Showing papers by "Queen's University Belfast published in 2000"
TL;DR: In this paper, it has been shown that Ionic liquids, being composed entirely of ions, are green solvents, and that a wide range of chemical reactions can be performed in them.
Abstract: Ionic liquids, being composed entirely of ions, were once mainly of interest to electrochemists. Recently, however, it has become apparent that, inter alia, their lack of measurable vapor pressure characterizes them as green solvents, and that a wide range of chemical reactions (reviewed here) can be performed in them.
2,627 citations
TL;DR: The first systematic study of the effect of impurities and additives (e.g., water, chloride, and cosolvents) on the physical properties of room-temperature ionic liquids was performed in this article.
Abstract: We report here the first systematic study of the effect of impurities and additives (e.g., water, chloride, and cosolvents) on the physical properties of room-temperature ionic liquids. Remarkably, it was discovered that the viscosity of mixtures was dependent mainly on the mole fraction of added molecular solvents and only to a lesser extent upon their iden- tity, allowing viscosity changes during the course of a reaction to be entirely predictable. While the addition of such molecular solvents decreases the viscosity and density, chloride impurities, arising from the preparation of the ionic liquids, increase viscosity dramatically. The commonly used methods of preparation were validated with respect to chloride impurity.
2,105 citations
TL;DR: The genome sequence of C. jejuni NCTC11168 is reported, finding short homopolymeric runs of nucleotides were commonly found in genes encoding the biosynthesis or modification of surface structures, or in closely linked genes of unknown function.
Abstract: Campylobacter jejuni, from the delta-epsilon group of proteobacteria, is a microaerophilic, Gram-negative, flagellate, spiral bacterium—properties it shares with the related gastric pathogen Helicobacter pylori. It is the leading cause of bacterial food-borne diarrhoeal disease throughout the world1. In addition, infection with C. jejuni is the most frequent antecedent to a form of neuromuscular paralysis known as Guillain–Barre syndrome2. Here we report the genome sequence of C. jejuni NCTC11168. C. jejuni has a circular chromosome of 1,641,481 base pairs (30.6% G+C) which is predicted to encode 1,654 proteins and 54 stable RNA species. The genome is unusual in that there are virtually no insertion sequences or phage-associated sequences and very few repeat sequences. One of the most striking findings in the genome was the presence of hypervariable sequences. These short homopolymeric runs of nucleotides were commonly found in genes encoding the biosynthesis or modification of surface structures, or in closely linked genes of unknown function. The apparently high rate of variation of these homopolymeric tracts may be important in the survival strategy of C. jejuni.
1,979 citations
TL;DR: The results support prevention policies based on the classic risk factors but suggest potential for prevention beyond these, and changes in theclassic risk factors seem to partly explain the variation in population trends in CHD.
972 citations
TL;DR: The concept of social care serves to shift the centre of analysis from specific policy domains so that instead of focusing on cash benefits or services in isolation it becomes possible to consider them as part of a broader set of inter-relating elements.
Abstract: Care is now a widely-used concept in welfare state research, firmly established in the literature by feminist analysis. We believe that the concept as it has been used and developed to date has limitations that have hampered its development as a general category of welfare state analysis. In essence we argue that the political economy aspects of the concept have remained underdeveloped. The main purpose of this article is to elaborate a care-centred concept – which we name social care – that countenances and develops care as an activity and set of relations lying at the intersection of state, market and family (and voluntary sector) relations. We are especially concerned to examine what the concept of social care can tell us about welfare state variation and welfare state change and development. The article works systematically through these themes, beginning with a brief historical sketch of the concept of care and then moving on to elaborate the analytic potential of the concept of social care. In the latter regard we make the case that it can lead to a more encompassing analysis, helping to overcome especially the fragmentation in existing scholarship between the cash and service dimensions of the welfare state and the relative neglect of the latter. The concept of social care serves to shift the centre of analysis from specific policy domains so that instead of focusing on cash benefits or services in isolation it becomes possible to consider them as part of a broader set of inter-relating elements. In this and other regards, the concept has the potential to say something new about welfare states.
