Category Archives: Education

Secrets of Spider Silk’s Strength

Secrets of Spider Silk’s Strength

The strength of a biological material like spider silk lies in the specific geometric configuration of structural proteins, which have small clusters of weak hydrogen bonds that work cooperatively to resist force and dissipate energy, researchers in Civil and Environmental Engineering have revealed.

This structure makes the lightweight natural material as strong as steel, even though the “glue” of hydrogen bonds that hold spider silk together at the molecular level is 100 to 1,000 times weaker than the powerful glue of steel’s metallic bonds or even Kevlar’s covalent bonds.

“Using only one or two hydrogen bonds in building a protein provides no or very little mechanical resistance, because the bonds are very weak and break almost without provocation,” said Buehler, the Esther and Harold E. Edgerton Assistant Professor in the Department of Civil and Environmental Engineering. “But using three or four bonds leads to a resistance that actually exceeds that of many metals. Using more than four bonds leads to a much-reduced resistance. The strength is maximized at three or four bonds.”

Related:Why a spider hanging from a thread does not rotate60 Acre (24 hectare) Spider Web

Mutation Rate and Evolution

Stop the Mutants! by Olivia Judson

I’m going to wave a magic wand and reduce the mutation rate to zero, instantly, in all species, and forever. Then I’m going to watch to see how long it takes for evolution to stop.

Actually stopping mutations is a physical impossibility – hence the need for a magic wand. But if they were to stop, so would raw invention. But evolution would not. Not for a long time.

And sometimes natural selection actively promotes the persistence of genetic variation. This can happen when there’s an advantage to having genes that are rare. Among guppies, for example, males with rare color patterns are much more likely to survive than those with common color patterns, presumably because predators get good at spotting the patterns they encounter often. In such situations, the rare type does well, begins to become common – and then becomes the victim of its own success and starts to do badly. In situations like this, the frequencies of different genes can rise and fall, cycling indefinitely.

Among lifestyles that promote genetic diversity, far and away the most important is sex. Sex shuffles up genes, continually producing new gene combinations. (An important difference between sex and mutation is that sex can only create genetic novelty if it already exists in the population. If everyone is genetically identical, sex will have no effect.) Sex also – and this is important – decouples the fates of genes from one another.

Good stuff. Related: Evolution is Fundamental to ScienceEvolution In ActionEvolution in Darwin’s Finches

2008 Intel Science Talent Search

2008 Intel Science Talent Search

When Shivani Sud was six years old, one of her immediate family members was diagnosed with a brain tumor. Inspired by the doctors who helped her loved one recover, Shivani set her sights on a career in medicine.

Fast forward to Intel STS 2008, where the 17-year-old senior from Durham, North Carolina, presented research focused on identifying stage II colon cancer patients at high risk for recurrence and the best therapeutic agents for treating their tumors. Whereas the standard method of characterizing tumors relies on visual information (such as size, degree
of metastasis, and microscopic structure), Shivani developed a “50-gene model” which uses gene expression to link multiple genetic events that characterize various tumor types to more accurately predict the recurrence of colon cancer. Additionally, Shivani’s model can be used to identify drugs that may be most effective in treating each patient.

In 2006 she attended the Davidson Institute, summer program at Davidson College and received the Davidson Fellows Scholarship.

And now I can segue to the Davidson Wildcats victories in the NCAA basketball tournament last weekend (I graduated from Davidson, by the way, and grew up in Madison). Davidson will play the Wisconsin Badgers on Friday. My picks are doing pretty well.

Related: 2006 Intel Science Talent SearchIntel International Science and Engineering Fair 2007

Ballast-free Ships

ballast-free ship’ could cut costs while blocking aquatic invaders

University of Michigan researchers are investigating a radical new design for cargo ships that would eliminate ballast tanks, the water-filled compartments that enable non-native creatures to sneak into the Great Lakes from overseas. At least 185 non-native aquatic species have been identified in the Great Lakes, and ballast water is blamed for the introduction of most—including the notorious zebra and quagga mussels and two species of gobies.

This week, the U.S. Saint Lawrence Seaway Development Corp. will implement new rules designed to reduce Great Lakes invaders. Ships will be required to flush ballast tanks with salt water before entering the Seaway, a practice corporation officials describe as an interim measure, not a final solution.

