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Cognitive impairment (CI) is frequently present in multiple sclerosis patients. Despite ongoing research, the neurological substrates have not been fully elucidated. In this study we investigated the contribution of gray and white matter in the CI observed in mildly disabled relapsing-remitting multiple sclerosis (RRMS) patients. For that purpose, 30 patients with RRMS (median EDSS = 2), and 30 age- and sex-matched healthy controls were studied. CI was assessed using the symbol digit modalities test (SDMT) and the memory alteration test. Brain magnetic resonance imaging, diffusion tensor imaging (DTI), voxel-based morphometry (VBM), brain segmentation, thalamic vertex analysis, and connectivity-based thalamic parcellation analyses were performed. RRMS patients scored significantly lower in both cognitive tests. In the patient group, significant atrophy in the thalami was observed. Multiple regression analyses revealed associations between SDMT scores and GM volume in both hemispheres in the temporal, parietal, frontal, and occipital lobes. The DTI results pointed to white matter damage in all thalamocortical connections, the corpus callosum, and several fasciculi. Multiple regression and correlation analyses suggested that in RRMS patients with mild disease, thalamic atrophy and thalamocortical connection damage may lead to slower cognitive processing. Furthermore, white matter damage at specific fasciculi may be related to episodic memory impairment.

This paper presents an acoustic echo canceler based on a U-Net convolutional neural network for single-talk and double-talk scenarios. U-Net networks have previously been used in the audio processing area for source separation problems because of their ability to reproduce the finest details of audio signals, but to our knowledge, this is the first time they have been used for acoustic echo cancellation (AEC). The U-Net hyperparameters have been optimized to obtain the best AEC performance, but using a reduced number of parameters to meet a latency restriction of 40 ms. The training and testing of our model have been carried out within the framework of the 'ICASSP 2021 AEC Challenge' organized by Microsoft. We have trained the optimized U-Net model with a synthetic dataset only (S-U-Net) and with a synthetic dataset and the single-talk set of a real dataset (SR-U-Net), both datasets were released for the challenge. The S-U-Net model presented better results for double-talk scenarios, thus their inferred near-end signals from the blind testset were submitted to the challenge. Our canceler ranked 12th among 17 teams, and 5th among 10 academia teams, obtaining an overall mean opinion score of 3.57., Comment: 6 pages, 2 figures, submitted to the 2021 IEEE International Conference on Acoustics, Speech and Signal Processing on October 2020

Melanoma is an aggressive neoplasm responsible for the majority of deaths from skin cancer. Specifically, spitzoid melanocytic tumors are one of the most challenging melanocytic lesions due to their ambiguous morphological features. The gold standard for its diagnosis and prognosis is the analysis of skin biopsies. In this process, dermatopathologists visualize skin histology slides under a microscope, in a highly time-consuming and subjective task. In the last years, computer-aided diagnosis (CAD) systems have emerged as a promising tool that could support pathologists in daily clinical practice. Nevertheless, no automatic CAD systems have yet been proposed for the analysis of spitzoid lesions. Regarding common melanoma, no system allows both the selection of the tumor region and the prediction of the benign or malignant form in the diagnosis. Motivated by this, we propose a novel end-to-end weakly supervised deep learning model, based on inductive transfer learning with an improved convolutional neural network (CNN) to refine the embedding features of the latent space. The framework is composed of a source model in charge of finding the tumor patch-level patterns, and a target model focuses on the specific diagnosis of a biopsy. The latter retrains the backbone of the source model through a multiple instance learning workflow to obtain the biopsy-level scoring. To evaluate the performance of the proposed methods, we performed extensive experiments on a private skin database with spitzoid lesions. Test results achieved an accuracy of 0.9231 and 0.80 for the source and the target models, respectively. In addition, the heat map findings are directly in line with the clinicians' medical decision and even highlight, in some cases, patterns of interest that were overlooked by the pathologist.

