VictorJuiz/thesis huggingface dataset:
Reactions of iron-sulfur clusters in proteins

This thesis describes the investigation of reactions of iron-sulfur clusters in proteins using direct electrochemistry. The influence of potential on metal uptake to generate the [M3Fe-4S] cluster from the [3Fe-4S] cluster of Desulfovibrio africanus Fd III is studied. The influence of potential was complex: rapid and reversible interconversions (M = Fe and Zn) occurred only between the states [M3Fe-4S]2+ and [3Fe-4S]0, with [3Fe-4S]1+ having little affinity for M. The [M3Fe-4S]1+ cubanes and the hyper-reduced [3Fe-4S]2- were relatively unreactive.
The reactivity of the transformed cluster, [M3Fe-4S] (M = Fe, Zn, Co), from the 7Fe Fd of Desulfovibrio africanus was studied and was found to react with a number of small thiol molecules, indicating that either ligand addition or exchange takes place at the transformed M site of the cluster. No reaction was observed with oxygenic ligands. In all cases, with the exception of imidazole, negative shifts in reduction potentials were observed.
Reactions of the [2Fe-2S] cluster from the ferredoxin of Clostridium pasteurianum and a number of site-directed mutants of this ferredoxin are studied. The cysteine ligands of the cluster were identified and evidence was obtained for serinate ligation of the cluster in a number of mutants. The reduction potentials of these serinateligated clusters were found to have a notable dependence on pH. A mutant ferredoxin containing only three cysteine ligands was investigated, which was found to interact with an exogenous thiolate ligand and, in addition, displayed a second reduction couple, indicating the formation of the [2Fe-2S]0 state.
Reactions of the [3Fe-4S] cluster and various [M3Fe-4S] adducts, from the ferredoxin of the hyperthermophile Pyrococcus furiosus, are studied. The [3Fe-4S] cluster exhibited a complex pH dependence over a wide pH range. The formation of the hyper-reduced [3Fe-4S]2- state was observed, which required 3H+ for the overall 3e‧ reduction from [3Fe-4S]1+. Metal uptake reactions for M = Fe, Zn, Cd, were found to be slower than for its mesophilic counterpart, the 7Fe Fd III from Desulfovibrio africanus. Conversely, Tl uptake was found to be rapid, suggesting that co-ordination of Tl does not require reorganisation of the protein structure.
Neoplatonism and French religious thought in the seventeenth century

This thesis is a heuristic and argumentative study of the significance of Neoplatonism in the religious thought of the French Catholic revival of the seventeenth century. Taking the broad corpus of Neoplatonic thought - classical, patristic, mediaeval and, especially, that of the Florentine Renaissance - as its starting-point, it deals briefly with the reception and exploitation of Neoplatonic ideas by the French Humanists, before proceeding to consider the seminal influence of the cercle Acarie in the late sixteenth century. It is in this spiritual group of distinctly mystical bent that we discern the beginnings of a profound movement of religious thought greatly inspired by Neoplatonism, with its ultimate origins in the years predating the Reformation, and which continued to play an important part in seventeenth-century philosophy and theology. This Neoplatonic movement is exemplified by the Order of Capuchins and the Congregation de l'Oratoire, and the main part of the thesis concerns these two religious groups in which the continuity, consistency and, indeed, inescapability of the Neoplatonic tradition are readily apparent. Amongst the Capuchins, the development away from abstract mysticism towards more Humanistic apologetics directly influenced by the Florentines is charted. With regard to the Oratoire, we have attempted to illustrate and demonstrate its pervasive spirit established by its founder and the nature of the Neoplatonism of its members whose fundamental thought and spirituality were informed by Dionysian mysticism and Augustino-Platonic idealism; the problems raised by the thought of Descartes are also considered in our survey of later Oratorians. The final three chapters are devoted to Malebranche, Bossuet and Fenelon, respectively, three major thinkers of the seventeenth century who embody the philosophical, the Humanistic or apologetic and the mystical strains of Neoplatonism that we have identified and which we believe are essential to the Catholic reform of the late sixteenth and seventeenth centuries.
Scanning tunneling microscopy of electrode surfaces

