David Kirkpatrick

September 10, 2010

Graphene could speed up DNA sequencing

I’ve blogged on this topic before (and on this very news bit in the second post from the link), but this just reiterates the versatility of graphene and why the material has so many scientists, researchers and entrepreneurs so excited.

From the second link:

By drilling a tiny pore just a few-nanometers in diameter, called a , in the graphene membrane, they were able to measure exchange of ions through the pore and demonstrated that a long  can be pulled through the graphene nanopore just as a thread is pulled through the eye of a needle.

“By measuring the flow of ions passing through a nanopore drilled in graphene we have demonstrated that the thickness of graphene immersed in liquid is less then 1 nm thick, or many times thinner than the very thin membrane which separates a single animal or human cell from its surrounding environment,” says lead author Slaven Garaj, a Research Associate in the Department of Physics at Harvard. “This makes graphene the thinnest membrane able to separate two liquid compartments from each other. The thickness of the membrane was determined by its interaction with water molecules and ions.”

August 20, 2010

Measuring worker productivity — here comes the science

Interesting research on worker productivity, particularly on the question of why workers in low-paying, low supervision jobs don’t simply complete the bare minimum of work to get by.

From the link:

One line of thinking focuses on the relationship between the workers and their employer, which can be influenced by contracts set out in writing and by personal relationships between workers and their managers.

That suggests that one way for an employer to improve productivity would be to perfect its employment contracts.

Another line of thinking is that peer pressure plays an important role. The people around you may affect the way you work. For example, good workers, leading by example, might raise the quality of everybody’s work. On the other hand, bad apples may make the good ones rotten.

But working out which of these effects wins out is hard. Peer pressure is hard to quantify and the various results in this area are somewhat contradictory, suggesting that they may depend on the environment too

But a new tool is emerging that can help, according to John Horton at Harvard University who says the recent development of online marketplaces, in which people can buy and sell services over the web, provides a fascinating laboratory in which to test these ideas.

Today he publishes the results of a set of experiments that reveal some of the ways in which peer pressure may influence productivity.

Hit the link up in the intro graf for the results of his study. One interesting aspect is Horton used Amazon’s Mechanical Turk service as his “laboratory.”

August 19, 2010

Graphene and DNA sequencing

News on potential applications of graphene is always interesting, but I’ll have to admit I’d like see more actual market-ready solutions. This news is both intriguing and promising, but the nut graf contains those dreaded words, “could help (insert the gist of any story here).” It’ll be a pretty exciting day when I blog about something that will help, instead of could help with graphene as the key helping element.

From the second link:

Layers of graphene that are only as thick as an atom could help make human DNA sequencing faster and cheaper. Harvard University and MIT researchers have shown that sheets of graphene could be a big improvement over membranes that are currently used for nanopore sequencing–a technique that promises to speed up and simplify the sequencing of long strands of DNA.

And:

The researchers create their membrane by placing a graphene flake over a 200-nanometer-wide opening in the middle of a silicon-nitride surface. Then they drill a few pores, just nanometers wide, in the graphene with an electron beam. The membrane is finally immersed in a salt solution that’s in contact with silver electrodes. The researchers observed dips in the current when a DNA strand passed through the pore, showing that the method could eventually be used to identify DNA bases.

June 9, 2010

H+ Summit streamed live this weekend

Filed under: Business, et.al., Media, Politics, Science, Technology — Tags: , , , , , — David Kirkpatrick @ 2:32 pm

Via KurzweilAI.net — Very cool news. Not sure if I’m going to be able to participate, but having the option to do so is good to know.

H+ Summit @ Harvard this weekend to be streamed live, free
KurzweilAI.net, June 9, 2010

The H+ Summit at Harvard this coming weekend will be streamed live, starting June 12 at 9 AM, according to David Orban, Chairman of Humanity+.

“Anybody can connect free, and ask questions using the #hplussummit hashtag. Moderators will monitor the Twitter firehose and choose the best questions for speakers during Q&A sessions,” he said.

