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1.
Social dilemmas and the evolutionary conundrum of cooperation are traditionally studied through various kinds of game theoretical models such as the prisoner's dilemma, public goods games, snowdrift games or by-product mutualism. All of them exemplify situations which are characterized by different degrees of conflicting interests between the individuals and the community. In groups of interacting individuals, cooperators produce a common good benefitting the entire group at some cost to themselves, whereas defectors attempt to exploit the resource by avoiding the costly contributions. Based on synergistic or discounted accumulation of cooperative benefits a unifying theoretical framework was recently introduced that encompasses all games that have traditionally been studied separately (Hauert, Michor, Nowak, Doebeli, 2005. Synergy and discounting of cooperation in social dilemmas. J. Theor. Biol., in press.). Within this framework we investigate the effects of spatial structure with limited local interactions on the evolutionary fate of cooperators and defectors. The quantitative effects of space turn out to be quite sensitive to the underlying microscopic update mechanisms but, more general, we demonstrate that in prisoner's dilemma type interactions spatial structure benefits cooperation-although the parameter range is quite limited-whereas in snowdrift type interactions spatial structure may be beneficial too, but often turns out to be detrimental to cooperation.  相似文献   

2.
Subtle contextual social cues and the explicit incentive structure of social dilemmas are two important, but fundamentally different classes of determinants of cooperative behavior. The former provides subjective social information regarding the likelihood of attaining mutual cooperation by shaping one's expectations of the cooperative behavior of the interacting party. The latter provides objective, ecological information about the strategic opportunities offered by the situation. In prior research, both classes have generally been studied in isolation, hampering insight into how social judgments and ecological opportunities interact in shaping cooperation. To fill in this gap we set up a repeated mixed-motive game in which we manipulate subtle social cues and the incentive structure of the game simultaneously. We develop the hypothesis that social information is less important in shaping mutual cooperation of two team members when the incentive structure is such that it contains natural synergies. In contrast, when the incentive structure offers no synergy, “rational contracting” is hampered and social cues are essential for mutual cooperation to develop. The evidence we present in this paper is consistent with this hypothesis.  相似文献   

3.
公立医院是我国医疗服务的主体,同时也是社会责任的必然承担者。公益化视角下公立医院在获取自身生存和发展的同时,应最大程度地承担起“救死扶伤、生命至上”的社会责任新内涵。公立医院社会责任缺失与医疗市场越位、政府补偿缺位及医务人员宗旨意识错位有关。公益化视角下公立医院社会责任体系重建要改革公立医院运行机制、统筹利用社会各方力量、积极营造社会责任的文化氛围、提高医院综合管理水平及建立基于公益性的绩效考核方案。因此,要发挥公立医院社会责任要正确认识公立医院社会责任本质,应正确处理好社会责任与经营性之间的关系及充分发挥公立医院社会责任的利益相关方力量。有关企业社会责任及治理结构的理论和方法对研究医院相关问题有重要借鉴作用,但不能照搬,中国经济、管理和卫生领域专家在公立医院社会责任及实现机制方面的探索还有许多工作要做。  相似文献   

4.
The emergence and maintenance of cooperation by natural selection is an enduring conundrum in evolutionary biology, which has been studied using a variety of game theoretical models inspired by different biological situations. The most widely studied games are the Prisoner's Dilemma, the Snowdrift game and by-product mutualism for pairwise interactions, as well as Public Goods games in larger groups of interacting individuals. Here, we present a general framework for cooperation in social dilemmas in which all the traditional scenarios can be recovered as special cases. In social dilemmas, cooperators provide a benefit to the group at some cost, while defectors exploit the group by reaping the benefits without bearing the costs of cooperation. Using the concepts of discounting and synergy for describing how benefits accumulate when more than one cooperator is present in a group of interacting individuals, we recover the four basic scenarios of evolutionary dynamics given by (i) dominating defection, (ii) coexistence of defectors and cooperators, (iii) dominating cooperation and (iv) bi-stability, in which cooperators and defectors cannot invade each other. Generically, for groups of three or more interacting individuals further, more complex, dynamics can occur. Our framework provides the first unifying approach to model cooperation in different kinds of social dilemmas.  相似文献   

5.
随着世界人口不断增长、自然资源的不断减少 ,人类所面临的环境挑战正日趋严峻。防护林以其防护性、资源性和可再生性等强大的森林功能作为迎接这一挑战的工具 ,在环境保护与资源管理中正在发挥着愈来愈大的作用 ,世界各国对此都给予了极为广泛的重视。中国的防护林建设经营历史悠久 ,尤其是自1978年启动了三北防护林体系工程以来 ,以防护林为主体的林业生态工程已在中华大地蓬勃发展起来 ,其数量之多、规模之大已为全球所瞩目 ;防护林的生态、经济和社会效益与日俱增 ,为保障西部开发 ,控制三北地区的风沙干旱、水土流失等自然灾害 ,提高农…  相似文献   

