2,752 research outputs found

    Naturalization and spread of the alien species Ozognathus cornutus (LeConte, 1859) (Coleoptera: Ptinidae: Ernobiinae) in Italy

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    Ozognathus cornutus (LeConte, 1859) (Coleoptera: Ptinidae: Ernobiinae), species native to North America, is a saproxylophagous species and is known to feed on decaying tissues within conspicuous galls and on vegetal decaying organic material such as dried fruits or small wood shavings and insect excrements in galleries made by other woodboring species. A few years after the first record in 2011, its naturalization in Italy is here reported. The insect was found as successor in galls of Psectrosema tamaricis (Diptera Cecidomyiidae), Plagiotrochus gallaeramulorum, Andricus multiplicatus and Synophrus politus (Hymenoptera Cynipidae). The galls seem to have played an important ecological role in speeding up the naturalization process. The lowest proportion of galls used by O. cornutus was recorded for P. tamaricis (23%), the only host belonging to Cecidomyiidae, while the percentages recorded for the other host species, all Cynipidae forming galls on oaks, were higher: 43.6%, 61.1% and 76.9% in A multiplicatus, S. politus and P. gallaeramulorum, respectively. Although O. cornutus is able to exploit other substrates like dried fruits and vegetables, for which it could represent a potential pest, it prefers to live as a successor in woody and conspicuous galls, which thus can represent a sort of natural barrier limiting the possible damages to other substrates

    Implications of multiple high-redshift galaxy clusters

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    To date, 14 high-redshift (z>1.0) galaxy clusters with mass measurements have been observed, spectroscopically confirmed and are reported in the literature. These objects should be exceedingly rare in the standard LCDM model. We conservatively approximate the selection functions of these clusters' parent surveys, and quantify the tension between the abundances of massive clusters as predicted by the standard LCDM model and the observed ones. We alleviate the tension considering non-Gaussian primordial perturbations of the local type, characterized by the parameter fnl and derive constraints on fnl arising from the mere existence of these clusters. At the 95% confidence level, fnl>467 with cosmological parameters fixed to their most likely WMAP5 values, or fnl > 123 (at 95% confidence) if we marginalize over WMAP5 parameters priors. In combination with fnl constraints from Cosmic Microwave Background and halo bias, this determination implies a scale-dependence of fnl at approx. 3 sigma. Given the assumptions made in the analysis, we expect any future improvements to the modeling of the non-Gaussian mass function, survey volumes, or selection functions to increase the significance of fnl>0 found here. In order to reconcile these massive, high-z clusters with an fnl=0, their masses would need to be systematically lowered by 1.5 sigma or the sigma8 parameter should be approx. 3 sigma higher than CMB (and large-scale structure) constraints. The existence of these objects is a puzzle: it either represents a challenge to the LCDM paradigme or it is an indication that the mass estimates of clusters is dramatically more uncertain than we think.Comment: 11 pages, 7 figures, modified to match published versio

    Evolution of the decay mechanisms in central collisions of XeXe + SnSn from E/AE/A = 8 to 29 MeVMeV

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    Collisions of Xe+Sn at beam energies of E/AE/A = 8 to 29 MeVMeV and leading to fusion-like heavy residues are studied using the 4Ï€4\pi INDRA multidetector. The fusion cross section was measured and shows a maximum at E/AE/A = 18-20 MeVMeV. A decomposition into four exit-channels consisting of the number of heavy fragments produced in central collisions has been made. Their relative yields are measured as a function of the incident beam energy. The energy spectra of light charged particles (LCP) in coincidence with the fragments of each exit-channel have been analyzed. They reveal that a composite system is formed, it is highly excited and first decays by emitting light particles and then may breakup into 2- or many- fragments or survives as an evaporative residue. A quantitative estimation of this primary emission is given and compared to the secondary decay of the fragments. These analyses indicate that most of the evaporative LCP precede not only fission but also breakup into several fragments.Comment: Invited Talk given at the 11th International Conference on Nucleus-Nucleus Collisions (NN2012), San Antonio, Texas, USA, May 27-June 1, 2012. To appear in the NN2012 Proceedings in Journal of Physics: Conference Series (JPCS

