74 resultados para Integrated optical
em Université de Lausanne, Switzerland
Resumo:
The pigments and the plasters of the Roman frescoes discovered at the House of Diana (Cosa, Grosseto, Italy) were analysed using non-destructive and destructive mineralogical and chemical techniques. The characterization of both pigments and plasters was performed through optical microscopy, scanning electron microscopy and electron microprobe analysis. The pigments were identified by Raman spectroscopy and submitted to stable isotope analysis. The results were integrated with the archaeological data in order to determine and reconstruct the provenance, trade patterns and the employment of the raw materials used for the elaboration of the frescoes.
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The kinetics of binding of a glycolipid-anchored protein (the promastigote surface protease, PSP) to planar lecithin bilayers is studied by an integrated optics technique, in which the bilayer membrane is supported on an optical wave guide and the phase velocities of guided light modes in the wave guide are measured. From these velocities, the optical parameters of the membrane and PSP layers deposited on the waveguide are determined, yielding in particular the mass of PSP bound to the membrane, which is followed in real time. From a comparison of the binding rates of PSP and PSP from which the lipid moiety has been removed, it is shown that the lipid moiety plays a key role in anchoring the protein to the membrane. Specific and nonspecific binding of antibodies to membrane-anchored PSP is also investigated. As little as a fifth of a monolayer of PSP is sufficient to suppress the appreciable nonspecific binding of antibodies to the membrane.
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INTRODUCTION: The Swiss health care system is characterized by its decentralized structure and high degree of local autonomy. Ambulatory care is provided by physicians working mainly independently in individual private practices. However, a growing part of primary care is provided by networks of physicians and health maintenance organizations (HMOs) acting on the principles of gatekeeping. TOWARDS INTEGRATED CARE IN SWITZERLAND: The share of insured choosing an alternative (managed care) type of basic health insurance and therefore restrict their choice of doctors in return for lower premiums increased continuously since 1990. To date, an average of one out of eight insured person in Switzerland, and one out of three in the regions in north-eastern Switzerland, opted for the provision of care by general practitioners in one of the 86 physician networks or HMOs. About 50% of all general practitioners and more than 400 other specialists have joined a physician networks. Seventy-three of the 86 networks (84%) have contracts with the healthcare insurance companies in which they agree to assume budgetary co-responsibility, i.e., to adhere to set cost targets for particular groups of patients. Within and outside the physician networks, at regional and/or cantonal levels, several initiatives targeting chronic diseases have been developed, such as clinical pathways for heart failure and breast cancer patients or chronic disease management programs for patients with diabetes. CONCLUSION AND IMPLICATIONS: Swiss physician networks and HMOs were all established solely by initiatives of physicians and health insurance companies on the sole basis of a healthcare legislation (Swiss Health Insurance Law, KVG) which allows for such initiatives and developments. The relevance of these developments towards more integration of healthcare as well as their implications for the future are discussed.
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To sense myriad environmental odors, animals have evolved multiple, large families of divergent olfactory receptors. How and why distinct receptor repertoires and their associated circuits are functionally and anatomically integrated is essentially unknown. We have addressed these questions through comprehensive comparative analysis of the Drosophila olfactory subsystems that express the ionotropic receptors (IRs) and odorant receptors (ORs). We identify ligands for most IR neuron classes, revealing their specificity for select amines and acids, which complements the broader tuning of ORs for esters and alcohols. IR and OR sensory neurons exhibit glomerular convergence in segregated, although interconnected, zones of the primary olfactory center, but these circuits are extensively interdigitated in higher brain regions. Consistently, behavioral responses to odors arise from an interplay between IR- and OR-dependent pathways. We integrate knowledge on the different phylogenetic and developmental properties of these receptors and circuits to propose models for the functional contributions and evolution of these distinct olfactory subsystems.
Resumo:
Signature databases are vital tools for identifying distant relationships in novel sequences and hence for inferring protein function. InterPro is an integrated documentation resource for protein families, domains and functional sites, which amalgamates the efforts of the PROSITE, PRINTS, Pfam and ProDom database projects. Each InterPro entry includes a functional description, annotation, literature references and links back to the relevant member database(s). Release 2.0 of InterPro (October 2000) contains over 3000 entries, representing families, domains, repeats and sites of post-translational modification encoded by a total of 6804 different regular expressions, profiles, fingerprints and Hidden Markov Models. Each InterPro entry lists all the matches against SWISS-PROT and TrEMBL (more than 1,000,000 hits from 462,500 proteins in SWISS-PROT and TrEMBL). The database is accessible for text- and sequence-based searches at http://www.ebi.ac.uk/interpro/. Questions can be emailed to interhelp@ebi.ac.uk.
Resumo:
In the investigation of thin films of transition metal nitrides, an essential role is played by the accurate determination of their chemical composition. Actually the chemical composition depends on the deposition parameters and influences the optical properties. These relations are illustrated in thin films of TiNx and (Ti1-yVy)N-x deposited by reactive magnetron sputtering from composite targets of the elements. By variation of the nitrogen partial pressure and the target composition, different samples have been obtained. The chemical composition has been measured by electron probe microanalysis at low irradiation voltages. The optical properties are evaluated by ex-situ ellipsometry. Using the screened Drude model, they are correlated with the differences in composition. Adding vanadium or nitrogen in Ti-N is shown to have the same effect on the optical properties.
