251 research outputs found
Spatial and temporal dynamics of the mesozooplankton (Crustacea: Cladocera, Copepoda and Decapoda) in a Pampean shallow hyposaline lake during drought conditions
La laguna Sauce Grande, un lago poco profundo, eutrófico e hiposalino, se estudió mediante muestreos mensuales entre diciembre de 2009 a noviembre de 2010. La sequía que afectó a la región desde 2009 y durante todo el período de estudio interrumpió la entrada regular del río y la salida al Océano Atlántico. La laguna presentó un aumento de los valores de salinidad y condiciones altamente turbias como resultado de las condiciones de sequía y de la resuspensión de sedimento por efecto del viento. Los cladóceros pequeños como Moina micrura y el copépodo Boeckella poopoensis dominaron la comunidad del mesozooplancton. La salinidad determinó la composición del mesozooplancton; mientras tanto, la dinámica de la abundancia estuvo determinada por la temperatura junto con las condiciones eutróficas durante el período de estudio. En un contexto global de cambio climático, y en una región donde la sequía y los ciclos húmedos son frecuentes, estos resultados contribuyen a comprender aún más los procesos que afectan la estructura y dinámica de la comunidad de zooplancton durante eventos climáticos extremos.The Sauce Grande Lake, a shallow, eutrophic, and hyposaline lake, was studied through monthly samplings during a year (December 2009- November 2010). The drought that affected the region since 2009 and during the entire study period interrupted the regular inflow from the river and outflow to the Atlantic Ocean. The lake presented an increase of salinity values and highly turbid conditions as a result of the drought conditions and wind resuspension. Small cladocerans such as Moina micrura and the copepod Boeckella poopoensis dominated the mesozooplankton community. The salinity determined the mesozooplankton composition; meanwhile, the abundance dynamic was ruled by temperature in conjunction with the eutrophic conditions during the study period. In a global context of climate change, and in a region where drought and wet cycles are frequent, these results further contribute to understanding the processes affecting the zooplankton community structure and dynamics during extreme climate events.Instituto de Limnología "Dr. Raúl A. Ringuelet
Spatial and temporal dynamics of the mesozooplankton (Crustacea: Cladocera, Copepoda and Decapoda) in a Pampean shallow hyposaline lake during drought conditions
La laguna Sauce Grande, un lago poco profundo, eutrófico e hiposalino, se estudió mediante muestreos mensuales entre diciembre de 2009 a noviembre de 2010. La sequía que afectó a la región desde 2009 y durante todo el período de estudio interrumpió la entrada regular del río y la salida al Océano Atlántico. La laguna presentó un aumento de los valores de salinidad y condiciones altamente turbias como resultado de las condiciones de sequía y de la resuspensión de sedimento por efecto del viento. Los cladóceros pequeños como Moina micrura y el copépodo Boeckella poopoensis dominaron la comunidad del mesozooplancton. La salinidad determinó la composición del mesozooplancton; mientras tanto, la dinámica de la abundancia estuvo determinada por la temperatura junto con las condiciones eutróficas durante el período de estudio. En un contexto global de cambio climático, y en una región donde la sequía y los ciclos húmedos son frecuentes, estos resultados contribuyen a comprender aún más los procesos que afectan la estructura y dinámica de la comunidad de zooplancton durante eventos climáticos extremos.The Sauce Grande Lake, a shallow, eutrophic, and hyposaline lake, was studied through monthly samplings during a year (December 2009- November 2010). The drought that affected the region since 2009 and during the entire study period interrupted the regular inflow from the river and outflow to the Atlantic Ocean. The lake presented an increase of salinity values and highly turbid conditions as a result of the drought conditions and wind resuspension. Small cladocerans such as Moina micrura and the copepod Boeckella poopoensis dominated the mesozooplankton community. The salinity determined the mesozooplankton composition; meanwhile, the abundance dynamic was ruled by temperature in conjunction with the eutrophic conditions during the study period. In a global context of climate change, and in a region where drought and wet cycles are frequent, these results further contribute to understanding the processes affecting the zooplankton community structure and dynamics during extreme climate events.Instituto de Limnología "Dr. Raúl A. Ringuelet
Spatial and temporal dynamics of the mesozooplankton (Crustacea: Cladocera, Copepoda and Decapoda) in a Pampean shallow hyposaline lake during drought conditions
