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George Town, Malaysia

Universiti Sains Malaysia is a public university in Malaysia. There are three campuses: one on the island of Penang , one in Kelantan , and one in Nibong Tebal . There is offshore collaboration with KLE University, India offering the Doctor of Medicine undergraduate degree. USM plans to open a Global Campus located at Kuala Lumpur Education City . With around 28,300 postgraduate and undergraduate students in 2009, USM is one of the biggest universities in terms of enrollment in Malaysia. The number of lecturers is about 1,479, which leads to a student-lecturer ratio of around 19:1. Wikipedia.

Adzitey F.,Universiti Sains Malaysia
International Food Research Journal | Year: 2011

Animal handling is a growing issue of concern in many countries around the world. Developed countries in particular show keen interest in the way animals are handled throughout production to processing. In such countries animal welfare is increasingly becoming a primary matter in the process of keeping animals either as pets or for food and at homes or on farms. Not only are they protecting the rights of these animals but poor animal handling has adverse effects on the animal, carcass and meat quality. Poor quality animal and meat will have poor processing properties, functional quality, eating quality, and more likely to be unaccepted by consumers. Lesser attention has been paid by most developing countries on this issue. By this review, it is expected that developing countries also take interest in proper pre-slaughter handling of animals due to their beneficial effect on meat and carcass qualities. This review highlights the factors to consider in handling animals and their effect on meat and carcass quality. © 2011.

Al-mulali U.,Universiti Sains Malaysia
Energy | Year: 2011

This study examines the impact of oil consumption on the economic growth of the MENA countries during the period 1980-2009. The panel model is employed in this study. Based on the cointegration test results, it was found that CO 2 emission, and oil consumption has a long run relationship with economic growth. Moreover, there is also a bi-directional Granger causality between oil consumption, CO 2 emission and economic growth in both the short run and the long run. The results of this study show clearly that oil consumption plays an important role in the economic growth of the MENA countries. © 2011 Elsevier Ltd.

Khaironizam M.Z.,Universiti Sains Malaysia | Armbruster J.W.,Auburn University
Zootaxa | Year: 2015

Meristic, morphometric and distributional patterns of cyprinid fishes of the genus Neolissochilus found in Peninsular Malaysia are presented. Based on the current concept of Neolissochilus, only two species are present: N. soroides and N. hendersoni. Neolissochilus hendersoni differs from N. soroides by having lower scale and gill raker counts. Neolissochilus soroides has three mouth types (normal with a rounded snout, snout with a truncate edge, and lobe with a comparatively thick lower lip). A PCA of log-transformed measurements did not reveal significant differences between N. hendersoni and N. soroides, or between any of the morphotypes of N. soroides; however, a CVA of log-transformed measurements successfully classified 87.1% of all specimens. Removing body size by running a CVA on all of the principal components except PC1 (which was correlated with length) only slightly decreased the successful classification rate to 86.1%. Differences in morphometrics were as great between the three morphotypes of N. soroides as between any of the morphotypes and N. hendersoni suggesting that the morphotypes should be examined in greater detail with genetic tools. The PCA of morphometrics revealed separate clouds for N. hendersoni and N. soroides, but no differences between the N. soroides morphotypes. This study revealed that N. hendersoni is recorded for the first time in the mainland area of Peninsular Malaysia. Other nominal species of Neolissochilus reported to occur in the river systems of Peninsular Malaysia are discussed. Lissochilus tweediei Herre in Herre & Myers 1937 and Tor soro Bishop 1973 are synonyms of Neolissochilus soroides. Copyright © 2015 Magnolia Press.

Jawaid M.,University of Technology Malaysia | Abdul Khalil H.P.S.,Universiti Sains Malaysia | Hassan A.,University of Technology Malaysia | Dungani R.,Bandung Institute of Technology | Hadiyane A.,Bandung Institute of Technology
Composites Part B: Engineering | Year: 2013

Hybrid composites prepared by hand lay-up technique by reinforcing jute and oil palm fibres with epoxy matrix. The tensile properties of hybrid composites were found to increase substantially with increasing jute fibres loading as compared to oil palm-epoxy composite. The nature of fibre/matrix interface was examined through scanning electron microscopy of tensile fracture samples. Addition of jute fibres to oil palm composite increases the storage modulus while damping factor shifts towards higher temperature region. Cole-Cole analysis was made to understand the phase behaviour of the composite samples. The hybrid composite with oil palm:jute (1:4) showed maximum damping behaviour and highest tensile properties. The overall use of hybrid system was found to be effective in increasing tensile and dynamic mechanical properties of the oil palm-epoxy composite probably due to the enhanced fibre/matrix interface bonding. The potential applications of the oil palm based hybrid composites in automobiles and building industry are going to increase in near future. © 2012 Elsevier Ltd. All rights reserved.

Lee Y.Y.,University of Glasgow | Lee Y.Y.,Universiti Sains Malaysia | Derakhshan M.H.,University of Glasgow
Archives of Iranian Medicine | Year: 2013

Effective prevention and early diagnostic strategies are the most important public health interventions in gastric cancer, which remains a common malignancy worldwide. Preventive strategies require identification and understanding of environmental risk factors that lead to carcinogenesis. Helicobacter pylori (H. pylori) is the primary carcinogen as this ancient bacterium has a complex ability to interact with its human host. Smoking and salt are strong independent risk factors for gastric cancer whereas alcohol is only a risk when it is heavily consumed. Red meat and high fat increase the risk of gastric cancer however fresh fruits, vegetables (allium family) and certain micronutrients (selenium, vitamin C) reduce the risk, with evidence lacking for fish, coffee and tea. Foods that inhibit H. pylori viability, colonization and infection may reduce cancer risk. Obesity is increasingly recognized as a contributory factor in gastric cardia carcinogenesis. Therefore, modest daily physical activities can be protective against cancer. Foundry workers are at risk for developing gastric cancer with dust iron being an important cause. Other risk factors include Epstein-Barr virus (EBV), possibly JC virus and radiation but the effects of these are likely to remain small.

Mohamad Haafiz M.K.,University of Technology Malaysia | Mohamad Haafiz M.K.,Universiti Sains Malaysia | Hassan A.,University of Technology Malaysia | Jawaid M.,University Putra Malaysia
Carbohydrate Polymers | Year: 2013

In this work, we successfully isolated microcrystalline cellulose (MCC) from oil palm empty fruit bunch (OPEFB) fiber-total chlorine free (TCF) pulp using acid hydrolysis method. TCF pulp bleaching carried out using an oxygen-ozone-hydrogen peroxide bleaching sequence. Fourier transform infrared (FT-IR) spectroscopy indicates that acid hydrolysis does not affect the chemical structure of the cellulosic fragments. The morphology of the hydrolyzed MCC was investigated using scanning electron microscopy (SEM), showing a compact structure and a rough surface. Furthermore, atomic force microscopy (AFM) image of the surface indicates the presence of spherical features. X-ray diffraction (XRD) shows that the MCC produced is a cellulose-I polymorph, with 87% crystallinity. The MCC obtained from OPEFB-pulp is shown to have a good thermal stability. The potential for a range of applications such as green nano biocomposites reinforced with this form of MCC and pharmaceutical tableting material is discussed. © 2013 Elsevier Ltd.

Balaji S.,Thiagarajar College of Engineering | Vasuki R.,Thiagarajar College of Engineering | Mutharasu D.,Universiti Sains Malaysia
Journal of Alloys and Compounds | Year: 2013

The SnO2/NiFe2O4 nanocomposite samples with varying concentration of SnO2 such as 5 wt.% and 10 wt.% were synthesized via urea assisted combustion synthesis. The kinetics of the combustion reactions were studied using thermo gravimetry analysis and from which the compound formation temperature of all the samples were observed to be below 400 °C. From the morphological analysis the grain size of NiFe 2O4, 5 wt.% SnO2/NiFe2O4 and 10 wt.% SnO2/NiFe2O4 samples were observed to be around 1.7, 2.3 and 3.5 μm. The chrono potentiometry analyses of the samples were performed against lithium metal electrode. The capacity retention was found to be higher for composite with 10 wt.% SnO2. The discharge capacity of 10 wt.% SnO2 sample with respect to Li metal and LiMn2O4 electrode was observed to be around 980 mA h/g and 138 mA h/g respectively. © 2012 Elsevier B.V. All rights reserved.

Sankar D.S.,Universiti Sains Malaysia
International Journal of Nonlinear Sciences and Numerical Simulation | Year: 2012

The peristaltic transport of Casson fluid in a channel and also in an inclined tube is analyzed mathematically, using long wavelength approximation and low Reynolds number assumption. The expressions for the velocity, stream function, flow rate, pressure rise and frictional force at the wall are obtained. It is found that the pressure rise decreases with the increase of the time mean flow rate and angle of inclination and increases with the increase of stress ratio and amplitude ratio. It is also noticed that the frictional force increases with the increase of the stress ratio and decreases with the increase of the angle of inclination. The estimates of the increase in the pressure rise are higher in channel flow compared to that of the inclined tube flow and the estimates of the increase in the frictional force are higher in inclined tube flow compared to that of the channel flow. Copyright © 2012 De Gruyter.

Nauheimer L.,Ludwig Maximilians University of Munich | Boyce P.C.,Universiti Sains Malaysia | Renner S.S.,Ludwig Maximilians University of Munich
Molecular Phylogenetics and Evolution | Year: 2012

Alocasia comprises over 113 species of rainforest understorey plants in Southeast Asia, the Malesian region, and Australia. Several species, including giant taro, Alocasia macrorrhizos, and Chinese taro, Alocasia cucullata, are important food plants or ornamentals. We investigated the biogeography of this genus using plastid and nuclear DNA sequences (5200 nucleotides) from 78 accessions representing 71 species, plus 25 species representing 16 genera of the Pistia clade to which Alocasia belongs. Divergence times were inferred under strict and relaxed clock models, and ancestral areas with Bayesian and maximum likelihood approaches. Alocasia is monophyletic and sister to Colocasia gigantea from the SE Asian mainland, whereas the type species of Colocasia groups with Steudnera and Remusatia, requiring taxonomic realignments. Nuclear and plastid trees show topological conflict, with the nuclear tree reflecting morphological similarities, the plastid tree species' geographic proximity, suggesting chloroplast capture. The ancestor of Alocasia diverged from its mainland sister group c. 24 million years ago, and Borneo then played a central role in the expansion of Alocasia: 11-13 of 18-19 inferred dispersal events originated on Borneo. The Philippines were reached from Borneo 4-5. times in the Late Miocene and Early Pliocene, and the Asian mainland 6-7. times in the Pliocene. Domesticated giant taro originated on the Philippines, Chinese taro on the Asian mainland. © 2011 Elsevier Inc.

Wong W.P.,Universiti Sains Malaysia | Jaruphongsa W.,Chulalongkorn University | Lee L.H.,National University of Singapore
IEEE Transactions on Automatic Control | Year: 2011

We analyze how to allocate the budget for data collection effectively when data envelopment analysis (DEA) is used for predicting the efficiency. We formulate this problem under a Bayesian framework and propose two heuristics algorithms, i.e., a gradient-based algorithm and a hybrid GA algorithm to solve this optimization problem. Our results indicate that effective allocation of budget for data collection can greatly reduce the overall data collection effort in comparison with a uniform budget allocation. © 2006 IEEE.

Jayaprakash P.T.,Universiti Sains Malaysia
Forensic Science International | Year: 2015

Establishing identification during skull-photo superimposition relies on correlating the salient morphological features of an unidentified skull with those of a face-image of a suspected dead individual using image overlay processes. Technical progression in the process of overlay has included the incorporation of video cameras, image-mixing devices and software that enables real-time vision-mixing. Conceptual transitions occur in the superimposition methods that involve 'life-size' images, that achieve orientation of the skull to the posture of the face in the photograph and that assess the extent of match. A recent report on the reliability of identification using the superimposition method adopted the currently prevalent methods and suggested an increased rate of failures when skulls were compared with related and unrelated face images. The reported reduction in the reliability of the superimposition method prompted a review of the transition in the concepts that are involved in skull-photo superimposition. The prevalent popular methods for visualizing the superimposed images at less than 'life-size', overlaying skull-face images by relying on the cranial and facial landmarks in the frontal plane when orienting the skull for matching and evaluating the match on a morphological basis by relying on mix-mode alone are the major departures in the methodology that may have reduced the identification reliability. The need to reassess the reliability of the method that incorporates the concepts which have been considered appropriate by the practitioners is stressed. © 2014 Elsevier Ireland Ltd.

Lee L.K.,Universiti Sains Malaysia
Clinical biochemistry | Year: 2014

Infertility is a worldwide reproductive health problem which affects approximately 15% of couples, with male factor infertility dominating nearly 50% of the affected population. The nature of the phenomenon is underscored by a complex array of transcriptomic, proteomic and metabolic differences which interact in unknown ways. Many causes of male factor infertility are still defined as idiopathic, and most diagnosis tends to be more descriptive rather than specific. As such, the emergence of novel transcriptomic and metabolomic studies may hold the key to more accurately diagnose and treat male factor infertility. This paper provides the most recent evidence underlying the role of transcriptomic and metabolomic analysis in the management of male infertility. A summary of the current knowledge and new discovery of noninvasive, highly sensitive and specific biomarkers which allow the expansion of this area is outlined. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Ali R.,University Malaysia Perlis | Daut I.,University Malaysia Perlis | Taib S.,Universiti Sains Malaysia
Renewable and Sustainable Energy Reviews | Year: 2012

As the electricity demand is affected by population growth, Malaysia towards an industrialized nation is considering the options for future energy sources for its power generation. Besides the conventional four-fuel mix, the five-fuel mix strategy under several national policies are introduced to diversify and expanding the resources to incorporate renewable energy and nuclear. In view of Malaysia will become a net energy importer by 2020, the increase in alternative energy shares at least will provide stable energy security, more economical and greener environment. In this paper, present and future energy sources are discussed to emphasis on the constraints and barriers facing Malaysia towards energy security and sustainability. Several preferences on future energy sources are under serious consideration where renewable energy (RE) is becoming one of the popular choices as Malaysia recognizes the potential of RE as sustainable and greener option. © 2012 Elsevier Ltd. All right reserved.

Rahman I.A.,Universiti Sains Malaysia | Padavettan V.,Intel Corporation
Journal of Nanomaterials | Year: 2012

Application of silica nanoparticles as fillers in the preparation of nanocomposite of polymers has drawn much attention, due to the increased demand for new materials with improved thermal, mechanical, physical, and chemical properties. Recent developments in the synthesis of monodispersed, narrow-size distribution of nanoparticles by sol-gel method provide significant boost to development of silica-polymer nanocomposites. This paper is written by emphasizing on the synthesis of silica nanoparticles, characterization on size-dependent properties, and surface modification for the preparation of homogeneous nanocomposites, generally by sol-gel technique. The effect of nanosilica on the properties of various types of silica-polymer composites is also summarized. © Copyright 2012 Ismail Ab Rahman and Vejayakumaran Padavettan.

Baioumy H.M.,Universiti Sains Malaysia
Applied Clay Science | Year: 2014

Titanium (Ti) is a major impurity in the economic Carboniferous and Cretaceous sedimentary kaolin deposits in Egypt. The current study clarifies the distribution of Ti and its modes of occurrence in these deposits through petrographic, mineralogical, and geochemical investigations. It is found that Ti is present as an independent mineral phase rather than in the crystal structure of kaolinite. Ti occurs mainly as uniform very fine-grained and rounded anatase crystals in pockets within the kaolin mass of all deposits. Traces of rutile, leucoxene and ilmenite are present in the sand fractions. Average anatase content ranges between 1.4% and 3%. Cretaceous kaolin deposits show a homogeneous distribution of anatase regardless of the location (1.8 and 2.8%), while Carboniferous deposits are heterogeneous with the highest anatase content in the Abu Natash deposit (3%) and the lowest (1.4%) in the Khaboba deposit. The positive correlations between TiO2 and some trace elements such Cr, Nb and Zr in the clay fractions, where anatase is the only Ti-bearing mineral, suggest the occurrence of most of such elements in the anatase structure.The occurrence of anatase as uniform very fine-grained crystals as pockets within the kaolin mass, together with the presence of ilmenite and/or leucoxene in the sand fractions of the studied kaolin samples suggests an authigenic origin for the anatase as a result of post-depositional alteration of ilmenite precursor to leucoxene. The positive correlations between TiO2 and trace element contents probably support this assumption. The higher trace element contents in the anatase from different deposits compared to the associated leucoxene and ilmenite are considered to result from relative enrichment of the immobile trace elements during the alteration of ilmenite and leucoxene to anatase. © 2014 Elsevier B.V.

Jayaprakash P.T.,Universiti Sains Malaysia
Forensic Science International | Year: 2013

Uniqueness being unprovable, it has recently been argued that individualization in forensic science is irrelevant and, probability, as applied for DNA profiles, should be applied for all identifications. Critiques against uniqueness have omitted physical matching, a realistic and tangible individualization that supports uniqueness. Describing case examples illustrating pattern matches including physical matching, it is indicated that individualizations are practically relevant for forensic science as they establish facts on a definitive basis providing firm leads benefitting criminal investigation. As a tenet of forensic identification, uniqueness forms a fundamental paradigm relevant for individualization. Evidence on the indeterministic and stochastic causal pathways of characteristics in patterns available in the related fields of science sufficiently supports the proposition of uniqueness. Characteristics involved in physical matching and matching achieved in patterned evidence existing in the state of nature are not events amenable for counting; instead these are ensemble of visible units occupying the entire pattern area stretching the probability of re-occurrence of a verisimilitude pattern into infinity offering epistemic support to uniqueness. Observational methods are as respectable as instrumental or statistical methods since they are capable of generating results that are tangible and obviously valid as in physical matching. Applying the probabilistic interpretation used for DNA profiles to the other patterns would be unbefitting since these two are disparate, the causal pathways of the events, the loci, in the manipulated DNA profiles being determinable. While uniqueness enables individualizations, it does not vouch for eliminating errors. Instead of dismissing uniqueness and individualization, accepting errors as human or system failures and seeking remedial measures would benefit forensic science practice and criminal investigation. © 2013 Elsevier Ireland Ltd.

Jadin M.S.,Universiti Malaysia Pahang | Taib S.,Universiti Sains Malaysia
Infrared Physics and Technology | Year: 2012

Infrared thermography (IRT) has gained more attention and become an interesting method in electrical preventive maintenance due to its high precision and sensitivity imaging characteristics. This paper provides a review of the application of IRT for diagnosing electrical equipment, including their thermal anomalies and methods of measurement. Improvement of the inspection techniques is highlighted in order to investigate the reliability of electrical equipments due to the effect of the environmental factors and equipment condition. Factors related to the target equipment and the inspection tool together with their characteristics is also presented. Due to the complex analysis, various automatic diagnostic systems are proposed for faster and more accurate analysis. Typical engineering solutions using recent technologies are reviewed which could be used to improve the quality of IRT inspection. © 2012 Elsevier B.V. All rights reserved.

Ahmad Z.,Indian Institute of Technology Roorkee | Azamathulla H.,Universiti Sains Malaysia
Journal of Hydrology | Year: 2012

Free overfall at the abrupt end of a channel offers a simple method for measurement of discharge from a single measurement of depth of flow at the brink. The theoretical procedure applied to compute discharge over a weir is applied to the free overfall to obtain end-depth-discharge relationship for subcritical and super critical flows. Pressure distribution at the brink, which is assumed a quadratic parabola, is incorporated in the analysis. A closed form equation for discharge in terms of end depth for subcritical flows was proposed and validated earlier with available experimental data in place of a derived implicit complex equation. Direct solution for discharge for known end depth is provided in the graphical form for super critical flows. Verification of this solution with available experimental data revealed that comparison is not as good as it is observed in subcritical flows. The difference in computed and observed results is attributed to the greater effect of streamline curvature and estimation of pressure factor in the supercritical flows. © 2012 Elsevier B.V.

Rahman Z.A.,Universiti Sains Malaysia
Journal of oral science | Year: 2010

The aim of the present study was to assess the levels of salivary cortisol, tumor necrosis factor-alpha (TNF-alpha) and nitric oxide (NO) before, during and after acute exercise. Acute exercise was induced using a standard treadmill test with Bruce protocol in ten physically active male participants. Unstimulated saliva was collected before, during and after exercise. The levels of salivary cortisol and TNF-alpha were assessed by enzyme immunoassays. Salivary NO was determined by the Griess reagent. The results showed that both salivary cortisol and TNF-alpha increased and peaked at 14 min during exercise and then decreased. The levels of NO were increased up to 1 h after exercise and subsequently lowered after 24 h. The results of the present study suggest that acute exercise may induce high levels of salivary cortisol, TNF-alpha and NO.

Azamathulla H.,Universiti Sains Malaysia | Ahmad Z.,Indian Institute of Technology Roorkee
Journal of Hydrology | Year: 2012

This study presents gene-expression programming (GEP), which is an extension of genetic programming (GP), as an alternative approach to predict the transverse mixing coefficient in open channel flows. Laboratory data were collected in the present study and also from the literature for the transverse mixing coefficient covering wide range of flow conditions. These data were used for the development and testing of the proposed method. A functional relation for the estimation of transverse mixing coefficient has been developed using GEP. The proposed GEP approach produced satisfactory results compared to the existing predictors for the transverse mixing coefficient. © 2012 Elsevier B.V..

Lean H.H.,Universiti Sains Malaysia | McAleer M.,Erasmus University Rotterdam | Wong W.-K.,Hong Kong Baptist University
Energy Economics | Year: 2010

This paper examines the market efficiency of oil spot and futures prices by using both mean-variance (MV) and stochastic dominance (SD) approaches. Based on the West Texas Intermediate crude oil data for the sample period 1989-2008, we find no evidence of any MV and SD relationships between oil spot and futures indices. This infers that there is no arbitrage opportunity between these two markets, spot and futures do not dominate one another, investors are indifferent to investing spot or futures, and the spot and futures oil markets are efficient and rational. The empirical findings are robust to each sub-period before and after the crises for different crises, and also to portfolio diversification. © 2010 Elsevier B.V.

Gui M.M.,University of Selangor | Chai S.-P.,University of Selangor | Xu B.-Q.,Tsinghua University | Mohamed A.R.,Universiti Sains Malaysia
Solar Energy Materials and Solar Cells | Year: 2014

This work demonstrates the synthesis of MWCNT/TiO2 core-shell nanocomposites and their application for photocatalytic reduction of CO 2 under visible light irradiation. MWCNT/TiO2 core-shell nanocomposites were obtained from a newly developed coating approach. UV-vis analysis revealed that the photoactivity of the nanocomposites in the visible light range was significantly enhanced with the absorption edge extended to the visible light region (>400 nm). The XRD and Raman analysis indicated that the TiO2 shell layer was composed of anatase TiO2 nanocrystallite prevailing grew along the (1 0 1) direction. The MWCNT/TiO 2 core-shell nanocomposites exhibited conversion of CO2 into methane in a continuous process under a low power visible light irradiation at atmospheric pressure. The highest methane yield of ca. 0.17 μmol/g-catalyst/h was recorded at the 6th hour of irradiation time. © 2013 Elsevier B.V. All rights reserved.

Suki N.M.,Universiti Malaysia Sabah | Ramayah T.,Universiti Sains Malaysia
Interdisciplinary Journal of Information, Knowledge, and Management | Year: 2010

This paper identifies the factors that determine users' acceptance of e-Government services and its causal relationships using a theoretical model based on the Technology Acceptance Model. Data relating to the constructs were collected from 200 respondents in Malaysia and subjected to Structural Equation Modeling analysis. The proposed model fits the data well. Results indicate that the important determinants of user acceptance of the e-Government services are perceived usefulness, ease of use, compatibility, interpersonal influence, external influence, self efficacy, facilitating conditions, attitude, subjective norms, perceived behavioral control, and intention to use e-Government services/system. Finally, implications and recommendations of these finding are discussed.

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.

Vicknasingam B.,Universiti Sains Malaysia | Mazlan M.,Substance Abuse Research Center | Schottenfeld R.S.,Yale University | Chawarski M.C.,Yale University
Drug and Alcohol Dependence | Year: 2010

Background: Buprenorphine maintenance is efficacious for treating opioid dependence, but problems with diversion and misuse of buprenorphine (BUP) may limit its acceptability and dissemination. The buprenorphine/naloxone combination tablet (BNX) was developed to reduce potential problems with diversion and abuse. This paper provides data regarding the characteristics of BUP injection drug users in Malaysia and preliminary data regarding the impact of withdrawing BUP and introducing BNX. BUP was introduced in 2002 and subsequently withdrawn from the Malaysian market in 2006. BNX was introduced in 2007. Methods: A two wave survey of BUP IDUs was conducted shortly prior to BUP withdrawal from the Malaysian market (n=276) and six months after BNX was introduced (n=204). Six focus groups with BUP and/or BNX IDUs were also conducted shortly before the second wave. Results: In addition to current BUP or BNX IDU, 96% of first wave participants and 97% second wave participants reported lifetime heroin IDU preceding the onset of their BUP/BNX IDU. Additionally, 58% of first and 64% of second wave survey participants reported current heroin IDU. Benzodiazepine abuse, often injected with BUP, was reported in both the surveys. Focus group participants reported that BNX was not as desirable as BUP, nonetheless, the results of the second wave survey suggest a continuing widespread BNX IDU, at least in Kuala Lumpur. Conclusions: In Malaysia, BUP and BNX IDU occur among heroin IDUs. The introduction of BNX and withdrawal of BUP may have helped to reduce, but did not eliminate the problems with diversion and abuse. © 2010 Elsevier Ireland Ltd.

Rohni A.M.,Northern University of Malaysia | Ahmad S.,Universiti Sains Malaysia | Pop I.,Technical University of Cluj Napoca
International Journal of Heat and Mass Transfer | Year: 2012

The unsteady flow over a continuously shrinking surface with wall mass suction in a water based nanofluid containing different type of nanoparticles: Cu, Al 2O 3 and TiO 2 is numerically studied. Similarity equations are obtained through the application of similarity transformation techniques. The shooting method is used to solve the similarity equations for different values of the wall mass suction, the unsteadiness and the nanoparticle volume fraction parameters. The results of skin friction coefficient f″(0) and heat transfer rate -θ′(0) are presented in tables and graphs. It is found that dual solution exists for a certain range of wall mass suction s, volume fraction and unsteadiness parameters A. The results of velocity and temperature profiles are also presented. It is seen that two values of boundary layer thickness η ∞ are obtained, which gives two different velocity and temperature profiles that satisfy the boundary conditions. It is also found that the nanoparticle volume fraction parameter and types of nanofluid play an important role to significantly determine the flow behaviour. © 2011 Elsevier Ltd. All rights reserved.

Daud W.R.W.,Universiti Sains Malaysia | Law K.-N.,University of Quebec at Trois - Rivieres
BioResources | Year: 2011

This paper reviews the physical and chemical characteristics of fibers from the stem, fronds, and empty fruit bunches of oil palm tree in relation to their papermaking properties. Challenges regarding the use of this nonwood material for papermaking are raised, and possible solutions to them are given. A vision for the complete utilization of oil palm biomass is also outlined.

Tay K.M.,University Malaysia Sarawak | Lim C.P.,Universiti Sains Malaysia
International Journal of Uncertainty, Fuzziness and Knowlege-Based Systems | Year: 2011

An important and difficult issue in designing a Fuzzy Inference System (FIS) is the specification of fuzzy sets and fuzzy rules. In this paper, two useful qualitative properties of the FIS model, i.e., the monotonicity and sub-additivity properties, are studied. The monotonic sufficient conditions of the FIS model with Gaussian membership functions are further analyzed. The aim is to incorporate the sufficient conditions into the FIS modeling process, which serves as a simple (which can be easily understood by domain users), easy-to-use (which can be easily applied to or can be a part of the FIS model), and yet reliable (which has a sound mathematical foundation) method to preserve the monotonicity property of the FIS model. Another aim of this paper is to demonstrate how these additional qualitative information can be exploited and extended to be part of the FIS designing procedure (i.e., for fuzzy sets and fuzzy rules design) via the sufficient conditions (which act as a set of useful governing equations for designing the FIS model). The proposed approach is able to avoid the "trial and error" procedure in obtaining a monotonic FIS model. To assess the applicability of the proposed approach, two practical problems are examined. The first is an FIS-based model for water level control, while the second is an FIS-based Risk Priority Number (RPN) model in Failure Mode and Effect Analysis (FMEA). To further illustrate the importance of the sufficient conditions as the governing equations, an analysis on the consequences of violating the sufficient conditions of the FIS-based RPN model is presented. © 2011 World Scientific Publishing Company.

Chong H.L.H.,Universiti Malaysia Sabah | Chia P.S.,Universiti Malaysia Sabah | Ahmad M.N.,Universiti Sains Malaysia
Bioresource Technology | Year: 2013

Oil palm shell, a waste from palm oil industry, was cleaned and utilized as adsorbent. Its particle size distribution gave the uniformity coefficient of approximately two indicating that it can be used as filter bed media for continuous operation without resting. Its measured pHpzc of 4.1 is below the common pH of constructed wetland water body suggesting positive adsorption for heavy metal. The effect of various parameters on its adsorption was studied via batch experiments. The adsorption of Cu(II) and Pb(II) ions by oil palm shell showed a slightly better fit with the Freundlich compared to Langmuir. Its monolayer adsorption capacities were found to be 1.756 and 3.390mg/g for Cu(II) and Pb(II), respectively. High correlation coefficient of over 0.99 given by the pseudo-second-order model suggests that the rate limiting factor may be chemisorption. These findings suggest its potential application as constructed wetland media for the removal of heavy metal. © 2012 Elsevier Ltd.

Mehat N.M.,Kolej Kemahiran Tinggi MARA | Kamaruddin S.,Universiti Sains Malaysia
Materials and Manufacturing Processes | Year: 2011

The growing amount of plastic parts produced nowadays makes the search for alternatives in recycling and the further use of these nonbiodegradable materials imperative. The degradation of the mechanical properties of recycled plastic products poses the primary limitation for the usage of recycled plastic. One of the foremost causes of mechanical property degradation is variation in processing parameters. An appropriate optimization method that effectively controls all influential processing parameters during manufacturing is therefore critical. This study investigates the effects of injection molding parameters on the mechanical properties of recycled plastic parts. The preliminary experiment is conducted by using Moldflow Plastic Insight (MPI) integrated with the L18 Taguchi orthogonal array (OA). The significant processing parameters obtained from the preliminary experiment were used to conduct the principal experiment. By adopting L9 Taguchi OA, the parts made from recycled plastic were produced by injection molding. ANOVA confirms that the most significant factor for flexural modulus of a recycled toolbox tray is injection time (∼40.49% percentage contribution). For stress at yield, the most significant factor is melt temperature with percentage contribution of about 43.34%. Copyright © Taylor & Francis Group, LLC.

