Displaying publications 201 - 220 of 493 in total

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  1. Farah ‘Atiqah Abdul Azam, Roslinda Shamsudin, Zalita Zainuddin, Muhammad Azmi Abdul Hamid, Min Hwei Ng, Rashita Abdul Rashid
    Sains Malaysiana, 2018;47:2141-2149.
    Bioactive composites consist of pseudowollastonite and mullite synthesized from natural resources was developed for
    bone implant applications. To realize such applications, a mechanical test of these composites and in vitro bioactivity in
    SBF solution were studied. The present paper reports pseudowollastonite synthesized from the rice husk ash and limestone
    reinforced with 10, 20 and 30 wt. % of mullite. Influence of sintering temperature, phase composition, morphology towards
    mechanical properties of various pseudowollastonite-mullite (PSW-M) composites was examined prior to the bioactivity
    test. It was found that pseudowollastonite with the addition of 20 wt. % of mullite sintered at 1150°C gave the best result
    for diametral tensile strength (DTS) and hardness with the value of 8.8 ± 0.15 MPa and 3.79 ± 0.13 GPa, respectively.
    The obvious increment in the mechanical strength was due to the formation of liquid phase CaAl2
    O3
    during sintering at
    1150°C. In addition, the formation of fibrous apatite (HA) layer of amorphous calcium phosphate (ACP) with Ca/P ratio
    1.8 on PSW20M sample confirmed the good bioactivity of the composite.
  2. Maryam Rukayyah Al-Munirah Binti Ayob, Mohamad Shukri Bin Abdul Hamid, Faezzah Binti Mohd Daud, Ong Yi Sean
    MyJurnal
    The role of individual healthy behaviors like physical activity, nutrition and stress management on reduction of rate of disease mortality and morbidity is well known. The aim of this study is to determine healthy lifestyle in lecturers employed in School of Quantitative Sciences, University Utara Malaysia, in 2019. Materials and Methods: The participants of this cross-sectional study were 66 lecturers in School of Quantitative Sciences, selected via random sampling method. The data collection was performed using a questionnaire including demographic healthy lifestyle questions. Analysis of the data was performed through Software Statistical Analysis System Enterprise Guide (SAS EG) version 7.1. Results: The mean age of the subjects was 42.68 ± 1.37 years and, BMI mean was 24.13 ± 0.86. 92.42% of them were married and 7.58% also were single. Conclusion: According to the results, planning for lecturers in School of Quantitative Sciences for receiving information about healthy lifestyle on weight control and nutrition are important.
  3. Muhammad Fakhrurazi Ahmad Fadzil, Siti Selina Abdul Hamid, Siti Najila Mohd Janib, Azahari Kasbollah, Syed Asraf Fahlawi Wafa
    MyJurnal
    Medical radioisotope is a small quantity of radioactive substance used in safe, cost effective, for the
    purpose of diagnostic and therapy of various diseases. In Malaysia, the emerging of new nuclear
    medicine centers or institutions in both government and private sectors rose abruptly for the past few
    years. Currently, there are no data available on the usage and demand of medial radioisotope or
    radiopharmaceuticals. Understanding the usage trending and demand of radiopharmaceuticals and
    medical radioisotope is essential when related to technology changes in order to meet the market size
    of these radiopharmaceuticals. Survey result found out that the highest demand and the highest usage
    among all radioisotopes are Technetium-99m and Radioiodine isotopes such as the Iodine-131, Iodine-
    131 MIBG, Iodine-123 and Iodine-123 MIBG. Currently, most of the medical isotopes and
    radiopharmaceuticals are currently imported. Technetium-99m is the backbone of nuclear medicine
    whereby more than 80% of Nuclear Medicine services utilize this radioisotope. Technetium-99m supply
    chain is unstable globally and in coming future, two main reactors (Canada & Holland) that produces
    60% of world Molybdenum-99 will shut down the operation and supply of Molybdenum-99 will be
    disrupted. As for radioiodine services, currently, Iodine-123 can't be obtained in Malaysia and
    neighboring countries due to its short half-life. Iodine-123 is useful in diagnostic of thyroid related
    diseases. As for PET services, the highest demands are F-18 FDG and Gallium-68 Generator for the
    moment. However the survey data still did not, include most of the PET centers in the Klang Valley,
    northern area (Penang) and the new upcoming PET center in Southern Region (Malacca and Johor).
