Think twice before catching that cold, white snowflake drifting by, on your tongue...

You've heard of acid rain, now there's ...

Study shows bacteria are common in snow

By RANDOLPH E. SCHMID, AP Science Writer WASHINGTON - Those beautiful snowflakes drifting out of the sky may have a surprise inside — bacteria. Most snow and rain forms in chilly conditions high in the sky and atmospheric scientists have long known that, under most conditions, the moisture needs something to cling to in order to condense. 

Now, a new study shows a surprisingly large share of those so-called nucleators turn out to be bacteria that can affect plants. "Bacteria are by far the most active ice nuclei in nature," said Brent C. Christner, an assistant professor of biological sciences at Louisiana State University. Christner and colleagues sampled snow from Antarctica, France, Montana and the Yukon and they report their findings in Friday's edition of the journal Science.

In some samples as much as 85 percent of the nuclei were bacteria, Christner said in a telephone interview. The bacteria were most common in France, followed by Montana and the Yukon, and was even present to a lesser degree in Antarctica.

The most common bacteria found was Pseudomonas syringae, which can cause disease in several types of plants including tomatoes and beans. The study found it in 20 samples of snow from around the world and subsequent research has also found it in summer rainfall in Louisiana. The focus on Pseudomonas in the past has been to try and eliminate it, Christner said, but now that it turns out to be a major factor in encouraging snow and rain, he wonders if that is a good idea.

Would elimination of this bacteria result in less rain or snow, or would it be replaced by other nuclei such as soot and dust? "The question is, are they a good guy or a bad guy," he said, "and I don't have the answer to that." What is clear is that Pseudomonas is effective at getting moisture in a cloud to condense, he pointed out. Killed bacteria are even used as an additive in snow making at ski resorts.

Which raises the question, Christner said, of whether planting crops known to be infected by Pseudomonas in areas experiencing drought might help increase precipitation there by adding more nuclei to the atmosphere. It has been known that microbes and insects and algae blow around in the atmosphere, Christner added, "but the atmosphere has not been recognized as a place where things are active. That has been changing in the last decade.

In a cloud you've got water, organic carbon," everything necessary to support a microorganism. Virginia K. Walker, a biologist at Queen's University in Kingston, Ontario, Canada, said other researchers have found bacteria serving as snow nuclei, but had not identified it as Pseudomonas. "It's one of those great bacteria ... you can find them anywhere," said Walker, who was not part of the research team. "They are really interesting."

Charles Knight, a cloud physics expert at the National Center for Atmospheric Research in Boulder, Colo., wasn't surprised by the finding, however. At relatively warm temperatures of just a few degrees below freezing, bacteria are "remarkably effective" at attracting ice formation, said Knight, who also was not part of the research group.

The study was supported by a Louisiana State University research grant. In a second paper published online by Science, researchers report that the amount of dust blown into the tropical Pacific over the last half-million years has varied widely between warm and cold periods. Dust also has important impacts on weather and climate ranging from serving as nuclei for rain to blocking some incoming radiation from the sun, and it also delivers minerals like iron that increase growth of plankton in ocean areas.

Cores of seafloor sediment were taken from locations across the tropical Pacific covering a period of 500,000 years. Researchers led by Gisela Winckler of the Lamont-Doherty Earth Observatory of Columbia University found that dust deposited in the ocean peaked during cold periods and was less during warm periods. Using isotopes, the scientists traced the dust on the western side to Asia and that on the eastern side to South America.

They say the reasons for the change are complex but in general it tends to be windier in cold periods meaning more dust gets blown around. They found that cold peaks occurred about every 100,000 years, with the last one at 20,000 years ago. The research was supported by the National Science Foundation and the Earth Institute at Columbia University.

Finally!! An explanation that doesn't include PMS'ing. Ladies!! You're gonna love this one! Men, you might be interested to know about this also.

            I continue to be amazed—in awe—of a God who not only had the power to create everything, but thought it up, as well.  Below are a couple of excerpts from Michael Denton’s Evolution: A Theory in Crisis.  What he describes is just a one cell of bacterium.

            “Although the tiniest bacterial cells are incredibly small, weighing less than 10^-10 gms, each is in effect a veritable micro-miniaturized factory containing thousands of exquisitely designed pieces of intricate molecular machinery, made up altogether of one hundred thousand million atoms, far more complicated than any machine built by man and absolutely without parallel in the non-living world.”

            “To grasp the reality of life as it has been revealed by molecular biology, we must magnify a cell a thousand million times until it is twenty kilometres in diameter and resembles a giant airship large enough to cover a great city like London or New York.  What we would then see would be an object of unparalleled complexity and adaptive design.  On the surface of the cell we would see millions of openings, like the portholes of a vast space ship, opening and closing to allow a continual stream of materials to flow in and out.  If we were to enter one of these openings we would find ourselves in a world of supreme technology and bewildering complexity.  We would see endless highly organized corridors and conduits branching in every direction away from the perimeter of the cell, some leading to the central memory bank in the nucleus and others to assembly plants and processing units.  The nucleus itself would be a vast spherical chamber more than a kilometre in diameter, resembling a geodesic dome inside of which we would see, all neatly stacked together in ordered arrays, the miles of coiled chains of the DNA molecules.  A huge range of products and raw materials would shuffle along all the manifold conduits in a highly ordered fashion to and from all the various assembly plants in the outer regions of the cell.

            We would wonder at the level of control implicit in the movement of so many objects down so many seemingly endless conduits, all in perfect unison.  We would see all around us, in every direction that we looked, all sorts of robot-like machines.  We world notice that the simplest of the functional components of the cell, the protein molecules, were astonishingly complex pieces of molecular machinery, each one consisting of about 3,000 atoms arranged in highly organized 3-D spatial conformation.  We would wonder even more as we watched the strangely purposeful activities of these weird molecular machines, particularly when we realized that, despite all our accumulated knowledge of physics and chemistry, the task of designing one such molecular machine—this is one functional protein molecule—would be completely beyond our capacity at present and will probably not be achieved until at least the beginning of the next century.  Yet the life of the cell depends on the integrated activities of thousand, certainly tens, and probably hundreds of thousands of different protein molecules.

            We would see that nearly every feature of our own advanced machines had its analogue in the cell: artificial languages and their decoding systems, memory banks for information storage and retrieval, elegant control systems regulating the automated assembly of parts and components, error fail-safe and proofreading devices utilized for quality control, assembly processes involving the principle of prefabrication and molecular construction.  In fact so deep would be the feeling of deja-vu, so persuasive the analogy, that much of the terminology we would use to describe this fascinating molecular reality would be borrowed from the world of late twentieth-century technology.

            What we would be witnessing would be an object resembling an immense automated factory, a factory larger than a city and carrying out almost as many unique functions as all the manufacturing activities of man on earth.  However, it would be a factory which would have one capacity not equaled in any of our own most advanced machines, for it would be capable of replicating its entire structure within a matter of a few hours.  To witness such an act at a magnification of one thousand million times would be an awe-inspiring spectacle.”