Month: March 2016

Why Fast Radio Bursts Have Astronomers So Puzzled

For the first time, scientists have detected repeat “fast radio bursts” from the same spot, likely located well beyond the edge of our Milky Way galaxy.

They suspect the bursts come from an extremely powerful object that occasionally produces multiple bursts in under a minute.

All fast radio bursts (FRBs) detected before this one appear to have been one-off events. Because of that, most theories about the origin of these mysterious pulses have involved cataclysmic incidents that destroy their source–a star exploding in a supernova, for example, or a neutron star collapsing into a black hole.

The new finding, reported in Nature, shows that at least some FRBs have other origins.

FRBs, which last just a few thousandths of a second, have puzzled scientists since they were first reported nearly a decade ago. Despite extensive follow-up efforts, astronomers until now have searched in vain for repeat bursts.

That changed November 5, 2015, when McGill University PhD student Paul Scholz was sifting through results from observations performed with the Arecibo radio telescope in Puerto Rico–the world’s largest radio telescope. The new data, gathered in May and June and run through a supercomputer, showed several bursts with properties consistent with those of an FRB detected in 2012.

The Arecibo telescope and its suspended support platform of radio receivers is shown amid a starry night. From space, a sequence of millisecond-duration radio flashes are racing towards the dish, where they will be reflected and detected by the radio receivers. Such radio signals are called fast radio bursts, and Arecibo is the first telescope to see repeat bursts from the same source. Click or tap for larger image. (Credit: Danielle Futselaar)
The Arecibo telescope and its suspended support platform of radio receivers is shown amid a starry night. From space, a sequence of millisecond-duration radio flashes are racing towards the dish, where they will be reflected and detected by the radio receivers. Such radio signals are called fast radio bursts, and Arecibo is the first telescope to see repeat bursts from the same source. Click or tap for larger image. (Credit: Danielle Futselaar)

The repeat signals were surprising–and “very exciting,” Scholz says. “I knew immediately that the discovery would be extremely important in the study of FRBs.” As his office mates gathered around his computer screen, Scholz pored over the remaining output from specialized software used to search for pulsars and radio bursts. He found that there were a total of 10 new bursts.

The finding suggests that the bursts come from a very exotic object, such as a rotating neutron star having unprecedented power that enables the emission of extremely bright pulses, the researchers say. It is also possible that the finding represents the first discovery of a sub-class of the cosmic fast-radio-burst population.

“Not only did these bursts repeat, but their brightness and spectra also differ from those of other FRBs,” says Laura Spitler, first author of the new paper and a postdoctoral researcher at the Max Planck Institute for Radio Astronomy in Bonn, Germany.

Scientists believe that these and other radio bursts originate from distant galaxies, based on the measurement of an effect known as plasma dispersion. Pulses that travel through the cosmos are distinguished from man-made interference by the influence of interstellar electrons, which cause radio waves to travel more slowly at lower radio frequencies.

The 10 newly discovered bursts, like the one detected in 2012, have three times the maximum dispersion measure that would be expected from a source within the Milky Way.

Intriguingly, the most likely implication of the new Arecibo finding–that the repeating FRB originates from a very young extragalactic neutron star–is at odds with the results of a study published last week in Nature by another research team. That paper suggested FRBs are related to cataclysmic events, such as short gamma-ray bursts, which can’t generate repeat events.

“However, the apparent conflict between the studies could be resolved, if it turns out that there are at least two kinds of FRB sources,” says McGill physics professor Victoria Kaspi, a senior member of the international team that conducted the Arecibo study.

In future research, the team hopes to identify the galaxy where the radio bursts originated. To do so, they will need to detect bursts using radio telescopes with far more resolving power than Arecibo, a National Science Foundation-sponsored facility with a dish that spans 305 meters and covers about 20 acres. Using a technique called interferometry, performed with radio telescope arrays spread over large geographical distances, the astronomers may be able to achieve the needed resolution.

“Once we have precisely localized the repeater’s position on the sky, we will be able to compare observations from optical and X-ray telescopes and see if there is a galaxy there,” says Jason Hessels, associate professor at the University of Amsterdam and the Netherlands Institute for Radio Astronomy as well as corresponding author of the Nature paper. “Finding the host galaxy of this source is critical to understanding its properties,” he adds.

