Showing papers by "Queen's University Belfast published in 1987"
TL;DR: In this paper, the adsorption of four dyestuffs, namely, Basic Blue 69 (BB69), Basic Red 22 (BR22), Acid Red 114 (AR114) and Acid Blue 25 (AB25), onto bagasse pith has been studied.
246 citations
TL;DR: In this paper, a substantial part of the literature and attempt an amalgamation of ideas and a simplification of some terms used in the widespread writings on this subject are reviewed, together with, in the second part, discussion on origin, the models of formation and flow mechanics.
Abstract: we review a substantial part of the literature and attempt an amalgamation of ideas and a simplification of some terms used in the widespread writings on this subject. Problems of identification, classification, and terminology are covered, together with, in the second part, discussion on origin, the models of formation and flow mechanics. The significance of rock glacier studies, expecially with respect to palaeoenvironmental reconstruction, is also reviewed.
228 citations
TL;DR: An iterative thinning algorithm reduces a two-dimensional pattern of strokes to its skeleton by removing layers of edge elements until each stroke has unit thickness, indicating an improvement of over 40 percent.
Abstract: An iterative thinning algorithm reduces a two-dimensional pattern of strokes to its skeleton by removing layers of edge elements until each stroke has unit thickness. A parallel solution requires the independent calculation of new values for each iteration, using a window of nearest neighbors for each element. The traditional need for at least two subiterations can be avoided by modifying the window to permit the availability of intermediate calculations. Timings on an ICL DAP (an array processor) indicate an improvement of over 40 percent. Additional refinements are suggested to reduce noise in the final skeleton.
193 citations
TL;DR: Competition in microevolution: The Red Queen and the effects of interspecific competition on community structure.
Abstract: (4) Evolutionary trends . . . . . . . . . . . . . ( 5 ) Increased effectiveness of adaptation . . . . . . . . . . . . . . . . . . . . . ( I ) Competition and natural selection . . . . . . . . . . (2) The evolutionary effects of interspecific competition . . . . . . . (3) The effects of interspecific competition on community structure . . . . . . . . . . . . . . . ( I ) Extinction and competition . . . . . . . . . . . (2) The Red Queen . . . . . . . . . . . . . . I11 . Competition in microevolution
170 citations
TL;DR: Chitosan has been prepared from prawn shell and crab shell chitin this article, and the molecular weight, tensile strength, elongation at the break, and hydrophilic properties are extremely dependent on the degree of deacetylation achieved when chitins is hydrolyzed to chitosin.
Abstract: Chitosan has been prepared from prawn shell and crab shell chitin. The molecular weight of the material derived from prawn shells is higher than that obtained from crab shell. The molecular weight, tensile strength, elongation at the break, and hydrophilic properties of chitosan are extremely dependent on the degree of deacetylation achieved when chitin is hydrolyzed to chitosan. Graft copolymers have been prepared with chitosan and a series of vinyl monomers using both heterogeneous and homogeneous reaction conditions. The hydrophilic properties of chitosan can be modified by blending with poly(vinyl alcohol).
160 citations
151 citations
Book•
21 Sep 1987TL;DR: The Odyssey is told through the stories of Odysseus, Penelope, and the Suitors, with a conclusion that can be read as either a call for vengeance or a plea for peace.
Abstract: Chapter 1. Recognition and the Return of Odysseus Chapter 2. Odysseus and the Suitors Chapter 3. Recognition and Hospitality Chapter 4. Penelope Chapter 5. Recognition and Song Chapter 6 Conclusion
123 citations
TL;DR: It is suggested that the optimal time (relative to female moult) of entry into precopula varies as a function of both male and female size, and large males enter into Precopula earlier than small males and prefer to take a large female to a small female.
117 citations
TL;DR: In this paper, the authors of military manuals in the Roman empire were considered more as a source of historical anecdote than as an object of serious study in its own right, which raises questions about their scope and purpose and about what use could be or was made of them.
Abstract: Normally, little attention is paid to the authors of military manuals in the imperial period. ‘Entertaining though trifling’ is a comment that can generally be heard. Frontinus is more familiar than most because of his distinguished career and other writings, but even his Strategemata is considered more as a source of historical anecdote than as an object of serious study in its own right. Yet the military textbooks fit into the tradition of didactic literature in antiquity and as such raise questions about their scope and purpose, and about what use could be or was made of them. This has special significance in relation to generalship and the evolution of tactics in the Roman empire.
