202 research outputs found

    Performance evaluation and limitations of a vision system on a reconfigurable/programmable chip

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    This paper presents a survey of the characteristics of a vision system implemented in a reconfigurable/programmable chip (FPGA). System limitations and performance have been evaluated in order to derive specifications and constraints for further vision system synthesis. The system hereby reported has a conventional architecture. It consists in a central microprocessor (CPU) and the necessary peripheral elements for data acquisition, data storage and communications. It has been designed to stand alone, but a link to the programming and debugging tools running in a digital host (PC) is provided. In order to alleviate the computational load of the central microprocessor, we have designed a visual co-processor in charge of the low-level image processing tasks. It operates autonomously, commanded by the CPU, as another system peripheral. The complete system, without the sensor, has been implemented in a single reconfigurable chip as a SOPC. The incorporation of a dedicated visual co-processor, with specific circuitry for low-level image processing acceleration, enhances the system throughput outperforming conventional processing schemes. However, timemultiplexing of the dedicated hardware remains a limiting factor for the achievable peak computing power. We have quantified this effect and sketched possible solutions, like replication of the specific image processing hardware

    Relationship between slack resources and performance: temporal symmetry and duration of effects

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    iterature, the temporal symmetry of this relationship, and the duration of its effects, are still unknown aspects and are the objective of this paper. Design/methodology/approach – To evaluate this effect, an exploratory study has been designed on a sample of 449 Spanish industrial companies over a period of 12 years, assessing the impact of idle resources on economic and financial profitability. By means of hierarchical regressions, the short- term, medium- term and long-term effects of slack resources have been evaluated. Findings – The results show that the impact on performance depends on the type of resource considered. Available slack has a consistent and positive effect on economic profitability in the short term. Other types of slack show persistent effects on performance, but, in the case of the recoverable slack, with a negative sign that contradicts the benefits provided by these resources. Finally, potential slack only has a permanent effect on financial profitability, but the sign changes depending on the economic context under consideration. There are also differences in the duration of the effects according to the type of resources. Originality/value – This paper advances the knowledge about the slack-performance relationship over time that has been scarcely studied

    Las posibilidades de EAD (Encoded Archival Description) 2002 para la descripción archivística multinivel: Un caso concreto de aplicación

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    Se presenta EAD (Encoded Archival Description) versión 2002 como estándar de facto para el tratamiento y difusión de instrumentos tradicionales de descripción archivística. Se analiza, comenta y critica el sistema previsto en EAD para tratar instrumentos de descripción a dos o más niveles. Así, se expone el mecanismo general habilitado y se relaciona con la definición y las cuatro reglas de descripción multinivel enunciadas en la Norma internacional general de descripción archivística ISAD(G); se analizan los niveles que contempla de forma estándar, también comparados con los previstos en ISAD(G), y las diversas posibilidades y alternativas disponibles en EAD en relación con la descripción multinivel; finalmente se critican aquellos aspectos susceptibles de simplificación o mejora. Se cita un caso real de aplicación de EAD 2002 a un instrumento de descripción archivística multinivel: la versión electrónica del Catálogo de Pergaminos del Archivo Municipal de Córdoba

    Identification of arid phases during the last 50 kyr Cal BP from the Fuentillejo maar lacustrine record (Campo de Calatrava Volcanic Field, Spain).