    It is important for Malaysia to self-produced medical radioisotope and radiopharmaceuticals to meet
    the market and local demand of these medical isotopes.
  4. Zarei M, Ghanbari R, Tajabadi N, Abdul-Hamid A, Bakar FA, Saari N
    J Food Sci, 2016 Feb;81(2):C341-7.
    PMID: 26720491 DOI: 10.1111/1750-3841.13200
    Palm kernel cake protein was hydrolyzed with different proteases namely papain, bromelain, subtilisin, flavourzyme, trypsin, chymotrypsin, and pepsin to generate different protein hydrolysates. Peptide content and iron-chelating activity of each hydrolysate were evaluated using O-phthaldialdehyde-based spectrophotometric method and ferrozine-based colorimetric assay, respectively. The results revealed a positive correlation between peptide contents and iron-chelating activities of the protein hydrolysates. Protein hydrolysate generated by papain exhibited the highest peptide content of 10.5 mM and highest iron-chelating activity of 64.8% compared with the other hydrolysates. Profiling of the papain-generated hydrolysate by reverse phase high performance liquid chromatography fractionation indicated a direct association between peptide content and iron-chelating activity in most of the fractions. Further fractionation using isoelectric focusing also revealed that protein hydrolysate with basic and neutral isoelectric point (pI) had the highest iron-chelating activity, although a few fractions in the acidic range also exhibited good metal chelating potential. After identification and synthesis of papain-generated peptides, GGIF and YLLLK showed among the highest iron-chelating activities of 56% and 53%, whereas their IC50 were 1.4 and 0.2 μM, respectively.
  5. Ghanbari R, Zarei M, Ebrahimpour A, Abdul-Hamid A, Ismail A, Saari N
    Int J Mol Sci, 2015 Dec 04;16(12):28870-85.
    PMID: 26690117 DOI: 10.3390/ijms161226140
    In recent years, food protein-derived hydrolysates have received considerable attention because of their numerous health benefits. Amongst the hydrolysates, those with anti-hypertensive and anti-oxidative activities are receiving special attention as both activities can play significant roles in preventing cardiovascular diseases. The present study investigated the angiotensin-I converting enzyme (ACE) inhibitory and anti-oxidative activities of Actinopyga lecanora (A. lecanora) hydrolysates, which had been prepared by alcalase, papain, bromelain, flavourzyme, pepsin, and trypsin under their optimum conditions. The alcalase hydrolysate showed the highest ACE inhibitory activity (69.8%) after 8 h of hydrolysis while the highest anti-oxidative activities measured by 2,2-diphenyl 1-1-picrylhydrazyl radical scavenging (DPPH) (56.00%) and ferrous ion-chelating (FIC) (59.00%) methods were exhibited after 24 h and 8 h of hydrolysis, respectively. The ACE-inhibitory and anti-oxidative activities displayed dose-dependent trends, and increased with increasing protein hydrolysate concentrations. Moreover, strong positive correlations between angiotensin-I converting enzyme (ACE) inhibitory and anti-oxidative activities were also observed. This study indicates that A. lecanora hydrolysate can be exploited as a source of functional food owing to its anti-oxidant as well as anti-hypertension functions.
  6. Yeong LT, Abdul Hamid R, Saiful Yazan L, Khaza'ai H, Mohtarrudin N
    BMC Complement Altern Med, 2015;15(1):431.
    PMID: 26638207 DOI: 10.1186/s12906-015-0954-3
    Drastic increment of skin cancer incidence has driven natural product-based chemoprevention as a promising approach in anticancer drug development. Apart from its traditional usages against various ailments, Ardisia crispa (Family: Myrsinaceae) specifically its triterpene-quinone fraction (TQF) which was isolated from the root hexane extract (ACRH) was recently reported to exert antitumor promoting activity in vitro. This study aimed at determining chemopreventive effect of TQF against chemically-induced mouse skin tumorigenesis as well as elucidating its possible pathway(s).
