Tag Archives: neat science

Saving Kemp’s Ridley Sea Turtles From Extinction

The Kemp’s Ridley (Lepidochelys kempii) sea turtle (also know as the Atlantic Ridley) is a small olive green to black looking sea turtles that reaches a maximum size of 58–70 cm (23–28 in) carapace length and weighing only 36–45 kg (79–99 lb).

One of the organizations I do occasional volunteer work for and with which I have a lot of personal familiarity is Gulf Specimen Marine Laboratory. This lab is one of the premier suppliers of ocean specimens to scientists around the world. They also do sea turtle rescue. And the sea turtle they most often rescue is juvenile Kemp’s Ridleys. GSML is located in a region famed for blue crabs and juvenile Ridleys eat a lot of crabs. So GSML is Florida’s juvenile Ridley headquarters.

Sea turtle rescue

In 2015 GSML joined with The Responsible Pier Initiative. This program is designed to educate fishermen and get juvenile Ridleys that have been accidentally caught on an angler’s hook into proper hook removal, care and then return to the wild. Without such care, getting hooked by a fisherman can be a death sentence. With the Responsible Pier Initiative, GSML had a 600% increase in the numbers of Kemp’s Ridleys they saved going from an average of 3 to 19 in the first year! GSML is a small outfit by turtle rescue standards but they get more Ridleys than any other turtle organization in Florida.

I met my first Kemp’s Ridley at Gulf Specimen Marine Lab in 2014. The little guy was a charming fellow named Spot. Spot was lucky. He got sick with pneumonia and was floating about the Gulf, near death, when a fisherman who happened to be passing by in his large boat spotted him. The sharp eyed fisherman netted Spot and took him on board. He called for help and diverted from his planned excursion in order to meet Jack Rudloe at a dock. He transferred Spot to Jack’s care and returned to his fishing. Jack took Spot to Norm Griggs, the vet who treats all the GSML sea turtles (without charge I might add). Spot required antibiotics, time and feeding to recover and he was eventually released ten months later.

2014 was a very bad year for juvenile Kemp’s Ridleys. 1200 of them washed ashore all up and down their range along the Atlantic coast swamping rescue facilities. The turtles were presumed to be suffering from “cold stun” which is what happens when the little fellow end up in colder water than they can function in. It commonly happens in small shallow bays. Low air temperatures in such shallow bays drop the water temperature down to the point that the turtles are stunned. When turtles are cold stunned they are susceptible to infections by a variety of organisms.

In 2014, there were so many sick Ridleys that hundreds had to be transferred to southern rescue aquariums in Florida and Texas. Things at these southern sea turtle rescuers are normally pretty quiet in winter. They are usually busiest in spring and early summer when the turtles migrate back to their nesting grounds. 2014 was not such a year. What made it even worse was the sheer number of turtles that were also very sick and required antibiotic treatment and an extended stay in the rescue facilities for rehabilitation. Cold stunned turtles can develop these secondary infections but normally if you catch them quickly and put them in warm water they can often be released into the wild as soon as it is warm enough.

Fortunately, the 2014/2015 cold stunning event has not happened this year. Unfortunately, we have to assume for every Ridley rescued, rehabilitated and returned to the sea, many many more were not lucky enough to be found by people and those Ridleys simply died. It could be that whatever the 2014 event was, it decimated the Ridley juvenile population. So what was the 2014 event? I am not a turtle biologist but I do have a lot of training in epidemiology. A review of the scientific literature yielded no specific clues. Most authorities seem to think that the cold stunning was just bad luck and the sickness came afterward. Spot, however, was found in Florida waters, not cold stunned but nonetheless very ill. His symptoms matched those of the cold stunned turtles from further north. It is impossible to know for certain, but I suspect the cold stunned turtles of the 2014 event were already ill with the same thing Spot had and the reason they ended up cold stunned was they were too sick to complete their southern migration. This is alarming.

