Relative improvements in road mobility as compared to improvements in road accessibility and urban growth: a panel data analysis

Previous studies revealed that the development of road infrastructure contributed positively to urban growth. However, the demand for and supply of different road types may change according to the level of urbanization, and this might have a significant impact on urban growth. The objectives of this study were twofold. First, to determine the investment level needed for different road types to facilitate urban growth at different levels of urbanization. Second, to understand how the development of different road types promotes export-led urban growth. We apply a fixed-effects panel linear regression analysis on a panel of 60 countries over the period of 1980–2010. The evidence presented in this study suggests that improvements in road mobility promoted export-led urban growth in countries with a low level of urbanization. This implies that policies to facilitate export should be executed in conjunction with high-mobility road network expansion to increase urbanization, especially in countries with a low level of urbanization that commonly suffer from low growth rates and that have a low level of high mobility road networks. Such expansion in road mobility is required to fulfil demands for long-distance travel to transport people from rural to urban areas. In contrast, in countries with a high level of urbanization, more investment is needed to develop roads with high accessibility. Such roads are needed to fulfil daily travel demands as a consequence of urban sprawl and decentralization of employment and populations. Moreover, the evidence shows that per capita education expenditure and physical capital stock per worker contributed to urban growth

Factors related to seatbelt-wearing among rear-seat passengers in Malaysia.

The benefit of wearing a rear seatbelt in reducing the risk of motor vehicle crash-related fatalities and injuries has been well documented in previous studies. Wearing a seatbelt not only reduces the risk of injury to rear-seat passengers, but also reduces the risk of injury to front-seat occupant who could be crushed by unbelted rear-seat passengers in a motor vehicle crash. Despite the benefits of wearing a rear seatbelt, its rate of use in Malaysia is generally low. The objective of this study was to identify factors that are associated with the wearing of a seatbelt among rear-seat passengers in Malaysia. Multinomial logistic regression analysis of the results of a questionnaire survey of 1651 rear-seat passengers revealed that rear-seat passengers who were younger, male, single and less educated and who had a perception of a low level of legislation enforcement, a lower risk-aversion and less driving experience (only for passengers who are also drivers) were less likely to wear a rear seatbelt. There was also a significant positive correlation between driver seatbelt and rear seatbelt-wearing behaviour. This implies that, in regards to seatbelt-wearing behaviour, drivers are more likely to adopt the same seatbelt-wearing behaviour when travelling as rear-seat passengers as they do when driving. These findings are crucial to the development of new interventions to increase the compliance rate of wearing a rear seatbelt

Role of sensory and cognitive conspicuity in the prevention of collisions between motorcycles and trucks at T-intersections

Motorcyclists are particularly vulnerable to injury in crashes with heavy vehicles due to substantial differences in vehicle mass, the degree of protection and speed. There is a considerable difference in height between motorcycles and trucks; motorcycles are viewed by truck drivers from downward angles, and shorter distances between them mean steeper downward angles. Hence, we anticipated that the effects of motorcycle conspicuity treatments would be different for truck drivers. Therefore, this study aims to evaluate the effects of motorcycle conspicuity treatments on the identification and detection of motorcycles by truck drivers. Two complementary experiments were performed; the first experiment assessed the impact of motorcycle sensory conspicuity on the ability of un-alerted truck drivers to detect motorcycles, and the second experiment assessed the motorcycle cognitive conspicuity to alerted truck drivers. The sensory conspicuity was measured in terms of motorcycle detection rates by un-alerted truck drivers when they were not anticipating a motorcycle within a realistic driving scene, while the cognitive conspicuity was determined by the time taken by alerted truck drivers to actively search for a motorcycle. In the first experiment, the participants were presented with 10 pictures and were instructed to report the kinds of vehicles that were presented in the pictures. Each picture was shown to the participants for 600 ms. In the second experiment, the participants were presented with the same set of pictures and were instructed to respond by clicking the right button on a mouse as soon as they detected a motorcycle in the picture. The results indicate that the motorcycle detection rate increases, and the response time to search for a motorcycle decreases, as the distance between the targeted motorcycle and the viewer decreases. This is true regardless of the type of conspicuity treatment used. The use of daytime running headlights (DRH) was found to increase the detection rate and the identification of a motorcycle by a truck driver at a farther distance, but effect deteriorates as the distance decreases. The results show that the detection rate and the identification of a motorcyclist wearing a black helmet with a reflective sticker increases as the distance between the motorcycle and the truck decreases. We also found that a motorcyclist wearing a white helmet and a white outfit is more identifiable and detectable at both shorter and longer distances. In conclusion, although this study provides evidence that the use of appropriate conspicuity treatments enhances motorcycle conspicuity to truck drivers, we suggest that more attention should be paid to the effect of background environment on motorcycle conspicuity

