Systematic transcriptome wide analysis of lncRNA-miRNA interactions

Long noncoding RNAs (lncRNAs) are a recently discovered class of non-protein coding RNAs which have now increasingly been shown to be involved in a wide variety of biological processes as regulatory molecules. Little is known regarding the regulatory interactions between noncoding RNA classes. Recent reports have suggested that lncRNAs could potentially interact with other noncoding RNAs including miroRNAs (miRNAs) and modulate their regulatory role through interactions. We hypothesized that long noncoding RNAs could participate as a layer of regulatory interactions with miRNAs. The availability of genome-scale datasets for argonaute targets across human transcriptome has prompted us to reconstruct a genome-scale network of interactions between miRNAs and lncRNAs. We used well characterized experimental Photoactivatable-Ribonucleoside-Enhanced Crosslinking and Immunoprecipitation (PAR-CLIP) datasets and the recent genome-wide annotations for lncRNAs in public domain to construct a comprehensive transcriptome-wide map of miRNA regulatory elements. Comparative analysis revealed many of the miRNAs could target long noncoding RNAs, apart from the coding transcripts thus participating in a novel layer of regulatory interactions between noncoding RNA classes. We also find the miRNA regulatory elements have a positional preference, clustering towards the 3' and 5' ends of the long noncoding transcripts. We also further reconstruct a genome-wide map of miRNA interactions with lncRNAs as well as messenger RNAs. This analysis suggests widespread regulatory interactions between noncoding RNAs classes and suggests a novel functional role for lncRNAs. We also present the first transcriptome scale study on lncRNA-miRNA interactions and the first report of a genome-scale reconstruction of a noncoding RNA regulatory interactome involving lncRNAs

Real-time Spectroscopy with Sub-GHz Resolution using Amplified Dispersive Fourier Transformation

Dispersive Fourier transformation is a powerful technique in which spectral information is mapped into the time domain using chromatic dispersion. It replaces a spectrometer with an electronic digitizer, and enables real-time spectroscopy. The fundamental problem in this technique is the trade-off between the detection sensitivity and spectral resolution, a limitation set by the digitizer's bandwidth. This predicament is caused by the power loss associated with optical dispersion. We overcome this limitation using Raman amplified spectrum-to-time transformation. An extraordinary loss-less -11.76 ns/nm dispersive device is used to demonstrate single-shot gas absorption spectroscopy with 950 MHz resolution--a record in real-time spectroscopy.Comment: The following article has been accepted by Applied Physics Letter

Amplified Dispersive Fourier-Transform Imaging for Ultrafast Displacement Sensing and Barcode Reading

Dispersive Fourier transformation is a powerful technique in which the spectrum of an optical pulse is mapped into a time-domain waveform using chromatic dispersion. It replaces a diffraction grating and detector array with a dispersive fiber and single photodetector. This simplifies the system and, more importantly, enables fast real-time measurements. Here we describe a novel ultrafast barcode reader and displacement sensor that employs internally-amplified dispersive Fourier transformation. This technique amplifies and simultaneously maps the spectrally encoded barcode into a temporal waveform. It achieves a record acquisition speed of 25 MHz -- four orders of magnitude faster than the current state-of-the-art.Comment: Submitted to a journa

Electronic structure and electric-field gradients analysis in CeIn3CeIn_3

Electric field gradients (EFG's) were calculated for the $CeIn_3$ compound at both $^{115}In$ and $^{140}Ce$ sites. The calculations were performed within the density functional theory (DFT) using the augmented plane waves plus local orbital (APW+lo) method employing the so-called LDA+U scheme. The $CeIn_3$ compound were treated as nonmagnetic, ferromagnetic, and antiferromagnetic cases. Our result shows that the calculated EFG's are dominated at the $^{140}Ce$ site by the Ce-4f states. An approximately linear relation is intuited between the main component of the EFG's and total density of states (DOS) at Fermi level. The EFG's from our LDA+U calculations are in better agreement with experiment than previous EFG results, where appropriate correlations had not been taken into account among 4f-electrons. Our result indicates that correlations among 4f-electrons play an important role in this compound and must be taken into account

Extreme Value Statistics in Silicon Photonics

L-shape probability distributions are extremely non-Gaussian functions that have been surprisingly successful in describing the occurrence of extreme events ranging from stock market crashes, natural disasters, structure of biological systems, fractals, and optical rogue waves. We show that fluctuations in stimulated Raman scattering, as well as in coherent anti-Stokes Raman scattering, in silicon can follow extreme value statistics and provide mathematical insight into the origin of this behavior

Scale-free equilibria of self-gravitating gaseous disks with flat rotation curves

We introduce exact analytical solutions of the steady-state hydrodynamic equations of scale-free, self-gravitating gaseous disks with flat rotation curves. We express the velocity field in terms of a stream function and obtain a third-order ordinary differential equation (ODE) for the angular part of the stream function. We present the closed-form solutions of the obtained ODE and construct hydrodynamical counterparts of the power-law and elliptic disks, for which self-consistent stellar dynamical models are known. We show that the kinematics of the Large Magellanic Cloud can well be explained by our findings for scale-free elliptic disks.Comment: AAS preprint format, 21 pages, 8 figures, accepted for publication in The Astrophysical Journa

Noise figure and photon probability distribution in Coherent Anti-Stokes Raman Scattering (CARS)

The noise figure and photon probability distribution are calculated for coherent anti-Stokes Raman scattering (CARS) where an anti-Stokes signal is converted to Stokes. We find that the minimum noise figure is ~ 3dB.Comment: 2 page

Performance of serial time-encoded amplified microscope

Serial time-encoded amplified microscopy (STEAM) is an entirely new imaging modality that enables ultrafast continuous real-time imaging with high sensitivity. By means of optical image amplification, STEAM overcomes the fundamental tradeoff between sensitivity and speed that affects virtually all optical imaging systems. Unlike the conventional microscope systems, the performance of STEAM depends not only on the lenses, but also on the properties of other components that are unique to STEAM, namely the spatial disperser, the group velocity dispersion element, and the back-end electronic digitizer. In this paper, we present an analysis that shows how these considerations affect the spatial resolution, and how they create a trade-off between the number of pixels and the frame rate of the STEAM imager. We also quantify how STEAM's optical image amplification feature improves the imaging sensitivity. These analyses not only provide valuable insight into the operation of STEAM technology but also serve as a blue print for implementation and optimization of this new imaging technology. ©2010 Optical Society of America.published_or_final_versio