If we had experienced (through the social distancing and other precautionary measures) and continue to experience a doubling period of 5 days (not on the chart but a possible input to my spreadsheet), it would lead to 25,000 cases after 40 days.
If we had managed to experience 7 days for doubling of cases (as Japan and Singapore seem to have done), then we would have seen 5000 cases at 40 days (but that’s where we are already, so too late for that outcome).
So the outcomes are VERY sensitively dependent on the doubling period, which I’m sure in turn is VERY dependent on the average number of people each carrier infects.
I haven’t modelled that part yet, but, again, assumptions apart, the doubling period would be an outcome of that number, together with how long cases last (before death or recovery) and whether re-infection is possible, likely or frequent. It all gets a bit more difficult to be predictive, rather than mathematically expressing known data.
On a more positive note, there is a report today of the statistical work of Michael Levitt (a proper statistician!), who predicted on February 21st, with uncanny accuracy, the March 23rd situation in China (improvements compared with the then gloomy other forecasts). See the article attached.
A few people might have see the Johns Hopkins University Medical School chart on Covid-19 infection rates in different countries. This particular chart (they have produced many different outputs, some of them interactive world incidence models – see https://coronavirus.jhu.edu/map.html for more) usefully compares some various national growth rates with straight lines representing different periods over which the number of cases might double – 1 day, 2 days, 3 days and 7 days. It’s a kind of log chart to base 2.
I’ve been beginning to simulate the outcomes for 2 input data items:
your chosen number of days (x) since the outbreak (defined at 100 cases on day zero to give a base of calculation);
your chosen rate of growth of cases, expressed by an assumed number of days for doubling the cases number (z), and then;
the output, the number of cases (y) on day x.
This spreadsheet allows you , in the last columns, to enter x and z in order to see the outcome, y.
Of course this is only an output model, it knows nothing about the veracity of assumptions – but the numbers (y) get VERY large for small doubling periods (z).
Here’s the kind of stuff that the Covid-19 modellers will be doing. https://www.nature.com/articles/srep46076.pdf I have downloaded GleamViz, http://www.gleamviz.org/simulator/client/, and it is quite complicated to set up (I used to have a little Windows app called Wildfire that just needed a few numbers to get a pictorial progression of life/recovery/death from the disease, depending on infectivity, time taken to kill, etc). GLEAMviz15 is a proper tool* that needs a lot of base data to be defined. I’m thinking about it! PS – Some of the GleamViz team seem to be based in Turin. *see my comment to this post.
Such modelling reminds me of event-based simulation models I used to develop for the MoD back in the 70s, using purpose-designed programming languages such as Simscript (Fortran-like) and Simula (Algol-like), all based around what today might be called object oriented programs (OOP), where small modules of code represent micro-events that occur, having inputs that trigger them from previous (or influencing) events, and outputs that trigger subsequent (or influenced) events, all inputs and outputs coded with a probability distribution of occurrence. In the MoD case this was about – erm, what am I allowed to say! – reliability and failure rates in aircraft, refuelling tankers and cruise missiles (even then). I recall that in my opening program statement, I named it “PlayGod”. I did ask for a copy of it years later (it’s all in very large dusty decks of Hollerith cards somewhere (I did overlap with paper tape, but I was a forward looking person!)) but they refused. Obviously far too valuable to the nation (even if I wasn’t, judging by my salary).
With regard to the publication of the modelling tools, I’ll leave aside the data part of it…there is a lot, and much of it will be fuzzy, and I’m sure is very different for every country’s population, depending where they are with the disease, and what measures they have taken over a period and whether, for example, they had “super-spreaders” early on, as some countries did.
Back in the early seventies, a European macro-economic project led to the publication of a book, The Limits to Growth. The context is described in https://en.m.wikipedia.org/wiki/The_Limits_to_Growth Not long after, our Government released the macro-economic model software they were using to explore these aspects of the performance and the future of our economy in a worldwide scenario. I worked at London University’s commercial unit for a while, and we mounted this freely available Government model, and offered it to all-comers.
The Economist publication was one of our clients for this, and their chief economics journalist, Peter Riddell, was someone we met several times in connection with it. He was very interested in modelling different approaches (to matters such as exchange rates, money availability (monetary and fiscal policy) and their impact on economic development in a constrained environment) and report on them, as a comparison with the Government’s own modelling, policies and strategies.
This was all at a time when the Economy was perceived to be at risk (as it is now from this pandemic), and inflation and exchange rates, monetary and fiscal policy (for example) were very much seen as determinants of our welfare as a nation, and for all other nations, including the emerging European Community, who originally sponsored this work.
