Food security, risk management and climate change

This report identifies major constraints to the adaptive capacity of food organisations operating in Australia. This report is about food security, climate change and risk management. Australia has enjoyed an unprecedented level of food security for more than half a century, but there are new uncertainties emerging and it would be unrealistic – if not complacent – to assume the same level of food security will persist simply because of recent history. The project collected data from more than 36 case study organisations (both foreign and local) operating in the Australian food-supply chain, and found that for many businesses,  risk management practices require substantial improvement to cope with and exploit the uncertainties that lie ahead. Three risks were identified as major constraints to adaptive capacity of food organisations operating in Australia:  risk management practices; an uncertain regulatory environment – itself a result of gaps in risk management; climate change uncertainty and projections about climate change impacts, also related to risk management

Super-R\'enyi Entropy & Wilson Loops for N=4 SYM and their Gravity Duals

We compute the supersymmetric R\'enyi entropies across a spherical entanglement surface in N=4 SU(N) SYM theory using localization on the four-dimensional ellipsoid. We extract the leading result at large N and \lambda, and match its universal part to a gravity calculation involving a hyperbolically sliced supersymmetric black hole solution of N=4+ SU(2) X U(1) gauged supergravity in five dimensions. We repeat the analysis in the presence of a Wilson loop insertion and find again a perfect match with the dual string theory. Understanding the Wilson loop operator requires knowledge of the full ten-dimensional IIB supergravity solution which we elaborate upon.Comment: 30+1 pages, 1 table; minor corrections, references added; matches published version (JHEP

Neural mechanisms of decision making in the pond snail Lymnaea stagnalis

The aim of this thesis was to identify key neural mechanisms underlying decision making in a model invertebrate system, the pond snail Lymnaea stagnalis. Specifically, this was examined with respect to two decision making processes associated with Lymnaea’s feeding behaviour; first a stimulus present/stimulus absent perceptual decision making task for selecting between appetitive and consummatory behaviours, second a behavioural choice between ingestion and egestion. A behavioural paradigm was designed in order to study stimulus present and stimulus absent decision making in Lymnaea. The switch between appetitive and consummatory behaviours was used as a read out of the decision. During stimulus absent decisions, the animal made a judgement about the absence of a sensory stimulus and entered into a period of quiescence. During stimulus present decisions the animal switched from the appetitive behaviour into the consummatory behaviour. The decision about the presence of a stimulus was reliant on the tactile cues from the potential food. Importantly the task was amenable for in vitro preparations and the identification of the decision neurons. A candidate stimulus present decision neuron, the ventral trigger neuron (vTN), was identified in the buccal ganglia. vTN received appropriate sensory input and was able to initiate fictive feeding cycles. vTN was able to initiate fictive feeding cycles via monosynaptic connections with feeding central pattern generator (CPG) interneurons. Development of an in vitro paradigm of the stimulus present and stimulus absent decision provided strong evidence that vTN was a stimulus present decision neuron. A stimulus absent decision neuron was identified as the inhibitory interneuron and member of the feeding CPG, N3t. An in vitro paradigm was used to test interactions of the stimulus present decision neuron with the stimulus absent decision neuron. Goal directed behaviours were also shown to lower the threshold of activity needed for vTN to initiate fictive consummatory behaviours, lowering the sensory threshold needed for stimulus present decisions to be made. The neural mechanism of behavioural choice between ingestion and egestion in Lymnaea was characterised using in vivo and in vitro preparations. A novel motor neuron was identified whose phase of firing activity was selectively shifted between the two behaviours. The interneuronal control of ingestion was identified and consisted of previously identified command-like neurons, whereas the interneuronal control of egestion consisted of novel interneurons located in the buccal ganglia. The two networks showed evidence of both dedicated and multifunctional interneurons. The studies presented in this thesis demonstrate that even within the same relatively simple neural network several distinct mechanisms are utilised for different types of decision. These were identified at the level of individual neurons and their synaptic connectivity. Uniquely in these studies, distinct stimulus absent and stimulus present decision neurons were identified in the perceptual decision task and it was also shown that performing the decision making task facilitates the stimulus present decision. This provides fundamental new insights into the neural mechanisms of decision making. The studies also provide a model system for comparison between a form of decision making studied extensively in mammals (perceptual decision making in a stimulus absent/stimulus present task) and a form studied primarily in invertebrates (behavioural choice between two incompatible behaviours), bridging the gap between invertebrate and vertebrate decision making studies

