Trash Rises to Commodity Status
The saying “One man’s trash is another’s treasure” is being demonstrated daily ever 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 that the exchange will help create a more stable marketplace for recyclables, provide timely and accurate price information as well as giving buyers a better assurance of quality.
Salt Diet: Excessive salt is as harmful to plants as it is to some humans. The annual losses in agriculture due to sodium accumulation in soils and plants is estimated to be on the order of $500 million in California alone. In countries where artificial irrigation is frequently used, approximately 30% of agricultural land has become almost useless because of high sodium levels.
A major step toward putting plants on a low-salt diet was outlined in the Dec. 8 issue of the journal Science by biologists at UC San Diego. The biologists reported how they created mutant plant genes that block the uptake of salt in yeast cells. The technique offers a potentially new approach for genetically engineering salt-tolerant plants of agricultural importance.
In plants, a gene controls the so-called high-affinity potassium uptake pathway in the pores of roots that selectively takes up potassium, an important plant nutrient. However, under salty conditions, this same pathway encourages the uptake of sodium, inhibiting the passage of potassium into the plant. In the mutated gene, however, sodium was less effective in blocking potassium and the uptake of toxic sodium was significantly reduced. The researchers are now trying to engineer other mutants that are even more salt tolerant than the ones already created.
Heart Monitor: Currently doctors assess the threat of heart rejection in heart transplant patients by taking a biopsy of heart tissue for analysis by a pathologist. The problem with this approach is that it can take up to several days to determine whether the body is rejecting the implanted heart.
Now researchers at Ohio State University have come up with a device that could lead to earlier detection of impending organ rejection in heart transplant patients. Because research suggests that high impedance to an electrical current is an early sign of heart rejection, the device measures the impedance to electrical current flow through heart muscle tissues. The device uses a software program developed by Roger Dzwonczyk, an electrical engineer in anesthesiology and one of the device’s creators. The program runs on a commercially available microcomputer that is attached to two electrodes implanted during heart transplant surgery. The electrodes are used by doctors to pace the heart if it develops an irregular heart beat after the surgery. W hen hooked to the electrodes, Dzwonczyk’s device emits a small, harmless electrical current to the heart tissue and measures the impedance. Human trials of the device are expected to last about two years.
Ripe Idea: As the holidays progress, refrigerators become crammed with food doomed to spoil before it gets eaten. But as you face the yellowing broccoli and wilting greens, take heart. Scientists at the University of Wisconsin may have found a way to curb that spoilage. Plant scientists Anthony Bleeker and Eric Schaller have discovered the first plant hormone receptor responsible for ripening and aging in plants. This receptor regulates everything from leaves falling off trees and bananas turning brown to flowers dropping their petals.
Controlling food loss from spoilage is more than just an inconvenience for consumers. In terms of vegetable crops, estimates are that about 50% of all crops produced are lost to spoilage between harvest and purchase by consumers. Many other fruits ripen too quickly and fall off the vine long before they can be harvested.
The discovery of the receptor--the protein that binds a hormone in a cell--is important to the understanding of how plants use a hormone that tells the plant to begin aging or ripening. In the future Bleeker believes that researchers might be able to breed controls into plants that will make them less susceptible to spoilage. Suppressing the hormone response in cut flowers would give longer life to a bouquet from the floral shop.
