3,543 research outputs found

    ENSINO DE FÍSICA E AS NOVAS TECNOLOGIAS: EXPLORANDO SIMULAÇÕES, EXPERIMENTOS VIRTUAIS E O SOFTWARE GEOGEBRA

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    A Física Clássica encontra-se no estado concreto-abstrato, no qual o sujeito acrescenta voluntariamente esquemas geométricos à abstração (BACHELARD, 1996, p. 7-15). Nesse sentido, os signos visuais são recursos didáticos pertinentes para o ensino-aprendizagem da Física Clássica e, concomitantemente, se não bem diferenciados dos objetos, tornam-se potenciais obstáculos epistemológicos. Além do mais, como os sentidos e significados estão no âmago da aprendizagem significativa, o uso do registro figural em consonância com o linguístico e o simbólico (DUVAL, 2012) se faz bem empregado

    AS CONSTRUÇÕES DAS ABORDAGENS CONCEITUAIS DE CIDADES SUSTENTÁVEIS E INTELIGENTES PARA SUPERAR OS DESAFIOS DOS OBJETIVOS DO DESENVOLVIMENTO SUSTENTÁVEL

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    The recent arrangements of cities have drawn the attention of actors, who work in the triple helix, to meet the collective challenges centered on urban environments. The term sustainable and smart cities proposes two axes of studies: conceptual approaches; and the practical scope of decision-making processes of public managers. The term is also directly related to the challenges of the Sustainable Development Goals (SDGs), especially those related to sustainable cities and communities. From this perspective, this study aims to analyze the conceptual approaches of the terms sustainable cities, smart cities and sustainable and smart cities, in light of the challenges of the SDGs. This is a research, based on a systematic bibliographical review, found by an exploratory order and whose treatment was qualitative in nature. The results showed that conceptual approaches to sustainable cities do not necessarily translate into smart cities. Also, smart cities should not automatically be considered sustainable cities. Thus, the most appropriate term would be sustainable and smart cities. Based on this reflection, it is suggested to interested parties the design of more effective public policies aimed at collective challenges centered on more sustainable urban environments and with intelligent technological contributions.  Os recentes arranjos de cidades têm chamado a atenção dos atores, que atuam no tríplice hélice, para o atendimento dos desafios coletivos centrados nos ambientes urbanos. O termo cidades sustentáveis e inteligentes propõe dois eixos de estudos: as abordagens conceituais; e as abrangências práticas sobre os processos decisórios dos gestores públicos. O termo também guarda relação direta com os desafios dos Objetivos de Desenvolvimento Sustentável (ODS), especialmente, aqueles em relação às cidades e comunidades sustentáveis. Sob esta perspectiva, este estudo objetiva analisar as abordagens conceituais dos termos cidades sustentáveis, cidades inteligentes e cidades sustentáveis e inteligentes, à luz dos desafios dos ODS. Trata-se de uma pesquisa, baseada em revisão bibliográfica sistemática, de ordem exploratória, cujo tratamento teve natureza qualitativa. Os resultados apontaram que as abordagens conceituais de cidades sustentáveis não se traduzem, necessariamente, em cidades inteligentes. Igualmente, as cidades inteligentes não devem ser consideradas, de forma automática, como cidades sustentáveis. Assim, o termo mais apropriado seria cidades sustentáveis e inteligentes. A partir desta reflexão, sugere-se às partes interessadas, o desenho de políticas públicas mais eficazes voltadas aos desafios coletivos centrados nos ambientes urbanos mais sustentáveis e com os aportes tecnológicos inteligentes. &nbsp

    Ordenamento do Território e Planeamento Ambiental : investigação e prática

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    A secção Biologia é coordenada pelo Professor Universitário Armindo Rodrigues.O CIGPT fundado pelos Geógrafos Helena Calado e João Porteiro desenvolveu nas duas últimas décadas um esforço considerável na investigação e prática do Ordenamento Territoria

    A Prospective, Multicenter, Real-World Registry of Coronary Lithotripsy in Calcified Coronary Arteries