Off-shell hydrodynamics from holography

We outline a program for obtaining an action principle for dissipative fluid dynamics by considering the holographic Wilsonian renormalization group applied to systems with a gravity dual. As a first step, in this paper we restrict to systems with a non-dissipative horizon. By integrating out gapped degrees of freedom in the bulk gravitational system between an asymptotic boundary and a horizon, we are led to a formulation of hydrodynamics where the dynamical variables are not standard velocity and temperature fields, but the relative embedding of the boundary and horizon hypersurfaces. At zeroth order, this action reduces to that proposed by Dubovsky et al. as an off-shell formulation of ideal fluid dynamics.Comment: 34 pages, 2 figures; v2: references added, clarifications added in Sec. I

Leptinotarsa decemlineata (Coleoptera: Chrysomelidae) Observed Feeding on Chamaesaracha sp. in Eastern Colorado.

Egg, larval, and adult life stages of Colorado potato beetle, Leptinotarsa decemlineata (Say), were observed feeding on or attached to a previously undocumented host plant belonging to the genus Chamaesaracha in eastern Colorado on July 2017. At one site, L. decemlineata were more abundant on Chamaesaracha sp. than the accepted ancestral host plant, Solanum rostratum (Dunal). While future studies should confirm the ancestral status of the observed L. decemlineata and suitability of Chamaesaracha sp. for completion of development, our observations suggest a need for further characterization of the ancestral host range of L. decemlineata

National Catastrophic Drug Insurance Revisited: Who Would Benefit from Senator Kirby's Recommendations?

The recent "Romanow" and "Kirby" inquiries into the Canadian health care system recommended a publicly funded catastrophic prescription drug insurance program to protect Canadians from potentially ruinous drug costs. While the Romanow commission was not specific about the nature of such a program, the Kirby commission recommended that household prescription drug expenses be capped at 3% of total household income, or $1,500 per household member, whichever is lower, with government picking up the remainder. Using recent survey data on household spending, we estimate how the program would assist households of different means and ages, residing in different regions of the country. We find that, despite the fact that senior and low income non-senior households are the primary beneficiaries of provincial government drug plans, average subsidies would be over 4 times higher for these households than for all other (non-senior, non-indigent) households. A small percentage of other households would be among the largest beneficiaries of the program. Program benefits are typically larger in provinces with less generous public coverage and tend to benefit lower income households. Program costs are estimated to be at least$461 million annually, although reductions in out of pocket drug spending will reduce medical tax credits and thereby increase tax revenues by at least $80 million. Program costs appeared to be very sensitive to increased household drug spending that might result from the program introduction.drug insurance; prescription drug expenses

National Catastrophic Drug Insurance Revisited: Who Would Benefit from Senator Kirby's Recommendations?

The recent "Romanow" and "Kirby" inquiries into the Canadian health care system recommended a publicly funded catastrophic prescription drug insurance program to protect Canadians from potentially ruinous drug costs. While the Romanow commission was not specific about the nature of such a program, the Kirby commission recommended that household prescription drug expenses be capped at 3% of total household income, or $1,500 per household member, whichever is lower, with government picking up the remainder. Using recent survey data on household spending, we estimate how the program would assist households of different means and ages, residing in different regions of the country. We find that, despite the fact that senior and low income non-senior households are the primary beneficiaries of provincial government drug plans, average subsidies would be over 4 times higher for these households than for all other (non-senior, non-indigent) households. A small percentage of other households would be among the largest beneficiaries of the program. Program benefits are typically larger in provinces with less generous public coverage and tend to benefit lower income households. Program costs are estimated to be at least$461 million annually, although reductions in out of pocket drug spending will reduce medical tax credits and thereby increase tax revenues by at least $80 million. Program costs appeared to be very sensitive to increased household drug spending that might result from the program introduction.drug insurance; prescription drug expenses