Multi-scale spatio-temporal patchiness of macrozoobenthos in the Sacca di Goro lagoon (Po River Delta, Italy)

1 - In this study, the macrobenthos from different habitats in the Sacca di Goro lagoon (Po River Delta, Italy) is analysed by following a multi-scale spatio-temporal approach, with the aim of evaluating the spatial patchiness and stability of macroinvertebrate assemblages in the lagoon. The scale similarity is examined by using a taxonomic metrics based on the Kullback-Leibler divergence and a related index of similarity.2 - Data were collected monthly during one year in four dominant habitat types, which were classified on the basis of main physiognomic traits (type of vegetation and anthropogenic impact). Three of the selected habitats were natural (macroalgal beds, bare sediment and Phragmitetum) and one anthropogenically modified (the licensed area for Manila clam farming). Each habitat was sampled in a variable number of stations representative of specific microhabitats, with three replicates each.3 - Of the 47 taxa identified, only few species were found exclusively in one habitat type, with low densities. No taxon was dominant in all the considered habitats.4 - The results show that, in spite of the large overlapping of species, the spatio-temporal dissimilarity within each habitat type was higher than expected on the basis of the common physiognomic traits. This suggests that local factors (mainly hydrodynamism, quality and quantity of vegetal matter) play a significant role in determining the structure of the macroinvertebrate assemblages.5 - The dissimilarity between habitats was significant and maintained all over the seasonal progression, indicating that the macroinvertebrate assemblages were steadily different. Each habitat allowed some specific taxa to maintain a significant population size, which is a prerequisite for preserving biodiversity.6 - The variety of vegetation types and hydrodynamic conditions in the lagoon emerges as crucial for sustaining biodiversity and capacity to recover from disturbances

Ontogenetic shift in the trophic role of the invasive killer shrimp Dikerogammarus villosus: a stable isotope study

none5noThe introduction of the amphipod Dikerogammarus villosus in European fresh waters is to date recognized as a threat to the integrity of invaded communities. Predation by D. villosus on native benthic invertebrates is assumed as the key determinant of its ecological impact, yet available information describe the species as a primary consumer as well as a carnivore depending on local conditions. Here, we assessed the trophic position (TP) of D. villosus in Lake Trasimeno, a recently invaded lentic system in central Italy, using the CN isotopic signatures of individuals captured in winter spanning two orders of magnitude in body size. TP estimations were compared with those characterizing the native amphipod Echinogammarus veneris and other representative invertebrate predators. On average, D. villosus showed a trophic position higher than E. veneris, and comparable with that of odonate nymphs. An in-depth analysis revealed that large-sized individuals had a trophic position of 3.07, higher than odonates and close to that of the hirudinean predator Erpobdella octoculata, while small-sized specimens had a trophic position of 2.57, similar to that of E. veneris (2.41). These findings indicate that size-related ontogenetic shifts in dietary habits may per se vary the nature of the interaction between Dikerogammarus villosus and native invertebrates from competition to predation. Information collated from published isotopic studies corroborated the generality of our results. We conclude that intra-specific trophic flexibility may potentially amplify and make more multifaceted the impact of the species on other invertebrate species in invaded food webs.openMancini F.; De Giorgi R.; Ludovisi A.; Vizzini S.; Mancinelli G.Mancini, F.; De Giorgi, R.; Ludovisi, A.; Vizzini, S.; Mancinelli, G

Meteorological and water quality changes in Lake Trasimeno (Umbria, Italy) during the last fifty years

This paper illustrates the results of an analysis performed on historical data of the main meteorological and water quality variables collected during the last fifty years in the basin of Lake Trasimeno, a shallow lake subjected to important water level fluctuations. The results reveal a significant increase of the annual mean of minimum and maximum air temperature, water temperature and solar radiation, and a significant reduction of precipitation and cloud cover, which have mostly occurred during the last twenty years. The decadal rate of warming observed in the last twenty years for air temperature (0.33 °C decade-1) is consistent with the estimate reported by the IPCC for the land-surface temperature in the Northern Hemisphere, whereas the surface water temperature in Lake Trasimeno shows a more marked increase (0.65 °C decade-1), comparable to that observed in other lakes of Mediterranean areas. On a monthly scale, the most significant variations are observed in late-spring and early summer months for temperature and solar irradiation, and in winter and spring months for rainfall, which result in an appreciable modification of the seasonal progression. The alterations of the thermal and hydrological balance of the lake have caused a progressive lowering of the water level and the emergence of evaporative conditions. As a consequence of the drought, a progressive accumulation of dissolved salts (3.5 106 kg y-1) is observed, which is partially explained by meteoric loading. The analysis also shows that an increase in the total alkalinity has occurred during the main drought phases of the last forty years, which has been shown to be consistent with what expected on the basis of the changes in the ionic composition of the waters. With decreasing water levels, a strong reduction in water transparency has also been observed, which does not appear to be connected with a change in the trophic state of the lake, but rather with the increase of suspended solids from bottom sediments, in agreement with the predictions based on resuspension models in shallow waters. On putting the results into the future scenario of climate change, an accelerating drought and progressive worsening of the water quality can be predicted for Lake Trasimeno in the near future

