107 research outputs found
Bioavailabilty of different forms of dissolved silica can affect marine diatom growth
No full textIn this study, we demonstrate that dissolved silica obtained from mineral (crystalline
quartz), biogenic amorphous (diatomaceous earth) and artificial amorphous
sources (Aerosil) influence the growth rate of two marine diatoms,
Chaetoceros sp. and Skeletonema marinoi. Diatoms were reared in four different
experimental conditions in artificial seawater containing either dissolved silica
previously obtained through dissolution of the mineral crystalline quartz or
two amorphous substrates, biogenic diatomaceous earth or artificial Aerosil silica.
Sodium metasilicate was used as control. When the silica in the different
media reached concentrations higher than 107 lM, particles were eliminated by
filtration and the diatom cells were inoculated. Maximum cell density, growth
and silica assimilation rates of both species in the presence of dissolved silica
derived from crystalline quartz and metasilicate were higher than those
obtained with the other silica sources. These results are discussed against the
background of previous geochemical studies that have shown that silica–water
interactions are strictly dependent on the silica polymorphs involved and on
the ionic composition of the solution. Our results demonstrate that the soluble
silicon compounds generated in seawater by crystalline sources are highly bioavailable
compared with those generated by biogenic and amorphous materials.
These findings are potentially of considerable ecological importance and may
contribute to clarifying anomalous spatial and temporal distributions of siliceous
organisms with respect to the presence of lithogenic or biogenic silica
sources in marine environments
Genome complexity of harmful microalgae
No full textDuring the past decade, next generation sequencing (NGS) technologies have provided new insights into the diversity, dynamics, and metabolic pathways of natural microbial communities. But, these new techniques face challenges related to the genome size and level of genome complexity of the species under investigation. Moreover, the coverage depth and the short-read length achieved by NGS based approaches also represent a major challenge for assembly. These factors could limit the use of these high-throughput sequencing methods for species lacking a reference genome and characterized by a high level of complexity. In the present work, the evolutionary history, mainly consisting of gene transfer events from bacteria and unicellular eukaryotes to microalgae, including harmful species, is discussed and reviewed as it relates to NGS application in microbial communities, with a particular focus on harmful algal bloom species and dinoflagellates. In the context of genetic population studies, genotyping-by-sequencing (GBS), an NGS based approach, could be used for the discovery and analysis of single nucleotide polymorphisms (SNPs). The NGS technologies are still relatively new and require further improvement. Specifically, there is a need to develop and standardize tools and approaches to handle large data sets, which have to be used for the majority of HAB species characterized by evolutionary highly dynamic genomes
Gli estratti poliani di Bartolomeo Ceffoni (Firenze, codice Riccardiano 1036)
No full textThe excerpts from Marco Polo’s book collected by Bartolomeo Ceffoni (Florence, MS Ricc. 1036) ·
Bartolomeo Ceffoni is mainly known as the author of some marginal notes to the ms. Florence, Biblioteca Riccardiana, Ricc. 1036, a copy of Dante’s Commedia transcribed by Bartolomeo di Andrea Mazzoni da Lucca. In this same codex, between 1430 and 1432, Ceffoni also collected and copied a series of different texts, among which seventeen excerpts from the Devisement dou monde of Marco Polo (f. 203rb-204rb) studied for the first time by Luigi Foscolo Benedetto in 1928. This essay offers the first complete edition of these excerpts, together with a commentary aimed to place them in context of the history and reception of Marco Polo’s work
Paralytic Shellfish Poisoning toxins from Mediterranean Alexandrium minutum and A. catenella: toxin profile and sxt gene content
No full textParalytic shellfish poisoning (PSP) toxins are potent water-soluble neurotoxins including the parent compound saxitoxin (STX) and a number of its congeners. They are tetrahydropurine derivatives that can be subdivided into three main groups according to substitution of the side chain: carbamoyl-, N-sulfocarbamoyl-, and decarbamoyl-toxins. The carbamoyl derivatives (STX, NEO and GTX1-4) are reported to be the most potent. Due to their accumulation in filter feeding shellfish, PSP toxins can move through the food chain inducing a toxic syndrome in seafood consumers. Symptoms are neurological with rapid onset (30-60 min from ingestion) and include paraesthesia, vertigo, numbness, tingling of the face, tongue, and lip, ataxia, blocking of respiration and even death.
