ALBERT

Description: Mammalian splicing regulatory protein RNA-binding motif protein 4 (RBM4) has an alanine repeat-containing C-terminal domain (CAD) that confers both nuclear- and splicing speckle-targeting activities. Alanine-repeat expansion has pathological potential. Here we show that the alanine-repeat tracts influence the subnuclear targeting properties of the RBM4 CAD in cultured human cells. Notably, truncation of the alanine tracts redistributed a portion of RBM4 to paraspeckles. The alanine-deficient CAD was sufficient for paraspeckle targeting. On the other hand, alanine-repeat expansion reduced the mobility of RBM4 and impaired its splicing activity. We further took advantage of the putative coactivator activator (CoAA)-RBM4 conjoined splicing factor, CoAZ, to investigate the function of the CAD in subnuclear targeting. Transiently expressed CoAZ formed discrete nuclear foci that emerged and subsequently separated—fully or partially—from paraspeckles. Alanine-repeat expansion appeared to prevent CoAZ separation from paraspeckles, resulting in their complete colocalization. CoAZ foci were dynamic but, unlike paraspeckles, were resistant to RNase treatment. Our results indicate that the alanine-rich CAD, in conjunction with its conjoined RNA-binding domain(s), differentially influences the subnuclear localization and biogenesis of RBM4 and CoAZ.

Description: Author(s): S. R. Beane, E. Chang, S. D. Cohen, W. Detmold, H. W. Lin, T. C. Luu, K. Orginos, A. Parreño, M. J. Savage, and A. Walker-Loud (NPLQCD Collaboration) The binding energies of a range of nuclei and hypernuclei with atomic number A ≤4 and strangeness | s |≤2, including the deuteron, dineutron, H-dibaryon, 3 He, Λ 3 He, 4 He, Λ 4 He, and Λ Λ 4 He, are calculated in the limit of flavor-SU(3) symmetry at the physical strange-quark mass with quantum chromodynamics ... [Phys. Rev. D 87, 034506] Published Mon Feb 11, 2013

Description: Author(s): C. S. Hwang, J. C. Jan, C. S. Chang, S. D. Chen, C. H. Chang, and T. M. Uen The in-vacuum undulator with a permanent magnet at room temperature is a mature technology and is widely used; with a short period length in a medium-energy facility, it can enhance photon brilliance in the hard x-ray region. A cryogenic permanent magnet has been investigated as an in-vacuum undulat... [Phys. Rev. ST Accel. Beams 14, 044801] Published Thu Apr 28, 2011

Description: Author(s): S. Y. Chang, S. Pathak, and N. Trivedi We investigate a system of fermions on a two-dimensional optical square lattice in the strongly repulsive coupling regime. In this case, the interactions can be controlled by laser intensity as well as by Feshbach resonance. We compare the energetics of states with resonating valence bond d -wave sup... [Phys. Rev. A 85, 013625] Published Wed Jan 18, 2012

Description: Mutations in GATA4 and TBX5 are associated with congenital heart defects in humans. Interaction between GATA4 and TBX5 is important for normal cardiac septation, but the underlying molecular mechanisms are not well understood. Here, we show that Gata4 and Tbx5 are co-expressed in the embryonic atria and ventricle, but after E15.5, ventricular expression of Tbx5 decreases. Co-localization and co-immunoprecipitation studies demonstrate an interaction of Gata4 and Tbx5 in the developing atria and ventricles, but the ventricular interaction declines after E14.5. Gata4 +/– ;Tbx5 +/– mouse embryos display decreased atrial and ventricular myocardial thickness at E11.5, prior to cardiac septation. To determine the cell lineage in which the interaction was functionally significant in vivo , mice heterozygous for Gata4 in the myocardium or endocardium and heterozygous for Tbx5 ( Gata4 MyoDel/wt ;Tbx5 +/– and Gata4 EndoDel/wt ;Tbx5 +/– , respectively) were generated. Gata4 MyoDel/wt ;Tbx5 +/– mice displayed embryonic lethality, thin myocardium with reduced cell proliferation, and atrioventricular septation defects similar to Gata4;Tbx5 compound heterozygotes while Gata4 EndoDel/wt ;Tbx5 +/– embryos were normal. Cdk4 and Cdk2 , cyclin-dependent kinases required for myocardial development and septation were reduced in Gata4 +/– ;Tbx5 +/– hearts. Cdk4 is a known direct target of Gata4 and the regulation of Cdk2 in the developing heart has not been studied. Chromatin immunoprecipitation and transactivation studies demonstrate that Gata4 and Tbx5 directly regulate Cdk4 while only Tbx5 activates Cdk2 expression. These findings highlight the mechanisms by which disruption of the Gata4 and Tbx5 interaction in the myocardium contributes to cardiac septation defects in humans.