112 citations
TL;DR: The effects of increasing oral doses of caffeine on effective renal plasma flow (ERPF), plasma renin activity (PRA), serum electrolytes, plasma noradrenaline, blood pressure and heart rate were studied in eight healthy male volunteers.
Abstract: The effects of increasing oral doses of caffeine (45, 90, 180 and 360 mg) on effective renal plasma flow (ERPF), plasma renin activity (PRA), serum electrolytes, plasma noradrenaline, blood pressure and heart rate were studied in eight healthy male volunteers. Urine volume was increased by 360 mg of caffeine only. At caffeine doses greater than 90 mg urinary sodium excretion was significantly increased. There were no changes in ERPF. Serum potassium was significantly reduced by 360 mg of caffeine. Caffeine increased systolic pressure in a dose related manner. Diastolic pressure was also increased, but not in relation to dose. A 360 mg dose of caffeine produced a late increase in heart rate. These changes were not associated with any alterations in PRA or in plasma noradrenaline.
TL;DR: The results confirm that the 20-MST is a valid field test of cardio-respiratory endurance and suggest that it can additionally be used to predict relative running performance over 10 km.
Abstract: The aim of this study was to assess the validity of a 20 metre multi-stage shuttle run (20-MST) as both a field test of cardiorespiratory endurance and as a predictor of competitive performance in a 10 kilometre (10 km) race. Nine male subjects (age 35.4 +/- 5.8 years) (mean +/- SD) underwent a laboratory test of maximum oxygen uptake on a treadmill (VO2 max 59.0 +/- 9.9 ml.kg.-1min-1), completed the 20-MST (score 105 +/- 23.7 laps/11.4 +/- 2.7 paliers) and competed in a 10 km race (finishing time 41.8 +/- 7.3 minutes). Analysis using Pearson's Product Moment Coefficient revealed high correlations between these variables (20-MST vs. VO2 max, r = 0.93; 20-MST vs. 10 km, r = -0.93; VO2 max vs. 10 km, r = -0.95). These results confirm that the 20-MST is a valid field test of cardio-respiratory endurance and suggest that it can additionally be used to predict relative running performance over 10 km.
TL;DR: Carnosol might prove useful as a food antioxidant which could also contribute to the retardation of the microbial spoilage of foods.
TL;DR: In this paper, a new R -matrix theory of electron-atom and electron-molecule scatter-ing at intermediate energies is described, where both the outer valence electron of the target atom or molecule and the scattered electron are expanded in terms of a continuum R-matrix basis.
Abstract: A new R -matrix theory of electron-atom and electron-molecule scattering at intermediate energies is described. In this theory both the outer valence electron of the target atom or molecule and the scattered electron are expanded in terms of a continuum R -matrix basis. This enables target eigenstates as well as pseudostates representing inelastic effects to be accurately represented in an internal region. In addition, a two-dimensional R -matrix propagator approach is developed that enables the internal region to be subdivided and highly excited target states that extend out to large distances to be treated. This new theory is then combined with the T -matrix energy averaging technique introduced earlier by Burke et al . (1981) to yield accurate cross sections at intermediate energies. The method is illustrated by applying it to the elastic s-wave scattering of electrons by atomic hydrogen from threshold to 60 eV.
TL;DR: Rat pups born by Caesarean section, when tested immediately after birth, preferred their mother's fluid to that of an unrelated rat, indicating that this preference is acquired prenatally.
TL;DR: Because satisfactory plasma concentration effect relationships have been difficult to establish for most clinical indications, and little dose-related toxicity is seen, plasma β-adrenoceptor antagonist concentration measurement is usually unnecessary.
Abstract: The beta-adrenoceptor antagonists have been widely used clinically for over 20 years and their pharmacokinetics have been more thoroughly investigated than any other group of drugs. Their various lipid solubilities are associated with differences in absorption, distribution and excretion. All are adequately absorbed, and some like atenolol, sotalol and nadolol which are poorly lipid-soluble are excreted unchanged in the urine, accumulating in renal failure but cleared normally in liver disease. The more lipid-soluble drugs are subject to variable metabolism in the liver, which may be influenced by age, phenotype, environment, disease and other drugs, leading to more variable plasma concentrations. Their clearance is reduced in liver disease but is generally unchanged in renal dysfunction. All the beta-adrenoceptor antagonists reduce cardiac output and this may reduce hepatic clearance of highly extracted drugs. In addition, the metabolised drugs compete with other drugs for enzymatic biotransformation and the potential for interaction is great, but because of the high therapeutic index of beta-adrenoceptor antagonists, any unexpected clinical effects are more likely to be due to changes in the kinetics of the other drug. Because satisfactory plasma concentration effect relationships have been difficult to establish for most clinical indications, and little dose-related toxicity is seen, plasma beta-adrenoceptor antagonist concentration measurement is usually unnecessary. The investigation of the clinical pharmacokinetics of the beta-adrenoceptor antagonists has added greatly to our theoretical and practical knowledge of pharmacokinetics and made some contribution to their better clinical use.
