Friday, September 25, 2009

That so-called "Anglo-Saxon" treasure could have been of genuine British-manufacture

I'm going to stick my neck out here. Who's to say that the fabulous hoard of gold and silver craftwork, unearthed by that bloke with the metal detector in Staffordshire, was produced by Johnny-Come-Lately Anglo-Saxon settlers?

 Just 9 of some 1500 so-called "Anglo-Saxon" artefacts - a stupendous find,  regardless of provenance

OK,  so we are supposed to be proud of our admixture of Anglo-Saxon and other genes. We are supposed to take pride in being an allegedly mongrel race  (hybrid vigour an' all).

But have your read your Stephen Oppenheimer?  He's the Oxford scholar who analyses modern DNA to trace our genetic roots. I blogged about his claims some 3 years ago.  Oppenheimer rejects the idea that Anglo-Saxons supplanted the native Brits, sending us scurrying to the Celtic fringes. Oppenheimer reckons that the native Brits pre-dated the Celts, and indeed resisted numerous waves of invasion - the Celts, the Romans, the Anglo-Saxons, the Normans, stubbornly staying put, and surviving - either by putting up resistance, or by assimilating the invaders.

Oppenheimer reckons that native Brits are derived from Basque migrants who recolonised Britain some 15,000 years ago after the last Ice Age, crossing the then still existing land bridge between the Continent and England.

So why is the treasure being described as Anglo-Saxon? Who's to say it is not native British - or, less probably, Celt?

OK, so it was discovered in a Staffordshire field, in central England, and is reckoned to be 7th century, when that part of England was in the Anglo-Saxon kingdom of Mercia.  But that does not mean that it was Anglo-Saxon treasure. It may have been of native British manufacture, possibly from the era (mythical or otherwise) of King Arthur, Camelot, and the Knights of the Round Table. It may have been taken from our dead warriors on the battlefield  as war booty - or maybe our knights buried their finery (purely for show!) before facing the invader in battle wearing the equivalent of combat fatigues.

What's the evidence that Anglo-Saxons ever produced such exquisite artwork? I thought they were practical types, more concerned with clearing forest, ploughing, agriculture and animal husbandry? Their efforts went into producing axes and ploughs - not fine gold filigree ornamentation.

Yep, I'll put my head on the block. The "experts" have got it entirely wrong. It's not Anglo-Saxon treasure. It's British treasure. And no, I don't mean Celtic treasure - although that gifted if mercurial folk did produce fine arts and crafts - and are arguably more highly regarded in that respect than the Anglo-Saxons.

Nope, I reckon the treasure was produced by native "aboriginal"  Brits,  of Basque-derived stock  according to Professor Oppenheimer - the true Brits - the ones who re-settled the British Isles, and who have managed to survive and prosper despite waves of immigrants seeking a better life. Britain's geography permitted co-existence within probably quite confined geographical areas - a few hundred square miles for example - which could be a little as 20m x 20m-  thanks to our varied topography, the (then) more abundant forest cover, and, dare I say it, mutual tolerance and/or respect between native and newcomer. There was room for everyone who was prepared to work, and to "live and let live" - the British way.  Britain was, if you like,  the "New World" of the first millennium, once the Romans had left.

I repeat: the experts may have got it wrong. One cannot assume it is Anglo-Saxon treasure. It could well have been the exquisite handiwork of native Brits who  succeeded in maintaining their genetic, ethnic and cultural identity over thousands of years - standing firm and finally expelling - or assimilating-   the Celts, Romans, Anglo-Saxons,  Danes, Vikings and Normans.

Update  Sat 26 14:31 : See the Telegraph article with its 23 comments - at the time of writing.

The "Staffordshire  Hoard" now has a wikipedia entry

Thursday, September 24, 2009

No genuinely free water on the Moon, it would seem...

The ambiguity of "free" in my title is deliberate. The traces of water detected by that inspired Indian lunar probe are not of course  free water, in a chemical sense, but chemically-bound, non-wettening "water".

 Is that a water-diviner in his hand? If so, then happy-hunting..

Even my non-scientific wife was quick to realize that, watching last night's news, even if the media reports elsewhere conjure up visions of future moon colonists tapping into an abundant supply.  Moonshine!

