Displaying publications 161 - 180 of 390 in total

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  1. Krupa BN, Mohd Ali MA, Zahedi E
    Physiol Meas, 2009 Aug;30(8):729-43.
    PMID: 19550027 DOI: 10.1088/0967-3334/30/8/001
    Cardiotocograph (CTG) is widely used in everyday clinical practice for fetal surveillance, where it is used to record fetal heart rate (FHR) and uterine activity (UA). These two biosignals can be used for antepartum and intrapartum fetal monitoring and are, in fact, nonlinear and non-stationary. CTG recordings are often corrupted by artifacts such as missing beats in FHR, high-frequency noise in FHR and UA signals. In this paper, an empirical mode decomposition (EMD) method is applied on CTG signals. A recursive algorithm is first utilized to eliminate missing beats. High-frequency noise is reduced using EMD followed by the partial reconstruction (PAR) method, where the noise order is identified by a statistical method. The obtained signal enhancement from the proposed method is validated by comparing the resulting traces with the output obtained by applying classical signal processing methods such as Butterworth low-pass filtering, linear interpolation and a moving average filter on 12 CTG signals. Three obstetricians evaluated all 12 sets of traces and rated the proposed method, on average, 3.8 out of 5 on a scale of 1(lowest) to 5 (highest).
    Matched MeSH terms: Linear Models
  2. Elbashir AA, Saad B, Ali AS, Saleh MI, Aboul-Enein HY
    Biomed Chromatogr, 2009 Mar;23(3):295-301.
    PMID: 18816453 DOI: 10.1002/bmc.1113
    A capillary electrophoretic (CE) method for the baseline separation of the enantiomers of primaquine diphosphate (PQ) and quinocide (QC) (a major contaminant) in pharmaceutical formulations is proposed. Both components were separated under the following conditions: 50 mm tris phosphate buffer (pH 3.0) containing 15 mm hydroxypropyl-gamma-cyclodextrin (HP-gamma-CD) as background electrolyte; applied voltage, 16 kV; capillary temperature, 25 degrees C; detection wavelength, 254 nm; hydrostatic injection, 10 s. The separations were conducted using a 35 cm length and 50 microm i.d. uncoated fused silica capillary column. Under the optimized conditions, the components were successfully separated in about 5 min. Intraday precision of migration time and corrected peak areas when expressed as relative standard deviation ranged from 0.17 to 0.45 and 2.60 to 3.94%, respectively, while the interday precision ranged from 2.59 to 4.20 and 3.15 to 4.21%, respectively. After the validation exercise, the proposed method was applied for the determination of QC impurity in PQ formulations.
    Matched MeSH terms: Linear Models
  3. Mirhosseini H, Tan CP, Hamid NS, Yusof S
    J Agric Food Chem, 2007 Sep 19;55(19):7659-66.
    PMID: 17708646
    The possible relationships between the main emulsion components (namely, Arabic gum, xanthan gum, and orange oil) and the physicochemical properties of orange beverage emulsion were evaluated by using response surface methodology. The physicochemical emulsion property variables considered as response variables were emulsion stability, viscosity, fluid behavior, zeta-potential, and electrophoretic mobility. The independent variables had the most and least significant ( p < 0.05) effect on viscosity and zeta-potential, respectively. The quadratic effect of orange oil and Arabic gum, the interaction effect of Arabic gum and xanthan gum, and the main effect of Arabic gum were the most significant ( p < 0.05) effects on turbidity loss rate, viscosity, viscosity ratio, and mobility, respectively. The main effect of Arabic gum was found to be significant ( p < 0.05) in all response variables except for turbidity loss rate. The nonlinear regression equations were significantly ( p < 0.05) fitted for all response variables with high R (2) values (>0.86), which had no indication of lack of fit. The results indicated that a combined level of 10.78% (w/w) Arabic gum, 0.56% (w/w) xanthan gum, and 15.27% (w/w) orange oil was predicted to provide the overall optimum region in terms of physicochemical properties studied. No significant ( p > 0.05) difference between the experimental and the predicted values confirmed the adequacy of response surface equations.
    Matched MeSH terms: Linear Models
  4. Loh LC, Teh PN, Seth KD, Raman S, Vijayasingham P, Thayaparan T
    Asia Pac J Public Health, 2006;18(1):49-55.
    PMID: 16629438 DOI: 10.1177/10105395060180010801
    In a multiracial country like Malaysia, ethnicity may influence the measurement of health-related quality of life (HRQL) in asthmatic patients. We invited 131 adult patients [44 Malays, 42 Chinese and 45 Indians; mean (95% CI) age: 43 (40.2-45.7) yrs; 28.2% male] with moderate-to-severe persistent asthma followed up in an urban-based hospital outpatient clinic to complete a disease-specific HRQL questionnaire [St Georges' Respiratory Questionnaire (SGRQ)] and to provide socio-demographic and asthma-related data. Indians reported significantly worse SGRQ total score, compared to Malays [mean (95% CI) difference: 10.15 (0.51-19.78); p = 0.037] and SGRQ activity score, compared to Malays [13.50 (1.95-25.05); p = 0.019] and Chinese [11.88 (0.19-25.05); p = 0.046]. Further analysis using multivariate linear regression showed that Indian ethnicity remained independently associated with SGRQ scores. Our finding highlights the relevance of ethnicity in assessing HRQL of asthmatic patients in a multiracial country such as Malaysia.

