diff --git a/inst/app/www/content/about.md b/inst/app/www/content/about.md index bf3bbf4..731e728 100644 --- a/inst/app/www/content/about.md +++ b/inst/app/www/content/about.md @@ -1 +1,97 @@ -This is a page containing some information about the project. +# tfpbrowser + +## About + +The Transmission Fitness Polymorphism Browser (tfpbrowser) is a visualisation tool for output from +the Transmission Fitness Polymorphism Scanner (tfpscanner)[1-3]. Information on the visualisation +options can be found below, while details regarding installation of the tfpbrowser package and the +source code can be found at +[https://github.com/mrc-ide/tfpbrowser](https://github.com/mrc-ide/tfpbrowser). + +Six different visualisations can be accessed by selecting from the ‘View’ dropdown menu on the +left-hand side. If the ‘View’ option is not visible, then the left-hand side menu may need to be +expanded by clicking on the double arrow button. + +### Tree Visualisations + +There are four different tree visualisation options. These are described below, but a number of +characteristics are common to each tree visualisation: + +- The size of the circles (for internal nodes) and triangles (tips) indicates the size of the +cluster that they represent. +- The colour indicates a particular characteristic of the cluster. +- On the right-hand side of each tree visualisation, the colouring of the bars indicates whether a +genotype (for which a key mutation is labelled) is present (true) or absent (false) in the clusters +at the same vertical level. +- Further information on each cluster can be viewed by hovering over it with the mouse cursor. + +The four tree visualisation options in the ‘View’ menu are: + +#### Tree Clock Outlier + +Displays a phylogenetic tree with clusters colour coded (key at the top) according to the value of +the molecular clock outlier (MCO) statistic. This is computed by the tfpscanner as a measure of the +degree to which evolutionary rates differed in the lineage leading to a phylogenetic cluster. +Root-to-tip regression is used to predict the divergence of tips in a cluster and contrasts this +with divergence within an ancestral clade including the given cluster. This predicted divergence is +then compared to the true divergence of the cluster. + +#### Tree Logistic Growth Rate + +Displays a phylogenetic tree with clusters colour coded (key at the top) according to the value of +the logistic growth rate. This is computed in the tfpscanner using one of two different methods +depending on the level of model support calculated using the Akaike Information Criterion (AIC) and +‘relative likelihood’. The first method uses a generalised linear model (GLM) to calculate the log +odds of a sample being from a cluster of interest compared to a geographically and temporally +matched sample weighted by prevalence, and multiplied by the estimated mean generation time to +calculate the relative LGR per generation for each cluster of interest. The second method uses a +generalised additive model (GAM) combined with a Gaussian process model to identify changes in +growth rates over time. + +#### Tree Mutations + +This visualisation has a ‘Mutation’ menu from which to select a particular mutation to be +highlighted in the phylogenetic tree. Clusters containing the mutation selected will be coloured red +in the phylogenetic tree while clusters not containing this mutation will be grey. + +#### Tree Sequences + +This visualisation has a ‘Sequence’ menu from which to select a particular sequence ID. Clusters +containing this sequence will be coloured red in the phylogenetic tree while those not containing it +will be grey. + +### Scatter plots + +The molecular clock outlier and logistic growth rate statistics can also be viewed in scatter plots: + +#### Sina Clock Outlier + +Displays a scatter plot of the molecular clock outlier statistic value for each phylogenetic cluster +on the y-axis and the lineage and/or mutation is stratified along the x-axis. The plot marker +colours indicate the lineage and/or mutation and the size indicates the cluster size, both as per +the legend on the right-hand side of the plot. _See ‘Tree Clock Outlier’ above for details of the +molecular clock outlier statistic_. + +#### Sina Logistic Growth Rate + +Displays a scatter plot of the logistic growth rate value for each phylogenetic cluster on the +y-axis and the lineage and/or mutation is stratified along the x-axis. The circle colours indicate +the lineage and/or mutation and the size indicates the cluster size, both as per the legend on the +right-hand side of the plot. _See ‘Tree Logistic Growth Rate’ above for details of this statistic_. + +### Downloads + +Tables, plots and .rds files can also be downloaded by clicking on the ‘Cluster statistics’ tab and +selecting the relevant option. + +### References + +[1] Volz EM, Boyd O. Transmission Fitness Polymorphism Scanner. Available from: +https://github.com/mrc-ide/tfpscanner + +[2] Volz EM. Fitness, growth and transmissibility of SARS-CoV-2 genetic variants. Nat Rev Genet +2023. https://doi.org/10.1038/s41576-023-00610-z + +[3] Drake KO, Boyd O, Franceschi VB, Colquhoun RM, Ellaby NAF, Volz EM. Phylogenomic early warning +signals for SARS-CoV-2 epidemic waves. eBioMedicine 2024: 100. +https://doi.org/10.1016/j.ebiom.2023.104939