In The Blood

My leisure reading tonight was about Toxoplasma gondii, a unicellular parasite which infects mammals. It can replicate asexually in any mammal, but can only mate and reproduce sexually inside a cat.

Cats usually become infected by eating a prey animal in which T. gondii has spread into muscle tissue and formed dormant tissue cysts. The parasite then reproduces in the cat and is shed in its feces in the form of oocysts. If another mammal ingests the oocysts, the cycle starts again.

Alternately, non-feline carnivores can become infected directly by eating the tissue cysts.

Humans can acquire the parasite from exposure to cat feces. (Oocytes are shed mainly when the cat has first become infected, for about the first week or two, so kitten poop is more dangerous.) As omnivores, humans can also ingest tissue cysts in the muscle of another infected animal. Pork and lamb have the worst safety record.

But it was the story of an experiment which astounded me. In a Paris orphanage, 10% of the children had detectable T. gondii. After being fed rare steak and horsemeat for a year, the infection rate went up to 50%. Then rare lamb was added to the diet, which brought the infection rate up to 100%. The old, dark days of experimenting on orphans. It was 1965.

In most cases, there are no obvious symptoms of an infection, but sometimes people can have a severe reaction, called toxoplasmosis, which can be like a bad dose of the flu lasting four months.

Heating to 65 celsius will fairly reliably kill the parasites in their tissue cyst state, but cooking a steak “medium rare” or less usually means that the centre stays below 60 celsius. You might as well rub your steak with cat shit.

It has been found that rats with the parasite behave differently to non-infected rats. They have less fear and less aversion to the smell of cat urine. T. gondii achieves this by manipulating the epigenetics of their neurons, obviously an evolutionary adaption which makes the rat more likely to be eaten and the parasite passed on. It hasn’t been shown definitively yet, but some studies indicate that there are psychological effects in humans as well.


Space is Deep

When I first bought my satellite dish over seven years ago, it was a motorized system. You see, television satellites form a ring around the Earth, and the dish must point to the right satellite to receive its broadcasts.

I can’t quite get my head around the excact geometry of it, but my house is attached to the Earth’s surface at a latitude of 53.549 degrees. The satellites are in a ring over the equator, which is zero degrees, while the Earth’s axis of spin is 90.

Anyway, I think how it works out is that the motor has to be aligned at (90 – 53.549) to the horizontal, and then by rotating left or right, it can pick out a satellite.

Well, I got it to work. The wall of the house points a bit West of South, and I could use the motor to point the dish across an arc of satellites. I thought that the Western end might get me some North or South American channels, but that end seemed to be equitorial Africa. In fact, the satellites which serve a particular region don’t sit directly above them. For example, the UK’s Sky and Freesat come from a group of satellites directly overhead 28 degrees East, which is somewhere in the Democratic Republic of the Congo.

But I got the channels I wanted. Freesat for British television, and turning a bit East, Hotbird for Italian, both the state broadcaster RAI and the Berlusconi empire on Mediaset. Going further East, I could get all the way to Khazakstan. Oh, and there were loads of middle-Eastern channels in there, most of them about Allah.

After a year or two though, I became dissatisfied. It took about twenty seconds to turn from UK to Italy, which is a long time in TV. And I hardly ever watched Khazakh television. I took the motor on the dish out of circuit, and put a multiple-LNB bracket on instead.

The LNB is essentially the “receiver” facing a satellite dish. In theory, the dish focusses the beam to one point, which is where you place your LNB, but in reality, it’s not that simple. The beam from a satellite that’s a bit to the left gets focussed, sloppily, more-or-less, to a spot on the right, and vice-versa. If the signal is stong enough or the dish large enough, you can get working television off more than one LNB.

The standard switch for multiple LNBs can handle four. I put up three. One for Freesat, which is a strong signal over the British Isles, and would work even off-centre. About centre, I pointed another at Astra, which has a load of German-language channels (I understand a bit of German) and a few French (my French is a little better than my German). Although the majority of French television seems to be encrypted on the proprietary Canal Plus system, and I can’t receive it. A little bit East, one LNB got Hotbird, with the Italian channels I wanted.

