Crosslinking of proteins by tissue transglutaminase (tTG) is enhanced in amyloid (Ab) deposits characteristic of Alzheimer's disease and sporadic inclusion body myositis. Small heat shock proteins (sHsps) also occur in amyloid deposits. We here report the substrate characteristics for tTG of six sHsps. Hsp27, Hsp20 and HspB8 are both lysine-and glutaminedonors, aB-crystallin only is a lysine-donor, HspB2 a glutaminedonor, and HspB3 no substrate at all. Close interaction of proteins stimulates crosslinking efficiency as crosslinking between different sHsps only takes place within the same heteromeric complex. We also observed that aB-crystallin, Hsp27 and Hsp20 associate with Ab in vitro, and can be readily crosslinked by tTG.

Abstract. Current intrusion detection systems have a narrow scope. They target flow aggregates, reconstructed TCP streams, individual packets or application-level data fields, but no existing solution is capable of handling all of the above. Moreover, most systems that perform payload inspection on entire TCP streams are unable to handle gigabit link rates. We argue that network-based intrusion detection systems should consider all levels of abstraction in communication (packets, streams, layer-7 data units, and aggregates) if they are to handle gigabit link rates in the face of complex application-level attacks such as those that use evasion techniques or polymorphism. For this purpose, we developed a framework for network-based intrusion prevention at the network edge that is able to cope with all levels of abstraction and can be easily extended with new techniques. We validate our approach by making available a practical system, SafeCard , capable of reconstructing and scanning TCP streams at gigabit rates while preventing polymorphic buffer-overflow attacks, using (up to) layer-7 checks. Such performance makes it applicable in-line as an intrusion prevention system. SafeCard merges multiple solutions, some new and some known. We made specific contributions in the implementation of deep-packet inspection at high speeds and in detecting and filtering polymorphic buffer overflows.

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Streamline is a stream-based OS communication subsystem that spans from peripheral hardware to userspace processes. It improves performance of I/O-bound applications (such as webservers and streaming media applications) by constructing tailor-made I/O paths through the operating system for each application at runtime. Path optimization removes unnecessary copying, context switching and cache replacement and integrates specialized hardware. Streamline automates optimization and only presents users a clear, concise job control language based on Unix pipelines. For backward compatibility Streamline also presents well known files, pipes and sockets abstractions. Observed throughput improvement over Linux 2.6.24 for networking applications is up to 30-fold, but two-fold is more typical.

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