738 research outputs found
Examining the consistency and coherence of values in young children using a new animated values instrument
The existence and formation of values across the lifespan has been of particular interest to psychology researchers for decades. In this study we examine the consistency and coherence of values in early childhood using a new animated instrument - the AVI (Animated Values Instrument). Based on Schwartz's circular values structure the AVI is a multi-sensory instrument designed to enhance young children's understanding of each value. We present evidence from a sample of 329 five to twelve year-olds that shows children, as young as five, make consistent choices about their own values. Results show that consistency of choice is high for the majority of children across all age groups and complete consistency of choice in almost all older children. We also demonstrate coherence in the circular structure of values in young children at the sample and individual level for the first time. The discussion outlines new directions for future research on the development of values in young children
On the nature of the z=0 X-ray absorbers: I. Clues from an external group
Absorption lines of OVII at redshift zero are observed in high quality
Chandra spectra of extragalactic sightlines. The location of the absorber
producing these lines, whether from the corona of the Galaxy or from the Local
Group or even larger scale structure, has been a matter of debate. Here we
study another poor group like our Local Group to understand the distribution of
column density from galaxy to group scales. We show that we cannot yet rule out
the group origin of z=0 systems. We further argue that the debate over Galactic
vs. extragalactic origin of z=0 systems is premature as they likely contain
both components and predict that future higher resolution observations will
resolve the z=0 systems into multiple components.Comment: Submitted to ApJ
Inhibition of somatosensory mechanotransduction by annexin A6
Mechanically activated, slowly adapting currents in sensory neurons have been linked to noxious mechanosensation. The conotoxin NMB-1 (noxious mechanosensation blocker-1) blocks such currents and inhibits mechanical pain. Using a biotinylated form of NMB-1 in mass spectrometry analysis, we identified 67 binding proteins in sensory neurons and a sensory neuron-derived cell line, of which the top candidate was annexin A6, a membrane-associated calcium-binding protein. Annexin A6-deficient mice showed increased sensitivity to mechanical stimuli. Sensory neurons from these mice showed increased activity of the cation channel Piezo2, which mediates a rapidly adapting mechano-gated current linked to proprioception and touch, and a decrease in mechanically activated, slowly adapting currents. Conversely, overexpression of annexin A6 in sensory neurons inhibited rapidly adapting currents that were partially mediated by Piezo2. Furthermore, overexpression of annexin A6 in sensory neurons attenuated mechanical pain in a mouse model of osteoarthritis, a disease in which mechanically evoked pain is particularly problematic. These data suggest that annexin A6 can be exploited to inhibit chronic mechanical pain
A standardized method for plasma extracellular vesicle isolation and size distribution analysis
The following protocol describes our workflow for isolation and quantification of plasma extracellular vesicles (EVs). It requires limited sample volume so that the scientific value of specimens is maximized. These steps include isolation of vesicles by automated size exclusion chromatography and quantification by tunable resistive pulse sensing. This workflow optimizes reproducibility by minimizing variations in processing, handling, and storage of EVs. EVs have significant diagnostic and therapeutic potential, but clinical application is limited by disparate methods of data collection. This standardized protocol is scalable and ensures efficient recovery of physiologically intact EVs that may be used in a variety of downstream biochemical and functional analyses. Simultaneous measurement quantifies EV concentration and size distribution absolutely. Absolute quantification corrects for variations in EV number and size, offering a novel method of standardization in downstream applications
Associated Higgs production with top quarks at the Large Hadron Collider: NLO QCD corrections
We present in detail the calculation of the O(alpha_s^3) inclusive total
cross section for the process pp -> t-tbar-h, in the Standard Model, at the
CERN Large Hadron Collider with center-of-mass energy sqrt(s_H)=14 TeV. The
calculation is based on the complete set of virtual and real O(alpha_s)
corrections to the parton level processes q-qbar -> t-tbar-h and gg ->
t-tbar-h, as well as the tree level processes (q,qbar)g -> t-tbar-h-(q,qbar).
The virtual corrections involve the computation of pentagon diagrams with
several internal and external massive particles, first encountered in this
process. The real corrections are computed using both the single and the two
cutoff phase space slicing method. The next-to-leading order QCD corrections
significantly reduce the renormalization and factorization scale dependence of
the Born cross section and moderately increase the Born cross section for
values of the renormalization and factorization scales above m_t.Comment: 70 pages, 12 figures, RevTeX4: one word changed in the abstract, one
sentence reworded in the introduction. To appear in Phys. Rev.
