Boston University Physics News Archive: 2012
Professor Antonio Castro Neto was recently elected as a Fellow of the American Association for the Advancement of Science (AAAS). The organization, which publishes the journal Science, seeks to "advance science, engineering, and innovation throughout the world for the benefit of all people." This year, 701 members were selected as Fellows for their contributions to science and technology.
Professor Bennett Goldberg was given this year’s United Methodist Scholar/Teacher of the Year Award in recognition of his commitment to both teaching and research. The award is given to a member of the Boston University faculty recognized for his or her “dedication and contributions to the learning arts and to the institution”; it was established and endowed by the General Board of Higher Education and Ministry of the United Methodist Church. Read more at the CAS website.
Graduate student Cory Fantasia has been selected as one of the winners of a competition organized by the US LHC Users Organization (USLUO). 15 postdocs and students were selected by the LHC experiments to present plenary talks at the annual USLUO meeting held at Fermilab on Oct 18-20, 2012. These talks were entered into a competition for 6 prizes. Cory Fantasia's talk on "Search for exotic WZ resonances with the CMS detector" won one of these prizes and Cory has been selected to join the USLUO Executive Committee on visits to Washington, DC in Spring 2013, to discuss particle physics with congressional and executive offices. Cory is jointly advised by Profs. Tulika Bose and Kenneth Lane and is currently based at the CMS experiment at CERN.
Boston University physics department alumnus Eli Ben-Naim has been appointed senior editor of Physical Review E. Ben-Naim wrote his 1994 thesis on the topic of Kinetic Properties of Stochastic Processes, supervised by Prof. Sid Redner. Ben-Naim was also a past winner of the department's Goldhaber Prize. Ben-Naim's most recent position is in the Theoretical Division of Los Alamos National Laboratory.
Graduate student Mikkel Herholdt Jensen and collaborators were highlighted in The Journal of Biological Chemistry for their work, “The conformational state of actin filaments regulates branching by Arp2/3 complex”. The article was chosen by the editorial board as the JBC paper of the week for its significance and overall importance.
The work was conducted by Mikkel Herholdt Jensen (Boston University Physics Department; Moore lab) and Eliza J. Morris (Harvard University School of Engineering and Applied Science; Weitz lab), in collaboration with researchers at Boston Biomedical Research Institute and the University of Pennsylvania.
The focus of the research is actin, a cytoskeletal protein which plays a critical role in cell motility. A cell's ability to move is driven by the assembly of monomeric actin into filaments, physically pushing on the cell membrane and forming cell protrusions at the leading edge of the cell. The actin assembly involves actin-binding proteins, such as the actin-related protein 2/3 (Arp2/3) complex, which nucleates actin filaments and forms branched actin filament structures. The Arp2/3 complex specifically targets newly polymerized actin at the leading edge of the cell, but the underlying mechanism for this selectivity is not well understood. This recent work demonstrates that caldesmon, a second actin-binding protein, increases the Arp2/3-mediated branching activity when bound to newly formed actin filaments and maintains the filaments in a state of high Arp2/3 affinity. Upon caldesmon unbinding, however, the actin transitions to a second state with low Arp2/3 complex affinity. This presents a novel regulatory mechanism in which the tuning of the actin filament state by caldesmon regulates actin’s interactions with other binding partners.
The work can be viewed online at http://www.jbc.org/content/287/37/31447.
|Example of fluorescence confocal image of actin polymerizing in the presence of Arp2/3 complex. Actin filaments (green) were first prepolymerized either with (A) or without (B) caldesmon present. After several hours, a second color of fluorescent monomeric actin was added and allowed to polymerize (red). The caldesmon-decorated actin exhibited more Arp2/3-induced actin branches, indicated by white arrows. Scale bar is 5 μm.|
|Close-up fluorescence confocal image of two actin branches exhibiting the ~70° angle characteristic of Arp2/3-induced actin branches.|
On July 23rd and 24th, 24 participants in the Artemis program visited the Boston University Physics Department Electronics Design Facility. Artemis is a five-week summer program directed by undergraduate women at Boston University which introduces rising 9th grade girls to computer science. As part of their activities in the program, they spent two days assembling and testing a programmable music synthesizer. The design was made by B.U. undergraduate ECE student Chris Woodall. They learned some basic electronics, soldering skills and a little music theory. Pictured here is EDF director Eric Hazen helping install batteries in one of the finished synthesizers. Also helping with instruction were BU physics graduates Chelsea Bartram, Dan Gastler and Charlie Hill, and BU engineering students Sam Damask and Chris Woodall. Thanks also to Artemis advisor Cynthia Brossman.
