1. MOTIVATION Grammar inference is a challenging problem for statistical approaches to natural-language processing. The most successful grammar inference techniques involve stochastic finite-state language models such as hidden Markov models (HMMs) [1]. However, finite-state language models fail to represent the hierarchical structure of natural language. Therefore, stochastic versions of gramm...

rons and a corresponding convergence of information A wide expanse of the visual environment, typically clutas an increasing number of objects can fit within each tered with visual information, is encoded by the retinae receptive field. This confluence would seem to lead inand passed to the central visual system. How do we variably to an inseparable mixture of information from integrate and coo...

In many problems in commonsense reasoning and intelligent manufacturing, we need to reason about cutting, joining, and folding sheets of materials such as cardboard and metal. In this paper we introduce a first-order ontology of shape (called BoxWorld) that can support these applications. We reuse an existing ontology of shape for object recognition with 2D shapes (called CardWorld) and extend ...

Neurotoxicity of beta-amyloid peptide (A beta) in Alzheimer's disease (AD) is usually thought to arise from the nonspecific effects of high concentrations of A beta on vulnerable neurons, resulting in membrane destabilization and increasing intracellular calcium concentration. This review advances the hypothesis that at early stages of AD, when A beta is present in lower amounts, its ability to...

In the early 1990s, after its Jupiter flyby, the Ulysses spacecraft identified interstellar dust in the solar system. Since then the in-situ dust detector on board Ulysses continuously monitored interstellar grains with masses up to 10−13 kg, penetrating deep into the solar system. While Ulysses measured the interstellar dust stream at high ecliptic latitudes between 3 and 5 AU, interstellar im...

Chronological age is but one, and not the most accurate, indicator of human aging. Multiple outside (i.e., objective) and inside (i.e., subjective) perspectives on aging need to be considered to do justice to the multidimensionality of human development and aging. Outside perspectives are, for example, biological, social, and psychological ages. A chronological age of 75 years, for instance, ma...