629 research outputs found

    Bounds on 10th moments of (x, x^3) for ellipsephic sets

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    Let A be an ellipsephic set which satis es digital restrictions in a given base. Using the method developed by Hughes and Wooley, we bound the number of integer solutions to the system of equations X2 i=1 x3i y3 i = X5 i=3 x3i y3 i X2 i=1 (xi yi) = X5 i=3 (xi yi); with x; y 2 A5. The fact that ellipsephic sets with small digit sumsets have fewer solutions of linear equations allows us to improve the general bounds obtained by Hughes andWooley and also the corresponding e cient congruencing estimates. We also generalize our result from the curve (x; x3) to (x; (x)), where is a polynomial with integer coe cients and deg( ) 3.NSF DMS Grant || NSERC Discovery Grant

    Rates and predictors of risk of stroke and its subtypes in diabetes: a prospective observational study

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    Background Small vessel disease is reported to be a more common cause of ischaemic stroke in people with diabetes than in others. However, population based studies have shown no difference between those with and those without diabetes in the subtypes of stroke. We determined the rates and predictors of risk of stroke and its subtypes in the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) trial. Methods 9795 patients aged 50–75 years with type 2 diabetes were followed up for a median of 5 years. Annual rates were derived by the Kaplan–Meier method and independent predictors of risk by Cox proportional hazards regression analyses. Results The annual rate of stroke was 6.7 per 1000 person years; 82% were ischaemic and caused by small artery disease (36%), large artery disease (17%) and embolism from the heart (13%); 10% were haemorrhagic. Among the strongest baseline predictors of ischaemic or unknown stroke were age (60–65 years, HR 1.98; >65 years, HR 2.35) and a history of stroke or transient ischaemic attack (TIA) (HR 2.06). Other independent baseline predictors were male sex, smoking, history of hypertension, ischaemic heart disease, nephropathy, systolic blood pressure and blood low density lipoprotein (LDL) cholesterol, HbA1c and fibrinogen. A history of peripheral vascular disease, low high density lipoprotein, age and history of hypertension were associated with large artery ischaemic stroke. A history of diabetic retinopathy, LDL cholesterol, male sex, systolic blood pressure, smoking, diabetes duration and a history of stroke or TIA were associated with small artery ischaemic stroke. Conclusions Older people with a history of stroke were at highest risk of stroke, but the prognosis and prognostic factors of subtypes were heterogeneous. The results will help clinicians quantify the absolute risk of stroke and its subtypes for typical diabetes patients.FIELD trial sponsored by Laboratoires Fournier SA, Dijon, France (part of Abbott

    Re‐animation and rehabilitation of the paralyzed face in head and neck cancer patients

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    Facial nerve paralysis can occasionally result from the treatment of head and neck cancer. The treatment of paralysis is patient specific, and requires an assessment of the remaining nerve segments, musculature, functional deficits, anticipated recovery, and patient factors. When feasible, reinnervation of the remaining musculature can provide the most natural outcome. However, the complex and topographic nature of facial innervation often prevents complete and meaningful movement. In these instances, a wide variety of procedures can be used to combat the functional and cosmetic sequella of facial paralysis. Clin. Anat. 25:99–107, 2012. © 2011 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/89486/1/21286_ftp.pd

    On the determination of a cloud condensation nuclei from satellite : Challenges and possibilities

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    We use aerosol size distributions measured in the size range from 0.01 to 10+ Όm during Transport and Chemical Evolution over the Pacific (TRACE-P) and Aerosol Characterization Experiment-Asia (ACE-Asia), results of chemical analysis, measured/modeled humidity growth, and stratification by air mass types to explore correlations between aerosol optical parameters and aerosol number concentration. Size distributions allow us to integrate aerosol number over any size range expected to be effective cloud condensation nuclei (CCN) and to provide definition of a proxy for CCN (CCNproxy). Because of the internally mixed nature of most accumulation mode aerosol and the relationship between their measured volatility and solubility, this CCNproxy can be linked to the optical properties of these size distributions at ambient conditions. This allows examination of the relationship between CCNproxy and the aerosol spectral radiances detected by satellites. Relative increases in coarse aerosol (e.g., dust) generally add only a few particles to effective CCN but significantly increase the scattering detected by satellite and drive the Angstrom exponent (α) toward zero. This has prompted the use of a so-called aerosol index (AI) on the basis of the product of the aerosol optical depth and the nondimensional α, both of which can be inferred from satellite observations. This approach biases the AI to be closer to scattering values generated by particles in the accumulation mode that dominate particle number and is therefore dominated by sizes commonly effective as CCN. Our measurements demonstrate that AI does not generally relate well to a measured proxy for CCN unless the data are suitably stratified. Multiple layers, complex humidity profiles, dust with very low α mixed with pollution, and size distribution differences in pollution and biomass emissions appear to contribute most to method limitations. However, we demonstrate that these characteristic differences result in predictable influences on AI. These results suggest that inference of CCN from satellites will be challenging, but new satellite and model capabilities could possibly be integrated to improve this retrieval

    Sensory Neuron-Specific GPCR Mrgprs Are Itch Receptors Mediating Chloroquine-Induced Pruritus

