Showing papers by "Queen's University Belfast published in 1985"
TL;DR: In this paper, the ability of Fuller's earth to adsorb a basic dye (Astrazone Blue) and an acidic dye (Telon Blue - Acid Blue 25) has been studied.
Abstract: The ability of Fuller's earth to adsorb a basic dye (Astrazone Blue — Basic Blue 69) and an acidic dye (Telon Blue - Acid Blue 25) has been studied. The equilibrium saturation adsorption capacities were 1200 mg dye g−1 Fuller's earth and 220 mg dye g−1 Fuller's earth for Astrazone Blue and Telon Blue, respectively. The kinetics of the adsorption processes were studied in an agitated batch adsorber. The time to reach 90% equilibrium value was achieved in less than 1 h. The variables investigated were agitation, adsorbent mass, initial dye concentration and temperature. A limited number of studies were undertaken using a fired clay but significantly lower saturation capacities were obtained, namely, 7 mg dye g−1 fired clay and 40 mg dye g−1 fired clay for Telon Blue and Astrazone Blue, respectively.
349 citations
TL;DR: In this paper, the authors measured CH3C1 production by a common wood-rotting fungus, and reported that on glucose-based media, the chloride ion (Cl−) at concentrations 90% efficiency.
Abstract: Globally, at least 5 Mt yr−1 of chloromethane (CH3Cl) must originate from natural sources, according to estimates based on environmental concentrations, man-made emissions of 26 kt yr−1 being insignificant in comparison1–3. Although CH3C1 is a natural product of several fungal species4,5, no quantitative investigations of its biological production have been reported. We have measured CH3C1 production by a common wood-rotting fungus, and report that on glucose-based media, the chloride ion (Cl−) at concentrations 90% efficiency. The pattern of CH3C1 biogenesis was typical of a secondary metabolite and paralleled loss of Cl− from the medium. With cellulosic substrates, CH3C1 yields ranged between 80 and 95% at Cl− concentrations as high as 25 mM, although production extended over a longer period. Bromo- and iodomethane were formed in high yield from the corresponding halide ions. Such high-efficiency methylation of the halide ion indicates that fungi could make a substantial contribution to the atmospheric CH3C1 burden.
218 citations
TL;DR: In this article, the ability of activated carbon to adsorb various pollutants from aqueous solutions has been studied, including phenol, p-chlorophenol, sodium dodecyl sulphate, mercuric ions and chromic(III) ions.
182 citations
TL;DR: Eleven rhesus monkeys monitored intensively during experimental infection with Ebola virus showed prominent neutrophilia with left shift and lymphopenia were the earliest abnormalities and were statistically significant by day 4, whereas in vitro platelet aggregation was markedly depressed, progressing rapidly to complete failure by the time of maximum illness.
Abstract: Eleven rhesus monkeys were monitored intensively during experimental infection with Ebola virus. Prominent neutrophilia with left shift and lymphopenia were the earliest abnormalities and were statistically significant by day 4 (P less than .02 and P less than .01, respectively). By day 4 falls in platelet counts were not statistically significant, whereas in vitro platelet aggregation was markedly depressed, progressing rapidly to complete failure by the time of maximum illness. Intraplatelet protein studies suggested this event was the result of in vivo activation and degranulation. Coagulation cascade defects were mainly in the intrinsic system and were surprisingly mild, with no evidence of selective consumption or production deficit of factor VII or VIII. When the possibility of indirectly mediated damage to endothelium possibly by a nonspecific immune response was examined, weight loss was less severe in drug-treated monkeys, and all had detectable plasma prostacyclin metabolites, but there was no improvement in survival.
178 citations
TL;DR: The photosynthesis of green and brown algae with thin thalli decreased in green light, but species with thick thalli from these two groups had action spectra which were almost flat, and matched the optical blackness of the thalli but did not reflect the pigment differences between the species.
