6,591 research outputs found
Security Issues in a SOA-based Provenance System
Recent work has begun exploring the characterization and utilization of provenance in systems based on the Service Oriented Architecture (such as Web Services and Grid based environments). One of the salient issues related to provenance use within any given system is its security. Provenance presents some unique security requirements of its own, which are additionally dependent on the architectural and environmental context that a provenance system operates in. We discuss the security considerations pertaining to a Service Oriented Architecture based provenance system. Concurrently, we outline possible approaches to address them
Molecular, morphological, and phytochemical evidence for a broad species concept of Plagiochila bifaria (Hepaticae)
Debate over the synonymy of the European Plagiochila killarniensis and the Neotropical P bifaria of R sect. Arrectae has focused on differences in secondary metabolite composition. The broad morphological species concept of R bifaria proposed in recent papers has now been tested by comparing nrDNA ITS1 and ITS2 sequences of R bifaria populations encompassing several different morpho- and chemotypes from the British Isles, Tenerife, Costa Rica, Brazil, Ecuador, and Bolivia, with sequences of other species of R sects. Arrectae, Rutilantes, and Fuscoluteae. Phylogenetic analyses demonstrate that specimens of P. bifaria form a well supported clade within Plagiochila sect. Arrectae. Sequences of R bifaria from the British Isles, Tenerife, and Ecuador, representing the "methyl everninate" chemotype, form a well supported subclade within the P bifaria clade. Sequences of specimens from Costa Rica, Brazil, and Bolivia are placed in the basal part of the R bifaria clade. The data support a broad species concept of P bifaria. The different chemotypes do not warrant distinct taxonomic ranks. Plagiochila centrifuga and P. compressula are treated as new synonyms of R bifaria
Rethinking the Concept of Long-Run Economic Growth
This paper argues that growth theory needs a more general “regularity” concept than that of exponential growth. This opens up for considering a richer set of parameter combinations than in standard growth models. Allowing zero population growth in the Jones (1995) model serves as our illustration of the usefulness of a general concept of “regular growth”.exponential growth; arithmetic growth; regular growth; semi-endogenous growth; knife-edge restrictions
Revolution is No Longer a One State Affair
Often the first goal of many modern revolutions is “internationalizing the conflict.’’ Yet as the recent revolutions and revolts in Egypt and Tunisia illustrate, the international system plays a powerful yet under-recognized role in these conflicts from their inception to their conclusion. Through examinations of three early 20th century revolutions, , the Young Turk Revolution (1908), the Algerian Decolonization Movement (1954-1962), and the Iranian Revolution (1979), this piece explores the significant role of the international system in creating a “context” for revolution through direct foreign involvement in a state, changes to the international opportunity structures, and the polarization of the international sphere. These studies reveal the variety of ways that the international system can influence a revolution at a level on par with, if not surpassing, domestic influences. These three revolutions were global conflicts, a condition that has far reaching implications for not just the revolutions under consideration, but all future revolutions, as our world enters the realm of (post) globalization
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