Wednesday, May 31, 2006
Buy her a beer and talk about old times.
Research involving more than 7,000 older women found that those who drink a moderate amount of alcohol have slightly higher levels of mental function than non-drinkers, particularly in verbal abilities . . .
understanding whether alcohol affects specific areas of cognition may shed light on the mechanisms that make it protective. Possible mechanisms include that alcohol increases levels of "good" cholesterol and lowers the risk of stroke, that it may decrease the formation of plaque that is associated with Alzheimer's disease and that it may increase the release of brain chemicals that affect learning and memory. . .
"Until we better understand the reasons why alcohol consumption is associated with better cognitive functioning, these results on their own are not a reason for people who don't drink to start or for those who drink to increase their intake."
Ok, don't buy her a beer if she doesn't drink or is already stoned.
Thursday, May 25, 2006
The Colorado river than Powell saw when he explored it for the post-bellum US in 1869 may have been more representative than the river we've seen since the turn of the century.
A new tree-ring-based reconstruction of 508 years of Colorado River streamflow confirms that droughts more severe than the 2000-2004 drought occurred before stream gages were installed on the river.
The new research also confirms that using stream gage records alone may overestimate the average amount of water in the river because the last 100-year period was wetter than the average for the last five centuries. . .
"The updated reconstruction for Lee's Ferry indicates that as many as eight droughts similar in severity, in terms of average flow, to the 5-year 2000-2004 drought have occurred since 1500."
Well, that's interesting but so what?
Allocations of Colorado River water made in the 1922 Colorado River Compact between the states of Arizona, California, Colorado, Nevada, New Mexico, Wyoming and Utah therefore overestimate the amount of river water available. Los Angeles, Las Vegas, Denver, Phoenix, Tucson and Albuquerque are among the many cities dependent on Colorado River water. . .
The underlying message from these new reconstructions remains the same: that Colorado River Compact allocations were based on one of the wettest periods in the past five centuries, and that droughts more severe than any in the last 100 years occurred before stream gages were installed. The most severe sustained drought (based on the lowest 20-year average) in the Upper Colorado River basin occurred in the last part of the 16th century. This reconstruction also shows that average annual flows on the Upper Colorado regularly vary from one decade to the next by more than 1 million acre-feet.
According to Eric Kuhn, general manager of the Colorado River Water Conservation District and an expert on Colorado River issues, "Water managers have always made critical water decisions based on a relatively short and often incomplete gaged record for the Colorado River. This study should be of keen interest because it shows that there were likely a number of long-term droughts more severe than what we experienced in the 1900s and during this century. The study should have enormous implications on how the river is managed."
This isn't new news. Previous studies decades ago said much the same, but this one is a bit more rigorous and largely confirms previous findings.
Cosmological membrane theory is an interesting speculation without evidence, or much evidence at any rate, and none of it unambiguous. Perhaps that will change in the next few years.
The framework Keeton and Petters developed predicts certain cosmological effects that, if observed, should help scientists validate the braneworld theory. The observations, they said, should be possible with satellites scheduled to launch in the next few years.
If the braneworld theory proves to be true, "this would upset the applecart," Petters said. "It would confirm that there is a fourth dimension to space, which would create a philosophical shift in our understanding of the natural world." . . .
The braneworld theory predicts that relatively small "black holes" created in the early universe have survived to the present. The black holes, with mass similar to a tiny asteroid, would be part of the "dark matter" in the universe. As the name suggests, dark matter does not emit or reflect light, but does exert a gravitational force.
The General Theory of Relativity, on the other hand, predicts that such primordial black holes no longer exist, as they would have evaporated by now.
"When we estimated how far braneworld black holes might be from Earth, we were surprised to find that the nearest ones would lie well inside Pluto's orbit," Keeton said.
Petters added, "If braneworld black holes form even 1 percent of the dark matter in our part of the galaxy -- a cautious assumption -- there should be several thousand braneworld black holes in our solar system."
But do braneworld black holes really exist -- and therefore stand as evidence for the 5-D braneworld theory?
The scientists showed that it should be possible to answer this question by observing the effects that braneworld black holes would exert on electromagnetic radiation traveling to Earth from other galaxies. Any such radiation passing near a black hole will be acted upon by the object's tremendous gravitational forces -- an effect called "gravitational lensing."
"A good place to look for gravitational lensing by braneworld black holes is in bursts of gamma rays coming to Earth," Keeton said. These gamma-ray bursts are thought to be produced by enormous explosions throughout the universe. Such bursts from outer space were discovered inadvertently by the U.S. Air Force in the 1960s.
Keeton and Petters calculated that braneworld black holes would impede the gamma rays in the same way a rock in a pond obstructs passing ripples. The rock produces an "interference pattern" in its wake in which some ripple peaks are higher, some troughs are deeper, and some peaks and troughs cancel each other out. The interference pattern bears the signature of the characteristics of both the rock and the water.
Similarly, a braneworld black hole would produce an interference pattern in a passing burst of gamma rays as they travel to Earth, said Keeton and Petters. The scientists predicted the resulting bright and dark "fringes" in the interference pattern, which they said provides a means of inferring characteristics of braneworld black holes and, in turn, of space and time.
