Showing papers by "University of St Andrews published in 2005"
TL;DR: This review describes some recent developments in the discovery of nanoelectrolytes and nanoeLECTrodes for lithium batteries, fuel cells and supercapacitors and the advantages and disadvantages of the nanoscale in materials design for such devices.
Abstract: New materials hold the key to fundamental advances in energy conversion and storage, both of which are vital in order to meet the challenge of global warming and the finite nature of fossil fuels. Nanomaterials in particular offer unique properties or combinations of properties as electrodes and electrolytes in a range of energy devices. This review describes some recent developments in the discovery of nanoelectrolytes and nanoelectrodes for lithium batteries, fuel cells and supercapacitors. The advantages and disadvantages of the nanoscale in materials design for such devices are highlighted.
8,157 citations
TL;DR: The diverse effects of SUMO modification are discussed and models proposed to explain SUMO actions.
1,646 citations
TL;DR: In this article, the theoretical foundation of the Bessel beam is described and various experiments that make use of Bessel beams are discussed: these cover a wide range of fields including non-linear optics, where the intense central core of the bessel beam has attracted interest; short pulse non-diffracting fields; atom optics, and optical manipulation where the reconstruction properties of the beam enable new effects to be observed that cannot be seen with Gaussian beams.
Abstract: Diffraction is a cornerstone of optical physics and has implications for the design of all optical systems. The paper discusses the so-called 'non-diffracting' light field, commonly known as the Bessel beam. Approximations to such beams can be experimentally realized using a range of different means. The theoretical foundation of these beams is described and then various experiments that make use of Bessel beams are discussed: these cover a wide range of fields including non-linear optics, where the intense central core of the Bessel beam has attracted interest; short pulse non-diffracting fields; atom optics, where the narrow non-diffracting features of the Bessel beam are able to act as atomic guides and atomic confinement devices and optical manipulation, where the reconstruction properties of the beam enable new effects to be observed that cannot be seen with Gaussian beams. The intensity profile of the Bessel beam may offer routes to investigating statistical physics as well as new techniques for the...
1,173 citations
TL;DR: A comparison of the phylogeographic patterns with geological and palaeoenvironmental data demonstrates that glacial refugia were located along the southwestern, southern, eastern and northern border of the Alps, which implies that evolutionary or biogeographic processes induced by climatic fluctuations act on gene and species diversity in a similar way.
Abstract: Many mountain ranges have been strongly glaciated during the Quaternary ice ages, and the locations of glacial refugia of mountain plants have been debated for a long time. A series of detailed molecular studies, investigating intraspecific genetic variation of mountain plants in the European Alps, now allows for a first synopsis. A comparison of the phylogeographic patterns with geological and palaeoenvironmental data demonstrates that glacial refugia were located along the southwestern, southern, eastern and northern border of the Alps. Additional glacial refugia were present in central Alpine areas, where high-elevation plants survived the last glaciation on ice-free mountain tops. The observed intraspecific phylogeographies suggest general patterns of glacial survival, which conform to well-known centres of Alpine species diversity and endemism. This implies that evolutionary or biogeographic processes induced by climatic fluctuations act on gene and species diversity in a similar way.
803 citations
801 citations
TL;DR: It is suggested that the difference in performance of chimpanzees and children may be due to a greater susceptibility of children to cultural conventions, perhaps combined with a differential focus on the results, actions and goals of the demonstrator.
Abstract: This study explored whether the tendency of chimpanzees and children to use emulation or imitation to solve a tool-using task was a response to the availability of causal information. Young wild-born chimpanzees from an African sanctuary and 3- to 4-year-old children observed a human demonstrator use a tool to retrieve a reward from a puzzle-box. The demonstration involved both causally relevant and irrelevant actions, and the box was presented in each of two conditions: opaque and clear. In the opaque condition, causal information about the effect of the tool inside the box was not available, and hence it was impossible to differentiate between the relevant and irrelevant parts of the demonstration. However, in the clear condition causal information was available, and subjects could potentially determine which actions were necessary. When chimpanzees were presented with the opaque box, they reproduced both the relevant and irrelevant actions, thus imitating the overall structure of the task. When the box was presented in the clear condition they instead ignored the irrelevant actions in favour of a more efficient, emulative technique. These results suggest that emulation is the favoured strategy of chimpanzees when sufficient causal information is available. However, if such information is not available, chimpanzees are prone to employ a more comprehensive copy of an observed action. In contrast to the chimpanzees, children employed imitation to solve the task in both conditions, at the expense of efficiency. We suggest that the difference in performance of chimpanzees and children may be due to a greater susceptibility of children to cultural conventions, perhaps combined with a differential focus on the results, actions and goals of the demonstrator
774 citations
TL;DR: It is shown that experimentally introduced technologies will spread within different ape communities, and a subset of chimpanzees that discovered the alternative method nevertheless went on to match the predominant approach of their companions, showing a conformity bias that is regarded as a hallmark of human culture.
