Science Simplified!

Comment

Comment by Dr. Krishna Kumari Challa on February 24, 2015 at 8:56am

Comment by Dr. Krishna Kumari Challa on February 22, 2015 at 12:52pm

Doctors with conscience speak out
In order to benefit the hospital and meet its commercial needs, one has to do things like keeping patients in the hospital longer than necessary, and doing unnecessary investigations and procedures (including angioplasty) since there was pressure from the management of the hospital.
Read this eye opener here: http://timesofindia.indiatimes.com/india/Doctors-with-conscience-sp...

Comment by Dr. Krishna Kumari Challa on February 20, 2015 at 9:54am

THE CLOSEST KNOWN FLYBY OF A STAR TO THE SOLAR SYSTEM
http://iopscience.iop.org/2041-8205/800/1/L17?fromSearchPage=true
a group of astronomers says it's determined that a small binary star system dubbed "Scholz's star" buzzed the edges of our solar system just 70,000 years ago. On the cosmic time scale, that's so recent that we could still practically wave goodbye from our front door.

At that point in history, there may have been both Neanderthals and anatomically modern humans wandering around. In fact, some believe that is right around the point in history when we were just starting to get our evolutionary act together, developing things like languages, tools and really slick cave paintings that descendants would totally dig for eons.
Unfortunately, those early ancestors probably weren't together enough to notice a binary star hanging out at the edge of the Oort cloud, which is a comet cluster of sorts that basically envelopes our solar system at the furthest reaches of the sun's gravity. (Oort does sound like the sort of name a stereotypical caveman society might dream up for such a concept, though.)

The transient star would have passed within about 52,000 astronomical units (1 a.u. = the distance between Earth and our sun) or 0.8 light-years of us, according to a paper published in Astrophysical Journal Letters.

To get a sense of how close that is, consider that the nearest star we know of today, Proxima Centauri, is 4.2 light-years away.

Scholz's star was only passing through, though. The binary system kept on the move and is now 20 light-years away.

As it moved through the Oort cloud, the star system may have agitated the trillions of small bodies believed to be drifting around out there, potentially showering the inner solar system with comets. Not exactly the best kind of visitor to have in the neighborhood.

Comment by Dr. Krishna Kumari Challa on February 20, 2015 at 8:16am

Potential new vaccine blocks every strain of HIV
A new drug candidate is so potent against all strains of HIV, researchers think it could work as a new kind of vaccine.

Developed by researchers from more than a dozen research institutions and led by a team at the Scripps Research Institute in the US, the drug is effective against doses of HIV-1, HIV-2 and SIV (simian immunodeficiency virus) that have been extracted from humans or rhesus macaques - including what researchers consider to be the ‘hardest-to-stop’ variants. It worked against doses of HIV that are way higher than what would be transmitted between humans, and works for at least eight months after injection.
Scientists announce anti-HIV agent so powerful it can work in a vaccine
Source:
The Scripps Research Institute

Comment by Dr. Krishna Kumari Challa on February 20, 2015 at 8:14am

Extreme strength observed in limpet teeth
Sea snail teeth: The Strongest Known Biological Structures
The teeth of limpets exploit distinctive composite nanostructures consisting of high volume fractions of reinforcing goethite nanofibres within a softer protein phase to provide mechanical integrity when rasping over rock surfaces during feeding. The tensile strength of discrete volumes of limpet tooth material measured using in situ atomic force microscopy was found to range from 3.0 to 6.5 GPa and was independent of sample size. These observations highlight an absolute material tensile strength that is the highest recorded for a biological material, outperforming the high strength of spider silk currently considered to be the strongest natural material, and approaching values comparable to those of the strongest man-made fibres. This considerable tensile strength of limpet teeth is attributed to a high mineral volume fraction of reinforcing goethite nanofibres with diameters below a defect-controlled critical size, suggesting that natural design in limpet teeth is optimized towards theoretical strength limits.
http://rsif.royalsocietypublishing.org/content/12/105/20141326

Comment by Dr. Krishna Kumari Challa on February 20, 2015 at 7:36am

In this amazing video, scientists have sucked the air out of the container and managed to find a pressure/temperature combination that's near the triple point of the fluid, which has been identified as cyclohexane - the triple point is the very precise temperature and pressure at which the three states of matter (solid, liquid and gas) exist in thermodynamic equilibrium.
Cyclohexane at the Triple Point

Comment by Dr. Krishna Kumari Challa on February 20, 2015 at 7:28am

A DNA hard drive has been built that can store data for 1 MILLION years

Scientists have found a way to preserve the world's data for millions of years, by storing it on a tiny strand of DNA preserved in glass.
When you think of humanity’s legacy, the most powerful message for us to leave behind for future civilisations would surely be our billions of terabytes of data. But right now the hard drives and discs that we use to store all this information are frustratingly vulnerable, and unlikely to survive more than a couple of hundred years.

Fortunately scientists have built a DNA time capsule that's capable of safely preserving all of our data for more than a million years.
Researchers already knew that DNA was ideal for data storage. In theory, just 1 gram of DNA is capable of holding 455 exabytes, which is the equivalent of one billion gigabytes, and more than enough space to store all of Google, Facebook and pretty much everyone else's data.

Storing information on DNA is also surprisingly simple - researchers just need to program the A and C base pairs of DNA as a binary '0', and the T and G as a '1'. But the researchers, led by Robert Grass from ETH Zürich in Switzerland, wanted to find out just how long this data would last.

DNA can definitely be durable - in 2013 scientists managed to sequence genetic code from 700,000-year-old horse bones - but it has to be preserved in pretty specific conditions, otherwise it can change and break down as it's exposed to the environment. So Glass's team decided to try to replicate a fossil, to see if it would help them create a long-lasting DNA hard drive.

