Browse publications by year: 2011

  1. Normaniza Osman, Mohamad Nordin Abdullah, Faisal Haji Ali
    Sains Malaysiana, 2011;40:1065-1073.
    Rapid development in hilly areas in Malaysia has become a trend that put a stress to the sloping area. It reduces the factor of safety by reducing the resistant force and therefore leads to slope failure. Vegetation plays a big role in reinforcement functions via anchoring the soils and forms a binding network within the soil layer that tied the soil masses together. In this research, three plant species namely Acacia mangium, Dillenia suffruticosa and Leucaena leucocephala were assessed in term of their soil-root shear strength properties. Our results showed that Acacia mangium had the highest shear strength values, 30.4 kPa and 50.2 kPa at loads 13.3 kPa and 24.3 kPa, respectively. Leucaena leucocephala showed the highest in cohesion factor, which was almost double the value in those of Dillenia suffruticosa and Acacia mangium. The root profile analysis indicated Dillenia suffruticosa exhibited the highest values in both root length density and root volume, whilst Leucaena leucocephala had the highest average of root diameter.
    MeSH terms: Acacia; Fabaceae; Malaysia; Research; Soil; Plant Roots; Shear Strength; Dilleniaceae; Physical Phenomena
  2. Yap C, Chee M, Shamarina S, Edward F, Chew W, Tan S
    Sains Malaysiana, 2011;40:1053-1064.
    Coastal water samples were collected from 20 sampling sites in the southern part of Peninsular Malaysia. Seven physico-chemical parameters were measured directly in-situ while water samples were collected and analysed for 6 dissolved trace metal concentrations. The surface water (0-20 cm) physico-chemical parameters including temperature, salinity, dissolved oxygen (DO), pH, total dissolved solids (TDS), specific conductance (SpC) and turbidity while the dissolved trace metals were Cd, Cu, Fe, Ni, Pb and Zn. The ranges for the physico-chemical parameters were 28.07-35.6ºC for temperature, 0.18-32.42 ppt for salinity, 2.20-12.03 mg/L for DO, 5.50-8.53 for pH, 0.24-31.65 mg/L for TDS, 368-49452 μS/cm for SpC and 0-262 NTU for turbidity while the dissolved metals (mg/L) were 0.013-0.147 for Cd, 0.024-0.143 for Cu, 0.266- 2.873 for Fe, 0.027-0.651 for Ni, 0.018-0.377 for Pb and 0.032-0.099 for Zn. Based on multivariate analysis (including correlation, cluster and principal component analyses), the polluted sites were found at Kg. Pasir Puteh and Tg. Kupang while Ni and Pb were identified as two major dissolved metals of high variation in the coastal waters. Therefore, water quality monitoring and control of release of untreated anthropogenic wastes into rivers and coastal waters are strongly needed.
  3. Hossain M, Oh MJ
    Sains Malaysiana, 2011;40:1049-1052.
    Lymphocystis disease (LCD) in fishes is caused by the agent called lymphocystis disease virus (LCDV). LCDV is a chronic and benign virus. The disease affects 96 species of marine and fresh water fishes ranged among 34 families in the world. Affected fish with LCD has a typical external symptom with clusters consisted of enormously hypertrophied dermal cells on the skin and fins. The hypertrophied cells, generally named lymphocystis cells, have a thick hyaline capsule, an enlarged nucleus and prominent basophilic cytoplasmic inclusions. Among the four species of fishes, olive flounder Paralichthys olivaceus, and rockfish Sebastes schlegeli were marine cultured fish, and gourami Trichogaster leeri and painted glassfish Channa baculis were freshwater ornamental fish. Although LCD causes low mortality, the disfigurement of infected fish can make them unsellable. Thus LCD has resulted in an important economic loss in the aquaculture industry. This study of histopathology may be adequate for a presumptive diagnosis of lymphocystis diseases both in marine and freshwater fish species.
