Differences in adrenocortical secretory and gene expression responses to stimulation in vitro by ACTH or prolactin between high- and low-avoidance Hatano rats

Rats of the Hatano high-avoidance (HAA) and low-avoidance (LAA) strains have been genetically selected on the basis of their two-way active avoidance behavior, and have different endocrine responses to stress. The present study focused on the adrenal steroid hormone responses of the Hatano strains and identifies differences in regulation of the adrenal cortex in vitro of HAA and LAA rats. Although incubation with prolactin (PRL) and/or adrenocorticotrophic hormone (ACTH) resulted in a dose-dependent increase of corticosterone and progesterone release by adrenal cells from both HAA and LAA male rats, the responses were markedly increased for adrenal cells from LAA rats as compared with HAA rats. This finding suggested that adrenal glands of HAA rats are less sensitive to PRL and/or ACTH than adrenals from LAA rats. Several possible intra-adrenal regulators were investigated. The basal level of expression of steroidogenic acute regulatory protein (StAR) and the long form of the PRL receptor (PRLR-L) mRNAs was higher in adrenals of LAA rats. ACTH treatment of adrenal cells from HAA rats resulted in statistically significant increases in melanocortin receptor 2 (MC2R) mRNA expression, while neither ACTH nor PRL altered MC2R mRNA expression in adrenal cells of LAA rats. Conversely, the increase in PRLR-L mRNA expression induced by PRL was observed only in adrenal cells from LAA rats. Treatment of adrenal cells with PRL and/or ACTH increased the expression of StAR and CYP11A1 mRNAs for both Hatano strains. However, the induction of StAR mRNA expression was higher in LAA rats, but the CYP11A1 response was lower. These findings indicate that adrenal cells of the LAA strain have higher sensitivity to secretagogues than those of the HAA strain. These results suggest that PRL may also be important in stimulating secretion of adrenal steroid hormones.     

Contradictory Discourses on Sexual Normality and National Identity in Japanese Modernity

This paper aims to analyse the relationship between discourses of gender/sexuality and construction of national identity and normativity in Japan. Firstly, I will analyse discourses of two influential theorists of queer studies, Michel Foucault and Eve K. Sedgwick, examining how Western cultural identity and modernity have been represented through sexuality and geography in their discussion. Secondly, I will review representations of gender and sexual normality and deviances in pre-war Japan, arguing how contradictory discourses and representation of gender and sexual norms were constructed with Japanese national identity through cultural differences between Japan and the West, or Japanese tradition and Westernisation. Finally, I will examine political functions of contradictory discourses of gender/sexual normativity against sexual minorities including within contemporary ‘LGBT-friendly’ discourses in Japanese society. Through these discussions, I will point out: firstly, Japanese modern gender and sexual normativity has been sustained by contradictory discourses and confusing cultural distinctions between Japan and the West, rather than definitive transitions towards Westernisation and clear cultural distinctions between Japan and the West; secondly, how these contradictory discourses of definitions of hetero/homosexuality and differences between Japan and the West have politically functioned against sexual minorities even now. Thus, I suggest that it is more fruitful for sexuality studies in/about Japan to focus on contradictory discourses, their historical and social contexts, and power dynamism rather than seeking the solutions for these contradictions.     

Relationship between the internal locus of control and collective action: A comparison of East Asian and Western Countries

This study tested factors related to collective action in East Asian and Western countries. Although the social identity model of collective action (SIMCA) could explain which factors relate to collective action in Western countries, previous studies have found that some of the SIMCA variables did not predict collective action in non‐Western countries. We hypothesised that the internal locus of control would be positively related to collective action even in East Asian countries because previous studies have demonstrated that the former can positively influence proactive behaviour when factors inhibiting such behaviours exist. We analysed the 2010 World Values Survey data from seven countries (three East Asian and four Western countries). The results demonstrated that the internal locus of control was positively related to collective action more so among East Asians (Koreans, specifically those with low political interests, the Taiwanese, and Japanese people with lower income) than among Westerners. These results suggest that the internal locus of control is a key individual difference that predicts collective action in the presence of factors that inhibit such participation (e.g., cultural values, low political interest, and low income).     

Social Networks as a Factor in Volunteering Among Elderly Japanese with Lower Socioeconomic Status

We investigated the effect of social networks on volunteering, which is known to be beneficial for people and society, among elderly Japanese of lower socioeconomic status. Western studies have demonstrated that social networks boost volunteering among wealthy people because of the norm that they should help the less fortunate. However, wealthy East Asians do not share this norm. Therefore, socioeconomic variables and volunteering tend not to be significantly related in Japan. We hypothesized that social networks would be more important to volunteering among the Japanese elderly, especially among people of a lower socioeconomic status. A total of 768 respondents (319 men, 432 women, 17 sex unspecified; M_age = 73.99 years, SD = 7.40 years) completed the survey. The results indicated that social networks were positively related to volunteering only among people with lower financial status. This result suggests that social networks can increase opportunities and help less advantaged elderly people to reap the benefits of volunteering.     