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    Geochemical (element analysis, molecular analysis of organic compounds), physical, palynological, mineralogical and sedimentary facies analysis were performed to characterise the sedimentary record in Fuentillejo maar-lake in the Central Spanish Volcanic Field of Campo de Calatrava, in order to reconstruct the palaeoenvironmental and palaeoclimatic processes which controlled vegetation patterns and deposition of different sedimentary facies. The upper 20 m of core FUENT-1 show variations in clastic input, water chemistry, vegetation and organic fraction sources in the lake throughout the Late Pleistocene and Holocene. The temporal framework provided by14C accelerator mass spectrometry dating allows assigning the sequence to the last 50 cal. ka BP. Arid phases identified in the FUENT-1 sequence are correlated to Heinrich events (HE) and to stadials of the Dansgaard/Oeschger (D/O) cycles. Siliciclastic facies with high magnetic susceptibility values, high Juniperus pollen content, a low Paq index (aquatic macrophysics proxy index), a decrease in the relative percentage of the n-C27 and an increase in the n-C31 alkanes are indicative of arid and colder climatic events related to HE 2, HE 1 and the Younger Dryas (YD). Similar short cold and arid phases during the Holocene were identified at 9.2–8.6, 7.5–7 and 5.5–5 cal. ka BP. In dolomite–mud facies, the pollen data show an increase in the herbs component, mainly – Chenopodiaceae, Artemisia andEphedra – steppe taxa; a low Paq index, a decrease in the relative percentage of the n-C27 alkane and an increase in the n-C31 alkane are also observed. This facies was probably the result of lower lake levels and more saline–alkaline conditions, which can be interpreted as linked to arid–warm periods. These warm and arid phases were more frequent during Marine Isotope Stage (MIS) 3 and the interstadials of MIS 2. HE 4, HE 2, HE 1 and the YD in core FUENT-1 were immediately followed by increases of warm steppe pollen assemblages that document rapid warming similar to the D/O cycles but do not imply increasing humidity in the area. Fuentillejo hydrology is controlled by changes in the atmospheric and oceanic systems that operated on the North Atlantic region at millennial scale during the last 50 cal. ka B

    Identificación de episodios climáticos fríos mediante el registro de susceptibilidad magnética en la secuencia lacustre del maar de Fuentillejo (Ciudad Real).

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    Resumen: El maar de Fuentillejo está localizado en la Región Volcánica Central de Campo de Calatrava (Ciudad Real). Desde su inicio se ha comportado como un sistema cerrado y presenta una potencia total de 142 m de sedimentos lacustres, organizados en 23 unidades sedimentarias. Se ha realizado un estudio de la susceptibilidad magnética y densidad aparente de los sedimentos, mediante un equipo de testificación multisensor Geotek. Para obtener la edad del registro se han efectuado dataciones absolutas mediante radiocarbono, U-Th y con el estudio de polaridad magnética, obteniéndose un modelo de edad que permite datar el sondeo FUENT-1 en torno a los 350 ka. Los datos del registro de susceptibilidad magnética, junto con las dataciones efectuadas, permiten identificar una secuencia de eventos erosivos relacionados con los últimos estadios glaciares (LGM: Ultimo Máximo Glaciar y los estadios isotópicos MIS 6 y 8). El registro de susceptibilidad magnética se encuentra atenuado por procesos de disolución de los óxidos de Fe-Ti. Abstract: The Fuentillejo maar is located in the Central Spanish Volcanic Field of Campo de Calatrava (Ciudad Real). Fuentillejo maar-lake was a closed system where up to 142 m depth of lacustrine sediments were deposited. Magnetic susceptibility and bulk density were measured by a GEOTEK multisensor core logger. The chronological framework was constructed based on radiocarbon and U-Th methods, as well as a detailed study of magnetic polarity, yielding an age model that covers last 350 ka. Intervals with terrigenous sediments correspond to high magnetic susceptibility values. These intervals were correlated with erosive events during the Last Glacial Maximum and the MIS 6 and 8 isotopic stages. The record of magnetic susceptibility is attenuated by disolution processes of Fe-Ti oxides

    Prognosis Relevance of Serum Cytokines in Pancreatic Cancer

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    The overall survival of patients with pancreatic ductal adenocarcinoma is extremely low. Although gemcitabine is the standard used chemotherapy for this disease, clinical outcomes do not reflect significant improvements, not even when combined with adjuvant treatments. There is an urgent need for prognosis markers to be found. The aim of this study was to analyze the potential value of serum cytokines to find a profile that can predict the clinical outcome in patients with pancreatic cancer and to establish a practical prognosis index that significantly predicts patients’ outcomes. We have conducted an extensive analysis of serum prognosis biomarkers using an antibody array comprising 507 human cytokines. Overall survival was estimated using the Kaplan-Meier method. Univariate and multivariate Cox’s proportional hazard models were used to analyze prognosis factors. To determine the extent that survival could be predicted based on this index, we used the leave-one-out cross-validation model. The multivariate model showed a better performance and it could represent a novel panel of serum cytokines that correlates to poor prognosis in pancreatic cancer. B7-1/CD80, EG-VEGF/PK1, IL-29, NRG1-beta1/HRG1-beta1, and PD-ECGF expressions portend a poor prognosis for patients with pancreatic cancer and these cytokines could represent novel therapeutic targets for this disease.The study was fully supported by ROCHE FARMA S.A (ref. H/OH-TAR-10/131 and ref. H/OH-TRR-08/59) and Instituto de Salud Carlos III (ISCIII) (Clinical trial ref. EC08/00009), and the Government of Andalusia Project P12-TIC-2082

