Showing papers by "Keele University published in 1993"
1,054 citations
TL;DR: It is now widely accepted that apoptosis is a genedirected process and can be seen, alongside more familiar gene-directed processes like differentiation, as part of the repertoire available to the cell to respond to external and internal stimuli.
940 citations
TL;DR: No significant difference in the point prevalence of depression at six months was found between the postnatal and control women, nor in the six-month period prevalence, but a threefold higher rate of onset of depression was found within five weeks of childbirth.
Abstract: In a two-stage screening procedure using the Edinburgh Postnatal Depression Scale and Goldberg's Standardised Psychiatric Interview, 232 women six months after delivery were compared with control women individually matched for age, marital status and number of children, obtained from general practitioner lists, who were not pregnant nor had had a baby in the previous 12 months. No significant difference in the point prevalence of depression at six months was found between the postnatal (9.1%) and control women (8.2%) nor in the six-month period prevalence (13.8% postnatal, 13.4% controls), but a threefold higher rate of onset of depression was found within five weeks of childbirth. The possible explanations relate to the long duration of depression in women with young children, and the stressful effect of childbirth and its psychosocial sequelae.
776 citations
311 citations
TL;DR: In this paper, the authors determined the dissociation constant of NH4NO3(c, IV) to NH3(g) and HNO3g using literature data from a variety of sources.
277 citations
TL;DR: In this article, a method for incorporating the shell model of ionic polarizability in molecular dynamics simulations is proposed, where the shells are given a small mass and their motion integrated in the same way as that of the cores, by numerical integration of the classical equations of motion.
Abstract: A method is introduced by which molecular dynamics simulations of ionic materials can incorporate the shell model of ionic polarizability. The shells are given a small mass and their motion integrated in the same way as that of the cores, by numerical integration of the classical equations of motion. The authors argue that results should be in agreement with the conventional massless shell model providing that the frequency of the spring linking the core and the shell is much higher than the lattice vibrational frequencies. It is always possible to satisfy this condition by making an appropriate choice of the shell mass. The method is tested in simulations of diffusion in molten NaCl and superionic CaF2, and of phonon frequencies in MgO. The method works well, is easy to implement, and is computationally efficient.
224 citations
TL;DR: In this paper, it was shown that the pool of singlet oxygen detected by steady-state luminescence at 1270 nm and quenched by azide and water is located in the bulk medium rather than in the protein matrix of the reaction centre.
199 citations
TL;DR: In this paper, a synthesis of business history and organization studies is developed, using the historical concept of invented tradition in conjunction with the social cognition biases identified by organizational culture, and the major part of the article demonstrates how Cadbury, a British confectionery company well known for its Quaker traditions, invented its corporate culture by attributing significance to the Quaker beliefs of the Cadbury family retrospectively.
Abstract: The concept of culture promised to make organization studies more historical. This promise has not been fulfilled. Possible reasons for the failure to integrate business history and organization studies are explored and a synthesis developed, using the historical concept of invented tradition in conjunction with the social cognition biases identified by organizational culture. The major part of the article then demonstrates how Cadbury, a British confectionery company well known for its Quaker traditions, invented its corporate culture by attributing significance to the Quaker beliefs of the Cadbury family retrospectively. A history is reconstructed, mainly from published sources, to demonstrate how the histories constructed by the firm, including a centenary celebration in 1931, were part of the process of giving meaning to the firm's labor-management institutions.
190 citations
TL;DR: The human visual pathway contains a mechanism that is sensitive to rate of expansion rather independently of time to contact or absolute change in size, which can be explained by a small modification to a model previously put forward to account for data on threshold elevations and aftereffects caused by adapting to changing-size stimulation.
175 citations
TL;DR: In the past, discussion about grass-grazer interactions has tended to centre on whether they represent some sort of mutualism, however, intense grazing pressure is more likely to have selected for the presence of various antiherbivore defences in grasses.
Abstract: In the past, discussion about grass-grazer interactions has tended to centre on whether they represent some sort of mutualism. However, intense grazing pressure is more likely to have selected for the presence of various antiherbivore defences in grasses. Many grasses contain silica, which functions in some cases as a physical defence. Others contain various secondary compounds which have negative effects on both invertebrate and vertebrate herbivores. Much recent evidence suggests that plants with higher levels of these defences deter herbivores more effectively than plants without them.
168 citations
TL;DR: In this paper, the authors showed that collagen fibres do not need to be continuous to reinforce the annulus fibrosus, and that 15mm-wide samples of annulus retain about 44% of their in situ stiffness and strength when stretched vertically.
