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Tuesday, February 3rd, 2015
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| 12:00a |
When logic meets rhetoric During the 2012 election season, Edward Schiappa closely watched the campaign in his longtime home of Minnesota, where voters were entertaining a measure called Amendment 1. A “yes” vote would have changed the state constitution to make marriage legal only between a man and a woman; a “no” vote would have been a move in favor of gay rights.
“Going into the 2012 election, I was not at all optimistic about the results,” says Schiappa, then a professor of communications at the University of Minnesota, who favored a “no” vote. After all, the “yes” campaign led in many polls late into the summer. But the momentum then shifted: The “no” side starting gaining traction, and on Election Day, Minnesota voters voted “no” by a 51-47 margin.
“I was watching the Minnesota campaign thinking, ‘They’re blowing it,’” Schiappa recalls of the amendment’s opponents. “But in fact they did exactly the right thing. They had a much stronger ground game, they enlisted a lot of religious leaders … and they reframed the debate [toward] family values, that this is promoting love and companionship and family. And history was made.”
Schiappa has a keen understanding of another factor behind the “no” vote on Amendment 1: mass media and popular culture. Nearly a decade earlier, in multiple papers, Schiappa and a pair of colleagues had been among the first scholars to present empirical evidence suggesting that television shows featuring gay characters, such as “Will & Grace” were creating more positive attitudes about gays in the minds of the general public. Indeed, they found, this change “was most pronounced for those with the least amount of social contact with lesbians and gay men.”
A decade before that, in the 1990s, few people could have foreseen that Schiappa would be studying contemporary mass media. He established his academic reputation as a scholar of ancient Greek rhetoric, writing three books on the subject. Schiappa’s breadth of knowledge and appetite for new types of inquiry are two reasons he is now serving as head of MIT’s section in Comparative Media Studies/Writing, having joined the Institute in 2013 as the John E. Burchard Professor.
To Schiappa, this feels like a natural evolution.
“Rhetoric has been understood primarily as about persuasion, and that is a huge topic,” he explains. “Ancient rhetoric was when thinkers first explored the relationship between language and thought, and the role of ‘reasoned speech’ in collective decision-making. Those issues are still central to communication studies today. … So for me, there was never a disconnect between the study of classical and contemporary rhetorical theory.”
Debating the future
Growing up in Manhattan, Kan., Schiappa knew he would end up in a classroom. He just didn’t know it would be at the university level.
“Starting in high school I knew I wanted to be a teacher, and as I worked my way through college I planned to be a high-school teacher and debate coach,” Schiappa explains.
But as he was finishing his undergraduate degree in 1980, Schiappa says, “I was offered a position to coach the debate team at Kansas State University. It took only a few months for me to realize I really enjoyed teaching college students, and I’ve never looked back.”
Schiappa enrolled in a master’s program at Northwestern University, which has a leading debate program, “thinking I would get a quick master’s degree, then return to K-State.” That isn’t quite what happened: As a graduate student, he “discovered how much I enjoyed research and writing.” He also happened to be fascinated by the Greek Sophists, pioneers of classical rhetoric — partly spurred by a bestseller from the 1970s, “Zen and the Art of Motorcycle Maintenance,” which discusses the Sophists.
After receiving his PhD from Northwestern in 1989, Schiappa taught at Kansas State and Purdue University before joining Minnesota in 1995. While much of his research at the time focused on Greek rhetoric, Schiappa’s interests also started shifting into the contemporary era. His methods have also evolved, to include quantitative audience measurement as a tool for understanding the effectiveness of mass-media communication.
“What I have tried to bring to the table is a mix of comparative methods that combines the best insights from both approaches,” Schiappa explains. “So we can analyze and critique individual shows like ‘Will & Grace,’ but also step back and talk with audiences and do surveys that can help us understand the important cultural work such a show does.”
The “parasocial contact hypothesis”
Schiappa’s mass-media studies are also interdisciplinary in nature. While studying “Will & Grace” and other shows, including “Six Feet Under” and “Queer Eye for the Straight Guy,” Schiappa and his colleagues formulated what they call the “parasocial contact hypothesis,” which suggests that media content can influence social attitudes, much as direct human interaction does.
The idea links a pair of ideas from psychology — Schiappa started college as a psychology major — known as “parasocial contact” and “contact hypothesis.” “I think it’s important for communication scholars to be aware of work that’s being done in other disciplines,” Schiappa says.
