1,971 research outputs found
Grouping time series by pairwise measures of redundancy
A novel approach is proposed to group redundant time series in the frame of
causality. It assumes that (i) the dynamics of the system can be described
using just a small number of characteristic modes, and that (ii) a pairwise
measure of redundancy is sufficient to elicit the presence of correlated
degrees of freedom. We show the application of the proposed approach on fMRI
data from a resting human brain and gene expression profiles from HeLa cell
culture.Comment: 4 pages, 8 figure
Self-assembled-monolayer formation of long alkanedithiols in molecular junctions
The orientation of alkanedithiol molecules in self-assembled monolayers (SAMs) is of vital importance for their transport properties in molecular junctions. It is demonstrated that a too-low concentration of long alkanedithiols in ethanol leads to the formation of looped molecules, resulting in a 50-fold increase of the current through the SAM. X-ray photoelectron spectroscopy measurements show that high-concentration dithiol solutions result in a preferential standing-up phase. To obtain an almost full standing-up phase of 1,14-tetradecanedithiol (C14) a 30 mM concentration in ethanol is required, whereas a 0.3 mM concentration leads to a highly looped monolayer. The conduction through the full standing-up phase of C14 and C16 is in accordance with the exponential dependence on molecule length as obtained from shorter alkanedithiols
CFL1, a WW Domain Protein, Regulates Cuticle Development by Modulating the Function of HDG1, a Class IV Homeodomain Transcription Factor, in Rice and Arabidopsis
A confinement model calculation of h_1(x)
The transverse polarization distribution of quarks is computed in a
confinement model, the chiral chromodielectric model. The flavor structure of
, its evolution and Soffer's inequality are studied. The Drell--Yan
double transverse asymmetry is evaluated and found to be one order of
magnitude smaller than the double longitudinal asymmetry.Comment: 11 pages, 5 PostScript figures in an uuencoded file h1figures.u
Resonance peak in underdoped cuprates
The magnetic susceptibility measured in neutron scattering experiments in
underdoped YBaCuO is interpreted based on the self-consistent
solution of the t-J model of a Cu-O plane. The calculations reproduce correctly
the frequency and momentum dependencies of the susceptibility and its variation
with doping and temperature in the normal and superconducting states. This
allows us to interpret the maximum in the frequency dependence -- the resonance
peak -- as a manifestation of the excitation branch of localized Cu spins and
to relate the frequency of the maximum to the size of the spin gap. The
low-frequency shoulder well resolved in the susceptibility of superconducting
crystals is connected with a pronounced maximum in the damping of the spin
excitations. This maximum is caused by intense quasiparticle peaks in the hole
spectral function for momenta near the Fermi surface and by the nesting.Comment: 9 pages, 6 figure
Primary Care Informatics Response to Covid-19 Pandemic: Adaptation, Progress, and Lessons from Four Countries with High ICT Development
OBJECTIVE: Internationally, primary care practice had to transform in response to the COVID pandemic. Informatics issues included access, privacy, and security, as well as patient concerns of equity, safety, quality, and trust. This paper describes progress and lessons learned. METHODS: IMIA Primary Care Informatics Working Group members from Australia, Canada, United Kingdom and United States developed a standardised template for collection of information. The template guided a rapid literature review. We also included experiential learning from primary care and public health perspectives. RESULTS: All countries responded rapidly. Common themes included rapid reductions then transformation to virtual visits, pausing of non-COVID related informatics projects, all against a background of non-standardized digital development and disparate territory or state regulations and guidance. Common barriers in these four and in less-resourced countries included disparities in internet access and availability including bandwidth limitations when internet access was available, initial lack of coding standards, and fears of primary care clinicians that patients were delaying care despite the availability of televisits. CONCLUSIONS: Primary care clinicians were able to respond to the COVID crisis through telehealth and electronic record enabled change. However, the lack of coordinated national strategies and regulation, assurance of financial viability, and working in silos remained limitations. The potential for primary care informatics to transform current practice was highlighted. More research is needed to confirm preliminary observations and trends noted
Multistep Parametric Processes in Nonlinear Optics
We present a comprehensive overview of different types of parametric
interactions in nonlinear optics which are associated with simultaneous
phase-matching of several optical processes in quadratic nonlinear media, the
so-called multistep parametric interactions. We discuss a number of
possibilities of double and multiple phase-matching in engineered structures
with the sign-varying second-order nonlinear susceptibility, including (i)
uniform and non-uniform quasi-phase-matched (QPM) periodic optical
superlattices, (ii) phase-reversed and periodically chirped QPM structures, and
(iii) uniform QPM structures in non-collinear geometry, including recently
fabricated two-dimensional nonlinear quadratic photonic crystals. We also
summarize the most important experimental results on the multi-frequency
generation due to multistep parametric processes, and overview the physics and
basic properties of multi-color optical parametric solitons generated by these
parametric interactions.Comment: To be published in Progress in Optic
Transverse Polarisation of Quarks in Hadrons
We review the present state of knowledge regarding the transverse
polarisation (or transversity) distributions of quarks. After some generalities
on transverse polarisation, we formally define the transversity distributions
within the framework of a classification of all leading-twist distribution
functions. We describe the QCD evolution of transversity at leading and
next-to-leading order. A comprehensive treatment of non-perturbative
calculations of transversity distributions (within the framework of quark
models, lattice QCD and QCD sum rules) is presented. The phenomenology of
transversity (in particular, in Drell-Yan processes and semi-inclusive
leptoproduction) is discussed in some detail. Finally, the prospects for future
measurements are outlined.Comment: small changes, references added, as finally published in Physics
Report
Laser Acceleration of Highly Energetic Carbon Ions Using a Double-Layer Target Composed of Slightly Underdense Plasma and Ultrathin Foil
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