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ref: -0 tags: deeplabcut markerless tracking DCN transfer learning date: 10-03-2018 23:56 gmt revision:0 [head]

Markerless tracking of user-defined features with deep learning

  • Human - level tracking with as few as 200 labeled frames.
  • No dynamics - could be even better with a Kalman filter.
  • Uses a Google-trained DCN, 50 or 101 layers deep.
    • Network has a distinct read-out layer per feature to localize the probability of a body part to a pixel location.
  • Uses the DeeperCut network architecture / algorithm for pose estimation.
  • These deep features were trained on ImageNet
  • Trained on examples with both only the readout layers (rest fixed per ResNet), as well as end-to-end; latter performs better, unsurprising.

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ref: -0 tags: optical neural recording photon induced electron transfer date: 01-02-2013 04:25 gmt revision:2 [1] [0] [head]

PMID-22308458 Optically monitoring voltage in neurons by photo-induced electron transfer through molecular wires.

  • Photoinduced electron transfer.
    • About what you would think -- a photon bumps an electron into a higher orbital, and this electron can be donated to another group or drop back down & fluoresce a photon.
  • Good sensitivity: ΔF/F of 20-27% per 100mV, fast kinetics.
  • Not presently genetically targetable.
  • Makes sense in terms of energy: "A 100-mV depolarization changes the PeT driving force by 0.05 eV (one electron × half of 100-mV potential, or 0.05 V). Because PeT is a thermally controlled process, the value of 0.05 eV is large relative to the value of kT at 300 K (0.026 eV), yielding a large dynamic range between the rates of PeT at resting and depolarized potentials.
  • Why electrochromic dyes have plateaued:
    • "In contrast, electrochromic dyes have smaller delta G values, 0.003 (46) to 0.02 (47) eV, and larger comparison energies. Because the interaction is a photochemically controlled process, the energy of the exciting photon is the comparison energy, which is 1.5–2 eV for dyes in the blue-to-green region of the spectrum. Therefore, PeT and FRET dyes have large changes in energy versus their comparison energy (0.05 eV vs. 0.026 eV), giving high sensitivities; electrochromic dyes have small changes compared with the excitation photon (0.003–0.02 eV vs. 2 eV), producing low voltage sensitivity."

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ref: -0 tags: meng poon wireless power transfer date: 03-07-2012 22:23 gmt revision:0 [head]

IEEE-4353634 (pdf) Optimal Operating Frequency in Wireless Power Transmission for Implantable Devices