1,816 research outputs found

    Four Commentaries: How We Can Better Protect Children From Abuse and Neglect

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    The fundamental structure of the public child welfare system is that of a coercive apparatus wrapped in a helping orientation. Agencies ostensibly having the mission to help are mandated to ask whether parents can be blamed for their child welfare problems, and these agencies have the power to remove children from their homes. Thus, the public child welfare agency has a dual-role structure: On one hand, the agency attempts to engage in prevention and support, and to promote family preservation; on the other hand, it also has the task of investigating complaints against parents and removing children from them. This fact has had enormous consequences for the fate of child protection

    Review of \u3cem\u3eThe Future of Child Protection.\u3c/em\u3e Jane Waldfogel. Reviewed by Leroy H. Pelton, University of Nevada, Las Vegas.

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    Book review of Jane Waldfogel, The Future of Child Protection. Cambridge, MA: Harvard University Press, 1998. $39.95 hardcover

    Review of \u3cem\u3eReforming Child Welfare.\u3c/em\u3e Olivia Golden. Reviewed by Leroy H. Pelton.

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    Book review of Olivia Golden, Reforming Child Welfare. Washington, DC: The Urban Institute Press, 2009. $29.50 papercover

    Characterizing Quantum-Dot Blinking Using Noise Power Spectra

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    Fluctuations in the fluorescence from macroscopic ensembles of colloidal semiconductor quantum dots have the spectral form of 1/f noise. The measured power spectral density reflects the fluorescence intermittency of individual dots with power-law distributions of "on" and "off" times, and can thus serve as a simple method for characterizing such blinking behavior

    Use of ERTS-1 data in the educational and applied research programs of agricultural extension

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    There are no author-identified significant results in this report

    A calcium ion in a cavity as a controlled single-photon source

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    We present a single calcium ion, coupled to a high-finesse cavity, as an almost ideal system for the controlled generation of single photons. Photons from a pump beam are Raman-scattered by the ion into the cavity mode, which subsequently emits the photon into a well-defined output channel. In contrast with comparable atomic systems, the ion is localized at a fixed position in the cavity mode for indefinite times, enabling truly continuous operation of the device. We have performed numeric calculations to assess the performance of the system and present the first experimental indication of single-photon emission in our set-up

    Quantum key distribution over 30km of standard fiber using energy-time entangled photon pairs: a comparison of two chromatic dispersion reduction methods

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    We present a full implementation of a quantum key distribution system using energy-time entangled photon pairs and functioning with a 30km standard telecom fiber quantum channel. Two bases of two orthogonal states are implemented and the setup is quite robust to environmental constraints such as temperature variation. Two different ways to manage chromatic dispersion in the quantum channel are discussed.Comment: 10 pages, 4 figure

    Practical quantum repeaters with linear optics and double-photon guns

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    We show how to create practical, efficient, quantum repeaters, employing double-photon guns, for long-distance optical quantum communication. The guns create polarization-entangled photon pairs on demand. One such source might be a semiconducter quantum dot, which has the distinct advantage over parametric down-conversion that the probability of creating a photon pair is close to one, while the probability of creating multiple pairs vanishes. The swapping and purifying components are implemented by polarizing beam splitters and probabilistic optical CNOT gates.Comment: 4 pages, 4 figures ReVTe

    Response patterns in the developing social brain are organized by social and emotion features and disrupted in children diagnosed with autism spectrum disorder

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    © 2019 Elsevier Ltd Adults and children recruit a specific network of brain regions when engaged in “Theory of Mind” (ToM) reasoning. Recently, fMRI studies of adults have used multivariate analyses to provide a deeper characterization of responses in these regions. These analyses characterize representational distinctions within the social domain, rather than comparing responses across preferred (social) and non-preferred stimuli. Here, we conducted opportunistic multivariate analyses in two previously collected datasets (Experiment 1: n = 20 5–11 year old children and n = 37 adults; Experiment 2: n = 76 neurotypical and n = 29 5–12 year old children diagnosed with Autism Spectrum Disorder (ASD)) in order to characterize the structure of representations in the developing social brain, and in order to discover if this structure is disrupted in ASD. Children listened to stories that described characters' mental states (Mental), non-mentalistic social information (Social), and causal events in the environment (Physical), while undergoing fMRI. We measured the extent to which neural responses in ToM brain regions were organized according to two ToM-relevant models: 1) a condition model, which reflected the experimenter-generated condition labels, and 2) a data-driven emotion model, which organized stimuli according to their emotion content. We additionally constructed two control models based on linguistic and narrative features of the stories. In both experiments, the two ToM-relevant models outperformed the control models. The fit of the condition model increased with age in neurotypical children. Moreover, the fit of the condition model to neural response patterns was reduced in the RTPJ in children diagnosed with ASD. These results provide a first glimpse into the conceptual structure of information in ToM brain regions in childhood, and suggest that there are real, stable features that predict responses in these regions in children. Multivariate analyses are a promising approach for sensitively measuring conceptual and neural developmental change and individual differences in ToM.NSF (Award 1122374
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