6.
LCA in Japan: policy and progress   总被引:1,自引:0,他引:1  
A summary of the current Japanese activities related to Life Cycle Assessment are presented with a specific comparison of Life Cycle Impact Assessment in relation to European tendencies. Japanese organizations involved in LCA, recent legislation impacting LCA activities and LCA case studies are also tabulated. The LCA priorities of policy makers and industrialists are discussed in comparison and compared to those in the United States. Projects within the Life Cycle Assessment Society of Japan and the Man-Earth Project are highlighted including the construction of a public LCI data base and the prediction of 21st century environmental crises.  相似文献   

7.
8.
The complexity of human's cooperative behavior cannot be fully explained by theories of kin selection and group selection. If reciprocal altruism is to provide an explanation for altruistic behavior, it would have to depart from direct reciprocity, which requires dyads of individuals to interact repeatedly. For indirect reciprocity to rationalize cooperation among genetically unrelated or even culturally dissimilar individuals, information about the reputation of individuals must be assessed and propagated in a population. Here, we propose a new framework for the evolution of indirect reciprocity by social information: information selectively retrieved from and propagated through dynamically evolving networks of friends and acquaintances. We show that for indirect reciprocity to be evolutionarily stable, the differential probability of trusting and helping a reputable individual over a disreputable individual, at a point in time, must exceed the cost-to-benefit ratio of the altruistic act. In other words, the benefit received by the trustworthy must out-weigh the cost of helping the untrustworthy.  相似文献   

9.
In Japan, suicide has long been depicted as an act of free will, even aestheticized in the cultural notion suicide of resolve. Amid the record-high Japanese suicide rates since the 1990s, however, Japanese psychiatrists have been working to medicalize suicide and, in the process, confronting this deeply ingrained cultural notion. Drawing on two years of fieldwork at psychiatric institutions around Tokyo, I examine how psychiatrists try to persuade patients of the pathological nature of their suicidal intentions and how patients respond to such medicalization. I also explore psychiatrists' ambivalent attitudes toward pathologizing suicide and how they limit their biomedical jurisdiction by treating only what they regard as biological anomaly, while carefully avoiding the psychological realm. One ironic consequence of this medicalization may be that psychiatrists are reinforcing the dichotomy between normal and pathological, "pure" and "trivial," suicides, despite their clinical knowledge of the tenuousness of such distinctions and the ephemerality of human intentionality. Thus, while the medicalization of suicide is cultivating a conceptual space for Japanese to debate how to bring the suicidal back onto the side of life, it scarcely seems poised to supplant the cultural discourse on suicide that has elevated suicide to a moral act of self-determination.  相似文献   

10.
Self-pollination of Asarum caulescens Maxim. (Aristolochiaceae) in Japan   总被引:1,自引:1,他引:0  
Abstract Observations in two populations of Asarum caulescens belonging to sect. Asarum indicate that inbreeding predominates becuase (1) no effective pollinator was observed, (2) bagged flowers set fruits with well-swollen seeds, and (3) the behaviour of filaments, changing from recurved to straight posture, results in direct deposition of pollen grains on the stigmas. This result agrees with reports on three other species of sect. Asarum in Europe and North America. We suggest that species of sect. Asarum diverged from an autogamous ancestor.  相似文献   

11.
T. Hosoya 《Mycoscience》2002,43(1):0047-0057
Three Hyphodiscus species are described and illustrated: Hyphodiscus otanii sp. nov., Hyphodiscus hymeniophilus, and H. theiodeus, which is new to Japan. Culture studies revealed Phialophora-like anamorphs. Catenulifera gen. nov. is proposed for the anamorph of Hyphodiscus. The history of the genus is reviewed. Hyphodiscus can be delimited to members with gelatinized excipulum, Cistella-like hairs with more coarse granulation, small asci, ascospores with conspicuous globules, cylindrical, flexuous paraphyses, and a Catenulifera anamorph. Received: September 6, 2001 / Accepted: October 4, 2001  相似文献   

12.
In 1998, the Japan’s Ministry of Economy, Trade, and Industry (METI) launched a five-year national project entitled ‘Development of Life Cycle Impact Assessment for Products’ (commonly known as ‘the LCA Project’). The purpose of the project is to develop common LCA methodology as well as a highly reliable database that can be shared in Japan. Activities over these five years have resulted in the supply of LCI data on some 250 products. Industrial associations voluntarily provided data. The results of these activities are currently being made available on the Internet on a trial basis in the form of an LCA database. In addition, a method entitled ‘Life-cycle Impact assessment Method based on Endpoint modeling (LIME)’ was developed. It is expected that these results will be widely used in Japan in the future. This paper presents an outline of the results of the research and development that has been conducted in the LCA Project in Japan.  相似文献   

