Through The Sandglass

Another use for sand

Having made my own rather chilly trip to the coast yesterday, I was delighted to see the photo above on the front page of this morning's San Francisco Chronicle; the image is titled "Ana Umali, 11, finds a way to stay warm on Ocean Beach. Temperatures in San Francisco have been about 2 degrees below normal, but have been as much as 10 degrees below normal in the Santa Clara Valley."

The headline is "Bay Area's chilly summer not its coldest" and the article begins with "This has been the summer of our discontent. Not only has the economy been lousy, but the summer fog has also hung around day and night, like a houseguest that won't leave." Well, it's foggy again this morning and this houseguest is on his way southward.

The sands of San Francisco

Just to prove that I am where I said I would be, and to confirm that, if there is sand to be found, I'll find it. More on these and other wonders later, but I realise that this is my 200th post, so cause for some celebration - which I did last night very successfully and enjoyably with Brian Romans (the human face of Clastic Detritus) over some excellent locally brewed IPA in a dark bar in the Mission district - the sign outside simply said "Bar," nothing more, nothing less, it did what it said on the tin (or can - my American is coming back to me).

Oh, and around the Golden Gate coast and the Presidio Park, there is lots of deadly serpentinite - yet no public health warning signs. Incredible.

On the road - SciFoo

I'm about to head off to San Francisco for the SciFoo event, organised by Google, Nature, and O'Reilly Media, and held at the Googleplex in Mountain View.  It's a sort of "unconference," described on the website as "Foo Camp is an informal conference format pioneered by O'Reilly Media, a leading book publisher and event organiser in the field of information technology. There is no predefined agenda, instead attendees collaboratively create one during the first evening, having shared ideas in advance through a wiki. Since the first O'Reilly Foo Camp in 2003, these events have become legendary and much imitated."

The list of attendees (or "campers") is truly impressive and, I must confess, somewhat intimidating - but, nevertheless, fascinating. I have no clear idea what to expect. But, since I have become increasingly exercised about the damaging effects of policy and society seeking certainty in an uncertain world, I have suggested a session in which totally "out of the box" ideas for not only communicating, but enjoying uncertainty might emerge - how can we make uncertainty fun?:

Embracing uncertainty

We live in a world that is not black and white but glorious shades of grey, and it is there that science thrives. Yet human nature and society yearn for – and routinely demand – certainty. This contradiction distorts not only the perception of science and scientists, but the integration of sound science with policy and decision-making (see, for example, the current controversy over the construction of sand berms in the Gulf of Mexico). How might we, as scientists, help create an environment in which uncertainty and an uncertain world are not just tolerated, but actively embraced? 

I'll try to put up a post or two as things progress, but, in the meantime, if anyone has ideas (a video game? reality TV?) then I would love to hear them.

Sandfish robotics: the story continues

 

Almost exactly a year ago, I wrote about the remarkable abilities of Scincus scincus, otherwise known as the sandfish, sand skink or sand swimmer. This little Saharan lizard can swim through sand like a fish through water, and the way in which it does it remained a mystery until researchers at Georgia Tech set out to tackle the problem. It turns out that the sandfish undulates its body in a sinusoidal wave motion, tucking in its limbs and modifying the frequency of undulation in order to control speed and manage its movement in sands of greater or lesser compaction.

At the “CRAB lab” at Georgia Tech,  Daniel Goldman and Ryan Maladen's team have continued their research, moving further into mathematical modelling, iterated and integrated with lab experiments; they have also worked in collaboration with Paul Umbanowar at Northwestern University in Illinois who is one of the gurus of the bizarre world of granular materials, and who kindly helped with several illustrations in my book. The results not only shed light on one of nature’s wonders, but generate important advances in robotics. Recently, the team has reported on a newly developed prototype robot, constructed from easily available components, that directly simulates the skills of Scincus scincus, and could lead, for example, to vital developments in post-earthquake search and rescue efforts. The complete paper by the group is available online (the illustrations at the head of this post are taken from there), and the Canadian Discovery Channel has a great video report (although I do rather resent the presenters referring to sand as “dirt”). The work was described briefly in the New Scientist, but since the full version, by James Urquart, is only available by subscription, I’ll take the liberty of reproducing it here:

Lizard-like robot can 'swim' through sand

TO ADD to the robots that can crawl over land, fly through air and swim underwater comes one that can swim through sand. Such robots could help find people trapped in the loose debris resulting from an earthquake.

