David Kirkpatrick

August 30, 2010

Flying robots with hands …

pretty cool tech, actually.

From the link:

A robotic hand attached to a small helicopter can successfully and autonomously grip objects while the helicopter is hovering, as demonstrated by a group at Yale University led by Aaron Dollar, one of this year’s TR35s.

The helicopter hand, dubbed the Yale Aerial Manipulator, could be used in spots that are difficult for ground robots to get to, such as high or roughly terrained places. It could also be used to pick up bombs or packages, or even as a form of delivery, moving packages in urban environments where trucks would have a hard time, suggests Paul Pounds, first author of the work.

Hit the link for video of the Yale Aerial Manipulator in action.

June 18, 2010

Beautiful space image — a star is born

Filed under: Science — Tags: , , , , , — David Kirkpatrick @ 1:54 am

Literally. This is an image of the birth of a star

From the link:

Astronomers have glimpsed what could be the youngest known star at the very moment it is being born. Not yet fully developed into a true star, the object is in the earliest stages of star formation and has just begun pulling in matter from a surrounding envelope of gas and dust, according to a new study that appears in the current issue of the Astrophysical Journal.

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April 21, 2010

More cancer-fighting nanotech

Filed under: Science, Technology — Tags: , , , , , , — David Kirkpatrick @ 1:26 am

Research has found carbon nanotubes can help the body’s immune system fight cancer. Hit this link for all my cancer-related nanotechnology blogging.

From the first link:

Carbon nanotubes boost cancer-fighting cells

New Haven, Conn.—Yale University engineers have found that the defects in carbon nanotubes cause T cell antigens to cluster in the blood and stimulate the body’s natural immune response. Their findings, which appear as the cover article of the April 20 issue of the journal Langmuir, could improve current adoptive immunotherapy, a treatment used to boost the body’s ability to fight cancer.

Adoptive immunotherapy involves extracting a patient’s blood so that the number of naturally occurring T cells (a type of white blood cell) can reproduce more effectively in the laboratory. Although the body produces its own tumor-fighting T cells, they are often suppressed by the tumor and are too few to be effective. Scientists boost the production of T cells outside the body using different substances that encourage T cell antigens to cluster in high concentrations. The better these substances are at clustering T cell antigens, the greater the immune cell proliferation. Once enough T cells are produced, the blood is transferred back into the patient’s body.

The Yale team had previously reported the unexpected effect that carbon nanotubes had on T cell production. They found that the antigens, when presented on the surface of the nanotubes, stimulated T cell response far more effectively than coating other substrates such as polystyrene in the antigens, even though the total amount of antigens used remained the same.

Now they have discovered the reason behind the increased stimulation. They found that the antigens cluster in high concentrations around the tiny defects found in the carbon nanotubes.

“Carbon nanotube bundles resemble a lymph node microenvironment, which has a labyrinth sort of geometry,” said Tarek Fahmy, associate professor of chemical engineering and biomedical engineering at Yale and senior author of the paper. “The nanotube bundles seem to mimic the physiology and adsorb more antigens, promoting a greater immunological response.”

Current adoptive immunotherapy takes weeks to produce enough T cells, but lab tests showed that the nanotubes produced the same T cell concentration in just one-third the time, Fahmy said.

Carbon nanotubes can cause problems, such as an embolism, when used in the body. But this isn’t the case when they are used in blood that has been extracted from the patient, Fahmy said. Next, the team will work on a way to effectively remove the carbon nanotubes from the blood before it is returned to the patient.

“We think this is a really interesting use of carbon nanotubes. It’s a way to exploit the unique properties of this material for biological application in a safe way.”

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Other authors of the paper include lead author Tarek Fadel, Michael Look, Peter Staffier, Gary Haller and Lisa Pfefferle, all of the Yale School of Engineering & Applied Science.

December 24, 2009

Introducing the one-molecule transistor

I’ve already introduced the one-atom transistor earlier this month. Now here’s new research offering a transistor created from a single molecule.

The release:

Scientists create world’s first molecular transistor

IMAGE: Engineers adjusted the voltage applied via gold contacts to a benzene molecule, allowing them to raise and lower the molecule’s energy states and demonstrate that it could be used exactly…

Click here for more information.

This release is available in Chinese.

New Haven, Conn.—A group of scientists has succeeded in creating the first transistor made from a single molecule. The team, which includes researchers from Yale University and the Gwangju Institute of Science and Technology in South Korea, published their findings in the December 24 issue of the journal Nature.

