14,267 research outputs found
Factors influencing the publication of health research
Objectives: Assess the degree to which research project findings were published and explore factors that influenced publication. Methods: Questionnaire to project leaders. Classification of publications and findings. Chi-squared; univariate and multivariate Cox regression analyses. Results: Forty percent of projects published in peer-reviewed journal; highly statistically significant relationships between publication in peer-reviewed journals and (1) projects in Responsive/Fellowships streams (p = .045); and (2) projects awarded >pound22,713 (p = .02); influence of study findings not statistically significant. Conclusions: Funders should consider the significant number of studies that did not result in publication and the higher rate of publication in peer-reviewed journals from some programs
Hamming Approximation of NP Witnesses
Given a satisfiable 3-SAT formula, how hard is it to find an assignment to
the variables that has Hamming distance at most n/2 to a satisfying assignment?
More generally, consider any polynomial-time verifier for any NP-complete
language. A d(n)-Hamming-approximation algorithm for the verifier is one that,
given any member x of the language, outputs in polynomial time a string a with
Hamming distance at most d(n) to some witness w, where (x,w) is accepted by the
verifier. Previous results have shown that, if P != NP, then every NP-complete
language has a verifier for which there is no
(n/2-n^(2/3+d))-Hamming-approximation algorithm, for various constants d > 0.
Our main result is that, if P != NP, then every paddable NP-complete language
has a verifier that admits no (n/2+O(sqrt(n log n)))-Hamming-approximation
algorithm. That is, one cannot get even half the bits right. We also consider
natural verifiers for various well-known NP-complete problems. They do have
n/2-Hamming-approximation algorithms, but, if P != NP, have no
(n/2-n^epsilon)-Hamming-approximation algorithms for any constant epsilon > 0.
We show similar results for randomized algorithms
BIOTECHNOLOGY REGULATIONS AND THE WTO
This paper examines the regulation of trade in genetically modified organisms (GMOs) by the World Trade Organization (WTO). Despite rapid adoption of GMOs by a few exporters, many importers have developed relatively restrictive procedures for pre-market approval of GMOs, and are introducing mandatory labeling. While exporters have yet to seek a ruling from the WTO on these regulations, a trade dispute over GMOs is likely to occur before too long. Exporting countries will likely argue that importing countries' regulations are too restrictive, given existing scientific knowledge of the safety of current GM crops, and that labeling of GM foods is unnecessary due to the fact that they are typically similar to their conventional counterparts. In response, importing countries will likely argue that existing scientific knowledge about GMOs is insufficient, and that a precautionary approach to approval is appropriate. In addition, importers will claim that labeling is necessary due to the fact that they are not equivalent to their conventional counterparts, and consumers have a right to choose whether or not consume such foods, be it for religious, ethical or other reasons. In the event a panel will have decide on whether GM and non-GM products are "like goods", whether adequate risk assessment was undertaken for any regulation introduced for health reasons, whether labels constitute the "least trade distorting" way of meeting legitimate objectives, and whether regulations imply discrimination among suppliers or in favor of domestic producers. Experience with the SPS and TBT Agreements has not been extensive enough to indicate how such a panel might rule. But one can also view the issue in broader trade policy terms, as a balance between market access obligations that need to be adjusted as domestic regulations on new technologies are developed. A possible solution is for importing countries with tough GM regulation and mandatory labeling to offer reciprocal increases in market access for non-GM foods in compensation for any losses of market access for GM foods. There is a question though of whether such "rebalancing" is actually practical, and it would certainly add to the costs of dispute settlement in the WTO, but it may be the only viable solution in the long run if the WTO is not to be dragged in to evaluating social and ethical bases for regulation of biotechnology.Biotechnology, regulation, trade, WTO, International Relations/Trade, Research and Development/Tech Change/Emerging Technologies,
Structure of l-Benzyl-2,2,3,3-tetramethyl-l-phenylphosphetanium Bromide, a Cyelobutane Derivative
Flight crew aiding for recovery from subsystem failures
Some of the conceptual issues associated with pilot aiding systems are discussed and an implementation of one component of such an aiding system is described. It is essential that the format and content of the information the aiding system presents to the crew be compatible with the crew's mental models of the task. It is proposed that in order to cooperate effectively, both the aiding system and the flight crew should have consistent information processing models, especially at the point of interface. A general information processing strategy, developed by Rasmussen, was selected to serve as the bridge between the human and aiding system's information processes. The development and implementation of a model-based situation assessment and response generation system for commercial transport aircraft are described. The current implementation is a prototype which concentrates on engine and control surface failure situations and consequent flight emergencies. The aiding system, termed Recovery Recommendation System (RECORS), uses a causal model of the relevant subset of the flight domain to simulate the effects of these failures and to generate appropriate responses, given the current aircraft state and the constraints of the current flight phase. Since detailed information about the aircraft state may not always be available, the model represents the domain at varying levels of abstraction and uses the less detailed abstraction levels to make inferences when exact information is not available. The structure of this model is described in detail
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