Comment

Comment by Dr. Krishna Kumari Challa on June 1, 2017 at 5:08am

We all know that light travels faster than sound. That is why we see lightening first and then hear the sound of thunder later. Light travels roughly 800,000 times as fast as sound.

But an interesting thing about meteors is you can hear the sound and see their light at the same time! How is this possible? Now scientists explained the mystery...

The sound waves aren’t coming from the meteor itself, atmospheric scientists Michael Kelley of Cornell University and Colin Price of Tel Aviv University propose April 16 in Geophysical Research Letters. As the leading edge of the falling space rock vaporizes, it becomes electrically charged. The charged head produces an electric field, which yields an electric current that blasts radio waves toward the ground. As a type of electromagnetic radiation, radio waves travel at the speed of light and can interact with metal objects near the ground, generating a whistling sound that people can hear.

Just 0.1 percent of the radio wave energy needs to be converted into sound for the noise to be audible as the meteor zips by, the researchers estimate. This same process could explain mysterious noises heard during the aurora borealis, or northern lights. Like meteors, auroras have been known to emit radio wave bursts.

On the electrophonic generation of audio frequency sound by meteors

 http://onlinelibrary.wiley.com/doi/10.1002/2017GL072911/abstract

Comment by Dr. Krishna Kumari Challa on May 24, 2017 at 7:07am

Do statins help you avoid heart attacks and strokes? That depends on various things says a recent study

The benefits of statins for people older than 75 remain unclear, a new analysis finds. Statins did not reduce heart attacks or coronary heart disease deat... from any cause, compared with people not taking statins, researchers report online May 22 in JAMA Internal Medicine.

Recently published guidelines cited insufficient data to recommend statins for people older than age 75 who don’t have a history of cardiovascular disease. The new analysis considered a subset of older adults enrolled in a study of heart attack prevention and mortality conducted from 1994 to 2002. The sample included 2,867 adults ages 65 and older who had hypertension, 1,467 of whom took a statin.

There was no meaningful difference in the frequency of heart attacks or coronary heart disease deaths between those who took statins and those who did not. There was also no significant difference in deaths from any cause, both overall and among participants ages 65 to 74 or those 75 and older.

Statin use may be associated with muscle damage and fatigue, which could especially impact older adults and put them at higher risk for physical decline, the authors say.

Science news

Comment by Dr. Krishna Kumari Challa on May 10, 2017 at 9:10am

Smile and the world thinks you are older! Don't believe? here is the proof!

A new study shows that smiling can make you appear to be two years older than if you wear a poker face. And if you reacted to that finding with a look of surprise - well, that expression might just have dropped years from your visage.

"We associate smiling with positive values and youth," said study co-author Melvyn Goodale, director of the Brain and Mind Institute at Western University. "Think of all the skin-care and toothpaste companies that sell the same idea every day."

But this study -- in which researchers flashed images of people with smiling, neutral and surprised expressions -- showed the opposite: participants perceived the surprised faces as the youngest and smiling faces the oldest.

"The striking thing was that when we asked participants afterwards about their perceptions, they erroneously recalled that they had identified smiling faces as the youngest ones," Goodale said. "They were completely blind to the fact they had 'aged' the happy-looking faces. Their perceptions and their beliefs were polar opposites."

Goodale said the aging effect of a smile stems from people's inability to ignore the wrinkles that form around the eyes during smiling. A look of surprise, on the other hand, smooths any wrinkles.

"It may seem counter-intuitive, but the study shows that people can sincerely believe one thing and then behave in a completely different way," Goodale said.

The study, "The effects of smiling on perceived age defy belief" is newly published in the journal Psychonomic Bulletin and Review. 

source: Eurekalert

Comment by Dr. Krishna Kumari Challa on May 9, 2017 at 8:39am

Inhaled Nanoparticles Accumulate at Sites of Vascular Disease

Inhaled nanoparticles can cross the lungs, entering the bloodstream, and accumulate in blood vessels and other bodily sites vulnerable to cardiovascular disease, a new study suggests. 
 