On August 4 & 5, 2012 the Physics Department and the Center for Neuroscience hosted Sabermetrics, Scouting and the Science of Baseball, an annual seminar to benefit the Jimmy Fund. Registrants got up close with some of baseball’s top coaches, statisticians, scouts, doctors, and scientists to learn how science, advanced baseball statistics, and traditional scouting assessments come together to drive America's favorite pastime. BU Physics Professor Sid Redner and PhD alum Alex Peterson were speakers at the event, which raised over $16,000 and was covered by the Boston Herald and MLB.com.
Congratulations to graduate student Jessica Morrison and husband, Paul on the arrival of their son, Ryan Michael Morrison. Ryan made his appearance earlier than expected on August 1 at 7:49 AM. He weighed in at 4 lbs 6 oz and 16 inches long. He is holding his temperature and eating really well while in the Neonatal ICU in Salem.
Richard Averitt and colleagues have published a letter in Nature entitled “Terahertz-field-induced insulator-to-metal transition in vanadium dioxide metamaterial”. This work is a collaboration with Prof. Keith Nelson’s group at M.I.T., Prof. Stuart Wolf’s group at the University of Virginia, Prof. Xin Zhang at B.U., and Prof. Fiorenzo Omenetto at Tufts. The lead authors are Boston University graduate student Mengkun Liu (now a postdoc at UCSD) and M.I.T. graduate student Harold Hwang.
This work demonstrates that it is possible to drive the insulator-to-metal transition in vanadium dioxide (VO2) – a canonical correlated electron material – on a picosecond timescale using high-field terahertz pulses. To achieve the required fields, metamaterial field enhancement was achieved by directly depositing split ring resonators on the VO2. At the highest fields of approximately 4 MV/cm, irreversible damage occurs as shown in the figure. This novel approach provides a powerful platform to investigate low-energy dynamics in condensed matter and demonstrates that integration of metamaterials with complex matter is a viable pathway to realize functional nonlinear electromagnetic composites.
Image of a metamaterial split ring resonator that is 75 um X 75 um with 1.5 um gaps. Within the gaps strong field enhancement of incident terahertz radiation leads to a rapid increase in the energy density inducing a field-driven insulator-to-metal transition. The field enhancement and resultant phase transition occur on an extreme subwavelength scale. The white regions are damage that occur at the highest incident field.
Claudio Castelnovo (Ph.D. 2006) has been awarded the 2012 EPS Condensed Matter Division Europhysics Prize for the prediction of magnetic monopoles in spin ice. The prize was shared with experimentalists who observed the effect via neutron scattering measurements on dysprosium titanate.
The effect is an example of fractionalization phenomena, whereby the elementary excitations of the system have charges that are only a fraction of the fundamental constituents. The notion of fractionalization first appeared in physics through the work of Roman Jackiw and Claudio Rebbi, who showed that excitations with half the charge of the electron appear around certain topological defects. In the case of spin ice the fundamental constituents are magnetic dipoles, but the magnetic monopoles predicted by Claudio Castelnovo emerge as the deconfined elementary excitations of the effective gauge theory describing spin ice.
The ATLAS and CMS experiments announced at a seminar at CERN on July 4th, 2012 the observation of a new particle in the search for the elusive Higgs Boson. This search for this new particle took form almost 40 years ago, when physicists assembled what is now known as the Standard Model. The model organizes the fundamental constituents of matter and the forces that determine how they interact. The role of the Higgs particle is to confer mass to the elementary particles and is a crucial piece of the Standard Model.
While presenting strong evidence for the existence of a new particle, the LHC experiments need more data to confirm whether the new particle has properties consistent with the Standard Model Higgs Boson or how well its properties match the Standard Model predictions. In any case this is one of the most significant breakthroughs in physics in decades.
The Boston University Physics Department has faculty members working on both ATLAS (Ahlen, Black, Butler, Shank) and CMS (Bose, Heister, Rohlf, Sulak) in addition to a number of post-doctoral research associates and graduate students on each experiment. The connections with Boston University particle physicists as well as undergraduate students in the University of Geneva exchange program was highlighted in BU Today.
|An event display from the CMS detector visualizing one of the collisions that has produced what may be a Higgs particle.|
|An event display from the Atlas detector visualizing one of the collisions that has produced what may be a Higgs particle.|
Prof. Antonio Castro-Neto from our Department and recent Nobel Laureate Andre Geim have a special "Instant Expert" article on graphene in the May 5 issue of New Scientist. The lavishly illustrated article provides an excellent overview of the properties and possible technological uses of this unique material for non-specialists. The online articles require a subscription to New Scientist, but a copy is kept for review at the front office entrance.
