sea lamprey locomotion

24

Upload: sheilsn

Post on 29-Jul-2015

949 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: Sea Lamprey Locomotion
Page 2: Sea Lamprey Locomotion

Parasitic Lives in the Atlantic Ocean,

Mediterranean Sea, and Great Lakes Up to 35.5 inches

Page 3: Sea Lamprey Locomotion

Pure entrainment: Phase differences all tend to a constant.

We add a forcer and look for all the oscillators to be entrained with the forcer.

Example of entrainment

Page 4: Sea Lamprey Locomotion

Spinal

Cord

Sinusoidal Forcing arm

Electrodes

Dr. Kathleen Hoffman Dr. Eric Tytell Dr. Avis Cohen Dr. Tim Kiemel

Page 5: Sea Lamprey Locomotion
Page 6: Sea Lamprey Locomotion

Entrainment

No Entrainment

Page 7: Sea Lamprey Locomotion

1 2 3

ωf

+ a sin(Θ2 – Θ1 +

Ψa)

+ d sin(Θ2 – Θ3 + Ψd) + f sin(Θf – Θ2 + Ψf)

Toy Model

+ d sin(Θ1 – Θ2 + Ψd) + a sin(Θ3 – Θ2 + Ψa)

ωf

Θ1’ =

Θ2’ =

Θ3’ =

ω

Θf’ =

ω

ω

Page 8: Sea Lamprey Locomotion

Nearest neighbor coupling, any oscillator can be forced

Page 9: Sea Lamprey Locomotion

With nearest neighbor coupling

1 2

ωf

+ a sin(Θ2 – Θ1) + d sin(Θ1 – Θ2 ) + f sin(Θf – Θ2)

ωf

Θ1’ =

Θ2’ =

ω

Θf’ =

ω

Page 10: Sea Lamprey Locomotion
Page 11: Sea Lamprey Locomotion
Page 12: Sea Lamprey Locomotion

We determine the Jacobian

And evaluate the determinant,

And the trace

Page 13: Sea Lamprey Locomotion

Fixed Points No Fixed Points

Page 14: Sea Lamprey Locomotion

With nearest neighbor coupling

1 2 3

ωf

Page 15: Sea Lamprey Locomotion

With nearest neighbor coupling

1 2 3

ωf

Page 16: Sea Lamprey Locomotion

Three oscillators with one end forced.

Three oscillators with forcing in the middle.

Page 17: Sea Lamprey Locomotion

2 3 4

ωf

1 5 n…

Page 18: Sea Lamprey Locomotion
Page 19: Sea Lamprey Locomotion

Five oscillators with the head forced

Five oscillators with forcing in the middle.

Page 20: Sea Lamprey Locomotion
Page 21: Sea Lamprey Locomotion

Calibrate our analysis with Eric’s data Look at different coupling systems

Page 22: Sea Lamprey Locomotion

Symmetry in the two oscillator system. Phase shifting Entrainment range limits

N-Oscillators with the head forced.

N-Oscillators with the tail forced.

Page 23: Sea Lamprey Locomotion

Dr. Joseph Previte Dr. Michael Rutter UMBC Team

› Dr. Kathleen Hoffman› Dr. Eric Tytell› Dr. Avis Cohen› Dr. Tim Kiemel

National Science Foundation

Page 24: Sea Lamprey Locomotion