1,463 research outputs found
A prospective, population-based study of the role of visual impairment in motor vehicle crashes among older drivers: the SEE study.
PURPOSE: To determine the role of vision and visual attention factors in automobile crash involvement. METHODS: Drivers aged 65 to 84 years were identified during the baseline interview (1993-1995) of the Salisbury Eye Evaluation (SEE) Study. Crash involvement through December 1997 was determined from Maryland State motor vehicle records. Vision tests at baseline included distance acuity at normal and low luminance, contrast sensitivity, glare sensitivity, stereoacuity, and visual fields. Visual attention was evaluated with the Useful Field of View Test (UFOV; Visual Awareness, Chicago, IL). Survival analysis was used to determine the relative risk of a crash as a function of demographic variables, miles driven, vision, and visual attention. RESULTS: One hundred twenty (6.7%) of the 1801 drivers were involved in a crash during the observation interval. Glare sensitivity and binocular field loss were significant predictors of crash involvement (P < 0.05). For those with moderate or better vision (<3 letters for glare sensitivity and <20 points missed for binocular visual fields) increased glare sensitivity or reduced visual fields were, paradoxically, associated with a reduction in crash risk, whereas for those with poorer levels of vision, increased glare sensitivity or reduced visual fields were associated with increased crash risk. Worse UFOV score was associated with increased crash risk. CONCLUSIONS: Glare sensitivity, visual field loss, and UFOV were significant predictors of crash involvement. Acuity, contrast sensitivity, and stereoacuity were not associated with crashes. These results suggest that current vision screening for drivers' licensure, based primarily on visual acuity, may miss important aspects of visual impairment
MTG8 interacts with LHX6 to specify cortical interneuron subtype identity
Cortical interneurons originating in the embryonic medial ganglionic eminence (MGE) diverge into a range of different subtypes found in the adult mouse cerebral cortex. The mechanisms underlying this divergence and the timing when subtype identity is set up remain unclear. We identify the highly conserved transcriptional co-factor MTG8 as being pivotal in the development of a large subset of MGE cortical interneurons that co-expresses Somatostatin (SST) and Neuropeptide Y (NPY). MTG8 interacts with the pan-MGE transcription factor LHX6 and together the two factors are sufficient to promote expression of critical cortical interneuron subtype identity genes. The SST-NPY cortical interneuron fate is initiated early, well before interneurons migrate into the cortex, demonstrating an early onset specification program. Our findings suggest that transcriptional co-factors and modifiers of generic lineage specification programs may hold the key to the emergence of cortical interneuron heterogeneity from the embryonic telencephalic germinal zones
Neonatal-onset multisystem inflammatory disease responsive to interleukin-1 beta inhibition
BACKGROUND:Neonatal-onset multisystem inflammatory disease is characterized by fever, urticarial rash, aseptic meningitis, deforming arthropathy, hearing loss, and mental retardation. Many patients have mutations in the cold-induced autoinflammatory syndrome 1 (CIAS1) gene, encoding cryopyrin, a protein that regulates inflammation.METHODS:We selected 18 patients with neonatal-onset multisystem inflammatory disease (12 with identifiable CIAS1 mutations) to receive anakinra, an interleukin-1-receptor antagonist (1 to 2 mg per kilogram of body weight per day subcutaneously). In 11 patients, anakinra was withdrawn at three months until a flare occurred. The primary end points included changes in scores in a daily diary of symptoms, serum levels of amyloid A and C-reactive protein, and the erythrocyte sedimentation rate from baseline to month 3 and from month 3 until a disease flare.RESULTS:All 18 patients had a rapid response to anakinra, with disappearance of rash. Diary scores improved (P<0.001) and serum amyloid A (from a median of 174 mg to 8 mg per liter), C-reactive protein (from a median of 5.29 mg to 0.34 mg per deciliter), and the erythrocyte sedimentation rate decreased at month 3 (all P<0.001), and remained low at month 6. Magnetic resonance imaging showed improvement in cochlear and leptomeningeal lesions as compared with baseline. Withdrawal of anakinra uniformly resulted in relapse within days; retreatment led to rapid improvement. There were no drug-related serious adverse events.CONCLUSIONS:Daily injections of anakinra markedly improved clinical and laboratory manifestations in patients with neonatal-onset multisystem inflammatory disease, with or without CIAS1 mutations
The Stokes Phenomenon and Quantum Tunneling for de Sitter Radiation in Nonstationary Coordinates
We study quantum tunneling for the de Sitter radiation in the planar
coordinates and global coordinates, which are nonstationary coordinates and
describe the expanding geometry. Using the phase-integral approximation for the
Hamilton-Jacobi action in the complex plane of time, we obtain the
particle-production rate in both coordinates and derive the additional
sinusoidal factor depending on the dimensionality of spacetime and the quantum
number for spherical harmonics in the global coordinates. This approach
resolves the factor of two problem in the tunneling method.Comment: LaTex 10 pages, no figur
Shedding light on the elusive role of endothelial cells in cytomegalovirus dissemination.
