1,131 research outputs found

    Doubly infinite separation of quantum information and communication

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    We prove the existence of (one-way) communication tasks with a subconstant versus superconstant asymptotic gap, which we call "doubly infinite," between their quantum information and communication complexities. We do so by studying the exclusion game [C. Perry et al., Phys. Rev. Lett. 115, 030504 (2015)] for which there exist instances where the quantum information complexity tends to zero as the size of the input nn increases. By showing that the quantum communication complexity of these games scales at least logarithmically in nn, we obtain our result. We further show that the established lower bounds and gaps still hold even if we allow a small probability of error. However in this case, the nn-qubit quantum message of the zero-error strategy can be compressed polynomially.Comment: 16 pages, 2 figures. v4: minor errors fixed; close to published version; v5: financial support info adde

    Alternative medicine and doping in sports

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    Athletes are high achievers who may seek creative or unconventional methods to improve performance. The literature indicates that athletes are among the heaviest users of complementary and alternative medicine (CAM) and thus may pioneer population trends in CAM use. Unlike non-athletes, athletes may use CAM not just for prevention, treatment or rehabilitation from illness or injuries, but also for performance enhancement. Assuming that athletes’ creative use of anything unconventional is aimed at “legally” improving performance, CAM may be used because it is perceived as more “natural” and erroneously assumed as not potentially doping. This failure to recognise CAMs as pharmacological agents puts athletes at risk of inadvertent doping.The general position of the World Anti-Doping Authority (WADA) is one of strict liability, an application of the legal proposition that ignorance is no excuse and the ultimate responsibility is on the athlete to ensure at all times whatever is swallowed, injected or applied to the athlete is both safe and legal for use. This means that a violation occurs whether or not the athlete intentionally or unintentionally, knowingly or unknowingly, used a prohibited substance/method or was negligent or otherwise at fault. Athletes are therefore expected to understand not only what is prohibited, but also what might potentially cause an inadvertent doping violation. Yet, as will be discussed, athlete knowledge on doping is deficient and WADA itself sometimes changes its position on prohibited methods or substances. The situation is further confounded by the conflicting stance of anti-doping experts in the media. These highly publicised disagreements may further portray inconsistencies in anti-doping guidelines and suggest to athletes that what is considered doping is dependent on the dominant political zeitgeist. Taken together, athletes may believe that unless a specific and explicit ruling is made, guidelines are open to interpretation. Therefore doping risk-taking behaviours may occur because of the potential financial, social and performance gains and the optimistically biased interpretation (that trying alternatives is part of the ���spirit of sport”) and doping risk-taking behaviours may occur.This discussion paper seeks to situate the reader in a world where elite level sports and CAM intersects. It posits that an understanding of the underlying motivation for CAM use and doping is currently lacking and that anti-doping rules need to be repositioned in the context of the emerging phenomenon and prevalence of CAM use

    Jet Noise Receptivity to Nozzle-upstream Perturbations in Compressible Heated Jets

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97078/1/AIAA2012-2259.pd

    Conformation control of the histidine kinase BceS of <i>Bacillus subtilis</i> by its cognate ABC-transporter facilitates need-based activation of antibiotic resistance

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    Bacteria closely control gene expression to ensure optimal physiological responses to their environment. Such careful gene expression can minimize the fitness cost associated with antibiotic resistance. We previously described a novel regulatory logic in Bacillus subtilis enabling the cell to directly monitor its need for detoxification. This cost-effective strategy is achieved via a two-component regulatory system (BceRS) working in a sensory complex with an ABC-transporter (BceAB), together acting as a flux-sensor where signaling is proportional to transport activity. How this is realized at the molecular level has remained unknown. Using experimentation and computation we here show that the histidine kinase is activated by piston-like displacements in the membrane, which are converted to helical rotations in the catalytic core via an intervening HAMP-like domain. Intriguingly, the transporter was not only required for kinase activation, but also to actively maintain the kinase in its inactive state in the absence of antibiotics. Such coupling of kinase activity to that of the transporter ensures the complete control required for transport flux-dependent signaling. Moreover, we show that the transporter likely conserves energy by signaling with sub-maximal sensitivity. These results provide the first mechanistic insights into transport flux-dependent signaling, a unique strategy for energy-efficient decision making

