ABSTRACT
Path reweighting is a principally exact method to estimate dynamic properties from biased simulations-provided that the path probability ratio matches the stochastic integrator used in the simulation. Previously reported path probability ratios match the Euler-Maruyama scheme for overdamped Langevin dynamics. Since molecular dynamics simulations use Langevin dynamics rather than overdamped Langevin dynamics, this severely impedes the application of path reweighting methods. Here, we derive the path probability ratio ML for Langevin dynamics propagated by a variant of the Langevin Leapfrog integrator. This new path probability ratio allows for exact reweighting of Langevin dynamics propagated by this integrator. We also show that a previously derived approximate path probability ratio Mapprox differs from the exact ML only by O(ξ4Δt4) and thus yields highly accurate dynamic reweighting results. (Δt is the integration time step, and ξ is the collision rate.) The results are tested, and the efficiency of path reweighting is explored using butane as an example.
ABSTRACT
72 case histories of former adolescent psychiatric inpatients diagnosed on discharge as suffering from a personality disorder were evaluated. It was possible to re-examine 33 (46%) of them. The discharge diagnosis was made according to ICD 9, the follow-up diagnosis according to ICD 10 and DSM-III-R. Depending on the instrument and criterion, 40% to 87.9% of the discharge diagnoses made could be confirmed after an average follow-up period of 3.4 years. Only in 12.1% of the cases there was no personality disorder established. There was no indication of any change of diagnosis to other psychiatric disorders. The re-diagnosis rates obtained are thus similar to those for adults. The classifications of ICD 10 and DSM-III-R corresponded much better than those of ICD 9 to clinical reality. The classification systems and assessment instruments that have normally been verified only for adults thus also seem suitable for use among adolescents. In both adolescents and adults the avoidant personality disorder is a particularly frequent subtype. However, the current study was unable to resolve the question of what the decisive criteria should be in the case of competing definitions such as puberty crisis, personality development disorder, personality disorder and emotional or affective disorder. This issue requires further investigation.