817 citations
TL;DR: Empirical studies show that health improvements provide a significant boost to economic growth in developing countries This leads to the view that health, like education, is a fundamental component of human capital, and suggests the notion of health-led growth as mentioned in this paper.
Abstract: Empirical studies show that health improvements provide a significant boost to economic growth in developing countries This leads to the view that health, like education, is a fundamental component of human capital, and suggests the notion of health-led growth Better health leads to higher income, but there is also a positive feedback effect, giving rise to a beneficial situation where health and income improvements are mutually reinforcing
673 citations
TL;DR: The evolution of research in luminescent signalling at Queen's University of Belfast is critically reviewed in the context of related work from the literature in this paper, where photoinduced electron transfer (PET) is found to be a robust design principle for such work.
666 citations
TL;DR: The removal efficiency of activated carbon Filtrasorb 400 (F-400) towards three highly used reactive dyes in the textile industry was investigated in this article, where the adsorption capacity data showed a high removal ability for the three reactive dye and a distinguished ability for R. Yellow.
617 citations
TL;DR: Peat has been investigated by several researchers as a sorbent for the capture of dissolved metals from wastestreams as mentioned in this paper, and the mechanism of metal ion binding to peat remains a controversial area with ion exchange, complexation, and surface adsorption being the prevalent theories.
616 citations
TL;DR: It is shown for the first time that room-temperature ionic liquids, such as 1-butyl-3-methylimi- dazolium hexafluorophosphate, [bmim][PF(6)], can be successfully used in place of conventional solvents for the liquid-liquid extraction of erythromycin-A and for the Rhodococcus R312 catalyzed biotransformation of 1, 3-dicyanob
Abstract: Organic solvents are widely used in a range of multiphase bioprocess operations including the liquid–liquid extraction of antibiotics and two-phase biotransformation reactions. There are, however, considerable problems associated with the safe handling of these solvents which relate to their toxic and flammable nature. In this work we have shown for the first time that room-temperature ionic liquids, such as 1-butyl-3-methylimi- dazolium hexafluorophosphate, [bmim][PF6], can be successfully used in place of conventional solvents for the liquid–liquid extraction of erythromycin-A and for the Rhodococcus R312 catalyzed biotransformation of 1,3-dicyanobenzene (1,3-DCB) in a liquid–liquid, two-phase system. Extraction of erythromycin with either butyl acetate or [bmim][PF6] showed that values of the equilibrium partition coefficient, K, up to 20–25 could be obtained for both extractants. The variation of K with the extraction pH was also similar in the pH range 5–9 though differed significantly at higher pH values. Biotransformation of 1,3-DCB in both water–toluene and water–[bmim][PF6] systems showed similar profiles for the conversion of 1,3-DCB initially to 3-cyanobenzamide and then 3-cyanobenzoic acid. The initial rate of 3-cyanobenzamide production in the water-[bmim][PF6] system was somewhat lower, however, due to the reduced rate of 1,3-DCB mass transfer from the more viscous [bmim] [PF6] phase. It was also shown that the specific activity of the biocatalyst in the water-[bmim] [PF6] system was almost an order of magnitude greater than in the water–toluene system which suggests that the rate of 3-cyanobenzamide production was limited by substrate mass transfer rather than the activity of the biocatalyst. © 2000 John Wiley & Sons, Inc. Biotechnol Bioeng 69: 227–233, 2000.
544 citations
TL;DR: The polarity of ambient-temperature ionic liquids based on the 1-alkyl-3-methylimidazolium cation was probed using the solvatochromic dye Nile Red as mentioned in this paper.
TL;DR: Candida antarctica lipase was shown to catalyze alcoholysis, ammoniolysis, and perhydrolysis reactions using the ionic liquids 1-butyl-3-methylimidazolium tetrafluoroborate or hexafluorophosphate as reaction media.