Schiappa says he enjoys teaching, and encourages students to work on research with him, when possible; one of his books was co-authored with a former student. “I’ve been teaching long enough now that it’s enormously satisfying to hear from students I’ve had, in some cases decades ago, [and] to know you positively influenced students,” Schiappa says.
And while Schiappa was content at Minnesota, he is enthused about the challenges of his still-new position at the Institute.
“It was a fortuitous coming together of my background and MIT’s needs,” he says. “I’m happy to be here.” | | 12:00a |
Waves in the deep Acoustic-gravity waves — a special type of sound wave that can cut through the deep ocean at the speed of sound — can be generated by underwater earthquakes, explosions, and landslides, as well as by surface waves and meteorites. A single one of these waves can stretch tens or hundreds of kilometers, and travel at depths of hundreds or thousands of meters below the ocean surface, transferring energy from the upper surface to the seafloor, and across the oceans. Acoustic-gravity waves often precede a tsunami or rogue wave — either of which can be devastating.
Now a new study by an MIT researcher suggests that these immense deep-ocean waves can rapidly transport millions of cubic meters of water, carrying salts, carbons, and other nutrients around the globe in a matter of hours.
Usama Kadri, a postdoc in MIT’s Department of Mechanical Engineering, tracked the theoretical movement of fluid caught up in an acoustic-gravity wave at various depths in the ocean, ranging from hundreds to thousands of meters below the surface. Based on his calculations, Kadri found that acoustic-gravity waves can push parcels significant distances, depending on their depth.
“Deep-water transport is so vital — not only to local marine ecosystems, but to our global ecosystem and environment — that a cut in such transport will ultimately result in the death of marine life, create regions of extreme water temperatures, and dramatically affect our climate,” says Kadri, who has published his results in the Journal of Geophysical Research: Oceans. “To sustain a healthier global ecosystem and environment, there is a need to increase awareness of acoustic-gravity waves and deep-water transport.”
Kadri adds that such awareness may help scientists devise early-warning systems for seaside communities and offshore facilities vulnerable to tsunamis or rogue waves — monster waves that can come on suddenly, with potentially devastating effects.
“Since acoustic-gravity waves are so much faster than tsunamis or rogue waves, successful recordings of … acoustic-gravity waves would enhance current warning systems dramatically, and improve detection by minutes to hours depending on the source location,” Kadri says, “either of which is sufficient to [save] many lives.”
Acoustics and gravity
A gravity wave is generated in a fluid or at the interface between fluids, and is governed by gravity. A common example is an ocean surface wave.
Acoustic waves, by contrast, propagate through longitudinal compression. For example, sound travels by vibrating and pushing against a fluid medium. Unlike in gravity waves, compressibility dominates acoustic waves, while the effect of gravity is negligible.
For those reasons, Kadri says, scientists have generally studied either sound waves in the ocean from a purely acoustic perspective, or surface waves in an incompressible ocean.
Drifting with the wave
Kadri modeled the behavior of acoustic-gravity waves in the deep ocean by first considering the propagation of waves in an ideal, compressible ocean, where water volume changes slightly in response to pressure changes. In a two-dimensional model, he calculated the movement of fluid caused by a traveling acoustic-gravity wave at various depths in the ocean.
Kadri’s equations showed that acoustic-gravity waves may propagate throughout the ocean, up to thousands of meters deep, even traveling along the seafloor. He then looked into whether acoustic-gravity waves may cause water to drift long distances, or if they simply recirculate them back to their original location.
Kadri worked the equation out for acoustic-gravity waves at various depths in the deep ocean, and found that these waves can transport water at a velocity of a few centimeters per second. Such waves, Kadri estimates, can therefore transport millions of cubic meters of deep water per second.
According to these results, acoustic-gravity waves may be “major players,” Kadri says, in transporting water and producing currents in the deep ocean. Such waves may be instrumental in carrying plankton, algae, and bacteria across the oceans, as well as in delivering essential nutrients to sedentary marine organisms.
Knowing the properties of acoustic-gravity waves may also help researchers develop early-warning systems for potentially devastating ocean events, such as tsunamis and rogue waves. Toward that end, Kadri is continuing his work to develop predictive computations that can analyze acoustic signals for fast-traveling acoustic-gravity waves — a precursor to tsunamis.
