Graphene-protected copper and silver plasmonics

Plasmonics has established itself as a branch of physics which promises to revolutionize data processing, improve photovoltaics, increase sensitivity of bio-detection. A widespread use of plasmonic devices is notably hindered (in addition to high losses) by the absence of stable and inexpensive metal films suitable for plasmonic applications. This may seem surprising given the number of metal compounds to choose from. Unfortunately, most of them either exhibit a strong damping of surface plasmons or easily oxidize and corrode. To this end, there has been continuous search for alternative plasmonic materials that are, unlike gold, the current metal of choice in plasmonics, compatible with complementary metal oxide semiconductor technology. Here we show that copper and silver protected by graphene are viable candidates. Copper films covered with one to a few graphene layers show excellent plasmonics characteristics surpassing those of gold films. They can be used to fabricate plasmonic devices and survive for at least a year, even in wet and corroding conditions. As a proof of concept, we use the graphene-protected copper to demonstrate dielectric loaded plasmonic waveguides and test sensitivity of surface plasmon resonances. Our results are likely to initiate a wide use of graphene-protected plasmonics.Comment: 22 pages, 5 figure

Crop Updates 2002 - Pulse Research and Industry Development in Western Australia

This session covers seventy one papers from different authors: 1. 2001 PULSE INDUSTRY HIGHLIGHTS CONTRIBUTORS BACKGROUND 2001 REGIONAL ROUNDUP 2. Northern Agricultural Region, M. Harries, Department of Agriculture 3. Central Agricultural Region, R. French and I. Pritchard, Department of Agriculture 4. Great Southern and Lakes, N. Brandon, N. Runciman and S. White, Department of Agriculture 5. Esperance Mallee, M. Seymour, Department of Agriculture PULSE PRODUCTION AGRONOMY AND GENETIC IMPROVEMENT 6. Faba bean, P. White, Department of Agriculture 7. Germplasm evaluation, P. White, M. Seymour and M. Harries, Department of Agriculture 8. Variety evaluation, P. White, M. Harries, N. Brandon and M. Seymour, Department of Agriculture 9. Sowing rate and time of sowing, P. White, N. Brandon, M. Seymour and M. Harries, Department of Agriculture 10.Use of granular inoculum in the Great Southern, N. Brandon1, J. Howieson2 and R. Yates2 1Department of Agriculture, 2Centre for Rhizobium Studies, Murdoch University 11.Tolerance to post emergent herbicides, M. Seymour and M. Harries, Department of Agriculture 12.Herbicide tolerance of new varieties, H. Dhammu and T. Piper, Department of Agriculture Desi chickpea 13. Breeding highlights, T. Khan, Department of Agriculture 14. Variety evaluation, T. Khan and K. Regan, Department of Agriculture 15. Effect of genotype and environment on seed quality, N. Suizu1 and D. Diepeveen2 1School of Public Health, Curtin University of Technology 2Department of Agriculture 16. Seed discolouration, C. Veitch and P. White, Department of Agriculture 17. Foliar application on N increases seed yield and seed protein under terminal drought, J. Palta1,2, A. Nandwal3 and N. Turner1,2 , 1CSIRO Plant Industry, 2CLIMA, the University of Western Australia, 3Department of Botany, Haryana Agric University, Hisar, India 18. Tolerance to chilling at flowering, H. Clarke, CLIMA, The University of Western Australia 19. Molecular studies of ascochyta blight disease in chickpea, G. Dwyer1, H. Loo1, T. Khan2, K. Siddique3, M. Bellgard1 and M. Jones1 ,1WA State Agricultural Biotechnology Centre and Centre for Bioinformatics and Biological Computing, Murdoch University, 2Department of Agriculture, 3CLIMA, The University of Western Australia 20. Effect of row spacing and sowing rate on seed yield, G. Riethmuller and B. MacLeod, Department of Agriculture 21. Herbicide tolerance on marginal soil types, H. Dhammu and T. Piper, Department of Agriculture 22. Kabuli chickpea, K. Regan, Department of Agriculture 23. Variety and germplasm evaluation, T. Khan and K. Regan, Department of Agriculture 24. Premium quality kabuli chickpea development in the ORIA, K. Siddique1, K. Regan2, R. Shackles2 and P. Smith2 , 1 CLIMA, The University of Western Australia, 2Department of Agriculture 25. Evaluation of ascochylta resistant germplasm from Syria and Turkey, K. Siddique1, C. Francis1 and K. Regan2, 1CLIMA, University of Western Australia 2Department of Agriculture Field pea 26. Breeding highlights, T. Khan Department of Agriculture 27. Variety evaluation, T. Khan Department of Agriculture 28. Comparing the phosphorus requirement of field pea and