Nejati M.,Universiti Sains Malaysia
Technics Technologies Education Management | Year: 2010

Background: With the emergence of new technologies and increasing competition among organizations for survival and more benefits, evaluating the performance of organization in its different aspects has become a necessity. Yet, among various areas of performance and numerous organizational resources to be controlled, knowledge and intellectual sources are becoming more and more important. Purpose: This paper will discuss the importance of knowledge management performance evaluation by the organizations and deliberate the challenges faced by organizations as well as requirements to be met by organizations to overcome those challenges. Design: In-depth literature review as well as years of experience of author in the field has been used to develop this research. Findings: Some of the most common challenges faced by organizations in implementing knowledge management performance evaluation have been highlighted. Besides, the key requirements which should be met by organizations and solutions to resolve these issues and challenges have been introduced. Finally, knowledge management performance auditing has been introduced as an effective process to monitor the performance of KM practices on a regular basis. Practical implications: Research findings guide organizations in identifying common challenges in the process of evaluating their intellectual assets and knowledge management practices. Originality: The notion of knowledge management performance evaluation is yet under-explored in organizations. This paper is an attempt to investigate it and study the common challenges in front of organizations aiming to implement it, and propose solutions to overcome the challenges.

Othman N.,Northern University of Malaysia | Nasurdin A.M.,Universiti Sains Malaysia
Journal of Nursing Management | Year: 2013

Aim This study addressed the question of whether social support (supervisor support and co-worker support) could contribute to the variance in work engagement. Background Nurses, as customer-contact employees, play an important role in representing the organization's competence. Their attitudes and behaviour toward patients has a significant influence on patients' satisfaction and perception of quality of service. Methods The sample comprised 402 staff nurses working in three general hospitals in Peninsular Malaysia. Variables included demographic information, Utrecht Work Engagement Scale and Social Support Scale. Data analysis included descriptive statistics, correlations and regression analysis. Results Findings indicated that supervisor support was positively related to work engagement. Co-worker support was found to have no effect on work engagement. Conclusions Supervisory support is an important predictor of work engagement for nurses. Implications for nursing management Nursing management should provide more training to nurse supervisors and develop nurse mentoring programmes to encourage more support to nurses. © 2012 John Wiley & Sons Ltd.

Kulandaivelu V.,Coffee Research Sub Station | Bhat R.,Universiti Sains Malaysia
European Journal of Soil Biology | Year: 2012

Discharge of untreated coffee processing wastewater (CPW) into natural water bodies without adequate treatment poses serious threat to environment. In India, due to high cost incurred in construction of 'Effluent Treatment Plants', coffee growers are employing rudimentary land based wastewater storage and treatment facilities at on-farm levels, which affects the soil quality. In the present study, we investigated the effects of untreated CPW at different loading rates (250 m 3, 500 m 3, 750 m 3, and 1000 m 3 per hectare) on soil physico-chemical and biological properties. Higher loading rates of CPW (75-100 L/m 2) were found to significantly increase (p < 0.01) the electrical conductivity (EC), bulk density (BD), water holding capacity (WHC), organic carbon (OC), available nitrogen, available potassium, while the soil pH and available phosphorus were significantly reduced (p < 0.01) by higher loading rates. Application of higher volumes of CPW (75-100 L/m 2) significantly reduced the soil respiration, dehydrogenase (DHA), urease activity and Fluorescin diacetate activity (FDA) at both the soil depths (0-15 and 15-30 cm). Significant decrease in populations of pelops, eulohmannia and springtail was observed with the application of higher volumes of CPW (75-100 L/m 2). CPW at a rate of 25-50 L/m 2 found to significantly increase the population of culturable bacteria (p < 0.01), fungi (p < 0.05) yeast (p < 0.01) and actinomycetes (p < 0.01), while their populations were drastically reduced above 75 L/m 2. In functional microflora, application of CPW at a rate of 25-50 L/m 2 found to significantly increase the population of Pseudomonas fluorescence (p < 0.01), phosphorus solubilisers (p < 0.05), Azotobacter sp. (p < 0.01) and Beijerinkia sp. (p < 0.05) at 0-15 cm. © 2011 Elsevier Masson SAS.

Whittaker A.,Monash University | Chee H.L.,Universiti Sains Malaysia
Social Science and Medicine | Year: 2014

The growing trade in patients seeking health care in other countries, or medical travel, is changing the forms and experiences of health care seeking and producing changes to hospitals in terms of their design, organization and spaces. What is termed in marketing parlance in Thailand as an 'international hospital' oriented to attracting foreign patients, is a hotel-hospital hybrid that is locally produced through the inflexion of local practices to make a therapeutic space for international patients. The paper reports on work undertaken within a Thai hospital in 2012 which included observations and interviews with thirty foreign in-patients and nine informal interviews with hospital staff. Although theorized as a culturally neutral transnational 'space of connectivity', we show how cross-cultural tensions affect the experience of the hospital with implications for the organization of the hospital and notions of 'cultural competence' in care. There is no single universal experience of this space, instead, there are multiple experiences of the 'international hospital', depending on who patients are, where they are from, their expectations and relationships. Such hospitals straddle the expectations of both local patients and international clientele and present highly complex cross-cultural interactions between staff and patients but also between patients and other patients. Spatial organisation within such settings may either highlight cultural difference or help create culturally safe spaces. © 2014 Elsevier Ltd.

Yen S.T.,University of Tennessee at Knoxville | Tan A.K.G.,Universiti Sains Malaysia
International Journal of Public Health | Year: 2012

Objective To investigate the roles of sociodemographic factors in fruit and vegetable (FV) consumption in Malaysia. Methods Data are obtained from the Malaysia Non-Communicable Disease Surveillance-1. Logistic regressions are conducted using a multiracial (Malay, Chinese, Indian and other ethnic groups) sample of 2,447 observations to examine the factors affecting individual decisions to consume FV on a daily basis. Results Based on the binary outcomes of whether individuals consumed FV daily, results indicate that work hours, education, age ethnicity, income, gender, smoking status, and location of residence are significantly correlated with daily fruit consumption. Daily vegetable consumption is significantly correlated with income, gender, health condition, and location of residence. Conclusions Our results imply the need for programs to educate and motivate consumers to make healthier dietary choices. Interventions to increase FV consumption by changing behaviors should be considered, as should those that increase public awareness of the dietary benefits of FV. These intervention programs should be targeted at and tailored toward individuals who are less educated, younger, less affluent, males, smokers, and metropolitan dwellers. © 2012 Swiss School of Public Health.

Yusoff M.S.B.,Universiti Sains Malaysia
International Medical Journal | Year: 2011

Objective: Studies have revealed that the prevalence of distress among medical student is higher compared to normal population and the main stressor was academic especially examinations. This study is interested in gathering data objectively on the impact of summative examination on the USM medical students' mental health. Methods: This is a comparative pre and post cross-sectional study. A total of 260 first year medical students were selected as respondents for the first data collection whereas only 100 medical students were randomly selected for the second data collection. The 12 items General Health Questionnaire (GHQ-12) and Medical Student Stressor Questionnaire (MSSQ) were administered to measure stress level and stressor of the medical students. Stress levels of medical students were measured at two occasions; eight months prior to the examination as the baseline stress level and just after the last paper of the examination as the examination stress level. Result: A total of 213 students responded in the first session and 99 students in the second session. This study showed that the percentage of distressed medical students was significantly increased during summative examination; the baseline percentage of distressed medical students was 26.29% and the percentage of distressed medical students during the examination was 58.59% (X2 = 30.2, p < 0.001). The mean stress level was found to be significantly increased during the examination; the baseline mean stress level was 2.41 and the mean stress level during examination was 4.39 (t = -5.72, p < 0.001). Binary logistic regression showed that medical students were at 3.97 time more risk to develop distressed compared to before the examination (Wald = 28.82, OR (CI 95%) = 3.97 (2.40, 6.56), p < 0.001). Conclusion: The percentage of distressed medical students during the examination was significantly higher compared to before the examination. The mean stress level was significantly high during the examination. Medical students were at high risk to develop distress during summative examination period. © 2011 Japan International Cultural Exchange Foundation & Japan Health Sciences University.

Raabe C.A.,University of Munster | Tang T.-H.,Universiti Sains Malaysia | Brosius J.,University of Munster | Rozhdestvensky T.S.,University of Munster
Nucleic Acids Research | Year: 2014

High-throughput RNA sequencing (RNA-seq) is considered a powerful tool for novel gene discovery and fine-tuned transcriptional profiling. The digital nature of RNA-seq is also believed to simplify meta-Analysis and to reduce background noise associated with hybridization-based approaches. The development of multiplex sequencing enables efficient and economic parallel analysis of gene expression. In addition, RNA-seq is of particular value when low RNA expression or modest changes between samples are monitored. However, recentdata uncovered severe bias in the sequencing of small non-protein coding RNA (small RNA-seq or sRNA-seq), such that the expression levels of some RNAs appeared to be artificially enhanced and others diminished or even undetectable. The use of different adapters and barcodes during ligation as well as complex RNA structures and modifications drastically influence cDNA synthesis efficacies and exemplify sources of bias in deep sequencing. In addition, variable specific RNA G/C-content is associated with unequal polymerase chain reaction amplification efficiencies. Given the central importance of RNA-seq to molecular biology and personalized medicine, we review recent findings that challenge small non-protein coding RNA-seq data and suggest approaches and precautions to overcome or minimize bias. © 2013 The Author(s) 2013. Published by Oxford University Press.

Omar R.,University Putra Malaysia | Idris A.,University Putra Malaysia | Yunus R.,University Putra Malaysia | Khalid K.,University Putra Malaysia | Aida Isma M.I.,Universiti Sains Malaysia
Fuel | Year: 2011

Agricultural waste such as oil palm empty fruit bunch (EFB) is of environmental concern to Malaysia as one of the world's largest oil palm producers. Pyrolysis can be used to treat biomass waste due to its flexibility in producing solid, liquid and gas products. This study attempts to characterize EFB for pyrolysis using microwaves as an alternative heating source. EFB taken from a local oil palm mill was subjected to fuel, chemical and dielectric property analysis. The findings revealed that high moisture and 47% oxygen gave low calorific value of 16 MJ/kg. Notably, high water content is an advantage in microwave heating as water is a good microwave absorber, which results in fast drying. Further, a high volatile content at 70% gave the EFB an advantage of high reactivity. A moderate potassium content of 12.8% could also positively affect microwave absorption. The dielectric properties of EFB were observed to be proportional to the moisture content. Furthermore, the microwave penetration depth was found highest at 20% moisture, i.e. 3.5 cm. However, low values of both dielectric constant and loss of dried EFBs would require the addition of microwave absorbers for pyrolysis reaction. The fuel and chemical characteristics of EFB were found comparable to other biomasses, which indicated a good candidate for microwave pyrolysis treatment. © 2011 Elsevier Ltd All rights reserved.

Lim J.,Carnegie Mellon University | Lim J.,Universiti Sains Malaysia | Lanni C.,Carnegie Mellon University | Evarts E.R.,Carnegie Mellon University | And 3 more authors.
ACS Nano | Year: 2011

Iron oxide cores of 35 nm are coated with gold nanoparticles so that individual particle motion can be tracked in real time through the plasmonic response using dark field optical microscopy. Although Brownian and viscous drag forces are pronounced for nanoparticles, we show that magnetic manipulation is possible using large magnetic field gradients. The trajectories are analyzed to separate contributions from the different types of forces. With field gradients up to 3000 T/m, forces as small as 1.5 fN are detected. © 2011 American Chemical Society.

Mayappan R.,University Technology of MARA | Ahmad Z.A.,Universiti Sains Malaysia
Intermetallics | Year: 2010

The growth kinetics of Cu5Zn8 phase has been investigated under long-term thermal exposure conditions using single shear lap joints. The Cu5Zn8 phase was formed by reacting Sn-Zn and Sn-Zn-Bi lead-free solders with Cu substrate. A scanning electron microscope (SEM) was used to observe the morphology of the phases and energy dispersive X-ray (EDX) was used to estimate the elemental compositions of the phases. The morphology of the Cu5Zn8 phase is rather flat for all the aging temperatures. The Cu6Sn5 isolated phase was observed after long-term aging. Intermetallic thickness measurements show that the thickness of the Cu5Zn8 phase in the Sn-8Zn-3Bi/Cu system is lower than in the Sn-9Zn/Cu system. Subsequently the activation energy for the growth of Cu5Zn8 intermetallic is higher in the presence of Bi. Therefore, the presence of Bi in the Sn-matrix lowers the Zn diffusion and hampers the higher-growth of intermetallics in the Sn-8Zn-3Bi/Cu system compare to the Sn-9Zn/Cu solder interface. © 2009 Elsevier Ltd. All rights reserved.

Radiotherapy plays an essential primary role in cancer patients. Regardless of its significant advances in treatment options, tumor recurrence and radio-resistance in cancer cells still occur in a high percentage of patients. Furthermore, the over expression of miRNAs accompanies the development of radio-resistant cancer cells. Consequently, miRNAs might serve as therapeutic targets for the treatment of radio-resistance in cancer cells. The findings of the current research also signify that the use of a natural anti-miRNA substance could inhibit specific miRNAs, and, concurrently, these natural remedies could exhibit radioprotective activity against the healthy cells during radiotherapy. Therefore, in this review, we have reported the association of miRNAs with radio-resistance and the potential uses of natural remedies as green gene therapeutic approaches, as well as radioprotectors against the adverse effects of irradiation on healthy cells during radiotherapy.

Abougalambou S.S.I.,Universiti Sains Malaysia
Diabetes and Metabolic Syndrome: Clinical Research and Reviews | Year: 2012

Objective: The aim of this study was to determine risk factors and prevalence of diabetic neuropathy (DN) among type II diabetic patients in Malaysian hospital setting. Subjects and methods: a observational prospective longitudinal follow up study design was selected, total no of respondents were 1077 type 2 diabetes mellitus outpatients recruited via attended the diabetes clinics at Hospital Universiti Sains Malaysia (HUSM) in Kelantan. The diagnosis of neuropathy was confirmed by nerve conduction studies. Logistic regression analysis was used to assess the independent variables that affect the development of neuropathy. Results: The prevalence of nephropathy is 54.3%. Longitudinal logistic regression identified four predictive variables on the development and progression of diabetic neuropathy that are: duration of diabetes, retinopathy, HbA1c at second visit, and creatinine clearance third visit. Conclusion: Findings of this study show high prevalence of diabetic neuropathy. HbA1c and creatinine clearance are two modifiable risk factors for the development of diabetic neuropathy. © 2012 Diabetes India.

The effect of isophorone diisocyanate-polyhydroxyl groups as a coupling agent on properties of low density polyethylene/acrylonitrile butadiene styrene/water hyacinth fibers (LDPE/A0BS/WHF) composites was studied. LDPE/ABS (50/50) blends with different unmodified and modified water hyacinth fibers (WHF) loading were prepared with Z-blade mixer at 200° C and rotor speed of 50 rpm. The results indicated that LDPE/ABS/modified WHF composites show higher values of tensile strength, Young's modulus and water absorption resistance than LDPE/ABS/unmodified WHF composites. It was also found that the modified WHF offers better thermal stability than unmodifiedWHFin the LDPE/ABS/WHF composites. © Taylor & Francis Group, LLC.

Lee Y.Y.,Universiti Sains Malaysia | Chua A.S.B.,Gastro Center Ipoh
Journal of Neurogastroenterology and Motility | Year: 2012

The diagnosis of functional dyspepsia (FD) is challenging since it depends largely on symptoms which are often heterogeneous and overlapping. This is particularly so in Asia with many different cultures and languages. Symptom-based diagnosis of FD based on Rome III criteria has not been fully validated and it may not be suitable in some Asian populations. Clinicians often assume that investigations in FD are not rewarding and physiological tests are often not available unless in the research setting. Investigation of alarm features and role of Helicobacter pylori in FD remain controversial but experts agreed that both should be tested. Physiological tests including gastric accommodation and chemical hypersensitivity tests are underutilized in Asia and available studies were few. While experts do not recommend routine clinical use of gastric accommodation tests but they agree that these tests can be advocated if clinically indicated. Empiric therapeutic trial is not currently a diagnostic option. The pathogenesis of FD is still poorly understood and there is a substantial placebo response. As a conclusion, a diagnosis of FD is challenging especially so in the context of Asia and despite the limitations of available physiological tests experts agreed that these tests can be advocated if and when clinically indicated. © 2012 The Korean Society of Neurogastroenterology and Motility.

Ong W.-J.,University of Selangor | Tan L.-L.,University of Selangor | Chai S.-P.,University of Selangor | Yong S.-T.,University of Selangor | Mohamed A.R.,Universiti Sains Malaysia
Nanoscale | Year: 2014

Titanium dioxide (TiO2) is one of the most widely investigated metal oxides due to its extraordinary surface, electronic and catalytic properties. However, the large band gap of TiO2 and massive recombination of photogenerated electron-hole pairs limit its photocatalytic and photovoltaic efficiency. Therefore, increasing research attention is now being directed towards engineering the surface structure of TiO2 at the most fundamental and atomic level namely morphological control of {001} facets in the range of microscale and nanoscale to fine-tune its physicochemical properties, which could ultimately lead to the optimization of its selectivity and reactivity. The synthesis of {001}-faceted TiO2 is currently one of the most active interdisciplinary research areas and demonstrations of catalytic enhancement are abundant. Modifications such as metal and non-metal doping have also been extensively studied to extend its band gap to the visible light region. This steady progress has demonstrated that TiO2-based composites with {001} facets are playing and will continue to play an indispensable role in the environmental remediation and in the search for clean and renewable energy technologies. This review encompasses the state-of-the-art research activities and latest advancements in the design of highly reactive {001} facet-dominated TiO2via various strategies, including hydrothermal/solvothermal, high temperature gas phase reactions and non-hydrolytic alcoholysis methods. The stabilization of {001} facets using fluorine-containing species and fluorine-free capping agents is also critically discussed in this review. To overcome the large band gap of TiO2 and rapid recombination of photogenerated charge carriers, modifications are carried out to manipulate its electronic band structure, including transition metal doping, noble metal doping, non-metal doping and incorporating graphene as a two-dimensional (2D) catalyst support. The advancements made in these aspects are thoroughly examined, with additional insights related to the charge transfer events for each strategy of the modified-TiO2 composites. Finally, we offer a summary and some invigorating perspectives on the major challenges and new research directions for future exploitation in this emerging frontier, which we hope will advance us to rationally harness the outstanding structural and electronic properties of {001} facets for various environmental and energy-related applications. © 2014 The Royal Society of Chemistry.

Noriman N.Z.,University Malaysia Perlis | Ismail H.,Universiti Sains Malaysia
International Journal of Polymeric Materials and Polymeric Biomaterials | Year: 2013

The utilization of nitrile glove waste will spark a great deal of interest in the rubber industry in developing cost-effective techniques to convert waste and used rubber into a processable form. Blends of styrene butadiene rubber/recycled acrylonitrile butadiene rubber (SBR/NBRr) reinforced at 85/15 blend with different ratios of a carbon black/silica (CB/Sil) hybrid filler (50/0, 40/10, 30/20, 20/30, 40/10, 0/50 phr) were tested either with or without the silane coupling agent, Si69. Results showed that the increased thermal stability of blends with Si69 is highly related to the formation of crosslinks between the filler. Thermogravimetric (TG) thermograms showed that the percentage of char residue for blends with Si69 was higher than without Si69. The differential scanning calorimetry (DSC) thermograms of both blends revealed a glass transition temperature (Tg) between 65.0°C and 66.9°C. At all blend ratios, the fatigue life of blends with Si69 was better than blends without Si69. After six months exposure to natural weather, blends with Si69 exhibited better tensile properties, retention, and morphology compared to blends without Si69. © 2013 Copyright Taylor and Francis Group, LLC.

Chen C.K.,Universiti Sains Malaysia
Journal of physiological anthropology | Year: 2012

ABSTRACT: The use of herbs as ergogenic aids in exercise and sport is not novel. Ginseng, caffeine, ma huang (also called 'Chinese ephedra'), ephedrine and a combination of both caffeine and ephedrine are the most popular herbs used in exercise and sports. It is believed that these herbs have an ergogenic effect and thus help to improve physical performance. Numerous studies have been conducted to investigate the effects of these herbs on exercise performance. Recently, researchers have also investigated the effects of Eurycoma longifolia Jack on endurance cycling and running performance. These investigators have reported no significant improvement in either cycling or running endurance after supplementation with this herb. As the number of studies in this area is still small, more studies should be conducted to evaluate and substantiate the effects of this herb on sports and exercise performance. For instance, future research on any herbs should take the following factors into consideration: dosage, supplementation period and a larger sample size.

Lean H.H.,Universiti Sains Malaysia | Smyth R.,Monash University
Urban Studies | Year: 2013

This paper applies univariate and panel Lagrange multiplier (LM) unit root tests with one and two structural breaks to the ratio of the regional to national house price to examine the ripple effect for five different housing price indices (aggregate housing, detached housing, semi-detached housing, terrace housing and high-rise housing) across 14 regional locations in Malaysia. Segmentation is restricted to a small group of states across most housing types for which there is no long-run relationship with the Malaysian average. When all housing types are taken together, evidence of a ripple effect is generally found from the most developed states to the less developed states of Malaysia. While overall rates of conversion to the long-run equilibrium are consistent with a low level of persistence, there is some evidence of regional clusters based on similar speeds of adjustment in different parts of the country. © 2012 Urban Studies Journal Limited.

Azamathulla H.M.,Universiti Sains Malaysia
Journal of Hydroinformatics | Year: 2012

The process involved in the local scour at an abutment is so complex that it makes it difficult to establish a general empirical model to provide accurate estimation for scour. This study presents the use of gene-expression programming (GEP), which is an extension of genetic programming (GP), as an alternative approach to estimate the scour depth. The datasets of laboratory measurements were collected from the published literature and used to train the network or evolve the program. The developed network and evolved programs were validated by using the observations that were not involved in training. The proposed GEP approach gives satisfactory results compared with existing predictors and artificial neural network (ANN) modeling in predicting the scour depth at an abutment. © IWA Publishing 2012.

Murugaiyah V.,Universiti Sains Malaysia | Mattson M.P.,U.S. National Institute on Aging
Neurochemistry International | Year: 2015

The impact of dietary factors on brain health and vulnerability to disease is increasingly appreciated. The results of epidemiological studies, and intervention trials in animal models suggest that diets rich in phytochemicals can enhance neuroplasticity and resistance to neurodegeneration. Here we describe how interactions of plants and animals during their co-evolution, and resulting reciprocal adaptations, have shaped the remarkable characteristics of phytochemicals and their effects on the physiology of animal cells in general, and neurons in particular. Survival advantages were conferred upon plants capable of producing noxious bitter-tasting chemicals, and on animals able to tolerate the phytochemicals and consume the plants as an energy source. The remarkably diverse array of phytochemicals present in modern fruits, vegetables spices, tea and coffee may have arisen, in part, from the acquisition of adaptive cellular stress responses and detoxification enzymes in animals that enabled them to consume plants containing potentially toxic chemicals. Interestingly, some of the same adaptive stress response mechanisms that protect neurons against noxious phytochemicals are also activated by dietary energy restriction and vigorous physical exertion, two environmental challenges that shaped brain evolution. In this perspective article, we describe some of the signaling pathways relevant to cellular energy metabolism that are modulated by 'neurohormetic phytochemicals' (potentially toxic chemicals produced by plants that have beneficial effects on animals when consumed in moderate amounts). We highlight the cellular bioenergetics-related sirtuin, adenosine monophosphate activated protein kinase (AMPK), mammalian target of rapamycin (mTOR) and insulin-like growth factor 1 (IGF-1) pathways. The inclusion of dietary neurohormetic phytochemicals in an overall program for brain health that also includes exercise and energy restriction may find applications in the prevention and treatment of a range of neurological disorders. © Published by Elsevier Ltd.

Chan H.-K.,Sultanah Bahiyah Hospital | Hassali M.A.,Universiti Sains Malaysia
International Journal of Clinical Pharmacy | Year: 2014

Background Inability to read instructions on drug labels has been identified among the Malaysian population since 1990′s. Objective To assess the impact of font-enlarged and pictogram-incorporated labels used for long-term medications on patients’ adherence, comprehension and preferences. Setting Outpatient pharmacy in one of the major general hospitals across Northern Malaysia. Method This was a three-arm, randomized controlled trial. Outpatients with refill prescriptions of selected oral antihypertensive or antidiabetic medications were screened for eligibility. They were randomly allocated with standard (n = 35), font-enlarged (n = 40) or pictogram-incorporated (n = 35) labels. Assessment of baseline adherence scores using the 8-item Morisky Medication Adherence Scale, comprehension scores using a structured questionnaire and preferences was conducted upon recruitment. Follow-up telephone interviews were conducted after 4 weeks. Main outcome measure The changes of patients’ adherence and comprehension scores and their preferences. Results Within-group comparisons demonstrated an increase of total adherence scores after 4 weeks in all three groups (mean changes 0.35, 0.58 and 0.67; p = 0.029, 0.013 and 0.011, respectively). The repeatedly measured total comprehension score of pictogram-incorporated label group was significantly higher than baseline (mean change 0.37, p = 0.010). Two intervention groups obtained significantly higher scores for few items in both adherence and comprehension measurements after 4 weeks as compared with baselines. As indicated by F tests, three groups did not significantly differ in the changes of both total adherence and comprehension scores (p = 0.573 and 0.069, respectively) with the subjects’ age adjusted. Elderlies and those with a higher number of morbidity preferred pictogram-incorporated label over font-enlarged label. Conclusion We did not find a significant change of both adherence and comprehension levels after the introduction of modified medication labels. However, on the basis of within-group comparisons, they may have positive influences on certain aspects of patients’ adherence and comprehension. Variations in preferences may reflect the unique need of different subgroups in receiving written medication instructions. © 2014, Koninklijke Nederlandse Maatschappij ter bevordering der Pharmacie.

Amran A.,Universiti Sains Malaysia | Haniffa R.,University of Bradford
Business Strategy and the Environment | Year: 2011

Current development in social accounting presents an interesting phenomenon. Companies are increasingly engaging in sustainability initiatives and reporting their activities in annual reports, company websites and other media of communication. Unlike previous studies, which have mainly used ex post content analysis of annual reports or other published data to study the relationship between disclosure and possible determinants, this study starts with an interview with the local preparer before the data is triangulated to determine the significant possible determinants. The interview findings are interpreted through institutional theory for possible identification of determinants. Initially, the interview findings indicate that all three mechanisms of isomorphism, the coercive, the normative and the mimetic, contribute to Malaysian company sustainability reporting. However, the regression results prove that only a government linked company in the plantation industry, which is large in size, has a significant amount of sustainability reporting. © 2010 John Wiley & Sons, Ltd. and ERP Environment.

Mahmud S.,Universiti Sains Malaysia
Journal of Alloys and Compounds | Year: 2011

Large and irregularly-shaped zinc oxide (ZnO) micro-particles commonly found in a high-temperature vapor-phase process known as the catalyst-free combust-oxidized mesh (CFCOM) process, play a crucial role as nucleation hosts for ZnO one-dimensional (1D) nanostructures, especially nanometric wires and rods. Nanowires and nanorods tend to grow from the hillocks of the large micro-particles whereby these hillocks serve as nucleation sites for the acicular structures. Nanowires with aspect ratios exceeding 5 are the most common 1D structures that grow from pillar-like hillocks, while triangular hillocks are probable nucleation hosts for nanorods. The ZnO nanostructures possess a polycrystalline nature with photoluminescent emission in the UV band-edge and visible regimes. A novel and non-destructive electrical resistance measurement method is introduced in that the 1D ZnO nanostructures exhibited very high GΩ resistance that is over five times higher than that of commercial ZnO. A growth model is proposed to offer a probable explanation for the fascinating rapid growth of 1D nanostructures originating from large ZnO micro-particles. The ZnO particles in this work were synthesized using 5-ton industrial furnaces via a university-industry joint effort. © 2011 Elsevier B.V. All rights reserved.

Tuck-Po L.,Universiti Sains Malaysia
Human Biology | Year: 2013

The so-called negritos adapt not just to a tropical forest environment but also to an environment characterized by perturbations and fluctuations. As with other hunter-gatherers in the region and, indeed, throughout the world, they use both social and ecological methods to enhance their chances of survival in this changing environment: socially, they have developed networks of trading and marriage partners; ecologically, they maintain patches of key resources that are available for future harvesting. As evidenced in the case of the Batek (Orang Asli), patterns of forest structure and composition are sometimes direct outcomes of intentional resource concentration and enrichment strategies. While little of the above is controversial anthropologically, what has drawn some debate is the nature of the relationship with partner societies. Conventional wisdom posits relations of inequality between foragers and "others": foragers and farmers are often construed as hierarchical dyads where foragers supply products or labor to farmers in exchange for agricultural harvests and other trade goods. This kind of adaptation appears to be one of divergent specialization. However, there are cases, such as in the relationship between Batek and Semaq Beri, where both societies follow a roughly similar mode of adaptation, and specialization has not materialized. In sum, while not denying that hierarchy and inequality exist, I suggest that they have to be contextualized within a larger strand of relationships that includes both hierarchy and egality. Further, such relationships are part of the general portfolio of risk reduction strategies, following which access to widely scattered environmental resources, and passage from one location to another, is enhanced not by competing with and displacing neighbors but by maintaining a flexible regime of friendly exchange partners. © 2013 Wayne State University Press.

Wong W.P.,Universiti Sains Malaysia | Wong K.Y.,University of Technology Malaysia
Journal of Cleaner Production | Year: 2014

The concept of lean is important to sustain operations management. Workers are treated as important assets in lean. In this study, a 'lean-ecosphere' management system is developed for a manufacturing company by using interpretive structural modeling (ISM) and analytical network process (ANP). In the first phase of the methodology, a unified index to set a common objective of people is developed for horizontal integration. In the second phase, a hierarchical relationship model is developed to identify relationships between challenges of lean. This model facilitates the building of a strong foundation of lean to promote the depth of human integration. In the end, the results achieved are compared with the current situation of the company. The results indicated that the scientific methodology for lean management system is very beneficial for the company. This paper adds knowledge to the operations management literature by addressing the human resource factor to create a sustainable operation. © 2014 Elsevier Ltd. All rights reserved.

How H.G.,University of Malaya | Masjuki H.H.,University of Malaya | Kalam M.A.,University of Malaya | Teoh Y.H.,University of Malaya | Teoh Y.H.,Universiti Sains Malaysia
Energy | Year: 2014

An experimental investigation on engine performance, emissions, combustion and vibration characteristics with coconut biodiesel fuels was conducted in a high-pressure common-rail diesel engine under five different load operations (0.17, 0.34, 0.52, 0.69 and 0.86MPa). The test fuels included a conventional diesel fuel and four different fuel blends of coconut biodiesel (B10, B20, B30 and B50). The results showed that biodiesel blended fuels have significant influences on the BSFC (brake specific fuel consumption) and BSEC (brake specific energy consumption) at all engine loads. In general, the use of coconut biodiesel blends resulted in a reduction of BSCO (brake specific carbon monoxide) and smoke emissions regardless of the load conditions. A large reduction of 52.4% in smoke opacity was found at engine load of 0.86MPa engine load with B50. For combustion characteristics, a slightly shorter ignition delay and longer combustion duration were found with the use of biodiesel blends under all loading operations. It was found that generally the biodiesel blends produced lower peak heat release rate than baseline diesel. The vibration results showed that the largest reduction of 13.7% in RMS (root mean square) of acceleration was obtained with B50 at engine load of 0.86MPa with respect to the baseline diesel. © 2014 Elsevier Ltd.

