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	Provedor de dados Biol. Res. (6) RChHN (1) Autor GÜNTHER,BRUNO (7) MORGADO,ENRIQUE (7) JIMÉNEZ,RAÚL F (2) COCIÑA,MANUELA (1) JIMÉNEZ,CLAUDIA A (1) TORRES,PATRICIO (1) Mais... Palavra-chave Dimensional analysis (3) Allometric equations (2) Biological time (2) Body mass (2) Allometric scaling (1) Allometry (1) Arterial pressures (1) Biological similarities (1) Biological similarity (1) Body weight (1) Capillaries (1) Fetal life (1) Fourier transform (1) Hemorrhagic shock (1) Integral feedback (1) Physical time (1) Pulmonary microcirculation (1) Rest and exercise (1) Sheet flow (1) Space physiology (1) Mais... Tipo do documento Journal article (7) Ano 2005 (2) 2004 (2) 2003 (3) País Chile (7) Idioma Inglês (7)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 7 Primeira ... 1 ... Última Body mass and body weight: a dual reference system in biology RChHN GÜNTHER,BRUNO; MORGADO,ENRIQUE. ABSTRACT The aim of the present study was to compare two different biological similarity criteria, one was based on body mass (M) as a theoretical reference system in accordance with the MLT-system of physics, while the other utilized the body weight (W) for the same purpose. The mass-dependent allometry should be applied during space flights as well as during fetal and newborn conditions of life, whereas the weight-dependence should prevail in earth-bound physiology. The above mentioned distinctions are relevant not only for the specific metabolic rates but also for numerous biological time functions, as for instance for the heart and respiratory rates of all mammals, whose allometric exponent is b = - 0.09 during fetal life, and b = - 0.25 in all adult... Tipo: Journal article Palavras-chave: Dimensional analysis; Biological similarity; Allometry; Biological time; Fetal life; Space physiology. Ano: 2003 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2003000100006 Reply to Nespolo's paper entitled "New invariants and dimensionless numbers: Futile renaissance of old fallacies?" Biol. Res. GÜNTHER,BRUNO; MORGADO,ENRIQUE. Tipo: Journal article Ano: 2005 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602005000200002 Wavelet and Fourier analysis of ventricular and main arteries pulsations in anesthetized dogs Biol. Res. JIMÉNEZ,RAÚL F; TORRES,PATRICIO; GÜNTHER,BRUNO; MORGADO,ENRIQUE; JIMÉNEZ,CLAUDIA A. The purpose of this study was to characterize time-frequency behavior using the Continuous Wavelet Transform (CWT) and Fast Fourier Transform (FFT) to analyze ventricular and arterial pressure signals from anesthetized mongrel dogs. Both ventricular and arterial pressure pulsations were recorded using catheter-tip manometers and the CWT was applied to these signals to obtain module coefficients, associated contours, and the 3-D representation of these modules. FFT was applied to obtain the Fourier spectrum. The mathematical analysis of the cardiovascular pressure pulsations permitted the identification of the evolution of the frequency components for the aortic and pulmonary valve functions as well as the intra-ventricular and respiratory influences on the... Tipo: Journal article Palavras-chave: Wavelet transform; Fourier transform; Time-frequency-amplitude; Ventricular and arterial pressures. Ano: 2004 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602004000300008 Dimensional analysis revisited Biol. Res. GÜNTHER,BRUNO; MORGADO,ENRIQUE. The applicability of dimensional analysis (DA) is discussed in relation to the metabolic scaling laws. The evolution of different theories of biological similarity has shown that the calculated reduced exponents (b) of Huxley's allometric equation are closely correlated with the numerical values obtained from the statistical analysis of empirical data. Body mass and body weight are not equivalent as biological reference systems, since in accordance to Newton's second law, the former has a dimension of a mass, while the latter should be dimensionally considered as a force (W = MLT-2). This distinction affects the coefficients of the mass exponent (a). This difference is of paramount importance in microgravity conditions (spaceflight) and of buoyancy during... Tipo: Journal article Palavras-chave: Dimensional analysis; Allometric scaling; Theories of biological similarity; Body mass; Body weight. Ano: 2003 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602003000300011 Two alternative models concerning the perialveolar microcirculation in mammalian lungs Biol. Res. GÜNTHER,BRUNO; MORGADO,ENRIQUE; COCIÑA,MANUELA. Despite the fact that the concept of sheet-flow in the pulmonary microcirculation of mammals was introduced more than three decades ago, the capillary circulatory model still prevails in the physiological literature. Since cardiac output is identical in the systemic and in pulmonary circulations, it is noteworthy that in the former, the resulting arterial pressure is five times higher than that of the latter, which means that the corresponding microcirculations must be radically different. The present study addresses this problem from both morphological and physiological perspectives. Tipo: Journal article Palavras-chave: Arterial pressures; Capillaries; Pulmonary microcirculation; Sheet flow; Systemic circulation. Ano: 2005 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602005000100007 Time in physics and biology Biol. Res. GÜNTHER,BRUNO; MORGADO,ENRIQUE. In contrast with classical physics, particularly with Sir Isaac Newton, where time is a continuous function, generally valid, eternally and evenly flowing as an absolute time dimension, in the biological sciences, time is in essence of cyclical nature (physiological periodicities), where future passes to past through an infinitely thin boundary, the present. In addition, the duration of the present (DP) leads to the so-called 'granulation of time' in living beings, so that by the fusion of two successive pictures of the world, which are not entirely similar, they attain the perception of 'movement,' both in the real world as well as in the sham-movement in the mass media (TV). Tipo: Journal article Palavras-chave: Allometric equations; Biological time; Body mass; Physical time; Theory of biological similitude. Ano: 2004 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602004000500005 Homeostasis and Heterostasis: from Invariant to Dimensionless Numbers Biol. Res. GÜNTHER,BRUNO; MORGADO,ENRIQUE; JIMÉNEZ,RAÚL F. In the present paper we have examined the applicability of dimensionless and invariant numbers (DN & IN) to the analysis of the cardiovascular system of mammals, whose functions were measured at standard metabolic conditions. The calculated IN did not change when we compared these figures with those obtained in dogs while they were submitted to graded exercise on a treadmill. In both instances, rest and exercise, the constancy of the IN prevailed, in accordance with Cannon's principle of "homeostasis" (1929). On the contrary, when dogs were examined during a standardized hypovolemic shock, we observed a breakdown of the IN, and the resulting DN evolved as a reliable index of the condition of "heterostasis" as defined by H. Selye. The robustness of... Tipo: Journal article Palavras-chave: Dimensional analysis; Biological similarities; Allometric equations; Rest and exercise; Hemorrhagic shock; Integral feedback. Ano: 2003 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602003000200011 Registros recuperados: 7 Primeira ... 1 ... Última

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