Towards a unified model of stellar rotation II: Model-dependent characteristics of stellar populations

Rotation has a number of important effects on the evolution of stars. Apart from structural changes because of the centrifugal force, turbulent mixing and meridional circulation caused by rotation can dramatically affect a star's chemical evolution. This leads to changes in the surface temperature and luminosity as well as modifying its lifetime. Observationally rotation decreases the surface gravity, causes enhanced mass loss and leads to surface abundance anomalies of various chemical isotopes. The replication of these physical effects with simple stellar evolution models is very difficult and has resulted in the use of numerous different formulations to describe the physics. Using stellar evolution calculations based on several physical models we discuss the features of the resulting simulated stellar populations which can help to distinguish between the models.Comment: 14 pages, 13 figures. Accepted for publication in MNRA

Effect of IV alteplase on the ischemic brain lesion at 24-48 hours after ischemic stroke

OBJECTIVE: To determine whether alteplase alters the development of ischemic lesions on brain imaging after stroke. METHODS: The Third International Stroke Trial (IST-3) was a randomized controlled trial of IV alteplase for ischemic stroke. We assessed CT or brain MRI at baseline (pretreatment) and 24 to 48 hours posttreatment for acute lesion visibility, extent, and swelling, masked to all other data. We analyzed associations between treatment allocation, change in brain tissue appearances between baseline and follow-up imaging, and 6-month functional outcome in IST-3. We performed a meta-analysis of randomized trials of alteplase vs control with pre- and postrandomization imaging. RESULTS: Of 3,035 patients recruited in IST-3, 2,916 had baseline and follow-up brain imaging. Progression in either lesion extent or swelling independently predicted poorer 6-month outcome (adjusted odds ratio [OR] = 0.92, 95% confidence interval [CI] 0.88-0.96, p < 0.001; OR = 0.73, 95% CI 0.66-0.79, p < 0.001, respectively). Patients allocated alteplase were less likely than controls to develop increased lesion visibility at follow-up (OR = 0.77, 95% CI 0.67-0.89, p < 0.001), but there was no evidence that alteplase reduced progression of lesion extent or swelling. In meta-analysis of 6 trials including IST-3 (n = 4,757), allocation to alteplase was associated with a reduction in ischemic lesion extent on follow-up imaging (OR = 0.85, 95% CI 0.76-0.95, p = 0.004). CONCLUSION: Alteplase was associated with reduced short-term progression in lesion visibility. In meta-analysis, alteplase reduced lesion extent. These findings may indicate that alteplase improves functional outcome by reducing tissue damage. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that IV alteplase impedes the progression of ischemic brain lesions on imaging after stroke

Wide-field tracking with zenth-pointing telescopes

Equipped with a suitable optical relay system, telescopes employing low-cost fixed primary mirrors could point and track while delivering high-quality images to a fixed location. Such an optical tracking system would enable liquid-mirror telescopes to access a large area of sky and employ infrared detectors and adaptive optics. Such telescopes could also form the elements of an array in which light is combined either incoherently or interferometrically. Tracking of an extended field requires correction of all aberrations including distortion, field curvature and tilt. A specific design is developed that allows a 10-metre liquid-mirror telescope to track objects for as long as 30 minutes and to point as far as 4 degrees from the zenith, delivering a distortion-free diffraction-limited image to a stationary detector, spectrograph, or interferometric beam combiner.Comment: 8 pages, submitted to MNRA

A Detailed Investigation into Low-Level Feature Detection in Spectrogram Images

Being the first stage of analysis within an image, low-level feature detection is a crucial step in the image analysis process and, as such, deserves suitable attention. This paper presents a systematic investigation into low-level feature detection in spectrogram images. The result of which is the identification of frequency tracks. Analysis of the literature identifies different strategies for accomplishing low-level feature detection. Nevertheless, the advantages and disadvantages of each are not explicitly investigated. Three model-based detection strategies are outlined, each extracting an increasing amount of information from the spectrogram, and, through ROC analysis, it is shown that at increasing levels of extraction the detection rates increase. Nevertheless, further investigation suggests that model-based detection has a limitation—it is not computationally feasible to fully evaluate the model of even a simple sinusoidal track. Therefore, alternative approaches, such as dimensionality reduction, are investigated to reduce the complex search space. It is shown that, if carefully selected, these techniques can approach the detection rates of model-based strategies that perform the same level of information extraction. The implementations used to derive the results presented within this paper are available online from http://stdetect.googlecode.com

Shared Ageing Research Models (ShARM) : a new facility to support ageing research

