Seasonal host alternation by the andromeda lace bug,Stephanitis takeyai (Heteroptera: Tingidae) between its two main host-plant species

I studied the seasonal occurrence of the andromeda lace bug,Stephanitis takeyai, on its two main host-plant species. In a secondary forest in Kyoto, this bug altered its hosts seasonally, i.e., from an evergreen shrub,Pieris japonica, in winter to a deciduous shrub,Lyonia elliptica, in summer. In contrast, in Nara park where fewL. elliptica were available, the bug exploited onlyP. japonica. Thus, seasonal host alternation by this bug is not obligate. A comparison of adult longevity and fecundity on the two host-plant species demonstrated the higher quality ofL. elliptica as a food resource. Corresponding to this difference in host quality, there was a dramatic difference in the seasonal population growth in the two study sites. In Nara, the population size at the beginning of the 2nd generation was almost the same as in the overwintered generation, whereas in Kyoto the population size in the 2nd generation was approximately one hundred times as large as in the overwintered generation. Thus seasonal host alternation is adaptive for the bug. In a previous study, I reported that overwintering as eggs in living leaves of their hosts is likely to be common among all the related species of this bug. Thus, this trait can be considered to be a phylogenetic constraint to the group. I speculate that host alternation by this bug has been derived because it is more adaptive from autoecy on an evergreen plant, similar to the pattern currently found in Nara, and that this bug can not only exploit deciduous host due to a phylogenetic constraint.     

Unbiased Estimator for a Covariance Matrix Under Two-Step Monotone Incomplete Sample

In this article, we consider an inference for a covariance matrix under two-step monotone incomplete sample. The maximum likelihood estimator of the mean vector is unbiased but that of the covariance matrix is biased. We derive an unbiased estimator for the covariance matrix using some fundamental properties of the Wishart matrix. The properties of the estimators are investigated and the accuracies are checked by a numerical simulation.     

Expansion of formalized in-home services for Japan's aged

This article analyzes the social and political forces in Japan that led to the creation of the Gold Plan, a comprehensive national plan for formalized in-home services for the aged. The political strategies of the Gold Plan are examined from the following perspectives: (1) shifts from institutional to in-home services, (2) decentralization of in-home services policy, and (3) needs for expanding the number of in-home service workers. New nonprofit organizations called Resident-Participation Types (RPTs) are identified, which are self-help organizations to augment the delivery of in-home services to the aged. The current status of these new models for the aged are examined, using data from two different surveys conducted by the Japanese National Council of Social Welfare in 1992 and 1993. Finally, future issues regarding RTPs and in-home services for the aged and some policy recommendations are discussed.     

Closed testing procedures for all pairwise comparisons in a randomized block design

We consider multiple comparison test procedures among treatment effects in a randomized block design. We propose closed testing procedures based on maximum values of some two-sample t test statistics and based on F test statistics. It is shown that the proposed procedures are more powerful than single-step procedures and the REGW (Ryan/Einot–Gabriel/Welsch)-type tests. Next, we consider the randomized block design under simple ordered restrictions of treatment effects. We propose closed testing procedures based on maximum values of two-sample one-sided t test statistics and based on Batholomew’s statistics for all pairwise comparisons of treatment effects. Although single-step multiple comparison procedures are utilized in general, the power of these procedures is low for a large number of groups. The closed testing procedures stated in the present article are more powerful than the single-step procedures. Simulation studies are performed under the null hypothesis and some alternative hypotheses. In this studies, the proposed procedures show a good performance.     

中国壮族与越南侬族的民族关系与交流

侬族来自广西的壮族地区.壮族与侬族的文化在诸多方面有许多共同点.但是,壮族的汉化在进行,而由于受国境划分,中国王朝和汉族的影响没有直接波及侬族,因此侬族保留了更古老的习俗.尽管受国境划分,但两者间往来还持续着.虽然民族政策渗透而人们受国家的制约,但是人们在日常生活中,未必意识到国家,他们的生活圈很容易超越带有政治色彩的国境线.这种在人的生活世界中产生的国境的意义的问题,今后有进一步思考的必要.     

Gender Differences in the Effect of Job Characteristics on Work‐to‐Family Conflict in Japan: Application of the Job Demands‐Resources Model into Japanese Population1

This article uses the job demand‐resources (JD‐R) model to analyze the Japanese population and gender differences in work‐to‐family conflict in Japan. Using data from the International Social Survey Programme in 2015, the study addresses four main questions: (i) does the JD‐R model apply to the Japanese population? (ii) which gender is more likely to experience work‐to‐family conflict? (iii) does gender moderate the relationship between work‐related factors and work‐to‐family conflict? and (iv) do different factors predict work‐to‐family conflict between men and women? The findings show that the JD‐R model applies in part to the Japanese population, and women are more likely to experience a higher level of work‐to‐family conflict than men. There are also different factors predicting work‐to‐family conflict by gender, even though gender does not moderate the relationship between work‐related factors and work‐to‐family conflict. This article points out the peculiar Japanese social and cultural contexts that lead to gender differences in work‐to‐family conflict. It offers two solutions: (i) legal regulations to reduce working hours and the frequency of working on weekends to prevent work from intruding on family life; and (ii) changes to the work environment to make women workers more comfortable at work because of the male‐dominated workplace and Japanese culture on family gender roles in Japan.