962 resultados para Digital-to-analog converters


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L'objectiu d'aquest estudi és presentar una investigació d'alt nivell sobre el contínuum físico-conceptual que ocupen tant les biblioteques digitals com les biblioteques físiques.

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In 1903, the eastern slope of Turtle Mountain (Alberta) was affected by a 30 M m3-rockslide named Frank Slide that resulted in more than 70 casualties. Assuming that the main discontinuity sets, including bedding, control part of the slope morphology, the structural features of Turtle Mountain were investigated using a digital elevation model (DEM). Using new landscape analysis techniques, we have identified three main joint and fault sets. These results are in agreement with those sets identified through field observations. Landscape analysis techniques, using a DEM, confirm and refine the most recent geology model of the Frank Slide. The rockslide was initiated along bedding and a fault at the base of the slope and propagated up slope by a regressive process following a surface composed of pre-existing discontinuities. The DEM analysis also permits the identification of important geological structures along the 1903 slide scar. Based on the so called Sloping Local Base Level (SLBL) an estimation was made of the present unstable volumes in the main scar delimited by the cracks, and around the south area of the scar (South Peak). The SLBL is a method permitting a geometric interpretation of the failure surface based on a DEM. Finally we propose a failure mechanism permitting the progressive failure of the rock mass that considers gentle dipping wedges (30°). The prisms or wedges defined by two discontinuity sets permit the creation of a failure surface by progressive failure. Such structures are more commonly observed in recent rockslides. This method is efficient and is recommended as a preliminary analysis prior to field investigation.

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El sistema desarrollado en este trabajo permite la detección de fatiga del músculo de un paciente. Las señales electromiográficas generadas por el músculo son detectadas mediante electrodos superficiales, que sirven de entrada al circuito hacia los diferentes canales de entrada. Tras una primera etapa de amplificación, las señales son filtradas por un filtro pasabanda. Las señales acondicionadas se digitalizan mediante un conversor analógico digital que está conectado a un microcontrolador. Éste establece la comunicación con el PC enviándole los datos a través del puerto serie. Finalmente, mediante un programa implementado en Labview se procesan los datos y se determina la existencia o no de fatiga muscular.

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This paper reports on: (a) new primary source evidence on; and (b) statistical and econometric analysis of high technology clusters in Scotland. It focuses on the following sectors: software, life sciences, microelectronics, optoelectronics, and digital media. Evidence on a postal and e-mailed questionnaire is presented and discussed under the headings of: performance, resources, collaboration & cooperation, embeddedness, and innovation. The sampled firms are characterised as being small (viz. micro-firms and SMEs), knowledge intensive (largely graduate staff), research intensive (mean spend on R&D GBP 842k), and internationalised (mainly selling to markets beyond Europe). Preliminary statistical evidence is presented on Gibrat’s Law (independence of growth and size) and the Schumpeterian Hypothesis (scale economies in R&D). Estimates suggest a short-run equilibrium size of just 100 employees, but a long-run equilibrium size of 1000 employees. Further, to achieve the Schumpeterian effect (of marked scale economies in R&D), estimates suggest that firms have to grow to very much larger sizes of beyond 3,000 employees. We argue that the principal way of achieving the latter scale may need to be by takeovers and mergers, rather than by internally driven growth.

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Report for the scientific sojourn carried out at the Uppsala Universitet, Sweden, from April to July the 2007. Two series of analogue models are used to explore ductile-frictional contrasts of the basal décollement in the development of oblique and transverse structures simultaneously to thin-skinned shortening. These models simulate the evolution of the Central External Sierras (Southern Pyrenees, Spain), which constitute the frontal emerging part of the southernmost Pyrenean thrust sheet. They are characterized by the presence of transverse N-S to NW-SE anticlines, which are perpendicular to the Pyrenean structural trend and developed in the hangingwall of the Santo Domingo thrust system, detaching on an unevenly distributed Triassic materials (evaporitic-dolomitic interfingerings). Model setup performs a décollement made by three patches of silicone neighbouring pure brittle sand. Model series A test the thickness ratio between overburden and décollement. Model series B test the width of frictional detachment areas. Model results show how deformation reaches further in areas detached on ductile layer whereas frictional décollement areas assimilate the strain by means of an additional uplift. This replicates the structural style of Central External Sierras: higher structural relief of N-S anticlines with regard to orogen-parallel structures, absence of a representative ductile décollement in the core, tilting towards the orogen and foreland-side closure not thrusted by the frontal emerging South-Pyrenean thrust.

