1,936 research outputs found

    First report and damage description of Calodesma collaris (Drury, 1782) (Lepidoptera: Erebidae) caterpillars on Aechmea winkleri Reitz, 1975 (Bromeliaceae).

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    We report for the first time the occurrence of Calodesma collaris (Drury, 1782) (Lepidoptera: Erebidae) caterpillars on Aechmea winkleri Reitz, 1975 (Bromeliaceae) and describe the damage it causes on these plants. The consumption of leaf tissue, accumulation of excrements and inhibition of inflorescence emission caused by larvae of C. collariscan result in plants of A. winkleri that are not suitable for ornamental or landscaping purposes

    Synthesis and biological evaluation of new natural phenolic (2E,4E,6E)-Octa-2,4,6-trienoic esters

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    In the present study the esterification of the OH groups of resveratrol, caffeic acid, ferulic acid, and -sitosterol with an antioxidant polyconjugated fatty acid, (2E,4E,6E)-octa-2,4,6-trienoic acid, was achieved. As the selective esterification of OH groups of natural compounds can affect their biological activity, a selective esterification of resveratrol and caffeic acid was performed by an enzymatic approach. The new resulting compounds were characterized spectroscopically (FT-IR, NMR mono, and bidimensional techniques); when necessary the experimental data were integrated by quantum chemical calculations. The antioxidant, anti-inflammatory and proliferative activity was evaluated. The good results encourage the use of these molecules as antioxidant and/or anti-inflammatory agents in dermocosmetic application

    Optical and X-ray Rest-frame Light Curves of the BAT6 sample

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    We present the rest-frame light curves in the optical and X-ray bands of an unbiased and complete sample of Swift long Gamma-Ray Bursts (GRBs), namely the BAT6 sample. The unbiased BAT6 sample (consisting of 58 events) has the highest level of completeness in redshift (\sim 95%), allowing us to compute the rest-frame X-ray and optical light curves for 55 and 47 objects, respectively. We compute the X-ray and optical luminosities accounting for any possible source of absorption (Galactic and intrinsic) that could affect the observed fluxes in these two bands. We compare the behaviour observed in the X-ray and in the optical bands to assess the relative contribution of the emission during the prompt and afterglow phases. We unarguably demonstrate that the GRBs rest-frame optical luminosity distribution is not bimodal, being rather clustered around the mean value Log(LR_{R}) = 29.9 ±\pm 0.8 when estimated at a rest frame time of 12 hr. This is in contrast with what found in previous works and confirms that the GRB population has an intrinsic unimodal luminosity distribution. For more than 70% of the events the rest-frame light curves in the X-ray and optical bands have a different evolution, indicating distinct emitting regions and/or mechanisms. The X-ray light curves normalised to the GRB isotropic energy (Eiso_{\rm iso}), provide evidence for X-ray emission still powered by the prompt emission until late times (\sim hours after the burst event). On the other hand, the same test performed for the Eiso_{\rm iso}-normalised optical light curves shows that the optical emission is a better proxy of the afterglow emission from early to late times.Comment: Accepted for publication in A&A: 10 pages, 5 figures, 2 table

    On the effect of Ti on Oxidation Behaviour of a Polycrystalline Nickel-based Superalloy

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    Titanium is commonly added to nickel superalloys but has a well-documented detrimental effect on oxidation resistance. The present work constitutes the first atomistic-scale quantitative measurements of grain boundary and bulk compositions in the oxide scale of a current generation polycrystalline nickel superalloy performed through atom probe tomography. Titanium was found to be particularly detrimental to oxide scale growth through grain boundary diffusion

    A complete sample of bright Swift short Gamma-Ray Bursts

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    We present a carefully selected sample of short gamma-ray bursts (SGRBs) observed by the Swift satellite up to June 2013. Inspired by the criteria we used to build a similar sample of bright long GRBs (the BAT6 sample), we selected SGRBs with favorable observing conditions for the redshift determination on ground, ending up with a sample of 36 events, almost half of which with a redshift measure. The redshift completeness increases up to about 70% (with an average redshift value of z = 0.85) by restricting to those events that are bright in the 15-150 keV Swift Burst Alert Telescope energy band. Such flux-limited sample minimizes any redshift-related selection effects, and can provide a robust base for the study of the energetics, redshift distribution and environment of the Swift bright population of SGRBs. For all the events of the sample we derived the prompt and afterglow emission in both the observer and (when possible) rest frame and tested the consistency with the correlations valid for long GRBs. The redshift and intrinsic X-ray absorbing column density distributions we obtain are consistent with the scenario of SGRBs originated by the coalescence of compact objects in primordial binaries, with a possible minor contribution (~10%-25%) of binaries formed by dynamical capture (or experiencing large natal kicks). This sample is expected to significantly increase with further years of Swift activity.Comment: 17 pages, 8 figures, 7 tables. Accepted for publication in MNRA

    Audio-Tactile Integration in Congenitally and Late Deaf Cochlear Implant Users

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    Several studies conducted in mammals and humans have shown that multisensory processing may be impaired following congenital sensory loss and in particular if no experience is achieved within specific early developmental time windows known as sensitive periods. In this study we investigated whether basic multisensory abilities are impaired in hearing-restored individuals with deafness acquired at different stages of development. To this aim, we tested congenitally and late deaf cochlear implant (CI) recipients, age-matched with two groups of hearing controls, on an audio-tactile redundancy paradigm, in which reaction times to unimodal and crossmodal redundant signals were measured. Our results showed that both congenitally and late deaf CI recipients were able to integrate audio-tactile stimuli, suggesting that congenital and acquired deafness does not prevent the development and recovery of basic multisensory processing. However, we found that congenitally deaf CI recipients had a lower multisensory gain compared to their matched controls, which may be explained by their faster responses to tactile stimuli. We discuss this finding in the context of reorganisation of the sensory systems following sensory loss and the possibility that these changes cannot be "rewired" through auditory reafferentation
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