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Showing papers by "University of Exeter published in 1999"


Journal ArticleDOI
TL;DR: The model can handle some of the main observations in the domain of speech errors (the major empirical domain for most other theories of lexical access), and the theory opens new ways of approaching the cerebral organization of speech production by way of high-temporal-resolution imaging.
Abstract: Preparing words in speech production is normally a fast and accurate process. We generate them two or three per second in fluent conversation; and overtly naming a clear picture of an object can easily be initiated within 600 msec after picture onset. The underlying process, however, is exceedingly complex. The theory reviewed in this target article analyzes this process as staged and feed-forward. After a first stage of conceptual preparation, word generation proceeds through lexical selection, morphological and phonological encoding, phonetic encoding, and articulation itself. In addition, the speaker exerts some degree of output control, by monitoring of self-produced internal and overt speech. The core of the theory, ranging from lexical selection to the initiation of phonetic encoding, is captured in a computational model, called WEAVER++. Both the theory and the computational model have been developed in interaction with reaction time experiments, particularly in picture naming or related word production paradigms, with the aim of accounting for the real-time processing in normal word production. A comprehensive review of theory, model, and experiments is presented. The model can handle some of the main observations in the domain of speech errors (the major empirical domain for most other theories of lexical access), and the theory opens new ways of approaching the cerebral organization of speech production by way of high-temporal-resolution imaging.

3,958 citations


Journal ArticleDOI
TL;DR: In this article, the authors derived similar unit root tests for first-order autoregressive panel data models, assuming that the time dimension of the panel is fixed, and showed that the limiting distributions of the test statistics are normal.

1,138 citations


Journal ArticleDOI
TL;DR: In the gas phase, the structures of oxirane small middle dots small middle dot small middle node small middle point (SMSD) and oxiranes small middle points small middle nodes small middle positions (SMPD) have been shown to have similar properties to those of B small middle matrices as discussed by the authors.
Abstract: Similar and yet also notably different are the B small middle dot small middle dot small middle dotXY and B small middle dot small middle dot small middle dotHX complexes in the gas phase, where B is a simple Lewis base, XY is a homo- or heterodihalogen molecule, and HX is a hydrogen halide. This is demonstrated, for example, by the structures of oxirane small middle dot small middle dot small middle dotClF and oxirane small middle dot small middle dot small middle dotHCl (see picture). Both bonds are dominated by simple electrostatic interactions, but differ in terms of their propensity for nonlinearity.

593 citations


Journal ArticleDOI
TL;DR: In this paper, the authors investigated the absolute reflectivity and transmissivity associated with the single-scale microstructures of two species of Morpho butterfly and the mechanisms behind their remarkable wide-angle visibility.
Abstract: Brilliant iridescent colouring in male butterflies enables long–range conspecific communication and it has long been accepted that microstructures, rather than pigments, are responsible for this coloration. Few studies, however, explicitly relate the intra–scale microstructures to overall butterfly visibility, both in terms of reflected and transmitted intensities and viewing angles. Using a focused–laser technique, we investigated the absolute reflectivity and transmissivity associated with the single–scale microstructures of two species of Morpho butterfly and the mechanisms behind their remarkable wide–angle visibility. Measurements indicate that certain Morpho microstructures reflect up to 75% of the incident blue light over an angle range of greater than 100° in one plane and 15° in the other. We show that incorporation of a second layer of more transparent scales, above a layer of highly iridescent scales, leads to very strong diffraction, and we suggest this effect acts to increase further the angle range over which incident light is reflected. Measurements using index-matching techniques yield the complex refractive index of the cuticle material comprising the single–scale microstructure to be n = (1.56+0.01) + (0.06 ±0.01)i. This figure is required for theoretical modelling of such microstructure systems.

572 citations


Journal ArticleDOI
04 Jun 1999-Science
TL;DR: The structure of proMMP-2 reveals how the propeptide shields the catalytic cleft and that the cysteine switch may operate through cleavage of loops essential for propeptides stability.
Abstract: Matrix metalloproteinases (MMPs) catalyze extracellular matrix degradation. Control of their activity is a promising target for therapy of diseases characterized by abnormal connective tissue turnover. MMPs are expressed as latent proenzymes that are activated by proteolytic cleavage that triggers a conformational change in the propeptide (cysteine switch). The structure of proMMP-2 reveals how the propeptide shields the catalytic cleft and that the cysteine switch may operate through cleavage of loops essential for propeptide stability.

