Showing papers by "Cardiff University published in 1993"

Irrelevant tones produce an irrelevant speech effect : Implications for phonological coding in working memory

Abstract: A series of studies addresses the possibility that tones disrupt serial recall of visually presented material in the same way as speech. A stream of changing tones is as disruptive of visual serial recall as 4 syllables (Experiments 1 and 2). Similar effects were also shown with a repeated syllable that changed only in pitch (Experiment 3). Just as for speech, the effect of tones is not at encoding but during storage of the serial lists (Experiments 4 and 5). The results suggest that speech and tones are equipotent in their capacity to disrupt short-term memory. A «blackboard» model of working memory to account for the effects is outlined

Predictive validity of the Readiness to Change Questionnaire.

Abstract: Following the development of the Readiness to Change Questionnaire described by Rollnick et al.,1 this article reports on the predictive validity of the questionnaire among a sample of 174 male excessive drinkers identified by screening on wards of general hospitals. Relationships between patients' “stage of change” derived from questionnaires administered prior to discharge from hospital and changes in drinking behaviour at 8 weeks and 6 months follow-up are analysed. Allocated stage of change provided statistically significant relationships with drinking outcome. Multiple regression analysis showed that stage of change remained a significant predictor of changes in alcohol consumption when other possible predictors were taken into account. Two methods for allocating stage of change on the basis of questionnaire responses for use in different circumstances, a “quick” and a “refined” method, are described.

News From Behind My Hand: Gossip in Organizations:

Abstract: This paper offers an interpretation of the importance of organizational gossip. It draws together theory and research from various disciplines in order to explore four main propositions: that gossip is a phenomenon worthy of serious study/analysis; that gossip in organizations has been under-researched; that ana lysis of gossip reveals important aspects about the social organization of work; and that gossip is a social process that helps to protect and perpetuate organiza tions. It concludes that gossip is intrinsic to organizational life. Gossip offers the individual escapism and social mobility and has been undeservedly avoided in organizational analysis. Consequently, as a subject, it demands greater attention in the future in terms of theory and empirical research.

Exponential sums and the Riemann zeta function v

Abstract: A Van der Corput exponential sum is $S = \Sigma \exp (2 \pi i f(m))$, where $m$ has size $M$, the function $f(x)$ has size $T$ and $\alpha = (\log M) / \log T < 1$. There are different bounds for $S$ in different ranges for $\alpha $. In the middle range where $\alpha $ is near ${1\over 2}$, $S = O(\sqrt{M} T^{\theta + \epsilon })$. This $\theta $ bounds the exponent of growth of the Riemann zeta function on its critical line ${\rm Re} s = {1\over 2}$. Van der Corput used an iteration which changed $\alpha$ at each step. The Bombieri?Iwaniec method, whilst still based on mean squares, introduces number-theoretic ideas and problems. The Second Spacing Problem is to count the number of resonances between short intervals of the sum, when two arcs of the graph of $y = f'(x)$ coincide approximately after an automorphism of the integer lattice. In the previous paper in this series [Proc. London Math. Soc. (3) 66 (1993) 1?40] and the monograph Area, lattice points, and exponential sums we saw that coincidence implies that there is an integer point close to some ?resonance curve?, one of a family of curves in some dual space, now calculated accurately in the paper ?Resonance curves in the Bombieri?Iwaniec method?, which is to appear in Funct. Approx. Comment. Math. We turn the whole Bombieri?Iwaniec method into an axiomatised step: an upper bound for the number of integer points close to a plane curve gives a bound in the Second Spacing Problem, and a small improvement in the bound for $S$. Ends and cusps of resonance curves are treated separately. Bounds for sums of type $S$ lead to bounds for integer points close to curves, and another branching iteration. Luckily Swinnerton-Dyer's method is stronger. We improve $\theta $ from 0.156140... in the previous paper and monograph to 0.156098.... In fact $(32/205 + \epsilon , 269/410 + \epsilon)$ is an exponent pair for every $\epsilon > 0$.

Problems associated with tracheal extubation

Abstract: All anaesthetists will, at some stage, have experienced problems after tracheal extubation. Indeed, the frequency of such problems probably exceeds those relating to tracheal intubation. Whereas a large volume of the anaesthetic literature addresses problems associated with tracheal intubation, it is unusual to find discussion concerning those following extubation. This review attempts to redress this imbalance.

