High-pressure x-ray diffraction study of bulk and nanocrystalline PbMoO4

We studied the effects of high-pressure on the crystalline structure of bulk and nanocrystalline scheelite-type PbMoO4. We found that in both cases the compressibility of the materials is highly non-isotropic, being the c-axis the most compressible one. We also observed that the volume compressibility of nanocrystals becomes higher that the bulk one at 5 GPa. In addition, at 10.7(8) GPa we observed the onset of an structural phase transition in bulk PbMoO4. The high-pressure phase has a monoclinic structure similar to M-fergusonite. The transition is reversible and not volume change is detected between the low- and high-pressure phases. No additional structural changes or evidence of decomposition are found up to 21.1 GPa. In contrast nanocrystalline PbMoO4 remains in the scheelite structure at least up to 16.1 GPa. Finally, the equation of state for bulk and nanocrystalline PbMoO4 are also determined.Comment: 18 pages, 4 figure

Evaluation of a rehabilitation support service after acute stroke: Feasibility and patient/carer benefit

Background: Stroke survivors returning home after discharge from hospital and their carers require support to meet their rehabilitation needs (independence in Activities of Daily Living, exercise, psychosocial support). Voluntary or charitable care providers may be able to address some of these needs. Objective: To explore the feasibility of delivering and evaluating enhanced support to stroke survivors and their carers, with a Rehabilitation Support Worker (RSW). Methods: 16 consecutive stroke survivors and their carers were included. All participants received usual hospital care. Seven of these patients and their carers were also allocated an RSW from a charitable care provider. The RSW accompanied therapy training sessions with the patient, carer and therapist in hospital. On discharge, the RSW visited the patient and carer at home over the initial 6 week post-discharge period to support them in practising rehabilitation skills. Patient function (Barthel Index) and patient/carer confidence were independently assessed at discharge (Week 0). The above assessments and patient/carer mood (GHQ-12) and Carer Giver Strain were also assessed at Weeks 1, 6 and 12. RSWs were interviewed for their views about the service. Results: Participants’ functional ability at Week 1 post-discharge was significantly higher in the RSW group. At 6 and 12 weeks post-discharge, functional ability was not significantly different between groups. Carers in the intervention group were less confident at all time points, however, this was not significant. There was no significant effect on carer strain or well-being. Interviews with RSWs highlighted areas of their training that could be enhanced and the need for greater clarity as to their role. Conclusions: The results showed that a definitive trial of rehabilitation support is feasible. A number of obstacles however would need to be overcome including: difficulty in identifying suitable patients, clarity of the RSW role, and appropriate training content

Effect of high pressure on multiferroic BiFeO3

We report experimental evidence for pressure instabilities in the model multiferroic BiFeO3 and namely reveal two structural phase transitions around 3 GPa and 10 GPa by using diffraction and far-infrared spectroscopy at a synchrotron source. The intermediate phase from 3 to 9 GPa crystallizes in a monoclinic space group, with octahedra tilts and small cation displacements. When the pressure is further increased the cation displacements (and thus the polar character) of BiFeO3 is suppressed above 10 GPa. The above 10 GPa observed non-polar orthorhombic Pnma structure is in agreement with recent theoretical ab-initio prediction, while the intermediate monoclinic phase was not predicted theoretically.Comment: new version, accepted for publication in Phys. Rev.

Temperature dependency of metabolic rates in the upper ocean: A positive feedback to global climate change?

The temperature of seawater can affect marine plankton in various ways, including by affecting rates of metabolic processes. This can change the way carbon and nutrients are fixed and recycled and hence the chemical and biological profile of the water column. A variety of feedbacks on global climate are possible, especially by altering patterns of uptake and return of carbon dioxide to the atmosphere. Here we summarize and synthesize recent studies in the field of ecology, oceanography and ocean carbon cycling pertaining to possible feedbacks involving metabolic processes. By altering the rates of cellular growth and respiration, temperature-dependency may affect nutrient uptake and food demand in plankton and ultimately the equilibrium of pelagic food webs, with cascade effects on the flux of organic carbon between the upper and inner ocean (the “biological carbon pump”) and the global carbon cycle. Insights from modern ecology can be applied to investigate how temperature-dependent changes in ocean biogeochemical cycling over thousands to millions of years may have shaped the long-term evolution of Earth's climate and life. Investigating temperature-dependency over geological time scales, including through globally warm and cold climate states, can help to identify processes that are relevant for a variety of future scenarios

From stars to patients: Lessons from space science and astrophysics for health care informatics

Big Data are revolutionizing nearly every aspect of the modern society. One area where this can have a profound positive societal impact is the field of Health Care Informatics (HCI), which faces many challenges. The key idea behind this study is: can we use some of the experience and technical and methodological solutions from the fields that have successfully adapted to the Big Data era, namely astronomy and space science, to help accelerate the progress of HCI? We illustrate this with examples from the Virtual Observatory framework, and the NCI EDRN project. An effective sharing and reuse of tools, methods, and experiences from different fields can save a lot of effort, time, and expense. HCI can thus benefit from the proven solutions to big data challenges from other domains