Knowledge Update

​Toronto, June 1 (IANS) What is the mass of our Milky Way? It is 7X1011 solar masses or, in simpler terms, the mass of our Sun multiplied by 700 billion, say researchers who have tried to measure this galactic challenge with a new method.

The Sun, for the record, has a mass of two nonillion (that's two followed by 30 zeroes) kg or 330,000 times the mass of the Earth.

“And our galaxy isn't even the biggest galaxy," said Gwendolyn Eadie, PhD candidate in physics and astronomy at Hamilton-based McMaster University.

Measuring the mass of our home galaxy, or any galaxy, is particularly difficult. 

A galaxy includes not only stars, planets, moons, gases, dust and other objects and material, but also a big helping of dark matter, a mysterious and invisible form of matter that is not yet fully understood. 

Astronomers, however, can infer the presence of dark matter through its gravitational influence on visible objects.

Eadie has been studying the mass of the Milky Way and its dark matter component by using the velocities and positions of globular star clusters that orbit the Milky Way.

The orbits of globular clusters are determined by the galaxy's gravity, which is dictated by its massive dark matter component. 

What's new about Eadie's research is the technique she devised for using globular cluster (GCs) velocities.

The total velocity of a GC must be measured in two directions: one along our line-of-sight, and one across the plane of the sky (the proper motion). 

Eadie has developed a way to use these velocities that are only partially known, in addition to the velocities that are fully known, to estimate the mass of the galaxy. 

Her method also predicts the mass contained within any distance from the centre of the galaxy, with uncertainties, which makes her results easy to compare with other studies.

Eadie and her academic supervisor William Harris, professor of physics and astronomy at McMaster, have submitted their work for publication in the Astrophysical Journal.​

​Sydney, June 1 (IANS) Contrary to previous beliefs, the population size of a bee specie has increased dramatically during the global warming following the last Ice Age, finds a study.

The Australian small carpenter bee -- found in sub-tropical, coastal and desert areas in Australia -- has flourished in the period of global warming following the last Ice Age some 18,000 years ago.

"You see a rapid increase in population size from about 18,000 years ago just as the climate began warming up after the last Ice Age," says lead author Rebecca Dew from the Flinders University of South Australia. 

Previous studies have showed that bees -- major pollinators and critical for many plants, ecosystems, and agricultural crops -- from diverse habitats respond strongly to climate change.

"Different climate, different environment but the bees have responded in the same way at around the same time," Dew said in the paper published in the Journal of Hymenoptera Research.

For the study, the team modelled its past responses to climate change with the help of DNA sequences. 

"It is really interesting that you see very similar patterns in bees around the world," Dew noted. 

However, some studies showed that some rare and ancient tropical bees require cool climate and, as a result, are already restricted to the highest mountain peaks. For these species, climate warming could spell their eventual extinction.​

​London, June 1 (IANS) An international team of astrophysicists has stumbled upon an unusual astronomical object -- an Einstein ring which is a distorted image of a very distant galaxy termed as “the source”.

Doctoral student Margherita Bettinelli from the Instituto de Astrofísica de Canarias (IAC) and the University of La Laguna (ULL) along with the team discovered this rare phenomenon while analysing images of the Sculptor dwarf galaxy. 

The phenomena, predicted by Albert Einstein's theory of General Relativity, is quite rare but scientifically interesting. The interest is sufficiently strong that this object has been given its own name: "The Canarias Einstein ring". 

The chance discovery was made when Bettinelli was examining data taken through the “Dark Energy Camera” (DECam) of the 4m Blanco Telescope at the Cerro Tololo Observatory in Chile. 

She noticed the peculiar morphology of the Einstein ring. 

The “Canarias Einstein ring” is one of the most symmetrical discovered until now and is almost circular, showing that the two galaxies are almost perfectly aligned. 

The source galaxy is 10,000 million light years away from us. 

Due to the expansion of the Universe, this distance was smaller when its light started on its journey to us, and has taken 8,500 million years to reach us. 

“We observe it as it was then: a blue galaxy which is beginning to evolve, populated by young stars which are forming at a high rate. The lens galaxy is nearer to us, 6,000 million light years away, and is more evolved. Its stars have almost stopped forming, and its population is old,” the authors noted.

"Studying these phenomena gives us especially relevant information about the composition of the source galaxy, and also about the structure of the gravitational field and of the dark matter in the lens galaxy,” explained Antonio Aparicio, one of the astrophysicts who is leading the research. 

The results were published in the international journal Monthly Notices of the Royal Astronomical Society.​

​London, June 1 (IANS) The high-tech 3D mapping of our newly-found relative Homo naledi's home has opened the doors for scientists to use the space-age technology to search for pre-historic bones.

The extremely difficult conditions in which Professor Lee Berger's team from University of the Witwatersrand's (Wits) was forced to work gave rise to the use of space-age technology to map the Dinaledi chamber and Rising Star Cave in which over 1500 Homo naledi fossils were found.

Ashley Kruger, PhD candidate in palaeoanthropology, roped in the use of high-tech laser scanning, photogrammetry and 3D mapping technology to bring high-resolution digital images on an almost real-time basis in order to make vital decisions regarding the underground excavations.

“This is the first time ever where multiple digital data imaging collection has been used on such a sale, during a hominin excavation," Kruger said.

In 2013, after the discovery of the hominin assemblage, Berger planned an expedition to excavate what became known as the Dinaledi Chamber, a cave system near the Sterkfontein Caves, about 40 km north-west of Johannesburg in South Africa. 

An all-female team of six were selected to undertake the underground excavation due to the challenge of navigating a 12 meter vertical Chute, and passing through an 18 cm gap.

Berger himself was unable to go down into the chamber, which forced the team to introduce high-tech digital imaging techniques to virtually bring the exploration site to the surface.

