The number of metastable states in the generalized random orthogonal model

We calculate the number of metastable states in the generalized random orthogonal model. The results obtained are verified by exact numerical enumeration for small systems sizes but taking into account finite size effects. These results are compared with those for Hopfield model in order to examine the effect of strict orthonormality of neural network patterns on the number of metastable states.Comment: 12 pages, 4 EPS figure

Search for Pair Production of Scalar Top Quarks Decaying to a tau Lepton and a b Quark in ppbar Collisions at sqrt{s}=1.96 TeV

We search for pair production of supersymmetric top quarks (~t_1), followed by R-parity violating decay ~t_1 -> tau b with a branching ratio beta, using 322 pb^-1 of ppbar collisions at sqrt{s}=1.96 TeV collected by the CDF II detector at Fermilab. Two candidate events pass our final selection criteria, consistent with the standard model expectation. We set upper limits on the cross section sigma(~t_1 ~tbar_1)*beta^2 as a function of the stop mass m(~t_1). Assuming beta=1, we set a 95% confidence level limit m(~t_1)>153 GeV/c^2. The limits are also applicable to the case of a third generation scalar leptoquark (LQ_3) decaying LQ_3 -> tau b.Comment: 7 pages, 2 eps figure

Higher harmonic anisotropic flow measurements of charged particles in Pb-Pb collisions at 2.76 TeV

We report on the first measurement of the triangular $v_3$, quadrangular $v_4$, and pentagonal $v_5$ charged particle flow in Pb-Pb collisions at 2.76 TeV measured with the ALICE detector at the CERN Large Hadron Collider. We show that the triangular flow can be described in terms of the initial spatial anisotropy and its fluctuations, which provides strong constraints on its origin. In the most central events, where the elliptic flow $v_2$ and $v_3$ have similar magnitude, a double peaked structure in the two-particle azimuthal correlations is observed, which is often interpreted as a Mach cone response to fast partons. We show that this structure can be naturally explained from the measured anisotropic flow Fourier coefficients.Comment: 10 pages, 4 figures, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/387

Impact of clinical phenotypes on management and outcomes in European atrial fibrillation patients: a report from the ESC-EHRA EURObservational Research Programme in AF (EORP-AF) General Long-Term Registry

Background: Epidemiological studies in atrial fibrillation (AF) illustrate that clinical complexity increase the risk of major adverse outcomes. We aimed to describe European AF patients\u2019 clinical phenotypes and analyse the differential clinical course. Methods: We performed a hierarchical cluster analysis based on Ward\u2019s Method and Squared Euclidean Distance using 22 clinical binary variables, identifying the optimal number of clusters. We investigated differences in clinical management, use of healthcare resources and outcomes in a cohort of European AF patients from a Europe-wide observational registry. Results: A total of 9363 were available for this analysis. We identified three clusters: Cluster 1 (n = 3634; 38.8%) characterized by older patients and prevalent non-cardiac comorbidities; Cluster 2 (n = 2774; 29.6%) characterized by younger patients with low prevalence of comorbidities; Cluster 3 (n = 2955;31.6%) characterized by patients\u2019 prevalent cardiovascular risk factors/comorbidities. Over a mean follow-up of 22.5 months, Cluster 3 had the highest rate of cardiovascular events, all-cause death, and the composite outcome (combining the previous two) compared to Cluster 1 and Cluster 2 (all P <.001). An adjusted Cox regression showed that compared to Cluster 2, Cluster 3 (hazard ratio (HR) 2.87, 95% confidence interval (CI) 2.27\u20133.62; HR 3.42, 95%CI 2.72\u20134.31; HR 2.79, 95%CI 2.32\u20133.35), and Cluster 1 (HR 1.88, 95%CI 1.48\u20132.38; HR 2.50, 95%CI 1.98\u20133.15; HR 2.09, 95%CI 1.74\u20132.51) reported a higher risk for the three outcomes respectively. Conclusions: In European AF patients, three main clusters were identified, differentiated by differential presence of comorbidities. Both non-cardiac and cardiac comorbidities clusters were found to be associated with an increased risk of major adverse outcomes

The effects of γ-irradiation on the hydration characteristics of DNA and polynucleotides. III. A comparative NMR study of frozen and liquid solutions

The effects of γ-irradiation and changes in the macromolecular structure on the water proton resonance spectra observed in frozen and liquid solutions have been compared for the DNA and polynucleotide solutions, using H2O or mixed H2O/D2O solvents. The results indicate that in order to obtain information concerning the role of hydration water in mediating the overall radiation damage, the NMR studies must be performed in the frozen state.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

An NMR study of the relative interaction abilities of different pyrimidine nucleosides with serotonin

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

The effects of γ irradiation on the hydration characteristics of DNA and polynucleotides. II. An NMR study of mixed H2O/D2O frozen solutions

We have studied the effects of γ irradiation at different temperatures on the hydration water proton resonance spectra from frozen H2O/D2O solutions of DNA and polynucleotides. Comparison of results obtained with pure H2O solutions showed a striking difference in the temperature-dependent variations of Δ(1/2) values in nonirradiated and irradiated DNA solutions. There is evidence that base rehydration with hydration water molecules occurs after an initial damage to the macromolecular chains in DNA caused by the direct or indirect radiation effects.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

The effects of γ irradiation on the hydration characteristics of DNA and polynucleotides. I. An NMR study of frozen H2O and D2O solutions

Water proton and deuteron resonance spectra have been studied in frozen solutions of DNA, poly(A), poly(C), poly(U), poly(A+U) and poly (A+2U) at different temperatures between -5 and -40°C. Hydration water molecules exhibit high proton and molecular mobility in frozen solutions and are responsible for the observed spectra. The γ irradiation of solutions at O and -80°C results in striking changes in the proton spectra and no change in the deuteron spectra. These results suggest that proton exchange is an important factor in affecting the proton linewidth and the proton relaxation mechanism. The changes in molecular structure (either by γ irradiation or molecular association) influence the hydration water in a characteristic manner. The effects of irradiation at different temperatures (O, -80, and -196°C) suggest that hydration water makes a distinct contribution to the overall radical attack on the DNA molecule from the water medium.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Quality assessment in in vivo NMR spectroscopy. VI. Multicentre quantification of MRS test signals.

A numerical procedure is presented for mapping the vicinity of the null-space of the spin relaxation superoperator. The states populating this space, i.e. those with near-zero eigenvalues, of which the two-spin singlet is a well-studied example, are long-lived compared to the conventional T(1) and T(2) spin-relaxation times. The analysis of larger spin systems described herein reveals the presence of a significant number of other slowly relaxing states. A study of coupling topologies for n-spin systems (4≤n≤8) suggests the symmetry requirements for maximising the number of long-lived states