748 research outputs found

    Observaciones sobre las madrigueras y comportamiento enterrador de Brachynotus gemmellari y otras especies de los fondos de Squilla en Ancona, Adriático Central

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    The paper presents information on the burrows of a number of species that occur on Squilla grounds in the coastal Adriatic off Ancona, Italy. The burrows and burrowing behaviour of Brachynotus gemmellari are described for the first time. For Upogebia tipica, Solecurtus strigilatus and Gobius niger, the observations add to sparse burrow information in the literature. Little is known of the burrows of Echiura in the Mediterranean: those of two species are briefly described from surface features.Este trabajo presenta información sobre las madrigueras de diversas especies presentes en los fondos de Squilla en las costas de Ancona, Italia, en el Adriático central. Se describen por vez primera las madrigueras y el comportamiento excavador de Brachynotus gemmellari. En el caso de Upogebia tipica, Solecurtus strigilatus y Gobius niger, las presentes observaciones se añaden a información dispersa sobre las madrigueras de Echiura en el Mediterráneo: se describen brevemente las de dos especies a partir de características de la superfície

    Measuring primordial gravitational waves from CMB B-modes in cosmologies with generalized expansion histories

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    We evaluate our capability to constrain the abundance of primordial tensor perturbations in cosmologies with generalized expansion histories in the epoch of cosmic acceleration. Forthcoming satellite and sub-orbital experiments probing polarization in the CMB are expected to measure the B-mode power in CMB polarization, coming from PGWs on the degree scale, as well as gravitational lensing on arcmin scales; the latter is the main competitor for the measurement of PGWs, and is directly affected by the underlying expansion history, determined by the presence of a DE component. In particular, we consider early DE possible scenarios, in which the expansion history is substantially modified at the epoch in which the CMB lensing is most relevant. We show that the introduction of a parametrized DE may induce a variation as large as 30% in the ratio of the power of lensing and PGWs on the degree scale. We find that adopting the nominal specifications of upcoming satellite measurements the constraining power on PGWs is weakened by the inclusion of the extra degrees of freedom, resulting in a reduction of about 10% of the upper limits on r in fiducial models with no GWs, as well as a comparable increase in the error bars in models with non-zero r. Moreover, we find that the inclusion of sub-orbital CMB experiments, capable of mapping the B-mode power up to the angular scales affected by lensing, can restore the forecasted performances with a cosmological constant. Finally, we show how the combination of CMB data with Type Ia SNe, BAO and Hubble constant allows to constrain simultaneously r and the DE quantities in the parametrization we consider, consisting of present abundance and first redshift derivative of the energy density. We compare this study with results obtained using the forecasted lensing potential measurement precision from CMB satellite observations, finding consistent results.Comment: 17 pages, 9 figures, accepted for publication by JCAP. Modified version after the referee's comment

    Diaqua­bis(2-chloro­benzoato-κO)bis­(N,N-diethyl­nicotinamide-κN 1)manganese(II)

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    In the monomeric title complex, [Mn(C7H4ClO2)2(C10H14N2O)2(H2O)2], the MnII atom is located on a crystallographic centre of inversion. The asymmetric unit contains one 2-chloro­benzoate (CB) ligand, one diethyl­nicotinamide (DENA) ligand and one coordinated water mol­ecule, all ligands being monodentate. The four O atoms in the equatorial plane around the Mn atom form a slightly distorted square-planar arrangement, while the slightly distorted octa­hedral coordination is completed by the two pyridine N atoms of the DENA ligands in the axial positions. The dihedral angle between the carboxyl group and the adjacent benzene ring is 77.9 (11)°, while the pyridine and benzene rings are oriented at a dihedral angle of 45.94 (5)°. In the crystal structure, inter­molecular O—H⋯O hydrogen bonds link the mol­ecules into infinite chains

    Crude incidence in two-phase designs in the presence of competing risks.

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    BackgroundIn many studies, some information might not be available for the whole cohort, some covariates, or even the outcome, might be ascertained in selected subsamples. These studies are part of a broad category termed two-phase studies. Common examples include the nested case-control and the case-cohort designs. For two-phase studies, appropriate weighted survival estimates have been derived; however, no estimator of cumulative incidence accounting for competing events has been proposed. This is relevant in the presence of multiple types of events, where estimation of event type specific quantities are needed for evaluating outcome.MethodsWe develop a non parametric estimator of the cumulative incidence function of events accounting for possible competing events. It handles a general sampling design by weights derived from the sampling probabilities. The variance is derived from the influence function of the subdistribution hazard.ResultsThe proposed method shows good performance in simulations. It is applied to estimate the crude incidence of relapse in childhood acute lymphoblastic leukemia in groups defined by a genotype not available for everyone in a cohort of nearly 2000 patients, where death due to toxicity acted as a competing event. In a second example the aim was to estimate engagement in care of a cohort of HIV patients in resource limited setting, where for some patients the outcome itself was missing due to lost to follow-up. A sampling based approach was used to identify outcome in a subsample of lost patients and to obtain a valid estimate of connection to care.ConclusionsA valid estimator for cumulative incidence of events accounting for competing risks under a general sampling design from an infinite target population is derived

