Knowledge Update

London, May 18 (IANS) Based on the "liquid wire" technique in spider webs, a team of international researchers has created composite fibers which extend like a solid and compress like a liquid.

Pulling on a sticky thread in a garden spider's orb web and letting it snap back reveals that the thread never sags but always stays taut, even when stretched to many times its original length.

This is because any loose thread is immediately spooled inside the tiny droplets of watery glue that coat and surround the core gossamer fibres of the web's capture spiral.

The study, which was carried out by researchers from the University of Oxford and the Pierre and Marie Curie University, Paris, was published by the University of Oxford in the journal Proceedings of the National Academy of Sciences.

"Surprisingly, each drop packs enough punch in its watery skins to reel in loose bits of thread. And this winching behaviour is used to excellent effect to keep the threads tight at all times, as we can all observe and test in the webs in our gardens," said Prof. Fritz Vollrath form the University of Oxford.

The novel properties observed and analysed by the researchers rely on a subtle balance between fibre elasticity and droplet surface tension. The team was also able to recreate this technique in the laboratory using oil droplets on a plastic filament.

This artificial system behaved just like the spider's natural winch silk, with spools of filament reeling and unreeling inside the oil droplets as the thread extended and contracted, according to the study.

"Our bio-inspired hybrid threads could be manufactured from virtually any components. These new insights could lead to a wide range of applications, such as micro-fabrication of complex structures, reversible micro-motors, or self-tensioned stretchable systems," said Herve Elettro, the first author of the study and a doctoral researcher from the Pierre and Marie Curie University.​

​London, May 18 (IANS) A study has found a new link between inflammation and cell division -- two of the most important processes in the human body whose accurate control is a holy grail for scientists researching the prevention of infection, inflammatory disease and cancer.

"This is an exciting discovery: for the first time we find a link between the system which regulates how cells divide and the basis of some of medicine's most intractable diseases," said Mike White, who led the joint study by the University of Manchester and Liverpool. 

Inflammatory signals produced by a wound or during an infection can activate a protein called Nuclear Factor-kappaB (NF-kB), which controls the activity of genes that allow cells to adapt to the situation.

Incorrect control of NF-kB is associated with inflammatory diseases, such as Crohn's disease, psoriasis and rheumatoid arthritis. It has also been linked with ageing and some cancers.

A key way in which human cells adapt to signals in their environment is by dividing to produce new cells through a repeating pattern of events, called the cell cycle. A cell first makes copies of its DNA, in a stage known as the DNA synthesis phase, and then divides into two daughter cells.

The cell cycle is controlled by a family of proteins called E2 factors, which control the start of the new cell's DNA synthesis phase.

The study published recently in the journal eLife showed that the NF-kB and E2 factors bind to each other in the cell. This controls the level of the NF--kB signal, which is enhanced just before DNA synthesis, but reduced during the DNA synthesis phase.

Scientists also showed that signals which activate NF-kB can change the timing of cell division.

The findings suggest that direct interactions between E2 factor proteins and NF-kB enable cells to decide whether to divide and determine how they react in different ways to inflammatory signals.​

New York, May 18 (IANS) A skull condition that has been believed to be a thing of the past due to poor diet among our ancestors not only still exists, but is fairly common among modern humans, new research has found.

The skull condition called cribra orbitalia (CO) makes bone inside the eye sockets porous. It is not known to cause any adverse health effects, but is generally regarded as being caused by iron deficiency anemia.

The condition has traditionally been used by anthropologists to assess diet and health in prehistoric populations. 

For example, the presence of CO could tell researchers that a population was not getting a sufficiently varied diet.

"But there's been a lot of debate about the prevalence of CO in modern populations, with some saying it had effectively disappeared," said study co-author Ann Ross from North Carolina State University in the US.

"We wanted to know if CO was still extant and, if so, how common it is in modern populations, relative to earlier eras," Ross noted.

For this study, the researchers looked at modern, historic and prehistoric human remains from South Africa, North America.

Altogether, the researchers evaluated data on 844 skulls -- 245 prehistoric, 381 historic (as recent as the early 20th century) and 218 modern.

