An enzyme that facilitates the breakdown of specific amino acids makes brain cancers particularly aggressive. Scientists from the German Cancer Research Center (DKFZ) discovered this in an attempt to find new targets for therapies against this dangerous disease. They have reported their findings in the journal “Nature Medicine”.
To fuel phases of fast and aggressive growth, tumors need higher-than-normal amounts of energy and the molecular building blocks needed to build new cellular components. Cancer cells therefore consume a lot of sugar (glucose A number of tumors are also able to catabolize the amino acid glutamine, an important building block of proteins. A key enzyme in amino acid decomposition is isocitrate dehydrogenase (IDH). Several years ago, scientists discovered mutations in the gene coding for IDH in numerous types of brain cancer. Very malignant brain tumors called primary glioblastomas carry an intact IDH gene, whereas those that grow more slowly usually have a defective form.
“The study of the IDH gene currently is one of the most important diagnostic criteria for differentiating glioblastomas from other brain cancers that grow more slowly,” says Dr. Bernhard Radlwimmer from the German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ). “We wanted to find out what spurs the aggressive growth of glioblastomas.” In collaboration with scientists from other institutes including Heidelberg University Hospital, Dr. Martje Tönjes and Dr. Sebastian Barbus from Radlwimmer’s team compared gene activity profiles from several hundred brain tumors. They aimed to find out whether either altered or intact IDH show further, specific genetic characteristics that might help explain the aggressiveness of the disease.
The researchers found a significant difference between the two groups in the highly increased activity of the gene for the BCAT1 enzyme, which in normal brain tissue is responsible for breaking down so-called branched-chain amino acids. However, Radlwimmer’s team discovered, only those tumor cells whose IDH gene is not mutated produce BCAT1. “This is not surprising, because as IDH breaks down amino acids, it produces ketoglutarate – a molecule which BCAT1 needs. This explains why BCAT1 is produced only in tumor cells carrying intact IDH. The two enzymes seem to form a kind of functional unit in amino acid catabolism,” says Bernhard Radlwimmer.
Glioblastomas are particularly dreaded because they aggressively invade the healthy brain tissue that surrounds them. When the researchers used a pharmacological substance to block BCAT1’s effects, the tumor cells lost their invasive capacity. In addition, the cells released less of the glutamate neurotransmitter. High glutamate release is responsible for severe neurological symptoms such as epileptic seizures, which are frequently associated with the disease. When transferred to mice, glioblastoma cells in which the BCAT1 gene had been blocked no longer grew into tumors.
“Altogether, we can see that overexpression of BCAT1 contributes to the aggressiveness of glioblastoma cells,” Radlwimmer says. The study suggests that the two enzymes, BCAT1 and IDH, cooperate in the decomposition of branched-chain amino acids. These protein building blocks appear to act as a “food source” that increases the cancer cells’ aggressiveness. Branched-chain amino acids also play a significant role in metabolic diseases such as diabetes. This is the first time that scientists have been able to show the role of these amino acids in the growth of malignant tumors.
“The good news,” sums up Radlwimmer, “is that we have found another target for therapies in BCAT1. In collaboration with Bayer Healthcare, we have already started searching for agents that might be specifically directed against this enzyme.” The researchers also plan to investigate whether BCAT1 expression may serve as an additional marker to diagnose the malignancy of brain cancer.
The Cassini spacecraft was a project launched by NASA, the European Space Agency and the Italian Space Agency that has yielded large amounts of useful data and many beautiful pictures. This one in particular shows the C ring on the right, and the B on the left. The red hues indicate dirty particles and blue the cleaner ice. The rings of Saturn are labelled from the inside out with rings, D, C, B, and A, followed by F, G, and E. In order to image the rings in such quality the Cassini spacecraft used its Ultraviolet Imaging Spectrograph in resolution some 100 times that of the Voyager 2 spacecraft.
Around the world but notably in the U.S., possession of many psychedelic substances such as cannabis, MDMA and a long list of others have been tightly controlled since the 1960s. But now, the issue of the harm some of these drugs is being called into the spotlight as emerging research continuously shows that some are less harmful than other easily obtainable and legal drugs as alcohol. In light of this, it would appear the regulations on these drugs are unfair and get in the way of science around the world. Many researchers would love to work on the fascinating effects and mechanisms of various psychedelics on the brain as a gateway to treatments for mental illnesses but have to abandon their research in face of large fees for obtaining a permit, regular police checks, and usually very large costs per dosage. There are calls for the neuroscientific community around the world to rally their governments to create more rational laws that are based on the latest scientific evidence and allow use of psychedelics in research. So, what do you think? Should the laws be reformed in the name of science and rationality? What changes would you propose?