Unfortunately (maybe), after a couple of years, the Italian Mediaset channels on Hotbird went encrypted onto the Tivusat system. If you live in Italy, and have a tax code, you can get a free decoder card. Outside Italy, there are ways and means, but they all cost money. I shrugged and carried on.

Then, some months ago, I noticed that there is lots of Italian television on a different satellite, one that is physically above the British Isles at 5 degrees West, but points East to Italy. There is a host of regional RAI stations, and even the Mediaset channels are broadcast unencrypted. But my dish has to be pointing the other direction to see Freesat. (In fact, the Freesat sat is overhead Italy and the Eutelsat one is above the UK. What’s going on?)
There was a slight chance that a fourth LNB could receieve Eutelsat 5 if stuck far enough off centre. They’re only a fiver, so I bought one. And… it didn’t work. After a couple of hours up the ladder (I don’t like heights) I couldn’t get anything, and gave up. I slid the LNB along the bracket until I got a strong signal from an other satellite, any satellite.

This turned out to be Eurobird 9A, with about fifty free television channels on it. Hungarian and Swiss in the majority, but also some Chinese. The People’s Republic of China broadcasts across the world in different languages. I have English, French, Russian and Arabic.

As it happens, there’s an Italian drama tonight on Hungarian television, dubbed into Hungarian, and I don’t understand a word. I can’t even make anything of the programme info. There’s a priest in it but he’s not Don Matteo. Oh wait, I searched on-line for the title — “Rózsák Harca” — and it says “Tuscan Passion”. IMDB reveals: “A story of murder, conspiracy and secrets but above all about a great love story; Tuscan Passion tells the story of an impossible love between Aurora Taviani and Alessandro Monforte. Both belong to enemy families and both are divided by a history of blood and mystery. ”

So just another day in Tuscany. It went out on Mediaset in Italy, and I don’t see that any more.

The Price Of Drink

The British Medical Association in Northern Ireland have jumped on the bandwagon (but certainly not on the wagon) calling for a minimum price per unit of alcohol in drinks. Fifty pence, is what they suggest.

The NI Chairman of the BMA, Dr Paul Darragh, is quoted in the BBC report as claiming that there is consistent evidence that alcohol consumption and rates of alcohol-related problems were linked to the cost of drink. Well, that is flat wrong. There is no evidence.

Usually, when pressed on this point, campaigners will refer to a report from the Sheffield Alcohol Research Group (at the University of Sheffield). Sounds impressive, doesn’t it? They must be proper scientists, being at a university and everything. Actually, anything I’ve read from them is absolutely not science. It’s not science to assume first that increased alcohol prices do improve health, and then use circular reasoning and cherry-picked data from other publications to “prove” the original assumption.

A couple of authors from the Adam Smith Institute (an economist and a statistician) published a paper ripping the Sheffield methodology to shreds. It’s worth reading just the executive summary to get a flavour of the arguments. It finishes “We conclude that predictions based on the Sheffield Alcohol Policy Model are entirely speculative and do not deserve the exalted status they have been afforded in the policy debate.”

Excessive alcohol consumption causes both social or health problems. Binge drinking, particularly by young people, is notorious for its effects on society. The television people always find it easy to get footage of late night antics: fighting, falling over, throwing up in the gutter, fornicating in the flowerbeds. People who do that sort of thing are harming their health, of course, but for most of them it’s just a phase they go through. They grow up and become boring.

Those who get hooked on alcohol and can’t give it up are in a different category. It would be compassionate to try to help them, never mind the additional health costs they incur and the impact on our taxes.

What effect would a modest price increase (i.e. one that the politicians could get away with) have on these two classes of problem drinker? Is price a major factor in people’s decision-making? What about the young people staggering home or fighting for taxis; have they all just come out of the cheapest, coarsest drinking dens? Not in my experience. In fact, quite likely they’ve been in a flashy club where the drink prices are substantially inflated.

Allegedly, the youth drinkers start the night by drinking cheap supermarket booze at home, but I’m not sure that this affects the argument. The objective is usually to get hammered, and whether you have nine drinks at home and one in the club or vice versa seems to make no difference.

