Leader-member exchange in a Chinese context:antecedents, outcomes and mediating role of psychological empowerment

This study examines organizational antecedents of LMX and the mediating influence of empowerment on the relationships between LMX and the work outcomes of job satisfaction, task performance and psychological withdrawal behavior. Data were obtained from employees of a listed Chinese company in Guangdong Province, People's Republic of China. The results revealed that: (a) supervisor control of rewards and work unit climate were related to LMX and (b) empowerment fully mediated the relationship between LMX and the work outcomes as hypothesized.

Studies on the generalisation of Gaussian processes and Bayesian neural networks

The assessment of the reliability of systems which learn from data is a key issue to investigate thoroughly before the actual application of information processing techniques to real-world problems. Over the recent years Gaussian processes and Bayesian neural networks have come to the fore and in this thesis their generalisation capabilities are analysed from theoretical and empirical perspectives. Upper and lower bounds on the learning curve of Gaussian processes are investigated in order to estimate the amount of data required to guarantee a certain level of generalisation performance. In this thesis we analyse the effects on the bounds and the learning curve induced by the smoothness of stochastic processes described by four different covariance functions. We also explain the early, linearly-decreasing behaviour of the curves and we investigate the asymptotic behaviour of the upper bounds. The effect of the noise and the characteristic lengthscale of the stochastic process on the tightness of the bounds are also discussed. The analysis is supported by several numerical simulations. The generalisation error of a Gaussian process is affected by the dimension of the input vector and may be decreased by input-variable reduction techniques. In conventional approaches to Gaussian process regression, the positive definite matrix estimating the distance between input points is often taken diagonal. In this thesis we show that a general distance matrix is able to estimate the effective dimensionality of the regression problem as well as to discover the linear transformation from the manifest variables to the hidden-feature space, with a significant reduction of the input dimension. Numerical simulations confirm the significant superiority of the general distance matrix with respect to the diagonal one.In the thesis we also present an empirical investigation of the generalisation errors of neural networks trained by two Bayesian algorithms, the Markov Chain Monte Carlo method and the evidence framework; the neural networks have been trained on the task of labelling segmented outdoor images.

The investigation of vegetation change using remote sensing to detect and monitor migration of landfill gas

Decomposition of domestic wastes in an anaerobic environment results in the production of landfill gas. Public concern about landfill disposal and particularly the production of landfill gas has been heightened over the past decade. This has been due in large to the increased quantities of gas being generated as a result of modern disposal techniques, and also to their increasing effect on modern urban developments. In order to avert diasters, effective means of preventing gas migration are required. This, in turn requires accurate detection and monitoring of gas in the subsurface. Point sampling techniques have many drawbacks, and accurate measurement of gas is difficult. Some of the disadvantages of these techniques could be overcome by assessing the impact of gas on biological systems. This research explores the effects of landfill gas on plants, and hence on the spectral response of vegetation canopies. Examination of the landfill gas/vegetation relationship is covered, both by review of the literature and statistical analysis of field data. The work showed that, although vegetation health was related to landfill gas, it was not possible to define a simple correlation. In the landfill environment, contribution from other variables, such as soil characteristics, frequently confused the relationship. Two sites are investigated in detail, the sites contrasting in terms of the data available, site conditions, and the degree of damage to vegetation. Gas migration at the Panshanger site was dominantly upwards, affecting crops being grown on the landfill cap. The injury was expressed as an overall decline in plant health. Discriminant analysis was used to account for the variations in plant health, and hence the differences in spectral response of the crop canopy, using a combination of soil and gas variables. Damage to both woodland and crops at the Ware site was severe, and could be easily related to the presence of gas. Air photographs, aerial video, and airborne thematic mapper data were used to identify damage to vegetation, and relate this to soil type. The utility of different sensors for this type of application is assessed, and possible improvements that could lead to more widespread use are identified. The situations in which remote sensing data could be combined with ground survey are identified. In addition, a possible methodology for integrating the two approaches is suggested.

