Assessment of variations in air quality in cities of Ecuador in relation to the lockdown due to the COVID-19 pandemic.

This study analyzes the effect of lockdown due to COVID-19 on the spatiotemporal variability of ozone (O3), sulfur dioxide (SO2), and nitrogen dioxide (NO2) concentrations in different provinces of continental Ecuador using satellite information from Sentinel - 5P. The statistical analysis includes data from 2018 to March 2021 and was performed based on three periods defined a priori: before, during, and after lockdown due to COVID-19, focusing on the provinces with the highest concentrations of the studied gases (hotspots). The results showed a significant decrease in NO2 concentrations during the COVID-19 lockdown period in all the study areas: the Metropolitan District of Quito (DMQ) and the provinces of Guayas and Santo Domingo de los Tsáchilas. In the period after lockdown, NO2 concentrations increased by over 20% when compared to the pre-lockdown period, which may be attributable to a shift towards private transportation due to health concerns. On the other hand, SO2 concentrations during the lockdown period showed irregular, non-significant variations; however, increases were observed in the provinces of Chimborazo, Guayas, Santa Elena, and Morona Santiago, which could be partly attributed to the eruptive activity of the Sangay volcano during 2019-2020. Conversely, O3 concentrations increased by 2-3% in the study areas; this anomalous behavior could be attributed to decreased levels of NOx, which react with ozone, reducing its concentration. Finally, satellite data validation using the corresponding data from monitoring stations in the DMQ showed correlation values of 0.9 for O3 data and 0.7 for NO2 data, while no significant correlation was found for SO2.

Quantitative assessment of the valorisation of used cooking oils in 23 countries.

The article quantifies, in a set of 23 countries, the amounts consumed of vegetable oils, the amounts of used oils produced after cooking, the amounts available for valorisation, and finally the quantities being valorised. The management practices adopted are also reviewed. Based on data collected, a production factor, relating vegetable oil consumption with used cooking oil production, of 0.32 is proposed. The valorisation factor, which quantifies the fraction of UCO being valorised, is higher in better performing countries (0.749) and worst in the remaining (0.232). Three consumption-valorisation factors, relating consumption with valorisation, were obtained: for high performing countries (0.274); intermediate performing (0.105); and under-performing (0.078). The management systems adopted by the different countries are based on either second-generation economic instruments (USA and Brazil), or on third-generation economic instruments (EU, Argentina, Japan). The former has allowed countries to attain better valorisation rates.

Quantification of health risks in Ecuadorian population due to dietary ingestion of arsenic in rice.

In Ecuador alone, 500,000 people in rural areas are estimated to have been exposed to high concentrations of As from water and food, but no quantitative evaluation of health risk has yet been made. The present study quantifies exposure and health risk for the Ecuadorian population from the ingestion of arsenic in white rice. Estimated exposure is correlated with published data on tap water quality and biomarkers of exposure for the population of two towns in the metropolitan area of Quito. Estimated daily intake (EDI) of arsenic for infants living in urban areas of Ecuador is around four times that of European infants, being equal for those livings in rural areas. EDI for the population as a whole is almost twice that of Europe, but between a half and a third of that of Brazil, Bangladesh, and India. Estimated excess lifetime risk (ELTR) for adults is 3 per 10,000, while for infants varies between 10 per 10,000 in rural areas and 20 per 10,000 in urban areas. Future research on arsenic impacts on human health in Ecuador should consider in particular poor populations living in regions where environmental arsenic concentrations are highest, including cross-sectional and longitudinal epidemiologic studies.

Toxicokinetics and tissue distribution of cadmium-based Quantum Dots in the marine mussel Mytilus galloprovincialis.

Environmental health hazards of Quantum Dots (QDs) are of emergent concern, but limited data is available about their toxicokinetics (TK) and tissue distribution in marine bivalves. This study investigated the QDs behavior in seawater, their TK and tissue distribution in Mytilus galloprovincialis, in comparison with soluble Cd. Mussels were exposed to CdTe QDs and soluble Cd for 21 days at 10 µgCd L(-1) followed by a 50 days depuration. TK of QDs in mussels is related to the homo-aggregate uptake, surface charge, aggregation and precipitation as key factors. There were tissue- and time-dependent differences in the TK of both Cd forms, and soluble Cd is the most bioavailable form. Digestive gland is a preferential site for QDs storage and both Cd forms are not eliminated by mussels (t1/2>50 days). Results indicate that the TK model of CdTe QDs in marine mussels is distinct from their soluble counterparts.

Quantitative performance targets by using balanced scorecard system: application to waste management and public administration.

This article demonstrates how decision-makers can be guided in the process of defining performance target values in the balanced scorecard system. We apply a method based on sensitivity analysis with Monte Carlo simulation to the municipal solid waste management system in Loulé Municipality (Portugal). The method includes two steps: sensitivity analysis of performance indicators to identify those performance indicators with the highest impact on the balanced scorecard model outcomes; and sensitivity analysis of the target values for the previously identified performance indicators. Sensitivity analysis shows that four strategic objectives (IPP1: Comply with the national waste strategy; IPP4: Reduce nonrenewable resources and greenhouse gases; IPP5: Optimize the life-cycle of waste; and FP1: Meet and optimize the budget) alone contribute 99.7% of the variability in overall balanced scorecard value. Thus, these strategic objectives had a much stronger impact on the estimated balanced scorecard outcome than did others, with the IPP1 and the IPP4 accounting for over 55% and 22% of the variance in overall balanced scorecard value, respectively. The remaining performance indicators contribute only marginally. In addition, a change in the value of a single indicator's target value made the overall balanced scorecard value change by as much as 18%. This may lead to involuntarily biased decisions by organizations regarding performance target-setting, if not prevented with the help of methods such as that proposed and applied in this study.

