Showing papers by "University of Aberdeen published in 1973"
TL;DR: As assessed in this situation, learning was absent in those rats with the most complete ablations of the locus coeruleus, although these rats showed normal weight gain and normal motor and exploratory activity.
Abstract: Bilateral lesions of the nucleus locus coeruleus in rats deplete the cerebral cortex of norepinephrine and significantly diminish the rate of increase of running for food reward in a simple L-shaped runway. As assessed in this situation, learning was absent in those rats with the most complete ablations of the locus coeruleus, although these rats showed normal weight gain and normal motor and exploratory activity.
250 citations
TL;DR: All patients with anorexia nervosa were extracted from three psychiatric case registers and in all three areas the number of cases reported per year was increasing, and in Camberwell, but not in Monroe County or North-East Scotland, there was a significant excess of patients from middle-class backgrounds.
Abstract: All patients with anorexia nervosa were extracted from three psychiatric case registers— North-East Scotland, Camberwell, and Monroe County. The average incidence varied from 0·37 per 100,000 population per year in Monroe County to 1·6 per 100,000 in North-East Scotland, in all three areas the number of cases reported per year was increasing, and in Camberwell, but not in Monroe County or North-East Scotland, there was a significant excess of patients from middle-class backgrounds.
235 citations
TL;DR: There was a significant relationship between plasma volume at 38 weeks' gestation and the birthweight of the baby.
225 citations
TL;DR: In this article, carbon-13 frequency shifts for C 2 H 4, C 2 D 4, and as -C 2 H 2 D 2 have been measured in isotopic solid solutions in crystalline films at 60 K.
218 citations
TL;DR: A theory is proposed which relates the learning theory concepts of reinforcement and incentive motivation to visceral afferent pathways in the central nervous System and is used to explain recent evidence that there is a relationship between catecholamine-containing neurones and electrical self-stimulation behaviour.
Abstract: A theory is proposed which relates the learning theory concepts of reinforcement and incentive motivation to visceral afferent pathways in the central nervous System. Herrick's hypothesis of the functional significance of the difference between olfactory and gustatory connexions is used to demonstrate a parallel between olfactory and ‘drive inducing’ stimuli in their role in energizing and directing behaviour; and a somewhat similar parallel between the roles of gustatory and ‘reinforcing’ stimuli. This theory is used to explain recent evidence that there is a relationship between catecholamine-containing neurones and electrical self-stimulation behaviour. It is proposed that self-stimulation can be understood as resulting in most instances from activation of one or both of two ascending Systems: (1) a ‘reinforcement System’ (which may be phylogenetically related to gustation), arising from cell-bodies in the locus coeruleus and releasing noradrenaline as a neurohumour from terminals distributed to the neocortex; and (2) an ‘incentive motivational’ System (which may be a phylogenetic derivative of olfactory pathways), arising from cell bodies in the ventral mesencephalon and releasing dopamine from terminals distributed to the corpus striatum and related nuclei. Some implications of this theory for the action of certain psychotropic drugs and the ‘catecholamine hypothesis’ of affective disorders are discussed.
215 citations
TL;DR: Most women in Western society seem to reach the menopause in their early fifties; the median age in this Aberdeen series being 50.1 years as discussed by the authors, and only the vasomotor disorders, flushing and night sweats, were correlated with the menopausal onset.
Abstract: Most women in Western society seem to reach the menopause in their early fifties; the median age in this Aberdeen series being 50.1 years. As far as symptoms were concerned, only the vasomotor disorders, flushing and night sweats, were definitely correlated with the menopause.
194 citations
TL;DR: Two main theories of the relationship between exploratory behaviour and anxiety or fearfulness are: (a) ‘Two-factor theory’, according to which novel stimuli evoke both curiosity and fear/anxiety, and (b) the ‘Halliday-Lester theory, where the fear aroused by novelty results in either approach (low fear) or avoidance (high fear).