  7. Chow PW, Abdul Hamid Z, Chan KM, Inayat-Hussain SH, Rajab NF
    Toxicol Appl Pharmacol, 2015 Apr 1;284(1):8-15.
    PMID: 25645895 DOI: 10.1016/j.taap.2015.01.016
    Hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs) are sensitive targets for benzene-induced hematotoxicity and leukemogenesis. The impact of benzene exposure on the complex microenvironment of HSCs and HPCs remains elusive. This study aims to investigate the mechanism linking benzene exposure to targeting HSCs and HPCs using phenotypic and clonogenic analyses. Mouse bone marrow (BM) cells were exposed ex vivo to the benzene metabolite, 1,4-benzoquinone (1,4-BQ), for 24h. Expression of cellular surface antigens for HSC (Sca-1), myeloid (Gr-1, CD11b), and lymphoid (CD45, CD3e) populations were confirmed by flow cytometry. The clonogenicity of cells was studied using the colony-forming unit (CFU) assay for multilineage (CFU-GM and CFU-GEMM) and single-lineage (CFU-E, BFU-E, CFU-G, and CFU-M) progenitors. 1,4-BQ demonstrated concentration-dependent cytotoxicity in mouse BM cells. The percentage of apoptotic cells increased (p < 0.05) following 1,4-BQ exposure. Exposure to 1,4-BQ showed no significant effect on CD3e(+) cells but reduced the total counts of Sca-1(+), CD11b(+), Gr-1(+), and CD45(+) cells at 7 and 12 μM (p < 0.05). Furthermore, the CFU assay showed reduced (p < 0.05) clonogenicity in 1,4-BQ-treated cells. 1,4-BQ induced CFU-dependent cytotoxicity by significantly inhibiting colony growth for CFU-E, BFU-E, CFU-G, and CFU-M starting at a low concentration of exposure (5μM); whereas for the CFU-GM and CFU-GEMM, the inhibition of colony growth was remarkable only at 7 and 12μM of 1,4-BQ, respectively. Taken together, 1,4-BQ caused lineage-related cytotoxicity in mouse HPCs, demonstrating greater toxicity in single-lineage progenitors than in those of multi-lineage.
  8. Ganjali Dashti M, Abdeshahian P, Wan Yusoff WM, Kalil MS, Abdul Hamid A
    Biomed Res Int, 2014;2014:831783.
    PMID: 25147817 DOI: 10.1155/2014/831783
    The biosynthesis of biomedical products including lipid and gamma-linolenic acid (GLA) by Cunninghamella bainieri 2A1 was studied in repeated batch fermentation. Three key process variables, namely, glucose concentration, ammonium tartrate concentration, and harvesting time, were optimized using response surface methodology. Repeated batch fermentation was carried out by the cultivation of Cunninghamella bainieri 2A1 in nitrogen-limited medium with various nitrogen concentration (1-4 g/L) and glucose concentration (20-40 g/L) at three time intervals (12 h, 24 h, and 48 h). Experimental results showed that the highest lipid concentration of 6.2 g/L and the highest GLA concentration of 0.4 g/L were obtained in optimum conditions, where 20.2 g/L glucose, 2.12 g/L ammonium tartrate, and 48 h harvesting time were utilized. Statistical results showed that the interaction between glucose and ammonium tartrate concentration had highly significant effects on lipid and GLA biosynthesis (P < 0.01). Moreover, harvesting time had a significant interaction effect with glucose and ammonium tartrate concentration on lipid production (P < 0.05).
  9. Manickam MA, Abdul Mutalip MH, Abdul Hamid HA, Kamaruddin RB, Sabtu MY
    Asia Pac J Public Health, 2014 Sep;26(5 Suppl):91S-9S.