Navigating through sand is harder than moving through water or air because sand can behave as both a solid and a fluid. We have no equations to describe how such substances flow, let alone to predict how an object can "swim" efficiently through them.

But the sandfish lizard, Scincus scincus, can travel through sand effortlessly, so Daniel Goldman and Ryan Maladen's team at the Georgia Institute of Technology in Atlanta decided to find out how they do it. They found that once the sandfish is submerged, it tucks its limbs into its sides and propels itself forward by wiggling from side to side.

Working with Paul Umbanhowar of Northwestern University in Evanston, Illinois, the team plugged their results into a computer model, which they used to show that a snake-like robot with just seven body segments could travel through a granular medium like sand.

Encouraged, the team built a 35-centimetre-long version of the robot, made from seven aluminium segments linked by six motors, all clothed in spandex to prevent the motors from becoming jammed.

The team then tested their robot by burying it in a container filled with plastic spheres 6 millimetres across. When the robot undulated its body at a frequency similar to the lizard, they found it could move forward at speeds of up to 0.3 body lengths per wave cycle - just below the 0.4 body lengths per cycle that a submerged lizard can achieve.

The robot could eventually match the lizard for speed, says Goldman, if more jointed segments are added to make its movements smoother.

Howie Choset, a roboticist at Carnegie Mellon University in Pittsburgh, Pennsylvania, thinks that the physics and the biology-inspired approaches to robot movement will one day meet and "at the intersection will be a deeper understanding of how biology works and how to make robots better".

Amongst the many things that I find fascinating about this work is the fact that it is a carefully executed project that uses mathematical modelling in intimate combination with laboratory experiment – the “fieldwork” informs the maths which, in turn, informs the next phase of laboratory investigation. In a world where, in my view, we place undue faith in the validity of mathematical models alone, particularly when evaluating complex natural processes, this kind of “continuous feedback” approach is to be admired and emulated.

[ The Georgia Tech press release page has links to further sources]

Sand+bacteria+urine= bricks: continuing performances of bacillus pasteurii

 

“It’s synthetic sandstone. All that’s happening is crystals are growing around sand grains.”

The way in which Professor Ginger Dosier describes her innovative process that has recently won the Metropolis “Next Generation” design competition is accurate, but perhaps slightly over-simplified.

I never ceased to be amazed by friendly bacteria. We may have an instinctively negative view of our super-abundant microbial colleagues, but many of them are really helpful, and we’d be in a bad way without them. Take, for example, the bacteria that munch on natural crude oil in ocean water or in sand; take the wondrous critter, bacillus pasteurii, that can turn sand into sandstone and heal cracks in concrete. And now here, although appearing under a different name, is bacillus pasteurii again.

Ginger Dosier is an architect at the American University of Sharjah, in the United Arab Emirates, but an architect with a difference: she is interested in designing her own building materials and thereby participating directly in influencing the performance of a building. She has chosen the most basic of building materials, the brick; as she comments,  “Bricks are so humble, they are the lowest common denominator in architecture. Bricks were designed around our hands; one is used for holding the brick and the other for the trowel. I wanted something that would slip right into the system and the entire construction system would not have to be redefined.” And what she has done is potentially of huge importance, because bricks may be humble, but their manufacture consumes large amounts of energy and creates more atmospheric pollution than the entire aviation industry. A standard brick must be fired in a kiln at temperatures greater than 1000 degrees centigrade; making a couple of bricks generates more than a kilogram of carbon dioxide – and it’s estimated that perhaps 1.2 trillion bricks are manufactured around the world every year. Dosier’s solution is don’t bake the brick, grow it.

