生物振荡器可携带多少种标签？针对所提出信息载体的品质因子筛选
How many labels can a biological oscillator carry? A quality-factor screen for proposed information carriers
AI总结：
本文提出品质因子Q=2πντ可作为生物振荡器携带标签数量的统一上限，筛选11种信息载体后仅低频神经节律通过，高频分子载体因持续时间短被排除。
AI中文摘要：
生物振荡器能携带多少种可区分的标签？目前关于集体振动模式、内源电磁场、微管激发以及振荡相位编码等相关方案的争论均基于各自特定依据，缺乏统一的比较标准。本文表明，仅频谱可区分性就可通过品质因子对标签数量设定上限，即M ≤ Q = 2πντ，该结论源于线宽与相干时间的关系，因此与底物、机制以及量子效应在生物学中的位置均无关，且可通过两个已发表的量进行评估。将其应用于近期提出的皮层内30GHz柱内微波场，得到Q=0.19，即线宽是该载波的五倍。一个明显的补救方案是受激发射体的频谱可窄于其增益介质，这需要谐振腔，但该模型自身的几何结构不允许存在谐振腔。代谢功率的独立上限被超出了5至9个数量级。从同一视角还得出了另外六个标准，包括要求标签兼具可读性和可重写性的双侧持续窗口。对11种载体进行筛选后，仅低频神经节律通过，高频分子载体因持续时间短被排除，而非如争论所假设的因脆弱性被排除。
英文摘要：
How many distinguishable labels can a biological oscillator carry? Proposals invoking collective vibrational modes, endogenous electromagnetic fields, microtubule excitations and oscillatory phase codes are each debated on grounds particular to themselves, with no shared standard for comparison. We show that spectral distinguishability alone bounds the number of labels by the quality factor, M <= Q = 2 pi nu tau. This follows from the relation between linewidth and coherence time, so it is independent of substrate, of mechanism, and of any position on quantum effects in biology, and it can be evaluated from two published quantities. Applied to a recently proposed 30 GHz intracolumnar microwave field in cortex, it gives Q = 0.19: the linewidth exceeds the carrier five-fold. The obvious rescue, that a driven emitter can be spectrally narrower than its gain medium, requires a resonant cavity, and the model's own geometry forbids one. An independent bound on metabolic power is exceeded by five to nine orders of magnitude. Six further criteria follow from the same standpoint, including a two-sided persistence window requiring a label to be both readable and rewritable. Screening eleven carriers, only the low-frequency neural rhythms pass. High-frequency molecular carriers are eliminated by brevity, not by the fragility the debate has assumed.
