Dynamics of Chainlike Molecules on Surfaces

We consider the diffusion and spreading of chainlike molecules on solid surfaces. We first show that the steep spherical cap shape density profiles, observed in some submonolayer experiments on spreading polymer films, imply that the collective diffusion coefficient $D_C(\theta)$ must be an increasing function of the surface coverage $\theta$ for small and intermediate coverages. Through simulations of a discrete model of interacting chainlike molecules, we demonstrate that this is caused by an entropy-induced repulsive interaction. Excellent agreement is found between experimental and numerically obtained density profiles in this case, demonstrating that steep submonolayer film edges naturally arise due to the diffusive properties of chainlike molecules. When the entropic repulsion dominates over interchain attractions, $D_C(\theta)$ first increases as a function of $\theta$ but then eventually approaches zero for $\theta \to 1$. The maximum value of $D_C(\theta)$ decreases for increasing attractive interactions, leading to density profiles that are in between spherical cap and Gaussian shapes. We also develop an analytic mean field approach to explain the diffusive behavior of chainlike molecules. The thermodynamic factor in $D_C(\theta)$ is evaluated using effective free energy arguments, and the chain mobility is calculated numerically using the recently developed dynamic mean field theory. Good agreement is obtained between theory and simulations.Comment: 16 pages, 13 Postscript figure

In-reach specialist nursing teams for residential care homes : uptake of services, impact on care provision and cost-effectiveness

Background: A joint NHS-Local Authority initiative in England designed to provide a dedicated nursing and physiotherapy in-reach team (IRT) to four residential care homes has been evaluated.The IRT supported 131 residents and maintained 15 'virtual' beds for specialist nursing in these care homes. Methods: Data captured prospectively (July 2005 to June 2007) included: numbers of referrals; reason for referral; outcome (e.g. admission to IRT bed, short-term IRT support); length of stay in IRT; prevented hospital admissions; early hospital discharges; avoided nursing home transfers; and detection of unrecognised illnesses. An economic analysis was undertaken. Results: 733 referrals were made during the 2 years (range 0.5 to 13.0 per resident per annum)resulting in a total of 6,528 visits. Two thirds of referrals aimed at maintaining the resident's independence in the care home. According to expert panel assessment, 197 hospital admissions were averted over the period; 20 early discharges facilitated; and 28 resident transfers to a nursing home prevented. Detection of previously unrecognised illnesses accounted for a high number of visits. Investment in IRT equalled £44.38 per resident per week. Savings through reduced hospital admissions, early discharges, delayed transfers to nursing homes, and identification of previously unrecognised illnesses are conservatively estimated to produce a final reduction in care cost of £6.33 per resident per week. A sensitivity analysis indicates this figure might range from a weekly overall saving of £36.90 per resident to a 'worst case' estimate of £2.70 extra expenditure per resident per week. Evaluation early in implementation may underestimate some cost-saving activities and greater savings may emerge over a longer time period. Similarly, IRT costs may reduce over time due to the potential for refinement of team without major loss in effectiveness. Conclusion: Introduction of a specialist nursing in-reach team for residential homes is at least cost neutral and, in all probability, cost saving. Further benefits include development of new skills in the care home workforce and enhanced quality of care. Residents are enabled to stay in familiar surroundings rather than unnecessarily spending time in hospital or being transferred to a higher dependency nursing home setting

Interface Equations for Capillary Rise in Random Environment

We consider the influence of quenched noise upon interface dynamics in 2D and 3D capillary rise with rough walls by using phase-field approach, where the local conservation of mass in the bulk is explicitly included. In the 2D case the disorder is assumed to be in the effective mobility coefficient, while in the 3D case we explicitly consider the influence of locally fluctuating geometry along a solid wall using a generalized curvilinear coordinate transformation. To obtain the equations of motion for meniscus and contact lines, we develop a systematic projection formalism which allows inclusion of disorder. Using this formalism, we derive linearized equations of motion for the meniscus and contact line variables, which become local in the Fourier space representation. These dispersion relations contain effective noise that is linearly proportional to the velocity. The deterministic parts of our dispersion relations agree with results obtained from other similar studies in the proper limits. However, the forms of the noise terms derived here are quantitatively different from the other studies

Providing nursing support within residential care homes

This study examines a joint NHS-Local Authority initiative providing a dedicated nursing and physiotherapy team to three residential care homes in Bath and North East Somerset. The initiative aims to meet the nursing needs of residents where they live and to train care home staff in basic nursing. * Hospital admissions and nursing home transfers were prevented. Care home staff and managers preferred residents to be able to stay in their home when they were ill, as did residents themselves. * Enhancing health-orientated education and training of care home staff was challenging at first but relationships improved, and the confidence and professionalism of care staff grew. * Residents’ nursing needs cannot simply be equated with their level of dependency. For example, a resident with dementia can be functionally independent yet have major, often un-communicated health needs. * The early detection of illness and resulting opportunity for early intervention was a major part of the team’s work. Residents were likely to benefit from improved quality of life. * Overall, estimates of costs and savings ranged from a 'worst case' scenario of £2.70 extra to a more likely scenario of £36.90 saved per resident per week. Savings were mainly in reduced use of NHS services, while the Primary Care Trust and Adult Social Services both funded the intervention, highlighting the need for partnership working to sustain funding. * The researchers conclude that any increase in cost should be measured against the benefits of promoting long-term quality of life, quality of care and providing a firm foundation for future workforce development