Canada’s CHIME telescope could help unravel the puzzle, adds Kaspi, who is director of the McGill Space Institute. Thanks to the novel design of the soon-to-be completed apparatus, it should have the capability to detect dozens of fast radio bursts per day, she says.

“CHIME will further our quest to understand the origin of this mysterious phenomenon, which has the potential to provide a valuable new probe of the universe.”

Republished from Futurity.org as a derivative work under the Attribution 4.0 International license. Original article posted to Futurity by .

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Zika: Aedes aegypti mosquitoes love biting humans, and that’s why they spread viruses so well

Megan Wise de Valdez, Texas A&M-San Antonio

While researchers work to develop a Zika virus vaccine to combat the outbreak spreading through South America, efforts to control the spread of the virus are focusing on the mosquito Aedes aegypti.

Aedes aegypti mosquitoes. (Credit: Paulo Whitaker/Reuters)

This particular mosquito is especially good at transmitting disease from one human to another. Besides Zika, this mosquito is also a vector for dengue, yellow fever and Chikungunya viruses.

I’ve been studying Ae. aegypti – where it lives and how it behaves – for 15 years. Aedes aegypti is adapted to live in close proximity with humans, and this close association likely contributes to the severity of this outbreak.

Aedes aegypti in a location near you?

Aedes aegypti is an invasive species to the Americas. It originated in Africa, and is thought to have been brought over with the early slave trade ships in the 15th through 17th century.

This mosquito is found in tropical and subtropical areas, which include all of Central and much of South America. In the U.S. it can be found readily in the Southeast and some small pockets in the Southwest, but not in areas that experience cold or freezing temperatures and more pronounced changes in daylight.

Aedes aegypti is a daytime biter, which means it’s active when its preferred food choice – human beings – are out and about.

Revelers wearing costumes representing Ae. aegypti and insect repellent, at a carnival party in Rio de Janeiro, February 6, 2016. (Credit: Pilar Olivares/Reuters)

Aedes aegypti just loves people

There are many species of mosquitoes, but not all of them spread diseases in people. Some prefer to feed on other mammals or birds. Ae. aegypti, however, prefers to feed on human beings. In fact, Aedes aegypti prefers human blood over that of other animals, which increases its ability to transmit viruses from person to person.

All mosquitoes are attracted to the carbon dioxide in our breath because it clues them into a live, breathing blood source.

Aedes aegypti females also detect odor cues from our sweat. They are attracted to the lactic acid and ammonia on our breath and skin, as well as the fatty acids secreted by the sebaceous glands at the base of our hair follicles (that would be the stuff that makes our hair look and smell oily).

Male Ae. aegypti feed on nectar and sugar, not blood, but they also can detect these odor cues so they can find potential mates that are hanging around humans.

While people generally smell good to female Ae. aegypti mosquitoes, some people smell especially good.

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Eying exomoons in the search for E.T.

Bryan Gaensler, University of Toronto.

When I was young, the only planets we knew about were the ones in our own solar system.

Astronomers presumed that many of the other stars in the night sky had planets too, but this was sheer speculation. We could never know for sure, the thinking went, because such planets were ridiculously small and faint. To ever see or study them seemed a complete impossibility. “Extrasolar planets,” or “exoplanets,” were a staple of science fiction, but not of professional astrophysics.

It’s hard to believe that there was once such a simple time. The first definitive detection of an exoplanet was in 1991, identified by the tiny wobbles experienced by the parent star as its exoplanet swung around it. Since then, the field has exploded. There are now around 1,600 confirmed exoplanets, with almost 4,000 other known candidates. There are exoplanets smaller than Mercury, and others many times bigger than Jupiter. Their orbits around their parent stars range from a few hours to hundreds of years. And the ones we know about are just a tiny fraction of the more than 100 billion exoplanets we now believe are spread throughout our Milky Way galaxy.

But while the golden age of exoplanets has barely begun, an exciting additional chapter is also taking shape: the hunt for exomoons.

Beyond Earth-like planets to exomoons

An exomoon is a moon orbiting a planet, which in turn is orbiting another star. You may not have ever heard of exomoons before now. But if you’re a fan of films such as “Avatar,” “Return of the Jedi” or “Prometheus,” this should be familiar territory: in all three cases, most of the action takes place on an exomoon.

But what about real life? How many exomoons do we know of? At the moment, zero.


