Spectacular 'honeycomb heart' revealed in iconic stellar explosion

A unique 'heart-shape', with wisps of gas filaments showing an intricate honeycomb-like arrangement, has been discovered at the centre of the iconic supernova remnant, the Crab Nebula. Astronomers have mapped the void in unprecedented detail, creating a realistic three-dimensional reconstruction. The new work is published in Monthly Notices of the Royal Astronomical Society.

The Crab, formally known as Messier 1, exploded as a dramatic supernova in 1054 CE, and was observed over the subsequent months and years by ancient astronomers across the world. The resulting nebula -- the remnant of this enormous explosion -- has been studied by amateur and professional astronomers for centuries. However, despite this rich history of investigation, many questions remain about what type of star was originally there and how the original explosion took place.

Thomas Martin, the researcher at Université Laval who led the study, hopes to answer these questions using a new 3D reconstruction of the nebula. "Astronomers will now be able to move around and inside the Crab Nebula and study its filaments one by one," said Martin.

The team used the powerful SITELLE imaging spectrometer on the Canada-Hawaii-France Telescope (CFHT) in Mauna Kea, Hawaii, to compare the 3D shape of the Crab to two other supernova remnants. Remarkably, they found that all three remnants had ejecta arranged in large-scale rings, suggesting a history of turbulent mixing and radioactive plumes expanding from a collapsed iron core.

Co-author Dan Milisavljevic, an assistant professor at Purdue University and supernova expert, concludes that the fascinating morphology of the Crab seems to go against the most popular explanation of the original explosion.

"The Crab is often understood as being the result of an electron-capture supernova triggered by the collapse of an oxygen-neon-magnesium core, but the observed honeycomb structure may not be consistent with this scenario," Milisavljevic said.

The new reconstruction was made possible by the ground-breaking technology used by SITELLE, which incorporates a Michelson interferometer design allowing scientists to obtain over 300,000 high-resolution spectra of every single point of the nebula.

"SITELLE was designed with objects like the Crab Nebula in mind; but its wide field of view and adaptability make it ideal to study nearby galaxies and even clusters of galaxies at large distances," said co-author Laurent Drissen.

Read more at Science Daily

Astronomers uncover mysterious origins of 'super-Earths'

Mini-Neptunes and super-Earths up to four times the size of our own are the most common exoplanets orbiting stars beyond our solar system. Until now, super-Earths were thought to be the rocky cores of mini-Neptunes whose gassy atmospheres were blown away. In a new study published in The Astrophysical Journal, astronomers from McGill University show that some of these exoplanets never had gaseous atmospheres to begin with, shedding new light on their mysterious origins.

From observations, we know about 30 to 50 percent of host stars have one or the other, and the two populations appear in about equal proportion. But where did they come from?

One theory is that most exoplanets are born as mini-Neptunes but some are stripped of their gas shells by radiation from host stars, leaving behind only a dense, rocky core. This theory predicts that our Galaxy has very few Earth-sized and smaller exoplanets known as Earths and mini-Earths. However, recent observations show this may not be the case.

To find out more, the astronomers used a simulation to track the evolution of these mysterious exoplanets. The model used thermodynamic calculations based on how massive their rocky cores are, how far they are from their host stars, and how hot the surrounding gas is.

"Contrary to previous theories, our study shows that some exoplanets can never build gaseous atmospheres to begin with," says co-author Eve Lee, Assistant Professor in the Department of Physics at McGill University and the McGill Space Institute.

The findings suggest that not all super-Earths are remnants of mini-Neptunes. Rather, the exoplanets were formed by a single distribution of rocks, born in a spinning disk of gas and dust around host stars. "Some of the rocks grew gas shells, while others emerged and remained rocky super-Earths," she says.

How mini-Neptunes and super-Earths are born

Planets are thought to form in a spinning disk of gas and dust around stars. Rocks larger than the moon have enough gravitational pull to attract surrounding gas to form a shell around its core. Over time this shell of gas cools down and shrinks, creating space for more surrounding gas to be pulled in, and causing the exoplanet to grow. Once the entire shell cools down to the same temperature as the surrounding nebular gas, the shell can no longer shrink and growth stops.

