3,137 research outputs found
Molecular cloning and mRNA expression pattern of Sox9 during sex reversal in orange-spotted grouper (Epinephelus coioides)
Sox9 is a key gene in male sex determination and gonad development. To study its potential function in the female-to-male sex reversal in orange-spotted grouper, we conducted the following studies. The Sox9 gene was cloned and full-length sequence of Sox9 mRNA was determined using the rapid amplification of cDNA ends method. The Sox9 mRNA consists of 3277 bp in size with a 328 bp 5' untranslated region and a 1511 bp 3' untranslated region. The 1437 bp opening reading frame encodes a 479 amino acid protein. The Sox9 gene contains 3 exons and 2 introns; the beginning and end of both introns conform to the "GT-AG" rule. RT-PCR analysis indicated that Sox9 mRNA was expressed in brain, kidney, heart, liver, muscle, stomach, intestine, spleen, testis and ovary in adult orange-spotted grouper. Artificial sex reversal was successfully performed by implanting a medicinal strip containing 17 alpha-methyltestosterone into the groupers. By real-time PCR, we found that Sox9 was weakly expressed in the ovary-stage gonads (before treatment). Once the sex reversal began (1 week after treatment), Sox9 mRNA expression level significantly increased. However, at 2 weeks after treatment, Sox9 mRNA expression level significantly decreased to a level that was only slightly higher than that before treatment Sox9 mRNA expression increased again at 4 weeks after treatment, and at 6 and 8 weeks, it was maintained at a high level close to that at 1 week after treatment. The results suggest that Sox9 may be one of the important factors initiating and maintaining the masculinization of orange-spotted grouper during sex reversal. (C) 2010 Elsevier B.V. All rights reserved
Discovery of a radio lobe in the Cloverleaf Quasar at z = 2.56
The fast growth of supermassive black holes and their feedback to the host
galaxies play an important role in regulating the evolution of galaxies,
especially in the early Universe. However, due to cosmological dimming and the
limited angular resolution of most observations, it is difficult to resolve the
feedback from the active galactic nuclei (AGN) to their host galaxies.
Gravitational lensing, for its magnification, provides a powerful tool to
spatially differentiate emission originated from AGN and host galaxy at high
redshifts. Here we report a discovery of a radio lobe in a strongly lensed
starburst quasar, H1413+117 or Cloverleaf at redshift , based on
observational data at optical, sub-millimetre, and radio wavelengths. With both
parametric and non-parametric lens models and with reconstructed images on the
source plane, we find a differentially lensed, kpc scaled, single-sided radio
lobe, located at to the north west of the host galaxy
on the source plane. From the spectral energy distribution in radio bands, we
find that the radio lobe has an energy turning point residing between 1.5 GHz
and 8 GHz, indicating an age of 20--50 Myr. This could indicate a feedback
switching of Cloverleaf quasar from the jet mode to the quasar mode
Refining new-physics searches in B -> D tau nu decay with lattice QCD
The semileptonic decay channel B -> D tau nu is sensitive to the presence of
a scalar current, such as that mediated by a charged-Higgs boson. Recently the
BaBar experiment reported the first observation of the exclusive semileptonic
decay B -> D tau nu, finding an approximately 2-sigma disagreement with the
Standard-Model prediction for the ratio R(D)=BR(B->D tau nu)/BR(B->D l nu),
where l=e,mu. We compute this ratio of branching fractions using hadronic form
factors computed in unquenched lattice QCD and obtain R(D) = 0.316(12)(7),
where the errors are statistical and total systematic, respectively. This
result is the first Standard-Model calculation of R(D) from ab initio full QCD.
