2024 Stanford Doerr Discovery Grants

Developing a bacterial key to unlock the functional diversity of fungal symbioses

PI: Kabir Peay, Associate Professor of Biology, of Earth System Science, and Senior Fellow at the Woods Institute for the Environment
Fungi form a cooperative partnership, known as mycorrhizal symbiosis, with the roots of most plants on Earth. Single trees can associate with hundreds of fungal species, and these partnerships change over time and space to meet environmental challenges. Our capacity to understand and harness this diversity is limited, however, by the simple fact that we cannot easily grow most mycorrhizal fungi. Our project tests the new hypothesis that a missing partner – symbiotic bacteria we isolated from mycorrhizal roots – can overcome the culture barrier, improving our understanding of fungal biodiversity and opening new avenues to meet conservation and restoration goals.

Seeing Earth’s Archean atmosphere through a grain of (extraterrestrial) sand

PI: Mathieu Lapôtre, Assistant Professor of Earth and Planetary Sciences
Our atmosphere is the result of billions of years of interactions between our planet and life. In fact, it has changed so much that we do not know what it was like before life first evolved. Thanks to this grant, we will use our planet’s neighbor – Mars – as a time machine. We recently discovered that a unique type of windblown sand dune can form under Mars’ thin atmosphere. Our goal will be to search for similar (but fossil) dunes in some of Earth’s oldest rocks and attempt to quantify Earth’s atmospheric pressure before the advent of complex life.

Following water through ice shells with radar by bridging hydrologic permeability and dielectric permittivity

PI: Dustin Schroeder, Associate Professor of Geophysics, of Electrical Engineering, and Senior Fellow at the Woods Institute for the Environment
The transport of water through the icy shell of Jupiter’s moon Europa is thought to be important for its potential to support life. Radar instruments on upcoming missions to Europa are sensitive to the presence of water, which modifies the dielectric permittivity of the ice shell. Dustin Schroeder and postdoctoral scholar Natalie Wolfenbarger aim to bridge the gap between hydrologic permeability and dielectric permittivity through a proof-of-concept study exploring the feasibility of concurrent measurements. This innovative approach promises to enhance our understanding of how geophysical tools can be used to probe Europa’s potential habitability.

Mitigating uncertainty in the radiative forcing by stratospheric aerosol injection for solar geoengineering in a multiscale modeling framework

PI: Yuan Wang, Assistant Professor of Earth System Science
Different solar radiation management (SRM) strategies have been evaluated to avert catastrophic shifts in our climate system, among which stratospheric aerosol injection (SAI) receives the most attention compared to the other methods. This project utilizes satellite observations and multiscale climate models with the regional refinement capability to understand the uncertainty associated with convective transport processes on the stratospheric water vapor and aerosols in the hypothetical SAI geoengineering experiments. This project targets fundamental scientific questions on the relationship between atmospheric water vapor and aerosols, dynamical processes, and Earth’s radiation balance, aiming to reduce the uncertainty of the SAI efficiency assessments.

Did early eukaryotes starve their way into multicellularity?

PI: Erik Sperling, Associate Professor of Earth and Planetary Sciences and Senior Fellow at the Woods Institute for the Environment
Recent paleontological discoveries indicate that multiple origins of multicellularity were clustered in time between ~1050–850 million years ago. This proposal tests a new hypothesis for the origins of multicellularity – rather than being limited by the environment, eukaryotic multicellularity was a solution to low food supply in this interval. The project will produce new geochemical and paleontological data from the critical time period, test the temporal correlation of primary productivity and multicellularity with a statistical database approach, and generate preliminary data and optimized lab protocols to test the growth and survival of body plan analogues for single- and multicellular animal ancestors.

