Showing papers by "University of Liverpool published in 2000"

Learning from Abroad: The Role of Policy Transfer in Contemporary Policy‐Making

Abstract: In recent years there has been a growing body of literature within political science and international studies that directly and indirectly uses, discusses and analyzes the processes involved in lesson-drawing, policy convergence, policy diffusion and policy transfer. While the terminology and focus often vary, all of these studies are concerned with a similar process in which knowledge about policies, administrative arrangements, institutions and ideas in one political setting (past or present) is used in the development of policies, administrative arrangements, institutions and ideas in another political setting. Given that this is a growing phenomenon, it is something that anyone studying public policy needs to consider. As such, this article is divided into four major sections. The first section briefly considers the extent of, and reasons for, the growth of policy transfer. The second section then outlines a framework for the analysis of transfer. From here a third section presents a continuum for distinguishing between different types of policy transfer. Finally, the last section addresses the relationship between policy transfer and policy “failure.”

Testing for Stationarity in Heterogeneous Panel Data

Abstract: This paper proposes a residual-based Lagrange multiplier (LM) test for a null that the individual observed series are stationary around a deterministic level or around a deterministic trend against the alternative of a unit root in panel data. The tests which are asymptotically similar under the null, belong to the locally best invariant (LBI) test statistics. The asymptotic distributions of the statistics are derived under the null and are shown to be normally distributed. Finite sample sizes and powers are considered in a Monte Carlo experiment. The empirical sizes of the tests are close to the true size even in small samples. The testing procedure is easy to apply, including, to panel data models with fixed effects, individual deterministic trends and heterogeneous errors across cross-sections. It is also shown how to apply the tests to the more general case of serially correlated disturbance terms.

The Gaia Methodology for Agent-Oriented Analysis and Design

Abstract: This article presents Gaia: a methodology for agent-oriented analysis and design. The Gaia methodology is both general, in that it is applicable to a wide range of multi-agent systems, and comprehensive, in that it deals with both the macro-level (societal) and the micro-level (agent) aspects of systems. Gaia is founded on the view of a multi-agent system as a computational organisation consisting of various interacting roles. We illustrate Gaia through a case study (an agent-based business process management system).

Indoor air pollution in developing countries: a major environmental and public health challenge

Abstract: Around 50% of people, almost all in developing countries, rely on coal and biomass in the form of wood, dung and crop residues for domestic energy. These materials are typically burnt in simple stoves with very incomplete combustion. Consequently, women and young children are exposed to high levels of indoor air pollution every day. There is consistent evidence that indoor air pollution increases the risk of chronic obstructive pulmonary disease and of acute respiratory infections in childhood, the most important cause of death among children under 5 years of age in developing countries. Evidence also exists of associations with low birth weight, increased infant and perinatal mortality, pulmonary tuberculosis, nasopharyngeal and laryngeal cancer, cataract, and, specifically in respect of the use of coal, with lung cancer. Conflicting evidence exists with regard to asthma. All studies are observational and very few have measured exposure directly, while a substantial proportion have not dealt with confounding. As a result, risk estimates are poorly quantified and may be biased. Exposure to indoor air pollution may be responsible for nearly 2 million excess deaths in developing countries and for some 4% of the global burden of disease. Indoor air pollution is a major global public health threat requiring greatly increased efforts in the areas of research and policy-making. Research on its health effects should be strengthened, particularly in relation to tuberculosis and acute lower respiratory infections. A more systematic approach to the development and evaluation of interventions is desirable, with clearer recognition of the interrelationships between poverty and dependence on polluting fuels.

Polymer synthesis and processing using supercritical carbon dioxide

Abstract: Carbon dioxide is a clean and versatile solvent for the synthesis and processing of a range of materials. This review focuses on recent advances in polymer synthesis and processing using liquid and supercritical CO2. The synthetic techniques discussed include homogeneous solution polymerisation, precipitation polymerisation, dispersion and emulsion polymerisation, and bulk polycondensation. The formation of porous polymers and polymer blends is also considered, and the specific advantages of CO2 in these processes are evaluated in each case. The use of CO2 as a solvent for polymer processing is reviewed from a materials perspective, with particular attention being given to the formation of polymers with well defined morphologies. The variable solvent strength associated with supercritical fluids has been utilised in areas such as polymer fractionation and polymer extraction. Plasticisation phenomena have been exploited for the impregnation and heterogeneous chemical modification of polymeric materials. The formation of microcellular polymer foams by pressure induced phase separation is considered, as is the use of CO2 for polymer particle formation, spray coating, and microlithography. The aim of the review is to highlight the wide range of opportunities available to the materials chemist through the use of carbon dioxide as an alternative solvent.

