A5053424992- Laser-Matter Interactions and Applications
- Neurobiology and Insect Physiology Research
- Mass Spectrometry Techniques and Applications
- Spectroscopy and Quantum Chemical Studies
- Advanced Chemical Physics Studies
- Atomic and Molecular Physics
- Circadian rhythm and melatonin
- Insect and Arachnid Ecology and Behavior
- Advanced Memory and Neural Computing
- Plant and animal studies
- Plant and Biological Electrophysiology Studies
- Animal Behavior and Reproduction
- Quantum optics and atomic interactions
- Retinal Development and Disorders
- Photoreceptor and optogenetics research
- Neural dynamics and brain function
- Laser Design and Applications
- EEG and Brain-Computer Interfaces
- Visual perception and processing mechanisms
- Speech and Audio Processing
- CCD and CMOS Imaging Sensors
- Advanced Optical Imaging Technologies
- Advanced Fiber Laser Technologies
- Advanced Optical Sensing Technologies
- Gaze Tracking and Assistive Technology
Howard Hughes Medical Institute
2020-2025
Janelia Research Campus
2020-2025
University of Vermont
2024
Champalimaud Foundation
2024
Duke University
2020
George Washington University Virginia Campus
2020
Stony Brook University
2014-2018
Vision provides animals with detailed information about their surroundings, conveying diverse features such as color, form, and movement across the visual scene. Computing these parallel spatial requires a large network of neurons, that in distant flies humans, regions comprise half brain's volume. These brain often reveal remarkable structure-function relationships, neurons organized along maps shapes directly relate to roles processing. To unravel stunning diversity complex system, careful...
We demonstrate a coincidence velocity map imaging apparatus equipped with novel time-stamping fast optical camera, Tpx3Cam, whose high sensitivity and nanosecond timing resolution allow for simultaneous position time-of-flight detection. This single detector design is simple, flexible, capable of highly differential measurements. show detailed characterization the camera its application in strong field ionization experiments.
Abstract Introduction: Digital health is rapidly expanding due to surging healthcare costs, deteriorating outcomes, and the growing prevalence accessibility of mobile (mHealth) wearable technology. Data from Biometric Monitoring Technologies (BioMeTs), including mHealth wearables, can be transformed into digital biomarkers that act as indicators outcomes used diagnose monitor a number chronic diseases conditions. There are many challenges faced by biomarker development, lack regulatory...
Color and polarization provide complementary information about the world are detected by specialized photoreceptors. However, downstream neural circuits that process these distinct modalities incompletely understood in any animal. Using electron microscopy, we have systematically reconstructed synaptic targets of photoreceptors to detect color skylight Drosophila, used light microscopy confirm many our findings. We identified known novel selective for different wavelengths or polarized...
Abstract To survive, animals must convert sensory information into appropriate behaviours 1,2 . Vision is a common sense for locating ethologically relevant stimuli and guiding motor responses 3–5 How circuitry converts object location in retinal coordinates to movement direction body remains largely unknown. Here we show through behaviour, physiology, anatomy connectomics Drosophila that visuomotor transformation occurs by conversion of topographic maps formed the dendrites...
Visual systems can exploit spatial correlations in the visual scene by using retinotopy, organizing principle which neighboring cells encode locations. However, retinotopy is often lost, such as when pathways are integrated with other sensory modalities. How information processed outside of strictly brain areas? Here, we focused on looming responsive LC6 Drosophila, a population whose dendrites collectively cover field, but axons form single glomerulus-a structure without obvious retinotopic...
Summary Many animals rely on vision to navigate through their environment. The pattern of changes in the visual scene induced by self-motion is optic flow 1 , which first estimated local patches directionally selective (DS) neurons 2–4 . But how should arrays DS neurons, each responsive motion a preferred direction at specific retinal position, be organized support robust decoding downstream circuits? Understanding this global organization challenging because it requires mapping fine,...
Many animals, including humans, navigate their surroundings by visual input, yet we understand little about how information is transformed and integrated the navigation system. In
Flying insects exhibit remarkable navigational abilities controlled by their compact nervous systems. Optic flow , the pattern of changes in visual scene induced locomotion, is a crucial sensory cue for robust self-motion estimation, especially during rapid flight. Neurons that respond to specific, large-field optic patterns have been studied decades, primarily large flies, such as houseflies, blowflies, and hover flies. The best-known optic-flow sensitive neurons are tangential cells...
Abstract Vision provides animals with detailed information about their surroundings and conveys diverse features such as colour, form movement across the visual scene. Computing these parallel spatial requires a large network of neurons. Consequently, from flies to humans, regions in brain constitute half its volume. These often have marked structure–function relationships, neurons organized along maps shapes that directly relate roles processing. More than century anatomical studies...