The technology available for data storage on DVDs has been increasing rapidly as the years progress, with double and triple layering for larger and larger sizes, but this new development blows everything else out of the water. Instead of the two or threefold increase in storage capacity we see in those technologies, this new development has seen an increase from 4.7GB on a DVD to 1,000TB or one petabyte.
Traditional storage is achieved through the ‘burning’ of strings of bits, (0s and 1s) onto the disk using a laser, where the size of the bit is limited to half the wavelength used to burn it, which in the case of most hard drives is around 500 nanometres. In the study the researchers used two different lasers to create a smaller dot by using one laser to write the data, and another to surround the first laser in a torus of an anti-recording function thus cancelling out the writing function where they overlap. This allowed the researchers to focus the beam into a much smaller area thus allowing them to write more bits in smaller areas and increase the storage capacity; the new focal spot is around 9 nanometres.
The technique is very cost effective and portable as only conventional lasers are used but in a slightly different way. It is hoped this technology will allow for extremely large data storage with a long lifespan and low energy consumption in such places as big data centres.
More than a year of Spirit’s examination of the feature in Gusev Crater known as Home Plate is chronicled in this animation of nine images from the HiRISE camera on Mars Reconnaissance Orbiter. The images cover an area approximately 100 meters square. The geometry of Home Plate appears to shift from image to image because the orbiter often had to turn to one side or the other of its orbital track across Mars in order to view Spirit, so usually saw the raised topography of Home Plate from a point that was not directly over Spirit’s head. However, some of the apparent shifts in features are also real shifts in the distribution of dust around Home Plate with shifting winds and seasons. The global dust storm of 2007 almost completely blocks the view of Spirit at one point during the animation.
Via Flickr: Caption: This image from June 20, 2013, at 11:15 p.m. EDT shows the bright light of a solar flare on the left side of the sun and an eruption of solar material shooting through the sun’s atmosphere, called a prominence eruption. Shortly thereafter, this same region of the sun sent a coronal mass ejection out into space.
On June 20, 2013, at 11:24 p.m., the sun erupted with an Earth-directed coronal mass ejection or CME, a solar phenomenon that can send billions of tons of particles into space that can reach Earth one to three days later. These particles cannot travel through the atmosphere to harm humans on Earth, but they can affect electronic systems in satellites and on the ground.
Experimental NASA research models, based on observations from NASA’s Solar Terrestrial Relations Observatory and ESA/NASA’s Solar and Heliospheric Observatory show that the CME left the sun at speeds of around 1350 miles per second, which is a fast speed for CMEs.
Earth-directed CMEs can cause a space weather phenomenon called a geomagnetic storm, which occurs when they funnel energy into Earth’s magnetic envelope, the magnetosphere, for an extended period of time. The CME’s magnetic fields peel back the outermost layers of Earth’s fields changing their very shape. Magnetic storms can degrade communication signals and cause unexpected electrical surges in power grids. They also can cause aurora. Storms are rare during solar minimum, but as the sun’s activity ramps up every 11 years toward solar maximum – currently expected in late 2013 — large storms occur several times per year.
In the past, geomagnetic storms caused by CMEs of this strength and direction have usually been mild.
Many of the untold stories of the space race reside with the women. Now, dozens of the wives of Mercury, Gemini and Apollo astronauts have shared their experiences in a new book, “The Astronaut Wives Club” (Grand Central Publishing, June 2013).
SPACE.com caught up with author Lily Koppel to learn what life was like for an astronaut wife during the 1960s and ’70s, from stress and sacrifice to glamour and glory.
SPACE.com: Why do you think the stories of astronaut wives were largely ignored as part of the history of space race for so long?
Lily Koppel: They just saw this as part of their duty. They weren’t outspoken, they weren’t being heroes. We can now have the perspective to look back and say it’s not just about the guys in the silver suits, but there’s this whole community of engineers, and there was this whole story at home. These wives were basically single mothers during the week who were mowing the lawn, keeping the checkbook balanced, making sure their husbands aren’t overly stressed at home, per NASA’s recommendations.
Why I was so excited about writing it was because it really was sort of the heart of the endeavor, the emotional story of the space race.
SPACE.com: Do you think people at the time had a really false idea of what these women’s lives were like?
Koppel: I think so. When a journalist would ask how they felt, it was like, ‘God, if I told you how I really felt, my husband would never get another spaceflight!’ So it was just, ‘Happy, proud and thrilled.’ That was really their motto throughout the program, that’s how everything was.
Even the wives say now, looking back at those pictures, ‘Don’t we look like Stepford wives? But we were so much more than Stepford wives.’ They were like supermoms.
SPACE.com: Was it hard for the people you interviewed now to be honest with you about what it was really like?
