Tag Archives: uv

How UV lights could end up saving crane species

Cranes are some of the most iconic bird species in the world — but they’re declining rapidly due to several factors, most of which involve human activity. Lethal collisions with power lines, for instance, are an ongoing threat to many crane populations. Several approaches have been tried to make these lines more visible, with varying degrees of success.

Now, a new study reports that adding UV lights — to which many birds are highly sensitive — can decrease crane collisions with power lines by 98%.

Cranes are a family of long-legged birds inhabiting all continents except Antarctica and, mysteriously, South America. Most species of cranes are dependent on wetlands and require large areas of open space. They tend to fly over large distances, although some species don’t migrate at all. For decades, researchers have reported that some cranes tend to fly into power lines, which is extremely dangerous to the birds and can easily be fatal.

James Dwyer and his colleagues from EDM International, an electrical utility company, created what they call the Avian Collision Avoidance System, or ACAS. The system essentially involves a set of UV lights mounted on power lines’ supporting structures.

They tested its effectiveness in 2018 at Nebraska’s Iain Nicolson Audubon Center, where a power line crosses right through a key habitat for migrating Sandhill Cranes. Randomly switching the ACAS on or off each night, researchers observed the behavior of cranes flying along the river at dusk and during the night. They documented 98% fewer collisions and 82% fewer dangerous flights when the ACAS was on.

“This project came about as a result of years of studying avian collisions with power lines throughout North America. My studies included collisions involving numerous species and families of birds, even on lines modified to industry standards to mitigate avian collisions, and I thought perhaps there could be a more effective approach,” says Dwyer.

Even so, the results were so good that they surprised even him.

“I did not imagine that the ACAS would have the effect that it did–a 98% reduction in collisions! I thought it would have some effect, but I didn’t dare think the ACAS would pretty much solve the Sandhill Crane collision problem at our study site on our first try,” he adds.

This is still a case study — the technology needs to be verified on multiple types of power lines and in multiple habitats. Dwyer also says that effectiveness ACAS needs to be investigated on other smaller species, which may also be at risk of collision with power lines.

“Because large carcasses like those of cranes and waterbirds are more easily noticed than smaller species like sparrows and warblers, collision studies have mostly focused on those larger species, and I fear that we may not understand the true distribution of species and habitats involved in the global avian collision problem.”

The study was published in The Condor: Ornithological Applications.

Robots might soon be sanitizing hospital rooms, killing far more bacteria than humans

With drug-resistant bacteria being more dangerous than ever, we need all the help we can get.

Image credits: Infection Prevention Technologies / Youtube.

Technology could help temper this ever-growing problem — hospital infections are running rampant, but they may be pushed back by ultraviolet (UV) Robots.

Current cleaning techniques, almost always manual, are nearly helpless in tackling resilient bacteria. This is where the disinfection robots enter the stage.

At certain wavelengths, UV light is mutagenic to bacteria, viruses, and other microorganisms. Particularly at wavelengths around 260 to 270 nanometers (the visible range is around 380 to 750 nanometers), UV light breaks molecular bonds within microorganismal DNA, severely disabling or killing the organisms.

The use of UV as a disinfectant isn’t new. It’s been used in medical sanitation and sterile work facilities since the mid-20th century, and more recently, it’s also been used to sterilize drinking and wastewater facilities.

Now, researchers have fitted UV lamps on disinfection robots which ensure full-room sterilization. Nursing homes, field hospitals, and biohazard zones could all be sterilized in a matter of minutes. The robots are faster and more efficient than human workers, and their ability to move around enables them to cover the entirety of the room, including shadowy areas and corners, as well as door handles and bed frames.

Infection Prevention Technologies (iPT), the company which built the robot, has reportedly tested the technology and found that after 10 minutes, the rooms were completely sterilized. This could go a long way towards reducing hospital infections.

“A 6-month, hospital-wide study showed a 34% drop in the incidence of healthcare associated infections with the use of the IPT 3200 UV robot and specially trained disinfection teams.” iPT claims.

