15,109 research outputs found
Exploring the challenges of implementing e-health: a protocol for an update of a systematic review of reviews.
There is great potential for e-health to deliver cost-effective, quality healthcare and spending on e-health systems by governments and healthcare systems is increasing worldwide. However, the literature often describes problematic and unsuccessful attempts to implement these new technologies into routine clinical practice. To understand and address the challenges of implementing e-health, a systematic review was conducted in 2009, which identified several conceptual barriers and facilitators to implementation. As technology is rapidly changing and new e-health solutions are constantly evolving to meet the needs of current practice, an update of this review is deemed necessary to understand current challenges to the implementation of e-health. This research aims to identify, summarise and synthesise currently available evidence, by undertaking a systematic review of reviews to explore the barriers and facilitators to implementing e-health across a range of healthcare settings
Mind The Gap
We discuss an optimisation criterion for the exact renormalisation group
based on the inverse effective propagator, which displays a gap. We show that a
simple extremisation of the gap stabilises the flow, leading to better
convergence of approximate solutions towards the physical theory. This improves
the reliability of truncations, most relevant for any high precision
computation. These ideas are closely linked to the removal of a spurious scheme
dependence and a minimum sensitivity condition. The issue of predictive power
and a link to the Polchinski RG are discussed as well. We illustrate our
findings by computing critical exponents for the Ising universality class.Comment: 6 pages, Talk presented at 2nd Conference on Exact Renormalization
Group (ERG2000), Rome, Italy, 18-22 Sep 200
NEOWISE observations of comet C/2013 A1 (Siding Spring) as it approaches Mars
The Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) mission
observed comet C/2013 A1 (Siding Spring) three times at 3.4 {\mu}m and 4.6
{\mu}m as the comet approached Mars in 2014. The comet is an extremely
interesting target since its close approach to Mars in late 2014 will be
observed by various spacecraft in-situ. The observations were taken in 2014
Jan., Jul. and Sep. when the comet was at heliocentric distances of 3.82 AU,
1.88 AU, and 1.48 AU. The level of activity increased significantly between the
Jan. and Jul. visits but then decreased by the time of the observations in
Sep., approximately 4 weeks prior to its close approach to Mars. In this work
we calculate Af\r{ho} values, and CO/CO2 production rates.Comment: 9 pages, 3 figures, accepted by Astrophysical Journal Letter
A comparison of the domestic satellite communications forecast to the year 2000
The methodologies and results of three NASA-sponsored market demand assessment studies are presented and compared. Forecasts of future satellite addressable traffic (both trunking and customer premises services) were developed for the three main service categories of voice, data and video and subcategories thereof for the benchmark years of 1980, 1990 and 2000. The contractor results are presented on a service by service basis in two formats: equivalent 36 MHz transponders and basic transmission units (voice: half-voice circuits, data: megabits per second and video: video channels). It is shown that while considerable differences exist at the service category level, the overall forecasts by the two contractors are quite similar. ITT estimates the total potential satellite market to be 3594 transponders in the year 2000 with data service comprising 54 percent of this total. The WU outlook for the same time period is 2779 transponders with voice services accounting for 66 percent of the total
The impact of air pollutant and methane emission controls on tropospheric ozone and radiative forcing: CTM calculations for the period 1990-2030
To explore the relationship between tropospheric ozone and radiative forcing with changing emissions, we compiled two sets of global scenarios for the emissions of the ozone precursors methane (CH<sub>4</sub>), carbon monoxide (CO), non-methane volatile organic compounds (NMVOC) and nitrogen oxides (NO<sub>x</sub>) up to the year 2030 and implemented them in two global Chemistry Transport Models. The 'Current Legislation' (CLE) scenario reflects the current perspectives of individual countries on future economic development and takes the anticipated effects of presently decided emission control legislation in the individual countries into account. In addition, we developed a 'Maximum technically Feasible Reduction' (MFR) scenario that outlines the scope for emission reductions offered by full implementation of the presently available emission control technologies, while maintaining the projected levels of anthropogenic activities. Whereas the resulting