Due to the high risk posed to human health by PSP toxins, a multidisciplinary integrated approach based on liquid chromatography high resolution mass spectrometry (LC-HRMS and MS2) and qPCR-based assay has been used to depict the PSP toxin scenario in the Mediterranean Sea. As the sxtA and the sxtG genes are known as the starting genes of PSP toxin synthesis in dinoflagellates, different populations of the Mediterranean A. minutum from NW Adriatic, Ionian, Tyrrhenian and Catalan Seas were grown in culture and analyzed by qPCR in order to obtain the quantification of these genes. In parallel, LC-HRMS2 analyses were performed on the A. minutum cultured strains and revealed for all of them a toxin profile consisting of only GTX1 and GTX4. Toxin production was in the fg/cell range. Concomitantly with a massive bloom of A. minutum and A. catenella that occurred in Spring 2014 along the Syracuse coasts (Sicily, Italy), four seawater samples were collected and analyzed by LC-HRMS and MS2. The analyzed extracts were found to contain a variety of PSP toxins, namely STX, NEO, the gonyautoxins GTX1-4, the N-sulfocarbamoyl derivatives C1/C2, B1 and B2 and the decarbamoyl ST
La ricezione medievale del Devisement dou monde (secoli XIV-XV)
No full textLa recente monografia di Christine Gadrat-Ouerfelli, Lire Marco Polo au Moyen Age (Brepols, 2015) si segnala negli studi poliani per la sua ricchezza informativa e per l’originalità dell’impostazione: dopo gli studi di Luigi Foscolo Benedetto (1928) e di Consuelo W. Dutschke (1993), si tratta del primo volume che ambisca a dare conto della totalità della tradizione manoscritta del Devisement dou monde, e ad analizzare la storia della tradizione in termini di ricezione.
L’articolo discute le ipotesi presentate dall’autrice, proponendo una riflessione di carattere metodologico e soffermandosi su alcuni esempi specifici in cui la prospettiva genealogica permette una più efficace mise au point delle dinamiche ricezionali.
The recent monograph by Christine Gadrat-Ouerfelli, Lire Marco Polo au Moyen Age (Brepols, 2015), represents a relevant contribution in Polian studies, due to its informative richness and to the originality of its approach. After the studies provided by Luigi Foscolo Benedetto (1928) and Consuelo W. Dutschke (1993), this is the first work that aims to combine an analysis of the Devisement dou monde manuscript tradition from a reception perspective with an overview of its transmission history during the Middle Ages.
The article discusses the hypotheses presented by the author and proposes a methodological reflection, focusing on some specific examples which show how a genealogical approach allows a more effective mise au point of reception dynamics
Testament strażnika wielkiego litewskiego Samuela Kmicica
No full textTestament Samuela Kmicica jest bardzo cennym źródłem do badania mechanizmów awansu społeczno-majątkowego oficerów średniego szczebla armii litewskiej w drugiej połowie XVII wieku. Jego autor był jednym z ważniejszych współpracowników trzech hetmanów – Pawła Jana Sapiehy, Michała Kazimierza Radziwiłła i Kazimierza Jana Sapiehy. Dokument ten zawiera wiele istotnych informacji na temat powiązań klientalnych i finansowych testatora, znacznie też poszerza stan wiedzy o jego działalności fundacyjnej czy też stosunkach rodzinnych. Samuel Kmicic’s last will and testament is a very valuable source for the study of the mechanisms of social and financial advancement of middle-level officers of the Lithuanian army in the second half of the seventeenth century. Its author was one of the most important associates of three hetmans: Paweł Jan Sapieha, Michał Kazimierz Radziwiłł, and Kazimierz Jan Sapieha. The document contains a number of important information about the clientage and financial ties of the testator, and broadens considerably our knowledge of his foundation activities or family relations.Testament Samuela Kmicica jest bardzo cennym źródłem do badania mechanizmów awansu społeczno-majątkowego oficerów średniego szczebla armii litewskiej w drugiej połowie XVII wieku. Jego autor był jednym z ważniejszych współpracowników trzech hetmanów – Pawła Jana Sapiehy, Michała Kazimierza Radziwiłła i Kazimierza Jana Sapiehy. Dokument ten zawiera wiele istotnych informacji na temat powiązań klientalnych i finansowych testatora, znacznie też poszerza stan wiedzy o jego działalności fundacyjnej czy też stosunkach rodzinnych. Samuel Kmicic’s last will and testament is a very valuable source for the study of the mechanisms of social and financial advancement of middle-level officers of the Lithuanian army in the second half of the seventeenth century. Its author was one of the most important associates of three hetmans: Paweł Jan Sapieha, Michał Kazimierz Radziwiłł, and Kazimierz Jan Sapieha. The document contains a number of important information about the clientage and financial ties of the testator, and broadens considerably our knowledge of his foundation activities or family relations
Posidonia oceanica meadows as sponge spicule traps
No full textA quantitative study on the sponge spicules present in a series of horizontal core samples, taken at different levels, from a
1.5 m thick living matte within the Posidonia oceanica meadow of Prelo Bay (Eastern Ligurian Sea), has been performed.
