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161.
Phenotypic manipulation reveals sexual conflict over precopula duration   总被引:1,自引:1,他引:0  
Sexual conflict is common in nature, but detailed behavioral studies on the role female resistance behavior plays in shaping mating patterns are rare. I manipulated female resistance to examine its effects on pairing dynamics in two ecologically different freshwater amphipods. I found evidence for female behavior playing a role in both the outcome of pre-pairing interactions and the initiation of pairing in both species. In these species, the male optimum pairing duration is greater than the value preferred by females or compromised pairing durations observed under natural conditions, thus indicating sexual conflict. Furthermore, the proportion of male–female encounters producing male grasping was greater and the duration of such interactions was longer when female resistance was reduced. Thus, sexual conflict over pairing duration may select simultaneously for female resistance and for male persistence both of which mediate the outcome of pre-pairing interactions in Hyalella. Contact precopulatory mate guarding and the interactions that precede it are common components of crustacean and insect mating systems, suggesting that such conflicts may play an important role in the evolution of mating traits in many taxa.  相似文献   
162.
人群拥挤事故与避灾心理分析   总被引:2,自引:0,他引:2  
化彬  江见鲸 《灾害学》1996,11(4):89-93
在现代社会中,大量的人群集中在一起是常见的事情。通常情况下,大量的人群集中并不会引起严重的问题,但有时由于缺乏有效的控制与管理,在突发事件发生时常会造成较大的人员死伤。本交通过对本世纪的若干起人群拥挤事故的调查,分析了该类事故的制约因素。  相似文献   
163.
Cease-fires in the Caucasus during the past five years have prevented large-scale life-threatening emergencies and created space for peace negotiations. Yet genuine conflict resolution and normalisation have proven elusive, frustrating the return of uprooted populations and constraining reconstruction. This paper reviews a series of seven strategy sessions held in Moscow and the Caucasus in late 1998 to reflect upon the performance of humanitarian agencies and stimulate greater synergies with diplomatic actors. An experiment in promoting discussion of recently conducted independent policy research throughout the north and south Caucasus, the series resulted in a fresh look at the issues in the region and at agency headquarters. The generic nature of the policy challenges gives the experience potential relevance well beyond the region.  相似文献   
164.
Summary. Queens in colonies of the small myrmicine ant, Leptothorax gredleri Mayr 1855 (Hymenoptera, Formicidae) engage in dominance interactions and form social hierarchies, in which typically only the top-ranking queen lays eggs. Occasionally, queen antagonism escalates to violent mandible fighting, during which the sting is used to apply Dufour gland secretions onto the cuticle of the opponent. Contaminated queens often are attacked by nestmate workers. Here we show that the chemical composition of the Dufour gland is colony-specific and that workers can discriminate between secretions from their own and other colonies. Our findings suggest that Dufour gland secretions are involved in the establishment of hierarchies within a colony. When invading an alien colony the queen presumably employs the secretions during the expulsion of the resident queen. Apparently, Dufour gland secretions play a role in intraspecific queen competition similar to that in slave-making and inquiline formicoxenine ants, where they function as "propaganda substances" in an interspecific context. Received 7 July 1998; accepted 15 September 1998.  相似文献   
165.
Women, Health and Humanitarian Aid in Conflict   总被引:4,自引:0,他引:4  
The burden of political conflict on civilian populations has increased significantly over the last few decades. Increasingly, the provision of resources and services to these populations is coming under scrutiny; we highlight here the limited attention to gender in their provision. Women and men have different exposures to situations that affect health and access to health-care and have differential power to influence decisions regarding the provision of health services. We argue that the role of women in planning is central to the provision of effective, efficient and sensitive health-care to conflict-affected populations.  相似文献   
166.
Joanna Macrae 《Disasters》1998,22(4):309-317
Over recent years, the humanitarian community has been under increasing scrutiny and attracted harsh criticism. This mounting critique of humanitarianism has shifted from being concerned primarily with the poor functioning of the humanitarian system to one targeted on basic humanitarian values. This paper is concerned to understand the factors driving the attack on humanitarian values. It identifies four apparently disparate groups who are interested in attacking these values: the anti-imperialists, the realpolitikers, the developmentalists and the neo-peaceniks. It concludes that unless humanitarian actors are aware of these diverse threats to their values and operations, they risk being co-opted or marginalised.  相似文献   
167.
ABSTRACT: The solution of a water resource allocation problem by an alternative social arrangement is presented. Classical Austrian economic theory and the “new resources economics” provide both theoretical and practical evidence to support the development of well-defined, private property rights to the water resource in question. A conflict analysis demonstrates that management of the Manayunk Canal by a firm would reconcile existing confrontations through compromise use of the water resource. Benefit and cost calculations show that a compromise among industrial and recreational interests, currently competing in the political arena, would increase social benefits.  相似文献   
168.
2018年夏季上海合作组织成员国元首理事会环境空气质量保障工作开始前,中国监测总站对山东、江苏2个省份19个城市共计85个国控站点开展O3专项质控工作。结果表明,保障区域O3监测数据低、中、高浓度点相对误差变异系数分别为4. 7%、4. 3%和4. 8%,95%预测区间分别为[-7. 4%,9. 0%]、[-6. 9%,8. 3%]和[-8. 0%,8. 4%]。与之相比,2018年全国范围内开展外部比对的1 346个国控站点O3监测数据低、中、高浓度点相对误差变异系数分别为7. 4%、6. 5%和6. 2%,95%预测区间分别为[-13. 1%,15. 4%]、[-11. 7%,13. 2%]和[-11. 6%,12. 2%]。通过专项质控工作,保障区域O3监测数据质量明显提升,能够为夏季重大活动保障提供更为准确、可比的O3监测数据支持。  相似文献   
169.
2003年我国十大极端天气气候事件   总被引:1,自引:0,他引:1  
陈峪  王凌  祝昌汉  张强 《灾害学》2004,19(3):76-80
2003年我国极端天气气候事件及气象灾害发生较为频繁,特别是淮河流域特大洪水、南方持续的高温热浪及伏秋连旱,造成了严重影响.另外,低温阴雨、秋汛、台风、局地暴雨等也较为突出.本文利用我中心气候业务系统所得资料,对2003年我国极端天气气候事件作一综合评述.  相似文献   
170.
基于TCT的平面交叉口安全评价方法研究   总被引:4,自引:5,他引:4  
事故率法是评价平面交叉口交通安全水平常用的方法之一,但因其存在基于事故统计方法固有的因事故的稀有性而使评价周期过长、因事故统计的不完全性致使评价结论欠真、缺乏事故严重性程度的考虑等缺点。笔者针对事故率法评价交叉口安全水平存在的上述问题,在概要介绍交通冲突技术并对交通冲突技术的有效性进行分析的基础上,提出了使事故率法与交通冲突技术相结合,用交通冲突代替交通事故改善交叉口事故率法的理论设想。进而,结合质量控制法,研究了同类型交叉口的交通冲突率的临界值的确定,提出了基于交通冲突技术和交叉口交通冲突率的评价方法。  相似文献   
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