410 research outputs found
Unveiling the Effect of Magnetic Noise in the Coherence of Single-Molecule Quantum Processors
Quantum bits (qubits) constitute the most elementary building-blocks of any quantum technology, where information is stored and processed in the form of quantum superpositions between discrete energy levels. In particular, the fabrication of quantum processors is a key long-term goal that will allow us conducting specific tasks much more efficiently than the most powerful classical computers can do. Motivated by recent experiments in which three addressable spin qubits are defined on a potential single-molecule quantum processor, namely the [Gd(H2O)P5W30O110]12− polyoxometalate, we investigate the decohering effect of magnetic noise on the encoded quantum information. Our state-of-the-art model, which provides more accurate results than previous estimates, show a noticeable contribution of magnetic noise in limiting the survival timescale of the qubits. Yet, our results suggest that it might not be the only dephasing mechanism at play but other mechanisms, such as lattice vibrations and physical movement of magnetic nuclei, must be considered to understand the whole decoherence process
Social support as a moderator in the relationship between intrusive thoughts and anxiety among Spanish-speaking Latinas with breast cancer.
ObjectiveIntrusive thoughts, defined as unwanted and recurrent thoughts about a stressful experience, are associated with psychological distress in women with breast cancer. This study assessed moderating effects of various social support dimensions on associations between intrusive thoughts and psychological distress among Latina breast cancer survivors.MethodsWe used baseline data from a randomized controlled trial of a stress management intervention delivered to 151 Spanish-speaking Latinas with nonmetastatic breast cancer within 1 year of diagnosis. Intrusive thoughts, four dimensions of social support (emotional/informational, tangible, affectionate, and positive social interaction), and symptoms of anxiety and depression were assessed through in-person interviews. Information on age, time since diagnosis, breast cancer variables, history of depression, and marital status served as covariates. Generalized linear models were used to investigate bivariate and multivariate associations and to explore moderation effects of the four dimensions of social support.ResultsIn bivariate models, intrusive thoughts were associated positively with depression (β = .024, .001) and anxiety (β = .047, P < .001) symptoms. Adjusting for other factors, intrusive thoughts remained associated with depression symptoms (β = .022, .008), regardless of level of social support (for all support dimensions). For anxiety, there were significant interactions of tangible (β = -.013, .034) and affectionate (β = -.022, .005) support with intrusive thoughts. Intrusive thoughts were associated more strongly with anxiety symptoms among women reporting less tangible and affectionate support than those with higher levels of these types of support.ConclusionsTangible and affectionate support have protective effects on anxiety symptoms among Spanish-speaking Latina breast cancer survivors experiencing intrusive thoughts, but not depression symptoms
A simulation method for fatigue-driven delamination in layered structures involving non-negligible fracture process zones and arbitrarily shaped crack fronts
Most of the existing methods for fatigue-driven delamination are limited to
two-dimensional (2D) applications or their predictive capabilities have not
been validated in three-dimensional (3D) problems. This work presents a new
cohesive zone-based computational method for simulating fatigue-driven
delamination in the analysis of 3D structures without crack migration. The
method accurately predicts fatigue propagation of non-nelgigible fracture
process zones with arbitrarily shaped delamination fronts. The model does not
require any kind of fitting parameter since all the input parameters are
obtained experimentally from coupon tests. The evaluation of the energy release
rate is done using two new techniques recently developed by the authors (the
growth driving direction and the mode-decomposed J-integral) leading to an
accurate prediction of delamination propagation under mixed-mode and
non-self-similar growing conditions. The new method has been implemented as a
UEL for Abaqus and validated against an experimental benchmark case with
varying crack growth rate and shape and extension of the fracture process zone.Comment: 37 pages, 14 figures, 7 table
New perspectives into Gluconobacter-catalysed biotransformations
