Electrospun Silicon Dioxide/poly(vinylidene fluoride) Nanofibrous Membrane Comprising a Skin Multicore-Shell Nanostructure as a New High-Heat-Resistant Separator for Lithium-Ion Polymer Batteries.

Porous silicon dioxide (SiO2)/poly(vinylidene fluoride) (PVdF), SiO2/PVdF, and fibrous composite membranes were prepared by electrospinning a blend solution of a SiO2 sol-gel/PVdF. The nanofibers of the SiO2/PVdF (3/7 wt. ratio) blend comprised skin and nanofibrillar structures which were obtained from the SiO2 component. The thickness of the SiO2 skin layer comprising a thin skin layer could be readily tuned depending on the weight proportions of SiO2 and PVdF. The composite membrane exhibited a low thermal shrinkage of ~3% for 2 h at 200 °C. In the prototype cell comprising the composite membrane, the alternating current impedance increased rapidly at ~225 °C, and the open-circuit voltage steeply decreased at ~170 °C, almost becoming 0 V at ~180 °C. After being exposed at temperatures of >270 °C, its three-dimensional network structure was maintained without the closure of the pore structure by a melt-down of the membrane.

Empirical Analysis of Autonomous Vehicle's LiDAR Detection Performance Degradation for Actual Road Driving in Rain and Fog.

Light detection and ranging (LiDAR) is widely used in autonomous vehicles to obtain precise 3D information about surrounding road environments. However, under bad weather conditions, such as rain, snow, and fog, LiDAR-detection performance is reduced. This effect has hardly been verified in actual road environments. In this study, tests were conducted with different precipitation levels (10, 20, 30, and 40 mm/h) and fog visibilities (50, 100, and 150 m) on actual roads. Square test objects (60 × 60 cm2) made of retroreflective film, aluminum, steel, black sheet, and plastic, commonly used in Korean road traffic signs, were investigated. Number of point clouds (NPC) and intensity (reflection value of points) were selected as LiDAR performance indicators. These indicators decreased with deteriorating weather in order of light rain (10-20 mm/h), weak fog (<150 m), intense rain (30-40 mm/h), and thick fog (≤50 m). Retroreflective film preserved at least 74% of the NPC under clear conditions with intense rain (30-40 mm/h) and thick fog (<50 m). Aluminum and steel showed non-observation for distances of 20-30 m under these conditions. ANOVA and post hoc tests suggested that these performance reductions were statistically significant. Such empirical tests should clarify the LiDAR performance degradation.

Imaging particulate matter exposed pine trees by vehicle exhaust experiment and hyperspectral analysis.

This study analyzed spectral variations of the particulate matter (PM hereafter)-exposed pine trees using a spectrometer and a hyperspectral imager to derive the most effective spectral indices to detect the pine needle exposure to PM emission. We found that the spectral variation in the near-infrared (NIR hereafter) bands systemically coincided with the variations in PM concentration, showing larger variations for the diesel group whereas larger dust particles showed spectral variations in both visible and NIR bands. It is because the PM adsorption on needles is the main source of NIR band variation, and the combination of visible and NIR spectra can detect PM absorption. Fourteen bands were selected to classify PM-exposed pine trees with an accuracy of 82% and a kappa coefficient of 0.61. Given that this index employed both visible and NIR bands, it would be able to detect PM adsorption. The findings can be transferred to real-world applications for monitoring air pollution in an urban area.

Effects of Forest Therapy on Psychological Improvement in Middle-aged Women in Korea.

OBJECTIVES: Women experience more stress in middle age than in other periods of their lives. Therefore, health management programs that enable middle-aged women to cope with and manage stress are needed. This study investigated the psychological effects of a meditation-focused forest therapy program among 53 middle-aged women living in urban areas in Korea. METHODS: Participants were divided into 2 groups: one group underwent the program for 3 days in a forest, followed by 3 days in an urban environment, and the other group underwent the program for 3 days in the urban environment, followed by 3 days in the forest. The psychological effects of the forest therapy program were evaluated using the Profile of Mood States-Brief (POMS-B). Differences in mood state before and after the program conducted in the forest (experimental group) and in the urban environment (control group) were evaluated using the paired-samples t-test. RESULTS: The program in the forest significantly reduced tension, depression, anger, fatigue, and confusion among the domains of the POMS-B. The program in the urban area significantly reduced tension, but not depression, anger, fatigue, or confusion. CONCLUSIONS: Meditation-focused forest therapy programs are expected to contribute to promoting psychological health and enhancing the quality of life of middle-aged women.