524 citations


Journal ArticleDOI
TL;DR: In this article, a rigorous methodology has been developed to aid in the identification and characterization of brittle fracture processes induced through uniaxial compressive loading, which can be easily quantified by normalizing the stresses and strains observed in progression from one stage of crack development to another.

494 citations


Journal Article
TL;DR: Oral administration of aloe vera might be a useful adjunct for lowering blood glucose in diabetic patients as well as for reducing blood lipid levels in patients with hyperlipidaemia and topical application is not an effective preventative for radiation-induced injuries.
Abstract: BACKGROUND: The use of aloe vera is being promoted for a large variety of conditions. Often general practitioners seem to know less than their patients about its alleged benefits. AIM: To define the clinical effectiveness of aloe vera, a popular herbal remedy in the United Kingdom. METHOD: Four independent literature searches were conducted in MEDLINE, EMBASE, Biosis, and the Cochrane Library. Only controlled clinical trials (on any indication) were included. There were no restrictions on the language of publication. All trials were read by both authors and data were extracted in a standardized, pre-defined manner. RESULTS: Ten studies were located. They suggest that oral administration of aloe vera might be a useful adjunct for lowering blood glucose in diabetic patients as well as for reducing blood lipid levels in patients with hyperlipidaemia. Topical application of aloe vera is not an effective preventative for radiation-induced injuries. It might be effective for genital herpes and psoriasis. Whether it promotes wound healing is unclear. There are major caveats associated with all of these statements. CONCLUSION: Even though there are some promising results, clinical effectiveness of oral or topical aloe vera is not sufficiently defined at present.

478 citations


Journal ArticleDOI
13 Feb 1999-BMJ
TL;DR: The normalising attributional style is predominant in general practice attenders and is an important cause of low rates of detection of depression and anxiety and are non-pathological in character.
Abstract: # Cross sectional study of symptom attribution and recognition of depression and anxiety in primary care {#article-title-2} Objectives : To examine the effect of patients' causal attributions of common somatic symptoms on recognition by general practitioners of cases of depression and anxiety and to test the hypothesis that normalising attributions make recognition less likely. Design : Cross sectional survey. Setting : One general practice of eight doctors in Bristol. Subjects : 305 general practice attenders. Main outcome measure : The rate of detection by general practitioners of cases of depression and anxiety as defined by the general health questionnaire. Results : Consecutive attenders completed the general health questionnaire and the symptom interpretation questionnaire, which scores style of symptom attribution along the dimensions of psychologising, somatising, and normalising. General practitioners detected depression or anxiety in 56 (36%; 95% confidence interval 28% to 44%) of the 157 patients who scored highly on the general health questionnaire. Subjects with a normalising attributional style were less likely to be detected as cases; doctors did not make any psychological diagnosis in 46 (85%; 73% to 93%) of 54 patients who had high questionnaire and high normalising scores. Those with a psychologising style were more likely to be detected; doctors did not detect 21 (38%; 25% to 52%) of 55 patients who had high questionnaire and high psychologising scores. The somatisation scale was not associated with low detection rates. This pattern of results persisted after adjustment for age, sex, general health questionnaire score, and general practitioner. Conclusions : Normalising attributions minimise symptoms and are non-pathological in character. The normalising attributional style is predominant in general practice attenders and is an important cause of low rates of detection of depression and anxiety. # Commentary: There must be limits to the medicalisation of human distress {#article-title-17}

