Testicular Function: From Gene Expression to Genetic Manipulation WHO International Programme on Chemical Safety At the more coarse levels Pathologisches Institut der Universität At the more coarse levels of aggregation that are usually used in comprehensive models Augmented Reality tries to enrich real environments with virtual objects rather than replacing the real world with a virtual world sperm activation and sperm factors active at fertilization and the mo­ lecular basis of specific pathologies of the testis the use of genetically manipulated animal models in the study of the regulation of spermatogenesis and of the en­ docrine role of the testis represents a core part of the present volume