Jerry Smith, a research oceanographer at the University of California at San Diego, says a striking contribution from Kadri’s research is the finding that surface waves have an effect on deep-ocean waves.
“The most significant finding in this particular paper is the contribution to deep-ocean transport,” says Smith, who was not involved in the research. “This has not been appreciated before. Since these acoustic-gravity waves can be generated by nonlinear interactions of ordinary wind-waves, the contribution to deep transport could be ubiquitous.” | | 10:58a |
Langer wins Queen Elizabeth Prize for Engineering Robert Langer, the David H. Koch Institute Professor at MIT, has been named the winner of this year's Queen Elizabeth Prize for Engineering for his revolutionary advances and leadership in engineering at the interface of chemistry and medicine. The award credits Langer with improving more than 2 billion lives worldwide through the disease treatments created in his lab. Langer will receive the prize from Queen Elizabeth II in a ceremony later this year.
"Bold, down to earth, and incredibly creative, Bob Langer represents the very best of MIT: a daring inventor, a brilliant entrepreneur, and an admired and beloved educator," MIT President L. Rafael Reif says. "His creativity has changed the world not only through his own innovations but through the hundreds of exceptional engineers who have begun their careers in his lab. If engineering is the art of transforming knowledge into progress, then the Queen Elizabeth Prize for Engineering could go to no one who deserves it more than Bob."
Langer, who holds appointments in MIT's departments of chemical engineering and biological engineering, and at the Institute for Medical Engineering and Science and the Koch Institute for Integrative Cancer Research, is cited as “the first person to engineer polymers to control the delivery of large molecular weight drugs for the treatment of diseases such as cancer and mental illness.”
The Queen Elizabeth Prize for Engineering is a global £1 million prize that celebrates engineers whose innovations have been of global benefit to humanity. The objective of the prize is to raise the public profile of engineering and to inspire young people to become engineers.
“The number one thing we look at is, ‘Can we relieve suffering?’” Langer said in an interview with the BBC earlier today. “That’s the thing that drives me, and drives many who do this work — to relieve suffering and improve life."
"A prize like this is intended to celebrate engineering,” Langer added. “Hopefully young people will read about it and think it’s a great career. In the end, a culture gets what it celebrates.”
Langer received his bachelor's degree in chemical engineering from Cornell University, and earned his ScD in chemical engineering from MIT. He has written more than 1,175 research papers — which have made him the world's most cited engineering researcher — and holds approximately 800 issued and pending patents worldwide, which have been licensed or sublicensed to hundreds of pharmaceutical, chemical, biotechnology, and medical device companies.
In 1989, Langer was elected to the Institute of Medicine of the National Academy of Sciences, and in 1992 he was elected to both the National Academy of Engineering and the National Academy of Sciences. He served as a member of the Food and Drug Administration’s Science Board from 1995 to 2002, and as the board's chairman from 1999 to 2002. He has received more than 200 awards, including the National Medal of Science in 2006, the Millennium Prize in 2008, the Priestley Medal in 2012, the National Medal of Technology and Innovation in 2012, the Charles Stark Draper Prize, and the Gairdner Foundation International Award.
In the popular media, both BioWorld and Forbes have named Langer as one of the world's 25 most important individuals in biotechnology, in 1990 and 1999, respectively. In 2001, both Time and CNN named Langer as among the 100 most important people in America, and as one of the top Americans in science or medicine. In 2002, Discover named him as one of the 20 most important people in biotechnology, and Forbes selected him as one of the 15 innovators worldwide who will reinvent our future. | | 2:06p |
Ioannis Yannas to be inducted into the National Inventors Hall of Fame Ioannis V. Yannas, professor of polymer science and engineering in the MIT Department of Mechanical Engineering, was recognized as one of the highest achievers in his field last week when the National Inventors Hall of Fame announced it would be inducting him at their 2015 ceremony this May. With this honor, which recognizes his invention of what has become known as "artificial skin," Yannas joins a small group of approximately 500 renowned Hall-of-Fame inventors.
Until just a few decades ago, human and pig skin were often used in burn treatments, but were commonly rejected by the body’s immune system. Immune suppressants also left patients vulnerable to infection. What's more, replacement skin often suffered from dehydration; at the time, no one had yet found a way of rebuilding skin that could maintain a normal moisture level.