Mutations in the CYP11B1 gene causing congenital adrenal hyperplasia and hypertension cluster in exons 6, 7, and 8

Abstract: Steroid 11 beta-hydroxylase deficiency (failure to convert 11-deoxycortisol to cortisol) is the second most common cause of congenital adrenal hyperplasia and results in a hypertensive form of the disease. The 11 beta-hydroxylase enzyme is encoded by the CYP11B1 gene on chromosome 8q22. Two mutations in CYP11B1 have previously been reported in patients with 11 beta-hydroxylase deficiency--Arg-448-->His and a 2-bp insertion in codon 394. We now report eight previously uncharacterized mutations causing this disorder. Seven are point mutations (three nonsense and four missense) and one is a single base pair deletion causing a frameshift. We have used an in vitro transfection assay to show that all five known missense mutations causing 11 beta-hydroxylase deficiency abolish enzymatic activity. In principle, deletions of CYP11B1 could be generated by unequal crossing-over between CYP11B1 and the adjacent CYP11B2 gene, but no such deletions were found among the deficiency alleles in this study. Seven of the 10 known mutations are clustered in exons 6-8, a nonrandom distribution within the gene. This may reflect the location of functionally important amino acid residues within the enzyme or an increased tendency to develop mutations within this region of the gene.

Infant feeding, wheezing, and allergy: a prospective study.

Abstract: The determinants of wheezing and allergy were investigated in 453 children with a family history of allergic disease. A randomised controlled trial examined the effects of withholding cows' milk protein during the first three months of life and replacing cows' milk with soya milk. The children were followed up to the age of 7 years. Withholding cows' milk did not reduce the incidence of allergy or wheezing. Children who had ever been breast fed had a lower incidence of wheeze than those who had not (59% and 74% respectively). The effect persisted to age 7 years in the non-atopics only, the risk of wheeze being halved in the breast fed children after allowing for employment status, sex passive smoking, and overcrowding. Allergic disease was not associated with exposure to tobacco smoke, house dust mite antigen, or cats. Breast feeding may confer long term protection against respiratory infection.

Determinants of diagnostic hypothesis generation: effects of information, base rates, and experience.

Abstract: Physicians generated diagnostic hypotheses for case histories for which 2 types of diagnoses were plausible, with one having a higher population base rate but less severe clinical consequences than the other. The number of clinical and background symptoms pointing towards the 2 diagnoses was factorially manipulated. The order and frequency with which physicians generated hypotheses varied with the amount of relevant clinical and background information and as a function of population incidence rates, with little evidence of base rate neglect. Availability of a hypothesis, made possible by diagnosis of a similar case before, also made doctors generate this diagnosis earlier and more frequently. Physicians' experience affected hypothesis generation solely by increasing the availability of similar cases. The results are consistent with the use of similaritybased hypothesis generation processes that operate on memory for prior cases. The process of hypothesis generation in problem solving has received inadequate attention. Increasing concern with problem-solving skills in areas as diverse as medicine or manufacturing has resulted in descriptive and prescriptive accounts of human problem solving that typically divide the solution process into the subprocesses of hypothesis generation, information acquisition, and hypothesis testing. However, psychological researchers from Bruner, Goodnow, and Austin (1956) through Wason and Johnson-Laird (1972), Newell and Simon (1972) to Klayman and Ha (1987), have

High resolution imaging of galaxy cores

Abstract: Surface photometry data obtained with the Faint Object Camera of the Hubble Space Telescope in the cores of ten galaxies is presented. The major results are: (1) none of the galaxies show truly 'isothermal' cores, (2) galaxies with nuclear activity show very similar light profiles, (3) all objects show central mass densities above 10 exp 3 solar masses/cu pc3, and (4) four of the galaxies (M87, NGC 3862, NGC 4594, NGC 6251) show evidence for exceptional nuclear mass concentrations.

‘They're not the same as us’: midwives' stereotypes of South Asian descent maternity patients

Abstract: The paper examines the stereotypes of South Asian descent women held by midwives in a British hospital. The data are drawn from a small-scale ethnographic study which investigated the women's maternity experiences. The midwives’ stereotype contained four main themes: the difficulty of communicating with the women; the women's lack of compliance with care and abuse of the service; their tendency to ‘make a fuss about nothing’; and their lack of ‘normal maternal instinct’. The creation, perpetuation and effects of this negative stereotyping are examined in the light of the wider sociological research on patient typification. Black and minority ethnic patients are particularly vulnerable to negative typification because of their visibility combined with the fact that crude racial stereotypes are common in wider society. Stereotyping reflected and reinforced the view that Asian women are ‘all the same’ but ‘not like us’. Midwives used stereotypes to help them to make judgements about the kind of care different women want, need and deserve. It is therefore argued that stereotyping is a factor in the creation of the inequality in health experiences of black and minority ethnic patients.

