A New Parameter Set for the Relativistic Mean Field Theory

Subtracting the Strutinsky shell corrections from the selfconsistent energies obtained within the Relativistic Mean Field Theory (RMFT) we have got estimates for the macroscopic part of the binding energies of 142 spherical even-even nuclei. By minimizing their root mean square deviations from the values obtained with the Lublin-Srasbourg Drop (LSD) model with respect to the nine RMFT parameters we have found the optimal set (NL4). The new parameters reproduce also the radii of these nuclei with an accuracy comparable with that obtained with the NL1 and NL3 sets.Comment: Semiar given at the 10th Nuclear Physics Workshop in Kazimierz, Poland, Sep. 24-28, 200

The Network Analysis of Urban Streets: A Primal Approach

The network metaphor in the analysis of urban and territorial cases has a long tradition especially in transportation/land-use planning and economic geography. More recently, urban design has brought its contribution by means of the "space syntax" methodology. All these approaches, though under different terms like accessibility, proximity, integration,connectivity, cost or effort, focus on the idea that some places (or streets) are more important than others because they are more central. The study of centrality in complex systems,however, originated in other scientific areas, namely in structural sociology, well before its use in urban studies; moreover, as a structural property of the system, centrality has never been extensively investigated metrically in geographic networks as it has been topologically in a wide range of other relational networks like social, biological or technological. After two previous works on some structural properties of the dual and primal graph representations of urban street networks (Porta et al. cond-mat/0411241; Crucitti et al. physics/0504163), in this paper we provide an in-depth investigation of centrality in the primal approach as compared to the dual one, with a special focus on potentials for urban design.Comment: 19 page, 4 figures. Paper related to the paper "The Network Analysis of Urban Streets: A Dual Approach" cond-mat/041124

Random planar graphs and the London street network

In this paper we analyse the street network of London both in its primary and dual representation. To understand its properties, we consider three idealised models based on a grid, a static random planar graph and a growing random planar graph. Comparing the models and the street network, we find that the streets of London form a self-organising system whose growth is characterised by a strict interaction between the metrical and informational space. In particular, a principle of least effort appears to create a balance between the physical and the mental effort required to navigate the city

Description of Drip-Line Nuclei within Relativistic Mean-Field Plus BCS Approach

Recently it has been demonstrated, considering Ni and Ca isotopes as prototypes, that the relativistic mean-field plus BCS (RMF+BCS) approach wherein the single particle continuum corresponding to the RMF is replaced by a set of discrete positive energy states for the calculation of pairing energy provides a good approximation to the full relativistic Hartree-Bogoliubov (RHB) description of the ground state properties of the drip-line neutron rich nuclei. The applicability of RMF+BCS is essentially due to the fact that the main contribution to the pairing correlations is provided by the low-lying resonant states. General validity of this approach is demonstrated by the detailed calculations for the ground state properties of the chains of isotopes of O, Ca, Ni, Zr, Sn and Pb nuclei. The TMA and NL-SH force parameter sets have been used for the effective mean-field Lagrangian. Comprehensive results for the two neutron separation energy, rms radii, single particle pairing gaps and pairing energies etc. are presented. The Ca isotopes are found to exhibit distinct features near the neutron drip line whereby it is found that further addition of neutrons causes a rapid increase in the neutron rms radius with almost no increase in the binding energy, indicating the occurrence of halos. A comparison of these results with the available experimental data and with the recent continuum relativistic Hartree-Bogoliubov (RCHB) calculations amply demonstrates the validity and usefulness of this fast RMF+BCS approach.Comment: 59 pages, 40 figure

Room temperature midinfrared electroluminescence from GaInAsSbP light emitting diodes. .

Room temperature electroluminescence in the midinfrared near 4 µm is reported from GaInAsSbP light emitting diodes grown on GaSb by liquid phase epitaxy. Comparison of the electro- and photoluminescence revealed that light is generated on the p side of the diode. The energy shift (24 meV) is consistent with band gap narrowing and recombination via band tail states due to the Zn doping (1×1018 cm−3) in the p layer of the structure. The temperature dependent behavior of the luminescence and the improved emission intensity was attributed to recombination from localized states arising from electrostatic potential fluctuations due to compositional inhomogeneities in these alloys

Risk Factors for Hospital Admission After a Fall: A Prospective Cohort Study of Community-Dwelling Older People

