לוח שנה משולב

One hundred sixty years after its discovery, the molecular mechanism of general anesthesia remains a notable mystery. A very wide range of agents ranging from the element xenon to steroids can act as general anesthetics on all animals from protozoa to man, suggesting that a basic cellular mechanism is involved. Electron spin resonance measurements show that volatile general anesthetics cause large changes in electron spin content of Drosophila fruit flies and that the spin responses are different in anesthesia-resistant mutants. These observations are consistent with the idea that general anesthetics perturb electron currents in cells. Electronic structure calculations on anesthetic–protein interactions are consistent with this mechanism and account for hitherto unexplained features of general anesthetic pharmacology.

Collectively carrying a large load requires a high degree of coordination and is, in fact, extremely rare outside humans and ants. We show that cooperative transport by Paratrechina longicornis ants is indeed non-trivial and exhibits two seemingly contradicting traits. On the one hand, ants conform to the collective motion of the group as a whole thus avoiding inefficient conflicts ; on the other hand, the system maintains sensitivity to a single informed leader. By comparing our data with a minimal theoretical model, we find that decision making at the level of the single ant is balanced at an intermediate level between independence and compliance. Macroscopically, this poises the collective motion at a transition region between random walk and ballistic motion. We demonstrate, both theoretically and experimentally, that this region is near optimal in terms of the response to the steering by a single leader. Our findings suggest that efficient group level processes can arise from transient amplification of individual-based knowledge.