Science Simplified!

Comment

Comment by Dr. Krishna Kumari Challa on July 9, 2016 at 5:52am

Big Bang or Big Bounce?

Perfect Quantum Cosmological Bounce

A new study of the early universe reveals how it could have been formed from an older collapsing universe, rather than being brand new.

The universe is currently expanding and it is a common theory that this is the result of the 'Big Bang' - the universe bursting into existence from a point of infinitely dense and hot material.

However, physicists have long debated this idea as it means the universe began in a state of complete breakdown of physics as we know it. Instead, some have suggested that the universe has alternated between periods of expansion and contraction, and the current expansion is just one phase of this.

This so-called 'Big Bounce' idea has been around since 1922, but has been held back by an inability to explain how the universe transitions from a contracting to an expanding state, and vice versa, without leading to an infinite point.

Now, in a new study published today in Physical Review Letters, Dr Steffen Gielen from Imperial College London and Dr Neil Turok, Director of the Perimeter Institute for Theoretical Physics in Canada, have shown how the Big Bounce might be possible.

Cosmological observations suggest that during its very early life, the universe may have looked the same at all scales - meaning that the physical laws that that worked for the whole structure of the universe also worked at the scale of the very small, smaller than individual atoms. This phenomenon is known as conformal symmetry.

In today's universe, this is not the case - particles smaller than atoms behave very differently to larger matter and the symmetry is broken. Subatomic particle behaviour is governed by what is called quantum mechanics, which produces different rules of physics for the very small.

For example, without quantum mechanics, atoms would not exist. The electrons, as they whizz around the nucleus, would lose energy and collapse into the centre, destroying the atom. However, quantum mechanics prevents this from happening.

In the early universe, as everything was incredibly small, it may have been governed solely by the principles of quantum mechanics, rather than the large-scale physics we also see today.

In the new study, the researchers suggest that the effects of quantum mechanics could prevent the universe from collapsing and destroying itself at end of a period of contraction, known as the Big Crunch. Instead, the universe would transition from a contracting state to an expanding one without collapsing completely.

http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.117.021301

Comment by Dr. Krishna Kumari Challa on July 9, 2016 at 5:38am

Viral hepatitis kills as many as malaria, TB or HIV/AIDS, finds study
Viral hepatitis has become one of the leading causes of death and disability across the globe – killing at least as many people annually as TB, malaria or HIV/AIDS. This is the finding of new research from scientists at Imperial College London and University of Washington, who analysed data from 183 countries collected between 1990 and 2013.


Viral hepatitis exists in five forms – A, B, C, D and E and is transmitted through bodily fluids, or, in the case of A and E, through food or drink contaminated with faeces.

A majority of the deaths – 96 per cent - were due to hepatitis B and C which cause liver damage (cirrhosis), and liver cancer. Symptoms include fatigue, jaundice and nausea, however in many people the infection is symptomless - and so an individual may not know they are infected until they develop serious complications.

The researchers, who published their findings in journal The Lancet, found that viral hepatitis deaths increased by 63 per cent over the 23-year period. The study, which was co-led by scientists at the Institute for Health Metrics and Evaluation at the University of Washington, found deaths from viral hepatitis were higher in high and middle-income countries than lower income countries. The authors say the overall disease burden is now more evenly divided between higher and lower income nations.
The team say we now urgently need international measures to address this crisis.
Although there are effective treatments and vaccines for viral hepatitis, there is very little money invested in getting these to patients –especially compared to malaria, HIV/AIDS and TB. We now have a viral hepatitis global action plan approved in May by the World Health Assembly, and we now need to implement it.
The researchers found deaths from acute infection, cirrhosis and liver disease caused by viral hepatitis had increased by 63 per cent from 890,000 in 1990 to 1.45 million in 2013.

By comparison, in 2013, 1.3 million people worldwide died from AIDS, 1.4 million from TB, and 855,000 from malaria, according to a 2015 study by the Institute for Health Metrics and Evaluation.
In the current study, most hepatitis deaths were found to occur in East Asia, and the majority of global deaths were due to hepatitis B and C. One potential reason for the high number of deaths from hepatitis B and C is these strains cause long-term infections with very few immediate symptoms. They can therefore progress silently until they trigger serious liver damage or cancer. Although we have had an effective hepatitis B vaccine for some years, there is still a large proportion of the world which is unvaccinated. We have no similar vaccine for hepatitis C.

