Model-based reinforcement learning is a powerful paradigm for learning tasks in robotics. However, in-depth exploration is usually required and the actions have to be known in advance. Thus, we ...propose a novel algorithm that integrates the option of requesting teacher demonstrations to learn new domains with fewer action executions and no previous knowledge. Demonstrations allow new actions to be learned and they greatly reduce the amount of exploration required, but they are only requested when they are expected to yield a significant improvement because the teacher's time is considered to be more valuable than the robot's time. Moreover, selecting the appropriate action to demonstrate is not an easy task, and thus some guidance is provided to the teacher. The rule-based model is analyzed to determine the parts of the state that may be incomplete, and to provide the teacher with a set of possible problems for which a demonstration is needed. Rule analysis is also used to find better alternative models and to complete subgoals before requesting help, thereby minimizing the number of requested demonstrations. These improvements were demonstrated in a set of experiments, which included domains from the international planning competition and a robotic task. Adding teacher demonstrations and rule analysis reduced the amount of exploration required by up to 60% in some domains, and improved the success ratio by 35% in other domains.
Hydrogen production from water electrolysis is a key enabling energy storage technology for the large-scale deployment of intermittent renewable energy sources. Proton ceramic electrolysers (PCEs) ...can produce dry pressurized hydrogen directly from steam, avoiding major parts of cost-driving downstream separation and compression. However, the development of PCEs has suffered from limited electrical efficiency due to electronic leakage and poor electrode kinetics. Here, we present the first fully operational BaZrO
-based tubular PCE, with 10 cm
active area and a hydrogen production rate above 15 Nml min
. The novel steam anode Ba
Gd
La
Co
O
exhibits mixed p-type electronic and protonic conduction and low activation energy for water splitting, enabling total polarization resistances below 1 Ω cm
at 600 °C and Faradaic efficiencies close to 100% at high steam pressures. These tubular PCEs are mechanically robust, tolerate high pressures, allow improved process integration and offer scale-up modularity.
Background There is growing concern that prenatal exposure to bisphenol A (BPA) and phthalates, which are widely used in consumer products, might affect susceptibility to infections and the ...development of allergy and asthma in children, but there are currently very few prospective studies. Objective We sought to evaluate whether prenatal exposure to BPA and phthalates increases the risk of respiratory and allergic outcomes in children at various ages from birth to 7 years. Methods We measured BPA and metabolites of high-molecular-weight phthalates, 4 di-(2-ethylhexyl) phthalate (DEHP) metabolites (Σ4 DEHP) and mono-benzyl phthalate (MBzP), and 3 low-molecular-weight phthalate (LMWP) metabolites (Σ3 LMWP) in urine samples collected during the first and third trimesters in pregnant women participating in the Infancia y Medio Ambiente–Sabadell birth cohort study. The occurrence of chest infections, bronchitis, wheeze, and eczema in children was assessed at ages 6 and 14 months and 4 and 7 years through questionnaires given to the mothers. Atopy (specific IgE measurement) and asthma (questionnaire) were assessed at ages 4 and 7 years, respectively. Results The relative risks (RRs) of wheeze (RR, 1.20; 95% CI, 1.03-1.40; P = .02), chest infections (RR, 1.15; 95% CI, 1.00-1.32; P = .05), and bronchitis (RR, 1.18; 95% CI, 1.01-1.37; P = .04) at any age increased for each doubling in concentration of maternal urinary BPA. Σ4 DEHP metabolites were associated with the same outcomes (wheeze: RR, 1.25; 95% CI, 1.04-1.50, P = .02; chest infections: RR, 1.15; 95% CI, 0.97-1.35; P = .11; bronchitis: RR, 1.20; 95% CI, 1.01-1.43; P = .04). MBzP was associated with higher risk of wheeze (RR, 1.15; 95% CI, 1.00-1.33; P = .05). The risk of asthma at age 7 years was also increased with increasing prenatal BPA, Σ4 DEHP, and MBzP exposure. There were no other exposure-outcome associations. Conclusions Prenatal exposure to BPA and high-molecular-weight phthalates might increase the risk of asthma symptoms and respiratory tract infections throughout childhood.
Background
Television (TV) viewing and computer use have been associated with higher risk of depression, but studies specifically assessing the impact of these and other types of sedentary behaviors ...(SBs) on the mental health of older adults are scarce and their results are inconclusive. Similarly, the association between specific types of recreational physical activity (rPA) and mental health in older adults is poorly understood.
