I just spent an amazing three days motorbiking round the Ha Giang loop in northern Vietnam. Fantastic thing to do, just mind blowingly amazingly spectacular. However, I had a bit of a stressful time making the connection between my plane arriving into Noi Ba airport and the bus to Ha Giang, but it all worked…

It’s a truth universally acknowledged, that for a research career to flourish you need to publish first author papers. However, like many things concerning scientific publishing, this norm fails the ‘explain it to a non-biologist’ test. Non-biologist: So, how do you get credit for the papers you publish? Biologist: Well, if you are listed first…

I saw this amazing ‘natures-heartbeat‘ cartogram, and thought it would be cool to have something similar for TB incdience. There doesn’t seem to be any TB cartograms already available, so I thought I would make my own. I used the cartogram package in R. After spending some time in the deeper circles of R dependecy…

I’m reading an interesting article which Marc Lipsitch tweeted about. The C-Word: Scientific Euphemisms Do Not Improve Causal Inference From Observational Data by Miguel Hernan. The main take-away messages for me are that Almost all scientific studies are aiming for causal inference, but people working on non-intervention, non-randomised studies (aka association/descriptive/exploratory studies) are generally discouraged from…

Here, in the interests of ‘if you have to email it twice, write a blog’ is my high-level overview of what a bacterial genomics pipeline looks like. 1. quality assess fastqs with e.g. fastqc, visualise these across your dataset with MultiQC. If data is particularly bad, do quality trimming, if not, then don’t. 2. do species…

This post belongs in the ‘write it down before you forget’ category. Edit – this approach is necessary for handling the trees produced by RAxML, but not those produced by IQ-TREE.  Edit #2 – Ancestral state reconstruction in RAxML does not seem to work very well. I’m trying IQ-TREE (v1.6) instead. I have a tree…

Adapted by Lauren Cowley from original PHE training material by Philip Ashton and Tim Dallman Answers at the end Salmonella Enteritidis PT14b outbreak exercise Bioinformatics training, interpretation of phylogenies Prepared by the Gastrointestinal, Emerging and Zoonotic Infections department and the Gastrointestinal Bacteria Reference Unit, Public Health England, Colindale, London.   Aim of Session To develop…

As a promethion looks comparable in startup cost with a MiSeq (though, actually, because the machine is free, you get more sequencing for your buck with the promethion), I wonder how much it would cost to sequence a bacterial genome on the promethion? This post involves a bunch of guesswork, extrapolation and the backs of envelopes,…

Quality Assessment and Trimming Trimmomatic http://www.usadellab.org/cms/index.php?page=trimmomatic Trimmomatic: A flexible trimmer for Illumina Sequence Data. Bolger, A. M., Lohse, M., & Usadel, B. (2014). Bioinformatics, btu170. A flexible read trimming tool that will remove Illumina adapters, reads below a certain length and low quality ends of the read Seqtk https://github.com/lh3/seqtk Tool for processing sequences in the FASTA…

I have recently started using the high performance cluster at the Sanger Institute, and it comes with an interesting quandary. You have to be explicit in the amount of RAM you request when you submit your job (the PHE cluster wasn’t like this). Then, that amount of RAM is assigned to your job and wont…