Image edge smoothing method for light-field displays based on joint design of optical structure and elemental images.

Image visual quality is of fundamental importance for three-dimensional (3D) light-field displays. The pixels of a light-field display are enlarged after the imaging of the light-field system, increasing the graininess of the image, which leads to a severe decline in the image edge smoothness as well as image quality. In this paper, a joint optimization method is proposed to minimize the "sawtooth edge" phenomenon of reconstructed images in light-field display systems. In the joint optimization scheme, neural networks are used to simultaneously optimize the point spread functions of the optical components and elemental images, and the optical components are designed based on the results. The simulations and experimental data show that a less grainy 3D image is achievable through the proposed joint edge smoothing method.

Aberration correction based on a pre-correction convolutional neural network for light-field displays.

Lens aberrations degrade the image quality and limit the viewing angle of light-field displays. In the present study, an approach to aberration reduction based on a pre-correction convolutional neural network (CNN) is demonstrated. The pre-correction CNN is employed to transform the elemental image array (EIA) generated by a virtual camera array into a pre-corrected EIA (PEIA). The pre-correction CNN is built and trained based on the aberrations of the lens array. The resulting PEIA, rather than the EIA, is presented on the liquid crystal display. Via the optical transformation of the lens array, higher quality 3D images are obtained. The validity of the proposed method is confirmed through simulations and optical experiments. A 70-degree viewing angle light field display with the improved image quality is demonstrated.

Health wearable devices for weight and BMI reduction in individuals with overweight/obesity and chronic comorbidities: systematic review and network meta-analysis.

OBJECTIVE: To analyse the comparative effectiveness of different health wearable-based physical activity (PA) promotion intervention strategies against each other and control for reducing body weight and body mass index (BMI) in individuals with overweight/obesity and chronic comorbidities. DESIGN: Systematic review and network meta-analysis (PROSPERO identifier: CRD42020158191). DATA SOURCES: We performed two independent searches from December 2019 to September 2020 in PubMed, MEDLINE, Scopus, Web of Science, Central Register of Controlled Trials, EMBASE and PsycINFO databases for articles published in English between 2007 and 2020. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Inclusion criteria were based on the PICOS framework. We included randomised controlled trials of health wearable-based interventions using two or more PA intervention arms/strategies and compared their effects on participants' body weight (kg) and BMI (kg/m2) with a control group. Data were analysed using a Bayesian network meta-analysis to directly and indirectly compare the effects of the six different intervention strategies (comparators). The six comparators were: (1) control group (ie, usual care, waitlist); (2) comparison group (ie, traditional, non-health wearable PA interventions); (3) commercial health wearable-only intervention (eg, Fitbit, Polar M400); (4) research grade health wearable-only intervention (ie, accelerometers or pedometers); (5) multicomponent commercial health wearable intervention (eg, Fitbit + nutrition counselling); and (6) multicomponent research grade health wearable intervention. The results were reported as standardised mean differences (SMDs) with associated 95% credible intervals (CrIs). RESULTS: From 641 screened records, 31 studies were included. For body weight reduction in individuals with overweight/obesity and chronic comorbidities, accelerometer/pedometer-only (SMD -4.44, 95% CrI -8.94 to 0.07) and commercial health wearable-only (SMD -2.76, 95% CrI -4.80 to -0.81) intervention strategies were the most effective compared with the three other treatments and control. For BMI reduction, multicomponent accelerometer/pedometer (SMD -3.43, 95% CrI -4.94 to -2.09) and commercial health wearable-only (SMD -1.99, 95% CrI -4.95 to 0.96) intervention strategies were the most effective compared with the other four conditions. CONCLUSION: Health wearable devices are effective intervention tools/strategies for reducing body weight and BMI in individuals with overweight/obesity and chronic comorbidities.

A Systematic Review of Active Video Games on Youth's Body Composition and Physical Activity.