Endor: not all exomoons come with ewoks.  Star Wars: Episode VI Return of the Jedi

But the race is on to find the real-life analogs of Endor and Pandora.

You might think searching for tiny rocks orbiting distant planets around faint stars hundreds or thousands of light years away is the ultimate example of an obscure academic pursuit. But exomoons are poised to become a big deal.

The whole reason exoplanets are exciting is that they’re a path to answering one of the grandest questions of all: “Are we alone?” As we find more and more exoplanets, we eagerly ask whether life could exist there, and whether this planet is anything like Earth. However, so far we’ve yet to find an exact match to Earth, nor can we yet really know for sure whether any exoplanet, Earth-like or otherwise, hosts life.

Enter exomoons in the search for life

There are several reasons why exomoons, these little distant worlds, may be the key to finding life elsewhere in the universe.

First, there’s the stark reality that life on Earth may not have happened at all without the starring role played by our own moon.

The Earth’s axis is tilted by 23.5 degrees relative to its motion around the sun. This tilt gives us seasons, and because this tilt is relatively small, seasons on Earth are mild: most places never get impossibly hot or unbearably cold. One thing that has been crucial for life is that this tilt has stayed the same for very long periods: for millions of years, the angle of tilt has varied by only a couple of degrees.

What has kept the Earth so steady? The gravity of our moon.

In contrast, Mars only has two tiny moons, which have negligible gravity. Without a stabilizing influence, Mars has gradually tumbled back and forth, its tilt ranging between 0 and 60 degrees over millions of years. Extreme changes in climate have resulted. Any Martian life that ever existed would have found the need to continually adapt very challenging.

Without our moon, the Earth, too, would likely have been subject to chaotic climate conditions, rather than the relative certainty of the seasons that stretches back deep into the fossil record.

The gravity of the moon also produces the Earth’s tides. Billions of years ago, the ebb and flow of the oceans produced an alternating cycle of high and low salt content on ancient rocky shores. This recurring cycle could have enabled the unique chemical processes needed to generate the first DNA-like molecules.


Moons might contribute to a planet’s habitability. NASA/JPL-Caltech/Space Science Institute, CC BY-ND

Exomoons might have Earth-like environments

Overall, as we continue to hunt for another Earth somewhere out there, it seems likely that a twin of Earth, but without a moon accompanying it, would not look familiar. Finding exomoons is a key part of finding somewhere like here.

Meanwhile, we shouldn’t be discouraged by the fact that most exoplanets found so far are bloated gaseous beasts, with hostile environments unlikely to support life as we know it. What we don’t know yet, crucially, is whether these exoplanets have moons. This prospect is exciting, because exomoons are expected to be smaller rocky or icy bodies, possibly hosting oceans and atmospheres.

This is hardly speculation: Titan (a moon of Saturn) has a thick atmosphere even denser than Earth’s, while underground oceans are thought to exist on Enceladus (another moon of Saturn) and on Europa and Ganymede (both moons of Jupiter). Thus, if there is any other life out there somewhere, it may well not be found on a distant planet, but on a distant moon.

The hunt is on. While exomoons are too faint to see directly, astronomers are deploying ingenious indirect techniques in their searches. Those moons are assuredly out there by the billions – and soon we will find them. It won’t be too much longer before these tiny worlds help us answer huge questions.

The ConversationBryan Gaensler, Director, Dunlap Institute for Astronomy and Astrophysics, University of Toronto

This article was originally published on The Conversation. Read the original article.

Featured Image Credit: Maxwell Hamilton/flickr, CC BY

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Hubble Sees Farthest Galaxy So Far [Video]

An international team of astronomers has pushed the Hubble Space Telescope to its apparent limits and detected the farthest galaxy ever seen, setting a cosmic distance record in the process. The galaxy, known as GN-z11, is a surprisingly bright galaxy that was in it’s infancy at the time the light Hubble detected arrived on its instruments was emitted from the galaxy 13.4 billion years ago.

“We’ve taken a major step back in time, beyond what we’d ever expected to be able to do with Hubble. We see GN-z11 at a time when the universe was only three percent of its current age,” explained principal investigator Pascal Oesch of Yale University in a press announcement published on the NASA website. The team includes scientists from Yale University, the Space Telescope Science Institute (STScI), and the University of California.

Astronomers are closing in on the first galaxies that formed in the universe. The new Hubble observations take astronomers into a realm that was once thought to be only reachable with NASA’s upcoming James Webb Space Telescope.

