Displaying publications 1 - 20 of 106 in total

Abstract:
Sort:
  1. Fulltext Molybdate reduction by Pseudomonas sp. strain DRY2
    Shukor MY, Ahmad SA, Nadzir MM, Abdullah MP, Shamaan NA, Syed MA
    J Appl Microbiol, 2010 Jun;108(6):2050-8.
    PMID: 19968732 DOI: 10.1111/j.1365-2672.2009.04604.x
    To isolate and characterize a potent molybdenum-reducing bacterium.
  2. Determinants of depression and insomnia among institutionalized elderly people in Malaysia
    Shahar S, Hassan J, Sundar VV, Kong AY, Ping Chin S, Ahmad SA, et al.
    Asian J Psychiatr, 2011 Sep;4(3):188-95.
    PMID: 23051116 DOI: 10.1016/j.ajp.2011.06.001
    Depression and insomnia are common psychiatric disorders among elderly people and reported to be related to several social and health factors. However, their occurrences in relation to food intake have rarely been investigated. Therefore, this study was to identify determinants of depression and insomnia, with emphasised on food intake among 71 elderly people residing in a government funded institution in Malaysia. An interview based questionnaire was used to obtain information on socio-demography, health and functional status, depression, insomnia and food intake. A total of 71.8% subjects had depression and 53% had insomnia. Subjects who had insomnia [Adjusted Odds Ratio (AOR) 19.55, 95% CI=4.04-94.64], needed help/unable to perform >4 items of IADL (AOR=16.65, 95% CI=3.95-70.22), had hypertension (AOR=7.66, 95% CI=1.37-42.76), had >50% wastage of poultry or fish (AOR=3.66, 95% CI=1.06-12.60) and wastage of vegetables (AOR 3.31, 95% CI=1.03-10.60) were more likely to have depression. Subjects who had depression (AOR 19.55, 95% CI=4.04-94.64), needed help/unable to perform >4 items of IADL (AOR 2.97, 95% CI=1.12-7.84), needed help/unable to handle financial matters (AOR 5.01, 95% CI=1.37-18.27) and had >50% wastage of vegetables (AOR 3.91, 95% CI=1.42-10.82) were at a higher risk to develop insomnia. Depression and insomnia affected more than half of the subjects, interrelated, and associated with functional inability, socioeconomic factor and high food wastage of specific foods.
  3. Determinants of smoking behaviour among secondary school students in Bangladesh
    Rahman MM, Ahmad SA, Karim MJ, Chia HA
    J Community Health, 2011 Oct;36(5):831-8.
    PMID: 21359500 DOI: 10.1007/s10900-011-9382-6
    Despite established country's tobacco control law, cigarette smoking by the young people and the magnitude of nicotine dependence among the students is alarming in Bangladesh. This study was aimed to determine the prevalence of smoking and factors influencing it among the secondary school students. A two-stage cluster sampling was used for selection of schools with probability proportional to enrollment size followed by stratified random sampling of government and private schools. The 70-item questionnaire included 'core GYTS' (Global Youth Tobacco Survey) and other additional questions were used to collect relevant information. Analysis showed that the prevalence of smoking was 12.3% among boys and 4.5% among girls, respectively. The mean age at initiation of smoking was 10.8 years with standard deviation of 2.7 years. Logistic regression analysis revealed that boys are 2.282 times likely to smoked than girls and it was 1.786 times higher among the students aged 16 years and above than their younger counterparts. Smoking by teachers appeared to be the strong predictor for students smoking behaviour (OR 2.206, 95% CI: 1.576, 3.088) followed by peer influence (OR 1.988, 95% CI: 1.178, 3.356). Effective smoking prevention program should to be taken to reduce smoking behaviour. The school curricula had less impact in preventing smoking except teacher's smoking behaviour.
  4. Enhanced phenol degradation by immobilized Acinetobacter sp. strain AQ5NOL 1
    Ahmad SA, Shamaan NA, Arif NM, Koon GB, Shukor MY, Syed MA
    World J Microbiol Biotechnol, 2012 Jan;28(1):347-52.
