527 research outputs found

    A population-based study on the prevalence and factors associated with obesity in Selangor

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    Objective: This study was conducted to determine prevalence and factors associated with obesity in Selangor, Malaysia. Methods: A population-based cross-sectional study was conducted in all districts of Selangor State. All individuals, 15 years and above in the selected households, were included. A pre-tested structured questionnaire was used to collect the data. Weight was recorded using TANITA model HD-309 and height was measured using SECA Body meter Model 208. Statistical analysis was performed using Stata 8.2 taking into account the complex survey design. Results: The overall mean age of the 2219 respondents was 36.6(95% CI 35.7 – 37.6) years. There was no significant difference in the mean age of the males and females (p=0.697). The majority of the respondents were Malays (52.9%), followed by Chinese (30.9%), Indians (15.4%) and other races (0.9%). The overall mean BMI was 24.1 kg/m2 (95% CI=23.8- 24.4). The overall prevalence of obesity was 12.2% (95% CI 10.6%, 14.0%). There was no significant difference in the prevalence of obesity in the males compared to females (p>0.05). The prevalence of obesity increased with age up to the ages of 40-59 years and then decreased after 60 years. The highest prevalence of obesity was in the 40-59 years age groups in both sexes. The overall prevalence of obesity was significantly higher amongst the Malays (15.2%) compared to the Indians (11.6%) and Chinese (7.3%). Multivariate logistic regression analysis showed that only age and ethnicity were associated with obesity. Sex and educational level were not associated with obesity

    Major dietary patterns and their associations with socio-demographic characteristics and obesity among adolescents in Petaling District, Malaysia

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    Dietary pattern analysis has emerged as important instruments to identify modifiable dietary risk factors for non-communicable diseases. The aim of this study was to determine the major dietary patterns among adolescents in Petaling District, Selangor and their associations with socio-demographic characteristics and obesity. An analytic cross- sectional study design was conducted in selected secondary schools in Petaling District. Sampling with probability proportionate to size was used and five schools were selected. Self-administered semi-quantitative food frequency questionnaire was used for data collection. Weight was measured with a digital bathroom scale (TANITA model) and height was measured using SECA body meter. Principal component factor analysis using varimax orthogonal transformation was used to identify the dietary patterns. Chi square was used to test for associations of dietary patterns with socio-demographic characteristics and obesity. Three major dietary patterns were identified: firstly, fruits and vegetables; secondly, sugar and fat and finally, meat and chicken which explained for 12.7%, 11.6% and 10.7% variation in food intake, respectively. There were significant associations between ethnicity, religion, family income, educational level of parents and the dietary patterns. However, there was no significant association between obesity and the dietary patterns. It may be more effective to describe a healthy diet using results of dietary pattern analysis in public health intervention, rather than describing single food items or nutrients. It is recommended that nutrition education programmes should be implemented in schools so as to prevent the development of obesity in the non-obese

    Prevalence, awareness, treatment and control of hypertension in Malaysia: a national study of 16,440 subjects,”

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    Summary Study design: A cross-sectional study was conducted in all states of Malaysia to determine the prevalence, awareness, treatment and control of hypertension. A stratified two-stage cluster sampling design with proportional allocation was used. Methods: Trained nurses obtained two blood pressure measurements from each subject. Hypertension was defined as mean systolic blood pressure 4140 mmHg, diastolic blood pressure 490 mmHg, or a self-reported diagnosis of hypertension and taking antihypertensive medication. All data were analysed using Stata 9.2 software and took the complex survey design into account. A two-sided P-value of o0.05 was considered to be statistically significant. Results: The overall prevalence of hypertension for subjects aged X15 years was 27.8% (95% confidence interval (CI) 26.9-28.8). The prevalence of hypertension was significantly higher in males (29.6%, 95% CI 28.3-31.0) compared with females (26.0%, 95% CI 25.0-27.1). Multivariate logistic regression showed that the odds of having hypertension increased with increasing age, in males, in subjects with a family history of hypertension, with increasing body mass index, in non-smokers and with decreasing levels of education. Only 34.6% of the subjects with hypertension were aware of their hypertensive status, and 32.4 were taking antihypertensive medication. Amongst the latter group, only 26.8% had their blood pressure under control. The prevalence of hypertension amongst those aged X30 years has increased from 32.9% in 1996 to 40.5% in 2004. Conclusion: In Malaysia, the prevalence of hypertension is high, but levels of awareness, treatment and control are low. There is an urgent need for a ARTICLE IN PRES

