Anish Ghosh receives the 2021 Shanti Swarup Bhatnagar Prize

December 16, 2021 By

Anish Ghosh has received the 2021 Shanti Swarup Bhatnagar Prize in Mathematical Sciences. The Shanti Swarup Bhatnagar Prize is India’s highest science award within the country. While at Brandeis, Anish Ghosh was the student of Dmitry Kleinbock, Professor of Mathematics. He is currently a faculty member at the Tata Institute of Fundamental Research (TIFR), Mumbai where he specializes in Ergodic Theory and Number Theory.

Kleinbock wrote the following about his former student:

“It was a great pleasure to find out that Anish Ghosh, my former student here at Brandeis, has received the Shanti Swarup Bhatnagar prize. Anish is a talented mathematician working in the field of ergodic theory on homogeneous spaces. Interest in this field rose significantly during the late 1980s and early 1990s after the seminal achievements of Marina Ratner and Anish’s mathematical grandfather Gregory Margulis, whose work, in particular the proof of the Oppenheim Conjecture, has since served as a basis for numerous links between dynamics and number theory.”

“Anish has been exploring connections between the two fields throughout his mathematical career. Since his graduation in 2006 he has authored more than 40 papers, many published in top-level journals, and has become one of a few people who are shaping the subject of ergodic theory and its arithmetical applications. Among his notable achievements I can mention the work on distribution of dense lattice orbits in homogeneous spaces, on intrinsic Diophantine approximation, on applications of equidistribution to counting lattice points and – most recently – an approach to quantitative Oppenheim-type problems involving Rogers’ moment formulas.”

“Anish has also been a great mentor, who as of now has produced at least 8 PhD students and collaborated with them extensively on various problems. He has lectured extensively on the subject of connections of dynamics and number theory and edited several collections of papers. To summarize, the Bhatnagar Prize is well deserved, and I am positive that the mathematical talent of Anish Ghosh will continue to flourish.”

Filed Under: awards, division of science, division of science, labs, Mathematics Tagged With: , , ,

Schmidt-Rohr examines why plants need two different photosystems

December 15, 2021 By

In a recent paper in Life (Basel), Klaus Schmidt-Rohr, Professor of Chemistry, introduces a self-explanatory description of the energetics of photosynthesis in plants, the so-called EZ-scheme. It shows the energies of molecules in kJ/mol instead of the classical Z-scheme’s shifted energy differences that are misleadingly encrypted in volts. Unlike its predecessor, the EZ-scheme includes the Kok cycle in the water-splitting complex, charge separation after photon absorption, and the Calvin cycle with carbohydrate synthesis (in a simplified form). It also shows O2 correctly as a high-energy product, due to its relatively weak double bond, and demonstrates that Photosystem II pumps more of the absorbed photon energy into O2 than into the plant.

This paper provides the first valid explanation of why plants need two different photosystems: PSII mostly extracts hydrogen (as protons plus electrons) from H2O, producing PQH2 (plastoquinol), and generates the energetically expensive product O2, providing little energy directly to the plant. PSI is needed to produce significant chemical energy for the organism, in the form of ATP, and to generate a less reluctant hydrogen donor, NADPH. This work fundamentally revises received notions of the energetics of photosynthesis, by pointing out the classical Z-scheme’s bewildering implication that H2O gives off electrons spontaneously to chlorophyll while releasing energy, and by showing that the concept of energy transport by “high-energy electrons” in photosynthesis is misguided, since energy and electrons flow in opposite directions.

Figure #1 from Schmidt-Rohr paper

Figure 1 Simplified EZ-scheme of the energetics of photosynthesis in plants, converting H2O and CO2 to O2 and carbohydrate, [CH2O]. The direction of energy transfer and release is indicated by straight red arrows at the top, formal hydrogen transfer by blue dashed curved arrows at the bottom of the diagram. Three dots … indicate omitted redox reactions.

