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Perez-Gutierrez F.G.,Autonomous University of San Luis Potosi | Camacho-Lopez S.,Research Center Cientifica Educacin Superior Of Ensenada | Aguilar G.,University of California at Riverside | Aguilar G.,CINVESTAV
Journal of Biomedical Optics | Year: 2011

We present a time-resolved study of the interaction of nanosecond laser pulses with tissue phantoms. When a laser pulse interacts with a material, optical energy is absorbed by a combination of linear (heat generation and thermoelastic expansion) and nonlinear absorption (expanding plasma), according to both the laser light irradiance and material properties. The objective is to elucidate the contribution of linear and nonlinear optical absorption to bubble formation. Depending on the local temperatures and pressures reached, both interactions may lead to the formation of bubbles. We discuss three experimental approaches: piezoelectric sensors, time-resolved shadowgraphy, and time-resolved interferometry, to follow the formation of bubbles and measure the pressure originated by 6 ns laser pulses interacting with tissue phantoms. We studied the bubble formation and pressure transients for varying linear optical absorption and for radiant exposures above and below threshold for bubble formation. We report a rapid decay (of 2 orders of magnitude) of the laser-induced mechanical pressure measured (by time-resolved shadowgraphy) very close to the irradiation spot and beyond 1 mm from the irradiation site (by the piezoelectric sensor). Through time-resolved interferometry measurements, we determined that bubble formation can occur at marginal temperature increments as low as 3°C. © 2011 Society of Photo-Optical Instrumentation Engineers (SPIE). Source

Calderon-Aguilera L.E.,Research Center Cientifica Educacin Superior Of Ensenada | Reyes-Bonilla H.,Autonomous University of Baja California Sur | Paniagua-Chavez C.G.,Research Center Cientifica Educacin Superior Of Ensenada | Romo-Curiel A.E.,Research Center Cientifica Educacin Superior Of Ensenada | Moreno-Rivera V.M.,Research Center Cientifica Educacin Superior Of Ensenada
Journal of Shellfish Research | Year: 2010

This article describes the timing of gametogenic development and spawning in a population of geoduck clams, Panopea globosa (Dall 1898), from the Upper Gulf of California and its relationship to temperature changes and primary productivity. Clams were collected monthly over 1 year (March 2008 to March 2009), and salinity, dissolved oxygen, and substrate type were recorded during each survey. Standard histological analyses and measurements of oocyte diameters were used to describe the timing of gametogenic development and spawning. Satellite data for temperature and chlorophyll were gathered to test a general conceptual planktonic larval development model. The results demonstrated that reproductive activity was triggered by a steep decrease in temperature 4 months prior to the peak of productivity. Thus, larval development matches favorable conditions, as predicted by Cushing's MatchMismatch Hypothesis. Source

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