Systematic review of studies of patient satisfaction with telemedicine.

Abstract: Objective: To review research into patient satisfaction with teleconsultation, specifically clinical consultations between healthcare providers and patients involving real time interactive video. Design: Systematic review of telemedicine satisfaction studies. Electronic databases searched include Medline, Embase, Science Citation Index, Social Sciences Citation Index, Arts and Humanities Citation Index, and the TIE (Telemedicine Information Exchange) database. Subjects: Studies conducted worldwide and published between 1966 and 1998. Main outcome measures: Quality of evidence about patient satisfaction. Results: 32 studies were identified. Study methods used were simple survey instruments (26 studies), exact methods not specified (5), and qualitative methods (1). Study designs were randomised controlled trial (1 trial); random patient selection (2); case-control (1); and selection criteria not specified or participants represented consecutive referrals, convenience samples, or volunteers (28). Sample sizes were20 (10 trials),100 (14), >100 (7), and not specified (1). All studies reported good levels of patient satisfaction. Qualitative analysis revealed methodological problems with all the published work. Even so, important issues were highlighted that merit further investigation. There is a paucity of data examining patients9 perceptions or the effects of this mode of healthcare delivery on the interaction between providers and clients. Conclusions: Methodological deficiencies (low sample sizes, context, and study designs) of the published research limit the generalisability of the findings. The studies suggest that teleconsultation is acceptable to patients in a variety of circumstances, but issues relating to patient satisfaction require further exploration from the perspective of both clients and providers.

A nanometre-scale electronic switch consisting of a metal cluster and redox-addressable groups

Abstract: So-called bottom-up fabrication methods aim to assemble and integrate molecular components exhibiting specific functions into electronic devices that are orders of magnitude smaller than can be fabricated by lithographic techniques. Fundamental to the success of the bottom-up approach is the ability to control electron transport across molecular components. Organic molecules containing redox centres-chemical species whose oxidation number, and hence electronic structure, can be changed reversibly-support resonant tunnelling and display promising functional behaviour when sandwiched as molecular layers between electrical contacts, but their integration into more complex assemblies remains challenging. For this reason, functionalized metal nanoparticles have attracted much interest: they exhibit single-electron characteristics (such as quantized capacitance charging) and can be organized through simple self-assembly methods into well ordered structures, with the nanoparticles at controlled locations. Here we report scanning tunnelling microscopy measurements showing that organic molecules containing redox centres can be used to attach metal nanoparticles to electrode surfaces and so control the electron transport between them. Our system consists of gold nanoclusters a few nanometres across and functionalized with polymethylene chains that carry a central, reversibly reducible bipyridinium moiety. We expect that the ability to electronically contact metal nanoparticles via redox-active molecules, and to alter profoundly their tunnelling properties by charge injection into these molecules, can form the basis for a range of nanoscale electronic switches.

Dynamic Mechanical Conditioning of Collagen-Gel Blood Vessel Constructs Induces Remodeling In Vitro

Abstract: Dynamic mechanical conditioning is investigated as a means of improving the mechanical properties of tissue-engineered blood vessel constructs composed of living cells embedded in a collagen-gel scaffold. This approach attempts to elicit a unique response from the embedded cells so as to reorganize their surrounding matrix, thus improving the overall mechanical stability of the constructs. Mechanical conditioning, in the form of cyclic strain, was applied to the tubular constructs at a frequency of 1 Hz for 4 and 8 days. The response to conditioning thus evinced involved increased contraction and mechanical strength, as compared to statically cultured controls. Significant increases in ultimate stress and material modulus were seen over an 8 day culture period. Accompanying morphological changes showed increased circumferential orientation in response to the cyclic stimulus. We conclude that dynamic mechanical conditioning during tissue culture leads to an improvement in the properties of tissue-engineered blood vessel constructs in terms of mechanical strength and histological organization. This concept, in conjunction with a proper biochemical environment, could present a better model for engineering vascular constructs. © 2000 Biomedical Engineering Society. PAC00: 8719Rr, 8714Ee, 8718-h, 8768+z

A Versatile Family of Interconvertible Microporous Chiral Molecular Frameworks: The First Example of Ligand Control of Network Chirality