Influence of Speed and Accuracy Constraints on Motor Learning for a Trajectory-Based Movement

This study investigated the influences of task constraint on motor learning for a trajectory-based movement considering the speed–accuracy relationship. In the experiment, participants practiced trajectory-based movements for five consecutive days. The participants were engaged in training with time-minimization or time-matching constraints. The results demonstrated that the speed–accuracy tradeoff was not apparent or was weak in the training situation. When the participants practiced the movement with a time-minimization constraint, movement errors did not vary, whereas the movement time decreased. With the time-matching constraint, the errors decreased as a session proceeded. These results were discussed in terms of the combination of signal-dependent noises and exploratory search noises. It is suggested that updating spatial and temporal factors does not appear to occur simultaneously in motor learning.     

A longitudinal study of the moderating effects of social capital on the relationships between changes in human capital and ikigai among Japanese older adults

Ikigai, one of the indices of well‐being, tends to decline with age because resources relating to ikigai decline. However, there are individual differences in this decline. This study tested for maintenance of ikigai among Japanese elderly, using a longitudinal study investigating the moderating role of social capital on the effects of changes in human capital on ikigai. We conducted a panel survey targeting 1,068 people (M age = 73.01 years) in 2013, and 686 people in 2017. The variables were ikigai, changes in human capital (self‐rated financial status, physical health) and social capital (social networks, trust in others), educational level, and control variables. Multiple regression analyses revealed the interaction effects of changes in physical health and changes in social networks (strong ties, weak ties) on follow‐up ikigai. Post hoc analyses indicated that declines in physical health predicted declines in ikigai among those whose social networks (strong ties and weak ties) had declined in the 4‐year study, but these relationships were not significant among those whose social networks had increased. The results suggest that older adults can weaken the adverse effect of a decline in human capital on ikigai by maintaining or increasing social networks.     

Influence of instruction on evaluation of repeated muscular endurance

This study was done to examine the influence of instructions on the evaluation of rhythmic repeated muscular endurance, that is, the ability to continue muscle-power exertion at a regular interval. 15 healthy young male adults performed maximal repeated rhythmic grips for 6 min. under the following three instruction conditions: (1) "Squeeze freely during the 2-sec. interval," (2) "Squeeze quickly and then relax," and (3) "Squeeze quickly and then hold the exertion for 1 sec." Time to peak force was slower in Condition 1 than in Condition 2. A decline in exertion of force was found for all conditions after 1 min. The decline in rate of the peak values in Conditions 1 and 3 was about 10 to 15% larger than that of Condition 2. In conclusion, proper instructions are necessary, even for a short 2-sec. interval, when evaluating muscular endurance with repeated rhythmic grips. Condition 2 instruction may be most effective.     

Effects of arm stiffness and muscle effort on position reproduction error in the horizontal plane

present study investigated the effects of two-dimensional arm stiffness and muscle effort required to maintain horizontal arm posture on position-reproduction errors. 12 participants performed a multi-joint position-reproduction task without visual feedback. They were required to indicate a proprioceptively remembered target position with the fingertip of the ipsilateral arm. The results showed that both constant and variable errors were larger in the direction of lower stiffness rather than in the direction of higher stiffness in the stiffness ellipse. In the condition where participants' arm was supported during position perception, variable error was larger than when it was vertically unsupported. These results suggested that proprioceptive accuracy and precision are positively related to the axis length of elliptically represented arm stiffness, and that exerting muscle effort to maintain the arm against the force of gravity may be supportive of human proprioceptive mechanisms.     

The positivity scale

Five studies document the validity of a new 8-item scale designed to measure positivity, defined as the tendency to view life and experiences with a positive outlook. In the first study (N = 372), the psychometric properties of Positivity Scale (P Scale) were examined in accordance with classical test theory using a large number of college participants. In Study 2, the unidimensionality of the P Scale was corroborated with confirmatory factor analysis in 2 independent samples (N1 = 322; N2 = 457). In Study 3, P Scale invariance across sexes and its relations with self-esteem, life satisfaction, optimism, positive negative affect, depression, and the Big Five provided further evidence of the internal and construct validity of the new measure in a large community sample (N = 3,589). In Study 4, test-retest reliability of the P Scale was found in a sample of college students (N = 262) who were readministered the scale after 5 weeks. In Study 5, measurement invariance and construct validity of P Scale were further supported across samples in different countries and cultures, including Italy (N = 689), the United States (N = 1,187), Japan (N = 281), and Spain (N = 302). Psychometric findings across diverse cultural context attest to the robustness of the P Scale and to positivity as a basic disposition. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Neural mechanisms of spatial working memory: Contributions of the dorsolateral prefrontal cortex and the thalamic mediodorsal nucleus

The dorsolateral prefrontal cortex (DLPFC) has been known to play an important role in working memory. Neurophysiological studies have revealed that delay period activity observed in the DLPFC is a neural correlate of the temporary storage mechanism for information and that this activity represents either retrospective or prospective information, although the majority represents retrospective information. However, the DLPFC is not the only brain area related to working memory. The analysis of neural activity in the thalamic mediodorsal (MD) nucleus reveals that the MD also participates in working memory. Although similar task-related activities were observed in the MD, the directional bias of these activities and the proportion of presaccadic activity are different between the MD and the DLPFC. These results indicate that, although the MD participates in working memory, the way it participates in this process is different between these two areas, in that the MD participates more in motor control aspects than the DLPFC does.