Quality of Life and Mental Health Benefits of Public Participation in Forest Conservation Activities in Urban Areas.

The purpose of this study is to investigate the effect of forest conservation activities on the physical and psychological wellbeing of participants. The experiment was conducted in a forest near an urban area and involved 61 participants (average age: 22.5 ± 1.8). The participants selected one of three activities (pruning, stacking cut branches, and removing vines) in the forest conservation program. The effects of these activities on the musculoskeletal system were assessed using the Ovako Working Posture Assessment System (OWAS); the physical intensity of the activities was evaluated using heart rate data. The psychological evaluation measurement indexes used the Positive and Negative Affect Schedule, Rosenberg Self-Esteem scale, World Health Organization Quality of Life assessment instrument, and the Perceived Restorativeness Scale. As a result of the OWAS assessment, forest conservation activities were found to be action categories 1 and 2, which were less burdensome to the musculoskeletal system. All forestry activities were found to be light levels of physical intensity. Psychological evaluation of the participants revealed that positive emotions such as self-esteem, quality of life, and perceived restorativeness increased significantly, whereas negative emotions decreased significantly. This forest conservation program, that involved low-intensity activities which were less burdensome to the musculoskeletal system, had positive physical and psychological effects on the local residents who participated.

Effect of Forest Users' Stress on Perceived Restorativeness, Forest Recreation Motivation, and Mental Well-Being during COVID-19 Pandemic.

Even though the COVID-19 pandemic has discouraged travel and people's movements, the number of visitors to forests near cities which are easily accessible by private vehicle is increasing in Korea. This study aims to investigate the relationship between stress, perceived restorativeness, forest recreation motivation, and the mental well-being of forest users. A survey of forest users was conducted at three recreational forests near Seoul in the summer of 2020. A total of 1196 forest users (613 males and 583 females) participated in the study. As a result of the data analysis, it was found that stress had a negative correlation with perceived restorativeness, forest recreation motivation, and mental well-being; perceived restorativeness had a positive correlation with mental well-being, and forest recreation motivation had a positive correlation with mental well-being. For the relationship between stress and mental well-being, the fitness index that was mediated by the perceived restorativeness and the forest recreation motivation found that the model was statistically suitable. Through this study, a research model was derived that, if the stress of forest users is reduced, direct or indirect effects on perceived restorativeness, forest recreation motivation, and mental well-being are increased. Further, a multi-group analysis found that the effect of perceived restorativeness and forest recreation motivation on the mental well-being of the male group was higher than the effect on the female group. Using this research model to find ways to promote health in forests can be utilized for forest management or forest healing.

Performance of Mobile LiDAR in Real Road Driving Conditions.

The performance of LiDAR sensors deteriorates under adverse weather conditions such as rainfall. However, few studies have empirically analyzed this phenomenon. Hence, we investigated differences in sensor data due to environmental changes (distance from objects (road signs), object material, vehicle (sensor) speed, and amount of rainfall) during LiDAR sensing of road facilities. The indicators used to verify the performance of LiDAR were numbers of point cloud (NPC) and intensity. Differences in the indicators were tested through a two-way ANOVA. First, both NPC and intensity increased with decreasing distance. Second, despite some exceptions, changes in speed did not affect the indicators. Third, the values of NPC do not differ depending on the materials and the intensity of each material followed the order aluminum > steel > plastic > wood, although exceptions were found. Fourth, with an increase in rainfall, both indicators decreased for all materials; specifically, under rainfall of 40 mm/h or more, a substantial reduction was observed. These results demonstrate that LiDAR must overcome the challenges posed by inclement weather to be applicable in the production of road facilities that improve the effectiveness of autonomous driving sensors.

Association between the Psychological Effects of Viewing Forest Landscapes and Trait Anxiety Level.

