880 research outputs found
MUSE observations of a changing-look AGN I: The re-appearance of the broad emission lines
Optical changing-look Active Galactic Nuclei (AGN) are a class of sources
that change type within a short timescale of years or decades. This change is
characterised by the appearance or disappearance of broad emission lines, often
associated with dramatic AGN continuum flux changes that are orders of
magnitude larger than those expected from typical AGN variability. In this work
we study for the first time the host galaxy of a changing-look AGN, Mrk 590,
using high spatial resolution optical and near-infrared observations. We
discover that after ~ 10 yr absence, the optical broad emission lines of Mrk
590 have reappeared. The AGN optical continuum flux however, is still ~ 10
times lower than that observed during the most luminous state in the 1990s. The
host galaxy shows a 4.5 kpc radius star-forming ring with knots of ionised and
cold molecular gas emission. Extended ionised and warm molecular gas emission
are detected in the nucleus, indicating that there is a reservoir of gas as
close as 60 pc from the black hole. We observe a nuclear gas spiral between
radii r ~ 0.5 - 2 kpc, which has been suggested as a dynamical mechanism able
to drive the necessary gas to fuel AGN. We also discover blue-shifted and high
velocity dispersion [O III] emission out to a radius of 1 kpc, tracing a
nuclear gas outflow. The gas dynamics in Mrk 590 suggest a complex balance
between gas inflow and outflow in the nucleus of the galaxy.Comment: Accepted for publication in MNRA
MODELING the INTERACTION BETWEEN AIDS and TUBERCULOSIS
A deterministic model is proposed for the study of the dynamics of acquired immunodeficiency syndrome (AIDS) and tuberculosis (TB) co-infection. the model is comprised by a set of sixteen ordinary differential equations representing different states of both diseases, and it is intended to provide a theoretical framework for the study of the interaction between both infections. Numerical simulations of the model resulted in three striking outcomes: first, the pathogenicity of Human Immunodeficiency Virus (HIV) is enhanced by the presence of TB, and vice-versa; second, the prevalence of AIDS is higher in the presence of TB; and third, relative risk analysis demonstrated a much stronger influence of AIDS on TB than the other way around.ESCOLA PAULISTA MED,BR-04023 São Paulo,BRAZILUNIV São Paulo,INST PHYS,São Paulo,BRAZILHCFMUSP,BR-01246 São Paulo,BRAZILESCOLA PAULISTA MED,BR-04023 São Paulo,BRAZILWeb of Scienc
Variação sazonal e influência de fatores meteorológicos na incidência de descolamentos regmatógenos da retina na zona centro de Portugal e na Madeira
Objetivos: Analisar a variação sazonal e a influência de fatores meteorológicos na incidência
a 5 anos de descolamento regmatógeno da retina (DRR), na região centro do país e região autónoma
da Madeira (RAM).
Métodos: Série de casos consecutiva, retrospetiva e multicêntrica. Incluíram-se doentes submetidos
a cirurgia de DRR no Centro Hospitalar e Universitário de Coimbra e Hospital Doutor
Nélio Mendonça entre Janeiro’10 e Dezembro’14. A seleção de casos foi feita através codificação
ICD-9-CM e os critérios de inclusão foram: 1)idade ≥18 anos; 2)DRR de novo; 3)reparação
cirúrgica do DRR. Consideraram-se critérios de exclusão: 1)DR tracional, exsudativo ou misto;
2)DR antigo ou re-descolamento; 3)soluções de continuidade ou lesões regmatógenas tratadas
apenas com laser. Os dados meteorológicos diários das estações de Coimbra, Leiria, Aveiro,
Viseu, Guarda, Castelo Branco e Funchal, foram utilizados na análise estatística.
Resultados: Foram incluídos 1013 olhos (914 da região centro e 99 da RAM), com idade
média 61,84±14,00 anos. Através de um modelo cronológico de regressão linear constatou-se
a presença de sazonalidade com picos nos meses de Maio e Setembro. A temperatura média
apresentou uma associação marginalmente significativa com a incidência de DRR num modelo
biológico de regressão linear considerando os mais fortes preditores de DRR da amostra.
