Current techniques in postmortem imaging with specific attention to paediatric applications

In this review we discuss the decline of and current controversies regarding conventional autopsies and the use of postmortem radiology as an adjunct to and a possible alternative for the conventional autopsy. We will address the radiological techniques and applications for postmortem imaging in childre

How to assess the existence of competing strategies in cognitive tasks: a primer on the fixed-point property

When multiple strategies can be used to solve a type of problem, the observed response time distributions are often mixtures of multiple underlying base distributions each representing one of these strategies. For the case of two possible strategies, the observed response time distributions obey the fixed-point property. That is, there exists one reaction time that has the same probability of being observed irrespective of the actual mixture proportion of each strategy. In this paper we discuss how to compute this fixed-point, and how to statistically assess the probability that indeed the observed response times are generated by two competing strategies. Accompanying this paper is a free R package that can be used to compute and test the presence or absence of the fixed-point property in response time data, allowing for easy to use tests of strategic behavior

A structural view of Pd model catalysts : high-pressure surface X-Ray diffraction

This thesis describes the development of a combined high-pressure/ultrahigh-vacuum flow reactor for the study of model catalysts by means of surface x-ray diffraction and grazing incidence small angle scattering. The system was used to measure a stability diagram for the different oxide phases (surface oxide, bulk-like oxides) that exist on Pd(100) during catalytic CO oxidation at near ambient pressures. As soon as an oxide was present the reactivity of the surface was found to be mass transfer limited by the flux of CO molecules reaching the surface. Experiments on spontaneous reaction oscillations of the CO oxidation rate on Pd(100) reveal that a high density of steps strongly alters the stability of the thin, catalytically active palladium oxide film. It is shown that stabilization of the metal, caused by the steps and consequent destabilization of the oxide, is at the heart of the well-known reaction rate oscillations exhibited during CO oxidation at atmospheric pressure. Lastly reaction oscillations on supported Pd nanoparticles are shown to be accompanied by shape changes of the particles consistent with the formation and removal of a thin palladium oxide film on the particles.LEI Universiteit LeidenQuantum Matter and Optic

Exploration of the Rate of Forgetting as a Domain-Specific Individual Differences Measure

Learners differ in their learning aptitude. Modern computerized fact-learning systems take these individual differences into account by adapting repetition schedules to the learner's characteristics. Adaptation is based on monitoring responses during learning and using these responses to inform the model's decisions about when to introduce and repeat material by updating the model's internal parameters. Typically, adaptive systems start a learning session with a set of default parameters, with these parameters being updated and adapted to the learner's characteristics when responses are collected. Here we explore whether domain-general individual differences such as working-memory capacity or measures of general intelligence, which can be assessed prior to learning sessions, can inform the choice of initial model parameters. Such an approach is viable if the domain-general individual differences are related to the model parameters estimated during learning. In the current study, we asked participants to learn factual information, and assessed whether their learning performance, operationalized as (1) a model-parameter that captures the rate of forgetting, and (2) the results on an immediate and delayed post-test, was related to two common measures of individual differences: working memory capacity (WMC) and general cognitive ability (GCA). We failed to find evidence in favor for such relations, suggesting that, at least in this relatively small and homogeneous sample, executive functioning and attentional control did not play important roles in predicting delayed recall. The model parameters estimated during learning, on the other hand, are highly correlated with delayed recall of the studied material