410 citations


Journal ArticleDOI
TL;DR: This method developed a method which allowed us to conduct simple stress-strain and creep experiments on mixed and pure culture biofilms in situ by observing the structural deformations caused by changes in hydrodynamic shear stress (tau(w).
Abstract: The physical properties (rheology) of biofilms will determine the shape and mechanical stability of the biofilm structure and consequently affect both mass transfer and detachment processes Biofilm viscoelasticity is also thought to increase fluid energy losses in pipelines Yet there is very little information on the rheology of intact biofilms This is due in part to the difficulty in using conventional testing techniques The size and nature of biofilms makes them difficult to handle, while removal from a surface destroys the integrity of the sample We have developed a method which allowed us to conduct simple stress-strain and creep experiments on mixed and pure culture biofilms in situ by observing the structural deformations caused by changes in hydrodynamic shear stress (tau(w)) The biofilms were grown under turbulent pipe flow (flow velocity (u) = 1 m/s, Reynolds number (Re) = 3600, tau(w) = 5 09 N/m(2)) for between 12 and 23 days The resulting biofilms were heterogeneous and consisted of filamentous streamers that were readily deformed by changes in tau(w) At tau(w) of 1011 N/m(2) the streamers were flattened so that the thickness was reduced by 25% We estimated that the shear modulus (G) of the mixed culture biofilm was 27 N/m(2) and the apparent elastic modulus (E(app)) of both biofilms was in the range of 17 to 40 N/m(2) The biofilms behaved like elastic and viscoelastic solids below the tau(w) at which they were grown but behaved like viscoelastic fluids at elevated tau(w) The implications of these results for fluid energy losses and the processes of mass transfer and detachment are discussed

392 citations


Journal ArticleDOI
TL;DR: By using a combination of biochemical, molecular, and genetic techniques, it is demonstrated that the VTC1 locus encodes a GDP-mannose pyrophosphorylase (mannose-1-P guanyltransferase).
Abstract: Vitamin C (L-ascorbic acid; AsA) acts as a potent antioxidant and cellular reductant in plants and animals AsA has long been known to have many critical physiological roles in plants, yet its biosynthesis is only currently being defined A pathway for AsA biosynthesis that features GDP-mannose and L-galactose has recently been proposed for plants We have isolated a collection of AsA-deficient mutants of Arabidopsis thaliana that are valuable tools for testing of an AsA biosynthetic pathway The best-characterized of these mutants (vtc1) contains approximately 25% of wild-type AsA and is defective in AsA biosynthesis By using a combination of biochemical, molecular, and genetic techniques, we have demonstrated that the VTC1 locus encodes a GDP-mannose pyrophosphorylase (mannose-1-P guanyltransferase) This enzyme provides GDP-mannose, which is used for cell wall carbohydrate biosynthesis and protein glycosylation as well as for AsA biosynthesis In addition to genetically defining the first locus involved in AsA biosynthesis, this work highlights the power of using traditional mutagenesis techniques coupled with the Arabidopsis Genome Initiative to rapidly clone physiologically important genes

385 citations


Journal ArticleDOI
TL;DR: In this paper, the authors seek to gain enhanced understandings of the acquisition and development of core and generic skills in higher education and employment against a backcloth of continued pressure for their effective delivery from employers, government departments, and those responsible for the management and funding of higher education.
Abstract: The study reported here is seeking to gain enhanced understandings of the acquisition and development of core and generic skills in higher education and employment against a backcloth of continued pressure for their effective delivery from employers, government departments, and those responsible for the management and funding of higher education. This pressure appears to have had little impact so far, in part because of tutors' scepticism of the message, the messenger and its vocabulary, and in part because the skills demanded lack clarity, consistency and a recognisable theoretical base. Any empirical attempt to acquire enhanced understandings of practice thus requires the conceptualisation and development of models of generic skills and of course provision. These models are presented together with evidence of their validity, including exemplars of the patterns of course provision identified.

Journal ArticleDOI
Tia DeNora1
01 Oct 1999-Poetics
TL;DR: The question of music's social effects has a venerable tradition within social theory but has rarely been explored through empirical and ethnographic work as mentioned in this paper, which shows how music "gets into" or provides a medium for forms of social agency.

Journal ArticleDOI
TL;DR: It is concluded that the efficacy of ginseng root extract is not established beyond reasonable doubt for any of these indications and the widespread use ofginseng as a herbal remedy warrants more rigorous investigations to assess its efficacy and safety.
Abstract: Objective: Ginseng is one of the most popular herbal remedies, and a number of health claims are made for it. This systematic review provides an evaluation of the current evidence for or against the efficacy of ginseng root extract. Methods: Searches of the computerised literature databases Medline, Embase, Biosis, CISCOM and the Cochrane Library were performed to retrieve double-blind, randomised, placebo-controlled trials of ginseng root extract for any indication. Manufacturers and experts were contacted to provide additional information. There were no restrictions regarding the language of publication. The outcome and methodological quality of all trials were independently assessed by two reviewers. Results: Sixteen trials met the inclusion criteria and were reviewed. These trials related to physical performance, psychomotor performance and cognitive function, immunmodulation, diabetes mellitus and herpes simplex type-II infections. The evidence found for ginseng root extract is compelling for none of these indications. Conclusion: Based on these data, it is concluded that the efficacy of ginseng root extract is not established beyond reasonable doubt for any of these indications. The widespread use of ginseng as a herbal remedy warrants more rigorous investigations to assess its efficacy and safety.