    Un repertorio legislativo hipertextual mediante marcado de texto: las Disposiciones Generales del Boletín Oficial de la Comunidad de Madrid

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    Esta comunicación presenta un proyecto en curso encaminado a convertir parte de una legislación autonómica, la de la Comunidad de Madrid, en un conjunto de texto marcado con enlaces hipertextuales, accesible a través de medios diversos (básicamente Internet y CD-ROM u otros soportes físicos). Desarrollado por un equipo del Departamento de Biblioteconomía y Documentación de la Universidad Carlos III de Madrid, parte de la experiencia previa del mismo en la elaboración hipertextual del Código del Mercosur, actualmente un producto comercial en CD-ROM. El objetivo principal del trabajo es la elaboración de una maqueta, en una fase inicial, y la puesta en marcha efectiva, a medio plazo, de las Disposiciones Generales publicadas en el Boletín Oficial de la Comunidad de Madrid como un corpus documental con organización hipertextual accesible a través de World Wide Web. Se describe, inicialmente, el marco teórico en el que se circunscribe el proyecto: el uso de marcado de texto e hipertexto como representaciones adecuadas para un conjunto de documentos legislativos. A continuación, se muestran algunos ejemplos, tanto mediante bases de datos convencionales como hipertextuales, de recopilaciones legislativas ofrecidas por entidades públicas y privadas, tras lo cual se señalan los antecedentes del equipo de trabajo en proyectos similares. Tras mostrar las diferentes fases previas del proyecto (determinación de objetivos, análisis del corpus, definición de estructuras de almacenamiento y concepción teórica del marcado de texto con enlaces), se muestran las etapas de desarrollo, para concluir con el estado actual del proyecto y las previsiones de futuro.Comunidad de Madrid, Consejería de Educación (proyecto 06/0045/99

    Bioelectronics-on-a-chip for cardio myoblast proliferation enhancement using electric field stimulation

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    Background: Cardio myoblast generation from conventional approaches is laborious and time-consuming. We present a bioelectronics on-a-chip for stimulating cells cardio myoblast proliferation during culture. Method: The bioelectronics chip fabrication methodology involves two different process. In the first step, an aluminum layer of 200 nm is deposited over a soda-lime glass substrate using physical vapor deposition and selectively removed using a Q-switched Nd:YVO4 laser to create the electric tracks. To perform the experiments, we developed a biochip composed of a cell culture chamber fabricated with polydimethylsiloxane (PDMS) with a glass coverslip or a cell culture dish placed over the electric circuit tracks. By using such a glass cover slip or cell culture dish we avoid any toxic reactions caused by electrodes in the culture or may be degraded by electrochemical reactions with the cell medium, which is crucial to determine the effective cell-device coupling. Results: The chip was used to study the effect of electric field stimulation of Rat ventricular cardiomyoblasts cells (H9c2). Results shows a remarkable increase in the number of H9c2 cells for the stimulated samples, where after 72 h the cell density double the cell density of control samples. Conclusions: Cell proliferation of Rat ventricular cardiomyoblasts cells (H9c2) using the bioelectronics-on-a-chip was enhanced upon the electrical stimulation. The dependence on the geometrical characteristics of the electric circuit on the peak value and homogeneity of the electric field generated are analyzed and proper parameters to ensure a homogeneous electric field at the cell culture chamber are obtained. It can also be observed a high dependence of the electric field on the geometry of the electrostimulator circuit tracks and envisage the potential applications on electrophysiology studies, monitoring and modulate cellular behavior through the application of electric fieldsThis work was partially supported by Mineco through the projects FIS 2015–71933-REDT and RTI 2018–097063-B-I00, Consellería de Educación Program for Development of a Strategic Grouping in Materials – AeMAT Grant No. ED431E2018/08, Xunta de Galicia ref. ED431B2017/64. Xunta de Galicia, Spain, under Galician Programme for Research Innovation and Growth 2011–2015 (I2C Plan)S
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