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How black holes accrete surrounding matter is a fundamental yet unsolved question in astrophysics. It is generally believed that matter is absorbed into black holes via accretion disks, the state of which depends primarily on the mass-accretion rate. When this rate approaches the critical rate (the Eddington limit), thermal instability is supposed to occur in the inner disk, causing repetitive patterns of large-amplitude X-ray variability (oscillations) on timescales of minutes to hours. In fact, such oscillations have been observed only in sources with a high mass-accretion rate, such as GRS 1915+105 (refs 2, 3). These large-amplitude, relatively slow timescale, phenomena are thought to have physical origins distinct from those of X-ray or optical variations with small amplitudes and fast timescales (less than about 10 seconds) often observed in other black-hole binaries-for example, XTE J1118+480 (ref. 4) and GX 339-4 (ref. 5). Here we report an extensive multi-colour optical photometric data set of V404 Cygni, an X-ray transient source containing a black hole of nine solar masses (and a companion star) at a distance of 2.4 kiloparsecs (ref. 8). Our data show that optical oscillations on timescales of 100 seconds to 2.5 hours can occur at mass-accretion rates more than ten times lower than previously thought. This suggests that the accretion rate is not the critical parameter for inducing inner-disk instabilities. Instead, we propose that a long orbital period is a key condition for these large-amplitude oscillations, because the outer part of the large disk in binaries with long orbital periods will have surface densities too low to maintain sustained mass accretion to the inner part of the disk. The lack of sustained accretion--not the actual rate--would then be the critical factor causing large-amplitude oscillations in long-period systems.
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A recent approach to explaining the domain-general cognitive outcomes of bilingualism is to consider the role of disengagement of attention, rather than the engagement of focused attention or inhibition as typical in most accounts. The present study pursues this approach by examining the neurophysiological changes associated with disengagement of attention in young adults performing an inhibition of return (IOR) paradigm while EEG was recorded. Participants were drawn from a diverse community and varied widely in their bilingual experience. There were three main findings. First, dividing the sample into dichotomous groups based on language proficiency did not lead to reliable group differences on the task. Second, using instead continuous measures of bilingualism across the sample indicated that greater bilingual experience and proficiency were associated with the magnitude of the IOR effect, with more bilingual individuals showing larger and earlier IOR effects. Finally, a network of processes that are temporally and spatially distinct were found to work together to produce facilitation, disengagement of attention, and inhibition of return. These findings contribute to debates regarding the electrophysiological correlates of the IOR effect and provide additional evidence for how bilingualism affects domain-general cognition.
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BACKGROUND: The promises of improved health care and health research through data-intensive applications rely on a growing amount of health data. At the core of large-scale data integration efforts, clinical data warehouses (CDW) are also responsible for data governance, managing data access and (re)use. As the complexity of the data flow increases, greater transparency and standardization of criteria and procedures are required in order to maintain objective oversight and control. Therefore, the development of practice oriented and evidence-based policies is crucial. This study assessed the spectrum of data access and use criteria and procedures in clinical data warehouses governance internationally. METHODS: We performed a systematic review of (a) the published scientific literature on CDW and (b) publicly available information on CDW data access, e.g., data access policies. A qualitative thematic analysis was applied to all included literature and policies. RESULTS: Twenty-three scientific publications and one policy document were included in the final analysis. The qualitative analysis led to a final set of three main thematic categories: (1) requirements, including recipient requirements, reuse requirements, and formal requirements; (2) structures and processes, including review bodies and review values; and (3) access, including access limitations. CONCLUSIONS: The description of data access and use governance in the scientific literature is characterized by a high level of heterogeneity and ambiguity. In practice, this might limit the effective data sharing needed to fulfil the high expectations of data-intensive approaches in medical research and health care. The lack of publicly available information on access policies conflicts with ethical requirements linked to principles of transparency and accountability. CDW should publicly disclose by whom and under which conditions data can be accessed, and provide designated governance structures and policies to increase transparency on data access. The results of this review may contribute to the development of practice-oriented minimal standards for the governance of data access, which could also result in a stronger harmonization, efficiency, and effectiveness of CDW.
