Adenylyl Cyclases 1 and 8 Initiate a Presynaptic Homeostatic Response to Ethanol Treatment

BACKGROUND:Although ethanol exerts widespread action in the brain, only recently has progress been made in understanding the specific events occurring at the synapse during ethanol exposure. Mice deficient in the calcium-stimulated adenylyl cyclases, AC1 and AC8 (DKO), demonstrate increased sedation duration and impaired phosphorylation by protein kinase A (PKA) following acute ethanol treatment. While not direct targets for ethanol, we hypothesize that these cyclases initiate a homeostatic presynaptic response by PKA to reactivate neurons from ethanol-mediated inhibition. METHODOLOGY/PRINCIPAL FINDINGS:Here, we have used phosphoproteomic techniques and identified several presynaptic proteins that are phosphorylated in the brains of wild type mice (WT) after ethanol exposure, including synapsin, a known PKA target. Phosphorylation of synapsins I and II, as well as phosphorylation of non-PKA targets, such as, eukaryotic elongation factor-2 (eEF-2) and dynamin is significantly impaired in the brains of DKO mice. This deficit is primarily driven by AC1, as AC1-deficient, but not AC8-deficient mice also demonstrate significant reductions in phosphorylation of synapsin and eEF-2 in cortical and hippocampal tissues. DKO mice have a reduced pool of functional recycling vesicles and fewer active terminals as measured by FM1-43 uptake compared to WT controls, which may be a contributing factor to the impaired presynaptic response to ethanol treatment. CONCLUSIONS/SIGNIFICANCE:These data demonstrate that calcium-stimulated AC-dependent PKA activation in the presynaptic terminal, primarily driven by AC1, is a critical event in the reactivation of neurons following ethanol-induced activity blockade

Biological/Biomedical Accelerator Mass Spectrometry Targets. 1. Optimizing the CO2 Reduction Step Using Zinc Dust

Biological and biomedical applications of accelerator mass spectrometry (AMS) use isotope ratio mass spectrometry to quantify minute amounts of long-lived radioisotopes such as 14C. AMS target preparation involves first the oxidation of carbon (in sample of interest) to CO2 and second the reduction of CO2 to filamentous, fluffy, fuzzy, or firm graphite-like substances that coat a −400-mesh spherical iron powder (−400MSIP) catalyst. Until now, the quality of AMS targets has been variable; consequently, they often failed to produce robust ion currents that are required for reliable, accurate, precise, and high-throughput AMS for biological/biomedical applications. Therefore, we described our optimized method for reduction of CO2 to high-quality uniform AMS targets whose morphology we visualized using scanning electron microscope pictures. Key features of our optimized method were to reduce CO2 (from a sample of interest that provided 1 mg of C) using 100 ± 1.3 mg of Zn dust, 5 ± 0.4 mg of −400MSIP, and a reduction temperature of 500 °C for 3 h. The thermodynamics of our optimized method were more favorable for production of graphite-coated iron powders (GCIP) than those of previous methods. All AMS targets from our optimized method were of 100% GCIP, the graphitization yield exceeded 90%, and δ13C was −17.9 ± 0.3‰. The GCIP reliably produced strong 12C− currents and accurate and precise Fm values. The observed Fm value for oxalic acid II NIST SRM deviated from its accepted Fm value of 1.3407 by only 0.0003 ± 0.0027 (mean ± SE, n = 32), limit of detection of 14C was 0.04 amol, and limit of quantification was 0.07 amol, and a skilled analyst can prepare as many as 270 AMS targets per day. More information on the physical (hardness/color), morphological (SEMs), and structural (FT-IR, Raman, XRD spectra) characteristics of our AMS targets that determine accurate, precise, and high-hroughput AMS measurement are in the companion paper

Copper-Triggered Aggregation of Ubiquitin

Neurodegenerative disorders share common features comprising aggregation of misfolded proteins, failure of the ubiquitin-proteasome system, and increased levels of metal ions in the brain. Protein aggregates within affected cells often contain ubiquitin, however no report has focused on the aggregation propensity of this protein. Recently it was shown that copper, differently from zinc, nickel, aluminum, or cadmium, compromises ubiquitin stability and binds to the N-terminus with 0.1 micromolar affinity. This paper addresses the role of copper upon ubiquitin aggregation. In water, incubation with Cu(II) leads to formation of spherical particles that can progress from dimers to larger conglomerates. These spherical oligomers are SDS-resistant and are destroyed upon Cu(II) chelation or reduction to Cu(I). In water/trifluoroethanol (80∶20, v/v), a mimic of the local decrease in dielectric constant experienced in proximity to a membrane surface, ubiquitin incubation with Cu(II) causes time-dependent changes in circular dichroism and Fourier-transform infrared spectra, indicative of increasing β-sheet content. Analysis by atomic force and transmission electron microscopy reveals, in the given order, formation of spherical particles consistent with the size of early oligomers detected by gel electrophoresis, clustering of these particles in straight and curved chains, formation of ring structures, growth of trigonal branches from the rings, coalescence of the trigonal branched structures in a network. Notably, none of these ubiquitin aggregates was positive to tests for amyloid and Cu(II) chelation or reduction produced aggregate disassembly. The early formed Cu(II)-stabilized spherical oligomers, when reconstituted in 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) liposomes and in POPC planar bilayers, form annular and pore-like structures, respectively, which are common to several neurodegenerative disorders including Parkinson's, Alzheimer's, amyotrophic lateral sclerosis, and prion diseases, and have been proposed to be the primary toxic species. Susceptibility to aggregation of ubiquitin, as it emerges from the present study, may represent a potential risk factor for disease onset or progression while cells attempt to tag and process toxic substrates