The team, including Mark Reed, the Harold Hodgkinson Professor of Engineering & Applied Science at Yale, showed that a benzene molecule attached to gold contacts could behave just like a silicon transistor.

The researchers were able to manipulate the molecule’s different energy states depending on the voltage they applied to it through the contacts. By manipulating the energy states, they were able to control the current passing through the molecule.

“It’s like rolling a ball up and over a hill, where the ball represents electrical current and the height of the hill represents the molecule’s different energy states,” Reed said. “We were able to adjust the height of the hill, allowing current to get through when it was low, and stopping the current when it was high.” In this way, the team was able to use the molecule in much the same way as regular transistors are used.

The work builds on previous research Reed did in the 1990s, which demonstrated that individual molecules could be trapped between electrical contacts. Since then, he and Takhee Lee, a former Yale postdoctoral associate and now a professor at the Gwangju Institute of Science and Technology, developed additional techniques over the years that allowed them to “see” what was happening at the molecular level.

Being able to fabricate the electrical contacts on such small scales, identifying the ideal molecules to use, and figuring out where to place them and how to connect them to the contacts were also key components of the discovery. “There were a lot of technological advances and understanding we built up over many years to make this happen,” Reed said.

There is a lot of interest in using molecules in computer circuits because traditional transistors are not feasible at such small scales. But Reed stressed that this is strictly a scientific breakthrough and that practical applications such as smaller and faster “molecular computers”—if possible at all—are many decades away.

“We’re not about to create the next generation of integrated circuits,” he said. “But after many years of work gearing up to this, we have fulfilled a decade-long quest and shown that molecules can act as transistors.”

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Other authors of the paper include Hyunwook Song and Yun Hee Jang (Gwangju Institute of Science and Technology); and Youngsang Kim and Heejun Jeong (Hanyang University).

Citation: 10.1038/nature08639

October 20, 2009

Are we still evolving?

Of course.

The release:

Are humans still evolving? Absolutely, says a new analysis of a long-term survey of human health

Durham, NC – Although advances in medical care have improved standards of living over time, humans aren’t entirely sheltered from the forces of natural selection, a new study shows.

“There is this idea that because medicine has been so good at reducing mortality rates, that means that natural selection is no longer operating in humans,” said Stephen Stearns of Yale University. A recent analysis by Stearns and colleagues turns this idea on its head. As part of a working group sponsored by the National Evolutionary Synthesis Center in Durham, NC, the team of researchers decided to find out if natural selection — a major driving force of evolution — is still at work in humans today. The result? Human evolution hasn’t ground to a halt. In fact, we’re likely to evolve at roughly the same rates as other living things, findings suggest.

Taking advantage of data collected as part of a 60-year study of more than 2000 North American women in the Framingham Heart Study, the researchers analyzed a handful of traits important to human health. By measuring the effects of these traits on the number of children the women had over their lifetime, the researchers were able to estimate the strength of selection and make short-term predictions about how each trait might evolve in the future. After adjusting for factors such as education and smoking, their models predict that the descendents of these women will be slightly shorter and heavier, will have lower blood pressure and cholesterol, will have their first child at a younger age, and will reach menopause later in life.

“The take-home message is that humans are currently evolving,” said Stearns. “Natural selection is still operating.”

The changes may be slow and gradual, but the predicted rates of change are no different from those observed elsewhere in nature, the researchers say. “The evolution that’s going on in the Framingham women is like average rates of evolution measured in other plants and animals,” said Stearns. “These results place humans in the medium-to-slow end of the range of rates observed for other living things,” he added. “But what that means is that humans aren’t special with respect to how fast they’re evolving. They’re kind of average.”

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Additional authors on the study were Sean Byars of Yale University, Douglas Ewbank of the University of Pennsylvania, and Diddahally Govindaraju of Boston University.

The team’s findings were published online in the October 19th issue of Proceedings of the National Academy of Sciences.

CITATION: Byars, S., D. Ewbank, et al. (2009). “Natural selection in a contemporary human population.” Proceedings of the National Academy of Sciences 106(42). doi: 10.1073_pnas.0906199106.

The National Evolutionary Synthesis Center (NESCent) is an NSF-funded collaborative research center operated by Duke University, the University of North Carolina at Chapel Hill, and North Carolina State University.

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