Scientist 99% Sure Global Climate Change is Man-Made

Posted April 14th, 2014 at 7:16 pm (UTC+0)
9 comments

A Canadian physicist says his studies have all but completely ruled out the premise that global warming throughout the industrial era has not been merely a natural fluctuation in Earth’s climate, as some have been claiming.  The assertion was made after the scientist analyzed temperature data from as far back as 1500.

McGill University study says that there's a 99% chance that global climate change is man-made (otodo via Flickr/Creative Commons)

McGill University study says that there’s a 99% chance that global climate change is man-made (otodo via Flickr/Creative Commons)

“This study will be a blow to any remaining climate-change deniers,” said study author Shaun Lovejoy who is also a professor of physics at McGill University in Montreal. “Their two most convincing arguments – that the warming is natural in origin, and that the computer models are wrong – are either directly contradicted by this analysis, or simply do not apply to it.”

Published in a recent edition of the journal Climate Dynamics, the study, based on statistical analysis of historical data rather on complex computer models used in previous studies, provides a new perspective to the question of what is behind global warming trends.

Lovejoy said that his analysis led him to conclude “with confidence levels great than 99%, and most likely greater than 99.9%,” that global warming since 1880 has been mostly caused by man-made emissions from the burning of fossil fuels and long-term temperature variations not caused by nature.

The historical temperature data Lovejoy used for times prior to the industrial era (before 1760) were estimates that were made from “multi-proxy climate reconstructions” that had been developed by scientists in recent years.

The climate reconstructions took into consideration a variety of natural indicators such as information from tree rings, ice cores, and lake sediments.

For his data from the industrial era, Lovejoy used levels of carbon-dioxide produced by the burning of fossil fuels as a representation for all human caused climate changes, since there has been a close relationship between the world’s economic activity and the release of greenhouse gases and particulate pollution.

“This allows the new approach to implicitly include the cooling effects of particulate pollution that are still poorly quantified in computer models,” said Lovejoy.

This visualization shows a running five-year average global temperature, as compared to a baseline average global temperature from 1951-1980. (NASA GISS)

This visualization shows a running five-year average global temperature, as compared to a baseline average global temperature from 1951-1980. (NASA GISS)

Lovejoy said that his findings complement those made in a report just released by the UN’s IPCC.  He said that his study predicted, with 95% confidence, that doubling the carbon-dioxide levels in the atmosphere would increase global temperatures between 1.9 and 4.2 degrees Celsius.  The IPCC’s prediction puts the rise in temperature between 1.5 to 4.5 degrees Celsius if atmospheric carbon-dioxide levels double.

“We’ve had a fluctuation in average temperature that’s just huge since 1880 – on the order of about 0.9 degrees Celsius,” said Lovejoy. “This study shows that the odds of that being caused by natural fluctuations are less than one in a hundred and are likely to be less than one in a thousand.”

Astronomers May Have Spotted A Moon Orbiting an Extrasolar Planet

Posted April 11th, 2014 at 7:32 pm (UTC+0)
1 comment

An international team may have discovered the first exomoon orbiting a planet in a distant solar system such as what's illustrated here in this artist rendition. (NASA/JPL/Cal-Tech)

An international team may have discovered the very first exomoon orbiting a planet in a distant solar system such as what’s illustrated here in this artist rendition. (NASA/JPL/Cal-Tech)

According to NASA, more than 1,000 extrasolar planets have been confirmed in recent years. There are also thousands more potential planets beyond our solar system that are waiting to be discovered.

Now, an international group of astronomers think they may have found the first exomoon, or moon circling an exoplanet, some 1,800 light years away from Earth.  This possible planet/moon system has been dubbed MOA-2011-BLG-262.

Then again, what the astronomers saw just might be some other kind of object, since they said it’s impossible to confirm its presence.  Nonetheless the scientists call their finding a “tantalizing first step” in the search for other exomoons.

The researchers said that they made their discovery by watching a chance encounter of objects in our galaxy, something that can only be observed once.

“We won’t have a chance to observe the exomoon candidate again,” said David Bennett of the University Of Notre Dame, lead author of a new paper published in the Astrophysical Journal that outlines the discovery. “But we can expect more unexpected finds like this,” he adds.

The research was led by a scientific consortium called the Japan-New Zealand-American Microlensing Observations in Astrophysics (MOA) and the Probing Lensing Anomalies NETwork (PLANET) programs.

Using telescopes located in New Zealand and Tasmania, the research team took advantage of an astronomical phenomenon that’s known as gravitational microlensing.

For example, whenever a nearby star passes directly between Earth and a more distant star, the gravitational field of the closer star will bend and focus the light of that distant star much like a lens in an optical telescope.

