26,408 research outputs found

    Low cost anti-galling bushings

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    Heat shrinkable Teflon tubing is cut to size, slipped onto shaft, heated to shrink tightly to shaft, or machined to final outside diameter size. Shaft bushings fabricated from shrinkable Teflon tubing provide economic close fitting sleeves that prevent galling and contamination in valves

    The impact of fruit flavonoids on memory and cognition

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    There is intense interest in the studies related to the potential of phytochemical-rich foods to prevent age-related neurodegeneration and cognitive decline. Recent evidence has indicated that a group of plant-derived compounds known as flavonoids may exert particularly powerful actions on mammalian cognition and may reverse age-related declines in memory and learning. In particular, evidence suggests that foods rich in three specific flavonoid sub-groups, the flavanols, anthocyanins and/or flavanones, possess the greatest potential to act on the cognitive processes. This review will highlight the evidence for the actions of such flavonoids, found most commonly in fruits, such as apples, berries and citrus, on cognitive behaviour and the underlying cellular architecture. Although the precise mechanisms by which these flavonoids act within the brain remain unresolved, the present review focuses on their ability to protect vulnerable neurons and enhance the function of existing neuronal structures, two processes known to be influenced by flavonoids and also known to underpin neuro-cognitive function. Most notably, we discuss their selective interactions with protein kinase and lipid kinase signalling cascades (i.e. phosphoinositide-3 kinase/Akt and mitogen-activated protein kinase pathways), which regulate transcription factors and gene expression involved in both synaptic plasticity and cerebrovascular blood flow. Overall, the review attempts to provide an initial insight into the potential impact of regular flavonoid-rich fruit consumption on normal or abnormal deteriorations in cognitive performance

    Possible role of crustal flexure in the initial detachment of extensional allochthons

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    The existence of low-angle normal faults indicates that the ratio of shear stress (TAU) to normal stress (sigma sub N) needed to cause slip on faults is substantially less than would be predicted based on experimental data. Because the tensional strength of rock at a large scale is exceedingly low, the upper plate of a low-angle normal fault cannot be pulled down the fault ramp, but must be driven down it by its own weight. The active or recently active Sevier Desert detachment fault in western Utah dips regionally at 12 deg. The radio of shear stress to normal stress due to the weight of the upper plate on a 12 deg dipping fault surface is 0.2. In contrast, laboratory experiments indicate that slip on fracture surfaces occurs with almost all rock types when (tau/sigma) reaches values of 0.6 to 0.85, corresponding to normal-fault dips of 30 deg to 40 deg. Seismological data indicate that low deviatoric stresses are associated with movement on faults of other geometrics and are not unique to low-angle normal faults. It thus appears that approximately planar fault zones with surface areas of hundreds to thousands of square kilometers have different mechanical properties than would be predicted based on laboratory studies of fractured rock. Modeling of stresses indicates that deviatoric stresses greater than 5kb exist and are sustainable in oceanic lithosphere, and that failure occurs when tau/sigma sub N approaches 0.6 to 0.85

    Champagne Seas—Foretelling the Ocean’s Future?

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    Research policy and practice - commitment, complexity and uncertainty: a case study of a government research council funded project, engineering the future

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    Evidence based policy formation, both at EU and national level, built upon close linkage of research, policy and practice is regarded by many as an optimum solution. However, while there are many examples in European education of any two of these communities collaborating in development, the realisation of meaningful inter-relationships among all three communities is complex (Ball 1997). Evidence is often contested, while policy is determined not only by explicit political philosophies but also by deeply embedded assumptions. This paper examines this complexity through the lens of a case study in one country, Scotland, which illuminates relationships among the policy, research and practitioner communities at national and local levels and the nature of their contributions to national curriculum development. The paper explores potential tensions between the development of participative ways of working and the existing structures and ways of thinking within an education system, and examines limitations on what can be effected within existing governance systems. Since 1999 the Scottish Parliament sets the legal framework for education in Scotland; within this the Scottish government has full responsibility for education policy and provision. Following the outcomes of a government initiated National Debate on the purposes and practices of school education, Scotland?s school system has for the last six years been the locus of an extensive and radical development programme in curriculum, assessment and pedagogy (Curriculum for Excellence)

    Loyalty and longevity in audience listening: investigating experiences of attendance at a chamber music festival

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    There is currently much concern amongst arts organisations and their marketing departments that audiences for classical music are in decline, yet little research has so far investigated the experiences of long-term listeners for insight on audience development and retention. This paper presents a case study of the Music in the Round chamber music festival, conducted over a three year period which included the retirement of the host string quartet, the appointment of a new resident ensemble, and associated changes in audience attitudes and priorities. The interaction between individual listening and collective membership of an audience is discussed, and the potential considered for understanding classical concert-goers as ‘fans’ or ‘consumers’

    Ultrasonic scanner for radial and flat panels

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    An ultrasonic scanning mechanism is described that scans panels of honeycomb construction or with welded seams. It incorporates a device which by simple adjustment is adapted to scan either a flat panel or a radial panel. The supporting structure takes the form of a pair of spaced rails. An immersion tank is positioned between the rails and below their level. A work holder is mounted in the tank and is adapted to hold the flat or radial panel. A traveling bridge is movable along the rails and a carriage is mounted on the bridge

    Managing rapport in intercultural business interactions: a comparison of two Chinese-British welcome meetings

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    This paper explores the management of rapport in intercultural business interactions. It compares two Chinese-British business welcome meetings that were held by the same British company. Despite many similarities between the two meetings, both the British and the Chinese were very satisfied with the first meeting, while the Chinese were very annoyed by the second. This paper describes the similarities and differences between the two meetings, and explores why they were evaluated so differently. It argues that research into the management of relations in intercultural communication needs to use a broader analytic framework than is typical of intercultural discourse research, and that it needs to gather a wider range of data types

    Real-time growth rate for general stochastic SIR epidemics on unclustered networks

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    Networks have become an important tool for infectious disease epidemiology. Most previous theoretical studies of transmission network models have either considered simple Markovian dynamics at the individual level, or have focused on the invasion threshold and final outcome of the epidemic. Here, we provide a general theory for early real-time behaviour of epidemics on large configuration model networks (i.e. static and locally unclustered), in particular focusing on the computation of the Malthusian parameter that describes the early exponential epidemic growth. Analytical, numerical and Monte-Carlo methods under a wide variety of Markovian and non-Markovian assumptions about the infectivity profile are presented. Numerous examples provide explicit quantification of the impact of the network structure on the temporal dynamics of the spread of infection and provide a benchmark for validating results of large scale simulations.Comment: 45 pages, 8 figures, submitted to Mathematical Biosciences on 29/11/2014; Version 2: resubmitted on 15/04/2015; accepted on 17/04/2015. Changes: better explanations in introduction; restructured section 3.3 (3.3.3 added); section 6.3.1 added; more precise terminology; typos correcte
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