The researchers found that CO was not only present in modern populations, but that it was not even uncommon.

For example, the researchers found that two of the five modern North American juvenile skulls evaluated in the study - 40 percent - had CO. And 15 of the 60 South African juveniles evaluated in the study - 25 percent - had CO.

Overall, the researchers found that 12.35 percent of modern North Americans and 16.8 percent of modern South Africans, across all age groups, had CO.

Both rates are higher than their historic counterparts. Only 2.23 percent of historic South African skulls evaluated had CO, and only 6.25 percent of historic North American skulls. Even the prehistoric North American skulls had a lower rate of CO, at 11.86 percent.

The study was published online in the journal Clinical Anatomy.

"We think the increased prevalence of CO in the modern skulls may be due to intestinal parasites in some populations and iron-poor diet," Ross noted.

"These findings drive home the fact that disadvantaged socioeconomic groups, and parts of the developing world, are still struggling with access to adequate nutrition," Ross added.​

​Toronto, May 17 (IANS) Children and young adults take a long time to fully recover from any brain injury occurring while playing games, says a study.

The findings of the Canadian study indicate that those in the age group of eight to 16 are not only vulnerable to concussions but -- because their brain is still developing -- they are neurologically more fragile than adults for performing tasks that require cognitive motor integration following a concussion.

After a concussion, young athletes usually rejoin their teams in a few weeks if they do not have any active symptoms. 

“However, they may take up to two years to fully recover from the injury before they can play as skillfully as their teammates with no history of concussion," said Lauren Sergio from York University in Canada.

"Performing motor tasks, guided by what we see, is crucial in skill-based activities such as sports," Sergio added in the paper published in the journal Concussion. 

The team analysed the prolonged difficulty in cognitive-motor integration in 50 children and adolescents with a history of concussion and were compared with 49 who have never had a concussion.

The participants in both the groups were asked to perform two different tasks on a dual-touchscreen laptop. 

In one task, target location and motor action were aligned. In the other task that tested cognitive-motor integration, the required movement was not aligned with the guiding visual target and required simultaneous thinking for successful performance.

"We noticed significant difficulty in completing the tasks among those with concussion history," said lead author Marc Dalecki.

"In fact, it took many of the children two years after the concussion to have a similar performance on the task as children who did not have a history of concussion," Dalecki noted.

"The current return to sport assessment doesn't test to see if the injured person has regained this ability. Because of this, often children and youth who have had a concussion end up returning to normal activities before they are fully recovered which makes them more vulnerable to another concussion," Sergio said.​

London, May 17 (IANS) Germs could play a role in the development of Type-1 diabetes by triggering the body's immune system to destroy the cells that produce insulin, suggests new research.

Type-1 diabetes is a very serious and hard to treat condition affecting mainly young people and children.

Previous research has shown that killer T-cells -- a type of white blood cell that normally protects us from germs -- play a major part in type-1 diabetes by destroying insulin producing cells, known as beta cells.

"The study identified part of a bug that turns on killer T-cells so they latch onto beta cells. This finding sheds new light on how these killer T-cells are turned into rogues, leading to the development of type-1 diabetes," said lead author Andy Sewell, professor at Cardiff University in Britain.

These killer T-cells are strongly activated by some bacteria.

During type-1 diabetes, the T-cells attack pancreatic beta cells -- which make the insulin essential for control of blood sugar levels.

When beta cells are destroyed, patients have to inject insulin every day to remain healthy.

"Killer T-cells are extremely effective at killing off germs, but when they mistakenly attack our own tissues, the effects can be devastating," Sewell said.

The research, published in the Journal of Clinical Investigation, provides a first ever glimpse of how germs might trigger killer T-cells to cause type-1 diabetes, but also points towards a more general mechanism for the cause of other autoimmune diseases.

"Finding the cellular mechanisms behind the development of autoimmune diseases, such as type-1 diabetes, could lead to treatments that help us lead longer, healthier lives," David Cole from Cardiff University noted.​

New Delhi, May 17 (IANS) South Asians number the highest among patients suffering from hypertension, doctors said on Tuesday. Hypertension leads to conditions like brain stroke and heart attacks, among others, and regular medication and check-up is needed to control it.