For smaller cores, this shell is tiny, so they remain rocky exoplanets. The distinction between super-Earths and mini-Neptunes comes about from the ability of these rocks to grow and retain gas shells.

Read more at Science Daily

Scientists create liquid crystals that look a lot like their solid counterparts

 A team at the University of Colorado Boulder has designed new kinds of liquid crystals that mirror the complex structures of some solid crystals -- a major step forward in building flowing materials that can match the colorful diversity of forms seen in minerals and gems, from lazulite to topaz.

The group's findings, published today in the journal Nature, may one day lead to new types of smart windows and television or computer displays that can bend and control light like never before.

The results come down to a property of solid crystals that will be familiar to many chemists and gemologists: Symmetry.

Ivan Smalyukh, a professor in the Department of Physics at CU Boulder, explained that scientists categorize all known crystals into seven main classes, plus many more sub-classes -- in part based on the "symmetry operations" of their internal atoms. In other words, how many ways can you stick an imaginary mirror inside of a crystal or rotate it and still see the same structure? Think of this classification system as Baskin-Robbins' 32 flavors but for minerals.

To date, however, scientists haven't been able to create liquid crystals -- flowing materials that are found in most modern display technologies -- that come in those same many flavors.

"We know everything about all the possible symmetries of solid crystals that we can make. There are 230 of them," said Smalyukh, senior author of the new study who is also a fellow of the Renewable and Sustainable Energy Institute (RASEI) at CU Boulder. "When it comes to nematic liquid crystals, the kind in most displays, we only have a few that have been demonstrated so far."

That is, until now.

In their latest findings, Smalyukh and his colleagues came up with a way to design the first liquid crystals that resemble monoclinic and orthorhombic crystals -- two of those seven main classes of solid crystals. The findings, he said, bring a bit more of order to the chaotic world of fluids.

"There are a lot of possible types of liquid crystals, but, so far, very few have been discovered," Smalyukh said. "That is great news for students because there's a lot more to find."

Symmetry in action

To understand symmetry in crystals, first picture your body. If you place a giant mirror running down the middle of your face, you'll see a reflection that looks (more or less) like the same person.

Solid crystals have similar properties. Cubic crystals, which include diamonds and pyrite, for example, are made up of atoms arranged in the shape of a perfect cube. They have a lot of symmetry operations.

"If you rotate those crystals by 90 or 180 degrees around many special axes, for example, all of the atoms stay in the right places," Smalyukh said.

But there are other types of crystals, too. The atoms inside monoclinic crystals, which include gypsum or lazulite, are arranged in a shape that looks like a slanted column. Flip or rotate these crystals all you want, and they still have only two distinct symmetries -- one mirror plane and one axis of 180-degree rotation, or the symmetry that you can see by spinning a crystal around an axis and noticing that it looks the same every 180 degrees. Scientists call that a "low-symmetry" state.

Traditional liquid crystals, however, don't display those kinds of complex structures. The most common liquid crystals, for example, are made up of tiny rod-shaped molecules. Under the microscope, they tend to line up like dry pasta noodles tossed into a pot, Smalyukh said.

"When things can flow they don't usually exhibit such low symmetries," Smalyukh said.

Order in liquids

He and his colleagues wanted to see if they could change that. To begin, the team mixed together two different kinds of liquid crystals. The first was the common class made up of rod-shaped molecules. The second was made up of particles shaped like ultra-thin disks.

When the researchers brought them together, they noticed something strange: Under the right conditions in the lab, those two types of crystals pushed and squeezed each other, changing their orientation and arrangement. The end result was a nematic liquid crystal fluid with symmetry that looks a lot like that of a solid monoclinic crystal. The molecules inside displayed some symmetry, but only one mirror plane and one axis of 180-degree rotation.

The group had created, in other words, a material with the mathematical properties of a lazulite or gypsum crystal -- but theirs could flow like a fluid.

"We're asking a very fundamental question: What are the ways that you can combine order and fluidity in a single material?" Smalyukh said.

And, the team's creations are dynamic: If you heat the liquid crystals up or cool them down, for example, you can morph them into a rainbow of different structures, each with their own properties, said Haridas Mundoor, lead author of the new paper. That's pretty handy for engineers.