Geochemical Proxies and Mineralogical Fingerprints of Sedimentary Processes in a Closed Shallow Lake Basin Since 1850

AbstractLake systems are essential for the environment, the biosphere, and humans but are highly impacted by anthropogenic activities accentuated by climate change. Understanding how lake ecosystems change due to human impacts and natural forces is crucial to managing their current state and possible future restoration. The high sensitivity of shallow closed lakes to natural and anthropogenic forcing makes these lacustrine ecosystems highly prone to variations in precipitation and sedimentation processes. These variation processes, occurring in the water column, produce geochemical markers or proxies recorded in lake sedimentary archives. This study investigated specific proxies on high-resolution sedimentary archives (2–3 years resolution) of the Trasimeno lake (Central Italy). The Trasimeno lake underwent three different hydrological phases during the twentieth century due to several fluctuations induced mainly by human activities and climate change. The Trasimeno lake, a large and shallow basin located in the Mediterranean area, is a good case study to assess the effects of intense anthropogenic activity related to agriculture, tourism, industry, and climate changes during the Anthropocene. The aim is to identify the main characteristics of the main sedimentary events in the lake during the last 150 years, determining the concentrations of major and trace elements, the amount of organic matter, and the mineralogical composition of the sediments. This type of work demonstrates that studying sediment archives at high resolution is a viable method for reconstructing the lake's history through the evolution/trends of the geochemical proxies stored in the sediment records. This effort makes it possible to assess past anthropogenic impact and, under the objectives of the European Green Deal (zero-pollution ambition for a toxic-free environment), to monitor, prevent, and remedy pollution related to soil and water compartments. Graphical abstrac

La ética y el derecho en la producción y el consumo del entretenimiento

Contiene las ponencias y comunicaciones del congreso

Ultrasound diagnosis of serous surface papillary borderline ovarian tumor: A case series with a review of the literature

Serous surface papillary borderline ovarian tumors (SSPBOTs) are a rare morphologic variant of serous ovarian tumors that are typically confined to the ovarian surface, while the ovaries themselves tend to appear normal in size and shape. In this report, we describe the findings from five premenopausal women diagnosed with SSPBOTs, in whom ultrasound showed grossly normal ovaries that were partially or wholly covered with irregular solid tumors. In all five cases, histologic examination showed evidence of borderline serous tumors. These findings demonstrate that SSPBOTs can be diagnosed on a preoperative sonographic examination, which could facilitate conservative, fertility-sparing surgery in young women affected by this condition. © 2015 Wiley Periodicals, Inc. J Clin Ultrasound, 2015

On Rationality

Rationality is an enduring topic of interest across the disciplines and has become even more so, given the current crises that are unfolding in our society. The four books reviewed here, which are written by academics working in economics, political science, political theory and philosophy, provide an interdisciplinary engagement with the idea of rationality and the way it has shaped the institutional frameworks and global political economy of our time. Rational choice theory has certainly proved to be a useful analytic tool in certain contexts, and instrumental reason has been a key tenet of human progress in several periods of history, including the industrial revolution and the modernity that emerged in the nineteenth century. Given the complexity of our current challenges, however, is it time to ask whether this paradigm might be better complemented by more holistic and heterodox approaches? Hindmoor A and Taylor TY (2015) Rational Choice (Political Analysis), 2nd edn. London; New York: Palgrave Macmillan. Massumi (2015) The Power at the End of the Economy. Durham: Duke University Press. Brown (2015) Undoing the Demos: Neoliberalism’s Stealth Revolution. New York: Zone Books. Ludovisi SG (ed.) (2015) Critical Theory and the Challenge of Praxis: Beyond Reification. Farnham; Burlington, VT: Ashgate