Courtesy Mark RyanBirds seem to be a big part of my recent experience, so I thought I'd put together a little post of events featuring our fine, feathered friends.
Here at the Science Museum of Minnesota, an antique model of Archaeopteryx originally created by modelmaker Gustaf Sundstrom in 1934 is on display once again as Object of the Month for October.
Courtesy Mark RyanArchaeopteryx has long been considered the earliest bird - it lived around 150 million years ago during the Late Jurassic - sharing the world with giant sauropods and vicious therapods such as Apatosaurus and Allosaurus, respectively. Even though Archaeopteryx has been recently re-categorized from being a "dinosaur-like bird" to being a "bird-like dinosaur" (I'm not sure what the difference is but I suspect it has do do with percentages) - anyway, it still ranks as one of the great transitional fossils. You can see the Object of the Month display in the Collections Gallery on the 4th floor of the Science Museum of Minnesota all this month.
Another bird-related story deals with naturalist and artist John James Audubon and his artistic masterpiece Birds of America, both which I've covered before here.
Courtesy Mark RyanBack in the early 19th century Audubon, tramped around the American frontier seeking just about every kind of bird he could find, shoot, and paint for his masterpiece natural history tome, Birds of America. The original edition featured 435 exquisite plates of birds drawn in natural size, were etched in copperplates (along with some engraving and aquatint), then printed in black and white and printed on large double-elephant folio-sized (30 x 40) handmade paper. Each of the large black and white prints were hand-painted in watercolors by a team of skilled colorists and bound into two volumes. Long considered one of the greatest collections of natural history illustration, only some 200 sets were completed in the mid-19th century. Of those only about 100 remain in existence. The rest were either destroyed or disassembled and sold off as individual prints. Because they were hand-colored, these large first editions are considered "originals" and are quite valuable. Smaller, more inexpensive prints and editions were later created and sold.
Courtesy Mark RyanLucky for us one of the original Double Elephant Folio sets is held by the Bell Museum of Natural History in Minneapolis. Even luckier for us, the Bell has just opened a brand new exhibit, called Audubon and the Art of Birds, which is centered around some of these beautiful originals of Audubon's wonderful illustrations. I attended the preview a couple weeks back and let me tell you, it is a chance in a lifetime to see these rare and beautiful natural history illustration masterpieces. The exhibition opened on October 5th and runs in two sections. Right now, 33 of Audubon's mammoth prints grace the walls of the exhibit (along with illustrations by other bird artists) then other restored mammoth prints of Audubon illustrations will be rotated in during a two week shutdown in January, and the exhibit's second half reopens on February 1st. Find more information about the exhibition here.
Courtesy Mark RyanLast week, my wife and I took a day-trip to Duluth and stopped at Hawk Ridge Bird Observatory, located on Skyline Parkway overlooking the east end of the city. The site is a favorite autumn destination for bird-watchers of all kinds.
Courtesy Mark RyanOfficial bird-counters were still there tabulating hawks, eagles and other raptors migrating south for the winter. The count will continue through October.
Courtesy Mark RyanThe birds don't like crossing the wide expanse of Lake Superior on their way south, so they funnel into Duluth to cross there. We only saw a couple birds in the air while we were there (some 680 had been counted earlier in the day), but a couple of hawks snared just down the road were brought up to the ridge overlook for banding and release. Volunteers tagged and recorded the hawks (a goshawk - Accipiter gentilis - and a sharp-shinned hawk - Accipiter striatus), then enlisted the help of a couple of lucky onlookers to release them back into the wild. It was a beautiful afternoon on the Ridge.
Courtesy Mark RyanA new study appearing in Biology Letters shows that trilobites - everyone's favorite prehistoric water bug - developed an effective survival strategy much earlier than previously thought.
Trilobite fossils from Early Cambrian rock formations in the Canadian Rockies and elsewhere lend evidence that some of the earliest trilobites used enrollment (i.e rolling themselves up into a ball like an armadillo) to protect themselves from predators or the environment. Trilobite fossils found here in Minnesota are several million years younger dating back to the Late Cambrian through Late Ordovician Periods (500 - 430 mya) and are often found enrolled. It was an effective survival strategy.
