9,292 research outputs found
Changes in lipophorins are related to the activation of phenoloxidase in the haemolymph of Locusta migratoria in response to injection of immunogens
In Locusta migratoria, activation of phenoloxidase in the haemolymph in response to injection of laminarin is age-dependent: being absent in fifth instar nymphs and newly emerged adults, and only becoming evident four days after the final moult. This pattern of change in phenoloxidase activation correlates with the pattern of change in the concentration of apolipophorin-III (apoLp-III) in the haemolymph. Injection of a conspecific adipokinetic hormone (Lom-AKH-I) has no effect on the phenoloxidase response in nymphs or newly emerged adults but, in adults older than four days, co-injection of the hormone with laminarin prolongs the activation of phenoloxidase in the haemolymph: a similar enhancement of the response to laminarin is observed in locusts that have been starved for 48 h but not injected with AKH-I. During most of the fifth stadium, injection of laminarin results in a decrease in the level of prophenoloxidase in the haemolymph; an effect that is not observed in adults of any age. Marked changes in the concentration of apoLp-III, and the formation of LDLp in the haemolymph, are observed after injection of laminarin (or LPS) and these are remarkably similar, at least qualitatively, to those that occur after injection of AKH-I. The involvement of lipophorins in the activation of locust prophenoloxidase in response to immunogens is discussed
Adult numeracy and the conversion to the euro in the Slovak Republic
This thesis investigates Slovak citizens’ attitudes towards the Euro changeover and the numerical demands imposed on them in the context of the currency change. The numerical demands varied considerably from country to country depending on the simplicity or complexity of the conversion rates. This research into currency change follows in the tradition of economic psychology. A number of studies have examined the problems with currency conversion, including the development of price intuition, using this approach (Marques and Dehaene, 2004; Ranyard et al., 2003; Hofmann et al., 2007). The present research draws on this, and in particular on ideas from the ‘Psycho-Social’ (Hofmann et al., 2007) approach within the economic psychology and from Adult Numeracy tradition (Evans, 2000; Lave, 1988). The model used here studies the relationship between cognitive performance and affective variables, an approach based on Evans (2000). This account of the currency changeover emphasises the importance of the context in which numerical thinking takes place, and aims to study the adult learner with conversion/calculation tasks in everyday life contexts. In order to illustrate the support given by the state, organisations and communities on national and local levels to guide the currency conversion, descriptions of various documents are presented. This repeated cross-sectional study elicits responses from a series of representative samples of citizens in the Slovak Republic on their attitudes to the Euro, their context specific conversion strategies (Hofmann et al., 2007), and the development of ‘price intuition’ (Marques and Dehaene, 2004). Respondents were selected based on a tightly designed quota sampling method, controlling for region, age and gender to collect the required number of responses from each group. The research was conducted at five different points in time: the ‘pilot study’ was conducted before the introduction of the Euro in April 2008; Phase 1 took place during the dual circulation in January 2009, Phase 2 in August 2009; and Phase 3 in January 2011. All four phases used primary survey data. Additional clinical interviews were conducted in July 2012. Some results are compared to the Eurobarometer surveys conducted in other EU countries to place the findings in a broader context. A key idea is that of an adaptation strategy. Hofmann et al., (2007) proposed that there were four different forms of adaptation: a conversion strategy, an anchor strategy, a marker value strategy, and an intuitive strategy. At the beginning of the Euro changeover, the conversion strategy was the most frequently used strategy by all socio-economic groups and none of the other strategies were used very often. However, two years after the changeover citizens became more selective and used different adaptation strategies for different problem solving tasks with the intuitive strategy being the most frequently applied. Furthermore, Slovak citizens share some common concerns with citizens of other countries, such as the perception that prices in the Euro currency appear cheaper; something known as the ‘Euro Illusion’. The illusion was stronger when people started to rely on intuition to make purchasing decisions. Overall, the empirical results show that the Slovak citizens adapted rather well to the new currency and the policy makers managed to avoid unexpected price increases which were common in other Eurozone countries. The experience and lessons learnt could be informative and supportive for new entrants and policy makers, as the Euro is likely to be introduced in other countries, particularly Central and Eastern European countries. Since this study has been done the Euro has been introduced in Estonia and Latvia could be joining as early as January 2014 followed by Lithuania in 2015
The Effect of Schooling and Ability on Achievement Test Scores
This paper develops two methods for estimating the effect of schooling on achievement test scores that control for the endogeneity of schooling by postulating that both schooling and test scores are generated by a common unobserved latent ability. These methods are applied to data on schooling and test scores. Estimates from the two methods are in close agreement. We find that the effects of schooling on test scores are roughly linear across schooling levels. The effects of schooling on measured test scores are slightly larger for lower latent ability levels. We find that schooling increases the AFQT score on average between 2 and 4 percentage points, roughly twice as large as the effect claimed by Herrnstein and Murray (1994) but in agreement with estimates produced by Neal and Johnson (1996) andWinship and Korenman (1997). We extend the previous literature by estimating the impact of schooling on measured test scores at various quantiles of the latent ability distribution.