    PMID: 22806810 DOI: 10.1007/s11274-011-0826-z
    A locally isolated Acinetobacter sp. Strain AQ5NOL 1 was encapsulated in gellan gum and its ability to degrade phenol was compared with the free cells. Optimal phenol degradation was achieved at gellan gum concentration of 0.75% (w/v), bead size of 3 mm diameter (estimated surface area of 28.26 mm(2)) and bead number of 300 per 100 ml medium. At phenol concentration of 100 mg l(-1), both free and immobilized bacteria exhibited similar rates of phenol degradation but at higher phenol concentrations, the immobilized bacteria exhibited a higher rate of degradation of phenol. The immobilized cells completely degrade phenol within 108, 216 and 240 h at 1,100, 1,500 and 1,900 mg l(-1) phenol, respectively, whereas free cells took 240 h to completely degrade phenol at 1,100 mg l(-1). However, the free cells were unable to completely degrade phenol at higher concentrations. Overall, the rates of phenol degradation by both immobilized and free bacteria decreased gradually as the phenol concentration was increased. The immobilized cells showed no loss in phenol degrading activity after being used repeatedly for 45 cycles of 18 h cycle. However, phenol degrading activity of the immobilized bacteria experienced 10 and 38% losses after the 46 and 47th cycles, respectively. The study has shown an increased efficiency of phenol degradation when the cells are encapsulated in gellan gum.
  5. Isolation and characterization of a phenol-degrading Rhodococcus sp. strain AQ5NOL 2 KCTC 11961BP
    Arif NM, Ahmad SA, Syed MA, Shukor MY
    J Basic Microbiol, 2013 Jan;53(1):9-19.
    PMID: 22581645 DOI: 10.1002/jobm.201100120
    In this work, we report on the isolation of a phenol-degrading Rhodococcus sp. with a high tolerance towards phenol. The isolate was identified as Rhodococcus sp. strain AQ5NOL 2, based on 16S rDNA analysis. The strain degraded phenol using the meta pathway, a trait shared by many phenol-degraders. In addition to phenol biodegradation, the strain was also capable of degrading diesel. Strain AQ5NOL 2 exhibited a broad optimum temperature for growth on phenol at between 20 °C and 35 °C. The best nitrogen sources were ammonium sulphate, glycine or phenylalanine, followed by proline, nitrate, leucine, and alanine (in decreasing efficiency). Strain AQ5NOL 2 showed a high tolerance and degradation capacity of phenol, for it was able to register growth in the presence of 2000 mg l(-1) phenol. The growth of this strain on phenol as sole carbon and energy source were modeled using Haldane kinetics with a maximal specific growth rate (μ(max)) of 0.1102 hr(-1), a half-saturation constant (K(s) ) of 99.03 mg l(-1) or 1.05 mmol l(-1), and a substrate inhibition constant (K(i)) of 354 mg l(-1) or 3.76 mmol l(-1). Aside from phenol, the strain could utilize diesel, 2,4-dinitrophenol and ρ-cresol as carbon sources for growth. Strain AQ5NOL 2 exhibited inhibition of phenol degradation by Zn(2+), Cu(2+), Cr(6+), Ag(+) and Hg(2+) at 1 mg l(-1).
  6. Fulltext A quantitative approach to measure women's sexual function using electromyography: a preliminary study of the Kegel exercise
    Mohktar MS, Ibrahim F, Mohd Rozi NF, Mohd Yusof J, Ahmad SA, Su Yen K, et al.
    Med Sci Monit, 2013 Dec 13;19:1159-66.
    PMID: 24335927 DOI: 10.12659/MSM.889628
    BACKGROUND: Currently, the reference standard used to clinically assess sexual function among women is a qualitative questionnaire. Hence, a generalised and quantitative measurement tool needs to be available as an alternative. This study investigated whether an electromyography (EMG) measurement technique could be used to help quantify women's sexual function.