Results have been presented in a new paper.

“One of the problems facing our healthcare system is hospital-associated infections,” says Nicholas Fitzkee, an independent scientist of the paper. Infections cost “thousands of lives and billions of dollars annually”, he adds.

Another advantage of the technology is that it requires minimal human intervention: just one person to guide and monitor the robot.

At the currently used levels, the radiation is harmless to humans. However, it’s still recommended that humans exit the room during the sterilization process.

According to the World Health Organization, drug-resistant pathogens are one of the biggest threats to mankind, and things are only expected to get worse. The CDC also warns that unusual germs with unusual drug-resistance are now widespread in the US. Technologies such as UV sanitizing could go a long way towards fighting that problem where it matters most (hospitals) and kill off some of the most resilient pathogens.

Puffin beak lighting up

Puffins have beaks that glow in UV light to bedazzle mates

When the mating season swings around, puffins get their best beaks out — but you need to bring out a UV lamp to see it.

Puffin.

Image credits Paul Wordingham / Flickr.

Researchers have long suspected that puffin (genus Fratercula) bills are more of a display piece than an efficient pecking machine. However, apart from the obvious pomp these organs are presented with, we didn’t have much evidence in favor of our theory. That all changed recently, when Jamie Dunning, an ornithologist affiliated with the University of Nottingham, showed that the bills are patterned with ridges that glow in ultraviolet (UV) light.

Blingy Bill

Birds don’t see the world exactly as we do. For starters, there’s quite a lot of evidence suggesting they can actually see magnetic fields. They also have the ability to see radiation at the UV end of the spectrum, which is radiation of higher energy than that in the visible spectrum of red, blue, and green. In other words, they can see some ‘colors’ that we cannot under normal circumstances — they become visible to us only under a UV light.

This knowledge has helped us discover patterns and colors in the plumage of other species that were invisible to the naked eye. It also led Dunning to suspect that the puffins may similarly hide an ace up their beak, given the structure’s blatant role as sexual advertisement. So, he set out to see if this was the case — starting with a dead puffin.

“I had one in the freezer – I’m the kind of guy people send dead birds to,” he said. “I had a UV light because we do a lot of spider stuff in the lab and a lot of them and scorpions glow in UV light, so I just turned the torch on the puffin and took a photo of what I saw.”

The ridges you see glowing here, called the lamella and the cere, (which appear yellow to us) are how puffins see each other during normal daylight hours, thanks to their ability to peer into the UV spectrum. The next step for the team was to make sure the effect could be seen in living specimens as well — a process which adorably involved creating special sunglasses to protect the bird’s eyes from the bright UV light, Dunning recounts.

Although he reported that living puffins showcase the same glowing ridges on their beaks, Dunning notes that their exact function is still unknown. It’s likely involved in signaling an individual’s sexual availability or prowess to others, not very dissimilar to a puffin-Tinder. Given the fact that puffins go through winter (i.e. outside of the mating season) with small and brown beaks makes it likely that they are solely involved in sexual signaling — but more research will be needed until we can say for sure.

“The obvious things with puffin bills – the bit we all know, the big beautiful orange bill, is that it actually comes off after the breeding season,” Mr Dunning says. “Their ornamentation develops specifically for the breeding season, so the clues are there it’s for sexual selection, and therefore the clues are there that this UV is an adaptation for sexual signalling.”

“With a puffin’s bill you don’t have to look at it very long to see that there’s hundreds of thousands of years of sexual selection there.”

Dunning plans to publish a paper detailing the findings with colleagues at the University of New Brunswick, and expects more research will follow.

Morning glory.

Morning glory seeds are hardy enough to survive in space, experiment reveals

Morning glory (family Convolvulaceae) seeds can survive through ridiculously high doses of UV radiation, a new study found, making them ideally suited for future colonies on high-UV planets such as Mars. They’re so good at it that these seeds might even survive the trip between planets unprotected — lending more confidence to the theory of panspermia.

