A Microscopic Calculation of Photoabsorption Cross Sections on Protons and Nuclei

A recently developed model for $\rho$-meson propagation in dense hadronic matter is applied to total photoabsorption cross sections in $\gamma$-proton and $\gamma$-nucleus reactions. Within the vector dominance model the photon coupling to the virtual pion cloud of the nucleon, two-body meson-exchange currents, as well as $\gamma$-nucleon resonances are included. Whereas the $\gamma p$ reaction is determined by the low-density limit of the model, higher orders in the nuclear density are important to correctly account for the experimental spectra observed on both light and heavy nuclei over a wide range of photon energies, including the region below the pion threshold. In connection with soft dilepton spectra in high-energy heavy-ion collisions we emphasize the importance of photoabsorption to further constrain the parameters of the model.Comment: 10 pages RevTeX, 2 eps-figure

Momentum Dependence of the Pion Cloud for Rho Mesons in Nuclear Matter

We extend hadronic models for rho-meson propagation in cold nuclear matter via coupling to in-medium pions to include finite three-momentum. Special care is taken to preserve gauge invariance. Consequences for photoabsorption on the proton and on nuclei as well as for the dilepton production in relativistic heavy-ion collisions are discussed.Comment: 32 pages, 18 figures. Corrected version, accepted for publication in Nucl. Phys.

Lobster Eye X-ray optics for astrophysics: Recent status

X-ray optics in Lobster Eye arrangement represent promising complementary device to narrow field X-ray optics in common use. We present briefly recent status of design, developments, and tests of X-ray optics including Lobster Eye modules developed and tested within recent space project

The Shears Mechanism in 142Gd in the Skyrme-Hartree-Fock Method with the Tilted-Axis Cranking

We report on the first Skyrme-Hartree-Fock calculations with the tilted-axis cranking in the context of magnetic rotation. The mean field symmetries, differences between phenomenological and self-consistent methods and the generation of shears-like structures in the mean field are discussed. Significant role of the time-odd spin-spin effective interaction is pointed out. We reproduce the shears mechanism, but quantitative agreement with experiment is rather poor. It may have to do with too large core polarization, lack of pairing correlations or properties of the Skyrme force.Comment: Presented at the XXVII Mazurian Lakes School of Physics, September 2-9 2001, Krzyze, Poland, Submitted to Acta Physica Polonic

Averaged null energy condition violation in a conformally flat spacetime

We show that the averaged null energy condition can be violated by a conformally coupled scalar field in a conformally flat spacetime in 3+1 dimensions. The violation is dependent on the quantum state and can be made as large as desired. It does not arise from the presence of anomalies, although anomalous violations are also possible. Since all geodesics in conformally flat spacetimes are achronal, the achronal averaged null energy condition is likewise violated.Comment: 11 page

Reimagining quality in early childhood [Editorial]

This special issue brings together a collection of rich, complex and challenging contributions that attempt to offer generative approaches to reconfigure what might constitute ‘quality’ within early years education. The issue came about from a shared concern about what Moss (this issue) refers to as the ‘gravitational pull’ of quality in early childhood education; debates about quality have existed for a considerable time and, despite rigorous critique, remain resolute. This issue aims to revisit and extend the groundbreaking work undertaken by Gunilla Dahlberg, Peter Moss and Alan Pence (1999, 2007) in Beyond Quality in Early Childhood Education and Care: Postmodern Perspectives and in the subsequent revised edition. In both texts, the authors made the astute observation that the concept and language of quality cannot accommodate issues such as diversity and multiple perspectives, contextual specificity and subjectivity. They argue that we must ‘go beyond the concept of quality’ (Dahlberg et al., 2007: 6) and, in so doing, suggest working with a new concept: ‘meaning making’

Perturbation of magnetostatic modes observed by ferromagnetic resonance force microscopy

Magnetostatic modes of yttrium iron garnet (YIG) films are investigated by ferromagnetic resonance force microscopy. A thin-film "probe" magnet at the tip of a compliant cantilever introduces a local inhomogeneity in the internal field of the YIG sample. This influences the shape of the sample's magnetostatic modes, thereby measurably perturbing the strength of the force coupled to the cantilever. We present a theoretical model that explains these observations; it shows that the tip-induced variation of the internal field creates either a local "potential barrier" or "potential well" for the magnetostatic waves. The data and model together indicate that local magnetic imaging of ferromagnets is possible, even in the presence of long-range spin coupling, through the introduction of localized magnetostatic modes predicted to arise from sufficiently strong tip fields

Occupational Therapists\u27 Role in Sexual Education for Teens and Young Adults Living with Autism Spectrum Disorder

Teens and young adults living with autism spectrum disorder (ASD) do not have equal access to sexual education, thus having lower sexual awareness, little knowledge of preventative sexual health care, and having a more difficult time reading sexual body language (Hannah & Stagg, 2016; Holmes et al., 2019; Mogavero & Hsu, 2020). Deficits in these and many other skills may make it more challenging for teens and young adults living with ASD to engage in an intimate or sexual relationship with a consenting partner. Skilled intervention on the occupation of sexual activity and its related dimensions, such as communication and sensory input, is well within an occupational therapist\u27s scope of practice, yet there is little to no evidence supporting the role of occupational therapists serving clients living with ASD to address such topics. This manuscript will highlight the lack of sexual education supports for teens and young adults living with ASD and how occupational therapists can fill this important role as a trusted sexuality educator