate heat exchangers, heat recovery wheels and heat pipe heat exchangers are incorporated into the ACMV system of these buildings. Non-domestic buildings, such as hospitals, expense even more energy as the supply of fresh air into the space is deemed necessary. For example, air must be changed at least 25 times hourly and recirculation of RA is prohibited for the operating theatres. Therefore, an operating theatre of a hospital in a tropical climate country was chosen for this research. The performance of the existing air-conditioning system has been thoroughly studied to investigate the potential in energy savings in the building. The transient system simulation program (TRNSYS) was used to analyse the air-conditioning system incorporated with heat recovery devices. Generally, there are eight heat recovery systems analysed using TRNSYS, which divided into two groups: the heat recovery ventilating system and heat recovery dehumidification system. The energy savings, payback period, dehumidification enhancement, stability of indoor air conditions and preventing the cross contamination, for each of the systems, were analysed in comparison to each other. Based on this study, it is recommended that the heat recovery systems should be installed to enhance moisture removal and reduce energy usage of HVAC system operating in hospitals. Practical application: The good amount of technical information of real application conducted on heat recovery devices installed in HVAC systems in operating theatres in the tropics could be used as a comprehensive guide for building services engineers and researchers who are intending to apply heat recovery devices as coolness recovery and dehumidification devices in HVAC systems operating in tropical countries. © 2010 The Chartered Institution of Building Services Engineers.

Muthukumar P.,Gandhigram Rural Institute | Balasubramaniam P.,Gandhigram Rural Institute | Ratnavelu K.,University of Malaya
Chaos | Year: 2014

In this paper, we design a new three dimensional King Cobra face shaped fractional order chaotic system. The multi-scale synchronization scheme of two fractional order chaotic systems is described. The necessary conditions for the multi-scale synchronization of two identical fractional order King Cobra chaotic systems are derived through feedback control. A new cryptosystem is proposed for an image encryption and decryption by using synchronized fractional order King Cobra chaotic systems with the supports of multiple cryptographic assumptions. The security of the proposed cryptosystem is analyzed by the well known algebraic attacks. Numerical simulations are given to show the effectiveness of the proposed theoretical results. © 2014 AIP Publishing LLC.

Morris D.J.,University of Stirling | Freeman M.A.,University of Malaya
International Journal for Parasitology | Year: 2010

All of the actinospore releasing oligochaetes collected in an environmental sample were found to be infected with the microsporidian Neoflabelliforma aurantiae n. gen. n. sp. Ultrastructural and phylogenetic studies on this microsporidian indicated similarities with Flabelliforma magnivora but not with the type species Flabelliforma montana, necessitating the formation of a new genus Neoflabelliforma and reassignment of F. magnivora as Neoflabelliforma magnivora n. comb. The development of N. aurantiae is described both parasitising the oligochaete worm and hyperparasitising the concurrent myxosporean infection. The effect of N. aurantiae on the myxosporeans was deleterious and progressive, eventually stopping all actinospore formation. Its discovery has the potential to impact on areas examining the phase of myxosporean life cycles in the invertebrate host, from transmission studies and epidemiology to re-evaluating the basic steps of intra-oligochaete development. Recent evidence has suggested that studies using invertebrate systems should consider possible adverse effects that co-infections can have on experimental outcomes. The discovery of N. aurantiae highlights the need for careful screening of experimental animals to help circumvent erroneous results. © 2009 Australian Society for Parasitology Inc.

Shahrizaila N.,University of Malaya | Yuki N.,National University of Singapore
Journal of Neurology, Neurosurgery and Psychiatry | Year: 2013

In the 1950s, Bickerstaff and Fisher independently described cases with a unique presentation of ophthalmoplegia and ataxia. The neurological features were typically preceded by an antecedent infection and the majority of patients made a spontaneous recovery. In the cases with Bickerstaff brainstem encephalitis, there was associated altered consciousness and in some, hyperreflexia, in support of a central pathology whereas in Fisher syndrome, patients were areflexic in keeping with a peripheral aetiology. However, both authors recognised certain similarities to Guillain-Barré syndrome such as the presence of peripheral neuropathy and cerebrospinal fluid albuminocytological dissociation. The discovery of immunoglobulin G anti-GQ1b antibodies in patients with Fisher syndrome and later in Bickerstaff brainstem encephalitis was crucial in providing the necessary evidence to conclude that both conditions were in fact part of the same spectrum of disease by virtue of their common clinical and immunological profiles. Following this, other neurological presentations that share anti-GQ1b antibodies emerged in the literature. These include acute ophthalmoparesis and acute ataxic neuropathy, which represent the less extensive spectrum of the disease whereas pharyngeal-cervical-brachial weakness and Fisher syndrome overlap with Guillain-Barré syndrome represent the more extensive end of the spectrum. The conditions can be referred to as the 'anti-GQ1b antibody syndrome'. In this review, we look back at the historical descriptions and describe how our understanding of Fisher syndrome and Bickerstaff brainstem encephalitis has evolved from their initial descriptions more than half a century ago.

Khoo S.,University of Malaya | Morris T.,Victoria University of Melbourne
Asia-Pacific Journal of Public Health | Year: 2012

Obesity is a global health concern and has a great impact on countries in the Asia-Pacific region. Physical inactivity is a major risk factor for obesity, but physical activity levels are declining in much of this region. Increasing physical activity is a priority in many countries. Considerable research has been conducted on physical activity related to obesity in Western countries, but populations in the Asia-Pacific region differ in physical, psychological, social, and cultural ways that warrant local and regional research. The authors reviewed research conducted in the Asia-Pacific region that examined either the impact of physical activity interventions on obesity-related outcomes or the effect of behavior-change interventions on physical activity participation. The number of studies found was limited, and their samples and methods varied too much to draw conclusions. The authors recommend further research in the Asia-Pacific region using systematic protocols to permit sound conclusions to be drawn and promote informed action at local levels. © 2012 APJPH.

Ghauth K.I.,Multimedia University | Abdullah N.A.,University of Malaya
Educational Technology and Society | Year: 2011

One of the anticipated challenges of today's e-learning is to solve the problem of recommending from a large number of learning materials. In this study, we introduce a novel architecture for an e-learning recommender system. More specifically, this paper comprises the following phases i) to propose an e-learning recommender system based on content-based filtering and good learners' ratings, and ii) to compare the proposed e-learning recommender system with exiting e-learning recommender systems that use both collaborative filtering and content-based filtering techniques in terms of system accuracy and student's performance. The results obtained from the test data show that the proposed e-learning recommender system outperforms existing e-learning recommender systems that use collaborative filtering and content-based filtering techniques with respect to system accuracy of about 83.28% and 48.58%, respectively. The results further show that the learner's performance is increased by at least 12.16% when the students use the e-learning with the proposed recommender system as compared to other recommendation techniques. © International Forum of Educational Technology & Society (IFETS).

Vythilingam I.,University of Malaya
Frontiers in Physiology | Year: 2012

Malaria and filariasis still continue to pose public health problems in developing countries of the tropics. Although plans are in progress for the elimination of both these parasitic vector borne diseases, we are now faced with a daunting challenge as we have a fifth species, Plasmodium knowlesi a simian malaria parasite affecting humans. Similarly in peninsular Malaysia, filariasis was mainly due to Brugia malayi. However, we now see cases of Wuchereria bancrofti in immigrant workers coming into the country. In order to successfully eliminate both these diseases we need to know the vectors involved and introduce appropriate control measures to prevent the diseases occurring in the future. As for knowlesi malaria it is still uncertain if human to human transmission through mosquito bites is occurring. However, P. knowlesi in human is not a rare occurrence anymore and has all the characteristics of a pathogen spreading due to changes in the ecosystem, international travel, and cross border migration. This has created a more complex situation. In order to overcome these challenges we need to revamp our control measures.This paper reviews the vectors of malaria and filariasis in Southeast Asia with special emphasis on P. knowlesi and W. bancrofti in Malaysia and their control strategies. © 2012 Vythilingam.

Abdullah M.A.,University of Technology Malaysia | Yatim A.H.M.,University of Technology Malaysia | Tan C.W.,University of Technology Malaysia | Saidur R.,University of Malaya
Renewable and Sustainable Energy Reviews | Year: 2012

This paper reviews state of the art maximum power point tracking (MPPT) algorithms for wind energy systems. Due to the instantaneous changing nature of the wind, it is desirable to determine the one optimal generator speed that ensures maximum energy yield. Therefore, it is essential to include a controller that can track the maximum peak regardless of wind speed. The available MPPT algorithms can be classified as either with or without sensors, as well as according to the techniques used to locate the maximum peak. A comparison has been made between the performance of different MPPT algorithms on the basis of various speed responses and ability to achieve the maximum energy yield. Based on simulation results available in the literature, the optimal torque control (OTC) has been found to be the best MPPT method for wind energy systems due to its simplicity. On the other hand, the perturbation and observation (P&O) method is flexible and simple in implementation, but is less efficient and has difficulties determining the optimum step-size. © 2012 Elsevier Ltd. All rights reserved.

Furuoka F.,University of Malaya
Renewable and Sustainable Energy Reviews | Year: 2015

This study revisited the CO2 emissions-development nexus. For this purpose, a comprehensive analysis was performed using recent and extensive datasets and employing three different econometric methods, namely, the cross-sectional regression, the cointegrating regression and the threshold regression. The findings revealed that an environmental regime transformation had occurred in the relationship between the CO2 emission intensity and economic development. Thus, the results indicated that in recent decades the inverted N-shaped cubic relationship between these variables transformed into the inverted U-shaped quadratic relationship. By contrast, as far as the relationship between the CO2 emission per capita and economic development is concerned, the U-shaped relationship between the variables remained unchanged. In other words, the present study has detected the inverted U-shaped or the environmental Kuznets curve (EKC) relationship between the CO2 emission intensity and economic development; however, it was unable to validate the EKC relationship between the CO2 emission per capita and economic development. © 2015 Elsevier Ltd. All rights reserved.

