Showing papers by "University of Leicester published in 1980"

Lectures on public economics

Abstract: This classic introduction to public finance remains the best advanced-level textbook on the subject ever written. First published in 1980, Lectures on Public Economics still tops reading lists at many leading universities despite the fact that the book has been out of print for years. This new edition makes it readily available again to a new generation of students and practitioners in public economics. The lectures presented here examine the behavioral responses of households and firms to tax changes. Topics include the effects of taxation on labor supply, savings, risk-taking, the firm, debt, and economic growth. The book then delves into normative questions such as the design of tax systems, optimal taxation, public sector pricing, and public goods, including local public goods. Written by two of the world's preeminent economists, this edition of Lectures on Public Economics features a new introduction by Anthony Atkinson and Joseph Stiglitz that discusses the latest developments in the field and areas for future research. * The definitive advanced-level textbook on public economics * Examines the effects of taxation on households and firms * Covers tax system design, optimal taxation, public sector pricing, and more * Includes suggestions for further reading * Additional resources available online

Lipids in the Classification and Identification of Coryneform Bacteria Containing Peptidoglycans Based on 2, 4-diaminobutyric Acid

Abstract: Strains of 2, 4-diaminobutyric acid-containing coryneform bacteria were degraded by acid methanolysis and the non-hydroxylated fatty acid esters released examined by thin-layer and gas chromatography. The major fatty acid structural types were straight-chain, anteiso- and iso-methyl branched-chain acids. Polar lipids of the test strains were examined by two-dimensional thin-layer chromatography. All strains possessed very characteristic polar lipid patterns consisting of diphosphatidylglycerol, phosphatidylglycerol and a number of uncharacterized glycolipids. Menaquinones (vitamin K) were the sole isoprenoid quinones detected in the test strains. Corynebacterium insidiosum, Cor. michiganense, Cor. nebraskense and Cor. sepedonicum contained unsaturated menaquinones with nine isoprene units, whereas unsaturated menaquinones with 10 isoprene units predominated in strains of Cor. iranicum and Cor. tritici and a strain labelled Arthrobacter sp. The single strain of Cor. aquaticum examined contained comparable amounts of menaquinones with 10 and 11 isoprene units whereas strains of Cor. mediolanum and Flavobacterium dehydrogenans contained major amounts of menaquinones with 11 and 12 isoprene units. The results of the present study indicate that lipid markers may be of considerable value in the classification and identification of 2, 4-diaminobutyric acid-containing phytopathogenic and saprophytic coryneform bacteria.

Carbonic metamorphism, granulites and crustal growth

Abstract: Stabilization of early crust against melting by high radioactivity and against resorption into the mantle by fast convective overturn requires that water and heat producers were flushed upwards within 50 Myr of accretion. Creation of a refractory base of granulite by metamorphism associated with CO2 vapour explains CO2-rich fluid inclusions in ancient high-grade rocks, minor-element depletions and local phenomena of arrested development of charnockite in Precambrian terrains. The hot-spot and plate-tectonic models of Precambrian crustal evolution lead to different schemes for CO2 delivery to continental roots. New tectonic concepts may be needed to explain carbonic metamorphism and other features of early crustal evolution.

The Fitting of Exponential, Weibull and Extreme Value Distributions to Complex Censored Survival Data using GLIM

Abstract: SUMMARY Regression models may be fitted to censored survival data by the use of exponential, Weibull and extreme value distributions in GLIM. Standard probability plotting procedures for uncensored data may be modified to allow for censoring. A simultaneous test procedure may be used to determine a minimal adequate regression model. The procedure is briefly illustrated on two sets of published cancer survival data. A RECENT paper by Kay (1977) surveys methods for the analysis of censored survival data. Kay considers the fitting of exponential and Weibull models, and Cox's distribution-free model, the assessment of the form of the survival distribution through residual plots, and the determination of relevant variables in the regression of the hazard function on explanatory variables. The purpose of the present paper is to describe the use of GLIM (Baker and Nelder, 1978) to fit exponential, Weibull or extreme value distributions, by expressing the likelihood in each case as a Poisson likelihood, with a log-linear model for the Poisson mean corresponding to the log- linear model for the hazard function. A simultaneous test procedure developed for complex cross-classifications may be applied to the reduction of the complex regression model to a parsimonious form. The procedure is illustrated on two-sample data published by Gehan (1965), and on complex data published by Prentice (1973).