Journal ArticleDOI
TL;DR: This work has shown that independent signal transduction pathways regulate cellular turgor during hyperosmotic stress and appressorium-mediated plant infection in Magnaporthe grisea, and that Δosm1 mutants showed a dramatically reduced ability to accumulate arabitol in the mycelium.
Abstract: The phytopathogenic fungus Magnaporthe grisea elaborates a specialized infection cell called an appressorium with which it mechanically ruptures the plant cuticle. To generate mechanical force, appressoria produce enormous hydrostatic turgor by accumulating molar concentrations of glycerol. To investigate the genetic control of cellular turgor, we analyzed the response of M. grisea to hyperosmotic stress. During acute and chronic hyperosmotic stress adaptation, M. grisea accumulates arabitol as its major compatible solute in addition to smaller quantities of glycerol. A mitogen-activated protein kinase–encoding gene OSM1 was isolated from M. grisea and shown to encode a functional homolog of HIGH-OSMOLARITY GLYCEROL1 ( HOG1 ), which encodes a mitogen-activated protein kinase that regulates cellular turgor in yeast. A null mutation of OSM1 was generated in M. grisea by targeted gene replacement, and the resulting mutants were sensitive to osmotic stress and showed morphological defects when grown under hyperosmotic conditions. M. grisea Δ osm1 mutants showed a dramatically reduced ability to accumulate arabitol in the mycelium. Surprisingly, glycerol accumulation and turgor generation in appressoria were unaltered by the Δ osm1 null mutation, and the mutants were fully pathogenic. This result indicates that independent signal transduction pathways regulate cellular turgor during hyperosmotic stress and appressorium-mediated plant infection. Consistent with this, exposure of M. grisea appressoria to external hyperosmotic stress induced OSM1 -dependent production of arabitol.

Journal ArticleDOI
TL;DR: In this article, a multivariate mixing model was employed to establish the main sources of the suspended sediment transported through the lower, non-tidal reaches of the River Ouse and one of its main tributaries, the River Wharfe, during the period 1994-1997.
Abstract: Statistically verified composite fingerprints and a multivariate mixing model have been employed to establish the main sources of the suspended sediment transported through the lower, non-tidal reaches of the River Ouse and one of its main tributaries, the River Wharfe, during the period 1994–1997. In the case of the suspended sediment samples collected from the River Ouse, the load-weighted mean contributions from uncultivated topsoil, cultivated topsoil and channel bank sources were estimated to be c. 25, 38 and 37%, respectively, while for the River Wharfe these sources contributed c. 70, 4 and 23%, respectively (c. 4% was derived from woodland topsoil). Suspended sediment samples collected during higher flows evidenced a greater contribution from channel banks than samples collected during lower flows. Source materials were also differentiated according to the three main geological source areas (Carboniferous, Permian and Triassic, and Jurassic) and their load-weighted mean contributions were estimated to be c. 24, 41 and 35% for the River Ouse and c. 91, 9 and 0% (there are no Jurassic rocks in this catchment) for the River Wharfe, respectively. When suspended sediment samples from tributary streams were used to characterize each geological source area, the equivalent results for the River Ouse were c. 30, 46 and 24%. Considering the three main tributaries that contribute to the River Ouse, the load-weighted mean contributions from the rivers Swale, Ure and Nidd were estimated to be 82, 15 and 3%, respectively. These values have been compared with estimates of the relative magnitude of the annual suspended sediment loads of these three rivers for the years 1995 and 1996 derived from continuous monitoring of discharge and turbidity. Differences between the two sets of results are ascribed to the different periods of record involved and to the timing of suspended sediment sampling relative to the overall storm hydrograph, and thus the degree to which the available samples are representative of the overall suspended sediment flux. Although a number of limitations must be recognized, the fingerprinting approach to source ascription is seen as providing valuable information regarding suspended sediment sources in the study catchments. Copyright © 1999 John Wiley & Sons, Ltd.

