81 research outputs found

    Fake news, immigration and opinion polarisation [winner - festival prize]

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    Nowadays, it is hard to venture online without coming across a heated discussion over “Fake News”; as a result, people are finding hard times moving through an entirely new distorted era of misinformation. In this paper, we investigate the effect of fake news on people’s opinion polarisation. Acknowledgements: Diego Rossinell

    Identification of diversions in spent PWR fuel assemblies by PDET signatures using Artificial Neural Networks (ANNs)

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    Spent nuclear fuel represents the majority of materials placed under nuclear safeguards today and it requires to be inspected and verified regularly to promptly detect any illegal diversion. Research is ongoing both on the development of non-destructive assay instruments and methods for data analysis in order to enhance the verification accuracy and reduce the inspection time. In this paper, two models based on Artificial Neural Networks (ANNs) are studied to process measurements from the Partial Defect Tester (PDET) in spent fuel assemblies of Pressurized Water Reactors (PWRs), and thus to identify at different levels of detail whether nuclear fuel has been replaced with dummy pins or not. The first model provides an estimation of the percentage of replaced fuel pins within the inspected fuel assembly, while the second model determines the exact configuration of the replaced fuel pins. The two models are trained and tested using a dataset of Monte-Carlo simulated PDET responses for intact spent PWR fuel assemblies and a variety of hypothetical diversion scenarios. The first model classifies fuel assemblies according to the percentage of diverted fuel with a high accuracy (96.5%). The second model reconstructs the correct configuration for 57.5% of the fuel assemblies available in the dataset and still retrieves meaningful information of the diversion pattern in many of the misclassified cases

    Conceptual design and initial evaluation of a neutron flux gradient detector

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    Identification of the position of a localized neutron source, or that of local inhomogeneities in a multiplying or scattering medium (such as the presence of small, strong absorbers) is possible by measurement of the neutron flux in several spatial points, and applying an unfolding procedure. It was suggested earlier, and it was confirmed by both simulations and pilot measurements, that if, in addition to the usually measured scalar (angularly integrated) flux, the neutron current vector or its diffusion approximation (the flux gradient vector) is also considered, the efficiency and accuracy of the unfolding procedure is significantly enhanced. Therefore, in support of a recently started project, whose goal is to detect missing (replaced) fuel pins in a spent fuel assembly by non-intrusive methods, this idea is followed up. The development and use of a dedicated neutron detector for within-assembly measurements of the neutron scalar flux and its gradient are planned. The detector design is based on four small, fiber-mounted scintillation detector tips, arranged in a rectangular pattern. Such a detector is capable of measuring the two Cartesian components of the flux gradient vector in the horizontal plane. This paper presents an initial evaluation of the detector design, through Monte Carlo simulations in a hypothetical scenario

    Conversion of Lignin to Chemical Intermediates:a Study of Pyrolysis of Kraft Lignin

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    Experiments of pyrolysis of commercial Kraft lignin have been realized in the 250-550 °C range. Product analyses have been performed by FTIR, GC-MS, EDX analyses. The main goal of the work is to optimize the experiments in terms of liquid yield, reduction of oxygen content in the resulting biochar, and removal of sulfur, found mainly in the gas phase. It has been concluded that the amount of the starting lignin charged in the reactor must be limited to be fully positioned in the heating chamber also during high temperature treatment. Sulfur may be partially removed in the gas phase as H2S and CH3SH mainly, by a pre-treatment at 250 °C. The maximum amount of liquid product, mainly constituted by methoxy- and alkyl-methoxy-phenols, and the maximum solid deoxygenation are both obtained at 550 °C

    Brain Metastases from Ovarian Cancer: Current Evidence in Diagnosis, Treatment, and Prognosis

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    With this review, we provide the state of the art concerning brain metastases (BMs) from ovarian cancer (OC), a rare condition. Clinical, pathological, and molecular features, treatment options, and future perspectives are comprehensively discussed. Overall, a diagnosis of high-grade serous OC and an advanced disease stage are common features among patients who develop brain metastases. BRCA1 and BRCA2 gene mutations, as well as the expression of androgen receptors in the primary tumor, are emerging risk and prognostic factors which could allow one to identify categories of patients at greater risk of BMs, who could benefit from a tailored follow-up. Based on present data, a multidisciplinary approach combining surgery, radiotherapy, and chemotherapy seem to be the best approach for patients with good performance status, although the median overall survival (<1 year) remains largely disappointing. Hopefully, novel therapeutic avenues are being explored, like PARP inhibitors and immunotherapy, based on our improved knowledge regarding tumor biology, but further investigation is warranted

    Prenatal Biochemical and Ultrasound Markers in COVID-19 Pregnant Patients: A Prospective Case-Control Study

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    This prospective observational study aimed to evaluate whether women with SARS-CoV-2 infection during the first trimester of pregnancy are at higher risk of noninvasive prenatal screening test alterations and/or of congenital fetal anomalies at the second-trimester fetal anatomy scan. Maternal symptoms were secondly investigated. The study was carried out on 12-week pregnant women admitted for noninvasive prenatal testing (16 April and 22 June 2020). The cohort had seromolecular tests for SARS-CoV-2, after which they were divided into a positive case group and a negative control group. Both groups had 20-week ultrasound screening. Seventeen out of the 164 women tested positive for SARS-CoV-2 (10.3%). There were no significant differences in mean nuchal translucency thickness or biochemical markers (pregnancy-associated plasma protein A, alpha-fetoprotein, human chorionic gonadotropin, unconjugated estriol) between cases and controls (p = 0.77, 0.63, 0.30, 0.40, 0.28) or in the fetal incidence of structural anomalies at the second-trimester fetal anatomy scan (p = 0.21). No pneumonia or hospital admission due to COVID-19-related symptoms were observed. Asymptomatic or mildly symptomatic SARS-CoV-2 infection during the first trimester of pregnancy did not predispose affected women to more fetal anomalies than unaffected women. COVID-19 had a favorable maternal course at the beginning of pregnancy in our healthy cohort

