Generation carryover of a fraction of population members as an animal adaptation to unstable environmental conditions

Summary A heterogeneous life cycle of individuals in a population was examined on its adaptive significance to an unstable environmental condition. The trend of population growth was simulated by a simple mathematical model in which a part of population in a certain generation was carried over to the next generation without participating in the reproduction. With the increase of the rate of carryover of individuals to the next generation the population fluctuation tended to be stabilized. A minute fraction of population is carried over, the effect is very large to prevent the population decline at a sequence of adverse environmental conditions. The population level increased greatly depending upon the extent of environmental change as far as the rate of carryover took an intermediate value. The optimum proportion of members to be carried over to the next generation was determined by the extent of environmental change and its frequency of occurrence. Contribution from the Entomological Laboratory, College of Agriculture, Kyoto University, No. 451.     

Generation carryover of a fraction of population members as an animal adaptation to unstable environmental conditions

A heterogeneous life cycle of individuals in a population was examined on its adaptive significance to an unstable environmental condition. The trend of population growth was simulated by a simple mathematical model in which a part of population in a certain generation was carried over to the next generation without participating in the reproduction. With the increase of the rate of carryover of individuals to the next generation the population fluctuation tended to be stabilized. A minute fraction of population is carried over, the effect is very large to prevent the population decline at a sequence of adverse environmental conditions. The population level increased greatly depending upon the extent of environmental change as far as the rate of carryover took an intermediate value. The optimum proportion of members to be carried over to the next generation was determined by the extent of environmental change and its frequency of occurrence.     

Household migration as a livelihood adaptation in response to a natural disaster: Nicaragua and Hurricane Mitch

This study uses data drawn from the Nicaragua Living Standards and Measurement Study Survey to examine international livelihood migrations from Nicaragua in the years surrounding the rapid-onset Hurricane Mitch event of 1998. The likelihood of an international livelihood migration occurring between the years 1996 and 2001 is modeled utilizing discrete-time event history analysis. While findings indicate no influence of Hurricane Mitch on likelihood of livelihood migration, the Mitch event is associated with increased migrant selectivity according to past household migration experience for migrations to Costa Rica, suggesting these migrations to be livelihood adaptations of those with high capability in the form of access to migrant social networks. In addition, the Mitch event is found to be associated with decreased likelihood of migration by small business owners. This finding is interpreted as reflecting business owning households choosing to forego sending migrants to instead have ‘all hands on deck’ to assist with business operations.     

Flower nectar of an autogamous perennialRorippa indica as an indirect defense mechanism against herbivorous insects

This report shows that one of the most important roles of the flower nectar of an autogamous perennialRorippa indica (L.) Hieron is as an attractant for employing some ant species as a defense against herbivorous insects. The plant has flowers from spring to early winter. Its flower nectar is frequently stolen by some ant species (hereafter cited as ants) which also feed on small herbivorous insects on the plant. Internations among the tritrophic levels (R. indica, herbivores, ants) were experimentally examined and the followings became clear. (1) Ants were attracted toR. indica in search of its flower nectar. (2) The gradual secretion of flower nectar seemed to detain ants on the plant. (3)Pieris butterfly lavae were the major herbivores onR. indica and were potentially harmful to the plant. (4) The presence of ants reduced the survival rate ofP. rapae larvae onR. indica. (5) The presence of ants reduced the feeding damage toR. indica. (6) The disadvantage of nectar use by ants seemed to be minimal for the plant since the ants did not disturb the other flower visitors. These facts suggest a mutualistic relationship betweenR. indica and ants. That is, the flower nectar serves as an indirect defense against herbivorous insects.     

2000-2010年中国育龄妇女生育完成度变化分析

新中国成立以来,妇女不论在社会活动领域还是家庭领域的地位都有了质的变化。妇女可以参与各种政治、经济、文化娱乐等活动,有的妇女在家庭领域的地位甚至超过了丈夫。尽管妇女受教育程度提高了,但与男性相比还有一定的差距。有研究表明:受教育程度和生育水平呈负相关,尤其是母亲的受教育水平影响更显著。由于教育的影响,妇女的生育水平和生育时间都发生了很大的变化。文章利用最近两次中国人口普查数据来研究育龄妇女的生育年龄的完成度变化情况,并对中国目前TFR很低的现象做了解释,据此推断中国在未来几年的时间,总和生育率会在一定程度上呈上升的变化趋势,但不可能在短期内回升到更替水平。     

从可持续发展的"生殖健康"理论到深化计划生育"生殖保健服务"的实践与思考

文章探讨了建瓯市在生殖保健服务方面的实践经验,把这一经验提高到可持续发展理论层面上来认识,并就如何深化计划生育生殖保健优质服务进行思考。     

Reproductive strategy of the sugi bark borer,Semanotus japonicus (Coleoptera: Cerambycidae) on Japanese cedar,Cryptomeria japonica

