Showing papers by "University of Westminster published in 2004"

The awakening cortisol response: Methodological issues and significance

Abstract: The awakening cortisol response (ACR) is a discrete and distinctive part of the cortisol circadian cycle. In healthy adults salivary free cortisol concentrations increase by between 50 and 160% in the first 30 min immediately post-awakening (approximate average increase of 9 nmol/l, range 4-15 nmol/l, estimated to be equivalent to about three secretory episodes). However there are no agreed norms for the absolute concentrations of free cortisol in saliva either immediately post-awakening (range of 4.7-18.5 nmol/l) or 30 min post-awakening (range of 8.6-21.9 nmol/l). This review explores reasons for these discrepancies in normative data including confounding factors such as gender, age, awakening time, light and participant adherence. Although the physiological role of the ACR has not been clearly defined evidence is discussed that suggests it is under a distinct regulatory influence, different from the rest of the diurnal cortisol secretory cycle. Despite the difficulties associated with its measurement a range of studies have demonstrated an association between the ACR and psychosocial variables, stress and health. However it remains unclear whether positive affect and good health are consistently associated with larger or smaller awakening responses. It is early days in the search for the role and significance of the ACR. Its putative role in the regulation of physiological function across the day (e.g. the immune system) and its sensitivity to psychosocial variables make it a prime candidate as an intermediary linking mind and health.

The health benefits of omega-3 polyunsaturated fatty acids: a review of the evidence

Abstract: The UK dietary guidelines for cardiovascular disease acknowledge the importance of long-chain omega-3 polyunsaturated fatty acids (PUFA) - a component of fish oils - in reducing heart disease risk. At the time, it was recommended that the average n-3 PUFA intake should be increased from 0.1 to 0.2 g day(-1). However, since the publication of these guidelines, a plethora of evidence relating to the beneficial effects of n-3 PUFAs, in areas other than heart disease, has emerged. The majority of intervention studies, which found associations between various conditions and the intake of fish oils or their derivatives, used n-3 intakes well above the 0.2 g day(-1) recommended by Committee on Medical Aspects of Food Policy (COMA). Furthermore, in 2004, the Food Standards Agency changed its advice on oil-rich fish creating a discrepancy between the levels of n-3 PUFA implied by the new advice and the 1994 COMA guideline. This review will examine published evidence from observational and intervention studies relating to the health effects of n-3 PUFAs, and discuss whether the current UK recommendation for long-chain n-3 PUFA needs to be revisited.

Endothelin-1 promotes myofibroblast induction through the ETA receptor via a rac/phosphoinositide 3-kinase/Akt-dependent pathway and is essential for the enhanced contractile phenotype of fibrotic fibroblasts.

Abstract: The endothelins are a family of endothelium-derived peptides that possess a variety of functions, including vasoconstriction. Endothelin-1 (ET-1) is up-regulated during tissue repair and promotes myofibroblast contraction and migration, hence contributing to matrix remodeling during tissue repair. Here, we show that addition of ET-1 to normal lung fibroblasts induces expression of proteins that contribute to a contractile phenotype, including alpha-smooth muscle actin (alpha-SMA), ezrin, moesin, and paxillin. We confirm that ET-1 enhances the ability of lung fibroblasts to contract extracellular matrix, a function essential for tissue repair, through induction of de novo protein synthesis. Blockade of the Akt/phosphoinositide 3-kinase (PI3-kinase) pathway with LY294002 and wortmannin prevents the ability of ET-1 to induce alpha-SMA, ezrin, paxillin, and moesin and to promote matrix contraction. Dominant negative rac and Akt blocked the ability of ET-1 to promote formation of alpha-SMA stress fibers. Using specific ET-1 receptor inhibitors, we show that ET-1 induces collagen matrix contraction through the ETA, but not the ETB, receptor. Relative to normal pulmonary fibroblasts, fibroblasts cultured from scars of patients with the fibrotic disease systemic sclerosis (scleroderma) show enhanced ET-1 expression and binding. Systemic sclerosis lung fibroblasts show increased ability to contract a collagen matrix and elevated expression of the procontractile proteins alpha-SMA, ezrin, paxillin, and moesin, which are greatly reduced by antagonizing endogenous ET-1 signaling. Thus, blocking ET-1 or the PI3-kinase/Akt cascades might be beneficial in reducing scar formation in pulmonary fibrosis.

The Definition and Measurement of Creativity: What Do We Know?

