Showing papers by "Keele University published in 1977"
TL;DR: In this article, the abundance and distribution of selected minor and trace elements (Ti, Zr, Y, Nb, Ce, Ga and Sc) in fresh volcanic rocks can be used to classify the differentiation products of subalkaline and alkaline magma series in a similar manner to methods using normative or major-element indices.
4,648 citations
TL;DR: The advantages of steady-state EP recording include speed in assessing sensory function in normal and sick infants, objective measurement at very high suprathreshold levels where psychophysical methods are difficult or ineffective, and proving a speedy objective equivalent to behavioral test in animals.
Abstract: The advantages of steady-state EP recording include (1) speed in assessing sensory function in normal and sick infants (e.g., in amblyopia) and in sick adults (e.g., in multiple sclerosis); (2) monitoring certain activities of sensory pathways that do not intrude into conscious perception; (3) rapidly assessing sensory function when a large number of subjects must be tested (e.g., in refraction); (4) objective measurement at very high suprathreshold levels where psychophysical methods are difficult or ineffective; (5) rapidly assessing sensory function in normal subjects when EP variability and nonstationarity preculde lengthy experiments; and (6) providing a speedy objective equivalent to behavioral test in animals.
275 citations
TL;DR: It is concluded that, since simple cells are unresponsive to noise, they cannot provide the sole input to complex cells, and tells against the hypothesis that they act as a second stage in the abstraction of edge-orientation in cortical information-processing.
Abstract: The responsiveness of 254 simple and complex striate cortical cells to various forms of static and dynamic textured visual stimuli was studied in cats, lightly anaesthetised with N2O/O2 mixtures supplemented with pentobarbitone.
180 citations
TL;DR: A simple resampling technique is presented that extends the range of designs to conversions between any two rates and can vary slightly as in a practical situation where the input signal and output signal are under the control of autonomous clocks.
Abstract: Filtering is necessary in decimation (decreasing the sampling rate of) or interpolation (increasing the sampling rate of a digital signal. If the rate change is substantial, the process is more efficient when the decimation or interpolation occurs in stages rather than in one step. Half-band filters are particularly efficient for effecting octave changes in sampling rate and nine digital filters are presented, eight of them half-band filters, to be used as components of multistage interpolators and decimators. Also presented is a procedure for combining the filters to produce multistage designs that meet a very wide range of accuracy requirements (stopband attenuation to 77 dB, passband ripple as low as 0.00014). The nine filters admit changes between sampling rates above 4W, where W is the nominal bandwidth of the signal. Established design techniques may be used to obtain efficient filters for conversion between 4W Hz sampling and 2W Hz, the "baseband sampling rate." With these multistage filters, the possible interpolation and decimation ratios are all integer multiples of powers of two. To overcome this restriction we present a simple resampling technique that extends the range of designs to conversions between any two rates. The interpolation or decimation ratio need not be an integer or even rational. In fact, it can vary slightly as in a practical situation where the input signal and output signal are under the control of autonomous clocks. We demonstrate the approach by means of several design examples and compare its results with those obtained from the optimization scheme of Crochiere and Rabiner.
121 citations
TL;DR: The glycogen-lead correlation suggests that the metabolism of contaminated chloragocytes is directed towards lead sequestration, though differing nutritional states cannot be ignored.
Abstract: The lead content of whole earthworms, highest in contaminated site specimens, was significantly higher inDendrobaena rubida thanLubricus rubellus and a species difference in zinc was also recorded. Selective feeding and differential absorption are discounted and a species difference in maximum tolerance to body lead is suggested. Copper was low in all specimens. Chloragocytes and intestinal tissue showed significantly higher lead levels in contaminated earthworms than in control material. Ultrastructurally, chlorgocytes from contaminated earthworms showed electron dense flecks associated with the chroragosome peripheries and within the debis vesicles. Very fine flecks occurred in the nuclei, but mitochondria and Golgi were indistinguishable from control material. Preliminary X-ray microanalysis of contaminated chloragocytes revealed lead and phosphorus. The deposits within the chloragocytes might represent unbound lead precipitated by phosphate buffer; flecks being absent from contaminated, citrate buffered material and from control material. The chloragosomes are proposed as possible sites for sequestered lead. Chloragocyte and intestinal glycogen levels were significantly higher in control material where the chloragocyte cytoplasm was rich in α-glycogen rosettes, these being absent from lead contaminated cells. The glycogen-lead correlation suggests that the metabolism of contaminated chloragocytes is directed towards lead sequestration, though differing nutritional states cannot be ignored.
