Showing papers by "Trinity College, Dublin published in 1984"

A conceptualization of driving behaviour as threat avoidance

Abstract: A behavioural analysis of the driving task is presented, arising out of a brief review of the motivational dimensions of Wilde's (1981) theory of risk homeostasis and the zero risk model of driver behaviour proposed by Naatanen ana Summala (1976). The analysis is developed into a threat-avoidance model of driver behaviour. This suggests that, when confronted with a discriminative stimulus for a potential aversive event, what a driver does depends in particular on the rewards and punishments for alternative responses. Implications of the model for the learner driver, road safety measures and earlier conceptualizations of driver motivation are discussed.

Coli surface antigens 1 and 3 of colonization factor antigen II-positive enterotoxigenic Escherichia coli: morphology, purification, and immune responses in humans.

Abstract: Enterotoxigenic Escherichia coli (ETEC) of serotype O6:H16, biotype A, bearing colonization factor antigen II (CFA/II) possesses two distinct coli surface antigens, CS1 and CS3, whereas CFA/II-positive ETEC of serotype O8:H9 manifests only CS3. CS1 has been shown to be fimbrial in nature, but heretofore the morphology of CS3 has not been described. Accordingly, by immune electron microscopy we investigated the morphological characteristics of CS3 on bacterial cells and after purification. CS3 was found to consist of thin (2-nm), flexible, wiry, "fibrillar" fimbriae, visible both on bacteria (O6:H16, biotype A, and O8:H9 strains) and in the pure state. In contrast, CS1 exists as wider (6-nm), rigid fimbriae on the surface of O6:H16, biotype A, strains. By the use of antisera to CS1 and CS3 in immune electron microscopy, immunodiffusion in gel, and immunoblotting techniques, CS1 and CS3 were found to be immunologically as well as morphologically distinct. Six of nine volunteers who developed diarrhea after challenge with an O139:H28 ETEC strain bearing CS1 and CS3 had significant serological rises to purified CS1 and CS3 antigens, suggesting that both antigens are elaborated in vivo, play a role in pathogenesis, and stimulate an immune response.

A Grenville Sm–Nd age for the Glenelg eclogite in north-west Scotland

Abstract: Eclogite, a garnet–pyroxene rock with basaltic chemistry, is a product of unusually high-pressure metamorphism. In Scotland, it occurs within the Caledonian orogenic belt close to the Moine thrust, where it forms partially amphibolitized, easterly-dipping layers, associated with metasediments in the eastern Glenelg Lewisian inlier1–4. In spite of its potential importance for an understanding of the geological history of north-west Scotland, its age has never been established more precisely than ‘probably Proterozoic’4. A K–Ar omphacite age of 1,515 Myr5 is rendered unreliable by the possible presence of excess argon. We report here the results of an attempt to date the eclogite metamorphism by the Sm–Nd method. Two samples of eclogite yielded mineral isochrons of just over 1,000 Myr. The results represent clear evidence of Grenville metamorphism in Scotland, and imply close proximity of its front to the Moine thrust near Glenelg. Also, as the local Moine cover has not apparently reached eclogite facies, it was presumably deposited on an eroded Grenville basement.

The effect of inbreeding on competitive male-mating ability in drosophila melanogaster

Abstract: The effect of full-sib inbreeding on competitive male-mating ability (CI♂) in Drosophila melanogaster was investigated in two experiments. In the first, five inbred lines (with reserves) were assessed up to 18 generations. Linear inbreeding depression, of 5.9% per 10% increase in homozygosity, was observed. In a second experiment, 21 inbred lines were tested after three generations of full-sib mating (without reserves), and the decline with inbreeding was more severe, the male competitive index (CI♂) decreasing by 10.7% per 10% increase in F . The difference between these results is attributed to natural selection acting on variation within the inbred lines in extent of homozygosity, which can arise because of the peculiarly strong influence of linkage in Drosophila. Furthermore, differentiation between the lines may have reflected this variation rather than the various effects of different alleles fixed.—These results imply that the genetic variation in male-mating ability is largely due to dominance (no epistasis was detected) and are consonant with the proposition that intermale sexual selection is a very important component of fitness in D. melanogaster . There was no evidence of a positive correlation between male body size and competitive mating ability.