La laguna Sauce Grande, un lago poco profundo, eutrófico e hiposalino, se estudió mediante muestreos mensuales entre diciembre de 2009 a noviembre de 2010. La sequía que afectó a la región desde 2009 y durante todo el período de estudio interrumpió la entrada regular del río y la salida al Océano Atlántico. La laguna presentó un aumento de los valores de salinidad y condiciones altamente turbias como resultado de las condiciones de sequía y de la resuspensión de sedimento por efecto del viento. Los cladóceros pequeños como Moina micrura y el copépodo Boeckella poopoensis dominaron la comunidad del mesozooplancton. La salinidad determinó la composición del mesozooplancton; mientras tanto, la dinámica de la abundancia estuvo determinada por la temperatura junto con las condiciones eutróficas durante el período de estudio. En un contexto global de cambio climático, y en una región donde la sequía y los ciclos húmedos son frecuentes, estos resultados contribuyen a comprender aún más los procesos que afectan la estructura y dinámica de la comunidad de zooplancton durante eventos climáticos extremos.The Sauce Grande Lake, a shallow, eutrophic, and hyposaline lake, was studied through monthly samplings during a year (December 2009- November 2010). The drought that affected the region since 2009 and during the entire study period interrupted the regular inflow from the river and outflow to the Atlantic Ocean. The lake presented an increase of salinity values and highly turbid conditions as a result of the drought conditions and wind resuspension. Small cladocerans such as Moina micrura and the copepod Boeckella poopoensis dominated the mesozooplankton community. The salinity determined the mesozooplankton composition; meanwhile, the abundance dynamic was ruled by temperature in conjunction with the eutrophic conditions during the study period. In a global context of climate change, and in a region where drought and wet cycles are frequent, these results further contribute to understanding the processes affecting the zooplankton community structure and dynamics during extreme climate events.Instituto de Limnología "Dr. Raúl A. Ringuelet
High dielectric constant in Barium titanate-graphene composites around the percolation threshold
Resumen del trabajo presentado a la 14th International Conference of the European Ceramic Society, celebrada en Toledo (España) del 21 al 25 junio de 2015.Peer Reviewe
Grafito y grafeno
págs.: 109-137Capítulo incluido en el libro: Desarrollo y aplicaciones de materiales avanzados de carbón. Miguel Ángel Álvarez Merino, Francisco Carrasco Marín, Francisco José Maldonado Hódar (Editores). Sevilla: Univeridad Internacional de Andalucía, 2014. ISBN: 978-84-7993-247-3. Enlace: http://hdl.handle.net/10334
Characterisation of Goats’ Response to Heat Stress: Tools to Improve Heat Tolerance
This chapter aims to review present knowledge about the effects of heat stress on goats, summarising what is known about its measurement, its impact on the performances of the animals, mainly milk traits, the physiological and genetic bases of the animals’ response and the improvement of resilience through selection. A short historic review of the climatic indexes used to measure heat stress, with special emphasis on the temperature humidity indexes, and the main consequences on milk yield and composition are followed by a description of the results of experiments carried out to study the physiological and metabolic consequences of heat stress. The results of the quantitative analyses of the genetic bases of heat stress using norm of reaction models and of the application of omic techniques, particularly transcriptomic and genomic, to understand the complexity of the genetic background of animal’s reaction to thermal stress, constitute the next points. The chapter ends treating the possible ways and difficulties of applying selection to increase resilience to heat stress
Supercapacitor modified with methylene blue as redox active electrolyte
MWCNT-based supercapacitors (SC) containing methylene blue (MB) as redox active electrolyte were studied. MWCNTs were employed as model of electrode active material due to their ideal double-layer behavior facilitates the investigation of the energy storage mechanisms involved. MB led to a cell capacitance enhancement equal to 4.5 times the original cell capacitance of MWCNTs in sulphuric acid with a capacitance reduction of only 12% after 6000 charge–discharge cycles. The potential evolution of each electrode during galvanostatic cycling revealed that MB redox reaction develops in both electrodes simultaneously in the voltage range of 0–0.104 V and that this is the main cause of cell capacitance enhancement. Beyond this voltage range, the Faradaic contribution from the MB redox reaction decreases because the anode behaves as a capacitative electrode with a rather reduced charge-capacity due to the small surface area of MWCNTs. By means of a modified assembly composed of a Nafion membrane and MB and sulfuric acid solutions located in the cathode and anode compartments, respectively, it was demonstrated the limiting role of the capacitative electrode in the cell charge-capacity in this type of hybrid devices.The authors acknowledge the financial support of the MICINN (Project MAT2010-20601-C02-01). Silvia Roldán thanks MICINN for a FPI predoctoral research grant.Peer reviewe
