Xian Chang
@xian-chang.bsky.social
Bioinformatics postdoc at INRAE in Toulouse, France.
Working on data structures and algorithms for pangenome graphs
Working on data structures and algorithms for pangenome graphs
Reposted by Xian Chang
I've added 7 videos to my Burrows-Wheeler indexing playlist (www.youtube.com/playlist?lis...), rounding out the r-index series and adding a 5-part series on the move structure. Now 27 videos in that playlist. I aim to add videos on prefix-free parsing, PBWT, Wheeler languages/automata in the future.
Burrows-Wheeler Indexing - YouTube
Videos on : (a) the Burrows-Wheeler Transform (BWT), (b) the FM Index, which uses the BWT to construct a full-text index, (c) Wheeler graphs, (d) r-index, an...
www.youtube.com
October 7, 2025 at 2:17 PM
I've added 7 videos to my Burrows-Wheeler indexing playlist (www.youtube.com/playlist?lis...), rounding out the r-index series and adding a 5-part series on the move structure. Now 27 videos in that playlist. I aim to add videos on prefix-free parsing, PBWT, Wheeler languages/automata in the future.
🦒Long read giraffe is out!🦒
Mapping long reads to pangenome graphs is ~10x faster than with GraphAligner, with veeery slightly better mapping accuracy, short variant calling, and SV genotyping than GraphAligner or Minimap2
Mapping long reads to pangenome graphs is ~10x faster than with GraphAligner, with veeery slightly better mapping accuracy, short variant calling, and SV genotyping than GraphAligner or Minimap2
Rapid, accurate long- and short-read mapping to large pangenome graphs with vg Giraffe https://www.biorxiv.org/content/10.1101/2025.09.29.678807v1
October 2, 2025 at 6:28 AM
🦒Long read giraffe is out!🦒
Mapping long reads to pangenome graphs is ~10x faster than with GraphAligner, with veeery slightly better mapping accuracy, short variant calling, and SV genotyping than GraphAligner or Minimap2
Mapping long reads to pangenome graphs is ~10x faster than with GraphAligner, with veeery slightly better mapping accuracy, short variant calling, and SV genotyping than GraphAligner or Minimap2
Reposted by Xian Chang
Republicans are shutting down the government to stop you from having healthcare—there’s the message!!!!
October 1, 2025 at 2:47 PM
Republicans are shutting down the government to stop you from having healthcare—there’s the message!!!!
I'm very excited to share that I defended my thesis this week! I helped develop algorithms to combat reference #bias and make genomics more #equitable and #representative by incorporating genetic #diversity into genomics pipelines
March 21, 2025 at 11:00 PM
I'm very excited to share that I defended my thesis this week! I helped develop algorithms to combat reference #bias and make genomics more #equitable and #representative by incorporating genetic #diversity into genomics pipelines
Reposted by Xian Chang
We use personalized references with our Giraffe aligner. Each chromosome is partitioned into a sequence of blocks. We sample the most relevant haplotypes in each block using kmer counts. Mapping to this personalized reference improves variant calling accuracy. www.nature.com/articles/s41...
Personalized pangenome references - Nature Methods
This work introduces a k-mer-based approach to customizing a pangenome reference, making it more relevant to a new sample of interest. This method enhances the accuracy of genotyping small variants an...
www.nature.com
March 4, 2025 at 11:00 PM
We use personalized references with our Giraffe aligner. Each chromosome is partitioned into a sequence of blocks. We sample the most relevant haplotypes in each block using kmer counts. Mapping to this personalized reference improves variant calling accuracy. www.nature.com/articles/s41...
Reposted by Xian Chang
Welcome to the Bluesky account for Stand Up for Science 2025!
Keep an eye on this space for updates, event information, and ways to get involved. We can't wait to see everyone #standupforscience2025 on March 7th, both in DC and locations nationwide!
#scienceforall #sciencenotsilence
Keep an eye on this space for updates, event information, and ways to get involved. We can't wait to see everyone #standupforscience2025 on March 7th, both in DC and locations nationwide!
#scienceforall #sciencenotsilence
February 12, 2025 at 5:04 PM
Welcome to the Bluesky account for Stand Up for Science 2025!
Keep an eye on this space for updates, event information, and ways to get involved. We can't wait to see everyone #standupforscience2025 on March 7th, both in DC and locations nationwide!
#scienceforall #sciencenotsilence
Keep an eye on this space for updates, event information, and ways to get involved. We can't wait to see everyone #standupforscience2025 on March 7th, both in DC and locations nationwide!
#scienceforall #sciencenotsilence
New figure for my thesis showing why Giraffe is the best long read pangenome mapper. No further evidence will be provided.
February 14, 2025 at 7:45 PM
New figure for my thesis showing why Giraffe is the best long read pangenome mapper. No further evidence will be provided.
Reposted by Xian Chang
Researchers at @ucsantacruz.bsky.social have demonstrated how long-read sequencing could improve detection of diseases that have eluded diagnosis, at a fraction of the cost. New clinical tests could be on the way.
🗞 news.ucsc.edu/2025/01/pate...
👏🏼👏🏿👏🏾 @khmiga.bsky.social @benedictpaten.bsky.social
🗞 news.ucsc.edu/2025/01/pate...
👏🏼👏🏿👏🏾 @khmiga.bsky.social @benedictpaten.bsky.social
January 24, 2025 at 7:17 PM
Researchers at @ucsantacruz.bsky.social have demonstrated how long-read sequencing could improve detection of diseases that have eluded diagnosis, at a fraction of the cost. New clinical tests could be on the way.
🗞 news.ucsc.edu/2025/01/pate...
👏🏼👏🏿👏🏾 @khmiga.bsky.social @benedictpaten.bsky.social
🗞 news.ucsc.edu/2025/01/pate...
👏🏼👏🏿👏🏾 @khmiga.bsky.social @benedictpaten.bsky.social