Dante nelle letterature straniere

Il volume offre un incrocio di sguardi critici sulle rotte percorse dall’opera dantesca nelle letterature straniere. A settecento anni dalla sua morte, la voce di Dante continua a oltrepassare confini permeando immaginari lontani, in un incedere di evocazioni, traduzioni, interpretazioni e riscritture. I venti saggi qui presentati tratteggiano un itinerario di esplorazione delle tracce dantesche nelle tradizioni letterarie di Albania, Svezia, Francia, Cuba, Polonia, Stati Uniti, Germania, Argentina, Danimarca, Scozia, Inghilterra e Messico. Le diverse latitudini abbracciate si articolano in una raccolta di studi che dall’epoca moderna confluisce nell’estremo contemporaneo, calibrando nuovi orizzonti e prospettive nello sconfinato territorio della critica dantesca. Gli autori e le autrici illuminano storie di ricezione, riletture e dialoghi intertestuali nei quali la memoria della Commedia si riconfigura in un’inesauribile pluralità di scritture, di cui si intende consegnare in queste pagine uno sguardo di carattere esplorativo e non antologico. La parola di Dante attraversa lingue e universi letterarioculturali senza tradirsi ma conoscendo nuove fioriture: confermandosi una parola necessaria, profetica e viva

Morphology and secretion of glandular trichomes in Tamus communis

Light and scanning electron microscopical investigations were carried out to study distribution, morphology and secretion of glandular trichomes during leaf development in Tamus communis. During leaf growth glandular trichomes arise continously from single protodermal cells. At maturity, they are composed of a 6-celled gland head, a secretory neck cell, an \u201cendodermal\u201d cell, and one basal or reservoir cell. During the early stage of secretion, several regularly arranged crater-like pores differentiate on the cuticular surface of the gland head. Through these pores (1\u20131.5 \u3bcm in diameter), the secretion flows out as a thin film or as rods (0.4 \u3bcm in diameter) spreading on the trichomes and on the leaf surface. Histochemical tests indicate that the secretion is composed of a small amount of carbohydrates and an abundant fraction of lipophilic material. Proceeding towards senescence, the wall degeneration of the gland head gives rise to a strong histochemical reaction for insoluble polysaccharides. The results presented are compared with those of other investigations on the pattern of secretion in glandular trichomes

Human contribution to trace elements in urban areas as measured in holm oak (Quercus ilex L.) bark

The effect of human activities on the presence of trace elements in the atmosphere was evaluated by analyzing samples of holm oak bark, collected in Italy in a large city, in a small town, and in a reference area, scarcely inhabited. In all cases, point sources of pollution were excluded (e.g., industries and incinerators). The concentrations of As, Cd, Co, Cu, Fe, Mn, Ni, Pb, V, and Zn were measured using inductively coupled plasma optical emission spectrometry (ICP-OES). The element concentrations in the small town are not different from the reference area, except for Pb and Cu, while the samples collected in the large city show higher concentrations of Co, Cu, Fe, Ni, Pb, V, and Zn with respect to the rural area. In particular, the Pb levels in the large city are approximately 16 times higher than in the reference site, and five times higher than in the small town. Most element concentrations are correlated in the large city, while in the reference site, only a few significant correlations between elements were found. Even in the absence of specific sources of pollution, populations living in big cities are exposed to higher concentrations of trace elements than those living in rural environments or in small urban centers

Assessing photosynthetic biomarkers in lichen transplants exposed under different light regimes

tThe present work is a methodological study testing alternative exposure conditions of lichen transplantsfor biomonitoring studies. We evaluated the effects of different light regime on the vitality of lichenby analysing the photosynthetic efficiency of transplanted thalli of the fruticose species Pseudeverniafurfuracea (L.) Zopf. var. furfuracea. In particular, we tested the hypothesis that shading lichen transplantsis necessary to ensure sufficient lichen vitality during the exposure time. Thalli of P. furfuracea wereexposed in a polluted area within the harbour of Genoa (N-Italy) for 4 weeks under two experimentalconditions: 5 thalli were covered with a shade cloth, whereas 5 thalli were kept in the light. We showedthat, under the same environmental conditions (i.e., climate and pollution regime), shading the thalliminimised the photoinhibition and prolonged the vitality of the lichen. Thus, we recommend shadinglichen transplants during biomonitoring surveys to better detect the effects of pollution on the lichens