This measurement provides strong evidence that some unusual and unexpectedly bright galaxies found earlier in Hubble images are really at extraordinary distances. Previously, the team had estimated GN-z11’s distance by determining its color through imaging with Hubble and NASA’s Spitzer Space Telescope. Now, for the first time for a galaxy at such an extreme distance, the team used Hubble’s Wide Field Camera 3 to precisely measure the distance to GN-z11 spectroscopically by splitting the light into its component colors.

Astronomers measure large distances by determining the “redshift” of a galaxy. This phenomenon is a result of the expansion of the universe; every distant object in the universe appears to be receding from us because its light is stretched to longer, redder wavelengths as it travels through expanding space to reach our telescopes. The greater the redshift, the farther the galaxy.

Hubble spectroscopically confirms farthest galaxy to date. Click or tap for larger image. Credits: NASA, ESA, and A. Feild (STScI)
Hubble spectroscopically confirms farthest galaxy to date. Click or tap for larger image.
Credits: NASA, ESA, and A. Feild (STScI)

“Our spectroscopic observations reveal the galaxy to be even farther away than we had originally thought, right at the distance limit of what Hubble can observe,” said Gabriel Brammer of STScI, second author of the study.

Before astronomers determined the distance for GN-z11, the most distant galaxy measured spectroscopically had a redshift of 8.68 (13.2 billion years in the past). Now, the team has confirmed GN-z11 to be at a redshift of 11.1, nearly 200 million years closer to the Big Bang. “This is an extraordinary accomplishment for Hubble. It managed to beat all the previous distance records held for years by much larger ground-based telescopes,” said investigator Pieter van Dokkum of Yale University. “This new record will likely stand until the launch of the James Webb Space Telescope.”

The combination of Hubble’s and Spitzer’s imaging reveals that GN-z11 is 25 times smaller than the Milky Way and has just one percent of our galaxy’s mass in stars. However, the newborn GN-z11 is growing fast, forming stars at a rate about 20 times greater than our galaxy does today. This makes an extremely remote galaxy bright enough for astronomers to find and perform detailed observations with both Hubble and Spitzer.

The results reveal surprising new clues about the nature of the very early universe. “It’s amazing that a galaxy so massive existed only 200 million to 300 million years after the very first stars started to form. It takes really fast growth, producing stars at a huge rate, to have formed a galaxy that is a billion solar masses so soon,” explained investigator Garth Illingworth of the University of California, Santa Cruz.

The animation below shows the location of galaxy GN-z11, which is the farthest galaxy ever seen. The video begins by locating the Big Dipper, then showing the constellation Ursa Major. It then zooms into the GOODS North field of galaxies, and ends with a Hubble image of the young galaxy.

These findings provide a tantalizing preview of the observations that the James Webb Space Telescope will perform after it is launched into space in 2018. “Hubble and Spitzer are already reaching into Webb territory,” Oesch said.

“This new discovery shows that the Webb telescope will surely find many such young galaxies reaching back to when the first galaxies were forming,” added Illingworth.

This discovery also has important consequences for NASA’s planned Wide-Field Infrared Survey Telescope (WFIRST), which will have the ability to find thousands of such bright, very distant galaxies.

Source: NASA.gov. Republished in compliance with NASA’s media usage guidelines and per public domain rights to public information.

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Monkeys Drive Robotic Wheelchairs Just by Thinking

In an amazing study that will likely have profound implications for wheelchair-bound people, Duke Health neuroscientists have developed a brain-machine interface (BMI) that enables monkeys to drive a robotic wheelchair using just their thoughts. The researchers were able to help the monkeys learn how to navigate their wheelchairs to a goal after implanting hundreds of hair-thin electrodes in their brains and then training a computer system to translate the monkeys thought signals into directional movement for the wheelchair.

A fascinating news release on the Science Daily website delves into the incredible details and results:

The BMI uses signals from hundreds of neurons recorded simultaneously in two regions of the monkeys’ brains that are involved in movement and sensation. As the animals think about moving toward their goal — in this case, a bowl containing fresh grapes — computers translate their brain activity into real-time operation of the wheelchair.

