12,513 research outputs found
International Lattice Data Grid: Turn on, plug in,and download
In the beginning there was the internet, then came the world wide web, and
now there is the grid. In the future perhaps there will be the cloud. In the
age of persistent, pervasive, and pandemic networks I review how the lattice
QCD community embraced the open source paradigm for both code and data whilst
adopting the emerging grid technologies, and why having your data persistently
accessible via standardized protocols and services might be a good idea.Comment: 8 pages, 1 figur
The employment benefits of organic farming
Organic farming in the UK provides a range of economic and social benefi ts. In particular, it provides 32% more jobs per farm than equivalent non-organic farms. These new findings are based on the fi rst national survey of employment on UK organic farms, carried out by the University of Essex for the Soil Association. Organic farming is helping to reverse the decline in the UK’s agricultural workforce, which has fallen by 80% in the last 50 years. In contrast to the ageing overall farming population, organic farmers are, on average, seven years younger than their non-organic counterparts. Organic farmers are also three times more likely to be engaged in business innovations activities, such as direct marketing and on-farm processing. If all UK farmers adopted organic farming, it would produce an additional 93,000 on-farm jobs. These findings have significant implications for developing countries where a skilled agricultural workforce is vital to safeguard livelihoods and ensure global food security
Phase Diagrams of Quasispecies Theory with Recombination and Horizontal Gene Transfer
We consider how transfer of genetic information between individuals
influences the phase diagram and mean fitness of both the Eigen and the
parallel, or Crow-Kimura, models of evolution. In the absence of genetic
transfer, these physical models of evolution consider the replication and point
mutation of the genomes of independent individuals in a large population. A
phase transition occurs, such that below a critical mutation rate an
identifiable quasispecies forms. We generalize these models of quasispecies
evolution to include horizontal gene transfer. We show how transfer of genetic
information changes the phase diagram and mean fitness and introduces
metastability in quasispecies theory, via an analytic field theoretic mapping.Comment: 5 pages, 1 figure, to appear in Physics Review Letter
Ionospheric and magnetospheric plasmapauses'
During August 1972, Explorer 45 orbiting near the equatorial plane with an apogee of about 5.2 R sub e traversed magnetic field lines in close proximity to those simultaneously traversed by the topside ionospheric satellite ISIS 2 near dusk in the L range 2-5.4. The locations of the Explorer 45 plasmapause crossings during this month were compared to the latitudinal decreases of the H(+) density observed on ISIS 2 near the same magnetic field lines. The equatorially determined plasmapause field lines typically passed through or poleward of the minimum of the ionospheric light ion trough, with coincident satellite passes occurring for which the L separation between the plasmapause and trough field lines was between 1 and 2. Vertical flows of the H(+) ions in the light ion trough as detected by the magnetic ion mass spectrometer on ISIS were directed upward with velocities between 1 and 2 kilometers/sec near dusk on these passes. These velocities decreased to lower values on the low latitude side of the H(+) trough but did not show any noticeable change across the field lines corresponding to the magnetospheric plasmapause
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