Trilobites were arthropods, which meant they possessed exoskeletons, segmented bodies and jointed appendages. Their closest extant relative is the horseshoe crab. Trilobite bodies - for the most part - were comprised of a head (cephalon) positioned on a body (thorax) that was divided into three lobes: essentially an axial dividing a left and right pleura, and a tail (pygidium). The mouth (hypostome) was located on the underside. It's thought that most early trilobites were predators and/or scavengers who spent their lives roaming the sea floors looking carcasses, detritus or living prey to feed upon. Most trilobites possessed complex eyes (although some were eyeless). Like other arthropods (e.g. today's lobsters), trilobites would outgrow their exoskeletons, discarding them (molting) as they grew in size or changed shape. Their newly exposed soft skin soon hardened into a new, tough, outer casing. Once hardened, their segmented exoskeletons (composed of calcium carbonate) were ventrally flexible, giving them the ability to roll up into a ball should they need sudden protection from whatever threatened them.
Some early trilobite forms from Middle Cambrian-aged fossils had been viewed as incapable of enrolling but the new research based on much older fossils found in mudstones in the Canadian Rockies in Jasper Park pushes back the origins of the strategy to some of the earliest trilobites to appear in the fossil record (Suborder Olenellus). These appeared 10-20 million years earlier at the very beginnings of the Cambrian Period and show evidence of having already developed the ability to enroll.
Trilobites in some form or another existed across a span of more than 270 million years, a very successful run by any measure. The enrollment strategy certainly contributed to their longevity. Although trilobites were already in decline, the last of their kind were wiped out in the great extinction event that marked the end of the Permian Period and the start of the Triassic. They weren't the only casualty of the extinction: nearly 90 percent of Earth's species were terminated along with them.
Even though trilobites are extinct (they died out in the Permian Mass Extinction along with around 90 percent of Earth's species) they were an extremely successful and adaptable life form. No wonder they remain today a favorite among fossil collectors.
Courtesy Wikimedia - en:User:Fir0002Eden Steven, a physicist at Florida State University is developing ways to possibly conduct electricity using spider webs and carbon nanotubes.
A carbon nanotube is a one-atom thick sheet of carbon that’s been rolled into a tube. A nanotube’s diameter is at least 10,000 times smaller than a strand of human hair. Carbon nanotubes are strong and have been found to conduct electricity and heat.
Florida State University reports Steven used just a drop of water to attach powdery carbon nanotubes onto spider silk. He gathered the spider silk himself, using a stick to gather webs outside his lab.
The experiment has drawn much national attention. “It turns out that this high-grade, remarkable material has many functions,” Steven said of the silk coated in carbon nanotubes. “It can be used as a humidity sensor, a strain sensor, an actuator (a device that acts as an artificial muscle, for lifting weights and more) and as an electrical wire.”
Steven wanted to investigate eco-friendly materials and was especially interested in materials that could deal with humidity without complicated treatments and chemical additives.
“Understanding the compatibility between spider silk and conducting materials is essential to advance the use of spider silk in electronic applications,” Steven wrote in the online research journal Nature Communications. “Spider silk is tough, but becomes soft when exposed to water. … The nanotubes adhere uniformly and bond to the silk fiber surface to produce tough, custom-shaped, flexible and electrically conducting fibers after drying and contraction.”
To learn more about Eden Steven's work visit:
To learn more about nanotechnology, science, and engineering, visit:
To see other nano stories on Science Buzz tagged #nano visit:
Courtesy ap2il via FlickrOne of the strangest creatures to emerge from the famed Burgess Shale in the mountains of British Columbia, is the rightly named Hallucigenia, a strange spiky, wormlike creature that once scuttled across the Cambrian sea bottom more than 500 million years ago. Originally considered a totally unique (and baffling) creature, Hallucigenia has now been linked to other similar-aged wormlike creatures found around the world.
Hallucigenia first came to light in 1909 after Charles Doolitle Walcott, an expert in trilobites and secretary of the Smithsonian Institute, discovered a Lagerstätte in the mountains of British Columbia that was unlike any other found before.
Courtesy Mark RyanLocated in Yoho National Park on a steep slope between Mount Field and Wapta peak above the railroad town of Field, B.C., Walcott's quarry produced some of the strangest creatures - many of them soft-bodied and rarely found in the fossil record. The rock section, previously known as the Stephens Formation became known as the Burgess Shale, after nearby Burgess Pass. In the years following the discovery, Walcott and other scientists studied the strange fossils in an effort to decipher them and the environment in which they had lived and died.
