459 research outputs found

    Disaster warning system: Satellite feasibility and comparison with terrestrial systems. Volume 1: Executive summary

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    The Disaster Warning System (DWS) is a conceptual system which will provide the National Weather Service (NWS) with communication services in the 1980s to help minimize losses caused by natural disasters. The object of this study is a comparative analysis between a terrestrial DWS and a satellite DWS. Baseline systems satisfying the NOAA requirements were synthesized in sufficient detail so that a comparison could be made in terms of performance and cost. The cost of both baseline systems is dominated by the disaster warning and spotter reporting functions. An effort was undertaken to reduce system cost through lower-capacity alternative systems generated by modifying the baseline systems. By reducing the number of required channels and modifying the spotter reporting techniques, alternative satellite systems were synthesized. A terrestrial alternative with the coverage reduced to an estimated 95 percent of the population was considered

    Long-term observations of the background aerosol at Cabauw, The Netherlands

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    Long-term measurements of PM2.5 mass concentrations and aerosol particle size distributions from 2008 to 2015, as well as hygroscopicity measurements conducted over one year (2008-2009) at Cabauw, The Netherlands, are compiled here in order to provide a comprehensive dataset for understanding the trends and annual variabilities of the atmospheric aerosol in the region. PM2.5 concentrations have a mean value of 14.4 mu g m(-3) with standard deviation 2.1 mu g m(-3), and exhibit an overall decreasing trend of -0.74 mu g m(-3) year(-1). The highest values are observed in winter and spring and are associated with a shallower boundary layer and lower precipitation, respectively, compared to the rest of the seasons. Number concentrations of particles smaller than 500 nm have a mean of 9.2 x 10(3) particles cm(-3) and standard deviation 4.9x10(3) particles cm(-3), exhibiting an increasing trend between 2008 and 2011 and a decreasing trend from 2013 to 2015. The particle number concentrations exhibit highest values in spring and summer (despite the increased precipitation) due to the high occurrence of nucleation-mode particles, which most likely are formed elsewhere and are transported to the observation station. Particle hygroscopicity measurements show that, independently of the air mass origin, the particles are mostly externally mixed with the more hydrophobic mode having a mean hygroscopic parameter kappa of 0.1 while for the more hydrophilic mode kappa is 0.35. The hygroscopicity of the smaller particles investigated in this work (i.e., particles having diameters of 35 nm) appears to increase during the course of the nucleation events, reflecting a change in the chemical composition of the particles. (C) 2017 Elsevier B.V. All rights reserved.Peer reviewe

    [18F]FDG Uptake in Adipose Tissue Is Not Related to Inflammation in Type 2 Diabetes Mellitus

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    PURPOSE: 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) uptake is a marker of metabolic activity and is therefore used to measure the inflammatory state of several tissues. This radionuclide marker is transported through the cell membrane via glucose transport proteins (GLUTs). The aim of this study is to investigate whether insulin resistance (IR) or inflammation plays a role in [18F]FDG uptake in adipose tissue (AT). PROCEDURES: This study consisted of an in vivo clinical part and an ex vivo mechanistic part. In the clinical part, [18F]FDG uptake in abdominal visceral AT (VAT) and subcutaneous AT (SAT) was determined using PET/CT imaging in 44 patients with early type 2 diabetes mellitus (T2DM) (age 63 [54-66] years, HbA1c [6.3 ± 0.4 %], HOMA-IR 5.1[3.1-8.5]). Plasma levels were measured with ELISA. In the mechanistic part, AT biopsies obtained from 8 patients were ex vivo incubated with [18F]FDG followed by autoradiography. Next, a qRT-PCR analysis was performed to determine GLUT and cytokine mRNA expression levels. Immunohistochemistry was performed to determine CD68+ macrophage infiltration and GLUT4 protein expression in AT. RESULTS: In vivo VAT [18F]FDG uptake in patients with T2DM was inversely correlated with HOMA-IR (r = - 0.32, p = 0.034), and positively related to adiponectin plasma levels (r = 0.43, p = 0.003). Ex vivo [18F]FDG uptake in VAT was not related to CD68+ macrophage infiltration, and IL-1ß and IL-6 mRNA expression levels. Ex vivo VAT [18F]FDG uptake was positively related to GLUT4 (r = 0.83, p = 0.042), inversely to GLUT3 (r = - 0.83, p = 0.042) and not related to GLUT1 mRNA expression levels. CONCLUSIONS: In vivo [18F]FDG uptake in VAT from patients with T2DM is positively correlated with adiponectin levels and inversely with IR. Ex vivo [18F]FDG uptake in AT is associated with GLUT4 expression but not with pro-inflammatory markers. The effect of IR should be taken into account when interpreting data of [18F]FDG uptake as a marker for AT inflammation