Khiar A.S.A.,Universiti Sains Islam Malaysia | Arof A.K.,University of Malaya
Ionics | Year: 2010

A proton-conducting polymer electrolyte based on starch and ammonium nitrate (NH4NO3) has been prepared through solution casting method. Ionic conductivity for the system was conducted over a wide range of frequency between 50 Hz and 1 MHz and at temperatures between 303 K and 373 K. Impedance analysis shows that sample with 25 wt.% NH4NO3 has a smaller bulk resistance (Rb) compared to that of the pure sample. The amount of NH4NO3 was found to influence the proton conduction; the highest obtainable room temperature conductivity was 2.83 × 10-5 S cm-1, while at 100 °C, the conductivity in found to be 2.09 × 10-4 S cm-1. The dielectric analysis demonstrates a non-Debye behavior. Transport parameters of the samples were calculated using the Rice and Roth model and thus shows that the increase in conductivity is due to the increase in the number of mobile ions. © Springer-Verlag 2009.

Dahlui M.,University of Malaya
Singapore Medical Journal | Year: 2013

INTRODUCTION Cervical cancer is the third most common cancer among Malaysian women. However, the uptake of cervical cancer screening - Pap smear - by women in Malaysia has been low and remains a challenge. This study was conducted to assess the cervical screening practices of rural women in Malaysia and to examine the factors associated with such practices. METHODS A cross-sectional survey was conducted in five rural districts in Perak, Malaysia. 1,000 households were selected through multistage random sampling. Women aged 20-64 years were interviewed by trained enumerators using structured questionnaires. Binomial logistic regression was used to identify predictors of cervical screening through univariate and multivariate analyses. RESUlTS Among the 959 respondents, only 48.9% had undergone Pap smear at least once in the past three years. Women in the age group 40-49 years (odds ratio 3.027, 95% confdence interval 1.546-5.925; p < 0.005) were found to be signifcantly more likely to attend cervical cancer screening as compared to those in the age group 20-29 years. Other signifcant predictors were being married with children, having knowledge of cervical cancer symptoms, receiving relevant information regarding cervical cancer from health personnel or campaigns, being engaged in family planning and receiving encouragement from husbands. CONClUSION Efforts to boost the uptake of Pap smear screening among the rural population should be targeted toward the predictors of positive uptake.

Wong C.-Y.,University of Malaya | Wong C.-Y.,National Tsing Hua University
Scientometrics | Year: 2013

This study attempts to examine systematically the growth trajectories of science, technology and science-based technologies of Japan and South Korea. Drawing upon the empirical materials and findings, this paper provides a detailed description of the evolution and pathways taken by Japan and South Korea to achieve growth in science and technology. Both the quantities (number of papers and patents) and impact (citations) measures of research activities are used to provide a coherent depiction of progress and development trajectories. Japan and South Korea achieved significant progress in production of science and technology. However, both economies experienced a sharp contraction in the number of citations per new patent since the mid 2000s. To address their structural systemic failure, Japan and South Korea have invested heavily in scientific areas that concord with the next wave of technological innovations. The effort has recorded positive effects on science-based technological growth trajectories. © 2013 Akadémiai Kiadó, Budapest, Hungary.

Zukerman-Schpector J.,Federal University of Sao Carlos | Haiduc I.,Babes - Bolyai University | Tiekink E.R.T.,University of Malaya
Chemical Communications | Year: 2011

M-carbonyl(lone pair)⋯π(aryl) interactions provide stability to their transition metal crystal structures. This supramolecular synthon usually leads to zero- or one-dimensional aggregation patterns; a rare example of a three-dimensional architecture based on the M-CO(lone pair)⋯π(aryl) synthon has also been revealed. © The Royal Society of Chemistry 2011.

Ku C.Y.,National University of Singapore | Wong K.B.,University of Malaya
Electronic Journal of Combinatorics | Year: 2012

Let B(n) denote the collection of all set partitions of [n]. Suppose A1, A2 ⊆ B(n) are cross-intersecting i.e. for all A1 ∈ A1 and A2 ∈ A2, we have A1 ∩ A2 ≠ {circled division slash}. It is proved that for sufficiently large n, |A1| |A2| ≤ B2 n-1 where Bn is the n-th Bell number. Moreover, equality holds if and only if A1 = A2 and A1 consists of all set partitions with a fixed singleton.

Arman H.D.,University of Texas at San Antonio | Tiekink E.R.T.,University of Malaya
Zeitschrift fur Kristallographie | Year: 2013

The 1 : 1 co-crystallisation experiments conducted between 1,2,4,5-benzenetetracarboxylic acid, LH4, and each of 2,2′-dipyridyldisulfide (2-PA) and 4,4′-dipyridyldisulfide (4-PA) resulted in the formation of two salts of distinct formulation, i.e. [LH 4]0.5[2-PAH][LH3] (1) and [LH 2][4-PAH2] (2), respectively, indicating that proton transfer had occurred during crystallisation. In 1, a framework structure constructed by hydrogen bonded (O-H...O) LH4 and LH3 - species defines channels in which reside 2-PAH cations that feature syn geometries and intramolecular N-H...N hydrogen bonds. By contrast, in 2, direct N-H...N links between cations and anions lead to zigzag supramolecular chains. © 2013 by Oldenbourg Wissenschaftsverlag, München.

Taha Z.,Universiti Malaysia Pahang | Rostam S.,University of Malaya
International Journal of Advanced Manufacturing Technology | Year: 2011

In respond to new market requirements and competitive positioning of manufacturing companies and in order to provide cost effective, high performance products, there is a need for reconfigurable manufacturing systems with a view of introducing new manufacturing technologies. However one of the problems faced is how to select the alternative machines that are consistent with manufacturing goals. In this paper a decision support system is presented for machine tool selection in flexible manufacturing cell using fuzzy analytic hierarchy process (fuzzy AHP) and artificial neural network. A program is developed in the model to find the Priority weights of the Evaluation Criteria and Alternative's Ranking called PECAR for fuzzy AHP model. The artificial neural network (ANN) is used to verify the results of fuzzy AHP (PECAR program) and to predict the alternatives' ranking. A feed forward back propagation ANN is designed and trained using the results from the program. A numerical example to select the most suitable CNC machine based on data collected from a designed questionnaire is given to demonstrate the applicability of the proposed model. The result of neural net simulation is compared with the results from fuzzy AHP model. It is concluded that the proposed decision support system by combining the fuzzy AHP and ANN models can be used as a powerful tool to select the most suitable alternative machines to form the structure of a flexible manufacturing cell. © 2011 Springer-Verlag London Limited.

Freeman M.A.,University of Malaya | Kasper J.M.,Iceland Marine Research Institute | Kristmundsson A.,University of Iceland
Parasites and Vectors | Year: 2013

Background: Commercial fisheries of lumpfish Cyclopterus lumpus have been carried out in Iceland for centuries. Traditionally the most valuable part is the eggs which are harvested for use as a caviar substitute. Previously reported parasitic infections from lumpfish include an undescribed intranuclear microsporidian associated with abnormal kidneys and mortalities in captive lumpfish in Canada. During Icelandic lumpfish fisheries in spring 2011, extensive enlargements to the kidneys were observed in some fish during processing. The aim of this study was to identify the pathogen responsible for these abnormalities. Methods. Lumpfish from the Icelandic coast were examined for the causative agent of kidney enlargement. Fish were dissected and used in histological and molecular studies. Results: Lumpfish, with various grades of clinical signs, were observed at 12 of the 43 sites sampled around Iceland. From a total of 77 fish examined, 18 had clear clinical signs, the most prominent of which was an extensive enlargement and pallor of the kidneys. The histopathology of the most severely affected fish consisted of extensive degeneration and necrosis of kidney tubules and vacuolar degeneration of the haematopoietic tissue. Intranuclear microsporidians were detected in all organs examined in fish with prominent clinical signs and most organs of apparently healthy fish using the new PCR and histological examination. One or multiple uniformly oval shaped spores measuring 3.12 ± 0.15 × 1.30 ± 0.12 μm were observed in the nucleus of affected lymphocytes and lymphocyte precursor cells. DNA sequencing provided a ribosomal DNA sequence that was strongly supported in phylogenetic analyses in a clade containing other microsporidian parasites from the Enterocytozoonidae, showing highest similarity to the intranuclear microsporidian Nucleospora salmonis. Conclusions: Intranuclear microsporidian infections are common in wild caught lumpfish from around the Icelandic coast. Infections can cause severe clinical signs and extensive histopathological changes, but are also present, at lower levels, in fish that do not show clinical signs. Some common features exist with the intranuclear microsporidian previously reported from captive Canadian lumpfish, but DNA sequence data is required from Canadian fish to confirm conspecificity. Based on phylogenetic analysis and the intranuclear location of the parasite, the name Nucleospora cyclopteri n. sp. is proposed. © 2013 Freeman et al; licensee BioMed Central Ltd.

