Modeling Mode Choice Behavior of Motorcyclists in Malaysia

In Malaysia, motorcycle use has grown in popularity in the past decades and this has resulted in increased casualties among motorcyclists. However, earlier studies focused primarily on motorcycle safety issues rather than identifying factors that influence motorcycle use and motorcyclists’ mode choice behavior. To overcome these problems, this study focused on the concept of exposure control measures such as an alternative to road transport as a countermeasure aimed at shifting motorcycle users to other safer modes in order to reduce the number of motorcycle road accidents. This study developed a model for motorcyclist mode choice behavior and potential mode shift from the motorcycle to other safer modes. A cross-sectional survey of mode choice among bus, car and motorcycle users in Selangor state, Malaysia was conducted. Selangor state was chosen for the study as it has the highest number of motorcycle crashes in Malaysia. A total of 810 randomly self-administered questionnaires were collected from the household surveys for each mode user over a period of 6 months. Among the data collected were the demographic details, such as income, age, gender, and educational level, trip characteristics, and travel behavior of each mode user. In order to assess the relative importance of demographic, socio-economic and service attributes that influence travelers’ mode choice behavior, discrete choice models were developed in the form of a binomial logit (when there are only two choices), and the multinomial logit (when there are more than two choices) For the motorcycle and bus model, the results suggested that travel time and travel cost are characteristics that determine why motorcycle use is the favored modal choice. The estimated coefficients for travel time and travel cost for the bus mode are negative, implying that an increase in travel time and travel cost for the bus mode is likely to increase the probability of a motorcyclist to continue choosing the motorcycle as the preferred mode of transport. In order to promote greater use of public transport services, the study examined the probability of motorcycle riders shifting to public transport based on a scenario of a reduction in bus travel time and travel cost. The results of the predicted mode share probability show that when the bus and motorcycle are equally fast, 38% would use the motorcycle and 62% the bus The motorcycle and car model examined the influence of future income and car ownership on model shift. The results of the model predict that when the income level of motorcyclists reaches RM 2500 (about US$700) per month, the probability of motorcycle use would drop from 80% to 57%. At the same time, the probability of car commuters would increase from 20% to 41%. According to a World Bank study, if the current rates of economic growth continue uninterrupted, per capita income for Malaysia is expected to reach RM 2000 by the year 2013. According to our 8th Malaysia plan, the per capita income growth target under Vision 2020 is expected to be RM 3166. Therefore, a 29% reduction in motorcycle use is expected to be achieved between years 2013-2020. Similar trends were found for household car ownership. The results showed that ownership of one car in the household would result in a 14% reduction in motorcycle use, while ownership of two cars would result in a 42% reduction in motorcycle use relative to car use. Therefore, the study suggests that improvements in motorcyclists’ income and car ownership would have the greatest impact in influencing the mode preference of motorcyclists, and result in a significant reduction in motorcycle use and a shift towards safer modes of transport

Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation

Statistical Process Control Analysis

This thesis is concerned with the investigation of the two key aspects of statistical process control. The first aspect is maintaining a stable process so that the pattern of variation of process out-put is not changing. In order to maintain a stable process, the study includes an examination of the state of control of the process. A traditional variable control charts, x and R charts and also the x control chart based on sample median and median control chart in conjunction with a chart for sample range were used for both normal and non-normal process. The second aspect depicts the process capability. Assuming that the processes have reached the state of statistical control, capability measurements were proceeded in this study for both normal and non-normal processes. A simulation studies are carried out to compare the performance of the traditional and the robust control chart. Likewise, the classical capability index is compared to two robust capability index. The results of the study indicate that the traditional and the robust control chart are equally good when no contamination in the data. However, the later performs better than the former in the presence of outliers in the data. Similarly, the traditional process capability index are almost as good as the robust capability index as proposed by Clement (1989) and John Kot (1993) in a well behaved data. Nevertheless, the robust capability index were found to be better compared to the traditional index when contamination occurs in the data. The study also carried out an investigation of properties of the three types of bootstrap confidence interval for estimating the process capability index (Cpk)' namely the standard, percentile and bias corrected and accelerated for two processes (normal and skewed). The average lengths displayed a consistent pattern where the longest intervals were the standard intervals, and with the shortest intervals being the percentile and bias corrected and accelerated intervals for both normal and highly skewed processes. The results of the study seem to be consistent for sample size n = 25 to n = 50

Apigenin increases cisplatin inhibitory effects on the telomerase activity of triple negative breast cancer cells