Journal ArticleDOI
TL;DR: In this paper, causal cognitive mapping was used to overcome cognitive biases arising from the framing of strategic decision problems, and the findings of two experimental investigations indicated that the framing bias is likely to be an important factor in strategic decision making.
Abstract: This paper reports the findings of two experimental investigations into the efficacy of a causal cognitive mapping procedure as a means for overcoming cognitive biases arising from the framing of strategic decision problems In Study 1, final year management studies undergraduate students were presented with an elaborated strategic decision scenario, under one of four experimental conditions: positively vs negatively framed decision scenarios, with prechoice vs postchoice mapping task orders (ie, participants were required to engage in cognitive mapping before or after making a decision) As predicted, participants in the postchoice mapping conditions succumbed to the framing bias whereas those in the prechoice mapping conditions did not Study 2 replicated and extended these findings in a field setting, on a sample of senior managers, using a decision scenario that closely mirrored a strategic dilemma currently facing their organization Taken together, the findings of these studies indicate that the framing bias is likely to be an important factor in strategic decision making, and suggest that cognitive mapping provides an effective means of limiting the damage accruing from this bias Copyright © 1999 John Wiley & Sons, Ltd

Journal ArticleDOI
TL;DR: In this article, the authors examine the implications of corruptibility and the potential abuse of authority for the effects and optimal design of (potentially non-linear) tax collection schemes and find that the distributional effects of evasion and corruption are unambiguously regressive under the kinds of schemes usual in practice.

Book ChapterDOI
TL;DR: In this paper, the authors investigate the impact of land use and related human activity on sediment yields and find that sediment storage within a river basin can give rise to environmental problems where sediment-associated pollutants accumulate in sediment sinks.
Abstract: Results obtained from erosion plots and catchment experiments provide clear evidence of the sensitivity of erosion rates to land use change and related human activity. Evidence for the impact of land use on the sediment yields of world rivers is less clear, although examples of rivers where sediment yields have both increased and decreased in recent decades can be identified. The apparent lack of sensitivity of river sediment loads to land use change reflects, at least in part, the buffering capacity associated with many river basins. This buffering capacity is closely related to the sediment delivery ratio of a river basin, in that basins with high sediment delivery ratios are likely to exhibit a reduced buffering capacity. Investigations of the impact of land use and related human activity on sediment yields should consider the overall sediment budget of a catchment rather than simply the sediment output. Information on the sediment budget of a drainage basin is difficult to assemble using traditional techniques, but recent developments in the application of fingerprinting techniques to establish sediment sources and in the use of environmental radionuclides, such as caesium-137 and lead-210, to document sediment storage offer considerable potential for providing such information. Sediment storage within a river basin can give rise to environmental problems where sediment-associated pollutants accumulate in sediment sinks. The accumulation of phosphorus on river floodplains as a result of overbank sedimentation can, for example, represent an important phosphorus sink.

Journal ArticleDOI
TL;DR: In this paper, the effects of grain size on the initiation and propagation thresholds of stress-induced brittle fracturing in crystalline rocks with similar mineralogical compositions, but with three different grain sizes.
Abstract: The microstructure of rock is known to influence its strength and deformation characteristics. This paper presents the results of a laboratory investigation into the effects of grain size on the initiation and propagation thresholds of stress-induced brittle fracturing in crystalline rocks with similar mineralogical compositions, but with three different grain sizes. Strain gauge and acoustic emission measurements were used to aid in the identification and characterization of the different stages of crack development in uniaxial compression. Results indicate that grain size had only a minor effect on the stress at which new cracks initiated. Crack initiation thresholds were found to be more dependent on the strength of the constituent minerals. Grain size did have a significant effect, however, in controlling the behaviour of the cracks once they began to propagate. The evidence suggests that longer grain boundaries and larger intergranular cracks, resulting from increased grain size, provide longer paths of weakness for growing cracks to propagate along. This promoted degradation of material strength once the longer cracks began to coalesce and interact. Thus, rock strength was found to decrease with increasing grain size, not by inducing crack initiation at lower stresses, but through a process where longer cracks propagating along longer planes of weakness coalesced at lower stresses.

