1,599 research outputs found
Atomic and Electronic Structure of a Rashba - Junction at the BiTeI Surface
The non-centrosymmetric semiconductor BiTeI exhibits two distinct surface
terminations that support spin-split Rashba surface states. Their ambipolarity
can be exploited for creating spin-polarized - junctions at the
boundaries between domains with different surface terminations. We use scanning
tunneling microscopy/spectroscopy (STM/STS) to locate such junctions and
investigate their atomic and electronic properties. The Te- and I-terminated
surfaces are identified owing to their distinct chemical reactivity, and an
apparent height mismatch of electronic origin. The Rashba surface states are
revealed in the STS spectra by the onset of a van Hove singularity at the band
edge. Eventually, an electronic depletion is found on interfacial Te atoms,
consistent with the formation of a space charge area in typical -
junctions.Comment: 5 pages, 4 figure
Experiences and needs of direct support staff working with people with intellectual disabilities during the COVID-19 pandemic:A thematic analysis
Background The present study aimed to explore the experiences and needs of direct support staff during the initial stage of the COVIDâ19 lockdown in the Netherlands. Method Overall, eleven direct support staff were recruited from five intellectual disability services to participate in this descriptive qualitative study. They recorded 34 audio messages during the considered period. Thematic analysis was used to analyse these audio recordings. Results Four themes emerged: (1) Emotional impact, which pertained to various emotions they experienced in their work; (2) Cognitive impact, which referred to challenges and changes they had undergone in their work; (3) Practical impact, which centred on the practical impact of the pandemic on their work; and (4) Professional impact, which concerned their experiences with other professionals. Conclusions This study provides valuable insights into the experiences and needs of direct support staff during the COVIDâ19 pandemic, which, in turn, can help inform practice in preparation for a second wave of COVIDâ19 or another future pandemic
The experiences of psychologists working with people with intellectual disabilities during the COVID-19 crisis
BACKGROUND: The aim of this study was to explore the experiences of psychologists working with people with intellectual disabilities during the initial stage of the COVIDâ19 lockdown in the Netherlands. METHOD: Five psychologists, who were affiliated with three intellectual disability services, participated in this descriptive qualitative study. Overall, they recorded 22 audio messages during the period under examination, which were analysed using thematic analysis. RESULTS: Three themes were identified: (a) Working from home; (b) Adapting to the new reality; and (c) Advising and coaching support staff. CONCLUSIONS: This study provides critical insights into the experiences of psychologists working with people with intellectual disabilities during the initial stage of the COVIDâ19 lockdown. These insights can help policymakers and practitioners to prepare for either a potential second wave of COVIDâ19 or a future pandemic
Glass transition in biomolecules and the liquid-liquid critical point of water
Using molecular dynamics simulations, we investigate the relation between the
dynamic transitions of biomolecules (lysozyme and DNA) and the dynamic and
thermodynamic properties of hydration water. We find that the dynamic
transition of the macromolecules, sometimes called a ``protein glass
transition'', occurs at the temperature of dynamic crossover in the diffusivity
of hydration water, and also coincides with the maxima of the isobaric specific
heat and the temperature derivative of the orientational order parameter.
We relate these findings to the hypothesis of a liquid-liquid critical point in
water. Our simulations are consistent with the possibility that the protein
glass transition results from crossing the Widom line, which is defined as the
locus of correlation length maxima emanating from the hypothesized second
critical point of water.Comment: 10 Pages, 12 figure
Electronic Instability in a Zero-Gap Semiconductor: The Charge-DensityWave in (TaSe4)(2)I
We report a comprehensive study of the paradigmatic quasi-1D compound (TaSe4)(2)I performed by means of angle-resolved photoemission spectroscopy (ARPES) and first-principles electronic structure calculations. We find it to be a zero-gap semiconductor in the nondistorted structure, with non-negligible interchain coupling. Theory and experiment support a Peierls-like scenario for the charge-density wave formation below T-CDW = 263 K, where the incommensurability is a direct consequence of the finite interchain coupling. The formation of small polarons, strongly suggested by the ARPES data, explains the puzzling semiconductor-to-semiconductor transition observed in transport at T-CDW.open114sciescopu
Ăvolution de la qualitĂ© de vie aprĂšs un traumatisme crĂąnien par accident de la route : un suivi Ă cinq ans de la cohorte ESPARR
Continua com: Info Ajuntament+Sostenible : notĂcies de l'Ajuntament+sostenibl
The momentum and photon energy dependence of the circular dichroic photoemission in the bulk Rashba semiconductors BiTeX (X = I, Br, Cl)
Bulk Rashba systems BiTeX (X = I, Br, Cl) are emerging as important
candidates for developing spintronics devices, because of the coexistence of
spin-split bulk and surface states, along with the ambipolar character of the
surface charge carriers. The need of studying the spin texture of strongly
spin-orbit coupled materials has recently promoted circular dichroic Angular
Resolved Photoelectron Spectroscopy (cd-ARPES) as an indirect tool to measure
the spin and the angular degrees of freedom. Here we report a detailed photon
energy dependent study of the cd-ARPES spectra in BiTeX (X = I, Br and Cl). Our
work reveals a large variation of the magnitude and sign of the dichroism.
Interestingly, we find that the dichroic signal modulates differently for the
three compounds and for the different spin-split states. These findings show a
momentum and photon energy dependence for the cd-ARPES signals in the bulk
Rashba semiconductor BiTeX (X = I, Br, Cl). Finally, the outcome of our
experiment indicates the important relation between the modulation of the
dichroism and the phase differences between the wave-functions involved in the
photoemission process. This phase difference can be due to initial or final
state effects. In the former case the phase difference results in possible
interference effects among the photo-electrons emitted from different atomic
layers and characterized by entangled spin-orbital polarized bands. In the
latter case the phase difference results from the relative phases of the
expansion of the final state in different outgoing partial waves.Comment: 6 pages, 4 figure
Evaluating 35 Methods to Generate Structural Connectomes Using Pairwise Classification
There is no consensus on how to construct structural brain networks from
diffusion MRI. How variations in pre-processing steps affect network
reliability and its ability to distinguish subjects remains opaque. In this
work, we address this issue by comparing 35 structural connectome-building
pipelines. We vary diffusion reconstruction models, tractography algorithms and
parcellations. Next, we classify structural connectome pairs as either
belonging to the same individual or not. Connectome weights and eight
topological derivative measures form our feature set. For experiments, we use
three test-retest datasets from the Consortium for Reliability and
Reproducibility (CoRR) comprised of a total of 105 individuals. We also compare
pairwise classification results to a commonly used parametric test-retest
measure, Intraclass Correlation Coefficient (ICC).Comment: Accepted for MICCAI 2017, 8 pages, 3 figure
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