Category Archives: Science

Schoolgirls Find Vitamin C is Missing

Schoolgirls rumble Ribena vitamin claims:

“We thought we were doing it wrong. We thought we must have made a mistake,” Anna told New Zealand’s Weekend Herald. The girls were both 14 and students at Pakuranga College in Auckland when they did the experiment in 2004. Given Ribena’s advertising claims that “the blackcurrants in Ribena have four times the vitamin C of oranges”, they were astonished and wrote to the manufacturers, GlaxoSmithKline (GSK). When they got no response, they phoned the company, but were given short shrift. “They didn’t even really answer our questions. They just said it’s the blackcurrants that have it, then they hung up,” Jenny said.

But then the girls’ claims were picked up by a TV consumer affairs programme, Fair Go, which suggested they take their findings to the commerce commission, a government watchdog. GSK said the girls had tested the wrong product, and it was concentrated syrup which had four times the vitamin C of oranges. But when the commerce commission investigated, it found that although blackcurrants have more vitamin C than oranges, the same was not true of Ribena. It also said ready-to-drink Ribena contained no detectable level of vitamin C.

GSK is in court in Auckland today facing 15 charges relating to misleading advertising, risking fines of up to NZ$3m (Â£1.1m). In Australia, GSK has admitted that its claims about Ribena may have misled consumers.

Virus Traps

Scientists Explore Ways to Lure Viruses to Their Death by Carl Zimmer:

Viruses invade a cell by latching onto certain proteins on its surface. Once attached, they can slip inside the cell and manipulate it into making new copies of themselves. But viruses cannot infect red blood cells. Unlike most other cells in the body, as red blood cells develop in bone marrow they lose their DNA. If a virus ends up inside a red blood cell, there are no genes it can hijack to replicate itself.

“It occurred to us that if a virus bound to a red blood cell, that was a dead end,” said Dr. Robert W. Finberg, a professor at the University of Massachusetts Medical School.
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To test the model, the scientists mixed normal bacteria with different levels of mutant traps and then infected them with viruses. After letting the viruses replicate, the scientists took a small sample to start a new colony. They discovered there was indeed a trap threshold above which the virus population could not survive. Above that threshold, the viruses disappeared by the time the scientists started the third round of colonies.

Open Access Science Education Journal

Science in School is an open access journal focused on science education published quarterly.

Science in School aims to promote inspiring science teaching by encouraging communication between teachers, scientists, science teachers and everyone else involved in European science education. Science in School addresses science teaching both across Europe and across disciplines: highlighting the best in teaching and cutting-edge research. It covers not only biology, physics and chemistry, but also maths, earth sciences, engineering and medicine, focusing on interdisciplinary work.

The contents include teaching materials; cutting-edge science; education projects; interviews with young scientists and inspiring teachers; European education news; reviews of books and other resources; and European events for teachers.

The latest issue includes: Silky, stretchy and stronger than steel by Giovanna Cicognani and Montserrat Capellas (on spider silk), A fresh look at light: build your own spectrometer by Mark Tiele Westra, Fair enough? Balanced considerations for future science-fair organisers by Eva Amsen and Fusion in the Universe: we are all stardust by Henri Boffin and Douglas Pierce-Price.

Biologists Solve B-12 Vitamin Puzzle

MIT biologists solve vitamin puzzle

B12, the most chemically complex of all vitamins, is essential for human health. Four Nobel Prizes have been awarded for research related to B12, but one fragment of the molecule remained an enigma–until now. The researchers report that a single enzyme synthesizes the fragment, and they outline a novel reaction mechanism that requires cannibalization of another vitamin.
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Vitamin B12 is produced by soil microbes that live in symbiotic relationships with plant roots.
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BluB catalyzes the formation of the B12 fragment known as DMB, which joins with another fragment, produced by a separate pathway, to form the vitamin. One of several possible reasons why it took so long to identify BluB is that some bacteria lacking the enzyme can form DMB through an alternate pathway, Walker said.

One of the most unusual aspects of BluB-catalyzed synthesis is its cannibalization of a cofactor derived from another vitamin, B2. During the reaction, the B2 cofactor is split into more than two fragments, one of which becomes DMB. Normally, the B2-derived cofactor would assist in a reaction by temporarily holding electrons and then giving them away. Such cofactors are not consumed in the reaction.

Relationships Among Scientific Paradigms

Links (curved black lines) were made between the paradigms that shared papers, then treated as rubber bands, holding similar paradigms nearer one another when a physical simulation forced every paradigm to repel every other; thus the layout derives directly from the data. Larger paradigms have more papers; node proximity and darker links indicate how many papers are shared between two paradigms. Flowing labels list common words unique to each paradigm, large labels general areas of scientific inquiry.