Abstract Flying insects exhibit remarkable navigational abilities controlled by their compact nervous systems. Optic flow , the pattern of changes in visual scene induced locomotion, is a crucial sensory cue for robust self-motion estimation, especially during rapid flight. Neurons that respond to specific, large-field optic patterns have been studied decades, primarily large flies, such as houseflies, blowflies, and hover flies. The best-known optic-flow sensitive neurons are tangential...
We study strong-field molecular ionization as a function of pulse duration. Experimental measurements the photoelectron yield for number molecules reveal competition between different continua (cationic states) which depends strongly on Surprisingly, in limit short duration, we find that single ionic continuum dominates yield, whereas multiple are produced longer pulses. Using calculations take vibrational dynamics into account, interpret our results terms nuclear motion and nonadiabatic...
We present velocity map imaging measurements of photoelectrons in coincidence with ions produced via strong field molecular ionization. Our measurements, conjunction electronic structure and Stark shift calculations, allow us to assign several features the low energy portion photoelectron spectrum different continua (ionic states). Furthermore, we are able distinguish between direct indirect ionization pathways, uncovering role both neutral ionic resonances dynamics.
We study strong-field molecular ionization using few- (four to ten) cycle laser pulses. Employing a supercontinuum light source, we are able tune the optical wavelength (photon energy) over range of $\ensuremath{\sim}200$ nm (500 meV). measure photoelectron spectrum for series different molecules as function intensity, frequency, and bandwidth illustrate how dynamics vary with these parameters. find that multiphoton resonances nonadiabatic (internal conversion) play an important role result...
We demonstrate a single-detector velocity map imaging setup which is capable of rapidly switching between coincidence and non-coincidence measurements. By the extraction voltages on electrostatic lenses, both electrons ions can be collected in with single detector. Using fast camera as 2D detector avoids saturation problem associated traditional delay line detectors allows for easy transitions data collection modes. This major advantage setting up low-cost versatile apparatus. present...
We use velocity map imaging of photoelectrons in coincidence with molecular cations to determine which ionic states are populated via strong field ionization, and whether the ionization excited proceeds indirectly ground state or directly from neutral. carry out measurements on a series molecules that have different energy gaps between dissociative states. measure both direct indirect cations, find gap non-dissociative plays an important role determining amount ionization. Direct is...
Flying insects exhibit remarkable navigational abilities controlled by their compact nervous systems. Optic flow , the pattern of changes in visual scene induced locomotion, is a crucial sensory cue for robust self-motion estimation, especially during rapid flight. Neurons that respond to specific, large-field optic patterns have been studied decades, primarily large flies, such as houseflies, blowflies, and hover flies. The best-known optic-flow sensitive neurons are tangential cells...
Time-resolved measurements of strong-field molecular ionization are performed to measure the photoelectron spectrum as a function pump-probe delay. The allow one follow dynamics and break them down into three steps, which include electronic excitation, internal conversion, coupling continuum.
We study strong field double ionization of a series organic molecules by making use coincidence detection fragment ions. measure the yield as function pulse duration, intensity, polarization, and molecular conjugation. For conjugated we find enhancement in rate over what one would expect on basis tunneling or multiphoton rates. Calculations reveal correlation between electronic structure different observed yields, highlighting removal electrons from inner orbitals.
We study strong-field molecular ionization, with a focus on indirect ionization to dissociative excited ionic states. Indirect also known as post-ionization excitation, refers the excitation of cation following lower-lying state. propose two possible mechanisms underlying ionization: resonant transitions facilitated by nuclear dynamics and nonadiabatic driven laser field off resonance. compare them measuring dependence yield pulse duration for cations different electronic structures. Both...
We study strong-field dissociative molecular double ionization with momentum-resolved quadruple coincidence measurements, measuring the two electrons and ionic fragments produced a velocity map imaging apparatus. contrast measurements for different molecules. In one case, our reveal anticorrelation in momentum electrons. other, we find no anticorrelation, indicating differences underlying dynamics.
Microelectromechanical Systems (MEMS) Microphone arrays are becoming ubiquitous in consumer electronics. Large and expensive anechoic chambers commonly used to characterize these arrays. Individual MEMS microphones, on the other hand, typically tested using one of three methods: a free field calibration an chamber, pressure or plane wave tube (PWT). In this work, we present PWT system for testing single microphone as well second array four microphones. Both systems utilize 3D printed portion...
Abstract Color and polarization provide complementary information about the world are detected by specialized photoreceptors. However, downstream neural circuits that process these distinct modalities incompletely understood in any animal. Using electron microscopy, we have systematically reconstructed synaptic targets of photoreceptors to detect color skylight Drosophila , used light microscopy confirm many our findings. We identified known novel selective for different wavelengths or...