Abstract: Net photosynthesis at 10μmol photons m-2 s-1 in each of 24 wavelengths was measured in absolute units by an O2-electrode and corrected for dark respiration to construct action spectra for gross photosynthesis in nine species of algae, which included plants with thin and thick thalli from each of four major pigment groups. The photosynthesis of green and brown algae with thin thalli decreased in green light, but species with thick thalli from these two groups had action spectra which were almost flat, and matched the optical blackness of the thalli but did not reflect the pigment differences between the species. Among the red algae, on the other hand, there was little difference between the action spectra for thin and thick algae. Only wavelengths absorbed by the phycobilin pigments were effective in photosynthesis, even in species (e.g. Chondrus, Phyllophora) which absorbed all visible wavelengths strongly. Maximal quantum yields of 0.10 to 0.12 O2 molecules per absorbed photon were recorded for thin green and brown algae, but thicker algae in these two groups had lower values. Red algae exhibited maximal values close to 0.10 O2 molecules per absorbed photon, irrespective of thallus thickness or phycocyanin content, but the quantum yields of phycoerythrin-rich species in the 600 to 650 nm waveband were lower than those of phycocyanin-rich species.
140 citations
TL;DR: It was found that increased WHC, as measured by swelling ratio in both raw and cooked meat, markedly influenced cooked meat tenderness, irrespective of the connective tissue content of the muscles.
135 citations
TL;DR: It is essential that further consideration should be given to the possibility that hyperinsulinemia is often present in diabetes, either in relation to mild glucose intolerance or obesity (in noninsulin-dependent diabetes mellitus) or because of insulin therapy (in insulin-dependentabetes mellitus).
Abstract: The suggestion that insulin is associated with atherosclerosis is based on clinical, epidemiologic, and experimental evidence. In general, atherosclerosis of the coronary, cerebral, and peripheral arteries is associated with abnormally high insulin responses to oral glucose. This hyperinsulinemia is not related to acute injury or to tissue necrosis, does not occur in response to intravenous glucose or tolbutamide, and is independent of other cardiovascular risk factors. Populations who are at high risk for cardiovascular disease have higher insulin responses to oral glucose than those at lower risk. Prospective studies carried out in Australia, Finland, and France have shown that elevated insulin levels, either fasting or in response to oral glucose, have a predictive role in the development of cardiovascular disease. This association is independent of the effects of other cardiovascular risk factors. In experimental animals, insulin deficiency retards the development of diet-induced arterial disease, whereas administration of insulin promotes lesion development and prevents lesion regression. Insulin stimulates lipid synthesis in isolated arteries and stimulates proliferation and lipid accumulation in cultured arterial smooth muscle cells. The evidence linking insulin with atherosclerosis has been gathered from nondiabetic subjects; this evidence is unavailable in diabetics. As it is clear that hyperinsulinemia is often present in diabetes, either in relation to mild glucose intolerance or obesity (in noninsulin-dependent diabetes mellitus) or because of insulin therapy (in insulin-dependent diabetes mellitus), it is essential that further consideration should be given to the possibility that hyperinsulinemia may have harmful effects on the arterial wall.
135 citations
TL;DR: The main peak of immunoreactive material in pancreas, as measured by the pancreatic polypeptide carboxy-terminal radioimmunoassay, eluted considerably earlier than standard peptide YY, neuropePTide Y and bovine pancreaticpolypeptides, and is probably identical to rat pancreaticPolypeptid.
129 citations
TL;DR: The dietary-induced increase in longevity resulting from a retardation of the ageing process(es) appears to be associated with an enhanced turnover of proteins during the major portion of the life span of dietary restricted rats.
109 citations
TL;DR: A broad range of substituted aromatic nitriles were attacked with a general preference being shown for those with meta substitution for the conversion of p-hydroxybenzonitrile to p-Hydroxybenzoic acid and ammonia without intermediate formation of the amide.
