Use of the regression of mean crowding on mean density for estimating sample size and the transformation of data for the analysis of variance

Summary An approximate method for estimating the sample size in simple random sampling and a systematic way of transformation of sample data are derived by using the parameters α and β of the regression of mean crowding on mean density in the spatial distribution per quadrat of animal populations (Iwao, 1968). If the values of α and β have been known for the species concerned, the sample size needed to attain a desired precision can be estimated by simply knowing the approximate level of mean density of the population to be sampled. Also, an appropriate variance stabilizing transformation of sample data can be obtained by the method given here without restrictions on the distribution pattern of the frequency counts. Contribution from the Entomological Laboratory, Kyoto University No. 418. Contributions from JIBP-PT No. 52. Aided in part by a grant from the Ministry of Education for the special project research, ‘Studies on the dynamic status of biosphere’.     

Interspecific competition between two species of Trichogrammatidae III The analytical study on the competition

Summary The experiment was carried out in order to analyze the results of interspecific competition which were mentioned in the previous reports (Sasaba 1964, 1965). The following definite tendencies were obtained and an account was given with regard to the process of competition. (1)T. minutum had a higher reproductive rate thanT. japonicum at a lower density of the parent wasps. (2) The parasitic efficiency ofT. minutum was high as compared withT. japonicum. (3)T. japonicum was consistently superior toT. minutum in the interspecific competition at larval stage. Contribution from the Entomological Laboratory, College of Agriculture, Kyoto University, No. 384.     

Secular declines in the association between obesity and mortality in the United States

Recent research suggests that rising obesity will restrain future gains in US life expectancy and that obesity is an important contributor to the current shortfall in us longevity compared to other high-income countries. Estimates of the contribution of obesity to current and future national-level mortality patterns are sensitive to estimates of the magnitude of the association between obesity and mortality at the individual level. We assessed secular trends in the obesity/mortality association among cohorts of middle-aged adults between 1948 and 2006 using three long-running US data sources: the Framingham Heart Study, the National Health and Nutrition Examination Survey, and the National Health Interview Survey. We find substantial declines over time in the magnitude of the association between obesity and overall mortality and, in certain instances, cardiovascular-specific mortality. We conclude that estimates of the contribution of obesity to current national-level mortality patterns should take into account recent reductions in the magnitude of the obesity and mortality association.     

Decomposition of the difference between two rates with hierarchical factors

A decomposition method for the difference between two rates when data are classified by two factors, one of which may be considered as a more direct factor than the other for the event under consideration, is presented in this paper. The two factors are treated as hierarchical and thus this method is conceptually different from the decomposition methods of Kitagawa (1955) and Das Gupta (1978), in which two factors are treated as symmetrical. Our method is shown to be a balanced version of the Cho-Retherford (1973) decomposition method. Analyses of neonatal mortality rates using our method are presented as an example.     

90年代以来甘肃省人力资本水平空间差异探讨

随着知识生产与创造的高素质科技劳动者逐步成为一个地区能否吸引现代经济活动的关键．人力资本在区域经济增长中越来越受到人们的关注。文章从时间和空间两方面入手．探讨了90年代以来甘肃省人力资本水平的空间差异及其变化状况。结果表明：甘肃省区域人力资本水平得到明显提高。人力资本水平的地理空间格局由1990年的中部高、西北和东南部低的“凸”字形分布渐渐转向2000年的中西北部高。而东南部低的倾斜式分布：区域人力资本水平差异仍然较大,其增长幅度的区域差异也十分显著。文章还就人力资本差异的形成机制进行了探讨,并提出了促使区域人力资本可持续发展的相关建议和对策。     

The association between the frequency of wife assault and marital dissolution in Canada

A strong positive association between wife abuse in the first marriage and the probability of that marriage ending is documented and investigated using the 1993 Violence Against Women survey (VAWS) for Canada and controlling for the endogeneity of abuse. A sensitivity analysis suggests that systematic reporting differences are not likely to account for the findings. Received: 2 June 1999/Accepted: 13 June 2000     

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.     