    MeSH terms: Animals; Inclusion Bodies; Fishes; Flounder; Fresh Water; Hyalin; Iridoviridae; Aquaculture; Olea; Animal Fins
  4. Kaur S, Waheeda Azwa, Norliza Mohd Fadzil, Azrin E. Ariffin
    Sains Malaysiana, 2011;40:1325-1329.
    This study was conducted to compare the treatment outcome using patching in patients with strabismic amblyopia and refractive amblyopia. The treatment outcome was measured by visual acuity and refractive error. A total of 28 patients participated in this study. One group comprised of strabismic amblyopes who had either congenital esotropia or intermittent exotropia and spherical equivalent refractive error of less than -3.00 DS. Another group of patients were purely refractive amblyopes. Patients were first corrected with the best correction for a month. When the VA in the amblyopic eye did not improve over the month, then patching treatment was started. Patching was done daily for 2 h together with near activity. The treatment was carried out for 4 months, with the patients reviewed once every month. The results of the study revealed that VA improved by 17 alphabets or 3 lines after patching treatment for patients with strabismic amblyopia. In the refractive amblyopia group, the VA only improved by 8 alphabets or 1 line 3 alphabets. The mean spherical equivalent refractive error changed by less than -0.50DS and therefore was clinically not significant in both groups. This present study showed that patching treatment was better at improving the VA of patients with strabismic amblyopia.
    MeSH terms: Amblyopia; Esotropia; Exotropia; Humans; Refractive Errors; Visual Acuity; Treatment Outcome
  5. Tze JC, Han CL
    Sains Malaysiana, 2011;40:1319-1323.
    Schizophrenia is a debilitating psychiatric syndrome that affects 1% of the world’s population. Abnormalities in immune functions and role of inflammatory markers have been widely described in schizophrenia. With the alarming high prevalence, this study aims to investigate the association of acute phase proteins with schizophrenia. We investigated the serum proteome of 20 schizophrenic patients and 20 healthy controls using two-dimensional gel electrophoresis and mass spectrometry. The spots were analysed using Image Master 2D Platinum software. In total, we have detected 774 protein spots in human serum and found that three of them showed altered changes in schizophrenic patients, as compared to healthy controls. Among these acute phase proteins, haptoglobin (p = 0.003) and two isoforms of apolipoprotein A-I (p = 0.004, p = 0.003) were found to be significantly decreased in patients, as compared to controls. Our findings support the hypothesis that inflammatory response system is linked to the pathophysiology of schizophrenia.
  6. Asma Alhusna Abang Abdullah, Nurul Asyikin Yahya
    Sains Malaysiana, 2011;40:1313-1317.
    Fixed orthodontic treatment requires the use of orthodontic brackets and archwires in order to correct malocclusions. The objective of this study was to evaluate the pattern of orthodontic material usages i.e. bracket and archwire among Malaysian orthodontists. A self-administered questionnaire was distributed to members of the Malaysian Association of Orthodontist. Data entry and statistical analysis was done using SPSS version 15.0. Descriptive statistics were used for analysis. Means and standard deviations were calculated for continuous variables, frequency and percentages for categorical variables. Thirty-four orthodontists responded to the survey, with 76% (n=26) were female and the mean age was 43.31 years (SD 8.76). Most respondents used conventional metal brackets (60%, n=60) and most bracket prescription used was MBT (56%, n=19). At levelling stage, most respondents used nickel titanium archwire (84.5%, n=47). Stainless steel archwire was the most favourable choice for retraction/space closure stage (73.9%, n=34). At finishing, most respondents (60.4%, n=29) preferred to use stainless steel wire in their cases. As a conclusion, specific types of orthodontic materials were preferred and used by Malaysian orthodontists in delivering orthodontic treatment.
    MeSH terms: Orthodontists; Alloys; Female; Malocclusion; Nickel; Surveys and Questionnaires; Stainless Steel; Titanium; Orthodontic Brackets
  7. Gobithaasan R, Kenjiro T. Miura
    Sains Malaysiana, 2011;40:1301-1305.
