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Showing papers by "Keele University published in 1986"


Journal ArticleDOI
TL;DR: In this paper, the local structural environments of Y/sup 3 +/ and Zr/sup 4 +/ in 18 wt% Y/sub 2/O/sub 3/-stabilized zirconia were studied using extended X-ray absorption fine structure spectroscopy over the temperature range.
Abstract: The local structural environments of Y/sup 3 +/ and Zr/sup 4 +/ in 18 wt% Y/sub 2/O/sub 3/-stabilized zirconia were studied using extended X-ray absorption fine structure spectroscopy over the temperature range - 120/sup 0/ to 770/sup 0/C. The measured cation-oxygen distances reflect those of the parent oxides, with the mean Zr-O distance 0.017 nm shorter than the mean Y-O distance. The spread in the Zr-nearest-neighbor and Zr-next-nearest-neighbor distances is considerably larger than observed for Y/sup 3 +/. This result is attributed to the anion vacancies being preferentially sited adjacent to the smaller Zr/sup 4 +/ cation which, with ensuing relaxations, permits a closer contact between Zr/sup 4 +/ and its oxygen neighbors. Thus, the structural environment of these Zr/sup 4 +/ ions resembles that of the 7-coordinated Zr/sup 4 +/ in monoclinic zirconia. Increasing the temperature of the sample results in the local structural environments of the two cations becoming more alike, suggesting that increased anionic mobility leads to an increasingly random distribution of anion vacancies.

216 citations


Journal ArticleDOI
TL;DR: It is concluded that Percoll, although particulate, is captured by pinocytosis, and the pattern of inhibition of uptake of polystyrene particles suggests that there is no radical discontinuity between pinocytic and phagocytic uptake, but that the contribution of phagocytetosis steadily increases with increasing particle diameter.

193 citations


Journal ArticleDOI
TL;DR: In this article, the usefulness of a phase model of burnout was examined using a questionnaire completed anonymously by eight hundred and twenty-eight men and women in police work using high and low divisions on the three subscales of the Maslach Burnout Inventory.
Abstract: This investigation examined the usefulness of a phase model of burnout. Eight hundred and twenty-eight men and women in police work provided data using a questionnaire completed anonymously. Eight progressive phases of burnout were created using high and low divisions on the three subscales of the Maslach Burnout Inventory. Measures of work setting, experienced stress, and emotional and physical well-being were significantly related to progressive phases of burnout. Work and personal experience grew worse as burnout progressed through more advanced phases. Comparisons with other data revealed potential occupational and organizational differences in numbers of respondents in various phases of burnout.

182 citations


Journal ArticleDOI
Marc Green1
TL;DR: The experiments described below investigated the psychophysical basis of correspondence matching, and judged the direction of motion for "Gabor functions" which varied in spatial frequency, orientation or phase.

140 citations


Journal ArticleDOI
TL;DR: In this paper, a method of computing the mean velocity of overland flow using dye tracing is proposed in which a specified cross-section is divided into zones of relatively uniform flow characteristics, termed partial sections.
Abstract: A new method of computing the mean velocity of overland flow using dye tracing is proposed in which a specified cross-section is divided into zones of relatively uniform flow characteristics, termed partial sections. The mean surface velocity for each partial section is determined by timing the passage of injected dye, and this figure is multiplied by 0.67, 0.70, or 0.80, depending on whether the flow is laminar, transitional, or turbulent, to give mean velocity. The mean velocity for the entire cross-section is calculated by multiplying the mean velocity of each partial section by its cross-sectional area, summing the products for all the partial sections, and dividing by the total area of the cross-section. A field test shows that mean velocity derived in this manner differs from mean velocity derived by the discharge method (i.e. by dividing discharge measured volumetrically by cross-sectional area) by an average of only 7.07 per cent. Thus the partial-section technique appears to provide a reliable method of estimating mean velocity of overland flow.

139 citations


Journal ArticleDOI
TL;DR: In this article, the relation between the Darcy-Weisbach friction factor, f, and the Reynolds number, Re, was examined for overland flow on six runoff plots in semiarid southern Arizona.