Inhibition of telomerase activity has emerged as a promising strategy to combat cancer cells, especially ones with no specific molecular targets such as triple negative breast cancer (TNBC). Cisplatin, a chemotherapeutic drug, is causing DNA damage while apigenin, a plant-derived antioxidant, induces apoptosis in various cancer cell types. Little is known about their combined ability to inhibit telomerase activity in TNBC cells. In the current study, the effect of cisplatin in combination with apigenin was investigated with regards to telomerase activity and expression of the telomerase catalytic subunit hTERT as well as Heat Shock Protein 90 (Hsp90) and p23 in two types of TNBC (MDA-MB-231; HCC1806) and one non-tumorigenic (MCF10A) epithelial cell line. The results showed that the combined treatment of cisplatin and apigenin significantly down-regulated telomerase activity. The inhibition of telomerase activity was accompanied by a down-regulation of hTERT, Hsp90 and p23 at transcriptional and translational level in both TNBC cells, as compared to control cells. The results of the current study suggest that apigenin and cisplatin synergistically inhibit telomerase activity by downregulating the enzyme’s catalytic subunit. However, the exact roles of Hsp90 and p23 in the regulation of telomerase activity requires further investigation as they seem to be TNBC subtype-specific. © 2018 Penerbit UTM Press. All rights reserved

Understanding the Impact of Perfluorinated Compounds on Cardiovascular Diseases and Their Risk Factors: A Meta-Analysis Study

Perfluorinated compounds (PFCs) are non-biodegradable synthetic chemical compounds that are widely used in manufacturing many household products. Many studies have reported the association between PFCs exposure with the risk of developing cardiovascular diseases (CVDs). However, those reports are still debatable, due to their findings. Thus, this review paper aimed to analyse the association of PFCs compound with CVDs and their risk factors in humans by systematic review and meta-analysis. Google Scholar, PubMed and ScienceDirect were searched for PFCs studies on CVDs and their risk from 2009 until present. The association of PFCs exposure with the prevalence of CVDs and their risk factors were assessed by calculating the quality criteria, odds ratios (ORs), and 95% confidence intervals (CIs). CVDs risk factors were divided into serum lipid profile (main risk factor) and other known risk factors. The meta-analysis was then used to derive a combined OR test for heterogeneity in findings between studies. Twenty-nine articles were included. Our meta-analysis indicated that PFCs exposure could be associated with CVDs (Test for overall effect: z = 2.2, p = 0.02; Test for heterogeneity: I2 = 91.6%, CI = 0.92–1.58, p < 0.0001) and their risk factors (Test for overall effect: z = 4.03, p < 0.0001; Test for heterogeneity: I2 = 85.8%, CI = 1.00–1.14, p < 0.0001). In serum lipids, total cholesterol levels are frequently reported associated with the exposure of PFCs. Among PFCs, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) exposure increased the risk of CVDs than other types of PFCs. Although the risk of PFOA and PFOS were positively associated with CVDs and their risk factors, more observational studies shall be carried out to identify the long-term effects of these contaminants in premature CVDs development in patients

Reduction of oxidative-nitrosative stress underlies anticataract effect of topically applied tocotrienol in streptozotocin-induced diabetic rats

<div><p>Cataract, a leading cause of blindness, is of special concern in diabetics as it occurs at earlier onset. Polyol accumulation and increased oxidative-nitrosative stress in cataractogenesis are associated with NFκB activation, iNOS expression, ATP depletion, loss of ATPase functions, calpain activation and proteolysis of soluble to insoluble proteins. Tocotrienol was previously shown to reduce lens oxidative stress and inhibit cataractogenesis in galactose-fed rats. In current study, we investigated anticataract effects of topical tocotrienol and possible mechanisms involved in streptozotocin-induced diabetic rats. Diabetes was induced in <i>Sprague Dawley</i> rats by intraperitoneal injection of streptozotocin. Diabetic rats were treated with vehicle (DV) or tocotrienol (DT). A third group consists of normal, non-diabetic rats were treated with vehicle (NV). All treatments were given topically, bilaterally, twice daily for 8 weeks with weekly slit lamp monitoring. Subsequently, rats were euthanized and lenses were subjected to estimation of polyol accumulation, oxidative-nitrosative stress, NFκB activation, iNOS expression, ATP levels, ATPase activities, calpain activity and total protein levels. Cataract progression was delayed from the fifth week onwards in DT with lower mean of cataract stages compared to DV group (p<0.01) despite persistent hyperglycemia. Reduced cataractogenesis in DT group was accompanied with lower aldose reductase activity and sorbitol level compared to DV group (p<0.01). DT group also showed reduced NFκB activation, lower iNOS expression and reduced oxidative-nitrosative stress compared to DV group. Lenticular ATP and ATPase and calpain 2 activities in DT group were restored to normal. Consequently, soluble to insoluble protein ratio in DT group was higher compared to DV (p<0.05). In conclusion, preventive effect of topical tocotrienol on development of cataract in STZ-induced diabetic rats could be attributed to reduced lens aldose reductase activity, polyol levels and oxidative-nitrosative stress. These effects of tocotrienol invlove reduced NFκB activation, lower iNOS expression, restoration of ATP level, ATPase activities, calpain activity and lens protein levels.</p></div