    A planar spiral called Generalized Log Aesthetic Curve segment (GLAC) has been proposed using the curve synthesis process with two types of formulation; ρ-shift and κ-shift. Both methods were carried out by extending the formulation of Generalized Cornu Spiral (GCS) in a similar manner to the Log Aesthetic Curve (LAC). The family of GLAC comprises of planar curves of high quality such as GCS, LAC, clothoid, logarithmic spiral and circle involute. The GLAC segment has an additional parameter to determine its shape as compared to GCS and LAC segment, hence an extra constraint can be satisfied when shaping the GLAC segment. The last section of the paper shows a numerical example.
  8. Norfifah Bachok, Anuar Ishak
    Sains Malaysiana, 2011;40:1297-1300.
    This paper presents a numerical analysis of a stagnation-point flow towards a nonlinearly stretching/shrinking sheet immersed in a viscous fluid. The stretching/shrinking velocity and the external flow velocity impinges normal to the stretching/shrinking sheet are assumed to be in the form U ~ xm, where m is a constant and x is the distance from the stagnation point. The governing partial differential equations are converted into ordinary ones by a similarity transformation, before being solved numerically. The variations of the skin friction coefficient and the heat transfer rate at the surface with the governing parameters are graphed and tabulated. Different from a stretching sheet, it is found that the solutions for a shrinking sheet are non-unique for m > 1/3.
    MeSH terms: Hot Temperature; Skin; Friction; Physical Phenomena; Hydrodynamics
  9. Kartini Ahmad, Roslinda Nazar, Pop I
    Sains Malaysiana, 2011;40:1291-1296.
    In this paper, the steady Falkner-Skan solution for gravity-driven film flow of a micropolar fluid is theoretically investigated. The resulting nonlinear ordinary differential equations are solved numerically using an implicit finite-difference scheme. The results obtained for the skin friction coefficient as well as the velocity and microrotation or angular velocity profiles are shown in table and figures for different values of the material or micropolar parameter K.
    MeSH terms: Gravitation; Paper; Friction; Physical Phenomena
  10. Pauzi Abdullah M, Soh SC
    Sains Malaysiana, 2011;40:1255-1261.
    A survey undertaken in Peninsular Malaysia has shown that volatile organic compounds (VOCs), both chlorinated and non-chlorinated, are present in selected drinking water samples. In this study, analyses of VOCs were performed by means of solid phase microextraction (SPME) with a 100 μm polydimethylsiloxane (PDMS) fibre followed by gas chromatography - mass spectrometry detector (GC-MSD). Samples from different points of the distribution system networks were taken and analysed for 54 VOCs of different chemical families. The results of the study indicated that chloroform constituted the major portion of the VOCs in all samples analysed. In addition to trihalomethanes (THMs), other abundant compounds detected were cis and trans-1,2-dichloroethylene, trichloroethylene, 1,2-dibromoethane, benzene, toluene, ethylbenzene, chlorobenzene, 1,4-dichlorobenzene and 1,2-dichlorobenzene. However, the measured concentrations did not exceed the National Guideline for Drinking Water Quality 2000 in any case. No clear relationship between the status of development of a state in Malaysia to the levels and types of VOCs detected in its drinking water was noted. Nevertheless, the finding of anthropogenic chemicals, even at low concentrations, gave credibility to the viewpoint that improper development and disposal practices threatened the purity of the drinking water.
  11. Syazana N, Hashida N, Majid A, Durriyyah H, Durriyah Sharifah HA, KAMARUDDIN M
    Sains Malaysiana, 2011;40:1243-1246.
