238 research outputs found
Make it simple: mating behaviour of Euphydryas aurinia provincialis (Lepidoptera: Nymphalidae)
Courtship in butterflies can vary among species, from simple to elaborate displays, which are thought to promote conspecific mating and drive a female, at first unreceptive, to eventually mate. In this paper, we studied the courtship behaviour of a population of E. aurinia provincialis (Nymphalidae) of the Italian region Latium, finding clear differences in acceptance/refusal of females and in consequent departure/persistence of males. Despite the presence of a period of female unreceptivity after eclosion, virgin females usually do not show resistance, and accept to mate after a simple courtship. Once males meet a female, they immediately try to copulate clasping female genitalia, and proceed in mating performing long copulations. They also secrete a mating plug to prevent subsequent matings. On the contrary, already-mated females can strongly reject any approaching male and they always display Wide Wing fluttering, which is a behavioural pattern usually followed by male departure. In case of persistent males, prolonged and energy demanding sexual interactions, as Carrousels, can occur, with rare final copulation. Here, we analyse the effects of female refusal on male sexual behaviour and discuss potential selective pressures that might be acting on such behavioural traits
Is the alien species Clepsis peritana (Lepidoptera: Tortricidae) settling in Italy?
Clepsis peritana (Clemens, 1860) is a native species of North America that has been accidentally introduced in Europe in 80âs. This species was mentioned as occurring in Gibraltar, Spain, Denmark and Italy, but no precise collecting data were provided. The presence of the garden tortrix, Clepsis peritana, in Italy is confirmed by a single specimen collected in Central Italy (Umbria region) that is identified by both external characters and dissection of the male genitalia
Aspects of the planetary Birkhoff normal form
The discovery in [G. Pinzari. PhD thesis. Univ. Roma Tre. 2009], [L.
Chierchia and G. Pinzari, Invent. Math. 2011] of the Birkhoff normal form for
the planetary many--body problem opened new insights and hopes for the
comprehension of the dynamics of this problem. Remarkably, it allowed to give a
{\sl direct} proof of the celebrated Arnold's Theorem [V. I. Arnold. Uspehi
Math. Nauk. 1963] on the stability of planetary motions. In this paper, using a
"ad hoc" set of symplectic variables, we develop an asymptotic formula for this
normal form that may turn to be useful in applications. As an example, we
provide two very simple applications to the three-body problem: we prove a
conjecture by [V. I. Arnold. cit] on the "Kolmogorov set"of this problem and,
using Nehoro{\v{s}}ev Theory [Nehoro{\v{s}}ev. Uspehi Math. Nauk. 1977], we
prove, in the planar case, stability of all planetary actions over
exponentially-long times, provided mean--motion resonances are excluded. We
also briefly discuss perspectives and problems for full generalization of the
results in the paper.Comment: 44 pages. Keywords: Averaging Theory, Birkhoff normal form,
Nehoro{\v{s}}ev Theory, Planetary many--body problem, Arnold's Theorem on the
stability of planetary motions, Properly--degenerate kam Theory, steepness.
