Category Archives: Students

Items for students and others, interested in learning about science and engineering and the application of science in our lives. We post many of the general interest items here.

Still Just a Lizard

Still just a lizard by PZ Myers

in 1971, scientists started an experiment. They took 5 male lizards and 5 female lizards of the species Podarcis sicula from a tiny Adriatic island called Pod Kopiste, 0.09km2, and they placed them on an even tinier island, Pod Mrcaru, 0.03km2, which was also inhabited by another lizard species, Podarcis melisellensis. Then a war broke out, the Croatian War of Independence, which went on and on and meant the little islands were completely neglected for 36 years, and nature took its course. When scientists finally returned to the island and looked around, they discovered that something very interesting had happened.

The original population of P. sicula was still present on Pod Kopiste, so we have a nice control population. These lizards are small, fast, insect-eaters in which the males defend territories. Sadly, P. melisellensis on Pod Mrcaru had been extirpated. So we had a few innocent casualties of the experiment.

The transplanted P. sicula thrived and swarmed over the island of Pod Mrcaru, but they were different, and they had evolved in multiple ways.

The original P. sicula were insectivores who occasionally munched on a leaf; approximately 4-7% of their diet was vegetation. The P. sicula of Pod Mrcaru, though, had adopted a more vegetarian diet: examining their gut contents revealed that 34% of their diet was plants in the spring, climbing to 61% in the summer…and much of this diet was hard-to-digest stuff, high in cellulose. This is a fairly radical shift.

There were concomitant changes. The lizards’ skulls were wider, deeper, and longer, and they had stronger bites — a necessity for chomping off bits of tough plants, instead of soft mosquitos. Instead of chasing bugs, they’re browsing stationary plants, and their legs are shorter and they are slower. Population densities are higher. The Pod Mrcaru lizards no longer seem to defend territories, so there have been behavioral changes.

Still just a lizard, I know.

Now here’s something really cool, though: these lizards have evolved cecal valves. What those are are muscular ridges in the gut that allow the animal to close off sections of the tube to slow the progress of food through them, and to act as fermentation chambers where plant material can be broken down by commensal organisms like bacteria and nematodes — and the guts of Pod Mrcaru P. sicula are swarming with nematodes not found in the guts of their Pod Kopiste cousins.

Engaging the YouTube Generation in Hands-on Science

Cherlyn Anderson is one of eight Einstein Fellows spending this academic year at NSF. In her other life, Anderson is an eighth-grade science teacher in South Carolina. She has used an experiment involving Mentos candy and Diet Coke as a teaching tool. The accompanying video offers a demonstration of the experiment, and discusses its benefits for eighth-grade science students.

Follow the link for a webcast. Somewhat ironically the NSF headline mentions YouTube but fails to take advantage of one of the things that has made YouTube (and others sharing videos: TED…) so successful. The ability to embed the videos on web sites, blog posts… The technical quality of the video is very nice (more pixels than YouTube videos).

Materials Engineers Create Perfect Light “sponge”

Materials engineers create perfect light “sponge”

The team designed and engineered a metamaterial that uses tiny geometric surface features to successfully capture the electric and magnetic properties of a microwave to the point of total absorption.

“Three things can happen to light when it hits a material,” says Boston College Physicist Willie J. Padilla. “It can be reflected, as in a mirror. It can be transmitted, as with window glass. Or it can be absorbed and turned into heat. This metamaterial has been engineered to ensure that all light is neither reflected nor transmitted, but is turned completely into heat and absorbed. It shows we can design a metamaterial so that at a specific frequency it can absorb all of the photons that fall onto its surface.”
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The metamaterial is the first to demonstrate perfect absorption and unlike conventional absorbers it is constructed solely out of metallic elements, giving the material greater flexibility for applications related to the collection and detection of light, such as imaging, says Padilla, an assistant professor of physics.

Nobel Laureate Initiates Symposia for Student Scientists

The video shows a portion of Oliver Smithies’ Nobel acceptance lecture. See the rest of the speech, and more info, on the Nobel Prize site.

As an undergraduate student at Oxford University in the 1940s, Oliver Smithies attended a series of lectures by Linus Pauling, one of the most influential chemists of the 20th century. It was a powerful experience, one that sparked the young scientist’s ambitions and helped launch his own eminent career.

