992 research outputs found

    An efficient feti based solver for elasto-plastic problems of mechanics

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    This paper illustrates how to implement effectively solvers for elasto-plastic problems. We consider the time step problems formulated by nonlinear variational equations in terms of displacements. To treat nonlinearity and nonsmoothnes we use semismooth Newton method. In each Newton iteration we have to solve linear system of algebraic equations and for the numerical solution of the linear systems we use TFETI algorithm. In our benchmark we compute von Misses plasticity with isotropic hardening and use return mapping concept

    The METCRAX II Field Experiment: A Study of Downslope Windstorm-Type Flows in Arizona\u2019s Meteor Crater

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    The second Meteor Crater Experiment (METCRAX II) was conducted in October 2013 at Arizona\u2019s Meteor Crater. The experiment was designed to investigate nighttime downslope windstorm 12type flows that form regularly above the inner southwest sidewall of the 1.2-km diameter crater as a southwesterly mesoscale katabatic flow cascades over the crater rim. The objective of METCRAX II is to determine the causes of these strong, intermittent, and turbulent inflows that bring warm-air intrusions into the southwest part of the crater. This article provides an overview of the scientific goals of the experiment; summarizes the measurements, the crater topography, and the synoptic meteorology of the study period; and presents initial analysis results

    What determines auditory similarity? The effect of stimulus group and methodology.

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    Two experiments on the internal representation of auditory stimuli compared the pairwise and grouping methodologies as means of deriving similarity judgements. A total of 45 undergraduate students participated in each experiment, judging the similarity of short auditory stimuli, using one of the methodologies. The experiments support and extend Bonebright's (1996) findings, using a further 60 stimuli. Results from both methodologies highlight the importance of category information and acoustic features, such as root mean square (RMS) power and pitch, in similarity judgements. Results showed that the grouping task is a viable alternative to the pairwise task with N > 20 sounds whilst highlighting subtle differences, such as cluster tightness, between the different task results. The grouping task is more likely to yield category information as underlying similarity judgements

    A push–pull strategy to suppress stable fly (Diptera: Muscidae) attacks on pasture cattle via a coconut oil fatty acid repellent formulation and traps with \u3ci\u3em\u3c/i\u3e-cresol lures

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    BACKGROUND: Stable flies [Stomoxys calcitrans (L.)] are economically important pests of cattle and other livestock. As an alternative to conventional insecticides, we tested a push–pull management strategy using a coconut oil fatty acid repellent formulation and an attractant-added stable fly trap. RESULTS: In our field trials we found that weekly applications of a push–pull strategy can reduce stable fly populations on cattle as well as a standard insecticide (permethrin). We also found that the efficacy periods of the push–pull and permethrin treatments following on-animal application were equivalent. Traps with an attractant lure used as the pull component of the push–pull strategy captured sufficient numbers of stable flies to reduce on-animal numbers by an estimated 17–21%. CONCLUSIONS: This is the first proof-of-concept field trial demonstrating the effectiveness of a push–pull strategy using a coconut oil fatty acid-based repellent formulation and traps with an attractant lure to manage stable flies on pasture cattle. Also notable is that the push–pull strategy had an efficacy period equivalent to that of a standard, conventional insecticide under field conditions

    Inhibition of the glycaemic response by onion : a comparison between lactose-tolerant and lactose-intolerant adults

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    This document is the Accepted Manuscript of the following article: R Hoffman, G Ranjbar and A M Madden, ‘Inhibition of the glycaemic response by onion: a comparison between lactose-tolerant and lactose-intolerant adults’, European Journal of Clinical Nutritin, (2016), 70: 1089-1091. The Version of Record is available online at doi: 10.1038/ejcn.2016.44.This pilot study compared inhibition of the glycaemic response to glucose by a dietary source of quercetin glucosides (onion) in lactose-tolerant adults (n = 12) and lactose-intolerant adults (n = 12). We hypothesised that lactose-intolerant people (who do not express lactase) will retain intact quercetin glucosides that can inhibit glucose uptake via the glucose transporter SGLT1 whereas lactose-tolerant people (who do express lactase) will hydrolyse quercetin glucosides to free quercetin which does not inhibit glucose uptake. In a glucose tolerance test, reduction of peak glucose levels by an onion meal was higher in lactose-intolerant people than lactose-tolerant people (44.2% versus 19.3%, p = 0.04). Incremental area under the blood glucose curve was reduced more in lactose-intolerant people, but was not statistically significantly (54.5% versus 42.1%, p = 0.42). A diet containing quercetin glucosides may be of greater benefit for glycaemic control in lactose-intolerant people than in lactose-tolerant people.Peer reviewedFinal Accepted Versio

