Displaying publications 1 - 20 of 310 in total

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  1. Hajeb P, Jinap S, Shakibazadeh Sh, Afsah-Hejri L, Mohebbi GH, Zaidul IS
    PMID: 25090228 DOI: 10.1080/19440049.2014.942707
    This study aims to optimise the operating conditions for the supercritical fluid extraction (SFE) of toxic elements from fish oil. The SFE operating parameters of pressure, temperature, CO2 flow rate and extraction time were optimised using a central composite design (CCD) of response surface methodology (RSM). High coefficients of determination (R²) (0.897-0.988) for the predicted response surface models confirmed a satisfactory adjustment of the polynomial regression models with the operation conditions. The results showed that the linear and quadratic terms of pressure and temperature were the most significant (p < 0.05) variables affecting the overall responses. The optimum conditions for the simultaneous elimination of toxic elements comprised a pressure of 61 MPa, a temperature of 39.8ºC, a CO₂ flow rate of 3.7 ml min⁻¹ and an extraction time of 4 h. These optimised SFE conditions were able to produce fish oil with the contents of lead, cadmium, arsenic and mercury reduced by up to 98.3%, 96.1%, 94.9% and 93.7%, respectively. The fish oil extracted under the optimised SFE operating conditions was of good quality in terms of its fatty acid constituents.
    Matched MeSH terms: Models, Statistical
  2. Kamel NS, Sayeed S, Ellis GA
    IEEE Trans Pattern Anal Mach Intell, 2008 Jun;30(6):1109-13.
    PMID: 18421114 DOI: 10.1109/TPAMI.2008.32
    Utilizing the multiple degrees of freedom offered by the data glove for each finger and the hand, a novel on-line signature verification system using the Singular Value Decomposition (SVD) numerical tool for signature classification and verification is presented. The proposed technique is based on the Singular Value Decomposition in finding r singular vectors sensing the maximal energy of glove data matrix A, called principal subspace, so the effective dimensionality of A can be reduced. Having modeled the data glove signature through its r-principal subspace, signature authentication is performed by finding the angles between the different subspaces. A demonstration of the data glove is presented as an effective high-bandwidth data entry device for signature verification. This SVD-based signature verification technique is tested and its performance is shown to be able to recognize forgery signatures with a false acceptance rate of less than 1.2%.
    Matched MeSH terms: Models, Statistical
  3. Bawadikji AA, Teh CH, Sheikh Abdul Kader MAB, Abdul Wahab MJB, Syed Sulaiman SA, Ibrahim B
    Am J Cardiovasc Drugs, 2020 Apr;20(2):169-177.
    PMID: 31435902 DOI: 10.1007/s40256-019-00364-2
    BACKGROUND: Warfarin is prescribed as an oral anticoagulant to treat/prevent thromboembolism in conditions such as atrial fibrillation. As there is a narrow therapeutic window, treatment with warfarin is challenging. Pharmacometabonomics using nuclear magnetic resonance (NMR) spectroscopy may provide novel techniques for the identification of novel biomarkers of warfarin.

    PURPOSE: The aim was to determine the metabolic fingerprint that predicts warfarin response based on the international normalized ratio (INR) in patients who are already receiving warfarin (phase I: identification) and to ascertain the metabolic fingerprint that discriminates stable from unstable INR in patients starting treatment with warfarin (phase II: validation).

    EXPERIMENTAL APPROACH: A total of 94 blood samples were collected for phase I: 44 patients with stable INR and 50 with unstable INR. Meanwhile, 23 samples were collected for phase II: nine patients with stable INR and 14 with unstable INR. Data analysis was performed using multivariate analysis including principal component analysis and partial least square-discriminate analysis (PLS-DA), followed by univariate and multivariate logistic regression (MVLR) to develop a model to identify unstable INR biomarkers.

    KEY RESULTS: For phase I, the PLS-DA model showed the following results: sensitivity 93.18%, specificity 91.49% and accuracy 92.31%. In the MVLR analysis of phase I, ten regions were associated with unstable INR. For phase II, the PLS-DA model showed the following results: sensitivity 66.67%, specificity 61.54% and accuracy 63.64%.

    CONCLUSIONS AND IMPLICATIONS: We have shown that the pharmacometabonomics technique was able to differentiate between unstable and stable INR with good accuracy. NMR-based pharmacometabonomics has the potential to identify novel biomarkers in plasma, which can be useful in individualizing treatment and controlling warfarin side effects, thus, minimizing undesirable effects in the future.

