Posts filed under General (1263)

November 4, 2017

A few details

Seeing a headline like

kumara

might cause an unwary person to think that eating purple kumara would reduce their risk of colon cancer by seventy-five per cent.

You, of course, would be suspicious and would want to read the story.

He found that when fed to three generations of mice bred with colon cancer, using the same gene which caused the disease in humans, purple kumara reduced the number of polyps by two-thirds or more.

So, the study is in mice. Mutant mice.  And it didn’t reduce the risk of colon cancer in these mice — which was basically 100% — it reduced the number of developing tumours.

It’s true that the mutation is one that occurs in people, too. About one in ten thousand people is born with the mutation that the mice had — these people have the mutation in every cell in their bodies, and they all get colon cancer if they don’t have major surgery.  And in the majority of ordinary people who get colon cancer, part of the  process is a mutation in this same gene in one cell.  So, the mutant mice are relevant.  There isn’t any problem with the research being in mice, just with the headline. Especially as further down in the story we hear about the equivalent dose of kumara in humans

“To eat 1kg of sweet potato every day is too hard.”

and that the kumara seems to have most potential as a way to produce a concentrated extract.

So far, there’s not much evidence either way on whether anthocyanins (basically, purple food other than beets or dragonfruit) really prevent cancer in humans.  Animal studies such as this one give good reasons to be hopeful; the history of other micronutrient-based prevention trials give good reasons to be skeptical.

 

October 30, 2017

Briefly

  • From Politico“Is Washington Bungling the Census?”
  • From Wired: China’s planned ‘Social Credit’ score
  • A McDonalds promotion in Canada advertises some high-level prizes and a 1 in 5 chance of winning. Some guy bought 100 orders of large fries, thinking he’d get forty prizes (2 tickets per order).  It’s actually two half-tickets per order, so he won 23 prizes. Mostly cheeseburgers. The moral: (a) read the instructions, and (b) most of the prizes are always just cheeseburgers (or the moral equivalent in other lotteries).
  • rawgraphs.io is a new tool for producing fairly attractive graphs quickly from spreadsheet data
  • [update] I nearly forgot Chris McDowall’s graphs of electorate vs party vote in the NZ election, from the Spinoff
  • Computer maps: then

 


and now (from Wikipedia)

814px-LACountyPopDensity

October 25, 2017

Mitre 10 Cup Predictions for the Mitre 10 Cup Finals

Team Ratings for the Mitre 10 Cup Finals

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
Canterbury 15.35 14.78 0.60
Wellington 12.26 -1.62 13.90
Taranaki 6.90 7.04 -0.10
North Harbour 6.48 -1.27 7.80
Tasman 3.60 9.54 -5.90
Counties Manukau 2.02 5.70 -3.70
Otago 0.25 -0.34 0.60
Bay of Plenty -0.14 -3.98 3.80
Auckland -0.33 6.11 -6.40
Waikato -3.17 -0.26 -2.90
Northland -4.04 -12.37 8.30
Manawatu -4.54 -3.59 -1.00
Hawke’s Bay -13.26 -5.85 -7.40
Southland -23.99 -16.50 -7.50

 

Performance So Far

So far there have been 74 matches played, 51 of which were correctly predicted, a success rate of 68.9%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Wellington vs. Northland Oct 20 49 – 21 18.60 TRUE
2 Bay of Plenty vs. Otago Oct 21 48 – 32 0.90 TRUE
3 Canterbury vs. North Harbour Oct 21 35 – 24 13.30 TRUE
4 Taranaki vs. Tasman Oct 21 29 – 30 9.10 FALSE

 

Predictions for the Mitre 10 Cup Finals

Here are the predictions for the Mitre 10 Cup Finals. 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 Wellington vs. Bay of Plenty Oct 27 Wellington 16.40
2 Canterbury vs. Tasman Oct 28 Canterbury 15.80

 

Currie Cup Predictions for the Currie Cup Final

Team Ratings for the Currie Cup Final

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
Cheetahs 4.33 4.33 -0.00
Sharks 4.06 2.15 1.90
Western Province 4.02 3.30 0.70
Lions 3.45 7.41 -4.00
Blue Bulls 0.48 2.32 -1.80
Pumas -8.75 -10.63 1.90
Griquas -10.19 -11.62 1.40
Cheetahs2 -30.14 -30.00 -0.10

 

Performance So Far

So far there have been 44 matches played, 30 of which were correctly predicted, a success rate of 68.2%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Sharks vs. Blue Bulls Oct 21 37 – 27 7.70 TRUE
2 Western Province vs. Lions Oct 21 19 – 5 4.30 TRUE

 

Predictions for the Currie Cup Final

Here are the predictions for the Currie Cup Final. 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 Sharks vs. Western Province Oct 28 Sharks 4.50

 

Not science yet

Three weeks ago there was a story in the Herald headlined Research reveals that divorce does run in the family (via Antonio Rinaldi on Twitter). The headline, as you’d expect, got the news wrong: the first sentence of the story is

Numerous studies have shown that children of divorced parents are more likely to get divorced when compared to those who grew up with parents who remained married.

