1,976 research outputs found
Cross-Presentation of a Spread-Defective MCMV Is Sufficient to Prime the Majority of Virus-Specific CD8+ T Cells
CD8+ T cells can be primed by peptides derived from endogenous proteins (direct presentation), or exogenously acquired protein (cross-presentation). However, the relative ability of these two pathways to prime CD8+ T cells during a viral infection remains controversial. Cytomegaloviruses (CMVs) can infect professional antigen presenting cells (APCs), including dendritic cells, thus providing peptides for direct presentation. However, the viral immune evasion genes profoundly impair recognition of infected cells by CD8+ T cells. Nevertheless, CMV infection elicits a very strong CD8+ T cell response, prompting its recent use as a vaccine vector. We have shown previously that deleting the immune evasion genes from murine cytomegalovirus (MCMV) that target class I MHC presentation, has no impact on the size or breadth of the CD8+ T cell response elicited by infection, suggesting that the majority of MCMV-specific CD8+ T cells in vivo are not directly primed by infected professional APCs. Here we use a novel spread-defective mutant of MCMV, lacking the essential glycoprotein gL, to show that cross-presentation alone can account for the majority of MCMV-specific CD8+ T cell responses to the virus. Our data support the conclusion that cross-presentation is the primary mode of antigen presentation by which CD8+ T cells are primed during MCMV infection
Variance fluctuations in nonstationary time series: a comparative study of music genres
An important problem in physics concerns the analysis of audio time series
generated by transduced acoustic phenomena. Here, we develop a new method to
quantify the scaling properties of the local variance of nonstationary time
series. We apply this technique to analyze audio signals obtained from selected
genres of music. We find quantitative differences in the correlation properties
of high art music, popular music, and dance music. We discuss the relevance of
these objective findings in relation to the subjective experience of music.Comment: 13 pages, 4 fig
End-User Development (EUD) : desenvolvimento pelo usuário final: conceitos, estratégias e casos de adoção : relatório de pesquisa
Pesquisa realizada com financiamento do Ministério da Ciência, Tecnologia, Inovações e Comunicações, Projeto de Cooperação “Aprimoramento do Framework de Soluções de Tecnologia da Informação”.Ministério da Ciência, Tecnologia, Inovações e Comunicaçõe
Desenvolvimento descentralizado por meio de End-User Development : avaliação tecnológica : relatório de pesquisa
Pesquisa realizada com financiamento do Ministério da Ciência, Tecnologia, Inovações e Comunicações, Projeto de Cooperação “Aprimoramento do Framework de Soluções de Tecnologia da Informação”. Ministério da Ciência, Tecnologia, Inovações e Comunicaçõe
Fuzzy Wavelet Neural Network Using a Correntropy Criterion for Nonlinear System Identification
Recent researches have demonstrated that the Fuzzy Wavelet Neural Networks (FWNNs) are an efficient tool to identify nonlinear systems. In these structures, features related to fuzzy logic, wavelet functions, and neural networks are combined in an architecture similar to the Adaptive Neurofuzzy Inference Systems (ANFIS). In practical applications, the experimental data set used in the identification task often contains unknown noise and outliers, which decrease the FWNN model reliability. In order to reduce the negative effects of these erroneous measurements, this work proposes the direct use of a similarity measure based on information theory in the FWNN learning procedure. The Mean Squared Error (MSE) cost function is replaced by the Maximum Correntropy Criterion (MCC) in the traditional error backpropagation (BP) algorithm. The input-output maps of a real nonlinear system studied in this work are identified from an experimental data set corrupted by different outliers rates and additive white Gaussian noise. The results demonstrate the advantages of the proposed cost function using the MCC as compared to the MSE. This work also investigates the influence of the kernel size on the performance of the MCC in the BP algorithm, since it is the only free parameter of correntropy
Doses cumulativas de iodo radioativo no tratamento do carcinoma diferenciado de tireoide: sabendo a hora de parar
