178 research outputs found

    Characterizing zebra crossing zones using LiDAR data

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    Light detection and ranging (LiDAR) scanning in urban environments leads to accurate and dense three-dimensional point clouds where the different elements in the scene can be precisely characterized. In this paper, two LiDAR-based algorithms that complement each other are proposed. The first one is a novel profiling method robust to noise and obstacles. It accurately characterizes the curvature, the slope, the height of the sidewalks, obstacles, and defects such as potholes. It was effective for 48 of 49 detected zebra crossings, even in the presence of pedestrians or vehicles in the crossing zone. The second one is a detailed quantitative summary of the state of the zebra crossing. It contains information about the location, the geometry, and the road marking. Coarse grain statistics are more prone to obstacle-related errors and are only fully reliable for 18 zebra crossings free from significant obstacles. However, all the anomalous statistics can be analyzed by looking at the associated profiles. The results can help in the maintenance of urban roads. More specifically, they can be used to improve the quality and safety of pedestrian routesConsellería de Cultura, Educación e Ordenación Universitaria, Grant/Award Numbers: accreditation 2019-2022 ED431G-2019/04, 2022-2024, ED431C2022/16, ED481A-2020/231; European Regional Development Fund (ERDF); CiTIUS-Research Center in Intelligent Technologies of the University of Santiago de Compostela as a Research Center of the Galician University System; Ministry of Economy and Competitiveness, Government of Spain, Grant/Award Number: PID2019-104834GB-I00; National Department of Traffic (DGT) through the project Analysis of Indicators Big-Geodata on Urban Roads for the Dynamic Design of Safe School Roads, Grant/Award Number: SPIP2017-02340S

    Optical imaging spectroscopy for rapid, primary screening of SARS-CoV-2: a proof of concept

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    Effective testing is essential to control the coronavirus disease 2019 (COVID-19) transmission. Here we report a-proof-of-concept study on hyperspectral image analysis in the visible and near-infrared range for primary screening at the point-of-care of SARS-CoV-2. We apply spectral feature descriptors, partial least square-discriminant analysis, and artificial intelligence to extract information from optical diffuse reflectance measurements from 5 µL fluid samples at pixel, droplet, and patient levels. We discern preparations of engineered lentiviral particles pseudotyped with the spike protein of the SARS-CoV-2 from those with the G protein of the vesicular stomatitis virus in saline solution and artificial saliva. We report a quantitative analysis of 72 samples of nasopharyngeal exudate in a range of SARS-CoV-2 viral loads, and a descriptive study of another 32 fresh human saliva samples. Sensitivity for classification of exudates was 100% with peak specificity of 87.5% for discernment from PCR-negative but symptomatic cases. Proposed technology is reagent-free, fast, and scalable, and could substantially reduce the number of molecular tests currently required for COVID-19 mass screening strategies even in resource-limited settings.Ministerio de Ciencia e Innovación, 2020 Emergency Call for Research Projects about the SARS-CoV-2 virus and the COVID-19 disease Instituto de Salud Carlos III by Grant Number EQC2019-006240-PComisión Europea, Joint Research Center (JRC) HUMAINT project

    El efecto de la distribución a priori en modelos con frontera estocástica. Comparación con máxima verosimilitud.

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    Recoge los contenidos presentados a: ASEPELT España. Reunión anual (28. 2014. Málaga).En este trabajo se analizan y comparan las propiedades de los estimadores máximo verosímil y bayesiano en el modelo de producción con frontera estocástica a través de un estudio de tipo Monte Carlo. En el caso bayesiano, se presta especial atención al efecto que tiene la elección del hiperparámetro que determina la eficiencia mediana de la distribución a priori. Los resultados muestran un mejor comportamiento de la estimación bayesiana, salvo en el caso poco probable de que se asigne un hiperparámetro muy alejado del valor real de la población.In this paper, the maximum likelihood and the Bayesian methodologies are analysed and compared through a Monte Carlo study in the setting of half–normal stochastic frontier production models. In the Bayesian case, special emphasis is placed on the effect that the choice of the hyperparameter that determines the prior median efficiency has on the estimations. The results show a better behaviour of the Bayesian estimation, except in the unlikely case in which researchers assign a value to the aforementioned hyperparameter which greatly differs from its actual value

    El efecto de la distribución a priori en modelos con frontera estocástica. Comparación con máxima similitud.

