Search results for "ASTER"
showing 10 items of 2223 documents
The impact of climate change on Mediterranean intertidal communities: losses in coastal ecosystem integrity and services
2014
As has been shown for other ecosystems, the ecological and socio-economic impacts of climate change on Mediterranean intertidal habitats are highly variable in space and time. We conducted field and laboratory measurements of cellular, ecophysiological and behavioural responses of selected intertidal invertebrates (mussels, gastropods and sponges) and completed a literature review to determine what is known of socioeconomic consequences of these biological changes. Results suggest significant gaps in our knowledge that may impede a complete understanding of likely impacts (physical, biological, and socioeconomic) and that sufficient data for such an analysis is available only for mussels. A…
Fish-seastar facilitation leads to algal forest restoration on protected rocky reefs
2015
AbstractAlthough protected areas can lead to recovery of overharvested species, it is much less clear whether the return of certain predator species or a diversity of predator species can lead to re-establishment of important top-down forces that regulate whole ecosystems. Here we report that the algal recovery in a Mediterranean Marine Protected Area did not derive from the increase in the traditional strong predators, but rather from the establishment of a previously unknown interaction between the thermophilic fish Thalassoma pavo and the seastar Marthasterias glacialis. The interaction resulted in elevated predation rates on sea urchins responsible for algal overgrazing. Manipulative ex…
Feeding behaviour of Ophidiaster ophidianus (Lmk.) (Asteroidea) in Mediterranean rocky reefs
2017
The thermophilic Atlanto-Mediterranean purple starfish, Ophidiaster ophidianus, is a species protected under the EU’s Habitats Directive which is expanding its distribution in the northern Mediterranean areas as a consequence of global worming. The ecology of the species is largely unknown, specially for the diet. To cover this gap, the feeding habits of O. ophidianus have been studied in two different Mediterranean rocky reef areas: the southern Tyrrhenian Sea (Ustica Island, sampled in 2009) and the eastern Adriatic Sea (Molunat, sampled in 2014) by both field observations and ?13C and ?15N stable isotope analysis (SIA). SCUBA divers collected data by turning adult starfish downside-up an…
Distribution and diet of Marthasterias glacialis at Ustica Island MPA
2009
Distribution and diet of Marthasterias glacialis was studied at Ustica Island MPA. We conducted observations of the asteroid along the upper infralittoral zone using random parallel transects. M. glacialis was more abundant at study sites characterized by low densities of erect algae. Most frequent prey species was a bivalve and sea urchins
First record of Pachygrapsus transversus (Gibbes, 1850) (Brachyura, Grapsidae) in Italian waters
2005
[Pachygrapsus transversus (Gibbes, 1850) is reported for the first time from Italian waters. This crab was collected at Ustica Island and at several other localities on NW Sicily (southern Tyrrhenian Sea) on vermetid reefs, an intertidal habitat frequent in the sampling area. P. transversus, whose distributional range covers the warm and warm-temperate areas of the eastern and western Atlantic and the eastern Pacific, was already known from the eastern Mediterranean since the 1920s; prior to this paper it was recorded in the western Mediterranean only in 1980 and 1994 with very few specimens.There are no data to ascertain the origin of the Sicilian population, i.e., natural or ship-mediated…
Crushing predation of the spiny star Marthasterias glacialis upon the sea urchin Paracentrotus lividus
2009
Literature data report that only fish predators are able to crush sea urchin tests in Mediterranean rocky reefs. This experimental study showed that the spiny star Marthasterias glacialis is able to break Paracentrotus lividus tests and that the breaking event is more likely to occur for small-sized sea urchins than for big ones. Our results show that the role of M. glacialis in regulating P. lividus population density can be important in specific locations. They may have important implications, moreover, for the use of tethering techniques aimed at identifying predator types of sea urchins.
Functional antagonism between histone H3K4 demethylases in vivo
2011
Dynamic regulation of histone modifications is critical during development, and aberrant activity of chromatin-modifying enzymes has been associated with diseases such as cancer. Histone demethylases have been shown to play a key role in eukaryotic gene transcription; however, little is known about how their activities are coordinated in vivo to regulate specific biological processes. In Drosophila, two enzymes, dLsd1 (Drosophila ortholog of lysine-specific demethylase 1) and Lid (little imaginal discs), demethylate histone H3 at Lys 4 (H3K4), a residue whose methylation is associated with actively transcribed genes. Our studies show that compound mutation of Lid and dLsd1 results in increa…
Volatile components from flowers of Centaurea nicaeensis All., C. parlatoris Helder, C. solstitialis L., ssp. schouwii (DC.) Dostàl wild growing in S…
2008
The volatile constituents of the flowerheads of Centaurea nicaeensis All., C. parlatoris Helder and C. solstitialis L. ssp. schouwii (DC.) Dostal were extracted by hydrodistillation and analysed by GC and GC-MS. Altogether 113 components were identified. Fatty acids and hydrocarbons were the most abundant components in the oils. Caryophyllene and caryophyllene oxide were the main compounds of the sesquiterpene fraction. The study on the biological activity of the oils shows no significant activity.
Essential oil composition and antibacterial activity of Anthemis mixta L. and Anthemis tomentosa L. (Asteraceae)
2012
In the present study the chemical composition of the essential oils from aerial parts and roots of Anthemis mixta L. and A. tomentosa L. was evaluated by GC and GC-MS, and their antibacterial activity tested against ten bacterial species. Hexadecanoic acid (15.2%) was recognized as the main constituent of A. mixta, together with τ-cadinol (6.7%), while in both aerial parts and roots of A. tomentosa nonacosane (21.9% and 20.7%), heptacosane (8.1% and 6.0%), hexadecanoic acid (8.1% and 27.1%) and hexahydrofarnesylacetone (6.8% and 5.5%) prevailed. The oils from aerial parts of both species showed a good activity against Gram-positive bacteria. These results suggest that the plants could be po…
Perforazione della Caldera dei Campi Flegrei - Una proposta anfibia IODP-ICDP
2018
Active calderas are major volcanic features of the Earth’s crust associated with shallow magma reservoirs, high geothermal gradients, and geodynamic unrests often documented through historical time. As large caldera-forming eruptions are also among the most catastrophic events that may affect the Earth’s surface, calderas are ostensibly the sites of major interest for both the scientific community and governmental institutions worldwide. The Campi Flegrei is an active volcanic area located west of the city of Naples, largely on the continental shelf of the Eastern Tyrrhenian margin that has been characterized by dominantly explosive eruptions during the latest Quaternary. This is one among …