Differences in brain’s language circuits linked to dyslexia

Washington, May 11 (ANI): Despite getting an appropriate education and demonstrating intellectual ability in other areas, kids children with dyslexia often struggle with reading, writing, and spelling. Now, scientists have found the reason behind it.

They have found that these children”s difficulties with written language may be linked to structural differences within an important information highway in the brain known to play a role in oral language.

Vanderbilt University researchers Sheryl Rimrodt and Laurie Cutting and colleagues at Johns Hopkins University and Kennedy Krieger Institute used an emerging MRI technique, called diffusion tensor imaging (DTI), to discover evidence linking dyslexia to structural differences in an important bundle of white matter in the left-hemisphere language network.

White matter is made up of fibers that can be thought of as the wiring that allows communication between brain cells; the left-hemisphere language network is made up of bundles of these fibres and contains branches that extend from the back of the brain (including vision cells) to the front parts that are responsible for articulation and speech.

“When you are reading, you are essentially saying things out loud in your head. If you have decreased integrity of white matter in this area, the front and back part of your brain are not talking to one another. This would affect reading, because you need both to act as a cohesive unit,” said Cutting.

Rimrodt and Cutting used the DTI technique to map the course of an important white matter bundle in this network and discovered that it ran through a frontal brain region known to be less well organised in the dyslexic brain.

They also found that fibers in that frontal part of the tract were oriented differently in dyslexia.

Rimrodt sai:, “To find a convergence of MRI evidence that goes beyond identifying a region of the brain that differs in dyslexia to linking that to an identifiable structure and beginning to explore physical characteristics of the region is very exciting. It brings us a little bit closer to understanding how dyslexia happens.”

The findings are published in the June 2010 issue of Elsevier”s Cortex. (ANI)

Mum”s voice ”can spur recovery from a coma”

Washington, May 11 (ANI): Mother”s voice can spur recovery from a coma, suggests a new American study.

In January 2009, Ryan, 21, a college student from Huntley, Ill., was in a coma after he had been flung from his snowmobile into a tree during an ice storm.

He had a traumatic brain injury; the fibres of his brain had been twisted and stretched from the impact.

Recordings from Ryan”s mother, father or sister were played through headphones for him four times a day.

Ryan”s mother Karen Schroeder”s voice, recorded on a CD, reminded him of his 4-H project when he was 10 and decided to raise pigs.

She said: “You bid on three beautiful squealing black and white piglets at the auction.

“We took them home in the trunk of our Lincoln Town Car, because we didn”t have a truck.”

All the recordings were part of a new clinical trial investigating whether repeated stimulation with familiar voices can help repair a coma victim”s injured brain networks and spur his recovery.

Ryan regained consciousness after nearly one month in the trial and has made steady progress during the past year.

Researchers, however, won”t know for certain if the therapy helped his recovery until the study is over.

Theresa Pape, a research assistant professor of physical medicine and rehabilitation at Northwestern University Feinberg School of Medicine and a research health scientist at Hines VA Hospital, is leading the study.

The research may be useful to young people like Ryan as well as soldiers injured in combat, who have a high rate of traumatic brain injuries from roadside bombs.

Pape said: “Traumatic brain injury is a huge issue in our society.

“Every 21 seconds, we have a new head injury and about one-third of those will be severe.”

Pape hopes the study will provide an answer to the question that families are desperate to know when a loved one is in a coma: ”Can he hear me?”

She is especially eager to know if these family voices can facilitate repair of the brain to improve the subject”s ability to function and process and understand information.

Pape”s hypothesis is that repeated exposure to familiar voices could help repair the brain”s neural networks, some of which become sheared in traumatic brain injury.

In a previous small pilot study, Pape observed that subjects in a vegetative state responded more to the voices of people who are familiar to them compared with non-familiar voices.

When those subjects heard voices of their family members, an MRI scan showed that parts of their brain were activated, appearing as bright yellow and red blobs of light scattered in an unorganised pattern.

With unfamiliar voices, there was little activation.

Pape said: “The question became are the familiar voices therapeutic in some way?

“Will they spur an improvement in behavior?”

