Showing papers by "University College Dublin published in 1991"

Compressive behaviour of concrete at high strain rates

Abstract: Experimental techniques commonly used for high strain-rate testing of concrete in compression, together with the methods used for measurement and recording of stress and strain, are critically assessed in the first part of this paper. The physical capability of each loading method is discussed and some consideration is given to the definitions used for specifying the loading rate. The second part reviews the dynamic compressive strength (mostly uniaxial rather than bi- or triaxial) of plain concrete, while in the third part a review on deformation behaviour indicates that uncertainty and disagreement exist concerning changes in axial strain at high strain rates.

The Role of Sponsorship in the Marketing Communications Mix

Abstract: This article examines the development of commercial sponsorship as a legitimate marketing communications option available to management. Initial attention focuses on the causes of sponsorship emergence, the current developments in this growing industry and the prospects therein. Sponsorship's role on behalf of management is then discussed in terms of potential objectives and target audiences. Sponsorship management issues in terms of selection, implementation and results evaluation are subsequently examined.

The Acquisition of Community Speech Norms by Asian Immigrants Learning English as a Second Language: a preliminary study

Abstract: We investigate Vietnamese and Cambodian immigrants' acquisition of the variable (ing), which occurs in progressive tenses, participles, noun phrases, etc., and which can be pronounced [iŋ] or [In]. A VARBRUL 2 program analysis of native speaker speech shows that the production of (ing) is constrained by phonological, grammatical, stylistic, and social factors. An analysis of the nonnative speakers' acquisition of these norms shows that [In] is more frequent before anterior segments (reflecting ease of articulation), and that males use [In] more frequently than females, especially in monitored speech (perhaps reflecting their desire to accommodate to a male native speaker norm rather than to an overall native speaker norm). The analysis also shows evidence of grammatical constraints which are different from those in the native speakers' speech. This difference may reflect the fact that it is easier to acquire the [In] variant in “frozen forms,” such as prepositions, than in productive rules.

Effect of dietary intake on pattern of growth of dominant follicles during the oestrous cycle in beef heifers.

Abstract: Friesian x Hereford heifers (n = 19; mean +/- s.e.m. body weight (BW) = 375 +/- 5 kg) were used in a randomized incomplete block design. Heifers were fed 0.7 (n = 7; L), 1.1 (n = 7; M) or 1.8% (n = 5; G) of BW in dry matter (DM)/day for 10 weeks. Ovaries were examined by ultrasound, for one oestrous cycle, from week 5 of treatment. Maximum diameter of dominant follicles was smaller (P less than 0.05) in L (11.8 +/- 0.1 mm) than in M (13.7 +/- 0.2 mm) or G (13.2 +/- 0.3 mm) heifers. Growth rate (mm/day) of dominant follicles during the oestrous cycle was not affected (P greater than 0.05) by dietary intake. Persistence of dominant follicles was shorter (P less than 0.05) in L (9.8 +/- 0.2 days) than in M (11.9 +/- 0.3 days) or G (12.7 +/- 0.4 days) heifers. Three dominant follicles were identified during the oestrous cycle of 5 of 7 L, 3 of 7 M and 1 of 5 G heifers (P less than 0.10); 2 dominant follicles were identified in the remaining heifers (n = 2 of 7, 4 of 7 and 4 of 5, respectively). Length of the luteal phase and luteal-phase concentrations of progesterone were not affected (P greater than 0.05) by treatment. Low dietary intake reduced the diameter and persistence of dominant follicles during the oestrous cycle of beef heifers and tended to increase the proportion of oestrous cycles with 3 dominant follicles.