In order to manage the rise in life expectancy and the concomitant increased occurrence of age-related diseases, research into ageing has become a strategic priority. Mouse models are commonly utilised as they share high homology with humans and show many similar signs and diseases of ageing. However, the time and cost needed to rear aged cohorts can limit research opportunities. Sharing of resources can provide an ethically and economically superior framework to overcome some of these issues but requires dedicated infrastructure. Shared Ageing Research Models (ShARM) (www.ShARMUK.org) is a new, not-for-profit organisation funded by Wellcome Trust, open to all investigators. It collects, stores and distributes flash frozen tissues from aged murine models through its biorepository and provides a database of live ageing mouse colonies available in the UK and abroad. It also has an online environment (MICEspace) for collation and analysis of data from communal models and discussion boards on subjects such as the welfare of ageing animals and common endpoints for intervention studies. Since launching in July 2012, thanks to the generosity of researchers in UK and Europe, ShARM has collected more than 2,500 tissues and has in excess of 2,000 mice registered in live ageing colonies. By providing the appropriate support, ShARM has been able to bring together the knowledge and experience of investigators in the UK and Europe to maximise research outputs with little additional cost and minimising animal use in order to facilitate progress in ageing research

Calcium-dependent in vitro interaction between bovine adrenal medullary cell membranes and chromaffin granules as a model for exocytosis

The new batch of Working Documents based on studies undertaken for CTA include an analysis of functional literacy (see Spore 88), and a set of two case studies on small-scale food processing of cassava and maize in Congo and Cameroon respectively. For those keen to sharpen their skills in evaluating the impact of agricultural information, a new Working Document provides a selective review of the issues and the relevant literature. Its illustrative case studies include the Caribbean and Botswana. Study on functional literacy programmes for agricultural and rural development in Ethiopia CTA, 2000. 106 pp. CTA number 8020. 5 credit points Approaches to impact evaluation (assessment) in agricultural information management CTA, 2000. 33 pp. CTA number 8021. 5 credit points Savoir-faire et réseaux de petites entreprises agroalimentaires en Afrique CTA, 2000. 68 pp. CTA number 8022. 5 credit pointsStudy on functional literacy programmes for agricultural and rural development in Ethiopi

The Unintended Consequences of a Ban on the Humane Slaughter (Processing) of Horses in the United States

Federal legislation has been proposed to amend the Horse Protection Act to prohibit the shipping, transporting, moving, delivering, receiving, possessing, purchasing, selling, or donation of horses and other equines to be humanely slaughtered (processed) for human consumption, and for other purposes. The intent of the legislation is to enact a ban in the United States on processing horses for human consumption. The legislation does not provide fiscal support that would likely be needed to respond to an ever increasing number of unwanted, neglected, and abused horses. Often times horse neglect and abuse cases originate from a lack of economic resources needed to adequately maintain a horse’s health. While everyone fully supports and is committed to the humane treatment of all horses, there are unintended consequences of banning horse processing. The purpose of this paper is to identify and review the unintended consequences of a ban in the United States on the processing of horses for human consumption: 1. The potential for a large number of abandoned or unwanted horses is substantial. 2. Public animal rescue facilities are currently saturated with unwanted horses. No funding has been allocated to manage a large increase in horses that will likely become the responsibility of these facilities. 3. Cost of maintaining unwanted horses accumulates over time: A conservative estimate of the total cost of caring for unwanted horses, based upon 2005 statistics, is $220 million; Cumulative annual maintenance costs of otherwise processed horses, since the year 2000, would have exceeded more than$513 million in 2005. 4. The export value of horse meat for human consumption was approximately $26 million. A ban on processing would eliminate these annual revenues. 5. The option of rendering equine carcasses is decreasing. Private-land burial and disposal in landfills have a negative impact on the environment. 6. The Bureau of Land Management’s Wild Horse and Burro Adoption Program may be negatively impacted by a ban on horse processing. BLM horses and an increasing number of unwanted horses will be competing for adoption homes. Horse processing facilities offer a humane end-of-life option for approximately 1% of the United States horse population. Tens of thousands of horses could be neglected or abandoned if a processing ban were imposed. The direct economic impact and future unintended–and currently unaccounted for–economic impact of banning horse processing for human consumption are substantial. Proponents have not addressed the inevitable costs of such a ban. Horse owners will realize a direct impact from lower horse sale prices. Local and state governments will be adversely impacted by increased costs of regulation and care of unwanted or neglected horses

Roadmaps to Utopia: Tales of the Smart City

Notions of the Smart City are pervasive in urban development discourses. Various frameworks for the development of smart cities, often conceptualized as roadmaps, make a number of implicit claims about how smart city projects proceed but the legitimacy of those claims is unclear. This paper begins to address this gap in knowledge. We explore the development of a smart transport application, MotionMap, in the context of a £16M smart city programme taking place in Milton Keynes, UK. We examine how the idealized smart city narrative was locally inflected, and discuss the differences between the narrative and the processes and outcomes observed in Milton Keynes. The research shows that the vision of data-driven efficiency outlined in the roadmaps is not universally compelling, and that different approaches to the sensing and optimization of urban flows have potential for empowering or disempowering different actors. Roadmaps tend to emphasize the importance of delivering quick practical results. However, the benefits observed in Milton Keynes did not come from quick technical fixes but from a smart city narrative that reinforced existing city branding, mobilizing a growing network of actors towards the development of a smart region. Further research is needed to investigate this and other smart city developments, the significance of different smart city narratives, and how power relationships are reinforced and constructed through them