On the density-potential mapping in time-dependent density functional theory

The key questions of uniqueness and existence in time-dependent density functional theory are usually formulated only for potentials and densities that are analytic in time. Simple examples, standard in quantum mechanics, lead however to non-analyticities. We reformulate these questions in terms of a non-linear Schr\"odinger equation with a potential that depends non-locally on the wavefunction.Comment: 8 pages, 2 figure

Density functional approach for inhomogeneous star polymers

We propose microscopic density functional theory for inhomogeneous star polymers. Our approach is based on fundamental measure theory for hard spheres, and on Wertheim's first- and second-order perturbation theory for the interparticle connectivity. For simplicity we consider a model in which all the arms are of the same length, but our approach can be easily extended to the case of stars with arms of arbitrary lengths.Comment: 4 pages, 3 figures, submitte

Seasonal and spatial variability in the optical characteristics of DOM in a temperate shelf sea

The Celtic Sea is a productive temperate sea located on the Northwest European Shelf. It is an important pathway for the delivery of land-derived material to the North Atlantic Ocean, including dissolved organic matter (DOM). The aim of this study was to determine the seasonal and spatial variability in the magnitude, source and composition of DOM at three sites representing on shelf, central shelf and shelf edge regions in the Celtic Sea, using observations collected during the UK Shelf Sea Biogeochemistry (SSB) research programme (November 2014 – August 2015). The concentration of dissolved organic carbon (DOC) alongside DOM absorbance and fluorescence indices were measured and fluorescence Excitation and Emission Matrices (EEMs) combined with Parallel Factor Analysis (PARAFAC) were used to assess DOM composition and lability. The PARAFAC model identified four unique fluorescent components for autumn (November 2014), winter (March 2015), spring (April 2015) and summer (July 2015) consisting of two humic-like components attributed to terrestrial (C1) and marine sources (C2), and two protein components identified as tyrosine-like (C3) and tryptophan-like (C4) attributed to in situ production. DOC varied seasonally and there were strong cross shelf trends. The protein components (C3 and C4) exhibited large seasonal and within season variability particularly during productive periods. In contrast, there were persistent cross shelf gradients in the CDOM absorption coefficient at 305 nm (a305), the UV specific absorbance at 280 nm (SUVA280), the humification index (HIX), and the humic-like fluorescent components (C1 and C2), which were higher in the on shelf region and decreased towards the shelf edge. The humic-like components and the slope ratio (SR) were significantly correlated with salinity throughout all seasons, indicating a strong influence of terrestrially-derived organic matter in the Celtic Sea, with potentially up to 35% of DOC in the central shelf during winter originating from terrestrial inputs. Results from this study illustrate the importance of monitoring DOM quantitatively and qualitatively for a better understanding of the supply, production, cycling and export of this dynamic organic carbon pool in shelf seas

Healthier prisons: The role of a prison visitors' centre

Since the inception of the prison as a ‘setting’ for health promotion, there has been a focus on how the health of those men and women who spend ‘time inside’ can at least be maintained and if possible, enhanced, during their prison sentence. This paper presents findings from a mainly qualitative evaluation of a prison visitors' centre in the UK. It reports experiences of prisoners' families, prisoners, prison staff, the local community and the ways in which the visitors' centre has contributed positively to their health and well-being. In addition, key stakeholders were interviewed to ascertain the role this visitors' centre has in policy frameworks related to re-offending. The findings from this evaluation underscore how the visitors' centre improved the quality of visits, and contributed towards the maintenance of family ties through the help and support it provides for families and prisoners. The paper concludes by suggesting that visitors' centres are an essential part of a modern prison service helping to address the government's health inequalities agenda

Magnetism-induced massive Dirac spectra and topological defects in the surface state of Cr-doped Bi2_2Se3_3-bilayer topological insulators

Proximity-induced magnetic effects on the surface Dirac spectra of topological insulators are investigated by scanning tunneling spectroscopic (STS) studies of bilayer structures consisting of undoped Bi2Se3 thin films on top of Cr-doped Bi2Se3 layers. For thickness of the top Bi2Se3 layer equal to or smaller than 3 quintuple layers (QL), a spatially inhomogeneous surface spectral gap \Delta opens up below T_c^{2D}, which is much higher than the bulk Curie temperature T_c^{3D}. The mean value and spatial homogeneity of the gap \Delta generally increase with increasing c-axis magnetic field (H) and increasing Cr doping level (x), suggesting that the physical origin of this surface gap is associated with proximity-induced c-axis ferromagnetism. On the other hand, the temperature (T) dependence of \Delta is non-monotonic, showing an initial increase below T_c^{2D} followed by a dip and then reaching maximum at T << T_c^{3D}. These phenomena may be attributed to proximity magnetism induced by two types of contributions with different temperature dependence: a 3D contribution from the bulk magnetism that dominates at low T, and a 2D contribution associated with the RKKY interactions mediated by surface Dirac fermions, which dominates at T_c^{3D} << T < T_c^{2D}. Additionally, spatially localized sharp resonant spectra are found along the boundaries of gapped and gapless regions. These spectral resonances are long-lived at H = 0 and become suppressed under strong c-axis magnetic fields, and are attributed to magnetic impurity-induced topological defects in the spin texture of surface Dirac fermions.Comment: Manuscript 14 pages, 6 figures. Supplementary Information 7 pages. Accepted for publication in New Journal of Physics (2015

