Knowledge Update

​New York, Sep 14 (IANS) Researchers should not rely on the clinical symptoms of memory loss alone to diagnose Alzheimer's disease because there could be other indicants of the neurodegenerative disease that do not initially affect memory, says a new study.

There are more than just one symptom of Alzheimer's disease. These could be language problems, disruptive individual behaviour and personality disorder -- even judgement of someone's concept of the position of objects in space, said researchers at Northwestern University, in Evanston, of Illinois, in the US.

If it affects personality, it may cause lack of inhibition. For example, someone who was shy might one day go up to the grocery store clerk -- who is a complete stranger -- and try to hug or even kiss her. 

This all depends on what part of the brain is affected by Alzheimer's, the study said.

However, "these individuals are often overlooked in clinical trial designs and thus miss out on opportunities to participate in the experiments formulated to treat Alzheimer's", said lead author and Associate Professor Emily Rogalski at Northwestern University.

"Such individuals are often excluded because they don't show memory deficits, inspite of sharing the same disease (Alzheimer's) that's causing their symptoms," Rogalski added.

In the study, the authors identified the clinical features of individuals with primary progressive aphasia (PPA) -- a rare dementia that causes progressive declines in language abilities due to Alzheimer's disease. 

During the initial phase of PPA, memory and other thinking abilities are relatively intact. Also, PPA can be caused either by Alzheimer's disease or another neurodegenerative disease family called Frontotemporal lobar degeneration (FTLD). 

The study demonstrated that knowing an individual's clinical symptoms was not enough to determine whether PPA was due to Alzheimer's or any other neurodegenerative disease -- where progressive loss of structure or function of neurons, including death of neurons happen. 

Therefore, an amyloid positron emission tomography (PET) scan -- an imaging test -- should be taken.

PET scan tracks the presence of amyloid -- an abnormal protein whose accumulation in the brain is a hallmark of Alzheimer's. 

PET scan should be used in early life to determine the likelihood of Alzheimer's disease pathology in later life, the researchers said in the study published online in the journal Neurology. 

London, Sep 14 (IANS) On its way to assembling the most detailed 3D map ever made of our Milky Way galaxy, European Space Agency's Gaia probe has pinned down the precise position in the sky and the brightness of 1,142 million stars, astronomers working on the mission have said.

The first catalogue of more than a billion stars from Gaia satellite was published on Wednesday -- the largest all-sky survey of celestial objects to date.

The release also features the distances and the motions across the sky for more than two million stars.

"Gaia is at the forefront of astrometry, charting the sky at precisions that have never been achieved before," said Alvaro Gimenez, ESA's Director of Science.

"Today's release gives us a first impression of the extraordinary data that await us and that will revolutionise our understanding of how stars are distributed and move across our Galaxy," Gimenez said in a statement on Wednesday.

Launched in 2013 on a Soyuz-STB/Fregat-MT launch vehicle from the European Spaceport in Kourou, French Guiana, Gaia started its scientific work in July 2014. 

This latest release is based on data collected during its first 14 months of scanning the sky, up to September 2015.

"The beautiful map we are publishing today shows the density of stars measured by Gaia across the entire sky, and confirms that it collected superb data during its first year of operations," Timo Prusti, Gaia project scientist at ESA, said.

Gaia probe was launched with the aim of making the largest, most precise three-dimensional map of our galaxy by surveying more than a thousand million stars.

At its heart, Gaia contains two optical telescopes that work with three science instruments to precisely determine the location of stars and their velocities, and to split their light into a spectrum for analysis.

During its planned five-year mission, the spacecraft spins slowly, sweeping the two telescopes across the entire celestial sphere. 

As the detectors repeatedly measure the position of each celestial object, they will detect any changes in the object's motion through space.

​London, Sep 14 (IANS) Has your toddler started playing around with the touchscreen tablet, yet? It's good, if the child has, as his/her active scrolling of the screen would increase finer motor control, says a recent study.

According to the study conducted at the University of London, early touchscreen use, in particular active scrolling, correlated with increased fine motor skills.

Researcher Tim J. Smith of Birbeck at University of London set up an online survey for parents to answer questions about their children's touchscreen use.

This included questions about whether the toddlers used touchscreens, when they first used one besides how often and how long they used them. 

The survey also included specific questions to assess the development of the children, such as the age that they first stacked blocks -- which indicates fine motor skills -- or the age they first used two-word sentences -- which indicates language development.

During the study, 715 families responded confirming that using touchscreen is extremely common in toddlers. 

"The study showed that majority of toddlers had daily exposure to touchscreen devices, increasing from 51.22 per cent at six to 11 months to 92.05 per cent at 19-36 months," Smith added. 

