Twisting gauged non-linear sigma-models

We consider gauged sigma-models from a Riemann surface into a Kaehler and hamiltonian G-manifold X. The supersymmetric N=2 theory can always be twisted to produce a gauged A-model. This model localizes to the moduli space of solutions of the vortex equations and computes the Hamiltonian Gromov-Witten invariants. When the target is equivariantly Calabi-Yau, i.e. when its first G-equivariant Chern class vanishes, the supersymmetric theory can also be twisted into a gauged B-model. This model localizes to the Kaehler quotient X//G.Comment: 33 pages; v2: small additions, published versio

COVID-19 Vaccines and Atrial Fibrillation: Analysis of the Post-Marketing Pharmacovigilance European Database

Atrial fibrillation (AF) has been described in COVID-19 patients. Recently, some case reports and US pharmacovigilance analyses described AF onset as a rare adverse event following COVID-19 vaccination. The possible correlation is unclear. We systematically analyzed the reports of AF related to COVID-19 vaccines collected in the European pharmacovigilance database, EudraVigilance (EV), from 2020 to November 2022. We carried out descriptive and disproportionality analyses. Moreover, we performed a sensitivity analysis, excluding the reports describing other possible alternative AF causes (pericarditis, myocarditis, COVID-19, or other drugs that may cause/exacerbate AF). Overall, we retrieved 6226 reports, which represented only 0.3% of all those related to COVID-19 vaccines collected in EV during our study period. AF reports mainly referred to adults (in particular, >65 years old), with an equal distribution in sex. Reports were mainly related to tozinameran (54.04%), elasomeran (28.3%), and ChAdOx1-S (14.32%). The reported AF required patient hospitalization in 35% of cases and resulted in a life-threatening condition in 10% of cases. The AF duration (when reported) was highly variable, but the majority of the events had a short duration (moda = 24 h). Although an increased frequency of AF reporting with mRNA vaccines emerges from our study, other investigations are required to investigate the possible correlation between COVID-19 vaccination and the rare AF occurrence

Determinação das temperaturas e seqüências de transformação de fases por dilatometria em aços baixo carbono contendo Mn e Si e microadição de Nb submetidos a diferentes ciclos térmicos

Os aços bifásicos (A.H.S.S., Advanced High Strength Steels) têm características interessantes para a indústria automotiva, devido a eles apresentarem a combinação de resistência, dutilidade e conformabilidade que permite a redução de peso com manutenção da resistência. Os aços de baixo carbono com estrutura bifásica contendo ferrita em conjunto com a presença de bainita ou martensita apresentam combinação de resistência e ductilidade mais elevadas que os ferríticos-perlíticos. A obtenção destas microestruturas nestes aços advém do resfriamento controlado, conferindo elevada resistência mecânica e boa tenacidade a estes aços. Para execução deste trabalho foram elaboradas em escala piloto três ligas de baixo carbono e combinações dos teores de Si e Mn, e microligadas ao Nb. As temperaturas e as seqüências de transformação de fases foram determinadas por meio de ensaios experimentais de dilatometria a partir de ciclos térmicos com temperatura de encharque de 1000ºC por 300 s e distintas taxas de aquecimento (1 e 10ºC/s) e de resfriamento (1, 10 e 50ºC/s). Com uso do microscópio óptico e do microscópio eletrônico de varredura foi possível estudar a correlação entre a composição química e a evolução microestrutural com base no andamento das curvas de dilatometria durante os distintos ciclos térmicos, para assim avaliar o seu efeito sob as temperaturas e as seqüências de transformação de fases

Gauging the Poisson sigma model

We show how to carry out the gauging of the Poisson sigma model in an AKSZ inspired formulation by coupling it to the a generalization of the Weil model worked out in ref. arXiv:0706.1289 [hep-th]. We call the resulting gauged field theory, Poisson--Weil sigma model. We study the BV cohomology of the model and show its relation to Hamiltonian basic and equivariant Poisson cohomology. As an application, we carry out the gauge fixing of the pure Weil model and of the Poisson--Weil model. In the first case, we obtain the 2--dimensional version of Donaldson--Witten topological gauge theory, describing the moduli space of flat connections on a closed surface. In the second case, we recover the gauged A topological sigma model worked out by Baptista describing the moduli space of solutions of the so--called vortex equations.Comment: 49 pages, no figures. Typos corrected. Presentation improve

