In this paper, we argue that prototypes can hinder, rather than aid effective communication. The dangers are: (1) prototypes may contain hidden assumptions which might surface too late; (2) obtaining feedback in the context of use is prohibitively expensive and rarely done; and (3) partly as a consequence of these problems, prototypes cause a focus on displays and other surface features of comp...

In this paper we prove an exponential separation between two very similar and natural SAT encodings for the same problem, thereby showing that researchers must be careful when designing encodings, lest they accidentally introduce complexity into the problem being studied. This result provides a formal explanation for empirical results showing that the encoding of a problem can dramatically affe...

Dangerous Anthropogenic Interference The United Nations Framework Convention on Climate Change (UNFCCC) commits signatory nations (which includes all major nations including the United States) to stabilizing greenhouse gas concentrations at levels short of DAI. To properly define DAI, one must take into account issues that are not only scientific, but, as I have argued elsewhere (2), economic, ...

A dangerous bias Sir, In their recently published paper (Domar et al., 2013), the authors' conclusion that 'there is little evidence of benefit from the antide-pressants prescribed for the majority of women of childbearing age—and there is ample evidence of risk', is based on a biased reading of the literature. Rather than including a balanced analysis of the studies on the subject, they cite f...

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A 76-year-old man developed a hemoperitoneum after ERCP for choledocholithiasis. He underwent a laparotomy and splenectomy for a capsular tear at the splenic hilum, a rare complication of ERCP. "Bowing" of the endoscope with torsion on the greater curvature of the stomach may lead to shear forces causing splenic injury.

Aravanis C, Blackburn H, Buzina R, Dontas AS, Fidanza F. Serum total cholesterol and long-term coronary heart disease mortality in different cultures. Twenty-five-year follow-up of the seven countries study. JAMA 1995;274:131–136. 37. Holvoet P, Vanhaecke J, Janssens S, Van de Werf F, Collen D. Oxidized LDL and malondialdehyde-modified LDL in patients with acute coronary syndromes and stable co...

Altogether 85 eyes from patients at risk to the development of closed-angle glaucoma were dilated with either parasympatholytic or sympathomimetic drugs. Of 21 eyes dilated with cyclopentolate 1/2%, 9 developed angle closure and a significantly raised pressure at some stage during dilatation and subsequent miosis. Of 58 eyes dilated with tropicamide 1/2%, 19 developed angle closure and a signif...

A dangerous border collision bifurcation has been defined as the dynamical instability that occurs when the basins of attraction of stable fixed points shrink to a set of zero measure as the parameter approaches the bifurcation value from either side. This results in almost all trajectories diverging off to infinity at the bifurcation point, despite the eigenvalues of the fixed points before an...