1,523 research outputs found

    Shape Optimization by Pursuing Diffeomorphisms

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    We consider PDE constrained shape optimization in the framework of finite element discretization of the underlying boundary value problem. We present an algorithm tailored to preserve and exploit the approximation properties of the finite element method, and that allows for arbitrarily high resolution of shapes. It employs (i) B-spline based representations of the deformation diffeomorphism, and (ii) superconvergent domain integral expressions for the shape gradient. We provide numerical evidence of the performance of this method both on prototypical well-posed and ill-posed shape optimization problems

    Nitrogen-Doped Zinc Oxide for Photo-Driven Molecular Hydrogen Production

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    Due to its thermal stability, conductivity, high exciton binding energy and high electron mobility, zinc oxide is one of the most studied semiconductors in the field of photocatalysis. However, the wide bandgap requires the use of UV photons to harness its potential. A convenient way to appease such a limitation is the doping of the lattice with foreign atoms which, in turn, introduce localized states (defects) within the bandgap. Such localized states make the material optically active in the visible range and reduce the energy required to initiate photo-driven charge separation events. In this work, we employed a green synthetic procedure to achieve a high level of doping and have demonstrated how the thermal treatment during synthesis is crucial to select specific the microscopic (molecular) nature of the defect and, ultimately, the type of chemistry (reduction versus oxidation) that the material is able to perform. We found that low-temperature treatments produce material with higher efficiency in the water photosplitting reaction. This constitutes a further step in the establishment of N-doped ZnO as a photocatalyst for artificial photosynthesis

    Association between neutropenia and response to ramucirumab and paclitaxel in patients with metastatic gastric cancer

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    PURPOSE: The aim of this study was to evaluate if the occurrence of neutropenia is correlated with response to ramucirumab plus paclitaxel for metastatic gastric cancer.METHODS: This is a retrospective study of patients treated with ramucirumab plus paclitaxel.RESULTS: Fifty-three patients were evaluated. Among these, 10 patients (26.5%) developed grade ≥3 neutropenia. Patients with grade ≥3 neutropenia reported a progression-free survival of 6.6 months (95% confidence interval 3.3-8.4) and overall survival of 11 months (95% confidence interval 5.9-13.1) vs. 4.4 months (95% confidence interval 3.9-5.2) and 8.7 months (95% confidence interval 7.8-10.1) respectively in patients' group with lower grade events.CONCLUSION: Our analysis seems to suggest that the occurrence of neutropenia predicts response to treatment with ramucirumab and paclitaxel.</p

    Growing and Eating Food during the COVID-19 Pandemic:Farmers’ Perspectives on Local Food System Resilience to Shocks in Southern Africa and Indonesia

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    The COVID-19 outbreak forced governments to make decisions that had adverse effects on local food systems and supply chains. As a result, many small-scale food producers faced difficulties growing, harvesting, and selling their goods. This participatory research examines local small-scale farmers’ challenges as farmers but also as consumers and their coping strategies during the month of April and one week in June 2020. The study was initiated and conceptualized in collaboration with small-scale farmer members of an existing research network in selected urban and rural areas in South Africa, Mozambique, Zimbabwe, and Indonesia. Participants co-designed the research, collected and uploaded data through digital survey tools, and contributed to data analysis and interpretation. A common observation across regions is that the measures imposed in response to COVID-19 highlighted and partly exacerbated existing socio-economic inequalities among food system actors. Strict lockdowns in Cape Town, South Africa, and Masvingo, Zimbabwe, significantly restricted the production capacity of small-scale farmers in the informal economy and created more foodinsecurityforthem. InMaputo,Mozambique,andTorajaandJava,Indonesia,localfoodsystems continued to operate and were even strengthened by higher social capital and adaptive capacities

    Observar y reordenar el territorio para el desarrollo sustentable : Los observatorios como herramientas de gestión territorial

