3,258 research outputs found
Particle-Antiparticle Asymmetries of Production in Hadron-Nucleon Collisions
The particle-antiparticle asymmetries of production in 250 GeV/c
, , and --nucleon collisions are studied with two model
parametrizations of quark to fragmentation functions. It is shown
that the available data can be qualitatively explained by the calculated
results in both the quark-diquark model and a pQCD based analysis of
fragmentation functions. The differences in the two model predictions are
significant for beams, and high precision measurements of the
asymmetries with detailed and information can discriminate between
different predictions.Comment: 14 LaTex pages, 4 figures, to appear in Phys. Lett.
Phenomenological Relation between Distribution and Fragmentation Functions
We study the relation between the quark distribution function q(x) and the
fragmentation function D_q(z) based on a general form D_q(x) =
C(z)z^{alpha}q(z) for valence and sea quarks. By adopting two known
parametrizations of quark distributions for the proton, we find three simple
options for the fragmentation functions that can provide a good description of
the available experimental data on proton production in e^+ e^- inelastic
annihilation. These three options support the revised Gribov-Lipatov relation
D_q(z) = z q(z) at z --> 1, as an approximate relation for the connection
between distribution and fragmentation functions. The three options differ in
the sea contributions and lead to distinct predictions for antiproton
production in the reaction p+p --> p-bar+X, thus they are distinguishable in
future experiments at RHIC-BNL.Comment: 13 pages, 5 eps figure
Blood-brain barrier-associated pericytes internalize and clear aggregated amyloid-β42 by LRP1-dependent apolipoprotein E isoform-specific mechanism
Table S1. Demographic and clinical features of human subjects used in this study. Figure S1. Aβ deposition in microvessels in AD patients and APPSw/0 mice. Figure S2. Biochemical analysis of Aβ42 aggregates. Figure S3. Cy3-Aβ42 cellular uptake in wild type mouse brain slices within 30 min. Figure S4. Pericyte coverages in Lrp1lox/lox and Lrp1lox/lox; Cspg4-Cre mice. Figure S5.. LRP1 and apoE suppression with siRNA. (DOCX 1454 kb
Touch and Go: Learning from Human-Collected Vision and Touch
The ability to associate touch with sight is essential for tasks that require
physically interacting with objects in the world. We propose a dataset with
paired visual and tactile data called Touch and Go, in which human data
collectors probe objects in natural environments using tactile sensors, while
simultaneously recording egocentric video. In contrast to previous efforts,
which have largely been confined to lab settings or simulated environments, our
dataset spans a large number of "in the wild" objects and scenes. To
demonstrate our dataset's effectiveness, we successfully apply it to a variety
of tasks: 1) self-supervised visuo-tactile feature learning, 2) tactile-driven
image stylization, i.e., making the visual appearance of an object more
consistent with a given tactile signal, and 3) predicting future frames of a
tactile signal from visuo-tactile inputs.Comment: Accepted by NeurIPS 2022 Track of Datasets and Benchmark
Site-specific associations of muscle thickness with bone mineral density in middle-aged and older men and women
It is unknown whether age-related site-specific muscle loss is associated with areal bone mineral density (aBMD) in older adults. To examine the relationships between aBMD and whole-body muscle thickness distribution, 97 healthy adults (46 women and 51 men) aged 50–78 years volunteered. Total and appendicular lean soft tissue mass, aBMD of the lumbar spine (LS-aBMD) and femoral neck (FN-aBMD) were determined using dual-energy X-ray absorptiometry. Muscle thickness (MT) was measured by ultrasound at nine sites of the body (forearm, upper arm, trunk, upper leg, and lower leg). Relationships of each co-variate with aBMD were tested partialling out the effect of age. aBMD was not correlated with either MT of the trunk or anterior lower leg in either sex. In men, significant and relatively strong correlations were observed between anterior and posterior upper arms, posterior lower leg, and anterior upper leg MT and LS-aBMD or FN-aBMD. In women, significant correlations were observed between anterior and posterior upper legs, posterior lower leg, and anterior upper arm MT and FN-aBMD. LS-aBMD was only correlated with forearm and posterior upper leg MT in women. In conclusion, the site-specific association of MT and aBMD differs between sexes and may be associated with the participants’ daily physical activity profile
Kinetic models for dilute solutions of dumbbells in non-homogeneous flows revisited
We propose a two fluid theory to model a dilute polymer solution assuming
that it consists of two phases, polymer and solvent, with two distinct
macroscopic velocities. The solvent phase velocity is governed by the
macroscopic Navier-Stokes equations with the addition of a force term
describing the interaction between the two phases. The polymer phase is
described on the mesoscopic level using a dumbbell model and its macroscopic
velocity is obtained through averaging. We start by writing down the full
phase-space distribution function for the dumbbells and then obtain the
inertialess limits for the Fokker-Planck equation and for the averaged friction
force acting between the phases from a rigorous asymptotic analysis. The
resulting equations are relevant to the modelling of strongly non-homogeneous
flows, while the standard kinetic model is recovered in the locally homogeneous
case
Structure-property and composition-property relationships for poly(ethylene terephthalate) surfaces modified by helium plasma-based ion implantation
The surfaces of untreated and helium plasma-based ion implantation (He PBII) treated poly(ethylene terephthalate) (PET) samples were characterised by reflectance colorimetry, contact angle studies and measurements of surface electrical resistance. The results were related to the structural and compositional data obtained by the authors earlier on parallel samples by XPS and Raman spectroscopy. Inverse correlations between lightness and ID/IG ratio and between chroma and ID/IG ratio were obtained, suggesting that the PBII-treated PET samples darken and their colourfulness decreases with the increase of the portion of aromatic sp2 carbon rings in the chemical structure of the modified layer. Direct correlation between water contact angle and the ID/IG ratio and inverse correlations between surface energy and ID/IG ratio and between dispersive component of surface energy and ID/IG ratio were found, reflecting that surface wettability, surface energy and its dispersive component decrease with the formation of surface structure, characterised again by enhanced portion of aromatic sp2 carbon rings. The surface electrical resistance decreased with the increase of the surface C-content determined by XPS and also with the increase of the surface concentration of conjugated double bonds, reflected by the increase of the pi-pi* shake-up satellite of the C 1s peak
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