Spin-Isospin Excitations and Muon Capture by Nuclei

By analyzing the energy-weighted moments of the strength function calculated in RPA and beyond it is shown that the explanation of the effect of missing strength of Gamow-Teller transitions requires that residual interaction produce high-excited $1^{+}$ particle-hole collective states. The example of this interaction is presented. The manifestations of spin-isospin nuclear response in nuclear muon capture are discussed.Comment: 16 pages, 5 figures, 2 tables. The talk at the XVI International School on Nuclear Physics, Neutron Physics and Nuclear Energy, September 19-26, Varna, Bulgari

Rings and arcs around evolved stars. II. The Carbon Star AFGL 3068 and the Planetary Nebulae NGC 6543, NGC 7009 and NGC 7027

We present a detailed comparative study of the arcs and fragmented ring-like features in the haloes of the planetary nebulae (PNe) NGC 6543, NGC 7009, and NGC 7027 and the spiral pattern around the carbon star AFGL 3068 using high-quality multi-epoch HST images. This comparison allows us to investigate the connection and possible evolution between the regular patterns surrounding AGB stars and the irregular concentric patterns around PNe. The radial proper motion of these features, ~15 km/s, are found to be consistent with the AGB wind and their linear sizes and inter-lapse times (500-1900 yr) also agree with those found around AGB stars, suggesting a common origin. We find evidence using radiative-hydrodynamic simulations that regular patterns produced at the end of the AGB phase become highly distorted by their interactions with the expanding PN and the anisotropic illumination and ionization patterns caused by shadow instabilities. These processes will disrupt the regular (mostly spiral) patterns around AGB stars, plausibly becoming the arcs and fragmented rings observed in the haloes of PNe.Comment: 13 pages, 9 figures, accepted for publication in MNRA

Previously Identified Genetic Variants in ADGRL3 Are not Associated with Risk for Equine Degenerative Myeloencephalopathy across Breeds.

Equine neuroaxonal dystrophy/equine degenerative myeloencephalopathy (eNAD/EDM) is a neurologic disease that has been reported in young horses from a wide range of breeds. The disease is inherited and associated with vitamin E deficiency during the first two years of life, resulting in bilateral symmetric ataxia. A missense mutation (chr3:71,917,591 C > T) within adhesion G protein-coupled receptor L3 (ADGRL3) was recently associated with risk for EDM in the Caspian breed. In order to confirm these findings, genotyping of this missense mutation, along with the three other associated single nucleotide polymorphisms (SNPs) in the genomic region, was carried out on 31 postmortem-confirmed eNAD/EDM cases and 43 clinically phenotyped controls from various breeds. No significant association was found between eNAD/EDM confirmed cases and genotype at any of the four identified SNPs (P > 0.05), including the nonsynonymous variant (EquCab2.0 chr3:71,917,591; allelic P = 0.85). These findings suggest that the four SNPs, including the missense variant in the ADGRL3 region, are not associated with risk for eNAD/EDM across multiple breeds of horses

Level sets of functions and symmetry sets of smooth surface sections

We prove that the level sets of a real C^s function of two variables near a non-degenerate critical point are of class C^[s/2] and apply this to the study of planar sections of surfaces close to the singular section by the tangent plane at hyperbolic points or elliptic points, and in particular at umbilic points. We also analyse the cases coming from degenerate critical points, corresponding to elliptic cusps of Gauss on a surface, where the differentiability is now reduced to C^[s/4]. However in all our applications to symmetry sets of families of plane curves, we assume the C^infty smoothness.Comment: 15 pages, Latex, 6 grouped figures. The final version will appear in Mathematics of Surfaces. Lecture Notes in Computer Science (2005

Stochastic density functional theory

Linear-scaling implementations of density functional theory (DFT) reach their intended efficiency regime only when applied to systems having a physical size larger than the range of their Kohn-Sham density matrix (DM). This causes a problem since many types of large systems of interest have a rather broad DM range and are therefore not amenable to analysis using DFT methods. For this reason, the recently proposed stochastic DFT (sDFT), avoiding exhaustive DM evaluations, is emerging as an attractive alternative linear-scaling approach. This review develops a general formulation of sDFT in terms of a (non)orthogonal basis representation and offers an analysis of the statistical errors (SEs) involved in the calculation. Using a new Gaussian-type basis-set implementation of sDFT, applied to water clusters and silicon nanocrystals, it demonstrates and explains how the standard deviation and the bias depend on the sampling rate and the system size in various types of calculations. We also develop basis-set embedded-fragments theory, demonstrating its utility for reducing the SEs for energy, density of states and nuclear force calculations. Finally, we discuss the algorithmic complexity of sDFT, showing it has CPU wall-time linear-scaling. The method parallelizes well over distributed processors with good scalability and therefore may find use in the upcoming exascale computing architectures

Defining multimorbidity in people with HIV - what matters most?

PURPOSE OF REVIEW: Although multimorbidity (defined as the coexistence of multiple conditions) presents significant health challenges to people with HIV, there is currently no consensus on how it should be defined among this population. This review aimed to examine the definition of multimorbidity in existing studies among people with HIV (n = 22). RECENT FINDINGS: Variation in the definition of multimorbidity (in terms of the number and nature of conditions included) across studies among people with HIV was observed, with less than half (45%) reporting a selection criteria for conditions. The number of conditions considered ranged from 4 to 65. Certain conditions (e.g. stroke, myocardial infarction and chronic kidney disease) and risk factors (e.g. hypertension) were more frequently included, while other symptoms (e.g. joint pain, peripheral neuropathy and sleeping problems) and mental health conditions (e.g. anxiety and panic attacks) were rarely included in the definition of multimorbidity. SUMMARY: The definition of multimorbidity among people with HIV is highly variable, with certain conditions overlooked. We propose recommendations that researchers should consider when defining multimorbidity among this population to not only enable comparisons between studies/settings but also to ensure studies consider a person-centred approach that can accurately capture multimorbidity among people with HIV

Dynamic analysis of a lithium-boiling potassium refractory metal Rankine cycle power system for the Jet Propulsion Laboratory

Lithium-boiling potassium refractory metal Rankine cycle power system heat transfer model