Boston University Physics News

Teacher in Residence Mark Greenman has been honored with the 2012 Paul W. Zitzewitz Award for Excellence in Pre-College Physics Teaching by the American Association of Physics Teachers (AAPT). In addition to his 30 year career as a science educator at Marblehead High School in Massachusetts, Greenman has received many awards and honors, including the Presidential Award for Excellence in Mathematics and Science Teaching for Massachusetts and an Albert Einstein Distinguished Educator Fellowship from the National Science Foundation. More information is available on the AAPT website.

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.

http://publish.aps.org/edannounce/ben-naim-pre-2012

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.

Click here for more about the music synthesizer.

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.

CAS News article: http://www.bu.edu/cas/2012/07/26/researchers-at-bu-mit-make-breakthrough-in-study-of-terahertz-radiation/

Nature: http://www.nature.com/nature/journal/vaop/ncurrent/full/nature11231.html

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.