56 resultados para 12056


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Marine organic matter (OM) sinks from surface waters to the seafloor via the biological pump. Benthic communities, which use this sedimented OM as energy and carbon source, produce dissolved organic matter (DOM) in the process of remineralization, enriching the sediment porewater with fresh DOM compounds. We hypothesized that in the oligotrophic deep Arctic basin the molecular signal of freshly deposited primary produced OM is restricted to the surface sediment pore waters which should differ from bottom water and deeper sediment pore water in DOM composition. This study focused on: 1) the molecular composition of the DOM in sediment pore waters of the deep Eurasian Arctic basins, 2) whether the signal of marine vs. terrigenous DOM is represented by different compounds preserved in the sediment pore waters and 3) whether there is any relation between Arctic Ocean ice cover and DOM composition. Molecular data, obtained via 15 Tesla Fourier transform ion cyclotron resonance mass spectrometer, were correlated with environmental parameters by partial least square analysis. The fresher marine detrital OM signal from surface waters was limited to pore waters from < 5 cm sediment depth. The productive ice margin stations showed higher abundances of peptides, unsaturated aliphatics and saturated fatty acids formulae, indicative of fresh OM/pigments deposition, compared to northernmost stations which had stronger aromatic signals. This study contributes to the understanding of the coupling between the Arctic Ocean productivity and its depositional regime, and how it will be altered in response to sea ice retreat and increasing river runoff.

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Mode of access: Internet.

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We have simulated the performance of various apertures used in Coded Aperture Imaging - optically. Coded pictures of extended and continuous-tone planar objects from the Annulus, Twin Annulus, Fresnel Zone Plate and the Uniformly Redundant Array have been decoded using a noncoherent correlation process. We have compared the tomographic capabilities of the Twin Annulus with the Uniformly Redundant Arrays based on quadratic residues and m-sequences. We discuss the ways of reducing the 'd. c.' background of the various apertures used. The non-ideal System-Point-Spread-Function inherent in a noncoherent optical correlation process produces artifacts in the reconstruction. Artifacts are also introduced as a result of unwanted cross-correlation terms from out-of-focus planes. We find that the URN based on m-sequences exhibits good spatial resolution and out-of-focus behaviour when imaging extended objects.

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Rural residents of NL face some of the most complex and challenging mental health issues including depression, schizophrenia, and risk of suicide with inadequate and hard to access treatment services. Due to the increasing demands for mental health services, government officials have been emphasizing the need for more responsive and person-centered services to meet client needs. Time-sensitive counselling, an alternative approach to long-term counselling, provides more timely and focused interventions. Mental Health services in Bonavista, a rural community in NL, recently began offering time-sensitive counselling services to its residents, entitled the “Change Clinic.” This phenomenological qualitative research study explored individuals’ experiences of time-sensitive counselling services as offered by mental health services in Bonavista. The results of this research study are detailed and suggest that time-sensitive counselling services can assist in meeting the service needs of rural residents of NL.

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Rezension von: Alex Aßmann / Jens Oliver Krüger (Hrsg.): Ironie in der Pädagogik. Theoretische und empirische Studien zur pädagogischen Bedeutsamkeit der Ironie. Weinheim: Juventa 2011 (224 S.; ISBN 978-3-7799-2242-1)

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Dissertação para obtenção do grau de Mestre em Arquitectura, apresentada na Universidade de Lisboa - Faculdade de Arquitetura.

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London, Wellcome Library, MS 411 is a codex in one volume which dates from the late fifteenth century. It houses a collection of practical treatises and tracts in English and Latin, in verse as well as in prose, on different topics including prognostications, nativities, medical astrology, reproduction, toxicology, bloodletting, etc. In this paper, the Middle English anonymous treatise on venomous bites, written in prose and held in folios 56r to 61r, is taken into consideration. The objective is twofold: on the one hand, to examine the contents, transmission and sources of the text and, on the other, to describe it from a physical standpoint. Investigation on those aspects of the treatise contained in Wellcome MS 411 can shed some light on the function and diffusion of the text, and may also prove significant for a better understanding of it.

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Il presente lavoro prende le mosse da un problema di dinamica dei fasci relativo a un metodo di separazione di un fascio di particelle recentemente messo in funzione nell’sincrotrone PS al CERN. In questo sistema, variando adiabaticamente i parametri di un campo magnetico, nello spazio delle fasi si creano diverse isole di stabilità (risonanze) in cui le particelle vengono catturate. Dopo una parte introduttiva in cui si ricava, a partire dalle equazioni di Maxwell, l’hamiltoniana di una particella sottoposta ai campi magnetici che si usano negli acceleratori, e una presentazione generale della teoria dell’invarianza adiabatica, si procede analizzando la dinamica di tali sistemi. Inizialmente si prende in considerazione l’hamiltoniana mediata sulle variabili veloci, considerando perturbazioni (kick) dei termini dipolare e quadrupolare. In ognuno dei due casi, si arriva a determinare la probabilità che una particella sia catturata nella risonanza. Successivamente, attraverso un approccio perturbativo, utilizzando le variabili di azione ed angolo, si calcola la forza della risonanza 4:1 per un kick quadrupolare.

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"El conflicto es una expresión de la heterogeneidad de las colectividades humanas. En tanto que manifestación natural de las comunidades, debe ser entendido como una de las formas que asume la diversidad y complejidad de una sociedad con múltiples intereses, expectativas, demandas y problemas de los distintos grupos que la conforman.1 Siguiendo a Bajoit, podemos afirmar que “el conflicto evidencia la desigualdad de que son víctimas ciertos miembros de la sociedad, y que resultan de sus intercambios con otra categoría social, definida como adversaria. Esta evidencia de la desigualdad no lleva, sin embargo, a excluir al adversario ni a suprimir la relación: ella apunta por el contrario a mejorarla, a hacerla más soportable, a redefinirla sobre nuevas bases. Recíprocamente, la categoría social adversaria, que se beneficia de la desigualdad, no puede o no desea optar por una estrategia de exclusión y se ve obligada a entrar en un intercambio conflictual.”"