Its error is smaller than that of previous estimates, primarily due to the
reduced uncertainty in the scalar form factor f_0(q^2). Our determination of
R(D) is approximately 1-sigma higher than previous estimates and, thus, reduces
the tension with experiment. We also compute R(D) in models with electrically
charged scalar exchange, such as the type II two-Higgs doublet model. Once
again, our result is consistent with, but approximately 1-sigma higher than,
previous estimates for phenomenologically relevant values of the scalar
coupling in the type II model. As a byproduct of our calculation, we also
present the Standard-Model prediction for the longitudinal polarization ratio
P_L (D)= 0.325(4)(3).Comment: 6 pages, 3 figures, 1 table. References and text added. Fig. 3 R(D)
in 2HDM II corrected and conclusions modified. Standard-Model R(D) unchange
B_s->D_s/B->D Semileptonic Form-Factor Ratios and Their Application to BR(B^0_s->\mu^+\mu^-)
We calculate form-factor ratios between the semileptonic decays
\bar{B}->D^+\ell^-\bar{\nu} and \bar{B}_s->D_s^+\ell^-\bar{\nu} with lattice
QCD. These ratios are a key theoretical input in a new strategy to determine
the fragmentation fractions of the neutral B decays, which are needed for
measurements of BR(B^0_s-> \mu^+\mu^-). We use the MILC ensembles of gauge
configurations with 2+1 flavors of sea quarks at two lattice spacings of
approximately 0.12 fm and 0.09 fm. We use the model-independent
z-parametrization to extrapolate our simulation results at small recoil toward
maximum recoil. Our results for the form-factor ratios are
and
. In
contrast to a QCD sum-rule calculation, no significant departure from U-spin
(ds) symmetry is observed.Comment: 30 pages, 11 figures. Fig. 1 updated. Table II added. Conforms with
version published in Physical Review D, except typos fixed, as in the PRD
Erratum, in Table V (previously Table IV in arXiv v1). Results unchange
Glecaprevir and pibrentasvir for 12 weeks for hepatitis C virus genotype 1 infection and prior direct-acting antiviral treatment: Poordad et al.
Although direct‐acting antiviral (DAA) therapies for chronic hepatitis C virus (HCV) infection have demonstrated high rates of sustained virologic response, virologic failure may still occur, potentially leading to the emergence of viral resistance, which can decrease the effectiveness of subsequent treatment. Treatment options for patients who failed previous DAA‐containing regimens, particularly those with nonstructural protein 5A inhibitors, are limited and remain an area of unmet medical need. This phase 2, open‐label study (MAGELLAN‐1) evaluated the efficacy and safety of glecaprevir (GLE) + pibrentasvir (PIB) ± ribavirin (RBV) in HCV genotype 1–infected patients with prior virologic failure to HCV DAA‐containing therapy. A total of 50 patients without cirrhosis were randomized to three arms: 200 mg GLE + 80 mg PIB (arm A), 300 mg GLE + 120 mg PIB with 800 mg once‐daily RBV (arm B), or 300 mg GLE + 120 mg PIB without RBV (arm C). By intent‐to‐treat analysis, sustained virologic response at posttreatment week 12 was achieved in 100% (6/6, 95% confidence interval 61‐100), 95% (21/22, 95% confidence interval 78‐99), and 86% (19/22, 95% confidence interval 67‐95) of patients in arms A, B, and C, respectively. Virologic failure occurred in no patients in arm A and in 1 patient each in arms B and C (two patients were lost to follow‐up in arm C). The majority of adverse events were mild in severity; no serious adverse events related to study drug and no relevant laboratory abnormalities in alanine aminotransferase, total bilirubin, or hemoglobin were observed. Conclusion: The combination of GLE and PIB was highly efficacious and well tolerated in patients with HCV genotype 1 infection and prior failure of DAA‐containing therapy; RBV coadministration did not improve efficacy. (Hepatology 2017;66:389–397)
A genetic variation map for chicken with 2.8 million single-nucleotide polymorphisms
We describe a genetic variation map for the chicken genome containing 2.8 million single-nucleotide polymorphisms ( SNPs). This map is based on a comparison of the sequences of three domestic chicken breeds ( a broiler, a layer and a Chinese silkie) with that of their wild ancestor, red jungle fowl. Subsequent experiments indicate that at least 90% of the variant sites are true SNPs, and at least 70% are common SNPs that segregate in many domestic breeds. Mean nucleotide diversity is about five SNPs per kilobase for almost every possible comparison between red jungle fowl and domestic lines, between two different domestic lines, and within domestic lines - in contrast to the notion that domestic animals are highly inbred relative to their wild ancestors. In fact, most of the SNPs originated before domestication, and there is little evidence of selective sweeps for adaptive alleles on length scales greater than 100 kilobases
Anomaly analysis of Hawking radiation from Kaluza-Klein black hole with squashed horizon
Considering gravitational and gauge anomalies at the horizon, a new method
that to derive Hawking radiations from black holes has been developed by
Wilczek et al. In this paper, we apply this method to non-rotating and rotating
Kaluza-Klein black holes with squashed horizon, respectively. For the rotating
case, we found that, after the dimensional reduction, an effective U(1) gauge
field is generated by an angular isometry. The results show that the gauge
current and energy-momentum tensor fluxes are exactly equivalent to Hawking
radiation from the event horizon.Comment: 15 pages, no figures, the improved version, accepted by Eur. Phys. J.