Efeito da microadição de Nb nas temperaturas de transformação de fase de aços de baixo carbono contendo Mn após a laminação a quente em escala piloto

As chapas de aços avançados de alta resistência (A.H.S.S., Advanced High Strength Steels) vêm sendo desenvolvidas há mais de quarenta anos. Eles são uma das principais respostas da siderurgia mundial aos desafios impostos por seus clientes em sua busca por maior competitividade e atendimento às restrições ao consumo de energia e preservação do meio ambiente, como por exemplo a indústria automobilística. A adição de Nb nesta classe de aço possibilita a obtenção de materiais de mais alta resistência mecânica e manutenção da ductilidade pela microestrutura final refinada produzida. Para execução deste trabalho foram laminados dois aços baixo carbono em escala piloto com teores de carbono na faixa de 0,125%, manganês de 0,8% e microligado ao Nb (0,033%), onde os mesmos foram submetidos a 8 passes de redução. De modo a proceder a caracterização destes materiais foram executados ensaios de dilatometria (dilatometro de têmpera, Adhamel - DT1000) na condição como recebida dos materiais, e um monitoramento do processo de laminação a quente em escala piloto com base nas cargas e reduções impostos em cada passe, e perfil de temperatura em todo processamento. Dessa forma, puderam ser avaliadas as mudanças nas temperaturas de transformação (Ar3 e Ar1) sob efeito da composição química e evolução microestrutural da austenita com base em fenômenos como endurecimento por solução sólida, encruamento, precipitação e redução do tamanho de grão

Data mining in HIV-AIDS surveillance system: application to portuguese data

The Human Immunodeficiency Virus (HIV) is an infectious agent that attacks the immune system cells. Without a strong immune system, the body becomes very susceptible to serious life threatening opportunistic diseases. In spite of the great progresses on medication and prevention over the last years, HIV infection continues to be a major global public health issue, having claimed more than 36 million lives over the last 35 years since the recognition of the disease. Monitoring, through registries, of HIV-AIDS cases is vital to assess general health care needs and to support long-term health-policy control planning. Surveillance systems are therefore established in almost all developed countries. Typically, this is a complex system depending on several stakeholders, such as health care providers, the general population and laboratories, which challenges an efficient and effective reporting of diagnosed cases. One issue that often arises is the administrative delay in reports of diagnosed cases. This paper aims to identify the main factors influencing reporting delays of HIV-AIDS cases within the portuguese surveillance system. The used methodologies included multilayer artificial neural networks (MLP), naive bayesian classifiers (NB), support vector machines (SVM) and the k-nearest neighbor algorithm (KNN). The highest classification accuracy, precision and recall were obtained for MLP and the results suggested homogeneous administrative and clinical practices within the reporting process. Guidelines for reductions of the delays should therefore be developed nationwise and transversally to all stakeholders.- A. Rita Gaio was partially supported by CMUP (UID/MAT/00144/2013), which is funded by FCT (Portugal) with national (MEC) and European structural funds (FEDER), under the partnership agreement PT2020. Luis Paulo Reis was partially by the European Regional Development Fund through the programme COMPETE by FCT (Portugal) in the scope of the project PEst - UID/ CEC/00027/2015 Luis Paulo Reis and Brigida Monica Faria were partially funded by QVida+: Estimacao Continua de Qualidade de Vida para Auxilio Eficaz a Decisao Clinica, NORTE-01-0247-FEDER-003446, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement

Desenvolvimento de microestrutura ferrítica martensítica em aço baixo carbono durante laminação a quente em escala piloto

