409 research outputs found
A Geometric Feature-Based Algorithm for the Virtual Reading of Closed Historical Manuscripts
X-ray Computed Tomography (CT), a commonly used technique in a wide variety of research fields, nowadays represents a unique and powerful procedure to discover, reveal and preserve a fundamental part of our patrimony: ancient handwritten documents. For modern and well-preserved ones, traditional document scanning systems are suitable for their correct digitization, and, consequently, for their preservation; however, the digitization of ancient, fragile and damaged manuscripts is still a formidable challenge for conservators. The X-ray tomographic approach has already proven its effectiveness in data acquisition, but the algorithmic steps from tomographic images to real page-by-page extraction and reading are still a difficult undertaking. In this work, we propose a new procedure for the segmentation of single pages from the 3D tomographic data of closed historical manuscripts, based on geometric features and flood fill methods. The achieved results prove the capability of the methodology in segmenting the different pages recorded starting from the whole CT acquired volume
Bioinformatics and mathematical modelling in the study of receptor-receptor interactions and receptor oligomerization: focus on adenosine receptors.
none8sìThe concept of intra-membrane receptor-receptor interactions (RRIs) between different types of G protein-coupled receptors (GPCRs) and evidence for their existence was introduced by Agnati and Fuxe in 1980/81 through the biochemical analysis of the effects of neuropeptides on the binding characteristics of monoamine receptors in membrane preparations from discrete brain regions and functional studies of the interactions between neuropeptides and monoamines in the control of specific functions such as motor control and arterial blood pressure control in animal models.
Whether GPCRs can form high-order structures is still a topic of an intense debate. Increasing evidence, however, suggests that the hypothesis of the existence of high-order receptor oligomers is correct. A fundamental consequence of the view describing GPCRs as interacting structures, with the likely formation at the plasma membrane of receptor aggregates of multiple receptors (Receptor Mosaics) is that it is no longer possible to describe signal transduction simply as the result of the binding of the chemical signal to its receptor, but rather as the result of a filtering/integration of chemical signals by the Receptor Mosaics (RMs) and membrane-associated proteins. Thus, in parallel with experimental research, significant efforts were spent in bioinformatics and mathematical modelling. We review here the main approaches that have been used to assess the interaction interfaces allowing the assembly of GPCRs and to shed some light on the integrative functions emerging from the complex behaviour of these RMs. Particular attention was paid to the RMs generated by adenosine A(2A), dopamine D-2, cannabinoid CB1, and metabotropic glutamate mGlu(5) receptors (A(2A). D-2, CB1, and mGlu(5), respectively), and a possible approach to model the interplay between the D-2-A(2A)-CB1 and D-2-A(2A)-mGlu(5) trimers is proposed. This article is part of a Special Issue entitled: "Adenosine Receptors". (C) 2010 Elsevier B.V. All rights reserved.openD. GUIDOLIN; F. CIRUELA; S. GENEDANI; M. GUESCINI; C. TORTORELLA; G. ALBERTIN; K. FUXE; L.F. AGNATID., Guidolin; F., Ciruela; S., Genedani; Guescini, Michele; C., Tortorella; G., Albertin; K., Fuxe; L. F., Agnat
X‐ray Tomography Unveils the Construction Technique of Un‐Montu’s Egyptian Coffin (Early 26th Dynasty)
The Bologna Archaeological Museum, in cooperation with prestigious Italian universities, institutions, and independent scholars, recently began a vast investigation programme on a group of Egyptian coffins of Theban provenance dating to the first millennium BC, primarily the 25th–26th Dynasty (c. 746–525 BC). Herein, we present the results of the multidisciplinary investigation car-ried out on one of these coffins before its restoration intervention: the anthropoid wooden coffin of Un‐Montu (Inv. MCABo EG1960). The integration of radiocarbon dating, wood species identifica-tion, and CT imaging enabled a deep understanding of the coffin’s wooden structure. In particular, we discuss the results of the tomographic investigation performed in situ. The use of a transportable X‐ray facility largely reduced the risks associated with the transfer of the large object (1.80 cm tall) out of the museum without compromising image quality. Thanks to the 3D tomographic imaging, the coffin revealed the secrets of its construction technique, from the rational use of wood to the employment of canvas (incamottatura), from the use of dowels to the assembly procedure
Multi-layer coating development for XEUS
Graded depth multi-layer coatings have the potential to optimise the performance of X-ray reflective surfaces for improved energy response. A study of deposition techniques on silicon substrates representative of the XEUS High Performance Pore Optics (HPO) technology has been carried out. Measurements at synchrotron radiation facilities have been used to confirm the excellent performance improvements achievable with Mo/Si and W/Si multilayers. Future activities that will be necessary to implement such coatings in the HPO assembly sequence are highlighted. Further coating developments that may allow an optimisation of the XEUS effective area in light of potential changes to science requirements and telescope configurations are also identified. Finally an initial measurement of effects of radiation damage within the multilayers is reported
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