Showing papers by "University of St Andrews published in 1977"
TL;DR: Within the "glimmerite" nodules occurring within kimberlite pipes, the MARID suite consisting of varying proportions of mica, amphibole, rutile, ilmenite and diopside is recognized as discussed by the authors.
290 citations
TL;DR: Electromyography has been used to study the recruitment of red, pink and white muscle fibres of the Mirror carp at different swimming speeds and it would appear that there is a relationship between the speed of contraction of the fibre types and the locomotory speed at which they are recruited.
Abstract: Electromyography has been used to study the recruitment of red, pink and white muscle fibres of the Mirror carp at different swimming speeds. Locomotion below 0.3–0.5 L/S (lengths per second) is achieved primarily by fin movements after which the red myotomal muscle becomes active. Pink muscle fibres are the next type to be recruited at speeds around 1.1–1.5 L/S. White muscle is only used for fast cruising in excess of 2–2.5 L/S and during bursts of acceleration.
288 citations
TL;DR: The characteristic features of C-NMR spectra which permit structural assignments to be made are discussed.
227 citations
TL;DR: In this paper, it was shown that the instability is closely similar to the onset of thermal convection in horizontal fluid layers, and the relationship of this mechanism to instability models of Garrett and Gammelsrod is clarified.
Abstract: Equations governing the current system in the upper layers of oceans and lakes were derived by Craik & Leibovich (1976). These incorporate the dominant effects of both wind and waves. Solutions comprising the mean wind-driven current and a system of ‘Langmuir’ cells aligned parallel to the wind were found for cases in which the wave field consisted of just a pair of plane waves. However, it was not clear that such cellular motions would persist for the more realistic case of a continuous wave spectrum.The present paper shows that, in the latter case, infinitesimal spanwise periodic perturbations will grow on account of an instability mechanism. Mathematically, the instability is closely similar to the onset of thermal convection in horizontal fluid layers. Physically, the mechanism is governed by kinematical processes involving the mean (Eulerian) wind-driven current and the (Lagrangian) Stokes drift associated with the waves. The relationship of this mechanism to instability models of Garrett and Gammelsrod is clarified.
155 citations
TL;DR: In this article, the binding modes of ionic, unidentate-covalent, and bidentate covalent metalligand binding modes are distinguished in solution by 31P n.m.r.
139 citations
TL;DR: Seeds tolerant of soaking are therefore similar to the roots of flood-tolerant plants where ethanol production is also limited during periods cf anoxia.
Abstract: SUMMARY
Seeds resistant to soaking injury and the associated condition of anoxia regulate glycolysis so that there is minimal production of ethanol. This regulation is achieved by low anaerobic respiration rates, the minimization of the Pasteur effect, and by the production of lactate as an alternative to ethanol during the early stages of anaerobiosis. Resistant seeds differ from those intolerant of soaking where anoxia causes an acceleration of glycolysis, an induction of alcohol dehydrogenase activity and the production of large quantities of ethanol as the exclusive end-product of glycolysis. Seeds tolerant of soaking are therefore similar to the roots of flood-tolerant plants where ethanol production is also limited during periods cf anoxia.
121 citations
TL;DR: In this paper, the central part of the Pan-African belt in west Africa was characterised by intense orogenic plutonism, and the peak of magmatic activity occurred 610 ± 10 m.y.
103 citations
TL;DR: The recent publications of computer models involving many thousand complexing reactions permit a more basic and comprehensive study of metal-ion equilibria in biofluids.
99 citations
TL;DR: The finite element method has been used to determine stress and strain histories in circumferentially notched bass which undergo creep due to steady loading as mentioned in this paper, and a semi-circular notched bar and a British Standard V-notched bar are studied.
91 citations
TL;DR: There is at present no justification for the common practice of calling the midgut gland of the crustacean an hepatopancreas, as no firm evidence was obtained for gluconeogenesis from lactate and for ketogenesis from fatty acids.
Abstract: 1.
1. The possibility of the midgut gland of the crustacean (Cherax destructor) functioning as a liver has been investigated.
2.
2. Seven species of crustaceans accumulate lactic acid in the haemolymph when exercised. The rate of disappearance of lactate in Homarus gammarus and in C. destructor is very slow when compared with man.
3.
3. In the midgut gland of C. destructor no firm evidence was obtained for gluconeogenesis from lactate and for ketogenesis from fatty acids.
4.
4. It is concluded that there is at present no justification for the common practice of calling the midgut gland an hepatopancreas.
88 citations
TL;DR: In this article, the Gibbs free energy of activation (JG*) was found to increase and enzyme activity decreased with increasing ionic strength within the physiological temperature range of each species.
