Showing papers by "Trinity College, Dublin published in 1986"
TL;DR: In this paper, a Bayesian approach to estimation and hypothesis testing for a Poisson process with a change point was developed, and an example was given, where a change-point was considered.
Abstract: SUMMARY A Bayesian approach to estimation and hypothesis testing for a Poisson process with a change-point is developed, and an example given.
238 citations
TL;DR: It may be concluded that the mean loss in probing attachment levels, commonly seen for shallow sites post-therapy, may be primarily due to the changes in shallow, thin healthy areas.
Abstract: Periodontal sites of shallow initial probing depth often seem to lose probing attachment following various types of periodontal therapy, including nonsurgical therapy. The susceptibility to this treatment-associated probing attachment loss may conceivably be related to gingival architecture as well as to the inflammatory status of the tissues. This study was designed to study the relationship of buccolingual gingival thickness and bleeding on probing in shallow buccal sites (less than or equal to 3.5 mm probing depth) to loss of probing attachment following nonsurgical therapy. 3 months following treatment consisting of oral hygiene instruction and supra- and subgingival debridement, thin (less than or equal to 1.5 mm), initially non-bleeding sites displayed a mean loss of probing attachment of 0.3 mm. Thick (greater than or equal to 2.0 mm), non-bleeding sites displayed a less noticeable mean loss of probing attachment, whereas bleeding sites of both categories of gingival thickness showed a tendency towards gains in probing attachment levels. It may be concluded that the mean loss in probing attachment levels, commonly seen for shallow sites post-therapy, may be primarily due to the changes in shallow, thin healthy areas.
197 citations
TL;DR: The structure and distribution of lymphoglandular complexes of the colon suggest that they are sites of antigen processing, and variations in structure and in the number of complexes found in certain colonic diseases are documented.
Abstract: The structure and distribution of lymphoglandular complexes of the colon are described. The cellular composition of these complexes, as detailed by immunohistochemistry and electron microscopy, suggests that they are sites of antigen processing. Variations in structure and in the number of complexes that are found in certain colonic diseases are documented.
185 citations
TL;DR: An hla-erm mutant was less virulent than the otherwise isogenic 8325-4 hla+ strain in a mouse peritonitis model, confirming that alpha-haemolysin is an important virulence factor.
173 citations
TL;DR: In this article, the problem of computing the Bayes factor for a log-linear model Mo against the saturated model M1 with vague prior information was considered, and it was shown that using the standard Jeffreys prior density proportional to (I1i) 1/2, the problem no longer arises.
Abstract: Spiegelhalter and Smith (1982)hereafter SSproposed an approximate method for calculating the Bayes factor for a log-linear model Mo for a contingency table against the saturated model M1, with vague prior information. We adopt their notation and denote by SS(n) equation (n) of SS. Suppose x1, ..., Xk have a multinomial distribution with parameters 014 ..., 4k where Xi 0 0, X4i = 1. We write yT = (log x1, ..., log xk), 01 = (log 01, ..., log dk), and Y = diag{x1, ..., Xk}. Then if M1 is the saturated model, and Mo is the nested, log-linear, model defined by setting the contrasts CO1 = 0, where C is an s x k matrix with rank s and rows summing to zero, the approximate Bayes factor Bo1 for Mo against M1 is given by SS (32). This, however, is indeterminate if any of the cell frequencies in the table is zero. This is because of the use by SS of a prior density proportional to (H+i)'. If, however, we use, instead, the standard Jeffreys prior density proportional to (I1i) 1/2, the problem no longer arises. Then, by the arguments of SS and Lindley (1964), the resulting Bayes factor is still given by SS (32), with xi replaced by xi + 2 in the definitions of y and Y (i = 1, . . ., k), and SS (33) replaced by c 1 = (2 )s2 1 CCT I 1/2. If this solution is adopted, the prior is proper, and so, in principle, the problem of assigning an arbitrary multiplicative constant, for which the SS approach was primarily devised, need not arise. One could, in theory, simply apply Bayes; theorem directly and so obtain the Bayes factor exactly. However, in practice, this is difficult to do, and I know of no general solution to the problem. Even for simpler, more specific, contingency table and related models, such as those of independence or equiprobability, finding the Bayes factor exactly is not too easy; see, for example, Crook and Good (1982), Altham (1971), Gunel and Dickey (1974), Gunel (1982), Broniatowski (1981), and references therein. The second purpose of this note is to point out that, conditionally on MO,
171 citations
TL;DR: Bimodal associations of basalt and rhyolite of Upper Ordovician age which were erupted in a submarine environment occur within the Caledonian orogenic belt of South Britain at Parys Mountain (Anglesey), in Snowdonia (North Wales) and at Avoca (SE Ireland).
