EarthDNA reference database: SILVA 144 SSU globe and amplicon placement models

Reference database for placing 16S/18S rRNA amplicon sequence variants (ASVs) on the EarthDNA globe, a spherical t-SNE map of every SILVA 144 SSU Ref NR99 sequence (https://github.com/rec3141/earthdna). Contents (earthdna_silva144-2.tar.gz, directory silva144-2/): map.tsv: full-length reference positions (id, lon, lat) from fastsne --sphere 35 on square-root 5-mer counts (PCA 128). panel.fa, panel_cols.npy, panel_offs.npy: every 40th aligned reference, ungapped, with its alignment columns, used to detect which SSU region an ASV covers (vsearch, both strands). regions/C0-C1.model: fastsne placement models (PCA 64) for 12 amplicon regions, given as SILVA alignment columns: references cut to those columns, carrying their full-length map positions (fastsne --fixed-y). manifest.json: release, radius, regions. Used by the PLACE_GLOBE step of the danaSeq illumina_amplicon pipeline (https://github.com/rec3141/danaSeq) with fastsne v0.3.0 or later (https://github.com/rec3141/fastsne). Built with earthdna pipeline/build_reference.py. Derived from SILVA SSU Ref NR99 release 144 (Quast et al. 2013, Nucleic Acids Res 41:D590-D596; https://www.arb-silva.de), licensed CC BY 4.0. Version silva144-2 adds placement models for three regions found in published runs that version silva144 could not place: alignment columns 31188-41565 (16S ~V6-V8), 1040-13124 and 1043-11891 (16S ~V1-V3 / V1-V2). The map, panel and the other nine models are unchanged.