School of Humanities and Sciences
Showing 1-20 of 20 Results
Paul S. and Billie Achilles Professor in Environmental Biology, Senior Fellow at the Woods Institute for the Environment and Professor, by courtesy, of Geological Sciences
Current Research and Scholarly InterestsElizabeth Hadly and her lab probe how perturbations such as climatic change and human modification of the environment influence the evolution and ecology of animals.
Philip C. Hanawalt
Dr. Morris Herzstein Professor in Biology, Emeritus
Current Research and Scholarly InterestsMy current interest includes two principal areas:
1. The molecular basis for diseases in which the pathway of transcription-coupled DNA repair is defective, including Cockyne syndrome (CS) and UV-sensitive syndrome (UVSS). Patients are severely sensitive to sunlight but get no cancers. See Hanawalt & Spivak, 2008, for review.
2. Transcription arrest by guanine-rich DNA sequences and non-canonical secondary structures. Transcription collisions with replication forks.
Professor of Applied Physics, Emeritus
Current Research and Scholarly InterestsTheory of metal-semiconductor interfaces and field-effect transistors
Associate Professor of Physics
BioI am a theorist working on problems in gravitational, high energy and condensed matter physics. In recent years the holographic correspondence, the physics of quantum entanglement and quantum field theory more generally have led to strong connections between central concerns in these different fields.
For example, I am interested in understanding the emergence of spacetime from large N matrix quantum mechanics models. These can be thought of as the simplest models of holographic duality, and will likely hold the key to understanding the emergence of local physics as well as black holes. The most basic object in these theories is the ground state wavefunction. Understanding this wavefunction is a many-body problem and I am interested in using modern ideas from condensed matter theory -- such as topological order -- to characterize it.
Another example has to do with dissipation. How quickly can a quantum mechanical system thermalize itself? From this perspective, there are remarkable similarities between strongly quantum mechanical systems such as the quark-gluon plasma and high temperature superconductors and the dynamics of black holes in classical gravity. This may suggest that a fundamental limitation imposed by quantum statistical mechanics is at work in these systems. I have pursued this possibility from many angles, including variational principles for entropy production, the Lieb-Robinson bound on velocities in quantum systems and bounds on the magnitude of quantum fluctuations near thermal equilibrium.
In parallel to a ''bird's eye'' approach to quantum statistical mechanics, I am also increasingly interested in specific scattering mechanisms in unconventional materials that may give a relatively simple explanation of transport behavior that has otherwise been considered anomalous --- using this approach my collaborators and I have 'demystified' aspects of transport in quantum critical ruthenate materials. I am currently interested, for example, in the role of phonons in strongly correlated electronic systems.
I have recently worked on black hole interiors in classical gravity. Black hole interiors are extremely rich mathematically, but their physical interpretation -- for example in a holographic context -- remains obscure. To start to address this question I have shown how important dynamics of the interior, such as the instability of the singularity and of Cauchy horizons, can be triggered in a relatively simple holographic setting.
Lists of my publications and of recorded talks and lectures can be found following the links on the right.
John A. Overdeck Professor, Professor of Statistics and of Biomedical Data Sciences
Current Research and Scholarly InterestsFlexible statistical modeling for prediction and representation of data arising in biology, medicine, science or industry. Statistical and machine learning tools have gained importance over the years. Part of Hastie's work has been to bridge the gap between traditional statistical methodology and the achievements made in machine learning.
Stanford Professor of Quantum Physics and Professor, by courtesy, of Computer Science
BioProfessor Hayden is a leader in the exciting new field of quantum information science. He has contributed greatly to our understanding of the absolute limits that quantum mechanics places on information processing, and how to exploit quantum effects for computing and other aspects of communication. He has also made some key insights on the relationship between black holes and information theory.
Professor of Applied Physics and of Photon Science and, by courtesy, of Electrical Engineering
Current Research and Scholarly InterestsElectronic properties and dynamics of nanoscale materials, ultrafast lasers and spectroscopy.
H. Craig Heller
Lorry I. Lokey/Business Wire ProfessorOn Leave from 01/01/2021 To 06/30/2021
Current Research and Scholarly InterestsNeurobiology of sleep, circadian rhythms, regulation of body temperature, mammalian hibernation, and human exercise physiology. Currently applying background in sleep and circadian neurobiology the understanding and correcting the learning disability of Down Syndrome.
David Mulvane Ehrsam and Edward Curtis Franklin Professor of Chemistry and Professor of Photon Science at SLAC
BioCombining inorganic, biophysical and structural chemistry, Professor Keith Hodgson investigates how structure at molecular and macromolecular levels relates to function. Studies in the Hodgson lab have pioneered the use of synchrotron x-radiation to probe the electronic and structural environment of biomolecules. Recent efforts focus on the applications of x-ray diffraction, scattering and absorption spectroscopy to examine metalloproteins that are important in Earth’s biosphere, such as those that convert nitrogen to ammonia or methane to methanol.
