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Comment by Dr. Krishna Kumari Challa on August 21, 2015 at 7:12am

Who do you think is the top predator in the world? It is the human being, according to scientists!

''The unique ecology of human predators''

Humans are a unique “super-predator” that hunts and kills other species many times more efficiently than the other top predators both on land and sea, scientists have found.

A study into the effectiveness of predatory animals has placed people head and shoulders above other top carnivores such as the lion and wolf on land and the shark and killer whale in the sea.

The researchers estimate that ocean fishing has resulted in humans exploiting adult fish populations at about 14 times the rate of other marine predators, while humans have hunted and killed adult land animals at around nine times the rate of other animal predators.

Human hunting and fishing has had an extraordinary impact on the natural world and its ruthless efficiency is laid bare in a detailed survey of 2,125 species of terrestrial and marine predators around the world, published in the journal Science.

The study revealed that human hunting and fishing is qualitatively different to the predatory behaviour shown by other species. It has, for instance, concentrated on killing mature adult animals rather than their offspring, which the scientists have likened to eating into the “reproductive capital” rather than the “reproductive interest” of the natural world.

The study found that humans show another remarkable hunting trait by their ability to target other top predators as potential prey, especially in the sea where the decimation of top carnivores such as sharks, tuna fish and marlin has fundamentally changed the balance of some marine ecosystems.

Our impacts are as extreme as our behaviour and the planet bears the burden of our predatory dominance….These are extreme outcomes that non-human predators seldom impose.

Some herbivore populations kept in check by neither predators nor diseases have exploded, robbing food resources from a diversity of life, from insects important to humanity to birds we cherish, according to the scientists.

http://www.sciencemag.org/content/349/6250/858

Comment by Dr. Krishna Kumari Challa on August 21, 2015 at 6:07am

Computers from DNA:
Scientists have found a way to 'switch' the structure of DNA using copper salts and EDTA (Ethylenediaminetetraacetic acid) - an agent commonly found in shampoo and other household products.

It was previously known that the structure of a piece of DNA could be changed using acid, which causes it to fold up into what is known as an 'i-motif'.

But new research published today in the journal Chemical Communications reveals that the structure can be switched a second time into a hair-pin structure using positively-charged copper (copper cations). This change can also be reversed using EDTA.

The applications for this discovery include nanotechnology - where DNA is used to make tiny machines, and in DNA-based computing - where computers are built from DNA rather than silicon.

It could also be used for detecting the presence of copper cations, which are highly toxic to fish and other aquatic organisms, in water.
A potential application of this finding could be to create logic gates for DNA based computing. Logic gates are an elementary building block of digital circuits - used in computers and other electronic equipment. They are traditionally made using diodes or transistors which act as electronic switches.

"This research expands how DNA could be used as a switching mechanism for a logic gate in DNA-based computing or in nano-technology."

'Reversible DNA i-motif to hairpin switching induced by copper (ii) cations' is published in the journal Chemical Communications.

http://phys.org/news/2015-08-uea-dna.html#jCp

Comment by Dr. Krishna Kumari Challa on August 21, 2015 at 6:02am

How to keep surfaces dry underwater is what is bothering the scientific community for a long time. Now we might have found the answers to teh question.
Northwestern Univ. engineers have examined a wide variety of surfaces that can do just that—and, better yet, they know why.

The research team is the first to identify the ideal "roughness" needed in the texture of a surface to keep it dry for a long period of time when submerged in water. The valleys in the surface roughness typically need to be less than one micron in width, the researchers found. That's really small—less than one millionth of a meter—but these nanoscopic valleys have macroscopic impact.

Understanding how the surfaces deflect water so well means the valuable feature could be reproduced in other materials on a mass scale, potentially saving billions of dollars in a variety of industries, from antifouling surfaces for shipping to pipe coatings resulting in lower drag. That's science and engineering, not serendipity, at work for the benefit of the economy.
The trick is to use rough surfaces of the right chemistry and size to promote vapor formation, which we can use to our advantage. When the valleys are less than one micron wide, pockets of water vapor or gas accumulate in them by underwater evaporation or effervescence, just like a drop of water evaporates without having to boil it. These gas pockets deflect water, keeping the surface dry, according to the new finding.
In a study published by Scientific Reports, Patankar and his co-authors explain and demonstrate the nanoscale mechanics behind the phenomenon of staying dry underwater.
The researchers also report that nature uses the same strategy of surface roughness in certain aquatic insects, such as water bugs and water striders. Small hairs on the surfaces of their body have the less-than-one-micron spacing, allowing gas to be retained between the hairs.
The researchers focused on the nanoscopic structure of surfaces, which, at the nanoscale, are somewhat akin to the texture of a carpet, with tiny spike-like elevations separated by valley-shaped pores in between.

When submerged, water tends to cling to the top of the spikes, while air and water vapor accrue in the pores between them. The combination of trapped air and water vapor within these cavities forms a gaseous layer that deters moisture from seeping into the surface below. When the researchers looked at the rough surfaces under the microscope, they could see clearly the vacant gaps—where the protective water vapor is.
They demonstrated that when the valleys are less than one micron in width, they can sustain the trapped air as well as vapor in their gasified states, strengthening the seal that thwarts wetness.