The development of Irish offshore sedimentary basins

Abstract: A variety of ensialic Mesozoic and Cenozoic sedimentary basins surround Ireland. Three main periods of basin development occurred. The first, in the Permo-Triassic, produced a series of small rift basins which nucleated along reactivated, generally Caledonian, structures. The second, in the Mid- and Late Jurassic, represents a period of crustal extension and rifting. The third phase reflects thermal subsidence of Cretaceous and Tertiary age, and coincides with seafloor spreading in the North Atlantic. The basins developed in response to general east-west extension. Simple extensional structures, accompanied by crustal thinning, dominated in the north-south-trending Porcupine Basin. The NE-SW-oriented basins in the Celtic Sea, Slyne-Erris-Donegal and Rockall areas developed in a transtensional setting until Early Cretaceous times. The Goban Spur basins, at the confluence of regional structural trends, and adjacent to the continent-ocean boundary, are dominated by transtensional structures. The effects of Early Tertiary Alpine compression are seen especially in the Celtic Sea basins. The basins, whilst having some broad geological similarities which reflect eustatic sea-level variations, differ in their detailed evolution. Each basin experienced unique facets of local structural control, tectonic history and facies distribution.

Juvenile Middle Proterozoic crust in the Adirondack Highlands, Grenville province, northeastern North America

Abstract: Nd isotope data indicate that minimal amounts of significantly older crust have contributed to the genesis of the oldest (ca. 1.3-13.5 Ga) plutons in the Adirondack Highlands. These are magmatic arc tonalites with positive initial {epsilon}{sub Nd} values and Sm-Nd depleted mantle model ages (t{sub DM}) that are within 70 m.y. of the time of their crystallization. Granitoids of the anorthosite-mangerite-charnockite-granite suite, dated at 1,156-1,134 Ma, as well as the 1,100-1,050 Ma plutons, associated with the Ottawan phase of the Grenvillian orogenic cycle, also have positive initial {epsilon}{sub Nd} values and t{sub DM} ages similar to the tonalites. Derivation of both groups of granitoids by crustal melting of the magmatic arc is consistent with the available isotopic and geochemical data. Juvenile late Middle Proterozoic crust that formed during or just prior to the Grenville cycle appears to dominate the southwestern Grenville province as well as the Grenville inliers to the south. In contrast, most of the contiguous Grenville province in Canada comprises largely reworked older crust.

The fatigue performance of machined surfaces

Abstract: It is well known that surface condition has a strong effect on fatigue life, and that most surfaces produced by conventional manufacturing operations such as machining and forging have poorer fatigue behaviour than polished surfaces commonly used for laboratory specimens. As yet, there are no reliable quantitative models to predict the behaviour of such surfaces; the problem is a multi-parameter one, involving surface roughness, surface microstructure and residual stress. High-cycle fatigue data was obtained for En19 steel, using four types of machined surface, produced by: polishing, grinding, milling and shaping. Residual stress was eliminated by heat treatment. Fatigue limit data were plotted as a function of roughness parameters using Kitagawa-type diagrams, and compared to simple notch-based and crack-based models. It was found that, whilst both theories tended to be overly conservative, fracture mechanics approaches are useful for relatively low roughness, when the surfaces can be modelled as a series of short cracks. For higher roughness a notch-based approach is appropriate.

X-UV Absorption Spectroscopy with Laser-Produced Plasmas: A Review

Abstract: Exteme-ultraviolet (X-UV) absorption spectroscopy has gained impetus in recent years, spurred on by a growing interest in the physics of core excited atomic, molecular and solid species. Progress in this field has been helped in no small measure by developments in X-UV light sources. One such source is the laser-produced plasma which, by suitable choice of target material, can be used to produce a clean, line free continuum virtually throughout the X-UV and V-UV spectral regions from 40-2000 ?. We briefly address here the issues surrounding the origin and characteristics of laser-plasma continuum light sources. In addition we review progress to date on the application of these sources to the study of the X-UV photoabsorption spectra of atoms, ions and molecules.

