Tanya Gold on mountaineering

Alas, Tanya Gold of The Guardian has descended to clickbait headlines to keep up interest in her articles; her latest on the Everest avalanche that killed thirteen Sherpas is particularly painful:

As commercial climbing has exploded, Everest has shifted from an explicit wasteland to a moral and internal one which also serves as a perfect metaphor for the contempt in which we hold the planet.
It is not simply the ordinary exploitation of the Sherpas, which is soothed away with the knowledge that in Nepal, where the average annual wage is $700, a Sherpa can make $5,000 in a two-month season – although it is impossible to imagine this kind of death rate being tolerated if the dead were rich and white.
The fall of a serac in the Khumbu icefall was tragic, but by no means a bolt from the blue. Jon Krakauer's account of the 1996 Everest disaster that killed eight climbers (which Tanya references) describes how perilous the icefall can be - falls of huge, building-sized chunks of ice can happen without any more warning than a "look out!" from your companions, and even an injury such as a broken leg can prove fatal in the perilously hazardous conditions of 18000+ feet altitude where simply being there can provoke debilitating or fatal altitude sickness.

The Everest climber fatality rate between 1922 and 2006 is about 2% overall, and about 1.4% if you exclude porters (Sherpas and others). Certainly, being a Sherpa is more dangerous than being a paying climber, but as a Sherpa you're still about the fatality rate of an astronaut and your relative compensation is better - if a Sherpa makes 7x the average annual wage, look at a top-end salary for an astronaut based in Houston, TX which is about $141K, or about 2.5x the mean US wage. This is not comparing apples to apples, but at least gives you a ballpark picture of how well Sherpas are compensated. Sure, they have a dangerous job, but no-one is forcing them into it and they probably have a better understanding of the dangers than most of the climbers. So when Tanya says:

...although it is impossible to imagine this kind of death rate being tolerated if the dead were rich and white.
it turns out we actually tolerate this death rate already, even though the dead are moderately well paid and mostly white. Perhaps Tanya doesn't have a great imagination.

Looking at Tanya, I think it's safe to say that she's in no danger of attempting to summit Everest (or indeed any peak more challenging than Brown Willy) any time soon. Perhaps then she cannot appreciate what drives people to push themselves to their physical and mental limits to overcome the imposing challenge of high altitude mountaineering, and we should not blame her for that. We should, however, nail her to the wall for comments claiming that money trumps humanity for climbers:

But more tourists claim "tunnel vision" and "summit fever". They do not pause; they are slaked on their own fantasies; they paid too much. Madness indeed.
At Everest summit altitudes, even a very fit climber has to draw on all their reserves of strength to survive the Death Zone. Even a small amount of additional exertion in aiding a fellow climber can cause them to collapse and double the number of people that need help. When you're on a climb to the summit of Everest, your survival is your own responsibility; it's unlikely that anyone will be able to help you; trying to help someone else can make you pay much, much more than just your climbing fees. All climbers who have reached the final base camp will know and understand this, much more than someone like Tanya can even strain to appreciate.


Strategy in 2048

I've been playing the 2048 game which (if you haven't played it yet) is the most phenomenonal time sink invented. To save people from sanity, here are some general game hints; using this strategy I manage to obtain the 2048 tile in roughly 50% of games.

  1. Start by building up the big numbers in the lower left corner, spreading along the bottom row.
  2. As the bottom row is nearly full (say you have [16, 8, 4, _] start filling the third row with numbers starting from half the lower left number (say, [8, 4, 2, _)
  3. When the opportunity arises to have the bottom row full and the third row filling 3 of 4, right shift the board so the third row numbers line up above the same numbers on the bottom row and then drop them down and shift left to increase your bottom row numbers by a factor of 2.
  4. When the bottom row starts getting big (say, 64+ as the left corner number) start trying to order the third row in the opposite direction. If the bottom row is [128, 64, 32, 16] start trying to create 16 at the end of the third row. Whenever you can, drop numbers into the bottow row.
  5. At nearly all cost, avoid filling row 2 so that you have no option but to move the board up - that will trap small numbers under your row of big numbers. If that happens, drop the board again immediately (and hope).
  6. If you end up with 2 or 4 tile to the left of a big number tile on your bottom row, focus on increasing that tile number until it matches your big number so you can left-shift the bottom row and have the biggest tile in the bottom left corner.
Good luck!