    Analysis of tourism in Campania as a tool for the development of high-quality cultural services for sightseers: The “Reale Osservatorio Vesuviano” case history

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    The purpose of this work is to identify the guidelines for the development and diversification of the cultural touristic offer achievable at the Reale Osservatorio Vesuviano (ROV). Founded in 1841, it is the oldest volcano observatory in the world and it has always had the vocation for scientific-naturalistic and formative tourism. The present study investigates the connections between the sociology of tourism and the ROV’s sustainability and competitiveness as a tourist destination. Here it is performed a study of the tourist flow, based on the sociology of tourism and on the correct processing of data sets, distinguishing the ''statistical information on tourism" from "tourism statistics", as such a study is the basis of a proper market strategy in different sectors. Tourism remains, in fact, an important phenomenon in world economy: despite the economic crisis of recent years, international tourist arrivals show a positive development of the trend in all the major sub-areas into which the large international areas are traditionally divided. The principles for a future marketing plan were outlined after collecting all the relevant information. The plan was designed to enhance the overall touristic offer of the ROV, never ceasing to consider the integration of natural- scientific aspects and cultural events to be offered within the observatory itself.Published64-872TM. Divulgazione Scientifica6TM. Poli Museali1VV. AltroN/A or not JC

    Pseudo-single crystal electrochemistry on polycrystalline electrodes : visualizing activity at grains and grain boundaries on platinum for the Fe2+/Fe3+ redox reaction

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    The influence of electrode surface structure on electrochemical reaction rates and mechanisms is a major theme in electrochemical research, especially as electrodes with inherent structural heterogeneities are used ubiquitously. Yet, probing local electrochemistry and surface structure at complex surfaces is challenging. In this paper, high spatial resolution scanning electrochemical cell microscopy (SECCM) complemented with electron backscatter diffraction (EBSD) is demonstrated as a means of performing ‘pseudo-single-crystal’ electrochemical measurements at individual grains of a polycrystalline platinum electrode, while also allowing grain boundaries to be probed. Using the Fe2+/3+ couple as an illustrative case, a strong correlation is found between local surface structure and electrochemical activity. Variations in electrochemical activity for individual high index grains, visualized in a weakly adsorbing perchlorate medium, show that there is higher activity on grains with a significant (101) orientation contribution, compared to those with (001) and (111) contribution, consistent with findings on single-crystal electrodes. Interestingly, for Fe2+ oxidation in a sulfate medium a different pattern of activity emerges. Here, SECCM reveals only minor variations in activity between individual grains, again consistent with single-crystal studies, with a greatly enhanced activity at grain boundaries. This suggests that these sites may contribute significantly to the overall electrochemical behavior measured on the macroscale

    Search for Slowly Moving Magnetic Monopoles with the MACRO Detector

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    A search for slowly moving magnetic monopoles in the cosmic radiation was conducted from October 1989 to November 1991 using the large liquid scintillator detector subsystem of the first supermodule of the MACRO detector at the Gran Sasso underground laboratory. The absence of candidates established an upper limit on the monopole flux of 5.6 × 10^(−15) cm^(−2) sr^(−1) s^(−1) at 90% confidence level in the velocity range of 10^(−4)≲β<4×10^(−3). This result places a new constraint on the abundance of monopoles trapped in our solar system

    Gold nanoparticle-polymer nanocomposites synthesized by room temperature atmospheric pressure plasma and their potential for fuel cell electrocatalytic application

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    Conductive polymers have been increasingly used as fuel cell catalyst support due to their electrical conductivity, large surface areas and stability. The incorporation of metal nanoparticles into a polymer matrix can effectively increase the specific surface area of these materials and hence improve the catalytic efficiency. In this work, a nanoparticle loaded conductive polymer nanocomposite was obtained by a one-step synthesis approach based on room temperature direct current plasmaliquid interaction. Gold nanoparticles were directly synthesized from HAuCl4 precursor in poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS). The resulting AuNPs/PEDOT: PSS nanocomposites were subsequently characterized under a practical alkaline direct ethanol fuel cell operation condition for its potential application as an electrocatalyst. Results show that AuNPs sizes within the PEDOT: PSS matrix are dependent on the plasma treatment time and precursor concentration, which in turn affect the nanocomposites electrical conductivity and their catalytic performance. Under certain synthesis conditions, unique nanoscale AuNPs/PEDOT: PSS core-shell structures could also be produced, indicating the interaction at the AuNPs/polymer interface. The enhanced catalytic activity shown by AuNPs/PEDOT: PSS has been attributed to the effective electron transfer and reactive species diffusion through the porous polymer network, as well as the synergistic interfacial interaction at the metal/polymer and metal/metal interfaces.Funding Agencies|UK EPSRC [EP/K022237/1, EP/M024938/1, EP/P00394X/1, EP/I013229/1]; National Natural Science Foundation of China [51203135]; InvestNI [PoC-325]; Department of Employment Learning; EU-COST Action [TD1208]</p
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