87 research outputs found
Should I Stay or should I Go?: The Effects of Student Individual Differences on Stress and Estimated Gains from the University Experience
The aim of this thesis was to identify factors at the commencement of university
study that may enable prediction of both estimate of gains and experience of
stresses. This was done in order to provide information that may enable early
identification of risk factors in respect to student attrition. To this end, the thesis
examined individual differences amongst students that relate to perception of
both estimated gains and stress early in the university experience. Initially, the
individual differences studied were those relating to student demographics of
age, gender, whether the student performed additional part-time work and the
number of hours of work performed and the influence of finances. This first
round of testing was performed by distributing questionnaires examining the
aforementioned via student welcome packs at commencement of university
study. The results of this first round of testing suggested particular importance
of intrinsic values on estimated gains. In addition to some influence of finances,
gender and hours of work. From open questions present in this first round of
testing, focus group questions were formulated in order to further develop the
questionnaire. From the findings of study two, this was then expanded to
include the influence of perceived demands, control and support and locus of
control on estimated gains and subjective perceived stress. This was again
performed by distributing a questionnaire at inception, albeit personally to help
response rate and answer any queries. This third round of testing, as implied
by the focus group responses, found an additional influence of locus of control
and the perception of demands, control and support on estimated gains and
stress. Finally, the fourth round of testing included biological indicators of
stress, namely salivary cortisol levels through the use of analysis of levels of salivary cortisol, collected using a salivette. This final study suggested a
difference in the effects of perceived demands, control and support on both
perceived and biological responses to stress The study in all found that there is
a definite prediction of estimate of gains from the university environment by the
work values studied. Although it was found that gains were primarily influenced
by intrinsic values (achievement, advancement, autonomy, personal
development), an influence of extrinsic values (economics, prestige, social
interaction) was also evident. In addition to work values, demographics of
gender, age and hours of work were also found to influence differences in
estimated gains and stress. None of the values studied were found to predict
perceived stress, however the distinction between perceived and objective
biological measures of stress was highlighted. In particular, with regard to the
perception of demands, control and support from the university environment.
The results of the study also suggested that the extent to which students
perceive demands, control and support from the university environment may
also have an impact on the student experience of stress, particularly biological
stress, which can result in potential harm to physical well-being
A Comparison of the Reactivity of the Lattice Nitrogen in Tungsten Substituted Co3Mo3N and Ni2Mo3N
The effect of the partial substitution of Mo with W in Co3Mo3N and Ni2Mo3N on ammonia synthesis activity and lattice nitrogen reactivity has been investigated. This is of interest as the coordination environment of lattice N is changed by this process. When tungsten was introduced into the metal nitrides by substitution of Mo atoms, the catalytic performance was observed to have decreased. As expected, Co3Mo3N was reduced to Co6Mo6N under a 3:1 ratio of H2/Ar. Co3Mo2.6W0.4N was also shown to lose a large percentage of lattice nitrogen under these conditions. The bulk lattice nitrogen in Ni2Mo3N and Ni2Mo2.8W0.2N was unreactive, demonstrating that substitution with tungsten does not have a significant effect on lattice N reactivity. Computational calculations reveal that the vacancy formation energy for Ni2Mo3N is more endothermic than Co3Mo3N. Furthermore, calculations suggest that the inclusion of W does not have a substantial impact on the surface N vacancy formation energy or the N2 adsorption and activation at the vacancy site
Methodological approaches to determining the marine radiocarbon reservoir effect