Capsule endoscopy (CE) is a widely used, minimally invasive alternative to traditional endoscopy that allows visualisation of the entire small intestine. Patient preparation can help to obtain a cleaner intestine and thus better visibility in the resulting videos. However, studies on the most effective preparation method are conflicting due to the absence of objective, automatic cleanliness evaluation methods. In this work, we aim to provide such a method capable of presenting results on an intuitive scale, with a relatively light-weight novel convolutional neural network architecture at its core. We trained our model using 5-fold cross-validation on an extensive data set of over 50,000 image patches, collected from 35 different CE procedures, and compared it with state-of-the-art classification methods. From the patch classification results, we developed a method to automatically estimate pixel-level probabilities and deduce cleanliness evaluation scores through automatically learnt thresholds. We then validated our method in a clinical setting on 30 newly collected CE videos, comparing the resulting scores to those independently assigned by human specialists. We obtained the highest classification accuracy for the proposed method (95.23%), with significantly lower average prediction times than for the second-best method. In the validation of our method, we found acceptable agreement with two human specialists compared to interhuman agreement, showing its validity as an objective evaluation method.

To describe novel embryo features capable of predicting implantation potential as input data for an artificial neural network (ANN) model.

Este informe recoge de manera general todo el proceso de la pasantía que tuvo inicio el día 06 de julio de 2016 y finalizó el 06 de diciembre del mismo año. Su intención principal es dar cuenta de todas las actividades que se llevaron a cabo en el marco de los proyectos realizados por la empresa Topografía y Construcciones Mejía S.A.S, en contratación con la empresa constructora IC Prefabricados S.A. En labor conjunta en estas organizaciones se enmarcan los proyectos dentro de los cuales se halla la actividad como pasante de tecnología en topografía de la universidad del Quindío., Pregrado, Tecnólogo en Topografía

The objective of the present work is to evaluate the treatment capacity of the unsaturated zone (UZ) to remove contaminants from a wastewater effluent using a vegetation filter. The wastewater effluent originates from an office building and it is characterized by a high organic carbon and nitrogen load. Prior to its application over the vegetation filter, the raw wastewater is primary treated with an Imhoff tank. The vegetation filter surface is 77 m2 and it has been designed with an intensive plantation density (10,000 plants/ha) to maximize the plants nutrients uptake. The system efficiency has been controlled with a Gee Passive Capillary Lysimeter installed at 90 cm depth that allows a periodical sampling of the infiltrating water through the UZ. Furthermore, the potential groundwater affection derived from the wastewater application was monitored in a downgradient piezometer. The vegetation filter presents a high contaminant removal: up to 85% in terms of concentration in the cases of chemical oxygen demand (COD) and dissolved organic carbon (DOC), 90% for total phosphorus (PT) and 73% for total nitrogen (NT). When the efficiency is evaluated in terms of mass, the values are much higher, reaching 90% of removal for NT. No significant affection was observed in groundwater quality as a consequence of the leaching from the vegetation filter.

The performance of a vegetation filter using a short-rotation coppice of poplars was evaluated over a 3-year period in terms of pollutant removal capacity. The vegetation filter was designed for scattered and small populations with no storage facilities and a wastewater application constrained by the own production of effluent. Wastewater effluent was pre-treated in an Imhoff tank and applied to the vegetation filter. The chemical compositions of drainage water and groundwater were regularly monitored. Surface soil samples at the beginning and the end of the study were also collected. The monitored chemical species in drainage water and groundwater were DOC, COD, NT, NO3–N, NH4–N, PT, PO4-P, and other major ions. Electrical Conductivity, organic matter content (%), NO3–N, available P, cation exchange capacity and major cations were analysed for soil. The vegetation filter presented efficient removal of wastewater-originated pollutants. DOC and COD removal reached values of 85%. A correlated increase in soil organic matter content was detected (from 1.0% to almost 2.8%). A similar removal capacity was observed for PT which is interpreted as due to plant uptake mechanisms and PO43� precipitation in the presence of soil Ca2+. Around 73% of NT was removed. However, due to the high applied NT load, the average NT concentration in drainage water was about 41.9 mg/L, higher than the admissible concentration limit. When considering NT mass, about 10% of the cumulative applied NT leached through the vadose zone. Groundwater quality was not affected by the vegetation filter operation.

The goal of the software proposed in this paper is to assist ophthalmologists in diagnosis and disease prevention, helping them to determine cardiovascular risk or other diseases where the vessels can be altered, as well as to monitor the pathology progression and response to different treatments. The performance of the tool has been evaluated by means of a double-blind study where its sensitivity, specificity, and reproducibility to discriminate between health fundus (without cardiovascular risk) and hypertensive patients has been calculated in contrast to an expert ophthalmologist opinion obtained through a visual inspection of the fundus image. An improvement of almost 20% has been achieved comparing the system results with the clinical visual classification.