108 citations
TL;DR: Cluster analysis carried out on the time diary data revealed four distinct life-styles, namely Active, Social, Domestic and Passive, with ANOVAS indicating significant differences between time spent on behaviours typical of each cluster.
Abstract: The research aimed at identifying variation in how the unemployed spend their time One hundred and twenty-one unemployed men in the 25 to 45 age range completed time diaries, questionnaires and Goldberg's 12-item GHQ Cluster analysis carried out on the time diary data revealed four distinct life-styles, namely Active, Social, Domestic and Passive, with ANOVAS indicating significant differences between time spent on behaviours typical of each cluster A significant relationship between psychological well-being (as measured by the GHQ) and life-style was identified with a progressive decline in mental health being paralleled by decreasing activity and withdrawal into the home Profiles of men typical of each cluster in terms of personal characteristics such as marital status, age, size and age of family, social support and employment history were outlined, Of such background characteristics only social support was significantly related to GHQ scores The interrelationship between life-style, psychological well-being and background factors is discussed and the implications of the findings outlined
TL;DR: It is shown that family diversity rose with time, and in particular from the Cretaceous to the present day, and the present evidence does not support the view that mass extinctions are statistically distinguishable from background extinctions.
Abstract: The fossil record of non-marine tetrapods (amphibians, reptiles, birds and mammals) has been described by numerous authors1–3, and major ecological replacements, mass extinctions and adaptive radiations have been identified. However, most of these features of the large-scale evolution of tetrapods have been noted without numerical data of the kind assembled for marine invertebrates4–10, marine vertebrates7–10 and vascular land plants11. Much has been learnt from the record of marine invertebrates, particularly about the overall patterns of diversification with time, the performance of different major taxonomic groups at different times, and the magnitude and timing of mass extinctions. The present study tests some of the general conclusions on the basis of a new compilation of data on the fossil record of terrestrial tetrapods. I show that family diversity rose with time, and in particular from the Cretaceous to the present day. There were several mass extinction events, but none of these was associated with a statistically high extinction rate. The extinction events, including the famous terminal Cretaceous extinction, were the result of a slightly elevated extinction rate combined with a depressed origination rate, and the present evidence does not support the view that mass extinctions are statistically distinguishable from background extinctions. Further, the record of non-marine tetrapods shows an increasing total extinction rate and an only marginally decreasing probability of extinction (per-taxon rate) from the late Devonian to the present, the opposite of the findings from the record of marine animals.
TL;DR: In this article, the R-matrix method was used to calculate the collision strengths of four Be-sequence ions, C III (2.6-8.0 Ry), O V (4.4-12.0Ry), Ne VII (8.4−20.0 this article ), and Si XI (11.0−34.0
TL;DR: The pharmacokinetics of midazolam were studied in surgical patients given 0.3 mg kg-1 i.v. for either the induction of anaesthesia, or postoperative sedation following cardiopulmonary bypass.
Abstract: The pharmacokinetics of midazolam were studied in surgical patients given 0.3 mg kg-1 i.v. for either the induction of anaesthesia, or postoperative sedation following cardiopulmonary bypass. The short elimination half-life of midazolam (2.4 h in patients less than 50 yr undergoing minor surgery) was significantly, although not markedly, prolonged with age (4.1 h in patients greater than 50 yr undergoing minor procedures) and by the nature of the operation (3.8 h after major operative procedures). These changes were the result of alterations in clearance and volume of distribution with age, and in volume of distribution with nature of operation.
TL;DR: Cell loss and regeneration were investigated and compared in the retinal microvasculature of age- and sex-matched normal and streptozotocin diabetic rats, characterized by changes in the pericyte to endothelial cell ratio in retinal capillaries isolated for microscopy by the trypsin digest technique.
TL;DR: The effects of ruthenium red, lanthanum, fluorescein isothiocyanate and trifluoperazine, all antagonists of Ca2+ function in cells, have been studied in growing pollen tubes of Tradescantia virginiana, and the hypothesis that Ca2+.
