66 research outputs found

    Neural Networks for Hyperspectral Imaging of Historical Paintings: A Practical Review

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    Hyperspectral imaging (HSI) has become widely used in cultural heritage (CH). This very efficient method for artwork analysis is connected with the generation of large amounts of spectral data. The effective processing of such heavy spectral datasets remains an active research area. Along with the firmly established statistical and multivariate analysis methods, neural networks (NNs) represent a promising alternative in the field of CH. Over the last five years, the application of NNs for pigment identification and classification based on HSI datasets has drastically expanded due to the flexibility of the types of data they can process, and their superior ability to extract structures contained in the raw spectral data. This review provides an exhaustive analysis of the literature related to NNs applied for HSI data in the CH field. We outline the existing data processing workflows and propose a comprehensive comparison of the applications and limitations of the various input dataset preparation methods and NN architectures. By leveraging NN strategies in CH, the paper contributes to a wider and more systematic application of this novel data analysis method

    A bovine lymphosarcoma cell line infected with theileria annulata exhibits an irreversible reconfiguration of host cell gene expression

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    Theileria annulata, an intracellular parasite of bovine lymphoid cells, induces substantial phenotypic alterations to its host cell including continuous proliferation, cytoskeletal changes and resistance to apoptosis. While parasite induced modulation of host cell signal transduction pathways and NFÎșB activation are established, there remains considerable speculation on the complexities of the parasite directed control mechanisms that govern these radical changes to the host cell. Our objectives in this study were to provide a comprehensive analysis of the global changes to host cell gene expression with emphasis on those that result from direct intervention by the parasite. By using comparative microarray analysis of an uninfected bovine cell line and its Theileria infected counterpart, in conjunction with use of the specific parasitacidal agent, buparvaquone, we have identified a large number of host cell gene expression changes that result from parasite infection. Our results indicate that the viable parasite can irreversibly modify the transformed phenotype of a bovine cell line. Fifty percent of genes with altered expression failed to show a reversible response to parasite death, a possible contributing factor to initiation of host cell apoptosis. The genes that did show an early predicted response to loss of parasite viability highlighted a sub-group of genes that are likely to be under direct control by parasite infection. Network and pathway analysis demonstrated that this sub-group is significantly enriched for genes involved in regulation of chromatin modification and gene expression. The results provide evidence that the Theileria parasite has the regulatory capacity to generate widespread change to host cell gene expression in a complex and largely irreversible manner

    Bio++: Efficient Extensible Libraries and Tools for Computational Molecular Evolution

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    Efficient algorithms and programs for the analysis of the ever-growing amount of biological sequence data are strongly needed in the genomics era. The pace at which new data and methodologies are generated calls for the use of pre-existing, optimized—yet extensible—code, typically distributed as libraries or packages. This motivated the Bio++ project, aiming at developing a set of C++ libraries for sequence analysis, phylogenetics, population genetics, and molecular evolution. The main attractiveness of Bio++ is the extensibility and reusability of its components through its object-oriented design, without compromising the computer-efficiency of the underlying methods. We present here the second major release of the libraries, which provides an extended set of classes and methods. These extensions notably provide built-in access to sequence databases and new data structures for handling and manipulating sequences from the omics era, such as multiple genome alignments and sequencing reads libraries. More complex models of sequence evolution, such as mixture models and generic n-tuples alphabets, are also included

    Vanin-1 Pantetheinase Drives Smooth Muscle Cell Activation in Post-Arterial Injury Neointimal Hyperplasia