It will stream at 24 fps in H.264 MPEG-4 for iPhone and iPad compatibility (as well as browsers) — with unlimited capacity, Orban said. Tip: download the high-res presentation files in advance (some are already up).

If you miss some of it, all of the more than 50 speakers are being recorded at 1080p 60fps HD video, to be released online under a Creative Commons Attribution license, starting in the weeks following the conference.

The H+ Summit is a two day event that explores how humanity will be radically changed by technology in the near futureVisionary speakers will explore the potential of technology to modify your body, mindlife, and world.

April 18, 2010

Carbon nanotubes and new states of matter

Now this is some fascinating research on carbon nanotube properties.

From the link:

“For the first time, fields of study relating both to cold atoms and to the nanoscale have intersected,” Lene Vestergaard Hau tells PhysOrg.com. “Even though both have been active areas of research, cold atoms have not been brought together with nanoscale structures at the single nanometer level. This is a totally new system.”

Hau is the Mallinckrodt Professor of Physics and Applied Physics at Harvard University. Along with colleague J.A. Golovchenko, and graduate students Anne Goodsell and Trygve Ristroph, who are in her lab at Harvard, Hau was able to set up an experiment that allows for the observation of capture and field ionization of cold atoms. Their work can be found in : “Field  of Cold Atoms near the Wall of a Single Carbon Nanotube.”

And:

“When the electron is pulled in, it goes through a tunneling process,” Hau explains. “It has to go through areas that are classically forbidden. The process is quantum mechanical. We can observe the interaction of the atom and the nanotube as the electron is trying to tunnel, and this offers us a chance to peek at some of the interesting dynamics that happen at the nanoscale.”

Another possibility is that this combination of cold atoms with  could lead to new states of matter. “Since we now know how to suck atoms into orbit at such high spin rates, it could lead to a new state of cold-atomic matter that could be super interesting to study,” Hau points out.

Practical applications?:

Practically, this new system has potential as well. “We could make very sensitive detectors,” Hau says. “Things like ‘atom sniffers’ that detect trace gases could be an application for this work. Additionally, the possibility of single nanometer precision means super high spatial resolution. This system could be used in interferometers — interferometers built on a single chip and based on , which would be of importance for navigation, for example.”

For the raw material, here’s the release the linked article sprung from.

February 15, 2010

A little nano bling …

… may lead to some serious nanotech applications in medicine, data protection and supercomputing.

The release:

Digging deep into diamonds, applied physicists advance quantum science and technology

Diamond nanowire device could lead to new class of diamond nanomaterials suitable for quantum cryptography, quantum computing, and magnetic field imaging

IMAGE: A diamond-based nanowire device. Researchers used a top-down nanofabrication technique to embed color centers into a variety of machined structures. By creating large device arrays rather than just “one-of-a-kind ” designs,…

Click here for more information.

CAMBRIDGE, Mass., By creating diamond-based nanowire devices, a team at Harvard has taken another step towards making applications based on quantum science and technology possible.

The new device offers a bright, stable source of single photons at room temperature, an essential element in making fast and secure computing with light practical.

The finding could lead to a new class of nanostructured diamond devices suitable for quantum communication and computing, as well as advance areas ranging from biological and chemical sensing to scientific imaging.

Published in the February 14th issue of Nature Nanotechnology, researchers led by Marko Loncar, Assistant Professor of Electrical Engineering at the Harvard School of Engineering and Applied Sciences (SEAS), found that the performance of a single photon source based on a light emitting defect (color center) in diamond could be improved by nanostructuring the diamond and embedding the defect within a diamond nanowire.

Scientists, in fact, first began exploiting the properties of natural diamonds after learning how to manipulate the electron spin, or intrinsic angular momentum, associated with the nitrogen vacancy (NV) color center of the gem. The quantum (qubit) state can be initialized and measured using light.