Revised version, including Reviewer's comments. Typos correcte
Closed quantum subgroups of locally compact quantum groups
We investigate the fundamental concept of a closed quantum subgroup of a
locally compact quantum group. Two definitions - one due to S.Vaes and one due
to S.L.Woronowicz - are analyzed and relations between them discussed. Among
many reformulations we prove that the former definition can be phrased in terms
of quasi-equivalence of representations of quantum groups while the latter can
be related to an old definition of Podle\'s from the theory of compact quantum
groups. The cases of classical groups, duals of classical groups, compact and
discrete quantum groups are singled out and equivalence of the two definitions
is proved in the relevant context. A deep relationship with the quantum group
generalization of Herz restriction theorem from classical harmonic analysis is
also established, in particular, in the course of our analysis we give a new
proof of Herz restriction theorem.Comment: 24 pages, v3 adds another reference. The paper will appear in
Advances in Mathematic
Fungal infections and Cultural Heritage: An alternative approach for VOCs analysis applied in indoor environment
Metabolic synergies in the biotransformation of organic and metallic toxic compounds by a saprotrophic soil fungus
The saprotrophic fungus Penicillium griseofulvum was chosen as model organism to study responses to a mixture of hexachlorocyclohexane (HCH) isomers (α-HCH, ÎČ-HCH, Îł-HCH, ÎŽ-HCH) and of potentially toxic metals (vanadium, lead) in solid and liquid media. The P. griseofulvum FBL 500 strain was isolated from polluted soil containing high concentrations of HCH isomers and potentially toxic elements (Pb, V). Experiments were performed in order to analyse the tolerance/resistance of this fungus to xenobiotics, and to shed further light on fungal potential in inorganic and organic biotransformations. The aim was to examine the ecological and bioremedial potential of this fungus verifying the presence of mechanisms that allow it to transform HCH isomers and metals under different, extreme, test conditions. To our knowledge, this work is the first to provide evidence on the biotransformation of HCH mixtures, in combination with toxic metals, by a saprotrophic non-white-rot fungus and on the metabolic synergies involved
Contribution of the Microbial Communities Detected on an Oil Painting on Canvas to Its Biodeterioration
In this study, we investigated the microbial community (bacteria and fungi) colonising an oil painting on canvas, which showed visible signs of biodeterioration. A combined strategy, comprising culture-dependent and -independent techniques, was selected. The results derived from the two techniques were disparate. Most of the isolated bacterial strains belonged to related species of the phylum Firmicutes, as Bacillus sp. and Paenisporosarcina sp., whereas the majority of the non-cultivable members of the bacterial community were shown to be related to species of the phylum Proteobacteria, as Stenotrophomonas sp. Fungal communities also showed discrepancies: the isolated fungal strains belonged to different genera of the order Eurotiales, as Penicillium and Eurotium, and the non-cultivable belonged to species of the order Pleosporales and Saccharomycetales. The cultivable microorganisms, which exhibited enzymatic activities related to the deterioration processes, were selected to evaluate their biodeteriorative potential on canvas paintings; namely Arthrobacter sp. as the representative bacterium and Penicillium sp. as the representative fungus. With this aim, a sample taken from the painting studied in this work was examined to determine the stratigraphic sequence of its cross-section. From this information, âmock paintings,â simulating the structure of the original painting, were prepared, inoculated with the selected bacterial and fungal strains, and subsequently examined by micro-Fourier Transform Infrared spectroscopy, in order to determine their potential susceptibility to microbial degradation. The FTIR-spectra revealed that neither Arthrobacter sp. nor Penicillium sp. alone, were able to induce chemical changes on the various materials used to prepare âmock paintings.â Only when inoculated together, could a synergistic effect on the FTIR-spectra be observed, in the form of a variation in band position on the spectrum.The FTIR analyses performed in this study were financed by the Junta de AndalucĂa (RNM-325 group). The molecular analyses performed in this study were financed by the Austrian Science Fund (FWF) project âHertha-Firnberg T137â and the Spanish Ministry of Science and Innovation (Project CTQ2008-06727-C03-03). G. Piñar also thanks the âElise-Richter V194-B20â projects
Wettability Modification of Nanomaterials by Low-Energy Electron Flux
Controllable modification of surface free energy and related properties (wettability, hygroscopicity, agglomeration, etc.) of powders allows both understanding of fine physical mechanism acting on nanoparticle surfaces and improvement of their key characteristics in a number of nanotechnology applications. In this work, we report on the method we developed for electron-induced surface energy and modification of basic, related properties of powders of quite different physical origins such as diamond and ZnO. The applied technique has afforded gradual tuning of the surface free energy, resulting in a wide range of wettability modulation. In ZnO nanomaterial, the wettability has been strongly modified, while for the diamond particles identical electron treatment leads to a weak variation of the same property. Detailed investigation into electron-modified wettability properties has been performed by the use of capillary rise method using a few probing liquids. Basic thermodynamic approaches have been applied to calculations of components of solidâliquid interaction energy. We show that defect-free, low-energy electron treatment technique strongly varies elementary interface interactions and may be used for the development of new technology in the field of nanomaterials
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