Noise-cancellation algorithm for simulations of Brownian particles.

We investigate the usage of a recently introduced noise-cancellation algorithm for Brownian simulations to enhance the precision of measuring transport properties such as the mean-square displacement or the velocity-autocorrelation function. The algorithm is based on explicitly storing the pseudorandom numbers used to create the randomized displacements in computer simulations and subtracting them from the simulated trajectories. The resulting correlation function of the reduced motion is connected to the target correlation function up to a cross-correlation term. Using analytical theory and computer simulations, we demonstrate that the cross-correlation term can be neglected in all three systems studied in this paper. We further expand the algorithm to Monte Carlo simulations and analyze the performance of the algorithm and rationalize that it works particularly well for unbounded, weakly interacting systems in which the precision of the mean-square displacement can be improved by orders of magnitude.

The nature and nurture of resilience-reactions of trizygotic triplet minors to their father's death.

BACKGROUND: Parental bereavement during childhood is associated with an elevated risk for the development of psychiatric problems. This paper seeks to provide insight into the adjustment process of trizygotic triplets dealing with their father's death, thus, trying to give an impression of the individual nature of grief and resilience. METHODS: We examined 11-year-old trizygotic triplets (2 boys and 1 girl) concerning behavioral problems (CBCL/6-18R, YSR/11-18R), posttraumatic stress disorder (UCLA PTSD Index for DSM­5, UPID), depression ("Depressionsinventar für Kinder und Jugendliche," DIKJ), and fear ("Phobiefragebogen für Kinder und Jugendliche," PHOKI) shortly after their father's death and 6 months later. The girl was developmentally delayed and had moderate intellectual disability, while her brothers' development was age-appropriate. RESULTS: The triplets showed very different adjustment to the traumatic event. While the boys showed less psychopathological response to their loss shortly after their father's death and adjusted physiologically during the following 6 months, their sister scored high in almost all dimensions and still presented with notable psychopathological symptoms at the 6­month follow-up. CONCLUSION: Outcomes differ distinctly despite objectively equal risk and protective factors. While it is known that above average intellectual abilities represent a protective factor for posttraumatic stress, these results show that intellectual retardation might be a prominent yet understudied risk factor in dealing with postbereavement psychopathology in children.

Research in minors with a recent history of trauma-A bold venture?

Little research has been performed so far on the mental health state of grieving and recently traumatized children. "The Buoy" ("Die Boje"), a low threshold ambulatory provides non-bureaucratic help and short time psychotherapy to children and adolescents in need of professional support at no charge and treats about 1400 minors per year. Whilst performing a study on these patients with special regard to their social network, we found the process of recruitment to be extraordinarily challenging. Only about 25% of the eligible patients could be recruited successfully within during the period of one year. In this paper we try to examine the barriers we had to overcome in gaining access to the sensitive field of grieving and traumatized children and adolescents who rely on low threshold psychotherapeutic and neuropsychiatric support and analyze the factors leading to the high number of dropouts. In addition, the consequences for our results will be discussed.