4,953 research outputs found

    On-line identification of seeds in mandarins with magnetic resonance imaging

    Get PDF
    Mandarins have been inspected using magnetic resonance imaging (MRI) in order to detect the presence of seeds. To enhance contrast between seeds and pulp, effective transverse relaxation time-weighted fast low angle shot images (703 ms acquisition time) were acquired. Stationary fruits were imaged and then the images were segmented to extract several features. The maximum radius of the region containing the seeds and the central axis rmax, and the perimeter of this region P were the most powerful features for discrimination between seedless and seed-containing fruits. Such features were the most robust since they showed the lowest noise-to-signal ratios (N/S). The proportions of correct classification were 88.9% and 86.7% for seedless and seed-containing fruits, respectively, under MRI stationary conditions. The performance under on-line conditions was evaluated by imaging the fruits while conveyed at 54 mm/s. An analysis of variance with the features extracted from the static images and the motion-corrected dynamic images showed that there were statistically indistinguishable. The proportions of correct classification were 92.5% and 79.5% for the seedless and seed-containing category, respectively, under MRI dynamic conditions. Reduction in the distance between categories for rmax was addressed as the main cause for the decrease in discrimination performance. The robustness of the motion correction procedure was highlighted by the low differences in the N/S ratio and the noise-to-measured range ratios between static and dynamic features

    An NMR study on internal browning in pears

    Get PDF
    Internal browning in pears (Pyrus communis L. cv. Blanquilla) has been studied by NMR and MRI in order to develop a non-destructive procedure for on-line disorder identification. For NMR relaxometry, disordered tissue shows higher transverse relaxation rates compared to sound tissue, especially at higher magnetic field strength and for long pulse spacing. Membrane alteration and therefore tissue disintegration, as well as water evaporation, appear to be the main causes of this response. Correlation between relaxation times and diffusion showed that the proton pools in disordered tissue are grouped into a smaller number of populations compared to sound tissue, also highlighting cell decompartmentation in disordered tissue. At a macroscopic level, fast low angle shot MR images, effective transverse relaxation-weighted (TR 11 ms and TE 3.7 ms) and proton density-weighted (TR 7.6 ms and TE 2.5 ms), were acquired for pears at a rate of 54 mm/s. Images have been discriminated for internal breakdown according to histogram characteristics. Up to 94 and 96% of pears, respectively, were correctly classified in the former and the latter type of images. In this study a minimum value of 12% of tissue affected by breakdown was always clearly identifie

    Chemical abundances of stars with brown-dwarf companions

    Full text link
    It is well-known that stars with giant planets are on average more metal-rich than stars without giant planets, whereas stars with detected low-mass planets do not need to be metal-rich. With the aim of studying the weak boundary that separates giant planets and brown dwarfs (BDs) and their formation mechanism, we analyze the spectra of a sample of stars with already confirmed BD companions both by radial velocity and astrometry. We employ standard and automatic tools to perform an EW-based analysis and to derive chemical abundances from CORALIE spectra of stars with BD companions. We compare these abundances with those of stars without detected planets and with low-mass and giant-mass planets. We find that stars with BDs do not have metallicities and chemical abundances similar to those of giant-planet hosts but they resemble the composition of stars with low-mass planets. The distribution of mean abundances of α\alpha-elements and iron peak elements of stars with BDs exhibit a peak at about solar abundance whereas for stars with low-mass and high-mass planets the [Xα_\alpha/H] and [XFe_{\rm Fe}/H] peak abundances remain at 0.1\sim -0.1~dex and +0.15\sim +0.15~dex, respectively. We display these element abundances for stars with low-mass and high-mass planets, and BDs versus the minimum mass, mCsinim_C \sin i, of the most-massive substellar companion in each system, and we find a maximum in α\alpha-element as well as Fe-peak abundances at mCsini1.35±0.20m_C \sin i \sim 1.35\pm 0.20 jupiter masses. We discuss the implication of these results in the context of the formation scenario of BDs in comparison with that of giant planets.Comment: Accepted for publication in Astronomy & Astrophysic

    Remodelación, Transformación y Rehabilitación. Tres formas de intervenir en la Vivienda Social del siglo XX

    Get PDF
    Social housing built in Spain between 1939 and 1976 constitutes a widespread urban pattern in contemporary cities. Its initial conditions, along with the effects of time, have led to obsolescence, requiring refurbishment for revitalisation. Programs developed over the last few years not only have provided the buildings with the appropriate standards of living conditions, but also have articulated them as a whole, integrating them into the socio-economic configuration of their urban area. The evolution of these intervention models will be reviewed analyzing the Urban Remodeling of Orcasitas (Madrid) and Viviendas del Gobernador housing (Barcelona), the Urban Transformation of La Mina (Barcelona) and the Integral Renovation of Barrio de Lourdes (Tudela).La vivienda social construida en España entre 1939 y 1976 supone un patrón urbano extendido en la ciudad contemporánea. Sus condiciones de partida y el efecto del tiempo la han llevado a desarrollar una serie de obsolescencias, que hacen necesario intervenir para conseguir su revitalización. Los programas desarrollados en los últimos años se ocupan de dotar a las edificaciones de unos niveles de habitabilidad adecuados, pero también de su articulación como grupo, y de su integración en la distribución socioeconómica del núcleo urbano. Mediante el análisis de la Remodelación Urbana de Orcasitas (Madrid) y de las Viviendas del Gobernador (Barcelona), la Transformación Urbana de La Mina (Barcelona) y la Rehabilitación Integral del Barrio de Lourdes (Tudela) se estudiará la evolución de estos modelos de actuación

