Science Simplified!

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Comment by Dr. Krishna Kumari Challa on March 21, 2016 at 9:28am

A parallel realm of carbon-polluting activity - ranging from email exchanges to social network chatter (tweets, posts etc) to streaming movies on smartphones - has slipped largely unnoticed under the climate change radar. In isolation, these discrete units of our virtual existence seem weightless and without cost.
A short email, for example, is estimated to add about four grams of CO2-equivalent (CO2e) into the atmosphere.
By comparison, humanity emits some 40 billion tonnes of CO2 every year.
But as the digital era deepens, the accumulated volume of virtual messages has become a significant part of humanity's carbon footprint.
"Electricity consumption related to the growth of digital technologies is exploding," notes Alain Anglade of the French Environment and Energy Management Agency. In France it already accounts for more than 10% of total electricity use, he said, a percentage that holds for many developed countries. To see the big picture, it helps to break it down.
Sending five dozen of those four-gram emails in a day from your smartphone or laptop, for example, is the equivalent of driving an average-size car a kilometre. AFP

Comment by Dr. Krishna Kumari Challa on March 18, 2016 at 10:58am

Using flashes of blue light, scientists have pulled forgotten memories out of the foggy brains of mice engineered to have signs of early Alzheimer’s disease. This memory rehab feat, described online March 16 in Nature, offers new clues about how the brain handles memories, and how that process can go awry.
To recover a lost memory, scientists first had to mark it. Neuroscientist Susumu Tonegawa of MIT and colleagues devised a system that tagged the specific nerve cells that stored a memory — in this case, an association between a particular cage and a shock. A virus delivered a gene for a protein that allowed researchers to control this collection of memory-holding nerve cells. The genetic tweak caused these cells to fire off signals in response to blue laser light, letting Tonegawa and colleagues call up the memory with light delivered by an optic fiber implanted in the brain.

A day after receiving a shock in a particular cage, mice carrying two genes associated with Alzheimer’s seemed to have forgotten their ordeal; when put back in that cage, these mice didn’t seem as frightened as mice without the Alzheimer’s-related genes. But when the researchers used light to restore this frightening memory, it caused the mice to freeze in place in a different cage. (Freezing in a new venue showed that laser activation of the memory cells, and not environmental cues, caused the fear reaction.)

The fact that this memory could be pulled out with light helps clarify the source of memory trouble for people with Alzheimer’s. People in the early stages of the disease seem able to create new memories, but then rapidly forget them, he says. Memories can sometimes be strengthened with reminders and clues from the environment, suggesting that they are “somewhere in there,” but not retrievable.
Further experiments with the mice showed that the fear memory could be strengthened by forcing it to appear multiple times. This memory boot camp worked because it boosted the number of docking sites on memory-holding nerve cells in the mice with Alzheimer’s-related genes. Usually, these docking sites — knobs called dendritic spines that receive messages from other nerve cells — become scarcer with age. To counter that, Tonegawa and colleagues used light to repeatedly activate nerve cells that in turn activate the memory-holding cells. Compared with mice that didn’t get this strengthening treatment, mice with the Alzheimer’s genes that underwent this process were more fearful of the cage where they had received a shock, even six days later.
The results are only experimental but several insights have been gained on how memory works.

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature17172...

Comment by Dr. Krishna Kumari Challa on March 16, 2016 at 9:03am

Comment by Dr. Krishna Kumari Challa on March 15, 2016 at 8:13am

Comment by Dr. Krishna Kumari Challa on March 12, 2016 at 9:33am

An Australian artist is the only confirmed tetrachromat in the world.

What does tetrachromat mean?

The human eye is packed with millions of cone-shaped cells that allow for color to be perceived. For those with normal vision, the three types of cones allow vision of about one million distinctive colors. Some animal species including certain birds, insects, fish, and reptiles, have a fourth type of cone cell that extends color perception into the UV range. Though evolution has mostly scrubbed that fourth cone from the mammalian lineage, there is evidence that a small group of humans may have a genetic variant that allows for tetrachromacy.

So, a tetrachromat would be able to see, roughly 100 times more colours than the average human!!

