951 resultados para mud wedge
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Little is known about long-term ecological responses in lakes following red mud pollution. Among red mud contaminants, arsenic (As) is of considerable concern. Determination of the species of As accumulated in aquatic organisms provides important information about the biogeochemical cycling of the element and transfer through the aquatic food-web to higher organisms. We used coupled ion chromatography and inductively coupled plasma mass spectrometry (ICP-MS) to assess As speciation in tissues of five macrophyte taxa in Kinghorn Loch, UK, 30 years following the diversion of red mud pollution from the lake. Toxic inorganic As was the dominant species in the studied macrophytes, with As species concentrations varying with macrophyte taxon and tissue type. The highest As content measured in roots of Persicaria amphibia (L.) Gray (87.2 mg kg-1) greatly exceeded the 3 - 10 mg kg-1 range suggested as a potential phytotoxic level. Accumulation of toxic As species by plants suggested toxicological risk to higher organisms known to utilise macrophytes as a food source.
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Thesis (Master's)--University of Washington, 2016-08
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Thesis (Master's)--University of Washington, 2016-08
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Knowledge of the marine soils properties, together with hydrodynamic and climatic data, plays an important role for a better understanding of the dynamic behavior of sandy and muddy coasts. This paper deals with reporting and basic interpretation of two campaigns of exploration and characterization of the mud of Cassino Beach, southern Brazil, carried out during the years of 2004 and 2005. Samples were obtained by means of cores collected at some locations offshore, and were submitted to various laboratory geotechnical tests, including determination of the physical index, grain size distribution, Atterberg limits, and shear resistance by both triaxial and shear vane tests. Results confirm the existence of a very soft soil deposit offshore Cassino Beach, highly plastic, compressible, and viscous, forming an important database for further studies.
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The Mediterranean Sea constitutes a unique environment to study cold-seep ecosystems due to the presence of different geodynamic settings, from an active margin along the Mediterranean Ridge (MR) to a passive margin in the Nile Deep-Sea Fan (NDSF). We attempted to identify the structure of benthic communities associated with the Napoli and Amsterdam mud volcanoes (MVs) located on the MR and to establish the links between faunal distribution and environmental conditions at different spatial scales. Comparison between the 2 MVs revealed that the faunal distribution seemed to be mainly controlled by the characteristics of the microhabitats. On both geological structures, the variability between the different microhabitats was higher than the variability observed between replicates of the same microhabitat, and the distribution of macro-fauna was apparently linked to gradients in physico-chemical conditions. The peripheral sites from Napoli were generally more oxygenated and harboured lower species richness than the active sites. The reduced sediment microhabitat from Amsterdam presented the highest methane concentrations and was mainly colonised by symbiont-bearing vesicomyid bivalves and heterotrophic dorvilleid polychaetes. Overall, a higher taxonomic diversity was observed on Napoli. Sub-stratum type was hypothesised to be the second factor influencing faunal distribution. The results of this study highlight the high heterogeneity of faunal communities associated with seep ecosystems within this region and the need to pursue investigations at various spatial and temporal scales.
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International audience
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Dissertação de Mestrado Integrado em Medicina Veterinária
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Este trabajo exploratorio estudia al movimiento político Mesa de la Unidad Democrática (MUD), creada con el fin de oponerse la Gobierno socialista existente en venezuela. La crítica que este documento realiza, parte desde el punto de vista de la Ciencia de la Complejidad. Algunos conceptos clave de sistemas complejos han sido utilizados para explicar el funcionamiento y organización de la MUD, esto con el objetivo de generar un diagnóstico integral de los problemas que enfrenta, y evidenciar las nuevas percepciones sobre comportamientos perjudiciales que el partido tiene actualmente. Con el enfoque de la complejidad se pretende ayudar a comprender mejor el contexto que enmarca al partido y, para, finalmente aportar una serie de soluciones a los problemas de cohesión que presen
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This thesis has the aim to give an overview about the tectonic history of the Epiligurian units, which crop out in the axial portion of the Northern Apennines fold-and-thrust belt, from a structural and thermal point of view, through a multiscalar and multitecnique approach. I focused on a key example of Epiligurian wedge-top basin, (Marzabotto Basin) proceeding from macro-to-microscale approach. The study started from a remote sensing analysis of the lineaments and morphostructures which affected the study area to obtain the regional faulting pattern and an overview about the main tectonic structures, used as basis for the structural investigation at the mesoscale. On the basis of this, it was possible to reconstruct the succession of tectonic events that affected the Marzabotto Basin, consisting in: i) two sets of thrusts indicating a NE-SW and NW-SE shortening of the sedimentary succession; ii) NE-SW-left lateral transtensional faults related to a strike-slip tectonic phase; iii) three main sets of extensional structures which cut and displace the previous thrusts. Normal faults are related to the post-orogenic evolution and have been dated with U-Th method, getting an age of Middle-Late Pleistocene. From a thermal point of view, apatite fission-tracks and (U-Th)/He analyses of detrital minerals and thermal modelling on the middle-upper Eocene siliciclastic deposits allowed me to better constrain the local exhumation history and correlate it with the large-scale tectonic evolution of the Northern Apennines. In particular, the Marzabotto Basin experienced a complex burial-exhumation history, consisting in two cooling cooling phases related to the growth of the Northern Apennines belt (Oligo-Miocene in age) and a later cooling which tracks the accretion in the orogenic wedge concomitant with rollback-driven extension (late Miocene-Pliocene in age). In conclusion it is possible to affirm that the study shed new light on poorly constrained elements of fold-and-thrust belt.