Description: Author(s): S. R. Beane, E. Chang, S. Cohen, W. Detmold, H. W. Lin, K. Orginos, A. Parreño, M. J. Savage, and B. C. Tiburzi (NPLQCD Collaboration) We present the results of lattice QCD calculations of the magnetic moments of the lightest nuclei, the deuteron, the triton, and 3 He, along with those of the neutron and proton. These calculations, performed at quark masses corresponding to m π ∼800  MeV, reveal that the structure of these nuclei at u... [Phys. Rev. Lett. 113, 252001] Published Tue Dec 16, 2014

Description: Author(s): A. Privitera, I. Titvinidze, S.-Y. Chang, S. Diehl, A. J. Daley, and W. Hofstetter We study the physics of a three-component Fermi gas in an optical lattice, in the presence of a three-body constraint arising due to strong three-body loss. Using analytical and numerical techniques, we show that an atomic color superfluid phase is formed in this system and undergoes phase separatio... [Phys. Rev. A 84, 021601] Published Wed Aug 03, 2011

Description: Author(s): Seo Hyoung Chang, Young Jun Chang, S. Y. Jang, D. W. Jeong, C. U. Jung, Y.-J. Kim, J.-S. Chung, and T. W. Noh We grew epitaxial SrRuO 3 (SRO) films on SrTiO 3 (STO) (001) substrates with SRO layer thicknesses ( t ) between 10 and 200 pseudocubic unit cells (uc). Using the square net of the cubic STO surface, we were able to epi-stabilize the tetragonal SRO phase at room temperature for ultrathin films with t ⩽ ... [Phys. Rev. B 84, 104101] Published Thu Sep 01, 2011

Description: Scaling relationships among twig size, leaf size and leafing intensity fundamentally influence the twig–leaf deployment pattern, a property that affects the architecture and functioning of plants. However, our understanding of how these relationships change within a species or between species as a function of forest succession is unclear. We determined log–log scaling relationships between twig cross-sectional area (twig size) and each of total and individual leaf area, and leafing intensity (the number of leaves per twig volume) for 78 woody species along a successional series in subtropical evergreen forests in eastern China. The series included four stages: secondary shrub (S1), young (S2), sub-climax (S3) and climax evergreen broadleaved forests (S4). The scaling slopes in each of the three relationships did not differ among the four stages. The y -intercept did not shift among the successional stages in the relationship between twig cross-sectional area and total leaf area; however, the y -intercept was greatest in S4, intermediate in S3 and lowest in S2 and S1 for the relationship between twig size and individual leaf area, while the opposite pattern was found for the twig size-leafing intensity relationship. This indicates that late successional trees have few but large leaves while early successional trees have more small leaves per unit twig size. For the relationship between twig cross-sectional area and total leaf area, there was no difference in the regression slope between recurrent (appear in more than one stages) and non-recurrent species (appear in only one stage) for each of the S1–S2, S2–S3 and S3–S4 pairs. A significant difference in the y -intercept was found in the S2–S3 pair only. In the relationship between twig cross-sectional area and individual leaf area, the regression slope between recurrent and non-recurrent species was homogeneous in the S1–S2 and S3–S4 pairs, but heterogeneous in the S2–S3 pair. We conclude that forest succession caused the shift in the intercept, but did not affect scaling slopes for relationships among twig size, leaf size and leaf intensity. For recurrent species, the invariant scaling slope in the twig–leaf size relationship between adjacent pairs of successional stages may be related to their phenotypic plasticity by adjusting their twig and leaf deployment strategy to similar to what the non-recurrent species display.

Description: Author(s): Chang S. Shin, Mark C. Butler, Hai-Jing Wang, Claudia E. Avalos, Scott J. Seltzer, Ren-Bao Liu, Alexander Pines, and Vikram S. Bajaj We report sensitive detection of the nuclear quadrupolar interaction of the 14 N nuclear spin of the nitrogen-vacancy (NV) center using the electron spin-echo envelope modulation technique. We applied a weak transverse magnetic field to the spin system so that certain forbidden transitions became wea... [Phys. Rev. B 89, 205202] Published Thu May 15, 2014