Vockerodt M.,University of Birmingham | Yap L.-F.,University of Malaya | Shannon-Lowe C.,University of Birmingham | Curley H.,University of Birmingham | And 3 more authors.
Journal of Pathology | Year: 2015

Since the discovery in 1964 of the Epstein-Barr virus (EBV) in African Burkitt lymphoma, this virus has been associated with a remarkably diverse range of cancer types. Because EBV persists in the B cells of the asymptomatic host, it can easily be envisaged how it contributes to the development of B-cell lymphomas. However, EBV is also found in other cancers, including T-cell/natural killer cell lymphomas and several epithelial malignancies. Explaining the aetiological role of EBV is challenging, partly because the virus probably contributes differently to each tumour and partly because the available disease models cannot adequately recapitulate the subtle variations in the virus-host balance that exist between the different EBV-associated cancers. A further challenge is to identify the co-factors involved; because most persistently infected individuals will never develop an EBV-associated cancer, the virus cannot be working alone. This article will review what is known about the contribution of EBV to lymphoma development. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Berman P.R.,University of Michigan | Ooi C.H.R.,University of Malaya
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2012

The propagation of a weak-field pulse through a medium of three-level atoms is considered. Each atom has a Λ-type level scheme in which the two lower levels are stable. A strong control field drives one of the electronic transitions while the signal field drives the coupled transition under conditions where EIT (electromagnetically induced transparency) is usually operative. The input pulse is slowed and compressed as it enters the medium, adiabatically following the EIT solution. However, if the control field is changed suddenly when the pulse is in the medium, the signal field is transformed into two pulses, one of which propagates as a normal EIT pulse and the other with a different speed and an amplitude that oscillates in time. The temporal oscillations are transformed into both spatial and temporal oscillations as the pulse exits the medium. An analytic expression is derived for the pulse intensity which provides a good approximation to the exact result at all times. It is shown that the oscillating component of the exiting pulse can be spatially compressed in comparison with the input pulse. © 2012 American Physical Society.

Introduction Peripartum cardiomyopathy (PPCM) is an uncommon form of congestive heart failure, affecting obstetric patients around the time of delivery. The epidemiology of PPCM is infrequently reported. This study was undertaken to define the prevalence, presentation and outcome of PPCM among women giving birth in a teaching hospital in Malaysia. Methods A retrospective case record analysis was conducted on all patients admitted and diagnosed with PPCM at the University Malaya Medical Centre, Kuala Lumpur, Malaysia, from 1 January 2000 to 31 December 2009. All deliveries were undertaken in the same hospital. Results A total of 12 patients were diagnosed with PPCM during the ten-year study period. The prevalence of PPCM was 2.48 in 100,000 (1 in 40,322) live births. Nine women were diagnosed with PPCM within five months of delivery. Three women had twin pregnancies. There was one death in the group (mortality rate 8.3%). The mean left ventricular ejection fraction at the time of diagnosis was 28.9% ± 8.5% (range 15%-40%). Following the index event, left ventricular function normalised in six of the nine patients (66.7%) who underwent subsequent echocardiography one year later. All patients were treated with standard heart failure therapy. Two patients with normalised left ventricular function had subsequent pregnancies-one pregnancy was terminated at seven weeks and the other patient delivered uneventfully at full term. Conclusion PPCM is uncommon. The outcome in our series was favourable, with 66.7% of patients with PPCM recovering their left ventricular function. The mortality rate was 8.3%.

Salam Z.,University of Technology Malaysia | Amjad M.,University of Technology Malaysia | Amjad M.,Islamia University of Bahawalpur | Facta M.,University of Technology Malaysia | Mekhilef S.,University of Malaya
IEEE Transactions on Power Electronics | Year: 2013

This paper describes the analysis and design of an LCL resonant power supply for ozone generation. The main advantage of the proposed topology is the absence of high-voltage transformer; the high voltage gain is achievable by means of double-resonance phenomena. Furthermore, the bandwidth is wider than the ordinary LC and its phase difference is constant over specific frequency range; as a result, an open-loop operation can be implemented. The complete analysis and design procedure of the power supply is presented. The design procedure is verified by implementing the power supply to drive a dielectric barrier discharge prototype ozone chamber. The hardware results are found to be in close agreement with simulation and thus justify the validity of the design procedures. The proposed circuit is suitable for portable ozone power supply fed by low-voltage source such as battery or photovoltaic module. © 1986-2012 IEEE.

Ward T.A.,University of Malaya
European Journal of Engineering Education | Year: 2013

'Capstone' is a metaphor used to describe a final achievement that builds upon previous works and encapsulates them. Capstone projects are included in engineering curricula to integrate multi-disciplinary subjects and teach professional skills that are difficult to impart in a traditional lectured course. Since these projects serve to transition students into professional engineers, they have a direct impact on a university's industry reputation and ranking. Therefore, it is worthwhile to study the capstone programmes implemented at the world's top-ranked engineering universities to discover common elements which characterise them. In this paper, common elements of the capstone programmes implemented in mechanical and aerospace engineering undergraduate programmes in the world's top-ranked engineering universities are identified and analysed to determine established best practices. These practices can be modelled and applied to the pedagogy of engineering programmes at universities around the world to improve the development of professional skills of future graduates. © 2013 Copyright SEFI.

Thin films consisting of non-ferroelectric inclusions of La2O3 dispersed in a polymer matrix of polyvinylidene difluoride (PVDF) were prepared by the spin-coating method. It was found that the pyroelectric coefficient and remanent polarization of the composites were significantly improved to reach 42 μC/m2 K and 84 mC/m2, respectively. The enhancement of the measured coefficients in the composites can be achieved by introducing a very small amount (3 wt%) of La2O3. The figure of merit for material sensitivity, FD has also improved from 69 to 86 μC/m2 K1. A local field in the inclusion site was shown to facilitate the poling procedure. A simple Maxwell-Wagner model in which the dc conductivity of the inclusion site was taken into consideration showed a good agreement with the obtained pyroelectric and ferroelectric properties. © 2015 Elsevier B.V. All rights reserved.

Singh S.,Ranchi University | Ooi C.H.R.,University of Malaya | Amrita,Ranchi University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2012

Exact solutions are obtained for a collective model of two identical two-level atoms interacting with a quantized bimodal field with intensity-dependent coupling terms in a lossless cavity. A unitary transformation method is used to solve the time-dependent problem that also gives the eigensolutions of the interaction Hamiltonian. The atomic population dynamics and the dynamics of the photon statistics of the two cavity modes are studied. We present evidence of cooperative effects. © 2012 American Physical Society.

In the light of the serious economic crisis of 1997 and Agenda 21, as proposed in the United Nations Conference on Environment and Development in 1992, the Thai government has increased commitments to sustainable agricultural development. This paper examines how local Thai farmers are interacting with the policy imperatives of sustainable agriculture, focusing on the adoption of sustainable practices and farmer livelihoods. Two pummelo producing communities in Chaiyaphum province, Northeast Thailand were chosen as examples and compared: one, located in the highlands, focused on sales for local and domestic markets and the other, located in the lowlands, included sales for export. Both were involved in the implementation of Q-GAP, a public policy for good agricultural practices. The pummelo producers discursively sought the best combination of conventional and sustainable farming practices by balancing the benefits and risks concerning labour requirements, commercial results, financial risks associated with credit loans and investment and ecological sustainability. © 2013 Springer Science+Business Media Dordrecht and International Society for Plant Pathology.

Ibrahim R.W.,University of Malaya
Tamkang Journal of Mathematics | Year: 2013

In this work, we consider a definition for the concept of fractional differential subordination in sense of Srivastava-Owa fractional operators. By employing some types of admissible functions, involving differential operator of fractional order, we illustrate geometric properties such as starlikeness and convexity for a class of analytic functions in the unit disk. Moreover, applications are posed in the sequel.

Abdul-Rahman S.-S.,University of Malaya | Du Boulay B.,University of Sussex
Computers in Human Behavior | Year: 2014

This paper describes an experiment that compared learners with contrasting learning styles, Active vs. Reflective, using three different strategies for learning programming via worked-examples: Paired-method, Structure-emphasising, and Completion. The quality of the learners' acquired cognitive schemata was assessed in terms of their post-test performance. The experiment investigated variations in learners' cognitive load, taking both the learning strategies and the learners' learning styles into account. Overall, the results of the experiment were inconsistent. In comparing the effects of the strategies during the learning phase, the study found significant differences in cognitive load. Unexpectedly, no differences were then detected either in cognitive load or in performance during the post-test (post-test). In comparing the effects of the learning styles during the learning phase and the transfer phase, medium effect sizes suggested that learning style may have had an effect on cognitive load. However, no significant difference was observed in performance during the post-test. © 2013 Elsevier B.V. All rights reserved.

The discovery and invention of new medical applications may be considered blessings to humankind. However, some applications which might be the only remedy for certain diseases may contain ingredients or involve methods that are not in harmony with certain cultural and religious perspectives. These situations have raised important questions in medical ethics; are these applications completely prohibited according to these perspectives, and is there any room for mitigation? This paper explores the concept of darurah (necessity) and its deliberation in the formulation of fatwas on medicine issued by the National Fatwa Council of Malaysia. Darurah has explicitly been taken into consideration in the formulation of 14 out of 45 fatwas on medicine thus far, including one of the latest fatwas regarding uterine donation and transplantation. These fatwas are not only limited to the issues regarding the use of unlawful things as remedies. They include issues pertaining to organ transplantation, management of the corpse and treatment of brain dead patients. While deliberation of darurah in medicine may vary from issue to issue, darurah applies in a dire situation in which there are no lawful means to prevent harm that may be inflicted upon human life. Nevertheless, other aspects must also be taken into the deliberation. For example, consent must be obtained from the donor or his next of kin (after his death) to conduct a cadaveric organ transplantation. © 2015 Springer Science+Business Media Dordrecht

Ellis L.,University of Malaya | Hoskin A.W.,Idaho State University
Aggression and Violent Behavior | Year: 2015

Evolutionary neuroandrogenic (ENA) theory contends that males are more involved in crime than females due to an evolved female preference for mates who are (or at least appear to be) stable resource provisioners. To accommodate this female preference, the theory states that males have evolved genetic tendencies to produce a high level of testosterone and other androgens that enhance their competitiveness, often to the point of victimizing others. Adolescent expressions of competitive/victimizing behavior are often crude, thus frequently manifesting themselves in the form of behavior that others seek to suppress. By full adulthood, most individuals with highly androgenized brains will have transitioned from crude forms to refined forms of competitive/victimizing behavior, typically as part of their normal occupational and financial activities. The theory asserts that learning ability as well as opportunities to learn forms of competition that minimally victimize others, determine how fast individuals transition from crude to refined forms of competitiveness. In the present article, ENA theory is elaborated upon and used to explain three phenomena not previously addressed by the theory: (a) the rise of the criminal justice system, (b) the criminalization of victimless offenses, and (c) gang activities and terrorism. According to the theory, all of these phenomena have similar evolutionary and neurohormonal underpinnings. © 2015.

