347 research outputs found

    Extending General Compact Querieable Representations to GIS Applications

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    The raster model is commonly used for the representation of images in many domains, and is especially useful in Geographic Information Systems (GIS) to store information about continuous variables of the space (elevation, temperature, etc.). Current representations of raster data are usually designed for external memory or, when stored in main memory, lack efficient query capabilities. In this paper we propose compact representations to efficiently store and query raster datasets in main memory. We present different representations for binary raster data, general raster data and time-evolving raster data. We experimentally compare our proposals with traditional storage mechanisms such as linear quadtrees or compressed GeoTIFF files. Results show that our structures are up to 10 times smaller than classical linear quadtrees, and even comparable in space to non-querieable representations of raster data, while efficiently answering a number of typical queries.Comment: This research has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Actions H2020-MSCA-RISE-2015 BIRDS GA No. 690941

    Tendencia de las hospitalizaciones, reingresos y mortalidad intrahospitalaria en los pacientes infectados por VIH entre 1993-2013: impacto de la coinfección por el virus de la hepatitis C

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    [Abstract] Background. New patterns in epidemiological characteristics of people living with HIV infection (PLWH) and the introduction of Highly Active Antiretroviral Therapy (HAART) have changed the profile of hospital admissions in this population. The aim of this study was to evaluate trends in hospital admissions, re-admissions, and mortality rates in HIV patients and to analyze the role of HCV co-infection. Methods. A retrospective cohort study conducted on all hospital admissions of HIV patients between 1993 and 2013. The study time was divided in two periods (1993–2002 and 2003–2013) to be compared by conducting a comparative cross-sectional analysis. Results. A total of 22,901 patient-years were included in the analysis, with 6917 hospital admissions, corresponding to 1937 subjects (75% male, mean age 36 ± 11 years, 37% HIV/HCV co-infected patients). The median length of hospital stay was 8 days (5–16), and the 30-day hospital re-admission rate was 20.1%. A significant decrease in hospital admissions related with infectious and psychiatric diseases was observed in the last period (2003–2013), but there was an increase in those related with malignancies, cardiovascular, gastrointestinal, and chronic respiratory diseases. In-hospital mortality remained high (6.8% in the first period vs. 6.3% in the second one), with a progressive increase of non-AIDS-defining illness deaths (37.9% vs. 68.3%, P < .001). The admission rate significantly dropped after 1996 (4.9% yearly), but it was less pronounced in HCV co-infected patients (1.7% yearly). Conclusions. Hospital admissions due to infectious and psychiatric disorders have decreased, with a significant increase in non-AIDS-defining malignancies, cardiovascular, and chronic respiratory diseases. In-hospital mortality is currently still high, but mainly because of non-AIDS-defining illnesses. HCV co-infection increased the hospital stay and re-admissions during the study period.[Resumen] Introducción. Los cambios en las características epidemiológicas de los pacientes con infección por el VIH, y la introducción del tratamiento antirretroviral de alta eficacia, han modificado el perfil de las hospitalizaciones en esta población. El objetivo del estudio fue evaluar las tendencias en hospitalización, reingreso y mortalidad en pacientes VIH, y analizar el papel de la coinfección por el VHC. Métodos. Estudio de cohortes retrospectivo, que incluyó todas las hospitalizaciones de pacientes VIH entre 1993-2013. El estudio fue dividido en 2 periodos (1993-2002 y 2003-2013) para ser comparados mediante un análisis transversal. Resultados. Se analizaron 22.901 pacientes/años, que presentaron 6.917 hospitalizaciones que correspondieron a 1.937 pacientes (75% varones, edad media 36 ± 11 años, 37% coinfectados VIH/VHC). La mediana de estancia hospitalaria fue de 8 días (5-16), y la tasa de reingreso a los 30 días del 20,1%. Se observó un descenso significativo en el segundo periodo (2003-2013) de las hospitalizaciones motivadas por enfermedades infecciosas y trastornos psiquiátricos, y un incremento de aquellas relacionadas con neoplasias, enfermedad cardiovascular, gastrointestinal y enfermedades respiratorias crónicas. La mortalidad intrahospitalaria permanece elevada (6,8% en el primer periodo vs. 6,3% en el segundo), con un aumento progresivo de las muertes por enfermedades no definitorias de sida (37,9 vs. 68,3%; p < 0,001). La tasa de hospitalización disminuyó de manera significativa después de 1996 (4,9% anual), pero este descenso fue menos acusado en los pacientes coinfectados VIH/VHC (1,7% anual). Conclusiones. Las hospitalizaciones motivadas por enfermedades infecciosas y trastornos psiquiátricos han descendido; por el contrario, se observó un aumento significativo de aquellas relacionadas con neoplasias no definitorias de sida, enfermedad cardiovascular y enfermedades respiratorias crónicas. La mortalidad intrahospitalaria permanece a día de hoy elevada, pero a expensas fundamentalmente de enfermedades no definitorias de sida. La coinfección VIH/VHC incrementó los días de hospitalización y los reingresos durante el periodo de estudio.Instituto de Salud Carlos III; CPII14/00014Instituto de Salud Carlos III; PI10/02166Instituto de Salud Carlos III; PI13/02266Instituto de Salud Carlos III; CM13/0032

