1,243,291 research outputs found
Instrumenting self-modifying code
Adding small code snippets at key points to existing code fragments is called
instrumentation. It is an established technique to debug certain otherwise hard
to solve faults, such as memory management issues and data races. Dynamic
instrumentation can already be used to analyse code which is loaded or even
generated at run time.With the advent of environments such as the Java Virtual
Machine with optimizing Just-In-Time compilers, a new obstacle arises:
self-modifying code. In order to instrument this kind of code correctly, one
must be able to detect modifications and adapt the instrumentation code
accordingly, preferably without incurring a high penalty speedwise. In this
paper we propose an innovative technique that uses the hardware page protection
mechanism of modern processors to detect such modifications. We also show how
an instrumentor can adapt the instrumented version depending on the kind of
modificiations as well as an experimental evaluation of said techniques.Comment: In M. Ronsse, K. De Bosschere (eds), proceedings of the Fifth
International Workshop on Automated Debugging (AADEBUG 2003), September 2003,
Ghent. cs.SE/030902
Ethics of modifying the mitochondrial genome
Recent preclinical studies have shown the feasibility of specific variants of nuclear transfer to prevent mitochondrial DNA disorders. Nuclear transfer could be a valuable reproductive option for carriers of mitochondrial mutations. A clinical application of nuclear transfer, however, would entail germ-line modification, more specifically a germ-line modification of the mitochondrial genome. One of the most prominent objections against germ-line modification is the fear that it would become possible to alter 'essential characteristics' of a future person, thereby possibly violating the child's right to an open future. As only the nuclear DNA would contain the ingredients for individual characteristics, modification of the mtDNA is often considered less controversial than modification of the nuclear DNA. This paper discusses the tenability of this dichotomy. After having clarified the concept of germ-line modification, it argues that modification of the mtDNA is not substantively different from modification of the nuclear DNA in terms of its effects on the identity of the future person. Subsequently the paper assesses how this conclusion affects the moral evaluation of nuclear transfer to prevent mtDNA disorders. It concludes that the moral acceptability of germ-line modification does not depend on whether it alters the identity of the future child-all germ-line modifications do-but on whether it safeguards the child's right to an open future. If nuclear transfer to prevent mtDNA disorders becomes safe and effective, then dismissing it because it involves germ-line modification is unjustified
Solar cell including second surface mirrors Patent
Modifying existing solar cells for temperature contro
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