Ellis L.,University of Malaya | Hoskin A.W.,University of Texas of the Permian Basin
International Journal of Offender Therapy and Comparative Criminology | Year: 2015

A decade old theory hypothesizes that brain exposure to androgens promotes involvement in criminal behavior. General support for this hypothesis has been provided by studies of postpubertal circulating levels of testosterone, at least among males. However, the theory also predicts that for both genders, prenatal androgens will be positively correlated with persistent offending, an idea for which no evidence currently exists. The present study used an indirect measure of prenatal androgen exposure - the relative length of the second and fourth fingers of the right hand (r2D:4D) - to test the hypothesis that elevated prenatal androgens promote criminal tendencies later in life for males and females. Questionnaires were administered to 2,059 college students in Malaysia and 1,291 college students in the United States. Respondents reported their r2D:4D relative finger lengths along with involvement in 13 categories of delinquent and criminal acts. Statistically significant correlations between the commission of most types of offenses and r2D:4D ratios were found for males and females even after controlling for age. It is concluded that high exposure to androgens during prenatal development contributes to most forms of offending following the onset of puberty. © The Author(s) 2013.

Samsudin N.I.P.,University Putra Malaysia | Abdullah N.,University of Malaya
Mycotoxin Research | Year: 2013

Red rice is a fermented product of Monascus spp. It is widely consumed by Malaysian Chinese who believe in its pharmacological properties. The traditional method of red rice preparation disregards safety regulation and renders red rice susceptible to fungal infestation and mycotoxin contamination. A preliminary study was undertaken aiming to determine the occurrence of mycotoxigenic fungi and mycotoxins contamination on red rice at consumer level in Selangor, Malaysia. Fifty red rice samples were obtained and subjected to fungal isolation, enumeration, and identification. Citrinin, aflatoxin, and ochratoxin-A were quantitated by ELISA based on the presence of predominant causal fungi. Fungal loads of 1.4×104 to 2.1×10 6 CFU/g exceeded Malaysian limits. Monascus spp. as starter fungi were present in 50 samples (100%), followed by Penicillium chrysogenum (62%), Aspergillus niger (54%), and Aspergillus flavus (44%). Citrinin was present in 100% samples (0.23-20.65 mg/kg), aflatoxin in 92% samples (0.61-77.33 μg/kg) and Ochratoxin-A in 100% samples (0.23-2.48 μg/kg); 100% citrinin and 76.09% aflatoxin exceeded Malaysian limits. The presence of mycotoxigenic fungi served as an indicator of mycotoxins contamination and might imply improper production, handling, transportation, and storage of red rice. Further confirmatory analysis (e.g., HPLC) is required to verify the mycotoxins level in red rice samples and to validate the safety status of red rice. © Society for Mycotoxin Research and Springer-Verlag 2012.

Lam S.K.,University of Malaya
Expert Review of Vaccines | Year: 2013

Dengue is a major public health concern worldwide, with the number of infections increasing globally. The illness imposes the greatest economic and human burden on developing countries that have limited resources to deal with the scale of the problem. No cure for dengue exists; treatment is limited to rehydration therapy, and with vector control strategies proving to be relatively ineffective, a vaccine is an urgent priority. Despite the numerous challenges encountered in the development of a dengue vaccine, several vaccine candidates have shown promise in clinical development and it is believed that a vaccination program would be at least as cost-effective as current vector control programs. The lead candidate vaccine is a tetravalent, live attenuated, recombinant vaccine, which is currently in Phase III clinical trials. Vaccine introduction is a complex process that requires consideration and is discussed here. This review discusses the epidemiology, burden and pathogenesis of dengue, as well as the vaccine candidates currently in clinical development. © Informa Healthcare.

Haerian B.S.,University of Malaya
Pharmacogenomics | Year: 2013

A majority of studies have shown a link between the common functional rs6265 polymorphism of the BDNF gene and susceptibility to drug dependence. However, the pattern of results is inconsistent. To precisely evaluate this association, a systematic review and meta-analysis of previous case-control reports was conducted. Data from 20 studies containing 9419 participants (4665 cases and 4754 controls) conducted between 2004 and 2013 restricted to alcohol, nicotine, heroin, substance and methamphetamine dependency were meta-analyzed. Following quality control of the results, a significant association between C allele and methamphetamine dependence remained in south Asian subjects (p = 0.004). Similar results were detected in south Asian subjects for methamphetamine dependence and in Chinese subjects for heroin dependence under an autosomal codominant genotype model (TT vs CC, p = 0.005 and p = 0.0004, respectively). In conclusion, the rs6265 polymorphism may be a risk factor for methamphetamine dependence in south Asian subjects or for heroin dependence in Chinese subjects. © 2013 Future Medicine Ltd.

Saidun S.,University of Malaya
Journal of Medical Ethics | Year: 2013

Visual recording of human subjects is commonly used in biomedical disciplines for clinical, research, legal, academic and even personal purposes. Guidelines on practice standards of biomedical recording have been issued by certain health authorities, associations and journals, but none of the literature discusses this from an Islamic perspective. This article begins with a discussion on the general rules associated with visual recording in Islam, followed by modesty issues in biomedical recording and issues of informed consent and confidentiality. In order to be deemed ethical from the Islamic perspective, all the aforementioned criteria must conform to, or not contradict, Islamic teaching.

Concrete is heavily used as a construction material in modern society. With the growth in urbanization and industrialization, the demand for concrete is increasing day by-days. Therefore, raw materials and natural resources are required in large quantities for concrete production worldwide. At the same time, a considerable quantity of industrial waste, agricultural waste and other types of solid material disposal are posing serious environmental issues. To minimize and reduce the negative impact of the concrete industry through the explosive usage of raw materials, the use of artificial wastes as supplementary cementitious materials, the source of which are both reliable and suitable for alternative preventive solutions promotes the environmental sustainability of the industry. This paper reviews the possible use of industrial and agricultural wastes as a supplementary cementitious material in the production of concrete. It aims to exhibit the idea of utilizing these wastes by elaborating upon their engineering, physical and chemical properties. This provides a summary of the existing knowledge about the successful use of artificial wastes such as fly ash, slag, silica fume, rice husk ash, palm oil fuel ash, sugar cane bagasse ash, wood waste ash, bamboo leaf ash, and corn cob ash in the concrete industry. © 2016.

Sultan Aljibori H.S.,University of Malaya
European Journal of Scientific Research | Year: 2010

The energy absorption capacity of a sequence of axially crushed composite tubes fabricated from high tow count filament glass fiber have different number of layers (4, 6, 8, and 10 layers), to determine the viability of considering the use of such fibers in automotive applications. To that end, glass-epoxy tubular specimens with circular cross-sectional geometry and 0/90° fibers orientation angle were fabricated and crushed by quasi-static test to examine the energy absorption characteristics and to calculate the crashworthiness parameters. Three specimens were fabricated and tested at same conditions of these tubes. Twelve specimens were crushed by using INSTRON machine. In order to characterize the tubes and specimens, a number of measurements were taken. These measurements included wall thickness, cross-sectional dimensions, volume and mass. The results showed that the number of layers and fiber orientation angle had a significant effect on the energy absorption capability. © EuroJournals Publishing, Inc. 2010.

Jalab H.A.,University of Malaya
2011 IEEE Conference on Open Systems, ICOS 2011 | Year: 2011

The current paper presents a content-based image retrieval (CBIR) system using the image features extracted by a color layout descriptor (CLD) and Gabor texture descriptor. CLD represents the spatial distribution of colors with a few nonlinear quantized DCT coefficients of grid-based average colors, whereas the Gabor filter works as a bandpass filter for the local spatial frequency distribution. These two descriptors are very powerful for CBIR systems. Furthermore, combining the color and texture features in CBIR systems leads to more accurate results for image retrieval. To compare the performance of image retrieval method, average precision and recall are computed for all queries. The results showed an improved performance (higher precision and recall values) compared with the performance using other CBIR methods. © 2011 IEEE.

Nanostructured network-like MnO2 -NiO composite electrodes were electrodeposited onto stainless steel substrates via different electrodeposition modes, such as chronopotentiometry, chronoamperometry, and cyclic voltammetry, and then subjected to heat treatment at 300° C for metal oxide conversion. X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy were used to study the crystalline natures and morphologies of the deposited films. The electrochemical properties were investigated using cyclic voltammetry and charge/discharge tests. The results revealed that the electrochemical performance of the as-obtained composite electrodes depended on the electrodeposition mode. The electrochemical properties of MnO2-NiO composite electrodes prepared using cyclic voltammetry exhibited the highest capacitance values and were most influenced by the deposition cycle number. The optimum specific capacitance was 3509 Fg-1 with energy and power densities of 1322 Wh kg-1 and 110.5 kW kg-1 , respectively, at a current density of 20 Ag-1 in a mixed KOH/K3 Fe(CN)6 electrolyte. © 2016 Rusi, Majid. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Ramasamy R.,University of Malaya | Tuan Ya T.M.Y.S.,Petronas University of Technology
Applied Ocean Research | Year: 2014

The venture of oil and gas exploration into deeper waters has increased drastically in these recent years, as the shallow water fields approaching exhaustion. Large diameter pipelines installed in these areas are exposed to the severe pressure loading resulting from the water depth and any pre-installation damages sustained during transportation or pipelay and may reduce the collapse and buckle propagation resistance drastically. This work focuses on the utilisation and application of the finite element method as a robust and practical engineering tool to establish a methodology for analysing the effects of initial imperfections in the form of dents of various shapes and sizes on pipelines, sustained prior to pipelay, to determine the collapse pressure and buckle propagation pressure which can result in costly abandonments and unnecessary replacements. Comparison between the available theoretical closed-form simplified solutions available via 2D ring analogy, the experimental test conducted by various researchers on steel tubes, empirical formulations from past works and the analysis results obtained from this research were conducted, by incorporating the material plasticity, residual stresses and external pressure. The methodology employed herein provides a relatively realistic and practical assessment tool for computing the collapse and buckle propagation pressures of dented large-diameter submarine pipelines. © 2014 Elsevier Ltd.

