9,800 research outputs found
Reprocessed emission from warped accretion discs induced by the Bardeen-Petterson effect
The broad Balmer emission-line profiles resulting from the reprocessing of
UV/X-ray radiation from a warped accretion disc induced by the
Bardeen-Petterson effect are studied. We adopt a thin warped disc geometry and
a central ring-like illuminating source in our model. We compute the
steady-state shape of the warped disc numerically, and then use it in the
calculation of the line profile. We find that, from the outer radius to the
inner radius of the disc, the warp is twisted by an angle of before
being flattened efficiently into the equatorial plane. The profiles obtained
depend weakly on the illuminating source radius in the range from to
, but depend strongly on this radius when it approaches the marginally
stable orbit of an extreme Kerr black hole. Double- or triplet-peaked line
profiles are present in most cases when the illuminating source radius is low.
The triplet-peaked line profiles observed from the Sloan Digital Sky Survey may
be a {"}signature" of a warped disc.Comment: 8 pages, 6 figures, typos corrected, matches version to appear in
MNRA
Potential Application of the CRISPR/Cas9 System against Herpesvirus Infections.
The CRISPR/Cas9 system has been applied in the genome editing and disruption of latent infections for herpesviruses such as the herpes simplex virus, Epstein⁻Barr virus, cytomegalovirus, and Kaposi's sarcoma-associated herpesvirus. CRISPR/Cas9-directed mutagenesis can introduce similar types of mutations to the viral genome as can bacterial artificial chromosome recombination engineering, which maintains and reconstitutes the viral genome successfully. The cleavage mediated by CRISPR/Cas9 enables the manipulation of disease-associated viral strains with unprecedented efficiency and precision. Additionally, current therapies for herpesvirus productive and latent infections are limited in efficacy and cannot eradicate viruses. CRISPR/Cas9 is potentially adapted for antiviral treatment by specifically targeting viral genomes during latent infections. This review, which focuses on recently published progress, suggests that the CRISPR/Cas9 system is not only a useful tool for basic virology research, but also a promising strategy for the control and prevention of herpesvirus latent infections
-almost periodic and almost periodic solutions for some nonlinear integral equations
In this paper, we investigate the existence of -almost periodic solution for a class of nonlinear Fredholm integral equations, and the existence of almost periodic solution for a class of nonlinear functional integral equations. Our existence theorems extend some earlier results. Two examples are given to illustrate our results
Antiarrhythmic and proarrhythmic effects of subcutaneous nerve stimulation in ambulatory dogs
Background
High output subcutaneous nerve stimulation (ScNS) remodels the stellate ganglia and suppresses cardiac arrhythmia.
Objective
To test the hypothesis that long duration low output ScNS causes cardiac nerve sprouting, increases plasma norepinephrine concentration and the durations of paroxysmal atrial tachycardia (PAT) in ambulatory dogs.
Methods
We prospectively randomized 22 dogs (11 males and 11 females) into 5 different output groups for 2 months of ScNS: 0 mA (sham) (N=6), 0.25 mA (N=4), 1.5 mA (N=4), 2.5 mA (N=4) and 3.5 mA (N=4).
Results
As compared with baseline, the changes of the durations of PAT episodes per 48 hours were significantly different among different groups (sham, -5.0±9.5 s; 0.25 mA 95.5±71.0 s; 1.5 mA, -99.3±39.6 s; 2.5 mA, -155.3±87.8 s and 3.5 mA, -76.3±44.8 s, p<0.001). The 3.5 mA group had greater reduction of sinus heart rate than the sham group (-29.8±15.0 bpm vs -14.5±3.0 bpm, p=0.038). Immunohistochemical studies showed that the 0.25 mA group had a significantly increased while 2.5 mA and 3.5 mA stimulation had a significantly reduced growth-associated protein 43 nerve densities in both atria and ventricles. The plasma Norepinephrine concentrations in 0.25 mA group was 5063.0±4366.0 pg/ml, which was significantly higher than other groups of dogs (739.3±946.3, p=0.009). There were no significant differences in the effects of simulation between males and females.
Conclusions
In ambulatory dogs, low output ScNS causes cardiac nerve sprouting, increases plasma norepinephrine concentration and the duration of PAT episodes while high output ScNS is antiarrhythmic
The contributions of components to the axial charges of proton and its resonances
We calculate the axial charges of the proton and its resonances in the
framework of the constituent quark model, which is extended to include the
components. If 20% admixtures of the components in
the proton are assumed, the theoretical value for the axial charge in our model
is in good agreement with the empirical value, which can not be well reproduced
in the traditional constituent quark model even though the symmetry breaking or relativistic effect is taken into account. We also
predict an unity axial charge for with 30%
components constrained by the strong and electromagnetic decays.Comment: 4 pages, 4 table
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