Koppel: Yeah, I had to coax some of them. They’re still very protective of NASA and even if they were divorced from their astronaut, they still had a strong sense of loyalty to him or to the program. I just had to tell them that this wasn’t going to be like a National Enquirer piece — it was going to look at their stories with a great deal of dignity, but we really did have to push beyond the vanilla ice cream. But I think that was good and I think they enjoyed being provoked a little.
I think that honestly they feel that they have been shut out of a lot of history. Whenever there are these NASA anniversaries and everyone gathers, a lot of the times it’s the astronauts and their second or third or fourth wife. These women are like, ‘They didn’t live through it — we did.’
And they really went through so much in that decade that they really deserve to be recognized as playing this incredibly important role. It was a huge sacrifice for them. In a way, they gave up a lot of their future, because sometimes it was just impossible, there was no way the marriage was going to survive because they were just living under extraordinary circumstances.
SPACE.com: Why do you think it was so many of these marriages failed?
Koppel: The husbands were like rock stars being followed around by space groupies, the “Cape Cookies,” you know. When you go back and look at things and talk to the astronauts, it was very much condoned, the kind of behavior of, ‘OK, the Cape is where you’re going to be training, you can definitely unwind on the side and questions aren’t necessarily going to be asked. Just make sure it doesn’t affect things at home and it doesn’t make it into the press.’
So NASA knew these wives were being gung ho and giving their all back at home, and it was basically higher ups like Alan Shepard and Deke Slayton bringing new boys in and giving them a little pep talk. It was very much of the times, very ‘Mad Men’-esque. Like, ‘Listen, we’re hot pilots, do your thing, but make sure it doesn’t make it into the papers.’ So I think a lot of the wives were sort of innocent, and they were also in a bit of denial as well.
SPACE.com: Did you get the sense that the wives enjoyed their lives, or was mostly a hardship?
Koppel: No, they definitely enjoyed it.
What I want to convey is they were almost in their own crazy NASA space program — that they had this equally hard role of keeping the home fires burning bright and projecting this perfect American family image to the world, but I think they certainly enjoyed it. It was the most exciting time of their lives.
As Marilyn Lovell [wife of Apollo 13 astronaut Jim Lovell] said to me when I was interviewing her, she started crying and she said, “That was the best time of my life.” Or Jane Conrad [wife of Apollo 12 astronaut Pete Conrad] looks back and says “It just feels like a dream.”
Because everything was moving so fast and everyone was trying to get to the moon, and the wives were sort of in it as much as their husbands. If he couldn’t make it home for two or three weekends in a row because he was training, it was just part of the sacrifice. But then there were incredible things like round-the-world tours after your husband came back, and meeting heads of state, and feeling like you were higher-than-high society and royalty. Your husband had gone where none of these international jet set could even dream of going.
SPACE.com: Among the few rare couples that survived, were there any great love stories?
Koppel: Oh yeah. The Lovells are incredible. They’ve been together since high school. They have such a cute story. They met because Jim Lovell’s prom date dumped him, and he asked Marilyn to fill in for him and they’ve been together ever since.
Of course after Apollo 13, Marilyn was terrified. She thought, every time he even went to go to the drug store, that he wasn’t going to come home, and she was just absolutely paralyzed by fear. And she finally said, ‘I have to see a psychiatrist,’ which was really taboo at the time. Even within NASA, they only used outside doctors if they had a problem because they were so scared of not getting a flight. But Marilyn finally told Jim after Apollo 13, ‘You’re not flying again.’
In the fall, I became immersed in scientific and philosophical theories. In particular, I was obsessed with scientific diagrams, which explain theories and properties through drawings. My interests also included subjects such as self-aware systems, philosophy, cellular automata, phase transitions, time travel, mystical behaviors at atomic and sub-atomic levels, and the mysteries of consciousness. Although these rudimentary drawings were without any leanings towards aesthetics, I found them to be beautiful, though that is clearly not their intention. I was inspired to create my own interpretations of the concepts of consciousness and other theories on a scientific, philosophical, and spiritual level through a simplified means such as drawing. All of the projects I have created begin as drawings, which I feel have a beauty and intimacy that paintings cannot capture. The subtle lines that graphite creates and the quickness with which one can capture an idea makes this medium alluring.
My wife Paula and I felt that these completed works would be best presented together in a beautifully designed book, and we strongly believed that they should be accompanied by the writings of arts professionals and scientists from varying disciplines to offer their interpretations of the connection between science and art. I am deeply grateful to have such an esteemed group of scientists and writers as contributors to this book.
Top:External right pinna - Human (Homo sapiens sapiens) - Humans can typically hear sounds between 20 Hz and 20,000 Hz. Anything above 20,000 Hz is referred to as “ultrasonic”; anything below 20 Hz is referred to as “infrasonic”.