...or could the discovery be that of a distant solar system, containing an exoplanet, with a mass about 18 times that of Earth, orbiting a small, dim star  such as what's illustrated here in this artist rendering (NASA/JPL-Caltech)

…or could the discovery be that of a distant solar system, containing an exoplanet having a mass about 18 times that of Earth, orbiting a small, dim star such as what’s illustrated here in this artist rendering (NASA/JPL-Caltech)

If the star closest to Earth should happen to have a planet orbiting it, the scientists said that the planet would serve as a secondary lens that would further brighten or dim the distant object’s light even more.

Through careful analysis of these brightening/dimming events, the astronomers then can determine the mass of the closer star relative to its orbiting planet.

But the astronomers point out that sometimes the object closest to earth may not be a star, but a free-floating planet with a moon circling it. In this case researchers might then be able to measure the mass of the planet relative to its orbiting moon.

While they haven’t been successful so far, astronomers have been trying to locate exomoons orbiting distant planets by using other means, such as data provided by NASA’s Kepler mission.

For the research that led to this new discovery, the nature of the objects that were closest to Earth weren’t really clear to the astronomers.

They said that the ratio of the larger object to its smaller companion is 2,000 to 1 which could mean that the two objects could either be a small, dim star that’s orbited by a planet about 18 times the mass of Earth, or the pair could be a planet that is more massive than Jupiter circled by a moon with a mass that’s less than Earth.

The research team said that they have no way of telling which of the two circumstances is correct.

“One possibility is for the lensing system to be a planet and its moon, which if true, would be a spectacular discovery of a totally new type of system,” said Wes Traub, chief scientist for NASA’s Exoplanet Exploration Program office at the Jet Propulsion Laboratory in Pasadena, California.  Traub, who wasn’t involved with the international team’s studies, also said that “The researchers’ models point to the moon solution, but if you simply look at what scenario is more likely in nature, the star solution wins.”

The astronomers said to get a true answer in determining whether or not they observed an exomoon and not another star system they would need to figure out the actual distance to the circling twosome.

The Microlensing Observations in Astrophysics (MOA) telescope dome located atop Mount John on New Zealand's South Island (Aidan/ASGW via Flickr/Creative Commons)

The Microlensing Observations in Astrophysics (MOA) telescope dome located atop Mount John on New Zealand’s South Island (Aidan/ASGW via Flickr/Creative Commons)

A pair of objects closer to Earth that are low in mass, according to the astronomers, will produce the same kind of brightening event as one that would be produced by two more massive objects located farther away. But unfortunately once the observed brightening/dimming event is over; it’s very difficult for the scientists to take the needed additional measurements to calculate the distance.  That means the actual identity of what may or may not be an exomoon will remain a mystery.

The astronomers said that perhaps sometime in the future, it just may be possible to acquire these distance measurements during lensing events by using, for example, NASA’s Spitzer and Kepler space telescopes.

If it turns out that this sighting is actually a real exomoon that’s orbiting a free-floating planet, the astronomers think that the planet may have been kicked out of a young planetary system, bringing its orbiting moon along for the ride as a travel companion.

Researchers Discover How to Speed Metabolism

Posted April 9th, 2014 at 6:42 pm (UTC+0)
7 comments

obese-mainHave you ever wondered why some people can eat and eat but never gain weight while others easily put on pounds?

Scientists say that the body’s natural ability to control weight is tied to the body’s natural rate of burning energy, something called basal cellular metabolism. One of the reasons some people can eat without gaining weight is because they have higher metabolism rates.

A research team at Beth Israel Deaconess Medical Center in Boston has discovered that altering the biochemical process that underlies a cell’s ability to burn energy could help speed a person’s metabolism possibly leading to new therapies in the worldwide fight against obesity and diabetes.

“With this discovery, we now have a means of metabolic manipulation that could help speed energy production and lead to weight loss,” said senior author Barbara Kahn from the Beth Israel Deaconess Medical Center and the Harvard Medical School.

Writing in Nature, the Boston researchers’ said reducing the amount of the protein nicotinamide N-methyltransferase (NNMT) in the fat and liver cells of mice slowed the development of obesity and diabetes in mice. At the same time, they also confirmed that obese and diabetic mice had higher levels of NNMT in their liver and fat.

Structure of the NNMT protein (EMW via Wikimedia Commons)

Structure of the NNMT protein (EMW via Wikimedia Commons)

From this key piece of information, the researchers speculated that cutting down the levels of NNMT in these cells would speed up a series of metabolic reactions involving an organic compound called polyamines.