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    Recoge los contenidos presentados a: ASEPELT España. Reunión anual (28. 2014. Málaga).En este trabajo se analizan y comparan las propiedades de los estimadores máximo verosímil y bayesiano en el modelo de producción con frontera estocástica a través de un estudio de tipo Monte Carlo. En el caso bayesiano, se presta especial atención al efecto que tiene la elección del hiperparámetro que determina la eficiencia mediana de la distribución a priori. Los resultados muestran un mejor comportamiento de la estimación bayesiana, salvo en el caso poco probable de que se asigne un hiperparámetro muy alejado del valor real de la población.In this paper, the maximum likelihood and the Bayesian methodologies are analysed and compared through a Monte Carlo study in the setting of half–normal stochastic frontier production models. In the Bayesian case, special emphasis i placed on the effect that the choice of the hyperparameter that determines the prior median efficiency has on the estimations. The results show a better behaviour of the Bayesian estimation, except in the unlikely case in which researchers assign a value to the aforementioned hyperparameter which greatly differs from its actual value

    Coronary Artery Disease and Prognosis of Heart Failure with Reduced Ejection Fraction.

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    Our aim was to determine the prognostic impact of coronary artery disease (CAD) on heart failure with reduced ejection fraction (HFrEF) mortality and readmissions. From a prospective multicenter registry that included 1831 patients hospitalized due to heart failure, 583 had a left ventricular ejection fraction of <40%. In total, 266 patients (45.6%) had coronary artery disease as main etiology and 137 (23.5%) had idiopathic dilated cardiomyopathy (DCM), and they are the focus of this study. Significant differences were found in Charlson index (CAD 4.4 ± 2.8, idiopathic DCM 2.9 ± 2.4, p < 0.001), and in the number of previous hospitalizations (1.1 ± 1, 0.8 ± 1.2, respectively, p = 0.015). One-year mortality was similar in the two groups: idiopathic DCM (hazard ratio [HR] = 1), CAD (HR 1.50; 95% CI 0.83-2.70, p = 0.182). Mortality/readmissions were also comparable: CAD (HR 0.96; 95% CI 0.64-1.41, p = 0.81). Patients with idiopathic DCM had a higher probability of receiving a heart transplant than those with CAD (HR 4.6; 95% CI 1.4-13.4, p = 0.012). The prognosis of HFrEF is similar in patients with CAD etiology and in those with idiopathic DCM. Patients with idiopathic DCM were more prone to receive heart transplant.This research was funded by CIBERCV I and supported by the Instituto de Salud Carlos III. L.V. is funded by the Instituto de Salud Carlos III, Spain (CM20/00104 and ).S

    Ajustando RFR por Preditores de Discordância, “The Adjusted RFR”: Uma Metodologia Alternativa para Melhorar a Capacidade Diagnóstica de Índices Coronarianos