I don’t know if you’ve ever known someone in the second category, the real alcoholic. Without help, they literally can’t stop drinking. Food, shelter, clothes — everything is secondary to getting the next drink. Do the unit pricers really think that an alcoholic will sit down and rationally decide “Well, with the price increase, alcohol will take a larger proportion of my income, so I must reduce the amount I buy.”?

If I was of a conspiratorial bent, I’d suspect that the whole idea of a legal minimum price per unit was a plot by the supermarkets, who would do very well out of it. Why isn’t anyone arguing for a price increase by increasing the tax and making it depend on the alcohol content? I don’t think that would help either, but at least the additional money could be spent for our benefit, not for fattening shareholders.

William Hogarth, Gin LaneBut the real thing that narks me about the minimum price idea is the ugly underlying assumption that problem drinking must be a disease of the poor. The proposal is based on the notion that 50 pence per unit will matter to the people with the problem: in order for it to make any difference, it must represent an appreciable percentage of their income. That is, the poor.

As I said at the beginning, the doctors are the latest group to call for a minimum alcohol price. As it happens, out of all employment groups, doctors have one of the highest incidences of alcohol abuse and dependence. But doctors are paid well, very well. Will a minimum price save the alcoholic doctor? I think not.

Walk The Walk

high-heels dotsAround the turn of the year, probably a slack news period, a scientific publication got an unusual amount of news coverage. No, it wasn’t the discovery of a new boson, or a habitable planet circling a nearby star. This one was titled “High heels as supernormal stimuli: How wearing high heels affects judgements of female attractiveness” []

I’m always envious of researchers who can make a living carrying out such work. I remember one study which measured the amount of bare flesh in a nightclub and compared it to the owner’s fertility cycle. That one showed that women do show more skin during the most fertile time of the month, but only if they are in permanent relationships, but out without their partners. You can draw you own conclusions.

Still, you have to be sceptical, particularly if there is a claim of some evolutionary origin of a particular behaviour. That’s almost always stretching the evidence much too far, and anyway, human behaviour is too complicated for a neat just-so story.

That thing about high heels though. It’s an issue which has perplexed and slightly embarrassed me for years. I’d already guessed the same conclusion as the authors of the much-reported paper: that the high heel effects some kind of “supernormal” sexual signal. That is, biological systems seem to work on the basis of “if X is good, then XX is better”. Research (mostly on animals) has shown that exaggerating a stimulus, even well past the point of naturalness, can generate a heightened response.

high-heels graphBut it’s not clear exactly what factor is in operation. The research paper was investigating walking, and reported a “shorter stride” and “increased rotation and tilt of the hips” for high-heeled as opposed to flat shoes. From my own observations, I’d add that the static posture is different as well, all the way up to the shoulders; and the silhouette is changed subtly. Which of these things –some? or all? –change our perception?

I say “our” deliberately. In the research, both men and women rated walkers in heels more attractive, even though they were only seeing a pattern of light spots on the joints of the subject. A different set of viewers were found to be twice as likely to guess that the walker in flat shoes was male, even though all subjects were actually female.

So I guess it’s settled. Heels do something to make a woman more feminine and more attractive. It’s not surprising that they are the only item of apparel to be consistently “in fashion” for hundreds of years.

high-heeled sandalI think it was Sigmund Freud who came up with the concept of “fetishism”, where sexual attraction derives from an object, rather than a person. The liking for high heels was well-known in his time, and his suggested explanation was that we experience our first sexual feelings before we can even walk, when we are crawling around among the ladies’ feet, and henceforth always associate sex with Victorian buttoned boots. But Sigmund was like that: he just made stuff up without a shred of evidence behind it.

I’m not old enough (honest) to have seen high-heeled buttoned boots as a baby, but now I think they can be quite sexy. And other high heels too. That’s the source of the mild embarrassment which I mentioned at the beginning, because if I’m honest with myself I have to admit that some kind of transference has occurred in my brain. The shoe itself, completely separate from the wearer, triggers a response.