132 citations


Journal ArticleDOI
TL;DR: Experiments using isolated rat hepatocytes indicated that HPMA copolymers with high galactosamine content have higher affinity for the hepatocyte plasma membrane, which indicates intralysosomal hydrolysis of the copolymer side-chain with subsequent passage of low molecular weight degradation product across the lysosome membrane.

130 citations


Journal ArticleDOI
John Law1
TL;DR: The relevance of the sociology of science for the study of power is discussed in this article, where the authors consider the way in which a set of pharmacological experiments was undertaken in order to generate results and control aspects of the scientific and social environment.
Abstract: This paper considers the relevance of the sociology of science for the study of power. Though there is by no means complete agreement between sociologists of science, recent work in this area has suggested that (a) scientists negotiate not only about scientific but also social reality, and (b) the distinction between macro- and micro-sociology is an impediment rather than an aid to analysis. Thus, though there are indeed differences in scale, il is argued that these should be seen as the outcome of differentially effective attempts by scientists to impose versions of scientific and social reality.The present paper extends this argument by considering the way in which a set of pharmacological experiments was undertaken in order to generate results and control aspects of the scientific and social environment. It is suggested that the experimentalist acted like an entrepreneur, combining a variety of potentially unruly resources with the aim of simplifying these and reducing them to docile figures on a sheet...

126 citations


Journal ArticleDOI
TL;DR: Comparison of the amino acid sequence of the Tetrahymena actin with that of actins from other organisms suggests that TAG may code for glutamic acid, which is one of the most divergent actins sequenced to date.
Abstract: The macronucleus of Tetrahymena thermophila contains a single actin gene. We have isolated this gene from a partial plasmid library by using the yeast actin gene as a probe. The nucleotide sequence of the gene has been determined and the amino acid sequence of the potential protein deduced. The encoded protein is 375 amino acids long, one amino acid longer than the yeast actin. It is one of the most divergent actins sequenced to date, being only 75% homologous to yeast actin. Unlike the actin genes from most other organisms, it does not contain introns. The coding region contains TAA and TAG codons; the translation termination codon is TGA. Comparison of the amino acid sequence of the Tetrahymena actin with that of actins from other organisms suggests that TAG may code for glutamic acid. The gene is transcribed from multiple initiation sites between 57 and 98 nucleotides upstream of the translation start codon. The 5′ flanking region is very A+T-rich and contains numerous “TATA-like” sequences upstream of the transcription start sites.

114 citations


Journal ArticleDOI
Geoffrey Hunter1
TL;DR: In this article, the Schrodinger equation satisfied by the electron density is derived without approximation from the theory of marginal and conditional amplitudes, which arises from a factorization of the total N-electron wavefunction defined by the normalization appropriate to a conditional amplitude.
Abstract: The Schrodinger equation satisfied by the electron density is derived without approximation from the theory of marginal and conditional amplitudes. The equation arises from a factorization of the total N-electron wavefunction defined by the normalization appropriate to a conditional amplitude. This Schrodinger equation is an exact dynamical model for computing effective one-electron potentials from known N-electron wavefunctions. Results are presented for several small molecules. They display the shell structure of atoms, and the valence structure of both ionic and covalent molecules.

110 citations


Journal ArticleDOI
TL;DR: expression of the acidic glutathione S-transferase isoenzyme decreased markedly after 15 weeks of gestation so that at birth the level of activity of this isoen enzyme was only about 20% of that in samples obtained during the first trimester.

Journal ArticleDOI
TL;DR: The data provide substantive evidence that HCO3 is taken up by these marine macrophytes as a source of substrate for photosynthesis, and cannot support the observed rates of photosynthesis in these algae.
Abstract: Cook, C. M., Lanaras, T. and Colman, B. 1986. Evidence for bicarbonate transport in species of red and brown macrophytic marine algae.—J. exp. Bot. 37: 977-984. The capacity of 17 species of marine macrophytes to take up HCOJ has been examined by comparing the rate of photosynthetic 02-evolution with the photosynthetic rate which could be supported solely by C02 arising from the uncatalysed dehydration of HCOJ. No external carbonic anhydrase was detected by potentiometric assay in any of the species used. At pH 8 0, the rates of photosynthetic 02-evolution exceeded the C02 supply rate 6 to 24-fold in 15 species of red algae, and 7 to 11-fold in 2 species of brown algae. The ratio of photosynthetic 02-evolution to the C02 supply rate was even higher (19 to 101:1) at pH 9 0. It is evident from this data that the rate of C02 supply from the spontaneous breakdown of HCOJ cannot support the observed rates of photosynthesis in these algae. Thus, the data provide substantive evidence that HCO3 is taken up by these marine macrophytes as a source of substrate for photosynthesis.

