Comment

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

Comment by Dr. Krishna Kumari Challa on February 18, 2015 at 9:49am

Factors Underlying Different Myopia Prevalence between Middle- and Low-income Provinces in China
A study of 20,000 children shows that nearsightedness is twice as prevalent in middle-income areas than lower-income ones in China.
In one of the largest population-based studies ever conducted on nearsightedness in children, researchers have discovered that lower-income students in China have better vision than their middle-class counterparts. Data show that nearsightedness, also called myopia, is twice as prevalent in the middle-income province of Shaanxi compared to the poorer neighboring province of Gansu. The study was published in Ophthalmology, the journal of the American Academy of Ophthalmology.
Living in the middle-class area was associated with a 69 percent increased risk for nearsightedness, even after adjusting for other risk factors, such as time spent reading, outdoor activity and whether the student's parents wore glasses. Higher math scores were associated with increased myopia in all children while nearsightedness was less prevalent in males overall. The research team also looked at whether the use of blackboards, as opposed to textbooks, played a role in staving off myopia. Students in the lower-income area rely more on blackboards to learn in the classroom as they may have difficulty affording books, while students in the middle-income areas used blackboards less often.
They found that using blackboards had a "protective effect" against nearsightedness when examined as a variable alone, possibly because blackboards do not require the kind of close-up focusing that may increase myopia. However, when adjusting for other factors, they found no statistically significant differences between lower-income and middle-class students that might explain higher myopia prevalence in richer areas.
Previous studies have found that people who had higher levels of education and years spent in school were more likely to be nearsighted. Many researchers also postulate that exposure to certain kinds of light, particularly indoor versus outdoor light, may be responsible for the uptick in myopia. Recent studies of children and young adults in Denmark and across Asia show that more time outdoors and exposure to daylight is associated with less nearsightedness.
http://www.aaojournal.org/article/S0161-6420%2814%2901196-8/abstract

Comment by Dr. Krishna Kumari Challa on February 18, 2015 at 9:11am

Persistent fungal root endophytes ( those living inside hosts) isolated from a wild barley species suppress seed-borne infections in a barley cultivar.
ABSTRACT: Ten fungal root endophytes were isolated from wild populations of Hordeum murinum ssp. murinum L. and inoculated onto untreated seeds of a barley cultivar using five artificial and one soil-based growth media. A co-inoculant of all ten isolates as well as two individual isolates successfully suppressed the development of seed-borne fungal infections on germinated and ungerminated seed. The two most successful isolates were also the most persistent as re-emergents and may provide real potential for development as crop inoculants. All isolates were more persistent in barley exposed to light after germination. The soil-based compost was associated with the greatest degree of seed-borne infection suppression, and the most successful artificial medium for suppressing seed-borne infections was also the medium with the most similar pH to the soil at the sampling sites. These results suggest a direct antagonistic effect of the fungal isolates on seed-borne pathogens without the induction of plant defences.
This information can be used to control plant diseases.
http://www.researchgate.net/publication/268575042_Persistent_fungal...

--

And in humans ---

Electronic Medicine Fights Disease

Stimulation of the nervous system could replace drugs for inflammatory and autoimmune conditions.

Comment by Dr. Krishna Kumari Challa on February 18, 2015 at 9:06am

Raman spectroscopy could help neurosurgeons find those errant cancer cells. A team led by engineer Frédéric Leblond of Montreal Polytechnique and neurosurgeon Kevin Petrecca of McGill University, also in Montreal, has developed a Raman probe that distinguishes between normal and cancer cells. They showed their method could find previously undetectable cancer cells in the brains of glioma patients .
http://stm.sciencemag.org/content/7/274/274ra19

“It’s very uncomfortable when you’re performing an operation and are not certain if you are removing all the cancer,” because missing some can impact a patient’s survival, Petrecca says. The Raman probe, he says, allows surgeons to spot cancer cells they might have thought were normal.

To use the tool, a surgeon simply holds a fiber-optic probe in contact with the brain tissue to collect a Raman spectrum. The researchers use an algorithm that statistically analyzes the data to differentiate between healthy and cancerous cells.

The next step is to run clinical trials to demonstrate that the Raman technique can improve surgery outcomes. He and his collaborators plan to start such a trial soon.

Comment by Dr. Krishna Kumari Challa on February 18, 2015 at 8:58am

• ‹ Previous
• 1
• …
• 953
• 954
• 955
• 956
• 957
• …
• 1110
• Next ›
• Page