Research

A directory of the current research projects at the Institute.

Rowland Junior Fellows

• Visual Neuroscience - David Cox - (neuroscience)
  We recognize visual objects with such ease that it is easy to overlook what an impressive computational feat this represents. Any given object in the world can cast an effectively infinite number of different images onto the retina, depending on its position relative to the viewer, the configuration of light sources, and the presence of other objects in the visual field. In spite of this extreme variation, biological visual systems are able to effortlessly recognize at least hundreds of thousands of d istinct object classes—a feat that no current artificial system can come close to achieving. Our laboratory seeks to understand the neuronal mechanisms that enable this ability by reverse engineeringsimple biological visual systems. It is our hope that this work leads to both a greater understanding of how our own brains work and to build improved artificial visual systems.



• Chirality & Symmetry - Peer Fischer - (physical chemistry)
  Our research focuses on the interaction of molecules with optical, magnetic, and electric fields. We are interested in a diverse spectrum of phenomena, ranging from light-matter interactions to electromagnetic forces. A specific aim is to develop new experimental methods and instrumentation for the detection of molecules and the separation of enantiomers.



• Chemical Ecology of Parasitic Plant Associations - Kristin Lewis - (biology)
  Parasitic angiosperms are unusual among parasitic organisms in that they and their hosts are in the same order and are very similar physiologically. The comparable physiology of parasite and host enables the parasite to create direct connections with host-plant conductive tissues and cells. Additionally, the host and parasite are influenced by similar endogenous and exogenous physiological cues. I am interested in what kinds of information can be shared across the host-parasite boundary and how this affects both plants' responses to environmental conditions. My research focuses on the use of novel methodology to track transfer of resources and signaling molecules between host and parasite.



• Nanomechanical Sensing - Ozgur Sahin - (applied physics)
  At the molecular level, physical and chemical properties of materials are tightly coupled to the mechanical properties. The potential of mechanics for interacting with matter at the nanoscale has been largely unexplored due to lack of instruments capable of performing mechanical measurements at nanometer length scales. Our research focuses on developing tools and techniques to perform nanomechanical measurements and applying them to problems in materials science, cell biology, and molecular biology.



• Ultracold Rydberg Atoms and Terahertz Spectroscopy - Andrew Speck - (atomic physics)
  The objective of our research is to study the interaction of highly excited, or Rydberg atoms, with unipolar terahertz electromagnetic pulses )half cycle pulses). These systems provide a fascinating regime in which to explore atomic states which exhibit both classical and quantum properties. The first series of experiments in my group will explore the interaction of a train of these pulses with Rydberg atoms. Further research will include the study of the magnetic properties of the half cycle pulse and their effect on atomic systems.



• Plant Patterning Via Active and Latent Stem Cells - Rachel Spicer - (biology)
  Plants are able to regenerate whole body parts like roots and shoots with relative ease because they demonstrate amazing cellular plasticity. Masters of dedifferentiation, plants not only retain pools of stem cells throughout their lives, but also create new stem cells in response to developmental and environmental cues. My primary interest is in the role of parenchyma cells in shaping large woody plants - namely, through their ability to dedifferentiate and generate new meristems in response to wounding, and during the transition to secondary growth. I'm interested in developing molecular and microscopy techniques to study secondary growth, including methods to image live cells in woody tissue.



• Biofunctional Photonics - Frank Vollmer - (applied physics in biology)
  Complex biological systems are increasingly analyzed for the fundamental rules governing the interplay of their more simple functional units. To understand the interaction of such single molecules, genes or cellular self-assemblies in basic circuits, networks or whole cells it is necessary to develop tools with nanoscopic sensitivity and capacity. The aim of this emerging field of nanobioscience is first to understand the laws governing a natural biofunctional unit and second to re-engineer simple systems by combination with existing technologies as biophotonic, biomechanic or biorobotic devices.



• Single-molecule Force Studies - Wesley Wong - (biophysics)
  We are interested in how biological systems work at the nanoscale, and the physical laws that govern their behavior. Our focus is on weak, thermally mediated interactions between and within biological molecules (e.g. base-pairing in nucleic acids, receptor-ligand bonding, protein folding, etc.), and the coupling of these interactions to mechanical force. We are currently developing and applying new techniques, based on optical tweezers and high-resolution optical detection, to study the mechanics and force-driven kinetics of single-molecules.

Rowland Senior Fellows

• Trapped Ion Dynamics - Joel Parks – (physics)
  
  Electron diffraction measurements of isolated, single sized clusters stored in ion traps is being applied to the study of small (n ~10-50 atoms) metal clusters including Aun and Agn. These measurements are directed to better understand and exploit the dependence of catalytic reactivity on cluster structure and temperature. Sensitive methods developed to measure laser-induced fluorescence from <10 trapped ions are being applied to study the dynamics of DNA in gas phase. Temperature dependent measurements demonstrate these methods will be useful to characterize conformational change in gas phase biomolecules. Sequential loss of electrons from trapped DNA anions has been observed for the first time and experiments suggest DNA conformations may be a determining factor.



• Photochemistry and Photobiology - James Foley – (organic chemistry)
  
  Our research interests center on understanding fundamental structure/function relationships pertaining to the photophysics that govern the properties and behavior of organic dyes. We use this knowledge to develop improved chromophores for use in biophysical, biological and medical applications such as single molecule detection, fluorescent reporting and photodynamic therapy. Our approach encompasses nearly every aspect that is essential to such an undertaking including computer-aided design, chemical synthesis and photophysical characterization of target dyes.

Staff Scientists

• Associate Director for Science - Michael Burns – (physics)
  
  Over the years I've participated in a number of, to me, facinating projects. I have found no particular common thread other than simple curiousity coupled with an opportunity to indulge that curiousity, and equally curious colleagues. Some of the current and past projects are described herein.



• Electronics Engineering - Winfield Hill – (technology)
  
  The Electronics Engineering Laboratory pursues R & D projects that push the envelope of scientific instrumentation. We do this by applying technologies from diverse fields to create unique instruments, and by learning and applying advanced circuit-design knowledge to endow otherwise common-place instruments with superior performance.



• Computation - Alan Stern – (mathematics)

Affiliated Harvard Faculty

• Bacterial Motility and Behavior - Howard Berg – (biophysics)
  
  The Berg lab at Rowland is a branch of Howard Berg's lab at the Department of Molecular and Cellular Biology on the main Harvard campus. It investigates bacterial motility and chemotaxis using video, fluorescence, and electron microscopy. The chief target of research is the bacterium Escherichia coli, with topics ranging from the hydrodynamics of swimming with flagella to a phenomenological description of chemotactic movement to studies of the biochemical networks that allow E. coli to perform chemotaxis. Recent work includes imaging of pili-mediated twitching motility in Pseudomonas aeruginosa, high-speed video imaging of flagellar filaments during E. coli tumbling, and the creation of a Serratia marcescens 'bacterial carpet' that mixes and pumps liquid inside microfluidic channels.



• Oxides Research Group - Shriram Ramanathan – (materials science)
  
  Research in our group is primarily focused on oxide thin films and nanostructures with emphasis on understanding how processing affects properties. Research activities include developing mechanistic understanding of initial stages of oxidation of metals and oxygen incorporation into oxides under photon irradiation. Phase evolution in oxides and their stability as a function of temperature and doping is investigated using combination of structural, electrical and electrochemical studies. Quantitative determination of oxygen concentration in nanoscale oxides and research on techniques to precisely control oxygen stoichiometry at interfaces are also being actively pursued. Potential applications of our research include electronic devices, solar and hydrogen energy conversion, sensors.

List of Past Research Groups