Science Simplified!

Comment

Comment by Dr. Krishna Kumari Challa on April 19, 2016 at 6:41am

These trained African Giant Pouched Rats can detect TB in a short span of time! It takes about nine months to fully train a TB detection rat, but once trained they can screen thousands of sputum samples every month. The idea was spurred by the superb sense of smell of these rats which had been used to detect land mines after the Mozambican civil war.

The rats pick up in their smell a group of chemicals collectively called volatile organic compounds (VOCs) and the rats alert an observer that there are TB-associated VOCs in a sample.

The same principle has been used to develop machines called electronic noses.

Comment by Dr. Krishna Kumari Challa on April 18, 2016 at 7:07am

Why can anyone easily shot down a helicopter?
The reason they are so prone to being shot down according to experts is two fold... they rely on the tail rotor (or boom in the case of a NOTAR design) to produce the anti-torque to counter act the torque that needs to be applied to the main rotor. Take out that tail rotor and you can no longer power or even generate lift at all from the main rotor without spinning out of control (due to induced drag of the rotor blades). This is of course not applicable to co-axial helicopters which use two main rotor blades counter spinning to counteract torque. A shrouded tail rotor is less likely to strike objects and suffer catastrophic failure but is still susceptible to bullets and other projectiles hitting it. A NOTAR design using the Coanda effect has an extremely resilient anti torque mechanism but gives up maneuverability.

Secondly, the main rotor hub is an extremely complex piece of machinery. It must control collective pitch, cyclical pitch, spin extremely fast ( typically around 5 - 10 revs per second) which causing huge forces pulling it apart and essentially hold the weight plus maneuvering load of the helicopter. A great number of things can go wrong.

Losing power to the main rotor means certain death, but it is actually fairly easy to recover from and helicopter pilots actually practice it pretty regularly. They perform what's called an autorotation in which they immediately (upon sensing engine failure) lower the collective pitch to maintain rotor momentum, which will cause the helicopter to start to descent. They then push the nose forward to gain a forward momentum and start picking out a place to land (or crash depending on the rest of how the scenario plays out). The forward momentum allows the rotor to continue generating lift and the rotational momentum of the rotor will be used as a last second flare to slow descent and hopefully land smoothly. The most dangerous thing for a helicopter to do is to hover (no horizontal movement) at a low height above ground because there will be little that can be done to recover from a loss of power to the main rotor.

Also - 

1. They can't fly that fast, or at least not as fast as airplanes. This makes it easier to engage them with all kinds of AA weapons, even including small weapon fire.
2. They have to fly low, especially when they are supposed to give ground support, unload troop, or extract them from the battlefield. Once again, this makes them vulnerable to all kinds of weapons.
3. They have to be stationary during critical moments, such as unloading and loading personnel, or once again proving air support (sometimes). Not only are they easier to shoot at, but they also have less "energy" to perform evasive maneuvers, or get out of there.

To summarise it all together, helicopters have less "energy" when they are being shot at, in the sense that they are lower in altitude, and usually slower, if not standing perfectly still. This makes them vulnerable to small weapons fire, and basically does not allow the pilot to perform any kind of evasive maneuver.

Comment by Dr. Krishna Kumari Challa on April 16, 2016 at 10:02am

A new particle?!

Comment by Dr. Krishna Kumari Challa on April 15, 2016 at 7:27am

The sugar, cyclodextrin, removed cholesterol that had built up in the arteries of mice fed a high-fat diet, researchers report April 6 in Science Translational Medicine. The sugar enhances a natural cholesterol-removal process and persuades immune cells to soothe inflammation instead of provoking it, say immunologist Eicke Latz and colleagues.

Cyclodextrin, more formally known as 2-hydroxypropyl-beta-cyclodextrin, is the active ingredient in the air freshener Febreze. It is also used in a wide variety of drugs; it helps make hormones, antifungal chemicals, steroids and other compounds soluble. If the new results hold up in human studies, the sugar may also one day be used to liquefy cholesterol that clogs arteries.

Other researchers say the approach is promising, but must be tested in clinical trials. The sweet molecule is generally considered safe, but injecting it may raise the risk of liver damage or hearing loss.
http://stm.sciencemag.org/content/8/333/333ra50

Comment by Dr. Krishna Kumari Challa on April 13, 2016 at 6:38am

Plan to Send Probes to the Nearest Star
Funded by Russian entrepreneur Yuri Milner and with the blessing of Stephen Hawking, Breakthrough Starshot aims to send probes to Alpha Centauri in a generation
For Yuri Milner, the Russian Internet entrepreneur and billionaire philanthropist who funds the world’s richest science prizes and searches for extraterrestrial intelligence, the sky is not the limit—and neither is the solar system. Flanked by physicist Stephen Hawking and other high-profile supporters today in New York, Milner announced his most ambitious investment yet: $100 million toward a research program to send robotic probes to nearby stars within a generation.
- Scientific American

