Posts filed under General (2814)

January 1, 2025

Black spatulas

If you’ve been paying attention to the food scare news, you will have heard that black plastic spatulas are EVIL and then that they are probably ok.  Predicted exposures to brominated flame retardants were close to the ‘reference level’ because of a simple decimal-place error and there’s now a ten-fold safety margin. The summary by Joel Schwarcz at McGill University in Canada is good; as he notes, there is no actual need for spatulas to be flame-retardant and while the level of fire retardants doesn’t look dangerous, the target level should be roughly zero.

There are two additional points I want to make. First, units.  The original scare paper quoted the ‘oral reference dose’ as 7000 nanograms per kg per day. The EPA document that it cited said 0.007 mg per kilogram per day. These are terrible units.  The SI system gives us names every three orders of magnitude precisely so we don’t have to do this sort of thing and can say 7 micrograms per kilogram per day. It’s a lot easier to work with numbers like this.

Second, what does the reference dose mean?  If you look at the relevant EPA document you will see that the 7 micrograms per kilogram per day comes by taking a reference dose for non-cancer effects in mice and multiplying dividing it by 10 because humans might be more sensitive than mice, and a further 10 because you might be more sensitive than the typical human and a further 3 because long-term exposure might matter more than short-term exposure.  And, on reading further, that the dose for mice was the highest dose tested in that experiment and did not show any adverse effects.  So, the 7 micrograms per kilogram per day reference dose is 300 times the highest dose they even tested for mice.  Some other experiments did find adverse effects in rats, but at doses nearly a thousand times higher: 6 milligrams per kg per day.

Taking all this together you can see the fuzziness in the calculations. There’s now a ten-fold margin of safety between a generously estimated dose and a reference dose — which is not a danger dose, but one that should have no effect.  On top of that, there’s an unknown (and possibly large) safety factor because of the choice of doses in the mouse safety experiments.  The basic problem is that you can’t tell accurately what doses will cause harm in humans without causing harm in humans; some sort of extrapolation is unavoidable in safety assessment.

Away with the ferries

The Isle of Arran, as I’m sure you all know, is on the west side of Scotland  Being an island, it has somewhat limited means of access: Caledonian MacBrayne run two ferries from the mainland.  These ferries are being replaced with allegedly better ferries. However, the BBC headline said ‘Green’ ferry emits more CO2 than old diesel ship

In reply, “Ferries procurement agency CMAL, which owns the ship, said the comparison was “inaccurate” as Glen Sannox is a larger vessel.” 

While New Zealand is very attached to per capita representations of everything, sometimes they aren’t helpful.  The new ship is bigger. Precisely for that reason, it would emit more CO2 if run on the same fuel as the old ship.  The plan is actually to run the ship on liquified fossil gas imported from Qatar and trucked up from the south of England. This would reduce the CO2 emissions, but would produce methane emissions that pretty much compensate for the reduction — and the UK follows mainstream science in recognising that methane actually matters.

In some settings, such as comparing Auckland’s double-decker buses to traditional buses, it’s important to take account of the fact that they’re bigger and so you don’t need as many of them to carry all your passengers.  But when you’re talking about a ferry route with two ships there isn’t the same room for per capita savings to pay off the larger per-ship emissions.   If you run the same number of trips with bigger ships you’ll get more emissions. And if you can carry more cars on the bigger ferries that’s not really going to reduce emissions, either.

December 24, 2024

United Rugby Championship Predictions for Week 9

Team Ratings for Week 9

This is the promised update after the Dragons v Cardiff Rugby game.

The basic method is described on my Department home page.
Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Current Rating Rating at Season Start Difference
Leinster 13.77 12.09 1.70
Glasgow 10.58 9.39 1.20
Bulls 8.19 8.83 -0.60
Munster 5.20 9.28 -4.10
Stormers 5.15 6.75 -1.60
Lions 4.43 6.73 -2.30
Ulster 1.96 2.52 -0.60
Edinburgh 1.77 0.09 1.70
Cheetahs 0.80 0.80 0.00
Sharks -0.41 -2.94 2.50
Connacht -0.89 -0.76 -0.10
Benetton -2.72 1.02 -3.70
Ospreys -5.00 -2.51 -2.50
Scarlets -5.08 -10.65 5.60
Cardiff Rugby -5.92 -2.55 -3.40
Southern Kings -6.52 -6.52 0.00
Zebre -12.07 -16.17 4.10
Dragons -13.24 -15.41 2.20

 