    PMID: 25038196 DOI: 10.1177/1010539514542194
    Alcohol is deleterious to physical and mental health as well as social well-being. This study aims to examine the prevalence of alcohol consumption and factors associated with its use among school-going Malaysian adolescents. The Global School-Based Student Health Survey (GSHS) 2012 employed 2-stage clustering design to Malaysian secondary school respondents aged 12 to 17 years. The prevalence of current alcohol usage was 8.9% (95% confidence interval [CI]: 7.8-10.07) overall, 11.2% (95% CI: 9.80-12.80) among males, and 23.4 (95% CI: 21.40-25.50) among Chinese students. Multivariate logistic regression showed that adolescents who had used alcohol were more likely to have used substance (adjusted odds ratio [aOR] = 3.39; 95% CI: 2.33-4.99), experienced injury (aOR = 1.53; 95% CI: 1.20-1.95), and engaged in sexual behaviors (aOR = 1.42, 95% CI: 1.12-1.79), and fights (aOR = 1.23; 95% CI: 1.08-1.41). The current national policies on alcohol should be strengthened to curb alcohol consumption among adolescents.
    Study name: Global School-Based Student Health Survey (GSHS)
  10. Khamaiseh EI, Abdul Hamid A, Abdeshahian P, Wan Yusoff WM, Kalil MS
    ScientificWorldJournal, 2014;2014:395754.
    PMID: 24672315 DOI: 10.1155/2014/395754
    The production of biobutanol was studied by the cultivation of Clostridium acetobutylicum NCIMB 13557 in P2 medium including date fruit as the sole substrate. The effect of P2 medium and the effect of different concentrations of date fruit ranging from 10 to 100 g/L on biobutanol production were investigated. Anaerobic batch culture was carried out at 35 °C incubation temperature and pH 7.0 ± 0.2 for 72 h. Experimental results showed that the lowest yield of biobutanol and acetone-butanol-ethanol (ABE) was 0.32 and 0.35 gram per gram of carbohydrate consumed (g/g), respectively, when an initial date fruit concentration of 10 g/L was utilized. At this fruit date concentration a biobutanol production value of 1.56 g/L was obtained. On the other hand, the maximum yield of biobutanol (0.48 g/g) and ABE (0.63 g/g) was produced at 50 g/L date fruit concentration with a biobutanol production value as high as 11 g/L. However, when a higher initial date fruit concentration was used, biobutanol and ABE production decreased to reach the yield of 0.22 g/g and 0.35 g/g, respectively, where 100 g/L date fruit was used. Similar results also revealed that 10.03 g/L biobutanol was produced using 100 g/L date fruit.
  11. Yeong LT, Abdul Hamid R, Saiful Yazan L, Khaza'ai H, Awang Hamsin DE
    Nat Prod Res, 2014;28(22):2026-30.
    PMID: 24836304 DOI: 10.1080/14786419.2014.917415
    An isomeric mixture of α,β-amyrin (triterpene) and 2-methoxy-6-undecyl-1,4-benzoquinone (quinone) isolated from the Ardisia crispa root hexane (ACRH) extract was reported to possess anti-inflammatory properties in vivo. Considering the close association between inflammation and cancer, on top of the lack of antitumour study on those compounds, this study aimed to determine the potential of both compounds against tumour promotion in vitro, either as single agent or in combination. Triterpene and quinone compounds, as well as triterpene-quinone fraction (TQF) and ACRH were subjected to inhibition of Epstein-Barr virus-early antigen (EBV-EA) activation assay for that purpose. Compared with curcumin (positive control), inhibition against EBV-EA activation occurred in the order: ACRH>TQF ≥ curcumin>α,β-amyrin ≥ 2-methoxy-6-undecyl-1,4-benzoquinone. These findings reported, for the first time, the antitumor-promoting effect of α,β-amyrin and 2-methoxy-6-undecyl-1,4-benzoquinone from the roots of A. crispa, which was enhanced when both compounds act in synergy.
  12. Abdul Rahman A, Abdul Karim N, Abdul Hamid NA, Harun R, Ngah WZ
    Oxid Med Cell Longev, 2013;2013:189129.
