Effect of different quantities of a sugared clear fluid on gastric emptying and residual volume in children: a crossover study using magnetic resonance imaging

Background Gastric emptying in the first 2 h after 7 ml kg−1 of sugared clear fluid has recently been investigated in healthy children using magnetic resonance imaging (MRI). This study aims to compare gastric volume and emptying half-life during 1 h after 3 or 7 ml kg−1 sugared clear fluid intake. Methods Fourteen healthy volunteer children aged 11.1 (8.2-12.5) yr were investigated prospectively after administration of 3 and 7 ml kg−1 diluted raspberry syrup in a randomized order, after overnight fasting (baseline). Gastric content volume (GCVw) was assessed with a 1.5 Tesla MRI scanner in a blinded fashion. Data are presented as median (range) and compared using the Wilcoxon test. Results Baseline GCVw was 0.39 (0.04-1.00) and 0.34 (0.07-0.75) before intake of 3 and 7 ml kg−1 syrup, respectively (P=0.93). GCVw was 0.45 (0.04-1.55)/1.33 (0.30-2.60) ml kg−1 60 min after ingestion of 3/7 ml kg−1 syrup (P=0.002). Thus GCVw had declined to baseline after 3 ml kg−1 (P=0.39) but not after 7 ml kg−1 (P=0.001) within 60 min. T1/2 was 20 (10-62)/27 (13-43) min (P=0.73) after 3/7 ml kg−1. Conclusion In healthy volunteer children, residual GCVw 1 h after intake of 3 ml kg−1 syrup is significantly smaller than that after 7 ml kg−1 and within the range of baselin

Summary statistics from training images as prior information in probabilistic inversion

A strategy is presented to incorporate prior information from conceptual geological models in probabilistic inversion of geophysical data. The conceptual geological models are represented by multiple-point statistics training images (TIs) featuring the expected lithological units and structural patterns. Information from an ensemble of TI realizations is used in two different ways. First, dominant modes are identified by analysis of the frequency content in the realizations, which drastically reduces the model parameter space in the frequency-amplitude domain. Second, the distributions of global, summary metrics (e.g. model roughness) are used to formulate a prior probability density function. The inverse problem is formulated in a Bayesian framework and the posterior pdf is sampled using Markov chain Monte Carlo simulation. The usefulness and applicability of this method is demonstrated on two case studies in which synthetic crosshole ground-penetrating radar traveltime data are inverted to recover 2-D porosity fields. The use of prior information from TIs significantly enhances the reliability of the posterior models by removing inversion artefacts and improving individual parameter estimates. The proposed methodology reduces the ambiguity inherent in the inversion of high-dimensional parameter spaces, accommodates a wide range of summary statistics and geophysical forward problems

The association of point-of-sale cigarette marketing with cravings to smoke: results from a cross-sectional population-based study

Objective—To examine the association between recalled exposure to point-of-sale (POS) cigarette marketing (ie, pack displays, advertisements and promotions such as discounts) and reported cravings to smoke while visiting a store. Methods—Data were collected using a telephone survey of a cross-sectional sample of 999 adult smokers in Omaha, Nebraska. Recalled exposure to POS cigarette marketing was measured by asking respondents about noticing (a) pack displays, (b) advertisements and (c) promotions in store in their neighbourhood. A 3-item scale indicating the frequency of experiencing cravings to smoke in locations where cigarettes are sold was created by asking respondents: (1) “feel a craving for a cigarette?” (2) “feel like nothing would be better than smoking a cigarette?” and (3) “feel like all you want is a cigarette?” The association between recalled exposure to POS cigarette marketing and cravings was estimated using ordinary least squares linear regression models, controlling for nicotine dependence, gender, age, race/ethnicity, income, education, frequency of visiting stores in one’s neighbourhood and method of recruitment into the study. Results—Recalled exposure to POS cigarette displays (pConclusions—Recalled exposure to POS cigarette marketing is associated with cravings to smoke as predicted by laboratory studies on the effects of smoking cues on cigarette craving. Policies that reduce or eliminate POS cigarette marketing could reduce cigarette cravings and might attenuate impulse buying of cigarettes