    Constraints on the equation of state of dark energy and the Hubble constant from stellar ages and the CMB

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    We place tight constraints on the redshift-averaged, effective value of the equation of state of dark energy, w, using only the absolute ages of Galactic stars and the observed position of the first peak in the angular power spectrum of the CMB. We find w<-0.8 at the 68% confidence level. If we further consider that w > -1, this finding suggests that within our uncertainties, dark energy is indistinguishable from a classical vacuum energy term. We detect a correlation between the ages of the oldest galaxies and their redshift. This opens up the possibility of measuring w(z) by computing the relative ages of the oldest galaxies in the universe as a function of redshift, dz/dt. We show that this is a realistic possibility by computing dz/dt at z~0 from SDSS galaxies and obtain an independent estimate for the Hubble constant, H_0 = 69 \pm 12 km s-1 Mpc-1. The small number of galaxies considered at z>0.2 does not yield, currently, a precise determination of w(z), but shows that the age--redshift relation is consistent with a Standard LCDM universe with w=−1w=-1.Comment: Submitted to Ap

    Simulação da Produção de Cupuaçu (Theobroma grandiflorum) e Pupunha (Bactris gasipaes) em Sistemas Agroflorestais Utilizando Modelos de Dinâmica de Sistemas.

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    FIRST RECORD IN EUROPE OF SEEDLINGS OF FICUS MACROPHYLLA F. COLUMNARIS (Moraceae) AND OF ITS POLLINATING WASP PLEISTODONTES CF. IMPERIALIS (Chalcidoidea Agaonidae)

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    Since the first half of the nineteenth century, several Ficus species have been introduced into Italy as ornamental trees throughout urban gardens and along urban roads. Because a relationship with an agaonid wasp is essential for the pollination and consequently for the production of fertile seeds of Ficus spp., the seedlings of other introduced fig species (Ficus microcarpa L. f., Ficus rubiginosa Desf. ex Vent. and Ficus watkinsiana F.M. Bailey) weren’t found in Europe in conjunction with their pollinating wasps until more than a century after the figs’ introduction. This study presents the first recorded observation of Ficus macrophylla f. columnaris (C. Moore) D. J. Dixon seedlings in Europe. The seedlings grew from fertile seeds pollinated by the Agaonid Pleistodontes cf. imperialis. As no other F. macrophylla seedlings have been found in any of the other historical gardens of Palermo where this species is present in spite of the occurrence of mature figs fruits, it is possible that the cracks of the terrace filled with soil and organic material where the plantlets were found could have created favorable microclimatic conditions quite similar to those that characterize the native distri- bution areas of this species

    Análise financeira de sistemas produtivos integrados.

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    Andricus cydoniae Giraud, 1859 Junior Synonym of Cynips coni-fica Hartig, 1843, as Experimentally Demonstrated (Hymenoptera: Cynipidae: Cynipini)

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    We demonstrated the life cycle closure of Cynips conifica Hartig, 1843 (presently Andricus conifi-cus), previously supposed on the basis of molecular data, and the identity of the sexual genera-tion, through laboratory experiments. As a consequence, Andricus cydoniae Giraud, 1859 became a junior synonym of A. conificus (Hartig, 1843). We provide illustrations and a diagnosis for adults and galls, observations on biology, and information on distribution. Moreover, as sexual galls of A. conificus cannot be distinguished from those of Andricus multiplicatus, a detailed com-parison between sexual galls and adults of these two species is reported

    Operational Solution to the Nonlinear Klein-Gordon Equation

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    Supported by Grant SEP-CONACYT 220603, the first author was supported by SEP-PRODEP through the project UAM-PTC-630, the third author was supported by Portuguese National Funds through the FCT Foundation for Science and Technology under the project PEst-UID/EEA/00066/2013We obtain solutions of the nonlinear Klein-Gordon equation using a novel operational method combined with the Adomian polynomial expansion of nonlinear functions. Our operational method does not use any integral transforms nor integration processes. We illustrate the application of our method by solving several examples and present numerical results that show the accuracy of the truncated series approximations to the solutions.authorsversionpublishe
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