A self-organizing architecture is developed for image region classification. The system consists of a preprocessor that utilizes multiscale filtering, competition, cooperation, and diffusion to compute a vector of image boundary and surface properties, notably texture and brightness properties. This vector inputs to a system that incrementally learns noisy multidimensional mappings and their pr...

By the time ofMontgomery's classic paper on the nucleolus in 1898 (1), there were already 700 or so articles with observations on this nuclear organelle, beginning with a study by Fontana in 1781 entitled "Venom of Vipers." The early cytological emphasis on the nucleolus undoubtedly was due to the high visibility of the organelle in interphase nuclei ofmost cell types ; however, the fact that n...

Budding yeast Cdc14 phosphatase plays essential roles in mitotic exit. Cdc14 is sequestered in the nucleolus by its inhibitor Net1/Cfi1 and is only released from the nucleolus during anaphase to inactivate mitotic CDK. It is believed that the mitotic exit network (MEN) is required for the release of Cdc14 from the nucleolus because liberation of Cdc14 by net1/cfi1 mutations bypasses the essenti...

The eukaryotic nucleolus is multifunctional and involved in the metabolism and assembly of many different RNAs and ribonucleoprotein particles as well as in cellular functions, such as cell division and transcriptional silencing in plants. We previously showed that Arabidopsis thaliana exon junction complex proteins associate with the nucleolus, suggesting a role for the nucleolus in mRNA produ...

Viruses are suspected of significant roles in autoimmune diseases but the mechanisms are unclear. We get some insight by considering demands a virus places on host cells. Viruses not only require production of their own proteins, RNA and/or DNA, but also production of additional cellular machinery, such as ribosomes, to handle the increased demands. Since the nucleolus is a major site of RNA pr...

The nucleolus of an average mammalian cell can produce up to 10,000 ribosomes per min. Each cell contains hundreds of copies of rDNA in the form of tandem repeats, and 400 rDNA repeats are spread out on five pairs of chromosomes in human cells. At any given time, only a subset of rDNA repeats is actively being transcribed. Miller spreads (electron microscopic visualization of RNA being synthesi...

The nucleus is a highly organized structure. However, unlike cytoplasmic organelles, nuclear substructures are not bounded by membranes, but rather are held together by interactions between their component proteins and nucleic acids, and are thus probably best regarded as giant, extended multimolecular complexes. The nucleolus is themost prominent of these structures. It is the site of transcri...

In a beautiful novel, the Argentinian writer Jorge Luis Borges `quotes' a Chinese saying `̀ dejo a los varios porveniresöno a todosöeste jard|̈n de senderos que se bifurcan'' (`̀ I leave to the various futuresönot to allöthis garden of forking paths'') (Borges, 1994). The solution to the detective novel lies in the nature of the garden and of his labyrinth: the forks happen in time, not in space; ...

A self-organizing approach is proposed for gene finding based on the model of codon usage for coding regions and positional preference for noncoding regions. The symmetry between the direct and reverse coding regions is adopted for reducing the number of parameters. Without requiring prior training, parameters are estimated by iteration. By employing the window sliding technique and likelihood ...