    Matched MeSH terms: Models, Statistical
  4. Ghasemzadeh A, Jaafar HZ, Karimi E, Rahmat A
    PMID: 25169626 DOI: 10.1186/1472-6882-14-318
    Extraction prior to component analysis is the primary step in the recovery and isolation of bioactive phytochemicals from plant materials.
    Matched MeSH terms: Models, Statistical
  5. Law CW, Rampal S, Roslani AC, Mahadeva S
    J Gastroenterol Hepatol, 2014 Nov;29(11):1890-6.
    PMID: 24909623 DOI: 10.1111/jgh.12638
    With an increasing burden on overstretched colonoscopy services, a simple risk score for significant pathology in symptomatic patients may aid in the prioritization of patients.
    Matched MeSH terms: Models, Statistical
  6. Mellor D, Fuller-Tyszkiewicz M, McCabe MP, Ricciardelli LA, Skouteris H, Mussap AJ
    Ethn Health, 2014;19(5):548-64.
    PMID: 24261816 DOI: 10.1080/13557858.2013.857761
    OBJECTIVE: This study aimed to identify cultural-level variables that may influence the extent to which adolescents from different cultural groups are dissatisfied with their bodies.
    DESIGN: A sample of 1730 male and 2000 female adolescents from Australia, Fiji, Malaysia, Tonga, Tongans in New Zealand, China, Chile, and Greece completed measures of body satisfaction, and the sociocultural influences on body image and body change questionnaire, and self-reported height and weight. Country gross domestic product and national obesity were recorded using global databases.
    RESULTS: Prevalence of obesity/overweight and cultural endorsement of appearance standards explained variance in individual-level body dissatisfaction (BD) scores, even after controlling for the influence of individual differences in body mass index and internalization of appearance standards.
    CONCLUSIONS: Cultural-level variables may account for the development of adolescent BD.
    KEYWORDS: GDP; adolescents; body dissatisfaction; culture; sociocultural influences
    Matched MeSH terms: Models, Statistical
  7. Chew FN, Tan WS, Boo HC, Tey BT
    Prep Biochem Biotechnol, 2012;42(6):535-50.
    PMID: 23030465 DOI: 10.1080/10826068.2012.660903
    An optimized cultivation condition is needed to maximize the functional green fluorescent protein (GFP) production. Six process variables (agitation rate, temperature, initial medium pH, concentration of inducer, time of induction, and inoculum density) were screened using the fractional factorial design. Three variables (agitation rate, temperature, and time of induction) exerted significant effects on functional GFP production in E. coli shake flask cultivation and were optimized subsequently using the Box-Behnken design. An agitation rate of 206 rpm at 31°C and induction of the protein expression when the cell density (OD(600nm)) reaches 1.04 could enhance the yield of functional GFP production from 0.025 g/L to 0.241 g/L, which is about ninefold higher than the unoptimized conditions. Unoptimized cultivation conditions resulted in protein aggregation and hence reduced the quantity of functional GFP. The model and regression equation based on the shake flask cultivation could be applied to a 2-L bioreactor for maximum functional GFP production.
    Matched MeSH terms: Models, Statistical
  8. Mathieu C, Guillaume V, Sabine A, Ong KC, Wong KT, Legras-Lachuer C, et al.
    PLoS One, 2012;7(2):e32157.
    PMID: 22393386 DOI: 10.1371/journal.pone.0032157
    Nipah virus (NiV) is a recently emerged zoonotic Paramyxovirus that causes regular outbreaks in East Asia with mortality rate exceeding 75%. Major cellular targets of NiV infection are endothelial cells and neurons. To better understand virus-host interaction, we analyzed the transcriptome profile of NiV infection in primary human umbilical vein endothelial cells. We further assessed some of the obtained results by in vitro and in vivo methods in a hamster model and in brain samples from NiV-infected patients. We found that NiV infection strongly induces genes involved in interferon response in endothelial cells. Among the top ten upregulated genes, we identified the chemokine CXCL10 (interferon-induced protein 10, IP-10), an important chemoattractant involved in the generation of inflammatory immune response and neurotoxicity. In NiV-infected hamsters, which develop pathology similar to what is seen in humans, expression of CXCL10 mRNA was induced in different organs with kinetics that followed NiV replication. Finally, we showed intense staining for CXCL10 in the brain of patients who succumbed to lethal NiV infection during the outbreak in Malaysia, confirming induction of this chemokine in fatal human infections. This study sheds new light on NiV pathogenesis, indicating the role of CXCL10 during the course of infection and suggests that this chemokine may serve as a potential new marker for lethal NiV encephalitis.
    Matched MeSH terms: Models, Statistical
  9. Hua LT, Noland RB, Evans AW
    Accid Anal Prev, 2010 Nov;42(6):1934-42.
    PMID: 20728645 DOI: 10.1016/j.aap.2010.05.015
    Recent empirical research has found that there is an inverted U-shaped or Kuznets relationship between income and motor vehicle crash (MVC) deaths, such that MVC deaths increase as national income increases and decrease after reaching a critical level. Corruption has been identified as one of the underlying factors that could affect this relationship, primarily by undermining institutional development and effective enforcement schemes. The total effect of corruption can be decomposed into two components, a direct and an indirect effect. The direct effect measures the immediate impact of corruption on MVC deaths by undermining effective enforcement and regulations, while the indirect effect captures the impact of corruption on hindering increases in per capita income and the consequent impact of reduced income on MVC deaths. By influencing economic growth, corruption can lead to an increase or decrease in MVC deaths depending on the income level. Using data from 60 countries between 1982 and 2003, these effects are estimated using linear panel and fixed effects negative binomial models. The estimation results suggest that corruption has different direct effects for less developed and highly developed countries. It has a negative (decreasing) effect on MVC deaths for less developed countries and a positive (increasing) effect on MVC deaths for highly developed countries. For highly developed countries, the total effect is positive at lower per capita income levels, but decreases with per capita income and becomes negative at per capita income levels of about US$ 38,248. For less developed countries, the total effect is negative within the sample range and decreases with increased per capita income. In summary, the results of this study suggest that reduction of corruption is likely a necessary condition to effectively tackle road safety problems.
    Matched MeSH terms: Models, Statistical
  10. Aljunid S, Maimaiti N, Nur AM, Noor MRM, Wan Puteh SE
    BMC Public Health, 2016 Jan 23;16:71.
    PMID: 26803814 DOI: 10.1186/s12889-016-2754-1
    BACKGROUND: The HPV vaccine was introduced to Malaysian national immunization programme in 2010. The current implementation age of HPV vaccination in Malaysian is at the age of 13 years school girls, given according to a 3 doses protocol which may complicate implementation and compliance. Aim of the study is to determine the cost-effectiveness of HPV vaccination regime comparing twice versus thrice HPV vaccinations dose regime among adolescent girls in Malaysia.

