Mathematical modelling and numerical simulation of phosphine flow during grain fumigation in leaky cylindrical silos

The phosphine distribution in a cylindrical silo containing grain is predicted. A three-dimensional mathematical model, which accounts for multicomponent gas phase transport and the sorption of phosphine into the grain kernel is developed. In addition, a simple model is presented to describe the death of insects within the grain as a function of their exposure to phosphine gas. The proposed model is solved using the commercially available computational fluid dynamics (CFD) software, FLUENT, together with our own C code to customize the solver in order to incorporate the models for sorption and insect extinction. Two types of fumigation delivery are studied, namely, fan- forced from the base of the silo and tablet from the top of the silo. An analysis of the predicted phosphine distribution shows that during fan forced fumigation, the position of the leaky area is very important to the development of the gas flow field and the phosphine distribution in the silo. If the leak is in the lower section of the silo, insects that exist near the top of the silo may not be eradicated. However, the position of a leak does not affect phosphine distribution during tablet fumigation. For such fumigation in a typical silo configuration, phosphine concentrations remain low near the base of the silo. Furthermore, we find that half-life pressure test readings are not an indicator of phosphine distribution during tablet fumigation.

The PerCues framework and its application for sustainable mobility

This paper presents a framework, design and study of an ambient persuasive interface. We introduce a novel framework of persua sive Cues in Ambient Intelligence (perCues). Based on this framework we designed an application for mobile devices. The application aims to persuade people to abstain from using their cars and to use public mass transportation instead in order to reduce emissions. It contains a bus schedule and information about the pollution status. We evaluated the application in two successive studies regarding user acceptance, oppor tune moments of use and persuasive effects. The perCues received a high acceptance due to its benefit for the users. The results confirm the im portance of opportune moment and user acceptance for persuasion. The findings also indicate the persuasive potential of perCues.

Mobility impairment and bad feet … who'd of guessed? The Foot Disease in Inpatients Study (FDIS)

Background Foot complications have been found to be predictors of mobility impairment and falls in community dwelling elderly patients. However, fewer studies have investigated the link between foot complications and mobility impairment in hospital in patient populations. The aim of this paper was to investigate the associations between mobility impairment and various foot complications in general inpatient populations. Methods Eligible participants were all adults admitted overnight, for any reason, into five diverse hospitals on one day; excluding maternity, mental health and cognitively impaired patients. Participants underwent a foot examination to clinically diagnose different foot complications; including foot wounds, infections, deformity, peripheral arterial disease and peripheral neuropathy. They were also surveyed on social determinant, medical history, self-care, footwear, foot complication history risk factors, and, mobility impairment defined as requiring a mobility aid for mobilisation prior to hospitalisation. Results Overall, 733 participants consented; mean(±SD) age 62(±19) years, 408 (55.8%) male, 172 (23.5%) diabetes. Mobility impairment was present in 242 (33.2%) participants; diabetes populations reported more mobility impairment than non-diabetes populations (40.7% vs 30.9%, p < 0.05). In a backwards stepwise multivariate analysis, and controlling for other risk factors, those people with mobility impairment were independently associated with increasing years of age (OR = 1.04 (95% CI) (1.02-1.05)), male gender (OR = 1.7 (1.2-2.5)), being born in Australia (OR = 1.7 (1.1-2.8), vision impairment (2.0 (1.2-3.1)), peripheral neuropathy (OR = 3.1 (2.0-4.6) and foot deformity (OR = 2.0 (1.3-3.0). Conclusions These findings support the results of other large studies investigating community dwelling elderly patients that peripheral neuropathy and foot deformity are independently associated with mobility impairment and potentially falls. Furthermore the findings suggest routine clinical diagnosis of foot complications as defined by national diabetic foot guidelines were sufficient to determine these associated foot complication risk factors for mobility impairment. Further research is required to establish if these foot complication risk factors for mobility impairment are predictors of actual falls in the inpatient environment.