In the past decade, active video games (AVGs) have started to find their way into communities, schools, and homes as a possible solution to promote physical activity (PA) and prevent childhood obesity. However, the evidence regarding its effectiveness on body composition and objectively measured PA in youth remains inconclusive. Thus, a systematic review on this topic is needed. This review synthesizes effects of AVGs on body composition and PA in youth. The initial search yielded 260 articles from 10 databases and 18 randomized-controlled trials were included after evaluating against eligibility and removing duplicates. Overall, AVGs showed positive effects in improving body composition and PA in overweight/obese youth as compared to the control conditions with only 2 studies displaying neutral effects on these outcomes as compared to traditional PA or comparison programs. For healthy youth, more than half of the studies (n = 10) demonstrated neutral effects of AVGs on these outcomes whereas only 6 yielded positive effects compared to the control conditions. Further, one study indicated that the control condition observed greater improvement in body composition compared with an AVG intervention in healthy youth. In summary, AVGs are deemed a promising addition to promote PA and health among overweight/obese youth with the goal of fighting childhood obesity.

Comparative Effectiveness of Physical Activity Intervention Programs on Motor Skills in Children and Adolescents: A Systematic Review and Network Meta-Analysis.

Objective: To evaluate how different physical activity (PA) interventions (traditional, exergaming, and teacher/parent education) impacted children's motor skills (object control, locomotor, and gross motor). Design: Systematic review and network meta-analysis. Data sources: PubMed, Medline, Scopus, Web of Science, EMBASE, and PsycINFO. Eligibility criteria: (1) Participants comprised 1708 children 3-12 years; (2) PA or exercise-based interventions were investigated; (3) only studies using a Test of Gross Motor Skills assessment were included; (4) RCT were chosen as the study design to assess the impact of PA interventions on children's motor skills; and (5) culture-based PA studies with English language only were included. Data were analyzed using a Bayesian network meta-analysis. Results: The results were reported as standardized mean differences (SMDs) with associated 95% credible intervals (CrIs). For object control, aerobic intervention (SMD 6.90, 95% Crl 1.39 to 13.50); for locomotor, exergaming intervention (SMD 12.50, 95% Crl 0.28 to 24.50); and for gross motor, aerobic intervention (SMD 7.49, 95% Crl 0.11 to 15.70) were the most effective treatments. Conclusion: Children's FMSs have been improved through different PA interventions. Among them, aerobic interventions seem to be the most effective intervention in enhancing object control skills and overall gross motor skills.

CuCo and sulfur doped carbon nitride composite as an effective Fenton-like catalyst in a wide pH range.

The heterogeneous Fenton-like reaction, as an advanced oxidation process, is widely recognized attributed to its recyclability, wide pH response range, easy solid-liquid separation, and non-production of iron sludge. Recently, the bimetallic catalysts have attracted intense attention due to their high catalytic performance and excellent stability over a wide pH range. In this article, CuCo/SCN bimetallic catalyst was prepared by pyrolysis method with sulfur doped carbon nitride (SCN) as the carrier. Under the conditions of pH = 7, catalyst dosage of 0.8 g/L, and concentration of H2O2 of 15 mM, 20 mg/L of methyl orange (MO) can be completely removed within 1 h. With the synergistic action between bimetals and sulfur doped carbon nitride, the CuCO/SCN involved Fenton-like system exhibited excellent catalytic degradation efficiency and strong stability for MO in neutral and weak alkaline conditions. The EPR characterization proved that OH and O2 - were the main active components. Furthermore, CuCo/SCN involved Fenton-like system has good adaptability. Bimetallic CuCo/SCN catalyst has great application potential in the degradation of environmental pollutants.

Small-Groups Versus Full-Class Exergaming on Urban Minority Adolescents' Physical Activity, Enjoyment, and Self-Efficacy.