Performance So Far

So far there have been 62 matches played, 46 of which were correctly predicted, a success rate of 74.2%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Stormers vs. Lions Dec 21 29 – 10 0.60 TRUE
2 Benetton vs. Zebre Dec 22 11 – 10 13.80 TRUE
3 Leinster vs. Connacht Dec 22 20 – 12 18.80 TRUE
4 Ulster vs. Munster Dec 22 19 – 22 -0.10 TRUE
5 Sharks vs. Bulls Dec 22 20 – 17 -7.80 FALSE
6 Ospreys vs. Scarlets Dec 22 23 – 22 3.00 TRUE
7 Glasgow vs. Edinburgh Dec 23 33 – 14 9.10 TRUE
8 Dragons vs. Cardiff Rugby Dec 27 22 – 24 -5.60 TRUE

 

Predictions for Week 9

Here are the predictions for Week 9. The prediction is my estimated expected points difference with a positive margin being a win to the home team, and a negative margin a win to the away team.

Game Date Winner Prediction
1 Bulls vs. Lions Dec 29 Bulls 6.30
2 Stormers vs. Sharks Dec 29 Stormers 8.10
3 Connacht vs. Ulster Dec 30 Ulster -0.40
4 Munster vs. Leinster Dec 30 Leinster -6.10
5 Edinburgh vs. Glasgow Dec 30 Glasgow -6.30
6 Zebre vs. Benetton Dec 30 Benetton -6.90
7 Cardiff Rugby vs. Ospreys Jan 02 Cardiff Rugby 1.60
8 Scarlets vs. Dragons Jan 02 Scarlets 10.70

 

Top 14 Predictions for Round 13

Team Ratings for Round 13

The basic method is described on my Department home page.
Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Current Rating Rating at Season Start Difference
Stade Toulousain 10.88 8.76 2.10
Bordeaux Begles 5.74 3.96 1.80
Toulon 5.69 5.32 0.40
Stade Rochelais 3.68 4.85 -1.20
Racing 92 1.86 2.75 -0.90
Clermont 1.70 0.41 1.30
Montpellier 0.71 -0.96 1.70
Bayonne 0.58 -1.69 2.30
Stade Francais -0.09 1.86 -2.00
Castres Olympique -0.46 -0.09 -0.40
Section Paloise -1.07 1.38 -2.50
Lyon -1.17 -0.18 -1.00
USA Perpignan -3.64 -0.66 -3.00
Vannes -8.67 -10.00 1.30

 

Performance So Far

So far there have been 84 matches played, 66 of which were correctly predicted, a success rate of 78.6%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Castres Olympique vs. Bordeaux Begles Dec 22 3 – 13 0.10 FALSE
2 Montpellier vs. Racing 92 Dec 22 21 – 17 4.20 TRUE
3 Stade Francais vs. USA Perpignan Dec 22 24 – 7 8.90 TRUE
4 Stade Rochelais vs. Clermont Dec 22 20 – 15 9.50 TRUE
5 Toulon vs. Section Paloise Dec 22 56 – 25 10.20 TRUE
6 Vannes vs. Bayonne Dec 22 21 – 27 -2.40 TRUE
7 Lyon vs. Stade Toulousain Dec 23 17 – 17 -5.00 FALSE

 

Predictions for Round 13

Here are the predictions for Round 13. The prediction is my estimated expected points difference with a positive margin being a win to the home team, and a negative margin a win to the away team.

Game Date Winner Prediction
1 Bayonne vs. Castres Olympique Dec 29 Bayonne 8.60
2 Bordeaux Begles vs. Toulon Dec 29 Bordeaux Begles 7.50
3 Clermont vs. Montpellier Dec 29 Clermont 7.30
4 Section Paloise vs. Vannes Dec 29 Section Paloise 14.70
5 Racing 92 vs. Lyon Dec 30 Racing 92 9.60
6 Stade Toulousain vs. Stade Francais Dec 30 Stade Toulousain 16.60
7 USA Perpignan vs. Stade Rochelais Dec 30 USA Perpignan 0.10

 

Rugby Premiership Predictions for Round 9

Team Ratings for Round 9

The basic method is described on my Department home page.
Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Current Rating Rating at Season Start Difference
Bristol 13.43 9.58 3.80
Bath 8.63 5.55 3.10
Saracens 6.19 9.68 -3.50
Northampton Saints 2.59 7.50 -4.90
Leicester Tigers 1.21 3.27 -2.10
Sale Sharks 1.10 4.73 -3.60
Gloucester -0.89 -9.04 8.10
Harlequins -1.33 -2.73 1.40
Exeter Chiefs -2.96 1.23 -4.20
Newcastle Falcons -17.22 -19.02 1.80