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    Background: Cutoff thresholds for the "resting full-cycle ratio" (RFR) oscillate in different series, suggesting that population characteristics may influence them. Likewise, predictors of discordance between the RFR and fractional flow reserve (FFR) have been documented. The RECOPA Study showed that diagnostic capacity is reduced in the RFR "grey zone", requiring the performance of FFR to rule out or confirm ischemia. Objectives: To determine predictors of discordance, integrate the information they provide in a clinical-physiological index, the "Adjusted RFR", and compare its agreement with the FFR. Methods: Using data from the RECOPA Study, predictors of discordance with respect to FFR were determined in the RFR "grey zone" (0.86 to 0.92) to construct an index ("Adjusted RFR") that would weigh RFR together with predictors of discordance and evaluate its agreement with FFR. Results: A total of 156 lesions were evaluated in 141 patients. Predictors of discordance were: chronic kidney disease, previous ischemic heart disease, lesions not involving the anterior descending artery, and acute coronary syndrome. Though limited, the "Adjusted RFR" improved the diagnostic capacity compared to the RFR in the "grey zone" (AUC-RFR = 0.651 versus AUC-"Adjusted RFR" = 0.749), also showing an improvement in all diagnostic indices when optimal cutoff thresholds were established (sensitivity: 59% to 68%; specificity: 62% to 75%; diagnostic accuracy: 60% to 71%; positive likelihood ratio: 1.51 to 2.34; negative likelihood ratio: 0.64 to 0.37). Conclusions: Adjusting the RFR by integrating the information provided by predictors of discordance to obtain the "Adjusted RFR" improved the diagnostic capacity in our population. Further studies are required to evaluate whether clinical-physiological indices improve the diagnostic capacity of RFR or other coronary indices.Fundamento: Os limiares de corte para a “relação do ciclo completo de repouso” (RFR) oscilam em diferentes séries, sugerindo que as características da população podem influenciá-los. Da mesma forma, foram documentados preditores de discordância entre a RFR e a reserva de fluxo fracionado (FFR). O Estudo RECOPA, mostrou que a capacidade diagnóstica está reduzida na “zona cinzenta” da RFR, tornando necessária a realização de FFR para descartar ou confirmar isquemia. Objetivos: Determinar os preditores de discordância, integrar as informações que eles fornecem em um índice clínico-fisiológico: a “RFR Ajustada”, e comparar sua concordância com o FFR. Métodos: Usando dados do Estudo RECOPA, os preditores de discordância em relação à FFR foram determinados na “zona cinzenta” da RFR (0,86 a 0,92) para construir um índice (“RFR Ajustada”) que pesaria a RFR juntamente com os preditores de discordância e avaliar sua concordância com a FFR. Resultados: Foram avaliadas 156 lesões em 141 pacientes. Os preditores de discordância foram: doença renal crônica, cardiopatia isquêmica prévia, lesões não envolvendo a artéria descendente anterior esquerda e síndrome coronariana aguda. Embora limitada, a “RFR Ajustada” melhorou a capacidade diagnóstica em comparação com a RFR na “zona cinzenta” (AUC-RFR = 0,651 versus AUC-“RFR Ajustada” = 0,749), mostrando também uma melhora em todos os índices diagnósticos quando foram estabelecidos limiares de corte otimizados (sensibilidade: 59% a 68%; especificidade: 62% a 75%; acurácia diagnóstica: 60% a 71%; razão de verossimilhança positiva: 1,51 a 2,34; razão de verossimilhança negativa: 0,64 a 0,37). Conclusões: Ajustar a RFR integrando as informações fornecidas pelos preditores de discordância para obter a “RFR Ajustada” melhorou a capacidade diagnóstica em nossa população. Mais estudos são necessários para avaliar se os índices clínico-fisiológicos melhoram a capacidade diagnóstica da RFR ou de outros índices coronarianos

    Modulation of higher-order olfaction components on executive functions in humans

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    The prefrontal (PFC) and orbitofrontal cortex (OFC) appear to be associated with both exec- utive functions and olfaction. However, there is little data relating olfactory processing and executive functions in humans. The present study aimed at exploring the role of olfaction on executive functioning, making a distinction between primary and more cognitive aspects of olfaction. Three executive tasks of similar difficulty were used. One was used to assess hot executive functions (Iowa Gambling Task-IGT), and two as a measure of cold executive functioning (Stroop Colour and Word Test-SCWT and Wisconsin Card Sorting Test- WCST). Sixty two healthy participants were included: 31 with normosmia and 31 with hyposmia. Olfactory abilities were assessed using the '' Sniffin ' Sticks '' test and the olfactory threshold, odour discrimination and odour identification measures were obtained. All partici- pants were female, aged between 18 and 60. Results showed that participants with hypos- mia displayed worse performance in decision making (IGT; Cohen ' s- d = 0.91) and cognitive flexibility (WCST; Cohen ' s- d between 0.54 and 0.68) compared to those with normosmia. Multiple regression adjusted by the covariates participants ' age and education level showed a positive association between odour identification and the cognitive inhibition response (SCWT-interference; Beta = 0.29; p = .034). The odour discrimination capacity was not a predictor of the cognitive executive performance. Our results suggest that both hot and cold executive functions seem to be associated with higher-order olfactory functioning in humans. These results robustly support the hypothesis that olfaction and executive mea- sures have a common neural substrate in PFC and OFC, and suggest that olfaction might be a reliable cognitive marker in psychiatric and neurologic disorders

    Decision making impairment: A shared vulnerability in obesity, gambling disorder and substance use disorders?