Morning glory.

Give or take one decade ago, astronauts onboard the ISS placed about 2000 tobacco plant (genus Nicotiana) and arabidopsis (Arabidopsis thaliana) seeds on the outside of the station, then went about their business for 558 and 682 days. The plan was to see what effects long-term exposure to UV light, cosmic radiation, and the extreme temperature fluctuations out there would have on the tiny seeds. Since any of these factors on its own is lethal to most life as we know it, the general expectation was that they would die off.

Rad resistant

But at the end of the experiment in 2009, when the seeds were brought back down to Earth and planted, 20% of them germinated and grew into normal, healthy-looking plants. Which was surprising, to say the least. Now, 10 years after the experiment, an international team of researchers is trying to understand why.

“Seeds are ideally suited to storing life,” says David Tepfer, an emeritus plant biologist at the Palace of Versailles Research Center of the National Institute for Agronomic Research in France.

Together with Sydney Leach, an emeritus physicist at Paris-Meudon Observatory in France, Tepfer took a closer look at the DNA of some of these space-traveling seeds that didn’t make it to the germination trials. They were looking for a short section of genetic code which had been spliced into the seeds’ genome before their space journey. This bit of code was meant to act as an overall indicator of the exposed DNA’s level of damage, and the team found degradation both on it and the seeds’ genome. It’s possible that under the harsh conditions of space, distinct bits of the DNA were chemically fused like a stack of CDs melted together. The information stored in the DNA couldn’t be read afterward, inactivating the whole strand.

Still, one issue remained unaddressed. Given the inherent space constraints and transportation difficulties, the duo had to work with small seeds for the space tests “but small seeds are generally not capable of long-term survival in the soil,” the team writes. To see what the limitations of larger seeds were, the team performed a follow-up lab experiment with three types of seeds — tobacco and arabidopsis as a control sample and morning glory seeds “for their larger size, tougher seed coats, and longevity in the soil.” They then blasted these seeds with a huge amount of radiation — roughly 6 million times as much UV as is typically used to purge drinking water of any pathogens. The tobacco and arabidopsis seeds didn’t make it, but morning glory seeds germinated normally after the exposure.

Pack some sunscreen

The team writes that their survival likely comes down to a protective layer coating the morning glory seeds, which contains flavonoids (compounds commonly found in wine and tea that act as natural sunscreens) and insulates them from the brunt of UV radiation.

Barricaded behind these flavonoids, seeds could slumber their way from one planet to the next and, assuming they don’t burn on reentry or land on a planet where everything is toxic and awful for them, take root and jumpstart life around the Universe — a process known as panspermia. Tepfer also says it’s worth investigating if feeding animals a diet rich in flavonoids can lend them resistance to UV, potentially keeping them safe on interplanetary travels.

Feeding animals a high-flavonoid diet might confer resistance to UV light and make them better suited for interplanetary travel, Tepfer suggests. “They might become more ultraviolet-resistant,” he says. “Red wine or green tea, anyone?”

The paper “Survival and DNA Damage in Plant Seeds Exposed for 558 and 682 Days outside the International Space Station” has been published in the journal Astrobiology.

 

Researchers found a supermassive black hole choking on its meal

Scientists have found a supermassive black hole that seems to have bit more than it can chew. At the center of a galaxy some 300 million light years away from Earth, the black hole is straining to absorb the mass of a star it recently collapsed, “chocking” on its remains.

Artist’s impression of a supermassive black hole at a galaxy’s center. The blue color represents radiation pouring out from material very close to the black hole.
Image credits NASA/JPL-Caltech.

A team of researchers including members from MIT and NASA’s Goddard Space Flight Center have recently reported picking up on a peculiar “tidal disruption flare”, a massive burst of electromagnetic energy released when a black hole collapses a hapless star. The flare, named ASASSN-14li, first hit our sensors on Nov. 11, 2014, and researchers have since pointed all kinds of telescopes towards the source to learn as much as possible about how black holes evolve.