Being chemically-bound, whether weakly or strongly,  it's hardly free for the taking either. The expression "getting blood out of a stone" springs to mind.

Here's what I sent last night to the Times in response to that  trumpeting  headline re there being a litre of water per tonne of lunar soil. (One feels that "water" should have been enclosed in quotation marks in the Times's article).

To say there is "water" on the Moon when it's there as the hydroxyl radical/ion is a little misleading, as others have pointed out. It's like saying that farmer's lime, calcium hydroxide, is a potential source of water. True, in a manner of speaking, but you would have to get it red hot to drive off water as steam, as in lime-furnaces, and then have a means of cooling and condensing to get liquid water. It may sound easy in principle, but the practical aspects of attempting this on the Moon are formidable. One would need an abundant supply of energy - probably tens or hundreds of square metres of solar panels to generate megawatts of electricity.

Why not get the Sahara green first - to create biomass and reduce CO2? Huge problems to overcome, yes, but if we can't lick that problem, what hope is there of colonising the Moon or Mars on a realistic timescale?

September 24, 2009 11:10 PM BST on

"Hydroxyl", note, is not a molecule, as the report would have one believe. Being simply OH, with an unpaired electron, it would be a free radical, with no independent existence, and a lifetime of seconds at most if generated in the atmosphere by, say, cosmic ray bombardment. Most "OH" in rocks is, of course, present as negatively-charged hydroxyl ions, accompanying positively-charged metal ions, eg aluminium.

Aside: well done, btw,  Times for finally adding a time and date stamp to readers' comments,  and for a much-speedier moderation than before. The BBC-style facility for expressing approval is also cute.  It even survives cut-and-pasting here, apparently as a live-link - see the blue font above!  Shame though that one's comments are not accessible to search engines. The world wide web depends on linking, you know, if only for information-retrieval. Vanity has nowt to do with it, of course...

Update: Friday 15:15 pm.  Had some further  thoughts on the inconclusive nature of the chemistry after reading the New Scientist's feature:  Have just sent the following:

"Hmmm. So the signal could have come from water or from the "OH molecule". Leaving aside the faulty nomenclature - OH is not a molecule, but is either a free radical if electrically neutral, or a negatively- charged ion -  it seems a bit of a liberty to lump together two entirely different chemical species in this manner. The discovery of  H2O would indeed  be exciting, even if strongly adsorbed to minerals. But "hydroxyl", presumably as mineral hydroxides, would be an entirely different matter, requiring somewhat high temperatures in most cases if  desiring to drive off molecular water, which would then have to be cooled and condensed. Most of the hydroxides of predominant minerals in the Earth's crust - magnesium, calcium, aluminium etc-  hang onto their oxygen and hydrogen quite firmly, needing red heat or higher to dissociate into oxides and steam.

So it's somewhat premature surely to report that "water" has been discovered. On the basis of available evidence, none of which can be described as "hard",  what's been discovered are  oxygen atoms that are bonded to one or possibly two hydrogen atoms with a strong attachment to a mineral matrix given they are able to survive solar heating in a vacuum. Alternatively, and less usefully from the point of view of harvesting lunar water, the signal is picking up a temporary association, ie  the turnover model, which would explain why the discovery did not come earlier from study of Apollo-mission rocks"

Update  Sep 25 21:17 : See also "How could astronauts harvest water on the Moon" - latest article in New Scientist.

Flightless birds: why are they found on islands?

Whilst on holiday (see previous post) I've been reading Jerry Coyne's excellent "Why Evolution is True".
Here's a tip: next time you encounter an advocate of "intelligent design" or, perish the thought, creationism, ask them if they've read his book  - or something comparable. Ask if they know about 'devolution' (my term ) which is the loss of function, with vestigial traits still visible - like that  otherwise inexplicable "floating"  pelvis and hind limb of the whale.  If they haven't, then refuse to enter into any discussion - probably futile in any case - until they have apprised themselves of the impressive marshalling of evidence in Coyne's book.

I should probably stop here - not presuming to be on anything like equal terms with someone who has spent his entire career researching the mechanisms of evolution (yes, the latter is possible, after a fashion, using his experimental model of fruit flies with their relatively short generation times). But I can't resist floating an idea that may or may not be codswallop. It concerns "flightless birds" - an example of that so-called 'devolution'.

