Category Archives: Science

Plants can Signal Microbial Friends for Help

When under attack, plants can signal microbial friends for help

Researchers at the University of Delaware have discovered that when the leaf of a plant is under attack by a pathogen, it can send out an S.O.S. to the roots for help, and the roots will respond by secreting an acid that brings beneficial bacteria to the rescue.

In a series of laboratory experiments, the scientists infected the leaves of the small flowering plant Arabidopsis thaliana with a pathogenic bacterium, Pseudomonas syringae. Within a few days, the leaves of the infected plants began yellowing and showing other symptoms of disease.

However, the infected plants whose roots had been inoculated with the beneficial microbe Bacillus subtilis were perfectly healthy. Farmers often add B. subtilis to the soil to boost plant immunity. It forms a protective biofilm around plant roots and also has antimicrobial properties, according to Bais.

Using molecular biological tools, the scientists detected the transmission of a long-distance signal, a “call for help,” from the leaves to the roots in the plants that had Bacillus in the soil. The roots responded by secreting a carbon-rich chemical–malic acid.

All plants biosynthesize malic acid, Bais explains, but only under specific conditions and for a specific purpose–in this case, the chemical was actively secreted to attract Bacillus. Magnified images of the roots and leaves showed the ratcheted-up defense response provided by the beneficial microorganisms.

“Plants can’t move from where they are, so the only way they can accrue good neighbors is through chemistry,” Bais notes.

Related: Researchers Learn What Sparks Plant GrowthSecret Life of MicrobesSymbiotic relationship between ants and bacteriaBacterium Living with High Level Radiation

Silk E.coli Sensors

“Edible Optics” Could Make Food Safer

Scientists at Tufts University’s School of Engineering have demonstrated for the first time that it is possible to design such “living” optical elements that could enable an entirely new class of sensors. These sensors would combine sophisticated nanoscale optics with biological readout functions, be biocompatible and biodegradable, and be manufactured and stored at room temperatures without use of toxic chemicals. The Tufts team used fibers from silkworms to develop the platform devices.

The possibility of integrating optical readout and biological function in a single biocompatible device unconstrained by these limitations is tantalizing. Silk optics has captured the interest of the Defense Department, which has funded and been instrumental in enabling rapid progress on the topic. The Defense Advanced Research Projects Agency (DARPA) awarded Tufts a research contract in 2007 and is funding Tufts and others on groundbreaking projects that could someday result in biodegradable optical sensing communications technology.

To form the devices, Tufts scientists boiled cocoons of the Bombyx mori silkworm in a water solution and extracted the glue-like sericin proteins. The purified silk protein solution was ultimately poured onto negative molds of ruled and holographic diffraction gratings with spacing as fine as 3600 grooves/mm.

The Tufts team embedded three very different biological agents in the silk solution: a protein (hemoglobin), an enzyme (horseradish peroxidase) and an organic pH indicator (phenol red). In the hardened silk optical element, all three agents maintained their activity for long periods when simply stored on a shelf. “We have optical devices embedded with enzymes that are still active after almost a year of storage at room temperature.

Related: E. Coli IndividualityScience Fair Project on Bacterial Growth on Packaged SaladsProtecting the Food Supplyposts on food

The Rush to Save Timbuktu’s Crumbling Manuscripts

The Rush to Save Timbuktu’s Crumbling Manuscripts

Fabled Timbuktu, once the site of the world’s southernmost Islamic university, harbors thousands upon thousands of long-forgotten manuscripts. A dozen academic instutions from around the world are now working frantically to save and evaluate the crumbling documents.

The Ahmed Baba Library alone contains more than 20,000 manuscripts, including works on herbal medicine and mathematics, yellowed volumes of poetry, music and Islamic law. Some are adorned with gilded letters, while others are written in the language of the Tuareg tribes. The contents remain a mystery.

Manuscript hunters are now scouring the environs of Timbuktu, descending into dark, clay basements and climbing up into attics. Twenty-four family-owned collections have already been discovered in the area. Most of the works stem from the late Middle Ages, when Timbuktu was an important crossroads for caravans.

Archaeologists have shown that an incredible system of underground canals up to 20,000 kilometers (12,422 miles) long once existed at Wadi al-Hayat in Libya. Thanks to such hydraulic marvels, the desert blossomed and crops sprouted in the fields of the Tuareg.

Related: digital library of scholarly resources from and about AfricaAfrican Union Science Meeting

Science Postercasts

I wrote about SciVee, over a year ago, saying I thought they could become a valuable resource. It has been taking longer to really get going than I thought it would but this new feature, Postercasts, is great. I am glad to see SciVee living up to my high expectation. Keep up the great work SciVee. The experience can still use improvement but this is a great start.

