The Nuts and Bolts of Einstein-Maxwell Solutions

We find new non-supersymmetric solutions of five-dimensional ungauged supergravity coupled to two vector multiplets. The solutions are regular, horizonless and have the same asymptotic charges as non-extremal charged black holes. An essential ingredient in our construction is a four-dimensional Euclidean base which is a solution to Einstein-Maxwell equations. We construct stationary solutions based on the Euclidean dyonic Reissner-Nordstrom black hole as well as a six-parameter family with a dyonic Kerr-Newman-NUT base. These solutions can be viewed as compactifications of eleven-dimensional supergravity on a six-torus and we discuss their brane interpretation.Comment: 29 pages, 3 figure

The Confrontation between General Relativity and Experiment

The status of experimental tests of general relativity and of theoretical frameworks for analysing them is reviewed. Einstein's equivalence principle (EEP) is well supported by experiments such as the Eotvos experiment, tests of special relativity, and the gravitational redshift experiment. Future tests of EEP and of the inverse square law are searching for new interactions arising from unification or quantum gravity. Tests of general relativity at the post-Newtonian level have reached high precision, including the light deflection, the Shapiro time delay, the perihelion advance of Mercury, and the Nordtvedt effect in lunar motion. Gravitational-wave damping has been detected in an amount that agrees with general relativity to better than half a percent using the Hulse-Taylor binary pulsar, and other binary pulsar systems have yielded other tests, especially of strong-field effects. When direct observation of gravitational radiation from astrophysical sources begins, new tests of general relativity will be possible.Comment: 89 pages, 8 figures; an update of the Living Review article originally published in 2001; final published version incorporating referees' suggestion

Delivering exceptionally safe transitions of care to older people : a qualitative study of multidisciplinary staff perspectives

Background Transitions of care are often risky, particularly for older people, and shorter hospital stays mean that patients can go home with ongoing care needs. Most previous research has focused on fundamental system flaws, however, care generally goes right far more often than it goes wrong. We explored staff perceptions of how high performing general practice and hospital specialty teams deliver safe transitional care to older people as they transition from hospital to home. Methods We conducted a qualitative study in six general practices and four hospital specialties that demonstrated exceptionally low or reducing readmission rates over time. Data were also collected across four community teams that worked into or with these high-performing teams. In total, 157 multidisciplinary staff participated in semi-structured focus groups or interviews and 9 meetings relating to discharge were observed. A pen portrait approach was used to explore how teams across a variety of different contexts support successful transitions and overcome challenges faced in their daily roles. Results Across healthcare contexts, staff perceived three key themes to facilitate safe transitions of care: knowing the patient, knowing each other, and bridging gaps in the system. Transitions appeared to be safest when all three themes were in place. However, staff faced various challenges in doing these three things particularly when crossing boundaries between settings. Due to pressures and constraints, staff generally felt they were only able to attempt to overcome these challenges when delivering care to patients with particularly complex transitional care needs. Conclusions It is hypothesised that exceptionally safe transitions of care may be delivered to patients who have particularly complex health and/or social care needs. In these situations, staff attempt to know the patient, they exploit existing relationships across care settings, and act to bridge gaps in the system. Systematically reinforcing such enablers may improve the delivery of safe transitional care to a wider range of patients. Trial registration The study was registered on the UK Clinical Research Network Study Portfolio (references 35272 and 36174)