Abstract: Humans are not alone in wanting to fit in: chimpanzees also conform to the cultural norm. It is well known that chimpanzees sustain different local traditions of tool-use, but a new study shows that they conform to the group norms in an unexpectedly human-like way. By training one individual in each of two groups to use a tool to extract hidden food in different ways, various technologies were ‘seeded’ into social groups. These developed into stable subcultures during the two-month study. Some individuals stumbled on the alternative method, yet converged on the local group norm. Human conformity to local custom may have a much more ancient evolutionary ancestry than was assumed. Rich circumstantial evidence suggests that the extensive behavioural diversity recorded in wild great apes reflects a complexity of cultural variation unmatched by species other than our own1,2,3,4,5,6,7,8,9,10,11,12. However, the capacity for cultural transmission assumed by this interpretation has remained difficult to test rigorously in the field, where the scope for controlled experimentation is limited13,14,15,16. Here we show that experimentally introduced technologies will spread within different ape communities. Unobserved by group mates, we first trained a high-ranking female from each of two groups of captive chimpanzees to adopt one of two different tool-use techniques for obtaining food from the same ‘Pan-pipe’ apparatus, then re-introduced each female to her respective group. All but two of 32 chimpanzees mastered the new technique under the influence of their local expert, whereas none did so in a third population lacking an expert. Most chimpanzees adopted the method seeded in their group, and these traditions continued to diverge over time. A subset of chimpanzees that discovered the alternative method nevertheless went on to match the predominant approach of their companions, showing a conformity bias that is regarded as a hallmark of human culture11.
617 citations
TL;DR: A systematic review of studies of decision-making by health care managers and policy-makers and the websites of research funders, producers/purveyors of research, and journals that include them among their target audiences found that contextual factors were rarely highlighted, recommendations were often provided and graded entry formats were rarely used.
Abstract: Objectives: To identify ways to improve the usefulness of systematic reviews for health care managers and policy-makers that could then be evaluated prospectively. Methods: We systematically reviewed studies of decision-making by health care managers and policy-makers, conducted interviews with a purposive sample of them in Canada and the United Kingdom (n ¼ 29), and reviewed the websites of research funders, producers/purveyors of research, and journals that include them among their target audiences (n ¼ 45). Results: Our systematic review identi¢ed that factors such as interactions between researchers and health care policy-makers and timing/timeliness appear to increase the prospects for research use among policymakers. Our interviews with health care managers and policy-makers suggest that they would bene¢t from having information that is relevant for decisions highlighted for them (e.g. contextual factors that aiect a review’s local applicability and information about the bene¢ts, harms/risks and costs of interventions) and having reviews presented in a way that allows for rapid scanning for relevance and then graded entry (such as one page of take-home messages, a three-page executive summary and a 25-page report). Managers and policy-makers have mixed views about the helpfulness of recommendations. Our analysis of websites found that contextual factors were rarely highlighted, recommendations were often provided and graded entry formats were rarely used. Conclusions: Researchers could help to ensure that the future £ow of systematic reviews will better inform health care management and policy-making by involving health care managers and policy-makers in their production and better highlighting information that is relevant for decisions. Research funders could help to ensure that the global stock of systematic reviews will better inform health care management and policymaking by supporting and evaluating local adaptation processes such as developing and making available online more user-friendly ‘front ends’ for potentially relevant systematic reviews.
