43 research outputs found
Codeword stabilized quantum codes: algorithm and structure
The codeword stabilized ("CWS") quantum codes formalism presents a unifying
approach to both additive and nonadditive quantum error-correcting codes
(arXiv:0708.1021). This formalism reduces the problem of constructing such
quantum codes to finding a binary classical code correcting an error pattern
induced by a graph state. Finding such a classical code can be very difficult.
Here, we consider an algorithm which maps the search for CWS codes to a problem
of identifying maximum cliques in a graph. While solving this problem is in
general very hard, we prove three structure theorems which reduce the search
space, specifying certain admissible and optimal ((n,K,d)) additive codes. In
particular, we find there does not exist any ((7,3,3)) CWS code though the
linear programming bound does not rule it out. The complexity of the CWS search
algorithm is compared with the contrasting method introduced by Aggarwal and
Calderbank (arXiv:cs/0610159).Comment: 11 pages, 1 figur
New approaches to reduced-complexity decoding
We examine new approaches to the problem of decoding general linear codes under the strategies of full or bounded hard decoding and bounded soft decoding. The objective is to derive enhanced new algorithms that take advantage of the major features of existing algorithms to reduce decoding complexity. We derive a wide range of results on the complexity of many existing algorithms. We suggest a new algorithm for cyclic codes, and show how it exploits all the main features of the existing algorithms. Finally, we propose a new approach to the problem of bounded soft decoding, and show that its asymptotic complexity is significantly lower than that of any other currently known general algorithm. In addition, we give a characterization of the weight distribution of the average linear code and thus show that the Gilbert-Varshamov bound is tight for virtually all linear codes over any symbol field.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29034/1/0000066.pd
Digital voices: Posthumanism and the generation of empathy
This chapter investigates digital technologies that variously assist, enable or simulate musical praxis. The first section sets up an opposition between the idea of the digital tool that augments human agency, and the machinic automatism predicated on the idea that reality is fundamentally number (dataism) and ticks along without the need for human consciousness. This gives rise to the idea that mechanical automatism is also intrinsic to human agency, a strand of posthuman thought on which the rest of the chapter turns. Accordingly, the second section shows how posing algorithmic composition as an expression of the posthuman is problematic. The final section focuses on the synthetic voices of digital assistants from online service providers that generate empathy at the price of a surrogate ‘conscience’. Accommodating this within a humanistic model is possible, but a closing case study of Tod Machover’s futurist opera, Death and the Powers (2010), raises the prospect of what might be called a ‘dark ontology’ of the digital
A reference map of the human binary protein interactome.
Global insights into cellular organization and genome function require comprehensive understanding of the interactome networks that mediate genotype-phenotype relationships(1,2). Here we present a human 'all-by-all' reference interactome map of human binary protein interactions, or 'HuRI'. With approximately 53,000 protein-protein interactions, HuRI has approximately four times as many such interactions as there are high-quality curated interactions from small-scale studies. The integration of HuRI with genome(3), transcriptome(4) and proteome(5) data enables cellular function to be studied within most physiological or pathological cellular contexts. We demonstrate the utility of HuRI in identifying the specific subcellular roles of protein-protein interactions. Inferred tissue-specific networks reveal general principles for the formation of cellular context-specific functions and elucidate potential molecular mechanisms that might underlie tissue-specific phenotypes of Mendelian diseases. HuRI is a systematic proteome-wide reference that links genomic variation to phenotypic outcomes
Bulletin of the Aquaculture Association of Canada 2 90 92
The effects of Lepeophtheirus salmonis, on non-specific defence mechanisms in Salmo salar, were determined by experimentally infesting 180 hatchery-reared post-smolts with laboratory-grown infective copepodids at moderate to high infection intensities ranging from 15 to 285 lice per fish. The effects of sea lice-induced stress were investigated by measuring the blood levels of cortisol and glucose as indicators of primary and secondary stress responses, and by changes in macrophage respiratory burst activity and phagocytosis as indicators of tertiary stress responses as well as non-specific defence mechanisms. Fish were sampled prior to sea lice infestation and at days 3, 7, 14, and 21 post-infestation. Blood levels of cortisol and glucose were found to be significantly increased in sea lice-infested fish throughout the experiment while respiratory burst and phagocytic activities were found to be significantly decreased at day 21. The reductions in both respiratory burst and phagocytic activities are presumably the results of chronic stress induced by sea lice. The results from this study also indicate that sea lice have effects on the development of chronic stress and on the suppression of host defence mechanisms when infested with moderate to high parasite intensities.