Source: Imperial College London

Comment by Dr. Krishna Kumari Challa on July 5, 2016 at 7:10am

Soy diesel found to be less toxic than other fuels
Unlike conventional diesel, fuel made from soybeans does not directly damage lung cells, a lab study has shown.

“Some of the soybean biodiesel presently being used in Brazil does not exhibit direct adverse effects on human lung cells nor [does it] induce inflammatory response,” says the paper, published in the August issue of the journal Toxicology in Vitro.

To assess the fuels’ toxic effects, researchers from Brazil and Puerto Rico exposed lung cell cultures to particles emitted by the combustion of four types of fuel: commercial diesel from fossil fuel sources, pure soy-based biodiesel, soy-based biodiesel with additives and ethanol with additives.

After exposure, the scientists counted the proportion of cells that survived to assess the fuels’ toxicity, and measured the quantity of cytokines the cells produced. Cytokines are proteins secreted by certain cells, including lung cells, involved in the regulation of inflammatory processes. An increase in their production can cause damage to the cells.

Adriana Gioda, a chemist at the Pontifical Catholic University of Rio de Janeiro in Brazil and co-author of the paper, says this study is the first demonstration that soy-based biodiesel does not cause a significant toxic reaction in lung cells.

However, the authors warn that these results should not be “considered as an absolute positive outcome” and should pave the way for further studies in live animals.
 

Comment by Dr. Krishna Kumari Challa on July 5, 2016 at 6:50am

Monsoon forecast is becoming a difficult process. With more than 70% of India’s 1.25 billion citizens engaged in agriculture and relying on weather predictions to decide when they will sow their seeds and harvest their crops.
But getting the forecast right remains a challenge, thanks to the complex — and still poorly understood — ways in which South Asia’s monsoon rains are influenced by everything from atmospheric and ocean temperatures to air quality and global climate trends. Even the amount of ice in Antarctica is suspected to have an impact.

And it’s only getting harder to figure out, scientists say, as the monsoon becomes increasingly erratic.

A new study released Friday in the journal Science Advances helps clear up a bit of the mystery, by showing that man-made climate change is responsible for most of the change seen in ocean surface temperatures near the equator across Asia, which in turn affect regional rainfall patterns including the Indian monsoon.

By showing that link, the study indicates future ocean warming in the region, which could in turn increase the amount of rainfall during monsoons, strengthen cyclones and increase precipitation over East Asia.

“This has important implications for understanding changes in rainfall patterns for a large, and vulnerable population across Asia,” said oceanographer Evan Weller, who led the research team while he was at Pohang University of Science and Technology in South Korea, before recently shifting to Monash University in Australia.

The study looks specifically at a mid-oceanic body called the Indo-Pacific Warm Pool, which holds some of the world’s warmest seawaters and spans the western Pacific to the eastern Indian Ocean.

Scientists have long known that India’s monsoons are partly influenced by that warm pool. And they’ve known that the pool has been expanding — and warming — for decades. That expansion and warming have already caused some sea rise around islands in Asia.

It wasn’t entirely clear why the pool was changing, until now.

Weller and his team compared data observations with several climate models, and deduced that rising greenhouse gases along with aerosols and other atmospheric pollutants were the dominant cause of the pool’s warming and expansion over the past 60 years, though regional climate variations also had some effect.

But one thing is clear: If climate change trends continue, and by most indications they will, forecasters will have to consider the warm pool in their monsoon predictions. And by demonstrating how greenhouse gases are the dominant driver of changes in the warm pool, the team has added another dimension that can help improve climate models.

Comment by Dr. Krishna Kumari Challa on July 2, 2016 at 8:45am

Bacteria block mosquitoes from transmitting Zika, chikungunya viruses!
Researchers at the University of Wisconsin-Madison have confirmed that a benign bacterium called Wolbachia pipientis can completely block transmission of Zika virus in Aedes aegypti, the mosquito species responsible for passing the virus to humans.