In toddlers aged 19-36 months, the researchers found that the age that parents reported for their child's first actively scrolling a touchscreen was positively associated with the age that they were first able to stack blocks, a measure of fine motor control.

The study, published in the journal Frontiers in Psychology, also stated that the current generation of toddlers was adapting rapidly to new technology.

​New York, Sep 14 (IANS) Scientists have discovered a new mechanism in the mouse-brain that can help regulate obesity triggered by consuming a high-fat diet and can also be used as a potential treatment.

Consuming a high-fat diet results in changes in the brain that increases Rap1 gene, which is expressed in a variety of tissues, including the brain where it is involved in functions such as memory and learning.

Increase in Rap1 gene activity in turn leads to a decreased sensitivity to leptin -- the 'satiety hormone' produced by fatty tissue that helps regulate body weight by inhibiting appetite -- that sets the body on a path to obesity, the study said.

"This new mechanism involving Rap1 in the brain, may represent a potential therapeutic target for treating human obesity in the future," said Makoto Fukuda, Assistant Professor at Baylor College of Medicine in Texas, US.

In the study, the researchers analysed the mouse Rap1 gene and selectively deleted the gene in a group of neurons in the hypothalamus -- a region of the brain that is involved in regulating whole-body metabolism. 

While one group of mice were genetically engineered to lack the Rap1 gene, the other (control) group had a functional Rap1 gene. 

The scientists then fed both group of mice to a high-fat diet in which 60 per cent calories came from fat. 

As expected, the control mice with a working Rap1 gene gained weight, but, in comparison, the mice that lacked Rap1 had markedly reduced body weight and less body fat. 

Despite eating a high-fat diet, the mice lacking the Rap1 gene had not gained weight as a result of eating less as well as burning more body fat than mice with Rap1.

"These observations were associated with the hypothalamus producing more of a hormone that reduces appetite, called POMC, and less of hormones that stimulate appetite, called NPY and AgRP," Fukuda added. 

These mice also had lower levels of blood glucose and insulin than the controls.

Further, the mice that lacked Rap1 and ate a high-fat diet also did not develop leptin resistance, but were able to respond to leptin, and this was reflected in the hormone's lower blood levels, the researchers concluded in the paper appearing in the journal-- Cell Reports.

​London, Sep 14 (IANS) A healthy diet may develop better reading skills in the first three school years, shows a recent study from Finland.

The study involved 161 children aged 6-8 years old and the quality of their diet was analysed using food diaries and their academic skills with the help of standardised tests. 

The study, published in the European Journal of Nutrition, showed that children whose diet was rich in vegetables, fruits, berries, whole grain, fish and unsaturated fats, and low in sugary products, did better in tests measuring reading skills than their peers with a poorer diet quality.

The study also found that the positive associations of diet quality with reading skills in Grades 2 and 3 were not related to reading skills in Grade 1. These results indicate that children with healthier diets improved more in their reading skills from Grade 1 to Grades 2-3 than children with poorer diet quality.

"Another significant observation is that the associations of diet quality with reading skills were also independent of many confounding factors, such as socio-economic status, physical activity, body adiposity, and physical fitness," said Eero Haapala, Researcher at the University of Eastern Finland.

Diets like Baltic Sea Diet and Finnish nutrition recommendations -- high in vegetables, fruits and berries, fish, whole grain, and unsaturated fats and low in red meat, sugary products, and saturated fat -- are considered healthier.

A healthy diet seems to be an important factor in supporting learning and academic performance in children.

"Parents and schools have an important role in making healthy foods available to children. Furthermore, governments and companies play a key role in promoting the availability and production of healthy foods," Haapala added.

​Toronto, Sep 14 (IANS) Do you get angry or aggressive while driving? Beware, you may be at an increased risk of being in a motor vehicle collision than those who do not get angry while driving, a study has found.

"Even minor aggression, such as swearing, yelling or making rude gestures, can increase the risk of a collision," said lead author Christine Wickens, scientist at Centre for Addiction and Mental Health (CAMH) -- a psychiatric hospital in Ontario, Canada.

Drivers who made threats, attempted or succeeded in damaging another car or hurting someone, had the highest odds of collision -- 78 per cent higher than those whose aggression was considered minor.

The risk is comparable to those who use cannabis and drive, Wickens said adding that it was striking how the risk of collision rose as the levels of aggression increased.

People who reported no driving-related aggression had the lowest odds of collision, with increasing risk among those who had minor aggression, and the highest risk of all among those who reported both minor and more serious aggression.

The strong association suggests these drivers may have a greater chance of a collision because they either drive more aggressively or are distracted by their anger from other hazards on the road, the study said.