In 1969, Yannas was studying the physics of collagen and the theory of viscoelasticity in polymers at MIT when he approached surgeon John F. Burke to collaborate on the problem. As chief of staff at Shriner's Burns Institute in Boston, Burke had already made significant strides in burn treatment, but was still missing a piece of the puzzle.
“He wanted something to keep the bacteria out and keep the moisture in,” says Yannas. “So I started to work on synthesizing a dressing for wounds that would speed up their closure, minimizing patients’ risk of infection and dehydration.”
Regenerating a new organ
As it turned out, Yannas’ artificial skin did more than just block infection and retain moisture — it actually helped to regenerate the skin.
At first, however, Yannas and Burke thought they had failed miserably. After several unsuccessful attempts to develop a dressing that would speed up the healing process, one of their membranes finally had an impact on the timeframe of healing — by significantly delaying it rather than speeding it up as expected. Yannas was crushed by this development.
“At that point,” he says, “I began to think that our project to help burn victims was over. Nevertheless, I could not stop myself from trying to understand what had gone wrong. I mounted an effort to understand why the collagen membrane had delayed closure. I spent two nights studying tissue samples from the various experiments. Epiphany occurred when I noticed that the dressing that had delayed closure had not produced a scar.”
In its place, says Yannas, was a strange kind of tissue he had never seen inside these wounds. It was dermis, the layer of normal skin underneath the epidermis.
The trick, he discovered, had been adding a synthetic layer of silicone on top of a layer of tissue-like “scaffolding” — a combination of molecular material from cow tendons and shark cartilage that imitated the matrix in tissues. The synthetic layer on top protects the skin from bacteria and infection and keeps the moisture in, while the organic layer below acts as a template on which new healthy skin cells and matrix can grow. This was remarkable because it is well known that, once injured, the dermis never grows back by itself in adults; instead wounds fill up with scar.
“For years, we did not understand the impact that this discovery would have,” Yannas says. “We simply thought it was a new treatment for burn victims. Eventually, it became clear that we were regenerating a new organ.”
Groundbreaking model
Harvard Medical School Professor Myron Spector, a close collaborator of Yannas’s for more than 20 years and an expert in biomaterials and tissue engineering, says, “In addition to resulting in a highly successful treatment for a broad spectrum of skin injuries and diseases, which alone would have been a life’s achievement, the research that Professor Yannas has conducted over the past three decades in developing a collagen-based regeneration template has led to many significant advancements. He has proved the validity of certain principles guiding regeneration and has provided a groundbreaking model for medical-device development and what is now termed ‘translational research.’"
Yannas’ regeneration principles and the collagen scaffolding he invented have generated at least three start-ups founded by prior students, postdoctoral fellows, and residents, with products to treat defects in skin, peripheral nerves, the meniscus of the knee, and articular cartilage.
Yannas is a member of the National Academy of Sciences (Institute of Medicine) and the American Association for the Advancement of Science; a founding fellow of the American Institute of Medical and Biological Engineering; and a charter member of the Biomedical Engineering Society, among others. He has previously won numerous awards, including the Doolittle Award of the American Chemical Society and the Clemson Award for Applied Science and Engineering from the Society of Biomaterials.
Yannas will be inducted along with 13 others, including John Burke and fellow MIT graduate Edith Clarke, at the 2015 National Inventors Hall of Fame induction ceremony in May. For more information, visit invent.org. | | 7:00p |
Splash down Farmers have long noted a correlation between rainstorms and disease outbreaks among plants. Fungal parasites known as “rust” can grow particularly rampant following rain events, eating away at the leaves of wheat and potentially depleting crop harvests.
While historical weather records suggest that rainfall may scatter rust and other pathogens throughout a plant population, the mechanism by which this occurs has not been explored, until now.
In a paper published in the Journal of the Royal Society Interface, a team from MIT and the University of Liege, in Belgium, presents high-speed images of raindrops splashing down on a variety of leaves coated with contaminated fluid. As seen in high resolution, these raindrops can act as a dispersing agent, in some instances catapulting contaminated droplets far from their leaf source.
The researchers observed characteristic patterns of dispersal, and found that the range of dispersal depends on a plant’s mechanical properties — particularly its compliance, or flexibility.
Lydia Bourouiba, the Esther and Harold E. Edgerton Career Development Assistant Professor of Civil and Environmental Engineering at MIT, says understanding the relationship between a plant’s mechanical properties and the spread of disease may help farmers plant more disease-resistant fields.