If you measure Ridley population numbers by the numbers of nesting females, it is shocking to see how close these charming creatures came to extinction. Ridleys almost exclusively nest in one place, a 16-mile beach in the Mexican state of Tamaulipas. The number that nested in 1947 was 89,000. We can take this as a base number for what their numbers should be. In 1978 there were less than 200! A lot of care and effort went into helping them. Their nesting site was protected. Some of the hatchlings  were released from the nearby Padre Island in Texas. Baby sea turtles imprint on their birth beach when they dash over the sand to the water and the purpose of releasing them from San Padre was to try to establish a second nesting area. In 1996 there were six nests and that number has slowly increased so that San Padre reached a peak of 209 nests.

kemps-nest

Nesting Sea Turtle Numbers from the Turtle Island Restoration Network

If we look at this graph of the Mexican nesting numbers, we can see that until 2010 the turtles were doing very well. If you think of the nesting numbers in mathematical terms, the population had begun to grow very rapidly entering an exponential growth phase starting about 2000. That was very good news for endangered Ridleys. However, you can see the exponential growth stopped and the numbers dropped abruptly in 2010. A lot of adult turtles did not nest after the Deepwater Horizon spill. It looks like about one third of the nesting females did not make it to the beach. We don’t know if they died or if they simply skipped nesting for one year. It looks like they died because if they had just skipped one year then the curve should have returned to its previous upward surge and it hasn’t. And in 2013 there was some other kind of hit. If we imagine what the curve should have been, it was a bad hit affecting about one half of the adult nesting sea turtles. What about 2014? The provisional number of nests is down again to a mere 118 in San Pedro, down from their highest point of 209. Similarly the 2014 numbers for Mexican nesting has dropped from 13,035 to 10,987, a terrifying 16% plunge in a population that was still reeling from the 2010 oil spill. I have not been able to find the numbers for 2015 but I am hoping the news will not be another drop.

So why have nesting numbers dropped so much? Again I don’t know for certain but my educated guess is this. When any population begins to enter the exponential growth curve, that population is in danger from epidemics. The population density reaches a high enough point that a disease can rapidly spread because individuals  have a very high probability of encountering one of their own while sick and passing he sickness along. It is an unfortunate side effect of success. So getting back to Spot and his pneumonia I can speculate that 2014 was one of those disease outbreak years. (Which is not to say that this sickness was not a delayed “hit” from some long term effect of the oil spill. It may well have been.) If you add in the hit that the population took in 2010 from the oil spill, it is easy to see how dangerous a string of multiple hits can be on a recovering population. In fact, Dick did a paper on the mathematics of multiple hits on a population and how this can cause extinction back in 1993. The take home message is that all our optimism about Kemp’s Ridleys coming back from the brink of extinction must be tempered with caution. They aren’t there yet!

So what can any one of us do about the situation? As it happens GSML is trying to expand the responsible pier initiative to increase the numbers of Juveniles they can save. But their facilities were bursting with healthy hooked Kemp’s Ridleys last year and they need more rehab space. So you can make a donation that will directly help Kemp’s Ridley sea turtles. And if giving to GSML doesn’t suit you, please consider giving to another sea turtle rescue organization. It is we humans who got the Kemp’s Ridleys into their current mess. We can get them out. We just have to decide to do it. You can see the GSML fund raising drive linked below. And I can personally assure you this bunch works largely on volunteer labor and there are no big salaried executives and administrators. Your donations will go directly to help the Kemp’s Ridley (and other sea turtles) back from the brink of extinction.

You can donate here. And Tilt does not deduct a single penny from what GSML gets and if you use your debit card, you aren’t charged anything either. And give or not, please share the message and pass the information on.

Shaped droplets, diatoms and the origin of life

A remarkable paper appeared online 09 December 2015:

The authors, materials scientists from Bulgaria and the UK, mused out loud that their discovery that cooled oil droplets become polygonal had something to do with the morphogenesis of living creatures, but didn’t know which ones. I immediately started writing “On polygonal drops and centric diatoms” followed shortly by “The tensegrity origin of life via shaped droplets as protocells”, and some of the authors of “Self-shaping of oil droplets” are joining us as co-authors.

I had long been puzzling over the uncanny, nearly perfect symmetry of some centric diatoms, which I demonstrated by rotating a digital image of a diatom with n sectors by 360/n degrees and subtracting the images, in:

  • Sterrenburg, F.A.S., R. Gordon, M.A. Tiffany & S.S. Nagy (2007). Diatoms: living in a constructal environment. In: Algae and Cyanobacteria in Extreme Environments. Series: Cellular Origin, Life in Extreme Habitats and Astrobiology, Vol. 11. Ed.: J. Seckbach. Dordrecht, The Netherlands, Springer: 141-172.

