Friedmann Equations from Entropic Force

In this note by use of the holographic principle together with the equipartition law of energy and the Unruh temperature, we derive the Friedmann equations of a Friedmann-Robertson-Walker universe.Comment: latex, 8 pages, v2: minor modifications and to appear in PRD (Rapid Communication

Approach to the extremal limit of the Schwarzschild-de Sitter black hole

The quasinormal-mode spectrum of the Schwarzschild-de Sitter black hole is studied in the limit of near-equal black-hole and cosmological radii. It is found that the mode_frequencies_ agree with the P"oschl-Teller approximation to one more order than previously realized, even though the effective_potential_ does not. Whether the spectrum approaches the limiting one uniformly in the mode index is seen to depend on the chosen units (to the order investigated). A perturbation framework is set up, in which these issues can be studied to higher order in future.Comment: REVTeX4, 4pp., no figures. N.B. "Alec" is my first, and "Maassen van den Brink" my family name. v2: added numerical verificatio

Improving coding and primary care management for people with Chronic Kidney Disease: an observational controlled study in east London

Background: The UK national chronic kidney disease (CKD) audit in primary care shows diagnostic coding in the electronic health record for CKD averages 70%, with wide practice variation. Coding is associated with improvements to risk factor management; CKD cases coded in primary care have lower rates of unplanned hospital admission. Aim: To increase diagnostic coding of CKD (stages 3–5) and primary care management, including blood pressure to target and prescription of statins to reduce cardiovascular disease risk. Design and setting: Controlled, cross-sectional study in four East London clinical commissioning groups (CCGs). Method: Interventions to improve coding formed part of a larger system change to the delivery of renal services in both primary and secondary care in East London. Quarterly anonymised data on CKD coding, blood pressure values, and statin prescriptions were extracted from practice computer systems for 1-year pre- and post-initiation of the intervention. Results: Three intervention CCGs showed significant coding improvement over a 1 year period following the intervention (regression for post-intervention trend P<0.001). The CCG with highest coding rates increased from 76–90% of CKD cases coded; the lowest coding CCG increased from 52–81%. The comparison CCG showed no change in coding rates. Combined data from all practices in the intervention CCGs showed a significant increase in the proportion of cases with blood pressure achieving target levels (difference in proportion P<0.001) over the 2-year study period. Differences in statin prescribing were not significant. Conclusion: Clinically important improvements to coding and management of CKD in primary care can be achieved by quality improvement interventions that use shared data to track and monitor change supported by practice-based facilitation. Alignment of clinical and CCG priorities and the provision of clinical targets, financial incentives, and educational resource were additional important elements of the intervention

Public engagement with research: Citizens’ views on motivations, barriers and support

Responsible research and innovation (RRI) approaches that have emerged in the past ten years point to the importance of engaging the public in dialogues about research. The different variants of RRI share the notion that societal actors, including citizens, need to work together – that is, engage in two-way communication during the research and innovation process – in order to better align both the process and its outcomes with the values, needs and expectations of society. Yet, sponsors and organizers of dialogues about research often face difficulties in recruiting sufficient numbers of participants or ensuring a sufficient level of diversity of participants. This paper asks what motivates or hinders individual citizens as members of the broader public to participate in such dialogues. It presents empirical findings of the European Union-funded project Promoting Societal Engagement Under the Terms of RRI (PROSO), which aimed to foster public engagement with research for RRI. PROSO used a quasi-experimental, qualitative approach directly involving citizens to address this question. The core of the innovative methodology were focus group discussions with European citizens about hypothetical opportunities to take part in dialogues about research. Three hypothetical scenarios of different dialogue formats (varied by whether they seek to inform the participants, consult or enable deeper collaboration on a scientific issue) were used as stimuli to explore the participants’ willingness (motivations and perceived barriers) to engage with scientific research. Our findings show a preference towards dialogue formats that give citizens a more active role and a greater say in research policy or research funding. They further suggest that those who seek to broaden citizen participation in dialogues about research should consider the role of relevance, impact, trust, legitimacy, knowledge, and time and resources as factors that can motivate or discourage citizens to take part. Based on our findings, we discuss possibilities to promote citizen participation in dialogues about research as part of putting RRI into practice

Long-term stability of short-term intensive language–action therapy in chronic aphasia: A 1–2 year follow-up study

Background. Intensive aphasia therapy can improve language functions in chronic aphasia over a short therapy interval of 2-4 weeks. For one intensive method, intensive language-action therapy, beneficial effects are well documented by a range of randomized controlled trials. However, it is unclear to date whether therapy-related improvements are maintained over years. Objective. The current study aimed at investigating long-term stability of ILAT treatment effects over circa 1-2 years (8-30 months). Methods. 38 patients with chronic aphasia participated in ILAT and were re-assessed at a follow-up assessment 8-30 months after treatment, which had been delivered 6-12.5 hours per week for 2-4 weeks. Results. A standardized clinical aphasia battery, the Aachen Aphasia Test, revealed significant improvements with ILAT that were maintained for up to 2.5 years. Improvements were relatively better preserved in comparatively young patients (<60 years). Measures of communicative efficacy confirmed improvements during intensive therapy but showed inconsistent long-term stability effects. Conclusions. The present data indicate that gains resulting from intensive speech-language therapy with ILAT are maintained up to 2.5 years after the end of treatment. We discuss this novel finding in light of a possible move from sparse to intensive therapy regimes in clinical practice