Performance of Hybrid Steel Fibers Reinforced Concrete Subjected to Air Blast Loading

This paper presents the results of the experimental data and simulation on the performance of hybrid steel fiber reinforced concrete (HSFRC) and also normal reinforced concrete (NRC) subjected to air blast loading. HSFRC concrete mix consists of a combination of 70% long steel hook end fibre and also 30% of short steel hook end fibre with a volume fraction of 1.5% mix. A total of six concrete panels were subjected to air blast using plastic explosive (PE4) weighing 1 kg each at standoff distance of 0.3 meter. The parameters measured are mode of failure under static and blast loading and also peak overpressure that resulted from detonation using high speed data acquisition system. In addition to this simulation work using AUTODYN was carried out and validated using experimental data. The experimental results indicate that hybrid steel fiber reinforced concrete panel (HSFRC) possesses excellent resistance to air blast loading as compared to normal reinforced concrete (NRC) panel. The simulation results were also found to be close with experimental data. Therefore the results have been validated using experimental data

Estimating the potential of skid incident at airport runway – a case study

Skid resistance or friction on airport pavement plays an essential role in runway safety to ensure safe stopping distance. It also provides safety margins during take off and landing of aircraft especially in directional control by reducing the occurrence of overrun and veer-off incidents. The friction between pavement and tire is related to multiple factors such as pavement surface characteristics (microtexture and macrotexture), material intruded between tire and pavement surface (water, snow, and contaminants), tire conditions (types, wear, and inflation pressure), and vehicle operating conditions (vehicle speed and whether the wheel is rolling or locked). Skid incidents due to wet pavement surface at airport runway is a major concern especially in regions of wet-tropical climate countries such as Malaysia. Thus, this study was undertaken to measure the potential of skid incident at airport runway by collecting data on pavement surface characteristics. Field data collection on pavement surface microtexture was conducted using the British Pendulum Tester at a local airport runway to obtain data for the estimation of the skid number (SN). Due to constraints, pavement surface macrotexture test was unable to be conducted at site. However, the pavement surface macrotexture was able to be estimated based on previous research. The potential of the skid incident was estimated by calculating the SN using the aircraft’s touch down speed at the airport runway, varies from 50 to 70 knots (57.5 – 80.6 mph or 92.6 – 129.6 km/h). The results of the estimation indicated that the possibility of the skid incident occurrence was high. This study provides useful insights for airport authority to investigate the potential of overrun and veer-off incidents of aircraft at the airport runway

MicroRNA-145 Regulates Human Corneal Epithelial Differentiation

Epigenetic factors, such as microRNAs, are important regulators in the self-renewal and differentiation of stem cells and progenies. Here we investigated the microRNAs expressed in human limbal-peripheral corneal (LPC) epithelia containing corneal epithelial progenitor cells (CEPCs) and early transit amplifying cells, and their role in corneal epithelium.Human LPC epithelia was extracted for small RNAs or dissociated for CEPC culture. By Agilent Human microRNA Microarray V2 platform and GeneSpring GX11.0 analysis, we found differential expression of 18 microRNAs against central corneal (CC) epithelia, which were devoid of CEPCs. Among them, miR-184 was up-regulated in CC epithelia, similar to reported finding. Cluster miR-143/145 was expressed strongly in LPC but weakly in CC epithelia (P = 0.0004, Mann-Whitney U-test). This was validated by quantitative polymerase chain reaction (qPCR). Locked nucleic acid-based in situ hybridization on corneal rim cryosections showed miR-143/145 presence localized to the parabasal cells of limbal epithelium but negligible in basal and superficial epithelia. With holoclone forming ability, CEPCs transfected with lentiviral plasmid containing mature miR-145 sequence gave rise to defective epithelium in organotypic culture and had increased cytokeratin-3/12 and connexin-43 expressions and decreased ABCG2 and p63 compared with cells transfected with scrambled sequences. Global gene expression was analyzed using Agilent Whole Human Genome Oligo Microarray and GeneSpring GX11.0. With a 5-fold difference compared to cells with scrambled sequences, miR-145 up-regulated 324 genes (containing genes for immune response) and down-regulated 277 genes (containing genes for epithelial development and stem cell maintenance). As validated by qPCR and luciferase reporter assay, our results showed miR-145 suppressed integrin β8 (ITGB8) expression in both human corneal epithelial cells and primary CEPCs.We found expression of miR-143/145 cluster in human corneal epithelium. Our results also showed that miR-145 regulated the corneal epithelium formation and maintenance of epithelial integrity, via ITGB8 targeting