Assuaging public concern by taking the piss

It seems that homeopathy is gaining adherents in Portland, USA: 38 million gallons of water had to be flushed from a reservoir after a guy took a leak in it:

The Portland Water Bureau there's little risk to the public's health but bureau administrator David Shaff says, "Our customers have an expectation that their water is not deliberately contaminated. We have the ability to meet that expectation."
Um, yes, but ability and requirement are not the same thing...

Now this wasn't as expensive as it could have been elsewhere in the country, e.g. neighbour California is in a drought and water is a precious resource there, whereas Portland is famous for its damp climate. Still, treating water costs actual money. Why did the Portland Water Bureau feel compelled to take this drastic action? A pint of urine in a 38M gallon reservoir would have been practically impossible to detect, let alone have any effect. You'd get more contamination every day from birds pooping.

It's all about perception, of course. Once it became known that someone had peed in the reservoir, if the PWB had done nothing then there would have been a popular outcry (fuelled by the press, who love a story like this; can you imagine the puns if the Sun wrote this up?) The PWB is merely pre-empting these protests, saving itself from the grief by expending someone else's money. Wouldn't you?

Mind, anyone in Portland who still drinks Budweiser or Coors wouldn't have much room to complain...


Dodgy assertions from CASH's head medic

The salt-haters have been praising the reduction in dietary salt for an important role in the 42% fewer stroke fatalities and 40% drop in those dying from coronary heart disease:

The researchers, who include Britain's leading campaigner against added salt in food, claim that diminishing levels of salt was "an important contributor" to falls in blood pressure over the eight-year period. "As a result, the decrease in salt intake would have played an important role in the reduction of stroke and ischaemic heart disease mortality during this period," say the authors.
"Would have played"? That's a funny way of saying "was shown at a 95% confidence level to have played"... Co-author Graham MacGregor is the chair of CASH; his daytime job is Professor of cardiovascular medicine at the Wolfson Institute of Preventive Medicine at Queen Mary. So surely we can expect a rigorous and impartial analysis of the data from him.

If I'd been looking to prove or disprove this assertion, I'd have looked at stroke and heart disease rates in a range of patients over this time frame, where I had some objective measure of salt in their diet (urine samples), and looked to see whether patients with lower salt levels (in a group of patients with otherwise similar exercise, age, gender, racial stats) were correlated with lower stroke and heart disease rates. Is this what they did?

Patrick Wolfe, professor of statistics at University College London, took issue with the authors for assuming that the improved blood pressure seen in the 2003-2011 was largely the result of reduced salt intake. "Plausibility of assumption does not equal evidence," he said.
Oh. Apparently not, then. That's a piss-poor basis for the claims CASH (and international co-conspirator WASH) have been touting around about salt reduction. As commentor ID4968047 notes this reduction in strokes and heart disease could equally have come from the reduction in smoking in the past 10 years - the obligation is on Prof. MacGregor to show otherwise. Looking at CASH's writeup of the paper (the link to the paper isn't available yet, looks like) they say:
Confounding factors that were looked at include age, gender, ethnicity, education, incomes, alcohol consumption, fruit and vegetable intake and BMI.
Exercise and smoking are not mentioned. Nor do they reference the increase in statin use - and indeed Aseem Malhotra from Action on Sugar claims that statins are harmful and don't reduce mortality which is interesting as they seem to be a prime competitor to CASH/Action on Sugar's crusades against sugar and salt. Malhotra's claims got panned for lack of evidence by Prof. Rory Collins from Oxford.

It seems that others in the medical stats community have doubts too:

David Spiegelhalter, professor of the public understanding of risk at Cambridge university, cited the researchers' admission that the fall over that time in systolic blood pressure would be expected to reduce strokes by just 11% and heart attacks by 6%, small amounts of the total falls. [my emphasis] Reduced blood pressure did not represent the authors' claimed "substantial contribution" to the reduced death rates.
This is not to say that Graham MacGregor is obviously wrong in his claims. They might be true but it is a real reach to claim that this study supports them. And if this is the best he can do, I'd suggest the Marcela Trust / OMC Investments crowd who are backing CASH find someone with a better stats background to organise their crusade against salt and sugar.