    METHODS: A Markov cohort model reflecting the natural history of HPV infection accounting for oncogenic and low-risk HPV was adapted for 13 year old Malaysian girls cohort (n = 274,050). Transition probabilities, utilities values, epidemiological and cost data were sourced from published literature and local data. Vaccine effectiveness was based on overall efficacy reported from 3-doses clinical trials, with the assumption that the 2-doses is non-inferior to the 3-doses allowing overall efficacy to be inferred from the 3-doses immunogenicity data. Price parity and life-long protection were assumed. The payer perspective was adopted, with appropriate discounting for costs (3 %) and outcomes (3 %). One way sensitivity analysis was conducted. The sensitivity analysis on cost of vaccine, vaccine coverage and discount rate with a 2-doses protocol was performed.

    RESULT: The 3-doses and 2-doses regimes showed same number of Cervical Cancers averted (361 cases); QALYs saved at 7,732,266. However, the lifetime protection under the 2-doses regime, showed a significant cost-savings of RM 36, 722,700 compared to the 3-doses scheme. The MOH Malaysia could vaccinate 137,025 more girls in this country using saving 2-doses regime vaccination programme. The model predicted that 2-doses HPV vaccination schemes can avoid additional 180 Cervical Cancers and 63 deaths compare to 3-doses.

    CONCLUSION: A 2-doses HPV vaccination scheme may enable Malaysian women to be protected at a lower cost than that achievable under a 3-doses scheme, while avoiding the same number of Cervical Cancer cases and deaths. Using the saving money with 2-doses, more Cervical Cancers and deaths can be avoided.