    MATERIAL AND METHODS: A preliminary intervention study was conducted on 12 female subjects, who were randomised into a control (n=6) and an intervention (n=6) group. Intervention involved a set regimen of pelvic floor muscle exercises (Kegel) and the control group did not have any treatment. All subjects were asked to answer a validated, self-rated Pelvic Organ Prolapse/Urinary Incontinence Sexual Function Questionnaire (PISQ). EMG measurements of the pelvic floor muscles (PFM) and the abdominal muscles were taken from all women at recruitment and 8 weeks after study commencement.

    RESULTS: After 8 weeks, most of the subjects in the control group did not display any noted positive difference in either PISQ score (4/6) or in their muscle strength (4/6). However, a noted progressive difference were observed in subjects who were placed in the Kegel group; PISQ score (5/6) and muscles strength (4/6).

    CONCLUSIONS: The noted difference in the Kegel group subjects was that if progress is observed in the sexual function, improvement is also observed in the strength of at least 2 types of muscles (either abdominal or PFM muscles). Thus, EMG measurement is a potential technique to quantify the changes in female sexual function. Further work will be conducted to validate this assumption.

  7. Fulltext Hexavalent molybdenum reduction to mo-blue by a sodium-dodecyl-sulfate-degrading Klebsiella oxytoca strain DRY14
    Halmi MI, Zuhainis SW, Yusof MT, Shaharuddin NA, Helmi W, Shukor Y, et al.
    Biomed Res Int, 2013;2013:384541.
    PMID: 24383052 DOI: 10.1155/2013/384541
    Bacteria with the ability to tolerate, remove, and/or degrade several xenobiotics simultaneously are urgently needed for remediation of polluted sites. A previously isolated bacterium with sodium dodecyl sulfate- (SDS-) degrading capacity was found to be able to reduce molybdenum to the nontoxic molybdenum blue. The optimal pH, carbon source, molybdate concentration, and temperature supporting molybdate reduction were pH 7.0, glucose at 1.5% (w/v), between 25 and 30 mM, and 25°C, respectively. The optimum phosphate concentration for molybdate reduction was 5 mM. The Mo-blue produced exhibits an absorption spectrum with a maximum peak at 865 nm and a shoulder at 700 nm. None of the respiratory inhibitors tested showed any inhibition to the molybdenum-reducing activity suggesting that the electron transport system of this bacterium is not the site of molybdenum reduction. Chromium, cadmium, silver, copper, mercury, and lead caused approximately 77, 65, 77, 89, 80, and 80% inhibition of the molybdenum-reducing activity, respectively. Ferrous and stannous ions markedly increased the activity of molybdenum-reducing activity in this bacterium. The maximum tolerable concentration of SDS as a cocontaminant was 3 g/L. The characteristics of this bacterium make it a suitable candidate for molybdenum bioremediation of sites cocontaminated with detergent pollutant.
  8. Fulltext Kinetics of molybdenum reduction to molybdenum blue by Bacillus sp. strain A.rzi
    Othman AR, Bakar NA, Halmi MI, Johari WL, Ahmad SA, Jirangon H, et al.
    Biomed Res Int, 2013;2013:371058.
    PMID: 24369531 DOI: 10.1155/2013/371058
    Molybdenum is very toxic to agricultural animals. Mo-reducing bacterium can be used to immobilize soluble molybdenum to insoluble forms, reducing its toxicity in the process. In this work the isolation of a novel molybdate-reducing Gram positive bacterium tentatively identified as Bacillus sp. strain A.rzi from a metal-contaminated soil is reported. The cellular reduction of molybdate to molybdenum blue occurred optimally at 4 mM phosphate, using 1% (w/v) glucose, 50 mM molybdate, between 28 and 30 °C and at pH 7.3. The spectrum of the Mo-blue product showed a maximum peak at 865 nm and a shoulder at 700 nm. Inhibitors of bacterial electron transport system (ETS) such as rotenone, sodium azide, antimycin A, and potassium cyanide could not inhibit the molybdenum-reducing activity. At 0.1 mM, mercury, copper, cadmium, arsenic, lead, chromium, cobalt, and zinc showed strong inhibition on molybdate reduction by crude enzyme. The best model that fitted the experimental data well was Luong followed by Haldane and Monod. The calculated value for Luong's constants p max, K(s), S(m), and n was 5.88 μmole Mo-blue hr(-1), 70.36 mM, 108.22 mM, and 0.74, respectively. The characteristics of this bacterium make it an ideal tool for bioremediation of molybdenum pollution.
