Intelligence, collaboration and mobility are the main important features in designing agents for electronic commercial systems. But very few systems permit to implement agents which have all these characteristics. In this paper, we address the problems of designing intelligent collaborative mobile agents. We propose a componential approach for designing and implementing such agents. Our framewo...

Triadic distances t defined as functions of the Euclidean (dyadic) distances a1, a2, a3 between three points are studied. Special attention is paid to the contours of all points giving the same value of t when a3 is kept constant . These isocontours allow some general comments to be made about the suitability, or not, for practical investigations of certain definitions of triadic distance. We a...

In this paper, we examine the evolution of triadic motifs in a large-scale human communication network. We consider extant models of triadic evolution, emphasizing vertex-, dyadic-, triadicand higher-level processes in order to generate testable hypotheses of the predictors of both over time triangle survival and triangle emergence from lower-order motifs. We find that the stability and formati...

Members of the Lef/Tcf family of HMG-box transcription factors mediate the response to Wnt as part of the canonical Wnt signaling cascade. Positive and negative cofactors, including beta-catenin, CtBP, and Smad3, regulate the activity of Lef/Tcf transcription complexes. Interaction of Lef/Tcfs with beta-catenin results in target gene activation or repression, depending on the context. Here, we ...

Lymphoid enhancer factor/T-cell factor (LEF/TCF) are transcription factors that mediate the Wnt signaling pathway, and have crucial roles during embryonic development in various organisms. Here we report that acetylation enhances nuclear retention of POP-1, the Caenorhabditis elegans LEF/TCF homolog, through increasing nuclear import and blocking nuclear export. We identify three lysines that a...

The past 25 years have witnessed an increasing awareness of the importance of cognitive control in the regulation of complex behavior. It now sits alongside attention, memory, language, and thinking as a distinct domain within cognitive psychology. At the same time it permeates each of these sibling domains. This introduction reviews recent work on cognitive control in an attempt to provide a c...

The transforming growth factor-beta (TGFbeta) and Wnt/wingless pathways play pivotal roles in tissue specification during development. Activation of Smads, the effectors of TGFbeta superfamily signals, results in Smad translocation from the cytoplasm into the nucleus where they act as transcriptional comodulators to regulate target gene expression. Wnt/wingless signals are mediated by the DNA-b...

We investigated the relationship among ERK signaling, histone modifications, and transcription factor activity, focusing on the ERK-regulated ternary complex factor family of SRF partner proteins. In MEFs, activation of ERK by TPA stimulation induced a common pattern of H3K9acS10ph, H4K16ac, H3K27ac, H3K9acK14ac, and H3K4me3 at hundreds of transcription start site (TSS) regions and remote regul...

The transactivation of TCF target genes induced by Wnt pathway mutations constitutes the primary transforming event in colorectal cancer (CRC). We show that disruption of beta-catenin/TCF-4 activity in CRC cells induces a rapid G1 arrest and blocks a genetic program that is physiologically active in the proliferative compartment of colon crypts. Coincidently, an intestinal differentiation progr...

Flow cytometric and immunocytochemical analyses of murine fetal thymus (FT) cells with antibodies to various surface markers and transcription factors reveal that the synthesis of TCF-1 and GATA-3 protein begins simultaneously in a fraction of the most immature population of FT cells, which have the phenotype of CD4-CD8-CD44+CD25-. No TCF-1-producing cells is found in the fetal liver (FL). In C...