Mother-Infant Observations: A View into the Wordless Social Instincts that Form the Foundation of Human Psychodynamics.

Mother-infant observations attune the psychotherapist to the nonverbal interactions that shape the child's experience of the world. The origins of our interest in psychoanalytic mother-infant observations can be traced back to clinical work with adults, child analyses, ethology (the study of animal behavior), and theoretical questions about the development of the symbolic function in infancy. More recently, seminars and direct experience in mother-infant observation have been gaining popularity as components of psychoanalytic training.

Transcription factor binding predicts histone modifications in human cell lines.

Gene expression in higher organisms is thought to be regulated by a complex network of transcription factor binding and chromatin modifications, yet the relative importance of these two factors remains a matter of debate. Here, we show that a computational approach allows surprisingly accurate prediction of histone modifications solely from knowledge of transcription factor binding both at promoters and at potential distal regulatory elements. This accuracy significantly and substantially exceeds what could be achieved by using DNA sequence as an input feature.

Asymptotic results for backwards two-particle dispersion in a turbulent flow.

We derive an exact equation governing two-particle backwards mean-squared dispersion for both deterministic and stochastic tracer particles in turbulent flows. For the deterministic trajectories, we probe the consequences of our formula for short times and arrive at approximate expressions for the mean-squared dispersion which involve second order structure functions of the velocity and acceleration fields. For the stochastic trajectories, we analytically compute an exact t3 contribution to the squared separation of stochastic paths.

Diffusion approximation in turbulent two-particle dispersion.

We solve an inverse problem for fluid particle pair statistics: we show that a time sequence of probability density functions (PDFs) of separations can be exactly reproduced by solving the diffusion equation with a suitable time-dependent diffusivity. The diffusivity tensor is given by a time integral of a conditional Lagrangian velocity structure function, weighted by a ratio of PDFs. Physical hypotheses for hydrodynamic turbulence (sweeping, short memory, mean-field) yield simpler integral formulas, including one of Kraichnan and Lundgren (K-L).