836 research outputs found
Phenomenology and Semiotics. Crossing Perspectives.
In recent years the study of relationships between semiotics and
phenomenology seems to be entering a period of renewed vitality and
creativity (CADIOT & VISETTI 2001; ROSENTHAL & VISETTI 2008; 2010; PIOTROWSKI
2009; FONTANILLE 2008; BONDĂŚ 2012). For a variety of theoretical and historical
reasons, there has been a constant osmosis between phenomenological and
semiotic methods. In short, on one side, the works and investigations of
phenomenologists have provided essential tools to semiotics. To give just an
example: the greimasian semiotics theory refers to the process of meaning
formation in terms of perceptual apprehension thanks to his original recovery
of Merleau-Ponty’s perception theory. On the other, and at the same time,
phenomenology is engaged in describing the activity of language and, in
particular, the speaking activity (prise de la parole) of a subject which is a “beingin-
the-world” (être-au-monde) and a “being-in-the-language” (être-au-langage):
this is the paradigmatic case of Merleau-ponty and of his own model of
linguistic gesture as emblem of expression. Furthermore, and more deeply,
phenomenology and semiotics are methods rather than disciplines (BORDRON
2011). By means of the epoché, phenomenology has tried to return the
articulation of the sensible and of the intelligible, and, on the other, the
connections between subjectivity and intersubjectivity. Similarly, semiotics has
proposed methods of analysis that are applicable to a wide range of domains:from narrative values to social identities, from textual traces to cultural
practices with particular reference to their conditions of emergence.
In this simultaneously archaeological and constructive orientation,
phenomenology and semiotics have brought new challenges concerning the
description of the phases of the meaning constitution
Vertebrate-mediated seed rain and artificial perches contribute to overcome seed dispersal limitation in a Mediterranean old field
Natural regeneration of vegetation is a frequent outcome of land abandonment, although the rate and diversity of such regeneration may be severely restricted by seed dispersal limitation, among other factors. In spite of this, studies aiming to quantify seed rain and test methods to enhance it, such as artificial perches, are still underrepresented in the Mediterranean. In our study, we quantified seed rain density and richness and tested the effects of artificial perches on such rain over a distance gradient on seven Mediterranean island old fields. In each of the seven sites, we positioned three sampling stations, each consisting of 1 seed trap under an artificial perch and 1 as a control on the ground, distributed at 30, 60, and 90 m from natural vegetation remnant. All traps received seeds, suggesting no overall dispersal limitation. Of the 11 seed species found, 10 were fleshy-fruited and dispersed by vertebrates. Seed traps under perches received significantly higher seed rain of fleshy-fruited species dispersed by birds, while ground traps received significantly more seeds of the species also dispersed by mammals, especially Rubus ulmifolius. The distance from the seed source was nonsignificant in all cases. Our study demonstrates the key role of vertebrate-mediated seed dispersal services to overcome dispersal limitation in old fields, as well as the effective contribution of even small artificial perches in contrasting such limitation. The lack of differences over the distance gradient reveal that the upper spatial limit of dispersal limitation was not achieved
Effect of moisture content on the processing and mechanical properties of a biodegradable polyester
This work is focused on the influence of moisture content on the processing and mechanical properties of a biodegradable polyester used for applications in injection molding. The pellets of the biodegradable polyester were exposed under different relative humidity conditions at a constant temperature before being compression molded. The compression-molded specimens were again placed under the above conditions before the mechanical testing. With all these samples, it is possible to determine the effect of moisture content on the processing and mechanical properties separately, as well as the combined effect of moisture content on the mechanical properties. The results obtained showed that the amount of absorbed water—both before processing and before mechanical testing— causes an increase in elongation at break and a slight reduction of the elastic modulus and tensile strength. These changes have been associated with possible hydrolytic degradation during the compression molding process and, in particular, with the plasticizing action of the moisture absorbed by the specimens
Flogosi post-trapianto di cornea
Il Trapianto di Cornea, o Cheratoplastica, che
prevede la sostituzione sub-totale della cornea
mediante un innesto circolare di tessuto omologo
(lembo), rappresenta la procedura d’elezione
per il trattamento di diverse patologie corneali
congenite o acquisite. Se ne discutono tutti i determinanti e le prospettive