Abstract: The effects of ruthenium red, lanthanum, fluorescein isothiocyanate and trifluoperazine, all antagonists of Ca2+ function in cells, have been studied in growing pollen tubes of Tradescantia virginiana. All four drugs inhibit pollen-tube growth but bring about different ultrastructural changes at the growing tips and within the cytoplasm. The results strongly support the hypothesis that Ca2+ plays a vital role in the mechanism of pollen-tube tip growth. The effect of ruthenium red provides evidence that sequestration of Ca2+ by mitochondria critically adjusts the concentration of these ions at tube tips. Fluorescein isothiocyanate appears to be a potent inhibitor of vesicle fusion at the plasma membrane, with vesicles accumulating in the tip at rates equivalent to those determined previously for their production. Both vesicle fusion and tip extension are regulated by Ca2+ but appear to be independently controlled processes.
TL;DR: Herpes simplex virus Type I in tissue culture showed cytopathic effects on cellular membranes of Vero cells and erythrocytes; therefore, it is suggested that inactivation of virus results from insertion of the glycones into the viral envelope.
TL;DR: In Chlorella and Chlamydomonas two periods of relatively constant duration determine total cell cycle length and cell size is stabilised by control of whether 2, 4, 8 or 16 daughter cells are formed by an influence of mother cell mass.
Abstract: Summary
In Chlorella and Chlamydomonas two periods of relatively constant duration determine total cell cycle length and cell size is stabilised by control of whether 2, 4, 8 or 16 daughter cells are formed. A timer runs through G1 phase and leads to the attainment just before S phase of a commitment to divide without further requirement for growth. The commitment timer requires growth for its continuation, is stabilized against a raising or lowering of temperature between 20 and 30°C but it is only partly stabilized against slow growth due to low energy supply. In Chlamydomonas 137c, at 25°C when growth is limited by light energy, the period between the beginning of growth in fully formed daughter cells and the attainment of first commitment to divide approximates to 5 + 0.75 × doubling time (h), at protein doubling times between 5 and 25 h. Under the same conditions division processes occurring in the period after first commitment also confer time properties since they are completed in 6 h. Postcommitment events are extended in the first cycle following a temperature reduction but develop temperature compensation in the second cell cycle. The mean generation time of Chlamydomonas 137c approximates to 11 + 0.75 × mass doubling time (h).
In both algae cell size is stabilized by an influence of mother cell mass on the number of successive further commitments that can occur following first commitment to divide. Each commitment is to perform a single further round of DNA replication and achieve a further doubling of cell number without further requirement for growth. Comparison of cells of different size when growing at the same rate shows that time, not size, controls the start of division events, and that size and not growth rate determines division number. In Chlamydomonas, division numbers provide a constant mean apportionment of 20 pg Lowry positive material to committed daughter cells at the time of final commitment. It is proposed that commitments continue until the mass available for further apportionment falls below a critical minimum of 27 pg, therefore, the minimum apportionment will be 13.5 pg and the maximum 27 pg per committed daughter ceDs. This predicted twofold range of cell sizes is confirmed by cell size frequency measurements made by microscopy and by fluorescence-activated cell sorting. Size frequency measurements made after growth intermediate between 2, 4 or 8 in a cell cycle are consistent with increments of commitment under size control. Multiple fission cell cycles are compared with others.
TL;DR: It is concluded that, because immobilization in the lengthened position does not increase EMG activity in either extensor or flexor muscles, passive stretch appears to be the factor mainly responsible for mitigating the effects of disuse in this situation.
TL;DR: Although the method is relatively simple, determination of absolute blood flow in these vessels has little clinical potential because of inherent measurement inaccuracies.
TL;DR: Results were affected by the different bacterial types, the nature of the attachment surface and the substances in which the bacteria were suspended with a Moraxella-like species, stainless steel and lactose and non-casein protein solutions respectively resulting in greatest numbers of cells attaching.
