bluuebunny/crossref_metadata_2025 huggingface dataset:
Roll waves in a non-regular inclined channel
Authors: BOUDLAL A. , LIAPIDEVSKII V. YU.
Published: October 2004

For nonlinear hyperbolic equations of a gas dynamic type with flow acceleration and friction terms, the classification of a special class of periodic travelling waves, which are known as roll waves, is given. As an illustration, the shallow water equations for the inclined channels of an arbitrary cross-section are considered. The analysis shows that the flow patterns depend upon the sign of the second derivative of the pressure function. The roll waves in regular channels with the convex pressure have the same structure as the waves described in Dressler [6]. For a nonconvex pressure function, the multi-jump configuration of roll waves is found.
A linear-elastic model of anisotropic tumour growth
Authors: ARAUJO R. P. , McELWAIN D. L. S.
Published: October 2004

This paper examines the effect of anisotropic growth on the evolution of mechanical stresses in a linear-elastic model of a growing, avascular tumour. This represents an important improvement on previous linear-elastic models of tissue growth since it has been shown recently that spatially-varying isotropic growth of linear-elastic tissues does not afford the necessary stress-relaxation for a steady-state stress distribution upon reaching a nutrient-regulated equilibrium size. Time-dependent numerical solutions are developed using a Lax-Wendroff scheme, which show the evolution of the tissue stress distributions over a period of growth until a steady-state is reached. These results are compared with the steady-state solutions predicted by the model equations, and key parameters influencing these steady-state distributions are identified. Recommendations for further extensions and applications of this model are proposed.
The self-similar solution for draining in the thin film equation
Authors: VAN DEN BERG JAN BOUWE , BOWEN MARK , KING JOHN R. , EL-SHEIKH M. M. A.
Published: October 2004

We investigate self-similar solutions of the thin film equation in the case of zero contact angle boundary conditions on a finite domain. We prove existence and uniqueness of such a solution and determine the asymptotic behaviour as the exponent in the equation approaches the critical value at which zero contact angle boundary conditions become untenable. Numerical and power-series solutions are also presented.
Global variables in Haskell
Authors: HUGHES JOHN
Published: October 2004

Haskell today provides good support not only for a functional programming style, but also for an imperative one. Elements of imperative programming are needed in applications such as web servers, or to provide efficient implementations of well-known algorithms, such as many graph algorithms. However, one element of imperative programming, the global variable, is surprisingly hard to emulate in Haskell. We discuss several existing methods, none of which is really satisfactory, and finally propose a new approach based on implicit parameters. This approach is simple, safe, and efficient, although it does reveal weaknesses in Haskell's present type system.
Enumerating the strings of regular languages
Authors: McILROY M. DOUGLAS
Published: October 2004

Haskell code is developed for two ways to list the strings of the language defined by a regular expression: directly by set operations and indirectly by converting to and simulating an equivalent automaton. The exercise illustrates techniques for dealing with infinite ordered domains and leads to an effective standard form for nondeterministic finite automata.
Low genetic diversity in the Endangered Crested Ibis Nipponia nippon and implications for conservation
Authors: ZHANG BEI , FANG SHENG-GUO , XI YONG-MEI
Published: October 2004

Crested Ibis Nipponia nippon is an Endangered species that has experienced a severe but short-lived population bottleneck in recent years. Only one wild population and two captive populations exist in China today, all of which were probably initiated from two breeding pairs rediscovered in 1981. This paper represents the first study of the genetic diversity of Crested Ibis by analysing sequence variation of a fragment spanning domains II and III of the mitochondrial DNA (mtDNA) control region of both wild and captive populations. Two haplotypes were identified in both wild and captive populations, and the captive population had a bias towards haplotype 1. The species as a whole demonstrated an extremely low level of genetic diversity, with a haplotype diversity and nucleotide diversity of 0.386 ± 0.074 and 0.069% ± 0.013%, respectively. Despite the rapid increase in numbers of birds under intensive management, the paucity of genetic diversity remains a real threat to the species. The mtDNA control region variations detected in the present study could provide significant information additional to the studbook data of Crested Ibis; therefore we suggest that special attention be paid to individuals with haplotype 2 when considering captive breeding management. Overall, great care should be taken in the selection of reintroduction sites for this rare bird, as species with low genetic diversity are thought to be more limited in their ability to tolerate a wide range of environmental extremes and diseases.
Proof systems for lattice theory
Authors: NEGRI SARA , VON PLATO JAN
Published: October 2004

A formulation of lattice theory as a system of rules added to sequent calculus is given. The analysis of proofs for the contraction-free calculus of classical predicate logic known as G3c extends to derivations with the mathematical rules of lattice theory. It is shown that minimal derivations of quantifier-free sequents enjoy a subterm property: all terms in such derivations are terms in the endsequent.