BACKGROUND: The effects of school-based exergaming interventions on adolescents' physical activity (PA) and psychosocial outcomes have been mixed. Researchers speculate this may be attributed to design issues. Therefore, this study examined differences in urban minority adolescents' PA, enjoyment, and self-efficacy during small-groups and full-class exergaming. METHODS: Forty-seven urban minority adolescents (83% black; X¯age=11.8+1.3 y) completed two 15-minute exergaming sessions on the Xbox One Kinect Just Dance: (1) small groups (n = 3-4) and (2) full class (n = 23-24). Participants' time in sedentary behavior, light PA, and moderate to vigorous PA and steps were retrieved from ActiGraph GT3X+ accelerometers with enjoyment and self-efficacy assessed using validated surveys. RESULTS: Participants spent significantly more time in sedentary behavior (5.9 [5.2] min vs 3.5 [2.7] min, respectively: P < .001, d = 0.57) and less time in moderate-to-vigorous PA (2.1 [2.8] min vs 5.5 [2.2] min, respectively: P < .001, d = 0.85) during the full-class versus the small-groups session. Moreover, small-groups exergaming resulted in significantly higher steps than the full-class exergaming (504.2 [132.1] vs 387.8 [122.1], respectively: P = .01, d = 0.50) and significantly greater enjoyment (3.5 [1.1] vs 3.2 [1.0], respectively: P = .02, d = 0.37). There were no significant differences between sessions for time in light PA and self-efficacy. CONCLUSIONS: Small-groups exergaming appears ideal for promoting enjoyable PA at higher intensities and lower sedentary time in underserved minority adolescents.

Application of network meta-analysis in the field of physical activity and health promotion.

Continued advancement in the field of physical activity and health promotion relies heavily on the synthesis of rigorous scientific evidence. As such, systematic reviews and meta-analyses of randomized controlled trials have led to a better understanding of which intervention strategies are superior (i.e., produce the greatest effects) in physical activity-based health behavior change interventions. Indeed, standard meta-analytic approaches have allowed researchers in the field to synthesize relevant experimental evidence using pairwise procedures that produce reliable estimates of the homogeneity, magnitude, and potential biases in the observed effects. However, pairwise meta-analytic procedures are only capable to discerning differences in effects between a select intervention strategy and a select comparison or control condition. In order to maximize the impact of physical activity interventions on health-related outcomes, it is necessary to establish evidence concerning the comparative efficacy of all relevant physical activity intervention strategies. The development of network meta-analysis (NMA)-most commonly used in medical-based clinical trials-has allowed for the quantification of indirect comparisons, even in the absence of direct, head-to-head trials. Thus, it stands to reason that NMA can be applied in physical activity and health promotion research to identify the best intervention strategies. Given that this analysis technique is novel and largely unexplored in the field of physical activity and health promotion, care must be taken in its application to ensure reliable estimates and discernment of the effect sizes among interventions. Therefore, the purpose of this review is to comment on the potential application and importance of NMA in the field of physical activity and health promotion, describe how to properly and effectively apply this technique, and suggest important considerations for its appropriate application in this field. In this paper, overviews of the foundations of NMA and commonly used approaches for conducting NMA are provided, followed by assumptions related to NMA, opportunities and challenges in NMA, and a step-by-step example of developing and conducting an NMA.

The Effects of Tai Chi Intervention on Healthy Elderly by Means of Neuroimaging and EEG: A Systematic Review.

Aging is a process associated with a decline in cognitive and motor functions, which can be attributed to neurological changes in the brain. Tai Chi, a multimodal mind-body exercise, can be practiced by people across all ages. Previous research identified effects of Tai Chi practice on delaying cognitive and motor degeneration. Benefits in behavioral performance included improved fine and gross motor skills, postural control, muscle strength, and so forth. Neural plasticity remained in the aging brain implies that Tai Chi-associated benefits may not be limited to the behavioral level. Instead, neurological changes in the human brain play a significant role in corresponding to the behavioral improvement. However, previous studies mainly focused on the effects of behavioral performance, leaving neurological changes largely unknown. This systematic review summarized extant studies that used brain imaging techniques and EEG to examine the effects of Tai Chi on older adults. Eleven articles were eligible for the final review. Three neuroimaging techniques including fMRI (N = 6), EEG (N = 4), and MRI (N = 1), were employed for different study interests. Significant changes were reported on subjects' cortical thickness, functional connectivity and homogeneity of the brain, and executive network neural function after Tai Chi intervention. The findings suggested that Tai Chi intervention give rise to beneficial neurological changes in the human brain. Future research should develop valid and convincing study design by applying neuroimaging techniques to detect effects of Tai Chi intervention on the central nervous system of older adults. By integrating neuroimaging techniques into randomized controlled trials involved with Tai Chi intervention, researchers can extend the current research focus from behavioral domain to neurological level.