Toward an automatic full-wave inversion: Synthetic study cases

Full-waveform inversion (FWI) in seismic scenarios continues to be a complex procedure for subsurface imaging that might require extensive human interaction in terms of model setup, constraints, and data preconditioning. The underlying reason is the strong nonlinearity of the problem that forces the addition of a priori knowledge (or bias) in order to obtain geologically sound results. In particular, when the use of a long-offset receiver is not possible or may not favor the reconstruction of the fine structure of the model, one needs to rely on reflection data. As a consequence, the inversion process is more prone to becoming stuck in local minima. Nevertheless, misfit functionals can be devised that can either cope with missing long-wavenumber features of initial models (e.g., cross-correlation-based misfit) or invert reflection-dominated data whenever the models are sufficiently good (e.g., normalized offset-limited least-squares misfit). By combining both, high-frequency data content with poor initial models can be successfully inverted. If one can figure out simple parameterizations for such functionals, the amount of uncertainty and manual work related to tuning FWI would be substantially reduced. Thus, FWI might become a semiautomatized imaging tool.We want to thank Repsol for funding this research by means of the Aurora project. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 644202. Additionally, the research leading to these results has received funding from the European Union’s Horizon 2020 Programme (2014-2020) and from Brazilian Ministry of Science, Technology and Innovation through Rede Nacional de Pesquisa (RNP) under the HPC4E Project (www.hpc4e.eu), grant agreement No 689772. We acknowledge Chevron for the dataset that was used in our second example.Peer ReviewedPostprint (author's final draft

First sexual intercourse and subsequent regret in three developing countries

Purpose: Adolescents who engage in sex can be affected by a range of negative physical and psychological consequences. We intend to analyze the reasons behind first sex, regret, and the association between reasons and regret. Methods: A questionnaire was implemented to 8495 high schools students, aged 14-18, in the Philippines, El Salvador and Peru. Sexually active participants responded whether several circumstances were reasons involved in their first sexual relationship. They also responded whether they regretted having already had sexual relationships. Results: More than a third of respondents reported at least one external pressure leading to first sex, and about half reported at least one reason implying getting carried away by sexual arousal. More females affirmed they regret having already had sex. Logistic regression shows that reasons for first sex associated with regret were partner insistence, "uncontrolled situations" and seeing sexual images. These reasons were associated with regret even when love was also reported as related to first sex. Conclusions: Adolescent sexual experience is often motivated by pressure and circumstances that lower the control over their decisions concerning sex, such as external pressure (because most friends already had sex or because of partner insistence) or getting carried away by sexual arousal (through an "uncontrolled situation" or viewing sexual images) rather than by mature decisions, and this may result in later regret. Adolescents should be helped by parents, educators and policy makers to be aware of these characteristics of adolescent sex and empowered to make assertive and informed decisions concerning their sexuality

Perhalophenyl Three-Coordinate Gold(I) Complexes as TADF Emitters : A Photophysical Study from Experimental and Computational Viewpoints

We report the synthesis of novel perhalophenyl three- coordinated gold( I) complexes using 1,2- bis-(diphenylphosphino)benzene (dppBz) as the chelating ligand and [AuR(tht)] (R = C6F5, C6Cl2F3, C6Cl5) as the perhalophenyl-gold(I) source, leading to [AuR(dppBz)] (R = C6F5 (1), C6Cl2F3 (2), C6Cl5 (3)) complexes. The solid-state structures of compounds 2 and 3 consist of discrete three-coordinated Au(I) complexes, which show a distorted trigonal planar geometry for the gold center with dissimilar Au-P distances. The distorted structural arrangement is closely related to its photophysical properties. The studied complexes display very intense emissions at room temperature (RT) and at 77 K in the solid state. Studies of the emissive properties of the complexes at different temperatures suggest that the emissions are phosphorescent at 77 K and exhibit thermally activated delayed fluorescence (TADF) at RT. First-principle calculations of the photophysical processes yielded rate constants for intersystem crossing and reverse intersystem crossing that are in excellent agreement with experimental data.Peer reviewe

