5,670 research outputs found

    Cavitation analysis of a double acting podded drive during ice milling

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    Propeller ice interaction is a complex phenomenon, which relies on innovative and complex experimental research in dedicated ice tank facilities. Whilst the ice tanks model the contact forces with good agreement, the hydrodynamic loading is often only assumed due to the inability to scale atmospheric pressure during these experiments. A small amount of research is however being conducted in cavitation tunnels using innovative methods to represent full scale ice milling conditions. Propulsor ice interaction tests in a cavitation tunnel are therefore both novel and uncommon due to their complexity. The Emerson Cavitation Tunnel at the University of Newcastle (ECT) has pioneered a series of ice milling tests within a cavitation tunnel using model ice. These ice milling tests allow an ice propulsor to experience correctly scaled cavitation numbers as a propeller interacts with ice. In all of the conditions tested, the current research observed presence and influence of cavitation and showed it to be a significant factor, something that is missing from standard ice tank tests. The work published in this paper forms part of a PhD research into the topic by the principal author [1].http://deepblue.lib.umich.edu/bitstream/2027.42/84309/1/CAV2009-final135.pd

    A role for TSPO in mitochondrial Ca2+ homeostasis and redox stress signaling

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    The 18 kDa translocator protein TSPO localizes on the outer mitochondrial membrane (OMM). Systematically overexpressed at sites of neuroinflammation it is adopted as a biomarker of brain conditions. TSPO inhibits the autophagic removal of mitochondria by limiting PARK2-mediated mitochondrial ubiquitination via a peri-organelle accumulation of reactive oxygen species (ROS). Here we describe that TSPO deregulates mitochondrial Ca2+ signaling leading to a parallel increase in the cytosolic Ca2+ pools that activate the Ca2+-dependent NADPH oxidase (NOX) thereby increasing ROS. The inhibition of mitochondrial Ca2+ uptake by TSPO is a consequence of the phosphorylation of the voltage-dependent anion channel (VDAC1) by the protein kinase A (PKA), which is recruited to the mitochondria, in complex with the Acyl-CoA binding domain containing 3 (ACBD3). Notably, the neurotransmitter glutamate, which contributes neuronal toxicity in age-dependent conditions, triggers this TSPO-dependent mechanism of cell signaling leading to cellular demise. TSPO is therefore proposed as a novel OMM-based pathway to control intracellular Ca2+ dynamics and redox transients in neuronal cytotoxicity

    Cholesterol and coronary heart disease: screening and treatment

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    Coronary heart disease (CHD) is a major cause of morbidity and mortality in the United Kingdom, accounting for just under one quarter of all deaths in 1995: 27% among men and 21% among women.1 Although many CHD deaths occur among elderly people, CHD accounts for 31% of male and 13% of female deaths within the 45–64 age group

    Precautionary labelling of foods for allergen content: are we ready for a global framework?

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    © 2014 Allen et al.; licensee BioMed Central Ltd.Food allergy appears to be on the rise with the current mainstay of treatment centred on allergen avoidance. Mandatory allergen labelling has improved the safety of food for allergic consumers. However an additional form of voluntary labelling (termed precautionary allergen labelling) has evolved on a wide range of packaged goods, in a bid by manufacturers to minimise risk to customers, and the negative impact on business that might result from exposure to trace amounts of food allergen present during cross-contamination during production. This has resulted in near ubiquitous utilisation of a multitude of different precautionary allergen labels with subsequent confusion amongst many consumers as to their significance. The global nature of food production and manufacturing makes harmonisation of allergen labelling regulations across the world a matter of increasing importance. Addressing inconsistencies across countries with regards to labelling legislation, as well as improvement or even banning of precautionary allergy labelling are both likely to be significant steps forward in improved food safety for allergic families. This article outlines the current status of allergen labelling legislation around the world and reviews the value of current existing precautionary allergen labelling for the allergic consumer. We strongly urge for an international framework to be considered to help roadmap a solution to the weaknesses of the current systems, and discuss the role of legislation in facilitating this

    Addressing Food Insecurity in College: Mapping a Shared Conceptual Framework for Campus Pantries in Michigan

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    The first known university food pantry started at Michigan State University in 1993. Since then, campus food pantries are more widespread, although little is known about them. The current study examined how college pantries best serve students and foster their success. Twentyâ eight food pantry directors and staff from across sixteen Michigan college campuses engaged in concept mapping, a technique used to examine the interrelationships among concepts understood by stakeholders. Analyses identified six concepts, examined importance of each concept as assigned by participants, and evaluated variation among institutions. Implications for findings and future research directions are discussed.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147046/1/asap12161_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147046/2/asap12161.pd

    Stability Measurements of Rutherford Cables with Various Treatments

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    To improve the stability of Rutherford type superconducting cables, various methods of treating cables were considered and tested. These treatments include strand coating, partial soldering, "barber-pole" insulation and "porous 9metal"solderfilling.Tostudytheeffectofthesetreatments,severalcableswerepreparedandMQE(minimumquenchenergy)valuesweremeasured.Coating,partialsolderingor"barberpoleinsulation"improvedtherelativestability9 metal" solder filling. To study the effect of these treatments, several cables were prepared and MQE (minimum quench energy) values were measured. Coating, partial soldering or "barber-pole insulation" improved the relative stability 9 for some cables. The "porous metal" filled cables showed higher MQE. However the results suggest that the porous metal process needs to be improved. The measured data for cables with various treatments are presented. (8 refs)

    Generic bounds on dipolar gravitational radiation from inspiralling compact binaries

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    Various alternative theories of gravity predict dipolar gravitational radiation in addition to quadrupolar radiation. We show that gravitational wave (GW) observations of inspiralling compact binaries can put interesting constraints on the strengths of the dipole modes of GW polarizations. We put forward a physically motivated gravitational waveform for dipole modes, in the Fourier domain, in terms of two parameters: one which captures the relative amplitude of the dipole mode with respect to the quadrupole mode (α\alpha) and the other a dipole term in the phase (β\beta). We then use this two parameter representation to discuss typical bounds on their values using GW measurements. We obtain the expected bounds on the amplitude parameter α\alpha and the phase parameter β\beta for Advanced LIGO (AdvLIGO) and Einstein Telescope (ET) noise power spectral densities using Fisher information matrix. AdvLIGO and ET may at best bound α\alpha to an accuracy of 102\sim10^{-2} and 103\sim10^{-3} and β\beta to an accuracy of 105\sim10^{-5} and 106\sim10^{-6} respectively.Comment: Matches with the published versio

    Atomic data from the IRON Project. I. Electron-impact scattering of Fe17+ using <I>R</I>-matrix theory with intermediate coupling

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    We present results for electron-impact excitation of F-like Fe calculated using R-matrix theory where an intermediate-coupling frame transformation (ICFT) is used to obtain level-resolved collision strengths. Two such calculations are performed, the first expands the target using 2s2 2p5, 2s 2p6, 2s2 2p4 3l, 2s 2p5 3l, and 2p6 3l configurations while the second calculation includes the 2s2 2p4 4l, 2s 2p5 4l, and 2p6 4l configurations as well. The effect of the additional structure in the latter calculation on the n=3 resonances is explored and compared with previous calculations. We find strong resonant enhancement of the effective collision strengths to the 2s2 2p4 3s levels. A comparison with a Chandra X-ray observation of Capella shows that the n=4 R-matrix calculation leads to good agreement with observation</p
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