Quoting Concetta, "It’s shocking to me how little color people are seeing."

The fact she is the only person (or one of a few) who sees the world totally differently makes her amazingperson. When she looks at a leaf, she sees much more than just green. “Around the edge I’ll see orange or red or purple in the shadow; you might see dark green but I’ll see violet, turquoise, blue,” she said. “It’s like a mosaic of color.”
She paints what she sees exactly. http://concettaantico.com/

where Concetta shows the world what she sees.

She conjures masterpieces in one sitting. All her paintings are insanely colorful,and feature shades you wouldn't expect to see."
The fact that we may never be able to see the world the way she does is saddening in a way.

Tetrachromacy is the condition of possessing four independent channels for conveying color information, or possessing four types of cone cells in the eye. Organisms with tetrachromacy are called tetrachromats.

In tetrachromatic organisms, the sensory color space is four-dimensional, meaning that to match the sensory effect of arbitrarily chosen spectra of light within their visible spectrum requires mixtures of at least four primary colors.

Tetrachromacy is demonstrated among several species of birds, fish, amphibians, reptiles and insects. It was also the normal condition of most mammals in the past; a genetic change made the majority of species of this class eventually lose two of their four cones.

Comment by Dr. Krishna Kumari Challa on March 12, 2016 at 9:23am

Comment by Dr. Krishna Kumari Challa on March 12, 2016 at 9:13am

Why do we change our decisions after taking them?

There are two schools of thought on this problem. One suggestion is that changes of mind happen because we continue to weigh evidence after a choice has been made . This process is called post-decision evidence accumulation. An alternative idea is that the brain uses additional mechanisms to detect and correct previous errors. Support for this theory comes from findings that show that error-related signals are produced in the medial frontal cortex of the human brain. People who have damage to the frontal regions of the brain are also unable to “self-monitor” and identify errors they have made without external feedback. Now a pair of studies in eLife provides the most detailed account yet of the mechanisms underpinning changes of mind – and together, they indicate that both ideas could be right.

Read about the studies here: http://elifesciences.org/content/5/e14790v1?utm_source=content_aler...

Comment by Dr. Krishna Kumari Challa on March 12, 2016 at 8:46am

You think good cholesterol or HDL cholesterol is good for your heart and go for it. You did a wise thing ... unless you have a rare mutation in a protein called SR-BI that binds to HDL cholesterol and triggers its movement from the blood into the liver.

Those who carried the mutations tended to have high HDL cholesterol levels in the blood. But they were also, paradoxically, at higher risk for coronary heart disease!

A study published on March 10 in Science, brought his to light.

The difference between correlation and causation makes for a more complicated conversation. 

 

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

The widespread use of certain insecticides by farmers is making the chemicals less effective at fighting malaria-spreading mosquitoes, a paper shows.

The paper, which aggregated data on the issue from other studies, found a clear link between the use of pyrethroids as an agricultural pesticide in Africa and the resistance of Anopheles mosquitoes to this insecticide. These mosquitoes are the main malaria vector.

Resistance to pyrethroids was once confined to southern Africa, but had spread to Benin, Cameroon, Kenya and Uganda by 2014, the paper says.

“Whilst there is almost certainly a correlation between agricultural use of insecticides and insecticide resistance... I believe the majority of selection for resistance probably comes from the use of insecticides in vector control.”

Mark Hoppe, International Resistance Action Committee Pyrethroids are among the most common insecticides used for indoor spraying and bed net treatments against malaria mosquitoes, the authors say. The chemicals are valuable because they are considered safe for humans.

But the authors found low “kill rates” being reported from trials with pyrethroid-soaked bed nets in areas affected by pyrethroid resistance.
The paper, which was published in the March issue of Trends in Parasitology, recommends more research into alternative insecticides that rely on substances against which mosquitoes do not yet have resistance.

http://www.cell.com/trends/parasitology/abstract/S1471-4922(15)00254-8?_returnURL=http%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS1471492215002548%3Fshowall%3Dtrue

Comment by Dr. Krishna Kumari Challa on March 6, 2016 at 9:12am

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