Coverage methods for early groundwater contamination detection.

A method based on space-filling coverage designs to optimize groundwater monitoring networks for plume detection and quantification is proposed. Space-filling objective functions are then compared with more classical functions. The method was applied to a hypothetical case-study with 160 candidate locations, resulting in final optimal design monitoring networks with 40 locations. Results show that the method is superior to those based strictly on the probability of contamination detection for quantifying maximum and mean values. In the light of these results fractal properties of space-filling coverage methods and of simulated annealing are also discussed.

Mental workload and visual impairment: differences between pupil, blink, and subjective rating.

This research has two aims: (a) To study the concurrent validity of three measures of mental workload, NASA TLX rating scale, pupil dilation and blink rate, testing the hypothesis that they will provide convergent results using a single-task, and dissociative results for dual-task; and (b) To analyse their capability to predict visual search impairment. These three measures were analyzed in the same cognitive tasks in single-task and dual-task (cognitive task and visual search) conditions in a within-subjects experiment with twenty-nine participants. Mental workload measures showed concurrent validity under single-task condition, but a complex pattern of results arose in the dual-task condition: it is suggested that NASA TLX would be a subjective addition of the rating of each task; pupil dilation would measure the average arousal underlying the cognitive tasks; and the blink rate would produce opposite effects: whereas mental workload of cognitive tasks would increase blink rate, visual demand would inhibit it. All three measures were good predictors of visual impairment. The soundness of these measures is discussed with regard to the applied field of driving and other activities.

Mental Workload and Visual Impairment: Differences between Pupil, Blink, and Subjective Rating

This research has two aims: (a) To study the concurrent validity of three measures of mental workload, NASA TLX rating scale, pupil dilation and blink rate, testing the hypothesis that they will provide convergent results using a single-task, and dissociative results for dual-task; and (b) To analyse their capability to predict visual search impairment. These three measures were analyzed in the same cognitive tasks in single task and dual-task (cognitive task and visual search) conditions in a within-subjects experiment with twenty-nine participants. Mental workload measures showed concurrent validity under single-task condition, but a complex pattern of results arose in the dual task condition: it is suggested that NASA TLX would be a subjective addition of the rating of each task; pupil dilation would measure the average arousal underlying the cognitive tasks; and the blink rate would produce opposite effects: whereas mental workload of cognitive tasks would increase blink rate, visual demand would inhibit it. All three measures were good predictors of visual impairment. The soundness of these measures is discussed with regard to the applied field of driving and other activities (AU)

Este experimento tiene dos objetivos: 1) Estudiar la validez concurrente de tres medidas de carga mental, la escala de juicios NASA TLX, la dilatación de la pupila y la tasa de parpadeo, poniendo a prueba la hipótesis de que, en situaciones de tarea única, arrojan resultados convergentes, pero, en doble tarea, arrojan resultados disociativos. 2) Analizar su capacidad para predecir el deterioro en la búsqueda visual. Las tres medidas fueron analizadas con las mismas tareas cognitivas realizadas en condiciones de tarea simple y de doble tarea (tarea cognitiva y búsqueda visual) en un experimento intrasujetos con veintinueve participantes. Las medidas de carga mental mostraron validez concurrente en las condiciones de tarea única, pero en las condiciones de doble tarea apareció un patrón de resultados complejo que sugiere que NASA TLX consistiría en la adición subjetiva de los juicios de cada tarea; la dilatación de la pupila mediría la activación promedio que subyace a las tareas cognitivas; y la tasa de parpadeo produciría efectos contrapuestos: mientras que la carga mental de las tareas cognitivas incrementa la tasa de parpadeo, las demandas visuales la inhiben. Las tres medidas fueros buenos predictores del deterioro visual. Se discute la justificación del uso de estas medidas en el campo aplicado de la conducción y otras actividades (AU)

Estimation of arrival time in vehicle and video / Estimación del tiempo de llegada en vehículo y vídeo

The equivalence of arrival-time estimations performed in vehicle and using video images was studied. The design consisted in 2 Sexes x (2 Tests x 4 Speeds x 4 Distances). The participants, 20 men and 20 women, seated in the front passenger’s seat of an automobile and temporarily deprived of sight, estimated the car’s arrival time at targets. The times to be estimated were generated by varying 4 speeds by 4 distances. The same subjects estimated the same arrival times in a video, filmed from the same position and scenario. Findings indicated high equivalence of vehicle and video in experimental results (underestimation of time, increase of errors with the time to be estimated). However, when considered individual skills, both estimations had a moderate relationship (r= .52), which, for applied purposes, does not justify substituting estimation in vehicles with that performed using videos

Se estudia la equivalencia entre las estimaciones de tiempo de llegada realizadas en un automóvil y las realizadas en imágenes de vídeo. Los participantes, 20 hombres y 20 mujeres, sentados en el asiento del acompañante de un automóvil y privados temporalmente de visión, estiman el tiempo de llegada del automóvil a unas dianas. Los tiempos se generan variando ortogonalmente 4 velocidades y 4 distancias. Los mismos sujetos estiman los mismos tiempos de llegada en un vídeo tomado desde esa misma posición y escenario. Los resultados indican una alta equivalencia entre ambos métodos en los resultados experimentales; sin embargo, consideradas como habilidades individuales, ambas estimaciones tienen una relación moderada (r= .52) que para propósitos aplicados no justifica la sustitución de la estimación en automóvil por la estimación en vídeo