Showing papers by "University of Birmingham published in 1983"
TL;DR: In this article, an alternative zeta (ζ) calibration approach is described, which circumvents absolute φ and λf evaluation: each dosimeter glass is calibrated repeatedly against zircon age standards from the Fish Canyon and Bishop tuffs, the Tardree rhyolite and Southern African kimberlites, to obtain empirical calibration factors ζ.
1,400 citations
556 citations
TL;DR: A novel procedure in which the HRP-catalysed luminescence of a cyclic hydrazide is multiplied severalfold by the addition of a synthetic component of the firefly bioluminescent system, D-luciferin.
Abstract: Present luminescence assays for horseradish peroxidase (HRP) have limitations. Here we report a novel procedure in which the HRP-catalysed luminescence of a cyclic hydrazide (such as luminol) is multiplied severalfold by the addition of a synthetic component of the firefly bioluminescent system, D-luciferin (4,5-dihydro-2-(6-hydroxy-2-benzothiazolyl)-4-thiazole-carboxylic acid). The specific enhancement of HRP-catalysed light emission from cyclic hydrazides should extend the sensitivities of luminescently monitored assays, which have already been shown to be as sensitive as those using radioactive labels1,2. This procedure has been applied to the immunoassay of serum α-fetoprotein, thyroxine, digoxin, hepatitis B surface antigen, immunoglobulin E and rubella virus antibody.
337 citations
TL;DR: In leaf derived callus cultures of Solanum laciniatum Ait both phenolics and solasodine concentrations increased when medium phosphate or nitrogen concs were reduced to one-eighth or when sucrose concentration was increased, and growth was inhibited by sucrose depletion and nitrogen supple -mentation.
Abstract: In leaf derived callus cultures of Solanum laciniatum Ait. both phenolics and solasodine concentrations increased when medium phosphate or nitrogen concs. were reduced to one-eighth or when sucrose concentration was increased from 3 to 4–8 %. Under these conditions growth was reduced and final FW:DW fell. Growth was inhibited by sucrose depletion and nitrogen supple -mentation. On additional nitrogen the concentrations of phenolics and protein significantly increased, FW:DW was reduced and solasodine concentration was unaffected. In seedling derived cultures phosphate depletion resulted in a significant increase in phenolics concentration, an inhibition of growth and a rise in solasodine concentration.
331 citations
TL;DR: In this article, a methodology for calculating the distribution of gains and losses from a policy change using data for a large sample of households is discussed, based on the equivalent income function, which is money metric utility defined over observable variables.
320 citations
TL;DR: The results show that high titres of FGF are present in the developing brain long before myelination commences, and that normal levels of F GF are found in the brains of leukodystrophic mice which have no myelin.
Abstract: Standard parasagittal lesions were placed stercotactically in the cerebral hemispheres of neonatal and adult rats in order to compare scarring in the immature and mature animal. Lesions were examined by light and electron-microscopy and immunofluorescence to study the astrocyte reaction, collagen deposition, and the formation of the basement memebrane of the glia limitans.
281 citations
TL;DR: In this paper, the authors present an analysis of recent data on friction and drag on quantized vortices in helium II and deduce values of the phenomenological and microscopic coefficients of friction on vortex lines and rings over a wide range of temperatures at the saturated vapor pressure.
Abstract: We present an analysis of recent data on friction and drag on quantized vortices in helium II. From these data, we deduce values of the phenomenological and microscopic coefficients of friction on vortex lines and rings over a wide range of temperatures at the saturated vapor pressure. We demonstrate that the microscopic parameters are unusually sensitive to the input data. We include brief discussions of the vortex core parameter, and present the results of precision fits of a number of thermodynamic and transport properties of He II which are used in mutual friction calculations.
242 citations
TL;DR: In this paper, the authors analyse the strategic causes and the economic spin-off effects of military expenditure in less developed countries and show that defence burden in LDCs may be analysed principally in terms of strategic factors such as security and threat, and is determined relatively autonomous of economic factors.
