1,438 research outputs found
Envelope-receptor interactions in Nipah virus pathobiology.
Nipah (NiV) and Hendra (HeV) viruses are members of the newly defined Henipavirus genus of the Paramyxoviridae. Nipah virus (NiV) is an emergent paramyxovirus that causes fatal encephalitis in up to 70% of infected patients, and there is increasing evidence of human-to-human transmission. NiV is designated a priority pathogen in the NIAID Biodefense Research Agenda, and could be a devastating agent of agrobioterrorism if used against the pig farming industry. Endothelial syncytium is a pathognomonic feature of NiV infections, and is mediated by the fusion (F) and attachment (G) envelope glycoproteins. This review summarizes what is known about the pathophysiology of NiV infections, and documents the identification of the NiV receptor. EphrinB2, the NiV and HeV receptor, is expressed on endothelial cells and neurons, consistent with the known cellular tropism for NiV. We discuss how the identification of the henipahvirus receptor sheds light on the pathobiology of NiV infection, and how it will spur the rational development of effective therapeutics. In addition, ephrinB3, a related protein, can serve as an alternative receptor, and we suggest that differential usage of ephrinB2 versus B3 may explain the variant pathogenic profiles observed between NiV and HeV. Thus, identifying the NiV receptors opens the door for a more comprehensive analysis of the envelope-receptor interactions in NiV pathobiology. Finally, we also describe how galectin-1 (an innate immune defense lectin) can interact with specific N-glycans on the Nipah envelope fusion protein, underscoring the potential role that innate immune defense mechanisms may play against emerging pathogens
INDIAN STATE-LEVEL RICE PRODUCTIVITY AND ITS IMPACT ON POVERTY ALLEVIATION
This paper has a three fold contribution to the existing literature - 1) Indian state level sorghum input and output data for the period 1970-71 to 2000-01 is collected, 2) non-parametric and parametric productivity measures are estimated, and 3) examine the impact of percent acreage under high yielding varieties and irrigation, state domestic product, productivity and five year plans on poverty alleviation using error component and SUR models.Research Methods/ Statistical Methods,
Optimizing feature extraction in image analysis using experimented designs, a case study evaluating texture algorithms for describing appearance retention in carpets
When performing image analysis, one of the most critical steps is the selection of appropriate techniques. A huge amount of features can be extracted from several techniques and the selection is commonly performed based on expert knowledge. In this paper we present the theory of experimental designs as a tool for an objective selection of techniques in image analysis domain. We present a study case for evaluating appearance retention in textile floor coverings using texture features. The use of experimental design theory permitted to select an optimal set of techniques for describing the texture changes due to degradation
Quantifying image distortion based on Gabor filter bank and multiple regression analysis
Image quality assessment is indispensable for image-based applications. The approaches towards image quality assessment fall into two main categories: subjective and objective methods. Subjective assessment has been widely used. However, careful subjective assessments are experimentally difficult and lengthy, and the results obtained may vary depending on the test conditions. On the other hand, objective image quality assessment would not only alleviate the difficulties described above but would also help to expand the application field. Therefore, several works have been developed for quantifying the distortion presented on a image achieving goodness of fit between subjective and objective scores up to 92%. Nevertheless, current methodologies are designed assuming that the nature of the distortion is known. Generally, this is a limiting assumption for practical applications, since in a majority of cases the distortions in the image are unknown. Therefore, we believe that the current methods of image quality assessment should be adapted in order to identify and quantify the distortion of images at the same time. That combination can improve processes such as enhancement, restoration, compression, transmission, among others. We present an approach based on the power of the experimental design and the joint localization of the Gabor filters for studying the influence of the spatial/frequencies on image quality assessment. Therefore, we achieve a correct identification and quantification of the distortion affecting images. This method provides accurate scores and differentiability between distortions
Real-time portable system for fabric defect detection using an ARM processor