I’ll quickly point out that it’s only a little response, only a mild dose of fetishism. I’m sure a brief internet search would reveal sites showing a complete obsession, although I suppose that’s true of practically everything. Anyway, I don’t judge. Sexual attraction is never based on logic or good sense in any of us.

Happy Birthday, Alfred

The name of Charles Darwin is firmly attached to the science of evolution, but if it hadn’t been for one coincidence, maybe someone else would have been more famous.

(I’ve noticed that the religious nuts who deny the occurrence of evolution often use the term “Darwinism” instead of “evolution”, as though it’s easier to dismiss it if it’s the theory of one man. That’s wishful thinking though.)

It’s not entirely unfair that Charles Darwin gets the credit. Some of the ideas on evolution had been discussed for quite some time previously (his own grandfather, Erasmus Darwin, had written a treatise on evolution, The Temple of Nature. In the form of a long poem.) But Charles Darwin was the first to come up with a coherent theory which included natural selection.

387px-Darwin-Wallace_medalThe Darwins were rich, and Charles never had to work for a living. He went to the same university as I did, except that I actually got a degree. His famous voyages were paid for by his father. But Charles was a meticulous observer and an intelligent and talented scientist. When he returned from his travels and wrote up a synthesis of his theories, that was pretty much the theory of evolution worked out. It was done by the early 1840s.

He didn’t publish though. Perhaps he was too timid about the possibility of a controversy, perhaps desperate to do more studies to build up the evidence. His close friend, the geologist Charles Lyell, was familiar with Darwin’s ongoing work, and in 1855 spotted a paper published by a young naturalist in Borneo, Alfred Russel Wallace, which showed thinking along the same lines.

Wallace wasn’t rich. He’d had to drop out of grammar school when his family could no longer afford it, but learned surveying and map making as an apprentice under his brother. He worked in various jobs, in surveying, civil engineering and teaching, but at the age of 25, left for Brazil to become a professional collector of natural history specimens to sell to armchair naturalists in England. The business was never very successful, and Wallace was always on the brink of bankruptcy, but he learned a great deal and became a respected scientist. (Or at least, reasonably-well respected, for he was not, of course, a gentleman.)

Wallace sent Darwin his new paper on the theory of evolution in 1858, asking for his advice on whether it was fit for publication. The content was so close to Darwin’s own unpublished theories that it put him in a dilemma. If he did the decent thing and recommended that Wallace’s paper be published (because it was top-class work), then Darwin would lose priority and could not claim to be the discoverer of evolution by natural selection.

If, on the other hand, he now rushed his own theory into print first, the scientific world would never know how much was original and how much had been inspired by Wallace.

At the suggestion of Lyell, a solution was reached where Darwin summarised his own material into a new paper, and both his and Wallace’s were published together as a joint presentation to the Linnean Society.

If Wallace had decided to consult someone other than Darwin, or had submitted his paper for publication directly to one of the scientific journals, then it might have appeared in print before Darwin knew of it. We might today talk of “Wallace’s Theory of Evolution”.

Alfred Russel Wallace, OM, FRS (8th January 1823 – 7th November 1913)

Oh My God

galaxy sphereThe universe is full of fast-moving sub-atomic particles. Even a staid, middle-class star like our Sun generates a stream of energetic particles which we occasionally see interacting with the Earth’s magnetic field and atmosphere in the form of Auroræ.

Even higher-energy particles arrive from outside the Solar System, and when they crash into our atmosphere they generate a tiny flash of light. The University of Utah operates one telescope system specifically to observe these flashes, because the original particle’s path and identity can be deduced, giving the astronomers information about what is happening out in the universe.

But one night in 1991, the scope detected a flash which could only have been created by a particle with 3.2×10²° electron volts, about forty million times more powerful than the Large Hadron Collider. This particle came to bear a name based on the astronomers’ first reaction. It’s called the “Oh-My-God Particle”.