The inner bark of Japanese cedar,Cryptomeria japonica D. Don., is the main food of the sugi bark borer,Semanotus japonicus Lacordaire, but may also be involved in resistance to attack by the borer. I used newly hatched larvae to inoculate cedar logs that had been cut 2-weeks to 12-months earlier, and undamaged living cedar trees. On living trees, all larvae were killed by resin flow from the traumatic resin canals between the outer- and inner bark or between the inner bark and cambium. In logs that were cut more than 4 months prior to inoculation, larvae were unable to complete development. In logs cut 2 weeks prior to inoculation, almost all larvae were able to reach the adult stage but they were smaller in size than adults from living trees damaged by this borer. These results suggest that poor nutrient conditions in the inner bark of logs affected development and survival of the borer. Because of its nutritional advantage, living cedars provide a better environment for the sugi bark borer. However, all larvae are killed by resin flow, suggesting that this insect is “in between” being primary and secondary with respect to living trees, or a “weak” primary insect. The sugi bark borer seems to develop early in the season so that early instar larvae encounter reduced amounts of resin flow and so that late-instar larvae feed mostly in summer when nutrient levels in the inner bark are at their highest.     

The adaptive significance of leaf-mining pattern as an anti-parasitoid strategy: A theoretical study

Summary An adaptive significance of linear leaf mining patterns as the anti-parasitoid strategy is theoretically analysed. In the model, a leaf-miner is allowed to move in one of four ways; mining ahead in unexploited area of a leaf, backtracking, branching off from the backtracking mine, and crossing the previous mine. The model parasitoid searches for the leaf-miner by tracing the mine by the tactile cue of mine surface after detecting the mine. The average duration from detecting the mine to finding the leaf-miner host is calculated for various patterns of mining, changing numbers of branches and of crosses. This average duration becomes longer when the leaf-miner stays near either end of the mine compared with when staying near its center. It is also prolonged as the numbers of branches and of crosses increase.     

The strength of primordial ties: Suburban community adaptation to school system retrenchment

Communities and local schools are attached to one another for many other reasons than the purely instrumental objectives of educating children. These highly symbolic interpenetrations of community and school include considerations of diffuse communal identity, religion, and ethnicity. Taken together with different priorities about wider educational goals, these narrower community objectives for local schools put contradictory strains on community-school relations in the heated climate of increased community participation in contracting school systems. Competing claims about the central purposes of local schools become extraordinarily salient parts of the external environment of school districts experiencing contraction, and play a major role in the process of adapting school district organizations to conditions of decline. For many citizens the desire to preserve the local symbolic and non-instrumental roles of neighborhood schools, in particular, may at times outweigh the goal of maintaining quality educational service delivery as seen from the perspective of school managers. For other citizens, the protection of quality programs, serving their children as stepping-stones to the wider society, outweighs considerations of local neighborhood solidarity and identity in adapting to declining enrollments and fiscal strains in the schools.An earlier version of this article was delivered at the 1984 Midwest Sociological Society Annual Meeting in Chicago. I am grateful to Virginia Bartot, Sally B. Kilgore, Gerald D. Suttles, and an anonymous reviewer for comments and suggestions.     

加强培训，发挥B超在生殖健康服务中的作用

本文根据兰州市计划生育B超技术服务人员的现状,提出了有针对性的分层次培训的目标、内容和方法。     

Migration and climate change: examining thresholds of change to guide effective adaptation decision-making

The implications of environmental change for migration are little understood. Migration as a response to climate change could be seen as a failure of in situ adaptation methods, or migration could be alternatively perceived as a rational component of creative adaptation to environmental risk. This paper frames migration as part of an adaptation response to climate change impacts to natural resource condition and environmental hazards. Thresholds will be reached by communities after which migration will become a vital component of an effective adaptation response. Such changes to migration patterns have the potential to undermine migration policy unless appropriate preparations are undertaken. This paper describes an approach to assist researchers to frame how climate change will influence migration by critically analysing how thresholds of fundamental change to migration patterns could be identified, primarily in relation to two case studies in Nepal and Thailand. Future policy for internal and international migration could be guided by the analysis of such thresholds of non-linear migration and resourced effectively to ensure that socio-economic and humanitarian outcomes are maximised.     

Fertility adaptation of rural-to-urban migrant women: A method of estimation applled to Korean women

This study proposes to test for the existence of an adaptation effect of rural-to-urban migration. The design is to divide migrants into two groups at the time of observation: one group which had migrated by that time, and another group consisting of individuals who had not yet migrated but are known to migrate later. It is presumed that if the former group had not migrated it would have had a birth path similar to the latter group. Adaptation is measured by the difference between this hypothetical birth path and the actual birth path of migrants observed after they migrate. The model is tested on Korean women and found to support the existence of an adaptation effect.     

Creative work environments in sport organizations: the influence of sexual orientation diversity and commitment to diversity

Drawing from creative capital theory, the purpose of this study was to examine the degree to which sexual orientation diversity and commitment to diversity were predictive of workplaces that fostered creativity. Data were collected from 653 senior level athletic administrators and aggregated to the athletic department level of analysis (n = 199). Moderated regression indicated that sexual orientation diversity did not influence the presence of a creative work environment. There was however, a significant sexual orientation diversity × commitment to diversity interaction. When commitment to diversity was high, there was a positive association between sexual orientation diversity and a creative work environment; on the other hand, when commitment to diversity was low, the aforementioned relationship was negative. Results provide support for the notion that all diversity forms can be a source of enrichment and understanding, thereby benefiting the workplace.     

