265 research outputs found

    A decision-making framework for school infrastructure improvement programs

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    School infrastructure affects the quality of education and the performance of children and youth. Natural hazards such as earthquakes, hurricanes, floods, and landslides, threaten critical infrastructure such as school facilities. Additionally, problems related to the functionality of these facilities are common in the region, such as an inadequate number of classrooms, poor lighting, and insufficient ventilation, among others. At a national level, the decision-making process to prioritize schools’ interventions becomes even more challenging due to limited resources and lack of information. Furthermore, there is a lack of a systematic approach to address the need of improving existing infrastructure taking into consideration limited resources. Considering this, a novel decision-making framework is proposed that prioritizes school infrastructure investment with limited budgets, using clustering procedures, a multi-criteria utility function, and an optimization component. This framework allows better public policy decisions and benefits students in terms of buildings quality with a multi-criteria perspective, improving both safety and functional conditions. The framework is illustrated with a case study applied to the public-school infrastructure in the Dominican Republic

    The role of formyl peptide receptors in permanent and low-grade inflammation: Helicobacter pylori infection as a model

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    Formyl peptide receptors (FPRs) are cell surface pattern recognition receptors (PRRs), belonging to the chemoattractant G protein-coupled receptors (GPCRs) family. They play a key role in the innate immune system, regulating both the initiation and the resolution of the inflammatory response. FPRs were originally identified as receptors with high binding affinity for bacteria or mitochondria N-formylated peptides. However, they can also bind a variety of structurally different ligands. Among FPRs, formyl peptide receptor-like 1 (FPRL1) is the most versatile, recognizing N-formyl peptides, non-formylated peptides, and synthetic molecules. In addition, according to the ligand nature, FPRL1 can mediate either pro-or anti-inflammatory responses. Hp(2-20), a Helicobacter pylori-derived, non-formylated peptide, is a potent FPRL1 agonist, participating in Helicobacter pylori-induced gastric inflammation, thus contributing to the related site or not-site specific diseases. The aim of this review is to provide insights into the role of FPRs in H. pylori-associated chronic inflammation, which suggests this receptor as potential target to mitigate both microbial and sterile inflammatory diseases

    Towards disaster risk mitigation on large-scale school intervention programs

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    Education infrastructure is one of the main barriers on school quality in Low- and Middle-Income Countries (L&MICs), since it is insufficient and unevenly distributed. Improving the school infrastructure is needed to provide a high-quality education environment. Although research on how to improve the infrastructure is available, there is still a lack of a consistent and systematic approach to develop large-scale interventions at the national or regional level. To fill this gap, we propose a data-driven methodology with the purpose of developing a prioritization of interventions to carry out a seismic disaster risk reduction program. The method starts by identifying groups of similar buildings using clustering analysis, starting with a seismic taxonomy as descriptor (i.e., model input). Then, domain experts analyze the suggested clusters to design scalable interventions for the representative building of each cluster. The proposed data-driven methodology requires experts’ criteria in each step to validate the results and make them applicable, but significantly reduces the bias by automating the decision-making process. We use as case study the Dominican Republic public school infrastructure and present the results of the application of the proposed method. The method presented herein is extensible to other infrastructure portfolios, as well as to other types of hazards

    Layered double hydroxides in bioinspired nanotechnology

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    Layered Double Hydroxides (LDHs) are a relevant class of inorganic lamellar nanomaterials that have attracted significant interest in life science-related applications, due to their highly controllable synthesis and high biocompatibility. Under a general point of view, this class of materials might have played an important role for the origin of life on planet Earth, given their ability to adsorb and concentrate life-relevant molecules in sea environments. It has been speculated that the organic-mineral interactions could have permitted to organize the adsorbed molecules, leading to an increase in their local concentration and finally to the emergence of life. Inspired by nature, material scientists, engineers and chemists have started to leverage the ability of LDHs to absorb and concentrate molecules and biomolecules within life-like compartments, allowing to realize highly-efficient bioinspired platforms, usable for bioanalysis, therapeutics, sensors and bioremediation. This review aims at summarizing the latest evolution of LDHs in this research field under an unprecedented perspective, finally providing possible challenges and directions for future research

    Magnetic imaging of pearl vortices in artificially layered (Ba 0.9Nd0.1CuO2+x)m/(CaCuO 2)n systems

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    We have used scanning SQUID magnetometry to image vortices in ultrathin (Ba0.9Nd0.1CuO2+x)(m)/(CaCuO2)(n) high temperature superconductor samples, with as few as three superconducting CuO2 planes. The Pearl lengths (Lambda=2lambda(L)(2)/d, lambda(L) the London penetration depth, d the superconducting film thickness) in these samples, as determined by fits to the vortex images, agree with those by local susceptibility measurements, and can be as long as 1 mm. The in-plane penetration depths lambda(ab) inferred from the Pearl lengths are longer than many bulk cuprates with comparable critical temperatures. We speculate on the causes of the long penetration depths, and on the possibility of exploiting the unique properties of these superconductors for basic experiments

    Dissipation in ultra-thin current-carrying superconducting bridges; evidence for quantum tunneling of Pearl vortices

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    We have made current-voltage (IV) measurements of artificially layered high-TcT_c thin-film bridges. Scanning SQUID microscopy of these films provides values for the Pearl lengths Λ\Lambda that exceed the bridge width, and shows that the current distributions are uniform across the bridges. At high temperatures and high currents the voltages follow the power law VInV \propto I^n, with n=Φ02/8π2ΛkBT+1n=\Phi_0^2/8\pi^2\Lambda k_B T+1, and at high temperatures and low-currents the resistance is exponential in temperature, in good agreement with the predictions for thermally activated vortex motion. At low temperatures, the IV's are better fit by lnV\ln V linear in I2I^{-2}. This is expected if the low temperature dissipation is dominated by quantum tunneling of Pearl vortices.Comment: 5 pages, 7 fig

    Evidence of orbital reconstruction at interfaces in La0.67Sr0.33MnO3 films

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    Electronic properties of transition metal oxides at interfaces are influenced by strain, electric polarization and oxygen diffusion. Linear dichroism (LD) x-ray absorption, diffraction, transport and magnetization on thin La0.7Sr0.3MnO3 films, allow identification of a peculiar universal interface effect. We report the LD signature of preferential 3d-eg(3z2-r2) occupation at the interface, suppressing the double exchange mechanism. This surface orbital reconstruction is opposite of that favored by residual strain and independent of dipolar fields, chemical nature of the substrate and capping.Comment: 13 pages, 5 figure
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