AI, ageing and brain-work productivity: Technological change in professional Japanese chess.

Using Japanese professional chess (Shogi) players' records in the setting where various external factors are controlled in deterministic and finite games, this paper examines how and the extent to which the emergence of technological changes influences the ageing and innate ability of players' winning probability. We gathered games of professional Shogi players from 1968 to 2019, which we divided into three periods: 1968-1989, 1990-2012 (the diffusion of as information and communications technology (ICT)) and 2013-2019 (artificial intelligence (AI)). We found (1) diffusion of AI reduces the impact of innate ability in players performance. Consequently, the performance gap among same-age players has narrowed; (2) in all the periods, players' winning rates declined consistently from 20 years and as they get older; (3) AI accelerated the ageing decline of the probability of winning, which increased the performance gap among different aged players; (4) the effects of AI on the ageing decline and the probability of winning are observed for high innate skill players but not for low innate skill ones. The findings are specific to Shogi as a kind of board games although it is valuable to examine the extent to which the findings hold for other labor market.

Surname order and revaccination intentions during the COVID-19 pandemic.

Teachers in Japanese schools employ alphabetical surname lists that call students sooner, with surnames appearing early on these lists. We conducted Internet surveys nearly every month from March 2020 to September 2022 with the same participants, wherein we asked participants where the alphabetical columns of their childhood and adult surnames were located. We aimed to identify how surname order is important for the formation of noncognitive skills. During the data collection period, the COVID-19 vaccines became available; Japanese people could receive their third dose starting in December 2021. The 19th wave of the survey was conducted in January 2022. Therefore, to examine how a surname's alphabetical order could influence intention to revaccinate, we used a subsample of data from December 2021 to September 2022. The major findings were as follows. Women with early surnames had an approximately 4% stronger likelihood of having such intentions than men with early surnames. Early name order was more strongly correlated with revaccination intention among women than among men. The surname effect for women was larger when a mixed-gender list was used compared with when it was not used. This effect was only observed for childhood surnames and not for adult surnames.

Association between the COVID-19 Vaccine and Preventive Behaviors: Panel Data Analysis from Japan.

The coronavirus (COVID-19) vaccine is key to reducing the probability of contracting COVID-19. The vaccine is generally known to prevent severe illness, death, and hospitalization as a result of the disease and for considerably reduce COVID-19 infection risk. Accordingly, this might significantly change an individual's perceived risk of altering everyday behaviors. For instance, the proliferation of vaccination is anticipated to reduce preventive behaviors such as staying at home, handwashing, and wearing a mask. We corresponded with the same individuals monthly for 18 months from March 2020 (early stage of COVID-19) to September 2021 in Japan to independently construct large sample panel data (N = 54,007), with a participation rate of 54.7%. We used a fixed effects model, controlling for key confounders, to determine whether vaccination was associated with a change in preventive behaviors. The major findings are as follows. Contrary to the prediction, (1) based on the whole sample, being vaccinated against COVID-19 led people to stay at home; however, it did not change the habit of handwashing and wearing a mask. Especially after the second shot, respondents were likelier to stay at home by 0.107 (95% CIs: 0.059-0.154) points on a 5-point scale compared to before the vaccination. Dividing the entire sample into young and old, (2) those aged ≤ 40 years were more likely to go out after being vaccinated, and (3) people over 40 years of age were more likely to stay at home (similar to the first result). Preventive behaviors impact all individuals during the current pandemic. Informal social norms motivate people to increase or maintain preventive behaviors even after being vaccinated in societies where these behaviors are not enforced.

Gender Differences of the Effect of Vaccination on Perceptions of COVID-19 and Mental Health in Japan.

Vaccination has been promoted to mitigate the spread of the coronavirus disease 2019 (COVID-19). Vaccination is expected to reduce the probability of and alleviate the seriousness of COVID-19 infection. Accordingly, this might significantly change an individual's subjective well-being and mental health. We observed the same individuals on a monthly basis from March 2020 to September 2021 in all parts of Japan. Then, large sample panel data (N = 54,007) were independently constructed. Using the data, we compared the individuals' perceptions of COVID-19, subjective well-being, and mental health before and after vaccination. Furthermore, we compared the effect of vaccination on the perceptions of COVID-19 and mental health for females and males. We used the fixed-effects model to control for individual time-invariant characteristics. The major findings were as follows: First, the vaccinated people perceived the probability of getting infected and the seriousness of COVID-19 to be lower than before vaccination. This was observed not only when we used the whole sample but also when we used subsamples of males and a subsample of females. Second, subjective well-being and mental health improved. The same results were also observed using the subsample of females, whereas the improvements were not observed when using a subsample of males. This implies that females' quality of life was more likely to be improved by vaccination than males' one. The novelty of the work is to show the gender difference in the vaccination effects.

