14 research outputs found
Nucleic Acids Res
Micro (mi)RNAs are small non-coding RNAs with key regulatory functions. Recent advances in the field allowed researchers to identify their targets. However, much less is known regarding the regulation of miRNAs themselves. The accumulation of these tiny regulators can be modulated at various levels during their biogenesis from the transcription of the primary transcript (pri-miRNA) to the stability of the mature miRNA. Here, we studied the importance of the pri-miRNA secondary structure for the regulation of mature miRNA accumulation. To this end, we used the Kaposi's sarcoma herpesvirus, which encodes a cluster of 12 pre-miRNAs. Using small RNA profiling and quantitative northern blot analysis, we measured the absolute amount of each mature miRNAs in different cellular context. We found that the difference in expression between the least and most expressed viral miRNAs could be as high as 60-fold. Using high-throughput selective 2'-hydroxyl acylation analyzed by primer extension, we then determined the secondary structure of the long primary transcript. We found that highly expressed miRNAs derived from optimally structured regions within the pri-miRNA. Finally, we confirmed the importance of the local structure by swapping stem-loops or by targeted mutagenesis of selected miRNAs, which resulted in a perturbed accumulation of the mature miRNA
New current mode biquadratic active filters employing currentdifference amplifiers
A new configuration for realization of current mode active filters is presented. It can synthesize current-mode second-order allpass, bandpass, highpass, lowpass and band-eliminate filter sections using a single current difference (Norton) amplifier and at most seven passive RC one-port element
THE NEEDLE in the 100 deg<sup>2</sup> HAYSTACK: UNCOVERING AFTERGLOWS of FERMI GRB<inf>s</inf> with the PALOMAR TRANSIENT FACTORY
The Fermi Gamma-ray Space Telescope has greatly expanded the number and energy window of observations of gamma-ray bursts (GRBs). However, the coarse localizations of tens to a hundred square degrees provided by the Fermi GRB Monitor instrument have posed a formidable obstacle to locating the bursts' host galaxies, measuring their redshifts, and tracking their panchromatic afterglows. We have built a target-of-opportunity mode for the intermediate Palomar Transient Factory in order to perform targeted searches for Fermi afterglows. Here, we present the results of one year of this program: 8 afterglow discoveries out of 35 searches. Two of the bursts with detected afterglows (GRBs 130702A and 140606B) were at low redshift (z = 0.145 and 0.384, respectively) and had spectroscopically confirmed broad-line Type Ic supernovae. We present our broadband follow-up including spectroscopy as well as X-ray, UV, optical, millimeter, and radio observations. We study possible selection effects in the context of the total Fermi and Swift GRB samples. We identify one new outlier on the Amati relation. We find that two bursts are consistent with a mildly relativistic shock breaking out from the progenitor star rather than the ultra-relativistic internal shock mechanism that powers standard cosmological bursts. Finally, in the context of the Zwicky Transient Facility, we discuss how we will continue to expand this effort to find optical counterparts of binary neutron star mergers that may soon be detected by Advanced LIGO and Virgo. © 2015. The American Astronomical Society. All rights reserved
Recent developments in the household saving ratio
SUMMARYThe household saving ratio summarises the income and expenditure positions of the household sector. This article considers developments in the ratio during the current recession, discussing the drivers in income and consumption and their interaction in the context of developments in the labour market, government policy and wider economic conditions.
Monitoring the coherence between ONS and PMI data - an update
SummaryIn the last couple of years there has been strong interest in economic statistics as the UK economy recovers from its deepest post war recession. This article updates previous work examining the coherence between official economic data published by the Office for National Statistics and widely-used business survey data in the form of the Purchasing Managers Index to include this latest period.