Knowledge Update

​Tokyo, July 17 (IANS) While it is widely accepted that an asteroid impact caused the mass extinction of dinosaurs and other life forms, researchers have been stumped by the process of how. In other words, they had figured out the killer, but not the murder weapon.

A new study has now said that when the asteroid hit the oil-rich region of Yucatan Peninsula in Mexico, a massive amount of soot was ejected which then spread globally, causing global cooling, drought and limited cessation of photosynthesis in oceans.

This could have been the process that led to the mass extinction of dinosaurs, said the research team from Tohoku University and the Japan Meteorological Agency's Research Institute.

The asteroid, also known as the Chicxulub impactor, hit Earth some 66 million years ago, causing a crater more than 180 km wide.

Professor Kunio Kaiho from Tohoku University and his team analysed sedimentary organic molecules from two places -- Haiti, which is near the impact site, and Spain, which is far.

They found that the impact layer of both areas have the same composition of combusted organic molecules showing high energy.

This, they believe, is the soot -- a strong, light-absorbing aerosol -- from the asteroid crash.

The results were significant because they could explain the pattern of extinction and survival.

Earlier theories had suggested that dust from the impact may have blocked the sun, or that sulphates may have contaminated the atmosphere.

But it was unlikely that either phenomenon could have lasted long enough to have driven the extinction, the researchers noted.

According to their study, when the asteroid hit the region, the massive amount of soot had caused a prolonged period of darkness which led to a drop in atmospheric temperature.

The soot aerosols caused colder climates at mid-high latitudes, and drought with milder cooling at low latitudes on land.

This in turn led to the cessation of photosynthesis in oceans in the first two years, followed by surface-water cooling in oceans in subsequent years.

This rapid climate change is believed to be behind the loss of land and marine creatures over several years, suggesting that rapid global climate change can and did play a major role in driving extinction.

The study was published in the journal Scientific Reports.​

New York, July 16 (IANS) Turtles developed shells as a tool for burrowing underground to escape harsh climatic conditions, a study has found, contradicting the traditional belief that they used their shells for their protection.

The study was conducted on new fossil material, a 15 cm long specimen of the 260- million-year-old, partially shelled, proto turtle or stem turtle, Eunotosaurus Africanus from the Karoo Basin of South Africa, which indicated that the initiation of rib broadening was an adaptive response to fossoriality. 

Numerous fossorial animal -- one that is adapted to digging and life underground such as the badger -- correlates are expressed throughout Eunotosaurus' skeleton.

These stem turtles indicate that the shell did not evolve for protection, rather adaptation related to digging was the initial impetus in the origin of the shell.

"The earliest beginnings of the turtle shell was not for protection but rather for digging underground to escape the harsh South African environment where these early proto turtles lived," said lead author Tyler Lyson, Paleontologist Denver Museum of Nature & Science in Colorado, US.

The adaptations related to fossoriality likely facilitated movement of stem turtles into aquatic environments early in the groups' evolutionary history, and this ecology may have played an important role in stem turtles surviving the Permian/Triassic extinction event that occurred about 252-million-years ago, said the paper published in the journal Current Biology.

Further, the developmental and fossil data showed that one of the first steps toward the shelled body plan was broadening of the ribs.

The distinctly broadened ribs -- that play a crucial role in ventilating the lungs and are used to support the body during locomotion -- has a serious impact on both breathing and speed in these quadrupedal animals. 

These broadened ribs stiffen the torso, which shortens an animals stride length and slows it down, interfering with breathing.

"We knew from both the fossil record and observations how the turtle shell develops into modern turtles that one of the first major changes toward a shell was the broadening of the ribs," Lyson added.

The broad ribs of Eunotosaurus provide an intrinsically stable base on which to operate a powerful forelimb digging mechanism.

