Knowledge Update

​Beijing, Dec 3 (IANS) Older adults with cataracts -- clouding of the normally clear lens of the eye -- are more likely to have symptoms of depression, independent of lifestyle factors and visual acuity, a study has found.

The vision loss might cause older adults to become isolated and withdrawn and delve deeper into depression, which might make them less likely to seek treatment for cataracts, the study said.

The findings showed that symptoms of depression were more common in women than men.

Older adults with low levels of education were likely to have a 50 per cent increase in depressive symptoms than those who were highly educated.

There was no difference in depressive symptoms between the elderly with cataracts in one eye versus both eyes.

"Our study sheds further light on the complex relationship between ageing, vision loss, cataract, and depression and suggests that there may be a role for cataract surgery in improving mental health in the elderly," said Haifang Wang, from Soochow University in Suzhou, China.

Age-related cataracts are the leading cause of visual impairment worldwide and are expected to increase as population demographics shift towards advancing age. 

For the study, the team included nearly 4,600 older adults (60 years or older) from China. 

The participants also underwent a clinical eye examination to rate the presence and severity of cataracts.

"These results suggest that optometrists and vision care professionals should think beyond the direct effects of cataracts on visual impairment. We should also consider the broader impact that vision loss may have on mental health and well-being," the researchers said.

The study is published in the journal Optometry and Vision Science. 

​London, Dec 3 (IANS) Using radio telescopes in Australia and the US, an international team of scientists has discovered that the biggest galaxies in the universe develop in cosmic clouds of cold gas.

Until now scientists believed that these "supergalaxies" formed from smaller galaxies that grow closer and closer together until they merge, due to gravitational attraction.

"In the local universe, we see galaxies merging and we expected to observe that the formation of supergalaxies took place in the same way, in the early (now distant) universe," said first author Bjorn Emonts, researcher at Centro de Astrobiología (CSIC-INTA) in Madrid. 

To investigate this, telescopes were pointed towards an embryonic galaxy cluster 10 thousand million light years away, in whose interior the giant Spiderweb galaxy is forming, and the scientists discovered a cloud of very cold gas where the galaxies were merging.

This enormous cloud, with some 100 thousand million times the mass of the Sun, is mainly composed of molecular hydrogen, the basic material from which the stars and the galaxies are formed.

Previous studies had discovered the mysterious appearance of thousands of millions of young stars throughout the Spiderweb, and for this reason it is now thought that this supergalaxy condensed directly from the cold gas cloud.

Instead of observing the hydrogen directly, the researchers traced carbon monoxide, which is much easier to detect.

"It is surprising how cold this gas is, at some 200 degrees below zero Celsius," said the study's second author Matthew Lehnert, a researcher at the Astrophysics Institute of Paris.

For the study, the researchers combined the interferometers VLA (Very Large Array) in New Mexico (US) and the ATCA (Australia Telescope Compact Array) in Australia.

"Using sensitive observations of carbon monoxide, we show that the Spiderweb galaxy -- a massive galaxy in a distant protocluster -- is forming from a large reservoir of molecular gas," said the study published in the journal Science.

London, Dec 2 (IANS) Individuals with high levels of creative ambition and achievement are likely to be more resilient to death concerns, as creative achievements can act as buffer against anxiety over death, researchers have said. In a study, students with a record of creative achievement, coupled to high levels of creative goals, were found to make less death associations in their thought processes after thinking about their own demise in comparison to those with low levels of creativity. In comparison, among those with low levels of creative goals -- whatever be their record of creative achievement -- thinking about their own mortality were found to make more death associations in their thought processes. The findings suggested that those who pursue creativity and produce significant creative contributions may benefit from existential security -- the feeling that survival is secure -- in the face of death, said Rotem Perach, postgraduate researcher at the University of Kent, in Britain. In addition, creative people are often thought to be motivated by the desire to leave an enduring cultural legacy. Their creative achievement may be an avenue for symbolic immortality, or in other words, individuals who value creativity continue to live on in our culture even after passing away, the researchers noted. The researchers analysed a group of 108 students to understand the anxiety-buffering functions of creativity among people for whom creativity constitutes a central part of their cultural worldview, the paper published in the Journal of Creative Behavior.