 

Performance So Far

So far there have been 40 matches played, 26 of which were correctly predicted, a success rate of 65%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Gloucester vs. Harlequins Dec 21 14 – 0 5.20 TRUE
2 Leicester Tigers vs. Bristol Dec 22 24 – 54 0.30 FALSE
3 Newcastle Falcons vs. Bath Dec 22 15 – 40 -17.90 TRUE
4 Sale Sharks vs. Exeter Chiefs Dec 22 28 – 10 8.70 TRUE
5 Saracens vs. Northampton Saints Dec 23 39 – 24 8.90 TRUE

 

Predictions for Round 9

Here are the predictions for Round 9. The prediction is my estimated expected points difference with a positive margin being a win to the home team, and a negative margin a win to the away team.

Game Date Winner Prediction
1 Bristol vs. Sale Sharks Dec 28 Bristol 18.80
2 Bath vs. Saracens Dec 29 Bath 8.90
3 Northampton Saints vs. Newcastle Falcons Dec 29 Northampton Saints 26.30
4 Harlequins vs. Leicester Tigers Dec 29 Harlequins 4.00
5 Exeter Chiefs vs. Gloucester Dec 30 Exeter Chiefs 4.40

 

December 3, 2024

United Rugby Championship Predictions for Week 8

Team Ratings for Week 8

The basic method is described on my Department home page.
Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

 

Current Rating Rating at Season Start Difference
Leinster 14.61 12.09 2.50
Glasgow 9.50 9.39 0.10
Bulls 9.01 8.83 0.20
Lions 5.74 6.73 -1.00
Munster 4.88 9.28 -4.40
Stormers 3.84 6.75 -2.90
Edinburgh 2.85 0.09 2.80
Ulster 2.28 2.52 -0.20
Cheetahs 0.80 0.80 0.00
Sharks -1.24 -2.94 1.70
Connacht -1.72 -0.76 -1.00
Benetton -1.76 1.02 -2.80
Ospreys -4.78 -2.51 -2.30
Scarlets -5.30 -10.65 5.30
Cardiff Rugby -5.52 -2.55 -3.00
Southern Kings -6.52 -6.52 0.00
Zebre -13.03 -16.17 3.10
Dragons -13.64 -15.41 1.80

 

Performance So Far

So far there have been 54 matches played, 39 of which were correctly predicted, a success rate of 72.2%.
Here are the predictions for last week’s games.

 

Game Date Score Prediction Correct
1 Glasgow vs. Scarlets Nov 30 17 – 15 23.30 TRUE
2 Ulster vs. Leinster Nov 30 20 – 27 -10.60 TRUE
3 Sharks vs. Stormers Dec 01 21 – 15 -4.20 FALSE
4 Cardiff Rugby vs. Dragons Dec 01 31 – 23 11.40 TRUE
5 Connacht vs. Bulls Dec 01 14 – 28 -3.60 TRUE
6 Edinburgh vs. Benetton Dec 01 50 – 33 8.20 TRUE
7 Munster vs. Lions Dec 01 17 – 10 4.00 TRUE
8 Zebre vs. Ospreys Dec 01 22 – 17 -4.90 FALSE

 

Predictions for Week 8

Here are the predictions for Week 8. The prediction is my estimated expected points difference with a positive margin being a win to the home team, and a negative margin a win to the away team.

 

Game Date Winner Prediction
1 Stormers vs. Lions Dec 21 Stormers 0.60
2 Benetton vs. Zebre Dec 22 Benetton 13.80
3 Leinster vs. Connacht Dec 22 Leinster 18.80
4 Ulster vs. Munster Dec 22 Munster -0.10
5 Sharks vs. Bulls Dec 22 Bulls -7.80
6 Ospreys vs. Scarlets Dec 22 Ospreys 3.00
7 Glasgow vs. Edinburgh Dec 23 Glasgow 9.10
8 Dragons vs. Cardiff Rugby Dec 27 Cardiff Rugby -5.60

 