A journey access tool to facilitate mobility-related access for people with disabilities in low and middle income countries

People with disabilities (PWD) experience difficulties in accessing the transport system (including both infrastructure and services) to meet their needs for health care, employment and other activities. Our research shows that lack of access to the journeys needed for these purposes is a more significant barrier in low and middle income countries than in high income countries, and results in inadequate health care, rehabilitation and access to education and employment. At the same time, the existing transport system in low and middle income countries presents much higher road crash risks than in high income countries. By combining the principles and methods of Road Safety Audit and disability access, and adapting these Western approaches to a low/middle income country context, we have worked with Handicap International Cambodia to develop a Journey Access Tool (JAT) for use by disabled peoples’ organisations (DPOs), people with a disability and other key stakeholders. A key element of the approach is that it involves the participation of PWD on the journeys that they need to take, and it identifies infrastructure and service improvements that should be prioritised in order to facilitate access to these journeys. The JAT has been piloted in Cambodia with a range of PWD. This presentation will outline the design of the JAT and the results of the pilot studies. The information gained thus far strongly suggests that the JAT is a valuable and cost-effective approach that can be used by DPOs and professionals to identify barriers to access and prioritise the steps needed to address them.

The last avant-garde?: Disability arts and (rethinking) mobility

Taking as its starting point a remark by Turner Prize nominee Yinka Shonibare that disability arts is “the last avant garde”, this panel focuses on the role of aesthetic experimentation in disability arts and the possible rethinking of the relationship between avant-garde aesthetic strategies and inclusive arts. Points of connection between the avant-garde and disability arts include a rejection of traditional aesthetic forms, the development of aesthetic strategies appropriate to non-normative bodies, politics and populations and the implications of these ideas for the conference themes. This panel is intended as a facilitated discussion involving researchers and artists undertaking work in this area. The panel will begin with some brief provocations reflecting on the implication of Shonibare’s comment. For example, Gerard Goggin will discuss three projects by Antoni Abad with artists and activists with disability in Barcelona, Geneva and Montreal as part of Abad’s Megaphone project, a decade-long, global digital art project. Bree Hadley will speak on performative interventions in public space, performance art, live art, activism and culture hacking by artists with disabilities, such as pwd's online performances, and artist’s performative responses to the austerity agenda in the US, UK, and Australasia. Eddie, Lachlan and Sarah will discuss ideas arising from their work on the project Beyond Access: The Creative Case for Inclusive Arts, which involved research with six Melbourne-based artists/artistic companies with disability, supported by Arts Access Victoria. Chair: Dr Eddie Paterson (School of Culture and Communication, Faculty of Arts, University of Melbourne) Dr Bree Hadley (Creative Industries, QUT) Professor Gerard Goggin (Professor of Media and Communication and ARC Future Fellow, University of Sydney) Dr Lachlan MacDowall (Head, Centre for Cultural Partnerships, University of Melbourne). Sarah Austin (PhD candidate, Theatre/Centre for Cultural Partnerships, VCA and MCM) Artists (tbc, based on existing relationships with artists developed in the Beyond Access research).

Avian diversification patterns across the K-Pg boundary: Influence of calibrations, datasets, and model misspecification