    Matched MeSH terms: Models, Statistical
  11. Zelenev A, Li J, Mazhnaya A, Basu S, Altice FL
    Lancet Infect Dis, 2018 02;18(2):215-224.
    PMID: 29153265 DOI: 10.1016/S1473-3099(17)30676-X
    BACKGROUND: Chronic infections with hepatitis C virus (HCV) and HIV are highly prevalent in the USA and concentrated in people who inject drugs. Treatment as prevention with highly effective new direct-acting antivirals is a prospective HCV elimination strategy. We used network-based modelling to analyse the effect of this strategy in HCV-infected people who inject drugs in a US city.

    METHODS: Five graph models were fit using data from 1574 people who inject drugs in Hartford, CT, USA. We used a degree-corrected stochastic block model, based on goodness-of-fit, to model networks of injection drug users. We simulated transmission of HCV and HIV through this network with varying levels of HCV treatment coverage (0%, 3%, 6%, 12%, or 24%) and varying baseline HCV prevalence in people who inject drugs (30%, 60%, 75%, or 85%). We compared the effectiveness of seven treatment-as-prevention strategies on reducing HCV prevalence over 10 years and 20 years versus no treatment. The strategies consisted of treatment assigned to either a randomly chosen individual who injects drugs or to an individual with the highest number of injection partners. Additional strategies explored the effects of treating either none, half, or all of the injection partners of the selected individual, as well as a strategy based on respondent-driven recruitment into treatment.

    FINDINGS: Our model estimates show that at the highest baseline HCV prevalence in people who inject drugs (85%), expansion of treatment coverage does not substantially reduce HCV prevalence for any treatment-as-prevention strategy. However, when baseline HCV prevalence is 60% or lower, treating more than 120 (12%) individuals per 1000 people who inject drugs per year would probably eliminate HCV within 10 years. On average, assigning treatment randomly to individuals who inject drugs is better than targeting individuals with the most injection partners. Treatment-as-prevention strategies that treat additional network members are among the best performing strategies and can enhance less effective strategies that target the degree (ie, the highest number of injection partners) within the network.

    INTERPRETATION: Successful HCV treatment as prevention should incorporate the baseline HCV prevalence and will achieve the greatest benefit when coverage is sufficiently expanded.

    FUNDING: National Institute on Drug Abuse.

    Matched MeSH terms: Models, Statistical
  12. Ehrmann C, Reinhardt JD, Joseph C, Hasnan N, Perrouin-Verbe B, Tederko P, et al.
    Arch Phys Med Rehabil, 2020 12;101(12):2112-2143.
    PMID: 32980339 DOI: 10.1016/j.apmr.2020.09.374
    OBJECTIVE: To provide prevalence estimates for problems in functioning of community-dwelling persons with spinal cord injury (SCI) and to examine associations between various areas of functioning with the purpose of supporting countries in identifying targets for interventions.

    DESIGN: Cross-sectional survey.

    SETTING: Community, 22 countries including all World Health Organization regions.

    PARTICIPANTS: Persons (N=12,591) with traumatic or nontraumatic SCI aged 18 years or older.

    INTERVENTIONS: Not applicable.

    MAIN OUTCOME MEASURES: We estimated the prevalence of problems in 53 areas of functioning from the Brief International Classification of Functioning, Disability and Health (ICF) core set for SCI, long-term context, or ICF rehabilitation set covering 4 domains: impairments in body functions, impairments in mental functions, independence in performing activities, and restrictions in participation. Associations between areas of functioning were identified and visualized using conditional independence graphs.

    RESULTS: Participants had a median age of 52 years, 73% were male, and 63% had paraplegia. Feeling tired, bowel dysfunction, sexual functions, spasticity, pain, carrying out daily routine, doing housework, getting up off the floor from lying on the back, pushing open a heavy door, and standing unsupported had the highest prevalence of problems (>70%). Clustering of associations within the 4 functioning domains was found, with the highest numbers of associations within impairments in mental functions. For the whole International Spinal Cord Injury sample, areas with the highest numbers of associations were circulatory problems, transferring bed-wheelchair, and toileting, while for the World Health Organization European and Western Pacific regions, these were dressing upper body, transferring bed-wheelchair, handling stress, feeling downhearted and depressed, and feeling happy.

    CONCLUSIONS: In each domain of functioning, high prevalence of problems and high connectivity of areas of functioning were identified. The understanding of problems and the identification of potential targets for intervention can inform decision makers at all levels of the health system aiming to improve the situation of people living with SCI.