She added: “I was weaned on language processing, how the brain responds to different linguistic stimuli as well as familiar or non-familiar voices, different sounds.

“This is a very speech pathology-based study.” (ANI)

Germanium ”tissue paper” could stop a bullet, power an iPod

Washington, April 28 (ANI): Tissue paper could soon be used to make bulletproof vests and harness solar energy, suggests a new American research.

Tissue paper, made from normally brittle germanium and silicon, contains individual fibres that are as strong as bulletproof Kevlar.

These germanium nanowires could block bullets and draw solar energy if they are woven into traditional fabric or embedded in hard plastics.

“Paper is made of wood fibers compressed together,” Discovery News quoted study co-author Brian Korgel, a scientist at the University of Texas at Austin, as saying.

“In this case, we took bulk semiconductors, turned them into nanowires and compressed them together to make a material with a tissue paper consistency.”

Germanium is generally quite hard and brittle.

Korgel said: “When I handle a block of the bulk material, I have to handle it very carefully so it doesn”t break.”

But germanium tissue paper is flexible and doesn”t break when bent.

The tissue paper”s individual nanowires are also quite strong and have a similar strength-to-weight ratio as Kevlar.

Moreover, they are capable of absorbing blows that would ordinarily shatter a germanium block.

However, the development of bulletproof vests from germanium wires may not come easy.

Kevlar blocks bullets because its individual fibbers are strong and so are the bonds between the fibers.

But individual germanium nanowires are not there yet.

Korgel and his teams also want to use the new fabric”s semiconducting properties for harnessing solar power.

Korgel”s research has appeared in a new paper in ACS Nano. (ANI)

Natural hydrogel may boost spinal cord healing

Washington, Sep 18 (ANI): A jab of biomaterial gel into a spinal cord injury site may significantly improve healing, according to researchers at the Barrow Neurological Institute at St. Joseph’s Hospital and Medical Center.

Dr. Mark Preul and Dr. Alyssa Panitch have found in a study that injection of an engineered hydrogel made up mainly of hyaluronic acid (a naturally-occurring body substance) into the spinal cord injury site decreases scarring, and promotes a realignment of the spinal cord fibres around the injury site.

The hyaluronic acid, which forms a scaffold-like configuration may help to structurally stabilize the spinal cord injury site.

The researchers traced cells in the brain stem after injury, and found much higher levels in the hydrogel treated animals as compared to animals that did not receive the treatment, and approached nearly normal levels.

Treated animals had higher functional scores than their non-treated counterparts.

“Spinal cord injury is devastating to civilian and military populations – especially to the young. There has been little progress toward paradigms of regeneration and few results that show real, sustained functional recovery. We’ve been so pre-occupied with regeneration, but that is a highly complicated and difficult to define goal. This project is a synergy of neurosurgeons and bioengineers that attempts repair of the SCI lesion cavity using a tissue-engineering biomaterials approach,” says Preul.

He added that the team aimed at finding ways to structurally allow the body to better heal itself.

“In this project we did not add anything to the hyaluronic acid. It may be that adding growth factors or cells into the gel matrix may allow even better results,” he said.

Preul said that the results show “we may be on a practical path that can give hope to the many people who suffer this sort of injury.”

The work was presented at the Annual Meeting of the American Association of Neurological Surgeons in San Diego where it won the Synthes Prize for Spine Research. (ANI)

Bacteria with tiny projections can make efficient fuel cells

Washington, September 7 (ANI): A team of scientists has isolated bacteria with large numbers of tiny projections called pili, which were more efficient at transferring electrons to generate power in fuel cells than bacteria with a smooth surface.

The team was led by Professor Derek Lovley from the University of Massachusetts, US.

The researchers isolated a strain of Geobacter sulfurreducens, which they called KN400 that grew prolifically on the graphite anodes of fuel cells.

The bacteria formed a thick biofilm on the anode surface, which conducted electricity.

The researchers found large quantities of pilin, a protein that makes the tiny fibres that conduct electricity through the sticky biofilm.

“The filaments form microscopic projections called pili that act as microbial nanowires,” said Professor Lovley.

“Using this bacterial strain in a fuel cell to generate electricity would greatly increase the cell’s power output,” he added.