TL;DR: Two heterozygous insertion mutations in exon 1 of TNFRSF11A in affected members of four families with FEO or familial Paget disease of bone caused an increase in RANK-mediated nuclear factor-κB signalling in vitro, consistent with the presence of an activating mutation.
Abstract: Familial expansile osteolysis (FEO, MIM 174810) is a rare, autosomal dominant bone disorder characterized by focal areas of increased bone remodelling. The osteolytic lesions, which develop usually in the long bones during early adulthood, show increased osteoblast and osteoclast activity. Our previous linkage studies mapped the gene responsible for FEO to an interval of less than 5 cM between D18S64 and D18S51 on chromosome 18q21.2-21.3 in a large Northern Irish family. The gene encoding receptor activator of nuclear factor-kappa B (RANK; ref. 5), TNFRSF11A, maps to this region. RANK is essential in osteoclast formation. We identified two heterozygous insertion mutations in exon 1 of TNFRSF11A in affected members of four families with FEO or familial Paget disease of bone (PDB). One was a duplication of 18 bases and the other a duplication of 27 bases, both of which affected the signal peptide region of the RANK molecule. Expression of recombinant forms of the mutant RANK proteins revealed perturbations in expression levels and lack of normal cleavage of the signal peptide. Both mutations caused an increase in RANK-mediated nuclear factor-kappaB (NF-kappaB) signalling in vitro, consistent with the presence of an activating mutation.
TL;DR: The authors considers the important part played in teachers' development by different kinds of action research and concludes that although action research has a critical role to play not least as a means of building the capacity of teachers as researchers of their own practice, there has been ins...
Abstract: Two concepts that have captured the imagination of the educational community in the last 60 years have been those of ‘reflective practice’ and ‘action research’. Both, in their various forms, are considered to be critical dimensions of the professional development of teachers. However, whilst both were receiving academic attention during the 1930s and 1940s (Lewin, 1934, cited in Adelman, 1993; Lewin, 1946; Dewey, 1933), it was not until Stenhouse's (1975) notion of the teacher-as-researcher that the two came most compellingly into relationship and educational action research as a process, which held at its centre different kinds of reflection, began to be reformulated in Britain (Carr, 1993). This article considers the important part played in teachers' development by different kinds of action research. Its central thesis is that, although action research has a critical role to play not least as a means of building the capacity of teachers as researchers of their own practice, there has been ins...
Journal Article•
TL;DR: The sequence-independent detection of DNA with SYBR Green I means that it can be used to quantify the amplification of any cDNA using gene-specific primers and is ideally suited for researchers in vision science wishing to quantify mRNAs from many different genes because it does not require investment in gene- specific hybridization probes.
Abstract: Purpose To determine whether continuous monitoring of SYBR Green I fluorescence provides a reliable and flexible method of quantitative RT-PCR. Our aims were (i) to test whether SYBR Green I analysis could quantify a wide range of known VEGF template concentrations, (ii) to apply this method in an experimental model, and (iii) to determine whether 20 existing primer pairs could be used to quantify their cognate mRNAs. Methods Real-time quantitative PCR was performed using a LightCycler rapid thermal cycler (Roche). Retinal VEGF mRNA levels were measured in a murine model of oxygen-induced retinopathy during vaso-obliterative and hypoxic phases. Results This technique was able to detect as few as 10 control template copies, with quantitative data available routinely for 1000 or more copies. The levels of retinal VEGF mRNA expression followed the hypoxia-induced pattern determined previously by conventional methods. All gene-specific primer pairs which amplify a specific product by conventional PCR were successfully converted to SYBR Green analysis, including those for housekeeping genes glyceraldehyde phosphate dehydrogenase (GAPDH), cyclophilin, and acidic ribosomal phosphoprotein PO (ARP/36B4) and for 28S rRNA. In each case melting curve analysis and agarose gel electrophoresis confirmed the specificity of the amplification product. Conclusions The sequence-independent detection of DNA with SYBR Green I means that it can be used to quantify the amplification of any cDNA using gene-specific primers. This rapid and flexible method is ideally suited for researchers in vision science wishing to quantify mRNAs from many different genes because it does not require investment in gene-specific hybridization probes.
