139 research outputs found

    Conservation or Change for Works of the Modern Movement

    Get PDF
    The Modern Movement in architecture, in so far as any such movement can be defined, was predicated on the idea that architecture had to change to reflect the radical technological advances that had occurred during the century preceding its formulation, and also to reflect the changing social needs that those advances had generated. Architecture, it was felt, had ossified and lost vitality as a result of not recognizing those changes. A century has now passed since the Modern Movement first formulated this program, and technical advances and the social changes they induce have of course by no means ceased, rather they have accelerated. So, it seems legitimate to say that a technologically – and socially – determined architecture should reflect these further advances and changes. The evolution continues. But does that mean that each Modern Movement building created at a particular point in that evolution has in itself to continue to change in order to “catch up” with the evolution subsequent to its creation? It is a question that has importance when it comes to considering the conservation of Modern Movement architecture. It is an assertion that would ignore the formal element in architecture

    It may be time to revisit the old idea of moving the seat of British government out of London

    Get PDF
    London continues to dominate British public life, with political decision-making centralised to an almost unbelievable degree. Previous reformers have posited separating the financial and political capitals of the UK, by moving the political element elsewhere, with the Yorkshire moors even being suggested. James Dunnett argues that it may be time to revisit that radical proposal

    Linkage of intermediate damage in metallics to material and fracture models

    Get PDF
    The main objective of this work was to identify the effect parameters in the method of material testing have on three constitutive models that are commonly used to predict high strain rate, large strain material behaviour. These are the Goldthorpe path-dependent model, the Goldthorpe-modified Armstrong-Zerilli model and the path-dependent fracture model, also developed by Goldthorpe. To investigate the material models, numerous interrupted tensile, torsion and compression tests were performed. This led to key improvements to the image analysis and acquisition steps of the interrupted tensile test methodology used to quantify necking. Whilst the models used to predict dynamic deformation and damage to very high strains for ballistic impact applications, such as the Goldthorpe path-dependent failure model, incorporate temperature and strain-rate dependence, they do not consider the effect of specimen size or the microstructural length scale. To investigate this, geometrically similar specimens spanning a scale range of 100:1 were tested quasi-statically to failure. Images of neck evolution were acquired using optical techniques for large specimens, and in-situ scanning electron microscope testing for small specimens, to examine the dependence of neck geometry on a broad range of specimen sizes. Size effects typically arise when the smallest specimen dimension is on the order of a microstructural length (e.g. grain size, dislocation mean free path, etc.), or in the presence of significant plastic strain gradients, which increase the density of geometrically necessary dislocations. An assumption also made to develop the models is that material deformation is isotropic. This encouraged a study where calibrated cameras, multiple view geometry and edge detection tools were used to measure the anisotropic deformation of uniaxially loaded cylindrical specimens. For this investigation tension tests were performed at quasi-static strain rates on a variety of materials using screw-driven test machines. The elliptically evolving specimens were then measured at multiple interruptions to determine the true direct stress and strain at the neck. It is hoped the anisotropic data presented in this thesis will aid model development.Open Acces

    Estimation of time to point of closest approach for collision avoidance and separation systems

    Get PDF
    This paper proposes a method for estimating the amount of time until the point of closest approach (TPCA) between two aircraft. A range of simple methods which use derivatives to estimate the time to collision are analysed. These methods are only accurate when the angle subtended between the direction of the relative velocity vector, and the bearing of the intruder aircraft is small. An extended method is developed which calculates the exact TPCA from relative distance and bearing measurements. Representative levels of Gaussian white noise are introduced to the core equation variables for both the derivative and extended methods. It is found that as we increase the value of Ξ, the extended method's accuracy increases beyond that of the derivative method. A fusion algorithm is developed to switch between methods and is shown to perform well for a range of conflicts. When the relative velocity between the two aircraft is small, the signal to noise ratio on the relative velocity variable reduces causing large errors to the TPCA estimation. It is therefore concluded that at a certain relative velocity threshold, Vk (dependant on sensor and filter performance) both the derivative and extended TPCA estimation methods would become undesirable as risk estimators. It is suggested that in these situations distance could be better to use since it can be measured directly