212 citations
TL;DR: In this article, profile refinement of powder neutron diffraction data has been used to examine the structure of γ-Fe 2 O 3 and to evaluate covalence effects for octahedral and tetrahedral Fe 3+ ions within the structure.
209 citations
TL;DR: During voluntary diving in tufted ducks there is a balance between the cardiovascular responses to forced submersion and to exercise in air (tachycardia and vasodilatation in active muscles), with the bias towards the latter.
Abstract: In six tufted ducks there was a linear relationship between heart rate and oxygen consumption when swimming at different velocities.Mean oxygen consumption at mean duration of voluntary dives was 3.5 times resting and not significantly different from that at maximum sustainable swimming speed. Contrary to an earlier report (Prange & Schmidt-Nielsen, 1970), leg beat frequency increased with increased swimming speed. Although heart rate at mean dive duration was 51 % higher than the resting value, it was a significant 59 beats min −1 lower than predicted from the heart rate/oxygen consumption relationship obtained during swimming. This relationship is, therefore, of no use for predicting oxygen consumption from heart rate during diving, nor incidentally during transient changes during air breathing. It is concluded that during voluntary diving in tufted ducks there is a balance between the cardiovascular responses to forced submersion (bradycardia, selective vasoconstriction) and to exercise in air (tachycardia and vasodilatation in active muscles), with the bias towards the latter.
164 citations
TL;DR: Gait and balance measures were undertaken in 11 elderly ambulant patients suffering from senile dementia of Alzheimer type of moderate severity and in an equal number of healthy non-demented age- and sex-matched controls, consistent with the view that transcortical pathways participating in the integration of gait are damaged in senile Alzheimer type.
Abstract: Measures of gait and balance were undertaken in 11 elderly ambulant patients suffering from senile dementia of Alzheimer type of moderate severity, and in an equal number of healthy non-demented age- and sex-matched controls. Valid results were obtained in nine pairs. Compared with the controls the demented patients had significantly shorter step length, lower gait speed, lower stepping frequency, greater step-to-step variability, greater double support ratio and greater sway path. The findings are consistent with the view that transcortical pathways participating in the integration of gait are damaged in senile dementia of Alzheimer type. The findings may help to explain the increased incidence of falls in patients with brain failure.
TL;DR: Because CRF does not alter the distribution, elimination, or clearance of unbound midazolam, changes in the pharmacodynamic profile of midazolate in CRF patients, if they exist, are more likely due to inherent alterations in drug sensitivity than to pharmacokinetic changes.
Abstract: Fifteen patients with chronic renal failure (CRF) were given midazolam 02 mg/kg iv over 15 s All but one lost consciousness in a time ranging from 22-100 s (mean +/- SD was 55 +/- 26 s) after drug administration Patients regained consciousness from 6-105 min (mean 53 +/- 32) after drug administration The calculated mean plasma level of midazolam at arousal was 81 +/- 47 ng/ml Pharmacokinetics parameters were determined from midazolam plasma levels measured in 16 consecutive venous blood samples The pharmacokinetic parameters in CRF patients were compared with those of healthy volunteers matched for age, sex, and body size with the CRF patients Protein binding was determined by equilibrium dialysis CRF patients had a significantly higher (P less than 0005) plasma-free drug fraction (65% +/- 07) compared with the control patients (39% +/- 01) Total (bound plus unbound) kinetics differed in the two groups: volume of distribution 38 +/- 3 1/kg in CRF patients versus 22 +/- 2 1/kg in controls (P less than 0001), and clearance 114 +/- 16 ml X min-1 X kg-1 in CRF patients versus 67 +/- 09 ml X min-1 X kg-1 in controls (P less than 002) When kinetic parameters were corrected for protein binding, CRF patients unbound volume of distribution (635 +/- 68 1/kg) and free drug clearance (189 +/- 29 ml X min-1 X kg-1) were not different from the control group's volume of distribution (556 +/- 57 1/kg) and free drug clearance (176 +/- 24 ml X min-1 X kg-1)(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: Both naloxone and naltrexone abolished the preference for a highly palatable 0.05% sodium saccharin solution in rats that had been adapted to a 22 hr water-deprivation schedule, interpreted in terms of a drug-induced blockade of the natural reward ofhighly palatable fluids in thirsty rats.
