Powerful laser pulses vaporised the nanocrystals almost instantly, but not before the crystals had scattered X-rays, producing diffraction patterns that could be combined to render the crystal's detailed structure in three dimensions.
The ability to glean structural data from such tiny crystals could allow many more proteins to be understood. Other methods of elucidating structure require larger crystals, which, for some proteins, can be difficult or impossible to prepare.
Many people in society simply cannot function without a daily dose of caffeine. It is so prevalent in many diets. From coffee, to tea, to soft drinks, it has become a staple on par with corn or wheat, or even water. Of course caffeine is not necessary to survive, but it is sure good at keeping our eyes open. However, according to a new study from researchers at the University of Texas, caffeine does more than just keep us awake. It also energizes cells into producing more viruses used for gene therapy.
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Caffeine is the world's most widely consumed psychoactive substances, and amazingly, is completely legal and unregulated. It is found naturally in many plant species such as coffee, tea, and cocoa beans. Plants generate it because it paralyzes and kills certain insects which feed upon them. Therefore, it is the only stimulate we consume that is also a pesticide.
However, the amazing new property discovered by researchers can have lasting impacts on gene therapy research. Gene therapy is the manipulation of genes within the body's tissue cells with the goal of treating disease. It can correct defective genes which are responsible for disease development.
The problem is how to manipulate the genes. For a long time, scientists have known that viruses reproduce by binding to their hosts and introducing their unique genetic material into the cell. This genetic material gives instructions to the cell to produce copies of itself, hijacking the cell’s natural production. For gene therapists, viruses can be used to manipulate cells with "good" genetic material. This is known as the viral vector.
The new study recently published in the journal Human Gene Therapy claims that caffeinated cells used to produce viruses for gene therapy can generate up to 8 times more than non-caffeinated cells. According to the researchers, using caffeine should decrease the cost of producing lentiviruses for research and clinical uses. Lentiviruses are a common type of virus used in gene therapy.
"It is ironic that the ingredient in beverages like colas and coffees that helps keep us awake and alert is also useful in jazzing up cells to produce more gene therapy vectors. An increase in vector production of 5-fold may prove critical in establishing the commercial viability of lentiviral based products," says James M. Wilson, MD, PhD, and Director of the Gene Therapy Program.
The researchers emphasize that the timing of introducing caffeine into cells is critical for increased virus production. Also the concentration of caffeine cannot be too high because it can be toxic to the cells, and would not cause them to increase virus production.
Researchers involved with the study from the University of Texas Southwestern Medical Center, Dallas include Brian Ellis, Patrick Ryan Potts, and Matthew Porteus. Their work can be found in the journal Human Gene Therapy which is published by Mary Ann Liebert, Inc.
Researchers at Princeton University developed a technique for generating a laser beam out of nothing but air. They focus a pump laser on a distant point in the air and another laser beam comes back. The image shows a pulse of infra-red light from this "air laser." The center region represents the highest intensity; the outer areas have lower intensity light. The technique could be used for sensing minute quantities of gas in the air from a distance. Credit: Image courtesy Arthur Dogariu, Princeton University
Princeton University engineers have developed a new laser sensing technology that may allow soldiers to detect hidden bombs from a distance and scientists to better measure airborne environmental pollutants and greenhouse gasses.
"We are able to send a laser pulse out and get another pulse back from the air itself," said Richard Miles, a professor of mechanical and aerospace engineering at Princeton, the research group leader and co-author on the paper. "The returning beam interacts with the molecules in the air and carries their finger prints."
The new technique differs from previous remote laser-sensing methods in that the returning beam of light is not just a reflection or scattering of the outgoing beam. It is an entirely new laser beam generated by oxygen atoms whose electrons have been "excited" to high energy levels. This "air laser" is a much more powerful tool than previously existed for remote measurements of trace amounts of chemicals in the air.
The researchers, whose work is funded by the Office of Naval Research's basic research program on Sciences Addressing Asymmetric Explosive Threats, published their new method Jan. 28 in the journal Science.
Miles collaborated with three other researchers: Arthur Dogariu, the lead author on the paper, and James Michael of Princeton, and Marlan Scully, a professor with joint appointments at Princeton and Texas A&M University.