The kiwi (NZ) - archetypal flightless bird

Here's Coyne's rationale:

"The long and the short of it is this: flight is metabolically expensive, using up a lot of energy that could otherwise be diverted to reproduction. If you're flying mainly to stay away from predators, but predators are often missing on islands, or if food is readily obtained on the ground, as it can be on islands (which often lack many trees), then why do you need fully functioning wings? In such a situation, birds with reduced wings would have a reproductive advantage, and natural selection could favor flightlessness. Also wings are large appendages that are easily injured. If they're unnecessary, you can avoid injury by reducing them. In both situations, selection would directly favor mutations that led to progressively smaller wings, resulting in an inability to fly."

Well, maybe, but wings confer such an extraordinary advantage over us terrestrial landlubbers that one has to seek an equally extraordinary reason why birds would divest themselves of such an advantage - even if  in thrall to random mutation and natural selection.

Here's my explanation - for what it's worth.

Suppose the first bird to land on an island had been blown way off course by strong winds, and had landed exhausted on its new home with abundant plant life and insects, but no snakes and other reptiles, or other predators- notably birds and mammals. Suppose too the bird had found a mate earlier, and was carrying eggs, duly laid in the new home.

The fledglings would have developed into fully-grown birds in due course. What then? Would they have stayed in their place of birth - or would they have been adventurous, and ranged further and further over the ocean in search of their more 'natural' habitat, ie that imprinted on inherited memory from mother?

Those that explored further afield might be fortunate and make landfall. Alternatively, and more probably,  they sadly would not make it, and would fall exhausted into the sea,  or hopefully perhaps turn back in time and return to their island home-sweet-home.

Over the millennia, natural selection would favour birds that were content to "stay put". Mutants that had progressive loss of flying ability would gradually predominate. Flight-capable birds would continue to suffer attrition, at least where the island was concerned. In the absence of predators, the flightless mutants would gradually displace the gypsy wanderers, provided there was sufficient food available at ground level - seeds, insects etc.

Maybe Mother Nature pioneered the joys of indolent vegetating, with old birds and/or their partners marooned on islands,  long before late middle-aged expatriate human beings arrived on the planet...

Monday, September 7, 2009

Sciencebod takes a late summer holiday

Yes, having spent most of the summer looking after a friend's house in Bratislava - complete with resident cats - it's time to have a touring holiday,  with no bowls to be re-charged morning, noon and night.

Where are we going?  Well, here's a clue. These structures are megalithic (which sounds technically savvy until you realise the literal meaning - "big stones"- which is hardly a giveaway.

We'll work in a visit to those" big stones", then travel north and hop across the straits to another more mountainous island. I've been sampling its beer, which recently appeared locally.

Chestnut flour is a major ingredient of the brew, we are told.  It's not bad at all,  with a well-defined malty presence, but maybe a tad too strong for my liking (6% alc).

If our various hotels all deliver on their wi- fi promises, I'll be able to keep an eye on the science news, and try to post a short report on anything that looks tasty. There are also a couple of posts in draft that could be fleshed out if rainy weather sets in - which is not impossible in mid-September, even in a location noted for its sunny climate. Will report back in a couple weeks - if not sooner.

Update  24th September

Am back from a fascinating 13 night recce of Sardinia and Corsica.  Visited the world-famous Su Nuraxi site at Barumini (see first piccy above) , about 50km north of Cagliari - which thanks to an officious and frankly sub-standard local guide was a mixed experience.

Here is the lady guide who not only insisted we join her group, despite her not speaking a word of English, but specifically prevented us from tagging along with the other guide whom we later heard using both English and Italian.

Reminder, young lady: Barumini is a UNESCO World Heritage site. To accept a question in English, and to reply in Italian is just downright inconsiderate, not to say perverse, especially when your colleague(?) was talking fluently in both languages.

Su Nuraxi? To give some idea of its age, it was abandoned  by its inhabitants, about whom we know next to nothing, in the 6th century BC. Prior to that, it had been occupied for millennia!

Random - and irreverent - thoughts on the British Science Festival

 John McCririck: missed his vocation as an SC (see below)?

