Learn More
Chromosome orientation and behavior during prometaphase of mitosis in PtK1 rat kangaroo cells were investigated by cinémicrography and electron microscopy. The first chromosome movements occur soon after the nuclear envelope begins to break down in the region near each pole. Initial chromosome behavior is primarily determined by the distance from the(More)
Ten mitotic spindles from Dictyostelium discoideum have been studied by electron microscopy of serial sections. We have used computer graphics to track individual microtubules (MTs) in three dimensions and to compare seven spindles at different stages of anaphase and telophase. The central spindle of early anaphase is formed by the interdigitation of two(More)
This paper describes a mini-experiment in using a tool for semantic annotation to index photographs of Windsor chairs, a type of antique furniture. The annotation tool makes use of an ontology based on art standards. We report on the experiences of subjects using the tool. The results suggest that a certain level of domain expertise is needed for semantic(More)
We studied mitosis in vegetative amebae of Dictyostelium discoideum by phase-contrast microscopy of live and flat-embedded cells, by time-lapse microcinematography, and by electron microscopy of ultrathin sections. The mean time from early prophase to the end of cytokinesis was 10 min 32 s (range: 6 min 23 s to 15 min 40 s). The start of anaphase divided(More)
We have analyzed transparencies of electron micrographs from ultrathin longitudinal sections through mitotic spindles of undifferentiated amebae of Dictyostelium discoideum for the presence of arms on microtubules (MTs) and bridges between them. We used the technique of microdensitometer scanning and computer-based model matching by cross-correlation and(More)
  • 1