TL;DR: In this article, the authors show that the invasive Ponto-Caspian crustacean amphipod Dikerogammarus villosus is rapidly eliminating Gammarus duebeni, a native European Amphipod, and Gammars tigrinus, until now a spectacularly successful invader from North America.
Abstract: As the tempo of biological invasions increases, explanations and predictions of their impacts become more crucial. Particularly with regard to biodiversity, we require elucidation of interspeci¢ c behavioural interactions among invaders and natives. In freshwaters in The Netherlands, we show that the invasive Ponto-Caspian crustacean amphipod Dikerogammarus villosus is rapidly eliminating Gammarus duebeni , a native European amphipod, and Gammarus tigrinus , until now a spectacularly successful invader from North America. In the laboratory, survival of single (unguarded) female G.duebeni was signi¢ cantly lower when male D.villosus were free to roam as compared with isolated within microcosms. In addition, survival of paired (guarded) female G. duebeni was signi¢ cantly lower when male D.villosus as compared with male G.duebeni were present. D.villosus killed and consumed both recently moulted and, unusually, intermoult victims. Survival of G.tigrinus was signi¢ cantly lower when D.villosus were free to roam as compared with isolated within microcosms and, again, both moulted and intermoult victims were preyed upon. Male D.villosus were signi¢ cantly more predatory than were females, while female G.tigrinus were signi¢ cantly more often preyed upon than were males. Predation by D.villosus on both species occurred over a range of water conductivities, an environmental feature previously shown to promote amphipod coexistence. This predatory invader is predicted to reduce further the amphipod diversity in a range of freshwater habitats in Europe and North America.
TL;DR: Results indicate that lesions of PMWS can be induced by inoculating pigs with PCV2 alone, thereby fulfilling Koch's postulates.
TL;DR: Clinical audit can be a valuable assistance to any programme which aims to improve the quality of health care and its delivery, yet without a coherent strategy aimed at nurturing effective audits, valuable opportunities will be lost.
Abstract: Objective—To review the literature on the benefits and disadvantages of clinical and medical audit, and to assess the main facilitators and barriers to conducting the audit process. Design—A comprehensive literature review was undertaken through a thorough review of Medline and CINAHL databases using the keywords of “audit”, “audit of audits”, and “evaluation of audits” and a handsearch of the indexes of relevant journals for key papers. Results—Findings from 93 publications were reviewed. These ranged from single case studies of individual audit projects through retrospective reviews of departmental audit programmes to studies of interface projects between primary and secondary care. The studies reviewed incorporated the experiences of a wide variety of clinicians, from medical consultants to professionals allied to medicine and from those involved in unidisciplinary and multidisciplinary ventures. Perceived benefits of audit included improved communication among colleagues and other professional groups, improved patient care, increased professional satisfaction, and better administration. Some disadvantages of audit were perceived as diminished clinical ownership, fear of litigation, hierarchical and territorial suspicions, and professional isolation.The main barriers to clinical audit can be classified under five main headings.These are lack of resources, lack of expertise or advice in project design and analysis,problems between groups and group members, lack of an overall plan for audit, and organisational impediments. Key facilitating factors to audit were also identified: they included modern medical records systems, eVective training, dedicated staV, protected time, structured programmes, and a shared dialogue between purchasers and providers. Conclusions—Clinical audit can be a valuable assistance to any programme which aims to improve the quality of health care and its delivery. Yet without a coherent strategy aimed at nurturing eVective audits, valuable opportunities will be lost. Paying careful attention to the professional attitudes highlighted in this review may help audit to deliver on some of its promise.
TL;DR: A phylogenetic analysis of bat relationships using DNA sequence data from four nuclear genes and three mitochondrial genes indicates that microbat families in the superfamily Rhinolophoidea are more closely related to megabats than they are to other microbats, which implies that echolocation systems either evolved independently in rhinlophoids and otherMicrobat monophyly is uncorroborated by molecular data.