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The recent identification and molecular characterization of tumor-associated antigens recognized by tumor-reactive CD8+ T lymphocytes has led to the development of antigen-specific immunotherapy of cancer. Among other approaches, clinical studies have been initiated to assess the in vivo immunogenicity of tumor antigen-derived peptides in cancer patients. In this study, we have analyzed the CD8+ T cell response of an ocular melanoma patient to a vaccine composed of four different tumor antigen-derived peptides administered simultaneously in incomplete Freund's adjuvant (IFA). Peptide NY-ESO-1(157-165) was remarkably immunogenic and induced a CD8+ T cell response detectable ex vivo at an early time point of the vaccination protocol. A CD8+ T cell response to the peptide analog Melan-A(26-35 A27L) was also detectable ex vivo at a later time point, whereas CD8+ T cells specific for peptide tyrosinase(368-376) were detected only after in vitro peptide stimulation. No detectable CD8+ T cell response to peptide gp100(457-466) was observed. Vaccine-induced CD8+ T cell responses declined rapidly after the initial response but increased again after further peptide injections. In addition, tumor antigen-specific CD8+ T cells were isolated from a vaccine injection site biopsy sample. Importantly, vaccine-induced CD8+ T cells specifically lysed tumor cells expressing the corresponding antigen. Together, these data demonstrate that simultaneous immunization with multiple tumor antigen-derived peptides can result in the elicitation of multiepitope-directed CD8+ T cell responses that are reactive against antigen-expressing tumors and able to infiltrate antigen-containing peripheral sites.

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We studied whether readiness to change predicts alcohol consumption (drinks per day) 3 months later in 267 medical inpatients with unhealthy alcohol use. We used 3 readiness to change measures: a 1 to 10 visual analog scale (VAS) and two factors of the Stages of Change Readiness and Treatment Eagerness Scale: Perception of Problems (PP) and Taking Action (TA). Subjects with the highest level of VAS-measured readiness consumed significantly fewer drinks 3 months later [Incidence rate ratio (IRR) and 95% confidence interval (CI): 0.57 (0.36, 0.91) highest vs. lowest tertile]. Greater PP was associated with more drinking [IRR (95%CI): 1.94 (1.02, 3.68) third vs. lowest quartile]. Greater TA scores were associated with less drinking [IRR (95%CI): 0.42 (0.23, 0.78) highest vs. lowest quartile]. Perception of Problems' association with more drinking may reflect severity rather than an aspect of readiness associated with ability to change; high levels of Taking Action appear to predict less drinking. Although assessing readiness to change may have clinical utility, assessing the patient's planned actions may have more predictive value for future improvement in alcohol consumption.

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Cooperation between libraries is a universal language spoken in different dialects. In 1996 the libraries of the state-funded universities and the National Library of Catalonia (Spain) formed the Consortium of Academic Libraries of Catalonia (CBUC) to act as a channel for cooperation. The organization and activities of CBUC are an example of how this universal language has been adapted to the specific characteristics of the Libraries of Catalonia. Catalonia is an autonomous region of Spain with 7 million inhabitants with its own language, history and traditions and with a strong feeling of own identity that facilitates the cooperation. Thanks to this (and also to the hard work of the member libraries), since then, CBUC has created a union catalogue, an interlibrary lending program, the Digital Library of Catalonia, a cooperative store, different cooperatives repositories and other cooperation programs. One of these cooperatives repositories is RACO (Catalan Journals in Open Access, www.raco.cat) where can be consulted, in open access, the full-text articles of scientific, cultural and scholar Catalan journals. The main purpose of RACO is to increase the visibility and searches of the journals included and to spread the scientific and academic production published in Catalonia. This purpose makes specific in three aims: encourage the electronic edition of Catalan journals; be the interface that allows the whole search of all the journals and provide the instruments for its preservation. There are currently 244 journals in RACO, that includes more than 85.000 articles (80% in OA) from 50 publishing institutions. Since it got into operation it has had more than 4 millions of queries. These 244 journals offer the full-text of all the published issues. Nevertheless, some journal can have a delay between the introduction of the table of contents and the full-text for the recent issues. From 2005 we have a plan of retrospective digitization that has allowed to digitize more than 350.000 pages of back issues. The RACO repository works with the open source program OJS (Open Journal Systems, http://pkp.sfu.ca/ojs/) and uses Dublin Core Metadata and the interoperability protocol created by Open Archives Initiative (OAI) which allows to increase the visibility of the articles published in journals offering oneself together with other international repositories.