Measuring metamorphic history of unequilibrated ordinary chondrites

Abstract: Measurements performed by a thermoluminescence sensitivity technique of the degree of metamorphism experienced by unequilibrated ordinary chondrites are reported. Samples of type 3 chondrites were ground and heated to 500 C to remove their natural thermoluminescence, then irradiated with either 50 krad from a Co-60 gamma ray source or 25 krad from a Sr-90 beta source. The resulting thermoluminescence measured as a function of temperature is found to differ as much among some type 3 chondrites as between type 3 and other types, leading to the proposal of scheme for subdividing type 3 ordinary chondrites based on their thermoluminescence sensitivity.

Improved conversion of methanol to single-cell protein by Methylophilus methylotrophus

Abstract: The glutamate dehydrogenase gene of Escherichia coli has been cloned into broad host-range plasmids and can complement glutamate synthase mutants of Methylophilus methylotrophus. Assimilation of ammonia via glutamate dehydrogenase is more energy-efficient than via glutamate synthase, thus the recombinant organism converts more growth substrate, methanol, into cellular carbon.

ColV Plasmid-Mediated, Colicin V-Independent Iron Uptake System of Invasive Strains of Escherichia coli

Abstract: Evidence is presented that ColV plasmid-mediated iron uptake, an important component of the virulence of invasive strains of Escherichia coli, is independent of colicin V synthesis and activity. A mutant of E. coli K-12 deficient in the biosynthesis of enterochelin (strain AN1937) was unable to grow on minimal agar containing the chelating agent α,α′-dipyridyl unless it was harboring the plasmid ColV-K30 (strain LG1315). Acquisition of the active plasmid-specified iron sequestering system was accompanied by marked enhancement of pathogenicity in experimental infections of mice. Mutants of strain LG1315 were isolated that were defective in iron uptake due to plasmid mutations. They were unchanged with respect to colicin production, but were significantly less virulent than the parent strain. Conversely, mutants isolated as defective in colicin V synthesis were normal for the plasmid-coded iron uptake mechanism and showed the same lethality for infected mice as did strain LG1315. Furthermore, mutations in strain AN1937 which render it resistant or tolerant to the bactericidal action of colicin V did not influence the uptake of iron into plasmid-carrying strains. Cross-feeding tests involving plasmid mutants defective in iron uptake identified two plasmid-specified components of the system, an extracellular iron-chelating compound and a nondiffusible product allowing transport of iron across the bacterial cell membrane.

A simple system for the presumptive identification of Candida Albicans and differentiation of strains within the species

Abstract: A system of 10 agar plate tests allowed presumptive identification of Candida albicans and differentiation of up to 512 strain types within the species. The yeast isolates were tested for acid and salt tolerance, proteinase production, resistance to 5-fluorocytosine and safranine, and assimilation of urea, sorbose, citrate and glycine. Media were inoculated semiquantitatively with a multiple-pronged device so that 55 yeasts and 5 reference strains could be printed on each plate at once. The results for the 9 strain differentiation tests were arranged in 3 groups to allow simple designation of types by 3-digit numbers. Mouth and vaginal samples from 85 patients and healthy volunteers yielded 45 different strain types, of which types 153, 157 and 357 were the most prevalent. The reproducibility of the system was good, if attention was paid to the precision with which the media were prepared and inoculated. The effect of test variables, including incubation temperature, medium pH and inoculum size, was asses...

Conservative management of finger tip injuries in adults

Abstract: A prospective trial was undertaken on fifty consecutive patients with a total of sixty finger tip injuries treated by conservative means at the Leicester Royal Infirmary Accident and Emergency Department. The injuries have been classified into groups and results reviewed after a period of one year.

A Note on the Separation of Natural Mixtures of Bacterial Menaquinones using Reverse Phase Thin-layer Chromatography

Abstract: Natural mixtures of bacterial menaquinones were separated according to the length and degree of saturation of the polyisoprenyl side-chain using ready made Merck RP-18F254 reverse phase thin-layer chromatography plates. The system described affords a simple and rapid means of menaquinone characterization.

