SPS Zone Meeting at GW a great success

On April 17 and 18, the GW Society of Physics Students (SPS) hosted the SPS Zone meeting, where students from all over the District of Columbia, Maryland, and Virginia came together for a true physics celebration. Almost thirty students from eleven different campuses gathered to learn about various aspects of physics, prepare for life after undergraduate studies, and to present themselves, their research, and some very exciting physics demonstrations, to other students and faculty.

The kick-off was on Friday evening with a lecture by Daniel Golombek, currently the Manager for Membership & Leadership at the SPS National Office, but for a large part of his career involved in the Hubble Space Telescope mission at the Space Telescope & Science Institute. He captivated the audience with some of the most beautiful astrophysical pictures ever made, showcasing many great results from Hubbles’s 25 years in space. On Saturday morning, the astrophysics theme was continued in an inspiring lecture by Chryssa Kouveliotou, former Senior Scientist at NASA’s Marshall Space Flight Center, and now the newest professor in the GW Physics Department. She discussed what it takes to be an astrophysicist, what the rewards and challenges are, and presented a long-term vision for the future of astrophysics. She also showed how theoretical computations, simulations, and observations across the electromagnetic spectrum need to come together to understand some of the most enigmatic phenomena in the Universe: Gamma-Ray Bursts.

After enjoying the talks, it was time for the students to present their research in the poster session. The topics covered in the posters varied across almost all physics disciplines, so both students and faculty present had an opportunity to learn a lot about research outside of their own fields: electromagnetic levitation; research that might lead to skin patches to monitor health; even an explanation as to how geckos scale walls! At the poster prize ceremony in the evening, the jury, consisting of faculty members from different universities, remarked that the overall level of the posters was very high, but that they were even more impressed by the standard of the presetations made by the students, the depth of their knowledge. and how well they explained their research.

Saturday afternoon began with a graduate student panel, in which the SPS students could ask graduate students in different physics fields about their experiences of applying for graduate school, taking graduate level classes, and doing research, which led to vivid discussions. This was followed by a physics-related treasure hunt on the GW campus, and several demonstrations of fun physics experiments by many of the students. The outreach demonstrations included a vacuum gun with ping pong balls, which crushed soda cans to dramatic effect; simulating supernova explosions with bouncing disks; predicting the rolling speed of differently shaped objects; playing with non-Newtonian fluids, leaving some of the faculty covered in cornstarch; and making and eating liquid nitrogen ice cream.

The final event of the day was a workshop by Sean Bentley, the Director of the SPS National Office. He presented the American Institute of Physics Career Toolbox, discussed the various options there are after finishing undergraduate studies in physics, and engaged the students in some exercises to demonstrate how to build their resume and prepare for job interviews.

The SPS Zone Meeting at GW was a great success! The hard work of the GW students in the preparations and throughout the meeting under the invaluable guidance of Professor Gary White, and the enthusiasm of all the students present at the meeting led to a very successful meeting which helped prepare the next generation of physicists and was thoroughly enjoyed by all! 

(Pictures courtesy of the NOVA Community College SPS group)

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Colloquium: May the force be with the Ring, or not–bacterial cytokinesis in super resolution

Colloquium on Thursday, 9 April, at 15:45 in the Lehman Hall of the SEH by

Jie Xiao

Johns Hopkins School of Medicine

During cytokinesis, a mechanical force constricts the cell envelope against an internal turgor pressure. In bacteria, this force is attributed to the essential ‘divisome’ machinery. The most conserved divisome component is the FtsZ ring, or Z-ring, which comprises protofilaments of the bacterial tubulin homolog and GTPase, FtsZ. Although the Z-ring has been a prevailing candidate for constrictive force generation, proposed force generation mechanisms have been difficult to test in vivo due to the essentiality of FtsZ, the limited ability to spatially resolve the Z-ring structure in small bacterial cells, and the lack of sensitive methods to monitor Z-ring contraction and the rate of septum closure during cytokinesis.

We applied quantitative single-molecule based superresolution imaging with other biophysical techniques and genetic manipulations to examine the structure of the Z-ring and possible force generation mechanism during cytokinesis. We found that the Z-ring is composed of discontinuous and heterogeneous FtsZ clusters, and that this disordered organization is stabilized by a multi-layered protein network in the cytoplasm anchoring the Z-ring to the chromosome. Most Surprisingly, we found that the rate of septum closure is robust to substantial changes in many Z-ring properties during cytokinesis: the GTPase activity of FtsZ, molecular density of the Z-ring, and the timing of Z-ring assembly and disassembly. Instead we show that septum closure is highly coupled to the rate of cell wall growth, and can be modulated by coordination with chromosome segregation. Taken together, our findings support a model in which the roles of cell wall growth and chromosome segregation dominate that of the Z-ring in defining the rate of septum closure during constriction in E. coli. These results challenge the FtsZ-centric view of constrictive force generation in bacteria, and suggest that FtsZ should be viewed as a key structural scaffold, regulator, or mediator rather than as a major force generator.


