post-doc talks 10/20/14

Ashesh Dhawale, Ölveczky Lab

  • “Role of subcortical circuits in motor skill learning”


  • Function of basal gangalion not well understood.
    • conflicting annotations
    • invovled in parkinsons, huntingtons
  • ‘sequencing chuncking’
    • organizes downstream circuits into groups (based on activity recording experiments).
    • monkey can still learn sequences without BG. speed of choice is a bit slower.


  • two tap with in-between delay.
  • initially the rat tends to tap too frequently, then eventualy strongly learns the tap interval. (takes 30 days to learn).
  • need to first teach to tap once. get a beep to know reward has arrived. Computer program trains rats.
  • dvelop whole series of additional movements
  • don’t require motor cortex to learn this. Do require BG.

Experiment 2

  • record from neurons. Film from 3 angles at high speed. Also have acceleratomoter.
  • see specific neuron firin at particular events
  • some cells fire in between task events very reliably.
  • controls sequencing.

Charles Vidoudez, Girguis Lab

  • “Deep Sea microorganisms, interactions with their environment, and the tools to study them “
  • interest: micro-organism community environment interactions
  • techniques: mass spec, metabolomics

intro: vents

  • hot fluid, anoxic, low pH, hihg CH4, H2S CO2, all mixing. Organisms use gradient in redox between ocean and vent.
  • muscles + symbiotic bacteria combine H2S and O2 and CH4 and O2 to produce energy.


  • current sampling: sample size is limited, time delay is a problem.
  • developed in situ mass spec — measure at site.
  • can observe consumption of H2S and CH4. More mussels where H2S is more, more use of whatever is more present.

Temporal resolution

  • now deployed long term sampling devices. sensors connected to internet via cables.

Ranga Dias, Lyman Lab – 1st physics talk!

  • “Insulator-metal transitions in simple molecular solids”
  • CS2 and super-conductivity.
  • 10 GPA (human on a 1mm needle.
  • oxygen metaziles at 60 GPA. becomes superconducting at 100 GPA
  • system – squeeze sample between two diamonds (800 to 100 um)
  • can generate pressures up to 350 GPa.
  • resistivity measurement. Try under pressure: need small probes.
  • Bridgeman (Nobel in ’46? for squeezing CS2 and solving the structure). CS3 at 20 GPA
  • compressed to 51.2 GPA become metal like – shiny / reflective.
  • resistivity drops 8 orders of magnitude when squeezed. Semiconductor in ‘black polymer’ regime. then metal.
  • superconductor becomes a perfect diamagnet Completely repels a magnetic field, moves out of the field. (hence magnetic levitation) response (travel without resistance, conduct without resistance).
  • Cool and have pressure (60 to 172 GPA) see superconductivity at 5-6 K. (high temp superconductor 150 K.
  • Faraday quote to chancellor of UK: use of electricity: some-day you can tax it.
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