773 research outputs found

    Globalisation and the decline of the labour share: a microeconomic perspective

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    This paper contributes to the infant literature on the determinants of the labour share at the level of individual firms and provides novel insights on the effect of firms’ patterns of internationalisation. The analysis is performed using a rich dataset, covering six EU countries (Austria, France, Germany, Hungary, Italy and Spain), and combining information from the EFIGE survey and Amadeus balance sheets. Our results show that the labour share is lower for exporting firms and for those engaged in foreign direct investments or offshoring activities. These findings are robust to an array of sensitivity tests. Our instrumental variable analysis indicates that causation goes from internationalization to changes in the labour share. Investigation into the channels of the negative impact of internationalisation shows that these effects are not related to the composition of the labour force, nor to technological factors or firm market power. The analysis for subsectors of different technological regimes is consistent with this interpretation

    Rigidity for perimeter inequality under spherical symmetrisation

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    Necessary and sufficient conditions for rigidity of the perimeter inequality under spherical symmetrisation are given. That is, a characterisation for the uniqueness (up to orthogonal transformations) of the extremals is provided. This is obtained through a careful analysis of the equality cases, and studying fine properties of the circular symmetrisation, which was firstly introduced by Pólya in 1950

    Numerical modelling of centrifuge dynamic tests of circular tunnels in dry sand

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    This paper describes the numerical simulation of two dynamic centrifuge tests on reduced scale models of shallow tunnels in dry sand, carried out using both an advanced bounding surface plasticity constitutive soil model and a simple Mohr–Coulomb elastic-perfectly plastic model with embedded nonlinear and hysteretic behaviour. The predictive capabilities of the two constitutive models are assessed by comparing numerical predictions and experimental data in terms of accelerations at several positions in the model, and bending moment and hoop forces in the lining. Computed and recorded accelerations match well, and a quite good agreement is achieved also in terms of dynamic bending moments in the lining, while numerical and experimental values of the hoop force differ significantly with one another. The influence of the contact assumption between the tunnel and the soil is investigated by comparing the experimental data and the numerical results obtained with different interface conditions with the analytical solutions. The overall performance of the two models is very similar indicating that at least for dry sand, where shear-volumetric coupling is less relevant, even a simple model can provide an adequate representation of soil behaviour under dynamic condition

    A Study of Out-of-turn Interaction in Menu-based, IVR, Voicemail Systems

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    We present the first user study of out-of-turn interaction in menu-based, interactive voice-response systems. Out-ofturn interaction is a technique which empowers the user (unable to respond to the current prompt) to take the conversational initiative by supplying information that is currently unsolicited, but expected later in the dialog. The technique permits the user to circumvent any flows of navigation hardwired into the design and navigate the menus in a manner which reflects their model of the task. We conducted a laboratory experiment to measure the effect of the use of outof- turn interaction on user performance and preference in a menu-based, voice interface to voicemail. Specifically, we compared two interfaces with the exact same hierarchical menu design: one with the capability of accepting out-ofturn utterances and one without this feature. The results indicate that out-of-turn interaction significantly reduces task completion time, improves usability, and is preferred to the baseline. This research studies an unexplored dimension of the design space for automated telephone services, namely the nature of user-addressable input (utterance) supplied (in-turn vs. out-of-turn), in contrast to more traditional dimensions such as input modality (touch-tone vs. text vs. voice) and style of interaction (menu-based vs. natural language)

    Viscosity of Pyroxenite Melt and Its Evolution During Cooling

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    New viscosity experiments at superliquidus temperatures and during cooling at a rate of 10 K/hr have been performed at different shear rates on a synthetic pyroxenite melt. Results revealed that this melt is extremely fluid at temperature between 1646 and 1530 K and measured viscosities are between 2.2 and 7.8 Pa·s. Such very low viscosities allow the lava to flow in turbulent regime as confirmed by the high Reynolds numbers, which are always >2,000. As a consequence, very long distance could be covered by the lava flow. If we consider this studied composition as proxy for Mars lava flows coupled with very high effusion rates, our results might explain the presence of extraordinary large volcanic channels, as recently hypothesized for the Kasei Valles on Mars, even considering that the gravity is approximately one third that of Earth. Few literature data tracking viscosity during cooling are available, and they reported shear thinning effect on different compositions. Our experiments performed at 0.1 and 1 s−1 have shown complex variation in the apparent viscosity, confirming that nonequilibrium rheology represents a still unexplored field of investigation useful to better understand the real geological scenarios occurring in magmatic and volcanic systems. ©2019. American Geophysical Union. All Rights Reserved

    Cystic echinococcosis in water buffaloes (Bubalus bubalis)

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    An epidemiological and molecular survey of cystic echinococcosis (CE) caused by Echinococcus granulosus in the water buffalo (Bubalus bubalis) of the Italian Mediterranean breed was carried out in the Campania region of southern Italy. Out of a total of 799 water buffaloes examined at slaughterhouses, 80 (10.0%) were found infected. The molecular study was performed on 58 hydatid cysts in order to determine the E. granulosus strain(s) present in this host. A region of cytocrome c oxydase 1 gene (CO1) was amplified by polymerase chain reaction and the PCR products were then purified and sequenced. DNA amplification of the partial CO1 gene gave a 446 bp fragment for all isolates examined. After sequencing, a region of 419 bp was identified for each sample. Thirty-two isolates were identified as the common sheep strain G1, 15 as the buffalo strain G3, 3 as the Tasmanian sheep strain G2, and 3 as the G1 c genotype (GenBank AF458873). In addition, 5 isolates presented 99% identity with the G2 genotype (Tasmanian sheep strain)