Abstract: Part I of this study showed that collagen fibres do need not need to be continuous to reinforce the annulus fibrosus, and that 15-mm-wide samples of annulus retain about 44% of their in situ stiffness and strength when stretched vertically. Part II investigated the ultimate tensile strength (UTS) and fatigue life of such samples. Vertical slices, 5 mm thick and 30 mm wide, were cut from the anterior and posterior margins of the annulus and adjacent vertebral bodies. Each slice was divided sagittally to obtain a matched pair of specimens. The bony ends of each specimen were secured in a materials testing machine so that the annulus could be stretched vertically, as occurs during bending movements of the spine in life. One of each pair of specimens was stretched to failure to obtain its UTS; the other was cyclically loaded at some fraction of the UTS until failure occurred. Tensile failure started with the hyaline cartilage end-plate being stripped off the underlying bone and ended with the most peripheral annular fibres pulling out of the matrix. The estimated in situ strength in the vertical direction was 3.9 MPa for the anterior annulus and 8.6 MPa for the posterior annulus. Fatigue failure could occur in less than 10000 cycles if the tensile force exceeded 45% of the UTS. The results explain why radial fissures often fail to penetrate the peripheral annulus. When compared with in vivo measurements of spinal loading, they suggest that repetitive forward bending movements could cause fatigue failure of the posterior annulus.
TL;DR: In this paper, the authors examined a research model developed to understand work satisfactions and emotional and physical well-being among police officers and found that work stressors and psychological burnout were fairly consistently and significantly related to levels of self-reported work attitudes and emotions.
Abstract: This study examined a research model developed to understand work satisfactions and emotional and physical well-being among police officers. Data were collected from 828 men and women in police work using questionnaires completed anonymously. Although considerable diversity was present in the sample, a majority were male constables in their early careers. Five groups of predictor variables identified in previous research were considered: individual demographic and situational variables, work stressors, work-family conflict, coping responses, and psychological burnout components. Work stressors and psychological burnout were fairly consistently and significantly related to levels of self-reported work attitudes and emotional and physical well-being. Somewhat surprisingly, work-family conflict and individual coping responses were generally unrelated to measures of work attitudes and self-reported emotional and physical well-being.
TL;DR: In this article, the moral world of television crime stories is said to have a long goodbye, and moral tales and social theory entertaining the crisis are entertaining the television and moral enterprise television, dramatization and the fear of crime a piece of the action.
Abstract: Crime, television and social anxiety moral tales and social theory entertaining the crisis? television and moral enterprise television, dramatization and the fear of crime a piece of the action - approaches to content in television crime drama the moral world of television crime stories a long goodbye.
TL;DR: Application of the model has permitted us to extend the linear operating range of the PC system and to quantify accurately the response of the system in its nonlinear operating regime, thus increasing the useful dynamic range ofThe system by 1 order of magnitude.
Abstract: A useful analytic model describing the response of a photon-counting (PC) system has been developed. The model describes the nonlinear count loss and apparent count gain arising from the overlap of photomultiplier tube (PMT) pulses, taking into account the distribution in amplitude of the PMT output pulses and the effect of the pulse-height discrimination threshold. Comparisons between the model and Monte Carlo simulations show excellent agreement. The model has been applied to a PC lidar system with favorable results. Application of the model has permitted us to extend the linear operating range of the PC system and to quantify accurately the response of the system in its nonlinear operating regime, thus increasing the useful dynamic range of the system by 1 order of magnitude.
TL;DR: 10 organizational-level interventions to reduce stress at work which have been examined in various field studies were generally found to have positive effects, and, given the limited success of individual- level interventions in addressing occupational sources of stress, should be encouraged.
Abstract: Occupational stress research continues to grow, and is increasingly being used to inform national policy on worker health and well-being. Most models of occupational stress emphasize notions of person-environment fit. Two approaches for intervention to minimize adverse consequences of occupational stress follow from such models. One emphasizes the strengthening and enhancement of indwiduals and their resources, the other emphasizes the reduction ofcommon workplace-based sources ofoccupational stress. This paper reviews 10 organizational-level interventions to reduce stress at work which have been examined in various field studies. These interventions were generally found to have positive effects, and, given the limited success of individual-level interventions in addressing occupational sources of stress, should be encouraged.
TL;DR: In this article, the authors used circular dichroism spectroscopy to confirm that, in a membrane-mimicking solvent, AβP(1−40) adopts a partially helical conformation and demonstrated the loss of this structure in the presence of physiologically relevant concentrations of aluminium.
