Category: Science


A small African mammal with an unusual ability to regrow damaged tissues could inspire new research in regenerative medicine, a University of Florida study finds.

For years biologists have studied salamanders for their ability to regrow lost limbs. But amphibian biology is very different than human biology, so lessons learned in laboratories from salamanders are difficult to translate into medical therapies for humans. New research in the Sept. 27 issue of the journal Naturedescribes a mammal that can regrow new body tissues following an injury. The African spiny mouse could become a new model for research in regenerative medicine.

“The African spiny mouse appears to regenerate ear tissue in much the way that a salamander regrows a limb that has been lost to a predator,” said Ashley W. Seifert, a postdoctoral researcher in UF’s biology department. “Skin, hair follicles, cartilage — it all comes back.”

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A clock that will last forever

Imagine a clock that will keep perfect time forever, even after the heat-death of the universe. This is the “wow” factor behind a device known as a “space-time crystal,” a four-dimensional crystal that has periodic structure in time as well as space. However, there are also practical and important scientific reasons for constructing a space-time crystal. With such a 4D crystal, scientists would have a new and more effective means by which to study how complex physical properties and behaviors emerge from the collective interactions of large numbers of individual particles, the so-called many-body problem of physics. A space-time crystal could also be used to study phenomena in the quantum world, such as entanglement, in which an action on one particle impacts another particle even if the two particles are separated by vast distances.

A space-time crystal, however, has only existed as a concept in the minds of theoretical scientists with no serious idea as to how to actually build one – until now. An international team of scientists led by researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) has proposed the experimental design of a space-time crystal based on an electric-field ion trap and the Coulomb repulsion of particles that carry the same electrical charge.

This proposed space-time crystal shows (a) periodic structures in both space and time with (b) ultracold ions rotating in one direction even at the lowest energy state.

“The electric field of the ion trap holds charged particles in place and Coulomb repulsion causes them to spontaneously form a spatial ring crystal,” says Xiang Zhang, a faculty scientist with Berkeley Lab’s Materials Sciences Division who led this research. “Under the application of a weak static magnetic field, this ring-shaped ion crystal will begin a rotation that will never stop. The persistent rotation of trapped ions produces temporal order, leading to the formation of a space-time crystal at the lowest quantum energy state.”

Because the space-time crystal is already at its lowest quantum energy state, its temporal order – or timekeeping – will theoretically persist even after the rest of our universe reaches entropy, thermodynamic equilibrium or “heat-death.”

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Traces of memory in a dish

Brain tissue freezer failure

It sounds like the plot of a science fiction film, or like something from a transhumanist fantasy: researchers from Case Western Reserve University in Cleveland, Ohio, report that they can induce memory-like patterns of activity in slices of brain tissue, and that the slices can store these activity patterns for short periods of time.

The brain can encode information about the outside world and retrieve it later on, and the mechanisms underlying this ability are of great interest to neuroscientists. The general consensus among researchers is that memories are formed by the strengthening of connections within networks of nerve cells, and recalled by reactivation of the electrical signals generated by these networks. The new work, published in the journal Nature Neuroscience, contributes to our understanding of these processes.

Robert Hyde and Ben Strowbridge dissected horizontal slices of brain tissue from the hippocampus of rats, placed them into Petri dishes, and used electrodes to manipulate and measure the activity of individual neurons in the slices. The hippocampus is well known to be critical for long-term memory formation and, together with the prefrontal cortex, also plays an important role in working memory, which stores information for short periods of time so that it can be used to perform the task at hand.

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The research, published today in Aging Cell, opens up new avenues of understanding for conditions where the ageing of neurons are known to be responsible, such as dementia and Parkinson’s disease.

The ageing process has its roots deep within the cells and molecules that make up our bodies. Experts have previously identified the molecular pathway that react to cell damage and stems the cell’s ability to divide, known as cell senescence.

However, in cells that do not have this ability to divide, such as neurons in the brain and elsewhere, little was understood of the ageing process. Now a team of scientists at Newcastle University, led by Professor Thomas von Zglinicki have shown that these cells follow the same pathway.

This challenges previous assumptions on cell senescence and opens new areas to explore in terms of treatments for conditions such as dementia, motor neuron disease or age-related hearing loss.

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“Ever since a monk called Mendel started breeding pea plants we’ve been learning about our genomes. In 1953, Watson, Crick and Franklin described the structure of the molecule that makes up our genomes: the DNA double helix. Then, in 2001, scientists wrote down the entire 3-billion letter code contained in the average human genome. Now they’re trying to interpret that code; to work out how it’s used to make different types of cells and different people. The ENCODE project, as it’s called, is the latest chapter in the story of you.”

Trailer of a documentary about the science and philosophy of the longevity movement, and the scientists making science fiction a reality. The film is by Jason Sussberg and David Alvarado.

rat in maze

Researchers working at MIT have successfully manipulated the content of a rat’s dream by replaying an audio cue that was associated with the previous day’s events, namely running through a maze (what else).

