Navigating institutional pressure in state-socialist and democratic regimes: The case of movement brontosaurus

Using the case of Movement Brontosaurus, a Czech organization founded in state socialist times, this article investigates how civic associations and nongovernmental organizations seeking to promote alternatives to the status quo respond to institutional pressures in different political and social contexts. The case shows that under state socialism, Brontosaurus appeared to conform to state mandates and societal expectations. However, its formal structure was decoupled from many activities to obscure its oppositional intent.After the transition to democracy, the organization was only able to maintain its place in society after it aligned its structure and practices with each other and openly expressed its alternative agenda. The findings demonstrate how social change and alternative lifestyle organizations vary their responses to institutional pressure in ways that enable them to realize their values and pursue their missions while accounting for the political and social contexts in which they are embedded

Protein-Engineered Proteinase of Myeloblastosis Associated Virus, An Enzyme of High Activity and HIV-1 Proteinase-Like Specificity

All proteinases of avian and mammalian retroviruses belong to the family of aspartic proteinases, are of similar size and of homologous primary structure; they all act catalytically in the form of highly symmetric molecular dimers.1 Detailed studies of retroviral proteinases were carried out on two almost identical proteinases of MAV2,3 and RS V4 (representing the group of avian retroviruses) and on the HIV proteinase.5,6 The knowledge of the 3D structure,2,4,5 catalytic activity and substrate specifity3,6 of the MAV and the HIV proteinase has changed the notion of their general similarity since several features that distinguish each proteinase from the other were revealed. The HIV-1 proteinase has a considerably higher activity3,6 which reflects the different conditions of the expression and action of this enzyme in vivo: 7 The “coding strategy” of MAV allows the expression of the proteinase from the first (gag) open reading frame and provides for the high (i.e. stoichiometrical) level of the relatively “weak” enzyme whereas the smaller amount of the more active HIV enzyme is a result of infrequent translational frameshift events that occur in the overlapping region of the gag and pol reading frames.8 The substrate specificities of retroviral proteinases seem complex and the requirement for a side chain in an individual subsite of a substrate is an outcome of the combination of residues occupying other closely located subsites.3 The two proteinases (MAV and HIV) show rather promiscuous substrate specificity, nevertheless several differences can be traced. We made an attempt to use protein engineering of the MAV proteinase to tackle directly problems of structural basis of these differences and, vice versa, to make more precise conclusions on the functional importance of the individual elements of its three dimensional structure. This article describes mutation of the MAV proteinase which resulted not only in an alteration of its substrate specificity but also in an increase of its enzymic activity — a rare case in protein engineering

Review of classifier combination methods

Summary. Classifier combination methods have proved to be an effective tool to increase the performance of pattern recognition applications. In this chapter we review and categorize major advancements in this field. Despite a significant number of publications describing successful classifier combination implementations, the theoretical basis is still missing and achieved improvements are inconsistent. By introducing different categories of classifier combinations in this review we attempt to put forward more specific directions for future theoretical research. We also introduce a retraining effect and effects of locality based training as important properties of classifier combinations. Such effects have significant influence on the performance of combinations, and their study is necessary for complete theoretical understanding of combination algorithms.