How does the impact of the COVID-19 state of emergency change? An analysis of preventive behaviors and mental health using panel data in Japan.

This study applies the difference-in-difference method on panel data collected from internet surveys to investigate changes in the preventive behaviors and mental health of individuals as influenced by the COVID-19 state of emergency declaration between March and June 2020. The key findings are: (1) The declaration led people to exhibit preventive behaviors but also generated negative emotions; (2) Such behaviors persisted even after deregulation of the state of emergency; (3) Making the declaration early (vs. late) had a larger effect on preventive behavior, with the gap between residents' behaviors for areas that made early vs. late declarations persisting after the deregulation; and (4) The effects on mental health diminished during the state of emergency and disappeared after its deregulation.

Racers' attractive looks, popularity, and performance: how do speedboat racers react to fans' expectations?

Using a large sample of individual-level records in Japan speedboat racing where men and women racers participate, we investigated how racers' performance meets fans' pre-race expectations. To control for endogeneity bias, we measured the order of racers' attractiveness randomly determined in each race and then used this order as instrument for measuring racers' popularity. The fixed-effects IV estimations revealed the following. (1) Racers who are more attractive than their competitors tend to be more popular even after controlling for the condition of the race, racer ability, and other characteristics. (2) More popular men show better performance in the race even if the reward does not vary according to popularity; such tendency is not observed for women. This study contributes a novel setting for determining the expectation-enhancing effects of physical attractiveness.

The Willingness to Pay for a Hypothetical Vaccine for the Coronavirus Disease 2019 (COVID-19).

This study investigates how people in Japan perceived the severity of and probability of infection from coronavirus disease 2019 (COVID-19), and how their willingness to purchase a hypothetical vaccine depends on these perceptions and their risk attitudes. We conducted a large-scale panel survey three times between 13 March to 13 April 2020 in Japan. By analyzing the data, we found that the perception of COVID-19 became more serious. The estimation of the fixed effect model reveals that a person becomes more willing to pay for a vaccine as the person evaluates COVID-19 as a more severe disease, considers a higher probability of infection, and becomes more risk averse. Since the sensitivity of willingness to pay for the vaccine on risk aversion increased during the period, the change in risk attitude contributed to an increase in willingness through the sensitivity channel, while it decreased through the magnitude channel.

Bacterial mutagenicity test data: collection by the task force of the Japan pharmaceutical manufacturers association.

BACKGROUND: Ames test is used worldwide for detecting the bacterial mutagenicity of chemicals. In silico analyses of bacterial mutagenicity have recently gained acceptance by regulatory agencies; however, current in silico models for prediction remain to be improved. The Japan Pharmaceutical Manufacturers Association (JPMA) organized a task force in 2017 in which eight Japanese pharmaceutical companies had participated. The purpose of this task force was to disclose a piece of pharmaceutical companies' proprietary Ames test data. RESULTS: Ames test data for 99 chemicals of various chemical classes were collected for disclosure in this study. These chemicals are related to the manufacturing process of pharmaceutical drugs, including reagents, synthetic intermediates, and drug substances. The structure-activity (mutagenicity) relationships are discussed in relation to structural alerts for each chemical class. In addition, in silico analyses of these chemicals were conducted using a knowledge-based model of Derek Nexus (Derek) and a statistics-based model (GT1_BMUT module) of CASE Ultra. To calculate the effectiveness of these models, 89 chemicals for Derek and 54 chemicals for CASE Ultra were selected; major exclusions were the salt form of four chemicals that were tested both in the salt and free forms for both models, and 35 chemicals called "known" positives or negatives for CASE Ultra. For Derek, the sensitivity, specificity, and accuracy were 65% (15/23), 71% (47/66), and 70% (62/89), respectively. The sensitivity, specificity, and accuracy were 50% (6/12), 60% (25/42), and 57% (31/54) for CASE Ultra, respectively. The ratio of overall disagreement between the CASE Ultra "known" positives/negatives and the actual test results was 11% (4/35). In this study, 19 out of 28 mutagens (68%) were detected with TA100 and/or TA98, and 9 out of 28 mutagens (32%) were detected with either TA1535, TA1537, WP2uvrA, or their combination. CONCLUSION: The Ames test data presented here will help avoid duplicated Ames testing in some cases, support duplicate testing in other cases, improve in silico models, and enhance our understanding of the mechanisms of mutagenesis.

