Search results for " Invasion"

A review on the animal xenodiversity in Sicilian inland waters (Italy)

2015

This paper reviews the available knowledge about faunal xenodiversity in Sicilian inland waters (Italy). The aim is to provide an updated checklist and bibliography of those non-indigenous species (NIS) which occur in the island, and to identify possible threats to its native biological diversity. Data were collected through an extensive literature search which encompassed also local journals, books, congress abstracts, and other grey literature. All the collected data were critically revised and, when possible, verified by consulting available collections or through dedicated sampling surveys. Only those data contained in reports indicating precise occurrence localities, which were confirm…

Baseline assessment of heavy metals content and trophic position of the invasive blue swimming crab Portunus segnis (Forskål, 1775) in the Gulf of Ga…

2018

This study provides a baseline assessment of cadmium, copper, iron, manganese, lead, and zinc concentrations in muscles, gills, and exoskeleton of the Lessepsian blue swimming crab Portunus segnis captured in the Gulf of Gabès (Southern Mediterranean Sea, Tunisia) in November 2015. Furthermore, the species’ trophic position is estimated using CN stable isotope analysis. The exoskeleton showed the lowest metal contents; in soft tissues, the essential Cu, Fe, and Zn and the non-essential Cd, Mn, and Pb showed the highest and lowest concentrations, respectively. The crab was characterized by a trophic position of 3.32, confirming its carnivorous trophic habits. Compared with literature data on…

Effect of salinity and temperature on feeding physiology and scope for growth of an invasive species (Brachidontes pharaonis - MOLLUSCA: BIVALVIA) wi…

2008

Abstract The Indo-Pacific mytilid Brachidontes pharaonis (Bivalvia, Fischer 1870) offers an excellent model for the study of “Lessepsian migration” and the successive colonization at new Mediterranean locations. This species in out competing indigenous bivalves is particularly well adapted to Mediterranean conditions and this is likely due to biological characteristics and physio-ecological plasticity. In the present paper, we report on clearance rate (CR), respiration rate (RR) and Scope for Growth (SFG) of B. pharaonis collected from a Western Sicilian pond (Southern Tyrrhenian, MED). Physiological variables were determined in response to a range of temperatures from 11 ° to 20 °C and a b…

Role of interspecific interactions in biological invasions: new evidence from the Mediterranean Sea

Despite the field of invasion ecology has rapidly grown, the mechanisms behind the invasion success of alien species and the biotic resistance to invasions still need a thorough understanding. Comprehending the response of resident assemblages to biological invasions and the possible impacts produced by alien species introduction is, therefore, crucial to expand the current knowledge of the invasion process in the recipient systems. In this thesis different aspects of biological invasion process have been critically examined emphasizing the importance and complexity of the interactions between alien species and native biota, in the Mediterranean marine coastal ecosystems. Here, five differe…

La Sicilia negli Orsi di Dino Buzzati e Lorenzo Mattotti

2022

Nella fiaba illustrata di Dino Buzzati La famosa invasione degli orsi in Sicilia (1945) e nella sua trasposizione filmica ad opera di Lorenzo Mattotti (2019) l’ambientazione siciliana è determinante. In entrambi i casi la Sicilia è un’isola con un grande vulcano – trasfigurata in un ambiente fantastico o riscritta secondo alcuni stereotipi – che i due autori utilizzano con accezioni diverse nella costituzione dell’ecosistema delle loro narrazioni. Soltanto attraverso una comparazione tra le due opere sarà possibile distinguere la rappresentazione delle due Sicilie che vengono raccontate con un intervallo di circa settanta anni. Se non si considera la storia degli Orsi soltanto una fiaba per…

Le specie alloctone invasive in Sicilia: caratterizzazione del fenomeno, strategie di colonizzazione e possibili strategie di contrasto

2014

NG2 regulates directional migration of oligodendrocyte precursor cells via Rho GTPases and polarity complex proteins.

2013

The transmembrane proteoglycan NG2 is expressed by oligodendrocyte precursor cells (OPC), which migrate to axons during developmental myelination and remyelinate in the adult after migration to injured sites. Highly invasive glial tumors also express NG2. Despite the fact that NG2 has been implicated in control of OPC migration, its mode of action remains unknown. Here, we show in vitro and in vivo that NG2 controls migration of OPC through the regulation of cell polarity. In stab wounds in adult mice we show that NG2 controls orientation of OPC toward the wound. NG2 stimulates RhoA activity at the cell periphery via the MUPP1/Syx1 signaling pathway, which favors the bipolar shape of migrat…

Modeling multiple taxis: Tumor invasion with phenotypic heterogeneity, haptotaxis, and unilateral interspecies repellence

2021

We provide a short review of existing models with multiple taxis performed by (at least) one species and consider a new mathematical model for tumor invasion featuring two mutually exclusive cell phenotypes (migrating and proliferating). The migrating cells perform nonlinear diffusion and two types of taxis in response to non-diffusing cues: away from proliferating cells and up the gradient of surrounding tissue. Transitions between the two cell subpopulations are influenced by subcellular (receptor binding) dynamics, thus conferring the setting a multiscale character. We prove global existence of weak solutions to a simplified model version and perform numerical simulations for the full se…

Inventory of the non‐native flora of Italy

2009

In this paper we present a comprehensive inventory of the non‐native vascular flora of Italy, which was produced within the project “A survey of the Italian non‐native flora”, funded by the Italian Ministry for the Environment. Previously published floristic accounts were the main source of information. Historical records were critically revised and integrated with recent literature, data from herbaria and some unpublished information, so as to obtain a complete, up‐to‐date catalogue of the non‐native vascular plant species that occur spontaneously in Italy. The inventory lists 1023 non‐native species and subspecies, which account for 13.4% of all the Italian flora. The Italian non‐native f…

Microsporidian disease of the invasive amphipod Dikerogammarus villosus and the potential for its transfer to local invertebrate fauna.

2012

12 pages; International audience; Invasive species may introduce novel pathogens to a colonised area. Most of the time emerging pathogens are detected a posteriori, but recognition of a priori emergence of an invasive disease by host shift may be useful for predictive purposes. Here, we studied if the microsporidian parasite Cucumispora dikerogammari infecting the invasive Ponto-Caspian amphipod Dikerogammarus villosus, has the potential to become an emergent disease in invaded rivers in Western and Central Europe. We first showed that this parasite decreases the survival of D. villosus in the later stages of infection development. However, the host reproduces earlier in response to the inf…