    Matched MeSH terms: Models, Statistical
  13. Aris IM, Bernard JY, Chen LW, Tint MT, Pang WW, Lim WY, et al.
    Int J Epidemiol, 2017 04 01;46(2):513-525.
    PMID: 27649801 DOI: 10.1093/ije/dyw232
    Background: : Infant body mass index (BMI) peak has received much interest recently as a potential predictor of future obesity and metabolic risk. No studies, however, have examined infant BMI peak in Asian populations, in whom the risk of metabolic disease is higher.

    Methods: : We utilized data among 1020 infants from a mother-offspring cohort, who were Singapore citizens or permanent residents of Chinese, Malay or Indian ethnicity with homogeneous parental ethnic backgrounds, and did not receive chemotherapy, psychotropic drugs or have diabetes mellitus. Ethnicity was self-reported at recruitment and later confirmed using genotype analysis. Subject-specific BMI curves were fitted to infant BMI data using natural cubic splines with random coefficients to account for repeated measures in each child. We estimated characteristics of the child's BMI peak [age and magnitude at peak, average pre-peak velocity (aPPV)]. Systolic (SBP) and diastolic blood pressure (DBP), BMI, sum of skinfolds (SSF) and fat-mass index (FMI) were measured during a follow-up visit at age 48 months. Weighted multivariable linear regression was used to assess the predictors (maternal BMI, gestational weight gain, ethnicity, infant sex, gestational age, birthweight-for-gestational age and breastfeeding duration) of infant BMI peak and its associations with outcomes at 48 months. Comparisons between ethnicities were tested using Bonferroni post-hoc correction.

    Results: : Of 1020 infants, 80.5% were followed up at the 48-month visit. Mean (SD) BMI, SSF and FMI at 48 months were 15.6 (1.8) kg/m 2 , 16.5 (5.3) mm and 3.8 (1.3) kg/m 2 , respectively. Mean (SD) age at peak BMI was 6.0 (1.6) months, with a magnitude of 17.2 (1.4) kg/m 2 and pre-peak velocity of 0.7 (0.3) kg/m 2 /month. Compared with Chinese infants, the peak occurred later in Malay {B [95% confidence interval (CI): 0.64 mo (0.36, 0.92)]} and Indian infants [1.11 mo (0.76, 1.46)] and was lower in magnitude in Indian infants [-0.45 kg/m 2 (-0.69, -0.20)]. Adjusting for maternal education, BMI, gestational weight gain, ethnicity, infant sex, gestational age, birthweight-for-gestational-age and breastfeeding duration, higher peak and aPPV were associated with greater BMI, SSF and FMI at 48 months. Age at peak was positively associated with BMI at 48 months [0.15 units (0.09, 0.22)], whereas peak magnitude was associated with SBP [0.17 units (0.05, 0.30)] and DBP at 48 months [0.10 units (0.01, 0.22)]. Older age and higher magnitude at peak were associated with increased risk of overweight at 48 months [Relative Risk (95% CI): 1.35 (1.12-1.62) for age; 1.89 (1.60-2.24) for magnitude]. The associations of BMI peak with BMI and SSF at 48 months were stronger in Malay and Indian children than in Chinese children.

    Conclusions: : Ethnic-specific differences in BMI peak characteristics, and associations of BMI peak with early childhood cardio-metabolic markers, suggest an important impact of early BMI development on later metabolic outcomes in Asian populations.

    Matched MeSH terms: Models, Statistical
  14. Endarti D, Riewpaiboon A, Thavorncharoensap M, Praditsitthikorn N, Hutubessy R, Kristina SA
    Value Health Reg Issues, 2018 May;15:50-55.
    PMID: 29474178 DOI: 10.1016/j.vhri.2017.07.008
    OBJECTIVES: To gain insight into the most suitable foreign value set among Malaysian, Singaporean, Thai, and UK value sets for calculating the EuroQol five-dimensional questionnaire index score (utility) among patients with cervical cancer in Indonesia.

    METHODS: Data from 87 patients with cervical cancer recruited from a referral hospital in Yogyakarta province, Indonesia, from an earlier study of health-related quality of life were used in this study. The differences among the utility scores derived from the four value sets were determined using the Friedman test. Performance of the psychometric properties of the four value sets versus visual analogue scale (VAS) was assessed. Intraclass correlation coefficients and Bland-Altman plots were used to test the agreement among the utility scores. Spearman ρ correlation coefficients were used to assess convergent validity between utility scores and patients' sociodemographic and clinical characteristics. With respect to known-group validity, the Kruskal-Wallis test was used to examine the differences in utility according to the stages of cancer.