“Polyamines are a group of biological molecules that are found throughout the body, which have fundamental functions, including regulating cell growth,” said Daniel Kraus, a co-author of the study.

The accelerated metabolic reactions would increase the amount of calories the body burns as energy while at the same time would reduce the number of calories transformed into fat.

“While diet and exercise are important in controlling weight, anti-obesity therapies could be of tremendous help, and NNMT looks to be a promising target for future therapeutic development,” said Kahn.

Excessive Gamma Rays at Milky Way’s Center Hint at Dark Matter

Posted April 4th, 2014 at 6:59 pm (UTC+0)
2 comments

Artist rendering of the Fermi Gamma-ray Space Telescope. (NASA E/PO, Sonoma State University, Aurore Simonnet)

Artist rendering of the Fermi Gamma-ray Space Telescope. (NASA)

Scientists believe high-energy gamma rays emanating from the center of our Milky Way are being produced by dark matter, the mysterious hypothetical substance believed to make up most of the physical universe.

A new study based on independent research of gamma ray light shows that the center of our galaxy is cranking out huge amounts of these light emissions.

Gamma ray emissions are thought to be normally produced by sources such as interacting binary star systems (solar systems with two stars), isolated pulsars (rotating neutron stars), remnants of supernovae (exploding stars) and particles colliding with interstellar gas.

However, scientists have deduced other sources must be contributing to the massive output.

The researchers involved with the study, including scientists from NASA and Stanford and Harvard universities, believe this excess gamma radiation could be produced by dark matter.

A map of gamma rays detected in the galactic center by the Fermi Space Telescope. Red indicates the greatest number emissions. Prominent pulsars are labeled (left). Removing all known gamma-ray sources (right) reveals excess emission that may arise from dark matter annihilations. (T. Linden, Univ. of Chicago)

A map of gamma rays detected in the galactic center by the Fermi Space Telescope. Red indicates the greatest number emissions. Prominent pulsars are labeled (left). Removing all known gamma-ray sources (right) reveals excess emission that may arise from dark matter annihilations. (T. Linden, Univ. of Chicago)

“The new maps allow us to analyze the excess and test whether more conventional explanations, such as the presence of undiscovered pulsars or cosmic-ray collisions on gas clouds, can account for it,” said Dan Hooper, an astrophysicist at Fermilab in Batavia, Ill., and a lead author of the study. “The signal we find cannot be explained by currently proposed alternatives and is in close agreement with the predictions of very simple dark matter models.”

The scientists subtracted already known gamma ray sources from the amount of the high energy radiation coming out of the galactic center and found a remaining patch of leftover emissions (see photo right).

“This study is an example of innovative techniques applied to Fermi data by the science community,” said Peter Michelson, a Stanford University physics professor and the principal investigator for the Large Area Telescope (LAT), the principal scientific instrument on the Fermi Gamma Ray Space Telescope spacecraft. “The Fermi LAT Collaboration continues to examine the extraordinarily complex central region of the galaxy, but until this study is complete we can neither confirm nor refute this interesting analysis.”

While dark matter provides a convenient explanation for the gamma ray excess, the researchers point out it will take further investigation to confirm the role dark matter plays in the production of the excess gamma radiation. They also note continued research could reveal other possible alternative sources of the gamma rays that do not require dark matter.

This animation zooms into an image of the Milky Way, shown in visible light, and superimposes a gamma-ray map of the galactic center from NASA’s Fermi. Raw data transitions to a view with all known sources removed, revealing a gamma-ray excess hinting at the presence of dark matter. (NASA Goddard; A. Mellinger, CMU; T. Linden, Univ. of Chicago)

Flies Credited with Giving Zebras Their Stripes

Posted April 2nd, 2014 at 6:36 pm (UTC+0)
12 comments

A pair of zebras in Tanzania's Ruaha National Park (Paul Shaffner via Wikimedia Commons)

A pair of zebras in Tanzania’s Ruaha National Park. (Paul Shaffner via Wikimedia Commons)

Scientists say flies played a key role in the centuries-old mystery of how zebras came to have their distinguishing coat of black and white stripes.

Like humans and other primates whose fingerprints are unique to each individual, every zebra has its own distinctive set of striped markings.

The research team from the University of California, Davis tested five popular theories regarding zebras and their stripes and was able to reject all but one hypothesis.

Writing in Nature Communications, the researchers assert the zebra’s striped coating is the result of an evolutionary response to annoying and possibly harmful biting flies, such as horse flies and tsetse flies.

