The lower (hat{q}) value for ({text{NO}}_{2}^) indicates a bottleneck on the denitrification pathway, i.e., when ({text{NO}}_{3}^) is present at non-rate-limiting concentrations, ({text{NO}}_{2}^) necessarily accumulates, and the observed rate of N2O reduction is limited to the maximum rate of N2O formation from ({text{NO}}_{2}^).
M ratio below Mc indicates a bottleneck (in italics) Genetic signatures of population bottlenecks were detected, although there was disagreement between the different tests used.
Calculated fluxes indicated a bottleneck at NO3, which was relieved upon O2 depletion.
They found that plants without this gene would accumulate a buildup of reticuline, indicating a bottleneck in the production pipeline.
Dr. Nielsen said that the figure of 288 people was meant simply to indicate a bottleneck in the Han population, meaning a time when it was very small, and that this bottleneck could just as easily have occurred 10,000 years ago.
Uniformly positive values of neutrality tests in this region may indicate a bottleneck in these populations, although it is unclear whether this result could be related to anthropogenic factors.
Furthermore, a very recent simulation study by Städler et al. [ 31] confirmed that even when populations are undergoing a very important spatial expansion, Tajima's D can exhibit positive values (apparently indicating a bottleneck).
As a negative value for Tajima's D can also indicate a bottleneck, a high number of negative values of Tajima's D at any distance from an LCR can be expected between human sequences; however, the presence of an LCR clearly increases the proportion of sites in accord with more negative selection.
Using computer simulations, Antao et al. (2010) evaluated the ability of NeD and NeV estimators to (i) detect a population decline, (ii) correctly identify a bottleneck with low bias and high precision, and (iii) evaluate whether the methods were subject to a high rate of false positives (i.e., indicate a bottleneck when none had occurred).
Furthermore, there appears to be no clustering by sample age; ancient samples do not seem to cluster together, nor do they appear only at the centre of the networks (as might indicate an expansion event from the ancient samples), nor do they appear only at the edges of the networks (as could indicate a bottleneck).
For each mutation model, we compared observed heterozygosities and expected heterozygosities simulated 10 000 times from the allele number at equilibrium using two-tailed Wilcoxon tests, where values significantly larger than expected indicate a bottleneck, and values significantly smaller than expected indicate demographic growth.
