4,870 research outputs found

    Dip-coating of suspensions

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    Withdrawing a plate from a suspension leads to the entrainment of a coating layer of fluid and particles on the solid surface. In this article, we study the Landau-Levich problem in the case of a suspension of non-Brownian particles at moderate volume fraction 10%<ϕ<41%10\% < \phi < 41\%. We observe different regimes depending on the withdrawal velocity UU, the volume fraction of the suspension ϕ\phi, and the diameter of the particles 2a2\,a. Our results exhibit three coating regimes. (i) At small enough capillary number CaCa, no particles are entrained, and only a liquid film coats the plate. (ii) At large capillary number, we observe that the thickness of the entrained film of suspension is captured by the Landau-Levich law using the effective viscosity of the suspension η(ϕ)\eta(\phi). (iii) At intermediate capillary numbers, the situation becomes more complicated with a heterogeneous coating on the substrate. We rationalize our experimental findings by providing the domain of existence of these three regimes as a function of the fluid and particles properties

    Paleo- stress and strain rates in an intra-arc strike-slip fault, Sierra Nevada, California

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    Structures and microstructures of the Proto-Kern Canyon fault (PKCF), a 130-km-long dextral strike-slip shear zone of the southern Sierra Nevada batholith, provide constraints on displacement, flow stress, and strain rate during arc formation. Shear strain analyses of S-C mylonites indicate ~5 km of ductile dextral slip along the PKCF. But field mapping and measurements of individual plutons and metamorphic pendants show these bodies have much more elongated aspect ratios, of up to 1:17, within the shear zone than outside of it. This suggests significantly higher strain and dextral slip of up to 15 km along the highest-strain zone of the PKCF. Petrographic observations of high-strain igneous rocks near Lake Isabella indicate that deformation started at temperatures of 400-450° C and continued through cooling to ~300° C. Based on ^(40)Ar/^(39)Ar dating of hornblende, mica, and K-feldspar, early cooling (~20° C/m.y.) from 88-70 Ma was followed by very slow cooling (~1° C/m.y.). These data, combined with cross-cutting relationships, suggest that dextral ductile shear was active from 90-86 Ma. Grain sizes of dynamically recrystallized pure quartz mylonites in this part of the shear zone were used to estimate flow stresses of 20-40 MPa. Applying mylonitization temperature estimates of 400-350° C and lithostatic pressures of 350- 400 MPa (from Al-in-hbl barometry) yields paleo-strain rates along the PKCF of 10^(-13)-10^(-15) /s. Additional quartzite piezometry, as well as calcite piezometry on marble mylonites, should provide further constraints on stress and strain rates along the length and depth exposures of this intrabatholithic shear zone

    The association between neuroticism and self-reported common somatic symptoms in a population cohort

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    OBJECTIVE: To test the hypotheses that (1) neuroticism is associated with self-reported somatic symptoms; (2) this association is especially found with regard to psychosomatic symptoms; and (3) it is not solemnly explained by somatic reflections of psychological distress. METHODS: We studied the cross-sectional association between neuroticism (as measured by EPQ-RSS-N), psychological distress (as measured by GHQ-12 sum score), and the occurrence of 22 common somatic symptoms by linear and logistic regression analyses in a population cohort of 6894 participants. RESULTS: Neuroticism is more strongly associated with the total number of somatic symptoms reported (beta=.32) than GHQ-12 sum score (beta=.15) and well-established risk markers such as gender (beta=.11) and age (beta=.04). Neuroticism was associated with all symptoms in individual logistic regressions controlled for age, gender, and psychological distress. Neuroticism is significantly more strongly related to psychosomatic symptoms (beta=.36) than to infectious/allergic symptoms (beta=.28). CONCLUSION: In a large, population-based cohort, we confirmed that neuroticism is associated with self-reported somatic symptoms. The associations were not attributable to somatic reflections of psychological distress associated with neuroticism and were relatively strong with respect to psychosomatic symptoms. Future studies should include both objective and subjective measures of health to study the mechanisms that connect neuroticism and ill health

    Photoionization spectroscopy of CH3C3N in the vacuum-ultraviolet range

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    International audienceUsing vacuum-ultraviolet (VUV) synchrotron radiation, threshold and dissociative photoionization of cyanopropyne (CH3C3N) in the gas phase have been studied from 86 000 cm−1 up to 180 000 cm−1 by recording Threshold-PhotoElectron Spectrum (TPES) and PhotoIon Yield (PIY). Ionization energies of the four lowest electronic states X̃+2E,Ã+2A1,B̃+2E and C̃+ of CH3C3N+ are derived from the TPES with a better accuracy than previously reported. The adiabatic ionization potential of CH3C3N is measured as 86872±20 cm−1. A description of the vibrational structure of these states is proposed leading to the first determination of the vibrational frequencies for most modes. The vibrational assignments of the X̃+ state are supported by density functional theory calculations. In addition, dissociative photoionization spectra have been recorded for several cationic fragments in the range 12–15.5 eV (96 790–125 000 cm−1) and they bring new information on the photophysics of CH3C3N+. Threshold energies for the cationic dissociative channels leading to CH2C3N+, CHC3N+, HC3H+, HCNH+ and CH3+ have been measured for the first time and are compared with quantum chemical calculations

