387 research outputs found
Effects of organic and metallorganic pollutants on European gastropod species
No full textIl presente progetto di Dottorato sviluppa due diverse linee di ricerca volte a verificare la possibilità di utilizzare comuni molluschi gasteropodi come 'organismi sentinella' per programmi di biomonitoraggio basati sull'approccio 'multibiomarkers' ed il possibile contributo dei PCB nell'induzione del fenomeno di Imposex nei gasteropodi. Relativamente alla prima linea di ricerca sono state condotte due indagini in campo volte a verificare la capacità di una selezionata batteria di 'biomarker' (Intersex/Imposex, Comet assay, MN assay, NRR assay e FRAP assay) di discriminare popolazioni naturali di 'Littorina littorea' e 'Hexaplex trunculus' sottoposte a differenti condizioni di stress. La caratterizzazione tossicologica è stata effettuata in parallelo alla descrizione chimica del bioaccumulo di comuni inquinanti organici (PAH, OTC, PCB e OCP). Relativamente alla seconda linea di ricerca sono stati condotti tre esperimenti "pilota" volti a definire alcuni aspetti del disegno sperimentale di un'esposizione cronica a PCB di individui della specie 'Nassarius nitidus' mediante la dieta.The present PhD project develops two research lines addressed to verify the suitability of common gastropod species as 'sentinel organisms' for multibiomarkers-based monitoring programs and the possible involvement of PCB in the induction of Imposex phenomenon in gastropods. In the context of the first research line two fiel surveys were carried out in order to assess the potential of selected suites of biomarkers (Intersex/Imposex, Comet assay, MN assay, NRR assay and FRAP assay) in discriminating natural populations of 'Littorina littorea' and 'Hexaplex trunculus' experiencing different stress conditions. The toxicological characterization was coupled with the chemical description of organic contaminants' bioaccumulation pattern (PAH, OTC, PCB and OCP). For the second research line three "pilot" tests were carried out for setting the experimental design of a long-term dietary exposition of 'Nassarius nitidus' specimens to PCB environmental concentrations
Handling concentration data below the analytical limit in environmental mixture risk assessment: A case-study on pesticide river monitoring
No full text: Aquatic organisms are exposed to ever-changing complex mixtures of chemicals throughout their lifetime. Component-Based Mixture Risk Assessment (CBMRA) is a well-established methodology for water contaminant-mixture management, the use of which is growing due to improved access to reference ecotoxicity data and extensive monitoring datasets. It enables the translation of measured exposure concentrations of chemicals into biological effect values, and thus to quantitatively estimate the risk of the whole water sample (i.e., as a mixture). However, many factors can bias the final risk decision by impacting the risk metric components; thus, a careful design of the CBMRA is needed, taking into primary consideration the specific features of the dataset and mixture risk assessment assignments. This study systematically addressed the effects of the most common approaches used for handling the concentrations of chemicals below the limit of detection/quantification (LOD/LOQ) in CBMRA. The main results included: i) an informed CBMRA procedure that enables the tracking of the risk decisions triggered by substances below LOD/LOQ, ii) a conceptual map and guidance criteria to support the selection of the most suitable approach for specific scenarios and related interpretation; iii) a guided implementation of the informed CBMRA on dataset of pesticide concentrations in Italian rivers in 2020 (702,097 records)
Organotin compounds in touristic marinas of the northern Adriatic Sea: occurrence, speciation and potential recycling at the sediment-water interface
No full textButyltin compound (BTC) contamination was evaluated in two north Adriatic marinas, San Rocco (Italy) and Lucija (Slovenia).
BTC sedimentary concentrations (121 ± 46 and 352 ± 30 ng Sn g−1 in San Rocco and Lucija, respectively) evidenced the past use of antifouling paints, confirmed by the reduced tributyltin content (~ 46%) with respect to the sumof BTC. Elemental and organic carbon isotopic (δ13C) analyses of bulk sediments and its lipid and humic substances were performed in order to evaluate their role in BTC partitioning and preservation. The δ13C of sedimentary bulk and refractory organic matter suggested that diagenetic processes could play a role in the preservation or release of pollutants. No contamination was found in water collected from the benthic chamber and thus, fluxes at the sediment-water interface were not assessed, except for MBT efflux at Lucija (28.9 ng Sn m−2 day−1). Nevertheless, BTC concentrations in porewaters (up to 75 ng Sn l−1) and rather low sediment-porewater partitioning coefficients (Kd) with respect to the data reported in the literature would suggest a potential risk of the reintroduction of BTC into the water column at both sites: at Lucija, sedimentary contamination is high despite the greater Log Kd, whilst at San Rocco, the low BTC concentration is associated with a reduced sediment affinity
Imposex levels and butyltin compounds (BTs) in Hexaplex trunculus (Linnaeus, 1758) from the northern Adriatic Sea (Italy): Ecological risk assessment before and after the ban
No full textVoces y silencios en Castelli di rabbia (1991), Oceano mare (1993) y Seta (1996) de Alessandro Baricco.
No full textPara el presente trabajo se recorta un corpus de tres obras de Alessandro Baricco: Castelli di rabbia (1991),1 Oceano mare (1993)2 y Seta (1996)3. Las novelas elegidas fueron escritas en los años noventa, pertenecen a un período en que el autor ubica las historias narradas en el siglo XIX; en dos de las novelas seleccionadas (Castelli di rabbia y Oceano mare), las acciones transcurren en ciudades imaginarias; en la tercera, si bien aparecen lugares geográficos reconocibles, la forma en que se construyen en la ficción los acerca más a las ciudades imaginarias que a los espacios físicos de la realidad empírica.