594 citations
TL;DR: In this paper, case studies of public attitudes towards existing and proposed windfarm developments in Scotland and Ireland are used to test three counter-intuitive hypotheses derived from previous attitudinal research, namely, local people become more favourable towards windfarms after construction, the degree of acceptance increases with proximity to them, and the NIMBY syndrome does not adequately explain variations in public attitudes.
Abstract: The wind energy debate represents a new kind of environmental controversy which divides environmentalists of different persuasions who attach contrasting priority to global and local concerns. Case studies of public attitudes towards existing and proposed windfarm developments in Scotland and Ireland are used to test three counter-intuitive hypotheses derived from previous attitudinal research. These are: (a) that local people become more favourable towards windfarms after construction; (b) that the degree of acceptance increases with proximity to them; and (c) that the NIMBY syndrome(not-in-my-back-yard) does not adequately explain variations in public attitudes. All three hypotheses are supported by this study. Large majorities favour wind power development in principle and in (local) practice. Although some aspects of NIMBY attitudes exist, the surveys reveal an ‘inverse NIMBY’ syndrome, whereby those with windfarms in their ‘backyard’ strongly support the technology. The research endorses the...
576 citations
TL;DR: Although the precise mechanism of action of VNS is still unknown, the search for the mechanism has the potential to lend new insight into the neuropathology of depression, a review of the pre-clinical and clinical literature relating to VNS concludes.
568 citations
TL;DR: It is concluded that progress in understanding the evolution of language will require much more empirical research, grounded in modern comparative biology, more interdisciplinary collaboration, and much less of the adaptive storytelling and phylogenetic speculation that has traditionally characterized the field.
TL;DR: In this paper, the authors argue that leadership is a vehicle for social identity-based collective agency in which leaders and followers are partners, and explore the two sides of this partnership: the way in which a shared sense of identity makes leadership possible, and the way leaders act as entrepreneurs of identity in order to make particular forms of identity and their own leadership viable.
Abstract: Traditional models see leadership as a form of zero-sum game in which leader agency is achieved at the expense of follower agency and vice versa. Against this view, the present article argues that leadership is a vehicle for social identity-based collective agency in which leaders and followers are partners. Drawing upon evidence from a range of historical sources and from the BBC Prison Study, the present article explores the two sides of this partnership: the way in which a shared sense of identity makes leadership possible and the way in which leaders act as entrepreneurs of identity in order to make particular forms of identity and their own leadership viable. The analysis also focuses (a) on the way in which leaders' identity projects are constrained by social reality, and (b) on the manner in which effective leadership contributes to the transformation of this reality through the initiation of structure that mobilizes and redirects a group's identity-based social power.
TL;DR: The huge trapping times without the use of a cavity reveal new perspectives for dispersion and time control within photonic crystals.
Abstract: We show the real-space observation of fast and slow pulses propagating inside a photonic crystal waveguide by time-resolved near-field scanning optical microscopy. Local phase and group velocities of modes are measured. For a specific optical frequency we observe a localized pattern associated with a flat band in the dispersion diagram. During at least 3 ps, movement of this field is hardly discernible: its group velocity would be at most c/1000. The huge trapping times without the use of a cavity reveal new perspectives for dispersion and time control within photonic crystals.
TL;DR: In this article, the authors show direct observational evidence that illuminates the energetic micrometre-scale interactions between individual cells and violently cavitating shelled microbubbles, and suggest that sonoporation at higher intensities may arise through a synergistic interplay involving several distinct processes.
Abstract: In fluids, pressure-driven cavitation bubbles have a nonlinear response that can lead to extremely high core-energy densities during the collapse phase—a process underpinning phenomena such as sonoluminescence1 and plasma formation2. If cavitation occurs near a rigid surface, the bubbles tend to collapse asymmetrically, often forming fast-moving liquid jets that may create localized surface damage3. As encapsulated microbubbles are commonly used to improve echo generation in diagnostic ultrasound imaging, it is possible that such cavitation could also lead to jet-induced tissue damage. Certainly ultrasonic irradiation (insonation) of cells in the presence of microbubbles can lead to enhanced membrane permeabilization and molecular uptake (sonoporation)4,5,6,7, but, although the mechanism during low-intensity insonation is clear8, experimental corroboration for higher pressure regimes has remained elusive. Here we show direct observational evidence that illuminates the energetic micrometre-scale interactions between individual cells and violently cavitating shelled microbubbles. Our data suggest that sonoporation at higher intensities may arise through a synergistic interplay involving several distinct processes.