We seem to be in a very similar situation with regard to the modelling of this Covid-19 pandemic, and I don’t see why the software being used (at least by the UK Government’s analysts (probably academics, I think Sir Patrick Vallance said in his answers to the Select Committee this morning)) could not be released so that we might get a better understanding of the links assumed between actions and outcomes, impact of assumptions made, and the impact of actual and potential measures (and their feedback loops, positive or negative) taken in response to the outbreak. Apparently the Government IS going to release its modelling, and I would certainly be interested to see it – its parameters, assumptions, its logic and its variety of outcomes and dependencies on assumptions. The possible outcomes are probably EXACTLY why the Government hasn’t released it yet.
This video is about skiing in Breckenridge during our vacation at New Year 2003-4.
We had been skiing in Breckenridge since the early 90s. Once our boys Harry & Tom discovered firstly Whistler, and then Breckenridge, we couldn’t persuade them to go back to skiing in Europe as we had for many years!
On our first trip there we met Dutch van Andel, our ski instructor, and spent many happy days out with him, a most effective way of taking ski lessons over a day as a family instead of individual or on large groups – a happy medium!
Dutch and his sons, Hayden and Gerhard, became firm friends of ours, and more recently, when Dutch had moved back to the Netherlands and we had resumed skiing in Europe, we had a great ski trip together in Bormio (a feature video yet to come!)
Meanwhile, here is a video taken by the ski school on one of our days out with Dutch, when he took us to the Nastar slalom course as part of our – erm – training!
Here is another video taken by the ski school on one of our days out with Dutch, at New Year 2005, with a colleague, Mike, from the ski school, following us and catching the magic moments!
In January 2008, we spent a week skiing in Courmayeur, a smaller Italian resort, following Zermatt the year before and St Anton the year after. Courmayeur lost nothing by comparison, and as you will see below, we enjoyed the wonderful snow conditions and varied terrain, including off-piste and tree skiing, enormously.
The first video is about a day at Courmayeur, 15th Jan 2008, when fresh overnight snow left several runs in beautiful condition for deep snow skiing. Here are Harry and Tom, and their poor old cameraman, trying their hand at several of them.
Lunch at Maison Vieille was a real treat, the best of the mountain restaurants, and we went there a few times during the week. Amazingly there was no queuing for lunch, although it was busy enough, and we couldn’t wait to go back.
This is not the largest resort we have been to by any means, but in our time there, in January, there were so many excellent runs in wonderful snow conditions, and good weather nearly all of the time. We would go back there like a shot – but there are so many European resorts we want to revisit after so may years skiing in Breckenridge, Colorado.
While the boys were young, they wouldn’t let us ski anywhere else owing to the familiar food and language in the US, and of course we had wonderful times with our instructor, Dutch van Andel, and his two boys, Hayden and Gerhard, who all became firm friends, and hosted us for Christmases as well! Dutch joined us in Bormio, in 2014, on one of our more recent European expeditions. More of that in another post…
A second day of equally lovely snow conditions! Harry and I were the early starters, but we soon called Tom up the mountain to enjoy the wonderful snow conditions.
The next day, 17th January, we went off-piste skiing again in Courmayeur, when more fresh overnight snow left several runs in beautiful condition for deep snow skiing. We decided to use the Mont Blanc guides, to help us find some new runs and some tree skiing. It was quite difficult here and there, as you will see!
All of us, Ann, Harry and Tom and I spent the day with Enrico Bonino, of Mont Blanc Guides (and an experienced climber) and it was quite an education!
This video is about my 2018 Prudential RideLondon 100, riding for Marie Curie (as I did again a year later in 2019) in memory of my mother-in-law Laura, and in thanks for the help Marie Curie gave her and us during her final illness. I’ll be supporting Marie Curie again this year, 2020, even though I have my own entry.
It was pretty poor weather, much worse than usual, starting to rain at or near the start, and not stopping until around Dorking; and it was also pretty cold as a result, so much so that I refused a couple of stops, having shivered at the two where I did stop. I also had a puncture at a faster part of the course at Putney Heath, and also after I finished. The Continental guys at the finish were great, and together we found a hidden tiny speck of glass, neither visible or tangible from outside or inside the tyre, so all was well for my ride home, with no repeat of the puncture!
Overall, though it was a great experience, and my first attempt at the Prudential, and together with the Saturday Freeride (also shown in the pictures) the whole weekend was the usual fulfilling, enjoyable and well-organised experience, especially with my riding buddy, Leslie, who has done the Prudential many times, and whom I joined up with at the end.
