5,336 research outputs found
English Literacy Development for English Language Learners: Does Spanish Instruction Promote or Hinder?
In this brief, the authors consider whether instruction in a child\u27s native language (particularly Spanish) hinders or promotes learning of literacy in English. The authors conduct a four-step process for identifying research on this topic, examining this literature, and then determining the answer to this clinical question. The results suggest that supporting a child\u27s home/native language promotes rather than hinders development of English literacy skills
Relaxation dynamics of the toric code in contact with a thermal reservoir: Finite-size scaling in a low temperature regime
We present an analysis of the relaxation dynamics of finite-size topological
qubits in contact with a thermal bath. Using a continuous-time Monte Carlo
method, we explicitly compute the low-temperature nonequilibrium dynamics of
the toric code on finite lattices. In contrast to the size-independent bound
predicted for the toric code in the thermodynamic limit, we identify a
low-temperature regime on finite lattices below a size-dependent crossover
temperature with nontrivial finite-size and temperature scaling of the
relaxation time. We demonstrate how this nontrivial finite-size scaling is
governed by the scaling of topologically nontrivial two-dimensional classical
random walks. The transition out of this low-temperature regime defines a
dynamical finite-size crossover temperature that scales inversely with the log
of the system size, in agreement with a crossover temperature defined from
equilibrium properties. We find that both the finite-size and
finite-temperature scaling are stronger in the low-temperature regime than
above the crossover temperature. Since this finite-temperature scaling competes
with the scaling of the robustness to unitary perturbations, this analysis may
elucidate the scaling of memory lifetimes of possible physical realizations of
topological qubits.Comment: 14 Pages, 13 figure
Assessing the Impact of Interactive Technology on Aircraft Rescue and Fire Fighting Training
The presentation will discuss the current research being conducted by the Embry-Riddle Aeronautical University-Worldwide’s Fire Science department concerning use of technology-advanced educational software at the Dallas/Fort Worth (DFW) Fire Training Research Center (FTRC). The research design is mixed methods, using quantitative data analysis to evaluate student survey results, integrated with qualitative observation and participation data, to create a sequential exploratory research strategy.DFW FTRC means to combine the latest scientific fire research and hands-on training with technology-advanced educational software. It is used as part of the aircraft rescue and fire fighting (ARFF) educational curriculum to familiarize students with the unique features of various aircraft and airports; thus, students can visualize actual disaster scenarios at specific airports with certain aircraft. This study explores the extent to which the interactive learning technology creates a better learning experience for students and how it may translate to more effective ARFF response scenarios
Benchmarking high fidelity single-shot readout of semiconductor qubits
Determination of qubit initialisation and measurement fidelity is important
for the overall performance of a quantum computer. However, the method by which
it is calculated in semiconductor qubits varies between experiments. In this
paper we present a full theoretical analysis of electronic single-shot readout
and describe critical parameters to achieve high fidelity readout. In
particular, we derive a model for energy selective state readout based on a
charge detector response and examine how to optimise the fidelity by choosing
correct experimental parameters. Although we focus on single electron spin
readout, the theory presented can be applied to other electronic readout
techniques in semiconductors that use a reservoir.Comment: 19 pages, 8 figure
Combined molecular dynamics and quantum trajectories simulation of laser-driven, collisional systems
We introduce a combined molecular dynamics (MD) and quantum trajectories (QT)
code to simulate the effects of near-resonant optical fields on state-vector
evolution and particle motion in a collisional system. In contrast to
collisionless systems, in which the quantum dynamics of multi-level,
laser-driven particles with spontaneous emission can be described with the
optical Bloch equations (OBEs), particle velocities in sufficiently collisional
systems change on timescales comparable to those of the laser-induced,
quantum-state dynamics. These transient velocity changes can cause the
time-averaged velocity dependence of the quantum state to differ from the OBE
solution. We use this multiscale code to describe laser-cooling in a strontium
ultracold neutral plasma. Important phenomena described by the simulation
include suppression of electromagnetically induced transparencies through rapid
velocity changing collisions and thermalization between cooled and un-cooled
directions for anisotropic laser cooling.Comment: 14 pages, 10 figure
Scenarios of domain pattern formation in a reaction-diffusion system
We performed an extensive numerical study of a two-dimensional
reaction-diffusion system of the activator-inhibitor type in which domain
patterns can form. We showed that both multidomain and labyrinthine patterns
may form spontaneously as a result of Turing instability. In the stable
homogeneous system with the fast inhibitor one can excite both localized and
extended patterns by applying a localized stimulus. Depending on the parameters
and the excitation level of the system stripes, spots, wriggled stripes, or
labyrinthine patterns form. The labyrinthine patterns may be both connected and
disconnected. In the the stable homogeneous system with the slow inhibitor one
can excite self-replicating spots, breathing patterns, autowaves and
turbulence. The parameter regions in which different types of patterns are
realized are explained on the basis of the asymptotic theory of instabilities
for patterns with sharp interfaces developed by us in Phys. Rev. E. 53, 3101
(1996). The dynamics of the patterns observed in our simulations is very
similar to that of the patterns forming in the ferrocyanide-iodate-sulfite
reaction.Comment: 15 pages (REVTeX), 15 figures (postscript and gif), submitted to
Phys. Rev.
