Astronomers just discovered a Morse code message in the dunes of Mars

NASA has spotted a series of strange, dark dunes on Mars that look uncannily like the dots and dashes that make up Morse code.

This isn’t the first time researchers have spotted this pattern in the sands of Mars, but thanks to its unique topography, this dune field – just south of the planet’s north pole – shows them in clearer detail than usual, allowing scientists to translate the message for the first time.

To be clear, this message is naturally formed – just like the dunes here on Earth, the dots and dashes of the dunes were carved out by the direction of the wind. There’s no spooky alien stuff at play here, promise.

As a press release from NASA explains, what makes the patterns in this dune so prominent is the fact that it’s found inside a natural circular depression, which means there’s a limited amount of sand available to be pushed around by the local winds.

The long ‘dashes’ are formed by bi-directional winds, which means wind that’s travelling at right angles to the dune.

Over time, wind coming from either direction funnels the material into a long, dark line, as you can see in the close-up image below:

NASA/JPL/University of Arizona
NASA/JPL/University of Arizona

The Martian ‘dots’ are officially known as ‘barchanoid dunes‘, and are a little more mysterious.

Geophysicists believe they’re formed when something interrupts the production of the linear dunes – but NASA still isn’t quite sure what that is, and figuring it out is part of the reason they were photographing the region.

These images were taken by the High Resolution Imaging Science Experiment (HiRISE) camera, which is on board the Mars Reconnaissance Orbiter, which has been photographing the Red Planet for the past decade.

With more observation, geophysicists are hoping that they’ll be able to figure out more about how the dunes on the surface of Mars form, and what that can tell us about the potential habitability of the planet.

But while they’re figuring that out, NASA planetary scientist Veronica Bray translated the Morse code message for Maddie Stone over at Gizmodo.

So what do the sands of Mars have to tell us? According to Bray:

NEE NED ZB 6TNN DEIBEDH SIEFI EBEEE SSIEI ESEE SEEE !!

It’s very deep stuff – and not intended as anything other than a bit of geophysial fun.

But reading the sands of Mars might one day help us better understand life on the surface of our potential future outpost, so it’s worth paying attention.

 

Source: Science Alert Gizmodo

Images of pleasure, winning have unique distracting power

It is hard to ignore positive images. Credit: © Monkey Business / Fotolia
It is hard to ignore positive images.
Credit: © Monkey Business / Fotolia

 

Images related to pleasure or winning attract attention from demanding tasks, while equally intense but negative images and those associated with losing can be fully ignored, finds a new UCL study.

51 volunteers completed attention tasks involving search for ‘target’ items. They were found to be highly distracted by emotional images, whether positive or negative, when the search was easy. However when the search was harder and demanded high focus of attention people were able to completely ignore the negative images, while the positive images continued to be highly distracting.

Positive images included graphic photographs of romantic scenes, happy faces, and neutral faces that were previously associated with winning points in a betting task. Negative images included gory photographs, angry faces and neutral faces previously associated with losing points in the betting task.

The study, published in the journal Emotion, suggests that it is easier to ignore negative images than positive ones when we are focusing on other things.

“If someone is busy, the best way to capture their attention is with something related to pleasure,” explains study author Professor Nilli Lavie (UCL Institute of Cognitive Neuroscience). “For example adverts from charities often use images of suffering to encourage donations. Our study suggests that these images could be overlooked by people who are engaged in other activities such as using their phones, reading the newspaper, or forwarding their TV recordings to resume the program they were watching. To capture the attention from other activities, charities could consider using more positive images such as happy people whose lives have been improved by donations.”

The effect was seen not only with intrinsically positive images but also neutral images that were associated with winning in a betting game. Six neutral face images were used with different odds of winning or losing points. Participants were asked to choose between different pairs to maximise points, but these did not represent real money. By the end of the 15-minute game, the patterns of ‘winning’ and ‘losing’ faces were clear; participants consistently chose faces with high odds of winning and low odds of losing.

“The attention-grabbing power of images associated with winning meaningless points is staggering,” says Professor Lavie. “While people were able to ignore graphic images of mutilated bodies during the more difficult task, neutral, expressionless faces associated with winning still distracted them. People appear to be tuned to the prospects of winning. This could suggest a new way of marketing as any neutral image such as a brand logo can be used to capture attention, if the consumer is offered to play in some betting game and the image is associated with winning.