    Study site: chest clinic of an urban-based
    university teaching hospital
    Matched MeSH terms: Linear Models
  5. Huda BZ, Rusli BN, Naing L, Tengku MA, Winn T, Rampal KG
    Med J Malaysia, 2004 Jun;59(2):242-51.
    PMID: 15559176 MyJurnal
    Job dissatisfaction in doctors and teachers is known to have direct consequences on the quality of service and teaching for patients and students respectively. A cross-sectional study to assess dissatisfaction in lecturers of School of Medical Sciences, Universiti Sains Malaysia (USM) and Faculty of Medicine, Universiti Kebangsaan Malaysia (UKM) was undertaken between August 2001 and May 2002. The original English version of the Job Content Questionnaire (CQ) version 1.7 (revised 1997) by Robert Karasek was self-administered to 73 (response rate 58.4%) and 80 (response rate 41.7%) lecturers in the medical faculties of USM and UKM, respectively. The prevalence of job dissatisfaction in USM and UKM lecturers were 42.6% and 42.9%, respectively; the difference was not significant (p>0.05). Risk factors of job dissatisfaction in USM lecturers were decision authority (p<0.001) and psychological job demand (p<0.001). Significant risk factors of job dissatisfaction in UKM lecturers were skill discretion (p<0.01) and psychological job demand (p<0.001). We conclude that psychological job demand was a risk factor of job dissatisfaction in both USM and UKM lecturers; in USM, decision authority was protective, while in UKM, skill discretion was protective against job dissatisfaction.
    Matched MeSH terms: Linear Models
  6. Motorykin O, Matzke MM, Waters KM, Massey Simonich SL
    Environ Sci Technol, 2013 Apr 2;47(7):3410-6.
    PMID: 23472838 DOI: 10.1021/es305295d
    The objective of this research was to investigate the relationship between lung cancer mortality rates, carcinogenic polycyclic aromatic hydrocarbon (PAH) emissions, and smoking on a global scale, as well as for different socioeconomic country groups. The estimated lung cancer deaths per 100,000 people (ED100000) and age standardized lung cancer death rate per 100,000 people (ASDR100000) in 2004 were regressed on PAH emissions in benzo[a]pyrene equivalence (BaPeq), smoking prevalence, cigarette price, gross domestic product per capita, percentage of people with diabetes, and average body mass index using simple and multiple linear regression for 136 countries. Using stepwise multiple linear regression, a statistically significant positive linear relationship was found between loge(ED100000) and loge(BaPeq) emissions for high (p-value <0.01) and for the combination of upper-middle and high (p-value <0.05) socioeconomic country groups. A similar relationship was found between loge(ASDR100000) and loge(BaPeq) emissions for the combination of upper-middle and high (p-value <0.01) socioeconomic country groups. Conversely, for loge(ED100000) and loge(ASDR100000), smoking prevalence was the only significant independent variable in the low socioeconomic country group (p-value <0.001). These results suggest that reducing BaPeq emissions in the U.S., Canada, Australia, France, Germany, Brazil, South Africa, Poland, Mexico, and Malaysia could reduce ED100000, while reducing smoking prevalence in Democratic People's Republic of Korea, Nepal, Mongolia, Cambodia, and Bangladesh could significantly reduce the ED100000 and ASDR100000.
    Matched MeSH terms: Linear Models
  7. Ting CM, Samdin SB, Salleh ShH, Omar MH, Kamarulafizam I
    PMID: 23367426 DOI: 10.1109/EMBC.2012.6347491
    This paper applies an expectation-maximization (EM) based Kalman smoother (KS) approach for single-trial event-related potential (ERP) estimation. Existing studies assume a Markov diffusion process for the dynamics of ERP parameters which is recursively estimated by optimal filtering approaches such as Kalman filter (KF). However, these studies only consider estimation of ERP state parameters while the model parameters are pre-specified using manual tuning, which is time-consuming for practical usage besides giving suboptimal estimates. We extend the KF approach by adding EM based maximum likelihood estimation of the model parameters to obtain more accurate ERP estimates automatically. We also introduce different model variants by allowing flexibility in the covariance structure of model noises. Optimal model selection is performed based on Akaike Information Criterion (AIC). The method is applied to estimation of chirp-evoked auditory brainstem responses (ABRs) for detection of wave V critical for assessment of hearing loss. Results shows that use of more complex covariances are better estimating inter-trial variability.
    Matched MeSH terms: Linear Models
  8. Won H, Abdul Manaf Z, Mat Ludin AF, Shahar S
    Geriatr Gerontol Int, 2017 Apr;17(4):554-560.
    PMID: 27231255 DOI: 10.1111/ggi.12753
    AIM: Studies of the association between body composition, both body fat and body muscle, and cognitive function are rarely reported. The aim of the present study was to determine the association between a wide range of body composition measures with cognitive function in older adults.