Free and Open Source Software underpinning the European Forest Data Centre

Worldwide, governments are growingly focusing on free and open source software (FOSS) as a move toward transparency and the freedom to run, copy, study, change and improve the software. The European Commission (EC) is also supporting the development of FOSS [...]. In addition to the financial savings, FOSS contributes to scientific knowledge freedom in computational science (CS) and is increasingly rewarded in the science-policy interface within the emerging paradigm of open science. Since complex computational science applications may be affected by software uncertainty, FOSS may help to mitigate part of the impact of software errors by CS community- driven open review, correction and evolution of scientific code. The continental scale of EC science-based policy support implies wide networks of scientific collaboration. Thematic information systems also may benefit from this approach within reproducible integrated modelling. This is supported by the EC strategy on FOSS: "for the development of new information systems, where deployment is foreseen by parties outside of the EC infrastructure, [F]OSS will be the preferred choice and in any case used whenever possible". The aim of this contribution is to highlight how a continental scale information system may exploit and integrate FOSS technologies within the transdisciplinary research underpinning such a complex system. A European example is discussed where FOSS innervates both the structure of the information system itself and the inherent transdisciplinary research for modelling the data and information which constitute the system content. [...

Multi-analyte method for the quantification of bisphenol related compounds in canned food samples and exposure assessment of the Spanish adult population

Major types of internal can coatings used for food and beverages are made from synthetic polymers known as epoxy-based resins, mainly based on bisphenol A diglycidyl ether (BADGE). The migration of components from coatings to food is a concern for food safety. A multiresidue method was developed for the identification and quantification of six bisphenols, BADGE and its derivatives, and cyclo-di-BADGE in sixteen canned food samples based on HPLC-FLD. The method developed showed excellent validation data with an adequate linearity, low detection levels, good repeatability and acceptable recoveries. Confirmation of the obtained results was made by LC–MS/MS. The exposure of the adult population to these compounds through the consumption of canned food was assessed. In general, the results suggested a low dietary exposure to this type of compounds (0.003 to 0.985 μg/kg bw/day) with values lower than the established tolerable day intake (TDI). The highest mean concentration was observed for cyclo-di-BADGE in a sample of pickled musselsS

Use of colonoscopy as a primary screening test for colorectal cancer in average risk people

The use of colonoscopy as a primary screening test for colorectal cancer (CRC) in average risk adults is a subject of controversy. Our primary objective was to build a predictive model based on a few simple variables that could be used as a guide for identifying average risk adults more suitable for examination with colonoscopy as a primary screening test. METHODS: The prevalence of advanced adenomas was assessed by primary screening colonoscopy in 2210 consecutive adults at least 40 yr old, without known risk factors for CRC. Age, gender, and clinical and biochemical data were compared among people without adenomas, those with non-advanced adenomas, and those with any advanced neoplasm. A combined score to assess the risk of advanced adenomas was built with the variables selected by multiple logistic regression analysis. RESULTS: Neoplastic lesions were found in 617 subjects (27.9%), including 259 with at least one neoplasm that was 10 mm or larger, villous, or with moderate-to-severe dysplasia, and 11 with invasive cancers. Advanced lesions were more frequent among men, older people, and those with a higher body mass index (BMI). These three variables were independent predictors of advanced adenomas in multivariate analysis. A score combining age, sex, and BMI was developed as a guide for identifying individuals more suitable for screening colonoscopy. CONCLUSIONS: Age, gender, and BMI can be used to build a simple score to select those average risk adults who might be candidates for primary screening colonoscop

Mini AuAg Wavy Nanorods Displaying Plasmon-Induced Photothermal and Photocatalytic Properties

Alloyed AuAg wavy nanorods (wNRs) of approximate to 24.0 nm length and 3.5 nm width are formed by the mild decomposition of the organometallic complex [Au2Ag2(C6F5)(4)(OEt2)(2)](n) in tetrahydrofuran (THF) in the presence of oleic acid. Ligand exchange with l-glutathione (GSH) or poly(ethylene glycol) methyl ether thiol (PEG-SH) leads to water-soluble nanostructures. These AuAg wNRs display tunable size-dependent longitudinal localized surface plasmon resonance (l-LSPR) broad absorptions beyond 750 nm in the near-infrared (NIR) I and II regions. These intense plasmonic absorptions lead to interesting photothermal, catalytic, and photocatalytic properties, including the catalytic reduction of 4-nitrophenol, the photocatalytic reduction of 4-nitrostyrene, or the photocatalytic dehydrogenation of ammonia borane for H-2 release

