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Il saggio prende in esame le modalità di rappresentazione dello sport nei libri di Meneghello (registri espressivi, procedimenti narrativi e stilistici) e i significati che l’autore allo sport attribuisce: occasione per saggiare la volontà, occasione per l’io di misurare se stesso e gli altri; rivelatore di una civiltà; metafora per veicolare riflessioni esistenziali, sulla conoscenza, sulla formazione. L’intervento è completato dall’analisi del progetto di un libro, intitolato “Spor”, inedito, conservato fra le carte dello scrittore

Introduction. A cross-sectional study was undertaken to deter- mine the prevalence of Giardia and Cryptosporidium in calves of Palermo area (Sicily) and to evaluate the occupational risk associated with occurrence of zoonotic genotypes. Methods. A total of 217 faecal samples, from 149 calves (between 2 and 240 days of age) and 68 farmers, were collected in 19 cattle- farms of Palermo area. A questionnaire regarding demographic characteristics and personal hygienic measures was submitted to all farmers. All faecal samples were analyzed by Immunoflu- orescence assay and Polimerase Chain Reaction (PCR); geno- types were determined by DNA sequencing of Triose Phosphate Isomerase gene for Giardia and Small Subunit Ribosomal RNA gene for Cryptosporidium. Results. None farmer tested was positive for Giardia and Cryptosporidium, whereas these protozoa were respectively detected in 53 (including 5 with zoonotic G. duodenalis geno- type A) and 17 (of which 1 with zoonotic C. ubiquitum) of the examined calves. Discussion. The results indicate that the risk of transmitting both protozoa to farmers in Palermo area is negligible although it can- not be considered null because of identification of human geno- types/species in calves.

Kawasaki syndrome (KS) typically strikes children younger than age 5 and presents with persistent high fever for at least 5 days combined with a heterogeneous polymorphous rash, extremity abnormalities, oropharyngitis, non-exudative conjunctivitis and cervical lymphadenitis. Treatment with high-dose intravenous immunoglobulin reduces substantially the risk of potential cardiovascular complications. For the first time, we report a child presenting all the clinical symptoms of KS, which recurred for 4 times in a period of 33 months. Each relapse was characterized by obstinate high fever combined with mucocutaneous signs and was each time successfully treated with intravenous immunoglobulin without the occurrence of any cardiovascular damage.

We report on a fundamentally new radiation phenomenon in nanostructures: emission of spatially coherent and spectrally narrow-band light driven by localized injection of free electrons into a planar plasmonic metamaterial. In 'coherent' metamaterials, where interactions among the meta-molecules are strong, an electron beam can generate a synchronized, in-phase response across a large number of meta-molecules leading to threshold-free emission of spatially coherent light propagating perpendicular to the metamaterial.In a laser coherence is derived from the bosonic statistics of photons, the resonant properties of the laser cavity and the collective nature of stimulated emission in the gain medium, and a threshold level of input energy is required to maintain the gain and overcome losses. Here we show experimentally that a scalable low-divergence, threshold-free optical source can be constructed on the basis of a collectively oscillating optical nano-antenna array formed by the metamaterial wherein coherence is provided not by the feed (as in conventional microwave antenna arrays) but via the strong mutual interactions among the nano-antennas.

For all living organisms, copper (Cu) is an essential micronutrient taking part, with its redox chemistry, to several metabolic and regulatory cellular events. However, the same redox properties that make Cu essential are responsible for its toxicity. Indeed, Cu participates in reactions that generate Reactive Oxygen Species (ROS). ROS target main cellular macromolecules (proteins, lipids, DNA and RNA), leading to cellular dysfunctions and in the extreme case, to cell death. All living organisms evolved molecular mechanisms for Cu homeostasis. Indeed, uptake, transport and detoxification systems that actively prevent both Cu deficiency and poisoning are well conserved along the phylogenetic tree. Among eukaryotes, these mechanisms have been mainly investigated in the yeast Saccharomyces cerevisiae used as a model organism. Evolutionary engineering is a rational approach that uses the evolutionary principles to direct the selection of organisms with a desired set of phenotypes, allowing for the improvement of microbial properties. This approach can be exploited to obtain Cu-tolerant and Cu-accumulating yeast cells, with potential application in nutraceutics, as nutritional supplements, as well as in bioremediation, for the removal or recovery of metal ions. At the same time, evolutionary engineering is a valuable strategy to gain more insight into the molecular aspects of Cu tolerance in microbial cells. In the present work is described an evolutionary engineering strategy to improve Cu tolerance of natural yeasts. Strains of Saccharomyces cerevisiae and of Candida humilis originally endowed with different sensitivity and tolerance toward Cu have been exposed to increasing concentrations of Cu during cell cultivation in liquid medium. This treatment stably improved Cu tolerance of all strains. One evolved strain for each yeast species was then chosen to analyze in detail the physiological response to Cu. Compared with the original Cu-sensitive strains the two evolved

