119 research outputs found

    Multi-messenger observations of a binary neutron star merger

    Get PDF
    On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

    Genetic Diversity in the SIR Model of Pathogen Evolution

    Get PDF
    We introduce a model for assessing the levels and patterns of genetic diversity in pathogen populations, whose epidemiology follows a susceptible-infected-recovered model (SIR). We model the population of pathogens as a metapopulation composed of subpopulations (infected hosts), where pathogens replicate and mutate. Hosts transmit pathogens to uninfected hosts. We show that the level of pathogen variation is well predicted by analytical expressions, such that pathogen neutral molecular variation is bounded by the level of infection and increases with the duration of infection. We then introduce selection in the model and study the invasion probability of a new pathogenic strain whose fitness (R0(1+s)) is higher than the fitness of the resident strain (R0). We show that this invasion probability is given by the relative increment in R0 of the new pathogen (s). By analyzing the patterns of genetic diversity in this framework, we identify the molecular signatures during the replacement and compare these with those observed in sequences of influenza A

    Influenza A Gradual and Epochal Evolution: Insights from Simple Models

    Get PDF
    The recurrence of influenza A epidemics has originally been explained by a “continuous antigenic drift” scenario. Recently, it has been shown that if genetic drift is gradual, the evolution of influenza A main antigen, the haemagglutinin, is punctuated. As a consequence, it has been suggested that influenza A dynamics at the population level should be approximated by a serial model. Here, simple models are used to test whether a serial model requires gradual antigenic drift within groups of strains with the same antigenic properties (antigenic clusters). We compare the effect of status based and history based frameworks and the influence of reduced susceptibility and infectivity assumptions on the transient dynamics of antigenic clusters. Our results reveal that the replacement of a resident antigenic cluster by a mutant cluster, as observed in data, is reproduced only by the status based model integrating the reduced infectivity assumption. This combination of assumptions is useful to overcome the otherwise extremely high model dimensionality of models incorporating many strains, but relies on a biological hypothesis not obviously satisfied. Our findings finally suggest the dynamical importance of gradual antigenic drift even in the presence of punctuated immune escape. A more regular renewal of susceptible pool than the one implemented in a serial model should be part of a minimal theory for influenza at the population level

    Relação entre autoavaliação vocal e dados da avaliação clínica em indivíduos disfônicos

    Full text link
    OBJETIVO: associar os índices de autoavaliação vocal aos dados da avaliação clínica de indivíduos disfônicos. MÉTODOS: estudo observacional, analítico, retrospectivo. Foram analisados os prontuários de pacientes disfônicos atendidos em uma Clínica-Escola de Fonoaudiologia no período de 2007 a 2011. Foram levantados os dados referentes à autoavaliação vocal (índices de qualidade de vida em voz, desvantagem vocal e atribuição de nota referente ao impacto vocal), à anamnese (sexo, idade, profissão, tipo de queixa, tempo de queixa, tratamentos anteriores para a disfonia), à avaliação perceptivo-auditiva (qualidade vocal, grau de alteração, pitch, loudness, ressonância, articulação e coordenação pneumofonoarticulatória) e aos dados objetivos (tempos máximos fonatórios e relação s/z). Os dados foram tabulados e analisados estatisticamente. RESULTADOS: não houve diferença na comparação dos escores do protocolo de qualidade de vida em voz e índice de desvantagem vocal com as variáveis referentes a sexo, qualidade vocal, grau de alteração, pitch, ressonância, articulação, velocidade de fala e tipo de disfonia. Indivíduos que utilizam a voz profissionalmente e que já fizeram tratamentos anteriores para a disfonia apresentaram piores índices na autoavaliação vocal. Quanto à avaliação clínica, a incoordenação penumofonoarticulatória foi o único parâmetro que interferiu negativamente na autoavaliação. Não houve correlações entre os índices de autoavaliação vocal e as demais variáveis contínuas (idade, tempo de queixa, tempos máximos fonatórios e relação s/z). CONCLUSÃO: a autoavaliação vocal é uma impressão bastante subjetiva, e independe da maior parte dos dados coletados na avaliação clínica. Ser profissional da voz, já ter buscado outros tratamentos para a disfonia e apresentar incoordenação penumofonoarticulatória parece influenciar negativamente na autoavaliação do indivíduo acerca do impacto do distúrbio vocal em sua vida diária

    Evaluation of digital educational studenttechnology interaction in neonatal nursing

    Get PDF
    OBJECTIVE To assess the digital educational technology interface Caring for the sensory environment in the neonatal unit: noise, lighting and handling based on ergonomic criteria. METHODS Descriptive study, in which we used the guidelines and ergonomic criteria established by ISO 9241-11 and an online Likert scale instrument to identify problems and interface qualities. The instrument was built based on Ergolist, which follows the criteria of ISO 9141-11. There were 58 undergraduate study participants from the School of Nursing of Ribeirao Preto, University of Sao Paulo, who attended the classes about neonatal nursing content. RESULTS All items were positively evaluated by more than 70% of the sample. CONCLUSION Educational technology is appropriate according to the ergonomic criteria and can be made available for teaching nursing students

    Guidance to 2018 good practice : ARIA digitally-enabled, integrated, person-centred care for rhinitis and asthma

    Get PDF
    AimsMobile Airways Sentinel NetworK (MASK) belongs to the Fondation Partenariale MACVIA-LR of Montpellier, France and aims to provide an active and healthy life to rhinitis sufferers and to those with asthma multimorbidity across the life cycle, whatever their gender or socio-economic status, in order to reduce health and social inequities incurred by the disease and to improve the digital transformation of health and care. The ultimate goal is to change the management strategy in chronic diseases.MethodsMASK implements ICT technologies for individualized and predictive medicine to develop novel care pathways by a multi-disciplinary group centred around the patients.StakeholdersInclude patients, health care professionals (pharmacists and physicians), authorities, patient's associations, private and public sectors.ResultsMASK is deployed in 23 countries and 17 languages. 26,000 users have registered.EU grants (2018)MASK is participating in EU projects (POLLAR: impact of air POLLution in Asthma and Rhinitis, EIT Health, DigitalHealthEurope, Euriphi and Vigour).Lessons learnt(i) Adherence to treatment is the major problem of allergic disease, (ii) Self-management strategies should be considerably expanded (behavioural), (iii) Change management is essential in allergic diseases, (iv) Education strategies should be reconsidered using a patient-centred approach and (v) Lessons learnt for allergic diseases can be expanded to chronic diseases.Peer reviewe
    corecore