Evolution of histone 2A for chromatin compaction in eukaryotes.

During eukaryotic evolution, genome size has increased disproportionately to nuclear volume, necessitating greater degrees of chromatin compaction in higher eukaryotes, which have evolved several mechanisms for genome compaction. However, it is unknown whether histones themselves have evolved to regulate chromatin compaction. Analysis of histone sequences from 160 eukaryotes revealed that the H2A N-terminus has systematically acquired arginines as genomes expanded. Insertion of arginines into their evolutionarily conserved position in H2A of a small-genome organism increased linear compaction by as much as 40%, while their absence markedly diminished compaction in cells with large genomes. This effect was recapitulated in vitro with nucleosomal arrays using unmodified histones, indicating that the H2A N-terminus directly modulates the chromatin fiber likely through intra- and inter-nucleosomal arginine-DNA contacts to enable tighter nucleosomal packing. Our findings reveal a novel evolutionary mechanism for regulation of chromatin compaction and may explain the frequent mutations of the H2A N-terminus in cancer

Microfoundations of organizational paradox: The problem is how we think about the problem

Competing tensions and demands pervade our work lives. Accumulating research examines organizational and leadership approaches to leveraging these tensions. But what about individuals within firms? Although early paradox theory built upon micro-level insights from psychology and philosophy to understand the nature and management of varied competing demands, corresponding empirical studies are rare, offering scarce insights into why some individuals thrive with tensions while others struggle. In response, we contribute to the microfoundations of organizational paradox with a theoretical model and robust measures that help unpack individuals' varied approaches to tensions. Following rigorous scale development in Study 1, including samples from the US, UK, Israel, and China, we test our model in a large firm in the US using quantitative and qualitative methods. We identify resource scarcity (i.e. limited time and funding) as a source of tensions. We also demonstrate that a paradox mindset - the extent to which one is accepting of and energized by tensions - can help individuals leverage them to improve in-role job performance and innovation. Our results highlight paradox mindset as a key to unlocking the potential of everyday tensions

CITIZENSHIP IN THE STRUCTURE OF SOCIO-POLITICAL ORIENTATIONS OF RUSSIAN YOUTH: PLACE AND ROLE IN STATEHOOD STRENGTHENING

Purpose of the study: In this study, we analyze citizenship in the structure of socio-political orientations of Russian youth and explore the youth role in strengthening statehood and formation of civil society institutions. The development of active citizenship values in sociopolitical orientations of Russian youth is determined by the need to change relations between the state and society. The citizens shall develop civic responsibility and civil initiatives and control the institutions of power. Methodology: The theory of social anomie and the concept of socio-cultural crisis serve the methodological basis for this study. This theory explores the eclectic nature of citizenship ideas in the youth environment. The civilizational approach makes it possible to investigate features of citizenship idea and practice information of Western European and Russian cultural traditions. All that is methodologically significant in tracking citizenship specificity of the Russian youth. The integrated approach becomes a conceptual one in this study as it treats the citizenship of Russian youth as a complex multi-component phenomenon. This phenomenon includes moral, legal and socio-political attitudes reflecting the various aspects of relations in the "man-society-state" system. Results: We conclude that in the citizenship of Russian youth there dominate two main attitudes: liberal and paternalistic. In the liberal aspect, the young people consider citizenship to be awareness of their civil rights and responsibilities, a kind of rational and active behavior corresponding to democratic political system. Paternalistic attitudes are manifested in loyalty to the state. Paternalists consider the state to be the political institution that is solely responsible for the present and future of the young people. Applications of this study: The results allow us to understand the significance of citizenship as an ethic-legal quality of personality that strengthens Russian statehood and the importance of agreement (contract) between government and society. The results discovered the need for the citizens to be engaged in solving the state's socially significant problems. The state shall also develop a favorable institutional environment for civil socialization and self-realization of the young people. Novelty/Originality of this study: The eclectic nature of Russian youth citizenship points at hindering factors in the development of active and responsible citizenship as the youth ability to self-organize and solve socially significant problems. The main factors hindering the process of civil activity formation among the young people are the stable etatist-paternalistic traditions of political culture and institutions of Russian civil society. Although, development of youth citizenship is a well-managed process. It requires the youth policy to be the stimulating and guiding force. This force is necessary to solve the problems of legal personality type formation. Such a personality is characterized by politically and socially active civic-mindedness

