101,860 research outputs found
Il Mare Adriatico come connettore di flussi fra Oriente a Occidente: nuove considerazioni sulle anfore Knossos 16 et simils
No full textThis work analyses the distribution of amphora Knossos 16 and similis from the Aegean through the Adriatic Sea, up to the North of Italy and beyond the Alpine region, plotting published and unpublished data (the latter include Butrint, Aquileia, Altinum and the Northern Lagoon of Venice). Furthermore, on the basis of data analysis, we will readdress the issue of its commercial networks and the chronology of its spread across the Adriatic Sea
Effetti dell’incremento termico sul comportamento antipredatorio di giovanili di spigola (Dicentrachus labrax L. )
No full textSound production in a Mudskipper (Periophthalmodon septemradiatus): Implications for the study of Evolutionary Convergence Relatde to the Vertebrate Water-Land Transition
No full textWaste from clam harvesting: a resource for environmental engineering in the Venice lagoon.
No full textClams harvesting has been widespread in the Venice lagoon since Ruditapes philippinarum introduction in 1983. Operations involved in this kind of activity include a sieving phase: operators pick out clams of commercial interest by using manual or mechanical tools. During this phase they obtain a waste that is usually discarded in lagoon.
The Institution responsible of fisheries resources supervision in the Venice lagoon highlighted a management problem related to this kind of waste, that is mostly composed by shells, wood, sediment and different kind of inert materials: in the long term it can accumulate in specific areas covering the seabed and leading to an ecological quality decrease and, consequently, to a lower productivity.
So it is necessary to define a strategy in order to collect this material and to avoid the need for its disposal: we took into account the possibility to use it as a filler, in total or partial replacement of the material currently used, for manufactured devices such as gabions and submerged barriers to be used for banks protection and consolidation in the Venice lagoon as well as for beaches protection from erosion.
In order to do this, we worked in two directions: on the one hand we evaluated the scientific and technical devices feasibility and on the other hand we considered logistical and organisational aspects related to the project. For this reason we related to stakeholders and to local Authorities to better comprehend their issues, and find possible solutions and policies: in particular we were able to define quantities involved, collection, transport and storage strategies, operative problems related to different phases.
This effort made possible the definition of a more effective solution: we were able to integrate ecological and technical issues with logistical and social aspects in order to define a holistic management strategy
Effects of temperature on the antipredator behaviour and on the cholinergic expression in the European sea bass (Dicentrarchus labrax L.) juveniles.
No full textIn this paper, an experimental approach was used to test for the parallel effects of temperature (T) increase on the antipredator behaviour and the cholinergic expression in the juvenile European sea bass (Dicentrarchus labrax L.). The effects of three T treatments (18, 22 and 26°C) were tested on the main behavioural components of the antipredator response towards live aquatic predators and aerial simulated attacks, whereas brain cholinergic expression was evaluated by choline acetyltransferase (ChAT) immunoblotting (Western blot) at the extreme values of the thermal range (18 and 26°C). Antipredator responses towards a live fish were analysed over pre-exposure and exposure phases within a short temporal scale (20 s before and after the stimulus). The results suggest that T modulates several quantitative components of the antipredator behaviour. The mean shoaling index (shoal cohesiveness) was higher at 22°C than at 18 and 26°C during both the pre-stimulus and the exposure phase. Conversely, the mean distances from the predator and the tank bottom were, respectively, lower and higher at 26°C than in the other two treatments. In regard to the antipredator response on the aerial stimulus, comparisons across treatments revealed statistically significant differences between fish performing freezing or latency to recovery, suggesting that the fright reaction has a higher persistence at the coldest T (18°C) than at 22 and 26°C. Western blot analysis revealed a reduction in brain ChAT expression in fish acclimated to 26°C compared to those at 18°C. Results were discussed in the light of the relationships between behavioural traits, metabolism and their consequences on the population level, as a response to climate change in coastal habitats. © 2013 Blackwell Verlag GmbH
Feeding behaviour of larval European sea bass (Dicentrarchus labrax L.) in relation to temperature and prey density
No full textThe feeding behaviour of larval European sea bass (Dicentrarchus labrax, L.) was analysed in relation to temperature and prey
density under controlled laboratory conditions with the aim to assess the ability of larval fish to change the feeding tactic as a
response to environmental changes. Larvae were acclimated for 20 days at three different temperatures (19, 22 and 26°C), and
their feeding behaviour was then video-recorded in experimental trials, at two prey densities, consisting of swarms of 400/l
and 1440/l Artemia nauplii. Results showed that there was a significant effect of the interaction between temperature and prey
density on the proportion of swimming activity that was reduced at the high temperature-high prey density combination. This
suggested a switching in the larval feeding behaviour from an active to an ambush tactic, when the temperature reached 26°C
and the prey density was 1440 /l Artemia nauplii. These results are consistent with the current literature on fish larval behaviour
in showing that the foraging tactic can be modulated by the interaction of different abiotic and biotic factors characterising the
rearing environment
Acoustic Communication at the Water's Edge: Evolutionary Insights from a mudskipper
No full textCoupled behavioural observations and acoustical recordings of aggressive dyadic contests showed that the mudskipper
Periophthalmodon septemradiatus communicates acoustically while out of water. An analysis of intraspecific variability
showed that specific acoustic components may act as tags for individual recognition, further supporting the sounds’
communicative value. A correlative analysis amongst acoustical properties and video-acoustical recordings in slow-motion
supported first hypotheses on the emission mechanism. Acoustic transmission through the wet exposed substrate was also
discussed. These observations were used to support an ‘‘exaptation hypothesis’’, i.e. the maintenance of key adaptations
during the first stages of water-to-land vertebrate eco-evolutionary transitions (based on eco-evolutionary and
palaeontological considerations), through a comparative bioacoustic analysis of aquatic and semiterrestrial gobiid taxa.
In fact, a remarkable similarity was found between mudskipper vocalisations and those emitted by gobioids and other
soniferous benthonic fishes
Bibliographie Hilarion G. Petzold 1958 – 2009 mit Anhang als Einführung
No full textDieses Archiv enthält die Gesamtbibliographie der Werke des Autors nebst einiger Texte „Über H. G. Petzold“ im Schlussteil der Bibliographie sowie einen Anhang mit einer Einführung in die Architektur des Werkes in seinem wissenslogischen Aufbau als Ausarbeitung seines „Tree of Science Modells“ (2007).This archive contains the complete bibliography of the author and some texts about H. G. Petzold, moreover an epilogue with an introduction to the architecture of the works in its epistemological structure and composition and as an elaborations of Petzold’s „Tree of Science Modell (2007).https://www.fpi-publikation.de/polyloge/01-2009-petzold-h-g-gesamtbibliographie-h-g-petzold-1958-2009-updating-november2009/peerReviewedpublishedVersio
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Behavioural and physiological effects of temperature increase on European sea bass (Dicentrarchus labrax L.) and gilthead seabream (Sparus aurata L.)
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