Modern textile industry seeks to produce textiles as little defective as possible since the presence of defects can decrease the final price of products from 45% to 65%. Automated visual inspection (AVI) systems, based on image analysis, have become an important alternative for replacing traditional inspections methods that involve human tasks. An AVI system gives the advantage of repeatability when implemented within defined constrains, offering more objective and reliable results for particular tasks than human inspection. Costs of automated inspection systems development can be reduced using modular solutions with embedded systems, in which an important advantage is the low energy consumption. Among the possibilities for developing embedded systems, the ARM processor has been explored for acquisition, monitoring and simple signal processing tasks. In a recent approach we have explored the use of the ARM processor for defects detection by implementing the wavelet transform. However, the computation speed of the preprocessing was not yet sufficient for real time applications. In this approach we significantly improve the preprocessing speed of the algorithm, by optimizing matrix operations, such that it is adequate for a real time application. The system was tested for defect detection using different defect types. The paper is focused in giving a detailed description of the basis of the algorithm implementation, such that other algorithms may use of the ARM operations for fast implementations
Evaluation of color differences in natural scene color images
Since there is a wide range of applications requiring image color difference (CD) assessment (e.g. color quantization, color mapping), a number of CD measures for images have been proposed. However, the performance evaluation of such measures often suffers from the following major flaws: (1) test images contain primarily spatial- (e.g. blur) rather than color-specific distortions (e.g. quantization noise), (2) there are too few test images (lack of variability in color content), and (3) test images are not publicly available (difficult to reproduce and compare). Accordingly, the performance of CD measures reported in the state-of-the-art is ambiguous and therefore inconclusive to be used for any specific color-related application.
In this work, we review a total of twenty four state-of-the-art CD measures. Then, based on the findings of our review, we propose a novel method to compute CDs in natural scene color images. We have tested our measure as well as the state-of-the-art measures on three color related distortions from a publicly available database (mean shift, change in color saturation and quantization noise). Our experimental results show that the correlation between the subjective scores and the proposed measure exceeds 85% which is better than the other twenty four CD measures tested in this work (for illustration the best performing state-of-the-art CD measures achieve correlations with humans lower than 80%)
PARCERIA INTERINSTITUCIONAL COM O LABORATÓRIO DE GESTÃO
As tecnologias modernas propiciam recursos eletrônicos cada vez mais sofisticados para os cursos semipresenciais de Administração. Entretanto, as IES não exploram todo esse potencial quando os entregam a professores que replicam os modelos de ensino expositivo presencial. Revisitaram-se na literatura aspectos das estratégias de ensino-aprendizagem, da formação de novos docentes (educadores-aprendizes) e da dinâmica do Laboratório de Gestão SIMULAB, uma moderna metodologia brasileira de educação gerencial e pesquisa aplicada, apoiada por jogos de empresas, adotada em uma parceria internacional Brasil – Espanha. Foram conduzidas 2 oficinas para treinamento de educadores no Brasil e depois 3 oficinas para formação de estudantes na Espanha. A metodologia presencial conduzida em Português foi operada em formato semipresencial, em Espanhol, com bom aproveitamento. Foi possível em 12 meses sensibilizar, aculturar e treinar os educadores envolvidos para replicarem o Laboratório de Gestão - SIMULAB junto aos estudantes espanhóis. Dirigentes e coordenadores de IES têm diante de si a oportunidade e a responsabilidade de preparar educadores para lidarem com os novos desafios acadêmicos, dos programas e das disciplinas, capacitando os Administradores das novas gerações
Measuring hairiness in carpets by using surface metrology
Recently, an automatic system for grading appearance retention in carpets using our own scanner and image
analysis techniques was proposed. A system for carpets with low pile construction and without color patterns has been developed. Appearance changes in carpets with high pile construction were still not well detected. We present an approach based on surface metrology that extract information given by the hairs on the carpet surface. These features are complementary to the texture features previously explored. By combining both features, we expand the use of the automatic grading system including some carpets types with high pile construction
- …