Foi estudado neste trabalho uma liga de aço de baixo carbono, contendo Mn, elaborado em escala industrial, a fim de se definir o procedimento de laminação a quente em escala piloto, relacionada com a temperatura de reaquecimento e a temperatura acabamento mínimo no campo da austenita, um tratamento térmico (imersão a temperatura de 1000 º C por 360s e aquecimento / taxa de resfriamento de 1 ºC / s) foi executado em um dilatômetro de têmpera (Adhamel, DT1000). Este aço foi laminado a quente em escala piloto no campo austenítico, com espessura de oito etapas de redução e resfriamento no ar até o campo inter-crítico (Ac3 e Ac1) com água de resfriamento subseqüente à temperatura ambiente, a fim de obter uma estrutura ferrítico-martensítico. A evolução microestrutural após o processamento foi avaliada por microscopia (óptica e eletrônica de varredura) e testes de dureza. As mudanças morfológicas e microestrutural nos grãos austeníticos após a etapa 8 da laminação a quente permitiram discutir possíveis fenômenos (recuperação e / ou recristalização dinâmica e estática, ou de não recristalização) associados com a composição química, durante o processamento termomecânico aplicado para o aço estudado. Com base na literatura, espera-se que Mn tenha desenvolvido um grão austeníticos deformados que afeta a nucleação de grãos ferríticos e martensíticos após a sua transformação no resfriamento controlado a nível de campo inter-crítico

Advance in the conceptual design of the European DEMO magnet system

The European DEMO, i.e. the demonstration fusion power plant designed in the framework of the Roadmap to Fusion Electricity by the EUROfusion Consortium, is approaching the end of the pre-conceptual design phase, to be accomplished with a Gate Review in 2020, in which all DEMO subsystems will be reviewed by panels of independent experts. The latest 2018 DEMO baseline has major and minor radius of 9.1 m and 2.9 m, plasma current 17.9 MA, toroidal field on the plasma axis 5.2 T, and the peak field in the toroidal-field (TF) conductor 12.0 T. The 900 ton heavy TF coil is prepared in four lowerature-superconductor (LTS) variants, some of them differing slightly, other significantly, from the ITER TF coil design. Two variants of the CS coils are investigated - a purely LTS one resembling the ITER CS, and a hybrid coil, in which the innermost layers made of HTS allow the designers either to increase the magnetic flux, and thus the duration of the fusion pulse, or to reduce the outer radius of the CS coil. An issue presently investigated by mechanical analyzes is the fatigue load. Two variants of the poloidal field coils are being investigated. The magnet and conductor design studies are accompanied by the experimental tests on both LTS and HTS prototype samples, covering a broad range of DC and AC tests. Testing of quench behavior of the 15 kA HTS cables, with size and layout relevant for the fusion magnets and cooled by forced flow helium, is in preparation.</p

A new method for measuring angle-resolved phases in photoemission

Quantum mechanically, photoionization can be fully described by the complex photoionization amplitudes that describe the transition between the ground state and the continuum state. Knowledge of the value of the phase of these amplitudes has been a central interest in photoionization studies and newly developing attosecond science, since the phase can reveal important information about phenomena such as electron correlation. We present a new attosecond-precision interferometric method of angle-resolved measurement for the phase of the photoionization amplitudes, using two phase-locked Extreme Ultraviolet pulses of frequency $\omega$ and $2\omega$, from a Free-Electron Laser. Phase differences $\Delta \tilde \eta$ between one- and two-photon ionization channels, averaged over multiple wave packets, are extracted for neon $2p$ electrons as a function of emission angle at photoelectron energies 7.9, 10.2, and 16.6 eV. $\Delta \tilde \eta$ is nearly constant for emission parallel to the electric vector but increases at 10.2 eV for emission perpendicular to the electric vector. We model our observations with both perturbation and \textit{ab initio} theory, and find excellent agreement. In the existing method for attosecond measurement, Reconstruction of Attosecond Beating By Interference of Two-photon Transitions (RABBITT), a phase difference between two-photon pathways involving absorption and emission of an infrared photon is extracted. Our method can be used for extraction of a phase difference between single-photon and two-photon pathways and provides a new tool for attosecond science, which is complementary to RABBITT