13.
The transportation of hazardous goods by road implies a risk for both humans and the environment, in that an accident involving a vehicle transporting this kind of material may cause extensive material and environmental damage and might even endanger lives. For this reason, both public and private entities (e.g., insurance companies) have a growing interest in studies that assess the risks associated with hazardous goods transportation This article describes a method for calculating these risks. The risk is determined on the basis of a calculation of the probability of the occurrence of an accident and the gravity of the damage, which is in turn a function of the potential damage inherent in the goods being transported taken with the vulnerability of the environmental medium in which the accident takes place. The mathematical model proposed is easily implemented in a geographical information system that will produce risk maps delimiting the more potentially conflictive stretches of roadway.  相似文献   

14.
Studies of blackfly vectors of Onchocerca dewittei japonica Uni, Bain & Takaoka (Spirurida: Onchocercidae), a parasite of wild boar implicated in the aetiology of zoonotic onchocerciasis in Japan, and six other zoonotic Onchocerca species of this country are reviewed. Molecular identification of infective larvae found in wild‐caught female blackflies showed that Simulium bidentatum (Shiraki) (Diptera: Simuliidae) is a natural vector of O. dewittei japonica, and also Onchocerca sp. sensu Fukuda et al., another parasite of wild boar. Inoculation experiments demonstrated that Simulium arakawae Matsumura and four other Simulium species are putative vectors. Similarly, S. arakawae, S. bidentatum and Simulium oitanum (Shiraki) are putative vectors of Onchocerca eberhardi Uni & Bain and Onchocerca skrjabini Rukhlyadev, parasites of sika deer. Morphometric studies of infective larvae indicated that Onchocerca lienalis Stiles, a bovine species, is transmitted by S. arakawae, Simulium daisense (Takahasi) and Simulium kyushuense Takaoka, and that Onchocerca sp. sensu Takaoka & Bain, another bovine species, is transmitted by S. arakawae, S. bidentatum, S. daisense and S. oitanum. Prosimulium sp. (Diptera: Simuliidae) and Simulium japonicum Matsumura are suspected vectors of Onchocerca suzukii Yagi, Bain & Shoho and O. skrjabini [Twinnia japonensis Rubtsov (Diptera: Simuliidae) may also transmit the latter], parasites of Japanese serow, following detection of the parasites' DNA genes in wild‐caught blackflies.  相似文献   

15.
The Japanese examination hell phenomenon is viewed as a series of crisis rites through which the child passes from family-centered to peer group-centered values in a particularistic society. It is held that this model has greater explanatory power than the minimization of competition model proposed by others and that it also helps to explain the phenomenon of student radicalism and centrifugal relationships in middle-class communities.  相似文献   

16.
17.
The juvenile development of four Japanese flatheads (Platycephalidae),Onigocia macrolepis. O. spinosa, Inegocia japonica andRogadius asper, is described and illustrated from specimens trawled in Tosa Bay, southern Japan. Juveniles of twoOnigocia species are diagnosed by an ocular flap and absence (O. macrolepis) or presence (O. spinosa) of distinct dark bars on the body.Inegocia japonica juveniles are distinctive in having a heavily pigmented body and 12 dorsal and anal fin soft rays.Rogadius asper has a unique antrorse preopercular spine prior to 15 mm SL. During the early juvenile stage, strongly negative allometric growth occurs in the interorbital region, accompanied by migration of the eyes from the lateral to dorsal surface of the head.  相似文献   

18.
19.
Leonor Michaelis spent the years of 1922–1926 as Professor of Biochemistry of the Aichi Medical College (now Graduate School of Medicine, Nagoya University) in Nagoya, Japan. Michaelis succeeded in gathering many bright young biochemists from all over Japan into his laboratory, and made tremendous contributions to the promotion of biochemistry in Japan. Michaelis was invited to many places in Japan to present lectures over those years. Kunio Yagi, who was Professor of Biochemistry at Nagoya University in the second half of the 20th century, succeeded in crystallizing the “Michaelis” enzyme–substrate complex. Historically, Michelis has had an enormous impact on biochemistry in Japan.  相似文献   

20.
The distribution of Sika deer (Cervus nippon) on Japanese islands is biased toward, the east where there is less snow. To explain this biased distribution in relation to snow, the foot morphology of Sika deer was measured. Hoof load was greatest in male adults (0.78 kg cm−2) and smallest in fawns (c 0.43 kg cm−2). The values were similar to those for white-tailed deer, and were smaller than those for snow-adapted species like caribou and chamois. Foreleg length wasc. 50 cm and 60 cm, and hind feet (lower half) length wasc. 40 cm and 45 cm for fawns and adult deer, respectively. Chest heights werec. 45 cm and 53 cm for fawns and adults, respectively. These figures suggest that areas where snow accumulates deeper than 50 cm are not favorable as a Sika deer habitat. The present distribution of Sika deer is clearly related to snow depth: they are mostly concentrated in the ‘preferable area’ of <50 cm of snow, some of them can live in the ‘habitable area’ of 50–100 cm of snow, and they rarely live in the ‘inhabitable area’ of >100 cm of snow.  相似文献   

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