Abstract: Summary. Studies have been carried out on the Mg2+Ca2+-myofibrillar A TPase from the muscles of fish adapted to different environmental temperatures. The thermal stability of the A TPase is strongly correlated with mean habitat temperature. Activities of Antarctic fish A TPases are significantly higher at low temperatures than those of temperate and tropical water species. The effects of ionic strength on A TPase activity have also been studied. The Gibbs free energy of activation (JG*) was found to increase and enzyme activity decrease with increasing ionic strength within the physiological temperature range of each species. Significantly lower values of JG*, of around 1 Kcal/mole, are obtained for the A TPase of cold-adapted compared to tropical fish. Enthalpic and en tropic activation energies were also reduced in the cold adapted A TPases. It is postulated that the reduction of the enthalpic activation term in the cold adapted enzyme confers the advantage of reducing the temperature sensitivity of the rate limiting step thus partly compensating for the low heat content of the ce.1lular environment. Possible molecular mechanisms of temperature compensation in fish myofihrillar A TPases are discussed.
TL;DR: Three groups of four monkeys were trained to negotiate a small hand ("stylus") maze, and to use a "pointer" to guide response in a two-choice position discrimination task, and error analysis suggests an interpretation of the frontal deficit on the pointer task in terms of perseveration on position.
TL;DR: In this paper, the form of the meniscus in Czochralski growth is described and it is argued that the most successful servo-control techniques are those which sense changes in menicalus shape rather than changes in diameter only.
TL;DR: In this article, Verbal Protocol Analysis, a technique devised to investigate formal problem-solving, is examined theoretically and adapted for analysis of this task, showing the need for a number of mental structures and their associated control processes.
TL;DR: In this paper, a finite element procedure for the solution of axi-symmetric creep deformation problems has been used to study the design of circumferentially notched bars for use in the creep-rupture testing of materials.
TL;DR: The three enzymes, Na/K‐ATPase, glyceraldehyde‐3‐phosphate dehydrogenase and NADH‐ferricyanide reductase, were found not to change with age, but significant age‐dependent decreases were observed in the cases of acetylcholinesterase, phosphoglycerate kinase, purine nucleoside phosphorylase and alkaline phosphatase.
Abstract: Summary. Human erythrocytes from healthy male donors were fractionated with respect to in vivo age by simple centrifugation in order to characterize changes in the functional integrity of the membrane during the life-span of the cell. The three enzymes, Na/K-ATPase, glyceraldehyde-3-phosphate dehydrogenase and NADH-ferricyanide reductase, were found not to change with age, but significant age-dependent decreases were observed in the cases of acetylcholinesterase, phosphoglycerate kinase, purine nucleoside phosphorylase, adenylate kinase, Mg-ATPase and alkaline phosphatase.
The possibility mat these changes were attributable to mechanisms other than age-related inactivation, such as reticulocyte contamination, differential resealing and crypticity, was investigated. Only the decrease in acetylcholinesterase could be explained wholly in terms of reticulocyte contamination. A decrease in membrane integrity on ageing was observed, which accounted for approximately half the change in alkaline phosphatase and may have contributed to the other enzyme activity changes. This membrane integrity effect masked a real decrease in the highly cryptic NADH-ferricyanide reductase, this decrease being apparent only after total disaggregation of the membrane with nonionic surfactant.
TL;DR: In this paper, the authors present a theory based on a hierarchy of multiple limiting physical and biotic factors for study of the controls governing community composition, biomass and productivity in benthic synecology.
Abstract: The state of knowledge of marine and estuarine sublittoral benthic synecology may be said to be still in a descriptive stage of study. Much of the recent literature of the subject concerns either qualitative and quantitative descriptions of communities or associations, or concepts of such associations including diversity, stability and succession. It is the purpose of this paper to present a theory, based on a hierarchy of multiple limiting physical and biotic factors, for study of the controls governing community composition, biomass and productivity. Three major biotic factors are considered as qualitative and quantitative controls: food supply, supply of colonizing larvae, and interspecies competition. They are discussed and new techniques are suggested which may help in understanding the mechanisms of control.
TL;DR: In this article, the inter-bound state excitation spectrum of the N C donor in cubic β-SiC was measured through the two-electron transition satellites observed in the luminescent recombination of excitons bound to neutral N donors.
TL;DR: It is found that the rate of predation on artificial Batesian mimics was a function of the level of distastefulness of the model, and experience with the more aversive models resulted in the rejection of mimetic pellets further away from the model on the stimulus dimension of colour.
TL;DR: In this article, it was shown that hept-cis-4-enal is not the major component responsible for the off-flavour that develops in cod during frozen storage.
Abstract: In previous reports it was shown that hept-cis-4-enal is the major component responsible for the off-flavour that develops in cod (Gadus morhua) during frozen storage. Many other volatile components are present and a number are identified in this paper. Two of these, hept-trans-2-enal and hepta-trans-2, cis-4-dienal have been shown to possess flavour notes or tones similar in character to the cold storage flavour. Recognition thresholds of these compounds have been determined in aqueous solution and from this, and the nature of their flavour it has been concluded that they are not as important in the cold storage flavour as hept-cis-4-enal. Production of these three compounds has been monitored and found to increase with time and temperature of frozen storage. Taste panel assessments of the fish show a good correlation (0.84) with the hept-cis-4-enal content. Evidence is presented which is strongly indicative that these compounds are produced by liquid oxidation.