Intravenous alteplase for stroke with unknown time of onset guided by advanced imaging: systematic review and meta-analysis of individual patient data

Background: Patients who have had a stroke with unknown time of onset have been previously excluded from thrombolysis. We aimed to establish whether intravenous alteplase is safe and effective in such patients when salvageable tissue has been identified with imaging biomarkers. Methods: We did a systematic review and meta-analysis of individual patient data for trials published before Sept 21, 2020. Randomised trials of intravenous alteplase versus standard of care or placebo in adults with stroke with unknown time of onset with perfusion-diffusion MRI, perfusion CT, or MRI with diffusion weighted imaging-fluid attenuated inversion recovery (DWI-FLAIR) mismatch were eligible. The primary outcome was favourable functional outcome (score of 0–1 on the modified Rankin Scale [mRS]) at 90 days indicating no disability using an unconditional mixed-effect logistic-regression model fitted to estimate the treatment effect. Secondary outcomes were mRS shift towards a better functional outcome and independent outcome (mRS 0–2) at 90 days. Safety outcomes included death, severe disability or death (mRS score 4–6), and symptomatic intracranial haemorrhage. This study is registered with PROSPERO, CRD42020166903. Findings: Of 249 identified abstracts, four trials met our eligibility criteria for inclusion: WAKE-UP, EXTEND, THAWS, and ECASS-4. The four trials provided individual patient data for 843 individuals, of whom 429 (51%) were assigned to alteplase and 414 (49%) to placebo or standard care. A favourable outcome occurred in 199 (47%) of 420 patients with alteplase and in 160 (39%) of 409 patients among controls (adjusted odds ratio [OR] 1·49 [95% CI 1·10–2·03]; p=0·011), with low heterogeneity across studies (I2=27%). Alteplase was associated with a significant shift towards better functional outcome (adjusted common OR 1·38 [95% CI 1·05–1·80]; p=0·019), and a higher odds of independent outcome (adjusted OR 1·50 [1·06–2·12]; p=0·022). In the alteplase group, 90 (21%) patients were severely disabled or died (mRS score 4–6), compared with 102 (25%) patients in the control group (adjusted OR 0·76 [0·52–1·11]; p=0·15). 27 (6%) patients died in the alteplase group and 14 (3%) patients died among controls (adjusted OR 2·06 [1·03–4·09]; p=0·040). The prevalence of symptomatic intracranial haemorrhage was higher in the alteplase group than among controls (11 [3%] vs two [<1%], adjusted OR 5·58 [1·22–25·50]; p=0·024). Interpretation: In patients who have had a stroke with unknown time of onset with a DWI-FLAIR or perfusion mismatch, intravenous alteplase resulted in better functional outcome at 90 days than placebo or standard care. A net benefit was observed for all functional outcomes despite an increased risk of symptomatic intracranial haemorrhage. Although there were more deaths with alteplase than placebo, there were fewer cases of severe disability or death. Funding: None

Relative improvements in road mobility compared to improvements in road accessibility, urbanization and economic growth