An alternative formulation of lattice theory as a system of rules in natural deduction style is given, both with explicit meet and join constructions and as a relational theory with existence axioms. A subterm property for the latter extends the standard decidable classes of quantificational formulas of pure predicate calculus to lattice theory.
Towards a quantum programming language
Authors: SELINGER PETER
Published: October 2004

We propose the design of a programming language for quantum computing. Traditionally, quantum algorithms are frequently expressed at the hardware level, for instance in terms of the quantum circuit model or quantum Turing machines. These approaches do not encourage structured programming or abstractions such as data types. In this paper, we describe the syntax and semantics of a simple quantum programming language with high-level features such as loops, recursive procedures, and structured data types. The language is functional in nature, statically typed, free of run-time errors, and has an interesting denotational semantics in terms of complete partial orders of superoperators.
A domain equation for refinement of partial systems
Authors: HUTH MICHAEL R. A. , JAGADEESAN RADHA , SCHMIDT DAVID A.
Published: October 2004

A reactive system can be specified by a labelled transition system, which indicates static structure, along with temporal-logic formulas, which assert dynamic behaviour. But refining the former while preserving the latter can be difficult, because:

(i) Labelled transition systems are ‘total’ – characterised up to bisimulation – meaning that no new transition structure can appear in a refinement.

(ii) Alternatively, a refinement criterion not based on bisimulation might generate a refined transition system that violates the temporal properties.

In response, Larsen and Thomson proposed modal transition systems, which are ‘partial’, and defined a refinement criterion that preserved formulas in Hennessy–Milner logic. We show that modal transition systems are, up to a saturation condition, exactly the mixed transition systems of Dams that meet a mix condition, and we extend such systems to non-flat state sets. We then solve a domain equation over the mixed powerdomain whose solution is a bifinite domain that is universal for all saturated modal transition systems and is itself fully abstract when considered as a modal transition system. We demonstrate that many frameworks of partial systems can be translated into the domain: partial Kripke structures, partial bisimulation structures, Kripke modal transition systems, and pointer-shape-analysis graphs.
Operational aspects of untyped Normalisation by Evaluation
Authors: AEHLIG KLAUS , JOACHIMSKI FELIX
Published: October 2004

A purely syntactic and untyped variant of Normalisation by Evaluation for the $\lambda$-calculus is presented in the framework of a two-level $\lambda$-calculus with rewrite rules to model the inverse of the evaluation functional. Among its operational properties there is a standardisation theorem that formally establishes the adequacy of implementation in functional programming languages. An example implementation in Haskell is provided. The relation to the usual type-directed Normalisation by Evaluation is highlighted, using a short analysis of $\eta$-expansion that leads to a perspicuous strong normalisation and confluence proof for $\beta\eta\!\up$-reduction as a byproduct.
Royal Photographs: Emotions for the People
Authors: SCHWARZENBACH ALEXIS
Published: October 2004

Although almost all of Europe was under royal rule for most of the nineteenth and much of the twentieth century, very little effort has so far been dedicated to explaining this phenomenon. By examining royal photographs the author is able to shed light on some of the central mechanisms leading to this remarkable royal success. By analysing the production, distribution and perception of royal photographs in a variety of European countries, this article shows that these images were a crucial means by which royal families were turned into powerful symbols of modern nations. Regularly made by the most renowned portrait photographers and widely distributed via the press and as postcards and personal commemorative gifts, royal photographs allowed monarchies to acquire an absolutely vital asset for their survival at the head of modern European societies, namely strong emotional bonds between individual members of the general public and royal families.
Defining the Profession of Architect in the Twentieth Century: France, Italy and the United States
Authors: SCRIVANO PAOLO
Published: October 2004

Anthony Alofsin, The Struggle for Modernism. Architecture, Landscape Architecture, and City Planning at Harvard (New York and London: W.W. Norton & Company, 2002), 311 pp., $60.00 (hb), ISBN 0–393–730484.

Hélène Jannière, Politiques éditoriales et architecture ‘moderne’. L'émergence de nouvelles revues en France et en Italie (1923–1939) (Paris: Éditions Arguments, 2002), 377 pp., €24.50 (pb), ISBN 2–909109–26–7.

Paolo Nicoloso, Gli architetti di Mussolini. Scuole e sindacato, architetti e massoni, professori e politici negli anni del regime (Milan: FrancoAngeli, 1999), 239 pp., €19.63 (pb), ISBN 88–464–1305–9.
A statistical method for forecasting extreme daily temperatures using ECMWF 2‐m temperatures and ground station measurements
Authors: Boi P.
Published: October 2004