The use of treated wastewater with the proper quality for crops irrigation could represent a feasible solution for many arid and semi-arid countries. The current study has been carried out in the Experimental Plant of Carrión de los Céspedes (Sevile, Spain), where two plots of Jatropha curcas L, one irrigated with drinking water and the other one with reclaimed water, has been installed. The main objective of this study was to analyze the major differences between the two plots regarding the soil properties. Soil samples were collected before and after irrigation to control and monitor the evolution of soil properties. Particle size distribution, pH, electrical conductivity, organic matter, available phosphorus and nitrates were measured. After two years of irrigation, a slight decrease in available phosphorus, nitrates and electrical conductivity was observed, in contrast to the organic matter content, which increased. These trends here presented should be contrasted with other soil characteristics.

Recently, it has been shown that conventional wastewater treatment plants (WWTP) cannot completely remove many organic micropollutants. The pharmaceuticals and personal Care Products, PPCPs, are extensively found in water environmental samples. In this group, ibuprofen and triclosan are very representative due to their persistency and ubiquity. Ibuprofen is a non-steroidal anti-inflammatory, analgesic, and antipyretic drug. It is an important non-prescription drug widely used. And triclosan, an antimicrobial chemical, is considered as persistent pollutant in the environment. Industrial chemicals and pesticide are also found in waters. The perfluorooctanoic acid, PFOA, very used in industry because of its chemical and thermal stability, and atrazine, an organochlorine herbicide, is extensively used in agriculture, and is included in lists of priority pollutants. The occurrence of any emerging contaminant, even at low concentrations, can lead to chronic health effects especially at highly contaminated sites, particularly when possible different effects of organic compounds mixtures could take place. Risk assessment of pharmaceuticals in environment needs toxicological information from different trophic levels, especially on non-target organisms. But the studies are usually focused on the evaluation of the effect of a single drug on each organism used. The studies about combined toxicity are very important because the organic pollutants residues found in environmental samples usually occur as mixtures, not as single contaminants and the ecotoxicity values obtained for individual substances do not provide a safe rule for mixtures. Original results of toxicological effects have been obtained for binary, ternary and quaternary mixtures (including ibuprofen) on green algae. The CI-isobologram equation was applied to obtain real toxicity data taking in account the type and level of interactions between pollutants studied. These parameters were used to carry out the risk assessment for aquatic environment due to the occurrence of ibuprofen solely and combined with other contaminants.