  9. Fulltext Molybdate reduction to molybdenum blue by an Antarctic bacterium
    Ahmad SA, Shukor MY, Shamaan NA, Mac Cormack WP, Syed MA
    Biomed Res Int, 2013;2013:871941.
    PMID: 24381945 DOI: 10.1155/2013/871941
    A molybdenum-reducing bacterium from Antarctica has been isolated. The bacterium converts sodium molybdate or Mo⁶⁺ to molybdenum blue (Mo-blue). Electron donors such as glucose, sucrose, fructose, and lactose supported molybdate reduction. Ammonium sulphate was the best nitrogen source for molybdate reduction. Optimal conditions for molybdate reduction were between 30 and 50 mM molybdate, between 15 and 20°C, and initial pH between 6.5 and 7.5. The Mo-blue produced had a unique absorption spectrum with a peak maximum at 865 nm and a shoulder at 710 nm. Respiratory inhibitors such as antimycin A, sodium azide, potassium cyanide, and rotenone failed to inhibit the reducing activity. The Mo-reducing enzyme was partially purified using ion exchange and gel filtration chromatography. The partially purified enzyme showed optimal pH and temperature for activity at 6.0 and 20°C, respectively. Metal ions such as cadmium, chromium, copper, silver, lead, and mercury caused more than 95% inhibition of the molybdenum-reducing activity at 0.1 mM. The isolate was tentatively identified as Pseudomonas sp. strain DRY1 based on partial 16s rDNA molecular phylogenetic assessment and the Biolog microbial identification system. The characteristics of this strain would make it very useful in bioremediation works in the polar and temperate countries.
  10. Characterization of surface electromyography using time domain features for determining hand motion and stages of contraction
    Bin Ahmad Nadzri AA, Ahmad SA, Marhaban MH, Jaafar H
    Australas Phys Eng Sci Med, 2014 Mar;37(1):133-7.
    PMID: 24443218 DOI: 10.1007/s13246-014-0243-3
    Surface electromyography (SEMG) signals can provide important information for prosthetic hand control application. In this study, time domain (TD) features were used in extracting information from the SEMG signal in determining hand motions and stages of contraction (start, middle and end). Data were collected from ten healthy subjects. Two muscles, which are flexor carpi ulnaris (FCU) and extensor carpi radialis (ECR) were assessed during three hand motions of wrist flexion (WF), wrist extension (WE) and co-contraction (CC). The SEMG signals were first segmented into 132.5 ms windows, full wave rectified and filtered with a 6 Hz low pass Butterworth filter. Five TD features of mean absolute value, variance, root mean square, integrated absolute value and waveform length were used for feature extraction and subsequently patterns were determined. It is concluded that the TD features that were used are able to differentiate hand motions. However, for the stages of contraction determination, although there were patterns observed, it is determined that the stages could not be properly be differentiated due to the variability of signal strengths between subjects.
  11. Fulltext A novel DNA nanosensor based on CdSe/ZnS quantum dots and synthesized Fe3O4 magnetic nanoparticles
    Hushiarian R, Yusof NA, Abdullah AH, Ahmad SA, Dutse SW
    Molecules, 2014 Apr 09;19(4):4355-68.