A critical reassessment of inferred relations between multiple authorship, scientific collaboration, the production of papers and their acceptance for publication

Abstract: There have recently been completed a number of studies which analyse and interpret trends in multiple authorship for scientific papers. This paper presents data which show that a significant relationship exists between levels of multiple authorship for papers submitted to a leading Astronomy journal, and their frequency of acceptance for publication. It is argued that this finding indicates the need for the exercise of more extensive qualification when drawing inferences about actual social aspects of research activity, from trends in the multiple authorship of published papers.

Rapid photomodulation of stem extension in light-grownSinapis alba L. : Studies on kinetics, site of perception and photoreceptor.

Abstract: Treatment of the whole of aSinapis alba plant with supplementary far-red light (FR), in back-ground white light (WL), induces a rapid increase in stem extension rate. This rapid increase is regulated by the light environment of the stem itself. Supplementary FR to the stem increases extension rate after a lag period of 10–15 min. A lag period of 3–4 h follows FR irradiation of the leaf, before an increase in extension rate is detectable. When the stem is given supplementary FR, the change in extension rate which is induced increases with increasing FR fluence rate, and with decreasing phytochrome photoequilibrium. There is no difference between the effects of supplementary FR λmax 719 nm and supplementary FR λmax 739 nm for these relationships. The increase in extension rate induced by supplementary FR is reversed by an increase in the fluence rate of red light (R). These data indicate that the response is controlled by phytochrome photoequilibrium.

Fatty acid and isoprenoid quinone composition in the classification of Bacteroides melaninogenicus and related taxa.

Abstract: The fatty acid and isoprenoid quinone composition of 37 Bacteroides strains was examined. In a single strain of Bacteroides melaninogenicus subsp. levii neither menaquinones nor ubiquinones was detected. Menaquinones were the only isoprenoid quinones found in the remaining 36 Bacteroides strains examined. Unsaturated menaquinones with six isoprene units were the main components isolated from B. ochraceus. The menaquinone components of B. asaccharolyticus strains enable them to be divided into two subgroups containing menaquinones with nine and ten isoprene units respectively. Bacteroides vulgatus strains contained menaquinones with ten isoprene units as the major component, whereas B. fragilis, B. thetaiotaomicron and B. melaninogenicus subsp. melaninogenicus were characterized by comparable amounts of menaquinones with 10 and 11 isoprene units. Unsaturated menaquinones with 11 isoprene units were found in B. melaninogenicus subsp. intermedius and with 11 and 12 isoprene units in rumen strains of B. ruminicola subsp. brevis and B. ruminicola subsp. ruminicola. By contrast, oral strains of B. ruminicola subsp. brevis were characterized by major amounts of menaquinones with 12 and 13 isoprene units. Strains at present designated B. oralis, however, were heterogeneous with respect to menaquinone composition. The non-hydroxylated fatty acids of all the Bacteroides strains examined consisted predominantly of straight-chain, anteiso- and iso-methyl branched-chain acids. Monounsaturated fatty acids were found in only small amounts. The major fatty acid in B. ochraceus and B. asaccharolyticus strains was 13-methyltetradecanoic acid (iso C15) whereas 12-methyl-tetradecanoic acid (anteiso C15) predominated in B. melaninogenicus subsp. melaninogenicus. B. melaninogenicus subsp. intermedius. B. melaninogenicus subsp. levii, B. oralis and oral isolates of B. ruminicola subsp, brevis. The rumen strains of B. ruminicola subsp. brevis and B. ruminicola subsp. ruminicola were characterized by major amounts of anteiso C15 and pentadecanoic (C15:0) fatty acids. The accumulated lipid data correlate well with the major trends in Bacteroides taxonomy and appear to be of value in the classification of this group.

