The Catalytic Function of Ferrous Iron in Oxidations with Hydrogen Peroxide

The catalytic oxidation of substances by Hydrogen Peroxide in the presence of Ferrous Salts has been studied. It has been found that experimental evidence supports strongly the contention that the actual catalyst contains Iron in the Ferric state - probably of the nature of a Basic Ferric Salt. In this way is explained the failure of Normal Ferric Salts to catalyse such oxidations and the inhibiting action of low pHs brought about by the presence of mineral acids. The view has been advanced that catalysis is effected by the production of a highly oxygenated complex compound of Iron by the interaction of the Basic Ferric Salt noted above and Hydrogen Peroxide. The scheme suggested differs essentially from that which holds that oxidation is brought about by the reduction of Ferric Iron to the Ferrous state. It also negatives the views of Mummery who believes that only compounds containing Ferrous Iron are involved. In this respect also it differs from that of Kuchlin and Boeseken though not antagonistic to their idea that complexes with the substrate may play a part in such oxidations. The scheme advanced purports also to explain the reactions involved, though no information can be given as to the structure of the compounds taking part in the reactions. From these observations information has been gained as to the best method for the practical use of such systems

The profitability of progressive theology publishing in late nineteenth-century Scotland as illustrated by the experience of T. & T. Clark of Edinburgh in the 1880s and 1890s

This study assesses the profitability of one particular Scottish theological publishing firm, T. & T. Clark, in the 1880s and 1890s. Its major concern is to investigate the tension which exists in any 'committed' publishing business between the profit motive, and the desire to further the cause espoused by the firm. Did considerations of profitability significantly influence the theological stance of material issued? Or, in the interests of furthering a theological position, was the profit motive kept in second place as far as was consistent with the continuance of the firm? Or, in reality, was there a complicated interplay between these two positions? After a general survey which charts the history of the firm and attempts to assess the partners' motivation, there follows a highly detailed examination of the relative profitability of the different types and forms of publication handled by the Clarks: series publishing, translations, works of transatlantic origin, reference works requiring major investment, and general theological works. There follows an assessment of the cost-effectiveness of the firm's promotional strategy and distribution, and an examination of the profitability of the Clarks' operations as a whole for the four financial years beginning 1895-96. There are several appendices, one of which features a biographical study of Dr James Hastings, editor of the Dictionary of the Bible and the Encyclopaedia of Religion and Ethics. The conclusion is reached that there was indeed a complex interplay between motives spiritual and motives financial: the Clarks' decision to publish moderately 'advanced' theology was not primarily determined by financial considerations, but by their commitment to promulgating the truth as they saw it. This commitment was not opportunistic lip-service: they were frequently prepared to hazard investment on works of doubtful profitability because they considered them to be of theological value. However, the works they published were in general modestly if not spectacularly profitable, and the future growth of the business was assured. Had you put it to one of the principals that his firm seemed to be a living denial of Christ's asseveration that one cannot serve both God and mammon, he would probably have retorted that he was serving God and God alone, and that any financial success which accrued was to be interpreted as being a reward for faithful service.This study assesses the profitability of one particular Scottish theological publishing firm, T. & T. Clark, in the 1880s and 1890s. Its major concern is to investigate the tension which exists in any 'committed' publishing business between the profit motive, and the desire to further the cause espoused by the firm. Did considerations of profitability significantly influence the theological stance of material issued? Or, in the interests of furthering a theological position, was the profit motive kept in second place as far as was consistent with the continuance of the firm? Or, in reality, was there a complicated interplay between these two positions? After a general survey which charts the history of the firm and attempts to assess the partners' motivation, there follows a highly detailed examination of the relative profitability of the different types and forms of publication handled by the Clarks: series publishing, translations, works of transatlantic origin, reference works requiring major investment, and general theological works. There follows an assessment of the cost-effectiveness of the firm's promotional strategy and distribution, and an examination of the profitability of the Clarks' operations as a whole for the four financial years beginning 1895-96. There are several appendices, one of which features a biographical study of Dr James Hastings, editor of the Dictionary of the Bible and the Encyclopaedia of Religion and Ethics. The conclusion is reached that there was indeed a complex interplay between motives spiritual and motives financial: the Clarks' decision to publish moderately 'advanced' theology was not primarily determined by financial considerations, but by their commitment to promulgating the truth as they saw it. This commitment was not opportunistic lip-service: they were frequently prepared to hazard investment on works of doubtful profitability because they considered them to be of theological value. However, the works they published were in general modestly if not spectacularly profitable, and the future growth of the business was assured. Had you put it to one of the principals that his firm seemed to be a living denial of Christ's asseveration that one cannot serve both God and mammon, he would probably have retorted that he was serving God and God alone, and that any financial success which accrued was to be interpreted as being a reward for faithful service

The transition of smooth muscle cells from a contractile to a migratory, phagocytic phenotype : direct demonstration of phenotypic modulation