“I was amazed by our results,” said lead author Tim Caro, a University of California, Davis professor of wildlife biology. “Again and again, there was greater striping on areas of the body in those parts of the world where there was more annoyance from biting flies.“

Zebras developed their stripes flies like the tsetse fly (left) and the horse fly (right) from biting them (Alan R. Walker (left) Dennis Ray (right) via Wikimedia Commons)

Zebras developed their stripes to keep flies like the tsetse fly (left) and the horse fly (right) from biting them. (Alan R. Walker (left) Dennis Ray (right) via Wikimedia Commons)

Studies, including those conducted previously by the team, revealed that these fly species seemed to be most attracted to animals with dark solid coloring, while avoiding black-and-white striped surfaces. The researchers found these blood sucking flies were more attracted to solid dark surfaces that reflected light waves which were constant and oriented in the same direction. Scientists surmised the light waves reflected from dark surfaces were similar to those reflected from pools of water where the flies are known to lay their eggs. By contrast, striped surfaces might be less inviting to flies because they emit multiple light patterns.

The research team said evolution provided zebras with their stripes, while other hooved animals in the same vicinity remained stripe free, because the zebra’s hair is much shorter than the mouth part length of biting flies. This led the research team to think that zebras might especially vulnerable to the biting flies.

An up close look at a zebra's unique stripe covered coat. (William Warby via Flickr/Creative Commons)

An close-up look at a zebra’s unique stripe covered coat. (William Warby via Flickr/Creative Commons)

“No one knew why zebras have such striking coloration,” Caro said. “But solving evolutionary conundrums increases our knowledge of the natural world and may spark greater commitment to conserving it.”

While the team solved one mystery others remain to be explained, such as what prevents these blood sucking flies from seeing striped surfaces as potential prey, and why are zebras, in particular, so vulnerable to these annoying insects.

Other theories as to why zebras have stripes include that the stripes protect them from attack by hiding them in the grass or by visually confusing their predators; that they serve as a form of heat management; or provide the animals with a social function.

Study Links Obesity to How Well We Digest Carbs

Posted March 31st, 2014 at 6:14 pm (UTC+0)
3 comments

Starchy foods like breads, pasta and rice are rich in refined carbohydrates (Wikimedia Commons)

Starchy foods like breads, pasta and rice are rich in refined carbohydrates. (Wikimedia Commons)

Obesity may be genetically linked to how our bodies digest carbohydrates, according to a new study from Imperial College London.

The body uses carbohydrates from the food we eat to produce glucose, which is used to fuel bodily functions. The human body can either use this glucose right away or store it in the liver and muscles for when it’s needed.

In their study, published Nature Genetics, researchers examined the connection between body weight and a gene called AMY1,which produces an enzyme found in our saliva called salivary amylase. The enzyme goes to work as soon as we take our first bite; it’s one of the first steps the body takes to digest starchy food.

Usually our DNA contains two copies of this gene, but researchers have found that various regions throughout our DNA can carry any number of the AMY1 gene and that the quantity of this gene can also vary between different people. The researchers believe that the higher numbers of AMY1 found in humans today is an evolutionary response to the change in diets toward increased starch.

Working with colleagues at institutions in other parts of the world, the British researchers looked into the number of AMY1 copies present in the DNA of people from the UK, France, Sweden and Singapore.

The UK scientists began their research project by first analyzing genetic data from 481 members of a Swedish family. The family participants were selected by sibling pairs, where one was obese and the other was not.

The researchers used this data to develop a short list of genes whose differences in numbers within an individual’s DNA influenced that person’s body mass index (BMI). In analyzing this list, the scientists found the gene coding for the AMY1 gene was the one with the greatest influence on body weight.

Artist rendering of the structure of AMY1A (EMW via Wikimedia Commons)

Artist rendering of the structure of AMY1A (EMW via Wikimedia Commons)

With this finding in hand, they went on study about 5,000 more test subjects from France and the UK and looked into the association between the number of times the AMY1 gene was repeated on chromosome 1 in each of these people and their risk of obesity.

After checking for the amount of AMY1 copies contained in their test subject’s DNA, they noticed that those with a low number of the salivary enzyme producing gene had a greater chance of becoming obese.

The researchers then expanded their study to include approximately 700 people from Singapore, both obese and normal weight, and came up with the same results found with the European subjects.

The UK scientists found that people with fewer than four copies of the AMY1 had a nearly eight times higher chance of being obese that those who had nine or more copies within their DNA.

With every extra copy of the AMY1 gene a person had, the researchers estimated that there was approximately a 20 per cent decrease in the chances of that person becoming obese.