Absolute and relative stability of loss aversion across contexts

Individuals’ decisions under risk tend to be in line with the notion that “losses loom larger than gains”. This loss aversion in decision making is commonly understood as a stable in- dividual preference that is manifested across different contexts. The presumed stability and generality, which underlies the prominence of loss aversion in the literature at large, has been recently questioned by studies reporting how loss aversion can disappear, and even reverse, as a function of the choice context. The present study investigated whether loss aversion reflects a trait-like attitude of avoiding losses or rather individuals’ adaptability to different contexts. We report three experiments investigating the within-subject context sensitivity of loss aversion in a two-alternative forced-choice task. Our results show that the choice context can shift people’s loss aversion, though somewhat inconsistently. Moreover, individual estimates of loss aversion are shown to have a considerable degree of stability. Altogether, these results indicate that even though the absolute value of loss aversion can be affected by external factors such as the choice context, estimates of people’s loss aversion still capture the relative dispositions towards gains and losses across individuals

Multi-Exciton Spectroscopy of a Single Self Assembled Quantum Dot

We apply low temperature confocal optical microscopy to spatially resolve, and spectroscopically study a single self assembled quantum dot. By comparing the emission spectra obtained at various excitation levels to a theoretical many body model, we show that: Single exciton radiative recombination is very weak. Sharp spectral lines are due to optical transitions between confined multiexcitonic states among which excitons thermalize within their lifetime. Once these few states are fully occupied, broad bands appear due to transitions between states which contain continuum electrons.Comment: 12 pages, 4 figures, submitted for publication on Jan,28 199

LIF Measurements of the Cylindrical Hall Thruster Plume

This paper presents a Laser Induced Fluorescence (LIF) investigation of ion velocity profiles in the plume of the Fully Cylindrical Hall Thruster (FCHT) recently developed at the Princeton Plasma Physics Laboratory. These measurements confirm a previously measured ∼ 7% increase in the exhaust velocity when the cathode keeper draws an excess current (overrun mode). Furthermore, it was found that velocity directions in the plume remain relatively unchanged for the cusped and direct magnetic field configuration in both overrun and non-overrun modes. It is shown that the reported plume narrowing in the overrun mode is due to the shift of the acceleration and ionization regions inward toward the anode. This conclusion is supported by the potential profiles extracted from the LIF measurements, which indicate that in the overrun mode a larger fraction of potential fall occurs inside the thruster. Recent probe measurements further substantiate these findings [Raitses et al. , Phys. Plasma 16, 057106 (2009)]. The ratio of the potential fall experienced by ions inside the thruster over the actual potential drop within the thruster increases from 20% in the non-overrun regime with magnets in the direct configuration to 70% in the overrun mode with magnets in the cusped configuration. Magnetic field lines outside the thruster channel are found to be not equipotential, with the degree of equipotentiality gradually increasing at the thruster exit toward the edge

Middle ground approach to paradox: Within- and between-culture examination of the creative benefits of paradoxical frames

The authors contributed equally to this work.</p

Confined combustion of TNT explosion products in air

Effects of turbulent combustion induced by explosion of a 0.8 kg cylindrical charge of TNT in a 17 m3 chamber filled with air, are investigated. The detonation wave in the charge transforms the solid explosive (C7H5N3O6) to gaseous products, rich (~20% each) in carbon dust and carbon monoxide. The detonation pressure (~210 kb) thereby engendered causes the products to expand rapidly, driving a blast wave into the surrounding air. The interface between the products and air, being essentially unstable as a consequence of strong acceleration to which it is subjected within the blast wave, evolves into a turbulent mixing layer-a process enhanced by shock reflections from the walls. Under such circumstances rapid combustion takes place where the expanded detonation products play the role of fuel. Its dynamic effect is manifested by the experimental measurement of ~3 bar pressure increase in the chamber, in contrast to ~1bar attained by a corresponding TNT explosion in nitrogen. The experiments were modeled as a turbulent combustion in an unmixed system at infinite Reynolds, Peclet and DamkGhler numbers. The CFD solution was obtained by a high-order Godunov scheme using an AMR (Adaptive Mesh Refinement) to trace the turbulent mixing on the computational grid in as much detail as possible. The evolution of the mass fraction of fuel consumed by combustion thus determined exhibited the properties of an exponential decay following a sharp initiation. The results reveal all the dynamic features of the exothermic process of combustion controlled by fluid mechanic transport in a highly turbulent field, in contrast to those elucidated by the conventional reaction-diffusion model

Verbal extremism as a form of verbal influence on the recipient

This paper determines through the linguistic analysis the possibilities of verbal extremism aimed at manipulation with the actions and behavior of the recipient. The texts presented online in the Internet telecommunication network are investigated. The communicative attitudes to the control over the recipient's behavior, as well as the linguistic features of their implementation in the text are reveale