Super-orbital re-entry in Australia - laboratory measurement, simulation and flight observation

There are large uncertainties in the aerothermodynamic modelling of super-orbital re-entry which impact the design of spacecraft thermal protection systems (TPS). Aspects of the thermal environment of super-orbital re-entry flows can be simulated in the laboratory using arc- and plasma jet facilities and these devices are regularly used for TPS certification work [5]. Another laboratory device which is capable of simulating certain critical features of both the aero and thermal environment of super-orbital re-entry is the expansion tube, and three such facilities have been operating at the University of Queensland in recent years[10]. Despite some success, wind tunnel tests do not achieve full simulation, however, a virtually complete physical simulation of particular re-entry conditions can be obtained from dedicated flight testing, and the Apollo era FIRE II flight experiment [2] is the premier example which still forms an important benchmark for modern simulations. Dedicated super-orbital flight testing is generally considered too expensive today, and there is a reluctance to incorporate substantial instrumentation for aerothermal diagnostics into existing missions since it may compromise primary mission objectives. An alternative approach to on-board flight measurements, with demonstrated success particularly in the ‘Stardust’ sample return mission, is remote observation of spectral emissions from the capsule and shock layer [8]. JAXA’s ‘Hayabusa’ sample return capsule provides a recent super-orbital reentry example through which we illustrate contributions in three areas: (1) physical simulation of super-orbital re-entry conditions in the laboratory; (2) computational simulation of such flows; and (3) remote acquisition of optical emissions from a super-orbital re entry event

Exploring the association between recent concussion, subconcussive impacts and depressive symptoms in male Australian Football players

Objectives: To explore the association between depressive symptoms and recent head-related trauma (diagnosed concussion, subconcussive impacts) in semiprofessional male Australian Football (AF) players. Methods: Sixty-nine semiprofessional male players from a West Australian Football League (WAFL) club participated in the study (M age =21.81, SD=2.91 years). Depressive symptoms were measured using the Centre for Epidemiological Studies Depression Scale. Injuries and potential confounding variables (eg, pre-existing mental health condition; alcohol or drug hangovers; experiencing a stressful event) were self-reported anonymously using the WAFL Injury Report Survey. Both tools were administered every 2-weeks over the first 22-weeks of the WAFL season. Controlling for potential confounding variables and other injuries, a repeated measures generalised estimating equations model assessed the risk of clinically relevant depressive symptoms occurring, when diagnosed concussion or subconcussive impacts were experienced. Results: A total of 10 concussions and 183 subconcussive impacts were reported. Players who experienced a concussion were almost nine times more likely to experience clinically relevant depressive symptoms (OR 8.88, 95% CI 2.65 to 29.77, p \u3c 0.001). Although elevated, depressive symptoms following subconcussive impacts were not statistically significant (OR 1.13, 95% CI 0.67 to 1.92, p = 0.641). Conclusion: These findings indicate that semiprofessional AF athletes may be at risk of experiencing depressive symptoms after concussion. Severity (concussion vs subconcussive impacts) and dose (number of impacts) appear to have an important relationship with depressive symptom outcomes in this cohort and should be considered for further research and management of player welfare. © Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ

Species Traits Predict Assemblage Dynamics at Ephemeral Resource Patches Created by Carrion

Carrion is an ephemeral and spatially patchy resource that supports a diverse subset of species linked to nutrient cycling and the decomposition process. A number of studies have separately documented changes in the diversity of plants, arthropods and vertebrates at individual carcasses, but there are few studies that have examined how functional traits of different groups of organisms underpin their responses to carrion patches. We used a carrion addition experiment to compare changes in composition and functional traits of insect and plant assemblages at carcasses compared with control sites. We found that significant changes in insect assemblage evenness and heterogeneity was associated with species' dispersal traits, and that plant assemblage responses to subsequent soil nitrogen changes was most apparent among graminoids and exotic species. Beetles at carcasses were twice as large as their counterparts at control sites during the first week of carrion decomposition, and also had higher wing loadings. Plants with high specific leaf area responded faster to the carcass addition, and twice as many species recolonised the centre of carcasses in exotic-dominated grassland compared with carcasses in native-dominated grassland. These results provide an example of how traits of opportunist species enable them to exploit patchy and dynamic resources. This increases our understanding of how carcasses can drive biodiversity dynamics, and has implications for the way carrion might be managed in ecosystems, such as appropriate consideration of spatial and temporal continuity in carrion resources to promote heterogeneity in nutrient cycling and species diversity within landscapes.This research was supported by the Mulligans Flat – Goorooyarroo Woodland Experiment (Australian Research Council Linkage Grants LP0561817 and LP110100126). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Science and Its Discontents: Is There an End to Knowing?

