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Papers by Cesar O. Pacherres

Research paper thumbnail of Simultaneous visualization of flow fields and oxygen concentrations to unravel transport and metabolic processes in biological systems

Research paper thumbnail of Simultaneous visualization of flow fields and oxygen concentrations to unravel transport and metabolic processes in biological systems

Research paper thumbnail of The role of ciliary vortices on the coral's oxygen exchange and food capture

Tropical shallow corals live in a highly dynamic environment dominated by wave action with water ... more Tropical shallow corals live in a highly dynamic environment dominated by wave action with water currents ruling over their physiological processes. Due to their relatively small size and lack of mobility, they will interact with the water column via a so called diffusive boundary layer (DBL), a layer of water located at the immediate surface of the coral and where molecular diffusion is the dominant transport mechanism for solutes. All elements needed to ensure the functioning of the coral, and its symbiotic algae, must traverse this layer in order to either reach or leave the coral tissue. Thus, the recent discovery that corals possess the ability to enhance mass transport in the DBL by the generation of vortices caused by the beating of epidermal cilia, opened several questions as of the extent of their effect on the coral's ecophysiological processes. The aim of this thesis is to better understand the role which ciliary vortices play on the dynamics of the coral boundary lay...

Research paper thumbnail of The role of ciliary vortices on the coral's oxygen exchange and food capture

Tropical shallow corals live in a highly dynamic environment dominated by wave action with water ... more Tropical shallow corals live in a highly dynamic environment dominated by wave action with water currents ruling over their physiological processes. Due to their relatively small size and lack of mobility, they will interact with the water column via a so called diffusive boundary layer (DBL), a layer of water located at the immediate surface of the coral and where molecular diffusion is the dominant transport mechanism for solutes. All elements needed to ensure the functioning of the coral, and its symbiotic algae, must traverse this layer in order to either reach or leave the coral tissue. Thus, the recent discovery that corals possess the ability to enhance mass transport in the DBL by the generation of vortices caused by the beating of epidermal cilia, opened several questions as of the extent of their effect on the coral's ecophysiological processes. The aim of this thesis is to better understand the role which ciliary vortices play on the dynamics of the coral boundary lay...

Research paper thumbnail of SensPIV: Simultaneous Visualization of Flow Fields and Oxygen Concentrations to Unravel Metabolic Exchange Fluxes

SSRN Electronic Journal, 2022

Research paper thumbnail of SensPIV: Simultaneous Visualization of Flow Fields and Oxygen Concentrations to Unravel Metabolic Exchange Fluxes

SSRN Electronic Journal, 2022

Research paper thumbnail of Experiemntal Studies on the Operating Characteristics of an Ammonia-Water Absorption System for Solar Cooling

Chemical Engineering Research & Design, 1990

An experimental ammonia-water absorption refrigerator has been designed to operate at very low ge... more An experimental ammonia-water absorption refrigerator has been designed to operate at very low generator temperatures in order to make use of low temperature energy sources such as unconcentrated solar energy. A novel type of generator using the falling film principle was used and proved to be an efficient way to extract heat from a low temperature energy source

Research paper thumbnail of Microplastic pollution in the Southern Ocean

Research paper thumbnail of Microplastic pollution in the Southern Ocean

Research paper thumbnail of Functional analysis of the spatiotemporal distribution of the macrobenthos associated to bathylithological aspects and environmental variables at the Mackellar Inlet, King George Island, Antarctica

Trabajo presentado en el IX Congreso Latinoamericano de Ciencia Antartica. 4 al 6 de octubre de 2... more Trabajo presentado en el IX Congreso Latinoamericano de Ciencia Antartica. 4 al 6 de octubre de 2017, Punta Arenas-Chile. IX Latin American Congress on Antarctic Science.

Research paper thumbnail of Functional analysis of the spatiotemporal distribution of the macrobenthos associated to bathylithological aspects and environmental variables at the Mackellar Inlet, King George Island, Antarctica

Trabajo presentado en el IX Congreso Latinoamericano de Ciencia Antartica. 4 al 6 de octubre de 2... more Trabajo presentado en el IX Congreso Latinoamericano de Ciencia Antartica. 4 al 6 de octubre de 2017, Punta Arenas-Chile. IX Latin American Congress on Antarctic Science.