TL;DR: In this paper, the ac electrical properties of copper phthalocyanine (CuPc) thin films have been studied in the frequency range 10 2 −2 × 10 4 Hz and in the temperature range 173-360 K.
TL;DR: In this paper, the authors developed a new code for performing molecular dynamics simulations of ionic materials, in which electronic polarization is included via the shell model, which is used to study superionic conduction in CaF2, which has previously been studied by conventional rigid ion molecular dynamics.
Abstract: The authors have developed a new code for performing molecular dynamics simulations of ionic materials, in which electronic polarization is included via the shell model. Key features of the method are the use of the conjugate-gradients technique for relaxing the shells at each step, and a new device for ensuring energy conservation. The new code is used to study superionic conduction in CaF2, which has previously been studied by conventional rigid-ion molecular dynamics. For both static and dynamic quantities, the modifications caused by explicit inclusion of electronic polarizability are remarkably small.
TL;DR: In this article, the properties of the lowest triplet of C 60 in benzene at room temperature were determined, including its absorption spectrum between 300 and 1600 nm, its molar absorption coefficient (ϵ T = 20200 ± 2000 dm 3 mol −1 cm −1 at 750 nm) and its quantum yield of formation (Φ T = 0.88 ± 0.15).
TL;DR: It is concluded that bradycardia, apnea, and hypoxemia are closely linked phenomena in preterm infants.
Abstract: The pathogenesis of bradycardias in preterm infants is poorly understood. Because their pathogenesis may involve both apnea and hypoxemia, we set out to analyze the proportion of bradycardias that were associated with an apneic pause and/or a fall in arterial oxygen saturation (SaO2), and the temporal sequence of the three phenomena, in overnight tape recordings of SaO2 (Nellcor N100 in beat-to-beat mode), breathing movements, nasal airflow, and ECG in 80 preterm infants at the time of discharge from hospital. A bradycardia was defined as a fall in heart rate of > or = 33% from baseline for > or = 4 s, an apneic pause as a cessation of breathing movements and/or airflow for > or = 4 s, and a desaturation as a fall in SaO2 to < or = 80%. A total of 193 bradycardias were found in 46 (58%) of the recordings (median, three per recording; range 1-18). There was a close relationship between bradycardias, apneic pauses, and desaturations: 83% of bradycardias were associated with apneic pauses and 86% with desaturations. Where all three phenomena occurred in combination, the time from the onset of apnea to the onset of the fall in SaO2 was shorter (median interval, 0.8 s; range -4.9-+ 11.5 s) than that from the onset of apnea to the onset of bradycardia (median, 4.8 s; range -4.0-+ 14.0 s). Hence, most bradycardias (86%) commenced after the onset of the fall in SaO2. We conclude that bradycardia, apnea, and hypoxemia are closely linked phenomena in preterm infants.
TL;DR: In this paper, the authors used pseudopotentials to study the structure and energy of the basal-plane surface of α-Al2O3 and showed that surface relaxations are very large and lead to a reduction of the surface energy by over a factor of two.
TL;DR: In this paper, the authors used hydrometric measurements and geochemical hydrograph separation techniques to determine the processes that govern stormflow production in a forested swamp situated in a regional groundwater discharge zone.
TL;DR: A mutant is identified which accumulates epicuticular aldehydes and is severely deficient in alkanes on its surface and seven other mutants had only slightly different epicUTicular wax compositions compared to those of wild type plants.
TL;DR: The aberrant crypt focus (ACF) assay is used to test and develop hypotheses linking diet and colon cancer, which include a risk associated with 5-hydroxymethyl-2-furaldehyde in caramelized sugar, a Risk associated with some factor in thermolyzed casein, and a single nutrient boluses of sucrose and fructose.
Abstract: We have used the aberrant crypt focus (ACF) assay to test and develop hypotheses linking diet and colon cancer. The hypotheses were suggested by epidemiological studies that identified possible dietary factors associated with colorectal cancer risk. The ACF assay was used to quantitate the effect of the dietary factors on the initiation and growth of these putative precursors of colon cancers in experimental animals. Using this approach we have developed 3 new hypotheses for the role of diet in colorectal cancer. These are (1) a risk associated with 5-hydroxymethyl-2-furaldehyde in caramelized sugar, (2) a risk associated with some factor in thermolyzed casein, and (3) a risk associated with single nutrient boluses of sucrose and fructose. The importance of these hypotheses has still to be tested in long term carcinogenesis experiments, in analytic epidemiology studies and then, perhaps, in intervention trials.
