Cultural identity of the individual in the context of globalization and informatization of modernity

The article is expanded need of analysis the cultural identity of the individual in terms of transformation of socio-cultural space. The influence of new information technologies, which significantly changed the idea of human identity. We consider the socio-cultural practices that are influenced by information technology. Authors determined the social consequences of conflict transformation cultural identity. On the one hand, information modernity allows the individual to design their own individual world, on the other hand, questioned the preservation of existing social relations. The findings indicated the disappearance of defined values and cultural landmarks. The necessity of new forms of self-determination rights in the destruction of their traditional way of life.Key words: identity, transformation, information technology, information space, socio-cultural practices, cultural values. Обґрунтовано необхідність аналізу культурної ідентичності особистості в умовах трансформації соціокультурного простору. Показано вплив новітніх інформаційних технологій, що істотно змінили уявлення про ідентичність людини. Розглянуто соціокультурні практики, що формуються під впливом інформаційних технологій. Означено протиріччя соціальних наслідків трансформації культурної ідентичності. З одного боку, інформаційна сучасність дозволяє індивіду конструювати свій індивідуальний світ, з іншого боку, ставить під сумнів збереження існуючих соціальних зв’язків. У висновках зазначається зникнення визначених культурних цінностей та орієнтирів. Наголошується на необхідності появи нових форм самовизначення людини в результаті руйнування звичного способу життя. Ключові слова: ідентичність, трансформація, інформаційні технології, інформаційний простір, соціокультурні практики, культурні цінності

Diagnosing numerical Cherenkov instabilities in relativistic plasma simulations based on general meshes

Numerical Cherenkov radiation (NCR) or instability is a detrimental effect frequently found in electromagnetic particle-in-cell (EM-PIC) simulations involving relativistic plasma beams. NCR is caused by spurious coupling between electromagnetic-field modes and multiple beam resonances. This coupling may result from the slow down of poorly-resolved waves due to numerical (grid) dispersion and from aliasing mechanisms. NCR has been studied in the past for finite-difference-based EM-PIC algorithms on regular (structured) meshes with rectangular elements. In this work, we extend the analysis of NCR to finite-element-based EM-PIC algorithms implemented on unstructured meshes. The influence of different mesh element shapes and mesh layouts on NCR is studied. Analytic predictions are compared against results from finite-element-based EM-PIC simulations of relativistic plasma beams on various mesh types.Comment: 31 pages, 20 figure

Caffeine inhibits hypoxia-induced nuclear accumulation in HIF-1α and promotes neonatal neuronal survival

© 2019 The Authors Apnea of prematurity (AOP) defined as cessation of breathing for 15–20 s, is commonly seen in preterm infants. Caffeine is widely used to treat AOP due to its safety and effectiveness. Caffeine releases respiratory arrest by competing with adenosine for binding to adenosine A 1 and A 2A receptors (A 1 R and A 2A R). Long before its use in treating AOP, caffeine has been used as a psychostimulant in adult brains. However, the effect of caffeine on developing brains remains unclear. We found that A 1 R proteins for caffeine binding were expressed in the brains of neonatal rodents and preterm infants (26–27 weeks). Neonatal A 1 R proteins colocalized with PSD-95, suggesting its synaptic localization. In contrast, our finding on A 2 R expression in neonatal neurons was restricted to the mRNA level as detected by single cell RT/PCR due to the lack of specific A 2A R antibody. Furthermore, caffeine (200 μM) at a dose twice higher than the clinically relevant dose (36–130 μM) had minor or no effects on several basic neuronal functions, such as neurite outgrowth, synapse formation, expression of A 1 R and transcription of CREB-1 and c-Fos, further supporting the safety of caffeine for clinical use. We found that treatment with CoCl 2 (125 μM), a hypoxia mimetic agent, for 24 h triggered neuronal death and nuclear accumulation of HIF-1α in primary neuronal cultures. Subsequent treatment with caffeine at a concentration of 100 μM alleviated CoCl 2 -induced cell death and prevented nuclear accumulation of HIF-1α. Consistently, caffeine treatment in early postnatal life of neonatal mice (P4-P7) also prevented subsequent hypoxia-induced nuclear increase of HIF-1α. Together, our data support the utility of caffeine in alleviating hypoxia-induced damages in developing neurons

Non-Maxwellian Proton Velocity Distributions in Nonradiative Shocks

The Balmer line profiles of nonradiative supernova remnant shocks provide the means to measure the post-shock proton velocity distribution. While most analyses assume a Maxwellian velocity distribution, this is unlikely to be correct. In particular, neutral atoms that pass through the shock and become ionized downstream form a nonthermal distribution similar to that of pickup ions in the solar wind. We predict the H alpha line profiles from the combination of pickup protons and the ordinary shocked protons, and we consider the extent to which this distribution could affect the shock parameters derived from H alpha profiles. The Maxwellian assumption could lead to an underestimate of shock speed by up to about 15%. The isotropization of the pickup ion population generates wave energy, and we find that for the most favorable parameters this energy could significantly heat the thermal particles. Sufficiently accurate profiles could constrain the strength and direction of the magnetic field in the shocked plasma, and we discuss the distortions from a Gaussian profile to be expected in Tycho's supernova remnant.Comment: 13 pages, 6 figure