​London, Dec 2 (IANS) Men accumulate more iron than women making them prone to Type 2 diabetes, researchers said. Two-fifth of men as compared to one-fifth of women were at risk. Iron is a micronutrient that is required in the formation of some essential body proteins and enzymes, like haemoglobin, cytochromes and peroxidase. However, it is harmful when stored in excess in the body. It promotes the release of free radicals that damage the secretion capacity of beta cells of pancreas to produce insulin. It also decreases insulin sensitivity in peripheral tissues and organs involved in glucose metabolism, the study said. The study, led by Alex O. Aregbesola from University of Eastern Finland, showed that men have 61 per cent higher prevalence and 46 per cent increased risk of developing Type 2 diabetes when compared with women. Excess body iron accumulation is a known risk factor of Type 2 diabetes in hereditary hemochromatosis -- a disorder that causes the body to absorb too much iron from the diet. However, the study showed that even mildly elevated body iron contributes to the prevalence and incidence of Type 2 diabetes. This excess iron was found to disturb the glucose metabolism in the body. On the other hand, moderate iron stores were found safer than depletion toward iron deficiency. Iron depletion toward deficiency did not offer protection against Type 2 diabetes. The type of association between iron stores and the risk of Type 2 diabetes showed that the risk was lowest on moderate levels, the researchers said. "This study provides a new body of evidence that mildly elevated body iron is an important risk factor of glucose metabolism derangement, which contributes to the increase in the prevalence and incidence of Type 2 diabetes," Aregbesola said, in the paper published in the journal Annals of Clinical Biochemistry.

​New York, Dec 2 (IANS) Hemanth Joseph, a Kerala-based security researcher, has identified a bug running in iOS 10.1 version of Apple's operating system that allowed him to bypass the activation lock on an iPad.

​Tokyo, Dec 2 (IANS) The Japan Aerospace Exploration Agency (JAXA) is building a low-cost space rocket with the help of Japanese tech manufacturer Canon, reports said on Friday.

​London, Dec 2 (IANS) Playing augmented reality games like Pokemon Go may help reduce phantom limb pain and improve the quality of lives in people affected by the condition, a study suggests.

Toronto, Dec 2 (IANS) Machine learning -- a powerful tool used for a variety of tasks in modern life, from fraud detection and sorting spam in Google, to making movie recommendations on Netflix -- can help scientists determine whether planetary systems are stable or not, a study says.

New York, Dec 2 (IANS) In a step aimed at preventing future outbreak of diseases such as dengue, Zika and chikungunya, researchers in Brazil have developed a test that analyses clinical samples from patients to diagnose infection by 416 viruses found in the world's tropical regions.

The tool can be used by reference laboratories to assist epidemiological surveillance by detecting pathogens with the potential to cause epidemics in humans.

"The number of patients with suspected dengue, Zika or chikungunya infection will increase when summer arrives," said lead author of the study Victor Hugo Aquino, Professor at University of Sao Paulo at Ribeirao Preto.

"Conventional methods are frequently unable to confirm diagnosis of these diseases, so we don't know which viruses are circulating," Aquino noted.

If a tool like this had been available when Zika began circulating in Brazil, it might have been possible to restrict its spread to the initial outbreak location, he said.

"We took a long time to realise an epidemic was under way because no one was thinking of Zika at the time," he said.

In addition to the pathogens, the platform detects others that as yet have been identified only sporadically but could become epidemics.

Examples include Mayaro, an alphavirus related to chikungunya that is transmitted by wild mosquitoes such as Haemagogus janthinomys, and Oropouche, which to date has caused epidemics confined to riverine communities in the Amazon region and is transmitted mainly by midges of the species Culicoides paraensis.

"There are several other viruses that haven't yet caused problems in humans but may do so one day," Aquino said. 

"They're evolving all the time, and with the degradation of natural environments infectious agents once confined to natural niches could spread farther afield," Aquino pointed out.

Although the platform is designed above all to detect pathogens transmitted by arthropods such as mosquitoes and ticks, it can also diagnose infectious agents transmitted by small mammals, like hantavirus, said the study published in the journal PLoS Neglected Tropical Diseases.

​New York, Dec 2 (IANS) Dramatic climate cycles on early Mars, triggered by buildup of greenhouse gases, may be the key to understanding how liquid water left its mark on the planet's surface, a study says.

Using climate models, the researchers showed warming periods -- caused when greenhouse gases reached a certain tipping point -- lasted millions of years on Mars, melting the glaciers that covered the surface of the planet, thereby creating liquid water.

Scientists have long debated how deep canyons and extensive valley networks -- like the kinds carved by running water over millions of years on Earth -- could form on Mars some 3.8 billion years ago, a time many believe the planet was frozen.

Previous studies suggested asteroid impacts might have warmed the planet, creating steam atmospheres that led to rain. But those warm periods would have much shorter durations and struggle to produce enough water, the researchers said.

"We think Mars had to be warm for millions to tens of millions of years, and the impact hypothesis can keep it warm for thousands of years," said study co-author Jim Kasting, Professor at Pennsylvania State University in the US. 

"In terms of water, we need millions of meters of rainfall, and they (previous studies) can get hundreds of meters," Kasting said.

The new study suggest a glacier-covered early Mars could have experienced long warm periods, lasting up to 10 million years at a time, caused by a thick atmosphere of carbon dioxide and hydrogen.

The team, which published its findings in the journal Earth and Planetary Science Letters, found the warming cycles would have lasted long enough, and produced enough water, to create the features.

"With the cycling hypothesis, you get these long periods of warmth that give you sufficient time to form all the different Martian valley networks," Natasha Batalha, graduate student at Pennsylvania State University, explained.