黑料社

Emergent Challenges and Opportunities in Higher Education

Abstract:

After decades of stability, growth, and a certain level of success with a model where instructors served as the primary knowledge source while most students passively listened, teaching and learning in higher education have been in a state of constant evolution in response multiple societal pressures and technological developments. One of the main challenges encountered in the STEM fields is the modest persistence rate, with only ca. 40-50% of students who declare a STEM major (in the US) ultimately completing their originally intended degree. Some of the reasons frequently cited for students to leave STEM majors include lack of preparedness for rigorous work, insufficient support systems, social and cultural factors, and institutional barriers. This talk will describe efforts to make UCLA faculty aware of many of these issues and to explore the implementation of inclusive education strategies.

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Exciton-Enabled Quantum Chain Amplification in a Crystalline Two-Photon Adiabatic Photocage

Abstract:

Photocages are chemical structures designed to release molecules of interest upon exposure to light. The use of coherent two photon excitation (2PE) using ultra-fast, high-energy femtosecond laser pulses focused in a femtoliter volume at twice the normal excitation wavelength makes it possible to achieve high temporal and spatial resolution in 3D, which is extremely valuable for applications in biology and materials science. However, as the total number of molecules excited under these conditions is extremely small, applications must rely on ultra-sensitive detection, such as 2PE fluorescence microscopy where it is possible to detect single photons. This contribution will describe an amplification concept based on the use of adiabatic photocages capable of entering a quantum chain reaction where hundreds of product molecules can be obtained from a single 2PE event. This is demonstrated with a novel adiabatic Dewar benzene photocage where 2PE provides the initiation step for a triplet exciton-enabled quantum chain that releases ca. 400 molecules of 7-hydroxycoumarin. The latter serve both as 2PE antenna and as a 2PE fluorophore to determine and optimize the experimental parameters needed to construct 3D microscopy images.

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Bio:

Miguel A. Garc铆a-Garibay received his B.S. degree from the University of Michoacan, Mexico and his Ph.D. from the University of British Columbia with Professor John Scheffer. After his time as a postdoctoral fellow at Columbia University, he joined the Department of Chemistry and Biochemistry at UCLA, where he is now Distinguished Professor. After various leadership positions, he was appointed Dean of Physical Sciences and Senior Dean of the UCLA College. He has served in editorial boards of several American Chemical Society and the Royal Society of Chemistry journals and was an associate editor of Journal of the American Chemical Society. Garc铆a-Garibay achieved international reputation for work in reactive intermediates, solid-state chemistry, photochemistry, and for the development of amphidynamic crystals as a platform for molecular machines. He has authored over 250 articles and delivered over 350 lectures across the globe. Among other honors, he received the Inter-American Photochemical Society Award, the ACS Cope Scholar Award, and the 2025 ACS James Flack Norris Award in Physical Organic Chemistry. He was elected fellow of the American Association of the Advancement of Science, fellow of the American Chemical Society, member of the American Academy of Arts and Sciences, corresponding member of the Mexican Academy of Sciences, and in 2023, he was elected to the USA National Academy of Sciences.