The color center “communicates” by emitting and absorbing photons. The flow of photons emitted from the color center provides a means to carry the resulting information, making the control, capture, and storage of photons essential for any kind of practical communication or computation. Gathering photons efficiently, however, is difficult since color-centers are embedded deep inside the diamond.

“This presents a major problem if you want to interface a color center and integrate it into real-world applications,” explains Loncar. “What was missing was an interface that connects the nano-world of a color center with macro-world of optical fibers and lenses.”

The diamond nanowire device offers a solution, providing a natural and efficient interface to probe an individual color center, making it brighter and increasing its sensitivity. The resulting enhanced optical properties increases photon collection by nearly a factor of ten relative to natural diamond devices.

“Our nanowire device can channel the photons that are emitted and direct them in a convenient way,” says lead-author Tom Babinec, a graduate student at SEAS.

Further, the diamond nanowire is designed to overcome hurdles that have challenged other state-of-the-art systems—such as those based on fluorescent dye molecules, quantum dots, and carbon nanotubes—as the device can be readily replicated and integrated with a variety of nano-machined structures.

The researchers used a top-down nanofabrication technique to embed color centers into a variety of machined structures. By creating large device arrays rather than just “one-of-a-kind” designs, the realization of quantum networks and systems, which require the integration and manipulation of many devices in parallel, is more likely.

“We consider this an important step and enabling technology towards more practical optical systems based on this exciting material platform,” says Loncar. “Starting with these synthetic, nanostructured diamond samples, we can start dreaming about the diamond-based devices and systems that could one day lead to applications in quantum science and technology as well as in sensing and imaging.”

###

Loncar and Babinec’s co-authors included research scholar Birgit Hausmann, graduate student Yinan Zhang, and postdoctoral student Mughees Khan, all at SEAS; graduate student Jero Maze in the Department of Physics at Harvard; and faculty member Phil R. Hemmer at Texas A&M University.

The researchers acknowledge the following support: Nanoscale Interdisciplinary Research Team (NIRT) grant from National Science Foundation (NSF), the NSF-funded Nanoscale Science and Engineering Center at Harvard (NSEC); the Defense Advanced Research Projects Agency (DARPA); and a National Defense Science and Engineering Graduate Fellowship and National Science Foundation Graduate Fellowship. All devices have been fabricated at the Center for Nanoscale Systems (CNS) at Harvard.

June 5, 2009

The “ick” factor and conservatives

One explanation given for opposition to same-sex marriage is the so-called “ick” factor. That is revulsion against the very idea of homosexuality by heterosexuals.

Take this for what it’s worth because it smells a lot like a solution in search of problem, but here’s research from Cornell connecting that very response with a group largely against same-sex marriage — political conservatives.

Food for thought if nothing else.

The release (yeah, I know I said the release dump was over with the last post):

Easily grossed out? You’re more likely a conservative,
says Cornell psychologist

Are you someone who squirms when confronted with slime, shudders at stickiness or gets grossed out by gore? Do crawly insects make you cringe or dead bodies make you blanch?

If so, chances are you’re more conservative — politically, and especially in your attitudes toward gays and lesbians — than your less-squeamish counterparts, according to two Cornell studies.

The results, said study leader David Pizarro, Cornell assistant professor of psychology, raise questions about the role of disgust — an emotion that likely evolved in humans to keep them safe from potentially hazardous or disease-carrying environments — in contemporary judgments of morality and purity.

In the first study, published in the journal Cognition & Emotion (Vol.23: No.4), Pizarro and co-authors Yoel Inbar of Harvard University’s Kennedy School of Government and Paul Bloom of Yale University surveyed 181 U.S. adults from politically mixed “swing states.” They subjected these adults to two indexes: the Disgust Sensitivity Scale (DSS), which offers various scenarios to assess disgust sensitivity, and a political ideology scale. From this they found a correlation between being more easily disgusted and political conservatism.