The pili on the bacteria’s surface seemed to be primarily for electrical conduction rather than to help them to attach to the anode. Mutant forms without pili were still able to stay attached.

Microbial fuel cells can be used in monitoring devices in environments where it is difficult to replace batteries if they fail, but to be successful, they need to have an efficient and long-lasting source of power.

According to Professor Lovley, G. sulfurreducens strain KN400 might be used in sensors placed on the ocean floor to monitor migration of turtles. (ANI)

Crabs, shrimp’s shells pave way for natural material to repair severed nerves

Washington, June 20 (ANI): Researchers at the University of Washington have found that mixing chitosan, found in the shells of crabs and shrimp, with an industrial polyester creates a promising new material for the tiny tubes that support repair of a severed nerve, and could serve other medical uses.

The researchers say that the hybrid fibre combines the biologically favourable qualities of the natural material with the mechanical strength of the synthetic polymer.

“A nerve guide requires very strict conditions. It needs to be biocompatible, stable in solution, resistant to collapse and also pliable, so that surgeons can suture it to the nerve. This turns out to be very difficult,” said Miqin Zhang, a UW professor of material science and engineering and lead author of a paper now available online in the journal Advanced Materials.

The researchers combined polycaprolactone-a strong, flexible, biodegradable polyester commonly used in sutures-with chitosan at the nanometre scale by first using a technique called electrospinning, and then weaved the fibres together.

Zhang and colleagues reveal that the resulting material had a texture similar to that of the nano-sized fibres of the connective tissue that surrounds human cells.

They highlight the fact that the two materials are different and are difficult to blend, but proper mixing is crucial because imperfectly blended fibres have weak points.

The team tested a guide made from the chitosan-polyester blend against another biomaterial under study, polylacticcoglycolic acid, and a commercially available collagen guide.

Of the three materials, the chitosan-polyester weave showed the most consistent performance for strength, flexibility and resistance to compression under both dry and wet conditions.

According to the researchers, under wet conditions, similar to those inside the body, the chitosan-polyester blend required twice as much force to push the tube halfway shut as the other biomaterial, and eight times as much force as the collagen tube.

Zhang said that the new material, though showed promise for nerve guides, might also work well for wound dressings, heart grafts, tendons, ligament, cartilage, muscle repair, and other biomedical applications. (ANI)

Scientists create soft and tough fibres that closely resemble biological tissue

Washington, May 16 (ANI): A group of Australian and Korean researchers have successfully used a robust network of DNA strands and carbon nanotubes to create supersoft sponge-like material whose mechanical properties closely resemble those of biological soft tissues.

Lead researchers Geoffrey M. Spinks and Seon Jeong Kim consider their team’s work to be a significant advance because it takes scientists a step closer to synthetically making implant materials that will closely emulate their natural counterparts-such as tendons, muscles, arteries, and skin or other organs.

Because many biological tissues are regularly subjected to intense mechanical loads, it is also important that the implant material have comparable elasticity in order to avoid inflammation. At the same time, the material must be very strong and resilient, or it may give out.

The researchers say that the materials they have made are as elastic as the softest natural tissues, while simultaneously derive great strength from the robust DNA links used for their creation.

They further reveal that an additional advantage is the electrical conductivity of the new material, which can thus also be used in electrodes for mechanical actuators, energy storage, and sensors.

A research paper describing this work has been published in the journal Angewandte Chemie. (ANI)

Just add titanium for ‘super-tough’ spider silk

London, May 2 (ANI): A team of scientists has determined that by adding the metal titanium, spider silk can be made super tough, in fact 10 times as hard to snap.

The team included Seung-Mo Lee and Mato Knez at the Max Planck Institute of Microstructure Physics in Halle, Germany.

The scientists fired beams of ionised metal compounds at lengths of silk from the orb-weaving spider Araneus diatematus using a technology called atomic layer deposition (ALD).

As well as coating each silk fibre in a fine metal oxide, some metal ions penetrated the fibre.

They tried zinc, aluminium and titanium compounds, all of which improved the mechanical properties of the silk.

