Presentation given to the BEACON 2013 Congress during the "Collaborating with Industry" sandbox
Original w/ slide notes at: https://docs.google.com/presentation/d/1mmvD0R3fLIl11TmFHij5fGcMDb9qJxy_nwENO2Rt-YI/edit?usp=sharing
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Better science through superior software
1. Better science through
superior software
Michael R. Crusoe
Software Engineer & Bioinformatician
The GED Lab @ Michigan State
mcrusoe@msu.edu @biocrusoe
2. Open, online science
Much of the software and approaches talked
about today are available:
khmer software:
http://github.com/ged-lab/khmer/
Titus’s blog: http://ivory.idyll.org/blog/
Titus’s twitter: @ctitusbrown
3. Overview
● Next-gen sequencing data deluge
● ♫How do you solve a problem like big data?♫
● Impact of khmer software
● Future work
● Being a good F/OSS community member and
leading by example
● Acknowledgements
4. Problem
“The power of next-gen. sequencing: get 180x
coverage... and then watch your assemblies
never finish” - Erich Schwarz
5. “Three types of data scientists.”
(Bob Grossman, U. Chicago, at XLDB 2012)
1. Your data gathering rate is slower than
Moore’s Law.
2. Your data gathering rate matches Moore’s
Law.
3. Your data gathering rate exceeds Moore’s
Law.
6.
7. “Three types of data scientists.”
1. Your data gathering rate is slower than Moore’
s Law.
=> Be lazy, all will work out.
2. Your data gathering rate matches Moore’s
Law.
=> You need to write good software, but all will
work out.
3. Your data gathering rate exceeds Moore’s Law.
=> You need serious help.
8. A software & algorithms approach: can we
develop lossy compression approaches that
1. Reduce data size & remove errors => efficient
processing?
2. Retain all “information”? (think JPEG)
If so, then we can store only the compressed
data for later reanalysis. Short answer is: yes,
we can.
9. Digital normalization approach
A digital analog to cDNA library normalization,
diginorm:
● Reference free.
● Is single pass: looks at each read only once;
● Does not “collect” the majority of errors;
● Keeps all low-coverage reads & retains all
information.
10. GED Lab’s approach: khmer
diginorm: ejects most data while retaining the
information content.
partitioning: split transcriptomic and meta
{transcript,gen}omic datasets
fast k-mer counting: for better preprocessing,
repeat detection, and sequencing coverage
estimates
Reference-free variant calling
- More to come -
12. Impact
● any biologist can use our tools in a rented
cloud computer, cheaply
● Overcome complexity: Erich Schwarz
assembled H. contortus when it was
previously not possible.
● Overcome data excess: 5.1 billion reads from
50 different sea lamprey tissue -> diginorm
technique removed 98.7% for being
redundant.
13. Future work
● targeted-gene assembly from short reads
(Fish et al., Ribosomal Database Project)
● rRNA search in shotgun data
● error-correction for mRNAseq &
metagenomic data
● strain variation collapse, assembly, and
recovery
● Goal: make most assembly easy and all
evaluation easy.
14. Interactions
khmer both builds upon existing Free and
Open-Source Software (F/OSS) and is itself
made under an open-source license.
used in curriculum: both Software Carpentry
ANGUS based courses and the MSU NGS
summer course
15. ● BIG DATA grant reviewers specifically
mentioned the GED Lab’s “[...] long and
successful track-record and experience in
following rigorous but open software
development processes.” -> CTB received 3-
year NIH R01 support
● Transparent and public software
development yielded participation from
others.