A scanning tunneling microscope (STM) suitable for the in-situ study of electrode surfaces under electrochemical control has been developed. The system consists of commercially available software and feedback electronics, with a custom-built stage and electrochemical control. The stage incorporates an automatic coarse approach mechanism for ease of operation.
Gold single crystal spheres (SCS) and gold on mica thin films have been studied as surfaces potentially suitable for samples in in-situ electrochemical STM experiments. Characteristic features of each surface have been identified.
High resolution in-situ STM imaging of the electro-oxidation of a gold surface in a sulphuric acid electrolyte has been achieved. Surface rearrangement at potentials positive of the double layer region has been observed and correlated with cyclic voltammetry. As yet unexplained features resulting from biasing the surface at potentials negative of the double layer region are reported. In phosphate electrolyte, bulk surface oxide formation and the surface resulting from reduction of the oxide have been imaged.
Some aspects of the direct electrochemistry of cytochrome c at 4,4' dithiodipyridine (SSBPY) modified gold electrodes have been investigated. In-situ FTIR showed the potential dependent orientation of adsorbed thiopyridine species, while ex-situ and in-situ STM studies showed a novel surface pitting process to be active. It is hypothesised the STM experiment itself induces the process to take place. Features attributable to cytochrome c molecules have been observed.
Rearrangement of gold on mica surfaces, on exposure to certain aqueous solutions has been observed and the process is attributed to the interaction of the solutions with the original surface structure present.
The production of point defects in solids by radiation

A number of different aspects of Frenkel defect production are discussed in this thesis. Experiments have been performed to characterise the response of sapphire to radiation and to determine the stability, with respect to temperature and subsequent ionising radiation, of the oxygen vacancies produced. The displacement threshold of the aluminium ion has been determined by irradiating with electrons and comparing measured concentrations of the V centre with theoretical values, and evidence is presented for the stability of the F2+ centre at liquid helium temperatures. The efficiency of point defect production in sapphire by a variety of ion beams has been estimated by monitoring the oxygen vacancy colour centre concentration. Results are presented for H, D, He, B, N, Ne, Ar and Kr bombardment at both room temperature and 77K. Experimentally determined values of the mean number of oxygen vacancies produced per incident ion are compared with theoretical values. The latter have been computed by solving the Lindhard integral equations to determine the partitioning of energy between the oxygen and aluminium sublattices. The stopping powers and cross sections of Ziegler, Biersack and Littmark have been used in these calculations and give significantly improved estimates of the damage energy. Two main points emerge from this study. Firstly, a significant Z1 variation of the damage efficiency is noted for low mass ions. Secondly, in contrast to metals (in particular aluminium) no reduction in efficiency has been found in sapphire with increasing ion mass. This is attributed to differences in the 'thermal spike' behaviour, as a consequence of differing thermodynamic properties, between aluminium and its oxide. The implications of both these results for irradiation characterisation are discussed. In the final chapter we discuss the interaction between conduction electrons and ions in the cooling phase of cascades in metals. Differential equations governing the transfer of heat between the two systems are derived and solved numerically, using physically reasonable parameters for cascades in copper and nickel. Large differences are found in the cooling rates of cascades in these two metals. The degree of cooling due to electronic heat transport is shown to depend on the ratio of a parameter T0, the temperature at which the electron-phonon mean free path reduces to the radius of the Wigner-Seitz sphere, and γe, the coefficient of the electronic heat capacity. The participation of the electronic system in cascade evolution is shown to preclude a universal description of damage efficiency on the basis of simple atomic scaling laws.
Coleridge : the aesthetics of the fragmentary and the romantic imagination

Recent work on the fragment, prompted in part by the disruption of totalities in contemporary theories of writing and textuality, has returned the fragment to legitimacy in literary studies. Literary critics have begun to hail the fragment as the quintessential Romantic "form"-- one which, as D.F. Rauber claims, embodies Romantic ideals and aims more fully than any other. The fragment (in unmistakably high Romantic terms) is said to figure forth the infinite and the indeterminate in a finite, discrete, sequential medium--engaging, furthermore, in an organicist relation with the whole of which it partakes. The fragment, like the symbol or the organic part, is thought to be capable of indicating or implying the absent whole. By identifying itself with the organic part (or being so identified by readers), the fragment even usurps the ideal place of the whole by offering access to its essential nature--access that is, ironically, less materially compromised by the possibility of fragmentation than if it had become a complete whole. In this way the fragment comes to be seen as the most appropriate signifier of sublime, visionary excess--as the best possible representation of the impossibly ambitious work that the mind aspires to but is unable to sustain or carry out.
This study examines the problem of the fragment in Romantic literature and poetic theory, and investigates the reconstruction of "Romanticism" through the phenomenon of the fragment in contemporary literary criticism. The Romantic canon is highly susceptible to reconstruction along "fragmentary" lines since so many of its central texts are fragments in at least one sense. In spite of the broad nature of the problem (a pervasive aesthetic and epistemological difficulty), this study brings two specific areas (romantic aesthetics and current literary criticism) to bear on three major, fragmentary, Coleridge texts: Biographia Literaria, "Kubla Khan," and "Christabel." In each case, arguments are made for or against the "unity" of the work. For Biographia Literaria, these turn on the viability of Coleridge's theory of imagination; in "Kubla Khan," on the relation of the preface to the poem; and in "Christabel," on its truncated two-part structure.
Heine and the Victorians

