Rotor redesign for a highly loaded 1800 ft/sec tip speed fan. 3: Laser Doppler velocimeter report

Laser Doppler velocimeter (LDV) techniques were employed for testing a highly loaded, 550 m/sec (1800 ft/sec) tip speed, test fan stage, the objective to provide detailed mapping of the upstream, intrablade, and downstream flowfields of the rotor. Intrablade LDV measurements of velocity and flow angle were obtained along four streamlines passing through the leading edge at 45%, 69%, 85%, and 95% span measured from hub to tip, at 100% of design speed, peak efficiency; 100% speed, near surge; and 95% speed, peak efficiency. At the design point, most passages appeared to have a strong leading edge shock, which moved forward with increasing strength near surge and at part speeds. The flow behind the shock was of a complex mixed subsonic and supersonic form. The intrablade flowfields were found to be significantly nonperiodic at 100% design speed, peak efficiency

Search for a Radio Pulsar in the Remnant of Supernova 1987A

We have observed the remnant of supernova SN~1987A (SNR~1987A), located in the Large Magellanic Cloud (LMC), to search for periodic and/or transient radio emission with the Parkes 64\,m-diameter radio telescope. We found no evidence of a radio pulsar in our periodicity search and derived 8$\sigma$ upper bounds on the flux density of any such source of $31\,\mu$Jy at 1.4~GHz and $21\,\mu$Jy at 3~GHz. Four candidate transient events were detected with greater than $7\sigma$ significance, with dispersion measures (DMs) in the range 150 to 840\,cm$^{-3}\,$pc. For two of them, we found a second pulse at slightly lower significance. However, we cannot at present conclude that any of these are associated with a pulsar in SNR~1987A. As a check on the system, we also observed PSR~B0540$-$69, a young pulsar which also lies in the LMC. We found eight giant pulses at the DM of this pulsar. We discuss the implications of these results for models of the supernova remnant, neutron star formation and pulsar evolution.Comment: 7 pages, 3 figures, 2 tables. Accepted for publication in MNRA

Beyond evidence: reappraising use of CA-125 as post-therapy surveillance for ovarian cancer

omen who have completed primary chemotherapy for ovarian cancer commonly have serial assessment of the serum tumour marker cancer antigen 125 (CA-125).1 This practice has been based on the proven utility of CA-125 in diagnostic algorithms and as a marker of response to therapy. Serial CA-125 assessment is also used because there is evidence that in women who have completed treatment for ovarian cancer, the serum CA-125 rises 2–6 months before symptoms or signs of relapse develop. The assumption underlying this and other similar studies is that serial monitoring of CA-125 would enable early diagnosis and treatment of relapse. This would thus lead to delay or reduction of cancer-related symptoms, psychological reassurance and, in theory, improved survival. Some studies have suggested that CA-125 may have some benefit in post-treatment surveillance. However, many others have demonstrated that although a rising CA-125 level is highly predictive of relapse, surveillance monitoring of CA-125 levels after remission from primary chemotherapy confers little benefit over standard clinical examination and does not improve duration of survival or quality of life

Cancergazing? CA125 and post-treatment surveillance in advanced ovarian cancer.

Post-treatment surveillance of advanced ovarian cancer involves regular testing of asymptomatic patients using the CA125 test. This practice is based on a rationale that is not supported by evidence from clinical trials. This paper aims to stimulate critical reflection concerning the effect of investigative tests on clinical decisions and interactions, and the experience of illness, particularly in the context of advanced malignant disease. Drawing on the idea of the “medical gaze”, and building on previous health communication research, we present an analysis of in-depth interviews and psychometric tests collected in a prospective study of 20 Australian women with advanced ovarian cancer conducted between 2006 and 2009. We describe the demands placed on patients by the use of the CA125 test, some hazards it creates for decision-making, and some of the test’s subjective benefits. It is widely believed that the CA125 test generates anxiety among patients, and the proposed solution is to educate women more about the test. We found no evidence that anxiety was a problem requiring a response over and above existing services. We conclude that the current debate is simplistic and limited. Focussing on patient anxiety does not account for other important effects of post-treatment surveillance, and educating patients about the test is unlikely to mitigate anxiety because testing is part of a wider process by which patients become aware of a disease that – once it has relapsed – will certainly kill them in the near future.National Health and Medical Research Council Project Grant number 40260

The perils of a vanishing cohort: A study of social comparisons by women with advanced ovarian cancer

Objective: To examine the role social comparisons play in the experience of ovarian cancer patients and to consider the implications this may have for provision of supportive care services for ovarian cancer patients. Methods: We conducted a longitudinal qualitative study of women with advanced ovarian cancer in Sydney, Australia. Semi-structured interviews were conducted with women with advanced ovarian cancer over a period of 2.5 years. Social comparisons made by 13 study participants in 33 interviews were extracted and analysed using coding categories based on social comparison theory. Results: Participants favoured downward contrasts and lateral comparisons and avoided downward identifications, upward contrasts and upward identifications. Participants expressed a preference for avoiding contact with ovarian cancer patients, for the company of “normal” others, for normalizing information and information that facilitated upward identifications. Conclusions: We suggest that social comparisons made by women with ovarian cancer are influenced by specific clinical factors associated with their diagnosis – in particular their status as a member of a “vanishing cohort” – and argue for further research examining the specific comparison needs and preferences of patients with advanced disease and types of cancer with poor prognoses. Practice implications: These findings raise questions about uniform approaches to the provision of cancer care and suggest that further research may be required to ensure that interventions are appropriately tailored to the supportive care needs of patients with different types and stages of disease. KEYWORDS Cancer; Oncology; Ovarian neoplasms; Social comparison theory; Social support; Self-help groupsNational Health & Medical Research Council Project Grant 40260