Here’s a less perfect example than those used in that paper, the diatom Triceratium favus with n = 3, so the rotation is 360/3 = 120o (with kind permission of Stephen S. Nagy of Montana Diatoms):

 

The subtraction image on the right is black where the match is best. The two published examples, with n = 5 and 11, came out almost totally black. You can try this yourself with any front-on image of a diatom you can find on the Internet, if you have software that allows rotation by any angle. For example, try Word: Format Picture: Size: Rotate and scale, after trimming the picture so that the center of the diatom is in the center of the image. I’d like to see what you get. Please send the original, rotated and difference images to me at: DickGordonCan@gmail.com, along with the exact source of the diatom image. Anyone mathematically inclined (and these diatoms instantiate a rotation group) may wish to write a computer program to quantify the degree of symmetry by coding some of the math in:

We in polar climes are all aware of the beautiful, generally hexagonal symmetry of snowflakes, which has it explanation in the crystalline stacking of water molecules in ice. Some can approach triangular, although they are hexagons with edges of different lengths:

Libbrecht2016 triangular.jpg

This is from:

Libbrecht, K.G. (2016). Guide to Snowflakes: Triangular Crystals.

with kind permission of Kenneth G. Libbrecht. More pointy triangular snowflakes may be seen at:

Bentley, W.A. & W.J. Humphreys (1931). Snow Crystals,  McGraw-Hill. (reprinted by Dover Press in 2003).

But diatom shells are not crystalline at all. They are made of amorphous silica, which at higher temperatures would be molten glass. They are frozen in the glassy state. Are diatoms real life cases of the liquid metal robot T-1000 in the movie Terminator 2? That puzzle is why diatom symmetry is uncanny.

So we start the New Year with a newly discovered phenomenon: oil drops that “should” be mere spherical blobs looking like diatoms. I’ll just show one oil triangle here (with permission of Nature Publishing Group), though the polygons go up to 11 sides:

 

Denkov&2015 Fig2b triangle.jpg

How can a liquid have sharp points like that?

Connections rattled in my brain. Denkov et al. suggest that the oil molecules line up at the perimeter, forming plastic-like bundles as cooling proceeds. Those bundles could be stiff, and prevent the drop from curving due to its surface tension. But then stiff rods confined by tension means that shaped droplets are tensegrity structures. But this is precisely what Steve Levin and I were complaining about the presentations at the origin of life conference we attended together last November: protocells, the blobs that supposedly led to life, had no postulated structure. Two problems solved at once! Diatoms and protocells are and might have been tensegrity shaped droplets. Martin Hanczyc’s oil droplet protocells might be polygonal under some conditions, and Vadim Annekov’s molecular dynamics simulations of diatom shell morphogenesis interacting with cytokeleton (in progress) may be enhanced. Not quite as good as the kids’ book “Seven in One Blow“, but a very satisfying pair of results.

And by the way, this is why theoretical biologists should be regarded as highly as theoretical physicists, although in general we don’t get no respect.

Book Excerpts – Introduction to the Cytoskeleton

FluorescentCells

Eukaryotic cytoskeleton shown using fluoresecence microscopy Actin filaments are shown in red, microtubules are green and the blue is the nucleus. Picture from

If one consults any of the standard developmental biology textbooks, the cytoskeleton will be briefly presented as the support structure of the cell and about as interesting to most biologists as the floor struts in a ballet school would be to an artistic director seeking the next prima ballerina. However, to think of cytoskeleton only as the structure on which cells do their remarkable things, leaves out a good part of the story of how cells work.

We prefer to think of the cytoskeleton as a troupe of acrobats. They run about in the cell, come together, stack to form some remarkable structure and then as rapidly as it appears, the structure falls apart and/or moves and the acrobats appear elsewhere on the stage. These acrobats are the individual proteins that make up the cytoskeleton, and the many proteins that bind to cytoskeleton, transiently hold it together, or move along it. The surface area available on the cytoskeleton filaments for molecules to electrostatically and chemically bind is huge, far exceeding that of all cell membranes in an organism. Ignoring the cytoskeleton while doing molecular biology would be like trying to choreograph a classical ballet on the same stage that has a troupe from Cirque de Soleil rehearsing.

This unfortunate attitude towards the cytoskeleton is beginning to change. For example, several of the pharmaceutical scientific supply companies have recently begun manufacturing kits designed specifically to detect the phenomenon of “cytoskeletal rearrangements” because all kinds of interesting other stuff seems to happen precisely when these rearrangements occur and therefore the rearrangements can be used to time such events. We find it ironic that only a few people seem to actually think this is more than a convenient coincidence.