Uh, uh.  It's that time of year again.  With the first chill nip of autumnal air, and the sight of new back-to-school satchels, or their modern-day equivalent, the UK press should now be going cold turkey on its silly season reporting.  But our esteemed MSM eases itself back into "business as usual" mode gently.  Temporary methadone maintenance is provided by the annual September shop-window for that charming if somewhat quirky organization - the British Association for the Advancement of Science.

Oops, I'm showing my age. It's abandoned that 19th century name,  conveying as it did an earnest desire to improve the scientific literacy of the muddled masses - and so cruelly satirized by Charles Dickens as "The Mudfog Society for the Advancement of Everything".

It now wishes to be known simply as the British Science Association.

I see that BBC correspondent  Sue Nelson is on the spot in Guildford for this year's jamboree - it's using the University of Surrey campus - and  is being suitably non-overawed by the occasion. Here's a delightful tongue-in-cheek equation she has "derived"  by which she rates  SC, the colourful "Science Communicators" she encounters:

H = the number of hand gestures
J = the brightness of a jacket
A = the number of times someone says "amazing"
F = the amount of facial hair
Well, we've had some quite memorable and sometimes colourful characters in front of our TV screens -  Sir Patrick Moore, Magnus Pyke,  James Burke. Maybe John McCririck should be drafted in, if only for his stratospheric SC rating (see graphic :-)

So what kind of science will be on offer this year?  Is science still capable of capturing the modern imagination?  Can we safely assume there will always be another "big idea" along soon, comparable to the DNA double helix,  genetic engineering, stem cells, plate tectonics, superstring theory etc etc. Or has science become so infected with quantum uncertainty that it is now dismissed as telling us more and more about less and less?  Will this year's Science Festival give us a taste of new insights, or is it a forlorn exercise in window-dressing, concealing an increasingly bare cupboard and shelves?

  (I choose my words carefully, having scanned the list of honorary members and sponsors, discovering names of people whom it would not be wise to offend, including an ex-employer who is now Something Big in Science Policy-Making.)

Religion seems to be flavour of the year at this year's Science Festival,  if the Telegraph Science page is reliable as a straw in the wind.

Well, it makes a change from  "Why future Moon colonists may keep bees" or similar  (OK, so I made that one up, but you get my drift).

Speaking of the Telegraph,  it seems to be on a religious kick at the moment. It's even spilled over onto its so-called Science Page. See the recent article by Christopher Howse:  "Do you Believe in Angels?"

 That "angels" feature incidentally provoked a quick riposte from your sciencebod   ;-)

"And to think this is the latest post in the DT's Science section! Is nothing sacred?"

One "getagrip" responded to this and similar sentiments with:

"The word angel occurs 194 times in the Bible.  My challenge to all those who have written sceptic comments is to go and read it for yourselves or just remain ignorant bigots."

Well, I guess that's  progress of sorts - the bible-quoters are now fighting fire with fire - quantitative data no less!

Incidentally: there are 64 occasions on which miracle(s) appears in the Bible. There's even a website for the benefit of the new breed of  Biblical number cruncher.  The most commonly used word,  not surprisingly, is "and"...

Update:  Scientist Lord May attacks BBC rejection of Planet Earth day

Thus reads the headline in the Times. It also needs to be read in conjunction with Lord May's somewhat  whimsical advocacy in today's Telegraph for a return to a God-fearing society (tongue-in-cheek methinks because he himself is described as a non-believer). Why? Because nothing less than religious commitment is likely to make people see sense on the need for urgent steps to prevent AGW.

Hmmm. There are some real characters in the upper echelons of the UK Government science establishment. Lord May, an ecologist, with wide-ranging interests and expertise in biodiversity etc,  was Chief Scientific advisor in the Blair government, and was President of the Royal Society for 5 years.  

My response to the Times:
"If I were religious, which I'm not, I'd be somewhat offended by the sight of a non-religious person (described elsewhere as an "atheist"), no matter how distinguished, telling me that my God was maybe a Good Thing after all, provided He is perceived as waving a big stick at climate change sceptics, bringing them to order.

I personally am slowly coming to accept at least some of the AGW arguments, but that's not because of politicians preaching about a so-called "scientific consensus" but in spite of them. Nothing is better guaranteed to turn off the enquiring mind than the claim that the time for debating is over, and that one must now obediently accept the nanny state's medicine like a good obedient citizen."