Geochronological evidence from discordant plutons for a late Proterozoic orogen in the Caledonides of Finnmark, northern Norway

Abstract: Rb-Sr whole-rock, Sm-Nd mineral and U-Pb zircon dates are reported for minor 0granites and Seiland Igneous Province gabbros in the Kalak Nappe complex (Middle Allochthon), northern Norwegian Caledonides. The Litlefjord (Rb-Sr WR 813 ± 62 Ma, MSWD 2.7; U-Pb zircon 804 ± 19 Ma, MSWD 5.5) and Repvig (Rb-Sr WR 851± 130 Ma, MSWD 5.1) granites and the Hasvik gabbro (Sm-Nd WR/minerals 700 ± 33 Ma, MSWD 0.7) cut previously-deformed metasediments of the Scbrcby Succession while the Kvalfjord (Sm-Nd WR/minerals 612 f ± 33 Ma, MSWD 0.1) and Storvik (Sm-Nd WR/minerals 604 ± 44 Ma, MSWD 0.2) gabbros cut ‘basement9 paragneisses. The main (Dl–D2) deformation affecting the Sbrcby Succession in the Kalak Nappe complex, which was previously attributed to the early Ordovician Finnmarkian phase of the Caledonian orogeny, took place before c. 800 Ma in the pre-Caledonian 9Porsanger Orogeny9. Early ‘Soroy’ plutons of the Seiland Igneous Province were apparently emplaced during this event. However, the later, more voluminous ‘Stjernoy’ intrusions are c . 700–520 Ma old and post-date the Porsanger orogeny. These pre-Caledonian intrusions must be inter-, rather than syn-orogenic as previously claimed. This obviates the problem of accomodating the voluminous Seiland magmatism during orogenic compression and is consistent with an early Caledonian rift origin for these rocks, probably related to the opening of Iapetus.

Ocular manifestations in fetal alcohol syndrome.

Abstract: Eight children with the fetal alcohol syndrome are described with ocular anomalies They all had a strong history of maternal alcohol abuse throughout pregnancy, especially in the first trimester All the children had eye abnormalities These included external eye lesions, Peters' anomaly, lens opacification, ocular motility disorders, and optic nerve hypoplasia

Products of Matrices

Abstract: We consider the problem of expressing an element A in GL(n, F), where F is a given field, as a product of elements in certain given distinguished subsets of GL(n,F). In particular, we consider the following types of decomposition: (i) A as a multiplicative commutator X -1 Y -1 XY (assuming detA = ±1). (ii) A as a product of involutions (assuming detA = ±1). (iii) A as a product of two involutions (assuming A is similar to A -1). (iv) A as a product of a symmetric matrix by an involution. (v) A as a product of skew-symmetric matrices.

Social indicators of living conditions in Ireland with European comparisons

Abstract: This monograph presents data from a nationwide survey of social indicators of living conditions in Ireland. This survey was part of a European Community (EC)-harmonised survey of subjective social indicators carried out in eight EC countries. The survey, the first of two, focussed on people's perceptions of their health, health services, housing, neighbourhood and life in general. Extensive analysis is made of the demographic determinants of a wide range of subjective measures of well-being in all of these life domains. Examination is also made of the predictors of global measures of well-being. Data are presented for Ireland and multi-nation comparative data are also presented throughout. Emphasis is placed on the relationship between objective and subjective social indicators.

Redox and flavin‐binding properties of recombinant flavodoxin from Desulfovibrio vulgaris (Hildenborough)

Abstract: Flavodoxin from Desulfovibrio vulgaris (Hildenborough) has been expressed at a high level (3-4% soluble protein) in Escherichia coli by subcloning a minimal insert carrying the gene behind the tac promoter of plasmid pDK6. The recombinant protein was readily isolated and its properties were shown to be identical to those of the wild-type protein obtained directly from D. vulgaris, with the exception that the recombinant protein lacks the N-terminal methionine residue. Detailed measurements of the redox potentials of this flavodoxin are reported for the first time. The redox potential, E2, for the couple oxidized flavodoxin/flavodoxin semiquinone at pH 7.0 is -143 mV (25 degrees C), while the value for the flavodoxin semiquinone/flavodoxin hydroquinone couple (E1) at the same pH is -440 mV. The effects of pH on the observed potentials were examined; E2 varies linearly with pH (slope = -59 mV), while E1 is independent of pH at high pH values, but below pH 7.5 the potential becomes less negative with decreasing pH, indicating a redox-linked protonation of the flavodoxin hydroquinone. D. vulgaris apoflavodoxin binds FMN very tightly, with a value of 0.24 nM for the dissociation constant (Kd) at pH 7.0 and 25 degrees C, similar to that observed with other flavodoxins. In addition, the apoflavodoxin readily binds riboflavin (Kd = 0.72 microM; 50 mM sodium phosphate, pH 7.0, 5 mM EDTA at 25 degrees C) and the complex is spectroscopically very similar to that formed with FMN. The redox potentials for the riboflavin complex were determined at pH 6.5 (E1 = -262 mV, E2 = -193 mV; 25 degrees C) and are discussed in the light of earlier proposals that charge/charge interactions between different parts of the flavin hydroquinone play a crucial role in determining E1 in flavodoxin.

