Policies and Security Aspects For Distributed Scientific Laboratories

Abstract Web Services and the Grid allow distributed research teams to form dynamic, multi-institutional virtual organizations sharing high performance computing resources, large scale data sets and instruments for solving computationally intensive scientific applications, thereby forming Virtual Laboratories. This paper aims at exploring security issues of such distributed scientific laboratories and tries to extend security mechanisms by defining a general approach in which a security policy is used both to provide and regulate access to scientific services. In particular, we consider how security policies specified in XACML and WS-Policy can support the requirements of secure data and resource sharing in a scientific experiment. A framework is given where security policies are stated by the different participants in the experiment, providing a Policy Management system. A prototype implementation of the proposed framework is presented

Influence of dehydroepiandrosterone on G-6-PD activity and 3H-thymidine uptake of human lymphocytes in vitro

Dehydroepiandrosterone (DHEA) was found to inhibit experimental cancer development in mouse and rat lung, colon and mammary gland. Since DHEA is a potent inhibitor of mammalian G-6-PD, the hypothesis that the compound could inhibit cell proliferation through an inhibition of the pentose phosphate pathway has been formulated. We studied the effects of DHEA on the proliferation in vitro of human lymphocytes induced by several mitogens (PHA, ConA and PWM), measuring 3H-thymidine uptake. DHEA inhibited 3H-thymidine uptake of mitogen-stimulated cells from both G-6-PD+ and G-6-PD- (mediterranean type deficiency) individuals in a dose-dependent and reversible fashion. The inhibitory effect was found even if DHEA was added to cells in the last hours of culture, simultaneously with the addition of 3H-thymidine. These data suggest that the inhibition of thymidine uptake induced by DHEA on human lymphocytes probably does not depend on the inhibition of G-6-PD