Aiton Court: Relocating Conservation between Poverty and Modern Idealism

Aiton Court, in Johannesburg, is a case study in how heritage and economics clash in economically constrained cities. This iconic and formally innovative Modern apartment block from 1937 is located in an area where the income levels of tenants are now very low. Although the building is protected by legislation, the viability of its restoration is being further tested by a rent boycott. The article covers the building’s history, and questions how to approach its conservation differently, given the strong demand for housing at a cost level that would be excluded by purely market–led gentrification. We propose that locating conservation strategies in relation to the building’s history and to other subsidies aimed at the public good may provide other routes to preserving Aiton Court

Aiton Court: Relocating Conservation between Poverty and Modern Idealism

Aiton Court, in Johannesburg, is a case study in how heritage and economics clash in economically constrained cities. This iconic and formally innovative Modern apartment block from 1937 is located in an area where the income levels of tenants are now very low. Although the building is protected by legislation, the viability of its restoration is being further tested by a rent boycott. The article covers the building’s history, and questions how to approach its conservation differently, given the strong demand for housing at a cost level that would be excluded by purely market–led gentrification. We propose that locating conservation strategies in relation to the building’s history and to other subsidies aimed at the public good may provide other routes to preserving Aiton Court

Ground-layer wavefront reconstruction from multiple natural guide stars

Observational tests of ground layer wavefront recovery have been made in open loop using a constellation of four natural guide stars at the 1.55 m Kuiper telescope in Arizona. Such tests explore the effectiveness of wide-field seeing improvement by correction of low-lying atmospheric turbulence with ground-layer adaptive optics (GLAO). The wavefronts from the four stars were measured simultaneously on a Shack-Hartmann wavefront sensor (WFS). The WFS placed a 5 x 5 array of square subapertures across the pupil of the telescope, allowing for wavefront reconstruction up to the fifth radial Zernike order. We find that the wavefront aberration in each star can be roughly halved by subtracting the average of the wavefronts from the other three stars. Wavefront correction on this basis leads to a reduction in width of the seeing-limited stellar image by up to a factor of 3, with image sharpening effective from the visible to near infrared wavelengths over a field of at least 2 arc minutes. We conclude that GLAO correction will be a valuable tool that can increase resolution and spectrographic throughput across a broad range of seeing-limited observations.Comment: 25 pages, 8 figures, to be published in Astrophys.

Influence of pregnancy on gene expression in rabbit articular cartilage

AbstractObjective: Articular cartilage is known to be influenced by estrogen and the pregnancy-associated hormone, relaxin,in vitro. Such observations have raised the possibility that articular cartilage in females may be subjected to unique regulatory influences by such hormonesin vivo. The purpose of this study was to evaluate mRNA levels for several relevant molecules in the articular cartilage of pregnant and non-pregnant rabbits.Design: Total RNA was extracted from New Zealand White rabbit knee articular cartilage using the TRIspin method. The total RNA was reverse transcribed and analysed by the sensitive molecular technique of semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) using rabbit specific primer sets.Results: Total RNA yield from articular cartilage from primigravida rabbits was reduced to 65% of age-matched control values (P=0.0003); however the yield from multiparous animals was not significantly depressed. In both cases, DNA yields were not affected by pregnancy. There was a general tendency for depressed mRNA levels for most genes investigated in cartilage from pregnant animals. Articular cartilage from multiparous rabbits showed a significant decrease in mRNA levels for relevant molecules such as type II collagen, biglycan, collagenase and tissue inhibitors of metalloproteinases (TIMP)-1, as well as necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS) and cyclo-oxygenase 2 (COX-2). Transcripts for collagenase and lumican were significantly lower in cartilage from primigravida rabbits. Transforming growth factor β1 (TGF-β1) transcript levels were significantly decreased in both pregnant groups. In contrast, basic fibroblast growth factor (bFGF) and insulin-like growth factor-2 (IGF-2) mRNA levels were significantly decreased in cartilage from primigravida rabbits, whereas transcripts for these molecules were upregulated in the cartilage of multiparous rabbits.Conclusions: The present study demonstrates that regulation of RNA levels in articular cartilage during pregnancy is complex and is influenced by the parity and/or the skeletal maturity of the animals

Visible camera cryostat design and performance for the SuMIRe Prime Focus Spectrograph (PFS)