wheat, M. Bolland and P. White, Department of Agriculture 29. Tolerance of field pea to post emergent herbicides, M. Seymour and N. Brandon, Department of Agriculture 30. Response of new varieties to herbicides, H. Dhammu and T. Piper, Department of Agriculture 31. Lentil, K. Regan, Department of Agriculture 32. Variety evaluation, K. Regan, N. Brandon, M. Harries and M. Seymour, Department of Agriculture 33. Interstate evaluation of advanced breeding lines developed in WA, K. Regan1, K. Siddique2 and M. Materne3, 1Department of Agriculture, 2CLIMA, University of Western Australia, 3Victorian Institute for Dryland Agriculture, Agriculture Victoria 34. Evaluation of germplasm from overseas and local projects, K. Regan1, J. Clements2, K.H.M. Siddique2 and C. Francis21Department of Agriculture, 2CLIMA, University of Western Australia 35. Evaluation of breeding lines developed in WA, K. Regan1, J. Clements2, K.H.M. Siddique2 and C. Francis21Department of Agriculture, 2CLIMA, University of Western Australia 36. Productivity and yield stability in Australia and Nepal, C. Hanbury, K. Siddique and C. Francis, CLIMA, the University of Western Australia Vetch 37. Germplasm evaluation, M. Seymour1, R. Matic2 and M. Tate3, 1Department of Agriculture, 2South Australian Research and Development Institute, 3University of Adelaide, Waite Campus 38. Tolerance of common vetch to post emergent herbicides, M. Seymour and N. Brandon, Department of Agriculture Narbon bean 39. Removing narbon bean from wheat, M. Seymour, Department of Agriculture 40. Tolerance to low rates of Roundup and Sprayseed, M. Seymour, Department of Agriculture 41. Lathyrus development, C. Hanbury, CLIMA, the University of Western Australia 42. Poultry feeding trials, C. Hanbury1 and B. Hughes2 ,1CLIMA, the University of Western Australia,2Pig and Poultry Production Institute, South Australia Pulse Species 43. Species time of sowing, B. French, Department of Agriculture 44. High value pulses in the Great Southern, N. Brandon and N. Runciman, Department of Agriculture 45. Time of Harvest for improved seed yields of pulses, G. Riethmuller and B. French, Department of Agriculture 46. Phosphate acquisition efficiency of pulse crops, P. Rees, Plant Biology, Faculty of Natural and Agricultural Sciences UWA DEMONSTRATION OF PULSES IN THE FARMING SYSTEM 47. Howzat desi chickpea in the northern region, M. Harries, Department of Agriculture 48. Field pea harvest losses in the Great Southern and Esperance region, N. Brandon and M. Seymour, Department of Agriculture 49. Timing of crop topping in field pea, N. Brandon and G. Riethmuller, Department of Agriculture DISEASE AND PEST MANAGEMENT 50. Ascochyta blight of chickpea, B. MacLeod, M. Harries and N. Brandon, Department of Agriculture 51. Evaluation of Australian management packages, 52. Screening foliar fungicides 53. Row spacing and row spraying 54. Ascochyta management package for 2002, B. MacLeod, Department of Agriculture 55. Epidemiology of aschochyta and botrytis disease of pulses, J. Galloway and B. MacLeod, Department of Agriculture 56. Ascochyta blight of chickpea 57. Black spot of field pea 58. Ascochyta blight of faba bean 59. Ascochyta blight of lentil 60. Botrytis grey mould of chickpea 61. Black spot spread: Disease models are based in reality, J. Galloway, Department of Agriculture 62. Black spot spread: Scaling-up field data to simulate ‘Bakers farm’, M. Salam, J. Galloway, A. Diggle and B. MacLeod, Department of Agriculture 63. Pulse disease diagnostics, N. Burges and D. Wright, Department of Agriculture Viruses in pulses 64. Incidence of virus diseases in chickpea, J. Hawkes1, D. Thackray1 and R. Jones1,2, 1CLIMA, The University of Western Australia 2Department of Agriculture Insect pests 65. Risk assessment of aphid feeding damage on pulses, O. Edwards, J. Ridsdill-Smith, and R. Horbury, CSIRO Entomology 66. Optimum spray timing to control aphid feeding damage of faba bean, F. Berlandier, Department of Agriculture 67. Incorporation of pea weevil resistance into a field pea variety, O. Byrne1 and D. Hardie2, 1CLIMA, The University of Western Australia, 2Department of Agriculture 68. Screening wild chickpea species for resistance to Helicoverpa, T. Ridsdill-Smith1 and H. Sharma2,1CSIRO, Entomology, 2ICRISAT, Hyderabad 69. Field strategies to manage the evolution of pea weevil resistance in transgenic field pea, M. de Sousa Majer1, R. Roush2, D. Hardie3, R. Morton4 and T. Higgins4, 1Curtin University of Technology, 2Waite Campus, University of Adelaide, 3Department of Agriculture, 4CSIRO Plant Industry, Canberra 70. ACKNOWLEDGMENTS 71. Appendix 1: Summary of previous result