“With all three metals, the fibres can hold three to four times as much weight,” said Knez.he fibres also become stretchier, so that their toughness – the energy needed to break a strand – rises even more.

“The work needed to break the fibre rises tenfold with titanium, ninefold with aluminium and fivefold with zinc,” said Knez.

The team believes that the metals are reacting with the spider silk’s protein structure, forming strong covalently bonded cross-links between the amino acid polymers within the silk.

Normally, these polymers are only linked by weaker hydrogen bonds.

Spider silk is not a practical engineering material, but materials scientists are trying to produce artificial fibres that mimic its properties.

If they succeed, the result could be super-tough textiles.

According to Knez, the technique has more immediate potential for toughening other biomaterials such as collagen.

“Mechanically improving collagen using our technique might open several new possible applications, like artificial tendons,” he said. (ANI)

Henry VIII’s tapestry ‘re-weaved’

London, Apr 10 (ANI): A 500-year-old tapestry commissioned by Henry VIII has been returned to its colourful glory, courtesy an exhibition that uses digital technology.

The exhibition, which has opened in London, allows visitors to see the vibrant colours originally woven into the fabrics at the Henry VIII’s Tapestries Revealed exhibition with the help of light beams.

It has taken six years of research to ‘virtually restore’ the faded threads for the Hampton Court Palace show.

The exhibition is part of a range to mark 500 years since the accession of the 16th Century king.

The tapestry is part of the Story of Abraham Series which was woven to celebrate the birth of Henry VIII’s son, reports The BBC.

Researchers from the University of Manchester and Historic Royal Palaces spent years to calculate how much colour had faded from its fibres. The fabric’s delicate nature means the calibrated beams of light can only be used in five short bursts a day.
Kathryn Hallett, from the Historic Royal Palaces, said: “This project, the first ever ‘virtual restoration’ of a tapestry, will show how these magnificent works of art would have dazzled visitors to Henry VIII’s Great Hall at Hampton Court Palace 500 years ago.”

The piece originally cost 2,000 pounds in 1537 and took three years to be completed by master craftsmen who made cloths from wool and silk, interlaced with gold and silver thread. (ANI)

Chimps create “fishing rods” to hunt termites

London, March 4 (ANI): Scientists have discovered that chimpanzees can fashion plant stems into tools that resemble fishing rods, in order to scoop termites out of their nests.

According to a report by BBC News, a team working in the Republic of Congo discovered that chimps are crafting brush-tipped “fishing rods” with the help of their teeth.

As observed in recorded video, the probes’ frayed ends helped the chimpanzees to collect more termites.

“They have invented a way to improve their termite-fishing technique,” said lead researcher Crickette Sanz, from the Max Planck Institute of Evolutionary Anthropology in Leipzig, Germany.

Previous studies have suggested that wild chimpanzees use brush-tipped tools to fish for termites.

The chimps seem to understand the function of the tool and its importance in gathering termites.

But, until now, it has been unclear whether this was a specially crafted design feature or whether the frayed edges were a by-product of repeated tool use.

Using remote cameras to film the chimps as they sought out their insect snacks, the scientific team was able to find an answer.

“We found that in the Goualougo Triangle in the Republic of Congo, the chimpanzees were modifying their termite-fishing tools with a special brush tip,” Dr Sanz told the BBC.

To make their rods, the chimps first picked some stems from the Marantaceae plant and plucked off the leaves.

“They then pulled the herb stems through their teeth, which were partially closed, to make the brush and they also attended to the brush by sometimes pulling apart the fibres to make them better at gathering the termites,” Dr Sanz added.

Further research revealed that a stem with a frayed tip collected 10 times more termites than a pointed probe.

According to Dr Sanz, “The chimps seem to understand the function of the tool and its importance in gathering termites.”

So far, the team have only found this behaviour in chimps in the Goualougo Triangle.

The apparent absence of this in populations in eastern and western Africa suggests that it is not an innate skill found in all chimpanzees.

Instead, it seems that the Goualougo primates are learning the crafting techniques from other chimps.

“Large areas of central Africa have been largely unstudied and so there are many populations that could have examples of complex tool use that we just do not know about,” Dr Sanz said. (ANI)