The interface, described in the March 3 issue of the online journal Scientific Reports, demonstrates the future potential for people with disabilities who have lost most muscle control and mobility due to quadriplegia or ALS, said senior author Miguel Nicolelis, M.D., Ph.D., co-director for the Duke Center for Neuroengineering.

“In some severely disabled people, even blinking is not possible,” Nicolelis said. “For them, using a wheelchair or device controlled by noninvasive measures like an EEG (a device that monitors brain waves through electrodes on the scalp) may not be sufficient. We show clearly that if you have intracranial implants, you get better control of a wheelchair than with noninvasive devices.”

Scientists began the experiments in 2012, implanting hundreds of hair-thin microfilaments in the premotor and somatosensory regions of the brains of two rhesus macaques. They trained the animals by passively navigating the chair toward their goal, the bowl containing grapes. During this training phase, the scientists recorded the primates’ large-scale electrical brain activity. The researchers then programmed a computer system to translate brain signals into digital motor commands that controlled the movements of the wheelchair.

As the monkeys learned to control the wheelchair just by thinking, they became more efficient at navigating toward the grapes and completed the trials faster, Nicolelis said.

In addition to observing brain signals that corresponded to translational and rotational movement, the Duke team also discovered that primates’ brain signals showed signs they were contemplating their distance to the bowl of grapes.

“This was not a signal that was present in the beginning of the training, but something that emerged as an effect of the monkeys becoming proficient in this task,” Nicolelis said. “This was a surprise. It demonstrates the brain’s enormous flexibility to assimilate a device, in this case a wheelchair, and that device’s spatial relationships to the surrounding world.”

The trials measured the activity of nearly 300 neurons in each of the two monkeys. The Nicolelis lab previously reported the ability to record up to 2,000 neurons using the same technique. The team now hopes to expand the experiment by recording more neuronal signals to continue to increase the accuracy and fidelity of the primate BMI before seeking trials for an implanted device in humans, he said.

In addition to Nicolelis, study authors include Sankaranarayani Rajangam; Po-He Tseng; Allen Yin; Gary Lehew; David Schwarz; and Mikhail A. Lebedev.

The National Institutes of Health (DP1MH099903) funded this study. The Itau Bank of Brazil provided research support to the study as part of the Walk Again Project, an international non-profit consortium aimed at developing new assistive technologies for severely paralyzed patients.

The study was published in Scientific Reports, and the infographic below shows the methodology of the work:

monkey-wheelchair-driving
(A) The mobile robotic wheelchair, which seats a monkey, was moved from one of the three starting locations (dashed circles) to a grape dispenser. The wireless recording system records the spiking activities from the monkey’s head stage, and sends the activities to the wireless receiver to decode the wheelchair movement. (B) Schematic of the brain regions from which we recorded units tuned to either velocity or steering. Red dots correspond to units in M1, blue from PMd and green from the somatosensory cortex. (C) Three video frames show Monkey K drive toward the grape dispenser. The right panel shows the average driving trajectories (dark blue) from the three different starting locations (green circle) to the grape dispenser (red circle). The light blue ellipses are the standard deviation of the trajectories. Click/tap for larger image.

Sources: ScienceDaily.com – “Monkeys drive wheelchairs using only their thoughts“; Nature.com Scientific Reports: “Wireless Cortical Brain-Machine Interface for Whole-Body Navigation in Primates“

Featured Image Credit: Shawn Rocco/ Duke Health

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Chance Discovery in UK is One of the Most Important Archaeological Finds in Decades

A chance finding of an ancient object by a British metal detector enthusiast has led to the discovery of a previously unknown Anglo-Saxon settlement which appears to be a monastic or trading center from the 8th century. The site, which was in fact an island in the 8th century, was discovered in a field outside of Little Carlton near Louth, Lincolnshire, and is yielding numerous artifacts from the settlement. Archaeologists from the University of Sheffield have deemed it one of the most important finds in decades.

A press release from the University of Sheffield website supplies all of the intriguing details:

A glass counter decorated with twisted colorful strands found at the site. Click or tap for larger image. (Credit: Portable Antiquities Scheme)
A glass counter decorated with twisted colorful strands found at the site. Click or tap for larger image. (Credit: Portable Antiquities Scheme)

The remains of an Anglo-Saxon island have been uncovered in one of the most important archaeological finds in decades.

The island which was home to a Middle Saxon settlement was found at Little Carlton near Louth, Lincolnshire by archaeologists from the University of Sheffield.

