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Comment by Dr. Krishna Kumari Challa on April 5, 2014 at 8:33am

Comment by Dr. Krishna Kumari Challa on April 5, 2014 at 8:26am

The mammalian heart has generally been considered to lack the ability to repair itself after injury, but a 2011 study in newborn mice challenged this view, providing evidence for complete regeneration after resection of 10% of the apex, the lowest part of the heart. In a study published by Cell Press in Stem Cell Reports on April 3, 2014, researchers attempted to replicate these recent findings but failed to uncover any evidence of complete heart regeneration in newborn mice that underwent apex resection.

“Our results question the usefulness of the apex resection model for identifying molecular mechanisms underlying heart regeneration after damage and underscore the need for the scientific community to firmly establish whether or not the mammalian heart is capable of regeneration,” says lead study author Ditte Andersen of Odense University Hospital and the University of Southern Denmark.

- Cell Press

Comment by Dr. Krishna Kumari Challa on April 5, 2014 at 8:24am

A study published this week in PLOS ONE authored by Dr. Henry Sun and his postdoctoral student Dr. Gaosen Zhang of Nevada based research institute DRI provides new evidence that Earth bacteria can do something that is quite unusual. Despite the fact that these bacteria are made of left-handed (L) amino acids, they are able to grow on right-handed (D) amino acids. This DRI study, funded by the NASA Astrobiology Institute and the NASA Exobiology Program, takes a closer look at what these implications mean for studying organisms on Earth and beyond.

“This finding is important because D-amino acids are slowly produced in soils through geochemical transformation of L amino acids. If they were allowed to accumulate, they would poison the environment for plants and animals. Our research shows that it is the bacteria that prevent D-amino acids from accumulating to toxic levels,” explains Dr. Sun.
http://www.dri.edu/news/4633-bacteria-get-new-badge-as-planet-s-det...

Comment by Dr. Krishna Kumari Challa on April 5, 2014 at 8:21am

For years, researchers have been interested in developing quantum computers—the theoretical next generation of technology that will outperform conventional computers. Instead of holding data in bits, the digital units used by computers today, quantum computers store information in units called “qubits.” One approach for computing with qubits relies on the creation of two single photons that interfere with one another in a device called a waveguide. Results from a recent applied science study at Caltech support the idea that waveguides coupled with another quantum particle—the surface plasmon—could also become an important piece of the quantum computing puzzle.

The work was published in the print version of the journal Nature Photonics the week of March 31.

http://www.nature.com/nphoton/index.html

Comment by Dr. Krishna Kumari Challa on April 5, 2014 at 5:31am

Comment by Dr. Krishna Kumari Challa on April 4, 2014 at 8:53am

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

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