Update: just managed to dig up the link to the full text in BMJ Open. From a quick look the focus was on linking salt reduction with BP reduction but not explicitly with stroke/CVD reduction.

The authors themselves admit:

It is likely that several factors, that is, the fall in BP, total cholesterol and smoking prevalence, the reduction in salt intake and the increase in the consumption of fruit and vegetables, along with improvements in the treatments of BP, cholesterol and CVD, contributed to the decrease in stroke and IHD mortality.
They have a stab at isolating the effect of salt by casting tea leaves:
it was estimated that a 2.7 mm Hg reduction in systolic BP that occurred with salt reduction would be predicted to reduce stroke by approximately 11% and IHD by 6%.
but even then the 2.7mmm Hg reduction figure they quote is the net over 8 years including factors such as decrease in smoking and increase in statins, so to attribute it to just salt reduction is "optimistic". They appeal to studies in Japan and Finland in the late 60's / early 70's but the huge gaps in time, diet and environment between now and then render the comparison unconvincing. If that's the best argument they've got to offer, I'd hate to see the ones that didn't get selected for use in the paper.

The conclusions are what kill the paper for me:

The reduction in salt intake is likely to be an important contributor to the falls in BP in England from 2003 to 2011. As a result, the decrease in salt intake would have played an important role in the reduction in stroke and IHD mortality during this period. [my emphasis]
That's a terribly weak conclusion even to my relatively untrained eyes. If they could state this more strongly, they would. Instead, they reserve their strength for polemic:
... the mean salt intake in England (8.1 g/day in 2011) was still 35% higher than the recommended level of 6 g/day, and 70% of the adult population (80% men and 58% women) had a daily salt intake above the recommended level.[14] Therefore, continuing and much greater efforts are needed to achieve further reductions in salt intake to prevent the maximum number of stroke and IHD deaths.
Reference 14 doesn't justify the 6g/day level, it's just a measurement of sodium levels. The authors don't make any reference I can see to why the recommended level should be 6g/day and not (say) 10g/day or 3g/day. If you're appealing to magic figures in your conclusion it doesn't give great confidence in the rest of your article.


A lesson from OpenSSL

If you are paranoid about secrecy on the web, today's news about a bug in OpenSSL may make you feel justified. OpenSSL is an open source library that is used by companies, individuals and governments around the word to secure their systems. It's very widely used for two reasons: 1) a very useful set of licensing conditions that essentially say you're fine to use it as long as you credit the right authors in the source and 2) because so many commercial firms depend on it, its source has been scrutinised to death to spot both performance and functional bugs.

A one-paragraph primer on SSL (Secure Sockets Layer): it's the method by which a regular web browser and a secure web server communicate. You're using it whenever the address bar in your browser displays a URL starting with "https:" instead of "http" - so that's your online banking, Facebook, Google, Twitter, Amazon... Most of these secure web servers will be using OpenSSL - there are alternatives to OpenSSL but none of them are compellingly better, and in fact the widespread usage of OpenSSL probably makes it less likely to contain security bugs than the alternatives so there's safety in belonging to the herd.

Anyone who's thinking "aha, my company should avoid this problem by developing their own SSL implementation" or better yet "my company should develop a more secure protocol than SSL, and then implement that!" has not spent much time in the security space.

And yet, someone has just discovered a bug in a very widely used version of OpenSSL - and the bug is bad.

