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Comment by Dr. Krishna Kumari Challa on January 31, 2016 at 11:04am

Till now we are under the impression that earthworms are highly beneficial to plants. But listen to this:  Earthworms not always beneficial, may threaten plant diversity!

A new study suggests that an abundance of earthworms in soils could lead to reductions in the number of trees and and other plant species.

Contrary to the popular belief that these creatures and beneficial to the natural ecosystem, the scarcity of these invertebrates can be a threat to certain plant species, causing adverse effects on the ecosystem.

Researchers from Canada's Université Laval and Université de Sherbrooke visited sugar maple forests in Quebec province where they found half of which were populated by earthworms.

Their analysis revealed a correlation between the number of earthworms and the abundance and diversity of certain understory species as they found that new shoots of red maple, striped maple, American beech, and two fern species became rarer as populations of these invertebrates increased.

"The most likely explanation is that the earthworms consume organic matter in forest litter," said Line Lapointe, a professor at Université Laval's faculty of science and engineering and the study's lead author.

"This results in soils that can't hold as much moisture, and that in turn interferes with seed germination and the ability of some species' plantlets to survive," she added.

Earthworms have started to change plant composition in sugar maple forests, according to the researchers.

Researchers suggest that earthworms used for bait should never be released in the forest, instead they be thrown into the lake to avoid overpopulation in the ecosystem.

The study has been published in the journal Forest Ecology and Management.

Comment by Dr. Krishna Kumari Challa on January 30, 2016 at 7:39am

Electrons do not orbit around an atomic nucleus like planets around a star. This outdated model of the atom (called the Bohr-Rutherford model) is still taught in schools, but only as an introduction to modern ideas about the atom.

Max Born showed us that electrons do not have a definite position, but instead exist as probability wave functions that describe how likely it is that the electron would be at a particular point in its atomic orbit. That is to say, the electron exists in a superposition of all possible locations around the atom. Werner Heisenberg discovered that it isn't until an electron is observed (detected by an instrument) that its wave function collapses and it takes on a discrete location.

So, really, electrons do not orbit around a nucleus; they exist in all possible locations around that nucleus simultaneously. Quantum mechanics!

Electrons don't orbit around atomic nucleuses like planets around a star. But that doesn't mean that they aren't moving.

The probability density for an electron is symmetric around the nucleus, so the average velocity would cancel out to zero. So let's calculate a typical speed from the square-root of the average velocity squared instead. (This is the referred to as root-mean-squared or r.m.s. for short.)

It's actually pretty easy to figure out the r.m.s. velocity for a typical electron from a few physics facts.

First, we need to the know the binding energy of the electron to the nucleus. We might as well assume it's in hydrogen, the simplest atom, so it has total binding energy of E = -13.6 eV (electron-volts):

Next, we need to know what part of the energy is kinetic (moving) instead of potential (due to the electric force holding the atom together). For closed orbits (electrons or planets), there is very handy relationship known as the Virial Theorem [1]. The Virial Theorem tells us that for particles experiencing an attractive 1/r21/r2 force like that between opposite charges, the average kinetic energy is equal to the negative of the total energy:
⟨T⟩=−E⟨T⟩=−E.

To calculate the r.m.s. velocity, we just need the non-relativistic [2] formula relating kinetic energy T and velocity v:
T=12mv2T=12mv2,
where m is the mass of the object.

Solving the above equations, we find:
vrms=−2Em−−−−√.vrms=−2Em.
Plugging in the binding energy and mass of an electron, we see that our hypothetical electron is moving at 2.2*10^6 m/s [3] or just shy of 5 million mph. Fast, but still about a factor of 100 times slower than the limit, the speed of light.