121 citations
TL;DR: A more situationally specific locus of control measure specially designed to take into consideration the environmental circumstances as well as interests of the subject population being studied is used, included in the measure is a desire of outcome index which added substantially to the validity coefficient.
Abstract: In two studies, positive self-concept correlated with belief in one's internal locus of desired control. Examining only institutionalized subjects, the first study found this relationship to be particularly prominent for male subjects (r = .68). In the second study, comparing institutionalized persons sampled from several homes for the aged and noninstitutionalized elderly, this relationship was once again most prominent for the institutionalized males (r = .53). Among these studies internality also correlated positively with nurses' rating of subject's happiness, self-ratings of contentment and happiness, and correlated negatively with length of residency in old age home and age. In response to concerns raised by Rotter (1975) over locus of control research and issues raised by Mischel (1968, 1973) and others concerning personality research in general, the present study used a more situationally specific locus of control measure specially designed to take into consideration the environmental circumstances as well as interests of the subject population being studied. Included in the measure is a desire of outcome index which added substantially to the validity coefficient.
113 citations
TL;DR: This paper found that the presence of structural markers increased span, and tended to cause span to extend exactly to a phrase boundary, although it also tended to lead to span reaching the phrase boundary.
Abstract: Keyboard musicians sight-read passages of music in which the amount of information about the presence of phrase units was systematically varied. A distinction was made between ‘physical’ unit markers, which allowed delineation of a unit prior to analysis of its component elements, and ‘structural’ unit markers, which defined a unit in terms of the sequential rules obeyed by its constituent elements. During the execution of the passages the text would be removed at a point known in advance only to the experimenter. Subjects were then required to execute all the material seen beyond this point to provide a measure of the eye-hand span at that point. It was found that the presence of structural markers increased span, and tended to cause span to extend exactly to a phrase boundary. The presence of physical markers did not increase span, although it also tended to cause span to extend exactly to a phrase boundary. The results suggest a clear analogy between the cognition of music and language, in that knowledge of abstract structure is of importance in the organization of immediate visual processing of text.
93 citations
TL;DR: A few well-preserved, well-dated faunas suggest that Ordovician, Silurian, Devonian and Carboniferous systems may each possess characteristic Radiolaria populations.
Abstract: A few well-preserved, well-dated faunas suggest that Ordovician, Silurian, Devonian and Carboniferous Systems-may each possess characteristic Radiolaria populations, with a major change in fauna occurring in the Upper Silurian or Lower Devonian. Known Paleozoic and post-Paleozoic taxa appear to be wholly unrelated.
79 citations
TL;DR: Giant cross-bed sets, up to 40 m thick, are the major channel infilling facies as mentioned in this paper, with maximum depths of over 40 m, have been cut into the top of a coarsening upward sequence, in the Upper Carboniferous of northern England.
Abstract: Channels, with maximum depths of over 40 m, have been cut into the top of a coarsening upward sequence, in the Upper Carboniferous of northern England. The channels are interpreted as deep, distributaries cut into delta slope deposits.
Giant cross-bed sets, up to 40 m thick, are the major channel infilling facies. Internal erosion surfaces occur within the giant cross-beds and some are draped by micaceous, silty sandstone. Previously interpreted as deltaic sedimentation units, the cross-beds are now thought to have been produced mainly by side attached, alternate bars and the drapes are interpreted as low stage deposits.
Cosets of medium scale cross-beds overlie the giant cross-beds. These are thought to be deposits of dunes and smaller bars on top of the transverse bars and in the shallower parts of the distributary. The giant cross-beds are commonly underlain by unlaminated sandstone but may be underlain by undulatory bedding. The latter was apparently produced by ridges, parallel to the current, spaced between 9 and 23 m apart.
The north of England appears to have had a major river by present day standards, for at least part of the upper Carboniferous.
77 citations
76 citations
TL;DR: The discharge regimes that occur in modern rivers vary chiefly with climate as discussed by the authors, where there are large sand waves in a river, these show different responses to flow changes of different speeds and magnitudes.