"Reducing driver anger and aggression would potentially reduce the risk of collisions," Wickens suggested. 

There are well established approaches to manage stress and anger, ranging from deep breathing techniques and listening to music to cognitive anger management programs. Leaving enough time on a car trip to reach your destination could also reduce stress, the researchers noted.

The findings were drawn from the CAMH Monitor, an ongoing survey of Ontario adults' mental health and risk behaviours, using responses from 12,830 people between 2002 and 2009. 

Just under eight per cent of Ontarians reported having a car collision in 2015. 

The group was analyzed in relation to their reported aggressive behaviour, while controlling for other factors that could increase the risk of collision such as age, sex, cannabis or alcohol use and other factors. 

The results were published in the journal Transportation Research Part F: Traffic Psychology and Behaviour.

Beijing, Sep 10 (IANS) China has completed the construction of the highest bridge in the world, 565 meters above the Nizhu River Canyon in the south, the local media reported on Saturday.

The bridge, called Beipanjiang and located between the Chinese provinces of Yunnan and Guizhou, is planned to be operational by the end of this year, Efe news reported. 

According to CCTV, the construction of Beipanjiang lasted for three years with the participation of at least 1,000 engineers and technicians.

With the opening of Beipanjiang, it will be officially the world's highest bridge overtaking China's Sidu River Bridge in the central province of Hubei, which opened in 2009.

The completion of Beipanjiang comes less than a month after the Asian country opened the world's longest and highest glass bridge on August 20, but this glass bridge (430 meters long and 300 meters high) was closed after two weeks due to huge turnout of visitors. 

London, Sep 12 (IANS) Children who spend a lot of time on social media platforms such as Facebook and Twitter are less happy with their appearance and they are more likely to quarrel with their parents, show results of a survey.

The survey involving 3,500 children between ages 10-15 found that of those who use social media for more than three hours a night, only 53 per cent were happy with their looks compared with 82 per cent who never use such sites.

The survey, carried out by Essex University in Britain over several years, also found that heavy users of social media are also more likely to argue with their parents, Daily Mail reported.

Some 44 per cent who are online for more than three hours said that they quarrelled with their mother more than once a week. Light and non-users of social networks are half as likely to argue with their mothers.

Truancy rates are also higher for heavy users (14 per cent) than light users (six per cent), the report added.

The survey, however, showed that aspiration to go to a university is marginally higher among social media users as compared to those who avoid social networks.

​New York, Sep 13 (IANS) NASA's Curiosity Mars rover has sent back spectacular colour images of layered rock formations on the Red Planet.

Curiosity, which is currently exploring the "Murray Buttes" region of lower Mount Sharp, took the images with its Mast Camera (Mastcam). The new images represent Curiosity's last stop in the Murray Buttes, where the rover has been driving for just over one month, NASA said.

"Curiosity's science team has been just thrilled to go on this road trip through a bit of the American desert southwest on Mars," said Curiosity Project Scientist Ashwin Vasavada of NASA's Jet Propulsion Laboratory at Pasadena, California.

The Martian buttes and mesas rising above the surface are eroded remnants of ancient sandstone that originated when winds deposited sand after lower Mount Sharp had formed.

"Studying these buttes up close has given us a better understanding of ancient sand dunes that formed and were buried, chemically changed by groundwater, exhumed and eroded to form the landscape that we see today," Vasavada said.

Curiosity landed near Mount Sharp in 2012. It reached the base of the mountain in 2014 after successfully finding evidence on the surrounding plains that ancient Martian lakes offered conditions that would have been favourable for microbes if Mars has ever hosted life. 

Rock layers forming the base of Mount Sharp accumulated as sediment within ancient lakes billions of years ago.

On Mount Sharp, Curiosity is investigating how and when the habitable ancient conditions known from the mission's earlier findings evolved into conditions drier and less favourable for life.

​Seoul, Sep 10 (IANS) A group of South Korean scientists has developed a new material to effectively block electromagnetic waves emanating from electronic gadgets and appliances, Yonhap news agency reported.

The team led by Gu Jong-min of the Korea Institute of Science and Technology (KIST) and a research team of Drexel University in the US successfully manufactured the material made out of Mxene.

Mxene is a class of two-dimensional inorganic compounds made out of titanium and carbon and a single layer is only about one nanometer.

The team discovered that Mxene can block the electromagnetic waves from mobile phones, televisions, microwave ovens and other appliances, scientists said, noting that the material is easy to process and the cost is relatively cheap.

"It is hoped that the developed material can be used not only to block electromagnetic waves but for other various purposes," Gu said.

The research was published in the journal Science.