“The results are also surprising from an evolutionary perspective, as one would expect the brain to pay most attention to negative images because they can indicate potential threats. Our findings may reflect the changing priorities of modern Western society, where we face relatively few immediate threats to our lives. In this safe space, our minds may be more focused on pleasure seeking instead of paying attention to potential harm. The power of positive images and those associated with winning may be a symptom of our competitive, hedonistic society.”


Story Source:

The above post is reprinted from materials provided by University College London. Note: Materials may be edited for content and length.


Journal Reference:

  1. Rashmi Gupta, Young-Jin Hur, Nilli Lavie. Distracted by Pleasure: Effects of Positive Versus Negative Valence on Emotional Capture Under Load.. Emotion, 2015; DOI: 10.1037/emo0000112

More than 11 moles on your arm could indicate higher risk of melanoma

Naevus (mole) count is one of the most important markers of risk for skin cancer despite only 20 to 40 per cent of melanoma arising from pre-existing moles. Credit: © phanuwatnandee / Fotolia
Naevus (mole) count is one of the most important markers of risk for skin cancer despite only 20 to 40 per cent of melanoma arising from pre-existing moles.
Credit: © phanuwatnandee / Fotolia

Researchers at King’s College London have investigated a new method that could be used by GPs to quickly determine the number of moles on the entire body by counting the number found on a smaller ‘proxy’ body area, such as an arm.

Naevus (mole) count is one of the most important markers of risk for skin cancer despite only 20 to 40 per cent of melanoma arising from pre-existing moles. The risk is thought to increase by two to four per cent per additional mole on the body, but counting the total number on the entire body can be time consuming in a primary care setting.

Previous studies on a smaller scale have attempted to identify mole count on certain body sites as a proxy to accurately estimate the number on the body as a whole and found that the arm was the most predictive.

This study, funded by the Wellcome Trust, used a much larger sample of participants to identify the most useful ‘proxy’ site for a full body mole count as well as the ‘cut off’ number of moles that can be used to predict those at the highest risk of developing skin cancer.

The researchers used data from 3594 female Caucasian twins between January 1995 and December 2003 as part of the TwinsUK study protocol. Twins underwent a skin examination including recording skin type, hair and eye colour and freckles as well as mole count on 17 body sites performed by trained nurses. This was then replicated in a wider sample of male and female participants from a UK melanoma case control study published previously.

Scientists found that the count of moles on the right arm was most predictive of the total number on the whole body. Females with more than seven moles on their right arm had nine times the risk of having more than 50 on the whole body and those with more than 11 on their right arm were more likely to have over 100 on their body in total, meaning they were at a higher risk of developing a melanoma.

These findings could help GPs to more easily identify those at the highest risk of developing a melanoma (skin cancer).

Scientists also found that the area above the right elbow was particularly predictive of the total body count of moles. The legs were also strongly associated with the total count as well as the back area in males.

Lead author, Simone Ribero of the Department of Twin Research & Genetic Epidemiology said: ‘This study follows on from previous work to identify the best proxy site for measuring the number of moles on the body as a whole. The difference here is that it has been done on a much larger scale in a healthy Caucasian population without any selection bias and subsequently replicated in a case control study from a similar healthy UK population, making the results more useful and relevant for GPs.

‘The findings could have a significant impact for primary care, allowing GPs to more accurately estimate the total number of moles in a patient extremely quickly via an easily accessible body part. This would mean that more patients at risk of melanoma can be identified and monitored.’


Story Source:

The above post is reprinted from materials provided by King’s College London. Note: Materials may be edited for content and length.


Journal Reference:

  1. S. Ribero, D. Zugna, S. Osella-Abate, D. Glass, P. Nathan, T. Spector, V. Bataille. Prediction of high naevus count in a healthy UK population to estimate melanoma risk. British Journal of Dermatology, 2015; DOI: 10.1111/bjd.14216

Artificial Skin Lets Person Feel Pressure

Human finger touches robotic finger. The transparent plastic and black device on the golden "fingertip" is the skin-like sensor developed by Stanford engineers. This sensor can detect pressure and transmit that touch sensation to a nerve cell. The goal is to create artificial skin, studded with many such miniaturized sensors, to give prosthetic appendages some of the sensory capabilities of human skin. Credit: Bao Lab
Human finger touches robotic finger. The transparent plastic and black device on the golden “fingertip” is the skin-like sensor developed by Stanford engineers. This sensor can detect pressure and transmit that touch sensation to a nerve cell. The goal is to create artificial skin, studded with many such miniaturized sensors, to give prosthetic appendages some of the sensory capabilities of human skin.
Credit: Bao Lab

Stanford engineers have created a plastic “skin” that can detect how hard it is being pressed and generate an electric signal to deliver this sensory input directly to a living brain cell.

