Dwarf Galaxies in Clusters as Probes of Galaxy Formation and Dark Matter

We present the results of a Hubble Space Telescope (HST) ACS and WFPC2 study of dwarf galaxies in the nearby Perseus Cluster, down to M_V = -12, spanning the core and outer regions of this cluster. We examine how properties such as the colour magnitude relation, structure and morphology are affected by environment for the lowest mass galaxies. The low masses of dwarf galaxies allow us to determine their environmentally driven based galaxy evolution, the effects of which are harder to examine in massive galaxies. The structures of our dwarfs in both the core and outer regions of the cluster are quantified using the concentration, asymmetry and clumpiness (CAS) parameters. We find that, on average, dwarfs in the outer regions of Perseus are more disturbed than those in the cluster core, with higher asymmetries and clumpier light distributions. We measure the (V-I)_0 colours of the dEs, and find that dwarfs in both the inner and outer regions of the cluster lie on the same colour magnitude relation. Based on these results, we infer that the disturbed dwarfs in the cluster outskirts are likely "transition dwarfs", with their colours transforming before their structures. Finally, we infer from the smoothness of the cluster core population that dwarfs in the inner regions of the cluster must be highly dark matter dominated to prevent their disruption by the cluster potential. We derive a new method to determine the minimum mass the dwarfs must have to prevent this disruption without the need for resolved spectroscopy, and determine their mass-to-light ratios. At their orbit pericentre, dwarfs in the core of Perseus require mass-to-light ratios between 1 and 120 to prevent their disruption, comparable to those found for the Local Group dSphs.Comment: 6 pages, 5 figures. To appear in the proceedings of "A Universe of dwarf galaxies" (Lyon, June 14-18 2010

Modelling the Requirements and Benefits of Mosquito Control Interventions in the Presence of Mosquito Dispersal

Vector control methods are widely used as a means to control malaria, however, the role of spatial arrangement when deploying these interventions is not well known. Understanding the effects of spatial distribution and clustering of interventions on mosquito populations can provide a guide to strategically deploying interventions to effectively maximize benefits. A recently developed discrete-space continuous-time mathematical model of mosquito population dynamics and dispersal was extended to incorporate vector control interventions of insecticide residual spraying (IRS), larviciding and insecticide treated bednets (ITNs). Model simulations were used to determine intervention deployment strategies, for certain coverage levels, which maximize the benefits of interventions. Assuming homogeneous distribution of water resources and humans, then clustering of IRS and larviciding interventions, when only low coverage is possible, is more beneficial than random deployment. However, with moderate coverage of these interventions, there is no added benefit with clustering compared to random deployment. For low coverage of ITNs, clustering their distribution lowers the\ud benefits. Surprisingly, with moderate coverage of ITNs then random deployment of ITNs to humans is more beneficial than clustering. There is evidence that the effectiveness of an intervention is highly dependent on its spatial distribution. Although the results presented here are based on model\ud assumptions, the findings are useful to consider when designing modes of deployment of interventions to offer maximal benefits.\u

Research knowledge and skills in primary medical training: A crosssectional audit

This article was migrated. The article was marked as recommended. Background: Internationally, medical education has either adopted, or is moving toward, a Masters level qualification at completion. This reflects the higher-level learning outcomes and potentially facilitation of thinking and decision-making required of medical graduates. In Australia, the main difference between bachelor and masters programs appears to be the level of research skills training. This study explores the characteristics of research training in medical schools and alignment with higher education qualification frameworks. Methods: A cross-sectional audit was conducted of 22 medical schools in Australia and New Zealand, seeking information on: degree type, entry requirement, research knowledge and skills taught, teaching format, and barriers to offering students research experiences. Results: Information about 15 medical programs was obtained, with Australian Qualifications Framework or New Zealand Qualifications Framework Level 7, 8 or 9E outcomes. All included a variety of teaching methods on biomedical ethics, principles of evidence-based practice, and search strategies for medical evidence, critical appraisal of the literature and disease surveillance/epidemiology. Small projects were available in all programs, although voluntary in Level 7/8 programs and mandatory in Level 9E programs. Conclusions: There appear to be few differences in research training and learning outcomes from Level 7 and Level 9E programs, although Level 9E programs have a more systematic approach and assurance that all graduates can achieve the higher outcomes. Barriers to successful implementation relate to finding curriculum space and sufficient research training capacity for all medical students.</ns4:p