Abstract: Bats (order Chiroptera) are one of the few orders of mammals that echolocate and the only group with the capacity for powered flight The order is subdivided into Microchiroptera and Megachiroptera, with an array of characteristics defining each group, including complex laryngeal echolocation systems in microbats and enhanced visual acuity in megabats The respective monophylies of the two suborders have been tacitly assumed, although microbat monophyly is uncorroborated by molecular data Here we present a phylogenetic analysis of bat relationships using DNA sequence data from four nuclear genes and three mitochondrial genes (total of 8,230 base pairs), indicating that microbat families in the superfamily Rhinolophoidea are more closely related to megabats than they are to other microbats This implies that echolocation systems either evolved independently in rhinolophoids and other microbats or were lost in the evolution of megabats Our data also reject flying lemur (order Dermoptera) as the bat sister group, indicating that presumed shared derived characters for flying lemurs and bats are convergent features that evolved in association with gliding and flight, respectively
TL;DR: In this article, butyl-3methylimidazolium hexafluorophosphate, a room temperature ionic liquid, has been used as solvent for the living radical polymerisation of methyl methacrylate; the rate of reaction is enhanced and narrow polydispersity polymers are obtained which are easily isolated from the catalyst.
TL;DR: An analysis of the statistical properties of methods based on the inverse discrete Fourier transform (IDFT), a modification of the algorithm of Smith (1975) is presented, the new method requiring exactly one-half the number of IDPT operations and roughly two-thirds the computer memory of the original method.
Abstract: A number of different algorithms are used for the generation of correlated Rayleigh random variates. This paper presents an analysis of the statistical properties of methods based on the inverse discrete Fourier transform (IDFT). A modification of the algorithm of Smith (1975) is presented, the new method requiring exactly one-half the number of IDPT operations and roughly two-thirds the computer memory of the original method. Evaluations of and comparisons between various variate generation methods using meaningful quantitative measures are believed to be lacking. New quantitative quality measures for random variate generation have been proposed that are, in particular, meaningful and useful for digital communication system simulation. This paper presents the application of these measures to the IDFT method and three other methods of correlated variate generation, comparing the algorithms in terms of the quality of the generated samples and the required computational effort.
TL;DR: It is demonstrated that maternal diabetes affects higher aspects of central nervous system functioning in the fetus, particularly in fetuses of diabetic mothers and of non-diabetic mothers.
TL;DR: Behavioural observations showed that environmental enrichment reduced time spent inactive and time spent involved in harmful social and aggressive behaviour while increasing the time spent in exploratory behaviour.
TL;DR: It is found that the quantum entanglement of the unknown state can be lost during the teleportation even when the channel is quantum correlated, and a fundamental parameter of correlation information is introduced which dissipates linearly during the teleport through the noisy channel.
Abstract: Transfer of entanglement and information is studied for quantum teleportation of an unknown entangled state through noisy quantum channels. We find that the quantum entanglement of the unknown state can be lost during the teleportation even when the channel is quantum correlated. We introduce a fundamental parameter of correlation information which dissipates linearly during the teleportation through the noisy channel. Analyzing the transfer of correlation information, we show that the purity of the initial state is important in determining the entanglement of the replica state.
TL;DR: Metal enrichment, particularly of Pb, Zn and Cu, is ascribed to the uncontrolled discharge of untreated sewage waste and urban surface runoff, which has increased markedly since the beginning of rapid urbanisation.
TL;DR: The aim of this study was to determine sperm nuclear DNA integrity and mitochondrial function, to quantify possible apoptosis and to investigate any relationship between these parameters.