A Flight Research Overview of WSPR, a Pilot Project for Sonic Boom Community Response

In support of NASAs ongoing effort to bring supersonic commercial travel to the public, NASA Dryden Flight Research Center and NASA Langley Research Center, in cooperation with other industry organizations, conducted a flight research experiment to identify the methods, tools, and best practices for a large-scale quiet (or low) sonic boom community human response test. The name of the effort was Waveforms and Sonic boom Perception and Response. Such tests will go towards building a dataset that governing agencies like the Federal Aviation Administration and International Civil Aviation Organization will use to establish regulations for acceptable sound levels of overland sonic booms. Until WSPR, there had never been an effort that studied the response of people in their own homes and performing daily activities to non-traditional, low sonic booms.WSPR was a NASA collaborative effort with several industry partners, in response to a NASA Aeronautics Research Mission Directorate Research Opportunities in Aeronautics. The primary contractor was Wyle. Other partners included Gulfstream Aerospace Corporation, Pennsylvania State University, Tetra Tech, and Fidell Associates, Inc.A major objective of the effort included exposing a community with the sonic boom magnitudes and occurrences expected in high-air traffic regions with a network of supersonic commercial aircraft in place. Low-level sonic booms designed to simulate those produced by the next generation of commercial supersonic aircraft were generated over a small residential community. The sonic boom footprint was recorded with an autonomous wireless microphone array that spanned the entire community. Human response data was collected using multiple survey methods. The research focused on essential elements of community response testing including subject recruitment, survey methods, instrumentation systems, flight planning and operations, and data analysis methods.This paper focuses on NASAs role in the efforts logistics and operations including human response subject recruitment, the operational processes involved in implementing the surveys throughout the community, instrumentation systems, logistics, flight planning, and flight operations. Findings discussed in this paper include critical lessons learned in all of those areas. The paper also discusses flight operations results. Analysis of the accuracy and repeatability of planning and executing the unique aircraft maneuver used to generate low sonic booms concluded that the sonic booms had overpressures within 0.15 pounds-per-square-feet of the planned values for 76 of t he attempts. Similarly, 90 of the attempts to generate low sonic booms within the community were successful

Evidence in Sheep for Pre-Natal Transmission of Scrapie to Lambs from Infected Mothers

Natural scrapie transmission from infected ewes to their lambs is thought to occur by the oral route around the time of birth. However the hypothesis that scrapie transmission can also occur before birth (in utero) is not currently favoured by most researchers. As scrapie is an opportunistic infection with multiple infection routes likely to be functional in sheep, definitive evidence for or against transmission from ewe to her developing fetus has been difficult to achieve. In addition the very early literature on maternal transmission of scrapie in sheep was compromised by lack of knowledge of the role of the PRNP (prion protein) gene in control of susceptibility to scrapie. In this study we experimentally infected pregnant ewes of known PRNP genotype with a distinctive scrapie strain (SSBP/1) and looked for evidence of transmission of SSBP/1 to the offspring. The sheep were from the NPU Cheviot flock, which has endemic natural scrapie from which SSBP/1 can be differentiated on the basis of histology, genetics of disease incidence and strain typing bioassay in mice. We used embryo transfer techniques to allow sheep fetuses of scrapie-susceptible PRNP genotypes to develop in a range of scrapie-resistant and susceptible recipient mothers and challenged the recipients with SSBP/1. Scrapie clinical disease, caused by both natural scrapie and SSBP/1, occurred in the progeny but evidence (including mouse strain typing) of SSBP/1 infection was found only in lambs born to fully susceptible recipient mothers. Progeny were not protected from transmission of natural scrapie or SSBP/1 by washing of embryos to International Embryo Transfer Society standards or by caesarean derivation and complete separation from their birth mothers. Our results strongly suggest that pre-natal (in utero) transmission of scrapie may have occurred in these sheep

Investigating the conformational stability of prion strains through a kinetic replication model