Research paper thumbnail of Crecimiento y propagación de Limnobium laevigatum (Hydrocharitaceae) bajo diferentes concentraciones de nutrientes

Limnobium laevigatum es una macrofita flotante ampliamente distribuida en los paises del neotropi... more Limnobium laevigatum es una macrofita flotante ampliamente distribuida en los paises del neotropico. Debido a su potencial como biorremediador es importante conocer las mejores condiciones que permitan su propagacion. Uno de los factores mas importantes es la concentracion de nutrientes en el medio. Por ello, el presente trabajo tiene como objetivo conocer la concentracion de nutrientes a la cual se logra una propagacion optima de L. laevigatum bajo condiciones de laboratorio cuantificando parametros de crecimiento como la biomasa, area ocupada, tamano de las raices y produccion de hojas. Para ello se monitorearon en laboratorio durante 21 dias estos parametros morfologicos en plantas sometidas a cinco concentraciones de nutrientes (0x, 12,5X, 25X, 50X y 100X proporcional a la concentracion de nutrientes). La mayor produccion de hojas, peso fresco, numero de rametos y area foliar se alcanzo con los tratamientos de concentraciones intermedias en nutrientes (12,5X y 25X). Los tratamie...

Research paper thumbnail of Crecimiento y propagación de Limnobium laevigatum (Hydrocharitaceae) bajo diferentes concentraciones de nutrientes

Limnobium laevigatum es una macrofita flotante ampliamente distribuida en los paises del neotropi... more Limnobium laevigatum es una macrofita flotante ampliamente distribuida en los paises del neotropico. Debido a su potencial como biorremediador es importante conocer las mejores condiciones que permitan su propagacion. Uno de los factores mas importantes es la concentracion de nutrientes en el medio. Por ello, el presente trabajo tiene como objetivo conocer la concentracion de nutrientes a la cual se logra una propagacion optima de L. laevigatum bajo condiciones de laboratorio cuantificando parametros de crecimiento como la biomasa, area ocupada, tamano de las raices y produccion de hojas. Para ello se monitorearon en laboratorio durante 21 dias estos parametros morfologicos en plantas sometidas a cinco concentraciones de nutrientes (0x, 12,5X, 25X, 50X y 100X proporcional a la concentracion de nutrientes). La mayor produccion de hojas, peso fresco, numero de rametos y area foliar se alcanzo con los tratamientos de concentraciones intermedias en nutrientes (12,5X y 25X). Los tratamie...

Research paper thumbnail of Simultaneous visualization of flow fields and oxygen concentrations to unravel transport and metabolic processes in biological systems

Research paper thumbnail of The role of ciliary vortices on the coral's oxygen exchange and food capture

Tropical shallow corals live in a highly dynamic environment dominated by wave action with water ... more Tropical shallow corals live in a highly dynamic environment dominated by wave action with water currents ruling over their physiological processes. Due to their relatively small size and lack of mobility, they will interact with the water column via a so called diffusive boundary layer (DBL), a layer of water located at the immediate surface of the coral and where molecular diffusion is the dominant transport mechanism for solutes. All elements needed to ensure the functioning of the coral, and its symbiotic algae, must traverse this layer in order to either reach or leave the coral tissue. Thus, the recent discovery that corals possess the ability to enhance mass transport in the DBL by the generation of vortices caused by the beating of epidermal cilia, opened several questions as of the extent of their effect on the coral's ecophysiological processes. The aim of this thesis is to better understand the role which ciliary vortices play on the dynamics of the coral boundary lay...

Research paper thumbnail of SensPIV: Simultaneous Visualization of Flow Fields and Oxygen Concentrations to Unravel Metabolic Exchange Fluxes

SSRN Electronic Journal, 2022

Research paper thumbnail of Microplastic pollution in the Southern Ocean

Research paper thumbnail of Functional analysis of the spatiotemporal distribution of the macrobenthos associated to bathylithological aspects and environmental variables at the Mackellar Inlet, King George Island, Antarctica

Trabajo presentado en el IX Congreso Latinoamericano de Ciencia Antartica. 4 al 6 de octubre de 2... more Trabajo presentado en el IX Congreso Latinoamericano de Ciencia Antartica. 4 al 6 de octubre de 2017, Punta Arenas-Chile. IX Latin American Congress on Antarctic Science.