"This offers different avenues that can modify display technologies, which may enhance the energy efficiency in performance of devices like smart phones," said Mundoor, a postdoctoral research associate at CU Boulder.

He and his colleagues are still nowhere near making liquid crystals that can replicate the full spectrum of solid crystals. But the new paper gets them closer than ever before -- good news for fans of shiny things everywhere.

Read more at Science Daily

Virtual reality helping to treat fear of heights

 Researchers from the University of Basel have developed a virtual reality app for smartphones to reduce fear of heights. Now, they have conducted a clinical trial to study its efficacy. Trial participants who spent a total of four hours training with the app at home showed an improvement in their ability to handle real height situations.

Fear of heights is a widespread phenomenon. Approximately 5% of the general population experiences a debilitating level of discomfort in height situations. However, the people affected rarely take advantage of the available treatment options, such as exposure therapy, which involves putting the person in the anxiety-causing situation under the guidance of a professional. On the one hand, people are reluctant to confront their fear of heights. On the other hand, it can be difficult to reproduce the right kinds of height situations in a therapy setting.

This motivated the interdisciplinary research team led by Professor Dominique de Quervain to develop a smartphone-based virtual reality exposure therapy app called Easyheights. The app uses 360° images of real locations, which the researchers captured using a drone. People can use the app on their own smartphones together with a special virtual reality headset.

Gradually increasing the height

During the virtual experience, the user stands on a platform that is initially one meter above the ground. After allowing acclimatization to the situation for a certain interval, the platform automatically rises. In this way, the perceived distance above the ground increases slowly but steadily without an increase in the person's level of fear.

The research team studied the efficacy of this approach in a randomized, controlled trial and published the results in the journal NPJ Digital Medicine. Fifty trial participants with a fear of heights either completed a four-hour height training program (one 60-minute session and six 30-minute sessions over the course of two weeks) using virtual reality, or were assigned to the control group, which did not complete these training sessions.

Before and after the training phase -- or the same period of time without training -- the trial participants ascended the Uetliberg lookout tower near Zurich as far as their fear of heights allowed them. The researchers recorded the height level reached by the participants along with their subjective fear level at each level of the tower. At the end of the trial, the researchers evaluated the results from 22 subjects who completed the Easyheights training and 25 from the control group.

The group that completed the training with the app exhibited less fear on the tower and was able to ascend further towards the top than they could before completing the training. The control group exhibited no positive changes. The efficacy of the Easyheights training proved comparable to that of conventional exposure therapy.

Therapy in your own living room

Researchers have already been studying the use of virtual reality for treating fear of heights for more than two decades. "What is new, however, is that smartphones can be used to produce the virtual scenarios that previously required a technically complicated type of treatment, and this makes it much more accessible," explains Dr. Dorothée Bentz, lead author of the study.

The results from the study suggest that the repeated use of a smartphone-based virtual reality exposure therapy can greatly improve the behavior and subjective state of well-being in height situations. People who suffer from a mild fear of heights will soon be able to download the free app from major app stores and complete training sessions on their own. However, the researchers recommend that people who suffer from a serious fear of heights only use the app with the supervision of a professional.

Read more at Science Daily

New weapon against resistant bacteria

 Every day, people die from simple infections even though they have been treated with antibiotics. This is because more and more bacteria have become resistant to the types of antibiotics that doctors can prescribe.

"It's a huge societal problem and a crisis that we must solve. For example, by developing new antibiotics that can defeat the resistant bacteria," says professor of chemistry at the Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Poul Nielsen.

Resistant bacteria are not only known from pig farms, where it is becoming increasingly difficult to keep the pigsties disease-free. Hospitals are also experiencing with increasing regularity that, for example, infectious diseases cannot be controlled in patients. Thus, an infection in a surgical wound can become life-threatening even if the operation went well.

According to Poul Nielsen, it is important to be at the forefront of the development because the list of resistant bacteria will only grow, which means that the treatment options will be reduced. It is therefore important to develop alternatives that can be used when the current antibiotics no longer work.

"Resistance can occur very quickly, and then it's essential that we're ready," he says.