Assuntos
Pesquisa Biomédica , Data Warehousing , Confidencialidade , Atenção à Saúde , Humanos , PolíticasRESUMO
Molecular vibrations couple to visible light only weakly, have small mutual interactions, and hence are often ignored for non-linear optics. Here we show the extreme confinement provided by plasmonic nano- and pico-cavities can sufficiently enhance optomechanical coupling so that intense laser illumination drastically softens the molecular bonds. This optomechanical pumping regime produces strong distortions of the Raman vibrational spectrum related to giant vibrational frequency shifts from an optical spring effect which is hundred-fold larger than in traditional cavities. The theoretical simulations accounting for the multimodal nanocavity response and near-field-induced collective phonon interactions are consistent with the experimentally-observed non-linear behavior exhibited in the Raman spectra of nanoparticle-on-mirror constructs illuminated by ultrafast laser pulses. Further, we show indications that plasmonic picocavities allow us to access the optical spring effect in single molecules with continuous illumination. Driving the collective phonon in the nanocavity paves the way to control reversible bond softening, as well as irreversible chemistry.
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We report the isolation and detailed characterization of the novel strain, Partizansk/2006, of Powassan virus (POWV) from a human case of infection, which occurred in Primorsky krai, Russia, in 2006. Comparative complete genome sequence analysis of the Far Eastern strains Spassk-9 (1975), Nadezdinsk-1991 and Partizansk/2006 of POWV revealed that these strains are 99.8% similar to the LB strain, which was isolated in Canada in 1958. Phylogenetic analysis of 5' UTR sequences of five other strains of POWV isolated from 1972 to 1986 in Primorsky krai produced similar results. Presumably, Far Eastern POWV has common putative ancestor with LB strain POWV from North America, and the time of divergence of these POWVs is relatively short. We conclude that POWV has become endemic in Far Eastern Russia.
Assuntos
Vírus da Encefalite Transmitidos por Carrapatos/genética , Vírus da Encefalite Transmitidos por Carrapatos/isolamento & purificação , Genoma Viral , Filogenia , Animais , Sequência de Bases , Células Cultivadas , Hibridização Genômica Comparativa , Vírus da Encefalite Transmitidos por Carrapatos/classificação , Encefalite Transmitida por Carrapatos/virologia , Evolução Molecular , Humanos , Microscopia Eletrônica de Transmissão , Dados de Sequência Molecular , Testes de Neutralização , Conformação de Ácido Nucleico , RNA Viral/genética , Federação Russa , Análise de Sequência de RNA , SuínosRESUMO
We assessed the humoral immunity of 290 vaccinated persons against tick-borne encephalitis (TBE). During the first year and 2 years after the primary three vaccinations the antibodies to the Far Eastern subtype tick-borne encephalitis virus strain P-73 were detected by neutralization test after immunization with FSME-Immune Inject vaccine (Baxter Vaccine AG, Austria) in 88.2% and 78.1% vaccinated persons, respectively; with Encepur((R)) Adult vaccine (Novartis Vaccines, Germany), in 100% and 100%; with the vaccine of the Chumakov Institute of Poliomyelitis and Viral Encephalitides RAMSci (Russia), in 100% and 94.1%; with EnceVir vaccine (Russia), in 88.2% and 83.9%; and after combined vaccination, in 100% and 92.7%. The dynamics of the decrease in IgG avidity index correlated with the changes of antibody titers determined by neutralization test. After the primary vaccination course, the titers of virus-neutralizing antibodies were high (6.3-7.4 log(2)) when the avidity index of IgG antibodies were 31% and more; thus, this level can be considered immunologically significant. Two years after the primary vaccination course, the IgG avidity indexes of 60% and more can be regarded as significant on the background of the GMT decrease of virus-neutralizing antibodies. These results allow us to recommend all four vaccines for mass vaccination and an assay of IgG avidity, along with neutralization test, for a more adequate assessment of the level of postvaccination immune response.
Assuntos
Anticorpos Antivirais/imunologia , Afinidade de Anticorpos/imunologia , Vírus da Encefalite Transmitidos por Carrapatos/imunologia , Encefalite Transmitida por Carrapatos/imunologia , Vacinas Virais/imunologia , Anticorpos Antivirais/sangue , Ásia Oriental , Humanos , Imunoensaio , Testes de Neutralização , TitulometriaRESUMO
We studied humoral immune response of 44 volunteers from Primorsky krai (Russia) immunized with the vaccine Encepur Adult. Induction of the humoral response towards the recently isolated tick-borne encephalitis virus (TBEV) strains P-69, P-202, and P-73 was evaluated by neutralization test and enzyme immunoassay. These strains belong to Far Eastern TBEV subtype based on their genotype and antigenic structure but maintain significant genetic and antigenic variability. The average geometric titers of neutralizing antibodies to P-69, P-202, and P-73 strains were 1:28, 1:34, and 1:128, respectively. The percentage of volunteers with neutralizing antibodies to these strains after complete course immunization was 63.9, 97.6, and 95.5%, respectively. We concluded that Encepur Adult vaccine induced pronounced humoral immune response towards genetically and antigenically heterogeneous strains of the Far Eastern TBEV subtype.