Najafzadeh M.,Shahid Chamran University | Azamathulla H.M.,Universiti Sains Malaysia
Journal of Computing in Civil Engineering | Year: 2015

In this paper, the neuro-fuzzy based group method of data handling (NF-GMDH) as an adaptive learning network was used to predict the scour process at pile groups due to waves. The NF-GMDH network was developed using the particle swarm optimization (PSO) algorithm and gravitational search algorithm (GSA). Effective parameters on the scour depth include sediment size, geometric property, pile spacing, arrangement of pile group, and wave characteristics upstream of group piles. Seven dimensionless parameters were obtained to define a functional relationship between input and output variables. Published data were compiled from the literature for the scour depth modeling due to waves. The efficiency of training stages for both NF-GMDH-PSO and NF-GMDH-GSA models were investigated. The results indicated that NF-GMDH models could provide more accurate predictions than those obtained using model tree and traditional equations. © 2014 American Society of Civil Engineers.

Nik Rosmawati N.H.,Universiti Sains Malaysia
Asian Pacific Journal of Cancer Prevention | Year: 2010

Introduction: Breast cancer is the leading cancer in women today and the major challenge is late presentation then later contributes to poor outcome and high fatality rate. Mammography is effective in early detection of breast cancer and consequently significantly improves the breast cancer survival. Materials and Methods: This cross-sectional study was used to study the knowledge and awareness towards mammogram amongst women aged 15 years old and above. A systemic random sampling was applied and information gathered through guided interview by using a structured questionnaire. Results: Eighty-six respondents were recruited. The mean age of respondents was 40.5 years (SD: 15.51) and more than 80% had secondary and tertiary level of education. The percentage of respondents ever performed mammogram was 10.5% (95% CI: 4.0%-17.0%). The rate of correct answers was between 8.1% and 48.8%. Most of the respondents do not sure the answer (45.3%-61.6%) rather than wrongly answer (4.7%-43.0%). Only about 8% truly answer that mammogram should be done once in a life. There are 10.5% of women claimed that mammogram had no serious side effect and not a painful procedure. Nearly half of respondents (48.8%) correctly mentioned that Mammogram can detect breast cancer in early stage. Conclusion: Only a small percentage of women ever performed mammogram and there are seriously unaware and poor knowledge pertaining to mammography screening for breast cancer among women in sub urban area. A massive health education campaign through multiple methods and agencies are needed to enhance the knowledge and awareness on mammogram.

Rosmawati N.H.N.,Universiti Sains Malaysia
Asian Pacific Journal of Cancer Prevention | Year: 2010

Introduction: Breast cancer is the most frequently diagnosed cancer in Malaysian women, irrespective of age group and ethnicity. The observed low survival rates are related to late stage at presentation despite the availability of breast self examination (BSE) as a reliable screening method for early detection. Materials and Methods: This cross-sectional study was designed to determine the knowledge, attitude and practice towards BSE amongst women aged 15 years old and above. Systemic random sampling was applied and information gathered through guided interview by using a structured questionnaire. Results: A total of 86 respondents were recruited, with a mean age of 40.5 years (SD: 15.51), more than 80% having a secondary or tertiary level of education. The total score was 16.9 (total mean percent: 60.4%) for knowledge, 37.1 (77.3%) for attitude and 9.56 (34.1%) for practice. The proportions of respondents with good score for knowledge, attitude and practice were 38.4%, 73.3% and 7.0%, respectively. Not knowing the correct method of BSE, lack of knowledge on cancer signs and lack of motivational support from parents, spouse or friends appeared to be related with the poor practices. Conclusion: Enhancement of breast cancer awareness and focusing on recognized barriers by health care professionals with the involvement of spouses, family and community would have a substantial beneficial impact on BSE practice.

Lean H.H.,Universiti Sains Malaysia | Smyth R.,Monash University
Renewable and Sustainable Energy Reviews | Year: 2014

The objective of this paper is to examine whether energy consumption in Malaysia, disaggregated by sector and type, is stationary or contains a unit root. To realize our objective we apply the Lagrange multiplier (LM) family of unit root tests with up to two structural breaks. Depending on the decision rule for selecting between results in the no-break, one-break and two-break cases, we find that energy consumption is stationary for between 50 per cent and 70 per cent of the disaggregated energy series and between 25 per cent and 50 per cent of sectors. Implications for the Malaysian government's attempts to reduce fossil fuel consumption are discussed. © 2013 Elsevier Ltd.

Wan Hassan W.M.N.,Universiti Sains Malaysia
Malaysian Journal of Medical Sciences | Year: 2013

Awake craniotomy is a brain surgery performed on awake patients and is indicated for certain intracranial pathologies. These include procedures that require an awake patient for electrocorticographic mapping or precise electrophysiological recordings, resection of lesions located close to or in the motor and speech of the brain, or minor intracranial procedures that aim to avoid general anaesthesia for faster recovery and earlier discharge. This type of brain surgery is quite new and has only recently begun to be performed in a few neurosurgical centres in Malaysia. The success of the surgery requires exceptional teamwork from the neurosurgeon, neuroanaesthesiologist, and neurologist. The aim of this article is to briefly describe the history of awake craniotomy procedures at our institution. © Penerbit Universiti Sains Malaysia, 2013.

Mohamed K.,Universiti Sains Malaysia | Alkaisi M.M.,MacDiarmid Institute for Advanced Materials and Nanotechnology
Nanotechnology | Year: 2013

This work investigates the development of a nanofabrication process to achieve high aspect-ratio nanostructures on quartz substrates using electron beam lithography (EBL) patterning and fluorinated plasma etching processes. An imaging layer of a poly(methyl methacrylate) bi-layer resist was spun coated on quartz substrate and exposed by an e-beam with the designed patterns of sub-100 nm feature sizes using a Raith-150 EBL patterning tool. Additive pattern transfer was employed by depositing a 40 nm thick Nichrome layer on the resist pattern using a metal evaporator which was later lifted off by soaking in acetone. Nichrome was employed as an etch mask and an Oxford Plasmalab 80Plus reactive ion etcher was used for the etching process. The etching process was carried out in a gas mixture of CHF3/Ar with a flow rate ratio of 50/30 sccm, pressure of 20 mTorr, radiofrequency power of 200 W and at room temperature. These etching process parameters were found to achieve a 10 nm min-1 etch rate and tall vertical side walls profile. An aspect-ratio of 10:1 was achieved on 60 nm feature size structures. © 2013 IOP Publishing Ltd.

Lean H.H.,Universiti Sains Malaysia | Smyth R.,Monash University
Renewable and Sustainable Energy Reviews | Year: 2013

This study examines whether policies to promote renewable electricity generation are likely to be effective by applying panel unit root and stationarity tests to time series data on renewable electricity generation for 115 countries over the period 1980-2008. We find that for the panel as a whole, and almost three quarters of the individual countries, renewable electricity generation is characterized by a unit root. This result implies that policies to promote renewable electricity generation, such as renewable portfolio standards, which result in annual increases in renewable energy and, as such, which represent permanent positive shocks to the long-run growth path of renewable electricity generation, will be more effective in increasing renewable electricity generation than policies with a pre-specified time horizon. © 2013 Elsevier Ltd.

Al-Mulali U.,University of Technology Malaysia | Fereidouni H.G.,University of Technology Malaysia | Lee J.Y.,University of Technology Malaysia | Sab C.N.B.C.,Universiti Sains Malaysia
Renewable and Sustainable Energy Reviews | Year: 2013

The bi-directional long run relationship between renewable energy consumption and GDP growth has been investigated in high income, upper middle income, lower middle income, and high income countries. To achieve this goal, the fully modified OLS was utilized. The results revealed that 79% of the countries have a positive bi-directional long run relationship between renewable energy consumption and GDP growth. This represents the feedback hypothesis. On the other hand, 19% of the countries showed no long run relationship between the variables. This represents the neutrality hypothesis. Besides, 2% of the countries showed a one way long run relationship from GDP growth to renewable energy consumption, confirming the conservation hypothesis, and from renewable energy consumption and GDP growth representing the growth hypothesis. Despite the mixed results across countries, it has been proved that the more persistent and significant the bi-directional long run relationship between the variables is, the higher the income countries are. © 2013 Elsevier Ltd.

Nurfitri I.,Universiti Malaysia Pahang | Maniam G.P.,Universiti Malaysia Pahang | Hindryawati N.,Universiti Malaysia Pahang | Yusoff M.M.,Universiti Malaysia Pahang | Ganesan S.,Universiti Sains Malaysia
Energy Conversion and Management | Year: 2013

For many years, the cost of production has been the main barrier in commercializing biodiesel, globally. It has been well researched and established in the literature that the cost of feedstock is the major contributor. Biodiesel producers are forced to choose between edible and non-edible feedstock. The use of edible feedstock sparks concern in terms of food security while the inedible feedstock needs additional pretreatment steps. On the other hand, the wide availability of edible feedstock guarantees the supply while the choice of non-edible results in a non-continuous or non-ready supply. With these complications in mind, this review attempts to identify possible solutions by exploring the potential of waste edible oils and waste catalysts in biodiesel preparation. Since edible oils are available and used abundantly, waste or used edible oils have the potential to provide plentiful feedstock for biodiesel. In addition, since traditional homogeneous catalysts are less competent in transesterifying waste/used oils, this review includes the possibility of heterogeneous catalysts from waste sources that are able to aid the transesterification reaction with success. © 2013 Elsevier B.V.

Atabani A.E.,University of Malaya | Mahlia T.M.I.,University of Tenaga Nasional | Anjum Badruddin I.,University of Malaya | Masjuki H.H.,University of Malaya | And 2 more authors.
Renewable and Sustainable Energy Reviews | Year: 2013

Recently, non-edible vegetable oils have been considered as prospective feedstocks for biodiesel production. This is mainly attributed to their ability to overcome the problems of food versus fuel crisis related to edible oils. Globally, there are more than 350 oil-bearing crops identified as potential sources for biodiesel production. The evaluation of the physical and chemical properties of non-edible feedstocks is very important to assess their viability for future biodiesel production. Therefore, this paper aims to study the properties of some potential non-edible feedstocks. Moreover, the paper studies the physical and chemical properties of these promising crops and compares them with other edible oils. These oils include: crude Calophyllum inophyllum L. (CCIO), Jatropha curcas L. (CJCO), Sterculia foetida L. (CSFO), Croton megalocarpus L. (CCMO), Moringa oleifera L. (CMOO), patchouli (CPO), coconut (CCO), palm (CPaO), canola (CCaO), soybean (CSO) and Pangim edule (CPEO) oils. 14 Different properties have been determined and presented in this study. © 2013 Elsevier Ltd.

Al-mulali U.,Multimedia University | Tang C.F.,Universiti Sains Malaysia | Ozturk I.,Cag University
Environmental Science and Pollution Research | Year: 2015

The purpose of this study is to explore the effect of financial development on CO2 emission in 129 countries classified by the income level. A panel CO2 emission model using urbanisation, GDP growth, trade openness, petroleum consumption and financial development variables that are major determinants of CO2 emission was constructed for the 1980–2011 period. The results revealed that the variables are cointegrated based on the Pedroni cointegration test. The dynamic ordinary least squares (OLS) and the Granger causality test results also show that financial development can improve environmental quality in the short run and long run due to its negative effect on CO2 emission. The rest of the determinants, especially petroleum consumption, are determined to be the major source of environmental damage in most of the income group countries. Based on the results obtained, the investigated countries should provide banking loans to projects and investments that can promote energy savings, energy efficiency and renewable energy to help these countries reduce environmental damage in both the short and long run. © 2015, Springer-Verlag Berlin Heidelberg.

Tan L.-L.,University of Selangor | Chai S.-P.,University of Selangor | Mohamed A.R.,Universiti Sains Malaysia
ChemSusChem | Year: 2012

Graphene is one of the most promising materials in the field of nanotechnology and has attracted a tremendous amount of research interest in recent years. Due to its large specific surface area, high thermal conductivity, and superior electron mobility, graphene is regarded as an extremely attractive component for the preparation of composite materials. At the same time, the use of photocatalysts, particularly TiO 2, has also been widely studied for their potential in addressing various energy and environmental-related issues. However, bare TiO 2 suffers from low efficiency and a narrow light-response range. Therefore, the combination of graphene and TiO 2 is currently one of the most active interdisciplinary research areas and demonstrations of photocatalytic enhancement are abundant. This Review presents and discusses the current development of graphene-based TiO 2 photocatalysts. The theoretical framework of the composite, the synthetic strategies for the preparation and modification of graphene-based TiO 2 photocatalysts, and applications of the composite are reviewed, with particular attention on the photodegradation of pollutants and photocatalytic water splitting for hydrogen generation. Power in the mix: The incorporation of TiO 2 onto graphene is gaining tremendous research interest as it presents the opportunity to simultaneously cover all mechanisms of photocatalytic enhancement. Herein, the theoretical framework, synthetic strategies for the preparation and modification, and applications of these photocatalysts are reviewed, with particular attention on the photodegradation of pollutants and photocatalytic water splitting for hydrogen generation. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zyoud S.H.,Universiti Sains Malaysia | Al-Jabi S.W.,An Najah National University | Sweileh W.M.,An Najah National University
Human and Experimental Toxicology | Year: 2015

Purpose: There is a lack of data concerning the evaluation of scientific research productivity in paracetamol poisoning from the world. The purposes of this study were to analyse the worldwide research output related to paracetamol poisoning and to examine the authorship pattern and the citations retrieved from the Scopus database forover a decade.Methods: Data were searched for documents with specific words regarding paracetamol poisoning as 'keywords' in the title or/and abstract. Scientific output was evaluated based on a methodology developed and used in other bibliometric studies. Research productivity was adjusted to the national population and nominal gross domestic product (GDP) per capita.Results: There were 1721 publications that met the criteria during study period from the world. All retrieved documents were published from 72 countries. The largest number of articles related to paracetamol poisoning was from the United States (US; 30.39%), followed by India (10.75%) and the United Kingdom (UK; 9.36%). The total number of citations at the time of data analysis was 21,109, with an average of 12.3 citations per each documents and median (interquartile range) of 4 (1-14). The h-index of the retrieved documents was 57. After adjusting for economy and population power, India (124.2), Nigeria (18.6) and the US (10.5) had the highest research productivity. Countries with large economies, such as the UK, Australia, Japan, China and France, tended to rank relatively low after adjustment for GDP over the entire study period.Conclusion: Our study demonstrates evidence that research productivity related to paracetamol poisoning has increased rapidly during the recent years. The US obviously dominated in research productivity. However, certain smaller country such as Nigeria has high scientific output relative to their population size and GDP. A highly noticeable increase in the contributions of Asia-Pacific and Middle East regions to scientific literature related to paracetamol poisoning was also observed. © The Author(s) 2014.

Aljumah K.,Al Amal Psychiatric Hospital | Hassali A.A.,Universiti Sains Malaysia | AlQhatani S.,Al Amal Psychiatric Hospital
Neuropsychiatric Disease and Treatment | Year: 2014

Background: Adherence to antidepressant treatment is an essential step in the management of patients with major depressive disorder, and several factors can contribute to antidepressant nonadherence. Evidence supports the hypothesis that patient treatment satisfaction will result in improved adherence; therefore, the aim of this study was to investigate the relationship between patient treatment satisfaction and adherence to antidepressants, and the role of patient beliefs toward medication in patient treatment satisfaction. Methods: This was an observational, nonexperimental survey of all patients attending Al Amal Psychiatric Hospital (500 beds) in Riyadh, Saudi Arabia. Medication adherence was assessed using the eight-item Morisky Medication Adherence Scale (MMAS-8), and treatment satisfaction was assessed using the Treatment Satisfaction Questionnaire for Medication (TSQM 1.4). Results: A total of 403 patients met the inclusion criteria; 50.4% were females; participant age ranged from 18 to 60 years; and 16 % of the patients reported side effects after using antidepressants. Both males and females reported high treatment satisfaction rates: - 79.21% (standard deviation [SD] 8.52) and 86.55% (SD 14.34), respectively - with statistically significant associations found for female sex, older age, and three or more physician visits per year. Adherence to antidepressants was associated with treatment satisfaction with the antidepressants, with a direct positive correlation. Conclusion: The results of this study showed high treatment satisfaction scores among patients in Saudi Arabia with major depressive disorder, which correlated with adherence and patient beliefs about the necessity of treatment. This finding has improved the understanding of the role of patient beliefs, which can help caregivers and other stakeholders to improve satisfaction with antidepressants. © 2014 Aljumah et al.

Norsa'adah B.,Universiti Sains Malaysia
Asian Pacific journal of cancer prevention : APJCP | Year: 2013

The incidence of hepatocellular carcinoma (HCC) is relatively high in Southeast Asia. Globally, HCC has a high fatality rate and short survival. The objectives of this retrospective cohort study were to review the epidemiology and survival of HCC patients at a tertiary centre in north-east of Peninsular Malaysia. Subjects were adult HCC patients diagnosed by histopathology or radio-imaging. Secondary liver carcinoma was excluded. Kaplan Meier and multiple Cox proportional hazard survival analyses were used. Only 210 HCC cases from years 1987-2008, were included in the final analysis. The number of cases was increasing annually. The mean age was 55.0 (SD 13.9) years with male:female ratio of 3.7:1. Approximately 57.6% had positive hepatitis B virus, 2.4% hepatitis C virus, 20% liver cirrhosis and 8.1% chronic liver disease. Only 2.9% had family history and 9.0% had frequently consumed alcohol. Most patients presented with abdominal pain or discomfort and had hepatomegaly, 47.9% had an elevated α-fetoprotein level of 800 IU/ml or more, 51.9% had multiple tumors and 44.8% involved multiple liver lobes. Approximately 63.3% were in stage 3 and 23.4% in stage 4, and 82.9% did not receive any treatment. The overall median survival time was 1.9 months (95% confidence interval (CI): 1.5, 2.3). The 1-month, 6-month, 1-year and 2-year survival rates were 71.8%, 23.3%, 13.0% and 7.3% respectively. Significant prognostic factors were Malay ethnicity [Adjusted hazard ratio (AHR) 1.6; 95%CI: 1.0, 2.5; p=0.030], no chemotherapy [AHR 1.7; 95%CI: 1.1, 2.5; p=0.017] and Child-Pugh class C [AHR 2.6; 95%CI: 1.4, 4.9; p=0.002]. HCC in our study affected a wide age range, mostly male, in advanced stage of disease, with no treatment and very low survival rates. Primary prevention should be advocated in view of late presentation and difficulty of treatment. Vaccination of hepatitis virus and avoidance of liver toxins are to be encouraged.

Sobhani F.A.,International Islamic University Chittagong | Amran A.,Universiti Sains Malaysia | Zainuddin Y.,Universiti Malaysia Pahang
Journal of Cleaner Production | Year: 2012

This study aims to describe the status of disclosure practices of corporate sustainability in the annual reports and corporate websites of the banking industry in Bangladesh. It is revealed in the study that, to varying degrees, all listed banks practice sustainability disclosure in an unstructured manner in both the annual reports and corporate websites. The annual report surpasses the corporate website in the disclosure of all categories of corporate sustainability disclosure (CSD) practices except product responsibility disclosure. Unlike the environmental and economic dimensions, issues concerning the social dimension are generally disclosed. Islamic banks disclose more sustainability information in comparison to conventional banks. It is also found that among the three generation, the older bank does not outperform the younger bank in terms of the sustainability disclosure. © 2011 Elsevier Ltd. All rights reserved.

Kuah C.T.,University of Technology Malaysia | Wong K.Y.,University of Technology Malaysia | Wong W.P.,Universiti Sains Malaysia
Expert Systems with Applications | Year: 2012

The paper targets to devise a genuine Knowledge Management (KM) performance measurement model in a stochastic setting based on Data Envelopment Analysis (DEA), Monte Carlo simulation and Genetic Algorithm (GA). The proposed model evaluates KM using a set of proxy measures correlated with the major KM processes. Data Collection Budget Allocation (DCBA) that maximizes the model accuracy is determined using GA. Additional data are generated and analyzed using a Monte-Carlo-enhanced DEA model to obtain the overall KM efficiency and KM processes' efficiency scores. An application of the model has been carried out to evaluate KM performance in higher educational institutions. It is found that with GA, the accuracy of the model has been greatly improved. Lastly, comparing with a conventional deterministic DEA model, the results from the proposed model would be more useful for managers to determine future strategies to improve their KM. © 2012 Elsevier Ltd. All rights reserved.

Zerafat Angiz L. M.,Islamic Azad University | Emrouznejad A.,Aston University | Mustafa A.,Universiti Sains Malaysia
Expert Systems with Applications | Year: 2012

Data envelopment analysis (DEA) as introduced by Charnes, Cooper, and Rhodes (1978) is a linear programming technique that has widely been used to evaluate the relative efficiency of a set of homogenous decision making units (DMUs). In many real applications, the input-output variables cannot be precisely measured. This is particularly important in assessing efficiency of DMUs using DEA, since the efficiency score of inefficient DMUs are very sensitive to possible data errors. Hence, several approaches have been proposed to deal with imprecise data. Perhaps the most popular fuzzy DEA model is based on α-cut. One drawback of the α-cut approach is that it cannot include all information about uncertainty. This paper aims to introduce an alternative linear programming model that can include some uncertainty information from the intervals within the α-cut approach. We introduce the concept of "local α-level" to develop a multi-objective linear programming to measure the efficiency of DMUs under uncertainty. An example is given to illustrate the use of this method. © 2011 Elsevier Ltd. All rights reserved.

Behzadian M.,University of Tehran | Khanmohammadi Otaghsara S.,Islamic Azad University at Firoozkooh | Yazdani M.,Islamic Azad University at Firoozkooh | Ignatius J.,Universiti Sains Malaysia
Expert Systems with Applications | Year: 2012

Multi-Criteria Decision Aid (MCDA) or Multi-Criteria Decision Making (MCDM) methods have received much attention from researchers and practitioners in evaluating, assessing and ranking alternatives across diverse industries. Among numerous MCDA/MCDM methods developed to solve real-world decision problems, the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) continues to work satisfactorily across different application areas. In this paper, we conduct a state-of-the-art literature survey to taxonomize the research on TOPSIS applications and methodologies. The classification scheme for this review contains 266 scholarly papers from 103 journals since the year 2000, separated into nine application areas: (1) Supply Chain Management and Logistics, (2) Design, Engineering and Manufacturing Systems, (3) Business and Marketing Management, (4) Health, Safety and Environment Management, (5) Human Resources Management, (6) Energy Management, (7) Chemical Engineering, (8) Water Resources Management and (9) Other topics. Scholarly papers in the TOPSIS discipline are further interpreted based on (1) publication year, (2) publication journal, (3) authors' nationality and (4) other methods combined or compared with TOPSIS. We end our review paper with recommendations for future research in TOPSIS decision-making that is both forward-looking and practically oriented. This paper provides useful insights into the TOPSIS method and suggests a framework for future attempts in this area for academic researchers and practitioners. © 2012 Elsevier Ltd. All rights reserved.

Othman N.H.,Universiti Sains Malaysia
Evidence-based Complementary and Alternative Medicine | Year: 2012

Honey and cancer has a sustainable inverse relationship. Carcinogenesis is a multistep process and has multifactorial causes. Among these are low immune status, chronic infection, chronic inflammation, chronic non healing ulcers, obesity, and so forth. There is now a sizeable evidence that honey is a natural immune booster, natural anti-inflammatory agent, natural antimicrobial agent, natural cancer vaccine, and natural promoter for healing chronic ulcers and wounds. Though honey has substances of which the most predominant is a mixture of sugars, which itself is thought to be carcinogenic, it is understandable that its beneficial effect as anticancer agent raises skeptics. The positive scientific evidence for anticancer properties of honey is growing. The mechanism on how honey has anticancer effect is an area of great interest. Among the mechanisms suggested are inhibition of cell proliferation, induction of apoptosis, and cell-cycle arrest. Honey and cancer has sustainable inverse relationship in the setting of developing nations where resources for cancer prevention and treatment are limited. Copyright © 2012 Nor Hayati Othman.

Uddin Md.J.,Bangladesh American International University | Beg O.A.,Propulsion Research | Ismail A.I.,Universiti Sains Malaysia
Journal of Thermophysics and Heat Transfer | Year: 2015

Steady two-dimensional laminar mixed convective boundary-layer slip nanofluid flow in a Darcian porous medium due to a stretching/shrinking sheet is studied theoretically and numerically.Athermal radiative effect is incorporated in the model. The governing transport, partial differential equations, along with the boundary conditions, are transformed into a dimensionless form and then, via a linear group of transformation, a system of coupled similarity differential equations is derived. The transformed equations are solved numerically using the Runge-Kutta-Fehlberg fourth-fifth-order numerical quadrature method from Maple symbolic software. The effects of the controlling parameters (namely, stretching/shrinking, velocity slip, thermal slip, mass slip, Darcy number, radiation conduction, buoyancy ratio parameter, and Lewis number) on the dimensionless velocity, temperature, nanoparticle volume fraction, velocity gradient, temperature gradient, and nanoparticle volume fraction gradient are shown in graphical form and interpreted in detail. Comparisons with published works are carried out and are found to be in excellent agreement. The current study is relevant to high-temperature nanomaterials processing operations. Copyright © 2014 by the American Institute of Aeronautics and Astronautics, Inc.

Reddy S.C.,Universiti Sains Malaysia
International Journal of Ophthalmology | Year: 2012

AIM: To report various ocular lesions caused by accidental instillation of superglue. METHODS: Three cases of ocular injuries are described in children aged 6 years, 3 years and 8 months, following accidental instillation of superglue in the eye. RESULTS: In the first case there was sticking of eyelashes in the medial 1/3 of eyelids in both eyes. In the second case sticking of eye lashes was present in the lateral 1/3 of eyelids in the left eye. In the third case, superglue was present on the right cheek, above the right ear and sticking of eyelids in medial 1/3 in right eye. The eyelids were separated by pulling the lid margins with fingers in the first case and later on superglue was removed by trimming the eyelashes; and by direct trimming the eyelashes in second and third cases. There was no injury to other structures of anterior segment in the first two cases. However, removal of the superglue on the cornea resulted in corneal abrasion in the third case which healed with medical treatment and patching of the right eye. CONCLUSION: Accidental instillation of superglue is possible because of the appearance of the tube like eye ointment tube. Immediate medical aid will prevent ocular morbidity. Copyright International Journal of Ophthalmology Press.

Nauheimer L.,University of Leipzig | Boyce P.C.,Universiti Sains Malaysia
Plant Systematics and Evolution | Year: 2014

The new monotypic genus Englerarum Nauheimer & P.C.Boyce, with the only species Englerarum hypnosum (J.T.Yin, Y.H.Wang & Z.F.Xu) Nauheimer & P.C.Boyce, is here described. The new combination of Alocasia hypnosa J.T.Yin, Y.H.Wang & Z.F.Xu, with exclusion of Alocasia (Schott) G.Don and transfer into Englerarum, is based on molecular phylogenies using plastid and nuclear data. The plant occurs on forested limestone outcrops in tropical and subtropical continental Southeast Asia, ranging from Southwest China, through the Lao PDR, and into North and Southeast Thailand. Englerarum represents an isolated lineage in the basal Pistia-clade. Its inclusion into the phylogenetic framework provides new insights into the evolution of this clade, and into the morphological characters used to distinguish the close related genera Alocasia and Colocasia. © 2013 Springer-Verlag Wien.

Ramayah T.,Universiti Sains Malaysia | Omar R.,University Technology of MARA
International Journal of Information Technology and Decision Making | Year: 2010

The purpose of this study is to examine the effects of operational and strategic information exchange on supply chain performance and the moderating role of information quality in relation to both operational and strategic information exchange. The study was conducted using manufacturing companies located in the Northern region of Malaysia. Hierarchical multiple regressions were applied to test the hypotheses developed for the study. It was found that operational and strategic information exchange is significantly related to supply chain performance. The impact of strategic information exchange is greater as opposed to operational information exchange. Information quality does not moderate the relationship between both operational and strategic information exchange and supply chain performance. Nonetheless, this study provides evidence that both strategic information exchange and operational information exchange are required to enhance supply chain performance. As such supply chain partners should effectively exchange strategic information as the impact is greater on performance. © 2010 World Scientific Publishing Company.

Lean H.H.,Universiti Sains Malaysia | Smyth R.,Monash University
Energy | Year: 2010

This paper employs annual data for Malaysia from 1970 to 2008 to examine the causal relationship between economic growth, electricity generation, exports and prices in a multivariate model. We find that there is unidirectional Granger causality running from economic growth to electricity generation. However, neither the export-led nor handmaiden theories of trade are supported and there is no causal relationship between prices and economic growth. The policy implication of this result is that electricity conservation policies, including efficiency improvement measures and demand management policies, which are designed to reduce the wastage of electricity and curtail generation can be implemented without having an adverse effect on Malaysia's economic growth. © 2010 Elsevier Ltd.

Mey S.C.,Universiti Sains Malaysia
International Journal of Special Education | Year: 2011

This study attempts to identify the drivers and inhibitors of employment for people with disabilities in Malaysia. It explores the skills and psychological traits needed by people with disabilities in order to get jobs and the barriers to their employment. Data include interviews detailing the viewpoints of 24 teachers with visual impairments. These teachers are registered and classified as either legally blind or partially sighted by the Malaysian Social Welfare Department. The majority of them are male, Malay, between 30-40 years old and have diploma qualification from Teachers Training College. The interviews were transcribed verbatim. Keywords or phrases were extracted, clustered, and interpreted into themes. Analyzed data were confirmed with the participants to ensure trustworthiness and reliability. The findings provide interesting insights into the specific employment issues faced by people with visual impairments and also shed lights on the issues encountered by people with other types of disability. It also discusses measures that can be taken to improve the employment rate of people with disabilities in the country. A discussion of the research findings is also provided.

Zerafat Angiz L M.,Northern University of Malaysia | Mustafa A.,Universiti Sains Malaysia
Knowledge-Based Systems | Year: 2013

Data envelopment analysis (DEA) is a nonparametric model which evaluates the relative efficiencies of decision-making units (DMUs). These DMUs produce multiple outputs by using multiple inputs and the relative efficiency is evaluated using a ratio of total weighted output to total weighted input. In this paper an alternative interpretation of efficiency is first given. The interpretation is based on the fuzzy concept even though the inputs and outputs data are crisp numbers. With the interpretation, a new model for ranking DMUs in DEA is proposed and a new perspective of viewing other DEA models is now made possible. The model is then extended to incorporate situations whereby some inputs or outputs, in a fuzzy sense, are almost discretionary variables. © 2013 Elsevier B.V. All rights reserved.