Most of these features are widely distributed along the turtle stem and into the crown clade, indicating the common ancestor of Eunotosaurus and modern turtles possessed a body plan significantly influenced by digging, the researchers concluded.​

​New York, July 16 (IANS) Soon after technology giant Apple reported its first-ever quarterly drop in iPhone sales in April, a new report has found that "the outlook for iPhone demand keeps getting murkier" as other leading smartphone brands like Samsung make inroads in the market.

The number of iPhone units sold would tumble 12 per cent from 2015 and the upcoming iPhone 7 would be "a marginal cycle at best", New York Post reported, quoting a Wall Street analyst on Friday.

Recently, retail data insights and consulting business Kantar Retail reported that Samsung’s Galaxy 7 line of smartphones grabbed 16 per cent of total sales in the US during the three months ended May 31, exceeding the 14.6 per cent of sales for the iPhone 6s.

As the momentum of the 6s has slowed down, investors are worried about iPhone 7 that the device might not be a significant upgrade.

Mark Moskowitz of Barclays forecast that this year’s iPhone unit sales would total 203.7 million down from 231.5 million last year. 

The report by Kantar not only mentioned the threat to Apple but to its biggest rival Samsung as well by the increasing competition from lower-priced rivals, most notably China-based Xiaomi and Huawei.

“Apple and Samsung should stop worrying so much about each other and take a look around them,” Kantar analyst Lauren Guenveur was quoted as saying, noting that Huawei aims to overtake Apple as the second-largest smartphone seller by 2020.

Guenveur also noted that “rumours are swirling” that Google will soon introduce a handset of its own.

Earlier this week, research firm IDC said Apple’s share of the worldwide PC market shrank to 7.1 per cent from 7.4 per cent as customers hold out for a long-awaited refresh to the MacBook Pro line.

Apple is slated to give an update on recent demand when it reports results on July 26.​

New York, July 14 (IANS) A gene associated with Alzheimer's disease may shrink brain structures and lower thinking skills as early as in childhood, decades before the illness actually appears, says a research.

The findings showed that children with epsilon(E)4 variant of the apolipoprotein-E gene showed differences in their brain development compared to children with E2 and E3 forms of the gene and were more likely to develop Alzheimer's disease.

In such children the size of the hippocampus -- a brain region that plays a role in memory -- was found to be approximately 5 per cent smaller.

Specifically, the children as small as of age three showed up to 50 per cent lower scores on tests of executive function, working memory and attention. 

Each person receives one copy of the gene (E2, E3 or E4) from each parent, so there are six possible gene variants: E2E2, E3E3, E4E4, E2E3, E2E4 and E3E4, the researchers explained.

Further, children younger than eight and with the E4E4 genotype typically had lower measures on a brain scan as well as had lower scores on a test on memory and thinking skills. 

"Studying these genes in young children may ultimately give us early indications of who may be at risk for dementia in the future and possibly even help us develop ways to prevent the disease from occurring or to delay the start of the disease," said study author Linda Chang from the University of Hawaii in Honolulu, US.

However, children older than 8 with these two genotypes had similar and normal test scores compared to the other children.

"These findings mirror the smaller volumes and steeper decline of the hippocampus volume in the elderly who have the E4 gene," Chang added in the work published online in the journal Neurology.

For the study, the team analysed 1,187 children from ages three to 20 years who had genetic tests and brain scans and as well as took tests of thinking and memory skills. 

The children had no brain disorders or other problems that would affect their brain development, such as prenatal drug exposure.​

​Beijing, July 14 (IANS) Playing action-based video games may boost the players' ability to coordinate visual information with their motor control -- a skill critical to many real-world behaviours including driving, says new research.

The findings showed that playing some types of video games can confer benefits for specific visual abilities such as sensitivity to contrast and visuo-spatial attention. 

"The research shows that playing easily accessible action video games can be a cost-effective tool to help people improve essential visuomotor-control skills used for driving," said lead researcher Li Li, Associate Professor at New York University in Shanghai, China.

Experienced action gamers showed much greater precision in keeping to their lane and showed less deviation from centre in the face of increasing headwinds, when compared to the participants with little to no action video game experience.