This thesis considers the reception of Heine in Victorian Britain and charts, through the medium of periodical articles in particular, the general development in British attitudes towards him, from the bewildered hostility of the 1830's through to the sentimental eulogising which is frequently found in articles written after his death. Unquestionably the most important articles written on Heine in nineteenth-century Britain were by George Eliot and Matthew Arnold. The aims and achievements of these authors, in writing on Heine, were very different, but both produced articles of enduring significance, and together they had a strong influence on the general improvement in Heine's fortunes in Britain during the second half of the nineteenth century. In turn, Heine was of importance not only for George Eliot and Matthew Arnold but also for some of the lesser figures of Victorian literature, notably Richard Monckton Milnes (Lord Houghton), Julian Fane and the Lyttons. All of these played some part in promoting Heine's reputation in Britain, and in this role Milnes enjoyed the help of Lucie Duff Gordon, one of the closest of Heine's English friends. Heine exerted a relatively small but definite influence on the creative works of both George Eliot and Matthew Arnold and on the poems of Milnes. In the case of Matthew Arnold, however, those critics who have considered Heine's influence in any depth have tended also to exaggerate it beyond reasonable bounds.
Wrestling with angels : a study of the relationship between angels and humans in late Second Temple Judaism and early Christianity

Much of the extant literature from the kte Second Temple and early Christian periods (200BCE 100CE) contains material about angels. This dissertation is an investigation into the understanding during this period of the relationship between angels and humans. It serves two purposes: (1) it contributes to our understanding of ideas about angels in this period by surveying all of the available evidence and considering evidence that has not previously been studied in detail, and (2) it concludes, contrary to recent studies by Fletcher- Louis and Gieschen, that a clear distinction was maintained between angels and humans, despite occasions when this gap is bridged and humans do become angels.
The first chapter introduces the subject, surveys previous research showing the need for the present study and sets out the historical context of the literature to be examined. After these preliminary considerations, the evidence for the distinction between angels and humans is examined in two parts:
Part one consists of two chapters that investigate the issue of the similarity of appearance between humans and angels. Chapter two examines the evidence for the portrayal of angels as human beings; conversely, chapter three examines the evidence for the portrayal of humans being as angels.
Part two consists of three chapters that investigate the portrayal of close contact between humans and angels. Chapter four examines texts that describe humans and angels living together in communities. Chapter five considers texts that portray angels as recipients of human hospitality, including the issue of whether or not angels ate food. Chapter six considers the human-angel hybrid offspring of Genesis 6 and its interpretations.
The final chapter summarises the conclusions that are drawn from the evidence and outlines their implications for current scholarship.
The perfect gentleman : the representation of men in the English gothic novel, 1762-1820

This thesis examines the representation of male character stereotypes as manifestations of a formula in late eighteenth-century popular fiction. In order to establish the presence of the formula, I have inspected a wide spectrum of both familiar and lesser-known works. Much recent criticism has focused on the passive figure of the heroine as one expression of female anxiety within the texts. In contrast, this thesis draws attention to the critically unseen, active figures surrounding her threatened perfection, by establishing, first, a common representation or role within the formula for each stock character and, second, the source and possible effect of these stereotypes.
In Chapters One and Two, the parameters for this approach are set up and the influences of other genres on characterization in the Gothic romance are considered. Chapter Three establishes the eighteenth-century ideal of masculinity through an investigation of contemporary conduct literature. These standards are then applied to stock male figures in succeeding chapters.
Chapters Four, Five and Six consider the primary male figures of hero, father and villain, revealing that the ideal of masculine perfection affects all these stereotypes. The nature of heroism is questioned in the person of the hero; the father - an exemplum of gentlemanly perfection - is made absent within the text; and the villain reinforces this ideal by perverting it.
Chapter Seven considers the representation of the victim figure and the way in which the stereotype of masculinity indirectly victimizes male figures.
In Chapter Eight, three groups of secondary male characters are considered and their relationship to the primary male characters examined.
This analysis of male stereotypes has, therefore, provided one approach to an understanding of Gothic conventions.
Problems of perception and representation in the novels of Claude Simon