To test whether disgust sensitivity is linked to specific conservative attitudes, the researchers then surveyed 91 Cornell undergraduates with the DSS, as well as with questions about their positions on issues including gay marriage, abortion, gun control, labor unions, tax cuts and affirmative action.

Participants who rated higher in disgust sensitivity were more likely to oppose gay marriage and abortion, issues that are related to notions of morality or purity. The researchers also found a weak correlation between disgust sensitivity and support for tax cuts, but no link between disgust sensitivity and the other issues.

And in a separate study in the current issue of the journal Emotion (Vol.9: No.3), Pizarro and colleagues found a link between higher disgust sensitivity and disapproval of gays and lesbians. For this study, the researchers used implicit measures (measures that have been shown to assess attitudes people may be unwilling to report explicitly; or that they may not even know they possess).

Liberals and conservatives disagree about whether disgust has a valid place in making moral judgments, Pizarro noted. Conservatives have argued that there is inherent wisdom in repugnance; that feeling disgusted about something — gay sex between consenting adults, for example — is cause enough to judge it wrong or immoral, even lacking a concrete reason. Liberals tend to disagree, and are more likely to base judgments on whether an action or a thing causes actual harm.

Studying the link between disgust and moral judgment could help explain the strong differences in people’s moral opinions, Pizarro said; and it could offer strategies for persuading some to change their views.

“People have pointed out for a long time that a lot of our moral values seem driven by emotion, and in particular, disgust appears to be one of those emotions that seems to be recruited for moral judgments,” said Pizarro.

That can have tragic effects — as in cases throughout history where minorities have been victims of discrimination by groups that perceived them as having disgusting characteristics.

The research speaks to a need for caution when forming moral judgments, Pizarro added. “Disgust really is about protecting yourself from disease; it didn’t really evolve for the purpose of human morality,” he said. “It clearly has become central to morality, but because of its origins in contamination and avoidance, we should be wary about its influences.”

The studies were funded by Cornell.

 

##

April 23, 2009

Nanoantennas

Sounds like some nanotech with potential.

The release:

Bridging the gap in nanoantennas

IMAGE: The bottom line depicts the topography, whereas the upper line plots the scanned near-field images. Figure a shows a metal nanorod that can be considered the most simple dipole antenna….

Click here for more information. 

In a recent publication in Nature Photonics, a joint team of researchers at CIC nanoGUNE, Donostia International Physics Center DIPC, Centro de Física de Materiales of CSIC/UPV-EHU in San Sebastian (Spain), Harvard University (USA) and the Max Planck Institute of Biochemistry in Munich (Germany) reports an innovative method for controlling light on the nanoscale by adopting tuning concepts from radio-frequency technology. The method opens the door for targeted design of antenna-based applications including highly sensitive biosensors and extremely fast photodetectors, which could play an important role in future biomedical diagnostics and information processing.

An antenna is a device designed to transmit or receive electromagnetic waves. Radio frequency antennas find wide use in systems such as radio and television broadcasting, point-to-point radio communication, wireless LAN, radar, and space exploration. In turn, an optical antenna is a device which acts as an effective receiver and transmitter of visible or infrared light. It has the ability to concentrate (focus) light to tiny spots of nanometer-scale dimensions, which is several orders of magnitude smaller than what conventional lenses can achieve. Tiny objects such as molecules or semiconductors that are placed into these so-called “hot spots” of the antenna can efficiently interact with light. Therefore optical antennas boost single molecule spectroscopy or signal-to-noise in detector applications.