Roads can be classified according to their level of mobility and accessibility. Roads with higher mobility (i.e. motorways) provide limited access but largely uninterrupted travel with high speeds, thus improving travel time reliability for transporting people and goods. Roads with higher accessibility (i.e. local roads) provide limited mobility but offer more direct routes to specific destinations, generating potential for human interactions and opportunity for socioeconomic activities. Empirical studies indicated that an increase in road length contributed positively to socioeconomic growth. However, an important missing information from previous studies remain in the literatures, which is, what type of roads (either high mobility or high accessibility roads) are needed during different level of country’s development? In order to evaluate the performance of different road types during different level of country’s development, the relative improvements in road mobility compared to improvements in road accessibility (MPA) was computed to evaluate the relationship between MPA and country’s development and the presence of trend changes. Three empirical investigations were conducted and the research objectives are as follows: (1) to evaluate how MPA facilitates export-led growth processes and to determine the investment level needed for different road types to facilitate economic and commercial activities at different developmental levels, (2) to determine the investment level required for different road types in order to facilitate urbanization at different levels of urbanization and to comprehend how the development of MPA promotes exportled urban growth and (3) to assess the indirect effect of MPA on economic growth transmitted through the impacts of MPA on urbanization and exports. To shed light on the above issues, fixed-effects panel linear regression analysis was conducted using time-series cross-sectional data on the MPA and growth data for 60 countries over the period of 31 years, from 1980 to 2010. This first empirical study divided the countries into three groups: (1) countries with a high level of development, (2) countries with a medium level of development and (3) countries with a low level of development. The key finding of this study was that a greater relative improvement in MPA would facilitate export-led growth in countries with a high and medium level of development. This indicates that policy to promote export and high mobility road network expansion should be carried out hand-in-hand to enhance economic growth. This is specifically true for countries with a medium level of development, as these countries generally suffer from lower levels of high mobility road network development. Such expansion in road mobility is necessary to fulfil demands for long-distance travel and enable the transportation of people and goods across regions, thereby facilitating productivity and trade. On the other hand, in countries with a low level of development, more investment is required to build roads with high accessibility. Such road are needed to facilitate local business and trade activities. This is crucial in order to achieve a sustainable economic growth. The second empirical study examine the effect of MPA on urbanization. The evidence presented in this study suggests that improvements in road mobility promoted exportled urban growth in countries with a low level of urbanization. This implies that policies to facilitate export should be executed in conjunction with high mobility road network expansion to increase urbanization, especially in countries with a low level of urbanization that commonly suffer from low growth rates and that have a low level of high mobility road networks. Such expansion in road mobility is required to fulfil demands for long-distance travel to transport people from rural to urban areas. In contrast, in countries with a high level of urbanization, more investment is needed to develop roads with high accessibility. Such roads are needed to fulfil daily travel demands as a consequence of urban sprawl and decentralization of employment and populations. Moreover, the evidence shows that per capita education level and physical capital stock per worker contributed to urbanization. The third empirical study examine the indirect effects MPA on economic growth, transmitted through the effects of MPA on urbanization and exports. The total effects of MPA on economic growth is computed by adding the two indirect effects. The indirect effects of MPA on economic growth were estimated based on the prediction of three different panel models: the first model relates per capita gross domestic product (GDP) with urbanization and exports, the second model associates urbanization with the MPA and the third model links exports with the MPA. The estimated results imply that the growth in MPA appeared to be associated with a rise in per capita GDP at lower level of urbanization and export but associated with a decline in per capita GDP at higher level of urbanization and export. On the other hand, for the indirect effect of MPA on per capita GDP via urbanization, the level of MPA that maximizes per capita GDP decreases with increases in the levels of physical capital stock per worker and per capita education level. For the computation of total effect, the level of MPA that maximizes per capita GDP is ranged between 0.0485 and 0.5860. In summary, this study suggest that policies focused on improving MPA should be implemented hand-in hand with other socioeconomic and urbanization policies, in order to realize a sustainable economic growth. As evidenced by empirical studies conducted in this research, high mobility road network growth alone is not sufficient to put urbanization and economy on a sustainable growth path. Although improvements in road mobility are crucial in countries with a high and medium level of development, improved road accessibility has a greater influence on export growth in countries with a low level of development. The latter can be explained as follows: at lower development levels, populations are more concentrated in smaller areas, and business activities mainly occur at the local scale. Moreover, the findings also revealed that high road accessibility has a more important impact on export growth at a high level of urbanization to support daily travel needs as a result of urban sprawl and the decentralization of employment and population. The empirical evidence indicates that the effect of relative improvements in road mobility was ambiguous, with both positive and negative effects on economic growth observed. Relative improvements in road mobility appear to be accompanied by an increase in per capita GDP at lower levels of urbanization and exports but accompanied by a decrease in per capita GDP at higher levels of urbanization and exports. Therefore, to attain sustainable economic growth, road infrastructure development policies should be implemented alongside exports and urbanization policies. In this research, most of the countries with a low level of development in the sample also had a low level of urbanization. The evidence indicates that in countries with a low level of development, improvements in high accessibility road network promote local business and trade activities. Furthermore, in countries with a low level of urbanization, improvements in high mobility road network facilitate migration from rural to urban areas. Therefore, achieving a balance road infrastructure development between both high mobility and high accessibility road network is crucial to attain sustainable economic and urbanization in countries with a low level of urbanization