Wah L.L.,Universiti Sains Malaysia
International Journal of Special Education | Year: 2010

This paper provides a snapshot into how three individual schools from three different countries practice inclusive education. In the case of the UK primary school, inclusive practices are focused on the provision of external resources and expertise to supplement instruction in the classroom. In the Netherlands, the focus is on teacher change through change of attitude and in-service development of skills. The third case, a Malaysian case, highlights the discrete relationship between special educators and regular teachers in providing inclusive education in their school The research evidence shows that strategies to promote inclusive education is dependent on the current strengths and needs of organizations. Each of these organizations embraces inclusive education by capitalizing on their own strengths. It is proposed that inclusive education be interpreted based on situational contexts and should be broad enough to encompass a continuum of needs. The implication of this is that inclusion is an ongoing developmental process whereby all organizations can continue to develop towards greater inclusion whatever is its present state.

Murugaiah C.,Universiti Sains Malaysia
Critical Reviews in Microbiology | Year: 2011

Cholera is an acute secretory diarrheal disease that is perceived by World Health Organization (WHO) to be a highly contagious threat. Firstly discovered by an Italian physician, Filippo Pacini, the disease gains a reputation as the most feared epidemic diarrheal disease encountered in developing countries. Despite effort taken by WHO to reduce the incidence rate, cholera-endemic prevail in certain regions. Factors that contribute to the disease transmission and ongoing spreading in cholera-prone areas remain as elusive. Should an awareness and knowledge of cholera be developed, it is the residents of developing nation that stand to benefit the most. This review gives insight into the disease prevalence, pandemic, epidemiology, pathogenesis, disease transmission, major strategies and steps to be pursued toward controlling cholera. © 2011 Informa Healthcare USA, Inc.

Zahiri A.,Gorgan University of Agricultural Sciences and Natural Resources | Azamathulla H.,Universiti Sains Malaysia | Bagheri S.,Gorgan University of Agricultural Sciences and Natural Resources
Journal of Hydrology | Year: 2013

Side weirs are one of the most common diversion structures used for flow control, irrigation, drainage networks, and waste-water channels. Side weirs are generally rectangular sharp crested in form and hence, have some limitations in precise flow measurement. For accurate flow measurement and management in wide range of discharges, use of compound side weirs are suggested in this study. Experiments have been carried out in a rectangular compound side weir with variable heights and widths. It was determined that discharge coefficient of a compound side weir is a function of upstream Froude number (Fr1), ratio of weighted crest height of weir to upstream water depth w̄/y1 and ratio of weir length to upstream water depth (L/y1). Based on the experimental data and regression modeling, a dimensionless equation has been developed for prediction of the discharge coefficient and an equation has been proposed for estimation of flow discharge in compound rectangular sharp crested side weirs. Through comparison of results of these equations and experimental data, good agreement was achieved. The mean and maximum relative errors of the discharge equation were -2.3% and 10.7%, respectively. © 2012 Elsevier B.V.

Ramli M.,Universiti Sains Malaysia
Construction and Building Materials | Year: 2012

This study was conducted to investigate the mechanical properties and the durability by using of different percentages of steel fibre with high strength flowing concrete (HSFC) and also the use of the hybridization of steel fibres, palm fibres and synthetic fibre (Barchip). Compressive strength, splitting tensile strength, flexural strength, static modulus of elasticity and permeability tests were determined after normal water curing and seawater exposure. The results show that the uses of 0.25-0.5% of the palm and Barchip fibres with 1.5-1.75% of steel fibre in HSFC mixes boost the best performance of compressive strength, splitting tensile strength, flexural strength among others. Besides, these percentages of fibres inclusions in HSFC were found to be effective when the HSFC exposed to seawater. © 2012 Elsevier Ltd. All rights reserved.

Lean H.H.,Universiti Sains Malaysia | Smyth R.,Monash University
Applied Energy | Year: 2010

This paper employs annual data from 1971 to 2006 to examine the causal relationship between aggregate output, electricity consumption, exports, labor and capital in a multivariate model for Malaysia. We find that there is bidirectional Granger causality running between aggregate output and electricity consumption. The policy implication of this result is that Malaysia should adopt the dual strategy of increasing investment in electricity infrastructure and stepping up electricity conservation policies to reduce unnecessary wastage of electricity, in order to avoid the negative effect of reducing electricity consumption on aggregate output. We also find support for the export-led hypothesis which states Granger causality runs from exports to aggregate output. This result is consistent with Malaysia pursuing a successful export-orientated strategy. © 2009 Elsevier Ltd. All rights reserved.

Zulkifle N.,Universiti Sains Malaysia
International Journal of Biological Chemistry | Year: 2013

Post-translational modification of proteins via ubiquitination is mediated by three enzyme families; El activating enzymes, E2 conjugating enzymes and E3 ligases, all of which work in a hierarchical manner to facilitate different forms of protein ubiquitin ranging from mono-ubiquitination to the formation of different forms of ubiquitin chains. Reversibly, deubiquitinating enzymes (DUBs) act to remove ubiquitin from modified substrates. Apart from the classic interactions within the E1-E2-E3 enzymatic cascade, an unusual non-hierarchical interaction has been observed between some E2 enzymes and a DUB called Otubain-1 (OTUB1). This observation raises interesting questions concerning the order and specificity within the human ubiquitin system. In this study, systematic yeast two-hybrid (Y2H) binary screen is performed between 39 E2 and 60 DUB proteins to analyze the extent of human E2-DUB interactions. As a result, putative partnerships between OTUB1 and UBE2D1, UBE2D2, UBE2D3, UBE2D4, UBE2E1, UBE2E2, UBE2E3 and UBE2N are identified and these data correlate well with data from other independent study by high-throughput Y2H library screen and mass spectrometry. In essence, this study confirmed that E2-DUB interactions within the human ubiquitin system are indeed uncommon and only unique to OTUB1 protein. © 2013 Academic Journals Inc.

Romano N.,James Cook University | Romano N.,Universiti Sains Malaysia | Zeng C.,James Cook University
Aquaculture | Year: 2012

Osmoregulation is an essential physiological process for the majority of aquatic crustaceans since it enables them to cope with the changes/discrepancies between the ion concentrations within their bodies and the aquatic environments they inhabit. With the exception of strict osmoconformers, crustaceans living in all aquatic environments continually regulate their hemolymph osmolytes and ultimately, the strategy and strength of this process dictate the diversity of habitats a crustacean can successfully occupy. While the degree of the osmoregulatory response is largely salinity dependent, the actual strength is highly species-specific. This has obvious and significant implications to the crustacean aquaculture industry, a multi-billion dollar industry that is continuously growing worldwide. Unfortunately, to date, a comprehensive review discussing the implications of this crucial process in crustaceans from an aquaculture perspective is lacking. Since crustacean aquaculture is almost exclusively based on large decapods, which also forms the main body of literature, they will therefore be the main focus of review. With basic background information on the regulatory mechanisms briefly described as a foundation for necessary knowledge, the implications of increased osmoregulatory demands to crustacean aquaculture is discussed extensively based on recent literature and research conducted in our laboratory. This includes the various factors that may influence osmoregulatory abilities, the causes leading to reduced productivity at sub-optimal salinities, potential methods that may broaden tolerable salinity ranges and how osmoregulation may interact with another important physiological process, i.e. ammonia excretion, which is crucial for cultured crustaceans. At the end of the review, future research directions are suggested to advance our understanding regarding this complex process that could substantially affect crustacean aquaculture productivity. © 2011 Elsevier B.V.

Nasir R.M.,Universiti Sains Malaysia
Procedia Engineering | Year: 2013

In this work, paddy straws and cockle shells were chosen due to their availability and potential as green composites after being harvested. The idea is that sustainability initiated from trash to treasure has given an impetus to utilise paddy straws and cockle shells to become useful composite fillers. Firstly, the collected paddy straws were cut into small sizes while cockle shells were crushed, blended and sieved before fabrication of the composite. The composite was prepared using a conventional compression molding. The specimen was tested under lubricated condition with different sliding speeds using the rotating pin-on-disc at constant applied load. In comparison, bio-shell composite has the least wear rate and coefficient of friction while pure polypropylene has the highest wear rate and coefficient of friction. The results show that with the addition of cockle shell powders or paddy straw, the wear rate and coefficient of friction of the material decreases with a minute degree of changes in their properties. Furthermore, the morphology of the tested specimens was also observed under a scanning electron microscopy (SEM) for better justification of the wear mechanism. © 2013 The Authors. Published by Elsevier.

Najafzadeh M.,Shahid Bahonar University of Kerman | Azamathulla H.M.,Universiti Sains Malaysia
Neural Computing and Applications | Year: 2013

In this study, group method of data handling network with quadratic polynomial was used to predict scour depth around bridge piers. Effective parameters on scour phenomena include sediment size, geometry of bridge pier, and upstream flow conditions. Different shapes of piers have been utilized to develop the GMDH network. Back propagation algorithm was performed to train the GHMD network which updated weighting coefficients of quadratic polynomial in each iteration of the training stage. The GMDH performed with the lowest errors of training and testing stages for cylindrical pier. Also, Richardson and Davis, Johnson's equations produced relatively good performances for different types of piers. Finally, the results indicated that GMDH could be provided more accurate prediction than those obtained using traditional equations. © 2012 Springer-Verlag London Limited.

Al-Heuseen K.,Al - Balqa Applied University | Hashim M.R.,Universiti Sains Malaysia
Sensors and Actuators, B: Chemical | Year: 2012

This paper reports the studies of Pd Schottky contact on porous n-GaN for hydrogen gas sensor. A simple conventional and low cost photoelectrochemical etching method was used to produce porous GaN with high uniformity. Hydrogen sensor was subsequently fabricated by depositing Pd Schottky contacts onto the porous GaN sample. For comparative study, a standard hydrogen sensor was also prepared by depositing Pd Schottky contacts on the as-grown sample. The Pd/porous GaN sensor exhibited a significant change of current upon exposure to different flow rates of 2% H 2 in N 2 gas as compared to the standard Pd/GaN sensor. The response increased exponentially with hydrogen flow rate for both sensors, but Pd/porous GaN is more sensitive to hydrogen than that of the as-grown GaN. The values of ideality factor (n), barrier height (φ B) and series resistance (R s) were calculated in both sensors. Barrier heights and series resistance decreased with H 2 flow rate while ideality factor increased. © 2012 Elsevier B.V. All rights reserved.

Ahmad K.A.,Universiti Sains Malaysia
International Journal of Mechanical and Materials Engineering | Year: 2011

This paper presents a numerical study of the effects of reduced frequency on the performance of an oscillating sub-boundary layer vortex generator. The numerical simulations were done using Fluent 6.3 and RANS equations were used to model the flow field induced by the vortex generator on a flat plate. A hybrid mesh with SST k-ω turbulence model was used during the computations. The undisturbed boundary layer thickness at the location of vortex generator was 80 mm and a vane-type VG with height of 40 mm was used. The flow Reynolds number based on the streamwise distance is 10 6. The VG was oscillated in a simple harmonic motion between 0° to 15° over a range of reduced frequency, F +. The increase in the spanwise averaged skin friction with the increase in reduced frequency is clearly observed. Furthermore, the time averaged skin friction distribution for oscillating SBVG is less spread compared to the static SBVG. The results also show that an increase in the reduced frequency induces secondary vortex to appear. The simulations result obtained are also found in satisfactory agreement with the experimental results.

Tan L.-L.,University of Selangor | Ong W.-J.,University of Selangor | Chai S.-P.,University of Selangor | Mohamed A.R.,Universiti Sains Malaysia
Applied Catalysis B: Environmental | Year: 2015

The design and architecture of visible-light-active photocatalysts is a key aim among material scientists for the efficient utilization of renewable solar energy. In this paper, a series of noble metal (Pt, Pd, Ag and Au) nanoparticles supported on reduced graphene oxide/TiO2 (GT) were successfully synthesized through a dual step process. In the first step, GT nanocomposites were prepared using a solvothermal method. The as-prepared hybrid nanostructures were subsequently employed as supporting materials for the dispersion of metal nanoparticles. A simple polyol process was used to respectively reduce metal ions (PtCl62-, Pd2+, Ag+, and AuCl4-) into metal (Pt, Pd, Ag and Au) nanoparticles on GT. The three-component nanocomposites exhibited enhanced photocatalytic activities toward the photoreduction of CO2 into CH4 gas under the irradiation of typical daylight bulbs. This was attributed to the multiplex phenomena such as an enhanced utilization of visible light, efficient electron transfer in the noble metal-doped GT nanojunctions and interfacial electron transfer in the reduced graphene oxide (rGO) sheets, as evidenced by UV-vis and PL characterizations. Among the noble metals studied, the Pt-doped GT nanocomposites showed the highest efficiency in reducing CO2. A total CH4 yield of 1.70μmol/gcat was achieved after 6h of light irradiation, which was 2.6 and 13.2 folds higher in comparison to GT and commercial P25, respectively. Based on the experimental results obtained, a plausible mechanism for the photocatalytic process associated with Pt-GT was proposed. © 2014 Elsevier B.V.

Ali Alsalihy W.A.H.,Universiti Sains Malaysia
International Journal of Advancements in Computing Technology | Year: 2011

Mobile Internet Protocol version 6 (MIPv6) is currently defined with a security solution called Return Routability that provides the Mobile node with an authentication mechanism and protects the BU signals between the Mobile node and the Correspondent node. MIPv6 also proposes the use of the Internet Protocol Security (IPSec) between the Mobile node and its Home Agent to protect the BU signals between them. While IPSec may offer strong protection, the use of IPSec with Return Routability does not necessarily cover all areas of security. Return Routability remains vulnerable to attacks. The main objective of this paper is to design a new security protocol to provide higher levels of authentication and security for MIPv6. This security protocol has to provide a level of security and authentication higher than exists in the current mechanism, Return Routability. Additionally, the new proposed security protocol will provide a consistent framework, replacing the comprehensive IPSec implementation within MIPv6. This proposed new security protocol is called Certification Authority Router's Certificate (CARC). CARC is successfully verified using the Murphi security protocol verifier.

Erejuwa O.O.,Universiti Sains Malaysia
International Journal of Molecular Sciences | Year: 2012

The primary aim of the current management of diabetes mellitus is to achieve and/or maintain a glycated hemoglobin level of ≤6.5%. However, recent evidence indicates that intensive treatment of hyperglycemia is characterized by increased weight gain, severe hypoglycemia and higher mortality. Besides, evidence suggests that it is difficult to achieve and/or maintain optimal glycemic control in many diabetic patients; and that the benefits of intensively-treated hyperglycemia are restricted to microvascular complications only. In view of these adverse effects and limitations of intensive treatment of hyperglycemia in preventing diabetic complications, which is linked to oxidative stress, this commentary proposes a hypothesis that "simultaneous targeting of hyperglycemia and oxidative stress" could be more effective than "intensive treatment of hyperglycemia" in the management of diabetes mellitus. © 2012 by the authors.

Md. Azamathulla H.,Universiti Sains Malaysia
Neural Computing and Applications | Year: 2013

This briefing article presents gene-expression programming (GEP), which is an extension to genetic programming, as an alternative approach to predict friction factor for Southern Italian rivers. Published data were compiled for the friction for 43 gravel-bed rivers of Calabria. The proposed GEP approach produces satisfactory results (R 2 = 0.958 and RMSE = 0.079) compared with existing predictors. © 2012 Springer-Verlag London Limited.

The effects of electron beam (EB) irradiation on the thermal properties, fatigue life and natural weathering of styrene butadiene rubber/recycled acrylonitrile-butadiene rubber (SBR/NBRr) blends were investigated. The SBR/NBRr blends were prepared at 95/5, 85/15, 75/25, 65/35, or 50/50 blend ratios with and without the presence of a 3part per hundred rubber (phr) of polyfunctional monomer, trimethylolpropane triacrylate (TMPTA). Results indicate that the crystallisation temperature (Tc) observed in polymeric blends is due to the alignment of polymer chains forming a semi-crystalline phase. Addition of TMPTA helps to align polymer chains through crosslinking. More crosslinking occurred between polymer blends with the help of TMPTA, upon irradiation. The improvement in fatigue life can also be associated with the stabilisation of SBR/NBRr blends upon irradiation and irradiation-induced crosslinking, which was accomplished with relatively low radiation-induced oxidative degradation in the presence of TMPTA. The tensile properties of both blends decreased over the periods of environmental exposure due to the effect of polymer degradation. After 6months, the irradiated SBR/NBRr blends could not retain better retention [mainly with 25, 35 or 50phr of recycled acrylonitrile-butadiene rubber (NBRr) particles] due to the samples becoming brittle over the long period of outdoor exposure. © 2011 Elsevier Ltd.

Kheng Yee O.,Duchess of Kent Hospital | Muhd Ramli E.R.,Taiping Hospital | Che Ismail H.,Universiti Sains Malaysia
Journal of Sexual Medicine | Year: 2014

Introduction: Despite the high prevalence of sexual dysfunction among male schizophrenia patients, there is still a paucity of research on this area. Aims: The study aims to determine the prevalence of sexual dysfunction and any association between male patients with schizophrenia in remission and the sociodemographic profile, medication, depression, anxiety, psychopathology of illness, body mass index, and waist circumference. Methods: A cross-sectional study with nonprobability sampling method was conducted in a psychiatric outpatient clinic in Taiping Hospital (Perak, Malaysia) over a 7-month period. A total of 111 remitted male schizophrenia patients were recruited. The validated Malay version of the International Index of Erectile Function (Mal-IIEF-15) was administered to the patients and assessed over 4-week duration in the domains of erectile function, orgasmic function, sexual desire, intercourse satisfaction, and overall satisfaction. Logistic regression analysis was employed. Main Outcome Measures: Prevalence and associated factors for sexual dysfunction in each domain are the main outcome measures. Results: All five domains of sexual functioning in patients showed a high prevalence of dysfunction ranging from 78.4% to 97.1% with orgasmic dysfunction being the least impaired and intercourse satisfaction the worst impaired. Among the domains, only orgasmic dysfunction was significantly associated with race, i.e., Chinese at lower risk for impairment than the Malays (OR=0.23; 95% CI: 0.07, 0.76; P=0.018); education, i.e., patients with education higher than primary level were at higher risk for dysfunction (OR=6.49; 95% CI: 1.32, 32.05; P=0.022); and Positive and Negative Syndrome Scale (PANSS)-positive subscale, i.e., higher PANSS-positive score was a protective factor for orgasmic dysfunction (OR=0.54; 95% CI: 0.33, 0.89; P=0.015). Conclusions: The prevalence of sexual dysfunction was generally high. Malay patients and those with education higher than primary level were at higher risk for orgasmic dysfunction whereas higher PANSS-positive score was protective against the impairment. The high rate of sexual dysfunction in schizophrenia patients warrants a routine inquiry into patients' sexuality and the appropriate problems being addressed. © 2013 International Society for Sexual Medicine.

Lean H.H.,Universiti Sains Malaysia | Smyth R.,Monash University
Applied Energy | Year: 2010

This study examines the causal relationship between carbon dioxide emissions, electricity consumption and economic growth within a panel vector error correction model for five ASEAN countries over the period 1980-2006. The long-run estimates indicate that there is a statistically significant positive association between electricity consumption and emissions and a non-linear relationship between emissions and real output, consistent with the environmental Kuznets curve. The long-run estimates, however, do not indicate the direction of causality between the variables. The results from the Granger causality tests suggest that in the long-run there is unidirectional Granger causality running from electricity consumption and emissions to economic growth. The results also point to unidirectional Granger causality running from emissions to electricity consumption in the short-run. © 2010 Elsevier Ltd. All rights reserved.

Mahalingam K.,Indian Institute of Technology Madras | Subramanian K.G.,Universiti Sains Malaysia
International Journal of Foundations of Computer Science | Year: 2012

The Parikh vector of a word enumerates the symbols of the alphabet that occur in the word. The Parikh matrix of a word which has been recently introduced, is an extension of the notion of Parikh vector and gives more numerical information about the word in terms of certain subwords. Intensive investigation on various theoretical properties of Parikh matrices has taken place. This paper deals with the problem of finding properties of words so that their Parikh matrices commute. © 2012 World Scientific Publishing Company.

Ahmad N.S.,Universiti Sains Malaysia | Carrasco J.,University of Manchester | Heath W.P.,University of Manchester
IEEE Transactions on Automatic Control | Year: 2015

Many conditions have been found for the absolute stability of discrete-time Lur'e systems in the literature. It is advantageous to find convex searches via LMIs where possible. In this technical note, we construct two less conservative LMI conditions for discrete-time systems with slope-restricted nonlinearities. The first condition is derived via Lyapunov theory while the second is derived via the theory of integral quadratic constraints (IQCs) and noncausal Zames-Falb multipliers. Both conditions are related to the Jury-Lee criterion most appropriate for systems with such nonlinearities, and the second generalizes it. Numerical examples demonstrate a significant reduction in conservatism over competing approaches. © 2015 IEEE.

Zyoud S.H.,Universiti Sains Malaysia | Al-Jabi S.W.,An Najah National University | Sweileh W.M.,An Najah National University | Morisky D.E.,University of California at Los Angeles
Health and Quality of Life Outcomes | Year: 2013

Background: The concepts of medication adherence and Treatment satisfactions are commonly used in clinical research for assessing pharmaceutical care and improving treatment outcomes. Generally, one would expect a positive relationship between the two concepts. The objectives of this study were to investigate the factors associated with adherence to antihypertensive therapy among hypertensive patients and to assess the relationship between antihypertensive medication adherence and treatment satisfaction.Methods: A cross-sectional study was conducted, adopting the Morisky eight-item Medication Adherence Scale (MMAS) for the assessment of medication adherence and using the Treatment Satisfaction Questionnaire for Medication (TSQM 1.4) for the assessment of treatment satisfaction. Descriptive and comparative statistics were used to describe socio-demographic and disease-related characteristics of the patients. All analyses were performed using SPSS v 15.0.Results: Four hundred and ten hypertensive patients were enrolled in the study. The mean age of participants was 58.38 ± 10.65 years; 52% were female and 36.8% had low antihypertensive medication adherence. There was a significant difference in the mean scores in the Effectiveness (p < 0.001), Convenience (p < 0.001), and Global Satisfaction (p < 0.001) domains, but not in the Side Effects (p = 0.466) domain among patients with different levels of adherence. After adjustment for covariates using multiple linear regression, global treatment satisfaction was still statistically significantly (p = 0.001) associated with medication adherence.Conclusions: Low treatment satisfaction may be an important barrier for achieving high rates of adherence to treatment. These study findings could be helpful in clinical practice, mainly in the early treatment of hypertensive patients, at a point where improving treatment satisfaction is still possible. © 2013 Zyoud et al.; licensee BioMed Central Ltd.

Emami A.,Universiti Sains Malaysia
Archives of dermatological research | Year: 2012

Keloid is a complex condition with environmental and genetic risk-contributing factors. Two candidate genes, TGFβ1 and SMAD4, located in the same signaling pathway are highly expressed in the keloid fibroblast cells. In a case-control design, TGFβ1 haplotypes showed association with the risk of keloid in the present study. The CC haplotype, composed of both c.29C>T and -509T>C variants, was observed more frequently among cases (Corrected p = 0.037, OR = 2.07, 95 % CI = 0.87-4.93), showing a 4.5-fold increased risk for keloid. The AG genotype of the SMAD4 c.5131A>G variant showed a trend of significance (p = 0.0573, OR = 1.75, 95 % CI = 0.99-3.13). Taken together, either of these variants is most probably causative at the expression level or is in linkage disequilibrium with other causative variants in a complex pattern together with the environmental factors that contribute to the condition. To the best of our knowledge, there is only one documented report on a relationship between TGFβ1 and keloid with no association within the Caucasian population, while there have not been any reports for SMAD4. Therefore, the present study is likely the first research showing a significant association between TGFβ1 variants and keloids in the Malay population.

Che Yaakob C.A.,Universiti Sains Malaysia
Cochrane database of systematic reviews (Online) | Year: 2010

BACKGROUND: Thromboembolic complications are much higher in pregnancy due to procoagulant changes. Heparin does not cross the placenta and the use of unfractionated heparin (UFH) is the current established practice in prophylaxis and treatment for thromboembolism in pregnancy. OBJECTIVES: To compare the effectiveness of anticoagulant therapies for the treatment of deep vein thrombosis in pregnancy. The anticoagulant drugs included are UFH, low molecular weight heparin (LMWH) and warfarin. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (March 2010) and reference lists of retrieved studies. SELECTION CRITERIA: Randomised controlled trials comparing any combination of warfarin, UFH, LMWH and placebo in pregnant women. DATA COLLECTION AND ANALYSIS: We used methods described in the Cochrane Handbooks for Systemic Reviews of Interventions for assessing the eligibility of studies identified by the search strategy. A minimum of two review authors independently assessed each study. MAIN RESULTS: We did not identify any eligible studies for inclusion in the review.We identified three potential studies; after assessing eligibility, we excluded all three as they did not meet the prespecified inclusion criteria. One study compared LMWH and UFH in pregnant women with previous thromboembolic events and, for most of these women, anticoagulants were used as thromboprophylaxis. There were only three women who had a thromboembolic event during the current pregnancy and it was unclear whether the anticoagulant was used as therapy or prophylaxis. We excluded one study because it included only women undergoing caesarean birth. The third study was not a randomised trial. AUTHORS' CONCLUSIONS: There is no evidence from randomised controlled trials on the effectiveness of anticoagulation for deep vein thrombosis in pregnancy. Further studies are required.

Abu Backer F.M.,Universiti Sains Malaysia
Infectious diseases in obstetrics and gynecology | Year: 2011

We studied the clinicopathological parameters of adenocarcinoma arising from endocervix (ECA) and from endometrium (EMA) based on the expression of P16ink4a, P21waf1, and p27Kip1 proteins. Immunohistochemistry was done on sections of confirmed ECA and EMA from hysterectomy specimens which have had no prior chemotherapy/radiotherapy. There were 40 ECAs and 92 EMAs. The mean age of ECA was 49.82 (SD 10.29); the youngest was 30 years old and the oldest 75 years old. The mean age of EMA was 54.45 (SD 10.92); the youngest was 30 years old and the oldest was 82 years old. For ECA, the size of the tumour is significantly associated with age and with depth of infiltration. FIGO stage is associated with histological grade. p21WAF1 expression is significantly associated with infiltration of the corpus and lymph node metastasis. p27Kip1 expression is significantly associated with lymph node invasion. The presence of lymph node metastasis is strongly associated when p16INK4a and p27Kip1 expressions are analyzed in combination. For EMA, p16INK4a expression is associated with histologic grade. Our study shows that we could use these cell cycle markers as predictors for more aggressive subsets of adenocarcinoma of the cervix and endometrium.

Lee C.-C.,Universiti Sains Malaysia | Neoh K.-B.,Kyoto University
Journal of Economic Entomology | Year: 2014

The efficacy of chitin synthesis inhibitors (CSIs) against fungus-growing termites is known to vary. In this study, 0.1% chlorfluazuron (CFZ) cellulose bait was tested against medium and large field colonies of Macrotermes gilvus (Hagen). The termite mounds were dissected to determine the health of the colony. Individual termites (i.e., workers and larvae) and fungus combs were subjected to gas chromatography-mass spectrometry (GC-MS) analysis to detect the presence of CFZ. In this study, 540.0 ± 25.8 g (or equivalent to 540.0 ± 25.8 mg active ingredient) and 680.0 ± 49.0 g (680.0 ± 49.0 mg active ingredient) of bait matrix were removed by the medium- and large-sized colonies, respectively, after baiting. All treated medium-sized colonies were moribund. The dead termites were scattered in the mound, larvae were absent, population size had decreased by 90%, and the queens appeared unhealthy. In contrast, no or limited effects were found in large-sized colonies. Only trace amounts of CFZ were detected in workers, larvae, and fungus combs, and the population of large-sized colonies had declined by only up to 40%. This might be owing to the presence of large amount of basidiomycete fungus and a drastic decrease of CFZ content per unit fungus comb (a main food source of larvae) in the large-sized colonies, and hence reduced the toxic effect and longer time is required to accumulate the lethal dose in larvae. Nevertheless, we do not deny the possibility of CSI bait eliminating or suppressing the higher termite if the test colonies could pick up adequate lethal dose by installing more bait stations and prolonging the baiting period. © 2014 Entomological Society of America.

Musa M.,Universiti Sains Malaysia
Malaysian Journal of Medical Sciences | Year: 2013

Immunology has now developed into an independent discipline in medicine which covers not only germ infection which is related to immunity solely but also covers a lot of non-infectious diseases such as autoimmune disease, allergies, and others. Therefore, "The Immune Mechanism: "A double-edged sword" means that the immune mechanism (consisted of antibody mediated mechanism and T cell mediated mechanism), just like one edge playing the role of giving benefit (immunity) as it destroys the agent of infection, and another one can be detrimental as it will cause tissue/cell damages and then give rise to immune diseases (immunopathology). Now, the prevalence of these immune diseases is on the rise and has become a new challenge to our country towards developed country in 2020. Therefore, we have to make ample preparation (laboratory facilities/services, main power, and research) from now on in order to face the problems and challenges. © Penerbit Universiti Sains Malaysia, 2013.

Mustafa F.H.,Hawler Medical University | Jaafar M.S.,Universiti Sains Malaysia
Indian Journal of Physics | Year: 2013

The determination of the penetration depth of laser light with different sources wavelengths into human skin is one of the preconditions of improving the photodynamic therapy (PDT) procedure for skin diseases. This research is planned to explore which wavelengths would be the most advantageous for use in PDT for superficial skin diseases, and to demonstrate that the red laser exposure of 635 nm wavelength is a suitable choice for all skin types in PDT. A realistic skin model (RSM) in the Advanced Systems Analysis Program (ASAP) software has been used to create different types of skin and to simulate laser sources with wavelengths of 635, 532, 405, 365, 308 and 295 nm. The penetration depths of different kinds of laser into the skin as well as their transmission have been calculated. Comparison of the depth of penetration of different wavelengths for all types of skin has been made. A large variation is found in the penetration depth of laser lights in all skin types. The transmission of lasers on the epidermis and dermis in different skin types occur, and the transmission dose changes significantly with the skin depths. The results of the present study provide a basis for understanding the penetration depth of laser in various skin colors and the responses of the skin to laser to improve dose-drug activation in PDT. The differences in spectral transmission between the red laser and the other lasers suggest that the red laser could be a suitable laser for all skin types. © 2012 Indian Association for the Cultivation of Science.

Heng M.H.,Universiti Sains Malaysia
Genetics and molecular research : GMR | Year: 2012

Fusarium species section Liseola namely F. fujikuroi, F. proliferatum, F. andiyazi, F. verticillioides, and F. sacchari are well-known plant pathogens on rice, sugarcane and maize. In the present study, restriction analysis of the intergenic spacer regions (IGS) was used to characterize the five Fusarium species isolated from rice, sugarcane and maize collected from various locations in Peninsular Malaysia. From the analysis, and based on restriction patterns generated by the six restriction enzymes, Bsu151, BsuRI, EcoRI, Hin6I, HinfI, and MspI, 53 haplotypes were recorded among 74 isolates. HinfI showed the most variable restriction patterns (with 11 patterns), while EcoRI showed only three patterns. Although a high level of variation was observed, it was possible to characterize closely related species and isolates from different species. UPGMA cluster analysis showed that the isolates of Fusarium from the same species were grouped together regardless of the hosts. We conclude that restriction analysis of the IGS regions can be used to characterize Fusarium species section Liseola and to discriminate closely related species as well as to clarify their taxonomic position.