    Towards improving short-term sea ice predictability using deformation observations

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    Short-term sea ice predictability is challenging despite recent advancements in sea ice modelling and new observations of sea ice deformation that capture small-scale features (open leads and ridges) at the kilometre scale. A new method for assimilation of satellite-derived sea ice deformation into numerical sea ice models is presented. Ice deformation provided by the Copernicus Marine Service is computed from sea ice drift derived from synthetic aperture radar at a high spatio-temporal resolution. We show that high values of ice deformation can be interpreted as reduced ice concentration or increased ice damage – i.e. scalar variables responsible for ice strength in brittle or visco-plastic sea ice dynamical models. This method is tested as a proof of concept with the neXt-generation Sea Ice Model (neXtSIM), where the assimilation scheme uses a data insertion approach and forecasting with one member. We obtain statistics of assimilation impact over a long test period with many realisations starting from different initial times. Assimilation and forecasting experiments are run on synthetic and real observations in January 2021 and show increased accuracy of deformation prediction for the first 3–4 d. Similar conclusions are obtained using both brittle and visco-plastic rheologies implemented in neXtSIM. Thus, the forecasts improve due to the update of sea ice mechanical properties rather than the exact rheological formulation. It is demonstrated that the assimilated information can be extrapolated in space – gaps in spatially discontinuous satellite observations of deformation are filled with a realistic pattern of ice cracks, confirmed by later satellite observations. The limitations and usefulness of the proposed assimilation approach are discussed in a context of ensemble forecasts. Pathways to estimate intrinsic predictability of sea ice deformation are proposed.</p

    Data assimilation using adaptive, non-conservative, moving mesh models

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    Numerical models solved on adaptive moving meshes have become increasingly prevalent in recent years. Motivating problems include the study of fluids in a Lagrangian frame and the presence of highly localized structures such as shock waves or interfaces. In the former case, Lagrangian solvers move the nodes of the mesh with the dynamical flow; in the latter, mesh resolution is increased in the proximity of the localized structure. Mesh adaptation can include remeshing, a procedure that adds or removes mesh nodes according to specific rules reflecting constraints in the numerical solver. In this case, the number of mesh nodes will change during the integration and, as a result, the dimension of the model's state vector will not be conserved. This work presents a novel approach to the formulation of ensemble data assimilation (DA) for models with this underlying computational structure. The challenge lies in the fact that remeshing entails a different state space dimension across members of the ensemble, thus impeding the usual computation of consistent ensemble-based statistics. Our methodology adds one forward and one backward mapping step before and after the ensemble Kalman filter (EnKF) analysis, respectively. This mapping takes all the ensemble members onto a fixed, uniform reference mesh where the EnKF analysis can be performed. We consider a high-resolution (HR) and a low-resolution (LR) fixed uniform reference mesh, whose resolutions are determined by the remeshing tolerances. This way the reference meshes embed the model numerical constraints and are also upper and lower uniform meshes bounding the resolutions of the individual ensemble meshes. Numerical experiments are carried out using 1-D prototypical models: Burgers and Kuramoto-Sivashinsky equations and both Eulerian and Lagrangian synthetic observations. While the HR strategy generally outperforms that of LR, their skill difference can be reduced substantially by an optimal tuning of the data assimilation parameters. The LR case is appealing in high dimensions because of its lower computational burden. Lagrangian observations are shown to be very effective in that fewer of them are able to keep the analysis error at a level comparable to the more numerous observers for the Eulerian case. This study is motivated by the development of suitable EnKF strategies for 2-D models of the sea ice that are numerically solved on a Lagrangian mesh with remeshing