Because of the high degree of preservation, the creatures that made the fossils were most likely buried suddenly in some sort of giant underwater mudslide that quickly entombed an entire marine community in an anoxic environment where decomposition was stifled. A perfect environment for preserving the soft-bodied tissue.
Courtesy Mark RyanSome of the Burgess Shale denizens appeared to be of completely new and unknown phyla with bizarre and unfamiliar body plans and no known descendents in the modern age. Hallucigenia certainly led the pack in this department. The tiny strangely constructed worm was only about an inch in length and confounded Walcott and other scientists for more than a century. They couldn''t even say for sure which side was up or down. Early Hallucigenia fossils showed a row of seven tentacles along one side. The opposite side contained seven sets of stiff spikes that were interpreted to be legs. A truly bizarre, aptly named freak-show creature that would be right at home in your average nightmare.
New evidence can often turn an old idea on its ear - or in this case, on its back. Recent scrutiny of newer, better-defined Hallucigenia fossils has revealed another set of "tentacles", leading scientist to realize they had Hallucigenia all flipped around. What they once thought was its top side was actually its bottom. Its dorsal "tentacles" were actually its legs. And its spiky "legs" belonged on its back, probably to serve as protection against predators.
This information along with a new study published in Proceedings of the Royal Society B now places Hallucigenia within a group of other worm-like creatures whose fossils are found around the world, including China, Canada, Great Britain, and Australia. It also links it to a living group - Onychophora - the velvet worms that mostly inhabit the tropical forests of the Southern Hemisphere.
"They may not be exactly the same species, but they are all probably related to the same group of worm-like creature that we call lobopods," said Dr. Jean-Bernard Caron, curator of invertebrate paleontology at the Royal Ontario Museum and the study's lead researcher. Caron is an expert in Burgess Shale fossils and his study of Hallucigenia and other fossils from the formation continues to glean new knowledge about the strange creatures that existed in the so-called Cambrian Explosion. Check out Caron's Burgess Shale website. It's full of great information about the quarry and the incredible fossils found there.
Courtesy Mark RyanWalcott's Burgess Shale quarry has been designated a World Heritage site. The only way to visit it (or the fossil fields on nearby Mt. Stephen) is through guided hikes led by either Parks Canada or The Burgess Shale Geoscience Foundation. The 10 hour round-trip hike (rated moderate to difficult) takes participants up 2500 feet in elevation to Mt. Fields and requires reservations and a deposit. Fossil collecting is prohibited but the views are said to be spectacular.
SOURCE and LINKS
The Province story
The Burgess Shale at Smithsonian website
Dr. Caron's Burgess Shale website
Parks Canada Burgess Shale info
Tired of the constant din and bustle of modern life? Is the noise of screaming children or the neighbor's yapping miniature collie turning you into a nervous nelly? Maybe what you need is a place where you can go for some real top-notch peace and quiet.
That place could very well be the special anechoic chamber located at Orfield Laboratories right here in the Twin Cities. The chamber, which is hidden behind two vault doors, has 3.3-foot-thick fiberglass sound-deadening fiberglass acoustic wedges covering all of its flat surfaces, so instead of bouncing off the walls, ceiling, and floor as in a traditional room, any sounds are absorbed. I'm talking absorbed almost completely - the double-walled steel and concrete room is, in fact, 99.99 percent absorbent. That's a lot of quiet! Humans can't detect any sound registering below 0 dBA, and the Orfield chamber has a decibel rating of −9.4 dBA! The space is so soundproof it's listed in the Guinness Book of World as the "Quietest place on the planet."
Of course, there are some side effects to being thrust into utter silence. One is that the sounds inside your own body, your breathing, stomach gurgles, and of blood rushing through your veins become quite pronounced. "In the anechoic chamber, you become the sound," says lab president and founder Steven Orfield.
Be aware that it's not that easy being in a totally silent environment. The longest anyone has been able to withstand the sensory deprivation of the chamber is 45 minutes. And even short spells of dead silence can trigger hallucinations. The brain just doesn't like being deprived of sensory input.
Orfield's anechoic chamber has been used by several industries, including Harley-Davidson, Whirlpool, and airlines to test product sound levels, and by NASA to test the ability of astronauts to function in the extreme silence of space where, as they often say, no one can hear you scream.