Satellites of spiral galaxies

Abstract: We present a survey of satellites around a homogeneous set of late-type spirals with luminosity similar to that of the Milky Way. On average, we find fewer than 1.5 satellites per primary, but we argue that we can treat the survey as an ensemble and so derive the properties of the halo of a 'typical' isolated spiral. The projected density profile of the ensemble falls off approximately as 1/r. Within 50 kpc the azimuthal distribution of satellites shows some evidence for the 'Holmberg effect', an excess near the minor axis of the primary; however, at larger projected distances, the distribution appears isotropic. There is a weak but significant correlation between the size of a satellite and its distance from its primary, as expected if satellites are tidally truncated. Neither Hubble type nor spectral characteristics correlate with apparent separation. The ensemble of satellites appears to be rotating at about 30 km/s in the same direction as the galactic disk. Satellites on prograde orbits tend to be brighter than those on retrograde orbits. The typical velocity difference between a satellite and its primary shows no clear dependence either on apparent separation, or on the rotation speed of the primary. Thus our survey demonstrates that isolated spiral galaxies have massive halos that extend to many optical radii.

A 6-month home usage trial of a 1% chlorhexidine toothpaste (1). Effects on plaque, gingivitis, calculus and toothstaining.

Abstract: Research and development has been aimed towards the development of toothpastes for oral hygiene and gingival health benefits. The most effective antiplaque agent to date, chlorhexidine, is difficult to formulate into active toothpaste products. Despite some encouraging findings for experimental chlorhexidine toothpastes, there are to date no commercially available products. Based on positive findings from an experimental gingivitis study, this investigation evaluated 2 chlorhexidine toothpastes, one with fluoride, as adjuncts to oral hygiene. The study was a double-blind controlled, parallel, balanced group design, extending over 6 months. A total of 297 volunteers commenced the study after screening for a minimum acceptance level of gingivitis. At baseline, 6, 12 and 24 weeks, stain, gingival, bleeding and plaque indices were recorded, together with a calculus index at 6, 12 and 24 weeks. After a baseline prophylaxis, volunteers used the allocated product 2 x per day, with no other oral hygiene instructions given. Plaque, gingival and bleeding scores improved in all 3 groups, but to an overall significantly greater extent in the active groups. However, staining and calculus indices were significantly increased in the active compared to the control group. If the local side-effects of chlorhexidine are considered to be acceptable, these chlorhexidine toothpastes could be recommended for the same clinical applications as other chlorhexidine products. The apparent compatibility of fluoride with chlorhexidine in the one product may be pertinent to caries prevention.

Presence and possible significance of immunocytochemically demonstrable metallothionein over-expression in primary invasive ductal carcinoma of the breast.

Abstract: Metallothioneins (MTs) are ubiquitous low-molecular-weight proteins with a high affinity for heavy metal ions such as zinc, copper and cadmium. MT over-expression has been associated with resistance against anticancer drugs. In the present study we investigated 86 cases (45 cases of tumour category pT1 and 41 of category pT2) of routinely fixed and paraffin-embedded primary breast carcinomas immunohistochemically with a monoclonal antibody to an epitope of MT shared by its I and II isoforms. Immunohistochemically demonstrated MT over-expression was found in the invasive components of 7 of 32 pT1 and 17 of 28 pT2 invasive ductal carcinomas, whereas all 26 invasive lobular carcinomas gave weak or negative results. Fourteen of 17 pT2 and 2 of 7 pT1 invasive ductal carcinomas with MT over-expression developed metastases during follow-up with poor prognostic outcome. In contrast only 3 of 11 pT2 and none of the 25 pT1 cases without MT over-expression had a poor clinical course (P < 0.001). It is concluded that MT over-expression is associated with significantly poor prognosis particularly in pT2 invasive ductal breast carcinomas.

Long-Term Export Stimuli and Firm Characteristics in a European LDC:

Abstract: This study presents an investigation of factors that stimulate the decision-making process of exporting firms from a European Lesser Developed Country (LDC) to continue and sustain export activitie...

