WEST LAFAYETTE, Ind. - A fiber-optic sensor created by a team of Purdue University researchers that is capable of measuring oxygen intake rates could have broad applications ranging from plant root development to assessing the effectiveness of chemotherapy drugs.
The self-referencing optrode, developed in the lab of Marshall Porterfield, an associate professor of agricultural and biological engineering, is non-invasive can deliver real-time data, holds a calibration for the sensor's lifetime and doesn't consume oxygen like traditional sensors that can compete with the sample being measured. A paper on the device was released on the early online version of the journal The Analyst this week.
"It's very sensitive in terms of the biological specimens we can monitor," Porterfield said. "We don't only measure oxygen concentration, we measure the flux. That's what's important for biologists."
Mohammad Rameez Chatni, a doctoral student in Porterfield's lab, said the sensor could be used broadly across disciplines. Testing included tumor cells, fish eggs, spinal cord material and plant roots.
Cancerous cells typically intake oxygen at higher rates than healthy cells, Chatni said. Measuring how a chemotherapy drug affects oxygen intake in both kinds of cells would tell a researcher whether the treatment was effective in killing tumors while leaving healthy cells unaffected.
Plant biologists might be interested in the sensor to measure oxygen intake of a genetically engineered plant's roots to determine its ability to survive in different types of soil.
"This tool could have applications in biomedical science, agriculture, material science. It's going across all disciplines," Chatni said.
The sensor is created by heating an optical fiber and pulling it apart to create two pointed optrodes about 15 microns in diameter, about one-tenth the size of a human hair. A membrane containing a fluorescent dye is placed on the tip of an optrode.
Oxygen binds to the fluorescent dye. When a blue light is passed through the optrode, the dye emits red light back. The complex analysis of that red light reveals the concentration of oxygen present at the tip of the optrode.
The optrode is oscillated between two points, one just above the surface of the sample and another a short distance away. Based on the difference in the oxygen concentrations, called flux, the amount of oxygen being taken in by the sample is calculated.
It's the intake, or oxygen transportation, that Porterfield said is important to understand.
"Just knowing the oxygen concentration in or around a sample will not necessarily correlate to the underlying biological processes going on," he said.
Porterfield said future work will focus on altering the device to measure things such as sodium and potassium intake as well. The National Science Foundation funded the research.
Writer: Brian Wallheimer, Purdue University
Rifat Fatima Astrologist
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New Multi-Use Device Can Shed Light On Oxygen Intake
Raging fire threatens century-old observatory
The wildfire ravaging the mountains north of Los Angeles drew within a half-mile of the revered Mount Wilson Observatory Monday, threatening the birthplace of modern astronomy as well as a virtual forest of communication towers that serve the region. Firefighters protecting Mount Wilson retreated Sunday but continued to dump flame retardant around the towers, transmitters and telescopes from the air. They said little could be done to stop the advancing flames, or predict how much damage would be done if the blaze ascends the 5,700-foot peak. link...
Why Sun's Atmosphere Is 'So Darned Hot'
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3,700-year-old wall discovered in Jerusalem
The 26-foot-high wall is believed to have been part of a protected passage built by ancient Canaanites from a hilltop fortress to a nearby spring that was the city's only water source and vulnerable to marauders.
The discovery marks the first time archaeologists have found such massive construction from before the time of Herod, the ruler behind numerous monumental projects in the city 2,000 years ago, and shows that Jerusalem of the Middle Bronze Age had a powerful population capable of complex building projects, said Ronny Reich, director of the excavation and an archaeology professor at the University of Haifa.
The wall dates to the 17th century B.C., when Jerusalem was a small, fortified enclave controlled by the Canaanites, one of the peoples the Bible says lived in the Holy Land before the Hebrew conquest. The kingdom thought to have been ruled from Jerusalem by the biblical King David is usually dated to at least seven centuries later. link...
