2,176 research outputs found

    Non-Fickian Diffusion Affects the Relation between the Salinity and Hydrate Capacity Profiles in Marine Sediments

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    On-site measurements of water salinity (which can be directly evaluated from the electrical conductivity) in deep-sea sediments is technically the primary source of indirect information on the capacity of the marine deposits of methane hydrates. We show the relation between the salinity (chlorinity) profile and the hydrate volume in pores to be significantly affected by non-Fickian contributions to the diffusion flux---the thermal diffusion and the gravitational segregation---which have been previously ignored in the literature on the subject and the analysis of surveys data. We provide amended relations and utilize them for an analysis of field measurements for a real hydrate deposit.Comment: 7 pages, 2 figures, 1 table, submitted to Compte Rendus Mecaniqu

    Accounting\u27s uses in exploitative human engineering: Theorizing citizenship, indirect rule and Britain\u27s imperial expansion

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    This historical study starts from the argument that financial economic quantification using accounting concepts and analysis has always been an essential and integral part of effective policies and activities for Britain\u27s empire building. Theories of citizenship are used in particular to examine the close association between accounting and imperial policies during British indirect rule in Fiji. Through an examination of archival data and other relevant source materials, the paper highlights the ways in which accounting helped translate imperial forms of oppression and injustice into everyday work practice. Indirect rule generally required the separation and subordination of the native population as subjects, and their exploitation within imperial hegemonic structures. This research is about a British regime of specific and deliberate power construct through which the indigenous population of subjects were oppressed and excluded from citizenship and from civil society. Focus is on the social, economic and institutional relations that determined a unique pattern of inequality and the way in which accounting was effectively mobilized to serve the aims of British imperialism through indirect rule

    It\u27s okay, I\u27m a...teacher. Is professional status important to teachers?

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    Teacher accountability and the debate around teacher quality are issues of international importance. As society places increasing demands on the teaching profession, and regulatory bodies around the globe raise the ‘standards’ for teachers to adhere to, the professional status of teachers is drawn into focus. This paper reports research findings of an investigation into the perspectives of professional status of teachers, held by pre-service teachers about to embark on their teaching career. This was a comparative study whereby data were collected from an Australian university and an American university to explore professional status as an international issue. This quantitative study utilised a Likert scale to gather responses from participants. Data were analysed and findings from both universities indicated that professional status was a significant concern for pre-service teachers. Pre-service teachers felt that whilst they may have entered their teaching degree as a vocation, they hoped to receive status, as a professional, within society

    Aspirin inhibits the acute venodilator response to furosemide in patients with chronic heart failure

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    OBJECTIVES: We sought to determine the effect of aspirin on the venodilator effect of furosemide in patients with chronic heart failure (CHF) BACKGROUND: Furosemide has an acute venodilator effect preceding its diuretic action, which is blocked by nonsteroidal anti-inflammatory drugs. The ability of therapeutic doses of aspirin to block this effect of furosemide in patients with CHF has not been studied. For comparison, the venodilator response to nitroglycerin (NTG) was also studied. METHODS: Eleven patients with CHF were randomized to receive placebo, aspirin at 75 mg/day or aspirin at 300 mg/day for 14 days in a double-blind, crossover study. The effect of these pretreatments on the change in forearm venous capacitance (FVC) after 20 mg of intravenous furosemide was measured over 20 min by using venous occlusion plethysmography. In a second study, the effect of 400 ÎŒg of sublingual NTG on FVC was documented in 11 similar patients (nine participated in the first study). RESULTS: Mean arterial pressure, heart rate and forearm blood flow did not change in response to furosemide. After placebo pretreatment, furosemide caused an increase in FVC of 2.2% (95% confidence interval [CI] −0.9% to 5.2%; mean response over 20 min). By comparison, FVC fell by −1.1% (95% CI −4.2% to 1.9%) after pretreatment with aspirin at 75 mg/day, and by −3.7% (95% CI −6.8% to −0.7%) after aspirin at 300 mg/day (p = 0.020). In the second study, NTG increased FVC by 2.1% (95% CI −1.6% to 5.8%) (p = 0.95 vs. furosemide). CONCLUSIONS: In patients with CHF, venodilation occurs within minutes of the administration of intravenous dose of furosemide. Our observation that aspirin inhibits this effect further questions the use of aspirin in patients with CHF