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Red blood cell (RBC) parameters such as morphology, volume, refractive index, and hemoglobin content are of great importance for diagnostic purposes. Existing approaches require complicated calibration procedures and robust cell perturbation. As a result, reference values for normal RBC differ depending on the method used. We present a way for measuring parameters of intact individual RBCs by using digital holographic microscopy (DHM), a new interferometric and label-free technique with nanometric axial sensitivity. The results are compared with values achieved by conventional techniques for RBC of the same donor and previously published figures. A DHM equipped with a laser diode (lambda = 663 nm) was used to record holograms in an off-axis geometry. Measurements of both RBC refractive indices and volumes were achieved via monitoring the quantitative phase map of RBC by means of a sequential perfusion of two isotonic solutions with different refractive indices obtained by the use of Nycodenz (decoupling procedure). Volume of RBCs labeled by membrane dye Dil was analyzed by confocal microscopy. The mean cell volume (MCV), red blood cell distribution width (RDW), and mean cell hemoglobin concentration (MCHC) were also measured with an impedance volume analyzer. DHM yielded RBC refractive index n = 1.418 +/- 0.012, volume 83 +/- 14 fl, MCH = 29.9 pg, and MCHC 362 +/- 40 g/l. Erythrocyte MCV, MCH, and MCHC achieved by an impedance volume analyzer were 82 fl, 28.6 pg, and 349 g/l, respectively. Confocal microscopy yielded 91 +/- 17 fl for RBC volume. In conclusion, DHM in combination with a decoupling procedure allows measuring noninvasively volume, refractive index, and hemoglobin content of single-living RBCs with a high accuracy.

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The transmembrane water movements during cellular processes and their relationship to ionic channel activity remain largely unknown. As an example, in epithelial cells it was proposed that the movement of water could be directly linked to cystic fibrosis transmembrane conductance regulator (CFTR) protein activity through a cAMP-stimulated aqueous pore, or be dependent on aquaporin. Here, we used digital holographic microscopy (DHM) an interferometric technique to quantify in situ the transmembrane water fluxes during the activity of the epithelial chloride channel, CFTR, measured by patch-clamp and iodide efflux techniques. We showed that the water transport measured by DHM is fully inhibited by the selective CFTR blocker CFTRinh172 and is absent in cells lacking CFTR. Of note, in cells expressing the mutated version of CFTR (F508del-CFTR), which mimics the most common genetic alteration encountered in cystic fibrosis, we also show that the water movement is profoundly altered but restored by pharmacological manipulation of F508del-CFTR-defective trafficking. Importantly, whereas activation of this endogenous water channel required a cAMP-dependent stimulation of CFTR, activation of CFTR or F508del-CFTR by two cAMP-independent CFTR activators, genistein and MPB91, failed to trigger water movements. Finally, using a specific small-interfering RNA against the endogenous aquaporin AQP3, the water transport accompanying CFTR activity decreased. We conclude that water fluxes accompanying CFTR activity are linked to AQP3 but not to a cAMP-stimulated aqueous pore in the CFTR protein.

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We demonstrate that the step of DNA strand exchange during RecA-mediated recombination reaction can occur equally efficiently in the presence or absence of ATP hydrolysis. The polarity of strand exchange is the same when instead of ATP its non-hydrolyzable analog adenosine-5'-O-(3-thiotriphosphate) is used. We show that the ATP dependence of recombination reaction is limited to the post-exchange stages of the reactions. The low DNA affinity state of RecA protomers, induced after ATP hydrolysis, is necessary for the dissociation of RecA-DNA complexes at the end of the reaction. This dissociation of RecA from DNA is necessary for the release of recombinant DNA molecules from the complexes formed with RecA and for the recycling of RecA protomers for another round of the recombination reaction.

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El Consorci de Biblioteques Universitàries de Catalunya (CBUC) va ser creat el 1996 amb l'objectiu de fer i mantenir el catàleg col·lectiu de les universitats de Catalunya (CCUC) però aviat va ampliar les seves activitats amb el préstec interbibliotecari i les compres conjuntes d'informació electrònica. Aquesta darrera activitat va iniciar-se a finals de 1997 quan el CBUC va presentar als vicerectors de recerca de les universitats públiques de Catalunya el projecte de comprar bases de dades de manera consorciada. Aquests van estar-hi d'acord i van manifestar el seu interès de que en les compres conjuntes també s'incloguessin revistes electròniques. El CBUC va decidir englobar aquestes activitats sota el nom Biblioteca Digital de Catalunya (BDC) la qual naixia amb la "finalitat de proporcionar un conjunt nuclear comú d'informació electrònica per a la totalitat dels usuaris de les biblioteques del CBUC". A finals de 1998 el projecte de la BDC es va presentar a la Generalitat de Catalunya i es va obtenir un finançament per al projecte que cobria el període 1999-2001. Des de llavors la BDC ha passat per almenys tres fases: Una de formació, 1999-2001, que es va iniciar amb un ajut del llavors Departament d'Universitats, Recerca i Societat de la Informació (DURSI) de la Generalitat de Catalunya, ajut que es va traduir en una inversió de 180.000€/any i que va permetre l'inici de subscripcions conjuntes, principalment bases de dades. Una de creixement, 2002-2004, realitzada a partir d'un increment de l'ajut del DURSI, ajut que s'usa com a "capital llavor" per subscriure de forma especial revistes. En aquest moment la BDC s'amplia a universitats no membres del CBUC. Una d'estabilització, 2005-2009, en la que s'han fet algunes compres per a una part de les universitats (i no per a totes com fins llavors) i s'han iniciat alguns intents d'estendre la BDC a altres institucions de recerca. L'article caracteritza les diferents fases i mostra les causes de la seva evolució. Finalment, s'exposen els principals assoliments de la BDC així com els reptes de futur més immediats.