The Link Between Shocks, Turbulence and Magnetic Reconnection in Collisionless Plasmas

Global hybrid (electron fluid, kinetic ions) and fully kinetic simulations of the magnetosphere have been used to show surprising interconnection between shocks, turbulence and magnetic reconnection. In particular collisionless shocks with their reflected ions that can get upstream before retransmission can generate previously unforeseen phenomena in the post shocked flows: (i) formation of reconnecting current sheets and magnetic islands with sizes up to tens of ion inertial length. (ii) Generation of large scale low frequency electromagnetic waves that are compressed and amplified as they cross the shock. These \u27wavefronts\u27 maintain their integrity for tens of ion cyclotron times but eventually disrupt and dissipate their energy. (iii) Rippling of the shock front, which can in turn lead to formation of fast collimated jets extending to hundreds of ion inertial lengths downstream of the shock. The jets, which have high dynamical pressure, \u27stir\u27 the downstream region, creating large scale disturbances such as vortices, sunward flows, and can trigger flux ropes along the magnetopause. This phenomenology closes the loop between shocks, turbulence and magnetic reconnection in ways previously unrealized. These interconnections appear generic for the collisionless plasmas typical of space, and are expected even at planar shocks, although they will also occur at curved shocks as occur at planets or around ejecta

Surface alignment and anchoring transitions in nematic lyotropic chromonic liquid crystal

The surface alignment of lyotropic chromonic liquid crystals (LCLCs) can be not only planar (tangential) but also homeotropic, with self-assembled aggregates perpendicular to the substrate, as demonstrated by mapping optical retardation and by three-dimensional imaging of the director field. With time, the homeotropic nematic undergoes a transition into a tangential state. The anchoring transition is discontinuous and can be described by a double-well anchoring potential with two minima corresponding to tangential and homeotropic orientation.Comment: Accepted for publication in Phys. Rev. Lett. (Accepted Wednesday Jun 02, 2010

HYPERS simulations of solar wind interactions with the Earth's magnetosphere and the Moon

The hybrid simulations, where the ions are treated kinetically and the electrons as a fluid, seek to describe ion microphysics with maximum physical fidelity. The hybrid approach addresses the fundamental need for space plasma models to incorporate physics beyond magnetohydrodynamics. Global hybrid simulations must account for a wide range of both kinetic ion and whistler/Alfvén wave spatio-temporal scales in strongly inhomogeneous plasmas. We present results from two three-dimensional hybrid simulations performed with a novel asynchronous code, HYPERS designed to overcome computational bottlenecks that typically arise in such multiscale simulations. First, we demonstrate an excellent match between simulated lunar wake profiles and observations. We also compare our simulations with two other simulations performed with conventional (time-stepped) hybrid codes. Second, we investigate the interaction of the solar wind with the Earth's dayside magnetosphere under conditions when the orientation of the interplanetary magnetic field is quasi-radial. In this high-resolution simulation we highlight three-dimensional properties of foreshock perturbations formed by the backstreaming ions

Statistical study of magnetosheath jet‐driven bow waves

When a magnetosheath jet (localized dynamic pressure enhancements) compresses ambient magnetosheath at a (relative) speed faster than the local magnetosonic speed, a bow wave or shock can form ahead of the jet. Such bow waves or shocks were recently observed to accelerate particles, thus contributing to magnetosheath heating and particle acceleration in the extended environment of Earth’s bow shock. To further understand the characteristics of jet‐driven bow waves, we perform a statistical study to examine which solar wind conditions favor their formation and whether it is common for them to accelerate particles. We identified 364 out of 2859 (~13%) magnetosheath jets to have a bow wave or shock ahead of them with Mach number typically larger than 1.1. We show that large solar wind plasma beta, weak interplanetary magnetic field (IMF) strength, large solar wind Alfvén Mach number, and strong solar wind dynamic pressure present favorable conditions for their formation. We also show that magnetosheath jets with bow waves or shocks are more frequently associated with higher maximum ion and electron energies than those without them, confirming that it is common for these structures to accelerate particles. In particular, magnetosheath jets with bow waves have electron energy flux enhanced on average by a factor of 2 compared to both those without bow waves and the ambient magnetosheath. Our study implies that magnetosheath jets can contribute to shock acceleration of particles especially for high Mach number shocks. Therefore, shock models should be generalized to include magnetosheath jets and concomitant particle acceleration