1,226 research outputs found
Anthony\u27s Silence: The Intersection of Sex, Gender and Race in \u3cem\u3eDesigning Women\u3c/em\u3e
Editor\u27s Note: Lynn H. Turner and Helen Sterk examine one small part of the Designing Women script, a short speech by Anthony (one of the series\u27 regulars). They argue that, as the only African American male in the series, Anthony was in a unique position to examine the gender and race issues posed by the Thomas/Hill hearings, and by the Thomas nomination itself. Calling on writings by African .American scholars commenting on the Senate hearings and on race and gender issues generally, the authors conclude that the structure of Anthony\u27s speech represents a missed opportunity
The effect of turbulent flow structures on saltation sand transport in the atmospheric boundary layer
Master equation approach to magnon relaxation and dephasing
There has been a recent upsurge of interest in the quantum properties of
magnons for quantum information processing. An important issue is to examine
the stability of quantum states of magnons against various relaxation and
dephasing channels. Since the interaction of magnons in magnetic systems may
fall in the ultra-strong and even deep-strong coupling regimes, the relaxation
process of magnon states is quite different from the more common quantum
optical systems. Here we study the relaxation and dephasing of magnons based on
the Lindblad formalism and derive a generalized master equation that describes
the quantum dynamics of magnons. Employing this master equation, we identify
two distinct dissipation channels for squeezed magnons, i.e., the local
dissipation and collective dissipation, which play a role for both ferromagnets
and antiferromagnets. The local dissipation is caused by the independent
exchange of angular momentum between the magnonic system and the environment,
while the collective dissipation is dressed by the parametric interactions of
magnons and it enhances the quantumness and thermal stability of squeezed
magnons. Further, we show how this formalism can be applied to study the pure
dephasing of magnons caused by four-magnon scattering and magnon-phonon
interactions. Our results provide the theoretical tools to study the
decoherence of magnons within a full quantum-mechanical framework and further
benefit the use of quantum states of magnons for information processing.Comment: 13 pages, 3 figure
Photon collection from a trapped ion--cavity system
We present the design and implementation of a trapped ion cavity QED system.
A single ytterbium ion is confined by a micron-scale ion trap inside a 2 mm
optical cavity. The ion is coherently pumped by near resonant laser light while
the cavity output is monitored as a function of pump intensity and cavity
detuning. We observe a Purcell enhancement of scattered light into the solid
angle subtended by the optical cavity, as well as a three-peak structure
arising from strongly driving the atom. This system can be integrated into
existing atom{photon quantum network protocols and is a pathway towards an
efficient atom{photon quantum interface
In vivo imaging of the airway wall in asthma: fibered confocal fluorescence microscopy in relation to histology and lung function
<p>Abstract</p> <p>Background</p> <p>Airway remodelling is a feature of asthma including fragmentation of elastic fibres observed in the superficial elastin network of the airway wall. Fibered confocal fluorescence microscopy (FCFM) is a new and non-invasive imaging technique performed during bronchoscopy that may visualize elastic fibres, as shown by <it>in vitro </it>spectral analysis of elastin powder. We hypothesized that FCFM images capture <it>in vivo </it>elastic fibre patterns within the airway wall and that such patterns correspond with airway histology. We aimed to establish the concordance between the bronchial elastic fibre pattern in histology and FCFM. Second, we examined whether elastic fibre patterns in histology and FCFM were different between asthmatic subjects and healthy controls. Finally, the association between these patterns and lung function parameters was investigated.</p> <p>Methods</p> <p>In a cross-sectional study comprising 16 subjects (8 atopic asthmatic patients with controlled disease and 8 healthy controls) spirometry and bronchoscopy were performed, with recording of FCFM images followed by endobronchial biopsy at the airway main carina. Elastic fibre patterns in histological sections and FCFM images were scored semi-quantitatively. Agreement between histology and FCFM was analysed using linearly weighted kappa κ<sub>w</sub>.</p> <p>Results</p> <p>The patterns observed in histological sections and FCFM images could be divided into 3 distinct groups. There was good agreement between elastic fibre patterns in histology and FCFM patterns (κ<sub>w </sub>0.744). The semi-quantitative pattern scores were not different between asthmatic patients and controls. Notably, there was a significant difference in post-bronchodilator FEV<sub>1 </sub>%predicted between the different patterns by histology (p = 0.001) and FCFM (p = 0.048), regardless of asthma or atopy.</p> <p>Conclusion</p> <p>FCFM captures the elastic fibre pattern within the airway wall in humans <it>in vivo</it>. The association between post-bronchodilator FEV<sub>1 </sub>%predicted and both histological and FCFM elastic fibre patterns points towards a structure-function relationship between extracellular matrix in the airway wall and lung function.</p> <p>Trial registration</p> <p>Netherlands Trial Register <a href="http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=NTR1306">NTR1306</a></p
