668 research outputs found
High resolution photoemission study of YbAl3 at low temperature
The valence v and the 4f14-->4f137/4 transition energy TK of YbAl3 at low temperature were determined by the h igh resolution valence band photoemission spectroscopy. The obtained values v = 2.65+/-0.03 and TK=30+/-15 meV are consistent with the zero-temperature magnetic susceptibility [chi]m(0), supporting the Anderson Hamiltonian description for its electronic structure.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30796/1/0000450.pd
Probing the nature of high- z short GRB 090426 with its early optical and X-ray afterglows
GRB 090426 is a short-duration burst detected by Swift ( s in the observer frame and s in the burst frame at z = 2.609 ). Its host galaxy properties and some gamma-ray-related correlations are analogous to those seen in long-duration gamma-ray bursts (GRBs), which are believed to be of a massive star origin (so-called Type II GRBs). We present the results of its early optical observations with the 0.8-m Tsinghua University–National Astronomical Observatory of China Telescope (TNT) at Xinglong Observatory and the 1-m LOAO telescope at Mt Lemmon Optical Astronomy Observatory in Arizona. Our well-sampled optical afterglow light curve covers from to 10 4 s after the GRB trigger. It shows two shallow decay episodes that are likely due to energy injection, which end at and 7100 s, respectively. The decay slopes after the injection phases are consistent with each other ( ). The X-ray afterglow light curve appears to trace the optical, although the second energy-injection phase was missed due to visibility constraints introduced by the Swift orbit. The X-ray spectral index is without temporal evolution. Its decay slope is consistent with the prediction of the forward shock model. Both X-ray and optical emission are consistent with being in the same spectral regime above the cooling frequency ( ). The fact that is below the optical band from the very early epoch of the observation provides a constraint on the burst environment, which is similar to that seen in classical long-duration GRBs. We therefore suggest that death of a massive star is the possible progenitor of this short burst.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79209/1/j.1365-2966.2010.17419.x.pd
Probing the Nature of High-z Short GRB 090426 with Its Early Optical and X-ray Afterglows
GRB 090426 is a short duration burst detected by Swift ( s
in the observer frame, and s in the burst frame at
). Its host galaxy properties and some -ray related
correlations are analogous to those seen in long duration GRBs, which are
believed to be of a massive-star origin (so-called Type II GRBs). We present
the results of its early optical observations with the 0.8-m TNT telescope at
Xinglong observatory, and the 1-m LOAO telescope at Mt. Lemmon Optical
Astronomy Observatory in Arizona. Our well-sampled optical afterglow lightcurve
covers from seconds to seconds post the GRB trigger. It
shows two shallow decay episodes that are likely due to energy injection, which
end at seconds and seconds, respectively. The decay
slopes post the injection phases are consistent with each other (). The X-ray afterglow lightcurve appears to trace the optical, although
the second energy injection phase was missed due to visibility constraints
introduced by the {\em Swift} orbit. The X-ray spectral index is without temporal evolution. Its decay slope is consistent with the
prediction of the forward shock model. Both X-ray and optical emission is
consistent with being in the same spectral regime above the cooling frequency
(). The fact that is below the optical band from the very early
epoch of the observation provides a constraint on the burst environment, which
is similar to that seen in classical long duration GRBs. We therefore suggest
that death of a massive star is the possible progenitor of this short burst.Comment: 7 pages, 1 figures, 2 tables, revised version, MNRAS, in pres
Genomic Characterization Provides New Insights for Detailed Phage- Resistant Mechanism for Brucella abortus
As the causative agent of cattle brucellosis, Brucella abortus commonly exhibits smooth phenotype (by virtue of colony morphology) that is characteristically sensitive to specific Brucella phages, playing until recently a major role in taxonomical classification of the Brucella species by the phage typing approach. We previously reported the discrepancy between traditional phenotypic typing and MLVA results of a smooth phage-resistant (SPR) strain Bab8416 isolated from a 45-year-old custodial worker with brucellosis in a cattle farm. Here, we performed whole genome sequencing and further obtained a complete genome sequence of strain Bab8416 by a combination of multiple NGS technologies and routine PCR sequencing. The detailed genetic differences between B. abortus SPR Bab8416 and large smooth phage-sensitive (SPS) strains were investigated in a comprehensively comparative genomic study. The large indels between B. abortus SPS strains and Bab8416 showed possible divergence between two evolutionary branches at a far phylogenetic node. Compared to B. abortus SPS strain 9-941 (Bab9-941), the specific re-arrangement event in Bab8416 displaying a closer linear relationship with B. melitensis 16M than other B. abortus strains resulted in the truncation of c-di-GMP synthesis, and 3 c-di-GMP-metabolizing genes, were present in Bab8416 and B. melitensis 16M, but absent in Bab9-941 and other B. abortus strains, indicating potential SPR-associated key determinants and novel molecular mechanisms. Moreover, despite almost completely intact smooth LPS related genes, only one mutated OmpA family protein of Bab8416, functionally related to flagellar and efflux pump, was newly identified. Several point mutations were identified to be Bab8416 specific while a majority of them were verified to be B. abortus ST2 characteristic. In conclusion, our study therefore identifies new SPR-associated factors that could play a role in refining and updating Brucella taxonomic schemes and provides resources for further detailed analysis of mechanism for Brucella phage resistance
