School of Humanities and Sciences

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  • Justin Du Bois

    Justin Du Bois

    Henry Dreyfus Professor of Chemistry and Professor, by courtesy, of Chemical and Systems Biology

    BioResearch and Scholarship

    Research in the Du Bois laboratory spans reaction methods development, natural product synthesis, and chemical biology, and draws on expertise in molecular design, molecular recognition, and physical organic chemistry. An outstanding goal of our program has been to develop C–H bond functionalization processes as general methods for organic chemistry, and to demonstrate how such tools can impact the logic of chemical synthesis. A second area of interest focuses on the role of ion channels in electrical conduction and the specific involvement of channel subtypes in the sensation of pain. This work is enabled in part through the advent of small molecule modulators of channel function.

    The Du Bois group has described new tactics for the selective conversion of saturated C–H to C–N and C–O bonds. These methods have general utility in synthesis, making possible the single-step incorporation of nitrogen and oxygen functional groups and thus simplifying the process of assembling complex molecules. To date, lab members have employed these versatile oxidation technologies to prepare natural products that include manzacidin A and C, agelastatin, tetrodotoxin, and saxitoxin. Detailed mechanistic studies of metal-catalyzed C–H functionalization reactions are performed in parallel with process development and chemical synthesis. These efforts ultimately give way to advances in catalyst design. A long-standing goal of this program is to identify robust catalyst systems that afford absolute control of reaction selectivity.

    In a second program area, the Du Bois group is exploring voltage-gated ion channel structure and function using the tools of chemistry in combination with those of molecular biology, electrophysiology, microscopy and mass spectrometry. Much of this work has focused on studies of eukaryotic Na and Cl ion channels. The Du Bois lab is interested in understanding the biochemical mechanisms that underlie channel subtype regulation and how such processes may be altered following nerve injury. Small molecule toxins serve as lead compounds for the design of isoform-selective channel modulators, affinity reagents, and fluorescence imaging probes. Access to toxins and modified forms thereof (including saxitoxin, gonyautoxin, batrachotoxin, and veratridine) through de novo synthesis drives studies to elucidate toxin-receptor interactions and to develop new pharmacologic tools to study ion channel function in primary cells and murine pain models.

  • John Duchi

    John Duchi

    Associate Professor of Statistics, of Electrical Engineering and, by courtesy, of Computer Science

    Current Research and Scholarly InterestsMy work spans statistical learning, optimization, information theory, and computation, with a few driving goals: 1. To discover statistical learning procedures that optimally trade between real-world resources while maintaining statistical efficiency. 2. To build efficient large-scale optimization methods that move beyond bespoke solutions to methods that robustly work. 3. To develop tools to assess and guarantee the validity of---and confidence we should have in---machine-learned systems.

  • Christopher M. Dundas

    Christopher M. Dundas

    Postdoctoral Scholar, Biology

    Current Research and Scholarly InterestsSoil can have an enormous impact on climate change mitigation, as atmospheric CO2 is captured and stored in large quantities by soil organic matter. Plants mediate carbon sequestration by transferring aboveground photosynthesis products to belowground roots. This carbon is stabilized into soil pools by root growth/biomass turnover, exudation of organic compounds, and metabolization by soil microbes. Crops bioengineered to increase soil carbon input could boost net CO2 capture and improve agricultural productivity (e.g., via elevated water and nutrient availability). However, genetic engineering targets that control carbon exchange from roots to soil remain poorly defined. Since carbon distribution within plants is controlled by sugar metabolization and transport, genes that alter these processes may also regulate carbon input to root-proximal soil (i.e., the rhizosphere). At Stanford, Christopher will study how these genes affect soil carbon input by Setaria viridis, a model energy grass that is a promising sustainable fuel source. Leveraging high throughput root imaging technology and genetic circuit design, he will construct root-associating bacterial strains and transgenic Setaria that allow researchers to measure/modulate sugar flux from root systems. These living sensors/actuators will be used to determine genetic design rules of soil carbon input at the root-rhizosphere interface. Results will inform engineering of biofertilizer bacteria and functional plant genes that can increase carbon release into soils by other food- and energy-relevant crops.