Lok Y.Y.,Universiti Sains Malaysia | Merkin J.H.,University of Leeds | Pop I.,Babes - Bolyai University
International Journal of Thermal Sciences | Year: 2012

The steady mixed convection flow near an axisymmetric stagnation point on a stretching or shrinking vertical cylinder is considered. The equations for the fluid flow and temperature fields reduce to similarity form that involves a Reynolds number R, a mixed convection parameter λ, a parameter γ representing the motion of the cylinder and the Prandtl number σ. Numerical solutions of the similarity equations are obtained for representative values of these parameters, which show the existence of critical values λ c = λ c (R,γ,σ) with the existence of dual solutions in the opposing (λ < 0) case. The variation of the skin friction coefficient f″(1) and heat flux θ′(1) with λ and R when σ = 1.0 are shown graphically. Also variations of λ c with R, and γ are determined again in the case when σ = 1.0. It is found that in the aiding flow (λ > 0) case solutions are possible for all λ and the asymptotic solution in the limit λ → ∞ is obtained. The nature of the solution in the asymptotic limit of large values of R is also treated in the cases when λ is of O (1) and when λ is of O (R). © 2012 Elsevier Masson SAS. All rights reserved.

Ang W.L.,National University of Malaysia | Mohammad A.W.,National University of Malaysia | Hilal N.,University of Swansea | Leo C.P.,Universiti Sains Malaysia
Desalination | Year: 2015

Conventional processes involved in water treatment, either in water treatment plants or reverse osmosis desalination plants, have encountered several obstacles that have severely affected their performances and efficiencies. Pollution of natural water resources, increasing demand and overuse of clean water have all put critical stress on currently available conventional water treatment/desalination plants. Due to these problems, integrated/hybrid membrane processes have attracted much interest. An integrated/hybrid membrane system is a process which combines a membrane filtration unit (microfiltration/ultrafiltration/nanofiltration) with other processes such as coagulation, adsorption and ion exchange. Alternatively, it can be a combination of different membranes in the same system with a conventional process. The purpose of this paper is to review the applicability of integrated/hybrid membrane systems in water treatment plants and reverse osmosis desalination plants. The literature shows that many benefits and marked improvements could be achieved with integrated/hybrid membrane processes, such as enhanced quality of the water produced, energy savings, environmental friendliness, and reductions in the capital and operating costs of the plants. The implications of the integrated membrane system prove that it has huge potential to be widely applied and can lead to a breakthrough in solving the problem of water scarcity. © 2014 Elsevier B.V.

There is considerable evidence that emotional intelligence, previous academic achievement (i.e. cumulative grade point average (GPA)) and personality are associated with success in various occupational settings. This study evaluated the relationships of these variables with psychological health of first year medical students during stressful periods. A 1-year prospective study was done with students accepted into the School of Medical Sciences, Universiti Sains Malaysia. Information on emotional intelligence, GPA and personality traits were obtained prior to admission. The validated Universiti Sains Malaysia Emotional Quotient Inventory and Universiti Sains Malaysia Personality Inventory were used to measure emotional intelligence and personality traits, respectively. Stress, anxiety and depression were measured by the 21-item Depression Anxiety Stress Scale during the end-of-course (time 1) and final (time 2) examinations. At the less stressful period (time 1), stress level was associated with agreeableness and the final GPA, anxiety level was associated with emotional control and emotional conscientiousness and depression level was associated with the final GPA and extraversion. At the more stressful period (time 2), neuroticism associated with stress level, anxiety level was associated with neuroticism and emotional expression, and depression level was associated with neuroticism. This study found that neuroticism was the strongest associated factor of psychological health of medical students during their most stressful testing period. Various personality traits, emotional intelligence and previous academic performance were associated factors of psychological health during a less stressful period. These data suggest that early identification of medical students who are vulnerable to the stressful environment of medical schools might help them maintain psychological well-being during medical training.

Lee Y.Y.,Universiti Sains Malaysia | Erdogan A.,Georgia Regents University | Rao S.S.C.,Georgia Regents University
Journal of Neurogastroenterology and Motility | Year: 2014

Assessment of transit through the gastrointestinal tract provides useful information regarding gut physiology and pathophysiology. Although several methods are available, each has distinct advantages and limitations. Recently, an ingestible wireless motility capsule (WMC), similar to capsule video endoscopy, has become available that offers a less-invasive, standardized, radiation-free and office-based test. The capsule has 3 sensors for measurement of pH, pressure and temperature, and collectively the information provided by these sensors is used to measure gastric emptying time, small bowel transit time, colonic transit time and whole gut transit time. Current approved indications for the test include the evaluation of gastric emptying in gastroparesis, colonic transit in constipation and evaluation of generalised dysmotility. Rare capsule retention and malfunction are known limitations and some patients may experience difficulty with swallowing the capsule. The use of WMC has been validated for the assessment of gastrointestinal transit. The normal range for transit time includes the following: gastric emptying (2-5 hours), small bowel transit (2-6 hours), colonic transit (10-59 hours) and whole gut transit (10-73 hours). Besides avoiding the use of multiple endoscopic, radiologic and functional gastrointestinal tests, WMC can provide new diagnoses, leads to a change in management decision and help to direct further focused work-ups in patients with suspected disordered motility. In conclusion, WMC represents a significant advance in the assessment of segmental and whole gut transit and motility, and could prove to be an indispensable diagnostic tool for gastrointestinal physicians worldwide. © 2014 The Korean Society of Neurogastroenterology and Motility.

Qamaruz-Zaman N.,Universiti Sains Malaysia | Milke M.W.,University of Canterbury
Waste Management | Year: 2012

Research was conducted to determine suitable chemical parameters as indicators of odor from decomposing food wastes. Prepared food scraps were stored in 18. l plastic buckets (2. kg wet weight each) at 20. °C and 8. °C to reproduce high and low temperature conditions. After 1, 3, 7, 10 and 14. days of storage, the odor from the buckets were marked to an intensity scale of 0 (no odor) to 5 (intense) and the corresponding leachate analyzed for volatile fatty acids, ammonia and total organic carbon. A linear relationship between odor intensity and the measured parameter indicates a suitable odor indicator. Odor intensified with longer storage period and warmer surroundings. The study found ammonia and isovaleric acid to be promising odor indicators. For this food waste mixture, offensive odors were emitted if the ammonia and isovaleric acid contents exceeded 360. mg/l and 940. mg/l, respectively. © 2012 Elsevier Ltd.

Shahbaz M.,COMSATS Institute of Information Technology | Lean H.H.,Universiti Sains Malaysia | Shabbir M.S.,COMSATS Institute of Information Technology
Renewable and Sustainable Energy Reviews | Year: 2012

The paper is an effort to fill the gap in the energy literature with a comprehensive country study of Pakistan. We investigate the relationship between CO 2 emissions, energy consumption, economic growth and trade openness in Pakistan over the period of 1971-2009. Bounds test for cointegration and Granger causality approach are employed for the empirical analysis. The result suggests that there exists a long-run relationship among the variables and the Environmental Kuznets Curve (EKC) hypothesis is supported. The significant existence of EKC shows the country's effort to condense CO 2 emissions and indicates certain achievement of controlling environmental degradation in Pakistan. Furthermore, we find a one-way causal relationship running from economic growth to CO 2 emissions. Energy consumption increases CO 2 emissions both in the short and long runs. Trade openness reduces CO 2 emissions in the long run but it is insignificant in the short run. In addition, the change of CO 2 emissions from short run to the long span of time is corrected by about 10% yearly. © 2012 Elsevier Ltd. All rights reserved.

Othuman Mydin M.A.,Universiti Sains Malaysia
Jurnal Teknologi (Sciences and Engineering) | Year: 2013

Presently, the construction industry has shown considerable consciousness in utilizing lightweight foamcrete as a building material. The demand of lightweight foamcrete is becoming higher now where this material has increased many folds in recent years due to its intrinsic economies and advantages over conventional concrete in a range of structural and semi-structural applications. The major specialties of lightweight foamcrete are its excellent thermal conductivity, low self-weight, high impact resistance and good freeze thaw resistance. The aim of this experimental study is to investigate the thermal conductivity property of lightweight foamcrete with various densities. The main parameters that will be considered are density of lightweight foamcrete, the void size and porosity. The lightweight foamcrete samples are made with constant water-cement ratio of 0.5 and cement-sand ratio of 2:1. According to experimental results, lower densities lightweight foamcrete transforms to lower thermal conductivity values. Meanwhile, the density of lightweight foamcrete is controlled by the porosity where lower densities indicate larger porosity values. For this reason, thermal conductivity of lightweight foamcrete changes significantly with the porosity because air is the poorest conductor in comparison to solid and liquid owing its molecular constitution. The measured values of thermal conductivity should provide a useful database for evaluating the thermal performance of lightweight foamcrete structures. © 2013 Penerbit UTM Press. All rights reserved.

Ibrahim L.M.,Universiti Sains Malaysia
Journal of Engineering Science and Technology | Year: 2010

In this research, a hierarchical off-line anomaly network intrusion detection system based on Distributed Time-Delay Artificial Neural Network is introduced. This research aims to solve a hierarchical multi class problem in which the type of attack (DoS, U2R, R2L and Probe attack) detected by dynamic neural network. The results indicate that dynamic neural nets (Distributed Time-Delay Artificial Neural Network) can achieve a high detection rate, where the overall accuracy classification rate average is equal to 97.24%.© School of Engineering, Taylor?s University.

Tay K.M.,University Malaysia Sarawak | Lim C.P.,Universiti Sains Malaysia
Journal of Intelligent and Fuzzy Systems | Year: 2010

Traditional Failure Mode and Effect Analysis (FMEA) adopts the Risk Priority Number (RPN) ranking model to evaluate failure risks, to rank failures, as well as to prioritize actions. Although this approach is simple, it suffers from several shortcomings. In this paper, we investigate a number of fuzzy inference techniques for determining the RPN scores, in an attempt to overcome the weaknesses associated with the traditional RPN model. The main objective is to examine the possibility of using fuzzy rule interpolation and reduction techniques to design new fuzzy RPN models. The performance of the fuzzy RPN models is evaluated using a real-world case study pertaining to the test handler process in a semiconductor manufacturing plant. The FMEA procedure for the test handler is performed, and a fuzzy RPN model is developed. In addition, improvement to the fuzzy RPN model is proposed by refining the weights of the fuzzy production rules, hence a new weighted fuzzy RPN model. The ability of the weighted fuzzy RPN model in failure risk evaluation with a reduced rule base is also demonstrated. © 2010-IOS Press and the authors. All rights reserved.

Lim J.,Universiti Sains Malaysia | Lim J.,Carnegie Mellon University | Majetich S.A.,Carnegie Mellon University
Nano Today | Year: 2013

Iron oxide-gold nanoparticles that exhibit both magnetic and plasmonic behaviors have great potential for biomedical applications. The ability to remotely control the spatial position of a nanoparticle in real time while tracking its motion provides an exciting new tool for nanoscale sensing. In this review we summarize the major efforts in the design and synthesis of iron oxide-gold nanoparticles. The underlying magnetophoretic and plasmonic characteristics of gold and iron oxide nanoparticles that enable their use for biomedical applications are described. We discuss the challenges associated with the integration of iron oxide and gold in one unified nanostructure, including the chemical techniques involved in making such composite material. We emphasize on the importance of colloidal stability, and explain how this property determines the functionality of iron oxide-gold nanoparticles in physiological environment. Afterwards, we examine both the magnetophoresis and localized surface plasmon resonance of iron oxide-core gold-shell structure and provide theoretical explanations for these properties. Finally we suggest potential opportunities for use of iron oxide-gold nanoparticles. © 2013 Elsevier Ltd. All rights reserved.

Roy R.,Sher-e-Bangla Agricultural University | Chan N.W.,Universiti Sains Malaysia
Environmentalist | Year: 2012

The term 'indicator' is often vague and heterogeneous, and its dynamic characteristics make it highly variable over time and space. Based on reviews and synthesis, this study visualizes phenomena and highlights the trend of indicator selection criteria, development methods, validation evaluation strategies for improvement. In contextualization of the intensification of agriculture and climate change, we proposed a set of indicators for assessing agricultural sustainability in Bangladesh based on theoretically proposed and practically applied indicators by researchers. Also, this article raises several issues of indicator system development and presents a summary after due consideration. Finally, we underline multi-stakeholders' participation in agricultural sustainability assessment. © 2011 Springer Science+Business Media, LLC.

Mydin M.A.O.,Universiti Sains Malaysia
Journal of Engineering Science and Technology | Year: 2013

This paper reports the basis of one-dimensional Finite Difference method to obtain thermal properties of foamed concrete in order to solve transient heat conduction problems in multi-layer panels. In addition, this paper also incorporates the implementation of the method and the validation of thermal properties model of foamed concrete. A one-dimensional finite difference heat conduction programme has been developed to envisage the temperature development through the thickness of the foamed concrete slab, based on an initial estimate of the thermal conductivity-temperature relationship as a function of porosity and radiation within the voids. The accuracy of the model was evaluated by comparing predicted and experimental temperature profiles obtained from small scale heat transfer test on foamed concrete slabs, so that the temperature history of the specimen calculated by the programme closely matches those recorded during the experiment. Using the thermal properties of foamed concrete, the validated heat transfer program predicts foamed concrete temperatures in close agreement with experimental results obtained from a number of high temperature tests. The proposed numerical and thermal properties are simple yet efficient and can be utilised to aid manufacturers to develop their products without having to conduct numerous large-scale fire tests. © School of Engineering, Taylor's University.

Purpose - Visible and near infrared spectroscopy have been applied widely in fruits quality assessment especially on the measurement of soluble solids content (SSC) measured in °Brix and acidity measured in pH. Spectroscopy technique has been applied on three botanically different categories of fruits, that is: imported Californian table grape, Mandarin lime and star fruit. The purpose is to examine the ability of spectroscopy technique to quantify internal quality parameters with very narrow variability due to the characteristics of the raw material analyzed. This work also presents comparative study on peak wavelengths that can best be used to calibrate SSC and pH of different types of fruits. Design/methodology/approach - The effective wavelengths chosen for calibration development are compared with those selected by other researchers in similar experiments. NIR wavelengths 910 nm (C-H band) and 950?nm (O-H band) are the most important wavelengths for the prediction of SSC for all examined fruits while wavelengths 922-923 nm and 990-995 nm for pH. Visible wavelength 605, 675 and 654?nm can efficiently improve the SSC and pH prediction for grape, lime and star fruit, respectively. Findings - The best prediction for SSC has been achieved with R2 = 0.953 and RMSE=0.182 for grape, R2 = 0.918 and RMSE = 0.109 for lime and R2 = 0.957 and RMSE=0.354 for star fruit. The best prediction for pH has been achieved with R2 = 0.763 and RMSE=0.110 for grape, R2 = 0.841 and RMSE=0.073 for lime and R2 = 0.862 and RMSE = 0.261 for star fruit. Originality/value - Currently, the spectroscopy research conducted for the measurement of fruits qualities is conducted through wide range spectrometer. However, the peak responses are only located at specific wavelengths. Hence, the selection of wavelengths related to SSC and pH will allow the design of low cost instruments for the prediction of these internal quality parameters. © Emerald Group Publishing Limited.

Sankar D.S.,Universiti Sains Malaysia
International Journal of Non-Linear Mechanics | Year: 2011

The pulsatile flow of a two-phase model for blood flow through axisymmetric and asymmetric stenosed narrow arteries is analyzed, treating blood as a two-phase model with the suspension of all the erythrocytes in the core region as the HerschelBulkley material and plasma in the peripheral layer as the Newtonian fluid. The perturbation method is applied to solve the resulting non-linear implicit system of partial differential equations. The expressions for various flow quantities are obtained. It is found that the pressure drop, plug core radius, wall shear stress increase as the yield stress or stenosis height increases. It is noted that the velocity increases, longitudinal impedance decreases as the amplitude increases. For asymmetric stenosis, the wall shear stress increases non-linearly with the increase of the axial distance. The estimates of the increase in longitudinal impedance to flow of the two-phase HerschelBulkley material are significantly lower than those of the single-phase HerschelBulkley material. The results show the advantages of two-phase flow over single-phase flow in small diameter arteries with stenosis. © 2010 Elsevier Ltd. All rights reserved.

Chan K.W.,Universiti Sains Malaysia | McCulloch M.,University of Oxford
International Journal of Refrigeration | Year: 2013

Bubble pump (BP), an essential component in coffee percolators, is used to drive solar water heating systems and single pressure absorption refrigerators. However, its mass flow rate cannot be readily predicted. Heat input, tube diameter and submergence ratio affect its mass flow rate. BP has the same working concept as air-lift pump, but its flow is complicated due to the condensation of vapour bubbles. Neither curve fitting models, nor air-lift pump models, can predict the mass flow rate with high fidelity. A new model based on the pumping characteristics of BP is presented and verified by a water based setup at atmospheric pressure. Results show that the average errors for the BP with tube diameter of 6-12 mm, and for the BP with submergence ratio of 0.5-0.8 are 13% and 11%, respectively. The BP performance increases when the tube diameter decreases or the submergence ratio increases. © 2013 Elsevier Ltd and IIR. All rights reserved.

Ahmad S.,Universiti Sains Malaysia | Pop I.,Technical University of Cluj Napoca
International Communications in Heat and Mass Transfer | Year: 2010

The steady mixed convection boundary layer flow past a vertical flat plate embedded in a porous medium filled with nanofluids is studied using different types of nanoparticles as Cu (cuprom), Al2O3 (aluminium) and TiO2 (titanium). The model used for the nanofluid is the one which incorporates only the nanoparticle volume fraction parameter. The basic partial equations are reduced to an ordinary differential equation which is solved numerically for some values of the volume fraction and mixed convection parameters. It is shown that the solution has two branches in a certain range of the parameters. The effects of these parameters on the velocity distribution are presented graphically. © 2010 Elsevier Ltd.

Yusoff M.S.B.,Universiti Sains Malaysia
International Medical Journal | Year: 2011

Objective: To determine the construct validity and the internal consistency of the Malay version Brief COPE among secondary school adolescents hence in the future it could be used as a valid and reliable instrument to identify their coping strategies Methods: The original Brief COPE was translated into Malay language by previous study. It comprised of 28 items with 14 coping strategies. It was administered to a total of 100 secondary school adolescents. Data was analysed using Statistical Package Social Sciences (SPSS) version 12. Factor analysis was applied to test construct validity of the Malay Brief COPE. Reliability analysis was applied to test internal consistency of the Malay Brief COPE. Results: 90 participants participated in this study. The total Cronbach's alpha value of the Malay version Brief COPE was 0.83. Most of the coping strategies showed acceptable internal consistency as having Cronbach's alpha values more than 0.5. Most of the items were loaded nicely according to the coping strategies. Conclusion: This study showed that the Malay Brief COPE had good psychometric value. It is a valid and reliable instrument in identifying coping strategies of secondary school adolescent. © 2011 Japan International Cultural Exchange Foundation.

Introduction: Studies investigating the efficacy of interventions for improving treatment non-adherence in schizophrenia have generated contrasting findings. The present review examined psychosocial interventions for improving medication adherence and prevention of relapse among patients with schizophrenia in developing countries in the Asia-Pacific. Methods: The relevant literature and systematic review were identified by computerized searches using keywords, and hand-searched for other selected articles. Results: The reasons for poor medication adherence were complex and heterogenous. Psychoeducation programs alone are ineffective in achieving good medication adherence because they do not lead to attitudinal and behavioral changes. The greatest improvement in adherence was seen with interventions employing a combination of educational, behavioral and cognitive strategies. Unfortunately, few relevant studies from this region were found. There were some interventions related to psychoeducation and compliance therapy (CT) that were successfully conducted by nurses. Patients in developing countries generally had better family support, but strong stigma towards mental illness and interference by traditional healers led to poor treatment adherence. Lack of facilities and shortage of medical professionals aggravated the situation. Discussion: Intervention to improve treatment adherence and prevention of relapse among patients with schizophrenia should be incorporated into existing psychiatric services. Adherence to treatment in patients with schizophrenia could be improved if continuously supported and monitored by caregivers and treating doctors, to facilitate a change in the patient's attitude. Paramedical personnel, such as psychiatric nurses, could be actively involved in intervention programs because of the shortage of medical professionals in this region. © 2010 Blackwell Publishing Asia Pty Ltd.

Foo K.Y.,Universiti Sains Malaysia
Bioresource technology | Year: 2012

Microwave heating was used in the regeneration of methylene blue-loaded activated carbons produced from fibers (PFAC), empty fruit bunches (EFBAC) and shell (PSAC) of oil palm. The dye-loaded carbons were treated in a modified conventional microwave oven operated at 2450 MHz and irradiation time of 2, 3 and 5 min. The virgin properties of the origin and regenerated activated carbons were characterized by pore structural analysis and nitrogen adsorption isotherm. The surface chemistry was examined by zeta potential measurement and determination of surface acidity/basicity, while the adsorptive property was quantified using methylene blue (MB). Microwave irradiation preserved the pore structure, original active sites and adsorption capacity of the regenerated activated carbons. The carbon yield and the monolayer adsorption capacities for MB were maintained at 68.35-82.84% and 154.65-195.22 mg/g, even after five adsorption-regeneration cycles. The findings revealed the potential of microwave heating for regeneration of spent activated carbons. Copyright © 2012 Elsevier Ltd. All rights reserved.

As a topical delivery system, a nanoscaled emulsion is considered a good carrier of several active ingredients that convey several side effects upon oral administration, such as nonsteroidal anti-inflammatory drugs (NSAIDs). We investigated the in vitro permeation properties and the in vivo pharmacodynamic activities of different nanoscaled emulsions containing ibuprofen, an NSAID, as an active ingredient and newly synthesized palm olein esters (POEs) as the oil phase. A ratio of 25:37:38 of oil phase:aqueous phase:surfactant was used, and different additives were used for the production of a range of nanoscaled emulsions. Carbopol® 940 dispersion neutralized by triethanolamine was employed as a rheology modifier. In some circumstances, menthol and limonene were employed at different concentrations as permeation promoters. All formulae were assessed in vitro using Franz diffusion cell fitted with full-thickness rat skin. This was followed by in vivo evaluation of the anti-inflammatory and analgesic activities of the promising formulae and comparison of the effects with that of the commercially available gel. Among all other formulae, formula G40 (Carbopol® 940-free formula) had a superior ability in transferring ibuprofen topically compared with the reference. Carbopol® 940 significantly decreased the amount of drug transferred from formula G41 through the skin as a result of swelling, gel formation, and reduction in drug thermodynamic activity. Nonetheless, the addition of 10% w/w of menthol and limonene successfully overcame this drawback since, relative to the reference, higher amount of ibuprofen was transferred through the skin. By contrast, these results were relatively comparable to that of formula G40. Pharmacodynamically, the G40, G45, and G47 formulae exhibited the highest anti-inflammatory and analgesic effects compared with other formulae. The ingredients and the physical properties of the nanoscaled emulsions produced by using the newly synthesized POEs succeeded to deliver ibuprofen competently.

Sasongko T.H.,Universiti Sains Malaysia
The Cochrane database of systematic reviews | Year: 2013

Sickle cell disease is a group of disorders characterized by deformation of erythrocytes. Renal damage is a frequent complication in sickle cell disease as a result of long-standing anemia and disturbed circulation through the renal medullary capillaries. Due to the improvement in life expectancy of people with sickle cell disease, there has been a corresponding significant increase in the incidence of renal complications. Microalbuminuria and proteinuria are noted to be a strong predictor of subsequent renal failure. There is extensive experience and evidence with angiotensin-converting enzyme (ACE) inhibitors over many years in a variety of clinical situations for patients who do not have sickle cell disease, but their effect in patients with this disease is unknown. It is common practice to administer ACE inhibitors for sickle nephropathy due to their renoprotective properties; however, little is known about their effectiveness and safety in this setting. To determine the effectiveness of ACE inhibitor administration in people with sickle cell disease for decreasing intraglomerular pressure, microalbuminuria and proteinuria and to to assess the safety of ACE inhibitors as pertains to their adverse effects. The authors searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Hameoglobinopathies Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings.Date of the most recent search: 05 July 2012. Randomized or quasi-randomized controlled trials of ACE inhibitors designed to reduce microalbuminuria and proteinuria in people with sickle cell disease compared to either placebo or standard treatment regimen. Three authors independently applied the inclusion criteria in order to select studies for inclusion in the review. Two authors assessed the risk of bias of studies and extracted data and the third author verified these assessments. Five studies were identified through the searches, only one met our inclusion criteria. The included study randomized 22 participants (7 males and 15 females) having proteinuria or microalbuminuria with sickle cell disease and treated the participants for six months (median length of follow-up of three months) with captopril or placebo. At six months, the study reported no significant difference in urinary albumin excretion between the captopril group and the placebo group, although the mean urinary albumin excretion in the captopril group was lower by a mean difference of -49.00 (95% confidence interval -124.10 to 26.10) compared to that of placebo. However, our analysis on the absolute change score showed significant changes between the two groups by a mean difference of -63.00 (95% confidence interval -93.78 to -32.22). At six months albumin excretion in the captopril group was noted to decrease from baseline by a mean of 45 ± 23 mg/day and the placebo group was noted to increase by 18 ± 45 mg/day. Serum creatinine and potassium levels were reported constant throughout the study. The potential for inducing hypotension should be highlighted; the study reported a decrease of 8 mmHg in systolic pressure and 5 mmHg in diastolic and mean blood pressure. There is not enough evidence to show that the administration of ACE inhibitors is associated with a reduction of microalbuminuria and proteinuria in people with sickle cell disease, although a potential for this was seen. More long-term studies involving multiple centers and larger cohorts using a randomized-controlled design are warranted, especially among the pediatric age group. Detailed reporting of each outcome measure is necessary to allow a clear cut interpretation in a systematic review. One of the difficulties encountered in this review was the lack of detailed data reported in the included study.

Khodarahimi S.,Universiti Sains Malaysia
International Forum of Psychoanalysis | Year: 2010

Symbols psychoanalysis, depth psychology, mythology and religion from a multiplicity of perspectives - there are many guidelines for their interpretation and integration in clinical practice. The present study, based on a Jungian analytic model, incorporated the snake mother as an imaginary symbol in a patient with generalised anxiety disorder and her treatment within a clinical case study. From an integrative symbolism approach, snakes are considered mysterious, with the ability to express the primary instinctual powers and psychic energy that take root beyond the ego strength and archetypal images. Here, with respect to the patient's main complaint and her underlying core conflict according to Jungian therapy and Persian mythology, it was indicated that the snake mother symbolism, an imagery object from childhood to adolescence, originated from both the personal and the collective unconsciousness. The way in which the symbolism of the snake mother came to work in the therapeutic process was similar to a that of dream and symbolism approach. The snake mother operated as an alternative animus in the shape of a caregiving mother, and supported the patient against her father's misbehavior during her early childhood. It could represent the shadow, the reconsolidation of the anima/animus for patient, and a projection of negative thoughts and actions from animal instincts. © 2010 Taylor & Francis.

Inhaled corticosteroids provide unique systems for local treatment of asthma or chronic obstructive pulmonary disease. However, the use of poorly soluble drugs for nebulization has been inadequate, and many patients rely on large doses to achieve optimal control of their disease. Theoretically, nanotechnology with a sustained-release formulation may provide a favorable therapeutic index. The aim of this study was to determine the feasibility of using sterically stabilized phospholipid nanomicelles of budesonide for pulmonary delivery via nebulization. PEG(5000)-DSPE polymeric micelles containing budesonide (BUD-SSMs) were prepared by the coprecipitation and reconstitution method, and the physicochemical and pharmacodynamic characteristics of BUD-SSMs were investigated. The optimal concentration of solubilized budesonide at 5 mM PEG(5000)-DSPE was 605.71 ± 6.38 μg/mL, with a single-sized peak population determined by photon correlation spectroscopy and a particle size distribution of 21.51 ± 1.5 nm. The zeta potential of BUD-SSMs was -28.43 ± 1.98 mV. The percent entrapment efficiency, percent yield, and percent drug loading of the lyophilized formulations were 100.13% ± 1.09%, 97.98% ± 1.95%, and 2.01% ± 0.02%, respectively. Budesonide was found to be amorphous by differential scanning calorimetry, and had no chemical interaction with PEGylated polymer according to Fourier transform infrared spectroscopy. Transmission electron microscopic images of BUD-SSMs revealed spherical nanoparticles. BUD-SSMs exhibited prolonged dissolution behavior compared with Pulmicort Respules (P < 0.05). Aerodynamic characteristics indicated significantly higher deposition in the lungs compared with Pulmicort Respules. The mass median aerodynamic, geometric standard deviation, percent emitted dose, and the fine particle fraction were 2.83 ± 0.08 μm, 2.33 ± 0.04 μm, 59.13% ± 0.19%, and 52.31% ± 0.25%, respectively. Intratracheal administration of BUD-SSMs 23 hours before challenge (1 mg/kg) in an asthmatic/chronic obstructive pulmonary disease rat model led to a significant reduction in inflammatory cell counts (76.94 ± 5.11) in bronchoalveolar lavage fluid compared with administration of Pulmicort Respules (25.06 ± 6.91). The BUD-SSMs system might be advantageous for asthma or chronic obstructive pulmonary disease and other inflammatory airway diseases.

Adsorption capacity of Cr(VI) onto chitosan coated with poly 3-methyl thiophene synthesized chemically was investigated in a batch system by considering the effects of various parameters like contact time, initial concentration, pH and temperature. Cr(VI) removal is pH dependent and found to be maximum at pH 2.0. Increases in adsorption capacity with increase in temperature indicate that the adsorption reaction is endothermic. Based on this study, the thermodynamic parameters like standard Gibb's free energy (Δ G°), standard enthalpy (Δ H°) and standard entropy (Δ S°) were evaluated. Adsorption kinetics of Cr(VI) ions onto chitosan coated with poly 3-methyl thiophene were analyzed by pseudo-first-order and pseudo-second-order models. The Langmuir, Freundlich and Temkin isotherms were used to describe the adsorption equilibrium studies of chitosan coated with poly 3-methyl thiophene at different temperatures. Langmuir isotherm shows better fit than Freundlich and Temkin isotherms in the temperature range studied. The results show that the chitosan coated with poly 3-methyl thiophene can be efficiently used for the treatment of wastewaters containing chromium as a low cost alternative compared to commercial activated carbon and other adsorbents reported. In order to find out the possibility of regeneration and reuse of exhausted adsorbent, desorption studies were also performed. © 2010 Elsevier B.V.

