The composition of phosphate granules in the digestive glands of marine prosobranch gastropods: variation in relation to taxonomy

The composition of some 1150 phosphate granules in the digestive glands of over 40 species of marine prosobranch gastropods has been surveyed using a simple preparation technique and semiquantitative SEM x-ray microanalysis. Spectral peaks for Mg, K, Ca, Mn, Fe and Zn were compared to that of P. Four major types of phosphate granule can be recognised, each generally characteristic of a taxonomic grouping: high Mg in archaeogastropods and littorinids, multiple metal in higher mesogastropods, and, in neogastropods, Mg-Ca in muricoideans and high Zn in buccinoideans. At least one Conus species (C. ventricosus) has high-Mg granules. Some causes of variation in granule composition are discussed: speculatively, it is suggested a palaeoenvironmental influence seems possible.info:eu-repo/semantics/publishedVersio

Westward advancement of Pseudonereis anomala (Polychaeta: Nereididae) in the Mediterranean Basin (Piraeus, Saronikos Bay, Aegean Sea)

This paper reports the establishment of the Lessepsian Pseudonereis anomala (Gravier, 1901) in its new locality in the port of Piraeus (Saronikos Bay) and provides additional information on its population. The mean densities of P. anomala ranged from 0 indiv./m2 to 382.5 indiv./m2 among the calcareous alga Corallina elongata. A variety of sizes (length of the head and fi rst ten chaetigerous segments) was observed ranging fromPseudonereis anomala; Saronikos Gulf; Polychaete; Immigrant. 1.3mm to 8.1mm. There are indications that P. anomala may compete with other species of Nereididae. Accepted in December 200

Variability of environmental factors of an eastern Mediterranean Sea river influenced coastal system

Spercheios River discharge rates of nutrients, suspended particulate matter (SPM) and particulate organic carbon (POC) and seawater concentrations of these parameters as well as chlorophyll a(chl a) were measured in the Maliakos Gulf, Greece, on a monthly basis between 1992-1993. From all the nutrients measured, silicate showed the highest discharge rates followed by nitrate, phosphate and nitrite. The river introduced significant amounts of SPM (8.5 – 35.5 Kg d -1 ) with very low POC content (<3%). Most of the variables measured showed no gradient from the river to the outer gulf, which could be attributed to fast mixing of the incoming water. However, chl a had higher concentrations in the inner (0.3 – 4.9 Μg l -1 ) and lower in the outer gulf (0.05 – 2.5 Μg l -1 ). It is suggested that the nutrients introduced by the river are consumed faster in the inner gulf and that a number of temporal streams and non-point sources at the periphery of the gulf prevent the formation of a gradient

Multi-scale functional and taxonomic β-diversity of the macroinvertebrate communities in a Mediterranean coastal lagoon

Benthic macroinvertebrate communities form the basis of the intricate lagoonal food web. Understanding their functional and taxonomic response, from a β-diversity perspective, is essential to disclose underlying patterns with potential applicability in conservation and management actions. Within the central lagoon of Messolonghi we studied the main environmental components structuring the macroinvertebrate community. We analyzed the β-taxonomic and β-functional diversity across the main habitats and seasons, over a year time frame. Our results outline habitat type and vegetation biomass as the major factors structuring the communities. We found environmental variability to have a positive correlation with functional β-diversity, however no correlation was found with taxonomic β-diversity. Across the seasons an asynchronous response of the functional and taxonomic β-diversity was identified. The taxonomic composition displayed significant heterogeneity during the driest period and the functional during the rainy season. Across the habitats the unvegetated presented higher taxonomic homogeneity and functionally heterogeneity, contrary the vegetated habitats present higher taxonomic variability and functional homogeneity. Across the seasons and habitats a pattern of functional redundancy and taxonomic replacement was identified. Besides high functional turnover versus low taxonomic turnover was documented in an anthropogenic organically enriched habitat We conclude that habitats display independent functional and taxonomic seasonal patterns, thus different processes may contribute to their variability. The framework presented here highlights the importance of studying both β-diversity components framed in a multiscale approach to better understand ecological processes and variability patterns. These results are important to understand macroinvertebrate community assembly processes and are valuable for conservation purposes

Indirect reduced-order modelling:Using nonlinear manifolds to conserve kinetic energy

Nonlinear dynamic analysis of complex engineering structures modelled using commercial finite element (FE) software is computationally expensive. Indirect reduced-order modelling strategies alleviate this cost by constructing low-dimensional models using a static solution dataset from the FE model. The applicability of such methods is typically limited to structures in which (a) the main source of nonlinearity is the quasi-static coupling between transverse and in-plane modes (i.e. membrane stretching); and (b) the amount of in-plane displacement is limited. We show that the second requirement arises from the fact that, in existing methods, in-plane kinetic energy is assumed to be negligible. For structures such as thin plates and slender beams with fixed/pinned boundary conditions, this is often reasonable, but in structures with free boundary conditions (e.g. cantilever beams), this assumption is violated. Here, we exploit the concept of nonlinear manifolds to show how the in-plane kinetic energy can be accounted for in the reduced dynamics, without requiring any additional information from the FE model. This new insight enables indirect reduction methods to be applied to a far wider range of structures while maintaining accuracy to higher deflection amplitudes. The accuracy of the proposed method is validated using an FE model of a cantilever beam

Biological components of Greek lagoonal ecosystems: an overview

The paper summarises the available information on the main biological components – phytoplankton, zooplankton, phytobenthos, zoobenthos and fish – of Greek lagoonal ecosystems. Meiobenthos was also studied in one of the lagoons. All components show great variability both in space and time, which is attributed to the variability of environmental conditions. The most important variable influencing species distribution and diversity is the degree of communication with the sea and the nutrient load introduced through fresh water inputs. Certain new methods, which have been applied for evaluation of the ecological quality state of the lagoons, are also presented

Health related quality of life in patients with anogenital warts

<p>Abstract</p> <p>Introduction</p> <p>The health-related quality-of-life (HRQoL) instruments are an important tool for the evaluation of medical outcomes. Sexually transmitted diseases (STDs) influence the patients' life. We aimed to evaluate the HRQoL in patients with anogenital warts at the time of and 1 month after the diagnosis.</p> <p>Materials and methods</p> <p>We used the short-form (SF)-36 questionnaire to compare the HRQoL of 91 patients with anogenital warts to 53 control subjects with the same socioeconomic characteristics.</p> <p>Results</p> <p>There was no statistical difference in the overall HRQoL measurement between the anogenital wart patients and controls. However, there was an improvement in the scales of vitality (65.22 ± 15.70 vs. 69.04 ± 14.11, respectively; p < 0.05) and mental health (65.00 ± 20.09 vs. 69.43 ± 18.08, respectively; p < 0.05) in anogenital warts patients between the time of diagnosis and 1 month later. Furthermore, there was a significant deterioration in the scale of social functioning (73.47 ± 22.18 vs. 72.89 ± 19.28, respectively; p < 0.05). The small sample size is a limitation of our study.</p> <p>Conclusions</p> <p>HRQoL does not appear to be influenced in anogenital wart patients, as measured by the generic instrument SF-36. It is therefore important to develop specific instruments for the measurement of HRQoL in this group of patients.</p