356 research outputs found
SCOPE: Scalable Composite Optimization for Learning on Spark
Many machine learning models, such as logistic regression~(LR) and support
vector machine~(SVM), can be formulated as composite optimization problems.
Recently, many distributed stochastic optimization~(DSO) methods have been
proposed to solve the large-scale composite optimization problems, which have
shown better performance than traditional batch methods. However, most of these
DSO methods are not scalable enough. In this paper, we propose a novel DSO
method, called \underline{s}calable \underline{c}omposite
\underline{op}timization for l\underline{e}arning~({SCOPE}), and implement it
on the fault-tolerant distributed platform \mbox{Spark}. SCOPE is both
computation-efficient and communication-efficient. Theoretical analysis shows
that SCOPE is convergent with linear convergence rate when the objective
function is convex. Furthermore, empirical results on real datasets show that
SCOPE can outperform other state-of-the-art distributed learning methods on
Spark, including both batch learning methods and DSO methods
A chalcone derivative reactivates latent HIV-1 transcription through activating P-TEFb and promoting Tat-SEC interaction on viral promoter.
The principal barrier to the eradication of HIV/AIDS is the existence of latent viral reservoirs. One strategy to overcome this barrier is to use latency-reversing agents (LRAs) to reactivate the latent proviruses, which can then be eliminated by effective anti-retroviral therapy. Although a number of LRAs have been found to reactivate latent HIV, they have not been used clinically due to high toxicity and poor efficacy. In this study, we report the identification of a chalcone analogue called Amt-87 that can significantly reactivate the transcription of latent HIV provirses and act synergistically with known LRAs such as prostratin and JQ1 to reverse latency. Amt-87 works by activating the human transcriptional elongation factor P-TEFb, a CDK9-cyclin T1 heterodimer that is part of the super elongation complex (SEC) used by the viral encoded Tat protein to activate HIV transcription. Amt-87 does so by promoting the phosphorylation of CDK9 at the T-loop, liberating P-TEFb from the inactive 7SK snRNP, and inducing the formation of the Tat-SEC complex at the viral promoter. Together, our data reveal chalcones as a promising category of compounds that should be further explored to identify effective LRAs for targeted reversal of HIV latency
Testing and Data Reduction of the Chinese Small Telescope Array (CSTAR) for Dome A, Antarctica
The Chinese Small Telescope ARray (hereinafter CSTAR) is the first Chinese
astronomical instrument on the Antarctic ice cap. The low temperature and low
pressure testing of the data acquisition system was carried out in a laboratory
refrigerator and on the 4500m Pamirs high plateau, respectively. The results
from the final four nights of test observations demonstrated that CSTAR was
ready for operation at Dome A, Antarctica. In this paper we present a
description of CSTAR and the performance derived from the test observations.Comment: Accepted Research in Astronomy and Astrophysics (RAA) 1 Latex file
and 20 figure
The linear and nonlinear Jaynes-Cummings model for the multiphoton transition
With the Jaynes-Cummings model, we have studied the atom and light field
quantum entanglement of multiphoton transition, and researched the effect of
initial state superposition coefficient , the transition photon number
, the quantum discord and the nonlinear coefficient on the
quantum entanglement degrees. We have given the quantum entanglement degrees
curves with time evolution, and obtained some results, which should have been
used in quantum computing and quantum information.Comment: arXiv admin note: text overlap with arXiv:1404.0821, arXiv:1205.0979
by other author
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