What Is Imidazoline Receptor

Alley crossing time t of a non-structured population, as a function of its carrying capacity K, PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/20171653 in logarithmic scale. Dots are simulation outcomes, averaged more than 1000 runs for each and every worth of K; error bars represent 95 confidence intervals (CI). Theoretical predictions from Ref. [28] are plotted for the sequential fixation regime (blue line) and for the TPO agonist 1 web tunneling regime (red line), applying N 0:9K (see text) to create the correspondence. The transition involving these two regimes is indicated by a dotted line. The carrying capacities at stake in D are highlighted in green (id: isolated deme; ns: non-subdivided population). Parameter values: d 0:1, m 8|ten{6 , s 0:3 and d 6|10{3 . D. Average valley crossing time tm of a metapopulation composed of D 7 demes each with carrying capacity K 357 (total carrying capacity: DK 2499), plotted versus the migration-to-mutation rate ratio m=(md), in logarithmic scale. Parameter values are the same as in C, and only the migration rate m is varied. Dots represent simulation results averaged over 1000 runs for each value of m, and error bars are 95 CI. Black vertical lines represent the limits of the interval of m=(md) in Eq. 14. Blue (resp. red) line: valley crossing time for an isolated deme (id) with K 357 (resp. a non-subdivided population (ns) with K 2500) for the same parameter values, averaged over 1000 runs; shaded regions: 95 CI. Dashed blue (resp. red) lines: corresponding theoretical predictions from Ref. [28] (see C). doi:10.1371/journal.pcbi.1003778.gWe now focus on this best possible scenario, which is illustrated schematically in Fig. 1B: first, the champion deme crosses the valley or plateau by sequential fixation, and then the beneficial mutation rapidly spreads by migration of through the whole metapopulation. Once this best possible scenario is characterized, the crucial question will be whether, and under what conditions, it can be attained: this point will be addressed in the following section. Determination of tc . Valley or plateau crossing by a nonstructured, well-mixed population can occur by two different mechanisms: sequential fixation and tunneling. The former corresponds to fixation of mutation `1′ in the whole population, and to subsequent fixation of the beneficial mutation `2′. Conversely, the latter occurs when the beneficial mutation arises in a small fluctuating minority of first-mutants, and fixes directly: tunneling does not involve fixation of the intermediate mutation `1′ [28]. For given values of the parameters d, s, and m, sequential fixation is the fastest process for small populations, where genetic drift plays an important part. Tunneling becomes the dominant process of valley or plateau crossing when the number N of individuals per deme exceeds a threshold value N| , which depends on d, s, and m (see Ref. [28] for a full discussion of this threshold value). Fig. 1C shows simulation results for the valley crossing time t of a non-subdivided population versus its size, and illustrates these two different regimes and the transition between them. Note that in our simulations (described in Methods, Sec. 1), we hold fixed the carrying capacity K of populations (or demes) instead of the number of individuals N. This softer constraint is more realistic and avoids some possible biases in the metapopulation case (see Methods, Sec. 1.2). In practice, each individualPLOS Computational Biology | www.ploscompbiol.orgdivides at a rate f (1{N=K) and dies at a constant rate d: hence,.