Led by MIT postdoc at the Kavli Institute for Astrophysics and Space Research Dheeraj Pasham, the team looked at data obtained with two different telescopes and found a strange pattern in the energy levels of the flare. As the supermassive black hole (I’ll just call it a SBH from not on) first began absorbing the former star’s matter, the team picked up on slight variations in the visible and ultraviolet intervals of the electromagnetic spectrum. Which in itself isn’t that weird — we’ll get to it in a moment. But the same pattern of fluctuations was picked up again 32 days later, this time in the X-ray band.

A flare of gluttony

So first off let’s get to know what these flares are and how they usually behave.

As I’ve said, tidal disruption flares are huge bursts of energy released when a black hole’s immense gravitational pull rips a star apart. The bursts propagate all over the electromagnetic spectrum, from radio, visible, and UV all the way to X-ray and gamma ray intervals. They’re pretty rare, so we didn’t witness that many of them despite the fact that they really stand out. But when we do, it’s a dead give away for hidden black holes — which would be almost impossible to spot otherwise.

“You’d have to stare at one galaxy for roughly 10,000 to 100,000 years to see a star getting disrupted by the black hole at the center,” Pasham, who’s also the paper’s first author, says.

“Almost every massive galaxy contains a supermassive black hole. But we won’t know about them if they’re sitting around doing nothing, unless there’s an event like a tidal disruption flare.”

So in a way we were lucky, but our sensors were also ready for it. The ASASSN-14li flare was picked up by the ASASSN (All Sky Automated Survey for SuperNovae) network of automated telescopes. Soon after, researchers pointed other telescopes towards the black hole, including the X-ray telescope aboard NASA’s Swift satellite — designed to monitor the sky for bursts of extremely high energy.

Artist’s rendering of the supermassive black hole that generated the flare and its accretion disk.
Image credits NASA / Swift / Aurore Simonnet, Sonoma State University.

“Only recently have telescopes started ‘talking’ to each other, and for this particular event we were lucky because a lot of people were ready for it,” Pasham says. “It just resulted in a lot of data.”

By looking at all the data they gathered on the event, Pasham and his team answered a long-standing mystery: where did these bursts of light originate in flares? By modeling a black hole’s dynamics, scientists have previously been able to explain that as a black hole rips its star apart, the resulting material can produce X-ray emissions very close to the event horizon. But the source for the visible and UV light proved elusive.

The team studied the 270 days after ASASSN-14li was first detected, with particular emphasis on the X-ray and optical/UV data taken by the Swift satellite and the Las Cumbres Observatory Global Telescope. Two broad peaks in the X-ray band were identified (one around day 50, and the other around day 110), and one short dip (around day 80). This was the exact same pattern they recorded for the visible/UV spectrum just 32 days earlier.

Their next step was to run simulations of the flare produced by a star collapsing next to a black hole and the resulting accretion disc (similar to how planets get them) — along with its presumed speed, size, and the rate which material falls onto the black hole.

Tug of war

 

The results suggest these energy fluctuations are a kind of electromagnetic echo. After the star was torn apart, its remains started swirling the supermassive black hole. As it drew nearer to the event horizon, the cloud of matter accelerated and became more tightly packed, releasing bursts of UV and visible light when its particles collided at high speeds. As the matter was pulled closer to the black hole it got even faster and denser, which also made it heat up. In this excited state of matter close to absorption into the event horizon, the collisions produced X- and gamma ray bursts instead of the lower-energy visible and UV bursts.

In the case of ASASSN-14li, this process happened much more slowly that usually because the great quantity of matter proved a bit too much for the black hole to chew in a single bite.

 

“In essence, this black hole has not had much to feed on for a while, and suddenly along comes an unlucky star full of matter.” Pasham explains. “What we’re seeing is, this stellar material is not just continuously being fed onto the black hole, but it’s interacting with itself — stopping and going, stopping and going. This is telling us that the black hole is ‘choking’ on this sudden supply of stellar debris.”