TL;DR: This model is reported the first model to reliably predict the age of ovarian failure after treatment with a known dose of radiotherapy, and will enable physicians to counsel women on their reproductive potential following successful treatment.
Abstract: Purpose: To predict the age at which ovarian failure is likely to develop after radiation to a field that includes the ovary in women treated for cancer. Methods and Materials: Modern computed tomography radiotherapy planning allows determination of the effective dose of radiation received by the ovaries. Together with our recent assessment of the radiosensitivity of the human oocyte, the effective surviving fraction of primordial oocytes can be determined and the age of ovarian failure, with 95% confidence limits, predicted for any given dose of radiotherapy. Results: The effective sterilizing dose (ESD: dose of fractionated radiotherapy [Gy] at which premature ovarian failure occurs immediately after treatment in 97.5% of patients) decreases with increasing age at treatment. ESD at birth is 20.3 Gy; at 10 years 18.4 Gy, at 20 years 16.5 Gy, and at 30 years 14.3 Gy. We have calculated 95% confidence limits for age at premature ovarian failure for estimated radiation doses to the ovary from 1 Gy to the ESD from birth to 50 years. Conclusions: We report the first model to reliably predict the age of ovarian failure after treatment with a known dose of radiotherapy. Clinical application of this model will enable physicians to counsel women on their reproductive potential following successful treatment.
TL;DR: A range of evidence from geomorphology, palynology, biogeography and vegetation/climate modelling suggests that a north-south "savanna corridor" did exist through the continent of Sundaland through the Last Glacial Period (LGP) at times of lowered sea-level, as originally proposed by Heaney [1991] as discussed by the authors.
TL;DR: The habitat components determining the structure of bee communities are well known when considering foraging resources; however, there is little data with respect to the role of nesting resources.
Abstract: 1. The habitat components determining the structure of bee communities are well known when considering foraging resources; however, there is little data with respect to the role of nesting resources. 2. As a model system this study uses 21 diverse bee communities in a Mediterranean landscape comprising a variety of habitats regenerating after fire. The findings clearly demonstrate that a variety of nesting substrates and nest building materials have key roles in organising the composition of bee communities. 3. The availability of bare ground and potential nesting cavities were the two primary factors influencing the structure of the entire bee community, the composition of guilds, and also the relative abundance of the dominant species. Other nesting resources shown to be important include availability of steep and sloping ground, abundance of plant species providing pithy stems, and the occurrence of pre-existing burrows. 4. Nesting resource availability and guild structure varied markedly across habitats in different stages of post-fire regeneration; however, in all cases, nest sites and nesting resources were important determinants of bee community structure.
TL;DR: Preliminary evidence suggests that early intervention with the patient and their carer could prevent later development of psychological distress in both members.
TL;DR: In this article, the determinants of profitability for manufacturing and service sector firms in Belgium, France, Italy and the UK, for the period 1993-2001, were investigated using panel data econometrics.
Abstract: Recent advances in panel data econometrics are used to investigate the determinants of profitability for manufacturing and service sector firms in Belgium, France, Italy and the UK, for the period 1993–2001. The paper synthesizes empirical models that have been used by researchers in industrial economics, strategic management and accounting and finance. Despite the formation of the European Union's Single Market in goods and services, abnormal profit still appears to persist significantly from year to year. There is evidence of a negative size-profitability relationship, but the relationship between market share and profitability is positive, and stronger in manufacturing than in services. The relationship between a firm's gearing ratio and its profitability is negative, but firms with higher liquidity tend to be more profitable.
TL;DR: Doping strategies can enhance the conductivity of crystalline polymer electrolytes in a manner somewhat analogous to the AgBr1-x I x ionic conductors, a significant advance towards the technological exploitation of such materials.