    Espectros NIR y longitudes de onda específicas para la estimación del contenido de aceite y agua en aceitunas

    Get PDF
    Knowledge about the oil and water contents in olive fruits is required to determine orchard management, harvest time, and the oil extraction process. The simplification of procedures and of equipment based on NIR Spectroscopy is of major interest. Estimation models for oil and water contents on a fresh matter basis were developed by partial least square regression with NIR spectral data (700 wavelengths). For raw absorbance data the r2 for the test set reached 0.9 and 0.92 for oil and water contents; and RPIQt was 4.9 and 4.3, respectively. The identification of a useful relation of the relative absorbance at 1724 nm and 1760 nm to the oil content allowed for restricting the wavelengths to three. For oil content the r2 showed 0.88 with ad RPIQt of 4.4. For water content the r2 value was 0.84 and the RPIQt was 3.1. Estimation performance with only three wavelengths was comparable to that obtained with PLSR with 700 variables.El contenido de aceite y agua en aceitunas es requerido para gestionar el manejo del cultivo, el momento de cosecha y el proceso de extracción de aceite. La simplificación de los procedimientos y de los equipos basados en espectroscopia NIR es de gran interés. Se desarrollaron modelos de estimación para el contenido de aceite y agua sobre peso fresco por regresión de mínimos cuadrados parciales con datos espectrales NIR (700 longitudes de onda). Para los datos de absorbancia crudos, el r2 para el conjunto de validación externa alcanzó 0.9 y 0.92 para el contenido de aceite y agua; y RPIQt fue 4,9 y 4,3 respectivamente. La identificación de una relación útil de la absorbancia relativa a 1724 nm y 1760 nm con el contenido de aceite, permitió restringir las longitudes de onda a tres. Para el contenido de aceite, el r2 alcanzó 0,88 y RPIQt fue 4,4. Para el contenido de agua, el valor de r2 fue de 0,84 y el RPIQt fue de 3,1. La calidad de la estimación con solo tres longitudes de onda fue comparable al obtenido con PLSR en 700 variables

    Predictores del estado post-ictus en el alta hospitalaria. Importancia en enfermería

    Get PDF
    Nurses are often asked to predict factors that influence post-stroke outcome by the patient and family. Many studies have been carried out in order to determine the factors that influence the neurological status of the post-stroke patient at the moment of the discharge from the hospital. However, machine learning techniques have not been used for this purpose. Therefore, with the objective of obtaining association rules of neurological prognosis, a double analysis, both clinical and with machine learning techniques of the possible associations of factors that influence the neurological status of the post-stroke patients has been carried out. The Apriori algorithm detected several association rules with high confidence (≥ 95%), from which the following pattern: In patients in the age range of 50-80 years, the association of a NIHSS between 11 and 15 points (intermediate/low NIHSS), along with thrombectomy, leads to recovery ad integrum at discharge. With the SMOTE resampling technique, the 100% confidence was reached for the association of high NIHSS (>20) and involvement of the carotid and basilar arteries, with a dire prognosis (exitus). These rules confirm, for the first time with machine learning, the importance of the association of some predictors, in the post-stroke prognosis. The knowledge by the nurses of these association rules can successfully improve stroke outcome. In addition, the role of nurses in education programs that teach knowledge of risk factors and stroke prognosis becomes essential.A menudo, por parte del paciente y de la familia, se solicita a los profesionales de enfermería que predigan los factores que influyen en el estado post-ictus. Se han realizado numerosos estudios para determinar los factores que influyen en el estado neurológico post-ictus en el momento del alta hospitalaria. Sin embargo, las técnicas de aprendizaje automático no se han utilizado para este propósito. Con el objetivo de obtener reglas de asociación del pronóstico neurológico, se ha llevado a cabo un doble análisis, tanto clínico como con técnicas de aprendizaje automático, de las posibles asociaciones de factores que influyen en el estado neurológico de los pacientes post-ictus. El algoritmo Apriori detectó varias reglas de asociación con alta confianza (≥ 95%), con el siguiente patrón: En pacientes en el rango de edad de 50-80 años, la asociación de un NIHSS entre 11 y 15 puntos (NIHSS intermedio/bajo), junto con la trombectomía, conduce a la recuperación ad integrum al alta. Con la técnica de remuestreo SMOTE, se alcanzó el 100% de confianza para la asociación de NIHSS elevado (>20) y afectación de las arterias carótida y basilar, con pronóstico nefasto (exitus). Estas reglas confirman, por primera vez con aprendizaje automático, la importancia de la asociación de algunos predictores, en el pronóstico post-ictus. El conocimiento por parte de las enfermeras de estas reglas puede mejorar los resultados del ictus. Adicionalmente, el papel de la enfermería en los programas de educación sobre los factores de riesgo, y pronóstico de un ictus se torna imprescindible

    Cap on van els Programes de Garantia Social? Estudi i anàlisi de la implantació.