Paternalism, Drugs, and the Nature of Sports

Abstract: (1984). Paternalism, Drugs, and the Nature of Sports. Journal of the Philosophy of Sport: Vol. 11, No. 1, pp. 14-22.

A continuous multivariate exponential distribution

Abstract: A continuous multivariate exponential distribution is introduced which can model a full range of correlation structures and attains the Frechet bounds in the bivariate case, is easy to simulate, arises as a model for reliability and failure due to shocks, and is analogous to the multivariate normal distribution. Two examples are given in which it models data satisfactorily

12 The Minicell System as a Method for Studying Expression from Plasmid DNA

Abstract: Publisher Summary The major difficulty encountered when analyzing plasmid or phage encoded mRNA and polypeptides in whole (normal) bacterial cells is that the majority of these products are masked by those encoded by the host cell's chromosome. This difficulty often remains even when the genes of interest have been amplified by cloning into multicopy vectors. In relatively few cases does a very high rate of expression or the availability of a specific assay (e.g. zymogram staining or specific antisera) allow the experimenter to distinguish between the plasmid and chromosome-encoded products. It is usually necessary to label specifically the plasmid-encoded products in the absence of significant expression from the host cell's chromosome. In recent years, a number of techniques have been developed to achieve this. These include the use of bacterial minicells, the maxicell system, cell-free (in vitro) synthesis, selective expression from ColEl-type plasm ids after prolonged chloramphenicol treatemetn. These techniques have been designed to maximize expression from plasmid DNA while minimizing the level of background expression from the host chromosome or, in the case of the in vitro system, from mis-transcription or mis-translation.

Cation Distribution, Mössbauer Spectra, and Magnetic Properties of Ferripyrophyllite

Abstract: was analyzed by M6ssbauer spectroscopy, magnetization and magnetic susceptibility measurements. The iron is entirely ferric, and the main feature of the M6ssbauer spectrum at room temperature is a single absorption line with isomer shift 6 = 0.36(1) mm/sec due to iron in M2 sites. The line is broadened by a slight quadrupole splitting A = 0.18(1) mm/sec, the smallest yet reported for a sheet silicate. Weaker features corresponding to quadrupole doublets with relative intensities of 7% and 8% having 6 = 0.43(1) mm/sec; A = 1.22(2) mm/sec and 6 = 0.14(1) m m/sec; A = 0.59(2) mm/sec are assigned to ferric iron in nonequivalent octa- hedral and tetrahedral sites, respectively, giving the following formula, based on published chemical analysis: Cao.o5(Fe 3+

Lichens, soil development and the age of Holocene Valley floor landforms: Howgill Fells, Cumbria

Abstract: Little is known of the post-glacial sequence of erosion and deposition in upland Britain. In the Carlingill valley, Howgill Fells, Cumbria, Late Pleistocene solifluction surfaces and a high fluvial...

Serologically distinct fimbriae on enterotoxigenic Escherichia coli of serotype O6:K15:H16 or H-

Abstract: Serologically distinct, surface-associated, mannose-resistant haemagglutinins have been reported on enterotoxigenic Escherichia coli of serotype O6:K15:H16 or H- of human origin. Using immune electron microscopy, these haemagglutinins, termed the CS1 and CS2 antigens, have been identified as serologically distinct fimbriae, the presence of which correlates with the rhamnose fermentation phenotype of strains. The CS1 and CS2 fimbriae are morphologically indistinguishable from common type fimbriae. In contrast, using the same technique, no labelling of fimbriae was obtained with specific antibodies to another protein surface antigen termed the CS3 antigen, which is common to most strains of this serotype and also found on certain enterotoxigenic E. coli of serotype O8:H9. The morphological nature of the CS3 antigen was not disclosed.