Covering Soybean Leaves With Cellulose Nanofiber Changes Leaf Surface Hydrophobicity and Confers Resistance Against Phakopsora pachyrhizi.

Asian soybean rust (ASR) caused by Phakopsora pachyrhizi, an obligate biotrophic fungal pathogen, is the most devastating soybean production disease worldwide. Currently, timely fungicide application is the only means to control ASR in the field. We investigated cellulose nanofiber (CNF) application on ASR disease management. CNF-treated leaves showed reduced lesion number after P. pachyrhizi inoculation compared to control leaves, indicating that covering soybean leaves with CNF confers P. pachyrhizi resistance. We also demonstrated that formation of P. pachyrhizi appressoria, and also gene expression related to these formations, such as chitin synthases (CHSs), were significantly suppressed in CNF-treated soybean leaves compared to control leaves. Moreover, contact angle measurement revealed that CNF converts soybean leaf surface properties from hydrophobic to hydrophilic. These results suggest that CNF can change soybean leaf surface hydrophobicity, conferring resistance against P. pachyrhizi, based on the reduced expression of CHSs, as well as reduced formation of pre-infection structures. This is the first study to investigate CNF application to control field disease.

School closures and mental health during the COVID-19 pandemic in Japan.

The spread of the novel coronavirus disease caused schools in Japan to close to cope with the pandemic. In response to the school closures, parents of students were obliged to care for their children during the daytime, when children usually were at school. Did the increase in the burden of childcare influence parents' mental health? Based on short panel data from mid-March to mid-April 2020, we explore how school closures influenced the mental health of parents with school-aged children. Using a fixed-effects model, we find that school closures led to mothers of students suffering from worse mental health compared to other females, while the fathers' mental health did not differ from that of other males. This tendency is only observed for less-educated mothers who had children attending primary school, not for those with children attending junior high school nor for more-educated mothers. The contribution of this paper is showing that school closures increased the inequality of mental health between genders and parents with different educational backgrounds.

Correction to: The impact of closing schools on working from home during the COVID-19 pandemic: evidence using panel data from Japan.

[This corrects the article DOI: 10.1007/s11150-020-09536-5.].

The impact of closing schools on working from home during the COVID-19 pandemic: evidence using panel data from Japan.

COVID-19 has led to the closure of various schools in Japan to cope with the pandemic. This study explores how school closure influences parents' work style based on short panel data for the period of school closure from mid-March to mid-April 2020. Specifically, we analyze how the presence of their children influences parents' work at home and examine how the effect differs by the parent's gender. After controlling for various factors, we find that in cases where parents are full-time employees and the children are: (1) in primary school, mothers are more likely to work remotely, while fathers are less likely to do so and (2) in junior high school, the parents' work styles are hardly affected. This shows that mothers shoulder the burden of working remotely and caring for small children at home, while fathers tend to work in the office and spend less time with their childcare at home. Inevitably, COVID-19 has increased the inequality in the burden of child care.

Feasibility and Safety of Intravascular Temperature Management for Severe Heat Stroke: A Prospective Multicenter Pilot Study.

