919 research outputs found

    Designed and emergent tectonics: resituating architectural knowledge

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    Architecture is usually defined through intent while cities come into being out of multiple human actions over a long period of time. This seems to trap us between a view of architecture as authored object, and a view of the city as authorless, evolutionary process. The debate about the autonomous and the contingent object thus, goes back to the separation of architecture from its skill base in craft and building practice that took place in the Renaissance. This separation also includes the operations through which buildings and cities are produced by designers, clients, users, regulatory codes, markets and infrastructures. The resurgence in the debate on the competing claims of autonomy and contingency testifies that since the Renaissance we have failed to develop theories and techniques that address the relationship between authored architecture and authorless contexts. As a result, coupled with commercial forces, recent advancements in digital technology and complexity theory claim architecture and the city as self-organization, dismantling architecture and depriving it from relevance in shaping social capital. If in the Renaissance, architecture was separated from the city, which was the relationship between the ways in which a city was built and the urban fabric? How can we better understand the relationship between the architectural project and the processes that configure the urban structure in which it is situated? This paper argues that for architecture to reclaim its scope as a social discipline it needs to theorise its relationship with the social, the political and the economic processes of its context

    The Anatomy of Knowledge: Quantitative and Qualitative Analysis of the Evolution of Ideas in Space Syntax Conference Articles (1997-2017)

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    Since its inception in the 1970s, space syntax has matured into a theory and a method comprising a set of recurring theoretical and analytical concepts, as well as new ones emerging through the years. How can we trace the evolution of the field through language? How can we analyse the development of ideas in space syntax research? What can we learn from this evolution about knowledge creation in this area? Recognising that language is central to the development of ideas in any field, this paper uses automated text-analyses, focusing more specifically on all papers published in the space syntax symposia proceedings from 1997 to 2017. The purpose is to trace the trajectory of ideas as they were elaborated, used and perhaps changed in the collective work of authors researching within this field in different parts of the world. Firstly, we identify concepts and technical terminology in the field through a combined quantitative and qualitative text analysis. Secondly, we statistically assess the use of these terms, revealing patterns and trends in the evolution of knowledge in space syntax. Thirdly, we compare patterns between established concepts and categories that stabilise over time with concepts emerging more recently. The results from our analysis of networks of concept relationships suggest that: (i) concepts and terms evolve in dependent trajectories; (ii) ideas have evolutionary developments, with some emerging and gaining growing attention, while others showing clear signs of stability, and others losing centrality over time, including networks of what can be termed as ‘canonical’ concepts. We have also identified (iii) an overall decline in the use of early space syntax concepts rooted in social theory and anthropology; (iv) a trend of decreasing conceptual novelty over time; (v) traces of increasing influence by other fields; and finally (vi) signs of a clear ‘technological turn’ in the field

    Food Habits of the Hoary Bat in an Agricultural Landscape

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    Information on diets is fundamental to ecological studies. Prey use by the solitary, tree-roosting hoary bat (Lasiurus cinereus) in agricultural landscapes is not known. We examined the stomach contents and fecal material from carcasses of hoary bats collected during a mortality study at wind turbine sites in southwestern Minnesota. We compared diet of hoary bats to availability of prey to determine whether bats were opportunistic or selective. Food of the hoary bats primarily consisted of lepidopterans (moths; 49-50 %) and coleopterans (beetles; 28-40 %). The abundance of insects in the diet of hoary bats was not proportional to the estimated availability of prey. Hoary bats selected large, soft-bodied insects (e.g., lepidopterans and neuropterans) and avoided small or hard-bodied insects (e.g., coleopterans, dipterans, and hemipterans). We suggest that hoary bats do not select prey based on availability, but rather, select prey that are large and soft-bodied

    Experimental Demonstration of Squeezed State Quantum Averaging

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    We propose and experimentally demonstrate a universal quantum averaging process implementing the harmonic mean of quadrature variances. The harmonic mean protocol can be used to efficiently stabilize a set of fragile squeezed light sources with statistically fluctuating noise levels. The averaged variances are prepared probabilistically by means of linear optical interference and measurement induced conditioning. We verify that the implemented harmonic mean outperforms the standard arithmetic mean strategy. The effect of quantum averaging is experimentally tested both for uncorrelated and partially correlated noise sources with sub-Poissonian shot noise or super-Poissonian shot noise characteristics.Comment: 4 pages, 5 figure

    Understanding the City as a Whole: An Integrative Analysis of Rio de Janeiro and its Informal Settlements

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    Informal settlements are an increasing global phenomenon. Since the mid-century Rio de Janeiro went through a series of paradigmatic changes, trying to cope with this phenomenon. The scope of these interventions ranged from entire eradications of these settlements in the 1960s to present in situ programmes of infrastructural upgrades. Up to now favelas are seen as independent parts of the city, spatial manifestations of urban poverty and intra-urban inequality in the need to be solved. Even recent attempts to integrate favelas socially and spatially with the city failed to remove the physical and conceptual boundaries between the formal and the informal. Underlying these approaches is the perception of those areas as something different, rather than an integral element of the complex urban system. Trying to overcome the fragmentation of the city this study combines formal and informal parts into an integrated model of the whole city. Following a syntactical analysis using GIS mapping and space syntax, this study explores the morphology of favelas in the context of metropolitan Rio throughout different scales and in relation to their topographic location. 60 different local areas are then selected and compared against each other according to their configurational characteristics. The analytic results highlight the affordances and constrains of informal and formal structures. Understanding the particularities of those two differently perceived systems and the ways in which they interact with each other can inform future analysis and policymaking

    PI3K mediated activation of GSK‑3β reduces at‑level primary afferent growth responses associated with excitotoxic spinal cord injury dysesthesias

