Showing papers by "Newcastle University published in 1985"
TL;DR: In this paper, the social mechanisms of linguistic change are discussed, and the distinction drawn by Bynon (1977) between two quite different approaches to linguistic change is made, and more recently the specification of 'possible' and 'impossible' processes of change has been seen as an important theoretical goal.
Abstract: This paper is concerned with the social mechanisms of linguistic change, and we begin by noting the distinction drawn by Bynon (1977) between two quite different approaches to the study of linguistic change. The first and more idealized, associated initially with traditional nineteenth century historical linguistics, involves the study of successive ‘states of the language’, states reconstructed by the application of comparative techniques to necessarily partial historical records. Generalizations (in the form of laws) about the relationships between these states may then be made, and more recently the specification of ‘possible’ and ‘impossible’ processes of change has been seen as an important theoretical goal.
737 citations
TL;DR: It is suggested that the presence of a high intensity of staining for the EGF receptor in human bladder tumours is associated with poor differentiation and with invasion.
592 citations
TL;DR: The results suggest that the presence of EGF receptors is associated with metastatic potential and that the growth of a proportion of poor-prognosis oestrogen-receptor-negative tumours may be regulated by peptide growth factors interacting with the EGF receptor.
493 citations
TL;DR: In this paper, the authors propose a method of associating explicit values with anticipated improvements in safety and costs with deteriorations in order that these effects can be weighed in relation to the other desirable and undesirable effects.
Abstract: MISHAN (1971) Public sector allocative and legislative decisions typically involve the assessment of a variety of prospective consequences. In some cases, notably in transport, energy and medical care, these consequences may include significant beneficial or harmful effects on individual safety. If such decisions are to be taken in a systematic and consistent manner and if, in particular, scarce resources are to be allocated efficiently and to greatest advantage, then it would seem to be necessary to have a method of associating explicit values with anticipated improvements in safety - and costs with deteriorations - in order that these effects can be weighed in relation to the other desirable and undesirable
472 citations
TL;DR: A brief description of nitrogen catabolite repression in Saccharomyces cerevisiae is provided and a mechanism, nitrogen metabolite repression of the syntheses of many enzymes and permeases involved in nitrogen nutrition, has been extensively studied in two filamentous fungi.
Abstract: Publisher Summary This chapter provides a brief description of nitrogen catabolite repression in Saccharomyces cerevisiae. The ancestral use of yeasts in industry has led to the selection of many wild-type strains of Saccharomyces cerevisiae. Saccharomyces spp. are very different from bacteria, although in vegetative growth they can be handled in a similar way. This is probably the origin of the choice of these organisms when prokaryotic cellular physiologists became interested in eukaryotic organisms. Anabolism, catabolism, and regulation of arginine metabolism have also been studied in parallel in Saccharomyces cerevisiae. The chapter also discusses the nitrogen metabolite repression in filamentous fungi. A number of filamentous fungi are able to utilize a wide range of nitrogen sources. This metabolic versatility implies a strong selective pressure for a mechanism to ensure preferential utilization of the favorable nitrogen sources. This mechanism, nitrogen metabolite repression of the syntheses of many enzymes and permeases involved in nitrogen nutrition, has been extensively studied in two filamentous fungi, the ascomycetes Aspergillus nidulans and Neurospora crassa.
308 citations
TL;DR: This chapter deals with dealing with observations in the field, the laboratory assessment of pollutant effects, and incorporating a general discussion of the validity of generalizations made to date on the overall vulnerability of coral reefs to man-made disturbance.
Abstract: Publisher Summary The aim of this chapter is to consider long-term ecological studies in the light of known effects of disturbances on coral reefs and to ask whether the effects of disturbances can be distinguished from long-term fluctuations on the reef, and also where other difficulties lie in assessment of pollution in the field. In addition, in an attempt to improve the understanding of the overall susceptibility of reef corals to marine pollution, an assessment is made of the responses of corals to stress and methods by which these responses have been monitored to date. The chapter deals with dealing with observations in the field, the laboratory assessment of pollutant effects, and incorporating a general discussion of the validity of generalizations made to date on the overall vulnerability of coral reefs to man-made disturbance. Although it is possible that any meaningful laboratory measurement of effects of stress in reef corals will involve a much more subtle approach than has been applied to date, the value of critical methods of evaluation of pollution in the field, such as those described here, should not be underestimated.