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    Introduction: Addictions are associated with decision making impairments. The present study explores decision making in Substance use disorder (SUD), Gambling disorder (GD) and Obesity (OB) when assessed by Iowa Gambling Task (IGT) and compares them with healthy controls (HC). Methods: For the aims of this study, 591 participants (194 HC, 178 GD, 113 OB, 106 SUD) were assessed according to DSM criteria, completed a sociodemographic interview and conducted the IGT. Results: SUD, GD and OB present impaired decision making when compared to the HC in the overall task and task learning, however no differences are found for the overall performance in the IGT among the clinical groups. Results also reveal some specific learning across the task patterns within the clinical groups: OB maintains negative scores until the third set where learning starts but with a less extend to HC, SUD presents an early learning followed by a progressive although slow improvement and GD presents more random choices with no learning. Conclusions: Decision making impairments are present in the studied clinical samples and they display individual differences in the task learning. Results can help understanding the underlying mechanisms of OB and addiction behaviors as well as improve current clinical treatments

    Adenovirus-vectored African Swine Fever Virus Antigens Cocktail Is Not Protective against Virulent Arm07 Isolate in Eurasian Wild Boar

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    African swine fever (ASF) is a viral disease of domestic and wild suids for which there is currently no vaccine or treatment available. The recent spread of ASF virus (ASFV) through Europe and Asia is causing enormous economic and animal losses. Unfortunately, the measures taken so far are insufficient and an effective vaccine against ASFV needs to be urgently developed. We hypothesized that immunization with a cocktail of thirty-five rationally selected antigens would improve the protective efficacy of subunit vaccine prototypes given that the combination of fewer immunogenic antigens (between 2 and 22) has failed to elicit protective efficacy. To this end, immunogenicity and efficacy of thirty-five adenovirus-vectored ASFV antigens were evaluated in wild boar. The treated animals were divided into different groups to test the use of BioMize adjuvant and different inoculation strategies. Forty-eight days after priming, the nine treated and two control wild boar were challenged with the virulent ASFV Arm07 isolate. All animals showed clinical signs and pathological findings consistent with ASF. This lack of protection is in line with other studies with subunit vaccine prototypes, demonstrating that there is still much room for improvement to obtain an effective subunit ASFV vaccine

    Hyperspectral image processing for the identification and quantification of lentiviral particles in fluid samples

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    Optical spectroscopic techniques have been commonly used to detect the presence of biofilm-forming pathogens (bacteria and fungi) in the agro-food industry. Recently, near-infrared (NIR) spectroscopy revealed that it is also possible to detect the presence of viruses in animal and vegetal tissues. Here we report a platform based on visible and NIR (VNIR) hyperspectral imaging for non-contact, reagent free detection and quantification of laboratory-engineered viral particles in fluid samples (liquid droplets and dry residue) using both partial least square-discriminant analysis and artificial feed-forward neural networks. The detection was successfully achieved in preparations of phosphate buffered solution and artificial saliva, with an equivalent pixel volume of 4 nL and lowest concentration of 800 TU.mu L-1. This method constitutes an innovative approach that could be potentially used at point of care for rapid mass screening of viral infectious diseases and monitoring of the SARS-CoV- 2 pandemic.This research was funded by grants number COV20-00080 and COV20-00173 of the 2020 Emergency Call for Research Projects about the SARS-CoV-2 virus and the COVID-19 disease of the Institute of Health 'Carlos III', Spanish Ministry of Science and Innovation, and by grant number EQC2019-006240-P of the 2019 Call for Acquisition of Scientific Equipment, FEDER Program, Spanish Ministry of Science and Innovation. This work has been supported by the European Commission through the JRC HUMAINT project. ABR was supported by grant number RTI2018-094465-J funded by the Spanish National Agency of Research. The authors would like to gratefully acknowledge the assistance of the members of the EOD-CBRN Group of the Spanish National Police, whose identities cannot be disclosed, and who are represented here by JMNG. Authors thank continuous support from their institutions
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