    PMID: 24722589 DOI: 10.3390/molecules19044355
    Although nanoparticle-enhanced biosensors have been extensively researched, few studies have systematically characterized the roles of nanoparticles in enhancing biosensor functionality. This paper describes a successful new method in which DNA binds directly to iron oxide nanoparticles for use in an optical biosensor. A wide variety of nanoparticles with different properties have found broad application in biosensors because their small physical size presents unique chemical, physical, and electronic properties that are different from those of bulk materials. Of all nanoparticles, magnetic nanoparticles are proving to be a versatile tool, an excellent case in point being in DNA bioassays, where magnetic nanoparticles are often used for optimization of the hybridization and separation of target DNA. A critical step in the successful construction of a DNA biosensor is the efficient attachment of biomolecules to the surface of magnetic nanoparticles. To date, most methods of synthesizing these nanoparticles have led to the formation of hydrophobic particles that require additional surface modifications. As a result, the surface to volume ratio decreases and nonspecific bindings may occur so that the sensitivity and efficiency of the device deteriorates. A new method of large-scale synthesis of iron oxide (Fe3O4) nanoparticles which results in the magnetite particles being in aqueous phase, was employed in this study. Small modifications were applied to design an optical DNA nanosensor based on sandwich hybridization. Characterization of the synthesized particles was carried out using a variety of techniques and CdSe/ZnS core-shell quantum dots were used as the reporter markers in a spectrofluorophotometer. We showed conclusively that DNA binds to the surface of ironoxide nanoparticles without further surface modifications and that these magnetic nanoparticles can be efficiently utilized as biomolecule carriers in biosensing devices.
  12. Ebola and compliance with infection prevention measures in Nigeria
    Yusuf I, Adam RU, Ahmad SA, Yee PL
    Lancet Infect Dis, 2014 Nov;14(11):1045-1046.
    PMID: 25282666 DOI: 10.1016/S1473-3099(14)70954-5
  13. Fulltext The assessment of cholinesterase from the liver of Puntius javanicus as detection of metal ions
    Sabullah MK, Sulaiman MR, Abd Shukor MY, Syed MA, Shamaan NA, Khalid A, et al.
    ScientificWorldJournal, 2014;2014:571094.
    PMID: 25401148 DOI: 10.1155/2014/571094
    Crude extract of ChE from the liver of Puntius javanicus was purified using procainamide-sepharyl 6B. S-Butyrylthiocholine iodide (BTC) was selected as the specific synthetic substrate for this assay with the highest maximal velocity and lowest biomolecular constant at 53.49 µmole/min/mg and 0.23 mM, respectively, with catalytic efficiency ratio of 0.23. The optimum parameter was obtained at pH 7.5 and optimal temperature in the range of 25 to 30°C. The effect of different storage condition was assessed where ChE activity was significantly decreased after 9 days of storage at room temperature. However, ChE activity showed no significant difference when stored at 4.0, 0, and -25°C for 15 days. Screening of heavy metals shows that chromium, copper, and mercury strongly inhibited P. javanicus ChE by lowering the activity below 50%, while several pairwise combination of metal ions exhibited synergistic inhibiting effects on the enzyme which is greater than single exposure especially chromium, copper, and mercury. The results showed that P. javanicus ChE has the potential to be used as a biosensor for the detection of metal ions.
  14. Fulltext Cognitive assessments for the early diagnosis of dementia after stroke
    Al-Qazzaz NK, Ali SH, Ahmad SA, Islam S
    Neuropsychiatr Dis Treat, 2014;10:1743-51.
    PMID: 25246795 DOI: 10.2147/NDT.S68443
    The early detection of poststroke dementia (PSD) is important for medical practitioners to customize patient treatment programs based on cognitive consequences and disease severity progression. The aim is to diagnose and detect brain degenerative disorders as early as possible to help stroke survivors obtain early treatment benefits before significant mental impairment occurs. Neuropsychological assessments are widely used to assess cognitive decline following a stroke diagnosis. This study reviews the function of the available neuropsychological assessments in the early detection of PSD, particularly vascular dementia (VaD). The review starts from cognitive impairment and dementia prevalence, followed by PSD types and the cognitive spectrum. Finally, the most usable neuropsychological assessments to detect VaD were identified. This study was performed through a PubMed and ScienceDirect database search spanning the last 10 years with the following keywords: "post-stroke"; "dementia"; "neuro-psychological"; and "assessments". This study focuses on assessing VaD patients on the basis of their stroke risk factors and cognitive function within the first 3 months after stroke onset. The search strategy yielded 535 articles. After application of inclusion and exclusion criteria, only five articles were considered. A manual search was performed and yielded 14 articles. Twelve articles were included in the study design and seven articles were associated with early dementia detection. This review may provide a means to identify the role of neuropsychological assessments as early PSD detection tests.