    METHODS: A total of 2322 Malaysian older adults aged 60 years and older were recruited using multistage random sampling in a population-based cross-sectional study. Out of 2322 older adults recruited, 2309 (48% men) completed assessments on cognitive function and body composition. Cognitive functions were assessed using the Malay version of the Mini-Mental State Examination, the Bahasa Malaysia version of Montreal Cognitive Assessment, Digit Span Test, Digit Symbol Test and Rey Auditory Verbal Learning Test. Body composition included body mass index, mid-upper arm circumference, waist circumference, calf circumference, waist-to-hip ratio, percentage body fat and skeletal muscle mass.

    RESULTS: The association between body composition and cognitive functions was analyzed using multiple linear regression. After adjustment for age, education years, hypertension, hypercholesterolemia, diabetes mellitus, depression, smoking status and alcohol consumption, we found that calf circumference appeared as a significant predictor for all cognitive tests among both men and women (P 

    Matched MeSH terms: Linear Models
  9. Asadi-Shekari Z, Moeinaddini M, Sultan Z, Shah MZ, Hamzah A
    Traffic Inj Prev, 2016 08 17;17(6):650-5.
    PMID: 26890058 DOI: 10.1080/15389588.2015.1136739
    OBJECTIVE: A number of efforts have been conducted on travel behavior and transport fatalities at the neighborhood or street level, and they have identified different factors such as roadway characteristics, personal indicators, and design indicators related to transport safety. However, only a limited number of studies have considered the relationship between travel behavior indicators and the number of transport fatalities at the city level. Therefore, this study explores this relationship and how to fill the mentioned gap in current knowledge.

    METHOD: A generalized linear model (GLM) estimates the relationships between different travel mode indicators (e.g., length of motorway per inhabitants, number of motorcycles per inhabitant, percentage of daily trips on foot and by bicycle, percentage of daily trips by public transport) and the number of passenger transport fatalities. Because this city-level model is developed using data sets from different cities all over the world, the impacts of gross domestic product (GDP) are also included in the model.

    CONCLUSIONS: Overall, the results imply that the percentage of daily trips by public transport, the percentage of daily trips on foot and by bicycle, and the GDP per inhabitant have negative relationships with the number of passenger transport fatalities, whereas motorway length and the number of motorcycles have positive relationships with the number of passenger transport fatalities.

