Friday, March 21st, 2014

Time	Event
4:00a	3 Questions: John Tirman on the warming U.S.-Iran relationship The U.S. and Iran have had a largely antagonistic relationship since the Iranian Revolution of 1979. Could that be changing? In January, Iran and a U.S.-led group of six global powers agreed to an interim six-month deal that freezes Iran’s nuclear weapons program, in exchange for the lifting of some economic sanctions. The progress on the issue indicates that U.S.-Iran difficulties are not wholly intractable, suggests John Tirman, a principal research scientist and executive director of MIT’s Center for International Studies. Tirman is the co-editor of a new book on the subject, “U.S.-Iran Misperceptions: A Dialogue,” just published by Bloomsbury Press, which features essays by scholars and policymakers from both countries. Tirman recently talked with MIT News about the topic. Q. What are the main misperceptions on both sides of the U.S.-Iran relationship? A. Well, there are so many. On the Iranian side, it’s their belief that the U.S. has been out to get them for 60 years. It’s not without some foundation, but it’s exaggerated. One of the things that I think is important to understand about the U.S.-Iran relationship is that for Iran, the U.S. really is the dominant nation in their foreign policy. This Iranian sense of foreigners meddling to harm the nation is extremely strong. That’s the strongest misperception on the part of Iran. On the United States side … I think the perception of Iran — and we looked very closely at polling in the United States over a period of time from the beginning of the 1980s — has been pretty consistent. The American public views Iran as unreliable, irrational, out to cause trouble, wanting a nuclear weapon, and being hostile to Israel. Some of those things are true. And those two sets of perceptions are very much alive today. Q. If there are so many misunderstandings between these two nations, then what are some of the potential substantive areas of agreement that may be undervalued right now? A. It’s been said by many people, not just me, that the United States and Iran have many overlapping interests on which they could find agreement. Part of it is just an interest in bringing stability to the region. It’s the Arab states and Afghanistan and Turkey that are really in flux. The interesting thing about Iran during the period of the Islamic Republic is that is has generally not been expansionist … it has an interest in asserting its regional power, but it has for the most part shown an interest in stability. And we should encourage that. One way to encourage that is to come with some sort of agreement on diplomatic relations, and then to get the nuclear deal done, which I think is quite feasible. And of course to lower the rhetoric about Israel, which I think they’ve been doing. All these things are important to the U.S. Q. The U.S. and other countries want to inhibit Iran’s capacity to produce nuclear weapons; in return, they might lift economic sanctions. We’ve just had an interim deal on this. What needs to happen for a permanent agreement to be reached? A. First of all, where we are today compared to a year ago is like night and day. It’s easy for people to forget that the change has been remarkable. You can see the change in just the simple fact that the U.S. and Iran can talk any day, and do often, and we have the interim agreement. The talks are constructive; they’re not just hurling insults at each other, for the first time in 35 years. That’s the result of the Iranian election, but it’s also the result of the choices [Iranian President Hassan] Rouhani has made. He’s very knowledgeable about international affairs, was a nuclear negotiator, and chose, in my opinion, the best possible person to be foreign minister, Mohammad Javad Zarif, who was educated in the U.S. He knows America, and one of the things that’s really different is not just ideology, it’s familiarity. Zarif understands the American political system, and previous Iranian leaders didn’t have that feel. When [members of Congress] blast away at Iran, Zarif, I assume, understands when that’s old-fashioned pandering to a domestic constituency. [Iranian politicians] do the same thing; we just don’t read about it that much. But that kind of thing used to be misinterpreted. So that’s a huge change. The agreement itself, and the apparent sincerity and determination of the Iranians to make it work, are good signs. And I give [John] Kerry a lot of credit; he’s been indefatigable as secretary of state. He’s lucky he got Zarif as his counterpart, but luck has to be converted into something — and he has done that. One of the things Kerry and [President Barack Obama] have done well is to address some of the difficult areas on enrichment. They did that in the interim agreement, and they’re going to have to do it again and sell it to Congress. The outlines of the deal have always been apparent. The U.S. wants to stop [Iran] from enriching uranium to 20 percent, because that’s the launching pad, so to speak, to get to breakout capability [to produce weapons] — and to get Iran to walk back a couple of other pathways to weaponization, and be very transparent about it. So it’s a matter of making that more permanent in the comprehensive agreement and working out areas that have been left hazy. The hard part is going to be getting Congress to lift the economic sanctions. There are some, apparently, [that Obama] can suspend, but there are some that Congress has got to change, and that’s going to be very hard. A comprehensive agreement has to be written with stages in mind: Iran does X, we verify, until confidence is built and a case can be made to lift the sanctions. Whether Iran can swallow that timeframe is one of the big questions. But we’re moving in the right direction. (Comment on this)