TL;DR: IFN (500 IU ml-1) inhibited cell proliferation and the combination of this treatment with tamoxifen (2 microM) had a greater anti-proliferative effect than either drug alone although there was no evidence of synergism.
Abstract: Exposure of ZR-75-1 human breast cancer cells for 48 h to human recombinant interferon alpha (IFN alpha) resulted in increased expression of oestrogen receptors as measured in a whole cell binding assay. This effect was inversely proportional to dose being significant following treatment with 10-100 IU IFN ml-1 and was only observed at a low initial cell plating density. The extent of the increase in oestrogen receptor levels ranged from 1.2- to 7.2-fold following treatment with 10 IU IFN ml-1. No increase in progesterone receptor expression was observed under the same experimental conditions. Concentrations of IFN which increased oestrogen receptor levels had no effect on cell proliferation. IFN (500 IU ml-1) inhibited cell proliferation and the combination of this treatment with tamoxifen (2 microM) had a greater anti-proliferative effect than either drug alone although there was no evidence of synergism. However, a 5-day pretreatment of cells with IFN (10 IU ml-1) markedly sensitised them to the growth-inhibiting effect of a subsequent 6-day exposure to tamoxifen.
TL;DR: The data indicate that reduced hepatic clearance is the most likely explanation for the increased mean absolute bioavailability of midazolam after cimetidine, and that this is not a result of enhanced midAZolam absorption.
Abstract: Cimetidine has been shown to inhibit the oxidative metabolism of a variety of low- and high-extraction drugs. Despite the findings of initial investigators, there is evidence that ranitidine may exert similar effects. Eight healthy volunteer subjects took part in a within-subject crossover study. They received midazolam, 15 mg, by mouth after pretreatment with cimetidine, ranitidine, or nothing and midazolam, 10 mg, intravenously on separate occasions. Mean absolute bioavailability of midazolam was increased by more than 30% after cimetidine (P less than 0.01) and 26% after ranitidine (P less than 0.05). The data, which agree with a concurrent clinical study indicating greater hypnotic action of midazolam after ranitidine, indicate that this is not a result of enhanced midazolam absorption and that reduced hepatic clearance is the most likely explanation.
TL;DR: In this paper, the desorption and regeneration of eight dye colours individually from six low-cost sorbent materials were investigated, including Rice husk, bark, cotton waste and hair.
TL;DR: Taurolin, a non-antibiotic antimicrobial agent, significantly reduced the adherence of buccal and vaginal strains of Candida albicans blastospores and urine isolates of Escherichia coli and Staphylococcus saprophyticus to epithelial cells.
Abstract: Taurolin, a non-antibiotic antimicrobial agent, significantly reduced the adherence of buccal and vaginal strains of Candida albicans blastospores and urine isolates of Escherichia coli and Staphylococcus saprophyticus to epithelial cells. Light microscopy and radio-isotopic counting methods were used to quantify the adherence of the micro-organisms to either uroepithelial or buccal epithelial cells. A maximum reduction in adherence of approximately 65% was obtained. The anti-adherence capacity was time-dependent, requiring a contact time of 30 min to achieve maximum effect. Taurolin at sub-minimum inhibitory concentrations (MIC) significantly reduced the adherence of Candida and E. coli. A concentration slightly higher than the MIC was required for Staph. saprophyticus. Treatment of either epithelial cells or micro-organisms with Taurolin resulted in reduced adherence of microorganisms.
TL;DR: The F1 proteins of six paramyxoviruses are compared and shown to have substantial conservation of those residues important in the maintenance of tertiary structure of this protein.
TL;DR: Epicoccum purpurascens inhibited colony growth of Phytophthora spp and Pythium spp in culture more than other species tested and was more sensitive to the epicorazine fraction than to flavipin.
