Effects of weak anchoring on C1 and C2 chevron structures

We present a theoretical study of the effect of weak anchoring on the transition between C1 and C2 chevron structures in smectic C liquid crystals. We employ a continuum theory which allows for variable cone, azimuthal and layer tilt angles. Equilibrium profiles for the director cone and azimuthal angles in the C1 and C2 states are calculated from the standard Euler-Lagrange minimisation of the total energy of the system. By comparing the total energies of the C1 and C2 states we can determine the globally stable chevron profile and calculate the critical temperature for the C1-C2 transition, which depends on anchoring strength and pretilt angle variations

Distant radio galaxies in the near IR

We are carrying out a program of near IR imaging and spectroscopy of radio galaxies with redshifts of 1.5 and greater. One of its principal goals is to constrain the ages and star formation histories of massive galaxies at early epochs. The radio galaxies are drawn from the survey of 1Jy class sources by McCarthy et al (1989) and McCarthy (1990). The sample contains 18 radio galaxies with redshifts greater than 2 and an additional 10 objects with 1.5 less than z less than 2.0. The redshifts were obtained from long slit spectra with the CTIO 4 m. While the galaxies are quite faint (r approximately = 21-24.5) all have Lyman alpha emission with rest frame equivalent widths of 100 - 1000 A. Multicolor photometry in the g,r,i and J,H,K bands has been obtained with the 2.5-m Du Pont Telescope on Las Campanas and with the Hale 5 m telescope at Palomar. We have recently obtained near IR spectra, using the 4 m telescopes at KPNO and CTIO, of a few objects with the goal of determining the Lyman alpha/H-alpha ratio and hence the reddening

Zenithal bistability in a nematic liquid crystal device with a monostable surface condition

The ground-state director configurations in a grating-aligned, zenithally bistable nematic device are calculated in two dimensions using a Q tensor approach. The director profiles generated are well described by a one-dimensional variation of the director across the width of the device, with the distorted region near the grating replaced by an effective surface anchoring energy. This work shows that device bistability can in fact be achieved by using a monostable surface term in the one-dimensional model. This implies that is should be possible to construct a device showing zenithal bistability without the need for a micropatterned surface

Discovery of a Color-Selected Quasar at z=5.50

We present observations of RD J030117+002025, a quasar at z=5.50 discovered from deep, multi-color, ground-based observations covering 74 square arcmin. This is the most distant quasar or AGN currently known. The object was targeted as an R-band dropout, with R(AB)>26.3 (3-sigma limit in a 3 arcsec diameter region), I(AB)=23.8, and z(AB)=23.4. The Keck/LRIS spectrum shows broad Lyman-alpha/NV emission and sharp absorption decrements from the highly-redshifted hydrogen forests. The fractional continuum depression due to the Lyman-alpha forest is D(A)=0.90. RD J030117+002025 is the least luminous, high-redshift quasar known (M(B)~-22.7).Comment: 9 pages, 2 figures; to appear in the The Astrophysical Journal Letter

Coupled surface plasmons and optical guided wave exploration of near-surface director profile

Copyright © 2007 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft. This is the published version of an article published in New Journal of Physics Vol. 9, article 49. DOI: 10.1088/1367-2630/9/3/049For a liquid crystal (LC) cell with thin silver claddings it is possible, using a high index coupling prism, to excite both surface plasmon modes and ordinary optical guided modes. In a situation where the tilt of the director varies from homogeneous to homeotropic through the cell, then for p-polarized incident radiation the p-polarized surface plasmon mode and the ordinary guided waves may couple to each other. When the plane containing the director is normal to the incident plane, there is also polarization conversion leading to strong coupling between the p-polarized surface plasmon and s-like guided modes. From theoretical analyses together with numerical modelling it is shown how this coupling between the surface plasmon mode and guided waves gives a high sensitivity to the surface director tilt profile near the walls, higher than that of the surface plasmon mode alone. Experimental confirmation of this has been realized using a hybrid aligned nematic (HAN) LC cell with the director in a plane normal to the incident plane. The results fully confirm the model predictions showing that this coupling of surface plasmons to guided waves provides a powerful tool for near-surface director studies

Effectiveness of a targeted telephone-based case management service on activity in an Emergency Department in the UK: a pragmatic difference-in-differences evaluation.