The marine radiocarbon reservoir effect is an offset in 14C age between contemporaneous organisms from the terrestrial environment and organisms that derive their carbon from the marine environment. Quantification of this effect is of crucial importance for correct calibration of the <sup>14</sup>C ages of marine-influenced samples to the calendrical timescale. This is fundamental to the construction of archaeological and palaeoenvironmental chronologies when such samples are employed in <sup>14</sup>C analysis. Quantitative measurements of temporal variations in regional marine reservoir ages also have the potential to be used as a measure of process changes within Earth surface systems, due to their link with climatic and oceanic changes. The various approaches to quantification of the marine radiocarbon reservoir effect are assessed, focusing particularly on the North Atlantic Ocean. Currently, the global average marine reservoir age of surface waters, R(t), is c. 400 radiocarbon years; however, regional values deviate from this as a function of climate and oceanic circulation systems. These local deviations from R(t) are expressed as +R values. Hence, polar waters exhibit greater reservoir ages (δR = c. +400 to +800 <sup>14</sup>C y) than equatorial waters (δR = c. 0 <sup>14</sup>C y). Observed temporal variations in δR appear to reflect climatic and oceanographic changes. We assess three approaches to quantification of marine reservoir effects using known age samples (from museum collections), tephra isochrones (present onshore/offshore) and paired marine/terrestrial samples (from the same context in, for example, archaeological sites). The strengths and limitations of these approaches are evaluated using examples from the North Atlantic region. It is proposed that, with a suitable protocol, accelerator mass spectrometry (AMS) measurements on paired, short-lived, single entity marine and terrestrial samples from archaeological deposits is the most promising approach to constraining changes over at least the last 5 ky BP
A Comparison of the reactivity of the lattice nitrogen in tungsten substituted Co3Mo3N and Ni2Mo3N
The effect of the partial substitution of Mo with W in Co3Mo3N and Ni2Mo3N on ammonia synthesis activity and lattice nitrogen reactivity has been investigated. This is of interest as the coordination environment of lattice N is changed by this process. When tungsten was introduced into the metal nitrides by substitution of Mo atoms, the catalytic performance was observed to have decreased. As expected, Co3Mo3N was reduced to Co6Mo6N under a 3 : 1 ratio of H2/Ar. Co3Mo2.6W0.4N was also shown to lose a large percentage of lattice nitrogen under these conditions. The bulk lattice nitrogen in Ni2Mo3N and Ni2Mo2.8W0.2N was unreactive, demonstrating that substitution with tungsten does not have a significant effect on lattice N reactivity. Computational calculations reveal that the vacancy formation energy for Ni2Mo3N is more endothermic than Co3Mo3N. Furthermore, calculations suggest that the inclusion of W does not have a substantial impact on the surface N vacancy formation energy or the N2 adsorption and activation at the vacancy site
Mathematical modelling of polyamine metabolism in bloodstream-form trypanosoma brucei: An application to drug target identification
© 2013 Gu et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedThis article has been made available through the Brunel Open Access Publishing Fund.We present the first computational kinetic model of polyamine metabolism in bloodstream-form Trypanosoma brucei, the causative agent of human African trypanosomiasis. We systematically extracted the polyamine pathway from the complete metabolic network while still maintaining the predictive capability of the pathway. The kinetic model is constructed on the basis of information gleaned from the experimental biology literature and defined as a set of ordinary differential equations. We applied Michaelis-Menten kinetics featuring regulatory factors to describe enzymatic activities that are well defined. Uncharacterised enzyme kinetics were approximated and justified with available physiological properties of the system. Optimisation-based dynamic simulations were performed to train the model with experimental data and inconsistent predictions prompted an iterative procedure of model refinement. Good agreement between simulation results and measured data reported in various experimental conditions shows that the model has good applicability in spite of there being gaps in the required data. With this kinetic model, the relative importance of the individual pathway enzymes was assessed. We observed that, at low-to-moderate levels of inhibition, enzymes catalysing reactions of de novo AdoMet (MAT) and ornithine production (OrnPt) have more efficient inhibitory effect on total trypanothione content in comparison to other enzymes in the pathway. In our model, prozyme and TSHSyn (the production catalyst of total trypanothione) were also found to exhibit potent control on total trypanothione content but only when they were strongly inhibited. Different chemotherapeutic strategies against T. brucei were investigated using this model and interruption of polyamine synthesis via joint inhibition of MAT or OrnPt together with other polyamine enzymes was identified as an optimal therapeutic strategy.The work was carried out under a PhD programme partly funded by Prof. Ray Welland, School of Computing Science, University of Glasgo