El eje temático de esta investigación está planteado a través del análisis de las voces y silencios en las novelas que conforman el corpus, desde la perspectiva de Mijail Bajtin. Más específicamente, abordaremos este tema a través del análisis de los personajes: el señor Rail y Jun, en Castelli di rabbia; Thomas / Adams y Savigny, en Oceano mare; Hérvé, la joven japonesa y Hélène, en Seta; y de algunos cronotopos: el viaje, que atraviesa las tres novelas, y algunos específicos que se relevan en cada texto, como el tren y el cristal en Castelli di rabbia; el mar y la pintura en Oceano mare; Japón y la seda en Seta
Periwinkle (<i>Littorina littorea</i>) as a Sentinel Species: A Field Study Integrating Chemical and Biological Analyses
No full textLa integración económica latinoamericana y caribeña en la década de los noventa: un panorama
No full text[ES] En el presente artículo se analizan los principales cambios que se han producido en el proceso integrador latinoamericano y caribeño, a lo largo de la década de los noventa, así como sus implicaciones para la economía regional. El autor focaliza su análisis en tres aspectos que caracterizan esa evolución: la revitalización del proceso de integración a nivel continental, la convergencia entre diferentes espacios económicos y la incidencia de estos aspectos en el modelo de desarrollo regional.[EN] This article anlayses main changes during the present decade in latin american and caribbean integration process, as well as its implications on regional economy. The author focuses on three aspects that characterize this evolution: continental revitalization of the integration process, convergence among different economical arcas and incidence of these aspects on the regional development model
La integración económica latinoamericana y caribeña en la década de los noventa: un panorama
No full textRESUMEN: En el presente artículo se analizan los principales cambios que se han producido en el proceso integrador latinoamericano y caribeño, a lo largo de la década de los noventa, así como sus implicaciones para la economía regional. El autor focaliza su análisis en tres aspectos que caracterizan esa evolución: la revitalización del proceso de integración a nivel continental, la convergencia entre diferentes espacios económicos y la incidencia de estos aspectos en el modelo de desarrollo regional.ABSTRACT: This article anlayses main changes during the present decade in latin american and caribbean integration process, as well as its implications on regional economy. The author focuses on three aspects that characterize this evolution: continental revitalization of the integration process, convergence among different economical arcas and incidence of these aspects on the regional development model.</p
Dissolution and bandgap paradigms for predicting the toxicity of metal oxide nanoparticles in the marine environment: an in vivo study with oyster embryos
No full textThis is the author accepted manuscript. The final version is available from Taylor & Francis via the DOI in this recordDissolution and bandgap paradigms have been proposed for predicting the ability of metal oxide nanoparticles (NPs) to induce oxidative stress in different in vitro and in vivo models. Here, we addressed the effectiveness of these paradigms in vivo and under conditions typical of the marine environment, a final sink for many NPs released through aquatic systems. We used ZnO and MnO2 NPs as models for dissolution and bandgap paradigms, respectively, and CeO2 NPs to assess reactive oxygen radical (ROS) production via Fenton-like reactions in vivo. Oyster embryos were exposed to 0.5-500 μM of each test NP over 24 h and oxidative stress was determined as a primary toxicity pathway across successive levels of biological complexity, with arrested development as the main pathological outcome. NPs were actively ingested by oyster larvae and entered cells. Dissolution was a viable paradigm for predicting the toxicity of NPs in the marine environment, whereas the surface reactivity based paradigms (i.e. bandgap and ROS generation via Fenton-like reaction) were not supported under seawater conditions. Bio-imaging identified potential cellular storage-disposal sites of solid particles that could ameliorate the toxicological behavior of non-dissolving NPs, whilst abiotic screening of surface reactivity suggested that the adsorption-complexation of surface active sites by seawater ions could provide a valuable hypothesis to explain the quenching of the intrinsic oxidation potential of MnO2 NPs in seawater.This project was funded by the European Union Horizon 2020 research and innovation program under Marie Sklodowska-Curie grant agreement No 655134 and NERC FENAC access grant No PR120021. TG acknowledges support from NERC grant NE/N006178/1
Estrategias cubanas para el empleo femenino en los noventa : un estudio con mujeres profesionales
No full textEl artículo intenta demostrar cómo Cuba desarrolló en los noventa un proyecto alternativo al neoliberalismo en el terreno del empleo femenino. Para ello la autora resume resultados de varios estudios de caso que emprendió con obreras en empleos tradicionales y no tradicionales femeninos entre 1985 y 1998, para explicar el fenómeno de las mujeres profe-sionales cubanas, que constitutye el eje de este trabajo. Indaga, entre una muestra de ellas, cuáles fueron las estrategias que elaboraron en los noventa para mantenerse empleadas y reproducir diariamente la vida de sus familias; cómo influyó el hecho de ser profesionales en sus capacidades para tomar decisiones; cuánto han contribuido las mujeres profesionales a cambiar la ideología de género de los hombres cubanos, y qué ha significado ser profesionales en su vida personal.The article focuses on how Cuba developed an alternative project to neoliberalism during the 90's to solve problems concerning women's employment. The author summarizes her findings in several case studies she carried out with women employed in traditional and non traditional feminine jobs between 1985 and 1998, in order to explain the development of women professionals, which is the main topic of the present work. Based in a sample of women professionals, she studies which were the strategies they worked out during the 90's to keep their jobs and to daily reproduce the lives of their families; how the fact of being professional women influenced their abilities in decision making; up to what degree they have contributed to change Cuba men's gender ideologies, and what being professionals has meant to their personal lives
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