A new modelling framework for statistical cumulus dynamics

We propose a new modelling framework suitable for the description of atmospheric convective systems as a collection of distinct plumes. The literature contains many examples of models for collections of plumes in which strong simplifying assumptions are made, a diagnostic dependence of convection on the large-scale environment and the limit of many plumes often being imposed from the outset. Some recent studies have sought to remove one or the other of those assumptions. The proposed framework removes both, and is explicitly time-dependent and stochastic in its basic character. The statistical dynamics of the plume collection are defined through simple probabilistic rules applied at the level of individual plumes, and van Kampen's system size expansion is then used to construct the macroscopic limit of the microscopic model. Through suitable choices of the microscopic rules, the model is shown to encompass previous studies in the appropriate limits, and to allow their natural extensions beyond those limits

Analytical results for a Fokker-Planck equation in the small noise limit

We present analytical results for the lowest cumulants of a stochastic process described by a Fokker-Planck equation with nonlinear drift. We show that, in the limit of small fluctuations, the mean, the variance and the covariance of the process can be expressed in compact form with the help of the Lambert W function. As an application, we discuss the interplay of noise and nonlinearity far from equilibrium.Comment: 5 pages, 4 figure

The Dutch DAPP-BQ: improvements, lower- and higher-order dimensions, and relationship with the 5DPT.

Jackson, 2002), the present DAPP-BQ scales (with or without Self-Harm included) were subjected to a principal components analysis with oblimin or varimax rotation in a general population sample of 478 subjects, retaining four factors. All four (higherorder) factors (Emotional Dysregulation, Dissocial, Inhibition, and Compulsivity) proved identical to the factors originally derived in Canada, with Tucker coefficients of factor similarity approaching unity. Particularly the (unexpected) finding that the present Dutch version of the DAPP-BQ also resulted in an Inhibition factor (and not, like the former Dutch version, in an Intimacy Problems factor) was considered positive. In addition, a principal components analysis with oblimin rotation was conducted on the 282 items contained in the 18 DAPP-BQ scales, investigating the lower-order structure of the DAPP-BQ; in this case, 18 factors were retained. Although the structure originally derived by Livesley and colleagues could not be recovered completely, the degree of similarity was of such a magnitude that the 18 DAPP-BQ scales were considered to give a dependable account of the “true” lower-order structure of disordered personality. Moreover, based on the finding that the 18 scales are sufficiently reliable (Cronbach's alpha) and correlate as predicted in a subsample of 284 subjects with the normal personality scales of Van Kampen's 5DPT (or, Five-Dimensional Personality Test), the DAPP-BQ appears to be a valuable instrument

The 5-Dimensional Personality Test (5DPT): Relationships with Two Lexically Based Instruments and the Validation of the Absorption Scale

Although intended to assess vulnerability factors associated with psychopathology, the 5-Dimensional Personality Test (5DPT) shows at least a superficial similarity to instruments that adhere to the lexical tradition in personality psychology. To investigate to which extent this similarity goes, this article compares the 5DPT with 2 lexically based measures, the NEO-Five Factor Inventory and the HEXACO-Personality Inventory-Revised. Moreover, as the NEO Openness to Experience construct demonstrates little relationship with maladaptive personality, whereas the 5DPT Absorption factor was hypothesized to underlie the emergence of positive schizotypic symptoms and related phenomena, the 5DPT was also correlated with the Schizotypic Syndrome Questionnaire (SSQ), the Creative Experiences Questionnaire, Thalbourne's Transliminality Scale, the Launay-Slade Hallucination Scale, and the OLIFE-Unusual Experiences scale. On examining the correlations between the various instruments, it was ascertained (a) that there is no need to extend the theory-informed 5DPT with a 6th dimension similar to the HEXACO factor Honesty-Humility, (b) that the 5DPT dimensions were found on average to share only a moderate amount of variance with the Five-factor model/Big Five factors, and (c) that the 5DPT Absorption scale turned out as anticipated to correlate with the positive symptom scales of the SSQ, as well as with the remaining criterion scales that measure similar constructs. © 2012 Copyright Taylor and Francis Group, LLC

Genetic and Environmental Influences on Pre-schizophrenic personality: MAXCOV-HITMAX and LISREL Analyses.