The aim of this study was to validate the psychological advantages of viewing forest landscapes. Moreover, the associations between trait anxiety levels and psychological responses were evaluated. A total of 650 university male students (age, 21.7 ± 1.6 years) viewed a scenery in a forested area and an urban area for 15 min. Furthermore, the Profile of Mood States questionnaire and State-Trait Anxiety Inventory were employed for the assessment of the psychological responses and the level of trait anxiety, respectively, of the participants. Results showed that compared with viewing a city area, viewing forest areas increased positive mood state, such as vigor, and decreased negative mood states. Furthermore, trait anxiety level and changes in the psychological responses such as depression-dejection, fatigue, and confusion after viewing forest landscapes were significantly correlated. The participants with high anxiety levels had greater reduction in negative mood state, including confusion, than those with low anxiety levels. In conclusion, viewing forest landscapes induced psychological relaxation, which was more evident in individuals with high anxiety levels.

Effects of Forest Therapy on Health Promotion among Middle-Aged Women: Focusing on Physiological Indicators.

Women experience more stress in middle age than in other life stages, and health in middle age is vital, because it influences the quality of life in old age. In this study, the effects of a forest therapy program on physiological changes in 53 middle-aged women (divided into two groups) who lived in the city were examined. One group participated in a three-day program in the forest, followed by three days in the city; the other group participated in a three-day program in the city, followed by three days in the forest. Forest experiments were conducted in a "healing forest," and urban experiments were conducted near a university campus. Blood tests were performed to evaluate the physiological effects of forest therapy. Differences in serotonin levels and vitamin D levels were verified before and after the forest (experimental group) and urban (control group) programs through paired t-tests. Statistically significant increases in serotonin levels were noted for participants in the forest program; vitamin D levels also increased, but not by statistically significant values. The findings of this study verify that forest therapy programs promote health among middle-aged women, and may prevent disease and improve quality of life.

Measures to Promote Rural Healthcare Tourism with a Scientific Evidence-Based Approach.

The present study aimed to evaluate the effects of physical activities on human health in forests in countryside and rural areas. The test experiment was conducted in a countryside forest, whereas the controlled experiment was conducted in an urban area where the study participants resided. A total of 22 participants (aged 20.9 ± 1.3 years) were evaluated in this study. Heart rate variability and salivary cortisol level were used as indices of physiological conditions, and semantic differential method, profile of mood states (POMS), and state-trait anxiety inventory (STAI) were used to evaluate the participants' emotional states. The participants were asked to walk around forest and urban areas for 15 min. The results were as follows. As compared to the urban area, in the forest area, (1) the power of the high-frequency (HF) component of the heart rate variability (HRV) was significantly higher; (2) low-frequency (LF)/(LF + HF) was significantly lower; (3) salivary cortisol level was significantly lower; (4) the participants felt more comfortable, natural, relaxed, and less anxious and showed higher levels of positive emotions and lower levels of negative emotions. Consequently, walking in the forest area induces relaxing short-term physiological and psychological effects on young people living in urban areas.

Correction: Song, C.; Ikei, H.; Park, B.J.; Lee, J.; Kagawa, T.; Miyazaki, Y. Psychological Benefits of Walking through Forest Areas. Int. J. Environ. Res. Public Health 2018, 15, 2804.

The authors wish to add the following corrections to their paper published in the International Journal of Environmental Research and Public Health [1] [...].

Correction: Lee, J. et al. Acute Effects of Exposure to a Traditional Rural Environment on Urban Dwellers: A Crossover Field Study in Terraced Farmland. Int. J. Environ. Res. Public Health 2015, 12, 1874-1893.

The authors wish to add the following corrections to their paper published in the International Journal of Environmental Research and Public Health [...].

Combined Effect of Walking and Forest Environment on Salivary Cortisol Concentration.

We investigated the effects of walking in a forest environment on salivary cortisol concentrations. Seventy-four young male participants walked for 15 min in forested and urban environments, and saliva was collected before and after walking. Our previous study reported salivary cortisol concentrations after walking only. This study was aimed at clarifying the combined effects of walking and environment by comparing post-walking data with pre-walking data. Walking in a forest environment decreased mean cortisol concentration from 9.70 to 8.37 nmol/L, whereas walking in an urban environment barely changed mean cortisol concentration, from 10.28 to 10.01 nmol/L. Two-way repeated analysis of variance revealed a significant interaction effect between the environment and walking (p < 0.001) in addition to the main effects of each (p < 0.001 and p = 0.001, for walking and environment, respectively). For further analysis, the proportion of participants who exhibited decreased cortisol after forest-walking was compared with the previously reported proportion of participants who exhibited decreased cortisol after viewing forest landscapes. Although the proportion of positive responders was slightly higher after walking (69%) than it was after viewing (60%), this difference was not statistically significant (p = 0.093). The present study revealed a significant combined effect of walking and the environment on cortisol concentrations.