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    The pantetheinase vanin-1 generates cysteamine, which inhibits reduced glutathione (GSH) synthesis. Vanin-1 promotes inflammation and tissue injury partly by inducing oxidative stress, and partly by peroxisome proliferator-activated receptor gamma (PPARγ) expression. Vascular smooth muscle cells (SMCs) contribute to neointimal hyperplasia in response to injury, by multiple mechanisms including modulation of oxidative stress and PPARγ. Therefore, we tested the hypothesis that vanin-1 drives SMC activation and neointimal hyperplasia. We studied reactive oxygen species (ROS) generation and functional responses to platelet-derived growth factor (PDGF) and the pro-oxidant diamide in cultured mouse aortic SMCs, and also assessed neointima formation after carotid artery ligation in vanin-1 deficiency. Vnn1−/− SMCs demonstrated decreased oxidative stress, proliferation, migration, and matrix metalloproteinase 9 (MMP-9) activity in response to PDGF and/or diamide, with the effects on proliferation linked, in these studies, to both increased GSH levels and PPARγ expression. Vnn1−/− mice displayed markedly decreased neointima formation in response to carotid artery ligation, including decreased intima:media ratio and cross-sectional area of the neointima. We conclude that vanin-1, via dual modulation of GSH and PPARγ, critically regulates the activation of cultured SMCs and development of neointimal hyperplasia in response to carotid artery ligation. Vanin-1 is a novel potential therapeutic target for neointimal hyperplasia following revascularization

    Effect of hot calendering on physical properties and water vapor transfer resistance of bacterial cellulose films

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    This work investigates the effect of hot calendering on bacterial cellulose (BC) films properties, aiming the achievement of good transparency and barrier property. A comparison was made using vegetal cellulose (VC) films on a similar basis weight of around 40 g.m-2. The optical-structural, mechanical and barrier property of BC films were studied and compared with those of highly beaten VC films. The Youngs moduli and tensile index of the BC films are much higher than those obtained for VC (14.5 16.2 GPa vs 10.8 8.7 GPa and 146.7 64.8 N.m.g-1 vs 82.8 40.5 N.m.g-1), respectively. Calendering increased significantly the transparency of BC films from 53.0 % to 73.0 %. The effect of BC ozonation was also studied. Oxidation with ozone somewhat enhanced the brightness and transparency of the BC films, but at the expenses of slightly lower mechanical properties. BC films exhibited a low water vapor transfer rate, when compared to VC films and this property decreased by around 70 % following calendering, for all films tested. These results show that calendering could be used as a process to obtain films suitable for food packaging applications, where transparency, good mechanical performance and barrier properties are important. The BC films obtained herein are valuable products that could be a good alternative to the highly used plastics in this industry.The authors thank FCT (Fundação para a CiĂȘncia e Tecnologia) and FEDER (Fundo Europeu de Desenvolvimento Regional) for the ïŹnancial support of the project FCT PTDC/AGR-FOR/3090/2012— FCOMP-01-0124-FEDER-027948 and the awarding of a research grant for Vera Costa

    MULTIPLE 3D APPROACHES FOR THE ARCHITECTURAL STUDY OF THE MEDIEVAL ABBEY OF CORMERY IN THE LOIRE VALLEY

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    This paper will focus on the technical approaches used for a PhD thesis regarding architecture and spatial organization of benedict abbeys in Touraine in the Middle Ages, in particular the abbey of Cormery in the heart of the Loire Valley. Monastic space is approached in a diachronic way, from the early Middle Ages to the modern times using multi-sources data: architectural study, written sources, ancient maps, various iconographic documents
 Many scales are used in the analysis, from the establishment of the abbeys in a territory to the scale of a building like the tower-entrance of the church of Cormery. These methodological axes have been developed in the research unit CITERES for many years and the 3D technology is now used to go further along in that field. The recording in 3D of the buildings of the abbey of Cormery allows us to work at the scale of the monastery and to produce useful data such as sections or orthoimages of the ground and the walls faces which are afterwards drawn and analysed. The study of these documents, crossed with the other historical sources, allowed us to emphasize the presence of walls older than what we thought and to discover construction elements that had not been recognized earlier and which enhance the debate about the construction date St Paul tower and associated the monastic church

    Effet du sepsis sur les concentrations tissulaires en glutathion

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