Development of an adaptronic spindle for a faultless machining of homogeneous and inhomogeneous materials

One of the latest topics in construction concerns the difficulty of producing faultless drill holes in parts made of composite and sandwich materials. At the Institute for Machine Tools of the University of Stuttgart, a prototype of an adaptronic drilling spindle for a machining of components made of homogeneous and inhomogeneous materials was developed within the framework of a research project, funded by the Federal Ministry for Economic Affairs and Energy. The spindle made it possible to limit the axial force and the torque acting on the tool, thus protecting the tools and the workpieces from any possible damage. The tests carried out with the spindle prototype proved that the axial feed force acting from the spindle can be reliably controlled by means of the developed spindle. It might be possible to restrict critical machining situations arising due to the removal of drill chips or the reduction of process temperatures

Recipient Preparation and Mixed Germ Cell Isolation for Spermatogonial Stem Cell Transplantation in Domestic Cats

The loss of genetic diversity poses a serious threat to the conservation of endangered species, including wild felids. We are attempting to develop spermatogonial stem cell transplantation in the cat as a tool to preserve and propagate male germ-plasm from genetically valuable animals, be they threatened wild species or lines of cats used as models for inherited diseases. In this study, we investigated the use of local external beam radiation treatment to deplete the endogenous germ cells of male domestic cats, a step necessary to prepare them for use as recipients for transplantation. Testes of 5-month-old domestic cats were irradiated with a fractionated dose of 3 Gy per fraction for 3 consecutive days. These cats were castrated at 2, 4, 8, 16, and 32 weeks posttreatment, and progress of spermatogenesis was evaluated histologically and compared against age-matched controls. Even at the latest time points, less than 10% of tubules contained germ cells at any stage of meiosis, showing the efficacy of this protocol. In addition, male germ cells were isolated from the testes of domestic cats using a 2-step enzymatic dissociation to establish a protocol for the preparation of donor cells. The presence and viability of spermatogonia within this population were demonstrated by successful transplantation into, and colonization of, mouse seminiferous tubules. The success of these protocols provides a foundation to perform spermatogonial stem cell transplantation in the domestic cat.Supported in part by grants from the Morris Animal Foundation (A.J.T.), Cornell Universitys Feline Health Center (A.J.T.), and the BK21 Fellowship program between Seoul National University and Cornell University (Y.K.). We thank Professor Ralph Brinster of the University of Pennsylvania School of Veterinary Medicine for his support of the feline spermatogonial stem cell transplantation into the mouse, which was performed in his laboratory. We thank Colonial Veterinary Hospital, Ithaca, NY, and Dr Leslie D. Appel of Shelter Outreach Services for providing testis specimens from routine castrations. We also thank Drs Blaise P. Burke and Rodney L. Page for their assistance with the external beam radiation treatment, as well as Jean Spencer and Laura Hobbs for their technical assistance

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field