Kruger and colleagues have now mapped the entire path of the Rising Star Cave, including the Dinaledi Chamber, both on the surface and underground.

“The 3D scans of the cave and excavation area helped scientists above ground immensely in making decisions about the next step to take with regards to excavations,” added Dr Marina Elliot, Rising Star excavation manager.

“These methods provided researchers with a digital representation of the site from landscape level right down to individual bones,” noted Kruger in a paper published in the scientific journal, the South African Journal of Science.

The precise digital reconstruction of the Rising Star Cave provides new insights into the Dinaledi Chamber's structure and location, as well as the exact location of the fossil site, the authors stated. ​

Toronto, June 1 (IANS) Cooling down the roofs by using reflective surfaces can not only help you beat the heat but also lower air-conditioning bills, suggests new research.

"Our study proves that cool roofs for commercial buildings are a net saver of energy in all climates that use air conditioning during the summer," said Hashem Akbari, Professor at Concordia University in Montreal, Canada and the study's senior author.

"In cooler climates, installing cool roofs may even prevent buying an air conditioner altogether. Even in non-air-conditioned buildings, cool roofs improve comfort during hot summer days. And in extreme cases, these roofs may even save lives by reducing the risk of heat stroke," Akbari noted.

The findings appeared in the journal Energy and Buildings.

"Our research shows that any improvement to a roof that limits the summertime solar heat gain actually results in energy-cost savings for the building owner, as well as a reduction in the building's overall environmental impact," Akbari said.

For the study, the researchers used modelling software to simulate energy consumption for several prototype office and retail buildings in four cold-climate cities in North America - Anchorage, Milwaukee, Montreal and Toronto.

They found that cool roofs for the simulated buildings resulted in annual energy expenditure savings in all municipalities.

The research also showed that cool roofs can reduce the peak electric demand of the buildings by up to five watts per square metre.

"On a large scale, cool roofs can moderate the air temperature surrounding a building, decrease greenhouse gas emissions and mitigate the urban heat island effect," Akbari said

"Put simply, cool roofs cool the globe," he noted.​

New York, June 1 (IANS) A protein designed by researchers at Georgia State University has been found effective in killing cells linked to the development and progression of a number of diseases, including cancer.

The protein ProAgio, which is created from a human protein, target a cell surface receptor -- biological channel of information transfer -- linked to a number of diseases.

The protein targets the cell surface receptor integrin v3 at a novel site that has not been targeted by other scientists. 

The researchers found that the novel protein induces apoptosis, or programmed cell death, of cells that express integrin v3. 

This integrin has been a focus for drug development because abnormal expression of v3 is linked to the development and progression of a number of diseases.

The findings were reported in the journal Nature Communications.

"This integrin pair, v3, is not expressed in high levels in normal tissue," said Zhi-Ren Liu, lead author of the study and Professor at Georgia State. 

"In most cases, it's associated with a number of different pathological conditions. Therefore, it constitutes a very good target for multiple disease treatment," Liu noted.

In this study, researchers performed extensive cell and molecular testing that confirmed the protein interacts and binds well with integrin v3. 

They found that the protein was much more effective in inducing cell death than other agents tested.

In addition, tests with mouse models of cancer showed ProAgio strongly inhibits tumour growth. 

Tissue analyses indicated the protein effectively prevents the growth of tumour blood vessels, while existing blood vessels were not affected. Toxicity tests also showed that the protein is not toxic to normal tissue and organs in mice​

New York, June 1 (IANS) Chronic stress can make us worn-out, anxious and depressed as well as also lead to structural changes in the brain, finds a new study that also developed a new drug that might help in preventing these changes.

The findings showed that when mice experienced prolonged stress, the amygdala -- a part of the brain that regulates basic emotions, such as fear and anxiety -- retracts. 

In the medial amygdala, the neuronal branches, which form crucial connections to other parts of the brain, appeared to shrink. 

Such shrinking can harm the brain, distorting its ability to adapt to new experiences, leaving it trapped in a state of anxiety or depression, the researchers said.

"When we took a closer look at three regions within amygdala, we found that neurons within one, the medial amygdala, retract as a result of chronic stress,” said lead author Carla Nasca, post doctoral researcher at Rockefeller University in the US.

"While this rewiring can contribute to disorders such as anxiety and depression, our experiments with mice showed that the neurological and behavioural effects of stress can be prevented with treatment by a promising potential antidepressant that acts rapidly," Nasca added.

In the research, published in the journal Molecular Psychiatry, the team found that the protective approach increased resilience among mice most at risk for developing anxiety or depression-like behaviours.

The team first subjected mice to 21 days of periodic confinement within a small space -- an unpleasant experience for mice. 

Afterward, they tested the mice to see if their behaviours had changed, for instance, if they had begun to avoid social interaction and showed other signs of depression. They also analysed the neurons of these mice within the the regions of the amygdala.

The scientists repeated the stress experiment and this time they treated the mice with acetyl carnitine -- a molecule known for its potential to act as a rapid-acting antidepressant.

The results showed that the mice fared better than their untreated counterparts. Not only were they more sociable, the neurons of their medial amygdalas also revealed more branching.​

​New York, May 30 (IANS) Social networking platforms like Facebook can not only get you more likes, it can also influence the price of your home if you intend to sell one, say researchers.​

​New York, May 29 (IANS) The success of a global renewable energy project on Ecuador's Galapagos archipelago has given a major boost to the idea of sustainable development, according to a report.

​London, May 29 (IANS) The economic crisis of 2008-10 and the rise in unemployment that accompanied it led to dramatic rise in cancer-related deaths, says a study.

The recent global economic crisis was linked with more than 260,000 excess cancer deaths among the 35 member states of the Organisation for Economic Development (OECD)