Integrating personality research and animal contest theory: aggressiveness in the green swordtail <i>Xiphophorus helleri</i>
<p>Aggression occurs when individuals compete over limiting resources. While theoretical studies have long placed a strong emphasis on context-specificity of aggression, there is increasing recognition that consistent behavioural differences exist among individuals, and that aggressiveness may be an important component of individual personality. Though empirical studies tend to focus on one aspect or the other, we suggest there is merit in modelling both within-and among-individual variation in agonistic behaviour simultaneously. Here, we demonstrate how this can be achieved using multivariate linear mixed effect models. Using data from repeated mirror trials and dyadic interactions of male green swordtails, <i>Xiphophorus helleri</i>, we show repeatable components of (co)variation in a suite of agonistic behaviour that is broadly consistent with a major axis of variation in aggressiveness. We also show that observed focal behaviour is dependent on opponent effects, which can themselves be repeatable but were more generally found to be context specific. In particular, our models show that within-individual variation in agonistic behaviour is explained, at least in part, by the relative size of a live opponent as predicted by contest theory. Finally, we suggest several additional applications of the multivariate models demonstrated here. These include testing the recently queried functional equivalence of alternative experimental approaches, (e. g., mirror trials, dyadic interaction tests) for assaying individual aggressiveness.</p>
Financial control, blame avoidance and Radio Caroline: Talkin’ ‘bout my generation
This research examines the use of financial mechanisms that simultaneously impose controls and facilitate blame avoidance by public office-holders. A qualitative historical examination is used to examine legislation designed to prevent Radio Caroline, a pirate radio station, from broadcasting into Britain in the 1960s. Radio Caroline made a mockery of the British Government’s power to manage radio through a monopolist, the British Broadcasting Corporation. In addition, Radio Caroline played the type of rock music the British Government sought to suppress as representing the undesirable side of youth culture. This research examines the suppression of Radio Caroline through the Marine & Broadcasting (Offences) Act (UK) 1967 and the legislative scapegoating of Radio Caroline by targeting its revenue-earning potential. Inter-generational conflict underpinned the legislative scapegoating of Radio Caroline. This research demonstrates how financial controls can mask scapegoating and blame avoidance strategies by governments
Intelligence, reason of state and the art of governing risk and opportunity in early modern Europe
Drawing upon primary and secondary historical material, this paper explores the role of intelligence in early modern government. It focuses upon developments in seventeenth- and early-eighteenth-century England, a site-specific genealogical moment in the broader history of state power/knowledges. Addressing a tendency in Foucauldian work to neglect pre-eighteenth-century governance, the analysis reveals a set of interrelated processes which gave rise to an innovative technique for anticipating hazard and opportunity for the state. At the intersection of raison d’État, the evolving art of government, widespread routines of secrecy and a post-Westphalia field of European competition and exchange, intelligence was imagined as a fundamental solution to the concurrent problems of ensuring peace and stability while improving state forces. In the administrative offices of the English Secretary of State, an assemblage of complex and interrelated procedures sought to produce and manipulate information in ways which exposed both possible risks to the state and potential opportunities for expansion and gain. As this suggests, the art of intelligence played an important if largely unacknowledged role in the formation and growth of the early modern state. Ensuring strategic advantage over rivals, intelligence also limited the ability of England's neighbours to dominate trade, control the seas and master the colonies, functioning as a constitutive feature of European balance and equilibrium. As the analysis concludes, understanding intelligence as a form of governmental technique – a way of doing something – reveals an entirely novel way of thinking about and investigating its myriad (historical and contemporary) formations
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