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    PosterEl objetivo principal fue fortalecer las capacidades conceptuales y metodológicas de los gobiernos locales, generando un espacio de reflexión e intercambio colectivo sobre la factibilidad de desarrollar e implementar un proceso de ordenamiento territorial y de Observatorios Territores para la interfaz urbano-rural. Para alcanzar los objetivos propuestos, el equipo gestor, acordó la realización de un Seminario taller destinado a funcionarios municipales de las distintas áreas, miembros del Consejo Local Asesor y profesionales del INTA. Los grupos de trabajo identificaron y priorizaron procesos de transformación territoriales críticos que afectan el desarrollo y la sustentabilidad de los respectivos municipios.EEA San PedroFil: Delprino, María Rosa. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Pedro; ArgentinaFil: Mitidieri, Mariel Silvina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Pedro; ArgentinaFil: D´Angelcola, María Elena. Instituto Nacional de Tecnología Agropecuaria (INTA). Gerencia de Monitoreo y Evaluación; ArgentinaFil: Vitale Gutierrez, Javier Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Centro Regional Mendoza-San Juan; ArgentinaFil: Pérez, Martín Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Hansen, Laura. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Pedro; ArgentinaFil: Paganini, Adolfo Hernán. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Pedro. Agencia de Extensión Rural Zárate; ArgentinaFil: Caamaño, Adolfo. Consejo Local Asesor EEA San Pedro; ArgentinaFil: Constantino, Armando. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Pedro; ArgentinaFil: Ros, Patricio Guillermo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Pedro. Agencia de Extensión Rural San Nicolás; ArgentinaFil: Fortunato, Nicolás. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Pedro. Agencia de Extensión Rural San Pedro; ArgentinaFil: Pagliaricci, Leandro Osvaldo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Pedro; ArgentinaFil: Piola, Mariana. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Pedro; Argentin

    Energy Resolution Performance of the CMS Electromagnetic Calorimeter

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    The energy resolution performance of the CMS lead tungstate crystal electromagnetic calorimeter is presented. Measurements were made with an electron beam using a fully equipped supermodule of the calorimeter barrel. Results are given both for electrons incident on the centre of crystals and for electrons distributed uniformly over the calorimeter surface. The electron energy is reconstructed in matrices of 3 times 3 or 5 times 5 crystals centred on the crystal containing the maximum energy. Corrections for variations in the shower containment are applied in the case of uniform incidence. The resolution measured is consistent with the design goals

    A Roadmap for HEP Software and Computing R&D for the 2020s

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    Particle physics has an ambitious and broad experimental programme for the coming decades. This programme requires large investments in detector hardware, either to build new facilities and experiments, or to upgrade existing ones. Similarly, it requires commensurate investment in the R&D of software to acquire, manage, process, and analyse the shear amounts of data to be recorded. In planning for the HL-LHC in particular, it is critical that all of the collaborating stakeholders agree on the software goals and priorities, and that the efforts complement each other. In this spirit, this white paper describes the R&D activities required to prepare for this software upgrade.Peer reviewe

    Impacts of the Tropical Pacific/Indian Oceans on the Seasonal Cycle of the West African Monsoon

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    The current consensus is that drought has developed in the Sahel during the second half of the twentieth century as a result of remote effects of oceanic anomalies amplified by local land–atmosphere interactions. This paper focuses on the impacts of oceanic anomalies upon West African climate and specifically aims to identify those from SST anomalies in the Pacific/Indian Oceans during spring and summer seasons, when they were significant. Idealized sensitivity experiments are performed with four atmospheric general circulation models (AGCMs). The prescribed SST patterns used in the AGCMs are based on the leading mode of covariability between SST anomalies over the Pacific/Indian Oceans and summer rainfall over West Africa. The results show that such oceanic anomalies in the Pacific/Indian Ocean lead to a northward shift of an anomalous dry belt from the Gulf of Guinea to the Sahel as the season advances. In the Sahel, the magnitude of rainfall anomalies is comparable to that obtained by other authors using SST anomalies confined to the proximity of the Atlantic Ocean. The mechanism connecting the Pacific/Indian SST anomalies with West African rainfall has a strong seasonal cycle. In spring (May and June), anomalous subsidence develops over both the Maritime Continent and the equatorial Atlantic in response to the enhanced equatorial heating. Precipitation increases over continental West Africa in association with stronger zonal convergence of moisture. In addition, precipitation decreases over the Gulf of Guinea. During the monsoon peak (July and August), the SST anomalies move westward over the equatorial Pacific and the two regions where subsidence occurred earlier in the seasons merge over West Africa. The monsoon weakens and rainfall decreases over the Sahel, especially in August.Peer reviewe

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio
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