Abstract: Bimodal associations of basalt and rhyolite of Upper Ordovician age which were erupted in a submarine environment occur within the Caledonian orogenic belt of South Britain at Parys Mountain (Anglesey), in Snowdonia (North Wales) and at Avoca (SE Ireland). The volcanic rocks have experienced hydrothermal alteration and low-grade metamorphism, and therefore immobile elements (e.g. Ti, Zr, Nb, Y) have been used to identify the original geochemical characteristics. The basalts have characters transitional between volcanic ‘arc’ and ‘within plate’ types consistent with eruption on an extensional part of an active continental margin. Two groups of rhyolites have been identified. A low-Zr group (Zr 500ppm), represented at Snowdonia and Avoca, is interpreted as originally being peralkaline in composition; their high Zr/Nb ratios (>10) are typical of peralkaline rhyolites erupted above subduction zones. The bimodal nature of the associations and the peralkaline character of some rhyolites indicates magma production in a complex tectonic setting, transitional between an active continental margin/island arc and an extensional environment. Associated sulphide mineralization is volcanogenic and probably syn-sedimentary. High-level, rhyolitic magma chambers are thought to have driven convection of the hydrothermal fluids from which the sulphides precipitated.
167 citations
TL;DR: This is the first report of an immunoglobulin G (IgG) autoantibody reactive with C1¯-Inh, a pivotal inhibitor of the inflammatory response which is known to inactivate proteins of the complement, kinin, fibrinolytic arid ‘contact phase’ systems.
Abstract: Antibodies are considered to play a specific pathogenic role in certain disease states such as myasthenia gravis, Graves' disease and autoimmune haemolytic anaemia. Autoantibodies which interfere with the function of enzyme cascade systems have also been described in diseases such as acquired haemophilia (anti-factor VIII antibodies) and glomerulonephritis (C3 nephritic factor). The identification of these autoantibodies is crucial to an understanding of the aetiology of such diseases and is also of importance in revealing the inter-relationships of the immune system with other biological pathways. This is the first report of an immunoglobulin G (IgG) autoantibody reactive with C1-inhibitor (C1-Inh), a pivotal inhibitor of the inflammatory response which is known to inactivate proteins of the complement, kinin, fibrinolytic and 'contact phase' systems. This autoantibody was isolated from a patient with a novel variant of acquired angioedema and C1-Inh dysfunction. This finding highlights the involvement of the immune system in the pathogenesis of disorders characterized by the presence of dysfunctional inflammatory response proteins.
158 citations
TL;DR: In this article, the distribution of cell areas for a Voronoi network is examined by computer simulation, and a rough argument is presented as to how this form of distribution may be derived analytically.
Abstract: The distribution of cell areas for a Voronoi network is examined by computer simulation, and a rough argument is presented as to how this form of distribution may be derived analytically. The resulting form is a gamma function as was previously used by Kiang (1966) to fit numerical data of cell areas. Computer-generated distributions for large samples of cells are here used to test this suggested function more stringently than in Kiang's work.
116 citations
TL;DR: In this article, eight new K-Ar determinations are presented which, together with field relations and previous studies, are used to construct a chronology of the volcanic build-up of Fuerteventura.
Abstract: Eight new K-Ar determinations are presented which, together with field relations and previous studies, are used to construct a chronology of the volcanic build-up of Fuerteventura. The earliest island-building volcanics are late Cretaceous to early Tertiary alkaline basaltic volcaniclastic sediments, and these may be correlated with the early gabbro/pyroxenite intrusions which were probably subvolcanic to the early edifice. This was followed by a carbonatitic subvolcanic complex then by two later high-level gabbro/pyroxenite plutons, the latter being early Miocene or older. The emplacement of a subsequent middle Miocene gabbro/syenite ring complex caused widespread resetting of the Ar contents of the earlier rocks, but nevertheless consideration of the mineralogy of the rocks in conjunction with the field relations enables the long volcanic history ( c . 80 Ma) to be reconstructed.
