Results 111 to 120 of about 154,855 (300)

Natural waters in Amazonia. III. Ammonium molybdate-reactive silica

, 1970
Natural waters of the Amazonian Tertiary formations along the Manaus-Itacoatjara Road were studied with respect to variations in average seasonal and yearly soluble silica content.
Brinkmann, W., Dos Santos, A.
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The effect of environmental factors on transepithelial potential in a model Amazonian teleost, the tambaqui (Colossoma macropomum): Implications for sodium balance in harsh environments

Journal of Fish Biology, EarlyView.
Abstract The tambaqui (Colossoma macropomum, G. Cuvier 1818) thrives both in the ion‐poor waters of the Amazon and in commercial aquaculture. In both, environmental conditions can be harsh due to low ion levels, occasional high salt challenges (in aquaculture), low pH, extreme PO2 levels (hypoxia and hyperoxia), high PCO2 levels (hypercapnia), high ...
Chris M. Wood, Anne Crémazy, Carolyn Morris, Ora E. Johannsson, Gudrun De Boeck, Adalberto Luis Val   +5 more
wiley   +1 more source

Oxygen consumption from air and water, ammonia and urea‐N excretion, and Na+ fluxes during progressive aquatic hypoxia in Amazonian armoured catfish Pterygoplichthys gibbiceps and Pterygoplichthys pardalis

Journal of Fish Biology, EarlyView.
Abstract The Amazonian loricariid fish Pterygoplichthys gibbiceps, from the Rio Negro, and Pterygoplichthys pardalis, from the Rio Solimões, are facultative air‐breathers that can use the stomach as an air‐breathing organ. Measurement of oxygen uptake under progressive aquatic hypoxia revealed a relatively high hypoxia resistance of both species.
Bernd Pelster, Chris M. Wood, Adalberto Luis Val   +2 more
wiley   +1 more source

Nitrogen excretion and oxygen consumption under severe hypoxia in siluriform fishes from the Amazon

Journal of Fish Biology, EarlyView.
Abstract Siluriform fishes collected from the Rio Negro and Rio Solimões proved to be highly resistant to aquatic hypoxia. In all four species analysed in this study, aquatic oxygen consumption significantly decreased from normoxic levels at water PO2 values near 1 kPa. Air‐breathing activity was observed only in Sturisoma sp. (Rio Negro).
Bernd Pelster, Chris M. Wood, Adalberto Luis Val   +2 more
wiley   +1 more source

SISTEMAS TUTORES INTELIGENTES COMO APOYO EN EL PROCESO DE APRENDIZAJE

Redes de Ingeniería, 2015
El objetivo principal de este artículo es la identificación de las principales características de los tutores inteligentes, su origen y evolución los cuales pueden ofrecer elementos para la formulación de nuevos proyectos de investigación relacionados ...
Edwin Eduardo Millan Rojas, Yilver Estiven Molina Hurtatiz, Yois Smith Pascuas Rengifo   +2 more
doaj  

Alternativas estratégicas para el desarrollo de negocios verdes productivos del Caquetá (Colombia)

Universidad y Empresa
Objetivo: el artículo tiene como propósito identificar alternativas para el desarrollo de negocios verdes en las asociaciones productivas del municipio de Florencia (Caquetá, Colombia).
Parcival Peña Torres, Claritza Marlés Betancourt, Camilo Esteban Capera García   +2 more
doaj   +1 more source

Branchial localization of acid (A‐type) and base (B‐type) excreting ionocytes in Amazonian stenohaline freshwater Potamotrygon ray

Journal of Fish Biology, EarlyView.
Abstract The branchial epithelium of Potamotrygon—a member of the only strictly freshwater elasmobranch family Potamotrygonidae—was observed via immunohistochemistry, and two distinct forms of ionocytes were identified. The acid (A‐type) and base (B‐type) secreting cells with respective basolateral–apical localizations of Na+/K+‐ATPase–Na+/H+ exchanger
M. W. Rossi, C. M. Wood, A. L. Val, J. M. Wilson   +3 more
wiley   +1 more source

Assessing the population structure of Plagioscion squamosissimus (Teleostei, Perciformes, Sciaenidae) from the São Francisco River, Bahia, Brazil, using body morphology and otolith shape signatures

Journal of Fish Biology, EarlyView.
Abstract The south American silver croaker, Plagioscion squamosissimus, holds significant importance for the artisanal fisheries in the sub‐middle and lower courses of the São Francisco River, located in northeastern Brazil. To investigate the population structure of this species along its longitudinal profile, a total of 150 individuals (50 fish per ...
F. L. Freitas, N. S. Pereira, P. B. Pinheiro, R. Schroeder, A. T. Correia   +4 more
wiley   +1 more source

Corporate Social Responsibility as a Determinant of Competitiveness in Supermarkets

Mercados y Negocios
The research aimed to analyze the contribution of Corporate Social Responsibility (CSR) to the competitiveness of supermarkets in Florencia, Caquetá in southern Colombia.
Yelly Yamparli Pardo Rozo, Gabriela Carvajal Valderrama, Alexandra Perdomo Carvajal   +2 more
doaj   +1 more source

A baseline appraisal of water-dependant ecosystem services, the roles they play within desakota livelihood systems and their potential sensitivity to climate change [PDF]

, 2008
This report forms part of a larger research programme on 'Reinterpreting the Urban-Rural Continuum', which conceptualises and investigates current knowledge and research gaps concerning 'the role that ecosystems services play in the livelihoods of the ...
Gosling, Simon, Gurnell, Angela, Jones, Alice, McGregor, Glenn, Moggeridge, Helen   +4 more
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