4,876 research outputs found
Nonword Repetition and Interactions Among Vocabulary, Phonotactic probability, and Phonological Awareness in Four Linguistic Groups
The current study was designed to compare the English nonword repetition accuracy in 7-year-old monolingual English, Korean–English bilingual, Chinese–English bilingual, and Spanish–English bilingual children. The relationships among nonword repetition accuracy, vocabulary, phonological awareness, and phonotactic probability in each group of children were also examined. The results indicated significant differences among the groups’ accuracy of consonants and vowels by syllable length. Different correlational patterns emerged among nonword repetition accuracy, vocabulary, and phonological awareness. Theoretical and clinical implications for the use of nonword repetition tasks for children from various linguistic backgrounds are discussed
A functional analysis of two transdiagnostic, emotion-focused interventions on nonsuicidal self-injury
OBJECTIVE: Nonsuicidal self-injury (NSSI) is prevalent and associated with clinically significant consequences. Developing time-efficient and cost-effective interventions for NSSI has proven difficult given that the critical components for NSSI treatment remain largely unknown. The aim of this study was to examine the specific effects of mindful emotion awareness training and cognitive reappraisal, 2 transdiagnostic treatment strategies that purportedly address the functional processes thought to maintain self-injurious behavior, on NSSI urges and acts.
METHOD: Using a counterbalanced, combined series (multiple baseline and data-driven phase change) aggregated single-case experimental design, the unique and combined impact of these 2 4-week interventions was evaluated among 10 diagnostically heterogeneous self-injuring adults. Ecological momentary assessment was used to provide daily ratings of NSSI urges and acts during all study phases.
RESULTS: Eight of 10 participants demonstrated clinically meaningful reductions in NSSI; 6 participants responded to 1 intervention alone, whereas 2 participants responded after the addition of the alternative intervention. Group analyses indicated statistically significant overall effects of study phase on NSSI, with fewer NSSI urges and acts occurring after the interventions were introduced. The interventions were also associated with moderate to large reductions in self-reported levels of anxiety and depression, and large improvements in mindful emotion awareness and cognitive reappraisal skills.
CONCLUSIONS: Findings suggest that brief mindful emotion awareness and cognitive reappraisal interventions can lead to reductions in NSSI urges and acts. Transdiagnostic, emotion-focused therapeutic strategies delivered in time-limited formats may serve as practical yet powerful treatment approaches, especially for lower-risk self-injuring individuals.Dr. Barlow receives royalties from Oxford University Press, Guilford Publications Inc., Cengage Learning, and Pearson Publishing. Grant monies for various projects come from the National Institute of Mental Health (F31MH100761), the National Institute of Alcohol and Alcohol Abuse, and Colciencias (Government of Columbia Initiative for Science, Technology, and Health Innovation). Consulting and honoraria during the past several years have come from the Agency for Healthcare Research and Quality, the Foundation for Informed Medical Decision Making, the Department of Defense, the Renfrew Center, the Chinese University of Hong Kong, Universidad Catolica de Santa Maria (Arequipa, Peru), New Zealand Psychological Association, Hebrew University of Jerusalem, Mayo Clinic, and various American Universities. (F31MH100761 - National Institute of Mental Health; National Institute of Alcohol and Alcohol Abuse; Colciencias (Government of Columbia Initiative for Science, Technology, and Health Innovation))Accepted manuscrip
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
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
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.
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
Low Cost and Compact Quantum Cryptography
We present the design of a novel free-space quantum cryptography system,
complete with purpose-built software, that can operate in daylight conditions.
The transmitter and receiver modules are built using inexpensive off-the-shelf
components. Both modules are compact allowing the generation of renewed shared
secrets on demand over a short range of a few metres. An analysis of the
software is shown as well as results of error rates and therefore shared secret
yields at varying background light levels. As the system is designed to
eventually work in short-range consumer applications, we also present a use
scenario where the consumer can regularly 'top up' a store of secrets for use
in a variety of one-time-pad and authentication protocols.Comment: 18 pages, 9 figures, to be published in New Journal of Physic
Extracting inter-dot tunnel couplings between few donor quantum dots in silicon
The long term scaling prospects for solid-state quantum computing architectures relies heavily on the
ability to simply and reliably measure and control the coherent electron interaction strength, known
as the tunnel coupling, tc. Here, we describe a method to extract the tc between two quantum dots
(QDs) utilising their different tunnel rates to a reservoir. We demonstrate the technique on a few
donor triple QD tunnel coupled to a nearby single-electron transistor(SET)in silicon. The device was
patterned using scanning tunneling microscopy-hydrogen lithography allowing for a direct
measurement of the tunnel coupling for a given inter-dot distance. We extract tc = ± 5.5 1.8 GHz
and tc = ± 2.2 1.3 GHz between each of the nearest-neighbour QDs which are separated by 14.5 nm
and 14.0 nm, respectively. The technique allows for an accurate measurement of tc for nanoscale
devices even when it is smaller than the electron temperature and is an ideal characterisation tool for
multi-dot systems with a charge senso
Beyond small-scale transients: a closer look at the diffuse quiet solar corona
Within the quiet Sun corona imaged at 1 MK, much of the field of view
consists of diffuse emission that appears to lack the spatial structuring that
is so evident in coronal loops or bright points. We seek to determine if these
diffuse regions are categorically different in terms of their intensity
fluctuations and spatial configuration from the more well-studied dynamic
coronal features. We analyze a time series of observations from Solar Orbiter's
High Resolution Imager in the Extreme Ultraviolet to quantify the
characterization of the diffuse corona at high spatial and temporal
resolutions. We then compare this to the dynamic features within the field of
view, mainly a coronal bright point. We find that the diffuse corona lacks
visible structuring, such as small embedded loops, and that this is persistent
over the 25 min duration of the observation. The intensity fluctuations of the
diffuse corona, which are within +/-5%, are significantly smaller in comparison
to the coronal bright point. Yet, the total intensity observed in the diffuse
corona is of the same order as the bright point. It seems inconsistent with our
data that the diffuse corona is a composition of small loops or jets or that it
is driven by discrete small heating events that follow a power-law-like
distribution. We speculate that small-scale processes like MHD turbulence might
be energizing the diffuse regions, but at this point we cannot offer a
conclusive explanation for the nature of this feature.Comment: Accepted for publication in A&A. 10 pages, 8 figure
Tunneling statistics for analysis of spin-readout fidelity
We investigate spin and charge dynamics of a quantum dot of phosphorus atoms
coupled to a radio-frequency single-electron transistor (rf-SET) using full
counting statistics. We show how the magnetic field plays a role in determining
the bunching or anti-bunching tunnelling statistics of the donor dot and SET
system. Using the counting statistics we show how to determine the lowest
magnetic field where spin-readout is possible. We then show how such a
measurement can be used to investigate and optimise single electron
spin-readout fidelity.Comment: 11 pages, 6 figure
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