252 citations
TL;DR: In this paper, the regret theory of choice under uncertainty is introduced. But it is not a theory of regret, but of regret under uncertainty, and it is based on the assumption that the individual can foresee the various experiences of regret and rejoicing to which each action might lead.
Abstract: In a number of recent papers Graham Loomes and I have presented a theory of choice under uncertainty which can explain some frequently observed violations of expected utility theory (Loomes and Sugden, 1982, 1983a and 1983b; see also Bell, 1982). Our regret theory starts from the following idea. Suppose someone has to choose between two actions, A. and A , in conditions of uncertainty. He or she does not know which of a number of states of the world will occur. In some states of the world A1 will lead to a better consequence than A2, while in others the converse is true. Suppose the individual chooses A1 and then, when the uncertainty is resolved, it turns out that the consequence that actually occurs is worse than the one that would have occurred, had he or she chosen A2. In this event, we suggest, the individual will experience regret — the painful sensation of recognising that ‘what is’ compares unfavourably with ‘what might have been’. Conversely, if ‘what is’ compares favourably with ‘what might have been’, the individual will experience a pleasurable sensation, which we have called rejoicing. We assume that when making a choice between two actions, the individual can foresee the various experiences of regret and rejoicing to which each action might lead, and that this foresight can influence the choice that the individual makes.
242 citations
TL;DR: The use of 10 cm visual analogue scales with the end‐phrase ‘worst pain imaginable’ as being the most suitable for measuring dental pain is suggested.
Abstract: Visual analogue scales (VAS) of different lengths (5, 10, 15 and 20 cm) and with different end-phrases (troublesome, miserable, intense, unbearable and worst pain imaginable) were used to record pain in 50 male and 50 female patients with pulpitis or pericoronitis. All 100 patients successfully completed the questionnaire. High correlation was found between the scores on all the scales. Scales of length 10 or 15 cm had the smallest measurement error. The scale with the end-phrase 'worst pain imaginable' was found to be the best choice for comparing present pain or worst pain between different groups. Using this scale no significant difference was found between the scores of males and females or between those of patients with pulpitis and pericoronitis. This study suggests the use of 10 cm visual analogue scales with the end-phrase 'worst pain imaginable' as being the most suitable for measuring dental pain.
233 citations
TL;DR: The concentration of aspirin relative to salicylate in the circulation may be affected by individual variation in esterase levels and the relative roles of the different esterases, and this may influence the overall pharmacological effect.
Abstract: Esterases, hydrolases which split ester bonds, hydrolyse a number of compounds used as drugs in humans. The enzymes involved are classified broadly as cholinesterases (including acetylcholinesterase), carboxylesterases, and arylesterases, but apart from acetylcholinesterase, their biological function is unknown. The acetylcholinesterase present in nerve endings involved in neurotransmission is inhibited by anticholinesterase drugs, e.g. neostigmine, and by organophosphorous compounds (mainly insecticides). Cholinesterases are primarily involved in drug hydrolysis in the plasma, arylesterases in the plasma and red blood cells, and carboxylesterases in the liver, gut and other tissues. The esterases exhibit specificities for certain substrates and inhibitors but a drug is often hydrolysed by more than one esterase at different sites. Aspirin (acetylsalicylic acid), for example, is hydrolysed to salicylate by carboxylesterases in the liver during the first-pass. Only 60% of an oral dose reaches the systemic circulation where it is hydrolysed by plasma cholinesterases and albumin and red blood cell arylesterases. Thus, the concentration of aspirin relative to salicylate in the circulation may be affected by individual variation in esterase levels and the relative roles of the different esterases, and this may influence the overall pharmacological effect. Other drugs have been less extensively investigated than aspirin and these include heroin (diacetylmorphine), suxamethonium (succinylcholine), clofibrate, carbimazole, procaine and other local anaesthetics. Ester prodrugs are widely used to improve absorption of drugs and in depot preparations. The active drug is released by hydrolysis by tissue carboxylesterases. Individual differences in esterase activity may be genetically determined, as is the case with atypical cholinesterases and the polymorphic distribution of serum paraoxonase and red blood cell esterase D. Disease states may also alter esterase activity.