Our great-ape cousins such as chimpanzees have feet that are very flexible in their middle region due to something called the midtarsal break that allows their feet to bend in the middle, enabling them to grasp at branches for easier climbing through trees. So when a chimp lifts his foot off the ground, it just flops about - there's nothing to hold the bones together. Most humans, on the other hand (or should I say foot?), have the same joint but have ligaments that stretch across it making the foot more rigid and stable for upright walking. Australopithecus sediba, a human ancestor that lived 2 million years ago, has a foot structure that is more ape-like than human, so somewhere along the line our feet evolved probably to accommodate our bipedalism.
The study was done by Jeremy DeSilva, a functional morphologist from Boston University, whose main interest is the evolution of the human foot and ankle. In this recent study, museum visitors were requested to walk barefoot across a mechanized carpet while DeSilva's team observed their gaits and the structure of their feet as they walked.
The surprising results showed that 8 percent of the nearly 400 participants possessed a flexible midtarsal break in their foot, and displayed a pressure signature in their footprint that looked like that found in the footprints of non-human primates. Perhaps more surprising is the fact that those subjects who had the unusual foot-joint structure weren't even aware of it until DeSilva revealed it to them.
The study was published in the American Journal of Physical Anthropology.
Courtesy Stevenfruitsmaak via Wikimedia CommonsWhen a cancer cell (a tumor) appears in a particular organ or area of a body, it somehow signals the body's immune system to back off and leave it alone. This allows the cancerous tumor to grow and eventually metastasize to the lymph nodes and other parts of the body. It's as if the cancer grants itself a sort of diplomatic immunity against the body's natural antibodies from interfering with its destructive undertakings.
Now, researchers have found a drug that switches off this "don't touch" warning and allows the cancer to be diminished or entirely destroyed. And it works for several types of cancers, including those affecting the brain, liver, colon, breast, ovary and prostate.
A protein called CD47 is present in human blood cells and prevents those cells from being attacked by the body's immune system. The protein attaches to the surface of the blood cells and signals to the immune system that the blood cells are "okay" and shouldn't be destroyed. About ten years ago, biologist Irving Weissman and researchers at Stanford University's School of Medicine noticed higher levels (up to 3x more) of the same "don't touch" protein were present in leukemia cells, a blood disorder. The surprised Weissman realized that the blood cancer was co-opting the body's own defense system to work against itself, thereby stopping any attacks on the cancer. This left the cancer unmolested and able to grow and spread. After further testing, Weissman and his colleagues subsequently discovered that CD47 levels in many other cancers were also higher than levels in normal cells.
"What we've shown is that CD47 isn't just important on leukemias and lymphomas, it's on every single human primary tumor that we tested.“
The Weissman lab has now developed a promising drug that switches off this "don't touch" signal in cancer cells giving the body's immune system the green light to go after them. The drug has been tested in the laboratory using petri dishes containing treated and untreated cancer molecules. Immune cells (macrophages) were present in each sample. In the untreated sample, the macrophages ignored the cancerous molecules, while they readily attacked those treated with the anti-CD47 drug. In later tests, a variety of human cancer tumors were placed into lab mice and left to grow for two weeks. After the tumors grabbed hold, they were treated with the anti-CD47 therapy and the tumors shrunk considerably or disappeared altogether.
"The microenvironment of a real tumor is quite a bit more complicated than the microenvironment of a transplanted tumor," Weissman said, "and it's possible that a real tumor has additional immune suppressing effects."
The biologist is confident that the research will eventually move into human clinical trials within the next two years.
Courtesy Andy Field (Field Offie)Researchers at Virginia Tech are working on several versions of robotic jellyfish that someday could be used by the military, or for mapping the ocean floor, or cleaning up oil spills.
Known affectionately as RoboJelly, the silicone blobs range from the size of a baseball to a giant five-foot floating monster. Each mimics the swimming technique used by jellyfish, those huffing and puffing water-bags that populate the world's oceans.
In nature, most jellyfish propel themselves by the seemingly simple expansion and contraction of their umbrella, using it to push water out like a rocket blast that propels it forward. But the fluid dynamics are a little more complicated than than just expelling out a big blast of water and moving the other way. It's more like when your cigar-smoking uncle would blow smoke rings into the air to impress you. Remember that? I do. These are called vortex rings, and it's the efficiency of the hydromedusean's self-created fluid flow that interest the VT researchers.
Students at VT's College of Engineering use thin layers of silicone - the same material used for swimming masks - to construct the robots. Electric batteries in watertight plexiglass boxes are used to power the mechanical blobs. The researchers are also looking into ways of extracting hydrogen from water to power them.
