6,726 research outputs found
Study of orientation effect on nanoscale polarization in BaTiO3 thin films using piezoresponse force microscopy
We have investigated the effect of texture on in-plane (IPP) and out- of plane (OPP) polarizations of pulsed-laser-deposited BaTiO3 thin films grown on Pt and La0.5Sr0.5CoO3 (LSCO) buffered Pt electrodes. The OPP and IPP polarizations were observed by piezoresponse force microscopy (PFM) for three-dimensional polarization analyses in conjunction with conventional diffraction methods using x-ray diffraction and reflection high energy electron diffraction measurements. BaTiO3 films grown on Pt electrodes exhibited highly (101) preferred orientation with higher IPP component whereas BaTiO3 film grown on LSCO/Pt electrodes showed (001) and (101) orientations with higher OPP component. Measured effective d(33) values of BaTiO3 films deposited on Pt and LSCO/ Pt electrodes were 14.3 and 54.0 pm/ V, respectively. Local piezoelectric strain loops obtained by OPP and IPP-PFM showed that piezoelectric properties were strongly related to film orientation
Five Simple and Low Maintenance Investing Strategies: Seeking an Automated Investing System
The purpose of the paper is to examine five different investment strategies which are known to be easily implemented by ordinary investors: (1) S&P 500 strategy, (2) No OTC & No ADR (NoOtcAdr) strategy, (3) Warren Buffettās stock market indicator-based strategy, (4) Federal Reserve Bankās monetary policy-based strategy, and (5) Joel Greenblattās magic formula strategy. Among a large number of minimal maintenance strategies available, we investigate the efficacy of these five investment strategies because these strategies are extremely simple to implement and require little time commitment for investment research. Once they are set up, they will be maintenance free. Based on our findings and analysis, we propose a pair of options to retail investors, depending on their time commitment and risk tolerance level. Among five investment strategies, investors with high-risk tolerance may find merits in the Fedās monetary policy-based strategy, whereas investors with low-risk tolerance may find Buffettās stock market indicator-based strategy attractive. Keywords: Low maintenance investing strategies; Fed funds rate; Greenblattās magic formula; Sector rotation, Warren Buffett stock market indicator DOI: 10.7176/RJFA/11-2-01 Publication date: January 31st 202
BRG1 directly regulates nucleosome structure and chromatin looping of the Ī± globin locus to activate transcription
Ī± globin expression must be regulated properly to prevent the occurrence of Ī±-thalassemias, yet many questions remain unanswered regarding the mechanism of transcriptional activation. Identifying factors that regulate chromatin structure of the endogenous Ī± globin locus in developing erythroblasts will provide important mechanistic insight. Here, we demonstrate that the BRG1 catalytic subunit of SWI/SNF-related complexes co-immunoprecipitates with GATA-1 and EKLF in murine fetal liver cells in vivo and is recruited to the far-upstream major-regulatory element (MRE) and Ī±2 promoter. Furthermore, based on our analysis of Brg1null/ENU1 mutant mice, BRG1 regulates DNase I sensitivity, H3ac, and H3K4me2 but not CpG methylation at both sites. Most importantly, BRG1 is required for chromatin loop formation between the MRE and Ī±2 promoter and for maximal RNA Polymerase II occupancy at the Ī±2 promoter. Consequently, Brg1 mutants express Ī± globin mRNA at only 5ā10% of wild-type levels and die at mid-gestation. These data identify BRG1 as a chromatin-modifying factor required for nucleosome remodeling and transcriptional activation of the Ī± globin locus. These data also demonstrate that chromatin looping between the MRE and Ī±2 promoter is required as part of the transcriptional activation mechanism
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The Spitzer C2D Survey of Nearby Dense Cores: Jet and Molecular Outflow Associated With A Young Stellar Object in Core A of L1251
A long infrared jet has been discovered by the Spitzer c2d Legacy Program in core A of L1251. It is associated with a very embedded Class 0 object with an accretion luminosity of about 0.9 L(circle dot) derived by radiative transfer model fitting to the observed spectral energy distribution. Comparing the observed Infrared Array Camera colors along the infrared jet with those calculated from a model of an admixture of gas with a power-law temperature distribution indicates that the jet is possibly created by a paraboloidal bow shock propagating into the ambient medium of n(H(2)) = 10(5) cm(-3). In addition, the variation of the power-law index along the jet suggests that the portion of hot gas decreases with distance from the jet engine. The molecular outflow in this region has been mapped for the first time using CO data. From the calculated outflow momentum flux, a very strong lower limit to the average accretion luminosity is 3.6 sin i/cos(3) i L(circle dot), indicative of a decrease in the accretion rate with time.Korean government (MEST) 2009-0062865NRF R01-2007-000-20336-0NASA 1407, 1224608Astronom
J/psi hadron interaction in vacuum and in QGP
Motivated by the recent lattice data that will survive up to
1.6, we calculate the thermal width of at finite temperature in
perturbative QCD. The inputs of the calculation are the parton quarkonium
dissociation cross sections at the NLO in QCD, which were previously obtained
by Song and Lee, and a gaussian charmonium wave function, whose size were
fitted to an estimate by Wong by solving the schrodinger equation for
charmonium in a potential extracted from the lattice at finite temperature. We
find that the total thermal width above 1.4 becomes larger than 100 to 200
MeV, depending on the effective thermal masses of the quark and gluon, which we
take it to vary from 600 to 400 MeV.Comment: 4 pages, Talk at Quark Matter 200
Local structures of polar wurtzites Zn_{1-x}Mg_{x}O studied by Raman and {67}Zn/{25}Mg NMR spectroscopies and by total neutron scattering
Local compositions and structures of Zn_{1-x}Mg_{x}O alloys have been
investigated by Raman and solid-state {67}Zn/{25}Mg nuclear magnetic resonance
(NMR) spectroscopies, and by neutron pair-distribution-function (PDF) analyses.