207 citations
TL;DR: In this article, a modified version of the stabilisation method of predicting resonance levels for the general one-channel Schrodinger equation is proposed, where an absorbing optical potential placed in the asymptotic region increases the stability of the resonance eigenvalues with respect to the basis size.
205 citations
TL;DR: The expression of immunoglobulin chains in yeast is investigated and the synthesis, processing and secretion of light and heavy chains, the glycosylation of heavy chain, the intracellular localization of these foreign proteins by immunofluorescence, and the detection of functional antibodies in cells co-expressing both chains are demonstrated.
Abstract: The yeast Saccharomyces cerevisiae can synthesize, process and secrete higher eukaryotic proteins1–5. We have investigated the expression of immunoglobulin chains in yeast and demonstrate here (1) the synthesis, processing and secretion of light and heavy chains, (2) the glycosylation of heavy chain, (3) the intracellular localization of these foreign proteins by immunofluorescence, and (4) the detection of functional antibodies in cells co-expressing both chains. This may provide the basis of a microbial fermentation process for the production of monoclonal antibodies. The co-expression of light and heavy chains in Escherichia coli has been reported but functional antibodies were not assembled in vivo6,7. Furthermore, only low-level assembly of these chains was found in vitro.
TL;DR: The pain experienced after third molar surgery was investigated over a 7 day post-operative period in 80 patients and the results suggest that post- operative pain is of short duration and reaches its maximum intensity in the early post-operatively period.
Abstract: The pain experienced after third molar surgery was investigated over a 7 day post-operative period in 80 patients. The results from the study suggest that post-operative pain is of short duration and reaches its maximum intensity in the early post-operative period. Nearly all patients required an analgesic at some time during the 7 days. The sex of the patient and whether there is a previous history of pericoronitis are important determinants of post-operative pain. However, the magnitude of post-operative pain does not appear to be dependent upon the operator or related to the extent of surgical trauma as assessed by operating time and radiographic score.
TL;DR: Sodium valproate has no unwanted effects on periodontal health and may be considered a safe alternative to phenytoin for the treatment of adult onset epilepsy, according to the results from this study.
Abstract: The periodontal health of 30 adult epileptic patients treated with either sodium valproate or phenytoin was compared with a control group (n = 15) of otherwise healthy patients. The 3 groups were matched for age and sex. Patients on phenytoin therapy showed significantly higher plaque scores (P less than 0.05), gingival index (P less than 0.05) and pocketing (P less than 0.05) than patients in the control group. The % of gingival hyperplasia was significantly higher (P less than 0.05) in the phenytoin-treated patients than those on sodium valproate or in the control group. However, patients on phenytoin therapy had significantly less bone loss than those on sodium valproate (P less than 0.05) or in the control group (P less than 0.01). No significant differences were observed between the sodium valproate group and the control group on any of the parameters assessed. The results from this study would suggest that sodium valproate has no unwanted effects on periodontal health and may be considered a safe alternative, regarding the periodontal aspects, to phenytoin for the treatment of adult onset epilepsy.
TL;DR: In this article, the critical Taylor number and frequency at the transition point are determined in the infinite-cylinder approximation for a wide range of parameters, and the results are compared with long-aspect-ratio experiments.
Abstract: The transition from steady axisymmetric Taylor vortices to time-dependent wavy vortices is examined. The critical Taylor number and frequency at the transition point are determined in the infinite-cylinder approximation for a wide range of parameters. The results are compared with long-aspect-ratio experiments. The variation with axial wavelength is examined, and is found to be important when the radius ratio η < 0.75. A new spatially subharmonic mode is found to be the most unstable mode in some parameter regimes. This mode is identified with the jet mode recently discovered experimentally by Lorenzen, Pfister & Mullin and by Cole.