TL;DR: A new analysis of Lower and Middle Jurassic bivalve faunas of western North America and the southern Andes in comparison to Europe, supported by evidence from other molluscs, casts further light on the establishment of a “central Atlantic” epicontinental seaway prior to the formation of a true oceanic strait as mentioned in this paper.
TL;DR: In this paper, it was shown that the information matrix test introduced by White (1982) is a score test for parameter constancy, which leads to a simple computational procedure for calculating the Information Matrix test, for a sample of n observations, n times the R2 from the least squares regression of a column of ones on a matrix whose elements are functions of 1st and 2nd derivatives of the log density function.
01 Jan 1983
TL;DR: In this article, the procedures of biometrical genetics (Mather and Jinks 1971, 1977, 1982) are used to define and analyse heterosis in terms of the actions and interactions of genes of the kinds that are well established in classical Mendelian genetics.
Abstract: In this chapter the procedures of biometrical genetics (Mather and Jinks 1971, 1977, 1982) will be used to define and analyse heterosis in terms of the actions and interactions of genes of the kinds that are well established in classical Mendelian genetics. Quantitative models, experimental designs and statistical analyses will be described that can accommodate all kinds of gene action and interaction at any number of loci in the presence of any level of linkage disequilibrium and genotype x environment interaction and apportion their contributions to heterosis.
TL;DR: Results show that antibody scanning is greatly improved by using 111In as the radiolabel in place of 131I and should allow the detection of smaller or deeper lesions.
Abstract: Immunoglobulin G (IgG) antibodies to carcinoembryonic antigen (CEA) were labelled with radioactive indium (111In) or iodine (131I) and a comparison made of their value in locating CEA producing tumours. Eleven patients given 111In-anti-CEA had 31 tumours as judged by a combination of all techniques. Of these, 28 were detected by 111In-anti-CEA and 26 by conventional clinical techniques. Five of the patients also received 131I-anti-CEA. These patients had 15 tumour areas. Thirteen were detected by 111In and eight by 131I. 111In also produced a better signal to noise ratio in the scans and thereby showed lesions with greater certainty. In addition, the 111In isotope continued to accumulate in the tumour areas for considerably longer than 131I. Absorbed doses (whole body) were similar for both isotopes. The results show that antibody scanning is greatly improved by using 111In as the radiolabel in place of 131I and should allow the detection of smaller or deeper lesions.
TL;DR: Under conditions in which membrane potential (Δψ) was the sole contributor to the proton-motive force, the steady-state rate of ATP synthesis in chromatophores increased disproportionately when Δ ψ was increased: the rate had an approximately sixth-power dependence on Δψ.
TL;DR: In this paper, the authors compared calcites and dolomites from the late Precambrian Bonahaven Formation of Scotland with other published data and found that calcites exhibit luminescence when MnCO3>0.03 wt % (dolomite) or > 0.06 wt percent (calcite) and FeCO3<2-2-5 wt percentage (dollomite).
Abstract: Calcites and dolomites from the late Precambrian Bonahaven Formation of Scotland exhibit luminescence when MnCO3>0.03 wt % (dolomite) or >0.06 wt % (calcite) and FeCO3<2-2-5 wt % (dolomite). Comparison with other published data shows close similarity in the position of Fe-quenching in dolomite, but more variability in the position of Mn-activation in calcites and dolomites and the onset of Fe-quenching in calcites. These anomalies are thought to relate to chemical controls subsidiary to the dominant factors of Fe and Mn concentration. It is not practical to make a useful comparison between operating conditions of different luminescence instruments because of differences in design and an inability to measure routinely the current actually on the specimen surface.
TL;DR: The accumulation of a phenolic material which is alkali-insoluble, enzyme resistant and chlorine dioxide extractable indicates that lignification occurs in necrotic cells of the hypersensitive response.
