360 research outputs found
Reply to 'Comment on 'Heavy element production in inhomogeneous big bang nucleosynthesis''
This is a reply report to astro-ph/0604264. We studied heavy element
production in high baryon density region in early universe astro-ph/0507439.
However it is claimed in astro-ph/0604264 that small scale but high baryon
density region contradicts observations for the light element abundance or in
order not to contradict to observations high density region must be so small
that it cannot affect the present heavy element abundance.
In this paper we study big bang nucleosynthesis in high baryon density region
and show that in certain parameter spaces it is possible to produce enough
amount of heavy element without contradiction to CMB and light element
observations.Comment: 7 pages, 4 figures, References added, one more reference adde
Search for Near-Infrared Pulsation of the Anomalous X-ray Pulsar 4U 0142+61
We have searched for pulsation of the anomalous X-ray pulsar (AXP) 4U 0142+61
in the K' band ( m) using the fast-readout mode
of IRCS at the Subaru 8.2-m telescope. We found no significant signal at the
pulse frequency expected by the precise ephemeris obtained by the X-ray
monitoring observation with RXTE. Nonetheless, we obtained a best upper limit
of 17% (90% C.L.) for the root-mean-square pulse fraction in the K' band.
Combined with i' band pulsation (Dhillon et al. 2005), the slope of the pulsed
component () was constrained to (90%
C.L.) for an interstellar extinction of .Comment: 11 pages, 3 figures, Accepted for publication in PAS
Stability of Bose-Einstein condensates in a Kronig-Penney potential
We study the stability of Bose-Einstein condensates with superfluid currents
in a one-dimensional periodic potential. By using the Kronig-Penney model, the
condensate and Bogoliubov bands are analytically calculated and the stability
of condensates in a periodic potential is discussed. The Landau and dynamical
instabilities occur in a Kronig-Penney potential when the quasimomentum of the
condensate exceeds certain critical values as in a sinusoidal potential. It is
found that the onsets of the Landau and dynamical instabilities coincide with
the point where the perfect transmission of low energy excitations through each
potential barrier is forbidden. The Landau instability is caused by the
excitations with small and the dynamical instability is caused by the
excitations with at their onsets, where is the quasimomentum of
excitation and is the lattice constant. A swallow-tail energy loop appears
at the edge of the first condensate band when the mean-field energy is
sufficiently larger than the strength of the periodic potential. We find that
the upper portion of the swallow-tail is always dynamically unstable, but the
second Bogoliubov band has a phonon spectrum reflecting the positive effective
mass.Comment: 32 pages, 21 figure
Holographic phase transitions at finite baryon density
We use holographic techniques to study SU(Nc) super Yang-Mills theory coupled
to Nf << Nc flavours of fundamental matter at finite temperature and baryon
density. We focus on four dimensions, for which the dual description consists
of Nf D7-branes in the background of Nc black D3-branes, but our results apply
in other dimensions as well. A non-zero chemical potential mu or baryon number
density n is introduced via a nonvanishing worldvolume gauge field on the
D7-branes. Ref. [1] identified a first order phase transition at zero density
associated with `melting' of the mesons. This extends to a line of phase
transitions for small n, which terminates at a critical point at finite n.
Investigation of the D7-branes' thermodynamics reveals that (d mu / dn)_T <0 in
a small region of the phase diagram, indicating an instability. We comment on a
possible new phase which may appear in this region.Comment: 33 pages, 22 figure
Short recipient warm ischemia time improves outcomes in deceased donor liver transplantation
While adverse effects of prolonged recipient warm ischemia time (rWIT) in liver transplantation (LT) have been well investigated, few studies have focused on possible positive prognostic effects of short rWIT. We aim to investigate if shortening rWIT can further improve outcomes in donation after brain death liver transplant (DBD-LT). Primary DBD-LT between 2000 and 2019 were retrospectively reviewed. Patients were divided according to rWIT (≤30, 31-40, 41-50, and \u3e50 min). The requirement of intraoperative transfusion, early allograft dysfunction (EAD), and graft survival were compared between the rWIT groups. A total of 1,256 patients of DBD-LTs were eligible. rWIT was ≤30min in 203 patients (15.7%), 31-40min in 465 patients (37.3%), 41-50min in 353 patients (28.1%), and \u3e50min in 240 patients (19.1%). There were significant increasing trends of transfusion requirement (P \u3c 0.001) and increased estimated blood loss (EBL, P \u3c 0.001), and higher lactate level (P \u3c 0.001) with prolongation of rWIT. Multivariable logistic regression demonstrated the lowest risk of EAD in the WIT ≤30min group. After risk adjustment, patients with rWIT ≤30 min showed a significantly lower risk of graft loss at 1 and 5-years, compared to other groups. The positive prognostic impact of rWIT ≤30min was more prominent when cold ischemia time exceeded 6 h. In conclusion, shorter rWIT in DBD-LT provided significantly better post-transplant outcomes
Subaru Spectropolarimetry of Mrk 573: The Hidden High-Ionization Nuclear Emission-Line Region inside the Dusty Torus
We report on the result of our high quality spectropolarimetric observation
for the narrow-line region in a nearby Seyfert 2 galaxy, Mrk 573, by the Subaru
Telescope. The polarized flux spectrum of Mrk 573 shows not only prominent
scattered broad H emission but also various narrow forbidden emission
lines. We find that the measured polarization degree of the observed forbidden
emission lines is positively correlated with the ionization potential of the
corresponding ions and the critical density of the corresponding transitions.
We discuss some possible origins of these correlations, and then we point out
that the correlations are caused due to the obscuration of the stratified
narrow-line region in Mrk 573 by the optically and geometrically thick dusty
torus, just similar to the previous study on NGC 4258.Comment: 10 pages including 8 figures, to appear in The Astronomical Journa
Multiple early gastric cancer with duodenal invasion
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Pink-Colored Grape Berry Is the Result of Short Insertion in Intron of Color Regulatory Gene
We report here that pink grape berries were obtained by a short insertion in the intron of the MybA1 gene, a gene that regulates grape berry color. Genetic variation was detected among the MybA1 genes from grapes cultivated worldwide. PCR analysis of the MybA1 gene demonstrated that the size of the MybA1 gene in the red allele differs among grapes. Oriental V. vinifera bearing pink berries has the longest MybA1 gene among grapes, whereas the shortest MybA1 gene was detected in occidental V. vinifera grapes. The nucleotide sequences of the MybA1 genes demonstrated that oriental V. vinifera has two additional gene fragments (44 bp and 111 bp) in the promoter region of the MybA1 gene in the red allele and another 33 bp fragment in the second intron of the MybA1 gene in the red allele. The short insertion in the intron decreased the transcription activity in the model system and retained MybA1 transcripts with unspliced intron in the total RNA. From the experiments using deletion mutants of the 33 bp short insertion, 16 bp of the 3′ end in the insertion is a key structure for a defect in splicing of MybA1 transcripts. Thus, a weakly colored grape berry might be a result of the short insertion in the intron of a color regulatory gene. This is new evidence concerning the molecular mechanism of the fate of grape berry color. These findings are expected to contribute to the further understanding of the color variation in grape berries, which is correlated with the evolutional events occurring in the MybA1 gene of grapes
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