And this is where our old friend, bacillus pasteurii plays the leading role. Although the reports of the brick-making process describe the bacteria used as sporosarcina pasteurii, it would seem that this is just an alternative (stage?) name for bacillus pasteurii  - why the microbiologists can’t make up their minds is beyond me, but there we are.  Bacillus pasteurii, if treated right, produces calcite that can glue sand grains together (or mend concrete, for that matter); the process is referred to as microbial-induced calcite precipitation, or MICP. Treating the bacteria right requires feeding them which is where the urine comes in – urea [(NH₂)₂CO] can be made synthetically or from urine, and provides nutrition for the bacteria. Water is also necessary, as is calcium chloride.

The process for making a brick is relatively straightforward: put dry sand into a mould, add the cultured bacteria, water, urea, and calcium chloride, and wait for about a week – other than the 37 degrees centigrade at which the bacteria must be prepared, no heating is required. But it took Dosier two years to find the right proportions of materials, the right microbes, and the right chemistry, and her eventual success was another example of laboratory serendipity:

Then one afternoon, she threw together a bunch of scraps from some old, ill-fated tests, for kicks. Practically forgetting about it, she revisited experiment No. 112 a week later, only to discover that the medium had transformed into a “baby brick,” as she tells it, a four-by-two-by-one-centimeter proof of concept. “I was shocked to find that it had worked,” she says, “and glad that I took detailed lab notes.” The magic formula was in allowing the right concentration of bacteria to fester just long enough.

Currently, her bricks are small - about 3cm long, 1.5cm wide and a centimetre deep – but she’s working on scaling up. And scaling up to any kind of commercial mass production process is yet another, hardly trivial, step. But the potential is huge. Dosier contemplates the ability to program a brick’s exact composition and then “ fabricate it layer by layer on a 3-D printer. The technology poses countless design possibilities. Ball-shaped bricks: Why not?” (Metropolis).

But, as usual, it’s still not quite that simple:

Microbial-induced calcite precipitation spews tremendous amounts of ammonia, as scientists affiliated with Delft University of Technology, in the Netherlands, discovered recently when they tried the chemical process on contaminated sand and soil. “High ammonia concentrations result in environmental eutrophication and eventually, via microbial conversion to nitrate, the poisoning of groundwater,” the Delft researcher Henk Jonkers writes in an e-mail. If the bacteria continues to convert ammonia to nitrous oxide, he adds, it can produce a greenhouse gas 320 times more powerful than CO2.

Dosier is thinking about emissions capture in the manufacturing process, another complex and multi-disciplinary challenge, but she’s up for it: having come so far as an architect learning and working in different worlds, she deserves to succeed.

[See also PopSci, Inhabitat, and the UAE site, The National, for more information]

Oil, sand, and microbes

I’ve posted some references on the possibilities and the issues of oil-eating bacteria in the Gulf Coast clean-up attempts, but these were essentially focused on oil in the ocean (see this post and the links within it). But what goes on in the sand, in what is normally a thriving microcosm of critters in the spaces between the grains on the beach? A few days ago, Sean (who writes as “F”) pointed out a link to a press release from Florida Sate University on a new study of how fast microbes can break down oil in the beach sands of the Gulf of Mexico. The topic is far too interesting and important to be left stranded within a comment, so I thought that I would highlight it here.

The study began, on something of an emergency basis, in June, and is being headed up by oceanography professors Markus Huettel and Joel E. Kostka. As the introduction to the article describes:

A new Florida State University study is investigating how quickly the Deepwater Horizon oil carried into Gulf of Mexico beach sands is being degraded by the sands' natural microbial communities, and whether native oil-eating bacteria that wash ashore with the crude are helping or hindering that process.