Zhenan Bao, a professor of chemical engineering at Stanford, has spent a decade trying to develop a material that mimics skin’s ability to flex and heal, while also serving as the sensor net that sends touch, temperature and pain signals to the brain. Ultimately she wants to create a flexible electronic fabric embedded with sensors that could cover a prosthetic limb and replicate some of skin’s sensory functions.

Bao’s work, reported today in Science, takes another step toward her goal by replicating one aspect of touch, the sensory mechanism that enables us to distinguish the pressure difference between a limp handshake and a firm grip.

“This is the first time a flexible, skin-like material has been able to detect pressure and also transmit a signal to a component of the nervous system,” said Bao, who led the 17-person research team responsible for the achievement.

Benjamin Tee, a recent doctoral graduate in electrical engineering; Alex Chortos, a doctoral candidate in materials science and engineering; and Andre Berndt, a postdoctoral scholar in bioengineering, were the lead authors on the Science paper.

Digitizing touch

The heart of the technique is a two-ply plastic construct: the top layer creates a sensing mechanism and the bottom layer acts as the circuit to transport electrical signals and translate them into biochemical stimuli compatible with nerve cells. The top layer in the new work featured a sensor that can detect pressure over the same range as human skin, from a light finger tap to a firm handshake.

Five years ago, Bao’s team members first described how to use plastics and rubbers as pressure sensors by measuring the natural springiness of their molecular structures. They then increased this natural pressure sensitivity by indenting a waffle pattern into the thin plastic, which further compresses the plastic’s molecular springs.

To exploit this pressure-sensing capability electronically, the team scattered billions of carbon nanotubes through the waffled plastic. Putting pressure on the plastic squeezes the nanotubes closer together and enables them to conduct electricity.

This allowed the plastic sensor to mimic human skin, which transmits pressure information as short pulses of electricity, similar to Morse code, to the brain. Increasing pressure on the waffled nanotubes squeezes them even closer together, allowing more electricity to flow through the sensor, and those varied impulses are sent as short pulses to the sensing mechanism. Remove pressure, and the flow of pulses relaxes, indicating light touch. Remove all pressure and the pulses cease entirely.

The team then hooked this pressure-sensing mechanism to the second ply of their artificial skin, a flexible electronic circuit that could carry pulses of electricity to nerve cells.

Importing the signal

Bao’s team has been developing flexible electronics that can bend without breaking. For this project, team members worked with researchers from PARC, a Xerox company, which has a technology that uses an inkjet printer to deposit flexible circuits onto plastic. Covering a large surface is important to making artificial skin practical, and the PARC collaboration offered that prospect.

Finally the team had to prove that the electronic signal could be recognized by a biological neuron. It did this by adapting a technique developed by Karl Deisseroth, a fellow professor of bioengineering at Stanford who pioneered a field that combines genetics and optics, called optogenetics. Researchers bioengineer cells to make them sensitive to specific frequencies of light, then use light pulses to switch cells, or the processes being carried on inside them, on and off.

For this experiment the team members engineered a line of neurons to simulate a portion of the human nervous system. They translated the electronic pressure signals from the artificial skin into light pulses, which activated the neurons, proving that the artificial skin could generate a sensory output compatible with nerve cells.

Optogenetics was only used as an experimental proof of concept, Bao said, and other methods of stimulating nerves are likely to be used in real prosthetic devices. Bao’s team has already worked with Bianxiao Cui, an associate professor of chemistry at Stanford, to show that direct stimulation of neurons with electrical pulses is possible.

Bao’s team envisions developing different sensors to replicate, for instance, the ability to distinguish corduroy versus silk, or a cold glass of water from a hot cup of coffee. This will take time. There are six types of biological sensing mechanisms in the human hand, and the experiment described in Science reports success in just one of them.

But the current two-ply approach means the team can add sensations as it develops new mechanisms. And the inkjet printing fabrication process suggests how a network of sensors could be deposited over a flexible layer and folded over a prosthetic hand.

“We have a lot of work to take this from experimental to practical applications,” Bao said. “But after spending many years in this work, I now see a clear path where we can take our artificial skin.”