Research paper thumbnail of Crecimiento y propagación de Limnobium laevigatum (Hydrocharitaceae) bajo diferentes concentraciones de nutrientes

Limnobium laevigatum es una macrofita flotante ampliamente distribuida en los paises del neotropi... more Limnobium laevigatum es una macrofita flotante ampliamente distribuida en los paises del neotropico. Debido a su potencial como biorremediador es importante conocer las mejores condiciones que permitan su propagacion. Uno de los factores mas importantes es la concentracion de nutrientes en el medio. Por ello, el presente trabajo tiene como objetivo conocer la concentracion de nutrientes a la cual se logra una propagacion optima de L. laevigatum bajo condiciones de laboratorio cuantificando parametros de crecimiento como la biomasa, area ocupada, tamano de las raices y produccion de hojas. Para ello se monitorearon en laboratorio durante 21 dias estos parametros morfologicos en plantas sometidas a cinco concentraciones de nutrientes (0x, 12,5X, 25X, 50X y 100X proporcional a la concentracion de nutrientes). La mayor produccion de hojas, peso fresco, numero de rametos y area foliar se alcanzo con los tratamientos de concentraciones intermedias en nutrientes (12,5X y 25X). Los tratamie...

Research paper thumbnail of Ciliary vortex flows and oxygen dynamics in the coral boundary layer

Scientific Reports, 2020

The exchange of metabolites between environment and coral tissue depends on the flux across the d... more The exchange of metabolites between environment and coral tissue depends on the flux across the diffusive boundary layer (DBL) surrounding the tissue. Cilia covering the coral tissue have been shown to create vortices that enhance mixing in the DBL in stagnant water. To study the role of cilia under simulated ambient currents, we designed a new light-sheet microscopy based flow chamber setup. Microparticle velocimetry was combined with high-resolution oxygen profiling in the coral Porites lutea under varying current and light conditions with natural and arrested cilia beating. Cilia-generated vortices in the lower DBL mitigated extreme oxygen concentrations close to the tissue surface. Under light and arrested cilia, oxygen surplus at the tissue surface increased to 350 µM above ambient, in contrast to 25 µM under ciliary beating. Oxygen shortage in darkness decreased from 120 µM (cilia arrested) to 86 µM (cilia active) below ambient. Ciliary redistribution of oxygen had no effect o...

Research paper thumbnail of Simultaneous visualization of flow fields and oxygen concentrations to unravel transport and metabolic processes in biological systems

Research paper thumbnail of Simultaneous visualization of flow fields and oxygen concentrations to unravel transport and metabolic processes in biological systems

Research paper thumbnail of The role of ciliary vortices on the coral's oxygen exchange and food capture

Tropical shallow corals live in a highly dynamic environment dominated by wave action with water ... more Tropical shallow corals live in a highly dynamic environment dominated by wave action with water currents ruling over their physiological processes. Due to their relatively small size and lack of mobility, they will interact with the water column via a so called diffusive boundary layer (DBL), a layer of water located at the immediate surface of the coral and where molecular diffusion is the dominant transport mechanism for solutes. All elements needed to ensure the functioning of the coral, and its symbiotic algae, must traverse this layer in order to either reach or leave the coral tissue. Thus, the recent discovery that corals possess the ability to enhance mass transport in the DBL by the generation of vortices caused by the beating of epidermal cilia, opened several questions as of the extent of their effect on the coral's ecophysiological processes. The aim of this thesis is to better understand the role which ciliary vortices play on the dynamics of the coral boundary lay...

Research paper thumbnail of The role of ciliary vortices on the coral's oxygen exchange and food capture

Tropical shallow corals live in a highly dynamic environment dominated by wave action with water ... more Tropical shallow corals live in a highly dynamic environment dominated by wave action with water currents ruling over their physiological processes. Due to their relatively small size and lack of mobility, they will interact with the water column via a so called diffusive boundary layer (DBL), a layer of water located at the immediate surface of the coral and where molecular diffusion is the dominant transport mechanism for solutes. All elements needed to ensure the functioning of the coral, and its symbiotic algae, must traverse this layer in order to either reach or leave the coral tissue. Thus, the recent discovery that corals possess the ability to enhance mass transport in the DBL by the generation of vortices caused by the beating of epidermal cilia, opened several questions as of the extent of their effect on the coral's ecophysiological processes. The aim of this thesis is to better understand the role which ciliary vortices play on the dynamics of the coral boundary lay...

