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Comment by Dr. Krishna Kumari Challa on April 4, 2014 at 8:45am

True age of moon is finally revealed
A new study has revealed the moon is 4.47 billion-years-old, after a team of planetary scientists discovered it was formed 95 million years after the birth of the solar system.
This makes the Earth's moon up to 60 million years younger than some previous estimates, a study published on Wednesday found.

Researchers used a new way to calculate the birthday of the planet's only natural satellite.

Astronomer John Chambers, with the Carnegie Institution for Science in Washington DC, said the mega-asteroid that smashed into Earth, launching debris that later became the moon, occurred about 95 million years after the birth of the solar system.

"We think that the thing that hit Earth and ended up forming the moon, the lion's share of it stayed on Earth," he explained.

"A small fraction of its mass and some material from Earth was pushed off into space to form the moon. That was probably the last big event," he added.

The study, published in the journal Nature, is based on 259 computer simulations of how the solar system evolved.

The programs simulate the crashes and mergers of the small bodies until they meld into the rocky planets that exist today.

Earth's last big chuck came from a Mars-sized body that hit about 95 million years after the solar system's formation when measured by that geologic clock, the study showed.

At 99.9 per cent accurate, the study disputes some previous estimates that the moon-forming impact occurred as early as 30 million to 40 million years after the solar system's formation.
- The independent

Comment by Dr. Krishna Kumari Challa on April 4, 2014 at 7:16am

Coronary Artery Disease Prevalence Is Higher among Celiac Disease Patients
People with celiac disease appear to have an increased risk of heart disease. Physicians Rama Gajulapalli and Deepak Pattanshetty of the Cleveland Clinic analyzed a database of more than 22 million people and, using medical coding, identified 24,530 with celiac disease. Probing the records further, they found that 9.5 percent of the celiac patients had coronary artery disease, compared with 5.6 percent of those without celiac. In people age 65 or older, 28.6 percent of celiac patients but only 13.2 percent of the others had coronary artery disease.
http://www.abstractsonline.com/pp8/#!/3392/presentation/36953

Comment by Dr. Krishna Kumari Challa on April 4, 2014 at 7:14am

Sleep is important. It cleans our brain cells and helps consolidate our memories. Lack of sleep is blunts our ability to focus, makes us dangerous drivers and can make us eat too much.

In a paper published March 19 in the Journal of Neuroscience, Zhang and her group showed that three hours of lost sleep in the mouse playground produced an increase in Sirtuin3, or SIRT3, a protein in a cell’s mitochondria. SIRT3 has a lot of functions, and one of them is reducing chemicals called reactive oxygen species. These molecules are capable of binding to and disrupting all sorts of cellular processes. ROS are a natural by-product of a cell’s daily life, but too many accumulating in the cell can get dangerous as the molecules bind to normal proteins, causing damage and eventually cell death.
We didn’t think the brain got injured from sleep loss,” Veasey says. “Now we know it does.” She explains that the next step will be to see if there is similar damage in humans who have done large amounts of shift work, perhaps by examining post-mortem brains. Veasey also plans to see if increasing SIRT3 can protect against the effects of all-nighters.
http://www.jneurosci.org/content/34/12/4418.abstract
Modern society enables a shortening of sleep times, yet long-term consequences of extended wakefulness on the brain are largely unknown. Essential for optimal alertness, locus ceruleus neurons (LCns) are metabolically active neurons that fire at increased rates across sustained wakefulness. We hypothesized that wakefulness is a metabolic stressor to LCns and that, with extended wakefulness, adaptive mitochondrial metabolic responses fail and injury ensues. The nicotinamide adenine dinucleotide-dependent deacetylase sirtuin type 3 (SirT3) coordinates mitochondrial energy production and redox homeostasis. We find that brief wakefulness upregulates SirT3 and antioxidants in LCns, protecting metabolic homeostasis. Strikingly, mice lacking SirT3 lose the adaptive antioxidant response and incur oxidative injury in LCns across brief wakefulness. When wakefulness is extended for longer durations in wild-type mice, SirT3 protein declines in LCns, while oxidative stress and acetylation of mitochondrial proteins, including electron transport chain complex I proteins, increase. In parallel with metabolic dyshomeostasis, apoptosis is activated and LCns are lost. This work identifies mitochondrial stress in LCns upon wakefulness, highlights an essential role for SirT3 activation in maintaining metabolic homeostasis in LCns across wakefulness, and demonstrates that extended wakefulness results in reduced SirT3 activity and, ultimately, degeneration of LCns.

Comment by Dr. Krishna Kumari Challa on April 4, 2014 at 6:54am

Comment by Dr. Krishna Kumari Challa on April 3, 2014 at 6:55am

10 persistent cancer myths debunked

Myth 1: Cancer is a man-made, modern disease
Myth 2: Superfoods prevent cancer
Myth 3: ‘Acidic’ diets cause cancer
Myth 4: Cancer has a sweet tooth
Myth 5: Cancer is a fungus – and sodium bicarbonate is the cure
Myth 6: There’s a miracle cancer cure…
Myth 7: …And Big Pharma are suppressing it
Myth 8: Cancer treatment kills more than it cures
Myth 9: We’ve made no progress in fighting cancer
Myth 10: Sharks don’t get cancer
http://scienceblog.cancerresearchuk.org/2014/03/24/dont-believe-the...