Technical performance and diagnostic utility of the new Elecsys (R) neuron-specific enolase enzyme immunoassay
This international multicenter study was designed to evaluate the technical performance of the new double-monoclonal, single-step Elecsys neuron-specific enolase (NSE) enzyme immunoassay (EIA) and to assess its utility as a sensitive and specific test for the diagnosis of small-cell lung cancer (SCLC). Intra and interassay coefficients of variation, determined in five control or serum specimens in six laboratories, ranged from 0.7 to 5.3 (interlaboratory median: 1.3%) and from 1.3 to 8.5 (interlaboratory median: 3.4%), respectively. Laboratory-to-laboratory comparability was excellent with respect to recovery and interassay coefficients of variation. The test was linear between 0.0 and 320 ng/ml (highest measured concentration). There was a significant correlation between NSE concentrations measured using the Elecsys NSE and the established Cobas Core NSE EIA II in all subjects (n=723) and in patients with lung cancer (n=333). However, NSE concentrations were systematically lower (approximately 9%) with the Elecsys NSE than with the comparison test. Based on a specificity of 95% in comparison with the group suffering from benign lung diseases (n=183), the cutoff value for the discrimination between malignant and benign conditions was set at 21.6 ng/ml. NSE was raised in 73.4% of SCLC patients (n=188) and was significantly higher (p<0.01) in extensive (87.8%) as opposed to limited disease (56.7%). NSE was also elevated in 16.0% of the cases with non-small cell lung cancer (NSCLC, n=374). It is concluded that the Elecsys NSE EIA is a reliable and accurate diagnostic procedure for the measurement of NSE in serum samples. The special merits of this new assay are the wide measuring range (according to manufacturers declaration up to 370 ng/ml) and a short incubation time of 18 min
Meeting Report: Hackathon-Workshop on Darwin Core and MIxS Standards Alignment
The Global Biodiversity Information Facility and the Genomic Standards Consortium convened a joint workshop at the University of Oxford, 27–29 February 2012, with a small group of experts from Europe, USA, China and Japan, to continue the alignment of the Darwin Core with the MIxS and related genomics standards. Several reference mappings were produced as well as test expressions of MIxS in RDF. The use and management of controlled vocabulary terms was considered in relation to both GBIF and the GSC, and tools for working with terms were reviewed. Extensions for publishing genomic biodiversity data to the GBIF network via a Darwin Core Archive were prototyped and work begun on preparing translations of the Darwin Core to Japanese and Chinese. Five genomic repositories were identified for engagement to begin the process of testing the publishing of genomic data to the GBIF network commencing with the SILVA rRNA database
The Geometry and Moduli of K3 Surfaces
These notes will give an introduction to the theory of K3 surfaces. We begin
with some general results on K3 surfaces, including the construction of their
moduli space and some of its properties. We then move on to focus on the theory
of polarized K3 surfaces, studying their moduli, degenerations and the
compactification problem. This theory is then further enhanced to a discussion
of lattice polarized K3 surfaces, which provide a rich source of explicit
examples, including a large class of lattice polarizations coming from elliptic
fibrations. Finally, we conclude by discussing the ample and Kahler cones of K3
surfaces, and give some of their applications.Comment: 34 pages, 2 figures. (R. Laza, M. Schutt and N. Yui, eds.
Pure dephasing of magnonic quantum states
For a wide range of nonclassical magnonic states that have been proposed and demonstrated recently, a new time scale besides the magnon lifetime - the magnon dephasing time - becomes important, but this time scale is rarely studied. Considering exchange interaction and spin-phonon coupling, we evaluate the pure magnon dephasing time and find it to be smaller than the magnon lifetime at temperatures of a few kelvins. By examining a magnonic cat state as an example, we show how pure dephasing of magnons destroys and limits the survival of quantum superpositions. Thus it will be critical to perform quantum operations within the pure dephasing time. We further derive the master equation for the density matrix describing such magnonic quantum states taking into account the role of pure dephasing. This methodology can be generalized to include additional dephasing channels that experiments are likely to encounter in the future. Our findings enable one to design and manipulate robust quantum states of magnons for information processing
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