Sunday, September 6, 2009

Fame at last!

 From today's New Scientist homepage

Climate will cost much more than UN thinks

"Have you ever known anything to cost less than originally forecast? That would break an immutable law of grant-seeking." sciencebod

Here was my comment in full:

"Have you ever known anything to cost less than originally forecast?

That would break an immutable law of grant-seeking. Estimates are always pitched low initially, so as not to frighten off the fund-givers. They are then gradually and expensively racked up to take into account a host of hitherto unrecognized factors that no one could possibly have forseen, because their eyes were deliberately focused on the far horizon, and nothing so immediate and mundane as the nitty-gritty.

The maximum final/initial ratio is reckoned to be in the region of 3:1 for seasoned pros, who know how far they can push their luck. One notable exception are the organizers of the 2012 London Olympics, who are pushing the envelope, as they say, up into new unheard-of brass neck ratios. Hidden costs, like VAT for example, which no lobbyists, least of all at ministerial level, could possibly have forseen."

Saturday, September 5, 2009

To global warming sceptics - other reasons for cutting fossil fuel consumption

 London photochemical smog - it begins with the burning of fossil fuels

Here's an article I would strongly recommend. It's written by Geoffrey Lean in today's Telegraph.
The strap under the headline  ("How's your carbon-footprint doing?") reads:

Cutting emissions of carbon dioxide makes sense even if you don’t believe in climate change.

And here is a quotable quote:

"Carbon dioxide emissions are turning the seas acid, and dooming the coral reefs, quite apart from their effect on global warming. Reducing fuel use would also cut other forms of pollution, such as the tiny particles, mainly from car exhausts, that EU research concludes kill some 30,000 Britons each year – shortening average life expectancy by six months – and the nitrogen dioxide which is increasingly implicated in the asthma epidemic that now afflicts one in seven British children... 

 ...   driving cars less reduces congestion and the building of new roads through the countryside. Walking and cycling are good for your health, as is eating less meat. Using water economically – and thus reducing the vast amounts of energy needed to pipe it around – helps tackle the water shortages threatening areas like the South East. Recycling paper saves trees. And so on."
Note regarding that nitrogen dioxide: it's a real insidious nasty. Why? Because the nitrogen does not come from the fuel, unlike, say, the sulphur in that other air pollutant - sulphur dioxide.  So there is no point in scientists seeking a low-nitrogen petrol or gas.  With the exception of coal,  fossil fuels have virtually no nitrogen to start with!

The nitrogen comes from the air. What happens is this: when our fossil fuels burn inside engine cylinders, gas boilers etc, the high temperature make some of the nitrogen  (normally considered chemically inert) to combine with oxygen to make nitric oxide, NO. That colourless gas then combines with more oxygen on cooling  to form nitrogen dioxide, NO2. That gas is no doubt responsible for most of the yellowish-brown colour of city smogs, and is highly damaging to our airways and lungs. NO2 is thought to be a major contributor to the increasing incidence of asthma attacks.

Here is a graphic showing the multiple sources of polluting nitrogen oxides in our air.

Source - same Camden link as above.

 So wherever you have fossil fuel being burned, you have toxic polluting nitrogen dioxide being formed. Sadly you can't have one without the other - no one's been able to find a way of uncoupling the two.

What a shame that nitrogen dioxide is not soot-coloured instead of being a light yellow-brown. Had it been so, one suspects that our burning of fossil-fuels would be much curtailed - voluntarily! 

Afterthought: Some of the pollution by nitrogen dioxide has admittedly been cut by the introduction of catalytic converters, now compulsory in new vehicle exhaust systems.  The platinum and other catalysts have been cleverly chosen to make nitrogen dioxide react with another dangerous pollutant -  carbon monoxide- to form non-injurious end-products:

nitrogen dioxide  & carbon monoxide react together on catalyst surface, and are converted to   nitrogen  & carbon dioxide

It helps, but there's still a hazard from NO2, which is not surprising since it's not just internal combustion engines that create it - see pie chart.