People around the world are constantly exposed to nanoparticles mostly emitted by vehicle exhaust, but the risks are greater in crowded Asian cities, which are seeing a dramatic rise in the number of vehicles on the roads.
 
In the study — the results of which were published on 26 April in ACS Nano — it was shown that healthy volunteers exposed to gold nanoparticles retained them in the body for as long as three months. Experiments on mice also reveal that nanoparticles accumulate in the liver and blood vessels.
 
Results from human studies have been inconsistent thus far, the authors write. But evidence showing that nanoparticles enter the blood circulation by escaping the lungs “provides a direct mechanism that can explain the link between environmental nanoparticles and cardiovascular disease”. It also has implications for managing potential risks of engineered nanoparticles, they add.
 
The link between environmental nanoparticles and cardiovascular disease could be explained by gold particles detected in surgical specimens of diseased carotid artery from patients at risk of stroke and at sites of vascular inflammation, according to the study.

http://pubs.acs.org/doi/abs/10.1021/acsnano.6b08551

Comment by Dr. Krishna Kumari Challa on May 9, 2017 at 7:23am

Some farming practices destroy Earthworms...

The digging, stirring and overturning of soil by conventional ploughing in tillage farming is severely damaging earthworm populations around the world, say scientists.

The findings published in the scientific journal Global Change Biology show a systematic decline in earthworm populations in soils that are ploughed every year. The deeper the soil is disturbed the more harmful it is for the earthworms.

The scientists from the University of Vigo, Spain, and University College Dublin, Ireland, analysed 215 field studies from across 40 countries dating back as far as 1950. Each of the studies investigated earthworm populations under conventional tillage and other forms of reduced tillage.

According to the findings, the earthworm populations most vulnerable to tillage are larger earthworms that move between layers of soil and create permanent burrows between them (anecic earthworms). Small earthworms that live in the top layers of soil and convert debris to topsoil (epigeic earthworms) were also found to be highly susceptible.

Farming practices that involve no-tillage, Conservation Agriculture and shallow non-inversion tillage were shown to significantly increase earthworm populations. The scientists note that these reduced tillage practices are increasingly being adopted world-wide due to their environmental benefits in terms of erosion control and soil protection.

Conventional tillage decreases the abundance and biomass of earthworms and alters their community structure in a global meta-analysis

http://onlinelibrary.wiley.com/doi/10.1111/gcb.13744/abstract;jsess...

Comment by Dr. Krishna Kumari Challa on May 9, 2017 at 7:07am

Some farming practices destroy Earthworms...

The digging, stirring and overturning of soil by conventional ploughing in tillage farming is severely damaging earthworm populations around the world, say scientists.

The findings published in the scientific journal Global Change Biology show a systematic decline in earthworm populations in soils that are ploughed every year. The deeper the soil is disturbed the more harmful it is for the earthworms.

The scientists from the University of Vigo, Spain, and University College Dublin, Ireland, analysed 215 field studies from across 40 countries dating back as far as 1950. Each of the studies investigated earthworm populations under conventional tillage and other forms of reduced tillage.

According to the findings, the earthworm populations most vulnerable to tillage are larger earthworms that move between layers of soil and create permanent burrows between them (anecic earthworms). Small earthworms that live in the top layers of soil and convert debris to topsoil (epigeic earthworms) were also found to be highly susceptible.

Farming practices that involve no-tillage, Conservation Agriculture and shallow non-inversion tillage were shown to significantly increase earthworm populations. The scientists note that these reduced tillage practices are increasingly being adopted world-wide due to their environmental benefits in terms of erosion control and soil protection.

Conventional tillage decreases the abundance and biomass of earthworms and alters their community structure in a global meta-analysis

http://onlinelibrary.wiley.com/doi/10.1111/gcb.13744/abstract;jsess...