Miao J.,University of Science and Technology Beijing | Hooi Chew K.,University of Malaya | Jiang Y.,University of Science and Technology Beijing
Applied Physics Letters | Year: 2011

(Ba 0.8Sr 0.2)(Zr 0.2Ti 0.8)O 3 (BSZT) films were grown on La 0.5Sr 0.5CoO 3 buffered (001) SrTiO 3 substrates by pulsed laser deposition. Effects of Co doping on electrical properties of the films were investigated to establish material design through defects control. The doping led to a significant improvement in the electrical properties with reduction in leakage current and dielectric loss. In addition, the dielectric tunability and figure of merit were enhanced, implying that Co-doped BSZT films are promising materials for tunable microware applications. Our detail studies suggest that the improved electrical properties of Co-doped BSZT films are closely related to defect concentrations in the films. © 2011 American Institute of Physics.

Haerian B.S.,University of Malaya | Haerian M.S.,Shahid Beheshti University of Medical Sciences
Pharmacogenomics | Year: 2013

The OPRM1 gene encodes the μ-opioid receptor, which is the primary site of action of most opioids. Several studies and three meta-analyses have examined a possible link between the exonic OPRM1 A118G (rs1799971) polymorphism and opioid dependence; however, results have been inconclusive. Therefore, a systematic review and meta-analysis have been carried out to examine whether this polymorphism is associated with opioid dependence. Thirteen studies (n = 9385), comprising 4601 opioid dependents and 4784 controls, which evaluated association of the OPRM1 rs1799971 polymorphism with susceptibility to opioids, were included in this study. Our meta-analysis showed significant association between this polymorphism and susceptibility to opioid dependence in overall studies under a codominant model, as well as susceptibility to opioid dependence or heroin dependence in Asians under an autosomal dominant model. The nonsynonymous OPRM1 rs1799971 might be a risk factor for addiction to opioids or heroin in an Asian population. © 2013 Future Medicine Ltd.

Shields M.D.,Queens University of Belfast | Thavagnanam S.,University of Malaya
Cough | Year: 2013

Cough is one of the most common symptoms that patients bring to the attention of primary care clinicians. Cough can be designated as acute (<3 weeks in duration), prolonged acute cough (3 to 8 weeks in duration) or chronic (> 8 weeks in duration). The use of the term 'prolonged acute cough' in a cough guideline allows a period of natural resolution to occur before further investigations are warranted. The common causes are in children with post viral or pertussis like illnesses causing the cough. Persistent bacterial bronchitis typically occurs when an initial dry acute cough due to a viral infection becomes a prolonged wet cough remaining long after the febrile illness has resolved. This cough responds to a completed course of appropriate antibiotics. © 2013 Shields and Thavagnanam; licensee BioMed Central Ltd.

Nissapatorn V.,University of Malaya | Sawangjaroen N.,Prince of Songkla University
Indian Journal of Medical Research | Year: 2011

After 30 years of the human immunodeficiency virus (HIV) epidemic, parasites have been one of the most common opportunistic infections (OIs) and one of the most frequent causes of morbidity and mortality associated with HIV-infected patients. Due to severe immunosuppression, enteric parasitic pathogens in general are emerging and are OIs capable of causing diarrhoeal disease associated with HIV. Of these, Cryptosporidium parvum and Isospora belli are the two most common intestinal protozoan parasites and pose a public health problem in acquired immunodeficiency syndrome (AIDS) patients. These are the only two enteric protozoan parasites that remain in the case definition of AIDS till today. Leismaniasis, strongyloidiasis and toxoplasmosis are the three main opportunistic causes of systemic involvements reported in HIV-infected patients. Of these, toxoplasmosis is the most important parasitic infection associated with the central nervous system. Due to its complexity in nature, toxoplasmosis is the only parasitic disease capable of not only causing focal but also disseminated forms and it has been included in AIDS-defining illnesses (ADI) ever since. With the introduction of highly active anti-retroviral therapy (HAART), cryptosporidiosis, leishmaniasis, schistosomiasis, strongyloidiasis, and toxoplasmosis are among parasitic diseases reported in association with immune reconstitution inflammatory syndrome (IRIS). This review addresses various aspects of parasitic infections in term of clinical, diagnostic and therapeutic challenges associated with HIV-infection.

Daud A.-K.,Palestine Polytechnic University | Ismail M.S.,University of Malaya
Renewable Energy | Year: 2012

Hybrid power systems based on renewable energy sources, especially photovoltaic and wind energy are an effective option to solve the power-supply problem for remote and isolated areas far from the grids. This paper presents a study and design of a complete hybrid system for providing the electrical loads in a family house in Palestine according to their energy requirements.A computer program is developed to achieve this and to determine the specifications of the whole system components. It uses the data of wind and solar radiation measurements of the selected rural zone and all the required information about the electrical loads. Also, the hybrid systems minimizing, simultaneously, the total cost throughout the useful life of the installation, pollutant emissions (CO 2) and dump load are taken into consideration.It is found that providing electricity to a family house in a rural zone using hybrid systems is very beneficial and competitive with the other types of conventional energy sources, especially considering the decreasing prices of these systems and their increasing efficiencies and reliability. They have also the advantage of maintaining a clean environment. © 2012 Elsevier Ltd.

Amekawa Y.,University of Malaya
Journal of Peasant Studies | Year: 2013

Since the early 2000s, the governments in ASEAN (the Association of South East Asian Nations) countries have developed 'good agricultural practices' (GAP) as public approaches to field-level quality assurance. Besides the primary goals of consumer food safety and quality assurance, these public GAP programs aim to support small-scale farmer inclusion in mainstream markets. This goal represents the antithesis of the prevailing trend that private GAP approaches have tightened integration with resourceful, large-scale producers in global value chains. This paper examines the compatibility of the goals of safety assurance and social justice in a public GAP approach through comparative analysis of Thailand's Q-GAP between two local contexts of fruit production and marketing. The research findings suggest that while the public GAP scheme could draw the participation of a broad cohort of local small-scale producers and serve to certify their production, its impact on changing producers' on-field practices and catalyzing their access to the global market through food safety assurance is limited. The binding factors include the lack of producers' understanding of the principles of the programme, limited additional economic merits for them, and the influence of extra-local market forces that stress economies of size and food quality rather than food safety. © 2013 Copyright Taylor and Francis Group, LLC.

Ho C.C.K.,University of Kuala Lumpur | Tan H.M.,University of Malaya
Current Urology Reports | Year: 2011

Herbal medicine long has been used in the management of sexual dysfunction, including erectile dysfunction. Many patients have attested to the efficacy of this treatment. However, is it evidence-based medicine? Studies have been done on animal models, mainly in the laboratory. However, randomized controlled trials on humans are scarce. The only herbal medications that have been studied for erectile dysfunction are Panax ginseng, Butea superba, Epimedium herbs (icariin), Tribulus terrestris, Securidaca longipedunculata, Piper guineense, and yohimbine. Of these, only Panax ginseng, B. superb, and yohimbine have published studies done on humans. Unfortunately, these published trials on humans were not robust. Many herbal therapies appear to have potential benefits, and similarly, the health risks of various phytotherapeutic compounds need to be elucidated. Properly designed human trials should be worked out and encouraged to determine the efficacy and safety of potential phytotherapies. © 2011 Springer Science+Business Media, LLC.

Thanapackiam P.,University of Malaya
Disaster Advances | Year: 2012

Slope failures intensity and frequency had increased in the last decade. This study examines the trend change form of slope failures and the directional spatial tendency of slope failures in the last decade in the Klang Valley Region (KVR) of Malaysia. The temporal and spatial changes have great significance on population vulnerability in the KVR. Two significant effects identified are first the increasing intensity - frequency impact of slope failures on KVR population and secondly the spatial direction of the impacts in the KVR. Both of these effects create severe stresses on the population of the KVR. The study observed that the temporal and spatial advances of slope failures would continue to increase in intensity and frequency in the not so distant future as the environment would become more stressful as a result of urbanization.

Varikoden H.,Indian Institute of Tropical Meteorology | Samah A.A.,University of Malaya | Babu C.A.,Cochin University of Science and Technology
Journal of Hydrology | Year: 2010

The present study is focused on the intensity distribution of rainfall in different classes and their contribution to the total seasonal rainfall. In addition, we studied the spatial and diurnal variation of the rainfall in the study areas. For the present study, we retrieved data from TRMM (Tropical Rain Measuring Mission) rain rate available in every 3 h temporal and 25 km spatial resolutions. Moreover, station rainfall data is used to validate the TRMM rain rate and found significant correlation between them (linear correlation coefficients are 0.96, 0.85, 0.75 and 0.63 for the stations Kota Bharu, Senai, Cameron highlands and KLIA, respectively). We selected four areas in the Peninsular Malaysia and they are south coastal, east coastal, west coastal and highland regions. Diurnal variation of frequency of rain occurrence is different for different locations. We noticed bimodal variation in the coastal areas in most of the seasons and unimodal variation in the highland/inland area. During the southwest monsoon period in the west coastal stations, there is no distinct diurnal variation. The distribution of different intensity classes during different seasons are explained in detail in the results. © 2010 Elsevier B.V.