Probing the nature of high-z short GRB 090426 with its early optical and X-ray afterglows MNRAS 410
ABSTRACT GRB 090426 is a short-duration burst detected by Swift (T 90 ∼ 1.28 s in the observer frame and T 90 ∼ 0.33 s in the burst frame at z = 2.609). Its host galaxy properties and some gamma-rayrelated correlations are analogous to those seen in long-duration gamma-ray bursts (GRBs), which are believed to be of a massive star origin (so-called Type II GRBs). We present the results of its early optical observations with the 0.8-m Tsinghua University-National Astronomical Observatory of China Telescope (TNT) at Xinglong Observatory and the 1-m LOAO telescope at Mt Lemmon Optical Astronomy Observatory in Arizona. Our wellsampled optical afterglow light curve covers from ∼90 to 10 4 s after the GRB trigger. It shows two shallow decay episodes that are likely due to energy injection, which end at ∼230 and 7100 s, respectively. The decay slopes after the injection phases are consistent with each other (α 1.22). The X-ray afterglow light curve appears to trace the optical, although the second energy-injection phase was missed due to visibility constraints introduced by the Swift orbit. The X-ray spectral index is β X ∼ 1.0 without temporal evolution. Its decay slope is consistent with the prediction of the forward shock model. Both X-ray and optical emission are consistent with being in the same spectral regime above the cooling frequency (ν c ). The fact that ν c is below the optical band from the very early epoch of the observation provides a constraint on the burst environment, which is similar to that seen in classical long-duration GRBs. We therefore suggest that death of a massive star is the possible progenitor of this short burst
A Robust Approach to Identifying Tissue-Specific Gene Expression Regulatory Variants Using Personalized Human Induced Pluripotent Stem Cells
Normal variation in gene expression due to regulatory polymorphisms is often masked by biological and experimental noise. In addition, some regulatory polymorphisms may become apparent only in specific tissues. We derived human induced pluripotent stem (iPS) cells from adult skin primary fibroblasts and attempted to detect tissue-specific cis-regulatory variants using in vitro cell differentiation. We used padlock probes and high-throughput sequencing for digital RNA allelotyping and measured allele-specific gene expression in primary fibroblasts, lymphoblastoid cells, iPS cells, and their differentiated derivatives. We show that allele-specific expression is both cell type and genotype-dependent, but the majority of detectable allele-specific expression loci remains consistent despite large changes in the cell type or the experimental condition following iPS reprogramming, except on the X-chromosome. We show that our approach to mapping cis-regulatory variants reduces in vitro experimental noise and reveals additional tissue-specific variants using skin-derived human iPS cells
Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector
Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
Protein kinase C and cardiac dysfunction: a review
Heart failure (HF) is a physiological state in which cardiac output is insufficient to meet the needs of the body. It is a clinical syndrome characterized by impaired ability of the left ventricle to either fill or eject blood efficiently. HF is a disease of multiple aetiologies leading to progressive cardiac dysfunction and it is the leading cause of deaths in both developed and developing countries. HF is responsible for about 73,000 deaths in the UK each year. In the USA, HF affects 5.8 million people and 550,000 new cases are diagnosed annually. Cardiac remodelling (CD), which plays an important role in pathogenesis of HF, is viewed as stress response to an index event such as myocardial ischaemia or imposition of mechanical load leading to a series of structural and functional changes in the viable myocardium. Protein kinase C (PKC) isozymes are a family of serine/threonine kinases. PKC is a central enzyme in the regulation of growth, hypertrophy, and mediators of signal transduction pathways. In response to circulating hormones, activation of PKC triggers a multitude of intracellular events influencing multiple physiological processes in the heart, including heart rate, contraction, and relaxation. Recent research implicates PKC activation in the pathophysiology of a number of cardiovascular disease states. Few reports are available that examine PKC in normal and diseased human hearts. This review describes the structure, functions, and distribution of PKCs in the healthy and diseased heart with emphasis on the human heart and, also importantly, their regulation in heart failure
2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation: executive summary.
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