To establish a causal link between action video games and visuomotor control skills, the team recruited participants who had no action video gaming experience to take part in a training study.

They then compared the visuomotor abilities of players who had played at least 5 hours per week over the previous 6 months to participants who had negligible action video game experience.

The participants were randomly assigned to either an action video game group or a control group, and they completed a total of 10 1-hour training sessions.

The data showed that playing "Mario Kart," a fast-paced action video game, improved participants' visuomotor control skills on the target dot task after five hours of training. 

Those who played "Roller Coaster Tycoon", a non-action strategy game, showed no such improvement over time.

For novice drivers, training with driving video games may be more helpful, the researchers suggested in the work published in the journal Psychological Science. 

​New York, July 14 (IANS) As smartphones become centre of our lives, a new study says that we touch our smartphones 2,617 times a day on average -- and the heaviest smartphone users are clicking, tapping or swiping on their devices 5,427 times a day.

The research firm Dscout, which specialises in consumer reactions to products, recruited 94 Android device users and installed special software on their smartphones. 

The tool tracked each user's “interaction” over five days, all day. 

"By every interaction, we mean every tap, type, swipe and click. We're calling them touches," commented Dscout in a blog post on Thursday. 

Long usage sessions are rare-mostly Netflix and reading. In general, people prefer lots of little sessions with breaks in between.

Eighty seven per cent of participants checked their phones at least once between midnight and 5 a.m.

Messaging and social media apps totaled 26 per cent and 22 per cent of interactions respectively, while internet search browsers comprised 10 per cent, the post noted. ​

New York, July 14 (IANS) A new, minimally invasive procedure could improve treatment for many patients with a common eye disease, without the potential side effects and cost of the current standard of care -- a cornea transplant, new research has found.

In the study involving patients suffering from Fuchs endothelial dystrophy (FED), the researchers showed that removing a few square millimetres of a single layer of cells on the inside of the cornea allowed rejuvenation of the surrounding tissue, without the need for a corneal transplant. 

This simple procedure restored clear vision to three out of four patients suffering from FED, the most frequent cause for corneal transplantation in the US.

"It's quick, inexpensive and it spares patients from having someone else's cells in their eyes, which requires local immunosuppression," said lead researcher Kathryn Colby, Professor at the University of Chicago.

The proof-of-concept study was published in the journal Cornea.

Over the past two years while at Harvard Medical School, Colby performed the new procedure, known as Descemet stripping.

Descemet stripping involves removing a small patch of the corneal endothelium (the pumping cells that stop working in FED) attached to an underlying layer (the Descemet membrane). 

In patients with FED, water accumulates in the cornea, the clear front window of the eye, because of the dysfunction of the pumping cells, causing reduced vision, glare and haloes. 

If left untreated, the condition progresses to painful blindness.

Removal of the central dysfunctional cells enables healthier peripheral cells to migrate to the centre of the cornea, where they re-establish pumping capacity and removal of fluid from the layers above. This gradually restores clear vision.

"Although Descemet stripping is a relatively simple procedure, its potential is revolutionary," Colby said.​

​Buenos Aires, July 14 (IANS) Researchers in Argentina have excavated the fossil of a new carnivorous dinosaur that lived around 90 million years ago, a media report said on Thursday.

The 26-feet (8 metres) long dinosaur had two-fingered small forearms that were merely 2 feet (60 cm) long, scientists said in a news conference after the team published the discovery in the PLOS ONE journal, Xinhua news agency reported.

The dinosaur belonged to the theropods (beast footed) -- a family that also included Tyrannosaurs and Velociraptors, the scientists said.

The dinosaur was named Gualicho Shinyae, a combination of the name of an evil spirit Gualichu -- worshipped by the local Tehuelche community in the Patagonia region and Akiko Shinya, the scientist who first discovered the dinosaur in southern Rio Negro Province.