A recursive statistical method is given to post‐process the 2‐metre temperature ECMWF General Circulation Model by using the SAR network of surface stations in Sardinia. The method calculates daily maximum and minimum temperature forecasts up to 5 days ahead for 55 stations. Forecasts over one year for 55 ground stations have been analysed. A comparison with Direct Model Output (DMO) and persistence is then made, giving special attention to the winter season and to freezing conditions. The error analysis shows a BIAS very close to zero (between 0°C and 0.5°C) on all the stations and a marked reduction of mean absolute error compared to the DMO forecast. The error reduction is more marked in the case of freezing conditions than with the DMO forecast. Such situations are difficult to forecast and the very high BIAS of DMO has not been eliminated completely. The advantages of the procedure are: (a) there is no need to store large numbers of measurements and large amounts of model forecast data; (b) the estimated correction is easily adapted to new meteorological conditions; (c) the procedure is transparent to the updating of the model; and (d) the procedure is very easy to implement operationally. Copyright © 2004 Royal Meteorological Society
Modelling local winds over the Salento peninsula
Authors: Mangia Cristina , Martano Paolo , Miglietta Mario Marcello , Morabito Angela , Tanzarella Annalisa
Published: October 2004

A three‐day mesoscale numerical simulation has been performed over the narrow Salento peninsula (south‐eastern Italy) during summer conditions characterised by weak synoptic forcing. These atmospheric conditions favour the development of complex sea‐breeze systems and convergence zones on the peninsula. The aim of this work is to investigate the ability of an atmospheric mesoscale model to reproduce the surface fields of meteorological variables in the presence of local‐scale forcing and breeze circulations, which are fundamental in applications such as air pollution modelling and nowcasting.

The modelled fields have been compared with available surface measurements and sodar data. Results indicate that the model can simulate the general mean wind field in a realistic way. The diurnal evolution of the wind is well reproduced and the maximum deviations mostly occur during the night, being associated with calm conditions.

Statistical analysis indicates that the typical mean bias is found to be about 1 m s−1 for hourly averaged wind speed, less than 20° for wind direction and about 1°C for temperature. The root mean square error (rmse) varies from 1 to 3 m s−1 for wind speed, from 50° to 70° for wind direction, and is about 2.4°C for temperature. All the values of the numerical indexes are within ranges which are characteristic of those found for other state‐of‐the‐art models applied to similar cases studies.

Despite a good overall agreement between predictions and observations, some discrepancies were found in the individual profiles due both to the limited spatial representation of the local details and to the complex wind field which makes the space–time matching between the model and the observations quite critical.

The structures of the thermal mixed layer and the breeze convergence zone are similar to numerical studies relative to more idealised conditions. Copyright © 2004 Royal Meteorological Society
Applications of radar‐based nowcasting techniques for mesoscale weather forecasting in Hong Kong
Authors: Li P. W. , Lai Edwin S. T.
Published: October 2004

Operational forecasting of mesoscale weather systems in Hong Kong is supported by an automated nowcasting system called SWIRLS (Short‐range Warning of Intense Rainstorms in Localised Systems). SWIRLS is based on the extrapolation of radar echoes using the TREC (Tracking Radar Echoes by Correlation) technique. With a suitable choice of pixel array size on the radar reflectivity maps, the TREC vectors derived can be used to monitor and extrapolate echo motion right across the mesoscale spectrum, from individual convective cells, to supercells and clusters, and to groups of rainbands or squall lines.

On the basis of TREC, quantitative precipitation forecast (QPF) algorithms have been developed to produce high resolution forecast rainfall distribution maps over the local area. These maps provide useful objective guidance for forecasters to assess the likely rain scenario in the next few hours and to facilitate decision‐making in operating the Rainstorm Warning System. This review, however, will focus on other aspects of TREC applications and some side benefits for operational mesoscale forecasting in Hong Kong. First, extension of the TREC technique to group tracking of echoes (GTrack) have enabled forecasters to make qualitative educated guesses of the likelihood of prolonged heavy rain or the potential of enhanced storm development. Secondly, extension of the QPF algorithms to a forecast range of 3 hours, supplemented by real‐time accumulated rainfall data from a high density raingauge network, has enabled forecasters to provide reliable advice and guidance to geotechnical engineers for landslip risk assessment. Thirdly, rain‐related applications aside, TREC vectors are also ingested into a data analysis system LAPS (Local Analysis and Prediction System) adapted from Forecast Systems Laboratory (FSL) of NOAA. Through the assimilation of TREC vectors and other wind observations, a three‐dimensional wind structure of tropical cyclones can be generated in near real‐time for forecasters' reference in assessing landfall impact. Copyright © 2004 Royal Meteorological Society
Pollutant transport schemes integrated in a numerical weather prediction model: model description and verification results
Authors: Chenevez Jérôme , Baklanov Alexander , Havskov Sørensen Jens
Published: October 2004

Regional air pollution models are usually off‐line coupled with numerical weather prediction models. The present study, however, focuses on on‐line coupled modelling, for which the air pollution model is an integral part of the meteorological model. To this purpose, simulations of the first European Tracer Experiment (ETEX), which supplies the best suited verification data for dispersion modelling of a passive tracer, have been performed using versions of the Danish Meteorological Institute High Resolution Limited‐Area Model (DMI‐HIRLAM). Simulation results have been compared with observed values as well as with results from other models.