Journal ArticleDOI
TL;DR: In this article, a simple rainfall simulator is described which consists of stand-alone sprinkling units with cone jet nozzles that spray downward, and perforated trickle pipes are designed that permit overland flow rates to be readily adjusted and closely controlled by simply varying the input water pressure.
Abstract: A simple rainfall simulator is described which consists of stand-alone sprinkling units with cone jet nozzles that spray downward. With a fall height of 4.57 m and water pressure of 67 kPa, the median drop size of the simulated rainfall is 2.40 mm. Rainfall from two units irrigating a 2 by 2.5 m plot has a total kinetic energy of 0.57 J/m2/s which is approximately 90% of the equivalent energy of natural rainfall at the simulation intensity of 72.4 mm/h. To simulate overland flow, perforated trickle pipes were designed that permit overland flow rates to be readily adjusted and closely controlled by simply varying the input water pressure. In field experiments in southern Arizona, rates between 572 to 1400 cm3/s were generated from a 19-mm pipe. Given their low cost, simplicity, and portability, the rainfall simulator and trickle system should be attractive to researchers working in a wide variety of geomorphic environments.

Journal ArticleDOI
01 Aug 1986-Genetics
TL;DR: An analysis of mutation frequencies with respect to neighboring base sequence, in the two strains, shows that O6-ethylguanine lesions adjacent to A:T base pairs present better targets for the excision repair machinery than those not adjacent to a:Tbase pairs.
Abstract: EMS-induced mutations within a 180 base pair region of the lacI gene of E. coli were cloned and sequenced. In total, 105 and 79 EMS-induced mutations from a Uvr+ and a UvrB- strain, respectively, were sequenced. The specificity of EMS-induced mutagenesis was very similar in the two strains; G:C----A:T transitions accounted for all but three of the mutants. The overall frequency of induced mutation was fivefold higher in the UvrB- strain compared to the Uvr+ strain. This demonstrates, at the DNA sequence level, that the presumed premutagenic lesion, O6-ethylguanine, is subject to repair by the uvrABC excision repair system of E. coli. An analysis of mutation frequencies with respect to neighboring base sequence, in the two strains, shows that O6-ethylguanine lesions adjacent to A:T base pairs present better targets for the excision repair machinery than those not adjacent to A:T base pairs.

Journal ArticleDOI
TL;DR: It is argued that this widely demonstrated failure on the part of conventional statistical methods to differentiate between competing models has a useful role to play in the development of accessible and economical applied systems, since it allows a low cost choice between systems which vary in their cognitive demands on the user and in their ease of development and implementation.
Abstract: Our paper challenges the conventional wisdom that the flat maximum inflicts the ‘curse of insensitivity’ on the modelling of judgement and decision processes. In particular, we argue that this widely demonstrated failure on the part of conventional statistical methods to differentiate between competing models has a useful role to play in the development of accessible and economical applied systems, since it allows a low cost choice between systems which vary in their cognitive demands on the user and in their ease of development and implementation. To illustrate our thesis, we take two recent applications of linear scoring models used for credit scoring and for the prediction of sudden infant death. The paper discusses the nature and determinants of the flat maximum as well as its role in applied cognition. Other sections mention certain unanswered questions about the development of linear scoring models and briefly describe competing formulations for prediction.


Journal ArticleDOI
TL;DR: The membrane around the lysosome is more than a cordon sanitaire, protecting the cytoplasm from the dangerous brew of hydrolytic enzymes in these organelles.

