Wall effects on the transportation of a cylindrical particle in power-law fluids

The present work deals with the numerical calculation of the Stokes-type drag undergone by a cylindrical particle perpendicularly to its axis in a power-law fluid. In unbounded medium, as all data are not available yet, we provide a numerical solution for the pseudoplastic fluid. Indeed, the Stokes-type solution exists because the Stokes’ paradox does not take place anymore. We show a high sensitivity of the solution to the confinement, and the appearance of the inertia in the proximity of the Newtonian case, where the Stokes’ paradox takes place. For unbounded medium, avoiding these traps, we show that the drag is zero for Newtonian and dilatant fluids. But in the bounded one, the Stokes-type regime is recovered for Newtonian and dilatant fluids. We give also a physical explanation of this effect which is due to the reduction of the hydrodynamic screen length, for pseudoplastic fluids. Once the solution of the unbounded medium has been obtained, we give a solution for the confined medium numerically and asymptotically. We also highlight the consequence of the confinement and the backflow on the settling velocity of a fiber perpendicularly to its axis in a slit. Using the dynamic mesh technique, we give the actual transportation velocity in a power-law “Poiseuille flow”, versus the confinement parameter and the fluidity index, induced by the hydrodynamic interactions

Applications of MCMC methods on function spaces

In the course of this thesis, several different applications of data assimilation will be looked at. In each case, a rigorous mathematical framework will be constructed, in a Bayesian context, to enable the use of various types of data to infer on various infinite dimensional parameters of the system that has been observed. After careful consideration of the forward problem, well-defined posterior distributions on function space are constructed. Using MCMC methods which are defined on these function spaces themselves, we can construct Markov chains whose invariant measures are the posterior of interest. From this point, we can implement these methods on a computer, having finally discretised the problem. The philosophy that we adhere to throughout, is the idea that numerical methods formulated on function space are robust under discretisation, and do not suffer from the curse of dimensionality typically suffered by sampling methods formulated after disretisation. The first few chapters (after the introductory chapter) will focus on various aspects of data assimilation of observations of Stokes ow dynamics. Chapter 2 will focus on Eulerian data where direct observations of the velocity of the fluid at various points in time and space will be made. Chapter 3 will concentrate on data assimilation of indirect observations of the field, in the form of the positions of passive tracers in the flow. In these two chapters we will assume that the forcing of the system is known and that we are merely trying to recover the initial condition of the flow field. In chapter 4 we will consider both Eulerian and Lagrangian data assimilation, with the added complexity of trying to use the data to not only infer on the initial condition but also on the space-time dependant forcing of the system. In chapter 5 we will try to show how these smoothing methods could be adapted into a filtering algorithm, and a simple example will be presented. In the final chapter, 6, this Bayesian framework on function space will be applied to a shape matching problem with applications in the biomedical sciences.EThOS - Electronic Theses Online ServiceEngineering and Physical Sciences Research Council (EPSRC)GBUnited Kingdo

Small Heat Shock Protein αA-Crystallin Prevents Photoreceptor Degeneration in Experimental Autoimmune Uveitis

The small heat shock protein, αA-crystallin null (αA−/−) mice are known to be more prone to retinal degeneration than the wild type mice in Experimental Autoimmune Uveoretinitis (EAU). In this report we demonstrate that intravenous administration of αA preserves retinal architecture and prevents photoreceptor damage in EAU. Interestingly, only αA and not αB-crystallin (αB), a closely related small heat shock protein works, pointing to molecular specificity in the observed retinal protection. The possible involvement of αA in retinal protection through immune modulation is corroborated by adaptive transfer experiments, (employing αA−/− and wild type mice with EAU as donors and Rag2−/− as the recipient mice), which indicate that αA protects against the autoimmune challenge by modulating the systemic B and T cell immunity. We show that αA administration causes marked reduction in Th1 cytokines (TNF-α, IL-12 and IFN-γ), both in the retina and in the spleen; notably, IL-17 was only reduced in the retina suggesting local intervention. Importantly, expression of Toll-like receptors and their associated adaptors is also inhibited suggesting that αA protection, against photoreceptor loss in EAU, is associated with systemic suppression of both the adaptive and innate immune responses