Story Source:

The above post is reprinted from materials provided by Stanford University. The original item was written by Tom Abate. Note: Materials may be edited for content and length.


Journal Reference:

  1. B.C.K. Tee et al. A skin-inspired organic digital mechanoreceptor. Science, 2015 DOI: 10.1126/science.aaa9306

World’s Lightest Material

the-strongest-material-in-the-world

Boeing says it’s created the lightest metal ever, a microlattice material which it describes as 99.99% air.

The microlattice is a “3D open-cellular polymer structure” and is made up of interconnecting hollow tubes, each one measuring 1000 times thinner than a human hair.

The material is 100 times lighter than styrofoam, making it the lightest and also one of the strongest materials known to science.

Sophia Yang, a research scientist at HRL laboratories who worked with Boeing on the creation of the material says that the metal is 99.99% air. She compares the material to bone, whereby the outside of the bone is rigid while the inside is mostly hollow, creating an open-cellular structure which means it’s remarkably strong as well as extremely lightweight.

The material has been made primarily for use in in aerospace engineering. Engineers intend to use the microlattice for plane interiors in places such as side-panels, overhead cabins, or walkway areas. This would drastically reduce the overall weight of the aircraft, making it more fuel-efficient and cheaper to run.

Yang also highlights the material’s ability to absorb high levels of impact. Using the “egg challenge” as an example, she explains: “You need to drop an egg from 25 stories and protect that egg… What we can do is design the microlattice to absorb the force that the egg feels. So instead of having an egg that’s wrapped in three feet of bubble wrap, now you have a much smaller package that your egg can sit in.”

The microlattice was originally unveiled in November 2011 and was named one of 10 world-changing innovations by Popular Mechanics.

Nobel Prize in Physics for 2015

Illustration of the Sudbury Neutrino Observatory. Credit: Copyright Johan Jarnestad/The Royal Swedish Academy of Sciences
Illustration of the Sudbury Neutrino Observatory.
Credit: Copyright Johan Jarnestad/The Royal Swedish Academy of Sciences

The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Physics for 2015 to Takaaki Kajita Super-Kamiokande Collaboration University of Tokyo, Kashiwa, Japan and Arthur B. McDonald Sudbury Neutrino Observatory Collaboration Queen’s University, Kingston, Canada “for the discovery of neutrino oscillations, which shows that neutrinos have mass.”

Metamorphosis in the particle world

The Nobel Prize in Physics 2015 recognises Takaaki Kajita in Japan and Arthur B. McDonald in Canada, for their key contributions to the experiments which demonstrated that neutrinos change identities. This metamorphosis requires that neutrinos have mass. The discovery has changed our understanding of the innermost workings of matter and can prove crucial to our view of the universe.

Around the turn of the millennium, Takaaki Kajita presented the discovery that neutrinos from the atmosphere switch between two identities on their way to the Super-Kamiokande detector in Japan.

Meanwhile, the research group in Canada led by Arthur B. McDonald could demonstrate that the neutrinos from the Sun were not disappearing on their way to Earth. Instead they were captured with a different identity when arriving to the Sudbury Neutrino Observatory.

A neutrino puzzle that physicists had wrestled with for decades had been resolved. Compared to theoretical calculations of the number of neutrinos, up to two thirds of the neutrinos were missing in measurements performed on Earth. Now, the two experiments discovered that the neutrinos had changed identities.

The discovery led to the far-reaching conclusion that neutrinos, which for a long time were considered massless, must have some mass, however small.

For particle physics this was a historic discovery. Its Standard Model of the innermost workings of matter had been incredibly successful, having resisted all experimental challenges for more than twenty years. However, as it requires neutrinos to be massless, the new observations had clearly showed that the Standard Model cannot be the complete theory of the fundamental constituents of the universe.

The discovery rewarded with this year’s Nobel Prize in Physics have yielded crucial insights into the all but hidden world of neutrinos. After photons, the particles of light, neutrinos are the most numerous in the entire cosmos. Earth is constantly bombarded by them.

Many neutrinos are created in reactions between cosmic radiation and Earth’s atmosphere. Others are produced in nuclear reactions inside the Sun. Thousands of billions of neutrinos are streaming through our bodies each second. Hardly anything can stop them passing; neutrinos are nature’s most elusive elementary particles.

Now the experiments continue and intense activity is underway worldwide in order to capture neutrinos and examine their properties. New discoveries about their deepest secrets are expected to change our current understanding of the history, structure and future fate of the universe.

