134 research outputs found

    The influence of composition, annealing treatment, and texture on the fracture toughness of Ti-5Al-2.5Sn plate at cryogenic temperatures

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    The plane strain fracture toughness K sub Ic and conventional tensile properties of two commercially produced one-inch thick Ti-5Al-2.5Sn plates were determined at cryogenic temperatures. One plate was extra-low interstitial (ELI) grade, the other normal interstitial. Portions of each plate were mill annealed at 1088 K (1500 F) followed by either air cooling or furnace cooling. The tensile properties, flow curves, and K sub Ic of these plates were determined at 295 K (room temperature), 77 K (liquid nitrogen temperature), and 20 K (liquid hydrogen temperature)

    Detecting brute-force attacks on cryptocurrency wallets

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    Blockchain is a distributed ledger, which is protected against malicious modifications by means of cryptographic tools, e.g. digital signatures and hash functions. One of the most prominent applications of blockchains is cryptocurrencies, such as Bitcoin. In this work, we consider a particular attack on wallets for collecting assets in a cryptocurrency network based on brute-force search attacks. Using Bitcoin as an example, we demonstrate that if the attack is implemented successfully, a legitimate user is able to prove that fact of this attack with a high probability. We also consider two options for modification of existing cryptocurrency protocols for dealing with this type of attacks. First, we discuss a modification that requires introducing changes in the Bitcoin protocol and allows diminishing the motivation to attack wallets. Second, an alternative option is the construction of special smart-contracts, which reward the users for providing evidence of the brute-force attack. The execution of this smart-contract can work as an automatic alarm that the employed cryptographic mechanisms, and (particularly) hash functions, have an evident vulnerability.Comment: 10 pages, 2 figures; published versio

    On the formation of black holes in non-symmetric gravity

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    It has been recently suggested that the Non-symmetric Gravitational Theory (NGT) is free of black holes. Here, we study the linear version of NGT. We find that even with spherical symmetry the skew part of the metric is generally non-static. In addition, if the skew field is initially regular, it will remain regular everywhere and, in particular, at the horizon. Therefore, in the fully-nonlinear theory, if the initial skew-field is sufficiently small, the formation of a black hole is to be anticipated.Comment: 9 pages, ordinary LaTex

    Preliminary archaeoentomological analyses of permafrost-preserved cultural layers from the pre-contact Yup’ik Eskimo site of Nunalleq, Alaska : implications, potential and methodological considerations

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    Acknowledgements Site excavation and samples collection were conducted by archaeologists from the University of Aberdeen, with the help of archaeologists and student excavators from the University of Aberdeen University of Alaska Fairbanks and Bryn Mawr College, Kuskokwim Campus, College of Rural Alaska and residents of Quinhagak and Mekoryuk. This study is funded through AHRC grant to the project ‘Understanding Cultural Resilience and Climate Change on the Bering Sea through Yup’ik Ecological Knowledge, Lifeways, Learning and Archaeology’ to Rick Knecht, Kate Britton and Charlotta Hillderal (University of Aberdeen; AH/K006029/1). Thanks are due to Qanirtuuq Inc. and Quinhagak, Alaska for sampling permissions and to entomologists working at the CNC in Ottawa for allowing access to reference collections of beetles, lice and fleas. Yves Bousquet, Ales Smetana and Anthony E. Davies are specially acknowledged for their help with the identification of coleopteran specimens. Finally, we would also like to thank Scott Elias for useful comments on the original manuscript.Peer reviewedPublisher PD

    Negative Capability and the Capacity to Think in the Present Moment: Some Implications for Leadership Practice

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    Two themes that are prevalent in the literature on leadership practice are planning for the future and learning from the past. In this ‘Leading Questions’ piece, we raise the question of whether, in addition, attention needs to be given to a third element that is not well represented in the literature: the leader's capacity to think in the present. We suggest that such thinking requires the capacity to see what is actually going on, in contrast with what was planned for, expected or intended – even when what is actually going on is uncertain or even unknown. In keeping with the theme of this special issue we demonstrate that attending to the present moment is a refrain both ancient and modern, to be found in eastern and western religion and philosophy while having a direct impact on practical modern disciplines, such as psychoanalysis. For example, Wilfred Bion's writings on psychoanalytic theory explore the nature of mental and emotional capacities demanded by this focus on the present moment and its relationship to the development of thought. Using an idea employed by Bion in this context, we suggest that an important dimension of leadership practice is negative capability, which comprises patience and the ability to tolerate frustration and anxiety. This capability can help the leader to retain the capacity to think in the present moment, even in the face of uncertainty. In this context, important dimensions of leadership practice include the ability to embody key thoughts on behalf of an organization and the capacity to contain the impact of the new thinking that can arise in the present moment. © 2011, Sage Publications. All rights reserved

