2,795 research outputs found

    Extrapolation in games of coordination and dominance solvable games

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    We study extrapolation between games in a laboratory experiment. Participants in our experiment first play either the dominance solvable guessing game or a Coordination version of the guessing game for five rounds. Afterwards they play a 3x3 normal form game for ten rounds with random matching which is either a game solvable through iterated elimination of dominated strategies (IEDS), a pure Coordination game or a Coordination game with pareto ranked equilibria. We find strong evidence that participants do extrapolate between games. Playing a strategically different game hurts compared to the control treatment where no guessing game is played before and in fact impedes convergence to Nash equilibrium in both the 3x3 IEDS and the Coordination games. Playing a strategically similar game before leads to faster convergence to Nash equilibrium in the second game. In the Coordination games some participants try to use the first game as a Coordination device. Our design and results allow us to conclude that participants do not only learn about the population and/or succesful actions, but that they are also able to learn structural properties of the games

    Isoflavones and other compounds from the roots of Iris marsica I. Ricci E Colas. Collected from Majella National Park, Italy

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    In this study, a phytochemical analysis was performed, for the first time, on Iris marsica I. Ricci e Colas. In particular, the attention was focused on the constituents of the roots. Twenty-one compounds were isolated by column chromatography and were analyzed/identified by NMR spectroscopy and mass spectrometry. They all own chemotaxonomic, ethno-pharmacological and nutraceutical relevance which allowed us to provide a phytochemical rationale, for the correct botanical classification of this species, for the employment of its roots in folk medicine like for all the other species belonging to the Iris genus and, lastly, for their further uses as food with important healthy benefits. All of these parts were broadly discussed about within the text

    Ethylic esters as green solvents for the extraction of intracellular polyhydroxyalkanoates produced by mixed microbial culture

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    Volatile fatty acids obtained from the fermentation of the organic fraction of municipal solid waste can be used as raw materials for non-toxic ethyl ester (EE) synthesis as well as feedstock for the production of polyhydroxyalkanoates (PHAs). Taking advantage of the concept of an integrated process of a bio-refinery, in the present paper, a systematic investigation on the extraction of intracellular poly(3-hydroxybutyrate-co-3-hydroxyvalerate), produced by mixed microbial culture by using EEs was reported. Among the tested EEs, ethyl acetate (EA) was the best solvent, dissolving the copolymer at the lowest temperature. Then, extraction experiments were carried out by EA at different temperatures on two biomass samples containing PHAs with different average molecular weights. The parallel characterization of the extracted and non-extracted PHAs evidenced that at the lower temperature (100◦C) EA solubilizes preferentially the polymer fractions richer in 3HV comonomers and with the lower molecular weight. By increasing the extraction temperature from 100◦C to 125◦C, an increase of recovery from about 50 to 80 wt% and a molecular weight reduction from 48% to 65% was observed. The results highlighted that the extracted polymer purity is always above 90 wt% and that it is possible to choose the proper extraction condition to maximize the recovery yield at the expense of polymer fractionation and degradation at high temperatures or use milder conditions to maintain the original properties of a polymer

    Essential oil composition and polar fraction analysis of Tanacetum macrophyllum (Waldst. et Kit.) Schultz Bip.

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    Tanacetum macrophyllum (Waldst. et Kit.) Schultz Bip, also known as Tansy, is a perennial herbaceous plant belonging to the Asteraceae family. This species is typical of the Balcan area but is punctually spread in other European countries as a rare species [1]. In Italy, it is found mainly within forests [1, 2]. This species is often erroneously confused with Achillea grandifolia Friv. [1, 2]. In this work, a comprehensive phytochemical analysis on the volatile components and polar fraction of T. macrophyllum growing in central Italy was carried out. Flowers and leaves were separately analyzed for the essential oil composition and were characterized by oxygenated monoterpenes (39.4%) and oxygenated sesquiterpenes (28.0%) and sesquiterpene hydrocarbons (39.3%) and oxygenated monoterpenes (25.4%), respectively. The phytochemical analysis conducted on the ethanolic extract of the total aerial parts evidenced the presence of twelve compounds: apigenin, cirsimaritin, apigenin-7-O-glucoside, apigenin-7-O-glucuronide, kaempferol-7-O-glucoside, kaempferol-7-O-glucuronide, 3,5-dicaffeoylquinic acid, 4,5-dicaffeoylquinic acid, chlorogenic acid, shikimic acid, quinic acid and 4-O-β-D-glucopyranosyl-vanillic acid. Most of these compounds were reported for the first time in the species while three of them are new phytochemicals for the Tanacetum genus. The presence of all these compounds provides a phytochemical rationale for the botanical classification of this species and encourages further ethno-pharmacological studies just like for T. parthenium [3]

    Study of the time and space distribution of beta+ emitters from 80 MeV/u carbon ion beam irradiation on PMMA