Low Complexity Blind Equalization for OFDM Systems with General Constellations

This paper proposes a low-complexity algorithm for blind equalization of data in OFDM-based wireless systems with general constellations. The proposed algorithm is able to recover data even when the channel changes on a symbol-by-symbol basis, making it suitable for fast fading channels. The proposed algorithm does not require any statistical information of the channel and thus does not suffer from latency normally associated with blind methods. We also demonstrate how to reduce the complexity of the algorithm, which becomes especially low at high SNR. Specifically, we show that in the high SNR regime, the number of operations is of the order O(LN), where L is the cyclic prefix length and N is the total number of subcarriers. Simulation results confirm the favorable performance of our algorithm

Models for providing improved care in residential care homes: a thematic literature review

This Annotated Bibliography is one output from a review of the available research evidence to support improved care in residential care homes as the needs of older people intensify. Key findings The review identified extremely little published evidence on residential care homes; the research base is almost exclusively related to provision of care in nursing homes. Much of this research is from the US or other non-UK sources. Although it could be argued that some findings are generalisable to the UK residential care context, a systematic process is required to identify which. The literature often makes no distinction between nursing and residential homes; use of generic terms such as ‘care home’ should be avoided. There is considerable international debate in the quality improvement literature about the relationship between quality of care and quality of life in nursing and residential homes. Measures of social care, as well as clinical care, are needed. The centrality of the resident’s voice in measuring quality of life must be recognised. Ethnic minority residents are almost entirely absent from the quality improvement literature. Some clinical areas, internationally identified as key in terms of quality e.g. palliative care, are absent in the general nursing and residential home quality improvement literature. Others such as mental health (dementia and depression), diabetes, and nutrition are present but not fully integrated. Considerable evidence points to a need for better management of medication in nursing homes. Pharmacist medication reviews have shown a positive effect in nursing homes. It is unclear how this evidence might relate to residential care. There is evidence that medical cover for nursing and residential care home residents is suboptimal. Care could be restructured to give a greater scope for proactive and preventive interventions. General practitioners' workload in care homes may be considered against quality-of-care measures. There is US literature on the relationship between nurse staffing and nursing care home quality, with quality measured through clinical-based outcomes for residents and organisational outcomes. Conclusions are difficult to draw however due to inconsistencies in the evidencebase. Hospital admission and early discharge to nursing homes research may not be generalisable to residential care. The quality of inter-institutional transfers and ensuring patient safety across settings is important. To date research has not considered transfer from residential to nursing home care. The literature on district nurse and therapist roles in care homes includes very little research on residential care. Partnership working between district nurses and care home staff appears largely to occur by default at present. There is even less research evidence on therapist input to care homes. Set against the context outlined above, the international literature provides evidence of a number of approaches to care improvement, primarily in nursing homes. These include little discussion of cost-effectiveness other than in telecare. Research is needed in the UK on care improvement in residential homes

Comment on: `Pipe Network Model for Scaling of Dynamic Interfaces in Porous Media'

We argue that a proposed exponent identity [Phys. Rev. Lett 85, 1238 (2000)] for interface roughening in spontaneous imbibition is wrong. It rests on the assumption that the fluctuations are controlled by a single time scale, but liquid conservation imposes two distinct time scales.Comment: 1 page, to appear in Phys. Rev. Let

The short future of public broadcasting: Replacing digital terrestrial television with internet protocol?

According to recent European estimates, the life expectancy of broadcasting as a free-to-air television platform is not more than 15 years. BBC, Yle and the UK regulator Ofcom have reached this conclusion in their reports about the future of news, media distribution and digital terrestrial television (DTT). Although broadcasting is seen as necessary until 2030, all three assume that DTT can – under certain conditions – be replaced with delivery using internet protocol (IP). However, it seems that the idea of IPTV taking over DTT is just a sophisticated version of “black box fallacy”, driven by the expected growth of the new media ecosystem. The problems in replacing a socio-technological system have largely been neglected

Equilibrium shape and dislocation nucleation in strained epitaxial nanoislands

We study numerically the equilibrium shapes, shape transitions and dislocation nucleation of small strained epitaxial islands with a two-dimensional atomistic model, using simple interatomic pair potentials. We first map out the phase diagram for the equilibrium island shapes as a function of island size (up to N = 105 atoms) and lattice misfit with the substrate and show that nanoscopic islands have four generic equilibrium shapes, in contrast with predictions from the continuum theory of elasticity. For increasing substrate-adsorbate attraction, we find islands that form on top of a finite wetting layer as observed in Stranski-Krastanow growth. We also investigate energy barriers and transition paths for transitions between different shapes of the islands and for dislocation nucleation in initially coherent islands. In particular, we find that dislocations nucleate spontaneously at the edges of the adsorbate-substrate interface above a critical size or lattice misfit.Comment: 4 pages, 3 figures, uses wrapfig.sty and epsfig.st