    RESULTS: There was significant difference among utility scores derived from the four value sets, among which the Malaysian value set yielded higher utility than the other three value sets. Utility obtained from the Malaysian value set had more agreements with VAS than the other value sets versus VAS (intraclass correlation coefficients and Bland-Altman plot tests results). As for the validity, the four value sets showed equivalent psychometric properties as those that resulted from convergent and known-group validity tests.

    CONCLUSIONS: In the absence of an Indonesian value set, the Malaysian value set was more preferable to be used compared with the other value sets. Further studies on the development of an Indonesian value set need to be conducted.

    Matched MeSH terms: Models, Statistical
  15. Khairudin N, Basri M, Fard Masoumi HR, Samson S, Ashari SE
    Molecules, 2018 Feb 13;23(2).
    PMID: 29438284 DOI: 10.3390/molecules23020397
    Azelaic acid (AzA) and its derivatives have been known to be effective in the treatment of acne and various cutaneous hyperpigmentary disorders. The esterification of azelaic acid with lauryl alcohol (LA) to produce dilaurylazelate using immobilized lipase B from Candida antarctica (Novozym 435) is reported. Response surface methodology was selected to optimize the reaction conditions. A well-fitting quadratic polynomial regression model for the acid conversion was established with regards to several parameters, including reaction time and temperature, enzyme amount, and substrate molar ratios. The regression equation obtained by the central composite design of RSM predicted that the optimal reaction conditions included a reaction time of 360 min, 0.14 g of enzyme, a reaction temperature of 46 °C, and a molar ratio of substrates of 1:4.1. The results from the model were in good agreement with the experimental data and were within the experimental range (R² of 0.9732).The inhibition zone can be seen at dilaurylazelate ester with diameter 9.0±0.1 mm activities against Staphylococcus epidermidis S273. The normal fibroblasts cell line (3T3) was used to assess the cytotoxicity activity of AzA and AzA derivative, which is dilaurylazelate ester. The comparison of the IC50 (50% inhibition of cell viability) value for AzA and AzA derivative was demonstrated. The IC50 value for AzA was 85.28 μg/mL, whereas the IC50 value for AzA derivative was more than 100 μg/mL. The 3T3 cell was still able to survive without any sign of toxicity from the AzA derivative; thus, it was proven to be non-toxic in this MTT assay when compared with AzA.
    Matched MeSH terms: Models, Statistical
  16. Karami A, Keiter S, Hollert H, Courtenay SC
    Environ Sci Pollut Res Int, 2013 Mar;20(3):1586-95.
    PMID: 22752811 DOI: 10.1007/s11356-012-1027-5
    This study represents a first attempt at applying a fuzzy inference system (FIS) and an adaptive neuro-fuzzy inference system (ANFIS) to the field of aquatic biomonitoring for classification of the dosage and time of benzo[a]pyrene (BaP) injection through selected biomarkers in African catfish (Clarias gariepinus). Fish were injected either intramuscularly (i.m.) or intraperitoneally (i.p.) with BaP. Hepatic glutathione S-transferase (GST) activities, relative visceral fat weights (LSI), and four biliary fluorescent aromatic compounds (FACs) concentrations were used as the inputs in the modeling study. Contradictory rules in FIS and ANFIS models appeared after conversion of bioassay results into human language (rule-based system). A "data trimming" approach was proposed to eliminate the conflicts prior to fuzzification. However, the model produced was relevant only to relatively low exposures to BaP, especially through the i.m. route of exposure. Furthermore, sensitivity analysis was unable to raise the classification rate to an acceptable level. In conclusion, FIS and ANFIS models have limited applications in the field of fish biomarker studies.
    Matched MeSH terms: Models, Statistical
  17. Hussain H, Yusoff MK, Ramli MF, Abd Latif P, Juahir H, Zawawi MA
    Pak J Biol Sci, 2013 Nov 15;16(22):1524-30.
    PMID: 24511695
