Wednesday, February 10th, 2016

Time	Event
12:00a	Sneezing produces complex fluid cascade, not a simple spray Here’s some incentive to cover your mouth the next time you sneeze: New high-speed videos captured by MIT researchers show that as a person sneezes, they launch a sheet of fluid that balloons, then breaks apart in long filaments that destabilize, and finally disperses as a spray of droplets, similar to paint that is flung through the air. Using two high-speed cameras, the researchers recorded more than 100 sneezes from healthy human subjects and captured the fraction of a second during which fluid is expelled from the mouth and flung through the air. Almost every sneeze produced the same paint-like pattern of fluid fragmentation, with slight variations: The more elastic the fluid, or saliva, the longer the fluid traveled before breaking into droplets. This complex pattern of fluid breakup runs counter to what most people expect, which is that a sneeze produces a simple and uniform spray of droplets. “It’s important to understand how the process of fluid breakup, or fluid fragmentation, happens,” says Lydia Bourouiba, the Esther and Harold E. Edgerton Assistant Professor and head of the Fluid Dynamics of Disease Transmission Laboratory at MIT. “What is the physics of the breakup telling us in terms of droplet size distribution, and the resulting prediction of the downstream range of contamination?” Bourouiba says understanding how sneezing disperses droplets can help researchers map the spread of infections through the environment, as well as identify individuals who may be “super spreaders.” “This line of work is opening the way for us to gain insights into the variability between human subjects, and to determine to what extent the breakup process of mucosalivary fluid gives us information on the inner physiology of the host,” Bourouiba says. Bourouiba and her colleagues, including Barry Scharfman, a former MIT graduate student; Alexandra Techet, associate professor of mechanical engineering; and John Bush, professor of mathematics, have published their findings in the journal Experimental Fluids. Bursting the bubble The current work builds off research Bourouiba and Bush reported in 2014, in which they showed that coughs and sneezes produce clouds of gas that carry infectious droplets up to 200 times farther than they would have traveled if they were simply disconnected drops. This time around, Bourouiba focused the high-speed imaging on the distribution of droplets produced from sneezing — a more violent expulsion, compared with coughs. For their experiments, the researchers positioned each of three human subjects against a black backdrop and other settings, and set up two high-speed monochrome cameras, focused just in front of a subject’s mouth. To induce sneezing, they “tickled” the subjects’ noses and then recorded as much of the sneeze event as they could — a short window of under 200 milliseconds. After analyzing more than 100 sneezes, the researchers identified a common pattern: Immediately after exiting the mouth, the exhaled fluid can form a wide sheet that balloons with the simultaneous expelling of air. As it travels through the air, the balloon bursts into thin filaments that eventually separate into individual droplets of various sizes that ultimately fall to the ground or remain suspended in the turbulent cloud. The team also observed an interesting variation. For subjects with more elastic saliva, the expelled fluid tended to stay in filament form longer, forming beads along the filaments that eventually slid off as droplets. “What we saw was surprising in many ways,” Bourouiba says. “We expected to see droplets coming out fully formed from the respiratory tract. It turns out that’s not the case at all. And this gives us a good baseline to expand our mechanistic understanding of violent expirations.” Fluid data Bourouiba is currently setting up a new lab space at MIT specifically designed to accommodate parallel experiments to understand various modes of disease transmission. This space will also include a smaller, climate-controlled chamber in which she will be able to visualize sneezes, coughs, and other modes of disease transmission, in collaboration with medical partners. “One of the important goals I have for the lab is to tackle cold and influenza,” Bourouiba says. “Sometimes the symptoms are difficult to distinguish. In the coming year, at different cold and influenza seasons, we will be recruiting human subjects whom we can work with to see them in infection and in health.” Bourouiba will be calling for volunteers to the new lab in the near future.   She says that ultimately, hard data on droplet distributions will help better predict and prevent a disease’s spread. “The way transmission routes are being quantified even today still rely on the traditional way that has prevailed for hundreds of years, which is talking to people to survey who they talked to, where did they go, et cetera,” Bourouiba says. “There are clear limits to the accuracy of the data acquired via this process, and we are trying to have more precise measures of contamination and ranges to root disease control and prevention strategies in the physical sciences.” This research was supported, in part, by the National Science Foundation and the Reed and Edgerton funds at MIT. (Comment on this)