Center row:Examples of mammals without visible external ears - Caspian seal (Pusa caspica), European mole (Talpa spp.), Pale-throated sloth (Bradypus tridactylus) - The Caspian seal and mole have generally poor hearing, but the sloths can hear quite well despite their small ears. Caspian seals can hear better underwater, as they can pick up sounds using bone-conduction, rather than through the air.
Bottom:African Wild Dogs (Lycaon pictus) - As pack animals that split apart and use tactical hunting strategies, being able to hear sounds from far away is critical to making a kill. Their large outer ears capture the calls of their pack with ease.
The pinna (Latin for “feather”) is the external anatomy of the ear, visible in almost all mammals. It’s also known as the auricle, or auricula. In humans, the pinna functions to amplify sounds in the range of 2.5-4 kHz - the typical range that human voices fall in.
In some animals, the pinna also functions to cool off the body, by dispersing heat through a large surface area, such as in the fennec fox and African elephant. Other animals, such as the bloodhound, use their outer ears to funnel scents towards their noses.
Mammalian auricles are typically movable (though in most humans, they’re stationary), and designed to capture sound from a broad area. Many prey animals have large or very mobile auricles, allowing them to detect predators from far away. Some predators that rely heavily on communication (such as African wild dogs) also have large auricles.
The human sense of hearing is middling at best, compared to many other mammals, but without the outer ear, up to 80% of the most relevant frequencies (5000-15000 Hz) are unable to be detected.
Anatomy: Descriptive and Surgical. Henry Gray, 1911. Brehms’ Tierleben, Allgemeine Kunde des Tierreichs. Prof. Otto zur Strassen, 1912.
Nanotube Probe Gives a Single Neuron’s View of Brain Activity
A thin probe of carbon nanotubes can measure small electrical changes inside a neuron.
A tiny spear made of carbon nanotubes can probe the internal electrical activity of a single neuron, giving researchers a more refined look at how brain cells respond to signals from their neighboring cells. Probing the brain at this resolution could be vital to efforts to understand and map its function in new detail (see “Why Obama’s Brain-Mapping Project Matters”).
The neuron “harpoons” are just 5 to 10 micrometers wide and can pierce a living cell to measure electrical changes associated with neuronal signaling. In dissected slices of still-active mouse brain tissue, researchers at Duke University were able to record from inside a single neuron at a time.
“To our knowledge, our paper shows the first intracellular recording with carbon nanotubes from vertebrate neurons,” says Bruce Donald, a biochemist and computer scientist at Duke University and author on the study, which was published in PLoS ONE on Wednesday.
Carbon nanotubes have many desirable properties for brain recordings, says Donald: they are strong, they are compatible with body tissues, and they conduct electricity well. But previous devices built from carbon nanotubes have been too short or wide to be well suited for recording inside cells. The probes built by the Duke researchers, however, were around one millimeter long and lent themselves to monitoring electrical activity more precisely than typical glass or metal electrode setups.
The team was able to detect small changes in electrical activity in the cell—changes corresponding to the input signals the neuron was receiving from other neurons. An average cortical neuron can receive signals from around 10,000 other neurons, says Richard Mooney, a neuroscientist at Duke University and an author on the study. “Individually, those generate very small signals,” he says. Together, the collection of signals is computed by the receiving neuron as it decides whether or not to fire.
Intracellular recordings could be useful for mapping the functional connections between neurons, a goal of the recently launched BRAIN initiative (see “The Brain Activity Map”). “By being able to look inside the cell and measure small voltage changes, you get access to the network that talks to that cell,” say Mooney.
The researchers used a “clever technique” to build their device, says Takashi Kozai, a neural engineer who was not involved in the study. Starting at the tip of a tungsten wire, they built up a long needle-like probe made of tangled carbon nanotubes. Then they coated the probe with an insulating material and used a focused beam of ions to bombard the tip, removing the insulation from that area and shaving it to a fine point.
“With this technique, you can make [probes] as long as you want,” says Kozai, who is also developing microscopic electrodes for recording neuron activity (see “A Carbon Microthread That Makes Contact with the Mind”). The work “sets the stage for making even narrower devices, maybe on the order of 100 nanometers instead of microns,” he says.
In addition to dissected brain slices, the team tested their thin electrode in anesthetized mice, although they were not able to obtain recordings from inside the brain cells of these animals. However, if future versions of the nanotube tip are even sharper, they may be able to better pierce cells in soft and spongy brains, says Kozai. If that’s possible, and if the device is stable in living brains over time, it could help researchers explore how the living brain learns and remembers.
“If they can stably record from the same cell longitudinally,” Kozai says, “it could be applied to map how neurons change during memory formation and learning.”
(Above, left: Hook on: A micrograph shows a new brain electrode that is thin and long enough to record from inside a single neuron. right:Sharp end: The neuro-harpoon comes to a very fine point.)