Background: Falls in later life that require admission to hospital have well-established consequences for future disability and health. The likelihood and severity of a fall will result from the presence of one or more risk factors. The aim of this study is to examine risk factors identified for their ability to prevent falls and to assess whether they are associated with hospital admission after a fall. / Methods: Analyses of data from the English Longitudinal Study of Aging (ELSA), a prospective cohort study. In a sample of 3783 men and women older than 60 years old, a range of potential risk factors measured at Wave 4 (demographic, social environment, physical, and mental functioning) were examined as predictors of fall-related hospitalizations, identified using International Classification of Diseases, 10th Revision (ICD-10) code from linked hospital records in the United Kingdom. Subdistribution hazard models were used to account for competing risk of death. / Results: Several risk factors identified by previous work were confirmed. Suffering from urinary incontinence (subdistribution hazard ratio = 1.49; 95% CI: 1.14, 1.95) and osteoporosis (subdistribution hazard ratio = 1.48; 95% CI: 1.05, 2.07), which are not commonly considered at an early stage of screening, were found to be associated with hospital admission after a fall. Both low and moderate levels of physical activity were also found to somewhat increase the risk of hospital admission after a fall. / Conclusions: Several predictors of having a fall, severe enough to require hospital admission, have been confirmed. In particular, urinary incontinence should be considered at an earlier point in the assessment of risk

Suicide and depression in former contact sports participants: population-based cohort study, systematic review, and meta-analysis

Background: Former participants in sports characterised by low intensity repetitive head impact appear to have elevated rates of later dementia, but links with other psychological health outcomes such as depression and suicide are uncertain. We quantified the occurrence of these endpoints in former contact sports athletes against general population controls using new data from a cohort study and a meta-analysis. Methods: The cohort study comprised 2004 retired male athletes, who had competed internationally as amateurs for Finland across a range of sports, and 1385 general population controls. All study members were linked to mortality and hospitalisation registries. In the PROSPERO-registered systematic review (CRD42022352780), we searched PubMed and Embase to October 31 2022 for cohort studies that reported standard estimates of association and precision. Study-specific estimates were aggregated in a random-effect meta-analysis. The Newcastle-Ottawa Scale was used to appraise the quality of each study. Findings: In survival analyses of the Finnish cohort data, former boxers (depression: hazard ratio 1.43 [95% CI 0.73, 2.78]; suicide: 1.75 [0.64, 4.38]), Olympic-style wrestlers (depression: 0.94 [0.44, 2.00]; suicide: 1.60 [0.64, 3.99]), and soccer players (depression: 0.62 [0.26, 1.48]; suicide: 0.50 [0.11, 2.16]) did not have statistically higher rates of major depressive disorder or suicide at follow-up relative to controls. In the systematic review, 7 cohort studies met inclusion criteria. After aggregating results with the Finnish cohort, retired soccer players appeared to have a lower risk of depression (summary risk ratio: 0.71 [0.54, 0.93]) relative to general population controls, while the rate of suicide was statistically the same across groups (0.70 [0.40, 1.23]). Past participation in American football seemed to be associated with some protection against suicide (0.58 [0.43, 0.80]) but there were insufficient studies of depression in this sport to facilitate aggregation. The aggregation of results from the soccer and American football studies showed directionally consistent relationships and there was no indication of inter-study heterogeneity (I2 = 0%). Interpretation: Based on a small cluster of studies exclusively comprising men, retired soccer players had a lower rate of later depression and former American football players had a lower risk of suicide relative to comparator groups. Whether these findings are generalisable to women requires testing. Funding: The preparation of this manuscript was unfunded

Extended-soft-core Baryon-Baryon Model II. Hyperon-Nucleon Interaction

The YN results are presented from the Extended-soft-core (ESC) interactions. They consist of local- and non-local-potentials due to (i) One-boson-exchange (OBE), with pseudoscalar-, vector-, scalar-, and axial-vector-nonets, (ii) Diffractive exchanges, (iii) Two-pseudoscalar exchange, and (iv) Meson-pair-exchange (MPE). This model, called ESC04, describes NN and YN in a unified way using broken flavor SU(3)-symmetry. Novel ingredients are the inclusion of (i) the axial-vector-mesons, (ii) a zero in the scalar- and axial-vector meson form factors. We describe simultaneous fits to the NN- and YN-data, using four options in the ESC-model. Very good fits were obtained. G-matrix calculations with these four options are also reported. The obtained well depths (U_\Lambda, U_\Sigma, U_\Xi) reveal distinct features of ESC04a-d. The \Lambda\Lambda-interactions are demonstrated to be consistent with the observed data of_{\Lambda\Lambda}^6He. The possible three-body effects are investigated by considering phenomenologically the changes of the vector-meson masses in a nuclear medium.Comment: preprint vesion 66 pages, two-column version 27 pages, 17 figure

Pion-Lambda-Sigma Coupling Extracted from Hyperonic Atoms

The latest measurements of the atomic level width in Sigma-hyperonic Pb atom offer the most accurate datum in the region of low-energy Sigma-hyperon physics. Atomic widths are due to the conversion of Sigma-nucleon into Lambda-nucleon. In high angular momentum states this conversion is dominated by the one-pion exchange. A joint analysis of the data of the scattering of negative-Sigma on proton converting into a Lambda and a neutron and of the atomic widths allows to extract a pseudovector pion-hyperon-Sigma coupling constant of 0.048 with a statistical error of +-0.005 and a systematic one of +-0.004. This corresponds to a pseudoscalar coupling constant of 13.3 with a statistical uncertainty of 1.4 and a systematic one of 1.1.Comment: 12 pages, 1 figure, Use of Revtex.st