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Background. Il recupero funzionale precoce dopo intervento di wedge resection polmonare non è studiato in maniera approfondita, in particolare, sono carenti i dati relativi al recupero postoperatorio precoce dei pazienti sottoposti a tele procedura chirurgica in seguito a metastasi polmonari per tumore osseo primitivo. Obiettivo. Lo scopo di questo studio osservazionale è quello di descrivere il percorso fisioterapico dopo intervento di wedge resection polmonare, evidenziando il possibile recupero funzionale nel breve termine e ricercandone i possibili fattori prognostici. Metodi. Per valutare il recupero funzionale si è utilizzato il 1 minute sit to stand test (1MSTS), che è stato somministrato in sesta giornata postoperatoria. Per descrivere l’andamento del recupero il test è stato somministrato in fase preoperatoria e in tutte le giornate postoperatorie. Sono state condotte analisi di univariata per valutare l’associazione delle variabili demografiche, anamnestiche e cliniche con l’outcome primario. Risultati. Sono stati reclutati 13 pazienti, per un totale di 17 osservazioni poiché alcuni pazienti hanno ripetuto l’operazione. Nella sesta giornata il 41,2% dei pazienti aveva eseguito lo stesso o un numero maggiore di verticalizzazioni del 1MSTS fatte nella fase preoperatoria. Nella sesta giornata postoperatoria il 100% dei pazienti era riuscito ad eseguire il 1MSTS almeno una volta dopo l’intervento. All’outcome primario risultavano associarsi con una significatività statistica il livello di autonomia, misurato con la TESS, (p=0,01) e il 1MSTS (p=0,001) misurati nella fase preoperatoria. Conclusioni. Il recupero funzionale postoperatorio è possibile fin dalle prime giornate postoperatorie per i pazienti sottoposti a wedge resection. Il livello di autonomia e il numero di verticalizzazioni del 1MSTS eseguite in fase preoperatoria sono possibili fattori prognostici del recupero funzionale postoperatorio.
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The presence of vegetal impurities in sugarcane delivered to sugarmills as green and dry leaves is a problem not only because they are non-value materials to be processed along with sugarcane stalks, but also because they can rise the color of the clarified juice and, consequently, the color of the sugar produced, with a reduction of its quality for the market. Another problem is the mud volume sedimented in the clarifiers, which also can result in a larger recirculation and greater volume of filtrate juice, with higher losses of sucrose and utilization of the vacuum rotary filters. The objective of this work was to observe the effect of the presence of green and dry leaves on sugarcane juice clarification, related to a control treatment with the addition of fiber extracted from the stalks. The experiments were planned based on the addition of quantities of fibrous sources in order to formulate samples with absolute increase of 0.25 , 0.50 and 0.75 percentual points over the fiber content of the sugarcane stalks (control treatment). The juice clarification was conducted with a laboratory clarifier. The clarified juice color and the mud volume were evaluated. The presence of green leaves caused higher color and mud volume due to the extraction of non-sucrose components of the leaves. Soluble compounds of dry leaves were also extracted, though not detected by juice analysis. The addition of the fiber extracted from the stalks did not induce alterations in the clarification process.
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This study describes the sperm morphology of the mayfly Hexagenia (Pseudeatonica) albivitta (Ephemeroptera). Its spermatozoon measures approximately 30 μm of which 9 μm corresponds to the head. The head is composed of an approximately round acrosomal vesicle and a cylindrical nucleus. The nucleus has two concavities, one in the anterior tip, where the acrosomal vesicle is inserted and a deeper one at its base, where the flagellum components are inserted. The flagellum is composed of an axoneme, a mitochondrion and a dense rod adjacent to the mitochondrion. A centriolar adjunct is also observed surrounding the axoneme in the initial portion of the flagellum and extends along the flagellum for at least 2 μm, surrounding the axoneme in a half-moon shape. The axoneme is the longest component of the flagellum, and it follows the 9+9+0 pattern, with no central pair of microtubules. At the posterior region of the flagellum, the mitochondrion has a dumb-bell shape in cross sections that, together with the rectangular mitochondrial-associated rod, is responsible for the flattened shape of the flagellum. An internal membrane is observed surrounding both mitochondrion and its associated structure.