Together with his research assistant Christoffer Heidtmann and associate professor Janne Kudsk Klitgaard from the Department of Biochemistry and Molecular Biology as well as Clinical Microbiology, he has developed a substance that has the potential to become a new effective antibiotic, and SDU has now taken out a patent for it.

Unlike traditional antibiotics such as penicillin, sulfonamides and tetracyclines, this antibiotic is from the pleuromutilin class.

The substance is developed in a medicinal chemistry project and recently published in the Journal of Medicinal Chemistry.

The substance fights both resistant enterococcus, streptococcus and staphylococcus bacteria. The substance and the pleuromutilin class do this via a unique mechanism of action, which also causes resistance to develop at a very slow pace.

So far, the substance has been tested on bacteria and human cells. The next step towards becoming an approved drug is animal studies and then clinical studies in humans.

"If this substance is to reach doctors and patients as a drug, comprehensive and cost-intensive further development efforts are needed, which we can only initiate under the auspices of the university.

"The big pharmaceutical companies have that kind of money, but they are traditionally not interested in this kind of tasks, because they are not financially attractive," says Poul Nielsen.

According to Poul Nielsen, there are several reasons why it is not financially attractive to develop new antibiotics:

Antibiotics are only taken for days or weeks. There is more money in drugs for chronically ill people, such as antidepressants or blood pressure medicine.

Newly developed antibiotics will be backups and not used until the current antibiotics no longer work. So earnings are not just around the corner.

The bacteria can also become resistant to a new antibiotic, and then it has to be taken off the market again.

"However, this doesn't change the fact that the world community is in dire need of new effective drugs against antibiotic resistance. Maybe we should consider this a societal task, rather than a task that will only be solved if it's financially attractive," says Poul Nielsen.

He and his colleagues hope that the work of further developing their new antibiotic can continue. Whether it will happen, and whether it will be in a public or private context, only time will tell.

Resistant bacteria in Denmark

MRSA (Methicillin-resistant Staphylococcus aureus) comes from pigs, among others. May cause wound infection, abscesses, impetigo, infection of bones and joints as well as blood poisoning.

ESBL (Extended-spectrum beta-lactamase) is an enzyme that causes resistant intestinal bacteria from especially poultry, which can cause inflammation of the bladder, inflammation of the renal pelvis and blood poisoning.

Clostridium difficile is an intestinal bacterium that causes diarrhoea and is transmitted through faeces. It forms spores, which means that water, soap and alcohol have no effect.

VRE (Vancomycin-resistant enterococci) are bacteria that are born resistant to a wide range of antibiotics. VRE typically causes inflammation of the bladder but can also cause inflammation of the heart valves (endocarditis).

Read more at Science Daily

Can super-Earth interior dynamics set the table for habitability?

 New research led by Carnegie's Yingwei Fei provides a framework for understanding the interiors of super-Earths -- rocky exoplanets between 1.5 and 2 times the size of our home planet -- which is a prerequisite to assess their potential for habitability. Planets of this size are among the most abundant in exoplanetary systems. The paper is published in Nature Communications.

"Although observations of an exoplanet's atmospheric composition will be the first way to search for signatures of life beyond Earth, many aspects of a planet's surface habitability are influenced by what's happening beneath the planet's surface, and that's where Carnegie researcher's longstanding expertise in the properties of rocky materials under extreme temperatures and pressures comes in," explained Earth and Planets Laboratory Director Richard Carlson.

On Earth, the interior dynamics and structure of the silicate mantle and metallic core drive plate tectonics, and generate the geodynamo that powers our magnetic field and shields us from dangerous ionizing particles and cosmic rays. Life as we know it would be impossible without this protection. Similarly, the interior dynamics and structure of super-Earths will shape the surface conditions of the planet.

With exciting discoveries of a diversity of rocky exoplanets in recent decades, are much-more-massive super-Earths capable of creating conditions that are hospitable for life to arise and thrive?

Knowledge of what's occurring beneath a super-Earth's surface is crucial for determining whether or not a distant world is capable of hosting life. But the extreme conditions of super-Earth-mass planetary interiors challenge researchers' ability to probe the material properties of the minerals likely to exist there.