We describe the design and performance of the SuMIRe Prime Focus Spectrograph (PFS) visible camera cryostats. SuMIRe PFS is a massively multi-plexed ground-based spectrograph consisting of four identical spectrograph modules, each receiving roughly 600 fibers from a 2394 fiber robotic positioner at the prime focus. Each spectrograph module has three channels covering wavelength ranges 380~nm -- 640~nm, 640~nm -- 955~nm, and 955~nm -- 1.26~um, with the dispersed light being imaged in each channel by a f/1.07 vacuum Schmidt camera. The cameras are very large, having a clear aperture of 300~mm at the entrance window, and a mass of $\sim$280~kg. In this paper we describe the design of the visible camera cryostats and discuss various aspects of cryostat performance

An introduction to neonatal EEG

Electroencephalography (EEG) is used in neonatal care to assess encephalopathy, seizure recognition and classification, to make epilepsy syndrome diagnoses and to assess the maturity of neonatal brain activity. A basic understanding of the EEG is very helpful in ensuring that clinicians gain as much information as possible from this helpful, non-invasive investigation. The neonatal EEG is complex and accurate reporting requires detailed clinical information to be provided on request forms. Even when this is provided EEG reports are frequently returned to the neonatal unit loaded with technical details, making it difficult for neonatal staff to fully understand them. This article reviews the basics of EEG, the changes seen with increasing gestational age, and changes seen in common pathologies. We also provide a structured approach to the interpretation of the neonatal EEG report, and discuss its role in prognostication. Amplitude integrated EEG is reviewed in our companion paper

Modeling of pulsed laser guide stars for the Thirty Meter Telescope project

The Thirty Meter Telescope (TMT) has been designed to include an adaptive optics system and associated laser guide star (LGS) facility to correct for the image distortion due to Earth's atmospheric turbulence and achieve diffraction-limited imaging. We have calculated the response of mesospheric sodium atoms to a pulsed laser that has been proposed for use in the LGS facility, including modeling of the atomic physics, the light-atom interactions, and the effect of the geomagnetic field and atomic collisions. This particular pulsed laser format is shown to provide comparable photon return to a continuous-wave (cw) laser of the same average power; both the cw and pulsed lasers have the potential to satisfy the TMT design requirements for photon return flux.Comment: 16 pages, 20 figure

Hygienic behaviour in the Australian stingless bees Tetragonula carbonaria and T. hockingsi

Hygienic behaviour is a natural mechanism of colony-level disease resistance to brood pathogens and has been reported in honey bees and stingless bees. A novel brood disease was recently confirmed in the Australian stingless bees Tetragonula carbonaria Smith and Tetragonula hockingsi Cockerell and there is a paucity of data available on hygienic behaviour in these species. To address this, we investigated hygienic behaviour in eight colonies of T. carbonaria and four colonies of T. hockingsi, using brood freeze-kill and pin-kill assays. Hygienic behaviour was present in both species and was rapidly expressed in both assays. In T. carbonaria, the mean time (± SE) for removal of freeze-killed and pin-killed brood was 9.1 ± 1.9 hours and 8.2 ± 0.9 hours, respectively (n=8; one trial per assay). In T. hockingsi, removal of freeze-killed and pin-killed brood was 14.1 ± 5.1 hours and 10.4 (no SE) hours, respectively. There was no significant difference (α=0.05) in time taken to complete the hygienic behaviour phases (detection, uncapping, removal or cell dismantling) between assay type or assay order in both species. However, intercolony variation was observed in both species in the assays, suggesting that like honey bees, hygienic behaviour may have a genetic component. Tetragonula carbonaria and T. hockingsi displayed significantly faster detection, uncapping, removal and cell dismantling times than any of the stingless bees or most honey bees studied previously. This may, in part, explain why stingless bees appear to suffer from relatively few brood diseases

Artificial evolution of robot bodies and control: on the interaction between evolution, individual and cultural learning

We survey and reflect on evolutionary approaches to the joint optimisation of the body and control of a robot, in scenarios where a the goal is to find a design that maximises performance on a specified task. The review is grounded in a general framework for evolution which permits the interaction of evolution acting on a population with individual and cultural learning mechanisms. We discuss examples of variations of the general scheme of "evolution plus learning" from a broad range of robotic systems, and reflect on how the interaction of the two paradigms influences diversity, performance, and rate of improvement. Finally, we suggest a number of avenues for future work as result of the insights that arise from the review