( Apol's btw for the divider lines. Not sure where they came from - some kind of formatting glitch)


Friday, September 4, 2009

Yes, it is theoretically possible to see into the past (to be taken with a pinch of salt)

 Safely home - and receiving calls?
It being a slow news day - at least where the science is concerned-  I was going to take a break. But I had an idea while shaving that I must share with you, dear readers.

They say it's impossible to travel back in time, right? I'm sure I don't need to remind you why (like what's stopping you from locating Hitler's grandfather,  pushing him under the wheels of a stage coach, thus preventing Hitler from being born? ).

But suppose I told you that it's theoretically possible to see what really happened in the past, say at Dallas, Texas in 1963, or to the Marie Celeste?  You'd say rubbish, would you not? Certainly I would have, up until a couple of hours ago.

Well think again.

Now you've heard of those distant exoplanets, right? They are outside our own solar system, orbiting their own stars. We know they are there - a few hundred have now been detected.  No, we can't see them directly, but they can be detected  by the small amount of light they block out when they transit their sun.

Suppose now there's an exoplanet called Zog, and that it is, let's say, 25 light years from Earth (our own Sun, by comparison, is 8.5 light minutes away, and the nearest star, Alpha Centauri, about 4.3 light years away).

Suppose the Zogians are far more advanced than we are, technologically, and have not only detected our presence, but have gone on to develop high-resolution video ( unlikely, but not theoretically impossible). Supposing Earth's history is being stored on Zogian video tape right now.  What it records right now is what took place on Earth 25 years ago - because that's how long it took the light to travel from Earth to Zog.

Now suppose we find a way of sending a radio message to Zog, saying "Hello neighbours. Please could you include us on your subscription list for Earth video footage?"  OK, so  it would take 25 years for Zog to  receive our message, and  - if they responded promptly-  another 25 years for the footage to get back to us. So Zog's most recent footage would show what was taking place on Earth 50 years ago,  albeit in Zogian "real time"!

For historians, it would be the equivalent of the "third umpire" in cricket - the video camera that is the final arbiter on what really happened... Now then, was there a second gunman, lurking behind that grassy knoll?

Thursday, September 3, 2009

Who says artificial sweeteners don't help you lose weight?

 Is the love-affair over?
So who is saying that artificial sweeteners don’t help you lose weight?

Answer : Professor Soraya Shirazi-Beechey, who is a veterinary science researcher at the University of Liverpool.  She claims that "our bodies cannot distinguish between them and sugar."  So what's wrong about that, you might say?  We all know that artificial sweeteners - saccharine, aspartame etc - are no magic wands. But is the body totally fooled,  indeed traduced by them, even in the lower regions of the small intestine, as she claims?

Well, see the article by Chris Irvine in today’s Telegraph (Health Section) and judge for yourself. To say I read it with a growing sense of incredulity, indeed bafflement, would be a gross understatement. Little if any of it makes sense to me.

Let's  begin with the statement that “artificial sweeteners do nothing to help weight loss”. It does not appear to be a  finding of the Professor’s research. Indeed, from googling her other work, it would appear to be more by way of an article of faith.

Whilst I’m no expert on weight loss strategies – and am fighting a losing battle – that statement offends the most basic scientific principles. If somebody is on a dietary regime that just maintains body weight, and they then replace the sugar in that diet with artificial sweetener – then they are almost certain to lose weight, since their calorie intake is reduced. Now the cynics or defeatists may say differently, claiming, for example, that sweeteners increase one’s appetite for real sugars. But that does not permit the bald statement that artificial sweeteners do nothing to help weight loss. We all know, or should know, that any slimming aid has to be  part of a “calorie-controlled diet”.  We are constantly warned about that on the side of food packaging.

She then says that our bodies cannot distinguish between the sweeteners and sugar. Here’s where it starts to get scientifically a bit complicated, but bear with me, and see if you can follow the lady’s chain of reasoning.

We have at least two different sensor  locations for real sugars - sucrose, glucose etc - in our bodies. One is in the taste buds,  which detect “sweet”. These we know can be fooled, so that an artificial sweetener, with a chemical structure entirely different from real sugars, registers as “sweet”, making that cup of coffee more appealing to those of us with a sweet tooth.