Psychological Benefits of Walking through Forest Areas.

This study aimed to clarify the psychological benefits of brief walks through forest areas. In addition, we aimed to examine the associations between psychological responses and trait anxiety levels. Five-hundred-and-eighty-five participants (mean age, 21.7 ± 1.6 years) were instructed to walk predetermined courses through forest (test) and city (control) areas for 15 min. The Profile of Mood State (POMS) questionnaire and State-Trait Anxiety Inventory were used to assess participants' psychological responses and trait anxiety levels, respectively. The results revealed that walking through forest areas decreased the negative moods of "depression-dejection", "tension-anxiety", "anger-hostility", "fatigue", and "confusion" and improved the participants' positive mood of "vigor" compared with walking through city areas. Furthermore, a significant correlation was found between participants' trait anxiety levels and their changes in the subscale of "depression-dejection" of POMS after walking through forest areas. A more effective reduction in the feeling of "depression-dejection" after walking through forest areas was observed for participants with high trait anxiety levels than for those with normal and low trait anxiety levels. This study showed the psychological benefits of walking through forest areas and identified a significant correlation between psychological responses to walking through forests and trait anxiety levels.

Forest Walking Affects Autonomic Nervous Activity: A Population-Based Study.

The present study aimed to evaluate the effect of walking in forest environments on autonomic nervous activity with special reference to its distribution characteristics. Heart rate variability (HRV) of 485 male participants while walking for ~15 min in a forest and an urban area was analyzed. The experimental sites were 57 forests and 57 urban areas across Japan. Parasympathetic and sympathetic indicators [lnHF and ln(LF/HF), respectively] of HRV were calculated based on ~15-min heart rate recordings. Skewness and kurtosis of the distributions of lnHF and ln(LF/HF) were almost the same between the two environments, although the means and medians of the indicators differed significantly. Percentages of positive responders [presenting an increase in lnHF or a decrease in ln(LF/HF) in forest environments] were 65.2 and 67.0%, respectively. The percentage of lnHF was significantly smaller than our previous results on HRV during the viewing of urban or forest landscapes, whereas the percentage of ln(LF/HF) was not significantly different. The results suggest that walking in a forest environment has a different effect on autonomic nervous activity than viewing a forest landscape.

Diurnal Changes in Distribution Characteristics of Salivary Cortisol and Immunoglobulin A Concentrations.

Salivary cortisol and secretory immunoglobulin A (S-IgA) are important biomarkers for environmental and public health research. The present study investigated the diurnal variations of these salivary biomarkers, with a focus on the change of distribution characteristics (i.e., skewness and kurtosis) of the concentrations. The participants in this study were 113 healthy young males. Salivary samples were collected in the morning (6:30-7:30 a.m.) and afternoon (1:00-4:00 p.m.). The skewness and kurtosis of salivary cortisol concentrations in afternoon samples (skewness = 1.06, kurtosis = 4.78) were significantly higher than those in morning samples (skewness = 0.49, kurtosis = 2.80). The differences in skewness and kurtosis of S-IgA concentrations were non-significant; however, the standard deviation and interquartile ranges for afternoon S-IgA concentrations were significantly smaller than those for morning S-IgA concentrations. Logarithmic transformation improved the distribution of afternoon cortisol values, making it an almost normal distribution, but the transformation showed no improvement in the distribution of morning cortisol or S-IgA values. The present study explored diurnal changes in the distribution characteristics of salivary cortisol and S-IgA. Consideration of a possible diurnal change in the distribution characteristics is needed when we compare the difference in these salivary biomarkers between different times of day.

Population-Based Study on the Effect of a Forest Environment on Salivary Cortisol Concentration.

The purpose of this study was to evaluate the effect of a forest environment on salivary cortisol concentration, particularly on the characteristics of its distribution. The participants were 348 young male subjects. The experimental sites were 34 forests and 34 urban areas across Japan. The subjects viewed the landscape (forest or urban environment) for a period of 15 min while sitting in a chair. Saliva was sampled from the participants at the end of this 15-min period and then analyzed for cortisol concentration. Differences in the skewness and kurtosis of the distributions between the two environments were tested by performing a permutation test. The cortisol concentrations exhibited larger skewness (0.76) and kurtosis (3.23) in a forest environment than in an urban environment (skewness = 0.49; kurtosis = 2.47), and these differences were statistically significant. The cortisol distribution exhibited a more peaked and longer right-tailed curve in a forest environment than in an urban environment.