115 citations
88 citations
TL;DR: The evidence for a role for thiomolybdates in the important ruminant disease syndromes of molybdenosis and Mo-induced hypocuprosis is outlined and present knowledge of their chemistry and metabolism in vivo is reviewed in an attempt to provide a less empirical basis for their toxicology.
TL;DR: The observed frequencies of all restriction sites in the genomes of all completely sequenced DNA phages have been compared to expected frequencies derived from trinucleotide frequencies and it is concluded that the effect indeed results from natural selection.
Abstract: Restriction enzymes produced by bacteria serve as a defense against invading bacteriophages, and so phages without other protection would be expected to undergo selection to eliminate recognition sites for these enzymes from their genomes. The observed frequencies of all restriction sites in the genomes of all completely sequenced DNA phages (T7, lambda, phi X174, G4, M13, f1, fd, and IKe) have been compared to expected frequencies derived from trinucleotide frequencies. Attention was focused on 6-base palindromes since they comprise the typical recognition sites for type II restriction enzymes. All of these coliphages, with the exception of lambda and G4, exhibit significant avoidance of the particular sequences that are enterobacterial restriction sites. As expected, the sequenced fraction of the genome of phi 29, a Bacillus subtilis phage, lacks Bacillus restriction sites. By contrast, the RNA phage MS2, several viruses that infect eukaryotes (EBV, adenovirus, papilloma, and SV40), and three mitochondrial genomes (human, mouse, and cow) were found not to lack restriction sites. Because the particular palindromes avoided correspond closely with the recognition sites for host enzymes and because other viruses and small genomes do not show this avoidance, it is concluded that the effect indeed results from natural selection.
TL;DR: In this article, it was shown that the primary passivating process in the case of iron dissolution in aqueous media is the formation of a compact, anhydrous Fe(II) oxide or hydroxide - possibly a mixture of the two.
TL;DR: In this article, the results of a Monte Carlo simulation for the temporal evolution of a two-dimensional soap froth are reported, which is an alternative method to the previous technique used to model the froth by Weaire and Kermode (1983 b).
Abstract: The results of a Monte Carlo simulation for the temporal evolution of a two-dimensional soap froth are reported. The simulation was used, in particular, to study the asymptotic behaviour of the system, as t→∞. It is an alternative method to the previous technique used to model the froth by Weaire and Kermode (1983 b). In the Monte Carlo simulation the network of cells is mapped onto a discrete lattice of (200 × 200) points with periodic boundary conditions. The main quantities of interest are the rate of increase of average cell diameter and the behaviour of the distribution of numbers of sides f(n), characterized by its second moment, as a function of time.
TL;DR: In this paper, a technique for measuring the complex, frequency-dependent susceptibility of small volumes of ferrofluids is presented, and results of measurements performed on two colloidal dispersions of cobalt ferrite are given.
Abstract: A technique for measuring the complex, frequency-dependent susceptibility of small volumes of ferrofluids is presented. Results of measurements performed on two colloidal dispersions of cobalt ferrite are given which confirm the earlier work of Maiorov (1979).
TL;DR: The Hlb determinant from Staphylococcus aureus CN6708 was cloned in Escherichia coli K-12 using the bacteriophage replacement vector λL47.1 as discussed by the authors.
TL;DR: This paper investigated the cognitive load associated with the processing of new arguments in expository texts and found that when the representation is constructed to maximize effective retrieval, subjects allocate a greater amount of cognitive resources to processing new arguments at the sentence boundary than at non-boundary locations.
01 Jan 1986
TL;DR: In this article, the authors classify oxides into two groups: (1) compact, anhydrous oxides such as rutile, perovskite, spinel, and ilmenite, in which oxygen is present only as a bridging species between two metal cations and ideal crystals constitute tightly packed giant molecules; and (2) dispersed, hydrous Oxides where oxygen is presented not just as a bridge species between metal ions, but also as O-, OH, and OH2 species, i.e., in coordinated terminal group form.