    Crop Updates - 2003 Pulses

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    This session covers fifty one papers from different authors 2002 PULSE INDUSTRY HIGHLIGHTS CONTRIBUTORS BACKGROUND 2002 REGIONAL ROUNDUP 1.Northern Agricultural Region, M. Harries, Department of Agriculture 2.Central agricultural Region, R. French and I. Pritchard, Department of Agriculture 3.Great Southern and Lakes, R. Beermier, N. Poulish and S. White, Department of Agriculture 4.Esperance Mallee, M. Seymour, Department of Agriculture PULSE PRODUCTION ECONOMY AND GENETIC IMPROVEMENT 5.Faba Bean, P. White, Department of Agriculture 6.Germplasm evaluation, P. White, T. Pope, M. Harries and M. Seymour, Department of Agriculture 7.Row spacing and sowing rate, M. Seymour, Department of Agriculture 8.Tolerance to post emergent herbicides, M. Seymour, M. Harries, R. Beermier, M. Blyth and L. Young, Department of Agriculture 9.Investigation of environmental staining and storage discolouration, N. Abbas1,2, J. Plummer1, P. White3, D. Harris4 and K. Siddique1,2, 1Plant Biology, The University of Western Australia, 2CLIMA, The University of Western Australia, 3Department of Agriculture, 4Chemistry Centre of Western Australia. Desi chickpea 10.Breeding highlights, T. Khan1,2 and K. Siddique2 1Department of Agriculture, 2CLIMA, The University of Western Australia 11. Variety evaluation, T. Khan and K. Regan, Department of Agriculture 12. Residual effect of chickpea row spacing and sowing rate on wheat yield, G. Riethmuller and B. MacLeod, Department of Agriculture 13. Genotype x environmental interaction studies to help explain adaptation, J. Berger1, N. Turner1,2, K. Siddique1, 1CLIMA, The University of Western Australia, 2CSIRO Plant Industry 14. Genetic characterisation of wild relatives, F. Shan and H. Clarke, CLIMA, The University of Western Australia 15. Tolerance to chilling at flowering, H. Clarke, CLIMA, The University of Western Australia 16. Kabuli chickpea, K. Regan, Department of Agriculture 17. Premium quality varieties for the Ord River Irrigation Area, K. Siddique1, K. Regan2 and P. Smith2 1CLIMA, The University of Western Australia, 2Department of Agriculture 18. Development of aschochyta resistant varieties for Australia, K. Siddique1, K. Regan2 and M. Baker2 1CLIMA, University of Western Australia, 2Department of Agriculture Field pea 19. Breeding highlights, T. Khan and B. French, Department of Agriculture 20. Variety evaluation, T. Khan, Department of Agriculture 21. Specialty types for the high rainfall regions, P. White and T. Khan, Department of Agriculture 22. Are new varieties more sensitive to delayed sowing than Dundale? R. French, M. Seymour and R. Beermier, Department of Agriculture 23. Does the size of sown seed affect seed size and yield at harvest? R. Beermier and N. Poulish, Department of Agriculture 24. Tolerance to post emergent herbicides, H. Dhammu, T. Piper and D. Nicholson, Department of Agriculture 25. Lentil, K. Regan, Department of Agriculture 26. Variety evaluation, K. Regan and M. Harries, Department of Agriculture 27. Interstate evaluation of advanced breeding lines, K. Regan1 and M. Materne2 1Department of Agriculture, 2Victorian Institute for Dryland Agriculture, Agriculture Victoria 28. Timing of harvest for the best seed yield, M. Harries and M. Blyth, Department of Agriculture 29. Tolerance to post emergent herbicides, M. Harries and D. Nicholson, Department of Agriculture, H. Dhammu, T. Piper and L. Young, Department of Agriculture 30. Row spacing and stubble, G. Riethmuller, Department of Agriculture Pulse species 31. High value pulses for the high rainfall areas, N. Poulish1, P. White1,2 and K. Siddique1,2 , 1Department of Agriculture, 2CLIMA, The University of Western Australia 32. Alternative Rhizobium inoculant carrier technologies, J. Howieson and R. Yates, Centre for Rhizobium Studies (CRS), Murdoch University 33. Time of harvest to improve seed yield and quality of pulses, G. Riethmuller and R. French, Department of Agriculture 34. Phosphorus and zinc responses in pulses, S. Loss1, Z. Rengel2, B. Bowden3, M. Bolland3 and K. Siddique4 , 1Wesfarmers CSBP, 2Soil Science and Plant Nutrition, The University of Western Australia, 3Department of Agriculture, 4CLIMA, The University of Western Australia 35. Robust protocols for doubled haploid production in field pea and chickpea, J. Croser and K. Siddique, CLIMA, The University of Western Australia DEMONSTRATION OF PULSES IN THE FARMING SYSTEM 36. Field pea and lentil on clayed sandplain, M. Seymour, Department of Agriculture 37. Field pea variety demonstration, M. Harries and M. Blyth, Department of Agriculture 38. The benefit of field peas compared to lupins, R. Beermier, Department of Agriculture DISEASE AND PEST MANAGEMENT 39. Ascochyta blight of chickpea, B. MacLeod, Department of Agriculture 40. Management of chickpeas with improved ascochyta resistance, B. Macleod, A. Harrod, M. Harries and M. Blyth, Department of Agriculture 41. Chlorothalonil provides the most effective control, B. Macleod, A. Harrod, M. Harries and M. Blyth, Department of Agriculture 42. Importance of early sprays and value of seed dressing (post emergence), B. Macleod and A. Harrod, Department of Agriculture 43. A windborne stage of ascochyta blight in WA, J. Galloway and B. MacLeod, Department of Agriculture Ascochyta disease of pulses 44. Geographic location effects ascochyta spore maturation on pulse stubble, J. Galloway and B. MacLeod, Department of Agriculture Blackspot of field pea 45. Rapid recurrent selection to improve resistance to black spot, C. Beeck1, J. Wroth1, W. Cowling1 and T. Khan2, 1Plant Science, The University of Western Australia, 2Department of Agriculture 46. Survival of blackspot on old field pea stubble, J. Galloway and B. MacLeod, Department of Agriculture 47. Blackspot spores mature earlier in the southern regions, M. Salam, J. Galloway, A. Diggle and B. MacLeod, Department of Agriculture Viruses in pulses 48. Early insecticide application suppresses spread of Beet Western Yellows virus in field pea, R. Jones, B. Coutts and L. Smith, Department of Agriculture, and CLIMA, The University of Western Australia Insect pests and nematodes 49. Incorporation of pea weevil resistance from Pisum fulvum into field pea, O. Byrne1 and D. Hardie2, 1CLIMA, The University of Western Australia 2Department of Agriculture 50. Resistance to Helicoverpa in wild species of chickpea, J. Ridsdill-Smith1, H. Sharma2 and K. Mann1, 1CSIRO Entomology, Western Australia, 2 ICRISAT, Hyderabad, India 51. Relative hosting ability of field pea genotypes to root lesion nematode, S. Kelly, S. Sharma, H. Hunter and V. Vanstone, Department of Agriculture ACKNOWLEDGEMENTS APPENDIX I: Publications by Pulse Productivity Project Staff 2002 APPENDIX II: Summary of previous results APPENDIX III: List of common acronym