Jenatabadi H.S.,University of Malaya
Applied Mathematical Sciences | Year: 2014

The main objective of this study is to apply moderation analysis in structural equation modeling (SEM) to compare management information system (MIS) and enterprise resource planning (ERP). This comparison study is implemented in the relationship among, organizational learning, innovation, and performance. 168 companies in food production factories were selected from Malaysia, China, and Taiwan. The results show that even the implementation cost between MIS and ERP is quite different, but there is no significant difference between two systems in their innovation models. © 2014 Hashem Salarzadeh Jenatabadi.

Wong L.P.,University of Malaya | Sam I.-C.,Tropical Infectious Diseases Research and Education Center
Vaccine | Year: 2010

The study aimed to determine factors influencing the uptake of 2009 H1N1 influenza vaccine in a multiethnic Asian population. Population-based, cross-sectional survey was conducted between October and December 2009. Approximately 70% of overall participants indicated willingness to be vaccinated against the 2009 H1N1 influenza. Participants who indicated positive intention to vaccinate against 2009 H1N1 influenza were more likely to have favorable attitudes toward the 2009 H1N1 vaccine. A halal (acceptable to Muslims) vaccine was the main factor that determined Malay participants' decision to accept vaccination, whereas safety of the vaccine was the main factor that influenced vaccination decision for Chinese and Indian participants. The study highlights the challenges in promoting the 2009 H1N1 vaccine. Ethnic-sensitive efforts are needed to maximize acceptance of H1N1 vaccines in countries with diverse ethnic communities and religious practices. © 2010 Elsevier Ltd. All rights reserved.

A microsporidian hyperparasite, Desmozoon lepeophtherii, of the parasitic copepod Lepeophtheirus salmonis (salmon louse), infecting farmed Atlantic salmon (Salmo salar), was first discovered in the west of Scotland in 2000. Heavily infected salmon lice are easily recognised as they have large opaque inclusions distributed throughout the body. The prevalence of salmon lice with visible signs of microsporidiosis can be up to 10% of the population from certain farm sites. The microsporidian was also isolated from the host Atlantic salmon suggesting it may have a two host life cycle. The authors believe that the infection in immunocompetent salmon may be latent, becoming acute during periods of infection with another pathogen or during sexual maturation. Since its first discovery in Scotland, Desmozoon lepeophtherii has been subsequently reported from Norway, and more recently from the Pacific coast of North America. © 2011 Freeman and Sommerville; licensee BioMed Central Ltd.

Nasir M.H.N.,University of Malaya | Sahibuddin S.,University of Technology Malaysia
Scientific Research and Essays | Year: 2011

Although there have been studies completed on the critical success factors of software projects, these studies all have been specific to one particular country. There has been no comprehensive study reporting on different project sizes in various domains and in multiple countries. We present our extensive literature survey of critical success factors that impact software projects. Forty-three articles from the years 1990 to 2010 were found to be significant contributions that could be analysed in order to develop a list of critical factors that specifically affect the success of software projects. The method of content analysis and frequency analysis was adopted. Twenty-six critical success factors were found to be related to software project success. We suggest that organisation or project manager is attentive to control the top five critical factors to drive towards project success since the percentage of frequency of occurrences for each is more than 50%. Also, it appears that non-technical factors (94%) dominated over technical factors (6%). In a result unique to our study compared with previous one, we found that the factors of clear and frozen requirements, realistic estimation of the schedule and budget, along with a competent project manager are the five most critical success factors of software projects. © 2011 Academic Journals.

Moy F.M.,University of Malaya
Journal of Photochemistry and Photobiology B: Biology | Year: 2011

Vitamin D status is influenced by sun exposure, geographic latitude, daily outdoor activities, body surface exposed to sunlight and dietary intakes. Malaysia, is sunny all year round. However, the vitamin D status of this population especially among the healthy and free living adults is not known. Therefore a study of vitamin D status and associated factors was initiated among an existing Malay cohort in Kuala Lumpur. A total of 380 subjects were sampled to have their vitamin D status assessed using 25-hydroxyvitamin D (25(OH)D). A short questionnaire enquiring socio-demographic characteristics, exposure to sunlight and clothing style was administered. Their mean age was 48.5 ± 5.2 years and the mean 25(OH)D for males and females were 56.2 ± 18.9 nmol/L and 36.2 ± 13.4 nmol/L respectively. There were significant positive correlation for sun exposure score (r = 0.27, p < 0.001) and negative correlation for sun protection score (r = -0.41, p < 0.001) with 25(OH)D levels. In the logistic regression model, females (OR = 2.93; 95% CI: 1.17, 7.31), BMI (1.1; 1.03, 1.20) and sun exposure score (0.998; 0.996, 0.999) were significantly associated with vitamin D status as represented by 25(OH)D levels. Our findings show that obesity, lifestyle behaviours and clothing style are directly associated with our participants especially females' low vitamin D status. © 2011 Elsevier B.V. All rights reserved.

Pang Y.K.,University of Malaya
Malaysian Family Physician | Year: 2014

Tuberculosis (TB) remains a very common disease in most of the low- and middle-income countries. As a result of high disease burden, TB control measures in these countries are usually concentrated on intensifying active disease case-finding and early treatment of infectious TB. On the contrary, in countries with low disease burden, the focus is on contact investigation to identify latently infected individuals and prophylactically treating them to prevent disease reactivation and transmission. These two strategies are deemed important for the effective TB control. Nonetheless, WHO cautions that targeted contact investigation and latent TB infection (LTBI) treatment should only be undertaken by countries that have the operational capacity/ resources and have achieved ≥ 85% treatment success rate of active TB. The screening of LTBI is further challenged by the lack of a “gold standard” test to identify and validate individuals with this condition. Tuberculin skin test (TST) is still the preferred investigation as it is cheap, widely available and validated in many trials. The sensitivity and specificity of the newer test—interferon gamma release assay (IGRA) for LTBI screening has been encouraging in low prevalence countries. However, the evidence supporting such usage remains uncertain in high burden settings. Diagnosis of LTBI should adhere to the strict criteria outlined in the guidelines to avoid misdiagnosing active TB as LTBI. The treatment of the latter involved only one or two anti-TB drugs. It has been demonstrated that in the properly conducted contact screening and LTBI treatment, chances of the emergence of multi-drug-resistant TB is very low. © 2014, Academy of Family Physicians of Malaysia. All rights reserved.

Hasima N.,University of Houston | Hasima N.,University of Malaya | Aggarwal B.B.,University of Houston
International Journal of Biochemistry and Molecular Biology | Year: 2012

In spite of major advances in oncology, the World Health Organization predicts that cancer incidence will double within the next two decades. Although it is well understood that cancer is a hyperproliferative disorder mediated through dysregulation of multiple cell signaling pathways, most cancer drug development remains focused on modulation of specific targets, mostly one at a time, with agents referred to as "targeted therapies," "smart drugs," or "magic bullets." How many cancer targets there are is not known, and how many targets must be attacked to control cancer growth is not well understood. Although more than 90% of cancer-linked deaths are due to metastasis of the tumor to vital organs, most drug targeting is focused on killing the primary tumor. Besides lacking specificity, the targeted drugs induce toxicity and side effects that sometimes are greater problems than the disease itself. Furthermore, the cost of some of these drugs is so high that most people cannot afford them. The present report describes the potential anticancer properties of curcumin, a component of the Indian spice turmeric (Curcuma longa), known for its safety and low cost. Curcumin can selectively modulate multiple cell signaling pathways linked to inflammation and to survival, growth, invasion, angiogenesis, and metastasis of cancer cells. More clinical trials of curcumin are needed to prove its usefulness in the cancer setting.

Furuoka F.,University of Malaya
Renewable and Sustainable Energy Reviews | Year: 2015

This paper examined relationships between financial development and energy consumption in Asia for the period of 1980-2012. For the purpose of the empirical analysis, it performed the heterogeneous panel causality test suggested by Dumitrescu and Hurlin [1]. The findings of the panel cointegration test indicated that there was a long run equilibrium relationship between finance and energy consumption in the region. Moreover, the heterogeneous panel causality test detected a unidirectional causality from energy consumption to financial development but not vice versa. These results indicate that an expansion of energy usage could be a driving force behind financial development in Asia. © 2015 Elsevier Ltd. All rights reserved.

Tiekink E.R.T.,University of Malaya
Chemical Communications | Year: 2014

In this Viewpoint, the impact of the paper published by Gautam R. Desiraju and Angelo Gavezzotti (J. Chem. Soc., Chem. Commun., 1989, 621) upon the development of Crystal Engineering, now recognised a key discipline in contemporary chemical/pharmaceutical/materials science, is discussed. © 2014 the Partner Organisations.

Introduction: This study assessed the information needs, preferred educational messages and channels of delivery, as well as opinions on strategies to promote organ donation. It aimed to provide insight into a culturally sensitive public education campaign to encourage organ donation in diverse ethnic communities in Asia, namely the Malays, Chinese and Indians. Methods: A total of 17 focus group discussions with 105 participants were conducted between September and December 2008. The participants were members of the general public aged 18 to 60 years, who were recruited through convenient sampling in the Klang Valley area of Malaysia. Results: Across ethnic groups, there was a general concern about the mistreatment of the deceased's body in the organ procurement process. The Chinese and Indian participants wanted assurance that the body would be treated with respect and care. The Muslims wanted assurance that the handling of a Muslim's body would follow the rules and regulations of the Islamic faith. The most important information requested by the Muslim participants was whether cadaveric donation is permissible in Islam. A lack of national public education and promotion of organ donation was noted. All the three ethnic groups, especially the Malays, required community and religious leaders for support, encouragement and involvement, as sociocultural influences play a significant role in the willingness to donate organs. Conclusion: The pronounced ethnic differences in information needs suggest that culturally sensitive public educational messages are required. Organ donation and transplantation organisations should work closely with community and religious organisations to address the sociocultural barriers identified.

