Direct observation of the proliferation of ferroelectric loop domains and vortex-antivortex pairs

We discovered "stripe" patterns of trimerization-ferroelectric domains in hexagonal REMnO3 (RE=Ho, ---, Lu) crystals (grown below ferroelectric transition temperatures (Tc), reaching up to 1435 oC), in contrast with the vortex patterns in YMnO3. These stripe patterns roughen with the appearance of numerous loop domains through thermal annealing just below Tc, but the stripe domain patterns turn to vortex-antivortex domain patterns through a freezing process when crystals cross Tc even though the phase transition appears not to be Kosterlitz-Thouless-type. The experimental systematics are compared with the results of our six-state clock model simulation and also the Kibble-Zurek Mechanism for trapped topological defects

Asymmetry in fatigue and recovery in ferroelectric Pb(Zr,Ti)O3 thin-film capacitors

We investigate the fatigue and refreshment by dc-electrical field of the electrical properties of Pt/Pb(Ti,Zr)O$_3$/Pt ferroelectric capacitors. We find an asymmetry in the refreshment, that is, the fatigued state can be refreshed by application of negative high dc-voltage to the top electrode, but no refreshment is measured by positive dc-voltage application. We also find that the fatigue can be prevented by driving the capacitor asymmetrically.Comment: 4 pages, 5 figure

DNA hypomethylation and germ cell-specific expression of testis-specific H2B histone gene

Testis-specific H2B (TH2B) histone gene of rat is expressed during meiotic event of spermatogenic differentiation. The gene is unusual in that it has conserved the regulatory elements involved in the S phase-specific transcription of somatic H2B genes as well as the S phase-specific stabilization of histone mRNA. Genomic sequencing revealed that all analyzed CpG sites in the promoter region of TH2B gene are methylated in somatic tissues but not in testis. During spermatogenesis, these CpG sites are unmethylated as early as spermatogonia type A and up to sperm. Thus, there is a good correlation between DNA hypomethylation and germ cell-specific expression of TH2B gene. Results obtained from in vivo DNase footprinting and DNA mobility shift experiments are consistent with the hypothesis that DNA methylation inhibits gene activity by preventing the binding of transcription factors to their recognition sequences. The results show that (i) the binding of ubiquitous transcription factors to the promoter region of TH2B gene may be blocked in nuclei of liver, and (ii) DNA methylation can directly interfere with the binding of transcription factors recognizing a hexamer (ACGTCA) motif. In vitro DNA methylation and transfection experiments demonstrated that expression of TH2B gene is inhibited by DNA methylation in vivo. These findings indicate that DNA methylation may play a key role in the transcriptional repression of germ cell-specific TH2B gene

Global classical solutions for partially dissipative hyperbolic system of balance laws

This work is concerned with ($N$-component) hyperbolic system of balance laws in arbitrary space dimensions. Under entropy dissipative assumption and the Shizuta-Kawashima algebraic condition, a general theory on the well-posedness of classical solutions in the framework of Chemin-Lerner's spaces with critical regularity is established. To do this, we first explore the functional space theory and develop an elementary fact that indicates the relation between homogeneous and inhomogeneous Chemin-Lerner's spaces. Then this fact allows to prove the local well-posedness for general data and global well-posedness for small data by using the Fourier frequency-localization argument. Finally, we apply the new existence theory to a specific fluid model-the compressible Euler equations with damping, and obtain the corresponding results in critical spaces.Comment: 39 page

Observations of bunch lengthening effects in the APS 7-GeV storage ring

Measurements of the bunch length and horizontal beam size at a dispersive point in the lattice versus single-bunch current have been done on the Advanced Photo Source (APS) 7-GeV storage ring. These data are relevant to issues (limits) of obtaining high peak currents for storage-ring-based FELs. Bunch lengths from {sigma}{sub {tau}} {approx} 25 to 70 ps were measured using a Hamamatsu C5680 dual-sweep streak camera. Additional complementary data on energy spread deduced from horizontal beam size at a dispersive point in the lattice were also tracked versus single-bunch current. Both optical synchrotron radiation (OSR) and x-ray synchrotron radiation (XSR) techniques were used. For the set of data taken at a synchrotron frequency of 1.2 kHz (indicating rf gap voltage {<=} 6 MV), the significant bunch lengthening without a comparable horizontal size change ({Delta}E growth) is consistent with the potential well distortion model rather than the predictions of a microwave instability calculation. With higher rf gap voltage, peak currents up to 400 A were observed. A bunch-lengthening effect in multibunch mode was also observed as the stored-beam current approached the available rf power limit

A role for core planar polarity proteins in cell contact-mediated orientation of planar cell division across the mammalian embryonic skin

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. © The Author(s) 2017. Supplementary information accompanies this paper at doi:10.1038/s41598-017-01971-2.The question of how cell division orientation is determined is fundamentally important for understanding tissue and organ shape in both healthy or disease conditions. Here we provide evidence for cell contact-dependent orientation of planar cell division in the mammalian embryonic skin. We propose a model where the core planar polarity proteins Celsr1 and Frizzled-6 (Fz6) communicate the long axis orientation of interphase basal cells to neighbouring basal mitoses so that they align their horizontal division plane along the same axis. The underlying mechanism requires a direct, cell surface, planar polarised cue, which we posit depends upon variant post-translational forms of Celsr1 protein coupled to Fz6. Our hypothesis has parallels with contact-mediated division orientation in early C. elegans embryos suggesting functional conservation between the adhesion-GPCRs Celsr1 and Latrophilin-1. We propose that linking planar cell division plane with interphase neighbour long axis geometry reinforces axial bias in skin spreading around the mouse embryo body.Peer reviewe