“I think this is an important discovery because it suggests that how we digest starch and how the end products from the digestion of complex carbohydrates behave in the gut could be important factors in the risk of obesity,” said Philippe Froguel of Imperial College London, one of the study’s lead authors. “Future research is needed to understand whether or not altering the digestion of starchy food might improve someone’s ability to lose weight, or prevent a person from becoming obese.”

obese-mainThe team is also interested in whether there’s a link between this genetic variation and people’s risk of other metabolic disorders such as diabetes.

Another study author, Mario Falchi, also from Imperial College London, said that while their study examined how our bodies physically digest carbohydrates, earlier genetic studies related to obesity focused on identifying differences in genes that act in the brain which control our appetites.

He said that the previous studies, combined with their new research, will allow scientists to find better ways of attacking obesity.

Science Images of the Month

Posted March 28th, 2014 at 8:25 pm (UTC+0)
Comments are closed

NASA/JPL's new Airborne Snow Observatory flys over the Tuolumne River Basin of California’s Sierra Nevada mountain range as it measures the snowpack’s depth and water content with precision amid California’s drought. (AP Photo/Haven Daley)

NASA’s new Airborne Snow Observatory flies over California’s Sierra Nevada mountain range as it measures the snowpack’s depth and water content amid California’s drought, March 23, 2014. (AP)

A very small version of the 20-gigapixel mosaic depicting part of the Milky Way.  The mosaic image was constructed from more than 2 million infrared snapshots taken over the past 10 years by NASA's Spitzer Space Telescope. (NASA)

On March 18, 2014,  NASA officials in Pasadena, Calif unveiled GLIMPSE360, a new website that offers a tour of the Milky Way with a new zoomable, 360-degree mosaic. The mosaic image was constructed from more than 2 million infrared snapshots taken over the past 10 years by NASA’s Spitzer Space Telescope. (NASA)

Engineers working inside the world's largest clean room located at NASA's Goddard Space Flight Center this week installed the Near Infrared Camera (NIRCam), into James Webb Space Telescope.  The NIRCam is considered to be an essential part of the new space telescope that's currently under construction. NASA is looking to launch the state of the art space telescope in 2018. (NASA/Chris Gunn)

Engineers work inside the world’s largest clean room at NASA’s Goddard Space Flight Center, on March 20, 2014, installing the Near Infrared Camera (NIRCam) into the James Webb Space Telescope, which is under construction and slated to launch in 2018. (NASA)

Researchers at the Georgia Institute of Technology recentlhy used this device that simulated blood flowing through narrowed coronary arteries to assess effects of anti-clotting drugs. (Rob Felt/GA Tech)

This past week researchers at the Georgia Institute of Technology said that they found that aspirin can prevent dangerous blood clots in some at-risk patients, it may not be effective in all patients with narrowed arteries. The researchers used this device that simulated blood flowing through narrowed coronary arteries to assess effects of anti-clotting drugs. (Rob Felt/GA Tech)

Images from NASA's Hubble Space telescope and Chandra X-Ray Observatory were assembled into a mosaic of the galaxy ESO 137-001 (top right) hurtling through massive galaxy cluster Abell 3627 which is some 220 million light years away. (NASA, ESA, CXC)

This mosaic photo, released March 4, 2014, shows the galaxy ESO 137-001 (top right) hurtling through massive galaxy cluster Abell 3627.  The mosaic was made from images taken by NASA’s Hubble Space telescope and Chandra X-Ray Observatory. This region of space is some 220 million light years away from Earth. (NASA)

Artists' reconstruction of Tamisiocaris borealis, an ancient marine animal that lived 520 million years ago during the Early Cambrian period. Research led by the University of Bristol UK that studied fossils of this creature found that they used some rather odd facial appendages to filter their food from the ocean. (Rob Nicholls, Palaeocreations)

Artists’ reconstruction of Tamisiocaris borealis, an ancient marine animal that lived 520 million years ago during the Early Cambrian period. On March 26, 2014, researchers from the University of Bristol in the UK, unveiled a new study that found that this creature used some rather odd facial appendages to filter their food from the ocean. (Rob Nicholls, Palaeocreations)

The Expedition 39 Soyuz rocket takes off from the Baikonur Cosmodrome Wednesday, March 26, 2014, in Baikonur, Kazakhstan. (AP/NASA)

The Expedition 39 Soyuz rocket takes off from the Baikonur Cosmodrome on March 26, 2014, in Baikonur, Kazakhstan. (AP/NASA)

Artists's concept of the ATHENA desktop human 'body' that's being built at the Los Alamos National Laboratory.  Scientists there say this device, that combines heart, liver, kidney and lung features, could reduce need for animal drug tests in checking a drug's toxicity. (Los Alamos National Laboratory)

