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.

Why is the Sky Blue?

Here is a a nice post explaining why we see blue when we look at the sky, Why Is The Sky Blue?:

Most of the atmospheric gases are transparent to visible light. They don’t filter the Sun’s light and make it yellow, as a yellow filter would. Besides, if colored gases made the Sun appear yellow, where does the blue come from? The part of the atmosphere that changes the Sun’s light is the molecules and tiny particles that are floating in it.

There are particles of water–tiny droplets too small to be seen as clouds. There are particles of organic material–smog or haze, condensed from volatile organic chemicals that have gotten into the air. There are particles of sulfuric acid from volcanoes and power plants. There are molecules of gases in the atmosphere.

These tiny particles, much smaller than the wavelengths of sunlight, scatter the sunlight as photons from the Sun interact with the particles. This is called Rayleigh scattering after the British physicist who described how it works. (Larger particles, like the water droplets in clouds, are closer to the wavelengths of sunlight, and they scatter it differently. This is why clouds are not blue.)

Science explained – quick overviews of scientific concepts: How Does That Happen? Science Provides the Answer – Incredible Insects – 10 Science Facts You Should Know – What Everyone Should Learn – Science Summary: Photosynthesis – String Theory in 1 page – How do antibiotics kill bacteria?

Evidence of Short DNA Segment Self Assembly

Tiny DNA Molecules Show Liquid Crystal Phases, Pointing Up New Scenario For First Life On Earth, University of Colorado:

CU-Boulder physics Professor Noel Clark said the team found that surprisingly short segments of DNA, life’s molecular carrier of genetic information, could assemble into several distinct liquid crystal phases that “self-orient” parallel to one another and stack into columns when placed in a water solution. Life is widely believed to have emerged as segments of DNA- or RNA-like molecules in a prebiotic “soup” solution of ancient organic molecules.
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Such DNA polynucleotides had previously been shown to organize into liquid crystal phases in which the chains spontaneously oriented parallel to each other, he said. Researchers understand the liquid crystal organization to be a result of DNA’s elongated molecular shape, making parallel alignment easier, much like spaghetti thrown in a box and shaken would be prone to line up in parallel, Clark said.

The CU-Boulder and University of Milan team began a series of experiments to see how short the DNA segments could be and still show liquid crystal ordering, said Clark. The team found that even a DNA segment as short as six bases, when paired with a complementary segment that together measured just two nanometers long and two nanometers in diameter, could still assemble itself into the liquid crystal phases, in spite of having almost no elongation in shape.

Structural analysis of the liquid crystal phases showed that they appeared because such short DNA duplex pairs were able to stick together “end-to-end,” forming rod-shaped aggregates that could then behave like much longer segments of DNA. The sticking was a result of small, oily patches found on the ends of the short DNA segments that help them adhere to each other in a reversible way — much like magnetic buttons — as they expelled water in between them, Clark said.
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“In essence, the liquid crystal phase condensation selects the appropriate molecular components, and with the right chemistry would evolve larger molecules tuned to stabilize the liquid crystal phase. If this is correct, the linear polymer shape of DNA itself is a vestige of formation by liquid crystal order.”

Engineering Education Study Debate

Engineering education study draws industry fire by George Leopold, EE Times:

In a radio debate with Salzman on the NPR program “Science Friday,” Intel Corp. Chairman Craig Barrett blasted Salzman’s “backward-looking analysis.” Said Barrett: “The U.S. cannot be successful if we are only ‘average’ ” in math and science. “[S]aying we’re ‘OK’ because we’re average just can’t be right. That’s backward looking. That’s not looking ahead at competition with India, China, Russia and others that are putting heavy emphasis on education.”
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Salzman did, however, conceded one point to his critics, acknowledging that the engineering field in the U.S. isn’t what it used to be. As a profession, “engineering is not a field that has a bright future,” he said. Quoting an engineer interviewed for the Urban Institute study, Salzman said, “It was a great ride, but it’s over.”

