Fraudulent Elections, Political Protests, and Regime Transitions

This research studies protests after fraudulent elections in a collective action framework, examining the impact of the potential cost, benefit and likelihood of success of protest on the occurrence and intensity of protests. Quantitative analysis of fraudulent elections in about 100 countries from 1990 to 2004 shows that the odds of protest after fraudulent elections are greater when the level of state repression is moderate with a possible backlash effect of high repression, when the opposition is united, and when international monitors denounce election results. The analysis only partially supports the benefit of protest argument. Also, the research uses case studies from Eurasia (Armenia, Belarus, Georgia, and Russia) and mini-case studies from Africa and Latin America to study in more detail the effects of the factors identified in the quantitative analysis and to identify overlooked but important explanatory factors using a set of extensive interviews conducted in the United States and during fieldwork in Armenia, Georgia, and Russia with politicians, domestic and international election monitors, and country experts

Electromagnetic vacuum fluctuations around a cosmic string in de Sitter spacetime

The electromagnetic field correlators are evaluated around a cosmic string in background of $(D+1)$-dimensional dS spacetime assuming that the field is prepared in the Bunch-Davies vacuum state. The correlators are presented in the decomposed form where the string-induced topological parts are explicitly extracted. With this decomposition, the renormalization of the local vacuum expectation values (VEVs) in the coincidence limit is reduced to the one for dS spacetime in the absence of the cosmic string. The VEVs of the squared electric and magnetic fields, and of the vacuum energy density are investigated. Near the string they are dominated by the topological contributions and the effects induced by the background gravitational field are small. In this region, the leading terms in the topological contributions are obtained from the corresponding VEVs for a string on the Minkowski bulk multiplying by the conformal factor. At distances from the string larger than the curvature radius of the background geometry, the pure dS parts in the VEVs dominate. In this region, for spatial dimensions $D>3$, the influence of the gravitational field on the topological contributions is crucial and the corresponding behavior is essentially different from that for a cosmic string on the Minkowski bulk. There are well-motivated inflationary models which produce cosmic strings. We argue that, as a consequence of the quantum-to-classical transition of super-Hubble electromagnetic fluctuations during inflation, in the postinflationary era these strings will be surrounded by large scale stochastic magnetic fields. These fields could be among the distinctive features of the cosmic strings produced during the inflation and also of the corresponding inflationary models.Comment: 19 pages, 2 figure

Electromagnetic vacuum densities induced by a cosmic string

We investigate the influence of a generalized cosmic string in (D+1) -dimensional spacetime on the local characteristics of the electromagnetic vacuum. Two special cases are considered with flat and locally de Sitter background geometries. The topological contributions in the vacuum expectation values (VEVs) of the squared electric and magnetic fields are explicitly separated. Depending on the number of spatial dimensions and on the planar angle deficit induced by the cosmic string, these contributions can be either negative or positive. In the case of the flat bulk, the VEV of the energy-momentum tensor is evaluated as well. For the locally de Sitter bulk, the influence of the background gravitational field essentially changes the behavior of the vacuum densities at distances from the string larger than the curvature radius of the spacetime.Comment: 19 pages, 5 figures. arXiv admin note: text overlap with arXiv:1706.0074

Comprehensive review of enzyme immobilization in industry: applications, advantages, and challenges

Treballs Finals de Grau d'Enginyeria Química, Facultat de Química, Universitat de Barcelona, Curs: 2021-2022, Tutor: David Faulon MarruecosEnzymes bring lots of energetical, environmental and economic advantages that are obfuscating the vision of classical chemistry. Since enzymes are susceptible to destabilizing under industrial harsh conditions, industrial feasibility of enzyme use relies on making enzymes stronger and more active under such environments. Thus, catalytic chemistry has taken the path of conjugating enzymes with other molecules or surfaces that give new characteristics to render them more stable and, sometimes, even more active with respect to the original form. The mechanisms underlying enzyme conformational changes and their correlation with activity have yet to be unveiled, but recent research has shed some light on how intermolecular and intramolecular interactions combined with immobilization techniques govern enzyme thermodynamics and kinetics. Thus, harnessing such knowledge can potentially give us a roadmap to ensure enzyme effectiveness in ubiquitous industrial sectors, such as food and pharmaceutics. In short, enzyme immobilization can be the cornerstone that might impulse a new generation of biochemical synthesis in industry which is the greenest and most efficient ever utilized up until now