An examination of yield surface distortion and translation

Abstract: It is shown that the components of a sixth rank anisotropy tensor are physically significant in representing the distortion observed in both the initial and subsequent yield surface for a polycrystalline material. This feature of anisotropy does not appear in the ellipsoidal surface given by previous theories in which second and fourth rank anisotropy tensors are employed. The number of tensor components, for a series function embodying tensor terms in ascending rank, reduces to a manageable number by the imposition of symmetry and coincidence between the axes of stress and principal orthotropic directions. The identification is made between the yield limits, as found from biaxial stress experiments and tensor components in composite sum form. A one-to-one correspondence is found from a further simplification through the assumption of incompressibility. This is confirmed experimentally for an orthotropic rolled copper and copper alloy sheet.

Current trends in amorphous magnetism

Abstract: Recent research on some topics in amorphous magnetism is reviewed and questions are posed which should be answered by future work. The topics are i) appearance of magnetism in binary alloys of the 3d transition elements Fe, Co and Ni with sp elements, ii) conflicting ground states of amorphous iron (ferromagnetic, asperomagnetic, paramagnetic), inferred by extrapolating different Fe x M 100-x system to x = 100, iii) influence of hydrogen on the magnetic properties of metallic glasses, iv) random magnetic anisotropy and v) amorphous ionic compounds with purely antiferromagnetic interactions.

Environmental, Stress-State and Section-Size Synergisms During Creep

Abstract: The time-dependent deformation and fracture characteristics of Inconel alloy X-750 have been studied at 700 $^\circ$C under uniaxial and biaxial stressing. Several unusual sets of results were obtained, which led to the discovery of synergistic interactions between the material and the environment employed during heat treatment. For example, when solid tension and thin-wall tubular torsion specimens were given the normal commercial heat treatment, lifetimes in torsion were found to lie outside the region delineated by the plane-stress isochronous rupture loci generated when fracture is controlled respectively by the maximum principal stress and the von-Mises effective stress. This is contrary to predictions of creep fracture models and at variance with published experimental work. The isochronous rupture behaviour only became `normal' when torsion life-times were compared with those obtained from tension tests on tubular specimens for which lifetimes were less than 5 % of those for solid ones. This unusually large effect of section size on lifetime was shown to be due to a corresponding change in creep resistance, rather than to a reduced fracture ductility. Detailed metallography identified the responsible micromechanism as being a very fine cavity dispersion in the near-surface region, which caused progressively more weakening as the section size was reduced. This profuse and spatially inhomogeneous cavitation was demonstrated as not being an inherent characteristic of the material but the result of some interaction with the environment-speculated as being the formation of metastable carbon dioxide gas bubbles - during heat treatment of testpieces.

Lough Ennell: laboratory studies on sediment phosphorus release under varying mixing, aerobic and anaerobic conditions

Abstract: SUMMARY. 1. The exchange of phosphorus between the epilimnetic (shallow zone) sediment and water column in Lough Ennell was investigated in laboratory experiments using five intact cores. 2. Variations in water mixing, sediment suspension and aerobic–anaerobic oxygen status in the water column and its effects on sediment phosphorus release rates were determined. 3. Experimental results indicated that phosphorus release is possible under both aerobic and anaerobic conditions. Aerobic release (0.025 mg P l−1 over 5 days) was possible up to the point when mass resuspension of sediment occurred. Anaerobic release for the same period and mixing conditions was 0.183 mg Pl−1. 4. The release rate under aerobic conditions at 10°C equates to an internal areal loading of 0.134 g P m−2 yr−1, which is approximately 17% and 30% of the average total phosphorus and orthophosphate loadings respectively for the period 1974–79. 5. The results clearly implicate aerobic inorganic phosphorus release from the epilimnetic sediments as a significant source of this nutrient to the overlying water column and is likely a major factor in the continuing eutrophic status in the lake.

A short elementary proof of the Bishop-Stone-Weierstrass theorem

Abstract: Fix the following notation. Let X be a compact Hausdorff space, and denote by C(X) the vector space of continuous complex-valued functions on X, equipped with the uniform norm ∥·∥x. Let A be a unital subalgebra of C(X). A non-empty subset S of X is said to be A-antisymmetric if whenever h ∈ A and h is real-valued on S then h is constant on S.