Methods
In 2012, information on SBs, rPA, and other health behaviors was collected with validated questionnaires from community‐dwelling older adults participating in the Seniors‐ENRICA cohort. In 2012 and 2015, symptoms of depression and mental distress were assessed using the GDS‐10 and the General Health Questionnaire‐12 (GHQ‐12), respectively.
Results
Time spent watching TV was prospectively associated with higher (worse) GDS‐10 scores in women (β 95% confidence interval (CI) comparing the second and third tertiles of TV viewing to the first: 0.21 –0.04 to 0.46 and 0.37 0.13–0.62, respectively; P‐trend: < 0.01), but not in men (−0.11 –0.35 to 0.13 and –0.18 –0.44 to 0.08; P‐trend: 0.16). Women, but not men, who spent more time in other SBs, including reading, using the computer and commuting, showed a lower number of depressive symptoms (−0.19 –0.44 to 0.06 and –0.34 –0.60 to –0.08; P‐trend: 0.01) and lower (better) GHQ‐12 scores (−0.33 –0.67 to –0.00 and –0.35 –0.69 to –0.00; P‐trend: 0.05) at follow‐up. Both in men and women, higher levels of rPA, such as walking, practicing sports, and do‐it‐yourself activities, were associated with lower GDS‐10 scores (−0.07 –0.25 to 0.11 and –0.19 –0.36 to –0.01; P‐trend: 0.04) and with lower GHQ‐12 scores (−0.02 –0.26 to 0.22 and –0.23 –0.47 to –0.00; P‐trend: 0.06).
Conclusions
Older women who spent more time watching TV and less time in other SBs showed a higher number of depressive symptoms. Data suggest that increasing rPA may improve mental health in older adults, particularly among women.
Evidence is growing for the beneficial impacts of natural outdoor environments on health. However, most of the evidence has focused on green spaces and little evidence is available on health benefits ...of blue spaces and about possible mediators and modifiers of such impacts. We investigated the association between natural outdoor environments (separately for green and blue spaces) and health (general and mental) and its possible mediators and modifiers.
Cross-sectional data from adults interviewed in Catalonia (Spain) between 2010 and 2012 as part of the Catalonia Health Survey were used. The collected data included sociodemographic characteristics, self-perceived general health, mental health, physical activity and social support. Indicators of surrounding greenness and access to natural outdoor environments within 300m of the residence and degree of urbanization were derived for residential addresses. Associations were estimated using logistic regression and negative binominal models.
Green spaces were associated with better self-perceived general health and better mental health, independent of degree of urbanization. The associations were more consistent for surrounding greenness than for access to green spaces. The results were consistent for different buffers, and when stratifying for socioeconomic status. Slightly stronger associations were found for women and residents of non-densely populated areas. No association was found between green spaces and social contacts and physical activity. The results for blue spaces were not conclusive.
Green spaces are associated with better general and mental health across strata of urbanization, socioeconomic status, and genders. Mechanisms other than physical activity or social support may explain these associations.
•Little evidence on modificators and mediators of benefits of green and blue spaces•Exposure to green spaces was associated with better general and mental health.•Such benefits were independent of urbanization, gender and socioeconomic status.•Underlying mechanisms were theorized to not be physical activity or social support.•No consistent results were found on blue spaces.
The COVID-19 pandemic has shed light on the norms, patterns, and power structures in the United States that privilege certain groups of people over others. This article describes COVID-19 as an ...unprecedented catalyst for social transformation that underscores the need for multilevel and cross-sectoral solutions to address systemic changes to improve health equity for all. The authors propose that the American Psychological Association (APA) and its membership can initiate systemic change, in part, by (a) supporting mutual aid organizations that prioritize the needs of vulnerable communities; (b) leveraging the efforts and strides APA psychologists have already made within the association, in the profession, and in policymaking to attend to the health equity and the needs of marginalized communities; (c) building capacity for collaboration between a broad coalition of health associations, health experts, and policymakers to address the physio-psycho-socioeconomic needs of disadvantaged communities; and (d) increasing the APA's participation in the formulation and implementation of an advocacy agenda that prioritizes the physical and psychological health of the communities whose lives are most endangered by COVID-19.
Public Significance Statement
Our article aimed to emphasize the important role that social determinants of health play for marginalized communities. It has the potential to inform health professionals, including psychologists, about support and advocacy strategies that seek to improve health equity during the COVID-19 pandemic and after it is contained.