Abstract: For the purpose of this review it is convenient to classify oxides into two groups: (1) compact, anhydrous oxides such as rutile, perovskite, spinel, and ilmenite in which oxygen is present only as a bridging species between two metal cations and ideal crystals constitute tightly packed giant molecules; and (2) dispersed, hydrous oxides where oxygen is present not just as a bridging species between metal ions, but also as O-, OH, and OH2 species, i.e., in coordinated terminal group form. In many cases the latter materials when in contact with aqueous media contain considerable quantities of loosely bound and trapped water, plus, occasionally, electrolyte species. Indeed, with highly dispersed material (dispersion here refers to the molecular level, i.e., microdispersion, not to the finely divided state where the oxide microparticles may still be compact in character, i.e., macrodispersion), the boundary between the solid and aqueous phases may be somewhat nebulous as the two phases virtually intermingle. While compact oxides are usually prepared by thermal techniques, e.g., direct combination of the elements, decomposition of an unstable salt, or dehydration of a hydrous oxide, the dispersed oxides are almost invariably prepared in an aqueous environment using, for instance, base precipitation or electrochemical techniques.
TL;DR: The evident consumer satisfaction for TENS suggests TENS has a part to play in analgesia in labour but the equivocal findings in terms of factors associated with pain relief points to the need for apparatus more specifically designed to cope with the special characteristics of the pain of labour.
TL;DR: The magnetic phase is fully-oxidized titanomaghemite which is inherited directly from weathered bedrock as discussed by the authors and is a good indicator of soil type, being greatest in those soils derived from mafic or itabiritic rocks which have been little influenced by xanthization (the soil yellowing process).
TL;DR: The neurophysiological effects of buspirone and isapirone were compared with those of 5-hydroxytryptamine on the population spike in the CA1 region of the rat hippocampal slice and it is suggested that these drugs are agonists for 5-HT1A receptors in the hippocampus.
TL;DR: In this paper, an instrument for the quantitative study of gas-solid reactions is described, focusing on pressure changes within a small volume, rather than mass variations as in thermogravimetry.
Abstract: An instrument for the quantitative study of gas-solid reactions is described. By focusing on pressure changes within a small volume, rather than mass variations as in thermogravimetry, greater sensitivity can be achieved.
TL;DR: In this paper, the authors present data on occupational mobility in the Republic of Ireland in greater detail than has been available previously, and find that the relative low mobility rate in Ireland is due to the combined effects of an occupational composition that favours immobility and a pattern of strong association between class origins and destinations.
Abstract: We present data on occupational mobility in the Republic of Ireland in greater detail than has been available previously. The primary datum is a 14x 14 mobility table. The categories are subclassifications of the nine categories used in analyses of other European societies by Erikson, Goldthorpe, and others. The refined categories show details of mobility in Ireland that are important for understanding the complete structure of association between class origins and destinations. Gross rates of mobility in Ireland are lower than the rates observed in countries for which comparable data are available. Furthermore, the mobility that occurs is very often mobility between categories that differ little in market position or socioeconomic status. We find that the relative low mobility rate in Ireland is due to the combined effects of an occupational composition that favours immobility and a pattern of strong association between class origins and destinations. 'Countermobility,' i.e., instances of downward mobility to first jobs (often in unpaid work on a farm or in a shop) followed by upward career mobility that returns the worker to his class of origin is also an important component of Irish occupational mobility. The association between origins and destinations has a very strong vertical component which we measure using prestige and educational credentials. Market position affects immobility as informal labour markets increase immobility while bureaucratic
TL;DR: The gene coding for serotype A of epidermolytic (exfoliative) toxin has been cloned from Staphylococcus aureus in Escherichia coli phage lambda and plasmid vectors and was shown to be dependent on the integrity of the agr gene which is known to be required for the expression of several exoproteins.
TL;DR: Adenocarcinomas containing endocrine cells appear to be as biologically aggressive as the usual adenocARCinomas of the stomach and therefore should be treated in a like manner.
Abstract: Twenty-six of 100 cases of gastric adenocarcinoma contained argyrophil cells. All these tumours were carcino-embryonic antigen positive and 13 contained variable amounts of gastro-enteropancreatic peptides and amines. There was no significant difference in mucin type, extent or incidence of intestinal metaplasia between tumours with and those without endocrine cells. The prognosis for both groups was similarly poor, contrasting with that for carcinoid and atypical carcinoid. Endocrine cell hyperplasia was evident in the adjacent mucosa in some of the cases of endocrine positive tumours. There was no association between achlorhydria and the presence of endocrine cells in the tumours. The origin of the neoplastic endocrine cells remains speculative, occurring either as a mutation of a single stem cell or as a synchronous malignant transformation of two epithelial cell types exposed to a particular carcinogenic factor(s). Adenocarcinomas containing endocrine cells appear to be as biologically aggressive as the usual adenocarcinomas of the stomach and therefore should be treated in a like manner.
