RESUMO
En este artículo pretendo mostrar que: 1. Para los fundadores de la genética de poblaciones, Fisher y Wright, existía una relación muy estrecha entre la física y la biología. 2. El deseo de matematizar la genética de poblaciones buscaba darle al evolucionismo el estatus de -ciencia dura-, al mismo nivel que la física de Boltzmann y Maxwell. 3. Este esfuerzo estuvo orientado a mostrar que la evolución por selección natural no se opone a las leyes termodinámicas que rigen la evolución de los sistemas físicos. 4. La metáfora que paradójicamente presenta a los seres vivos como -demonios de Maxwell- anticipó aspectos de las teorías evolutivas modernas que recurren a las ciencias de la información y la termodinámica de sistemas complejos adaptativos desarrolladas por Prigogine en 1970 y Kauffman en 1993. 5. Para finalizar presento un contraste entre Darwin y Einstein que permite esclarecer mejor los puentes y conexiones bidireccionales que se establecen entre la biología y la física.
This paper aims to illustrate: 1. that for the founders of population genetics, Fisher and Wright, there was a close relationship between physics and biology. 2. The mathematics of population genetics aimed at placing evolutionary theory as a -hard science- at the same level as Boltzmann and Maxwells physics. 3. This effort showed that the concept of evolution by natural selection does not contradict the laws of thermodynamics that rule the evolution of physical systems. 4. The metaphor that paradoxically represents living beings as -Maxwellian demons- anticipated some aspects of the present day evolutionary theories that recur to the thermodynamic of complex adaptive systems as developed by Prigogine, 1970, and Kauffman, 1993. 5. To conclude, I contrast Darwin and Einstein in order to clarify, how can be understood today, the bridges and bidirectional connections between physics and biology.
RESUMO
OBJECTIVES: An increase in volume and evidence of postvoiding residuals are both encountered in the bladder of diabetic patients and can lead to urinary tract infections and impair renal function. Our objective was to compare the bladder volume of diabetic children and adolescents with that of nondiabetic subjects. METHODS: We investigated 247 diabetic patients and 228 control subjects between the ages 3 and 21 years. The sonographic examination was performed with a full bladder, after spontaneous voiding, and after forced voiding. Three dimensions were determined: longitudinal, transverse, and anteroposterior transverse. The data were analyzed by the Chi2 test, analysis of variance, the Kruskal-Wallis test, and multivariate regression. RESULTS: The 2 groups were equivalent for age (P =.56) and sex (P =.82). The median full bladder volume was larger in the diabetic group (268 mL) than in the control group (220 mL; P =.0004). Postvoiding residual volume after spontaneous and forced voiding was significantly higher in the diabetic group (P <.0001). Multivariate analysis showed that being diabetic (P =.021), older than 9 years (P =.000), and female (P =.036) all influenced full bladder volume. CONCLUSIONS: Sonographic evaluation showed incipient bladder dysfunction in diabetic patients. The multivariate analysis showed that the increase in bladder volume had a association with age (>9 years), female sex, and mean glycosylated hemoglobin value. Thus, bladder volume evaluation by sonography should be incorporated in the routine assessment of patients with type 1 diabetes.