The E2(low) and E2(high) Raman modes of Zn_{1-x}Mg_{x}O display Gaussian- and
Lorentzian-type profiles, respectively. At higher Mg substitutions, both modes
become broader, while their peak positions shift in opposite directions. The
evolution of Raman spectra from Zn_{1-x}Mg_{x}O solid solutions are discussed
in terms of lattice deformation associated with the distinct coordination
preferences of Zn and Mg. Solid-state magic-angle-spinning (MAS) NMR studies
suggest that the local electronic environments of {67}Zn in ZnO are only weakly
modified by the 15% substitution of Mg for Zn. {25}Mg MAS spectra of
Zn_{0.85}Mg_{0.15}O show an unusual upfield shift, demonstrating the prominent
shielding ability of Zn in the nearby oxidic coordination sphere. Neutron PDF
analyses of Zn_{0.875}Mg_{0.125}O using a 2x2x1 supercell corresponding to
Zn_{7}MgO_{8} suggest that the mean local geometry of MgO_{4} fragments concurs
with previous density functional theory (DFT)-based structural relaxations of
hexagonal wurtzite MgO. MgO_{4} tetrahedra are markedly compressed along their
c-axes and are smaller in volume than ZnO_{4} units by ~6%. Mg atoms in
Zn_{1-x}Mg_{x}O have a shorter bond to the -axial oxygen atom than to the
three lateral oxygen atoms, which is distinct from the coordination of Zn. The
precise structure, both local and average, of Zn_{0.875}Mg_{0.125}O obtained
from time-of-flight total neutron scattering supports the view that
Mg-substitution in ZnO results in increased total spontaneous polarization.Comment: 12 pages, 14 figures, 2 table
Far-Ultraviolet Cooling Features of the Antlia Supernova Remnant
We present far-ultraviolet observations of the Antlia supernova remnant
obtained with Far-ultraviolet IMaging Spectrograph (FIMS, also called SPEAR).
The strongest lines observed are C IV 1548,1551 and C III 977. The C IV
emission of this mixed-morphology supernova remnant shows a clumpy
distribution, and the line intensity is nearly constant with radius. The C III
977 line, though too weak to be mapped over the whole remnant, is shown to vary
radially. The line intensity peaks at about half the radius, and drops at the
edge of the remnant. Both the clumpy distribution of C IV and the rise in the C
IV to C III ratio towards the edge suggest that central emission is from
evaporating cloudlets rather than thermal conduction in a more uniform, dense
medium.Comment: 9 pages, 4 figures, will be published in ApJ December 1, 2007, v670n2
issue. see http://astro.snu.ac.kr/~jhshinn/ms.pd
Full-length genomic analysis of korean porcine sapelovirus strains.
Porcine sapelovirus (PSV), a species of the genus Sapelovirus within the family Picornaviridae, is associated with diarrhea, pneumonia, severe neurological disorders, and reproductive failure in pigs. However, the structural features of the complete PSV genome remain largely unknown. To analyze the structural features of PSV genomes, the full-length nucleotide sequences of three Korean PSV strains were determined and analyzed using bioinformatic techniques in comparison with other known PSV strains. The Korean PSV genomes ranged from 7,542 to 7,566 nucleotides excluding the 3' poly(A) tail, and showed the typical picornavirus genome organization; 5'untranslated region (UTR)-L-VP4-VP2-VP3-VP1-2A-2B-2C-3A-3B-3C-3D-3'UTR. Three distinct cis-active RNA elements, the internal ribosome entry site (IRES) in the 5'UTR, a cis-replication element (CRE) in the 2C coding region and 3'UTR were identified and their structures were predicted. Interestingly, the structural features of the CRE and 3'UTR were different between PSV strains. The availability of these first complete genome sequences for PSV strains will facilitate future investigations of the molecular pathogenesis and evolutionary characteristics of PSV
Microlensing Detections of Planets in Binary Stellar Systems
We demonstrate that microlensing can be used for detecting planets in binary
stellar systems. This is possible because in the geometry of planetary binary
systems where the planet orbits one of the binary component and the other
binary star is located at a large distance, both planet and secondary companion
produce perturbations at a common region around the planet-hosting binary star
and thus the signatures of both planet and binary companion can be detected in
the light curves of high-magnification lensing events. We find that identifying
planets in binary systems is optimized when the secondary is located in a
certain range which depends on the type of the planet. The proposed method can
detect planets with masses down to one tenth of the Jupiter mass in binaries
with separations <~ 100 AU. These ranges of planet mass and binary separation
are not covered by other methods and thus microlensing would be able to make
the planetary binary sample richer.Comment: 5 pages, two figures in JPG forma
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