Keith O. Hodgson was born in Virginia in 1947. He studied chemistry at the University of Virginia (B.S. 1969) and University of California, Berkeley (Ph.D. 1972), with a postdoctoral year at the ETH in Zurich. He joined the Stanford Chemistry Department faculty in 1973, starting up a program of fundamental research into the use of x-rays to study chemical and biological structure that made use of the unique capabilities of the Stanford Synchrotron Radiation Lightsource (SSRL). His lab carried out pioneering x-ray absorption and x-ray crystallographic studies of proteins, laying the foundation for a new field now in broad use worldwide. In the early eighties, he began development of one of the world's first synchrotron-based structural molecular biology research and user programs, centered at SSRL. He served as SSRL Director from 1998 to 2005, and SLAC National Accelerator Laboratory (SLAC) Deputy Director (2005-2007) and Associate Laboratory Director for Photon Science (2007-2011).
Today the Hodgson research group investigates how molecular structure at different organizational levels relates to biological and chemical function, using a variety of x-ray absorption, diffraction and scattering techniques. Typical of these molecular structural studies are investigations of metal ions as active sites of biomolecules. His research group develops and utilizes techniques such as x-ray absorption and emission spectroscopy (XAS and XES) to study the electronic and metrical details of a given metal ion in the biomolecule under a variety of natural conditions.
A major area of focus over many years, the active site of the enzyme nitrogenase is responsible for conversion of atmospheric di-nitrogen to ammonia. Using XAS studies at the S, Fe and Mo edge, the Hodgson group has worked to understand the electronic structure as a function of redox in this cluster. They have developed new methods to study long distances in the cluster within and outside the protein. Studies are ongoing to learn how this cluster functions during catalysis and interacts with substrates and inhibitors. Other components of the protein are also under active study.
Additional projects include the study of iron in dioxygen activation and oxidation within the binuclear iron-containing enzyme methane monooxygenase and in cytochrome oxidase. Lab members are also investigating the role of copper in electron transport and in dioxygen activation. Other studies include the electronic structure of iron-sulfur clusters in models and enzymes.
The research group is also focusing on using the next generation of x-ray light sources, the free electron laser. Such a light source, called the LCLS, is also located at SLAC. They are also developing new approaches using x-ray free electron laser radiation to image noncrystalline biomolecules and study chemical reactivity on ultrafast time scales.
Professor (Research) of Physics
BioHow can we make optimal use of quantum systems (atoms, lasers, and electronics) to test fundamental physics principles, enable precision measurements of space-time and when feasible, develop useful devices, sensors, and instruments?
Professor Hollberg’s research objectives include high precision tests of fundamental physics as well as applications of laser physics and technology. This experimental program in laser/atomic physics focuses on high-resolution spectroscopy of laser-cooled and -trapped atoms, non-linear optical coherence effects in atoms, optical frequency combs, optical/microwave atomic clocks, and high sensitivity trace gas detection. Frequently this involves the study of laser noise and methods to circumvent measurement limitations, up to, and beyond, quantum limited optical detection. Technologies and tools utilized include frequency-stabilized lasers and chip-scale atomic devices. Based in the Hansen Experimental Physics Laboratory (HEPL), this research program has strong, synergistic, collaborative connections to the Stanford Center on Position Navigation and Time (SCPNT). Research directions are inspired by experience that deeper understanding of fundamental science is critical and vital in addressing real-world problems, for example in the environment, energy, and navigation. Amazing new technologies and devices enable experiments that test fundamental principles with high precision and sometimes lead to the development of better instruments and sensors. Ultrasensitive optical detection of atoms, monitoring of trace gases, isotopes, and chemicals can impact many fields. Results from well-designed experiments teach us about the “realities” of nature, guide and inform, occasionally produce new discoveries, frequently surprise, and almost always generate new questions and perspectives.
Professor of Statistics
Current Research and Scholarly InterestsOur lab has been developing tools for the analyses of complex data structures, extending work on multivariate data to structured multitable table that include graphs, networks and trees as well as categorical and continuous measurements.
We created and support the Bioconductor package phyloseq for the analyses of microbial ecology data from the microbiome. We have specialized in developing interactive graphical visualization tools for doing reproducible research in biology.
Professor of Chemistry, Emerita
BioProfessor Wray Huestis’ research concerns the molecular mechanisms whereby cells control their shape, motility, deformability and the structural integrity of their membranes. Metabolic control of interprotein and protein-lipid interactions is studied by a variety of biochemical, spectroscopic and radiochemical techniques, including fluorescence and EPR spectrometry, autoradiography and electron microscopy. The role of lipid metabolism and transport in regulating the fluid dynamics of cell suspensions (red blood cells, platelets, lymphocytes) is examined using circulating cells and cells grown in culture. Cell-cell and cell-liposome interactions are studied using model membrane systems with widely differing physical properties. Complexes of liposomes and encapsulated viruses are used as selective vectors to deliver water-soluble compounds across the membranes of intact cells. The particular projects described in the listed publications have as a common goal an understanding of the molecular workings of the cell membrane.