Validation of moment tensor potentials for fcc and bcc metals using EXAFS spectra

Machine-learning potentials for materials, namely the moment tensor potentials (MTPs), were validated using experimental EXAFS spectra for the first time. The MTPs for four metals (bcc W and Mo, fcc Cu and Ni) were obtained by the active learning algorithm of fitting to the results of the calculations using density functional theory (DFT). The MTP accuracy was assessed by comparing metal K-edge EXAFS spectra obtained experimentally and computed from the results of molecular dynamics (MD) simulations. The sensitivity of the method to various aspects of the MD and DFT models was demonstrated using Ni as an example. Good agreement was found for W, Mo and Cu using the recommended PAW pseudopotentials, whereas a more accurate pseudopotential with 18 valence electrons was required for Ni to achieve a similar agreement. The use of EXAFS spectra allows one to estimate the MTP ability in reproducing both average and dynamic atomic structures

MASS SURVEILLANCE AND DATA PROTECTION IN THE DIGITAL AGE

Abstract. The article considers the legitimacy of mass surveillance in the context of international human rights law and the existing mechanisms of protection of the right to respect for private life. The author notes that the problems concerning the protection of personal data of millions of people from mass surveillance should be solved both at the national and international levels. In this regard, covert surveillance is even more important in the context of the development of the Internet, as it is based on the creation of programmes and methods for monitoring the transmission of information online. Special attention is paid to data protection in global social networks, which are vulnerable and store personal data of billions of people. The article provides examples of case-law of the court of justice of the EU andthe ECtHR on the protection of personal data. Further, based on the examples of some countries, the prospects for the creation of a new international instrument for the regulation of surveillance are outlined and an attempt is made to identify the role of European countries and Russia in this process..Keywords: data protection; mass surveillance; human rights; Internet

Stereoelectronic effects in RNase-catalysed reactions of dinucleoside phosphate cleavage

AbstractThe rate at which dinucleoside phosphates are cleaved by RNases is supposed to be determined by the mole fraction of enzyme-substrate complexes in which the phosphodiester moiety of a dinucleoside phosphate has a highly reactive conformation. The mole fraction of such complexes for a particular RNase depends on the nature of a nucleoside at the O5'-end of the phosphodiester bond. Experimental data are presented to support this hypothesis

Structural and thermodynamic insight into the process of “weak” dimerization of the ErbB4 transmembrane domain by solution NMR

AbstractSpecific helix–helix interactions between the single-span transmembrane domains of receptor tyrosine kinases are believed to be important for their lateral dimerization and signal transduction. Establishing structure–function relationships requires precise structural-dynamic information about this class of biologically significant bitopic membrane proteins. ErbB4 is a ubiquitously expressed member of the HER/ErbB family of growth factor receptor tyrosine kinases that is essential for the normal development of various adult and fetal human tissues and plays a role in the pathobiology of the organism. The dimerization of the ErbB4 transmembrane domain in membrane-mimicking lipid bicelles was investigated by solution NMR. In a bicellar DMPC/DHPC environment, the ErbB4 membrane-spanning α-helices (651–678)2 form a right-handed parallel dimer through the N-terminal double GG4-like motif A655GxxGG660 in a fashion that is believed to permit proper kinase domain activation. During helix association, the dimer subunits undergo a structural adjustment (slight bending) with the formation of a network of inter-monomeric polar contacts. The quantitative analysis of the observed monomer–dimer equilibrium provides insights into the kinetics and thermodynamics of the folding process of the helical transmembrane domain in the model environment that may be directly relevant to the process that occurs in biological membranes. The lipid bicelles occupied by a single ErbB4 transmembrane domain behave as a true (“ideal”) solvent for the peptide, while multiply occupied bicelles are more similar to the ordered lipid microdomains of cellular membranes and appear to provide substantial entropic enhancement of the weak helix–helix interactions, which may be critical for membrane protein activity

Effect of Cultural Priming on Social Behavior and EEG Correlates of Self-Processing

Humans are social beings and the self is inevitably conceptualized in terms of social environment. The degree to which the self is perceived as fundamentally similar or fundamentally different from other people is modulated by cultural stereotypes, such as collectivism and individualism. These stereotypes are not hardwired in our brains and individuals differ in the degree to which they adopt the attitudes that define their culture. Moreover, individuals can acquire multiple sets of cultural knowledge and, depending on the context, either individualistic or collectivistic cultural mindset could be activated. In this study, we used cultural priming techniques to activate either individualistic or collectivistic mindset and investigated the association between source-level EEG connectivity in the default mode network (DMN) and spontaneous self-related thoughts in the subsequent resting state. Afterward, participants performed a social interaction task, in which they were allowed to choose between friendly, avoidant, or aggressive behavior. After collectivism priming, self-related thoughts were associated with increased connectivity of DMN with the right temporoparietal junction (TPJ), which is involved in taking the perspective of others and is more active in representatives of collectivistic cultures, whereas after individualism priming they were associated with increased connectivity with the temporal pole, which is involved in self/other discrimination and is more active in representatives of individualistic cultures. Individual differences in the intensity of post-priming self-related thoughts and the strength of DMN-temporal pole connectivity predicted individual differences in behavior during the social interaction task, with individualistic mindset predisposing to more friendly and trustful social behavior

Geometry of jet spaces and integrable systems

An overview of some recent results on the geometry of partial differential equations in application to integrable systems is given. Lagrangian and Hamiltonian formalism both in the free case (on the space of infinite jets) and with constraints (on a PDE) are discussed. Analogs of tangent and cotangent bundles to a differential equation are introduced and the variational Schouten bracket is defined. General theoretical constructions are illustrated by a series of examples.Comment: 54 pages; v2-v6 : minor correction

Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR

Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (mu_B > 500 MeV), effects of chiral symmetry, and the equation-of-state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2022, in the context of the worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal