The lower pleistocene succession

ItVengono esposti aspetti stratigrafici e paleontologici di una successione calcarenitico-sabbioso-argillosa spessa 4,1 m, affiorante in Contrada Torsano (Nardò, provincia di Lecce), caratterizzata da livelli fossiliferi a molluschi, scafopodi, brachiopodi e coralli tra cui prevalgono Venus verrucosa, V. casina, Acanthocardia tuberculata, Aequipecten opercularis, Glossus humanus, Thracia convexa, Neopycnodonte cochlear, Pecten jacobaeus, Terebratula scillae, Dentalium rectum e Flabellum sp.; sono altresì presenti gli "ospiti nordici" Pseudamussium septemradiatum, Paphia rhomboides e soprattuto Arctica islandica. Quest’ultima è rappresentata da individui di grande taglia analogamente a popolamenti nordatlantici attuali (KENNISH and LUTZ, 1995; THORARINSDOTTIR and EINARSSON, 1996). I livelli fossiliferi (shell concentrations sensu KIDWELL, 1991; FÜRSICH, 1995) hanno caratteri di deposito primario e possono rappresentare il prodotto di strategie di adattamento o di favorevoli condizioni ecologiche.La maggior parte delle specie riconosciute nella successione di Torsano è attualmente presente nel Mediterraneo (PARENZAN, 1970; 1974; 1976; DEMIR, 2003; REPETTO et al., 2005). Alcune sono indicative di particolari condizioni ambientali come Lucinoma boreale, tipica di fondali mobili (MALATESTA, 1974) e Thracia convexa, esclusiva delle Biocenosi dei fanghi Terrigeni Costieri (PICARD, 1965; PÉRÈS, 1967).In generale, dalla base al tetto della successione analizzata, è definibile un cambiamento delle condizioni paleoambientali dalla zona infralitorale, soggetta a fenomeni di abrasione meccanica delle onde, a quella circalitorale per progressivi aumenti delle profondità del fondale e della torbidità delle acque.EnThis paper deals with the stratigraphic and paleontological features of a 4.1 m thick succession outcropping at Contrada Torsano (Nardò, Lecce province). Shell concentration due to biological processes, particularly rich in the northern guests Arctica islandica, Pseudamussium septemradiatum and Paphia rhomboides are described. Based on Terebratula scillae and Dentalium rectum presences, the succession must be attributed to the lower Pleistocene. The high specimen density could be due to opportunistic life strategies and optimal ecological conditions. Environmental change can be recognized from the infralittoral zone, exposed to the marine abrasion, to circalittoral zone as the result of the increasing of both depth and sea water turbidity

Serapias X Marchiorii Turco & Medagli (Serapias Bergonii E. G. Camus X Serapias Politisi Renz) Ibrido naturale nuovo del Salento

EnNatural hybridization in the plant kingdom, that particularly occurs in disturbed habitats where is generally considered as a threat for rare and endangered species, is a potent evolutionary force. In fact in Mediterranean orchids, mainly pertaining to the Anacamptys, Ophrys and Serapias genres, the hybridization is a common phenomenon, as a natural consequence of their pollination system, that often it has carried to the defined phenomenon “sympatric speciation”. Here we describe the result of this process as a new Orchidaceae’s hybryd species, belong to Serapias genus, named Serapias x marchiorii Turco & Medagli, through analysis of the morphological aspects. The parental of the new hybrid species are: Serapias bergonii E.G. Camus and Serapias politisi Renz. Serapias bergonii = S. vomeracea (N.L. Burm.) Briq. subsp. laxiflora (Soò) Gölz & Reinhard was originally described as an hybrid entity, result of a discovery made in Corfù at the “Saline of Potamos”. It is a species that is distributed in eastern areas, present in Italy only in the southern Apulia and southern Sicily. Serapias politisi, instead, was originally described as an hybrid between Serapias bergonii and Serapias parviflora at the island of Corfù, then was defined as a species and reported for the mainland Greece, the Aegean’s islands, the western Anatolia and in Apulia, the only Italian region of presence, where it is widespread mostly in Salento. Thus, the ranges of these two entities have little overlap that make rare and localized the interspecific hybrids. This is, probably, the reason that makes the hybrid in question not widely distributed. S. x marchiorii was found in a small area known as “Palude di Cassano” in the town of Melendugno (Le) along the adriatic coast, May 13, 2009. The area of small dimensions, is occupied mostly by a depression in karst nature which was partially drained in the middle of ‘900 with the creation of a drainage channel; the area surrounding the marsh is mainly occupied by grasslands and maquis. The station was found with few plants and was situated at an altitude between 12 and 15m above sea level, on a calcareous substrates known as “Calcareniti del Salento”

Osservazioni e considerazioni su alcune specie costiere rupicole del Salento

ItGli autori riportano osservazioni e considerazioni riguardanti alcune specie delle coste rocciose del Salento meridionale.EnThe authors report observations and considerations concerning some species situated on the rocky coast of southern Salento

Evidence from multivariate morphometric study of the quercus pubescens complex in southeast Italy

The name Quercus pubescens s.l. encompasses a complex of deciduous oak taxa with mainly southeastEuropean distribution and a large ecological niche. As the easternmost region of Italy, Apulia is rather isolated from a geographical and physiographical viewpoint and counts the highest number of oak species (10). In the taxonomic and phytosociological literature, the occurrence of several species belonging to the Quercus pubescens collective group is reported for this region. In order to verify if different sets of morphological characters are associated with different taxa, 24 populations of Quercus pubescens s.l. located in different ecological-geographical areas of Apulia were sampled. A total of 367 trees, 4254 leaves and 1120 fruits were collected and morphologically analysed. Overall, 25 morphological characters of oak leaves and fruits were statistically treated using both univariate and multivariate analysis. Nested ANOVA showed that leaves collected from a single tree exhibited a degree of morphological variability higher than that observed when comparing leaves coming from different trees of the same population and from different trees of different populations as well. Almost all the morphological characters analysed exhibited a continuous trend of variation so that none of them can be used as a character to discriminate between populations. Only leaf and fruit “size” and fruit petiole length emerged as slightly discriminating characters. Our results suggest that it is unlikely that more than one species belonging to the Quercus pubescens complex occurs in the Apulia region. Comparison between the Apulian populations and a genetically pure Q. pubescens population coming from a different area (the Molise region) strengthened the assumption as to the existence of a single species that can provisionally be classified under the name of Q. pubescens s.

Comparative chromosome studies in species of subtribe Orchidinae (Orchidaceae)

In our study, FISH mapping using 18S-5.8S-25S rDNA and 5S rDNA sequences was performed for the first time on Ophrys tenthredinifera Willdenow, 1805, Serapias vomeracea (Burman f., 1770) Briquet, 1910 and Himantoglossum hircinum (Linnaeus, 1753) Sprengel, 1826. A detailed study was also performed on O. tenthredinifera using Giemsa-staining, silver-staining, CMA fluorescence banding and fluorescence in situ hybridisation (FISH) with rDNA probes. We analysed two subspecies, i.e. O. tenthredinifera subsp. neglecta (Parlatore, 1860) E.G. Camus, 1908 and O. tenthredinifera subsp. grandiflora (Tenore, 1819) Kreutz, 2004 by the traditional Feulgen method and constructed the karyotype. The cytotaxonomic implications for both taxa are also discussed. In Himantoglossum hircinum, FISH and silver staining highlighted differences in the number of two rDNA families (35S and 5S) with respect to Barlia robertiana (Loiseleur-Deslongchamps, 1807) Greuter, 1967. In addition, fluorescence in situ hybridisation was also applied to diploid (2n = 2x = 36) and triploid (2n = 3x = 54) Anacamptis morio (Linnaeus, 1753) R.M. Bateman, Pridgeon et M.W. Chase, 1997. As far as we are aware, this is the first case of autotriploidy observed in A. morio

Presenza di Ostrya carpinifolia Scop. e di Quercus trojana Webb lungo la piana costiera brindisina

ItGli autori riferiscono del ritrovamento di Ostrya carpinifolia Scop. e di Quercus trojana Webb lungo la costa della provincia di Brindisi.EnAbout the presence of Ostrya carpinifolia Scop. and Quercus trojana Webb along the coastal plain of the province of Brindisi-The authors report about the finding of Ostrya carpinifolia Scop. and Quercus trojana Webb along the coast of the province of Brindisi

Centaurea pumilio l. (asteraceae), una nuova specie per la flora italiana

EnThe authors point out the first finding in Southern Apulia (Torre S. Giovanni, Ugento) of Centaurea pumilio L., a species up to now known for the eastern districts of the Mediterranean region. Details on floral morfology and population viability are given.ItGli autori descrivono il primo ritrovamento in Italia, nella Puglia meridionale (Torre S. Giovanni, Ugento) di Centaurea pumilio L., specie tipica della regione orientale mediterranea. Vengono descritti anche i campioni esaminati e la consistenza della popolazione rilevata

Learners' experience of presence in virtual worlds

This thesis explores participants' experiences of presence in virtual worlds as a specific case of mediated environments, and the factors that support that experience of presence, with the aim of developing practice when using these technologies in learning and teaching. The thesis begins with a framework that was created to bring together concepts from a range of disciplines that describe presence and factors that contribute to presence. Organising categories within the framework were drawn from a blend of Activity Theory and Communities of Practice. Five case studies in Second Life (preceded by a pilot study employing webconferencing) were conducted in order to investigate learners' experiences in these environments. Qualitative and quantitative data were gathered from these cases. The data from the separate cases were analysed using a cross-case synthesis and the role of presence, and the factors that support it, were identified. An additional strand of investigation established a typology of different forms of resistance by students to learning in virtual worlds. The findings of the study were that an experience of presence is strongly linked to students' satisfaction with the learning activity. This experience of presence was more linked to students' preparedness or ability to engage with the environment than with technological limitations. Some students' resistance to learning in virtual worlds were informed by values they held about technology, but others appeared to display an inability to experience embodiment through their avatar. The experience of presence appeared to develop over time. This can be interpreted as stages in students' development of a virtual body image, body schema and virtual identity. Different learning activities are more appropriate to different stages in this development. The thesis concludes with a suggested model for supporting students' development of presence. The implications of these findings for educators and for further research are discussed.EThOS - Electronic Theses Online ServiceGBUnited Kingdo