“Nature has done great job in designing propulsion systems but it is slow and tedious process," said Shashank Priya, associate professor at Virginia Tech, and the project's lead researcher. "On the other hand, current status of technology allows us to create high performance systems in a matter of few months.”
The on-going project involves a number of U.S. universities and industries, and will warrant several additional years of research before any prototypes are released for use. Besides possible military application, RoboJelly could be employed for such things as monitoring ocean currents and conditions, cleaning up oil spills, and studying sea-bottom flora and fauna.
Courtesy Fancy Horse (underwater background)The genome of the coelacanth, the world's best known living fossil, has been sequenced by an international team of researchers and is revealing something scientists already suspected: that the primitive-looking fish has evolved more slowly than most other organisms. The coelacanth is related to the lungfish and several extinct Devonian fish species that are considered precursors to land dwelling tetrapods. Kerstin Lindblad-Toh is senior author of the study which appeared recently in the science journal Nature.
"We often talk about how species have changed over time, but there are still a few places on Earth where organisms don't have to change, and this is one of them," Lindblad-Toh said. "Coelacanths are likely very specialized to such a specific, non-changing, extreme environment -- it is ideally suited to the deep sea just the way it is."
Lindblad-Toh is scientific director of the Broad Institute's vertebrate genome biology group in Cambridge, Massachusetts, which did the genome research. The institute is linked to both MIT and Harvard.
The genetic map, which involved sequencing some 3 billion letters of DNA, also showed (via RNA content) that tetrapods - four-legged land dwelling animals - though related to both coelacanths and lungfish, are more closely related to lungfish and followed that line rather than that of the coelacanth. We humans also branched off that same line. The genome of a lungfish is composed of over 100 billion DNA letters, making it a much more difficult task to sequence, so for the time being, the coelacanth's DNA makes for a reasonable alternative for study.
"This is just the beginning of many analyses on what the coelacanth can teach us about the emergence of land vertebrates, including humans, and, combined with modern empirical approaches, can lend insights into the mechanisms that have contributed to major evolutionary innovations," said professor Chris Amemiya at the University of Washington, and the paper's co-author.
Courtesy photo by Haplochromis via Wikipedia Creative CommonsWhen Louis Agassiz named the first fossil coelacanth back in 1836, the Swiss paleontologist probably never imagined that a nearly identical descendent of the primitively constructed Devonian-aged fish would one day be found still inhabiting the world's oceans. The coelacanth was thought to have gone extinct along with the non-avian dinosaurs at the end of the Cretaceous period. None have been found in the fossil record after that time, but two extant species are known today. The first specimen Latimeria chalumnae was netted off the coast of South Africa in 1938, near the Chalumnae river and retrieved by East London Museum curator Marjorie Courtenay-Latimer who discovered what she called "the most beautiful fish I'd ever seen" in the catch of local fisherman, Henrik Goosen. Since then several more coelacanths have been caught, including the Indonesian species, Latimeria menadoensis, from the Indian Ocean.
The remarkable prehistoric throw-back, sometimes referred to as "old four legs" because of its leg-like fins, hasn't changed much in its 350 million year history. A member of the clade of lobe-finned fishes called Sarcopterygii, coelacanths retain primitive characteristics such a notochord, a hollow fluid-filled tube made of cartilage that underlies the spine over the length of its body. In all other vertebrates, the notochord is an anatomical structure that appears briefly only during the embryonic stage but not in adults. Not so with the coelacanth. It also possesses, primitive shark-like intestines, a linear heart, and tightly-woven armor-like scales (known as cosmoid) that are only found on extinct species of fish. The coelacanth's brain case contains only 1.5 percent gray matter - the other 98.5 percent of space is filled with fat. The other end of the coelacanth body begins to taper before expanding into a strange, three-lobed tail. Its most notable features are its lobed pectoral and pelvic fins that are structured with bones that look like toes, and move in an alternating tetrapod manner. An electroreceptive rostal organ located in its snout is used to detect prey, and the coelacanth is the only living animal that can unhinge a section of the its cranium to increase the gape of its mouth, enabling it to consume larger prey.
The blue or brown, white-speckled coelacanths prefer deep-water environments, and can reach six and a half feet in length and weigh upwards to 175 pounds. For some reason no living coelacanth has managed to survive more than a single day in captivity. With a dwindling population estimated at only 500-1000 individuals, the coelacanth was declared an endangered species in 1989.
SOURCE and LINKS