    Nitrogen in Current European Policies

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    Europe, and especially the European Union (EU), has many governmental policy ¿ measures aimed at decreasing unwanted reactivenitrogen (N r ) emissions from combustion, agriculture and urban wastes. Many of these policy measures have an ¿eff ects-basedapproach¿, and focus on single N r compounds, single sectors and either on air or waters.¿ Th is chapter addresses the origin, objectives and targets of EU policy measures related to Nr emissions, considers which instrumentsare being used to implement the policies and briefl y discusses the eff ects of the policy measures.Approaches¿ Th e chapter starts with a brief description of the basic elements of governmental policy measures.¿ A review of the main international conventions and EU policies related to emissions of Nr to air and water is then provided.¿ Finally the chapter provides a semi-quantitative assessment of the eff ectiveness and effi ciency of European policy measures.Key fi ndings/state of knowledge¿ International conventions and other treaties have played a key role in raising awareness and establishing policy measures for Nr emissionsabatement in EU through so-called Directives and Regulations.¿ Th ere are many diff erent EU Directives, oft en addressing individual Nr compounds from individual sectors (e.g. NOx emissions fromcombustion; NH 3 emissions from agriculture, pollution of groundwater and surface water by nitrates from agriculture, discharge oftotal nitrogen from urban sewage to surface waters).¿ Many EU Directives have been revised following review and evaluation. Th ere are increasing eff orts to cluster single EU Directives intolarger Framework Directives.¿ Compliance with, and eff ectiveness of, the Directives diff ers between sectors; it decreases in the order (i) reducing NO x emissions fromcombustion sources, (ii) reducing nitrogen (and especially Phosphorus) discharges to waters from industries and households, and (iii)reducing NH 3 emissions and NO 3 leaching from agriculture.¿ Th ere is not much literature on the diff erences in the eff ectiveness and effi ciencies of Directives; a number of factors seem to be involvedin eff ectiveness and effi ciency, but these have not yet been analysed in a coherent manner.Major uncertainties/challenges¿ Th ere is a huge diversity in N r emission sources and pathways, while the number of policy instruments is limited. Th ere is need to fi ndthe optimal mix of policy instruments targeted to the emission sources as well as the stakeholders involved.¿ It has been indicated that some EU Directives addressing emissions of nitrogen compounds from specifi c sources have antagonisticeff ects. Th e magnitude of these eff ects is not yet well known.¿ Th ere is a delay in the environmental and ecological responses following the introduction of Directives; these are due to legislativedelays, lack of enforcement and control, constraints in practice and because of biogeochemical hysteresis eff ects; these eff ects are notyet well understood quantitatively.¿ In general, only modest reductions in Nr emissions from agriculture have been achieved to date; this refl ects the need for more eff ectiveand effi cient policy measures and/or greater enforcement of current policies.Recommendations¿ To examine further the diff erences between sectors of the factors that contribute to the eff ectiveness and effi ciency of policy measuresfor the abatement of N r emissions.¿ T o explore further the eff ectiveness and effi ciency of more integrated N management and integrated policy measures for the abatementof adverse impacts of N r emissions.JRC.DDG.H.2-Climate change and air qualit

    Reminiscence bump in memory for public events

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    People tend to recall more personal events from adolescence and early adulthood than from other lifetime periods. Most evidence suggests that differential encoding causes this reminiscence bump. However, the question why personal events are encoded better in those periods is still unanswered. To shed more light on this discussion, we examined memory for public events. Since it is often impossible to ascertain that queried events are equally difficult, we circumvented the issue of equivalence by calculating deviation scores for each trial. We found that participants more frequently answered questions correctly about events that occurred in the period in which they were between 10 and 25 years old. Furthermore, we found that the reminiscence bump was more pronounced for cued recall than for recognition. We argue that these results support the biological account that events are stored better, because the memory system is working more efficiently during adolescence and early adulthood. These results do not falsify the other accounts for differential encoding, because they are not mutually exclusive. People speak of autobiographical memory when they are referring to the memories they have of their own life experiences (Robinson, 1986). Autobiographical memory does not only consist of personal memories that are remembered vividly, but also of autobiographical facts (Brewer, 1986). Some researchers have examined the contents of autobiographical memories (e.g., Fitzgerald, 1988; Niedźwieńska, 2003; Robinson, 1976), whereas other researchers have focused on the temporal distribution of memories of personal events across the lifespan (e.g., Janssen, Chessa, &amp
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