Abstract: Two families of molecular frameworks which grow as homochiral single crystals are described. Both consist of multiple interpenetration of the three-connected chiral (10,3)-a (Y*) network and result from the tridentate coordination of the 1,3,5-benzenetricarboxylate (btc) ligand to octahedral metal centers which act as linear connectors. The nature of the interpenetration is controlled by the auxiliary ligands bound in the equatorial plane of the metal center. Ethylene glycol (eg) binds in a unidentate fashion to form phase A which has 28% accessible solvent volume and contains four interpenetrating (10,3)-a networks. 1,2-Propanediol (1,2-pd) coordinates as a bidentate ligand to yield a phase B with a greatly enhanced 51% of solvent accessible volume, because only two (distorted) (10,3)-a‘ networks interpenetrate. Ligands in the void space and bound to the metal center can both be liberated thermally: the kinetics of this process allow isolation of microporous desolvated crystalline A and B. The porous ph...

Extended surface chirality from supramolecular assemblies of adsorbed chiral molecules

Abstract: The increasing demand of the chemical and pharmaceutical industries for enantiomerically pure compounds has spurred the development of a range of so-called 'chiral technologies' (ref. 1), which aim to exert the ultimate control over a chemical reaction by directing its enantioselectivity. Heterogeneous enantioselective catalysis is particularly attractive because it allows the production and ready separation of large quantities of chiral product while using only small quantities of catalyst. Heterogeneous enantioselectivity is usually induced by adsorbing chiral molecules onto catalytically active surfaces. A mimic of one such catalyst is formed by adsorbing (R,R)-tartaric acid molecules on Cu(110) surfaces: this generates a variety of surface phases, of which only one is potentially catalytically active, and leaves the question of how adsorbed chiral molecules give rise to enantioselectivity. Here we show that the active phase consists of extended supramolecular assemblies of adsorbed (R,R)-tartaric acid, which destroy existing symmetry elements of the underlying metal and directly bestow chirality to the modified surface. The adsorbed assemblies create chiral 'channels' exposing bare metal atoms, and it is these chiral spaces that we believe to be responsible for imparting enantioselectivity, by forcing the orientation of reactant molecules docking onto catalytically active metal sites. Our findings demonstrate that it is possible to sustain a single chiral domain across an extended surface--provided that reflection domains of opposite handedness are removed by a rigid and chiral local adsorption geometry, and that inequivalent rotation domains are removed by successful matching of the rotational symmetry of the adsorbed molecule with that of the underlying metal surface.

Convergent neuroanatomical and behavioural evidence of an amygdala hypothesis of autism.

Abstract: In this study we report a convergence of behavioural and neuroanatomical evidence in support of an amygdala hypothesis of autism. We find that people with high-functioning autism (HFA) show neuropsychological profiles characteristic of the effects of amygdala damage, in particular selective impairment in the recognition of facial expressions of fear, perception of eye-gaze direction, and recognition memory for faces. Using quantitative magnetic resonance (MR) image analysis techniques, we find that the same individuals also show abnormalities of medial temporal lobe (MTL) brain structure, notably bilaterally enlarged amygdala volumes. These results combine to suggest that developmental malformation of the amygdala may underlie the social-cognitive impairments characteristic of HFA. This malformation may reflect incomplete neuronal pruning in early development.

A methodology for achieving agility in manufacturing organisations

Abstract: As we approach the twenty‐first century, manufacturing success and survival are becoming more and more difficult to ensure. This fact is rooted in the emergence of a new business era that embraces “change” as one of its major characteristics. The emphasis is now on adaptability to changes in the business environment and on addressing market and customer needs proactively. The emerging paradigm is agile manufacturing. Understanding and responding to changes, and taking advantage of changes through strategic utilisation of managerial and manufacturing methods and tools, are some of the pivotal concepts of agile manufacturing. This paper discusses these concepts and presents a methodology to assist manufacturing companies to achieve agility. Industrial questionnaire surveys and case studies are carried out to support and validate the methodology. Results and conclusions derived from the surveys and case studies in support of the methodology are reported.

Promoting professional knowledge, experiential learning and critical thinking for medical students.

