FALL SEMESTER
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"Ramanujan's Perpetual Impact on Mathematics" Kağan Kurşungöz We will tell the short and sad life story of the Indian genius Srinivasa Ramanujan, and the impact of his mathematics on the 20th century mathematics and beyond. We will give mathematical examples as time allows. Examples will include continued fractions, integer partitions, q-series, etc. The exposition will be elementary and the talk will be accessible to a general audience. Please bring pencil and paper to do some simple calculations.
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“Materials Emitting Light Long After The Sun Goes Down” Cleva W. OW‐YANG Zero energy consumption lighting is an attractive solution for us to live more sustainably with lower carbon consumption. One opportunity is the use of extremely long afterglow pigments in construction materials. To meet this challenge, my research group and team of collaborators have been developing long afterglow ceramic pigments, by elucidating the structural design rules that enable the extreme persistence in afterglow in Eu2+, Dy3+, and boron co‐doped strontium aluminate. While Eu2+ ions are the optically active species with fluorescence decay on the order of milliseconds, co‐doping with Dy3+ results in energy transfer that prolongs afterglow to ca. 10 minutes. The addition of boron dramatically extends this afterglow persistence to > 14 h. In this talk, I will describe our experiments for evaluating a model, in which clustering of the ionic point defects supports the long afterglow duration. Using atomic scale imaging and nanoscale spatially resolved spectroscopy to probe the effect of boron on the microstructural evolution, dopant chemistry, and dopant distribution, our studies reveal directly rare‐earth ion incorporation into adjacent sites in the Sr sub‐lattice and suggest a complex role played by boron. |
“Molecular Biology in the Light of Evolution” Ogün Adebali Evolution is the process that organisms develop from past organisms. Evolutionary processes require molecular changes in the building blocks of life, DNA. Derived from a single common ancestor, organisms share parts of DNA that are critically important for survival. These genetic parts are called conserved regions that are used to infer the fundamental features of life. Today, we directly benefit from this principle to shed light on molecular biology. With carefully compiled evolutionary information along with bioinformatics techniques, we can predict the function, interactions and structure of proteins. More importantly, evolutionary information directly helps people to maintain our wellness, be aware of the risk of genetic syndromes and even diagnose life-threatening diseases including cancer. |
“Born to ride: ancient DNA and the genetics of Mongolians and their horses” Andrew Berry Harvard University Mongolian culture is famously horse-centered, and it has long been assumed that horses were domesticated in Central Asia from a stock of wild horses related to the last remaining wild horse, Przewalski's horse. Recent studies, however, of ancient DNA derived from horse bones found at archeological sites have overturned this idea. These analyses suggest that there were at least two independent domestications of horses, and that Przewalski's horses in fact constitute a feral population of a previously domesticated breed of horses. Independent of the specifics of the history of horse domestication, one aspect of the relationship between Mongolians and their horses is central of the history of the Mongolian empire: horses were critical to the extraordinary success and extent of Mongolian military campaigns. This success is reflected in the spread of male DNA markers, on the Y chromosome, that spread throughout Eurasia over the period of Mongol dominance. It is even suggested that a particularly prominent and common Y chromosome lineage was derived from Genghis Khan himself. Together, horse and human DNA give a fascinating insight into an extraordinary phase of history, illustrating how scientific approaches can complement archeological and anthropological ones in our attempt to understand the past. |