Optimal Strategies for Sinusoidal Signal Detection

We derive and study optimal and nearly-optimal strategies for the detection of sinusoidal signals hidden in additive (Gaussian and non-Gaussian) noise. Such strategies are an essential part of algorithms for the detection of the gravitational Continuous Wave (CW) signals produced by pulsars. Optimal strategies are derived for the case where the signal phase is not known and the product of the signal frequency and the observation time is non-integral.Comment: 18 pages, REVTEX4, 7 figures, 2 table

Respiratory chain complex I, a main regulatory target of the cAMP/PKA pathway is defective in different human diseases.

In mammals, complex I (NADH-ubiquinone oxidoreductase) of the mitochondrial respiratory chain has 31 supernumerary subunits in addition to the 14 conserved from prokaryotes to humans. Multiplicity of structural protein components, as well as of biogenesis factors, makes complex I a sensible pace-maker of mitochondrial respiration. The work reviewed here shows that the cAMP/PKA pathway regulates the biogenesis, assembly and catalytic activity of complex I and mitochondrial oxygen superoxide production. The structural, functional and regulatory complexity of complex I, renders it particularly vulnerable to genetic and sporadic pathological factors. Complex I dysfunction has, indeed, been found, to be associated with several human diseases. Knowledge of the pathogenetic mechanisms of these diseases can help to develop new therapeutic strategies. (C) 2011 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved

Immunomediated and ischemia-independent inflammation of coronary microvessels in unstable angina.

This study investigated whether the myocardium is involved in the acute inflammatory reaction associated with bursts of unstable angina (UA). We looked for the presence of activated DR+ inflammatory cells and the expression patterns, localization, and immunostaining identification of genes for cytokines (IL-1beta, TNF-alpha, IL-6, and IFN-gamma), MCP-1, and iNOS in the left ventricle biopsies from 2-vessel disease anginal patients, 24 with UA and 12 with stable angina (SA), who underwent coronary bypass surgery. Biopsy specimens from 6 patients with mitral stenosis who underwent valve replacement were examined as control hearts (CHs). Plasma levels of IL-2 soluble receptor (sIL-2R) were measured as a marker of systemic immune reaction. In CHs, DR+ cells were undetectable, and cytokine and iNOS mRNA expression were negligible. UA patients had higher sIL-2R levels than SA patients (P<0.01), and their biopsy specimens showed both numerous DR+ cells identified as lymphocytes, macrophages, endothelial cells, and elevated expression levels of cytokine and iNOS genes (from 2.4- to 6.1-fold vs SA; P<0.01). Cytokine and iNOS genes and proteins were localized in endothelial cells without involvement of myocytes. IL-1beta and MCP-1 mRNAs were nearly undetectable. No significant differences were found in the number of DR+ cells, levels of cytokine, and iNOS genes between potentially ischemic and nonischemic left ventricle areas. In SA specimens, DR+ cells were very rare and only mRNAs for TNF-alpha and iNOS genes were overexpressed versus CHs. These results indicated that an acute immunomediated inflammatory reaction, essentially involving coronary microvessels, is demonstrable in UA patients

Modeling Watershed Response in Semiarid Regions With High-Resolution Synthetic Aperture Radars

In this paper, we propose a methodology devoted to exploit the outstanding characteristics of COSMO-SkyMed for monitoring water bodies in semiarid countries at a scale never experienced before. The proposed approach, based on appropriate registration, calibration, and processing of synthetic aperture radar (SAR) data, allows outperforming the previously available methods for monitoring small reservoirs, mainly carried out with optical data, and severely limited by the presence of cloud coverage, which is a frequent condition in wet season. A tool has been developed for computing the water volumes retained in small reservoirs based on SAR-derived digital elevation model. These data have been used to derive a relationship between storage volumes and surface areas that can be used when bathymetric information is unavailable. Due to the lack of direct measures of river's discharge, the time evolution of water volumes retained at reservoirs has been used to validate a simple rainfall-runoff hydrological model that can provide useful recommendation for the management of small reservoirs. Operational scenarios concerning the improvement in the efficiency of reservoirs management and the estimation of their impact on downstream area point out the applicative outcomes of the proposed method

Insights into the Structural Basis of the GADD45β-mediated Inactivation of the JNK Kinase, MKK7/JNKK2

NF-kappaB/Rel factors control programmed cell death (PCD), and this control is crucial to oncogenesis, cancer chemoresistance, and antagonism of tumor necrosis factor (TNF) alpha-induced killing. With TNFalpha, NF-kappaB-mediated protection involves suppression of the c-Jun-N-terminal kinase (JNK) cascade, and we have identified Gadd45beta, a member of the Gadd45 family, as a pivotal effector of this activity of NF-kappaB. Inhibition of TNFalpha-induced JNK signaling by Gadd45beta depends on direct targeting of the JNK kinase, MKK7/JNKK2. The mechanism by which Gadd45beta blunts MKK7, however, is unknown. Here we show that Gadd45beta is a structured protein with a predicted four-stranded beta-sheet core, five alpha-helices, and two acidic loops. Association of Gadd45beta with MKK7 involves a network of interactions mediated by its putative helices alpha3 and alpha4 and loops 1 and 2. Whereas alpha3 appears to primarily mediate docking to MKK7, loop 1 and alpha4-loop 2 seemingly afford kinase inactivation by engaging the ATP-binding site and causing conformational changes that impede catalytic function. These data provide a basis for Gadd45beta-mediated blockade of MKK7, and ultimately, TNFalpha-induced PCD. They also have important implications for treatment of widespread diseases

Is the squeezing of relic gravitational waves produced by inflation detectable?

Grishchuk has shown that the stochastic background of gravitational waves produced by an inflationary phase in the early Universe has an unusual property: it is not a stationary Gaussian random process. Due to squeezing, the phases of the different waves are correlated in a deterministic way, arising from the process of parametric amplification that created them. The resulting random process is Gaussian but non-stationary. This provides a unique signature that could in principle distinguish a background created by inflation from stationary stochastic backgrounds created by other types of processes. We address the question: could this signature be observed with a gravitational wave detector? Sadly, the answer appears to be "no": an experiment which could distinguish the non-stationary behavior would have to last approximately the age of the Universe at the time of measurement. This rules out direct detection by ground and space based gravitational wave detectors, but not indirect detections via the electromagnetic Cosmic Microwave Background Radiation (CMBR).Comment: 17 pages, 4 Postscript figures, uses revtex, psfig, to be submitted to PRD, minor revisions - appendix B clarified, corrected typos, added reference

Stopping power of helium gas for ^9Be ions from 2 to 31 MeV

Abstract The stopping power of helium gas for 9Be ions from 2 to 31 MeV is experimentally determined using an indirect method. The residual energy of the 9Be beam as a function of the gas thickness is measured and the stopping power determined by differentiating the thickness–energy curve. The results are compared with predictions of the semi-empirical codes SRIM-2003 and MSTAR. Our data are in better agreement with the MSTAR calculations. The elastic scattering excitation function for the system 9Be + α, extracted using the thick target technique and our stopping power data, is in excellent agreement with the ones measured directly confirming the quality of our data