3,128 research outputs found
Lessons from Maine: Education Vouchers for Students since 1873
Since 1873 Maine has financed the education of thousands of kindergarten through 12th grade students in private schools. In fact, the state pays tuition for 35 percent of all students enrolled in Maine's private schools. The tuition program enables parents in towns without a traditional public school to choose a school from a list of approved private and public schools, enroll their child, and have the town pay that child's tuition up to an authorized amount. The town then receives full or partial reimbursement from the state. In the fall of 1999, 5,614 students from 55 different communities attended private schools through this program, while 30,412 attended nearby public schools. Schools of choice ranged from regular public schools to local academies such as Waynflete School in Portland, Maine, to boarding schools ranging from Choate and Phillips Exeter in New England to Vail Valley Academy in Colorado. Data from the Maine Department of Education suggest that the tuition program costs roughly $6,000 per student, or 20 percent less than Maine's average per pupil expenditure for public education. Time and time again citizens have voted to keep this system that has been described as "the most valued attribute" of living in Maine. It's unfortunate that one of the best features of Maine's educational system is limited to students who live in the "right" towns. Maine's policymakers should seek to facilitate greater educational opportunities for all students, and policymakers nationwide should look to Maine's extensive experience with vouchers to inform their education reform efforts
The Work Ethic
[Excerpt] In everyday usage of the term \u27Work Ethic\u27 is almost indistinguishable from work satisfaction or simply attitudes to work. Do people value work or not, or are they in various degrees indifferent to it? Since most adults are expected to work and most do in order to make a living, the work ethic in this popular use of the term is, on average, positive for most people. Nevertheless there are bound to be variations in this average and in the distribution around the average for different groups of people
Characterizing time-irreversibility in disordered fermionic systems by the effect of local perturbations
We study the effects of local perturbations on the dynamics of disordered
fermionic systems in order to characterize time-irreversibility. We focus on
three different systems, the non-interacting Anderson and Aubry-Andr\'e-Harper
(AAH-) models, and the interacting spinless disordered t-V chain. First, we
consider the effect on the full many-body wave-functions by measuring the
Loschmidt echo (LE). We show that in the extended/ergodic phase the LE decays
exponentially fast with time, while in the localized phase the decay is
algebraic. We demonstrate that the exponent of the decay of the LE in the
localized phase diverges proportionally to the single-particle localization
length as we approach the metal-insulator transition in the AAH model. Second,
we probe different phases of disordered systems by studying the time
expectation value of local observables evolved with two Hamiltonians that
differ by a spatially local perturbation. Remarkably, we find that many-body
localized systems could lose memory of the initial state in the long-time
limit, in contrast to the non-interacting localized phase where some memory is
always preserved
Inflationary dynamics for matrix eigenvalue problems
Many fields of science and engineering require finding eigenvalues and
eigenvectors of large matrices. The solutions can represent oscillatory modes
of a bridge, a violin, the disposition of electrons around an atom or molecule,
the acoustic modes of a concert hall, or hundreds of other physical quantities.
Often only the few eigenpairs with the lowest or highest frequency (extremal
solutions) are needed. Methods that have been developed over the past 60 years
to solve such problems include the Lanczos [1,2] algorithm, Jacobi-Davidson
techniques [3], and the conjugate gradient method [4]. Here we present a way to
solve the extremal eigenvalue/eigenvector problem, turning it into a nonlinear
classical mechanical system with a modified Lagrangian constraint. The
constraint induces exponential inflationary growth of the desired extremal
solutions.Comment: 6 pages, 3 figure
Unconventional Wisdom: Estimating the Economic Impact of the Democratic and Republican National Political Conventions
We use daily hotel occupancy, price, and revenue data to analyze the economic impact of the 2008 and 2012 Democratic and Republican National Conventions. We find that political conventions generate approximately 29,000 room nights of lodging, though this figure is offset by lower hotel occupancy during the week before and, to a lesser extent, after conventions. Conventions increase hotel revenue by approximately 150 million or more may be implausible
Auditory feedback control mechanisms do not contribute to cortical hyperactivity within the voice production network in adductor spasmodic dysphonia
Adductor spasmodic dysphonia (ADSD), the most common form of spasmodic dysphonia, is a debilitating voice disorder characterized by hyperactivity and muscle spasms in the vocal folds during speech. Prior neuroimaging studies have noted excessive brain activity during speech in ADSD participants compared to controls. Speech involves an auditory feedback control mechanism that generates motor commands aimed at eliminating disparities between desired and actual auditory signals. Thus, excessive neural activity in ADSD during speech may reflect, at least in part, increased engagement of the auditory feedback control mechanism as it attempts to correct vocal production errors detected through audition. To test this possibility, functional magnetic resonance imaging was used to identify differences between ADSD participants and age-matched controls in (i) brain activity when producing speech under different auditory feedback conditions, and (ii) resting state functional connectivity within the cortical network responsible for vocalization. The ADSD group had significantly higher activity than the control group during speech (compared to a silent baseline task) in three left-hemisphere cortical regions: ventral Rolandic (sensorimotor) cortex, anterior planum temporale, and posterior superior temporal gyrus/planum temporale. This was true for speech while auditory feedback was masked with noise as well as for speech with normal auditory feedback, indicating that the excess activity was not the result of auditory feedback control mechanisms attempting to correct for perceived voicing errors in ADSD. Furthermore, the ADSD group had significantly higher resting state functional connectivity between sensorimotor and auditory cortical regions within the left hemisphere as well as between the left and right hemispheres, consistent with the view that excessive motor activity frequently co-occurs with increased auditory cortical activity in individuals with ADSD.First author draf
Efficient Cross-Domain Federated Learning by MixStyle Approximation
With the advent of interconnected and sensor-equipped edge devices, Federated
Learning (FL) has gained significant attention, enabling decentralized learning
while maintaining data privacy. However, FL faces two challenges in real-world
tasks: expensive data labeling and domain shift between source and target
samples. In this paper, we introduce a privacy-preserving, resource-efficient
FL concept for client adaptation in hardware-constrained environments. Our
approach includes server model pre-training on source data and subsequent
fine-tuning on target data via low-end clients. The local client adaptation
process is streamlined by probabilistic mixing of instance-level feature
statistics approximated from source and target domain data. The adapted
parameters are transferred back to the central server and globally aggregated.
Preliminary results indicate that our method reduces computational and
transmission costs while maintaining competitive performance on downstream
tasks.Comment: Accepted at the Adapting to Change: Reliable Multimodal Learning
Across Domains Workshop @ ECML PKKD 202
Oxazolone Colitis, a Th2 Colitis Model Resembling Ulcerative Colitis, Is Mediated by IL-13-Producing NK-T Cells
AbstractOxazolone colitis (OC) is an experimental colitis that has a histologic resemblance to human ulcerative colitis. Here we show that IL-13 production is a significant pathologic factor in OC since its neutralization by IL-13Rα2-Fc administration prevents colitis. We further show that OC is mediated by NK-T cells since it can be induced neither in mice depleted of NK-T cells nor in mice that cannot present antigen to NK-T cells and mice lacking an NK-T cell-associated TCR. Finally, we show that NK-T cells are the source of the IL-13, since they produce IL-13 upon stimulation by α-galactosylceramide, an NK-T cell-specific antigen. These data thus describe a cellular mechanism underlying an experimental colitis that may explain the pathogenesis of ulcerative colitis
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