Abstract: Polymer electrolytes consist of salts dissolved in polymers (for example, polyethylene oxide, PEO), and represent a unique class of solid coordination compounds. They have potential applications in a diverse range of all-solid-state devices, such as rechargeable lithium batteries, flexible electrochromic displays and smart windows1,2,3,4,5. For 30 years, attention was focused on amorphous polymer electrolytes in the belief that crystalline polymer:salt complexes were insulators. This view has been overturned recently by demonstrating ionic conductivity in the crystalline complexes PEO6:LiXF6 (X = P, As, Sb); however, the conductivities were relatively low6,7. Here we demonstrate an increase of 1.5 orders of magnitude in the conductivity of these materials by replacing a small proportion of the XF6- anions in the crystal structure with isovalent N(SO2CF3)2- ions. We suggest that the larger and more irregularly shaped anions disrupt the potential around the Li+ ions, thus enhancing the ionic conductivity in a manner somewhat analogous to the AgBr1-xIx ionic conductors8. The demonstration that doping strategies can enhance the conductivity of crystalline polymer electrolytes represents a significant advance towards the technological exploitation of such materials.
TL;DR: The studies on enzymes immobilized on ordered mesoporous solids and the need for careful studies in real applications are reviewed and the emerging applications of related biomolecule–mesoporous solid hybrids in other applications are noted.
Abstract: The discovery in the late 1990s of ordered, high surface area silicas with pore sizes of 5 nm and above opened the way to the study of well-defined biomolecule–mesoporous silica hybrids. In particular, it has been possible to immobilize a range of small to medium size enzymes, such as proteases, lipases and peroxidases, via physisorption, encapsulation and tethering on the internal surfaces of the solids. Use has also been made of silicas functionalized for this purpose. In many cases the immobilized enzymes are both active and re-usable. Here we review the studies on enzymes immobilized on ordered mesoporous solids and assess the need for careful studies in real applications. Furthermore, we note the emerging applications of related biomolecule–mesoporous solid hybrids in other applications, such as intracellular drug delivery and transfection technology.
TL;DR: In this paper, the performance of 60 European funds from four countries was evaluated using the UK matched pair approach for fund evaluation developed by Mallin et al. (1995) to a European setting and found that there is no difference between ethical and non-ethical funds according to the performance measures employed.
Abstract: This paper studies the performance of 60 European funds from four countries. The paper extends the UK matched pair approach for fund evaluation developed by Mallin et al. (1995) to a European setting. The findings suggest that there is no difference between ethical and non-ethical funds according to the performance measures employed. Neither type of fund displayed any ability to time the market. Finally, the results indicate that the management fee is a significant explanatory variable for the Jensen measure as Chen et al. (1992) and Grinblatt and Titman (1994) suggested.
TL;DR: In this paper, an ethnographic study of two crowd events was carried out in order to develop a hypothesis about the experience of empowerment in collective action, which suggests that empowerment as an outcome of collective action is a function of the extent to which one can be empowered.
Abstract: An ethnographic study of two crowd events was carried out in order to develop a hypothesis about the experience of empowerment in collective action. Qualitative comparison of an anti-roads occupation and a mass eviction suggests that empowerment as an outcome of collective action is a function of the extent to which oneb
TL;DR: It is concluded that no single index can capture all aspects of biodiversity change, but that a modified Shannon index and the geometric mean of relative abundance have useful properties.
Abstract: The need to monitor trends in biodiversity raises many technical issues. What are the features of a good biodiversity index? How should trends in abundance of individual species be estimated? How should composite indices, possibly spanning very diverse taxa, be formed? At what spatial scale should composite indices be applied? How might change-points—points at which the underlying trend changes—be identified? We address some of the technical issues underlying composite indices, including survey design, weighting of the constituent indices, identification of change-points and estimation of spatially varying time trends. We suggest some criteria that biodiversity measures for use in monitoring surveys should satisfy, and we discuss the problems of implementing rigorous methods. We illustrate the properties of different composite indices using UK farmland bird data. We conclude that no single index can capture all aspects of biodiversity change, but that a modified Shannon index and the geometric mean of relative abundance have useful properties.
TL;DR: This review draws attention to the problem that fitness consequences of antipredation behaviors cannot be determined without considering the potential for reduction of predation risk, or increased reproductive output, through other compensatory behaviors than the behaviors under study.