In living organisms, copper (Cu) contributes to essential functions but at high concentrations it may elicit toxic effects. Cu-tolerant yeast strains are of relevance for both biotechnological applications and studying physiological and molecular mechanisms involved in stress resistance. One way to obtain tolerant strains is to exploit experimental methods that rely on the principles of natural evolution (evolutionary engineering) and allow for the development of complex phenotypic traits. However, in most cases, the molecular and physiological basis of the phenotypic changes produced have not yet been unravelled. We investigated the determinants of Cu resistance in a Saccharomyces cerevisiae strain that was evolved to tolerate up to 2.5 g CuSO4 l”1 in the culture medium. We found that the content of intracellular Cu and the expression levels of several genes encoding proteins involved in Cu metabolism and oxidative stress response were similar in the Cu-tolerant (evolved ) and the Cu-sensitive (non-evolved ) strain. The major difference detected in the two strains was the copy number of the gene CUP1, which encodes a metallothionein. In evolved cells, a sevenfold amplification of CUP1 was observed, accounting for its strongly and steadily increased expression. Our results implicate CUP1 in protection of the evolved S. cerevisiae cells against Cu toxicity. In these cells, robustness towards Cu is stably inheritable and can be reproducibly selected by controlling environmental conditions. This finding corroborates the effectiveness of laboratory evolution of whole cells as a tool to develop microbial strains for biotechnological applications

Background: Yeast strains endowed with robustness towards copper and/or enriched in intracellular Cu might find application in biotechnology processes, among others in the production of functional foods. Moreover, they can contribute to the study of human diseases related to impairments of copper metabolism. In this study, we investigated the molecular and physiological factors that confer copper tolerance to strains of baker's yeasts. Results: We characterized the effects elicited in natural strains of Candida humilis and Saccharomyces cerevisiae by the exposure to copper in the culture broth. We observed that, whereas the growth of Saccharomyces cells was inhibited already at low Cu concentration, C. humilis was naturally robust and tolerated up to 1 g . L-1 CuSO4 in the medium. This resistant strain accumulated over 7 mg of Cu per gram of biomass and escaped severe oxidative stress thanks to high constitutive levels of superoxide dismutase and catalase. Both yeasts were then "evolved" to obtain hyper-resistant cells able to proliferate in high copper medium. While in S. cerevisiae the evolution of robustness towards Cu was paralleled by the increase of antioxidative enzymes, these same activities decreased in evolved hyper-resistant Candida cells. We also characterized in some detail changes in the profile of copper binding proteins, that appeared to be modified by evolution but, again, in a different way in the two yeasts. Conclusions: Following evolution, both Candida and Saccharomyces cells were able to proliferate up to 2.5 g .L-1 CuSO4 and to accumulate high amounts of intracellular copper. The comparison of yeasts differing in their robustness, allowed highlighting physiological and molecular determinants of natural and acquired copper tolerance. We observed that different mechanisms contribute to confer metal tolerance: the control of copper uptake, changes in the levels of enzymes involved in oxidative stress response and changes in the copper-binding pro

Imaging localized plasmon modes in noble-metal nanoparticles is of fundamental importance for applications such as ultrasensitive molecular detection. Here, we demonstrate the combined use of optical dark-field microscopy (DFM), cathodoluminescence (CL), and electron energy-loss spectroscopy (EELS) to study localized surface plasmons on individual gold nanodecahedra. By exciting surface plasmons with either external light or an electron beam, we experimentally resolve a prominent dipole-active plasmon band in the far-field radiation acquired via DFM and CL, whereas EELS reveals an additional plasmon mode associated with a weak dipole moment. We present measured spectra and intensity maps of plasmon modes in individual nanodecahedra in excellent agreement with boundary-element method simulations, including the effect of the substrate. A simple tight-binding model is formulated to successfully explain the rich plasmon structure in these particles encompasing bright and dark modes, which we predict to be fully observable in less lossy silver decahedra. Our work provides useful insight into the complex nature of plasmon resonances in nanoparticles with pentagonal symmetry. © 2012 American Chemical Society.

A pair of coupled gold nanorods excited by a beam of free electrons acts as a transmitting Hertzian antenna in the optical part of the spectrum. Significantly enhanced resonant emission is observed from the antenna when the electron beam is injected around the junction between the rods, where the local density of electromagnetic states is elevated. © 2010 American Chemical Society.

A pair of coupled gold nanorods excited by a beam of free electrons acts as a transmitting Hertzian antenna in the optical part of the spectrum. Significantly enhanced resonant emission is observed from the antenna when the electron beam is injected around the junction between the rods, where the local density of electromagnetic states is elevated. © 2010 American Chemical Society.

The passage of a free-electron beam through a nanohole in a periodically layered metal-dielectric structure creates a new type of tunable, nanoscale radiation source-a >light well>. In the reported demonstration, tunable light is generated at an intensity of ∼200W/cm2 as electrons with energies in the 20-40keV range are injected into gold-silica well structures with a lateral size of just a few hundred nanometers. © 2009 The American Physical Society.