    Get PDF
    La inquietud creada en amplis sectors del professorat per la implantació de la LOGSE ha tingut un ressò singular en els Programes de Garantia Social (PGS), especialment pel que fa als mecanismes legals i psicopedagògics, que haurien de permetre articular els diferents components que constitueixen I'entramat de la seva estructura i de les seves modalitats

    Spatiotemporal changes in aerosol properties by hygroscopic growth and impacts on radiative forcing and heating rates during DISCOVER-AQ 2011

    Get PDF
    This research has been supported by the H2020 Marie Sklodowska-Curie Actions (grant no. 778349), the Spanish Ministry of Economy and Competitiveness (RTI2018101154.A.I00), and by the Russian Science Foundation (project 2117-00114, entitled Development of lidar retrieval algorithms).This work focuses on the characterization of vertically resolved aerosol hygroscopicity properties and their direct radiative effects through a unique combination of ground-based and airborne remote sensing measurements during the Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) 2011 field campaign in the Baltimore-Washington DC metropolitan area. To that end, we combined aerosol measurements from a multiwavelength Raman lidar located at NASA Goddard Space Flight Center and the airborne NASA Langley High Spectral Resolution Lidar-1 (HSRL-1) lidar system. In situ measurements aboard the P-3B airplane and ground-based Aerosol Robotic Network - Distributed Regional Aerosol Gridded Observational Network (AERONET-DRAGON) served to validate and complement quantifications of aerosol hygroscopicity from lidar measurements and also to extend the study both temporally and spatially. The focus here is on 22 and 29 July 2011, which were very humid days and characterized by a stable atmosphere and increasing relative humidity with height in the planetary boundary layer (PBL). Combined lidar and radiosonde (temperature and water vapor mixing ratio) measurements allowed the retrieval of the Hanel hygroscopic growth factor which agreed with that obtained from airborne in situ measurements and also explained the significant increase of extinction and backscattering with height. Airborne measurements also confirmed aerosol hygroscopicity throughout the entire day in the PBL and identified sulfates and water-soluble organic carbon as the main species of aerosol particles. The combined Raman and HSRL-1 measurements permitted the inversion for aerosol microphysical properties revealing an increase of particle radius with altitude consistent with hygroscopic growth. Aerosol hygroscopicity pattern served as a possible explanation of aerosol optical depth increases during the day, particularly for fine-mode particles. Lidar measurements were used as input to the libRadtran radiative transfer code to obtain vertically resolved aerosol radiative effects and heating rates under dry and humid conditions, and the results reveal that aerosol hygroscopicity is responsible for larger cooling effects in the shortwave range (7-10 W m(-2) depending on aerosol load) near the ground, while heating rates produced a warming of 0.12 K d(-1) near the top of PBL where aerosol hygroscopic growth was highest.H2020 Marie Sklodowska-Curie Actions 778349Spanish Ministry of Economy and Competitiveness RTI2018101154.A.I00Russian Science Foundation (RSF) 2117-0011

    Loxosceles rufescens bite on the finger of one hand: a case report

    Get PDF
    Las picaduras por artrópodos son frecuentes en nuestro medio. El veneno de la araña Loxosceles rufescens tiene propiedades necrotizantes, hemolíticas, vasculíticas y coagulantes, y el cuadro puede presentarse como loxoscelismo cutáneo o loxoscelismo sistémico, menos frecuente. En la piel provoca dolor, eritema y edema localizados, seguido por el desarrollo de la necrosis, esto es debido a alteraciones vasculares, con áreas de vasoconstricción y otras de hemorragias que conllevan a isquemia local y a veces a la placa gangrenosa. Presentamos el caso de una paciente de 40 años que sufrió una mordedura de araña en el segundo dedo de la mano derecha, donde desarrolló una lesión necrótica con afectación articular, y que acabó con tratamiento quirúrgico debido a una evolución tórpida.Arthropod stings are frequent in our environment. The venom of the spider Loxosceles rufescens has necrotizing, hemolytic, vasculitic and coagulating properties, and the picture can be presented as cutaneous loxoscelism or systemic loxoscelism, less frequent. In the skin it causes pain, erythema and localized edema, followed by the development of necrosis, this is due to vascular alterations, with areas of vasoconstriction and other hemorrhages that lead to local ischemia and sometimes gangrenous plaque. We present the case of a 40-year-old patient who suffered a spider bite on the second finger of the right hand, where she developed a necrotic lesion with joint involvement, and which ended with surgical treatment due to the torpid evolution
    corecore