    Matched MeSH terms: Linear Models
  10. Safari MJ, Wong JH, Ng KH, Jong WL, Cutajar DL, Rosenfeld AB
    Med Phys, 2015 May;42(5):2550-8.
    PMID: 25979047 DOI: 10.1118/1.4918576
    The MOSkin is a MOSFET detector designed especially for skin dose measurements. This detector has been characterized for various factors affecting its response for megavoltage photon beams and has been used for patient dose measurements during radiotherapy procedures. However, the characteristics of this detector in kilovoltage photon beams and low dose ranges have not been studied. The purpose of this study was to characterize the MOSkin detector to determine its suitability for in vivo entrance skin dose measurements during interventional radiology procedures.
    Matched MeSH terms: Linear Models
  11. Mohd Yusof MY, Cauwels R, Deschepper E, Martens L
    J Forensic Leg Med, 2015 Aug;34:40-4.
    PMID: 26165657 DOI: 10.1016/j.jflm.2015.05.004
    The third molar development (TMD) has been widely utilized as one of the radiographic method for dental age estimation. By using the same radiograph of the same individual, third molar eruption (TME) information can be incorporated to the TMD regression model. This study aims to evaluate the performance of dental age estimation in individual method models and the combined model (TMD and TME) based on the classic regressions of multiple linear and principal component analysis. A sample of 705 digital panoramic radiographs of Malay sub-adults aged between 14.1 and 23.8 years was collected. The techniques described by Gleiser and Hunt (modified by Kohler) and Olze were employed to stage the TMD and TME, respectively. The data was divided to develop three respective models based on the two regressions of multiple linear and principal component analysis. The trained models were then validated on the test sample and the accuracy of age prediction was compared between each model. The coefficient of determination (R²) and root mean square error (RMSE) were calculated. In both genders, adjusted R² yielded an increment in the linear regressions of combined model as compared to the individual models. The overall decrease in RMSE was detected in combined model as compared to TMD (0.03-0.06) and TME (0.2-0.8). In principal component regression, low value of adjusted R(2) and high RMSE except in male were exhibited in combined model. Dental age estimation is better predicted using combined model in multiple linear regression models.
    Matched MeSH terms: Linear Models
  12. Neo KS, Goh KT, Sam CT
    PMID: 11127329
    A survey was conducted between 1995 and 1997 to assess the impact of introduction of unleaded petrol and other public health measures on the blood lead level of the population. The geometric mean blood lead level of 269 government employees as determined by graphite furnace atomic absorption spectroscopy, was 66.0 microg/l, much lower than that recorded before introduction of lead-free petrol. Using multiple regression analysis, factors significantly associated with blood lead levels were: exposure to traffic, age (>50 years) and active smoking. Passive smoking, exposure to recent paint work, consumption of alcohol and traditional medicine were found not to be significantly associated with the blood lead level.
    Matched MeSH terms: Linear Models
  13. Smith JD
    Math Biosci, 1998 Nov;153(2):151-61.
    PMID: 9825637