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    The cellular and molecular mechanisms mediating histamine-independent itch in primary sensory neurons are largely unknown. Itch induced by chloroquine (CQ) is a common side effect of this widely used antimalarial drug. Here, we show that Mrgprs, a family of G protein-coupled receptors expressed exclusively in peripheral sensory neurons, function as itch receptors. Mice lacking a cluster of Mrgpr genes display significant deficits in itch induced by CQ but not histamine. CQ directly excites sensory neurons in an Mrgpr-dependent manner. CQ specifically activates mouse MrgprA3 and human MrgprX1. Loss- and gain-of-function studies demonstrate that MrgprA3 is required for CQ responsiveness in mice. Furthermore, MrgprA3-expressing neurons respond to histamine and coexpress gastrin-releasing peptide, a peptide involved in itch sensation, and MrgprC11. Activation of these neurons with the MrgprC11-specific agonist BAM8-22 induces itch in wild-type but not mutant mice. Therefore, Mrgprs may provide molecular access to itch-selective neurons and constitute novel targets for itch therapeutics

    Quantitative analysis of powder mixtures by raman spectrometry : the influence of particle size and its correction

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    Particle size distribution and compactness have significant confounding effects on Raman signals of powder mixtures, which cannot be effectively modeled or corrected by traditional multivariate linear calibration methods such as partial least-squares (PLS), and therefore greatly deteriorate the predictive abilities of Raman calibration models for powder mixtures. The ability to obtain directly quantitative information from Raman signals of powder mixtures with varying particle size distribution and compactness is, therefore, of considerable interest In this study, an advanced quantitative Raman calibration model was developed to explicitly account for the confounding effects of particle size distribution and compactness on Raman signals of powder mixtures. Under the theoretical guidance of the proposed Raman calibration model, an advanced dual calibration strategy was adopted to separate the Raman contributions caused by the changes in mass fractions of the constituents in powder mixtures from those induced by the variations in the physical properties of samples, and hence achieve accurate quantitative determination for powder mixture samples. The proposed Raman calibration model was applied to the quantitative analysis of backscatter Raman measurements of a proof-of-concept model system of powder mixtures consisting of barium nitrate and potassium chromate. The average relative prediction error of prediction obtained by the proposed Raman calibration model was less than one-third of the corresponding value of the best performing PLS model for mass fractions of barium nitrate in powder mixtures with variations in particle size distribution, as well as compactness

    In situ measurements of water uptake by black carbon-containing aerosol in wildfire plumes

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    Water uptake by black carbon (BC)-containing aerosol was quantified in North American wildfire plumes of varying age (1 to ~40 h old) sampled during the SEAC4RS mission (2013). A Humidified Dual SP2 (HD-SP2) is used to optically size BC-containing particles under dry and humid conditions from which we extract the hygroscopicity parameter, Îș, of materials internally mixed with BC. Instrumental variability and the uncertainty of the technique are briefly discussed. An ensemble average Îș of 0.04 is found for the set of plumes sampled, consistent with previous estimates of bulk aerosol hygroscopicity from biomass burning sources. The temporal evolution of Îș in the Yosemite Rim Fire plume is explored to constrain the rate of conversion of BC-containing aerosol from hydrophobic to more hydrophilic modes in these emissions. A BC-specific Îș increase of ~0.06 over 40 h is found, fit well with an exponential curve corresponding to a transition from a Îș of 0 to a Îș of ~0.09 with an e-folding time of 29 h. Although only a few percent of wildfire particles contain BC, a similar Îș increase is estimated for bulk aerosol and the measured aerosol composition is used to infer that the observed Îș change is driven by a combination of incorporation of ammonium sulfate and oxidation of existing organic materials. Finally, a substantial fraction of wildfire-generated BC-containing aerosol is calculated to be active as cloud condensation nuclei shortly after emission likely indicating efficient wet removal. These results can constrain model treatment of BC from wildfire sources

    Stochastic Gravity: Theory and Applications

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    Whereas semiclassical gravity is based on the semiclassical Einstein equation with sources given by the expectation value of the stress-energy tensor of quantum fields, stochastic semiclassical gravity is based on the Einstein-Langevin equation, which has in addition sources due to the noise kernel.In the first part, we describe the fundamentals of this new theory via two approaches: the axiomatic and the functional. In the second part, we describe three applications of stochastic gravity theory. First, we consider metric perturbations in a Minkowski spacetime: we compute the two-point correlation functions for the linearized Einstein tensor and for the metric perturbations. Second, we discuss structure formation from the stochastic gravity viewpoint. Third, we discuss the backreaction of Hawking radiation in the gravitational background of a quasi-static black hole.Comment: 75 pages, no figures, submitted to Living Reviews in Relativit

    High light and temperature reduce photosynthetic efficiency through different mechanisms in the C4 model Setaria viridis.

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    Funder: start-up funding from Donald Danforth Plant Science CenterC4 plants frequently experience high light and high temperature conditions in the field, which reduce growth and yield. However, the mechanisms underlying these stress responses in C4 plants have been under-explored, especially the coordination between mesophyll (M) and bundle sheath (BS) cells. We investigated how the C4 model plant Setaria viridis responded to a four-hour high light or high temperature treatment at photosynthetic, transcriptomic, and ultrastructural levels. Although we observed a comparable reduction of photosynthetic efficiency in high light or high temperature treated leaves, detailed analysis of multi-level responses revealed important differences in key pathways and M/BS specificity responding to high light and high temperature. We provide a systematic analysis of high light and high temperature responses in S. viridis, reveal different acclimation strategies to these two stresses in C4 plants, discover unique light/temperature responses in C4 plants in comparison to C3 plants, and identify potential targets to improve abiotic stress tolerance in C4 crops
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