Is there an end to our scientific quest? This question that continues to divide the scientific community between those who believe that the progress of science is infinite and those who think that we already understand how the universe works and no major discoveries are to be expected in the future. This article explores the philosophical worldview of modern science that has given rise to this question. It argues that an approach to knowledge that focuses on the process of construction of knowledge rather than its products offers a possibility of definitively answering this question and opening paths for a more rational approach in advancing and managing the scientific progress

Does a neutral thermal sensation determine thermal comfort?

The neutral thermal sensation (neither cold, nor hot) is widely used through the application of the ASHRAE seven-point thermal sensation scale to assess thermal comfort. This study investigated the application of the neutral thermal sensation and it questions the reliability of any study that solely relies on neutral thermal sensation. Although thermal-neutrality has already been questioned, still most thermal comfort studies only use this measure to assess thermal comfort of the occupants. In this study, the connection of the occupant’s thermal comfort with thermal-neutrality was investigated in two separate contexts of Norwegian and British offices. Overall, the thermal environment of four office buildings was evaluated and 313 responses (three times a day) to thermal sensation, thermal preference, comfort, and satisfaction were recorded. The results suggested that 36% of the occupants did not want to feel neutral and they considered thermal sensations other than neutral as their comfort condition. Also, in order to feel comfortable, respondents reported wanting to feel different thermal sensations at different times of the day suggesting that occupant desire for thermal comfort conditions may not be as steady as anticipated. This study recommends that other measures are required to assess human thermal comfort, such as thermal preference

Antibiotic use in acute pancreatitis : an audit of current practice in a tertiary centre

Introduction: Intravenous antibiotic prophylaxis is not recommended in acute pancreatitis. According to current international guidelines antibiotics together with further intervention should be considered in the setting of infected necrosis. Appropriate antibiotic therapy particularly avoiding over-prescription is important. This study examines antibiotic use in acute pancreatitis in a tertiary centre using the current IAP/APA guidelines for reference. Methods: Data were collected on a consecutive series of patients admitted with acute pancreatitis over a 12 month period. Data were dichotomized by patients admitted directly to the centre and tertiary transfers. Information was collected on clinical course with specific reference to antibiotic use, episode severity, intervention and outcome. Results: 111 consecutive episodes of acute pancreatitis constitute the reported population. 31 (28%) were tertiary transfers. Overall 65 (58.5%) patients received antibiotics. Significantly more tertiary transfer patients received antibiotics. Mean person-days of antibiotic use was 23.9 (sd 29.7) days in the overall study group but there was significantly more use in the tertiary transfer group as compared to patients having their index admission to the centre (40.9 sd 37.1 vs 10.2 sd 8.9; P < 0.005). Thirty four (44%) of patients with clinically mild acute pancreatitis received antibiotics. Conclusions: There is substantial use of antibiotics in acute pancreatitis, in particular in patients with severe disease. Over-use is seen in mild acute pancreatitis. Better consideration must be given to identification of prophylaxis or therapy as indication. In relation to repeated courses of antibiotics in severe disease there must be clear indications for use

Effects of digging by a native and introduced ecosystem engineer on soil physical and chemical properties in temperate grassy woodland