Abstract: Creativity is arguably the most important element in advertising success. This article reviews the trends in creativity research and asks (1) what do we know about advertising creativity, (2) how can we measure it, and (3) how can we enhance and encourage it? After tracking its importance, this article examines how it is defined, the nature of the theories underpinning it, and the various typologies suggested by researchers. The impact of issues such as the environment, management practice, and myths on enhancing and encouraging advertising creativity are assessed. It is argued that, to encourage and enhance creativity, managers should address the effects of self-doubt, fear of risk taking, and fear of opposition and criticism.

Rethinking the concept of diaspora: mobility, connectivity and communication in a globalised world

Abstract: This article attempts a brief overview of the recent debate on diasporas. It selectively focuses on aspects of the exchanges among theorists from the early 1990s onwards and seeks to identify ways in which our understanding of the concept has evolved and attempts to offer a critical evaluation of these.

Cytotoxicity of lavender oil and its major components to human skin cells.

Abstract: Lavender (Lavandula angustifolia) oil, chiefly composed of linalyl acetate (51%) and linalool (35%), is considered to be one of the mildest of known plant essential oils and has a history in wound healing. Concerns are building about the potential for irritant or allergenic skin reactions with the use of lavender oil. This study has demonstrated that lavender oil is cytotoxic to human skin cells in vitro (endothelial cells and fibroblasts) at a concentration of 0.25% (v/v) in all cell types tested (HMEC-1, HNDF and 153BR). The major components of the oil, linalyl acetate and linalool, were also assayed under similar conditions for their cytotoxicity. The activity of linalool reflected that of the whole oil, indicating that linalool may be the active component of lavender oil. Linalyl acetate cytotoxicity was higher than that of the oil itself, suggesting suppression of its activity by an unknown factor in the oil. Membrane damage is proposed as the possible mechanism of action.

The dMARS Architecture: A Specification of the Distributed Multi-Agent Reasoning System

Abstract: The Procedural Reasoning System (PRS) is the best established agent architecture currently available It has been deployed in many major industrial applications, ranging from fault diagnosis on the space shuttle to air traffic management and business process control The theory of PRS-like systems has also been widely studied: within the intelligent agents research community, the belief-desire-intention (BDI) model of practical reasoning that underpins PRS is arguably the dominant force in the theoretical foundations of rational agency Despite the interest in PRS and BDI agents, no complete attempt has yet been made to precisely specify the behaviour of real PRS systems This has led to the development of a range of systems that claim to conform to the PRS model, but which differ from it in many important respects Our aim in this paper is to rectify this omission We provide an abstract formal model of an idealised dMARS system (the most recent implementation of the PRS architecture), which precisely defines the key data structures present within the architecture and the operations that manipulate these structures We focus in particular on dMARS plans, since these are the key tool for programming dMARS agents The specification we present will enable other implementations of PRS to be easily developed, and will serve as a benchmark against which future architectural enhancements can be evaluated

The principles and application of qualitative research.

Abstract: The present paper provides an overview of the methodological principles that underpin qualitative research and how these principles differ from those of quantitative research. It is intended to set the scene for the following papers that outline two specific approaches to the analysis of qualitative data. Within the tradition of qualitative research there are many different theoretical perspectives, of which these approaches are only two examples, but they need to be set within this broader tradition in order to highlight their specific features. Qualitative and quantitative research differ from each other in far more than their methods and data. They are each based on very different premises about both the nature of the world and the nature of our knowledge of it and how this information is generated. These approaches have implications for all aspects of research strategy, including the assessment of the quality of research findings and their wider utility or application. In relation to the latter, lack of detail in the reporting of qualitative research and small sample sizes has tended to create the impression that the findings of qualitative research have little application outside the particular research setting. While there is need for more rigor in reporting, it needs to be recognized that qualitative research can offer insights and understandings with wider relevance, although these outcomes are of a different type from those provided by quantitative research.

Crisis Communication and Recovery for the Tourism Industry: Lessons from the 2001 Foot and Mouth Disease Outbreak in the United Kingdom

Abstract: As the number of disasters and crises affecting the tourism industry increases, it is becoming necessary to understand the nature of these disasters and how to manage and limit the impacts of such incidents. This paper defines crises and disasters before discussing the area of crisis communication management and crisis communication in the tourism industry. The paper then applies the foot and mouth disease (FMD) which occurred in the United Kingdom to crisis communication theory at a national level (by examining the response of the British Tourist Authority) and at a local level (by examining the response of a District Council). The response was limited in part because of a lack of preparedness, but also due to the nature of the foot and mouth outbreak, and the speed and severity of international media coverage. Action was taken in the emergency phase of the crisis and was reactive involving inconsistency in developing key messages to stakeholders, partly due to confusion and a lack of informatio...