TL;DR: It can be concluded that renal allografts adapt to pregnancy normally and that reduced GFR and proteinuria in the third trimester are common but usually transient.
TL;DR: In this article, a simple model is used to examine the balance of heat, water flow and temperature in a long-lived single-pass hydrothermal system heated by magmatic heat, which shows a catastrophic temperature transition at an exit water temperature of between 340 and 410°C depending on seafloor pressure.
TL;DR: In this article, the main emphasis is on direct current cyclic voltammetry, which is of particular value in identifying and characterising electrochemically coupled enzymatic reactions, and the importance of the rotating disc enzyme electrode in determining the effect of substrate mass transport on the response of an amperometric biosensor.
TL;DR: An analysis of the results shows that use of the software fault tolerance approach yielded a substantial improvement in the reliability of the command and control system.
Abstract: In order to assess the effectiveness of software fault tolerance techniques for enhancing the reliability of practical systems, a major experimental project has been conducted at the University of Newcastle upon Tyne. Techniques were developed for, and applied to, a realistic implementation of a real-time system (a naval command and control system). Reliability data were collected by operating this system in a simulated tactical environment for a variety of action scenarios. This paper provides an overview of the project and presents the results of three phases of experimentation. An analysis of these results shows that use of the software fault tolerance approach yielded a substantial improvement in the reliability of the command and control system.
TL;DR: In this paper, the motions of two particle shapes, one a prolate spheroid, the other a triaxial ellipsoid, are considered in parallel for four specified flow geometries which involve pure or simple shear and combinations of both.
TL;DR: In vivo, adherent mucus forms a thin but continuous cover of variable thickness over the gastroduodenal mucosa, which can be active up to luminal pH values of 5.5 and increases in luminal mucus can occur independently of increased gel thickness.
Abstract: Gastroduodenal mucus is present as a water insoluble gel adherent to the mucosal surface and as a viscous mobile solution in the lumen. The protective properties of the mucus against acid (with bicarbonate), pepsin (diffusion barrier) and mechanical damage depend on the quality (structure) and quantity (thickness) of the adherent mucus gel layer. Adherent mucus is a viscoelastic gel which is 95% (v/v) water. It is permeable to ions and smaller molecules (Mr c. 1000), but is impermeable to large proteins (Mr,c. 17,000) including pepsins. However, mucus is solubilized rapidly by pepsin, more slowly (>-1 h) by thiol agents, and is unchanged following exposure to bile, acid and ethanol (<40%). Glycoprotein macromolecules (Mr≥2×106) are the structural components of the mucus gel and have a polymeric, structure of glycoprotein subunits (Mrc. 5×105, for gastric mucus) joined by disulphide bridges between their protein cores. This glycoprotein polymerization, which is essential for gel formation and hence function, is the site of action of proteolytic enzymes and thiol agents. The glycoprotein polymeric structure is deficient in antral mucus from patients with peptic ulcer disease.In vivo, adherent mucus forms a thin but continuous cover of variable thickness (50–450 μm in man, about two-fold less in rat) over the gastroduodenal mucosa. Pepsin in gastric juice will rapidly dissolve this mucus cover and can be active up to luminal pH values of 5. Mucus erosion by pepsin or by abrasion must be balanced by its secretion. Prostaglandins and carbachol stimulate a rapid increase (within minutes) in mucus thickness of up to two-fold. Soluble luminal mucus can be increased by mucus secretagogues, mucosal damaging agents, or peptic degradation of adherent mucus. Increases in luminal mucus can occur independently of increased gel thickness.
TL;DR: In A.D. 131/2 the emperor Hadrian created a new organization of Greek cities, the Panhellenion, and explored, from a provincial perspective, the implications of this novel initiative by Rome in Greek affairs as discussed by the authors.
