Synthesis of Eu(3+)- and Er(3+)/Yb(3+)-doped GdVO4 nanoparticles in reverse micelles and their multifunctional luminescence properties are presented. Using cyclohexane, Triton X-100, and n-pentanol as the oil, surfactant, and co-surfactant, respectively, crystalline nanoparticles with ~4 nm diameter are prepared at low temperatures. The particle size assessed using transmission electron microsc...

Bulk yttrium oxysulfide phosphors were prepared using the polysulfide flux method. The morphology and structure was characterized using transmission electron microscopy and x-ray powdered diffraction. Visible emissions occurring near 530 and 550 nm and 660 670 nm consistent with the H11/2, S3/2 → I15/2 and F9/2 → I15/2 transitions, respectively, were observed under 808, 980, and 1560 nm excitat...

La2O2S:Er ,Yb nanocrystalline up-converting phosphors were synthesized by a combustion method at low temperature, using ethanol as pre-ignition fuel and thioacetamide as sulfurizing agent and organic fuel. The phosphors were characterized by powder X-ray diffractometry, scanning electron microscopy, UV/Vis/NIR spectroscopy and fluorescence spectroscopy. Pure and well-crystallized La2O2S:Er ,Yb ...

The fatty acid composition of Listeria monocytogenes Scott A was determined by close-interval sampling over the entire biokinetic temperature range. There was a high degree of variation in the percentage of branched-chain fatty acids at any given temperature. The percentage of branched C17 components increased with growth temperature in a linear manner. However, the percentages of iso-C15:0 (i1...

Oleic acid-capped NaYF4:Yb(3+)/Er(3+) upconversion nanocrystals (UCNCs) with different sizes and crystalline phases were prepared, and their temperature-dependent upconversion luminescence (UCL) and dynamics were studied. It is interesting to observe that the temperature-dependent behavior of UCL for the β-phase (25 nm, 45 nm and bulk) and α-phase (<10 nm) UCNCs is quite different. The UCL inte...

The Transformation of Hunger Revisited We examine Trevon Logan’s 2009 claim to have found low levels of nutrition among British worker’s households in the late 19 century. Using the same data, we conclude that Logan’s estimates are thirty percent too low. Logan buttressed his estimates by claiming that the income elasticity of calories demand was unusually high among these households, relative ...

Heavily subsidizing essential health products through existing health infrastructure could substantially improve health in sub-Saharan Africa. There is, however, widespread concern that poor governance – in particular, limited health worker accountability – seriously undermines the effectiveness of subsidy programs. Using innovative audits of targeted bed net distribution programs in Ghana, Ken...

This study estimates the impact of an American rural public health program on child mortality over 1908 to 1933. Due to the absence of sanitation and childoriented health services outside of urban areas, public and private agencies sponsored county-level health departments (CHDs) throughout the US. Variation in the location and timing of the CHDs identifies improvements in population health, wh...

We estimate the effect of malaria on settlement and land use patterns in the Brazilian Amazon, where potential settlers were randomly assigned to plots in a newly opened settlement area. The random assignment allows us to estimate the risk of malaria on each plot based only on its characteristics. Using survey data, we find that a high malaria risk significantly reduces the probability that a p...

Environmental pollution and human health problems are becoming serious issues in China. This research focuses on regional differences in productive inefficiencies and attempts to clarify the determinants of inefficiency, accounting economic, environmental and health-related factors. Our dataset includes information of 29 areas in China from 2003 to 2009. We find that after accounting for enviro...