Reduced K+ Channel Inactivation, Spike Broadening, and After-Hyperpolarization in Kvβ1.1-Deficient Mice with Impaired Learning

A-type K⁺ channels are known to regulate neuronal firing, but their role in repetitive firing and learning in mammals is not well characterized. To determine the contribution of the auxiliary K⁺ channel subunit Kvβ1.1 to A-type K⁺ currents and to study the physiological role of A-type K⁺ channels in repetitive firing and learning, we deleted the Kvβ1.1 gene in mice. The loss of Kvβ1.1 resulted in a reduced K⁺ current inactivation in hippocampal CA1 pyramidal neurons. Furthermore, in the mutant neurons, frequency-dependent spike broadening and the slow afterhyperpolarization (sAHP) were reduced. This suggests that Kvβ1.1-dependent A-type K⁺ channels contribute to frequency-dependent spike broadening and may regulate the sAHP by controlling Ca²⁺ influx during action potentials. The Kvβ1.1-deficient mice showed normal synaptic plasticity but were impaired in the learning of a water maze test and in the social transmission of food preference task, indicating that the Kvβ1.1 subunit contributes to certain types of learning and memory.     

Recognition times of different views of 56 depth-rotated objects: A note concerning Verfaillie and Boutsen (1995)

The present study examines the effect of thegoodness of view on the minimal exposure time required to recognize depth-rotated objects. In a previous study, Verfaillie and Boutsen (1995) derived scales of goodness of view, using a new corpus of images of depth-rotated objects. In the present experiment, a subset of this corpus (five views of 56 objects) is used to determine the recognition exposure time for each view, by increasing exposure time across successive presentations until the object is recognized. The results indicate that, for two thirds of the objects,good views are recognized more frequently and have lower recognition exposure times thanbad views.     

THEOLOGY IN AN EVOLUTIONARY MODE

Abstract. Evolution has become the standard way of understanding the world process. Theology has to express traditional faith in the context of the contemporary world. Since the common world view has profoundly changed, from a static world of being into a dynamic world of becoming, theology needs to change its language and its understanding of the universe as God's creation. This understanding of an evolving world is to be used as a theological source. Such a change of perspective necessitates a fundamental reconstructing of theology; for theology, such reconstructing means a renewed understanding of the Creator and of the Incarnation.     

PRAXIS: Brent’s algorithm for function minimization

Implementations of Brent’s (1973) PRincipal AXIS (PRAXIS) algorithm in the widely used C and PASCAL programming languages are presented. The algorithm minimizes a multivariate function without using derivatives. An example computer program that calculates a maximum likelihood estimate of the parameters of a psychometric function illustrates the use of the routine. Another algorithm, Localmin, also due to Brent (1973), efficiently finds the minimum of a univariate function. An example program uses this algorithm to estimate the polychoric correlation coefficient from a pxq table of observed frequencies.     

The processing of inflected words

Summary Is an inflected word identified by first decomposing it into stem plus suffix or, instead, is it recognized as a whole? Several lexical decision experiments studied the recognition of inflected words in English (a language with few inflections) and Serbo-Croatian (a heavily inflected language). If recognition depended on decomposition, preceding the inflection with a brief exposure of the stem (<100 ms) should have primed the lexical entry for the stem and, therefore, facilitated recognition of the whole inflected word that followed. It did not. It was also found that the speed of recognizing an inflected word was more strongly associated with the frequency of the whole inflected form than with the frequency of its stem. The results suggested that in word recognition, lexical contact is first made with the whole word form. Nevertheless, morphological decomposition may still occur in subsequent processing.     

Why do people factor?

This is a very simple explanation of factor analysis primarily for the factorial layman. The interpretation of factors and the comparisons of various factor solutions are illustrated with a hypothetical example so designed that the reader can visualize all the relationships in a two-dimensional graph.     

Storytellers and Scenario Spinners: Some Reflections on Religion and Science in Light of a Pragmatic, Evolutionary Theory of Knowledge

Asserting that both scientists and religious thinkers are involved in telling stories about the past and spinning scenarios about the future, I first compare and contrast the purposes of scientific and religious storytelling. Then, in light of some recent work on brain and language evolution, I offer a possible story about how humans might have become storytellers. Finally, I discuss how religious stories might be evaluated pragmatically and even scientifically by developing Lakatosian-type research programs.