Abstract: Fluorescence microscopy, histochemistry and autoradiography all indicated the cellular accumulation of phenolic compounds during hypersensitive necrosis induced by Puccinia graminis f. sp. tritici in resistant wheat cultivars. Hypersensitivity and phenolic accumulation were observed in near-isogenic lines carrying the Sr 5 or Sr 6 (at 19°C) alleles for resistance, but not in the susceptible reactions of the parent cultivar Marquis ( sr 5, sr 6), or the Sr 6 line when tested at 26°C. Toluidine blue staining and fluorescence microscopy indicated the accumulation of a phenolic material in hypersensitively necrotic cells. Removal of wall-bound phenolic acids with hot alkali caused little loss in fluorescent intensity, but subsequent delignification with chlorine dioxide reduced fluorescence to negligible levels. Autoradiography, using the lignin precursors [ 3 H]-phenylalanine and [ 14 C]-cinnamic acid, showed incorporation of label into cytoplasmic regions of necrotic and degenerating host cells, corresponding to the sites of autofluorescence and histochemical staining. [ 3 H]-Phenylalanine incorporated into healthy cells and fungal structures was lost from both resistant and susceptible tissue on alkali treatment, but some label was retained in necrotic cells. Necrotic regions from infected resistant cultivars were resistant to cell wall degrading enzymes, but extraction of lignin allowed subsequent tissue maceration. The accumulation of a phenolic material which is alkali-insoluble, enzyme resistant and chlorine dioxide extractable indicates that lignification occurs in necrotic cells of the hypersensitive response. A role for cellular lignification as an induced barrier is postulated and its direct or indirect effect on fungal growth in resistant tissue is discussed.
TL;DR: Ring scission was, under these conditions, a minor metabolic pathway resulting in the excretion of small amounts of 3-hydroxybenzoic acid, 3-Hydroxyhippuric acid and3-hydroxyphenylpropionic acid.
Abstract: Following administration of a single dose of [U14C]cyanidanol-3 to human volunteers, a mean of 55% of the dose of 14C was excreted in urine; 90% of urine 14C was excreted within 24 h of drug administration. The major urinary metabolites were the glucuronides of (+)-catechin and 3'-O-methyl-(+)-catechin, and the sulphate of the latter. These three conjugates collectively accounted for three quarters of urine 14C. Urinary excretion of unchanged (+)-cyanidanol-3 was 0.1-1.4% dose. (+)-Cyanidanol-3 and metabolites containing the intact flavanol ring system accounted for 90% of urine 14C. Ring scission was, under these conditions, a minor metabolic pathway resulting in the excretion of small amounts of 3-hydroxybenzoic acid, 3-hydroxyhippuric acid and 3-hydroxyphenylpropionic acid. Unchanged (+)-cyanidanol-3 was detected in plasma between 30 min and 12 h after administration. Metabolites (as total 14C) persisted in plasma for at least 120 h after administration.
TL;DR: A single-session procedure to assess an individual's most preferred level of a factor in a product is justified theoretically and illustrated by the results for salt concentration in samples of bread and tomato soup tested on 30 young men who had had no previous experience of the task.
TL;DR: Waddell's method of estimating protein concentration by the difference between spectrophotometric absorptions has been reexamined and is probably as accurate a measure of total protein as measurement by nitrogen analysis, with the advantage of being nondestructive.
TL;DR: A vast number of potential applications are already known, and one of the most interesting applications may be in continuous fermentation such as ethanol production by immobilized living microorganisms.
Abstract: Although the application of the natural attraction of many microorganisms to surfaces has been applied in vinegar production since the early 1980s, and has long been utilized in waste water purification, the development of microbial cell immobilization techniques for special applications dates back only to the early 1960s. The immobilization may involve whole cells, cell fragments, or lysed cells. Whole cells may retain their metabolic activity with their complex multienzyme systems and cofactor regeneration mechanisms intact, or they may be killed in the process with only a few desired enzymes remaining active in the final biocatalyst. Cells may also be coimmobilized with an enzyme to carry out special reactions. Although relatively few industrial scale applications exist today, some are of very large scale. Current applications vary from relatively small scale steroid conversions to amino acid production and high fructose syrup manufacture. A vast number of potential applications are already known, and one of the most interesting applications may be in continuous fermentation such as ethanol production by immobilized living microorganisms. 373 references.
