490 research outputs found

    Solitary coherent structures in viscoelastic shear flow: computation and mechanism

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    Starting from stationary bifurcations in Couette-Dean flow, we compute nontrivial stationary solutions in inertialess viscoelastic circular Couette flow. These solutions are strongly localized vortex pairs, exist at arbitrarily large wavelengths, and show hysteresis in the Weissenberg number, similar to experimentally observed ``diwhirl'' patterns. Based on the computed velocity and stress fields, we elucidate a heuristic, fully nonlinear mechanism for these flows. We propose that these localized, fully nonlinear structures comprise fundamental building blocks for complex spatiotemporal dynamics in the flow of elastic liquids.Comment: 5 pages text and 4 figures. Submitted to Physical Review Letter

    Incompressible Turbulent Flow in a Permeable-Walled Duct

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    An analysis is made of fully developed turbulent flow in a paralle

    The 100 most eminent psychologists of the 20th century.

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    A rank-ordered list was constructed that reports the first 99 of the 100 most eminent psychologists of the 20th century. Eminence was measured by scores on 3 quantitative variables and 3 qualitative variables. The quantitative variables were journal citation frequency, introductory psychology textbook citation frequency, and survey response frequency. The qualitative variables were National Academy of Sciences membership, election as American Psychological Association (APA) president or receipt of the APA Distinguished Scientific Contributions Award, and surname used as an eponym. The qualitative variables were quantified and combined with the other 3 quantitative variables to produce a composite score that was then used to construct a rank-ordered list of the most eminent psychologists of the 20th century. The discipline of psychology underwent a remarkable transformation during the 20th cen-tury, a transformation that included a shift away from the European-influenced philosophical psychology of the late 19th century to th

    The State of Mental Health in the Mountain West

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    This fact sheet explores mental health rankings of Mountain West states from Mental Health America’s (MHA) 2022 report, The State of Mental Health in America. This study offers a snapshot of U.S. mental health based on data across all 50 states and the District of Columbia. MHA is the nation’s leading community based mental health nonprofit, founded in 1909, and “dedicated to addressing the needs of those living with mental illness and promoting the overall mental health of all.” This report is a companion to MHA’s interactive data available through its website

    Youth Mental Health in the Mountain West

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    This fact sheet explores youth mental health metrics of Mountain West states from the Hopeful Futures Campaign’s 2022 report, America’s School Mental Health Report Card. This study provides state snapshots on school mental health policies and workforce availability for all 50 states and the District of Columbia. The Mountain West states of Arizona, Colorado, Nevada, New Mexico, and Utah are considered here

    Calix[4]arene-supported rare earth octahedra

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    El pdf del artículo es la versión post-print.-- et al.A series of calix[4]arene-supported Ln III 6 clusters have been synthesised under facile bench top conditions. The magnetic and structural properties of these clusters are reported, the latter suggesting that the Ln III-calix[4]arene moiety may be used for the construction of other assemblies in a manner akin to that for the Mn III-calix[4]arene analogue. © 2012 The Royal Society of Chemistry.We thank the EP SRC for financial support of this work.Peer Reviewe

    Associations Between Air Pollution Exposure and Empirically Derived Profiles of Cognitive Performance in Older Women

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    Background:Elucidating associations between exposures to ambient air pollutants and profiles of cognitive performance may provide insight into neurotoxic effects on the aging brain. Objective:We examined associations between empirically derived profiles of cognitive performance and residential concentrations of particulate matter of aerodynamic diameter \u3c 2.5 (PM2.5) and nitrogen dioxide (NO2) in older women. Method:Women (N = 2,142) from the Women’s Health Initiative Study of Cognitive Aging completed a neuropsychological assessment measuring attention, visuospatial, language, and episodic memory abilities. Average yearly concentrations of PM2.5 and NO2 were estimated at the participant’s addresses for the 3 years prior to the assessment. Latent profile structural equation models identified subgroups of women exhibiting similar profiles across tests. Multinomial regressions examined associations between exposures and latent profile classification, controlling for covariates. Result:Five latent profiles were identified: low performance across multiple domains (poor multi-domain; n = 282;13%), relatively poor verbal episodic memory (poor memory; n = 216; 10%), average performance across all domains (average multi-domain; n = 974; 45%), superior memory (n = 381; 18%), and superior attention (n = 332; 15%). Using women with average cognitive ability as the referent, higher PM2.5 (per interquartile range [IQR] = 3.64ÎŒg/m3) was associated with greater odds of being classified in the poor memory (OR = 1.29; 95% Confidence Interval [CI] = 1.10–1.52) or superior attention (OR = 1.30; 95% CI = 1.10–1.53) profiles. NO2 (per IQR = 9.86 ppb) was associated with higher odds of being classified in the poor memory (OR = 1.38; 95% CI = 1.17–1.63) and lower odds of being classified with superior memory (OR = 0.81; 95% CI = 0.67–0.97). Conclusion:Exposure to PM2.5 and NO2 are associated with patterns of cognitive performance characterized by worse verbal episodic memory relative to performance in other domains
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