Artist’s concept of the ATHENA desktop human body being built at the Los Alamos National Laboratory. The device, which combines heart, liver, kidney and lung features, could reduce need for animal drug tests when assessing a drug’s toxicity. (Los Alamos National Laboratory)

 

Move Over Saturn, Scientists Find Rings Around Miniature Planet

Posted March 26th, 2014 at 6:01 pm (UTC+0)
1 comment

Artist impression of the two rings encircling the mini-planet Chariklo (Lucie Maquet)

Artist impression of the two rings encircling the minor planet Chariklo (Lucie Maquet)

Whenever you think of a planet with rings around it, Saturn probably comes to mind first. Jupiter, Uranus and Neptune – the four outer giant planets - also have rings, but they’re not as bright, wide and colorful as Saturn’s.

However, scientists in Chile now say they’ve discovered the first miniature planet with two rings circling it. The team of astronomers, based at various South American observatories, including the European Space Organization’s La Silla Observatory, says the rings are made of ice and pebbles.

It is the first time astronomers have found rings around any of the smaller celestial objects orbiting the Sun.

The mini-planet is actually a giant asteroid called Chariklo, a celestial body known as a centaur or minor planet. It is believed to have originated in the Kuiper belt, a vast collection of icy celestial objects, but at some point was thrown out. Chariklo, which is about 250 kilometers in diameter, is currently located about 2 billion kilometers away from Earth, between Saturn and Uranus.

The astronomers were able to detect Chariklo’s rings as it passed in front of a star identified as UCAC4 248-108672 on June 3, 2013.

The star seemed to disappear for a few moments as Chariklo blocked its light by passing in front of it, an event known as occultation. The astronomers also noted two very short dips in the star’s apparent brightness: First, a few seconds before, and then again a few seconds after, the star’s light was blocked by the centaur.

These observations led the astronomers to believe that something surrounding the small celestial object was blocking the light.

Another artist impression that shows how the rings might look from close to the surface of Chariklo. (ESO/L. Calçada/Nick Risinger-skysurvey.org)

Artist impression shows how Chariklo’s rings might look from the surface of the minor planet. (ESO/L. Calçada/Nick Risinger-skysurvey.org)

After comparing notes from different observational sites, the team was able to recreate not only the shape and size of Chariklo itself, but also the shape, width, orientation and other properties of its rings.

“We weren’t looking for a ring and didn’t think small bodies like Chariklo had them at all, so the discovery and the amazing amount of detail we saw in the system came as a complete surprise,” said Felipe Braga-Ribas of Brazil’s National Observatory in Rio de Janeiro, who planned the observation campaign and is lead author on the paper published in Nature.

The two narrow rings surrounding Chariklo are about 7 kilometers wide for one ring and 3 kilometers wide for the other. The two rings are separated a gap of about nine kilometers.

“For me, it was quite amazing to realize that we were able not only to detect a ring system, but also pinpoint that it consists of two clearly distinct rings,” said team member Uffe Gråe Jørgensen of the  University of Copenhagen. “I try to imagine how it would be to stand on the surface of this icy object, small enough that a fast sports car could reach escape velocity and drive off into space, and stare up at a 20 kilometer wide ring system 1,000 times closer than the Moon.”

Scientists at the Niels Bohr Institute at the University of Copenhagen developed a special high resolution-camera for the 1.54 meter Danish telescope at La Silla that, according to Jørgensen, played a key role in making the discovery.

Scientists don’t know for sure how the two rings surrounding Chariklo formed but Jørgensen has a theory.

Special hi-res camera system that was specially developed at the Niels Bohr Institute is now sitting on the Danish telescope at the La Silla Observatory in Chile. The camera played a significant role in making the discovery of the rings surrounding Chariklo. (Jesper Skottfelt, Niels Bohr Institute)

Special hi-res camera system that was specially developed at the Niels Bohr Institute is now sitting on the Danish telescope at the La Silla Observatory in Chile. (Jesper Skottfelt, Niels Bohr Institute)

“What we are witnessing is perhaps the unveiling of an object that is in the middle of the same stage of development as the Earth and the Moon 4.5 billion years ago, when there was a giant collision between Earth and another planet,” he said. “In the collision, material hurled out in all directions, forming a circular disc around the Earth, which gradually condensed and formed the Moon. Similarly, we believe that another celestial body crashed into Chariklo and a good deal of material was cast out and formed rings. If the two discs around Chariklo gather and form a moon, it will be approximately 2 kilometers in diameter.”

The project leaders have given the two rings temporary nicknames, Oiapoque and Chuí, after Brazilian rivers.