"Similar to these bones, we wanted to protect the information-bearing DNA with a synthetic 'fossil' shell," explained Grass in a press release.
In order to do that, the team encoded Switzerland’s Federal Charter of 1921 and The Methods of Mechanical Theorems by Archimedes onto a DNA strand - a total of 83 kilobytes of data. They then encapsulated the DNA into tiny glass spheres, which were around 150 nanometres in diameter.

The researchers compared these glass spheres against other packaging methods by exposing them to temperatures of between 60 and 70 degrees Celsius - conditions that replicated the chemical degradation that would usually occur over hundreds of years, all crammed into a few destructive weeks.

They found that even after this sped-up degradation process, the DNA inside the glass spheres could easily be extracted using a fluoride solution, and the data on it could still be read. In fact, these glass casings seem to work much like fossilised bones.

Based on their results, which have been published in Angewandte Chemie, the team predicts that data stored on DNA could survive over a million years if it was stored in temperatures below -18 degrees Celsius, for example, in a facility like the Svalbard Global Seed Vault, which is also known as the ‘Doomsday Vault’. They say it could last 2,000 years if stored somewhere less secure at 10 degrees Celsius - a similar average temperature to central Europe.

The tricky part of this whole process is that the data stored in DNA needs to be read properly in order for future civilisations to be able to access it. And despite advances in sequencing technology, errors still arise from DNA sequencing.
Robust Chemical Preservation of Digital Information on DNA in Silica with Error-Correcting Codes
http://onlinelibrary.wiley.com/doi/10.1002/anie.201411378/full

Comment by Dr. Krishna Kumari Challa on February 19, 2015 at 6:17am

Individuals with Type 2 Diabetes Should Exercise After Dinner
Individuals with Type 2 diabetes have heightened amounts of sugars and fats in their blood, which increases their risks for cardiovascular diseases such as strokes and heart attacks. Exercise is a popular prescription for individuals suffering from the symptoms of Type 2 diabetes, but little research has explored whether these individuals receive more benefits from working out before or after dinner. Now, researchers at the University of Missouri have found that individuals with Type 2 diabetes can lower their risks of cardiovascular diseases more effectively by exercising after a meal.
“This study shows that it is not just the intensity or duration of exercising that is important but also the timing of when it occurs,” said Jill Kanaley, professor in the MU Department of Nutrition and Exercise Physiology. “Results from this study show that resistance exercise has its most powerful effect on reducing glucose and fat levels in one’s blood when performed after dinner.”
Kanaley also found that improvements in participants’ blood sugar and fat levels were short-lived and did not extend to the next day. She suggests individuals practice daily resistance exercise after dinner to maintain improvements.

“Individuals who exercise in the morning have usually fasted for 10 hours beforehand,” Kanaley said. “Also, it is natural for individuals’ hormone levels to be different at different times of day, which is another factor to consider when determining the best time to exercise.”

In the future, Kanaley said she plans to research how exercising in the morning differs from exercising after dinner and how individuals’ hormone levels also affect exercise results.

The study, “Post-dinner resistance exercise improves postprandial risk factors more effectively than pre-dinner resistance exercise in patients with type 2 diabetes,” was published in the Journal of Applied Physiology.
http://jap.physiology.org/content/early/2014/12/23/japplphysiol.009...

Comment by Dr. Krishna Kumari Challa on February 18, 2015 at 10:05am

It’s a firmly established fact straight from Biology 101: Traits such as eye color and height are passed from one generation to the next through the parents’ DNA.

But now, a new study in mice by researchers at Washington University School of Medicine in St. Louis has shown that the DNA of bacteria that live in the body can pass a trait to offspring in a way similar to the parents’ own DNA. According to the authors, the discovery means scientists need to consider a significant new factor – the DNA of microbes passed from mother to child – in their efforts to understand how genes influence illness and health.

The study appears online Feb. 16 in Nature.
Vertically transmissible fecal IgA levels distinguish extra-chromosomal phenotypic variation. Moon C, Baldridge MT, Wallace MA, Burnham C-AD, Virgin HW, Stappenbeck TS. Nature, Feb. 16, 2015

http://www.sciguru.org/newsitem/18448/mothers-can-pass-traits-offsp...

Comment by Dr. Krishna Kumari Challa on February 18, 2015 at 10:03am

A single natural nucleotide mutation alters bacterial pathogen host tropism
Bacteria may be able to jump between species with greater ease than was previously thought
Researchers have found that a single genetic mutation in a strain of bacteria that infects humans enables it to also infect rabbits. The discovery has major implications for how we assess the risks associated with bacterial diseases that can pass between people and animals.

Scientists at the Universities of Glasgow and Edinburgh studied a strain of bacteria called Staphylococcus aureus ST121, which is responsible for widespread epidemics in the global rabbit farming industry.

The team looked at the genetic make-up of ST121 to work out where the strain originated. They also tracked how changes in its genetic code enabled it to infect rabbits.

They concluded that ST121 most likely evolved as the result of a host jump from humans to rabbits around 40 years ago.

A genetic mutation at a single site in the bacterial DNA code was sufficient to convert a human strain into one that could infect rabbits.

The discovery transforms our understanding of the minimal genetic changes that are required for bacteria to infect different species. The results represent a paradigm shift in understanding of the minimal adaptations required for a bacterium to overcome species barriers and establish in new host populations.
http://www.nature.com/ng/journal/vaop/ncurrent/full/ng.3219.html

• ‹ Previous
• 1
• …
• 842
• 843
• 844
• 845
• 846
• …
• 999
• Next ›
• Page