Los microcontaminantes orgánicos, ya sean emergentes o prioritarios, se encuentran en multitud de muestras ambientales a causa, fundamentalmente, de la baja eficiencia de las plantas de tratamiento de aguas residuales en su eliminación. Pueden aparecer tanto en las aguas superficiales debido a los vertidos de los efluentes de estas plantas, como en el suelo y en las aguas subterráneas debido al uso de estos efluentes para el riego de cultivos y a las prácticas de abonado con purines o con lodos de depuradora. Consecuentemente, el estudio de la presencia de estos compuestos en el medio ambiente se hace necesario para conocer la presión que ésta supone. Dentro del grupo que engloba estos contaminantes, se ha seleccionado un medicamento de elevado consumo a nivel mundial, el ibuprofeno, el cual no aparece como un contaminante individual en el medio, sino que se encuentra combinado con otros compuestos. Partiendo de esta hipótesis, en esta Tesis Doctoral se ha planteado, en primer lugar, estimar la movilidad del ibuprofeno en el suelo para determinar su disponibilidad en distintos medios naturales y determinar los comportamientos sinérgicos del compuesto en suelo y agua cuando aparece mezclado con otros contaminantes orgánicos, para finalmente cuantificar el riesgo ambiental asociado a este contaminante emergente en medio terrestre y acuático. La movilidad del ibuprofeno se estudió mediante ensayos de adsorción y desorción, definiendo así una fijación moderada para el compuesto en el suelo y una adsorción reversible, lo cual demuestra que puede encontrarse disponible tanto en el propio suelo como en las masas de agua que pueda alcanzar por lixiviación. La toxicidad en agua, analizada para las mezclas de ibuprofeno con PFOA (ácido perfluorooctanoico), atrazina y triclosán sobre la microalga verde Pseudokirchneriella subcapitata, mostró tendencias al sinergismo cuando el medicamento se hallaba presente. En el caso del suelo, la toxicidad fue determinada para el ibuprofeno y el PFOA, actuando de manera individual y en su combinación binaria, sobre la planta superior Sorghum bicolor. Se estudiaron los efectos sobre la elongación de las raíces en los primeros días de crecimiento y sobre la emisión de fluorescencia de la clorofila a. El perfil toxicológico predominante fue también la sinergia. Una vez definida la toxicidad para las distintas combinaciones de contaminantes trabajadas y sobre el organismo acuático y el organismo terrestre, se cuantificaron los riesgos ambientales mediante el cálculo de los cocientes de riesgo (HQ, Hazard Quotient). Las concentraciones toxicológicas a utilizar se obtuvieron mediante tres métodos: Adición de Concentración, Acción Independiente y el Índice de Combinación. Tras analizar los resultados se pudo concluir que el ibuprofeno es un compuesto móvil en el suelo, por lo que es necesario estudiar su toxicología en medios acuáticos y terrestres; que en ambos medios se presentan sinergias cuando este medicamento se encuentra combinado con otros contaminantes emergentes y prioritarios y que por tanto, el uso de un modelo capaz de tener en cuenta en el cálculo de las toxicidades estas sinergias, como es el Índice de Combinación aquí empleado, es necesario para obtener de manera precisa la información toxicológica de estas mezclas. Y finalmente, que el análisis de los procesos fotosintéticos de una planta superior, como la fluorescencia de la clorofila a, es una herramienta fácil, económica y eficaz para el cálculo de riesgos ambientales en el suelo. The organic micropollutants, emerging or priority, have been found in a lot of environmental samples, mainly due to they are not completely removed in the wastewater treatment plants. They appear in surface waters because of the discharges of effluents from these plants, and in soils and groundwater due to the use of reclaimed water in crop irrigation or due to the application of sewage sludge and manures like fertilizers on agricultural soils. Consequently, is necessary to know the environmental contamination which their presence supposes. In the group of these pollutants, ibuprofen, a pharmaceutical with high worldwide consumption, has been selected. It does not only appear alone in the environment, but also appear combined with other compounds. From this hypothesis, in this Thesis has been proposed, first, estimate the ibuprofen mobility in the soil to determine its availability in different natural media, determinate the synergic behaviors which take place in soil and water when ibuprofen is mixed with other organic compounds, and finally to quantify the environmental risk of this emerging pollutant in aquatic and terrestrial environments. The mobility of the ibuprofen was studied by carrying out adsorption and desorption experiments, which showed a moderate fixation in soil and a reversible adsorption, demonstrating its availability in the soil and in the groundwater by lixiviation. The water toxicity, analyzed for mixes of ibuprofen, PFOA (perfluorooctanoic acid), atrazine and triclosan on the green microalgae Pseudokirchneriella subcapitata, showed synergistic trends when the compound was present in the studied combinations. In the soil, the toxicity was determined for ibuprofen and PFOA, individually and combined between them, on the high plant Sorghum bicolor. The root elongation and the emission of the chlorophyll a fluorescence were studied. The main toxicological profile was the synergy. When all the toxicities were defined on both organisms, the environmental risks were quantified by calculating the Hazard Quotients, HQ. The toxicological concentrations were calculated by applying three different methods: Concentration Addition, Independent Action and the Combination Index. We concluded that the ibuprofen is a mobile compound in soils, so the toxicity in aquatic and terrestrial environments should be studied; in both environments the synergistic behavior occurs when ibuprofen is combined with emerging or priority pollutants, and, therefore, the application of a model which takes into account the synergic behavior in the toxicity calculation, as the Combination Index used in this work, is necessary. And finally, that the photosynthetic processes analysis in a high plant, as the chlorophyll a fluorescence, is an easy, economic and efficient tool to assess the environmental risk in soils.

Investigadores del Programa Consolider Tragua “Tratamiento y Reutilización de Aguas Residuales para una Gestión Sostenible” han llevado a cabo un estudio sobre la viabilidad de cultivar en España Jatropha curcas L., cultivo no alimentario destinado a la producción de biodiésel, utilizando aguas regeneradas para su riego. Sus resultados y conclusiones se resumen a continuación. Researchers working on the Programa Consolider Tragua “Treatment and Reuse of Waste Water for Sustainable Management” have carried out a study on the feasibility of cultivating in Spain the non-edible crop for the production of biodiesel, Jatropha curcas L., using reclaimed water for its irrigation. The findings and conclusions of this study are described below.