  15. Fulltext Antiartherosclerotic effects of plant flavonoids
    Salvamani S, Gunasekaran B, Shaharuddin NA, Ahmad SA, Shukor MY
    Biomed Res Int, 2014;2014:480258.
    PMID: 24971331 DOI: 10.1155/2014/480258
    Atherosclerosis is the process of hardening and narrowing the arteries. Atherosclerosis is generally associated with cardiovascular diseases such as strokes, heart attacks, and peripheral vascular diseases. Since the usage of the synthetic drug, statins, leads to various side effects, the plants flavonoids with antiartherosclerotic activity gained much attention and were proven to reduce the risk of atherosclerosis in vitro and in vivo based on different animal models. The flavonoids compounds also exhibit lipid lowering effects and anti-inflammatory and antiatherogenic properties. The future development of flavonoids-based drugs is believed to provide significant effects on atherosclerosis and its related diseases. This paper discusses the antiatherosclerotic effects of selected plant flavonoids such as quercetin, kaempferol, myricetin, rutin, naringenin, catechin, fisetin, and gossypetin.
  16. Fulltext Role of EEG as biomarker in the early detection and classification of dementia
    Al-Qazzaz NK, Ali SH, Ahmad SA, Chellappan K, Islam MS, Escudero J
    ScientificWorldJournal, 2014;2014:906038.
    PMID: 25093211 DOI: 10.1155/2014/906038
    The early detection and classification of dementia are important clinical support tasks for medical practitioners in customizing patient treatment programs to better manage the development and progression of these diseases. Efforts are being made to diagnose these neurodegenerative disorders in the early stages. Indeed, early diagnosis helps patients to obtain the maximum treatment benefit before significant mental decline occurs. The use of electroencephalogram as a tool for the detection of changes in brain activities and clinical diagnosis is becoming increasingly popular for its capabilities in quantifying changes in brain degeneration in dementia. This paper reviews the role of electroencephalogram as a biomarker based on signal processing to detect dementia in early stages and classify its severity. The review starts with a discussion of dementia types and cognitive spectrum followed by the presentation of the effective preprocessing denoising to eliminate possible artifacts. It continues with a description of feature extraction by using linear and nonlinear techniques, and it ends with a brief explanation of vast variety of separation techniques to classify EEG signals. This paper also provides an idea from the most popular studies that may help in diagnosing dementia in early stages and classifying through electroencephalogram signal processing and analysis.
  17. Fulltext Cognitive impairment and memory dysfunction after a stroke diagnosis: a post-stroke memory assessment
    Al-Qazzaz NK, Ali SH, Ahmad SA, Islam S, Mohamad K
    Neuropsychiatr Dis Treat, 2014;10:1677-91.
    PMID: 25228808 DOI: 10.2147/NDT.S67184
    Cognitive impairment and memory dysfunction following stroke diagnosis are common symptoms that significantly affect the survivors' quality of life. Stroke patients have a high potential to develop dementia within the first year of stroke onset. Currently, efforts are being exerted to assess stroke effects on the brain, particularly in the early stages. Numerous neuropsychological assessments are being used to evaluate and differentiate cognitive impairment and dementia following stroke. This article focuses on the role of available neuropsychological assessments in detection of dementia and memory loss after stroke. This review starts with stroke types and risk factors associated with dementia development, followed by a brief description of stroke diagnosis criteria and the effects of stroke on the brain that lead to cognitive impairment and end with memory loss. This review aims to combine available neuropsychological assessments to develop a post-stroke memory assessment (PSMA) scheme based on the most recognized and available studies. The proposed PSMA is expected to assess different types of memory functionalities that are related to different parts of the brain according to stroke location. An optimal therapeutic program that would help stroke patients enjoy additional years with higher quality of life is presented.