4:00a	Cells get ready for their close-up In 2007, MIT scientists developed a type of microscopy that allowed them to detail the interior of a living cell in three dimensions, without adding any fluorescent markers or other labels. This technique also revealed key properties, such as the cells’ density. Now the researchers have adapted that method so they can image cells as they flow through a tiny microfluidic channel — an important step toward cell-sorting systems that could help scientists separate stem cells at varying stages of development, or to distinguish healthy cells from cancerous cells. Other sorting methods require scientists to add a fluorescent molecule that highlights the cells of interest, but those tags can damage the cells and make them unsuitable for therapeutic uses.  “Many stem cell applications require sorting of cells at different stages of differentiation. This can be done with fluorescent staining, but once you stain the cells they cannot be used. With our approach, you can utilize a vast amount of information about the 3-D distribution of the cells’ mass to sort them,” says Yongjin Sung, a former postdoc in MIT’s Laser Biomedical Research Center and lead author of a paper describing the technique in the inaugural issue of the journal PRApplied. Instead of using fluorescent tags, the MIT method analyzes the cells’ index of refraction — a measurement of how much the speed of light is reduced as it passes through a material. Every material has a distinctive index of refraction, and this property can be used, along with cells’ volume, to calculate their mass and density. Different parts of a cell, including individual organelles, have different indices of refraction, so the information generated by this approach can also be used to identify some of these internal cell structures, such as the nucleus and nucleolus, a structure located within the nucleus. In the original 2007 version of this technology, known as tomographic phase microscopy, researchers led by the late MIT professor Michael Feld created 3-D images by combining a series of 2-D images taken as laser beams passed through cells from hundreds of different angles. This is the same concept behind CT scanning, which combines X-ray images taken from many different angles to create a 3-D rendering. For the past few years, Sung and others in the Laser Biomedical Research Center have continued developing the tomographic phase microscopy system. In a paper published in 2012, the MIT team used the technique to measure the mass of chromosomes in living cells; last year, working with Marc Kirschner of Harvard Medical School, the researchers studied volume and density changes in cartilage cells as they differentiated into their final form. For the new PRApplied study, the MIT researchers collaborated with Daniel Irimia’s lab at Harvard Medical School to adapt the system to image cells as they flow continuously through a microfluidic channel. Other researchers have tried to do this, but their systems required that the cells be halted at a certain point in the channel to complete the imaging. “The only moving part in our system is the sample, which will afford great flexibility in miniaturizing the system,” says Sung, who is now an instructor in radiology at Massachusetts General Hospital. A key feature of the new MIT system is the use of a focused laser beam that can illuminate cells from many different angles, allowing the researchers to analyze the scattered light from the cells as they flow across the beam. Using a technique known as off-axis digital holography, the researchers can instantaneously record both the amplitude and phase of scattered light at each location of the cells. “As the cell flows across, we can effectively illuminate the entire sample from all angles without having to rotate a light source or the cell,” says former MIT graduate student Niyom Lue, a coauthor of the new paper. Changhuei Yang, a professor of electrical engineering and bioengineering at the California Institute of Technology, says the new system is “a very interesting development in the research area of efficient microscopy imaging.” “The research group very nicely demonstrates that the combination of cell flow as a scanning strategy with line illumination can provide high-quality holographic data for rendering 3-D images of the target cells. As a method, I think this approach has a lot of promise in cytometry type applications,” says Yang, who was not involved in the research. The current system can image about 10 cells per second, but the researchers hope to speed it up to thousands of cells per second, which would make it useful for applications such as sorting stem cells. The researchers also hope to use the system to learn more about how cancer cells grow and respond to different drug treatments. “This label-free method can look at different states of the cell, whether they are healthy or whether they maybe have cancer or viral or bacterial infections,” says Peter So, an MIT professor of mechanical engineering and biological engineering who is senior author of the new paper. “We can use this technique to look at the pathological state of the cell, or cells under treatment of some drug, and follow the population over a period of time.” The research was funded by the National Institutes of Health and Hamamatsu Photonics. Other authors of the paper are MIT principal research scientist Ramachandra Dasari; former MIT postdoc Wonshik Choi; MIT research scientist Zahid Yaqoob; and Bashar Hamza and Joseph Martel of Harvard Medical School. (Comment on this)

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