Assessing researchers\u27 capabilities, opportunities, and motivation to conduct equity-oriented dissemination and implementation research, an exploratory cross-sectional study

BACKGROUND: A recent paradigm shift has led to an explicit focus on enhancing health equity through equity-oriented dissemination and implementation (D&I) research. However, the integration and bidirectional learning across these two fields is still in its infancy and siloed. This exploratory study aimed to examine participants\u27 perceived capabilities, opportunities, and motivations to conduct equity-oriented D&I research. METHODS: We conducted an exploratory cross-sectional survey distributed online from December 2020 to April 2021. Participants were recruited at either D&I or health disparities-oriented conferences, meetings, through social media, or personal outreach via emails. Informed by the Capability, Opportunity, and Motivation Model (COM-B), the survey queried respondents about different aspects of engaging in and conducting equity-oriented D&I research. All analyses were conducted in SPSS Version 27.0. RESULTS: A total of 180 participants responded to the survey. Most participants were women (81.7%), white (66.1%), academics (78.9%), and faculty members (53.9%). Many reported they were advanced (36.7%) or advanced beginners (27.8%) in the D&I field, and a substantial proportion (37.8%) reported being novice in D&I research that focused on health equity. Participants reported high motivation (e.g., 62.8% were motivated to apply theories, models, frameworks for promoting health equity in D&I research), but low capability to conduct equity-oriented D&I research (e.g., 5% had the information needed for promoting health equity in D&I research). Most participants (62.2%) reported not having used measures to examine equity in their D&I projects, and for those who did use measures, they mainly used individual-level measures (vs. organizational- or structural-level measures). When asked about factors that could influence their ability to conduct equity-oriented D&I research, 44.4% reported not having the skills necessary, and 32.2% stated difficulties in receiving funding for equity-oriented D&I research. CONCLUSIONS: Study findings provide empirical insight into the perspectives of researchers from different backgrounds on what is needed to conduct equity-oriented D&I research. These data suggest the need for a multi-pronged approach to enhance the capability and opportunities for conducting equity-oriented D&I work, such as: training specifically in equity-oriented D&I, collaboration between D&I researchers with individuals with expertise and lived experience with health equity research, funding for equity-oriented D&I research, and recognition of the value of community engaged research in promotion packages

Identifying Very Preterm Children at Educational Risk Using a School Readiness Framework

OBJECTIVES: Children born very preterm (VPT) are at high risk of educational delay, yet few guidelines exist for the early identification of those at greatest risk. Using a school readiness framework, this study examined relations between preschool neuro-developmental functioning and educational outcomes to age 9 years.METHODS: The sample consisted of a regional cohort of 110 VPT (≤32 weeks' gestation) and 113 full-term children born during 1998-2000. At corrected age 4 years, children completed a multidisciplinary assessment of their health/motor development, socioemotional adjustment, core learning skills, language, and general cognition. At ages 6 and 9, children's literacy and numeracy skills were assessed using the Woodcock-Johnson III Tests of Achievement.RESULTS: Across all readiness domains, VPT children were at high risk of delay/impairment (odds ratios 2.5-3.5). Multiple problems were also more common (47% vs 16%). At follow-up, almost two-thirds of VPT children were subject to significant educational delay in either literacy, numeracy or both compared with 29% to 31% of full-term children (odds ratios 3.4-4.4). The number of readiness domains affected at age 4 strongly predicted later educational risk, especially when multiple problems were present. Receiver operating characteristic analysis confirmed ≥2 readiness problems as the optimal threshold for identifying VPT children at educational risk.CONCLUSIONS: School readiness offers a promising framework for the early identification of VPT children at high educational risk. Findings support the utility of ≥2 affected readiness domains as an effective criterion for referral for educational surveillance and/or additional support during the transition to school.</p

Crystal field effects on the reactivity of aluminum-copper cluster anions

The limits and useful modifications of the jellium model are of great interest in understanding the properties of metallic clusters, especially involving bimetallic systems. We have measured the relative reactivity of CuAl−n clusters (n=11–34) with O2. An odd-even alternation is observed that is in accordance with spin-dependant etching, and CuAl−22is observed as a “magic peak.” The etching resistance of CuAl−22 is explained by an unusually large splitting of the 2D10 subshell that occurs because of a geometric distortion of the cluster that may also be understood as a crystal field splitting of the superatomic orbitals