The dinosaur was unearthed in 2007, but difficulties postponed the team's analysis.

The fossil was currently being conserved at the Patagonian Museum of Natural Sciences in the city of General Roca and the Carlos Ameghino Provincial Museum in Cipolletti, both in Rio Negro Province.

​London, July 15 (IANS) Scientists have found a new method of creating human stem cells which could solve the big problem of the large-scale production needed to fully realise the potential of these remarkable cells for understanding and treating disease.

The discovery has been made by a team of scientists at the University of Nottingham in Britain, Uppsala University and GE Healthcare in Sweden.

"By using a protein derived from human blood called Inter-alpha inhibitor, we have grown human pluripotent stem cells in a minimal medium without the need for costly and time-consuming biological substrates,” said first author Sara Pijuan-Galito from Uppsala University.

Inter-alpha inhibitor is found in human blood at high concentrations, and is currently a by-product of standard drug purification schemes.

"The protein can make stem cells attach on unmodified tissue culture plastic, and improve survival of the stem cells in harsh conditions,” Pijuan-Galito said.

"It is the first stem cell culture method that does not require a pre-treated biological substrate for attachment, and therefore, is more cost and time-efficient and paves the way for easier and cheaper large-scale production," Pijuan-Galito explained.

Human pluripotent stem cells are undifferentiated cells which have the unique potential to develop into all the different types of cells in the body. 

With applications in disease modelling, drug screening, regenerative medicine and tissue engineering, there is already an enormous demand for these cells, which will only grow as their use in the clinic and by the pharmaceutical industry increases.

However, production of stem cells at the scale required for optimal application in modern healthcare is currently not feasible because available culture methods are either too expensive, or reliant on substances that would not be safe for clinical use in humans.

The new research, published in the journal Nature Communications, could lead to quicker and cheaper large scale industrial production.

The work was started at Uppsala University in Sweden, and the first author, Dr Sara Pijuan-Galitó, is now continuing her work as a Swedish Research Council Research Fellow at Nottingham. Sara said: 

"This new method has the potential to save time and money in large-scale and high-throughput cultures, and be highly valuable for both basic research and commercial applications," Cecilia Anneren, who has a joint position at Uppsala University and at GE Healthcare in Uppsala, said.​

​New York, July 15 (IANS) American black bears may be able to recognise things they know in real life, such as pieces of food or humans, when looking at a photograph of the same thing in the computer, suggests new research.

"Bears can transfer learning with real objects to photographs of those objects presented on computer screens," said one of the researchers, Zoe Johnson-Ulrich from the Oakland University in the US.

The study involving a black bear called Migwan and a computer screen was part of a broader research project into the welfare of bears in captivity. 

It aimed to find out how the animals themselves rate the environment in which they are held, and the facilities, food and features provided to them. 

The goal is to assess this by presenting bears with photographs of objects. 

To do so, the research team first had to assess whether bears are in fact able to recognise images of objects and people familiar to them when these are presented to them on a touch screen.

With this in mind, the researchers tested the responses of Migwan. 

The bear was born in the wild, but was rescued at a very young age and rehabilitated due to injuries. 

She had previously received several months of training on an unrelated task using photographs of food items from her normal diet. 

In this study, Migwan was first presented with two sets of objects new to her. Her ability to recognise these later, when presented with photographs including the items she had learned, was then assessed. 

In a reverse task, she was also trained on the photographs of two different sets of objects and tested on the transfer to real objects.

It was found that Migwan was able to recognise, on a photograph, the visual features of objects or natural stimuli she already knew. It is an ability that bears share with hens, rhesus monkeys, pigeons, tortoises and horses.

The findings were published in Springer's journal Animal Cognition.

The researchers believe that the findings have important implications for the use of photographs in computerised studies involving bears, and in ultimately ensuring the welfare of captive bears.

"Bears' responses to these photographs may reflect behaviors towards real items," Jennifer Vonk who is also from Oakland University noted.​