10,177 research outputs found
Improving Reading Skills by Encouraging Children to Read: A Randomized Evaluation of the Sa Aklat Sisikat Reading Program in the Philippines
We evaluate a program that aims to improve children's reading skills by providing classes with age-appropriate reading material and incentivizing children to read through a 31 day read-a-thon. During the read-a-thon, the program significantly increases the propensity of children to read, causing 20 percent more children to have read a book in the last week at school and increasing the number of books read by 2.3 in the last week and 7.2 in the last month. These increases extend both after the end of the program and outside of school, although at lower rates. The program also increased students’ scores on a reading assessment, causing students’ scores to improve by 0.13 standard deviations immediately after the program. The effect persisted even after the program ended with an effect of 0.06 standard deviations three months later.education, reading, development
Testing the Impact of Higher Achievement's Year-Round Out-of-School-Time Program on Academic Outcomes
Presents findings from a multiyear evaluation of an intensive long-term OST program's effect on low-income middle school students' academic performance, attitudes, and behaviors. Outlines implications for financially strapped districts
Quasi-Particle Degrees of Freedom versus the Perfect Fluid as Descriptors of the Quark-Gluon Plasma
The hot nuclear matter created at the Relativistic Heavy Ion Collider (RHIC)
has been characterized by near-perfect fluid behavior. We demonstrate that this
stands in contradiction to the identification of QCD quasi-particles with the
thermodynamic degrees of freedom in the early (fluid) stage of heavy ion
collisions. The empirical observation of constituent quark ``'' scaling of
elliptic flow is juxtaposed with the lack of such scaling behavior in
hydrodynamic fluid calculations followed by Cooper-Frye freeze-out to hadrons.
A ``quasi-particle transport'' time stage after viscous effects break down the
hydrodynamic fluid stage, but prior to hadronization, is proposed to reconcile
these apparent contradictions. However, without a detailed understanding of the
transitions between these stages, the ``'' scaling is not a necessary
consequence of this prescription. Also, if the duration of this stage is too
short, it may not support well defined quasi-particles. By comparing and
contrasting the coalescence of quarks into hadrons with the similar process of
producing light nuclei from nucleons, it is shown that the observation of
``'' scaling in the final state does not necessarily imply that the
constituent degrees of freedom were the relevant ones in the initial state.Comment: 9 pages, 7 figures, Updated text and figure
Summer Snapshot: Exploring the Impact of Higher Achievement's Year-Round Out-of-School-Time Program on Summer Learning
Assesses the impact of a multiyear, intensive, academically focused OST program for motivated but underserved middle school students on test scores, summer program participation, and summer learning loss. Examines contributing factors and implications
Functional imaging reveals working memory and attention interact to produce the attentional blink
Copyright @ 2012 Massachusetts Institute of Technology PressIf two centrally presented visual stimuli occur within approximately half a second of each other, the second target often fails to be reported correctly. This effect, called the attentional blink (AB; Raymond, J. E., Shapiro, K. L., & Arnell, K. M. Temporary suppression of visual processing in an RSVP task: An attentional blink? Journal of Experimental Psychology, Human Perception and Performance, 18, 849-860, 1992], has been attributed to a resource "bottleneck," likely arising as a failure of attention during encoding into or retrieval from visual working memory (WM). Here we present participants with a hybrid WM-AB study while they undergo fMRI to provide insight into the neural underpinnings of this bottleneck. Consistent with a WM-based bottleneck account, fronto-parietal brain areas exhibited a WM load-dependent modulation of neural responses during the AB task. These results are consistent with the view that WM and attention share a capacity-limited resource and provide insight into the neural structures that underlie resource allocation in tasks requiring joint use of WM and attention.This research was supported by a project grant (071944) from the Wellcome Trust to Kimron Shapiro
Reconstruction of the phase of matter-wave fields using a momentum resolved cross-correlation technique
We investigate the potential of the so-called XFROG cross-correlation
technique originally developed for ultrashort laser pulses for the recovery of
the amplitude and phase of the condensate wave function of a Bose-Einstein
condensate. Key features of the XFROG method are its high resolution,
versatility and stability against noise and some sources of systematic errors.
After showing how an analogue of XFROG can be realized for Bose-Einstein
condensates, we illustrate its effectiveness in determining the amplitude and
phase of the wave function of a vortex state. The impact of a reduction of the
number of measurements and of typical sources of noise on the field
reconstruction are also analyzed.Comment: 7 pages; 9 figures; article with higher resolution figures available
from author
Designs of magnetic atom-trap lattices for quantum simulation experiments
We have designed and realized magnetic trapping geometries for ultracold
atoms based on permanent magnetic films. Magnetic chip based experiments give a
high level of control over trap barriers and geometric boundaries in a compact
experimental setup. These structures can be used to study quantum spin physics
in a wide range of energies and length scales. By introducing defects into a
triangular lattice, kagome and hexagonal lattice structures can be created.
Rectangular lattices and (quasi-)one-dimensional structures such as ladders and
diamond chain trapping potentials have also been created. Quantum spin models
can be studied in all these geometries with Rydberg atoms, which allow for
controlled interactions over several micrometers. We also present some
nonperiodic geometries where the length scales of the traps are varied over a
wide range. These tapered structures offer another way to transport large
numbers of atoms adiabatically into subwavelength traps and back.Comment: 9 pages, 10 figure
Optimal Entanglement Generation from Quantum Operations
We consider how much entanglement can be produced by a non-local two-qubit
unitary operation, - the entangling capacity of . For a single
application of , with no ancillas, we find the entangling capacity and
show that it generally helps to act with on an entangled state.
Allowing ancillas, we present numerical results from which we can conclude,
quite generally, that allowing initial entanglement typically increases the
optimal capacity in this case as well. Next, we show that allowing collective
processing does not increase the entangling capacity if initial entanglement is
allowed.Comment: v1.0 15 pages, 3 figures, written in revtex4. v2.0 References
updated. Submitted to Phys. Rev. A v3.0 16 pages, 4 figures. Expanded
explanation in section 3A, figures corrected and made clearer. Definition of
entangling capacity in section 4 made explicit. Other minor typos correcte
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