Search results for "SAPR"
showing 10 items of 142 documents
Calcareous Nannofossil and Planktonic Foraminifera Biostratigraphy of selected Piacenzian-Gelasian Laminites from Southern Italy
2011
Here we present the biostratigraphic and chronostratigraphic framework of a number of selected diatomaceous laminated intervals from the Crotone Basin (Calabria, Southern Italy). These layers, which we consider correlative to the Eastern Mediterranean Sapropel Layers, range in age from the early Piacenzian to the Gelasian, and show surprising thicknesses, suggesting that they were probably laid down in a landlocked, overfed basin. Specifically, a thick laminite from the surroundings of Cropani (Catanzaro) can be ascribed to nannofossil biozone MNN 16a and planktonic foraminifera biozone MPL 4b (lower Piacenzian) according to the Mediterranean calcareous plankton biostratigraphic zonations. …
African monsoon variability during the previous interglacial maximum.
2002
Little is known about centennial- to millennial-scale climate variability during interglacial times, other than the Holocene. We here present high-resolution evidence from anoxic (unbioturbated) sediments in the eastern Mediterranean Sea that demonstrates a sustained V800-yr climate disturbance in the monsoonal latitudes during the Eemian interglacial maximum (V125 ka BP). Results imply that before and after this event, the Intertropical Convergence Zone (ITCZ) penetrated sufficiently beyond the central Saharan watershed (V21n) during the summer monsoon to fuel flooding into the Mediterranean along the wider North African margin, through fossil river/wadi systems that to date have been cons…
Pliocene sapropels in the northern Adriatic area: chronology and paleoenvironmental significance
1997
Abstract A detailed stratigraphic and paleoenvironmental study was carried out ona marine section from the Marecchia Valley in the Northern Apennines. The section consists predominantly of deep-water hemipelagic clays intercalated with 15 thick, laminated sapropels (M1–M15). Based on biostratigraphic (calcareous nannoplankton and planktonic foraminifera) and magnetostratigraphic results, the Marecchia Valley section is interpreted as being middle to late Pliocene in age, extending from the upper part of the Gauss Chron to the lower part of the Matuyama Chron. The high resolution stratigraphy allows us to correlate, for the first time, these northern Italian sapropels with sapropels previous…
Surface and deep water conditions in the Sicily channel (central Mediterranean) at the time of sapropel S5 deposition
2011
New centennial-scale data of benthic foraminifera assemblages and of stable isotopes of foraminifera shells from the Sicily Channel, representative of surface and bottom waters, over the interval between about 140 and 110 kyr BP, are presented. During this period anoxia developed on the eastern Mediterranean basin and sapropel S5 deposited. Although anoxic sediments have not been deposited in the Sicily Channel, this area is strategic to study the character of intermediate waters, whose chemical-physical properties strongly precondition the eastern Mediterranean deep water formation. So far, no data from these water masses have been obtained, apart from the isotopic composition of shells of…
A high-resolution record of the last deglaciation in the Sicily Channel based on foraminifera and calcareous nannofossil quantitative distribution
2003
Abstract Relative abundance fluctuations in planktic foraminiferal and calcareous nannofossil assemblages are reported on the basis of a high-resolution study of ODP Leg 160 Hole 963D, drilled in the Sicily Strait, near Capo Rossello (southern Sicily). With its 8 m of undisturbed sediments, the core covers the interval from 1.5 to 23 kyr, allowing a 50–100-yr sampling resolution. All the short warm and cold events and sub-events recorded in this time interval in the GRIP Greenland ice core and at several Mediterranean sites were recognized. On this basis, a total number of nine ecozones based on planktic foraminifera and seven ecozones based on calcareous nannofossils were identified. A sho…
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 …
Wood-inhabiting fungal communities : Opportunities for integration of empirical and theoretical community ecology
2022
Publisher Copyright: © 2021 The Author The interest in studying wood-inhabiting fungal communities has grown in recent years. This interest has mainly been motivated by the important roles of wood-inhabiting fungi in ecosystem functioning (e.g. nutrient cycling) and conservation biology (e.g. their sensitivity to forest management). In this paper, I argue that another important, but yet largely unexplored motivation for studying wood-inhabiting fungal communities, is their potential to advance fundamental community ecology. One major advantage of wood-inhabiting fungi as model systems is that they are organized as spatially well-defined metacommunities, thus conforming to the assumptions of…
The hemagglutinin of Staphylococcus saprophyticus binds to a protein receptor on sheep erythrocytes.
1997
Staphylococcus saprophyticus, an important cause of urinary tract infections, produces two major surface proteins, the S. saprophyticus surface-associated protein (Ssp) and the hemagglutinin, which mediates fibronectin binding and also functions as the major adhesion of the organism. The hemagglutinating and fibronectin binding functions probably reside on different parts of the molecule. To identify a receptor on eukaryotic cells, binding and inhibition studies with acidic and neutral glycosphingolipids, carbohydrates, and proteins of sheep erythrocyte membranes were conducted. S. saprophyticus did not bind to any glycosphingolipid and no inhibition was observed when hemagglutination assay…
Expression of Staphylococcus saprophyticus surface properties is modulated by composition of the atmosphere.
1995
Expression of two major surface proteins of Staphylococcus saprophyticus, the haemagglutinin and the Staphylococcus saprophyticus surface-associated protein (Ssp), requires carefully defined culture conditions. The Ssp is produced when bacteria are grown on agar, whereas expression of the haemagglutinin requires growth in broth. We sought to identify the environmental signals that are responsible for this modulation. Varying the pH, the osmolarity of the growth medium or the temperature did not influence expression of the proteins. In contrast, growth in an anaerobic atmosphere increased haemagglutination titres and fibronectin binding (both mediated by the haemagglutinin) but suppressed pr…