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    BACKGROUND Intravascular lithotripsy (IVL) has demonstrated effectiveness in the treatment of calcified lesions in selected patients with stable coronary disease. OBJECTIVES The authors sought to assess the performance of coronary IVL in calcified coronary lesions in a real-life, all comers, setting. METHODS The REPLICA-EPIC18 study prospectively enrolled consecutive patients treated with IVL in 26 centers in Spain. An independent core laboratory performed the angiographic analysis and event adjudication. The primary effectiveness endpoint assessed procedural success (successful IVL delivery, final diameter stenosis <20%, and absence of in- hospital major adverse cardiovascular events [MACE]). The primary safety endpoint measured freedom from MACE at 30 days. A predefined substudy compared outcomes between acute coronary syndrome (ACS) and chronic coronary syndrome (CCS) patients. RESULTS A total of 426 patients (456 lesions) were included, 63% of the patients presenting with ACS. IVL delivery was successful in 99% of cases. Before IVL, 49% of lesions were considered undilatable. The primary effectiveness endpoint was achieved in 66% of patients, with similar rates among CCS patients (68%) and ACS patients (65%). Likewise, there were no significant differences in angiographic success after IVL between CCS and ACS patients. The rate of MACE at 30 days (primary safety endpoint) was 3% (1% in CCS and 5% in ACS patients [P = 0.073]). CONCLUSIONS Coronary IVL proved to be a feasible and safe procedure in a real-life setting, effectively facilitating stent implantation in severely calcified lesions. Patients with ACS on admission showed similar angiographic success rates but showed a trend toward higher 30-day MACE compared with patients with CCS. (REPLICA-EPIC18 study [Registry of Coronary Lithotripsy in Spain]; NCT04298307) (c) 2024 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

    Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

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    The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

    Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

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    We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

    Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

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    A measurement of the cosmic-ray spectrum for energies exceeding 4×10184{\times}10^{18} eV is presented, which is based on the analysis of showers with zenith angles greater than 6060^{\circ} detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above 5.3×10185.3{\times}10^{18} eV, the "ankle", the flux can be described by a power law EγE^{-\gamma} with index γ=2.70±0.02(stat)±0.1(sys)\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)} followed by a smooth suppression region. For the energy (EsE_\text{s}) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find Es=(5.12±0.25(stat)1.2+1.0(sys))×1019E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19} eV.Comment: Replaced with published version. Added journal reference and DO

    Basin-wide variation in tree hydraulic safety margins predicts the carbon balance of Amazon forests

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    ests face increasing climate risk, yet our ability to predict their response to climate change is limited by poor understanding of their resistance to water stress. Although xylem embolism resistance thresholds (for example, Ψ50) and hydraulic safety margins (for example, HSM50) are important predictors of drought-induced mortality risk, little is known about how these vary across Earth’s largest tropical forest. Here, we present a pan-Amazon, fully standardized hydraulic traits dataset and use it to assess regional variation in drought sensitivity and hydraulic trait ability to predict species distributions and long-term forest biomass accumulation. Parameters Ψ50 and HSM50 vary markedly across the Amazon and are related to average long-term rainfall characteristics. Both Ψ50 and HSM50 influence the biogeographical distribution of Amazon tree species. However, HSM50 was the only significant predictor of observed decadal-scale changes in forest biomass. Old-growth forests with wide HSM50 are gaining more biomass than are low HSM50 forests. We propose that this may be associated with a growth–mortality trade-off whereby trees in forests consisting of fast-growing species take greater hydraulic risks and face greater mortality risk. Moreover, in regions of more pronounced climatic change, we find evidence that forests are losing biomass, suggesting that species in these regions may be operating beyond their hydraulic limits. Continued climate change is likely to further reduce HSM50 in the Amazon, with strong implications for the Amazon carbon sink

    Novel genes and sex differences in COVID-19 severity

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    [EN] Here, we describe the results of a genome-wide study conducted in 11 939 coronavirus disease 2019 (COVID-19) positive cases with an extensive clinical information that were recruited from 34 hospitals across Spain (SCOURGE consortium). In sex-disaggregated genome-wide association studies for COVID-19 hospitalization, genome-wide significance (P < 5 × 10−8) was crossed for variants in 3p21.31 and 21q22.11 loci only among males (P = 1.3 × 10−22 and P = 8.1 × 10−12, respectively), and for variants in 9q21.32 near TLE1 only among females (P = 4.4 × 10−8). In a second phase, results were combined with an independent Spanish cohort (1598 COVID-19 cases and 1068 population controls), revealing in the overall analysis two novel risk loci in 9p13.3 and 19q13.12, with fine-mapping prioritized variants functionally associated with AQP3 (P = 2.7 × 10−8) and ARHGAP33 (P = 1.3 × 10−8), respectively. The meta-analysis of both phases with four European studies stratified by sex from the Host Genetics Initiative (HGI) confirmed the association of the 3p21.31 and 21q22.11 loci predominantly in males and replicated a recently reported variant in 11p13 (ELF5, P = 4.1 × 10−8). Six of the COVID-19 HGI discovered loci were replicated and an HGI-based genetic risk score predicted the severity strata in SCOURGE. We also found more SNP-heritability and larger heritability differences by age (<60 or ≥60 years) among males than among females. Parallel genome-wide screening of inbreeding depression in SCOURGE also showed an effect of homozygosity in COVID-19 hospitalization and severity and this effect was stronger among older males. In summary, new candidate genes for COVID-19 severity and evidence supporting genetic disparities among sexes are provided.S
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