Improving case study research in medical education: A systematised review

Context:Case study research (CSR) is a research approach that guides holistic investigation of a real phenomenon. This approach may be useful in medical education to provide critical analyses of teaching and learning, and to reveal the underlying elements of leadership and innovation. There are variations in the definition, design and choice of methods, which may diminish the value of CSR as a form of inquiry.Objectives:This paper reports an analysis of CSR papers in the medical education literature. The review aims to describe how CSR has been used and how more consistency might be achieved to promote understanding and value.Methods:A systematised review was undertaken to quantify the number of CSR articles published in scholarly medical education journals over the last 10 years. A typology of CSR proposed by Thomas and Myers to integrate the various ways in which CSR is constructed was applied.Results:Of the 362 full‐text articles assessed, 290 were excluded as they did not meet the eligibility criteria; 76 of these were titled ‘case study’. Of the 72 included articles, 50 used single‐case and 22 multi‐case design; 46 connected with theory and 26 were atheoretical. In some articles it was unclear what the subject was or how the subject was being analysed.Conclusions:In this study, more articles titled ‘case study’ failed than succeeded in meeting the eligibility criteria. Well‐structured, clearly written CSR in medical education has the potential to increase understanding of more complex situations, but this review shows there is considerable variation in how it is conducted, which potentially limits its utility and translation into education practice. Case study research might be of more value in medical education if researchers were to follow more consistently principles of design, and harness rich observation with connection of ideas and knowledge to engage the reader in what is most interesting

Planned Change in Higher Education: A Case Study of the NASSP Alliance for Developing School Leaders

The problem was that much effort was being put into an alliance for preparing school leaders with little evidence concerning how effective such groups were in promoting positive change. The purpose of this study was to provide a historical background for the National Alliance for Developing School Leaders that included the rationale for the endeavor, the identification of key actors and their roles, and perceived changes resulting from Alliance affiliation. The information gleaned from the study was intended to answer the formulated research questions. Data were collected using semi-structured interviews and through examination of relevant documents. Data were coded and clustered to assist with the organization of a plethora of information. The information was then used to tell the story of the National Alliance for Developing School Leaders as told by those directly involved in the conception and development of the Alliance. Evidence indicated that change had occurred as a result of the National Alliance for Developing School Leaders, however, the degree of change experienced varied across university sites. Conclusions drawn indicated that the Alliance provided faculty and students exposure to new materials and teaching techniques, opportunities for increased presentations and publications, higher visibility, professional development opportunities that included area school administrators, and increased professional dialogue regarding changes needed in administrator preparation programs. Evidence existed that more on-site visits and opportunities to dialogue about the successes of each program as well as the difficulties encountered by the universities attempting to change their preparation programs were desired by Alliance participants. Participants reflected on their experiences resulting from involvement with the National Alliance for Developing School Leaders and then shared insights regarding essentials necessary for successful multiorganizational collaborative efforts

Rocket exhaust plume computer program improvement. Volume 1: Summary: Method of characteristics nozzle and plume programs

A summary is presented of the various documents that discuss and describe the computer programs and analysis techniques which are available for rocket nozzle and exhaust plume calculations. The basic method of characteristics program is discussed, along with such auxiliary programs as the plume impingement program, the plot program and the thermochemical properties program

Space shuttle SRM plume expansion sensitivity analysis

The exhaust plumes of the space shuttle solid rocket motors can have a significant effect on the base pressure and base drag of the shuttle vehicle. A parametric analysis was conducted to assess the sensitivity of the initial plume expansion angle of analytical solid rocket motor flow fields to various analytical input parameters and operating conditions. The results of the analysis are presented and conclusions reached regarding the sensitivity of the initial plume expansion angle to each parameter investigated. Operating conditions parametrically varied were chamber pressure, nozzle inlet angle, nozzle throat radius of curvature ratio and propellant particle loading. Empirical particle parameters investigated were mean size, local drag coefficient and local heat transfer coefficient. Sensitivity of the initial plume expansion angle to gas thermochemistry model and local drag coefficient model assumptions were determined

Counting the costs of crime in Australia: a 2011 estimate

This report estimates the costs of crime for the calendar year 2011. Executive summary This report seeks to estimate how much crime costs the Australian economy by calculating the number of crimes that come to the attention of the authorities and, using crime victimisation survey data, the number of crimes that are not recorded officially. A dollar figure is then calculated for each estimated crime event and an indication given of the total cost of each specific crime type in terms of actual loss, intangible losses, loss of output caused through the criminal conduct and other related costs such as medical expenses, where relevant. Added to these costs are the costs of preventing and responding to crime in the community including the costs of maintaining the criminal justice system agencies of police, prosecution, courts and correctional agencies, as well as a proportion of the costs of Australian and state and territory government agencies that have crime-related functions. Finally, a deduction is made for the value of property recovered in the case of property crime, as well as the amount of funds recovered from criminals under federal, state and territory proceeds of crime legislation. More detailed information about how each of these estimates was derived is provided in the main body of the report. Official attention paid to specific crime types, particularly drug-related crime and organised crime, affects both the reporting rate and also the cost of policing and correctional responses. In this sense, individual crime type costs and prevention and response costs are not mutually exclusive. Arguably, as individual crime types attract more attention, reporting rates increase and prevention and control of the crimes in question are seen as being deserving of increased resource