The Demographic Transition in Closed and Open Economies: A Tale of Two Regions

This paper constructs a general equilibrium overlapping generation model to evaluate quantitatively how demographic transition (falling mortality and fertility rates) affects aggregate variables (wages, interest rate, output), and inter-generational welfare in closed and open economies. We perform this analysis for two economies calibrated to resemble the North (US and Europe) and Latin America. Our simulations suggest that the demographic transition could have generated income per capita growth up to 0. 5% per year in excess of steady-state growth in the past 50 years in Latin America and 0. 3% in the North.

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Quantitative Assessment of Asbestos Fibers in Normal and Pathological Pleural Tissue—A Scoping Review

Background: pleural mesothelioma is a rare cancer in the general population, but it is more common in subjects occupationally exposed to asbestos. Studies with asbestos fiber quantification in pleural tissue are scarce: for this reason, we aimed at undertaking a scoping review to summarize the evidence provided by studies in which asbestos fibers were determined by electron microscopy (SEM or TEM) in human pleural tissues, whether normal or pathologic. Materials and methods: A scoping review of articles that quantified asbestos fibers in human pleural tissue (normal or pathologic) by electron microscopy (SEM or TEM), in subjects with asbestos exposure (if any) was performed. Results: The 12 studies selected comprised 137 cases, out of which 142 samples were analyzed. Asbestos fibers were detected in 111 samples (78%) and were below the detectable limit in 31 samples (22%). The concentration of asbestos fibers detected in the positive samples was distributed from as low as 0.01 mfgdt (millions of fibers per gram of dry tissue) up to 240 mfgdt. However, the minimum concentration of fibers overlaps in the three types of tissues (normal pleura, pleural plaque, mesothelioma) in terms of magnitude; therefore, it is not possible to distinguish a definite pattern which differentiates one tissue from the other. Conclusions: The studies included were heterogeneous as to the representativeness of the samples and analytical techniques; the possibility of false negatives must be considered. It would be desirable to systematically search for asbestos fibers to fill the knowledge gap about the presence of asbestos fibers in normal or pathological pleural tissue in order to better understand the development of the different pleural diseases induced by this mineral

Scalable interconnections for remote indirect exciton systems based on acoustic transport

Excitons, quasiparticles consisting of electron-hole pairs bound by the Coulomb interaction, are a potential medium for the processing of photonic information in the solid state. Information processing via excitons requires efficient techniques for the transport and manipulation of these uncharged particles.We have carried out a detailed investigation of the transport of excitons in GaAs quantum wells by surface acousticwaves. Based on these results, we introduce here a concept for the interconnection of multiple remote exciton systems based on the long-range transport of dipolar excitons by a network of configurable interconnects driven by acoustic wave beams. By combining this network with electrostatic gates, we demonstrate an integrated exciton multiplexer capable of interconnecting, gating, and routing exciton systems separated by millimeter distances. The multiplexer provides a scalable platform for the manipulation of exciton fluids with potential applications in information processingFinancial support by DFG Project No. SA 598/

A low-cost stereo video system for measuring directional wind waves

Typical oceanographic instruments are expensive, complex to build, and hard to deploy and require constant and specialized maintenance. In this paper, we present a cheap and simple technique to estimate a three-dimensional surface elevation map, n (x, y, t), the directional spectrum, and the main sea state parameters using inexpensive smartphones. The proposed methodology uses Time Lagged Cross Correlation (TLCC) between the audio signals from two independent video records to perform the frame synchronization. This makes the system much easier to deploy, where the main requirement is a fixed or moving platform close to the sea. The time records are mostly limited by the equipment storage space and battery life, although it can be easily replaced or recharged. Here, we pose the basis for an inexpensive yet powerful stereo reconstruction device and discuss its capabilities and limitations. The smartphone system capabilities were illustrated here by near shore experiment, at Leme beach in the Southeast of Brazil, and the results were compared against a pressure sensor. For this particular setup, the root mean square error in terms of significant wave height is of the order of 11% with perfect estimation of the peak period. The results are promising and demonstrate the validity and applicability of the technique