Postulating that the predisposition to illness in Claridge's disease model of schizophrenia can be equated with the personality dimensions S or Insensitivity, (low) E or Extraversion, and N or Neuroticism, as measured by Van Kampen's 3DPT, and assuming that the mode of transmission of schizophrenia is basically polygenic, the genetic and environmental etiology of S, E, and N was assessed in a sample of 52 MZ and 76 DZ twin pairs and their parents by means of LISREL. Besides, in a sample of 2118 subjects MAXCOV–HITMAX analyses were conducted for these factors as well as for the personality dimension G or Orderliness, but now assessed by the 4DPT, in order to find out whether a discrete or quasi-discrete variable might also underlie these dimensions, giving support to the possibility of dominance or epistasis. The results obtained in these investigations favoured a model for all three dimensions, allowing for both additive and non-additive genetic effects in combination with non-shared environmental influences. It was not possible to choose between a model involving dominance and a model involving epistatic genetic effects. With the use of scores corrected for sex and age, which were converted to normal scores, the proportion of variance explained by additive genetic factors was 20% for S, 40–41% for E, and 26–29% for N. Dominance or multiple-gene epistasis accounted for 37–38% (S), 19–20% (E), and 30–31% (N), and unshared environmental influences for 42–43% (S), 41% (E), and 42–43% (N) respectively

Slow transport by continuous time quantum walks

Continuous time quantum walks (CTQW) do not necessarily perform better than their classical counterparts, the continuous time random walks (CTRW). For one special graph, where a recent analysis showed that in a particular direction of propagation the penetration of the graph is faster by CTQWs than by CTRWs, we demonstrate that in another direction of propagation the opposite is true; In this case a CTQW initially localized at one site displays a slow transport. We furthermore show that when the CTQW's initial condition is a totally symmetric superposition of states of equivalent sites, the transport gets to be much more rapid.Comment: 5 pages, 7 figures, accepted for publication in Phys. Rev.

Compaction and tensile forces determine the accuracy of folding landscape parameters from single molecule pulling experiments

We establish a framework for assessing whether the transition state location of a biopolymer, which can be inferred from single molecule pulling experiments, corresponds to the ensemble of structures that have equal probability of reaching either the folded or unfolded states (Pfold = 0.5). Using results for the forced-unfolding of a RNA hairpin, an exactly soluble model and an analytic theory, we show that Pfold is solely determined by s, an experimentally measurable molecular tensegrity parameter, which is a ratio of the tensile force and a compaction force that stabilizes the folded state. Applications to folding landscapes of DNA hairpins and leucine zipper with two barriers provide a structural interpretation of single molecule experimental data. Our theory can be used to assess whether molecular extension is a good reaction coordinate using measured free energy profiles.Comment: 6 pages, 4 figures, Phys. Rev. Lett. (in press

Anderson localization as a parametric instability of the linear kicked oscillator

We rigorously analyse the correspondence between the one-dimensional standard Anderson model and a related classical system, the `kicked oscillator' with noisy frequency. We show that the Anderson localization corresponds to a parametric instability of the oscillator, with the localization length determined by an increment of the exponential growth of the energy. Analytical expression for a weak disorder is obtained, which is valid both inside the energy band and at the band edge.Comment: 7 pages, Revtex, no figures, submitted to Phys. Rev.

Holomorphic transforms with application to affine processes

In a rather general setting of It\^o-L\'evy processes we study a class of transforms (Fourier for example) of the state variable of a process which are holomorphic in some disc around time zero in the complex plane. We show that such transforms are related to a system of analytic vectors for the generator of the process, and we state conditions which allow for holomorphic extension of these transforms into a strip which contains the positive real axis. Based on these extensions we develop a functional series expansion of these transforms in terms of the constituents of the generator. As application, we show that for multidimensional affine It\^o-L\'evy processes with state dependent jump part the Fourier transform is holomorphic in a time strip under some stationarity conditions, and give log-affine series representations for the transform.Comment: 30 page