Grazing effects of sea urchin Diadema savignyi on algal abundance and coral recruitment processes.

Herbivores control algae and promote coral dominance along coral reefs. However, the majority of previous studies have focused on herbivorous fish. Here we investigated grazing effects of the sea urchin Diadema savignyi on algal abundance and coral recruitment processes. We conducted an in situ cage experiment with three density conditions of D. savignyi (0, 8, 16 indiv. m-2) for three months during the main coral recruitment season in Taiwan. Results demonstrated a strong algal control by D. savignyi. At the end of the experiment, average algal cover was 95% for 0 indiv. m-2, compared to 47% for 8 indiv. m-2 and 16% for 16 indiv. m-2. Average algal biomass at 8 indiv. m-2 declined by one third compared to 0 indiv. m-2 and almost zero at 16 indiv. m-2. On the other hand, a negative grazing effect of D. savignyi was observed on coral recruitment processes. Notably, at 16 indiv. m-2, the density of coral recruits declined and mortality of small coral fragments (proxy of coral juveniles) increased. Our results confirm findings of previous studies and indicate the need to balance both positive (strong algal control) and negative (physical damage) influences of Diadema grazing to facilitate the coral recruitment process.

Evaluation of the Vietnamese A6 Mortality Reporting System: All-Cause Mortality.

There has been no systematic evaluation of Viet Nam's A6 mortality reporting system. An evaluation was undertaken in 3 provinces in Viet Nam. Deaths identified in the A6 system were compared with deaths identified by an independent consensus panel to determine the percentage completeness of the A6 system. Verbal autopsies (VAs) were conducted for all identified deaths from the consensus panels, and the sensitivity and positive predictive value of the A6 system was assessed. The sensitivity of the A6 system varied depending on the cause of death, with the sensitivity of the system being excellent for injury (sensitivity = 75.4%), cancer (sensitivity = 66.9%), and circulatory diseases (sensitivity = 63.1%). The A6 mortality reporting system performs well in relation to its completeness and classification of 3 leading causes of death­namely, circulatory disease, cancer, and injury. With further enhancements and ongoing support from government and donor agencies, the A6 system will be a valuable resource.

Evaluation of the Vietnamese A6 mortality reporting system: injury as a cause of death.

BACKGROUND: Despite the fact that the A6 mortality reporting system has been operating for almost 20 years in Vietnam, there has been no systematic evaluation of the system. This study assesses the completeness, sensitivity and positive predictive value of the system in relation to injury related mortality. METHODS: Evaluation of the A6 system was undertaken in three (geographically distributed) provinces in Vietnam. Deaths identified in the A6 system were compared with deaths identified by an independent consensus panel to determine the per cent completeness of the A6 system. Verbal autopsies (VA) were conducted for all identified deaths from the consensus panels, and the sensitivity and positive predictive value of the A6 system were assessed using the VAs as the reference. RESULTS: 5273 deaths were identified from the A6 system with a further 340 cases identified by the independent consensus panel (total n=5613). Injury related deaths accounted for 13.6% (n=763) of all deaths with an overall injury mortality rate of 55.3 per 100 000 person years. The per cent completeness of the A6 system in relation to injury deaths was 93.9% with a sensitivity of 75.4%, specificity of 98.4% and positive predictive value of 88.4%. CONCLUSIONS: The A6 mortality reporting system is embedded within the commune health system and is the lead mortality reporting system for the Ministry of Health. The system performs well in relation to its completeness and classification of injury related deaths. With further enhancements and ongoing support from government and donor agencies, the A6 system will be a valuable resource for identifying and planning preventive strategies targeting the leading causes of injury related deaths in Vietnam.

Barriers to, and factors associated, with observed motorcycle helmet use in Vietnam.

This study investigated barriers to, and factors associated with, observed motorcycle helmet use among motorcyclists in Hai Duong Province, Vietnam. The findings highlighted an array of factors associated with observed helmet use namely, support for universal helmet legislation and a positive attitude towards what might be perceived as negative attributes of helmet use such as inconvenience and discomfort in hot weather. As well, older age (greater than 25 years in age), riding on a compulsory road, being a driver, trips of greater than 10 km, higher levels of education (having a university degree and higher) were found to be key determinants of helmet use. Despite over 95% of motorcyclists disagreeing with the statement that wearing a helmet does not reduce the severity of head injury in a crash, most motorcyclists believed that helmets did not need to be worn for a short trip. Overall, only 23% of motorcyclists were observed wearing a helmet. The authors conclude that efforts to increase helmet use need to focus on the necessity for universal helmet legislation in association with identifying solutions to reduce the negative attitudes towards helmet use.

Motorcycle helmets in Vietnam: ownership, quality, purchase price, and affordability.

OBJECTIVES: This study investigated motorcycle helmet ownership, quality, purchase price, and affordability in Vietnam. METHOD: A random sample of motorcyclists was interviewed to investigate aspects of helmet ownership, the purchase price, and affordability of a motorcycle helmet. Multivariate modeling conducted to determine factors associated with the purchase price and affordability of motorcycle helmets. Helmet quality was assessed based on current legal requirements in Vietnam. RESULTS: The prevalence of helmet use in Vietnam remains low (23.3%) despite a high level of helmet ownership (94%), indicating that this is an important area for public health intervention. Overall the quality of helmets appeared to be good; however, few helmets displayed legally required information. Motorcyclists with a high income purchase more helmets for their household rather than more expensive helmets. CONCLUSION: To ensure that helmets are accessible to the community, policy-makers need to consider pricing motorcycle helmets at a price indicated by the results of this study. Prior to universal motorcycle helmet legislation, the government will also need to ensure that standard helmets are available and that enforcement is at a level to ensure that motorcycle helmets are actually used.