What oceanography professors Markus Huettel and Joel E. Kostka learn will enable them to predict when most of the oil in the beaches will be gone. Their findings may also reveal ways to accelerate the oil degradation rate — and speed matters, because toxic crude components that remain buried on Gulf Coast beaches may seep into the groundwater below.

In many respects, the already degraded oil in the form of mats, pancakes, and tar-balls is relatively easy to clean up when it lands on the beach. Much more difficult and longer-lasting is liquid oil that seeps down into to the sand – and its effects are not very well known. In fact, the entire world between the grains of a beach is not very well known. One of the (many) great surprises that I encountered while researching my book was the incredible biodiversity of microscopic creatures that inhabit what Rachel Carson described as the “underground city” of the beach. Meiofauna (“lesser animals”) is the general term for this microscopic subsurface zoo, and I wrote a little about these extraordinary creatures in a post a year ago. In that piece I described how we should be grateful to these wondrous creatures because they keep our beaches clean, consuming undesirable bacteria. But, in the great scheme of things and the startling panoply of nature, we shouldn’t indulge in sweeping denigrations of bacteria – as we know from the oil-eating ones that live naturally in the ocean, there are many things that we should be grateful to them for.

But what happens when oily water, together with marine bacteria munching away, arrives on a sandy beach? How is the entire zoo affected? What happens as the oil percolates deeper and deeper into the sand, through the oxygen-rich layers where aerobic life thrives down into the anaerobic realms where there is no oxygen? The Florida State study will help answer these questions and, hopefully, provide some ideas on remediation methods. But it’s going to be a complex challenge:

Kostka said oil accumulations deposited on the beach surface are easily removed by, for example, scraping off the top layer of sand. However, the oil components that penetrate into the sand can only be removed by microbial degradation.

"If oxygen is present — as it is in the water and in the upper layers of the beach sand — the microbes decompose the oil aerobically (by using oxygen)," Kostka said. "This degradation process is much faster than the degradation under anaerobic conditions (when no oxygen is available), such as those found in deeper sediment layers of the beach. That's why at the site of the Exxon Valdez oil spill in Alaska, oil can still be found deeply buried in the gravel beach sediments, because anaerobic microbial degradation is slow and, in Alaska, slower still because of the cold climate."

"Unfortunately," said Huettel, "crude oil contains such harmful substances that even small amounts can kill fish larvae — which means that oil stored in deep layers of beach sediment presents a potential source of toxins to near-shore waters and groundwater."

Heavily oiled sand samples from a Louisiana barrier island (from the Florida State article)

Meanwhile, out in the ocean, there are reports of much increased bacterial activity. The Miami Herald recently carried an article in which Samantha Joye, a marine sciences professor at the University of Georgia at Athens, is quoted as saying "That's really, really surprising. Clearly the microbial community is responding rapidly and rigorously to the input of oil and gas." Let’s hear it for the microbes!

………………………………………………………………………………………………………….

And, while I’m at it, to return briefly to the vexing topic of the sand berms, the “Great Wall of Louisiana”. Discovery News recently carried a piece, borrowed from Len Bahr’s LACoastPost blog, with some interesting photographs of bulldozing the Chandeleur Islands. Well worth taking a look – I was reminded of the story of King Cnut…….

[header images from the US Coast Guard site]

 

Accretionary Wedge: the Geoblogosphere

Dave Bressan (History of Geology and Cryology and Co.) has posted a call for a new Accretionary Wedge episode with the grand theme of the geoblogosphere, geology, and society. David and I have corresponded on various topics, including this one, and so here I am in a kind of supporting role in this carnival. A few months ago, I put up a commentary on the geoblogosphere that I had written for the Geological Society's online discussions; Chris Rowan, of Highly Allochthonous, contributed to this piece, and it was our hope that it might stir things up a little in the relatively sedate worlds of not only the Society, but also the UK geoblogosphere in general. Alas, this hope was not to be fulfilled - the response was not one that required earplugs.  