Measuring the assessment and counselling provided with the supply of non-prescription asthma reliever medication: a simulated patient study

BACKGROUND: Over one quarter of asthma reliever medications are provided without prescription by community pharmacies in Australia. Evidence that community pharmacies provide these medications with sufficient patient assessment and medication counseling to ensure compliance with the government's Quality Use of Medicines principles is currently lacking. OBJECTIVE: To assess current practice when asthma reliever medication is provided in the community pharmacy setting and to identify factors that correlate with assessment of asthma control. METHODS: Researchers posing as patients visited a sample of Perth metropolitan community pharmacies in May 2007. During the visit, the simulated patient enacted a standardized scenario of someone with moderately controlled asthma who wished to purchase a salbutamol (albuterol) inhaler without prescription. Results of the encounter were recorded immediately after the visit. Regression analysis was performed, with medication use frequency (a marker of asthma control) as the dependent variable. RESULTS: One hundred sixty community pharmacies in the Perth metropolitan area were visited in May 2007. Pharmacists and/or pharmacy assistants provided some form of assessment in 84% of the visits. Counseling was provided to the simulated patients in 24% of the visits. Only 4 pharmacy staff members asked whether the simulated patient knew how to use the inhaler. Significant correlation was found between assessment and/or counseling of reliever use frequency and 3 independent variables: visit length (p < 0.001), number of assessment questions asked (p < 0.001), and the simulated patient who conducted the visit (p < 0.02). CONCLUSIONS: Both patient assessment and medication counseling were suboptimal compared with recommended practice when nonprescription asthma reliever medication was supplied in the community pharmacy setting. Pharmacy and pharmacist demographic variables do not appear to affect assessment of asthma control. This research indicates the need for substantial improvements in practice in order to provide reliever medication in line with Quality Use of Medication principles of ensuring safe and effective use of medication.