“It was tremendously inspiring,” says Smithies, one of three scientists who shared the Nobel Prize in Medicine in 2007. “People were sitting in the aisles to listen to him.”

Now Smithies, who was a genetics professor at the University of Wisconsin-Madison from 1960-88, is taking it upon himself to expose a new generation of undergraduates to this sort of experience. Using the prize money that came with his Nobel Prize, Smithies is funding symposia at all four universities he has been affiliated with throughout his scientific career: Oxford, the University of Toronto, UW-Madison and the University of North Carolina, where he is currently the Excellence Professor of Pathology and Laboratory Medicine. Each university will receive about $130,000 to get things started.

“He wants the symposium to be a day when we bring the very best in biology to campus to interact with the students,” says geneticist Fred Blattner, who is in charge of organizing the symposium at UW-Madison and who collaborated with Smithies when their careers paths overlapped in Wisconsin.

The first of two speakers at the UW-Madison’s inaugural Oliver Smithies Symposium will be Leroy Hood, director of the Institute for Systems Biology, located in Seattle. Hood is a pioneer of high-throughput technologies and was instrumental in developing the technology used to sequence the human genome. More recently, Hood has focused his efforts on systems biology, the field of science in which researchers create computer models to describe complex biological processes, such as the development of cancer in the body. He is also at the forefront of efforts to use computer models to help doctors tailor drugs and dosages to an individual’s genetic makeup.
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Robotic Prosthetic Arms for People

Dean Kamen latest invention was funded by DARPA. Once again he is doing amazing stuff. It is great what engineers can do (many worked together to get the progress so far) when given the opportunity. We need many more such efforts.

Dean Kamen Lends a Hand, or Two (August 2007):

DARPA has spent almost $25 million funding two independent teams, Mr. Kamen’s DEKA Research & Development Corp. and a group at Johns Hopkins’ University in an effort they hope will ultimately lead to commercial prosthesis that can be controlled from the human brain.

The innovation in the DEKA arm lies in its ultra light weight carbon shell, giving the user an exoskeleton with which to gain the leverage necessary to do some of the extraordinary things the system makes possible, such as lifting a 40 lb. weight.

To make the system function, the DEKA engineers coated the inside of the shell with a mosaic of thin air bladders that can be individually filled with air to offer padding and rigidity necessary to make possible normally ordinary tasks such as operating a portable power drill. When the arm is not in use the system deflates, or can even alternately fill and empty to offer a massage effect, so that it is not painful to wear for long periods.

The DEKA system is controlled by a joystick that is moved by the remaining portion of the user’s arm and by a second control mechanism in the user’s shoe. Mr. Kamen said that despite the complexity of controlling an ensemble of motors and mechanical servo devices, a user can gain basic functional control in just one day.

International Engineering Education Data: USA, China, India

Several years ago we posted about the report on the USA Under-counting Engineering Graduates. The authors, and two others, have written a new report that provides some useful additions – Getting the Numbers Right: International Engineering Education in the United States, China, and India

Since the late 1990s, the United States had a modest increase in bachelor’s degree output, from just over 103,000 in 1998–99 to more than 137,000 in 2003–04 before declining slightly to about 129,000 in 2005–06, a growth of nearly 25 percent since 1998–99. India’s expansion at the bachelor’s level was more rapid, with four-year degree holders in engineering, CS, and IT more than tripling in the last seven years, from just over 68,000 in 1998–99 to nearly 220,000 in 2005–06. The fastest growth in bachelor’s degrees, however, appears to be occurring in China. According to the Chinese MoE, the number of bachelor’s degrees awarded has more than doubled in the last four years, from 252,000 in 2001–02 to 575,000 in 2005–06.
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While engineering, CS, and IT degree production in the United States has been stable or increasing at all degree levels over the past ten years, a sizable percentage of these degrees are indeed being
awarded to foreign nationals. Statistics collected by the ASEE on bachelor’s, master’s and Ph.D. degrees in engineering indicate that during the 2005–06 academic year, 7.2 percent, 39.8 percent and 61.7 percent of these degrees, respectively, were awarded to foreign nationals (Figure 4). As these figures indicate, the percentage of foreign nationals is significantly higher at the graduate level, especially for Ph.D. degrees.