Researchers at Princeton University developed a technique for generating a laser beam out of nothing but air. They focus a pump laser on a distant point in the air and another laser beam comes back. The video shows 100 pulses of infra-red light from this "air laser." The center region represents the highest intensity; the outer areas have lower intensity light. The technique could be used for sensing minute quantities of gas in the air from a distance. Credit: Image courtesy Arthur Dogariu, Princeton University
The new laser sensing method uses an ultraviolet laser pulse that is focused on a tiny patch of air, similar to the way a magnifying glass focuses sunlight into a hot spot. Within this hot spot – a cylinder-shaped region just 1 millimeter long – oxygen atoms become "excited" as their electrons get pumped up to high energy levels. When the pulse ends, the electrons fall back down and emit infrared light. Some of this light travels along the length of the excited cylinder region and, as it does so, it stimulates more electrons to fall, amplifying and organizing the light into a coherent laser beam aimed right back at the original laser.
Researchers plan to use a sensor to receive the returning beam and determine what contaminants it encountered on the way back.
"In general, when you want to determine if there are contaminants in the air you need to collect a sample of that air and test it," Miles said. "But with remote sensing you don't need to do that. If there's a bomb buried on the road ahead of you, you'd like to detect it by sampling the surrounding air, much like bomb-sniffing dogs can do, except from far away. That way you're out of the blast zone if it explodes. It's the same thing with hazardous gases – you don't want to be there yourself. Greenhouse gases and pollutants are up in the atmosphere, so sampling is difficult."
The most commonly used remote laser-sensing method, LIDAR -- short for light detection and ranging -- measures the scattering of a beam of light as it reflects off a distant object and returns back to a sensor. It is commonly used for measuring the density of clouds and pollution in the air, but can't determine the actual identity of the particles or gases. Variants of this approach can identify contaminants, but are not sensitive enough to detect trace amounts and cannot determine the location of the gases with much accuracy.
The returning beam is thousands of times stronger in the method developed by the Princeton researchers, which should allow them to determine not just how many contaminants are in the air but also the identity and location of those contaminants.
The stronger signal should also allow for detection of much smaller concentrations of airborne contaminants, a particular concern when trying to detect trace amounts of explosive vapors. Any chemical explosive emits various gases depending on its ingredients, but for many explosives the amount of gas is miniscule.
While the researchers are developing the underlying methods rather than deployable detectors, they envision a device that is small enough to be mounted on, for example, a tank and used to scan a roadway for bombs.
So far, the researchers have demonstrated the process in the laboratory over a distance of about a foot and a half. In the future they plan to increase the distance over which the beams travel, which they note is a straightforward matter of focusing the beam farther way. They also plan to fine-tune the sensitivity of the technique to identify small amounts of airborne contaminants.
In addition, the research group is developing other approaches to remote detection involving a combination of lasers and radar.
"We'd like to be able to detect contaminants that are below a few parts per billion of the air molecules," Miles said. "That's an incredibly small number of molecules to find among the huge number of benign air molecules."
The Force is strong with holographic scientists these days. Researchers from MIT unveiled the fastest 3-D holographic video to date at a conference in San Francisco January 23, filming a graduate student dressed as Princess Leia and projecting her as a postcard-sized hologram in real time.
The holographic device plays a 3-inch projection at 15 frames per second, just shy of movie refresh rates of 24 to 30 frames per second, the MIT researchers demonstrated at the Society of Photo-Optical Instrumentation Engineers’ conference on practical holography.
The red hologram is jerkier and has much lower resolution than the one in Star Wars that sparked the public fascination with 3-D holograms in the 1970s. In fact, it kind of looks like a red blob on a staticky TV. But it’s 30 times faster than a telepresence device created in 2010 by University of Arizona researchers (SN Online: 12/4/10).
“I think it’s an important milestone because they were able to get to 15 frames per second, which is almost real time,” says physicist Nasser Peyghambarian, who led the Arizona research. “The quality is not as high, but hopefully it will get better in the future.”
The key to speed was computational power. The MIT team used a Kinect camera from an Xbox 360 gaming console to capture light from a moving object. Then they relayed the data over the Internet to a PC with three graphics processing units, or GPUs, tiny processors found in computers, cell phones, and video games that render video quickly. The processors compute how light waves interfere with each other to form patterns of light and dark fringes. Light bouncing off these fringe patterns reconstructs the original image. The MIT team used a display to illuminate the computer-generated fringes and create a hologram.
“The students were able to figure out how to generate holograms by using what GPU chips are good at,” says Michael Bove, an MIT engineer who led the research. “And they get faster every year. There’s room for a lot more understanding of how to compute holograms on them.”
