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191.
An arms race in space among the major powers would be immensely dangerous,destabilizing,and expensive.Russia,which has a long history in space technology dating back to Sputnik in 1957,does not have the resources or the political will to sustain such a race today.But China and the United States do.  相似文献   
192.
A decaying cadaver emits volatile organic compounds that are used by necrophilous and necrophagous insects in order to find their brood substrate. Although volatile organic compounds (VOCs) that are released by carcasses have been identified, little is known about the specific compounds that are used by these insects while searching for a brood substrate. Therefore, we have investigated the chemical ecology involved in the attraction of the necrophagous hide beetle Dermestes maculatus, which feeds as an adult and larva upon decomposing carcasses. Our aims have been to identify the responsible compounds in the odours of the carcass that are important for the attraction of the beetles. Furthermore, we have studied sex- and age-related differences in beetle attraction and tested whether the hide beetle can distinguish between various stages of decomposition by means of the emitted odours. Headspace collection of volatiles released from piglet carcasses (bloated stage, post-bloating stage, advanced decay and dry remains), coupled gas chromatography-mass spectrometry (GC-MS), gas chromatography with electroantennographic detection (GC-EAD) and bioassays were conducted to identify the volatiles responsible for the attraction of the beetles. Freshly emerged male beetles were attracted by the odour of piglets in the post-bloating stage (9 days after death; T(mean) = 27 °C) and the EAD-active compound benzyl butyrate. Statistical analysis revealed a higher relative proportion of benzyl butyrate in the odour bouquet of the post-bloating stage in comparison with the other stages. We therefore conclude that this compound plays an important role in the attraction of hide beetles to carcass odour. This underlines the potential use of D. maculatus for the estimation of the post mortem interval. The decomposition stage at which the female beetles are attracted to the odour of a cadaver remains unknown, as does the nature of this attraction. Pheromones (sexual or aggregation pheromones) might play an essential role correlated with their attraction to carrion and consequently with their attraction to the substrate for mating and ovipositioning.  相似文献   
193.
Building and extending on research on uncertainty management and voice and no-voice procedures, we examine how real personal uncertainty moderates the way in which people react to getting or being denied an opportunity to voice one??s opinions about decisions to be made. Specifically, results of two experiments show that conditions in which participants receive task-related feedback that induces personal uncertainty (versus conditions that produce more personal certainty) lead to stronger effects of voice and especially no-voice procedures on participants?? procedural fairness judgments (Experiments 1 and 2). Findings also reveal that in these conditions stronger effects of voice and particularly no-voice procedures can be found on participants?? anger about the way they have been treated, especially when participants are predisposed to react in intense terms to affect-related events (Experiment 2). Implications for the literature on uncertainty management and the social psychology of voice and no-voice procedures are discussed.  相似文献   
194.
195.
Although some research suggests that schools can be a source of protective factors for students, the processes by which school environments impact students’ behavior, performance and adjustment over time are not clear. Guided by both self-determination theory and hope theory, this article evaluated reciprocal effects among adolescent perceptions of the school environment, engagement in learning, hope, and academic achievement. Using a sample of 423 students (M age 15.72 years; 46.7% female; 77.6% white; 30.9% eligible for FRPL) from five small secondary schools in the upper Midwest, students’ perceptions of the school environment were linked to engagement in learning, which, in turn, was linked to change in academic achievement and hope over the span of 1 year. Evidence was found for reciprocal links between earlier levels of engagement and hope and later perceptions of the environment. These results suggest that the school environment represents a potential leverage point for educational reform, and interventions that target students’ perceptions of autonomy, teacher/peer support, and goal orientation may be able to promote engagement, hope, and academic achievement. In addition, such changes may create a positive feedback loop in which change in academic performance and adjustment accelerate over time.  相似文献   
196.
The Sri Lanka National Archives (SLNA) in Colombo preserve under the names of head thombo and land thombo several hundreds of eighteenth-century registers on family composition and landownership. At the time of their compilation by the Dutch East India Company or VOC the thombos suited a general administrative purpose; currently they are used only in genealogical research and in court cases concerning land disputes. Demographic, family and colonial history, however, can profit considerably from this neglected source. In the following we describe a project to digitize the registers of the Colombo province, and we discuss and evaluate the variables in the database by focusing on the family groups of a relatively small district.  相似文献   
197.
In this paper, we first deal with the rationale of risk adjustment and risk equalization in health insurance markets. Then we discuss the state of the art concerning the application of risk adjustment and risk equalization in practice. Finally, we focus on: What needs to be done?  相似文献   
198.
199.
Traditionally considered as selfish usurpers of the nation's will on the eve of the Revolution, members of the Ancien Régime parlements resorted to a falsely pre-revolutionary language has long convinced historians in their interpretations. Beyond the semantics associated with the remonstrance – a genre that is suggested here –, this paper wishes to re-insert the parliamentary dialectics against these arbitrary orders of the years 1787–88 into a broader socio-cultural field. Our aim is to show that what was at stake when dealing with the ‘sealed’ letters hinged around power and contestation within the public opinion expressed through various speeches in the Paris and provincial parliaments. The unanimous questioning of these lettres de cachet obviously concealed numerous differences and often illustrated confusion between the pre-revolutionary intentions, as expressed in leaflets, and the parliamentary speeches strongly intent on defending identity privileges. The parlements were, however, the driving force of the campaign against lettres de cachet and thus introduced the French people to what we can call rather a grammar of resistance. If they were the object of general denunciation right from the calling of the Etats généraux in July 1788 as if they had betrayed the Nation, this was because the French people were at the same time experiencing events that suddenly altered their identity along with their contesting of absolutism.  相似文献   
200.
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