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Fighting global security threats with only a local view is inherently difficult. Internet network operators need to fight global phenomena such as botnets, but they are hampered by the fact that operators can observe only the traffic in their local domains. We propose a <i>collaborative</i> approach to this problem, in which operators share aggregate(More)
A lens is a bidirectional transformation between a pair of connected data structures, capable of translating an edit on one structure into an appropriate edit on the other. Many varieties of lenses have been studied, but none, to date, has offered a satisfactory treatment of how edits are represented. Many foundational accounts only consider edits of the(More)
The complex anatomy of the sacrum makes surgical fracture fixation challenging. We developed statistical models to investigate sacral anatomy with special regard to trans-sacral implant fixation. We used computed tomographies of 20 intact adult pelves to establish 3D statistical models: a surface model of the sacrum and the trans-sacral corridor S1,(More)
Fragility fractures of the pelvic ring (FFP) are increasing in frequency and require challenging treatment. A new comprehensive classification considers both fracture morphology and degree of instability. The classification system also provides recommendations for type and invasiveness of treatment. In this article, a literature review of treatment(More)
We explore a new class of process calculi, collectively called spider calculi, in which processes inhabit the nodes of a directed graph, evolving and communicating by local structural mutations. We study a variety of spider calculi, analyze their expressive power, and identify a kernel spider calculus that is both minimal and expressive. In particular,(More)
Trans-sacral implants can be used alternatively to sacro-iliac screws in the treatment of osteoporosis-associated fragility fractures of the pelvis and the sacrum. We investigated trans-sacral corridor dimensions, the number of individuals amenable to trans-sacral fixation, as well as the osseous boundaries and shape of the S1 corridor. 3D models were(More)
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