Takaaki Kajita, Japanese citizen. Born 1959 in Higashimatsuyama, Japan. Ph.D. 1986 from University of Tokyo, Japan. Director of Institute for Cosmic Ray Research and Professor at University of Tokyo, Kashiwa, Japan. www.icrr.u-tokyo.ac.jp/about/greeting_eng.html

Arthur B. McDonald, Canadian citizen. Born 1943 in Sydney, Canada. Ph.D. 1969 from Californa Institute of Technology, Pasadena, CA, USA. Professor Emeritus at Queen’s University, Kingston, Canada. www.queensu.ca/physics/arthur-mcdonald

Prize amount: SEK 8 million, to be shared equally between the Laureates.


Story Source:

The above post is reprinted from materials provided by Nobel Foundation. Note: Materials may be edited for content and length.

Life History of a Dinosaur: Maiasaura

Research published in the journal Paleobiology is showing more about the life history of Maiasaura peeblesorum than any other known dinosaur. Credit: Courtesy Holly Woodward
Research published in the journal Paleobiology is showing more about the life history of Maiasaura peeblesorum than any other known dinosaur.
Credit: Courtesy Holly Woodward

Decades of research on Montana’s state fossil — the “good mother lizard” Maiasaura peeblesorum — has resulted in the most detailed life history of any dinosaur known and created a model to which all other dinosaurs can be compared, according to new research published recently in the journal Paleobiology.

Researchers from Oklahoma State University, Montana State University and Indiana Purdue University used fossils collected from a huge bonebed in western Montana for their study.

“This is one of the most important pieces of paleontology involving MSU in the past 20 years,” said Jack Horner, curator of the Museum of the Rockies at MSU. “This is a dramatic step forward from studying fossilized creatures as single individuals to understanding their life cycle. We are moving away from the novelty of a single instance to looking at a population of dinosaurs in the same way we look at populations of animals today.”

The study was led by Holly Woodward, who did the research as her doctoral thesis in paleontology at MSU. Woodward is now professor of anatomy at Oklahoma State University Center for Health Sciences.

The Paleobiology study examined the fossil bone microstructure, or histology, of 50 Maiasaura tibiae (shin bones). Bone histology reveals aspects of growth that cannot be obtained by simply looking at the shape of the bone, including information about growth rate, metabolism, age at death, sexual maturity, skeletal maturity and how long a species took to reach adult size.

“Histology is the key to understanding the growth dynamics of extinct animals,” Woodward said. “You can only learn so much from a bone by looking at its shape. But the entire growth history of the animal is recorded within the bone.”

A sample of 50 might not sound like much, but for dinosaur paleontologists dealing with an often sparse fossil record, the Maiasaura fossils are a treasure trove.

“No other histological study of a single dinosaur species approaches our sample size,” Woodward said.

With it, the researchers discovered a wealth of new information about how Maiasaura grew up: it had bird-level growth rates throughout most of its life, and its bone tissue most closely resembled that of modern day warm-blooded large mammals such as elk.

Major life events are recorded in the growth of the bones and the rates at which different-aged animals died.

“By studying the clues in the bone histology, and looking at patterns in the death assemblage, we found multiple pieces of evidence all supporting the same timing of sexual and skeletal maturity,” said Elizabeth Freedman Fowler, curator of paleontology at the Great Plains Dinosaur Museum in Malta and adjunct professor at MSU, who performed the mathematical analyses for the study.

Sexual maturity occurred within the third year of life, and Maiasaura reached an average adult mass of 2.3 tonnes in eight years. Life was especially hard for the very young and the old. The average mortality rate for those less than a year of age was 89.9 percent, and 44.4 percent for individuals 8 years and older.

If Maiasaura individuals could survive through their second year, they enjoyed a six-year window of peak physical and reproductive fitness, when the average mortality rate was just 12.7 percent.

“By looking within the bones, and by synthesizing what previous studies revealed, we now know more about the life history of Maiasaura than any other dinosaur and have the sample size to back up our conclusions,” Woodward said. “Our study makes Maiasaura a model organism to which other dinosaur population biology studies will be compared.”

The 50 tibiae also highlighted the extent of individual size variation within a dinosaur species. Previous dinosaur studies histologically examined a small subset of dinosaur bones and assigned ages to the entire sample based on the lengths of the few histologically aged bones.

