Knowledge Update

London, April 29 (IANS) When medication is used to shut off the oxygen supply to tumours, the cells adapt their metabolism in the medium term -- by switching over to producing energy without oxygen, new research has found.

Medicines can initially slow or even stop tumour growth. However, as the treatment goes on, the tumours begin to develop resistance to these therapies -- and they start to grow again.

The new findings, reported in the journal Cell Reports, could be used for treatments that can inhibit tumour growth in the long term.

Today, it is common knowledge that the disease develops in a series of stages. One of these stages, tumor angiogenesis, involves the formation of new blood vessels to supply oxygen and nutrients to the growing tumour.

Now, the research team has shown that, although the latest medications are effective at preventing blood vessel formation, the tumours can continue growing even without a supply of new blood vessels.

Analysis of this finding from a biochemical and molecular genetic perspective revealed that the tumour cells convert to a different type of metabolism. They no longer produce energy using oxygen delivered via the blood vessels -- but instead switch over to glycolysis, a form of anaerobic energy production. 

The lactic acid formed as a result is delivered to cells that are still receiving sufficient oxygen and that can use the lactic acid, together with the oxygen, to produce energy.

The research group also showed that this specific mode of metabolism -- and therefore the tumour's growth -- can be interrupted, namely by inhibiting anaerobic energy production or transport of the lactic acid. 

"Our findings open up new approaches for the optimisation of anti-angiogenic therapies and for inhibiting tumor growth effectively in the long term," said lead researcher Gerhard Christofori, professor at University of Basel in Switzerland.​

New York, April 29 (IANS) Retweeting or sharing information on the micro-blogging site can actually make things worse for you as it creates a “cognitive overload” that interferes with learning and retaining what you've just seen, researchers report.

According to the team from Cornell University in the US, that “overload” can spill over and diminish performance in the real world."Most people don't post original ideas any more. You just share what you read with your friends," said Qi Wang, professor of human development at Cornell.“But they don't realise that sharing has a downside. It may interfere with other things we do,” he warned.

Wang and colleagues in China conducted experiments showing that "retweeting" interfered with learning and memory, both online and off.The experiments were conducted at Beijing University, with a group of Chinese college students as subjects.At computers in a laboratory setting, two groups were presented with a series of messages from Weibo - the Chinese equivalent of Twitter.

After reading each message, members of one group had options either to repost or go on to the next message. The other group was given only the "next" option.After finishing a series of messages, the students were given an online test on the content of those messages.Those in the repost group offered almost twice as many wrong answers and often demonstrated poor comprehension.What they did remember they often remembered poorly, Wang reported. "For things that they reposted, they remembered especially worse," she added.

The researchers found that reposters were suffering from "cognitive overload."“When there is a choice to share or not share, the decision itself consumes cognitive resources,” Wang explained.After viewing a series of Weibo messages, the students were given an unrelated paper test on their comprehension of a “New Scientist” article.

Again, participants in the no-feedback group outperformed the reposters. The results confirmed a higher cognitive drain for the repost group."The sharing leads to cognitive overload, and that interferes with the subsequent task," Wang said.“In real life when students are surfing online and exchanging information and right after that they go to take a test, they may perform worse," she suggested in a paper described in the journal Computers in Human Behavior.The researchers suggest that web interfaces should be designed to promote rather than interfere with cognitive processing."Online design should be simple and task-relevant," Wang noted.​

​London, April 29 (IANS) The very oldest pieces of rock on Earth -- zircon crystals -- are likely to have formed in the craters left by violent asteroid impacts that peppered our nascent planet rather than via plate tectonics as previously believed, researchers report.

The tiny crystals probably formed in huge impact craters not long after Earth formed, some four billion years ago.

Rocks that formed over the course of Earth's history allow geologists to infer things such as when water first appeared on the planet, how our climate has varied, and even where life came from.

Ten years ago, a team of researchers in the US argued that the ancient zircon crystals probably formed when tectonic plates moving around on the Earth's surface collided with each other in a similar fashion to the disruption taking place in the Andes Mountains today.

However, current evidence suggests that plate tectonics -- as we know it today -- was not occurring on the early Earth.

So, the question remained: Where did the crystals come from?

Recently, geologists suggested these grains may have formed in huge impact craters produced as chunks of rock from space, up to several km in diameter, slammed into a young Earth.

To test this idea, researchers from Trinity College Dublin decided to study a much younger impact crater to see if zircon crystals similar to the very old ones could possibly have formed in these violent settings.

With the support of the Irish Reseach Council (IRC) and Science Foundation Ireland (SFI), the team collected thousands of zircons from the Sudbury impact crater in Ontario, Canada.

After analysing these crystals at the Swedish Museum of Natural History in Stockholm, they discovered that the crystal compositions were indistinguishable from the ancient set.

“What we found was quite surprising. Many people thought the very ancient zircon crystals couldn't have formed in impact craters, but we now know they could have,” said Gavin Kenny from Trinity's school of natural sciences in a paper published in the journal Geology.

“There's a lot we still don't fully understand about these little guys but it looks like we may now be able to form a more coherent story of Earth's early years,” he added.

Kenny recently presented the findings at the annual Lunar and Planetary Science Conference (LPSC) in Houston, Texas.​

​London, April 29 (IANS) Serious gamers generally avoid touchscreens because these devices lack physical buttons due to which the key press timing in touchscreen input is unpredictable, a team of Finnish researchers has found.

When timing is made more predictable, performance improves, said the group from Aalto University.

"The common view was that the lack of physical buttons is critical but you also have tactile feedback from the surface of a touchscreen. Another false belief was that touchscreens are slower but that is not the case anymore," said Byungjoo Lee, one of the researchers. 