    The present study aimed to elucidate the possible protective effects of Gelam honey on sperm quality and testis histology against infertility related problems. Control and treated groups of 4 - 5 weeks old male Sprague-Dawley rats were force-fed daily with 1.0 mL/100 g body weight of normal saline (0.9%) and Gelam honey, respectively. After 60 days of treatments, reproductive organs of the anesthetized rats were removed to assess sperm parameters and histology of testis. Sperm count of treated group was significantly higher (18.85±3.72×105/mL) than control group (17.05±3.12×105/mL) (p<0.05). Based on sperm morphology, treated group showed significantly higher percentage of normal sperm (96.83±0.03%) as compared to control group (94.87±0.01%) (p<0.01). Head and tail abnormalities sperm were also significantly reduced in the treated rats (p<0.05). The number of spermatogenic cells in testis of treated group were abundant as compared to control group. Seminiferous tubules of treated group were densely packed with spermatogenic cells with small lumen filled up with sperm tail. This study suggested that Gelam honey has the potential to increase the fertility of male rats by increasing sperm count and number of sperm with normal morphology.
  12. Ainon Hamzah, Tavakoli A, Amir Rabu
    Sains Malaysiana, 2011;40:1231-1235.
    Toluene (C7H8) a hydrocarbon in crude oil, is a common contaminant in soil and groundwater. In this study, the ability to degrade toluene was investigated from twelve bacteria isolates which were isolated from soil contaminated with oil. Out of 12 bacterial isolates tested, most of Pseudomonas sp. showed the capability to grow in 1 mM of toluene compared with other isolates on the third day of incubation. Based on enzyme assays towards toluene monooxygenase, Pseudomonas aeruginosa UKMP-14T and Bacillus cereus UKMP-6G were shown to have the highest ability to degrade toluene. The toluene monoxygenase activity was analysed by using two calorimetric methods, Horseradish peroxidase (HRP) and indole-indigo. Both of the methods measured the production of catechol by the enzymatic reaction of toluene monooxygenase. In the HRP assay, the highest enzyme activity was 0.274 U/mL, exhibited by Pseudomonas aeruginosa UKMP-14T. However, for indole-indigo assay, Bacillus cereus UKMP-6G produced the highest enzyme activity of 0.291 U/ml. Results from both experiments showed that Pseudomonas aeruginosa UKMP-14T and Bacillus cereus UKMP-6G were able to degrade toluene.
    MeSH terms: Bacillus cereus; Catechols; Horseradish Peroxidase; Hydrocarbons; Mixed Function Oxygenases; Indigo Carmine; Indoles; Petroleum; Pseudomonas; Pseudomonas aeruginosa; Soil; Toluene; Enzyme Assays; Groundwater
  13. Khairil M, Wan Juliana W, Nizam M, Faszly R
    Sains Malaysiana, 2011;40:1209-1221.
    A study was conducted to determine the tree species composition, diversity and estimate of above ground biomass at Chini watershed forest. Three types of forest were identified. Thirty plots of 0.1 ha were established in the inland, seasonal flood and riverine forests. A total of 3974 trees with diameter at breast height (dbh) at 5.0 cm and above were recorded. The inland forest recorded 2061 individuals representing 393 species from 164 genera and 57 families; the seasonal flood forest, 1019 individuals representing 268 species from 137 genera and 57 families; and the riverine forest, 894 individuals representing 260 species from 133 genera and 53 families. Endospermum diadenum (Euphorbiaceae), Streblus elongatus (Moraceae) and Aporusa arborea (Euphorbiaceae) was the most important species in the inland forest, seasonal flood forest and the riverine forest, with Importance Value Index (SIVi) of 3.36%, 4.43% and 2.96%, respectively. Euphorbiaceae was the most important family in the inland and riverine forest with FIVi of 14.25% and 12.91% and Myrtaceae in the seasonal flood forest at 12.36%. The Shannon-Weiner diversity index (H’) were considered high in all three forest types at 5.40 (H’max = 5.97) in the inland forest, 5.10 (H’max = 5.54) at the seasonal flood forest and 5.08 (H’max = 5.56) for the riverine forest. Shannon evenness index (J’) in the three types of forest was 0.9. The Sorenson’s community similarity coefficient (CCs) showed that tree species communities between the three forest types had low similarities with CCs= 0.4. The total above ground biomass estimated in the inland forest was 366.2 tan/ha, in the seasonal flood forest was 379.8 tan/ha and in the riverine forest was 401.1 tan/ha. A total of 44 endemic species in Peninsular Malaysia were found and 104 species were listed in the checklist of Conservation Status of Malaysian Trees that utilized the 2009 IUCN Red List Categories by World Conservation Monitoring Centre (WCMC).