According to the doctors, the factors triggering hypertension among the South Asians include stress and the poor habits of taking 'gutka', 'kimam', 'paan' or 'naswar'.

"Studies show that stroke-related deaths are higher among the South Asian people than the White people, all because of hypertension. We South Asians develop high blood pressure, diabetes or high cholesterol much more easily in comparison to the people of West," said Vipul Gupta, head of Neurovascular Intervention Centre at Medanta.

Noting that hypertension is the prime reason behind heart and brain strokes, Gupta said because of ignorance the condition reaches a stage when blood vessels are strained, including the ones leading to the heart, making it much tougher to circulate blood in the body.

"This strain can damage the blood vessels, causing them to become harder and narrower, a condition called atherosclerosis. This makes a blockage more likely, which can cause a stroke or transient ischaemic attack (TIA, sometimes called a mini stroke)," said Satnam Singh Chhabra, Head Neuro and Spine Surgeon, Sir Ganga Ram Hospital.

According to these experts, the relationship between blood pressure (hypertension) and risk of stroke is strong. The higher is the blood pressure, the greater is the risk of stroke. 

Currently, over 16 lakh Indians suffer from stroke annually. 

Suggesting regular check-ups as the best way to diagnose hypertension, Chhabra said: "The good news is that many clinical trials have documented that drug treatment of hypertension prevents stroke and that anti-hypertensive drug treatment reduced the risk of strokes by 32 percent compared to no drug treatment".

"Medication and other lifestyle changes are required to control high blood pressure. Patients should understand that they should be very regular in taking medications, getting the blood pressure checked and visiting doctors to reduce the chances of organ damage due to hypertension," Chhabra said.​

Washington, May 16 (IANS) In a bid to develop “magnetoshells” to “growable interplanetary habitats to take humans to Mars”, the US space agency has selected eight technology proposals that can transform future aerospace missions by building efficient aerospace systems.

Awards under phase II of the NASA Innovative Advanced Concepts (NIAC) programme can be worth as much as $500,000 for a two-year study.

It will allow proposers to further develop concepts funded by NASA for Phase I studies that successfully demonstrated initial feasibility and benefit.

“The NIAC programme is one of the ways NASA engages the US scientific and engineering communities by challenging them to come up with some of the most visionary aerospace concepts,” said Steve Jurczyk, associate administrator of NASA’s Space Technology Mission Directorate in Washington, DC.

This year’s phase II portfolio addresses a range of leading-edge concepts, including an interplanetary habitat configured to induce deep sleep for astronauts on long-duration missions.

It also has plans for a highly efficient dual aircraft platform that may be able to stay aloft for weeks or even months at a time.

Phase II includes a method to produce “solar white” coatings for scattering sunlight and cooling fuel tanks in space down to 148 degree Celsius below zero with no energy input needed.

NASA selected eight projects through a peer-review process that evaluated innovativeness and technical viability.

“Phase II decisions are always challenging, but we were especially challenged this year with so many successful Phase I studies applying to move forward with their cutting-edge technologies,” added Jason Derleth, the NIAC program executive at NASA headquarters.

“Whether it's tensegrity habitats in space, new ways to get humans to Mars or delicate photonic propulsion, I am thrilled to welcome these innovations and their innovators back to the programme,” Derleth noted in a NASA statement.

All projects are still in the early stages of development, most requiring 10 or more years of concept maturation and technology development before use on a NASA mission.​

​Melbourne, May 16 (IANS) The first map of Australia, produced by Dutch explorers in the 17th century, arrived in Melbourne on Monday for expert analysis, as historians look to preserve the priceless document.

The map of New Holland, the name given to the Australian mainland by famous seafarer Abel Tasman, is the first published record of the previously unexplored continent in the Dutch language, Xinhua news agency reported.

Created by Dutch East India Company cartographer Joan Blaeu, the 1663 map has formed basis of all subsequent mapping of Australia.

But since uncovered in a Swedish storage facility six years ago and acquired by National Library of Australia in 2013, historians have identified that the priceless artefact is in serious decay.