Probabilistic electrical resistivity tomography of a CO2 sequestration analog

Electrical resistivity tomography (ERT) is a well-established method for geophysical characterization and has shown potential for monitoring geologic CO2 sequestration, due to its sensitivity to electrical resistivity contrasts generated by liquid/gas saturation variability. In contrast to deterministic inversion approaches, probabilistic inversion provides the full posterior probability density function of the saturation field and accounts for the uncertainties inherent in the petrophysical parameters relating the resistivity to saturation. In this study, the data are from benchtop ERT experiments conducted during gas injection into a quasi-2D brine-saturated sand chamber with a packing that mimics a simple anticlinal geological reservoir. The saturation fields are estimated by Markov chain Monte Carlo inversion of the measured data and compared to independent saturation measurements from light transmission through the chamber. Different model parameterizations are evaluated in terms of the recovered saturation and petrophysical parameter values. The saturation field is parameterized (1) in Cartesian coordinates, (2) by means of its discrete cosine transform coefficients, and (3) by fixed saturation values in structural elements whose shape and location is assumed known or represented by an arbitrary Gaussian Bell structure. Results show that the estimated saturation fields are in overall agreement with saturations measured by light transmission, but differ strongly in terms of parameter estimates, parameter uncertainties and computational intensity. Discretization in the frequency domain (as in the discrete cosine transform parameterization) provides more accurate models at a lower computational cost compared to spatially discretized (Cartesian) models. A priori knowledge about the expected geologic structures allows for non-discretized model descriptions with markedly reduced degrees of freedom. Constraining the solutions to the known injected gas volume improved estimates of saturation and parameter values of the petrophysical relationship. (C) 2014 Elsevier B.V. All rights reserved

Parental smoking and smoking cognitions among youth

$\textit {Aims:}$ We summarized and discussed the empirical evidence for an association between parental smoking and smoking-related cognitions among youth and for the mediating role of smoking-related cognitions in the relation between parental and youth smoking behaviour. $\textit {Methods:}$ We conducted a systematic review of articles published between 1980 and February 2015 using the databases PsychInfo and PubMed. $\textit {Results:}$ The systematic search resulted in 41 eligible studies. Only 4 studies investigated smoking-related cognitions as putative mediators in the association between parental and youth smoking. The synthesis of evidence showed a mix of significant and non-significant associations between parental smoking and smoking-related cognitions among youth. A majority of results reported positive associations even when non-significant findings were found. However, studies that report an effect suggest that the effect may be quite modest. $\textit {Conclusion:}$ Empirical evidence does not confirm the commonly applied assertions of social learning theories that parental smoking increases the risk of youth smoking through the development of favourable smoking-related cognitions. Methodological and theoretical aspects that might explain the lack of consistent findings are discussed

Supplementary Material for: Parental Smoking and Smoking Cognitions among Youth: A Systematic Review of the Literature

<b><i>Aims:</i></b> We summarized and discussed the empirical evidence for an association between parental smoking and smoking-related cognitions among youth and for the mediating role of smoking-related cognitions in the relation between parental and youth smoking behaviour. <b><i>Methods:</i></b> We conducted a systematic review of articles published between 1980 and February 2015 using the databases PsychInfo and PubMed. <b><i>Results:</i></b> The systematic search resulted in 41 eligible studies. Only 4 studies investigated smoking-related cognitions as putative mediators in the association between parental and youth smoking. The synthesis of evidence showed a mix of significant and non-significant associations between parental smoking and smoking-related cognitions among youth. A majority of results reported positive associations even when non-significant findings were found. However, studies that report an effect suggest that the effect may be quite modest. <b><i>Conclusion:</i></b> Empirical evidence does not confirm the commonly applied assertions of social learning theories that parental smoking increases the risk of youth smoking through the development of favourable smoking-related cognitions. Methodological and theoretical aspects that might explain the lack of consistent findings are discussed