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PADICAT is the web archive created in 2005 in Catalonia (Spain ) by the Library of Catalonia (BC ) , the National Library of Catalonia , with the aim of collecting , processing and providing permanent access to the digital heritage of Catalonia . Its harvesting strategy is based on the hybrid model ( of massive harvesting . SPA top level domain ; selective compilation of the web site output of Catalan organizations; focused harvesting of public events) . The system provides open access to the whole collection , on the Internet . We consider necessary to complement the current search for new and visualization software with open source software tool, CAT ( Curator Archiving Tool) , composed by three modules aimed to effectively managing the processes of human cataloguing ; to publish directories where the digital resources and special collections ; and to offer statistical information of added value to end users. Within the framework of the International Internet Preservation Consortium meeting ( Vienna 2010) , the progress in the development of this new tool, and the philosophy that has motivated his design, are presented to the international community.

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Purpose:to describe the clinical features in a five generations family segregating autosomal dominant retinitis pigmentosa and to identify the causative gene Patient and Methods:Twenty five individuals of a large five-generation family originating from Western Switzerland were ascertained for phenotypic and genotypic characterization. Ophthalmologic evaluations included color vision testing, Goldman perimetry and digital fundus photography. Some patients had autofluorescence (AF) imaging, ocular coherence tomography (OCT) and ISCEV-standard full-field electroretinography (ERG). Blood samples were collected from 10 affected (4 to 70 years of age) and 15 unaffected members after informed consent. DNA was isolated and exons and intron-exons junctions of known adRP genes were sequenced using a Big Dye sequencing kit 1.1. Results:Age of onset of nightblindness and severity of progression of the disease was variable between members of the family. Some patients had early onset of nightblindess aged 3, others at mid-twenties. Most patients had visual acuity above 0.6 for the first 4 decades. Two older patients still had good vision (0.4) in their seventies. Myopia (range: -2 to -5) was noticed in most affected subjects. Fundus findings showed areas of atrophy along the arcades. The AF imaging showed a large high density ring bilaterally. A T494M change was found in exon 11 of PRPF3 gene. The change segregates with the disease in the family. Conclusion: A mutation in the PRPF3 gene is rare compared with other genes causing ADRP. Although a T494M change has been reported, our family is the first one with a variable expressivity. Mutations in PRPF3 gene can cause a variable phenotype of ADRP unlike the previously described Danish and English families. Our report gives a better understanding as to the phenotype/genotype description of ADRP due to PRPF3 mutation.

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La plataforma d’e-learning: COMalaWEB és una eina multimedia de suport a l’estudi, l’experimentació i l’adquisició de tècniques d’autoaprenentatge. COMalaWEB s’ofereix com a punt de trobada entre estudiants, professors i altres professionals relacionats amb el mon de les telecomunicacions i/o de la docència universitària. Mitjançant el present projecte s’ha dut a terme la consolidació de la plataforma COMalaWEB com a eina WWW d'autoaprenentatge per a l'EEES (Estudis de Bachelor i de Màster): Dins de la plataforma s’hi ha integrat un Laboratori Virtual per a comunicacions analògiques i digitals (LaViCAD) que ofereix activitats experimentals amb un gran ventall de possibilitats que van des de les demostracions teòriques fins a l’emulació de sistemes de comunicacions quotidians com per exemple la televisió digital o el sistema Wifi dels sistemes WLAN. L’altre gran component de la plataforma es la base de dades de continguts empaquetada en unitats bàsiques anomenades objectes de coneixement, organitzada en cursos, integren tant continguts teòrics com un conjunt d’exercicis proposats per a aprofundir cadascun dels temes tractats. Amb l’actual projecte s’ha treballat en les següents línies d’actuació: - Integració dels simuladors del laboratori LAVICAD a la plataforma d’autoaprenentatge. - Creació de base de dades de recursos docents basats en paquets SCORM per a oferir materials docents de tipus teòric i col·leccions d’exercicis resolts en el marc de les diferents assignatures participants en el projecte. - Creació de base de dades de tipus qüestionari per a oferir exercicis a treballar en el marc de les diferents assignatures participants en el projecte. - Inserció de metodologies docents basades en els anteriors recursos en diferents assignatures d’estudis d’enginyeria i de màster.