You’ll know from Special Relativity that nothing (with mass) can be accelerated to the speed of light, but by adding more and more energy, you can edge ever-closer to light speed. Well, the OMG Particle, if it was a proton, would have been doing 0.9999999999999999999999951 of light speed, or to put it another way, in the time light crossed a light year of distance, the OMG would cross a light year less 46 nanometres.

Back to Special Relativity: obviously it takes light a year to travel a light year, and likewise for the OMG (minus 46nm). But for the particle itself, time dilation occurs. Time       actually       slows       down. From the OMG’s point of view, time is slowed so much that the travel time is much shorter. Much, much shorter: 100 microseconds.

If you could accelerate a spacecraft to OMG speeds, you could visit the centre of our galaxy in 3 seconds, or neighbouring galaxies in a few minutes. I can’t see how such speeds will ever be possible for a solid object like a spaceship, but maybe one day we’ll use more modest relativistic effects to make interstellar flight feasible.

The problem that the OMG presented the astronomers — and it still hasn’t been solved — was that when they traced the path back, there was nothing there. Nothing which could plausibly have generated such huge energy in a particle. In fact, because all of space is filled with the Cosmic Microwave Background (CMB) radiation, energetic particles interact with it and are eventually slowed down. The maximum distance that OMG could have travelled is about 50 megaparsecs (160 million light years), which implies that there is a fixed volume of space out there within which it must have originated, but when you investigate: nothing.

Since OMG, there have been about 15 additional detections of its brothers and sisters, but there is still no generally-accepted theory to explain what they are and where they come from. My own favourite is that the universe contains “topological defects”, where the actual geometry of space-time has a discontinuity or flaw. Postulated one-dimensional defects are called “cosmic strings” (nothing to do with string theory) and would be a rippling crack in space-time, the thickness of a proton, but hundreds of light-years long. If a string was to thrash around and loop back on itself, the parts would split off, with a huge release of energy, more than enough to generate OMGs.

Coming Out

Today, 10th October, is World Mental Health Day, a concept instituted 20 years ago “for global mental health education, awareness and advocacy”. This year’s theme is specifically on depression, which, according to the World Health Organization, was ranked as the third leading cause of the global burden of disease in 2004 and will move into the first place by 2030.

So this would be a particularly good time to reveal something which only a few very good friends know about me: I’ve been fighting depression for all of my adult life.

I Has A SadDepression takes two general forms. In the less common type, “bipolar affective disorder”, sufferers have wild mood swings, from deepest depression to crazed mania. Stephen Fry is well-known for being affected by this form of the disease. But more often, there is no manic phase, just recurrent episodes of depression, which can vary in severity. It can be referred to as “unipolar” or “episodic” to distinguish from the bipolar syndrome.

I’ve found that non-sufferers (or let’s call them “normal people”) just don’t understand depression. They’ve been very sad in their lives themselves, or experienced grief, and imagine that depression must be a bit like that. It isn’t at all.

I’m only speaking from my own experience, but depression seems to me to be more like a mental paralysis than any kind of sadness or just feeling low. Doing the simplest things requires a huge effort. A common other symptom is having very low self-esteem, and perhaps feelings of worthlessness, but I’ve never had that. I have two alternate explanations for this difference. One, I wholeheartedly accept that depression is an organic disease, and nothing to do with my self-worth (just as I wouldn’t feel it was my fault if I caught tuberculosis). Or second, maybe I just love myself too much.

The episodic nature of the disease means that I have good times and bad times. During the more severe spells, I cope by cutting down activities and socializing to a minimum. Today, I’m fortunate not to have to get up and go to work every day, but when I did have to do that, I mostly got by, and only rarely invented a physical sickness to cover a day or so off.

So my depression is definitely not the most severe category, because I can continue to function, albeit with some impairment. But some people are hit much harder by it, and practically “shut down” and withdraw from every aspect of normal life. A small percentage decide that they just want it all to stop, and take their own lives.

Friends and relatives can help a lot, but it’s not easy, because depressives are in a state where they interact badly with others. If your friend is depressed, it can help to be gently persistent. They’ll turn down a social event, for example, but might concede after a little encouragement. Or not. Don’t be offended by a refusal, and if you care about someone, don’t give up on them.