The gene for Darier's disease maps to chromosome 12q23–q24.1

Abstract: Darier's disease is a rare autosomal dominant skin disorder in which there is abnormal adhesion between keratinocytes. It appears to be associated with an increased prevalence of neuropsychiatric disorders including mental retardation and epilepsy. In addition we have previously reported a family in which major affective disorder cosegregates with Darier's disease. In the present study we have localized the gene for Darier's disease to chromosome 12q23-q24.1 by linkage analysis in five British pedigrees. We obtained a maximum two point lod score of 4.29 with marker D12S84 at zero recombination fraction. All five families showed evidence of linkage between the disease gene and markers in this region. Subsequent identification of the Darier's disease gene will provide insights into normal mechanisms of cell adhesion and may be of importance in the genetic investigation of neuropsychiatric disorders as well as elucidating the pathogenesis of Darier's disease itself.

A randomised double blind comparative study of low level laser therapy following surgical extraction of lower third molar teeth

Abstract: A randomised, double blind comparative study was undertaken to assess the efficacy of low level laser therapy in the reduction of postoperative pain and swelling in patients undergoing the extraction of bilaterally impacted mandibular third molar teeth. Healing of the sockets was also compared after 1 week. A group of 64 patients had one randomly-selected operation side treated with a semi-conductor laser and the other side with an apparently identical but non-operating model. Complete data were obtained from 52 of the 64 patients. The results showed that there was no evidence of a difference in pain and swelling on the third day after operation between laser and placebo sides. There was no difference between the two sides when they were assessed for healing 7 days after surgery.

Effects of growth with ethanol on fermentation and membrane fluidity of Saccharomyces cerevisiae.

Abstract: Saccharomyces cerevisiae HSc was grown with ethanol at concentrations up to 10% (v/v). The immediate effects of additions of externally added ethanol on CO2 production and O2 consumption of washed organisms were studied by stopped-flow membrane inlet quadrupole mass spectrometry. Fermentative activities of organisms grown with ethanol (0-5% v/v) showed similar sensitivities to inhibition by ethanol, whereas those grown with 10% (v/v) ethanol had become protected and were markedly less sensitive. The fluidity of subcellular membrane fractions was measured by determination of the temperature dependence of the rotational order parameter of the spin label 5-doxyl stearic acid (free radical) by electron spin resonance. Mitochondria prepared from yeasts grown with 0, 7, and 9% (v/v) ethanol showed similar overall fluidity, although differences in temperature-dependent behaviour indicate altered lipid composition or lateral phase separations. On the other hand the microsomal fraction from organisms grown with 9% ethanol showed a remarkable increase in fluidity. These data suggest that the protective effects of growth with ethanol near the limit of tolerance on fermentative activities may arise from altered plasma membrane fluidity properties.

Adaptive control of dynamic systems using neural networks

Abstract: An application of neural networks to the adaptive control of time varying dynamic systems is presented The essence of the approach adopted was to use a neural network model of the inverse dynamics of a plant to control that plant A control system is described which comprises a control section, a training section, an error prediction mechanism, and am adaptation assessment mechanism (a critic) The control section, which is a neural network (/spl Phi//spl circ//sup C/), is placed in series with the controlled plant, /spl Phi//spl circ//sup C/ is a recurrent backpropagation, neural network It is a direct copy of /spl Phi//spl circ/, also a recurrent backpropagation network, which is positioned across the plant to learn its inverse dynamics during operation /spl Phi//spl circ//sup C/ generates control signals to the plant, taking as its inputs the desired plant output and the feedback error The latter is produced by the error prediction mechanism to compensate for discrepancies between the desired and actual outputs due to inverse modelling uncertainties and varying environments The control performance assessment mechanism is employed to ensure that the performance of the control system improves when the weights of /spl Phi//spl circ//sup C/ are updated Simulation results are presented to illustrate the applicability of the proposed scheme to adaptive tracking control problems >

The influence of an irrelevant stimulus on two discriminations.