OBJECTIVE: Evaluate the efficacy of cumulative doses (CDs) of 131I-iodide therapy (RIT) in differentiated thyroid cancer (DTC). SUBJECTS AND METHODS: The probability of progressive disease according to CDs was evaluated in patients < 45 years old and > 45 years old and correlated to tumor-node-metastasis (TNM), thyroglobulin values, histological types and variants, age, and zduration of the disease. RESULTS: At the end of a follow-up period of 69 ± 56 months, 85 out of 150 DTC patients submitted to fixed doses RIT had no evidence of disease, 47 had stable disease and 18 had progressive disease. Higher CDs were used in the more aggressive variants (p < 0.0001), higher TNM stages (p < 0.0001), and follicular carcinomas (p = 0.0034). Probability of disease progression was higher with CDs > 600 mCi in patients > 45 years old and with CDs > 800 mCi in patients < 45 years. CONCLUSION: Although some patients may still respond to high CDs, the impact of further RIT should be carefully evaluated and other treatment strategies may be warranted.OBJETIVO: Avaliar a eficácia de doses cumulativas (DCs) da terapia com iodeto-131I (RIT) no câncer diferenciado de tiroide (CDT). SUJEITOS E MÉTODOS: A probabilidade de doença em progressão conforme a DC foi calculada em pacientes com idade < 45 e > 45 anos e correlacionada com o TNM, valores de tiroglobulina sérica, tipos histológicos e variantes, idade e tempo de doença. RESULTADOS: Ao final de um seguimento de 69 ± 56 meses, 85 dos 150 pacientes CDT submetidos a doses fixas de RIT não tinham evidência de doença, 47 tinham doença estável e 18, doença progressiva. DCs mais elevadas foram usadas nas variantes agressivas (p < 0,0001), maior estágio TNM (p < 0,0001) e nos carcinomas foliculares (p = 0,0034). A probabilidade de doença em progressão foi maior com DCs > 600 mCi em pacientes > 45 anos e com DCs > 800 mCi em pacientes < 45 anos. CONCLUSÃO: Apesar de alguns pacientes ainda responderem a altas DCs, o impacto de RITs deve ser cuidadosamente avaliado e outras estratégias terapêuticas devem ser consideradas.80781
Cumulative Doses Of Radioiodine In The Treatment Of Differentiated Thyroid Carcinoma: Knowing When To Stop.
Evaluate the efficacy of cumulative doses (CDs) of 131I-iodide therapy (RIT) in differentiated thyroid cancer (DTC). The probability of progressive disease according to CDs was evaluated in patients 45 years old and correlated to tumor-node-metastasis (TNM), thyroglobulin values, histological types and variants, age, and zduration of the disease. At the end of a follow-up period of 69 ± 56 months, 85 out of 150 DTC patients submitted to fixed doses RIT had no evidence of disease, 47 had stable disease and 18 had progressive disease. Higher CDs were used in the more aggressive variants (p 600 mCi in patients > 45 years old and with CDs > 800 mCi in patients < 45 years. Although some patients may still respond to high CDs, the impact of further RIT should be carefully evaluated and other treatment strategies may be warranted.54807-1
<i>Gaia</i> Data Release 1. Summary of the astrometric, photometric, and survey properties
Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7.
Aims. A summary of Gaia DR1 is presented along with illustrations of the scientific quality of the data, followed by a discussion of the limitations due to the preliminary nature of this release.
Methods. The raw data collected by Gaia during the first 14 months of the mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC) and turned into an astrometric and photometric catalogue.
Results. Gaia DR1 consists of three components: a primary astrometric data set which contains the positions, parallaxes, and mean proper motions for about 2 million of the brightest stars in common with the HIPPARCOS and Tycho-2 catalogues – a realisation of the Tycho-Gaia Astrometric Solution (TGAS) – and a secondary astrometric data set containing the positions for an additional 1.1 billion sources. The second component is the photometric data set, consisting of mean G-band magnitudes for all sources. The G-band light curves and the characteristics of ∼3000 Cepheid and RR-Lyrae stars, observed at high cadence around the south ecliptic pole, form the third component. For the primary astrometric data set the typical uncertainty is about 0.3 mas for the positions and parallaxes, and about 1 mas yr−1 for the proper motions. A systematic component of ∼0.3 mas should be added to the parallax uncertainties. For the subset of ∼94 000 HIPPARCOS stars in the primary data set, the proper motions are much more precise at about 0.06 mas yr−1. For the secondary astrometric data set, the typical uncertainty of the positions is ∼10 mas. The median uncertainties on the mean G-band magnitudes range from the mmag level to ∼0.03 mag over the magnitude range 5 to 20.7.
Conclusions. Gaia DR1 is an important milestone ahead of the next Gaia data release, which will feature five-parameter astrometry for all sources. Extensive validation shows that Gaia DR1 represents a major advance in the mapping of the heavens and the availability of basic stellar data that underpin observational astrophysics. Nevertheless, the very preliminary nature of this first Gaia data release does lead to a number of important limitations to the data quality which should be carefully considered before drawing conclusions from the data
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