Abstract: Two main theories of the relationship between exploratory behaviour and anxiety or fearfulness are: (a) ‘Two-factor theory’, according to which novel stimuli evoke both curiosity and fear/anxiety, with exploration as the outcome of competing tendencies to approach and avoid, and (b) the ‘Halliday-Lester theory’, where the fear aroused by novelty results in either approach (low fear) or avoidance (high fear). Relevant evidence comes from animal studies varying fear by manipulating either environmental or intrinsic factors. This evidence is largely compatible with the two-factor theory and some results which have been presented as critical support for the Halliday-Lester theory are actually equivocal.
162 citations
162 citations
TL;DR: In this paper, a general account of both the electrical and the mechanical aspects of the design of capacitative transducers and their associated electronic circuitry suitable for observing displacements of the order 10-2 to 10-11 mm.
Abstract: A general account is given of both the electrical and the mechanical aspects of the design of capacitative transducers and their associated electronic circuitry suitable for observing displacements of the order 10-2 to 10-11 mm. The lower figure is the order of magnitude of noise and drift averaged over a second, the drift over a day of the order 10-8 to 10-9 mm. Their application is illustrated by descriptions of an apparatus to explore the limits of performance, a moderately sensitive micrometer, and two geophysical instruments, a tiltmeter and a gravimeter. Full details of a general purpose electronic system are given.
160 citations
TL;DR: In this paper, the relationship between CH bond stretching frequencies, bond lengths and dissociation energies, previously studied by Bernstein, is reexamined with fresh data of all kinds.
147 citations
TL;DR: Increasing the daily dose of aerosol beclomethasone dipropionate from 400 μg to 1600 μg.
TL;DR: Intracellular recordings from neurones of the myenteric plexus of the guinea-pig ileum suggest that an inward Ca(++) current during the action potential is essential for the slow after-hyperpolarization.
Abstract: Intracellular recordings were made from neurones of the myenteric plexus of the guinea-pig ileum. The slow after-hyperpolarization which followed an action potential in some neurones was abolished by Mn++, La+++ and by solutions which contained no Ca++. In these neurones, the action potential and the slow after-hyperpolarization persisted in Na+-free solutions or in the presence of tetrodotoxin (2 μM). The findings suggest that an inward Ca++ current during the action potential is essential for the slow after-hyperpolarization.
TL;DR: The use of recently available frequency, 13C frequency shift, Coriolis coupling, and centrifugal distortion data enables the GHFF of formaldehyde to be determined with some degree of precision as discussed by the authors.
TL;DR: The results show that human glomerular basement membrane has a natural history essentially similar to rat glomerULAR basement membrane, and a model of the functional morphology of glomerul basement membrane is proposed.
Abstract: A comprehensive account of the natural history of normal glomerular basement membrane is prerequisite to elucidating the pathogenesis of numerous renal diseases. The experimental argyric technique was investigated, adapted and applied in a long term sequential, electron microscopic study of normal glomerular basement membrane in the rat. The results demonstrate that a major component of glomerular basement membrane is secreted by the visceral epithelial cells. This component is laid down on the epithelial side and slowly moves towards the endothelial side of the basement membrane as new basement membrane material continues to be secreted. The old basement membrane material is removed from the endothelial aspect of the membrane and passes by way of the lamina rara interna to the mesangial matrix for subsequent ingestion by the mesangial cells. This process is continuous and slow; the time for complete renewal of the glomerular basement membrane in the rat is of the order of twelve months. Secretion of this component, by the epithelial dells, is effected by a vascular-coated pit mechanism and removal, by the mesangial cells, is effected by a phagocytic mechanism. The results further indicate the presence of a second component in glomerular basement membrane. This second component is probably of endothelial origin and has a much faster turnover rate than the main, or epithelial derived, component. Study was also made of glomeruli from two cases of human argyria and though the observations perforce are limited, the results show that human glomerular basement membrane has a natural history essentially similar to rat glomerular basement membrane. On the basis of these experimental observations, correlated with the results of previous investigations, a model of the functional morphology of glomerular basement membrane is proposed. The potential applications of this model are briefly indicated.
TL;DR: In this article, the conductivities of Li4SiO4 solid solutions are compared with those of other known Li-conducting solids, and the best all-round, polycrystalline Li-electrolytes yet found for temperatures above c. 200°C.
