Carbon export from mangrove forests to the oceans partly acts as a sink for atmospheric CO2, exceeding the rate of carbon burial in mangrove soils. Primary production in ecosystems adjacent to mangroves may prevent degassing and enhance further carbon export from mangroves to the oceans. In this study, we continuously monitored carbonate chemistry parameters (pCO2, dissolved inorganic carbon (DIC), total alkalinity (TA)) and dissolved organic carbon (DOC) in a tidal flat adjacent to a fringe mangrove forest over a spring-neap tidal cycle. Mean pCO2 during the entire period was 923 ± 318 μatm, and the export of TA, DIC, and DOC from the mangroves to the ocean was 36 ± 26 mmol m−2 d−1, 42 ± 39 mmol m−2 d−1, and 10 ± 9 mmol m−2 d−1, respectively. Semi-monthly pCO2 variations in the mangrove front were controlled by the tidal level during spring tide and by photosynthesis and respiration on the tidal flat during neap tide. This means that during neap tide, photosynthesis on the tidal flat offset the increase in pCO2 caused by the porewater export from the mangrove soil. The DIC/TA export ratio in this study was 1.17 ± 0.08, which was lower than the global average of 1.41 ± 1.39, indicating that the tidal flat adjacent to the mangrove forest may act as a buffer zone to mitigate the increase in pCO2, resulting in much of the exported DIC being stored in the ocean.

Abstract Turnpike results hold a central position in the area of applied mathematics, offering profound insights into the long-term behavior of optimal control systems. They play an important role in guiding decision-making processes in dynamic systems. Often dynamic systems depend on uncertain data and/or parameters. In this paper, optimal boundary control problems for the transport equation with random initial data and random source term are considered. The paper commences with a presentation of a novel direct proof for a integral turnpike result for the optimal control and the corresponding optimal state in the deterministic setting, that does not require any restrictions on the source term of the transport equation. Further the analysis is extended to the stochastic setting, where the initial data is perturbed by a Wiener process and the source term is multiplied with a random variable. Integral turnpike results for the optimal controls and the corresponding expected optimal states are presented for this setting as well and the turnpike constant is further specified for Gaussian and uniformly distributed random variables.

In Japan, when a beneficiary receives benefits from a benefactor, it is not unusual for the beneficiary to use apologies to express gratitude. However, literature has not fully investigated how received gratitude and apologies impact Japanese benefactors’ perceptions. This experimental study examined how received gratitude and apologies influenced 671 Japanese participants’ (benefactors) negative and positive face as well as their self-efficacy. The results showed that the participants who received a message with gratitude or both gratitude and apologies perceived that their negative and positive face were less threatened than those in a control condition. Contrary to literature, those who received gratitude did not have high levels of self-efficacy. However, their self-efficacy was high after they received apologies only when they put more effort into helping a beneficiary. This study revealed unique roles of gratitude and apologies in meeting various psychological needs of Japanese.

This study investigates the optimal and non-optimal parameter values of the MACD (Moving Average Convergence Divergence) technical analysis indicator for three major stock market index futures: the Nikkei 225, the Dow Jones, and the Nasdaq. Using a recently developed methodology, it reveals the existence of specific ranges of optimal and non-optimal values for each of the three parameters of the MACD indicator in these indices. Sample models employing the optimal parameter values in the three index futures generated significantly higher returns, outperforming both a non-technical buy-and-hold strategy and a random strategy that did not incorporate any market information. This discovery suggests that the three market indices may not be weak-form efficient. Therefore, this study contributes to the research on market efficiency by verifying inefficiency using a new approach. The highlight of this study is identifying that the ranges of optimal parameter values for the three indices are different from each other, but the optimal parameter value combinations for each of the three indices share a unique characteristic form. This issue and its finding have not been explored in the existing literature. Several interesting findings and valuable insights for market participants and researchers arise from this study. The new methodology is unique in finding optimal and non-optimal parameter values through the analysis of parameter sets used in well-performing and poorly performing sample models. Its validity and reliability have been confirmed by this study, making a useful contribution to the field of technical analysis research, particularly in parameter optimization insight.

AbstractThis paper examines whether and how heterogeneity within necessity- and opportunity-based entrepreneur groups affects business performance using a survey of 21,532 new firms in Japan. The major findings are as follows. First, business performance is not homogeneous among either necessity- or opportunity-based entrepreneurs. Second, the existing theory that necessity-based entrepreneurs tend to show poorer performance than opportunity-based entrepreneurs does not necessarily hold when considering heterogeneity within the groups. Specifically, among some types of necessity- and opportunity-based entrepreneurs, necessity-based entrepreneurs can even exhibit better performance than opportunity-based entrepreneurs.

This study empirically investigates the major factors determining user satisfaction with counter services at local government offices in Japan. Data were collected via on-site surveys on user satisfaction with the local government office counter services using an original three-category questionnaire scale tailored to fit local administration characteristics in Japan. A total of 1000 questionnaires were distributed at the city hall during August 23–26, 2021; a total of 537 valid responses were received (response rate: 53.7%). Regression analysis indicated that the independent variables of category C (service delivery) were the most influential, followed by the B (human-related factors) and A (office hardware) categories (adjusted R2 value: 0.58). Results showed that the human factor is a key factor in counter service in terms of user satisfaction. The human factor was found to be a statistically significant explanatory variable in two on-site surveys at Higashihiroshima City and Internet surveys of ward office users in Osaka City and the Tokyo Metropolitan Area. These findings align with the conclusions of implementation research, which first emerged in the 1970s. For instance, street-level bureaucracy research has highlighted the importance of frontline administrative officials. For service delivery (C), identified as the most important factor, promptness of service delivery and a short waiting time do not necessarily affect user satisfaction positively. Moreover, this study identified two important factors for the counter-staff responses and human-related factors category: (1) speed with which the attending counter clerk speaks and (2) atmosphere and kindness of the attending counter clerk.

Prolonged and active old age provides individuals with more chances to work again after full retirement. Returning to work is an increasingly common form of the retirement process and influences the sustainability of social security systems. Previous studies show a beneficial relationship between returning to work and health; however, little is known about the causal effect of returning to work on health. This study used data from men and women aged 50 and older (11,991 individuals) in the Longitudinal Survey of Middle-aged and Older Adults, conducted annually from 2005 to 2019 in Japan. The effects of three types of labor force transitions (continued work, full retirement, and return to work) on physical and mental health were examined. To obtain the causal effects, an instrumental variable approach was used by exploiting the Japanese pension reform and labor market settings as instruments. Compared with full retirement, returning to work showed significantly worse mental health but no significant difference in physical health. The negative effect of returning to work was pronounced among men, former nonmanual workers, and low-wealth individuals. Contrary to the findings in previous studies, insignificant or detrimental effects of returning to work were found in this study. The rigorous causal analysis adds new evidence to the literature. The findings provide important implications for labor and health policy in aging societies.

The present study examines the 3-dimensional data of human crania from the Yayoi period (800 BC to AD 250) of the Japanese archipelago by geometric morphometrics to investigate demic diffusion patterns. This is the first study on the Yayoi crania using their 3D data and geometric morphometrics with a much larger number of skeletal remains outside of the Kyushu regions than previous studies. The comparative results between the Jōmon and Yayoi samples show that the Yayoi people not only in the eastern parts but also in the western parts of the archipelago are significantly different from the final Jōmon people and the Yayoi people were not strongly affected by the Jōmon people. A relatively gradual geological cline is also found among the Yayoi population, suggesting that the immigrants from the continental East Asia moved from the western parts to the eastern parts of the archipelago though the causes of the morphological changes are unclear.