    PMID: 24381713 DOI: 10.1155/2013/189129
    Mechanisms determining both functional rate of decline and the time of onset in aging remain elusive. Studies of the aging process especially those involving the comparison of long-lived individuals and young controls are fairly limited. Therefore, this research aims to determine the differential gene expression profile in related individuals from villages in Pahang, Malaysia. Genome-wide microarray analysis of 18 samples of peripheral blood mononuclear cells (PBMCs) from two groups: octo/nonagenarians (80-99 years old) and their offspring (50.2 ± 4.0 years old) revealed that 477 transcripts were age-induced and 335 transcripts were age-repressed with fold changes ≥1.2 in octo/nonagenarians compared to offspring. Interestingly, changes in gene expression were associated with increased capacity for apoptosis (BAK1), cell cycle regulation (CDKN1B), metabolic process (LRPAP1), insulin action (IGF2R), and increased immune and inflammatory response (IL27RA), whereas response to stress (HSPA8), damage stimulus (XRCC6), and chromatin remodelling (TINF2) pathways were downregulated in octo/nonagenarians. These results suggested that systemic telomere maintenance, metabolism, cell signalling, and redox regulation may be important for individuals to maintain their healthy state with advancing age and that these processes play an important role in the determination of the healthy life-span.
  13. Abedini A, Daud AR, Abdul Hamid MA, Kamil Othman N, Saion E
    Nanoscale Res Lett, 2013;8(1):474.
    PMID: 24225302 DOI: 10.1186/1556-276X-8-474
    This review presents an introduction to the synthesis of metallic nanoparticles by radiation-induced method, especially gamma irradiation. This method offers some benefits over the conventional methods because it provides fully reduced and highly pure nanoparticles free from by-products or chemical reducing agents, and is capable of controlling the particle size and structure. The nucleation and growth mechanism of metallic nanoparticles are also discussed. The competition between nucleation and growth process in the formation of nanoparticles can determine the size of nanoparticles which is influenced by certain parameters such as the choice of solvents and stabilizer, the precursor to stabilizer ratio, pH during synthesis, and absorbed dose.
  14. Bordbar S, Ebrahimpour A, Abdul Hamid A, Abdul Manap MY, Anwar F, Saari N
    Biomed Res Int, 2013;2013:849529.
    PMID: 23586061 DOI: 10.1155/2013/849529
    The stone fish (Actinopyga lecanora) ethanolic and methanolic tissue extracts were investigated for total phenolic contents (TPCs) as well as antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH(•)) radical scavenging activity and ferric reducing antioxidant power (FRAP) assays. Both extracts showed low amount of phenolics (20.33 to 17.03 mg of gallic acid equivalents/100 g dried sample) and moderate antioxidant activity (39% to 34% DPPH(•) radical scavenging activity and 23.95 to 22.30 mmol/100 mL FeSO4 FRAP value). Enzymatic proteolysis was carried out in order to improve the antioxidant activity using six commercially available proteases under their optimum conditions. The results revealed that the highest increase in antioxidant activity up to 85% was obtained for papain-generated proteolysate, followed by alcalase (77%), trypsin (75%), pepsin (68%), bromelain (68%), and flavourzyme (50%) as measured by DPPH(•) radical scavenging activity, whilst for the FRAP value, the highest increase in the antioxidant activity up to 39.2 mmol/100 mL FeSO4 was obtained for alcalase-generated proteolysate, followed by papain (29.5 mmol/100 mL FeSO4), trypsin (23.2 mmol/100 mL FeSO4), flavourzyme (24.7 mmol/100 mL FeSO4), bromelain (22.9 mmol/100 mL FeSO4), and pepsin (20.8 mmol/100 mL FeSO4). It is obvious that proteolysis of stone fish tissue by proteolytic enzymes can considerably enhance its antioxidant activity.
  15. Abdul Hamid Z, Budin SB, Wen Jie N, Hamid A, Husain K, Mohamed J
    J Zhejiang Univ Sci B, 2012 Mar;13(3):176-85.