This paper presents the empirical evaluation of the path-tracking accuracy of a three-wheeled omnidirectional mobile robot that is able to move in any direction while simultaneously changing its ...orientation. The mobile robot assessed in this paper includes a precise onboard LIDAR for obstacle avoidance, self-location and map creation, path-planning and path-tracking. This mobile robot has been used to develop several assistive services, but the accuracy of its path-tracking system has not been specifically evaluated until now. To this end, this paper describes the kinematics and path-planning procedure implemented in the mobile robot and empirically evaluates the accuracy of its path-tracking system that corrects the trajectory. In this paper, the information gathered by the LIDAR is registered to obtain the ground truth trajectory of the mobile robot in order to estimate the path-tracking accuracy of each experiment conducted. Circular and eight-shaped trajectories were assessed with different translational velocities. In general, the accuracy obtained in circular trajectories is within a short range, but the accuracy obtained in eight-shaped trajectories worsens as the velocity increases. In the case of the mobile robot moving at its nominal translational velocity, 0.3 m/s, the root mean square (RMS) displacement error was 0.032 m for the circular trajectory and 0.039 m for the eight-shaped trajectory; the absolute maximum displacement errors were 0.077 m and 0.088 m, with RMS errors in the angular orientation of 6.27° and 7.76°, respectively. Moreover, the external visual perception generated by these error levels is that the trajectory of the mobile robot is smooth, with a constant velocity and without perceiving trajectory corrections.
The aim of this study was to understand the impact of vacuum gas oil (VGO) properties on the deactivation rate of a hydrocracking catalyst (nickel–molybdenum sulfide dispersed on a carrier containing ...USY zeolite). For this purpose, two hydrotreated feeds of different densities, organic nitrogen (∼120–150 ppmw) and aromatic content, were hydrocracked under operating conditions that favor catalyst deactivation, that is, high temperature (T = 418 °C) and high space velocity (LHSV = 3 h–1). The catalyst performance was followed by measuring the VGO conversion (370 °C+ petroleum cut) and determining the apparent kinetic constants for the main hydrocracking reactions (cracking, hydrodenitrogenation, hydrodesulfurization, and aromatics hydrogenation). The experiments were stopped after different times on stream (either 6 or 30 days) in order to assess the evolution of the catalyst as a function of time. The spent catalysts, obtained from three different reactor locations, were characterized by elemental and textural analyses and by thermogravimetry to investigate the quantity and nature of the coke formed. Catalytic tests with different model compounds (toluene and n-heptane) were carried out to determine the residual activity of the hydrogenating and acid catalyst functions. It was found that, at the evaluated conditions, both the nature and the content of organic nitrogen and aromatics compounds of the feedstock have a determinant role in the deactivation rate. Organic nitrogen determines the ratio between available metal and acid sites. The aromatics generate coke precursors on the available acid sites. Both factors play a coupled role that promotes coke deposition on the catalyst surface, which leads to an increase in the deactivation rate on top of the end boiling point of the feed.
A number of studies have associated natural outdoor environments with reduced mortality but there is no systematic review synthesizing the evidence.
We aimed to systematically review the available ...evidence on the association between long-term exposure to residential green and blue spaces and mortality in adults, and make recommendations for further research. As a secondary aim, we also conducted meta-analyses to explore the magnitude of and heterogeneity in the risk estimates.
Following the PRISMA statement guidelines for reporting systematic reviews and meta-analysis, two independent reviewers searched studies using keywords related to natural outdoor environments and mortality.
Our review identified twelve eligible studies conducted in North America, Europe, and Oceania with study populations ranging from 1645 up to more than 43 million individuals. These studies are heterogeneous in design, study population, green space assessment and covariate data. We found that the majority of studies show a reduction of the risk of cardiovascular disease (CVD) mortality in areas with higher residential greenness. Evidence of a reduction of all-cause mortality is more limited, and no benefits of residential greenness on lung cancer mortality are observed. There were no studies on blue spaces.
This review supports the hypothesis that living in areas with higher amounts of green spaces reduces mortality, mainly CVD. Further studies such as cohort studies with more and better covariate data, improved green space assessment and accounting well for socioeconomic status are needed to provide further and more complete evidence, as well as studies evaluating the benefits of blue spaces.
•We reviewed the evidence on the association between residential green spaces and mortality.•Studies are heterogeneous in design, study population and green space assessment.•Most of the studies show a reduction of the risk of cardiovascular disease mortality.•Evidence of a reduction of all-cause mortality is more limited.•No benefits of residential greenness on lung cancer mortality are observed.
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