Motor planning under temporal uncertainty is suboptimal when the gain function is asymmetric

For optimal action planning, the gain/loss associated with actions and the variability in motor output should both be considered. A number of studies make conflicting claims about the optimality of human action planning but cannot be reconciled due to their use of different movements and gain/loss functions. The disagreement is possibly because of differences in the experimental design and differences in the energetic cost of participant motor effort. We used a coincident timing task, which requires decision making with constant energetic cost, to test the optimality of participant’s timing strategies under four configurations of the gain function. We compared participant strategies to an optimal timing strategy calculated from a Bayesian model that maximizes the expected gain. We found suboptimal timing strategies under two configurations of the gain function characterized by asymmetry, in which higher gain is associated with higher risk of zero gain. Participants showed a risk-seeking strategy by responding closer than optimal to the time of onset/offset of zero gain. Meanwhile, there was good agreement of the model with actual performance under two configurations of the gain function characterized by symmetry. Our findings show that human ability to make decisions that must reflect uncertainty in one’s own motor output has limits that depend on the configuration of the gain function

Uncertainty analysis of the power law extrapolation techniques for adhesive anchors

Modern construction industry is increasingly utilizing postinstalled adhesive anchors as an alternative to traditional mechanical anchors. Although the application of adhesive anchors under sustained load offers many advantages, the associated approval guidelines based on a power law extrapolation technique have a number of ambiguities and limitations, which are shortly reviewed in this paper and subjected to uncertainty quantification and sensitivity analyses. Some of the observations presented may be considered as specific to the available experimental database of sustained load test, while some recommendations are universal, as they relate to the underlying creep phenomena and robust measures in regression. It is further shown, how a regression based safety factor could be derived from an experimental database and a possibilistic set of plausible choices

Neuropeptide W

Neuropeptide W (NPW), which was first isolated from the porcine hypothalamus, exists in two forms, consisting of 23 (NPW23) or 30 (NPW30) amino acids. These neuropeptides bind to one of two neuropeptide W receptors, either NPBWR1 (otherwise known as GPR7) or NPBWR2 (GPR8), which belong to the G protein-coupled receptor family. GPR7 is expressed in the brain and peripheral organs of both humans and rodents, whereas GPR8 is not found in rodents. GPR7 mRNA in rodents is widely expressed in several hypothalamic regions, including the paraventricular, supraoptic, ventromedial, dorsomedial, suprachiasmatic and arcuate nuclei. These observations suggest that GPR7 plays a crucial role in the modulation of neuroendocrine function. The intracerebroventricular infusion of NPW has been shown to suppress food intake and body weight and to increase both heat production and body temperature, suggesting that this neuropeptide functions as an endogenous catabolic signaling molecule. Here we summarize our current understanding of the distribution and function of NPW in the brain