That's where lab-based mimicry comes in.

For decades, Carnegie researchers have been leaders at recreating the conditions of planetary interiors by putting small samples of material under immense pressures and high temperatures. But sometimes even these techniques reach their limitations.

"In order to build models that allow us to understand the interior dynamics and structure of super-Earths, we need to be able to take data from samples that approximate the conditions that would be found there, which could exceed 14 million times atmospheric pressure," Fei explained. "However, we kept running up against limitations when it came to creating these conditions in the lab. "

A breakthrough occurred when the team -- including Carnegie's Asmaa Boujibar and Peter Driscoll, along with Christopher Seagle, Joshua Townsend, Chad McCoy, Luke Shulenburger, and Michael Furnish of Sandia National Laboratories -- was granted access to the world's most powerful, magnetically-driven pulsed power machine (Sandia's Z Pulsed Power Facility) to directly shock a high-density sample of bridgmanite -- a high-pressure magnesium silicate that is believed to be predominant in the mantles of rocky planets -- in order to expose it to the extreme conditions relevant to the interior of super-Earths.

A series of hypervelocity shockwave experiments on representative super-Earth mantle material provided density and melting temperature measurements that will be fundamental for interpreting the observed masses and radii of super-Earths.

The researchers found that under pressures representative of super-Earth interiors, bridgmanite has a very high melting point, which would have important implications for interior dynamics. Under certain thermal evolutionary scenarios, they say, massive rocky planets might have a thermally driven geodynamo early in their evolution, then lose it for billions of years when cooling slows down. A sustained geodynamo could eventually be re-started by the movement of lighter elements through inner core crystallization.

"The ability to make these measurements is crucial to developing reliable models of the internal structure of super-Earths up to eight times our planet's mass," Fei added. "These results will make a profound impact on our ability to interpret observational data."

Read more at Science Daily

Astronomers offer possible explanation for elusive dark-matter-free galaxies

 A team led by astronomers at the University of California, Riverside, has found that some dwarf galaxies may today appear to be dark-matter free even though they formed as galaxies dominated by dark matter in the past.

Galaxies that appear to have little to no dark matter -- nonluminous material thought to constitute 85% of matter in the universe -- complicate astronomers' understanding of the universe's dark matter content. Such galaxies, which have recently been found in observations, challenge a cosmological model used by astronomers called Lambda Cold Dark Matter, or LCDM, where all galaxies are surrounded by a massive and extended dark matter halo.

Dark-matter-free galaxies are not well understood in the astronomical community. One way to study the possible formation mechanisms for these elusive galaxies -- the ultradiffuse DF2 and DF4 galaxies are examples -- is to find similar objects in numerical simulations and study their time evolution and the circumstances that lead to their dark matter loss.

Jessica Doppel, a graduate student in the UC Riverside Department of Physics and Astronomy and the first author of research paper published in the Monthly Notices of the Royal Astronomical Society, explained that in a LCDM universe all galaxies should be dark matter dominated.

"That's the challenge," she said. "Finding analogs in simulations of what observers see is significant and not guaranteed. Beginning to pin down the origins of these types of objects and their often-anomalous globular cluster populations allows us to further solidify our theoretical framework of dark matter and galaxy formation and confirms that no alternative forms of dark matter are needed. We found cold dark matter performs well."

For the study, the researchers used cosmological and hydrodynamical simulation called Illustris, which offers a galaxy formation model that includes stellar evolution, supernova feedback, black hole growth, and mergers. The researchers found a couple of "dwarf galaxies" in clusters had similar stellar content, globular cluster numbers, and dark matter mass as DF2 and DF4. As its name suggests, a dwarf galaxy is small, comprising up to several billion stars. In contrast, the Milky Way, which has more than 20 known dwarf galaxies orbiting it, has 200 to 400 billion stars. Globular clusters are often used to estimate the dark matter content of galaxies, especially dwarfs.

The researchers used the Illustris simulation to investigate the origin of odd dwarf galaxies such as DF2 and DF4. They found simulated analogs to dark-matter-free dwarfs in the form of objects that had evolved within the galaxy clusters for a long time and lost more than 90% of their dark matter via tidal stripping -- the stripping away of material by galactic tidal forces.