    Quantum key distribution based on orthogonal states allows secure quantum bit commitment

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    For more than a decade, it was believed that unconditionally secure quantum bit commitment (QBC) is impossible. But basing on a previously proposed quantum key distribution scheme using orthogonal states, here we build a QBC protocol in which the density matrices of the quantum states encoding the commitment do not satisfy a crucial condition on which the no-go proofs of QBC are based. Thus the no-go proofs could be evaded. Our protocol is fault-tolerant and very feasible with currently available technology. It reopens the venue for other "post-cold-war" multi-party cryptographic protocols, e.g., quantum bit string commitment and quantum strong coin tossing with an arbitrarily small bias. This result also has a strong influence on the Clifton-Bub-Halvorson theorem which suggests that quantum theory could be characterized in terms of information-theoretic constraints.Comment: Published version plus an appendix showing how to defeat the counterfactual attack, more references [76,77,90,118-120] cited, and other minor change

    De novo CCND2 mutations leading to stabilization of cyclin D2 cause megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome

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    Activating mutations in genes encoding phosphatidylinositol 3-kinase (PI3K)-AKT pathway components cause megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome (MPPH, OMIM 603387). Here we report that individuals with MPPH lacking upstream PI3K-AKT pathway mutations carry de novo mutations in CCND2 (encoding cyclin D2) that are clustered around a residue that can be phosphorylated by glycogen synthase kinase 3ÎČ (GSK-3ÎČ). Mutant CCND2 was resistant to proteasomal degradation in vitro compared to wild-type CCND2. The PI3K-AKT pathway modulates GSK-3ÎČ activity, and cells from individuals with PIK3CA, PIK3R2 or AKT3 mutations showed similar CCND2 accumulation. CCND2 was expressed at higher levels in brains of mouse embryos expressing activated AKT3. In utero electroporation of mutant CCND2 into embryonic mouse brains produced more proliferating transfected progenitors and a smaller fraction of progenitors exiting the cell cycle compared to cells electroporated with wild-type CCND2. These observations suggest that cyclin D2 stabilization, caused by CCND2 mutation or PI3K-AKT activation, is a unifying mechanism in PI3K-AKT–related megalencephaly syndromes
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