Matthew Aliota, a scientist at the UW-Madison School of Veterinary Medicine (SVM) and first author of the paper -- published today (July 1, 2016) in the journal Scientific Reports -- says the bacteria could present a "novel biological control mechanism," aiding efforts to stop the spread of Zika virus.
Researchers led by Jorge Osorio, a UW-Madison professor of pathobiological sciences, and Scott O'Neill of the the Eliminate Dengue Program (EDP) and Monash University in Melbourne, Australia, are already releasing mosquitoes harboring the Wolbachia bacterium in pilot studies in Colombia, Brazil, Australia, Vietnam and Indonesia to help control the spread of dengue virus. Their work is supported by the Bill and Melinda Gates Foundation.

An important feature of Wolbachia is that it is self-sustainable, making it a very low-cost approach for controlling mosquito-borne viral diseases that are affecting many tropical countries around the world.

In two of researchers initial study sites in Australia, approximately 90 percent of the mosquitoes continue to be infected with Wolbachia after initial release more than six years ago.
Wolbachia can be found in up to 60 percent of insects around the world, including butterflies and bees. While not typically found in the Aedes aegypti mosquito -- the species that also transmits dengue, chikungunya and yellow fever viruses -- scientists discovered in the early 1990s that Wolbachia could be introduced to the mosquito in the lab and would prevent the mosquitoes from transmitting dengue virus.

Zika virus belongs to the same family as dengue virus and Aliota and Osorio.

Comment by Dr. Krishna Kumari Challa on July 2, 2016 at 7:21am

Comment by Dr. Krishna Kumari Challa on July 2, 2016 at 6:17am

Good News: Ozone hole in Antarctica is recovering!

Global regulation of chlorine compounds is giving the atmosphere time to heal, even as volcanic eruptions interfere.

A new analysis shows that, on average, the hole — which forms every Southern Hemisphere spring, letting in dangerous ultraviolet light — is smaller and appears later in the year than it did in 2000.

The 1987 global treaty called the Montreal Protocol sought to reduce the ozone hole by banning chlorofluorocarbons, chlorine-containing chemicals — used as refrigerants in products such as air conditioners — that accelerated ozone loss in the stratosphere. The study shows that it worked.

The finding was reported on June 30th in Science.

--

STING Operation Against Pathogens Researchers have shed light on how STING, an innate immune sensor that triggers inflammation, is activated to eliminate viruses or bacteria. 

Researchers at the University of Tokyo have revealed the mechanism underlying the activation of STING, an innate immune sensor that triggers inflammation to remove foreign pathogens. This discovery, published in Nature Communications, provides therapeutic targets for treating infections and inflammatory diseases. When cells are infected with foreign matter such as DNA viruses or bacteria, the foreign DNA is sensed by STING, which is embedded in the membrane of the endoplasmic reticulum (ER), an important site of protein production in a cell. STING then triggers the release of type I interferon and other inflammatory responses to eliminate the foreign substance. This essential basic cellular response is part of the innate immune system that recognizes and eliminates pathogens from our bodies. However, it was unclear why STING responded to foreign DNA. Additionally, although it is known that STING translocates from the ER to a location close to the nucleus when it detects foreign DNA, the role of this translocation remained unknown. In the present study, the research group of Assistant Professor Kojiro Mukai, Associate Professor Tomohiko Taguchi and Professor Hiroyuki Arai at the University of Tokyo Graduate School of Pharmaceutical Sciences found that STING is activated at the Golgi, a part of the cell that is involved in protein transport, as opposed to the ER. Furthermore, the activation of STING requires palmitoylation, a type of protein modification, at the Golgi. The unique lipid environment of the Golgi is also essential for the activation of STING. In various inflammatory diseases such as autoimmune disease and cancer, STING is often activated, causing an abnormal inflammatory response. Thus, the findings offer new opportunities to treat such diseases by suppressing the palmitoylation of STING or the manipulation of the Golgi lipid composition.

http://www.nature.com/ncomms/2016/160621/ncomms11932/full/ncomms119...

Comment by Dr. Krishna Kumari Challa on June 30, 2016 at 6:49am

Life-saving news: New Helium deposits found in Tanzania

Using a new technique, scientists have discovered reserves of helium in Tanzania said to be equivalent to seven times the amount of the noble gas consumed worldwide each year. The new source could alleviate recurrent shortages of helium that have plagued users of scientific instruments and medical imaging equipment.