Violence and Democracy

Abstract: 1. Surplus violence 2. Muskets, terrorists 3. Thinking violence 4. Civilisation 5. Barbarism? 6. Why violence? 7. Uncivil wars 8. Ethics 9. Ten rules for democratizing violence.

Macular Pigment and Percentage of Body Fat.

Abstract: Purpose. To Investigate the relationship between percentage of body fat and macular pigment (MP) optical density. Methods. One hundred healthy subjects of ages between 22 and 60 years volunteered to participate in this study. MP optical density was measured psychophysically, serum lutein and zeaxanthin were quantified by HPLC, and dietary intake of lutein and zeaxanthin was assessed using a validated food frequency questionnaire. Body fat was measured by dual energy x-ray absorptiometry (DEXA); body mass index (BMI) was also calculated fro each subject. Clinical and personal details were recorded, with particular attention directed towards putative risk factors for AMD.

Neuropsychological profile of young adults with spina bifida with or without hydrocephalus

Abstract: Objectives: To determine the relative impact of hydrocephalus and spinal dysraphism in young adults on intellectual and cognitive functioning. Sub-groups of patients with congenital hydrocephalus and/or spina bifida were assessed between 1995 and 2003. The entry criteria were that individuals should have (i) intact global function, (ii) average verbal intelligence (or above), and (iii) should not have clinical depression. There were three sub-groups: patients with hydrocephalus and spina bifida, patients with hydrocephalus without spina bifida, and patients with spina bifida without hydrocephalus. Methods: Patients were neuropsychologically assessed as part of their normal clinical assessment during their annual medical review. Each individual completed a screening battery assessing global functioning, verbal intelligence, and mood. In addition they completed additional tests including measures of emotional intelligence, memory, attention, and executive function. Results were analysed to compare the performance of the patient sub-groups and to compare them to a healthy control group. Results: Patients with hydrocephalus (with or without spina bifida) were significantly impaired on the vast majority of all test scores as compared to patients with spina bifida and healthy controls. They were particularly poor on measures assessing executive function. By contrast for patients with spina bifida with no associated hydrocephalus, the significant majority of all test scores fell within the average range or above. Conclusions: The neuropsychological profile of patients with hydrocephalus is one of relative impairment and this is so whether or not spina bifida is present. In spina bifida alone, in the absence of hydrocephalus, cognitive function is relatively spared.

Effect of recovery modality on 4-hour repeated treadmill running performance and changes in physiological variables

Abstract: The purpose of this study was to compare the effectiveness of three different recovery modalities - active (ACT), passive (PAS) and contrast temperature water immersion (CTW) - on the performance of repeated treadmill running, lactate concentration and pH. Fourteen males performed two pairs of treadmill runs to exhaustion at 120% and 90% of peak running speed (PRS) over a 4-hour period. ACT, PAS or CTW was performed for 15-min after the first pair of treadmill runs. ACT consisted of running at 40% PRS, PAS consisted of standing stationary and CTW consisted of alternating between 60-s cold (10°C) and 120-s hot (42°C) water immersion. Run times were converted to time to cover set distance using critical power. Type of recovery modality did not have a significant effect on change in time to cover 400 m (Mean±SD; ACT 2.7±3.6 s, PAS 2.9±4.2 s, CTW 4.2±6.9 s), 1000 m (ACT 2.2±4.0 s, PAS 4.8±8.6 s, CTW 2.1±7.2 s) or 5000 m (ACT 1.4±29.0 s, PAS 16.7±58.5 s, CTW 11.7±33.0 s). Post exercise blood lactate concentration was lower in ACT and CTW compared with PAS. Participants reported an increased perception of recovery in the CTW compared with ACT and PAS. Blood pH was not significantly influenced by recovery modality. Data suggest both ACT and CTW reduce lactate accumulation after high intensity running, but high intensity treadmill running performance is returned to baseline 4-hours after the initial exercise bout regardless of the recovery strategy employed.

Post-traumatic stress disorder and anxiety symptoms in children exposed to the 1999 Greek earthquake.