In their experiments the researchers studied a special type of infrared antennas, featuring a very narrow gap at the center. These so called gap-antennas generate a very intense “hot spot” inside the gap, allowing for highly efficient nano-focusing of light. To study how the presence of matter inside the gap (the “load”) affects the antenna behavior, the researchers fabricated small metal bridges inside the gap (Figure b). They mapped the near-field oscillations of the different antennas with a modified version of the scattering-type near-field microscope that the Max Planck and nanoGUNE researchers had pioneered over the last decade. For this work, they chose dielectric tips and operated in transmission mode, allowing for imaging local antenna fields in details as small as 50 nm without disturbing the antenna. “By monitoring the near-field oscillations of the different antennas with our novel near-field microscope, we were able to directly visualize how matter inside the gap affects the antenna response. The effect could find interesting applications for tuning of optical antennas” says Rainer Hillenbrand leader of the Nanooptics group at the newly established research institute CIC nanoGUNE Consolider.

The nanooptics group from DIPC and CSIC-UPV/EHU led by Javier Aizpurua in San Sebastián fully confirmed and helped to understand the experimental results by means of full electrodynamic calculations. The calculated maps of the antenna fields are in good agreement with the experimentally observed images. The simulations add deep insights into the dependence of the antenna modes on the bridging, thus confirming the validity and robustness of the “loading” concept to manipulate and control nanoscale local fields in optics.

Furthermore, the researchers applied the well developed radio–frequency antenna design concepts to visible and infrared frequencies, and explained the behavior of the loaded antennas within the framework of optical circuit theory. A simple circuit model showed remarkable agreement with the results of the numerical calculations of the optical resonances. “By extending circuit theory to visible and infrared frequencies, the design of novel photonic devices and detectors will become more efficient. This bridges the gap between these two disciplines” says Javier Aizpurua.

With this work, the researches provide first experimental evidence that the local antenna fields can be controlled by gap-loading. This opens the door for designing near-field patterns in the nanoscale by load manipulation, without the need to change antenna length, which could be highly valuable for the development of compact and integrated nanophotonic devices.

 

###

September 29, 2008

Testosterone linked to financial risk-taking

Not sure what this says about the current situation, but it sure is interesting.

The release:

Financial risk-taking behavior is associated with higher testosterone levels

Males with testosterone levels above the mean invest more during a risky investment game

CAMBRIDGE, Mass., September 29, 2008 – Higher levels of testosterone are correlated with financial risk-taking behavior, according to a new study in which men’s testosterone levels were assessed before participation in an investment game. The findings help to shed light on the evolutionary function and biological origins of risk taking.

The study was jointly led by Anna Dreber, of the Program in Evolutionary Dynamics at Harvard University and the Stockholm School of Economics, and Coren Apicella, of Harvard’s Department of Anthropology. The results are available online in Evolution and Human Behavior.

“These findings help us to understand the motivations for risk-taking behavior, which is a major component of economic theory,” says Dreber. “Risk preferences are one of the most important preferences in economics, and yet no one knows why they differ between men and women, why they change over age, or what makes men trade more in the financial market.”

Previous studies have shown that on average, men are more likely than women to take risks, and the researchers theorized that these differences could be explained by the role of testosterone. Another recent study also demonstrated that stock market traders experienced greater profits on days their testosterone was above its median level. However, this is the first study to directly examine the relationship between testosterone and financial risk-taking.

“Although our findings do not address causality, we believe that testosterone may influence how individuals make risky financial decisions,” says Apicella.

In the study, saliva samples were taken from 98 males, ages 18 to 23, who were mostly Harvard students. The samples were taken before participation in the investment game, so the researchers were certain that testosterone levels were not elevated as a result of the game. The researchers also assessed facial masculinity, associated with testosterone levels at puberty.

All of the participants were given $250, and were asked to choose an amount between $0 and $250 to invest. The participants kept the money that was not invested. A coin toss determined the investment’s outcome, and if the participant lost the coin toss, the money allocated to the investment was lost. However, if the coin toss was won, the participant would receive two and a half times the amount of their investment. At the end of the study, one person was selected by lottery to receive the cash amount of their investment, which created a monetary incentive for the participants.

The researchers found that a man whose testosterone levels were more than one standard deviation above the mean invested 12 percent more than the average man into the risky investment. A man with a facial masculinity score of one standard deviation higher than the mean invested 6 percent more than the average man.

