Modulation of an activity response with associative and nonassociative fear in the rat: A lighting differential influences the form of defensive behavior evoked after fear conditioning

Rats confronted with the onset of a light gradient display a transient increase in locomotion called theactivity response (AR) and a dark preference (Godsil & Fanselow, 2004). These experiments demonstrate that the magnitude of the AR can be blunted with Pavlovian fear-conditioning procedures via associative and nonassociative fear. Although manifested in decreased locomotion, the blunted AR effect was not due to increased freezing or immobility behaviors. Instead, rats displayed reduced rearing and an increase in a class of behaviors calledstationary activity. These results suggest that the lighting differential supplied by the cue influences the topography of defensive behavior and reduces the expression of freezing. This procedure provides a means by which to examine learned and unlearned defensive responses to the same stimulus.     

Modeling Strain Rate Effect for Heterogeneous Brittle Materials

Rocks are heterogeneous from the point of microstructure which is of significance to their dynamic failure behavior. Both the compressive and tensile strength of rock-like materials is regarded different from the static strength. The present study adopts smoothed particle hydrodynamics (SPH) which is a virtual particle based meshfree method to investigate strain rate effect for heterogeneous brittle materials. The SPH method is capable of simulating rock fracture, free of the mesh constraint of the traditional FEM and FDM models. A pressure dependent J-H constitutive model involving heterogeneity is employed in the numerical modeling. The results show the compressive strength increases with the increase of strain rate as well as the tensile strength, which is important to the engineering design.     

Reconstruction from contour lines based on bi-cubic Bézier spline surface

INTRODUCTION In many research and application areas such as medical science, biomedical engineering, and CAD/ CAM, an object is often known by a sequence of 2D cross-sections. With improvements in data acquisi- tion and imaging techniques such as computed to- mography (CT), magnetic resonance imaging (MRI), and ultrasound imaging, the cross-sectional images of the object of interest can be obtained with ease. The object in every 2D cross-section can be represented by the contour line…     

Different kinds of information affect word learning in the preschool years: the case of part-term learning

Two studies investigated how preschool children's interpretations of novel words as names for parts of objects were affected by 3 kinds of information: (a) whole object familiarity, (b) whole part juxtaposition, and (c) syntactic information indicating possession. Study 1 tested 3- to 4-year-olds and found that although there was evidence that all information affected children's part-term interpretations to some extent, they were most systematic when provided with 2 or more kinds of information. Study 2 adapted the procedure for use with 2.5-year-olds and found the same general pattern of results. Variations across studies were found that may reflect changes in how different kinds of information affect word learning with development.     

Relationally and physically aggressive children's intent attributions and feelings of distress for relational and instrumental peer provocations

Numerous studies have demonstrated that physically aggressive children exhibit hostile attributional biases in response to instrumental peer provocations, a social information-processing pattern that has been recognized as a contributor to peer-directed aggression. The present studies (N = 127 and N = 535) were designed to extend past research by evaluating the intent attributions and feelings of emotional distress of relationally and physically aggressive children in response to instrumental and relational provocation contexts. Results indicated that physically aggressive children exhibited hostile attributional biases and reported relatively greater distress for instrumental provocation situations, whereas relationally aggressive children exhibited hostile attributional biases and reported relatively greater distress for relational provocation contexts. Implications of these findings for the understanding of factors that may contribute to relational as well as physical aggression are discussed.