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Infrastructureless networks are becoming more popular with the increased prevalence of wireless networking technology. A significant challenge faced by these infrastructureless networks is that of providing security. In this paper we examine the issue of authentication, a fundamental component of most security approaches, and show how it can be performed despite an absence of trusted infrastructure and limited or no existing trust relationship between network nodes. Our approach enables nodes to authenticate using a combination of contextual information, harvested from the environment, and traditional authentication factors (such as public key cryptography). Underlying our solution is a generic threshold signature scheme that enables distributed generation of digital certificates.
Comment: To appear in the proceedings of 34$^{\rm th}$ International Conference on High Energy Physics, Philadelphia, 2008
The development of high-level standard representations of buildings has been welcomed by the majority within the industry. Such standards allow for semantic interoperability between the large number of design tools which are available to practitioners in the A/E/C and FM industries. However, with such standards comes greater reliance on the information contained within the models which are transmitted, and interpreted, automatically between design tools. Unlike geometry-based standards (e.g., DXF, IGES, DWG, etc) where there was always an expectation of human interpretation, this semantic data must be correct to fit within the interoperable world we have developed. Testing of the semantic interoperability of a small number of commercial design tools has shown that this level of trust is not yet able to be assumed and that further work ...
Determinate growth of floral meristems in Arabidopsis requires the function of the floral regulatory gene AGAMOUS (AG). Expression of AG mRNA in the central region of floral meristems relies on the partially overlapping functions of the LEAFY (LFY) and APETALA1 (AP1) genes, which promote initial floral meristem identity. Here, we provide evidence that AG function is required for the final definition of floral meristem identity and that constitutive AG function can promote, independent of LFY and AP1 functions, the determinate floral state in the center of reproductive meristems. Loss-of-function analysis showed that the indeterminate central region of the ag mutant floral meristem undergoes conversion to an inflorescence meristem when long-day-dependent flowering stimulus is removed. Furthermore, gain-of-function analysis demonstrated ...
A novel gene that regulates floral meristem activity and controls floral organ number was identified in Arabidopsis and is designated FON1 (for FLORAL ORGAN NUMBER1). The fon1 mutants exhibit normal vegetative development and produce normal inflorescence meristems and immature flowers before stage 6. fon1 flowers become visibly different from wild-type flowers at stage 6, when the third-whorl stamen primordia have formed. The fon1 floral meristem functions longer than does that of the wild type: after the outer three-whorl organ primordia have initiated, the remaining central floral meristem continues to produce additional stamen primordia interior to the third whorl. Prolonged fon1 floral meristem activity also results in an increased number of carpels. The clavata (clv) mutations are known to affect floral meristem activity. We have ...
Comment: 7 pages, 3 figures
Comment: 32 pages, Chinese Physics (accepted)
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