Anabas testudineus (Anabantidae) is an important food fish in Southeast Asia. We analyzed the mitochondrial DNA control region sequence data to evaluate the genetic variability and population structure of this species. Sixty specimens were collected from four populations in Sumatra and two populations in Peninsular Malaysia. We found a very low level of genetic variability, with five of the six populations exhibiting total absence of genetic variation. Based on analysis of molecular variance, 84.72% of the total variation was among populations and 15.28% within populations. A geographical division based on FST values indicated highly significant genetic differentiation among populations from the four drainage systems: Aceh, Sumatra Utara, Pulau Pinang, and Terengganu (FST ranging from 0.633 to 1.000). No phylogeographic relationships among populations were detected, despite the generation of four distinct clades in a neighbor-joining phylogenetic tree.

Shafie A.A.,Universiti Sains Malaysia
Quality of life research : an international journal of quality of life aspects of treatment, care and rehabilitation | Year: 2011

The objective of this study was to assess the construct validity of the EQ-5D instrument among the Malaysian population. This was a cross-sectional study conducted among Malaysian adults in three northern states of Malaysia. A pre-developed questionnaire consisting of both the EQ-5D and SF-12 items was used for data collection. Concurrent, convergent, and known group validity of EQ-5D were assessed against SF-12 and several known relationships with participants' demographic and illness characteristics. A total of 596 Malaysians participated in the study. The mean EQ-5D score was 0.93 (SD = 0.13), while the mean physical component score (PCS-12) and mental component score (MCS-12) scores were 48.9 (SD = 7.4) and 49.1 (SD = 8.0), respectively. Participants with a current medical problem had lower PCS-12 and MCS-12 scores and reported more problems with all of the EQ-5D dimensions; they also had lower EQ-5D and EQ-VAS scores (P < 0.05). Convergent validity was supported by a moderately positive correlation between EQ-5D and EQ-VAS with MCS-12 and PCS-12 scores; moreover, the stronger effect sizes between PCS-12 and the physical dimensions of EQ-5D as well as between MCS-12 with anxiety/depression scores further supported the convergent validity of EQ-5D. Responses to the EQ-5D dimensions only supported two of the four known group validity hypotheses of higher quality of life among individuals who are better educated and no medical problem. No association was found between income and gender with EQ-5D score. This study has demonstrated acceptable construct validity of the EQ-5D among the Malaysian population.

Kabilan M.K.,Universiti Sains Malaysia | Khan M.A.,University of Dhaka
Computers and Education | Year: 2012

Assessment in learning is always of interest to practitioners, academics and researchers, and is always evolving with new implications. Alternative forms of assessment such as e-portfolios have gained recognition in documenting students' learning, as it is synchronous with both product and process. Vast amount of literature narrates the relative advantages of e-portfolios across disciplines, institutions, and applications. In Malaysia, such alternative assessment practices are less explored so far in teacher education. In this study, 55 pre-service TESOL teachers from Universiti Sains Malaysia (USM) are required to create and maintain a personal e-portfolio. The aim of the study is to ascertain the future teachers' practices with e-portfolios in their learning and to determine if these practices lead to teaching competencies. In addition, the study also aims to identify the benefits and challenges of using an e-portfolio as a tool for learning and self-assessment. Findings indicate that participants are appreciative of e-portfolios, as their performance and achievements are traced over time. It is also found that e-portfolios function as a monitoring tool, which helps the teachers recognize their learning and identify their strengths and weaknesses. Challenges are also noted, which include validity and reliability, interrupted Internet connection, negative attitudes participants, time constraints, workload and ethical issues. In terms of teacher competencies, it is found that six competencies emerge from the teachers' practices of e-portfolios - (1) developing understanding of an effective teacher's role; (2) developing teaching approaches/activities; (3) improving linguistic abilities; (4) comprehending content knowledge; (5) gaining ICT skills and; (6) the realization of the need to change mindsets. © 2012 Elsevier Ltd. All rights reserved.

Ahmad S.,Universiti Sains Malaysia | Rohni A.M.,Northern University of Malaysia | Pop I.,Technical University of Cluj Napoca
Acta Mechanica | Year: 2011

The classical problems of forced convection boundary layer flow and heat transfer past a semi-infinite static flat plate (Blasius problem) and past a moving semi-infinite flat plate (Sakiadis problem) using nanofluids are theoretically studied. The similarity equations are solved numerically for three types of metallic or nonmetallic nanoparticles such as copper (Cu), alumina (Al2O3), and titania (TiO2) in the base fluid of water with the Prandtl number Pr = 6.2 to investigate the effect of the solid volume fraction parameter φ of the nanofluids. Also, the case of conventional or regular fluid (φ = 0) with Pr = 0.7 is considered for comparison with known results from the open literature. The comparison shows excellent agreement. The skin friction coefficient, Nusselt number, and the velocity and temperature profiles are presented and discussed in detail. It is found that the solid volume fraction affects the fluid flow and heat transfer characteristics. © 2010 Springer-Verlag.

Iqbal S.,Universiti Sains Malaysia | Besar R.,Multimedia University | Venkataseshaiah C.,Multimedia University
Journal of Instrumentation | Year: 2010

This paper proposes a dual-mode phase-shift modulation control scheme for series resonant inverter fed voltage multiplier (VM) based X-ray power supply. In this control scheme the outputs voltage of two parallel connected series resonant inverters are mixed before supplying to VM circuit. The output voltage of the power supply is controlled by varying the phase-shift between the output voltages of two inverters. In order to achieve quick rise of output voltage, the power supply is started with zero phase-shift and as the output voltage reaches 90% of the target voltage, the phase-shift is increased to a value which corresponds to target output voltage to prevent overshoot. The proposed control scheme has been shown to have good performance. Experimental results based on the scaled-down laboratory prototype are presented to validate the effectiveness of proposed dual-mode phase shift modulation control scheme. © 2010 IOP Publishing Ltd and SISSA.

Bhat R.,Universiti Sains Malaysia
International Journal of Food Properties | Year: 2013

Fourier transform infrared spectroscopy is considered as a rapid, non-destructive, reliable, sensitive, and cost-effective technique, which could be used for characterizing the chemical composition (identifying functional groups) of various microorganisms. In the present study, Fourier transform infrared spectroscopy was employed to differentiate (based on functional groups; spectral range between 3500-500 cm-1) between different genera of fungi (mainly Aspergillus sp. and Mucor sp.), capable of producing mycotoxins. From the results, it was clearly evident that irrespective of the overall similarities between the spectra of different fungi, there is a unique spectrum for each one with precise differences in the functional groups. These results can be useful and provide a suitable "finger print" for each of the fungal strains capable of producing mycotoxins. This method of differentiating between toxigenic fungi can also be effectively used in assisting quarantine rules. The results obtained in this study revealed Fourier transform infrared spectroscopy to show great potential for identification of molds capable of producing mycotoxins. © 2013 Copyright Taylor and Francis Group, LLC.

Yusoff M.S.B.,Universiti Sains Malaysia
International Medical Journal | Year: 2013

Objective: This study aimed to determine the construct validity, internal consistency and normative data of the DASS-21 among the applicants. Method: A cross-sectional study was done on two cohorts of applicants to a public medical school. A total of 839 applicants were invited to participate in the study. The DASS-21 was administered to the applicants after they completed interviews. The confirmatory factor analysis and reliability analysis were done by AMOS version 19 and SPSS version 18 to assess construct validity and internal consistency. Result: Approximately 706 (84.1%) applicants completely responded to all statements of the DASS-21. The Cronbach's alpha values of the DASS-21 subscales ranged between 0.63 and 0.67 with the overall value of 0.82. The three-factors with 7-item model of the DASS-21 were not the best fit model. The three-factors with 4-item and 3-item models were found to be the best fit model. The Cronbach's alpha values for each subscale of the new models ranged between 0.52 and 0.59 with overall values in between 0.72 and 0.76. The normative data of DASS-21 scores found for the applicants was different from previous studies. Conclusion: This study support validity and reliability of the three-factor constructs of the DASS to measure depression, anxiety and stress symptoms among medical course applicants. The DASS-12 and DASS-9 demonstrated better psychometric values than the DASS-21. Continued research is required to refine validity and reliability as well as to optimise role and usefulness of the shorter versions of DASS as psychological health screening tool for medical schools. © 2013 Japan International Cultural Exchange Foundation and Japan Health Sciences University.

Zyoud S.H.,Universiti Sains Malaysia | Al-Jabi S.W.,Community Pharmacy | Sweileh W.M.,An Najah National University
Tobacco Induced Diseases | Year: 2014

Background: Waterpipe tobacco smoking has spread worldwide. However, the evaluation of scientific output in the field of waterpipe tobacco smoking has not been studied yet. The main objectives of this study were to analyze worldwide research output in the waterpipe tobacco smoking field, and to examine the authorship pattern and the citations retrieved from the Scopus database for over a decade. Methods. Data from January 1, 2003 through December 31, 2012 were searched for documents with specific words regarding waterpipe tobacco smoking as "keywords" in the title. Scientific output was evaluated based on a methodology developed and used in other bibliometric studies: (a) total and trends of contributions in waterpipe tobacco smoking research between 2003 and 2012; (b) authorship patterns and research productivity; (c) collaboration patterns; (d) the citations received by the publications; and (e) areas of interest of the published papers. Results: Worldwide there were 334 publications that met the criteria during the study period. The largest number of publications in waterpipe tobacco smoking were from the United States of America (USA) (33.5%), followed by Lebanon (15.3%), and France (10.5%). The total number of citations at the time of data analysis (October 18, 2013) was 4,352, with an average of 13 citations per document and a median (interquartile range) of 4.0 (1.0-16.0). The h-index of the retrieved documents was 34. The highest h-index by country was 27 for the USA, followed by 20 for Syrian Arab Republic and Lebanon. Conclusions: The present data reveal a promising rise and a good start for research activity in the field of waterpipe tobacco smoking. More effort is needed to bridge the gap in waterpipe smoking-based research and to promote better evaluation of waterpipe smoking, risks, health effects, or control services worldwide. © 2014 Zyoud et al.; licensee BioMed Central Ltd.

Lok Y.Y.,Universiti Sains Malaysia | Pop I.,Babes - Bolyai University
Meccanica | Year: 2014

A detailed study of the problem of unsteady separated stagnation-point flow toward a stretching or shrinking sheet is presented. By use of a similarity transformation, the partial differential equations are reduced to a system of ordinary differential equations which are then solved numerically by use of the collocation method. The bvp4c Matlab program is used to perform the computation. This method is capable of finding multiple solutions for the flow reattachment case. The streamlines of the separation flow are presented for the cases when the origins of the stagnation flow and the stretching sheet are aligned and non-aligned. Comparison with results from the open literature reveals excellent agreement. © Springer Science+Business Media Dordrecht 2014.

Zyoud S.H.,Universiti Sains Malaysia | Al-Jabi S.W.,Community Pharmacy | Sweileh W.M.,An Najah National University
BMC Public Health | Year: 2014

Background: Electronic cigarette (EC) is an emerging phenomenon that is becoming increasingly popular with smokers worldwide. There is a lack of data concerning the evaluation of research productivity in the field of EC originating from the world. The main objectives of this study were to analyse worldwide research output in EC field, and to examine the authorship pattern and the citations retrieved from the Scopus database. Methods. Data were searched for documents with specific words regarding EC as "keywords" in the title. Scientific output was evaluated based on the methodology developed and used in other bibliometric studies by investigation: (a) total and trends of contributions in EC research during all previous years up to the date of data analysis (June 13, 2014); (b) authorship patterns and research productivity; (c) countries contribution; and (d) citations received by the publications. Results: Three hundred and fifty-six documents were retrieved comprising 31.5% original journal articles, 16% letters to the editor, 7.9% review articles, and 44.6% documents that were classified as other types of publications, such as notes or editorials or opinions. The retrieved documents were published in 162 peer-reviewed journals. All retrieved documents were published from 27 countries. the largest number of publications in the field of EC was from the United States of America (USA); (33.7%), followed by the United Kingdom (UK); (11.5%), and Italy (8.1%). The total number of citations at the time of data analysis was 2.277, with an average of 6.4 citations per document and median (interquartile range) of 0.0 (0.0-5.0). The h-index of the retrieved documents was 27. The most productive institutions were Food and Drug Administration, USA (4.2% of total publications) followed by Universita degli Studi di Catania, Italy (3.9%), University of California, San Francisco, USA (3.7%). Conclusions: This bibliometric study is a testament to the progress in EC research from the world over the last few years. More effort is needed to bridge the gap in EC-based research and to promote better evaluation of EC, risks, health effects, or control services worldwide. © 2014 Zyoud et al.; licensee BioMed Central Ltd.

Hassan S.H.,Universiti Sains Malaysia
Journal of Islamic Marketing | Year: 2011

Purpose: The purpose of this paper is to reveal and understand the consumption of functional food model for Malay Muslim consumers in Malaysia. The paper presents a new framework to understand how the majority of Malay Muslim consumers living in multicultural societies make their functional food choices in the modern world. Design/methodology/approach: The data were collected through a self-administrated questionnaire survey that was distributed using convenience sampling. The items for the questionnaire were identified from a preliminary model derived from the qualitative analysis input using ethnoconsumerist and grounded theory methodologies. Structural equation modelling was used to develop the consumption of functional food model for Malay Muslims in Malaysia. Findings: These findings have practical implications for public policymakers (e.g. government and consumer educators), industrial food practitioners, market researchers and manufacturers who produce, sell or market functional foods in Malaysia. Research limitations/implications: This research is specific to functional food consumption and Malay Muslim consumers. Thus, the results in this study may not be applicable to cultures in general. Originality/value: In terms of originality, the empirical findings of this study represent a contribution to the literature in the area of food marketing in developing multicultural countries, because the model is developed in a cross-cultural context. The model is specific to the Malay Muslim population. © Emerald Group Publishing Limited.

Razak N.A.,Universiti Sains Malaysia | Dimitriadis G.,University of Liege
Journal of Fluids and Structures | Year: 2014

This paper presents the results of experiments carried out on mechanical wings undergoing active root flapping and pitching in the wind tunnel. The objective of the work is to investigate the effect of the pitch angle oscillations and wing profile on the aerodynamic forces generated by the wings. The experiments were repeated for a different reduced frequency, airspeed, flapping and pitching kinematics, geometric angle of attack and wing sections (one symmetric and two cambered airfoils). A specially designed mechanical flapper was used, modelled on large migrating birds. It is shown that, under pitch leading conditions, good thrust generation can be obtained at a wide range of Strouhal numbers if the pitch angle oscillation is adjusted accordingly. Consequently, high thrust was measured at both the lowest and highest tested Strouhal numbers. Furthermore, the work demonstrates that the aerodynamic forces can be sensitive to the Reynolds number, depending on the camber of the wings. Under pitch lagging conditions, where the effective angle of attack amplitude is highest, the symmetric wing was affected by the Reynolds number, generating less thrust at the lowest tested Reynolds value. In contrast, under pure flapping conditions, where the effective angle of attack amplitude was lower but still significant, it was the cambered wings that demonstrated Reynolds sensitivity. © 2014 Elsevier Ltd.

Yusoff M.S.B.,Universiti Sains Malaysia
Sultan Qaboos University Medical Journal | Year: 2013

Objectives: The demanding and intense environment of medical training can create excessive pressures on medical students that eventually lead to unfavorable consequences, either at a personal or professional level. These consequences can include poor academic performance and impaired cognitive ability. This study was designed to explore associations between pass-fail outcome and psychological health parameters (i.e. stress, anxiety, and depression symptoms). Methods: A cross-sectional study was conducted on a cohort of first-year medical students in a Malaysian medical school. The depression anxiety stress scale 21-item assessment (DASS-21) was administered to them right after the final paper of the first-year final examination. Their final examination outcomes (i.e. pass or fail) were traced by using their student identity code (ID) through the Universiti Sains Malaysia academic office. Results: A total of 194 (98.0%) of medical students responded to the DASS-21. An independent t-test showed that students who passed had significantly lower stress, anxiety, and depression symptoms than those who failed the first-year final examination (P <0.05). Those who experienced moderate to high stress were at 2.43 times higher risk for failing the examination than those who experienced normal to mild stress. Conclusion: Medical students who failed in the final examination had higher psychological distress than those who passed the examination. Those who experienced high stress levels were more likely to fail than those who did not. Reducing the psychological distress of medical students prior to examination may help them to perform better in the examination.

Faisal A.,Muhammadiyah University of Sumatera Utara | Majid T.A.,Universiti Sains Malaysia | Hatzigeorgiou G.D.,Democritus University of Thrace
Soil Dynamics and Earthquake Engineering | Year: 2013

The present study focuses on the influence of repeated earthquakes on the maximum story ductility demands of three-dimensional inelastic concrete frames. A comprehensive assessment is conducted using generic frames with 3-, 6-, 12-, and 18-story structures. Each is assumed to have behaviour factors of 1.5, 2, 4, and 6 referring to Eurocode 8. Stiffness and strength degrading hysteresis rule to represent reinforced concrete structure is considered in the plastic hinge of members. Twenty ground motions are selected, and single, double, and triple events of synthetic repeated earthquakes are considered. Some interesting findings are provided showing that repeated earthquakes significantly increase the story ductility demand of inelastic concrete frames. On average, relative increment of maximum story ductility demand is experienced 1.4 and 1.3 times when double and triple events of repeated earthquakes are induced, respectively. Empirical relationships are also provided to predict these increments where their efficiency is presented examining characteristic 3- and 8-story reinforced concrete buildings. © 2012 Elsevier Ltd.

Mohamed A.R.,Universiti Sains Malaysia | Mohammadi M.,Noushirvani University of Technology | Darzi G.N.,Noushirvani University of Technology
Renewable and Sustainable Energy Reviews | Year: 2010

A literature review on preparation of carbon molecular sieve (CMS) from lignocellulosic biomass is presented. The effect of various operation parameters such as pyrolytic temperature, flow rate of the carbonizing agent and time of pyrolysis on the carbonization of the lignocellulosic biomass as a carbon precursor was reviewed. Various physical and chemical processes for the activation of the biomass-based char and their effects on textural properties of the activated char were discussed. Conversion of activated chars to CMS as the final stage of the preparation process through different techniques of chemical vapor deposition (CVD) and controlled pyrolysis was assessed. Survey of literature revealed that production of CMS with BET surface area of 1247 m2/g and micropore volume of 0.51 cm3/g, under appropriate conditions has been reported. Also, maximum selectivity of 7.6 and 400 for separation of O2/N2 and CO2/CH4 was devoted to palm shell and coconut shell-based CMS, respectively. © 2010 Elsevier Ltd. All rights reserved.

Zainul Abidin Nazirah N.,Universiti Sains Malaysia
Habitat International | Year: 2010

In Malaysia, the issues of environmental dissatisfaction with construction projects have regularly appeared in newspaper headlines. The government has urged the professional bodies and developers to take proactive actions to promote the sustainability concept within their domain and be responsive to the need for better environmental and social protection. Given rising concerns over the deterioration in the environment, developers should get their acts together and revisit the development approaches they have been so used to. The pace of actions towards sustainable application depends on the awareness, knowledge as well as an understanding of the consequences of individual actions. Two field studies, surveys and interviews, have been conducted to investigate the level of awareness, knowledge and implementation of sustainable practices based on the perceptions of the project developers in Malaysia. Presently, only large developers are beginning to take heed towards sustainable implementation in their projects. Due to limited understanding and the concern about cost, many developers are still reluctant and uncertain concerning pursuit of sustainability in their projects. To improve the momentum of sustainable practice in the industry, actions should be directed towards improving this knowledge at all levels of developers. © 2009 Elsevier Ltd.

Sankar D.S.,Universiti Sains Malaysia
International Journal of Nonlinear Sciences and Numerical Simulation | Year: 2010

In this theoretical study, the pulsatile flow of a two-fluid model for blood in narrow arteries with mild stenosis under periodic body acceleration is analyzed. The suspension of all the erythrocytes in the core region is assumed as Herschel-Bulkley fluid and the plasma in the peripheral layer region is treated as Newtonian fluid. Perturbation method is used to solve the resulting system of nonlinear partial differential equations. The expressions for the physiologically important flow quantities such as velocity, wall shear stress, plug core radius, flow rate and longitudinal impedance to flow are obtained. The effects of the parameters( body acceleration, depth of the stenosis, yield stress, width of the peripheral layer, pulsatility and lead angle) on these flow quantities are analyzed through appropriate graphs. It is observed that the plug core radius, wall shear stress and longitudinal impedance to flow increase with the increase of the yield stress, lead angle and stenosis depth. It is found that the velocity and flow rate increase with the increase of the pulsatile Reynolds number, body acceleration, pressure gradient and width of the peripheral layer thickness. It is also noted that the wall shear stress and longitudinal impedance to flow are considerably lower for the two-fluid Herschel-Bulkley model than that of the single-fluid Herschel-Bulkley model. Also, it is noticed that the estimates of the mean flow rate and mean velocity increase significantly with the increase of body acceleration and peripheral layer. ©Freund Publishing House Ltd.

Esa N.,Universiti Sains Malaysia
International Research in Geographical and Environmental Education | Year: 2010

Within this decade of Education for Sustainable Development (ESD), educational institutions need to increase their efforts to educate their students for a sustainable future. Teachers are most influential in educating children and teenagers to be leaders of tomorrow in protecting the environment. Thus, aspiring teachers should demonstrate pro-environmental behaviour and attitudes if they are to integrate ESD effectively in their teaching upon graduation. They should also have good knowledge about the environment to ensure effective delivery. However, previous studies show that many students and teachers lack sufficient environmental knowledge but demonstrate positive attitudes towards the environment. This lack of knowledge is believed to contribute to the lack of pro-environmental behaviours among them. This study is a survey of the environmental knowledge, attitude and practices of pre-service secondary teachers enrolled in an undergraduate Biology Teaching Methods course. The results suggest the readiness of these teachers to realise the goal of integrating ESD in the teaching of biology in schools. Results also indicate the need for more concerted effort in teacher education to prepare them for their role in educating for and about the environment. © 2010 Taylor & Francis.

Aljumah K.,Al Amal Psychiatric Hospital | Hassali M.A.,Universiti Sains Malaysia
BMC Psychiatry | Year: 2015

Background: Adherence to antidepressant treatment is essential for the effective management of patients with major depressive disorder. Adherence to medication is a dynamic decision-making process, and pharmacists play an important role in improving adherence to antidepressant treatment in different settings within the healthcare system. The aim of this study was to assess whether pharmacist interventions based on shared decision making improved adherence and patient-related outcomes. Methods: This was a randomised controlled study with a 6-month follow-up. Participants were randomly allocated to two groups: 1) intervention group (IG) (usual pharmacy services plus pharmacist interventions based on shared decision making); or 2) control group (CG) (usual pharmacy services). Recruited patients fulfilled the following inclusion criteria: aged 18 to 60 years diagnosed with a major depressive disorder, and no history of psychosis or bipolar disorders. A research assistant blinded to the group allocations collected all data. Results: Two hundred and thirty-nine patients met the inclusion criteria and were randomised to the IG (n = 119) or CG (n = 120). Nineteen patients dropped out of the study during the follow-up phase. After 6 months, patients in the IG had significantly more favorable medication adherence, treatment satisfaction, general overuse beliefs, and specific concern beliefs. However, the groups did not differ in severitye of depression or health-related quality of life after 6 months. Conclusions: Our findings emphasise the important role of pharmacists in providing direct patient care in regular pharmacy practice to improve adherence to medications and other patient-reported outcomes. © 2015 Aljumah and Hassali.

Boukraa L.,Universiti Sains Malaysia
Forschende Komplementärmedizin (2006) | Year: 2010

Management of the burn wound still remains a matter of debate, and an ideal dressing for burn wounds has not yet been discovered. Naturally occurring substances such as honey have been found to be useful as a wound cover for burns. Unlike most conventional local chemotherapeutics, honey does not lead to the development of antibiotic-resistant bacteria, and it may be used continuously. Among the challenging problems of using honey for medical purposes are dosage, safety, and formulation. Many approaches have been suggested to overcome such problems. With the increased availability of licensed medical products containing honey, clinical use is expected to increase and further evidence will become available. Honey seems to have the potential to clear infection as well as to be an effective prophylactic agent that may contribute to reducing the risks of cross-infection. A better understanding of the therapeutic and chemical properties of honey is needed to optimise the use of this product in the clinical management of burns. Its use in professional care centres should be limited to those with certified healing activities. The potentials and limitations of using honey as burn dressing are discussed in this review. Copyright 2010 S. Karger AG, Basel.

Lok Y.Y.,Universiti Sains Malaysia | Merkin J.H.,University of Leeds | Pop I.,Babes - Bolyai University
Transport in Porous Media | Year: 2013

The mixed convection boundary-layer flow on one face of a semi-infinite vertical surface embedded in a fluid-saturated porous medium is considered when the other face is taken to be in contact with a hot or cooled fluid maintaining that surface at a constant temperature Tf. The governing system of partial differential equations is transformed into a system of ordinary differential equations through an appropriate similarity transformation. These equations are solved numerically in terms of a dimensionless mixed convection parameter ε and a surface heat transfer parameter γ. The results indicate that dual solutions exist for opposing flow, ε < 0, with the dependence of the critical values εc on γ being determined, whereas for the assisting flow ε > 0, the solution is unique. Limiting asymptotic forms for both γ small and large and ε large are also discussed. © 2013 Springer Science+Business Media Dordrecht.

Rashidi N.A.,Petronas University of Technology | Yusup S.,Petronas University of Technology | Hameed B.H.,Universiti Sains Malaysia
Energy | Year: 2013

CO2(Carbon dioxide) emissions are one of the greenhouse gases that cause global warming. The power generation industry is one of the main emitters of CO2, and the emissions are expected to increase in the coming years as there seems to be no abatement in the consumption of fossil fuels for the production of electricity. Thus, there is a need for CO2 adsorption technologies to mitigate the emissions. However, there are several disadvantages associated with the current adsorption technologies. One of the issues is corrosion and the need for specialized equipment. Therefore, alternative and more sustainable materials are sought after to improve the viability of the adsorption technology. In this study, several types of agricultural wastes were used as activated carbon precursors for CO2 adsorption process in a TGA (thermogravimetric analyser). The adsorption was also modelled through a pseudo-first order and second order model, Elovich's kinetic model, and an intra-particle diffusion model. From the correlation coefficient, it was found that pseudo-second order model was well-fitted with the kinetic data. In addition, activation energy below than 42kJ/mol confirmed that the physisorption process occurred. © 2013 Elsevier Ltd.

Al-Mulali U.,University of Technology Malaysia | Fereidouni H.G.,University of Technology Malaysia | Lee J.Y.M.,University of Technology Malaysia | Sab C.N.B.C.,Universiti Sains Malaysia
Renewable and Sustainable Energy Reviews | Year: 2013

This study explored the relationship between urbanization, energy consumption, and CO2 emission in the MENA countries. The panel model was utilized taking the period 1980-2009 into consideration. Pedroni cointegration test results showed that urbanization, energy consumption and CO2 emission were cointegrated. The dynamic OLS results also showed that there was a long run bi-directional positive relationship between urbanization, energy consumption, and CO2 emission. However, the significance of the long run relationship between urbanization, energy consumption, and CO2 emission varied across the countries based on their level of income and development. Moreover, long and short run bi-directional causal relationships were found between the variables based on the Granger causality test results. From the results of this study it is important for the urban planners and policy makers in the MENA countries to slow the rapid increase in urbanization. The level of energy consumption and CO 2 emission in the MENA countries increased more than double. Thus slowing down the urbanization level can help reduce the level of pollution and energy consumption. In addition, the increased energy efficiency, implementation of energy savings projects, energy conservation, and energy infrastructure outsourcing reduce the level of pollution produced by urban areas. © 2013 Elsevier Ltd.

Gui M.M.,University of Selangor | Yap Y.X.,University of Selangor | Chai S.-P.,University of Selangor | Mohamed A.R.,Universiti Sains Malaysia
International Journal of Greenhouse Gas Control | Year: 2013

Multi-walled carbon nanotubes (MWCNTs) were modified with (3-aminopropyl)triethoxysilane (APTES) solution in a two-step process. In the first step, the MWCNTs were pre-treated with sulfuric acid and nitric acid (5 molar each mixed at ratio of 3:1, v/v) with the aims to remove metal catalysts impurities and to introduce carboxyl groups on the MWCNT surface. In the second step, the acid pre-treated MWCNTs were functionalized with APTES at 105°C under various reflux durations. The characteristics of the functionalized MWCNTs were studied by Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and Raman spectroscopy. TG analysis shows an increase in APTES loading with increasing reflux duration, giving the maximum loading of 13.75wt%. This result suggests that as reflux duration increased, more amine groups were attached covalently on the MWCNT surface, forming effective mechanism sites for CO2 adsorption. The highest CO2 uptake of 75.4mg CO2 adsorbed/g adsorbent was achieved by the amine-functionalized MWCNTs, indicating its superior performance than some other commonly used adsorbents such as SBA-15. © 2013 Elsevier Ltd.

Azamathulla H.M.,Universiti Sains Malaysia | Guven A.,University of Gaziantep | Demir Y.K.,University of Gaziantep
Ocean Engineering | Year: 2011

Genetic programming (GP) has nowadays attracted the attention of researchers in the prediction of hydraulic data. This study presents Linear Genetic Programming (LGP), which is an extension to GP, as an alternative tool in the prediction of scour depth below a pipeline. The data sets of laboratory measurements were collected from published literature and were used to develop LGP models. The proposed LGP models were compared with adaptive neuro-fuzzy inference system (ANFIS) model results. The predictions of LGP were observed to be in good agreement with measured data, and quite better than ANFIS and regression-based equation of scour depth at submerged pipeline. © 2011 Elsevier Ltd.

Mirjalili F.,University Putra Malaysia | Hasmaliza M.,Universiti Sains Malaysia | Abdullah L.C.,University Putra Malaysia
Ceramics International | Year: 2010

Nano α-alumina particles were synthesized by a sol-gel method using aqueous solutions of aluminum isopropoxide and 0.5 M aluminum nitrate. 1/3-benzened disoulfonic acid disodium salt (SDBS) and sodium bis-2-ethylhexyl sulfosuccinate (Na(AOT)) were used as surfactant stabilizing agents. Solution was stirred for different periods (24, 36, 48 and 60 h) at 60 °C. The samples were then analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Introduction of surfactant stabilizing agents and different stirring times will affect the size and shape of particle formed and also the degree of aggregation. SDBS, however, produced better dispersion, finer particles and spherical shape nanoparticles, compared to Na(AOT). The finest particle size (20-30 nm) was obtained at 48 h stirring time with SDBS surfactant. © 2010 Elsevier Ltd and Techna Group S.r.l.

Shahbaz M.,COMSATS Institute of Information Technology | Lean H.H.,Universiti Sains Malaysia
Energy | Year: 2012

This study revisits the relationship between electricity consumption and economic growth in Pakistan by controlling and investigating the effects of two major production factors - capital and labor. The empirical evidence confirms the cointegration among the variables and indicates that electricity consumption has a positive effect on economic growth. Moreover, bi-directional Granger causality between electricity consumption and economic growth has been found. The finding suggests that adoption of electricity conservation policies to conserve energy resources may unwittingly decline economic growth and the lower growth rate will in turn further decrease the demand for electricity. Therefore, government contemplating such conservationist policies should instead explore and develop alternate sources of energy as a strategy rather than just increasing electricity production per se in order to meet the rising demand for electricity in their quest towards sustaining development in the country. © 2012 Elsevier Ltd.