Source: Northwestern Univ.

http://www.rdmag.com/news/2015/08/engineers-identify-how-keep-surfa...

Comment by Dr. Krishna Kumari Challa on August 19, 2015 at 9:36am

Antibiotic resistance in wild life is mainly because of  Water.  It seems to be the most important medium exposing animals to antibiotic resistance, with water-associated species such as hippos and waterbucks having higher levels of multi-drug resistant microorganisms.

• Bacteria from wildlife and humans have similar resistance

• Resistance could accumulate up the food chain

• Approach may allow early detection of antimicrobial resistance epidemics

In addition, bacteria resistant to multiple drugs were more common in animals, such as baboons, warthogs and mongooses, which live in urbanised areas, and in carnivorous species.
Resistance may accumulate up the food chain making apex predators such as crocodile, leopard and hyena important ecosystem sentinels.

Studying wild animals helps to understand how resistance moves from humans and farming systems across ecosystems and ultimately back to humans.

http://www.scidev.net/global/disease/news/wildlife-warning-antibiot...

Comment by Dr. Krishna Kumari Challa on August 19, 2015 at 8:59am

Delayed Development of Brain Connectivity in Adolescents With Schizophrenia and Their Unaffected Siblings
Some Siblings can overcome Schizophrenia Risk by altering their genetic predisposition to the disease.
Despite their shared genetic predisposition to schizophrenia, siblings of patients with childhood-onset schizophrenia are eventually able to catch up with normally developing peers. The study documenting these findings, published in JAMA Psychiatry, opens up new avenues for treating the hugely debilitating condition. “The greatest risk for schizophrenia is family history, but the majority of siblings of individuals with the disorder are unaffected,” said Dr. Andrew Zalesky from the University of Melbourne, lead author of the study. “So why are these brothers and sisters able to overcome the risk? Looking for these biological factors that protect a person from developing schizophrenia opens up a new direction in the search for treatments.” Zalesky and his team used magnetic resonance imaging (MRI) to map the brains of 109 children with childhood-onset schizophrenia (COS), from ages 12 to 24. They compared the images with scans taken of the participants’ brothers and sisters without COS to see if similar brain changes took place over time. The siblings without COS showed similar delays in brain connectivity while growing up, but these connections tended to normalise or ‘catch up’ to those of normally developing adolescents. Zalesky said the ability of the siblings to catch up and develop important brain circuitry means there is a degree of resilience to their risk for schizophrenia.
http://archpsyc.jamanetwork.com/article.aspx?articleid=2396494

Comment by Dr. Krishna Kumari Challa on August 19, 2015 at 8:55am

Abrupt changes in Indian summer monsoon strength during 33,800 to 5500 years B.P.
Abstract

Speleothem proxy records from northeastern (NE) India reflect seasonal changes in Indian summer monsoon strength as well as moisture source and transport paths. We have analyzed a new speleothem record from Mawmluh Cave, Meghalaya, India, in order to better understand these processes. The data show a strong wet phase 33,500–32,500 years B.P. followed by a weak/dry phase from 26,000 to 23,500 years B.P. and a very weak phase from 17,000 to 15,000 years B.P. The record suggests abrupt increase in strength during the Bølling-Allerød and early Holocene periods and pronounced weakening during the Heinrich and Younger Dryas cold events. We infer that these changes in monsoon strength are driven by changes in temperature gradients which drive changes in winds and moisture transport into northeast India.

http://onlinelibrary.wiley.com/doi/10.1002/2015GL064015/abstract

Comment by Dr. Krishna Kumari Challa on August 19, 2015 at 8:44am

Acoustic stealth - this is what gives owls an edge over their prey...
A new study says ... Owls are equipped with state-of-the-art stealth technology to help them swoop on prey undetected.
The night hunters have feathers that absorb aerodynamic sound and suppress the vibrations that occur when a bird flaps its wings.

During flight, an owl’s feathers extract mechanical energy and convert it into heat. The result is perfect silence as the bird approaches to within inches of a mouse or vole.
Scientists used lasers and high-speed cameras to analyse and compare long-eared owl, eagle, and pigeon feathers during flight.
While differing in size, all three birds have a similar “flapping” style.

Lead researcher Jinkui Chu, from Dalian University of Technology in China, said: “Many owls have a unique and fascinating ability to fly so silently that they are out of their prey’s hearing range, due to their feather structure.

“This behaviour has long been of interest to engineers, as we seek to apply the owl’s noise-reduction mechanisms to other purposes and situations that benefit society.

“Now, however, we know the owls’ silent flight ability is even more superior than we thought.

“You could say of all birds it is the ‘king of acoustic stealth’. It not only manages to suppress aerodynamic noise when gliding, but also mechanical noise caused by vibration during flying.

“This is remarkable, considering the sudden jumping, bending and twisting the wings are subjected to when flapping and the noise that creates for other birds.

“In the scientific world, the process used to eliminate this mechanical noise is called ’damping’ — which means the extraction of mechanical energy from a vibrating system usually by converting it into heat and allowing it to remain steady.”