Journal ArticleDOI
TL;DR: Thickness, cross-sectional areas, and depth of invasion in the prognosis of cutaneous melanoma, and the histogenesis and biologic behavior of human malignant melanomas of the skin.

Journal ArticleDOI
TL;DR: Leaders must build a structure within a resuscitation team in order for them to perform effectively, and an emergency leadership training programme is essential to enhance the performance of leaders and their teams.

Journal ArticleDOI
TL;DR: In this paper, the accuracy and precision of 22 load estimation procedures were assessed in the context of sampling frequency (weekly, fortnightly and monthly) and basin scales representative of the LOIS study area.
Abstract: A central objective of the LOIS Community Research Programme is to provide estimates of the land–ocean flux of suspended sediment from the LOIS study area. While high frequency (15-minute interval) suspended sediment concentration data are recorded within the programme at six tidal limit sites, infrequent (weekly–monthly) sampling undertaken by the Harmonized Monitoring (HM) Programme provides additional concentration data for 23 tidal limit sites in the LOIS study area. In order that these infrequent data can be used to generate sediment flux estimates, the accuracy and precision of 22 load estimation procedures are assessed in the context of sampling frequency (weekly, fortnightly and monthly) and basin scales representative of the LOIS study area. Sampling frequency is demonstrated to exert a significant influence on the precision of the individual procedures, with precision being inversely related to sampling frequency. Accuracy is less clearly influenced by sampling frequency, although different procedures were identified as being the most accurate at the three sampling frequencies. Basin scale is shown to exert a significant influence upon accuracy and precision, with the performance of the load estimation procedures being inversely related to basin scale. For one interpolation procedure, an error correction procedure is developed, based on the strong relationship identified in this study between the error associated with individual flux estimates and the ratio of mean sampled discharge to the mean discharge obtained from the high frequency record. This relatively high resolution error correction method is applied to HM data from eight tidal limit sites in the LOIS area, and corrects the initial annual load estimates to provide values that are considered to be more representative of rivers from the LOIS study area. Copyright © 1999 John Wiley & Sons, Ltd.

Journal ArticleDOI
TL;DR: The hypothesis that acupuncture is efficacious in the treatment of neck pain is not based on the available evidence from sound clinical trials, and further studies are justified.
Abstract: Objective. To establish whether there is evidence for or against the eYcacy of acupuncture in the treatment of neck pain. Methods. A systematic literature review was undertaken of studies that compared needle or laser acupuncture with a control procedure for the treatment of neck pain. Two reviewers independently extracted data concerning study methods, quality and outcome. Results. Overall, the outcomes of 14 randomized controlled trials were equally balanced between positive and negative. Acupuncture was superior to waiting-list in one study, and either equal or superior to physiotherapy in three studies. Needle acupuncture was not superior to indistinguishable sham control in four out of five studies. Of the eight high-quality trials, five were negative. Conclusions. In conclusion, the hypothesis that acupuncture is eYcacious in the treatment of neck pain is not based on the available evidence from sound clinical trials. Further studies are justified.

Journal ArticleDOI
TL;DR: Genetic programming is introduced, which is an evolutionary computing method that provides a ‘transparent’ and structured system identification, to rainfall-runoff modelling and is applied to flow prediction for the Kirkton catchment in Scotland.
Abstract: Planning for sustainable development of water resources relies crucially on the data available. Continuous hydrologic simulation based on conceptual models has proved to be the appropriate tool for studying rainfall-runoff processes and for providing necessary data. In recent years, artificial neural networks have emerged as a novel identification technique for the modelling of hydrological processes. However, they represent their knowledge in terms of a weight matrix that is not accessible to human understanding at present. This paper introduces genetic programming, which is an evolutionary computing method that provides a ‘transparent’ and structured system identification, to rainfall-runoff modelling. The genetic-programming approach is applied to flow prediction for the Kirkton catchment in Scotland (U.K.). The results obtained are compared to those attained using two optimally calibrated conceptual models and an artificial neural network. Correlations identified using data-driven approaches (genetic programming and neural network) are surprising in their consistency considering the relative size of the models and the number of variables included. These results also compare favourably with the conceptual models.