The findings may help to explain the biological foundation of why some people are more inclined towards risk-taking than others.

“Financial risk might be comparable to other risky male behaviors associated with reproduction,” says Apicella. “Men may be more willing to take financial risks because the payoffs, in terms of attracting mates, could be higher for them. This is because women value wealth more than men when choosing for a mate.”

Further research will examine changes in testosterone levels in response to financial wins and losses.

“This will give us some insight into how changes in the market affect hormones, and in turn, affect decision-making,” says Apicella.

Finally, the researchers are also exploring the role of genetics in explaining risk preferences.

“Maybe we will be able to predict who becomes a trader,” says Dreber.

 

###

 

Apicella and Dreber’s co-authors were Benjamin Campbell of the University of Wisconsin, Milwaukee; Peter B. Gray of the University of Nevada, Las Vegas; Moshe Hoffman of the University of Chicago; and Anthony C. Little of the University of Stirling, Scotland. The research was funded by the Jan Wallander and Tom Hedelius Foundation.

September 26, 2008

Stem cells from adult cells

I’m for stem cell research of all stripes, but it is encouraging that research is ongoing beyond just embryonic stem cells such as this application using adult cells.

This is good medical news. But no reason to not lift the asinine theocratic ban on US government support of embryonic stem cell research.

From the link:

Last year, researchers announcedone of the most promising methods yet for creating ethically neutral stem cells: reprogramming adult human cells to act like embryonic stem cells. This involved using four transcription factor proteins to turn specific genes on and off. But the resulting cells, called induced pluripotent stem (iPS) cells for their ability to develop into just about any tissue, have one huge flaw. They’re made with a virus that embeds itself into the cells’ DNA and, over time, can induce cancer. Now, scientists at Harvard University have found a way to effect the same reprogramming without using a harmful virus–a method that paves the way for tissue transplants made from a patient’s own cells.

June 27, 2008

Nanowire circuits and tracking asteroids

From KurzweilAI.net, the House passed a bill to begin tracking potential Earth-strike asteroids, and a new low-cost, high-volume method of integrating nanowires onto silicon has been developed.

House passes bill mandating a plan for asteroid warning and deflection
KurzweilAI.net, June 27, 2008

In recently passed H.R.6063, The U.S. House of Representatives would direct the NASA Administrator to develop plans for a low-cost spacemission to rendezvous with the Apophis asteroid and attach a tracking device (subject to Senate approval).

The Apophis is expected to pass at a distance from Earth that is closer than geostationary satellites in 2029.

The bill would also require the Director of the White House’s Office of Science and TechnologyPolicy (OSTP) to develop a policy within two years for notifying Federal agencies and relevant emergency response institutions of an impending near-Earth objectthreat. And the OSTP would be required to recommend a Federal agency (or agencies) to be responsible for protecting the Nation from any near-Earth object anticipated to collide with Earth, and for implementing a deflection campaign.

 

Researchers develop new technique for fabricating nanowire circuits
Nanowerk News, June 26, 2008

Scientists at Harvard University and German universities of Jena, Gottingen, and Bremen have developed a reproducible, high-volume, low-cost fabrication methodfor integrating nanowire devices directly onto silicon.

The method incorporates spin-on glass technology, used in silicon integrated circuits manufacturing, and photolithography, transferring a circuit pattern onto a substrate with light. These devices can then function as light-emitting diodes, with the color of light determined by the type of semiconductor nanowire used.

Because nanowires can be made of materials commonly used in electronics and photonics, they hold great promise for integrating efficient light emitters, and could lead to the development of a completely new class of integrated circuits, such as large arrays of ultra-small nanoscale lasers that could be designed as high-density optical interconnects or used for on-chip chemical sensing.

 
Read Original Article>>

The Silver is the New Black Theme. Blog at WordPress.com.

Follow

Get every new post delivered to your Inbox.

Join 25 other followers