4,908 research outputs found
China-ASEAN Relations: Perspectives, Prospects, and Implications for U.S. Interests
The author traces the evolution of China-ASEAN relations since the early 1990s and examines some of the key factors that have contributed to the positive developments in bilateral ties. He describes and analyzes how China and ASEAN have managed the territorial disputes through negotiation and compromises; looks at the expanding economic ties between China and ASEAN member states and examines the politico-strategic, as well as economic rationales for establishing a free trade area; and evaluates the emerging yet still limited defense and security ties between the two. He also assesses the implications of the growing China-ASEAN ties for U.S. interests in the region.https://press.armywarcollege.edu/monographs/1707/thumbnail.jp
Determination of Dark Matter Halo Mass from Dynamics of Satellite Galaxies
We show that the mass of a dark matter halo can be inferred from the
dynamical status of its satellite galaxies. Using 9 dark-matter simulations of
halos like the Milky Way (MW), we find that the present-day substructures in
each halo follow a characteristic distribution in the phase space of orbital
binding energy and angular momentum, and that this distribution is similar from
halo to halo but has an intrinsic dependence on the halo formation history. We
construct this distribution directly from the simulations for a specific halo
and extend the result to halos of similar formation history but different
masses by scaling. The mass of an observed halo can then be estimated by
maximizing the likelihood in comparing the measured kinematic parameters of its
satellite galaxies with these distributions. We test the validity and accuracy
of this method with mock samples taken from the simulations. Using the
positions, radial velocities, and proper motions of 9 tracers and assuming
observational uncertainties comparable to those of MW satellite galaxies, we
find that the halo mass can be recovered to within 40%. The accuracy can
be improved to within 25% if 30 tracers are used. However, the dependence
of the phase-space distribution on the halo formation history sets a minimum
uncertainty of 20% that cannot be reduced by using more tracers. We
believe that this minimum uncertainty also applies to any mass determination
for a halo when the phase space information of other kinematic tracers is used.Comment: Accepted for publication in ApJ, 18 pages, 13 figure
DACH1 suppresses breast cancer as a negative regulator of CD44.
Dachshund homolog 1 (DACH1), a key cell fate determination factor, contributes to tumorigenesis, invasion, metastasis of human breast neoplasm. However, the exact molecular mechanisms for the anti-tumor roles of DACH1 in breast carcinoma are still lack of extensive understanding. Herein, we utilized immunohistochemistry (IHC) staining and public microarray data analysis showing that DACH1 was higher in normal breast, low-grade and luminal-type cancer in comparison with breast carcinoma, high-grade and basal-like tumors respectively. Additionally, both correlation analysis of public databases of human breast carcinoma and IHC analysis of mice xenograft tumors demonstrated that DACH1 inversely related to cancer stem cells (CSCs) markers, epithelial-mesenchymal transition (EMT) inducers and basal-enriched molecules, while cluster of differentiation 44 (CD44) behaved in an opposite manner. Furthermore, mice transplanted tumor model indicated that breast cancer cells Met-1 with up-regulation of DACH1 were endowed with remarkably reduced potential of tumorigenesis. Importantly, meta-analysis of 19 Gene Expression Omnibus (GEO) databases of breast cancer implicated that patients with higher DACH1 expression had prolonged time to death, recurrence and metastasis, while CD44 was a promising biomarker predicting worse overall survival (OS) and metastasis-free survival (MFS). Collectively, our study indicated that CD44 might be a novel target of DACH1 in breast carcinoma
A feedback-driven bubble G24.136+00.436: a possible site of triggered star formation
We present a multi-wavelength study of the IR bubble G24.136+00.436. The
J=1-0 observations of CO, CO and CO were carried out with
the Purple Mountain Observatory 13.7 m telescope. Molecular gas with a velocity
of 94.8 km s is found prominently in the southeast of the bubble,
shaping as a shell with a total mass of . It is
likely assembled during the expansion of the bubble. The expanding shell
consists of six dense cores. Their dense (a few of cm) and
massive (a few of ) characteristics coupled with the broad
linewidths ( 2.5 km s) suggest they are promising sites of forming
high-mass stars or clusters. This could be further consolidated by the
detection of compact HII regions in Cores A and E. We tentatively identified
and classified 63 candidate YSOs based on the \emph{Spitzer} and UKIDSS data.
They are found to be dominantly distributed in regions with strong emission of
molecular gas, indicative of active star formation especially in the shell. The
HII region inside the bubble is mainly ionized by a O8V star(s), of the
dynamical age 1.6 Myr. The enhanced number of candidate YSOs and
secondary star formation in the shell as well as time scales involved, indicate
a possible scenario of triggering star formation, signified by the "collect and
collapse" process.Comment: 13 pages, 10 figures, 4 tables, accepted by Ap
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