"Interestingly, the same mechanism of tidal stripping is able to explain other properties of dwarfs like DF2 and DF4 -- for example, the fact that they are 'ultradiffuse' galaxies," said co-author Laura Sales, an associate professor of physics and astronomy at UCR and Doppel's graduate advisor. "Our simulations suggest a combined solution to both the structure of these dwarfs and their low dark matter content. Possibly, extreme tidal mass loss in otherwise normal dwarf galaxies is how ultradiffuse objects are formed."

In collaboration with researchers at the Max Planck Institute for Astrophysics in Germany, Sales' group is currently working with improved simulations that feature more detailed physics and a numerical resolution about 16 times better than the Illustris simulation.

"With these data, we will be able to extend our study to even lower-mass dwarfs, which are more abundant in the universe and expected to be more dark matter dominated at their centers, making them more challenging to explain," Doppel said. "We will explore if tidal stripping could provide a path to deplete dwarfs of their inner dark matter content. We plan to make predictions about the dwarfs' stellar, globular cluster, and dark matter content, which we will then compare to future observations."

The research team has already been awarded time at the W. M. Keck Observatory to help answer some of the questions pertaining to observations of dwarfs in the Virgo cluster.

Read more at Science Daily

Shining a light on the true value of solar power

 Beyond the environmental benefits and lower electric bills, it turns out installing solar panels on your house actually benefits your whole community. Value estimations for grid-tied photovoltaic systems prove solar panels are beneficial for utility companies and consumers alike.

For years some utility companies have worried that solar panels drive up electric costs for people without panels. Joshua Pearce, Richard Witte Endowed Professor of Materials Science and Engineering and professor of electrical and computer engineering at Michigan Technological University, has shown the opposite is true -- grid-tied solar photovoltaic (PV) owners are actually subsidizing their non-PV neighbors.

Most PV systems are grid-tied and convert sunlight directly into electricity that is either used on-site or fed back into the grid. At night or on cloudy days, PV-owning customers use grid-sourced electricity so no batteries are needed.

"Anyone who puts up solar is being a great citizen for their neighbors and for their local utility," Pearce said, noting that when someone puts up grid-tied solar panels, they are essentially investing in the grid itself. "Customers with solar distributed generation are making it so utility companies don't have to make as many infrastructure investments, while at the same time solar shaves down peak demands when electricity is the most expensive."

Pearce and Koami Soulemane Hayibo, graduate student in the Michigan Tech Open Sustainability Technology (MOST) Lab, found that grid-tied PV-owning utility customers are undercompensated in most of the U.S., as the "value of solar" eclipses both the net metering and two-tiered rates that utilities pay for solar electricity. Their results are published online now and will be printed in the March issue of Renewable and Sustainable Energy Reviews.

The value of solar is becoming the preferred method for evaluating the economics of grid-tied PV systems. Yet value of solar calculations are challenging and there is widespread disagreement in the literature on the methods and data needed. To overcome these limitations, Pearce and Hayibo's paper reviews past studies to develop a generalized model that considers realistic costs and liabilities utility companies can avoid when individual people install grid-tied solar panels. Each component of the value has a sensitivity analysis run on the core variables and these sensitivities are applied for the total value of solar.

The overall value of solar equation has numerous components:
 

• Avoided operation and maintenance costs (fixed and variable)
• Avoided fuel.
• Avoided generations capacity.
• Avoided reserve capacity (plants on standby that turn on if you have, for example, a large air conditioning load on hot day).
• Avoided transmission capacity (lines).
• Environmental and health liability costs associated with forms of electric generation that are polluting.

Pearce said one of the paper's goals was to provide the equations to determine the value of solar so individual utility companies can plug in their proprietary data to quickly make a complete valuation.

"It can be concluded that substantial future regulatory reform is needed to ensure that grid-tied solar PV owners are not unjustly subsidizing U.S. electric utilities," Pearce explains. "This study provides greater clarity to decision makers so they see solar PV is truly an economic benefit in the best interest of all utility customers."

Solar PV technology is now a profitable method to decarbonize the grid, but if catastrophic climate change is to be avoided, emissions from transportation and heating must also decarbonize, Pearce argues.

