1,259 research outputs found
A Primer on Software Defined Radios
The commercial success of cellular phone systems during the late 1980s and early 1990 years heralded the wireless revolution that became apparent at the turn of the 21st century and has led the modern society to a highly interconnected world where ubiquitous connectivity and mobility are enabled by powerful wireless terminals. Software defined radio (SDR) technology has played a major role in accelerating the pace at which wireless capabilities have advanced, in particular over the past 15 years, and SDRs are now at the core of modern wireless communication systems. In this paper we give an overview of SDRs that includes a discussion of drivers and technologies that have contributed to their continuous advancement, and presents the theory needed to understand the architecture and operation of current SDRs. We also review the choices for SDR platforms and the programming options that are currently available for SDR research, development, and teaching, and present case studies illustrating SDR use. Our hope is that the paper will be useful as a reference to wireless researchers and developers working in the industry or in academic settings on further advancing and refining the capabilities of wireless systems
HDAC4 in cancer: A multitasking platform to drive not only epigenetic modifications
Controlling access to genomic information and maintaining its stability are key aspects of cell life. Histone acetylation is a reversible epigenetic modification that allows access to DNA and the assembly of protein complexes that regulate mainly transcription but also other activities. Enzymes known as histone deacetylases (HDACs) are involved in the removal of the acetyl-group or in some cases of small hydrophobic moieties from histones but also from the non-histone substrate. The main achievement of HDACs on histones is to repress transcription and promote the formation of more compact chromatin. There are 18 different HDACs encoded in the human genome. Here we will discuss HDAC4, a member of the class IIa family, and its possible contribution to cancer development
Solving shallow-water systems in 2D domains using Finite Volume methods and multimedia SSE instructions
AbstractThe goal of this paper is to construct efficient parallel solvers for 2D hyperbolic systems of conservation laws with source terms and nonconservative products. The method of lines is applied: at every intercell a projected Riemann problem along the normal direction is considered which is discretized by means of well-balanced Roe methods. The resulting 2D numerical scheme is explicit and first-order accurate. In [M.J. Castro, J.A. GarcĂa, J.M. González, C. Pares, A parallel 2D Finite Volume scheme for solving systems of balance laws with nonconservative products: Application to shallow flows, Comput. Methods Appl. Mech. Engrg. 196 (2006) 2788–2815] a domain decomposition method was used to parallelize the resulting numerical scheme, which was implemented in a PC cluster by means of MPI techniques.In this paper, in order to optimize the computations, a new parallelization of SIMD type is performed at each MPI thread, by means of SSE (“Streaming SIMD Extensions”), which are present in common processors. More specifically, as the most costly part of the calculations performed at each processor consists of a huge number of small matrix and vector computations, we use the Intel© Integrated Performance Primitives small matrix library. To make easy the use of this library, which is implemented using assembler and SSE instructions, we have developed a C++ wrapper of this library in an efficient way. Some numerical tests were carried out to validate the performance of the C++ small matrix wrapper. The specific application of the scheme to one-layer Shallow-Water systems has been implemented on a PC’s cluster. The correct behavior of the one-layer model is assessed using laboratory data
Influência de luz na infecção da ferrugem da videira (Phakopsora euvitis).
O objetivo deste trabalho foi avaliar o efeito luz na infecção de P. euvitis.Suplemento, ref. 097, Edição dos Resumos do XXX Congresso Paulista de Fitopatologia, Botucatu, fev. 2007
Lombards on the move – An integrative study of the Migration Period cemetery of Szólád, Hungary
Control and kinetic analysis of ischemia-damaged heart mitochondria: which parts of the oxidative phosphorylation system are affected by ischemia?
AbstractWe investigated the effects of ischemia on the kinetics and control of mitochondria isolated from normal and ischemic heart. The dependence of the respiratory chain, phosphorylation system and proton leak on the mitochondrial membrane potential were measured in mitochondria from hearts after 0, 30 min and 45 min of in vitro ischemia. Data showed that during the development of ischemia from the reversible (30 min) to the irreversible (45 min) phase, a progressive decrease in activity of the respiratory chain occurs. At the same time an increase in proton leak across the mitochondrial inner membrane was observed. Phosphorylation is inhibited but seems to be less affected by ischemia than respiratory chain or proton leak. Control coefficients of the 3 blocks of reactions over respiration rate were determined in different respiratory states between state 4 and state 3. Ischemia caused the control exerted by the proton leak to increase in state 3 and the intermediate state and caused the control by the phosphorylation system to decrease in the intermediate state. Taken together, these results indicate that the main effects of ischemia on mitochondrial respiration are an inhibition of the respiratory chain and an increase of the proton leak
A consensus framework map of durum wheat (Triticum durum Desf.) suitable for linkage disequilibrium analysis and genome-wide association mapping
As doenças da pupunheira (Bactris gasipaes Kunth): antracnose e podridao da medula.
bitstream/CNPF-2009-09/30405/1/com_tec63.pd
A Primer on Software Defined Radios
The commercial success of cellular phone systems during the late 1980s and early 1990 years heralded the wireless revolution that became apparent at the turn of the 21st century and has led the modern society to a highly interconnected world where ubiquitous connectivity and mobility are enabled by powerful wireless terminals. Software defined radio (SDR) technology has played a major role in accelerating the pace at which wireless capabilities have advanced, in particular over the past 15 years, and SDRs are now at the core of modern wireless communication systems. In this paper we give an overview of SDRs that includes a discussion of drivers and technologies that have contributed to their continuous advancement, and presents the theory needed to understand the architecture and operation of current SDRs. We also review the choices for SDR platforms and the programming options that are currently available for SDR research, development, and teaching, and present case studies illustrating SDR use. Our hope is that the paper will be useful as a reference to wireless researchers and developers working in the industry or in academic settings on further advancing and refining the capabilities of wireless systems
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