TL;DR: This work advocates knowledge acquisition practices and tools that facilitate active collaboration between expert and knowledge engineer, that exploit a serviceable theory in their application, and that support knowledge‐based system development from a life‐cycle perspective.
Abstract: Knowledge acquisition is a constructive modeling process, not simply a matter of “expertise transfer.” Consistent with this perspective, we advocate knowledge acquisition practices and tools that facilitate active collaboration between expert and knowledge engineer, that exploit a serviceable theory in their application, and that support knowledge-based system development from a life-cycle perspective. A constructivist theory of knowledge is offered as a plausible theoretical foundation for knowledge acquisition and as an effective practical approach to the dynamics of modeling. In this view, human experts construct knowledge from their own personal experiences while interacting with their social constituencies (e.g., supervisors, colleagues, clients patients) in their niche of expertise. Knowledge acquisition is presented as a cooperative enterprise in which the knowledge engineer and expert collaborate in constructing an explicit model of problem solving in a specific domain. From this perspective, the agenda for the knowledge acquisition research community includes developing tools and methods to aid experts in their efforts to express, elaborate, and improve their models of the domain. This functional view of expertise helps account for several problems that typically arise in practical knowledge acquisition projects, many of which stem directly from the inadequacies of representations used at various stages of system development. to counter these problems, we emphasize the use of mediating representations as a means of communication between expert and knowledge engineer, and intermediate representations to help bridge the gap between the mediating representations themselves, as well as between the mediating representations and a particular implementation formalism. © 1993 John Wiley & Sons, Inc.
TL;DR: In this paper, the authors used an input-output model to examine the production of carbon dioxide emissions in the UK and explored the effect of varying the balance between fossil fuel and other forms of electricity generation, and of changing the composition of final demand for goods and services.
TL;DR: It is reported that the apparent direction of motion in depth of a monocularly-camouflaged target can be varied by altering the ratio phi/gamma.
13 Apr 1993
TL;DR: In this article, experimental methods and theoretical models that enable interaction effects in particulate systems to be examined are discussed, and two distinct regimes of behavior are considered: weak and strong interaction.
Abstract: Experimental methods and theoretical models that enable interaction effects in particulate systems to be examined are discussed. Two distinct regimes of behavior are considered. The weak interaction case is examined and it is shown that, in general, low-field susceptibility studies can be used to establish the effects of interactions only if care is taken to exclude other effects such as progressive blocking. The strong interaction regime is considered, and the use of remanence curves, chi /sub irr/ curves and the delta I(H) plot in the study of interaction effects is described. For both regimes, the use of numerical models in this area is reviewed. >
TL;DR: In this article, the authors presented new results from the analysis of 55 high-resolution spectra of V404 Cyg (the optical counterpart of the X-ray transient GS 2023+338) taken in 1991 July-August which, added to our 1990 July Hα spectra, established the most complete spectroscopic data base in quiescence of this new black hole candidate.
Abstract: We present new results from the analysis of 55 high-resolution spectra of V404 Cyg (the optical counterpart of the X-ray transient GS 2023+338) taken in 1991 July-August which, added to our 1990 July Hα spectra, establish the most complete spectroscopic data base in quiescence of this new black hole candidate. In addition, we present multicolour (optical and infrared) and white-light photometry, the latter being partially simultaneous with the spectroscopy. We detect V404 Cyg B through its metallic absorption lines in the vicinity of Hα, which classify it as a K0 (±1) III-V star. The absorption lines are partially filled in by a flat continuum, probably an accretion disc, which contributes ≤10 per cent of the total flux in R
TL;DR: The results indicate that seven variables were independently and significantly related to better compliance: accurate knowledge of regimen; belief in the importance of taking tablets exactly as prescribed; low resentment of time spent waiting to see the doctor; less fear of illness; ability to read the label on the bottle; and living with a relative.
Abstract: To compare compliance in older adults with that of younger people, two studies investigated general practice patients taking either a short course of antibiotics or long-term medication. These studies examined the effects of age on compliance separately from other factors such as memory, domestic conditions, health beliefs, numbers of drugs being taken, etc. The results indicate that seven variables were independently and significantly related to better compliance: accurate knowledge of regimen; belief in the importance of taking tablets exactly as prescribed; low resentment of time spent waiting to see the doctor; less fear of illness; ability to read the label on the bottle; understanding what the doctor has said; and living with a relative. Age as such was not a factor affecting compliance. The results are discussed in terms of the potential influence of GPs in improving compliance in their patients.