    CROSS-EDUCATION EFFECT OBSERVED IN VOLUIUTARY AND ELECTROMYOSTIMULATION STRENGTH TRAINING

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    This study investigated the effects of four weeks of unilateral electromyostimulation(EMS) versus isometric strength training(lM), on knee extension strength of contralateral limb in previously untrained young adults. Subjects performed (IM, n=10) or evoked (EMS, n=10) 40 isometric knee extensions, at an intensity of 65% of maximum voluntary contraction (MVC) force, three times per week, for four weeks. Pre and post training, both legs were tested for maximum voluntary strength on an isokinetic dynamometer, at 0 degls (isometric), 60 and 180 degls velocities. The results showed that the EMS and IM training had a similar effect in strength improvement in these subjects. Both types of training induced significant cross-education effect on isometric MVC of the untrained limb, but not in isokinetic torque. The mechanisms underlying this phenomenon require further study

    The drivers and dynamics of fisher behaviour in Irish fisheries

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    Supervised by Dr Colm Lordan & Dr Rick Officer. Submitted to the Higher Education and Training Awards Council, July 2013It is widely acknowledged within the scientific community that a single species approach to European mixed fisheries can result in species-specific advice inconsistent with multi-species management objectives. Within the reformed Common Fisheries Policy a move toward mixed fisheries and ecosystem based management is encouraged. The overall objective of this research was to improve understanding of the complex targeting behaviour undertaken by commercial fishers. Whereby, improved understanding will enhance the ability to predict the responses to future mixed fisheries management measures and changing economic conditions within the Irish fishing industry. Irish métiers (groups of homogeneous fishing trips) highlight the complexity of fishing activities within the Irish fleet, having identified 33 otter trawl métiers and 19 in the remainder of the fleet. Métier dynamics identified over compensation to introduced management, resulting in effort displacement and increased temporal specific fishing pressure. Therefore were deemed as appropriate base units for all subsequent analyses. Two economic variables, operational fishing cost and trip landings value, considered to represent important drivers were developed. This lead to application of a general additive model to estimate and predict fuel consumption estimates according to fleet segment definitions. A linear mixed effects model with random vessel effect was developed as a method of standardising value generating an index of value per unit effort. This identified kilowatt fishing days as the most appropriate effort measure. The final investigation stage successfully amalgamated the knowledge gained into the formulation of novel Markov transition probability for a multinomial model to predict fisher métier strategy choice. This is to be incorporated into management strategy evaluation, aiding the assessment and possible impacts of future management proposals on the Irish fleet and commercial stocks around Ireland. Developments presented will benefit the progression toward optimising sustainability within a mixed fisheries approach to management through incorporation of economic considerations

