Browsing by Author "Canals, M."

Now showing 1 - 7 of 7
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    Adjustments of the oxygen diffusing capacity to energetic demands during the development of the quail (Coturnix coturnix japonica)
    (2011) Canals, M.; Martinez, B. B.; Figueroa, D.; Sabat, P.
    One of the hypotheses that attempt to explain physiological limitations of energy budgets is the symmorphosis hypothesis, which proposes that if matching structures to functional needs were combined with the strict economy of energy and materials, the result would be an optimal organ design for the specific function it serves. Evidence in favor of symmorphosis in adults is as abundant as evidence against it, but the plasticity of some morphological traits may be dependent on the ontogenetic stage at which acclimation acts. Thus, here we studied the adjustment of structure and function in lungs at different stages of development in the quail Coturnix coturnix japonica under two thermal regimes. Our main results show that i) resting metabolic rate, maximum thermogenic oxygen consumption and oxygen diffusion capacity did not exhibit developmental plasticity for two thermal environments: and ii) oxygen diffusion capacity fully adjusted to resting metabolic rate and maximum oxygen consumption during development. C coturnix has a low safety factor close to 1 which is consistent with the symmorphosis hypothesis. (C) 2011 Elsevier Inc. All rights reserved.
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    Effect of gestational and postnatal environmental temperature on metabolic rate in the altricial rodent, Phyllotis darwini
    (2009) Canals, M.; Figueroa, D. P.; Miranda, J. P.; Sabat, P.
    1. In the altricial rodent, Phyllotis darwini, we found higher body temperatures and faster developmental rates of the thermoregulatory, capacity in neonates born from cold- than warm-acclimated mothers.
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    Geometrical Aspects of the Energetic Effectiveness of Huddling in Small Mammals
    (1997) Canals, M.; Bozinovic Kuscevic, Francisco
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    Huddling Behavior as Critical Phase Transition Triggered by Low Temperatures
    (2011) Canals, M.; Bozinovic Kuscevic, Francisco
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    Modulating Factors of the Energetic Effectiveness of Huddling in Smal Mammals
    (1998) Canals, M.; Bozinovic Kuscevic, Francisco
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    Osmoregulation and adaptive radiation in the ovenbird genus Cinclodes (Passeriformes: Furnariidae)
    (2006) Sabat, P.; Maldonado, K.; Canals, M.; Martinez Del Rio, C.
    1. The genus Cinclodes is unique among passerines because it includes two species that can be considered marine/coastal and also includes several species that inhabit freshwater streams or that shift habitats between terrestrial/fresh water and marine habitats. The Cinclodes clade satisfies two criteria of an adaptive radiation: it is monophyletic and it experienced recent speciation accompanied by rapid phenotypic diversification.
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    Pulmonary hematological parameters, energetic flight demands and their correlation with oxygen diffusion capacity in the lungs
    (2007) Canals, M.; Donoso, C.; Figueroa, D.; Sabat, P.
    Hematological parameters of birds and mammals seem to respond to environmental requirements, such as hypoxia at high altitude and the energetic demands of locomotion and flight. In this work we hypothesize that lung capillary hematocrit and red blood size may be influenced by the energetic requirements of flight. Also, we propose that hematological parameters should vary together with the morphological parameters that determine oxygen diffusion capacity. We analyzed the red blood cell size and the local characteristics of the pulmonary capillary hematocrit correlating these with the pulmonary factors that determines the oxygen diffusion capacity. We deal with seven species, non-flying and flying birds and mammals, with different energetic requirements. The capillary hematocrit was not different in each taxon, but the red blood cell size was smaller in flying mammals and birds than non-flying ones. Correlation of erythrocyte size with the diffusing characteristics of the lungs produced a non-phylogenetic clustering with a group constituting by the bats Tadarida brasiliensis y Myotis chiloensis, and the bird Z. auriculata; revealing similar functional response in unrelated species. Finally, in mammals, a negative correlation between the red blood cell size and the mass-specific oxygen diffusion capacity was obtained. These results suggest that the direction of the hematological and pulmonary adjustments is governed mainly by the requirements of flight independent of phylogenetic origin of the species studied.