Mitigating imported fuel dependency in agricultural production: Case study of an island nation's vulnerability to global catastrophic risks.

A major global catastrophe would likely disrupt trade in liquid fuels. Countries dependent on imported oil products might struggle to sustain industrial agriculture. Island nations importing 100% of refined fuels are particularly vulnerable. Our case study aimed to estimate the agricultural land area and biofuel volumes needed to feed the population of New Zealand in the absence of trade. Results showed that stored diesel would quickly be exhausted with ordinary use (weeks) and even with strict rationing (months). To preserve fuel, we found that farming wheat (requiring as little as 5.4 million liters [L] of diesel per annum) was more fuel-efficient than potatoes (12.3) or dairy (38.7) to feed the national population under a climate-as-usual scenario. In a nuclear winter scenario, with reduced agricultural yields, proportionately greater diesel is needed. The wheat would require 24% of current grain-cropped land, and the canola crop used as feedstock for the required biofuel would occupy a further 1%-7%. Investment in canola biodiesel or renewable diesel refineries could ensure supply for the bare minimum agricultural liquid fuel needs. Were subsequent analysis to favor this option as part of a fuels resilience response and as a tradeoff for routine food use, expansion in refining and canola cropping before a catastrophe could be encouraged through market mechanisms, direct government investment, or a combination of these. Logistics of biofuel refining scale-up, post-catastrophe, should also be analyzed. Further, biodiesel produced in normal times would help the nation meet its emissions reduction targets. Other countries should conduct similar analyses.

Mathematical optimization of frost resistant crop production to ensure food supply during a nuclear winter catastrophe.

This study aimed to estimate the optimal mix of frost resistant crops and land area needed to provide basic nutrition during various nuclear winter scenarios for New Zealand (NZ), a temperate island nation. It used linear programming to minimize land area required for cropping while producing enough food to achieve dietary energy and protein requirements for the whole population. The potential agricultural impacts of three nuclear winter scenarios on NZ, were sourced from the literature. The optimized combinations of frost resistant crops that were found to feed the entire population were, in descending order: wheat and carrots; sugar beet; oats; onions and carrots; cabbage and barley; canola and cabbage; linseed and parsnip; rye and lupins; swede and field beans; and cauliflower. But in terms of current production levels of these frost resistant crops in NZ, there would be a 26% shortfall for the "war without a nuclear winter" scenario and a 71% shortfall for the severe nuclear winter scenario (150 Tg of soot in the stratosphere with a 61% decline in crop yields). In conclusion, at current production levels, frost resistant food crops could not feed all NZ citizens following a nuclear war. There is a need for the NZ Government to conduct a detailed pre-war analysis on how these shortfalls are best addressed. For example, by: increased pre-war production of these crops and/or post-war scalability; growing enough frost sensitive crops (i.e., in greenhouses or the warmest parts of the country); and/or ensuring continuing production of food derived from livestock fed on frost resistant grasses.

A global assessment of the vulnerability of shellfish aquaculture to climate change and ocean acidification.

Human-induced climate change and ocean acidification (CC-OA) is changing the physical and biological processes occurring within the marine environment, with poorly understood implications for marine life. Within the aquaculture sector, molluskan culture is a relatively benign method of producing a high-quality, healthy, and sustainable protein source for the expanding human population. We modeled the vulnerability of global bivalve mariculture to impacts of CC-OA over the period 2020-2100, under RCP8.5. Vulnerability, assessed at the national level, was dependent on CC-OA-related exposure, taxon-specific sensitivity and adaptive capacity in the sector. Exposure risk increased over time from 2020 to 2100, with ten nations predicted to experience very high exposure to CC-OA in at least one decade during the period 2020-2100. Predicted high sensitivity in developing countries resulted, primarily, from the cultivation of species that have a narrow habitat tolerance, while in some European nations (France, Ireland, Italy, Portugal, and Spain) high sensitivity was attributable to the relatively high economic value of the shellfish production sector. Predicted adaptive capacity was low in developing countries primarily due to governance issues, while in some developed countries (Denmark, Germany, Iceland, Netherlands, Sweden, and the United Kingdom) it was linked to limited species diversity in the sector. Developing and least developed nations (n = 15) were predicted to have the highest overall vulnerability. Across all nations, 2060 was identified as a tipping point where predicted CC-OA will be associated with the greatest challenge to shellfish production. However, rapid declines in mollusk production are predicted to occur in the next decade for some nations, notably North Korea. Shellfish culture offers human society a low-impact source of sustainable protein. This research highlights, on a global scale, the likely extent and nature of the CC-OA-related threat to shellfish culture and this sector enabling early-stage adaption and mitigation.

Field trials of blood culture identification FilmArray in regional Australian hospitals.

Purpose. In this field trial of rapid blood culture identification (BCID), we aimed to determine whether the improved speed and accuracy of specific BCID predicted in our earlier pilot study could be obtained in regional hospitals by deploying a multiplex PCR FilmArray (Biomerieux, France) capability in their laboratories.Methods. We trained local hospital laboratory staff to operate the FilmArray equipment and act on the results. To do this, we integrated the multiplex PCR into the standard laboratory blood culture workflow and reporting procedure.Results. Of 100 positive blood culture episodes, BCID FilmArray results were correct in all 42 significant monobacterial cultures, with a fully predictive identity in 38 (90.5 %) and a partial identity in another four (9.5 %). There was one major error; a false positive Pseudomonas aeruginosa. The minor errors were the detection of one methicillin-resistant Staphylococcus aureus, which proved to be a methicillin-sensitive S. aureus mixed with a methicillin-resistant coagulase-negative staphylococcus, five false negative coagulase-negative staphylococci and one false negative streptococcus species. We found that 41/49 (84 %) clinically significant mono- and polymicrobial culture results were fully predictive of culture-based identification to bacterial species level at a mean of 1.15 days after specimen collection.Conclusions. There was a reduction of 1.21 days in the time taken to produce a definitive BCID compared to the previous year, translating into earlier communication of more specific blood culture results to the treating physician. Reduced time to definitive blood culture results has a direct benefit for isolated Australian communities at great distances from specialist hospital services.

Position-dependent diffusion of light in disordered waveguides.

We present direct experimental evidence for position-dependent diffusion in open random media. The interference of light in time-reversed paths results in renormalization of the diffusion coefficient, which varies spatially. To probe the wave transport inside the system, we fabricate two-dimensional disordered waveguides and monitor the light intensity from the third dimension. Change the geometry of the system or dissipation limits the size of the loop trajectories, allowing us to control the renormalization of the diffusion coefficient. This work shows the possibility of manipulating wave diffusion via the interplay of localization and dissipation.

Interplay between localization and absorption in disordered waveguides.

This work presents results of ab-initio simulations of continuous wave transport in disordered absorbing waveguides. Wave interference effects cause deviations from diffusive picture of wave transport and make the diffusion coefficient position- and absorption-dependent. As a consequence, the true limit of a zero diffusion coefficient is never reached in an absorbing random medium of infinite size, instead, the diffusion coefficient saturates at some finite constant value. Transition to this absorption-limited diffusion exhibits a universality which can be captured within the framework of the self-consistent theory (SCT) of localization. The results of this work (i) justify use of SCT in analyses of experiments in localized regime, provided that absorption is not weak; (ii) open the possibility of diffusive description of wave transport in the saturation regime even when localization effects are strong.