Method for successive photographing of rapid crack bifurcation by means of high-speed holographic microscopy

2001 ◽  
Author(s):  
Shinichi Suzuki ◽  
Kenichi Sakaue ◽  
Yasuyuki Morita ◽  
Taichi Mori
Keyword(s):  
High Speed ◽  
Holographic Microscopy ◽  
Crack Bifurcation

scholarly journals A dinoflagellate exploits toxins to immobilize prey prior to ingestion

2010 ◽  
Vol 107 (5) ◽  
pp. 2082-2087 ◽  
Author(s):  
Jian Sheng ◽  
Edwin Malkiel ◽  
Joseph Katz ◽  
Jason E. Adolf ◽  
Allen R. Place
Keyword(s):  
High Speed ◽  
Algal Bloom ◽  
Harmful Algal Bloom ◽  
Fish Kills ◽  
Karlodinium Veneficum ◽  
Prey Behavior ◽  
Dense Suspensions ◽  
Holographic Microscopy ◽  
Critical Understanding ◽  
Grazing Pressures

Toxins produced by the harmful algal bloom (HAB) forming, mixotrophic dinoflagellate Karlodinium veneficum have long been associated with fish kills. To date, the perceived ecological role for toxins has been relief from grazing pressures. Here, we demonstrate that karlotoxins also serve as a predation instrument. Using high-speed holographic microscopy, we measure the swimming behavior of several toxic and nontoxic strains of K. veneficum and their prey, Storeatula major, within dense suspensions. The selected strains produce toxins with varying potency and dosages, including a nontoxic one. Results clearly show that mixing the prey with the predatory, toxic strains causes prey immobilization at rates that are consistent with the karlotoxins’ potency and dosage. Even prey cells that continue swimming slow down after exposure to toxic predators. The swimming characteristics of predators vary substantially in pure suspensions, as quantified by their velocity, radii of helical trajectories, and direction of helical rotation. When mixed with prey, all toxic strains that are involved in predation slow down. Furthermore, they substantially reduced their predominantly vertical migration, presumably to remain in the vicinity of their prey. Conversely, the nontoxic control strain does not alter its swimming and does not affect prey behavior. In separate experiments, we show that exposing prey to exogenous toxins also causes prey immobilization at rates consistent with potency. Clearly, the toxic predatory strains use karlotoxins as a means of stunning their prey, before ingesting it. These findings add a substantiated critical understanding for why some HAB species produce such complex toxin molecules.

scholarly journals Three-axis digital holographic microscopy for high speed volumetric imaging

2014 ◽  
Vol 22 (11) ◽  
pp. 13710 ◽  
Author(s):  
F. Saglimbeni ◽  
S. Bianchi ◽  
A. Lepore ◽  
R. Di Leonardo
Keyword(s):  
High Speed ◽  
Digital Holographic Microscopy ◽  
Volumetric Imaging ◽  
Holographic Microscopy
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