Previous posts on the study (The Importance of Science Education – Math and Science Education Assessment). I doubt the engineering ride is over – but everyone is entitled to their opinion. As I have said many times the economic future will be greatly influenced by science and engineering. Those countries that succeed in creating a positive economic climate for science and engineering development will find economic rewards those that fail to do so will suffer. The USA has come through a period where they received great economic benefit from science and engineering supremacy. There is little doubt other centers of excellence will emerge and gain the benefits. But if the USA were to actually fall backward (not just see the relative position decline as other countries gained ground) that will be a serious problem and one I think is unlikely.

New Triceratops Ancestor

Alberta palaeontologists discover new dino genus

Scientists from the Royal Tyrrell Museum and the Canadian Museum of Nature have [discovered]… Eotriceratops xerinsularis (pronounced EE-OH-try-sair-ah-tops ZEER-in-soo-lair-iss)… The dino may be an ancestor of the well-know triceratops, and at the very least, is the group’s earliest known member; researchers say the Eotriceratops lived in southern Alberta 68 million years ago.

It is the largest type of horned dinosaur ever discovered in Alberta, and possibly the world.

According to researchers, Eotriceratops likely reached eight or nine metres from nose to tail. It had a massive skull that featured a solid frill (this alone was three metres in length), and three horns – two above each eye, and another, shorter one, perched on its nose.
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Judging by its teeth, the Eotriceratops was a plant-eater, but one that would have been able to ward off predators.

Who Should Profit from Yellowstone’s Microbes

The Gold in Yellowstone’s Microbes

Year by year, Yellowstone’s hot waters are yielding remarkable new microbial specimens with implications for medicine, agriculture and energy, as well as offering clues to the formation of earliest life on Earth and maybe even on Mars. The potential financial windfalls are enormous, as evidenced by one big jackpot.
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Yellowstone microbes (and those from a few other hot spots on the planet) may also hold great promise for bioremediation — cleaning up chemical pollution, oil slicks and smokestack emissions — as well as the means to accelerate biomass fermentation and develop drought-resistant crops. And there is more to be discovered: Probably less than one percent of Yellowstone’s microscopic life forms have been discovered and studied.
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the National Park Service signed a secretive research-sharing agreement with Diversa Corporation in 1998. Non-profit groups quickly cried “bio-piracy!” when they found out and sued the Service over the arrangement. While a federal court dismissed the case, it ordered the Park Service to address the issue… But the Park Service is still trying to come up with an acceptable, benefits-sharing agreement that might allow bio-prospecting of microbes and disclosure of findings, with a fair return to the Park from any commercial success.

Six Cool Ideas

Six Ideas That Will Change the World

The Pollution Magnet – Eighty-two thousand people die from cancer in Bangladesh every year, many due to arsenic poisoning. But building upon her discovery of a way to get rust nanoparticles to bind to arsenic, Vicki Colvin has invented a new, astonishingly easy way to clean the water supply: SautÃ© a teaspoon of rust in a mixture of oil and lye, which breaks down the rust into nano-sized pieces. Retrieve the rust particles with a household magnet. Then immerse the rust-covered magnet into a pot of contaminated water. Pull out the arsenic. The system is up to a hundred times more efficient than existing methods, and requires no electricity or manufacturing infrastructure, so even the poorest of villagers can use it.

Depending upon government regulations, Colvin’s extraction system should go global in as few as five years. Yet ultimately, Colvin, a professor of chemistry and chemical and biomolecular engineering at Rice University, has bigger plans. She sees her method as just the first step toward developing an easy point-of-use water-purification system that would cover virtually every pollutant. The filter would have a dipstick to tell you what’s in the water and a reader to tell you what you need to add to pull it out — perhaps silver nanoparticles to kill bacteria or a protein to capture pesticides.

Moringa Oleifera: The Miracle Tree

One thing I enjoy brought about by the web is finding interesting tidbits such as – Moringa Oleifera: The Miracle Tree:

For centuries, the natives of northern India and many parts of Africa have known of the many benefits of Moringa oleifera. Its uses are as unique as the names it is known by, such as clarifier tree, horseradish tree and drumstick tree (referring to the large drumstick shaped pods) and in East Africa it is called “mother’s best friend”. Virtually every part of the tree can be used. Native only to the foothills of the Himalayas, it is now widely cultivated in Africa, Central and South America, Sri Lanka, India, Malaysia and the Philippines. This tree, though little known in the Western world, is nutritional dynamite. There are literally hundreds of uses for this tree.

