The thesis investigated perception of facial identity and attractiveness with digital manipulation of facial traits. A presentation time paradigm was developed by which stimuli could be presented for a range of brief display periods. Using this paradigm subjects recognised photo-realistic target faces caricatured in shape with greater accuracy than veridical images consistent with previous findings using reaction time as a measure. Subjects were further required to identify colour representations of famous faces which were either veridical, caricatured in colour space or had enhanced colour saturation and intensity contrast (as contrast controls). Recognition accuracy was greater when viewing the colour-caricatured stimuli than either the veridical images or the contrast controls. The removal of colour to produce grey-scale images also decreased accuracy of face recognition indicating that colour information aids facial identification. Caricaturing of faces, therefore, can be extended to the colour domain and, as with shape caricaturing, enhancement of distinctive information can produce a recognition advantage for famous faces. Subjects were also asked to identify the best-likeness for individuals using photo-realistic stimuli and an interactive paradigm with shape-caricature, colour-caricature and contrast-control varied by the user in real-time. The best-likeness with shape manipulation was a slight anti-caricature while with colour-caricature and contrast-control images a mildly exaggerated image was selected as the best-likeness. Thus although images caricatured substantially in colour or shape (+40%) induce superior recognition compared to veridical images such substantial exaggerations are not seen as best-likenesses under prolonged exposure. The gender typicality for white British and Japanese composite faces was manipulated and subjects presented with the images using both a static forced-choice paradigm and an interactive paradigm. Male and female face shapes with enhanced feminine features were consistently found to be more attractive than average. Preference for enhanced femininity for female faces was greater for subjects making within- than cross-cultural judgements.

The main ongoing debate within the recently-established field of Third Language (L3) Acquisition revolves around which of the previously-acquired languages prevails as a source of cross-linguistic influence (CLI) during production in the target language. Whereas several factors have been found to promote CLI, the existing body of L3 research points to a potential stronger rivalry between two of them: typology, or the relative distance among the languages involved, and second language (L2) status, also known as foreign language effect. In fact, they are at the core of two models of multilingual transfer that stem from the area of L3 morphosyntax, namely the Typology Primacy Model (TPM; Rothman, 2010, 2011, 2013, 2015), and the L2 Status Factor Model (L2 SFM; Bardel & Falk, 2007, 2012). For the most part, claims backing a more determinant role for typology come from studies investigating lexis. Whether or not typology overrides the effect of the L2 with regards to syntax and phonology as well is less clear. On the one hand, studies focusing on syntactic CLI can be divided into those whose findings suggest a crucial role either for the L1 (Na Raong & Leung, 2009) or for the L2 (Bardel & Falk, 2007), those in which findings point to typology as the deciding factor in determining a source of CLI (Rothman, 2011), and those that fail to show any influence from the L2 on the L3 (Håkansson, Pienemann, & Sayehli, 2002) even when the L2 and the L3 are typologically close (Martínez Adrián, 2005). On the other hand, results from previous research investigating phonological CLI also yield three main distinct findings: i) a more marked L2 effect (Llama, Cardoso & Collins, 2010), ii) a predominant influence from the first language (L1; Llisterri & Poch, 1987), and iii) combined CLI, that is, the L1 and the L2 concur in influencing the L3 (Wrembel, 2014). The primary goal of this dissertation is to add to the debate by looking into all three sub-areas among trilinguals at a high-intermediate to advanced level of proficiency, which has been the least targeted proficiency level until now. The selected topics, per area, are: lexical inventions, relative clause attachment preferences (RCA), and voice onset time (VOT). The secondary goal was to compare the relative influences of typology and L2 status across sub-areas, and to examine all results in light of three of the current L3 multilingual transfer models, the TPM, the L2 SFM, and the Cumulative Enhancement Model (CEM; Flynn, Foley, & Vinnitskaya, 2004). The results obtained are in clear agreement with previous reports in the area of lexis. However, the interplay of our trilinguals’ linguistic systems with regard to RCA and VOT is more complex. Findings in these areas seem to suggest that other factors (language exposure in the case of RCA, and the L1, in the case of VOT) may trump the two under investigation.