MIT’s holograms are fast, says Peyghambarian, but they have to trade quality for speed.
Bove’s device uses one camera that estimates the depth of the object it is filming. The disadvantage of one camera, which is more consumer-friendly, is that you can’t see behind objects, says Bove. Also, even though graphics cards can compute high-resolution holograms, the effective display size is limited by a chip in the physical display to 150 millimeters by 75 millimeters, which Bove says is the biggest challenge to creating better holograms.
The Arizona device had a very different setup: Researchers grabbed video from 16 cameras angled around the object, so that one could walk around a holographic person and see not just the front side, but side profiles and back views. The team used an old-fashioned method that hologram artists have employed for decades, employing two lasers to create fringe patterns. Their key insight was engineering a special type of plastic that erases and rewrites quickly. The Arizona hologram is already high-definition and the size of a 17-inch TV, but speeding it up will require switching to a new laser system, says Peyghambarian.
“There’s a variety of technologies,” says Bove. “The fact is, the barrier to entry has been unbelievably high for the past 20 years. Now, many technologies are maturing at the same time. I think we’ll see some fun things in the next few years.”
Bove looks to the near future for consumer teleconferencing that connects people far, far away from each other, just like Darth Vader and the Emperor in their imperial chats. Star Wars purists will remember that Princess Leia’s plea was actually prerecorded.
A storm is hovering over the editors of the Journal of Personality and Social Psychology, which is to publish a paper offering evidence for precognition – knowledge of unpredictable future events. Feeling The Future, written by Daryl Bem, an emeritus professor of Cornell University, reports the results of nine experiments with more than 1,000 subjects, all but one of which appear to suggest paranormal powers. His findings are due to be published by the respected journal this year, and sceptics have been queueing up to rubbish them.
Among Bem's contentions is that participants given a memory test were more likely to remember words that they were later asked to practise, suggesting that the effects of this post-test rehearsal somehow reached back in time. He also found that subjects asked to select which of two curtains on a computer screen hid an erotic image were able to do so at a significantly greater rate than chance would predict. Intriguingly, the same experiment didn't produce any unusual results when the images behind the virtual curtain were less titillating.
The study is striking not so much for its data – anomalous results from smallish one-off experiments can hardly be described as earth-shattering – but for the fact that it comes from such a distinguished source (Bem is a highly acclaimed research psychologist), and because it has been accepted by such a prominent publication, following the usual peer review procedures. But perhaps even more interesting is the reaction it is producing among some critics – Ray Hyman, another emeritus psychology professor has described the publication as "pure craziness ... an embarrassment for the entire field", while Robert Park, a physicist at the University of Maryland called it "a waste of time ... it leads the public off into strange directions that will be unproductive".
The strength of such denunciations are curious. If Bem's experiments are indicative of ESP, then the implications are fascinating and wide-ranging, and at least worthy of continued investigation. Indeed, part of Bem's motivation, he says, was to construct easily replicable trial procedures so that interested parties could help build a reliable evidence base. If his trials are flawed, then they should be challenged robustly in the public domain.
Leaps in understanding require daring as well as rigour, and while extraordinary claims may require extraordinary evidence, there does seem to be sufficient data for ESP to at least merit an ongoing debate. Dean Radin's book The Noetic Universe offers reams of serious studies purporting to show phenomena such as perception at a distance, mind-matter interaction and telepathy – including meta-analyses of apparently well-conducted trials – that appear to add up to something interesting. Radin also suggests that theories underpinning psychic phenomena are no weirder – and indeed potentially compatible with – those regularly put forward and accepted in mainstream physics, or in mind-body medicine.
To the interested observer, the wide divergence of views among psi experts can be as befuddling as the evidence itself. When the people who have devoted their careers either to proposing or debunking the existence of the paranormal can't agree on the fundamentals of their field, even when presented with the same data, then what chance does the lay observer have? The arguments tend to stand or fall on the finer points of study design or statistical interpretation. One of the main critiques of Bem's study is not that his results are suspect, but that he has analysed them insufficiently, although it's worth noting that one of the sceptic re-analyses concludes that his data offers a "surprising degree of evidence" in favour of precognition.
But perhaps the most telling statistic in Bem's paper is that 34% of psychologists consider psychic phenomena to be impossible. Improbable, maybe. Unproven, perhaps. But impossible? That certainty seems to reflect a clinging to orthodoxy that is as much belief-based as the public's conviction that psychic powers are real and in our possession (apparently, 62% of us claim to know who's calling before we pick up the phone).