Having been scribbling away on Through the Sandglass for some twenty months now, and following as many science blogs as I can, I find the dynamics and issues around the whole process and product fascinating. I write the blog because I enjoy it and because I am put in touch with people that I never otherwise would have known, even vicariously. And I learn a lot in the process. This satisfaction is derived from a very modest scale of things - I note that a typical post on Pharyngula receives more comments than I have over the entire life of my blog; but then I also note that many of the comments on Pharyngula are not ones that I would want to publish anyway - I enjoy his posts, but have no desire to emulate PZ.

One of the many things that strike me about the geoblogosphere is its civility and objectivity. The more lurid and globally popular segments of the blogosphere as a whole are filled with vituperative, ad hominem - and often inarticulate and, of course, anonymous - rants. Not so with us geobloggers, which is a good thing - is this something that can be exploited constructively? There is, after all, much discussion (much of it vacuous) about the role of the blogosphere, and I've been doing a little probing around some of the (non-vacuous) examples of this. One of the "debates" is whether blogging is journalism - in my view, this question, as such, doesn't mean much since both blogging and journalism cover such a multitude of sins. But the question is interesting in terms of the relationship between blogging and journalism, within which lies a possible future vector for the responsible blogosphere. Read, for example, the piece (and the comments) on the BBC College of Journalism blog, titled "Blogs are not real journalism." And then consider this from one of the comments:

To say "blogging is not journalism" is a rather meaningless statement as it depends on what definition of "journalism" one picks, surely?

A rather important point is that in blogging about science the bloggers are often people who know far more about science than the journalists who cover it. This is one of the reasons why blog coverage of scientific stories is often far more accurate and informed than what appears in the mainstream media.

Indeed it seems to me, from reading the works of the mainstream media science correspondents, that the ones whose copy is generally more accurate are the ones who follow the science blogs. I wonder what that is telling us?

Then I came across a workshop put on earlier this year by the Harvard Kennedy School's program on Science, Technology, and Society (STS). Titled Unruly Democracy: Science Blogs and the Public Sphere, it's quite an intriguing series of talks and discussions - but, unfortunately, the sessions are documented only through a series of rather poor-quality videos - I've watched some, and they're interesting, but I'm afraid that I haven't had the stamina to complete the course. Being a bit of a luddite, I'd really like to be able to digest a written summary - the only one I can find is an entertaining discussion by Jessica Palmer (who was there) - well worth a read.

So there's a lot to talk about on this subject - David and I really look forward to your observations and, most importantly, ideas, for the geoblogosphere - where to go, how to add value, how to leverage the creativity and the passion of geobloggers. Out of the box, folks!

Building sandcastles is a crime - in parts of Italy, at least

If you are planning a beach holiday in Italy, don't go to Eraclea, near Venice, if you or the kids enjoy building sandcastles - it's a criminal activity there. Italian mayors have been given sweeping powers to "protect public security" and they have been exercising them in bizarre ways. Public kissing, squeaky sandals, and ball games on the beach have all been banned by various zealous officals, but the good bureaucrats of Eraclea, farsightedly anticipating risks to the public, have banned sandcastles as obstructive to walking on the beach and thus dangerous. Collecting shells and sand is also banned (arenophiles, please note) and all these activities are subject to heavy fines.

Italy, the country where seismologists can be indicted for manslaughter, and new kebab shops banned as a threat to its culinary heritage, is an idiosyncratic palce, to put it mildly. And I won't even begin to comment on its politics in general.....

Gulf Coast: now it's rocks - "out-of-touch academics" object again

 

"Rocks in the water are much less damaging than oil in the water," Gov. Jindal said. 