Temperature-Dependent Infrared Reflectivity Studies of Multiferroic TbMnO_{3}: Evidence for Spin-Phonon Coupling
We have measured near normal incidence far infrared (FIR) reflectivity
spectra of a single crystal of TbMnO3 from 10K to 300K in the spectral range of
50 cm to 700 cm. Fifteen transverse optic (TO) and longitudinal
optic (LO) modes are identified in the imaginary part of the dielectric
function () and energy loss function
Im(-1/()), respectively. Some of the observed phonon modes
show anomalous softening below the magnetic transition temperature T (~
46K). We attribute this anomalous softening to the spin-phonon coupling caused
by phonon modulation of the super-exchange integral between the Mn
spins. The effective charge of oxygen (Z) calculated using the measured
LO-TO splitting increases below T.Comment: 16 pages, 6 figures, 1 tabl
Tear secretion dysfunction among women workers engaged in light-on tests in the TFT-LCD industry
BACKGROUND: The TFT-LCD (thin film transistor liquid crystal display) industry is rapidly growing in Taiwan and many other countries. A large number of workers, mainly women, are employed in the light-on test process to detect the defects of products. At the light-on test workstation, the operator is generally exposed to low humidity (in the clean room environment), flashing light, and low ambient illumination for long working hours. Many workers complained about eye discomfort, and therefore we conducted a study to evaluate the tear secretion function of light-on test workers of a TFT-LCD company. METHODS: We recruited workers engaged in light-on tests in the company during their periodical health examination. In addition to a questionnaire survey of demographic characteristics and ophthalmic symptoms, we evaluated the tear secretion function of both eyes of each participant using the Schirmer's lacrimal basal secretion test with anaesthesia. A participant with one or both eyes yielding abnormal test results was defined as a case of tear secretion dysfunction. RESULTS: During the study period, a total of 371 light-on test workers received the health examination at the clinic of the park, and 52 of them were excluded due to having ophthalmic diseases and other systemic diseases that may affect ophthalmic function. All the remaining 319 qualified workers agreed to participate in this study, and they were all females working by 4-shift rotations. The average age was 24.2 years old (standard deviation [SD] = 3.8), and the average employment duration was 13.6 months (SD = 5.7). Among the 11 ophthalmic symptoms evaluated, eye dryness was the most prevalent (prevalence = 43.3%). In addition, the prevalence of tear secretion dysfunction in at least one eye was 40.1% (128 cases), and contact lens users had an odds ratio of 1.73 (95% confidence interval = 1.02–2.94) in comparison with non-contact lens users. Comparing the Schirmer's test results of those who also participated in the screening in the previous year, we found 40 of the 156 participants (17.2%) with normal test results in the previous year turned abnormal in 2001. In contrast, only 21 of the 76 participants (9.1%) with abnormal test results in the previous year turned normal, and the difference was statistically significant (p = 0.02 for McNemar's test). CONCLUSION: The prevalence of tear secretion dysfunction in woman workers engaged in light-on tests is high and increases with a one-year duration of employment. The use of contact lens may further increase the risk
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