Abstract: Five months after the Athens earthquake of September 1999, 178 children from three districts of Athens at increasing distances from the epicenter were administered questionnaires to identify symptoms of post-traumatic stress disorder (PTSD), anxiety and the extent of personal threat experienced. It was found that PTSD and anxiety symptoms were significantly related to proximity to the epicenter, exposure to threat and female gender. Age did not have a significant main effect on either anxiety or PTSD symptoms, but there were significant interactions between age and the other main variables. In the region closest to the epicenter, the youngest children reported the highest PTSD and anxiety symptom scores, but in the group furthest from the epicenter the older children reported the highest PTSD and anxiety symptom scores. These findings were discussed in relation to direct and media-imparted exposure to the earthquake.

What patients expect from complementary therapy: a qualitative study.

Abstract: Objectives. Complementary and alternative therapies have become popular with patients in Western countries. Studies have suggested motivations for patients’ choosing a wide range of complementary therapies. Data on the expectations of patients who use complementary therapy are limited. We assessed the expectations of patients who use complementary therapy.Methods. Patients attending a British National Health Service (NHS) outpatient department that provided acupuncture, osteopathy, and homoeopathy were asked to complete a qualitative survey.Results. Patients expected symptom relief, information, a holistic approach, improved quality of life, self-help advice, and wide availability of such therapies on the NHS.Conclusions. Physicians’ understanding of patients’ expectations of complementary therapies will help patients make appropriate and realistic treatment choices.

Peripheral nerves in the rat exhibit localized heterogeneity of tensile properties during limb movement.

Abstract: Peripheral nerves in the limbs stretch to accommodate changes in length during normal movement. The aim of this study was to determine how stretch is distributed along the nerve relative to local variations in mechanical properties. Deformation (strain) in joint and non-joint regions of rat median and sciatic nerves was measured in situ during limb movement using optical image analysis. In each nerve the strain was significantly greater in the joint rather than the non-joint regions (2-fold in the median nerve, 5- to 10-fold in the sciatic). In addition, this difference in strain was conserved in the median nerve ex vivo, demonstrating an in-built longitudinal heterogeneity of mechanical properties. Tensile testing of isolated samples of joint and non-joint regions of both nerves showed that joint regions were less stiff (more compliant) than their non-joint counterparts with joint: non-joint stiffness ratios of 0.5 ± 0.07 in the median nerve, and 0.8 ± 0.02 in the sciatic. However, no structural differences identified at the light microscope level in fascicular/non-fascicular tissue architecture between these two nerve regions could explain the observed tensile heterogeneity. This identification of localized functional heterogeneity in tensile properties is particularly important in understanding normal dynamic nerve physiology, provides clues to why peripheral nerve repair outcomes are variable, and suggests potential novel therapeutic targets.

Spectral analysis of randomly sampled signals: suppression of aliasing and sampler jitter

Abstract: Nonuniform sampling can facilitate digital alias-free signal processing (DASP), i.e., digital signal processing that is not affected by aliasing. This paper presents two DASP approaches for spectrum estimation of continuous-time signals. The proposed algorithms, named the weighted sample (WS) and weighted probability (WP) density functions, respectively, utilize random sampling to suppress aliasing. Both methods produce unbiased estimators of the signal spectrum. To achieve this effect, the computational procedure for each method has been suitably matched with the probability density function characterising the pseudorandom generators of the sampling instants. Both proposed methods are analyzed, and the qualities of the estimators they produce have been compared with each other. Although none of the proposed spectrum estimators is universally better than the other one, it has been shown that in practical cases, the WP estimator produces generally smaller errors than those obtained from WS estimation. A practical limitation of the approaches caused by the sampling-instant jitter is also studied. It has been proven that in the presence of jitter, the theoretically infinite bandwidths of WS and WP signal analyses are limited. The maximum frequency up to which these analyses can be performed is inversely proportional to the size of the jitter.

Cytotoxic CD4+ T cells in patients with B cell chronic lymphocytic leukemia kill via a perforin-mediated pathway

