399 research outputs found
Ammonia mapping observations of the Galactic infrared bubble N49: Three NH clumps along the molecular filament
We have carried out the NH and mapping
observations toward the Galactic infrared bubble N49 (G28.83-0.25) using the
Nobeyama 45 m telescope. Three NH clumps (A, B, and C) were discovered
along the molecular filament with the radial velocities of 96, 87, and
89 km s, respectively. The kinetic temperature derived from the NH
(2,2)/NH (1,1) shows K enhanced at Clump B in
the eastern edge of the bubble, where position coincides with massive young
stellar objects (MYSOs) associated with the 6.7 GHz class II methanol maser
source. This result shows the dense clump is locally heated by stellar feedback
from the embedded MYSOs. The NH Clump B also exists at the 88 km s
and 95 km s molecular filament intersection. We therefore suggest that
the NH dense gas formation in Clump B can be explained by a
filament-filament interaction scenario. On the other hand, NH Clump A and C
at the northern and southern side of the molecular filament might be the sites
of spontaneous star formation because these clumps are located 510 pc
away from the edge of the bubble.Comment: 29 pages, 13 figures, 3 tables, accepted for Publications of the
Astronomical Society of Japan (PASJ
Hagedorn Strings and Correspondence Principle in AdS(3)
Motivated by the possibility of formulating a strings/black hole
correspondence in AdS space, we extract the Hagedorn behavior of thermal AdS_3
bosonic string from 1-loop partition function of SL(2,R) WZW model. We find
that the Hagedorn temperature is monotonically increasing as the AdS radius
shrinks, reaches a maximum of order of string scale set by the unitarity bound
of the CFT for internal space. The resulting density of states near the
Hagedorn temperature resembles the form as for strings in flat space and is
dominated by the space-like long string configurations. We then argue a
conjectured strings/black hole correspondence in AdS space by applying the
Hagedorn thermodynamics. We find the size of the corresponding black hole is a
function of the AdS radius. For large AdS radius a black hole far bigger than
the string scale will form. On the contrary, when the AdS and string scales are
comparable a string size black hole will form. We also examine strings on BTZ
background obtained through SL(2,Z) transformation. We find a tachyonic
divergence for a BTZ black hole of string scale size.Comment: 28 pages, 4 figures;v2 references added & appear on JHE
Vortex Lattice Structures of a Bose-Einstein Condensate in a Rotating Lattice Potential
We study vortex lattice structures of a trapped Bose-Einstein condensate in a
rotating lattice potential by numerically solving the time-dependent
Gross-Pitaevskii equation. By rotating the lattice potential, we observe the
transition from the Abrikosov vortex lattice to the pinned lattice. We
investigate the transition of the vortex lattice structure by changing
conditions such as angular velocity, intensity, and lattice constant of the
rotating lattice potential.Comment: 6 pages, 8 figures, submitted to Quantum Fluids and Solids Conference
(QFS 2006
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Photodynamic activation as a molecular switch to promote osteoblast cell differentiation via AP-1 activation
In photodynamic therapy (PDT), cells are impregnated with a photosensitizing agent that is activated by light irradiation, thereby photochemically generating reactive oxygen species (ROS). The amounts of ROS produced depends on the PDT dose and the nature of the photosensitizer. Although high levels of ROS are cytotoxic, at physiological levels they play a key role as second messengers in cellular signaling pathways, pluripotency, and differentiation of stem cells. To investigate further the use of photochemically triggered manipulation of such pathways, we exposed mouse osteoblast precursor cells and rat primary mesenchymal stromal cells to low-dose PDT. Our results demonstrate that low-dose PDT can promote osteoblast differentiation via the activation of activator protein-1 (AP-1). Although PDT has been used primarily as an anti-cancer therapy, the use of light as a photochemical “molecular switch” to promote differentiation should expand the utility of this method in basic research and clinical applications
Drag force in SYM plasma with B field from AdS/CFT
We investigate drag force in a thermal plasma of N=4 super Yang-Mills theory
via both fundamental and Dirichlet strings under the influence of non-zero NSNS
-field background. In the description of AdS/CFT correspondence the endpoint
of these strings correspondes to an external monopole or quark moving with a
constant electromagnetic field. We demonstrate how the configuration of string
tail as well as the drag force obtains corrections in this background.Comment: 13 pages, 2 figures, more discussion and reference adde
Case Report Sequential MR Images and Radiographs of Epiphyseal Osteomyelitis in the Distal Femur of an Infant
Magnetic resonance imaging (MRI) plays an important role in the diagnosis of osteomyelitis, especially during the early phase of the disease. The findings of sequential MRIs during the course of treatment in acute osteomyelitis in children have not yet been reported in the literature. We present a case of acute epiphyseal osteomyelitis in the distal femur of an infant. We monitored imaging changes by sequential MRIs and radiographs. MRI was more useful than radiograph for early diagnosis and evaluation of therapeutic response
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