Friday, 24 April 2009

Cyclamate Sweeteners Shrivel Your Testicles

skeletal formula of sodium cyclamate, from Wikipedia, tagged public domain, originated by Wikipedia member 'Harbin'Sometimes I notice details that don't quite seem to connect, and it bugs the hell out of me until I eventually find out why.

Some years back, I saw an episode of a detective show (perhaps "Columbo"?), whose resolution hinged on the idea that there was a particular artificial sweetener used in soft drinks in the 1960's that then got withdrawn. That was a bit before my time, but it puzzled me that the writers seemed to assume that the viewer knew about this, but somehow I hadn't heard of it. So I thought I'd look the thing up to see if it was true.
Apparently it was – according to the literature, cyclamate sweeteners appeared in mainstream products before being banned by the FDA in 1969. But a substance doesn't just get banned from food production without kicking up a bit of media discussion, and I was arrogant enough to figure that if I hadn't come across any such discussion then ... there was probably more to this subject than met the eye. My antennae started twitching. Something smelled wrong.

So I looked deeper. The listed reason why cyclamates were withdrawn, according to the first wave of usual sources, was a possible "slightly elevated cancer risk". Again, this didn't smell right – I'd heard a lot over the years about the similar alleged (small, supposed) risk of bladder cancer associated with saccharine, which wasn't banned in most countries, so where had the corresponding discussion about cyclamates gone? There was an cultural anomaly here – the public discussions that ought to have happened seemed to be missing, and I now badly wanted to find out why.

This was long before the days of Google, so in about 1990 I found myself at an outpost of the British Library, crouched over an old green-screen text terminal that had basic online subscription access to a medical research database, and there I found the obvious answer to why industry people didn't discuss cyclamate side-effects. A distinctive three-word medical term, that once heard and explained, you don't tend to forget.

Cyclamates are associated with ITA.

ITA stands for Irreversable Testicular Atrophy.


Yes, you read that correctly. It seems that if you're a primate, and male, cyclamate sweeteners can cause your balls to progressively shrivel and wither away. Permanently. Researchers don't know why.

So that was it. That was why nobody told the public what they'd discovered, and why the product was taken off the market, using the iffy "cancer" argument as an excuse. It wasn't in the interests of the drinks companies to mention that they'd probably been chemically castrating some of the guys who drank their cola, it wasn't in the interests of the FDA to admit that they'd approved a substance for mainstream use that had been permanently shrivelling the Male American Public's manly bits. It probably also wasn't in the interests of the research community to go around telling outsiders about their part in a major public health boo-boo that many of those outsiders would find difficult to forgive, if they knew about it. But if you bypassed the commentaries and looked up the original research papers, there it was, in stark black-and-white. ITA.

Cyclamate Returns

The story's moved on since then. Some companies really liked using cyclamate as an ingredient – it was cheap, people preferred the taste to saccharine, and it avoided the later nasty public-relations mess associated with Nutrasweet and product safety. And the biochemical/food industry did some digging of their own, and realised that actually, organisations like the FDA might not be allowed to ban cyclamates.

See, the FDA's remit is public health, and the industry lobbyists started arguing that that having permanently shrunken testicles doesn't actually count as a health problem (no matter how angry the owners of those testicles might be if they found out why). It isn't traditionally associated with work disability (unless you're a porn star), and there's no obvious associated reduction in life expectancy, unless you start to guess at factors like depression and impotence-related suicides.

A product that damages the testicles of male customers doesn't obviously kill anybody. In fact (the industry argued), the associated reduction in testosterone in guys with withered testes might even be associated with a statistical reduction in the frequency of certain testosterone-related cancer deaths (for instance, high testosterone is supposed to exacerbate prostate cancer). Since castrati were generally reckoned to have a greater life expectancy than "intact" blokes, there was an argument that the use of their sweetener product might actually extend average male lifespans rather than reduce them. So (the industry argued) not only were the FDA not allowed to use the ITA argument as a reason for banning the product, they couldn't use the weaker "bladder cancer" argument either, unless they could show that the hypothetical life-expectancy reduction due to increased incidence of bladder cancer was expected to be greater than the corresponding LE extension due to reduced male hormone levels. Cyclamates probably weren't "harmful" if you judged "harmfulness" by a number based on medical life expectancy.
A further argument was that if the potential sexual-function-impairment aspects of cyclamates were outside the FDA's remit, then the FDA was not supposed to tell anyone about them in their reports, because it wasn't the job of a government department to use state funding to "bad-mouth" a product by mentioning negative aspects of that product that weren't anything to do with them. The FDA were supposed to shut up.

