Category Archives: Science

Biologists Solve B-12 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.

Invasive Plants: Tamarisk

To Save the West, Kill a Plant by Josh McDaniel:

The tamarisk, an invasive species introduced to the United States from Eurasia, is a deep-rooted plant that aggressively obtains water from the soil and groundwater. A single mature tree can produce up to 500,000 seeds per year, crowding out native plants along rivers and creeks and reducing wildlife habitat. The species now infests all the major rivers, springs, ditches, and wetlands in ten states—including Texas, Arizona, Utah, Colorado, New Mexico, Nevada, and California—and is rapidly expanding into others.

In the delicately dry ecosystems of the southwestern United States, that is a serious problem, adding up to over 800 billion gallons of lost water per year across the parched region. “That is equal to the water needs of 20 million people or one million acres of irrigated farmland,” said Tim Carlson, an environmental engineer and director of the Tamarisk Coalition, which aims to control the plant.

Living systems include risks for those that attempt to engineer improvement. The past is littered with examples of attempts to intervene that go wrong.

“One night, after I gave a presentation on tamarisk, an older gentleman came up to me and told me that he had earned his Eagle Scout rank by planting tamarisk to prevent soil erosion after the Dust Bowl era in the 1930s,” Carlson recalled. “He said he would gladly earn it again by helping me remove it.”

I don’t think there is a simple answer. We are going to have intentional and unintentional consequences results from our actions. To me the lesson is to learn from our past that we often have unintended consequences that are worse than we envisioned and we need to be careful. We can’t assume there are no risks that we don’t know about. There are risks we can’t predict.

Non-Newtonian Fluid Demo

via: A pool filled with non-newtonian fluid:

They filled a pool with a mix of cornstarch and water made on a concrete mixer truck. It becomes a non-newtonian fluid. When stress is applied to the liquid it exhibits properties of a solid. Video was recorded at Barcelona, Spain. A non-Newtonian fluid is a fluid in which the viscosity changes with the applied strain rate. As a result, non-Newtonian fluids may not have a well-defined viscosity.

USA Science and Engineering Degree Data – 2007

A huge amount of interesting data can be found in NSF’s report on the USA: Women, Minorities, and Persons with Disabilities in Science and Engineering (pdf)

Since 2000 women have received more science and engineering bachelors degrees than men. Men still receive more master’s and doctoral degrees in science and engineering.

2004 bachelor’s degrees	Female	Male
Engineering	13,257	51,418
Computer Science	14,406	42,999
Psychology	64,208	18,302
Science and engineering	227,813	224,525
Total non-S&E	583,004	371,667

200,000 more for bachelor’s degrees for women – wow. This is just a continuation of a trend but still is fairly amazing.

2004 Master’s degrees for US citizens	Female	Male
Engineering	7,135	26,737
Computer Science	6,195	13,658
Psychology	11,950	3,348
Science and engineering	51,420	66,631
Total non-S&E	276,782	160,704

2004 Doctoral degrees for US citizens	Female	Male
Engineering	1,014	4,353
Computer Science	195	690
Psychology	2,245	1,042
Science and engineering	9,819	15,728

Some more interesting data: 90% of Asian, 60% of Native Hawaiian/other Pacific Islander 40% of Hispanic doctoral S&E faculty were born outside the United States. Over 80 % of white, American Indian/Alaska Native, and multiple race doctoral S&E faculty were born in the United States.