Conclusões: Os nossos resultados demonstram que a incidência de DRR se associa a um padrão
sazonal significativo que parece ser explicado pela temperatura. Este estudo alerta para a
necessidade de um eficaz planeamento em saúde que deverá passar por uma gestão harmoniosa
de recursos humanos em épocas de maior incidência
Radio propagation measurements and modeling for standardization of the site general path loss model in International Telecommunications Union recommendations for 5G wireless networks
The International Telecommunications Union Radiocommunication Sector (ITU‐R) Study Group 3 identified the need for a number of radio channel models in anticipation of the World Radiocommunications Conference in 2019 when the frequency allocation for 5G will be discussed. In response to the call for propagation path loss models, members of the study group carried out measurements in the frequency bands between 0.8 GHz up to 73 GHz in urban low rise and urban high rise as well as suburban environments. The data were subsequently merged to generate site general path loss models. The paper presents an overview of the radio channel measurements, the measured environments, the data analysis and the approach for the derivation of the path loss model adopted in Recommendation ITU‐R P.1411‐10
Frailty as the Future Core Business of Public Health: Report of the Activities of the A3 Action Group of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA)
Background: The prevalence of frailty at population-level is expected to increase in Europe, changing the focus of Public Health. Here, we report on the activities of the A3 Action Group, focusing on managing frailty and supporting healthy ageing at community level. Methods: A three-phased search strategy was used to select papers published between January 2016 and May 2018. In the third phase, the first manuscript draft was sent to all A3-Action Group members who were invited to suggest additional contributions to be included in the narrative review process. Results: A total of 56 papers were included in this report. The A3 Action Group developed three multidimensional tools predicting short–medium term adverse outcomes. Multiple factors were highlighted by the group as useful for healthcare planning: malnutrition, polypharmacy, impairment of physical function and social isolation were targeted to mitigate frailty and its consequences. Studies focused on the management of frailty highlighted that tailored interventions can improve physical performance and reduce adverse outcomes. Conclusions: This review shows the importance of taking a multifaceted approach when addressing frailty at community level. From a Public Health perspective, it is vital to identify factors that contribute to successful health and social care interventions and to the health systems sustainability
Electrochemical oxidation of mitoxantrone at a glassy carbon electrode
Mitoxantrone is an anthracycline used as an antitumour antibiotic for leukaemia and breast cancer treatment, due to its interaction with DNA. However, the molecular mechanism of the antitumour action is not completely understood. Using a glassy carbon electrode the electrochemical oxidation of mitoxantrone was shown to be a complex, pH-dependent, irreversible electrode process involving several metabolites. Comparison of the electrochemical oxidation behaviour of mitoxantrone, ametantrone and aminantrone enabled a deeper understanding of the mechanism and showed the relevance of electrochemical data for the understanding of the cytotoxicity of mitoxantrone. Since mitoxantrone and its oxidation products adsorb strongly on the electrode surface, causing severe problems of electrode fouling, reproducible electroanalytical determinations could only be done at very low concentrations and in an aqueous buffer supporting electrolyte containing 30% ethanol. The detection limit obtained was 10-7 M.http://www.sciencedirect.com/science/article/B6TF4-3W3N6Y2-1J/1/5ffa47da56de732d1903bdf9a6c163c
Topological Superconductor from the Quantum Hall Phase: Effective Field Theory Description
We derive low-energy effective field theories for the quantum anomalous Hall
and topological superconducting phases. The quantum Hall phase is realized in
terms of free fermions with nonrelativistic dispersion relation, possessing a
global symmetry. We couple this symmetry with a background gauge field
and compute the effective action by integrating out the gapped fermions. In
spite of the fact that the corresponding Dirac operator governing the dynamics
of the original fermions is nonrelativistic, the leading contribution in the
effective action is a usual Abelian Chern-Simons term. The proximity to
a conventional superconductor induces a pairing potential in the quantum Hall
state, favoring the formation of Cooper pairs. When the pairing is strong
enough, it drives the system to a topological superconducting phase, hosting