Schmidt-Rohr K. O2 and Other High-Energy Molecules in Photosynthesis: Why Plants Need Two Photosystems. Life (Basel). 2021 Nov 5;11(11):1191.

Filed Under: chemistry, division of science, labs Tagged With: , ,

Han paper describes electrochemical switching of arylazopyrazole & heat release

December 8, 2021 By

Research image from paperMihael Gerkman and Prof. Grace Han in the Department of Chemistry report the first demonstration of redox-induced energy release from molecular solar thermal (MOST) compounds in condensed phases, in collaboration with a team of Prof. Matthew Fuchter at Imperial College London. MOST compounds that utilize light-induced chemical isomerization for harnessing solar photon energy have emerged as an alternative to photovoltaics and artificial photosynthesis, enabling a closed-system solar photon energy storage and controlled release. Despite the discovery of various photoswitch systems that show improved photon energy storage efficiencies, the efficient and complete energy release from such photoswitches has remained a major challenge.

This work describes electrochemically-induced switching of arylazopyrazole-based photoswitches. The switching itself is electrocatalytic, requiring only a substoichiometric amount of charge, and its efficiency is improved by over an order of magnitude in the condensed phase compared to in solution. Moreover, electrochemically-induced switching affords a significantly higher completeness of switching than what could be achieved photochemically, which addresses the critical limitation of various azoheteroarene-based MOST materials. We envision that this work will promote exploration of the use of an electrical trigger for MOST material applications for a wide variety of photoswitches.

Jake L. Greenfield‡, Mihael A. Gerkman‡, Rosina S. L. Gibson, Grace G. D. Han*, and Matthew J. Fuchter* J. Am. Chem. Soc. 2021, 143, 37, 15250–15257. (‡ equal contributions) Publication Date: September 14, 2021.

Filed Under: chemistry, division of science, labs Tagged With: , ,

Divisional Prize Instructors design & teach new classes

December 7, 2021 By

The University Prize Instructorships have been a great opportunity for our graduate students to gain experience designing and teaching their own class, and a great opportunity for our undergraduates to engage in learning new areas with a great instructor. When the UPIs were put on hiatus during the pandemic, the Division of Science stepped in to keep this opportunity going for our community. We are really excited for the new courses that will be taught by Xin Yao Lin and Narges Iraji in the Spring 2022 semester- “Science versus Science Fiction” by Narges Iraji, and “Technology Use and Well-Being: Multidisciplinary Perspectives”.

Xin Yao Lin

Xin Yao LinI am very honored and delighted to receive the Divisional Prize Instructorship. I am currently a 5th-year psychology PhD student and I will be teaching a psychology course entitled “PSYC 55B: Technology Use and Well-Being: Multidisciplinary Perspectives” in the spring of 2022. The increase in technology use is changing how we connect, feel, and act. We are relying on technology more than ever, but whether the increased usage of technology is beneficial or detrimental to well-being has been controversial. Drawing on perspectives from psychology, neuroscience, computer-human interaction, and public health, this course explores the positive and negative impact of technology usage on our well-being across the lifespan. We will examine technology use in computer-mediated communication (e.g., smartphone, social media, internet, social apps), mHealth and telehealth, gaming, and other technology trends (e.g., Artificial intelligence, robots, virtual reality), and will explore how these technologies influence social life, adult development and aging, and health/health behavior (e.g., physical activity, diet, sleep).

I am very thankful for this opportunity provided by the Division of Science, and for my mentors and peers who have provided feedback and supported me along the way. I look forward to teaching this course and engaging students with how technology influences our social life, how we develop and age, and our health/health behavior.

Narges Iraji

Narges IrajiThe course Science and Science Fiction, designed for students with little to no science or math background, encourages conversations around science within the context of culture. Reading the works of science fiction by a diverse group of authors and discussing the science and imagination in them illuminates the inseparability of science from its human nature. I hope that this approach not only bridges the materials taught in class and the outside world but also sparks a curiosity that goes beyond the classroom.

