BackgroundPopulation distribution of reduced diffusing capacity of the lungs for carbon monoxide (DLCO) in smokers and main consequences are not properly recognised. The objectives of this study were ...to describe the prevalence of reduced DLCO in a population-based sample of current and former smoker subjects without airflow limitation and to describe its morphological, functional and clinical implications.MethodsA sample of 405 subjects aged 40 years or older with postbronchodilator forced expiratory volume in 1 s/forced vital capacity (FVC) >0.70 was obtained from a random population-based sample of 9092 subjects evaluated in the EPISCAN II study. Baseline evaluation included clinical questionnaires, exhaled carbon monoxide (CO) measurement, spirometry, DLCO determination, 6 min walk test, routine blood analysis and low-dose CT scan with evaluation of lung density and airway wall thickness.ResultsIn never, former and current smokers, prevalence of reduced DLCO was 6.7%, 14.4% and 26.7%, respectively. Current and former smokers with reduced DLCO without airflow limitation were younger than the subjects with normal DLCO, and they had greater levels of dyspnoea and exhaled CO, greater pulmonary artery diameter and lower spirometric parameters, 6 min walk distance, daily physical activity and plasma albumin levels (all p<0.05), with no significant differences in other chronic respiratory symptoms or CT findings. FVC and exhaled CO were identified as independent risk factors for low DLCO.ConclusionReduced DLCO is a frequent disorder among smokers without airflow limitation, associated with decreased exercise capacity and with CT findings suggesting that it may be a marker of smoking-induced early vascular damage.Trial registration numberNCT03028207.
Understanding the temporal dynamics and spatial distribution of natural seepage phenomena in the Gulf of Mexico is fundamental for the definition of proper environmental management practices in this ...often cloud-covered region. RADARSAT-1 images analyzed in this paper were acquired using the wide 1 and wide 2 (W1, W2) and ScanSAR narrow 1 (SCN1) beam modes. Image processing was carried out using the unsupervised semivariogram textural classifier (USTC). In combination with RADARSAT-1 satellite images, and essential ancillary data, this technology enhances the detection of seepage slicks on the ocean surface based on radar texture. USTC classification of RADARSAT-1 data provided systematic evidence from space of the presence of prolific, present-day petroleum generation and migration in the Cantarell Complex of oil fields.
Air pollution continues to be a significant risk to public health. It is an important issue that affects everyone and should be studied to take actions that help mitigate the risk. This research's ...main objective is to explore air quality from 2010 to 2018 in metropolitan zones of Guadalajara, Monterrey, and the Valley of Mexico. Air quality is analyzed based on the concentrations of criteria pollutants: carbon monoxide (CO), nitrogen dioxide (NO 2 ), ozone (O 3 ), particulate matter less than or equal to 2.5 micrometers (PM 2.5 ), particulate matter less than or equal to 10 micrometers (PM 10 ), and sulfur dioxide (SO 2 ). In this paper, six stages are proposed:1) data collection; 2) data cleansing; 3) descriptive analysis. 4) design of cluster analysis models and main components; 5) application of machine learning models; 6) interpretation and analysis of results. This study has concluded that higher mean hourly concentrations for pollutants, CO, NO 2 , O 3 , PM 2.5 , and SO 2 were found in Guadalajara Metropolitan Zone. In contrast, the highest mean hourly concentration of PM 10 was found in the Monterrey Metropolitan Zone. Furthermore, the pollutant with the highest effect in the three critical zones was PM 2.5 , presenting high concentrations with hazardous air quality levels. Finally, the area with the worst air quality was Guadalajara Metropolitan Zone.
In this work, a watermark detection system for audio signals in temporal domain is proposed, the watermark embedding algorithm is the multiplicative embedding rule and the optimal detection equation ...is derived for this constraints using the maximum likelihood (ML) criterion. The optimal threshold equation is also derived using the Neyman-Person criterion and the resulting system is blind and has very low complexity. Computer simulations were performed applying the proposed model to audio signals and results show that the proposed system is semi fragile since it is able to detect watermarks if the watermarked object was severely attacked by noise, low pass filtering among other attacks but is not capable of detecting watermarks for others attacks such MP3 compression.
Optimal detection of multiplicative watermarks in Laplacian channels Gonzalez-Lee, M.; Morales-Mendoza, L. J.; Vazquez-Bautista, R. F. ...
2012 9th International Conference on Electrical Engineering, Computing Science and Automatic Control (CCE),
2012-Sept.
Conference Proceeding
In this work, we propose a model for an optimal detector of digital watermarks for Laplacian channels, the watermark embedding algorithm is the multiplicative embedding rule in time domain, the ...optimal detection equation and the threshold equation are derived using maximum likelihood (ML) and Neyman-Pearson criterion. The resulting system is blind and has very low complexity. Computer simulations are carried out applying the proposed model to audio signals and results prove that the proposed system is able to detect watermarks even if the watermarked object was severely attacked by noise, low pass filtering among other attacks.
La información actualizada sobre la representatividad geográfica y taxonómica de los ejemplares depositados en 28 colecciones mastozoológicas mexicanas y la disponible en las bases de datos Mammal ...Networked Information System (MaNIS), y de la Unidad de Informática para la Biodiversidad (UNIBIO) se recopiló con el fin de analizar y comparar el estado actual de los ejemplares de mamíferos mexicanos depositados en colecciones de Norteamérica. Se documentaron un total de 421,466 ejemplares de mamíferos depositados en 120 colecciones mastozoológicas, de los cuales 233,116 ejemplares se encuentran en colecciones de Estados Unidos de América y Canadá, y 188,350 ejemplares en colecciones de México. Las colecciones con el mayor número de ejemplares de mamíferos de México son la Colección Nacional de Mamíferos (CNMA 46,000), la Universidad de Kansas (KU 44,301), y la Escuela Nacional de Ciencias Biológicas (ENCB 43,985). En colecciones mexicanas, los estados del norte de México están escasamente representados en número de ejemplares (< 3,000), y en las colecciones extranjeras, los estados del centro de México están pobremente representados. Los estados mexicanos mejor representados por número de ejemplares (> 10,000) son Baja California Sur, Chiapas, Oaxaca, Puebla y Veracruz. Los órdenes mejor representados por el número de ejemplares son Rodentia y Chiroptera (234,978 y 120,956, respectivamente). Los estados mexicanos con menor extensión territorial tienen la mayor densidad de ejemplares colectados (ejemplares/km²): Distrito Federal (3.2), Tlaxcala (1.4), Colima (1.06) y Morelos (0.9). Se espera contar con una línea base que permita establecer estrategias adecuadas para completar el inventario nacional de los mamíferos mexicanos, y lograr que este patrimonio natural este adecuadamente representado en colecciones de México.
Fractional calculus is a promising and rich area of study as many applications to engineering are under development. As a result, many authors proposed new approaches for solving diverse problems ...with success. In particular, we focus on revisiting a problem in the digital watermarking field: the detection of Gaussian watermarks in the spatial domain. The novelty of this work is that we show that the use of fractional calculus principles reduces the false positive rate of a Gaussian watermarks detector whereas keeping the complexity of the system almost low. Most systems detect Gaussian watermarks using different strategies that increase the system complexity, this motivates our work which goal is to address the detection problem with a simpler approach.
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