Dithiolopyrrolone Natural Products : Isolation, Synthesis and Biosynthesis

Peer reviewedPublisher PD

A new species of the genus Celosia Winnertz from Tibet, China (Diptera: Mycetophilidae)

A new species of the genus Coelosia Winnertz, 1863 from Tibet, China is described, figured and discussed. Coelosia tibetensis Cao & Huang, sp. n. is the second Coelosia species from China. Two ocelli, clear brown shadings on the wing and the shape of the gonostylus are good characters to separate it from Coelosia tenella, the other Coelosia species found in China

Private Matchings and Allocations

We consider a private variant of the classical allocation problem: given k goods and n agents with individual, private valuation functions over bundles of goods, how can we partition the goods amongst the agents to maximize social welfare? An important special case is when each agent desires at most one good, and specifies her (private) value for each good: in this case, the problem is exactly the maximum-weight matching problem in a bipartite graph. Private matching and allocation problems have not been considered in the differential privacy literature, and for good reason: they are plainly impossible to solve under differential privacy. Informally, the allocation must match agents to their preferred goods in order to maximize social welfare, but this preference is exactly what agents wish to hide. Therefore, we consider the problem under the relaxed constraint of joint differential privacy: for any agent i, no coalition of agents excluding i should be able to learn about the valuation function of agent i. In this setting, the full allocation is no longer published---instead, each agent is told what good to get. We first show that with a small number of identical copies of each good, it is possible to efficiently and accurately solve the maximum weight matching problem while guaranteeing joint differential privacy. We then consider the more general allocation problem, when bidder valuations satisfy the gross substitutes condition. Finally, we prove that the allocation problem cannot be solved to non-trivial accuracy under joint differential privacy without requiring multiple copies of each type of good.Comment: Journal version published in SIAM Journal on Computation; an extended abstract appeared in STOC 201