11:00a	Car talk Discussions of self-driving vehicles are often accompanied by highly confident predictions: Visions of the future include whole networks of automated cars seamlessly zipping around metropolitan areas, safely and efficiently, with every person inside them a passive, hands-off passenger. On Tuesday at MIT, the U.S. government’s chief auto safety official offered a more restrained view, suggesting that technology could provide important new safeguards for cars, while observing that it is too soon to say precisely what form vehicular automation will eventually take. “Right now, we really don’t know what the future is,” said Mark Rosekind, administrator of the National Highway Traffic Safety Administration (NHTSA), during a public forum at the Institute. “There’s this image we’ll be taking naps and doing crossword puzzles” while in cars, Rosekind noted, adding that the more immediate question is what it would take to make such a scenario possible. “Can we get there?” he asked.  In his remarks, Rosekind expressed enthusiasm for the possibility of automation-based safety improvements and said that NHTSA is trying to expedite the process through which more testing of automation takes place. The agency aims to complete within six months a policy document through which it can give guidance to automakers and technology companies, and outline a path forward for more experimentation on roads. “I think we need a huge amount of data,” he said. The government’s principal goal while examining all of this, Rosekind emphasized, is safety. “It’s all about the human,” Rosekind said. “The human has to be front and center.” Two views of automation The forum, “The Present and Future of Automated Driving: Technology, Policy, and the Human Factor,” drew an audience of over 250 people to MIT’s Kresge Auditorium. The event was hosted by the MIT AgeLab. Rosekind participated in a conversation with Bryan Reimer, a research scientist at the MIT AgeLab and associate director of the New England University Transportation Center, of which MIT is a part. In his remarks, Rosekind highlighted the large number of auto fatalities in the U.S: There were 32,675 such deaths in 2014. That is actually down substantially — about 20 percent — over the last decade. And yet, Rosekind said, preliminary data indicate the figure may jump back up by 9 percent for 2015, perhaps partly because gas prices have been lower and the volume of vehicles on the road may have thus increased. Rosekind noted that safety technologies, especially seatbelts and airbags, have saved large numbers of lives in recent decades, but automation devices held significant promise. “The question is how we start nailing on better and better technologies,” he said. One of the keys to automated safety, he stressed, was connectivity: making sure vehicles are communicating with each other on the road. “Connected vehicles give you further levels of safety that you can’t get with independent autonomous vehicles,” Rosekind said. Such vehicle-to-vehicle communication, he explained, could help reduce accidents at intersections and in all kinds of scenarios where driver vision is normally limited. On the other hand, Rosekind noted, in response to an audience question, the development of communication among all autos on the road would either require massive retrofitting among current autos or take a long time to phase in: “If you had perfect, connected autonomous vehicles on the road tomorrow, it would still take 20 to 30 years to turn over the fleet.” In response to further questions from the audience, Rosekind acknowledged that issues about data privacy and security from hackers were among the hurdles that have to be cleared in order for automation to jump forward. “Humans aren’t going to trust the vehicles unless you address those [issues],” he suggested. And Rosekind took a neutral stance on one of the main issues involving self-driving cars: whether they could be totally autonomous, which is the direction Google has been moving in, or whether more incremental versions of vehicle automation will take hold, which is what some automakers believe. “Folks tend to separate this into two views,” Rosekind agreed, emphasizing again that the degree of automation was still very much to be determined: “I don’t think we know yet.” (Comment on this)
5:00p	President Reif says that in driving social change, “students have become our teachers” Reviving a tradition that was dormant for more than two decades, this year’s 42nd annual Martin Luther King Jr. celebration at MIT began with a silent march by several dozen students, faculty, staff, and administrators solemnly making their way from Lobby 7 to the annual luncheon at Walker Memorial Hall. There, MIT President L. Rafael Reif began his introduction of the speakers by reminding the assembled crowd that here on campus, “this has been quite a year – an extraordinary year. On topics from race, inclusion and social justice, to climate change, this year our students have, in many ways, become our teachers.” Citing one example of such teaching, Reif recalled a meeting with leaders of two associations of black students, who he said “were thoughtful, creative, persistent, specific, collaborative, constructive, and serious. … They set the tone for mutual respect — and