    More Bucks for the Bang: New Space Solutions, Impact Tourism and one Unique Science & Engineering Opportunity at T-6 Months and Counting

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    For now, the Planetary Defense Conference Exercise 2021's incoming fictitious(!) asteroid, 2021 PDC, seems headed for impact on October 20th, 2021, exactly 6 months after its discovery. Today (April 26th, 2021), the impact probability is 5%, in a steep rise from 1 in 2500 upon discovery six days ago. We all know how these things end. Or do we? Unless somebody kicked off another headline-grabbing media scare or wants to keep civil defense very idle very soon, chances are that it will hit (note: this is an exercise!). Taking stock, it is barely 6 months to impact, a steadily rising likelihood that it will actually happen, and a huge uncertainty of possible impact energies: First estimates range from 1.2 MtTNT to 13 GtTNT, and this is not even the worst-worst case: a 700 m diameter massive NiFe asteroid (covered by a thin veneer of Ryugu-black rubble to match size and brightness) would come in at 70 GtTNT. In down to Earth terms, this could be all between smashing fireworks over some remote area of the globe and a 7.5 km crater downtown somewhere. Considering the deliberate and sedate ways of development of interplanetary missions it seems we can only stand and stare until we know well enough where to tell people to pack up all that can be moved at all and save themselves. But then, it could just as well be a smaller bright rock. The best estimate is 120 m diameter from optical observation alone, by 13% standard albedo. NASA's upcoming DART mission to binary asteroid (65803) Didymos is designed to hit such a small target, its moonlet Dimorphos. The Deep Impact mission's impactor in 2005 successfully guided itself to the brightest spot on comet 9P/Tempel 1, a relatively small feature on the 6 km nucleus. And 'space' has changed: By the end of this decade, one satellite communication network plans to have launched over 11000 satellites at a pace of 60 per launch every other week. This level of series production is comparable in numbers to the most prolific commercial airliners. Launch vehicle production has not simply increased correspondingly - they can be reused, although in a trade for performance. Optical and radio astronomy as well as planetary radar have made great strides in the past decade, and so has the design and production capability for everyday 'high-tech' products. 60 years ago, spaceflight was invented from scratch within two years, and there are recent examples of fastpaced space projects as well as a drive towards 'responsive space'. It seems it is not quite yet time to abandon all hope. We present what could be done and what is too close to call once thinking is shoved out of the box by a clear and present danger, to show where a little more preparedness or routine would come in handy - or become decisive. And if we fail, let's stand and stare safely and well instrumented anywhere on Earth together in the greatest adventure of science

    The European Forest Information System, an Internet Based Interface between Information Providers and the User Community.

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    Abstract not availableJRC.H-Institute for environment and sustainability (Ispra

    Seleção de cor em dentisteria. Confiabilidade da correspondência de cores visual e instrumental

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    Introdução: Na prática clínica diária, a utilização de instrumentos colorimétricos oferece a possibilidade de gerir aspetos de cor facilitando a escolha, comunicação, reprodução e controlo da cor nas restaurações (1). Existem duas abordagens possíveis para a escolha da cor: o método visual e o método tecnológico instrumental. Objetivo: O objetivo desta revisão sistemática integrativa é analisar e comparar a confiabilidade da correspondência de cores visual e instrumental e a taxa de concordância dos diferentes métodos de medição de cor dental. Materiais e métodos: Foi realizada uma pesquisa bibliográfica na base de dados PubMed (via National Library of Medicine). Foi utilizada a estratégia PICO e foram redigidos critérios de inclusão e de exclusão para escolher os artigos úteis para o presente estudo. Resultados: Foram analisados quinze artigos caso-controlo onde dois estudos tiveram uma amostra em vitro e treze em vivo. Nove artigos analisaram o método visual e catorze instrumentais. Discussão: Foi relatada uma relevância altamente significativa na confiabilidade no espectrofotómetro e no scanner intraoral comparado com a escala visual de cor. Conclusão: Entre os métodos instrumentais o scanner intraoral 3Shape Trios e o espetrofotómetro (EFT) VITA Easyshade exibiram excelente confiabilidade e correspondência de cores significativamente melhor comparados com outros modelos de avaliação visual e instrumental.Introduction: In daily clinical practice, the use of colorimetric instruments offers the possibility of managing color aspects, facilitating choice, communication, reproduction and control of color in restorations(1). There are two possible approaches to color choice: the visual method and the instrumental technological method. Objective: The aim of this integrative systematic review is to analyze and compare the reliability of visual and instrumental color matching and the concordance rate of different methods of measuring dental color. Materials and methods: A bibliographic search was carried out in the PubMed database (via the National Library of Medicine). The PICO strategy was used and inclusion and exclusion criteria were written to choose useful articles for the present study. Results: Fifteen case-control articles were analyzed, where two studies had a sample in vitro and thirteen in vivo. Nine articles analyzed the visual method and fourteen instrumental ones. Discussion: A highly significant relevance in the reliability of the spectrophotometer and the intraoral scanner compared to the visual color scale was reported. Conclusion: Among the instrumental methods, the 3Shape Trios intraoral scanner and the VITA Easyshade spectrophotometer exhibited excellent reliability and significantly better color matching compared to other visual and instrumental evaluation models
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