Obstructive Sleep Apnea following Topical Oropharyngeal Anesthesia in Loud Snorers

Abstract: Previous studies support the presence of an upper airway reflex mechanism that contributes to the maintenance of upper airway patency during sleep. We investigated the possibility that interference with this reflex mechanism contributes to the development of obstructive sleep apnea. Eight otherwise asymptomatic snorers (seven male and one female), age 39 ± 5.3 yr (mean ± SEM), underwent overnight sleep studies on three successive nights. An acclimatization night was followed by two study nights randomly assigned to control (C) and oropharyngeal anesthesia (OPA). On the OPA night topical anesthesia was induced using 10% lidocaine spray and 0.25% bupivocaine gargle. A saline placebo was used on night C. All subjects slept well on both study nights (mean sleep duration was 6.2 h on both study nights), and sleep stage distribution was similar on both nights. Obstructive apneas and hypopneas (OAH) rose from 114 ± 43 during C to 170 ± 49 during OPA (p < 0.02). Central apneas and hypopneas (CAH) were unchanged b...

What photoperiodic signal is provided by a continuous-release melatonin implant?

Abstract: The purpose of this study was to evaluate whether the insertion of a continuous-release melatonin implant into ewes provides a short-day photoperiodic signal or acts as a functional pinealectomy (provides no specific photoperiodic signal but renders ewes incapable of responding to changes in photoperiod). Ewes primed with 60 long days (18L:6D) during the spring were moved to intermediate day length (13L:11D) for 66 days and then given one of five treatments: 1) short-day control, second drop in photoperiod to 8L:16D; 2) intermediate-photoperiod control, kept on 13L:11D; 3) pinealectomy and kept on 13L:11D; 4) melatonin implant and kept on 13L:11D; 5) melatonin implant and moved to 8L:16D. Mean number of estrous cycles per group and total duration of reproductive activity were determined. Ewes in all groups began to exhibit estrous cycles after the initial reduction in photoperiod. The number of estrous cycles and duration of reproductive activity differed among groups. The number of estrous cycles and duration of reproductive activity was extended in ewes receiving the second drop in photoperiod compared to that of the intermediate-photoperiod controls. Pinealectomized ewes had a number of estrous cycles and duration of reproductive activity similar to those of ewes maintained on the intermediate photoperiod. Melatonin implants increased the number of estrous cycles and prolonged reproductive activity in ewes maintained on the intermediate photoperiod; melatonin implants did not prevent the extension of reproductive activity in ewes receiving the second photoperiodic drop to the short daylength.(ABSTRACT TRUNCATED AT 250 WORDS)

The influence of phenolic compounds on the suitability of three Salix species as hosts for the willow beetle Phratora vulgatissima

Abstract: The phenolic glycosides salicin and salicortin were found to influence larval growth and development rates and adult feeding preference of Phratora vulgatissima in laboratory feeding studies. Salicortin was more toxic to larvae than salicin, and none of the third instar larvae fed on Salix viminalis leaves amended with 1.52% (fresh mass) salicortin pupated. Condensed tannins (proanthocyanadins) did not affect larval performance. It was concluded that Salix burjatica resistance to willow beetle is due to the high levels of salicortin which occur in leaves of this species.

Oxidation-reduction potentials of ferredoxin-NADP+ reductase and flavodoxin from Anabaena PCC 7119 and their electrostatic and covalent complexes.