Abstract: Epicoccum purpurascens inhibited colony growth of Phytophthora spp and Pythium spp in culture more than other species tested. Six antifungal compounds were detected in cultures of E. purpurascens grown in two selective media. Four of these compounds, epicorazines A and B and two compounds (X and Y) of unknown identity (designated the epicorarine fraction) were produced simultaneously at an early stage in the growth of E. purpurascens in a sucrose plus casamino acid medium but were not detected in a glucose plus (NH4HPO4 medium. The compound flavipin was detected in both media but was preferentially produced in the latter. A third unidentified antifungal compound was detected in both media at a late growth stage. Mycelial growth of Pythium spp was more sensitive to the epicorazine fraction than to flavipin. Phytophthora spp tended to be more sensitive to flavipin. Both were much less toxic to mycelial growth of Fusarium oxysporum f.sp. lini. Flavipin inhibited germination of zoospores of Phytophthora cinnamomi and oogonia of Pythium intermedium. Mycelia of Phytophthora spp and Pythium spp antagonized by E. purpurascens were stunted and swollen and where opposing cultures intermingled hyphae of E. purpurascens coiled and penetrated those of the two pathogens. Cellulase and β, 1–3 glucanase activities were detected in cultures of E. purpurascens grown on Phytophthora or Pythium spp hyphal wall material as the sole carbon source.
TL;DR: Cardiovascular side effects indicate a proarrhythmic effect similar to that with other Class I drugs, occasional precipitation of congestive heart failure and conduction abnormalities; the latter two occur more often in patients with underlying ventricular dysfunction.
Abstract: Propafenone is a Class I antiarrhythmic agent with weak beta-adrenoceptor antagonist activity which can be given both intravenously and orally. Dosage must be individualised because of dose-dependent pharmacokinetics, a wide range of clinically effective plasma concentrations (64 to 3271 micrograms/L) after comparable doses, the presence of an active metabolite (5-hydroxy-propafenone) and genetically determined metabolic oxidation. In non-comparative studies propafenone 450 and 900 mg/day orally significantly suppressed premature ventricular complexes and couplets in 96% and 75% of patients, respectively, and abolished ventricular tachycardia in 75% of patients. Efficacy was confirmed in placebo-controlled studies in which propafenone 300 to 900mg daily suppressed premature ventricular complexes (greater than 80%) in 77% of patients; 87% of patients had significant reductions in couplets and abolition of ventricular tachycardia. In patients with ventricular arrhythmias refractory to other antiarrhythmic agents, propafenone 450 to 1200 mg/day suppressed arrhythmias in 63% of patients (in long term therapy 66%). Electrically induced arrhythmias were prevented by intravenously administered propafenone in 12 to 23% of patients. However, long term oral therapy was effective in 77% of patients selected using programmed electrical stimulation. Propafenone was also effective in suppressing atrial and AV nodal/junctional re-entrant tachycardias and Wolff-Parkinson-White tachycardias involving accessory pathways. A limited number of comparisons with other antiarrhythmic drugs indicate that the antiarrhythmic efficacy of propafenone is superior or similar to that of quinidine, disopyramide and tocainide, and comparable to that of lignocaine (lidocaine), flecainide and metoprolol against ventricular arrhythmias and a smaller number of atrial arrhythmias. Cardiovascular side effects indicate a proarrhythmic effect similar to that with other Class I drugs, occasional precipitation of congestive heart failure and conduction abnormalities; the latter two occur more often in patients with underlying ventricular dysfunction. Non-cardiovascular side effects (neurological, gastrointestinal) are well tolerated and generally resolve with continued therapy or dosage reduction. Thus, propafenone is an effective antiarrhythmic agent, and is a useful addition to currently available drugs, although further studies will be required to determine clearly its place in therapy compared with more established antiarrhythmic drugs.
TL;DR: A contextual reading of this theory is crucial, all the more so because so few problems in the history of human geography have been contextually interrogated by the discipline's historians,' and because the more specificdebates about human acclimatization cannot be divorced from theories about acclim atization in general.
Abstract: Could the natives of a temperate climate colonize and increase in a tropical country and vice versa?" "Can Europeans become acclimatized in tropical Africa?" "Is the colonization of tropical Africa by Europeans possible?" "Can the white race become acclimatized in the tropics?"! These questions the titles of articles published in a variety of scholarly journals serve to introduce a subject that engaged the attention of many geographers and medical practitioners throughout the nineteenth and well into the twentieth century, namely, the possibility of human acclimatization. It was a topic that was widely discussed during the period, and yet for all the attention and publicity it received at the time, not to mention the diverse reactions it provoked, it has been almost totally ignored by historians of geographical thought. Even when it does surface in their writings, as with T. W. Freeman, little is said beyond the observation that "such questions as the way of life of European settlers in the tropics and their powers of acclimatization are of considerable interest". This conspicuous omission is doubly unfortunate, firstly, because the problems of human acclimatization were so widely debated in science, and secondly, because the questions it raises intersect intellectually, institutionally and ideologically with a range of important topics in the history of science more generally. For these reasons alone a contextual reading of this theory is crucial, and all the more so because so few problems in the history of human geography have been contextually interrogated by the discipline's historians,' and because the more specificdebates about human acclimatization cannot be divorced from theories about acclimatization in general.