Comment by Dr. Krishna Kumari Challa on January 29, 2016 at 7:08am

A new global analysis of seafood found that fish populations throughout the world's oceans are contaminated with industrial and agricultural pollutants, collectively known as persistent organic pollutants (POPs). The study from researchers at Scripps Institution of Oceanography at UC San Diego also uncovered some good news?concentrations of these pollutants have been consistently dropping over the last 30 years. The findings, reported in the Jan. 28, 2016 issue of the journal PeerJ, were based on an analysis by Scripps researchers Lindsay Bonito, Amro Hamdoun, and Stuart Sandin of hundreds of peer-reviewed articles from 1969-2012. The pollutants studied included older 'legacy' chemicals, such as DDT and mercury, as well as newer industrial chemicals, such as flame retardants and coolants.
Although POPs were found in fish in all of the world's oceans, the researchers say that concentrations in the consumable meat of marine fish are highly variable, where one region or group of fish may find concentrations of POPs that vary by 1,000-fold. The analysis revealed that average concentrations of each class of POP were significantly higher in the 1980s than is found today, with a drop in concentration of 15-30 percent per decade.

"This means that the typical fish that you consume today can have approximately 50 percent of the concentration of most POPs when compared to the same fish eaten by your parents at your age," said Bonito, the lead author of the study. "But there still remains a chance of getting a fillet as contaminated as what your parents ate.
The authors caution that although pollutant concentrations in marine fish are steadily declining, they still remain quite high, and that understanding the cumulative effects of numerous exposures to pollutants in seafood is necessary to determine the specific risk to consumers.
Source: University of California - San Diego
and Science news

Comment by Dr. Krishna Kumari Challa on January 27, 2016 at 10:28am

Tenacious proteins similar to those implicated in Alzheimer’s disease could help purify polluted water.

A newly designed membrane uses thin amyloid protein fibers to pull heavy metals and radioactive wastes out of water. The membranes can capture more than their own weight in some contaminants, scientists in Switzerland report January 25 in Nature Nanotechnology.
Specifically, the team converted milk proteins into fibers of durable amyloid protein. Other amyloids are infamous for building up in the brains of Alzheimer’s patients, but the team put their amyloids’ sticky tendrils to different use.
When paired with strong, porous carbon in a membrane, the lab-made amyloids successfully filtered over 99 percent of toxic materials out of solutions that mimicked severely polluted waters, the scientists report. The amyloids trapped particles of lead and mercury at a molecular site that is involved in turning the original milk protein into its pasty form. Radioactive waste particles also got tangled in the membranes. And the membranes snagged gold contaminants, which the team found could later be recovered and purified. A membrane with less than 6 milligrams of amyloids could trap 100 milligrams of gold, the scientists report.
The membranes could be developed for small- or large-scale water purification units, says study coauthor Raffaele Mezzenga, a physicist at ETH Zurich. Mezzenga estimates the technology would cost roughly one dollar per every thousand liters of water filtered. And a membrane can recover hundreds of times its own value in precious metals, Mezzenga says. The membrane design is simple and flexible, and could be adjusted to optimize cleanup or metal recovery, he says.
http://www.nature.com/nnano/journal/vaop/ncurrent/full/nnano.2015.3...

Comment by Dr. Krishna Kumari Challa on January 27, 2016 at 10:07am

Comment by Dr. Krishna Kumari Challa on January 27, 2016 at 9:04am

The editors of the leading medical journals around the world made a proposal recently that could change medical science forever. They said that researchers would have to publicly share the data gathered in their clinical studies as a condition of publishing the results in the journals. This idea is now out for public comment.

As it stands now, medical scientists can publish their findings without ever making available the data upon which their conclusions were based.

Only some of the top journals, such as The BMJ, have tried to make data sharing a condition of publication. But authors who didn't want to comply could just go elsewhere.

Think about it. The scientists who generate the data, with the participation of the people being studied and often with public funding, control it and most often don't share. By holding the data tight, researchers who ran a study are the only ones who can conduct additional analysis and studies.

If the proposed change is adopted it would make sharing more compelling. Inaccessible data is a problem rife throughout medical science. Industry traditionally held its data close — but so did academics.

These researchers have felt that they deserved the right to future papers for all their hard work gathering the original data. And maybe they didn't want others examining their work.

But this practice shields data from scrutiny. It forgoes an opportunity to crowdsource knowledge from scientists who weren't associated with the original study. It also violates the sensible practice of showing your work, not just the presumed answer.
The editors who made the proposal sought to be sensitive to the rights of researchers, funders and participants. But their intent is clear: It's time to share.
http://www.npr.org/sections/health-shots/2016/01/26/464010931/journ...

