Over the past few decades an exceedingly large number of experimental and clinical investigations have been performed in an attempt to analyze the way in which the kidney functions. The basis for all this work was established during the nineteenth and the early twentieth century by morphologists (Bowman 1842; Hyrtl1863, 1872; Heidenhain 1874; Peter 1909; von Mollendorf 1930). All these investigators clearly outlined the extremely heterogeneous assembly of renal tissue and also defined the nephron as the smallest morphological unit. It was further the merit of these anato mists and histologists to preclude quite a number of nephron functions based merely on their careful observations. Contemporary histologists have been able to add little to these observations. Unfortunately with the introduction of physiologic in vivo et situ studies on kidneys the interest in heterogeneity waned. This lack of attention was aggravated by the introduction of the clearance techniques which cannot account for regional differences in the function of the smallest unit, the nephron. That ana tomic heterogeneity has a functional correlate was strongly suggested by Trueta et al. (1947) and vigorously stimulated a number of studies. The development of physiologic microtechniques, like micropuncture and microperfusion of single nephrons, or the perfusion of isolated nephron portions and electrophysiologic studies, enormously expanded our knowledge concerning details regarding nephron and total renal func tion.

Unbiased Stereology, Second Edition is a practical guide to making unbiased 3-D measurements via the microscope. Only those stereological techniques which have been tried and tested by real application are included. Although this technology is essentially mathematical and statistical, the authors do not immerse the reader in complex analysis, but rather provide simple heuristic explanations and references to the original proof, and illustrate the theory by analogies drawn from everyday experience. To give practical experience in application of the techniques, exercises are provided at the end of each chapter, complete with detailed worked answers.

During recent years, people involved in developing new metals and materials for use in some of the rather extreme conditions of stress, temperature, and environment have relied heavily on the microstructural condition of their materials. In fact, many of the newer materials, such as dispersion-strengthened alloys, have been designed almost entirely by first determining the microstruc ture desired and then finding the right combination of composition, heat treatment, and mechanical working that will result in the de sired microstructure. Furthermore, the extremely high reliability required of materials used today, for example, in aerospace and nuclear energy systems, requires close control on the microstruc tural conditions of materials. This is clearly evident from even a cursory examination of recently written specifications for mate rials where rather precise microstructural parameters are stipu lated. Whereas specifications written several years ago may have included microstructural requirements for details such as ASTM grain size or graphite type, today's specifications are beginning to include such things as volume fraction of phases, mean free path of particles, and grain intercept distances. Rather arbitrary terms such as "medium pearlite" have been replaced by requirements such as "interlamella spacing not to exceed 0. 1 micron. " Finally, materials users have become increasingly aware that when a material does fail, the reason for its failure may be found by examining and "reading" its microstructure. The responsibility for a particular microstructure and a resulting failure is a matter of growing importance in current product liability consider ations.

New edition of an introductory reference that covers all of the important aspects of electron microscopy from a biological perspective, including theory of scanning and transmission; specimen preparation; darkroom, digital imaging, and image analysis; laboratory safety; interpretation of images; and an atlas of ultrastructure. Generously illustrated with bandw line drawings and photographs. Annotation copyrighted by Book News, Inc., Portland, OR

In this practical text, the author covers the fundamentals of biological electron microscopy - including fixation, instrumentation, and darkroom work - to provide an excellent introduction to the subject for the advanced undergraduate or graduate student.