The team conducted experiments where participants were asked to tap a display when a target would appear. 

The data showed large differences between physical keys and touchscreens in how reliably users could time their presses.

The researchers proposed a new theory explaining that there are three sources of error that make timing very hard with touchscreens.

First, people are not able to keep the finger at a constant distance above the surface. The finger is always moving, and even the slightest movement hampers our ability to time precisely. 

By contrast, when using physical keys, the finger rests on the key, eliminating this source of error.

"Second, when the finger touches the surface, it is hard for the neural system to predict when the input event has been registered. Typically software detects the touch when the finger first touches the display. But users cannot sense this event so it is not predictable for them," the authors explained.

Third, when the event has been registered on the touchscreen, it still needs to be processed in the application and in some cases the time that it takes is longer than in other ones, creating another source of latency.

The new theory implies that users' performance can be improved by making touch events more predictable. 

The paper is scheduled to be presented at the "Conference on Human Factors in Computing Systems 2016" (CHI16 conference) in San Jose, California, in May.​

Washington, April 29 (IANS) Using data from NASA’s Chandra X-ray Observatory and other optical telescopes, astronomers have developed a powerful new method for investigating dark energy - the mysterious energy that is currently driving the accelerating expansion of the universe.

The technique takes advantage of the observation that the outer reaches of galaxy clusters, the largest structures in the universe held together by gravity, show similarity in their X-ray emission profiles and sizes.

More massive clusters are simply scaled up versions of less massive ones.

“In this sense, galaxy clusters are like 'Russian dolls', with smaller ones having a similar shape to the larger ones,” said Andrea Morandi from University of Alabama in Huntsville.

“Knowing this lets us compare them and accurately determine their distances across billions of light years,” he added.

By using these galaxy clusters as distance markers, astronomers can measure how quickly the universe was expanding at different times since the Big Bang.

According to Einstein’s theory of general relativity, the rate of expansion is determined by the properties of dark energy plus the amount of matter in the Universe, where the latter is mostly made up of unseen material called dark matter.

The latest results confirm earlier studies that the properties of dark energy have not changed over billions of years.

They also support the idea that dark energy is best explained by the “cosmological constant,” which Einstein first proposed and is equivalent to the energy of empty space.

“Although we’ve looked hard at other explanations, it still appears that dark energy behaves just like Einstein's cosmological constant,” added study co-author Ming Sun.

To reach this conclusion, the researchers studied 320 galaxy clusters with distances from Earth that ranged from about 760 million light years to about 8.7 billion light years.

“We think this new technique has the ability to provide a big leap forward in our understanding of dark energy,” the authors noted in a paper appeared in the Monthly Notices of the Royal Astronomical Society journal.​

​Washington, April 28 (IANS) The US economy grew at an annual rate of 0.5 percent in the first quarter of this year, pulled back by slowing consumption, the commerce department said on Thursday.

​New York, April 28 (IANS) Not just connecting you with friends, interaction with fellow students on social networking website can help you focus and study better, say researchers.

​Hong Kong, April 29 (IANS) Italian luxury fashion house Gucci has sent warning letters to Hong Kong shops not to sell paper versions of its branded products as offerings to the dead, a report said on Friday. Paper replicas of items like mansions, cars, iPads and luxury bags are burnt in the belief when people die so they can use them in the afterlife, BBC reported. "We fully respect the funeral context and we trust that the store owners did not have the intention to infringe Gucci's trademark," Gucci Hong Kong said in a statement. "Thus a letter was sent on an informational basis to let these stores know about the products they were carrying and by asking them to stop selling those items," the statement said. In Hong Kong, some shops that had reportedly received the letters have removed their Gucci wares. But other brands, including Louis Vuitton, Saint Laurent, Burberry and New Balance, are still on sale. Demand for these products is highest during the Qingming "tomb-sweeping" festival which took place last month.​

​New York, April 29 (IANS) Tiny doses of a cancer drug may stop the raging, uncontrollable immune response to infection that leads to sepsis, say researchers.

A small dose of topoisomerase I (Top 1) inhibitor can dampen an acute inflammatory reaction to infection while still allowing the body's protective defense to take place, showed the findings published in the journal Science.

The treatment may help control not only sepsis but also new and brutal assaults on human immunity such as novel influenza strains and pandemics of Ebola and other singular infections, said the study's senior investigator, Ivan Marazzi, assistant professor at Icahn School of medicine at Mount Sinai in New York.

Sepsis -- deadly infections often acquired in hospital by patients with a weak immune system -- is caused by an excessive host response to infection, which in turn leads to multiple organ failure and death. 

The team found that use of one to three doses of a Top 1 inhibitor that is one fiftieth the strength of normal chemotherapy was enough to rescue 70-90 percent of mice from an inflammatory storm death due to either acute bacterial infection, liver failure, or virus-bacteria co-infection. 

The treatment did not produce overt side effects.

They also tested the inhibitor in cells infected with influenza, Ebola, and other viral and bacterial microbes that over-stimulate the immune system, and found the drug blunted a dangerous immune reaction.

"Our results suggest that a therapy based on Top 1 inhibition could save millions of people affected by sepsis, pandemics, and many congenital deficiencies associated with acute inflammatory episodes -- what is known as a cytokine, or inflammatory, storm," Marazzi said.

"These storms occur because the body does not know how to adjust the appropriate level of inflammation that is good enough to suppress an infection but doesn't harm the body itself," he said. 

"This drug appears to offer that life-saving correction," Marazzi explained​

Beijing, April 29 (IANS) China's migrant workforce reached 277.5 million in 2015, an annual rise of 1.3 percent, but the year-on-year growth rate has been decreasing since 2011, according to the National Bureau of Statistics.