1,357 research outputs found
Reply to Comment on "Reevaluation of the parton distribution of strange quarks in the nucleon"
A Comment on the recently published reevaluation of the polarization-averaged
parton distribution of strange quarks in the nucleon using final data on the
multiplicities of charged kaons in semi-inclusive deep-inelastic scattering is
reviewed. Important features of the comparison of one-dimensional projections
of the multidimensional HERMES data are pointed out. A test of the
leading-order extraction of xS(x) using the difference between charged-kaon
multiplicities is repeated. The results are consistent with leading-order
predictions within the uncertainties in the input data, and do not invalidate
the earlier extraction of xS(x).Comment: Reply Comment to arXiv:1407.372
Correction: Statin Use and Cognitive Function:Population-Based Observational Study with Long-Term Follow-Up (vol 9, e115755, 2014)
Frauenforschung in der Soziologie - quo vadis?
It is widely accepted that the devastating consequences of spinal cord injury are due to the failure of lesioned CNS axons to regenerate. The current study of the spontaneous tissue repair processes following dorsal hemisection of the adult rat spinal cord demonstrates a phase of rapid and substantial nerve fibre in‐growth into the lesion that was derived largely from both rostral and caudal spinal tissues. The response was characterized by increasing numbers of axons traversing the clearly defined interface between the lesion and the adjacent intact spinal cord, beginning by 5 days post operation (p.o.). Having penetrated the lesion, axons became associated with a framework of NGFr‐positive non‐neuronal cells (Schwann cells and leptomeningeal cells). Surprisingly few of these axons were derived from CGRP‐ or SP‐immunoreactive dorsal root ganglion neurons. At the longest survival time (56 days p.o.), there was a marked shift in the overall orientation of fibres from a largely rostro‐caudal to a dorso‐ventral axis. Attempts to identify which recognition molecules may be important for these re‐organizational processes during attempted tissue repair demonstrated the widespread and intense expression of the cell adhesion molecules (CAM) L1 and N‐CAM. Double immunofluorescence suggested that both Schwann cells and leptomeningeal cells contributed to the pattern of CAM expression associated with the cellular framework within the lesion
Beam-helicity asymmetries for single-hadron production in semi-inclusive deep-inelastic scattering from unpolarized hydrogen and deuterium targets
A measurement of beam-helicity asymmetries for single-hadron production in
deep-inelastic scattering is presented. Data from the scattering of 27.6 GeV
electrons and positrons off gaseous hydrogen and deuterium targets were
collected by the HERMES experiment. The asymmetries are presented separately as
a function of the Bjorken scaling variable, the hadron transverse momentum, and
the fractional energy for charged pions and kaons as well as for protons and
anti-protons. These asymmetries are also presented as a function of the three
aforementioned kinematic variables simultaneously
Diffusing-wave spectroscopy of nonergodic media
We introduce an elegant method which allows the application of diffusing-wave
spectroscopy (DWS) to nonergodic, solid-like samples. The method is based on
the idea that light transmitted through a sandwich of two turbid cells can be
considered ergodic even though only the second cell is ergodic. If absorption
and/or leakage of light take place at the interface between the cells, we
establish a so-called "multiplication rule", which relates the intensity
autocorrelation function of light transmitted through the double-cell sandwich
to the autocorrelation functions of individual cells by a simple
multiplication. To test the proposed method, we perform a series of DWS
experiments using colloidal gels as model nonergodic media. Our experimental
data are consistent with the theoretical predictions, allowing quantitative
characterization of nonergodic media and demonstrating the validity of the
proposed technique.Comment: RevTeX, 12 pages, 6 figures. Accepted for publication in Phys. Rev.
Treatable Vascular Risk and Cognitive Performance in Persons Aged 35 Years or Older:Longitudinal Study of Six Years
BACKGROUND: Poor cognitive performance is associated with high vascular risk. However, this association is only investigated in elderly. As neuropathological changes precede clinical symptoms of cognitive impairment by several decades, it is likely that cognitive performance is already associated with vascular risk at middle-age. OBJECTIVES: To investigate the association of cognitive performance with treatable vascular risk in middle-aged and old persons. DESIGN: Longitudinal study with three measurements during follow-up period of 5.5 years. SETTING: City of Groningen, the Netherlands. PARTICIPANTS: Cohort of 3,572 participants (age range, 35-82 years; mean age, 54 years; men, 52%). EXPOSURE: Treatable vascular risk as defined by treatable components of the Framingham Risk Score for Cardiovascular Disease at the first measurement (diabetes mellitus, smoking, hypercholesterolemia and hypertension). MEASUREMENTS: Change in cognitive performance during follow-up. Cognitive performance was measured with Ruff Figural Fluency Test (RFFT) and Visual Association Test (VAT), and calculated as the average of the standardized RFFT and VAT score per participant. RESULTS: The mean (SD) cognitive performance changed from 0.00 (0.79) at the first measurement to 0.15 (0.83) at second measurement and to 0.39 (0.82) at the third measurement (Ptrend CONCLUSIONS: Change in cognitive performance was associated with treatable vascular risk in persons aged 35 years or older
Light-scattering technique for the study of dynamic thickness fluctuations in thin liquid films
Target and beam-target spin asymmetries in exclusive pion electroproduction for Q2>1GeV2 . I. ep→eπ+n
Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive
π
+
electroproduction reaction
γ
∗
p
→
n
π
+
. The results were obtained from scattering of 6-GeV longitudinally polarized electrons off longitudinally polarized protons using the CEBAF Large Acceptance Spectrometer at Jefferson Laboratory. The kinematic range covered is
1.1
<
W
<
3
GeV and
1
<
Q
2
<
6
GeV
2
. Results were obtained for about 6000 bins in
W
,
Q
2
,
cos
(
θ
∗
)
, and
ϕ
∗
. Except at forward angles, very large target-spin asymmetries are observed over the entire
W
region. Reasonable agreement is found with phenomenological fits to previous data for
W
<
1.6
GeV, but very large differences are seen at higher values of
W
. A generalized parton distributions (GPD)-based model is in poor agreement with the data. When combined with cross-sectional measurements, the present results provide powerful constraints on nucleon resonance amplitudes at moderate and large values of
Q
2
, for resonances with masses as high as 2.4 GeV
Transverse-target-spin asymmetry in exclusive -meson electroproduction
Hard exclusive electroproduction of mesons is studied with the
HERMES spectrometer at the DESY laboratory by scattering 27.6 GeV positron and
electron beams off a transversely polarized hydrogen target. The amplitudes of
five azimuthal modulations of the single-spin asymmetry of the cross section
with respect to the transverse proton polarization are measured. They are
determined in the entire kinematic region as well as for two bins in photon
virtuality and momentum transfer to the nucleon. Also, a separation of
asymmetry amplitudes into longitudinal and transverse components is done. These
results are compared to a phenomenological model that includes the pion pole
contribution. Within this model, the data favor a positive
transition form factor.Comment: DESY Report 15-14
- …