Knowledge Update

​New York, March 2 (IANS) Researchers have found a way to activate the immune system's natural cancer-killing T-cells and cause tumours to shrink in mice with colon cancer.

The intervention essentially trains the immune system to recognise and attack the tumour, and to protect against additional tumour formation - a significant issue in colon cancer, said corresponding author Ajay Maker, Associate Professor at University of Illinois College of Medicine in Chicago, US.

In the study, published in the journal Cancer Research, the researchers reported that increasing expression of a chemical cytokine called LIGHT in mice with colon cancer activated the immune system's natural cancer-killing T-cells and caused primary tumours in the liver to shrink.

LIGHT is an immune-stimulating chemical messenger previously found to have low levels of expression in patients with colon cancer metastases.

"For most patients with colon cancer that has spread to the liver, current treatments are palliative and not curative," Maker said.

"And while studies have suggested that immunotherapy may be a promising approach for advanced cancers, the use of such treatments for advanced gastrointestinal metastases have not yet been very successful," Maker said.

This study is exciting because it looks at an immunotherapy intervention for a previously unresponsive gastrointestinal cancer, Maker said.

For the study, the researchers established colon cancer tumors in a mouse model, in which the animals had an intact and unedited immune system. 

Once tumours were sizable, the mice were randomised into two groups - one group had the cytokine LIGHT turned on in the tumours, and the other served as a control group for comparison.

Tumours exposed to LIGHT showed an influx of T-cells that resulted in rapid and sustained diminishment in size, even after expression of the cytokine stopped. 

In cases where the tumour spread to liver, expression of LIGHT similarly provoked a potent immune response that resulted in a significant decrease in tumour burden.

"We demonstrated that delivery of a therapeutic immune-stimulating cytokine caused T-cells to traffic to tumours and to become activated tumor-killing cells," Maker said. 

Johannesburg, March 2 (IANS) African elephants -- the largest land animal -- sleep for just an average of two hours a day and regularly survive for nearly two days without sleep, a study has found.

Previous studies of sleep in captive elephants have shown that they sleep for four to six hours per day. 

However, "in their natural habitat, wild, free-ranging elephants sleep only for two hours per day, the least amount of sleep of any mammal studied to date, but this appears to be related to their large body size," said Paul Manger from the University of Witwatersrand in South Africa. 

For the study, published in the journal PLOS ONE, the team monitored two free-roaming African elephant matriarchs in Chobe National Park in Botswana for 35 days. The elephants were implanted with an actiwatch, in the trunk to track sleep accurately and a collar with a gyroscope to track sleeping position.

The researchers found that the elephants slept an average of two hours a day -- the shortest known sleep time of any land mammal. 

On several days, the elephants were found to survive without sleep for up to 46 hours. 

They travelled long distances of around 30 km during these periods, possibly due to disturbances such as lions or poachers and were found to sleep lying down only every few nights. 

"In addition, it appears that elephants only go into REM (rapid eye movement), or dreaming, sleep every three to four days, which makes elephant sleep unique," Manger added.

Beijing, March 2 (IANS) China will launch a space station core module in 2018 as the first step in completing the country's first space outpost, Xinhua news agency reported.

The core module of the space station, named "Tianhe-1" according to previous reports, will be launched on board a new-generation Long March-5 heavyweight carrier rocket, said Bao Weimin, director with CASC and a member of the National Committee of the Chinese People's Political Consultative Conference (CPPCC).

It will be followed by a series of launches for other components of the space station, including two space labs, which will dock with the core module while in space, in the next four years or so, he said, adding that the space station will be completed around 2022.

Assembly of the core module has already been completed and tests are currently under way, said Bao, who is in Beijing for the annual session of China's top political advisory body.

Earlier reports said the new Chinese space station will initially be much smaller than the current International Space Station (ISS), which weighs 420 tonnes, but could be expanded for future scientific research and international cooperation.

With the ISS set to retire in 2024, the Chinese space station will offer a promising alternative, and China will be the only country with a permanent space station.

Bao said the Chinese outpost will function in orbit for "dozens of years", and that it had been specially designed to be able to handle space debris.

"For the big pieces (of space debris), we could conduct evasive manoeuvres, and for those measuring less than 10 cm in size, we just take the hit," Bao said, adding that all key parts of the space station will be serviceable and replaceable.

He went on to say that the next five years will see some exciting advances in China's space programme.

​New York, March 1 (IANS) Days after it announced an exclusive "Made for India" Skype Lite app, Microsoft said it will soon discontinue its Skype Wi-Fi, a media report said.

The Skype Wi-Fi app would be delisted and it would no longer function after March 31.

​Singapore, March 1 (IANS) Using nearly 100,000 images extracted from Google Street View, a team of researchers has developed a method to map and quantify how street trees regulate ecosystem services.

London, March 1 (IANS) Frogs have the unique ability to see colour even when it is so dark that we are not able to see anything at all, new research has found.

The findings, published in the journal Philosophical Transactions of the Royal Society B, suggest that the night vision of frogs and toads may be superior to that of all other animals. 