It is with great sadness that we report that Bob Kingsland passed away on June 22. Bob was a world-class welder who made very complicated vacuum chambers for several of our faculty. Bob also did sophisticated aluminum welding for the muon g-2 experiment. Bob was central to the development of the Student Training Facility in the SIF, where he was beloved by generations of his students. Bob's celebration of life will be on Wednesday, July 11th, at 3 PM at the First Parish Unitarian Universalist church in Scituate (330 First Parish Road, Scituate, MA 02066). A reception at the Lighthouse Keeper's in Cohasset (15 Lighthouse Lane, Cohasset, MA 02025) will follow. Carpooling is recommended. Visit the Richardson-Gaffey website to read about Bob's remarkable life, leave a message, and for further memorial service details.
Andrew Duffy was named as the 2012 winner of the Metcalf Cup and Prize, the most prestigious teaching award of Boston University. It recognizes Andrew's accomplishments in teaching, pedagogical developments, and his positive influence on a large cadre of students. This award will be officially bestowed at the BU Commencement ceremonies on Sunday May 20.
Boston University graduate student David Sperka won one of the ten graduate student awards recently announced by the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC). This is a rare achievement for a third year graduate student in a 4000 member collaboration with over a thousand students. David was nominated for his “outstanding High Level Trigger work on CPU performance, muon triggers and on-call support”. David is currently based at the LHC@CERN, serves as a 24/7 on-call expert for the CMS Trigger, and is working on searches for new heavy gauge bosons at the LHC. David works with Assistant Prof. Tulika Bose.
Pankaj Mehta and co-author David Schwab's axiv paper "The Energetic Costs of Cellular Computation" has been highlighted by the MIT Technology Review Physics Arxiv Blog. The paper explores "what restrictions the theoretical limits of computation place on the way living things operate." For more, see the original paper or the synopsis from Technology Review.
Professor Anatoli Polkovnikov received a prestigious Simons Fellowship in Theoretical Physics, together with 27 other distinguished physicists from USA and Canada for the 2012-2013 academic year. The purpose of the fellowship is to allow grantees to extend their sabbatical leaves to last for a full academic year. The Simons Fellows Programs in Mathematics and Theoretical Physics was created to provide funds to faculty for up to a semester-long research leave from classroom teaching and administrative obligations. Information about the Simons Fellowship program can be found at https://simonsfoundation.org/mps-funded-programs-simons-fellows-program.
The findings of Boston University physics department alumnus Alexander Petersen and graduate student Joel Tenenbaum have been featured in Science News, MSNBC, the Wall Street Journal, and other news outlets. Their work draws statistical connections between business firms competing for market share and words “competing” for usage by speakers across three languages. They quantify the “tipping point”, at which an emerging word will go mainstream and show that significant historical events, such World War II and the founding of Israel, affect the way words “compete” with each other. The work is published in Scientific Reports at nature.com:
Congratulations to Martin Schmaltz, promoted to full professor. The full professor promotions were reported in BU Today. Quoting from the Dean's announcement:
Martin Schmaltz, CAS, Physics, specializes in theoretical particle physics, with a focus on extracting the fundamental physics underlying the results from the Large Hadron Collider (LHC) at CERN in Switzerland. A widely respected author of dozens of papers and journal articles, he has emerged as one of the nation’s top experts in creating new hypotheses to extend the Standard Model of Particle Physics, hopefully to be tested by the LHC experiments.
The Alfred P. Sloan Foundation announced today the selection of 116 outstanding early career scientists, mathematicians, and economists as Alfred P. Sloan Research Fellows. Assistant Professor Tulika Bose was one of the recipients of the prestigious fellowship. Prof. Bose is presently stationed at CERN working on the CMS experiment at the Large Hadron Collider.
UPDATE: BU Today has posted an article congratulating Bose and two other BU Sloan Fellowship recipients.
Tulika Bose with students Cory Fantasia, David Sperka, and postdoc Aram Avetisyan
Profs. Ophelia Tsui and Andy Cohen become mother and father on January 14, 2012. They welcomed into the world their new son Kirin Lawrence Cohen with a mass of 2.95 kilograms. Everyone is doing well. Congratulations and best wishes!
Charles Hill and Sylvia Lewin, graduating seniors in the Physics Department, have been elected to membership in Phi Beta Kappa by the Epsilon of Massachusetts Chapter at Boston University. They join Lina Necib as electees to this meritorious organization. Congratulations to all three students!
Boston University Physics graduate student Gustavo Marques Tavares won one of four fellowships awarded nation-wide by the NSF funded Large Hadron Collider Theory Initiative. The fellowship provides salary, tuition, travel to conferences and research support. Gustavo is a second year student in the Ph.D. program at BU and is working with the Theoretical Particle Physics group. The fellowship will support his research to explain the top quark asymmetry at the Tevatron. Gustavo co-authored two publications in which he proposed new models for the top quark asymmetry. He is currently working on predictions for the LHC experiments.
Aside from his Physics research Gustavo enjoys snowboarding, soccer, spending time with friends, and exploring Boston.