共查询到20条相似文献,搜索用时 141 毫秒
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Helena Nordström Källström Magnus Ljung 《Ambio-人类环境杂志》2005,34(4):370-376
社会层面在农业一食品系统的可持续发展中占中心地位.如果农民对他们的现状不满意或者丧失了继续从事农业的动力,那么现有的很多环境目标将不可能实现.在1997~2003年间,对社会可持续性、认可在农业系统中的重要性、行为者之间逐渐增加的合作的潜在作用进行了一些案例研究.研究的主要假定是,不断增加的社会认可是可持续社会环境的基础.我们的研究结果表明,现在许多农民认为他们社会地位低下.他们认为自己缺乏对决策的控制权,因而制约了他们继续从事农业生产的能力.公众对他们的印象和政治决策的制定过程都显得缺乏对农民技巧和知识的尊敬.但是,行为者之间日增曾的合作被认为是重大的进步,因为它创造了一个强大的关系网,给农民以一个较强势的身份.我们发现,在社会生态可持续性的合作学习和决策制定过程中最重要的是,农民需要官方和其它组织的支持、提供帮助,这样该过程才会更容易完成. 相似文献
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Rebeca B. Rosengaus James F. A. Traniello Tammy Chen Julie J. Brown Richard D. Karp 《Die Naturwissenschaften》1999,86(12):588-591
Although pathogens appear to have exerted significant selective pressure on various aspects of sociality, mechanisms of disease
resistance in the social insects are poorly understood. We report here on an immune response to infection by the dampwood
termite, Zootermopsis angusticollis. Nymphs immunized with an injection of 7.6×107, 7.6×105, or 7.6×104 cells/ml glutaraldehyde-killed solution of the bacterium Pseudomonas aeruginosa had significantly higher survivorship than controls following a challenge with a lethal concentration of active bacteria.
Similarly, nymphs exposed to a 9×10–1 spores/ml suspension of the fungus Metarhizium anisopliae had higher survivorship than controls after a challenge with a lethal concentration of spores. Prior exposure to a pathogen
thus conferred upon termites a degree of protection during a subsequent encounter with the same pathogen. This represents
the first demonstration of immune function in vivo in a social insect.
Received: 18 May 1999 / Accepted in revised form: 26 August 1999 相似文献
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Turillazzi S Sledge MF Dani FR Cervo R Massolo A Fondelli L 《Die Naturwissenschaften》2000,87(4):172-176
Obligate social parasites in the social insects have lost the worker caste and the ability to establish nests. As a result,
parasites must usurp a host nest, overcome the host recognition system, and depend on the host workers to rear their offspring.
We analysed cuticular hydrocarbon profiles of live parasite females of the paper wasp social parasite Polistes sulcifer before and after usurpation of host nests, using the non-destructive technique of solid-phase micro-extraction. Our results
reveal that hydrocarbon profiles of parasites change after usurpation of host nests to match the cuticular profile of the
host species. Chemical evidence further shows that the parasite queen changes the odour of the nest by the addition of a parasite-specific
hydrocarbon. We discuss the possible role of this in the recognition and acceptance of the parasite and its offspring in the
host colony.
Received: 18 November 1999 / Accepted in revised form: 22 December 1999 相似文献
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陈丹 《防灾科技学院学报》2009,11(2):114-116,127
突发灾害事件的处置将是我国长期面临的一项重大课题,如何对其予以健全和强化社会控制是一个亟待加强的研究视角.本文从探讨社会控制的一般理论入手,重点解析突发灾害事件中如何进行社会控制,在此基础上剖析当前我国突发灾害事件社会控制的主要问题,并有针对性地提出政策建议. 相似文献
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王新民 《防灾科技学院学报》2005,7(2):75-77
本文认为,民族精神的社会功能主要体现在三个方面。首先,民族精神在促进政治变革、维护政治稳定、促进祖国统一、抵御外来侵略、战胜自然灾害、维护民族的国际政治地位等方面具有十分重要的政治功能;其次,民族精神在促进经济发展、保障经济安全、对经济发展进行价值引导等方面,具有日益重要的经济功能;最后,民族精神在保证民族文化的传承、促进民族文化的创新和维护民族文化的安全和独立等方面,具有日益重要的文化功能。 相似文献