    The role of advanced practice nurses in creating the kidney transplant candidate care map (APN‑preKT): a convergent‑parallel mixed methods research protocol

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    Background: Waiting time for kidney transplants (KT) is an important health determinant for patients with chronic kidney disease (CKD). During this time, ongoing evaluation and participation is necessary in order to guarantee the quality and suitability of the proposed treatment. There is no existing literature on the potential impact of inclusion of an Advanced Practice Nurse (APN) role in the hospital setting on care for CKD patients who are candidates for KT. The main objectives of this protocol are: to analyse outpatient nursing activity in the care of individuals with KT in Spain; to identify the needs of individuals who are KT candidates; and to measure the impact of the APN role through patient outcomes and experiences. These objectives are fulfilled through 5 specific related substudies. Methods A convergent parallel mixed methods approach will be conducted between July 2021 and April 2024. Quantitative and qualitative data will be collected and analysed separately to ascertain whether the findings confirm or contradict one another. Each of the 5 substudies of the project require a specific design, sampling method, and data collection procedure in order to meet the overall objectives for the project. Discussion: The results of the project are expected to inform the design of future nursing roles and contribute to future improvements in the quality of care provided. The data that may be obtained from this protocol are limited to the specific context of the study facility and may be extrapolated but not compared to other settings due to the variability of care pathways for KT candidates internationally

    Clinical characteristics of chronic obstructive pulmonary disease in never-smokers: A systematic review

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    Introduction Chronic Obstructive Pulmonary Disease (COPD) is the third cause of death worldwide. While tobacco smoking is a key risk factor, COPD also occurs in never-smokers (NS). However, available evidence on risk factors, clinical characteristics, and natural history of the disease in NS is scarce. Here, we perform a systematic review of the literature to better describe the characteristics of COPD in NS. Methods We searched different databases following the PRISMA guidelines with explicit inclusion and exclusion criteria. A purpose-designed quality scale was applied to the studies included in the analysis. It was not possible to pool the results due to the high heterogeneity of the studies included. Results A total of 17 studies that met the selection criteria were included, albeit only 2 of them studied NS exclusively. The total number of participants in these studies were 57,146 subjects, 25,047 of whom were NS and 2,655 of the latter had NS-COPD. Compared to COPD in smokers, COPD in NS is more frequent in women and older ages, and is associated with a slightly higher prevalence of comorbidities. There are not enough studies to understand if COPD progression and clinical symptoms in NS are different to that of ever-smokers. Conclusions There is a significant knowledge gap on COPD in NS. Given that COPD in NS account for about a third of all COPD patients in the world, particularly in low-middle income countries, and the decrease in tobacco consumption in high income countries, understanding COPD in NS constitutes a public-health priorityThis work was supported by the Instituto de Salud Carlos III (ISCIII)/PI20/00476/Cofinanciado Unión Europea (UE-FEDER) and Grupo de referencia competitiva Xunta de GaliciaS

