Transcriptional regulatory elements (TREs), including enhancers and promoters, determine the transcription levels of associated genes. We have recently shown that global run-on and sequencing (GRO-seq) with enrichment for 5'-capped RNAs reveals active TREs with high accuracy. Here, we demonstrate that active TREs can be identified by applying sensitive machine-learning methods to standard GRO-seq data. This approach allows TREs to be assayed together with gene expression levels and other transcriptional features in a single experiment. Our prediction method, called discriminative Regulatory Element detection from GRO-seq (dREG), summarizes GRO-seq read counts at multiple scales and uses support vector regression to identify active TREs. The predicted TREs are more strongly enriched for several marks of transcriptional activation, including eQTL, GWAS-associated SNPs, H3K27ac, and transcription factor binding than those identified by alternative functional assays. Using dREG, we survey TREs in eight human cell types and provide new insights into global patterns of TRE function.
We investigate a model of the interacting holographic dark energy with cold
dark matter (CDM). If the holographic energy density decays into CDM, we find
two types of the effective equation of state. In this case we have to use the
effective equations of state ($\omega^{\rm eff}_{\rm \Lambda}$) instead of the
equation of state ($\omega_{\rm \Lambda})$. For a fixed ratio of two energy
densities, their effective equations of state are given by the same negative
constant. Actually, the cosmic anti-friction arisen from the vacuum decay
process may induce the acceleration with $\omega^{\rm eff}_{\rm \Lambda}<-1/3$.
For a variable ratio, their effective equations of state are slightly
different, but they approach the same negative constant in the far future.
Consequently, we show that such an interacting holographic energy model cannot
accommodate a transition from the dark energy with $\omega^{\rm eff}_{\rm
\Lambda}\ge-1$ to the phantom regime with $\omega^{\rm eff}_{\rm \Lambda}<-1$.Comment: 11 pages, 2 eps figures, final version to appear in PL
We investigate the agegraphic dark energy models which were recently proposed
to explain the dark energy-dominated universe. For this purpose, we calculate
their equation of states and squared speeds of sound. We find that the squared
speed for agegraphic dark energy is always negative. This means that the
perfect fluid for agegraphic dark energy is classically unstable. Furthermore,
it is shown that the new agegraphic dark energy model could describe the matter
(radiation)-dominated universe in the far past only when the parameter $n$ is
chosen to be $n>n_c$, where the critical values are determined to be
$n_c=2.6878(2.5137752)$ numerically. It seems that the new agegraphic dark
energy model is no better than the holographic dark energy model for the
description of the dark energy-dominated universe, even though it resolves the
causality problem.Comment: 15 pages 4 figure
Contents (11 pages and 7 tables)Table S1. GC/MS peak areas of evolved compounds of reaction region during thermal and catalytic pyrolysis of cellulose.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.