TL;DR: The results suggest that the effects of external forces on lymph flow are more dependent on compression of tissues in the lymphatic drainage area than on compression on the main lymphatic ducts.
Abstract: 1. Pressure fluctuations and lymph flow were measured in metatarsal lymphatics in anaesthetized sheep. 2. Intermittent compression significantly increased lymph flow when this was applied over the hoof but did not increase flow significantly when applied over the metatarsal region. 3. In a second preparation a 15 cm length of metatarsal lymphatic was cannulated at both ends and measurements were made of the ability of the duct to pump saline from an inflow reservoir through an outflow at the same height. 4. In the absence of external forces fluid was propelled by the lymphatic's intrinsic contractions but when intermittent compression was applied over the metatarsal region flow increased almost fourfold. 5. When animals with the doubly cannulated duct were allowed to recover, the effect of normal limb movements on fluid propulsion was examined. Under these conditions flow only occurred in response to intrinsic lymphatic contractions and appeared to be unaffected by the animal moving round the cage. 6. These results suggest that the effects of external forces on lymph flow are more dependent on compression of tissues in the lymphatic drainage area than on compression of the main lymphatic ducts. External compression can increase fluid propulsion by these vessels but, since forces of adequate magnitude appear not to be encountered in normal hind-limb movements, lymph propulsion in this region must depend on intrinsic lymphatic pumping.
TL;DR: This report deals with the problems associated with a high incidence rate of methicillin-resistant Staphylococcus aureus in low birth weight infants in a regional special care baby unit in Northern Ireland.
TL;DR: Two key projects initiated at the Royal Signals and Radar Establishment and carried out in collaboration with a number of major electronics companies and several universities demonstrate clearly that the systolic approach to system design is not just an academic concept but a practical means of exploiting large amounts of parallelism and hence achieving orders of magnitude improvement in performance for digital signal processing (DSP).
Abstract: For the last five or six years, there has been an active program of research on systolic array processors (SAPs) in the United Kingdom. In this article, the authors describe two key projects initiated at the Royal Signals and Radar Establishment (RSRE) and carried out in collaboration with a number of major electronics companies and several universities. The success of these projects demonstrates clearly that the systolic approach to system design is not just an academic concept but a practical means of exploiting large amounts of parallelism and hence achieving orders of magnitude improvement in performance for digital signal processing (DSP). This type of application not only demands but also fully utilizes the SAP architecture. The first project was aimed at developing an electronic processor capable of computing the vector of complex weights required to form the receive beam for an adaptive antenna array.
TL;DR: In this paper, the rate coefficients for this removal process are obtained, for certain limiting assumptions about the excitation mechanism, and the coefficients are found to be in good agreement with those deduced from an independent analysis of ground-based observations.
TL;DR: Higher titers of antibodies to measles virus envelope antigens, hemolysin and hemagglutinin, Epstein-Barr virus capsid antigen and nuclear antigen, and rubella virus hemag GLUTinin were demonstrated in serum samples of patients with multiple sclerosis and rheumatoid arthritis than in age- and sex-matched control subjects.
Abstract: • Higher titers of antibodies to measles virus envelope antigens, hemolysin and hemagglutinin, Epstein-Barr virus (EBV) capsid antigen and nuclear antigen, and rubella virus hemagglutinin were demonstrated in serum samples of patients with multiple sclerosis and rheumatoid arthritis than in age- and sex-matched control subjects. A significant correlation was observed between antibodies to measles and rubella viruses both in patients with multiple sclerosis and rheumatoid arthritis, but such a correlation was not observed between antibodies to EBV and measles or rubella viruses. Whether elevated levels of antibodies to EBV are due to reactivation of the virus, or elevated levels of antibodies to all the enveloped viruses result from cross-reactions between viruses and host tissue, or perhaps reflect defects in immunoregulation, needs further investigation.
TL;DR: The results indicate that catecholamines may not have a specific role in aggressive behaviour, rather, they may act more to excite or inhibit general behavioural systems, although certain treatments do have a Specific influence on aggressive behaviour.