Abstract: In A.D. 131/2 the emperor Hadrian created a new organization of Greek cities, the Panhellenion. This paper is the first of two in which we explore, from a provincial perspective, the implications of this novel initiative by Rome in Greek affairs.The foundation of the Panhellenion belongs to a series of interventions by Hadrian in the Greek world, the others mostly in the form of acts of benefaction towards individual communities. Although Hadrian's reign marked a watershed in Greek relations with Rome, these relations had already evolved significantly over the previous two generations. The two most obvious developments lay in the overlapping areas of cultural and political life. Not only did educated Greeks and Romans now share an intellectual milieu, but a renaissance of Greek literary and rhetorical activity had begun under the leadership of provincials enjoying (more often than not) close ties with Rome. At the same time, a Roman career had become more available to ambitious Greeks; a marked increase in the numbers of Greek senators may be dated to the last quarter of the first century.
TL;DR: A technique which utilizes differential thermal analysis and a divided fibre optic system is a valuable aid to the study of the curing behaviour of lightactivated composites.
TL;DR: It is proved that the conjecture that the coincidence limit of the heat kernel in curved spacetime can be written in a new form in which the coefficients of the proper-time series have no terms containing the scalar curvature R is proved to third order in the proper time.
Abstract: We conjecture that the coincidence limit of the heat kernel (or the kernel of the Feynman propagator) in curved spacetime can be written in a new form in which the coefficients of the proper-time series have no terms containing the scalar curvature R. This effectively sums all terms containing R. We prove our conjecture to third order in the proper time. This permits one to obtain certain nonlocal effects in a general curved spacetime through a one-loop calculation.
TL;DR: It is concluded that both binding and postbinding defects in insulin target organ cells contribute to the marked in vivo insulin resistance of hepatic cirrhosis.
TL;DR: A drama of learning: Mantle of the expert as discussed by the authors is a classic example of the Mantle-of-the-expert approach to teaching through drama, which is also related to our work.
Abstract: (1985). A drama of learning: Mantle of the expert. Theory Into Practice: Vol. 24, Educating Through Drama, pp. 173-180.
TL;DR: Evidence that the factor structure of the Maslach Burnout Inventory scales may change when the scales are used as part of a wider range of items assessing feelings about work is reported.
Abstract: This study reports evidence that the factor structure of the Maslach Burnout Inventory scales may change when the scales are used as part of a wider range of items assessing feelings about work Results from a sample of nursing staff suggested that feelings of being ‘emotionally drained’ were distinct from feelings of ‘frustration and discouragement about work’ The extent (or lack) of personal accomplishment was confirmed as a salient factor among feelings about work Scores on the scale for this sample of nurses were comparable with those in other studies, except that depersonalization scores were lower This may reflect either lower incidence or lowered awareness
TL;DR: Actinomycetes containing meso-diaminopimelic acid, arabinose and galactose in the wall peptidoglycan but lacking mycolic acids were recovered in two groups and suggest that minimal descriptions of wall chemotype IV taxa should ideally include information on menaquinone composition.
Abstract: The menaquinones of 141 actinomycetes representing the genera Caseobacter, Mycobacterium, Nocardia, Rhodococcus and some related taxa lacking mycolic acids were examined by mass spectrometry. The mycolic acid-containing strains were assigned to four groups on the basis of the predominant isoprenologue detected: Rhodococcus coprophilus, R. equi, R. erythropolis, R. globerulus, R. rhodnii, R. rhodochrous and R. ruber contained dihydrogenated menaquinones with eight isoprene units; Nocardia asteroides, N. brasiliensis, N. carnea, N. otitidis-caviarum and N. transvalensis contained tetrahydrogenated menaquinones with eight isoprene units; Caseobacter polymorphus, R. bronchialis, R. rubropertinctus and R. terrae and representatives of twenty-one approved species of Mycobacterium contained dihydrogenated menaquinones with nine isoprene units; a single strain of 'Mycobacterium album', contained unsaturated menaquinones with nine isoprene units. Actinomycetes containing meso-diaminopimelic acid, arabinose and galactose in the wall peptidoglycan but lacking mycolic acids were recovered in two groups: tetrahydrogenated menaquinones with eight isoprene units were the main components from 'Nocardia' autotrophica and Pseudonocardia thermophila whereas Saccharopolyspora hirsuta and Pseudonocardia spp. contained tetrahydrogenated menaquinones with nine isoprene units. Promicromonospora citrea and 'skin coryneforms' with LL-diaminopimelic acid and glycine in the wall peptidoglycan also contained tetrahydrogenated menaquinones with nine isoprene units as the major isoprenologue. In contrast, representatives of the genera Kitasatoa, Microellobosporia, Streptomyces and Streptoverticillium were characterized by the presence of complex mixtures of tetra-, hexa- and octa-hydrogenated menaquinones with nine isoprene units. The menaquinone data correlate well with other developments in actinomycete systematics and confirm earlier suggestions that menaquinone analyses are of value in both the classification and identification of actinomycetes. Indeed, the data suggest that minimal descriptions of wall chemotype IV taxa should ideally include information on menaquinone composition.