Researchers Test Real ‘Thinking Cap’

Posted March 24th, 2014 at 7:22 pm (UTC+0)
Comments are closed

Robert Reinhart applies the electrical stimulus to subject Laura McClenahan. (John Russell/Vanderbilt University)

Robert Reinhart applies the electrical stimulus to subject Laura McClenahan. (John Russell/Vanderbilt University)

Teachers often urge their students to  put on their “thinking caps” as a way of encouraging serious thought. However, a real thinking cap could someday become a reality. New research shows it’s possible to control the ability to learn by applying mild electrical current to the brain.

Writing in the Journal of Neuroscience, the Vanderbilt University researchers say the results of their studies could eventually provide help to those wanting to improve their learning abilities and could also be used to treat various conditions such as schizophrenia and Attention Deficit Hyperactivity Disorder (ADHD).

The researchers made their findings after being intrigued by past studies that show a spike in negative voltage within the medial-frontal cortex of the brain milliseconds after a person makes an error. This area of the brain is thought to be responsible for the “oops” reaction whenever an error is made.

The previous research did not explain why this brain reaction occurs, so the Vanderbilt duo decided find out by testing several theories.  They also wanted see if that activity in the medial-frontal cortex would influence the ability to learn since the brain allows us to learn from our mistakes.

“And that’s what we set out to test: What is the actual function of these brainwaves?” said researcher Robert Reinhart, a Ph.D. candidate. “We wanted to reach into your brain and causally control your inner critic.”

The theories Reinhart and research partner Geoffrey Woodman, an assistant professor of psychology, wanted to test was to see if it was possible to control the brain’s electrophysiological – electrical properties of a living cell – response to mistakes, and if the effect could be purposely controlled either up or down depending on which direction an electrical current is applied to it. They also wanted to see how long the effect of the electrical application would last and whether the same methods could be used to control other tasks.

To conduct their tests, Reinhart and Woodman took an elastic cap with two electrodes fastened to saline-soaked sponges; the sponges were applied to the cheek and  crown of the head of the research subjects.

The researchers then applied 20 minutes of very mild transcranial – across or through the skull – direct current stimulation to each of their subjects.

(Quinn Dombrowski via Flickr/Creative Commons)

(Quinn Dombrowski via Flickr/Creative Commons)

During this process, the current traveled from one electrode, called the anodal electrode, which was attached to the crown of the head, through the skin, muscle, bones and brain, and out through the other electrode, or cathodal electrode, attached to the cheek in order to complete the circuit.

“It’s one of the safest ways to noninvasively stimulate the brain,” Reinhart said. “The current is so gentle that subjects reported only a few seconds of tingling or itching at the beginning of each stimulation session.”

The researchers conducted three of these transcranial stimulation sessions. Their subjects were randomly given either an anodal – current sent from the crown of the head to the cheek, cathodal – current sent from cheek electrode to crown – or a fake jolt that merely produced a tingling effect without actually affecting the brain.

After undergoing 20 minutes of trancranial stimulation, the test subjects were given a learning task that involved determining, through trial and error, which buttons on a game controller matched specific colors displayed on a monitor. The researchers would occasionally complicate the tests by showing the subjects a signal that told them not to respond. The subjects had less than a second to respond to each signal correctly, which made it easier for them to make mistakes, providing a number of opportunities for the medial-frontal cortex to fire.

The researchers measured the electrical brain activity of each subject as they made their way through the exercises. The measurements provided the researchers with a way to monitor how the brain changed at the very moment the subjects made an error and how the electrical stimulation influenced changes in brain activity.

Shortly after the researchers sent the current from the crown of the subject’s head to their cheek – an anodal current – they noticed that the spike in negative voltage was almost twice as large on average as without stimulation.

As a result of the anodal stimulation, the researchers found the subjects made fewer mistakes and that they actually learned from their errors faster than they did after a phony jolt was applied.

Portable EEG machine (John Koetsier via Creative Commons/Flickr)

Portable EEG machine (John Koetsier via Creative Commons/Flickr)

When they sent the current in the opposite direction, from the cheek to the crown of the head – cathodal current – the Vanderbilt duo saw the opposite of the anodal result take place.  They noticed that the spike in negative voltage was actually much smaller; the subjects wound up making many more errors and they took longer to learn each task.

The researchers noted that while the positive or negative effects generated by each of the stimulation patterns weren’t detected by the test subjects themselves, the results of each test displayed very clearly on their monitoring devices.

“This success rate is far better than that observed in studies of pharmaceuticals or other types of psychological therapy,” said Woodman.