New mediterranean biodiversity records (November, 2016)

This Collective Article presents information on 26 taxa belonging to 8 Phyla and extending from the western Mediterranean to the Levantine Sea. The new records were found in 9 countries as follows: Spain: first record for the Mediterranean of the crab Cancer bellianus; Algeria: further records of the alien fish Lagocephalus sceleratus in western Algerian waters; Italy: first report on the presence and establishment of the ctenophore Mnemiopsis leidyi in Lessina and Varano Lagoons (W. Adriatic) and of Penaeus aztecus in Corigliano Gulf (Italian Ionian). Moreover, the extension of the distribution range of the polychaete Branchiomma bairdi to W. Sicily as well as that of the crab Ocypode cursor and the bryozoan Catenicella paradoxa to E. Sicily are cited. Slovenia: the record of the rare saccoglossan gastropod Placida cremoniana from Piran (Gulf of Trieste) is the first for the Adriatic; Greece: the native sea slug Eubranchus farrani is the first from the Eastern Mediterranean; many sightings of the bamboo corals Isididae distributed along all the E. Ionian Sea and the establishment of P. aztecus in all Greek waters are also reported for first time; the westernmost extension of the alien urchin Diadema setosum in Cretan waters is cited and new sightings of the alien species Goniobranchus annulatus and Pterois miles are presented. Turkey: the alien fish Champsodon capensis is reported for first time from the Aegean Sea and the native acari Agauopsis microrhyncha from the Levantine Sea; a new observation of the alien crab Atergatis roseus in Güllük Bay-Aegean is also mentioned; Cyprus: first records of the alien urchin D. setosum and Lobotes surinamensis in Cypriot waters; Lebanon: several sightings of Monachus monachus from Lebanese waters indicate a potential better status for the species in the area; Egypt: first records of the alien crab Dorippe quadridens and the alien gastropods Nerita sanguinolenta and Conomurex persicus from the Mediterranean Egyptian waters; extension of the distribution range of Diodora funiculata and Diodora rueppellii and a second record of the alien Fulvia fragilis in the same area

Il trattamento chirurgico degli sventramenti spontanei: tecnica originale di protesizzazione della parete addominale

Gli Autori si soffermano sulla correzione chirurgica degli sventramenti spontanei e ne puntualizzano le indicazioni e gli obiettivi. Precisate le possibilità e definiti i limiti delle metodiche chirurgiche tradizionali dell’affezione, discutono sul razionale di un’innovativa e originale tecnica di protesizzazione della parete anteriore dell’addome, messa a punto per la cura degli importanti divari fra i due retti e frutto di una sorta di eclettismo e di integrazione di alcune fasi operatorie del procedimento di autoplastica di Quénu e della tecnica di Welti-Eudel e Chevrel. Descrivono, quindi, la sequenza dei tempi operatori della metodica ideata e presentano la preliminare esperienza clinica maturata con la stessa, i cui risultati definiscono lusinghieri e incoraggianti riguardo all’efficacia curativa (in senso cosmetico e funzionale) immediata e duratura, alla sicurezza e alla compliance del paziente. Gli Autori ritengono di potere sostenere, alla luce dei risultati ottenuti, l’indubbia affidabilità della protesizzazione della parete addominale nel trattamento dei grandi sventramenti spontanei e si prefiggono di esprimere sulla metodica un definitivo giudizio dopo ulteriori esperienze cliniche su casistiche più ampi

L’emangioma capillare dello stomaco: una rara fonte di sanguinamento. Caso clinico

Gastric haemorrhages are common clinical emergencies which often directly involve the surgeon in diagnosis and treatment; among these, rare vascular neoplasms deserve particular attention. The Authors report a rare case of benign vascular tumour of the stomach, a capillary angioma. After a literature review they highlight the importance of specific exams to reveal these small neoformations which, generally, show up clinically with acute bleeding, which may be severe, and which may not be discovered if the clinical evaluation is not very detailed. The surgical excision supported by a frozen sections is the most effective treatmen