- Google Scholar was observed to have missed indexing an arXiv paper, prompting discussion on Hacker News about gaps in academic search coverage.  
- Jenda` raised the question of whether “adversarial examples” can be crafted to fool biological neural networks; mnemon countered that natural camouflage and optical illusions already serve this function, citing butterfly eye-spots as living adversarial patterns.  
- A Nature Communications paper (DOI: s41467-019-09557-4) was shared, reporting that deep-brain stimulation of the internal capsule can enhance human cognitive control and boost prefrontal-cortex function.  
- fenn investigated the unusually high vitamin K2 (MK-4) content in goose liver, hypothesizing that grass-fed diets and superior avian conversion of K1 to K2-MK4 explain the anomaly compared with grain-fed livestock.