The latest mega-scheme for the Great Wall of Louisiana is to use rock barriers across tidal inlets in the barrier island chain that runs across the mouth of Barataria Bay, the huge and environmentally complex estuary in the western Mississippi Delta. This is actually the resurrection of a previous plan that was, for good reasons, rejected. As reported in a New York Times article a couple of days ago, “There was very strong scientific backing for not doing this,” said Denise Reed, a wetlands specialist and director of the Pontchartrain Institute for Environmental Sciences in New Orleans. “This could really devastate our barrier shoreline, our first line of defense.” And from the WWLTV site yesterday, where the Jindal quote above comes from:

However, not everyone agrees with that assessment. UNO's Dr. Denise Reed opposes the rock barrier plan because of the potential damage it could inflict on nearby barrier islands. 

"If the rocks have closed down the places that that water could come out, then the water is going to find a way," said Dr. Reed, who is with UNO's Pontchartrain Institute for Environmental Sciences and has studied the state's ever-changing coastline for more than 25 years. "The concern that many of us have is, then the weakest link is the barrier islands themselves. The rocks may not wash out, but the barrier islands could." 

The Army Corps of Engineers said much the same thing in its rejection letter to Jefferson Parish. 

Col. Al Lee wrote that the rock barriers could "...redirect water movement to other passes and result in the establishment of new avenues for tidal flow, especially during tropical storm events." 

But the rocks are ready, sitting in barges waiting to be deployed (lower right in the header image). Here's a spectacular satellite image of the delta, showing the location of the bay, its barrier islands, and the spectacular complexity of sediment movement. Come to your own conclusion of the wisdom of blocking off the inlets between the barrier islands, and whether or not you side with the "out-of-touch academics" and "pencil-pushing bureaucrats" constantly denigrated by state and local officials.

 

[satellite image: http://www.esa.int/esaEO/SEM6A1CE8YE_index_1.html; see also an interesting piece on Jindal in today's Time Magazine online]

Limulus polyphemus: sand artist and one of nature's wonders

 

So OK, Jim Denevan is in a different league, but back in May, when the tides were high and the first full moon of the month was rising over Queens, New York, Larry Deemer sent me this picture of a visiting artist on his beach.

This horseshoe crab, Limulus ployphemus (which is not, as we shall see, a crab at all), is probably a male, and appears to have been either drunkenly or creatively celebrating a night of mating - for when the May moon is full and the tides are high, that is the time for such things in the world of the horseshoe crab. Either way, he was out of sorts, as Larry described him before helping his return to the sea.

Horseshoe crabs are Arthropods, animals having articulated bodies and limbs, and as such are more closely related to spiders than they are to crabs. And they are really ancient - their fossil ancestors would seem to be trilobites and they themselves have existed, essentially unchanged, for hundreds of millions of years; the mass extinction that did for the dinosaurs had little or no effect on them. Around the world, there are four species, Limulus ployphemus occupying the eastern seaboard of North and Central America, and the others the western Pacific rim. All these species are built and operate in pretty much the same way, one particular characteristic being that the males are smaller than the females; the females are built big in part simply to be able to carry their huge burden of eggs - up to 80,000 a year. Another key difference between the males and the females reflects the process of fertilising all those eggs - the female's
front two appendages, out of a total of six pairs, are pincers; but the males have quite different claws, sometimes referred to as "boxing gloves," and specially designed for holding on to a female - sometimes for very long periods of time (months?). For a useful guide to horseshoe crab-sexing, see The Horseshoe Crab website, where there is a vast amount of fascinating information. So, in Queens in May, like many beaches up and down the east coast, the sands are littered with stuck-together pairs of horseshoe crabs - and lone males. It seems that, as the female digs a shallow hole in the sand to lay her eggs, they are fertilised not just by the hanger-on, but also by what are referred to as "satellite males" - the voyeurs of the horseshoe crab world.