Sponge spicule amounts were evaluated by microscopical and chemical analyses. From the superficial samples the spicule
number decreased until 60–80 cm depth to increase progressively until the deepest studied layer, 140 cm depth. The
same results were obtained from the trend of spicule volume and biogenic silica tested by chemical analysis. Among the
recognisable spicule types, the most common are oxeas, followed by tylostyles, achantostyles and strongyles. However, oxeas,
tylostyles and achantostyles showed the same trend of the entire spicule population, whereas strongyles had an opposite trend
with a maximum value at the 80–100 cm depth. According to the hypothesis that the amount of spicules in the sediment
is proportional or at least related to the sponge biomass existing in the surrounding area, our data suggest that the sponge
assemblage of Prelo Bay should not have been constant in the past 100–200 years. Our hypothesis is that the rapid urban
and industrial development that occurred along the Ligurian coast after the Second World War, particularly in the 1960s,
had an important impact on the sponge assemblages of the area
Bergson – Beckett – Lotman: semiotyczna analiza opowiadania Samuela Becketta "A Wet Night" z tomu "More Pricks than Kicks"
No full textThe article presents a semiotic analysis of a short story entitled “A Wet Night” from Samuel Beckett’s collection More Pricks Than Kicks. The author attempts to analyse the story using the semiotic tools and the concept of semiosphere proposed by Yuri Lotman. In addition to Lotman’s theory, the discussion refers to traces of Henri Bergson’s philosophy, correlated with Beckett’s interests in this matter and highlighted in “A Wet Night”. The aim is to show that both Lotman’s and Bergson’s theories find their application in the selected story.Celem niniejszego artykułu jest analiza semiotyczna opowiadania „A Wet Night” autorstwa Samuela Becketta, które można znaleźć w zbiorze More Pricks Than Kicks. Autor artykułu podejmuje próbę analizy semiotycznej wyżej wymienionego opowiadania, opierając się na koncepcji semiotyka Jurija Lotmana, który zaproponował teorię semiosfery oraz systemów modelujących. Ponadto autor zestawia koncepcję Lotmana z filozofią Henri Bergsona, której echa przejawiają się w opowiadaniu „A Wet Night”, w celu sprawdzenia, czy obie teorie znajdują zastosowania w analizowanym tekście
„Zjadłem dobrą kolację w niezmiernym weselu i wszystkie nasze strachy przeminęły”: jedzenie, picie i towarzystwo jako filozofia eskapizmu w dzienniku Samuela Pepysa
No full textThe Diary of Samuel Pepys offers not only a firsthand account of the political and social life in the 17th-century England, but also a profound insight into the culinary habits of the diarist and his contemporaries. In circumstances of grief or jeopardy, Pepys appears to be searching for ways to obliterate and shun the peril by turning to his favourite pleasure which is food and drink enjoyed in a good company. The author clearly treats the activity as a form of escapism and a social emollient which mitigates feuds and conquers fears. The paper examines Pepys’s life philosophy focusing on those aspects of the Diary where eating and drinking appear as the main sources of the author’s merriness and a technique which helps to overcome the hardships and adversities of everyday life.Dziennik Samuela Pepysa oferuje nie tylko relacje świadka politycznych i społecznych wydarzeń w siedemnastowiecznej Anglii, ale również cenny wgląd w kulinarne nawyki londyńczyków. W sytuacji zagrożenia życia lub w momentach smutku i żalu Pepys szuka sposobów na pocieszenie i zapomnienie, zwracając się często w stronę swojej ulubionej przyjemności: jedzenia i picia w towarzystwie przyjaciół i bliskich. Artykuł jest próbą analizy tych wątków dziennika Samuela Pepysa, w których autor traktuje tę aktywność jako formę eskapizmu w czasach zarazy i wielkiego pożaru w Londynie w roku 1666 oraz jako czynnik łagodzący społeczne napięcia, lęki i niepokoje
Old Polish Single Author Anthologies: From Jan Kochanowski to Samuel Twardowski
No full textArtykuł przybliża swoistość powstawania i funkcjonowania staropolskich antologii jednoautorskich Jana Kochanowskiego, Mikołaja Sępa Szarzyńskiego, Stanisława Grochowskiego, Kaspra Miaskowskiego i Samuela Twardowskiego. Badaniami objęto genezę, układ, przeznaczenie i elementy recepcji twórczości autorów, których teksty wydawano w formie antologii.The article presents the individual nature of the creation and functioning of the old Polish single author anthologies of Jan Kochanowski, Mikołaj Sęp Szarzyński, Stanisław Grochowski, Kasper Miaskowski, and Samuel Twardowski. The research covers the genesis, arrangement, purpose, and elements of the reception of the works of authors, whose texts were published in the form of an anthology
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