    Failure boundary estimation for lateral collision avoidance manoeuvres

    Get PDF
    This paper proposes a method for predicting the point at which a simple lateral collision avoidance manoeuvre fails. It starts by defining the kinematic failure boundary for a range of conflict geometries and velocities. This relies on the assumption that the ownship aircraft is able to turn instantaneously. The dynamics of the ownship aircraft are then introduced in the form of a constant rate turn model. With knowledge of the kinematic boundary, two optimisation algorithms are used to estimate the location of the real failure boundary. A higher fidelity simulation environment is used to compare the boundary predictions. The shape of the failure boundary is found to be heavily connected to the kinematic boundary prediction. Some encounters where the ownship aircraft is travelling slower than the intruder were found to have large failure boundaries. The optimisation method is shown to perform well, and with alterations to the turn model, its accuracy can be improved. The paper finishes by demonstrating how the failure boundary is used to determine accurate collision avoidance logic. This is expected to significantly reduce the size and complexity of the verification problem

    Peoples’ use of, and concerns about, green space networks: A case study of Birchwood, Warrington New Town, UK

    Get PDF
    Cultural services provided by green space networks and in particular leisure and recreational opportunities are central to the quality of life of those living in urban areas. However, the literature concerned with green space networks has mainly focussed on planning aspects rather than on recreational use. The aim of this study was to evaluate the recreational use of, and concerns about, a naturalistic green space network. The case study location was the naturalistic woodland framework in Birchwood, Warrington, UK, known as Birchwood Forest Park. Non-participant observation and content analysis of local archives were used to collect quantitative and qualitative data. Birchwood Forest Park was used more for leisure activities (52.8%, N = 1,825; i.e. recreation, sports or play) than for utilitarian purposes (47.2%, N = 1,825; i.e. as walking or cycling thoroughfare). However, utilitarian walking (30%, N = 1,825) was the most frequent type of activity observed. The maintenance of the naturalistic woodland framework was the most frequent concern mentioned in the local archives (33.3%, N = 234). This case study suggests that the recreational patterns in, as well as peoples’ concerns about, naturalistic urban landscapes may be a factor of high quality maintenance and associated local aesthetic and cultural perceptions. In developing, planning or managing comprehensive urban green space networks it is important to ensure that natural looking scenes are well maintained and that the local community is culturally connected to such scenes

    Relaxation of the criteria for entry to the UK Clozapine Central Non-Rechallenge Database: a modelling study

    Get PDF
    Background Clozapine is uniquely effective in treatment-resistant psychosis. In the UK, patients must discontinue clozapine indefinitely if they are placed on the Central Non-Rechallenge Database (CNRD) after their haematological parameters fall below particular thresholds. Under exceptional circumstances, patients can be rechallenged on clozapine under an off-licence agreement. In the USA in 2015, restrictive practice was discontinued to allow greater flexibility for clozapine maintenance. The absolute neutrophil count leading to treatment interruption was lowered from less than 1·5 × 109/L to less than 1·0 × 109/L and platelet and white cell count monitoring were ceased. We aimed to investigate the implications of a similar policy change on clozapine use in the UK. Methods This was a modelling study of all patients registered on the UK CNRD. First, we determined the proportion of patients placed on the database in the UK who would have had to discontinue clozapine treatment under the US Food and Drug Administration (FDA) criteria. Second, we compared the haematological characteristics of patients who did or did not meet FDA criteria for discontinuing clozapine, including the time to registration from clozapine initiation and the proportion of cases of severe neutropenia at registration. Third, we investigated the success rates of clozapine re-challenge for patients that had been placed on the CNRD. Successful rechallenge was defined as no recurrence of CNRD registration. Findings Between May 2, 2002 and March 1, 2021, 3731 patients were placed on the CNRD, with a mean age of 47 years (SD 15), including 1420 (38%) women and 2311 (62%) men, of whom 3089 (83%) were White, 360 (10%) were Black, 190 (5%) were Asian, and 92 (2%) were classified as other. 566 (15%) of 3731 patients met the equivalent criteria for clozapine discontinuation under the FDA guidelines. The median time to CNRD registration from clozapine initiation was 1·6 years (IQR 0·2–4·9). Data for 519 rechallenged patients were examined; 419 (81%) were successful. Clozapine rechallenge success rates were broadly similar between individuals who did not meet the US CNRD registration criteria (36 [78%] of 46) and those who did meet the criteria (383 [81%] of 473). Interpretation Implementing the revised FDA monitoring criteria in the UK would substantially reduce clozapine discontinuation for haematological reasons, which would greatly improve the mental health outcomes of these patients without having a major effect on their physical health

    University choice : which attributes matter when you are paying the full price?

