Regret testing: learning to play Nash equilibrium without knowing you have an opponent

A learning rule is uncoupled if a player does not condition his strategy on the opponent's payoffs. It is radically uncoupled if a player does not condition his strategy on the opponent's actions or payoffs. We demonstrate a family of simple, radically uncoupled learning rules whose period-by-period behavior comes arbitrarily close to Nash equilibrium behavior in any finite two-person game.Learning, Nash equilibrium, regret, bounded rationality

Saline Conversion and Ice Structures from Artificially Grown Sea Ice

The environment of cold regions is generally viewed as inhospitable, primarily due to application of ideal processes and techniques suitable to temperate zones. The work herein is a step toward solving two environmental problems. The first involves the supply of inexpensive, potable water in Arctic regions, the lack of which is a severe detriment to development. Although water does exist in the Arctic, it is neither available in potable form during many months of the year nor does it occur in sufficient quantity near the point of use. Principally, this lack is caused by the aridness of the Arctic and the shallowness of fresh water sources which, for all practical purposes, do not exist but freeze completely each winter season. The remaining liquid water source is the sea. Arctic problems are then similar to other arid regions where the conversion of sea water to potable water or the transmission of potable water to desired locations is necessary. Cold temperatures generally preclude transmission except over very short distances. Desalination by freezing sea water is a much reported process and has been included among the desalination processes under study worldwide. The advantage of this method in the Arctic is the cold winter-time temperature for freezing and the existence of adequate solar energy in the summer for melting self purified ice. Power requirements are greatly reduced using these natural phenomena. The second aspect of this study concerns the use of artificially grown sea ice as a structural material, thinking primarily in terms of coastal facilities such as docks, jetties, islands, platforms, etc. At sufficiently high latitudes, the summer ablation can be controlled to the point where major structures can be maintained intact during the summer. The unit cost of material is quite low because of low energy requirements. The results of this study show that each of these sea water uses have considerable promise. Desalination to potable level was accomplished. Ice growth rates were obtained which indicate that ice structures of substantial size can be built.This project was accomplished under a matching grant between the Office of Water Resources Research, Department of the Interior, and the University of Alaska, Arctic Environmental Engineering Laboratory. Funds available under this grant purposefully did not anticipate the heavy logistic expense in moving the project and equipment from Fairbanks to Kotzebue, Alaska. Therefore, a major third contributor was the Alaska Air National Guard, Kulis Air Force Base, Alaska. The support offered by the officers and men of the Alaska Air National Guard was excellent and greatly appreciated

Mechanistic Rationale for Ketene Formation During Dabbing and Vaping

Ketene is one of the most toxic vaping emissions identified to date. However, its high reactivity renders it relatively challenging to identify. In addition, certain theoretical studies have shown that realistic vaping temperature settings may betoo low to produce ketene. Each of these issues is addressed herein. First, an isotopically labeled acetate precursor is used for the identification of ketene with enhanced rigor in vaped aerosols. Second, discrepancies between theoretical and experimental findings are explained by accounting for the effects of aerobic (experimental) versus anaerobic (simulated and theoretical) pyrolysis conditions. This finding is also relevant to explaining the relatively low-temperature production of aerosol toxicants beyond ketene. Moreover, the study presented herein shows that ketene formation during vaping is not limited to molecules possessing a phenyl acetate substructure. This means that ketene emission during vaping, including from popular flavorants such as ethyl acetate, may be more prevalent than is currently known

Mitigation of off-target toxicity in CRISPR-Cas9 screens for essential non-coding elements.

Pooled CRISPR-Cas9 screens are a powerful method for functionally characterizing regulatory elements in the non-coding genome, but off-target effects in these experiments have not been systematically evaluated. Here, we investigate Cas9, dCas9, and CRISPRi/a off-target activity in screens for essential regulatory elements. The sgRNAs with the largest effects in genome-scale screens for essential CTCF loop anchors in K562 cells were not single guide RNAs (sgRNAs) that disrupted gene expression near the on-target CTCF anchor. Rather, these sgRNAs had high off-target activity that, while only weakly correlated with absolute off-target site number, could be predicted by the recently developed GuideScan specificity score. Screens conducted in parallel with CRISPRi/a, which do not induce double-stranded DNA breaks, revealed that a distinct set of off-targets also cause strong confounding fitness effects with these epigenome-editing tools. Promisingly, filtering of CRISPRi libraries using GuideScan specificity scores removed these confounded sgRNAs and enabled identification of essential regulatory elements