Research paper thumbnail of SensPIV: Simultaneous Visualization of Flow Fields and Oxygen Concentrations to Unravel Metabolic Exchange Fluxes

SSRN Electronic Journal, 2022

Research paper thumbnail of SensPIV: Simultaneous Visualization of Flow Fields and Oxygen Concentrations to Unravel Metabolic Exchange Fluxes

SSRN Electronic Journal, 2022

Research paper thumbnail of Experiemntal Studies on the Operating Characteristics of an Ammonia-Water Absorption System for Solar Cooling

Chemical Engineering Research & Design, 1990

An experimental ammonia-water absorption refrigerator has been designed to operate at very low ge... more An experimental ammonia-water absorption refrigerator has been designed to operate at very low generator temperatures in order to make use of low temperature energy sources such as unconcentrated solar energy. A novel type of generator using the falling film principle was used and proved to be an efficient way to extract heat from a low temperature energy source

Research paper thumbnail of Microplastic pollution in the Southern Ocean

Research paper thumbnail of Microplastic pollution in the Southern Ocean

Research paper thumbnail of Functional analysis of the spatiotemporal distribution of the macrobenthos associated to bathylithological aspects and environmental variables at the Mackellar Inlet, King George Island, Antarctica

Trabajo presentado en el IX Congreso Latinoamericano de Ciencia Antartica. 4 al 6 de octubre de 2... more Trabajo presentado en el IX Congreso Latinoamericano de Ciencia Antartica. 4 al 6 de octubre de 2017, Punta Arenas-Chile. IX Latin American Congress on Antarctic Science.

Research paper thumbnail of Functional analysis of the spatiotemporal distribution of the macrobenthos associated to bathylithological aspects and environmental variables at the Mackellar Inlet, King George Island, Antarctica

Trabajo presentado en el IX Congreso Latinoamericano de Ciencia Antartica. 4 al 6 de octubre de 2... more Trabajo presentado en el IX Congreso Latinoamericano de Ciencia Antartica. 4 al 6 de octubre de 2017, Punta Arenas-Chile. IX Latin American Congress on Antarctic Science.

Research paper thumbnail of Crecimiento y propagación de Limnobium laevigatum (Hydrocharitaceae) bajo diferentes concentraciones de nutrientes

Limnobium laevigatum es una macrofita flotante ampliamente distribuida en los paises del neotropi... more Limnobium laevigatum es una macrofita flotante ampliamente distribuida en los paises del neotropico. Debido a su potencial como biorremediador es importante conocer las mejores condiciones que permitan su propagacion. Uno de los factores mas importantes es la concentracion de nutrientes en el medio. Por ello, el presente trabajo tiene como objetivo conocer la concentracion de nutrientes a la cual se logra una propagacion optima de L. laevigatum bajo condiciones de laboratorio cuantificando parametros de crecimiento como la biomasa, area ocupada, tamano de las raices y produccion de hojas. Para ello se monitorearon en laboratorio durante 21 dias estos parametros morfologicos en plantas sometidas a cinco concentraciones de nutrientes (0x, 12,5X, 25X, 50X y 100X proporcional a la concentracion de nutrientes). La mayor produccion de hojas, peso fresco, numero de rametos y area foliar se alcanzo con los tratamientos de concentraciones intermedias en nutrientes (12,5X y 25X). Los tratamie...

Research paper thumbnail of Crecimiento y propagación de Limnobium laevigatum (Hydrocharitaceae) bajo diferentes concentraciones de nutrientes

Limnobium laevigatum es una macrofita flotante ampliamente distribuida en los paises del neotropi... more Limnobium laevigatum es una macrofita flotante ampliamente distribuida en los paises del neotropico. Debido a su potencial como biorremediador es importante conocer las mejores condiciones que permitan su propagacion. Uno de los factores mas importantes es la concentracion de nutrientes en el medio. Por ello, el presente trabajo tiene como objetivo conocer la concentracion de nutrientes a la cual se logra una propagacion optima de L. laevigatum bajo condiciones de laboratorio cuantificando parametros de crecimiento como la biomasa, area ocupada, tamano de las raices y produccion de hojas. Para ello se monitorearon en laboratorio durante 21 dias estos parametros morfologicos en plantas sometidas a cinco concentraciones de nutrientes (0x, 12,5X, 25X, 50X y 100X proporcional a la concentracion de nutrientes). La mayor produccion de hojas, peso fresco, numero de rametos y area foliar se alcanzo con los tratamientos de concentraciones intermedias en nutrientes (12,5X y 25X). Los tratamie...