Majorana fermions. Even though the continuum symmetry is broken down to
a one, we can forge fictitious symmetries that enable us
to derive the effective action for the topological superconducting phase, also
given by a Chern-Simons theory. To eliminate spurious states coming from the
artificial symmetry enlargement, we demand that the fields in the effective
action are instead of gauge fields. In the case we have to
sum over the bundles in the partition function, which projects
out the states that are not invariants. The corresponding edge
theory is the orbifold, which contains Majorana fermions in
its operator content.Comment: 40 pages, 5 figures, journal versio
Gran method for end point anticipation in monosegmented flow titration
An automatic potentiometric monosegmented flow titration procedure based on Gran linearisation approach has been developed. The controlling program can estimate the end point of the titration after the addition of three or four aliquots of titrant. Alternatively, the end point can be determined by the second derivative procedure. In this case, additional volumes of titrant are added until the vicinity of the end point and three points before and after the stoichiometric point are used for end point calculation. The performance of the system was assessed by the determination of chloride in isotonic beverages and parenteral solutions. The system employs a tubular Ag2S/AgCl indicator electrode. A typical titration, performed according to the IUPAC definition, requires only 60 mL of sample and about the same volume of titrant (AgNO3) solution. A complete titration can be carried out in 1 - 5 min. The accuracy and precision (relative standard deviation of ten replicates) are 2% and 1% for the Gran and 1% and 0.5% for the Gran/derivative end point determination procedures, respectively. The proposed system reduces the time to perform a titration, ensuring low sample and reagent consumption, and full automatic sampling and titrant addition in a calibration-free titration protocol.Este trabalho descreve o uso do método de linearização de Gran em titulações em fluxo monossegmentado com detecção potenciométrica. O programa de controle pode estimar o ponto final após a adição de três ou quatro alíquotas de titulante. Alternativamente, o ponto final da titulação pode ser determinado pelo método da segunda derivada. Neste caso, alíquotas adicionais de titulante são adicionadas até a proximidade do ponto final e três pontos antes e após o ponto estequiométrico são usados para o cálculo de ponto final. O desempenho do sistema foi avaliado pela determinação de cloreto em soluções isotônicas e parenterais. O sistema emprega um eletrodo indicador tubular de Ag2S/AgCl. Uma titulação típica, realizada de acordo com a definição IUPAC, requer apenas 60 mL de amostra e aproximadamente o mesmo volume de titulante (AgNO3). Uma titulação completa pode ser realizada entre 1 e 5 min. Foram obtidas exatidão e precisão (desvio padrão relativo de 10 replicatas) de 2% e 1% para o método de Gran e 1% e 0,5% para o método de Gran associado ao método da segunda derivada, respectivamente. O sistema proposto reduz o tempo para realizar uma titulação, com baixo consumo de amostra e reagente, além de possibilitar uma amostragem automática completa e adição de titulante sem a necessidade de uma etapa de calibração.111115Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES
Design and development of a multichannel potentiometer for monitoring an electrode array and its application in flow analysis
A versatile potentiometer that works with electrode arrays in flow injection and/or monosegmented flow systems is described. The potentiometer is controlled by a microcomputer that allows individual, sequential multiplexed or random accesses to eight electrodes while employing only one reference electrode. The instrument was demonstrated by monitoring an array of seven flow-through ion-selective electrodes for Ag+ and for three electrodes for Cl-, Ca2+ and K+. The figures of merit of the individual and multiplexed (summed) readings of the electrode array were compared. The absolute standard deviation of the measurements made by summing the potential of two or more electrodes was maintained constant, thus improving the precision of the measurements. This result shows that an attempt to combine the signals of the electrodes to produce a more intense signal in the Hadamard strategy is feasible and accompanied by a proportional improvement in the precision of individual measurements. The preliminary tests suggest that the system can allow for 270 determinations per hour, with a linear range from 1.0 × 10-2 to 1.0 × 10-4 mol l-1 for the three di¡erent analytes. Detection limits were estimated as 3.1 × 10-5, 3.0 × 10-6 and 1.0 × 10-5 mol l-1 for Cl-, Ca2+ and K+, respectively
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