    PMID: 22374609 DOI: 10.1631/jzus.B1100133
    Paracetamol (PCM) overdose can cause nephrotoxicity with oxidative stress as one of the possible mechanisms mediating the event. In this study, the effects of ethyl acetate extract of Zingiber zerumbet rhizome [200 mg per kg of body weight (mg/kg) and 400 mg/kg] on PCM-induced nephrotoxicity were examined. Rats were divided into five groups containing 10 rats each. The control group received distilled water while other groups were treated with extract alone (400 mg/kg), PCM alone (750 mg/kg), 750 mg/kg PCM+200 mg/kg extract (PCM+200-extract), and 750 mg/kg PCM+400 mg/kg extract (PCM+400-extract), respectively, for seven consecutive days. The Z. zerumbet extract was given intraperitoneally concurrent with oral administration of PCM. Treatment with Z. zerumbet extract at doses of 200 and 400 mg/kg prevented the PCM-induced nephrotoxicity and oxidative impairments of the kidney, as evidenced by a significantly reduced (P<0.05) level of plasma creatinine, plasma and renal malondialdehyde (MDA), plasma protein carbonyl, and renal advanced oxidation protein product (AOPP). Furthermore, both doses were also able to induce a significant increment (P<0.05) of plasma and renal levels of glutathione (GSH) and plasma superoxide dismutase (SOD) activity. The nephroprotective effects of Z. zerumbet extract were confirmed by a reduced intensity of renal cellular damage, as evidenced by histological findings. Moreover, Z. zerumbet extract administered at 400 mg/kg was found to show greater protective effects than that at 200 mg/kg. In conclusion, ethyl acetate extract of Z. zerumbet rhizome has a protective role against PCM-induced nephrotoxicity and the process is probably mediated through its antioxidant properties.
  16. Sarmadi B, Aminuddin F, Hamid M, Saari N, Abdul-Hamid A, Ismail A
    Food Chem, 2012 Sep 15;134(2):905-11.
    PMID: 23107706 DOI: 10.1016/j.foodchem.2012.02.202
    Fat, alkaloid and polyphenol contents of two clones of cocoa (UIT1 and PBC 140) were removed and the remaining powder was autolyzed at pH 3.5 and 5.2. Based on the results, autolysates of UIT produced at pH 3.5 exhibited the highest ability to inhibit α-amylase activity. However, no α-glucosidase inhibition activity was observed under the conditions specified. Autolysates produced under pH 3.5 caused the highest amount of insulin secretion. In streptozotocin-diabetic rats, all cocoa autolysates significantly decreased blood glucose at 4h. To assure that the results from the assays were not due to the polyphenols of cocoa autolysates qualitative and quantitative tests were applied. According to their results cocoa autolysates were found to be free from polyphenols. Analysis of amino acid composition revealed that cocoa autolysates were abundant in hydrophobic amino acids. It can be suggested that besides other compounds of cocoa, its peptides and amino acids could contribute to its health benefits.
  17. Umar KM, Abdulkarim SM, Radu S, Abdul Hamid A, Saari N
    ScientificWorldJournal, 2012;2012:529031.
    PMID: 22645428 DOI: 10.1100/2012/529031
    A mimicked biosynthetic pathway of catechin metabolite genes from C. sinensis, consisting of flavanone 3 hydroxylase (F3H), dihydroflavonol reductase (DFR), and leucoanthocyanidin reductase (LCR), was designed and arranged in two sets of constructs: (a) single promoter in front of F3H and ribosome-binding sequences both in front of DFR and LCR; (b) three different promoters with each in the front of the three genes and ribosome-binding sequences at appropriate positions. Recombinant E. coli BL (DE3) harbouring the constructs were cultivated for 65 h at 26 °C in M9 medium consisting of 40 g/L glucose, 1 mM IPTG, and 3 mM eriodictyol. Compounds produced were extracted in ethyl acetate in alkaline conditions after 1 h at room temperature and identified by HPLC. Two of the four major catechins, namely, (-)-epicatechin (0.01) and (-)-epicatechin gallate (0.36 mg/L), and two other types ((+)-catechin hydrate (0.13 mg/L) and (-)-catechin gallate (0.04 mg/L)) were successfully produced.
  18. Al-Shami SA, Md Rawi CS, Ahmad AH, Abdul Hamid S, Mohd Nor SA
    Ecotoxicol Environ Saf, 2011 Jul;74(5):1195-202.