This thesis describes the results of a course of experimental research into the optical properties of manganese impurities in the II-VI host lattices ZnSe, ZnS, and ZnSe[sub]xS1−[sub]x. These materials are of some commercial importance, since they exhibit electroluminescence when appropriately prepared. For this reason it is desirable to ascertain which inherent properties of the materials would determine device performance, and to try to distinguish these from apparently limiting criteria which are in fact cause by unknown and unwanted defects. Removal of such undesirable impurities may substantially benefit device performance. These materials are also of interest in that they exhibit some of the more complex properties of solids which can only be studied by the selection of a material which manifests the effects in question. That is, although the effects are studied in these compounds, it is to be expected that they will also occur more generally, although not perhaps as obviously. In order to fully appreciate some of the more complex effects which are studied, it is necessary to provide a substantial theoretical background. This is the function of chapters two, three, and four in this work. Chapter two is an introduction to the fundamental problem of transition metal impurities in solids, together with an indication of the approaches which have been made, and the approximation invoked. In chapter three the general problem of electron lattice interactions is discussed, with the aim being to offer an insight into the Jahn-Teller and Ham effects. Chapter four deals more specifically with the zero- phonon lines, including a mechanism which had hitherto received scant attention in this context. The details of the experimental apparatus and techniques are given in chapter 5, together with computational methods. Also included in this chapter is a method of determining mixed crystal composition, applicable to the ZnSe[sub]xS1-[sub]x system which is much simpler than other techniques which have been employed. Chapter six reports the results of investigations into the zero-phonon lines in ZnSe:Mn. These results are interpreted in terms of the Jahn-Teller and Ham effects, and from the type of broadening mechanism invoked to explain the temperature dependence of the lines, a more accurate assignation of the energies of states split by the spin-orbit and Jahn-Teller interactions is made. The broadening mechanism invoked is of some importance, since it appears to have been largely ignored in studies on zero-phonon lines, although it is well known in those on spin-lattice relaxation. In chapter 7, the problem of non-radiative transitions in all three materials is studied, with the emphasis being on the limitations which they inflict on possible devices. Radiationless processes are considered first of all by investigating thermal dependence of emission intensity, and secondly by examining the effects of temperature on the lifetime of the excited state involved in the transition. It is demonstrated that the thermal quenching of luminescence is not an inherent property of the materials used, which had previously been suggested, but is dependent on the existence of some unidentified defect. Those chapters (i.e. six and seven) are essentially complete in themselves, including conclusions. In chapter eight, a brief, general summing-up is given, together with suggestions for some further work.

Transformation is a complex multistage process in vitro by which benign cells gradually acquire characteristics of tumour cells. Transformed C3H10T1/2 cells appear in vitro as multilayers of cells termed foci. Two main aspects of transformation of C3H10T1/2 cells in vitro have been investigated. Firstly, the quantitative assessment of the dose and dose-rate effects after irradiation with 250 kVp X-rays were examined and secondly the relationship between various properties of transformed cells in vitro and their tumourigenic potential in vivo. The induction of transformation was found to be linear with dose for 0.25 to 5 Gy X-rays. Lowering the rate at which the X-ray dose is delivered to the C3H10T1/2 cells lowers the observed transformation frequency by at least a factor of two. A variety of transformed phenotypes are observed in vitro and samples of these phenotypes were developed as cell lines and assessed for a number of properties. These properties were the ability to induce tumours in C3H mice and the ability to reconstruct foci in vitro. Other properties examined were growth in vitro parameters (lag time, doubling time and saturation density) as well as chromosome number and distribution. Tumour cell lines were also developed and assessed for the above properties. Transformation phenotypes induced by X-rays and alpha-particles were compared. Differences were found between some of the properties of the X-ray and alpha- particle induced transformants. In particular, higher proportions of X-ray induced transformants were tumourigenic while most of the alpha-particle induced transformants were non-tumourigenic and also tumours induced by the X-ray induced transformants appeared earlier and grew faster than the alpha-particle induced equivalent. The ability of the transformation phenotypes to reconstruct foci in vitro was greater for alpha-particle induced transformants (not including tumour cell lines) than for the X-ray induced transformants. The reverse was true for tumour cells where X-rays produced higher frequencies of reconstructed foci than alpha-particles. No differences were noted in in vitro growth parameters irrespective of transformation phenotype or radiation type apart from differences in saturation density where the transformation phenotypes (not including tumour cells) generally produced higher densities than the tumour cells for both X-rays and alpha-particles. Chromosome numbers in cells of the different transformation phenotypes (including tumour cells) induced by both X-rays and alpha-particles showed a greater spread and a general shift of the mean and modal chromosome number to lower values than that of untransformed C3H10T1/2 cells. The presence of metacentric chromosomes (Robertsonian chromosomes) was not unique to the radiation induced transformation phenotypes as most of the cell lines examined showed fewer of these chromosomes than the untransformed cells. The X-ray induced transformants (including tumour cells) generally produced more Robertsonian chromosomes than the alpha-particle equivalent. Correlation tests of the above properties with tumourigenicity of the transformed cells revealed a positive correlation of tumourigenicity with the ability to reconstruct foci. A negative correlation was noted between the ability to reconstruct foci and the mean and modal chromosome numbers.