Put a Little Science in Your Life

Put a Little Science in Your Life By Brian Greene

And when we look at the wealth of opportunities hovering on the horizon — stem cells, genomic sequencing, personalized medicine, longevity research, nanoscience, brain-machine interface, quantum computers, space technology — we realize how crucial it is to cultivate a general public that can engage with scientific issues; there’s simply no other way that as a society we will be prepared to make informed decisions on a range of issues that will shape the future.

These are the standard – and enormously important – reasons many would give in explaining why science matters.

But here’s the thing. The reason science really matters runs deeper still. Science is a way of life. Science is a perspective. Science is the process that takes us from confusion to understanding in a manner that’s precise, predictive and reliable – a transformation, for those lucky enough to experience it, that is empowering and emotional. To be able to think through and grasp explanations – for everything from why the sky is blue to how life formed on earth – not because they are declared dogma but rather because they reveal patterns confirmed by experiment and observation, is one of the most precious of human experiences.

Excellent article by the author of The Elegant Universe.

Mapping the Human Proteome

The human genome is old news. Next stop: the human proteome

Unlike the genome, which remains essentially static between cell types and over time, the proteome is tremendously dynamic, changing constantly in response to cell-cell signalling and environmental stimuli. Thus even though -with some small exceptions – every cell in your body carries the same genome, the proteome can be wildly different between different tissues and can change rapidly over time
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At the very least, large-scale analysis of the human proteome should allow researchers to tentatively place many of our currently anonymous genes into functional pathways. That’s a step forward for personal genomics: knowing that you have a loss-of-function mutation in a gene that may be involved in cholesterol biosynthesis is a lot more useful (in terms of guiding further clinical testing) than simply knowing that you have a mutation in hypothetical gene C11orf68.

Using Cameras Monitoring To Aid Conservation Efforts

photo of Jaguar

How Hidden Cameras Aid Conservation Efforts for Jaguars and Other Rare Animals

Tobler and his fellow authors write that “despite years of research throughout the Amazon, there are few complete mammal inventories and our knowledge of the distributions of rare and elusive species is still poor.” They explain further that traditional techniques for inventorying which animals are present in a given ecosystem, such as identification of tracks and scat, direct observations, and trapping of animals often do not account for species of animals that are rare and/or low in their numbers in a certain area. For these reasons, they wanted to test out how well cameras could document animals in the rainforest, where cover is dense and many species are hard to observe.
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Over the two years of the study, some of the more photographed animals included the Lowland tapir, which was caught on camera 102 times and also the White-lipped Peccary (seen 210 times). Among cat species, jaguars were photographed 51 times, ocelots 46 times, pumas 25 times, margays 15 times, and jaguarundis proved the most elusive, only being photographed twice.

The four species of animals that were not photographed included the pacarana, the grison, the Southern naked-tailed armadillo, and the Bush dog.
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Given the recent lowering of costs and improvements in camera technology, hopefully their example and those of others will help other conservationists around the world to better understand the location of important and rare animals in their respective ecosystems. Given the large range of jaguars and their need for connected habitat, this study gives us hope to think that little hidden cameras might help us better understand where these charismatic cats and other rare animals roam, and consequently give us better information with which to help protect them.

Photo Credit: purplegrum at Flickr under a Creative Commons attribution license

New Iron Based Superconductors

Research Suggests Novel Superconductor Is in a Powerful Class All its Own

discovered surprising magnetic properties in the new superconductors that suggest they may have very powerful applications — from improved MRI machines and research magnets, to a new generation of superconducting electric motors, generators and power transmission lines. The research also adds to the long list of mysteries surrounding superconductivity, providing evidence that the new materials, which scientists are calling “doped rare earth iron oxyarsenides,” develop superconductivity in quite a new way
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Early this year, Japanese scientists who had been developing iron-based superconducting compounds for several years, finally tweaked the recipe just right with a pinch of arsenic. The result: a superconductor, also featuring oxygen and the rare earth element lanthanum, performing at a promising -413 degrees F (26 K). The presence of iron in the material was another scientific stunner: Because it’s ferromagnetic, iron stays magnetized after exposure to a magnetic field, and any current generates such a field. As a rule, magnetism’s effect on superconductivity is not to enhance it, but to kill it.

Iron based superconductors might resist magnetic fields over 100 Tesla

The new superconductors seem like they will be able to make improved MRI machines and research magnets, a new generation of superconducting electric motors, generators and power transmission lines. Tesla is a unit of magnetic field strength; the Earth’s magnetic field is one twenty thousandth of a tesla.