A Hybrid Multi-Distance Phase and Broadband Spatially Resolved Spectrometer and Algorithm for Resolving Absolute Concentrations of Chromophores in the Near-Infrared Light Spectrum

For resolving absolute concentration of tissue chromophores in the human adult brain with near-infrared spectroscopy it is necessary to calculate the light scattering and absorption, at multiple wavelengths with some depth resolution. To achieve this we propose an instrumentation configuration that combines multi-distance frequency and broadband spectrometers to quantify chromophores in turbid media by using a hybrid spatially resolved algorithm. Preliminary results in solid phantoms as well as liquid dynamic homogeneous and inhomogeneous phantoms and in-vivo muscle measurements showed encouraging results

Exploring galaxy evolution with generative models

Context. Generative models open up the possibility to interrogate scientific data in a more data-driven way. Aims: We propose a method that uses generative models to explore hypotheses in astrophysics and other areas. We use a neural network to show how we can independently manipulate physical attributes by encoding objects in latent space. Methods: By learning a latent space representation of the data, we can use this network to forward model and explore hypotheses in a data-driven way. We train a neural network to generate artificial data to test hypotheses for the underlying physical processes. Results: We demonstrate this process using a well-studied process in astrophysics, the quenching of star formation in galaxies as they move from low-to high-density environments. This approach can help explore astrophysical and other phenomena in a way that is different from current methods based on simulations and observations.Comment: Published in A&A. For code and further details, see http://space.ml/proj/explor

'Special K' and a loss of cell-to-cell adhesion in proximal tubule-derived epithelial cells: modulation of the adherens junction complex by ketamine

Ketamine, a mild hallucinogenic class C drug, is the fastest growing ‘party drug’ used by 16–24 year olds in the UK. As the recreational use of Ketamine increases we are beginning to see the signs of major renal and bladder complications. To date however, we know nothing of a role for Ketamine in modulating both structure and function of the human renal proximal tubule. In the current study we have used an established model cell line for human epithelial cells of the proximal tubule (HK2) to demonstrate that Ketamine evokes early changes in expression of proteins central to the adherens junction complex. Furthermore we use AFM single-cell force spectroscopy to assess if these changes functionally uncouple cells of the proximal tubule ahead of any overt loss in epithelial cell function. Our data suggests that Ketamine (24–48 hrs) produces gross changes in cell morphology and cytoskeletal architecture towards a fibrotic phenotype. These physical changes matched the concentration-dependent (0.1–1 mg/mL) cytotoxic effect of Ketamine and reflect a loss in expression of the key adherens junction proteins epithelial (E)- and neural (N)-cadherin and β-catenin. Down-regulation of protein expression does not involve the pro-fibrotic cytokine TGFβ, nor is it regulated by the usual increase in expression of Slug or Snail, the transcriptional regulators for E-cadherin. However, the loss in E-cadherin can be partially rescued pharmacologically by blocking p38 MAPK using SB203580. These data provide compelling evidence that Ketamine alters epithelial cell-to-cell adhesion and cell-coupling in the proximal kidney via a non-classical pro-fibrotic mechanism and the data provides the first indication that this illicit substance can have major implications on renal function. Understanding Ketamine-induced renal pathology may identify targets for future therapeutic intervention

Visualising London's Suburbs

2 - 4 April 200

Barriers & facilitators to extended working life : a focus on a predominately female ageing workforce

Many countries are reforming their pension systems so people stay in work for longer to improve the long-term sustainability of public finances to support an increasing older population. This research aimed to explore the factors that enable or inhibit people to extend working life (EWL) in a large UK based retail organisation. Semi-structured interviews were carried out with a purposive sample (n=30): 15 employees aged ≥ 60 and 15 supervisors supporting these employees. Older workers were predominately female, reflecting the gender profile of the older workers in the organisation. Older workers and supervisors reported that key facilitators to EWL were: good health, the perception that older workers are of value; flexibility and choice; the need for an ongoing conversation across the life-course; the social and community aspect of work as a facilitator to EWL; and, the financial necessity to EWL. Perceived barriers to EWL included poor health, negative impacts of work on health, and a lack of respect and support

Avoiding Wireheading with Value Reinforcement Learning

How can we design good goals for arbitrarily intelligent agents? Reinforcement learning (RL) is a natural approach. Unfortunately, RL does not work well for generally intelligent agents, as RL agents are incentivised to shortcut the reward sensor for maximum reward -- the so-called wireheading problem. In this paper we suggest an alternative to RL called value reinforcement learning (VRL). In VRL, agents use the reward signal to learn a utility function. The VRL setup allows us to remove the incentive to wirehead by placing a constraint on the agent's actions. The constraint is defined in terms of the agent's belief distributions, and does not require an explicit specification of which actions constitute wireheading.Comment: Artificial General Intelligence (AGI) 201

Do the suburbs exist? Discovering complexity and specificity in suburban built form

In human geography cities are routinely acknowledged as complex and dynamic built environments. This description is rarely extended to the suburbs, which are generally regarded as epiphenomena of the urbs and therefore of little intrinsic theoretical interest in themselves. This article presents a detailed critique of this widely held assumption by showing how the idea of 'the suburban' as an essentially non-problematic domain has been perpetuated from a range of contrasting disciplinary perspectives, including those that directly address suburban subject matter. The result has been that attempts to articulate the complex social possibilities of suburban space are easily caught between theories of urbanisation that are insensitive to suburban specificity and competing representations of the suburb that rarely move beyond the culturally specific to consider their generic significance. This article proposes that the development of a distinctively suburban theory would help to undermine one-dimensional approaches to the built environment by focusing on the relationship between social organisation and the dynamics of emergent built form

A multi-disciplinary perspective on the built environment: Space Syntax and cartography – the communication challenge

8-11 June 2009