Abstract: It has been recognized internationally that undergraduate medical education must adapt to changing needs, as illustrated by the Tomorrow's Doctors recommendations from the General Medical Council. This paper aims to relate contemporary educational theory to under-graduate medical educational requirements, specifically highlighting conditions (e.g. experiential learning) for: professional knowledge acquisition; critical thinking, problem-solving and clinical problem-solving; and lifelong professional learning. Furthermore, problem-based learning (PBL) is highlighted as potentially providing such conditions. There are lessons from contemporary educational theory for the reform of undergraduate medical education. These include valuing prior knowledge and experience; promoting learner responsibility through facilitating rather than directing learning; encouraging learners to test out and apply new knowledge, and using small-group work to foster explicitly the elusive skills of critical thinking and reflection. Contemporary educational theory contributes valuable insights, but cannot dictate the ultimate 'mix'; at best it provides some principles for reflective analysis of the learning experiences created for tomorrow's doctors.

Heat shock protein expression independently predicts clinical outcome in prostate cancer.

Abstract: Heat shock proteins (hsps) occupy a central role in the regulation of intracellular homeostasis, and differential expression of individual hsps occurs in a broad range of neoplastic processes. This study was performed to test the hypothesis that the particular patterns by which individual hsps become specifically modulated in human prostate cancers are correlated with behavioral phenotype and hence may be of value in determining the most appropriate clinical management of individual patients. Monoclonal antibodies specific for each hsp protein were used to assess expression of hsp27, hsp60, and hsp70 in formalin-fixed, paraffin wax-embedded, archival tissue specimens of early prostatic adenocarcinomas (pT1-2N0M0) removed at radical prostatectomy (n = 25) and in advanced cancers (n = 95) identified at transurethral resection of prostate (TURP). These findings were compared with similar data from control prostates (n = 10) removed at primary cystectomy for urinary bladder neoplasia not involving the prostate and also at TURP for benign prostatic hyperplasia (n = 50). Western blotting of whole cell lysates derived from established human prostatic epithelial cell lines PNT2, LNCaP, DU145, and PC3 was compared with expression of hsps by the primary human tissues. This study found that early in situ neoplastic transformation of normal prostatic epithelium was consistently associated with loss of hsp27 expression and that the level of hsp27 expression by individual prostate cancers was correlated with their Gleason grade. In advanced cancers, hsp27 expression was invariably associated with poor clinical outcome (P = 0.0001). Data from cell lines supported the primary tissue findings, with elevated hsp27 expression only in aggressive malignant cell lines and androgen-insensitive cell lines. Expression of hsp60 was significantly increased in both early and advanced prostate cancer when compared with nonneoplastic prostatic epithelium (P < 0.0001), as well as in malignant prostate cancer cell lines. Expression of hsp70 was unaltered in early prostate cancers when compared with nonneoplastic prostatic epithelium but showed a diminished expression in morphologically advanced cancers (P = 0.0029). No consistent correlation was found between levels of hsp60 or hsp70 expression and phenotypic behavior of individual primary prostatic cancers. Thus, patterns of hsp expression have been confirmed to be specifically and consistently modulated in both early and advanced human prostate cancers. Whereas absence of hsp27 is a reliable objective marker of early prostatic neoplasia, reexpression of this protein by an individual invasive prostatic carcinoma invariably heralds poor clinical prognosis. Because this protein has been shown to alter the balance between proliferation and apoptosis, understanding the mechanism(s) by which individual hsps regulate intracellular homeostasis may assist in explaining some key processes that occur during evolution of human prostate cancers. We suggest that hsp27 expression provides novel diagnostic and prognostic information on individual patient survival which, if obtained at the time of primary diagnosis, would assist in determining tumor-specific management strategies. Development of techniques to therapeutically modulate hsp27 expression raises the possibility of novel targeted approaches to regulate this homeostatic mechanism, thus allowing better control over tumor cell proliferation and hence patient survival.

Celecoxib Prevents Tumor Growth in Vivo without Toxicity to Normal Gut: Lack of Correlation between in Vitro and in Vivo Models

Abstract: Nonsteroidal anti-inflammatory drugs have potential for use in the prevention and/or treatment of colorectal cancer. We have studied the cytotoxic effect of a specific COX-2 inhibitor, celecoxib, against LLC, HCA-7, and HCT-15 cells grown in cell culture and have compared these results with its effect on HCA-7 cells grown as xenografts in nude mice. "High-dose" celecoxib (>20 microM) reduced the viability of all three cell lines in vitro as measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Flow cytometric analysis demonstrated that this loss of viability was attributable to the induction of apoptosis. Significantly, concentrations of the drug <10 microM had no effect on cell viability in vitro. The cytotoxic effects of high-dose celecoxib were independent of COX-2 inhibition because similar effects were observed in cox-2 (+/+), cox-2 (+/-) and cox-2 (-/-) fibroblasts. A plasma concentration of 2.3+/-0.7 microM was achieved when celecoxib (1250 mg/kg of chow) was fed to animals ad libitum. Despite a lack of toxicity at 2-3 microM celecoxib in vitro, there was attenuation of HCA-7 xenograft growth in vivo. Celecoxib had no effect on apoptosis, cell division, or the epithelial architecture of the normal gut in treated mice. These results support the need for additional clinical evaluation of celecoxib for treatment and/or prevention of colorectal cancer in humans.

