160 research outputs found

    As narrativas como fontes de reflexões sobre práticas pedagógicas no ensino de ciências

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    Nesse artigo discute-se dados obtidos em uma pesquisa junto a professores em formação continuada sobre práticas pedagógicas interdisciplinares no ensino de ciências. A partir de quatro temas interdisciplinares tais como: Conservação da Biodiversidade, Questões hídricas, Gases de efeito estufa e Educação Ambiental, foram organizados encontros para a discussão sobre conteúdos e metodologias de ensino. Os dados foram coletados a partir de gravações em áudio, entrevistas, questionários e observação participante. Foram analisadas as narrativas dos envolvidos, o que possibilitou reflexões sobre a necessidade de discussões que esclareçam como promover a interdisciplinaridade no ambiente escolar, a importância de processos de formação docente e a necessária relação universidade-escola, pesquisas universitárias e fazer docente

    Multimodality imaging methods and systemic biomarkers in classical low-flow low-gradient aortic stenosis: Key findings for risk stratification

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    ObjectivesThe aim of the present study is to assess multimodality imaging findings according to systemic biomarkers, high-sensitivity troponin I (hsTnI) and B-type natriuretic peptide (BNP) levels, in low-flow, low-gradient aortic stenosis (LFLG-AS).BackgroundElevated levels of BNP and hsTnI have been related with poor prognosis in patients with LFLG-AS.MethodsProspective study with LFLG-AS patients that underwent hsTnI, BNP, coronary angiography, cardiac magnetic resonance (CMR) with T1 mapping, echocardiogram and dobutamine stress echocardiogram. Patients were divided into 3 groups according to BNP and hsTnI levels: Group 1 (n = 17) when BNP and hsTnI levels were below median [BNP < 1.98 fold upper reference limit (URL) and hsTnI < 1.8 fold URL]; Group 2 (n = 14) when BNP or hsTnI were higher than median; and Group 3 (n = 18) when both hsTnI and BNP were higher than median.Results49 patients included in 3 groups. Clinical characteristics (including risk scores) were similar among groups. Group 3 patients had lower valvuloarterial impedance (P = 0.03) and lower left ventricular ejection fraction (P = 0.02) by echocardiogram. CMR identified a progressive increase of right and left ventricular chamber from Group 1 to Group 3, and worsening of left ventricular ejection fraction (EF) (40 [31–47] vs. 32 [29–41] vs. 26 [19–33]%; p < 0.01) and right ventricular EF (62 [53–69] vs. 51 [35–63] vs. 30 [24–46]%; p < 0.01). Besides, there was a marked increase in myocardial fibrosis assessed by extracellular volume fraction (ECV) (28.4 [24.8–30.7] vs. 28.2 [26.9–34.5] vs. 31.8 [28.9–35.5]%; p = 0.03) and indexed ECV (iECV) (28.7 [21.2–39.1] vs. 28.8 [25.4–39.9] vs. 44.2 [36.4–51.2] ml/m2, respectively; p < 0.01) from Group 1 to Group 3.ConclusionsHigher levels of BNP and hsTnI in LFLG-AS patients are associated with worse multi-modality evidence of cardiac remodeling and fibrosis

    Large-scale and multipolar anisotropies of cosmic rays detected at the Pierre Auger Observatory with energies above 4 EeV

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    A search for ultra-high-energy photons at the Pierre Auger Observatory exploiting air-shower universality

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    The Pierre Auger Observatory is the most sensitive detector to primary photons with energies above ∼0.2 EeV. It measures extensive air showers using a hybrid technique that combines a fluorescence detector (FD) with a ground array of particle detectors (SD). The signatures of a photon-induced air shower are a larger atmospheric depth at the shower maximum (Xmax_{max}) and a steeper lateral distribution function, along with a lower number of muons with respect to the bulk of hadron-induced background. Using observables measured by the FD and SD, three photon searches in different energy bands are performed. In particular, between threshold energies of 1-10 EeV, a new analysis technique has been developed by combining the FD-based measurement of Xmax_{max} with the SD signal through a parameter related to its muon content, derived from the universality of the air showers. This technique has led to a better photon/hadron separation and, consequently, to a higher search sensitivity, resulting in a tighter upper limit than before. The outcome of this new analysis is presented here, along with previous results in the energy ranges below 1 EeV and above 10 EeV. From the data collected by the Pierre Auger Observatory in about 15 years of operation, the most stringent constraints on the fraction of photons in the cosmic flux are set over almost three decades in energy

    Study on multi-ELVES in the Pierre Auger Observatory

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    Since 2013, the four sites of the Fluorescence Detector (FD) of the Pierre Auger Observatory record ELVES with a dedicated trigger. These UV light emissions are correlated to distant lightning strikes. The length of recorded traces has been increased from 100 μs (2013), to 300 μs (2014-16), to 900 μs (2017-present), to progressively extend the observation of the light emission towards the vertical of the causative lightning and beyond. A large fraction of the observed events shows double ELVES within the time window, and, in some cases, even more complex structures are observed. The nature of the multi-ELVES is not completely understood but may be related to the different types of lightning in which they are originated. For example, it is known that Narrow Bipolar Events can produce double ELVES, and Energetic In-cloud Pulses, occurring between the main negative and upper positive charge layer of clouds, can induce double and even quadruple ELVES in the ionosphere. This report shows the seasonal and daily dependence of the time gap, amplitude ratio, and correlation between the pulse widths of the peaks in a sample of 1000+ multi-ELVES events recorded during the period 2014-20. The events have been compared with data from other satellite and ground-based sensing devices to study the correlation of their properties with lightning observables such as altitude and polarity

    Outreach activities at the Pierre Auger Observatory

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    The ultra-high-energy cosmic-ray sky above 32 EeV viewed from the Pierre Auger Observatory

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    The depth of the shower maximum of air showers measured with AERA

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    Expected performance of the AugerPrime Radio Detector

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