They have provided a tutorial on: How to Synchronize my Poster to my Video. I hope some of our readers try this out.

via: Interactive Virtual Posters

Related: Engineering TVScience WebcastsMagnetic Movie

2007 National Medals of Science and Technology

photo of 2007 Medals of Science Presentation at the White House

2007 National Medal of and Technology and Innovation

Paul Baran for the invention and development of the fundamental architecture for packet-switched communication networks, which provided a paradigm shift from the circuit-switched communication networks of the past, and later was used to build the ARPANET and the Internet.

Armand V. Feigenbaum for his leadership in the development of the economic relationship of quality costs, productivity improvement, and profitability, and for his pioneering application of economics, general systems theory and technology, statistical methods, and management principles that define The Total Quality Management approach for achieving performance excellence and global competitiveness. See the Curious Cat Management Improvement portal.

Adam Heller for his fundamental contributions to electrochemistry and bioelectric chemistry, and the subsequent application of those fundamentals in the development of technological products that improved the quality of life across the globe, most notably in the area of human health and well-being.

Carlton Grant Willson for the creation of novel lithographic imaging materials and techniques that have enabled the manufacturing of smaller, faster, and more efficient microelectronic components that have improved the competitiveness of U.S. microelectronics industry.
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The Nobel Prize in Chemistry 2008

The Nobel Prize in Chemistry 2008 is evenly shared by Osamu Shimomura, Boston University Medical School, USA; Martin Chalfie, Columbia University, New York, USA and Roger Y. Tsien, University of California, San Diego, USA for discovery and work with glowing green fluorescent protein.

The remarkable brightly glowing green fluorescent protein, GFP, was first observed in the beautiful jellyfish, Aequorea victoria in 1962. Since then, this protein has become one of the most important tools used in contemporary bioscience. With the aid of GFP, researchers have developed ways to watch processes that were previously invisible, such as the development of nerve cells in the brain or how cancer cells spread.

Tens of thousands of different proteins reside in a living organism, controlling important chemical processes in minute detail. If this protein machinery malfunctions, illness and disease often follow. That is why it has been imperative for bioscience to map the role of different proteins in the body.

This year’s Nobel Prize in Chemistry rewards the initial discovery of GFP and a series of important developments which have led to its use as a tagging tool in bioscience. By using DNA technology, researchers can now connect GFP to other interesting, but otherwise invisible, proteins. This glowing marker allows them to watch the movements, positions and interactions of the tagged proteins.

Researchers can also follow the fate of various cells with the help of GFP: nerve cell damage during Alzheimer’s disease or how insulin-producing beta cells are created in the pancreas of a growing embryo. In one spectacular experiment, researchers succeeded in tagging different nerve cells in the brain of a mouse with a kaleidoscope of colors.


Osamu Shimomura
, a Japanese citizen, was born 1928 in Kyoto, Japan. He received his Ph.D. in organic chemistry 1960 from Nagoya University, Japan. first isolated GFP from the jellyfish Aequorea victoria, which drifts with the currents off the west coast of North America. He discovered that this protein glowed bright green under ultraviolet light.

Martin Chalfie demonstrated the value of GFP as a luminous genetic tag for various biological phenomena. In one of his first experiments, he coloured six individual cells in the transparent roundworm Caenorhabditis elegans with the aid of GFP.

Roger Y. Tsien contributed to our general understanding of how GFP fluoresces. He also extended the colour palette beyond green allowing researchers to give various proteins and cells different colours. This enables scientists to follow several different biological processes at the same time.

Related: 2007 Nobel Prize in ChemistryNobel Laureate Initiates Symposia for Student ScientistsNobel Prize in Chemistry (2006)Webcasts by Chemistry and Physics Nobel Laureates

Stanford Gets $75 Million for Stem Cell Center

Stanford gets $75 million for stem cell center

With today’s announcement, Lokey more than doubles his commitment. School officials say he is the lead contributor for a $200 million stem cell research building that will break ground Oct. 27 and be finished in the summer of 2010. In a statement released by the medical school, Lokey said stem cells would be “as significant as the silicon chip that created Silicon Valley,” producing treatments for disease and saving lives.

He said he was driven to fund research after President Bush, in August 2001, forbid the use of federal funds for stem cell research that involved the destruction of human embryos. “It’s very narrow-minded,” Lokey said of the position. “This is about lives being saved.”

Some 350 scientists will work in the 200,000-square-foot Lorry I. Lokey Stem Cell Research Building, the school said. The center is also getting a $43.6 million grant from the California Institute for Regenerative Medicine. The institute, the state’s $3 billion stem cell funding unit, was created by a 2004 state initiative from research advocates opposed to Bush’s restrictions.