Abstract: BACKGROUND AND OBJECTIVES: B-cell chronic lymphocytic leukemia (B-CLL) is a clonal expansion of CD5+B cells that accumulate due to their uncontrolled growth and resistance to apoptosis. We have previously shown that up to 50% of blood CD4+ T cells in B-CLL patients have a cytotoxicity-related CD28- CD57+ phenotype and high content of both granzyme B and perforin (PF). In this study we investigate the cytotoxic potential of these cells against autologous B-CLL cells. DESIGN AND METHODS: Blood CD4+ or CD8+ T cells were positively isolated from B-CLL patients and cultured under a range of conditions with autologous purified B-CLL cells and with bispecific [anti-CD3 x anti-CD19] antibodies. Apoptosis of labeled B-CLL cells was assessed using the change of mitochondrial membrane potential with the fluorescent dye DiOC6 and confirmed by annexin V binding. RESULTS: There was time- and dose-dependent killing of B-CLL cells by both CD8+ and CD4+ T cells and this ranged from 6.6 - 68.0% for CD4+ cells and 6.4 - 57.8% for CD8+ cells. Almost complete inhibition by concanamycin A suggests that CD4+ T cells like CD8+ T cells induced apoptosis through a perforin-mediated pathway, but not via Fas/FasL (as indicated by lack of blocking with brefeldin A), tumor necrosis factor alpha or TRAIL. INTERPRETATION AND CONCLUSIONS: This study shows that blood CD4+PF+ T cells enriched in B-CLL patients, are able to kill autologous B-CLL cells ex vivo, through bispecific antibodies via a perforin mediated mechanism.

The advertising of pharmaceuticals direct to consumers: a critical review of the literature and debate

Abstract: Pharmaceuticals are a substantial global industry which is unusual in that with few exceptions direct-to-consumer advertising (DTCA) is not permitted. This paper examines the arguments presented for and against the use of DTCA for prescription pharmaceuticals, studies the experience of the two OECD markets which currently permit DTCA (USA and New Zealand) and reviews the positions put forward by the many interested stakeholders for and against DTCA.

Apprenticeship and Applied Theoretical Knowledge

Abstract: (2004). Apprenticeship and Applied Theoretical Knowledge. Educational Philosophy and Theory: Vol. 36, No. 5, pp. 509-521.

Rigorous analysis of delta-sigma modulators for fractional-N PLL frequency synthesis

Abstract: In this paper, rigorous analyses are presented for higher order multistage noise shaping (MASH) Delta-Sigma (/spl Delta//spl Sigma/) modulators, which are built out of cascaded first-order stages, with rational DC inputs and nonzero initial conditions. Asymptotic statistics such as the mean, average power, and autocorrelation of the binary quantizer error are formulated using a nonlinear difference equation approach. An important topic of interest considered here is the fractional-N phase-locked-loop frequency synthesis applications, where the input to the modulator has to be a rational constant. It has been mathematically shown that, regardless of the initial conditions, first-order and second-order MASH /spl Delta//spl Sigma/ modulators with rational DC inputs cannot sufficiently randomize the quantization error samples, and, therefore, are not suitable for fractional-N synthesis applications. An irrational initial condition imposed on the first accumulator of a third or higher order MASH modulator, on the other hand, annihilates the tones throughout the whole output spectrum, and provides a very smooth noise shaping. Simulation results are provided to support the theoretically derived results. Implementation issues of the irrational initial condition in the digital domain are also discussed and investigated together with the effect of finite accumulator size on the noise-shaping quality factor.

Same-Sex Marriage Revived: Feminist Critique and Legal Strategy:

Abstract: In June 2003 the UK government published proposals for a civil partnership registration scheme for same-sex couples that would confer almost all the legal rights and responsibilities of marriage. The paper discusses its provisions in the context of the debates on same-sex marriage over the past decade and argues that they hardly represent any advance on existing rights and that same-sex marriage will inevitably be won in the UK. The author herself is unenthusiastic about marriage, and concludes that lesbians and gay men should not let themselves be assimilated into a heterosexual model, but should draw attention to the potential for our relationships to act as better models for all relationships, inside or outside marriage. Copyright 2004 SAGE Publications. All rights reserved. Not for commercial use or unauthorized distribution.

Key-frame extraction algorithm using entropy difference

Abstract: The fast evolution of the digital video technology has opened new areas of research. The most important aspect will be to develop algorithms to perform video cataloguing, indexing and retrieval. The basic step is to find a way for video abstraction, as this will help us more for browsing a large set of video data with sufficient content representation. In this paper we present an overview of the current key-frame extraction algorithms. We propose the Entropy-Difference, an algorithm that performs spatial frame segmentation. We present evaluation of the algorithm on several video clips. Quantitative results show that the algorithm is successful in helping annotators automatically identify video key-frames

Development of a clinical data warehouse

Abstract: There is increasing worldwide awareness that bionics and artificial intelligence will play an important role in microbial analysis. An intelligent data-warehouse system consisting of an odour generation mechanism, rapid volatile delivery and recovery system, and a classifier system based on neural networks and genetic algorithms have been applied as part of a microbial analysis. The microbiological warehouse environment has, also adopted the concept of fusion of multiple classifiers dedicated to specific feature parameters. The experimental results confirm the soundness of the presented methods.