Abstract: The oxidation-reduction potentials of ferredoxin-NADP+ reductase and flavodoxin from the cyanobacterium Anabaena PCC 7119 were determined by potentiometry. The potentials at pH 7 for the oxidized flavodoxin/flavodoxin semiquinone couple (E2) and the flavodoxin semiquinone/hydroquinone couple (E1) were -212 mV and -436 mV, respectively. E1 was independent of pH above about pH 7, but changed by approximately -60 mV/pH below about pH 6, suggesting that the fully reduced protein has a redox-linked pKa at about 6.1, similar to those of certain other flavodoxins. E2 varied by -50 mV/pH in the range pH 5-8. The redox potential for the two-electron reduction of ferredoxin-NADP+ reductase was -344 mV at pH 7 (delta Em = -30 mV/pH). In the 1:1 electrostatic complex of the two proteins titrated at pH 7, E2 was shifted by +8 mV and E1 was shifted by -25 mV; the shift in potential for the reductase was +4 mV. The potentials again shifted following treatment of the electrostatic complex with a carbodiimide, to covalently link the two proteins. By comparison with the separate proteins at pH 7, E2 for flavodoxin shifted by -21 mV and E1 shifted by +20 mV; the reductase potential shifted by +2 mV. The potentials of the proteins in the electrostatic and covalent complexes showed similar pH dependencies to those of the individual proteins. Qualitatively similar changes occurred when ferredoxin-NADP+ reductase from Anabaena variabilis was complexed with flavodoxin from Azotobacter vinelandii. The shifts in redox potential for the complexes were used with previously determined values for the dissociation constant (Kd) of the electrostatic complex of the two oxidised proteins, in order to estimate Kd values for the interaction of the different redox forms of the proteins. The calculations showed that the electrostatic complexes, formed when the proteins differ in their redox states, are stronger than those formed when both proteins are fully oxidized or fully reduced.

What Can Learning Styles Research Learn from Cognitive Psychology

Abstract: People differ from each other in the manner in which they process information from the world. These individual differences are called learning styles’. The purpose of this paper is to explore how research in this field can benefit from certain findings in cognitive psychology. Following a review of some difficulties which afflict research on learning styles (e.g. inadequate construct validation of measures), attention is drawn to two relevant findings in cognitive research: the influence of prior knowledge on learning and the potential value to learners of ‘metacognitive’ awareness. Some implications of these findings for learning styles research are then discussed.

1H and 13C NMR studies of isomerism in hydroxamic acids

Abstract: 1H and 13C NMR studies of N-methyl-substituted hydroxamic acids, RCON(CH3)OH (R = CH3, C2H5 and C6H5), show that the series exhibits cis–trans isomerism about the CN bond. The Z/E ratio increases in the series CH3 < C2H5 < n-C5H11 < n-C6H13 for a given solvent, indicating that steric interaction between R and the OH group is more important than that between R and the CH3 group. In DMSO-d6 the Z isomer is preferentially stabilized by solvation, whereas in C6D6 and toluene-d8 the unsolvated E form is thermodynamically more stable, as predicted by ab initio molecular orbital calculations. (12) At high concentrations (in CDCl3, CD2Cl2, C6D6 and toluene-d8) the E isomer may also be stabilized by intermolecular association. In the O-methyl-substituted series, RCONHOCH3 (R = CH3, C6H5), although the Z isomer predominates in all solvents, at low temperatures there is evidence for enolic forms.

The effect of estradiol, trenbolone acetate, or zeranol on growth rate, mammary development, carcass traits, and plasma estradiol concentrations of beef heifers.