Modelling dialogues using argumentation

Abstract: A number of authors have suggested the use of argumentation techniques as the basis for negotiation dialogues between agents. In this paper we augment this work by investigating the use of argumentation as the basis for a wider range of types of dialogue. The approach we take is based upon MacKenzie's dialogue game DC, and we show that a translation of this into our system of argumentation can support a subset of the types of dialogue identified by Walton and Krabbe (1995).

Calcium-dependent enzyme activation and vacuole formation in the apical granular region of pancreatic acinar cells

Abstract: The pancreatic acinar cell produces powerful digestive enzymes packaged in zymogen granules in the apical pole Ca2+ signals elicited by acetylcholine or cholecystokinin (CCK) initiate enzyme secretion by exocytosis through the apical membrane Intracellular enzyme activation is normally kept to a minimum, but in the often-fatal human disease acute pancreatitis, autodigestion occurs How the enzymes become inappropriately activated is unknown We monitored the cytosolic Ca2+ concentration ([Ca2+]i), intracellular trypsin activation, and its localization in isolated living cells with specific fluorescent probes and studied intracellular vacuole formation by electron microscopy as well as quantitative image analysis (light microscopy) A physiological CCK level (10 pM) eliciting regular Ca2+ spiking did not evoke intracellular trypsin activation or vacuole formation However, stimulation with 10 nM CCK, evoking a sustained rise in [Ca2+]i, induced pronounced trypsin activation and extensive vacuole formation, both localized in the apical pole Both processes were abolished by preventing abnormal [Ca2+]i elevation, either by preincubation with the specific Ca2+ chelator 1,2-bis(O-aminophenoxy)ethane-N,N-N′,N′-tetraacetic acid (BAPTA) or by removal of external Ca2+ CCK hyperstimulation evokes intracellular trypsin activation and vacuole formation in the apical granular pole Both of these processes are mediated by an abnormal sustained rise in [Ca2+]i

Chronic fishing disturbance has changed shelf sea benthic community structure

Abstract: Summary 1. Bottom fishing using towed nets and dredges is one of the most widespread sources of physical disturbance to the continental shelf seas throughout the world. Previous studies suggest that degradation and ecosystem changes have occurred in intensively fished areas. Nevertheless, to date it has been difficult to attribute habitat and benthic community changes to fishing effort at a spatial scale that is truly representative of commercial fishing activities. 2. In this study we present convincing evidence that chronic bottom-fishing disturbance has caused significant and widespread changes in the structure of two distinct soft-sediment benthic assemblages and habitats. 3. Our study compared the benthic fauna found in areas that have been exposed to either high or low levels of bottom-fishing disturbance over the past 10 years. We were able to validate the fishing effort data in some areas using scars in the shells of a long-lived bivalve mollusc (Glycymeris glycymeris) which result from fishing disturbance. Shell scars occurred most frequently in bivalves collected from the area of highest fishing effort. 4. Multivariate analyses and the response of abundance/biomass curves indicated that chronic fishing has caused a shift from communities dominated by relatively sessile, emergent, high biomass species to communities dominated by infaunal, smaller-bodied fauna. Removal of emergent fauna has thus degraded the topographic complexity of seabed habitats in areas of high fishing effort. The communities within these areas currently may be in an alternative stable state.

Na+, K+-ATPase isozyme diversity; comparative biochemistry and physiological implications of novel functional interactions.