Journal ArticleDOI
TL;DR: This article investigated the way learners conceptualize the notion of doing well, together with their perceived reasons for their successes and failures in learning French and found that most of these learners tended to judge their success by external factors such as teacher approval, marks, or grades.
Abstract: This article describes a small-scale study into learners’ attributions for success and failure in learning French The study investigated the way in which learners conceptualise the notion of doing well, together with their perceived reasons for their successes and failures Interviews were conducted with students from 10 to 15 years of age who were learning French in the Southwest of England The results indicated that most of these learners tended to judge their success by external factors such as teacher approval, marks, or grades, and that the range of attributions increased with age Many of the attributions mentioned, however, were superficial in nature It appears that the teacher plays a significant role in the development of students’ attributions Implications are drawn with regard to language teaching and to the nature of the learning environment

Journal ArticleDOI
TL;DR: This article examined the impact of subjective experiences on reports of attitude certainty, intensity, and importance, and found that participants with moderate or extreme attitudes toward doctor-assisted suicide generated three (easy) or seven (hard) arguments that either supported or countered their opinion toward the issue prior to indicating the strength of their attitude.
Abstract: Two studies examined the impact of subjective experiences on reports of attitude certainty, intensity, and importance. In Study 1, participants with moderate or extreme attitudes toward doctor-assisted suicide generated three (easy) or seven (hard) arguments that either supported or countered their opinion toward the issue prior to indicating the strength of their attitude. Participants with moderate attitudes rated their opinions as more intense, personally important, and held with greater certainty when they had generated either a small number of supporting arguments or a large number of opposing arguments. Ratings provided by individuals with extreme attitudes were unaffected by the argument generation task. In Study 2, the impact of ease of recall on strength-related judgments was eliminated when it was rendered nondiagnostic by a misattribution manipulation. Implications of these findings for attitude strength and other judgmental phenomena are discussed.

Journal ArticleDOI
TL;DR: Overall, the existing evidence suggests that acupuncture has a role in the treatment of recurrent headaches, however, the quality and amount of evidence is not fully convincing.
Abstract: Objective: To assess whether there is evidence that acupuncture is effective in the treatment of recurrent headaches.Design: Systematic review.Study selection: Randomized or quasi-randomized clinic...

Journal ArticleDOI
TL;DR: Phenamil and bafilomycin A1 blocked silver uptake by 62 and 79% of control values, respectively, indicating that Ag+ is able to enter the apical membrane via the proton-coupled Na+ channel.
Abstract: The branchial uptake mechanism of the nonessential heavy metal silver from very dilute media by the gills of freshwater rainbow trout was investigated. At concentrations >36 nM AgNO3, silver rapidl...

Journal ArticleDOI
TL;DR: In this paper, a cross between the zinc-hyper-accumulating and -tolerant species Arabidopsis halleri and the non-hyperaccuminating, non-toleranceant speciesArabidopsis petraea was reported, and the data for tolerance were consistent with a single major gene for this character.
Abstract: The hyperaccumulation of metals by a rare class of plants is a fascinating and little understood phenomenon. No genetic analysis has been possible since no intraspecific variation is known for this character. Here, we report on crosses between the zinc-hyperaccumulating and -tolerant species Arabidopsis halleri and the non-hyperaccumulating, non-tolerant species Arabidopsis petraea. The F2 segregates for both characters and it appears that the two characters are genetically independent. The data for tolerance are consistent with a single major gene for this character (although the number of genes for hyperaccumulation cannot be determined), and is probably not very large.

Journal ArticleDOI
TL;DR: In this article, the optimal configuration of all 40 fullerene isomers of C40, using methods from molecular mechanics and tight-binding to full abinitio SCF and DFT approaches, confirms minimisation of pentagon adjacency as a major factor in relative stability.
Abstract: Optimisation of geometries of all 40 fullerene isomers of C40, using methods from molecular mechanics and tight-binding to full abinitio SCF and DFT approaches, confirms minimisation of pentagon adjacency as a major factor in relative stability. The consensus predictions of 11 out of 12 methods are that the isomer of lowest total energy is the D2 cage with the smallest possible adjacency count, and that energies rise linearly with the number of adjacencies. Quantum mechanical methods predict a slope of 80–100 kJ mol-1 per adjacency. Molecular mechanics methods are outliers, with the Tersoff potential giving a different minimum and its Brenner modification a poor correlation and much smaller penalty.