But there's another place too -  down in the intestine -  where we have clever systems in the wall of the gut  concerned with selectively absorbing sugars into the blood stream. The important one where this post is concerned  deals with ordinary cane sugar ie “sucrose”, in our diet. There is an enzyme in the wall of the gut that recognizes and binds sucrose, and then cleaves it into two halves – glucose and fructose. There is then another system that recognizes and binds these sugars and then transports them across the wall of the bowel into the bloodstream. The glucose transporter works in conjunction with sodium uptake, and is called the sodium-dependent glucose transporter.

So where does the Professor’s research change our picture of this well-established digestive physiology?  She claims to have found yet another system in the bowel comparable to the one in our taste buds that recognizes “sweetness”.  In other words it  is activated not just by natural sugars but by artificial sweeteners. She herself has described that as “surprising”. Indeed, it is surprising. What’s a receptor for one’s perception of whether food is nice to eat or not doing way down in the bowel?  Down there one would expect molecules to be recognized purely by size, shape, chemical make-up – nothing so subjective as taste.

Now here’s where things start to get really bizarre. The prof' says that these new sweetener receptors are the reason why sweeteners don’t allow us to lose weight. She claims that the sweetener receptors fool our ordinary sugar-transporters into thinking there's an abundance of real sugar about, and send a signal to our sugar-transporters to work more efficiently. End-result – we absorb more glucose and other sugars from the diet than we normally would. Result: the sweeteners make our bodies more efficient at absorbing sugar calories, with the result that we fail to lose weight, and indeed are at risk of putting on weight

Hold on a minute. There’s a weak point in that argument – and that’s all it is – an argument – a far cry from doing  scientifically-controlled experiments.. It’s the assumption that sugar absorption from the gut is inefficient in normal individuals, and that sweeteners improve that efficiency.

Well, I personally know of no evidence that we are inefficient at absorbing sucrose. OK, it may not be 100% efficient – small amounts may reach the lower bowel where it would be fermented to hydrogen, short chain fatty acids etc. But if sucrose were just 95% absorbed,  with a "mere" 5% reaching the lower bowel, we would quickly know about it to our gross discomfiture, with bloating, wind, intestinal cramps – in other words all the symptoms suffered by those with the distressing and socially-embarrassing  "malabsorption syndromes".

Sorry, Professor , but your story does not make sense. To be honest, there seems to be just a little science, and a whole lot of conjecture. What’s more, it’s conjecture in an area in which consumers are already bombarded with a lot of conflicting information from scientists and health professionals. Someone has to act as watchdog. Who better than a retired biochemist/nutritionist with time on his hands? I would send a brief critique to the Telegraph, but there’s unfortunately no facility for doing so. But there is this ability now to attach comments and critiques to Google links. Tally ho!

PS   The Mail has opened a thread on this topic 

Update Sun 5th September. Who says that personal blogs are a waste of time, unless one is besieged daily by comments?

I've just been googlin', and find my humble observations as a "retired biochemist/nutritionist" have been picked up across the pond by an Atkins Diet/Low Carb forum.  Here's what "OregonRose" has to say:

"A few thoughts:

First, is this "real" research? There doesn't seem to be an actual paper or published findings associated with Shirazi-Beechey's alleged research; it's somehow "on display" at a Food Museum. That doesn't sound too awfully rigorous to me, although I might not be qualified to judge that. Also, in the articles I Googled up on her (Soraya Shirazi-Beechey + artificial sweeteners), I found lots of sound-bitey quotes from her but no mention of actual experiments and actual results. And there's this guy, a retired biochemist/nutritionist, who takes issue with what he labels her bald assertion, noting that there doesn't seem to be any experimental data to back up her claim:


Second: As to the problem of where the "extra" absorbed glucose in a low-carb diet might come from--assuming for the sake of argument that her claim might have merit--what about glucose generated by the liver from protein? Supposing she's right, maybe somehow AS prods the liver to produce more?

And finally, the whole claim sounds weakly supported to me. Sure, I think avoiding AS is a good idea in general, along with any other frankenfoods, since we just don't know enough about them (heck, we know barely anything about our own physiology, and here we as a species are throwing hundreds of thousands of years of accumulated food wisdom away and eating who knows what...). Nevertheless, during my first year of LC, they helped assuage many a dessert craving, and I'm glad they were available."