The breakthrough furthers our understanding of how memory gets consolidated during sleep — but it also holds potential for the prospect of “dream engineering.” Working at MIT’s Picower Institute for Learning and Memory, neuroscientist Matt Wilson was able to accomplish this feat by exploiting the way the brain’s hippocampus encodes self-experienced events into memory.

Scientists know that our hippocampus is busy at work replaying a number of the day’s events while we sleep — a process that’s crucial for memory consolidation. But what they did not know was whether or not these “replays” could be influenced by environmental cues.

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Scientists Clear Path to the Fountain of Eternal Youth

Researchers at Johns Hopkins have discovered an efficient and totally safe method to turn adult blood cells “all the way back to the way [they were] when that person was a 6-day-old embryo.” The discovery could be the key to cure the incurable—from heart attacks to severed spinal cord to cancer—and open the door, some day, to eternal youth.

Scientists believe that stem cell therapy could change medicine forever. However, these therapies are impossible to implement on a large scale because you can’t acquire embryonic stem cells without having to use actual human embryos—an extremely controversial undertaking. The alternative has always been to use the stem cells found in umbilical cords—which is why rich people use umbilical cord storage facilities to guarantee future treatments for their kids—or use viruses to reprogram adult cells. These viruses can successfully return adult cells to their stem cell state, but the procedure opens the door to numerous complications as a result of potential DNA mutations. And those mutations could lead to cancer.

But this new method changes everything. To start with, it uses normal adult blood cells from the patient, so there’s not need to keep umbilical cords in storage. It also doesn’t use any virus reprogramming, so it’s completely safe. It’s also very efficient: researchers successfully transformed about 50 to 60 percent of adult blood cells into embryonic stem cells that can then be turn into any type of cell—a heart muscle cell, a bone cell, a nerve cell, anything.

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During experiments on the axons of the Woods Hole squid (loligo pealei), Backyard Brains tested their cockroach leg stimulus protocol on the squid’s chromatophores. The results were both interesting and beautiful. The video is a view through an 8x microscope zoomed in on the dorsal side of the caudal fin of the squid. They used a suction electrode to stimulate the fin nerve. Chromatophores are pigmeted cells that come in 3 colors: Brown, Red, and Yellow. Each chromatophore is lined with up to 16 muscles that contract to reveal their color.

When an audio signal is converted to an electric signal, basically what happens inside a microphone, that electric voltage can be applied to tissues! The resulting voltage changes can trigger electrochemical signals, just like the chromatophores you’ll see on the video.

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An extremely small penny-sized rocket thruster has been developed to power the smallest satellites in space, replacing the bulky and heavy engines currently in use.

The device was designed by Paulo Lozano, an associate professor of aeronautics and astronautics at MIT. It shows little resemblance to the bulky satellite engines in use today, which are composed of many valves, pipes and heavy propellant tanks.

In contrast the new design is “a flat, compact square — much like a computer chip — covered with 500 microscopic tips that, when stimulated with voltage, emit tiny beams of ions. Together, the array of spiky tips creates a small puff of charged particles that can help propel a shoebox-sized satellite forward.”

“They’re so small that you can put several [thrusters] on a vehicle,” Lozano says. He adds that a small satellite outfitted with several microthrusters could “not only move to change its orbit, but do other interesting things — like turn and roll.”

“Today, more than two dozen small satellites, called CubeSats, orbit Earth. Each is slightly bigger than a Rubik’s cube, and weighs less than three pounds. Their diminutive size classifies them as ‘nano-satellites’ in contrast with traditional Earth-monitoring behemoths. These petite satellites are cheap to assemble, and can be launched into space relatively easily: Since they weigh very little, a rocket can carry several CubeSats as secondary payload without needing extra fuel.”

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DNA strand, over a page of TGAC base pairs

A bioengineer and geneticist at Harvard’s Wyss Institute have successfully stored 5.5 petabits of data — around 700 terabytes — in a single gram of DNA, smashing the previous DNA data density record by a thousand times.

The work, carried out by George Church and Sri Kosuri, basically treats DNA as just another digital storage device. Instead of binary data being encoded as magnetic regions on a hard drive platter, strands of DNA that store 96 bits are synthesized, with each of the bases (TGAC) representing a binary value (T and G = 1, A and C = 0).

To read the data stored in DNA, you simply sequence it — just as if you were sequencing the human genome — and convert each of the TGAC bases back into binary. To aid with sequencing, each strand of DNA has a 19-bit address block at the start (the red bits in the image below) — so a whole vat of DNA can be sequenced out of order, and then sorted into usable data using the addresses.

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Not Breathing? No problem!

Scientists Invent Particles That Will Let You Live Without Breathing

This may seem like something out of a science fiction movie: researchers have designed microparticles that can be injected directly into the bloodstream to quickly oxygenate your body, even if you can’t breathe anymore. It’s one of the best medical breakthroughs in recent years, and one that could save millions of lives every year.

The invention, developed by a team at Boston Children’s Hospital, will allow medical teams to keep patients alive and well for 15 to 30 minutes despite major respiratory failure. This is enough time for doctors and emergency personnel to act without risking a heart attack or permanent brain injuries in the patient.