    Nitrate-nitrogen leaching from agricultural areas is a major cause for groundwater pollution. Polluted groundwater with high levels of nitrate is hazardous and cause adverse health effects. Human consumption of water with elevated levels of NO3-N has been linked to the infant disorder methemoglobinemia and also to non-Hodgkin's disease lymphoma in adults. This research aims to study the temporal patterns and source apportionment of nitrate-nitrogen leaching in a paddy soil at Ladang Merdeka Ismail Mulong in Kelantan, Malaysia. The complex data matrix (128 x 16) of nitrate-nitrogen parameters was subjected to multivariate analysis mainly Principal Component Analysis (PCA) and Discriminant Analysis (DA). PCA extracted four principal components from this data set which explained 86.4% of the total variance. The most important contributors were soil physical properties confirmed using Alyuda Forecaster software (R2 = 0.98). Discriminant analysis was used to evaluate the temporal variation in soil nitrate-nitrogen on leaching process. Discriminant analysis gave four parameters (hydraulic head, evapotranspiration, rainfall and temperature) contributing more than 98% correct assignments in temporal analysis. DA allowed reduction in dimensionality of the large data set which defines the four operating parameters most efficient and economical to be monitored for temporal variations. This knowledge is important so as to protect the precious groundwater from contamination with nitrate.
    Matched MeSH terms: Models, Statistical
  18. Molanorouzi K, Khoo S, Morris T
    BMC Public Health, 2014;14:909.
    PMID: 25182130 DOI: 10.1186/1471-2458-14-909
    Although there is abundant evidence to recommend a physically active lifestyle, adult physical activity (PA) levels have declined over the past two decades. In order to understand why this happens, numerous studies have been conducted to uncover the reasons for people's participation in PA. Often, the measures used were not broad enough to reflect all the reasons for participation in PA. The Physical Activity and Leisure Motivation Scale (PALMS) was created to be a comprehensive tool measuring motives for participating in PA. This 40-item scale related to participation in sport and PA is designed for adolescents and adults. Five items constitute each of the eight sub-scales (mastery, enjoyment, psychological condition, physical condition, appearance, other's expectations, affiliation, competition/ego) reflecting motives for participation in PA that can be categorized as features of intrinsic and extrinsic motivation based on self-determination theory. The aim of the current study was to validate the PALMS in the cultural context of Malaysia, including to assess how well the PALMS captures the same information as the Recreational Exercise Motivation Measure (REMM).
    Matched MeSH terms: Models, Statistical
  19. Yin LK, Rajeswari M
    Biomed Mater Eng, 2014;24(6):3333-41.
    PMID: 25227043 DOI: 10.3233/BME-141156
    To segment an image using the random walks algorithm; users are often required to initialize the approximate locations of the objects and background in the image. Due to its segmenting model that is mainly reflected by the relationship among the neighborhood pixels and its boundary conditions, random walks algorithm has made itself sensitive to the inputs of the seeds. Instead of considering the relationship between the neighborhood pixels solely, an attempt has been made to modify the weighting function that accounts for the intensity changes between the neighborhood nodes. Local affiliation within the defined neighborhood region of the two nodes is taken into consideration by incorporating an extra penalty term into the weighting function. Besides that, to better segment images, particularly medical images with texture features, GLCM variance is incorporated into the weighting function through kernel density estimation (KDE). The probability density of each pixel belonging to the initialized seeds is estimated and integrated into the weighting function. To test the performance of the proposed weighting model, several medical images that mainly made up of 174-brain tumor images are experimented. These experiments establish that the proposed method produces better segmentation results than the original random walks.
    Matched MeSH terms: Models, Statistical
  20. Khandaker MU, Jojo PJ, Kassim HA, Amin YM
    Radiat Prot Dosimetry, 2012 Nov;152(1-3):33-7.
    PMID: 22887119 DOI: 10.1093/rpd/ncs145
    Concentrations of primordial radionuclides in common construction materials collected from the south-west coastal region of India were determined using a high-purity germanium gamma-ray spectrometer. Average specific activities (Bq kg(-1)) for (238)U((226)Ra) in cement, brick, soil and stone samples were obtained as 54 ± 13, 21 ± 4, 50 ± 12 and 46 ± 8, respectively. Respective values of (232)Th were obtained as 65 ± 10, 21 ± 3, 58 ± 10 and 57 ± 12. Concentrations of (40)K radionuclide in cement, brick, soil and stone samples were found to be 440 ± 91, 290 ± 20, 380 ± 61 and 432 ± 64, respectively. To evaluate the radiological hazards, radium equivalent activity, various hazard indices, absorbed dose rate and annual effective dose have been calculated, and compared with the literature values. Obtained data could be used as reference information to assess any radiological contamination due to construction materials in future.
    Matched MeSH terms: Models, Statistical
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