Abstract: The effect of a single implantation (on d 1) with one or two long-acting, biodegradable estradiol implants (1E or 2E) on plasma estradiol concentrations in beef heifers was determined. The growth rates of these (2E) heifers, and of heifers repeatedly implanted with trenbolone acetate (TBA) or zeranol (Z) on d 1, 84, 168, and 252 of the trial, were compared to growth rates of controls. Trenbolone acetate alone was compared to TBA + 2E, and 2E was compared to 1E. At a mean age of 84 d (d 1 of experiment), 81 Hereford x Friesian heifers were allocated at random to the following treatments: Control (n = 15); TBA (n = 15); 1E (n = 12); 2E (n = 15); Z (n = 13); or TBA + 2E (n = 11). Mean live weight (kg) prior to slaughter on d 368 and hot carcass weight (kg) for heifers assigned to treatment Groups 1 to 6, respectively, were 366 and 200, 391 and 212, 374 and 201, 386 and 207, 387 and 210, and 391 and 208 (residual SD = 30.3 and 20.2). Heifers assigned to both the 2E and Z treatments were heavier on d 368 (P less than .05) and had longer teats on d 279 (P less than .05), less pelvic fat (P less than .05), and heavier kidneys (P less than .005) than control heifers. Heifers assigned to the TBA treatment had shorter teats on d 279 (P less than .001) but greater final live weight (P less than .05) and carcass weight than control heifers. Heifers given TBA alone had more pelvic fat (P less than .05) and lighter kidneys (P less than .05) than those given TBA + 2E. Mean estradiol concentrations in both the ipsilateral and contralateral jugular veins of heifers assigned to the 2E and TBA + 2E treatments, and in the ipsilateral jugular veins of heifers given 1E, were greater (P less than .05) than those in control heifers; concentrations did not decline during the experiment.

Cathepsin D concentration in breast cancer cytosols: correlation with biochemical, histological, and clinical findings

Abstract: Cathepsin D (CD, EC 3.4.23.5) is a lysosomal protease induced by estrogen in certain estrogen receptor (ER)-positive breast cancer cell lines but produced constitutively by ER-negative cell lines. Our aims in this investigation were to study the distribution of CD in human breast cancers and to relate its concentrations to various biochemical, histological, and clinical characteristics. The concentrations of CD were significantly higher in breast carcinomas than in either normal breast tissues or benign breast tumors. In primary carcinomas, CD concentrations did not correlate with the concentrations of ER or with the estrogen-inducible protease t-PA. However, CD concentrations did correlate weakly but significantly with both UK-PA antigen and UK-PA activity. Also, CD concentrations did not correlate with either tumor stage or axillary node status but did correlate significantly with tumor grade. Patients with cancers containing high concentrations of CD had a significantly shorter overall survival than did patients with low concentrations of the enzyme.

A precise U-Pb zircon age for the Inishtrahull syenitic gneiss, County Donegal, Ireland

Abstract: Smd zircon fractions from the deformed alkaline igneous complex on Inishtrahd, County Donegal, Ireland yield near-concordant U-Pb ages of 1779 * 3 Ma interpreted as dating the igneous crystallization of the gneiss9s precursor. Sm-Nd depleted mantle model ages range from 1912 Ma to 1978 Ms. The similarity of the model ages and the crystallization age indicates that the protoliths were derived from a depleted mantle source essentially uncontaminated by older crust. The isotopic data confirm previous tentative correlations of the Inishtrahull rocks with those of Islay in southwestern Scotland. Archaean crust is apparently absent from this region, consistent with recent models placing a southern limit on the Archaean along the line of the Great Glen fault zone. Pre-Caledonian orthogneisses in Scotland and Ireland, south of the Great Glen fault zone, have generally been correlated with the late Archaean Lewisian Complex of northwestern Scotland (e.g. Wilkinson 1907; McCallien 1930; Bowes & Hopgood 1975; Dixon et al. 1990) although Aftalion & Max (1987) concluded that the Lewisian was absent from the Annagh Division gneisses of north Mayo, Ireland. There are now several lines of evidence to suggest that Archaean crust may be absent southeast of the Great Glen fault zone (e.g. Fitches et al. 1990; Daly 1990; Halliday et al. 1985). A large area of pre-Caledonian basement, here termed the Rhinns Complex, is thought to be present within the fault-bounded Colonsay-West Islay block (Fig. 1; Bentley et al. 1988; Fitches et al. 1990; Marcantonio et al. 1988)), which extends from Colonsay in