Department Colloquia

Fall 2023

October 30, 2023

Visit event details.

Spring 2023

Tuesday, January 31, 12:30 p.m.

• Title: Bio-Inspired Design of Self-Assembling Synthetic Collagen Fibers
• Speaker: Vikas Nanda (Rutgers University)
• Venue: Zoom
• Abstract: Collagens are the most abundant proteins of the extracellular matrix, and the hierarchical folding and supramolecular assembly of collagens into banded fibers is essential for mediating cell-matrix interactions and tissue mechanics. Collagen extracted from animal tissues is a valuable commodity, but suffers from safety and purity issues, limiting its biomaterials applications. Synthetic collagen biomaterials could address these issues, but their construction requires molecular-level control of folding and supramolecular assembly into ordered banded fibers, comparable to those of natural collagens. I will discuss the design and characterization of a class of banded fiber-forming synthetic collagens that recapitulate the morphology and some biological properties of natural collagens.

Thursday, March 2, 12:30 p.m.

• Title: Binding Free Energy of Different Variants of SARS-CoV(-2) Virus with hACE2 Receptor Protein
• Speaker: Narayan Adhikari (Tribhuvan University, Nepal)
• Venue: Zoom
• Abstract: Some of the variants of SARS-Cov(-2) virus are more severe than others. We performed classical molecular dynamics simulation of different variants of SARS-CoV(-2) virus and human receptor (hACE2) protein to get more insight in this severity of the virus. The binding free energy of SARS-CoV(- 2) variants like delta, beta, mu, omicron and wild type with hACE2 have been estimated using Umbrella Sampling. Our investigation shows that delta variants has highest binding free energy than others. To understand this binding free energy we have also studied hydrogen bonding, salt bridges, electrostatics and van der Waals interactions of these variants with human receptor. The average number of hydrogen bonds in wild type, delta, mu and omicron variants have been calculated to be 7, 7, 5 and 5 respectively. Moreover binding free energy for wild type, delta, mu and omicron variants with hACE2 by MM/GBSA method have been estimated to be -44.15 ± 8.07 kcal/mol, -44.93 ± 7.69 kcal/mol, – 37.31 ± 7.98 kcal/mol and -36.20 ± 7.61 kcal/mol respectively.

Thursday, March 9, 12:30 p.m.

• Title: An Astronomical Simulation Device From Ancient Greece: the Antikythera Mechanism
• Speaker: Alexander Jones (New York University)
• Venue: Zoom only (link TBC)
• Abstract: In 1901, fragments of a complex gearwork mechanism were recovered from the site of a shipwreck that took place around 60 BCE off the small Greek island of Antikythera. Thanks to more than a half-century of intensive study, most recently with the assistance of X-ray Computed Tomography and Reflectance Transformation Imaging, we now have detailed, if not quite complete, knowledge of its appearance, functions, and workings as a device for simulating the apparent motions of the Sun, Moon, and planets as seen from the Earth along with chronological cycles pertaining to calendars and eclipses. In this talk I will show how the Antikythera Mechanism fits with and augments our understanding of ancient Greek astronomy and the engagement of ancient astronomers with a broader public.

Thursday, March 23, 12:30 p.m.

• Title: Conformal Invariance of Lattice Models from Statistical Mechanics
• Speaker: Christian Beneš (Mathematics Department, Brooklyn College)
• Venue: Hybrid (venue and matching Zoom link TBC)
• Abstract: Many physical phenomena can be described by discrete random processes or discrete random configurations: Random walks describe molecular movement; the self-avoiding walk was introduced to describe the behavior of polymers; the Ising model is a model for ferromagnetism; percolation models transport in porous media. Rather surprisingly, the last three of these models have scaling limits (obtained by letting the lattice size tend to 0) that belong to a same one-parameter family of conformally invariant random curves, the Schramm-Loewner evolution. This stochastic process introduced in 1999 by Schramm has been at the center of many rigorous breakthroughs in statistical mechanics. This talk will be an overview of some of these.

wednesday, may 3, 12:30 p.m.