TL;DR: No relationship was found between the ability of any human keratinocyte strain or line the authors studied to metabolically inactivate PMA and their resulting response to the compound, and the mechanism of action of PMA as a promoter of epidermal carcinogenesis.
Abstract: We have studied the action of phorbol, 12-myristate, 13-acetate (PMA) on human keratinocytes grown with lethally-irradiated 3T3 cells using medium supplemented with hydrocortisone, cholera toxin and epidermal growth factor. Normal keratinocyte cultures show a heterogeneous response to PMA; 90-93% of the colony-forming cells lose their colony-forming ability and form cornified envelopes when treated for 24 h with doses of 100 nM or less, but the remainder are resistant to doses of 1000 nM. The resistant cells are the precursors of the sensitive ones and heterogeneity is restored to those cells and their progeny after 8 days culture in the absence of PMA. Cultures of 3 squamous cell carcinoma lines, a SV40-transformed human keratinocyte line, and three clones of these lines were found to contain 3-17 times more PMA-resistant keratinocytes than the normal strains, and the size of the PMA-resistant fraction in each line was inversely related to the competence of that line to lose colony-forming efficiency when placed in suspension culture (which is the first detectable change in an ordered programme of events resembling terminal differentiation of the keratinocyte). The number of cells with cornified envelopes in surface cultures of normal human keratinocytes increased from approximately 3% in control cultures to approximately 70% in those treated for 6 days with 100 nM PMA. The transformed human keratinocyte cultures showed a 3-25-fold smaller increase in cornified envelope formation when treated with 100 nM PMA, and the increase in envelope formation by each line when exposed to this dose of PMA was related to the competence of that line to lose cloning efficiency in suspension culture. No relationship was found between the ability of any human keratinocyte strain or line we studied to metabolically inactivate PMA and their resulting response to the compound. The results are discussed in relation to the mechanism of action of PMA as a promoter of epidermal carcinogenesis.
TL;DR: In this paper, the authors view the labour market experience of individuals as a process of movement between the states of employment and unemployment and examine this dependence and its implications for the interpretation of estimates of models of labour market behaviour.
Abstract: In this paper we view the labour market experience of individuals as a process of movement between the states of employment and unemployment. We note that there are three main ways of sampling members of the labour force namely sampling the members of a specific state, sampling the people entering or leaving a state and sampling the population regardless of state. The joint distribution of observable and unobservable characteristics of individuals depends on the mode of sampling adopted. We examine this dependence and its implications for the interpretation of estimates of models of labour market behaviour.
TL;DR: Transmission of immunoglobulin (Ig) classes and subclasses from mother to foetus and to neonate, and the survival of maternal Ig in the circulation of the young mouse up to 40 days after birth, has been quantitated in Balb/c homozygous and (Balb/ c X SJL/J)F1 matings.
TL;DR: It is argued that relatively small changes in the extent of reduction of ubiquinone, or of another component of the respiratory chain with similar redox potential, critically determine the capacity for reducing nitrate and the mechanism by which electron flow to oxygen or nitrous oxide inhibits nitrate reduction in cells is investigated.
TL;DR: The morphology and microanatomy of two different phases in the life history of a single new marine choanoflagellate (Proterospongia choanojuncta sp.nov.) have been documented and described with the aid of light microscopy and from electron microscopy.
Abstract: The morphology and microanatomy of two different phases in the life history of a single new marine choanoflagellate (Proterospongia choanojuncta sp.nov.) have been documented and described with the aid of light microscopy and from electron microscopy of whole mounts and sections of material in clonal culture. Completion of the life-cycle has been repeatedly achieved in cultures established from single cells, regardless of which phase is used as a starting point. One phase is colonial and motile (the Proterospongia phase) and the other unicellular and sedentary (the Choanoeca phase). Taxonomic, nomenclatural and developmental problems are summarized and discussed.