Knowledge Update

Washington, July 26 (IANS) US space agency NASA will launch a spacecraft in September to a near-Earth asteroid known as Bennu to harvest a sample of surface material and return it to the Earth to scan for signs of life.

NASA's OSIRIS-REx spacecraft will measure the spectral signatures of Bennu's mineralogical and molecular components. Ideally, the sample will come from a region in which the building blocks of life may be found.

Known as OVIRS (OSIRIS-REx Visible and Infrared Spectrometer), the instrument on board will measure visible and near-infrared light reflected and emitted from the asteroid and split the light into its component wavelengths, much like a prism that splits sunlight into a rainbow.

"OVIRS is key to our search for organics on Bennu. In particular, we will rely on it to find the areas of Bennu rich in organic molecules to identify possible sample sites of high science value, as well as the asteroid's general composition," explained Lauretta, principal investigator for the OSIRIS-REx mission at University of Arizona in Tucson.

OVIRS will work in tandem with another OSIRIS-REx instrument -- the Thermal Emission Spectrometer (OTES).

While OVIRS maps the asteroid in the visible and near infrared, OTES picks up in the thermal infrared.

This will allow the science team to map the entire asteroid over a range of wavelengths that are most interesting to scientists searching for organics and water.

In the visible and infrared spectrum, minerals and other materials have unique signatures like fingerprints.

These fingerprints allow scientists to identify various organic materials, as well as carbonates, silicates and absorbed water, on the surface of the asteroid.

The data will actually allow scientists to make a map of the relative abundance of various materials across Bennu's surface.

"I can't think of a spectral payload that has been quite this comprehensive before," said Dennis Reuter, OVIRS instrument scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

As the spacecraft approaches Bennu, OVIRS will view one entire hemisphere at a time to measure how the spectrum changes as the asteroid rotates, allowing scientists to compare ground-based observations to those from the spacecraft.

Once at the asteroid, OVIRS will gather spectral data and create detailed maps of the surface and help in the selection of a sample site.

Despite its capabilities to perform complex science, OVIRS is surprisingly inexpensive and compact in its design.

The entire spectrometer operates at 10 watts, requiring less power than a standard household light bulb.

Unlike most spectrometers, OVIRS has no moving parts, reducing the risk of a malfunction.

"We designed OVIRS to be robust and capable of lasting a long time in space," Reuter said in a NASA statement.

The team also had to plan for another major threat: water.

Immediately after launch, the team will turn on heaters on the instrument to bake off any water.

The heat will not be intense enough to cause any damage to OVIRS, and the team will turn the heaters off once all of the water has evaporated​

​Washington, July 26 (IANS) When it comes to facing a job interview, better go in-person instead of a video-based or other technology-mediated interviews, if you have the options, new research suggests.

"We live in a world where we increasingly rely on technology, but this study reminds us that personal interactions should never be underestimated," said study author Nikki Blacksmith, a doctoral candidate at George Washington University.

The study found that in-person interviews yielded better impressions for both the company and the candidate. 

"Many times, the candidate does not have a choice in the format of the interview. However, the organization does have a choice and if they are not consistent with the type of interview they use across candidates, it could result in fairness issues and even possibly a lawsuit," Blacksmith noted.

To compare the effectiveness of in-person and technology-mediated interviews, Ms. Blacksmith and her co-authors examined 12 articles published from 2000-2007 that included interviewer and interviewee ratings, that is, assessment of how the company and the candidate performed during the interview. 

The study found that, overall, technology-mediated interviews resulted in lower ratings for both the company and the candidate. 

Within that category, video interviews received the most negative rankings, followed by telephone and computer interviews. 

Face-to-face interviews received more favourable rankings.

Additionally, the study looked at the effect of time on the ratings, assuming that as people became more accustomed to the technology and it improved or advanced, they would rate it higher. 

In fact, the opposite occurred, and ratings became more negative for more recent studies, showed the findings published in the journal Personnel Assessment and Decisions.​

London, July 26 (IANS) Using a novel technique, scientists have demonstrated for the first time that it is possible to selectively sequence fragments of DNA in real time, thus greatly reducing the period needed to analyse biological samples.

"This is the first time that direct selection of specific DNA molecules has been shown on any device. We hope that it will enable many future novel applications, especially for portable sequencing," said Matt Loose from University of Nottingham.

Called MinION, the new device was used with real-time nanopore sequencing to enable the user analyse only DNA strands that contain pre-determined signatures of interest. 

"This makes sequencing as efficient as possible and will provide a viable, informatics based alternative to traditional wet lab enrichment techniques. The application of this approach to a wide number of problems from pathogen detection to sequencing targeted regions of the human genome is now within reach," Loose added in a paper described in the journal Nature Methods.