Subsequently, the National Library of Australia has launched a conservation effort to preserve the important document as an historical record for the benefit of future generations.

Senior Paper Conservator from the University of Melbourne, Libby Melzer, explained that the map had deteriorated due to the cartographer's choice to use blue-green paint, believed to be verdigris, to highlight the Australian coastline and other distinguishing features.

"Derived from copper and typically exposed to wine vapours to achieve its vibrant colour, verdigris is chemically unstable and has darkened and corroded the surrounding paper, eating through it entirely in some places," Melzer, from the university's Grimwade Centre for Cultural Material Conservation, said in the statement.​

Melbourne, May 16 (IANS) Using space dust, researchers from Monash University here have made a surprising discovery about the chemistry of Earth's atmosphere 2.7 billion years ago, thus challenging the accepted view that Earth's ancient atmosphere was oxygen-poor.

The ancient Earth's upper atmosphere contained about the same amount of oxygen as today and that a methane haze layer separated this oxygen-rich upper layer from the oxygen-starved lower atmosphere, the team noted.

“Using cutting-edge microscopes, we found that most of the micrometeorites (space dust) had once been particles of metallic iron - common in meteorites - that had been turned into iron oxide minerals in the upper atmosphere, indicating higher concentrations of oxygen than expected," explained Andrew Tomkins from Monash University.

He explained how the team extracted micrometeorites from samples of ancient limestone collected in the Pilbara region in western Australia and examined them at the Monash Centre for Electron Microscopy (MCEM) and the Australian Synchrotron.

“This was an exciting result because it is the first time anyone has found a way to sample the chemistry of the ancient Earth's upper atmosphere,” Tomkins noted in a paper appeared in the journal Nature.

Co-researcher Matthew Genge from Imperial College London performed calculations that showed oxygen concentrations in the upper atmosphere would need to be close to modern day levels to explain the observations.

“This was a surprise because it has been firmly established that the Earth's lower atmosphere was very poor in oxygen 2.7 billion years ago. How the upper atmosphere could contain so much oxygen before the appearance of photosynthetic organisms was a real puzzle," Genge noted.

The results suggest the Earth at this time may have had a layered atmosphere with little vertical mixing, and higher levels of oxygen in the upper atmosphere produced by the breakdown of carbon dioxide by ultraviolet (UV) light.

A possible explanation for this layered atmosphere might have involved a methane haze layer at middle levels of the atmosphere.

The methane in such a layer would absorb UV light, releasing heat and creating a warm zone in the atmosphere that would inhibit vertical mixing.

“By studying fossilised particles of space dust the width of a human hair, we can gain new insights into the chemical makeup of Earth's upper atmosphere, billions of years ago,” Tomkins pointed out.

The next stage for the team will be to extract micrometeorites from a series of rocks covering over a billion years of Earth's history in order to learn more about changes in atmospheric chemistry and structure across geological time.

“We will focus particularly on the great oxidation event, which happened 2.4 billion years ago when there was a sudden jump in oxygen concentration in the lower atmosphere,” the authors noted.

Sydney, May 17 (IANS) A study released on Tuesday has found that a high concentration of coal dust can quickly kill coral on Australia's Great Barrier Reef.

The research by the Australian Institute of Marine Science discovered coal dust could also slow the growth rate of seagrasses and fish, Xinhua news agency reported.

"Corals exposed to the highest concentrations of coal dust died within two weeks," author Kathryn Berry said.

"Corals exposed to lower concentrations of coal lasted longer, but most of them also died after four weeks of exposure."

She noted that while some fish and seagrass died from coal dust exposure, it mostly stunted their growth by half compared to clean water.

The study found coal dust entered the marine environment at loading and storage facilities, or when it is blown into the sea during transport.

Researches also noted a shipping disaster as a possible risk to the reef.

"Risks to the Great Barrier Reef posed by large coal spills depend on the probability of an accident and the potential impacts to marine life," author Andrew Negri said.

"While the likelihood of a major spill on a coral reef or seagrass meadow is low, we are now beginning to understand the likely consequences."

Researchers hope the results will send a message to coal shipping companies in Australia and across the world.​