Strange quark matter in a chiral SU(3) quark mean field model
We apply the chiral SU(3) quark mean field model to investigate strange quark
matter. The stability of strange quark matter with different strangeness
fraction is studied. The interaction between quarks and vector mesons
destabilizes the strange quark matter. If the strength of the vector coupling
is the same as in hadronic matter, strangelets can not be formed. For the case
of beta equilibrium, there is no strange quark matter which can be stable
against hadron emission even without vector meson interactions.Comment: 19 pages, 8 figure
Saturn's icy satellites and rings investigated by Cassini - VIMS. III. Radial compositional variability
In the last few years Cassini-VIMS, the Visible and Infared Mapping
Spectrometer, returned to us a comprehensive view of the Saturn's icy
satellites and rings. After having analyzed the satellites' spectral properties
(Filacchione et al. (2007a)) and their distribution across the satellites'
hemispheres (Filacchione et al. (2010)), we proceed in this paper to
investigate the radial variability of icy satellites (principal and minor) and
main rings average spectral properties. This analysis is done by using 2,264
disk-integrated observations of the satellites and a 12x700 pixels-wide rings
radial mosaic acquired with a spatial resolution of about 125 km/pixel. The
comparative analysis of these data allows us to retrieve the amount of both
water ice and red contaminant materials distributed across Saturn's system and
the typical surface regolith grain sizes. These measurements highlight very
striking differences in the population here analyzed, which vary from the
almost uncontaminated and water ice-rich surfaces of Enceladus and Calypso to
the metal/organic-rich and red surfaces of Iapetus' leading hemisphere and
Phoebe. Rings spectra appear more red than the icy satellites in the visible
range but show more intense 1.5-2.0 micron band depths. The correlations among
spectral slopes, band depths, visual albedo and phase permit us to cluster the
saturnian population in different spectral classes which are detected not only
among the principal satellites and rings but among co-orbital minor moons as
well. Finally, we have applied Hapke's theory to retrieve the best spectral
fits to Saturn's inner regular satellites using the same methodology applied
previously for Rhea data discussed in Ciarniello et al. (2011).Comment: 44 pages, 27 figures, 7 tables. Submitted to Icaru
Neutrino Emission from Goldstone Modes in Dense Quark Matter
We calculate neutrino emissivities from the decay and scattering of Goldstone
bosons in the color-flavor-locked (CFL) phase of quarks at high baryon density.
Interactions in the CFL phase are described by an effective low-energy theory.
For temperatures in the tens of keV range, relevant to the long-term cooling of
neutron stars, the emissivities involving Goldstone bosons dominate over those
involving quarks, because gaps in the CFL phase are MeV while the
masses of Goldstone modes are on the order of 10 MeV. For the same reason, the
specific heat of the CFL phase is also dominated by the Goldstone modes.
Notwithstanding this, both the emissivity and the specific heat from the
massive modes remain rather small, because of their extremely small number
densities. The values of the emissivity and the specific heat imply that the
timescale for the cooling of the CFL core in isolation is y,
which makes the CFL phase invisible as the exterior layers of normal matter
surrounding the core will continue to cool through significantly more rapid
processes. If the CFL phase appears during the evolution of a proto-neutron
star, neutrino interactions with Goldstone bosons are expected to be
significantly more important since temperatures are high enough (
MeV) to admit large number densities of Goldstone modes.Comment: 29 pages, no figures. slightly modified text, one new eqn. and new
refs. adde
Negative Parity 70-plet Baryon Masses in the 1/Nc Expansion
The masses of the negative parity SU(6) 70-plet baryons are analyzed in the
1/Nc expansion to order 1/Nc and to first order in SU(3) breaking. At this
level of precision there are twenty predictions. Among them there are the well
known Gell-Mann Okubo and equal spacing relations, and four new relations
involving SU(3) breaking splittings in different SU(3) multiplets. Although the
breaking of SU(6) symmetry occurs at zeroth order in 1/Nc, it turns out to be
small. The dominant source of the breaking is the hyperfine interaction which
is of order 1/Nc. The spin-orbit interaction, of zeroth order in 1/Nc, is
entirely fixed by the splitting between the singlet states Lambda(1405) and
Lambda(1520), and the spin-orbit puzzle is solved by the presence of other
zeroth order operators involving flavor exchange.Comment: 31 pages, 3 figure
The Structure of Jupiter, Saturn, and Exoplanets: Key Questions for High-Pressure Experiments
We give an overview of our current understanding of the structure of gas
giant planets, from Jupiter and Saturn to extrasolar giant planets. We focus on
addressing what high-pressure laboratory experiments on hydrogen and helium can
help to elucidate about the structure of these planets.Comment: Invited contribution to proceedings of High Energy Density Laboratory
Astrophysics, 6. Accepted to Astrophysics & Space Science. 12 page
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