Instead of hauling potentially contaminated water across the ocean, then dumping it in a Great Lakes port, a ballast-free ship would create a constant flow of local seawater through a network of large pipes, called trunks, that runs from the bow to the stern, below the waterline.

“In some ways, it’s more like a submarine than a surface ship,” Parsons said. “We’re opening part of the hull to the sea, creating a very slow flow through the trunks from bow to stern.

Related: articles on invasive plantsInvasive Plants: TamariskSails for Modern Cargo Ships

Engineering Education Online Seminars

The Center for Engineering Educational Outreach has an engineering education seminar series that is available online: register for online broadcasts of all the remaining Tufts CEEO Seminar Series speakers for Spring 2008.

Some excellent seminars allow online participants are able to submit questions to the speaker via chat at the end of the seminar (time permitting). “Due to resource limitations, CEEO Spring 2008 Seminar Series are not currently being archived for later viewing or download.” That is a shame shame. They should post them on You Tube or SciVee or something. The advantage of asynchronous distribution of valuable content should be provided given the available tools today.

Seminars are at 4pm unless otherwise noted
Monday, Mar. 31 – The Robotic Fly: Innovations in very small robots. Rob Wood, Harvard University

Wednesday, April 9 (special time – 1:30 – in Nelson Auditorium) – Supporting Innovation: Engineers and Policy – Bill Wulf, University of Virginia.

Tuesday April 22 – LEGO Education: Looking Forward – Jens Maibom Vice President, the LEGO Group & General Manager, LEGO Education.

Monday, Apr 28 – Investigating Knowledge Fluency in Engineering Design– Ann McKenna, Northwestern University

Monday, May 12 – LEGO Americas – What does the future bring?- Soren Torp Laursen – President, LEGO Systems

Monday, June 2 – Conceptual Continuity: Using informal science literacies to promote students Science Learning – Bryan Brown, Stanford University,

Science Serving Society – Speech Australian Minister for Innovation

Kim Carr, Minister for Innovation, Australia, speech to the National Press Club of Australia: Science meets Parliament

When societies invest in science, they are investing in their own future. They are entitled to expect a fair return on that investment.

They’re entitled to know we are using the country’s intellectual and technical capacity to deliver outcomes that matter to them – stronger communities, more good jobs, a cleaner environment, better public services, a richer culture, greater security for themselves and their children. Everybody here knows the rules of professional scientific conduct – think independently, put emotion aside, reject received authority, be faithful to the evidence, communicate openly.

These are good rules – rules I wholeheartedly endorse – but there’s one more I’d like to add – remember your humanity. Remember you’re part of a wider society – one that you have a special ability and therefore a special duty to serve. This doesn’t just apply in the physical sciences, but in the humanities and social sciences as well. When I say science I mean knowledge in all its forms.

Related: Engineering Economic BenefitsAuthors of Scientific Articles by CountryEconomic Strength Through Technology LeadershipScience and Engineering in Global EconomicsAussies Look to Finnish Innovation ModelInvest in Science for a Strong Economy
Continue reading

6 Inch Bat Plane

image of bat plane

A six-inch robotic spy plane modeled after a bat would gather data from sights, sounds and smells in urban combat zones and transmit information back to a soldier in real time.

That’s the Army’s concept, and it has awarded the University of Michigan College of Engineering a five-year, $10-million grant to help make it happen. The grant establishes the U-M Center for Objective Microelectronics and Biomimetic Advanced Technology, called COM-BAT for short. The grant includes an option to renew for an additional five years and $12.5 million.

U-M researchers will focus on the microelectronics. They will develop sensors, communication tools and batteries for this micro-aerial vehicle that’s been dubbed “the bat.” Engineers envision tiny cameras for stereo vision, an array of mini microphones that could home in on sounds from different directions, and small detectors for nuclear radiation and poisonous gases.

Low-power miniaturized radar and a very sensitive navigation system would help the bat find its way at night. Energy scavenging from solar, wind, vibration and other sources would recharge the bat’s lithium battery. The aircraft would use radio to send signals back to troops.