I look forward to riding with Marie Curie again at the 2020 edition on August 16th.
Here is a short extract video, just covering the section between Leith Hill and Box Hill
This video is about the 6Points cycling trip to Ibiza on 6th Oct 2019. It’s is a more detailed record of our visit than my previous shorter video, and includes GoPro clips from my bike, as well as photos taken along the way.
Our ride comprised 140 kms or so of cycling, with about 1700m of climbing, and all of us on the ride agreed that it was another great day out, following our 6Points ride in Formentera the previous day.
Ibiza is the third largest of the Balearic Islands, an autonomous community of Spain. Its largest settlements are Ibiza Town (Catalan: Vila d’Eivissa, or simply Vila), Santa Eulària des Riu, and Sant Antoni de Portmany. Its highest point, called Sa Talaiassa (or Sa Talaia), is 475 metres (1,558 feet) above sea level; we visited Sant Josep de sa Talaia, as our highest point early in the ride.
Ibiza has become well known for its association with nightlife, electronic dance music, and for the summer club scene, all of which attract large numbers of tourists drawn to that type of holiday. David Guetta, whose music provides the background to this video, has DJ’d in Ibiza, back in the party days!
By visiting the north, east, south and western compass points of the island, as well as the highest point, and the (sea level!) beach at Portinatx, we saw most of the island from several viewpoints.
The steepest part of the ride, the climb out of Portinatx, after lunch, was memorable!
I’m already looking forward to my next visit.
A shorter video of the same ride, but with no GoPro footage
This video is about the 6Points cycling trip to Formentera on 5th Oct 2019. It’s is a more detailed record of our visit than my previous shorter video, and includes GoPro clips from my bike, as well as photos taken along the way.
Although it was only 70kms or so of cycling, and not very hilly, all of us on the ride agreed that it was a great day out. By visiting the north, east, south and western compass points of the island, as well as the highest point, and dipping our bikes in the sea to recognise the lowest altitude of our ride, we saw most of the island from several viewpoints.
I discovered, while putting the video together, that at least two of the lighthouses at compass point locations, Far de La Mola in the east and , and Far de Barbaria in the south, have some interesting claims to fame, as well as Formentera itself having something of a “hippie” reputation. I knew that Ibiza is regarded by some as a “clubbing” island (video in preparation!) but I didn’t know of Formentera’s background.
Next to the Far de La Mola lighthouse is a 1978 monument in honour of the writer Jules Verne’s birth in 1828, for the mention of it he makes in his book “Hector Servadac (travels and adventures through the solar system)”.
The lighthouse at Cap de Barbaria, the southernmost point of Formentera, is the setting for the film “Lucía y el sexo” (Sex and Lucía) by director Julio Medem.
Our tip to the easternmost point at Can Marroig took us through the Ses Salines natural reserve, land acquired from the owners of the farm and properties there, once home to vineyards set up after the disruption of French vineyards caused by phylloxera plague. And back in the day, the original hippie crowd, such as Bob Dylan and Janis Joplin, came here in the ’60s.
I have put together more of my GoPro video of Sobremunt, exploring the summit area in more detail, which can be quite hard to find amongst the various private estates up there, one of which IS Sobremunt. This was part of the wider circuit I did, reported previously.
I have recently seen three examples of duplicate rides on Strava, owing to the rider recording the ride both on s conventional Garmin, and also on a wristwatch device.
Usually, Strava normally doesn’t allow duplicate rides. I thin, however, there is a logical gap in their thinking – each ride has a unique serial number, and if Strava sees the same serial number it won’t accept it again.
But the same ride on two DIFFERENT devices will have, I’m sure, two different serial numbers so Strava accepts it. It doesn’t make its judgement, it seems, on the CONTENT of the ride (time and location coordinates) which would be harder to program – so i guess they haven’t bothered.
Strava used to have a restriction on when pictures could be uploaded to a ride, on the basis of some misplaced strategy to make sure people didn’t forge ride pictures!!
But it seems they haven’t even got the basics right!! They obviously need some consultancy on this…see my previous article at www.briansutton.uk on merging rides for a bit (lot) more in this kind of area.
Suffice to say that when merging two rides (recorded in two successive parts on two different devices owing to battery life issues) you have to randomise the serial number of the merged ride. Otherwise it inherits the serial number of one of the component part rides, and won’t upload because Strava spots the duplicate serial number.