Video talks on 16S data analysis posted.

URMAP ultra-fast read mapper posted (paper).

~20% of taxonomy annotations in SILVA and Greengenes are wrong (paper).

Taxonomy prediction is <50% accurate for 16S V4 sequences (paper).

97% OTU threshold is wrong for species, should be 99% for full-length 16S, 100% V4 (paper).

Bray-Curtis beta diversity metric

See also
beta_div command
Beta diversity metrics

The Bray-Curtis metric between samples i and j is calculated as follows.

N = number of OTUs.

n_ki = count of OTU k in sample i.

S = sum k = 1 .. N of min(n_ki, n_kj)

T = sum k = 1 .. N of (n_ki + n_kj)

Bray-Curtis = 1 - 2 S / T