1,816 research outputs found
Four Commentaries: How We Can Better Protect Children From Abuse and Neglect
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.
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.
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
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
There are no author-identified significant results in this report
A calcium ion in a cavity as a controlled single-photon source
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
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
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
© 2019 Elsevier Ltd Adults and children recruit a specific network of brain regions when engaged in âTheory of Mindâ (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 5â11 year old children and n = 37 adults; Experiment 2: n = 76 neurotypical and n = 29 5â12 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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