Spatial and temporal dynamics of the mesozooplankton (Crustacea: Cladocera, Copepoda and Decapoda) in a Pampean shallow hyposaline lake during drought conditions
The Sauce Grande Lake, a shallow, eutrophic, and hyposaline lake, was studied through monthly samplings during a year (December 2009- November 2010). The drought that affected the region since 2009 and during the entire study period interrupted the regular inflow from the river and outflow to the Atlantic Ocean. The lake presented an increase of salinity values and highly turbid conditions as a result of the drought conditions and wind resuspension. Small cladocerans such as Moina micrura and the copepod Boeckella poopoensis dominated the mesozooplankton community. The salinity determined the mesozooplankton composition; meanwhile, the abundance dynamic was ruled by temperature in conjunction with the eutrophic conditions during the study period. In a global context of climate change, and in a region where drought and wet cycles are frequent, these results further contribute to understanding the processes affecting the zooplankton community structure and dynamics during extreme climate events.La laguna Sauce Grande, un lago poco profundo, eutrófico e hiposalino, se estudió mediante muestreos mensuales entre diciembre de 2009 a noviembre de 2010. La sequía que afectó a la región desde 2009 y durante todo el período de estudio interrumpió la entrada regular del río y la salida al Océano Atlántico. La laguna presentó un aumento de los valores de salinidad y condiciones altamente turbias como resultado de las condiciones de sequía y de la resuspensión de sedimento por efecto del viento. Los cladóceros pequeños como Moina micrura y el copépodo Boeckella poopoensis dominaron la comunidad del mesozooplancton. La salinidad determinó la composición del mesozooplancton; mientras tanto, la dinámica de la abundancia estuvo determinada por la temperatura junto con las condiciones eutróficas durante el período de estudio. En un contexto global de cambio climático, y en una región donde la sequía y los ciclos húmedos son frecuentes, estos resultados contribuyen a comprender aún más los procesos que afectan la estructura y dinámica de la comunidad de zooplancton durante eventos climáticos extremos
Wind Pattern Change Along a Period of Coastal Occurrence Variation of a Stinging Medusa on a SW Atlantic Beach
Monte Hermoso (SW Atlantic, Argentina) is a coastal ecosystem highly modulated by wind forcing. Offshore winds have
historically played a leading role in the tourist influx as they are associated with the occurrence of the endemic stinging medusa Olindias
sambaquiensis. This species is closely related to warm summers but it could be favored by low temperatures in previous winters.
Since summer 2013, a change in the wind pattern was locally perceived coincidently with the absence of the medusa in coastal waters.
This work aimed at analyzing if wind pattern and sea surface temperature (SST) showed a measurable change along 2008-2015 and
evaluating if this change can be associated to the observed variations in the occurrence pattern of O. sambaquiensis. Winds and SST
data were analyzed in periods of high (2008-2012) and low (2013-2015) medusae occurrence, based on media and own observations.
A significant change in the wind pattern in Monte Hermoso was detected. Wind speed decreased from 6.3 m s-1 in 2008 to 2.4 m s-1 in
2015 and calms and light winds increased by more than 44.2 and 7.5 %, respectively. This change implied an impediment of coastal
upwelling, which is the physical process by which medusae reach the coast, and is associated with persistent (10 h or more) WNW
to ENE winds blowing at ≥ 3.3 m s-1. Accordingly, in summer 2008 (period of high medusae occurrence), 45 coastal upwelling-days
were detected in contrast to only 8 days in summer 2015 (period of absence of medusae). Also, positive SST anomalies were found
over the 8-yr period, suggesting an increasing trend of 0.4 °C. Higher temperatures than normal during recent winters probably affect
negatively the polyp reproduction. Our results demonstrate an environmental change in the ecosystem of Monte Hermoso and may
explain, in part, the low occurrence of O. sambaquiensis in recent summers. The knowledge of the factors that regulate the occurrence
of O. sambaquiensis is fundamental for developing a coastal management plan and/or for determining the first adaptation strategies
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