  14. Shahrizim Zulkifly, Young SK, Mohamed Abudl Majid, Amir Feisal Merican
    Sains Malaysiana, 2011;40:1201-1208.
    Lichen samples were collected from Gunung Machincang, Langkawi Islands based on an alternation of altitudes, which are 0, 300 and above 600 m. Morphological identification resulted in 15 genera of microlichens (crustose) and five genera of macrolichens (foliose) and they fall under 14 families. As the altitude increases, the number of foliose type of lichen also increased. The common microlichens obtained were from the Family of Graphidaceae and can be found from the sea level right up to the peak of Gunung Machincang. The most common crustose lichens found were Heterodermia sp., while Eugenia sp. is the most common tree habitat for lichens in Gunung Machincang, Langkawi Islands. This study represents the first record of lichens in Gunung Machincang, Langkawi Islands, Malaysia.
    MeSH terms: Accidental Falls; Eugenia; Altitude; Ascomycota; Exanthema; Lichens; Malaysia; Trees; Ecosystem; Islands
  15. Nor Azlin M, Lyn SK
    Sains Malaysiana, 2011;40(12):1461-1465.
    A controlled, single blinded experimental study was conducted to determine the effects of passive joint mobilization on pain and stairs ascending-descending time in subjects with knee osteoarthritis (OA knee). A total of 22 subjects aged 40 and above with mild and moderate OA knee were assigned to either passive knee mobilization plus conventional physiotherapy (experimental group) or conventional physiotherapy alone (control group). Both groups received 2 therapy sessions per week, for 4 weeks. A blinded assessor measured pain with Visual analogue scale and stairs ascending-descending time with Aggregated Locomotor Function test, at baseline and at week 4. There was a significant reduction in pain among subjects in the experimental group (18.07 mm, t = 3.48, p = 0.01) compared to the control group (6.66 mm, t = 0.44, p = 0.67). Non-significant clinical difference was found in stairs ascending-descending time between the two groups (i.e. 6.25s in the experimental group versus 6.78 s in the control group, F(1,10) = 0.70, p = 0.42). No significant correlation was found between pain score and stairs ascending-descending time, r = 0.34, p = 0.16. The addition of passive joint mobilization to conventional physiotherapy reduced pain but not stairs ascending-descending time among subjects with knee osteoarthritis.
    MeSH terms: Hospitals, University; Humans; Knee Joint; Malaysia; Pain; Pain Measurement; Osteoarthritis, Knee; Physical Therapy Modalities; Control Groups; Visual Analog Scale
  16. Tunc C
    Sains Malaysiana, 2011;40:1455-1459.
    The main purpose of this paper is to introduce some new instability theorems related to certain fourth and fifth order nonlinear differential equations with a constant delay. By means of the Lyapunov-Krasovskii functional approach, we obtained two new results on the topic.
    MeSH terms: Neural Networks (Computer); Nonlinear Dynamics
  17. Habshah Midi, Bagheri A, Rahmatullah Imon A
    Sains Malaysiana, 2011;40:1437-1447.
    Outliers in the X-direction or high leverage points are the latest known source of multicollinearity. Multicollinearity is a nonorthogonality of two or more explanatory variables in multiple regression models, which may have important influential impacts on interpreting a fitted regression model. In this paper, we performed Monte Carlo simulation studies to achieve two main objectives. The first objective was to study the effect of certain magnitude and percentage of high leverage points, which are two important issues in tending the high leverage points to be collinearity-enhancing observations, on the multicollinarity pattern of the data. The second objective was to investigate in which situations these points do make different degrees of multicollinearity, such as moderate or severe. According to the simulation results, high leverage points should be in large magnitude for at least two explanatory variables to guarantee that they are the cause of multicollinearity problems. We also proposed some practical Lower Bound (LB) and Upper Bound (UB) for High Leverage Collinearity Influential Measure (HLCIM) which is an essential measure in detecting the degree of multicollinearity. A well-known example is used to confirm the simulation results.