Comment by Dr. Krishna Kumari Challa on April 3, 2014 at 6:40am

Multifunctional wearable devices for diagnosis and therapy of movement disorders
Wearable systems that monitor muscle activity, store data and deliver feedback therapy are the next frontier in personalized medicine and healthcare. However, technical challenges, such as the fabrication of high-performance, energy-efficient sensors and memory modules that are in intimate mechanical contact with soft tissues, in conjunction with controlled delivery of therapeutic agents, limit the wide-scale adoption of such systems. Here, we describe materials, mechanics and designs for multifunctional, wearable-on-the-skin systems that address these challenges via monolithic integration of nanomembranes fabricated with a top-down approach, nanoparticles assembled by bottom-up methods, and stretchable electronics on a tissue-like polymeric substrate. Representative examples of such systems include physiological sensors, non-volatile memory and drug-release actuators. Quantitative analyses of the electronics, mechanics, heat-transfer and drug-diffusion characteristics validate the operation of individual components, thereby enabling system-level multifunctionalities.
http://www.nature.com/nnano/journal/vaop/ncurrent/full/nnano.2014.3...

Comment by Dr. Krishna Kumari Challa on April 3, 2014 at 6:11am

Comment by Dr. Krishna Kumari Challa on April 2, 2014 at 9:21am

Understanding the different categories of facial expressions of emotion regularly used by us is essential to gain insights into human cognition and affect as well as for the design of computational models and perceptual interfaces. Past research on facial expressions of emotion has focused on the study of six basic categories—happiness, surprise, anger, sadness, fear, and disgust. However, many more facial expressions of emotion exist and are used regularly by humans. This paper describes an important group of expressions, which we call compound emotion categories. Compound emotions are those that can be constructed by combining basic component categories to create new ones. For instance, happily surprised and angrily surprised are two distinct compound emotion categories. The present work defines 21 distinct emotion categories. Sample images of their facial expressions were collected from 230 human subjects. A Facial Action Coding System analysis shows the production of these 21 categories is different but consistent with the subordinate categories they represent (e.g., a happily surprised expression combines muscle movements observed in happiness and surprised). We show that these differences are sufficient to distinguish between the 21 defined categories. We then use a computational model of face perception to demonstrate that most of these categories are also visually discriminable from one another.
Compound facial expressions of emotion
http://www.pnas.org/content/early/2014/03/25/1322355111

Comment by Dr. Krishna Kumari Challa on April 2, 2014 at 9:16am

Methane-spewing microbe blamed in Earth's worst mass extinction
A tiny methane-producing microbe may have been responsible for the largest mass extinction in Earth's history.

Fossil remains show sometime around 252 million years ago, about 90% of all species on Earth were suddenly wiped out — by far the largest of this planet's five known mass extinctions. But pinpointing the culprit has been difficult till now.

A team of MIT researchers has found enough evidence to reveal what caused it. They say we will need a microscope to see the killers.

The perpetrators, according to the new study, were not asteroids, volcanoes or raging coal fires — all of which have been implicated previously. Rather, they were a form of microbes — specifically, methane-producing archaea called Methanosarcina — that suddenly bloomed explosively in the oceans, spewing prodigious amounts of methane into the atmosphere and dramatically changing the climate and chemistry of the oceans.

The reason for the sudden, explosive growth of the microbes may have been their novel ability to use a rich source of organic carbon, aided by a sudden influx of a nutrient required for their growth: the element nickel, emitted by massive volcanism at just that time.

MIT professor of geophysics Daniel Rothman, postdoc Gregory Fournier and five other researchers at MIT and in China built upon three independent sets of evidence.

First, geochemical evidence shows an exponential increase of carbon dioxide in the oceans at the time of the so-called end-Permian extinction. Second, genetic evidence shows a change in Methanosarcina at that time, allowing it to become a major producer of methane from an accumulation of carbon dioxide in the water. Finally, sediments show a sudden increase in the amount of nickel deposited at exactly this time.

The carbon deposits show something caused a significant uptick in the amount of carbon-containing gases — carbon dioxide or methane — produced at the time of the mass extinction.

"A rapid initial injection of carbon dioxide from a volcano would be followed by a gradual decrease," Fournier says. "Instead, we see the opposite: a rapid, continuing increase. That suggests a microbial expansion. The growth of microbial populations is among the few phenomena capable of increasing carbon production exponentially or even faster."

Scientists then carried out genomic analysis of what caused this.

It turns out that Methanosarcina had acquired a particularly fast means of making methane, through gene transfer from another microbe — and the team's detailed mapping of the organism's history now shows this transfer happened at about the time of the end-Permian extinction.

The resulting outburst of methane produced effects similar to those predicted by current models of global climate change: a sudden, extreme rise in temperatures, combined with acidification of the oceans. In the case of the end-Permian extinction, virtually all shell-forming marine organisms were wiped out — consistent with the observation that such shells cannot form in acidic waters.
- Reuters

Comment by Dr. Krishna Kumari Challa on April 2, 2014 at 9:01am

Deforestation of sandy soils a greater climate threat
Deforestation may have far greater consequences for climate change in some soils than in others, according to new research led by Yale University scientists -- a finding that could provide critical insights into which ecosystems must be managed with extra care because they are vulnerable to biodiversity loss and which ecosystems are more resilient to widespread tree removal. In a comprehensive analysis of soil collected from 11 distinct U.S. regions, from Hawaii to northern Alaska, researchers found that the extent to which deforestation disturbs underground microbial communities that regulate the loss of carbon into the atmosphere depends almost exclusively on the texture of the soil. The results were published in the journal Global Change Biology.
http://environment.yale.edu/

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