TL;DR: There is evidence in support of a neurally derived tumor being the direct source of neurosecretion of arginine vasopressin rather than neurohypophyseal secretion or secretion from non-neural tissues, as reported to date in the etiology of the syndrome of inappropriate antidiuresis.
TL;DR: In this paper, the authors measured the 18O/16O and D/H ratios of the basal complexes of Fuerteventura, Gomera and La Palma.
Abstract: 18O/16O and D/H ratios have been measured in rocks and mineral separates from the basal complexes of Fuerteventura, Gomera and La Palma. These complexes comprise alkali plutonic rocks ranging from olivine gabbros to syenites and dikes of various mineralogy cutting them, all metamorphosed under greenschist conditions. K-Ar determinations gave ages from 48 to 17 My. The δ18O's and δD's of these rocks range from −1,4 to +11 and −113 to −45 respectively, with a majority of rocks depleted in heavy isotopes relative to normal, deep seated values. These values do not correspond to those found in ophiolitic sequences, which, for a comparable temperature range, give minimum δ18O's>3. These values are explained in terms of water-rock interactions involving limited amounts of meteoric waters from high elevations. This implies the existence of a very important volcanic edifice over Fuerteventura in the Miocene Oligocene period with elevations between 2,500 and a maximum of more than 4,000 m.
TL;DR: The loss of CFA/I and C FA/II production was associated with the loss of DNA sequences encoding for ST-A2 in 20 of 21 ETEC examined and with no discernible loss of a plasmid or DNA sequences coding for enterotoxins in the remaining strain.
Abstract: Colonization factor antigens I and II (CFA/I and CFA/II) are important in the pathogenesis of diarrhea in humans caused by some enterotoxigenic Escherichia coli (ETEC). Plasmid DNA from 16 CFA/I+ and five CFA/II+ ETEC were examined by Southern blot analysis with enterotoxin gene probes and were compared with plasmid DNA from derivatives of the same ETEC that had lost the ability to produce these colonization factors. Among the 16 CFA/I+ ETEC strains, the loss of CFA/I was accompanied by the loss of a plasmid of between 34 and 68 megadaltons (MDa) coding for heat-stable enterotoxin A2 (ST-A2) in 12 strains, by the loss of a 60-MDa plasmid coding for heat-labile enterotoxin (LT) and ST-A2 in one strain, or by deletions of a segment of DNA encoding for ST-A2 in three strains. Among five CFA/II+ ETEC strains, the loss of CFA/II was associated with the loss of a plasmid of 75 MDa coding for LT and ST-A2 in three strains, with the loss of genes coding for LT and ST-A2 from a 68-MDa plasmid in one strain, or with no discernible loss of a plasmid or DNA sequences coding for enterotoxins in the remaining strain. The loss of CFA/I and CFA/II production was associated with the loss of DNA sequences encoding for ST-A2 in 20 of 21 ETEC examined.
TL;DR: In this paper, the results on magnetization, Curie temperature, magnetocrystalline anisotropy, magnetic structure, spin-reorientation transitions and magnetostriction are reviewed for the R2M14B series of compounds, with M ≡ Fe or Co. The results are analysed in terms of exchange and crystal-field interactions, and some unsolved problems are identified.
Abstract: Results on magnetization, Curie temperature, magnetocrystalline anisotropy, magnetic structure, spin-reorientation transitions and magnetostriction are reviewed for the R2M14B series of compounds, with M ≡ Fe or Co. Some Fe-Co solid solutions and hydrides are also discussed. The results are analysed in terms of exchange and crystal-field interactions, and some unsolved problems are identified.
TL;DR: Tryptamine was found to be a substrate for both forms of the enzyme in human liver, kidney cortex and medulla and in seven different brain regions, suggesting that both form of monoamine oxidase would contribute to the metabolism of tryptamine in human tissues.