See the site for a interesting graphic display of the relationships.

Researchers Learn What Sparks Plant Growth

Researchers Learn What Sparks Plant Growth:

“How do organisms decide when to grow and when to stop growing? These questions are especially important in plants because they are rooted in the ground and must alter their shape and size in response to their local environment. Thus, it’s a question of survival,” added Chory. “It took us 10 years to develop the tools to ask the question. It is very satisfying for me to see the results.”
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“It’s been a matter of some debate for a very long time if one of these tissue layers controls plant growth or if all three layers have to work together,” Chory said. “Our paper shows very clearly that the epidermis is in control—in both driving and restricting growth. In addition, our studies show that the cells in the epidermis “talk” to the cells in the inner layers, communicating that they too should expand.”

In January we had a long stretch of warm weather. Shoots for early blooming flowers sprouted in my front yard. Then we had about 6 weeks of winter weather. I was wondering how the flowers would do (they do fine with a few days of freezing weather after sprouting – since they have evolved to bloom early). They did fine, photo above (by John Hunter, March 11th).

Immense Amount of Ice Found on Mars

Dense Ice Revealed at Mars’ South Pole

Radar scans of Mars have unveiled a vast reservoir of nearly pure frozen water around the planet’s south pole, a deposit so rich that if it were spread evenly on the surface it would be 36 feet deep.
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For now, it’s one of the many question marks that dot Mars research initiatives. Scientists still can’t explain what happened to all the water that must have been needed to carve Mars’ surface features.

Magnificent Flying Machine

A magnificent flying machine

The next time you attempt to swat a fly, remember that you are trying to destroy a flying machine that engenders awe and bafflement in scientists, engineers and professors of aerodynamics. Thanks to remarkable flying skills that make the housefly the Ferrari of the insect world, it is unlikely you will achieve a direct hit. While fleeing a rolled-up newspaper, the insect can change course in as little as 30 thousandths of a second.

This and other flying insects have plagued the worlds of science and engineering ever since the first calculation of bumble-bee flight was attempted at GÃ¶ttingen University in the 1930s. Conventional aerodynamics suggested the insect should not generate enough lift to fly. The sums caused consternation.

In the past few years, however, remarkable advances have been made. The so-called “bumble-bee paradox” was solved by Dr Charles Ellington and colleagues from Cambridge University when, with the help of a robot insect, they highlighted the bee’s secret: extra lift is generated during a downstroke by a spiral vortex that travels along the leading edge of each wing, from base to tip.

Particles and Waves

Science team shows light is made of particles and waves:

Work completed by a visiting research professor at Rowan University, physics professors and a student from the institution shows that light is made of particles and waves, a finding that refutes a common belief held for about 80 years.

Shahriar S. Afshar, the visiting professor who is currently at Boston’s Institute for Radiation-Induced Mass Studies (IRIMS), led a team, including Rowan physics professors Drs. Eduardo Flores and Ernst Knoesel and student Keith McDonald, that proved Afshar’s original claims, which were based on a series of experiments he had conducted several years ago.

An article on the work titled “Paradox in Wave-Particle Duality” recently published in “Foundations of Physics,” a prestigious, refereed academic journal, supports Albert Einstein’s long-debated belief that quantum physics is incomplete. For eight decades the scientific community generally had supported Niels Bohr’s ideas commonly known as the Copenhagen Interpretation of Quantum Mechanics.
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“The important new contribution is that light carries both wave and particle aspects at all times, and future experiments will further clarify the nature of each component.” Afshar said.

Attacking Bacterial Walls

Bacterial Walls Come Tumbling Down:

Penicillin and many newer antibiotics work by blocking a piece of the machinery bacteria use to construct their durable outer walls. Without these tough, protective coatings, bacteria die. The enzymatic machinery (known as PBP2) studied by Strynadka’s group has two main parts: One end assembles long sugar fibers; the other end stitches them together with bits of protein to form a sturdy interlocking mesh shell.
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“This enzyme is an awesome target for antibiotics,” said Strynadka. “We have a totally new understanding of how the enzyme works and how a very good animal antibiotic inhibits the enzyme.” Although moenomycin is poorly absorbed by the human body, the new understanding of exactly how it interferes with bacterial enzyme function should help scientists design modified versions that are more suitable for use in people.

Understanding the structure of this enzyme should also speed up screening and design of new antibiotics, which are in constant demand as microbes continually evolve new ways to evade the drugs that researchers design to thwart them. The time it takes for bacteria to develop resistance to new antibiotics has been as short as one year for penicillin V and as long as 30 years for vancomycin.