The eggs are pearl-like - and provide a fabulous buffet for a variety of birds:

 

Here, however, is the problem. Horseshoe crabs have long been used as a source of bait for various types of fishing, and their numbers have plummeted. It's not that long ago that a full moon in May would have resulted in beaches literally covered in horseshoe crabs, often several deep, but no longer. And the fall in their numbers is disastrous not just for them but for the migratory birds that rely on this food supply. Intensive conservation efforts are now in place, but success has yet to be demonstrated.

But horseshoe crabs are extraordinary and wonderful not just because of their dramatic spawning rituals. Consider the following:

• unlike the giant one-eyed son of Poseidon, after whom they were given their name, they actually have two compound eyes. But they also have five additional eyes on the top of their shell, and two more on the underside. This visual system is unique in nature and, understandably, the subject of much research. The 1967 Nobel Prize for medicine was awarded for "discoveries concerning the primary physiological and chemical visual processes in the eye" - research based significantly on the visual system of the horseshoe crab.  
• while vertebrates use haemoglobin, an iron-based protein, for oxygen transport in their blood, horseshoe crabs use a copper-based protein - when their blood is exposed to the air, it's blue. (Truly blue-blooded, unlike the British aristocracy).
• but the most extraordinary thing is that any of us that has had an injection, a vaccination, or an intravenous drip should be deeply grateful to Limulus ployphemus. As described on the site linked above:

An extract of the horseshoe crab's blood is used by the pharmaceutical and medical device industries to ensure that their products, e.g., intravenous drugs, vaccines, and medical devices, are free of bacterial contamination. No other test works as easily or reliably for this purpose.

In the 1960's, Dr. Frederik Bang, a Johns Hopkins researcher working at the Marine Biological Laboratory in Woods Hole, Massachusetts, found that when common marine bacteria were injected into the bloodstream of the North American horseshoe crab, Limulus polyphemus, massive clotting occurred. Later, with the collaboration of Dr. Jack Levin, the MBL team showed that the clotting was due to endotoxin, a component of the marine bacteria originally used by Dr. Bang. In addition, these investigators were able to localize the clotting phenomenon to the blood cells, amebocytes, of the horseshoe crab, and, more importantly, to demonstrate the clotting reaction in a test tube. The cell-free reagent that resulted was named Limulus amebocyte lysate, or LAL. The name LAL is extremely descriptive: Limulus is the generic name of the horseshoe crab, amebocyte is the blood cell that contains the active components of the reagent, and lysate describes the original process used by Levin and Bang to obtain these components. In Levin and Bang's process, amebocytes, after being separated from the blue-colored plasma (hemolymph), were suspended in distilled water where they lysed (ruptured) due to the high concentration of salt contained in the amobocytes versus the absence of salt in the distilled water. Surprisingly, this same process with some minor modifications is still used today to produce LAL.

• and, furthermore:

Besides LAL, a number of reagents and medically useful compounds have been discovered in the blood of the horseshoe crab. These include:

· A new test for fungal infections (G-Test) which is already in use in Japan and is expected to be licensed in the US next year

· An endotoxin-neutralizing protein which has potential as an antibiotic as well as an alternative endotoxin assay. This protein, ENP, can be made synthetically, which would eliminate the use of live horseshoe crabs for the LAL reagent.

· A number of other proteins that show anti-viral and anti-cancer activity.

Sometimes - often - I set out on the track of a simple-sounding post and end up discovering extraordinary things - this is a classic example. Oh, and Larry tells me that the penis of a male horseshoe crab is bifurcated - I haven't been able to confirm this, but will readily admit that I haven't pursued this topic in detail.

 

[photos from http://www.ahherald.com/oaktrail/2006/oot060608_more_horseshoe.htm, http://citybirder.blogspot.com/2006_06_01_archive.html, and http://www.bbc.co.uk/radio4/worldonthemove/reports/red-knots-of-delaware-bay/; also see a NY Times article by Natalie Angier, the Project Limulus website, and numerous sources on Wikipedia.]