Resumo:
OBJECTIVE: The purpose of this study was to compare the use of different variables to measure the clinical wear of two denture tooth materials in two analysis centers. METHODS: Twelve edentulous patients were provided with full dentures. Two different denture tooth materials (experimental material and control) were placed randomly in accordance with the split-mouth design. For wear measurements, impressions were made after an adjustment phase of 1-2 weeks and after 6, 12, 18, and 24 months. The occlusal wear of the posterior denture teeth of 11 subjects was assessed in two study centers by use of plaster replicas and 3D laser-scanning methods. In both centers sequential scans of the occlusal surfaces were digitized and superimposed. Wear was described by use of four different variables. Statistical analysis was performed after log-transformation of the wear data by use of the Pearson and Lin correlation and by use of a mixed linear model. RESULTS: Mean occlusal vertical wear of the denture teeth after 24 months was between 120μm and 212μm, depending on wear variable and material. For three of the four variables, wear of the experimental material was statistically significantly less than that of the control. Comparison of the two study centers, however, revealed correlation of the wear variables was only moderate whereas strong correlation was observed among the different wear variables evaluated by each center. SIGNIFICANCE: Moderate correlation was observed for clinical wear measurements by optical 3D laser scanning in two different study centers. For the two denture tooth materials, wear measurements limited to the attrition zones led to the same qualitative assessment.
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An inflammasome is a multiprotein complex that serves as a platform for caspase-1 activation and caspase-1-dependent proteolytic maturation and secretion of interleukin-1β (IL-1β). Though a number of inflammasomes have been described, the NLRP3 inflammasome is the most extensively studied but also the most elusive. It is unique in that it responds to numerous physically and chemically diverse stimuli. The potent proinflammatory and pyrogenic activities of IL-1β necessitate that inflammasome activity is tightly controlled. To this end, a priming step is first required to induce the expression of both NLRP3 and proIL-1β. This event renders the cell competent for NLRP3 inflammasome activation and IL-1β secretion, and it is highly regulated by negative feedback loops. Despite the wide array of NLRP3 activators, the actual triggering of NLRP3 is controlled by integration a comparatively small number of signals that are common to nearly all activators. Minimally, these include potassium efflux, elevated levels of reactive oxygen species (ROS), and, for certain activators, lysosomal destabilization. Further investigation of how these and potentially other as yet uncharacterized signals are integrated by the NLRP3 inflammasome and the relevance of these biochemical events in vivo should provide new insight into the mechanisms of host defense and autoinflammatory conditions.
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An active learning method is proposed for the semi-automatic selection of training sets in remote sensing image classification. The method adds iteratively to the current training set the unlabeled pixels for which the prediction of an ensemble of classifiers based on bagged training sets show maximum entropy. This way, the algorithm selects the pixels that are the most uncertain and that will improve the model if added in the training set. The user is asked to label such pixels at each iteration. Experiments using support vector machines (SVM) on an 8 classes QuickBird image show the excellent performances of the methods, that equals accuracies of both a model trained with ten times more pixels and a model whose training set has been built using a state-of-the-art SVM specific active learning method
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Recrystallization rims are a common feature of zircon crystals that underwent metamorphism. We present a microstructural and microchemical study of partially recrystallized zircon grains collected in polymetamorphic migmatites (Valle d'Arbedo, Ticino, Switzerland). The rims are bright in cathodo-luminescence (CL), with sharp and convex contacts characterized by inward-penetrating embayments transgressing igneous zircon cores. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) data and transmission electron microscopy (TEM) imaging indicate that the rims are chemically and microstructurally different from the cores. The rims are strongly depleted in REE, with concentrations up to two orders of magnitude lower than in the cores, indicating a significant loss of REE during zircon recrystallization. Enrichment in non-formula elements, such as Ca, has not been observed in the rims. The microstructure of zircon cores shows a dappled intensity at and below the 100 nm scale, possibly due to radiation damage. Other defects such as pores and dislocations are absent in the core except at healed cracks. Zircon rims are mostly dapple-free, but contain nanoscale pores and strain centers, interpreted as fluid inclusions and chemical residues, respectively. Sensitive high-resolution ion microprobe (SHRIMP) U-Pb ages show that the recrystallization of the rims took place >200 Ma ago when the parent igneous zircon was not metamict. The chemical composition and the low-Ti content of the rims indicate that they form at sub-solidus temperatures (550-650 degrees C). Recrystallization rims in Valle d'Arbedo zircon are interpreted as the result of the migration of chemical reaction fronts in which fluid triggered in situ and contemporaneous interface-coupled dissolution-reprecipitation mechanisms. This study indicates that strong lattice strain resulting from the incorporation of a large amount of impurities and structural defects is not a necessary condition for zircon to recrystallize. Our observations suggest that the early formation of recrystallization rims played a major role in preserving zircon from the more recent Alpine metamorphic overprint.