Abstract: Any animal whose form or behavior facilitates the avoidance of predators or escape when attacked by predators will have a greater probability of surviving to breed and therefore greater probability ...
TL;DR: In this article, the authors manipulated the fundamental frequencies and apparent vocal tract lengths of young adult male voices, both independently and simultaneously, and assessed their impact on female ratings of masculinity, size, age and attractiveness.
TL;DR: In this article, the authors investigate the dependence of stellar properties on the mean thermal Jeans mass in molecular clouds and compare the results from the two largest hydrodynamical simulations of star formation to resolve the fragmentation process down to the opacity limit.
Abstract: We investigate the dependence of stellar properties on the mean thermal Jeans mass in molecular clouds. We compare the results from the two largest hydrodynamical simulations of star formation to resolve the fragmentation process down to the opacity limit, the first of which was reported by Bate, Bonnell & Bromm. The initial conditions of the two calculations are identical except for the radii of the clouds, which are chosen so that the mean densities and mean thermal Jeans masses of the clouds differ by factors of 9 and 3, respectively. We find that the denser cloud, with the lower mean thermal Jeans mass, produces a higher proportion of brown dwarfs and has a lower characteristic (median) mass of the stars and brown dwarfs. This dependence of the initial mass function (IMF) on the density of the cloud may explain the observation that the Taurus star-forming region appears to be deficient in brown dwarfs when compared with the Orion Trapezium cluster. The new calculation also produces wide binaries (separations >20 au), one of which is a wide binary brown dwarf system. Based on the hydrodynamical calculations, we develop a simple accretion/ejection model for the origin of the IMF. In the model, all stars and brown dwarfs begin with the same mass (set by the opacity limit for fragmentation) and grow in mass until their accretion is terminated stochastically by their ejection from the cloud through dynamically interactions. The model predicts that the main variation of the IMF in different star-forming environments should be in the location of the peak (due to variations in the mean thermal Jeans mass of the cloud) and in the substellar regime. However, the slope of the IMF at high masses may depend on the dispersion in the accretion rates of protostars. Ke yw ords: accretion, accretion discs ‐ hydrodynamics ‐ binaries: general ‐ stars: formation ‐ stars: low-mass, brown dwarfs ‐ stars: luminosity function, mass function.
TL;DR: Men show an overall worse performance compared to women on a task measuring the processing of emotional faces, and are less accurate, as well as less sensitive in labelling facial expressions.
Abstract: There is evidence that men and women display differences in both cognitive and affective functions. Recent studies have examined the processing of emotions in males and females. However, the findings are inconclusive, possibly the result of methodological differences. The aim of this study was to investigate the perception of emotional facial expressions in men and women. Video clips of neutral faces, gradually morphing into full-blown expressions were used. By doing this, we were able to examine both the accuracy and the sensitivity in labelling emotional facial expressions. Furthermore, all participants completed an anxiety and a depression rating scale. Research participants were 40 female students and 28 male students. Results revealed that men were less accurate, as well as less sensitive in labelling facial expressions. Thus, men show an overall worse performance compared to women on a task measuring the processing of emotional faces. This result is discussed in relation to recent findings.
TL;DR: The p300 protein serves as a rate-limiting transcriptional cointegrator of diverse transcription factors either to activate or to repress transcription through modular subdomains and may serve an important integration point during metabolism and cellular differentiation.
TL;DR: Results suggest that neurons in the STS form multisensory representations of observed actions, and this work investigates whether STS neurons coding the sight of actions also integrated the sound of those actions.
Abstract: Processing of complex visual stimuli comprising facial movements, hand actions, and body movements is known to occur in the superior temporal sulcus (STS) of humans and nonhuman primates. The STS is also thought to play a role in the integration of multimodal sensory input. We investigated whether STS neurons coding the sight of actions also integrated the sound of those actions. For 23% of neurons responsive to the sight of an action, the sound of that action significantly modulated the visual response. The sound of the action increased or decreased the visually evoked response for an equal number of neurons. In the neurons whose visual response was increased by the addition of sound (but not those neurons whose responses were decreased), the audiovisual integration was dependent upon the sound of the action matching the sight of the action. These results suggest that neurons in the STS form multisensory representations of observed actions.