Tropical Architecture and the West Indies: from military advances and tropical medicine,to Robert Gardner-Medwin and the networks of tropical modernism

The history of modern Tropical Architecture has largely focused on the region of West Africa, however this paper demonstrates that additional strains were being developed elsewhere, preceding the African examples. Indeed, Tropical Architecture, far from being a mid-twentieth century phenomenon, has a much longer history, stretching back into the colonial settlements of the eighteenth century and continued by the tropical medicine contributions of the early twentieth century, particularly in the British West Indies. This paper considers some of these early examples, before investigating the work produced by Robert Gardner-Medwin, along with his small team that included Leo De Syllas and Gordon Cullen, during the Second World War in the West Indies. Their work there as part of the ‘development and welfare’ programme was considered, ‘building research’, concerned with materials, pragmatic decisions and housing, and, whilst it was unacknowledged at the time, was clearly indebted to the earlier military and hygiene models. Nevertheless, the work they undertook was highly influential in the development of modern tropical architecture, and in particular the buildings that were later produced in West Africa: it helped to formalise this canon, and unified the previously fragmented and disparate out-workings of the Metropolis. Gardner-Medwin, therefore, can be considered an agent of Empire, a key-player in the extension of British architects operating as the knowledge makers, not only in the period of colonial rule, but crucially, afterwards. This is further manifest through his involvement in UN housing missions to South East Asia and his contribution to the Tropical Architecture Conference held at University College, London, in 1953.     

The Limehouse Link: the architectural and cultural history of a monumental road tunnel in London's Docklands

In the Docklands area of London lies the ‘Limehouse Link’, a dual-bore road tunnel used by around 80,000 cars each day. A monumental and highly expensive piece of construction, the Limehouse Link has nonetheless received almost no attention from architectural historians or others concerned with the history of construction, engineering or urban development.

This article provides an introduction to the Limehouse Link, explaining some of the fundamental characteristics of its construction and position in London's urban landscape. More importantly, the article then considers how one might understand an everyday yet monumental construction such as this: a tunnel without obvious aesthetic form, design intent or symbolic meaning, but which nonetheless has an undeniable presence in the city. The Limehouse Link is therefore interpreted in terms of the car driver's immersive experience of the tunnel, more active constructions of this experience through sensory qualities of sound, representations of the tunnel in different media and art, ways of knowing the history of Limehouse, and, in particular, as a kind of aesthetic experience. The article concludes that driving through the Limehouse Link is to engage in a different way of knowing the postmodern city.     

On the power of deep pushdown stacks

Inspired by recent work of Meduna on deep pushdown automata, we consider the computational power of a class of basic program schemes, NPSDS _s , based around assignments, while-loops and non-deterministic guessing but with access to a deep pushdown stack which, apart from having the usual push and pop instructions, also has deep-push instructions which allow elements to be pushed to stack locations deep within the stack. We syntactically define sub-classes of NPSDS _s by restricting the occurrences of pops, pushes and deep-pushes and capture the complexity classes NP and PSPACE. Furthermore, we show that all problems accepted by program schemes of NPSDS _s are in EXPTIME.     

Xenobiotic Metabolism: The Effect of Acute Kidney Injury on Non-Renal Drug Clearance and Hepatic Drug Metabolism

Acute kidney injury (AKI) is a common complication of critical illness, and evidence is emerging that suggests AKI disrupts the function of other organs. It is a recognized phenomenon that patients with chronic kidney disease (CKD) have reduced hepatic metabolism of drugs, via the cytochrome P450 (CYP) enzyme group, and drug dosing guidelines in AKI are often extrapolated from data obtained from patients with CKD. This approach, however, is flawed because several confounding factors exist in AKI. The data from animal studies investigating the effects of AKI on CYP activity are conflicting, although the results of the majority do suggest that AKI impairs hepatic CYP activity. More recently, human study data have also demonstrated decreased CYP activity associated with AKI, in particular the CYP3A subtypes. Furthermore, preliminary data suggest that patients expressing the functional allele variant CYP3A5*1 may be protected from the deleterious effects of AKI when compared with patients homozygous for the variant CYP3A5*3, which codes for a non-functional protein. In conclusion, there is a need to individualize drug prescribing, particularly for the more sick and vulnerable patients, but this needs to be explored in greater depth.     

Interpreting computer code in a computer‐based learning system for novice programmers

Although the principles of writing compilers and interpreters are well known, we have found that the ideas needed to develop an interpreter for the express purpose of allowing direct interaction with the running code do not yet appear to have been published in an academic context. We describe a programming method that can be used for the production of an interpreter for common object‐oriented languages such as C++, Java and C#. The main purpose of the interpreter is to parse short, relatively simple programs and allow direct interaction between the user and the running code. Such a system is useful for projects such as OGRE, which is an educational tool allowing students to visualize in three‐dimensional graphics the state of a program as it runs. The interpreter works by first parsing the source code and building up a data structure capable of representing the program's source code in a form that can be used to both run the program and extract detailed information from the running program. This extraction allows for novel uses of the interpreter, such as forming the basis for a visualization system that must display and provide such information to the user as they watch their executing program. This paper considers the construction of such an interpreter specifically for C++, but the principles should be the same for other similar languages such as Java and C#. We cover the main tasks required of the programmer to create and use the data structure, highlighting areas such as its design, initial construction during parsing, and techniques required to use it for interpretation. These include the ability for the data structure to intelligently clone subsets of itself when multiple copies of one of its elements are required by the running program, how it handles C++'s complicated function overloading and overriding rules, and how inheritance and polymorphism can be supported. Copyright © 2005 John Wiley & Sons, Ltd.     

Autonomous Adaptive Agents for Single Seller Sealed Bid Auctions

In developing open, heterogeneous and distributed multi-agent systems researchers often face a problem of facilitating negotiation and bargaining amongst agents. It is increasingly common to use auction mechanisms for negotiation in multi-agent systems. The choice of auction mechanism and the bidding strategy of an agent are of central importance to the success of the agent model. Our aim is to determine the best agent learning algorithm for bidding in a variety of single seller auction structures in both static environments where a known optimal strategy exists and in complex environments where the optimal strategy may be constantly changing. In this paper we present a model of single seller auctions and describe three adaptive agent algorithms to learn strategies through repeated competition. We experiment in a range of auction environments of increasing complexity to determine how well each agent performs, in relation to an optimal strategy in cases where one can be deduced, or in relation to each other in other cases. We find that, with a uniform value distribution, a purely reactive agent based on Cliff’s ZIP algorithm for continuous double auctions (CDA) performs well, although is outperformed in some cases by a memory based agent based on the Gjerstad Dickhaut agent for CDA.     

Appearance-based face recognition and light-fields

Arguably the most important decision to be made when developing an object recognition algorithm is selecting the scene measurements or features on which to base the algorithm. In appearance-based object recognition, the features are chosen to be the pixel intensity values in an image of the object. These pixel intensities correspond directly to the radiance of light emitted from the object along certain rays in space. The set of all such radiance values over all possible rays is known as the plenoptic function or light-field. In this paper, we develop a theory of appearance-based object recognition from light-fields. This theory leads directly to an algorithm for face recognition across pose that uses as many images of the face as are available, from one upwards. All of the pixels, whichever image they come from, are treated equally and used to estimate the (eigen) light-field of the object. The eigen light-field is then used as the set of features on which to base recognition, analogously to how the pixel intensities are used in appearance-based face and object recognition.