1. Introduction This paper focuses on the properties of Schubert cells as semialgebraic subsets of a generalized ag variety. More speciically, we investigate the problem of distinguishing between diierent Schubert cells using vanishing patterns of generalized Pl ucker coordinates.

We show that there are exactly nine distinct PL involutions on the nonorientable 2-sphere bundle over Sl, up to PL equivalences. This, together with results of [1], [3] and [8], classifies all PL involutions on the 2sphere bundles over S1.

One of the crucial issues concerning the evolution of animal form is whether there is any general tendency as to the genetic and molecular mechanisms involved? A vast body of comparative studies has revealed that morphology evolves via changes in the spatial regulation of gene expression during development. So the question of the evolution of form boils down to one concerning the evolution of g...

We introduce a framework for an empirical evaluation of probabilistic logic languages and systems.

Using a standard fact in hyperbolic geometry, we give a simple proof of the uniqueness of PL minimal surfaces, thus filling in a gap in the original proof of Jaco and Rubinstein. Moreover, in order to clarify some ambiguity, we sharpen the definition of PL minimal surfaces, and prove a technical lemma on the Plateau problem in the hyperbolic space.

To investigate the properties of phagolysosome (PL) fusion in Acanthamoeba homogenates, it was necessary to develop reliable methods for measuring in vitro PL fusion. The need to distinguish PL fusion from PL adhesion was met by the development of a quantitative electron microscope assay. Initial characterization of the fusion reaction by this method was followed by the development of a more ra...

Abs&act-A 3 x 2 factorial experiment was performed to compare the effects of procedure format (none, internal, or external) with those of comments (absent or present) on the readability of a PL/I program. The readability of six editions of the program, each having a different combination of these factors, was inferred from the accuracy with which students could answer questions about the progra...

We introduce a metric notion of Ricci curvature for PL manifolds and study its convergence properties. We also prove a fitting version of the Bonnet-Myers Theorem, for surfaces as well as for a large class of higher dimensional manifolds.