TL;DR: It is suggested that, for accurate estimation of free insulin concentrations in insulin-treated diabetic patients, immediate centrifugation of blood and extraction of insulin antibodies is mandatory.
Abstract: Plasma insulin concentrations of insulin-treated diabetic patients must be measured after removal of insulin antibodies, usually by precipitation with polyethylene glycol (PEG). Details of the procedure vary between laboratories; commonly, frozen plasma is thawed and incubated at 37 °C to restore a presumed equilibrium between free and antibody bound insulin before extraction. The present study was designed to investigate methodological factors that could affect the measured free insulin concentration. In normal subjects PEG extraction of globulins did not disturb measurement of insulin concentrations, whether carried out after incubation for 2 h at 37 °C, or storage at -20 °C, in either order. Freezing or incubation of PEG extracts of plasma from insulin-treated patients also failed to disturb the measured concentrations of free insulin. When plasma from patients was incubated for 2 h after storage, a marked scatter (51–272%) of measured results occurred when compared to bedside extraction. This problem was not overcome by buffering with HEPES or storage at a lower temperature (-40 °C). Incubation at 0 °C also severely disturbed the apparent concentrations. Incubation of plasma before extraction and freezing also disturbed the measured result, a problem not corrected by maintaining near physiological pH. Total insulin concentrations measured on acid extracts were not disturbed by any of these manoeuvres. The temperature of centrifugation of blood at the time of venepuncture did not influence the result. Furthermore, when insulin concentrations were rising or falling similar percentage changes were seen over a 30-min incubation of plasma before extraction on the day of venepuncture, suggesting that equilibrium between free and bound insulin is maintained in vivo. We suggest that, for accurate estimation of free insulin concentrations in insulin-treated diabetic patients, immediate centrifugation of blood and extraction of insulin antibodies is mandatory.
TL;DR: The thermodynamics of carbothermal reduction and nitriding of silica in the temperature range 1200 to 1600°C have been evaluated and may be used to determine the conditions required to form silicon nitride, silicon oxynitride or silicon carbide.
Abstract: The thermodynamics of carbothermal reduction and nitriding of silica in the temperature range 1200 to 1600° C have been evaluated and may be used to determine the conditions required to form silicon nitride, silicon oxynitride or silicon carbide. The products of reaction are, however, frequently dictated by kinetic rather than thermodynamic considerations and the presence of impurities in the silica and carbon reactants is especially important. α-silicon nitride has been prepared from high purity silica and carbon but under identical conditions of temperature and nitrogen pressure the chemistry of the process changes markedly when a small amount of iron is added to the reactants. Below 1320° C iron has no effect and pure α-silicon nitride is formed but with increasing temperature the proportion of silicon carbide in the product increases. Above 1550° C silicon carbide is the stable solid phase in the Si-C-O-N system at 1 atm pressure. The process chemistry has been investigated by high-temperature reaction studies and X-ray diffraction and reaction mechanisms are proposed on the basis of microstructural observations of reactants and products.
TL;DR: Glomerular filtration rate showed a slow rise with gestational age, and a rapid rise with increasing postnatal age which was shown to be due to a temporary cessation of growth rather than a true acceleration in renal maturation.