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).

Jost diversity index

In a 2010 paper, Chao, Chui and Jost describe a family of metrics based on Hill numbers with a single parameter (q) that determines how abundance is weighted. I call these Jost indexes of order q. The numerical value of the metric for any q is an effective number of species.

The parameter q is the power to which the species frequencies are raised. Higher values of q thus give lower weights to low-abundance species. With q=0 the Jost index is exactly equivalent to richness. With q=1, the Jost index is the effective number of species given by the Shannon entropy. The q parameter can take real values, not just integers, which allows intermediate metrics with different weightings of abundance.

Reference
Chao, Chui and Jost (2010)