Given a vector space V and a non-singular quadratic form Q on V , the orthogonal group O(Q) is the subgroup of GL(V ) that preserves Q. The special orthogonal group SO(Q) is given by O(Q) ∩ SL(V ). If Q is the standard inner product on R then SO(Q) is denoted SO(n). This is a connected, compact Lie group. For n > 2, the group is semi-simple. In the case that n is odd, SO(n) corresponds to the D...

The micropylar endosperm cap covering the radicle in the mature seeds of most angiosperms acts as a constraint that regulates seed germination. Here, we report on a comparative seed biology study with the close Brassicaceae relatives Lepidium sativum and Arabidopsis thaliana showing that ethylene biosynthesis and signaling regulate seed germination by a mechanism that requires the coordinated a...

Interest in seed propagation of drumstick tree (Moringa oleifera) has created a need for information about the water relationships of its seeds. Thus, we studied the imbibition and desiccation kinetics and adsorption/ desorption isotherms of drumstick tree seeds. Seeds absorbed water readily when imbibed at 23oC. After 17 h of exposure to an atmosphere of 100% relative humidity (RH), seed moist...

The regulation of lipid synthesis in oil seeds is still not fully understood. Oilseed rape (Brassica napus) is the third most productive vegetable oil crop on the global market; therefore, increasing our understanding of lipid accumulation in oilseed rape seeds is of great economic, as well as intellectual, importance. Matrix-assisted laser/desorption ionization-mass spectrometry imaging (MALDI...

We compute discrete convex hulls in 2D grey-level images, where we interpret grey-level values as heights in 3D landscapes. For these 3D objects, using a 3D binary method, we compute approximations of their convex hulls. Differently from other grey-level convex hull algorithms, producing results convex only in the geometric sense, our convex hull is convex also in the grey-level sense.

Let I (α) ≤ a. It was Taylor–Cavalieri who first asked whether hulls can be computed. We show that |s|−3 = 0−1. Is it possible to construct hulls? U. Newton [11] improved upon the results of V. Wang by extending hyper-nonnegative domains.

Relative convex hulls have been suggested for multigridconvergent surface area estimation. Besides the existence of a convergence theorem there is no efficient algorithmic solution so far for calculating 3D relative convex hulls. This article discusses an approximative solution based on minimum-length polygon calculations. It is illustrated that this approximative calculation also proves (exper...