Different from other aerobic microorganisms that oxidise carbon sources to water and carbon dioxide, Gluconobacter catalyses the incomplete oxidation of various substrates with regio- and stereoselectivity. This ability, as well as its capacity to release the resulting products into the reaction media, place Gluconobacter as a privileged member of a non-model microorganism class that may boost industrial biotechnology. Knowledge of new technologies applied to Gluconobacter has been piling up in recent years. Advancements in its genetic modification, application of immobilisation tools and careful designs of the transformations, have improved productivities and stabilities of Gluconobacter strains or enabled new bioconversions for the production of valuable marketable chemicals. In this work, the latest advancements applied to Gluconobacter-catalysed biotransformations are summarised with a special focus on recent available tools to improve them. From genetic and metabolic engineering to bioreactor design, the most recent works on the topic are analysed in depth to provide a comprehensive resource not only for scientists and technologists working on/with Gluconobacter, but for the general biotechnologist
CELL DEATH AND VIABILITY IN MARINE PHYTOPLANKTON
CITONATAplicación de ensayos in vitro para la detección precoz de ficotoxinas en muestras de poblaciones fitoplanctónicas multiespecífica
High spatial resolution optical imaging of the multiple T Tauri system LkH{\alpha} 262/LkH{\alpha} 263
We report high spatial resolution i' band imaging of the multiple T Tauri
system LkH 262/LkH 263 obtained during the first commissioning
period of the Adaptive Optics Lucky Imager (AOLI) at the 4.2 m William Herschel
Telescope, using its Lucky Imaging mode. AOLI images have provided photometry
for each of the two components LkH 263 A and B (0.41 arcsec separation)
and marginal evidence for an unresolved binary or a disc in LkH 262.
The AOLI data combined with previously available and newly obtained optical and
infrared imaging show that the three components of LkH 263 are
co-moving, that there is orbital motion in the AB pair, and, remarkably, that
LkH 262-263 is a common proper motion system with less than 1 mas/yr
relative motion. We argue that this is a likely five-component gravitationally
bounded system. According to BT-settl models the mass of each of the five
components is close to 0.4 M and the age is in the range 1-2 Myr. The
presence of discs in some of the components offers an interesting opportunity
to investigate the formation and evolution of discs in the early stages of
multiple very low-mass systems. In particular, we provide tentative evidence
that the disc in 263C could be coplanar with the orbit of 263AB.Comment: 11 pages, 7 figures, Accepted 2016 May
Wavelets, ridgelets and curvelets on the sphere
We present in this paper new multiscale transforms on the sphere, namely the
isotropic undecimated wavelet transform, the pyramidal wavelet transform, the
ridgelet transform and the curvelet transform. All of these transforms can be
inverted i.e. we can exactly reconstruct the original data from its
coefficients in either representation. Several applications are described. We
show how these transforms can be used in denoising and especially in a Combined
Filtering Method, which uses both the wavelet and the curvelet transforms, thus
benefiting from the advantages of both transforms. An application to component
separation from multichannel data mapped to the sphere is also described in
which we take advantage of moving to a wavelet representation.Comment: Accepted for publication in A&A. Manuscript with all figures can be
downloaded at http://jstarck.free.fr/aa_sphere05.pd
New Optical Insights into the Mass Discrepancy of Galaxy Clusters: The Cases of A1689 and A2218
We analyze the internal structures of clusters A1689 and A2218 by applying a
recent development of the method of wavelet analysis, which uses the complete
information obtained from optical data, i.e. galaxy positions and redshifts. We
find that both clusters show the presence of structures superimposed along the
line of sight with different mean redshifts and smaller velocity dispersions
than that of the system as a whole, suggesting that the clusters could be cases
of the on-going merging of clumps. In the case of A2218 we find an acceptable
agreement between our estimate of optical virial mass and X-ray and
gravitational lensing masses. On the contrary, in the case of A1689 we find
that our mass estimates are smaller than X-ray and gravitational lensing ones
at both small and large radii. In any case, at variance with earlier claims,
there is no evidence that X-ray mass estimates are underestimated.Comment: 8 pages, 2 eps figures, Use LaTeX2e, accepted by Astrophysical
Journal, in press November 1997, Vol.49
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