Journal ArticleDOI
TL;DR: In this paper, it was shown that the conditionality principle (C) and the sufficiency principle (S) alone imply the likelihood principle (L), and that S and C can each be used operationally to suppress information otherwise deemed relevant.
Abstract: Birnbaum (1962a) argued that the conditionality principle (C) and the sufficiency principle (S) implied the likelihood principle (L); he then argued (Birnbaum 1972) that C and a mathematical equivalence principle M implied L. Evans, Fraser, and Monette (1985a) gave reference details, and this paper gives proof that C alone implies L. The level of support by the profession for L is sharply less than that for S or even for C; thus the paradoxical nature of these results. In this regard, we elaborate on the Monette example (Fraser, Monette, and Ng 1984), which provides a strong case against L. We also examine closely the various proofs linking the principles and find that S and C can each be used operationally to suppress information otherwise deemed relevant. From another viewpoint this says that S and C can each be used in contexts that directly conflict with the original examples and motivations supporting them; the principles can thus be viewed as inappropriately used, or more strongly, as invalid. In either case, the result that C and S imply L or that C implies L can be regarded as noneffective in the context of discriminating applications. A resolution of the apparent anomalies can be obtained by allowing the statistical model to include ingredients additional to those usually present (particularly for subsequent use with conditionality), or alternatively by restricting the application of the principles to contexts where the conflicts would seem not to arise. Birnbaum (1962a) a montre que le principe de vraisemblance (L) decoule du principe de conditionnement (C) et du principe exhaustivite (S). Plus recemment, Birnbaum (1972) a demontre que L decoule de C et d'un certain principe d'equivalence mathematique (M). On peut trouver un expose de ces resultats dans l'article de Evans, Fraser et Monette (1985a). Dans le present travail, on demontre que L est une consequence de C seulement. Tous ces resultats sont paradoxaux a cause du peu de faveur dont jouit L dans la profession, a comparer a S ou měme a C. A ce propos, nous reprenons un exemple de Monette (Fraser, Monette et Ng 1984) qui plaide en defaveur de L. Un examen attentif des demonstrations qui unissent ces differents principes nous amene a conclure que S et C peuvent tous deux ětre utilises en pratique pour supprimer de l'information precieuse. Vu d'un autre angle, ceci revient a dire que ces deux principes peuvent ětre invoques dans des contextes qui entrent en conflit direct avec les exemples originaux et leur motivation. On peut done en venir a rejeter S et C, ou tout au moins a juger qu'ils sont employes a mauvais escient. Dans les deux cas, dire que S et C entraǐnent L ou que C entraine L peut ětre considere comme non avenu dans le cadre d'applications choisies. On peut reconcilier ces anomalies apparentes en incluant certains ingredients nouveaux dans le modele statistique usuel, surtout si on veut faire intervenir le principe de conditionnement. Une autre possibilite consiste a restreindre l'application de ces principes aux contextes ou les conflits ne semblent pas surgir.

Journal ArticleDOI
TL;DR: Extensive serological testing of this product against sera from leprosy patients and control populations, and comparison with the native glycolipid and previously synthesized neoglycoproteins, have shown that it is unparalleled in terms of sensitivity and specificity, and highly suited to replace the native sugars for the serodiagnosis of worldwide lepromatousLeprosy.

Journal ArticleDOI
TL;DR: A black and white (positive) grating pattern was superimposed in exact register on its own photographic negative so that it moved fractionally to the right, grew dimmer, moved back to the left, and grew brighter again, which gave rise to reversed apparent movement (RAM).
Abstract: A black and white (positive) grating pattern was superimposed in exact register on its own photographic negative. Four operations were repetitively applied to this positive pattern so that it moved fractionally to the right, grew dimmer, moved back to the left, and grew brighter again. This sequence produced a strong illusion of continuous apparent motion to the right for as long as the cycle was repeated. The small relative motion between the two patterns generated two new illusory effects: enhanced real movement (ERM) and reversed real movement (RRM). The dimming and brightening phases gave rise to reversed apparent movement (RAM). All three effects are attributed to spatial filtering by neural mechanisms, which shifts the effective position of the positive-negative contours.

Journal ArticleDOI
TL;DR: It is suggested that osmium sensitivity may be altered by the buffering conditions used during preparation, since gold-coating artefacts are absent and the degree of specimen collapse is less than those made using transmission-electron microscopy.