projections of methane emissions lie within the range suggested by other greenhouse gas projections, the recent pollution control legislation of many Asian countries, requiring introduction of catalytic converters for vehicles, leads to significantly lower growth in emissions of the air pollutants NO<sub>x</sub>, NMVOC and CO than was suggested by the widely used and more pessimistic IPCC (Intergovernmental Panel on Climate Change) SRES (Special Report on Emission Scenarios) scenarios (Nakicenovic et al., 2000), which made Business-as-Usual assumptions regarding emission control technology. With the TM3 and STOCHEM models we performed several long-term integrations (1990-2030) to assess global, hemispheric and regional changes in CH<sub>4</sub>, CO, hydroxyl radicals, ozone and the radiative climate forcings resulting from these two emission scenarios. Both models reproduce broadly the observed trends in CO, and CH<sub>4</sub> concentrations from 1990 to 2002. <P style='line-height: 20px;'> For the 'current legislation' case, both models indicate an increase of the annual average ozone levels in the Northern Hemisphere by 5ppbv, and up to 15ppbv over the Indian sub-continent, comparing the 2020s (2020-2030) with the 1990s (1990-2000). The corresponding higher ozone and methane burdens in the atmosphere increase radiative forcing by approximately 0.2 Wm<sup>-2</sup>. Full application of today's emissions control technologies, however, would bring down ozone below the levels experienced in the 1990s and would reduce the radiative forcing of ozone and methane to approximately -0.1 Wm<sup>-2</sup>. This can be compared to the 0.14-0.47 Wm<sup>-2</sup> increase of methane and ozone radiative forcings associated with the SRES scenarios. While methane reductions lead to lower ozone burdens and to less radiative forcing, further reductions of the air pollutants NO<sub>x</sub> and NMVOC result in lower ozone, but at the same time increase the lifetime of methane. Control of methane emissions appears an efficient option to reduce tropospheric ozone as well as radiative forcing
Density distributions of superheavy nuclei
We employed the Skyrme-Hartree-Fock model to investigate the density
distributions and their dependence on nuclear shapes and isospins in the
superheavy mass region. Different Skyrme forces were used for the calculations
with a special comparison to the experimental data in Pb. The
ground-state deformations, nuclear radii, neutron skin thicknesses and
-decay energies were also calculated. Density distributions were
discussed with the calculations of single-particle wavefunctions and shell
fillings. Calculations show that deformations have considerable effects on the
density distributions, with a detailed discussion on the 120 nucleus.
Earlier predictions of remarkably low central density are not supported when
deformation is allowed for.Comment: 7 pages, 10 figure
Crucial Dependence of ``Precarious'' and ``Autonomous'' phi^4s Upon the Normal-ordering Mass
Using the Gaussian wave-functional approach with the normal-ordering
renormalization prescription, we show that for the (3+1)-dimensional massive
lambda phi^4 theory, ``precarious'' and ``autonomous'' phi^4s can exist if and
only if the normal-ordering mass is equal to the classical masses at the
symmetrc and asymmetric vacua, respectively.Comment: 6 pages, no figures, Revtex file, accepted for publication in Mod.
Phys. Lett.
The influence of potassium on core and geodynamo evolution
We model the thermal evolution of the core and mantle using a parametrized convection scheme, and calculate the entropy available to drive the geodynamo as a function of time. The cooling of the core is controlled by the rate at which the mantle can remove heat. Rapid core cooling favours the operation of a geodynamo but creates an inner core that is too large; slower cooling reduces the inner core size but makes a geodynamo less likely to operate. Introducing potassium into the core retards inner core growth and provides an additional source of entropy. For our nominal model parameters, a core containing approximate to 400 ppm potassium satisfies the criteria of present-day inner core size, surface heat flux, mantle temperature and cooling rate, and positive core entropy production.We have identified three possibilities that may allow the criteria to be satisfied without potassium in the core. (1) The core thermal conductivity is less than half the generally accepted value of 50 W m(-1) K-1. (2) The core solidus and adiabat are significantly colder and shallower than results from shock experiments and ab initio simulations indicate. (3) The core heat flux has varied by no more than a factor of 2 over Earth history.
All models we examined with the correct present-day inner core radius have an inner core age of < 1.5 Gyr; prior to this time the geodynamo was sustained by cooling and radioactive heat production within a completely liquid core
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