Research paper thumbnail of Simultaneous visualization of flow fields and oxygen concentrations to unravel transport and metabolic processes in biological systems

Research paper thumbnail of The role of ciliary vortices on the coral's oxygen exchange and food capture

Tropical shallow corals live in a highly dynamic environment dominated by wave action with water ... more Tropical shallow corals live in a highly dynamic environment dominated by wave action with water currents ruling over their physiological processes. Due to their relatively small size and lack of mobility, they will interact with the water column via a so called diffusive boundary layer (DBL), a layer of water located at the immediate surface of the coral and where molecular diffusion is the dominant transport mechanism for solutes. All elements needed to ensure the functioning of the coral, and its symbiotic algae, must traverse this layer in order to either reach or leave the coral tissue. Thus, the recent discovery that corals possess the ability to enhance mass transport in the DBL by the generation of vortices caused by the beating of epidermal cilia, opened several questions as of the extent of their effect on the coral's ecophysiological processes. The aim of this thesis is to better understand the role which ciliary vortices play on the dynamics of the coral boundary lay...

Research paper thumbnail of SensPIV: Simultaneous Visualization of Flow Fields and Oxygen Concentrations to Unravel Metabolic Exchange Fluxes

SSRN Electronic Journal, 2022

Research paper thumbnail of Microplastic pollution in the Southern Ocean

Research paper thumbnail of Functional analysis of the spatiotemporal distribution of the macrobenthos associated to bathylithological aspects and environmental variables at the Mackellar Inlet, King George Island, Antarctica

Trabajo presentado en el IX Congreso Latinoamericano de Ciencia Antartica. 4 al 6 de octubre de 2... more Trabajo presentado en el IX Congreso Latinoamericano de Ciencia Antartica. 4 al 6 de octubre de 2017, Punta Arenas-Chile. IX Latin American Congress on Antarctic Science.

Research paper thumbnail of Crecimiento y propagación de Limnobium laevigatum (Hydrocharitaceae) bajo diferentes concentraciones de nutrientes

Limnobium laevigatum es una macrofita flotante ampliamente distribuida en los paises del neotropi... more Limnobium laevigatum es una macrofita flotante ampliamente distribuida en los paises del neotropico. Debido a su potencial como biorremediador es importante conocer las mejores condiciones que permitan su propagacion. Uno de los factores mas importantes es la concentracion de nutrientes en el medio. Por ello, el presente trabajo tiene como objetivo conocer la concentracion de nutrientes a la cual se logra una propagacion optima de L. laevigatum bajo condiciones de laboratorio cuantificando parametros de crecimiento como la biomasa, area ocupada, tamano de las raices y produccion de hojas. Para ello se monitorearon en laboratorio durante 21 dias estos parametros morfologicos en plantas sometidas a cinco concentraciones de nutrientes (0x, 12,5X, 25X, 50X y 100X proporcional a la concentracion de nutrientes). La mayor produccion de hojas, peso fresco, numero de rametos y area foliar se alcanzo con los tratamientos de concentraciones intermedias en nutrientes (12,5X y 25X). Los tratamie...

Research paper thumbnail of Ciliary vortex flows and oxygen dynamics in the coral boundary layer

Scientific Reports, 2020

The exchange of metabolites between environment and coral tissue depends on the flux across the d... more The exchange of metabolites between environment and coral tissue depends on the flux across the diffusive boundary layer (DBL) surrounding the tissue. Cilia covering the coral tissue have been shown to create vortices that enhance mixing in the DBL in stagnant water. To study the role of cilia under simulated ambient currents, we designed a new light-sheet microscopy based flow chamber setup. Microparticle velocimetry was combined with high-resolution oxygen profiling in the coral Porites lutea under varying current and light conditions with natural and arrested cilia beating. Cilia-generated vortices in the lower DBL mitigated extreme oxygen concentrations close to the tissue surface. Under light and arrested cilia, oxygen surplus at the tissue surface increased to 350 µM above ambient, in contrast to 25 µM under ciliary beating. Oxygen shortage in darkness decreased from 120 µM (cilia arrested) to 86 µM (cilia active) below ambient. Ciliary redistribution of oxygen had no effect o...