Search results for "Causal analysis"
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Evidence of unbalanced regulatory mechanism of heart rate and systolic pressure after acute myocardial infarction
2002
The interactions between systolic arterial pressure (SAP) and R-R interval (RR) fluctuations after acute myocardial infarction (AMI) were investigated by measures of synchronization separating the feedback from the feedforward control and capturing both linear and nonlinear contributions. The causal synchronization, evaluating the ability of RR to predict SAP (χs/t) or vice versa (χt/s), and the global synchronization (χ) were estimated at rest and after head-up tilt in 35 post-AMI patients, 20 young and 12 old. Significance and nonlinearity of the coupling were assessed by surrogate data analysis. Tilting increased the number of young subjects in which RR-SAP link was significant (from 17…
Boris Ephrussi and the Synthesis of Genetics and Embryology
1991
The career of Boris Ephrussi (1901–1979) presents a series of fascinating perspectives on the intellectual and sociological difficulties that plagued those who wished to reconcile genetics and embryology during the middle of this century (2–8). Ephrussi was born in a suburb of Moscow, but spent much of his working career in France, with important periods in the United States. He made major contributions to the rapprochement between genetics and developmental biology. His work, which we believe has been undervalued both by historians of biology and by subsequent generations of biologists, is worth studying for at least three reasons: 1. Throughout his long career, he sought an adequate causa…