"We discovered that the signature of a fourth dimension of space appears in the interference patterns," Petters said. "This extra spatial dimension creates a contraction between the fringes compared to what you'd get in General Relativity."
Petters and Keeton said it should be possible to measure the predicted gamma-ray fringe patterns using the Gamma-ray Large Area Space Telescope, which is scheduled to be launched on a spacecraft in August 2007.
I wonder how such a "philosophical shift in our understanding of the natural world" would affect society?
Friday, May 12, 2006
Work them to death.
"Preliminary indications from follow-up work in the laboratory suggest that voluntary exercise enhances UVB-induced apoptosis in the skin, and that it also enhances apoptosis in UVB-induced tumours. So, although UVB is triggering the development of tumours, exercise is counteracting the effect by stimulating the death of the developing cancer cells.
"Our studies may be the first to suggest an apoptotic mechanism for the effect of voluntary exercise in the development of cancer. In addition, we found that voluntary exercise decreased body fat and that the number of tumours decreased with decreasing amounts of fat. This effect may also play an important role in the mechanism and warrants further investigation, bearing in mind the growing rates of obesity in the Western world, particularly in the USA and UK," he said. . .
For the bowel cancer study, Dr Colbert and her co-authors used mice (APC Min mice) that had a genetic mutation that predisposed them to develop intestinal polyps. "Our studies are relevant for humans in that these Min mice have a mutation in one of the same genes, APC, that is also mutated in human colon cancer," she explained. "The protective effect of exercise and lower body weight in our mice is consistent with epidemiological evidence in humans that suggests higher levels of activity and lower body weight reduces the risk of colon cancer." . . .
"The exercising mice ran an average of 3.8 km a day, and the further they ran the fewer polyps they had. Exercise significantly reduced total polyp number and polyp size, as well as prolonging survival," said Dr Colbert. "On average there were 16 polyps per mouse in the exercising mice compared to 22 polyps in the control mice – a decrease of 25%."
As I sit here satiated after having worked my fill today, like every day, outdoors, on my feet, covering miles and miles though at a brisk walk rather than a run, in full sun though I wear a hat, not able to "pinch an inch" of fat on my tum even when sitting, it's good to think that this may be a health advantage. I may look like a leathery bag of straps and bones, but I feel pretty good and may do so for some time still.
Sunday, May 07, 2006
The Center for Responsible Nanotechnology (CRN) Task Force is publishing some essays.
For their first major project, the CRN Task Force chose to generate a range of independent essays identifying and defining specific concerns about the possibilities of advanced nanotechnology. As shown below, some of those essays were published in the March 2006 issue of the journal Nanotechnology Perceptions. The rest of the essays will be published in May 2006 in the next issue of the journal.
We encourage everyone to respond to this work and to future publications of the CRN Task Force with your questions, comments, and criticism.
Some are available for online reading now under the Gnu Free Documentation License (GFDL), some will be available soon but a couple are not GFDL licensed.
Wednesday, May 03, 2006
I'm a sharpening nut. It's a habit I picked up in my youth one year when I worked with an old immigrant cabinet maker. He told stories of how he had been an apprentice as a boy in the day when the punishment for mistakes was a beating from the master.
He wasn't allowed to use power tools until he could make a perfect cabinet, starting with a log, with nothing but hand tools. Then he could use power tools when it was faster and easier, though not otherwise better. You can't do such things with dull tools and he retained his mania for sharpness into his old age. I got infected too.
When my buddy lost he knife, left it in my shop, I found it, sharpened it, and returned it to him with a cautionary remark. I knew that he wasn't used to sharp blades. When I house sat for Nannette and Chuck I sharpened their kitchen knives. Left a cautionary note. I even sharpen my shovels. Digging is much easier.
Today I sharpened the lawn mower blade, but not just a regular sharpening, a scary sharpening where the last pass it with a diamond strop. What a difference! It's as if I had doubled the engine power and speed. In thick, tall stands that used to bog it down and need two slow passes to cut evenly it hardly strained the engine when mowed at a normal pace.
I should have known that would happen. I had wondered about it for some time but never put a great edge on the blade. People already made fun of me for sharpening my blade so well and so often, as if it was a waste of time or a compulsive habit. I wish that old man was still around. He would have chided me about my dull blade and I'd have done this really useful upgrade long ago.
Tuesday, May 02, 2006
A potential solution for all kinds of problems is computer driven fabricators. When mature these technologies may function at the nano scale and sip energy and materials. Current technologies build objects by whittling away excess mass from stocks. These technologies build objects up by depositing mass in the right places. An overview of current capabilities.
With new materials, more-efficient lasers, and faster computers, techniques such as selective laser sintering and direct metal deposition are producing parts, not just prototypes.
Since its introduction in the 1980s, rapid prototyping has evolved from a relatively simple modeling technique that allows design engineers to “test” their ideas in three dimensions to a sophisticated custom-manufacturing tool that may one day find its place alongside the copy machines at the local copy center or in the parts department at the local auto dealership.
I expect we will have home fabs. Have your fab make a fab for me. There are some interesting implications for intellectual property in a world where things are easily produced from CAD designs.