African tree acts as 'fertilizer factory' for crops
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Mars Canyon Formed When Plug Was Pulled, Study Suggests
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MUSIC MADE FOR MONKEYS
Music may have charms to "soothe the savage breast," but that doesn't mean the same music that soothes humans will charm other species. Monkeys, for example, aren't much affected by human music. To find out whether any kind of music could affect a monkey's mood, a musician and a primatologist created tunes tailor-made for cotton-top tamarins. They report that the experiment worked - but the melodies are unlike anything you've ever heard. The music that mellows out a monkey consists of long, high-pitched tones that sound squeaky to human ears. "To me, that sounds like fingers scratching on a blackboard," said Charles Snowdon, a primate researcher from the University of Wisconsin at Madison. At the other extreme, the monkeys' equivalent of a thriller-movie soundtrack sounds like a fast-stuttering engine, overlaid with string-quartet screeches. "I can't even imagine dancing to it," Snowdon said. But based on the reviews reported in this week's issue of the journalBiology Letters, the tamarin tunes were a certifiable hit. link..
own calm, friendly calls. But the monkeys became more agitated when researchers
played music that contained elements of their own threatening or fearful calls.
Listen to arousing monkey music and calming music (Copyright David Teie).
Newfound Planet Might Be Near Death
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New Origin of Life Proposed: Zinc & Zap
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Life's Evolution May Depend on Galaxy
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HOW GAMES CHANGE YOUR BRAIN
One of the earliest and most noted studies in the field was conducted back in 1992 by neuroscientist Richard Haier at the University of California at Irvine, who looked at how frequent sessions with the Tetris video game changed the players' brains. The game requires players to fit colorful puzzle pieces together at a quickening pace as they fall from the top of the screen. Back then, Haier used brain scans to discover that some parts of the brain actually used less glucose as the players became more skilled at the game. The "Tetris effect" illustrated how video-game training could make brains work more efficiently - an idea that eventually led to a whole host of brain-training games. Now Haier serves as a consultant to Blue Planet Software, the company that markets Tetris, and he was asked to follow up on his 17-year-old research using the new tools available to neuroscientists. Haier recruited three colleagues - Sherif Karama from the Montreal Neurological Institute, Leonard Leyba from the New Mexico-based Mind Research Network and Rex Jung, a clinical neuropsychologist at the University of New Mexico. They came up with an experiment that budgeted out at "under $100,000," with the expense picked by Blue Planet, Haier said. link...
Tropical Storm Spotted on Saturn's Moon Titan
But that's exactly what they found on this beguiling moon, home to a weather system both eerily familiar and perplexingly strange. The discovery was announced today. In many ways Titan's climate resembles that of Earth, but instead of a water cycle, Titan has a methane cycle. Clouds, rain and lakes all exist on Titan, but they are all made of methane. In the moon's frigid climate, any water is frozen into rock-hard ice. Shouldn't be there Clouds of vaporized methane are not uncommon on Titan, though they have never before been observed in Titan's tropics. But in April 2008, astronomers using the Gemini North telescope and NASA's Infrared Telescope Facility in Hawaii spotted a severe storm covering 1.2 million square miles (3 million square kilometers) over the equator. "The models predicted that the equatorial region should be very dry and should not support cloud formation," said astronomer Henry Roe of Lowell Observatory in Arizona. "But this episode created clouds over both the equator and the south pole. We don't know what set off that sequence, but something gave a pretty good kick to the atmosphere." Scientists suspect the storm's trigger may have been some kind of geologic activity on the moon's surface, such as a geyser or new mountain range forming. Atmospheric effects may also have set off the storm. Whatever the cause, once the clouds were established they seem to have spread throughout Titan's atmosphere in waves. The situation is a new wrinkle in the study of this complex moon. "It's an amazing place because it is deeply familiar to us, being from Earth, in terms of the processes - clouds forming, rainfall, carved out channels on the surface, huge fields of what look like sand dunes," Roe told SPACE.com. "But the materials that are involved are quite alien." link...
Giraffe of the Mesozoic’ unearthed in China
Dinosaur stood about 39 feet long, nearly 10 feet tall and weighed 10 tons
Remains of a dinosaur, nicknamed the "giraffe of the Mesozoic" due to its long neck and forelimbs, were recently discovered in China, according to a paper in the Proceedings of the Royal Society B.The dinosaur, Qiaowanlong kangxii, is the firstEarly Cretaceous brachiosaur ever found in China.
Its name refers to a famous Qing Dynasty emperor, Kangxi, and also contains the words for "bridge," "bend in a stream," and "dragon," references to the site as well as a dream the emperor is said to have had. link..