Deep learning ice dynamics

PI: Ching-Yao Lai, Assistant Professor of Geophysics 
Predicting sea levels for the next century remains a major challenge for climate scientists and policymakers. However, the fundamental flow law of glacial ice has never been validated at the ice-shelf scale. Here, we will take advantage of recent advances in physics-informed deep learning to learn the fundamental constitutive ice flow law from observational data. In physics-informed deep learning a neural network is trained based not only on empirical ice-sheet data but also on the governing physical principles (e.g., conservation of mass and momentum). This approach provides an opportunity to reveal unknown physical laws and build better climate predictions.

Unveiling the fracture mechanics of earthquake ruptures and ice shelf rifting using geophysical inversions

PI: Eric Dunham, Professor of Geophysics
Geophysical inversions are used to determine Earth structure and dynamics from geophysical measurements by adjusting model parameters to minimize misfit between model predictions and geophysical observations. This project will develop the mathematical and computational framework, using the adjoint method for gradient calculation, for two inverse problems: 1) monitoring ice shelf structure, including growth of rifts and crevasses, from seismic measurements of the vibrational response of ice shelves to ocean waves and tides; 2) constraining fault friction and stresses that govern the nucleation, propagation, and arrest of earthquakes using seismic and geodetic data.

Identification and characterization of novel bacterial cholesterol-interacting proteins

PI: Paula V. Welander, Associate Professor of Earth System Science
This proposal will explore a new area in sterol lipid biology that focuses on characterizing all the cholesterol-binding proteins – the cholesterol interactome – in bacteria using proteomic approaches. Cholesterol is a ubiquitous and essential component of eukaryotic life with important roles in intra- and intercellular signaling, stress tolerance, maintaining cell membrane integrity, and human disease. However, the physiological significance of sterol lipids like cholesterol in bacterial cells is much less understood. This work has the potential to provide insight into novel bacterial protein-cholesterol interactions that can reveal new fundamental biochemical, regulatory, or transport mechanisms.

Will ocean acidification lead to less nutritious seafood?

PIs: Fiorenza Micheli, Professor of Oceans and Senior Fellow at the Woods Institute for the Environment; Giulio De Leo, Professor of Oceans, of Earth System Science, and Senior Fellow at the Woods Institute for the Environment
Aquatic or “blue” foods from fisheries and aquaculture provide a critically important source of macro and micronutrients that support childhood development and adult health for billions of people. Yet, increased atmospheric carbon dioxide is predicted to change ocean environments by making seawater more acidic, which may result in less nutrient-dense seafood and present a challenge for human communities that rely on seafood for food and nutritional security. We are employing a novel approach that leverages a natural model system for future acidified oceans at Ischia Island, Italy, and merges marine and nutrition science methods to produce the first field assessment of the impact of ocean acidification on nutritional content of blue foods and its consequences for ecosystems and for human nutrition.

Deciphering the net impact of globally abundant nitrifying archaea on greenhouse gas warming

PIs: Christopher Francis, Professor of Earth System Science, of Oceans, and Senior Fellow at the Woods Institute for the Environment; Anne Dekas, Assistant Professor of Earth System Science
Ammonia oxidation is a key branch of the global nitrogen cycle and a major source of nitrous oxide (N2O). Ammonia-oxidizing microorganisms are autotrophs, meaning they are also a sink for carbon dioxide (CO2). This project will explore the extent to which CO2 fixation by ammonia-oxidizing archaea (AOA) offsets the greenhouse gas impacts of N2O production by the same organisms. This will be accomplished by coupling measurements of N2O production, CO2 fixation, and nitrification in laboratory cultures of AOA as well as natural samples. Our findings will provide critical missing information regarding the net impact of archaeal nitrification on oceanic greenhouse gas emissions.

An animal-attached multispectral sonar system to quantify the size, abundance, and distribution of zooplankton – Earth’s most important organisms for global carbon and nutrient cycling

PI: Jeremy Goldbogen, Associate Professor of Oceans
An important aspect of the ocean that drives the distribution of life and global biogeochemical processes is that the average density of nutrients and resources is low. Marine organisms cannot survive on the food available at average densities, yet the oceans are teeming with life. This paradox can be resolved by understanding the heterogeneity of plankton distribution, or patchiness. Ship-based sonar systems have failed to measure plankton patchiness at the most important scales. Therefore, we will develop a miniaturized whale-mounted echosounder to measure plankton dynamics at foraging hotspots.