The new claim was that divorce ‘runs in the family’ for genetic reasons. The researchers say

“Nearly all the prior literature emphasised that divorce was transmitted across generations psychologically.

“Our results contradict that, suggesting that genetic factors are more important.”

Now, when someone comes up with a finding that contradicts previous research and that they claim even they were surprised by, I’d want pretty good evidence. I’d want to look at what they actually found, and to see some discussion of how much the evidence is specific to adoptive families in a fairly homogeneous society such as Sweden.  In a perfect world, I’d want the story to have some independent input from someone who knows what ‘heritability’ means.  And I’d still worry about publication bias — maybe the academic journal would have published a paper saying ‘no, it’s still just environment’, but I bet the Herald wouldn’t have a story.

How good is the evidence in the story? Well, it has a link to the Daily Mail.

It’s pretty common for British science linkbait that turns up in the NZ papers to just link to the UK media. But here the research paper doesn’t even exist yet. The story says “will be published in an upcoming issue Journal Psychological Science.” Three weeks later, it’s still upcoming — this isn’t the usual problem of the embargo ending the day before a paper actually appears.

I can’t find a preprint or any other source of details, and as far as I can tell, the primary source for this story is a press release from Virginia Commonwealth University.

This isn’t science news.  It’s academic marketing.

October 22, 2017

Briefly

  • “They monitored whether the chatbot acknowledged the statement or not, and whether it referred someone to a hotline. Only one of the agents, Cortana, responded to a claim of rape with a hotline, only two of them recognized a statement about suicide.”  From freedom-to-tinker
  • China is building the world’s most powerful facial recognition system with the power to identify any one of its 1.3 billion citizens within three seconds.South China Morning Post
  • “Pornhub announced that it is using machine learning and facial recognition“. They say it’s to improve search, according to Vice, which is more or less why people are worried.
  • From the Herald: “ACC has paid out on 660 claims where (pedestrian) cellphone distraction has been noted as the injury’s cause.”  You, of course, are asking what that comes to as a percentage of car crash costs. Outsourced to @aw_nz on Twitter
October 17, 2017

Mitre 10 Cup Predictions for the Mitre 10 Cup Semi-Finals

Team Ratings for the Mitre 10 Cup Semi-Finals

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
Canterbury 15.56 14.78 0.80
Wellington 11.41 -1.62 13.00
Taranaki 7.81 7.04 0.80
North Harbour 6.27 -1.27 7.50
Tasman 2.69 9.54 -6.90
Counties Manukau 2.02 5.70 -3.70
Otago 1.61 -0.34 2.00
Auckland -0.33 6.11 -6.40
Bay of Plenty -1.50 -3.98 2.50
Waikato -3.17 -0.26 -2.90
Northland -3.19 -12.37 9.20
Manawatu -4.54 -3.59 -1.00
Hawke’s Bay -13.26 -5.85 -7.40
Southland -23.99 -16.50 -7.50

 

Performance So Far

So far there have been 70 matches played, 48 of which were correctly predicted, a success rate of 68.6%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Taranaki vs. Manawatu Oct 11 46 – 25 17.90 TRUE
2 Wellington vs. Northland Oct 12 36 – 18 18.70 TRUE
3 Auckland vs. Canterbury Oct 13 27 – 32 -13.40 TRUE
4 Bay of Plenty vs. Waikato Oct 14 36 – 32 6.00 TRUE
5 Otago vs. Southland Oct 14 43 – 19 30.80 TRUE
6 Counties Manukau vs. Tasman Oct 14 52 – 30 -0.80 FALSE
7 North Harbour vs. Taranaki Oct 15 64 – 33 -3.50 FALSE
8 Hawke’s Bay vs. Manawatu Oct 15 36 – 31 -7.10 FALSE

 

Predictions for the Mitre 10 Cup Semi-Finals

Here are the predictions for the Mitre 10 Cup Semi-Finals. 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 Wellington vs. Northland Oct 20 Wellington 18.60
2 Bay of Plenty vs. Otago Oct 21 Bay of Plenty 0.90
3 Canterbury vs. North Harbour Oct 21 Canterbury 13.30
4 Taranaki vs. Tasman Oct 21 Taranaki 9.10

 

Currie Cup Predictions for the Currie Cup Finals

Team Ratings for the Currie Cup Final

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.

