[1] This study integrates global data sets for aerosols, cloud physical properties, and shortwave radiation fluxes with a Monte Carlo Aerosol-Cloud-Radiation (MACR) model to estimate both the surface and the top-of-atmosphere (TOA) solar radiation budget as well as atmospheric column solar absorption. The study also quantifies the radiative forcing of aerosols and that of clouds. The observational input to MACR includes data from the Multiangle Imaging Spectroradiometer (MISR) for aerosol optical depths, single scattering albedos, and asymmetry factors; satellite retrieved column water vapor amount; the Total Ozone Mapping Spectrometer (TOMS) total ozone amount; and cloud fraction and cloud optical depth from the Cloud and Earth's Radiant Energy System (CERES) cloud data. The present radiation budget estimates account for the diurnal variation in cloud properties. The model was validated against instantaneous, daily and monthly solar fluxes from the ground-based Baseline Surface Radiation Network (BSRN) network, the Global Energy Balance Archive (GEBA) surface solar flux data, and CERES TOA measurements. The agreement between simulated and observed values are within experimental errors, for all of the cases considered here: instantaneous fluxes and monthly mean fluxes at stations around the world and TOA fluxes and cloud forcing for global annual mean and zonal mean fluxes; in addition the estimated aerosol forcing at TOA also agrees with other observationally derived estimates. Overall, such agreements suggest that global data sets of aerosols and cloud parameters released by recent satellite experiments (MISR, MODIS and CERES) meet the required accuracy to use them as input to simulate the radiative fluxes within instrumental errors. Last, the atmospheric solar absorption derived in this study should be treated as an improved estimate when compared with earlier published studies. The main source of improvement in the present estimate is the use of global distribution of observed parameters for model input such as aerosols and clouds. The agreement between simulated and observed solar fluxes at the surface supports our conclusion that the present estimate is an improvement over previous studies. MACR with the global input data was used to simulate the global and regional solar radiation budget, aerosol radiative forcing and cloud radiative forcing for a 3-year period from 2000 to 2002. We estimate the planetary albedo for a 3-year average to be 28.9 ± 1.2% to be compared with CERES estimate of 28.6% and ERBE's estimate of 29.6%. Without clouds (including aerosols) the planetary albedo is only 15.0 ± 0.6%. The global mean TOA shortwave cloud forcing is À47.5 ± 4 W m À2 , comparing well with the CERES and ERBE estimates of À46.5 and À48 W m TOA and the surface are À6.0 ± 1 W m À2 and À11.0 ± 2 W m À2 , respectively. In the presence of clouds the aerosol radiative forcing is À3.0 ± 1 W m À2 (at TOA) and À7.0 ± 2 W m À2 (at the surface). The study also documents the significant regional variations in the solar radi...

Long-lasting insecticidal nets (LLINs) have been widely used as an effective alternative to conventional insecticide-treated nets (ITNs) for over a decade. Due to the growing number of field trials and interventions reporting the effectiveness of LLINs in controlling malaria, there is a need to systematically review the literature on LLINs and ITNs to examine the relative effectiveness and characteristics of both insecticide nettings. A systematic review of over 2000 scholarly articles published since the year 2000 was conducted. The odds ratios (ORs) of insecticidal net effectiveness in reducing malaria were recorded. The final dataset included 26 articles for meta-regression analysis, with a sample size of 154 subgroup observations. While there is substantial heterogeneity in study characteristics and effect size, we found that the overall OR for reducing malaria by LLIN use was 0.44 (95% CI = 0.41–0.48, p < 0.01) indicating a risk reduction of 56%, while ITNs were slightly less effective with an OR of 0.59 (95% CI = 0.57–0.61, p <0.01). A meta-regression model confirms that LLINs are significantly more effective than ITNs in the prevention of malaria, when controlling for other covariates. For both types of nets, protective efficacy was greater in high transmission areas when nets were used for an extended period. However, cross-sectional studies may overestimate the effect of the nets. The results surprisingly suggest that nets are less effective in protecting children under the age of five, which may be due to differences in child behavior or inadequate coverage. Compared to a previous meta-analysis, insecticide-treated nets appear to have improved their efficacy despite the risks of insecticide resistance. These findings have practical implications for policymakers seeking effective malaria control strategies.

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The demand function for vaccines against typhoid fever was estimated using stated preference data collected from a random sample of 1065 households in Hue, Vietnam, in 2002. These are the first estimates of private willingness-to-pay (WTP) and demand functions for typhoid vaccines in a developing country. Mean respondent WTP for a single typhoid fever vaccine ranged from USD 2.30 to USD 4.80. Mean household WTP estimates (vaccinating all members of the household) ranged from USD 21 to USD 27. Demand was similar for vaccines with different degrees of effectiveness and intervals of duration. These results suggest a significant potential for private sector provision of typhoid fever vaccines in Hue.