    Limited effect of patient and disease characteristics on compliance with hospital antimicrobial guidelines

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    Objective: Physicians frequently deviate from guidelines that promote prudent use of antimicrobials. We explored to what extent patient and disease characteristics were associated with compliance with guideline recommendations for three common infections. Methods: In a 1-year prospective observational study, 1,125 antimicrobial prescriptions were analysed for compliance with university hospital guidelines. Results: Compliance varied significantly between and within the groups of infections studied. Compliance was much higher for lower respiratory tract infections (LRTIs; 79%) than for sepsis (53%) and urinary tract infections (UTIs; 40%). Only predisposing illnesses and active malignancies were associated with more compliant prescribing, whereas alcohol/ intravenous drug abuse and serum creatinine levels > 130 mu mol/l were associated with less compliant prescribing. Availability of culture results had no impact on compliance with guidelines for sepsis but was associated with more compliance in UTIs and less in LRTIs. Narrowing initial broad-spectrum antimicrobial therapy to cultured pathogens was seldom practised. Most noncompliant prescribing concerned a too broad spectrum of activity when compared with guideline-recommended therapy. Conclusion: Patient characteristics had only a limited impact on compliant prescribing for a variety of reasons. Physicians seemed to practise defensive prescribing behaviour, favouring treatment success in current patients over loss of effectiveness due to resistance in future patients

    Sex differences in the association between plasma copeptin and incident type 2 diabetes: the Prevention of Renal and Vascular Endstage Disease (PREVEND) study

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    AIMS/HYPOTHESIS: Vasopressin plays a role in osmoregulation, glucose homeostasis and inflammation. Therefore, plasma copeptin, the stable C-terminal portion of the precursor of vasopressin, has strong potential as a biomarker for the cardiometabolic syndrome and diabetes. Previous results were contradictory, which may be explained by differences between men and women in responsiveness of the vasopressin system. The aim of this study was to evaluate the usefulness of copeptin for prediction of future type 2 diabetes in men and women separately. METHODS: From the Prevention of Renal and Vascular Endstage Disease (PREVEND) study, 4,063 women and 3,909 men without diabetes at baseline were included. A total of 208 women and 288 men developed diabetes during a median follow-up of 7.7 years. RESULTS: In multivariable-adjusted models, we observed a stronger association of copeptin with risk of future diabetes in women (OR 1.49 [95% CI 1.24, 1.79]) than in men (OR 1.01 [95% CI 0.85, 1.19]) (p (interaction) < 0.01). The addition of copeptin to the Data from the Epidemiological Study on the Insulin Resistance Syndrome (DESIR) clinical model improved the discriminative value (C-statistic,+0.007, p = 0.02) and reclassification (integrated discrimination improvement [IDI] = 0.004, p < 0.01) in women. However, we observed no improvement in men. The additive value of copeptin in women was maintained when other independent predictors, such as glucose, high sensitivity C-reactive protein (hs-CRP) and 24 h urinary albumin excretion (UAE), were included in the model. CONCLUSIONS/INTERPRETATION: The association of plasma copeptin with the risk of developing diabetes was stronger in women than in men. Plasma copeptin alone, and along with existing biomarkers (glucose, hs-CRP and UAE), significantly improved the risk prediction for diabetes in women

    Substantiating a political public sphere in the Scottish press : a comparative analysis

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    This article uses content analysis to characterize the performance of the media in a national public sphere, by setting apart those qualities that typify internal press coverage of a political event. The article looks at the coverage of the 1999 devolved Scottish election from the day before the election until the day after. It uses a word count to measure the election material in Scottish newspapers the Herald, the Press and Journal and the Scotsman, and United Kingdom newspapers the Guardian, the Independent and The Times, and categorizes that material according to discourse type, day and page selection. The article finds a number of qualities that typify the Scottish sample in particular, and might be broadly indicative of a political public sphere in action. Firstly, and not unexpectedly, it finds that the Scottish newspapers carry significantly more election coverage. Just as tellingly, though, the article finds that the Scottish papers offer a greater proportion of advice and background information, in the form of opinion columns and feature articles. It also finds that the Scottish papers place a greater concentration of both informative and evaluative material in the period before the vote, consistent with their making a contribution to informed political action. Lastly, the article finds that the Scottish sample situates coverage nearer the front of the paper and places a greater proportion on recto pages. The article therefore argues that the Scottish papers display features that distinguish them from the UK papers, and are broadly consistent with their forming part of a deliberative public sphere, and suggests that these qualities might be explored as a means of judging future media performance

    Comparing international coverage of 9/11 : towards an interdisciplinary explanation of the construction of news

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    This article presents an interdisciplinary model attempting to explain how news is constructed by relying on the contributions of different fields of study: News Sociology, Political Communications, International Communications, International Relations. It is a first step towards developing a holistic theoretical approach to what shapes the news, which bridges current micro to macro approaches. More precisely the model explains news variation across different media organization and countries by focusing on the different way the sense of newsworthiness of journalists is affected by three main variables: national interest, national journalistic culture, and editorial policy of each media organization. The model is developed on the basis of an investigation into what shaped the media coverage of 9/11 in eight elite newspapers across the US, France, Italy and Pakistan
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