49 research outputs found

    Selecting patterns and features for between- and within-crop-row weed mapping using UAV-imagery

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    This paper approaches the problem of weed mapping for precision agriculture, using imagery provided by Unmanned Aerial Vehicles (UAVs) from sunflower and maize crops. Precision agriculture referred to weed control is mainly based on the design of early post-emergence site-specific control treatments according to weed coverage, where one of the most important challenges is the spectral similarity of crop and weed pixels in early growth stages. Our work tackles this problem in the context of object-based image analysis (OBIA) by means of supervised machine learning methods combined with pattern and feature selection techniques, devising a strategy for alleviating the user intervention in the system while not compromising the accuracy. This work firstly proposes a method for choosing a set of training patterns via clustering techniques so as to consider a representative set of the whole field data spectrum for the classification method. Furthermore, a feature selection method is used to obtain the best discriminating features from a set of several statistics and measures of different nature. Results from this research show that the proposed method for pattern selection is suitable and leads to the construction of robust sets of data. The exploitation of different statistical, spatial and texture metrics represents a new avenue with huge potential for between and within crop-row weed mapping via UAV-imagery and shows good synergy when complemented with OBIA. Finally, there are some measures (specially those linked to vegetation indexes) that are of great influence for weed mapping in both sunflower and maize crops

    Microbiological profile of infections in the Intensive Care Units of Colombia (EPISEPSIS Colombia)

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    Introducción y objetivo En Colombia faltan datos fiables sobre el comportamiento de la sepsis. Se pretende determinar la prevalencia de los microorganismos en las principales infecciones tratadas en las unidades de cuidados intensivos (UCI) de nuestro país. Métodos Este es un subestudio de una cohorte prospectiva recolectada en 10 hospitales durante 6 meses. Los criterios de inclusión eran hospitalización en UCI y confirmación de una infección según las definiciones del CDC, considerando tres grupos (comunidad, hospital, UCI) según el sitio de adquisición de la infección. Resultados Se incluyó en el análisis a 826 pacientes; el 51% contrajeron procesos infecciosos extrahospitalarios; el 5,33%, en el hospital y el 43,7%, en UCI. Los diagnósticos más frecuentes fueron neumonía (29,54%), infección intraabdominal (18,16%) e infección del tracto urinario (11,62%). El microorganismo más frecuente en las infecciones extrahospitalarias fue Escherichia coli —pulmón (16,4%), peritoneo (57,7%), orina (55,5%) y sangre (22,4%)—. En las adquiridas en UCI predomina también E. coli —peritoneo (29,3%) y orina (52,9%)—, excepto en pulmón y sangre, en los que fueron Staphylococcus aureus (32,4%) y Klebsiella pneumoniae (15,7%) los más prevalentes. Se tomaron cultivos a 655 pacientes, de los que el 40% recibió antibióticos antes de la toma, sin que esto afectara al porcentaje de positividad (p=0,583). Conclusiones La neumonía fue la infección más frecuente independientemente del sitio de adquisición. E. coli fue el patógeno más prevalente, excepto en las infecciones pulmonares adquiridas en UCI, donde lo fue S. aureus.Q2Artículo original75-83Background and objective:Valid and reliable data regarding sepsis is lacking in Colombia. Ouraim was to determine the prevalence of the microorganisms in the main infections treated inIntensive Care Units (ICUs) in our country.Methods:This is a sub-study of a prospective cohort with 10 general hospitals in Colombiaduring a 6-month period. The inclusion criteria were hospitalization in ICU and confirmation ofinfection according to the CDC definitions. Patients were classified into three groups, that is,community, hospital and intensive care, according to the site where the infection was acquired.Results:A total of 826 patients were included in this analysis. Of these, 51% developed infec-tions in the community, 5.33% in the hospital and 43.7% in intensive care unit. Overall, themost common diagnoses were pneumonia (29.54%), intra-abdominal infection (18.16%) and uri-nary tract infection (11.62%). The most frequent germ in community-acquired infections wasE. coli—–lung (16. 4%), peritoneum (57.7%), urine (55.5%), blood (22.4%)—–.E. coli—–peritoneum(29.3%), urine (52.9%)—– also predominated in the ICU-acquired infections, except for lung andblood in whichStaphylococcus aureus(32.4%) andKlebsiella pneumoniae(15.7%) were the mostprevalent. Cultures were requested from 655 patients, 40% of them having received antibioticsbefore cultures were taken, although this did not affected the percentages of positive cultures(P= 0.583).Conclusions:Pneumonia was the main cause of infection regardless of the site of acquisition.E. coliwas the most prevalent germ, except in the pulmonary infections acquired in UCI inwhichS. aureuswas the most prevalent

