751 research outputs found

    The Adequacy of Retirement Saving

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    macroeconomics, saving, retirement

    Roundabouts: Traffic Simulations of Connected and Automated Vehicles—A State of the Art

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    The paper deals with traffic simulation within roundabouts when both “connected and automated vehicles” (CAVs) and human-driven cars are present. The aim is to present the past, current and future research on CAVs running into roundabouts within the Cooperative, Connected and Automated Mobility (CCAM) framework. Both microscopic traffic simulations and virtual reality simulations by dynamic driving simulators will be considered. The paper is divided into five parts. At first, the literature is analysed using the Systematic Literature Review (SLR) methodology based on Scopus database. Secondly, the influence of CAVs on roundabout-specific design features and configuration is analysed. Gap-acceptance models used to define the capacity of the roundabout, one of its most important key performance indicators, are also presented. Third, the most common simulation software are described and analysed in terms of traffic demand implementation. Then the communication approaches and path management algorithms are studied. An example is proposed on the integration of microscopic traffic simulations and dynamic driving simulators virtual reality simulations. Finally, car following models suitable for roundabout traffic are discussed. There is still a gap between simulations and actual experience. There are reasonable doubts on how modelling and optimizing CAVs’ behaviour into roundabouts in view of CCAM. It seems that Cooperative, Connected and Automated Vehicles (CCAVs), more than simply Connected and Automated Vehicles (CAVs), could optimise traffic flow, safety and driving comfort within the roundabout. A very promising technology for traffic simulation within the roundabout seems the one based on dynamic driving simulators

    Reconstructing stakeholder relationships using ‘corporate social responsibility’ as a response strategy to cases of corporate irresponsibility: The case of the 2010 BP spill in the Gulf of Mexico.

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    Purpose When organisations behave irresponsibly, a question remains: Can they use a messaging strategy based in the organisation’s commitment social responsibility to effectively respond to the crisis? The purpose of this chapter is to analyse stakeholder attitudes and their antecedents in such a case. Because of its scope, magnitude and use of a response strategy based on messages of social responsibility, the 2010 BP oil spill in the Gulf of Mexico serves as an excellent case for measuring the effectiveness of such a messaging strategy. Methodology/approach The present study drew from two data sources: a content analysis of interactions on BP’s Facebook page (N=1,515) as well as an image survey of BP (N=749). Findings BP’s messaging strategy had limited positive effects in terms of (1) being viewed as a ‘socially responsible’ organisation and (2) creating significant good will towards the company. However, these data also reveal that BP has effectively opened lines of communication between stakeholders and the company. Practical and social implications This study has two central implications. First, for both organisations and activists, personal investment and the relevance of issues are both critical in order to change stakeholder attitudes about organisations. Second, based on this research, we can begin to develop stakeholder profiles based on age, sex and political identity. Originality/value In the last couple of years, considerable attention has been paid to describing and analysing the response strategies that organisations deploy; however, scant attention has been paid to measuring stakeholder evaluations of those crisis response strategies

    Thiourea Derivative of 2-[(1 R)-1-Aminoethyl]phenol: A Flexible Pocket-like Chiral Solvating Agent (CSA) for the Enantiodifferentiation of Amino Acid Derivatives by NMR Spectroscopy

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    Thiourea derivatives of 2-[(1R)-1-aminoethyl]phenol, (1S,2R)-1-amino-2,3-dihydro-1H-inden-2-ol, (1R,2R)-(1S,2R)-1-amino-2,3-dihydro-1H-inden-2-ol, and (R)-1-phenylethanamine have been compared as chiral solvating agents (CSAs) for the enantiodiscrimination of derivatized amino acids using nuclear magnetic resonance (NMR) spectroscopy. Thiourea derivative, prepared by reacting 2-[(1R)-1-aminoethyl]phenol with benzoyl isothiocyanate, constitutes an effective CSA for the enantiodiscrimination of N-3,5-dinitrobenzoyl (DNB) derivatives of amino acids with free or derivatized carboxyl functions. A base additive 1,4-diazabicyclo[2.2.2]octane(DABCO)/N,N-dimethylpyridin-4-amine (DMAP)/NBu4OH) is required both to solubilize amino acid derivatives with free carboxyl groups in CDCl3 and to mediate their interaction with the chiral auxiliary to attain efficient differentiation of the NMR signals of enantiomeric substrates. For ternary systems CSA/substrate/DABCO, the chiral discrimination mechanism has been ascertained through the NMR determination of complexation stoichiometry, association constants, and stereochemical features of the diastereomeric solvates

    Renewable Resources for Enantiodiscrimination: Chiral Solvating Agents for NMR Spectroscopy from Isomannide and Isosorbide

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    A new family of chiral selectors was synthesized in a single synthetic step with yields up to 84% starting from isomannide and isosorbide. Mono- or disubstituted carbamate derivatives were obtained by reacting the isohexides with electron-donating arylisocyanate (3,5-dimethylphenyl- or 3,5-dimethoxyphenyl-) and electron-withdrawing arylisocyanate (3,5-bis(trifluoromethyl)phenyl-) groups to test opposite electronic effects on enantiodifferentiation. Deeper chiral pockets and derivatives with more acidic protons were obtained by derivatization with 1-naphthylisocyanate and p-toluenesulfonylisocyanate, respectively. All compounds were tested as chiral solvating agents (CSAs) in H-1 NMR experiments with rac-N-3,5-dinitrobenzoylphenylglycine methyl ester in order to determine the influence of different structural features on the enantiodiscrimination capabilities. Some selected compounds were tested with other racemic analytes, still leading to enantiodiscrimination. The enantiodiscrimination conditions were then optimized for the best CSA/analyte couple. Finally, a 2D- and 1D-NMR study was performed employing the best performing CSA with the two enantiomers of the selected analyte, aiming to determine the enantiodiscrimination mechanism, the stoichiometry of interaction, and the complexation constant