It is thought the site is a previously unknown monastic or trading centre but researchers believe their work has only revealed an enticing glimpse of the settlement so far.

The exciting discovery was made after a local metal detectorist Graham Vickers reported an intriguing item to the Lincolnshire Finds Liaison Officer (FLO), Dr Adam Daubney, from the Portable Antiquities Scheme which encourages the voluntary recording of archaeological objects found by members of the public in England and Wales.

Mr Vickers unearthed a silver stylus, which is an ornate writing tool dating back to the 8th century, from a disturbed plough field.

This was the first of many unusual items found at the site which held important clues to the significant settlement lying below.

The large number of artefacts now include a total of 21 styli, around 300 dress pins, and a huge number of ‘Sceattas’, coins from the 7th-8th centuries, as well as a small lead tablet bearing the faint but legible letters spelling ‘Cudberg’ which is a female Anglo-Saxon name.

After the interesting finds were reported, Dr Hugh Willmott and Pete Townend, a doctoral student from the University of Sheffield’s Department of Archaeology, visited the site to carry out targeted geophysical and magnetometry surveys along with 3D modelling to visualise the landscape on a large scale.

The imagery showed that the island they had discovered was much more obvious than the land today, rising out of its lower surroundings. To complete the picture the researchers raised the water level digitally to bring it back up to its early medieval height based on the topography and geophysical survey.

Dr Willmott, said: “Our findings have demonstrated that this is a site of international importance, but its discovery and initial interpretation has only been possible through engaging with a responsible local metal detectorist who reported their finds to the Portable Antiquities Scheme.”

Students from the University have subsequently opened nine evaluation trenches at the site which revealed a wealth of information about what life would have been like at the settlement.

They found a number of intriguing items including an area which seems to have been an area of industrial working, as well as very significant quantities of Middle Saxon pottery and butchered animal bone.

“It’s been an honour to be invited to work on such a unique site and demonstrate the importance of working with local people on the ground; one of the greatest strengths of the University of Sheffield is its active promotion of an understanding of our shared pasts for all concerned,” added Dr Willmott.

Source: www.Sheffield.ac.uk – “Mystery on the marsh: a newly discovered Anglo-Saxon island is one of the most important archaeological finds in decades“

Featured Image Credit: Portable Antiquities Scheme, UK

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Surprising Discovery: Laser Treatment Can Open Blood-Brain Barrier for up to Six Weeks

Neurosurgeons at Washington University in St. Louis unexpectedly found a method to open the brain’s brain-blood barrier in the process of opening the brain’s protective cover and using a laser probe to directly zap brain cancer cells in patients with a deadly form of brain cancer. The unexpected side effect of the laser’s zapping was to open the blood-brain barrier and keep it open for up to six weeks, a new development which would allow for delivery of chemotherapy or other treatments that could help combat their cancer.

In a pilot study, 14 patients with glioblastoma—the most common and aggressive type of brain cancer—underwent minimally invasive laser surgery to treat a recurrence of their tumors. Heat from the laser is known to kill brain tumor cells but, unexpectedly, the technology can also penetrate the blood-brain barrier.

“The laser treatment kept the blood-brain barrier open for four to six weeks, providing us with a therapeutic window of opportunity to deliver chemotherapy drugs to the patients,” says co-corresponding author Eric C. Leuthardt, professor of neurosurgery at Washington University in St. Louis. “This is crucial because most chemotherapy drugs can’t get past the protective barrier, greatly limiting treatment options for patients with brain tumors.

“We are closely following patients in the trial. Our early results indicate that the patients are doing much better on average, in terms of survival and clinical outcomes, than what we would expect. We are encouraged but very cautious because additional patients need to be evaluated before we can draw firm conclusions.”

Glioblastomas are one of the most difficult cancers to treat. Most patients diagnosed with this type of brain tumor survive just 15 months, according to the American Cancer Society.

The new research is part of a larger phase II clinical trial that will involve 40 patients. Twenty patients were enrolled in the pilot study, 14 of whom were found to be suitable candidates for the minimally invasive laser surgery.

The laser technology was approved by the Food and Drug Administration in 2009 as a surgical tool that can be used to treat brain tumors. But the new study marks the first time the laser has been shown to disrupt the blood-brain barrier, which shields the brain from harmful toxins but also inadvertently blocks potentially helpful drugs, such as chemotherapy.