The Effects of a Campus Forest-Walking Program on Undergraduate and Graduate Students' Physical and Psychological Health.

We conducted a campus forest-walking program targeting university and graduate students during their lunchtime and examined the physical and psychological effects of the program. We utilized a quasi-experimental design with a control group and a pretest-posttest design. Forty-seven men (M = 25.5 ± 3.8 years) and 52 women (M = 23.3 ± 4.3 years) volunteered to participate (experimental group n = 51, control group n = 48). The intervention group participated in campus forest-walking program once a week for six weeks; they were also asked to walk once a week additionally on an individual basis. Additionally, participants received one lecture on stress management. Post-tests were conducted both just after the program ended and three months after. A chi-square test, t-test, and repeated measures analysis of variance were used to evaluate the effects of the program. Health promoting behaviors (F = 7.27, p = 0.001, ES = 0.27) and parasympathetic nerve activity (F = 3.69, p = 0.027, ES = 0.20) significantly increased and depression (F = 3.15, p = 0.045, ES = 0.18) significantly decreased in the experimental group after the intervention compared to the control group. In conclusion, using the campus walking program to target students during their lunchtime is an efficient strategy to promote their physical and psychological health.

Antinociceptive and anti-inflammatory effects of essential oil extracted from Chamaecyparis obtusa in mice.

Essential oil extracted from Chamaecyparis obtusa (EOCO) consists of several monoterpenes with anti-inflammatory effects. Monoterpenes are expected to have an analgesic effect through inhibition of pro-inflammatory mediators. The present study investigated the anti-nociceptive and anti-inflammatory effects of EOCO in animal models of pain. Intraperitoneal injection with EOCO (5 or 10mg/kg), aspirin (positive control, 300mg/kg), or DMSO (negative control) was performed 1h before the nociception tests: acetic acid-induced writhing response, formalin test, and hot plate test in mice, and acidic saline-induced allodynia in rats. The expression of pro-inflammatory cytokines and pro-inflammatory enzymes in formalin-injected paws was determined by ELISA and western blotting, respectively. Treatment with EOCO significantly reduced acetic acid-induced writhing and paw-licking time in late response of the formalin tests. The anti-nociceptive effect was comparable with aspirin. However, EOCO did not affect the reaction time of licking of the hind paws or jumping in hot plate test and the mechanical withdrawal thresholds in acidic saline-induced allodynia model. Formalin-injected paws of mice treated with EOCO revealed the down-regulated expression of tumor necrosis factor-α, interleukin-1ß, inducible nitric oxide synthase, and cyclooxygenase-2, as compared with those of control mice. These data showed the anti-nociceptive and anti-inflammatory effects of EOCO. The pain-relieving effect might be attributed to inhibition of peripheral pain in association with inflammatory response. EOCO could be a useful therapeutic strategy to manage pain and inflammatory diseases.

The Prefrontal Cortex Activity and Psychological Effects of Viewing Forest Landscapes in Autumn Season.

Recently reported research indicate that forest environments have physiological and psychological relaxing effects compared to urban environments. However, some researchers claim that the stress of the subjects from being watched by others during measurements can affect the measurement result in urban experiments conducted in the center of a street. The present study was conducted to determine whether forest environments have physiological and psychological relaxing effects, using comparison of viewing a forest area with viewing an urban area from the roof of an urban building without being watched by others. Near-infrared spectroscopy (NIRS) measurement was performed on subjects while they viewed scenery for 15 min at each experimental site (urban and forest areas). Subjective assessments were performed after the NIRS measurement was complete. Total hemoglobin and oxyhemoglobin concentrations were significantly lower in the forest area than in the urban area. For semantic differential in subjective assessments, feelings of "comfortable", "natural", and "soothed" were significantly higher in the forest area than in the urban area, and for profile of mood states, negative emotions were significantly lower in the forest area than in the urban area. The results of physiological and psychological measurements show that viewing the forest enabled effective relaxation.