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    Background Neuropathic pain and sensory abnormalities are a debilitating secondary consequence of spinal cord injury (SCI). Maladaptive structural plasticity is gaining recognition for its role in contributing to the development of post SCI pain syndromes. We previously demonstrated that excitotoxic induced SCI dysesthesias are associated with enhanced dorsal root ganglia (DRG) neuronal outgrowth. Although glycogen synthase kinase-3β (GSK-3β) is a known intracellular regulator neuronal growth, the potential contribution to primary afferent growth responses following SCI are undefined. We hypothesized that SCI triggers inhibition of GSK-3β signaling resulting in enhanced DRG growth responses, and that PI3K mediated activation of GSK-3β can prevent this growth and the development of at-level pain syndromes. Results Excitotoxic SCI using intraspinal quisqualic acid (QUIS) resulted in inhibition of GSK-3β in the superficial spinal cord dorsal horn and adjacent DRG. Double immunofluorescent staining showed that GSK-3βP was expressed in DRG neurons, especially small nociceptive, CGRP and IB4-positive neurons. Intrathecal administration of a potent PI3-kinase inhibitor (LY294002), a known GSK-3β activator, significantly decreased GSK-3βP expression levels in the dorsal horn. QUIS injection resulted in early (3 days) and sustained (14 days) DRG neurite outgrowth of small and subsequently large fibers that was reduced with short term (3 days) administration of LY294002. Furthermore, LY294002 treatment initiated on the date of injury, prevented the development of overgrooming, a spontaneous at-level pain related dysesthesia. Conclusions QUIS induced SCI resulted in inhibition of GSK-3β in primary afferents and enhanced at-level DRG intrinsic growth (neurite elongation and initiation). Early PI3K mediated activation of GSK-3β attenuated QUIS-induced DRG neurite outgrowth and prevented the development of at-level dysesthesias.ECU Open Access Publishing Support Fun

    Expanding Access to Parasite-based Malaria Diagnosis through Retail Drug shops in Tanzania: Evidence from a Randomized Trial and Implications for Treatment.

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    Tanzania has seen a reduction in the fraction of fevers caused by malaria, likely due in part to scale-up of control measures. While national guidelines require parasite-based diagnosis prior to treatment, it is estimated that more than half of suspected malaria treatment-seeking in Tanzania initiates in the private retail sector, where diagnosis by malaria rapid diagnostic test (RDT) or microscopy is illegal. This pilot study investigated whether the introduction of RDTs into Accredited Drug Dispensing Outlets (ADDOs) under realistic market conditions would improve case management practices.\ud Dispensers from ADDOs in two intervention districts in Tanzania were trained to stock and perform RDTs and monitored quarterly. Each district was assigned a different recommended retail price to evaluate the need for a subsidy. Malaria RDT and artemisinin-based combination therapy (ACT) uptake and availability were measured pre-intervention and 1 year post-intervention through structured surveys of ADDO owners and exiting customers in both intervention districts and one contiguous control district. Descriptive analysis and logistic regression were used to compare the three districts and identify predictive variables for testing. A total of 310 dispensers from 262 ADDOs were trained to stock and perform RDTs. RDT availability in intervention ADDOs increased from 1% (n = 172) to 73% (n = 163) during the study; ACT medicines were available in 75% of 260 pre-intervention and 68% of 254 post-intervention ADDOs. Pre-treatment testing performed within the ADDO increased from 0 to 65% of suspected malaria patients who visited a shop (95% CI 60.8-69.6%) with no difference between intervention districts. Overall parasite-based diagnosis increased from 19 to 74% in intervention districts and from 3 to 18% in the control district. Prior knowledge of RDT availability (aOR = 1.9, p = 0.03) and RDT experience (aOR = 1.9, p = 0.01) were predictors for testing. Adherence data indicated that 75% of malaria positives received ACT, while 3% of negatives received ACT. Trained and supervised ADDO dispensers in rural Tanzania performed and sold RDTs under real market conditions to two-thirds of suspected malaria patients during this one-year pilot. These results support the hypothesis that introducing RDTs into regulated private retail sector settings can improve malaria testing and treatment practices without an RDT subsidy. Trial registration ISRCTN ISRCTN14115509

    Numerical simulation of blood flow and pressure drop in the pulmonary arterial and venous circulation

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    A novel multiscale mathematical and computational model of the pulmonary circulation is presented and used to analyse both arterial and venous pressure and flow. This work is a major advance over previous studies by Olufsen et al. (Ann Biomed Eng 28:1281–1299, 2012) which only considered the arterial circulation. For the first three generations of vessels within the pulmonary circulation, geometry is specified from patient-specific measurements obtained using magnetic resonance imaging (MRI). Blood flow and pressure in the larger arteries and veins are predicted using a nonlinear, cross-sectional-area-averaged system of equations for a Newtonian fluid in an elastic tube. Inflow into the main pulmonary artery is obtained from MRI measurements, while pressure entering the left atrium from the main pulmonary vein is kept constant at the normal mean value of 2 mmHg. Each terminal vessel in the network of ‘large’ arteries is connected to its corresponding terminal vein via a network of vessels representing the vascular bed of smaller arteries and veins. We develop and implement an algorithm to calculate the admittance of each vascular bed, using bifurcating structured trees and recursion. The structured-tree models take into account the geometry and material properties of the ‘smaller’ arteries and veins of radii ≥ 50 μ m. We study the effects on flow and pressure associated with three classes of pulmonary hypertension expressed via stiffening of larger and smaller vessels, and vascular rarefaction. The results of simulating these pathological conditions are in agreement with clinical observations, showing that the model has potential for assisting with diagnosis and treatment for circulatory diseases within the lung
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