    Rilevazione statistica della diffusione e della conoscenza di sostanze dopanti, integratori e dell' Exercise Addiction

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    I benefici derivanti dalla pratica dell'esercizio fisico sono stati ampiamente documentati. Tuttavia, l’eccessivo ricorso alla attività fisica può condurre alla messa in atto di pattern compulsivi di allenamento che possono evolversi in una vera e propria patologia: l' exercise addiction. Studi recenti suggeriscono l'espansione di due fenomeni: il doping amatoriale e l'abuso di integratori per lo sport. Sono stati somministrati 686 test. I partecipanti allo studio sono stati scelti tra studenti di scuola media superiore, studenti universitari e frequentatori di ambienti sportivi. Il 42,5% degli intervistati dichiara di assumere sostanze per migliorare le prestazioni sportive e quindi di doparsi. Il 30,23% assume integratori. Una percentuale compresa tra il 35 e l'88,35 % dichiara di non conoscere le sostanze proposte.Il 15,8% dei rispondenti è a “rischio” di exercise addiction, il 71,7% è classificato come “sintomatico”. E' stata infine indagata quale possibile correlazione potesse esserci tra le variabili in esame. La statistica test X2 evidenzia che non vi è alcuna associazione , in altre parole non sembra esserci relazione tra il rischio di dipendenza dall' esercizio fisico e l'assunzione di sostanze. L'analisi dei dati raccolti suggerisce invece che vi sia un'espansione del fenomeno del doping in ambiente amatoriale e che vi sia una scriteriata e incongrua assunzione di integratori per lo sport. La presente ricerca suggerisce che occorre compiere interventi immediati sia a livello di informazione che di prevenzione , in cui al farmacista sia affidato un ruolo di primo piano

    2-Methyl-β-cyclodextrin grafted ammonium chitosan: synergistic effects of cyclodextrin host and polymer backbone in the interaction with amphiphilic prednisolone phosphate salt as revealed by NMR spectroscopy

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    Reduced molecular weight chitosan was quaternized with 2-chloro-N,N-diethylethylamine to obtain a water soluble derivative (N+-rCh). Methylated-β-cyclodextrin (MCD), with 0.5 molar substitution, was covalently linked to N+-rCh through 1,6-hexamethylene diisocyanate spacer to give the derivatized ammonium chitosan N+-rCh-MCD. To shed light on the role of the cyclodextrin pendant in guiding binding interactions with amphiphilic active ingredients, corticosteroid prednisolone phosphate salt (PN) was considered. The deep inclusion of PN into cyclodextrin in PN/MCD model system was pointed out by analysis of 1H NMR complexation shifts, 1D ROESY spectra, and diffusion measurements (DOSY). By using proton selective relaxation rates measurements as investigation tool, the superior affinity of N+-rCh-MCD towards PN was demonstrated in comparison with parent ammonium chitosan N+-rCh

    Dynamics of neutrophils to lymphocyte ratio (NLR) predict outcomes of PD-1/PD-L1 blockade

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    Introduction. Baseline neutrophil-to-lymphocyte ratio (NLR) has been repeatedly reported as a significant prognostic factor in advanced cancer patients. We explored whether changes in NLR may predict outcome of advanced cancer patients enrolled into phase 1 trials and treated with PD-1/PD-L1 inhibitors. Patients and Methods. Advanced cancer patients enrolled into phase 1 trials between September 2013 and May 2016 and treated with anti-PD-1/PD-L1 agents were included in this retrospective study. NLR was calculated at baseline and after 2 cycles of treatment. Royal Marsden Hospital (RMH) prognostic score and Eastern Cooperative Group (ECOG) performance status (PS) were determined at baseline. Kaplan-Meier estimation and Cox regression analyses were used to assess the impact of NLR dynamics on PFS. Results. Among the 55 patients eligible, 26 (47%) were treated with anti-PD-L1 monotherapy, 22 (40%) received single agent anti-PD-1, and 7 (13%) were given a tyrosine kinase inhibitor (TKI) plus a PD-1 inhibitor. Neither ECOG PS nor RMH prognostic score was significantly associated with PFS in our cohort, whereas changes in NLR significantly impacted on PFS. Conclusion. Changes in the NLR may be a useful predicting factor in advanced cancer patients treated with anti-PD-1/PD-L1 agents. Further prospective trials are needed to verify these findings

    Methylammonium-formamidinium reactivity in aged organometal halide perovskite inks

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    Over the past 10 years, organometal halide perovskites have revolutionized the field of optoelectronics, particularly of emerging photovoltaic technologies. Today's best perovskite solar cells use triple-cation compositions containing a mixture of formamidinium, methylammonium, and cesium to enable more reproducible and stable device performance. The common procedure uses as-prepared precursor ink to avoid an undesirable decrease in device performance, attributed recently to a chemical reaction between methylammonium and formamidinium in solution. Here we employ nuclear magnetic resonance spectroscopy to explore different experimental conditions that can significantly modify these reaction kinetics; in particular, we find that the presence of cesium as the third cation can substantially slow down methylammonium-formamidinium reactivity. Our findings allow us to draw up a protocol for extended overtime perovskite ink stabilization
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