Diagnostic value of distal colonic polyps for prediction of advanced proximal neoplasia in an average-risk population undergoing screening colonoscopy

For colorectal cancer screening, the predictive value of distal findings in the ascertainment of proximal lesions is not fully established. The aims of this study were to assess distal findings as predictors of advanced proximal neoplasia and to compare the predictive value of endoscopy alone vs. combined endoscopic and histopathologic data. METHODS: Primary colonoscopy screening was performed in 2210 consecutive, average-risk adults. Age, gender, endoscopic (size, number of polyps), and histopathologic distal findings were used as potential predictors of advanced proximal neoplasms (i.e., any adenoma > or =1 cm in size, and/or with villous histology, and/or with severe dysplasia or invasive cancer). Polyps were defined as distal if located in the descending colon, the sigmoid colon, or the rectum. Those in other locations were designated proximal. RESULTS: Neoplastic lesions, including 11 invasive cancers, were found in 617 (27.9%) patients. Advanced proximal neoplasms without any distal adenoma were present in 1.3% of patients. Of the advanced proximal lesions, 39% were not associated with any distal polyp. Older age, male gender, and distal adenoma were independent predictors of advanced proximal neoplasms. The predictive ability of a model with endoscopic data alone did not improve after inclusion of histopathologic data. In multivariate logistic regression analysis, the predictive ability of models that use age, gender, and any combination of distal findings was relatively low. The proportion of advanced proximal neoplasms identified if any distal polyp was an indication for colonoscopy was only 62%. CONCLUSIONS: A strategy in which colonoscopy is performed solely in patients with distal colonic findings is not effective screening for the detection of advanced proximal neoplasms in an average-risk populatio

Alcohol and early mortality (before 65 years) in the ‘seguimiento Universidad de Navarra’ (SUN) cohort: does any level reduce mortality?

The aim of this study was to assess the association between alcohol intake and premature mortality (younger than 65 years) and to explore the effect of potential alcohol underreporting by heavy drinkers. We followed-up 20 272 university graduates. Four categories of alcohol intake were considered (abstainer, light, moderate and heavy consumption). Repeated measurements of alcohol intake and updated information on confounders were used in time-dependent Cox models. Potential underreporting of alcohol intake by some heavy drinkers (likely misclassified as light or moderate drinkers) was explicitly addressed in an attempt to correct potential underreporting by using indirect information. During 12·3 years of median follow-up (interquartile range: 6·8–15·0), 226 participants died before their 65th birthday. A higher risk of early mortality was found for the highest category of alcohol intake (≥50 g/d) in comparison with abstention (multivariable-adjusted hazard ratio (HR) = 2·82, 95 % CI 1·38, 5·79). In analyses of alcohol as a continuous variable, the multivariable-adjusted HR was 1·17 (95 % CI 1·08, 1·26), for each 10 g/d of alcohol. This harmful linear association was present both in uncorrected models and in models corrected for potential underreporting. No significant inverse association between light or moderate alcohol intake and premature mortality was observed, even after correcting for potential misclassification. Alcohol intake exhibited a harmful linear dose–response association with premature mortality (<65 years) in this young and highly educated Mediterranean cohort. Our attempts to correct for potential misclassification did not substantially change these results

Influence of perhalophenyl groups in the TADF mechanism of diphosphino gold(I) complexes

New perhalophenyl three-coordinated gold(i) complexes using the chelate ligand 1,2-bis(diphenyl-phosphino)benzene (dppBz) and [AuR(tht)] (R = C6F5 (1), o-C6BrF4 (2), p-C6BrF4 (3), o-C6F4I (4), p-C6F4I (5); tht = tetrahydrothiophene) have been prepared. The crystal structures of compounds 1 and 2 consist of distorted three-coordinated Au(i) complexes displaying different Au-P distances at the same gold atom. The complexes show intense photoluminescent emission in the solid state at room temperature (RT) and at 77 K. The study of the dependence of the emission lifetime with temperature suggests the existence of thermally activated delayed fluorescence (TADF) processes at RT. We have computed the rate constants for intersystem crossing and reverse intersystem crossing of the photophysical processes through first-principle calculations, supporting the experimental observations with very good agreement.Peer reviewe