29 research outputs found
Identification of H3K4me1-associated proteins at mammalian enhancers.
Enhancers act to regulate cell-type-specific gene expression by facilitating the transcription of target genes. In mammalian cells, active or primed enhancers are commonly marked by monomethylation of histone H3 at lysine 4 (H3K4me1) in a cell-type-specific manner. Whether and how this histone modification regulates enhancer-dependent transcription programs in mammals is unclear. In this study, we conducted SILAC mass spectrometry experiments with mononucleosomes and identified multiple H3K4me1-associated proteins, including many involved in chromatin remodeling. We demonstrate that H3K4me1 augments association of the chromatin-remodeling complex BAF to enhancers in vivo and that, in vitro, H3K4me1-marked nucleosomes are more efficiently remodeled by the BAF complex. Crystal structures of the BAF component BAF45C indicate that monomethylation, but not trimethylation, is accommodated by BAF45C's H3K4-binding site. Our results suggest that H3K4me1 has an active role at enhancers by facilitating binding of the BAF complex and possibly other chromatin regulators
Neutrinos as Source of Ultra High Energy Cosmic Rays in Extra Dimensions
If the neutrinos are to be identified with the primary source of ultra-high
energy cosmic rays(UHECR), their interaction on relic neutrinos is of great
importance in understanding their long intergalactic journey. In theories with
large compact dimensions, the exchange of a tower of massive spin-2 gravitons
(Kaluza-Klein excitations) gives extra contribution to and processes along with the opening
of a new channel for the neutrinos to annihilate with the relic cosmic neutrino
background to produce bulk gravitons in
the extra dimensions. This will affect their attenuation. We compute the
contribution of these Kaluza-Klein excitations to the above processes and find
that for parameters of the theory constrained by supernova cooling, the
contribution does indeed become the dominant contribution above GeV.Comment: 16 pages Latex2e file including 4 postscript figures. Effect of brane
fluctuation taken into accoun
missing energy in models with large extra dimensions
We study the neutral current flavour changing rare decay mode
missing energy within the framework of theories with large extra spatial
dimensions. The corresponding Standard Model signature is . But in theories with large extra dimensions, it is possible to have
scalars and gravitons in the final state making it quite distinct from any
other scenario where there are no gravitons and the scalars are far too heavier
than the B-meson to be present as external particles. We give an estimate of
the branching ratio for such processes for different values of the number of
extra dimensions and the effective scale of the effective theory.Comment: 12 page latex file including 4 eps figures. Details of calculation
and references added. Version to appear in PR
in NonCommutative Standard Model
We study the top quark decay to b quark and W boson in the NonCommutative
Standard Model (NCSM). The lowest contribution to the decay comes from the
terms quadratic in the matrix describing the noncommutative (NC) effects while
the linear term is seen to identically vanish because of symmetry. The NC
effects are found to be significant only for low values of the NC
characteristic scale.Comment: 11 page Latex file containing 2 eps figures (redrawn). More
discussion included. To appear in PR
Two Bit Arithmetic Logic Unit (ALU) in QCA
Abstract âQuantum cellular automata (QCA) is a new technology in nanometre scale (<18nm) to support nano technology. QCA is very effective in terms of high space density and power dissipation and will be playing a major role in the development of the Quantum computer with low power consumption and high speed. This paper describes the design and layout of a 2-bit ALU based on quantum-dot cellular automata (QCA) using the QCADesigner design tool. The ALU design is based on combinational circuits which reduces the required hard-ware complexity and allows for reasonable simulation times. The paper aims to provide evidence that QCA has potential applications in future Quantum computers, provided that the underlying technology is made feasible. Design has been made using certain combinational circuits by using Majority gate, AND, OR, NOT, X-OR in QCA. 2 bit ALU needs the design of Logical Extender, Arithmetic Extender and the Full adder circuits using QCA. The QCA is a novel tool to realize Nano level digital devices and study and analyze their various parameters. To date, proof of concept QCA cells have been experimentally verified using a device which exploits the Coulomb blockade phenomenon [10], although the originally proposed cell is still beyond present fabrication capabilities. As a result, investigators are currently looking at creating QCA cells using single molecules [11]
Epidemiology of acute decompensated heart failure in India : The AFAR study (Acute failure registry study)
Objectives: There is a paucity of data on acute decompensated heart failure (ADHF) in Indian patients. We herein report the in-hospital and 6-month outcome of Indian patients admitted with ADHF. Methods: We prospectively enrolled consecutive patients with ADHF due to systolic dysfunction in the acute failure registry and followed them up for at least 6 months. We analyzed the data on death and hospitalization of the first 90 patients on death and hospitalization over 6-months. Results: A total of 90 patients were enrolled with a mean age of 53.5 ± 17. 7 years and the majority were male (63%). The mean left ventricular ejection fraction was 29.2± 11.9%. The in hospital mortality was 30.8%. Postdischarge 6-month major adverse event (re-hospitalization/mortality combined) and mortality rates were 39.5% and 26.3%, respectively. Conclusions: These data from a single referral center provide insights into the current status of acute HF care in India. We report a higher in-hospital and follow-up mortality rates in ADHF patients who present at younger ages than reported in Western literature