Atherosclerotic plaques are populated with smooth muscle cells (SMCs) and macrophages. SMCs are thought to accumulate in plaques because fully-differentiated, contractile SMCs reprogram into a ‘synthetic’ migratory phenotype, so-called phenotypic modulation, whilst plaque macrophages are thought to derive from blood-borne myeloid cells. Recently, these views have been challenged, with reports that SMC phenotypic modulation may not occur during vascular remodelling and that plaque macrophages may not be of haematopoietic origin. Following the fate of SMCs is complicated by the lack of specific markers for the migratory phenotype and direct demonstrations of phenotypic modulation are lacking. Therefore, we employed long-term, high-resolution, time-lapse microscopy to track the fate of unambiguously identified, fully-differentiated, contractile SMCs in response to the growth factors present in serum. Phenotypic modulation was clearly observed. The highly-elongated, contractile SMCs initially rounded up, for 1-3 days, before spreading outwards. Once spread, the SMCs became motile and displayed dynamic cell-cell communication behaviours. Significantly, they also displayed clear evidence of phagocytic activity. This macrophage-like behaviour was confirmed by their internalisation of 1µm fluorescent latex beads. However, migratory SMCs did not uptake acetylated low-density lipoprotein or express the classic macrophage marker CD68. These results directly demonstrate that SMCs may rapidly undergo phenotypic modulation and develop phagocytic capabilities. Resident SMCs may provide a potential source of macrophages in vascular remodelling

A large-scale analysis of the acoustic-phonetic markers of speaker sex.

The research for this thesis lies within the fieIa of speaker characterisation through the acoustic-phonetic analysis of speech. The thesis consists of two parts: 1. An inv.estigation of the acoustic-phonetic differences between the speech of women and men; 2. An examination of the practicalities of automating the investigation to analyse a large speech database. The acoustic-phonetic markers of speaker sex examined here are the fundamental frequency, the formant frequencies, and the relative amplitude of the first harmonic. The aims of the investigation were, firstly, to establish to what extent these markers differentiate between the sexes, and secondly, to examine the extent of between- and within-speaker deviation from the female and male norms, or average values for each sex. These points were investigated by an automated acoustic-phonetic analysis of the TIMIT database, involving a data set of almost 16,000 segments of speech. An automated method was dev~loped to enable the signal processing and statistical analysis of a data set of this size. The problems to be encountered in the analysis of a highly variable data source (i.e. the acoustic speech waveform) are addressed

The Ages and Abundances of the M87 Globular Clusters

A subset of 150 globular clusters in M87 has been selected on the basis of S/N ratio for abundance and age determinations from the sample of Paper I. Indices measuring the strength of the strongest spectral features were determined for the M87 GCs and from new data for twelve galactic GCs. Combining the new and existing data for the galactic GCs and comparing the $(U-R)$ colors and the line indices gives qualitative indications for the ages and abundances of the GCs. Quantitative results are obtained by applying the Worthey (1994) models for the integrated light of stellar systems of a single age, calibrated by observations of galactic GCs, to deduce abundances and ages for the objects in our sample. We find that the M87 GCs span a wide range in metallicity, from very metal poor to somewhat above solar metallicity. The mean [Fe/H] of -0.95 dex is higher than that of the galactic GC system, and there is a metal rich tail that reaches to higher [Fe/H] than one finds among the galactic GCs. The mean metallicity of the M87 GC system is about a factor of four lower than that of the M87 stellar halo at a fixed projected radius $R$. The metallicity inferred from the X-ray studies is similar to that of the M87 stellar halo, not to that of GCs. We infer the relative abundances of Na, Mg, and Fe in the M87 GCs from the strength of their spectral features. The behavior of these elements between the metal rich and metal poor M87 GCs is similar to that shown by the galactic GCs and by halo stars in the Galaxy. The pattern of chemical evolution in these disparate old stellar systems is indistinguishable. We obtain a median age for the M87 GC system of 13 Gyr, similar to that of the galactic GCs, with a small dispersion about this value.Comment: 56 pages with included postscript figures; added derived M87 GC metallicities to Table 2, a statistical analysis of possible bimodality, an appendix on the metallicity calibration of U-R and the Washington system, and other smaller changes. Accepted for publication in ApJ. (See paper for complete version of the Abstract.

Quantification of global mitochondrial DNA methylation levels and inverse correlation with age at two CpG sites

Mammalian ageing features biological attrition evident at cellular, genetic and epigenetic levels. Mutation of mitochondrial DNA, and nuclear DNA methylation changes are well established correlates of ageing. The methylation of mitochondrial DNA (mtDNA) is a new and incompletely described phenomenon with unknown biological control and significance. Here we describe the bisulphite sequencing of mtDNA from 82 individuals aged 18-91 years. We detected low and variable levels of mtDNA methylation at 54 of 133 CpG sites interrogated. Regression analysis of methylation levels at two CpG sites (M1215 and M1313) located within the 12S ribosomal RNA gene showed an inverse correlation with subject age suggesting their utility as epigenetic markers of ageing

Mechanoenzymatic reactions with whole cell transaminases: shaken, not stirred

Mechanochemical reactions have emerged in recent years as a green synthetic method because reactions can be performed more rapidly and using less solvent than traditional synthetic approaches. To date, very few mechanoenzymatic reactions have been described. For the first time, transaminases, which are widely used for the amination of aldehydes and ketones, have been used here under mechanoenzymatic conditions to produce amines using significantly less aqueous medium than conventional biocatalytic reactions. The direct use of whole cells was also possible and shorter reaction times could be used to provide amines efficiently with high yields and stereoselectivities