Stereological estimation of mean particle volume tensors in R³ from vertical sections

In this chapter, we discuss stereological estimation of mean particle volume tensors in R³ from vertical sections. We consider a particle process of compact particles that can be represented as a stationary marked point process. Under the assumption that the particle distribution is invariant under rotations around a fixed axis, called the vertical axis, we show how the mean particle volume tensors can be estimated consistently (in a probabilistic sense) from observations in vertical sections through a sample of particles. In a simulation study, the new estimator has a superior behaviour compared to an earlier estimator based on observations in several optical planes

Stereological estimation of particle shape and orientation from volume tensors

In the present paper, we describe new robust methods of estimating cell shape and orientation in 3D from sections. The descriptors of 3D cell shape and orientation are based on volume tensors which are used to construct an ellipsoid, the Miles ellipsoid, approximating the average cell shape and orientation in 3D. The estimators of volume tensors are based on observations in several optical planes through sampled cells. This type of geometric sampling design is known as the optical rotator. The statistical behaviour of the estimator of the Miles ellipsoid is studied under a flexible model for 3D cell shape and orientation. In a simulation study, the lengths of the axes of the Miles ellipsoid can be estimated with CVs of about 2% if 100 cells are sampled. Finally, we illustrate the use of the developed methods in an example, involving neurons in the medial prefrontal cortex of rat