Abstract: In 3 experiments, the effect of adding an irrelevant stimulus to a discrimination was examined. In Experiment 1, a group of pigeons received autoshaping with an A + ABo discrimination in which 1 stimulus signaled food, A+, and a simultaneous compound of A with another stimulus, B, signaled the absence of food, ABo. A second group received similar training, except that a third stimulus, C, was present in both types of trials, AC+ABCo. The A+ABo discrimination was acquired more readily than the AC + ABCo discrimination. Experiments 2 and 3 used a negativevpatterning design, A+ ABo B+. In both experiments, this problem was mastered more readily than when an irrelevant stimulus was used to create an AC+ ABCo BC+ discrimination. The results fail to confirm predictions derived from elemental theories of conditioning

Outbreak of SRSV gastroenteritis at an international conference traced to food handled by a post-symptomatic caterer

Abstract: In an outbreak of small round structured virus (SRSV) gastroenteritis at an international AIDS conference 67 people were ill with diarrhoea or vomiting, one requiring admission to hospital. Epidemiological investigations demonstrated that the vehicle of infection was food prepared by a foodhandler who was recovering from a mild gastrointestinal illness. The food most strongly associated with illness, coronation chicken, was prepared by the food handler on the second day after symptoms ceased. The investigation confirms the view that foodhandlers may contaminate food with SRSVs after cessation of symptoms and should remain off work until at least 48 h after recovery.

Strategic and operational market segmentation: a managerial analysis

Abstract: One of the most widely used and familiar theories in marketing is market segmentation — the familiar protocols for the division of markets in a variety of ways into homogeneous groups of buyers, to form differentiated targets for marketing strategies and programmes However, the view developed in this paper is that the conventional explication of this conceptual framework ignores some of the most critical issues faced in its use in practice Uncovering these issues suggests the need to distinguish between ‘organizational levels’ in segmentation: the strategic compared with the managerial/operational; and, between the ‘internal’ and ‘external’ issues implicit and unavoidable in implementing segmentation strategies This leads to the argument that segmentation models may vary in purpose and that segment targets should be evaluated not simply in the conventional terms of external market attractiveness, but also in terms of ‘internal compatibility’ with the structure and processes of the organization in quest

Manufacturing reform and the changing role of the production supervisor -- the case of the automobile industry.

Abstract: This research assesses current changes in the nature of the supervisory role in the automobile industry. It locates these changes in the context of a transition from mass production to lean or just-in-time production. the emergence of a supervisory role, with supervisors performing critical functions as effective managers of integrated work areas is explored by focusing on two lean producers, Nissan UK and Mazda's Flat Rock plant in the US. Noting the increased responsibility of the supervisor under lean production, the extent of the supervisors’enhanced status and authority are considered. However, a case study of an established vehicle producer in the UK, involving interviews with a sample of forty supervisors draws out the structural and organizational difficulties faced by existing manufacturers in their attempts to reformulate the role of the supervisor.

Phylogenetic analysis of higher taxa of Brachiopoda

Abstract: Inferred phylogenetic relationships within the Brachiopoda have long been accepted as demonstrating repeated transitions from a phosphatic shell chemistry to a calcareous composition. This interpretation is reflected in the major subdivision of the phylum into the classes Inarticulata and Articulata. Cladistic analysis suggests, however, that the phosphatic-shelled and the calcareous-shelled Brachiopoda are sister groups that have had consistently separated shell chemistries from early in phylogenetic history. This separation is recognized in the class-rank divisions Lingulata and Calciata, the former of which includes the new Subclass Lingulatea, whilst the latter includes the new Subclass Craniformea together with the ‘articulates’ of previous classifications. □Brachiopoda, cladistic analysis, Lingulata, Lingulatea, Calciata, Craniformea.

Tobacco plants transformed with cdc25, a mitotic inducer gene from fission yeast.

Abstract: We investigated the effects of expressing a cDNA of cdc25, a mitotic inducer gene of Schizosaccharomyces pombe, on the development of transgenic tobacco plants (Nicotiana tabacum cv. Samsun). Nine independent primary transformants were regenerated containing the cdc25 sequence under the control of a cauliflower mosaic virus 35S gene promoter. Eight of the nine plants showed altered leaf morphology, the lamina being lengthened and twisted and the interveinal regions being pocketed. One of these was sacrificed for analysis of the root meristem, where the cells were found to be significantly smaller than in the wild type. The other seven were grown on and showed precocious flowering, flowers being produced earlier and in significantly greater numbers than in the wild type. They also developed abnormal flowers on short stalks developing in a position normally occupied by the most proximal axillary bud of otherwise normal flower pedicels. The presence or absence of these phenotypes in the primary transformants and in the T2 generation was associated with the presence or absence of detectable levels of cdc25 transcripts.