Vancomycin ototoxicity in patients with normal renal function.

Abstract: Three patients with normal renal function developed ototoxicity during vancomycin therapy. This is an uncommon occurrence and the literature is reviewed. Assumptions on "safe' levels of vancomycin are questioned.

Contemporary accounts of the Killarney Woods 1580–1870

Abstract: Numerous references to the history of woodland at Killarney can be found in accessible literature. The present woodlands represent survival from charcoal burning for iron-works, from estate management practices during the eighteenth century and from clear-felling and replanting during the period of the Napoleonic Wars. With the possible exception of woods on the Muckross Peninsula, all woodland stands in the Killarney Valley have been disturbed by various forms of human use in recent centuries. In the nineteenth century prior to modern afforestation with non-native trees, the introduction of exotic plants and animals has had a major impact on the landscape. The present protection of much of the Valley's woods in the National Park provides hope that natural woodland conditions will be re-established extensively with time. The existence of records of woodland in the literature is of great value in understanding the present condition of the Valley and in resolving the management problems it poses for conservation.

Binding of [3H]Imipramine to Human Platelet Membranes with Compensation for Saturable Binding to Filters and Its Implication for Binding Studies with Brain Membranes

Abstract: Apparent specific binding of [3H]imipramine to human platelet membranes at high concentrations of imipramine showed deviation from that expected of a single binding site, a result consistent with a low-affinity binding site. The deviation was due to displaceable, saturable binding to the glass fibre filters used in the assays. Imipramine, chloripramine, desipramine, and fluoxetine inhibited binding to filters whereas 5-hydroxytryptamine and ethanol were ineffective. Experimental conditions were developed that eliminated filter binding, allowing assay of high- and low-affinity binding to membranes. Failure to correct for filter binding may lead to overestimation of binding parameters, Bmax and KD for high-affinity binding to membranes, and may also be misinterpreted as indicating a low-affinity binding component in both platelet and brain membranes. Low-affinity binding (KD less than 2 microM) of imipramine to human platelet membranes was demonstrated and its significance discussed.

Anion accumulation by lichens i. the characteristics and kinetics of arsenate uptake by umbilicaria muhlenbergii

Abstract: Summary Arsenate was accumulated by discs of the lichen Umbilicaria muhlenbergii (Ach.) Tuck, to levels of 16/wnol As per gram oven-dry weight during 1 h incubation in solutions containing 40μmol of arsenate at pH 4–6. Studies at lower external concentrations and at different pH values revealed that the more protonated species of arsenate were absorbed most readily. Light enhanced arsenate uptake only marginally, which supports the interpretation that the bulk of uptake was by the non-photosynthetic fungal symbiont. Dinitrophenol caused a 30% reduction in uptake, while heat-killing lichen samples resulted in negligible absorption, even from solutions of high arsenate concentration. The kinetics of arsenate uptake were studied using the Michaelis-Menten treatment, and yielded an apparent value for Km of 360 ± 60 μ and a Vmax of 0.37 ± 0.03 μmol g−1 min−1 for H2AsO−4. Further analysis by means of the Hofstee and Lineweaver-Burk plots suggested that two uptake systems may exist. The above results are discussed in relation to published data on free-living fungi and algae and it is concluded that arsenate uptake provides a convenient means for investigating anion accumulation in lichens.

Crinoid arms from Salthill Quarry, Clitheroe, Lancashire

Abstract: SUMMARY Inadunates dominate the Chadian crinoid fauna of Salthill Quarry, Clitheroe, Lancashire, despite the apparent prevalence of camerates. Well-preserved arms of a crinoid, which have swollen axillaries and an ornament of tubercles, are derived from a new taxon of inadunate crinoid. The arms are pinnulate and branching is heterotomous at the secundaxils (except in the A-ray, which does not divide at this level). Dissociated brachials and radials of this species are common.