9,947 research outputs found

    An examination of persistence in charitable giving to education through the 2002 economic downturn

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    Using three waves of the Center on Philanthropy Panel Study, a module of the Panel Study of Income Dynamics, ïŹ elded by the Institute for Social Research at the University of Michigan, we examine characteristics of donors who gave to any level of education in each of the years studied (2000, 2002 and 2004). We ïŹ nd that these persistent donors to education are more likely to have higher income (average of US $ 142 603 in 2000) and higher levels of education (bachelor ’ s degree or above) than are less frequent education donors and non-donors to education. There is some support for a positive association between persistent giving to education and the number and age of children in the household. There is strong support for positive association between educational attainment and persistence in giving to education and in giving to other secular causes. Implications for fundraising practice and further research topics are discussed

    How to improve poor system efficiencies of ESP installations controlled by surface chokes

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    Influence of post-stroke fatigue on reaction times and corticospinal excitability during movement preparation

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    OBJECTIVES: Reduced corticospinal excitability at rest is associated with post-stroke fatigue (PSF). However, it is not known if corticospinal excitability prior to a movement is also altered in fatigue which may then influence subsequent behaviour. We hypothesized that the levels of PSF can be explained by differences in modulation of corticospinal excitability during movement preparation. METHODS: 73 stroke survivors performed an auditory reaction time task. Corticospinal excitability was measured using transcranial magnetic stimulation. Fatigue was quantified using the fatigue severity scale. The effect of time and fatigue on corticospinal excitability and reaction time was analysed using a mixed effects model. RESULTS: Those with greater levels of PSF showed reduced suppression of corticospinal excitability during movement preparation and increased facilitation immediately prior to movement onset (ÎČ = -0.0066, t = -2.22, p = 0.0263). Greater the fatigue, slower the reaction times the closer the stimulation time to movement onset (ÎČ = 0.0024, t = 2.47, p = 0.0159). CONCLUSIONS: Lack of pre-movement modulation of corticospinal excitability in high fatigue may indicate poor sensory processing supporting the sensory attenuation model of fatigue. SIGNIFICANCE: We take a systems-based approach and investigate the motor system and its role in pathological fatigue allowing us to move towards gaining a mechanistic understanding of chronic pathological fatigue

    Fatal disseminated varicella zoster infection following zoster vaccination in an immunocompromised patient

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    A 79-year-old man with chronic lymphocytic leukaemia presented with fever and a widespread vesicular rash on 19 November 2014. The patient had not been under immunosuppressive regime for 6 months. He had received a shingles vaccine on 14th October and developed flu-like symptoms after 2 weeks. Intravenous antimicrobial therapy including aciclovir was started. He remained stable with no evidence of systemic involvement. On day 5, he developed respiratory and renal failure that required transfer to intensive care unit. Vesicle fluid, bronchoalveolar lavage and plasma were positive for varicella zoster virus by PCR. Slight clinical improvement allowed extubation on day 16. He subsequently deteriorated and died on day 25. Multiorgan failure was considered the immediate cause of death whereas disseminated varicella zoster infection was stated in the medical certificate as the other condition leading to this outcome. Varicella zoster Oka vaccine strain was detected in vesicle fluid, using PCR

    Assessing the Risk of Metals and Their Mixtures in the Antarctic Nearshore Marine Environment with Diffusive Gradients in Thin-Films

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    © 2019 American Chemical Society. Robust environmental assessments and contaminant monitoring in Antarctic near-shore marine environments need new techniques to overcome challenges presented by a highly dynamic environment. This study outlines an approach for contaminant monitoring and risk assessment in Antarctic marine conditions using diffusive gradients in thin-films (DGT) coupled to regionally specific ecotoxicology data and environmental quality standards. This is demonstrated in a field study where DGT samplers were deployed in the near-shore marine environment of East Antarctica around the operational Casey station and the abandoned Wilkes station to measure the time-averaged biologically available fraction of metal contaminants. The incorporation of DGT-labile concentrations to reference toxicity mixture models for three Antarctic organisms predicted low toxic effects (<5% effect to the growth or development of each organism). The comparison of metal concentrations to the Australian and New Zealand default water quality guideline values (WQGVs) showed no marine site exceeding the WQGVs for 95% species protection. However, all sites exceeded the 99% WQGVs due to copper concentrations that are likely of geogenic origin (i.e., not from anthropogenic sources). This study provides evidence supporting the use of the DGT technique to monitor contaminants and assess their environmental risk in the near-shore marine environment of Antarctica

    Search for Bc(ns)B_c(ns) via the Bc(ns)→Bc(ms)π+π−B_c(ns)\to B_c(ms)\pi^+\pi^- transition at LHCb and Z0Z_0 factory