Note that Cheetahs2 is the Cheetahs team in weeks when the first team is playing in the Pro14.

Current Rating Rating at Season Start Difference
Cheetahs 4.33 4.33 -0.00
Sharks 3.87 2.15 1.70
Lions 3.84 7.41 -3.60
Western Province 3.62 3.30 0.30
Blue Bulls 0.67 2.32 -1.70
Pumas -8.75 -10.63 1.90
Griquas -10.19 -11.62 1.40
Cheetahs2 -30.14 -30.00 -0.10

 

Performance So Far

So far there have been 42 matches played, 28 of which were correctly predicted, a success rate of 66.7%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Blue Bulls vs. Pumas Oct 13 52 – 32 12.80 TRUE
2 Lions vs. Cheetahs Oct 14 44 – 17 2.50 TRUE
3 Sharks vs. Western Province Oct 14 20 – 31 5.90 FALSE

 

Predictions for the Currie Cup Final

Here are the predictions for the Currie Cup Final. 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 Sharks vs. Blue Bulls Oct 21 Sharks 7.70
2 Western Province vs. Lions Oct 21 Western Province 4.30

 

October 10, 2017

Avocado is the new chocolate

Q: Did you see “Just one extra banana or avocado a day could prevent heart attacks and stroke”

A: Hmm.

Q: It’s the potassium

A: Uhuh

Q: New Research Suggests

A: The effects of higher-potassium foods on blood pressure aren’t ‘new research’.  Look at what the American Heart Association says, or Harvard Health.

Q: Those sites don’t mention avocados, though. Is that what was new about the research?

A: No, that’s probably to meet the day’s quota for avocado stories.

Q: But at least the health message is real? They quote the researcher “The findings demonstrate the benefit of adequate potassium supplementation on prevention of vascular [hardening]”. With proper brackety things like we tell students to use.

A: We might prefer students to quote the rest of the clause , as the story does later: “demonstrate the benefit of adequate potassium supplementation on prevention of vascular calcification in atherosclerosis-prone mice” (emphasis added)

Q: So it probably wasn’t bananas, either.

A: No, high-cholesterol, high fat mouse food with high or low potassium.

Q: But the high-potassium mice lived longer? They had fewer heart attacks and strokes?

A: This is a lab experiment. It’s never going to end well for the mice. But they had stretchier arteries while they were alive.

Q: So what was the point, if we already knew higher-potassium diets with lots of fruit and veg are good for blood pressure?

A: The point was to find out how it works — which genes and proteins and so on.

Mitre 10 Cup 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
Canterbury 16.32 14.78 1.50
Wellington 11.48 -1.62 13.10
Taranaki 10.66 7.04 3.60
Tasman 4.74 9.54 -4.80
North Harbour 3.14 -1.27 4.40
Otago 2.22 -0.34 2.60
Counties Manukau -0.03 5.70 -5.70
Auckland -1.08 6.11 -7.20
Bay of Plenty -1.32 -3.98 2.70
Manawatu -3.19 -3.59 0.40
Northland -3.26 -12.37 9.10
Waikato -3.35 -0.26 -3.10
Hawke’s Bay -14.33 -5.85 -8.50
Southland -24.60 -16.50 -8.10

 

Performance So Far

So far there have been 62 matches played, 43 of which were correctly predicted, a success rate of 69.4%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Tasman vs. North Harbour Oct 04 21 – 14 4.80 TRUE
2 Manawatu vs. Counties Manukau Oct 05 24 – 29 2.10 FALSE
3 Canterbury vs. Taranaki Oct 06 43 – 55 14.40 FALSE
4 Otago vs. Bay of Plenty Oct 07 28 – 36 11.00 FALSE
5 Northland vs. Hawke’s Bay Oct 07 34 – 7 12.40 TRUE
6 Southland vs. Wellington Oct 07 12 – 61 -28.40 TRUE
7 Tasman vs. Auckland Oct 08 31 – 18 8.90 TRUE
8 Waikato vs. North Harbour Oct 08 11 – 13 -2.80 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 Taranaki vs. Manawatu Oct 11 Taranaki 17.90
2 Wellington vs. Northland Oct 12 Wellington 18.70
3 Auckland vs. Canterbury Oct 13 Canterbury -13.40
4 Bay of Plenty vs. Waikato Oct 14 Bay of Plenty 6.00
5 Otago vs. Southland Oct 14 Otago 30.80
6 Counties Manukau vs. Tasman Oct 14 Tasman -0.80
7 North Harbour vs. Taranaki Oct 15 Taranaki -3.50
8 Hawke’s Bay vs. Manawatu Oct 15 Manawatu -7.10