122 research outputs found
Development of microsatellite markers in the toxic dinoflagellate Alexandrium minutum (Dinophyceae)
Author Posting. © Blackwell, 2006. This is the author's version of the work. It is posted here by permission of Blackwell for personal use, not for redistribution. The definitive version was published in Molecular Ecology Notes 6 (2006): 756-758, doi:10.1111/j.1471-8286.2006.01331.x.Outbreaks of paralytic shellfish poisoning caused by the toxic dinoflagellate Alexandrium minutum (Dinophyceae) are a worldwide concern from both the economic and human health points of view. For population genetic studies of A. minutum distribution and dispersal, highly polymorphic genetic markers are of great value. We isolated 12 polymorphic microsatellites from this cosmopolitan, toxic dinoflagellate species. These loci provide one class of highly variable genetic markers, as the number of alleles ranged from 4 to 12, and the estimate of gene diversity was from 0.560 to 0.862 across the 12 microsatellites; these loci have the potential to reveal genetic structure and gene flow among A. minutum populations.Support for this research provided in part (to DMA) by U.S. National Science Foundation grants OCE-0136861 and OCE-0430724, and the National Institute of Environmental Health Sciences Grant 1 P50 ES012742-01
Subaru Deep Survey V. A Census of Lyman Break Galaxies at z=4 and 5 in the Subaru Deep Fields: Photometric Properties
(abridged) We investigate photometric properties of Lyman Break Galaxies
(LBGs) at z=3.5-5.2 based on large samples of 2,600 LBGs detected in deep
(i'~27) and wide-field (1,200 arcmin^2) images taken in the Subaru Deep Field
(SDF) and the Subaru/XMM Deep Field (SXDF). The selection criteria for the LBG
samples are examined with 85 spectroscopically identified objects and by Monte
Carlo simulations. We find in the luminosity functions of LBGs (i) that the
number density of bright galaxies (M_{1700}<-22; corresponding to
SFR_{corr}>100 Msolar yr^{-1}) decreases significantly from z=4 to 5 and (ii)
that the faint-end slope of the luminosity function may become steeper towards
higher redshifts. We estimate dust extinction of z=4 LBGs with M<M^* from UV
slopes, and obtain E(B-V)=0.15+/-0.03 as the mean value. The dust extinction
remains constant with apparent luminosity, but increases with intrinsic
luminosity. We find no evolution in dust extinction between LBGs at z=3 and 4.
We investigate the evolution of UV-luminosity density at 1700A, rho, and find
that rho does not significantly change from z=3 to z=5, i.e.,
rho(z=4)/rho(z=3)=1.0+/-0.2 and rho(z=5)/rho(z=3)=0.8+/-0.4, thus the cosmic
star-formation rate (SFR) density remains constant. We find that the stellar
mass density estimated from the cosmic SFR is consistent with those derived
directly from the stellar mass function at z=0-1, but exceeds those at z~3 by a
factor of 3. We find that the ratio of the UV-luminosity density of Ly-a
emitters (LAEs) to that of LBGs is ~60% at z=5, and thus about a half of the
star formation at z=5 probably occurs in LAEs. We obtain a constraint on the
escape fraction of UV-ionizing photons produced by LBGs, f_{esc}>~0.13.Comment: 41 pages, 22 figures, ApJ in press. Paper with high resolution
figures is available at
http://hikari.astron.s.u-tokyo.ac.jp/~ouchi/work/astroph/SDS_V_VI/SDS_V.pdf
(PDF
Cosmic shear statistics in the Suprime-Cam 2.1 sq deg field: Constraints on Omega_m and sigma_8
We present measurements of the cosmic shear correlation in the shapes of
galaxies in the Suprime-Cam 2.1 deg^2 R_c-band imaging data. As an estimator of
the shear correlation originated from the gravitational lensing, we adopt the
aperture mass variance. We detect a non-zero E mode variance on scales between
2 and 40arcmin. We also detect a small but non-zero B mode variance on scales
larger than 5arcmin. We compare the measured E mode variance to the model
predictions in CDM cosmologies using maximum likelihood analysis. A
four-dimensional space is explored, which examines sigma_8, Omega_m, Gamma and
zs (a mean redshift of galaxies). We include three possible sources of error:
statistical noise, the cosmic variance estimated using numerical experiments,
and a residual systematic effect estimated from the B mode variance. We derive
joint constraints on two parameters by marginalizing over the two remaining
parameters. We obtain an upper limit of Gamma0.9 (68% confidence).