The cytoskeleton is, as the name implies, the skeleton of the cell giving it shape and form. The concept goes back to Nikolai K. Koltsov in 1903. Koltsov formulated the idea that the deviation of the shape of a cell from the simple ball, that one would expect if it were a liquid drop, is caused by a stiff but elastic cytoskeleton within the cell. Cytoskeleton is nowadays more precisely defined as the various structures that are filamentous polymers of a single class of protein. These filamentous polymers have long-range order within the cell. They should have been called metapolymers, because the proteins they are made of are themselves polymers of amino acids. These cytoskeletal polymers are commonly classified as supramolecular structures. They are polymers of polymers, roughly topologically linear in their structure.

There are three types of cytoskeletal filaments, arranged in order of decreasing diameter as seen by transmission electron microscopy: microtubules (MTs, 25 nm), intermediate filaments (IFs, 11 nm), and microfilaments (MFs, 7 nm) (nm = nanometer = 10‑9 meter = 10‑3 µm). For things this small, we find it convenient to think in terms of the size of the hydrogen atom, whose diameter is 0.1 nm = 1 Å (Angstrom), so a microtubule, for instance, is 250 hydrogen atoms wide. For something so thin, microtubules can be incredibly long, with reported lengths up to 68 µm (micrometers). In Drosophila (fruit fly) species, the length of the sperm can be 5.8 cm (58000 µm), implying equally long microtubules. Such microtubules are therefore over 2 million times longer than their diameter. If we imagine a microtubule as a piece of cooked spaghetti with a width of 3 mm then the length of the spaghetti would be as long as 7 kilometers! The three cytoskeletal filaments are found throughout the cell. They are connected to each other at many points, as well as to the inner surface of the cell membrane , to the outer nuclear membrane and to the inner surface of the nucleus via specialized attachment proteins.

There is a growing awareness of other proteins that may well also be cytoskeletal in nature and deserving of addition to this triumvirate. The cytoskeleton, as a concept, can also go beyond just filaments to include structural sheets, patches and meshes. For example, septins, which are found in animals, are an example of these other cytoskeletal-like proteins. Septins use a protein called anillin to attach to microfilament rings and thereby form rings themselves. These rings line the inner surface of the cell membrane, increasing the membrane’s rigidity. Another example is CTP synthase, which forms filaments in bacteria, yeast and animals. We will nevertheless concentrate on the three best known, best characterized and universally accepted cytoskeletal components. However, the reader should keep in mind that there are likely to be more types of cytoskeletal-like structures that need to be considered in embryogenesis. We will also focus on the mechanical properties of cytoskeleton. There are poorly understood electrical and related potential memory/epigenetic properties of cytoskeleton. These properties may also become important in explaining aspects of embryogenesis.

The cytoskeleton is an extremely dynamic structure that can depolymerize, move and repolymerize within the cytoplasm in a matter of minutes. The three components are often interlinked in a meshwork that is required for cell movements, maintaining or altering cell shape, and for organizing and powering mitosis and meiosis. The cytoskeleton is required for transporting and sequestering proteins to specific regions of the cell. Cytoskeletal associated proteins act as levers and motors pulling cargo such as the vesicles involved in nerve transmission, chloroplasts and whole nuclei.

The cytoskeleton also serves as the host for a variety of enzymes. The cytoskeleton is directly involved in protein functioning of these enzymes by binding to (and thereby changing the functioning of) associated enzymes. The cytoskeleton can therefore direct a response to external physical or chemical signals in the form of movement of the cell towards or away from the signal by polymerizing or depolymerizing during cytoskeletal rearrangements. Due to the cytoskeleton, external signals can even travel down to and into the nucleus and trigger changes in gene expression.

The cytoskeleton found in the nucleus is also made of actin, microtubules and microfilaments but it requires special consideration. Bundles of microtubules ring the inner membrane of some nuclei. The nucleus contains additional unique protein attachments that connect it to the cytoskeleton. At the inner surface of the double nuclear membrane is a sheet of intermediate filaments called lamins, whose functions may include maintenance or change of nuclear shape, protection of the nucleus from mechanical shocks, and intranuclear rotation (rotation of the contents of the nucleus). Intranuclear rotation includes both nuclear membranes, but without causing the cytoplasm to rotate. Therefore there may be a layer just outside the outer nuclear membrane that has low viscosity, like the cell cortex. If this is the case, the motive force is occurring on the outside surface of the outer nuclear membrane. In some cells nuclear rotation and cell membrane rotation are coupled.