Working with the start-up firm Helium One, scientists at Oxford and Durham universities uncovered the reserves in Tanzania’s East African Rift Valley. The researchers theorize that intense heat from volcanic activity in the Rift Valley releases helium in ancient crustal rock. The gas then accumulated in underground reservoirs.

The scientist say they have combined methods used in oil exploration with seismic images of gas-trapping structures and calculations from independent experts to estimate helium reserves of 1.5 billion m3 in just one part of the Rift Valley.

Today, helium is recovered as a by-product of natural gas extraction. But with prices of helium now about four times higher than they were a decade ago, prospectors are looking for new sources. The Tanzania helium reserve would be the first to be discovered and developed intentionally

The scientists presented the findings on June 28 at the Goldschmidt Conference, a gathering of geochemistry experts in Yokohama, Japan.

- Chemical and Engineering News

Comment by Dr. Krishna Kumari Challa on June 27, 2016 at 5:02am

Warning: Looking at your smartphone while lying in bed at night could wreak havoc on your vision.
Two women went temporarily blind from constantly checking their phones in the dark, say doctors who are now alerting others to the unusual phenomenon.
The solution: Make sure to use both eyes when looking at your smartphone screen in the dark.
In Thursday's New England Journal of Medicine, doctors detailed the cases of the two women, ages 22 and 40, who experienced "transient smartphone blindness" for months.
The women complained of recurring episodes of temporary vision loss for up to 15 minutes. They were subjected to variety of medical exams, MRI scans and heart tests. Yet doctors couldn't find anything wrong with them to explain the problem.
But minutes after walking into an eye specialist's office, the mystery was solved.
"I simply asked them, 'What exactly were you doing when this happened?'" recalled Dr. Gordon Plant of Moorfield's Eye Hospital in London.
He explained that both women typically looked at their smartphones with only one eye while resting on their side in bed in the dark—their other eye was covered by the pillow.
"So you have one eye adapted to the light because it's looking at the phone and the other eye is adapted to the dark," he said.
When they put their phone down, they couldn't see with the phone eye. That's because "it's taking many minutes to catch up to the other eye that's adapted to the dark," Plant said.
He said the temporary blindness was ultimately harmless, and easily avoidable, if people stuck to looking at their smartphones with both eyes.
One of the women was relieved the short-term blindness didn't signal a more serious problem like an imminent stroke. He said the second woman was more skeptical and kept a rigorous monthslong diary tracking her fleeting vision loss before she finally believed him. But she couldn't stop checking her phone for messages from bed, he said.
Dr. Rahul Khurana, a spokesman for the American Academy of Ophthalmology, called it a fascinating hypothesis but said two cases weren't enough to prove that one-eyed smartphone use in the dark caused the problem. He also doubted whether many smartphone users would experience the phenomenon.
Khurana, who acknowledged that he's an avid cellphone user, said that he and his wife tried to recreate the scenario on a recent evening, but had difficulty checking their phones with only one eye. "It was very odd," he said.
Source: New England Journal of Medicine

Comment by Dr. Krishna Kumari Challa on June 24, 2016 at 5:27am

New Way To Create Fuel From Waste Plastics
Scientists have found a way to use plastic trash to create a cleaner diesel-like fuel that could power vehicles, an advance that may turn landfills into potential energy sources in future.

The researchers from the Chinese Academy of Sciences and University of California in the US hope to scale up the technique to allow for it to be used in actually reducing plastic trash.

Plastics break down very slowly causing them to pile up in landfills and serving as the source material in artificial island creation in oceans.

Scientists have been looking for ways to degrade plastics, particularly polyethylene, the most common kind produced, but until now have not been able to find inexpensive and scalable means.

The new method involves mixing the plastics with an organometallic catalyst, made from readily available molecules that were then doped with metal iridium, 'Phys.org' reported.

The reaction caused the bonds holding the plastic together to weaken, allowing them to be more easily torn apart.

Researchers were able to use the broken down material to create a diesel-like fuel which they claim could be used to power vehicles and other motors.

Burning the fuel is also cleaner than burning other combustible materials, they said.

The research was published in the journal Science Advances.

• ‹ Previous
• 1
• …
• 639
• 640
• 641
• 642
• 643
• …
• 842
• Next ›
• Page