1,695 research outputs found
Provision of services for rehabilitation of children and adolescents with congenital cardiac disease: a survey of centres for paediatric cardiology in the United Kingdom
A postal questionnaire survey of the 17 centres for paediatric cardiology in the UK investigated the attitudes of staff towards rehabilitation and the current level of provision. The majority of respondents (82%) believed they should provide rehabilitation for their patients, but only one centre had a programme for rehabilitation. Few respondents (18%) believed they were meeting the needs of their patients' for rehabilitation. Major barriers to providing rehabilitation were funding and the wide geographical catchment areas
Matter-wave grating distinguishing conservative and dissipative interactions
We propose an optical grating for matter waves that separates molecules depending on whether their interaction with the light is conservative or dissipative. Potential applications include fundamental tests of quantum mechanics, measurement of molecular properties and the ability to selectively prepare matter waves with different internal temperatures
Convergence of the Many-Body Expansion of Interaction Potentials: From van der Waals to Covalent and Metallic Systems
The many-body expansion of the interaction potential between atoms and molecules is analyzed in detail for different types of interactions involving up to seven atoms. Elementary clusters of Ar, Na, Si, and, in particular, Au are studied, using first-principles wave-function- and density-functional-based methods to obtain the individual n-body contributions to the interaction energies. With increasing atom number the many-body expansion converges rapidly only for long-range weak interactions. Large oscillatory behavior is observed for other types of interactions. This is consistent with the fact that Au clusters up to a certain size prefer planar structures over the more compact three-dimensional Lennard-Jones-type structures. Several Au model potentials and semi-empirical PM6 theory are investigated for their ability to reproduce the quantum results. We further investigate small water clusters as prototypes of hydrogen-bonded systems. Here, the many-body expansion converges rapidly, reflecting the localized nature of the hydrogen bond and justifying the use of two-body potentials to describe water-water interactions. The question of whether electron correlation contributions can be successfully modeled by a many-body interaction potential is also addressed
Plasmodium falciparum infection does not increase the precocious mortality rate of Anopheles gambiae
The structure and properties of horse muscle acylphosphatase in solution Mobility of antigenic and active site regions
AbstractThe solution structure of acylphosphatase determined by proton nuclear magnetic resonance spectroscopy is described. The results allow us to discuss the fold of the protein (101 amino acids), to correlate the exposure and the mobility of the backbone with the antigenicity, and to locate the active site
In vitro frequency analysis of spleen colony-forming and marrow-repopulating hemopoietic stem cells in the mouse
An assay is described for Day-12 spleen colony-forming cells (CFU-S-12) and hemopoietic stem cells with marrow-repopulating ability (MRA) in the mouse using a miniaturized stroma-dependent bone marrow culture assay in vitro. Bone marrow cells are grown in liquid culture in microtiter wells, and the resulting adherent stromal layers are depleted of all hemopoietic activity by 20 Gy gamma irradiation. Subsequently, single cell suspensions containing stem cells are overlaid in a range of concentrations, and the presence of one or more emerging phase nonrefractive cell clones (cobblestone areas) in a single well scored as positive. The frequencies of cobblestone area-forming cells (CAFC) are then calculated by employing Poisson statistics. It is shown that the CAFC Day-10 and CAFC Day-28 frequencies closely correlate with those of CFU-S-12 and MRA cells, respectively
Evaluation of Resource Management Options for Smallholder Farms Using an Integrated Modelling Approach
Farm-level analysis of trade-offs between soil fertility management alternatives is required to improve understanding of complex biophysical and socio-economic factors influencing decision making in smallholder farming systems and to identify opportunities for improving resource use efficiency. A farm characterization tool (IMPACT) linked to a generic optimization model (Household) was used to evaluate resource use on farms in contrasting wealth categories. The Household model optimized the net cash income for the farms (accounting for all on-farm and off-farm income, costs of production and expenditure for the households). Alternatives for management of nutrient resource were simulated using other models; APSIM for the crop production and RUMINANT for the livestock component. The output from the simulation models was fed into the Household model and evaluated within the biophysical and socioeconomic boundaries of the farms. Analysis of the performance of a poor farmer by IMPACT indicated a yearly net cash balance of US81 per annum and the N balance from 7 kg ha-1 yr-1 to 10 kg ha-1 yr-1 by expanding the area allocated to groundnut from the current 5% to 31%. This would, however, generate a huge demand in labour in the current year (extra 46-man days) and reduce the P balance from 0 to -1 kg ha-1 yr-1. Maize could be managed more efficiently on the poor farm by cultivating a smaller, well-managed area. A wealthy farm household with a maize dominated cropping system had a net cash balance of US290 per annum by optimization of household energy and protein consumption. The net cash balance for the wealthy farm would be further increased to US11 compared with the current crop allocation due to poor groundnut yield. This would also increase labour demand by 155 mandays. Groundnut intensification on the wealthy farm would be more economic and labour effective if a small area was grown with basal fertilizer (7%N, 6%P, 8%K). Despite reducing nutrient balances for the arable plots, feeding groundnut residues to lactating cows increased net cash balance by 12-18% for the current year through increased milk production. The integrated modelling approach was useful for linking biophysical and socio-economic factors influencing decision making on smallholder farms and evaluating trade-offs for resource use in terms of nutrient balances, labour use, food sufficiency and cash balance.Farm Management, Resource /Energy Economics and Policy,
Entangled Light in Moving Frames
We calculate the entanglement between a pair of polarization-entangled photon
beams as a function of the reference frame, in a fully relativistic framework.
We find the transformation law for helicity basis states and show that, while
it is frequency independent, a Lorentz transformation on a momentum-helicity
eigenstate produces a momentum-dependent phase. This phase leads to changes in
the reduced polarization density matrix, such that entanglement is either
decreased or increased, depending on the boost direction, the rapidity, and the
spread of the beam.Comment: 4 pages and 3 figures. Minor corrections, footnote on optimal basis
state
Wireless Telecommunications Issues: Cell Phone TV, Wireless Networks in Disaster Management, Ubiquitous Computing, and Adoption of Future Wireless Applications
This paper is a summary of a 2007 Association for Information Systems Americas Conference on Information Systems (AMCIS) panel discussion regarding current mobile wireless issues and technologies. The invited panelists are four faculty members specializing in information systems from the United States. The covered topics included cell phone TV and misconceptions surrounding it, wireless networks in disaster management, ubiquitous computing including anatomy of a mote and sensors, and the adoption of future wireless applications. First, we present wireless cell phone TV as a functioning multipurpose computer, or a Swiss army knife, of media devices. The misconceptions are stated, influenced by preconceived notions by the media critics as well as users. Next we discuss a range of wireless technologies including wearable computing, ad hoc and mesh wireless networks as a means of providing communications for first respondents during a natural or man-made disaster. Then we examine the anatomy of motes and RFIDs, including sensors, in an era of ubiquitous computing and a world of (inter-)connected objects. Finally, we discuss the socio-cultural constructs impacting users\u27 intentions to adopt future wireless applications
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