BACKGROUND: This study evaluates the effectiveness of a targeted telephone-based case management service that aimed to reduce ED attendance amongst frequent attenders, known to disproportionately contribute to demand. Evidence on the effectiveness of these services varies. METHODS: A 24-month controlled before-and-after study, following 808 patients (128 cases and 680 controls (41 were non-compliant)) who were offered the service in the first four months of operation within a UK ED department. Patients stratified as high-risk of reattending ED within 6 months by a predictive model were manually screened. Those positively reviewed were offered a non-clinical, nurse-led, telephone-based health coaching, consisting of care planning, coordination and goal setting for up to 9 months. Service effectiveness was estimated using a difference-in-differences (DiD) analysis. Incident rate of ED and Minor Injury Unit (MIU) attendances and average length of stay in intervention recipients and controls over 12 months after receiving their service offer following ED attendance were compared, adjusting for the prior 12-month period, sex and age, to give an incidence rate ratio (IRR). RESULTS: Intervention recipients were more likely to be female (63.3% versus 55.4%), younger (mean of 69 years versus 76 years), and have higher levels of ED activity (except for MIU) than controls. Mean rates fell between periods for all outcomes (except for MIU attendance). The Intention-to-Treat analysis indicated non-statistically significant effect of the intervention in reducing all outcomes, except for MIU attendances, with IRRs: ED attendances, 0.856 (95% CI: 0.631, 1.160); ED admissions, 0.871 (95% CI: 0.628, 1.208); length of stay for emergency and elective admissions: 0.844 (95% CI: 0.619, 1.151) and 0.781 (95% CI: 0.420, 1.454). MIU attendance increased with an IRR: 2.638 (95% CI: 1.041, 6.680). CONCLUSIONS: Telephone-based health coaching appears to be effective in reducing ED attendances and admissions, with shorter lengths of stay, in intervention recipients over controls. Future studies need to capture outcomes beyond acute activity, and better understand how services like this provide added value

Integrating the voluntary sector in personalised care: mixed methods study of the outcomes from wellbeing co-ordination for adults with complex needs

PurposeThis integrated care study seeks to highlight how voluntary sector “wellbeing co-ordinators” co-located in a horizontally and vertically integrated, multidisciplinary community hub within one locality of an Integrated Care Organisation contribute to complex, person-centred, co-ordinated care.Design/methodology/approachThis is a naturalistic, mixed method and mixed data study. It is complementing a before-and-after study with a sub-group analysis of people receiving input from the wider hub (including Wellbeing Co-ordination and Enhanced Intermediate Care), qualitative case studies, interviews, and observations co-produced with embedded researchers-in-residence.FindingsThe cross-case analysis uses trajectories and outcome patterns across six client groups to illustrate the bio-psycho-social complexity of each group across the life course, corresponding with the range of inputs offered by the hub.Research limitations/implicationsTo consider the effectiveness and mechanisms of complex system-wide interventions operating at horizontal and vertical interfaces and researching this applying co-produced, embedded, naturalistic and mixed methods approaches.Practical implicationsHow a bio-psycho-social approach by a wellbeing co-ordinator can contribute to improved person reported outcomes from a range of preventive, rehabilitation, palliative care and bereavement services in the community.Social implicationsTo combine knowledge about individuals held in the community to align the respective inputs, and expectations about outcomes while considering networked pathways based on functional status, above diagnostic pathways, and along a life-continuum.Originality/valueThe hub as a whole seems to (1) Enhance engagement through relationship, trust and activation, (2) Exchanging knowledge to co-create a shared bio-psycho-social understanding of each individual’s situation and goals, (3) Personalising care planning by utilising the range of available resources to ensure needs are met, and (4) Enhancing co-ordination and ongoing care through multi-disciplinary working between practitioners, across teams and sectors.</jats:sec