The Cutting Edge: COMPUTING / TECHNOLOGY / INNOVATION : Seat Cushion Eases a Painful Problem
People who use wheelchairs must contend with a costly and painful problem: the pressure sores that are associated with sitting in one place for a long time. The annual medical cost of treating such sores is estimated at $3 billion to $5 billion.
The standard method of preventing the sores has been the use of contoured seats, which distribute pressure as uniformly as possible. But the seats have achieved only limited success. A better method, involving a battery-powered pneumatic seat cushion, was recently unveiled at the University of New Mexico.
The Generic Total Contact Seat was developed through a joint venture involving the New Mexico Technology Deployment Pilot Project and Numotech Inc. of Sun Valley, which will manufacture the seat. The NMTDPP comprises Sandia National Laboratories, the Energy Department, the University of New Mexico’s Research Institute for Assistance and Training Technologies and Laguna Industries Inc.
The cushion, which rests on the seat of a wheelchair, features four pairs of air bladders that are cyclically inflated and deflated by battery-powered pistons. This prevents prolonged pressure on a given area of the buttocks. Such pressure can retard blood flow and oxygen exchange and cause tissue to become weakened. Pressure ulcers form when the right combination of moisture and temperature conditions allow bacteria to grow and attack tissue.
Early work on the “active” cushion was done by researchers from UCLA and the Sepulveda Veterans Medical Center in Los Angeles. The device developed together with Numotech was too large and clumsy to be used in a home environment, but by incorporating the power and pumping system directly into the cushion, Sandia engineers were able to reduce weight and power consumption by half.
Talking Plants: Plant lovers believe that talking to their plants makes them grow better. Now Bill Lucas, a professor of plant biology at UC Davis, has discovered that plant cells themselves engage in a sophisticated conversation using a greater variety of proteins and hormones than once thought.
Understanding this “conversation” could help scientists devise ways to stop the spread of viruses that use the protein transport system used by plant cells to communicate.
Until now, a rudimentary form of communication among plant cells was assumed to take place through narrow portals called plasmodesmata, which connect the cells into a network that allows easy passage of nutrients such as sugars. Because these portals appeared too narrow and rigid for any but the smallest molecules to pass through, signaling was thought to be accomplished by small molecules only--growth hormones and small proteins called peptides.
Lucas discovered that the plasmodesmata appear to be flexible. At the proper signal, they expand to allow the passage of large molecules such as viruses from one cell to the next, suggesting that the virus has somehow stolen the “key” to open the plasmodesmata channel.
Buy Glass, Sell Paper: The saying “One man’s trash is another’s treasure” is being demonstrated daily since the recent launch of the Chicago Board of Trade Recyclables Exchange.
The exchange is a centralized electronic marketplace for buying and selling such recyclable materials as glass, plastic and paper and was funded in part by the National Institute of Standards and Technology.
Participants will be able to use an online bulletin board to buy and sell recyclable materials of various grades. The Clean Washington Center (a division of the Washington State Department of Community, Trade and Economic Development) developed both the testing protocols and the standardized quality definitions for recyclable materials that will be used in this worldwide market.
Proponents believe the exchange will help create a more stable marketplace for recyclables, provide timely and accurate price information and give buyers a better assurance of quality.
Hold the Salt: It has been assumed for years that all deeply buried salt layers are nearly impermeable and therefore a good barrier in the storage of dangerous waste products. But new research from the Weizmann Institute in Rehovot, Israel, brings that assumption into question.
While previous investigations by scientists have shown that certain deeply buried salt deposits are nearly impermeable, not all of them are, the Israel researchers found, and poisonous materials stored in some of these layers might escape into the soil and contaminate ground water used for agriculture or domestic purposes.
The conclusions were based on studying a 10,000-year-old salt layer along the western coast of the Dead Sea.
Instead of being impermeable, the salt was highly conducive to the flow of liquids and heavily saturated with water. The researchers found that ground water had been seeping into the layer and absorbing some of its salt.
In fact, the rate of water flow was actually higher in the salt formation than in the surrounding layers of clay and gravel. Moreover, laboratory tests showed individual salt crystals to be as conducive as sand to the flow of liquids.
