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971.
The adage that “it is always easier to fight the last war” is one that readily can be applied to the United States and its armed forces for not predicting the scale and type of operations encountered in the occupations of Iraq and Afghanistan. This article argues that the lack of preparation in the post-invasion phases arose from an institutional attachment to a preferred paradigm of warfare, as exemplified by the Persian Gulf War of 1991. This paradigm, though, has been substantially resurrected and re-configured to suit the fighting preferences of the American armed forces in its protracted encounters in Iraq and Afghanistan. Far from re-orienting its organization and mindset to meet the challenges of so-called counterinsurgency campaigns, as much current advocacy maintains, the military has reverted to the form of warfare it knows best. 相似文献
972.
Rögnvaldur Hannesson 《The Review of International Organizations》2010,5(4):461-474
It is analyzed how size differences among countries affect the benefits from climate coalitions. It is shown that size differences lead to smaller coalitions and greater benefits than coalitions among identical countries. The importance of trigger strategies for supporting cooperative solutions is considered. A real world example, based on the world’s six largest emitters, is used to illustrate the implications of size differences in terms of emissions versus valuations of benefits. Climate coalitions become smaller when ranking in terms of benefits is different from ranking in terms of emissions. Three cases of benefit valuations are considered: benefits equal (i) share in world emissions, (ii) share in world GDP, and (iii) share of world population. 相似文献
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978.
Abstract This paper analyses work, childcare, and earnings of mothers in the slums of Guatemala City and Accra. Similar factors affect decisions to work and to use formal daycare, but the importance of childcare varies with the role of the formal labour sector. In Guatemala, where formal sector work is important, higher prices for informal care increase formal daycare use. However, daycare prices and proximity to daycare centers do not significantly affect earnings in Guatemala City and Accra, respectively. Providing formal daycare may be more important to mothers' decision to work in cities where formal sector work dominates. 相似文献
979.
Gottfredson and Hirschi's (1990) A General Theory of Crime has sparked a great deal of theoretical debate and empirical investigation. Tests of the theory have focused on measuring the core element, the latent trait of self‐control. The majority of this research has used the 24‐item scale developed by Grasmick et al. (1993), and a great deal of attention has been directed at the validity of this scale. Empirical debate revolves around the unidimensionality of the scale as established using conventional factor analytic techniques [exploratory factor analysis (EFA) and confirmatory factor analysis (CFA)]. In this paper, we provide the first application of an item response theory (IRT) Rasch model to the validation of the Grasmick et al. scale. IRT models focus on the interaction between the human subject and survey items, and the extent to which cumulative scales fail to provide fundamental measurement. Our results suggest that although conventional factor analyses yield results similar to those previously reported, IRT analysis reveals that one's level of self‐control influences self‐report responses, a finding consistent with Hirschi and Gottfredson. 相似文献
980.
目的探讨低氧、氧化应激中一氧化氮(NO)和氧自由基之间关系及其对培养神经元的损伤机理。方法对培养的新生大鼠神经细胞分别进行低氧、H2O2氧化应激处理和超氧化物歧化酶(SOD)抗氧化应激处理,用比色法等检测培养上清液中NO、丙二醛(MDA)、乳酸脱氢酶(LDH)和SOD含量变化指标。结果与对照组比较,低氧组和H2O2组的NO、LDH、MDA含量均显著增高,SOD含量显著降低,NO与SOD含量变化呈负相关关系。预先给予终浓度为200U/ml的SOD处理,可使神经细胞的NO、LDH和MDA释放量明显减少。各组间NO含量与LDH、MDA含量呈正相关关系。结论低氧、氧化应激促使神经元NO产生增多,NO有增加氧自由基对神经细胞的损伤作用。SOD具有清除氧自由基和减轻NO对神经元的损伤作用。 相似文献