    Alternative Medicine and Doping in Sports

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    Athletes are high achievers who may seek creative or unconventional methods to improve performance. The literature indicates that athletes are among the heaviest users of complementary and alternative medicine (CAM) and thus may pioneer population trends in CAM use. Unlike non-athletes, athletes may use CAM not just for prevention, treatment or rehabilitation from illness or injuries, but also for performance enhancement. Assuming that athletes’ creative use of anything unconventional is aimed at “legally” improving performance, CAM may be used because it is perceived as more “natural” and erroneously assumed as not potentially doping. This failure to recognise CAMs as pharmacological agents puts athletes at risk of inadvertent doping.The general position of the World Anti-Doping Authority (WADA) is one of strict liability, an application of the legal proposition that ignorance is no excuse and the ultimate responsibility is on the athlete to ensure at all times whatever is swallowed, injected or applied to the athlete is both safe and legal for use. This means that a violation occurs whether or not the athlete intentionally or unintentionally, knowingly or unknowingly, used a prohibited substance/method or was negligent or otherwise at fault. Athletes are therefore expected to understand not only what is prohibited, but also what might potentially cause an inadvertent doping violation. Yet, as will be discussed, athlete knowledge on doping is deficient and WADA itself sometimes changes its position on prohibited methods or substances. The situation is further confounded by the conflicting stance of anti-doping experts in the media. These highly publicised disagreements may further portray inconsistencies in anti-doping guidelines and suggest to athletes that what is considered doping is dependent on the dominant political zeitgeist. Taken together, athletes may believe that unless a specific and explicit ruling is made, guidelines are open to interpretation. Therefore doping risk-taking behaviours may occur because of the potential financial, social and performance gains and the optimistically biased interpretation (that trying alternatives is part of the “spirit of sport”) and doping risk-taking behaviours may occur.This discussion paper seeks to situate the reader in a world where elite level sports and CAM intersects. It posits that an understanding of the underlying motivation for CAM use and doping is currently lacking and that anti-doping rules need to be repositioned in the context of the emerging phenomenon and prevalence of CAM use

    TRANSFER - Trading Approaches to Nurturing Sustainable consumption in Fashion and Energy Retail

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    ESRC funded this project explores how energy and fashion retailers face the common challenge of encouraging the reduced consumption of a saleable product in order to promote sustainability and conform to existing and emerging legislation, while simultaneously maintaining growth and financial prosperity. Energy retailers are experienced in such practices having been legally required to promote energy-efficiency to consumers for some years. This is paired with a growing recognition among fashion retailers of the need to engage in activities that help to promote sustainable consumption among consumers. An installation took place in Feb 2014 in Leeds, inviting the public to visit the TRANSFER factory and chat with a specialist team who asked a series of questions derived from their research about shopping habits. Answers to the questions directly informed how the participants T-Shirt was manufactured, from the colour to the pattern and print. At the end of the interview a personalised manufacturing docket was passed to a group of skilled makers and machinists. The interviewee was then be able to watch their T-Shirt being brought to life by the team. Each garment was a unique money can’t buy item to their exact specifications. Each shopper to visit the exhibition was invited to be photographed for the project and asked what shopping and style means to them. A project website has been created, as well as animations and films. In September 2015 the project film & animation was launched (http://www.project-transfer.com/public-engagement-impact/). Two further films sharing the process behind the project and the public response to the work were published in April 2016 (https://www.youtube.com/watch?v=IwtkLB-G-BQ and https://www.youtube.com/watch?v=FBZ0B8QmGBc). Principal Investigator: Christopher Jones (Psychology, University of Sheffield) Co-Investigators: Lenny Koh (Management, Sheffield); Helen Storey, Alex McIntosh, Professor Dilys Williams (University of the Arts London
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