"It's amazing that these animals can actually see colour in extreme darkness, down to the absolute threshold of the visual system. These results were unexpected," said one of the study authors Almut Kelber, Professor at Lund University in Sweden.

Most vertebrates, including humans, have two types of visual cells located in the retina, namely cones and rods. 

The cones enable us to see colour, but they usually require a lot of light and, therefore, stop working when it gets dark, in which case the rods take over so that we can at least find our way home, although in black and white.

In toads and frogs, the rods are a bit special. 

It was previously known that toads and frogs are unique in having rods with two different sensitivities. 

This has not been found in other vertebrates, and it is also the reason why researchers have long suspected that frogs and toads might be able to see colour also in low-light conditions.

The new study proves this to be true, and the results exceeded all expectations.

The researchers studied to what extent frogs and toads use their colour vision when searching for a mate or hunting for food. 

The results showed that the animals stop using their colour information fairly early when it comes to finding someone with whom to mate, whereas they continue to take advantage of their colour vision to select food in such low-light conditions that humans lose their ability to see colour.

"We have previously shown moths and geckos are also able to see colour in inferior light conditions compared to humans. However, frogs apparently have a unique ability to see colour in the dark," Kelber said.

New York, March 1 (IANS) Researchers have identified 35 mosquito species, including 26 previously unsuspected ones, that could possibly transmit the deadly Zika virus.

"The biggest take-home message is that these are the species that we need to prioritise," said lead author Michelle Evans from University of Georgia in the US. 

Zika virus is currently known to be transmitted to people primarily through the bite of an infected Aedes species mosquito (Ae. aegypti and Ae. albopictus). 

These are the same mosquitoes that spread dengue and chikungunya viruses, according to US Centers for Disease Control and Prevention.

The researchers said that targetting Zika's potential vectors -- species that can transmit the virus from one host to another -- is an urgent need, given its explosive spread and the devastating health effects associated with it.

The new predictive model, detailed in the journal eLife, could streamline the initial step of pinpointing Zika vectors.

"What we've done is to draw up a list of potential vector candidates based on the associations with viruses that they've had in the past as well as other traits that are specific to that species," study co-author Courtney Murdock, Assistant Professor at University of Georgia, said.

"That allows us to have a predictive framework to effectively get a list of candidate species without having to search blindly," Murdock said.

The researchers developed their model using machine learning, a form of artificial intelligence that is particularly useful for finding patterns in large, complicated data sets. 

Data used in the model consisted of information about the traits of flaviviruses -- the family that includes Zika, yellow fever and dengue -- and all the mosquito species that have ever been associated with them.

​Washington, March 1 (IANS) A trip past the sun may have selectively altered the production of one form of water in a comet known as Lovejoy -- an effect not seen by astronomers before, a new NASA study suggests.

The findings could shed new light on how much comets might have contributed to Earth's water compared to asteroids.

"Comets can be quite active and sometimes quite dynamic, especially when they are in the inner solar system, closer to the sun," said co-author of the study Michael Mumma, Director of NASA's Goddard Center for Astrobiology. 

NASA scientists observed the Oort cloud comet C/2014 Q2, also called Lovejoy, when it passed near Earth in early 2015. 

Through NASA's partnership in the W. M. Keck Observatory on Mauna Kea, Hawaii, the team observed the comet at infrared wavelengths a few days after Lovejoy passed its perihelion - or closest point to the sun.

The team focused on Lovejoy's water, simultaneously measuring the release of H2O along with production of a heavier form of water, HDO. 

Water molecules consist of two hydrogen atoms and one oxygen atom. A hydrogen atom has one proton, but when it also includes a neutron, that heavier hydrogen isotope is called deuterium, or the "D" in HDO. 

From these measurements, the researchers calculated the D-to-H ratio -- a chemical fingerprint that provides clues about exactly where comets (or asteroids) formed within the cloud of material that surrounded the young sun in the early days of the solar system.

Researchers also use the D-to-H value to try to understand how much of Earth's water may have come from comets versus asteroids.

The scientists compared their findings from the Keck observations with another team's observations made before the comet reached perihelion, using both space- and ground-based telescopes, and found an unexpected difference.

After perihelion, the output of HDO was two to three times higher, while the output of H2O remained essentially constant, showed the findings published online in the Astrophysical Journal Letters.

This meant that the D-to-H ratio was two to three times higher than the values reported earlier.

"If the D-to-H value changes with time, it would be misleading to assume that comets contributed only a small fraction of Earth's water compared to asteroids," lead author of the study Lucas Paganini, a researcher with the Goddard Center for Astrobiology, said.

​Kuala Lumpur, Feb 28 (IANS) The oil company Saudi Aramco will invest seven billion dollars in a refinery and petrochemical development project in Malaysia following a deal with Malaysia's Petronas, media reports said on Tuesday.

​Manila, Feb 28 (IANS) Developing economies of Asia and the Pacific region will need infrastructure investments worth $26 trillion from now until 2030, according to an Asian Development Bank (ADB) report issued on Tuesday.