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The dynamics of phosphocholine and maltoside micelles, detergents frequently used for membrane protein structure determination, were investigated using electron paramagnetic resonance of spin probes doped into the micelles. Specifically, phosphocholines are frequently used detergents in NMR studies, and maltosides are frequently used in x-ray crystallography structure determination. Beyond the structural and electrostatic differences, this study aimed to determine whether there are differences in the local chain dynamics (i.e., fluidity). The nitroxide probe rotational dynamics in longer chain detergents is more restricted than in shorter chain detergents, and maltoside micelles are more restricted than phosphocholine micelles. Furthermore, the micelle microviscosity can be modulated with mixtures, as demonstrated with mixtures of 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate with n-dodecylphosphocholine, n-tetradecylphosphocholine, n-decyl-b-D-maltoside, or n-dodecyl-b-D-maltoside. These results indicate that observed differences in membrane protein stability in these detergents could be due to fluidity in addition to the already determined structural differences.

In the originally published article, some funding information was omitted from the Acknowledgments. The authors regret any inconvenience this may have caused. The correct wording is:

No abstract

Video game research predominantly uses a “one game-one function” approach—researchers deploy a constellation of task-like minigames to span multiple domains or consider a complex video game to essentially represent one cognitive construct. To profile cognitive functioning in a more ecologically valid setting, we developed a novel 3-D action shooter video game explicitly designed to engage multiple cognitive domains. We compared gameplay data with results from a web-based cognitive battery (WebCNP) for 158 participants (aged 18–74). There were significant negative main effects on game performance from age and gender, even when controlling for prior video game exposure. Among younger players, game mechanics displayed significant and unique correlations to cognitive constructs such as aim accuracy with attention and stealth with abstract thinking within the same session. Among older players the relation between game components and cognitive domains was unclear. Findings suggest that while game mechanics within a single game can be deconstructed to correspond to existing cognitive metrics, how game mechanics are understood and utilized likely differs between the young and old. We argue that while complex games can be utilized to measure distinct cognitive functions, the translation scheme of gameplay to cognitive function should not be one-size-fits-all across all demographics.