Comment

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...

Comment by Dr. Krishna Kumari Challa on January 20, 2016 at 8:14am

Q:How can we receive digital imagery of Pluto so quickly from across the solar system?

Answer: Pluto is about 4.9 billion kilometers away from earth. The digital imagery is transmitted via wireless communication, which is based on electromagnetic radiation which travels with light speed, e.g. about 300.000 kilometers per second in the vacuum of space. Which means signals need about 4 1/2 hours to earth. It takes additional time to actually transmit all the data, but probably not too much. Five hours all in all are enough.

Comment by Dr. Krishna Kumari Challa on January 16, 2016 at 7:21am

How can plants grow in space?

Yes, they have a problem in space...Zero Gravity!

The complication that needs to be overcome is that plants make use of gravity when planted to orient themselves (as they can't rely on being planted the right way up), so that their roots go down and their sprouts go up. Without gravity, they will tend to just stay at around the same depth and not sprout. One astronaut reported that this was simple enough to fix, however, just by plucking the ends out of the soil, pulling them to the surface, when they first sprout. From this point, the plant can orient itself using light and will continue to grow. Roots don't suffer as much, as they just grow away from the seed and avoid light (the surface), so develop relatively normally.

After this, growth is mostly normal. The resulting plants can look a little unusual because they don't have the usual drooping from gravity, so will tend to be more upright.
Crew members aboard the International Space Station have been growing  plants and vegetables for years in their "space garden." A space station study is helping investigators develop procedures and methods that allow astronauts to grow and safely eat space-grown vegetables.

Surprises in microgravity research are not unusual, though, and it turned out that overwatered traditional module sprouted and developed leaves about twice as fast.

The second surprising result was discovered when the root modules were unpacked on the ground. The new fertilizer being tested had a slower and more even release rate, which had helped lower the plants' accumulation of salts during ground studies. Investigators expected to see higher salt accumulation in the space modules, but the opposite occurred.

The current theory is that the extra water and larger plant uptake of fertilizer caused the root modules to remove nutrients faster and release fertilizer faster, thus preventing the salt accumulations that were observed in the slower-growing ground studies.

The space station's ability to provide on-the-spot adjustments to experiment conditions or opportunities to quickly repeat microgravity experiments with new conditions are a big plus for researchers.

Read more here:
Growing Plants and Vegetables in a Space Garden

• ‹ Previous
• 1
• …
• 852
• 853
• 854
• 855
• 856
• …
• 1043
• Next ›
• Page