Disentangling the sources of ionizing radiation in superconducting qubits

Radioactivity was recently discovered as a source of decoherence and correlated errors for the real-world implementation of superconducting quantum processors. In this work, we measure levels of radioactivity present in a typical laboratory environment (from muons, neutrons, and gamma's emitted by naturally occurring radioactive isotopes) and in the most commonly used materials for the assembly and operation of state-of-the-art superconducting qubits. We develop a GEANT-4 based simulation to predict the rate of impacts and the amount of energy released in a qubit chip from each of the mentioned sources. We finally propose mitigation strategies for the operation of next-generation qubits in a radio-pure environment

Disentangling the sources of ionizing radiation in superconducting qubits

Radioactivity was recently discovered as a source of decoherence and correlated errors for the real-world implementation of superconducting quantum processors. In this work, we measure levels of radioactivity present in a typical laboratory environment (from muons, neutrons, and γ-rays emitted by naturally occurring radioactive isotopes) and in the most commonly used materials for the assembly and operation of state-of-the-art superconducting qubits. We present a GEANT-4 based simulation to predict the rate of impacts and the amount of energy released in a qubit chip from each of the mentioned sources. We finally propose mitigation strategies for the operation of next-generation qubits in a radio-pure environment

Pedagogical benefits of fieldwork of the students at the Faculty of Geography in the light of the Bologna Process

Students' opinion and assessment of the quality of teaching presents an important segment of the evaluation of the quality of teaching at university level in accordance with the principles of the Bologna Process. In this study, we have examined opinion of students at the Faculty of Geography, University of Belgrade on the pedagogical benefits of fieldwork, which presents an important determinant of geographers' education. A total of 215 students evaluated pedagogical benefits of fieldwork in relation to didactic-methodical aspects such as: immediate contact with objects of knowledge; interdisciplinary study of a problem; application of various methods of teaching; enhancement of motivation for learning; improvement of social relations, and development of skills necessary for fieldwork. Research results indicate that students recognize and positively evaluate benefits of fieldwork. Final-year students as well as students who had more days of fieldwork evaluate benefits of fieldwork in a more positive way. Research results indicate the need to improve the quality of fieldwork and increase its share in the curriculum of the Faculty of Geography in accordance with the constructivist paradigm in education, which places a student at the centre of educational process, and fundamental principles of the Bologna Process

Estabilidade de farinha de batata-doce biofortificada Stability of biofortified sweet potato flour