they earned tremendous respect in return.” The groups came with a series of very specific recommendations — and then continued by getting deeply involved in the process of figuring out how to implement those recommendations. They will produce a progress report this spring, he said, which will be made public. “I am confident that we are on a path to sustained and meaningful change,” Reif said. “As one of our student leaders put it recently, ‘It is wonderful to see the gears of MIT go to work on a problem,’ and I could not agree more.” Reif said that student leaders “are making a powerful case that a more welcoming, more inclusive MIT would be better for absolutely everyone. They are right! And I look forward to working with them to make this vision real.” Innovative programs Keynote speaker Freeman Hrabowski has for 24 years been president of the University of Maryland at Baltimore County, which was named by U.S. News and World Report as one of the nation’s most innovative universities. His innovations there, Reif said, included a mentorship program for minority scholars which has resulted in an extraordinary success rate in getting students into advanced degree programs in science, math, and technology — so much so that MIT four years ago adopted its own version of the program. Bringing about these kinds of profound institutional changes, Hrabowski said, involves the entire university community looking inward at its basic values and saying “all of us must be involved if we are to pull people in who have not been historically represented. … We must hear their voices, we must think about who we are and who we want to become.” Hrabowski recalled a time when he was 12, sitting in the back of a church, and he heard an inspirational talk from Martin Luther King Jr. himself, which led him to want to take part in demonstrations that he knew might lead to his arrest. His parents, who had urged him to go to the talk, were fearful about the possible consequences of that action, especially spending time in jail at his young age, but they reluctantly allowed him to go. He was indeed arrested and spent five days in jail. “I was absolutely transformed” by King’s words, Hrabowski said, “because his message was this: That the world of tomorrow could be better than the world of today, and that I, a child, could be part of bringing about that transformation. It wasn’t just about what he would do or what my parents would do.” Even after his horrible experience in jail, he said, he came out feeling empowered, knowing that even as a child, his actions could be part of making a real difference. Speaking to the students in the audience, he said “you do have the right and the ability to speak truth to power” — the theme of this year’s MLK lunch. Real change has taken place, he said — the diversity represented there in the room, he said, would have been hard to find in Boston in the 1960s. Voting rights and other important legislation have made a difference, and rates of college graduation for minorities, for example, have increased about tenfold since then. “Every group has gotten better off as a result of that,” he said. Everyone is struggling Quoting the poet Guillaume Apollinaire, Hrabowski said “the joy always comes after the struggle.” Anybody who is trying to achieve anything substantive in the world is struggling, he said. “We have to keep working at it. … Nothing takes the place of hard work and attitude.” “I challenge MIT,” he said: “Be the best, not just for STEM but for humankind. Watch your thoughts, they become your words. Watch your words, they become your actions. Watch your actions, they become your habits. Watch your habits, they become your character. Watch your character, it becomes your destiny. Dream!” Itoro Atakpa, a junior in mechanical engineering, talked about her own experiences as an African-American student at MIT and urged her fellow students to be involved in improving the feeling of inclusiveness for everyone on campus. “We have to be proactive in helping each other to understand. This is the only way to identify and address the resources that are missing here,” she said. Atakpa said that students should spread the message of inclusiveness like a kind of benign contagion. “I challenge you to infect others with your voice,” she said. “The voices in your head don’t have to be a silent and personal affliction; they should be an epidemic on the grounds of our campus. Because you are the revolutionary, you are the difference. And I know from experience that once someone catches wind of your emotion and listens to your thoughts and ideas, the virus of your voice is chronic and incurable.” And graduate student Sergio Hiram Cantu said, “we need to help empower others.” Being accepted to MIT, coming from one of the nation’s poorest cities, “felt like winning the lottery,” he said. And when he arrived here, “to my surprise, MIT felt like a family to me.” But he added that “even though MIT has come a long way, we still have a long way to go” in making everyone feel welcomed, included, and supported. “You have a lot more power than you realize,” he implored. Quoting from Martin Luther King, he said, “if you can’t fly, then run. If you can’t run, then walk. Whatever you do, keep moving forward.” (Comment on this)

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