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Colloquium: Exploring the Violent Universe: A Data-Driven Approach to X-ray Astronomy

Colloquium on Thursday, 2 April, at 15:45 in the Lehman Hall of the SEH by

Daniela Huppenkothen

New York University

Despite its static appearance to our eyes, the night sky is incredibly dynamic. This is true especially at short wavelengths—in X-rays and Gamma-rays—where we see some of the universe’s most extreme phenomena: accreting black holes, ultra-dense neutron stars and stellar explosions. Many of these phenomena vary on time scales of  milliseconds to years, allowing us to probe physical processes by studying how these sources change with time. By its very nature, research in this field is observationally driven, since it is often the unexpected, serendipitous observations that allow advances in our understanding of the underpinning source physics. At the same time, we have built up vast data archives with past and current telescopes that allow for large-scale sample studies and have developed new approaches to large data sets that help us deepen our understanding, if we can mine these archives efficiently.
In this talk, I will introduce Data Science as an emerging field, and use examples from X-ray astronomy to show how a data driven approach to astrophysical research questions can enhance our understanding and guide theoretical developments.


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2015 Berman Memorial Lecture: Prof. Otto Zhou

The Department of Physics is pleased to announce the

2015 Barry Berman Memorial Lecture

Thursday, March 19th, 2015 3:45 pm in the Lehman Auditorium of the Science and Engineering Hall

Otto Zhou, Ph. D, University of North Carolina at Chapel Hill

The Story of Carbon Nanotube X-Ray

From Scientific Curiosity to Patient Imaging

X-ray radiation is widely used in many aspects of our lives, including medicine, security, and industrial inspection. The way x-ray is generated, however, has not changed significantly since it was discovered over one hundred years ago. Utilizing the unique properties of the carbon nanotubes, we developed a novel spatially- distributed field emission x-ray source array technology. After 10 years of intensive R&D efforts, the technology has been successfully translated from a scientific curiosity to commercial production. Its applications in medical imaging, radiation therapy, and homeland security are being actively investigated, including 3D imaging systems for early detection of breast cancer and lung cancer. Some say technologies are even being evaluated in patient trials. In his talk, Dr. Zhou will describe the working mechanism and properties of the carbon nanotube x-ray source technology and introduce some of its applications in imagining and therapy.

About the Speaker:

Otto Zhou is the David Godschalk Distinguished Professor of Physics and the Lineberger Comprehensive Cancer Center at the University of North Carolina at Chapel Hill. His translational research laboratory develops and clinically validates systems for medical imaging and radiotherapy utilizing the carbon nanotube field emission x-ray array technology pioneered by his team. His current research focuses on digital tomosynthesis for early detection of breast cancer and lung cancer, microbeam radiation therapy for treatment of brain tumor. He has published about 200 technical papers and holds around 50 issued/pending U.S. patents, and is a co-founder of Xintek and XinRay Systems. He received his PhD degree in Materials Sciences from the University of Pennsylvania, trained at the Bell Laboratories and worked at NEC before joining UNC. He is an elected fellow of the American Institute of Medical and Biological Engineering.

About the Lecture Series:

In 2011, The Barry Berman Memorial Lecture Series was created through a generous gift by one of his close collaborators and colleagues, Professor Cedric Yu, a faculty member at the University of Maryland School of Medicine, Department of Radiation Oncology. Professors Berman and Yu formally worked together under a NIH-funded project on radiation cancer therapy. The goal of the lecture series is to inspire young people to study medical physics, by inviting nationally and internationally prominent scientists to speak on the application of physics principles to medicine.

Each gift, no matter how large or small, makes a positive impact on our educational mission and furthers our standing as a dynamic and growing physics department in one of the world’s outstanding universities.  If you would like to contribute to this fund or another department initiative, you may make a gift to the Department securely online at https://my.gwu.edu/mod/onlinegiving/, specifying “Department of Physics” under “Others” or in the “Comments/Instructions” section.

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π-Day of the Century: 3.141592653… = 3/14/15 9:26:53

This is a Public Service Announcement: Have Some Pi!

Your choice if you celebrate pm or am.

Of course, it only works when you write dates the American way, not like the Rest of the World.

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