By analyzing ontological differences between two contested concepts, the puzzle and the game, the paper aims at constructing a structural framework for understanding the videogame and its challenges. The framework is built on three basic challenge structures: the puzzle, the strategic challenge, and the kinesthetic challenge. The argument is that, unlike the latter two, the puzzle cannot consti...

We present an algorithm, based on the explicit formula for L-functions and conditional on GRH, for proving that a given integer is squarefree with little or no knowledge of its factorization. We analyze the algorithm both theoretically and practically, and use it to prove that several RSA challenge numbers are not squarefull.

the success rate of embryo production critically depends on several factors. one of the pivotal factors is a technique used for the whole procedure of in vitro fertilization (ivf) and in vitro embryo culture (ivc) (1, 2). besides the technique selected for ivf / in vitro embryo production (ivep), there is an important consideration called ivf/ivep culture dishes disinfection (3). for many years...

The Solubility Challenge is based upon intrinsic solubility data measured in one laboratory for a set of biologically relevant compounds. More than 100 entries to the Solubility Challenge have been received. In several cases multiple entries came from the same person or group. In addition, more than 5% of the prediction sheet entries were incomplete in that predictions were not reported for all...