Daryl Bem's experiments may or may not give us evidence that precognition exists – but if publication of his paper can show that interest in psychic phenomena isn't limited to crackpot true believers, and that studies of it are worthy of more than blind dismissal or uncritical acceptance, then it will have more than served a purpose.
Amateur astronomer Gus Johnson didn't set out to witness what scientists say is the first ever observed birth of a black hole. But that's just what he did in 1979. His discovery of Supernova 1979c was only the third supernova in another galaxy ever detected by an amateur. But it has become one of the most important and studied since. Amateur astronomers have been making discoveries for at least 400 years, dating to Galileo's spotting of Jupiter's moons. The hobby helps professional scientists every day.
Johnson likes the quiet and he likes the dark. But clouds and sub-zero temperatures are working against him as he stargazes near his home in Western Maryland.
"Well, Jupiter went behind a cloud so we have the moon," said Johnson.
Johnson has been stargazing for 50 years, and tonight he's invited some kids to join him. He has a near photographic memory of hundreds of star positions and he loves to share what he knows.
"That planet has a diameter 11 times that of the Earth," he said.
Johnson is the maintenance man at Deep Creek's Lake Nature Center. He's also an avid reader of Sky and Telescope magazine. In 1979, he was featured in the magazine - for discovering a supernova that scientists now believe is the newest and nearest black hole.
"When I came to M100 [galaxy] there was this little star that for some reason caught my attention," said Johnson. "I don't know why, and later on when I checked the photograph it was not on the photograph and that proved to be the the Supernova1979c."
Was he pretty proud?
"Yes I was," he replied. "And I am. And thankful too because so few people actually get to discover things."
Backyard astronomers have been making discoveries for centuries dating back to Galileo, whom amateurs claim as one of their own. His degree was in art. The famous Comet Hale-Bopp was discovered in 1995 by two amateurs, one of whom did not even own a telescope. He was using a friend's. And in 2007, volunteers in an online astronomy project discovered the "green pea" galaxies, so-named because they appear small and greenish in images.
Astrophysicist Kim Weaver was part of the NASA team that announced last month that Gus Johnson's supernova, or exploding star, was likely the birth of a black hole, a region in space where nothing can escape, not even light.
"We want to watch how this system evolves and changes in its youthful stages from when it's first born to when it grows into a child and a teenager," said Weaver.
Scientists believe that black holes are born often in the universe. But to actually see it happen, well that's a story.
When Johnson spotted the star more than 30 years ago, he put out an alert, and telescopes including NASA'S powerful Chandra X-Ray Observatory have been watching it ever since.
We caught up with Weaver at the Goddard Space Flight Center in Maryland where she works.
"This is what we think happens around a black hole, this ecreting material gets sucked into the orbit," she said.
She told us that while some astronomers dismiss the work of so-called citizen scientists, they do put thousands more eyes on the cosmos, which is a good thing.
"They don't have access to the large telescopes that professionals have access to but what they can do is they have the freedom to be able to use smaller telescopes any time they want to look all over the sky," said Weaver.
Professionals, Weaver says, tend to focus on smaller areas and on fainter objects further away. Another problem:
"Professional astronomers have created tons and tons of data," she said. "There are not enough professionals to look at all those data."
That's where backyard astronomers come in.
"So this is the first telescope I ever got. It's my favorite," said Caroline Moore. Moore has has an observatory in her backyard, with top of the line telescopes that she and her father use to track the ever-shifting heavens above New York State.
Two years ago, at age 14, she made a major discovery, not with a telescope but with a computer, scanning hundreds of photos as part of an online search team.
"I discovered the least luminous supernova ever to be observed, and I am the youngest person ever to discover a supernova so it kind of makes it a double interesting thing," she said.
Moore says supernova hunting is competitive.
"Maybe you will find there is some kind of thing on another planet that will help you cure cancer and we won't know that if we don't take even the smallest steps in journeying outside our planet a bit," she said.
Back in Maryland, Gus Johnson observes fresh-fallen snow and an iced-over Deep Creek Lake. There's something almost sad about his intense love of the environment, even with its fleeting nature.
But his discovery, that he holds onto.
Johnson wasn't looking for a supernova that night, it was entirely accidental. But, now he looks for them.
"It's kind of the grand realities of existence," said Johnson. "The Earth and everything we know is such a minute part of the universe. Watching the creation of God. That is pretty spectacular stuff."