For a prior Gamma\in[0.1,0.4] and zs\in[0.6,1.4], we find
sigma_8=(0.50_{-0.16}^{+0.35})Omega_m^{-0.37} for flat cosmologies and
sigma_8=(0.51_{-0.16}^{+0.29})Omega_m^{-0.34}$ for open cosmologies (95%
confidence). If we take the currently popular LCDM model, we obtain a
one-dimensional confidence interval on sigma_8 for the 95.4% level,
0.62<\sigma_8<1.32 for zs\in[0.6,1.4]. Information on the redshift distribution
of galaxies is key to obtaining a correct cosmological constraint. An
independent constraint on Gamma from other observations is useful to tighten
the constraint.Comment: 12 pages, 12 figures, accepted for publication in Ap
Subaru Hyper Suprime-Cam Survey for An Optical Counterpart of GW170817
We perform a -band survey for an optical counterpart of a binary neutron
star coalescence GW170817 with Subaru/Hyper Suprime-Cam. Our untargeted
transient search covers deg corresponding to the credible
region of GW170817 and reaches the completeness magnitude of mag
on average. As a result, we find 60 candidates of extragalactic transients,
including J-GEM17btc (a.k.a. SSS17a/DLT17ck). While J-GEM17btc is associated
with NGC 4993 that is firmly located inside the 3D skymap of GW170817, the
other 59 candidates do not have distance information in the GLADE v2 catalog or
NASA/IPAC Extragalactic Database (NED). Among 59 candidates, 58 are located at
the center of extended objects in the Pan-STARRS1 catalog, while one candidate
has an offset. We present location, -band apparent magnitude, and time
variability of the candidates and evaluate the probabilities that they are
located inside of the 3D skymap of GW170817. The probability for J-GEM17btc is
being much higher than those for the other 59 candidates
(). Furthermore, the possibility, that at
least one of the other 59 candidates is located within the 3D skymap, is only
. Therefore, we conclude that J-GEM17btc is the most-likely and
distinguished candidate as the optical counterpart of GW170817.Comment: 14 pages, 9 figures. Accepted for publication in PASJ (Publications
of the Astronomical Society of Japan
LINE-1 hypomethylation status of circulating cell-free DNA in plasma as a biomarker for colorectal cancer.