Sambucus nigra L. (fam. Viburnaceae) in Sicily: Distribution, Ecology, Traditional Use and Therapeutic Properties
Sambucus nigra, the elderberry, has long been used for its medicinal properties in treating numerous diseases. Based on this traditional knowledge, its different pharmacological activities have been the focus of active research. All parts of the tree have long been used in traditional medicine, that is, the bark, the leaves, the flowers and the fruit. This study, carried out in Sicily (Italy), concerns the traditional uses of elder against human diseases. In order to trace the history of man's interaction with elder on the island, multidisciplinary research was carried out, aiming at (1) presenting a comprehensive overview of elderberry's applications and activities and (2) bridging traditional knowledge (uses and beliefs) with modern science, i.e., the most recent scientific findings in the biomedical and pharmacological fields. A rigorous literature review of scientific (and other local) reports on the elderberry tree and its application in food, health and household applications was undertaken. This article also provides a synthetic and updated picture of the ecology and distribution of S. nigra in Sicily. The elderberry is quite widespread in Sicily, yet its distribution is discontinuous. It prefers hedges, riparian woodlands, forest margins and clearings and is rather common along the watercourses flowing in the canyons of the Hyblaean Plateau, in the Madonie Mts. and in Enna province. Indeed, many old plants are often found near sacred places and rural houses, suggesting that in the past, it was extensively planted on purpose for its multiple uses. The complementary data obtained from multidisciplinary research confirm the usefulness of this approach in building a comprehensive and correct picture of the distribution of the most common woody species, for which the available knowledge is often fragmentary and imprecise
Life on islands. 1. Biodiversity in Sicily and surrounding islands. Studies dedicated to Bruno Massa
Influence of Branching on the Rheology, Filmability and Mechanical and Optical Properties of a Biodegradable and Compostable Co-Polyester
Over the last years, bio-based and biodegradable alternatives have gained considerable attention both of academic and of packaging industrial communities, driven by recent legislation and increasing awareness concerning environmental issues related to traditional plastic. However, it is often observed that packaging products made from bioplastics do not exhibit comparable performance to those produced using common non-biodegradable ones. The presence of long chain branching improves the processing behavior under elongational flow and, then, the filmability of low viscosity polymers such as polyesters. In this work it has been demonstrated that the presence of long chain branching in a bio-co-polyester, induced by the use of pentaerythritol in the synthesis a of poly(butylene adipate-co-butylene terephthalate), is able to dramatically change the rheological behavior of the linear chain polyester improving its filmability. The addition of branching lead to an increase of the elastic modulus and the tensile strength in branched polyester films if compared to the linear ones, while the elongation at break decreased. This is due to the answer of the branched polyester to the non-isothermal elongational flow that allows a better orientation of the macromolecules of the branched polyester. The film obtained with the branched polyester showed a decrease in clarity and a slight increase in haze if compared to linear one due to differences in the morphology of the two samples
Mechanical and thermal properties of insulating sustainable mortars with ampelodesmos mauritanicus and pennisetum setaceum plants as aggregates
The use of natural fibers in cement composites is a widening research field as their
application can enhance the mechanical and thermal behavior of cement mortars and limit their
carbon footprint. In this paper, two different wild grasses, i.e., Ampelodesmos mauritanicus, also
called diss, and Pennisetum setaceum, also known as crimson fountaingrass, are used as a source
of natural aggregates for cement mortars. The main purpose is to assess the possibility of using
the more invasive crimson fountaingrass in place of diss in cement-based vegetable concrete. The
two plant fibers have been characterized by means of scanning electron microscopy (SEM), helium
picnometry and thermogravimetric analysis. Moreover, the thermal conductivity of fiber panels has
been measured. Mortars samples have been prepared using untreated, boiled and Polyethylene glycol
4000 (PEG) treated fibers. The mechanical characterization has been performed by means of three
point bending and compression tests. Thermal conductivity and porosity have been measured to
characterize physical modification induced by fibers’ treatments. The results showed better thermal
and mechanical properties of diss fiber composites than fountaingrass one and that fiber treatments
lead to a reduction of the thermal insulation propertie
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