So now cyclamates are finding their way back into food, and for a few years now, industry groups have been more bullish about lobbying for the FDA ban to be removed. As a page on the National Cancer Institute website delicately puts it:
" A food additive petition is currently filed with FDA for the reapproval of cyclamate. The FDA's concerns about cyclamate are not cancer related. "

One last point: if you're reading this and feeling smug because you're female ... well, don't.
See, we don't yet know the mechanism by which cyclamates appear to damage and kill off seminal frond tissue, and it may well be that cyclamates might be doing do something similar to the female reproductive system, unnoticed. Atrophied ovarian tissue is going to be more difficult to spot in the lab than atrophied testicles, simply because its not as easy to do a "before and after" weighing comparison with internal organs. We also don't know whether cyclamate's attack on the germ cells might be associated with heritable genetic or epigenetic damage to the reproductive cells that survive. If your guy's taking cyclamate sweeteners, is it damaging his sperm, and affecting any kids that you might have with him, from that sperm? And what happens if you're pregnant with a male child while ingesting a lot of cyclamate? Does the reproductive-tissue-shrinkage effect in adult males have a counterpart that affects the growth and development of that tissue in the fetus?

There are some genuinely nasty possibilities here.

Friday, 17 April 2009


The Cost of Living - short film
One of my mates is a filmmaker, and currently has one of his short films ("The Cost of Living") featured on the BBC Film Network site.
[Sept 09 update: it's now also on MiShorts]

When they made it, I came down for a few days (along with a bunch of other people) to watch the filming and help out. They basically took a two-storey flat and remodelled some of the insides for the shoot. The flat had full-height sliding windows along one wall, which were blocked off with some arty alcoved false walls, and upstairs provided a perfect vantage point for setting up the lighting and sound.

It's quite impressive to watch something like this happening. It's like a military operation, they go in, remodel, redecorate, install all the gear (including those great big trolley things on rails for doing tracking shots), shoot everything, then disassemble and make good, and go home.

The tv screens in the film were my LCD computer monitors that I loaned them, disassembled and fitted with new temporary surrounds by the production designer, Fabrice Spelta ... although they obviously aren't recognisable on-film. Fabrice also designed and installed the arty interior remodelling, which I thought (in conjunction with the lighting) gave the final film a really wierd surreal feel, a bit like Andrei Tarkovski's "Solaris". When those curved interior features line up right, they conspire to produce an "eye" shape, which fits in well with the film's creepy theme of subliminal messaging and constant monitoring. Natasha Collymore did the animated "shopping site" screen graphics.

Monday, 13 April 2009

Albert Einstein, Tea, and the Wall of Death

You may have noticed that when you stir a mug of tea, the tea leaves at the bottom congregate in the middle.

This is potentially disturbing behaviour – see, when you stir the tea, centrifugal forces throw the tea and the tea leaves against the outer wall of the mug, as if there's an outward-pointing gravitational field (the "wall of death" effect) [*]. If the tea leaves were denser than the tea, we'd expect them to be thrown harder and to "sink outwards" and collect at the outer wall, while if the the leaves were lighter than the tea, we'd expect them to be floating around at the top of the mug, rather than sitting at the bottom. So our two main options for where the tea leaves ought to end up, based on density, seem to be either "bottom of mug, around the edge", or "top of mug". In real life, the tea leaves decide to do something else.

So what gives?

Albert Einstein published the answer in a paper entitled "The cause of the formation of meanders in the courses of rivers and of the so-called Baer's Law" in 1926, which was published in Die Naturwissenschaften, complete with a diagram of a cross-section of a cup of tea.

What's happening here (said Einstein) is that the tea leaves are sinking because they are denser than the surrounding tea, but they're also being swept to the centre of the mug by a vortex circulation pattern.
The stirred tea doesn't just rotate within the mug as a simple solid cylinder. There's frictional dragging associated with the sides of the mug, and with the bottom of the mug. The side-wall dragging effect is almost the same at all heights in the tea [**], but the base-dragging effect means that as the stirred tea slows through friction with the mug, the tea at the bottom has always lost a little more speed, because of the additional source of friction. It's always rotating a little more slowly than the rest of the tea. So the centrifugal forces in the "slower" layer of tea at the bottom of the mug push outwards less strongly than those in the faster-rotating tea at the top, and as a result, the tea at the top of the mug "wins the battle" and pushes the tea at the bottom of the mug back on itself, inwards to the centre.

So the rotational speed differential induces a vortex circulation pattern in the tea. The rotating tea at the top surface moves outwards to the edge of the mug, and then crawls down the side-walls in a spiral until it reaches the bottom. Then it moves inwards towards the centre, and finally forms a rising column of tea in the centre of the mug until it returns to its starting point, and does the whole thing all over again (since the average rotation speed has slowed even more since the last circulation cycle).

