Non-Ergodic Behaviour of the k-Body Embedded Gaussian Random Ensembles for Bosons

We investigate the shape of the spectrum and the spectral fluctuations of the $k$-body Embedded Gaussian Ensemble for Bosons in the dense limit, where the number of Bosons $m \to \infty$ while both $k$, the rank of the interaction, and $l$, the number of single-particle states, are kept fixed. We show that the relative fluctuations of the low spectral moments do not vanish in this limit, proving that the ensemble is non-ergodic. Numerical simulations yield spectra which display a strong tendency towards picket-fence type. The wave functions also deviate from canonical random-matrix behaviourComment: 7 pages, 5 figures, uses epl.cls (included

Wigner--Dyson statistics for a class of integrable models

We construct an ensemble of second--quantized Hamiltonians with two bosonic degrees of freedom, whose members display with probability one GOE or GUE statistics. Nevertheless, these Hamiltonians have a second integral of motion, namely the boson number, and thus are integrable. To construct this ensemble we use some ``reverse engineering'' starting from the fact that $n$--bosons in a two--level system with random interactions have an integrable classical limit by the old Heisenberg association of boson operators to actions and angles. By choosing an $n$--body random interaction and degenerate levels we end up with GOE or GUE Hamiltonians. Ergodicity of these ensembles completes the example.Comment: 3 pages, 1 figur

Hyperfine Anomaly of Be Isotopes and Anomalous Large Anomaly in 11^{11}Be

A new result of investigations of the hyperfine structure (hfs) anomaly in Be isotopes is presented. The hfs constant for $^{11}$Be is obtained by using the core plus neutron type wave function: $|2s_{1\over 2}>+|1d_{5\over2}\times 2^+ ; {1/2}^{+}>$. A large hfs anomaly of $^{11}$Be is found, which is mainly due to a large radius of the halo single particle state.Comment: 14 pages, Late

Hyperfine Structure Constants for Eu Isotopes: Is The Empirical Formula of HFS Anomaly Universal ?

We calculate the hyperfine structure constant for the Eu isotopes with shell model wave functions. The calculated results are compared with those predicted by the Moskowitz-Lombardi (M-L) empirical formula. It turns out that the two approaches give the very different behaviors of the hfs constants in the isotope dependence. This should be easily measured by experiment, which may lead to the universality check of the M-L formula.Comment: 18 pages, Latex, two figure

Nucleon Edm from Atomic Systems and Constraints on Supersymmetry Parameters

The nucleon EDM is shown to be directly related to the EDM of atomic systems. From the observed EDM values of the atomic Hg system, the neutron EDM can be extracted, which gives a very stringent constraint on the supersymmetry parameters. It is also shown that the measurement of Nitrogen and Thallium atomic systems should provide important information on the flavor dependence of the quark EDM. We perform numerical analyses on the EDM of neutron, proton and electron in the minimal supersymmetric standard model with CP-violating phases. We demonstrate that the new limit on the neutron EDM extracted from atomic systems excludes a wide parameter region of supersymmetry breaking masses above 1 TeV, while the old limit excludes only a small mass region below 1 TeV.Comment: 10 pages, 7 figure file

Review of the k-Body Embedded Ensembles of Gaussian Random Matrices

The embedded ensembles were introduced by Mon and French as physically more plausible stochastic models of many--body systems governed by one--and two--body interactions than provided by standard random--matrix theory. We review several approaches aimed at determining the spectral density, the spectral fluctuation properties, and the ergodic properties of these ensembles: moments methods, numerical simulations, the replica trick, the eigenvector decomposition of the matrix of second moments and supersymmetry, the binary correlation approximation, and the study of correlations between matrix elements.Comment: Final version. 29 pages, 4 ps figures, uses iopart.st

Antibodies against cyclic citrullinated peptide don’t decrease after 6 months of infliximab treatment in refractory rheumatoid arthritis

