Search results for "transe"
showing 10 items of 242 documents
Comparing cetacean abundance estimates derived from spatial models and design-based line transect methods
2007
Spatial modelling is increasingly being used as an alternative to conventional design- based line transect sampling to estimate cetacean abundance. This new method combines line transect sampling with spatial analysis to predict animal abundance based on the relationship of ani- mals observed to environmental factors. It presents several advantages including: (1) the ability to use data collected from 'platforms of opportunity', (2) the ability to estimate abundance for any defined subarea within the study area, and (3) the possibility for increased precision if covariates explain sufficient variability in the data. One study has been conducted to compare spatial modelling with conventional…
Diversity and Distribution of the Dinoflagellates Brachidinium, Asterodinium and Microceratium (Brachidiniales, Dinophyceae) in the open Mediterranea…
2011
Diversity and Distribution of the DinoflagellatesBrachidinium, AsterodiniumandMicroceratium(Brachidiniales, Dinophyceae) in the open Mediterranean SeaBrachidiniacean dinoflagellates have been investigated in the open waters of the Mediterranean Sea, along a transect from the south of France to the south of Cyprus (20 June-18 July 2008).BrachidiniumandKarenia papilionaceaoften co-occurred,B. capitatumpredominating in the surface waters. The highest abundance ofBrachidiniumwere found in the upper 25min the western Mediterranean with amaximum (24 cells L-1) at a depth of 5 m in the Balearic Sea.Asterodinium(up to 4 cells L-1) was recorded below of deep chlorophyll maxima. The genusMicroceratiu…
Preliminary patterns of distribution and abundance of loggerhead sea turtles, Caretta caretta , around Columbretes Islands Marine Reserve, Spanish Me…
2003
Aerial surveys were conducted to estimate the abundance and distribution of loggerhead turtles (Caretta caretta) in the Columbretes Islands Marine Reserve and surrounding waters (western Mediterranean). Four surveys were carried out during 2000 and 2001, following the line transect methodology. Loggerheads appeared to be present at high densities in the area throughout the whole year, although density varied between seasons, being more abundant during the spring. Mean density in the study area was 0.322 turtles/km2 (range 0.200–0.516) and the mean abundance was 1,324 turtles (range 825–2,124). The turtles were distributed homogeneously throughout the study area, we found no difference in lo…
Temporal Changes in Mollusk and Polychaete Communities in the Soft Bottom of Cullera Bay (Western Mediterranean)
2007
Abstract This study identifies the most abundant and significant species—from an ecological point of view—in the soft bottom of Cullera Bay (Spain) in order to study the seasonal (summer–winter) variations in the local communities of polychaete annelids and bivalve mollusks. This paper presents the results of the analysis of samples taken during two field campaigns (July 2002 and February 2003) of a series of five campaigns carried out in 2002 and 2003. For these field observations, twelve sampling stations were set up in the bay along three transects. At these stations, macrobenthos was collected using a Ponar grab. Only polychaete annelids and bivalve mollusks were selected from the sampl…
An empirical test of neighbourhood effect and safe-site effect in abandoned Mediterranean vineyards
2011
The importance of both neighbourhood effect and safe-site effect for the colonization of Mediterranean old fields by woody plants was investigated. Using a transect approach, we recorded colonization of 21 species of woody plants on abandoned, terraced vineyards on Pantelleria Island (Sicily) in dependence from neighbouring terraces in older succession stages (Maquis) and available safe sites for seedling establishment (former crop plant, terrace wall). With a paired design of four treatments, including presence/absence of adjacent older successional stages, and North-/South-facing slopes, a neighbourhood effect could be shown for both expositions if the transect started from an adjacent fi…
An insight into the status of the striped dolphins, Stenella coeruleoalba, of the southern Tyrrenian Sea
2007
Drift-nets are known to result in high incidental catches of some cetacean species. Despite a UN moratorium on their use in the high seas and a ban in the Mediterranean by all European Union countries, including Italy (EC Reg. 1239/98), some fisheries continue to operate illegally. In 2002 and 2003 three line-transect surveys were conducted in the southern Tyrrhenian Sea around the Aeolian archipelago. These transects were designed to assess the presence, distribution and population size of cetacean species likely to be affected by accidental captures in this area. Data were only sufficient to estimate abundance for the striped dolphin. The best estimate (and first such estimate for this ar…
Macrofungi in Mediterranean maquis along seashore and altitudinal transects
2014
In semi-arid Mediterranean environments, fungal activity is fundamental for buffering biotic and abiotic stress to the plant and for sustaining a vegetation cover. Despite the important role that fungi play in habitats stability, mycological data from Mediterranean ecosystems are scarce and fragmentary. We investigated fungal diversity in several areas characterized by Mediterranean maquis, from continental Italy, Sicily, and Greece in order to contribute to the analysis of distribution, ecology, and diversity of macrofungi in evergreen sclerophyllous shrublands at different elevation and distance from the seashore across the Mediterranean Basin. Several fungal taxa that are remarkable due …
The role of topography and erosion in the development and architecture of shallow-water coral bioherms (Tortonian-Messinian, Cabo de Gata, SE Spain).
2009
23 pages; International audience; During the Miocene, Mediterranean shallow-water carbonates were rich in scleractinian corals, which thrive in various depositional settings. A Tortonian–Messinian bioherm belt developing in a heterozoan-dominated ramp was investigated along a 1.2 km continuous transect located in the Cabo de Gata region. The interval studied displays four depositional environments from mid-to-inner ramp, dominated by swell waves and storm energy, deposited as a single, large-scale depositional sequence during a 3rd to 4th order transgressive–regressive cycle. The bioherms grew in three phases, and were essentially composed of inplace primary frameworks. Three coral genera w…
Reactive blending of a functionalized polyethylene with a semiflexible liquid crystalline copolyester
1996
Reactive blends (50/50 w/w) of a low molar mass polyethylene containing free carboxylic groups (PEox) and a semiflexible liquid crystalline polyester (SBH 1 : 1 : 2, by Eniricerche) have been prepared at 240 degrees C in a Brabender mixer, in the presence of Ti(OBu)(4) catalyst, for different mixing times (15, 60, and 120 min). In order to prove the formation of a PE-g-SBH copolymer, the blends have been fractionated by successive extractions with boiling toluene and xylene. The soluble fractions and the residues have been analyzed by Fourier transform infrared (FTIR) spectroscopy, thermogravimetry (TG and DTG), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM)…
L-selectin regulates human neutrophil transendothelial migration
2021
ABSTRACT The migration of circulating neutrophils towards damaged or infected tissue is absolutely critical to the inflammatory response. L-selectin is a cell adhesion molecule abundantly expressed on circulating neutrophils. For over two decades, neutrophil L-selectin has been assigned the exclusive role of supporting tethering and rolling – the initial stages of the multi-step adhesion cascade. Here, we provide direct evidence for L-selectin contributing to neutrophil transendothelial migration (TEM). We show that L-selectin co-clusters with PECAM-1 – a well-characterised cell adhesion molecule involved in regulating neutrophil TEM. This co-clustering behaviour occurs specifically during …