The solution has already been successfully tested on animals under critical lung failure. When the doctors injected this liquid into the patient’s veins, it restored oxygen in their blood to near-normal levels, granting them those precious additional minutes of life.

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Scientists from Maryland’s Johns Hopkins University, in conjunction with Danish researchers, have developed a drug using a Mediterranean weed that can target tumor cells and destroy them.

The extraordinary drug travels undetected through the bloodstream until it encounters a tumor cell, where it is activated by specific proteins. It destroys the tumor cells, neighboring cancer cells, and the blood vessels that act as their supply, but spares healthy cells and blood vessels.

thapsia garganica

The drug, called G202, was tested on mice and the study was led by Samuel Denmeade, MD, professor of oncology, urology, pharmacology and molecular sciences at Johns Hopkins University. Over the course of 30 days, the human prostate tumors grown in mice were reduced by an average of 50 percent. In comparison tests with the chemotherapy drug docetaxel, G202 reduced eight of nine tumors by more than 50 percent over the course of 21 days. Docetaxel reduced only one of the nine tumors in the same amount of time.

G202 also provided the same results for human models of bladder, kidney, and breast cancers.

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Inspired by the erratic behavior of photons zooming around and bouncing off objects and walls inside a room, researchers from the Massachusetts Institute of Technology (MIT), Harvard University, the University of Wisconsin, and Rice University combined these bouncing photons with advanced optics to enable them to “see” what’s hidden around the corner. This technique, described in a paper published today in the Optical Society’s (OSA) open-access journal Optics Express, may one day prove invaluable in disaster recovery situations, as well as in noninvasive biomedical imaging applications.

Seeing through walls: Laser system reconstructs objects hidden from sight

“Imagine photons as particles bouncing right off the walls and down a corridor and around a corner—the ones that hit an object are reflected back. When this happens, we can use the data about the time they take to move around and bounce back to get information about geometry,” explains Otkrist Gupta, an MIT graduate student and lead author of today’s Optics Express paper.

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By decoding brain activity, scientists were able to “see” that two monkeys were planning to approach the same reaching task differently—even before they moved a muscle.

Anyone who has looked at the jagged recording of the electrical activity of a single neuron in the brain must have wondered how any useful information could be extracted from such a frazzled signal. But over the past 30 years, researchers have discovered that clear information can be obtained by decoding the activity of large populations of neurons. Now, scientists at Washington University in St. Louis, who were decoding brain activity while monkeys reached around an obstacle to touch a target, have come up with two remarkable results.

Their first result was one they had designed their experiment to achieve: they demonstrated that multiple parameters can be embedded in the firing rate of a single neuron and that certain types of parameters are encoded only if they are needed to solve the task at hand. Their second result, however, was a complete surprise. They discovered that the population vectors could reveal different planning strategies, allowing the scientists, in effect, to read the monkeys’ minds.

By chance, the two monkeys chosen for the study had completely different cognitive styles. One, the scientists said, was a hyperactive type, who kept jumping the gun, and the other was a smooth operator, who waited for the entire setup to be revealed before planning his next move. The difference is clearly visible in their decoded brain activity.

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Researchers at Case Western Reserve University School of Medicine have discovered a mutant form of the gene, Chk1, that when expressed in cancer cells, permanently stopped their proliferation and caused cell death without the addition of any chemotherapeutic drugs. This study illustrates an unprecedented finding, that artificially activating Chk1 alone is sufficient to kill cancer cells.

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A new bionic eye implant could allow blind people to recognize faces, watch TV and even read. Nano Retina’s Bio-Retina is one of two recent attempts to help patients with age-related macular degeneration, which affects 1.5 million people in the U.S. Although a similar implant, Second Sight’s Argus II, has been on the market in Europe since last year, it requires a four-hour operation under full anesthesia because it includes an antenna to receive power and images from an external apparatus. The Bio-Retina implant is smaller because it doesn’t have an antenna. Instead, the implant captures images directly in the eye, and a laser powers the implant remotely. Because of Bio-Retina’s compact size, an ophthalmologist can insert it through a small incision in the eye in 30 minutes—potentially more appropriate for seniors. The Bio-Retina will generate a 576-pixel grayscale image. And clinical trials could begin as soon as next year.

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Brain wiring a no-brainer?

First map of the human brain reveals a simple, grid-like structure between neurons. How these connections actually work to construct who we are is a different, far more fascinating matter.

Bonnie Bassler discovered that bacteria “talk” to each other, using a chemical language that lets them coordinate defense and mount attacks. The find has stunning implications for medicine, industry — and our understanding of ourselves.

Did you know your face actually turns slightly red each time your heart beats, when fresh blood pumps through it? Neither did I, and that’s because it’s so slight that our visual perception system doesn’t pick up on it. Ah, but what if you could use a computer program to magnify the changes so they become visible? That’s just what computer scientists at MIT did, and the result is fascinating: watch the video (starting at 1:25) and see how with every heartbeat, a man’s face turns tomato red, then fades to a pallid yellow. The program is so precise that it can accurately calculate a person’s heart rate from the color changes.

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