    Diagnosis delay of breast cancer and its associated factors in Malaysian women

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    <p>Abstract</p> <p>Background</p> <p>Breast cancer is the leading cause of cancer mortality among women in Malaysia. Delayed diagnosis is preventable and has major effects on patients' prognosis and survival. The objectives of our study were to identify the magnitude of delayed diagnosis and its associated factors in women with breast cancer in Malaysia.</p> <p>Methods</p> <p>This study had a cross-sectional design. Respondents had histologically confirmed breast cancer and were registered at five medical centres between 2005 and 2007. All breast cancer patients who attended hospital clinics at the East Coast were included. Patients at Kuala Lumpur hospitals were selected by systematic sampling. A standardised questionnaire was developed to interview respondents. We measured the time from the first recognition of symptoms to the first general practitioners' consultation and to the histological diagnosis of breast cancer. Diagnosis delay was defined when there was more than 6 months from the recognition of symptoms to the histological diagnosis. Multiple logistic regression was used for analysis.</p> <p>Results</p> <p>In total, 328 respondents were included. The mean (standard deviation) age was 47.9 (9.4) years. Most respondents were of Malay ethnicity, were married housewives with a median family income of RM1500 a month. Most respondents had ductal carcinoma (89.3%) and the stage distribution was as follows: 5.2% stage I, 38.7% stage II, 44.8% stage III and 11.3% stage IV. The median time to consultation was 2 months and the median time to diagnosis was 5.5 months. The frequency of diagnosis delay of more than 3 months was 72.6% and delay of more than 6 months occurred in 45.5% of the cases. The factors associated with diagnosis delay included the use of alternative therapy (odds ratio (OR) 1.77; 95% confidence interval (CI): 1.06, 2.94), breast ulcer (OR 5.71; 95% CI: 1.59, 20.47), palpable axillary lymph nodes (OR 2.19; 95% CI: 1.23, 3.90), false-negative diagnostic test (OR 5.32; 95% CI: 2.32, 12.21), non-cancer interpretation (OR 1.68; 95% CI: 1.01, 2.78) and negative attitude toward treatment (OR 2.09; 95% CI: 1.15, 3.82).</p> <p>Conclusions</p> <p>Delays in consultation and diagnosis are serious problems in Malaysia. Diagnosis delay was influenced by complex interactions between many factors. Breast awareness and education are required to promote early detection, diagnosis and treatment before the tumours enlarge and metastasis.</p

    Incomplete datasets obscure associations between traits affecting dispersal ability and geographic range size of reef fishes in the Tropical Eastern Pacific

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    Dispersal is thought to be an important process determining range size, especially for species in highly spatially structured habitats, such as tropical reef fishes. Despite intensive research efforts, there is conflicting evidence about the role of dispersal in determining range size. We hypothesize that traits related to dispersal drive range sizes, but that complete and comprehensive datasets are essential for detecting relationships between species' dispersal ability and range size. We investigate the roles of six traits affecting several stages of dispersal (adult mobility, spawning mode, pelagic larval duration (PLD), body size, aggregation behavior, and circadian activity), in explaining range size variation of reef fishes in the Tropical Eastern Pacific (TEP). All traits, except for PLD (148 species), had data for all 497 species in the region. Using a series of statistical models, we investigated which traits were associated with large range sizes, when analyzing all TEP species or only species with PLD data. Furthermore, using null models, we analyzed whether the PLD-subset is representative of the regional species pool. Several traits affecting dispersal ability were strongly associated with range size, although these relationships could not be detected when using the PLD-subset. Pelagic spawners (allowing for passive egg dispersal) had on average 56% larger range sizes than nonpelagic spawners. Species with medium or high adult mobility had on average a 25% or 33% larger range, respectively, than species with low mobility. Null models showed that the PLD-subset was nonrepresentative of the regional species pool, explaining why model outcomes using the PLD-subset differed from the ones based on the complete dataset. Our results show that in the TEP, traits affecting dispersal ability are important in explaining range size variation. Using a regionally complete dataset was crucial for detecting the theoretically expected, but so far empirically unresolved, relationship between dispersal and range size

    Low back pain and association with whole body vibration among military armoured vehicle drivers in Malaysia.

