Sunday, September 27, 2009
Dr. Ian M. Paul and colleagues at Penn State College of Medicine conducted a study involving 105 children age 2 to 18 with upper respiratory tract infections who were sick for seven days or less and experienced symptoms during the night. Thirty-five children were randomly assigned to receive an age-appropriate dose of honey, 33 to receive dextromethorphan and 37 to receive no treatment for one night within 30 minutes of bedtime. The children's parents were asked to complete a survey assessing their child's cough and sleep difficulty the night before their assigned treatment and then again the night after treatment.
Honey was found to yield the greatest improvement followed by dextromethorphan, while no treatment showed the least improvement in cough frequency, cough severity, cough bothersome to child, child's sleep and parent's sleep.
"In paired comparisons, honey was significantly superior to no treatment for cough frequency and the combined score, but dextromethorphan was not better than no treatment for any outcome," the authors reported. "Comparison of honey with dextromethorphan revealed no significant differences.
"While our findings and the absence of contemporary studies supporting the use of dextromethorphan continue to question its effectiveness for the treatment of cough associated with upper respiratory tract infections, we have now provided evidence supporting honey, which is generally regarded as safe for children older than 1 year, as an alternative," the authors conclude.
Source: JAMA/Archives journals
Wednesday, September 23, 2009
Furnaces Recalled by Northwest Manufacturing Due to Fire Hazard (Thu, 17 Sep 2009 15:00:00 GMT) The temperature gauge can fail and cause fire in the fuel storage hopper, posing a fire and burn hazard to consumers.
Garlic Press/Slicers Recalled by Trudeau Corporation Due to Laceration Hazard (Wed, 16 Sep 2009 18:00:00 GMT) The garlic duo's slicer blades can break during use, posing a laceration hazard to users.
Sunday, September 20, 2009
There's a place down by the river where the bank is wide and sandy. It overlooks a low-lying rock dam over which the river spills. Behind that dam, the water is flat and calm -- perfect for skipping stones across.
My son stops here every time we come by on walks or bike rides. He scrambles down to the water's edge, scavenges for flat stones just the right size to fit between his palm and forefinger. This is where he learned to skip stones.
I started skipping stones as a toddler beside a reservoir in Montana. My family spent many weekends camped along its shore. As soon as I grew bored watching the folks fish, which didn't take long, I took to skipping stones -- well away from the anglers, of course. I threw for hours.
Mastery of the art didn't come easy, I am sure. My son struggled through many unsuccessful attempts to imitate my slicing sidearm motion. His stones always fell into the water with a thud, making a single splash, until one day -- quite without warning -- he sent one skimming across the river one, two, three and four skips. He's been skipping without coaching or instruction ever since.
Finding the right stone is the real trick to successful stone skipping. It needs to be heavy enough to carry well, but also small enough to fit comfortably in yourhand. It should be flat, with rounded edges, the kind that most often lie along the banks of rivers. Locating a good supply beside a lake, far from moving water, can be difficult.
You wedge the stone along its edges between your forefinger and thumb, lean over to the side, and fling the stone sidearm while letting go of the thumb first to encourage a fast spinning motion. The stone should fly from your hand horizontal to the water and barely skim across the surface as gravity gradually brings it down.
A French physicist, Lydéric Bocquet, reduced the skipping action of the spinning stone to a mathematical formula. His equations showed that the faster it is travelling, the more times it will bounce. To bounce at least once without sinking, the stone needs to be travelling at a minimum speed of about 1 kilometer per hour.
The spin is critical, because it keeps the stone fairly flat from one bounce to the next. It also has a gyroscopic effect, preventing the stone from tipping and falling sideways into the water.
To match the world record of 38 bounces -- set by Jerdone Coleman-McGhee on the Blanco River in Texas in 1992 -- Bocquet calculates that a stone 10 centimeters wide would have to be travelling at about 40 kilometers per hour and spinning at 14 revolutions a second.
My son and I are not throwing for any records, but we do keep count of the bounces and with each successive throw we try to match or better our day's best. Sometimes it's just the beauty of the motion that captivates, or the thrill of seeing the stone arc through space.