A farinha de batata-doce, quando elaborada a partir de raízes com alto teor de &#946;-caroteno, é fonte de pró-vitamina A, que apresenta efeitos benéficos na saúde humana. Visando contribuir com o suprimento de vitamina A na alimentação de populações carentes, a EMBRAPA tem selecionado e melhorado culturas via biofortificação, como da batata-doce, e pesquisado o desenvolvimento de produtos com esta matéria-prima biofortificada. Complementando esses desenvolvimentos, o objetivo deste estudo foi comparar o efeito do tipo de embalagem e do sistema de acondicionamento do produto na preservação de carotenoides de farinha de batata-doce biofortificada. A farinha foi acondicionada com e sem vácuo, em embalagens com diferentes barreiras ao oxigênio, vapor d'água e luz (PET/Al/PEBD, PETmet/PEBD, PEBD/PA/PEBD e PEBD) e estocada a 25 °C/75%UR com e sem exposição à luz por um ano. Perdas de 50% de carotenoides totais e &#946;-caroteno ocorreram na farinha em PETmet/PEBD e PEBD sem vácuo, aos 50 dias de estocagem, em razão do teor de oxigênio residual presente no espaço livre e também da alta permeação de oxigênio pelo material no caso do PEBD, no qual a composição do ar foi mantida durante todo o estudo. Perdas de 50% de carotenoides ocorreram aos 90 dias com ou sem exposição à luz no produto em PEBD/PA/PEBD com vácuo, indicando que a reação de oxidação de carotenoides sob luz se restringe apenas à farinha em contato com a superfície da embalagem. Sob vácuo e em PETmet/PEBD, os teores de carotenoides na farinha diminuíram ligeiramente e foram mantidos no PET/Al/PEBD, até 360 dias de estocagem. Os resultados indicaram que a redução do teor de oxigênio no espaço livre da embalagem por meio da aplicação de vácuo aliada ao uso de materiais de embalagem com barreira ao oxigênio da ordem de grandeza de PET com metalização barreira são os fatores mais importantes na preservação de carotenoides em farinha de batata-doce biofortificada.<br>Sweet potato flour, when made from roots with high &#946;-carotene contents, is a source of pro-vitamin A, presenting beneficial effects for human health. Thus aiming at contributing to the supply of vitamin A in the diet of more needy populations, EMBRAPA has selected and improved some crops via biofortification, such as the sweet potato, and developed products with the biofortified raw material. Complementing these developments, the purpose of this study was to correlate the effect of the type of package and packaging system on the product, in the preservation of the carotenoids in the biofortified sweet potato flour. The flour was packed with and without vacuum in packs with different oxygen, water vapour and light barriers (PET/Al/LDPE, PETmet/LDPE, LDPE/PA/LDPE and LDPE) and stored at 25 °C/75%RH with and without exposure to light. Losses of 50% of the total carotenoids and &#946;-carotene occurred in the flour packed in PETmet/LDPE and LDPE without vacuum after 50 days of storage, due to the residual oxygen in the headspace and the high oxygen transmission rate in the case of LDPE, where the internal atmosphere showed the composition of air throughout the study. Losses of 50% carotenoids occurred after 90 days with and without exposure to light in the flour packed in LDPE/PA/LDPE with vacuum, indicating that in the presence of light, the carotenoid oxidation reaction is restricted to flour in contact with the surface of the package. Under vacuum and packed in PETmet/LDPE, the carotenoid contents of the flour reduced slightly, but were preserved for up to 360 days of storage when packed in PET/Al/LDPE. The results indicate that the key factors to preserve carotenoids in biofortified sweet potato flour are the reduction of the oxygen level in the headspace of the package by the application of vacuum, together with the use of packaging materials with an oxygen barrier as good as that of PET with a metalized barrier

A multicenter RCT of Zephyr® Endobronchial Valve treatment in heterogeneous emphysema (LIBERATE)

RATIONALE: This is the first multicenter RCT to evaluate effectiveness and safety of Zephyr® Endobronchial Valve EBV® out to 12-months. OBJECTIVES: To evaluate the effectiveness and safety of Zephyr EBV in heterogeneous emphysema with little to no collateral ventilation (CV) in the treated lobe. METHODS: Subjects were enrolled with a 2:1 randomization (EBV: Standard-of-Care (SoC)) at 24 sites. Primary outcome at 12-months was the ΔEBV-SoC of subjects with a post-bronchodilator FEV1 improvement from baseline of ≥15%. Secondary endpoints included absolute changes in post-BD FEV1, Six-Minute Walk Distance (6MWD), and St. George's Respiratory Questionnaire (SGRQ) scores. RESULTS: 190 subjects, 128 EBV and 62 SoC were randomized. At 12-months, 47.7% EBV and 16.8% SoC subjects had a ΔFEV1 ≥15% (p<0.001). ΔEBV-SoC at 12-months was statistically and clinically significant: for FEV1 (L), 0.106L (p<0.001); 6MWD, +39.31m (p=0.002); and SGRQ, -7.05 points (p=0.004). Significant ΔEBV-SoC were also observed in hyperinflation (RV, -522ml; p<0.001), mMRC, -0.8 points (p<0.001), and the BODE Index (-1.2 points). Pneumothorax was the most common serious adverse event in the Treatment Period (procedure to 45 days), in 34/128 (26.6%) of EBV subjects. Four deaths occurred in the EBV group during this phase, and one each in the EBV and SoC groups between 46 days and 12-months. CONCLUSIONS: Zephyr EBV provides clinically meaningful benefits in lung function, exercise tolerance, dyspnea and quality of life out to at least 12-months, with an acceptable safety profile in patients with little or no collateral ventilation in the target lobe. Clinical trial registration available at www.clinicaltrials.gov, ID NCT01796392