    Economic Transition and Natural Resource Management in East-and Southeast Asia

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    Abstract: For several decades the effective and efficient dissemination of new agricultural knowledge among farmers in developing countries has been problematic. Two major programs were implemented in Indonesia, namely The Training and Visit (T&V) Extension Program or The Massive Guidance (BIMAS) Program, from the mid 1960s until the end of the1980s, and the Farmer Field School (FFS) Program, during the 1990s. The main difference between these two programs is that, where the T&V was concerned, farmers were instructed what to do, while the FFS program encouraged and stimulated farmers to make their own decisions. This paper aims to discuss and compare the effectiveness of these two programs with reference to rice production in Indonesia. This paper would like to argue that, for regions where the level of development is still very low, implementing a T&V program instructing farmers what to do is probably more appropriate than an FFS. As for regions where agriculture is relatively developed, an effective FFS program is more appropriate

    Brain stem encephalitis is a rare complication of COVID-19

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    Here, we describe the clinical phenotype of SARS-CoV-2-related CNS disease and evaluate the SARS-CoV-2 antibody index as a tool to differentiate between a direct (viral) and indirect etiology. Out of >4000 hospitalized patients with COVID-19, we included 13 patients with neurological symptoms with suspicion of neuroinflammation. On clinical grounds, eight were classified as having a possible/probable relationship between neurological symptoms and COVID-19. A clinically distinctive phenotype of brainstem and cerebellar symptoms was seen in 6/8 patients. As we found a positive SARS-CoV-2 antibody index in 3/5 patients, indicating specific intrathecal SARS-CoV-2 IgG production, a direct link with SARS-CoV-2 is likely

    Detailed electronic structure studies on superconducting MgB2_2 and related compounds

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    In order to understand the unexpected superconducting behavior of MgB2_2 compound we have made electronic structure calculations for MgB2_2 and closely related systems. Our calculated Debye temperature from the elastic properties indicate that the average phonon frequency is very large in MgB2_2 compared with other superconducting intermetallics and the exceptionally high TcT_c in this material can be explained through BCS mechanism only if phonon softening occurs or the phonon modes are highly anisotropic. We identified a doubly-degenerate quasi-two dimensional key-energy band in the vicinity of EFE_{F} along Γ\Gamma-A direction of BZ which play an important role in deciding the superconducting behavior of this material. Based on this result, we have searched for similar kinds of electronic feature in a series of isoelectronic compounds such as BeB2_2, CaB2_2, SrB2_2, LiBC and MgB2_2C2_2 and found that MgB2_2C2_2 is one potential material from the superconductivity point of view. There are contradictory experimental results regarding the anisotropy in the elastic properties of MgB2_2 ranging from isotropic, moderately anisotropic to highly anisotropic. In order to settle this issue we have calculated the single crystal elastic constants for MgB2_2 by the accurate full-potential method and derived the directional dependent linear compressibility, Young's modulus, shear modulus and relevant elastic properties. We have observed large anisotropy in the elastic properties. Our calculated polarized optical dielectric tensor shows highly anisotropic behavior even though it possesses isotropic transport property. MgB2_2 possesses a mixed bonding character and this has been verified from density of states, charge density and crystal orbital Hamiltonian population analyses

    The Evolution of Bat Vestibular Systems in the Face of Potential Antagonistic Selection Pressures for Flight and Echolocation

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    PMCID: PMC3634842This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
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