Abstract: Lithium orthosilicate, Li4SiO4, and its solid solutions are a new group of solids of high ionic conductivity. Either Li or Si may be at least partially replaced by several other di-, tri- or tetra-valent cations. Highest conductivities were found for solid solutions with Si partially replaced by Ti; typical values were 10−3 to 10−4 Ω−1 cm−1 at 300°C rising toc. l Ω−1 cm−1 by 700°C. The solid solutions are easy to prepare and are stable in air. Conductivities were measured on pressed cubes of powdered material using variable frequency a.c. methods. The conductivities of these Li4SiO4 solid solutions are compared with those of other known Li-conducting solids; Li4SiO4 solid solutions are probably the best all-round, polycrystalline Li-electrolytes yet found for temperatures abovec. 200°C.
TL;DR: Analysis of chiasma frequency and position leads to a model for the mechanism controlling distribution which has three main components: bivalents vary in length between cells due to unknown factors and increase in bivalent length leads to an increase in chiasm frequency.
Abstract: Chiasma distribution at diplotene in Schistocerca gregaria males can be taken to indicate the positions at which crossing over occurred prior to diplotene since chiasma terminalisation is entirely absent. Analysis of chiasma frequency and position leads to a model for the mechanism controlling distribution which has three main components. — i) The bivalents vary in length between cells due to unknown factors and increase in bivalent length leads to an increase in chiasma frequency. — ii) Within bivalents chiasma initiation is sequential from telomere to centromere with the first chiasma usually forming close to the telomere. — iii) Interference operates with the same polarity and determines a distance within which crossing over is precluded.
TL;DR: The polypeptide bacitracin has been found to meet the requirements of an ideal wetting agent for use in this situation, and it is superior to the commonly‐used bovine serum albumin (BSA) in several respects.
Abstract: SUMMARY
The most frequently used method of enabling aqueous suspensions of small, particulate, biological specimens to spread on the hydrophobic support films required for electron microscopy, is to add a surface-active compound to the suspensions. The requirements of an ideal wetting agent for use in this situation are outlined. The polypeptide bacitracin has been found to meet all these requirements, and it is superior to the commonly-used bovine serum albumin (BSA) in several respects. Bacitracin molecules are much smaller than those of BSA, and unlike BSA molecules they are not visualized by negative staining. Thus bacitracin produces a very even background against which the fine details of a specimen can be more easily interpreted. It facilitates the penetration of negative stain into small crevices and it produces a smaller halo of negative stain around specimen particles. Its use for spreading electron dense specimens is also demonstrated. Bacitracin is compatible with at least five commonly-used negative stains, namely ammonium molybdate, potassium phosphotungstate (KPT), potassium silicotungstate, sodium tungstate and uranyl acetate. It is also biologically acceptable for use with a wide range of specimens. There is no evidence of bacitracin causing damage to specimens examined representing macromolecules, animal, plant and bacterial viruses, bacteria and subcellular organelles.
TL;DR: In this article, the use of CH stretching frequencies in CHD2-substituted methyl compounds is proposed as an approximate method for estimating the unperturbed positions of CH3 stretching bands affected by Fermi resonances involving CH3 deformation overtones and combinations.
TL;DR: The authors showed that α-methylnoradrenaline had only a weak depressant action, and that the depressions do not represent a non-specific depression by noradrenergic of the neuronal membrane.
Abstract: Noradrenaline and pharmacologically related substances have been applied to identified pyramidal tract cells in the cerebral cortex of rats anaesthetised usually with urethane. 64% of these cells were depressed by noradrenaline, and this response could be potentiated by iproniazed. It could also be blocked occasionally by phentolamine, and more frequently by propranolol, and was mimicked closely by isoprenaline. α-methylnoradrenaline had only a weak depressant action. This specific blockade of noradrenaline depressions, suggests that noradrenaline may be acting on receptors resembling β-receptors in the periphery, and that the depressions do not represent a non-specific depression by noradrenaline of the neuronal membrane. There was no correlation between cells responding to noradrenaline and cells responding to thalamic, transcallosal or epicortical stimulation. Noradrenaline is therefore concluded not to be a transmitter in pathways from these sites.
TL;DR: In this article, the ground state molecular geometry of CHD 2 CCH was determined from ground state combination differences, from which A 0 values were derived using microwave estimates of B 0 and C 0.