The cytoskeletal elements in the nucleus combine with a variety of nuclear proteins forming a “nuclear matrix” which acts like a scaffold on which the DNA is attached. For this reason the whole lot is referred to as the “nucleoskeleton”. The nucleoskeleton itself is then connected to the cytoskeleton that is outside the nucleus via proteins that bridge the two nuclear membranes.

These three filaments, tubulin, intermediate filaments and actin were once thought to be unique to eukaryotes. Many old textbooks included a table of differences between eukaryotes and prokaryotes and the presence of cytoskeletal elements figured prominently as a defining characteristic of the eukaryotic cell. This has proven to be incorrect, and as we showed in Chapter 1, many characteristics of eukaryotes are found in, if not inherited from, prokaryotes. Homologs of all three cytoskeletal proteins have been found in bacteria, albeit usually having different functions. There is a form of tubulin found in bacteria called FtsZ that is also required for cell division in most prokaryotes (but not all), which may represent the evolutionary precursor of all of the tubulins

.This book excerpt is introduction to Chapter 5, “The Cytoskeleton” in “Embryogenesis Explained”.

(Ultimately) Alone in the Universe, by Richard (Dick) Gordon

Loeb2015

I was trying to convince Abraham (Avi) Loeb to join me as an editor of Habitability of the Universe before Earth (HUBE), a book I’m planning in the new book series Astrobiology: Exploring Life on Earth and Beyond (World Scientific Publishing, London) with series editors Joseph Seckbach (Israel), Pabulo Henrique Rampelotto (Brazil) and me (Canada & USA). Now, as Natalie and I have long observed, organizing scientists is much like herding cats. Avi turned me down, despite saying he is very drawn to the subject, on the basis that he is writing yet another book (Books by Abraham Loeb) and that he is heading some sort of award giving group (Breakthrough Initiatives Project of the Breakthrough Prize Foundation). Then he sent me his latest book, available only in Kindle format, From the First Star to Milkomeda. (He did not ask me to do this review.) Milkomeda refers to the result of collision of our Milky Way Galaxy with the “nearby” Andromeda Galaxy “within a few billion years”. Whew! Imagine trying to absorb and assimilate migrants from another 100 billion planets.

This is a semi-autobiographical account of a fine mature scientist and academic who has reached the peak in his career. By reading this book you can see how his mind works and sense his high personal and academic standards. You can also sense the intense loneliness that comes with reaching such a place. It’s a weird book giving you a view most people never see, the workings of an imaginative, clever, sharp, yet careful mind. He is a theoretician, par excellence, with substantial immunity from the grant system and the committees who decide who gets viewing time on expensive, communal telescopes. As a theoretical biologist I understand this independence. It allows our ideas to pour forth.

Avi thinks big. His latest work is on the earliest formation of water in our universe, and the possibility that life developed way back when. I have long been annoyed with the many books on the origin of life that presume, without discussion, that life began on Earth. This is one of the last anthropocentrisms, the first being that Earth is the center of the universe. I had an opportunity to knock the idea down a bit when Alexei Sharov and I wrote Life Before Earth. He came at the problem from a biological point of view, extrapolating a measure of organism complexity back in time, and I helped spell out the consequences. Avi calculates the first time the universe had places warm and cool enough to support liquid water. Both calculations allow for life for most of the 13.6 billion years our universe has been around, not just the paltry 4.54 billion years since the formation of our solar system.

When you start Milkomeda, you think you are about to be treated to a proper autobiography, farm boy near Tel Aviv rocketing to theoretical astrophysicist. But the book in short order plunges into the kind of language one expects in grant applications, giving only hints of Avi’s personal life. As all of Avi’s work is new to me, his 500 or so papers not having crossed my computer desktop previously, I saw past the “justifications” in the grant style of writing to fascinating ideas, like stars doing sling shots around pairs of black holes to achieve speeds near the speed of light. What a ride! Now I have to know whether life on planets around such flying stars would have any chance of surviving the trip? If so, we’d have a mechanism that could spread life well beyond the confines of galaxies. Close encounters with black holes are tales worth telling. I really enjoyed this.

