2,443,897 research outputs found
Departure from the onset-onset rule
Using a signal-detection task, the generality of Turvey's (1973) onset-onset rule was tested in four experiments. After seeing, in succession, (1) one or two letters (target display), (2) a multiletter detection display, and (3) a mask display, subjects decided whether or not the letter or letters in the target display reappeared in the succeeding detection display at different levels of detection-display duration in various situations. The subjects' sensitivity was inconsistent with the onset-onset rule. More specifically, sensitivity increased with increases in display duration within a fixed stimulus onset asynchrony of 150 msec. Display duration, however, had no effect on response bias. Nor was there any interaction between display duration and display size in terms of either sensitivity or response bias. The more complicated relationship between display duration and display size does not invalidate the departure from the onset-onset rule
Onset of entanglement
We have developed a theory of polymer entanglement using an extended
Cahn-Hilliard functional, with two extra terms. One is a nonlocal attractive
term, operating over mesoscales, which is interpreted as giving rise to
entanglement, and the other a local repulsive term indicative of excluded
volume interactions. We show how such a functional can be derived using notions
from gauge theory. We go beyond the Gaussian approximation, to the one-loop
level, to show that the system exhibits a crossover to a state of entanglement
as the average chain length between points of entanglement decreases. This
crossover is marked by critical slowing down, as the effective diffusion
constant goes to zero. We have also computed the tensile modulus of the system,
and we find a corresponding crossover to a regime of high modulus.Comment: 18 pages, with 4 figure
Generalized synchronization onset
The behavior of two unidirectionally coupled chaotic oscillators near the
generalized synchronization onset has been considered. The character of the
boundaries of the generalized synchronization regime has been explained by
means of the modified systemComment: 7 pages, 3 figure
Fluidity Onset in Graphene
Viscous electron fluids have emerged recently as a new paradigm of
strongly-correlated electron transport in solids. Here we report on a direct
observation of the transition to this long-sought-for state of matter in a
high-mobility electron system in graphene. Unexpectedly, the electron flow is
found to be interaction-dominated but non-hydrodynamic (quasiballistic) in a
wide temperature range, showing signatures of viscous flows only at relatively
high temperatures. The transition between the two regimes is characterized by a
sharp maximum of negative resistance, probed in proximity to the current
injector. The resistance decreases as the system goes deeper into the
hydrodynamic regime. In a perfect darkness-before-daybreak manner, the
interaction-dominated negative response is strongest at the transition to the
quasiballistic regime. Our work provides the first demonstration of how the
viscous fluid behavior emerges in an interacting electron system.Comment: 8pgs, 4fg
The role of 39 psoriasis risk variants on age of psoriasis onset.
Recent genome-wide association studies (GWAS) have identified multiple genetic risk factors for psoriasis, but data on their association with age of onset have been marginally explored. The goal of this study was to evaluate known risk alleles of psoriasis for association with age of psoriasis onset in three well-defined case-only cohorts totaling 1,498 psoriasis patients. We selected 39 genetic variants from psoriasis GWAS and tested these variants for association with age of psoriasis onset in a meta-analysis. We found that rs10484554 and rs12191877 near HLA-C and rs17716942 near IFIH1 were associated with age of psoriasis onset with false discovery rate < 0.05. The association between rs17716942 and age of onset was not replicated in a fourth independent cohort of 489 patients (P = 0.94). The imputed HLA-C∗06:02 allele demonstrated a much stronger association with age of psoriasis onset than rs10484554 and rs12191877. We conclude that despite the discovery of numerous psoriasis risk alleles, HLA-C∗06:02 still plays the most important role in determining the age of onset of psoriasis. Larger studies are needed to evaluate the contribution of other risk alleles, including IFIH1, to age of psoriasis onset
Late onset of Huntington's disease
Twenty-five patients with late-onset Huntington's disease were studied; motor impairment appeared at age 50 years or later. The average age at onset of chorea was 57.5 years, with an average age at diagnosis of 63.1 years. Approximately 25% of persons affected by Huntington's disease exhibit late onset. A preponderance of maternal transmission was noted in late-onset Huntington's disease. The clinical features resembled those of mid-life onset Huntington's disease but progressed more slowly. Neuropathological evaluation of two cases reveal less severe neuronal atrophy than for mid-life onset disease
Temporal discrimination: Mechanisms and relevance to adult-onset dystonia
Temporal discrimination is the ability to determine that two sequential sensory stimuli are separated in time. For any individual, the temporal discrimination threshold (TDT) is the minimum interval at which paired sequential stimuli are perceived as being asynchronous; this can be assessed, with high test-retest and inter-rater reliability, using a simple psychophysical test. Temporal discrimination is disordered in a number of basal ganglia diseases including adult-onset dystonia, of which the two most common phenotypes are cervical dystonia and blepharospasm. The causes of adult-onset focal dystonia are unknown; genetic, epigenetic, and environmental factors are relevant. Abnormal TDTs in adult-onset dystonia are associated with structural and neurophysiological changes considered to reflect defective inhibitory interneuronal processing within a network which includes the superior colliculus, basal ganglia, and primary somatosensory cortex. It is hypothesized that abnormal temporal discrimination is a mediational endophenotype and, when present in unaffected relatives of patients with adult-onset dystonia, indicates non-manifesting gene carriage. Using the mediational endophenotype concept, etiological factors in adult-onset dystonia may be examined including (i) the role of environmental exposures in disease penetrance and expression; (ii) sexual dimorphism in sex ratios at age of onset; (iii) the pathogenesis of non-motor symptoms of adult-onset dystonia; and (iv) subcortical mechanisms in disease pathogenesis
Reslizumab in patients with inadequately controlled late-onset asthma and elevated blood eosinophils
INTRODUCTION: Asthma with adult onset and elevated blood eosinophils is a difficult-to-treat subgroup. This post hoc analysis evaluated reslizumab, an anti-interleukin-5 monoclonal antibody, in patients with late-onset eosinophilic asthma.
METHODS: Data from two 52-week placebo-controlled trials of reslizumab IV 3 mg/kg every 4 weeks in patients aged 12-75 years with inadequately controlled asthma, ≥1 asthma exacerbation within 12 months, and screening blood eosinophils ≥400/μL (NCT01287039/NCT01285323) were stratified by age of asthma onset (<40 or ≥40 years). Annual clinical asthma exacerbation rates, change in lung function, and patient-reported outcomes were analyzed.
RESULTS: 273 patients with late-onset asthma (placebo, n = 130; reslizumab, n = 143) and 658 with early-onset asthma (placebo, n = 336; reslizumab, n = 322) were included. Baseline demographics were similar between groups. The interaction between age at onset of asthma and effect of reslizumab on asthma exacerbations was statistically significant (p = 0.0083). Compared with placebo, reslizumab produced a 75% relative reduction in asthma exacerbations in patients with late-onset asthma (rate ratio [RR] 0.25; 95% confidence interval [CI], 0.16, 0.40), substantially larger than the reduction in earlier onset patients (RR 0.58; 95% CI, 0.44, 0.76). Similar findings were observed for other measures of asthma, including forced expiratory volume in 1 s (FEV1). The adverse event profile of reslizumab was similar in patients with early- or late-onset asthma.
CONCLUSIONS: Compared with placebo, reslizumab produced larger reductions in asthma exacerbations and larger improvements in lung function in patients with late versus early-onset asthma
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