LISA technology and instrumentation

This article reviews the present status of the technology and instrumentation for the joint ESA/NASA gravitational wave detector LISA. It briefly describes the measurement principle and the mission architecture including the resulting sensitivity before focussing on a description of the main payload items, such as the interferomtric measurement system, comprising the optical system with the optical bench and the telescope, the laser system, and the phase measurement system; and the disturbance reduction system with the inertial sensor, the charge control system, and the micropropulsion system. The article touches upon the requirements for the different subsystems that need to be fulfilled to obtain the overall sensitivity.Comment: 37 pages, 18 figures, submitted to CQ

Meta Modeling for Business Process Improvement

Conducting business process improvement (BPI) initiatives is a topic of high priority for today’s companies. However, performing BPI projects has become challenging. This is due to rapidly changing customer requirements and an increase of inter-organizational business processes, which need to be considered from an end-to-end perspective. In addition, traditional BPI approaches are more and more perceived as overly complex and too resource-consuming in practice. Against this background, the paper proposes a BPI roadmap, which is an approach for systematically performing BPI projects and serves practitioners’ needs for manageable BPI methods. Based on this BPI roadmap, a domain-specific conceptual modeling method (DSMM) has been developed. The DSMM supports the efficient documentation and communication of the results that emerge during the application of the roadmap. Thus, conceptual modeling acts as a means for purposefully codifying the outcomes of a BPI project. Furthermore, a corresponding software prototype has been implemented using a meta modeling platform to assess the technical feasibility of the approach. Finally, the usability of the prototype has been empirically evaluated

Neuer Kopf, alte Ideen? : "Normalisierung" des Front National unter Marine Le Pen

In this article, it is investigated whether vibrational entropy (VE) is an important contribution to the free energy of globular proteins at ambient conditions. VE represents the major configurational-entropy contribution of these proteins. By definition, it is an average of the configurational entropies of the protein within single minima of the energy landscape, weighted by their occupation probabilities. Its large part originates from thermal motion of flexible torsion angles giving rise to the finite peak widths observed in torsion angle distributions. While VE may affect the equilibrium properties of proteins, it is usually neglected in numerical calculations as its consideration is difficult. Moreover, it is sometimes believed that all well-packed conformations of a globular protein have similar VE anyway. Here, we measure explicitly the VE for six different conformations from simulation data of a test protein. Estimates are obtained using the quasi-harmonic approximation for three coordinate sets, Cartesian, bond-angle-torsion (BAT), and a new set termed rotamer-degeneracy lifted BAT coordinates by us. The new set gives improved estimates as it overcomes a known shortcoming of the quasi-harmonic approximation caused by multiply populated rotamer states, and it may serve for VE estimation of macromolecules in a very general context. The obtained VE values depend considerably on the type of coordinates used. However, for all coordinate sets we find large entropy differences between the conformations, of the order of the overall stability of the protein. This result may have important implications on the choice of free energy expressions used in software for protein structure prediction, protein design, and NMR refinement

The first measurement of the top quark mass at CDF II in the lepton+jets and dilepton channels simultaneously

submitted to Phys. Rev. DWe present a measurement of the mass of the top quark using data corresponding to an integrated luminosity of 1.9fb^-1 of ppbar collisions collected at sqrt{s}=1.96 TeV with the CDF II detector at Fermilab's Tevatron. This is the first measurement of the top quark mass using top-antitop pair candidate events in the lepton + jets and dilepton decay channels simultaneously. We reconstruct two observables in each channel and use a non-parametric kernel density estimation technique to derive two-dimensional probability density functions from simulated signal and background samples. The observables are the top quark mass and the invariant mass of two jets from the W decay in the lepton + jets channel, and the top quark mass and the scalar sum of transverse energy of the event in the dilepton channel. We perform a simultaneous fit for the top quark mass and the jet energy scale, which is constrained in situ by the hadronic W boson mass. Using 332 lepton + jets candidate events and 144 dilepton candidate events, we measure the top quark mass to be mtop=171.9 +/- 1.7 (stat. + JES) +/- 1.1 (syst.) GeV/c^2 = 171.9 +/- 2.0 GeV/c^2.We present a measurement of the mass of the top quark using data corresponding to an integrated luminosity of 1.9  fb-1 of pp̅ collisions collected at √s=1.96  TeV with the CDF II detector at Fermilab’s Tevatron. This is the first measurement of the top quark mass using top-antitop pair candidate events in the lepton+jets and dilepton decay channels simultaneously. We reconstruct two observables in each channel and use a nonparametric kernel density estimation technique to derive two-dimensional probability density functions from simulated signal and background samples. The observables are the top quark mass and the invariant mass of two jets from the W decay in the lepton+jets channel, and the top quark mass and the scalar sum of transverse energy of the event in the dilepton channel. We perform a simultaneous fit for the top quark mass and the jet energy scale, which is constrained in situ by the hadronic W boson mass. Using 332 lepton+jets candidate events and 144 dilepton candidate events, we measure the top quark mass to be Mtop=171.9±1.7(stat+JES)±1.1(other syst)  GeV/c2=171.9±2.0  GeV/c2.Peer reviewe