Wednesday, October 31, 2012

Acronym in cytology and organogenesis: SFEBq for serum-free floating culture of embryoid body-like aggregate with quick reaggregation

SFEBq stands for serum-free floating culture of embryoid body-like aggregate with quick reaggregation. A complex acronym for a complex process! This cell-aggregation process occurs in three-dimensional culture solutions (instead of  single-layer dish cultures), wherein floating stem cells self-assemble into complex tissue topologies—depending on fine-tuned experimental conditions and supply of chemical precursor compounds. SFEBq technology was developed to explore artificial growth of  protoretina resembling the neural retina in mammalian eyes [1-4].

The successful SFEBq-driven retina growth, including the development of the optic vesicle and its structural collapse to form the optic cup, demonstrates that building and shaping of a retina can occur without support from neighboring tissues such as lens cell. In the words of Yoshika Sasai, a neurobiologist at RIKEN Center for Develiopment Biology in Kobe, Japan [4], “retinal formation, at least in vitro, is a self-organizing phenomenon based on an internal program that resides within these cells.” 

Keywords: molecular neurobiology, organogenesis, neurogenesis, compound tissue, neuroepithelium, mammalian embryogenesis, embryonic stem cells.

References, cell-adhesion figures,  schematic diagram and further reading
[1]  M. Eiraku , N. Takata, H. Ishibashi, M. Kawada, E. Sakakura, S. Okuda, K. Sekiguchi, T. Adachi and Y. Sasai: Self-organizing optic-cup morphogenesis in three-dimensional culture. Nature April 7, 2011, 472, 51-56.
DOI: 10.1038/nature09941.
[2] Kurzweil Accelerating Intelligence: Stem cells used to create retinal tissue. April 7, 2011 [www.kurzweilai.net/stem-cells-used-to-create-retinal-tissue]. 
[3] M. Eiraku and Y. Sasai: Mouse embryonic stem cell culture for generation of three-dimensional retinal and cortical tissues. Nature Protocols 2012, 7, 69-79.
DOI: 10.1038/nprot.2011.429.
[4] Y. Sasai: Grow Your Own Eye. Scientific American November 2012, 307 (5), 44-49.
DOI: 10.1038/scientificamerican1112-44.

Thursday, October 18, 2012

Rhyming in harmony about dinosaur's anatomy

Bert Leston Taylor (1866-1921), using B. L. T. as his initials, was writing humorous columns for newspapers [1-3]. He also engaged in writing comic and delightful verses, which often expose some little-noted wisdom or truth. One of my favorite poems is The Dinosaur, in which B. L. T. referred to the ‘second brain’ (large ganglion in the pelvis) of some dinosaurs [4-6]: 
Behold the mighty dinosaur,
Famous in prehistoric lore,
Not only for his power and strength
But for his intellectual length.

You will observe by his remains
The creature had two sets of brains -
One in his head (the usual place),
The other at his spinal base.

Thus he could reason A priori
As well as A posteriori.
No problem bothered him a bit
He made both head and tail of it.

So wise was he, so wise and solemn,
Each thought filled his spinal column.
If one brain found the pressure strong,
It passed a few ideas along.

If something slipped his forward mind
'Twas rescued by the one behind.
And if in error he was caught
He had a saving afterthought.

As he thought twice before he spoke
He had no judgement to revoke.
Thus he could thing without congestion
Upon both sides of every question.

Oh, gaze upon this model beast,
Defunct ten million years at least.
............>> Bert Leston Taylor <<
Conclusion:
With two brains quite distinct, dinosaurs yet went extinct!

Keywords: comparative anatomy, nerve trunk, educational rhyme, poetry, humor, anthropomorphizing.

References
[1] New York State Literary Tree: Bert Leston Taylor [www.nyslittree.org/index.cfm/fuseaction/DB.PersonDetail/PersonPK/1655.cfm].
[2] Evi: Bert Leston Taylor biography [www.evi.com/q/bert_leston_taylor_biography].
[3] Bert Leston Taylor: The So-Called Human Race. Alfred A. Knopf, New York, 1922 [activefolio.com/files/ET31138.pdf].
[4] Karen's Poetry Spot: The Riddle of The Dinosaur by Bert Leston Taylor. October 16, 2007 [karenspoetryspot.blogspot.com/2007/10/riddle-of-dinosaur-by-bert-leston.html].
[5] The Dinosaur [www.readbookonline.net/readOnLine/50593/].
[6] Richard Dawkins: The Greatest Show on Earth. Free Press, New York, 2009; page 306.

Wednesday, October 10, 2012

An English-American mess: the term ‘turtle’


Do you think you know what a turtle is?