Ahmad S.,Universiti Sains Malaysia | Pop I.,Babes - Bolyai University
Transport in Porous Media | Year: 2014

The effect of melting phenomenon on the steady mixed convection boundary layer flow about a vertical surface embedded in a fluid-saturated porous medium is numerically studied. The boundary layer partial differential equations are transformed into a set of nonlinear ordinary differential equations by using similarity transformation and then are solved using the shooting method for different values of the mixed convection and melting parameters. Results show that dual solutions exist for a certain range of these parameters. The results also indicate that the melting phenomenon reduces the heat transfer rate and expedites the boundary layer separation. © 2014 Springer Science+Business Media Dordrecht.

Ng L.Y.,National University of Malaysia | Mohammad A.W.,National University of Malaysia | Leo C.P.,Universiti Sains Malaysia | Hilal N.,University of Swansea
Desalination | Year: 2013

Synthetic membranes have become the focus of separation processes in different industries. Synthetic membranes may be composed of inorganic materials (such as ceramics) and organic materials (such as polymers). Current research on membranes focus more on polymeric membranes due to better control of the pore forming mechanism, higher flexibility, smaller spaces required for installation and lower costs compared to inorganic membranes. Though polymeric membranes have these properties which make them better materials in membrane fabrication, they also have some disadvantages which need to be overcome. Common problems faced by polymeric membranes, such as high hydrophobicity, exposure to biofouling, low fluxes and low mechanical strength have become the focus of researchers in order to improve these disadvantages. The incorporation of nanoparticles into polymeric membranes has been the trend in the field of membrane research recently. Incorporation of nano-sized materials could produce synergistic effects when incorporated with different types of materials. This paper discusses a few types of nanoparticles incorporated into various types of polymeric membranes. Nanoparticles that will be discussed include silver, iron, zirconium, silica, aluminium, titanium, and magnesium based nanoparticles. Nanoparticles affect the permeability, selectivity, hydrophilicity, conductivity, mechanical strength, thermal stability, and the antiviral and antibacterial properties of the polymeric membranes. Though nanoparticles usually improve the performances of the membranes, they also might change or even deteriorate the performances of the membranes. Thus, careful study needs to be done in order to choose the most appropriate types and composition of nanoparticles to be incorporated into polymeric membranes. © 2010 Elsevier B.V.

Ong W.-J.,University of Selangor | Tan L.-L.,University of Selangor | Chai S.-P.,University of Selangor | Yong S.-T.,University of Selangor | Mohamed A.R.,Universiti Sains Malaysia
Nano Energy | Year: 2015

In this work, we reported a 2D/2D hybrid heterojunction photocatalyst with effective interfacial contact by incorporating reduced graphene oxide (rGO) and protonated g-C3N4 (pCN) synthesized by a novel combined ultrasonic dispersion and electrostatic self-assembly strategy followed by a NaBH4-reduction process. The resulting 2D rGO-hybridized pCN (rGO/pCN) nanostructures formed an intimate contact across the heterojunction interface as supported by the electron microscopy analysis. The rGO/pure g-C3N4 (rGO/CN) developed without the modification of surface charge on g-C3N4 has also been prepared for comparison. Compared with pure g-C3N4 and rGO/CN, the rGO/pCN photocatalysts demonstrated a remarkable enhancement on the CO2 reduction in the presence of H2O vapor to CH4 under a low-power energy-saving daylight bulb at ambient temperature and atmospheric pressure. The optimized 15wt% rGO/pCN (15rGO/pCN) exhibited the highest CH4 evolution of 13.93μmol gcatalyst-1 with a photochemical quantum yield of 0.560%, which was 5.4- and 1.7-folds enhancement over pCN and 15rGO/CN samples, respectively. This was ascribed to the addition of rGO with pCN in a controlled ratio as well as sufficient interfacial contact between rGO and pCN across the rGO/pCN heterojunction for efficient charge transfer to suppress the recombination of electron-hole pairs as evidenced by the electron microscopy, zeta potential and photoluminescence studies. In addition, the 15rGO/pCN possessed a moderately high stability after three successive cycles with no obvious change in the production of CH4 from CO2 reduction. Lastly, a visible-light photocatalytic mechanism associated with rGO/pCN hybrid nanoarchitectures was presented. © 2015 Elsevier Ltd.

Supri A.G.,University Malaysia Perlis | Ismail H.,Universiti Sains Malaysia
Polymer - Plastics Technology and Engineering | Year: 2012

The effect of vinyl alcohol-phthalic anhydride as a coupling agent on the tensile properties, morphology, and thermal degradation of low density polyethylene/tyre dust (LDPE/TD) composites was studied. LDPE/TD composites with different tyre dust loading and the addition of vinyl alcohol-phthalic anhydride were prepared with Z-blade mixer at 180°C and rotor speed of 50 rpm. The result indicated that LDPE/TD M composites with vinyl alcohol-phthalic anhydride show higher values of tensile strength, Young's modulus and mass swell, but lower elongation at break than LDPE/TD composites without vinyl alcohol-phthalic anhydride. The SEM micrographs showed that the tyre dust was more widely dispersed in the LDPE matrix with the addition of vinyl alcohol-phthalic anhydride as a coupling agent. It was also found that the addition of vinyl alcohol-phthalic anhydride offers better thermal stability in the LDPE/TD M composites than LDPE/TD composites. © 2012 Copyright Taylor and Francis Group, LLC.

Khan Z.A.,Jamia Millia Islamia University | Kamaruddin S.,Universiti Sains Malaysia | Siddiquee A.N.,Jamia Millia Islamia University
Materials and Design | Year: 2010

Usability of recycled High Density Polyethylene (HDPE) as substitute for virgin HDPE is investigated. Optimization design of the injection moulding parameters for recycled HDPE products is presented. Tensile, compressive and flexural strengths are selected to evaluate the process performance and the corresponding moulding parameters are melt temperature, holding pressure, injection time, and holding time. Optimal combination of injection moulding parameters is determined using Grey relational analysis. The principal component analysis is applied to evaluate the weighting values corresponding to various performance characteristics. Tensile, compressive and flexural strengths of the recycled HDPE are found close to that of virgin HDPE. Thus, recycled HDPE is a good substitute for virgin HDPE. Optimal combination of the process parameters for the multi-performance characteristics of the recycled HDPE is the set with melt temperature at 240 °C, holding pressure at 255 N/m2, injection time at 0.6 s and holding time at 30 s. © 2009 Elsevier Ltd. All rights reserved.

Koriem K.M.M.,National Research Center of Egypt | Koriem K.M.M.,Universiti Sains Malaysia | Soliman R.E.,Cairo University
Journal of Toxicology | Year: 2014

Methamphetamine intoxication can cause acute hepatic failure. Chlorogenic and caftaric acids are the major dietary polyphenols present in various foods. The aim of this study was to evaluate the protective role of chlorogenic and caftaric acids in liver toxicity and oxidative stress induced by methamphetamine in rats. Thirty-two male albino rats were divided into 4 equal groups. Group 1, which was control group, was injected (i.p) with saline (1 mL/kg) twice a day over seven-day period. Groups 2, 3, and 4 were injected (i.p) with methamphetamine (10 mg/kg) twice a day over seven-day period, where groups 3 and 4 were injected (i.p) with 60 mg/kg chlorogenic acid and 40mg/kg caftaric acid, respectively, one day before methamphetamine injections. Methamphetamine increased serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, bilirubin, cholesterol, low-density lipoprotein, and triglycerides. Also, malondialdehyde in serum, liver, and brain and plasma and liver nitric oxide levels were increased while methamphetamine induced a significant decrease in serum total protein, albumin, globulin, albumin/globulin ratio, brain serotonin, norepinephrine and dopamine, blood and liver superoxide dismutase, and glutathione peroxidase levels. Chlorogenic and caftaric acids prior to methamphetamine injections restored all the above parameters to normal values. In conclusion, chlorogenic and caftaric acids before methamphetamine injections prevented liver toxicity and oxidative stress where chlorogenic acid was more effective. Copyright © 2014 K. M. M. Koriem and R. E. Soliman.

Lean H.H.,Universiti Sains Malaysia | Smyth R.,Monash University
Applied Energy | Year: 2013

This study examines the integration properties of total renewable energy production, as well as production of biofuels and biomass in the United States. To do so we use Lagrange Multiplier (LM) univariate unit root tests with up to two structural breaks. We conclude that each production series has a unit root. The result suggests that random shocks, encompassing changes to regulation, to renewable energy production may lead to permanent departures from predetermined target levels. Furthermore, this result implies that permanent positive shocks (such as renewable portfolio standards) that increases the production of renewable energy resources will realize more in terms of positively altering the energy mix between renewable energy and energy from fossil fuels than temporary policy stances (such as investment tax credits over a predetermined time horizon). © 2012 Elsevier Ltd.

Syed-Mohamad S.M.,Universiti Sains Malaysia
The HIM journal | Year: 2010

This paper describes the method used to develop the One Stop Crisis Centre (OSCC) Portal, an open source web-based electronic patient record system (EPR) for the One Stop Crisis Center, Hospital Universiti Sains Malaysia (HUSM) in Kelantan, Malaysia. Features and functionalities of the system are presented to demonstrate the workflow. Use of the OSCC Portal improved data integration and data communication and contributed to improvements in care management. With implementation of the OSCC portal, improved coordination between disciplines and standardisation of data in HUSM were noticed. It is expected that this will in turn result in improved data confidentiality and data integrity. The collected data will also be useful for quality assessment and research. Other low-resource centers with limited computer hardware and access to open-source software could benefit from this endeavour.

Azamathulla H.M.,Universiti Sains Malaysia
Journal of Hydrology | Year: 2012

Local scour is crucial in the degradation of river bed and the stability of grade control structures, stilling basins, aprons, ski-jump bucket spillways, bed sills, weirs, check dams, etc. This short communication presents gene-expression programming (GEP), which is an extension to genetic programming (GP), as an alternative approach to predict scour depth downstream of sills. Published data were compiled from the literature for the scour depth downstream of sills. The proposed GEP approach gives satisfactory results (R 2=0.967 and RMSE=0.088) compared to the existing predictors (Chinnarasri and Kositgittiwong, 2008) with R 2=0.87 and RMSE=2.452 for relative scour depth. © 2012 Elsevier B.V.

Moniruzzaman M.,Universiti Sains Malaysia
African journal of traditional, complementary, and alternative medicines : AJTCAM / African Networks on Ethnomedicines | Year: 2012

Free radicals and reactive oxygen species (ROS) have been implicated in contributing to the processes of aging and disease. In an effort to combat free radical activity, scientists are studying the effects of increasing individuals' antioxidant levels through diet and dietary supplements. Honey appears to act as an antioxidant in more ways than one. In the body, honey can mop up free radicals and contribute to better health. Various antioxidant activity methods have been used to measure and compare the antioxidant activity of honey. In recent years, DPPH (Diphenyl-1-picrylhydrazyl), FRAP (Ferric Reducing Antioxidant Power), ORAC (The Oxygen Radical Absorbance Capacity), ABTS [2, 2-azinobis (3ehtylbenzothiazoline-6-sulfonic acid) diamonium salt], TEAC [6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid (Trolox)-equivalent antioxidant capacity] assays have been used to evaluate antioxidant activity of honey. The antioxidant activity of honey is also measured by ascorbic acid content and different enzyme assays like Catalase (CAT), Glutathione Peroxidase (GPO), Superoxide Dismutase (SOD). Among the different methods available, methods that have been validated, standardized and widely reported are recommended.

Menon K.C.,Universiti Sains Malaysia
Asian Pacific Journal of Cancer Prevention | Year: 2014

Involvement of a multidisciplinary team in cancer care may have added benefits over the existing system of patient management. A paradigm shift in the current patient management would allow more focus on nutritional support, in addition to clinical care. Malnutrition, a common problem in cancer patients, needs special attention from the early days of cancer care to improve quality of life and treatment outcomes. Patient management teams with trained oncology dietitians may provide quality personalized nutritional care to cancer patients.

Yusoff M.S.B.,Universiti Sains Malaysia
Journal of Taibah University Medical Sciences | Year: 2014

Introduction Three systemic reviews reported that, although many studies echoed the importance of stress management programs in medical curricula, yet very few high quality studies provided convincing evidence of their effectiveness. So far, none of meta-analysis study was done to appraise their effectiveness on medical students' psychological health. Objective The author conducted a meta-analysis to quantitatively appraise and summarize all studies of stress management interventions on medical students' psychological health that include general psychological distress, stress, anxiety and depression symptoms. Method The author planned, conducted and reported this study according to the PRISMA standard of quality for reporting meta-analyses. Result The author yielded 23,921 relevant articles based on search terms and eventually, after critical appraisal, only 13 articles were included in the meta-analysis. Stress management interventions were associated with moderate, statistically significant improvement of medical students' psychological health [-0.335 (95% CI, -0.423, -0.246), P < 0.001] with low inconsistency among the studies (I2 = 30.46%). Subgroup analyses demonstrated there were consistent interactions with the duration of intervention (Q-value (df) = 15.56 (3), p = 0.001) and research design (Q-value (df) = 4.93 (1), p = 0.026). Sensitivity analyses did not change the study conclusions. Conclusion Stress management interventions were associated with moderate effects on medical students' psychological health compared with no intervention. Brief to medium-duration intervention demonstrated significant larger effects than long-duration intervention. Likewise, RCT studies showed larger effects than non-RCT studies. Future research with RCT design should directly compare different types of stress management interventions based on a sound theoretical basis. © 2014 Taibah University. Production and hosting by Elsevier Ltd. All rights reserved.

Abdul Ghani A.S.,University of Malaysia, Terengganu | Mat Isa N.A.,Universiti Sains Malaysia
Applied Soft Computing Journal | Year: 2015

The physical properties of water cause light-induced degradation of underwater images. Light rapidly loses intensity as it travels in water, depending on the color spectrum wavelength. Visible light is absorbed at the longest wavelength first. Red and blue are the most and least absorbed, respectively. Underwater images with low contrast are captured due to the degradation effects of light spectrum. Therefore, the valuable information from these images cannot be fully extracted for further processing. The current study proposes a new method to improve the contrast and reduce the noise of underwater images. The proposed method integrates the modification of image histogram into two main color models, Red-Green-Blue (RGB) and Hue-Saturation-Value (HSV). In the RGB color model, the histogram of the dominant color channel (i.e., blue channel) is stretched toward the lower level, with a maximum limit of 95%, whereas the inferior color channel (i.e., red channel) is stretched toward the upper level, with a minimum limit of 5%. The color channel between the dominant and inferior color channels (i.e., green channel) is stretched to both directions within the whole dynamic range. All stretching processes in the RGB color model are shaped to follow the Rayleigh distribution. The image is converted into the HSV color model, wherein the S and V components are modified within the limit of 1% from the minimum and maximum values. Qualitative analysis reveals that the proposed method significantly enhances the image contrast, reduces the blue-green effect, and minimizes under- and over-enhanced areas in the output image. For quantitative analysis, the test with 300 underwater images shows that the proposed method produces average mean square error (MSE) and peak signal to noise ratio (PSNR) of 76.76 and 31.13, respectively, which outperform six state-of-the-art methods. © 2014 Elsevier B.V. All rights reserved.

Shahbaz M.,COMSATS Institute of Information Technology | Lean H.H.,Universiti Sains Malaysia
Energy Policy | Year: 2012

This paper assesses the relationship among energy consumption, financial development, economic growth, industrialization and urbanization in Tunisia from 1971 to 2008. The autoregressive distributed lag bounds testing approach to cointegration and Granger causality tests is employed for the analysis. The result confirms the existence of long-run relationship among energy consumption, economic growth, financial development, industrialization and urbanization in Tunisia. Long-run bidirectional causalities are found between financial development and energy consumption, financial development and industrialization, and industrialization and energy consumption. Hence, sound and developed financial system that can attract investors, boost the stock market and improve the efficiency of economic activities should be encouraged in the country. Nevertheless, promoting industrialization and urbanization can never be left out from the process of development. We add light to policy makers with the role of financial development, industrialization and urbanization in the process of economic development. © 2011 Elsevier Ltd.

Reducing building material costs by identifying sustainable and green construction materials is desirable for economic reasons and environmental responsibility. This study examines ways to enhance strength of foamed concrete by adding wood ash (WA) and silica fume (SF). The effect of different percentage combinations is investigated, to understand the effect on the flexural and splitting tensile strengths. The supplementary binders replace a percentage by weight of the cement and are blended with foamed concrete. The WA-SF mixes at 5%-15%, 10%-10%, and 15%-5%, were compared to standard foamed concrete. The microstructures show evidence of novel densification and there was an improvement in the flexural and tensile strengths. The 5% WA-15% SF mix has the most significant effect on the foamed concrete compared to the control. The binder matrix also prolonged the setting time of the cement paste. © 2015 Penerbit UTM Press. All rights reserved.

Erejuwa O.O.,Universiti Sains Malaysia
International journal of biological sciences | Year: 2011

Diabetes mellitus is associated with deterioration of glycemic control and progressive metabolic derangements. This study investigated the effect of honey as an adjunct to glibenclamide or metformin on glycemic control in streptozotocin-induced diabetic rats. Diabetes was induced in rats by streptozotocin. The diabetic rats were randomized into six groups and administered distilled water, honey, glibenclamide, glibenclamide and honey, metformin or metformin and honey. The animals were treated orally once daily for four weeks. The diabetic control rats showed hypoinsulinemia (0.27 ± 0.01 ng/ml), hyperglycemia (22.4 ± 1.0 mmol/L) and increased fructosamine (360.0 ± 15.6 μmol/L). Honey significantly increased insulin (0.41 ± 0.06 ng/ml), decreased hyperglycemia (12.3 ± 3.1 mmol/L) and fructosamine (304.5 ± 10.1 μmol/L). Although glibenclamide or metformin alone significantly (p < 0.05) reduced hyperglycemia, glibenclamide or metformin combined with honey produced significantly much lower blood glucose (8.8 ± 2.9 or 9.9 ± 3.3 mmol/L, respectively) compared to glibenclamide or metformin alone (13.9 ± 3.4 or 13.2 ± 2.9 mmol/L, respectively). Similarly, glibenclamide or metformin combined with honey produced significantly (p < 0.05) lower fructosamine levels (301.3 ± 19.5 or 285.8 ± 22.6 μmol/L, respectively) whereas glibenclamide or metformin alone did not decrease fructosamine (330.0 ± 29.9 or 314.6 ± 17.9 μmol/L, respectively). Besides, these drugs or their combination with honey increased insulin levels. Glibenclamide or metformin combined with honey also significantly reduced the elevated levels of creatinine, bilirubin, triglycerides, and VLDL cholesterol. These results indicate that combination of glibenclamide or metformin with honey improves glycemic control, and provides additional metabolic benefits, not achieved with either glibenclamide or metformin alone.

Tehrani R.M.A.,Islamic Azad University at Tehran | Ab Ghani S.,Universiti Sains Malaysia
Electrochimica Acta | Year: 2012

This study reports the success of using an electrosynthesized nanocrystalline hexagonal close-packed (hcp) nickel (Ni) modified composite graphite (CG) electrode for the electrocatalytic oxidation of glycerol in alkaline medium (0.1 M KOH). The hcp-nano Ni modified CG had an improved response and remarkable electrocatalytic oxidation of glycerol over the bare CG. The electrocatalysis was the result of the formation of NiOOH during the oxidation process. The process was influenced by the scan rate and concentration of glycerol. A linear relationship between the concentrations of glycerol with the current was obtained over a range of 0.5-12.0 mM glycerol, with a limit of detection (S/N = 3) at 0.033 mM glycerol. The hcp-nano Ni modified CG electrode was applied to directly determine the free glycerol concentration in the biodiesel samples. As a glycerol sensor, the hcp-nano Ni modified CG is quite stable. © 2012 Elsevier Ltd. All rights reserved.

Lee K.T.,Universiti Sains Malaysia | Lim S.,University of Malaya | Pang Y.L.,University of Malaya | Ong H.C.,University of Malaya | Chong W.T.,University of Malaya
Progress in Energy and Combustion Science | Year: 2014

Current world energy usage is trying to gradually shift away from fossil fuels due to the concerns for the climate change and environmental pollutions. Liquid energy from renewable biomass is widely regarded as one of the greener alternatives to partially fulfil the ever-growing energy demand. Contemporary research and technology has been focussing on transforming these bio-resources into efficient liquid and gaseous fuels which are compatible with existing petrochemical energy infrastructure. Due to the wide range of properties and compositions from different types of biomass, there are ample of processing routes available to cater for different demands and requirements. In addition, they can produce multi-component products which can be further upgraded into higher value products. This conceives the idea of bio-refinery where different biomass conversion processes are incorporated and proceed simultaneously at one location. However, the underlying complexity in integrating different processes with varying process conditions will undoubtly incurs prohibitive cost. Consequently, process intensification plays an important role in minimizing both the capital and operating costs associated with process integration in bio-refineries. Recently, process intensification for biodiesel production has been developing rigorously due to increasing demand for cost-cutting measures. Supercritical fluid process allows biodiesel production to be performed without any addition of catalyst. Meanwhile, catalytic in situ or reactive extraction process for biodiesel production successfully combines the extraction and reaction phase together in a single processing unit. In this review, the important characteristics and recent progress on both of the intensification processes for biodiesel production will be critically analyzed. The prospects and recent advances of supercritical reactive extraction (SRE) process which integrates both of the processes will also be discussed. This review will also scrutinize on the methods for these processes to compliment future bio-refinery setup and more efficient utilizing of all of the products generated. © 2014 Elsevier Ltd. All rights reserved.

Ong S.Y.,Universiti Sains Malaysia
Journal of integrative bioinformatics | Year: 2010

Signal transduction through protein-protein interactions and protein modifications are the main mechanisms controlling many biological processes. Here we described the implementation of MedScan information extraction technology and Pathway Studio software (Ariadne Genomics Inc.) to create a Salmonella specific molecular interaction database. Using the database, we have constructed several signal transduction pathways in Salmonella enterica serovar Typhi which causes Typhoid Fever, a major health threat especially in developing countries. S. Typhi has several pathogenicity islands that control rapid switching between different phenotypes including adhesion and colonization, invasion, intracellular survival, proliferation, and biofilm formation in response to environmental changes. Understanding of the detailed mechanism for S. Typhi survival in host cells is necessary for development of efficient detection and treatment of this pathogen. The constructed pathways were validated using publically available gene expression microarray data for Salmonella.

Al-Mulali U.,Multimedia University | Ozturk I.,Cag University | Lean H.H.,Universiti Sains Malaysia
Natural Hazards | Year: 2015

This study investigates the influence of disaggregated renewable electricity production by source on CO2 emission in 23 selected European countries for the period of 1990–2013. Panel data techniques were used in examining the relationships. The Pedroni cointegration results indicated that CO2 emission, GDP growth, urbanization, financial development, and renewable electricity production by source were cointegrated. Moreover, the fully modified ordinary least-square results revealed that GDP growth, urbanization, and financial development increase CO2 emission in the long run, while trade openness reduces it. Furthermore, renewable electricity generated from combustible renewables and waste, hydroelectricity, and nuclear power have a negative long-run effect on CO2 emission, while renewable electricity generated from solar power and wind power is insignificant. The VECM Granger causality also revealed that GDP growth is the only variable that has causal effects on CO2 emission in all the investigated models, while the rest of the variables have causal effects on CO2 emission in only a few models. A number of policy recommendations were provided for the European countries. © 2015, Springer Science+Business Media Dordrecht.

Noriman N.Z.,University Malaysia Perlis | Ismail H.,Universiti Sains Malaysia
Journal of Applied Polymer Science | Year: 2012

The recycling or reuse of waste rubber by means of blending together with polymeric materials in addition of filler such as hybrid carbon black and silica (CB/Sil) to a polymer system can provides an opportunity to explore alternative product specifications. Therefore, in this work the investigation of recycled rubber blends based on styrene butadiene rubber/recycled acrylonitrile butadiene rubber (SBR/NBRr) blends reinforced with 50/0, 40/10, 30/20, 20/30, 40/10, 0/50 phr of carbon black/silica (CB/Sil) hybrid filler treated with and without silane coupling agent (Si69) were determined. Cure characteristics, tensile properties, and morphological behavior of selected SBR/NBRr blends at a fix 85/15 blend ratio were evaluated. Results showed that, cure time t 90, minimum torque (M L), and maximum torque (M H) of CB/Sil hybrid fillers filled SBR/NBRr blends with and without Si69 increased as silica content increased. However, t 90 and M L of SBR/NBRr blends with Si69 were lower than without Si69 except for (M H). The optimum scorch time (t s2) of SBR/NBRr blends with and without Si69 was obtained at 30/20 phr of CB/Sil hybrid filler. However, t s2 of SBR/NBRr blends with Si69 were longer than SBR/NBRr blends without Si69. The incorporation of Si69 has improved the tensile properties [(tensile strength, elongation at break (E b), stress at 100% elongation (M100), and stress at 300% elongation (M300)] of CB/Sil hybrid fillers filled SBR/NBRr blends. These properties were influenced by the degree of crosslinked density as the silica content is increased. Scanning electron microscopy (SEM) of the tensile fracture surfaces indicated that, with the addition of Si69 improved the dispersion of hybrid fillers and NBRr in SBR/NBRr matrix. © 2011 Wiley Periodicals, Inc.

Dunn R.A.,Texas A&M University | Tan A.K.G.,Universiti Sains Malaysia
Breast Journal | Year: 2011

As is the case in many developing nations, previous studies of breast cancer screening behavior in Malaysia have used relatively small samples that are not nationally representative, thereby limiting the generalizability of results. Therefore, this study uses nationally representative data from the Malaysia Non-Communicable Disease Surveillance-1 to investigate the role of socio-economic status on breast cancer screening behavior in Malaysia, particularly differences in screening behaviour between ethnic groups. The decisions of 816 women above age 40 in Malaysia to screen for breast cancer using mammography, clinical breast exams (CBE), and breast self-exams (BSE) are modeled using logistic regression. Results indicate that after adjusting for differences in age, education, household income, marital status, and residential location, Malay women are less likely than Chinese and Indian women to utilize mammography, but more likely to perform BSE. Education level and urban residence are positively associated with utilization of each method, but these relationships vary across ethnicity. Higher education levels are strongly related to using each screening method among Chinese women, but have no statistically significant relationship to screening among Malays. © 2011 Wiley Periodicals, Inc.

Zulkepli N.N.,University Malaysia Perlis | Ismail H.,Universiti Sains Malaysia
Polymer - Plastics Technology and Engineering | Year: 2012

The effects of styrene butadiene rubber/virgin acrylonitrile butadiene rubber (SBR/NBRv) blends and styrene butadiene rubber/recycled acrylonitrile butadiene rubber (SBR/NBRr) blends on properties such Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) were carried out. Results indicated that, based on intensity of amine peak from FTIR at 85/15 blend ratio (R15) revealed optimum formation of crosslink between SBR and NBR either using virgin or NBRr. TG thermograms of SBR/NBRv blends of all ratios showed better onset thermal stability than SBR/NBRr blends. The change in the horizontal baseline from high to low energy level occurred in virgin NBR blends because the amount of reactive sites available in virgin NBR is higher compared to NBRr. Meanwhile NBRr blends showed T c because the amount of crosslink occurred in these blends were slightly lower than NBRv blends. Up to 25 phr of NBRr, the tensile strength and elongation at break (E b) retention of SBR/NBRv blends was better than SBR/NBRr blends after 6 months' weathering test except for M100. The scanning electron microscopy on the surface of both blends after 6 months exposure indicated that the severity of the crack was minimal for SBR/NBRr blends compared to SBR/NBRv particularly at 50/50 blend ratio designated the SBR/NBRr blends that contained more NBRr particles could reduce the degradation towards natural weathering. © 2012 Copyright Taylor and Francis Group, LLC.

Mydin M.A.O.,Universiti Sains Malaysia | Wang Y.C.,University of Manchester
Construction and Building Materials | Year: 2012

This paper reports the results of an experimental and analytical study to investigate the mechanical properties of unstressed foamed concrete exposed to high temperatures. Two densities of foamed concrete, 650 and 1000 kg/m 3, were made and tested with additional tests being performed on densities of 800, 1200 and 1400 kg/m3 for additional data. The experimental results consistently demonstrated that the loss in stiffness for foamed concrete at elevated temperatures occurs predominantly after about 90 °C, regardless of density as water expands and evaporates from the porous body. From a comparison of the experimental results of this research with a number of predictive models for normal strength concrete, this research has found that the mechanical properties of foamed concrete can be predicted using the mechanical property models for normal weight concrete given that the mechanical properties of foamed concrete come from Portland Cement CEM1. © 2011 Elsevier Ltd. All rights reserved.

Khan F.N.,Hong Kong Polytechnic University | Khan F.N.,Universiti Sains Malaysia | Zhou Y.,Hong Kong Polytechnic University | Lau A.P.T.,Hong Kong Polytechnic University | Lu C.,Hong Kong Polytechnic University
Optics Express | Year: 2012

We propose a simple and cost-effective technique for modulation format identification (MFI) in next-generation heterogeneous fiber-optic networks using an artificial neural network (ANN) trained with the features extracted from the asynchronous amplitude histograms (AAHs). Results of numerical simulations conducted for six different widely-used modulation formats at various data rates demonstrate that the proposed technique can effectively classify all these modulation formats with an overall estimation accuracy of 99.6% and also in the presence of various link impairments. The proposed technique employs extremely simple hardware and digital signal processing (DSP) to enable MFI and can also be applied for the identification of other modulation formats at different data rates without necessitating hardware changes. © 2012 Optical Society of America.

Kabir S.,Universiti Sains Malaysia
NDT and E International | Year: 2010

Imaging-based inspection methods are increasingly being employed for crack detection in concrete structures, because they provide quantitative information compared to inspections based solely on conventional visual approaches. However, efficient image analysis methods are needed. This study proposes the application of the grey level co-occurrence matrix (GLCM) texture analysis approach and an artificial neural network (ANN) classifier to obtain surface damage information, such as the total amount of superficial cracking, as well as the total length, and range of crack widths. These methods were applied to thermographic, visual colour and greyscale images of concrete blocks from CANMET that were exposed outdoors for ten years, as well as slabs from GRAI that were kept indoors, all specimens exhibiting various levels of alkali-aggregate reaction (AAR) damage. Results of the classifications show that the greyscale imagery performed fairly well, with an overall classification accuracy range of 72.376.5% for the CANMET blocks, and 68.775.3% for the GRAI slabs. Classifications using the colour imagery were slightly better than the greyscale imagery, with accuracies ranging from 71.4% to 75.2% for CANMET blocks and 70.972.0% for the GRAI slabs. The thermographic imagery, however, produced the highest overall classification accuracies, which range from 73.1% to 76.3% for the CANMET blocks and 74.276.9% for the GRAI slabs. The results show that all three types of imagery are relatively effective in characterizing and quantifying crack damage; however, the infrared thermography produced more accurate results compared to the visual colour, and greyscale images. © 2010 Elsevier Ltd. All rights reserved.