Avi has reached that point in scientific life where he gives much thought to mentoring. A substantial portion of Milkomeda is devoted to the cultivation of the minds of young astrophysicists, trying to strike a balance between them towing the line and being obnoxiously creative. Here Avi shows he is one of us unherded cats. Did you ever hear of a labor union of scientists? No such thing. I’m still nominally President of CARRF, the Canadian Association for Responsible Research Funding, whose members have long since dispersed or departed Earth. My cofounders rejected my preferred moniker UNFUN, the Union of Unfunded Scientists. But under the CARRF banner, we produced much peer reviewed and other literature on how to improve/replace the peer review system for grants. Avi has rediscovered many of these ideas, our tiltings at windmills, unaware of our published efforts. So many scientists independently come to these conclusions, but ununionized, nothing happens. The shame of it all is that the taxpayer, who foots most of the bill for scientific discovery, gets far less bang for the buck than should be possible. I so completely agree with him but I found the whole topic maddening to read about, again. He gives ten specific examples in astrophysics of scientists suppressing the research of other scientists they thought were wrong. It is a warning for anyone who practices science by consensus. If you are someone who has looked with curiosity at the inner workings of astrophysics and wondered what being in the field is about, this book will give you keen insights.

Good ole Lord Kelvin predicted the Heat Death of the Universe, back before nuclear energy was discovered, a rather depressing scenario. Avi, while holding his head high in contemplating the universe on the cover of Milkomeda, points out that with the universe expanding, most of the galaxies we see beyond our local cluster will vanish from the sky. Their light will not reach us, because the rate of expansion of the universe exceeds the speed of light. Somehow gravity will keep our small corner of the universe intact, but alone. Well, perhaps: another depressing outcome. But maybe we could hitch a ride around that pair of black holes from the Milky Way and Andromeda as they hurl towards each other, and be out of here. Stay tuned. And buy the book. You still have time.

Diatom Motility – Explosive Breakthrough in Understanding

Slide08

There are several models of how diatom motility works:

Snail-like movement (proposed by Christian Gottfried Ehrenberg in 1838)

Jet engine like motion using a form of jet propulsion (proposed by Carl von Nägeli in 1849, modified by C.Th. von Siebold in 1853), long before the jet engine was invented!

Rowing model (proposed by J. Hogg in 1855)

Rocket ship model: O. Bütschli (1892) and Robert Lauterborn (1896) proposed that a sticky jelly-like substance, extruded quickly in fine threads at the nodules of the raphes, propels the cells by mechanical recoil.

Extroproplasm streaming model think of a tank tread (proposed by Otto Müller in 1893)

And then there is capillarity (Flame of Life) model: Slide24

Slide25

A new competing model by Lesley Edgar and Jeremy Pickett-Heaps (1983) proposes that the raphe fibers are passively carried by myosin motor molecules.

The problem of diatom motility is still unsolved.

Lesley Ann Edgar (1955-2006) analyzed movie films of motile diatoms at 10 frames per second and noted erratic accelerations to 100 µm/sec2 (see Edgar, L.A. (1979). Diatom locomotion: computer assisted analysis of cine film. Br. Phycol. J. 14, 83-101.)

  • “It is possible that such a strand is secreted in short units corresponding to release of individual loads of locomotor material from within cytoplasmic vesicles through the plasmalemma, so that locomotion would occur in a series of steps” (Edgar, L.A. (1979). Diatom locomotion: computer assisted analysis of cine film. Br. Phycol. J. 14, 83-101.)

Hm….very interesting result. So we (working with Can Sabuncu and Ali Beskok at Southern Methodist University) followed up, and got the same result, even though our camera is nearly 1000 times faster:

Slide29

We may be seeing very high speed forward and backwards movement. So maybe the rocket propulsion model is right: strands of mucilage are extruded along the raphe. They hydrate on contact with water exiting the raphe in chemical explosions. These repeated explosions move the diatom along in spurts. The mucilage is left behind as the sticky “diatom trail”. Its elasticity sometimes pulls the diatom backwards as the connection with the trail is stretched and breaks.

Is this correct? We need more research. Our next plan includes computer simulation:Slide36

This blog is a summary version of:

History and future of understanding the mechanism of diatom motility
6TH INTERNATIONAL VERESHCHAGIN
BAIKAL CONFERENCE
AND 4TH BAIKAL SYMPOSIUM ON MICROBIOLOGY (BSM-2015)
MICROORGANISMS AND VIRUSES IN AQUATIC ECOSYSTEMS
September 7-12, 2015

Richard Gordon

Gulf Specimen Aquarium & Marine Laboratory, Panacea, Florida, USA

Ali Beskok & A. Can Sabuncu

Department of Mechanical Engineering

If you would like a copy of the full presentation, please send us a message.