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We investigated the impact of discontinuation of contact precautions for methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus infected or colonized patients on central-line associated bloodstream infection rates at an academic children’s hospital. Discontinuation of contact precautions with a bundled horizontal infection prevention platform resulted in no adverse impact on CLABSI rates.
Prisoner's Dilemma (PD) games have become a well-established paradigm for studying the mechanisms by which cooperative behavior may evolve in societies consisting of selfish individuals. Recent research has focused on the effect of spatial and connectivity structure in promoting the emergence of cooperation in scenarios where individuals play games with their neighbors, using simple “memoryless” rules to decide their choice of strategy in repeated games. While heterogeneity and structural features such as clustering have been seen to lead to reasonable levels of cooperation in very restricted settings, no conditions on network structure have been established, which robustly ensure the emergence of cooperation in a manner that is not overly sensitive to parameters such as network size, average degree, or the initial proportion of cooperating individuals. Here, we consider a natural random network model, with parameters that allow us to vary the level of “community” structure in the network, as well as the number of high degree hub nodes. We investigate the effect of varying these structural features and show that, for appropriate choices of these parameters, cooperative behavior does now emerge in a truly robust fashion and to a previously unprecedented degree. The implication is that cooperation (as modelled here by PD games) can become the social norm in societal structures divided into smaller communities, and in which hub nodes provide the majority of inter-community connections.
Beethoven's sketch leaves are so numerous and at times so impenetrable that they are bound to throw up the occasional surprise when studied in detail. Around ten thousand such pages survive; they are generally difficult to decipher, and often more than one work appears on a single page. Nevertheless, few surprises will have been as unexpected as the identification of a fragment of a little-known Bach cantata amongst Beethoven's early sketches.
Beethoven’s Grosse Fuge, published in 1827 after being detached from his string quartet Op. 130, appears to be the first work ever to have been allocated rehearsal letters. These were added by Beethoven’s friend Karl Holz at the request of the composer and his publisher Mathias Artaria. The rehearsal letters can be compared with the work’s structure, which is best perceived as dividing into three main ‘movements’, the third being much the longest. A different approach is necessary for analysing each of the three. In the first, reference to medieval rhythmic modes helps to clarify Beethoven’s procedure. The second is essentially a fugue, albeit unusually homophonic. The third is multi-partite but mainly in
, and includes a 32-bar theme that returns intact – the only substantial exact reprise of material. This movement also include two fugal expositions. Thus there are four full fugal expositions altogether, and each is a double fugue in which the exposition is more or less regular. Holz’s letters match up well but not perfectly with the structure of the work.
Alan Turing's short life ran from 1912 to 1954. The inspiration for this volume lay in the centenary of his birth. But Barry Cooper and I, as editors, wanted the word ‘future’ in our title, as well as a reference to the past. We chose the provocative title The Once and Future Turing, alluding to the legend of King Arthur's tomb. We invited a range of distinguished contributors to give us snapshots of scientific work which rest upon Turing's original discoveries, and share the spirit of his thought, but which also give a glimpse of something lying beyond the present. The result is a volume of 15 papers, whose authors responded to our prompting in utterly different ways.
Turing himself was not reticent about advancing visions of the future. Famously, he did so in his classic 1950 paper ‘Computing machinery and intelligence’. He was not always right. Few people would claim that his 50-year prediction for machine intelligence, cautiously phrased as it was, has been fulfilled. On the other hand, he underestimated the potential for fast, cheap, huge-scale computing. His 1948 picture of the future of computer hardware correctly identified the speed of light as the critical constraint governing computing speed. But his assumption of centimetre-scale electronic components overlooked the enormous potential for miniaturisation. Turing's foresight was more strikingly demonstrated by his 1946 observations about the power of the universal machine and the future of what would now be called the software industry; ‘every known process has got to be translated into instruction table form … ’
In 1946 he could speak with the confidence of being the mastermind of the Anglo-American crypto war – with its own legacy for the future of international relations, which, to say the least, has not yet been evaluated. In 1939 he and Gordon Welchman had pulled off the feat of persuading the British authorities to make a huge investment in the untried technology of the Turing Bombe, on the conviction, correct as it turned out, that its logical brilliance would transform British fortunes. This vision was not his alone. To beat Hitler, Bletchley Park seems to have borrowed from the future, scientifically, organisationally and socially, as if the sixties had arrived before the forties.
The world is open for fresh ideas about fundamentals of mind, matter, information, space and time. Turing made just such a plunge in 1936, undeterred by being young and new to the field. Compared with the carefully delineated and trained trajectory expected of modern research students, his d ébut seems amazing. It was extraordinary even then, being without precursor papers or collaborators. But, of course, the young Turing was not alone: Einstein and Eddington, von Neumann and Russell, had spoken volumes to his receptive mind, and he had worked hard through Cambridge mathematics. He was justifiably proud of his breakthrough as a 24-year-old, and correspondingly interested in spotting new youthful talent. His highly unconventional running with young Garner had a parallel: a wish to hand on scientific inspiration to a young person, perhaps in a way quite outside the standard academic framework. This Alan Turing indeed achieved, to some extent, but maybe he has still more to do.
These essays themselves, with their unusual connections and incomplete conclusions, might stimulate new minds with new thoughts. Miguel Walsh, winner of the 2014 Ramanujan Prize, explains how he learned about outstanding problems in mathematics from the Internet, while otherwise isolated in Argentina. We are reminded of how Srinivasa Ramanujan himself emerged from isolation, in the very India where Alan Turing was conceived, through the old mechanism of print and post offices. In the last century, the universal machine has greatly accelerated and amplified such global interaction. Who knows! The history of science depends on the strangest encounters of human brains. The once and future Turing both take their life from the unpredictable and sometimes highly inconvenient magic of human thought.
Alan Turing (1912–1954) made seminal contributions to mathematical logic, computation, computer science, artificial intelligence, cryptography and theoretical biology. In this volume, outstanding scientific thinkers take a fresh look at the great range of Turing's contributions, on how the subjects have developed since his time, and how they might develop still further. The contributors include Martin Davis, J. M. E. Hyland, Andrew R. Booker, Ueli Maurer, Kanti V. Mardia, S. Barry Cooper, Stephen Wolfram, Christof Teuscher, Douglas Richard Hofstadter, Philip K. Maini, Thomas E. Woolley, Eamonn A. Gaffney, Ruth E. Baker, Richard Gordon, Stuart Kauffman, Scott Aaronson, Solomon Feferman, P. D. Welch and Roger Penrose. These specially commissioned essays will provoke and engross the reader who wishes to understand better the lasting significance of one of the twentieth century's deepest thinkers.