The immature pods are the most valued and widely used of all the tree parts. The pods are extremely nutritious, containing all the essential amino acids along with many vitamins and other nutrients. The immature pod can be eaten raw or prepared like green peas or green beans, while the mature pods are usually fried and possess a peanut-like flavor. The pods also yield 38 – 40% of non-drying, edible oil known as Ben Oil. This oil is clear, sweet and odorless, and never becomes rancid. Overall, its nutritional value most closely resembles olive oil. The thickened root is used as a substitute for horseradish although this is now discouraged as it contains alkaloids, especially moriginine, and a bacteriocide, spirochin, both of which can prove fatal following ingestion. The leaves are eaten as greens, in salads, in vegetable curries, as pickles and for seasoning. They can be pounded up and used for scrubbing utensils and for cleaning walls. Leaves and young branches are relished by livestock. The Bark can be used for tanning and also yields a coarse fiber. The flowers, which must be cooked, are eaten either mixed with other foods or fried in batter and have been shown to be rich in potassium and calcium.

More internet finds: Sarah, aged 3, Learns About Soap – Plumpynut, Miracle Food – The Avocado – More Nutritious Wheat – Cool Mechanical Simulation System – Aerogels – Weird Solids – Awesome Cat Cam

Nigersaurus

photo of the Nigersaurus Jaw Bones

Structural Extremes in a Cretaceous Dinosaur

Nigersaurus taqueti shows extreme adaptations for a dinosaurian herbivore including a skull of extremely light construction, tooth batteries located at the distal end of the jaws, tooth replacement as fast as one per month, an expanded muzzle that faces directly toward the ground, and hollow presacral vertebral centra with more air sac space than bone by volume. A cranial endocast provides the first reasonably complete view of a sauropod brain including its small olfactory bulbs and cerebrum. Skeletal and dental evidence suggests that Nigersaurus was a ground-level herbivore that gathered and sliced relatively soft vegetation, the culmination of a low-browsing feeding strategy first established among diplodocoids during the Jurassic.

This discovery has received a good deal of coverage. Among other things it is great to see this paper is available to everyone who wants to view it because it is published by open access PLoS One. The Nigersaurus was discovered in what is now the Sahara Desert in Niger. When the Nigersaurus was roaming the area, 110 million years ago, the climate was a Mesozoic forest. The dinosaur had a few hundred teeth that were replaced almost monthly (a record). The bones of the head and neck were so minimal and light that the Read more about the Nigersaurus. As the author stated: “One of the stunning things about this animal is how fragile the skull is… Some of the bones are so thin you can shine a light through them.”

2nd Annual Science Blogging Conference

2nd Annual Science Blogging Conference will be held in North Carolina on January 19th (there are also pre-conference activities on the 18th). I unfortunately won’t make it but take a look and see if it is something you would enjoy. The program includes:

Open Science: how the Web is changing the way science is done, written and published with Dr.Hemai Parthasarathy
Blogging about the Social Sciences and Humanities with Martin Rundkvist and John McKay
Changing Minds through Science Communication: a panel on Framing Science with Chris Mooney , Jennifer Jacquet and Sheril Kirshenbaum

Open Laboratory 2007, an anthology of science blog posts will be published, as it was last year. Posts need to have been posted between 20 Dec 2006 and 20 Dec 2007 to be eligible. Submit your suggestions.

Gene Carnival

From Scienceroll’s carnival post – Gene Genie #19: Geneticalization

Matt Mealiffe at DNA and You talks about several genes linked to eye color.

Larry Moran, our favourite professor and author of Sandwalk, has a post about diversity and the major histocompatibility (MHC) loci.

PZ Myers at Pharyngula says mutations in the CFTR gene cause Cystic Fibrosis.

T. Ryan Gregory at Genomicron asks a strange question: Are you a cat genome person or a dog genome person?