Abstract: The discharge regimes that occur in modern rivers vary chiefly with climate. Where there are large sand waves in a river, these show different responses to flow changes of different speeds and magnitudes. A rapid fall of discharge leaves bed forms stranded in the river, with flow around the front eroding the slip faces. With a slower rate of fall, smaller superimposed sand waves produce groups of convex-upward erosion surfaces within tabular cross-bedded sets. With a very slow fall and pronounced low-stage reworking, the sand waves are largely dissected.
01 Oct 1977
TL;DR: In this paper, a mechanism is proposed by which high still water levels due to high astronomical tides, onshore storm force winds and allied wave surge, promote shoaling characteristics and beach profile changes which are conducive to spilling breaker development at tidal extremities.
Abstract: One of the major problems of shingle beach dynamics is the method by which coarse gravel is transferred from beach face to storm beach, the latter often lying several metres above high spring tidal levels. The mechanism which is usually proposed, cites the action of plunging breakers as being central to this problem of sediment transfer. However, the nature of net residual fluid force of plunging breakers is deemed unsatisfactory for any substantial upbeach (onshore) sediment transport during storm conditions on gravel beaches. A mechanism is proposed by which high still water levels due to high astronomical tides, onshore storm force winds and allied wave surge, promote shoaling characteristics and beach profile changes which are conducive to spilling breaker development at tidal extremities. It is the net onshore fluid force vector of the spilling breaker overtopping the beach crest which may be the cause of extreme sedimentation events on the storm beach. An example of such sediment transfer is given for a known storm beach sedimentation event at Llanrhystyd gravel beach, West Wales, during February 1974. Process variables were monitored on several days allowing the use of an inshore breaker steepness criterion, to indicate positions in the tidal regime where plunging breakers give way to spilling forms. This example serves to suggest that more attention should be given to the nature and characteristics of shoaling waves, especially in respect of breaker type, when examining problems of shingle beach dynamics and sedimentation.
TL;DR: The results are compatible with the notion that generalised spike-wave activity functions as neural noise reducing the child's “rate of gain or information” or “channel capacity”.
TL;DR: In this paper, the early stages of combustion are considered for a conical premixed methane-oxygen flame of fuel-lean composition (equivalence ratio = 0.2) burning at atmospheric pressure.
TL;DR: This paper presents guide‐lines for improving instructional text under three main headings: prose and grammatical features; tables and graphs; and typographical design.
Abstract: This paper presents guide‐lines for improving instructional text under three main headings: prose and grammatical features; tables and graphs; and typographical design The paper has been printed in such a way as to illustrate some of the points being made
TL;DR: Observations suggests that the extracellular phosphodiesterase-inhibitor system of Dictyostelium might be involved in regulating the level ofextracellular cyclic AMP in cell populations prior to aggregation.
TL;DR: The effect of auditory flutter upon perceived visual frequency is possibly due to modification of a subjective criterion rather than, as previously suggested, to the entrainment or time-locking of physiological signals in the visual pathway.
Abstract: Changes in the physical rate of a clicking or fluttering sound caused changes in the rate at which a simultaneously viewed light appears to flicker, even though the physical flicker rate remains constant. Perceived flicker rate increases in response to a rate of change of flicker frequency, and this auditory 'driving' does not depend on whether the auditory and visual sources have the same location. Visual evoked potentials do not correlate with 'driving'. Thus, the effect of auditory flutter upon perceived visual frequency is not due to the properties of Morrell-type bimodal neurons, nor does it reflect the activities of neurons responsible for maintaining correspondence between perceived auditory space and perceived visual space. The effect is possibly due to modification of a subjective criterion rather than, as previously suggested, to the entrainment or time-locking of physiological signals in the visual pathway.
TL;DR: In this paper, the rate constant for the deactivation of O 2 (1 Δ g ) by molecular oxygen has been measured with the discharge flow technique using the elongated measurement section of discharge flow/shock tube.
TL;DR: Synchronous populations of secondary zoospores of an isolate of the Oomycete Saprolegnia were obtained with a temperature-shock treatment and light microscopy and serial section ultrastructural analysis provided a detailed description of their microtubular systems and the changes in these systems during the morphogenic processes which accompanied primary zoospore excystation and encystment.