    MeSH terms: Monte Carlo Method; Regression Analysis; Multivariate Analysis; Biophysical Phenomena
  18. Grosan T
    Sains Malaysiana, 2011;40:1429-1435.
    The effect of thermal dispersion on the steady free convection flow of a nanofluid in a vertical channel is investigated numerically using a single phase model. Considering the laminar and fully developed flow regime a simplified mathematical model is obtained. In the particular cases when solid phase and thermal dispersion effects are neglected the problem was solved analytically. The numerical solution is shown to be in excellent agreement with the close form analytical solution. Nusselt number enhancement with the Grashof number, volume fraction and thermal diffusivity constant increasing has been found.
    MeSH terms: Models, Theoretical; Convection; Thermal Diffusion; Physical Phenomena
  19. Mohd Syafiq Hamdan, Norazzizi Nordin, Fathrita Mohd Amir, Mohamed Rozali Othman
    Sains Malaysiana, 2011;40:1421-1427.
    In this study, two nickel based electrodes were prepared; nickel foil and nickel-polyvinylchloride (Ni-PVC), in order to study their electrochemical behavior using cyclic voltammetry, CV and chronocoulometry, CC. Ni electrode was prepared from Ni metal foil while Ni-PVC electrode was prepared by mixing a weighed portion of Ni powder and PVC in THF solvent, swirled until the suspension was homogeneous and drying the suspension in an oven at 50oC for 3 h. The dry sample was then placed in a 1 cm diameter stainless steel mould and pressed at 10 ton/cm2. From CV data, Ni-PVC electrode showed a better electrochemical behavior compared to Ni metal foil electrode. The use of Ni-PVC electrode at higher concentration of supporting electrolyte (1.0 M KOH) was better than at lower concentration of the same supporting electrolyte in electroxidation of ethanol. In addition to acetic acid, the oxidation of ethanol also produced ethyl acetate and acetaldehyde.
    MeSH terms: Acetaldehyde; Ethanol; Electrodes; Electrolytes; Nickel; Polyvinyl Chloride; Solvents; Stainless Steel; Acetic Acid
  20. Maaruf A, Noroul Asyikeen Z, Sahilah A, Khan MA
    Sains Malaysiana, 2011;40:1413-1419.
    This study focused on the isolation of yeast from a variety of Malaysian local fruits which can potentially be employed as a leavening agent in bakery products. A total of 6 yeast strains (SKS2, SMK9, SDB10, SRB11, SS12, SM16) were isolated from palm kernel pulp (Cocos nucifera L.), longan (Dimocarpus longan spp. malesianus Leenh), soursop (Annona muricata L.), bamboo shoot (Bambusa vulgaris), snake fruit (Salacca zalacca) and mango (Mangifera indica) using an enrichment procedure which can enhance the growth of yeast colonies and eliminat the fruits worm. The isolates were identified as Saccharomyces cerevisiae, through observation of the yeast cells morphology under microscope, temperature tolerance and fermentative capacity test. The leavening ability of the identified yeasts were examined by fermenting dough. Fermentation proofing was carried out at 30±5°C with 85% humidity for 120 min. The bread doughs were baked at 180°C for 8 min. Results showed that the yeast strains SRB11, SM16, SS12 and SMK9 were able to leaven the highest specific volume of 3.68 cm3/g, 3.41 cm3/g, 3.37 cm3/g and 3.23 cm3/g, respectively. Strain SDB10 and commercial yeast showed less ability with specific volume of 3.02 cm3/g and 2.84 cm3/g, respectively. Thus, the new yeast isolates from local fruits showed much superior with specific volume of more than 3.02 cm3/g.
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