Abnormal trend in mortalities of cohorts born in the early Showa Era was reported by Okubo and others based on quinquennial mortalities of 5-year birth cohort . However, the results of those studies not always coincide in birth cohorts and causes of death for which abnormal trends were noticed. In this study cohort mortalities were calculated for single year birth cohort from 1950 through 1985 and analysed. Abnormal trend in mortalities for around 1930 birth cohorts were clearly observed among males, starting at age of 35 years, in general, as a poor improvement of mortality for all causes and many of the main chronic degenerative diseases. An extent of cohorts and causes of death for which abnormal trends were observed were fully examined. As to the cohort abnormal trends were observed in 1927 to 1932 born cohorts, 1929 and 1931 as a focus. In causes of death all causes, malignant neoplasms (all sites, stomach and lung), cerebrovascular diseases, heart diseases, chronic liver diseases and cirrhosis, and diabetes mellitus showed abnormal trends. Similar but weak trends were seen for ulcer of the stomach and duodenum, and suicide but there noticed stronger period effects than cohort's. Factors related to those abnormal trends of mortalities remained undefined but supposedly susceptibilities for those diseases might have been induced by poor nutritional conditions prevailed during their midteen's, the second growth accelerating period, due to the social and economic chaos just after the World War II. Controus maps method used in this study gave clearer visual images for age, period, and cohort effects and is useful in mortality analysis.
The purpose of this research is to identify the food intake structure in terms of breakfast, lunch and dinner. The research sample is a group of house-wives in a sub-urban rural area in the Chiba prefecture. The survey was conducted eleven times every year from 1978 to 1989 except 1988. Findings are followings. 1. Nutrition intake per person per day in these years shows similar trend with the National Nutrition Survey for every year. This sample is relevant to analyze as a sample of the Japanese population. 2. Although the total intake of the staple foods like rice, bread, noodle decreased in these 12 years, the intake of rice has been constant and showed major portion of the staples. The intake of bread is limited for breakfast. 3. In each year, the rice intake in a day is allocated about 30% for each meals and the rest for snacks between meals. 4n the other hand, bread and noodle shows too much variation from year to year to analyze as a single food item. 4. As the main sources of protein, the intake of fishes, meats and eggs have increased in the twelve years. While fishes and meats are mostly consumed at lunch and dinner, eggs are at breakfast. 5. Factor analysis for each meal was conducted using 13 food groups, in which rice, bread and noodle are collected into a item of grain. While the grain group does not show any significant role, the selection of protein sources is suggested as an important factor from the analysis. 6. This method based on each meal indicates a significant role for the further nutrition education at a community level.
The purpose of this study is re-evaluation of population dynamics, especially of marriage, divorce, and birth and stillbirth by legitimacy, in Japan before the first population Census. Formerly we reported results of similar analysis for the period between 1872 and 1898. In this study, we have investigated the successive period from 1899 to 1919 which is the preceding year of the first Census. The marriage rates over this period were estimated to be around 50 to 60 per 1, 000 unmarried women over age 15. These figures are very low in comparison with those of the period after 1920. The official statistics of population before 1920 was based on "the Koseki (family registration system)" in contrary to the census after 1920. This difference may contribute the lower marriage rates for the period of this study. The divorce rates were estimated to be 6.0 to 8.4 per 1, 000 married women and showed a clear decrease since 1899. The illegitimate birth was found to be very frequent in the study period. It was estimated that one out of fifty unmarried women beared one child per annum. But the ratio of illegitimate births to all birth had showed a decline since 1912. The sex ratio of illegitimate birth was found to be lower than that of legitimate birth. The illegitimate stillbirth rates were around two and a half times higher than those of the legimate. It is considered that the enactment of the Civil Law in 1898 had contributable influence on these trends of marriage, divorce and the legitimacy of child.
The natural environment of Yaeyama Islands of Okinawa Prefecture are classified into two types; one is Iriomote Island, a large main island which is covered by many mountains and paddy fields, and inhabited by Anopheles minimus, a vector of Plasmodium falciparum, and the other is non endemic peripheral small dry islands of coral reef which have no swamps and paddy fields. Inhabitants of the non-endemic islands engaged in inter-islands cultivation. They stayed in the malaria-endemic island for various periods from one day trip to seasonal staying, the cultivation of rice and getting resources from the forest. This study based on the hearing to the inhabitants and participant observation in Iriomote, an endemic island. They had immigrated from one of the non endemic islands, Aragusuku since the year of 1941. The author tried to reorganize the inter-islands cultivation in the past day and to evaluate the efficiency for the subsistence economy and the adaptation to malaria. On the subsistence economy, inhabitants of Aragusuku had cultivated several crop species like millet and sweet potato by the swidden agriculture and mixed cultivation under a rotation system. Added by the inter-islands cultivation, they cultivated rice and got firewoods and woods for materials for houses from Iriomote Island. Activities in the both islands were essential for their subsistence, as their home island had neither paddy fields nor forests. Hunting wild boars and cattle-breeding were also carried out only in Iriomote Island. Quinine and traditional herbaceous medicines used for the treatment of malaria seemed to have limited effects, i.e., reducing symptoms of malaria, such as fever, discomfort and so on. No effective preventive measures against mosquito-biting was carried out in staying while the endemic island. Invasion of malaria was prevented primarily by limiting the person to stay in Iriomote Island only to male adults excepting the vulnerable group, women and children. It is concluded that the selective participation in inter-islands cultivation was most effective adaptive behavior for reconciling the discrepancy between the benefits of subsistence economy and the disadvantages of the epidemic of malaria.