“Our results suggest you can’t just measure the length of a dinosaur bone and assume it represents an animal of a certain age,” Woodward said. “Within our sample, there is a lot of variability in the length of the tibia in each age group. It would be like trying to assign an age to a person based on their height because you know the height and age of someone else. Histology is the only way to quantify age in dinosaurs.”

Horner, a coauthor on the research and curator of the Museum of the Rockies at MSU where the Maiasaura fossils are reposited, discovered and named Maiasaura in 1979. He made headlines by announcing the world’s first discovery of fossil dinosaur embryos and eggs. Based on the immature development of the baby dinosaur fossils found in nests, Horner hypothesized that they were helpless upon hatching and had to be cared for by parents, so naming the dinosaur Maiasaura, Latin for “good mother lizard.”

Studies that followed revealed aspects of Maiasaura biology including that they were social and nested in colonies; Maiasaura walked on two legs when young and shifted to walking on all four as they got bigger; their preferred foods included rotting wood; and that their environment was warm and semi-arid, with a long dry season prone to drought.

The tibiae included in the Paleobiology study came from a single bonebed in western Montana covering at least two square kilometers. More than 30 years of excavation and thousands of fossils later, the bonebed shows no signs of running dry. Woodward plans to lead annual summer excavations of the Maiasaura bonebed to collect more data.

“Our study kicks off The Maiasaura Life History Project, which seeks to learn as much as possible about Maiasaura and its environment 76 million years ago by continuing to collect and histologically examine fossils from the bonebed, adding statistical strength to the sample,” she said.

“We plan to examine other skeletal elements to make a histological ‘map’ of Maiasaura, seeing if the different bones in its body grew at different rates, which would allow us to study more aspects of its biology and behavior. We also want to better understand the environment in which Maiasaura lived, including the life histories of other animals in the ecosystem,” she added.

The Maiasaura Life History Project will also provide opportunities for college-aged students accompanying Woodward in her excavations to learn about the fields of ecology, biology and geology, thereby encouraging younger generations to pursue careers in science.

In addition to Woodward, Horner and Freedman Fowler, James Farlow, professor emeritus of Geology at Indiana Purdue University, contributed to the Paleobiology paper.


Story Source:

The above post is reprinted from materials provided by Montana State University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Holly N. Woodward, Elizabeth A. Freedman Fowler, James O. Farlow, John R. Horner. Maiasaura, a model organism for extinct vertebrate population biology: a large sample statistical assessment of growth dynamics and survivorship. Paleobiology, 2015; 1 DOI: 10.1017/pab.2015.19

NASA shows off Pluto’s largest moon

pluto-moon-Horizon-mission
This composite of enhanced color images of Pluto (lower right) and Charon (upper left), was taken by NASA’s New Horizons spacecraft as it passed through the Pluto system on July 14, 2015. This image highlights the striking differences between Pluto and Charon. The color and brightness of both Pluto and Charon have been processed identically to allow direct comparison of their surface properties, and to highlight the similarity between Charon’s polar red terrain and Pluto’s equatorial red terrain. Pluto and Charon are shown with approximately correct relative sizes, but their true separation is not to scale. The image combines blue, red and infrared images taken by the spacecraft’s Ralph/Multispectral Visual Imaging Camera (MVIC). Credits: NASA/JHUAPL/SwRI

 

NASA’s New Horizons spacecraft has returned the best color and the highest resolution images yet of Pluto’s largest moon, Charon – and these pictures show a surprisingly complex and violent history.

At half the diameter of Pluto, Charon is the largest satellite relative to its planet in the solar system. Many New Horizons scientists expected Charon to be a monotonous, crater-battered world; instead, they’re finding a landscape covered with mountains, canyons, landslides, surface-color variations and more.

NASA has posted some new high-res enhanced color pictures of Pluto’s largest moon, Charon (shown above in the upper left corner). Other than a reddish polar region, the images also reveal a surprisingly detailed landscape with canyons, mountains and more. A video composite of images (embedded after the break) takes us flying over a canyon NASA says is four times as long as the Grand Canyon, and twice as deep. NASA says even better pictures are on the way, although with the spacecraft 3.1 billion miles away and still going, we’ll be waiting a year to get everything.