TL;DR: There is now sufficient comparative data on male and female meiosis, in both plants and animals, to show that the extent of intra-chromosomal recombination in some organisms may be much the same on the female as on the male side, whereas other organisms show extreme sexual divergence in this regard.
Abstract: For technical reasons studies of chiasma frequency and distribution, and hence of intrachromosomal recombination, have mostly been confined to male meiosis. However, there is now sufficient comparative data on male and female meiosis, in both plants and animals, to show that the extent of intra-chromosomal recombination in some organisms may be much the same on the female as on the male side, whereas other organisms show extreme sexual divergence in this regard. The evolutionary significance of such diversity remains enigmatic.
TL;DR: Ethananol can always be detected in the trunks and roots of forest trees and in the roots of pot-grown tree-seedlings under both flooded and unflooded conditions, indicating that tree-roots and trunks exist continually in a state of total or partial anoxia.
Abstract: SUMMARY
Ethanol can always be detected in the trunks and roots of forest trees and in the roots of pot-grown tree-seedlings under both flooded and unflooded conditions. The constant presence of this anaerobic product indicates that tree-roots and trunks exist continually in a state of total or partial anoxia. In forest trees the ethanol content at the base of the tree trunk was correlated significantly with that found in the roots and fluctuated throughout the year, reaching a maximum in winter and early spring. The highest values were noted in trees exposed to the greatest amount of flooding. Pot-grown trees of Pinus contorta and Picea sitchensis showed an immediate reaction to anoxia with a simultaneous increase in root ethanol content when placed in unaerated water culture. In the flood-intolerant P. sitchensis anoxia induced a twelve-fold increase in ethanol and this attained 5 μmoles g−1 fresh weight, while over the same period the ethanol in the roots of the flood-tolerant Pinus contorta increased only three-fold to 0.7 μmoles g−1 fresh weight. These species provide another example of flooding tolerance being found in association with the ability to limit ethanol production.
TL;DR: In this article, it was shown that the singular behavior exhibited by a solution of the magnetoatmospheric wave equation for motion in the presence of a horizontal magnetic field is a special case of the "valve" type critical level discussed by Acheson (1973), with the difference that the 'valve effect' does not strictly occur; waves are captured as they approach the singular level from either side and are neither reflected or transmitted, but constrained to propagate along the field line.
Abstract: It is shown that the singular behaviour exhibited by a solution of the magnetoatmospheric wave equation for motion in the presence of a horizontal magnetic field is a special case of the ‘valve’ type critical level discussed by Acheson (1973), with the difference that the ‘valve effect’ does not strictly occur; waves are captured as they approach the singular level from either side and are neither reflected or transmitted, but constrained to propagate along the field line. This effect is also likely to occur for purely vertical fields. The possible importance of such critical levels to solar physics is discussed.
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TL;DR: The minutes of the business meetings and a summary of the scientific meetings are presented, with the abstracts of some of the papers read, in this paper, where the authors present a survey of their work.
Abstract: Commission 42 convened for two business meetings and two scientific sessions. In the following, the minutes of the business meetings and a summary of the scientific meetings are presented, with the abstracts of some of the papers read.
TL;DR: In this paper, the principle changes which have occured during the last three years in the techniques used to produce single crystals of oxide and similar single crystals from the melt are reviewed.
TL;DR: In this article, the ability of two and three year old children to comprehend in, on and under was tested in five contexts and the results suggest that the young child's comprehension of instructions involves an interaction between aspects of the instruction's lexis and syntax and the child's construal of context.
TL;DR: In this paper, the authors proposed a resonator design for eliminating coma and astigmatism in laser resonators with off-axis focusing, and demonstrated that it is only possible to compensate for both at a unique offaxis angle.
TL;DR: Values of the generalized Mahalanobis D2 and percent overlap in frequency distributions of meristic characters suggest that considerable straying of fish, especially between adjacent areas occurs during upstream spawning migration.
Abstract: Examination of more than 2,000 alewives (Alosa pseudoharengus) and blueback herring (A. aestivalis) from various areas in the Saint John River, N.B., showed differences in their morphometric and meristic characters. They differed also in length and age, compositions, spawning time, length and age at maturity, back-calculated lengths, and growth parameters. Within each species, between-area comparisons showed significant differences in some of their meristic characteristics.
TL;DR: A 12-year-old female with total agenesis of the corpus callosum has been tested on several tasks involving tactile perception and motor coordination and a deficit was found in the ability to tactually cross-identify objects, but a deficit in tactile cross-localization was evidenced.