International audience; The GRAVITY instrument is a beam-combining interferometer for the four telescopes of the VLT, and relies upon four near-infrared (1.4-2.4 micron) Shack-Hartmann style wave-front sensors to determine the atmospheric distortion due to atmospheric turbulence. The GRAVITY AO system will then drive the VLT's MACAO deformable mirrors to correct the wavefront, permiting 10 micro-arcsecond astrometry. We present the current design and status of the wave front sensor system, as well as future plans for integration and test.

We used the near-IR imager/spectrograph LUCIFER mounted on the Large Binocular Telescope (LBT) to image, with sub-arcsec seeing, the local dwarf starburst NGC 1569 in the JHK bands and HeI 1.08 micron, [FeII] 1.64 micron and Brgamma narrow-band filters. We obtained high-quality spatial maps of HeI, [FeII] and Brgamma emission across the galaxy, and used them together with HST/ACS images of NGC 1569 in the Halpha filter to derive the two-dimensional spatial map of the dust extinction and surface star formation rate density. We show that dust extinction is rather patchy and, on average, higher in the North-West (NW) portion of the galaxy [E_g(B-V) = 0.71 mag] than in the South-East [E_g(B-V) = 0.57 mag]. Similarly, the surface density of star formation rate peaks in the NW region of NGC 1569, reaching a value of about 4 x 10^-6 M_sun yr^-1 pc^-2. The total star formation rate as estimated from the integrated, dereddened Halpha luminosity is about 0.4 M_sun yr^-1, and the total supernova rate from the integrated, dereddened [FeII] luminosity is about 0.005 yr^-1 (assuming a distance of 3.36 Mpc). The azimuthally averaged [FeII]/Brgamma flux ratio is larger at the edges of the central, gas-deficient cavities (encompassing the super star clusters A and B) and in the galaxy outskirts. If we interpret this line ratio as the ratio between the average past star formation (as traced by supernovae) and on-going activity (represented by OB stars able to ionize the interstellar medium), it would then indicate that star formation has been quenched within the central cavities and lately triggered in a ring around them. The number of ionizing hydrogen and helium photons as computed from the integrated, dereddened Halpha and HeI luminosities suggests that the latest burst of star formation occurred about 4 Myr ago and produced new stars with a total mass of ~1.8 x 10^6 M_sun. [Abridged], Comment: accepted for publication in AJ

The lone star tick, Amblyomma americanum, vectors pathogens of emerging diseases of humans and animals in the United States. Currently, measures are not available for effective control of A. americanum infestations. Development of vaccines directed against tick proteins may reduce tick infestations and the transmission of tick-borne pathogens. However, the limiting step in tick vaccine development has been the identification of tick protective antigens. Herein, we report the application of RNA interference (RNAi) for screening an A. americanum cDNA library for discovery of tick protective antigens that reduce tick survival and weights after feeding. Four cDNA clones, encoding for putative threonyl-tRNA synthetase (2C9), 60S ribosomal proteins L13a (2D10) and L13e (2B7), and interphase cytoplasm foci protein 45 (2G7), were selected for vaccine studies in cattle, along with subolesin, a tick protective protein identified previously. In vaccinated cattle, an overall efficacy (E) > 30% was obtained when considering the vaccine effect on both nymphs and adults, but only 2D10, 2G7 and subolesin affected both tick stages. The highest efficacy of control for adult ticks (E > 55%) was obtained in cattle vaccinated with recombinant 2G7 or subolesin. These collective results demonstrated the feasibility of developing vaccines for the control of lone star tick infestations. The use of RNAi for identification of tick protective antigens proved to be a rapid and cost-effective tool for discovery of candidate vaccine antigens, and this approach could likely be applied to other parasites of veterinary and medical importance., This research was supported by grants from NRI-USDA (project No. 2007-04613); INIA, Spain (project FAU2008-00014-00-00); the Consejería de Educación y Ciencia, JCCM, Spain (project PEII09-0118-8907); the Oklahoma Agricultural Experiment Station (project 1669) and the Walter R. Sitlington Endowed Chair for Food Animal Research (K. M. Kocan, Oklahoma State University). Raúl Manzano-Roman was funded by Ministerio de Educación y Ciencia, Spain. V. Naranjo was founded by the European Social Fund and the Junta de Comunidades de Castilla-La Mancha (Program FSE 2007-2013), Spain. M. Canales was funded by the Wellcome Trust under the “Animal Health in the Developing World” initiative (project 0757990). R.C. Galindo was funded by Ministerio de Educación y Ciencia, Spain. M. Villar was funded by the JAE-DOC program (CSIC-FSE), Spain.

