Velocity tuning of friction with two trapped atoms

Our ability to control friction remains modest, as our understanding of the underlying microscopic processes is incomplete. Atomic force experiments have provided a wealth of results on the dependence of nanofriction on structure velocity and temperature but limitations in the dynamic range, time resolution, and control at the single-atom level have hampered a description from first principles. Here, using an ion-crystal system with single-atom, single-substrate-site spatial and single-slip temporal resolution we measure the friction force over nearly five orders of magnitude in velocity, and contiguously observe four distinct regimes, while controlling temperature and dissipation. We elucidate the interplay between thermal and structural lubricity for two coupled atoms, and provide a simple explanation in terms of the Peierls–Nabarro potential. This extensive control at the atomic scale enables fundamental studies of the interaction of many-atom surfaces, possibly into the quantum regime

The neural basis of video gaming

Video game playing is a frequent recreational activity. Previous studies have reported an involvement of dopamine-related ventral striatum. However, structural brain correlates of video game playing have not been investigated. On magnetic resonance imaging scans of 154 14-year-olds, we computed voxel-based morphometry to explore differences between frequent and infrequent video game players. Moreover, we assessed the Monetary Incentive Delay (MID) task during functional magnetic resonance imaging and the Cambridge Gambling Task (CGT). We found higher left striatal grey matter volume when comparing frequent against infrequent video game players that was negatively correlated with deliberation time in CGT. Within the same region, we found an activity difference in MID task: frequent compared with infrequent video game players showed enhanced activity during feedback of loss compared with no loss. This activity was likewise negatively correlated with deliberation time. The association of video game playing with higher left ventral striatum volume could reflect altered reward processing and represent adaptive neural plasticity

Crop Updates 1999 - Lupins

This article contains twenty three papers 1998 LUPIN HIGHLIGHTS LUPIN ANTHRACNOSE 1. Anthracnose overview, Greg Shea, Geoff Thomas and Mark Sweetingham, Agriculture Western Australia 2. Anthracnose – Critical seed infection levels for resistant and susceptible varieties, Geoff Thomas, Mark Sweetingham, Bill O\u27Neill and Greg Shea, Agriculture Western Australia 3. Fungicide seed treatment for anthracnose and brown spot control in lupin, G. Thomas and M. Sweetingham, Agriculture Western Australia LUPIN BREEDING AND AGRONOMY 4. Anthracnose resistance in lupins – an innovative Australian research effort 1996-1998, Wallace Cowling1\u272, Bevan Buirchell1,2 Mark Sweetinqham1,2, Hua\u27an Yang2, Geoff Thomas 1, David Luckett3, Allan Brown4 and John Hamblin2, 1 Agriculture Western Australia, 2 Centre for Legumes in Mediterranean Agriculture, University of Western Australia, 3 NSW Agriculture, Agricultural Institute, Wagga Wagga, NSW, 4 Consultant, 16 Rochester Way, Dianella, WA 5. Gene transfer to pulses: Challenges through 1989-99. Joanne E. Barton, Centre for Legumes in Mediterranean Agriculture, University of Western Australia 6. Can we select for restricted branching in narrow-leafed lupin (Lupinus angustifolius) Kedar Adhikari1, Nick Galwey1and Miles Dracup2, 1Plant Sciences, Faculty of Agriculture, The University of Western Australia,2 Agriculture Western Australia 7. Getting the beat out of new lupin varieties, Dr Bob French, Grain Legume Agronomist, Agriculture Western Australia 8. Starter nitrogen on lupins, Dr Bob French, Grain Legume Agronomist, Agriculture Western Australia APHIDS AND VIRUS CONTROL 9. Forecasting aphid and virus risk in lupins, Debbie Thackray and Roger Jones, CRC for Legumes in Mediterranean Agriculture and Agriculture Western Australia 10. Screening for resistance to cucumber mosaic virus in lupins, Roger Jones, Brenda Coutts, Narelle Reeve, Wallace Cowling and Bevan Buirchell, Agriculture Western Australia and CRC for Legumes in Mediterranean Agriculture 11. The non-necrotic strain of bean yellow mosaic virus spreads faster than the necrotic strain in lupins, Y. Cheng 1 and R.A.C. Jones 1•2, 1 Cooperative Research Centre for Legumes in Mediterranean Agriculture, 2 Agriculture Western Australia 12. Spraying to control aphid feeding damage increases yields of some lupin varieties and faba bean, Francoise Berlandier and Linnet Cartwright, Entomology, Agriculture Western Australia LUPIN NUTRITION 13. Calculated lime requirements for rotations, James Fisher1, Art Diggle 1•2 and Bill Bowden 1•2, 1 Centre for Legumes in Mediterranean Agriculture, 2 Agriculture Western Australia 14. What does lime do to acidic soils – lupin nutrition, Chris Gazey, Research Officer, Agriculture Western Australia 15. Effect of application method of manganese fertiliser and manganese concentration of seed source on seed yield of lupins grown in the West Midlands, Luigi Moreschi, CSBP Area Manager HERBICIDE TOLERANCE AND WEED CONTROL 16. Herbicide tolerance of lupins, Terry Piper, Weed Science Group, Agriculture Western Australia 17. Weed control in Wodjil yellow lupins, Terry Piper, Weed Science Group, Agriculture Western Australia 18. Herbicide tolerance of new lupin varieties, Peter Newman, Agronomist, Elders Mingenew 19. Control of volunteer canola in lupins, Terry Piper and Dave Nicholson, Weed Science Group, Agriculture Western Australia LUPIN ESTABLISHMENT 20. A new seed pressing system for healthy lupin establishment and productivity, Mohammad Amjad, Glen Riethmuller and Ron Jarvis, Agriculture Western Australia 21. Encouragement for controlled traffic farming in the Northern Wheatbelt, Paul Blackwell, Agriculture Western Australia LUPIN HARVESTING 22. Improved lupin harvesting efficiency with different knife guard extensions, Glen Riethmuller, Agriculture Western Australia LUPIN AND PULSE UTILISATION 23. The value of pulse grains for sheep, C.L. White, CSIRO Division of Animal Productio