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191.
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Book reviews     
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193.
The stability of outcomes under democratic decision-making is a significant issue in public choice. Several factors might make U.N. voting blocs less stable than blocs in national legislatures. Nevertheless, the data suggest that from 1946 to 1973 United Nations voting blocs were relatively stable. Nations that leave their blocs tend to vote with nearby blocs rather than making large ideological shifts, and tend to return to their old blocs. There does not appear to be cycles in United Nations voting blocs. Furthermore, the blocs can be ranked on a stable single-dimensioned continuum, lending further evidence that United Nations voting blocs are stable.  相似文献   
194.
Without the imposition of some institutional structure, a legislature is a non-exclusive resource, and legislators will have a tendency to overuse the resource and reduce its productivity. The committee system is a method for granting property rights over the legislature's agenda by subdividing the agenda and assigning each committee rights over a portion of the agenda. Just as common grazing ground could be more productive if it were subdivided and assigned to individual owners, the legislature is more productive if access to the agenda is subdivided and assigned to committees.Ownership rights to committee assignments are allocated based on seniority because this makes the rights more secure and therefore more valuable to their owners. In the United States Congress, the seniority rule replaced a system in which assignments were made at the discretion of party leaders. In the former system, legislators needed to expend effort to retain their assignments, which diminished their ability to use their assignments productively. Because individuals can use resources more productively if they do not have to be concerned about protecting their ownership interest, the seniority system enables the legislature to be more productive in producing legislation.  相似文献   
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The mass spectrum of the drug of abuse 2,5-dimethoxyamphetamine (2,5-DMA) is characterized by an imine fragment base peak at m/z 44 and additional fragments at m/z 151/152 for the dimethoxybenzyl cation and radical cation, respectively. Five positional ring isomers of dimethoxyamphetamines (DMA) have an isomeric relationship to 2,5-DMA. All six compounds have the same molecular weight and produce similar EI mass spectra. This lack of mass spectral specificity for the isomers in addition to the possibility of chromatographic coelution could result in misidentification. The lack of reference materials for the potential imposter molecules constitutes a significant analytical challenge. Perfluoroacylation of the amine group reduced the nitrogen basicity and provided individual fragmentation pathways for discrimination between these compounds based on some unique fragment ions and the relative abundance of common ions. GC–IRD studies provided additional structure–IR spectra relationships and yielded confirmation level identification for each of the six regioisomeric dimethoxyamphetamines. The amines and their perfluoroacylated derivatives were resolved by capillary gas chromatography and the amines showed excellent resolution on the more polar stationary phase, Rtx-200.  相似文献   
198.
A series of side chain regioisomers of 3-methoxy-4-methyl- and 4-methoxy-4-methyl-phenethylamines have mass spectra essentially equivalent to the controlled drug substance 3,4-methylenedioxymethamphetamine (3,4-MDMA), all have molecular weight of 193 and major fragment ions in their electron ionization mass spectra at m/z 58 and 135/136. The acetyl, propionyl and trifluoroacetyl derivatives of the primary and secondary regioisomeric amines were prepared and evaluated in GC-MS studies. The mass spectra for these derivatives were significantly individualized and the resulting unique fragment ions allowed for specific side chain identification. The trifluoroacetyl derivatives provided more fragment ions for molecular individualization among these regioisomeric substances. These trifluoroacetyl derivatives showed excellent resolution on a non-polar stationary phase such as Rtx-1.  相似文献   
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We propose a revised conceptual basis for the economic torts which is true to their historical role of regulating the competitive process. Claims that the economic torts are part of a wider principle of prima facie liability for intentional harm or that they are based on a theory of secondary or accessorial liability should, we argue, be rejected. Instead, we focus on a narrower and, we claim, more defensible conception of these torts in terms of the economic interests which they protect, the kinds of interferences which trigger liability, and the nature of the justifications which should be accepted as defences.  相似文献   
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This viewpoint summarises the key research themes from “The Listening Zones of NGOs” research project, that brought together NGO practitioners, language practitioners and academics from a number of disciplines. The research found that paying close attention to languages contributes to successful development programmes, according to the staff of both international and national NGOs. However, the general shift towards an emphasis on technical and thematic expertise among many INGOs has led to the risk that contextual knowledge and the resourcing of language and cultural understanding are not given priority. For INGOs, listening to the competing voices of multiple actors and organisations presents major challenges. The viewpoint presents ways of addressing those challenges.  相似文献   
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