5 research outputs found
Ambient particulate air pollution and daily mortality in 652 cities
BACKGROUND : The systematic evaluation of the results of time-series studies of air pollution is challenged
by differences in model specification and publication bias.
METHODS : We evaluated the associations of inhalable particulate matter (PM) with an aerodynamic
diameter of 10 ÎĽm or less (PM10) and fine PM with an aerodynamic diameter of 2.5 ÎĽm
or less (PM2.5) with daily all-cause, cardiovascular, and respiratory mortality across multiple
countries or regions. Daily data on mortality and air pollution were collected from 652
cities in 24 countries or regions. We used overdispersed generalized additive models with
random-effects meta-analysis to investigate the associations. Two-pollutant models were
fitted to test the robustness of the associations. Concentration–response curves from each
city were pooled to allow global estimates to be derived.
RESULTS : On average, an increase of 10 ÎĽg per cubic meter in the 2-day moving average of PM10
concentration, which represents the average over the current and previous day, was associated
with increases of 0.44% (95% confidence interval [CI], 0.39 to 0.50) in daily all-cause
mortality, 0.36% (95% CI, 0.30 to 0.43) in daily cardiovascular mortality, and 0.47% (95%
CI, 0.35 to 0.58) in daily respiratory mortality. The corresponding increases in daily mortality
for the same change in PM2.5 concentration were 0.68% (95% CI, 0.59 to 0.77), 0.55%
(95% CI, 0.45 to 0.66), and 0.74% (95% CI, 0.53 to 0.95). These associations remained
significant after adjustment for gaseous pollutants. Associations were stronger in locations
with lower annual mean PM concentrations and higher annual mean temperatures. The
pooled concentration–response curves showed a consistent increase in daily mortality with
increasing PM concentration, with steeper slopes at lower PM concentrations.
CONCLUSIONS : Our data show independent associations between short-term exposure to PM10 and PM2.5
and daily all-cause, cardiovascular, and respiratory mortality in more than 600 cities across
the globe. These data reinforce the evidence of a link between mortality and PM concentration
established in regional and local studies.The National Natural Science
Foundation of China and othershttp://www.nejm.orgam2020Geography, Geoinformatics and Meteorolog
Modified Problem-Based Learning in accounting curriculum
This paper proposes the use of a bounded problem based learning (BPBL) approach in an accounting curriculum. Studies have shown that PBL is designed to (1) promote lifelong learning, (2) integrate theory with practice, (3) develop soft skills and (4) confront multifaceted problems, hence aiding in students’ exposure to the real world. Little research has been done on the use of PBL in an accounting context. This paper argues for and serves as a guide for the use of a BPBL approach in multidisciplinary accounting modules. Results from our exploratory study indicates that students generally prefer the BPBL approach and there was significant intelligence improvement observed from using this approach
Geographical distribution of red and green Noctiluca scintillans
The dinoflagellate Noctiluca scintillans is one of the most important and abundant red tide organisms and it is distributed world-wide. It occurs in two forms. Red Noctiluca is heterotrophic and fills the role of one of the microzooplankton grazers in the foodweb. In contrast, green Noctiluca contains a photosynthetic symbiont Pedinomonas noctilucae (a prasinophyte), but it also feeds on other plankton when the food supply is abundant. In this review, we document the global distribution of these two forms and include the first maps of their global distribution. Red Noctiluca occurs widely in the temperate to sub-tropical coastal regions of the world. It occurs over a wide temperature range of about 10°C to 25°C and at higher salinities (generally not in estuaries). It is particularly abundant in high productivity areas such as upwelling or eutrophic areas where diatoms dominate since they are its preferred food source. Green Noctiluca is much more restricted to a temperature range of 25°C–30°C and mainly occurs in tropical waters of Southeast Asia, Bay of Bengal (east coast of India), in the eastern, western and northern Arabian Sea, the Red Sea, and recently it has become very abundant in the Gulf of Oman. Red and green Noctiluca do overlap in their distribution in the eastern, northern and western Arabian Sea with a seasonal shift from green Noctiluca in the cooler winter convective mixing, higher productivity season, to red Noctiluca in the more oligotrophic warmer summer season