3333 \vspace {4mm}
3434
3535 % Enter the names of all the authors here
36- {\Large {\em Louis du Plessis}}
36+ {\Large {\em Louis du Plessis and Nicola de Maio }}
3737\end {center }
3838
3939Transmission tree reconstruction with the structured coalescent
@@ -151,6 +151,8 @@ \subsubsection{Python}\label{python}
151151better looking figure.
152152
153153Python should already be installed on most Mac OS X or Linux systems.
154+ Both graphviz and graph-tool are available on Homebrew, and graphviz can
155+ also be installed using \lstinline !apt-get ! on Linux systems.
154156
155157\clearpage
156158
@@ -188,10 +190,10 @@ \subsection{The Data}\label{the-data}
188190contains 11 viral sequences from 10 farms. Four sequences were sampled
189191during the first cluster and a further 7 during the second cluster. In
190192addition, we also have the earliest and latest possible dates during
191- which each farm was infected with the disease (Figure
192- \ref {fig:outbreak }). The data were first analysed in
193- \citep {Cottam2008PlosPath } and later reanalysed using SCOTTI in
194- \citep {deMaio2016 }.
193+ which each farm was infected with the disease, informed by the culling
194+ time and first appearance of symptoms (Figure \ref {fig:outbreak }). The
195+ data were first analysed in \citep {Cottam2008PlosPath } and later
196+ reanalysed using SCOTTI in \citep {deMaio2016 }.
195197
196198\begin {figure }
197199 \centering
@@ -517,18 +519,23 @@ \subsection{Analysing the output in Tracer and
517519
518520This parameter estimates the number of hosts in the outbreak. It is
519521bounded below by 10 (the number of sampled farms) and above by 20, which
520- was our input upper bound. We see that there appears to be significant
521- support for almost twice as many farms to have been infected as farms
522- where diseased animals were found. The parameter
523- \textbf {migModel.popSize } logs the effective population size of the
524- hosts, which is directly proportional to the genetic diversity of the
525- virus within each farm. We see that the effective population size is
526- quite low, which is probably due to the relatively short period of the
527- outbreak. The equal infection rate between farms is logged by
528- \textbf {migModel.rateMig } and the clock rate by \textbf {mutationRate }.
529- If the clock rate seems low for a virus, keep in mind that we measure
530- time in days. Thus, the units for substitutions are in
531- substitutions/site/day instead of the usual substitutions/site/year.
522+ was our input upper bound. However, it is difficult to interpret this
523+ parameter as the number of farms that were infected, because (i) one
524+ non-sampled deme may actually represent a series of hosts with no time
525+ overlap, or a single host with unlimited exposure time (like
526+ environmental contamination); (ii) non-sampled hosts are not necessarily
527+ infected; (iii) many non-sampled hosts might just represent one host
528+ with large population size, like an environmental endemic source.
529+
530+ The parameter \textbf {migModel.popSize } logs the effective population
531+ size of the hosts, which is directly proportional to the genetic
532+ diversity of the virus within each farm. We see that the effective
533+ population size is quite low, which is probably due to the relatively
534+ short period of the outbreak. The equal infection rate between farms is
535+ logged by \textbf {migModel.rateMig } and the clock rate by
536+ \textbf {mutationRate }. If the clock rate seems low for a virus, keep in
537+ mind that we measure time in days. Thus, the units for substitutions are
538+ in substitutions/site/day instead of the usual substitutions/site/year.
532539
533540\begin {framed }
534541Select \textbf {tree.height } (Figure \ref {fig:tmrca })
@@ -542,11 +549,12 @@ \subsection{Analysing the output in Tracer and
542549\end {figure }
543550
544551This parameter is the TMRCA of the sequences included in the
545- transmission tree. The median estimate is 67.36 days. Since the most
546- recent sample was taken on day 62 of the outbreak (IP8-62), this
547- indicates that it is unlikely that the outbreak started more than a week
548- before it was discovered and confirmed, which is an encouraging sign for
549- the surveillance of foot and mouth disease in the United Kingdom.