Effect of fatigue on consumers' advertising processing

Huge advertising budgets are invested by firms to reach and convince potential consumers to buy their products. To optimize these investments, it is fundamental not only to ensure that appropriate consumers will be reached, but also that they will be in appropriate reception conditions. Marketing research has focused on the way consumers react to advertising, as well as on some individual and contextual factors that could mediate or moderate the ad impact on consumers (e.g. motivation and ability to process information or attitudes toward advertising). Nevertheless, a factor that potentially influences consumers’ advertising reactions has not yet been studied in marketing research: fatigue. Fatigue can yet impact key variables of advertising processing, such as cognitive resources availability (Lieury 2004). Fatigue is felt when the body warns to stop an activity (or inactivity) to have some rest, allowing the individual to compensate for fatigue effects. Dittner et al. (2004) defines it as “the state of weariness following a period of exertion, mental or physical, characterized by a decreased capacity for work and reduced efficiency to respond to stimuli.’’ It signals that resources will lack if we continue with the ongoing activity. According to Schmidtke (1969), fatigue leads to troubles in information reception, in perception, in coordination, in attention getting, in concentration and in thinking. In addition, for Markle (1984) fatigue generates a decrease in memory, and in communication ability, whereas it increases time reaction, and number of errors. Thus, fatigue may have large effects on advertising processing. We suggest that fatigue determines the level of available resources. Some research about consumer responses to advertising claim that complexity is a fundamental element to take into consideration. Complexity determines the cognitive efforts the consumer must provide to understand the message (Putrevu et al. 2004). Thus, we suggest that complexity determines the level of required resources. To study this complex question about need and provision of cognitive resources, we draw upon Resource Matching Theory. Anand and Sternthal (1989, 1990) are the first to state the Resource Matching principle, saying that an ad is most persuasive when the resources required to process it match the resources the viewer is willing and able to provide. They show that when the required resources exceed those available, the message is not entirely processed by the consumer. And when there are too many available resources comparing to those required, the viewer elaborates critical or unrelated thoughts. According to the Resource Matching theory, the level of resource demanded by an ad can be high or low, and is mostly determined by the ad’s layout (Peracchio and Myers-Levy, 1997). We manipulate the level of required resources using three levels of ad complexity (low – high – extremely high). On the other side, the resource availability of an ad viewer is determined by lots of contextual and individual variables. We manipulate the level of available resources using two levels of fatigue (low – high). Tired viewers want to limit the processing effort to minimal resource requirements by making heuristics, forming overall impression at first glance. It will be easier for them to decode the message when ads are very simple. On the contrary, the most effective ads for viewers who are not tired are complex enough to draw their attention and fully use their resources. They will use more analytical strategies, looking at the details of the ad. However, if ads are too complex, they will be too difficult to understand. The viewer will be discouraged to process information and will overlook the ad. The objective of our research is to study fatigue as a moderating variable of advertising information processing. We run two experimental studies to assess the effect of fatigue on visual strategies, comprehension, persuasion and memorization. In study 1, thirty-five undergraduate students enrolled in a marketing research course participated in the experiment. The experimental design is 2 (tiredness level: between subjects) x 3 (ad complexity level: within subjects). Participants were randomly assigned a schedule time (morning: 8-10 am or evening: 10-12 pm) to perform the experiment. We chose to test subjects at various moments of the day to obtain maximum variance in their fatigue level. We use Morningness / Eveningness tendency of participants (Horne & Ostberg, 1976) as a control variable. We assess fatigue level using subjective measures - questionnaire with fatigue scales - and objective measures - reaction time and number of errors. Regarding complexity levels, we have designed our own ads in order to keep aspects other than complexity equal. We ran a pretest using the Resource Demands scale (Keller and Bloch 1997) and by rating them on complexity like Morrison and Dainoff (1972) to check for our complexity manipulation. We found three significantly different levels. After having completed the fatigue scales, participants are asked to view the ads on a screen, while their eye movements are recorded by the eye-tracker. Eye-tracking allows us to find out patterns of visual attention (Pieters and Warlop 1999). We are then able to infer specific respondents’ visual strategies according to their level of fatigue. Comprehension is assessed with a comprehension test. We collect measures of attitude change for persuasion and measures of recall and recognition at various points of time for memorization. Once the effect of fatigue will be determined across the student population, it is interesting to account for individual differences in fatigue severity and perception. Therefore, we run study 2, which is similar to the previous one except for the design: time of day is now within-subjects and complexity becomes between-subjects

The design of contact lens based ocular drug delivery systems for single-day use:part (I) structural factors, surrogate ophthalmic dyes and passive diffusion studies

The poor retention and efficacy of instilled drops as a means of delivering drugs to the ophthalmic environment is well-recognised. The potential value of contact lenses as a means of ophthalmic drug delivery, and consequent improvement of pre-corneal retention is one obvious route to the development of a more effective ocular delivery system. Furthermore, the increasing availability and clinical use of daily disposable contact lenses provides the platform for the development of viable single-day use drug delivery devices based on existing materials and lenses. In order to provide a basis for the effective design of such devices, a systematic understanding of the factors affecting the interaction of individual drugs with the lens matrix is required. Because a large number of potential structural variables are involved, it is necessary to achieve some rationalisation of the parameters and physicochemical properties (such as molecular weight, charge, partition coefficients) that influence drug interactions. Ophthalmic dyes and structurally related compounds based on the same core structure were used to investigate these various factors and the way in which they can be used in concert to design effective release systems for structurally different drugs. Initial studies of passive diffusional release form a necessary precursor to the investigation of the features of the ocular environment that over-ride this simple behaviour. Commercially available contact lenses of differing structural classifications were used to study factors affecting the uptake of the surrogate actives and their release under 'passive' conditions. The interaction between active and lens material shows considerable and complex structure dependence, which is not simply related to equilibrium water content. The structure of the polymer matrix itself was found to have the dominant controlling influence on active uptake; hydrophobic interaction with the ophthalmic dye playing a major role. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.