OBJECTIVES: Heat stroke is a life-threatening condition with high mortality and morbidity. Although several cooling methods have been reported, the feasibility and safety of treating heat stroke using intravascular temperature management are unclear. This study evaluated the efficacies of conventional treatment with or without intravascular temperature management for severe heat stroke. DESIGN: Prospective multicenter study. SETTING: Critical care and emergency medical centers at 10 tertiary hospitals. PATIENTS: Patients with severe heat stroke hospitalized during two summers. INTERVENTIONS: Conventional cooling with or without intravascular temperature management. MEASUREMENTS AND MAIN RESULTS: Cooling efficacy, Sequential Organ Failure Assessment score, occurrence rate of serious adverse events, and prognosis based on the modified Rankin Scale and Cerebral Performance Category. Patient outcomes were compared between five centers that were prospectively assigned to perform conventional cooling (control group: eight patients) and five centers that were assigned to perform conventional cooling plus intravascular temperature management (intravascular temperature management group: 13 patients), based on equipment availability. Despite their higher initial temperatures, all patients in the intravascular temperature management group reached the target temperature of 37°C within 24 hours, although only 50% of the patients in the control group reached 37°C (p < 0.01). The intravascular temperature management group also had a significant decrease in the Sequential Organ Failure Assessment score during the first 24 hours after admission (4.0 vs 1.5; p = 0.04). Furthermore, the intravascular temperature management group experienced fewer serious adverse events during their hospitalization, compared with the control group. The percentages of favorable outcomes at discharge and 30 days after admission were not statistically significant. CONCLUSIONS: The combination of intravascular temperature management and conventional cooling was safe and feasible for treating severe heat stroke. The results indicate that better temperature management may help prevent organ failure. A large randomized controlled trial is needed to validate our findings.

Correlation between the results of in vitro and in vivo chromosomal damage tests in consideration of exposure levels of test chemicals.

INTRODUCTION: We examined the correlation between the results of in vitro and in vivo chromosomal damage tests by using in-house data of 18 pharmaceutical candidates that showed positive results in the in vitro chromosomal aberration or micronucleus test using CHL/IU cells, and quantitatively analyzed them especially in regard to exposure levels of the compounds. FINDINGS: Eight compounds showed that the exposure levels [maximum plasma concentration (Cmax) and AUC0-24h] were comparable with or higher than the in vitro exposure levels [the lowest effective (positive) concentration (LEC) and AUCvitro = LEC (µg/mL) × treatment time (h)]. Among them, 3 compounds were positive in the in vivo rodent micronucleus assays using bone marrow cells. For 2 compounds, cytotoxicity might produce false-positive results in the in vitro tests. One compound showed in vitro positive results only in the condition with S9 mix which indicated sufficient concentration of unidentified active metabolite(s) might not reach the bone marrow to induce micronuclei. CONCLUSION: These facts suggested that the in vivo exposure levels being equal to or higher than the in vitro exposure levels might be an important factor to detect in vivo chromosomal damage induced by test chemicals.

Comparing the role of the height of men and women in the marriage market.

This paper explores how the role of men and women's height in the marriage market has changed across generations. Using individual-level data from Japan, we compared the effect of height on marriages between men and women, and investigated how the effect of height on marriage has changed across generations. Our key findings are: (1) for men born before 1965, a 1% increase in height led to an approximately 0.56% increase in the probability of being married. Conversely, for women born before 1965, a 1% increase in height led to an approximately 0.56% decrease in the probability of being married. (2) For men born in or after 1965, a 1% increase in height led to an approximately 1.05% (0.18%) increase (decrease) in the probability of being married (divorced). However, the height effect was not present for women. Japan experienced astounding economic development after World War II, which resulted in changes in its economic and social structure. These changes may have also altered the role of height for Japanese men and women in the marriage market.

Impact of the Fukushima nuclear accident on obesity of children in Japan (2008-2014).

This study used prefecture-level panel data from Japan for the period 2008-2014 to investigate the influence of the 2011 Fukushima nuclear accident on the body mass index (BMI) z-score and obesity rates of children over time. I adopted a difference-in-differences approach and found the following: (1) for the cohort aged 5-7 years in 2010, the BMI z-score and obesity rates in disaster-affected areas were higher than in other areas, although this was not observed for the other cohorts; (2) for the cohort aged 5-7 years in 2010, the influence of the accident persisted even after 3 years; and (3) the differences in the BMI z-score and obesity rate before and after the accident were greater for Fukushima Prefecture than for the other affected areas (Iwate and Miyagi prefectures). I infer that health-conscious parents, whose children had lower BMIs, may have moved from Fukushima, thereby increasing the BMI z-score of the child population living in Fukushima by around 0.05 for the cohort aged 5-7 years. The enforced reduction in physical activity increased the BMI z-score of children living in Fukushima by around 0.19 for that cohort.

A case of suicide by helium gas.