Temperate grasslands and woodlands are the focus of extensive restoration efforts worldwide. Reintroduction of locally extinct soil-foraging and burrowing animals has been suggested as a means to restore soil function in these ecosystems. Yet little is known about the physical and chemical effects of digging on soil over time and how these effects differ between species of digging animal, vegetation types or ecosystems. We compared foraging pits of a native reintroduced marsupial, the eastern bettong (Bettongia gaimardi) and that of the exotic European rabbit (Oryctolagus cuniculus). We simulated pits of these animals and measured pit dimensions and soil chemical properties over a period of 2 years. We showed that bettong and rabbit pits differed in their morphology and longevity, and that pits had a strong moderating effect on soil surface temperatures. Over 75% of the simulated pits were still visible after 2 years, and bettong pits infilled faster than rabbit pits. Bettong pits reduced diurnal temperature range by up to 25 C compared to the soil surface. We did not find any effects of digging on soil chemistry that were consistent across vegetation types, between bettong and rabbit pits, and with time since digging, which is contrary to studies conducted in arid biomes. Our findings show that animal foraging pits in temperate ecosystems cause physical alteration of the soil surface and microclimatic conditions rather than nutrient changes often observed in arid areas.This work was supported by an Australian Research Council Linkage Grant (LP0561817, LP110100126, LP140100209). Catherine Ross was supported by an Australian Government Research Training Program (RTP) Scholarship, and an additional scholarship top-up from the ARC (LP140100209)

Respiratory pandemics, urban planning and design: a multidisciplinary rapid review of the literature.

COVID-19 is the most recent respiratory pandemic to necessitate better knowledge about city planning and design. The complex connections between cities and pandemics, however challenge traditional approaches to reviewing literature. In this article we adopted a rapid review methodology. We review the historical literature on respiratory pandemics and their documented connections to urban planning and design (both broadly defined as being concerned with cities as complex systems). Our systematic search across multidisciplinary databases returned a total of 1323 sources, with 92 articles included in the final review. Findings showed that the literature represents the multi-scalar nature of cities and pandemics – pandemics are global phenomena spread through an interconnected world, but require regional, city, local and individual responses. We characterise the literature under ten themes: scale (global to local); built environment; governance; modelling; non-pharmaceutical interventions; socioeconomic factors; system preparedness; system responses; underserved and vulnerable populations; and future-proofing urban planning and design. We conclude that the historical literature captures how city planning and design intersects with a public health response to respiratory pandemics. Our thematic framework provides parameters for future research and policy responses to the varied connections between cities and respiratory pandemics

Fraser of Allander Institute : Economic Commentary [March 2022]

Two years on from the first lockdown, it would be great to be optimistic about the economic prospects for 2022. Unfortunately, global uncertainties and the cost of living crisis, which are not unrelated to each other, have doused that enthusiasm with a bucket of cold water. The war in Ukraine is first and foremost a humanitarian disaster. This crisis though also has implications for the costs of goods and services in our country. Having said this, it is important to remember that inflationary pressures were evident well before this, with post-pandemic supply chain issues and world-wide demand for gas causing prices to rise. Despite the impact of Omicron in December, the economy is now (as of data in January) back above pre-pandemic levels of growth. This milestone in the recovery is of course important: but seems less heartening than it might have done a few months ago given the wider economic conditions. Needless to say, the macro picture for the economy hides a disparate sectoral story. The hospitality, arts, leisure and culture and “other services” sectors remain significantly below pre-pandemic levels of output. Other services covers businesses like hairdressers and beauticians which have been heavily impacted by restrictions. These sectors may suffer further as consumers cut back discretionary spending as the cost of living crisis really starts to bite. The resilience of these businesses is likely to be tested yet again. With all this in mind, we have downgraded our forecast for 2022. We are now forecasting growth of 3.5% in 2022, 1.5% in 2023, and 1.4% in 2024. Our forecast for 2022 has been downgraded from 4.7% in our previous commentary. Of course – forecasting right now is hugely uncertain, and our view on the outlook for the economy is likely to evolve as the geopolitical and economic situation evolves over the next few months. The Spring Statement last week was unveiled as a package to support households and businesses through the cost of living crisis. However, it is likely that the measures will be little help to those on the lowest incomes, particularly benefit recipients, when the real-terms value of the money they are receiving is being eroded by inflation. As well as analysis of all of the latest data on the economy, in this edition of the commentary we analyse the new forecasts and announcements released last week. We also have a special focus on the impact on businesses of price rises, and a deep dive analysis into the rise in inactivity in the labour market. Finally, we produce an analysis of all things local government, to set the scene for the local government elections in May. While it is easy to be distracted by the global and economic issues affecting us all at both a macro and personal level, we set out the key issues which are likely to inform this debate in the run up to 5th May