A dictionary definition sounds like this: “any of various chelonian reptiles, especially those of the marine family Chelonidae, having a flattened shell enclosing the body and flipper-like limbs adapted for swimming.” That's for the “English turtle.” US and Canadian turtles are “any of the chelonian reptiles, including the turtoises and terrapins.” [1]

There is a better understandable (and funnier) illustration of this subject in Richard Dawkins' book with the title The Greatest Show on Earth [2]. Quoting George Bernhard Shaw's saying that “England and America are two countries divided by a common language,” Richard Dawkins continues:

In Britain, turtles live in the sea, tortoises live on land and terrapins live in fresh or brackish water. In America all these animals are ‘turtles,’ whether they live on land or in water.  ‘Land turtles’ sounds odd to me, but not to an American, for whom tortoises are the subset of turtles that live on land. Some Americans use ‘tortoise’ in a strict taxonomic sense to refer to the Testudinidae, which is the scientific name for modern land tortoises.In Britain, we'd be inclined to call any land-dwelling chelonian a tortoise, whether it is a member of the Testudinidae or not.

What a mess! In case you wonder, Australians use the word turtle in yet different ways.

Any solution to this linguistic jumble? Zoologists, in their research, use the term chelonian. Broad-based aspects of the conservation and biology of these animals are covered in an international scientific peer-reviewed journal: Chelonian Conservation and Biology [3].

Like the scientific language, the German language has one word for all: Schildkröte for turtle, tortoise and terrapin [4]. Schildkröte literally means shielded toad. A terrapin is a Sumpfschildkröte, Sumpf meaning swamp or bog.

Keywords: languages, terminology, biology, Testudinidae, Chelonidae, nomenclature, taxonomy, classification, confusion.

References and more to explore
[1] Dictionary.com: turtle [dictionary.reference.com/browse/turtle?s=t].
[2] Richard Dawkins: The Greatest Show on Earth. Free Press, New York, 2009.
[3] Chelonian Conservation and Biology [www.chelonian.org/ccb/].
[4] Edmund Launert: Biologisches Wörterbuch. Verlag Eugen Ulmer, Stuttgart, 1998.

Monday, October 8, 2012

One plant genus and 14 plant species named after Francis Guthrie, who first made the graph-theoretical Four-Color Conjecture

In 1852, the English law student Francis Guthrie at the University College of London conjectured that four colors would suffice to color any map, such, that border-sharing regions never come to share the same color [1-3]. The Four-Color Problem, or Four-Color Conjecture, turned into a theorem, when it was proven in 1976 by Kenneth Appel and Wolfgang Haken—a computer-assisted proof, triggering further work in theorem-proving software and strategies.  

Francis Guthrie (1831-1899) developed a strong interest in mathematics and botany. In 1861, Guthrie left England for the Cape Colony, now part of South Africa, where he took up the chair of Mathematics at the Graaff-Reinet College and, in 1878, at the South African College (Zuid Afrikaansche Athenaeum), which became the University of Cape Town in 1918 [2]: Besides mathematics, Guthrie taught botany; inspiring Harry Bolus (1834-1911), who later became a celebrated botanist and illustrator. Honoring his teacher, Bolus named a genus in the plant family Achariaceae after Guthrie: Guthriea Bolus, including the flowering plant Guthriea capensis [4].

Bolus also named plant species after Guthrie. For example, Satyrium guthriei Bolus (1893) in the family Orchidaceae, Gladiolus guthriei Bolus (1917) in the Iris family and Indigofera guthriei Bolus in the family Fabaceae [2,4-6]. 

Keywords: mathematics, graph theory, history, botany, plant species, flowering plants, taxonomy.

References and more to explore
[1] J. J. O'Connor and E. F. Robertson: The four colour theorem. September 1996 [www-groups.dcs.st-and.ac.uk/~history/HistTopics/The_four_colour_theorem.html].
[2] Pieter Maritz and Sonja Mouton: Francis Guthrie: A Colourful Life. The Mathematical Intelligencer 2012, 34 (2), pp. 67-75. DOI: 10.1007/s00283-012-9307-y.
[3] Georges Gonthier: Formal Roof—The Four-Color Theorem. Notices of the AMS December 2008, 55 (11), 1382-1393. PDF: www.ams.org/notices/200811/tx081101382p.pdf.
[4] JSTOR PLANT SCIENCE: Guthriea capensis Bolus [plants.jstor.org/visual/nbgsld0001378], Satyrium Guthriei Bolus [plants.jstor.org/flora/floc014377], Indigofera guthriei Bolus [plants.jstor.org/specimen/nh0005500-0]. 
[5] Victoria Wilman: Gladiolus guthriei F. Bolus [www.plantzafrica.com/plantefg/gladiolusguthriei.htm].
[6] Red List of South African Plants: Indigofera guthriei Bolus [http://redlist.sanbi.org/species.php?species=357-204].