The current is usually powerful enough to scrape the tea leaves inwards towards the centre of the mug, but its usually not quite strong enough to lift them back up to the surface, so the leaves tend to collect as a little curve-sided cone-shaped pile in the centre. Which you can see if you have a glass mug, and don't add milk.

Tea, Einstein, vortex. Problem solved.


* If we're doing this as a Newtonian calculation we say that the tea is riding up the sides of the mug because it's attempting to move in a straight line and is being thwarted by the crockery wall, whereas if we apply Mach's Principle, and/or the general principle of relativity, it's equally legitimate to say that the tea itself isn't rotating, but the outside universe rotating around it creates a special sort of radial gravitational field that draws the tea outwards from the rotation axis. In the first calculation the tea pushes outwards against the walls because of its inertial mass, in the second the outward effect is gravitational, and the tea is drawn outward by the effect of its gravitational mass. So under a general theory of relativity, the inertial and gravitational masses of a body can't be separated, because the inertial and gravitational descriptions are interchangeable.

** Okay, so the side-wall dragging effect is different at different heights too, because the base-dragging effect gives the tea different rotational velocities at different heights. This often happens in physics, we define two variables that're
supposed to be independent, and then we find that in practice they interact and cross-breed and twist and twirl around each other in exotic ways that're much more difficult to model. We often try to ignore these additional levels of complexity in the hope that they won't upset our final results too much. Sometimes we're right.

Monday, 6 April 2009

Google Analytics, and World Domination geographical traffic, Jan-March (Q1) 2009Every mad scientist should have a big world map on the rear wall or their Secret Lair, with pins or lights on it. It's traditional, and I always had a nagging feeling that I was somehow letting the side down by not doing it.

Google to the rescue! They have a thing called Google Analytics, that generates code that you then embed in all of the web-pages that you want tracked. Google get to sneakily snoop on your site's traffic, and in return, you get to call up breakdowns of traffic sources and search terms and so on for your site(s). And one of the features is the Big World Map, automatically coloured in according to the number of visitors. Bwa ha ha!

Unfortunately, like most online real-time statistics, it gets a bit addictive. Why has nobody from "Serbia and Montenegro" visited my website in the last three months? Everywhere else in mainland Europe has visited, so why not them? It's a little white void in an otherwise green chunk of map. Noth Dakota was another holdout that was bugging me a few months ago, but someone's finally visited, so this quarter's stats have the US totally coloured in (yaay!). Greenland not visiting I can forgive (almost nobody lives there), but what about Iceland? I seem to be missing six Central and South American states this quarter, including Bolivia, Paraguay and Venezuela - the Dominican Republic visited, but not Cuba. Are Cuba's visits logged? African coverage is a bit patchy, but improving around the edges. Iran's dropped off the map this quarter, but Iraq's still hanging on in there.

In the Far East, the last quarter's stats are missing Cambodia, Papua New Guinea, North Korea and Myanmar, and slightly to the West, I have a gap comprising Turkmenistan and the surrounding countries (including Iran). Nobody's visited from Madagascar this year. And Antarctica doesn't appear on the map. Other than that, just about everyone's visited in the last quarter, apart from Mongolia.

Mongolia in particular is beginning to bug me. It's a big white splodge on the map between Russia and China, and it sticks out something rotten. Clearly not enough people in Mongolia feel that my site is worth visiting. I am trying to not feel the wound too deeply ... perhaps I have not paid enough attention to the needs of the Mongolian theoretical physics community. Mongolia, I shall endeavour to do better. Thou shalt be mine!

Friday, 3 April 2009

Trigonometric Julia Set Images

The usual Julia Set images are generated by repeatedly running the formula z→ z² + c.
But there are other things that we can do to generate variations, like trying different powers of z.
One of the cooler variations is to replace the usual Julia formula with z c× f(z), where f(z) is a trig function. This was the method I used to create the (TAN-based) cellular and (SIN-based) circley fractals in the 1st March and 9th February blog posts.

Thanks to Pythagoras' Theorem, trig functions include terms, so there's a certain amount of crossover between the "conventional" and "sine" Julia sets.

Web-wise, priority seems to go to Paul Bourke and Tim Meehan for putting up a webpage on "Julia set of sin(z)" nearly ten years ago.

For those who want to see more, there are some more "sine Julia" and other "trig Julia" images on the website on three new pages, here, here and here. The third page shows how more complex and more strongly repeating versions of the more familiar Julia Set images (example above) appear within the "sine Julia" parameter set.

Some of the pictures are cool.