The lone star tick, Amblyomma americanum, vectors pathogens of emerging diseases of humans and animals in the United States. Currently, measures are not available for effective control of A. americanum infestations. Development of vaccines directed against tick proteins may reduce tick infestations and the transmission of tick-borne pathogens. However, the limiting step in tick vaccine development has been the identification of tick protective antigens. Herein, we report the application of RNA interference (RNAi) for screening an A. americanum cDNA library for discovery of tick protective antigens that reduce tick survival and weights after feeding. Four cDNA clones, encoding for putative threonyl-tRNA synthetase (2C9), 60S ribosomal proteins L13a (2D10) and L13e (2B7), and interphase cytoplasm foci protein 45 (2G7), were selected for vaccine studies in cattle, along with subolesin, a tick protective protein identified previously. In vaccinated cattle, an overall efficacy (E) > 30% was obtained when considering the vaccine effect on both nymphs and adults, but only 2D10, 2G7 and subolesin affected both tick stages. The highest efficacy of control for adult ticks (E > 55%) was obtained in cattle vaccinated with recombinant 2G7 or subolesin. These collective results demonstrated the feasibility of developing vaccines for the control of lone star tick infestations. The use of RNAi for identification of tick protective antigens proved to be a rapid and cost-effective tool for discovery of candidate vaccine antigens, and this approach could likely be applied to other parasites of veterinary and medical importance.

CARMENES, Calar Alto high-Resolution search for M dwarfs with Exo-earths with a Near-infrared Echelle Spectrograph, is a study for a next-generation instrument for the 3.5m Calar Alto Telescope to be designed, built, integrated, and operated by a consortium of nine German and Spanish institutions. Our main objective is finding habitable exoplanets around M dwarfs, which will be achieved by radial velocity measurements on the m/s level in the near-infrared, where low-mass stars emit the bulk of their radiation., Comment: Astronomical Society of the Pacific Conference Series, "Pathways towards habitable planets", eds. V. Coude du Foresto, D. M. Gelino & I. Ribas, 14-18 Sep 2009, Barcelona, Spain (in press) Note: Because of space restriction, the printed conference paper will appear with only an abbreviated author list

Articulo en el que se menciona la vida y obra de Monseñor Rafael María Carrasquilla. También se destaca la labor de Monseñor como profesor de metafísica y filosofía.

Don Heliodoro Ramírez A.

Centro Jurídico

Publication in the conference proceedings of EUSIPCO, Lausanne, Switzerland, 2008

GRAVITY is the second generation Very Large Telescope Interferometer instrument for precision narrow-angle astrometry and interferometric imaging. With its fibre-fed integrated optics, wavefront sensors, fringe tracker, beam stabilisation and a novel metrology concept, GRAVITY will push the sensitivity and accuracy of astrometry and interferometric imaging far beyond what is offered today. Providing precision astrometry of order 10 microarcseconds, and imaging with 4-milliarcsecond resolution, GRAVITY will revolutionise dynamical measurements of celestial objects: it will probe physics close to the event horizon of the Galactic Centre black hole; unambiguously detect and measure the masses of black holes in massive star clusters throughout the Milky Way; uncover the details of mass accretion and jets in young stellar objects and active galactic nuclei; and probe the motion of binary stars, exoplanets and young stellar discs. The instrument capabilities of GRAVITY are outlined and the science opportunities that will open up are summarised.

International audience; This paper describes a new approach to determine vas-cular skeleton in retinal images. This approach is based on mathematical morphology along with curvature evaluation. In particular, a variant of the watershed transformation, the stochastic watershed, is applied to extract the vessel center-line. Its goal is to obtain directly the skeleton of the retinal tree avoiding a previous stage of vessel segmentation in order to reduce the dependence between stages and the computational cost. Experimental results show qualitative improvements if the proposed method is compared with other state-of-the-art algorithms, above all on pathological images. Therefore , the result of this work is an efficient and effective vessel centerline extraction algorithm and can be useful for further applications and image-aided diagnosis systems.