The operational version of DMI‐HIRLAM using well‐known basic advection schemes has been tested, showing the need for improvements for air pollution purposes. The fourth‐order Bott algorithm for advection has thus been implemented in the semi‐Lagrangian version of DMI‐HIRLAM. Due to its practically perfect mass conservation properties and its low computational cost, this method turns out to be efficient for simulations of transport of pollutants in the atmosphere. This represents a first effort towards a fully integrated air pollution model, e.g. for forecasting purposes. Copyright © 2004 Royal Meteorological Society
Development strategy and trade liberalization: implications for poverty and environment in the Philippines
Authors: COXHEAD IAN , JAYASURIYA SISIRA
Published: October 2004

Poverty and environmental degradation or deforestation in developing countries have common determinants in underlying economic and institutional conditions that determine factor and product prices and incentives for migration and resource-depleting activities. These determinants include property rights failures (open access to forest lands) but also ‘government failures’ in the form of policies that indirectly promote resource use and retard poverty alleviation. A general equilibrium analysis identifies influences that such distortions have on poverty and environment. Using a numerical GE model, we consider likely effects of Philippine trade policy reforms of the 1990s on determinants of poverty, deforestation, and agricultural land expansion. These reforms marked a significant shift away from the import substitution industrialization strategy that characterized post-independence Philippine development. The results suggest that though reforms would increase poverty in the short term, in the longer run trade liberalization is poverty reducing. The environmental impact can also be positive, provided liberalized trade is combined with appropriate government action to address market failures.
Inducing the adoption of conservation technologies: lessons from the Ecuadorian Andes
Authors: WINTERS PAUL , CRISSMAN CHARLES C. , ESPINOSA PATRICIO
Published: October 2004

Programs that provide incentives to induce conservation are often ineffective, leading farmers to abandon conservation once assistance is withdrawn. An alternative to incentives is to offer conservation technologies in conjunction with measures that enhance the short-term profitability of agriculture. Our results indicate that CARE, an international non-governmental organization, has used this approach successfully to promote resource conservation in the Ecuadorian Andes. In particular, the adoption of terraces was found to increase significantly when accompanied by alterations to the agricultural system, such as new crops, biological barriers, and improved agricultural production.
Anthropogenic climate change in a descriptive growth model
Authors: GREINER ALFRED
Published: October 2004

This paper studies the effects of global warming in a descriptive model of endogenous growth. It is assumed that deviations from the pre-industrial global surface temperature negatively affect aggregate output. The paper studies the effects of varying the tax rate and of different abatement activities on the emission of greenhouse gases and on the growth rate. We study both effects for the long-run balanced growth rate and for the growth rate of GDP on the transition path. Using simulations, it is demonstrated that higher abatement activities may both reduce greenhouse gas emissions and lead to higher growth. Further, the second-best abatement share is computed and the corresponding growth rate as well as the social optimum.
Self-organised music
Authors: BLACKWELL TIM , YOUNG MICHAEL
Published: October 2004

Self-organisation, as manifest, for example, by swarms, flocks, herds and other collectives, is a powerful natural force, capable of generating large and sustained structures. Yet the individuals who participate in these social groups may not even be aware of the structures that they are creating. Almost certainly, these structures emerge through the application of simple, local interactions. Improvised music is an uncertain activity, characterised by a lack of top-down organisation and busy, local activity between improvisers. Emerging structures may only be perceivable at a (temporal) distance. The development of higher-level musical structure arises from interactions at lower levels, and we propose here that the self-organisation of social animals provides a very suggestive analogy. This paper builds a model of interactivity based on stigmergy, the process by which social insects communicate indirectly by environment modification. The improvisational element of our model arises from the dynamics of a particle swarm. A process called interpretation extracts musical parameters from the aural environment, and uses these parameters to place attractors in the environment of the swarm, after which stigmergy can take place. The particle positions are reinterpreted as parameterised audio events. This paper describes this model and two applications, Swarm Music and Swarm Granulator.
Musical pattern generation with variable-coupled iterated map networks
Authors: BATTEY BRET
Published: October 2004

This paper introduces the concept of variable-coupled iterated map networks and explores its application to generation of musical textures. Such networks consist of one or more interlinked nodes. Each node consists of an iterated map function with a time-delay factor that schedules successive iterations. The value broadcast by a node can drive the variables and time-delay factor of any other nodes in the network, including itself. Lehmer's Linear Congruence Formula, an iterated map normally used for production of pseudo-random numbers, is explored for its own potential as a pattern generator and is used as the iterated map in the nodes in the examples presented. The capacity of these networks to produce richly gestural behaviours and mid-term modulation of behaviour is demonstrated.
Spontaneous organisation, pattern models, and music
Authors: VISELL YON
Published: October 2004

