36 research outputs found
Nocturnal feeding under artificial light conditions by Brown-Hooded Gull (Larus Maculipennis) in Puerto Madryn harbour (Chubut province, Argentina)
No full textThis paper describes nocturnal, marine feeding behaviour in the Brown-hooded Gull (Larus maculipennis) in November 2009. The gulls assembled at night at the end of a long pier, running 800 m offshore into the Golfo Nuevo, at Puerto Madryn, Chubut Province, Argentina. Powerful lights predictably lighted the water around the end of the pier and attracted many small prey animals to the surface. Several hundreds of gulls, presumed to be local breeders, came every night to feed on this bounty, using various feeding techniques and taking several prey species and sizes. Potential prey items were caught to be identified by vertical plankton hauls. The gulls most likely took relatively large Isopoda (Idothea sp.), Polychaeta (Platynereis sp.) and fish larvae (Patagonotothen sp.) as well as smaller crustaceans, mostly Amphipoda (Phoxocephalidae) and Mysidacea. The gulls caught small prey items while swimming, by rapid surface pecking, while they hunted the larger prey species by flying low over the water and performing shallow, vertical plunge-dives. During daylight, only few gulls ventured from land into the bay, indicating that they took advantage of the nocturnal feeding opportunity, facilitated by artificial lighting. The clear short-term gain of exploiting this novel foraging opportunity may be offset by potential threats such as increased vulnerability to predators or contamination by oil spills from ships moored along the pier
Messa a punto di un protocollo per l'estrazione e l'analisi di composti fenolici in varietà di Triticum aestivum L.
No full textLinda Olmi(1), Leonardo Setti(2), Giuseppe Montevecchi(1), Elisabetta Sgarbi*(3)
MESSA A PUNTO DI UN PROTOCOLLO PER L’ESTRAZIONE E L’ANALISI DI COMPOSTI FENOLICI IN VARIETÀ DI TRITICUM AESTIVUM L
Presso il Centro Interdipartimentale “Biogest-Siteia” dell‟Università degli Studi di Modena e Reggio Emilia è attivo dal 2011 un progetto che prevede la realizzazione di una Banca del Germoplasma per la conservazione e la valorizzazione di cereali, in particolare di varietà di frumento tenero (Triticum aestivum L.). Oltre alla raccolta, alla conservazione e all‟analisi morfologica delle varietà, tra gli scopi della Banca vi è quello di caratterizzare le varietà conservate anche da un punto di vista metabolico. Attualmente la Banca dispone di oltre 150 accessioni, tutte caratterizzate dal punto di vista morfometrico sulla base degli standard internazionali di descrizione del grano (IBPGR 1985). Di recente è stato elaborato un protocollo di estrazione e di analisi della componente fenolica delle cariossidi al fine di rilevare eventuali differenze quali-quantitative tra le accessioni. Dopo la macinazione di cariossidi sane ed integre, l‟estrazione è stata effettuata con una soluzione di etanolo 80%. L‟estratto, portato a secco con evaporatore rotante, è stato in seguito riportato a volume con una soluzione di acqua, etanolo assoluto, acetonitrile, trietilammina 91.9:5.0:3.0:0.1. Gli estratti così ottenuti sono stati separati e quantificati mediante cromatografia liquida con analizzatore di massa a triplo quadrupolo (LC-MS/MS Triplo quadrupolo 6410B - Agilent Technologies) presso il Centro Interdipartimentale Grandi Strumenti (CIGS) dell‟Università di Modena e Reggio Emilia. La colonna utilizzata per le analisi è una RP C18 Poroshell 120 (Phenyl Hexyl, Agilent Technologies). La quantificazione è stata eseguita mediante il metodo della standardizzazione esterna e sono stati determinati la ripetibilità ed i limiti di rilevabilità (LOD) e di quantificazione (LOQ). I campioni, analizzati in triplo, sono stati fatti correre in ordine casuale e per l‟elaborazione dei cromatogrammi è stato utilizzato il Software Quantitative Analysis B.05.00 (Agilent Technologies). Per alcuni fenoli, come acido vanillico, acido trans-ferulico, acido siringico, acido sinapico, acido caffeico,vanillina, acido p-cumarico, acido t-cinnamico e apigenina sono disponibili i dati quantitavi relativi a 33 varietà. Bibliografia citata: IBPGR (1985). Descriptors for Wheat (Revised), Roma, pp. 44. Gli Autori ringraziano la “Fondazione Cassa di Risparmio di Modena” per il finanziamento destinato all‟acquisto del LC-MS/MS Triplo quadrupolo 6410B - Agilent Technologies, Laboratorio Spettrometria di Massa, presso il Centro Interdipartimentale Grandi Strumenti (CIGS) dell‟Università di Modena e Reggio Emilia.