To get some perspective on how bad this is, the Heartbleed.com site has a nice summary:

The Heartbleed bug allows anyone on the Internet to read the memory of the systems protected by the vulnerable versions of the OpenSSL software. This compromises the secret keys used to identify the service providers and to encrypt the traffic, the names and passwords of the users and the actual content. This allows attackers to eavesdrop on communications, steal data directly from the services and users and to impersonate services and users.
Sounds dire, no? Actually the above description is the worst case; the bug gives an attacker access to memory on the secure server that they shouldn't have, and that memory *might* contain secrets, but the attacker doesn't get to control which area of memory they can read. They'd have to make many queries to be likely to gain access to secrets, and it's not too hard to spot when one small area of the Internet has that kind of unusual access pattern to your server. Even if they make 1000 reads and get one secret, they still have to be able to recognise that the data they get back (which will look like white noise) has a secret somewhere in it. I don't want to downplay how serious the bug is - anyone running an OpenSSL server should upgrade it to get the fix as soon as humanly possible - but it's not the end of the world as long as you're paying attention to the potential of attacks on your servers.

Still, isn't this bug a massive indictment of the principle of Open Source (that you'll have fewer bugs than commercial alternatives)? It's appropriate here to quote Linus's Law, codified by Open Source advocate Eric Raymond and named after the founder of the Linux operating system Linus Torvalds:

"Given enough eyeballs, all bugs are shallow"
or more formally:
"Given a large enough beta-tester and co-developer base, almost every problem will be characterized quickly and the fix will be obvious to someone."
Unfortunately, the larger and more complex your codebase, the larger the tester and developer base has to be and the longer it takes to find problems...

It's tempting to look at this security alert and declare that Open Source has allowed a critical bug to creep into a key Internet infrastructure component (clearly true) and declare that this can't be the right approach for security. But you have to look at the alternatives: what if OpenSSL was instead ClosedSSL, a library sold at relatively low cost by respected security stalwart IBM? ClosedSSL wouldn't have public alerts like this; if IBM analysis found bugs in the implementation then they'd just make an incremental version release with the fix. But the bug would still be there and would not be any less exploitable for the lack of announcement. You'd have to assume that government agencies (foreign and domestic) would bust their guts to plant someone or something with access to the ClosedSSL team mail, and in parallel apply object code analysis to spot flaws. The flaw would not be much less exploitable for lack of publicity, and would likely be in the wild longer because IBM would never announce a flaw so vocally and so users would be more lax about upgrades.

There are then two lessons from OpenSSL: 1) that even Open Source inspection by motivated agencies can't prevent critical bugs from creeping into security software and 2) that no matter how bad the current situation is, it would be worse if the software was closed-source.


Diversity in everything except opinion

This is terrifying. Mozilla CEO Brendan Eich has been forced out because of his personal position against gay marriage. If you don't believe me, read the mail from painfully hip lawyer and Mozilla Foundation chair Mitchell Baker:

We didn’t act like you’d expect Mozilla to act. We didn’t move fast enough to engage with people once the controversy started. We’re sorry. We must do better.
Brendan Eich has chosen [ah! free choice? really?] to step down from his role as CEO. He's made this decision for Mozilla and our community. [He's been given the choice to resign or be fired.]
Mozilla believes both in equality and freedom of speech. Equality is necessary for meaningful speech. And you need free speech to fight for equality. Figuring out how to stand for both at the same time can be hard.
Yes, it can be hard to stand for equality and freedom of speech, but clearly you've opted out of that stance and gone for sucking up to the media-approved line of thought. 60% of Americans support gay marriage (at least publicly) so it may be a majority opinion but opposition can't reasonably be dismissed as a small clique of bigots. It seems that opposing the majority opinion is only allowed when the majority opinion is "wrong". Let's remember that the California Supreme Court (no bastion of political orthodoxy) did not see anything wrong with allowing Californian voters to vote freely on whether marriage should be restricted to male-female partners in California.

I'm reminded of Bob Hope's quote after the 1975 Consenting Adult Sex Bill was passed:

I've just flown in from California, where they've made homosexuality legal. I thought I'd get out before they make it compulsory.
You're still allowed to choose to be heterosexual, but if you value your job and career you'd be a brave person to even hint at wavering on the issue of gay marriage.

Gay arch-blogger Andrew Sullivan can see where this is leading and he's really not convinced it's a good idea:

If this is the gay rights movement today – hounding our opponents with a fanaticism more like the religious right than anyone else – then count me out. If we are about intimidating the free speech of others, we are no better than the anti-gay bullies who came before us.

