2,140 research outputs found

    Texture-based Classification for the Automatic Rating of the Perivascular Spaces in Brain MRI

    Get PDF
    Los espacios perivasculares (EVP) se relacionan con una cognición deficiente, depresión en la edad avanzada, enfermedad de Parkinson, inflamación, hipertensión y enfermedad de pequeños vasos cerebrales, cuando están agrandados y son visibles en imágenes de resonancia magnética (MRI). En este artículo exploramos cómo clasificar la densidad del PVS agrandado en los ganglios basales (BG) mediante la descripción de la textura de la RM cerebral estructural. La textura de la región BG se describe mediante estadísticas de primer orden y características derivadas de la matriz de co-ocurrencia, ambas computadas a partir de la imagen original y los coeficientes producidos por la transformada de wavelet discreta (WSF y WCF, respectivamente), y patrones binarios locales (LBP). Los resultados experimentales con un clasificador de Máquina de vectores de soporte (SVM) muestran que WCF logra una precisión del 80.03%

    The Present and Future of Academical Dress in Spain: Catalogue of Guidelines on the Use of Academical Dress and its Colours in Spanish Universities

    Get PDF
    The Association for the Study of University Protocol, founded in 1997, brings together professionals in Spanish universities who are responsible for the organization of academic ceremonies, university traditions, as well as the new activities derived from those traditions which maintain the university in its place. In the course of the activities of the Association it soon became apparent that it was necessary to understand with the greatest possible degree of accuracy ways in which academical dress was used and that it was important to establish a catalogue of suggestions on its use and of the current use of colours. The fruits of this labour, co-ordinated by the authors of this article, were elaborated in such a Catalogue. [Excerpt from Introduction]

    The cosmic dawn and the epoch of reionization

    Get PDF
    In this chapter we briefly describe the physics behind the HI 21 cm line in terms of the interplay of the HI gas with the ionized plasma and the Cosmic Microwave Background, and the different phases the system undergoes as the ambient density and UV background evolve with cosmological time. We also address the problematics associated to the metal enrichment of the IGM and the implications for the models of galaxy formation and evolution. We briefly discuss possible synergies with other reionization probes like E-ELT, JWST and ALMA, and conclude by listing a number of cosmological scenarios describing some type of energetic injection in the Universe, scenarios to whose understanding SKA should be able to (at least partially) contribute.The authors acknowledge partial support from the Spanish Ministerio de Economía y Competitividad (MICINN) through projects AYA2013-48623-C2-2, AYA2007-68058-C03-01, AYA2010-21766-C03-02, AYA2012-30789, and the Consolider-Ingenio project CSD2010-00064 (EPI: Exploring the Physics of Inflation). We also acknowledge the support of the Ramón y Cajal fellowship (RyC 2011 148062) awarded by the Spanish MICINN and the Marie Curie Career Integration Grant (CIG 294183).Peer reviewe

    Quality Characteristics and Shelf-Life of Ultra-High Pressure Homogenized (UHPH) Almond Beverage

    Get PDF
    The effects of ultra-high-pressure homogenization (UHPH) at 200 MPa, in combination with different inlet temperatures (55 or 75 °C) during storage at 4 °C were studied and compared with pasteurized (90 °C, 90 s) almond beverage. Microbiological analysis of the physical (particle sedimentation and color) and volatile profile of the most relevant compound in almond beverages was performed at days 1, 7, 14, and 21 of cold storage. UHPH treatment 200 at 75 °C led to higher microbiological reduction after treatment and higher stability during cold storage in almond beverages than pasteurization or UHPH 200 at 55 °C. Physical characteristics of UHPH-treated samples exhibited a high stability during storage with a stable color. Volatile compounds extracted by solid phase microextraction were identified by gas chromatography coupled with mass spectrometry. The effect of UHPH treatment significantly (p < 0.05) affected the volatile profile compared with pasteurized beverages, although UHPH conditions applied produced similar effects in almond beverages. Benzaldehyde was the most abundant compound detected in all treatments. Hexanal was more abundant in UHPH-treated samples, indicating a higher lipid oxidation compared to pasteurized almond beverages

    Artificial intelligence assisted Mid-infrared laser spectroscopy in situ detection of petroleum in soils

    Get PDF
    A simple, remote-sensed method of detection of traces of petroleum in soil combining artificial intelligence (AI) with mid-infrared (MIR) laser spectroscopy is presented. A portable MIR quantum cascade laser (QCL) was used as an excitation source, making the technique amenable to field applications. The MIR spectral region is more informative and useful than the near IR region for the detection of pollutants in soil. Remote sensing, coupled with a support vector machine (SVM) algorithm, was used to accurately identify the presence/absence of traces of petroleum in soil mixtures. Chemometrics tools such as principal component analysis (PCA), partial least square-discriminant analysis (PLS-DA), and SVM demonstrated the e ectiveness of rapidly di erentiating between di erent soil types and detecting the presence of petroleum traces in di erent soil matrices such as sea sand, red soil, and brown soil. Comparisons between results of PLS-DA and SVM were based on sensitivity, selectivity, and areas under receiver-operator curves (ROC). An innovative statistical analysis method of calculating limits of detection (LOD) and limits of decision (LD) from fits of the probability of detection was developed. Results for QCL/PLS-DA models achieved LOD and LD of 0.2% and 0.01% for petroleum/soil, respectively. The superior performance of QCL/SVM models improved these values to 0.04% and 0.003%, respectively, providing better identification probability of soils contaminated with petroleum

    Textural Characterisation on Regions of Interest: A Useful Tool for the Study of Small Vessel Disease

    Get PDF
    Proponemos un marco para investigar las propiedades de los tejidos aparentemente normales en las imágenes de resonancia magnética de la estructura cerebral de pacientes con enfermedad de vasos pequeños (SVD). Implica la extracción de entidades texturales en regiones de interés (ROI) obtenidas a partir de una plantilla anatómicamente relevante, combinada con un análisis estadístico que considere la distribución relativa de marcadores SVD (por ejemplo, microsangrados, espacios perivasculares e hiperintensidades de materia blanca) con respecto a las características texturales de las regiones de interés, en los territorios arteriales derivados de otra plantilla. Aplicamos este enfoque a los datos de 42 pacientes de un estudio de accidente cerebrovascular leve para investigar si los tejidos normales en diferentes regiones cerebrales son homogéneos independientemente de la presencia de marcadores y variedades de SVD específicos en las manifestaciones de la patología (accidente cerebrovascular en diferentes territorios arteriales). Nuestros resultados sugieren que este no es el caso: que los tejidos normales son heterogéneos y que las variaciones locales (representadas por la entropía) están asociadas con marcadores SVD, de acuerdo con los informes clínicos
    corecore