Selective Elemental Depletion During Metamorphism of Archaean Granulites, Scourie, NW Scotland

Abstract: The low abundances of large ion lithophile elements (LIL), K, Rb, U, Th, Cs, and high K/Rb ratio in rocks varying in composition from gabbro to granite in the Scourian complex, NW Scotland, are interpreted as due to depletion during granulite facies metamorphism. Depletion was controlled by the mineralogy of the rock, the composition of the associated fluid phase and its volume relative to the volume of the rock. K-feldspar granites and granodiorites were not depleted in K and only moderately in Rb, but tonalites and trondhjemites were strongly depleted in both K and Rb. Published mineral-fluid partition coefficients for LIL in aqueous systems indicate that between 0.075 and 2.0 rock volumes of fluid phase passed through the host rock in order to achieve the observed selective elemental depletion.

Isotopic and trace element evidence for submarine lithification of hardgrounds in the Jurassic of eastern England

Abstract: Geochemical and petrographic data suggest early submarine cementation of hardgrounds from the Lincolnshire Limestone Formation, Middle Jurassic, England. The three hardgrounds, from Cowthick, Castle Bytham and Leadenham quarries, developed in tidal-inlet, on-barrier and lagoonal sub-environments of a carbonate barrier-island complex. At Cowthick early composite (acicular-bladed) radial-fibrous cements, which pre-date aragonite dissolution, completely fill intergranular pore-space at the hardground surface; away from it isopachous fringing cements decrease in thickness. Microprobe analyses demonstrate zoning within the fringes with magnesium concentrations (> 2 wt % MgCO3) higher than those in allochems or later, ferroan cement (≅0.5 wt % MgCO3, 1.7 wt % FeCO3). At Castle Bytham early granular isopachous cements, which post-date aragonite dissolution, occur within 5 cm of the surface. At Leadenham early lithification is superficial and represented by ferruginous crusts and micritic internal sediment. Late blocky cement fills residual pore-space in all three examples. Carbon and oxygen isotopic composition of whole-rock samples taken at intervals away from each hardground surface demonstrate the increasing proportion of late 18O depleted cements (δ18O – 8 to – 10). Early cements must have a marine isotopic composition; different δ18O values from each hardground reflect the intensity of early lithification and exclusion of late cements at the hardened surface. There is no isotopic evidence for subaerial cement precipitation during possible emergence at Castle Bytham. Oyster samples (with δ18O, – 2.9 and δ13C, 2.4) give estimated palaeotemperatures of 22–25°C. Early cements from Cowthick are enriched in 18O and 13C (δ18O = 0 δ13C ≅ 3‰) compared to the oyster values. In conjunction with trace element data this is interpreted as evidence for high-magnesium calcite precursor cements which underwent replacement in a system with a low water: rock ratio. The intensity of early lithification is related to depositional environment: maximum circulation of sea-water producing the most lithified hardground (Cowthick). This is directly analogous to the formation of Recent hardgrounds.

Biochemical and genetical approaches to the mechanism of action of penicillin.

Abstract: Since the discovery in 1965 that penicillin inhibits the transpeptidation reaction in peptidoglycan synthesis, a considerable effort has been put into the purification of enzymes that catalyse this reaction. This has resulted in the recognition that bacteria possess multiple forms of these penicillin-sensitive enzymes and has made it difficult to identify the precise target that penicillin inactivates to kill the organism. Recently penicillin-sensitive enzymes have been detected and studied as penicillin-binding proteins on sodium dodecyl sulphate polyacrylamide gels. The availability of this convenient method for identifying penicillin-sensitive enzymes has allowed biochemical and genetical approaches to be used to dissect their roles in the lethal effects of penicillin and other β-lactam antibiotics. Three penicillin-binding proteins (1B, 2 and 3) have been identified as killing targets for penicillin in Escherichia coli , whereas four other binding proteins are not implicated in the mechanism of action of the antibiotic. The complex biological effects that β-lactam antibiotics produce on the growth of E. coli can be explained by their interaction with the three killing targets. Progress in the correlation of penicillin-binding proteins with penicillin-sensitive enzymes and in the development of strains of E. coli that overproduce penicillin-binding proteins is discussed.