Comment by Dr. Krishna Kumari Challa on April 9, 2016 at 8:19am

Scientists blast comet-like ice with radiation like that in space, creating RNA - a key building block for life!
Scientists have produced the first formation of a key sugar required for life as we know it. By creating ices similar to those detected by the European Space Agency's Rosetta mission, which made the first landing on a comet, scientists were able to produce ribose, a sugar that serves as an important ingredient in RNA, an essential ingredient for life.
Cornelia Meinert, an associate scientist at the University Nice Sophia Antipolis led experiments that dosed icy materials produced in a laboratory with radiation similar to what comets would have received in the early life of the solar system, resulting in the creation of ribose.
Meinert and her colleagues recreated ices detected by Rosetta's Philae lander when it touched down on Comet 67P in 2014. In a lab, they created interstellar ices under what Meinert called "realistic astrophysical conditions" — in other words, within a vacuum, surrounded by low temperatures. Then, they blasted the samples with radiation simulating energy from the young sun, which was far more active than today's star, along with cosmic rays from the rest of the galaxy. Some of the material from the ices evaporated, while the leftover material created an organic residue. Sampling this residue revealed not only sugars but also amino acids, alcohols and other material.

The research was published online today (April 7) in the journal Science. - 
Source: http://www.space.com

Comment by Dr. Krishna Kumari Challa on April 9, 2016 at 7:20am

Melanesians are the only people known to have DNA from two ancient human ‘cousins’ - i.e., they got a double dose of Stone Age DNA!
Unlike people in the rest of world, some modern-day Pacific Islanders have inherited genes from two different groups of Stone Age relatives. That’s the conclusion of new research. And the ancient DNA they carry still affects their health and well-being — in a good way.

Melanesians live in a group of islands northeast of Papua New Guinea. Their ancestors mated with Neandertals, the new data show. They also mated with mysterious Neandertal relatives, known as Denisovans.

Population geneticist Benjamin Vernot and his colleagues made the discovery. At the time, Vernot was working at the University of Washington in Seattle. His group published its findings online March 17 in Science.

The new study looked at DNA that both parents pass to their children. (Other DNA is typically passed down only by moms.) As earlier studies had shown, non-African people have a little bit of Neandertal DNA.

This includes the Melanesians. On average, they inherited 1.5 to 4 percent of their DNA from Neandertals. But Melanesians have DNA from Denisovans too. This makes up 1.9 to 3.4 percent of their DNA, the new study finds. (Today’s Africans have little to no Neandertal or Denisovan DNA.)

In modern Melanesians, the bits of Neandertal and Denisovan DNA include genes involved in metabolism and immunity. That means mating with other hominids — other species of human ancestors — may have helped ancient humans thrive, the scientists say.

Comment by Dr. Krishna Kumari Challa on April 8, 2016 at 8:52am

Stop wasting food to manage climate change to good levels - scientists

Reducing food waste around the world would help curb emissions of planet-warming gases, lessening some of the impacts of climate change such as more extreme weather and rising seas, scientists said on 7th April, 2016.
Up to 14 percent of emissions from agriculture in 2050 could be avoided by managing food use and distribution better, according to a new study from the Potsdam Institute for Climate Impact Research (PIK).
"Agriculture is a major driver of climate change, accounting for more than 20 percent of overall global greenhouse gas emissions in 2010".
"Avoiding food loss and waste would therefore avoid unnecessary greenhouse gas emissions and help mitigate climate change."
Between 30 and 40 percent of food produced around the world is never eaten, because it is spoiled after harvest and during transportation, or thrown away by shops and consumers.
The share of food wasted is expected to increase drastically if emerging economies like China and India adopt Western food habits, including a shift to eating more meat, the researchers warned.
Richer countries tend to consume more food than is healthy or simply waste it, they noted.

Food loss and waste hurts people, costs money and harms the planet. Cutting (it) is a no-brainer, according to these scientists.

Comment by Dr. Krishna Kumari Challa on April 7, 2016 at 7:31am

New state of matter detected in a two-dimensional material

A team of quantum physicists has discovered a mysterious new state of matter in a two-dimensional material. Scientists are calling the state "quantum spin liquid."

The novel state was predicted 40 years ago. Now, researchers have direct evidence.

Quantum spin liquid is characterized by the breaking apart of electrons. The electron fragments are called Majorana fermions. While observing particle behavior inside a graphene-like 2D material, scientists at the University of Cambridge recorded the signatures of these fractional particles.

What they saw matched the predictions of theoretical models for a quantum spin liquid.

The mysterious state explains anomalies inside magnetic materials. Electrons in magnetic materials each behave like miniature bar magnets. As a material is cooled, the electrons each line up in accordance with magnetic north -- all pointing the same direction.

This doesn't happen in magnetic materials boasting quantum spin liquid, where electrons refuse to align. Instead, their quantum fluctuations result in a soup of entangled electrons.
This is a new addition to a short list of known quantum states of matter.
http://www.nature.com/nmat/journal/vaop/ncurrent/full/nmat4604.html

Comment by Dr. Krishna Kumari Challa on April 6, 2016 at 6:25am

How scientists can reduce their carbon footprint
Cutting down on long-distance air travel is the best way to reduce the emission of greenhouse gases by the scientific community.
http://elifesciences.org/content/5/e15928v1?utm_source=content_aler...

• ‹ Previous
• 1
• …
• 947
• 948
• 949
• 950
• 951
• …
• 1145
• Next ›
• Page