    A Formal, Hierarchical Design and Validation Methodology for VLSI

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    The high cost of fabricating VLSI circuits requires that they be validated, that is, shown to function correctly, before manufacture. The cost of design errors can be kept to a minimum if such validation occurs as early as possible; this is achieved by integrating validation into a hierarchical design procedure. In this thesis, a hierarchical approach to design, in which validation is performed between each pair of adjacent levels in the hierarchy, is developed. In order to adopt such an approach, a language is required for the formal description of hardware behaviour and structure. Therefore an important aspect of the development of the methodology, and a major theme of the thesis, is the development of languages to support the methodology. An enhanced version of CIRCAL, which enables large and abstract devices to be described concisely and supports formal reasoning about the behaviour of constructed systems, is presented. Specifications should accurately model the behaviour of real hardware and should be useful for design and validation; they should also be easy to write. In order to realise these goals, a number of specification techniques have been developed and a new language which enforces some of these techniques, thereby easing the specification task, is proposed. Ways in which a language may assist design have been investigated. Language constructs which restrict a designer, thereby removing some design decisions, have been developed. A simple correctness-preserving transformation is presented, illustrating another way in which a designer may be assisted by a formal language. Specification techniques play an important part in the validation task, as accurate and consistent modelling is vital in establishing the correctness of implementations. Techniques have also been developed which enable detailed implementations to be usefully compared with more abstract specifications. This is demonstrated in a large example, the specification, design and formal verification of a simple microprocessor. Finally, the concept of contextual constraints, restrictions on the environment in which a device may be placed, is introduced. A method of specifying such constraints has been developed, and it is shown that their formal treatment can provide assistance in specification, design and verification

    Experimental Evaluation of Mountain Bike Suspension Systems

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    A significant distinction between competitive mountain bikes is whether they have a suspension system. Research studies indicate that a suspension system gives advantages, but it is difficult to quantify the benefits because they depend on so many variables, including the physiology and psychology of the cyclist, the roughness of the track and the design of the suspension system. A laboratory based test rig has been built that allows the number of variables in the system to be reduced and test conditions to be controlled. The test rig simulates regular impacts of the rear wheel with bumps in a rolling road. The physiological variables of oxygen consumption and heart rate were measured, together with speeds and forces at various points in the system. Physiological and mechanical test results both confirm a significant benefit in using a suspension system on the simulated rough track, with oxygen consumption reduced by around 30 % and power transmitted through the pedals reduced by 30 % to 60 %

    Using a multivariate approach to define Irish metiers in the Irish Sea

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    There is an increasing need to take into account a “mixed fisheries” approach in management, assessment and sampling of fish stocks. To do this effectively it is necessary for groups of fishing trips with homogeneous fishing patterns or tactics to be defined into mĂ©tiers. Presented here is the result of an Irish case study analysis in applying multivariate statistics to declared logbook landings to define Irish fleet mĂ©tiers operating in the Irish Sea. Established multivariate statistical procedures, a combination of factorial and cluster analysis, were applied to five variables; landing profile, vessel length category, gear, mesh size range and month. The investigation has shown this methodology to be a suitable tool in identifying mĂ©tiers without prior assumptions and enabled data to be described from a multivariate statistical perspective providing useful and informative results. In total twenty-two mĂ©tiers were identified and defined from 2003 landings data, and a further 5 groups were formed to include trips which could not be assigned to a mĂ©tier. Definitions were applied to 2003-2005 landings and effort data to examine their dynamics and stability. The dominant mĂ©tier (in terms of effort and trips) contained high proportions of landed Nephrops taken by bottom otter trawlers using 70-89mm meshes. The effort in this mĂ©tier was fairly stable over time. The greatest increases in effort and trip allocation occurred within mĂ©tiers employing pots and traps for crustacean species. A small number of minor mĂ©tiers (in terms of landings and effort) became obsolete over the three years examined. The effects of recent management measures are likely to have contributed to declines in the numbers of trips and effort in some mĂ©tiers. For example, days-at-sea, limited mobile gears such as bottom otter trawls and beam trawls with ≄100mm mesh, have declined. Such changes within mĂ©tiers over recent years have contributed to a deeper understanding of fleet dynamics in the Irish Sea. This analysis has identified and highlighted a segment of polyvalent Irish fishing vessels, which move between several mĂ©tiers within a year. The definition of mĂ©tiers can be used to enhance the Irish sampling programme in the Irish Sea by developing a finer scale, mĂ©tier based, stratification of sampling. This in turn enables increased precision and robustness of national assessment data thus improving assessments and management advice. Defining mĂ©tiers will prove advantageous in developing mixed fisheries assessments and advice.Funder: Marine Institut
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