    Eruption dynamics of the 22–23 April 2015 calbuco volcano (Southern Chile): Analyses of tephra fall deposits

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    After 54 years since its last major eruption in 1961, Calbuco Volcano (Ensenada, Southern Chile) reawakened with few hours of warning on 22 April 2015 at 18:05 local time. The main explosive eruption consisted of two eruption pulses (lasting ~1.5 and 6 h each one) on 22 and 23 April, producing stratospheric (>15 km height) eruption columns. The erupted materials correspond to porphyritic basaltic andesite (~55 wt.% of SiO2). The tephra fall affected mainly the area northeast of the volcano and the finest ash was deposited over Southern Chile and Patagonia Argentina. We studied the tephra fall deposits of both pulses in terms of stratigraphy, distribution, volume, emplacement dynamics and eruption source parameters. Here, we show field observations that have been made 5-470 km downwind and distinguish five layers (Layers A, B, B1, C and D) representing different stages of the eruption evolution: eruption onset (Layer A; pulse 1), followed by the first paroxysmal event (Layer B; pulse 1), in some places interbedded by layer B1, tentatively representing the sedimentation of a secondary plume during the end of pulse 1. We recognized a second paroxysm (Layer C; pulse 2) followed by the waning of the eruption (Layer D; pulse 2). The total calculated bulk tephra fall deposit volume is 0.27 ± 0.007 km3 (0.11-0.13 km3 dense rock equivalent), 38% of which was erupted during the first phase and 62% during the second pulse. This eruption was a magnitude 4.45 event (VEI 4 eruption) of subPlinian type.Fil: Romero, J. E.. Universidad de Atacama; ChileFil: Morgavi, D.. Università di Perugia; ItaliaFil: Arzilli, F.. University of Manchester; Reino UnidoFil: Daga, Romina Betiana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Caselli, Alberto Tomás. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Negro; ArgentinaFil: Reckziegel, Florencia Mabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones en Energía no Convencional. Universidad Nacional de Salta. Facultad de Ciencias Exactas. Departamento de Física. Instituto de Investigaciones en Energía no Convencional; ArgentinaFil: Viramonte, Jose German. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones en Energía no Convencional. Universidad Nacional de Salta. Facultad de Ciencias Exactas. Departamento de Física. Instituto de Investigaciones en Energía no Convencional; ArgentinaFil: Díaz Alvarado, J.. Universidad de Atacama; ChileFil: Polacci, M.. University of Manchester; Reino UnidoFil: Burton, M.. University of Manchester; Reino UnidoFil: Perugini, D.. Università di Perugia; Itali

    Retrieving magma composition from TIR spectra: implications for terrestrial planets investigations

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    Emissivity and reflectance spectra have been investigated on two series of silicate glasses, having compositions belonging to alkaline and subalkaline series, covering the most common terrestrial igneous rocks. Glasses were synthesized starting from natural end-members outcropping at Vulcano Island (Aeolian Islands, Italy) and on Snake River Plain (USA). Results show that the shift of the spectra, by taking Christiansen feature (CF) as a reference point, is correlated with SiO2 content, the SCFM factor and/or the degree of polymerization state via the NBO/T and temperature. The more evolved is the composition, the more polymerized the structure, the shorter the wavelength at which CF is observable. CF shift is also dependent on temperature. The shape of the spectra discriminates alkaline character, and it is related to the evolution of Qn structural units. Vulcano alkaline series show larger amount of Q4 and Q3 species even for mafic samples compared to the subalkaline Snake River Plain series. Our results provide new and robust insights for the geochemical characterization of volcanic rocks by remote sensing, with the outlook to infer origin of magmas both on Earth as well as on terrestrial planets or rocky bodies, from emissivity and reflectance spectra

    A Generative Programming Approach to Interactive Information Retrieval:Insights and Experiences

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    Abstract. We describe the application of generative programming to a problem in interactive information retrieval. The particular interactive information retrieval problem we study is the support for ‘out of turn interaction ’ with a website – how a user can communicate input to a website when the site is not soliciting such information on the current page, but will do so on a subsequent page. Our solution approach makes generous use of program transformations (partial evaluation, currying, and slicing) to delay the site’s current solicitation for input until after the user’s out-of-turn input is processed. We illustrate how studying out-of-turn interaction through a generative lens leads to several valuable in-sights: (i) the concept of a web dialog, (ii) an improved understanding of web taxonomies, and (iii) new web interaction techniques and interfaces. These notions allow us to cast the design of interactive (and responsive) websites in terms of the underlying dialog structure and, further, suggest a simple implementation strategy with a clean separation of concerns. We also highlight new research directions opened up by the generative pro-gramming approach to interactive information retrieval such as the idea of web interaction axioms.
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