Pattern theory provides a set of principles for constructing generative models of the information contained in natural signals, such as images or sound. Consequently, it also represents a useful language within which to develop generative systems of art. A pattern theory inspired framework and set of algorithms for interactive computer music composition are presented in the form of a self-organising hidden Markov model – a modular, graphical approach to the representation and spontaneous organisation of sound events in time and in parameter space. The result constitutes a system for composing stochastic music which incorporates creative and structural ideas such as uncertainty, variability, hierarchy and complexity, and which bears a strong relationship to realistic models of statistical physics or perceptual systems. The pattern theory approach to composition provides an elegant set of organisational principles for the production of sound by computer. Further, its machine learning underpinnings suggest many interesting applications to emergent tasks concerning the learning and creative modification of musical forms.
PIWeCS: enhancing human/machine agency in an interactive composition system
Authors: WHALLEY IAN
Published: October 2004

This paper focuses on the infrastructure and aesthetic approach used in PIWeCS: a Public Space Interactive Web-based Composition System. The concern was to increase the sense of dialogue between human and machine agency in an interactive work by adapting Paine's (2002) notion of a conversational model of interaction as a ‘complex system’. The machine implementation of PIWeCS is achieved through integrating intelligent agent programming with MAX/MSP. Human input is through a web infrastructure. The conversation is initiated and continued by participants through arrangements and composition based on short performed samples of traditional New Zealand Maori instruments. The system allows the extension of a composition through the electroacoustic manipulation of the source material.
Modelling storms in sound: the Atmospherics/Weather Works project
Authors: POLLI ANDREA
Published: October 2004

Atmospherics/Weather Works is an interdisciplinary project in the sonification of storms and other meteorological events generated directly from atmospheric data produced by a highly detailed and physically accurate simulation of weather systems. This paper discusses the background, conception and execution of the first stage of the project that has resulted in several performances, stereo recordings, a multi-channel spatialised sound installation, and an interactive sound environment.
An aesthetic comparison of rule-based and genetic algorithms for generating melodies
Authors: BROWN ANDREW R.
Published: October 2004

Various algorithmic techniques are available for generating music, many of which come from the field of artificial intelligence, which is rich with potential in this regard. However, the musical appropriateness of these techniques is less clearly understood. In this paper, I will report on a study that aimed to describe the characteristics of two of these techniques, rule-based and genetic algorithms, as they apply to melody generation. The appropriateness of these characteristics in contributing to well-formed melodies was judged by aesthetic criteria. The results indicate that most combinations of rules, mutations and evolutionary selection result in poor or average melodies, but that careful combination of these techniques can generate melodies that are not simply well-formed but in many cases display some elegance and novelty.
The Decipherable Rigveda: tiróahnyam as an Example
Authors: Thomson Karen
Published: October 2004

The interpretation of the Rigveda presents enormous problems for Vedic scholars, as Stephanie Jamison recently acknowledged in a paper on translating the Rigveda delivered at the Eleventh UCLA Indo-European Conference held in 1999. “It is discouragingly common to find passages in the Rig Veda that do not make sense without the silent supplying of additional material.” (2000: 13)
New editorial team for arq
Authors: Weston Richard
Published: October 2004

Eight years after the first issue, a new team based at the Welsh School of Architecture, Cardiff University is assuming editorial responsibility for arq.
A neglected and ambitious topic central to practice, education and research
Authors: Raz Noam
Published: October 2004

One of the most neglected and urgent issues facing architecture – the substantial fracture between thinking about architecture and engaging in professional practice – was addressed at a two day conference in Cambridge this March (2004). Organized by RIBA East/University of Cambridge CPD for Architects, in association with the University's Department of Architecture and Centre for Research in the Arts, Social Sciences and Humanities, it attracted a sizeable audience of practising architects, senior academics and students. This mix reflected the organizers' ambition to bring together professional and academic perspectives in this interdisciplinary area. The proceedings will be published by Spon during 2005.
Brooklands Avenue housing: a green carpet in Cambridge
Authors: Brooks Alison , Lavington Richard , Grant Andrew
Published: October 2004

Lined against one wall in the reception area of Feilden Clegg Bradley Architects' (FCBA) London office is a row of folding bicycles [2]. All are provided by the firm for the use of staff and partners. A sign of clear commitment to green and humanist causes, credentials which are surely needed by modern architects of large housing schemes. Luckily for the Brooklands Avenue project for 378 dwellings in Cambridge, the architects are supported in this commitment by their client, Countryside Properties. Also luckily, the site contains many magnificent trees. These are mostly around the perimeter, but there is one line forming a strong central spine running north-south. Better still, the west boundary is flanked by Hobson's Brook and a strip of common land.
Classrooms for the Future: ‘an adventure in design’ and research
Authors: Chiles Prue
Published: October 2004

