A theoretical description of energy spectra and two-neutron separation energies for neutron-rich zirconium isotopes

Very recently the atomic masses of neutron-rich Zr isotopes, from $^{96}$Zr to $^{104}$Zr, have been measured with high precision. Using a schematic Interacting Boson Model (IBM) Hamiltonian, the evolution from spherical to deformed shapes along the chain of Zr isotopes, describing at the same time the excitation energies as well as the two-neutron separation energies, can be rather well reproduced. The interplay between phase transitions and configuration mixing of intruder excitations in this mass region is succinctly addressed.Comment: Accepted in European Journal of Physics

Nuclear binding energies: Global collective structure and local shell-model correlations

Nuclear binding energies and two-neutron separation energies are analyzed starting from the liquid-drop model and the nuclear shell model in order to describe the global trends of the above observables. We subsequently concentrate on the Interacting Boson Model (IBM) and discuss a new method in order to provide a consistent description of both, ground-state and excited-state properties. We address the artefacts that appear when crossing mid-shell using the IBM formulation and perform detailed numerical calculations for nuclei situated in the 50-82 shell. We also concentrate on local deviations from the above global trends in binding energy and two-neutron separation energies that appear in the neutron-deficient Pb region. We address possible effects on the binding energy, caused by mixing of low-lying $0^{+}$ intruder states into the ground state, using configuration mixing in the IBM framework. We also study ground-state properties using a deformed mean-field approach. Detailed comparisons with recent experimental data in the Pb region are amply discussed.Comment: 69 pages, TeX (ReVTeX). 23 eps figures. 1 table. Modified version. Accepted in Nucl. Phys.

Mean field study of structural changes in Pt isotopes with the Gogny interaction

The evolution of the nuclear shapes along the triaxial landscape is studied in the Pt isotopic chain using the selfconsistent Hartree-Fock-Bogoliubov approximation based on the Gogny interaction. In addition to the parametrization D1S, the new incarnations D1N and D1M of this force are also included in our analysis to asses to which extent the predictions are independent of details of the effective interaction. The considered range of neutron numbers 88<N<26 includes prolate, triaxial, oblate and spherical ground state shapes and serves for a detailed comparison of the predictions obtained with the new sets D1N and D1M against the ones provided by the standard parametrization Gogny-D1S in a region of the nuclear landscape for which experimental and theoretical fingerprints of shape transitions have been found. Structural evolution along the Pt chain is discussed in terms of the deformation dependence of single particle energies.Comment: 18 pages, 10 figures. Accepted for publication in Phys. Rev.

Proton-neutron quadrupole interactions: an effective contribution to the pairing field

We point out that the proton-neutron energy contribution, for low multipoles (in particular for the quadrupole component), effectively renormalizes the strength of the pairing interaction acting amongst identical nucleons filling up a single-j or a set of degenerate many-j shells. We carry out the calculation in lowest-order perturbation theory. We perform a study of this correction in various mass regions. These results may have implications for the use of pairing theory in medium-heavy nuclei and for the study of pairing energy corrections to the liquid drop model when studying nuclear masses.Comment: 19 pages, TeX, 3 tables, 2 figures. Accepted in PR

Prognostic Value of Bone Scintigraphy in Cancer Patients With Osteonecrosis of the Jaw

identifying imaging predictors of healing of osteonecrosis of the jaw (ONJ) in cancer patients may assist in better stratification of treatment strategies. MATERIALS AND METHODS: patients with ONJ were followed prospectively and underwent bone scintigraphy, both planar and single-photon emission computed tomography (SPECT) imaging. End points were time to healing and the number of recurrences. Studied parameters included lesion visibility, pattern of uptake, and quantification of uptake relative to the unaffected side. RESULTS: a total of 22 patients were recruited (3 men; 19 women) with a stage 1 ONJ lesion in 8, stage 2 in 9, and stage 3 ONJ in 5 patients. Median duration of follow-up was 12 months (range, 6-37). SPECT acquisitions proved superior over planar images in detecting ONJ lesions (P = 0.03). Quantification of tracer uptake in the ONJ lesion relative to the unaffected side showed increasing uptake with higher stages of ONJ: mean, 1.67 (95% confidence interval [CI], 1.17-2.18) in stage 1, 2.72 (95% CI, 2.24-3.20) in stage 2, and 4.62 (95% CI, 3.98-5.26) in stage 3. In addition, this relative ratio of uptake was found to be an independent predictor of ONJ healing (hazard ratio, 0.24; 95% CI, 0.07-0.82; P = 0.02). Neither ONJ stage nor relative ratio of uptake were predictors of the occurrence of ONJ relapses. CONCLUSIONS: bone scintigraphy in patients with ONJ is feasible and SPECT acquisitions are preferred over planar images. Relative quantification of tracer uptake provides prognostic information independent of clinical stage that may assist in identifying patients with a poor prognosis

Intruder bands and configuration mixing in the lead isotopes

A three-configuration mixing calculation is performed in the context of the interacting boson model with the aim to describe recently observed collective bands built on low-lying $0^+$ states in neutron-deficient lead isotopes. The configurations that are included correspond to the regular, spherical states as well as two-particle two-hole and four-particle four-hole excitations across the Z=82 shell gap.Comment: 20 pages, 4 figures, accepted by PRC, reference added for section 1 in this revised versio

Perceived discrimination is associated with severity of positive and depression/anxiety symptoms in immigrants with psychosis: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Immigration status is a significant risk factor for psychotic disorders, and a number of studies have reported more severe positive and affective symptoms among immigrant and ethnic minority groups. We investigated if perceived discrimination was associated with the severity of these symptoms among immigrants in Norway with psychotic disorders.</p> <p>Methods</p> <p>Cross-sectional analyses of 90 immigrant patients (66% first-generation, 68% from Asia/Africa) in treatment for psychotic disorders were assessed for DSM-IV diagnoses with the Structured Clinical Interview for DSM Disorders (SCID-I, sections A-E) and for present symptom severity by The Structured Positive and Negative Syndrome Scale (SCI-PANSS). Perceived discrimination was assessed by a self-report questionnaire developed for the Immigrant Youth in Cultural Transition Study.</p> <p>Results</p> <p>Perceived discrimination correlated with positive psychotic (r = 0.264, p < 0.05) and depression/anxiety symptoms (r = 0.282, p < 0.01), but not negative, cognitive, or excitement symptoms. Perceived discrimination also functioned as a partial mediator for symptom severity in African immigrants. Multiple linear regression analyses controlling for possible confounders revealed that perceived discrimination explained approximately 10% of the variance in positive and depression/anxiety symptoms in the statistical model.</p> <p>Conclusions</p> <p>Among immigrants with psychotic disorders, visible minority status was associated with perceived discrimination and with more severe positive and depression/anxiety symptoms. These results suggest that context-specific stressful environmental factors influence specific symptom patterns and severity. This has important implications for preventive strategies and treatment of this vulnerable patient group.</p

The Role of Free Pericranium Grafts in Augmentation Rhinoplasty

Various tissues and materials have been used in augmentation rhinoplasty. This paper presents a retrospective analysis of 14 patients, 8 female and 6 male, in whom free pericranium grafts were used in order to restore postsurgery or posttraumatic nasal defects. There were no complications from either the donor or the recipient site. The;early and medium term results were satisfactory. It is concluded that free pericranium, compared with other autografts, is a good alternative due to its several advantages and hardly any disadvantages. In selected cases it can even be the material of choice