Comment by Dr. Krishna Kumari Challa on August 18, 2015 at 8:42am

Whistled Turkish alters language asymmetries
Whistled languages represent an experiment of nature to test the widely accepted view that language comprehension is to some extent governed by the left hemisphere in a rather input-invariant manner. Indeed, left-hemisphere superiority has been reported for atonal and tonal languages, click consonants, writing and sign languages. The right hemisphere is specialized to encode acoustic properties like spectral cues, pitch, and melodic lines and plays a role for prosodic communicative cues. Would left hemisphere language superiority change when subjects had to encode a language that is constituted by acoustic properties for which the right hemisphere is specialized? Whistled Turkish uses the full lexical and syntactic information of vocal Turkish, and transforms this into whistles to transport complex conversations with constrained whistled articulations over long distances . The comprehension of vocally vs. whistled identical lexical information in native whistle-speaking people of mountainous Northeast Turkey has been tested in this study. It was found that that whistled language comprehension relies on symmetric hemispheric contributions, associated with a decrease of left and a relative increase of right hemispheric encoding mechanisms. The results demonstrate that a language that places high demands on right-hemisphere typical acoustical encoding creates a radical change in language asymmetries. Thus, language asymmetry patterns are in an important way shaped by the physical properties of the lexical input.

http://www.cell.com/current-biology/abstract/S0960-9822%2815%2900794-0

Comment by Dr. Krishna Kumari Challa on August 16, 2015 at 9:37am

New type of glass produced...
When Prof. Juan de Pablo and his collaborators set about to explain unusual peaks in what should have been featureless optical data, they thought there was a problem in their calculations. In fact, what they were seeing was real. The peaks were an indication of molecular order in a material thought to be entirely amorphous and random: Their experiments had produced a new kind of glass.
Their unforeseen discovery, reported in a paper published in the Proceedings of the National Academy of Sciences and chosen by Science as an editor's choice paper in Materials Science, could offer a simple way to improve the efficiency of electronic devices such as light-emitting diodes, optical fibers and solar cells. It also could have important theoretical implications for understanding the still surprisingly mysterious materials called glasses.

The scientists grew the glass by vaporizing large organic molecules in a high vacuum and depositing them slowly, thin layer by thin layer, onto a substrate at a precisely controlled temperature. When the sample was thick enough, they analyzed it using spectroscopic ellipsometry—a technique that measures the way incident light or laser radiation interacts with the material being investigated.
The answer, the scientists discovered, lay in the way the material was created. In liquids—and glass is a type of liquid—the molecules at the surface interact with molecules in the air, sometimes causing them to pack together and line up differently than the randomly arrayed molecules in the bulk of the liquid. The vapor deposition process used in the experiments amounts to laying down one "surface" on top of another. The molecules in each layer get "trapped" in the orientation they had when they were truly, however briefly, on the surface.

In order for this to happen, the researchers discovered, the glass must be grown within the relatively narrow temperature range at which a liquid changes into a solid-like glass. Varying the temperature within that window allows the scientists to "tune" the degree of order. Once the deposition process is finished, the material is stable and changing temperatures within a wide range doesn't affect it.

Only a small fraction of the molecules in the group's samples are oriented in a different direction than the rest of the glass molecules. But that is enough to change the optical properties of these materials tremendously. The group will continue to investigate these new materials, trying different molecules and looking to find out if they can enhance the effect.

A theoretical investigation of these findings also awaits.

http://phys.org/news/2015-08-molecular-scientists-unexpectedly-glas...

Comment by Dr. Krishna Kumari Challa on August 16, 2015 at 9:12am

Australian researchers have developed a nano-sized capsule that can be delivered to a patient intravenously to immediately target and break down the blot clots that cause heart attacks and strokes.

No only does the minuscule device start working within minutes, it’s portable, which means it can be used in emergency situations before the patient has even made it to hospital. "This can be given in the ambulance straight away so you really save a lot of time and restore the blood flow to the critical organs much faster than currently possible".
Around 80 percent of all strokes occur when a fatty deposit or blood clot blocks an artery that supplies blood to the brain. If this formation of blood clots, known as thrombosis, happens to block blood flow to the heart, a heart attack can follow. The longer the brain or heart are without oxygenated blood, the greater the risk that vital tissues will begin to die, so breaking down these clots as soon as possible is key.

If the team can get their device commercialised, it’s set to make a huge difference to the many heart attack and stoke patients who don’t actually respond to current treatments.
The new nanocapsule device only releases the medication in areas where a clot is growing exponentially and blocking a vessel and doesn't have the side effect of unnecessary internal bleeding. "The drug-loaded nanocapsule is coated with an antibody that specifically targets activated platelets, the cells that form blood clots.""
"Once located at the site of the blood clot, thrombin - a molecule at the centre of the clotting process - breaks open the outer layer of the nanocapsule, releasing the clot-busting drug. We are effectively hijacking the blood clotting system to initiate the removal of the blockage in the blood vessel."
http://newsroom.melbourne.edu/news/new-clot-busting-treatment-targe...
New clot-busting treatment targets number one killer

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