I'd have left a comment, but not only is the site not open to those who are not registered, but I'm fundamentally opposed to the Atkins diet - not because it doesn't help lose weight - it almost certainly does - but because I consider it to be  misconceived - biochemically, physiologically and medically. The Atkins diet takes a huge liberty with one's cellular biochemistry - the subject of a forthcoming post.

Wednesday, September 2, 2009

Why is Moon dust sticky?

  This goddamned stuff gets everywhere!

I expect you have seen those close-up photographs of spacemen on the surface of the Moon. Have you noticed how they invariably have dust sticking not just to their boots, but higher up- often up to the knees in fact?  That dust is sticking to a vertical surface - in defiance of gravity - albeit weaker on the Moon than on Earth.

Well, there was an opportunity this morning on the New Scientist's website to mention that strange stickiness of Moon dust, and to speculate on what might cause it.

Afterthought: "sticky" is perhaps not the best adjective, since it may suggest "gooey". Maybe the title should have been : "Why does Moon dust stick to everything?"  If this were a scientific paper, which it's emphatically not, I guess one would be deploying terms like "adherent" etc. "Sticky" will do for now.

Tuesday, September 1, 2009

How come the mechanical engineers were able to steal a march on the Royal Society?

 The Royal Society HQ, London

The Institution of Mechanical Engineers, London

A few days ago the Institution of Mechanical Engineers was in the headlines - under photographs of highways lined with wind turbines and strange new "artificial trees".  The latter were poorly explained. In fact, even now, after diligent internet searches, I'm still not certain as to whether they are science fact or science fiction. More about the technological feasibility later.

For the moment, I'd simply say that I placed a comment on the Times, asking why a particular professional society with a mech' eng remit was hogging the headlines, given that solutions to global warming and climate change require an interdisciplinary approach.  I was careful to slip in a mention of the Royal Society in the list, feeling that it should be orchestrating the response from the UK's scientific, indeed engineering community too (since engineering solutions are only as good as the underpinning science).

Here's what I said...

"... one notes that these latest suggestions - which are by no means new - have come from the Institute of Mechanical Engineers. Might it not have been better if proposals for saving the planet had come from a broader-based consortium of professional societies, that would have included the Institutes of Biology, the Royal Institute of Chemistry, The Institute of Chemical Engineers, the Royal Society etc etc? The underlying chemistry/biology in today's press release is hardly impressive, and regrettably less-than-authoritative."
Note the date.  Today, just four days later, the Royal Society has come out with  its own position paper, with proposals that look remarkably similar to those of the Institution of Mechanical Engineers.  Indeed, they ask for the same pump-priming Government support to the tune of of £10m. 
So, did the engineers jump the gun, one wonders, stealing the thunder of the senior service?   Did the latter wince on seeing its apparent inertia being pointed out by your humble blogger?  I guess we'll never know, but you have to admit that it's odd that two prestigious societies say basically the same thing within a few days of each other, with an apparent breach of the expected pecking order...

Newspaper sub-editors: bless them...

 Satellite photograph: Saharan dust, blowing westwards, carrying plant nutrients to the Amazon

There's an invited article in today's Telegraph by Steve Jones. His academic title is Professor of Genetics at University College London, but he's better known as a high profile author and TV presenter.  He is writing on Mother Nature's dust bowl phenomenon, scourge of farmers past and present, but tempered with the recognition that dust, stripped off land in one continent, can  provide nutrients thousands of miles away.This is a topic on which I blogged on the old Dreams and Daemons site.

Did you know that the nutrient-poor laterite soils of the Amazon basin are fed by dust blowing in from across the Atlantic - from the Sahara desert in fact, and from a relatively small part thereof (a  particular dried-up lake bed - the Bodélé depression- that is subject to ferocious sandstorms - or should that be dust storms?).

And what title has the Telegraph sub' used on the Home Page.  Wait for it: "View from the lab:  Beware of the dust".  The lab?  Well now, that's you pigeon-holed Professor Jones. Did they ask for a picture of you in a crisp white lab coat,  peering intently into a test-tube?

 Steve Jones

PS I see from Wiki we were both born the same year, but you already qualify for the State pension. This retired lab wallah still has a short while to wait.