The pocket-sized device -- the same technology which NASA recently sent to the International Space Station (ISS) in an effort to investigate whether DNA sequencing is possible in microgravity - employs tiny molecular pores in a membrane that 'sense' the sequence of DNA fragments passing through these nanopores, producing minute fluctuations in a current trace. 

These current traces, termed "squiggles" then need to be converted to DNA bases using base caller software, often located in the cloud. The team used signal processing techniques to map these squiggles to reference sequences, by passing this step.

The researchers showed that this "real-time selective sequencing", or as some have called it "DNA testing", can reduce the time needed to sequence key DNA fragments or enable the analysis of pathogen samples where there is host and other DNA present in the sample.​

​Beijing, July 25 (IANS) The Chinese city of Sansha has decided to allocate five million yuan (about $748,000) annually for maritime environmental conservation for the next three years.

New York, July 23 (IANS) A US-based startup has launched a smart laptop shell that turns your Android smartphone into a complete laptop -- making it more convenient and affordable for people in developing countries like India and South Africa to carry their office in their pocket, literally.

​Nairobi, July 23 (IANS) African countries affected by the massive drop in the global prices of oil should direct trade policies to new sectors, a UN official said.

Mukhisa Kituyi, Secretary-General of the UN Conference on Trade and Development (UNCTAD), made the appeal at the close of a major ministerial conference in Nairobi on

New York, July 22 (IANS) Borrowing an idea from metalsmiths and pastry chefs, researchers have created composite materials containing hundreds of layers that are just atoms thick but span the full width of the material -- a feat that could open new vistas in materials science.

The work, described recently in the journal Science, could open up wide-ranging possibilities for designing new, easy-to-manufacture composites for optical devices, electronic systems, and high-tech materials. 

Materials such as graphene, a two-dimensional form of pure carbon, and carbon nanotubes, tiny cylinders that are essentially rolled-up graphene, are "some of the strongest, hardest materials we have available," said Michael Strano from the Massachusetts Institute of Technology (MIT) .

Therefore, researchers have been searching for ways of using these nanomaterials to add great strength to composite materials, much the way steel bars are used to reinforce concrete.

However, the biggest obstacle has been finding ways to embed these materials within a matrix of another material in an orderly way. 

These tiny sheets and tubes have a strong tendency to clump together, so just stirring them into a batch of liquid resin before it sets doesn't work at all. The MIT team's insight was in finding a way to create large numbers of layers, stacked in a perfectly orderly way, without having to stack each layer individually.

They used a technique similar to that used to make ultrastrong steel sword blades, as well as puff pastries. 

A layer of material -- be it steel, dough, or graphene -- is spread out flat. Then, the material is doubled over on itself, pounded or rolled out, and then doubled over and over again.

With each fold, the number of layers doubles, thus producing an exponential increase in the layering. Just 20 simple folds would produce more than a million perfectly aligned layers.

The MIT team produced composites with up to 320 layers of graphene embedded in them. They were able to demonstrate that even though the total amount of the graphene added to the material was minuscule -- less than 1/10 of a percent by weight -- it led to a clear-cut improvement in overall strength.

The team also found a way to make structured fibres from graphene, potentially enabling the creation of yarns and fabrics with embedded electronic functions, as well as yet another class of composites.​

London, July 25 (IANS) Diabetes may be due to the failure of a privileged few cells, rather than the behaviour of all cells, suggests new research.

"This study is interesting as it suggests that failure of a handful of cells may lead to diabetes," said co-lead researcher Guy Rutter from Imperial College London.

Type-2 diabetes occurs when the pancreas fails to produce enough insulin to function properly, meaning that glucose stays in the blood rather than being converted into energy.

Beta cells make up around 65-80 per cent of the cells in the islets of the pancreas. Their primary function is to store and release insulin and, when functioning correctly, can respond quickly to fluctuations in blood glucose concentrations by secreting some of their stored insulin.

The new findings showed that just one to ten per cent of beta cells control islet responses to glucose.

"These specialised beta cells appear to serve as pacemakers for insulin secretion. We found that when their activity was silenced, islets were no longer able to properly respond to glucose," David Hodson from the University of Birmingham explained.

Studies were conducted on islet samples from both murine and human models. 

The researchers used optogenetic and photopharmacological targeting to precisely map the role of the cells required for the secretion of insulin.

The team believes that the findings, published in the journal Cell Metabolism, could pave the way for therapies that target these handful of specialised cells.

"It has long been suspected that ‘not all cells are equal’ when it comes to insulin secretion. These findings provide a revised blueprint for how our pancreatic islets function, whereby these hubs dictate the behaviour of other cells in response to glucose," Hodson noted.​

​New York, July 23 (IANS) A new imaging software can not only predict how you will look with different hair styles, colours and appearances but can also help find a missing child or someove evading the law.

​Beijing, July 22 (IANS) Chinese Prime Minister Li Keqiang on Friday said Beijing will continue pushing market-based reforms regardless of whether the European Union (EU) grants it the status of a market economy.