Importance sampling-based algorithms are a popular alternative when Bayesian network models are too large or too complex for exact algorithms. However, importance sampling is sensitive to the quality of the importance function. A bad importance function often leads to much oscillation in the sample weights, and, hence, poor estimation of the posterior probability distribution. To address this p...

Using a multivariable Faa di Bruno formula we give conditions on transformations τ : [0, 1] → X where X is a closed and bounded subset of R such that f ◦ τ is of bounded variation in the sense of Hardy and Krause for all f ∈ C(X ). We give similar conditions for f◦τ to be smooth enough for scrambled net sampling to attain O(n−3/2+ ) accuracy. Some popular symmetric transformations to the simple...

In three well-designed experiments, Schneider et al. (2014) demonstrate that the importance ascribed to the content influences weight perception of a USB or of a data-storage device. I will briefly discuss the theoretical implications of these results for the recent debate on “penetrability” of perception and then more generally for embodied and grounded views of cognition; finally I will argue...

The weight window variance reduction method in the general-purpose Monte Carlo N-Particle radiation transport code MCNP has recently been rewritten. In particular, it is now possible to generate weight window importance functions on a superimposed mesh, eliminating the need to subdivide geometries for variance reduction purposes. Our assessment addresses the following questions: (1) Does the n...

BACKGROUND Although the effectiveness of prednisolone therapy for severe hyperemesis gravidarum has been demonstrated, there is no consensus on how to assess severity to justify such treatment, nor any information on whether such therapy affects birth weight. AIM To document the effect of prednisolone therapy in women with defined severity of hyperemesis gravidarum. DESIGN Single centre, ob...

The [PSI+] determinant of Saccharomyces cerevisiae, consisting of the cytosolic translation termination factor Sup35, is a prion-type genetic element that induces an inheritable conformational change and converts the Sup35 protein into amyloid fibers. The molecular chaperone Hsp104 is required to maintain self-replication of [PSI+]. We observe in vitro that addition of catalytic amounts of Hsp1...

We present a practical bias correction method for classifier and regression models learning under a general class of selection bias. The method hinges on two assumptions: 1) a feature vector, Xs, exists such that S, the variable that controls the inclusion of the samples in the training set, is conditionally independent of (X,Y ) given Xs; 2) one has access to some external samples drawn from t...

We analysed the relationship between seed traits (weight, shape and dispersal structures) and the abundance and habitat segregation of Mediterranean grassland species. To take into account possible correlations with other plant traits, the study also includes 5 vegetative traits (growth form, plant longevity, clonality, onset of flowering and plant size) of commonly accepted functional importan...