    Residential radon and characteristics of chronic obstructive pulmonary disease

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    It is not known whether residential radon exposure may be linked to the development of chronic obstructive pulmonary disease (COPD) and/or have an influence on the functional characteristics or exacerbations of COPD. The aim of this study was therefore to ascertain whether there might be an association between residential radon concentrations and certain characteristics of COPD. We analyzed COPD cases drawn from a case–control study conducted in an area of high radon exposure. Data were collected on spirometric pulmonary function variables, hospital admissions, and smoking. Radon measurements were taken using alpha-track-type CR-39 detectors individually placed in patients’ homes. All statistical analyses were performed using the IBM SPSS v22 computer software program. The study included 189 COPD cases (79.4% men; median age 64 years). The median radon concentration was 157 Bq/m3. No differences were found between radon concentration and sex, age or severity of breathing obstruction as measured by FEV1%. It should be noted, however, that 48.1% of patients with FEV1%  600 Bq/m3 exhibited no different characteristics in lung function. Exposure to radon does not appear to have an influence on the clinical characteristics of smokers and ex-smokers with COPD. As exposure to residential radon increases, there is no trend towards a worsening of FEV1%. Further studies are thus needed to analyze this possible association in never-smokers with COPDSpanish Society of Pneumology & Thoracic Surgery (Sociedad Española de Neumología y Cirugía Torácica—SEPAR), competitive Project Number 439, call 2018S

    Malignancies in HIV-infected patients: descriptive study of 129 cases between 1993 and 2010

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    [Resumen] Introducción: Uno de los problemas asociados a la infección por VIH es el desarrollo de neoplasias. La incidencia y espectro de los distintos cánceres se ha visto modificada con la incorporación del tratamiento anti-retroviral de gran actividad (TARGA). El objetivo del presente estudio es describir las características clínicas y epidemiológicas y el pronóstico de pacientes infectados con VIH que han desarrollado una neoplasia. Material y Métodos: Estudio observacional retrospectivo de una cohorte de pacientes con infección por VIH que desarrollaron algún cáncer en el periodo comprendido entre 1993-2010 en un hospital de referencia. Se compararon las variables entre los casos de neoplasias definitorias de SIDA (NDS) y no definitorios de SIDA (NNDS). Resultados: Se identificaron 125 pacientes con al menos una neoplasia. Los cánceres más frecuentes fueron: linfoma no Hodgkin (n: 39; 30,2%), sarcoma de Kaposi (n: 20; 15,5%), enfermedad de Hodgkin (n: 11; 8,8%), neoplasia pulmón (n: 20; 16%) y hepatocarcinoma (n: 9; 6,9 %). La edad media fue 42 ± 11 años, 84% varones, 55,8% estaban co-infectados por VHB y/o VHC. Las conductas de riesgo fueron: 45,6% usuarios de drogas vía parenteral, 16,8% hombres con relaciones sexuales con hombres y 20% heterosexuales. Se encontraron 67 NNDS (52%) y 62 (48%) NDS; los pacientes con NNDS presentaron mayor tiempo de evolución de la infección por VIH y de exposición a TARGA, mayor recuento de CD4 y mejor control virológico que los del grupo de NDS. Desarrollaron un segundo tumor cuatro pacientes. La supervivencia global fue de 34,7%. Conclusiones: Se constata un aumento en la incidencia de NNDS, que se presentan en pacientes con mejor control virológico e in-munológico que los NDS. La mortalidad de los pacientes con infección por VIH y enfermedad tumoral continúa siendo muy elevada.[Abstract] Introduction: The development of malignancies is a problem associated with HIV infection. The incidence and spectrum of malignancies has been modified with the addition of highly active antiretroviral therapy (HAART). Aim: To describe the clinical and epidemiological characteristics and prognosis of HIV patients who have developed a malignancy. Methods: Retrospective observational study was conducted in HIV + patients who developed a malignancy between 1993-2010 in a referral hospital. AIDS-defining malignancies (ADN) and non-AIDS-defining malignancies (NADN) were compared. Results: 125 patients were identified with at least one malignancy. The most frequent malignancies were: non-Hodgkin lymphoma (n; 39; 30.2%), Kaposi's sarcoma (n: 20; 15.5%), Hodgkin's disease (n: 11; 8.8%), lung cancer (n: 20; 15.5%) and hepatocellular carcinoma (n: 9; 6.9 %). The mean age was 42 ± 11 years, 84% male, 55.8% were coinfected with HBV and or HCV. The risk behaviors were: 45.6% intravenous drug users, 16.8% men who have sex with men and 20% heterosexuals). There were 67 (52%) NADN and 62 (48%) ADN; NADN patients had a longer story of HIV infection and longer exposure to HAART, better level of immunodeficiency and better virological control than ADN patients. Four patients developed a second malignancy. Overall survival was 34.7%. Conclusions: We found an increased incidence of NADN, appearing in patients with better virological and immunological control than ADN group. Mortality of patients with HIV infection and malignancy is still very high

    Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions

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    We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

    Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

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    Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe
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