TL;DR: In this article, a classification system based on their modes of formation, transportation and deposition has been developed to accommodate the inherent variability of tills, sub-division of these classifications has been carried out on the basis of their gradational characteristics.
Abstract: Summary Tills are a distinctive geological and engineering group of soils which are characterized by a wide range of behavioural patterns and a high degree of variability. As a means of identifying the various geological types of tills, a classification system based on their modes of formation, transportation and deposition has been developed. To accommodate the inherent variability of tills, sub-division of these classifications has been carried out on the basis of their gradational characteristics. Further, the fabric features contributing to variability in engineering behaviour are identified. From this, extended classifications are tentatively suggested to aid the prediction of the engineering properties of tills and the selection of the most appropriate sampling and testing techniques for them.
TL;DR: The functional significance of the helical form of the spermatozoon is considered, and the role of microtubules in spermiogenesis of annelids and other animal groups is discussed in the light of current hypotheses.
TL;DR: In this article, the authors demonstrated the enrichment of rare earth elements (REE) in the lower spilitic portion of the Bhoiwada lave profile relative to the fresh tholeiitic flow top.
Abstract: HELLMAN & Henderson1 have demonstrated the enrichment of the rare earth elements (REE) in the lower spilitic portion of the Bhoiwada lave profile relative to the fresh tholeiitic flow top. The remarkable feature of the REE distribution in the spilites was the absolute enrichment of all the elements and not only the light REE, as occasionally seen in oceanic basalts due to submarine weathering2. Thus the enhanced spilite REE destribution resembles either alkali basalt or tholeiitic differentiation products rather than tholeiitic basalt. As stated1, the high degree of REE mobility suggests that these elements must be used with caution in determining the initial magma type or volcanic environment of ancient spilitic rocks.
TL;DR: The results of five subjects showed that the saccades were directed toward the direction of the actual location of the destination rather than to that of the perceived direction.
TL;DR: It is suggested that vesicle fusion may provide the ideal occasion for removal of membrane from the vesicular compartment of the cell, and the quantity of membrane involved could be sufficiently large to suggest that release of membrane after vesicles fusion is of prime importance for membrane recycling.
TL;DR: The trail pheromone of Myrmica rubra is a volatile substance, or substances of low polarity and moderately low molecular weight, in the poison gland contents that vary with caste, age of workers, and species.
TL;DR: Findings show that catecholamines are not likely to be the afferent transmitter, and under the assumption that the drugs used reach the synaptic site, it is concluded that these drugs do not interfere with afferent synaptic transmission.
Abstract: Beta-receptor blocking agents (practolol, propranolol) and alpha-receptor blocking agents (phenoxybenzamine, phentolamine), when applied intracochlearly do not eliminate the afferetn discharges or compound action potential of the cochlear nerve. Under the assumption that the drugs used reach the synaptic site, it is therefore concluded that these drugs do not interfere with afferent synaptic transmission. Phentolamine,, however, has a toxic effect upon the cochlea independent from the synaptic process. Local application of catecholamines does not increase spontaneous activity of single fibres of the cochlear nerve. These findings show that catecholamines are not likely to be the afferent transmitter.
TL;DR: Aitken's memory is stronger than average in all respects but normal in mode of functioning as mentioned in this paper, which relates to his comprehending materials in terms of rich patterns of multiple, often recondite, properties.
Abstract: An account is given of the exceptional memory of the late Professor A. C. Aitken who was also a distinguished mathematician and mental calculator. Examples are given of his performance in memory-span tasks and his recall of artificial materials learnt under experimental conditions 27 years earlier. His memory is stronger than average in all respects but normal in mode of functioning. It relates to his comprehending materials in terms of rich patterns of multiple, often recondite, properties. Compared with Shereshevskii, another man with exceptional memory, he shows the scholar's reliance on conceptual mapping rather than the mnemonist's reliance on perceptual chaining.
TL;DR: Vocational guidance and the careers education programs which vocational theorists currently argue should span the secondary school years imply that entry into employment is the outcome of choice as discussed by the authors, which is not the case.
Abstract: Vocational guidance and the careers education programmes which vocational theorists currently argue should span the secondary school years imply that entry into employment is the outcome of choice ...