Nuclear Physics with Electroweak Probes

In recent years, the italian theoretical Nuclear Physics community has played a leading role in the development of a unified approach, allowing for a consistent and fully quantitative description of the nuclear response to electromagnetic and weak probes. In this paper I review the main achievements in both fields, point out some of the open problems, and outline the most promising prospects.Comment: Invited Talk at the XII Workshop on Theoretical Nuclear Physics in Italy, Cortona, October 8-10, 200

Quantum Monte Carlo calculations of the one-body density matrix and excitation energies of silicon

Quantum Monte Carlo (QMC) techniques are used to calculate the one-body density matrix and excitation energies for the valence electrons of bulk silicon. The one-body density matrix and energies are obtained from a Slater-Jastrow wave function with a determinant of local density approximation (LDA) orbitals. The QMC density matrix evaluated in a basis of LDA orbitals is strongly diagonally dominant. The natural orbitals obtained by diagonalizing the QMC density matrix resemble the LDA orbitals very closely. Replacing the determinant of LDA orbitals in the wave function by a determinant of natural orbitals makes no significant difference to the quality of the wave function's nodal surface, leaving the diffusion Monte Carlo energy unchanged. The Extended Koopmans' Theorem for correlated wave functions is used to calculate excitation energies for silicon, which are in reasonable agreement with the available experimental data. A diagonal approximation to the theorem, evaluated in the basis of LDA orbitals, works quite well for both the quasihole and quasielectron states. We have found that this approximation has an advantageous scaling with system size, allowing more efficient studies of larger systems.Comment: 13 pages, 4 figures. To appear in Phys. Rev.

Superscaling in inclusive electron-nucleus scattering

We investigate the degree to which the scaling functions $F(\psi')$ derived from cross sections for inclusive electron-nucleus quasi-elastic scattering define the same function for different nuclei. In the region where the scaling variable $\psi'< 0$, we find that this superscaling is experimentally realized to a high degree.Comment: Corrected previously mislabeled figures and cross references; 9 pages, 4 color figures, using BoxedEPS and REVTeX; email correspondence to [email protected]

Interpretation of y-scaling of the nuclear response

The behavior of the nuclear matter response in the region of large momentum transfer, in which plane wave impulse approximation predicts the onset of y-scaling, is discussed. The theoretical analysis shows that scaling violations produced by final state interactions are driven by the momentum dependence of the nucleon-nucleon scattering cross section. Their study may provide valuable information on possible modifications of nucleon-nucleon scattering in the nuclear medium.Comment: 4 pages with 3 figures. To appear in Physical Review Letter

Rio high for Johnathan: shooter qualifies for olympics after bagging 1Om air pistol gold

Background and objective Previous research suggests that measures of cognitive process may be confounded by the inclusion of items that also assess cognitive content. The primary aims of this content review were to: (1) identify the domains of cognitive processes assessed by measures used in pain research; and (2) determine if pain‐specific cognitive process measures with adequate psychometric properties exist. Databases and data treatment PsychInfo, CINAHL, PsycArticles, MEDLINE, and Academic Search Complete databases were searched to identify the measures of cognitive process used in pain research. Identified measures were double coded and the measure's items were rated as: (1) cognitive content; (2) cognitive process; (3) behavioural/social; and/or (4) emotional coping/responses to pain. Results A total of 319 scales were identified; of these, 29 were coded as providing an un‐confounded assessment of cognitive process, and 12 were pain‐specific. The cognitive process domains assessed in these measures are Absorption, Dissociation, Reappraisal, Distraction/Suppression, Acceptance, Rumination, Non‐Judgment, and Enhancement. Pain‐specific, un‐confounded measures were identified for: Dissociation, Reappraisal, Distraction/Suppression, and Acceptance. Psychometric properties of all 319 scales are reported in supplementary material. Conclusions To understand the importance of cognitive processes in influencing pain outcomes as well as explaining the efficacy of pain treatments, valid and pain‐specific cognitive process measures that are not confounded with non‐process domains (e.g., cognitive content) are needed. The findings of this content review suggest that future research focused on developing cognitive process measures is critical in order to advance our understanding of the mechanisms that underlie effective pain treatment. Significance Many cognitive process measures used in pain research contain a ‘mix’ of items that assess cognitive process, cognitive content, and behavioural/emotional responses. Databases searched: PsychInfo, CINAHL, PsycArticles, MEDLINE and Academic Search Complete. This review describes the domains assessed by measures assessing cognitive processes in pain research, as well as the strengths and limitations of these measures

Cox-2 Inhibitors

Cyclooxygenase-2 (COX-2) inhibitors constitute a new group of non-steroidal anti-inflammatory drugs (NSAIDs) which, at recommended doses, block prostaglandin production by cyclooxygenase-2, but not by cyclooxygenase-1. Two COX-2 inhibitors are currently available in Australia--celecoxib, which is taken twice daily, and rofecoxib, which is taken once daily. Both drugs act rapidly in providing pain relief and their anti-inflammatory analgesic effect in osteoarthritis and rheumatoid arthritis is equivalent to standard doses of non-selective NSAIDs. Celecoxib and rofecoxib show significantly lower incidences of gastrotoxicity (as measured by endoscopic studies and gastrointestinal ulcers and bleeds) than non-selective NSAIDs. There is Level 2 evidence that COX-2 inhibitors: reduce pain in classic pain models--third-molar extraction, dysmenorrhoea and after orthopaedic surgery; reduce pain and disability in osteoarthritis of the hip and knee; and reduce pain and disability in rheumatoid arthritis. Other adverse effects, such as interference with antihypertensive agents and the potential to produce renal dysfunction in patients with compromised renal function by COX-2 inhibitors, seem similar to those of non-selective NSAIDs

Microwave Kinetic Inductance Detector (MKID) Camera Testing for Submillimeter Astronomy

Developing kilopixel focal planes for incoherent submm- and mm-wave detectors remains challenging due to either the large hardware overhead or the complexity of multiplexing standard detectors. Microwave kinetic inductance detectors (MKIDs) provide a efficient means to produce fully lithographic background-limited kilopixel focal planes. We are constructing an MKID-based camera for the Caltech Submillimeter Observatory with 576 spatial pixels each simultaneously sensitive in 4 bands at 230, 300, 350, and 400 GHz. The novelty of MKIDs has required us to develop new techniques for detector characterization. We have measured quasiparticle lifetimes and resonator Qs for detector bath temperatures between 200 mK and 400 mK. Equivalent lifetime measurements were made by coupling energy into the resonators either optically or by driving the third harmonic of the resonator. To determine optical loading, we use both lifetime and internal Q measurements, which range between 15,000 and 30,000 for our resonators. Spectral bandpass measurements confirm the placement of the 230 and 350 GHz bands. Additionally, beam maps measurements conform to expectations. The same device design has been characterized on both sapphire and silicon substrates, and for different detector geometries. We also report on the incorporation of new shielding to reduce detector sensitivity to local magnetic fields