Satellite DNA is transcribed on lampbrush chromosomes

Abstract: During the lampbrush stage of oogenesis there is widespread transcription, and it has been estimated that the total amount of DNA transcribed may be an order of magnitude greater than that required to produce the necessary functional RNA for the oocyte1. We therefore considered it likely that some of the transcribed sequences have little, if any, translational significance, and may include both middle repetitive2 and highly repeated, or satellite, sequences. Satellite DNA is generally defined as rapidly reannealing DNA which has a short basic sequence that is repeated millions of times in the genome, usually in tandem arrays3,4. The short repeated length, coupled with the organisation of satellite sequences in high order molecular weight tandem arrays in heterochromatic regions, have been put forward as reasons for supposing that this type of DNA is not normally transcribed5. We report here that we have looked for and found evidence of transcription of satellite DNA on lampbrush loops in oocytes of the crested newt, Triturus cristatus carnifex.

Vasodepressor property of the converting enzyme inhibitor captopril (SQ 14 225): the role of factors other than renin-angiotensin blockade in the rat.

Abstract: 1. The peptide converting enzyme inhibitor captopril was given (1·25 mg/kg intravenously) to normal and nephrectomized rats and rats with renovascular and deoxycorticosterone hypertension. 2. Captopril lowered blood pressure to a small extent in normal and nephrectomized rats. Bradykinin infusion in nephrectomized animals, however, potentiated the vasodepressor action of captopril. 3. Captopril produced a major blood pressure fall in the early stages of Goldblatt two-kidney one-clip hypertension: even when hypertension had been present for more than 4 months, a substantial vasodepressor action was seen. Rats with deoxycorticosterone-induced hypertension also showed a significant blood pressure fall. 4. Captopril was given to salt-loaded and salt-depleted rats in which the renin-angiotensin system had been blocked by infusion of the competitive angiotensin II antagonist saralasin. Captopril still lowered blood pressure in the salt-depleted group. 5. Captopril lowers blood pressure in situations where the renin-angiotensin system is not responsible for blood pressure maintenance. Further, the fall in blood pressure produced in Goldblatt two-kidney one-clip hypertension is greater than would be predicted on the basis of renin-angiotensin blockade. It is likely therefore that captopril lowers blood pressure by an action additional to angiotensin blockade. Bradykinin potentiation is one possible mechanism by which this may take place.

The Learner's Prior Knowledge: a Critical Review of Techniques for Probing its Organization

Abstract: Summaries English How can a teacher quickly gain a useful insight into a pupil's present ideas? How can he discern the major connections in the learner's existing thought content? This article discusses several different approaches. It examines the theoretical assumptions underlying them and considers how easily they could be adapted in the classroom as part of a diagnostic approach to teaching. The author suggests a more explicit distinction between the publicly agreed version of a scientific concept and the multiple private versions held by individuals. Learning can then be viewed as development and change of the latter, as words (concept labels) change or extend their meanings. The teacher's role is at first that of a diagnostician who tries to describe the learner's existing private concept. Later he may see himself as provocateur of its changes and extensions. It is also argued that terms such as ‘cognitive structure’ and ‘concept map’ do not adequately represent the fluidity of thought in which the ...

Fraying of A-filaments into three subfilaments.

Abstract: Since Huxley1 established their bipolar structure, direct electron microscopy of A-filaments isolated from vertebrate skeletal muscle has yielded little further interpretable information about the mode of packing of the myosin molecules within the filament. Using A-filaments prepared from rat psoas muscle we have now found it possible to induce clear fraying of these filaments into subfilaments, by exposure of the preparation to very low ionic strength before contrasting with uranyl acetate. The number of such filaments observed is generally (and never in excess of) three. Considerations of symmetry suggest that the formation of these frayed filaments is compatible only with a ‘three-stranded’ model for the native A-filament, a finding in agreement with the balance of evidence recently published using other techniques2-5.

An archaean granulite-grade tonalite-trondhjemite-granite suite from scourie, NW Scotland: Geochemistry and origin

Abstract: The Lewisian complex of the Scourie-Badcall area is composed predominantly of banded tonalitic gneiss which intrudes layered gabbro-ultramafic complexes. Intrusive into both gabbro and tonalitic gneiss are homogeneous acid sheets which are trondhjemitic to granitic in composition. All rocks were subjected to granulite facies metamorphism.