Lee B.S.,Universiti Sains Malaysia
Journal of Superconductivity and Novel Magnetism | Year: 2010

The pseudo-gap phenomena in high-temperature cuprate superconductors is an outstanding puzzle with no consensus yet on its physical origin. A previous suggestion on the role of non-linear local lattice instability modes on the microscopic pairing mechanism in high temperature cuprate superconductors is re-examined to investigate whether unusual lattice mechanisms could cause a pseudo-gap. By assuming an electron predominantly interacting with a non-linear Q 2 mode of the oxygen clusters in the CuO 2 planes, we show that the interaction has explicit d-wave symmetry and leads to an indirect coupling of d-wave symmetry between electrons. We show that the polaron formation by the non-linear mode can cause a pseudo-gap of d-wave symmetry before the onset of coherence in the superconducting pairing. We suggest a simple phenomenological explanation of the pseudo-gap crossover temperature and the Fermi arcs. The discussion may be relevant for the pseudo-gap in non-superconducting giant magnetoresistive manganites. © 2009 Springer Science+Business Media, LLC.

This is the first efficiency analysis of Southeast Asian water utilities that uses a double bootstrap data envelopment analysis model. A sample of 40 publicly owned water utilities was selected in the study. Six explanatory factors (i.e., non-revenue water, population density, gross domestic production per capita, average maximum temperature, dummies for state-owned enterprises and groundwater extraction) have been used to explain the differences in the technical inefficiency effects across public water utilities in Southeast Asia. We find that Southeast Asian water utilities, on average, obtained a technical efficiency of 0.74. The result reveals that the population density is linked with the technical inefficiency in the reverse direction. Furthermore, we also observe that state-owned water enterprises perform slightly lower than those from other forms of publicly-owned water utility. Policy implications are derived. © 2014 Elsevier B.V.

Nurul Syazana M.S.,Universiti Sains Malaysia
African journal of traditional, complementary, and alternative medicines : AJTCAM / African Networks on Ethnomedicines | Year: 2013

The constituents of honey's volatile compounds depend on the nectar source and differ depending on the place of origin. To date, the volatile constituents of Tualang honey have never been investigated. The objective of this study was to analyze the volatile compounds in local Malaysian Tualang honey. A continuous extraction of Tualang honey using five organic solvents was carried out starting from non-polar to polar solvents and the extracted samples were analysed using gas chromatography-mass spectrometry (GC-MS). Overall, 35 volatile compounds were detected. Hydrocarbons constitute 58.5% of the composition of Tualang honey. Other classes of chemical compounds detected included acids, aldehydes, alcohols, ketones, terpenes, furans and a miscellaneous group. Methanol yielded the highest number of extracted compounds such as acids and 5-(Hydroxymethyl) furfural (HMF). This is the first study to describe the volatile compounds in Tualang honey. The use of a simple one tube, stepwise, non-thermal liquid-liquid extraction of honey is a advantageous as it prevents sample loss. Further research to test the clinical benefits of these volatile compounds is recommended.

Hamad M.A.A.,Assiut University | Pop I.,Technical University of Cluj Napoca | Md Ismail A.I.,Universiti Sains Malaysia
Nonlinear Analysis: Real World Applications | Year: 2011

In this paper, we discuss similarity reductions for problems of magnetic field effects on free convection flow of a nanofluid past a semi-infinite vertical flat plate. The application of a one-parameter group reduces the number of independent variables by 1, and consequently the governing partial differential equation with the auxiliary conditions to an ordinary differential equation with the appropriate corresponding conditions. The differential equations obtained are solved numerically and the effects of the parameters governing the problem are discussed. Different kinds of nanoparticles were tested. © 2010 Elsevier Ltd. All rights reserved.

Lee Y.Y.,Universiti Sains Malaysia | Mahendra Raj S.,Pantai Hospital Kuala Lumpur | Graham D.Y.,Baylor College of Medicine
Helicobacter | Year: 2013

Helicobacter pylori (H. pylori) infection is etiologically associated with gastric cancer and peptic ulcer diseases which are both important public health burdens which could be largely eliminated by H. pylori eradication. However, some investigators urge caution based on the hypothesis that eradication of H. pylori may result in an increase in the incidence of gastroesophageal reflux disease, esophageal adenocarcinoma, and childhood asthma. The ethnic Malays of northeastern Peninsular Malaysia have long had a low prevalence of H. pylori infection and, as expected, the incidence of gastric cancer and its precursor lesions is exceptionally low. The availability of a population with a low H. pylori prevalence and generally poor sanitation allows separation of H. pylori from the hygiene hypothesis and direct testing of whether absence of H. pylori is associated with untoward consequence. Contrary to predictions, in Malays, erosive esophagitis, Barrett's esophagus, distal esophageal cancers, and childhood asthma are all of low incidence. This suggests that H. pylori is not protective rather the presence of H. pylori infection is likely a surrogate for poor hygiene and not an important source of antigens involved in the hygiene hypothesis. Helicobacter pylori in Malays is related to transmission from H. pylori-infected non-Malay immigrants. The factors responsible for low H. pylori acquisition, transmission, and burden of H. pylori infection in Malays remain unclear and likely involves a combination of environmental, host (gene polymorphisms), and strain virulence factors. Based on evidence from this population, absence of H. pylori infection is more likely to be boon than a bane. © 2013 John Wiley & Sons Ltd.

Paediatric endodontics is an integral part of dental practice that aims to preserve fully functional primary teeth in the dental arch. Pulpectomy of primary molars presents a unique challenge for dental practitioners. Negotiation and thorough instrumentation of bizarre and tortuous canals encased in roots programmed for physiological resorption are the main challenges for this treatment approach. Consequently, numerous in vitro and in vivo studies have been conducted to validate the application of some contemporary endodontic armamentarium for effective treatment in primary molars whilst maintaining favourable clinical outcomes. Electronic apex locators, rotary nickel-titanium files and irrigation techniques are at the forefront of endodontic armamentarium in paediatric dentistry. Hence, this review aims to map out the root and root canal morphology of primary molars, to discuss the application of electronic apex locators in primary molars and to provide an update on the preparation of their root canal systems. © 2013 International Endodontic Journal.

Yap K.S.,University of Tenaga Nasional | Lim C.P.,Universiti Sains Malaysia | Au M.T.,University of Tenaga Nasional
IEEE Transactions on Neural Networks | Year: 2011

Generalized adaptive resonance theory (GART) is a neural network model that is capable of online learning and is effective in tackling pattern classification tasks. In this paper, we propose an improved GART model (IGART), and demonstrate its applicability to power systems. IGART enhances the dynamics of GART in several aspects, which include the use of the Laplacian likelihood function, a new vigilance function, a new match-tracking mechanism, an ordering algorithm for determining the sequence of training data, and a rule extraction capability to elicit if-then rules from the network. To assess the effectiveness of IGART and to compare its performances with those from other methods, three datasets that are related to power systems are employed. The experimental results demonstrate the usefulness of IGART with the rule extraction capability in undertaking classification problems in power systems engineering. © 2006 IEEE.

Ahmad N.,Universiti Sains Malaysia
American Journal of Therapeutics | Year: 2016

Although Pakistan has a high burden of multidrug-resistant tuberculosis (MDR-TB), little is known about prevalence, management, and risk factors for adverse drug reactions (ADRs) in MDR-TB patients in Pakistan. To evaluate occurrence, management, and risk factors for ADRs in MDR-TB patients, and its impact on treatment outcomes, this observational cohort study was conducted at programmatic management unit for drug resistant TB of Lady Reading Hospital Peshawar, Pakistan. A total of 181 MDR-TB patients enrolled at the study site from January 1, 2012 to February 28, 2013 were included. Patients with drug resistant TB other than MDR-TB, transferred out patients and those who were still on treatment at the end of study duration (January 31, 2015) were excluded. Patients were followed until treatment outcomes were reported. ADRs were determined by laboratory data and/or clinical criteria. SPSS 16 was used for data analysis. A total of 131 patients (72.4%) experienced at least 1 ADR. Gastrointestinal disturbance was the most commonly observed adverse event (42%), followed by psychiatric disturbance (29.3%), arthralgia (24.3%), and ototoxicity (21%). Potentially life-threatening ADRs, such as nephrotoxicity (2.7%) and hypokalemia (2.8%) were relatively less prevalent. Owing to ADRs, treatment regimen was modified in 20 (11%) patients. On multivariate analysis, the only risk factor for ADRs was baseline body weight ≥ 40 kg (OR = 2.321, P-value = 0.013). ADRs neither led to permanent discontinuation of treatment nor adversely affected treatment outcomes. Adverse effects were prevalent in current cohort, but caused minimal modification of treatment regimen, and did not negatively impact treatment outcomes. Patient with baseline body weight ≥ 40 kg should be closely monitored. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.

The present invention relates to a system for producing L-homophenylalanine and a process for producing L-homophenylalanine using the system. The system and the process include monitoring and controlling of the reaction conditions (e.g., temperature and pH) to desired or predetermined values. The monitoring, adjusting and agitating steps provided by the method thereby result in a more complete conversion of the available substrate and produce a sufficient yield of L-homophenylalanine.

Baioumy H.M.,Universiti Sains Malaysia
Journal of African Earth Sciences | Year: 2015

Based on their occurrences and relation to the host iron ores, barites are classified into: (1) fragmented barite occurs as pebble to sand-size white to yellowish white barite along the unconformity between the Bahariya Formation and iron ores, (2) interstitial barite is present as pockets and lenses of large and pure crystals inside the iron ores interstitial barite inside the iron ores, and (3) disseminated barite occurs at the top of the iron ores of relatively large crystals of barite embedded in hematite and goethite matrix. In the current study, these barites have been analyzed for their rare earth elements (REE) as well as strontium and sulfur isotopes to assess their source and origin as well as the origin of host iron ores. Barite samples from the three types are characterized by low σREE contents ranging between 12 and 21ppm. Disseminated barite shows relatively lower σREE contents (12ppm) compared to the fragmented (19ppm) and interstitial (21ppm) barites. This is probably due to the relatively higher Fe2O3 in the disseminated barite that might dilute its σREE content. Chondrite-normalized REE patterns for the three barite mineralizations exhibit enrichment of light rare earth elements (LREE) relative to heavy rare earth elements (HREE) as shown by the high (La/Yb)N ratios that range between 14 and 45 as well as pronounced negative Ce anomalies varying between 0.03 and 0.18. The 87Sr/86Sr ratios in the analyzed samples vary between 0.707422 and 0.712237. These 87Sr/86Sr values are higher than the 87Sr/86Sr ratios of the seawater at the time of barite formation (Middle Eocene with 87Sr/86Sr ratios of 0.70773 to 0.70778) suggesting a contribution of hydrothermal fluid of high Sr isotope ratios. The δ34S values in the analyzed barites range between 14.39‰ and 18.92‰. The lower δ34S ratios in the studied barites compared with those of the seawater at the time of barite formation (Middle Eocene with δ34S ratios of 20-22‰) is attributed to a possible contribution of hydrothermal fluid of low δ34S values that lowered the δ34S values in the studied barites. Rare earth elements distribution and patterns, as well as strontium and sulfur isotopes suggest a mixing of seawater and a hydrothermal fluid as possible sources for barite mineralizations in the Bahariya Oasis. The seawater source is suggested from the low Ce/La ratios, "V" shape of the rare earth patterns and pronounced negative Ce anomalies. On the other hand, the hydrothermal fluid contribution is evident from the low concentrations of rare earth and the deviation in both S and Sr isotopic compositions from those of the seawater during the time of barites formation (Middle Eocene). The relatively heterogeneous Sr and S isotope ratios among the studied barites suggest the Bahariya Formation and Basement Complex as possible sources of the hydrothermal fluids. The similarity in the REE as well as S and Sr isotopic compositions of the three types of barite suggest that they form simultaneously. As the geology and occurrence of the barites suggest a genetic relationship between these barites and the host iron ores, the mixed seawater and hydrothermal sources model of the barites is still applicable for the source of the host iron ores. © 2015 Elsevier Ltd.

Noordin R.,Universiti Sains Malaysia
BMC research notes | Year: 2014

BACKGROUND: Helicobacter pylori is a human pathogen and during the process of infection, antigens from the bacterium elicit strong host humoral immune responses. In our previous report, native H. pylori UreG protein showed good reactivity with sera from H. pylori patients. This study was aimed at producing the recombinant form of the protein (rUreG) and determining its seroreactivities.METHODS: The coding sequence of H. pylori UreG was cloned and the recombinant protein expressed and purified by affinity chromatography using nickel nitrilotriacetic acid (Ni-NTA) resin. The antigenicity of rUreG to detect H. pylori specific antibodies was determined by western blot, using HRP-conjugated anti-human IgG and IgA antibodies as probes. A total of 70 sera, comprising 30 positive and 40 control serum samples, were used. The positive sera were from culture-positive H. pylori-infected patients with duodenal ulcers, gastric ulcers, or gastritis. The control sera comprised three types of samples without detectable H. pylori antibodies, i.e. healthy individuals (with no history of gastric disorders) (n = 10); patients who attended an endoscopy clinic (because of gastrointestinal complaints) but were H. pylori culture negative (n = 20); and people with other diseases (n = 10). Additionally, hyperimmune mice serum against rUreG was raised and tested with the native and recombinant UreG protein.RESULTS: The ureG gene fragment was successfully cloned and expressed in both soluble and insoluble forms. Western blots on rUreG protein showed 70% (21/30) and 60% (18/30) reactivity with patients' sera when probed with HRP-conjugated anti-human IgG and IgA antibodies, respectively; and the combination of the IgG and IgA western blots showed reactivity of 83.3% (25/30). By comparison, 97.5% and 92.5% of the control sera showed no reactivity when probed with HRP-conjugated anti-human IgG and IgA antibodies, respectively. Both the H. pylori lysate antigen and rUreG protein displayed a distinctive band at the expected molecular weight when probed with the hyperimmune mice serum.CONCLUSION: The rUreG protein was successfully cloned and expressed and showed good reactivity with H. pylori culture-positive patients' sera and no reactivity with most control sera. Thus, the diagnostic potential of this recombinant protein merits further investigation.

Hussein N.S.,Universiti Sains Malaysia
Saudi journal of kidney diseases and transplantation : an official publication of the Saudi Center for Organ Transplantation, Saudi Arabia | Year: 2013

Urolithiasis is a common disease with increasing incidence and prevalence world-wide, probably more common in industrialized countries. The metabolic evaluation of 24-h urine collection has been considered as part of the management of urinary stone patients. The aim of this study was to evaluate the 24-h urine constituents in stone formers and its relation to demographic data in the northeast part of Peninsular Malaysia. One hundred and six patients were recruited in this study from two hospitals in the same geographical region; 96 patients fulfilled the inclusion criteria and an informed consent was obtained from all subjects. The 24-h urine was collected in sterile bottles with a preservative agent and calcium, oxalate, citrate, uric acid, magnesium and phosphate were tested using commercial kits on a Roche Hitachi 912 chemistry analyzer. The age (mean ± SD) of 96 patients was 56.45 ± 13.43 years and 82.3% of the patients were male while 17.7% were female. The 24-h urine abnormalities were hypercalciuria (14.5%), hyperoxaluria (61.4%), hypocitraturia (57.2%), hyperuricouria (19.7%), hypomagnesuria (59.3%) and hyperphosphaturia (12.5%). Hyperoxaluria (61.4%) was the most common abnormality detected during the analysis of 24-h urine constituents in contradiction to industrial countries, where hypercalciuria was the most common finding. The high frequencies of hypomagnesuria and hypocitraturia reflect the important role of magnesium and citrate in stone formation and their prophylactic role in the treatment of urinary stone disease in the given population.

Bhat R.,Universiti Sains Malaysia | Sridhar K.R.,Mangalore University
Journal of Food Composition and Analysis | Year: 2011

Electron spin resonance (ESR) spectroscopy was used to detect the free radicals that were naturally present in lotus seeds or that were formed after employing various food processing methods (e.g., irradiation, microwave roasting, pan frying, grinding or pounding) by placing small portions of lotus seed (seed coat and cotyledon) in KCl powder in ESR quartz tubes. Spectral analysis revealed the presence of an insignificant natural abundance of free radicals and showed a sharp and clear signal at g=2.002, more prominent in seed coat. Exposure to gamma radiation (0-30kGy, the recommended dose for quarantine purposes) resulted in a dose-dependent increase of signal intensity at g=2.002 with the seed coat exhibiting the presence of a weak triplet (aH=3mT) which can be used to authenticate irradiation treatments. Irradiated cotyledon at high doses (15 and 30kGy) revealed significant reduction in ESR signals, attributed to an increase of free radical scavengers. Common food processing practices like microwave roasting, flame heating, grinding or pounding also generated free radicals. It is envisaged that results of the present study might be valuable for health conscious consumers who are interested in the status of free radicals in foodstuffs subjected to traditional or modern food-processing techniques. © 2011 Elsevier Inc.

Umar M.,RMIT University | Roddick F.,RMIT University | Fan L.,RMIT University | Aziz H.A.,Universiti Sains Malaysia
Chemosphere | Year: 2013

The extensive use of Bisphenol A (BPA) in the plastics industry has led to increasing reports of its presence in the aquatic environment, with concentrations of ngL-1 to μgL-1. Various advanced oxidation processes, including ozonation, have been shown to effectively degrade BPA. This paper reviews the current advancements in using ozone to remove BPA from water and wastewater. Most of the published work on the oxidation of BPA by ozone has focused on the efficiency of BPA removal in terms of the disappearance of BPA, and the effect of various operational parameters such as ozone feed rate, contact time and pH; some information is available on the estrogenic activity of the treated water. Due to increasing operational reliability and cost effectiveness, there is great potential for industrial scale application of ozone for the treatment of BPA. However, there is a significant lack of information on the formation of oxidation by-products and their toxicities, particularly in more complex matrices such as wastewater, and further investigation is needed for a better understanding of the environmental fate of BPA. © 2012 Elsevier Ltd.

Hassan S.H.,Universiti Sains Malaysia
British Food Journal | Year: 2011

Purpose: Conflicting values are resolved through a process called value negotiation, but the nature of this process remains largely unexplored. This study aims to explore how consumers undergoing rapid socio-economic transition manage their conflicting values in making choices concerning functional foods. Design/methodology/approach: Data for this study were collected qualitatively using ethnoconsumerist and grounded-theory methodologies. In combination, these two approaches enabled the researcher to conduct research at the emic-level (within culture). Findings: The exploratory model was developed to illustrate how the main three ethnic groups in Malaysia manage their values in terms of functional food consumption. The results showed that participants did not spend much time consciously considering their consumption choices or their values until they were faced with choices or personal values that were inconsistent with cultural, physical and product characteristics. Values are managed by prioritisation and balancing to suit the participant's health needs and situation. Research limitations/implications: The study's findings are based only on the Malay, Chinese and Indian ethnic groups in Malaysia. Practical implications: The model can be used to help food practitioners, policy-makers and educators evaluate practices aimed at improving dietary behaviour. Originality/value: The finding gives new insight into how consumers in developing multicultural society consume functional foods. © Emerald Group Publishing Limited.

Romano N.,James Cook University | Romano N.,Universiti Sains Malaysia | Zeng C.,James Cook University
Reviews in Fisheries Science | Year: 2013

Nitrogenous wastes including ammonia-N, nitrite-N, and nitrate-N are increasingly becoming a global issue in aquatic ecosystems due to escalating anthropogenic activities and are a ubiquitous concern in aquaculture. These pollutants are interrelated via the nitrification cycle, with the direct metabolic product ammonia-N generally being the most toxic with high species specificity. Furthermore, while environmental factors influencing nitrogenous waste toxicity are similar, the causative underlying mechanisms are often substantially different. In this review, we focus on decapod crustaceans due to their high commercial value and likelihood of encountering these pollutants in their benthic or near-benthic habitat. While a large body of publications exists in this area, to date a comprehensive literature review on relative toxicities of all three nitrogenous wastes, physiological consequences, and adaptive mechanisms of crustaceans is lacking. Understanding these processes will likely have implications for environmental/fisheries management and the aquaculture industry. Additionally, there are strong indications that theoretical "safe" values, traditionally used for predicting toxicity thresholds, substantially underestimate the impact of nitrogenous waste on the growth and physiological condition of crustaceans. These consequences will be emphasized along with various methods of uptake, elimination, and detoxification that ultimately explain differences in nitrogenous waste toxicity to decapod crustaceans. © 2013 Copyright Taylor and Francis Group, LLC.

Chuah-Petiot M.S.,Universiti Sains Malaysia
Polish Botanical Journal | Year: 2011

The checklist gives 764 species and infra-specific taxa, 127 genera and 39 families reported for Malaysia, comprising 38 families, 122 genera and 758 taxa for Hepaticae, and also 6 taxa belonging to 5 genera and 1 family for Anthocerotae. The families with the largest number of species are Lejeuneaceae (282 taxa), Lepidoziaceae (110), Frullaniaceae (67), Plagiochilaceae (52), Geocalycaceae (36), Lophoziaceae and Radulacéae (35 taxa each). The genera with large numbers of species include Cololejeunea (84 taxa), Frullania (67), Bazzania (53), Plagiochila (47) and Radula (35). Brief information on the distribution of known Hepaticae and Anthocerotae in Malaysia is provided.

Yusup Y.,Universiti Sains Malaysia
Journal of Wind Engineering and Industrial Aerodynamics | Year: 2012

Drag coefficient (C D) in the urban roughness sublayer over industrialized and urban equatorial areas under low wind conditions are reported in this paper. An observation tower was set up in (1) the field of the Institusi Teknologi Tunku Abdul Rahman in the middle of the Prai Industrial Park (5°22'N, 100°23'E), employing a Gill UVW propeller anemometer and a temperature sensor placed at a height of 10m above the ground level and (2) on the top of a faculty building in Universiti Sains Malaysia (USM) (5°21'N, 100°18'E), employing a sonic anemometer at 18m above the ground level. Meteorological data were collected for three months in the years 2006 and 2010. Monin-Obukhov similarity theory using local scales was first tested at the sites studied and was found to be applicable. The relationships between C D and mean wind speed, V, local friction velocity, u l, and atmospheric stability, l, are also discussed (subscript "l" denotes local). Generally, C D is strongly dependent and increased with u *l for both sites. C D was also confirmed to be influenced by atmospheric stability where it is at its maximum when u *l (and V) is large, which generally occurs in neutral atmospheric conditions. This relationship was seen at both sites, suggesting its generality. Lastly, the measured C DN value obtained was also used to calculate C GN, geostrophic drag coefficient (=1.9×10 -3), which is similar to the reported values in the literature. © 2012 Elsevier Ltd.

Bandyopadhyay A.,Universiti Sains Malaysia
Indian Journal of Medical Research | Year: 2011

Background & objectives: Pulmonary function tests have been evolved as clinical tools in diagnosis, management and follow up of respiratory diseases as it provides objective information about the status of an individual's respiratory system. The present study was aimed to evaluate pulmonary function among the male and female young Kelantanese Malaysians of Kota Bharu, Malaysia, and to compare the data with other populations.Methods: A total of 128 (64 males, 64 females) non-smoking healthy young subjects were randomly sampled for the study from the Kelantanese students' population of the University Sains Malaysia, Kota Bharu Campus, Kelantan, Malaysia. The study population (20-25 yr age group) had similar socio-economic background. Each subject filled up the ATS (1978) questionnaire to record their personal demographic data, health status and consent to participate in the study. Subjects with any history of pulmonary diseases were excluded from the study. Results: The pulmonary function measurements exhibited significantly higher values among males than the females. FEV 1% did not show any significant inter-group variation probably because the parameter expresses FEV 1 as a percentage of FVC. FVC and FEV 1 exhibited significant correlations with body height and body mass among males whereas in the females exhibited significant correlation with body mass, body weight and also with age. FEV 1% exhibited significant correlation with body height and body mass among males and with body height in females. FEF 25-75% did not show any significant correlation except with body height among females. However, PEFR exhibited significant positive correlation with all the physical parameters except with age among the females. On the basis of the existence of significant correlation between different physical parameters and pulmonary function variables, simple and multiple regression norms have been computed. Interpretation & conclusions: From the present investigation it can be concluded that Kelantanese Malaysian youths have normal range of pulmonary function in both the sexes and the computed regression norms may be used to predict the pulmonary function values in the studied population.

Yahaya B.,Universiti Sains Malaysia
The Scientific World Journal | Year: 2012

Understanding the mechanisms underlying the process of regeneration and repair of airway epithelial structures demands close characterization of the associated cellular and molecular events. The choice of an animal model system to study these processes and the role of lung stem cells is debatable since ideally the chosen animal model should offer a valid comparison with the human lung. Species differences may include the complex three-dimensional lung structures, cellular composition of the lung airway as well as transcriptional control of the molecular events in response to airway epithelium regeneration, and repair following injury. In this paper, we discuss issues related to the study of the lung repair and regeneration including the role of putative stem cells in small- and large-animal models. At the end of this paper, the author discuss the potential for using sheep as a model which can help bridge the gap between small-animal model systems and humans. © 2012 B. Yahaya.

Lee L.W.,Universiti Sains Malaysia
Computer Assisted Language Learning | Year: 2016

With the advent of touch-screen interfaces on the tablet computer, multisensory elements in reading instruction have taken on a new dimension. This computer assisted language learning research aimed to determine whether specific technology features of a tablet computer can add to the functionality of multisensory instruction in early reading acquisition. The effects of multisensory elements from the different modalities (letter card and iPad) on bilingual readers' natural abilities to blend and segment non-words were compared. The quasi-experimental post-test study involved 56 high- and low-ability Malay–English Grade 2 students. Multisensory-based materials to build and to break apart non-words in both letter card and iPad modalities were experimented. The results indicated no significant difference in the effect of the multisensory modalities on blending and segmenting tasks. As both conventional letter cards and touch-screen tablet computers produced similar outcomes, the practical implication is that both are equally adequate for providing the multisensory component in multisensory instruction. The writing systems (Malay and English), the type of tasks (blending and segmenting), and extreme groups (high- and low-performing) did not moderate the effects of the multisensory modalities. © 2016 Taylor & Francis

Sharma J.N.,Kuwait University | Kesavarao U.,Universiti Sains Malaysia
International Journal of Immunopathology and Pharmacology | Year: 2011

The present study examined the left ventricular wall thickness (LVWT), total urinary kallikrein, total plasma kininogen and mean arterial blood pressure (MABP) in diabetic and non-diabetic Wistar Kyoto (WKY) rats. The MABP was significantly raised (P<0.01) in diabetic WKY rats compared to the respective controls. The LVWT was also significantly (P<0.01) increased in diabetic WKY rats than that of control WKY rats. The mean total urinary kallikrein level and the mean total plasma kininogen level were higher (P<0.01) in diabetic WKY rats, when these rats were treated with captopril (40 mg/kg and 80 mg/kg) against the mean value obtained from control WKY rats. In conclusion, this investigation suggests that diabetes induced in these rats can cause hypertension, increased LVWT and changes in the BK-forming components. Captopril treatment caused reduction in MABP, regression of LVWT and alterations in bradykinin (BK)-forming components. The possible significance of these observations is discussed. Copyright © by BIOLIFE, s.a.s.

Universiti Sains Malaysia | Date: 2012-06-12

The present invention provides a composition including a polar organic extract of

Universiti Sains Malaysia | Date: 2012-02-28

(R)-6-(dimethylamino)-4,4-diphenylheptan-3-one and a process to produce thereof.

The present invention relates to a system (

Saharudin K.A.,Universiti Sains Malaysia | Sreekantan S.,Universiti Sains Malaysia | Lai C.W.,University of Malaya
Materials Science in Semiconductor Processing | Year: 2014

One-dimensional TiO2 nanotube arrays produced by the anodization of Ti foil at 60 V in an ethylene glycol bath containing ammonium fluoride and 1 wt% H2O holds a promise as a photocatalyst for degradation of methyl orange. However, as-anodized TiO2 nanotubes are amorphous in nature, imposing constraints on the potent use of this nanostructure. To address this issue, the as-anodized TiO2 nanotubes were annealed in inert (argon), reducing (nitrogen), or oxidizing (oxygen) atmosphere at 500 C for 4 h. The amorphous TiO2 nanotubes were successfully transform into anatase phase after annealing. In this study, the TiO2 nanotubes annealed in argon exhibited the highest degradation rate of methyl orange (MO) solution under ultraviolet irradiation among the samples. The degradation rate was approximately 98% after 5 h, which may be ascribed to the large amount of oxygen vacancies and defects (carbon) within the Ar-TiO2 sample that simultaneously increased the degradation rate of MO. Oxygen vacancies and defects could be favorable in capturing photoinduced e- during the photocatalytic reaction such that the recombination of e- and h + could be effectively inhibited. © 2013 Elsevier Ltd.

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.

Ofori-Boateng C.,Universiti Sains Malaysia | Lee K.T.,Universiti Sains Malaysia | Mensah M.,Kwame Nkrumah University Of Science And Technology
Fuel Processing Technology | Year: 2013

In 2010, the total generated municipal solid waste (MSW) in Ghana was 4.5 million tons. About 90% of the total MSW generated is not effectively managed but dumped in unauthorized places creating serious burden on human health. With a population growth rate of about 3.4% per year, Ghana is predicted to face big challenges in waste management. One effective way of managing solid waste is to recover the potent energy from them through waste-to-energy (WTE) plants such as engineered landfilling and controlled incineration. Cost assessment of power generation based on MSW in Ghana showed that the average cost of electricity for landfill gas power plants with already existing closed engineered landfill emerged as the cheapest (USD 0.039/kWh) compared to landfilling without engineered sites and controlled incineration. Moreover, the average domestic employment per megawatt energy generated is higher at approximately 185 for existing engineered landfills compared to the other technologies. Engineered landfill sites are under construction in Ghana whose average power extraction would be between 1 and 2 MW. Thus a potentially sustainable way of managing MSW in Ghana is through the construction of WTE plants to generate electricity. © 2012 Elsevier B.V. All rights reserved.

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).

Mujeebu M.A.,Universiti Sains Malaysia | Abdullah M.Z.,Universiti Sains Malaysia | Mohamad A.A.,Alfaisal University | Bakar M.Z.A.,Universiti Sains Malaysia
Progress in Energy and Combustion Science | Year: 2010

Porous media combustion (PMC) has interesting advantages compared with free flame combustion due to higher burning rates, increased power dynamic range, extension of the lean flammability limits, and low emissions of pollutants. Extensive experimental and numerical works were carried out and are still underway, to explore the feasibility of this interesting technology for practical applications. For this purpose, numerical modeling plays a crucial role in the design and development of promising PMC systems. This article provides an exhaustive review of the fundamental aspects and emerging trends in numerical modeling of gas combustion in porous media. The modeling works published to date are reviewed, classified according to their objectives and presented with general conclusions. Numerical modeling of liquid fuel combustion in porous media is excluded. © 2010 Elsevier Ltd. All rights reserved.