As part of the trial, a widely used chemotherapy—doxorubicin—was given intravenously to 13 patients in the weeks following the laser surgery. Preliminary data indicate that 12 patients showed no evidence of tumor progression during the short, 10-week time frame of the study. One patient experienced tumor growth before chemotherapy was delivered; the tumor in another patient progressed after chemotherapy was administered.

The laser surgery was well-tolerated by the patients in the trial. Most patients went home one to two days afterward and none experienced severe complications. The surgery is performed while a patient lies in an MRI scanner, providing the neurosurgical team with a real-time look at the tumor. Using an incision of only 3 millimeters—about the thickness of two pennies—a neurosurgeon robotically inserts the laser to heat up and kill brain tumor cells at a temperature of about 150 degrees Fahrenheit.

“The laser kills tumor cells, which we anticipated,” Leuthard says, “but, surprisingly, while reviewing MRI scans of our patients, we noticed changes near the former tumor site that looked consistent with the breakdown of the blood-brain barrier.”

He then confirmed and further studied these imaging findings with coauthor Joshua Shimony, associate professor of radiology.

The researchers performed follow-up testing, which showed that the degree of permeability through the blood-brain barrier peaked one to two weeks after surgery but that the barrier remained open for up to six weeks.

Other successful attempts to breach the barrier have left it open for only a short time—about 24 hours—not long enough for chemotherapy to be consistently delivered—or have resulted in only modest benefits. In contrast, the new laser technology leaves the barrier open for weeks—long enough for patients to receive multiple treatments with chemotherapy. And the laser only opens the barrier near the tumor, leaving the protective cover in place in other areas, potentially limiting the harmful effects of chemotherapy drugs in other areas of the brain.

The findings suggest that other exciting approaches such as cancer immunotherapy—which harnesses cells of the immune system to seek out and destroy cancer—also may be useful for patients with glioblastomas. The researchers are planning another clinical trial that combines the laser technology with chemotherapy and immunotherapy as well as trials to test targeted cancer drugs that normally can’t breach the blood-brain barrier.

“We are hopeful this technology opens new avenues to treating these devastating brain tumors that cause great suffering for patients and their families,” Leuthardt says.

The National Cancer Institute of the National Institutes of Health, the Foundation for Barnes-Jewish Hospital,  and Washington University School of Medicine in St. Louis funded the work. The study was published in the journal PLOS ONE

Republished from Futurity.org as a derivative work under the Attribution 4.0 International license. Original article posted to Futurity by 

Featured Image Credit: NIH Image Gallery/flickr, CC BY

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#YearInSpace: The Science Behind Scott Kelly’s Mission [Infographic]

By having astronaut Scott Kelly spend a year in space, what is NASA intending to learn? Overall, they are studying what happens to the human body during extended periods of time in zero or microgravity situations, to see what we can expect for long-duration spaceflight. Kelly’s year on the International Space Station should provide researchers with many specific answers.

The infographic below from NASA provides a great summary of the studies in progress on Scott Kelly (click/tap for larger image):

Web

Source: #YearInSpace infographic and featured photo courtesy of NASA

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Mysterious chimpanzee behaviour may be evidence of ‘sacred’ rituals [Video]

Laura Kehoe, Humboldt University of Berlin

I trampled clumsily through the dense undergrowth, attempting in vain to go a full five minutes without getting snarled in the thorns that threatened my every move. It was my first field mission in the savannahs of the Republic of Guinea. The aim was to record and understand a group of wild chimpanzees who had never been studied before. These chimps are not lucky enough to enjoy the comforts of a protected area, but instead carve out their existence in the patches of forests between farms and villages.

We paused at a clearing in the bush. I let out a sigh of relief that no thorns appeared to be within reach, but why had we stopped? I made my way to the front of the group to ask the chief of the village and our legendary guide, Mamadou Alioh Bah. He told me he had found something interesting – some innocuous markings on a tree trunk. Something that most of us wouldn’t have even noticed in the complex and messy environment of a savannah had stopped him in his tracks. Some in our group of six suggested that wild pigs had made these marks, while scratching up against the tree trunk, others suggested it was teenagers messing around.

But Alioh had a hunch – and when a man that can find a single fallen chimp hair on the forest floor and can spot chimps kilometres away with his naked eye better than you can (with expensive binoculars) as a hunch, you listen to that hunch. We set up a camera trap in the hope that whatever made these marks would come back and do it again, but this time we would catch it all on film.