Related: Chinese Stem Cell TherapiesScientists Cure Mice Of Sickle Cell Using Stem Cell TechniqueFunding Medical Researchpost on funding science

Why is it Colder at Higher Elevations?

John Hunter at Hurricane Ridge in Olympic National Park

I know it is colder at higher elevations (there is snow on the top of mountains when no snow is left on the bottom). When I was hiking this summer in Colorado and it started snowing I thought about why it was colder in higher elevations. My guess was that it was mainly due to lower air pressure and being higher up in the atmosphere where air was cooler than is was closer to sea level.

So I did some research online and the main explanations seem to be that at higher elevations the air pressure is lower (molecules and atoms under less pressure move more slowly which means the temperature is less).

Hot air does rise, but the amount of hot air is minor compared to the existing cold air in the atmosphere. So when hot air rises from the ground it is cooled down before getting far off the earth’s surface. And as it rises the pressure decreases, which cools it down.

Mountain Environments report, United Nations Environment Programme:

Air temperature on average decreases by about 6.5° C for every 1,000 m increase in altitude; in mid latitudes this is equivalent to moving poleward about 800 km. The dry dust-free air at altitude retains little heat energy, leading to marked extremes of temperature between day and night.

Photo of John Hunter at Hurricane Ridge in Olympic National Park.

Related: Why is the air cooler at higher altitudes?Why is the Sky Blue?scientific explanations for what we experienceFlint and Steel: What Causes the Sparks?Mount Rainier National Park PhotosLow air pressure decreases temps at high elevation
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Astronomers Find a Planet Denser Than Lead

Astronomers find a planet denser than lead

Meet the planet COROT-exo-3b. It orbits a star slightly larger, hotter, and brighter than the Sun. The star is not an unusual one in any way, but the planet is definitely weird: it orbits the star in just over 4 days, which is pretty close in, though not a record breaker in and of itself. What’s bizarre is that it has about the same diameter of Jupiter, but has 21.6 times Jupiter’s mass. That makes it denser than lead.

This planet is challenging to models. How did it form? It most likely formed farther out from the star — gravitational influences make it hard for a large planet to form close to a star — and then gradually moved in.

It was discovered by COROT, an orbiting European Space Agency mission designed to look for stars that dip in brightness as an orbiting planet passes in front of them. That gives the size of the planet (the amount the light dims is proportional to the size of the planet).

As a planet (the alternative is classifying it as a brown dwarf – a failed star, not a planet), COROT-exo-3b would be the densest known planet.

Related: COROT discovery stirs exoplanet classification rethinkPlanet, Less Dense Than Cork, Is DiscoveredHot Ice PlanetPhysics May Need a Revision

Milestones on the Voyage to the Bottom of the Sea

Dive! Dive! Dive!

0 FEET: EPIPELAGIC ZONE
Ample sunlight penetrates down to 650 feet, making photosynthesis possible. With abundant plant life (read: food), this zone is the most densely populated with fish.

656 FEET: MESOPELAGIC ZONE
Too deep to support photosynthesis: The fish that survive here are sit-and-wait predators that tend to have large mouths and specialized retinas to increase light reception.

1,640 feet: Maximum diving depth of the blue whale.
1,969 feet: The Deep Sound Channel, a layer in which acoustic signals travel far and fast.
1,969 feet: Maximum diving depth of nuclear-powered attack subs.

3281 FEET: BATHYPELAGIC ZONE
The ocean is dark at this level; the only glow is from bioluminescent animals. There are no living plants, and creatures subsist by eating the debris that falls from the levels above, including dead or dying fish and plankton.

3,281 feet: Maximum diving depth of the sperm whale. To navigate in the darkness, these whales emit high pitched sounds and use echoes to determine the location of prey.
3,937 feet: Maximum diving depth of the leatherback sea turtle.
4,000 feet: The domain of the Pacific sleeper shark, the largest toothed shark ever photographed. It can reach lengths of 28 feet.

5,187 feet: Maximum diving depth of the elephant seal.

13,123 FEET: ABYSSOPELAGIC ZONE
In the pitch-dark of the abyss, there is no light at all, the water temperature is near freezing. Of the few creatures found at these crushing depths, most are blind and have long tentacles – tiny invertebrates such as shrimp, basket stars, and small squids.

19,685 FEET: HADOLPELAGIC ZONE
Despite the intense pressure and frigid temperature in the deepwater trenches and canyons, life still exists here, especially near hydrothermal vents on the ocean floor. Invertebrates such as starfish actually thrive.

Related: Ocean LifeGiant Star Fish and More in Antarcticaocean related postsFemale Sharks Can Reproduce Alone