Journal ArticleDOI
TL;DR: It is suggested that the depolymerization of microtubules affects nuclear movement by altering the tensile strength of the cytoplasm, and that cytoskeletal tension mediate nuclear positioning.
Abstract: During hyphal tip growth in the fungus Basidiobolus magnus, nuclei normally maintain a constant distance from the advancing cell apex by continuously migrating forward. It is not known whether the mechanism that produces nuclear movement also mediates nuclear positioning, or whether these two processes are under separate control. By irradiating small cytoplasmic regions with an ultraviolet microbeam, the coordination between movement and positioning could be disrupted. Regardless of the distance of the target from the nucleus, anterior irradiations (those ahead of the nucleus) caused the nucleus to stop or move backwards, whereas posterior (behind the nucleus) irradiations caused an acceleration in the nuclear velocity. The nucleus retained its ability to move following irradiation, so there was only loss of control over normal positioning. These results suggest that movement and positioning are mediated by different mechanisms. Quantitative microtubule analysis demonstrated that microtubules in the target region had been depolymerized, but in other regions of the cell they were apparently normal. We suggest that the depolymerization of microtubules affects nuclear movement by altering the tensile strength of the cytoplasm, and that cytoskeletal tension mediate nuclear positioning. We also found that accelerated nuclear movement could occur when most of the microtubules surrounding the nucleus were depolymerized. A comparison of the microtubule population surrounding the nucleus in unirradiated versus irradiated cells suggested that microtubules move with nuclei. Therefore, the nucleus does not appear to move via a direct interaction with microtubules.

Journal ArticleDOI
TL;DR: Measurements of the perceived velocity of a drifting grating were obtained as a function of the position of the grating in the visual field and there were no hemifield differences in susceptibility to adaptation to moving gratings.
Abstract: Measurements of the perceived velocity of a drifting grating were obtained as a function of the position of the grating in the visual field. Identical drifting gratings were presented at the same eccentricity in the left, right, upper, and lower hemifields, and the perceived velocities were compared. A group of ten subjects considered together showed no significant hemifield differences in perceived velocity. However, some individual subjects showed marked and systematic hemifield differences, the directions of which varied among the subjects. There were no hemifield differences in susceptibility to adaptation to moving gratings.


Journal ArticleDOI
John Bale1
TL;DR: In this paper, sport and national identity: a geographical view is discussed. But the authors focus on the sport and not the national identity of the sport. The International Journal of the History of sport: Vol. 3, No. 1, pp. 18-41.
Abstract: (1986). Sport and national identity: a geographical view. The International Journal of the History of Sport: Vol. 3, No. 1, pp. 18-41.

Journal ArticleDOI
TL;DR: Concern is voiced about the danger of falling into cultural relativism when questions about the methods of financing medical services are the subject of an ethical declaration which is arrived at by consensus in the W.M.A.


Journal ArticleDOI
TL;DR: It is concluded that, as a group, cortical cells strongly sensitive to texture motion are relatively unsusceptible to adaptation.

Journal ArticleDOI
TL;DR: In this article, a study was carried out to investigate Gotlib's claim that the Beck Depression Inventory (BDI) is more a measure of general psychopathology than a specific measure of depression when applied to psychiatrically normal students.

Journal ArticleDOI
TL;DR: It is concluded that two separate cytoskeletal networks exist in fungal cells, and that an actin-containing network generates bulk cytoplasmic movement.
Abstract: We have investigated the mechanisms that hyphae of the fungus Basidiobolus magnus use to accomplish bulk movement of their cytoplasm and saltatory organelle movements. When cells were irradiated with an ultraviolet microbeam, cytoplasmic contraction occurred. The posterior cytoplasm (toward the septum) always moved forward toward the irradiated area, whereas anterior cytoplasm (between the cell tip and target) never contracted back toward the site of irradiation. Thus, there is an intrinsic polarity in the cytoplasm. Irradiations also arrested saltatory movements. The effects of irradiation on both saltations and cytoplasmic movement appear to be mediated by Ca++. Chelating exogenous Ca++ before irradiation eliminated contractions and prevented the inhibition of saltations. Furthermore, the effects of irradiation could be duplicated by using the Ca++ ionophore A23187. We relate the present results to our previous report on the effects of irradiation on the cytoskeleton [McKerracher and Heath, 1986]. We conclude that two separate cytoskeletal networks exist in fungal cells, and that an actin-containing network generates bulk cytoplasmic movement.