charon-neutral-bright
Charon in Enhanced Color NASA’s New Horizons captured this high-resolution enhanced color view of Charon just before closest approach on July 14, 2015. The image combines blue, red and infrared images taken by the spacecraft’s Ralph/Multispectral Visual Imaging Camera (MVIC); the colors are processed to best highlight the variation of surface properties across Charon. Charon’s color palette is not as diverse as Pluto’s; most striking is the reddish north (top) polar region, informally named Mordor Macula. Charon is 754 miles (1,214 kilometers) across; this image resolves details as small as 1.8 miles (2.9 kilometers). Credits: NASA/JHUAPL/SwRI

 

Sleep may strengthen long-term memories in the immune system

The immune system "remembers" an encounter with a bacteria or virus by collecting fragments from the bug to create memory T cells, which last for months or years and help the body recognize a previous infection and quickly respond. Credit: © Sabphoto / Fotolia
The immune system “remembers” an encounter with a bacteria or virus by collecting fragments from the bug to create memory T cells, which last for months or years and help the body recognize a previous infection and quickly respond.
Credit: © Sabphoto / Fotolia

More than a century ago, scientists demonstrated that sleep supports the retention of memories of facts and events. Later studies have shown that slow-wave sleep, often referred to as deep sleep, is important for transforming fragile, recently formed memories into stable, long-term memories. Now, in an Opinion article published September 29 inTrends in Neurosciences, part of a special issue on Neuroimmunology, researchers propose that deep sleep may also strengthen immunological memories of previously encountered pathogens.

“While it has been known for a long time that sleep supports long-term memory formation in the psychological domain, the idea that long-term memory formation is a function of sleep effective in all organismic systems is in our view entirely new,” says senior author Jan Born of the University of Tuebingen. “We consider our approach toward a unifying concept of biological long-term memory formation, in which sleep plays a critical role, a new development in sleep research and memory research.”

The immune system “remembers” an encounter with a bacteria or virus by collecting fragments from the bug to create memory T cells, which last for months or years and help the body recognize a previous infection and quickly respond. These memory T cells appear to abstract “gist information” about the pathogens, as only T cells that store information about the tiniest fragments ever elicit a response. The selection of gist information allows memory T cells to detect new pathogens that are similar, but not identical, to previously encountered bacteria or viruses.

Studies in humans have shown that long-term increases in memory T cells are associated with deep slow-wave sleep on the nights after vaccination. Taken together, the findings support the view that slow-wave sleep contributes to the formation of long-term memories of abstract, generalized information, which leads to adaptive behavioral and immunological responses. The obvious implication is that sleep deprivation could put your body at risk.

“If we didn’t sleep, then the immune system might focus on the wrong parts of the pathogen,” Born says. “For example, many viruses can easily mutate some parts of their proteins to escape from immune responses. If too few antigen-recognizing cells [the cells that present the fragments to T cells] are available, then they might all be needed to fight off the pathogen. In addition to this, there is evidence that the hormones released during sleep benefit the crosstalk between antigen-presenting and antigen-recognizing cells, and some of these important hormones could be lacking without sleep.”

Born says that future research should examine what information is selected during sleep for storage in long-term memory, and how this selection is achieved. In the end, this research could have important clinical implications.

“In order to design effective vaccines against HIV, malaria, and tuberculosis, which are based on immunological memory, the correct memory model must be available,” Born says. “It is our hope that by comparing the concepts of neuronal and immunological memory, a model of immunological memory can be developed which integrates the available experimental data and serves as a helpful basis for vaccine development.”


Story Source:

The above post is reprinted from materials provided by Cell Press. Note: Materials may be edited for content and length.


Journal Reference:

  1. Westermann et al. System Consolidation during Sleep–A Common Principle Underlying Psychological and Immunological Memory Formation. Trends in Neurosciences, September 2015 DOI:10.1016/j.tins.2015.07.007

Liquid water flows on today’s Mars: NASA confirms evidence

Dark, narrow streaks on Martian slopes such as these at Hale Crater are inferred to be formed by seasonal flow of water on contemporary Mars. The streaks are roughly the length of a football field. Credit: NASA/JPL-Caltech/Univ. of Arizona
Dark, narrow streaks on Martian slopes such as these at Hale Crater are inferred to be formed by seasonal flow of water on contemporary Mars. The streaks are roughly the length of a football field.
Credit: NASA/JPL-Caltech/Univ. of Arizona

New findings from NASA’s Mars Reconnaissance Orbiter (MRO) provide the strongest evidence yet that liquid water flows intermittently on present-day Mars.