Comment by Dr. Krishna Kumari Challa on May 5, 2017 at 8:48am

Smell sensors that diagnose diseases

Each of us has a unique "odourprint" made up of thousands of organic compounds. These molecules offer a whiff of who we are, revealing age, genetics, lifestyle, hometown — even metabolic processes that underlie our health. Yes, the smell of someone's skin, breath and bodily fluids can be suggestive of illness. The breath of diabetics sometimes smells of rotten apples, experts report; the skin of typhoid patients, like baking bread. Now, researchers are trying to build an inexpensive odor sensor for quick, reliable and noninvasive diagnoses. The field finally seems on the cusp of succeeding.

Britain's National Health Service is paying for a 3,000-subject clinical trial to test an odor analysis sensor's ability to diagnose lung cancer. The company that makes the unit says clinicians can change the software to sniff out other diseases.

A similar diagnostic technology is being developed in Israel. Those researchers published a paper in ACS Nano in December showing that their artificially intelligent nano-array could distinguish among 17 diseases with up to 86 percent accuracy.

In addition to these groups, teams in the United States, Austria, Switzerland and Japan also are developing odor sensors to diagnose disease.

--

Artificial blood made safer...

Bioinspired Polydopamine-Coated Hemoglobin as Potential Oxygen Carrier with Antioxidant Properties

http://pubs.acs.org/doi/abs/10.1021/acs.biomac.7b00077

n a study published in Biomacromolecules, researchers describe a promising blood substitute that could effectively carry oxygen and also scavenge for potentially damaging free radicals. Blood transfusions can save the lives of patients who have suffered major blood loss, but hospitals don't always have enough or the right type on hand. Red blood cells carry the protein hemoglobin, which performs the essential function of delivering oxygen to the body's tissues. Scientists have tried developing chemically modified hemoglobin—which by itself is toxic—as a blood substitute but have found that it forms methemoglobin. This form of the protein doesn't bind oxygen and thus decreases the amount of oxygen that blood delivers in the body. In addition, the generation of methemoglobin produces hydrogen peroxide, which leads to cell damage. In the present study, a team of researchers led by Dr. Wang Quan from the Beijing Institute of Transfusion Medicine wanted to see if packaging hemoglobin in a benign envelope could get around these problems. The researchers developed a one-step method for wrapping hemoglobin in polydopamine, or PDA, which has been widely studied for biomedical applications. A battery of lab tests showed that the PDA-coated hemoglobin effectively carried oxygen, while preventing the formation of methemoglobin and hydrogen peroxide. In addition, it caused minimal cell damage, and acted as an effective antioxidant, scavenging for potentially damaging free radicals and reactive oxygen species.

Comment by Dr. Krishna Kumari Challa on May 3, 2017 at 9:24am

Comment by Dr. Krishna Kumari Challa on April 29, 2017 at 7:34am

Scientists have found a way to trigger artificial photosynthesis, turning greenhouse gases such as carbon dioxide into clean air and producing energy at the same time.

The research team  from University of Central Florida (UCF) in the US created a way to trigger a chemical reaction in a synthetic material called metal-organic frameworks (MOF) that breaks down carbon dioxide into harmless organic materials.

The process is similar to photosynthesis in which plants convert carbon dioxide (CO2) and sunlight into food. However, instead of producing food, the new method produces solar fuel.

The chemical reaction is triggered by blue light mimicking the blue wavelength of sunlight, and converts carbon dioxide into two reduced forms, formate and formamides, which can be used as energy sources.

The findings were published in the Journal of Materials Chemistry A.

Comment by Dr. Krishna Kumari Challa on April 27, 2017 at 6:29am

Indian space agency ISRO  is seeking proposals  for space-based experiments to study Venus.

The Announcement of Opportunity (AO) is for space experiments by institutions in the country, and the last date for receiving the proposals is May 19, 2017, the Bengaluru- headquartered Indian Space Research Organisation (ISRO) said.

Those sending the proposals for Venus orbiter mission may be currently involved in planetary exploration studies, or development of science instruments for space, or willing to develop the experiments.

Find more details here: http://www.isro.gov.in/announcement-of-opportunity-ao-space-based-e...

• ‹ Previous
• 1
• …
• 837
• 838
• 839
• 840
• 841
• …
• 1053
• Next ›
• Page