A world first

Camera traps automatically start recording when any movement occurs in front of them. For this reason they are an ideal tool for recording wildlife doing its own thing without any disturbance. I made notes to return to the same spot in two weeks (as that’s roughly how long the batteries last) and we moved on, back into the wilderness.

Whenever you return to a camera trap there is always a sense of excitement in the air of the mysteries that it could hold – despite the fact that most of our videos consisted of branches swaying in strong winds or wandering farmers’ cows enthusiastically licking the camera lens, there is an uncontrollable anticipation that maybe something amazing has been captured.

What we saw on this camera was exhilarating – a large male chimp approaches our mystery tree and pauses for a second. He then quickly glances around, grabs a huge rock and flings it full force at the tree trunk.

Selection of stone throwing behaviour, from carefully placing stones inside hollow trunks to full-on hurling. Video credit: Kühl et al (2016)

Nothing like this had been seen before and it gave me goose bumps. Jane Goodall first discovered wild chimps using tools in the 1960s. Chimps use twigs, leaves, sticks and some groups even use spears in order to get food. Stones have also been used by chimps to crack open nuts and cut open large fruit. Occasionally, chimps throw rocks in displays of strength to establish their position in a community.

But what we discovered during our now-published study wasn’t a random, one-off event, it was a repeated activity with no clear link to gaining food or status – it could be a ritual. We searched the area and found many more sites where trees had similar markings and in many places piles of rocks had accumulated inside hollow tree trunks – reminiscent of the piles of rocks archaeologists have uncovered in human history.

Videos poured in. Other groups working in our project began searching for trees with tell-tale markings. We found the same mysterious behaviour in small pockets of Guinea Bissau, Liberia and Côte d’Ivoire but nothing east of this, despite searching across the entire chimp range from the western coasts of Guinea all the way to Tanzania.

Sacred trees

I spent many months in the field, along with many other researchers, trying to figure out what these chimps are up to. So far we have two main theories.
The behaviour could be part of a male display, where the loud bang made when a rock hits a hollow tree adds to the impressive nature of a display. This could be especially likely in areas where there are not many trees with large roots that chimps would normally drum on with their powerful hands and feet. If some trees produce an impressive bang, this could accompany or replace feet drumming in a display and trees with particularly good acoustics could become popular spots for revisits.

On the other hand, it could be more symbolic than that – and more reminiscent of our own past. Marking pathways and territories with signposts such as piles of rocks is an important step in human history. Figuring out where chimps’ territories are in relation to rock throwing sites could give us insights into whether this is the case here.

Even more intriguing than this, maybe we found the first evidence of chimpanzees creating a kind of shrine that could indicate sacred trees. Indigenous West African people have stone collections at “sacred” trees and such man-made stone collections are commonly observed across the world and look eerily similar to what we have discovered here.

Stone throwing – in action and on site. Top line: Adult male tossing, hurling and banging a stone. Bottom line: Stones accumulated in a hollow tree; typical stone throwing site; and stones in between large roots.
Kühl et al (2016), Author provided

A vanishing world

To unravel the mysteries of our closest living relatives, we must make space for them in the wild. In the Ivory Coast alone, chimpanzee populations have decreased by more than 90% in the past 17 years.

A devastating combination of increasing human numbers, habitat destruction, poaching and infectious disease severely endangers chimpanzees. Leading scientists warn us that, if nothing changes, chimps and other great apes will have only 30 years left in the wild. In the unprotected forests of Guinea, where we first discovered this enigmatic behaviour, rapid deforestation is rendering the area close to uninhabitable for the chimps that once lived and thrived there. Allowing chimpanzees in the wild to continue spiralling towards extinction will not only be a critical loss to biodiversity, but a tragic loss to our own heritage, too.

You can support chimps with your time, by instantly becoming a citizen scientist and spying on them at www.chimpandsee.org, and with your wallet by donating to the Wild Chimpanzee Foundation. Who knows what we might find next that could forever change our understanding of our closest relatives.

The ConversationLaura Kehoe, PhD researcher in wildlife conservation and land use, Humboldt University of Berlin

This article was originally published on The Conversation. Read the original article.

Featured Photo Credit:  Mark Linfield/Walt Disney Pictures, CC BY

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