Population biology of the broad-horned flour beetle,Gnathocerus cornutus (F.) II. Crowding effects of larvae on their survival and development

Summary Crowding effects of larvae on survival and development were examined for the broad-horned flour beetle,Gnathocerus cornutus (F.). The larvae matured about 3 weeks after hatching regardless of their densities, but pupation was severely hindered by crowding. There existed an upper limit for the number of the pupae produced and its mechanism was studied by a statistical analysis of the distribution patterns of pupal cells and the experiment in which glass tubes were artificially supplied in addition as pupation site. These studies show thatG. cornutus larvae have a habit to construct cells for pupation and this habit leads to a contest competition for pupation site at high densities. The significance of the contest competition for population regulation was discussed comparing the results onTribolium confusum Jacqueline duVal.     

The approximation of an unbiased test with a small level for the bioequivalence problem

In the bioequivalence problem. Brown. Hwang and Munk (1997) constructed an unbiased level a test and other tests which are uniformly more powerful than the two one-sided tests procedures when a iscomparatively larger. In this paper, for a small level, an unbiased test is shown to be approxirnately constructeQ lor tnis prooiem oy using tneir Metnog. ine numerical construction is also given.     

Recovering Heritage and Homeland: Ethnic Revival Among Fourth‐Generation Japanese Americans

In recent years, fourth‐generation Japanese American youth have been attempting to recover their ethnic heritage and reconnect with their ancestral homeland. This ethnic revival is a response to their continued racialization as “Japanese,” which has caused them to become concerned about their overassimilation to American society in an era of multiculturalism where cultural heritage and homeland have come to be positively valued. As a result, they are studying Japanese, majoring in Asian studies, living in Japan as college exchange students, and participating in Japanese taiko drum ensembles in local ethnic communities. Although this return to ethnic roots is a more serious commitment than the symbolic ethnicity observed among white ethnics in the past, it indicates that ethnicity remains involuntary for racial minorities, even after four generations. The case of later‐generation Japanese Americans demonstrates that cultural assimilation does not preclude the continuation and active production of ethnic difference.     

Reproductive strategy of insects as adaptation to temporally varying environments

Summary Diversity of oviposition curve observed in 125 insects was analysed using the ratio of the length of period for development to that for reproduction. On the basis of this empirical data, two extreme reproductive patterns were selected: prolonged reproduction with early maturity and concentrated reproduction with late maturity. Population growth of the species with each reproductive pattern was calculated usingLeslie Matrix under some simulated fluctuating environments where the length of time during which the environments change is short compared with the time required to stabilize age structure. These simulation studies show that there is an optimal ratio of the length of period for development to that for reproduction in achieving high population densities and this ratio varies depending on the favorableness of environment for reproductive success: as the environmental favorableness decreases, the optimal ratio becomes larger.     

Defining and organizing self-advocate centered groups: implications of survey research on self-advocacy groups in Japan

Ideally group members who have intellectual disabilities should have power in their self-advocacy groups, leading to groups that can be considered 'self-advocate centered.' Currently, not all self-advocacy groups can be considered self-advocate centered because group advisors have an overwhelming influence on group decisions. This article assumes that establishing self-advocacy groups in which members truly control the agenda and make key decisions is one of the most effective methods to empower people with intellectual disabilities. This study identifies factors useful in identifying 'self-advocate centered' groups, and especially focuses on the relationship between self-advocates and advisors. It is based on a quantitative research project conducted in Japan. According to the results of the research, though relational transformation between self-advocates and advisors was commonly seen in many self-advocacy groups, conflicts between them were scarcely observed. The meaning of relational transformation without conflicts is considered, along with the concepts of independence and interdependence.