Cytomegalovirus (CMV) is frequently transmitted by solid organ transplantation and is associated with graft failure. By forming the boundary between circulation and organ parenchyma, endothelial cells (EC) are suited for bidirectional virus spread from and to the transplant. We applied Cre/loxP-mediated green-fluorescence-tagging of EC-derived murine CMV (MCMV) to quantify the role of infected EC in transplantation-associated CMV dissemination in the mouse model. Both EC- and non-EC-derived virus originating from infected Tie2-cre(+) heart and kidney transplants were readily transmitted to MCMV-naïve recipients by primary viremia. In contrast, when a Tie2-cre(+) transplant was infected by primary viremia in an infected recipient, the recombined EC-derived virus poorly spread to recipient tissues. Similarly, in reverse direction, EC-derived virus from infected Tie2-cre(+) recipient tissues poorly spread to the transplant. These data contradict any privileged role of EC in CMV dissemination and challenge an indiscriminate applicability of the primary and secondary viremia concept of virus dissemination
Spin polarization versus lifetime effects at point contacts between superconducting niobium and normal metals
Point-contact Andreev reflection spectroscopy is used to measure the spin
polarization of metals but analysis of the spectra has encountered a number of
serious challenges, one of which is the difficulty to distinguish the effects
of spin polarization from those of the finite lifetime of Cooper pairs. We have
recently confirmed the polarization-lifetime ambiguity for Nb-Co and Nb-Cu
contacts and suggested to use Fermi surface mismatch, the normal reflection due
to the difference of Fermi wave vectors of the two electrodes, to solve this
dilemma. Here we present further experiments on contacts between
superconducting Nb and the ferromagnets Fe and Ni as well as the noble metals
Ag and Pt that support our previous results. Our data indicate that the Nb -
normal metal interfaces have a transparency of up to about 80 per cent and a
small, if not negligible, spin polarization.Comment: 7 pages, 2 figures, submitted to Proceedings of the 26th Conference
on Low Temperature Physic
Results from PAMELA, ATIC and FERMI : Pulsars or Dark Matter ?
It is well known that the dark matter dominates the dynamics of galaxies and
clusters of galaxies. Its constituents remain a mystery despite an assiduous
search for them over the past three decades. Recent results from the
satellite-based PAMELA experiment detect an excess in the positron fraction at
energies between 10-100 GeV in the secondary cosmic ray spectrum. Other
experiments namely ATIC, HESS and FERMI show an excess in the total electron
(\ps + \el) spectrum for energies greater 100 GeV. These excesses in the
positron fraction as well as the electron spectrum could arise in local
astrophysical processes like pulsars, or can be attributed to the annihilation
of the dark matter particles. The second possibility gives clues to the
possible candidates for the dark matter in galaxies and other astrophysical
systems. In this article, we give a report of these exciting developments.Comment: 27 Pages, extensively revised and significantly extended, to appear
in Pramana as topical revie
Higher-order multipole amplitudes in charmonium radiative transitions
Using 24 million decays in CLEO-c, we have searched
for higher multipole admixtures in electric-dipole-dominated radiative
transitions in charmonia. We find good agreement between our data and
theoretical predictions for magnetic quadrupole (M2) amplitudes in the
transitions and ,
in striking contrast to some previous measurements. Let and
denote the normalized M2 amplitudes in the respective aforementioned decays,
where the superscript refers to the angular momentum of the . By
performing unbinned maximum likelihood fits to full five-parameter angular
distributions, we determine the ratios and , where
the theoretical predictions are independent of the charmed quark magnetic
moment and are and .Comment: 32 pages, 7 figures, acceptance updat
Dalitz Plot Analysis of Ds to K+K-pi+
We perform a Dalitz plot analysis of the decay Ds to K+K-pi+ with the CLEO-c
data set of 586/pb of e+e- collisions accumulated at sqrt(s) = 4.17 GeV. This
corresponds to about 0.57 million D_s+D_s(*)- pairs from which we select 14400
candidates with a background of roughly 15%. In contrast to previous
measurements we find good agreement with our data only by including an
additional f_0(1370)pi+ contribution. We measure the magnitude, phase, and fit
fraction of K*(892) K+, phi(1020)pi+, K0*(1430)K+, f_0(980)pi+, f_0(1710)pi+,
and f_0(1370)pi+ contributions and limit the possible contributions of other KK
and Kpi resonances that could appear in this decay.Comment: 21 Pages,available through http://www.lns.cornell.edu/public/CLNS/,
submitted to PR
Search for D0 to p e- and D0 to pbar e+
Using data recorded by CLEO-c detector at CESR, we search for simultaneous
baryon and lepton number violating decays of the D^0 meson, specifically, D^0
--> p-bar e^+, D^0-bar --> p-bar e^+, D^0 --> p e^- and D^0-bar --> p e^-. We
set the following branching fraction upper limits: D^0 --> p-bar e^+ (D^0-bar
--> p-bar e^+) p e^- (D^0-bar --> p e^-) < 1.2 *
10^{-5}, both at 90% confidence level.Comment: 10 pages, available through http://www.lns.cornell.edu/public/CLNS/,
submitted to PRD. Comments: changed abstract, added reference for section 1,
vertical axis in Fig.5 changed (starts from 1.5 rather than 2.0), fixed typo
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