Context. The ESPRI project relies on the astrometric capabilities offered by the PRIMA facility of the Very Large Telescope Interferometer for discovering and studying planetary systems. Our survey consists of obtaining high-precision astrometry for a large sample of stars over several years to detect their barycentric motions due to orbiting planets. We present the operation's principle, the instrument's implementation, and the results of a first series of test observations. Aims. We give a comprehensive overview of the instrument infrastructure and present the observation strategy for dual-field relative astrometry in the infrared K-band. We describe the differential delay lines, a key component of the PRIMA facility that was delivered by the ESPRI consortium, and discuss their performance within the facility. This paper serves as reference for future ESPRI publications and for the users of the PRIMA facility. Methods. Observations of bright visual binaries were used to test the observation procedures and to establish the instrument's astrometric precision and accuracy. The data reduction strategy for the astrometry and the necessary corrections to the raw data are presented. Adaptive optics observations with NACO were used as an independent verification of PRIMA astrometric observations. Results. The PRIMA facility was used to carry out tests of astrometric observations. The astrometric performance in terms of precision is limited by the atmospheric turbulence at a level close to the theoretical expectations and a precision of 30 mu as was achieved. In contrast, the astrometric accuracy is insufficient for the goals of the ESPRI project and is currently limited by systematic errors that originate in the part of the interferometer beamtrain that is not monitored by the internal metrology system. Conclusions. Our observations led to defining corrective actions required to make the facility ready for carrying out the ESPRI search for extrasolar planets.

Surveys have shown that super-Earth and Neptune-mass exoplanets are more frequent than gas giants around low-mass stars, as predicted by the core accretion theory of planet formation. We report the discovery of a giant planet around the very-low-mass star GJ 3512, as determined by optical and near-infrared radial-velocity observations. The planet has a minimum mass of 0.46 Jupiter masses, very high for such a small host star, and an eccentric 204-day orbit. Dynamical models show that the high eccentricity is most likely due to planet-planet interactions. We use simulations to demonstrate that the GJ 3512 planetary system challenges generally accepted formation theories, and that it puts constraints on the planet accretion and migration rates. Disk instabilities may be more efficient in forming planets than previously thought.Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science, This research was supported by the following programs, grants, and fellowships: Spanish Ministry for Science, Innovation and Universities (MCIU) ESP2014-54062-R, ESP2014-54362P, AYA2015-69350-C3-2-P, BES-2015-074542, AYA2016-79425-C3-1/2/3-P, ESP2016-76076-R, ESP2016-80435-C2-1-R, ESP2016-80435-C2-2-R, ESP2017-87143-R, ESP2017-87676-C05-02-R, ESP-2017-87676-2-2, RYC-2012-09913 (>Ramon y Cajal> program), and FPU15/01476; Israel Science Foundation grant 848/16, CONICYT-FONDECYT/Chile Postdoctorado 3180405; Deutsches Zentrum fur Luft-un Raumfahrt (DLR) 50OW0204 and 50OO1501; Italian Minister of Instruction, University and Research (MIUR), FFABR 2017; University of Rome Tor Vergata, >Mission: Sustainability 2016> fund; European Research Council under the European Union Horizon 2020 research and innovation program 694513; Mexican national council for science and technology CONACYT, CVU 448248; the >Center of Excellence Severo Ochoa> award for the Instituto de Astrofisica de Andalucia (SEV-2017-0709); Generalitat de Catalunya/CERCA program; Fondo Europeo de Desarollo Regional (FEDER); German Science Foundation (DFG) Research Unit FOR2544 >Blue Planets around Red Stars> and Priority Programs SPP 1833, >Building a Habitable Earth> and SPP 1992, >Exploring the Diversity of Extrasolar Planets> NSF grants PHY17-48958 and PHY-1607761; Swiss National Science Foundation under grant BSGIO_155816 >PlaneltsInTime' and within the framework of the NCCR PlanetS; Queen Mary University of London Scholarship and STFC Consolidated Grant ST/P000592/1; Spanish MCIU FPI-SO predoctoral contract BES-2017-082610 and the Knut and Alice Wallenberg Foundation.