Wednesday, September 26, 2012

Anchiornis, the “nearby bird”

The word Anchiornis defines a dinosaur genus: small, feathered, deinonychosauria (“fearsome claw lizards”) belonging to the family Troodontidae. The genus name Anchiornis is based on the Greek roots anchi and ornis, meaning “nearby” and “bird,” respectively. The name highlights the close relation between these feathered lizards of the Cretaceous period and birds [1].  Anchiornis huxleyi is currently the only known species of this fossil genus—included in the scientific name is an epithet that honors Thomas Henry Huxley (1825-1895), an English biologist, who pioneered research into avian origin.

A recent Keanium article in the journal Chemical Heritage shows a striking artist's rendering of Anchiornis [2]. The article describes how insight in the dinosaur-bird relationship (or evolution of birds) is gained by the study of pigments such as melanin, found in fossil feathers—dino fuzz. Identification and scanning electron microscope-supported analysis of fossilized and surviving melanosomes in proto-feathers of fossil animals from northeastern China allow the reconstruction of dinosaur and early bird's color patterns [3]. While the dinosaur-bird debate is still going on, proto-birds such as Anchiornis already shine in brilliant colors and bring art and science together.

Keywords: paleontology, anatomy, evolution, dinosaurs, birds, feathers, melanin.

References and more to explore
[1] Xu Xing et al.: A new feathered maniraptoran dinosaur fossil fills a morphological gap in avian origin. Chinese Science Bulletin 2008, 54 (3), 430-435. DOI: 10.1007/s11434-009-0009-6.
[2] Sam Kean (artist's rendering by Michael DiGiorgio): Colored In. Chemical Heritage Summer 2012, 30 (2), page 5 [www.chemheritage.org/discover/media/magazine/articles/30-2-colored-in.aspx].
[3] Chris Sloan: Dinosaur True Colors Revealed for First Time. National Geographic January 2010 [http://news.nationalgeographic.com/news/2010/01/100127-dinosaur-feathers-colors-nature/].

Sunday, September 23, 2012

Chompion: champion among strong-biting animals

Which is the hardest-biting land animal ever known? According to recent biomechanical studies, this is Tyrannosaurus rex, which—with a maximum bite force of 12,800 pounds—had a stronger bite than any other known terrestrial animal [1-4]. Only some water-based monsters such as extinct giant sharks and crocodilians had most likely a harder bite. Ouch!

They all made a living by forcefully chomping their prey apart inside their megamouth. T. rex is the chomp champion, chompion, of the land animals. Brian Switek uses this playful portmanteau in his recent Smithsonian article, reporting on the newest results in modeling and estimating bite force of large animals and referring to T. rex as the world chompion [4]. Congratulations!

Keywords: comparative anatomy, biomechanics, paleontology, evolution, biology, bite.

References and more to explore
[1] Jennifer Viegas: T. Rex Had The Toughest Bite. DiscoveryNews, Feb. 28, 2012 [news.discovery.com/animals/t-rex-bite-122802.html].
[2] BBC Nature: Tyrannosaurus rex bite measured [see a video: www.bbc.co.uk/nature/17197633]
[3] Brian Switek: The Tyrannosaurus Rex's Dangerous and Deadly Bite [www.smithsonianmag.com/science-nature/The-Tyrannosaurus-Rexs-Dangerous-and-Deadly-Bite-169806936.html].
[4] Brian Switek: World Chompion. Smithsonian magazine, October 2012, page 14.

Tuesday, September 18, 2012

Donner Summit Bridge and its other names

Donner Summit Bridge is a concrete arch span built during the 1920s. This landmark bridge, as part of the Old Lincoln Highway (Hwy 40), was then an important east-west artery between San Francisco Bay and New England. Now, Interstate 80 takes most of the traffic and the route leading over this bridge, called Hwy 40 Scenic Bypass, is favored by tourists and those who come to the Donner Pass area for hiking, biking, rock climbing, skiing and exploration of natural and Gold Rush history.

Donner Summit Bridge is commonly known as Rainbow Bridge. It also is named Donner Memorial Bridge, reminding visitors to memorize the fateful event of 1846 and 1847, during which many emigrants to California lost their lives. The vista point next to the Rainbow Bridge offers a great overlook of  Truckee's Donner Lake. This view point, as many other locations of interest along the scenic bypass, features informative panels illustrating the local history. More about the Donner history can be learned around the Donner Party Memorial (Pioneer Monument) and in the Emigrant Trail Museum at Donner Memorial State Park at the east end of Donner Lake. 

Keywords: Sierra Nevada, geography, history, landmark name.