I've heard that the Inuits of Alaska skim rocks across icefields and that Bedouin tribesmen of Arabia do the same thing on sand. In Scotland, the World Stone Skimming Championship is held each September on the island of Easdale, famous for its slate deposits and the millions of flat water rounded pebbles on its beaches.
There must be something powerfully primal about an activity that compels young boys to forego video games and grown men to set aside their ambitions to engage in a sport without prey or pay. Our genetic memories keep bringing us back to these shores where we've played for millenia. The same stone, perhaps, that flew from the fist of a pre-Columbian child is pulled from up from the earth by this 21st century youngster, wedged between his fingers and flung back out into space, skimming one, two, three, four and five (!) times across the surface before sinking back down into the depths of time.
Sunday, September 6, 2009
Plants get sick. They develop soft rot and leaf spot and cankers of all sorts. They suffer ulcerous lesions, mildews, and various wilts and scabs.
Apple trees get fire blight, which blackens their leaves and twigs and is sometimes fatal. Potatoes are susceptible to late blight, as 19th century Ireland learned too well, and grapes are vulnerable to powdery mildew, which nearly wrecked the French wine industry.
In the U.S. alone, there are more than 25,000 known plant diseases causing crop losses of several billion dollars annually.
Figuring out how plants defend themselves against disease and bolstering those defenses has been a priority for agricultural researchers.
Much study has been done on the activation of the "defense genes" which encode the proteins of plant cells with protective functions. Using gene splicing techniques, scientists have learned how to activate the cell's defenses before a pathogen attacks, an important breakthrough in crop protection.
Yet, while scientists have looked closely at the cells of plants and figured out how they protect against disease, until lately they passed over one peculair aspect of resistance: cell suicide.
When a disease appears on a plant the cells at the front lines often collapse and die. This has been called a "hypersensitive response" because it happens before the cells have actually been attacked.
At the Salk Institute for Biological Studies scientists closely observing the hypersenitive response noticed a buildup of hydrogen peroxide inside the cells.
The scientists watched as the hydrogen peroxide caused a cross-linking of structural polymers in the cell wall, making it tougher and harder to penetrate, much like a self-sealing tire. The chemical also triggered the pre-programmed death of the suicide cells, if you will, and alerted other nearby cells to the presence of an invader.
By checking the advance of the disease and alerting other defense cells, suicide cells give the plant a chance to produce antibiotics and raise other defenses. Their sacrifice, in some cases, makes a life-or-death difference to the plant.
Knowing how the hypersensitive response works will lead to techniques for stimulating it artificially. Plants will soon be genetically engineered to produce hydrogen peroxide in their suicide cells more readily after a pathogen attack.
How this will effect crop protection efforts and food supplies remains to be seen. But unlike attempts to control disease by attacking pathogens, this approach delivers its prescription directly to the plant: Get well soon.
"The structure is beautiful, with its heavy timbers supporting a roof that provided welcome shade on a hot August day," writes contributing writer Joni Carter in the News & Record.
The market is open from 6 a.m. until 1 p.m. Tuesdays, Thursdays and Saturdays from May until November.
Thursday, September 3, 2009
Agricultural Research Service (ARS) scientist chemist Milagros Hojilla-Evangelista has devised a corn-germ formulation for use in sprayline coating, a procedure that applies a liquid adhesive to wood surfaces using overhead nozzles.
In tests, she applied the corn-germ-based glue to one side of 12-inch by 12-inch southern pine veneers, then hot-pressed them following industry-standard conditions to produce three-ply panels. Her analysis of the material found the bonding strength of the corn-germ-based glue to be similar to that of the wheat-flour-based formula used as extender for most plywood glues.
Currently, most corn germ is fed to poultry and other livestock animals. But if America’s biorefineries increase corn-ethanol production from the current 9 billion gallons to 15 billion gallons by 2015, as planned, a surplus of corn germ could be looming on the horizon.
Source: Agricultural Research Service