The thesis describes and develops a new theoretical approach to the study of human cognitive processing performance in complex situations, so this approach utilises and integrates existing theoretical and empirical data from a number of traditionally separate areas of information processing psychology, such as cognition, perception, memory, imagery, skill and vigilance. Contemporary cognitive psychology considers perception, memory and imagery as functionally inter-related and inter-dependent processes characterised by active, constructive, conscious information processing. In the present thesis the implications of this view are extended, in that this processing is considered to occupy the cognitive processing capacity of the subject in qualitatively the same way as does normal decision-making, problem-solving, or conscious Internalised thought processing of any kind. The theoretical approach of the thesis stresses and accepts the functional inter-relationship and inter-dependence of the various higher mental processes, and is primarily concerned with the sustained dynamic performance properties of the total system. The nature of the research emphasis and direction of the thesis originates from the author's direct concern with applied problems resulting from the increasing cognitive load imposed upon human operators in present complex man-machine systems, such as jet aircraft, for example. Performance failure of the human operator in these systems often has very serious consequences. There is a critical lack of knowledge regarding the fundamental nature and limitations of human information processing in such situations. The basic motivation behind the work reported in the thesis was that, in order to study meaningfully the relevant aspects of the applied situation, further pure research, both theoretical and empirical, had to be undertaken to clarify particular issues. A new conceptual approach to vigilance-type situations is suggested by the theory developed in the thesis, A task was devised in which the signals to be detected were clearly visible, but embedded at random in complex visual patterns (photographs). These patterns were presented on a television screen at regular intervals, over 600 times to subjects during a single testing session. At each of these presentations subjects had to respond with respect to the identification of the picture shown; and to the presence or absence of a signal within it. From the theory it was predicted that where the complex pattern remained the same throughout the testing session, signal detection performance would show a typical vigilance decrement. However, when the set of possible pictures in which the signal may or may not be embedded is vastly increased, and the subject' has to respond at each event in the manner described, it was predicted that signal detection performance would be significantly improved in relation to the single picture condition. These predictions were empirically confirmed at a highly significant level. (On the basis of visual signal-to-noise ratios only, a signal detection analysis of the experimental situation would predict a result opposite to that actually obtained in the experiment). A computer simulation program based on fundamental theoretical ideas outlined in the thesis was developed. The program was used to simulate the vigilance experiment reported in the dissertation. The purpose and implications of the use of this technique as an applied research tool are discussed. The final chapter discusses the results achieved, and outlines the proposed application of the theoretical ideas, and empirical results of the research to the cognitive load problems of human operators in real man-machine systems, in particular aircrew flying advanced jet aircraft.

Syftet med den här studien var att kvalitativt undersöka L3-motivation hos vuxna invandrare som läser engelska (L3) på komvux i Sverige. Motivation undersöktes i relation till samspelet mellan målgruppens behov och mål, det svenska samhället och engelskans globala status. Den metodologiska utgångspunkten togs först och främst i Dörnyeis L2-motivationssjälvbildssystem (2005) och anpassades till studiens kulturella och sociala ramar. Resultaten indikerar att det är en stor sannolikhet att L3-motivation formas och starkt påverkas av vuxna invandrares invandrarskap och bikulturella identitet som har utvecklats i samband med integration i det svenska samhället. Detta framgår av att det svenska samhället och invandrarskapet ofta uppträder som normgivande när det gäller vuxna invandrares studier i engelska. Deras L3-motivationssjälvbildssystem indikerar dessutom att vuxna invandrares syn på den ideala språkliga självbilden är i kongruens med majoritetssamhällets förväntningar och kunskapsvillkor. Resultaten behöver dock valideras i framtiden genom fler studier och större elevpopulationer. / The purpose of this study is to by a qualitative method investigate L3 motivation in adult immigrants who study English (L3) in Sweden. Motivation was investigated in relation to the interplay between the target group’s needs and goals, the Swedish society, and the global status of English. The methodological framework was based on Dörnyei’s L2 Motivational Self System (2005) and it was adapted to the cultural and social context of the study. The results indicate that there is a probability that immigrant identity (Swe. invandrarskap) and a sort of bicultural identity, which have developed in adult immigrants as side effect in the integrational process in the Swedish society, shape and strongly affect L3-motivation. This is supported by the informants’ interview data in which the Swedish society and the immigrant identity often appear as a normative referent for adult immigrants’ English studies. In addition, their L3 motivational self system indicates that adult immigrants’ perception of the ideal language self is in congruity with the majority society’s expectations on knowledge. However, the results need to be validated through more studies and larger student populations in the future.

Humboldt-University, Diss., 2003--Berlin.

Techn. Hochsch., Diss., 1997--Aachen.

Techn. Hochsch., Diss., 2005--Aachen.

No description available.