Top 14 Predictions for Round 12

Team Ratings for Round 12

The basic method is described on my Department home page.
Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Current Rating Rating at Season Start Difference
Stade Toulousain 11.20 8.76 2.40
Bordeaux Begles 5.39 3.96 1.40
Toulon 4.96 5.32 -0.40
Stade Rochelais 3.91 4.85 -0.90
Racing 92 1.84 2.75 -0.90
Clermont 1.45 0.41 1.00
Montpellier 0.70 -0.96 1.70
Bayonne 0.34 -1.69 2.00
Castres Olympique -0.06 -0.09 0.00
Section Paloise -0.33 1.38 -1.70
Stade Francais -0.41 1.86 -2.30
Lyon -1.43 -0.18 -1.30
USA Perpignan -3.32 -0.66 -2.70
Vannes -8.52 -10.00 1.50

 

Performance So Far

So far there have been 77 matches played, 61 of which were correctly predicted, a success rate of 79.2%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Bordeaux Begles vs. Montpellier Dec 01 9 – 6 13.00 TRUE
2 Clermont vs. Castres Olympique Dec 01 54 – 10 5.00 TRUE
3 Racing 92 vs. Stade Toulousain Dec 01 17 – 21 -1.30 TRUE
4 Section Paloise vs. Lyon Dec 01 29 – 15 7.40 TRUE
5 Stade Rochelais vs. Vannes Dec 01 14 – 23 20.30 FALSE
6 USA Perpignan vs. Toulon Dec 01 13 – 22 0.20 FALSE
7 Bayonne vs. Stade Francais Dec 02 21 – 13 7.50 TRUE

 

Predictions for Round 12

Here are the predictions for Round 12. The prediction is my estimated expected points difference with a positive margin being a win to the home team, and a negative margin a win to the away team.

Game Date Winner Prediction
1 Castres Olympique vs. Bordeaux Begles Dec 22 Castres Olympique 0.10
2 Montpellier vs. Racing 92 Dec 22 Montpellier 4.20
3 Stade Francais vs. USA Perpignan Dec 22 Stade Francais 8.90
4 Stade Rochelais vs. Clermont Dec 22 Stade Rochelais 9.50
5 Toulon vs. Section Paloise Dec 22 Toulon 10.20
6 Vannes vs. Bayonne Dec 22 Bayonne -2.40
7 Lyon vs. Stade Toulousain Dec 23 Stade Toulousain -5.00

 

Rugby Premiership Predictions for Round 8

Team Ratings for Round 8

The basic method is described on my Department home page.
Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Current Rating Rating at Season Start Difference
Bristol 10.40 9.58 0.80
Bath 7.92 5.55 2.40
Saracens 5.58 9.68 -4.10
Leicester Tigers 4.25 3.27 1.00
Northampton Saints 3.20 7.50 -4.30
Sale Sharks 0.16 4.73 -4.60
Harlequins -0.45 -2.73 2.30
Gloucester -1.77 -9.04 7.30
Exeter Chiefs -2.02 1.23 -3.20
Newcastle Falcons -16.51 -19.02 2.50

 

Performance So Far

So far there have been 35 matches played, 22 of which were correctly predicted, a success rate of 62.9%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Harlequins vs. Bristol Nov 30 24 – 48 0.60 FALSE
2 Newcastle Falcons vs. Saracens Nov 30 17 – 12 -20.70 FALSE
3 Northampton Saints vs. Gloucester Dec 01 17 – 25 16.30 FALSE
4 Bath vs. Exeter Chiefs Dec 01 19 – 15 19.60 TRUE
5 Sale Sharks vs. Leicester Tigers Dec 02 39 – 25 -0.50 FALSE

 

Predictions for Round 8

Here are the predictions for Round 8. The prediction is my estimated expected points difference with a positive margin being a win to the home team, and a negative margin a win to the away team.

Game Date Winner Prediction
1 Gloucester vs. Harlequins Dec 21 Gloucester 5.20
2 Leicester Tigers vs. Bristol Dec 22 Leicester Tigers 0.30
3 Newcastle Falcons vs. Bath Dec 22 Bath -17.90
4 Sale Sharks vs. Exeter Chiefs Dec 22 Sale Sharks 8.70
5 Saracens vs. Northampton Saints Dec 23 Saracens 8.90

 

November 25, 2024

Top 14 Predictions for Round 11

Team Ratings for Round 11

The basic method is described on my Department home page.
Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Current Rating Rating at Season Start Difference
Stade Toulousain 11.05 8.76 2.30
Bordeaux Begles 5.76 3.96 1.80
Stade Rochelais 4.93 4.85 0.10
Toulon 4.58 5.32 -0.70
Racing 92 2.00 2.75 -0.80
Castres Olympique 1.25 -0.09 1.30
Bayonne 0.30 -1.69 2.00
Montpellier 0.28 -0.96 1.20
Clermont 0.18 0.41 -0.20
Stade Francais -0.33 1.86 -2.20
Section Paloise -0.71 1.38 -2.10
Lyon -1.10 -0.18 -0.90
USA Perpignan -2.95 -0.66 -2.30
Vannes -9.50 -10.00 0.50