“For supermassive black holes steadily accreting, you wouldn’t expect this choking to happen. The material around the black hole would be slowly rotating and losing some energy with each circular orbit,” he adds.

“But that’s not what’s happening here. Because you have a lot of material falling onto the black hole, it’s interacting with itself, falling in again, and interacting again. If there are more events in the future, maybe we can see if this is what happens for other tidal disruption flares.”

The full paper “Optical/UV-to-X-Ray Echoes from the Tidal Disruption Flare ASASSN-14li” has been published in the journal Astrophysical Journal Letters.

 

 

Benefits of sun exposure may outweigh the downsides

Lately, the sun has received a lot of thrash talk for the harm it causes with exposure, increasing the risk of skin cancer. But a new study conducted by researchers from the University of Edinburgh has shown that the benefits of exposure to UV rays may be greater than the risk of getting skin cancer, according to a proof-of-principle study.

sun

A proof of principle study (also called a proof of concept) is a realization of a certain method or idea to demonstrate its feasibility, or just a demonstration in principle. They examined the effect of nitric oxide, which is released into the blood vessels when UV rays come into contact with your skin, and its effect on blood pressure. Participants in the study were asked to sit beneath a special lamp for 20 minutes, with their blood pressure monitored as they waited.

During the first session, they were exposed to both heat and UV, while in the second one they were only exposed to heat, without the UV. Participants’ blood pressures fell and their heart rates rose in the session involving both UV rays and heat, but did not do so during the time they were only exposed to the heat, proving a direct causality between UV exposure and blood pressure.

“Deaths from CVD (cardiovascular disease) and stroke are 60 to 100 times higher than from skin cancers in northern Europe,” study authors noted. “This study provides a mechanistic explanation for the inverse correlation between sunlight exposure and CVD mortality. Sunlight has beneficial effects independently of vitamin D synthesis.”

The findings were presented recently at the International Investigative Dermatology 2013 meeting in Edinburgh.

Via Dermatology Times

Tomorrow’s camera is flash free, regardless of light conditions

As any amateur photographer can tell you, in order to take a clear picture, you require a good light source; so in poor light conditions, the solution was the intense flash. However, there are some obvious disadvantages.

Still, computer scientist Rob Fergus started thinking if we actually need such an intense light source, or if we could actually develop some sort of invisible flash that would solve the inconvenient that come with the traditional camera flash.

F is a multi spectral flash, A is using ambiental lighting, which is way lower than it should be, R is a combined version of the two, and L is a reference long exposure shot

So one year later, the end result was a camera that emits and records light outside the visible spectrum. Practically, the prototype emits a flash, but you just don’t see it, and the photographs are as good as old-school flash ones. How does it work ? Well, usually, cameras have a filter that prevents any type of light from the infrared spectrum.  For this innovative camera, Fergus replaced the filter; the UV however, was a little trickier. His camera could already detect UV, but sending it out, that was a real challenge. So he employed the help of some hobbyists that use UV photography to reveal hidden patterns on flowers: landing strips for insects, polinators, etc.

So the camera is done, but is it any good ? Well, it most definitely is. as you can see for yourself.

“Most pictures you take with a flash look quite crappy,” says Ankit Mohan, an expert in camera technology at the Massachusetts Institute of Technology says. “They look kind of flat, you get the red-eye effect, and one part of the scene is always much brighter than another part. But the problem of capturing a picture with no flash is that you don’t get detail. By combining the two you get the best of both worlds.”

Despite the comfort advantages it provides, this development is also quite useful in some fields.

Cramer Gallimore, a professional photographer based in North Carolina, believes dark-flash photography has great potential. “You might be able to take high-quality photographs of wildlife without disturbing them,” Gallimore says, “and for forensic photography, it would be very useful to have technology like this that could switch between infrared technology and visible light photography to record certain traces of human activity at a crime scene.”

Source: Popular Mechanics