Abstract: Sperm DNA integrity is essential for accurate transmission of genetic material to offspring. Fragmentation of genomic DNA is an initial hallmark of apoptosis (programmed cell death). The aim of this study was to determine sperm nuclear DNA integrity and mitochondrial function, to quantify possible apoptosis and to investigate any relationship between these parameters. Semen samples (n = 25) were prepared by discontinuous Percoll density centrifugation (95.0:47.5). DNA integrity was determined using a modified alkaline single cell gel electrophoresis (Comet) assay. DNA fragmentation, possibly indicative of apoptosis, was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL). Mitochondrial transmembrane potential was determined using the mitochondrial probe 5,5',6,6'-tetrachloro-1,1', 3,3'-tetraethylbenzimidazolyl carbocyanine iodide (JC-1). The DNA integrity of prepared spermatozoa was significantly greater than that of semen (P < 0.005). Further, the percentage of spermatozoa with fragmented DNA and the degree of fragmentation within these cells in prepared spermatozoa is significantly less than in semen (P < 0.005). There is a significant correlation between DNA damage quantified using the Comet assay and DNA fragmentation determined using TUNEL (R = 0.562, P < 0.01). The percentage of spermatozoa with dysfunctional, possibly apoptotic, mitochondria was significantly lower in prepared spermatozoa than in neat semen samples (P < 0.001). There was a negative correlation between the percentage of spermatozoa with dysfunctional mitochondria and the percentage of progressively motile spermatozoa (R = -0.67, P < 0.01).
TL;DR: Findings indicate that dogs purchased from rescue shelters do exhibit behaviour problems that may lead to their return, and the number of dogs admitted or returned to rescue shelters with behaviour problems may be reduced by raising public awareness regarding the value of behaviour therapy.
TL;DR: This article investigated the effects of gender on the job satisfaction of UK academics and found that female academics at higher ranks of higher education were more satisfied with their jobs than male academics of comparable ranks.
Abstract: In recent years there has been a substantial rise in the number of women entering the work force One consequence of this trend is that it has generated considerable interest in the relationship between gender and job satisfaction The objective of this study was to investigate the effects of gender on the job satisfaction of UK academics A questionnaire including several demographic questions such as gender, rank and age was administered to 1,102 university teachers A total of 554 responses was received, giving a response rate of 503 per cent The results indicated that gender does not affect the job satisfaction of university teachers directly However, the interaction effect of gender and rank was statistically significant (p < 005) Overall, female academics at higher ranks namely, senior lecturers, readers and professors, were more satisfied with their jobs than male academics of comparable ranks The implications of this finding and other results are explored
TL;DR: A constant‐depth film fermenter was used to culture a steady‐state multispecies biofilm consisting of one strain each of Listeria monocytogenes, Pseudomonas fragi and Staphylococcus xylosus, which was seen to reach a steady state after 6 d in the chemostat.
Abstract: A constant-depth film fermenter (CDFF) was used to culture a steady-state multispecies biofilm consisting of one strain each of Listeria monocytogenes, Pseudomonas fragi and Staphylococcus xylosus. These bacteria were initially grown together in a conventional chemostat to achieve a steady state before being inoculated into the CDFF over an 18-h period. A dilute tryptone soya broth (TSB) medium was supplied to the CDFF and the biofilm allowed to develop over a 28-d period. This mature biofilm was then subjected to increasing levels of sodium hypochlorite solution to measure any antimicrobial effect. The three organisms were seen to reach a steady state after 6 d in the chemostat before being transferred to the CDFF where the mature multispecies biofilm reached steady state at 17 d. Listeria monocytogenes in both planktonic and biofilm growth stabilized at 1. 8 and 1.5%, respectively, of the total plate counts, while Ps. fragi and Staph. xylosus were the predominant organisms in the biofilm at 59% and 39.5%, respectively, of the total microbial population. Steady-state biofilms in the CDFF were exposed to increasing strengths of sodium hypochlorite; 200, 500 and 1000 p.p.m. free chlorine, but a substantial two-log cycle drop in bacterial numbers was only achieved at 1000 p.p.m. free chlorine. In planktonic culture all three organisms were completely eliminated when exposed to 10 p.p.m. free chlorine for a 30-s period.