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    A cross sectional study was conducted among military armoured vehicle drivers in the two largest mechanized battalions with the objective to determine the prevalence of low back pain (LBP), and its association with whole body vibration (WBV) and other associated factors. A self-administered questionnaire and Human Vibration Meter were used in this study. A total of 159 respondents participated in this study and 102 (64.2%) of them were subjected to WBV measurement. One-hundred-and-seventeen respondents complained of LBP for the past 12 months giving a prevalence of 73.6%. The prevalence of LBP among tracked armoured vehicle drivers was higher (81.7%) as compared to wheeled armoured vehicle drivers (67.0%). The mean acceleration at Z-axis in tracked armoured vehicles (1.09 ± 0.26 ms-2) and wheeled armoured vehicles (0.33 ± 0.07 ms-2) were the dominant vibration directions. The mean estimated vibration dose value (eVDV) for eight-hour daily exposure at Z-axis (19.86 ± 4.72 ms-1.75) in tracked armoured vehicles showed the highest estimation. Based on the European Vibration Directive (2002), the mean eVDV at Z-axis in tracked armoured vehicles exceeded exposure action value (EAV) (> 9.1 ms-1.75), but did not exceed exposure limit value (ELV) (<21.0 ms-1.75). Logistic regression analysis revealed that only driving in forward bending sitting posture (OR=3.63, 95% CI 1.06-12.42) and WBV exposure at X-axis (OR=1.94, 95% CI 1.02-3.69) were significant risk factors to LBP. Preventive measures should be implemented to minimize risk of WBV and to improve ergonomic postures among drivers

    Estimating instantaneous sea-ice dynamics from space using the bi-static radar measurements of Earth Explorer 10 candidate Harmony

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    This article describes the observation techniques and suggests processing methods to estimate dynamical sea-ice parameters from data of the Earth Explorer 10 candidate Harmony. The two Harmony satellites will fly in a reconfigurable formation with Sentinel-1D. Both will be equipped with a multi-angle thermal infrared sensor and a passive radar receiver, which receives the reflected Sentinel-1D signals using two antennas. During the lifetime of the mission, two different formations will be flown. In the stereo formation, the Harmony satellites will fly approximately 300 km in front and behind Sentinel-1, which allows for the estimation of instantaneous sea-ice drift vectors. We demonstrate that the addition of instantaneous sea-ice drift estimates on top of the daily integrated values from feature tracking have benefits in terms of interpretation, sampling and resolution. The wide-swath instantaneous drift observations of Harmony also help to put high-temporal-resolution instantaneous buoy observations into a spatial context. Additionally, it allows for the extraction of deformation parameters, such as shear and divergence. As a result, Harmony's data will help to improve sea-ice statistics and parametrizations to constrain sea-ice models. In the cross-track interferometry (XTI) mode, Harmony's satellites will fly in close formation with an XTI baseline to be able to estimate surface elevations. This will allow for improved estimates of sea-ice volume and also enables the retrieval of full, two-dimensional swell-wave spectra in sea-ice-covered regions without any gaps. In stereo formation, the line-of-sight diversity allows the inference of swell properties in both directions using traditional velocity bunching approaches. In XTI mode, Harmony's phase differences are only sensitive to the ground-range direction swell. To fully recover two-dimensional swell-wave spectra, a synergy between XTI height spectra and intensity spectra is required. If selected, the Harmony mission will be launched in 2028

    Microbiome Heritability and Its Role in Adaptation of Hosts to Novel Resources

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    Microbiomes are involved in most vital processes, such as immune response, detoxification, and digestion and are thereby elementary to organismal functioning and ultimately the host’s fitness. In turn, the microbiome may be influenced by the host and by the host’s environment. To understand microbiome dynamics during the process of adaptation to new resources, we performed an evolutionary experiment with the two-spotted spider mite, Tetranychus urticae. We generated genetically depleted strains of the two-spotted spider mite and reared them on their ancestral host plant and two novel host plants for approximately 12 generations. The use of genetically depleted strains reduced the magnitude of genetic adaptation of the spider mite host to the new resource and, hence, allowed for better detection of signals of adaptation via the microbiome. During the course of adaptation, we tested spider mite performance (number of eggs laid and longevity) and characterized the bacterial component of its microbiome (16S rRNA gene sequencing) to determine: (1) whether the bacterial communities were shaped by mite ancestry or plant environment and (2) whether the spider mites’ performance and microbiome composition were related. We found that spider mite performance on the novel host plants was clearly correlated with microbiome composition. Because our results show that only little of the total variation in the microbiome can be explained by the properties of the host (spider mite) and the environment (plant species) we studied, we argue that the bacterial community within hosts could be valuable for understanding a species’ performance on multiple resources
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