Helium is a colorless, tasteless, and odorless gas that is used as a lifting gas for air balloons and small airships due to its high level of safety. In recent years, it has become easy to search the Internet for methods to commit suicide, and the use of helium gas for this purpose has recently been garnering attention. We report a case of a male in his 30's in which helium gas was used to commit suicide. He was found unconscious on a bed with a plastic bag covering his head. When emergency personnel arrived at the scene, he was in cardiac arrest and remained in cardiac arrest at the time of his arrival at the hospital. Continued cardiopulmonary resuscitation resulted in a return of spontaneous circulation. Head computed tomography showed the corticomedullary border was indistinct. Fifteen hours at the hospital, the patient died. Recently, there has been an increasing trend for suicide being performed according to methods obtained through the Internet or mass media. Although there are only a few cases of suicide by helium gas in Japan, attention must be paid to this issue as the number of such cases may increase in the future.

Decomposing the effect of height on income in China: The role of market and political channels.

It is well known that height is positively associated with earnings. Based on individual level data, this paper investigates the channels through which height influences income in China. Our first key finding is that for males (females) a 1 centimeter (cm) increase in height leads to a 0.5% (0.02%) increase in the probability that he (she) becomes a Communist Party member. Further, the hourly wage of Communist Party members is approximately 11% higher than non-members for males, while no difference in the hourly wage between Party members and non-members is observed for females. Therefore, a 1cm increase in height leads to approximately a 0.06% increase in the hourly wage, which is observed only for males. We label this the height premium in earnings through the political channel. Second, controlling for the political channel of the height premium, a 1cm increase in height leads to a 1.18% (1.04%) increase in the hourly wage for males (females). We label this the height premium through the market channel. Together, these results suggest that the height premium in earnings through the market channel is much larger than that through the political channel.

Comparison of Social Trust's effect on suicide ideation between urban and non-urban areas: The Case of Japanese Adults in 2006.

An increasing number of studies have addressed the determinants of suicide. Social capital is a key factor in preventing suicide. However, little is known about the experience of suicide ideation using subjective values. From the viewpoint of suicide prevention, it is worth examining how people think of suicide. This paper attempts to examine the effect of social capital on suicide ideation. Furthermore, the paper compares the effect of social capital between urban and non-urban areas. In this paper, urban areas are equivalent to mega-cities with populations over one million. Non-urban areas are cities with populations of less than one million, towns and villages. Individual-level data from the Japanese General Social Surveys (JGSSs) are used. The survey, which was conducted in 2006, provides information about the subjective value of suicide ideation. The survey was answered by 1413 subjects with a mean age of 54.5. Of the subjects, 49% were male. Social trust is used to measure the degree of social capital, and the outcome of interest is suicide ideation within the past 5 years. After controlling for various factors, the major findings are that both individual-level social trust and social trust accumulated in one's residential administrative district reduce the probability that one will consider suicide. After dividing the sample into urban and non-urban residents, particularized trust plays a role in deterring suicide ideation in urban areas, while generalized trust plays a role in deterring suicide ideation in non-urban areas. The effect of each type of trust depends on its scarcity in residential areas.

Chromosomal damage and micronucleus induction by MP-124, a novel poly(ADP-ribose) polymerase-1 (PARP-1) inhibitor: Evidence for a non-DNA-reactive mode of action.

MP-124, a novel poly(ADP-ribose) polymerase-1 (PARP-1) inhibitor that competes with the binding of the PARP substrate nicotinamide adenine dinucleotide (NAD), is being developed as a neuroprotective agent against acute ischemic stroke. MP-124 increased structural chromosomal aberration in CHL/IU cells, but showed negative results in the bacterial reverse mutation test, and the rat bone marrow micronucleus (MN) and the rat liver unscheduled DNA synthesis tests after the intravenous bolus injection. Thus, MP-124 did not appear to be direct-acting mutagen. Since, PARP-1 is a key enzyme in DNA repair, the effect of continuous PARP-1 inhibition by MP-124 was further examined in the rat MN test under 24-h intravenous infusion, and an increase in micronucleated immature erythrocytes (MNIE) was observed. The increase was clearly reduced by co-treatment with nicotinic acid, which resulted in increased intracellular NAD levels. This is consistent with the established activity of MP-124 as a competitive inhibitor of PARP and provides strong evidence that the DNA-damaging effect that leads to the increase in MNIE is a secondary effect of PARP-1 inhibition. This mechanism is expected to result in a threshold for the induction of MNIE by MP-124, and allows for the establishment of a safe margin of exposure for the therapeutic use of MP-124.