Comment by Dr. Krishna Kumari Challa on January 26, 2016 at 7:08am

How planet X was found...

Researchers inferred Planet X's presence from the peculiar clustering of six previously known objects that orbit beyond Neptune. 

They say there's only a 0.007% chance, or about one in 15,000, that the clustering could be a coincidence. 

Instead, they say, a planet with the mass of 10 Earths has shepherded the six objects into their strange elliptical orbits, tilted out of the plane of the solar system.

Comment by Dr. Krishna Kumari Challa on January 22, 2016 at 8:59am

When you see a bad moon rising, expect an ever-so-slightly wetter day. The lunar gravitational pull imperceptibly boosts rainfall when the moon is on the horizon and somewhat reduces rainfall when the moon is overhead or on the opposite side of the Earth, a new analysis of global rainfall concludes.

The cause is the atmospheric equivalent of ocean tides, researchers propose in a paper to be published in Geophysical Research Letters. Air gathers on Earth’s moon-facing side and on the opposite end of the globe. Scientists noticed that this pileup increases atmospheric pressure and predicted that atmospheric tides could alter precipitation rates as well. Scouring 15 years of global precipitation data, the researchers have discovered that the effect is present, but tiny: an approximately one micrometer per hour change in rainfall rate.
The moon’s gravitational pull, which is responsible for ocean tides, also creates atmospheric tides. As more air gathers during atmospheric high tide, atmospheric pressure increases. Satellites now offer global coverage of where and when rain falls.
The data revealed that during atmospheric high tide, rising air pressure slightly increases air temperature. That temperature boost allows the air to hold more water vapor, lowering the relative humidity and making rain less likely. During low tide, pressures drop slightly, cooling the air, raising the relative humidity and making rain more likely. This effect amounts to about a hundredth that of the typical background weather variability.
Understanding the lunar influence on rainfall won’t change how we predict the weather. The effect is so small that it quickly disappears into the background noise with time.
- Science News.Org

Comment by Dr. Krishna Kumari Challa on January 22, 2016 at 7:23am

Adding pollinators could boost small-farm yields
Analysis shows bees, bugs could significantly increase crop production in poor-performing farms.
Coaxing more bees, beetles and other pollinators to buzz around small fields could on average boost crop yields enough to close the gap between the worst and the best of these farms by almost a quarter, says agroecologist Lucas Alejandro Garibaldi of the National University of Río Negro and Argentina’s CONICET research network.
To see whether improving pollination could make a noticeable difference, Garibaldi and an international network of researchers carefully used the same sampling protocols to observe 344 fields on large and small farms in Africa, Asia and South America over the course of five years. Looking at 33 crops that need pollinators — raspberries, apples, coffee and so on — the researchers monitored pollinator visits and diversity as well as the ultimate yields.

The low-yielding farms on average produced only 47 percent of the yield that the best did, a notable gap. On the small operations, the sheer density of pollinators visiting crop flowers made a bigger difference in the amount of food produced, the researchers found. On larger farms, pollinator diversity mattered more: Those farms with a greater variety of pollinators produced more food.
Analyzing the way yields responded to the number of pollinators shows that improving pollination could help close the yield gap, Garibaldi and his colleagues say in the Jan. 22 Science.

Comment by Dr. Krishna Kumari Challa on January 20, 2016 at 9:09am

More than 90 percent of the heat trapped by greenhouse gas pollution since the 1970s has wound up in the oceans, and research published Monday revealed that a little more than a third of that seafaring heat has worked its way down to depths greater than 2,300 feet (700 meters).
Plunged to ocean depths by winds and currents, that trapped heat has eluded surface temperature measurements, fueling claims of a “hiatus” or “pause” in global warming from 1998 to 2013. But by expanding cool water, the deep-sea heat’s impacts have been indirectly visible in coastal regions by pushing up sea levels, contributing to worsening high-tide flooding.
The research, published in Nature Climate Change, was led by Lawrence Livermore National Laboratory.

http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2...

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