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    Proton and carbon ion therapy is an emerging technique used for the treatment of solid cancers. The monitoring of the dose delivered during such treatments and the on-line knowledge of the Bragg peak position is still a matter of research. A possible technique exploits the collinear 511\ \kilo\electronvolt photons produced by positrons annihilation from β+\beta^+ emitters created by the beam. This paper reports rate measurements of the 511\ \kilo\electronvolt photons emitted after the interactions of a 80\ \mega\electronvolt / u fully stripped carbon ion beam at the Laboratori Nazionali del Sud (LNS) of INFN, with a Poly-methyl methacrylate target. The time evolution of the β+\beta^+ rate was parametrized and the dominance of 11C^{11}C emitters over the other species (13N^{13}N, 15O^{15}O, 14O^{14}O) was observed, measuring the fraction of carbon ions activating β+\beta^+ emitters A0=(10.3±0.7)103A_0=(10.3\pm0.7)\cdot10^{-3}. The average depth in the PMMA of the positron annihilation from β+\beta^+ emitters was also measured, D_{\beta^+}=5.3\pm1.1\ \milli\meter, to be compared to the expected Bragg peak depth D_{Bragg}=11.0\pm 0.5\ \milli\meter obtained from simulations

    Measurement of charged particle yields from therapeutic beams in view of the design of an innovative hadrontherapy dose monitor

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    Particle Therapy (PT) is an emerging technique, which makes use of charged particles to efficiently cure different kinds of solid tumors. The high precision in the hadrons dose deposition requires an accurate monitoring to prevent the risk of under-dosage of the cancer region or of over-dosage of healthy tissues. Monitoring techniques are currently being developed and are based on the detection of particles produced by the beam interaction into the target, in particular: charged particles, result of target and/or projectile fragmentation, prompt photons coming from nucleus de-excitation and back-to-back γ s, produced in the positron annihilation from β + emitters created in the beam interaction with the target. It has been showed that the hadron beam dose release peak can be spatially correlated with the emission pattern of these secondary particles. Here we report about secondary particles production (charged fragments and prompt γ s) performed at different beam and energies that have a particular relevance for PT applications: 12C beam of 80 MeV/u at LNS, 12C beam 220 MeV/u at GSI, and 12C, 4He, 16O beams with energy in the 50–300 MeV/u range at HIT. Finally, a project for a multimodal dose-monitor device exploiting the prompt photons and charged particles emission will be presented

    Liquid Structure of a Water-in-Salt Electrolyte with a Remarkably Asymmetric Anion

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    Water-in-salt systems, i.e., super-concentrated aqueous electrolytes, such as lithium bis(trifluoromethanesulfonyl)imide (21 mol/kgwater), have been recently discovered to exhibit unexpectedly large electrochemical windows and high lithium transference numbers, thus paving the way to safe and sustainable charge storage devices. The peculiar transport features in these electrolytes are influenced by their intrinsically nanoseparated morphology, stemming from the anion hydrophobic nature and manifesting as nanosegregation between anions and water domains. The underlying mechanism behind this structure-dynamics correlation is, however, still a matter of strong debate. Here, we enhance the apolar nature of the anions, exploring the properties of the aqueous electrolytes of lithium salts with a strongly asymmetric anion, namely, (trifluoromethylsulfonyl)(nonafluorobutylsulfonyl) imide. Using a synergy of experimental and computational tools, we detect a remarkable level of structural heterogeneity at a mesoscopic level between anion-rich and water-rich domains. Such a ubiquitous sponge-like, bicontinuous morphology develops across the whole concentration range, evolving from large fluorinated globules at high dilution to a percolating fluorous matrix intercalated by water nanowires at super-concentrated regimes. Even at extremely concentrated conditions, a large population of fully hydrated lithium ions, with no anion coordination, is detected. One can then derive that the concomitant coexistence of (i) a mesoscopically segregated structure and (ii) fully hydrated lithium clusters disentangled from anion coordination enables the peculiar lithium diffusion features that characterize water-in-salt systems

    Extended calibration range for prompt photon emission in ion beam irradiation

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    Monitoring the dose delivered during proton and carbon ion therapy is still a matter of research. Among the possible solutions, several exploit the measurement of the single photon emission from nuclear decays induced by the irradiation. To fully characterize such emission the detectors need development, since the energy spectrum spans the range above the MeV that is not traditionally used in medical applications. On the other hand, a deeper understanding of the reactions involving gamma production is needed in order to improve the physic models of Monte Carlo codes, relevant for an accurate prediction of the prompt-gamma energy spectrum.This paper describes a calibration technique tailored for the range of energy of interest and reanalyzes the data of the interaction of a 80MeV/u fully stripped carbon ion beam with a Poly-methyl methacrylate target. By adopting the FLUKA simulation with the appropriate calibration and resolution a significant improvement in the agreement between data and simulation is reported.Comment: 4 pages, 7 figures, Submitted to JINS

    Measurement of secondary particle production induced by particle therapy ion beams impinging on a PMMA target

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    Particle therapy is a technique that uses accelerated charged ions for cancer treatment and combines a high irradiation precision with a high biological effectiveness in killing tumor cells [1]. Informations about the secondary particles emitted in the interaction of an ion beam with the patient during a treatment can be of great interest in order to monitor the dose deposition. For this purpose an experiment at the HIT (Heidelberg Ion-Beam Therapy Center) beam facility has been performed in order to measure fluxes and emission profiles of secondary particles produced in the interaction of therapeutic beams with a PMMA target. In this contribution some preliminary results about the emission profiles and the energy spectra of the detected secondaries will be presente
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