• Title: Gamma Rays in Globular Clusters
• Speaker: Owen Henry (Physics Department, Brooklyn College)
• Venue: Hybrid (3143 Ingersoll in-person, with refreshments, and Zoom
• Abstract: We associate gamma radiation detected with the Large Area Telescope (LAT) aboard Fermi with a stacked population of 36 high latitude globular clusters (GCs) not detected in the Fermi Point Source Catalog. Using stacking techniques, we detect these sources as a population. GCs typically contain millisecond pulsars (MSPs), because of the high density and advanced age of these systems. We use 13 years of data collected by LAT to search for the cumulative signal from undetected MSPs in GCs. To maximize sensitivity we avoid the complex background of the Galactic plane by selecting a candidate list of 36 targets with Galactic latitude |b| > 20º and are not associated in the Fermi catalog. These sources undergo a standard binned likelihood analysis with fermipy producing a “Test Statistic” (TS) value which identifies the significance of the center of the 21º by 21º region of interest (ROI) as a gamma-ray source. The TS values are stacked and compared against control field (CF) ROIs that undergo the same analysis and stacking procedure as the clusters using a bootstrap resampling method. CFs were selected to match the Galactic longitude distribution of the target GCs. We find that the stacked population of GCs is significantly detected in the TS stack compared to the stack of control fields with a ΔTS ~ 60. We also investigate correlations between the stack luminosity and cluster observables, such as distance, absolute magnitude (i.e., mass), and stellar encounter rate. We also search for evidence of the emission mechanism of gamma-rays either directly from the pulsar or from around it via known high energy photon emission processes such as Inverse Compton scattering.

FALL 2022

Tuesday, October 18, 4:30 p.m. (refreshments from 4 p.m.)

Title: Jung, Pauli and Synchronicity

Speaker: Arthur I. Miller (University College London)

Venue: 2143 Ingersoll Hall and Zoom (hybrid mode)

Abstract: At a key time in his scientific development, the physicist Wolfgang Pauli underwent analysis by Carl Jung. The encounters were inspiring for both men and sparked changes in their work. I will talk about Pauli and how his scientific discoveries were affected by Jung’s analysis of his dreams. At the time, Jung was looking into alchemy, mysticism and the I Ching. How did his encounters with Pauli affect his view of the world and the universe? And what was synchronicity and how did it come into it?

Speaker Biography: Arthur I. Miller is emeritus professor of the history and philosophy of science at University College London. He has written many critically acclaimed books, including the Pulitzer Prize–nominated Einstein, Picasso: Space, Time, and the Beauty that Causes Havoc; 137: Jung, Pauli, and the Pursuit of a Scientific Obsession; and Colliding Worlds: How Cutting-Edge Science is Redefining Contemporary Art. His most recent book is The Artist in the Machine: The World of AI-Powered Creativity (MIT Press, 2019), where he explores AI and creativity in art, literature and music.

Tuesday, November 22, 12:30 p.m.

Title: Hard Ferromagnets as a New Perspective on Materials for Thermomagnetic Power Generation Cycles

Speaker: Karl Sandeman (Brooklyn College and CUNY Graduate Center)

Abstract: We consider the ways in which magnetically hard materials can be used as the working materials in thermomagnetic power generation (TMG) cycles in order to expand the area in the magnetisation versus applied field (M − H ) plane available for energy conversion. There are three parts to this perspective. First, experiments on commercially available hard ferrites reveal that, while these materials are not yet good TMG candidates, hard ferromagnets with higher thermal conductivity and a greater change of magnetization with temperature could outperform existing TMG materials. Second, computational results indicate that biasing a soft magnet with a hard ferromagnet is essentially equivalent to shifting the M − H loop by an amount proportional to the field of the biasing magnet. Work outputs under biased conditions show a substantial improvement over unbiased cycles, but experimental verification is needed. Third, we discuss the rationale for exploring artificial spin reorientation materials as novel TMG working materials.

Tuesday, December 6, 12:30 p.m.

Title: TBC

Speaker: Neno Fuller (Kansas University)

Venue: Zoom only (link TBC)

Abstract: TBC.

More Information

All colloquia are via Zoom. Please direct any enquiries to Karl Sandeman.