In 2000, the UK Government Department for Education and Skills (DfES) piloted 27 new primary school projects around the country in an initiative called ‘Classrooms of the Future’. Starting with a polemical question: what is ‘a Classroom of the Future’?, it encouraged both a design-led approach and an exploration of where the theory of the classroom design meets teaching practice. David Miliband, the government minister involved, described the challenge as ‘designing inspiring buildings that can adapt to educational and technological change’ (DfES, 2002a). Chris Bissell from the DfES, the initiator of ‘Classrooms of the Future’ summed up his expectations:
‘to deliver the best and most effective education exploiting all the possibilities of the information age, school buildings need to reflect advances in technology. They need to provide a pleasant and comfortable environment for learning and to use architectural and design features to stimulate children's imaginations. And they need to be open to wider use, binding schools to their local communities.’ (DfES, 2002a)
Design as materials research: building a cathedral to last 500 years
Authors: Roberts Nicholas W.
Published: October 2004

‘A city seventy miles square but rarely seventy years deep apart from a small downtown not yet two centuries old and a few other pockets of ancientry, Los Angeles is instant architecture on an instant townscape.’ (Banham, 1971)

Two opposing attitudes shape the built environment of North America: the myth of transience and the myth of permanence.
History Theory Design: a pedagogy of persuasion
Authors: Coleman Nathaniel
Published: October 2004

Architecture students tell stories about their work. These stories are meant to convey information regarding their convictions about design, the motivating concept for a specific design, and the intended meaning of the design. Such stories are calculated to have something to do with the work presented. Often, though, what is said is put forward and accepted as valid simply because it is said. Scrutiny of the relationship between such accounts and the visual or physical evidence frequently reveals a wide gap between intention and result. Credulity of such incongruity encourages a loose way of thinking that fosters a separation of thought (theory) from doing (practice). Concurrently, architecture students at the earliest stages of their education seem to require skill development above all else. But overemphasis on technique undervalues developing conceptual depth. If students are not introduced to design as an ill-defined problem, akin to formulating effective and persuasive arguments, their propensity is to produce work that tends to be ineffectively developed or represented while lacking theoretical sophistication.
The Modern eye-catcher: Mies van der Rohe and sculpture
Authors: Curtis Penelope
Published: October 2004

There are many striking examples of Modernist buildings that house sculptures that are much more traditional than the architecture that surrounds them. To some extent these disparities can be explained by the uncontrolled installation of sculpture, the result either of a lack of concern on the part of the architect or of ignorance of what was to come. Of more interest here, however, is the deliberate positioning of ‘non-Modernist’ sculpture in Modernist buildings. To some extent such juxtapositions require that we reconsider our definition of Modern sculpture. Beyond this, we can ask what figurative sculpture gave abstract architects, and why they used it.
Practice, research, education and arq Australian and Scottish parallels
Authors: WORTHINGTON JOHN
Published: October 2004

arq's interview with Jack Pringle (6/3, pp104–106) puts a strong case for why the profession needs to engage with education and research, if it is to sustain a robust body of knowledge relevant to its clients' continuously changing demands.
Practice, research, education and arq Australian and Scottish parallels
Authors: TOMBS SEBASTIAN
Published: October 2004

Paolo Tombesi's investigation of Australia's Parliament House, Canberra (arq 7/2, pp140–154) shows how the ambitions of Public Sector clients are influenced by the political context. The review by John Sergeant of Weston's excellent biography of Utzon in the same issue (pp183–186), provides some insight into his tragedy and triumph at Sydney: the Opera House.
Size matters: the value of small populations for wintering waterbirds
Authors: Jackson Sarah F. , Kershaw Melanie , Gaston Kevin J.
Published: October 2004

Protecting systematically selected areas of land is a major step towards biodiversity conservation worldwide. Indeed, the identification and designation of protected areas more often than not forms a core component of both national and international conservation policies. In this paper we provide an overview of those Special Protection Areas and Ramsar Sites that have been classified in Great Britain as of 1998/99 for a selection of wintering waterbird species, using bird count data from the Wetland Bird Survey. The performance of this network of sites is remarkable, particularly in comparison with published analyses of networks elsewhere in the world. Nevertheless, the current site‐based approach, whilst having the great benefit of simplicity, is deliberately biased towards aggregating species at the expense of the more dispersed distribution species. To ensure that the network continues successfully to protect nationally and internationally important waterbird populations, efforts now need to concentrate on the derivation of species‐specific representation targets and, in particular, the ways in which these can be incorporated into the site selection process. Although these analyses concern the performance of protected areas for waterbirds in Great Britain, the results have wide‐ranging importance for conservation planning in general and the design of protected area networks.
The importance of species interactions in conservation: the endangered European bitterling Rhodeus sericeus and its freshwater mussel hosts
Authors: Mills Suzanne C. , Reynolds John D.
Published: October 2004

