51 research outputs found

    Biomarcadores etológicos no invasivos de estrés ambiental: estudio comparativo en dos teleosteos de ecosistemas de la región pampeana argentina

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    Mediante un dispositivo de registro automático se estudió el efecto de la exposición a soluciones subletales de Cd2+ (0.3 mg. L'1) sobre algunos parámetros etológicos de juveniles de Cyprinus carpió (carpa común) y de Astyanax fasciatus (“mojarra”). Se evaluó el efecto del metal sobre la actividad natatoria total y las preferencias altitudinales y laterales de los peces. Los tres parámetros se registraron simultáneamente mediante un dispositivo original. Se evaluaron los niveles “normales” o estándar de dichos parámetros (los peces en agua potable, control) y los alcanzados por los mismos individuos tras su exposición al tóxico de referencia (Cd). El metal provocó una depresión de la actividad natatoria total alcanzando una magnitud comparable en ambas especies. La preferencia altitudinal, también resultó modificada: C. carpió se halló con mayor frecuencia en la capa superior de los acuarios mientras que A. fasciatus se ubicó en las inferiores. En cuanto a la preferencia lateral, los individuos de ambas especies evitaron la franja vertical donde se producía el goteo de la solución de Cd; si bien esta respuesta espacial de los animales no siguió un patrón definido fue más marcada en las carpas. Todas las respuestas se pusieron de manifiesto inmediatamente después de haberse iniciado la exposición al Cd. El método resultó sensible y apto para el seguimiento de los parámetros etológicos seleccionados. Se concluye que la actividad natatoria y la ubicación espacial de las especies estudiadas, entre otros indicadores, pueden ser considerados como biomarcadores de toxicidad acuática.By means of an automatic recording device, the eífects of the exposure to sublethal Solutions of Cd2+ (0.3 mg. L2) on some ethological parameters of juvenile Cyprinus carpió (common carp) and Astyanaxfasciatus. The effect of the metal was evaluated through three parameters: the total swimming activity and the spatial (lateral and altitudinal) preferences, relative to Controls (fish kept in tap water); they were registered simultaneously by means oían original device. There were determined successively the “normal” or standard levels of those parameters in control fish and those reached by the same individuáis aftertheir exposure to thereferencetoxic (Cd). In both species the metal caused a depression of the total swimming activity in a comparable magnitude. The altitudinal preference was also modified: C. carpió was found more frequently in the superior layer of the aquaria while A. fasciatus was found in the inferior ones. For the lateral preference, the individuáis of both species showed an avoidance behavior of the site of the aquaria where the Cd Solutions was dripping. This response of the animáis didn't follow a defined pattem, but was more marked in the carps. All the evaluated responses to the toxic were detected immediately after the beginning of the exposure to Cd. The method proved to be sensitive and apt for the monitoring of the measured behavioural parameters which makes it a promising tool for biomonitoring purposes. We concluded that the swimming activity and the spatial location preferences of the studied species, among other, may be considered as biomarkers of aquatic toxicity

    X-Ray Microscopy: Preparations for Studies of Frozen Hydrated Specimens

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    X-ray microscopes provide higher resolution than visible light microscopes. Wet, biological materials with a water thickness of up to about 10 μm can be imaged with good contrast using soft X-rays with wavelengths between the oxygen and carbon absorption edges (at 24 and 43 Å). The Stony Brook group has developed and operates a scanning transmission X-ray microscope (STXM) at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory. The microscope is used for imaging with a current resolution of 50 nm, and for elemental and chemical state mapping. Radiation damage imposes a significant limitation upon high resolution X-ray microscopy of room temperature wet specimens. Experience from electron microscopy suggests that cryo techniques allow vitrified specimens to be imaged repeatedly. This is due to the increased radiation stability of biological specimens in the frozen hydrated state. Better radiation stability has been shown recently with a cryo transmission X-ray microscope developed by the University of Gottingen, operating at the BESSY storage ring in Berlin, Germany. At Stony Brook, we are developing a cryo scanning transmission X-ray microscope (CryoSTXM) to carry out imaging and spectra-microscopy experiments on frozen hydrated specimens. This article will give an outlook onto the research projects that we plan to perform using the CryoSTXM

    New insights to assess the consolidation of stone materials used in built heritage: the case study of ancient graffiti (Tituli Picti) in the archaeological site of Pompeii

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    Tituli Picti are an ancient form of urban graffiti very common in the archaeological site of Pompeii (Naples, South—Italy). They are generally made of red pigments applied on walls of Campanian ignimbrite. This paper deals with a scientific investigation aimed to their conservation. This is a challenging task since it requires a multidisciplinary approach that includes restorers, archaeologists and conservation scientists. The study has provided suggestions on the proper way to conserve Tituli Picti over time. In the present work, several specimens of Campanian ignimbrite were painted with red earth pigment; lime and Arabic gum have been used as binders as well. Such painted stones were treated with three consolidants: a suspension of reactive nanoparticles of silica, ethyl silicate and an acrylic microemulsion. Treated and untreated specimens were subjected to thermal aging, artificial solar radiation and induced crystallization decay. It has been assessed the colorimetric variations induced by treatments. Moreover, the micromorphologic features of the consolidated surfaces have been highlighted by means of electron microscope observations. The scotch tape test allowed to compare the superficial cohesion induced by the three used products. According to the results, ethyl silicate seems to represent the most successful product

