Paradigms of frustration in superionic solid electrolytes

Superionic solid electrolytes have widespread use in energy devices, but the fundamental motivations for fast ion conduction are often elusive. In this Perspective, we draw upon atomistic simulations of a wide range of superionic conductors to illustrate some ways frustration can lower diffusion cation barriers in solids. Based on our studies of halides, oxides, sulfides and hydroborates and a survey of published reports, we classify three types of frustration that create competition between different local atomic preferences, thereby flattening the diffusive energy landscape. These include chemical frustration, which derives from competing factors in the anion–cation interaction; structural frustration, which arises from lattice arrangements that induce site distortion or prevent cation ordering; and dynamical frustration, which is associated with temporary fluctuations in the energy landscape due to anion reorientation or cation reconfiguration. For each class of frustration, we provide detailed simulation analyses of various materials to show how ion mobility is facilitated, resulting in stabilizing factors that are both entropic and enthalpic in origin. We propose the use of these categories as a general construct for classifying frustration in superionic conductors and discuss implications for future development of suitable descriptors and improvement strategies. This article is part of the Theo Murphy meeting issue ‘Understanding fast-ion conduction in solid electrolytes’.

Segmental Volatility in Ethnically Divided Societies: (Re)assessing Party System Stability in Southeast Europe

This article examines the role of ethnicity and ethnic parties as stabilizing factors in Southeast European party systems. It compares two ethnically divided countries in Southeast Europe: Bosnia and Herzegovina, where ethnic identities that form the political cleavage are firm, and Montenegro, where they are malleable. Theoretically, it addresses the debate between scholars who either find stability or instability in East European post-communist party systems. The article traces the role of ethnicity in the formation and development of electoral contests and compares the two cases by utilizing measures of block volatility, based on analysis of official electoral data. We argue that party systems in ethnically diverse countries are stable at the subsystems level, but unstable within them. In BiH, firm ethnic identity stabilizes the party system by limiting competition between blocks, leading to closure. Malleable ethnic identity in Montenegro opens competition to non-ethnic parties seeking to bridge ethnic divisions, leading to more instability. We find that party system dynamics in ethnically divided new democracies depend on identity rigidity and cleavage salience, in addition to levels of heterogeneity.

Not So Dead Genes—Retrocopies as Regulators of Their Disease-Related Progenitors and Hosts

Retroposition is RNA-based gene duplication leading to the creation of single exon nonfunctional copies. Nevertheless, over time, many of these duplicates acquire transcriptional capabilities. In human in most cases, these so-called retrogenes do not code for proteins but function as regulatory long noncoding RNAs (lncRNAs). The mechanisms by which they can regulate other genes include microRNA sponging, modulation of alternative splicing, epigenetic regulation and competition for stabilizing factors, among others. Here, we summarize recent findings related to lncRNAs originating from retrocopies that are involved in human diseases such as cancer and neurodegenerative, mental or cardiovascular disorders. Special attention is given to retrocopies that regulate their progenitors or host genes. Presented evidence from the literature and our bioinformatics analyses demonstrates that these retrocopies, often described as unimportant pseudogenes, are significant players in the cell’s molecular machinery.

Who Survives and Who Does Not? The Rise and Decline of Personalized Parties

The analysis of parties created around charismatic leaders is becoming more important in dynamic times when the mainstream parties are challenged by outsiders. Most of the research on personalized parties focuses on Western Europe although the phenomenon has significant implications for East European party systems. This article examines the development of two highly electorally successful personalized parties in Bulgaria: National Movement Simeon the Second (NDSV) and Citizens for European Development of Bulgaria (GERB), the incumbent ruling party. Their similar success but different paths of development provide a good basis for examining the stabilizing factors of personalized parties. The article fills a gap in the theoretical field by using information from qualitative interviews with high-level party members and proves that adoption of an organizational strategy is the key factor for survival. Examining a case of the emergence of personalized parties, the research finds that alongside charismatic leaders, investment in local branches and representation in localities are stabilizing factors when the popularity of the leader decreases and in this way secure the more stable development of the party.

ECONOMIC FLUCTUATIONS AND THE SHADOW ECONOMY: A GLOBAL STUDY

The recent economic crisis re-emphasizes the importance of the economic fluctuations. This study investigates the role of shadow economy in combination with economic factors on the economic instability for 133 economies between 1991 and 2015. Using the system-GMM estimations, this paper shows that a larger shadow economy increases the fluctuations of GDP growth rate in relation to the size and the volatility of shadow economy. Notably, the shadow economy presents an inverted-U relationship with economic instability and this relationship is strongest for low- and lower-middle income economies. Our results identify two categories of drivers for economic fluctuations: the stabilizing factors (the labor force and the TFP) and the enhancing factors (capital investment, consumption, government spending, trade, and FDI inflows). Interestingly, exports increase economic fluctuations while imports decrease them. Finally, we discuss the differences in the determinants of economic instability across low, middle and high incomes countries. This study documented that shadow economy influences the economic fluctuations — our results actually confirm our hypothesis and the impact of shadow economy on the effectiveness of macroeconomic policies. The contribution of this paper is to show the extent to which the impact can affect the economic activities and how institutions can smooth this effect.

Inequality and Instability in the Time of COVID-19

Many past crises—including the 1918 pandemic and the two world wars—helped to level social and economic inequality. But as extreme as the reaction has been to COVID-19, it may not be enough to prompt similar change. Stabilizing factors in the economy hinder the kind of socioeconomic reform that some desire. So far, the crisis has only increased inequality between the advantaged and disadvantaged.

Economic Fluctuations and the shadow Economy: A global study

The recent economic crisis re-emphasizes the importance of the economic fluctuations. This study investigates the role of shadow economy in combination with economic factors on the economic instability for 133 economies between 1991 and 2015. Using the system-GMM estimations, this article shows that a larger shadow economy increases the fluctuations of GDP growth rate in relation to the size and the volatility of shadow economy. Notably, the shadow economy presents an inverted-U relationship with economic instability and this relationship is strongest for low- and lower-middle income economies. Our results identify two categories of drivers for economic fluctuations: the stabilizing factors (the labour force and the TFP) and the enhancing factors (capital investment, consumption, government spending, trade and FDI inflows). Interestingly exports increase economic fluctuations while imports decrease them. Finally, we discuss differences in the determinants of economic instability across low, middle and high incomes countries.