One approach to renewable heating is leveraging improvements in PV with heat pumps (HPs), and it turns out investing in PV+HP tech has a better rate of return than CDs or savings accounts.

To determine the potential for PV+HP systems in Michigan's Upper Peninsula, Pearce performed numerical simulations and economic analysis using the same loads and climate, but with local electricity and natural gas rates for Sault Ste. Marie, in both Canada and U.S. North American residents can profitably install residential PV+HP systems, earning up to 1.9% return in the U.S. and 2.7% in Canada, to provide for all of their electric and heating needs.

Read more at Science Daily

Emerging robotics technology may lead to better buildings in less time

 Emerging robotics technology may soon help construction companies and contractors create buildings in less time at higher quality and at lower costs.

Purdue University innovators developed and are testing a novel construction robotic system that uses an innovative mechanical design with advances in computer vision sensing technology to work in a construction setting.

The technology was developed with support from the National Science Foundation.

"Our work helps to address workforce shortages in the construction industry by automating key construction operations," said Jiansong Zhang, an assistant professor of construction management technology in the Purdue Polytechnic Institute. "On a construction site, there are many unknown factors that a construction robot must be able to account for effectively. This requires much more advanced sensing and reasoning technologies than those commonly used in a manufacturing environment."

The Purdue team's custom end effector design allows for material to be both placed and fastened in the same operation using the same arm, limiting the amount of equipment that is required to complete a given task.

Computer vision algorithms developed for the project allow the robotic system to sense building elements and match them to building information modeling (BIM) data in a variety of environments, and keep track of obstacles or safety hazards in the system's operational context.

"By basing the sensing for our robotic arm around computer vision technology, rather than more limited-scope and expensive sensing systems, we have the capability to complete many sensing tasks with a single affordable sensor," Zhang said. "This allows us to implement a more robust and versatile system at a lower cost."

Undergraduate researchers in Zhang's Automation and Intelligent Construction (AutoIC) Lab helped create this robotic technology.

The innovators worked with the Purdue Research Foundation Office of Technology Commercialization to patent the technology.

This work will be featured at OTC's 2021 Technology Showcase: The State of Innovation. The annual showcase, being held virtually this year Feb. 10-11, will feature novel innovations from inventors at Purdue and across the state of Indiana.

From Science Daily

Six previously FDA-approved drugs appear promising against SARS-CoV-2 in laboratory testing

 A team of investigators from the Republic of China has discovered that 6 drugs previously approved by the US Food and Drug Administration (FDA) for other indications could be repurposed to treat or prevent COVID-19. The research is published in Antimicrobial Agents and Chemotherapy, a journal of the American Society for Microbiology.

Using FDA-approved drugs saves time -- the drugs don't need to go through the FDA approval process again -- making them available quickly to treat patients who need them.

The research shows that the investigators screened 2 large drug libraries cumulatively containing 3,769 FDA-approved drugs and found drugs that can inhibit 2 protein-cutting enzymes, called proteases, that are essential to the replication of SARS-CoV-2.

The assays for testing the drugs involved growing the virus in petri dishes, applying each drug to different petri dishes containing the virus, and then conducting plaque reduction assays to determine each drug's effectiveness. The original outbreak strain, clade S, was used in the assays. ("Clade" is a technical term for a familial group.)

The researchers, led by corresponding author Po-Huang Liang, PhD, also plan to test the drugs against the dominant GR strain, which was the first variant to emerge, in late January or February, 2020, and the recent, highly contagious United Kingdom strain. Dr. Liang is research fellow and professor at the Institute of Biological Chemistry, Academia Sinica, Taiwan, Republic of China.

Their research also enables the investigators to better understand how coronavirus proteases recognize their substrates during replication. That will help them tweak the drugs they identified to be more effective inhibitors against the protease.

"Despite the variations of the virus strains emerging over the years, considering the significance of the 3CL protease in the viral replication, and the relatively low likelihood for this protein target to mutate, we aim to develop a broad spectrum of antiviral drugs using our platform, helping to prevent the emergence of future pathogenic SARS-CoV strains," said Dr. Liang.

Read more at Science Daily