Allowing the media to dictate the acceptable positions on thought is not going to end well, and I wonder if the gay marriage lobby have really thought this one through. If Fox News continues its rise and the (more left-leaning) rest of the media continues its decline, do they want opposition to Fox editorial policies to become grounds for hate campaigns against people?

Obamacare is going to have a doctor problem

An aspect of the American Affordable Care Act (aka Obamacare) which I hadn't appreciated until this week was the degree to which it may be scuppered by primary care physicians (PCP, the USA equivalent of a GP). Chatting with a middle-aged friend who is moving to a small-ish American town and changing jobs, she opened my eyes to the mysteriously unpublicised problems which the implementation of the ACA is about to cause everyone.

She was visiting her new town last week, sorting out her house and meeting her new workmates in preparation for moving there for good in June. One item on her list was sorting out a new PCP. She had the details for her new insurance plan with one of the state providers, so dropped by a doctor's office near her house to register. No joy, that doctor wasn't accepting new patients. OK, so go back to the insurance provider website to identify a wider shortlist of providers in town.

No joy at the first doctor. Or the second. Or the third. This was getting ridiculous. She had a friend already working in her new workplace, so asked him if he could help. His doctor wasn't accepting new patients either, but the friend had a good relationship with the doctor, so asked him directly. Still no luck. Eventually my friend managed to find a large medical center open to new patients - over 60 miles away. She signed up, because that was the best offer there was.

There was one doctor in a nearby town open to new patients, but after a quick check on his reviews it became rapidly clear why. It sounds like he hadn't progressed much past the "trial by ordeal" approach to illness, and was still reading pre-Pasteur literature on infection control.

Why this insanity of unavailability? It turns out that the coming avalanche of patients signed up on ACA-compliant plans is not making doctors sleep well at night. Not only are these patients much more likely to be sick than their current patients, the main concern of practices is that they're going to lose money on treating these patients. The remuneration rate for doctors for ACA patients is - at least in some states, and I suspect all - based on 80% of the standard practice fees from 3 years ago. That's not great, but much worse is the experience with Medicare (federal medical coverage for the elderly). My friend used to work in a doctor's office, and they had a profitably employed office employee whose sole job was to push back against government agencies spuriously denying payment for Medicare claims. If there were any abnormalities at all in a claim, Medicare would deny it in the hope that only solidly valid claims would be retried. A denial is, after all, cheap.

I digress, but bear with me. Do you older readers remember when The Simpsons started and they introduced us to Marge's sisters Patty and Selma, stalwart misanthropic employees of the local Department of Motor Vehicles? There's a reason why the American viewers of the show laughed, and it wasn't to do with absurdity. There's no-one more un-fireable than a federal or state bureaucrat, and their attitude to their customers is exactly what you'd expect - entirely down to their general disposition to humanity. That's what the doctors' billing teams are going to be dealing with. Only by being better acquainted with the rulebook will they be able to get their due payments out of the ACA system, and even then those payments will be small and paid late.

Having a new government agency and new set of rules means that small practices are extremely worried about their costs and ability to maintain existing patients. Because (I believe, from chatting to the front desks of a few offices) you can't be selectively open to new patients based on their particular insurer, the easiest option for small providers is to batten down the hatches until the picture is clearer. Only the very large healthcare centers can take advantage of their economy of scale to accept the new stream of ACA-covered patients - and with them the standard employer-covered and easier to manage new patients.

I wonder whether this problem with finding doctors is behind the proposed rise in rates for ACA-compliant plans? Perhaps you will be able to look at the rate rise in the next few years and extrapolate the "marginal cost of doing business with government". As it stands, the best they can hope for is to break even:

Cigna, which is selling Obamacare plans in five states and is considering whether to expand that further in 2015, has said it won't make money on the business this year. It expects to have signed up as many as 100,000 new members under the program for this year.

So for the Affordable Care Act, if you're sick then you may be able to get coverage where you couldn't before, but sure as heck if you're outside a major city then you're going to find it a challenge to get a primary care physician to see you and get your care started. Now I'm wondering what the ER departments of ACA-plan-accepting hospitals are going to experience in the next year.