Spontaneous switching of frequency-locking by periodic stimulus in oscillators of plasmodium of the true slime mold

Biosystems ◽  
2004 ◽  
Vol 76 (1-3) ◽  
pp. 133-140 ◽  
Author(s):  
A. Takamatsu ◽  
T. Yamamoto ◽  
T. Fujii
Author(s):  
Ulrich Dierkes

Calcium is supposed to play an important role in the control of protoplasmic streaming in slime mold plasmodia. The motive force for protoplasmic streaming is generated by the interaction of actin and myosin. This contraction is supposed to be controlled by intracellular Ca-fluxes similar to the triggering system in skeleton muscle. The histochemical localisation of calcium however is problematic because of the possible diffusion artifacts especially in aquous media.To evaluate this problem calcium localisation was studied in small pieces of shock frozen (liquid propane at -189°C) plasmodial strands of Physarum polycephalum, which were further processed with 3 different methods: 1) freeze substitution in ethanol at -75°C, staining in 100% ethanol with 1% uranyl acetate, and embedding in styrene-methacrylate. For comparison the staining procedure was omitted in some preparations. 2)Freeze drying at about -95°C, followed by immersion with 100% ethanol containing 1% uranyl acetate, and embedding. 3) Freeze fracture, carbon coating and SEM investigation at temperatures below -100° C.


Author(s):  
K.I. Pagh ◽  
M.R. Adelman

Unicellular amoebae of the slime mold Physarum polycephalum undergo marked changes in cell shape and motility during their conversion into flagellate swimming cells (l). To understand the processes underlying motile activities expressed during the amoebo-flagellate transformation, we have undertaken detailed investigations of the organization, formation and functions of subcellular structures or domains of the cell which are hypothesized to play a role in movement. One focus of our studies is on a structure, termed the “ridge” which appears as a flattened extension of the periphery along the length of transforming cells (Fig. 1). Observations of live cells using Nomarski optics reveal two types of movement in this region:propagation of undulations along the length of the ridge and formation and retraction of filopodial projections from its edge. The differing activities appear to be associated with two characteristic morphologies, illustrated in Fig. 1.


1996 ◽  
Vol 32 (12) ◽  
pp. 1120 ◽  
Author(s):  
C.S. Park ◽  
G.Y. Lyu ◽  
D.H. Lee

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2551
Author(s):  
Kwang-Il Oh ◽  
Goo-Han Ko ◽  
Jeong-Geun Kim ◽  
Donghyun Baek

An 18.8–33.9 GHz, 2.26 mW current-reuse (CR) injection-locked frequency divider (ILFD) for radar sensor applications is presented in this paper. A fourth-order resonator is designed using a transformer with a distributed inductor for wideband operating of the ILFD. The CR core is employed to reduce the power consumption compared to conventional cross-coupled pair ILFDs. The targeted input center frequency is 24 GHz for radar application. The self-oscillated frequency of the proposed CR-ILFD is 14.08 GHz. The input frequency locking range is from 18.8 to 33.8 GHz (57%) at an injection power of 0 dBm without a capacitor bank or varactors. The proposed CR-ILFD consumes 2.26 mW of power from a 1 V supply voltage. The entire die size is 0.75 mm × 0.45 mm. This CR-ILFD is implemented in a 65 nm complementary metal-oxide semiconductor (CMOS) technology.


IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 226754-226772
Author(s):  
Trong-The Nguyen ◽  
Hong-Jiang Wang ◽  
Thi-Kien Dao ◽  
Jeng-Shyang Pan ◽  
Jian-Hua Liu ◽  
...  

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