Goodbye desktop, we're off to see the web.
Both my students and I have been challenged this semester by the diversity of computer platforms, software versions, and unexpected bugs. Naturally, I turned to the world and my readers for help and suggestions. Some readers have suggested we could solve everything by using Linux. Others have ... Read more
I made this video (below the fold) to illustrate the steps involved in making a phylogenetic tree. The basic steps are to:
Build a data set
Align the sequences
Make a tree
In the class that I'm teaching, we're making these trees in order to compare sequences from our metagenomics experiment with the multiple copies of 16S ribosomal RNA (rRNA) genes that we can find in single bacterial genomes. Bacteria contain between 2 to 13 copies of 16S rRNA genes and we' ... Read more
One of my colleagues has a two part series on FinchTalk (starting today) that discusses uncertainty in measurement and what that uncertainty means for the present and Next Generation DNA sequencing technologies.
I've been running into this uncertainty myself lately.
I have always known that DNA sequencing errors occur. This is why people build tools for measuring the error rate and why quality measurements are so useful for determining which data to use and which data to ... Read more
I think all of us; me, the students the OO advocates, a thoughtful group of commenters, some instructors; I think many of us learned some things that we didn't anticipate the other day and got some interesting glimpses into the ways that other people view and interact with their computers.
Some of the people who participated in the challenge found out that it was harder than they expected.
Okay, what did we learn?
1. The community is the ... Read more
Okay OpenOffice fans, show me what you can do.
Earlier this week, I wrote about my challenges with a bug in Microsoft Excel that only appears on Windows computers. Since I use a Mac, I didn't know about the bug when I wrote the assignment and I only found out about it after all but one of my students turned in assignment results with nonsensical pie graphs.
So, I asked what other instructors do with software that behaves differently on different computing platforms. I never did hear from ... Read more
I read about this in Bio-IT World and had to go check it out. It's called the Genome Projector and it has to be the coolest genome browser I've ever seen.
They have 320 bacterial genomes to play with. Naturally, I chose our friend E. coli. The little red pins in the picture below mark the positions of ribosomal RNA genes (It's not perfect, at least one of these genes is a ribosomal RNA methyltransferase and not a 16S ribosomal RNA.) ... Read more
The New England Journal of Medicine published a study yesterday showing that small changes in the DNA in the long arm of chromosome 16 are associated with autism.
I met a teenager with autism last summer, when I attended family night at the Seattle Park and Rec summer camp program for kids with special needs. It's a fantastic program. The kids spend a week or more at summer camp ... Read more
In which we're reminded that database searches are experiments, too.
One of the trickiest things with bioinformatics experiments is repeating them. This challenge isn't related to the validity of the original results, the challenge is that, unless you made your own database and kept it in the same state, the database that you'll be using at a later time, sometimes even a day later, is a different database. And, if you query a different database, you may get a different result.
The series that I'm currently posting is one that I started working on a couple of years ago. ... Read more