Anti-citrullinated peptide antibodies (ACPA) and the rheumatoid factor (RF) are well-established serological markers for rheumatoid arthritis (RA). ACPA are very useful in the diagnosis of RA, especially at the early stages of the disease when ACPA have a greater diagnostic value than RF. The aim of the study was to assess the influence of infliximab treatment on RF IgM and ACPA serum levels and RA activity during 6 months of treatment. Thirty-two patients with refractory RA were treated with infliximab during a 6-month period. At baseline, 3 and 6 months of treatment the patients were examined for the number swollen and tender joints out of 28 (SJC, TJC) and the visual analogue scale of arthritis activity according to the patient (VAS). Serum samples were tested for erythrocyte sedimentation rate (ESR), C-reactive protein level (CRP), ACPA and RF IgM. The disease activity score (DAS-28) parameter was also calculated at the same time. During the course of our study, we observed statistically significant improvement in ESR, CRP, TJC, SJC, VAS DAS-28, and RF IgM after 3 and 6 months of infliximab treatment when compared to the baseline, whereas the ACPA level remained unchanged after 3 and 6 months of treatment (P = 0.96 and P = 0.85). The changes in the ACPA level are not a factor for evaluation of successful infliximab treatment but the changes in RF IgM are. According to different behavior of these antibodies during infliximab treatment, we suggest that the roles of ACPA and RF in the pathogenesis of RA are different

The relationship between the presence of anti-cyclic citrullinated peptide antibodies and clinical phenotype in very early rheumatoid arthritis

<p>Abstract</p> <p>Background</p> <p>Anti-cyclic citrullinated peptide (anti-CCP) antibodies are highly specific for RA, but are not detectable in all RA patients. The aim of this study was to establish whether the clinical phenotypes of anti-CCP positive and negative disease are distinct at the earliest clinically apparent phase of disease.</p> <p>Methods</p> <p>Patients were recruited from the Birmingham early inflammatory arthritis clinic. Participants were included in the current study if they presented within 3 months of symptom onset and fulfilled 1987 ACR criteria for RA at some point during an 18 month follow-up. Data were collected on demographic variables, joint symptoms and tender (n = 68) and swollen (n = 66) joint counts. CRP, ESR, rheumatoid factor and anti-CCP2 status were measured.</p> <p>Results</p> <p>92 patients were included (48 anti-CCP positive). The anti-CCP positive and negative groups were comparable in terms of demographic variables, inflammatory markers, joint counts and 1987 ACR classification criteria, except that more anti-CCP positive patients were rheumatoid factor positive (83.3% vs. 11.4%, p < 0.01). There was no significant difference in the pattern of joint involvement, except for an increased prevalence of knee joint swelling in anti-CCP positive patients (42.9% vs. 22.2%, p = 0.03).</p> <p>Conclusions</p> <p>Patients with and without anti-CCP antibodies present in a similar way, even within three months of clinically apparent disease that eventually develops into RA.</p

Serum MicroRNA-21 as Marker for Necroinflammation in Hepatitis C Patients with and without Hepatocellular Carcinoma

Background: MicroRNA-21 (miR-21) is up-regulated in tumor tissue of patients with malignant diseases, including hepatocellular carcinoma (HCC). Elevated concentrations of miR-21 have also been found in sera or plasma from patients with malignancies, rendering it an interesting candidate as serum/plasma marker for malignancies. Here we correlated serum miR-21 levels with clinical parameters in patients with different stages of chronic hepatitis C virus infection (CHC) and CHC-associated HCC. Methodology/Principal Findings: 62 CHC patients, 29 patients with CHC and HCC and 19 healthy controls were prospectively enrolled. RNA was extracted from the sera and miR-21 as well as miR-16 levels were analyzed by quantitative real-time PCR; miR-21 levels (normalized by miR-16) were correlated with standard liver parameters, histological grading and staging of CHC. The data show that serum levels of miR-21 were elevated in patients with CHC compared to healthy controls (P<0.001); there was no difference between serum miR-21 in patients with CHC and CHC-associated HCC. Serum miR-21 levels correlated with histological activity index (HAI) in the liver (r = −0.494, P = 0.00002), alanine aminotransferase (ALT) (r = −0.309, P = 0.007), aspartate aminotransferase (r = −0.495, P = 0.000007), bilirubin (r = −0.362, P = 0.002), international normalized ratio (r = −0.338, P = 0.034) and γ-glutamyltransferase (r = −0.244, P = 0.034). Multivariate analysis revealed that ALT and miR-21 serum levels were independently associated with HAI. At a cut-off dCT of 1.96, miR-21 discriminated between minimal and mild-severe necroinflammation (AUC = 0.758) with a sensitivity of 53.3% and a specificity of 95.2%. Conclusions/Significance: The serum miR-21 level is a marker for necroinflammatory activity, but does not differ between patients with HCV and HCV-induced HCC