Colorectal cancer (CRC) is a serious public health problem and non-invasive biomarkers improving diagnosis or therapy are strongly required. Circulating cell-free DNA (cfDNA) has been a promising target for this purpose. In this study, we evaluated the potential of long interspersed nuclear element-1 (LINE-1) hypomethylation as a blood biomarker for CRC. LINE-1 hypomethylation level in plasma cfDNA in 114 CRC patients was retrospectively examined by absolute quantitative analysis of methylated alleles real-time PCR, and was expressed using LINE-1 hypomethylation index (LHI) [unmethylated copy number/ (methylated copy number + unmethylated copy number)]. Greater LHI values indicated enhanced hypomethylation. In our clinicopathological analysis, CRC patients with large tumors (≥6.0 cm), advanced N stage (≥2), and distant metastasis (M1) had statistically significantly higher cfDNA LHI than other CRC patients, suggesting cfDNA LHI as a disease progression biomarker for CRC. Furthermore, early stage I/II (n = 57) as well as advanced stage III/IV (n =57) CRC patients had significantly higher cfDNA LHI than healthy donors (n=53) [stage I/II: median 0.369 (95% confidence interval, 0.360-0.380) vs. 0.332 (0.325-0.339), P \u3c 0.0001; stage III/IV: 0.372 (0.365-0.388) vs. 0.332 (0.325-0.339), P \u3c 0.0001]. The receiver operating characteristic analysis showed that cfDNA LHI had the detection capacity of CRC with area under the curve(AUC) of 0.79 and 0.83 in stage I/II and stage III/IV CRC patients, respectively. The present study demonstrated for the first time the potential of plasma cfDNA LHI as a novel biomarker for CRC, particularly for early stage detection
Small Molecules with Similar Structures Exhibit Agonist, Neutral Antagonist or Inverse Agonist Activity toward Angiotensin II Type 1 Receptor
Small differences in the chemical structures of ligands can be responsible for agonism, neutral antagonism or inverse agonism toward a G-protein-coupled receptor (GPCR). Although each ligand may stabilize the receptor conformation in a different way, little is known about the precise conformational differences. We synthesized the angiotensin II type 1 receptor blocker (ARB) olmesartan, R239470 and R794847, which induced inverse agonism, antagonism and agonism, respectively, and then investigated the ligand-specific changes in the receptor conformation with respect to stabilization around transmembrane (TM)3. The results of substituted cysteine accessibility mapping studies support the novel concept that ligand-induced changes in the conformation of TM3 play a role in stabilizing GPCR. Although the agonist-, neutral antagonist and inverse agonist-binding sites in the AT1 receptor are similar, each ligand induced specific conformational changes in TM3. In addition, all of the experimental data were obtained with functional receptors in a native membrane environment (in situ)
Differential regulation of diacylglycerol kinase isoform in human failing hearts
Evidence from several studies indicates the importance of Gαq protein-coupled receptor (GPCR) signaling pathway, which includes diacylglycerol (DAG), and protein kinase C, in the development of heart failure. DAG kinase (DGK) acts as an endogenous regulator of GPCR signaling pathway by catalyzing and regulating DAG. Expressions of DGK isoforms α, ε, and ζ in rodent hearts have been detected; however, the expression and alteration of DGK isoforms in a failing human heart has not yet been examined. In this study, we detected mRNA expressions of DGK isoforms γ, η, ε, and ζ in failing human heart samples obtained from patients undergoing cardiovascular surgery with cardiopulmonary bypass. Furthermore, we investigated modulation of DGK isoform expression in these hearts. We found that expressions of DGKη and DGKζ were increased and decreased, respectively, whereas those of DGKγ and DGKε remained unchanged. This is the first report that describes the differential regulation of DGK isoforms in normal and failing human hearts
1,8-Cineole Inhibits Both Proliferation and Elongation of BY-2 Cultured Tobacco Cells
Volatile monoterpenes such as 1,8-cineole inhibit the growth of Brassica campestris seedlings in a dose-dependent manner, and the growth-inhibitory effects are more severe for roots than hypocotyls. The preferential inhibition of root growth may be explained if the compounds inhibit cell proliferation more severely than cell elongation because root growth requires both elongation and proliferation of the constituent cells, whereas hypocotyl growth depends exclusively on elongation of existing cells. In order to examine this possibility, BY-2 suspension-cultured tobacco (Nicotiana tabacum) cells were treated with 1,8-cineole, and the inhibitory effects on cell proliferation and on cell elongation were assessed quantitatively. Treatment with 1,8-cineole lowered both the mitotic index and elongation of the cells in a dose-dependent manner, and the half-maximal inhibitory concentration (IC50) for cell elongation was lower than that for cell proliferation. Moreover, 1,8-cineole also inhibited starch synthesis, with IC50 lower than that for cell proliferation. Thus, the inhibitory effects of 1,8-cineole were not specific to cell proliferation; rather, 1,8-cineole seemed inhibitory to a variety of physiological activities when it was in direct contact with target cells. Based on these results, possible mechanisms for the mode of action of 1,8-cineole and for its preferential inhibition on root growth are discussed
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