 

Performance So Far

So far there have been 70 matches played, 56 of which were correctly predicted, a success rate of 80%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Castres Olympique vs. Stade Rochelais Nov 24 28 – 24 2.30 TRUE
2 Lyon vs. Clermont Nov 24 22 – 30 6.70 FALSE
3 Montpellier vs. Section Paloise Nov 24 30 – 3 5.80 TRUE
4 Stade Francais vs. Racing 92 Nov 24 40 – 24 3.10 TRUE
5 Stade Toulousain vs. USA Perpignan Nov 25 41 – 9 19.30 TRUE
6 Toulon vs. Bayonne Nov 24 39 – 19 9.90 TRUE
7 Vannes vs. Bordeaux Begles Nov 24 29 – 37 -8.90 TRUE

 

Predictions for Round 11

Here are the predictions for Round 11. The prediction is my estimated expected points difference with a positive margin being a win to the home team, and a negative margin a win to the away team.

Game Date Winner Prediction
1 Bordeaux Begles vs. Montpellier Dec 01 Bordeaux Begles 13.00
2 Clermont vs. Castres Olympique Dec 01 Clermont 5.00
3 Racing 92 vs. Stade Toulousain Dec 01 Stade Toulousain -1.30
4 Section Paloise vs. Lyon Dec 01 Section Paloise 7.40
5 Stade Rochelais vs. Vannes Dec 01 Stade Rochelais 20.30
6 USA Perpignan vs. Toulon Dec 01 USA Perpignan 0.20
7 Bayonne vs. Stade Francais Dec 02 Bayonne 7.50

 

November 4, 2024

Top 14 Predictions for Round 10

Team Ratings for Round 10

The basic method is described on my Department home page.
Here are the team ratings prior to this week’s games, along with the ratings at the start of the season.

Current Rating Rating at Season Start Difference
Stade Toulousain 10.58 8.76 1.80
Bordeaux Begles 5.82 3.96 1.90
Stade Rochelais 5.02 4.85 0.20
Toulon 4.10 5.32 -1.20
Racing 92 2.52 2.75 -0.20
Castres Olympique 1.15 -0.09 1.20
Bayonne 0.73 -1.69 2.40
Section Paloise 0.05 1.38 -1.30
Montpellier -0.48 -0.96 0.50
Clermont -0.49 0.41 -0.90
Lyon -0.51 -0.18 -0.30
Stade Francais -0.86 1.86 -2.70
USA Perpignan -2.43 -0.66 -1.80
Vannes -9.48 -10.00 0.50

 

Performance So Far

So far there have been 63 matches played, 50 of which were correctly predicted, a success rate of 79.4%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Castres Olympique vs. Montpellier Nov 03 30 – 26 7.90 TRUE
2 Bayonne vs. Stade Toulousain Nov 04 12 – 8 -3.80 FALSE
3 Clermont vs. Bordeaux Begles Nov 04 32 – 27 -1.20 FALSE
4 Section Paloise vs. Racing 92 Nov 04 23 – 33 5.50 FALSE
5 Stade Rochelais vs. Stade Francais Nov 04 35 – 18 10.80 TRUE
6 Toulon vs. Lyon Nov 04 21 – 10 11.10 TRUE
7 USA Perpignan vs. Vannes Nov 04 32 – 13 12.60 TRUE

 

Predictions for Round 10

Here are the predictions for Round 10. The prediction is my estimated expected points difference with a positive margin being a win to the home team, and a negative margin a win to the away team.

Game Date Winner Prediction
1 Castres Olympique vs. Stade Rochelais Nov 24 Castres Olympique 2.30
2 Lyon vs. Clermont Nov 24 Lyon 6.70
3 Montpellier vs. Section Paloise Nov 24 Montpellier 5.80
4 Stade Francais vs. Racing 92 Nov 24 Stade Francais 3.10
5 Stade Toulousain vs. USA Perpignan Nov 25 Stade Toulousain 19.40
6 Toulon vs. Bayonne Nov 24 Toulon 9.90
7 Vannes vs. Bordeaux Begles Nov 24 Bordeaux Begles -8.80