Species conservation may be complicated in symbiotic interactions. Sub‐lethal impacts of human activities on one species may be lethal to other species on which they depend. We investigated the impact of two aspects of eutrophication – changes in phytoplankton and oxygen levels – on the interaction between a freshwater fish that is endangered in several countries, the European bitterling, Rhodeus sericeus, and the unionid mussel hosts that they require for spawning. Reduced concentrations of algae and oxygen each led to a greater proportion of bitterling embryos being ejected prematurely from the mussel hosts. Reduced algal concentrations also led to reductions in mussel ventilation rates and to mussels spending less time with their valves open. Bitterling mortality may have been due to three causes: direct effects of environmental conditions on embryonic survival, active expulsion by mussels when stressed and through responses by mussels that created internal conditions that bitterling embryos could not survive. Our study shows that the sub‐lethal effects of pollution on one species can have lethal effects on another species with which it interacts. Such interactions need to be considered in conservation programmes.
Spatial structure and the control of invasive alien species
Authors: Travis Justin M. J. , Park Kirsty J.
Published: October 2004

Invasive alien species pose a significant threat to biodiversity worldwide and many eradication programmes are now underway in an effort to reduce the impact they may have on native species and ecosystems. The spatial structure of such invasive species populations is likely to have important implications for designing effective control strategies. Here, a simple source–sink population model is used to address the following question: if a population of an invasive alien species is source–sink in nature, what is the best way of dividing limited resources for its control? Results from this model indicate that allocation of resources solely to the source population does not always result in the most effective control strategy. The most efficient control measure is determined by the relative strengths (net gains and losses) of the source and sink populations and, crucially, the nature of dispersal between them. We present a case study for the control of an invasive species illustrating the use of these types of model.
Flower visitors and pollination in the Oriental (Indomalayan) Region
Authors: Corlett Richard T.
Published: October 2004

Current knowledge of flower visitors and pollination in the Oriental Region is summarised. Much less is known about pollination than seed dispersal and the coverage of habitats and taxa in the region is very uneven. The available evidence suggests that pollination in lowland forests is dominated by highly social bees (mainly Trigona and Apis species), with beetles probably the next most important group, followed by other bees and flies. In comparison with the better‐studied Neotropics, large solitary bees, moths, Lepidoptera and vertebrates are relatively less important. These differences are greatest in the canopy of the lowland dipterocarp forests of Southeast Asia, where they probably reflect the unique temporal pattern of floral resource availability resulting from‘general flowering’at supra‐annual intervals. Apis bees (but not Trigona species) are also important in most montane, subtropical and non‐forest habitats. Apart from the figs (Ficus spp.), there are few well‐documented examples of plant species visited by a single potential pollinator and most plant‐pollinator relationships in the region appear to be relatively generalised. The small sizes of most pollinators and the absence of direct human exploitation probably make pollination mutualisms less vulnerable to failure as a result of human impacts than dispersal mutualisms, but more subtle impacts, as a result of altered gene flows, are likely to be widespread. On current evidence, pollination systems in the Oriental Region do not require any specific conservation action, but this review reinforces arguments for making the preservation (or restoration) of habitat connectivity the major focus of Oriental conservation.
Social influences on mammalian circadian rhythms: animal and human studies
Authors: Mistlberger Ralph E. , Skene Debra J.
Published: October 2004

While light is considered the dominant stimulus for entraining (synchronizing) mammalian circadian rhythms to local environmental time, social stimuli are also widely cited as‘zeitgebers’(time‐cues). This review critically assesses the evidence for social influences on mammalian circadian rhythms, and possible mechanisms of action. Social stimuli may affect circadian behavioural programmes by regulating the phase and period of circadian clocks (i.e. a zeitgeber action, either direct or by conditioning to photic zeitgebers), by influencing daily patterns of light exposure or modulating light input to the clock, or by associative learning processes that utilize circadian time as a discriminative or conditioned stimulus. There is good evidence that social stimuli can act as zeitgebers. In several species maternal signals are the primary zeitgeber in utero and prior to weaning. Adults of some species can also be phase shifted or entrained by single or periodic social interactions, but these effects are often weak, and appear to be mediated by social stimulation of arousal. There is no strong evidence yet for sensory‐specific nonphotic inputs to the clock. The circadian phase‐dependence of clock resetting to social stimuli or arousal (the‘nonphotic’phase response curve, PRC), where known, is distinct from that to light and similar in diurnal and nocturnal animals. There is some evidence that induction of arousal can modulate light input to the clock, but no studies yet of whether social stimuli can shift the clock by conditioning to photic cues, or be incorporated into the circadian programme by associative learning. In humans, social zeitgebers appear weak by comparison with light. In temporal isolation or under weak light‐dark cycles, humans may ignore social cues and free‐run independently, although cases of mutual synchrony among two or more group‐housed individuals have been reported. Social cues may affect circadian timing by controlling sleep‐wake states, but the phase of entrainment observed to fixed sleep‐wake schedules in dim light is consistent with photic mediation (scheduled variations in behavioural state necessarily create daily light‐dark cycles unless subjects are housed in constant dark or have no eyes). By contrast, discrete exercise sessions can induce phase shifts consistent with the nonphotic PRC observed in animal studies. The best evidence for social entrainment in humans is from a few totally blind subjects who synchronize to the 24 h day, or to near‐24 h sleep‐wake schedules under laboratory conditions. However, the critical entraining stimuli have not yet been identified, and there are no reported cases yet of social entrainment in bilaterally enucleated blind subjects. The role of social zeitgebers in mammalian behavioural ecology, their mechanisms of action, and their utility for manipulating circadian rhythms in humans, remains to be more fully elaborated.
Comparison of molecular mechanisms mediating cell contact phenomena in model developmental systems: an exploration of universality
Authors: Bowers‐Morrow Vivienne M. , Ali Sinan O. , Williams Keith L.
Published: October 2004