My main argument is that Simon's association with the Nouveau Roman springs not simply from a reaction against tradition, but more importantly from a positive, personal interest in the relationship between perception and representation. Simon's theory of defamiliarization and his interest in the cultural code and its influence on perception provide a possible solution to the apparent inconsistency between his notations of sensory impression and his subversion of traditional 'realistic' definitions of representation. Indeed, Simon's development can be viewed partly in terms of a shift in interest from the defamiliarization of our perception of the world to a defamiliarization of hitherto 'invisible' literary techniques and of the relationship between language and reality.
The introduction of the thesis correlates Simon's various scattered literary statements and tries to establish the coherence of his theoretical principles. Chapter one charts the shift in Simon's fiction from behavioural and moral questions to questions relating to the psychology and philosophy of perception, including the relationship between perception and the code. Chapter two illustrates Simon's rejection of the primacy of the Realist code and his exploitation, in the generation of a text, of the multiple associations of the gamut of linguistic and cultural codes into which the writer is born. The final chapter tries to effect a synthesis and considers both the perceptual and representational aspects of time and history.
While the thesis situates Simon in the context of recent psychological and linguistic theory, it does not posit conclusive links with any one school. Contemporary theory simply offers a set of co-ordinates by which to gauge Simon's evolution and openness to prevalent ideas. In the end, however, my principal concern remains the specificity and intrinsic coherence of his development.
Gas propulsion of microprojectiles for the transformation of biological cells

Bombardment of intact cells and tissue with DNA-coated microprojectiles represents a novel approach to the genetic transformation of biological material. In this thesis, a gas propulsion particle gun is developed for such a purpose. The particle gun utilises gas dynamics to control particle velocity and spread, thereby enabling optimisation of transformation efficiencies for varying types of target material. The dynamics associated with particle acceleration are shown to relate to transient, shock tube flow.
Measurements from schlieren high-speed video photographs of the shock structure of an underexpanded jet demonstrate good agreement with empirical correlations of previous researchers; pitot tube measurements of the nozzle exit Mach number are made and shown to be in good agreement with theoretical contact surface velocities.
A novel optical particle velocimeter is used to measure particle time-offlight between axial locations in the system's target chamber, providing a consistent, distance-averaged measurement of particle velocities. Particle velocities are measured for a range of system pressure ratios and driver gases. Variation in particle velocities is seen to be similar to theoretical variation in contact surface velocities. Analytical theory is used to predict small gas-particle velocity lag. Particle velocities with helium as a driver gas are shown to be considerably higher than those with air.
High speed video recording of chalk particles exiting the nozzle is used to visualise the spatial and temporal variation in particle spread as a function of nozzle pressure ratio. This technique demonstrates that particle spread increases with increasing nozzle pressure ratio, as gas dynamics theory indicates.
Conditions for bombardment of maize suspension cells are experimentally optimised. Significant rates of transient genetic expression are achieved with both air and helium as driver gases. High levels of transient genetic expression are also found with bombardment of maize coleoptiles and the leaves of various dicot species.
Transformation efficiencies for bombardment of HL60 human leukaemia cells show dramatic increases over efficiencies seen with conventional techniques not involving cell bombardment. For other cell types the gas propulsion device described here appears to give rates of transient genetic expression similar to those reported for commercial systems using microprojectiles. Other data for the performance of such systems are too limited at present to allow comparisons of controllability and reproducibility of bombardment efficiency.
Inelastic neutron scattering by adsorbed molecules and catalysts

The possibilities of applying cold neutron scattering to the study of sorbed molecules are discussed. Atom-atom pair calculations have been carried out for the interaction of methane and hydrogen molecules with the basal plane of graphite and the results used as a guide to the best scattering law for the sorbed molecule dynamics. As the sorbents used are powders, a method of averaging the two dimensional scattering law over three dimensions has been developed.
Neutron time of flight spectra were obtained for methane, ethylene and ammonia adsorbed on Graphon. For the surface coverages studied, 0.6-0.2, methane appears to change from a two dimensional Fickian liquid, to an unidentified phase at the lower surface coverage. The data for ethylene at around one monolayer approaches the two dimensional liquid model, but at higher surface coverages there are significant deviations.
Whilst methane and ethylene appear to wet the Graphon surface, ammonia does not seem to do so. The spectra for ammonia show a liquid phase characterised by a diffusion coefficient and activation energy for diffusion, 2.4 kcals/mole, close to those measured for bulk ammonia A solid phase is observed at lower temperatures.
Neutron time of flight spectra were obtained for methane absorbed in a lanthanum exchanged Y type zeolite. The spectra show that the methane has lost translational motion but retained rotational freedom. A vibration frequency of 19±1 cm-1 is observed and this is ascribed to a vibration of the methane molecule within the cavity.
The sorption of simple molecules on catalytically active surfaces was investigated by beryllium filter spectroscopy. A range of interactions was discovered, varying from the gas like sorption of hydrogen and methane on La-Y, to the dissociative sorption of formic acid on γ alumina. Intermediate behaviour was observed when dichloromethane and acetonitrile were sorbed on La-Y.