    PMID: 21419486 DOI: 10.1016/j.ecoenv.2011.02.022
    Abundance and diversity of benthic macroinvertebrates as well as physico-chemical parameters were investigated in five rivers of the Juru River Basin in northern Peninsula Malaysia: Ceruk Tok Kun River (CTKR), Pasir River (PR), Permatang Rawa River (PRR), Kilang Ubi River (KUR), and Juru River (JR). The physico-chemical parameters and calculated water quality index (WQI) were significantly different among the investigated rivers (ANOVA, P<0.05). The WQI classified CTKR, PR, and JR into class III (slightly polluted). However, PRR and KUR fell into class IV (polluted). High diversity and abundance of macroinvertebrates, especially the intolerant taxa, Ephemeroptera, Plecoptera, and Trichoptera, were observed in the least polluted river, CTKR. Decreasing abundance of macroinvertebrates followed the deterioration of river water quality with the least number of the most tolerant taxa collected from PR. On the basis of composition and sensitivity of macroinvertebrates to pollutants in each river, the highest Biological Monitoring Working Party (BMWP) index score of 93 was reported in CTKR (good water quality). BMWP scores in PRR and JR were 38.7 and 20.1, respectively, classifying both of them into "moderate water quality" category. Poor water quality was reported in PR and KUR. The outcome of the multivariate analysis (CCA) was highly satisfactory, explaining 43.32% of the variance for the assemblages of macroinvertebrates as influenced by 19 physical and chemical variables. According to the CCA model, we assert that there were three levels of stresses on macroinvertebrate communities in the investigated rivers: Level 1, characterized of undisturbed or slightly polluted as in the case of CTKR; Level 2, characterized by a lower habitat quality (the JR) compared to the CTKR; and Level 3 showed severe environmental stresses (PRR, PR, and KUR) primarily contributed by agricultural, industrial, and municipal discharges.
  19. Ting HN, Chia SY, Abdul Hamid B, Mukari SZ
    J Voice, 2011 Nov;25(6):e305-9.
    PMID: 21429707 DOI: 10.1016/j.jvoice.2010.05.007
    The acoustic characteristics of sustained vowel have been widely investigated across various languages and ethnic groups. These acoustic measures, including fundamental frequency (F(0)), jitter (Jitt), relative average perturbation (RAP), five-point period perturbation quotient (PPQ5), shimmer (Shim), and 11-point amplitude perturbation quotient (APQ11) are not well established for Malaysian Malay young adults. This article studies the acoustic measures of Malaysian Malay adults using acoustical analysis. The study analyzed six sustained Malay vowels of 60 normal native Malaysian Malay adults with a mean of 21.19 years. The F(0) values of Malaysian Malay males and females were reported as 134.85±18.54 and 238.27±24.06Hz, respectively. Malaysian Malay females had significantly higher F(0) than that of males for all the vowels. However, no significant differences were observed between the genders for the perturbation measures in all the vowels, except RAP in /e/. No significant F(0) differences between the vowels were observed. Significant differences between the vowels were reported for all perturbation measures in Malaysian Malay males. As for Malaysian Malay females, significant differences between the vowels were reported for Shim and APQ11. Multiethnic comparisons indicate that F(0) varies between Malaysian Malay and other ethnic groups. However, the perturbation measures cannot be directly compared, where the measures vary significantly across different speech analysis softwares.
  20. Ting HN, Zourmand A, Chia SY, Yong BF, Abdul Hamid B
    J Voice, 2012 Sep;26(5):664.e1-6.
    PMID: 22285457 DOI: 10.1016/j.jvoice.2011.08.008
    The formant frequencies of Malaysian Malay children have not been well studied. This article investigates the first four formant frequencies of sustained vowels in 360 Malay children aged between 7 and 12 years using acoustical analysis. Generally, Malay female children had higher formant frequencies than those of their male counterparts. However, no significant differences in all four formant frequencies were observed between the Malay male and female children in most of the vowels and age groups. Significant differences in all formant frequencies were found across the Malay vowels in both Malay male and female children for all age groups except for F4 in female children aged 12 years. Generally, the Malaysian Malay children showed a nonsystematic decrement in formant frequencies with age. Low levels of significant differences in formant frequencies were observed across the age groups in most of the vowels for F1, F3, and F4 in Malay male children and F1 and F4 in Malay female children.
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