Prion proteins are known to misfold into a range of different aggregated forms, showing different phenotypic and pathological states. Understanding strain specificities is an important problem in the field of prion disease. Little is known about which PrP(Sc) structural properties and molecular mechanisms determine prion replication, disease progression and strain phenotype. The aim of this work is to investigate, through a mathematical model, how the structural stability of different aggregated forms can influence the kinetics of prion replication. The model-based results suggest that prion strains with different conformational stability undergoing in vivo replication are characterizable in primis by means of different rates of breakage. A further role seems to be played by the aggregation rate (i.e. the rate at which a prion fibril grows). The kinetic variability introduced in the model by these two parameters allows us to reproduce the different characteristic features of the various strains (e.g., fibrils' mean length) and is coherent with all experimental observations concerning strain-specific behavior

Disruption of visual short-term memory by changing-state auditory stimuli: The role of segmentation

Typically, serial recall performance can be disrupted by the presence of an irrelevant stream of background auditory stimulation, but only if the background stream changes over time (the auditory changing-state effect). It was hypothesized that segmentation of the auditory stream is necessary for changing state to be signified. In Experiment 1, continuous random pitch glides failed to disrupt serial recall, but glides interrupted regularly by silence brought about the usual auditory changing-state effect. In Experiment 2, a physically continuous stream of synthesized vowel sounds was found to have disruptive effects. In Experiment 3, the technique of auditory induction showed that preattentive organization rather than critical features of the sound could account for the disruption by glides. With pitch glides, silence plays a preeminent role in the temporal segmentation of the sound stream, but speech contains corr-elated-time-varying changes in frequency and amplitude that make silent intervals superfluous

A New Method for the Characterization of Strain-Specific Conformational Stability of Protease-Sensitive and Protease-Resistant PrPSc

Although proteinacious in nature, prions exist as strains with specific self-perpetuating biological properties. Prion strains are thought to be associated with different conformers of PrPSc, a disease-associated isoform of the host-encoded cellular protein (PrPC). Molecular strain typing approaches have been developed which rely on the characterization of protease-resistant PrPSc. However, PrPSc is composed not only of protease-resistant but also of protease-sensitive isoforms. The aim of this work was to develop a protocol for the molecular characterization of both, protease-resistant and protease-sensitive PrPSc aggregates. We first set up experimental conditions which allowed the most advantageous separation of PrPC and PrPSc by means of differential centrifugation. The conformational solubility and stability assay (CSSA) was then developed by measuring PrPSc solubility as a function of increased exposure to GdnHCl. Brain homogenates from voles infected with human and sheep prion isolates were analysed by CSSA and showed strain-specific conformational stabilities, with mean [GdnHCl]1/2 values ranging from 1.6 M for MM2 sCJD to 2.1 for scrapie and to 2.8 M for MM1/MV1 sCJD and E200K gCJD. Interestingly, the rank order of [GdnHCl]1/2 values observed in the human and sheep isolates used as inocula closely matched those found following transmission in voles, being MM1 sCJD the most resistant (3.3 M), followed by sheep scrapie (2.2 M) and by MM2 sCJD (1.6 M). In order to test the ability of CSSA to characterise protease-sensitive PrPSc, we analysed sheep isolates of Nor98 and compared them to classical scrapie isolates. In Nor98, insoluble PrPSc aggregates were mainly protease-sensitive and showed a conformational stability much lower than in classical scrapie. Our results show that CSSA is able to reveal strain-specified PrPSc conformational stabilities of protease-resistant and protease-sensitive PrPSc and that it is a valuable tool for strain typing in natural hosts, such as humans and sheep

The Mechanism of Formation of N-Formylkynurenine by Heme Dioxygenases

[Image: see text] Heme dioxygenases catalyze the oxidation of l-tryptophan to N-formylkynurenine (NFK), the first and rate-limiting step in tryptophan catabolism. Although recent progress has been made on early stages in the mechanism, there is currently no experimental data on the mechanism of product (NFK) formation. In this work, we have used mass spectrometry to examine product formation in a number of dioxygenases. In addition to NFK formation (m/z = 237), the data identify a species (m/z = 221) that is consistent with insertion of a single atom of oxygen into the substrate during O(2)-driven turnover. The fragmentation pattern for this m/z = 221 species is consistent with a cyclic amino acetal structure; independent chemical synthesis of the 3a-hydroxypyrroloindole-2-carboxylic acid compound is in agreement with this assignment. Labeling experiments with (18)O(2) confirm the origin of the oxygen atom as arising from O(2)-dependent turnover. These data suggest that the dioxygenases use a ring-opening mechanism during NFK formation, rather than Criegee or dioxetane mechanisms as previously proposed