Non-Markovian dynamics with fermions

Employing the quadratic fermionic Hamiltonians for the collective and internal subsystems with a linear coupling, we studied the role of fermionic statistics on the dynamics of the collective motion. The transport coefficients are discussed as well as the associated fluctuation-dissipation relation. Due to different nature of the particles, the path to equilibrium is slightly affected. However, in the weak coupling regime, the time-scale for approaching equilibrium is found to be globally unchanged. The Pauli-blocking effect can modify the usual picture in open quantum system. In some limits, contrary to boson, this effect can strongly hinder the influence of the bath by blocking the interacting channels.Comment: 13 pages, 6 figures. Submitted to PR

Neutron pair transfer in sub-barrier capture process

The sub-barrier capture reactions following the neutron pair transfer are proposed to be used for the indirect study of neutron-neutron correlation in the surface region of nucleus. The strong effect of the dineutron-like clusters transfer stemming from the surface of magic and non-magic nuclei $^{18}$O, $^{48}$Ca, $^{64}$Ni, $^{94,96}$Mo, $^{100,102,104}$Ru, $^{104,106,108}$Pd, and $^{112,114,116,118,120,124,132}$Sn is demonstrated. The dominance of two-neutron transfer channel at the vicinity of the Coulomb barrier is further supported by time-dependent mean-field approaches.Comment: 17 pages, 7 figures, accepted in PR

Polarization of the nuclear surface in deformed nuclei

The density profiles of around 750 nuclei are analyzed using the Skyrme energy density functional theory. Among them, more than 350 nuclei are found to be deformed. In addition to rather standard properties of the density, we report a non-trivial behavior of the nuclear diffuseness as the system becomes more and more deformed. Besides the geometric effects expected in rigid body, the diffuseness acquires a rather complex behavior leading to a reduction of the diffuseness along the main axis of deformation simultaneously with an increase of the diffuseness along the other axis. The possible isospin dependence of this polarization is studied. This effect, that is systematically seen in medium- and heavy-nuclei, can affect the nuclear dynamical properties. A quantitative example is given with the fusion barrier in the $^{40}$Ca+ $^{238}$U reaction.Comment: 8 pages, 13 figure

The View of Russian Students on Whether Psychology is a Science

The Psychology as Science Scale (Friedrich, 1996) was administered to 525 psychology students from nine Russian universities to assess their beliefs about the nature of the discipline. About half of students (49.6%) generally agreed that psychology may be called a scientific discipline. Specifically, 71. 5% of the students agreed that psychology is a natural science, similar to biology, chemistry, and physics, 39. 9% of students agreed that psychological research is important and training in psychological methodology is necessary, and 43.1% of students agreed that human behavior is highly predictable. Students who took three methodology courses shared significantly stronger beliefs in the need for psychological research and the importance of training in methodology compared to students who did not take any methodology courses. Furthermore, students with a specialist degree had significantly stronger beliefs that psychology is a science compared to students who have just finished school. In terms of the effect of students’ career aspirations, students who wanted to be academic psychologists and clinicians had significantly stronger beliefs that psychology is a science compared to students who did not have clarity about their future careers. Regardless of the study limitations, these findings have potential implications for Russian psychology instructors

A characterization of those automata that structurally generate finite groups

Antonenko and Russyev independently have shown that any Mealy automaton with no cycles with exit--that is, where every cycle in the underlying directed graph is a sink component--generates a fi- nite (semi)group, regardless of the choice of the production functions. Antonenko has proved that this constitutes a characterization in the non-invertible case and asked for the invertible case, which is proved in this paper

Replication timing in Drosophila and its peculiarities in polytene chromosomes

Drosophila melanogaster is one of the popular model organisms in DNA replication studies. Since the 1960s, DNA replication of polytene chromosomes has been extensively studied by cytological methods. In the recent two decades, the progress in our understanding of DNA replication was associated with new techniques. Use of fluorescent dyes increased the resolution of cytological methods significantly. High-throughput methods allowed analysis of DNA replication on a genome scale, as well as its correlation with chromatin structure and gene activi ty. Precise mapping of the cytological structures of polytene chromosomes to the genome assembly allowed comparison of replication between polytene chromosomes and chromosomes of diploid cells. New features of replication characteristic for D. melanogaster were described for both diploid and polytene chromosomes. Comparison of genomic replication profiles revealed a significant similarity between Drosophila and other well-studi ed eukaryotic species, such as human. Early replication is often confined to intensely transcribed gene-dense regions characterized by multiple replication initiation sites. Features of DNA replication in Drosophila might be explained by a compact genome. The organization of replication in polytene chromosomes has much in common with the organization of replication in chromosomes in diploid cells. The most important feature of replication in polytene chromosomes is its low rate and the dependence of S-phase duration on many factors: external and internal, local and global. The speed of replication forks in D. melanogaster polytene chromosomes is affected by SUUR and Rif1 proteins. It is not known yet how universal the mechanisms associated with these factors are, but their study is very promising

Hexokinase inhibits flux of fluorescently labeled ATP through mitochondrial outer membrane porin

AbstractMitochondrial function requires maintaining metabolite fluxes across the mitochondrial outer membrane, which is mediated primarily by the voltage dependent anion channel (VDAC). We applied fluorescence correlation spectroscopy (FCS) to study regulation of the VDAC functional state by monitoring distribution of fluorescently labeled ATP (BODIPY-FL-ATP) in isolated intact rat liver and heart mitochondria. Addition of mitochondria to BODIPY-FL-ATP solution resulted in accumulation of the fluorescent probe in these organelles. The addition of hexokinase II (HKII) isolated from rat heart led to a decrease in the BODIPY-FL-ATP accumulation, while a 15-residue peptide corresponding to the N-terminal domain of hexokinase did not produce this effect. Therefore, the hexokinase-induced inhibition of the ATP flow mediated by VDAC was revealed in isolated mitochondria

Monte Carlo renormalization group study of the Heisenberg and XY antiferromagnet on the stacked triangular lattice and the chiral ϕ4\phi^4 model

With the help of the improved Monte Carlo renormalization-group scheme, we numerically investigate the renormalization group flow of the antiferromagnetic Heisenberg and XY spin model on the stacked triangular lattice (STA-model) and its effective Hamiltonian, 2N-component chiral $\phi^4$ model which is used in the field-theoretical studies. We find that the XY-STA model with the lattice size $126\times 144 \times 126$ exhibits clear first-order behavior. We also find that the renormalization-group flow of STA model is well reproduced by the chiral $\phi^4$ model, and that there are no chiral fixed point of renormalization-group flow for N=2 and 3 cases. This result indicates that the Heisenberg-STA model also undergoes first-order transition.Comment: v1:15 pages, 15 figures v2:updated references v3:added comments on the higher order irrelevant scaling variables v4:added results of larger sizes v5:final version to appear in J.Phys.Soc.Jpn Vol.72, No.

The critical behavior of frustrated spin models with noncollinear order

We study the critical behavior of frustrated spin models with noncollinear order, including stacked triangular antiferromagnets and helimagnets. For this purpose we compute the field-theoretic expansions at fixed dimension to six loops and determine their large-order behavior. For the physically relevant cases of two and three components, we show the existence of a new stable fixed point that corresponds to the conjectured chiral universality class. This contradicts previous three-loop field-theoretical results but is in agreement with experiments.Comment: 4 pages, RevTe