    The QUIJOTE experiment: project status and first scientific results

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    We present the current status of the QUIJOTE (Q-U-I JOint TEnerife) experiment, a new polarimeter with the aim of characterizing the polarization of the Cosmic Microwave Background, and other galactic or extra-galactic physical processes that emit in microwaves in the frequency range 10–42 GHz, and at large angular scales (around 1 degree resolution). The experiment has been designed to reach the required sensitivity to detect a primordial gravitational wave component in the CMB, provided its tensor-to-scalar ratio is larger than r ∼ 0.05. The project consists of two telescopes and three instruments which will survey a large sky area from the Teide Observatory to provide I, Q and U maps of high sensitivity. The first QUIJOTE instrument, known as Multi-Frequency Instrument (MFI), has been surveying the northern sky in four individual frequencies between 10 and 20 GHz since November 2012, providing data with an average sensitivity of 80 µK beam−1 in Q and U in a region of 20, 000 square-degrees. The second instrument, or Thirty-GHz Instrument (TGI), is currently undergoing the commissioning phase, and the third instrument, or Forty-GHz Instrument (FGI), is in the final fabrication phase. Finally, we describe the first scientific results obtained with the MFI. Some specific regions, mainly along the Galactic plane, have been surveyed to a deeper depth, reaching sensitivities of around 40 µK beam−1. We present new upper limits on the polarization of the anomalous dust emission, resulting from these data, in the Perseus molecular complex and in the W43 molecular complex

    Propagation of uncertainty in a rotating pipe mechanism to generate an impinging swirling jet flow for heat transfer from a flat plate

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    In Computational Fluid Dynamics (CFD) studies composed of the coupling of different simulations, the uncertainty in one stage may be propagated to the following stage and affect the accuracy of the prediction. In this paper, a framework for uncertainty quantification in the computational heat transfer by forced convection is applied to the two-step simulation of the mechanical design of a swirling jet flow generated by a rotating pipe (Simulation 1) impinging on a flat plate (Simulation 2). This is the first probabilistic uncertainty analysis on computational heat transfer by impinging jets in the literature. The conclusion drawn from the analysis of this frequent engineering application is that the simulated system does not exhibit a significant sensitivity to stochastic variations of model input parameters, over the tested uncertainty ranges. Additionally, a set of non-linear regression models for the stochastic velocity and turbulent profiles for the pipe nozzle are created and tested, since impinging jets for heat transfer at Reynolds number of Re = 23000 are very frequent in the literature, but stochastic inlet conditions have never been provided. Numerical results demonstrate a negligible difference in the predicted convective heat transfer with respect to the use of the profiles simulated via CFD. These suggested surrogate models can be directly embedded onto other engineering applications (e.g. arrays of jets, jet flows impinging on plates with different shapes, inlet piping in combustion, chemical mixing, etc.) in which a realistic swirling flow under uncertainty can be of interest

    Use of anticoagulants and antiplatelet agents in stable outpatients with coronary artery disease and atrial fibrillation. International CLARIFY registry

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    CIBERER : Spanish national network for research on rare diseases: A highly productive collaborative initiative

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    Altres ajuts: Instituto de Salud Carlos III (ISCIII); Ministerio de Ciencia e Innovación.CIBER (Center for Biomedical Network Research; Centro de Investigación Biomédica En Red) is a public national consortium created in 2006 under the umbrella of the Spanish National Institute of Health Carlos III (ISCIII). This innovative research structure comprises 11 different specific areas dedicated to the main public health priorities in the National Health System. CIBERER, the thematic area of CIBER focused on rare diseases (RDs) currently consists of 75 research groups belonging to universities, research centers, and hospitals of the entire country. CIBERER's mission is to be a center prioritizing and favoring collaboration and cooperation between biomedical and clinical research groups, with special emphasis on the aspects of genetic, molecular, biochemical, and cellular research of RDs. This research is the basis for providing new tools for the diagnosis and therapy of low-prevalence diseases, in line with the International Rare Diseases Research Consortium (IRDiRC) objectives, thus favoring translational research between the scientific environment of the laboratory and the clinical setting of health centers. In this article, we intend to review CIBERER's 15-year journey and summarize the main results obtained in terms of internationalization, scientific production, contributions toward the discovery of new therapies and novel genes associated to diseases, cooperation with patients' associations and many other topics related to RD research

    A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality
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