Abstract: Na+, K+-ATPase is ubiquitously expressed in the plasma membrane of all animal cells where it serves as the principal regulator of intracellular ion homeostasis. Na+, K+-ATPase is responsible for generating and maintaining transmembrane ionic gradients that are of vital importance for cellular function and subservient activities such as volume regulation, pH maintenance, and generation of action potentials and secondary active transport. The diversity of Na+, K+-ATPase subunit isoforms and their complex spatial and temporal patterns of cellular expression suggest that Na+, K+-ATPase isozymes perform specialized physiological functions. Recent studies have shown that the alpha subunit isoforms possess considerably different kinetic properties and modes of regulation and the beta subunit isoforms modulate the activity, expression and plasma membrane targeting of Na+, K+-ATPase isozymes. This review focuses on recent developments in Na+, K+-ATPase research, and in particular reports of expression of isoforms in various tissues and experiments aimed at elucidating the intrinsic structural features of isoforms important for Na+, K+-ATPase function.

A modified classification for the maxillectomy defect.

Abstract: Background At present no widely accepted classification exists for the maxillectomy defect suitable for surgeons and prosthodontists. An acceptable classification that describes the defect and indicates the likely functional and aesthetic outcome is needed. Methods The classification is made on the basis of the assessment of 45 consecutive maxillectomy patients derived prospectively from the database (September 1992) and retrospectively from 1989. Results The classification of the vertical component is as follows: Class 1, maxillectomy without an oro-antral fistula; Class 2, low maxillectomy (not including orbital floor or contents); Class 3, high maxillectomy (involving orbital contents); and Class 4, radical maxillectomy (includes orbital exenteration); Classes 2 to 4 are qualified by adding the letter a, b, or c. The horizontal or palatal component is classified as follows: a, unilateral alveolar maxillectomy; b, bilateral alveolar maxillectomy; and c, total alveolar maxillary resection. Conclusion This practical classification attempts to relate the likely aesthetic and functional outcomes of a maxillectomy to the method of rehabilitation. © 2000 John Wiley & Sons, Inc. Head Neck 22: 17–26, 2000.

Ultrasound screening in pregnancy: a systematic review of the clinical effectiveness, cost-effectiveness and women's views.

Abstract: Background Advantages of early pregnancy ultrasound screening are considered to be more accurate calculation of gestational age, earlier identification of multiple pregnancies, and diagnosis of non-viable pregnancies and certain fetal malformations. Objective The objective of this review was to assess the use of routine (screening) ultrasound compared with the selective use of ultrasound in early pregnancy (i.e. before 24 weeks). Search strategy The Cochrane Pregnancy and Childbirth Group trials register and the Cochrane Controlled Trials Register (up to July 1998) were searched. Selection criteria Adequately controlled trials of routine ultrasound imaging in early pregnancy. Data collection and analysis One reviewer assessed trial quality and extracted data. Study authors were contacted for additional information. Main results Nine trials were included. The quality of the trials was generally good. Routine ultra- sound examination was associated with earlier detection of multiple pregnancies (twins undiag- nosed at 26 weeks, OR 0.08; 95% CI, 0.04 to 0.16) and reduced rates of induction of labour for post- term pregnancy (OR 0.61; 95% CI, 0.52 to 0.72). There were no differences detected for substantive clinical outcomes such as perinatal mortality (OR 0.86; 95% CI, 0.67 to 1.12). When detection of fetal abnormality was a specific aim of the exam- ination, the number of terminations of pregnancy for fetal anomaly increased. Reviewers’ conclusions Routine ultrasound in early pregnancy appears to enable better gestational age assessment, earlier detection of multiple pregnancies and earlier detection of clinically unsuspected fetal malformation at a time when termination of pregnancy is possible. However, the benefits for other substantive outcomes are less clear.

A triplet of differently shaped spin-zero states in the atomic nucleus 186Pb

Abstract: Understanding the fundamental excitations of many-fermion systems is of significant current interest. In atomic nuclei with even numbers of neutrons and protons, the low-lying excitation spectrum is generally formed by nucleon pair breaking and nuclear vibrations or rotations. However, for certain numbers of protons and neutrons, a subtle rearrangement of only a few nucleons among the orbitals at the Fermi surface can result in a different elementary mode: a macroscopic shape change. The first experimental evidence for this phenomenon came from the observation of shape coexistence in 16O (ref. 4). Other unexpected examples came with the discovery of fission isomers and super-deformed nuclei. Here we find experimentally that the lowest three states in the energy spectrum of the neutron deficient nucleus 186Pb are spherical, oblate and prolate. The states are populated by the alpha-decay of a parent nucleus; to identify them, we combine knowledge of the particular features of this decay with sensitive measurement techniques (a highly efficient velocity filters with strong background reduction, and an extremely selective recoil-alpha-electron coincidence tagging methods). The existence of this apparently unique shape triplet is permitted only by the specific conditions that are met around this particular nucleus.