2,722 research outputs found

    Consideration of the listener in the assessment and treatment of dysarthria

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    Traditionally, speech production deficits have been the focus of clinical practice and research in dysarthria. However, recent research has begun to examine the role of the listener in communication interaction. This article provides an overview of perceptual processing theory relevant to dysarthria. In addition, it discusses the relationship of current theoretical models of speech perception to the assessment and treatment of dysarthria. Finally, it provides insight into how this information may inform current clinical practices and future research in the field

    Alterations in the self-renewal and differentiation ability of bone marrow mesenchymal stem cells in a mouse model of rheumatoid arthritis

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    Introduction: Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease primarily involving the synovium. Evidence in recent years has suggested that the bone marrow (BM) may be involved, and may even be the initiating site of the disease. Abnormalities in haemopoietic stem cells' (HSC) survival, proliferation and aging have been described in patients affected by RA and ascribed to abnormal support by the BM microenvironment. Mesenchymal stem cells (MSC) and their progeny constitute important components of the BM niche. In this study we test the hypothesis that the onset of inflammatory arthritis is associated with altered self-renewal and differentiation of bone marrow MSC, which alters the composition of the BM microenvironment. Methods: We have used Balb/C Interleukin-1 receptor antagonist knock-out mice, which spontaneously develop RA-like disease in 100% of mice by 20 weeks of age to determine the number of mesenchymal progenitors and their differentiated progeny before, at the start and with progression of the disease. Results: We showed a decrease in the number of mesenchymal progenitors with adipogenic potential and decreased bone marrow adipogenesis before disease onset. This is associated with a decrease in osteoclastogenesis. Moreover, at the onset of disease a significant increase in all mesenchymal progenitors is observed together with a block in their differentiation to osteoblasts. This is associated with accelerated bone loss. Conclusions: Significant changes occur in the BM niche with the establishment and progression of RA-like disease. Those changes may be responsible for aspects of the disease, including the advance of osteoporosis. An understanding of the molecular mechanisms leading to those changes may lead to new strategies for therapeutic intervention

    Portland Stone: a nomination for "Global Heritage Stone Resource" from the United Kingdom

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    Portland Stone, a well known ooidal limestone of Jurassic age from the United Kingdom is here nominated as a suitable "Global Heritage Stone Resource". Portland Stone is considered to ideally fit the newly proposed designation as it has been utilised since Roman times in England and since the Middle Ages in the construction of major historic buildings including St Pauls Cathedral, British Museum and Bank of England in London. It was also the preferred building stone of Sir Christopher Wren, England's most famous architect. The international use of Portland Stone during the 20th century includes the United Nations building in New York City and the war graves of British and British Commonwealth soldiers. Portland Stone also continues to be quarried today in an environmentally sensitive manner whilst coastal outcrops of the material form a part of the "Dorset and East Devon Coast" World Heritage area (aka The Jurassic Heritage Coast)

    Microstructural characterisation of TiAlTiAu and TiAlPdAu ohmic contacts to AlGaN/GaN

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    Ti/Al/Ti/Au and Ti/Al/Pd/Au contacts to AlGaN/GaN have been investigated to ascertain the effect of annealing temperature on the structural evolution of the contacts. Ti/Al/Ti/Au contacts become ohmic after rapid thermal annealing at 750Ā°C or higher, corresponding to the formation of an interfacial TiN phase, with inclusions penetrating through the AlGaN layer observed after annealing at 950Ā°C. The Pd layer is shown to be more efficient at inhibiting diffusion of Au to the interface than Ti. Ohmic behaviour was not seen with the Ti/Al/Pd/Au scheme. Either the presence of Au at the interface may improve ohmic behaviour, or the Ti:Al ratio is insufficient in this scheme

    String and Fivebrane Solitons: Singular or Non-singular?

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    We ask whether the recently discovered superstring and superfivebrane solutions of D=10 supergravity admit the interpretation of non-singular solitons even though, in the absence of Yang-Mills fields, they exhibit curvature singularities at the origin. We answer the question using a test probe/source approach, and find that the nature of the singularity is probe-dependent. If the test probe and source are both superstrings or both superfivebranes, one falls into the other in a finite proper time and the singularity is real, whereas if one is a superstring and the other a superfivebrane it takes an infinite proper time (the force is repulsive!) and the singularity is harmless. Black strings and fivebranes, on the other hand, always display real singularities.Comment: 15 page

    Bimodal granulocyte transit time through the human lung demonstrated by deconvolution analysis

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    AbstractThe lungs are an important site of granulocyte pooling. The aim of the study is to quantify pulmonary vascular granulocyte transit time using deconvolution analysis, as has previously been performed to measure pulmonary red cell transit time. Granulocyte and red cell studies were performed in separate groups of patients. Both cell types were labelled with Tc-99m, which for granulocyte labelling was complexed with hexamethylpropyleneamine oxime (HMPAO). The red cell impulse response function (IRF) was monoexponential with a median transit time of 4Ā·3 s. The granulocyte IRF was biexponential in 19 of 22 subjects, 18 of whom had systemic inflammation (inflammatory bowel disease, systemic vasculitis or graft-vs-host disease) and four were controls without inflammatory disease. The median transit time of the fast component ranged from 20 to 25 s and of the slow component 120ā€“138 s in the four patient groups. The fraction of cells undergoing slow transit correlated significantly with (a) mean granulocyte transit time and (b) the fraction showing shape change in vitro. We conclude that granulocyte transit time through the pulmonary circulation is bimodal and that shape-changed (activated) cells transit more slowly that non-activated cells. The size of the fraction undergoing slow transit is closely related to mean granulocyte transit time and is an important determinant of the size of the pulmonary vascular granulocyte pool

    Pedestrian flows in bounded domains with obstacles

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    In this paper we systematically apply the mathematical structures by time-evolving measures developed in a previous work to the macroscopic modeling of pedestrian flows. We propose a discrete-time Eulerian model, in which the space occupancy by pedestrians is described via a sequence of Radon positive measures generated by a push-forward recursive relation. We assume that two fundamental aspects of pedestrian behavior rule the dynamics of the system: On the one hand, the will to reach specific targets, which determines the main direction of motion of the walkers; on the other hand, the tendency to avoid crowding, which introduces interactions among the individuals. The resulting model is able to reproduce several experimental evidences of pedestrian flows pointed out in the specialized literature, being at the same time much easier to handle, from both the analytical and the numerical point of view, than other models relying on nonlinear hyperbolic conservation laws. This makes it suitable to address two-dimensional applications of practical interest, chiefly the motion of pedestrians in complex domains scattered with obstacles.Comment: 25 pages, 9 figure

    Digitising the Turing Archive: A Pilot Study

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    This report presents a summary of the pilot project to produce an on-line version of a selected portion of the archive of Alan Turing held at Kingā€™s College, Cambridge. The design and creation of a database making use of information held in the archive catalogue is discussed. The production of a Web based interface to access the on-line materials is described. The practical issues involved in digitising documents are covered and the lessons learnt from this process are included. Finally, the report also presents an effort model, and sample timings from which cost estimates can be obtained
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