Our inner urge to observe, decode patterns, and predict has existed well past the modern times and so has our passing of knowledge to the future in the form of storytelling. The combination of imagination and science is nothing new but the access to both, who can imagine and who can be a scientist, has changed throughout history. During the course, the students will read, discuss, and write about science fiction stories that inspire questions and problems which call for mathematical modeling. After becoming more familiar with some well-known mathematical models in areas such as population modeling and epidemiology, the students start working on a final project. They will formulate a question related to what they are passionate or curious about and pursue the answer using the tools that they have gained from the course. The goal is not to solve the problem, but to gain some insight into the steps required in doing so.

Teaching a University Prize Instructorship course has been a dream of mine since I heard about this opportunity in my first or second year. I am grateful for this, and thankful to all those who are helping me along the way. Numerous challenges follow developing a course, and while being one of the greatest projects that I have taken on, it has tested my patience a few times. I hope that after serving as a University Prize Instructorship instructor, I can help other graduate students who are interested in this opportunity by sharing some resources, such as information on inviting speakers or reserving classrooms with computers. My experience as a graduate student in physics and my research in the field of mathematical biology have truly led me to a new perspective. I now look around and find questions in all that I observe knowing someone else might have already started working on the answer. The course, Science and Science Fiction, encapsulates one of my attempts to pass this curiosity about the universe and life forward.

Filed Under: awards, division of science, grad students, labs, Neuroscience, Physics, Psychology Tagged With: , , , , ,

Brandeis Receives Grant to Further Collaboration with Hampton University

December 6, 2021 By

Irving EpsteinIn collaboration with Hampton University, an historically Black institution in Hampton, VA, Brandeis has received a $250,000 grant from the Alfred P. Sloan Foundation’s Equity-Minded Pathways to STEM Graduate Education program to create a route for Hampton students to enroll in masters degree programs at Brandeis. The program will comprise summer research internships at Brandeis for Hampton juniors and a senior-year course at Hampton jointly developed and taught by Brandeis and Hampton faculty, as well as cohort-based mentoring during the students’ masters study.  It extends the existing Brandeis-Hampton collaboration associated with our Materials Research Science and Engineering Center (MRSEC) and will be led by Profs. Irving Epstein at Brandeis and Demetris Geddis at Hampton.

Filed Under: awards, chemistry, division of science, division of science, General, grad students, outreach, Uncategorized Tagged With: , ,

Grace Han Receives Young Investigator Award

November 12, 2021 By

Grace HanGrace Han, Landsman Assistant Professor of Chemistry, has received a Young Investigator Research Program award from the Air Force Office of Scientific Research (AFOSR). The award will support her research on the optically-controlled catalyst recycling for 3 years.

Catalysis is one of the core processes in chemical industry and essential for achieving many products critical to the Department of Defense’s mission – from medicines to counter threats, to radiation-resistant polymeric coatings, and advanced fuels for aircraft. Catalysts are the key components that serve to improve reaction rates and product yields, and these costly compounds are generally disposed after one use. Various concepts for catalyst recycling, particularly using fluorous biphasic systems, have been developed to achieve cost-effective and sustainable synthetic procedures. However, the heating and cooling steps employed in the recycling process are only compatible with a limited scope of reactions and solvents.

To address this challenge, the Han group is developing a new class of biphasic catalysts that are optically activated, or precipitated, at a constant temperature by the incorporation of a photoswitch unit in the catalyst structure. Photoswitches are novel organic molecules that respond to light by changing their shape and physical properties including polarity. The significant shape and polarity change of the photoswitch unit will drastically change the solubility of catalysts in an organic solvent, which regulates the activity and recovery of catalysts. This new method of catalyst recycling is anticipated to reduce the costs as well as environmental impact of the conventional use of catalysts in various industries.

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