    The Gibbs canonical ensemble of statistical mechanics is used to describe the probability distribution of the age classes of mothers of new-borns in an age-structured population. The Malthusian parameter emerges as a Lagrange multiplier corresponding to a generation time constraint, while a new perturbation parameter appears as the Lagrange multiplier corresponding to a maternity constraint. Classical Lotka stability reduces to the unperturbed case of the more general canonical ensemble model. The model is used in a case study of the female (peninsular) Malaysian population of 1970. The Malthusian parameter and perturbation are calculated easily by linear regression. Use of the model identifies an anomaly in the population due to the effects of World War II.
    Matched MeSH terms: Linear Models
  14. Chattopadhyay A
    Demography, 1998 Aug;35(3):335-44.
    PMID: 9749325
    With data from the Malaysian Family Life Survey, I use a continuous-state hazards model to study the impact of migration on the dynamics of individuals' careers. I distinguish between the effects of family migration and solo migration by gender. The results show that migration alters the career trajectory primarily by accelerating the process of occupational mobility rather than by increasing the level of occupational attainment. Further, the effect of migration on careers varies by type of migration, especially for women. Male-female differences in the outcome of family migration, however, are visible only in transitions into and out of employment.
    Matched MeSH terms: Linear Models
  15. Ho TM, DeBruynne J, Ahamad M, Darussamin H
    Asian Pac J Allergy Immunol, 1997 Sep;15(3):123-6.
    PMID: 9438543
    The MAST CLA system was evaluated against skin prick test (SPT) for diagnosis of allergies to house dust mites (Dermatophagoides pteronyssinus, Dermatophagoides farinae) and cats. Forty three asthmatic children were examined by SPT and MAST CLA. Chi-square analysis indicated significant association between SPT and MAST CLA results for the house dust mites but not for cats. The sensitivities of MAST CLA for house dust mites and cats were 100 and 25% respectively; specificities were all less than 50%. The efficiency of MAST CLA for detection of allergy to the house dust mites was 88% and 44% for cats. A significant linear correlation was found between SPT wheal size and MAST CLA grade for D. farinae but not for D. pteronyssinus and cats. It is concluded that the MAST CLA allergy system can be used to supplement SPT for diagnosis of allergies to house dust mites but not to cats.
    Matched MeSH terms: Linear Models
  16. Singh R, Singh HJ, Sirisinghe RG
    PMID: 7855654
    Spirometry was performed on 1,485 male subjects ranging in age from 13 years to 78 years and comprising of all the main ethnic groups in Malaysia. They were divided into six age categories. Mean forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) were 3.45 +/- 0.02 and 3.10 +/- 0.02, respectively. Both FVC and FEV1 correlated negatively with age. Regression analysis revealed an age-related decline in FVC of 295 ml per decade of life. Multiple stepwise regression of the data for the prediction of an individual's FVC above the age of 20 years gave the equation FVC (1) = 0.0404 (height in cm)-0.0295 (age in years)-2.2892. Predicted FVC values derived from equations based on other populations were considerably higher than the observed mean in this study. This study therefore, reemphasises the need to be cautions when applying formulae derived from one population to another. Grossly erroneous conclusions may be reached unless predicted equations for lung-function tests for a given population group are derived from studies based upon the same population group.
    Matched MeSH terms: Linear Models
  17. Noorhassim I, Rampal KG
    Am J Otolaryngol, 1998 8 6;19(4):240-3.
    PMID: 9692632
    PURPOSE: To determine the combined effect of smoking and age on hearing impairment.