The researchers said that their tests also revealed that the sessions of electrical stimulation did transfer to other tasks and the effects lasted for about five hours.

Earth’s Natural Climate Control Keeps Planet Livable

Posted March 19th, 2014 at 11:03 pm (UTC+0)
1 comment

(Atmospheric Infrared Sounder via Wikimedia Commons)

(Atmospheric Infrared Sounder Wikimedia Commons)

A new hypothesis explains why Earth has remained habitable despite natural events that have robbed other planets in our solar system of their ability to host and sustain life.

As the character Goldilocks exclaimed in the classic fairytale, The Story of the Three Bears, Earth is the one planet in our solar system that’s “just right” to maintain the ideal conditions for life to exist, unlike, for example, Mars that’s “too cold” or Venus that’s “too hot.”

Researchers gathered documented evidence to support their new theory said that one reason Earth has stayed livable is because of the various geologic cycles it’s gone through over millions of years and continues to undergo today.

The scientists, from the University of Southern California in Los Angeles and Nanjing University in China, write in the journal Nature that they have found that the geologic cycles — which alternately release and then absorb atmospheric carbon dioxide — act as a form of climate control to keep Earth in balance.

1912 Illustration of Goldilocks running from the 3 bears - from the fairytale (Wikimedia Commons)

1912 Illustration of Goldilocks running from the three bears – from the fairytale (Wikimedia Commons)

Scientists already understood that new or “fresh” rock pushed up through the Earth’s surface when the world’s mountains formed, acting as sort of a sponge, soaking up carbon dioxide, a common greenhouse gas.

However, researchers also noted that if this process of absorbing greenhouse gas continued unabated without any kind of cut-off switch, levels of atmospheric CO2 levels would have been drained to a level that would have caused the Earth to fall into an endless winter a few million years after major mountain ranges such as the Himalayas began to form. Fortunately for all of us, this unrestrained absorption of atmospheric carbon dioxide did not take place.

Researchers involved with this study said that the same fresh rock that served as a sponge to soak up CO2 also produced carbon through a chemical weathering process which replenishes the atmospheric carbon dioxide at a similar rate.

The Himalayas as seen from the International Space Station (NASA)

The Himalayas as seen from the International Space Station (NASA)

“Our presence on Earth is dependent upon this carbon cycle. This is why life is able to survive,” said the Mark Torres, from USC, lead author of the study.

The researchers studied samples of rock taken from the Andes Mountains in Peru.  They noticed an abundance of pyrite or “fool’s gold” among the samples and noted that the chemical breakdown of pyrite produces acids that in turn release CO2 from surrounding minerals.

They realized the fresh rock’s weathering processes, aided by the acid release by surrounding pyrite, produced more carbon than was estimated previously. This led researchers to consider the worldwide consequences of CO2 release brought on by the formation of major mountain ranges about 60 million years ago during the Cenozoic period.

To further explore the link between releases of atmospheric CO2 from weathering rock the researchers looked at marine records of long-term carbon cycles.

Researcher Josh West treks through a valley in Peru in search of evidence of chemical weathering of rocks as they erode. (Photo/courtesy of Mark Torres

Researcher Josh West treks through a valley in Peru in search of evidence of chemical weathering of rocks as they erode. (Mark Torres)

With this information, they were then able to reconstruct the balance between the discharge of CO2 into the atmosphere and absorption of the greenhouse gas from the production of fresh rocks brought on by the uplift of the Earth’s surface during the formation of large mountain ranges.

They found that weathering rock might have played a rather significant, but until now, unseen role in regulating the amount of carbon dioxide released into the atmosphere over the last 60 or so million years.

Lately, a lot of attention has focused on the harm caused to Earth’s climate by increased human-generated atmospheric carbon dioxide, but  the researchers who conducted the US/China study say Earth’s natural geologic system has kept things in balance for millions of years.

About Science World

Science World

Science World is VOA’s on-air and online magazine covering science, health, technology and the environment.

Hosted by Rick Pantaleo, Science World‘s informative, entertaining and easy-to-understand presentation offers the latest news, features and one-on-one interviews with researchers, scientists, innovators and other news makers.

Listen to a Recent Program

Listen Sidebar

Broadcast Schedule

Broadcast Schedule

Science World begins after the newscast on Friday at 2200, Saturday at 0300, 1100 and 1900 and Sunday at 0100, 0400, 0900, 1100 and 1200.

Science World may also be heard on some VOA affiliates after the news on Saturday at 0900 and 1100. (All times UTC).

Contact Us

E-Mail
science@voanews.com

Postal Mail
Science World
Voice of America
330 Independence Ave., SW
Washington, DC 20237
USA