A note on quasinormal modes: A tale of two treatments

There is an apparent discrepancy in the literature with regard to the quasinormal mode frequencies of Schwarzschild-de Sitter black holes in the degenerate-horizon limit. On the one hand, a Poschl-Teller-inspired method predicts that the real part of the frequencies will depend strongly on the orbital angular momentum of the perturbation field whereas, on the other hand, the degenerate limit of a monodromy-based calculation suggests there should be no such dependence (at least, for the highly damped modes). In the current paper, we provide a possible resolution by critically re-assessing the limiting procedure used in the monodromy analysis.Comment: 11 pages, Revtex format; (v2) new addendum in response to reader comments, also references, footnote and acknowledgments adde

Riemann solvers and undercompressive shocks of convex FPU chains

We consider FPU-type atomic chains with general convex potentials. The naive continuum limit in the hyperbolic space-time scaling is the p-system of mass and momentum conservation. We systematically compare Riemann solutions to the p-system with numerical solutions to discrete Riemann problems in FPU chains, and argue that the latter can be described by modified p-system Riemann solvers. We allow the flux to have a turning point, and observe a third type of elementary wave (conservative shocks) in the atomistic simulations. These waves are heteroclinic travelling waves and correspond to non-classical, undercompressive shocks of the p-system. We analyse such shocks for fluxes with one or more turning points. Depending on the convexity properties of the flux we propose FPU-Riemann solvers. Our numerical simulations confirm that Lax-shocks are replaced by so called dispersive shocks. For convex-concave flux we provide numerical evidence that convex FPU chains follow the p-system in generating conservative shocks that are supersonic. For concave-convex flux, however, the conservative shocks of the p-system are subsonic and do not appear in FPU-Riemann solutions

An International Study of the Ability and Cost-Effectiveness of Advertising Methods to Facilitate Study Participant Self-Enrolment Into a Pilot Pharmacovigilance Study During Early Pregnancy

Knowledge of the fetal effects of maternal medication use in pregnancy is often inadequate and current pregnancy pharmacovigilance (PV) surveillance methods have important limitations. Patient self-reporting may be able to mitigate some of these limitations, providing an adequately sized study sample can be recruited.To compare the ability and cost-effectiveness of several direct-to-participant advertising methods for the recruitment of pregnant participants into a study of self-reported gestational exposures and pregnancy outcomes.The Pharmacoepidemiological Research on Outcomes of Therapeutics by a European Consortium (PROTECT) pregnancy study is a non-interventional, prospective pilot study of self-reported medication use and obstetric outcomes provided by a cohort of pregnant women that was conducted in Denmark, the Netherlands, Poland, and the United Kingdom. Direct-to-participant advertisements were provided via websites, emails, leaflets, television, and social media platforms.Over a 70-week recruitment period direct-to-participant advertisements engaged 43,234 individuals with the study website or telephone system; 4.78% (2065/43,234) of which were successfully enrolled and provided study data. Of these 90.4% (1867/2065) were recruited via paid advertising methods, 23.0% (475/2065) of whom were in the first trimester of pregnancy. The overall costs per active recruited participant were lowest for email (€23.24) and website (€24.41) advertisements and highest for leaflet (€83.14) and television (€100.89). Website adverts were substantially superior in their ability to recruit participants during their first trimester of pregnancy (317/668, 47.5%) in comparison with other advertising methods (P<.001). However, we identified international variations in both the cost-effectiveness of the various advertisement methods used and in their ability to recruit participants in early pregnancy.Recruitment of a pregnant cohort using direct-to-participant advertisement methods is feasible, but the total costs incurred are not insubstantial. Future research is needed to identify advertising strategies capable of recruiting large numbers of demographically representative pregnant women, preferentially in early pregnancy

Numerical analysis of quasinormal modes in nearly extremal Schwarzschild-de Sitter spacetimes

We calculate high-order quasinormal modes with large imaginary frequencies for electromagnetic and gravitational perturbations in nearly extremal Schwarzschild-de Sitter spacetimes. Our results show that for low-order quasinormal modes, the analytical approximation formula in the extremal limit derived by Cardoso and Lemos is a quite good approximation for the quasinormal frequencies as long as the model parameter $r_1\kappa_1$ is small enough, where $r_1$ and $\kappa_1$ are the black hole horizon radius and the surface gravity, respectively. For high-order quasinormal modes, to which corresponds quasinormal frequencies with large imaginary parts, on the other hand, this formula becomes inaccurate even for small values of $r_1\kappa_1$. We also find that the real parts of the quasinormal frequencies have oscillating behaviors in the limit of highly damped modes, which are similar to those observed in the case of a Reissner-Nordstr{\" o}m black hole. The amplitude of oscillating ${\rm Re(\omega)}$ as a function of ${\rm Im}(\omega)$ approaches a non-zero constant value for gravitational perturbations and zero for electromagnetic perturbations in the limit of highly damped modes, where $\omega$ denotes the quasinormal frequency. This means that for gravitational perturbations, the real part of quasinormal modes of the nearly extremal Schwarzschild-de Sitter spacetime appears not to approach any constant value in the limit of highly damped modes. On the other hand, for electromagnetic perturbations, the real part of frequency seems to go to zero in the limit.Comment: 9 pages, 7 figures, to appear in Physical Review