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    It is interesting to study the characteristics of the whole family of BcB_c which contains two different heavy flavors. LHC and the proposed Z0Z^0 factory provide an opportunity because a large database on the BcB_c family will be achieved. BcB_c and its excited states can be identified via their decay modes. As suggested by experimentalists, Bc∗(ns)→Bc+ÎłB_c^*(ns)\to B_c+\gamma is not easy to be clearly measured, instead, the trajectories of π+\pi^+ and π−\pi^- occurring in the decay of Bc(ns)→Bc(ms)+π+π−B_c(ns)\to B_c(ms)+\pi^+\pi^- (n>mn>m) can be unambiguously identified, thus the measurement seems easier and more reliable, therefore this mode is more favorable at early running stage of LHCb and the proposed Z0Z^0 factory. In this work, we calculate the rate of Bc(ns)→Bc(ms)+π+π−B_c(ns)\to B_c(ms)+\pi^+\pi^- in terms of the QCD multipole-expansion and the numerical results indicate that the experimental measurements with the luminosity of LHC and Z0Z^0 factory are feasible.Comment: 12 pages, 1 figures and 4 tables, acceptted by SCIENCE CHINA Physics, Mechanics & Astronomy (Science in China Series G

    Ion‐Specific Oil Repellency of Polyelectrolyte Multilayers in Water: Molecular Insights into the Hydrophilicity of Charged Surfaces

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    Surface wetting on polyelectrolyte multilayers (PEMs), prepared by alternating deposition of polydiallyldimethylammonium chloride (PDDA) and poly(styrene sulfonate) (PSS), was investigated mainly in water‐solid‐oil systems. The surface‐wetting behavior of as‐prepared PEMs was well correlated to the molecular structures of the uncompensated ionic groups on the PEMs as revealed by sum frequency generation vibrational and X‐ray photoelectron spectroscopies. The orientation change of the benzenesulfonate groups on the PSS‐capped surfaces causes poor water wetting in oil or air and negligible oil wetting in water, while the orientation change of the quaternized pyrrolidine rings on the PDDA‐capped surfaces hardly affects their wetting behavior. The underwater oil repellency of PSS‐capped PEMs was successfully harnessed to manufacture highly efficient filters for oil‐water separation at high flux.Wet surfaces: Liquid wetting on charged surfaces is well correlated with the molecular nature of surface ionic groups. The orientation change of surface ionic groups either hardly affects water wetting if their configuration is isotropic, or markedly transforms poor water wetting in oil to poor water de‐wetting in water if their configuration is anisotropic, thus leading to excellent underwater oil repellency.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111271/1/anie_201411992_sm_miscellaneous_information.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/111271/2/4851_ftp.pd

    Angle-robust Two-Qubit Gates in a Linear Ion Crystal

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    In trapped-ion quantum computers, two-qubit entangling gates are generated by applying spin-dependent force which uses phonons to mediate interaction between the internal states of the ions. To maintain high-fidelity two-qubit gates under fluctuating experimental parameters, robust pulse-design methods are applied to remove the residual spin-motion entanglement in the presence of motional mode frequency drifts. Here we propose an improved pulse-design method that also guarantees the robustness of the two-qubit rotation angle against uniform mode frequency drifts by combining pulses with opposite sensitivity of the angle to mode frequency drifts. We experimentally measure the performance of the designed gates and see an improvement on both gate fidelity and gate performance under uniform mode frequency offsets.Comment: 10 pages, 11 figure

    Direct production of dihydroxylated sesquiterpenoids by a maize terpene synthase

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    The astounding structural and biological diversity of the large class of terpenoid natural products are imparted by both their complex hydrocarbon backbones and further elaboration by the addition of multiple hydroxyl groups, which provide both solubility and specific binding properties. While the role of terpene synthases in generating hydrocarbons with complex backbones is well known, these also are known to generate (singly) hydroxylated products by the addition of water prior to terminating deprotonation. Here a maize sesquiterpene synthase was unexpectedly found to generate dually hydroxylated products directly from (E,E)-farnesyl diphosphate, primarily eudesmane-2,11-diol, along with two closely related structural isomers. The unprecedented formation of these diols was proposed to proceed via initial addition of water to a germacradienyl+ intermediate, followed by protonation of the internal carbon-6,7-double-bond in the resulting hedycarol, with subsequent cyclization and further addition of water to an eudesmolyl+ intermediate. Evidence for the proposed mechanism was provided by labeling studies, as well as site-directed mutagenesis, based on structural modeling, which identified an active site phenylalanine required for the protonation and further elaboration of hedycaryol. This di-hydroxylated sesquiterpenoid synthase was specifically expressed in maize roots and induced by pathogen infection, with its major enzymatic product only detected in root exudates or infected roots, suggesting a role in defense. Regardless of the ultimate metabolic fate or physiological role of these diols, this report not only reveals an unanticipated extension of the catalytic prowess of terpene synthases, but also provides insight into the underlying enzymatic mechanism
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