Using an imaging spectrometer on MRO, researchers detected signatures of hydrated minerals on slopes where mysterious streaks are seen on the Red Planet. These darkish streaks appear to ebb and flow over time. They darken and appear to flow down steep slopes during warm seasons, and then fade in cooler seasons. They appear in several locations on Mars when temperatures are above minus 10 degrees Fahrenheit (minus 23 Celsius), and disappear at colder times.

“Our quest on Mars has been to ‘follow the water,’ in our search for life in the universe, and now we have convincing science that validates what we’ve long suspected,” said John Grunsfeld, astronaut and associate administrator of NASA’s Science Mission Directorate in Washington. “This is a significant development, as it appears to confirm that water — albeit briny — is flowing today on the surface of Mars.”

These downhill flows, known as recurring slope lineae (RSL), often have been described as possibly related to liquid water. The new findings of hydrated salts on the slopes point to what that relationship may be to these dark features. The hydrated salts would lower the freezing point of a liquid brine, just as salt on roads here on Earth causes ice and snow to melt more rapidly. Scientists say it’s likely a shallow subsurface flow, with enough water wicking to the surface to explain the darkening.

“We found the hydrated salts only when the seasonal features were widest, which suggests that either the dark streaks themselves or a process that forms them is the source of the hydration. In either case, the detection of hydrated salts on these slopes means that water plays a vital role in the formation of these streaks,” said Lujendra Ojha of the Georgia Institute of Technology (Georgia Tech) in Atlanta, lead author of a report on these findings published Sept. 28 by Nature Geoscience.

Ojha first noticed these puzzling features as a University of Arizona undergraduate student in 2010, using images from the MRO’s High Resolution Imaging Science Experiment (HiRISE). HiRISE observations now have documented RSL at dozens of sites on Mars. The new study pairs HiRISE observations with mineral mapping by MRO’s Compact Reconnaissance Imaging Spectrometer for Mars (CRISM).

The spectrometer observations show signatures of hydrated salts at multiple RSL locations, but only when the dark features were relatively wide. When the researchers looked at the same locations and RSL weren’t as extensive, they detected no hydrated salt.

Ojha and his co-authors interpret the spectral signatures as caused by hydrated minerals called perchlorates. The hydrated salts most consistent with the chemical signatures are likely a mixture of magnesium perchlorate, magnesium chlorate and sodium perchlorate. Some perchlorates have been shown to keep liquids from freezing even when conditions are as cold as minus 94 degrees Fahrenheit (minus 70 Celsius). On Earth, naturally produced perchlorates are concentrated in deserts, and some types of perchlorates can be used as rocket propellant.

Perchlorates have previously been seen on Mars. NASA’s Phoenix lander and Curiosity rover both found them in the planet’s soil, and some scientists believe that the Viking missions in the 1970s measured signatures of these salts. However, this study of RSL detected perchlorates, now in hydrated form, in different areas than those explored by the landers. This also is the first time perchlorates have been identified from orbit.

MRO has been examining Mars since 2006 with its six science instruments.

“The ability of MRO to observe for multiple Mars years with a payload able to see the fine detail of these features has enabled findings such as these: first identifying the puzzling seasonal streaks and now making a big step towards explaining what they are,” said Rich Zurek, MRO project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California.

For Ojha, the new findings are more proof that the mysterious lines he first saw darkening Martian slopes five years ago are, indeed, present-day water.

“When most people talk about water on Mars, they’re usually talking about ancient water or frozen water,” he said. “Now we know there’s more to the story. This is the first spectral detection that unambiguously supports our liquid water-formation hypotheses for RSL.”

The discovery is the latest of many breakthroughs by NASA’s Mars missions.

“It took multiple spacecraft over several years to solve this mystery, and now we know there is liquid water on the surface of this cold, desert planet,” said Michael Meyer, lead scientist for NASA’s Mars Exploration Program at the agency’s headquarters in Washington. “It seems that the more we study Mars, the more we learn how life could be supported and where there are resources to support life in the future.”


Story Source:

The above post is reprinted from materials provided by NASA/Jet Propulsion Laboratory. Note: Materials may be edited for content and length.


Journal Reference:

  1. Lujendra Ojha, Mary Beth Wilhelm, Scott L. Murchie, Alfred S. McEwen, James J. Wray, Jennifer Hanley, Marion Massé & Matt Chojnacki. Spectral evidence for hydrated salts in recurring slope lineae on Mars AOP. Nature Geoscience, 2015; DOI: 10.1038/ngeo2546