Recent changes in kinship care policy produce a range of care-types for grandparents raising their grandchildren, from informal kinship care to adoption. The unprecedented formalization of kinship care, expedited termination of parental rights, and conflict between parents and grandparents over the best interests of children require custodial grandparents to make determinations about care-type, termed "institutional decision making." Interview data collected from 50 black custodial grandmothers from Chicago are used to reveal how and why parental responses help explain variation in care-types. This article argues that institutional decisions enable custodial grandmothers to achieve family stability by offering them an opportunity to be a safety net of protection to grandchildren, to respond to a range of parental responses that emerge as they work to eradicate child welfare threats, and to navigate institutions. The present study shows that, as parental responses increase in uncertainty and noncompliance, care-types become more formalized.

Knill, Laflamme, and Milburn recently showed that non-deterministic quantum logic operations could be performed using linear optical elements, additional photons (ancilla), and post-selection based on the output of single-photon detectors [Nature 409, 46 (2001)]. Here we report the experimental demonstration of two logic devices of this kind, a destructive controlled-NOT (CNOT) gate and a quantum parity check. These two devices can be combined with a pair of entangled photons to implement a conventional (non-destructive) CNOT that succeeds with a probability of 1 4 .

Abstract-In trading card games (TCGs), players create a deck of cards from a subset of all cards in the game to compete with other players. Each card in the deck has some feature or ability that may be used strategically to help a player defeat her opponent. Recently, trading card games have been moving from physical cards to digital, online versions. We propose a cheat-proof peer-to-peer protocol for implementing online trading card games. We break down actions common to all TCGs and explain how they can be executed between two players without the need for a third party referee (which usually requires an unbiased server). In each action, the player is either prevented from cheating or if they do cheat, the opponent will be able to prove they have done so. We conclude by showing how these methods are secure and how they may be intermixed for other styles of TCGs and other peer-to-peer games.

Most experimental demonstrations of entanglement require nonclassical states and correlated measurements of single-photon detection events. It is shown here that entanglement can produce a large decrease in the rate of two-photon absorption for a classical input state that can be observed using classical detectors. These effects can be interpreted as being due to the creation of entangled photon holes that are somewhat analogous to the holes of semiconductor theory.Entanglement is one of the most fundamental properties of quantum systems and it plays a major role in quantum information processing, for example. Here we show that a classical input state incident on a threelevel atomic medium will undergo two-photon absorption [1][2][3][4][5][6][7][8][9][10][11][12][13] at a rate that is greatly reduced by the generation of entangled photon holes that are somewhat analogous to the holes of semiconductor theory. The effects of entanglement can then be observed using a classical detector, such as an intensity meter. The entangled photon holes can also violate Bell's inequality if single-photon detectors are used.Many nonclassical features of two-photon absorption have already been described [3][4][5][6][7][8][9][10][11][12], including an enhanced rate of two-photon absorption when the incident photons are entangled [3,[8][9]12]. The pairs of photons from parametric down-conversion are known to have been emitted at nearly the same time, but that time is completely uncertain in the quantummechanical sense, as illustrated in Fig. 1a [14]. The fact that the photons are incident on any given atom at the same time while their total energy is still well defined gives rise to an increase in the rate of two-photon absorption, which can be linearly dependent on the intensity of the incident beam [8][9]12].The situation of interest here is essentially the inverse of parametric down-conversion, as illustrated in Fig 1b. In the limit of large detunings, three-level atoms will absorb pairs of photons at very nearly the same time, producing a decrease in the probability amplitude for both of the photons to be at the same location. In analogy with the holes of semiconductor theory, the reduced probability amplitudes of Fig. 1b can be viewed as entangled photon holes in an otherwise constant background. Entanglement of this kind can reduce the rate of two-photon absorption to a level that is substantially less than that of classical or semiclassical theory. Roughly speaking, the magnitude of the dips in the probability amplitude will continue to increase until there is no significant probability amplitude for two photons to be found at the same location.The state vectors corresponding to the probability amplitudes of Figs 1a and 1b cannot be written as the product of two single-particle states and both systems are thus in an entangled state. One way to demonstrate the entanglement is by showing that Bell's inequality can be violated, as will be done later in the paper after we first consider the macroscopic effects of the entangled ph...

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