Are there universal molecular mechanisms associated with cell contact phenomena during metazoan ontogenesis? Comparison of adhesion systems in disparate model systems indicates the existence of unifying principles.

Requirements for multicellularity are (a) the construction of three‐dimensional structures involving a crucial balance between adhesiveness and motility; and (b) the establishment of integration at molecular, cellular, tissue, and organismal levels of organization. Mechanisms for (i) cell–cell and cell–substrate adhesion, (if) cell movement, (Hi) cell‐cell communication, (iv) cellular responses, (v) regulation of these processes, and (vi) their integration with patterning, growth, and other developmental processes are all crucial to metazoan development, and must have been present for the emergence and radiation of Metazoa. The principal unifying themes of this review are the dynamics and regulation of cell contact phenomena.

Our knowledge of the dynamic molecular mechanisms underlying cell contact phenomena remains fragmentary. Here we examine the molecular bases of cell contact phenomena using extant model developmental systems (representing a wide range of phyla) including the simplest i.e. sponges, and the eukaryotic protist Dictyostelium discoideum, the more complex Drosophila melanogaster, and vertebrate systems. We discuss cell contact phenomena in a broad developmental context.

The molecular language of cell contact phenomena is complex; it involves a plethora of structurally and functionally diverse molecules, and diverse modes of intermolecular interactions mediated by protein and/or carbohydrate moieties. Reasons for this are presumably the necessity for a high degree of specificity of inter‐molecular interactions, the requirement for a multitude of different signals, and the apparent requirement for an increasingly large repertoire of cell contact molecules in more complex developmental systems, such as the developing vertebrate nervous system. However, comparison of molecular models for dynamic adhesion in sponges and in vertebrates indicates that, in spite of significant differences in the details of the way specific cell–cell adhesion is mediated, similar principles are involved in the mechanisms employed by members of disparate phyla. Universal requirements are likely to include (a) rapidly reversible intermolecular interactions; (b) low‐affinity intermolecular interactions with fast on–off rates; (c) the compounding of multiple intermolecular interactions; (d) associated regulatory signalling systems. The apparent widespread employment of molecular mechanisms involving cadherin‐like cell adhesion molecules suggests the fundamental importance of cadherin function during development, particularly in epithelial morphogenesis, cell sorting, and segregation of cells.
Individual colour patches as multicomponent signals
Authors: Grether Gregory F. , Kolluru Gita R. , Nersissian Karen
Published: October 2004

Colour patches are complex traits, the components of which may evolve independently through a variety of mechanisms. Although usually treated as simple, two‐dimensional characters and classified as either structural or pigmentary, in reality colour patches are complicated, three‐dimensional structures that often contain multiple pigment types and structural features. The basic dermal chromatophore unit of fishes, reptiles and amphibians consists of three contiguous cell layers. Xanthophores and erythrophores in the outermost layer contain carotenoid and pteridine pigments that absorb short‐wave light; iridophores in the middle layer contain crystalline platelets that reflect light back through the xanthophores; and melanophores in the basal layer contain melanins that absorb light across the spectrum. Changes in any one component of a chromatophore unit can drastically alter the reflectance spectrum produced, and for any given adaptive outcome (e.g. an increase in visibility), there may be multiple biochemical or cellular routes that evolution could take, allowing for divergent responses by different populations or species to similar selection regimes. All of the mechanisms of signal evolution that previously have been applied to single ornaments (including whole colour patches) could potentially be applied to the individual components of colour patches. To reach a complete understanding of colour patch evolution, however, it may be necessary to take an explicitly multi‐trait approach. Here, we review multiple trait evolution theory and the basic mechanisms of colour production in fishes, reptiles and amphibians, and use a combination of computer simulations and empirical examples to show how multiple trait evolution theory can be applied to the components of single colour patches. This integrative perspective on animal colouration opens up a host of new questions and hypotheses. We offer specific, testable functional hypotheses for the most common pigmentary (carotenoid, pteridine and melanin) and structural components of vertebrate colour patches.