An experimental analysis of the relationship between species combination and community persistence

Among many stabilizing factors for community dynamics, nonlinear biological interactions such as type III functional response have been widely considered to be major characteristics. However, most experimental biological communities employed so far had quite simple structures. Therefore, the possibility that the conclusions in earlier studies were dependent on simple community structure is undeniable. In this study, using a multiple-species experimental community, we evaluated which combinations of component species and what kinds of interspecific interactions allow communities to persist and how these contribute to community persistence. We conducted experimental communities using two species of beans, the adzuki bean (Vigna angularis) and the red kidney bean (Phaseolus vulgaris), two species of bean weevils, the Mexican bean weevil (Zabrotes subfasciatus, Coleoptera: Bruchidae) and adzuki bean weevil (Callosobruchus chinensis, Coleoptera: Bruchidae), and two species of parasitic wasp, Heterospilus prosopidis (Hymenoptera: Braconidae) and Anisopteromalus calandrae (Hymenoptera: Pteromalidae). The outcome of multiple-generation experimental communities was explained by the characteristics of component species obtained from short-term experiments. In our two resources–two herbivores–one carnivore system, the strong density-dependent attack ability of one parasitic wasp species (A. calandrae) led to the extinction of C. chinensis. On the other hand, the weak density-dependent attack ability of the other parasitic wasp species (H. prosopidis) led to system persistence. Our overall results show that, in a multiple-species community, the combination of species itself is more important for community persistence than are the characteristics of the particular species. Received: September 29, 1997 / Accepted: October 5, 1998     

The association between midwifery staffing levels and the experiences of mothers on postnatal wards: Cross sectional analysis of routine data

BackgroundWomen have consistently reported lower satisfaction with postnatal care compared with antenatal and labour care. The aim of this research was to examine whether women’s experience of inpatient postnatal care in England is associated with variation in midwifery staffing levels.MethodsAnalysis of data from the National Maternity Survey in 2018 including 17,611 women from 129 organisations. This was linked to hospital midwifery staffing numbers from the National Health Service (NHS) Workforce Statistics and the number of births from Hospital Episode Statistics. A two-level logistic regression model was created to examine the association of midwifery staffing levels and experiences in post-natal care.ResultsThe median Full Time Equivalent midwives per 100 births was 3.55 (interquartile range 3.26–3.78). Higher staffing levels were associated with less likelihood of women reporting delay in discharge (adjusted odds ratio [aOR] 0.849, 95% CI 0.753–0.959, p = 0.008), increased chances of women reporting that staff always helped in a reasonable time aOR1.200 (95% CI 1.052, 1.369, p = 0.007) and that they always had the information or explanations they needed aOR 1.150 (95% CI 1.040, 1.271, p = 0.006). Women were more likely to report being treated with kindness and understanding with higher staffing, but the difference was small and not statistically significant aOR 1.059 (0.949, 1.181, p = 0.306).ConclusionsNegative experiences for women on postnatal wards were more likely to occur in trusts with fewer midwives. Low staffing could be contributing to discharge delays and lack of support and information, which may in turn have implications for longer term outcomes for maternal and infant wellbeing.     

On a method for estimating the rate of population interchange between two areas

Summary A method for estimating the rate of population interchange between two areas is described in this paper. It is applicable to the case where the sampling ratios and the survival factors of the populations on two areas are different from each other. From the marking-and-recapture data taken at three successive occasions, we can obtain the estimates of emigration factors, total survival factors over two areas and the ratio of surviving migrants to the total survivors over the two areas, for each of two populations initially living on different areas. Contribution from the Entomological Laboratory, Kyoto University, No. 369.     

广西农村贫富差距问题的实证分析

在文献研究的基础上,以农户作为分析单位,设计了广西农户经济状况的调查问卷。根据8个地市、202个农户的实证资料,运用SPSS软件：（1）描述了广西农户经济收入的状况及其构成;（2）计算了恩格尔系数和绝对贫困发生率;（3）揭示了广西农村贫富差距的事实。     

构建和谐社会过程中的基层老年群众组织作用研究——以老年人协会为例

老年人协会在构建和谐社会中具有重要作用。和谐社会与老年人的服务与权利保障之间具有互为因果的关系,这二者的互动关系需要以有效的老年群体组织为媒介和平台,才能有助于这种互动关系向着良性循环的方向发展。老年人协会是政府老龄工作职能转移的促进者与主要承接者;是促进民主建设的重要力量;老年人协会能促进良好的社会秩序的形成。目前老年人协会发展不平衡,老年人参与率低、经费短缺等影响了老年人协会的发展。因此需要建立、健全相关法律法规制度,为老年人协会发展提供稳定的保障,增强老年人协会功能。