- Allows you to search through public studies to find comparable data to your own
- Can search by: metadata, feature, or taxon
redbiom is a cache service which can be used to search databases for samples which contain particular taxonomic units or given features (e.g. environmental or clinical factors); either as a Qiita plugin, or as a separately installed command line package. redbiom can therefore be used to identify samples for a meta-analysis focused on some particular factor (or factors). The utility of searching by metadata or feature is that it allows the discovery and subsequent use of a potentially wide variety of samples. This may include data from studies with completely different research goals, which one would have otherwise been unlikely to realize could be used.
Note that a cache service is a high-speed data storage layer which stores a subset of data allowing a more rapid searching and retrieval experience. redbiom has a much smaller, sparse vector version of the Qiita database containing mainly metadata, which thus allows rapid searching. Samples found in a redbiom search can then be retrieved from the Qiita database through redbiom for subsequent analysis.
The search will be on the full metadata.
Natural language processing: The metadata search engine uses natural language processing to search for word stems within a sample metadata. A word stem disregards modifiers and plurals, so for instance, a search for antibiotics will actually perform a search for antibiot. Similarly, a search for crying will actually search for cry. The words specified can be combined with set-based operations, so for instance, a search for antibiotics & crying will obtain the set of samples in which each sample has antibiot in its metadata as well as cry.
N.B., the specific category in which a stem is found is not assured to be the same, antibiot could be in one category and cry in another. A set intersection can be performed with “&”, a union with “|” and a difference with “-“.
Value search: In addition to the stem-based search, value based searches can also be applied. These use a Python-like grammar and allow for a rich set of comparisons to be performed based on a metadata category of interest. For examplewhere qiita_study_id == 10317
will find all samples which have the qiita_study_id metadata category, and in which the value for that sample is 10317.
- Find all samples in which both the word ‘infant’, as well as ‘antibiotics’ exist, and where the infants are under a year old:infant & antibiotics where age_years <= 1
Find all samples only belonging to the EMP in which the pH is under 7, for a variety of sample types:
- soil:soil where ph < 7 and emp_release1 == 'True'
- ocean water:water & ocean where ph > 7 and emp_release1 == 'True'
- non-ocean water:water - ocean where ph > 7 and emp_release1 == 'True'
Or instead of pH you could search for a different metadata category:water & ocean where salinity > 20
- Some other interesting examples:feces & canine (beer | cider | wine | alcohol) where sample_type == 'stool' usa where sample_type == 'stool' and host_taxid == 9606
The search will be on all the features, in specific: OTU ids for closed reference or exact sequences for deblur.
- Find all samples in which the Greengenes feature 4479944 is found:4479944
- Find all samples in which the sequence exists:TACGAAGGGTGCAAGCATTACTCGGAATTACTGGGCGTAAAGCGTGCGTAGGTGGTTCGTTAAGTCTGATGTGAAAGCCCTGGGCTCAACCTGGGAACTG
The search will be only on closed reference data and based on the taxonomies available. Only exact matches are returned. Note that currently only the Greengenes taxonomy is searchable, and that it requires nomenclature of a rank prefix, two underscores, and then the name.
- Find all samples in which the genera Escherichia is found:g__Escherichia
- Find all samples in which the phylum Tenericutes is found:p__Tenericutes