552+ transmission tree. The median estimate is 67.36 days, with a 95\% HPD
553+ between 60.76 and 78.55 days. Since the most recent sample was taken on
554+ day 62 of the outbreak (IP8-62), this indicates that it is unlikely that
555+ the outbreak started more than a week before it was discovered and
556+ confirmed, which is an encouraging sign for the surveillance of foot and
557+ mouth disease in the United Kingdom.
550558
551559\begin {framed }
552560Open \textbf {TreeAnnotator } and set the \textbf {Burnin percentage } to
@@ -570,9 +578,13 @@ \subsection{Analysing the output in Tracer and
570578\textbf {Colour by } dropdown box select \textbf {host }. Check
571579\textbf {Gradient } and increase the \textbf {Line Weight } to \textbf {5 }.
572580
573- Increase the \textbf {Font Size } under \textbf {Tip Labels }. Check
574- \textbf {Node Labels } and select \textbf {host.prob } from the dropdown box
575- and increase the \textbf {Font size }.
581+ Increase the \textbf {Font Size } under \textbf {Tip Labels } and change
582+ \textbf {Display } to \textbf {host }. Check \textbf {Node Labels } and select
583+ \textbf {host.prob } from the dropdown box and increase the \textbf {Font
584+ size }.
585+
586+ Under \textbf {Node Shape } select \textbf {Circle } and set the size by
587+ \textbf {host.prob } and the colour by \textbf {host }.
576588
577589Check \textbf {Legend } and select \textbf {host } as \textbf {Attribute }.
578590\end {framed }
@@ -622,7 +634,7 @@ \subsection{Constructing the transmission
622634farms. We will use the script
623635\lstinline !Make_transmission_tree_alternative.py !, which uses the
624636\lstinline !graphviz ! package. If this package is not installed you will
625- have to install it, either through homebrew or by installing the
637+ have to install it, either through Homebrew or by installing the
626638Anaconda Python distribution. Alternatively, if you have previously
627639installed the \lstinline !graph-tool ! package you may use the script
628640\lstinline !Make_transmission_tree.py !, which will produce better looking
@@ -654,7 +666,14 @@ \subsection{Constructing the transmission
654666\begin {figure }
655667 \centering
656668 \includegraphics [max width=\textwidth , max height=0.9\textheight ]{figures/FMDV_transmission_direct_transmissions.jpg}
657- \caption {The direct transmission network.}
669+ \caption {The direct transmission network using graphviz.}
670+ \label {fig:hostsets }
671+ \end {figure }
672+
673+ \begin {figure }
674+ \centering
675+ \includegraphics [max width=\textwidth , max height=0.9\textheight ]{figures/FMDV3_out_direct_transmissions.png}
676+ \caption {The direct transmission network using graph-tool.}
658677 \label {fig:hostsets }
659678\end {figure }
660679
@@ -710,7 +729,7 @@ \section{Useful Links}\label{useful-links}
710729% Please do not change the license
711730% Add the author names and relevant links
712731% Add any other aknowledgments here
713- \href {http://creativecommons.org/licenses/by/4.0/}{\includegraphics [scale=0.8]{figures/ccby.pdf}} This tutorial was written by Louis du Plessis for \href {https://taming-the-beast.github.io}{Taming the BEAST} and is licensed under a \href {http://creativecommons.org/licenses/by/4.0/}{Creative Commons Attribution 4.0 International License}.
732+ \href {http://creativecommons.org/licenses/by/4.0/}{\includegraphics [scale=0.8]{figures/ccby.pdf}} This tutorial was written by Louis du Plessis and Nicola de Maio for \href {https://taming-the-beast.github.io}{Taming the BEAST} and is licensed under a \href {http://creativecommons.org/licenses/by/4.0/}{Creative Commons Attribution 4.0 International License}.
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