Enayatifar R.,University of Technology Malaysia | Sadaei H.J.,University of Technology Malaysia | Abdullah A.H.,University of Technology Malaysia | Gani A.,University of Malaya
Energy Conversion and Management | Year: 2013

In this study, a hybrid algorithm based on a refined high-order weighted fuzzy algorithm and an imperialist competitive algorithm (RHWFTS-ICA) is developed. This method is proposed to perform efficiently under short-term load forecasting (STLF). First, autocorrelation analysis was used to recognize the order of the fuzzy logical relationships. Next, the optimal coefficients and optimal intervals of adaption were obtained by means of an imperialist competitive algorithm in the training dataset. Lastly, the obtained information was employed to forecast the 48-step-ahead of the STLF problems. To validate the proposed method, eight case studies of real load data, collected from the UK and France during the years 2003 and 2004, were tested with the proposed algorithm and certain enhanced STLF forecasting models. The numerical results demonstrated the efficiency of the proposed algorithm in terms of the forecast accuracy. © 2013 Elsevier Ltd. All rights reserved.

Tang W.S.,Bayan Baru Health Clinic | Khoo E.M.,University of Malaya
Journal of Sexual Medicine | Year: 2011

Introduction. Premature ejaculation (PE) is common. However, it has been underreported and undertreated. Aims. To determine the prevalence of PE and to investigate possible associated factors of PE. Methods. This cross-sectional study was conducted at a primary care clinic over a 3-month period in 2008. Men aged 18-70 years attending the clinic were recruited, and they completed self-administered questionnaires that included the Premature Ejaculation Diagnostic Tool (PEDT), International Index of Erectile Function, sociodemography, lifestyle, and medical illness. The operational definition of PE included PE and probable PE based on the PEDT. Main Outcome Measure. Prevalence of PE. Results. A total of 207 men were recruited with a response rate of 93.2%. There were 97 (46.9%) Malay, 57 (27.5%) Chinese, and 53 (25.6%) Indian, and their mean age was 46.0±12.7 years. The prevalence of PE was 40.6% (N=82) (PE: 20.3%, probable PE: 20.3% using PEDT). A significant association was found between ethnicity and PE (Indian 49.1%, Malay 45.4%, and Chinese 24.6%; χ2=8.564, d.f.=2, P=0.014). No significant association was found between age and PE. Multivariate analysis showed that erectile dysfunction (adjusted odds ratio [OR] 4.907, 95% confidence interval [CI] 2.271, 10.604), circumcision (adjusted OR 4.881, 95% CI 2.346, 10.153), sexual intercourse ≤5 times in 4 weeks (adjusted OR 3.733, 95% CI 1.847, 7.544), and Indian ethnicity (adjusted OR 3.323, 95% CI 1.489, 7.417) were predictors of PE. Conclusion. PE might be frequent in men attending primary care clinics. We found that erectile dysfunction, circumcision, Indian ethnicity, and frequency of sexual intercourse of ≤5 times per month were associated with PE. These associations need further confirmation. © 2011 International Society for Sexual Medicine.

Objective: Bacterial resistance to antibiotics is the single most important determinant of treatment success. The objective of this study was to determine the prevalence of Helicobacter pylori resistance to clarithromycin, amoxicillin, metronidazole, tetracycline, levofloxacin, rifabutin, and furazolidone in our local bacterial strains. Methods: Samples from consecutive ninety patients were obtained for culture and sensitivity testing. Resistance to individual antibiotics were tested using the E-test and MIC90 read from the strips. Resistance to rifampicin and nitrofurantoin were used as a surrogate for rifabutin and furazolidine. Results: There was a high prevalence of resistance to metronidazole 68/90 (75.5%). No male (34/45 (75.5%) versus female (35/45 (77.7%) difference in frequency of metronidazole resistance was noted (p=1.000). There was zero resistance 0 to clarithromycin, levofloxacin, amoxicillin, and nitrofurantoin/furazolidone. Resistance to rifampicin/rifabutin was for breakpoints of 1 and 4μg/mL of 14.4 and 2.2% respectively. Conclusions: Although there was high bacterial resistance to metronidazole, the absence of resistance particularly to the key antibiotics used in H. pylori eradication therapy: clarithromycin and levofloxacin is reassuring to note. Continued monitoring of antibiotic resistance should be carried out. © 2011 Blackwell Publishing Ltd.

Chai H.C.,University of Selangor | Phipps M.E.,University of Selangor | Chua K.H.,University of Malaya
Clinical and Developmental Immunology | Year: 2012

SLE is an autoimmune disease that is not uncommon in Malaysia. In contrast to Malays and Indians, the Chinese seem to be most affected. SLE is characterized by deficiency of body's immune response that leads to production of autoantibodies and failure of immune complex clearance. This minireview attempts to summarize the association of several candidate genes with risk for SLE in the Malaysian population and discuss the genetic heterogeneity that exists locally in Asians and in comparison with SLE in Caucasians. Several groups of researchers have been actively investigating genes that are associated with SLE susceptibility in the Malaysian population by screening possible reported candidate genes across the SLE patients and healthy controls. These candidate genes include MHC genes and genes encoding complement components, TNF, FcγR, T-cell receptors, and interleukins. However, most of the polymorphisms investigated in these genes did not show significant associations with susceptibility to SLE in the Malaysian scenario, except for those occurring in MHC genes and genes coding for TNF-α , IL-1β, IL-1RN, and IL-6. Copyright © 2012 Hwa Chia Chai et al.

Campbell L.,Flinders University | Brunger M.J.,Flinders University | Brunger M.J.,University of Malaya
Plasma Sources Science and Technology | Year: 2013

Electrons from the Sun, often accelerated by magnetospheric processes, produce low-density plasmas in the upper atmospheres of planets and their satellites. The secondary electrons can produce further ionization, dissociation and excitation, leading to enhancement of chemical reactions and light emission. Similar processes are driven by photoelectrons produced by sunlight in upper atmospheres during daytime. Sunlight and solar electrons drive the same processes in the atmospheres of comets. Thus for both understanding of planetary atmospheres and in predicting emissions for comparison with remote observations it is necessary to simulate the processes that produce upper atmosphere plasmas. In this review, we describe relevant models and their applications and address the importance of electron-impact excitation cross sections, towards gaining a quantitative understanding of the phenomena in question. © 2013 IOP Publishing Ltd.

Lee S.,Australian Institute for Plasma Focus Studies | Lee S.,INTI International University | Lee S.,University of Malaya
Journal of Fusion Energy | Year: 2014

The code couples the electrical circuit with plasma focus (PF) dynamics, thermodynamics and radiation. It is energy-, charge- and mass-consistent and accounts for the effects of transit times of small disturbances and plasma self-absorption. It has been used in design and interpretation of Mather-type PF experiments and as a complementary facility to provide diagnostic reference numbers in all gases. Information computed includes axial and radial dynamics, SXR emission characteristics and yield for various applications including microelectronics lithography and optimization of machines. Plasma focus neutron yield calculations, current and neutron yield limitations, deterioration of neutron scaling (neutron saturation), radiative collapse, speed-enhanced PF, current-stepped PF and extraction of diagnostic and anomalous resistance data from current signals have been studied using the code; which also produces reference numbers for fluence, flux and energy of deuteron beams and ion beams for all gases. There has been no pause in its continuous evolution in three decades so much so that the model code has no formal source reference except www.plasmafocus.net. This review presents, for the first time a comprehensive up-to-date version of the 5-phase model code. The equations of each phase are derived. Those of the first two phases are normalized to reveal important scaling parameters. The focus pinch phase is discussed with radiation-coupled dynamics necessitating the computation of radiation terms moderated by plasma self-absorption. Neutron and ion beam yields are computed. The 5-phase model code appears to be adequate for all Mather-type PF, lacking only in one aspect that for high inductance PF (termed Type 2) the measured current waveform contains an extended dip which cannot be fitted by the 5-phase code; necessitating an extended 6-phase code. This sixth phase (termed phase 4a) is dominated by anomalous resistance, providing a way to extract valuable data on anomalous resistivity from the current trace. © 2014 Springer Science+Business Media New York.

Saidur R.,University of Malaya
Renewable and Sustainable Energy Reviews | Year: 2010

The industrial sector is the largest users of energy around the world. Industrial motor uses a major fraction of total industrial energy uses. This paper describes a comprehensive literature review about electric motor energy analysis. This paper compiles latest literatures in terms of thesis (MS and PhD), journal articles, conference proceedings, web materials, reports, books, handbooks on electrical motor energy use, losses, efficiency, energy savings strategies. Different types of losses that occur in a motor have been identified and ways to overcome these losses explained. An energy audit that helps to identify motor energy wastages have been discussed extensively. As motors are the major energy users, different energy savings strategies such as use of high-efficient motor, variable speed drive (VSD), and capacitor bank to improve the power factor to reduce their energy uses have reviewed. Different policy measures (i.e. regulatory, voluntary and incentives based) to save motor energy use have been reviewed and presented in this paper. In this review, computer tools that can be used to analyze electric motors energy used has been discussed. Cost parameters to carry out economic analysis have been shown as well. Moreover, payback period for different energy savings strategies have been identified. © 2009 Elsevier Ltd. All rights reserved.

Kamkaew A.,Texas A&M University | Burgess K.,Texas A&M University | Burgess K.,University of Malaya
Chemical Communications | Year: 2015

Attempts to make a diamino disulfonic acid derivative of an aza-BODIPY showed it was difficult to add BF2 to a disulfonated azadipyrromethene, and sulfonation of an aza-BODIPY resulted in loss of the BF2 fragment. We conclude the electron-deficient character of aza-BODIPY dyes destabilizes them relative to BODIPY dyes. Consequently, sulfonation of the aza-BODIPY core is not a viable strategy to increase water solubility. This assertion was indirectly supported via stability studies of a BODIPY and an aza-BODIPY in aqueous media. To afford the desired compound type, an aza-BODIPY with two amino and two sulfonic acid groups was prepared via modification of the aryl substituents with cysteic acid. This journal is © The Royal Society of Chemistry 2015.