Elucidating the origin of lunar paleomagnetic records by linking bulk rock magnetic properties with nanoscale electron microscopy

PI: Sonia Tikoo-Schantz, Assistant Professor of Geophysics
Paleomagnetism is used to explore the magnetic histories and internal geodynamical evolution of Earth, the moon, Mars, and asteroids. We are conducting a pilot study that uses transmission electron microscopy and energy dispersive spectroscopy measurements of lunar rocks at the nanoscale to document magnetic mineral grains and assess how their microstructures reflect the nature of magnetization recording (e.g., thermal, chemical precipitation, shock). The overarching goal is to determine whether lunar rocks record original magnetizations from a planetary dynamo magnetic field or whether they may contain shock or thermochemical alteration-related magnetization overprints from alternative field sources (e.g., impact plasma fields).

Probing the metal chemistry of fire-generated nanoparticles

PI: Scott Fendorf, Professor of Earth System Science and Senior Fellow at the Woods Institute for the Environment 
Fire impacts metals within the combustible or associated material and yet receives little attention despite having profound implications on human and ecosystem health. At the heart of our limited understanding is fundamental knowledge on how the composition of the combustible material, combined with heating (degree and duration), impacts metals in dust and smoke. We are therefore examining metal-containing particles emanating from simulated wildfires and coal combustion with a focus on ultrafine particles, known as nanoparticles, which may pose a severe threat to human and ecosystem health.

Ecological basis of plant-pollinator-floral microbe interactions for improved crop production

PIs: Tadashi Fukami, Professor of Biology and of Earth System Science; Giulio De Leo, Professor of Oceans, of Earth System Science, and Senior Fellow at the Woods Institute for the Environment; Scott Fendorf, Professor of Earth System Science and Senior Fellow at the Woods Institute for the Environment 
This project will investigate the ecological relationship between agricultural crop plants, their insect pollinators, and the microorganisms that are found in the plants’ flowers and seeds. Focusing on buckwheat in a countryside landscape in Japan as a case study, the researchers will work with local government officials and agricultural cooperatives to carry out the project. The ecological understanding of beneficial flower- and seed-associated microbes from this project will help to move agriculture away from the conventional heavy use of pesticides and antibiotics toward a more environmentally sustainable future with application of native microbes to ensure stable crop yield.

Measuring gross primary productivity in Earth’s past

PIs: C. Page Chamberlain, Professor of Earth & Planetary Sciences and of Earth System Science; Jon Payne, Professor of Earth & Planetary Sciences and Senior Fellow at the Woods Institute for the Environment
Earth’s biosphere has increased its taxonomic diversity and productivity across life’s 4-billion-year history. The number of taxa across time is well documented, but the history of productivity is unknown. This knowledge gap is so profound that we do not know if productivity increases or decreases with climate warming. We will use triple oxygen isotopes (16O, 17O, 18O) to determine past gross primary productivity (the total amount of carbon fixed in an ecosystem). We exploit the fact that deviations in the rarest oxygen isotope (17O) from mass-dependent fractionation occur in the stratosphere during production of ozone and are related to gross primary productivity.

Modeling failure in Earth materials

PIs: Jenny Suckale, Associate Professor of Geophysics, and Ilenia Battiato, Associate Professor of Energy Science Engineering 
All Earth materials fail. They are part of the eternal, natural cycles of growth and decay that characterize our living planet where failure is a question of when, not if. The goal of this proposal is to move beyond merely describing failure in Earth materials by better understanding how, when, and why failure initiates at the microscale. We posit that a deeper understanding of failure initiation could enable us to better model the consequences of failure at the system scale as manifested in natural hazards or the collapse of engineered structures.