2,434 research outputs found

    Ab-initio calculation of the 6Li{}^6Li binding energy with the Hybrid Multideterminant scheme

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    We perform an ab-initio calculation for the binding energy of 6Li{}^6Li using the CD-Bonn 2000 NN potential renormalized with the Lee-Suzuki method. The many-body approach to the problem is the Hybrid Multideterminant method. The results indicate a binding energy of about 31MeV31 MeV, within a few hundreds KeV uncertainty. The center of mass diagnostics are also discussed.Comment: 18 pages with 3 figures. More calculations added, to be published in EPJ

    Personalized reduced 3-lead system formation methodology for Remote Health Monitoring applications and reconstruction of standard 12-lead system

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    Remote Health Monitoring (RHM) applications encounter limitations from technological front viz. bandwidth, storage and transmission time and the medical science front i.e. usage of 2-3 lead systems instead of the standard 12-lead (S12) system. Technological limitations constraint the number of leads to 2-3 while cardiologists accustomed with 12-Lead ECG may find these 2-3 lead systems insufficient for diagnosis. Thus, the aforementioned limitations pose self-contradicting challenges for RHM. A personalized reduced 2/3 lead system is required which can offer equivalent information as contained in S12 system, so as to accurately reconstruct S12 system from reduced lead system for diagnosis. In this paper, we propose a personalized reduced 3-lead (R3L) system formation methodology which employs principal component analysis, thereby, reducing redundancy and increasing SNR ratio, hence, making it suitable for wireless transmission. Accurate S12 system is made available using personalized lead reconstruction methodology, thus addressing medical constraints. Mean R2 statistics values obtained for reconstruction of S12 system from the proposed R3L system using PhysioNet's PTB and TWA databases were 95.63% and 96.37% respectively. To substantiate the superior diagnostic quality of reconstructed leads, root mean square error (RMSE) metrics obtained upon comparing the ECG features extracted from the original and reconstructed leads, using our recently proposed Time Domain Morphology and Gradient (TDMG) algorithm, have been analyzed and discussed. The proposed system does not require any extra electrode or modification in placement positions and hence, can readily find application in computerized ECG machines

    Coronary flow reserve of the angiographically normal left anterior descending coronary artery in patients with remote coronary artery disease

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    Coronary artery disease (CAD) has been suggested to alter coronary flow reserve (CFR; the ratio between hyperemic and baseline coronary flow velocities) not only in territories supplied by stenotic arteries but also in angiographically normal, remote regions. However, few data exist regarding the left anterior descending (LAD) coronary artery as the normal index artery. The influence of remote CAD on CFR of the angiographically normal LAD was evaluated with transthoracic Doppler ultrasound to measure CFR in the LAD during 90 seconds of venous adenosine infusion (140 microg/kg/min) in 122 subjects who were assigned to 1 group; group 1 comprised 49 controls without angiographically detectable CAD, and group 2 consisted of 73 patients with an angiographically normal LAD and remote CAD. Group 2 was divided into 4 subgroups: 16 patients with previous remote percutaneous coronary intervention (group 2A); 13 patients with significant remote stenosis (group 2B); 23 patients with previous remote myocardial infarction and percutaneous coronary intervention (group 2C); and 21 patients with previous remote myocardial infarction but no percutaneous coronary intervention (group 2D). CFR in the LAD was not significantly different in groups 1 and 2 (3.08 +/- 0.61 and 3.03 +/- 0.69, respectively, p = NS). Decreased ejection fraction and increased wall motion score index in patients with remote CAD (p < 0.00001) and multivessel CAD did not affect CFR in the LAD (group 2A 3.18 +/- 0.77; group 2B 3.05 +/- 0.65; group 2C 3.07 +/- 0.79; group 2D 2.86 +/- 0.50, respectively; F = 0.63, p = NS). In conclusion, CFR of an angiographically normal LAD is preserved in patients with remote CAD, even in the presence of previous remote myocardial infarction and wall motion abnormalities

    Association of patient-reported outcomes and heart rate trends in heart failure. a report from the chiron project

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    Patient-reported outcomes (PROs) have been previously considered “soft” end-points because of the lack of association of the reported outcome to measurable biological parameters. The present study aimed to assess whether electrocardiographic measures are associated to PROs changes. We evaluated the association between heart rate (HR), QRS and QT/QTc durations and PROs, classified as “good” or “bad” according to the patients’ overall feeling of health, in patients from the Chiron project. Twenty-four chronic heart failure (HF) patients were enrolled in the study (71% male, mean age 62.9 ± 9.4 years, 42% ischemic etiology, 15 NYHA class II and 9 class III) providing 1086 days of usable physiological recordings (4 hours/day). The mean HR was significantly higher in the “bad” than in the “good” PROs class (74.0 ± 6.4 bpm vs 68.0 ± 7.2 bpm; p &lt; 0.001). Conversely, the ratio between movement and rest activities showed significantly higher values in “good” compared to “bad” PROs. We also found significantly longer QTc and QRS durations in patients with “bad” PROs compared to patients with “good” PROs. That in patients with mild to moderate HF, higher HR, wider QRS and longer QTc, as well as a reduced HR ratio between movement and rest, were associated with “bad” PROs is clinically noteworthy because the association of worse PROs with measurable variations of biological parameters may help physicians in evaluating PROs reliability itself and in their clinical decisions. Whether a timely intervention on these biological parameters may prevent adverse outcomes is important and deserves to be investigated in further studies