Birds represent the most diverse extant tetrapod clade, with ca. 10,000 extant species, and the timing of the crown avian radiation remains hotly debated. The fossil record supports a primarily Cenozoic radiation of crown birds, whereas molecular divergence dating analyses generally imply that this radiation was well underway during the Cretaceous. Furthermore, substantial differences have been noted between published divergence estimates. These have been variously attributed to clock model, calibration regime, and gene type. One underappreciated phenomenon is that disparity between fossil ages and molecular dates tends to be proportionally greater for shallower nodes in the avian Tree of Life. Here, we explore potential drivers of disparity in avian divergence dates through a set of analyses applying various calibration strategies and coding methods to a mitochondrial genome dataset and an 18-gene nuclear dataset, both sampled across 72 taxa. Our analyses support the occurrence of two deep divergences (i.e., the Palaeognathae/Neognathae split and the Galloanserae/Neoaves split) well within the Cretaceous, followed by a rapid radiation of Neoaves near the K-Pg boundary. However, 95% highest posterior density intervals for most basal divergences in Neoaves cross the boundary, and we emphasize that, barring unreasonably strict prior distributions, distinguishing between a rapid Early Paleocene radiation and a Late Cretaceous radiation may be beyond the resolving power of currently favored divergence dating methods. In contrast to recent observations for placental mammals, constraining all divergences within Neoaves to occur in the Cenozoic does not result in unreasonably high inferred substitution rates. Comparisons of nuclear DNA (nDNA) versus mitochondrial DNA (mtDNA) datasets and NT- versus RY-coded mitochondrial data reveal patterns of disparity that are consistent with substitution model misspecifications that result in tree compression/tree extension artifacts, which may explain some discordance between previous divergence estimates based on different sequence types. Comparisons of fully calibrated and nominally calibrated trees support a correlation between body mass and apparent dating error. Overall, our results are consistent with (but do not require) a Paleogene radiation for most major clades of crown birds.

Older male and female drivers in car-dependent settings: How much do they use other modes, and do they compensate for reduced driving to maintain mobility?

Among the societal and health challenges of population ageing is the continued transport mobility of older people who retain their driving licence, especially in highly car-dependent societies. While issues surrounding loss of a driving licence have been researched, less attention has been paid to variations in physical travel by mode among the growing proportion of older people who retain their driving licence. It is unclear how much they reduce their driving with age, the degree to which they replace driving with other modes of transport, and how this varies by age and gender. This paper reports research conducted in the state of Queensland, Australia, with a sample of 295 older drivers (>60 years). Time spent driving is considerably greater than time spent as a passenger or walking across age groups and genders. A decline in travel time as a driver with increasing age is not redressed by increases in travel as a passenger or pedestrian. The patterns differ by gender, most likely reflecting demographic and social factors. Given the expected considerable increase in the number of older women in particular, and their reported preference not to drive alone, there are implications for policies and programmes that are relevant to other car-dependent settings. There are also implications for the health of older drivers, since levels of walking are comparatively low.

If dung beetles (Scarabaeidae: Scarabaeinae) arose in association with dinosaurs, did they also suffer a mass co-extinction at the K-Pg boundary?

The evolutionary success of beetles and numerous other terrestrial insects is generally attributed to co-radiation with flowering plants but most studies have focused on herbivorous or pollinating insects. Non-herbivores represent a significant proportion of beetle diversity yet potential factors that influence their diversification have been largely unexamined. In the present study, we examine the factors driving diversification within the Scarabaeidae, a speciose beetle family with a range of both herbivorous and non-herbivorous ecologies. In particular, it has been long debated whether the key event in the evolution of dung beetles (Scarabaeidae: Scarabaeinae) was an adaptation to feeding on dinosaur or mammalian dung. Here we present molecular evidence to show that the origin of dung beetles occurred in the middle of the Cretaceous, likely in association with dinosaur dung, but more surprisingly the timing is consistent with the rise of the angiosperms. We hypothesize that the switch in dinosaur diet to incorporate more nutritious and less fibrous angiosperm foliage provided a palatable dung source that ultimately created a new niche for diversification. Given the well-accepted mass extinction of non-avian dinosaurs at the Cretaceous-Paleogene boundary, we examine a potential co-extinction of dung beetles due to the loss of an important evolutionary resource, i.e., dinosaur dung. The biogeography of dung beetles is also examined to explore the previously proposed "out of Africa" hypothesis. Given the inferred age of Scarabaeinae as originating in the Lower Cretaceous, the major radiation of dung feeders prior to the Cenomanian, and the early divergence of both African and Gondwanan lineages, we hypothesise that that faunal exchange between Africa and Gondwanaland occurred during the earliest evolution of the Scarabaeinae. Therefore we propose that both Gondwanan vicariance and dispersal of African lineages is responsible for present day distribution of scarabaeine dung beetles and provide examples.