Abstract: Glass, rubber and stainless steel surfaces were exposed to various types of bacteria in the presence of milk and a number of milk components under both static and agitated incubation conditions. Numbers of bacteria attaching were enumerated by epifluorescence microscopy. Results were affected by the different bacterial types, the nature of the attachment surface and the substances in which the bacteria were suspended with a Moraxella-like species, stainless steel and lactose and non-casein protein solutions respectively resulting in greatest numbers of cells attaching. Agitation had no marked influence on attachment.
TL;DR: Azomethine ylides are readily generated from imines of α-amino acid esters by a formal 1,2-H shift as discussed by the authors, and a suitably positioned unactivated double or triple bond in either of the two precursors of the imines leads to an intramolecular cycloaddition generating fused ring systems in good yield.
TL;DR: In this paper, two approaches to the prediction of the Wells turbine performance are described, both of which are based on the two-dimensional cascade theory and isolated aerofoil data.
Abstract: Analytical and experimental studies of the effect of geometric and aerodynamic variables on the performance of the Wells self-rectifying air turbine are presented in this paper. Two approaches to the prediction of the Wells turbine performance are described, both of which are based on the two dimensional cascade theory and isolated aerofoil data. Experimental results are based on the investigations in Unidirectional and oscillating airflow rigs. Comparisons are made on the analytical and experimental results.
TL;DR: The entire coding region of the polymerase-associated (P) protein gene of canine distemper virus has been sequenced and considerable homology is seen at both the nucleotide and protein sequence level.
TL;DR: In this article, the authors described two experiments that together overcome this problem and found that relative crab size influences all stages of shell fights including pre-fight display, escalation, eviction and examination of the opponent's shell by the victor both before and after eviction of the loser.
TL;DR: It is indicated that intra- and interspecific competition may occur among the gill parasites and the direction and speed of ventilation water-currents and certain intrinsic factors of the parasite themselves may determine their microhabitat restriction on the gills.
TL;DR: In this paper, the modulus of the normal polar Kerr coefficient for a multilayer system containing a single magnetic film was derived using the Fresnel differential approach, and the resulting formula determined how much superior optimized quadrilayers are than simpler bilayer structures, and also how the signal to noise ratio depends on the fundamental optical constants of the magnetic film.
Abstract: The Fresnel differential approach is used to derive a formula for the modulus of the normal polar Kerr coefficient for a multilayer system containing a single magnetic film. This particular function of the magneto-optical effect is chosen since it invariably appears in expressions for the signal-to-noise ratio associated with first order effects. The resulting formula determines how much superior optimized quadrilayers are than simpler bilayer structures, if at all; and also how the signal-to-noise ratio depends on the fundamental optical constants of the magnetic film.
TL;DR: In this paper, four rock types (basalt, sandstone, granite, and chalk) are examined with respect to the maximum surface temperatures which they experience when subjected to similar conditions of exposure.
Abstract: Four rock types (basalt, sandstone, granite, and chalk) are examined with respect to the maximum surface temperatures which they experience when subjected to similar conditions of exposure. Rock temperature measurements are reported for an urban environment and for two experimental situations in which an infrared lamp is used to simulate heating under cold and hot conditions. Differences in rock temperatures are discussed with reference to thermal rock properties (albedo, specific heat capacity, and thermal conductivity). Some natural situations are suggested in which thermal rock properties could conceivably play a role in determining the extent to which rocks would be affected by particular weathering processes.
01 Jan 1985
TL;DR: In this article, a new mathematical model for calculating the behavior of unsteady gas flow in engine manifold junctions of any configuration is described, which allows for pressure losses at any configuration.
Abstract: This paper describes a new mathematical model for calculating the behaviour of unsteady gas flow in engine manifold junctions of any configuration. The model, which allows for pressure losses at th...
TL;DR: Naked crabs use the minor cheliped to investigate shells in preference to the majorCheliped, which is normally used by housed crabs, with the major Cheliped being reserved for defence by naked crabs.