Agent-based homeostatic control for green energy in the smart grid

With dwindling non-renewable energy reserves and the adverse effects of climate change, the development of the smart electricity grid is seen as key to solving global energy security issues and to reducing carbon emissions. In this respect, there is a growing need to integrate renewable (or green) energy sources in the grid. However, the intermittency of these energy sources requires that demand must also be made more responsive to changes in supply, and a number of smart grid technologies are being developed, such as high-capacity batteries and smart meters for the home, to enable consumers to be more responsive to conditions on the grid in real-time. Traditional solutions based on these technologies, however, tend to ignore the fact that individual consumers will behave in such a way that best satisfies their own preferences to use or store energy (as opposed to that of the supplier or the grid operator). Hence, in practice, it is unclear how these solutions will cope with large numbers of consumers using their devices in this way. Against this background, in this paper, we develop novel control mechanisms based on the use of autonomous agents to better incorporate consumer preferences in managing demand. These agents, residing on consumers' smart meters, can both communicate with the grid and optimise their owner's energy consumption to satisfy their preferences. More specifically, we provide a novel control mechanism that models and controls a system comprising of a green energy supplier operating within the grid and a number of individual homes (each possibly owning a storage device). This control mechanism is based on the concept of homeostasis whereby control signals are sent to individual components of a system, based on their continuous feedback, in order to change their state so that the system may reach a stable equilibrium. Thus, we define a new carbon-based pricing mechanism for this green energy supplier that takes advantage of carbon-intensity signals available on the internet in order to provide real-time pricing. The pricing scheme is designed in such a way that it can be readily implemented using existing communication technologies and is easily understandable by consumers. Building upon this, we develop new control signals that the supplier can use to incentivise agents to shift demand (using their storage device) to times when green energy is available. Moreover, we show how these signals can be adapted according to changes in supply and to various degrees of penetration of storage in the system. We empirically evaluate our system and show that, when all homes are equipped with storage devices, the supplier can significantly reduce its reliance on other carbon-emitting power sources to cater for its own shortfalls. By so doing, the supplier reduces the carbon emission of the system by up to 25% while the consumer reduces its costs by up to 14.5%. Finally, we demonstrate that our homeostatic control mechanism is not sensitive to small prediction errors and the supplier is incentivised to accurately predict its green production to minimise costs

Beyond evidence: reappraising use of CA-125 as post-therapy surveillance for ovarian cancer

omen who have completed primary chemotherapy for ovarian cancer commonly have serial assessment of the serum tumour marker cancer antigen 125 (CA-125).1 This practice has been based on the proven utility of CA-125 in diagnostic algorithms and as a marker of response to therapy. Serial CA-125 assessment is also used because there is evidence that in women who have completed treatment for ovarian cancer, the serum CA-125 rises 2–6 months before symptoms or signs of relapse develop. The assumption underlying this and other similar studies is that serial monitoring of CA-125 would enable early diagnosis and treatment of relapse. This would thus lead to delay or reduction of cancer-related symptoms, psychological reassurance and, in theory, improved survival. Some studies have suggested that CA-125 may have some benefit in post-treatment surveillance. However, many others have demonstrated that although a rising CA-125 level is highly predictive of relapse, surveillance monitoring of CA-125 levels after remission from primary chemotherapy confers little benefit over standard clinical examination and does not improve duration of survival or quality of life

Farmers' management of rice varietal diversity in the mid-hills of Nepal: implications for on-farm conservation and crop improvement

Season-long monitoring of on-farm rice (Oryza sativa, L.) plots in Nepal explored farmers' decision-making process on the deployment of varieties to agroecosystems, application of production inputs to varieties, agronomic practices and relationship between economic return and area planted per variety. Farmers deploy varieties [landraces (LRs) and modern varieties (MVs)] to agroecosystems based on their understanding of characteristics of varieties and agroecosystems, and the interaction between them. In marginal growing conditions, LRs can compete with MVs. Within an agroecosystem, economic return and area planted to varieties have positive relationship, but this is not so between agroecosystems. LRs are very diverse on agronomic and economic traits; therefore, they cannot be rejected a priori as inferior materials without proper evaluation. LRs have to be evaluated for useful traits and utilized in breeding programmes to generate farmer-preferred materials for marginal environments and for their conservation on-farm

A hierarchical Bayesian approach for handling missing classification data

Ecologists use classifications of individuals in categories to understand composition of populations and communities. These categories might be defined by demo- graphics, functional traits, or species. Assignment of categories is often imperfect, but frequently treated as observations without error. When individuals are observed but not classified, these “partial” observations must be modified to include the missing data mechanism to avoid spurious inference. We developed two hierarchical Bayesian models to overcome the assumption of perfect assignment to mutually exclusive categories in the multinomial distribu- tion of categorical counts, when classifications are missing. These models incorporate auxiliary information to adjust the posterior distributions of the proportions of membership in categories. In one model, we use an empirical Bayes approach, where a subset of data from one year serves as a prior for the missing data the next. In the other approach, we use a small random sample of data within a year to inform the distribution of the missing data. We performed a simulation to show the bias that occurs when partial observations were ignored and demonstrated the altered inference for the estimation of demographic ratios. We applied our models to demographic classifications of elk (Cervus elaphus nelsoni) to demonstrate improved inference for the proportions of sex and stage classes. We developed multiple modeling approaches using a generalizable nested multi- nomial structure to account for partially observed data that were missing not at random for classification counts. Accounting for classification uncertainty is important to accurately understand the composition of populations and communities in ecological studies