2,671 research outputs found
The JEREMI-project on thermocapillary convection in liquid bridges. Part A : Overview of particle accumulation structures
The rapid accumulation of particles suspended in a thermocapillary liquid bridge is planned to be investigated during the JEREMI experiment on the International Space Station scheduled for 2016. An overview is given of the current status of experimental and numerical investigations of this phenomenon
"Cold Melting" of Invar Alloys
An anomalously strong volume magnetostriction in Invars may lead to a
situation when at low temperatures the dislocation free energy becomes negative
and a multiple generation of dislocations becomes possible. This generation
induces a first order phase transition from the FCC crystalline to an amorphous
state, and may be called "cold melting". The possibility of the cold melting in
Invars is connected with the fact that the exchange energy contribution into
the dislocation self energy in Invars is strongly enhanced, as compared to
conventional ferromagnetics, due to anomalously strong volume magnetostriction.
The possible candidate, where this effect can be observed, is a FePt disordered
Invar alloy in which the volume magnetostriction is especially large
The JEREMI-project on thermocapillary convection in liquid bridges. Part B : Overview on impact of co-axial gas flow
Pure surface-tension-driven flow is a unique type of flow that can be controlled through external manipulation of thermal and/or mechanical boundary conditions at the free liquid surface where the entire driving force for the convection is generated. This unique feature has been exploited in recent studies for the active control of the flow instability. The use of forced coaxial gas streams has been proposed as a way to stabilize the Marangoni convection in liquid bridges in the planned space experiment JEREMI (Japanese and European Research Experiment on Marangoni Instabilities). It is aimed at understanding the mechanism of the instability and the role of the surface heat transfer and surface shear stresses. This overview presents corresponding preparatory experimental and numerical studies
Atomic structure and vibrational properties of icosahedral BC boron carbide
The atomic structure of icosahedral BC boron carbide is determined by
comparing existing infra-red absorption and Raman diffusion measurements with
the predictions of accurate {\it ab initio} lattice-dynamical calculations
performed for different structural models. This allows us to unambiguously
determine the location of the carbon atom within the boron icosahedron, a task
presently beyond X-ray and neutron diffraction ability. By examining the inter-
and intra-icosahedral contributions to the stiffness we show that, contrary to
recent conjectures, intra-icosahedral bonds are harder.Comment: 9 pages including 3 figures, accepted in Physical Review Letter
Impact of Beta-Amyloid-Specific Florbetaben PET Imaging on Confidence in Early Diagnosis of Alzheimer’s Disease
BACKGROUND: Early diagnosis of Alzheimer's disease (AD) may be corroborated by imaging of beta-amyloid plaques using positron emission tomography (PET). Here, we performed an add-on questionnaire study to evaluate the relevance of florbetaben imaging (BAY 949172) in diagnosis and consecutive management of probable AD patients.
METHODS: AD patients with a clinical diagnosis in accordance with the NINCDS-ADRDA criteria or controls were imaged using florbetaben. Referring physicians were asked on a voluntary basis about their confidence in initial diagnosis, significance of PET imaging results, and their anticipated consequences for future patient care.
RESULTS: 121 questionnaires for probable AD patients and 80 questionnaires for controls were evaluated. In 18% of patients who had initially received the diagnosis of probable AD, PET scans were rated negative, whereas in controls 18% of scans were positive. An increase in confidence in the initial diagnosis was frequently reported (80%). Imaging results had a significant impact on the intended patient care, as judged by the referring physicians; this was most prominent in those patients with a contradicting scan and/or a low confidence in the initial diagnosis.
CONCLUSION: Florbetaben amyloid imaging increases the overall confidence in diagnosis of AD and may frequently influence clinical decisions and patient management
Ecological traits affect the sensitivity of bees to land-use pressures in European agricultural landscapes
1. Bees are a functionally important and economically valuable group, but are threatened byland-use conversion and intensification. Such pressures are not expected to affect all species identically; rather, they are likely to be mediated by the species’ ecological traits. 2. Understanding which types of species are most vulnerable under which land uses is an important step towards effective conservation planning.3. We collated occurrence and abundance data for 257 bee species at 1584 European sites from surveys reported in 30 published papers (70 056 records) and combined them with species-level ecological trait data. We used mixed-effects models to assess the importance of land use (land-use class, agricultural use-intensity and a remotely-sensed measure of vegetation),traits and trait 9 land-use interactions, in explaining species occurrence and abundance.4. Species’ sensitivity to land use was most strongly influenced by flight season duration and foraging range, but also by niche breadth, reproductive strategy and phenology, with effects that differed among cropland, pastoral and urban habitats.5. Synthesis and applications. Rather than targeting particular species or settings, conservation action s may be more effective if focused on mitigating situations where species’ traits strongly and negatively interact with land-use pressures. We find evidence that low-intensity agriculture can maintain relatively diverse bee communities; in more intensive settings, added floral resources may be beneficial, but will require careful placement with respect to foraging ranges of smaller bee species. Protection of semi-natural habitats is essential, however; in particular, conversion to urban environments could have severe effects on bee diversity and pollination services. Our results highlight the importance of exploring how ecological traits mediate species responses to human impacts, but further research is needed to enhance the predictive ability of such analyses
Medicine and management in European hospitals : a comparative overview
Background: Since the early 1980s all European countries have given priority to reforming the management of
health services. A distinctive feature of these reforms has also been the drive to co-opt professionals themselves
into the management of services, taking on full time or part time (hybrid) management or leadership roles.
However, although these trends are well documented in the literature, our understanding of the nature and impact
of reforms and how they are re-shaping the relationship between medicine and management remains limited.
Most studies have tended to be nationally specific, located within a single discipline and focused primarily on
describing new management practices. This article serves as an Introduction to a special issue of BMC Health
Services Research which seeks to address these concerns. It builds on the work of a European Union funded COST
Action (ISO903) which ran between 2009 and 2013, focusing specifically on the changing relationship between
medicine and management in a European context.
Main text: Prior to describing the contributions to the special issue, this Introduction sets the scene by exploring
four main questions which have characterised much of the recent literature on medicine and management. First is
the question of what we understand by the changing relationship between medicine and management and in
particular which this means for the emergence of so called ‘hybrid’ clinical leader roles? A second question
concerns the forces that have driven change, in particular those relating to the wider project of management
reforms. Third, we raise questions of how medical professionals have responded to these changes and what factors
have shaped their responses. Lastly we consider what some of the outcomes of greater medical involvement in
management and leadership might be, both in terms of intended and unintended outcomes.
Conclusions: The paper concludes by summarising the contributions to the special issue and highlighting the
need to extend research in this area by focusing more on comparative dimensions of change. It is argued that
future research would also benefit theoretically by drawing together insights from health policy and management
literatures.
Keywords: Medicine, Management, Leadership, Public hospitals, Comparative research, Hybrid roles, Performanc
Facilitating the registration of biocontrol organisms, plant extracts and semiochemicals in Europe
The legal regulation of plant protection products (Dir. 91/414/ EEC) is a bottleneck in the market introduction of new microbial biocontrol agents, plant extracts and pheromones. In contrast, invertebrate biocontrol agents (“beneficials”) are not registered at EU level.
The EU-funded project REBECA suggested improvements to accelerate the regulation process and make it more cost-effective, without compromises to the level of safety. Representatives of all stakeholder groups participated in the REBECA workshops. The EU Commission and Member States are encouraged to improve the registration of biocontrol organisms, plant extracts and semiochemicals at EU and/or national level.
The full proposals can be found at www.rebeca-net.de
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