TL;DR: In this paper, the influence of light and dark on the respiration rate, sugar level, and rubidium uptake of the roots of young sunflower and barley plants has been investigated.
Abstract: The influence of light and dark on the respiration rate, sugar level, and rubidium uptake of the roots of young sunflower and barley plants has been investigated. The rate of root respiration was found to be closely correlated with the rate of carbohydrate transport from the shoots. This enabled the energy required for root growth to be calculated. A period of darkness caused a reduction in rubidium uptake and transport which appeared to be due to the reduced rate of root metabolism in the dark. The experiments of some earlier workers on the effect of transpira tion on rubidium uptake by young sunflower and barley plants were repeated. The results indicated that they were studying the metabolic effect of light and dark on salt uptake as well as the effect of transpiration.
TL;DR: Large differences exist within a single genus between species with the same diploid chromosome number, for example, a three-fold range in the genus Lathyrus4 and between five and seven times as much nuclear DNA in Vicia faba as in V. sativa.
Abstract: THERE is widespread variation between species of higher plants in amounts of nuclear DNA. In ten species a fifty-seven-fold variation in amounts of DNA per nucleus for equivalent cells was recorded1 and later reports showed wide ranges in the DNA contents of diploid species within single families (forty-fold in the Ranunculaceae2 and sixty to eighty-fold in the Droseraceae3). Most strikingly, large differences exist within a single genus between species with the same diploid chromosome number, for example, a three-fold range in the genus Lathyrus4 and between five and seven times as much nuclear DNA in Vicia faba as in V. sativa5–7. The structural basis of these variations is unclear although models of either a single stranded chromosome, in which DNA content increases by longitudinal multiplication of DNA sequences, or a multi-stranded chromosome, where increase is by lateral increase of strands, have been suggested (see reviews, refs 8, 9).
TL;DR: Li2CaSiO4 and Li2CaGeO4 as discussed by the authors are isostructural and have body-centered tetragonal unit cells, with dimensions a = 5.047 ± 0.005, c = 6.486 ± 0.,006 A, and a = 6,141 ± 0,0.002 A, respectively.
TL;DR: These sources of error have been insufficiently appreciated in the past and while it is possible to determine the growth rate of the fetal skull the time interval necessary to measure this with a clinically realistic degree of confidence is not less than three weeks.
TL;DR: Evidence suggests that competition for nutrients in droplets on leaves may limit germination of spores of pathogens and the effect on the growth of saprophytic micro-organisms.
Abstract: The release of diffusible substances from plant leaves, fungal spores or from pollen into water droplets on the surface of leaves is discussed in relation to (1) direct and indirect effects on spores of pathogens and (2) the effect on the growth of saprophytic micro-organisms. Evidence suggests that competition for nutrients in droplets on leaves may limit germination of spores of some pathogens. Modification of the chemical environment of leaf surfaces by saprophytic micro-organisms is discussed in relation to lytic enzyme and antibiotic production, cuticle degradation, production of growth substances and fixation of nitrogen.
Examples are given of the effect on pathogenic fungi of diffusible toxins from leaves and inhibitors associated with surface wax. Treatments of leaves that remove or reduce surface wax can result in a stimulation of spore germination of some pathogenic fungi. The possible occurrence of phytoalexins on leaf surfaces prior to entry of pathogens into leaves is discussed in relation to differences in host-pathogen interaction.
TL;DR: Auditory thresholds were determined by a modified method of limits under 10 intensities of light (patterned or homogeneous).
Abstract: Auditory thresholds were determined by a modified method of limits under 10 intensities of light (patterned or homogeneous). An analysis of variance of the data showed significant results for intensity conditions, personality type and the interaction of these parameters. Auditory sensitivity increased under weak, and decreased under strong, intensities of light in introverts. It increased under all intensities in extraverts, with greater increase at greater intensities, and increased under weak and medium intensities in ambiverts. The EPI E, but not N, scale scores and sensitivity increases correlated positively, at medium and strong intensities of light.
TL;DR: There is a markedly higher proportion of D -glucopyranuronosyl than of 4- O -methyl- D -Glucopyrsyl residues in leaf and stem tissues at all stages of maturity in wheat plants.