    Experimental and numerical research activity on a packed bed TES system

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    This paper presents the results of experimental and numerical research activities on a packed bed sensible thermal energy storage (TES) system. The TES consists of a cylindrical steel tank filled with small alumina beads and crossed by air used as the heat transfer fluid. Experimental tests were carried out hile varying some operating parameters such as the mass flow rate, the inlet–outlet temperature thresholds and the aspect ratio (length over diameter). Numerical simulations were carried out using a one-dimensional model, specifically developed in the Matlab-Simulink environment and a 2D axisymmetric model based on the ANSYS-Fluent platform. Both models are based on a two-equation transient approach to calculate fluid and solid phase temperatures. Thermodynamic properties were considered to be temperature-dependent and, in the Computational Fluid Dynamics (CFD) model, variable porosity of the bed in the radial direction, thermal losses and the effective conductivity of the alumina beads were also considered. The simulation results of both models were compared to the experimental ones, showing good agreement. The one-dimensional model has the advantage of predicting the axial temperature distribution with a very low computational cost, but it does not allow calculation of the correct energy stored when the temperature distribution is strongly influenced by the wall. To overcome this problem a 2D CFD model was used in this work

    Study of dimuon production in Indium-Indium collisions with the NA60 experiment

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    The NA60 experiment at the CERN-SPS is devoted to the study of dimuon production in heavy-ion and proton-nucleus collisions. We present preliminary results from the analysis of Indium-Indium collisions at 158 GeV per nucleon. The topics covered are low mass vector meson production, J/psi production and suppression, and the feasibility of the open charm measurement from the dimuon continuum in the mass range below the J/psi peak.Comment: Contribution at XXXXth Rencontres de Moriond, "QCD and High Energy Hadronic Interactions

    The Long Journey from Ab Initio Calculations to Density Functional Theory for Nuclear Large Amplitude Collective Motion

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    At present there are two vastly different ab initio approaches to the description of the the many-body dynamics: the Density Functional Theory (DFT) and the functional integral (path integral) approaches. On one hand, if implemented exactly, the DFT approach can allow in principle the exact evaluation of arbitrary one-body observable. However, when applied to Large Amplitude Collective Motion (LACM) this approach needs to be extended in order to accommodate the phenomenon of surface-hoping, when adiabaticity is strongly violated and the description of a system using a single (generalized) Slater determinant is not valid anymore. The functional integral approach on the other hand does not appear to have such restrictions, but its implementation does not appear to be straightforward endeavor. However, within a functional integral approach one seems to be able to evaluate in principle any kind of observables, such as the fragment mass and energy distributions in nuclear fission. These two radically approaches can likely be brought brought together by formulating a stochastic time-dependent DFT approach to many-body dynamics.Comment: 9 page

    Evidence for radial flow of thermal dileptons in high-energy nuclear collisions

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    The NA60 experiment at the CERN SPS has studied low-mass dimuon production in 158 AGeV In-In collisions. An excess of pairs above the known meson decays has been reported before. We now present precision results on the associated transverse momentum spectra. The slope parameter Teff extracted from the spectra rises with dimuon mass up to the rho, followed by a sudden decline above. While the initial rise is consistent with the expectations for radial flow of a hadronic decay source, the decline signals a transition to an emission source with much smaller flow. This may well represent the first direct evidence for thermal radiation of partonic origin in nuclear collisions.Comment: Accepted for publication in Physical Review Letter

    Latest results from NA60

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    The NA60 experiment has measured the production of muon pairs and of charged particles in In+In collisions at a beam energy of 158 AGeV. For invariant dimuon masses below the phi the space-time averaged rho spectral function was isolated by a novel procedure. It shows a strong broadening but essentially no shift in mass. The production of J/psi was measured as a function of the collision centrality. As in previous experiments studying Pb+Pb collisions an anomalous supression is observed, setting in at approximately 90 participant nucleons. Using the charged particles the reaction plane was reconstructed. The elliptic flow of charged particles increases with pt showing a saturation for pt > 2GeV/c. For the first time azimuthal distributions for J/psi are shown.Comment: 9 pages, 11 figures, talk given at the conference "Strangeness in Quark Matter 2006 (SQM2006)", March 2006, Los Angeles, USA, accepted for publication in Journal of Physics

    ϕ\phi Meson Production in In-In Collisions and the ϕ\phi Puzzle

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    The NA60 experiment measured dimuon production in In-In collisions at 158 AGeV. This paper presents a high statistics measurement of ϕμμ\phi\to\mu\mu with the specific objective to provide insight on the ϕ\phi puzzle, i.e. the difference in the inverse TT slopes and absolute yields measured by NA49 and NA50 in the kaon and lepton channel, respectively. Transverse momentum distributions were studied as a function of centrality. The slope parameter TT shows a rapid increase with centrality, followed by a saturation. Variations of TT with the fit range of the order of 15 MeV were observed, possibly as a consequence of radial flow. The ϕ\phi meson yield normalized to the number of participants increases with centrality and is consistently higher than the yield measured by the NA49 experiment at any centrality.Comment: 4 Pages, 2 Figures. Proceedings of the 20th^{th} International Conference on Ultra-Relativistic Nucleus Nucleus Collision
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