“We can start thinking of how to smartly reinvent polyculture, where you have alternating species of plants with complimentary mechanical properties at various stages of their growth,” says Bourouiba, who is a senior author of the paper. “Polyculture is an old concept if you look at native cultures, but this is one way to scientifically show that by alternating plants in one field, you can mechanically and naturally reduce the range of transmission of a pathogen during rainfall.”
Tracking the fluid dynamics of outbreak
In their paper, Bourouiba and Tristan Gilet, of the University of Liege, first addressed a widely held assumption: that pathogens coat leaves in a thin film.
The team ran experiments with dozens of types of common foliage, including ivy, bamboo, peppermint, and banana leaves. They conducted hundreds of experiments for each type of foliage, using 30 examples of real plant foliage and 12 artificially engineered materials. In initial trials, the researchers simulated rainfall by running water through a container pricked with tiny holes. The container was suspended several meters in the air, high enough for drops to reach terminal velocity — the speed of an actual raindrop upon impact.
The researchers captured the sequence of events as raindrops hit each leaf, using high-speed videography at 1,000 frames per second. From these images, Bourouiba and Gilet noted that as water fell, leaves were unable to support a thin film, instead forming drops on their surface. The team concluded that pathogens, in turn, must rest as droplets — not film — on a leaf’s surface.
“That can initially seem like a small difference, but when you look at the fluid dynamics of the fragmentation and resulting range of contamination around an infected leaf, it actually changes a lot of the dynamics in terms of the mechanism by which [pathogens] are emitted,” Bourouiba says.
To observe such dynamic differences, the team first simulated rainfall over a flat surface coated with a thin film. When a droplet hit this surface, it launched a crown-like spray of the filmy substance, though most of the spray stayed within the general vicinity. In contrast, the team found that raindrops that splashed onto leaves covered with droplets, rather than a film, launched these drops far and wide.
From crescent moons to catapults
To examine the effect of raindrops on surface drops in more detail, the researchers performed a separate round of experiments, in which they dotted leaves with dyed water — a stand-in for pathogens. They then created a setup to mimic one single drop of rain, using lasers to delicately calibrate where on the leaf a drop would fall.
From these experiments, Bourouiba and Gilet observed two main patterns of dispersal: a crescent-moon configuration, in which a raindrop flattens upon impact, sliding underneath the dyed droplet and launching it up in an arc, similar to the shape of a crescent moon; and inertial detachment, where a raindrop never actually touches a dyed droplet, but instead pushes the leaf down, causing the dyed droplet to slide downwards, then catapult out — a consequence of the inertia of the leaf as it bounces back up.
After capturing hundreds of raindrop impacts on a range of leaf types, Bourouiba and Gilet realized that whether a droplet assumes a crescent-moon or inertial detachment configuration depends mainly on one property: a leaf’s compliance, or flexibility. They found that in general, the floppier a leaf, the less effective it was at launching a wide arc, or crescent-moon of fluid. However, at a certain flexibility, the crescent-moon pattern morphed into one of inertial detachment, in which fluid, in the form of larger drops than what the crescent moon can produce, was flung further from the leaf.
From their observations, the researchers developed a theoretical model that quantitatively captures the relationship between a leaf’s flexibility, the fragmentation of the fluid, and its resulting pattern of raindrop-induced dispersal. The model, Bourouiba says, may eventually help farmers design fields of alternating crops. While the practice of polyculture has traditionally relied on reducing the spread of disease by alternating plants with varying resistance to pathogens, Bourouiba says the intrinsic mechanical properties — not biological immunology — of plants could themselves help contain the spread of disease.
“If this were done optimally, ideally you could completely cut the spread to just one neighboring plant, and it would die there,” Bourouiba says. “One plant could play the role of a shield, and get contaminated, but its mechanical properties would not be sufficient to project the pathogen to the next plant. So you could start reducing the efficacy of spread in one species, while still using agricultural space effectively.”
Don Aylor, an emeritus scientist of plant pathology and ecology at the Connecticut Agricultural Experiment Station in New Haven, Conn., says Bourouiba’s results may be particularly useful in tamping down disease in small plant populations.
“This could help set separation distances for crops of small plants, such as strawberries, that are usually planted in close proximity,” says Aylor, who did not contribute to the study. “The farmer would also have to consider the effect of splashing on plastic mulch often used in such crops. In summary, this is a nice study and introduces some findings that are certainly worth following up on.” |
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