IUS solid rocket motor contamination prediction methods
A series of computer codes were developed to predict solid rocket motor produced contamination to spacecraft sensitive surfaces. Subscale and flight test data have confirmed some of the analytical results. Application of the analysis tools to a typical spacecraft has provided early identification of potential spacecraft contamination problems and provided insight into their solution; e.g., flight plan modifications, plume or outgassing shields and/or contamination covers
The Collaborative Development of New CFD Methods Adapted for Tilt Rotor Aircraft in the HiPerTilt Project
No abstract available
The effect of schooling and ability on achievement test scores
This paper develops two methods for estimating the effect of schooling on achievement test scores that control for endogeneity of schooling by postulating that both schooling and test scores are generated by a common unobserved latent ability. These methods are applied to data on schooling and test scores. Estimates from the two methods are in close agreement. We find that the effects of schooling on test scores are roughly linear across schooling levels. The effects of schooling on measured test scores are slightly larger for lower latent ability levels. We find that schooling increases the AFQT score on average between 2 and 4 percentage points, roughly twice as large as the effect claimed by Herrnstein and Murray (1994) but in agreement with estimates produced by Neal and Johnson (1996) and Winship and Korenman (1997). We extend the previous literature by estimating the impact of schooling on measured test scores at various quantiles of the latent ability distribution.Education; ability; latent variables; selection; MCMC
Soil Properties and their Influence on Grassland Production under Low Input and Organic Farming Conditions
End of project reportThis project set out to identify soil properties that most influence grassland production under low mineral nitrogen input conditions. Sixteen farms were selected in Counties Limerick and Clare and the soil sampled. Soil physical and chemical characteristics and soil biological aspects involved in the carbon and nitrogen cycles were studied in the laboratory. Nutrient additions to farms as well as the nature of grazing by livestock (numbers, types of grazing animals, grazing practices), grassland management, and production from the farms were recorded
Waveguide physical modeling of vocal tract acoustics: flexible formant bandwidth control from increased model dimensionality
Digital waveguide physical modeling is often used as an efficient representation of acoustical resonators such as the human vocal tract. Building on the basic one-dimensional (1-D) Kelly-Lochbaum tract model, various speech synthesis techniques demonstrate improvements to the wave scattering mechanisms in order to better approximate wave propagation in the complex vocal system. Some of these techniques are discussed in this paper, with particular reference to an alternative approach in the form of a two-dimensional waveguide mesh model. Emphasis is placed on its ability to produce vowel spectra similar to that which would be present in natural speech, and how it improves upon the 1-D model. Tract area function is accommodated as model width, rather than translated into acoustic impedance, and as such offers extra control as an additional bounding limit to the model. Results show that the two-dimensional (2-D) model introduces approximately linear control over formant bandwidths leading to attainable realistic values across a range of vowels. Similarly, the 2-D model allows for application of theoretical reflection values within the tract, which when applied to the 1-D model result in small formant bandwidths, and, hence, unnatural sounding synthesized vowels
Thermoelectric energy harvester with a cold start of 0.6 °C
This paper presents the electrical and thermal design of a thermoelectric energy harvester power system and its characterisation. The energy harvester is powered by a single Thermoelectric Generator (TEG) of 449 couples connected via a power conditioning circuit to an embedded processor. The aim of the work presented in this paper is to experimentally confirm the lowest ΔT measured across the TEG (ΔTTEG) at which the embedded processor operates to allow for wireless communication.
The results show that when a temperature difference of 0.6 °CΔTTEG is applied across the thermoelectric module, an input voltage of 23 mV is generated which is sufficient to activate the energy harvester in approximately 3 minutes. An experimental setup able to accurately maintain and measure very low temperatures is described and the electrical power generated by the TEG at these temperatures is also described. It was found that the energy harvester power system can deliver up to 30 mA of current at 2.2 V in 3ms pulses for over a second. This is sufficient for wireless broadcast, communication and powering of other sensor devices.
The successful operation of the wireless harvester at such low temperature gradients offers many new application areas for the system, including those powered by environmental sources and body heat
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