    Synchrotron Microtomography and Neutron Radiography Characterization of the Microstruture and Water Absorption of Concrete from Pompeii

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    There is renewed interest in using advanced techniques to characterize ancient Roman concrete. In the present work, samples were drilled from the "Hospitium" in Pompeii and were analyzed by synchrotron microtomography (uCT) and neutron radiography to study how the microstructure, including the presence of induced cracks, affects their water adsorption. The water distribution and absorptivity were quantified by neutron radiography. The 3D crack propagation, pore size distribution and orientation, tortuosity, and connectivity were analyzed from uCT results using advanced imaging methods. The concrete characterization also included classical methods (e.g., differential thermal-thermogravimetric, X-ray diffractometry, and scanning electron microscopy). Ductile fracture patterns were observed once cracks were introduced. When compared to Portland cement mortar/concrete, Pompeii samples had relatively high porosity, low connectivity, and similar coefficient of capillary penetration. In addition, the permeability was predicted from models based on percolation theory and the pore structure data to evaluate the fluid transport properties

    Review of available national guidelines for obstetric anal sphincter injury.

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    INTRODUCTION AND HYPOTHESIS: Obstetric anal sphincter injuries (OASIs) are the most severe form of perineal trauma with potentially devastating effects on a mother's quality of life. There are various national guidelines available for their management. The aim of this study was to review and compare recommendations from published national guidelines regarding management and prevention of OASI. METHODS: We searched the PUBMED, EMBASE, MEDLINE, CINAHL and COCHRANE databases from January 2008 till October 2019 using relevant Medical Subject Headings (MeSH), including all subheadings. The guideline characteristics were mapped and methodological quality assessed with the Appraisal of Guidelines for Research and Evaluation (AGREE) II tool by three independent reviewers. To compare the methodological quality of the guidelines, the interpretation of the six domain scores were taken into consideration. By consensus of the authors, a score of 70% was taken as a cut-off, and scores above this were considered 'high quality'. RESULTS: Thirteen national guidelines on perineal trauma were included and analysed. Nine of these were specific to OASI. There is wide variation in methodological quality and evidence used for recommendations. AGREE scores for overall guideline assessment were > 70% in eight of the guidelines, with Australia-Queensland, Canada, the UK and USA scoring highest. CONCLUSIONS: The wide variation in methodological quality and evidence used for recommendations suggests that there is a need for an agreed international guideline. This will enable healthcare practitioners to follow the same recommendations, with the most recent evidence, and provide evidence-based care to all women globally

    Culti greci in occidente. II. Eraclea

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    Il volume è dedicato ai culti della polis magnogreca di Heraklea, trattanti in base a tutta la documentazione disponibile: storica e epigrafica (Prandi), archeologica (Osanna) e numismatica (Siciliano). Il regesto sui vari luoghi sacri viene preceduto da un inquadramento storico-topografico sulle vicende insediative che hanno interessato il comprensorio tra età arcaica ed ellenistica

    L'insediamento fortificato di Satrianum in età angioina. Fonti, strutture materiali e documenti archeologici di un centro di potere nella Valle del Melandro (PZ), in F. Sogliani, M. Osanna, L. Colangelo, A. Parente, Gli spazi del potere civile e religioso dell'insediamento fortificato di Torre di Satriano in età angioina

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    The medieval fortified settlement of Satriano (Potenza) has been studied from 2005, due to a huge and intense archaeological investigation headed by the School of Specialization in Archaeology of Matera, under a large project sponsored by the Region of Basilicata and the Municipality of Tito (PZ). It represents an “Archaeology of power" case-study, particularly significant for its structural characteristics, its location and the impressive articulation of its planimetric organization. With the recent widespread program of archaeological researches it was possible to comprehend the development of different phases in the chronological sequence, form the site sorted out to establish a structured system of territorial defence and control by the Normans (the first written sources date back to the end of XIIth century) to its desertion in post-medieval era. In the settlement it is possible to recognize an upper area, on the top of the hill, enclosed by walls, as the hierarchically most important space, including inside the seat of civil power - the big square tower – as the one of its' religious authority - the “Cathedral” and the fortified village developed on the slopes of the hill. Considerable seems to be the archaeological evidences related to the Angevin period, whose demographic situation registers an increase of “fuochi” from 151 to 224 in the second half of the XIIIth century. In this period the Cathedral was restored and in the cemetery of the religious area we observe an implementation of the richest tombs. The settlement was abandoned in the last decades of the XVth century, after the strong economic crisis of XIVth and XVth century, which will have serious consequences on the human settlement in the region of Basilicata. On the contrary, some sources testifies that the diocesan seat moved from Satriano to Campagna only in 1525. It is possible that even after the desertion of the medieval settlement, the Cathedral dedicated to St. Stephen, probably affected by some restoration activities, still play an important role in the territory, going on to celebrate the major religious solemnities
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