计生家庭状况及其生育补偿研究

通过大量的调查数据,本文重点考察、分析了我国计生家庭和计生父母面临的问题以及获得的救助、补偿等生育补偿情况,最后从转变生育补偿观念、改进生育补偿方法和加大生育补偿力度等方面提出相应的对策研究。     

生育公平、人口质量与中国全面鼓励二孩政策

中国的计划生育政策并不是绝对的"一对夫妇只生育一个孩子"的"一孩政策",而是表现出明显的多样性和差异性。当前的全面二孩政策既解决了"一孩政策"约束下的生育不公平,又避免了"多孩政策"带来的人口质量问题,是中国计划生育政策改革的一大进步。但是,在中国总和生育率长期低于更替水平,甚至即将掉入"低生育率陷阱"的背景下,根据发达国家的经验,结合国内六个地区的二孩政策生育实践,中国计划生育政策改革的当务之急,不应仅停留在全面放开二孩,也不应全面放开生育,而是要全面鼓励二孩,即对生育一个孩子的家庭不惩罚,对生育两个孩子的家庭进行奖励。这样的生育政策既符合中国计划生育政策"渐进调试,稳中求变"的发展路径,也有利于促进生育公平和人口质量提升。     

Dynamics of age- and size-structured populations in fluctuating environments: Applications of stochastic matrix models to natural populations

Recent developments of the theory of stochastic matrix modeling have made it possible to estimate general properties of age- and size-structured populations in fluctuating environments. However, applications of the theory to natural populations are still few. The empirical studies which have used stochastic matrix models are reviewed here to examine whether predictions made by the theory can be generally found in wild populations. The organisms studied include terrestrial grasses and herbs, a seaweed, a fish, a reptile, a deer and some marine invertebrates. In all the studies, the stochastic population growth rate (ln λ _s ) was no greater than the deterministic population growth rate determined using average vital rates, suggesting that the model based only on average vital rates may overestimate growth rates of populations in fluctuating environments. Factors affecting ln λ _s include the magnitude of variation in vital rates, probability distribution of random environments, fluctuation in different types of vital rates, covariances between vital rates, and autocorrelation between successive environments. However, comprehensive rules were hardly found through the comparisons of the empirical studies. Based on shortcomings of previous studies, I address some important subjects which should be examined in future studies.     

YouTube as a Site of Counternarratives to Transnormativity

ABSTRACT

In this article, I discuss how transnormativity can be disrupted by not exaggerating the physical aspects of medical transition and by engaging in conversations around consequential sources of tension within gender and sexual minority communities, namely linguistic understandings of trans and gendered racism within white, gay, cisgender communities toward trans communities of color. This study is based on qualitative interviews with six trans YouTubers; these interviews were complemented by analyses of these YouTubers’ videos and select comments on these videos. With this exploratory study, I aim to provide nuance to existing lesbian, gay, bisexual, and trans (LGBT) YouTube literature through highlighting the experiences of nonbinary trans vloggers and trans vloggers of color, regardless of medical transition status, as well as contribute a transfeminist analysis to ongoing conversations around transnormativity within sociology, cultural and media studies, and queer and trans theory.     

结构变迁理论视角下的流动穆斯林城市适应的障碍性因素分析——以兰州市回族、东乡族为例

随着城市化进程的加快,越来越多的少数民族人口进入城市,尤其是大城市。这一群体在接受＂城市化＂和＂现代化＂洗礼的过程中,相对于一般的进城务工人员,由于加入了民族意识、民族宗教习俗、民族价值文化等因素,从而使其城市适应变得更加复杂和艰难。本研究从社会结构变迁的角度出发,以兰州市流动穆斯林社会调查为基础,对影响流动穆斯林城市适应的障碍性因素（民族因素、自身因素、社会环境因素和制度因素）进行了深入、细致的分析;并阐述了流动穆斯林城市适应的关键障碍因素：地理距离、经济条件及心理文化。随着城市化进程的进一步加快,与以往的农民工城市适应的关键障碍因素不同,制度因素已不再是阻碍流动穆斯林城市适应最主要的因素,而是呈现出多元化的特点。     

Neighborhood naming as an index of attachment to place

One aspect of attachment to place may relate to neighborhood naming. That is, recent investigations have found that in many communities large numbers of residents can supply locality labels. The most recent studies, however, have failed to confirm the importance of local social involvement as a predictor of naming. Following the earlier suggestion of Shumaker and Taylor (1983) that attachment dynamics can operate at the group level, we focus on small, local groups by analyzing street blocks. Results support our hypothesis that groups with more shared local ties are more able to supply a neighborhood name. This relationship was also obtained when we examined purely individual-level covariation. Results underscore the multilevel nature of attachment processes and how they are both social and psychological in nature. Links between cognitive and affective components of attachment and practical outcomes such as local problem solving are discussed.