9,274 research outputs found
[Review of] Bill Ong Hing. Making and Remaking Asian America Through Immigration Policy
Bill Ong Hing\u27s book has fulfilled a long-felt need in Asian American studies. Since the publication of Milton R. Konvitz\u27s The Alien and Asiatic in American Law (1946), no comprehensive overview of how American immigration policy influenced Asian immigration has been published. The subject, however, represents one of the most important aspects of Asian American experience. Historically, the anti-Asiatic Exclusion Laws played a defining role in the evolution of Asian America. Today, the legacy of racist immigration policies continue to limit Asian Americans, and the current debate over immigration remains an issue of great importance for the communities
Next-to-leading order QCD corrections to the single top quark production via model-independent t-q-g flavor-changing neutral-current couplings at hadron colliders
We present the calculations of the complete next-to-leading order (NLO) QCD
effects on the single top productions induced by model-independent
flavor-changing neutral-current couplings at hadron colliders. Our results show
that, for the coupling the NLO QCD corrections can enhance the total
cross sections by about 60% and 30%, and for the coupling by about 50%
and 20% at the Tevatron and LHC, respectively, which means that the NLO
corrections can increase the experimental sensitivity to the FCNC couplings by
about 10%30%. Moreover, the NLO corrections reduce the dependence of the
total cross sections on the renormalization or factorization scale
significantly, which lead to increased confidence on the theoretical
predictions. Besides, we also evaluate the NLO corrections to several important
kinematic distributions, and find that for most of them the NLO corrections are
almost the same and do not change the shape of the distributions.Comment: minor changes, version published in PR
Associated production of the top-pions and single top at hadron colliders
In the context of topcolor assisted technicolor(TC2) models, we study the
production of the top-pions with single top quark via the
processes and ,
and discuss the possibility of detecting these new particles at Tevatron and
LHC. We find that it is very difficult to observe the signals of these
particles via these processes at Tevatron, while the neutral and charged
top-pions and can be detecting via considering
the same sign top pair event and the (or )
event at LHC, respectively.Comment: latex files,14 pages, 7 figures. Accepted for publication in Phys.
Rev.
Coupled Reversible and Irreversible Bistable Switches Underlying TGF-\beta-induced Epithelial to Mesenchymal Transition
Epithelial to mesenchymal transition (EMT) plays important roles in embryonic
development, tissue regeneration and cancer metastasis. While several feedback
loops have been shown to regulate EMT, it remains elusive how they coordinately
modulate EMT response to TGF-\beta treatment. We construct a mathematical model
for the core regulatory network controlling TGF-\beta-induced EMT. Through
deterministic analyses and stochastic simulations, we show that EMT is a
sequential two-step program that an epithelial cell first transits to partial
EMT then to the mesenchymal state, depending on the strength and duration of
TGF-\beta stimulation. Mechanistically the system is governed by coupled
reversible and irreversible bistable switches. The SNAIL1/miR-34 double
negative feedback loop is responsible for the reversible switch and regulates
the initiation of EMT, while the ZEB/miR-200 feedback loop is accountable for
the irreversible switch and controls the establishment of the mesenchymal
state. Furthermore, an autocrine TGF-\beta/miR-200 feedback loop makes the
second switch irreversible, modulating the maintenance of EMT. Such coupled
bistable switches are robust to parameter variation and molecular noise. We
provide a mechanistic explanation on multiple experimental observations. The
model makes several explicit predictions on hysteretic dynamic behaviors,
system response to pulsed stimulation and various perturbations, which can be
straightforwardly tested.Comment: 32 pages, 8 figures, accepted by Biophysical Journa
Diphoton excess at 750 GeV: gluon-gluon fusion or quark-antiquark annihilation?
Recently, ATLAS and CMS collaboration reported an excess in the diphoton
events, which can be explained by a new resonance with mass around 750 GeV. In
this work, we explored the possibility of identifying if the hypothetical new
resonance is produced through gluon-gluon fusion or quark-antiquark
annihilation, or tagging the beam. Three different observables for beam
tagging, namely the rapidity and transverse momentum distribution of the
diphoton, and one tagged bottom-jet cross section, are proposed. Combining the
information gained from these observables, a clear distinction of the
production mechanism for the diphoton resonance is promising.Comment: 20 pages, 7 figure
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