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).

UPARSE annotations

See also: uparse_ref, cluster_otus.

Field		Description
n=k;		Number of segments in the model. If n>1, the model is chimeric. If n=?, the model is too far diverged from the query sequence for parsimony to be reliable. The divergence is measured using the divqm field (see below). The -uparse_annot_maxdivqm option specifies the maximum allowed divergence; default is 1.0.
diffsqm=d;		Number of differences between the query sequence and model. A difference is a substitution or indel (one gap symbol). If diffsqm=0, this indicates the model is identical to the query. If diffsqm>0, this is interpreted as due to point errors (sequencing error or PCR copying mistakes).
dqt=d;		Divergence between query and top hit in the database as a percentage, calculated as 100% - PctId(Query, TopHit). Sequence identity is calculated from a global alignment.
dqm=d;		Divergence between query and model, as a percentage, calculated as 100% - PctId(Query, Model).
top=label;		Label of database top hit.
parents=string;		Included only if the model is chimeric. The string specifies the segments used to construct the model. Each segment is specified as label(from-to), where from and to are the 1-based coordinates.