Muthukumar P.,Gandhigram Rural Institute | Balasubramaniam P.,Gandhigram Rural Institute | Ratnavelu K.,University of Malaya
Nonlinear Dynamics | Year: 2014

In this paper, a new fractional order stretch-twist-fold (STF) flow dynamical system is proposed. The stability analysis of the proposed system equilibria is accomplished and we establish that the system is exhibited chaos even for order less than 3. The active control method is applied to enquire the hybrid phase synchronization between two identical fractional order STF flow chaotic systems. These synchronized systems are applied to formulate an authenticated encryption scheme newly for message (text and image) recovery. It is widely applied in the field of secure communication. Numerical simulations are presented to validate the effectiveness of the proposed theory. © 2014 Springer Science+Business Media Dordrecht.

Bhandari A.K.,Indian Institute of Information Technology, Design and Manufacturing | Singh V.K.,Indian Institute of Information Technology, Design and Manufacturing | Kumar A.,Indian Institute of Information Technology, Design and Manufacturing | Singh G.K.,Indian Institute of Technology Roorkee | Singh G.K.,University of Malaya
Expert Systems with Applications | Year: 2014

The objective of image segmentation is to extract meaningful objects. A meaningful segmentation selects the proper threshold values to optimize a criterion using entropy. The conventional multilevel thresholding methods are efficient for bi-level thresholding. However, they are computationally expensive when extended to multilevel thresholding since they exhaustively search the optimal thresholds to optimize the objective functions. To overcome this problem, two successful swarm-intelligence-based global optimization algorithms, cuckoo search (CS) algorithm and wind driven optimization (WDO) for multilevel thresholding using Kapur's entropy has been employed. For this purpose, best solution as fitness function is achieved through CS and WDO algorithm using Kapur's entropy for optimal multilevel thresholding. A new approach of CS and WDO algorithm is used for selection of optimal threshold value. This algorithm is used to obtain the best solution or best fitness value from the initial random threshold values, and to evaluate the quality of a solution, correlation function is used. Experimental results have been examined on standard set of satellite images using various numbers of thresholds. The results based on Kapur's entropy reveal that CS, ELR-CS and WDO method can be accurately and efficiently used in multilevel thresholding problem. © 2013 Elsevier B.V. All rights reserved.

This study applies the bounds testing approach, error-correction modelling and persistence profile to analyse the dynamic relationship between real tourism receipts, real income and real exchange rates in Malaysia. The present study covers the annual sample period from 1974 to 2009. The results reveal that a long-run relationship exists between the variables. In the short run, this study finds no Granger causality between real tourism receipts and real income, whereas there is bidirectional causality in the long-run. Moreover, we also find unidirectional causality running from real exchange rates to real tourism receipts and real income in both short- and long-run. © 2012 John Wiley & Sons, Ltd.

Halawa E.,Charles Darwin University | GhaffarianHoseini A.,University of Malaya | Hin Wa Li D.,City University of Hong Kong
Renewable Energy | Year: 2014

In regions where solar energy is abundant, solar energy can play a vital role in attaining energy sustainability. Sizing solar energy systems requires the availability of solar radiation data on horizontal surface which can then be used to calculate solar radiation intensity on any tilted surface using appropriate conversion factors or formula. In many parts of the world, especially in developing countries, such data is not readily available. Many researchers have found that monthly average daily value of global solar radiation on horizontal surface can be estimated when meteorological parameters such as duration of sunshine, number of rainy days, relative humidity, etc. are available. Many empirical correlations have been developed based on this approach. The development of such a correlation has been made possible through the availability of solar and other meteorological data required for their validation. This paper presents a review on the existing empirical correlations and critically looks at the practicality of such correlations. This raises the question on the appropriateness of the past and present approaches adopted by researchers in this field. The paper also discusses various related aspects and proposes new directions for future research. © 2014 Elsevier Ltd.

Zhan S.-Z.,Shantou University | Li M.,Shantou University | Ng S.W.,University of Malaya | Ng S.W.,King Abdulaziz University | Li D.,Shantou University
Chemistry - A European Journal | Year: 2013

Two classical copper(I)-cluster-based luminophores, namely, Cu 4I4 and [Cu3Pz3]2 (Pz=pyrazolate), are immobilized in a supramolecular system through the formation of metal-organic framework (MOF) materials. This series of luminescent MOF materials, namely, [Cu4I4(NH3)Cu 3(L1)3]n, [Cu4I4(NH 2CH3)Cu3(L1)3]n, and [Cu4I4Cu3(L2)3]n (L1=3-(4-pyridyl)-5-(p-tolyl)pyrazolate; L2=3-(4-pyridyl)-5-(2,4-dimethylphenyl) pyrazolate), exhibit diverse thermochromism attributed to the relative functioning efficacy of the two coordination luminophores. Such an intriguing chemopalette effect is regulated by the different supramolecular microenvironments between the two-dimensional layers of these MOFs, and in particular, by the fine-tuned Cu-Cu distances in the excimeric [Cu 3Pz3]2 luminophore. The structure-property elucidation of the thermochromic behavior allows one to understand these optical materials with unusual dual-emissive properties. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zamani-Farahani H.,University of Malaya | Henderson J.C.,Nanyang Technological University
International Journal of Tourism Research | Year: 2010

This paper is concerned with the effects of state religion on tourism development in Muslim countries with particular reference to Iran and Saudi Arabia. Aspects of the relationship between Islam and tourism are investigated overall and issues of tourism policies, management and marketing and community involvement within the context of the two cases are discussed. The distinctive circumstances prevailing in Iran and Saudi Arabia are suggested, but more general insights are also presented into the interactions between and management of tourism and Islam. Copyright © 2009 John Wiley & Sons, Ltd.

Ishaque K.,University of Technology Malaysia | Ishaque K.,Karachi Institute of Economics & Technology | Salam Z.,University of Technology Malaysia | Amjad M.,University of Technology Malaysia | Mekhilef S.,University of Malaya
IEEE Transactions on Power Electronics | Year: 2012

This paper proposes an improved maximum power point tracking (MPPT) method for the photovoltaic (PV) system using a modified particle swarm optimization (PSO) algorithm. The main advantage of the method is the reduction of the steady-state oscillation (to practically zero) once the maximum power point (MPP) is located. Furthermore, the proposed method has the ability to track the MPP for the extreme environmental condition, e.g., large fluctuations of insolation and partial shading condition. The algorithm is simple and can be computed very rapidly; thus, its implementation using a low-cost microcontroller is possible. To evaluate the effectiveness of the proposed method, MATLAB simulations are carried out under very challenging conditions, namely step changes in irradiance, step changes in load, and partial shading of the PV array. Its performance is compared with the conventional Hill Climbing (HC) method. Finally, an experimental rig that comprises of a buck-boost converter fed by a custom-designed solar array simulator is set up to emulate the simulation. The software development is carried out in the Dspace 1104 environment using a TMS320F240 digital signal processor. The superiority of the proposed method over the HC in terms of tracking speed and steady-state oscillations is highlighted by simulation and experimental results. © 2012 IEEE.

Hamzah B.A.,University of Malaya
Ocean Development and International Law | Year: 2010

This article examines the development of Malaysia's policy toward the Southern Ocean since 1983. Malaysia appears set to sign the 1959 Antarctic Treaty. The signing of the Treaty will close a chapter in the North-South divide on the question ofAntarctica at the United Nations. It will also signal a new face or orientation in Malaysia's foreign policy toward the Southern Ocean under the new regime led by Prime Minister Dato Seri Najib Razak. © Taylor & Francis Group, LLC.

Nejadkoorki F.,University of Yazd | Baroutian S.,University of Malaya
International Journal of Environmental Research | Year: 2012

Life style and life expectancy of inhabitants have been affected by the increase of particulate matter 10 micrometers or less in diameter (PM 10) in cities and this is why maximum PM 10 concentrations have received extensive attention. An early notice system for PM 10 concentrations necessitates an accurate forecasting of the pollutant. In the current study an Artificial Neural Network was used to estimate maximum PM 10 concentrations 24-h ahead in Tehran. Meteorological and gaseous pollutants from different air quality monitoring stations and meteorological sites were input into the model. Feed-forward back propagation neural network was applied with the hyperbolic tangent sigmoid activation function and the Levenberg-Marquardt optimization method. Results revealed that forecasting PM 10 in all sites appeared to be promising with an index of agreement of up to 0.83. It was also demonstrated that Artificial Neural Networks can prioritize and rank the performance of individual monitoring sites in the air quality monitoring network.

Reza A.W.,University of Malaya | Eswaran C.,Multimedia University
Journal of Medical Systems | Year: 2011

The increasing number of diabetic retinopathy (DR) cases world wide demands the development of an automated decision support system for quick and cost-effective screening of DR. We present an automatic screening system for detecting the early stage of DR, which is known as non-proliferative diabetic retinopathy (NPDR). The proposed system involves processing of fundus images for extraction of abnormal signs, such as hard exudates, cotton wool spots, and large plaque of hard exudates. A rule based classifier is used for classifying the DR into two classes, namely, normal and abnormal. The abnormal NPDR is further classified into three levels, namely, mild, moderate, and severe. To evaluate the performance of the proposed decision support framework, the algorithms have been tested on the images of STARE database. The results obtained from this study show that the proposed system can detect the bright lesions with an average accuracy of about 97%. The study further shows promising results in classifying the bright lesions correctly according to NPDR severity levels. © 2009 Springer Science+Business Media, LLC.