RKKY interaction between adsorbed magnetic impurities in graphene: Symmetry and strain effects
The growing interest in carbon-based spintronics has stimulated a number of
recent theoretical studies on the RKKY interaction in graphene, with the aim of
determining the most energetically favourable alignments between embedded
magnetic moments. The RKKY interaction in undoped graphene decays faster than
expected for conventional two-dimensional materials and recent studies suggest
that the adsorption configurations favoured by many transition-metal impurities
may lead to even shorter ranged decays and possible sign-changing oscillations.
Here we show that these features emerge in a mathematically transparent manner
when the symmetry of the configurations is included in the calculation.
Furthermore, we show that by breaking the symmetry of the graphene lattice, via
uniaxial strain, the decay rate, and hence the range, of the RKKY interaction
can be significantly altered. Our results suggest that magnetic interactions
between adsorbed impurities in graphene can be manipulated by careful strain
engineering of such systems.Comment: 12 pages, 6 figures, submitte
Aboriginal Rules: The Black History of Australian Football
This paper is interested in the significance of Australian football to the Aboriginal and Torres Strait Islander people of Australia. In particular, this paper is interested in the cultural power of football and how it has foregrounded the struggle and highlighted the contribution that Indigenous people have made to the national football code of Australia. This paper also discusses key moments in Indigenous football history in Australia. It questions further that a greater understanding of this contribution needs to be more fully explored from a national perspective in order to appreciate Indigenous peoples' contribution to the sport not just in elite competitions but also at a community and grass roots level
Shifts in Species Interactions Due to the Evolution of Functional Differences between Endemics and Non-Endemics: An Endemic Syndrome Hypothesis
Species ranges have been shifting since the Pleistocene, whereby fragmentation, isolation, and the subsequent reduction in gene flow have resulted in local adaptation of novel genotypes and the repeated evolution of endemic species. While there is a wide body of literature focused on understanding endemic species, very few studies empirically test whether or not the evolution of endemics results in unique function or ecological differences relative to their widespread congeners; in particular while controlling for environmental variation. Using a common garden composed of 15 Eucalyptus species within the subgenus Symphyomyrtus (9 endemic to Tasmania, 6 non-endemic), here we hypothesize and show that endemic species are functionally and ecologically different from non-endemics. Compared to non-endemics, endemic Eucalyptus species have a unique suite of functional plant traits that have extended effects on herbivores. We found that while endemics occupy many diverse habitats, they share similar functional traits potentially resulting in an endemic syndrome of traits. This study provides one of the first empirical datasets analyzing the functional differences between endemics and non-endemics in a common garden setting, and establishes a foundation for additional studies of endemic/non-endemic dynamics that will be essential for understanding global biodiversity in the midst of rapid species extinctions and range shifts as a consequence of global change
Rituximab monitoring and redosing in pediatric neuromyelitis optica spectrum disorder.
Abstract
OBJECTIVE:
To study rituximab in pediatric neuromyelitis optica (NMO)/NMO spectrum disorders (NMOSD) and the relationship between rituximab, B cell repopulation, and relapses in order to improve rituximab monitoring and redosing.
METHODS:
Multicenter retrospective study of 16 children with NMO/NMOSD receiving 652 rituximab courses. According to CD19 counts, events during rituximab were categorized as "repopulation," "depletion," or "depletion failure" relapses (repopulation threshold CD19 6510
7 10(6) cells/L).
RESULTS:
The 16 patients (14 girls; mean age 9.6 years, range 1.8-15.3) had a mean of 6.1 events (range 1-11) during a mean follow-up of 6.1 years (range 1.6-13.6) and received a total of 76 rituximab courses (mean 4.7, range 2-9) in 42.6-year cohort treatment. Before rituximab, 62.5% had received azathioprine, mycophenolate mofetil, or cyclophosphamide. Mean time from rituximab to last documented B cell depletion and first repopulation was 4.5 and 6.8 months, respectively, with large interpatient variability. Earliest repopulations occurred with the lowest doses. Significant reduction between pre- and post-rituximab annualized relapse rate (ARR) was observed (p = 0.003). During rituximab, 6 patients were relapse-free, although 21 relapses occurred in 10 patients, including 13 "repopulation," 3 "depletion," and 4 "depletion failure" relapses. Of the 13 "repopulation" relapses, 4 had CD19 10-50
7 10(6) cells/L, 10 had inadequate monitoring ( 641 CD19 in the 4 months before relapses), and 5 had delayed redosing after repopulation detection.
CONCLUSION:
Rituximab is effective in relapse prevention, but B cell repopulation creates a risk of relapse. Redosing before B cell repopulation could reduce the relapse risk further.
CLASSIFICATION OF EVIDENCE:
This study provides Class IV evidence that rituximab significantly reduces ARR in pediatric NMO/NMOSD. This study also demonstrates a relationship between B cell repopulation and relapses
- …