  18. Fulltext Optimization of milk-based medium for efficient cultivation of Bifidobacterium pseudocatenulatum G4 using face-centered central composite-response surface methodology
    Abdul Khalil K, Mustafa S, Mohammad R, Bin Ariff A, Shaari Y, Abdul Manap Y, et al.
    Biomed Res Int, 2014;2014:787989.
    PMID: 24527457 DOI: 10.1155/2014/787989
    This study was undertaken to optimize skim milk and yeast extract concentration as a cultivation medium for optimal Bifidobacteria pseudocatenulatum G4 (G4) biomass and β -galactosidase production as well as lactose and free amino nitrogen (FAN) balance after cultivation period. Optimization process in this study involved four steps: screening for significant factors using 2(3) full factorial design, steepest ascent, optimization using FCCD-RSM, and verification. From screening steps, skim milk and yeast extract showed significant influence on the biomass production and, based on the steepest ascent step, middle points of skim milk (6% wt/vol) and yeast extract (1.89% wt/vol) were obtained. A polynomial regression model in FCCD-RSM revealed that both factors were found significant and the strongest influence was given by skim milk concentration. Optimum concentrations of skim milk and yeast extract for maximum biomass G4 and β -galactosidase production meanwhile low in lactose and FAN balance after cultivation period were 5.89% (wt/vol) and 2.31% (wt/vol), respectively. The validation experiments showed that the predicted and experimental values are not significantly different, indicating that the FCCD-RSM model developed is sufficient to describe the cultivation process of G4 using skim-milk-based medium with the addition of yeast extract.
  19. A proposed aerobic granules size development scheme for aerobic granulation process
    Dahalan FA, Abdullah N, Yuzir A, Olsson G, Salmiati, Hamdzah M, et al.
    Bioresour Technol, 2015 Apr;181:291-6.
    PMID: 25661308 DOI: 10.1016/j.biortech.2015.01.062
    Aerobic granulation is increasingly used in wastewater treatment due to its unique physical properties and microbial functionalities. Granule size defines the physical properties of granules based on biomass accumulation. This study aims to determine the profile of size development under two physicochemical conditions. Two identical bioreactors namely Rnp and Rp were operated under non-phototrophic and phototrophic conditions, respectively. An illustrative scheme was developed to comprehend the mechanism of size development that delineates the granular size throughout the granulation. Observations on granules' size variation have shown that activated sludge revolutionised into the form of aerobic granules through the increase of biomass concentration in bioreactors which also determined the changes of granule size. Both reactors demonstrated that size transformed in a similar trend when tested with and without illumination. Thus, different types of aerobic granules may increase in size in the same way as recommended in the aerobic granule size development scheme.
  20. Fulltext Selection of Mother Wavelet Functions for Multi-Channel EEG Signal Analysis during a Working Memory Task
    Al-Qazzaz NK, Bin Mohd Ali SH, Ahmad SA, Islam MS, Escudero J
    Sensors (Basel), 2015;15(11):29015-35.
    PMID: 26593918 DOI: 10.3390/s151129015
    We performed a comparative study to select the efficient mother wavelet (MWT) basis functions that optimally represent the signal characteristics of the electrical activity of the human brain during a working memory (WM) task recorded through electro-encephalography (EEG). Nineteen EEG electrodes were placed on the scalp following the 10-20 system. These electrodes were then grouped into five recording regions corresponding to the scalp area of the cerebral cortex. Sixty-second WM task data were recorded from ten control subjects. Forty-five MWT basis functions from orthogonal families were investigated. These functions included Daubechies (db1-db20), Symlets (sym1-sym20), and Coiflets (coif1-coif5). Using ANOVA, we determined the MWT basis functions with the most significant differences in the ability of the five scalp regions to maximize their cross-correlation with the EEG signals. The best results were obtained using "sym9" across the five scalp regions. Therefore, the most compatible MWT with the EEG signals should be selected to achieve wavelet denoising, decomposition, reconstruction, and sub-band feature extraction. This study provides a reference of the selection of efficient MWT basis functions.
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links