“These are all concepts, and many of them are the next generation of devices we have already developed. We’re trying to push the edge of our technologies to achieve functionality that was not possible before,” said Kamal Sarabandi, the COM-BAT director and a professor in the U-M Department of Electrical Engineering and Computer Science.

COM-BAT also involves the University of California at Berkeley and the University of New Mexico. It is one of four centers the Army launched as a collaborative effort among industry, academia and the Army Research Laboratory to work toward this vision of a small, robotic aircraft that could sense and communicate. Each of the four centers is charged with developing a different subsystem of the bat, a self-directed sensor inspired by the real thing.
Continue reading

Students Create “Disappearing” Nail Polish

‘Vanishing’ colour gives schoolgirls chance to beat ban on nail varnish

A nail varnish that “vanishes” has been developed by a group of school pupils – offering girls the chance to beat bans on makeup. The nail colour is a vivid red outdoors – but inside it transforms to a much paler shade which can hardly be seen.

The dramatic change is caused by a chemical reaction between the varnish and the ultraviolet light in natural sunlight. The polish was devised by pupils from Albion High School, Salford, who thought the “vanishing” colour may help them beat the school’s ban on nail polish.

They came up with the idea while working on an enterprise project with Paul Haywood and Sam Ingleson from Salford University’s school of art and design.

Not exactly what I would create but it is great to see students using scientific thought to find solutions they desire.

Related: The Chemistry of Hair ColoringEngineering Students Design Innovative Hand DryerStudent designs a baby high chairEngineering Student Contest Winners Design Artificial Limb

Scientific American Frontiers Webcasts

All shows of the PBS TV show, Scientific American Frontiers are available online. The shows feature Alan Alda exploring a wide range of scientific ideas. Specific information for teachers if provided for each show. Shows include:

  • Going Deep – “In 1977, scientists aboard Alvin were exploring the Galapagos Rift in the Pacific Ocean when they made one of the most important discoveries in modern biology. Hydrothermal vents are underwater volcanoes erupting magma-heated, mineral-rich water out of cracks on the seafloor thousands of feet beneath the surface. Despite the enormous pressure and total darkness, the vents were found to support an astonishing array of animal life.”
  • The Dark Side of the Universe – Dark matter, dark energy and the universe.
  • Natural Born Robots – “The next generation of robots swim like fish, play soccer and even experience emotions.”
  • Science and Sports – “Science enables people to run quicker, climb higher, hit farther, and sail faster in this sports special.”

Related: BBC In Our Time Science Podcast ArchiveCurious Cat Science Webcast DirectoryOnline Science Resources for TeachersUC-Berkeley Course Videos OnlineScienceLive video archive from Cambridge University

Giant Star Fish and More in Antarctica

photo of giant starfish

Photo by John Mitchell, New Zealand’s National Institute of Water and Atmospheric Research. Read a great deal about the New Zealand Census of Antarctic Marine Life project: 26 scientists and 18 crew took a 50-day voyage aboard RV Tangaroa in February-March 2008.

Benthic invertebrates in Antarctica are well known for their large size. This feature, known as “gigantism” is common amongst certain groups including sea spiders, sponges, isopods, starfish, and amphipods. The phenomenon is a subject of intense scientific investigation, but there are many contributing factors.

Slow growth rates, late reproductive maturation, prolonged periods of embryonic development, and low predation rates that are typical of Antarctic waters contribute to long life-spans for many species and can also result in large size animals. Animal physiology is thought to play a role as well, as those groups that require large amounts of calcium should not, in theory, grow well in Antarctic waters. This is because the calcium carbonate (needed for growth of shells, or starfish ‘tests’) has low solubility in very cold seawater. Yet starfish, which have a calcareous exoskeleton or ‘test’ which needs lots of calcium, can reach much larger sizes than found in New Zealand waters, as seen in [photo].

Another crucial part of the story is that the low sea temperatures allow more oxygen to be dissolved in the sea water than in warmer latitudes. Sea spiders for example are not only larger, but reach more than 1000 times the weight of most temperate species. Amphipod crustaceans in the Southern Ocean are also large; more than five times as long as the largest temperate species.

Related: Ocean LifeArctic SharksAntarctic Fish “Hibernate” in WinterLake Under 2 Miles of Ice