    Get PDF
    This article presents the results from a longitudinal study of students’ choice of university in England. Students were surveyed initially when applying for university (Wave One) and then again when they were about to embark on their chosen course (Wave Two). The results from Wave Two demonstrated a high degree of consistency with the Wave One findings: course and university reputation are far more important and fees are relatively unimportant. However, a key result across both waves was that patterns of utility for students with no parental experience of university were significantly different from students whose parents had attended university. The utility associated with different levels of entry qualifications, of fees and of university and course reputation, differed between social groups. The study suggests that the benefits of going to a highly rated university may be undervalued in families that have no direct experience of higher education. In addition, whilst females are more significantly put off by universities with low entry requirements, the qualitative attitudinal statements included in the follow-up study seem to indicate that so-called ‘softer’ factors may also influence their choice.Peer reviewedFinal Accepted Versio

    Mutant huntingtin's effects on striatal gene expression in mice recapitulate changes observed in human Huntington's disease brain and do not differ with mutant huntingtin length or wild-type huntingtin dosage

    Get PDF
    To test the hypotheses that mutant huntingtin protein length and wild-type huntingtin dosage have important effects on disease-related transcriptional dysfunction, we compared the changes in mRNA in seven genetic mouse models of Huntington's disease (HD) and postmortem human HD caudate. Transgenic models expressing short N-terminal fragments of mutant huntingtin (R6/1 and R6/2 mice) exhibited the most rapid effects on gene expression, consistent with previous studies. Although changes in the brains of knock-in and full-length transgenic models of HD took longer to appear, 15- and 22-month CHL2Q150/Q150, 18-month HdhQ92/Q92 and 2-year-old YAC128 animals also exhibited significant HD-like mRNA signatures. Whereas it was expected that the expression of full-length huntingtin transprotein might result in unique gene expression changes compared with those caused by the expression of an N-terminal huntingtin fragment, no discernable differences between full-length and fragment models were detected. In addition, very high correlations between the signatures of mice expressing normal levels of wild-type huntingtin and mice in which the wild-type protein is absent suggest a limited effect of the wild-type protein to change basal gene expression or to influence the qualitative disease-related effect of mutant huntingtin. The combined analysis of mouse and human HD transcriptomes provides important temporal and mechanistic insights into the process by which mutant huntingtin kills striatal neurons. In addition, the discovery that several available lines of HD mice faithfully recapitulate the gene expression signature of the human disorder provides a novel aspect of validation with respect to their use in preclinical therapeutic trial

    Assessing mangrove restoration practices using species‐interaction networks

    Get PDF
    Mangroves are uniquely important ecosystems, for preserving biodiversity, sustaining livelihoods and mitigating against climate change. However they are degraded globally and are therefore a priority for ecosystem restoration. To date, the assessment of mangrove restoration outcomes is generally poor, and the limited studies that do exist are focussed largely on forest area. Thus, more holistic ways of assessing the outcomes of mangrove restoration projects on biodiversity and associated ecological processes are urgently needed. Ecological networks are a useful tool for simultaneously examining both. Here, we assessed the utility of using species-interaction networks for evaluating mangrove restoration outcomes for the first time. We compared the structure and complexity of mangrove ecological networks in replicated ‘Monoculture Reforestation’, ‘Mixed Species Regeneration’ and ‘Reference Forest’ plots in two study areas in Sulawesi, Indonesia, an estuarine and a coastal fringe mangrove system. We also combined and evaluated sampling methods, utilising traditional plant-animal sampling while also integrating video recording data in a novel way. We found significant differences in the structure and complexity of mangrove networks between restored and natural plots, with contrasting effects between the two sites. Our results show differences in the complex ways in which taxa interact in mangrove restoration projects, which would be overlooked if common biodiversity metrics such as species-richness were used alone, with consequences for the restoration of ecosystem functioning. We also highlight the utility of video recording data collection for constructing species interaction networks, overcoming the detrimental impacts of observer presence for some key species
    • 

    corecore