    MATERIALS AND METHODS: Pure tone audiometry test was conducted on 263 residents of a rural village who were not exposed to noise. The pack-years of smoking were computed from the subjects' smoking history. The association between pack-years and hearing impairment was assessed. The combined effect of smoking and age on hearing impairment was determined based on prevalence rate ratio.

    RESULTS: There was a statistically significant trend in the number of pack-years of smoking and age as risk factors for hearing impairment. The prevalence rates of hearing impairment for nonsmokers aged 40 years and younger, smokers aged 40 years and younger, nonsmokers older than 40 years of age, and smokers older than 40 years of age were 6.9%, 11.9%, 29.7%, and 51.3%, respectively. The prevalence rate ratio for nonsmokers aged 40 years and younger, smokers aged 40 years and younger, nonsmokers older than 40 years of age, and smokers older than 40 years of age (nonsmokers aged 40 years and younger as a reference group) was 1, 1.7, 4.3, and 7.5, respectively. The prevalence rate ratios showed a multiplicative effect of smoking and age on hearing impairment.

    CONCLUSION: Age and smoking are risk factors for hearing impairment. It is clear that smoking and age have multiplicative adverse effects on hearing impairment.

    Matched MeSH terms: Linear Models
  18. Norsayani MY, Noor Hassim I
    J Occup Health, 2003 May;45(3):172-8.
    PMID: 14646293
    Medical students face the threat of needle stick injury with the consequent risk of acquiring blood-borne infection by pathogens such as HIV, Hepatitis B and Hepatitis C while performing their clinical activities in the hospitals. A cross-sectional study was conducted among 417 final year medical students from Universiti Kebangsaan Malaysia (UKM), University Malaya (UM) and Universiti Putra Malaysia (UPM). The aims of the study were to determine the incidence of cases and episodes of needle stick injury among them in the past year. This study was also done to find out the factors that might be associated with the occurrence of this problem. The factors were sociodemographic factors, duration of exposure, level of knowledge of blood-borne diseases and Universal Precaution, perception of risk of blood-borne diseases and level of practice of Universal Precaution. The incidence of needle stick injury among medical students was 14.1% (59 cases). The total number of episodes of needle stick injury was 87 and the incidence of episodes among respondents was high i.e. 20.9%. The highest incidence of episodes of needle stick injury occurred in Obstetric & Gynaecology postings, followed by Medicine and Surgery. For clinical procedures, venepuncture had the highest incidence followed by setting up drips and giving parenteral injections. The results showed the students who had needle stick injury (cases) had lower scores in the practice of Universal Precautions than non-cases (p<0.05). There was a significant association between the level of practice of Universal Precautions and the number of episodes of needle stick injury, i.e. the higher the score for the practice of Universal Precautions, the lower the number of episodes (beta=-2.03 x 10(-2), p<0.05). This study showed that medical students are at risk of needle stick injury and blood-borne infections during their clinical activities while performing procedures on patients especially for those who were poor at practising Universal Precautions. Therefore some preventive measures should be taken by the management of the universities and medical students to avoid the occurrence of these problems.
    Matched MeSH terms: Linear Models
  19. Norliza Ahmad, Munn-Sann Lye, Zalilah Mohd Shariff, Firdaus Mukhtar, Lim Poh Ying
    MyJurnal
    Introduction: Childhood obesity is increasing in prevalence in Malaysia. Excess in dietary intake and inadequate physical activity contribute to the development of obesity among children. The objective of this study was to de-termine the association between eating behaviour and excess weight among primary school children in an urban community in Malaysia. Methods: This is a baseline data of a randomized control field trial of a family-based inter-vention to reduce adiposity in overweight and obese children. It involved five primary government schools in Bandar Baru Bangi, Selangor. The inclusion criteria include parent-child dyad; children aged 7 to 10 years with body mass index (BMI) z-score of +1 standard deviation or more. Parents completed the validated self-administered Children Eating Behaviour Questionnaire (CEBQ). This questionnaire assessed children’s eating behaviour that includes food responsiveness, enjoyment of food, emotional overeating, desire to drink, slowness in eating, satiety responsiveness, emotional undereating and food fussiness. The children’s weight and height were measured and the BMI z-score was calculated. The association between CEBQ subscales and obesity was assessed using multiple linear regression, adjusted for sex and family income. Results: One hundred and thirty-four parent-child dyads had participated in this study. The food responsiveness was found to be significant with excess weight (β = 0.094, 95% CI: 0.02-0.17, p= 0.014). Conclusion: The food responsiveness subscale was associated with excess weight. This eating behaviour need to be taken into consideration in the development and implementation of health campaign targeted at the re-duction of childhood obesity.
    Matched MeSH terms: Linear Models
  20. Fatimah Ahmad Fauzi, Nor Afiah Mohd Zulkefli, Anisah Baharom
    MyJurnal
    Introduction: Adolescent aggression has become a serious public health problem with the escalating juvenile cases and violence among secondary school students by inflicting harm to others. The objective of this study was to deter-mine the biopsychosocial predictors of adolescent aggression among Form Four students in Hulu Langat. Methods: Cross-sectional study was conducted by proportionate population sampling method among Form Four students from all public secondary schools in Hulu Langat. Pre-tested questionnaires distributed to measure students’ ag-gression, demographic (ethnicity, family income), biological (sex, head injury, nutritional deficiency, breakfast skip-ping), psychological (attitude towards aggression, normative beliefs to aggression, personality trait, and emotional intelligence), and social factors (family environment, single parent status, domestic violence, peer deviant affiliation, alcohol, smoking, and substance abuse). Data was analysed using multivariate analysis to determine the significant predictors. Results: 480 students from four randomly selected schools participated in the study with response rate of 96.5%. The median aggression score was low, which was 23.00 (IQR=12.00). From simple linear regression, 15 factors had significant relationship with adolescent aggression. The predictors of adolescent aggression were lower family income, Malay ethnicity, nutritional deficiency, attitude towards aggression, and peer deviant affiliation (F [8, 244] =15.980, p-value
    Matched MeSH terms: Linear Models
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