Indirizzo Autori: (1) Centro Interdipartimentale BIOGEST-SITEIA, v. Amendola 2, Padiglione BESTA, Reggio Emilia, Italy; (2) Dipartimento di Scienze della vita, Università di Modena e Reggio Emilia, v. Amendola 2, Padiglione BESTA, Reggio Emilia, Italy; (3) Dipartimento di Scienze della vita, Università di Modena e Reggio Emilia, v. Amendola 2 Padiglione BESTA / Centro Interdipartimentale BIOGEST-SITEIA, v. Amendola 2, Padiglione BESTA, Reggio Emilia, Italy
Corresponding Author: Elisabetta Sgarbi ([email protected]
Prey harvests of seabirds reflect pelagic fish and squid abundance on multiple spatial and temporal scales
No full textMany studies have demonstrated relationships between seabird prey harvests and fishenes catches. These correlations have for the most part been found at scales from 10s to 100s of kilometers within foraging ranges around seabird breeding colonies. In the present study, we investigated associations between the prey harvests of northern gannets Sula bassana at a large breeding colony off
the northeast coast of Newfoundland and the catches of the inshore Newfoundland fishery at different spatial scales and time intervals. Significant correlations occurred between the seabirds' and the humans' catches of mackerel Scomber scombrus and short-finned squid Illex illecebrosus from 1977 through 1992. The relationships for squid were stronger over larger geographic areas than were those
for mackerel. The associations for both squid and mackerel reflected abundance/availability around the colony, at a larger scale near the gannets' maximum foraging range (e.g. -200 km), and for the entire Newfoundland region (1000s of kilometers). These correlations were significant at August vs August and August vs annual time intervals. The gannets' landings of squid were also associated with
fishery-independent, research survey indices of squid abundance over thousands of kilometers. The robustness of these relationships indicates that levels of pelagic prey harvest by seabirds can provide reliable indices of prey abundance within and outside reproductive seasons and foraging ranges around breeding colonies. Similar relationships are predicted between seabird and human fisheries that are directed at migratory 'warm-water' pelagic prey that move into cold and high latitude oceanographic regions
Blood pressure waveform analysis by means of wavelet transform
No full textThe assessment of cardiovascular function by means of arterial pulse wave analysis (PWA) is well established in clinical practice. PWA is applied to study risk stratification in hypertension, with emphasis on the measurement of the augmentation index as a measure of aortic pressure wave reflections. Despite the fact that the prognostic power of PWA, in its current form, still remains to be demonstrated in the general population, there is general agreement that analysis and interpretation of the waveform might provide a deeper insight in cardiovascular pathophysiology. We propose here the use of wavelet analysis (WA) as a tool to quantify arterial pressure waveform features, with a twofold aim. First, we discuss a specific use of wavelet transform in the study of pressure waveform morphology, and its potential role in ascertaining the dynamics of temporal properties of arterial pressure waveforms. Second, we apply WA to evaluate a database of carotid artery pressure waveforms of healthy middle-aged women and men. Wavelet analysis has the potential to extract specific features (wavelet details), related to wave reflection and aortic valve closure, from a measured waveform. Analysis showed that the fifth detail, one of the waveform features extracted applying the wavelet decomposition, appeared to be the most appropriate for the analysis of carotid artery pressure waveforms. What remains to be assessed is how the information embedded in this detail can be further processed and transformed into quantitative data, and how it can be rendered useful for automated waveform classification and arterial function parameters with potential clinical applications
Linking predator diet and prey availability: common murres and capelin in the Northwest Atlantic
No full textShayzar I. The fortification of the citadel
No full textThis book presents the results obtained from the historical and
archaeological investigations carried out in the framework of a
project centred on the site of Shayzar, in Central Syria: Shayzar
Project: study of the fortified settlement in Bilad al-Sham, under the direction of the author. On the basis of a detailed analysis of the archaeological evidence, and of the study of the written documentation available, the book examines the origins and the development of this fortification, especially in relation to the most crucial periods as regard as the building of the citadel, i.e., the span of time that stretches from the 10th to the 13th centuries; it also discusses the development of building
techniques in the context of military architecture.
Other contributors are Nadia Montevecchi, Fabrizio Antonelli, Jean-Claude Bessac, Roberta Giunta, Hugh Kennedy, Lorenzo Lazzarini, Serena Martucci di Scarfizzi, Cinzia Tavernari and Niccolo' Zorzi
Crepuscular foraging by a pursuit-diving seabird: tactics of common murres in response to the diel vertical migration of capelin
No full textFinite Element Modelling of Wire-arc-additive-manufacturing Process
No full textAbstractWire-Arc-Additive-Manufacturing (WAAM) is an Additive-Manufacturing (AM) process, allowing to produce metal components layer by layer by means of Gas-Metal-Arc-Welding (GMAW) technology. The advantages of this technology are the capability to create large parts with a higher deposition rate with respect to other AM technologies. Despite these great benefits, WAAM components are affected by severe distortions and residual stresses issues. Finite element process simulation provides an efficient way to study mitigation strategies for such issues. In this paper, a WAAM modelling strategy is proposed based on a novel heat source model that takes into account the actual power distribution between filler and base materials. In order to prove the effectiveness of proposed modelling, an experimental validation is provided by comparing the measured distortions of a WAAM tests-case with the simulated ones, highlighting the accuracy of proposed model
Optimization of WAAM Deposition Patterns for T-crossing Features
No full textAbstractAmong emerging additive manufacturing technologies for metallic components, WAAM (Wire and Arc Additive Manufacturing) is one of the most promising. It is an arc based technology characterized by high productivity, high energy efficiency and low raw material cost. Anyway, it has some drawbacks limiting its diffusion in the industry. One is the open issue about the layer deposition strategy that must be manually optimized in order to reduce as possible the residual stress and strains, efficiently matching the geometrical characteristics of the component to build and assure a constant height for each layer. This work deals with the definition of deposition paths for WAAM. The choice of a path must be carried out as a compromise between productivity and material usage efficiency. In the present paper, the process to select an optimized strategy for the manufacturing of T-crossing features will be shown
